GBSS14.0 Optional Feature Description

GBSS14.0 Optional Feature Description

Issue

V0.5

Date

2011-08-30

HUAWEI TECHNOLOGIES CO., LTD.

Copyright © Huawei Technologies Co., Ltd. 2011. All rights reserved. No part of this document may be reproduced or transmitted in any form or by any means without prior written consent of Huawei Technologies Co., Ltd.

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Notice The purchased products, services and features are stipulated by the commercial contract made between Huawei and the customer. All or partial products, services and features described in this document may not be within the purchased scope or the usage scope. Unless otherwise agreed by the contract, all statements, information, and recommendations in this document are provided "AS IS" without warranties, guarantees or representations of any kind, either express or implied. The information in this document is subject to change without notice. Every effort has been made in the preparation of this document to ensure accuracy of the contents, but all statements, information, and recommendations in this document do not constitute a warranty of any kind, express or implied.

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Issue V0.5 (2011-08-30)

Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd

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Contents

Contents 1 Voice&Service................................................................................................................................ 1 1.1 Crystal Voice .................................................................................................................................................... 1 1.1.1 GBFD-113301 Enhanced Full Rate ........................................................................................................ 1 1.1.2 GBFD-115601 Automatic Level Control (ALC) .................................................................................... 2 1.1.3 GBFD-115602 Acoustic Echo Cancellation (AEC) ................................................................................ 5 1.1.4 GBFD-115603 Automatic Noise Restraint (ANR) .................................................................................. 6 1.1.5 GBFD-115701 TFO ................................................................................................................................ 7 1.1.6 GBFD-115702 TrFO ............................................................................................................................... 9 1.1.7 GBFD-115703 Automatic Noise Compensation (ANC) ....................................................................... 11 1.1.8 GBFD-115704 Enhancement Packet Loss Concealment (EPLC) ......................................................... 12 1.1.9 GBFD-115711 EVAD ........................................................................................................................... 14 1.1.10 GBFD-116801 Voice Quality Index (VQI) ......................................................................................... 15 1.1.11 GBFD-115708 Um Interface Speech Frame Repairing ....................................................................... 16 1.2 AMR Package................................................................................................................................................. 17 1.2.1 GBFD-115501 AMR FR ....................................................................................................................... 17 1.2.2 GBFD-115502 AMR HR ...................................................................................................................... 19 1.2.3 GBFD-115503 AMR Power Control ..................................................................................................... 21 1.2.4 GBFD-115504 AMR FR/HR Dynamic Adjustment .............................................................................. 22 1.2.5 GBFD-115505 AMR Radio Link Timer ............................................................................................... 23 1.2.6 GBFD-115506 AMR Coding Rate Threshold Adaptive Adjustment .................................................... 24 1.2.7 GBFD-115507 WB AMR...................................................................................................................... 26 1.3 Voice Capacity................................................................................................................................................ 27 1.3.1 GBFD-113401 Half Rate Speech .......................................................................................................... 27 1.3.2 GBFD-113402 Dynamic Adjustment Between FR and HR .................................................................. 28 1.3.3 GBFD-115522 Dynamic HR/FR Adaptation ........................................................................................ 30 1.3.4 GBFD-115830 VAMOS ........................................................................................................................ 31 1.3.5 GBFD-115831 Mute SAIC MS Identification ...................................................................................... 33 1.3.6 GBFD-115832 VAMOS Call Drop Solution ......................................................................................... 34 1.4 Cell Broadcast ................................................................................................................................................ 35 1.4.1 GBFD-113601 Short Message Service Cell Broadcast (TS23) ............................................................. 35 1.4.2 GBFD-113602 Simplified Cell Broadcast ............................................................................................ 36 1.5 GSM Trunking ............................................................................................................................................... 38 1.5.1 GBFD-510301 Public Voice Group Call Service .................................................................................. 38

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1.5.2 GBFD-510303 Late Group Channel Assignment ................................................................................. 39 1.5.3 GBFD-510305 Single Channel Group Call Originating ....................................................................... 40 1.5.4 GBFD-510306 Talker Identification ..................................................................................................... 41 1.5.5 GBFD-510307 Group Call EMLPP ...................................................................................................... 42 1.5.6 GBFD-510308 Fast Group Call Setup .................................................................................................. 43 1.5.7 GBFD-510309 Group Call Reliability Enhancing ................................................................................ 44 1.5.8 GBFD-510302 Public Voice Broadcast Service .................................................................................... 46 1.5.9 GBFD-510304 Late Broadcast Channel Assignment ............................................................................ 47 1.5.10 GBFD-510310 GSM-T Relay ............................................................................................................. 48 1.6 LCS ................................................................................................................................................................ 49 1.6.1 GBFD-115401 NSS-based LCS (Cell ID + TA) ................................................................................... 49 1.6.2 GBFD-115402 BSS-based LCS (Cell ID + TA) ................................................................................... 50 1.6.3 GBFD-115403 Simple Mode LCS (Cell ID + TA) ............................................................................... 51 1.6.4 GBFD-115404 Lb Interface .................................................................................................................. 52 1.7 VIP Service..................................................................................................................................................... 54 1.7.1 GBFD-116001 Resource Reservation ................................................................................................... 54 1.7.2 GBFD-115001 Enhanced Multi Level Precedence and Preemption (EMLPP) ..................................... 55 1.7.3 GBFD-115002 Flow Control Based on Cell Priority ............................................................................ 57 1.7.4 GBFD-115003 Flow control based on User priority ............................................................................. 58 1.7.5 GBFD-119907 PS Service in Priority ................................................................................................... 59

2 Packet Service .............................................................................................................................. 61 2.1 PS Prime Service ............................................................................................................................................ 61 2.1.1 GBFD-114101 GPRS ............................................................................................................................ 61 2.1.2 GBFD-510001 Network Operation Mode I .......................................................................................... 62 2.1.3 GBFD-118901 CS-3/CS-4 .................................................................................................................... 64 2.1.4 GBFD-114201 EGPRS ......................................................................................................................... 65 2.1.5 GBFD-113101 PDCH Dynamic Adjustment ........................................................................................ 67 2.1.6 GBFD-510002 Gb Over FR .................................................................................................................. 69 2.1.7 GBFD-119201 11-Bit EGPRS Access .................................................................................................. 70 2.1.8 GBFD-119203 Extended Uplink TBF .................................................................................................. 71 2.1.9 GBFD-119204 Dynamically Adjusting the Uplink MCS Coding ......................................................... 72 2.1.10 GBFD-119205 Dynamically Adjusting the RRBP Frequency ............................................................ 73 2.1.11 GBFD-119302 Packet Channel Dispatching ....................................................................................... 74 2.1.12 GBFD-119303 Load Sharing .............................................................................................................. 76 2.1.13 GBFD-119501 Adaptive Adjustment of Uplink and Downlink Channels .......................................... 77 2.2 PS Service Enhancement ................................................................................................................................ 79 2.2.1 GBFD-119901 Streaming QoS(GBR) ................................................................................................... 79 2.2.2 GBFD-119902 QoS ARP&THP............................................................................................................ 80 2.2.3 GBFD-119904 PS Active Package Management .................................................................................. 81 2.2.4 GBFD-119905 PoC QoS ....................................................................................................................... 83 2.2.5 GBFD-119906 Conversational QoS ...................................................................................................... 84

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2.2.6 GBFD-116201 Network-Controlled Cell Reselection (NC2) ............................................................... 86 2.2.7 GBFD-116301 Network Assisted Cell Change (NACC) ...................................................................... 87 2.2.8 GBFD-119801 Packet SI Status (PSI) ................................................................................................... 88 2.2.9 GBFD-119305 BSS Paging Coordination ............................................................................................. 89 2.2.10 GBFD-119502 PS Handover ............................................................................................................... 90 2.2.11 GBFD-119503 Early TBF Establishment ............................................................................................ 91 2.2.12 GBFD-119504 PS Power Control ....................................................................................................... 92 2.2.13 GBFD-119505 PDCH Dynamic Adjustment with Two Thresholds .................................................... 94 2.2.14 GBFD-119506 GPRS/EGPRS Time slot multiplexing priority .......................................................... 95 2.2.15 GBFD-119401 Extended Dynamic Allocation (EDA) ........................................................................ 96 2.2.16 GBFD-119402 MS High Multislot Classes ......................................................................................... 97 2.2.17 GBFD-114151 DTM ........................................................................................................................... 98 2.2.18 GBFD-119403 Class11 DTM ........................................................................................................... 100 2.2.19 GBFD-119404 HMC DTM ............................................................................................................... 102 2.2.20 GBFD-119405 14.4kbit/s Circuit Switched Data .............................................................................. 103 2.2.21 GBFD-119406 High Speed Circuit Switched Data ........................................................................... 104 2.2.22 GBFD-119407 Active TBF Allocation .............................................................................................. 106 2.3 EDGE Evolution .......................................................................................................................................... 108 2.3.1 GBFD-510801 MSRD ........................................................................................................................ 108 2.3.2 GBFD-510802 Dual Carriers in Downlink ......................................................................................... 109 2.3.3 GBFD-510803 Uplink EGPRS2-A ..................................................................................................... 110 2.3.4 GBFD-510804 Downlink EGPRS2-A ................................................................................................ 112 2.3.5 GBFD-510805 Latency Reduction ..................................................................................................... 114

3 Smart MBB ................................................................................................................................. 117 3.1 Intelligent Channel ....................................................................................................................................... 117 3.1.1 GBFD-511603 IM Service Efficiency Improvement .......................................................................... 117 3.1.2 GBFD-511604 Web Browsing Service Efficiency Improvement ....................................................... 118 3.1.3 GBFD-511605 Email Service Efficiency Improvement ..................................................................... 120 3.1.4 GBFD-511606 Streaming Media Service Resource Balancing........................................................... 121 3.1.5 GBFD-511607 P2P Resource Balancing ............................................................................................. 122 3.2 Smartphone Solution .................................................................................................................................... 124 3.2.1 GBFD-511501 Multiple CCCHs ......................................................................................................... 124 3.2.2 GBFD-511502 Layered Paging ........................................................................................................... 125 3.2.3 GBFD-511503 Dynamic Multiple CCCH ........................................................................................... 126

4 Green ........................................................................................................................................... 128 4.1 Power Consumption Saving ......................................................................................................................... 128 4.1.1 GBFD-117601 HUAWEI III Power Control Algorithm ..................................................................... 128 4.1.2 GBFD-117602 Active Power Control ................................................................................................. 129 4.1.3 GBFD-118103 Network Support SAIC .............................................................................................. 131 4.1.4 GBFD-114801 Discontinuous Transmission (DTX)-Downlink .......................................................... 132 4.1.5 GBFD-114803 Discontinuous Transmission (DTX)-Uplink .............................................................. 133

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4.1.6 GBFD-111602 TRX Power Amplifier Intelligent Shutdown .............................................................. 135 4.1.7 GBFD-111603 TRX Power Amplifier Intelligent Shutdown on Timeslot Level ................................ 136 4.1.8 GBFD-111604 Intelligent Combiner Bypass ...................................................................................... 137 4.1.9 GBFD-111605 Active Backup Power Control .................................................................................... 138 4.1.10 GBFD-111606 Power Optimization Based on Channel Type ........................................................... 140 4.1.11 GBFD-111608 PSU Smart Control ................................................................................................... 141 4.1.12 GBFD-111609 Enhanced BCCH Power Consumption Optimization ............................................... 142 4.1.13 GBFD-111610 Dynamic Cell Power Off .......................................................................................... 143 4.1.14 GBFD-111611 TRX Working Voltage Adjustment ........................................................................... 145 4.1.15 GBFD-111612 Multi-Carrier Intelligent Voltage Regulation ............................................................ 146

5 Topology&Transmission ......................................................................................................... 148 5.1 Transmission Efficiency ............................................................................................................................... 148 5.1.1 GBFD-116701 16Kbit RSL and OML on Abis Interface .................................................................... 148 5.1.2 GBFD-117301 Flex Abis .................................................................................................................... 149 5.1.3 GBFD-117702 BTS Local Switch ...................................................................................................... 150 5.1.4 GBFD-118401 Abis Transmission Optimization ................................................................................ 153 5.1.5 GBFD-112013 Abis Congestion Trigger HR Distribution .................................................................. 155 5.1.6 GBFD-116901 Flex Ater ..................................................................................................................... 157 5.1.7 GBFD-117701 BSC Local Switch ...................................................................................................... 158 5.1.8 GBFD-116902 Ater Compression Transmission ................................................................................. 161 5.1.9 GBFD-511201 2G/3G Co-Transmission by TDM Switching ............................................................. 163 5.1.10 GBFD-115301 Local Multiple Signaling Points ............................................................................... 165 5.2 IP Transmission ............................................................................................................................................ 166 5.2.1 GBFD-118606 Clock Over IP ............................................................................................................. 166 5.2.2 GBFD-118620 Clock over IP support 1588v2 .................................................................................... 168 5.2.3 GBFD-118202 Synchronous Ethernet................................................................................................. 170 5.2.4 GBFD-118601 Abis over IP ................................................................................................................ 171 5.2.5 GBFD-118611 Abis IP over E1/T1 ..................................................................................................... 175 5.2.6 GBFD-118604 Abis MUX .................................................................................................................. 177 5.2.7 GBFD-118612 Abis IPHC .................................................................................................................. 178 5.2.8 GBFD-118602 A over IP ..................................................................................................................... 180 5.2.9 GBFD-118622 A IP over E1/T1 .......................................................................................................... 183 5.2.10 GBFD-118610 UDP MUX for A Transmission ................................................................................ 185 5.2.11 GBFD-118623 TDM/IP Dual Transmission over A Interface ........................................................... 186 5.2.12 GBFD-118603 Gb over IP ................................................................................................................ 188 5.2.13 GBFD-118605 IP QoS ...................................................................................................................... 190 5.2.14 GBFD-118630 Ethernet OAM .......................................................................................................... 193 5.3 Satellite Transmission .................................................................................................................................. 195 5.3.1 GBFD-113901 Satellite Transmission over Abis Interface ................................................................. 195 5.3.2 GBFD-113902 Satellite Transmission over A Interface ...................................................................... 196 5.3.3 GBFD-113903 Satellite Transmission over Ater Interface .................................................................. 197

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5.3.4 GBFD-113905 Satellite Transmission over Gb Interface.................................................................... 198 5.4 RAN Sharing ................................................................................................................................................ 199 5.4.1 GBFD-118701 RAN Sharing .............................................................................................................. 199 5.4.2 GBFD-118704 Abis Independent Transmission .................................................................................. 200 5.4.3 GBFD-118702 MOCN Shared Cell .................................................................................................... 202 5.4.4 GBFD-118703 IMSI-Based Handover ................................................................................................ 203

6 Site Solution ............................................................................................................................... 205 6.1 PICO Solution .............................................................................................................................................. 205 6.1.1 GBFD-510601 PICO Automatic Configuration and Planning ............................................................ 205 6.1.2 GBFD-510602 PICO Synchronization................................................................................................ 206 6.1.3 GBFD-510603 PICO Dual-band Auto-planning ................................................................................. 207 6.1.4 GBFD-510604 PICO USB Encryption ............................................................................................... 209 6.1.5 GBFD-510605 PICO Access Control List (ACL) ............................................................................... 210 6.1.6 GBFD-510606 PICO Sleeping Mode ................................................................................................. 210 6.1.7 GBFD-510607 PICO Automatic Optimization ................................................................................... 211 6.1.8 GBFD-510608 PICO Transceiver Redundancy .................................................................................. 212 6.2 EasyGSM Solution ....................................................................................................................................... 213 6.2.1 GBFD-510701 Compact BTS Automatic Configuration and Planning .............................................. 213 6.2.2 GBFD-510702 Compact BTS Automatic Capacity Planning ............................................................. 215 6.2.3 GBFD-510704 Compact BTS Automatic Neighbor Cell Planning and Optimization ........................ 216 6.2.4 GBFD-510705 Compact BTS Timing Power Off ............................................................................... 217 6.2.5 GBFD-510706 Local User Management ............................................................................................ 218 6.2.6 GBFD-111613 Weather Adaptive Power Management ....................................................................... 220 6.3 Auxiliary Equipment Management .............................................................................................................. 222 6.3.1 GBFD-510710 Intelligent Battery Management ................................................................................. 222

7 Network Performance .............................................................................................................. 224 7.1 Coverage Enhancement ................................................................................................................................ 224 7.1.1 GBFD-115901 PBT(Power Boost Technology) .................................................................................. 224 7.1.2 GBFD-115902 Transmit Diversity ...................................................................................................... 225 7.1.3 GBFD-115903 4-Way Receiver Diversity .......................................................................................... 226 7.1.4 GBFD-118101 Dynamic Transmit Diversity ...................................................................................... 227 7.1.5 GBFD-118102 Dynamic PBT (Power Boost Technology) ................................................................. 228 7.1.6 GBFD-118104 Enhanced EDGE Coverage ........................................................................................ 230 7.1.7 GBFD-118106 Dynamic Power Sharing ............................................................................................. 231 7.1.8 GBFD-114001 Extended Cell ............................................................................................................. 233 7.2 Capacity Improvement ................................................................................................................................. 235 7.2.1 GBFD-113201 Concentric Cell ........................................................................................................... 235 7.2.2 GBFD-114501 Co-BCCH Cell ........................................................................................................... 236 7.2.3 GBFD-114402 Enhanced Dual-band Network ................................................................................... 238 7.2.4 GBFD-117001 Flex MAIO ................................................................................................................. 239 7.2.5 GBFD-115801 ICC ............................................................................................................................. 240

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7.2.6 GBFD-115821 EICC ........................................................................................................................... 241 7.2.7 GBFD-113701 Frequency Hopping (RF hopping, baseband hopping) ............................................... 243 7.2.8 GBFD-113702 BCCH Carrier Frequency Hopping ............................................................................ 244 7.2.9 GBFD-113703 Antenna Frequency Hopping ...................................................................................... 245 7.2.10 GBFD-118001 BCCH Dense Frequency Multiplexing..................................................................... 247 7.2.11 GBFD-117002 IBCA (Interference Based Channel Allocation) ....................................................... 248 7.2.12 GBFD-118201 Soft-Synchronized Network ..................................................................................... 250 7.2.13 GBFD-510401 BTS GPS Synchronization ....................................................................................... 252 7.2.14 GBFD-113706 Mega BSC ................................................................................................................ 254 7.3 High Speed Mobility .................................................................................................................................... 255 7.3.1 GBFD-510101 Automatic Frequency Correction (AFC) .................................................................... 255 7.3.2 GBFD-510102 Fast Move Handover .................................................................................................. 257 7.3.3 GBFD-510103 Chain Cell Handover .................................................................................................. 258 7.3.4 GBFD-510104 Multi-site Cell ............................................................................................................ 259 7.3.5 GBFD-510105 PS AFC ....................................................................................................................... 260 7.4 Intra-System Mobility Management ............................................................................................................ 262 7.4.1 GBFD-510501 HUAWEI II Handover ............................................................................................... 262 7.4.2 GBFD-510502 Handover Re-establishment ....................................................................................... 263 7.4.3 GBFD-117501 Enhanced Measurement Report (EMR) ..................................................................... 264 7.4.4 GBFD-117101 BTS Power Lift for Handover .................................................................................... 266 7.5 GSM & WCDMA Interoperability ............................................................................................................... 267 7.5.1 GBFD-114301 GSM/WCDMA Interoperability ................................................................................. 267 7.5.2 GBFD-114321 GSM/WCDMA Service Based Handover .................................................................. 268 7.5.3 GBFD-114322 GSM/WCDMA Load Based Handover ...................................................................... 269 7.5.4 GBFD-114323 GSM/WCDMA Cell Reselection Based on MS State ................................................ 270 7.5.5 GBFD-114325 Fast WCDMA Reselection at 2G CS Call Release ..................................................... 272 7.5.6 GBFD-511101 Load Based Handover Enhancement on Iur-g ............................................................ 273 7.5.7 GBFD-511102 NACC Procedure Optimization Based on Iur-g between GSM and WCDMA .......... 274 7.5.8 GBFD-511103 GSM and WCDMA Load Balancing Based on Iur-g ................................................. 276 7.5.9 GBFD-511104 GSM and WCDMA Traffic Steering Based on Iur-g .................................................. 278 7.6 GSM & LTE Interoperability ....................................................................................................................... 279 7.6.1 GBFD-511301 Cell Reselection Between GSM and LTE .................................................................. 279 7.6.2 GBFD-511302 PS Handover Between GSM and LTE Based on Coverage ........................................ 281 7.6.3 GBFD-511303 PS Handover Between GSM and LTE Based on Quality ........................................... 282 7.6.4 GBFD-511304 PS Handover Between GSM and LTE Based on Cell Load ....................................... 284 7.6.5 GBFD-511305 PS Handover Between GSM and LTE Based on Mode Priority................................. 285 7.6.6 GBFD-511306 GSM/LTE Service Based PS Handover ..................................................................... 287 7.6.7 GBFD-511307 eNC2 Between GSM and LTE ................................................................................... 289 7.6.8 GBFD-511308 eNACC Between GSM and LTE ................................................................................ 290 7.6.9 GBFD-511309 SRVCC ....................................................................................................................... 291 7.6.10 GBFD-511310 Multi Technology Neighbour Cell Based Handover ................................................ 293 7.6.11 GBFD-511312 Fast LTE Reselection at 2G CS Call Release ........................................................... 294

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7.6.12 GBFD-511313 CSFB ........................................................................................................................ 295 7.7 GSM & TD-SCDMA Interoperability .......................................................................................................... 296 7.7.1 GBFD-114302 GSM/TD-SCDMA Interoperability ............................................................................ 296 7.7.2 GBFD-511401 Iur-g Interface Between GSM and TD-SCDMA ........................................................ 297 7.7.3 GBFD-511402 Radio Resource Reserved Handover Between GSM/TD-SCDMA Based on Iur-g ... 299 7.7.4 GBFD-511403 Extended BCCH ......................................................................................................... 301 7.7.5 GBFD-511405 NC2 between GSM and TD-SCDMA ........................................................................ 302

8 Network Security ...................................................................................................................... 304 8.1 Security ........................................................................................................................................................ 304 8.1.1 GBFD-113501 A5/1 and A5/2 Ciphering Algorithm .......................................................................... 304 8.1.2 GBFD-113503 A5/3 Ciphering Algorithm .......................................................................................... 305 8.1.3 GBFD-113521 A5/1 Encryption Flow Optimization .......................................................................... 306 8.1.4 GBFD-113522 Encrypted Network Management ............................................................................... 307 8.1.5 GBFD-113524 BTS Integrated IPsec .................................................................................................. 309 8.1.6 GBFD-113526 BTS Supporting PKI .................................................................................................. 310 8.2 Reliability ..................................................................................................................................................... 312 8.2.1 GBFD-117801 Ring Topology ............................................................................................................ 312 8.2.2 GBFD-113801 TRX Cooperation ....................................................................................................... 315 8.2.3 GBFD-117401 MSC Pool ................................................................................................................... 316 8.2.4 GBFD-119701 SGSN Pool ................................................................................................................. 318 8.2.5 GBFD-116601 Abis Bypass ................................................................................................................ 320 8.2.6 GBFD-113721 Robust Air Interface Signalling .................................................................................. 321 8.2.7 GBFD-117803 Abis Transmission Backup ......................................................................................... 323 8.2.8 GBFD-113725 BSC Node Redundancy .............................................................................................. 324 8.2.9 GBFD-113726 TC POOL ................................................................................................................... 326 8.2.10 GBFD-113728 OML Backup ............................................................................................................ 327 8.2.11 GBFD-511002 Access Control Class (ACC) .................................................................................... 329

9 O&M Experience ....................................................................................................................... 331 9.1 O&M ............................................................................................................................................................ 331 9.1.1 GBFD-113729 Adaptive Transmission Link Blocking ....................................................................... 331 9.1.2 GBFD-114701 Semi-Permanent Connection ...................................................................................... 332 9.1.3 GBFD-116401 End-to-End MS Signaling Tracing ............................................................................. 335 9.1.4 GBFD-510901 GSM/3G Neighboring Cell Automatic Optimization ................................................. 336 9.2 Visualization & Data Collection ................................................................................................................... 338 9.2.1 GBFD-511701 Radio Measurement Data Interface for Navigation .................................................... 338

A Acronyms and Abbreviations ................................................................................................ 340

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1.1 Crystal Voice 1.1.1 GBFD-113301 Enhanced Full Rate Availability This feature was introduced in GBSS6.1.

Summary The enhanced full rate (EFR) is an improved speech coding scheme. The quality of the speech using EFR is better than that of the speech using FR.

Benefits The user experience is improved because the voice quality in the EFR that uses the FR channel resource approaches or even exceeds the voice quality in the ADPCM.

Description The EFR is an improved speech coding scheme, which works at the rate of 12.2 kbit/s. The quality of the voice using the FR channel resource in the EFR scheme approaches or even exceeds the voice quality in the ADPCM scheme. The EFR has good anti-noise performance. If the quality of the Um interface is good, you can obtain the voice quality as good as the voice quality of the traditional wired telephone even if there is a lot of background noise. Therefore, in the same air conditions, the subscriber can perceive a better voice quality in the EFR than in the FR. In addition, the rate of the EFR is lower than that of the FR (13 kbit/s). Therefore, the BER sensitivity of EFR is lower than that of FR. In this manner, the data can be transmitted more reliably on the Abis interface, which further improves the voice quality. The EFR is also compatible with the highest rate of the narrowband AMR.

Enhancement GBSS8.1

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The EFR is introduced in GBSS8.1 and it is used in A over TDM transmission. If the EFR feature is supported by the MS and the BSC but not supported by the MSC, the EFR feature can be forcibly enabled on the BSC. In this manner, the used speech version is shielded on the MSC side to avoid assignment or handover failure. The forced EFR function is mainly applied in the areas with poor voice quality to improve the voice quality. GBSS13.0 E-coder is introduced in GBSS13.0 and it is used in A over TDM transmission. E-coder improves the EFR speech quality by using the enhanced spectrum technique and LSP exact-calculate technique. In this way, E-coder increases the Mean Opinion Score (MOS) by 0.05 to 0.12. E-coder, however, introduces an algorithm delay of 5 ms to an EFR encoder. In A over IP or TFO, E-coder is not supported.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The MS must support this feature.

1.1.2 GBFD-115601 Automatic Level Control (ALC) Availability This feature was introduced in GBSS6.1.

Summary This feature improves the user experience by checking the speech signals and then adjusting the sound volume according to certain rules to keep the sound volume within the comfort range.

Benefits This feature can level out the difference between the sound volumes controlled by different terminal manufacturers and therefore balance the receive level adaptation of subscribers in different areas. In this manner, the subscriber can perceive better voice quality.

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Description The ALC algorithm automatically controls the receive level. By evaluating the receive level of the input signal, the ALC feature controls the gains of the input signal, adjusts the output signal to a certain target receive level, and maintains the stability and comprehensibility of the signal receive level. Therefore, the subscriber can perceive comfort sound volume and good voice quality. The ALC has the following three modes: 

Fixed level mode The receive level of the signal is adjusted to a fixed target value based on the receive level of the input voice.



Adaptive level mode The receive level of the signal is adaptively adjusted to a value within a pre-determined range based on the receive level of the input voice.



Fixed gain mode The sound volume of the input signal is raised or lowered in a fixed proportion based on the original sound volume.

Enhancement GBSS8.1 The ALC algorithm performance is optimized. GBSS12.0 The anti-clip (ACLP) algorithm is introduced in GBSS12.0. The ACLP algorithm first corrects the signals with relatively great amplitude, quickly repairs the speech wave, and then adjusts the volume. This improves the user experience. The ACLP algorithm calculates the energy and spectrum characteristics of input speech signals in real time. If too-high-level signals suffer from amplitude limiting and therefore introduce distorted noises, the ACLP algorithm filters out distorted noises and performs nonlinear volume adjustments to repair the signal wave according to spectrum characteristics. In this manner, the user experience towards the voice quality is improved.

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The volume is acceptable but the distortion remains. The volume is too great and signals are distorted due to amplitude limiting.

Repair the distorted signals.

The volume is acceptable and the distortion is decreased.

The function of measuring and collecting statistics on signal levels online is introduced. In GBSS12.0, the ALC algorithm can be used to measure and collect statistics on signal levels online so that operators can monitor signal levels and learn the distribution of signal levels to determine whether to enable the ALC algorithm for cells. GBSS14.0 The level adjustment performance is optimized. 1.

The speech tracing and adaptive capability of the ALC algorithm is optimized so that the ALC algorithm becomes more responsive to situations where the volume changes rapidly.

2.

The internal dependencies on a fixed clipping threshold of the ACLP algorithm are canceled so that the clipping threshold is adaptive to signal level changes.

3.

A counter is provided to measure the signal level and the number of clipping occurrences.

Dependency Dependency on BSC hardware None

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Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-118602 A over IP GBFD-118622 A IP over E1/T1 GBFD-115701 TFO GBFD-115702 TrFO GBFD-117701 BSC Local Switch GBFD-117702 BTS Local Switch Dependency on other NEs None

1.1.3 GBFD-115602 Acoustic Echo Cancellation (AEC) Availability This feature was introduced in GBSS6.1.

Summary The AEC identifies and cancels the acoustic echo after comparing the main features of downlink voice and those of uplink voice after a period of delay.

Benefits The AEC can reduce the acoustic echo generated by the MS, improving the network voice quality and the user experience.

Description The acoustic echo refers to the situation that the sound wave from one MS speaker is reflected to the microphone (MIC) and the speech signal is sent back to the other MS because of the characteristics of the MS. The acoustic echo generated by the MS is mainly related to the fact that the MS speaker is too close to the MIC and therefore the sound wave attenuation is insufficient. During the call, the input voice from the CN is retained through the AEC module of the TC. After a period of delay, the remote input voice from the CN is compared with the local voice from the MS. If the codes of similar characteristics exist, it is considered that the local voice is the echo of the remote voice. Then, the echo is handled nonlinearly and replaced with comfort noise. In this manner, the original voice from the MIC is canceled, and therefore the user experience is improved.

Enhancement GBSS8.1

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The AEC algorithm performance is optimized. GBSS14.0 The accuracy of echo identification and cancellation is increased by 10%, which is calculated by algorithm simulation. The negative impact of echo cancellation on speech quality is decreased by 15%, which is calculated by algorithm simulation. 

A counter is provided to measure the number of echo occurrences.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-118602 A over IP GBFD-118622 A IP over E1/T1 GBFD-115701 TFO GBFD-115702 TrFO GBFD-117701 BSC Local Switch GBFD-117702 BTS Local Switch Dependency on other NEs None

1.1.4 GBFD-115603 Automatic Noise Restraint (ANR) Availability This feature was introduced in GBSS7.0.

Summary The ANR feature constrains the background noise during the call, reduces the receive level of the noise, and therefore increases the signal-to-noise ratio (SNR).

Benefits By suppressing the background noise during the call, the ANR makes the voice clear, improving the user experience.

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Description The ANR distinguishes voice information from background noise based on the characteristics of the input speech signal in different time domains and frequency domains. Then, the ANR reduces and suppresses the background noise according to a certain algorithm. By reducing the receive level of the noise and increasing the SNR, the ANR improves the user experience without affecting the authentic voice.

Enhancement GBSS8.1 The ALC algorithm performance is optimized. GBSS14.0 The efficiency for suppressing noise of the same type for a second time and suppressing unstable noise is improved. The capability to distinguish voice signals and music is significantly improved. 

A counter is provided to measure the number of times noise occurs at different levels.


1.1.5 GBFD-115701 TFO Availability This feature was introduced in GBSS6.1.

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Summary With this feature, the TFO frames are transparently transmitted and encoding/decoding is bypassed through the bit stealing scheme between the TCs at two ends. Therefore, the process of encoding/decoding is reduced once.

Benefits The speech signals deteriorate with each encoding/decoding. Therefore, using TFO to bypass encoding/decoding can improve the voice quality. In the case of encoding/decoding of lower rate, the voice quality is more evidently improved.

Description For traditional mobile network system without TFO, the voice signal is encoded by the MS on one side and transmitted over the radio interface. The signal is then decoded by the first TC unit. The decoded PCM data flow is transmitted to the second TC unit through the 64 kbit/s transmission link for encoding. After being encoded, the data is transmitted to the MS on the other side over the radio interface for decoding. During the whole conversation, the speech is transcoded twice, which is called tandem operation. Transcoding Functions

PLMN A MS/UE

Encoding

Transcoding Function


Compressed Speech

Decoding

ITU-T G.711 A-Law/-Law

Encoding

PLMN B MS/UE

Compressed Speech

Decoding

The TFO feature can reduce the speech signal degradation caused by tandem operation, improving the voice quality. When the calling MS and the called MS use the same speech version, the TFO link is established through the in-band signaling negotiation. In addition, the least significant bit (or the second least significant bit) is stolen to seize the 8 kbit/s (or 16 kbit/s) sublink of the PCM transmission link for transparent transmission of TFO frames and bypass TC encoding/decoding. In this manner, the speech signal is encoded at the MS initiating the call and decoded at the MS terminating the call for only once. Therefore, the degradation of the speech signals due to tandem operation is reduced and the voice quality is improved. This process is called tandem free operation (TFO). Transcoding Functions Bypassed

PLMN A MS/UE



Compressed Speech

Encoding

PLMN B MS/UE

Decoding

Enhancement GBSS8.1 The AMR TFO is supported. GBSS9.0

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Conversion between the FR and HR in the TFO: During the negotiation of the TFO, if the channel (FR or HR) used by the called party is different from the channel (HR or FR) used by the calling party, the call is handed over from the FR channel to an HR channel before the TFO. This feature improves the voice quality of the HR call.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features When a call using TFO feature, the following features cannot be used together: GBFD-115601 Automatic Level Control (ALC) GBFD-115602 Acoustic Echo Cancellation (AEC) GBFD-115603 Automatic Noise Restraint (ANR) GBFD-115703 Automatic Noise Compensation (ANC) GBFD-115704 Enhancement Packet Loss Concealment (EPLC) GBFD-115506 AMR Coding Rate Threshold Adaptive Adjustment GBFD-117702 BTS Local Switch AMR Rate Adaptation Under BTS Local Switch GBFD-117701 BSC Local Switch AMR Rate Adaptation Under BSC Local Switch Dependency on other NEs None

1.1.6 GBFD-115702 TrFO Availability This feature was introduced in GBSS8.0.

Summary With this feature, the calling MS and called MS use the same speech coding scheme. Therefore, the speech signal is coded at the calling MS once and decoded at the called MS once. This can solve the problem that the TRAU repeatedly codes and decodes the speech signal.

Benefits This feature provides the following benefits: 

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The TrFO feature enables the calling MS and called MS to use the same speech coding, which prevents the repeated coding and decoding during the MS-MS call process. This provides better speech quality for users.


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

In addition, the TRAU is not involved in the TrFO, saving the TC resources.



Repeated coding and decoding

Description In the traditional MS-MS call process where the TFO/TrFO is not adopted, the speech signal is coded at the calling MS, transmitted on the Um interface, and is then decoded at the first TRAU. The decoded PCM data flow is transmitted on the 64 kbit/s link to the second TRAU for coding and is then transmitted on the Um interface to the called MS for decoding. In the MS-MS call process, the coding and decoding are continually performed twice. This is referred to as repeated coding and decoding. 

Overview of TrFO The TrFO feature enables the calling MS and called MS to use the same speech coding. Therefore, the speech signal is coded at the calling MS once and decoded at the called MS once. This solves the problem of speech signal damage in repeated coding and decoding, improving the signal quality. In the GSM network, the coding capability of each cell can be dynamically configured. The coding scheme of the Um interface is determined by the BSS. When implementing the TrFO, the MSC server selects the speech version supported by the cells where the calling MS and called MS are located based on the coding capability of the cells. Then, the MSC sets the expected speech version to a highest value. In this way, the TrFO can be successfully implemented. 1) The BSC selects the speech version according to the Preferred Codec List carried in the assignment request sent by the MSC. 2) To improve the success rate of TrFO, the BSC sends the Complete Layer 3 Information message carrying the coding schemes supported by the cells to the MSC. 3) To perform the TrFO services on the established calls, the MSC sends the INTERNAL HANDOVER ENQUIRY message carrying the specified Speech Codec to the BSC to trigger the intra-BSC handover.



Differences between TrFO and TFO Both TrFO and TFO use the speech compression in the CN. Both features avoid the repeated code conversions during the MS-MS call and improve the QoS. The two features, however, are different from each other. TFO is enabled, disabled, and controlled by the TRAU after a call is established. When the encoder and decoder use the same coding/decoding scheme, the TFO is enabled to transmit the compressed speech. TrFO, however, does not require the TRAU. It uses the OoBTC to negotiate the coding/decoding type of both the calling MS and called MS before the call is established. Then, the compressed speech is transmitted after the call is established. If the requirement for TrFO is not met, it takes some time to configure the TRAU for restoring the PCM coding/decoding. Without the TRAU, the call fails. In TFO, however, the PCM coding is immediately used when the requirement for TFO is not met. Therefore, the speech quality is not affected.

Enhancement None


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Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-118602 A over IP GBFD-118622 A IP over E1/T1 Dependency on other NEs The CN must support this feature.

1.1.7 GBFD-115703 Automatic Noise Compensation (ANC) Availability This feature was introduced in GBSS9.0.

Summary Through the assessment of the background noise of the local end and the speech level of the peer end, this feature adaptively increases the speech volume of the peer end if the background noise of the local end is heavy. Therefore, the ratio of the peer end speech to the background noise of the local end is increased and the speech quality is improved.

Benefits Good speech quality is a basic requirement for a superior network. It is also the basic requirement of the customer and helps in testing the product of the equipment manufacturers. The problems such as acoustic echo, background noise, and packet loss must be solved to ensure the speech quality. In addition, the gain of the signals should be controlled. Different manufacturers have different algorithms and features to solve these problems. Huawei GBSS uses the ANC feature to improve the speech quality in the scenarios with heavy background noise such as in the downtown, marketplace, and cinema. Therefore, the user satisfaction is increased and a network with enhanced performance is provided.

Description The ANC compensates the noise through the algorithm. Through the assessment of the background noise of the local end and the speech level of the peer end, this feature adaptively increases the speech volume of the peer end if the background noise of the local end is heavy. Therefore, the ratio of the peer end speech to the background noise of the local end is increased so that the listener can clearly hear the speaker. This feature is disabled by default. The ANC threshold is the ratio of the peer end speech to the background noise of the local end, which can be manually configured. The maximum adjustment range is the maximum gain of the ANC, which can also be manually configured. For the speech handling, refer to the ITU-T G.169 specifications. This feature is a feature of the TC devices and cannot be used together with the TrFO or TFO.

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Enhancement GBSS14.0 A counter is provided to measure the number of times SNRs occur at different levels.


1.1.8 GBFD-115704 Enhancement Packet Loss Concealment (EPLC) Availability This feature was introduced in GBSS9.0.

Summary This feature applies to the EFR, AMR FR, and AMR HR speech versions. When the BSS receives the speech coding, the frames of the lost packets can be recovered and compensated through the algorithm. Therefore, the anti-interference capabilities of the EFR, AMR FR, and AMR HR speech versions and the speech quality are improved.

Benefits With this feature, the frames of the lost packets can be recovered and compensated. This, to a certain extent, solves the problem of speech frame loss during transmission and in a poor radio environment. Therefore, the speech quality is improved, the user satisfaction is improved, and a network with enhanced performance is provided. In the case of packet loss of different severities, the MOS can be increased by 0 to 0.2.

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Description The problems such as acoustic echo, background noise, and packet loss must be solved to ensure the speech quality. In addition, the gain of the signals should be controlled. Different manufacturers have different algorithms and features to solve these problems. This feature uses the patented algorithm to restore the lost frames during the transmission and in a poor radio environment based on the information about the previous frame. This implements the compensation for the frames of the lost packets. This feature is a feature of the TC devices. It is used to process the AMR speech and controlled by a switch. This feature cannot be used together with the TrFO or TFO because the TC is not involved in the TrFO or TFO.

Enhancement GBSS13.0 The packet loss prediction algorithm is optimized so that the received voice gets closer to the original voice in fidelity, improving user experience.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-115501 AMR FR or GBFD-115502 AMR HR This feature is mutually exclusive with the following features: GBFD-118602 A over IP GBFD-118622 A IP over E1/T1 GBFD-115701 TFO GBFD-115702 TrFO GBFD-117701 BSC Local Switch GBFD-117702 BTS Local Switch It is recommended working with the following features: GBFD-115603 Automatic Noise Restraint (ANR) Dependency on other NEs None

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1.1.9 GBFD-115711 EVAD Availability This feature was introduced in GBSS13.0.

Summary This feature helps telecom operators promote their value-added music services.

Benefits This feature enhances the encoding effect of music (such as ring back tone (RBT) service and voice information service) that uses the EFR, AMR FR, or AMR HR coding schemes and therefore improves user experience.

Description The earlier Voice Activity Detection (VAD) algorithm may consider soft music as silence and mistakenly encode music in the downlink. This affects user experience. The Huawei proprietary Enhanced VAD (EVAD) algorithm increase music recognition accuracy. It greatly reduces the probability that music is mistakenly considered as silence, improving user experience.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-115501 AMR FR GBFD-115502 AMR HR GBFD-113301 EFR GBFD-114801 Discontinuous Transmission (DTX)-Downlink If EVAD is enabled for a call, the following features cannot be enabled at the same time: GBFD-115701 TFO GBFD-115702 TrFO GBFD-117701 BSC Local Switch

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GBFD-117702 BTS Local Switch This feature cannot be used with any of the following features: GBFD-118602 A over IP GBFD-118622 A IP over E1/T1 Dependency on other NEs None

1.1.10 GBFD-116801 Voice Quality Index (VQI) Availability This feature was introduced in GBSS7.0.

Summary The voice quality index (VQI) feature provides a direct method of measuring the voice quality of the radio network. By measuring the uplink VQI and downlink VQI, the voice quality of the network is quantified, which provides a reference for future network optimization.

Benefits The VQI can measure the voice quality of the network rapidly and effectively and therefore provide a reference for network optimization.

Description The VQI establishes the mapping between the radio network performance and voice quality. The VQI value, which helps learn the voice quality, is calculated based on the parameters related to the radio quality of the uplink/downlink speech signals. The MOS analysis method is applied in VQI to measure the voice quality. The MOS is used to assess the quality of the middle-rate and low-rate voice coding. The MOS value ranges from 1 to 5. Based on the MOS analysis method, Huawei further divides the voice quality into 11 levels. The VQI is obtained through the analysis of the BER, FER, LFE, and CODE of the uplink/downlink speech signal. In this manner, the voice quality is quantified to facilitate the identification of the voice problem and network optimization.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features

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Downlink VQI depends on the following feature: GBFD-117501 Enhanced Measurement Report (EMR) Dependency on other NEs The MS must support this feature.

1.1.11 GBFD-115708 Um Interface Speech Frame Repairing Availability This feature was introduced in GBSS13.0.

Summary This feature automatically repairs the bit-error speech frames over the Um interface, improving the voice quality. The feature is implemented by applying an enhanced decoding technique to the Um interface.

Benefits This feature helps improve the voice quality. The improvement is more significant when the carrier-to-interference ratio (C/I) is low.

Description When the bit error rate (BER) is high and the C/I is low, voice quality will deteriorate if bit-error voice frames are discarded. To solve this problem, an enhanced decoding technique is adopted to repair the erroneous speech frames over the Um interface. This technique increases the success rate of voice decoding, improving the voice quality under low C/I. After this feature is applied, the mean opinion score (MOS) can be increased by 0.1 to 0.2 under low C/I.

Enhancement None

Dependency Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on BSC hardware None Dependency on other GBSS features None Dependency on other NEs None

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1.2 AMR Package 1.2.1 GBFD-115501 AMR FR Availability This feature was introduced in GBSS6.1.

Summary In a situation where interference is likely to occur, better voice quality can be provided if the system uses AMR FR. In the same conditions, the voice quality in AMR FR is the same as or better than the voice quality in EFR.

Benefits This feature has the following benefits: 

Increases the capacity of the system in physical areas.



Enhances the anti-interference capability to adapt to tight frequency reuse.



Improves the network indexes in an increasingly complex radio environment in combination with the frequency hopping technology.



Provides a better voice quality for the subscriber.

Description The AMR is an integration of multiple voice encoding/decoding rates. With different encoding/decoding rates, the voice code streams of different rates are yielded. The AMR enables the BTS and MS to select an appropriate encoding/decoding algorithm and to adjust the encoding rate based on the specific radio environment. Therefore, the voice quality of the entire wireless communication system is improved. When there is a lot of interference on the radio channels, better voice quality can be provided in AMR FR than in EFR or FR. In addition, the system in AMR FR has a higher anti-interference capability to adapt to tight frequency reuse. In the wireless communication system, the higher the original speech rate involved in channel encoding, the more the information about the speech characteristics carried in the coded stream and therefore the higher the fidelity of the speech. However, the redundant information in the coded stream decreases, and therefore the coded stream becomes more interference sensitive. In a poor wireless communication environment, bit errors occur easily and the speech frames may be lost. Therefore, voices may be discontinuous. If the original speech rate involved in channel encoding is reduced, more redundant information is carried in the coded stream. Then the coded stream has strong anti-interference and error correction capabilities. Therefore, the continuity of voice can be improved. The AMR FR provides a selection of multiple coding rates from 4.75 kbit/s to 12.2 kbit/s, as listed in the following table. Channel

Coding Rate

TCH/AFS

12.2 kbit/s 10.2 kbit/s

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Coding Rate 7.95 kbit/s 7.40 kbit/s 6.70 kbit/s 5.90 kbit/s 5.15 kbit/s 4.75 kbit/s

Enhancement GBSS8.1 The anti-interference capability of signaling transmission is enhanced in GBSS8.1. If the original speech rate involved in channel encoding is reduced, the coded stream can contain more redundant information. Then the coded stream has stronger anti-interference and error correction capabilities and the voice continuity is improved as a result. The signaling transmission performance, however, is not improved. After this feature is enabled, the transmit power is increased during signaling transmission to increase the success rate of signaling transmission. This can avoid voice interruption concerned with signaling transmission in poor radio environment. GBSS13.0 E-coder is introduced in GBSS13.0 and it is used in A over TDM transmission. E-coder improves the AMR FR speech quality by using the enhanced spectrum technique and LSP exact-calculate technique. In this way, E-coder increases the Mean Opinion Score (MOS) by 0.05 to 0.12. In A over IP or TFO, E-coder is not supported.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It is recommended working with the following features: GBFD-115503 AMR Power Control Dependency on other NEs The MS and the CN must support this feature.

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1.2.2 GBFD-115502 AMR HR Availability This feature was introduced in GBSS6.1.

Summary In a situation where interference is likely to occur, better voice quality can be provided if the system uses AMR HR. In the same conditions, the voice quality in AMR HR is the same as or better than that in HR. If the AMR HR feature is enabled, the half-rate speech feature must be enabled at the same time.


Increases the capacity of the system in physical areas.



Enhances the anti-interference capability to adapt to tight frequency reuse.



Improves the network indexes in an increasingly complex radio environment in combination with the frequency hopping technology.



Provides a better voice quality for the subscriber.

Description In a situation where interference is likely to occur, better voice quality can be provided if the system uses AMR HR. In the same conditions, the voice quality in AMR HR is the same as or better than that in HR. Therefore, if the communication quality meets the requirements, the AMR HR can be widely used to increase the system capacity. When much interference exists and the voice quality decreases, the system automatically switches to the AMR FR so that the voice quality and the system capacity are balanced in real time. In this manner, the system can provide good voice quality to subscribers when the system capacity is increased. The AMR HR provides a selection of multiple coding rates, as listed in the following table. Channel

Coding Rate

TCH/AHS

7.40 kbit/s 6.70 kbit/s 5.90 kbit/s 5.15 kbit/s 4.75 kbit/s

Enhancement GBSS8.1 The TCH/AHS 7.95 kbit/s coding rate is supported in GBSS8.1.

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The BTS using the Abis over IP or Abis transmission optimization function can provide the speech services with the coding rate of AMR HR 7.95 kbit/s. The following table lists multiple coding rates of the AMR HR. Channel

Coding Rate

TCH/AHS

7.95 kbit/s 7.40 kbit/s 6.70 kbit/s 5.90 kbit/s 5.15 kbit/s 4.75 kbit/s

Enhanced anti-interference capability of signaling transmission: If the original speech rate involved in channel encoding is reduced, the coded stream can contain more redundant information. Then the coded stream has stronger anti-interference and error correction capabilities and the voice continuity is improved as a result. The signaling transmission performance, however, is not improved. After this feature is enabled, the transmit power is increased during signaling transmission to increase the success rate of signaling transmission. This can avoid voice interruption due to signaling transmission in poor radio environment. GBSS13.0 E-coder is introduced in GBSS13.0 and it is used in A over TDM transmission. E-coder improves the AMR HR speech quality by using the enhanced spectrum technique and LSP exact-calculate technique. In this way, E-coder increases the Mean Opinion Score (MOS) by 0.05 to 0.12. In A over IP or TFO, E-coder is not supported.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on: GBFD-113401 Half Rate Speech It is recommended working with the following features: GBFD-115503 AMR Power Control Dependency on other NEs The MS and the CN must support this feature.

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1.2.3 GBFD-115503 AMR Power Control Availability This feature was introduced in GBSS6.1.

Summary Using different AMR power control algorithms, this feature can provide better anti-interference capability, larger network capacity, and better voice quality.


Reduces the transmit power and prolongs the standby time of the MS.



Reduces the network interference and improves the frequency usage.



Improves the network quality.

Description The AMR speech coding scheme can select one of the coding rates according to the radio channel quality to achieve an optimized combination of speech coding rate and channel coding rate. In this manner, the AMR speech coding scheme can provide the best voice quality in the current radio environment and meet the communication requirements in various radio environments. The coded stream contains more redundant information. Then the coded stream has stronger anti-interference and error correction capabilities and the voice continuity is improved as a result. The system automatically decides whether to adopt the AMR. If the system uses the AMR, the power control strategy for the AMR calling is different from that for the non-AMR calling. In this manner, the network interference is reduced, the BTS transmit power is saved, and the standby time of MS is prolonged.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It is recommended working with the following features: GBFD-115501 AMR FR GBFD-115502 AMR HR Dependency on other NEs

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None

1.2.4 GBFD-115504 AMR FR/HR Dynamic Adjustment Availability This feature was introduced in GBSS6.1.

Summary Through the dynamic adjustment of AMR HR and AMR FR, the cell capacity and the voice quality are balanced.


Less maintenance work is required because the system can automatically adjust the ratio of AMR FR to AMR HR based on the network capacity and quality.



This feature expands the network capacity and reduces the network deployment cost without degrading the voice quality.

Description Through the dynamic adjustment of AMR HR and AMR FR, this feature helps to balance the cell capacity and the voice quality. After completing the initial voice coding after setting up a call, the BSS calculates the radio quality index (RQI) based on the uplink signal quality measured by the BTS. Then, based on the uplink quality, the code sets activated by the BSC, and the corresponding thresholds, the system determines the encoding/decoding scheme used for the uplink. In addition, the system dynamically adjusts the voice coding rate in the uplink, and informs the MS to use the selected voice coding rate. According to the RQI and parameters such as network capacity, the BSS decides whether to enable the AMR FR/HR dynamic adjustment in the cell to balance the voice quality and the cell capacity. The AMR FR/HR dynamic adjustment in different radio environments and capacity configurations helps to balance the voice quality and the cell capacity. Before enabling the AMR FR/HR dynamic adjustment feature, you must enable the half rate speech and AMR HR features.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features Issue V0.5 (2011-08-30)


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None Dependency on other NEs None

1.2.5 GBFD-115505 AMR Radio Link Timer Availability This feature was introduced in GBSS8.0.

Summary The radio link timer is used for the detection of the radio link quality. When the timer expires due to poor radio link quality, the system deactivates the radio channel and interrupts the conversation. In this manner, the timer can improve the channel utilization and prevent channels with poor quality from occupying radio channel resources for a long time.


Prolongs the duration of the AMR voice service with high anti-interference capability and therefore reduces the call drop rate by setting the radio link timer of AMR voice service and that of non-AMR voice service separately.



Improves the user experience and increases the operators' revenue by prolonging the AMR call duration in the network of poor radio link quality.

Description This feature provides a special radio link timer for AMR calls. AMR calls enjoy higher robustness than common calls. Therefore, when a common call fails due to poor radio link quality, the AMR voice service can maintain good conversation quality. If the radio link timer of the AMR call and that of a common call are set to the same value, the chance of AMR call drop increases and the user experience deteriorates. In this case, you should set the AMR radio link timer to a larger value so that the AMR call endures the poor radio environment and the call drop rate is reduced. You can configure the radio link timers for the AMR HR and the AMR FR separately.

Enhancement None


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None Dependency on other NEs None

1.2.6 GBFD-115506 AMR Coding Rate Threshold Adaptive Adjustment Availability This feature was introduced in GBSS8.1.

Summary Through the setting of the target voice quality and the real-time monitoring of the current voice quality, the GBSS devices can adjust the coding rate adjustment threshold so that the AMR speech can select an appropriate coding rate to enable the voice quality to approach the target voice quality.


Enables the AMR speech to select an appropriate coding rate.



Ensures the performance of the AMR speech.

Description The AMR speech rate set consists of multiple coding rates. Based on the measured receive level, receive quality, and carrier-to-interference ratio, and in combination with the algorithm, the BTS and MS adjust the AMR call control parameters to select a speech source coding rate that adapts to the existing radio environment. The appropriate selection helps achieve an optimal combination of the channel quality and speech coding rate and improve the voice quality to the greatest extent in the existing radio environment. Generally, network planning engineers set the AMR speech coding rate adjustment threshold to a fixed value after assessing the radio channel quality. If the radio channel quality changes or the network planning engineers’ assessment of the radio channel quality is inaccurate, the AMR speech will fail to select an appropriate coding rate. The AMR voice quality is then affected. Based on the setting of the target voice quality and the real-time monitoring of the current voice quality, this feature adjusts the coding rate adjustment threshold so that an appropriate coding rate can be selected to ensure the AMR voice quality. The AMR coding rate adjustment threshold involves the adjustment threshold on the uplink and the adjustment threshold on the downlink. Uplink: After comparing the uplink quality indication with the coding rate adjustment threshold, the BTS obtains an appropriate coding rate for the MS. Then, the BTS sends this coding rate to the MS through the in-band signaling for adjusting the coding rate. Downlink: After comparing the downlink quality indication with the coding rate adjustment threshold, the MS obtains an appropriate coding rate for the BTS. Then, the MS sends this coding rate to the BTS through the in-band signaling. The BTS comprehensively considers Issue V0.5 (2011-08-30)


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the restrictions on the network side and then adjusts the downlink coding rate. Meanwhile, the BTS notifies the MS of the selected downlink coding rate so that the MS uses the same coding rate for decoding. GBSS8.1 supports the AMR coding rate threshold adaptive adjustment on the uplink.

Enhancement GBSS9.0 AMR coding rate threshold adaptive adjustment on the downlink: The AMR coding rate threshold is used to control the selection of the AMR coding rate. When the threshold is fixed, the AMR speech cannot select an appropriate coding rate if the radio channel quality changes or the network planning engineers’ assessment of the radio channel quality is inaccurate. The AMR voice quality is then affected. This feature enhancement supports the adaptive adjustment of the AMR coding rate adjustment threshold on the downlink based on the speech quality. The BTS obtains the frame erase ratio (FER) of the current call based on the enhanced measurement report (EMR) submitted by the MS and then estimates the speech quality (SQ). If the estimated speech quality is distinct from the target speech quality, you can infer that the configured threshold is inappropriate. Then, the GBSS adjusts the threshold based on certain algorithm. The BTS sends the adjusted AMR coding rate threshold to the MS through the robust AMR traffic synchronized control channel (RATSCCH). Subsequently, the MS adjusts the AMR coding rate during the call on the basis of this coding rate adjustment threshold.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other functions of the GBSS "AMR coding rate threshold adaptive adjustment on the downlink" depends on the following feature: GBFD-117501 Enhanced Measurement Report (EMR) This feature is mutually exclusive with the following features: GBFD-115701 TFO GBFD-117702 BTS Local Switch GBFD-117701 BSC Local Switch Dependency on other NEs None

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1.2.7 GBFD-115507 WB AMR Availability This feature was introduced in GBSS9.0.

Summary Wide Band AMR (WB AMR) is a coding scheme, which significantly improves the speech quality. WB AMR supports the rates of 6.60 kbit/s, 8.85 kbit/s, and 12.65 kbit/s.

Benefits 

Compared with the narrow band AMR, WB AMR achieves better speech quality.



Because the speech quality is improved, subscribers tend to spend more time on the call. This increases the revenue of the operators.



The better speech quality of WB AMR than that of PSTN assists the wireless operators in prompting subscribers of fixed networks to switch over to wireless networks.

Description WB AMR is a coding scheme that can significantly improve speech quality. With WB AMR, the sampling rate is increased to 16 kHz and the speech frequency range is extended to 0.05–7 kHz. WB AMR provides clear and loud voice and high-quality speech compared with the narrow band AMR with the sampling rate of 8 kHz and the speech frequency range between 200 Hz and 3400 Hz. WB AMR adopts the Guassian Minimum Shift Keying (GMSK) mode and supports the rates of 6.60 kbit/s, 8.85 kbit/s, and 12.65 kbit/s on full-rate TCHs. To achieve ideal speech quality, the end-to-end WB AMR call should be implemented. The one-end WB AMR call requires two-time PCM coding scheme, which adversely affects the speech quality. When the end-to-end WB AMR and the TFO are used together, a call needs only one-time coding scheme, which helps to maintain high speech quality. If the end-to-end WB AMR call cannot be established, the BSC will set up an AMR FR call instead of the one-end WB AMR call because the speech quality and robustness of the one-end WB AMR call are not necessarily better than those of the AMR FR call. Huawei BSS equipment supports the WB AMR feature in Abis over TDM, Abis over IP, and Abis over HDLC transmission modes.

Enhancement None


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None Dependency on other NEs The MS, BTS, and MGW/MSC server must support this feature.

1.3 Voice Capacity 1.3.1 GBFD-113401 Half Rate Speech Availability This feature was introduced in GBSS6.1.

Summary With this feature, the speech coding rate is reduced to half the full-rate speech coding rate through a new speech coding algorithm. In this manner, the physical channel carrying the service of one MS is able to carry the services of two MSs.

Benefits This feature enables the operator to expand the network capacity and improve the frequency usage without increasing the hardware investment. In addition, a higher traffic volume can be carried on an E1.

Description With the increase of the GSM subscribers, the frequency resources of the existing GSM network are insufficient. The half-rate service helps increase the number of speech channels configured for one TRX. This increases the frequency usage without greatly reducing the voice quality and expands the network capacity without increasing the hardware investment. The half-rate service has the following benefits: 

Saving the resource on the Um interface The half-rate speech coding rate is reduced to half the full-rate speech coding rate through the new coding algorithm. In addition, the multiframes on the Um interface are used by two MSs with one MS receiving the even-numbered multiframes and the other MS receiving the odd-numbered multiframes. In this manner, the physical channel that supports one MS in the full-rate service can carry two MSs in the half-rate service. The entire network interference is reduced because fewer timeslots are seized.



Saving the resource on the Abis interface In half-rate service, one 16 kbit/s channel carries two calls on the Abis terrestrial circuit. In this manner, a higher traffic volume is carried on the terrestrial link. The load on the RSL, however, is heavy because one TRX carries a higher traffic volume. Therefore, when configuring signaling multiplexing, use the 2:1 mode instead of the 4:1 mode.

Enhancement GBSS7.0 The half-rate service can be used to save the resources on the Ater interface.

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When the Flex Ater feature is enabled, the 8 kbit/s circuit is allocated to the half-rate call over the Ater interface. In this manner, the transmission resources on the Ater interface are saved. GBSS8.1 The half-rate channel is preferentially allocated when transmission resource congestion occurs on the Abis interface. The half-rate channel is allocated based on the resource congestion condition on the Abis interface. The load on the Abis interface is calculated in real time. When the resources on the Abis interface are congested, the BSC preferentially allocates a half-rate speech channel to a call to relieve the resource congestion. The dynamic conversion between half-rate and full-rate channels is triggered when resource congestion occurs on the Um or Abis interface. The dynamic conversion between half-rate and full-rate channels is triggered based on the resource congestion condition on the Um or Abis interface. When the resources are congested, the conversion from the full-rate call to the half-rate call can relieve the congestion.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It is recommended working with the following features: GBFD-117301 Flex Abis GBFD-116901 Flex Ater Dependency on other NEs The MS and the MSC must support this feature.

1.3.2 GBFD-113402 Dynamic Adjustment Between FR and HR Availability This feature was introduced in GBSS6.1.

Summary With this feature, the full-rate (FR) channels and the half-rate (HR) channels are dynamically converted to automatically adapt to the proportions of FR channels and HR channels in a cell during the call. In this manner, the situation in which one type of channel is congested whereas the other type of channel is idle can be prevented.

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Improves the channel usage because the channel is adjusted according to the requirement of the call.



Reduces the workload of the network OM personnel because the full-rate channel and the half-rate channel are automatically converted.

Description If the half-rate channel is configured, the full-rate channel and the half-rate channel are dynamically converted as required to automatically adapt to the proportions of FR channels and HR channels in a cell during the call. In this manner, the situation in which one type of channel is congested whereas the other type of channel is idle can be prevented. In addition, the proportions of FR channels and HR channels in a cell can be controlled through related parameters. During the call, the channel is allocated based on the resources in the MS, MSC, and BSC. If a half-rate channel is required but is unavailable, a full-rate channel is converted into two half-rate channels. If a full-rate channel is required but is unavailable, the half-rate channels are converted into full-rate channels. Each time a call is released, the attributes of the channel are not changed and the converted channel is not immediately switched back to its original form. If the load of the cell is normal, the proportions of FR channels and HR channels in a cell are maintained at a certain value through the automatic adjustment of the calls. The conversion between the half-rate channels and the full-rate channels occurs when the load of the cell is high or when the congestion occurs.

Enhancement GBSS14.0 If a policy is used that preferentially allocates HR channels to an MS, the BSC determines whether the receive level is higher than the preset threshold during a handover or a channel assignment. If the receive level is higher than the threshold, the BSC allocates HR channels to the MS. If the receive level is lower than the threshold, the BSC preferentially allocates FR channels to the MS.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following feature: GBFD-113401 Half Rate Speech Dependency on other NEs

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None

1.3.3 GBFD-115522 Dynamic HR/FR Adaptation Availability This feature was introduced in GBSS8.1.

Summary With this feature, the established calls can be handed over between half-rate channels and full-rate channels based on the usage of channel resources. In this manner, the balance between the network quality and the cell capacity is maintained.


When the traffic volume is low, calls are handed over from half-rate channels to full-rate channels, improving the voice quality.



When the TCHs in a cell are insufficient, calls are handed over from full-rate channels to half-rate channels, increasing the cell capacity.

Description During call establishment, the network assigns a half-rate or a full-rate channel to the call based on the usage of the cell resources. In the case of a long-duration call, the usage of the cell resources may change: During the call establishment phase, if the TCH seizure rate is high, a half-rate channel is assigned to the call. After the call lasts for a period, many calls are released and the TCH seizure rate decreases. In this case, TCHs in the cell are sufficient and a full-rate channel can be assigned to the call to improve the voice quality. If the TCH seizure rate is low during the call establishment, a full-rate TCH may be assigned to the call. After the call lasts for a period, many calls access the cell and the TCH seizure rate increases. In this case, the available TCHs in the cell are insufficient. If the dynamic adjustment between full-rate and half-rate channels is enabled, the half-rate/full-rate channels of established calls can be adjusted based on the usage of cell resources. When the TCHs in a cell are sufficient, full-rate channels are preferably assigned to new calls and calls with poor communication quality can be handed over from half-rate channels to full-rate channels, improving the communication quality. When the TCHs in a cell are insufficient, half-rate channels are preferably assigned to new calls and calls with good communication quality may be handed over from full-rate channels to half-rate channels, increasing the cell capacity. When this feature is enabled, the half-rate speech feature needs to be enabled at the same time.

Enhancement None

Dependency Dependency on BSC hardware

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None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs None

1.3.4 GBFD-115830 VAMOS Availability This feature was introduced in GBSS13.0.

Summary Voice services over Adaptive Multi-user Orthogonal Subchannels (VAMOS) is a feature based on which two users are multiplexed onto one HR channel to increase network capacity. VAMOS helps increase the network capacity.

Benefits In a network where refarming is applied and speech channels are insufficient, the GSM network capacity can be increased through software without changing the existing GSM network architecture. The network capacity increase by VAMOS is 20% in the scenarios that 100% SAIC MS penetration rate and 4x3 frequency reuse pattern.

Description VAMOS is a technology to increase GSM network capacity. The network capacity is increased by using HR channels and can be increased further by VAMOS based on the FR channels. Tests tell that the VAMOS performance depends on the penetration rate of the MS and the frequency reuse pattern. VAMOS reduces network quality while increasing network capacity. The reduced network quality should be tolerable for operators because the quality standards for a GSM network with VAMOS are lower than those for a legacy GSM network. The following table lists the VAMOS gains. Frequency Reuse Pattern

4x3

SAIC MS Ratio (%)

VAMOS Gain (%)

50%

10%-15%

75%

15%-22%

100%

20%-30%

50%

7%-12%

75%

10%-18%

3x3

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100%

15%-25%

50%

5%-10%

75%

7%-15%

100%

10%-20%

The preceding table tells that the network capacity is not increased when the frequency reuse is tight. Therefore, VAMOS can be enabled only when the frequency reuse is loose.

Enhancement GBSS14.0 1.

The radio resource management (RRM) algorithm is optimized for networks deployed with VAMOS. The optimization reduces the negative impact of VAMOS on the call drop rate and handover success rate. In addition, the channel preemption and timeslot combination policies are modified to reduce the negative impact of VAMOS on ongoing services.

2.

Huawei BSCs work with the Huawei M2000 to enhance the performance of the features VAMOS Mute SAIC MS Identification (feature ID: GBFD-115831) and VAMOS Call Drop Solution (feature ID: GBFD-115832). This enables the BSCs to share information about SAIC MS capabilities, reducing the negative impact of the two features on KPIs. In addition, BSC reliability is improved because manual intervention is minimized.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It depends on the following features: GBFD-117601 HUAWEI III Power Control Algorithm GBFD-115502 AMR HR or GBFD-113401 Half Rate Speech GBFD-118103 Network Support SAIC GBFD-117301 Flex Abis (in TDM transmission mode) GBFD-118601 Abis over IP or GBFD-118611 Abis IP over E1/T1 (in IP transmission mode) This feature is recommended working with the following features: GBFD-113501 A5/1 and A5/2 Ciphering Algorithm GBFD-113503 A5/3 Ciphering Algorithm GBFD-114801 Discontinuous Transmission (DTX)-Downlink

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GBFD-114803 Discontinuous Transmission (DTX)-Uplink This feature is mutually exclusive with the following features: GBFD-117501 Enhanced Measurement Report (EMR) GBFD-117001 Flex MAIO GBFD-510104 Multi-site Cell GBFD-113521 A5/1 Encryption Flow Optimization GBFD-510101 Automatic Frequency Correction (AFC) GBFD-114001 Extended Cell Dependency on other NEs MS

1.3.5 GBFD-115831 Mute SAIC MS Identification Availability This feature was introduced in GBSS13.0.

Summary Mute SAIC MS Identification is a function based on which the SAIC-capable MSs that do not report their SAIC capability to the BSS are identified so that the MSs can use VAMOS.

Benefits This feature helps identify the MS capability correctly so that the SAIC-capable MSs can use VAMOS. This increases the number of MSs that use VAMOS, increasing the network capacity.

Description Some mute SAIC MSs support SAIC but do not report the SAIC capability to the BSS. As a result, the number of MSs that can be multiplexed by VAMOS is smaller than what it actually is, and therefore the network capacity is limited. This feature helps distinguish SAIC-capable MSs from SAIC-incapable MSs so that the SAIC-capable MSs can use VAMOS.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware

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For the dependency on BTS hardware, see the GBSS14.0 Feature List. This feature is used together with the following features: 

GBFD-115830 VAMOS

This feature is recommended working with the following features: 

GBFD-113501 A5/1 and A5/2 Ciphering Algorithm



GBFD-113503 A5/3 Ciphering Algorithm

This feature is mutually exclusive with the following features: 

GBFD-115701 TFO



GBFD-117702 BTS Local Switch



GBFD-117701 BSC Local Switch

Dependency on other NEs The MS must support this feature.

1.3.6 GBFD-115832 VAMOS Call Drop Solution Availability This feature was introduced in GBSS13.0.

Summary VAMOS Call Drop Solution is a function based on which call drops do not occur when the MS is paired with VAMOS so that the system capacity and voice quality are not affected.

Benefits With this feature, call drops no longer occur when the SAIC-capable MS use VAMOS. In this manner, the network capacity is increased and services remain normal.

Description Mainstream multi-mode MSs report the SAIC capability to the BSS. Call drops, however, frequently occur when the MSs use VAMOS. Tests tell that this is caused by defective automatic frequency control (AFC) of the MSs in the case of VAMOS multiplexing. This feature prevents call drops of SAIC-capable MSs. This feature involves the following processes: 1. The BSS distinguishes the normal SAIC-capable MSs (that experience call drops) from the defective ones (that do not experience call drops). 2. Processing is performed on the defective ones that do not experience call drops in the case of VAMOS multiplexing.

Enhancement None

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Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. This feature is used together with the following features: 

GBFD-115830 VAMOS

This feature is recommended working with the following features: 

GBFD-113501 A5/1 and A5/2 Ciphering Algorithm



GBFD-113503 A5/3 Ciphering Algorithm

This feature is mutually exclusive with the following features: 

GBFD-115701 TFO



GBFD-117702 BTS Local Switch



GBFD-117701 BSC Local Switch

Dependency on other NEs The MS must support this feature.

1.4 Cell Broadcast 1.4.1 GBFD-113601 Short Message Service Cell Broadcast (TS23) Availability This feature was introduced in GBSS6.1.

Summary The short message service cell broadcast (SMSCB) is a teleservice (TS23) through which all the MSs in the specified area can periodically receive messages.

Benefits The SMSCB can increase the revenue of the operator by providing weather forecast, stock information, and sales promotion information based on the location of the MS.

Description The SMSCB is a teleservice that periodically broadcasts messages to all the MSs in a specified area. Based on different settings, the MS can continuously or discontinuously receive short messages, such as weather forecast and traffic information.

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The SMSCB allows all the MSs in a specified area to receive short messages. The area may cover one or more cells, or the entire PLMN. The short messages from the cell broadcast center (CBC) are managed and scheduled in the CDB of the BSC, which sends the short messages to the BTS. The BTS then broadcasts the messages to all the MSs in a specified area at certain intervals. The CDB receives and stores the short messages, schedules and sends the messages according to a certain algorithm, and responds to the query from the CBC. The MS can receive the messages in DRX mode. That is, the MS can work discontinuously. Through a scheduling message, the BSC notifies the MS that no short message is sent during a period. Therefore, the MS needs to receive the short messages only in the specified period and does not need to detect the messages continuously. Therefore, the power consumption is reduced. The SMSCB supports the BTS flow control. That is, the order in which the short messages are sent is scheduled by the CDB, but the sending of the messages is implemented by the BTS. Each TRX of the BTS maintains one message buffer and periodically sends the cell broadcast short message on a specified channel. When the messages are not sent in time, the BTS reports the out-of-synchronization situation to the BSC through a LOAD IND message. By controlling the BTS flow, the CDB maintains the balance of the cell broadcast system and therefore meets the requirements of the message sending.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature and the following feature are mutually exclusive: GBFD-113602 Simplified Cell Broadcast Dependency on other NEs The CBC should be used.

1.4.2 GBFD-113602 Simplified Cell Broadcast Availability This feature was introduced in GBSS7.0.

Summary This feature is implemented by using a built-in cell broadcast processing module in the BSC in the case that a CBC is not used.

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Benefits Without a CBC, Huawei simplified cell broadcast feature supports the most commonly used standard cell broadcast services with low equipment costs and low OM costs, reducing the operator's CAPEX.

Description With the SMSCB function, short messages are broadcast to all MSs in one or several cells, or even in the entire PLMN. The MSs can receive the broadcast messages continuously or discontinuously. Generally, a CBC is responsible for managing and scheduling the SMSCB. Huawei simplified cell broadcast feature is performed through a built-in cell broadcast processing module in the BSC, reducing the equipment costs. Huawei simplified cell broadcast feature is performed to broadcast messages such as the cell name, weather forecast, and social welfare messages. These functions are described as follows: 

Information broadcast function Messages are broadcast, such as the BTS name, cell name, weather forecast, and any character string with a maximum of 80 characters.



Information timing broadcast function Cell broadcast messages are sent at specified intervals during a specified period of time.



Information management function The MML commands are used to start or stop sending the broadcast messages in specified cells or all cells, or stop sending a specified cell broadcast message. In addition, the cell broadcast status can be viewed by running the MML commands. In any period of time, a maximum of 16 cell broadcast short messages can be sent simultaneously in one cell.

Enhancement GBSS8.1 A maximum of 64 cell broadcast short messages can be sent simultaneously in one cell.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other NEs This feature and the following feature are mutually exclusive: GBFD-113601 Short Message Service Cell Broadcast (TS23) Dependency on other GBSS features

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None

1.5 GSM Trunking 1.5.1 GBFD-510301 Public Voice Group Call Service Availability This feature was introduced in GBSS8.1.

Summary The public voice group call service (VGCS) adopts the half-duplex mode and provides voice services for a group of predefined MSs in a predefined area.

Benefits With this feature, operators can provide a new half-duplex voice service for a group of subscribers to meet the requirement of dispatching service. This service focuses on enterprise users and government users. This service is called GSM Digital Trunking or Public Access Mobile Radio (PAMR). Compared with multiparty communication service, VGCS can greatly reduce the occupancy of radio channels and improve the utilization of radio channel resources.

Description VGCS simultaneously provides voice services for a group of MSs in a predefined area in half-duplex mode. The network side defines the group call number, group members and coverage area. The MS who has the permission can dial the group call number to initiate a group call. All the group members within the coverage area can be informed to join the group call. One of the group members can press and hold PTT on the mobile phone to speak to others. During this period, other members can only listen but cannot talk by pressing PTT. Other group members can speak by pressing PTT only after the talker releases PTT. After the conversation is complete, the originator terminates the VGCS call by pressing the on-hook key and then all the group members hang up. In addition, the VGCS provides dispatcher service. The dispatcher is a special subscriber of the fixed network or the mobile network defined by the network side. The dispatcher has the permission to talk at any time during a VGCS call and originates or terminates a VGCS call authorized by the network side.

Enhancement None


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Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-118601 Abis IP(Not exclusive in GBSS13.0 and later version) GBFD-118602 A over IP Dependency on other NEs The MSC, HLR, and MSs must support this feature.

1.5.2 GBFD-510303 Late Group Channel Assignment Availability This feature was introduced in GBSS8.1.

Summary After a VGCS call is established, if no group member involved in the call is in the cell within the predefined coverage area, the VGCS traffic channel is not assigned. If a group member accesses the cell during the VGCS call, then the network side assigns a traffic channel for the call.

Benefits This feature effectively saves the radio channel resources when operators promote VGCS-based services.

Description During VGCS, the voice of the talker is sent to other group members through the VGCS channel of the cell. If no group member involved in the call is in the cell within the coverage area, the VGCS channel is actually idle. With this feature, the network side sends a VGCS call notice periodically in each cell within the coverage area and the cell in which group members exist receives the response of the MS. Then, the network side assigns a VGCS channel for the cell and notifies the group members to join the VGCS call. The cells that do not respond are not assigned VGCS channels. In addition, the network side periodically detects the MSs of all the cells within the coverage area. If no group member involved in the VGCS call exists in a cell due to some reason, for example, outgoing cell handover, the network side releases the VGCS channel assigned to the cell.


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For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-118601 Abis IP(Not exclusive in GBSS13.0 and later version) GBFD-118602 A over IP Dependency on other NEs The MSC, HLR, and MSs must support this feature.

1.5.3 GBFD-510305 Single Channel Group Call Originating Availability This feature was introduced in GBSS8.1.

Summary When a VGCS/VBS call is originated, only one TCH is occupied.

Benefits When a VGCS/VBS call is originated, the originating cell needs only one TCH. This improves the utilization of frequency resources, reducing the congestion rate of TCHs during busy hours, and enhancing the QoS of network.

Description When a VGCS/VBS call is originated, the originating cell requires two TCHs by default, where one TCH is a VGCS/VBS channel and the other TCH is used for the originator to talk before a VGCS/VBS call is established. After the VGCS/VBS call is established, the network switches the originator to the VGCS/VBS channel and then releases the TCH that is assigned initially. This is called dual-channel group call originating. In the single channel group call originating mode, the BSS switches the VGCS/VBS originator from the SDCCH to the VGCS/VBS channel directly. In the entire VGCS/VBS originating phase, no more traffic channels are occupied.

Enhancement None


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This feature is mutually exclusive with the following features: GBFD-118601 Abis IP(Not exclusive in GBSS13.0 and later version) GBFD-118602 A over IP Dependency on other NEs The MSC, HLR, and MSs must support this feature.

1.5.4 GBFD-510306 Talker Identification Availability This feature was introduced in GBSS8.1.

Summary During a VGCS/VBS call, the real-time information of the current talker is displayed on each MS of the subscriber involved in the call.

Benefits Talker identification is a supplementary function of GSM Digital Trunking services, which enables the MSs involved in a VGCS call to display the information regarding the talker such as telephone number, subscriber name, and priority within the group. In this way, the group members can obtain the real-time information of the current talker and determine whether to initiate PTT preemption within the group.

Description Like the function of Calling Name Identification Presentation (CNIP), talker identification allows the information of the current talker to be displayed in real time on the MSs in the VGCS/VBS. The information includes telephone number (subscriber name in the phonebook) and priority. During a VGCS/VBS call, the network side periodically broadcasts the talk information including the MSISDN of the talker and the priorities of group members in the cell within the coverage area. After receiving the information, the MSs of other subscribers display the information of the current talker, including the MSISDN (or subscriber name in the phonebook) and priority in the group. After the talker terminates the conversation, the network side broadcasts the information periodically without the content of the talker and then other group members remove the information displayed on the MSs.

Enhancement None


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For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-118601 Abis IP(Not exclusive in GBSS13.0 and later version) GBFD-118602 A over IP Dependency on other NEs This feature complies with Huawei proprietary protocol and should be supported by the MSC/VLR, HLR, and MS.

1.5.5 GBFD-510307 Group Call EMLPP Availability This feature was introduced in GBSS8.1.

Summary Group call eMLPP ensures timely services for the VGCS/VBS/point-to-point call subscribers with high eMLPP priority by means of service/resource preemption.

Benefits This feature allows operators to provide the VGCS on different levels, improving the user satisfaction. This feature enables operators to quickly respond to requirements during emergencies, thereby guaranteeing the communications services, and fulfilling their social responsibility.

Description The eMLPP feature allows the network to use different policies such as queuing, preemption, and directed retry according to the calls with different priorities when the network resources are seized. Group call eMLPP are categorized into seven priorities: A, B, and 0-4. 

A: highest, for network internal use



B: for network internal use



0: for subscription



1: for subscription



2: for subscription



3: for subscription



4: lowest, for subscription

A and B are the highest priorities, which are used for the network maintenance. When defining subscribers, operators must define the eMLPP priorities of the subscribers and the VGCS group respectively. Group call eMLPP consists of service preemption and resource preemption. 

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During a VGCS call or point-to-point call, the MS determines whether to accept the new call (including a paging to the MS or a VGCS/VBS call) based on the priorities of these two calls. If the MS supports service preemption, the MS determines whether to join a call with high priority. 

Resource preemption If network resources (such as processing capability, signaling channels, and traffic channels) are insufficient, calls with high priorities do not release network resources. In this case, new calls with high priorities can queue or even preempt the resources seized by the calls with low priorities. For details, see the description of GBFD-115001 Enhanced Multi Level Precedence and Preemption (EMLPP).

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-118601 Abis IP(Not exclusive in GBSS13.0 and later version) GBFD-118602 A over IP Dependency on other NEs The MSC, HLR, and MSs must support this feature.

1.5.6 GBFD-510308 Fast Group Call Setup Availability This feature was introduced in GBSS8.1.

Summary Fast group call setup can shorten the time of VGCS/VBS establishment by optimizing the signaling process for establishing VGCS/VBS calls and the related data configurations.

Benefits Fast group call setup ensures the VGCS/VBS scheduling efficiency on some special occasions and meets the requirements of the VGCS/VBS subscribers.

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Description On some special occasions, the time of VGCS/VBS establishment needs to be shortened to ensure the VGCS/VBS scheduling efficiency. To shorten the time of setting up group calls, the signaling process for establishing VGCS/VBS calls and the related data configurations are optimized. Immediate assignment optimization: If the fast group call setup mode is adopted, the SABM frame contains the IMMEDIATE SETUP message when an MS originates a VGCS call. Therefore, the subsequent SETUP process can be omitted and the time of setting up VGCS calls is shortened. The BSS optimizes the channel assignment procedure by using the "Immediate TCH Assignment" and "Immediate Assignment Optimization" signaling procedures. In addition, the signaling interworking process between the BSC and the BTS is simplified, before the BSS sends the immediate assignment command to the MS. At the same time, the bandwidth of the TCH is far greater than that of the SDCCH. Hence, the MS sets up a link on the TCH quickly and easily. NCH block number optimization: Configuring a large number of blocks occupied by the NCH in a cell ensures that messages are quickly sent over the Um interface and speeds up the VGCS call establishment. Other procedure optimization: Omitting some procedures such as authentication, ciphering, or TMSI reassignment can speed up the group call establishment.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The MSC, HLR, and MSs must support this feature.

1.5.7 GBFD-510309 Group Call Reliability Enhancing Availability This feature was introduced in GBSS8.1.

Summary When the BTS is disconnected from the network, the BTS still supports the VGCS/VBS calls for specified fixed group numbers within the coverage area.

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Benefits Based on this feature, when the BTS is disconnected from the network due to accident or disaster, operators can still provide VGCS/VBS service in the area covered by the BTS, enhancing user experience and brand image of the product.

Description In addition to the system-specific reliability mechanisms such as active/standby switchover and resource pool, Huawei GBSS VGCS/VBS also provides fail soft capability for the VGCS/VBS feature to improve its reliability. After the BTS is disconnected from the network, the BTS works in fail soft mode and supports the VGCS/VBS within the coverage area. A single cell or several cells can be configured under a BTS. The BTS automatically switches to normal working mode after the transmission recovers In fail soft mode, Huawei GBSS supports the regular call initiation. The BTS initiates a VGCS call that is fixedly configured once the transmission is interrupted. Then, the subscribers can seize the uplink to talk to the subscribers in other groups within the coverage area of the BTS. The VGCS call, however, cannot be stopped so that the calls with high priority can be set up automatically once the transmission is interrupted.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-118601 Abis IP(Not exclusive in GBSS13.0 and later version) GBFD-118602 A over IP Dependency on other NEs None

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1.5.8 GBFD-510302 Public Voice Broadcast Service Availability This feature was introduced in GBSS8.1.

Summary Public voice broadcast service (VBS) adopts the simplex mode and provides point-to-multipoint voice services for a group of predefined MSs in a predefined area.

Benefits This feature enables operators to provide a new broadcast-based voice service for the subscribers and therefore increases the revenue.

Description VBS is a special type of VGCS. After the network side determines the VBS call number, group members, and coverage area, the MS who has the authority can dial the call number to initiate a VBS call. All the group members within the coverage area can be informed to join the VBS call. Only the originator can talk during a VBS call. The originator can talk without pressing PTT during the call and other members can hear the voice of the originator. After the conversation is complete, the originator terminates the VBS call by pressing the on-hook key and then all the group members hang up. In addition, the VBS provides dispatcher service. The dispatcher is a special subscriber of the fixed network or the mobile network defined by the network side. The dispatcher can originate and terminate a VBS call authorized by the network side. If the dispatcher is not the originator of the VBS call, no one can talk during the call.

Enhancement None


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1.5.9 GBFD-510304 Late Broadcast Channel Assignment Availability This feature was introduced in GBSS8.1.

Summary After a VBS call is established, if no group member involved in the call is in the cell within the predefined coverage area, the VBS traffic channel is not assigned. If a group member accesses the cell during the VBS call, then the network side assigns a VBS traffic channel for the call.

Benefits This feature effectively saves the radio channel resources when operators promote VBS-based services.

Description During a VBS call, the voice of the originator is sent to other group members through the VBS channel of the cell. If no group member involved in the call is in the cell within the coverage area, the VBS channel is actually idle. With this feature, the network side sends a VBS call notice periodically in each cell within the coverage area and the cell in which group members exist receives the response of the MS. Then, the network side assigns a VBS channel for the cell and notifies the group members to join the VBS call. VBS Channel is not assigned to the cells that do not respond. In addition, the network side periodically detects the MSs of all the cells within the coverage area during a VBS call. If no group member involved in the VBS call exists in a cell due to some reason, for example, outgoing cell handover, the network side releases the VGCS channel assigned to the cell.


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1.5.10 GBFD-510310 GSM-T Relay Availability This feature was introduced in GBSS9.0.

Summary The BSC forwards trunk calls to the trunk server through the call differentiation mechanism, so that the equipment on the radio access side supports trunk services.

Benefits Telecom operators can use the existing radio networks to provide trunk services. In other words, trunk calls are processed as a type of service to eliminate the need for an independent network. In this way, the radio network investment is decreased and the radio channel utilization is increased.

Description This feature is a solution for quickly achieving the trunk function by using the existing GSM network. The following figure shows the network topology.

When a user initiates a call, the BSC determines whether the service type is trunk call or public network point-to-point call based on the signaling. If the service type is trunk call, the BSC forwards it to the trunk server. If the service type is public network point-to-point call, the BSC forwards it to the MSC on the existing network so that the inheritance of public network services is ensured. The trunk server does not affect public network services because it is independent of the MSC on the existing network. This feature is applicable to the inventory markets of Huawei wireless domain. Only the addition of one core network and the upgrade of BSC software are required, with the advantage of fast network construction and low costs.

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Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware None Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-118601 Abis IP(Not exclusive in GBSS13.0 and later version) GBFD-118602 A over IP Dependency on other NEs The MS, MSC, and HLR must support this feature.

1.6 LCS 1.6.1 GBFD-115401 NSS-based LCS (Cell ID + TA) Availability This feature was introduced in GBSS6.1.

Summary The built-in serving mobile location center (SMLC) supports the NSS-based Cell ID+TA location service.

Benefits The location service (LCS) enables the network to provide various services for an MS based on the location of the MS. These services include weather forecasts, trip scheduling, emergency assistance, stock information, business planning, and transport conditions. In this way, the revenue of operators increases.

Description LCS is a series of services that is achieved based on locating the position of users in a certain range, such as locating an emergency call or position information of users for value-added services. LCS should reach the specified QoS, such as the required accuracy and latency. Huawei supports NSS-based Cell ID+TA location scheme of the SMLC. The location precision of this scheme is about 500 meters.

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Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The CN must support this feature.

1.6.2 GBFD-115402 BSS-based LCS (Cell ID + TA) Availability This feature was introduced in GBSS6.1.

Summary The built-in SMLC supports the BSS-based Cell ID+TA location service.

Benefits This feature can provide location services and increase the revenue of operators. Description Huawei BSS provides the BSS-based CELL+TA mobile location service. The Cell ID + TA location is used to estimate the distance between MS and BTS according to current parameter TA, improving the location precision on the basis of Cell ID. Huawei BSC integrates the SMLC. The interface between BSC and SMLC is an internal interface. The location precision of this scheme is about 500 meters.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List.

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Dependency on other GBSS features None Dependency on other NEs The CN must support this feature.

1.6.3 GBFD-115403 Simple Mode LCS (Cell ID + TA) Availability This feature was introduced in GBSS7.0.

Summary The location information of the MSs can be directly displayed on the BSC LMT.

Benefits With this feature, operators can provide location services and increase the revenue. In addition, LCS helps in disaster relief, routine network optimization, and helps handle emergency situations and customer queries

Description Huawei BSS supports the simple mode LCS on the basis of the NSS-based LCS and BSS-based LCS. The BSC transmits the location results to the BSC LMT by analyzing the location information. In addition to the location information of the traced MS, the CGI, TA, longitude and latitude of the cell, azimuth, and error can be provided.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs None

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1.6.4 GBFD-115404 Lb Interface Availability This feature was introduced in GBSS12.0.

Summary Huawei BSS supports the standard Lb interface and the interconnection between Huawei BSC and the stand-alone Serving Mobile Location Center (SMLC) to provide the location services (LCS) for the MS. The location services can be based on the CELL ID+TA mode or the AGPS mode.

Benefits 

Huawei BSS interconnects with the stand-alone SMLC to provide LCSs for the MS.



LCSs can increase the operator` s revenue. The operator can provide various LCSs for an MS based on the location of the MS. These LCSs include weather forecasts, trip scheduling, emergency assistance, stock information, business planning, and transportation information.

Description The Lb interface is a standard interface between the BSC and the SMLC. The SMLC performs functions such as selecting the location mode and calculating the position of the MS based on the measurement results provided by the MS or BSC. Huawei BSS supports the standard Lb interface, and therefore can be interconnected with the SMLC of other vendors to provide LCSs in CELL ID+TA mode or AGPS mode. The Lb interface complies with 3GPP TS 48.071, 3GPP TS 49.031, 3GPP TS 44.031, and 3GPP TS 03.71. Figure 1-1 shows the position of the SMLC in a network. Figure 1-1 Position of the SMLC in a network HLR BTS BSC BTS

MSC/ VLR

GMLC

LCS client

Lb SMLC

Huawei BSS supports message tracing on the Lb interface and provides the traffic statistical counters related to the LCSs. Huawei BSS supports flow control on the LCSs. When the stand-alone SMLC is overloaded or when the number of location requests received by the BSC exceeds the predefined threshold, the BSC rejects certain location requests to ensure the normal operation of the location system.

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Generally, Huawei BSC is interconnects with only one SMLC. When the RAN Sharing feature is enabled, Huawei BSC can be interconnected with four SMLCs of four different vendors.

Enhancement GBSS14.0 The Lb Interface feature supports LCSs in U-TDOA mode only for tests. The Huawei GBSS is used with a Type B location measurement unit (LMU) to provide high-precision Lb-based LCSs in U-TDOA mode. LCSs in U-TDOA mode are only supported by a Type B LMU. LCSs in U-TDOA mode are applied in the following scenarios: 1.

Abis TDM+Lb TDM

In this scenario, this feature must be used together with the feature GBFD-114701 Semi-Permanent Connection. 2.

Abis IP+Lb IP

The SMLC, not the BSC, manages and directly communicates with the LMU. The BSC performs only transparent transmission. The LMU and SMLC must be provided by the same vendor.


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None Dependency on BTS hardware None Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-115401 NSS-Based LCS (Cell ID + TA) or GBFD-115402 BSS-Based LCS (Cell ID + TA) or GBFD-115403 Simple Mode LCS (Cell ID + TA) Dependency on other NEs The MS must support the AGPS LCSs. The CN must support the LCSs. LCSs in U-TDOA mode are only supported by a Type B LMU.

1.7 VIP Service 1.7.1 GBFD-116001 Resource Reservation Availability This feature was introduced in GBSS6.1.

Summary Resource reservation can reserve a certain number of TCHFs for the high-priority users.

Benefits With this feature, the channel resources can be reserved for the high-priority users, which guarantees the QoS for the VIP users and improve user experience. Resource reservation provides a segmentation function for operators. With this feature, operators can provide different levels of services for users with different priorities to increase the revenue.

Description With priority-based resource reservation, the system reserves a certain number of TCHFs for high-priority users to ensure the QoS. The reservation of the channel resources in a congested cell prevents the high-priority users from eMLPP preemption and queuing. Therefore, the access rate of high-priority users speeds up and success rate increases. In addition, the half-rate service uses a coding mode different from that of the full-rate service and has a coding rate of 5.6 kbit/s. Therefore, after the half-rate service is enabled, the voice quality of the half-rate service deteriorates. The MSs of some low-priority users do not support the half-rate feature. Consequently, in the cells where the half-rate feature is enabled,

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these MSs only occupy the TCHFs and have a high voice quality. However, the MSs of some high-priority users which support the half-rate function. After the half-rate function is enabled in a cell, the TCHHs are preferably assigned to the MSs. Therefore, the high-priority users receive a low voice quality. The resource reservation feature reserves TCHFs for these high-priority users to ensure the QoS. The TCHFs can be reserved for the high-priority users as required. In each channel assignment, if the users with the priority equal to or higher than the defined high priority and the reserved channels is sufficient, the TCHFs are directly assigned to the users; if all the reserved channels are assigned, the preemption flow is performed according to the eMLPP rule. If the priority of the user is lower than the defined high priority, the system checks whether the total number of occupied channels and idle channels is greater than the number of reserved channels. If the total number of occupied channels and idle channels is greater than the number of reserved channels, the system initiates the normal call flow; otherwise, the queuing and preemption flow are performed according to the queuing and eMLPP rule.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature can be used together with GBFD-5001 Enhanced Multi Level Precedence and Preemption (EMLPP), which can effectively improve user benefits and satisfaction. Dependency on other NEs None

1.7.2 GBFD-115001 Enhanced Multi Level Precedence and Preemption (EMLPP) Availability This feature was introduced in GBSS6.1.

Summary The enhanced multi-level precedence and preemption service (eMLPP) is a supplementary service that is used to ensure a normal conversation of the subscriber with higher priority by preemption, queuing, directed retry, and forced handover.

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Benefits This feature ensures the QoS of the VIP subscribers and improves their experience. This feature allows operators to classify subscribers into different categories. Therefore, operators can provide different levels of services for users with different priorities to increase revenue.

Description The eMLPP is a supplementary service offered by the GSM system. The eMLPP service allows a subscriber to initiate calls with different priorities. The network side employs different channel assignment strategies for the subscribers according to the priorities. If the network is congested, the call with higher priority is served preferably. The eMLPP service requires the support from MS to ensure that the subscriber can initiate calls of different priorities under different situations. A normal conversation of the subscribers with higher priority is ensured by preemption, queuing, directed retry, and forced handover. With this service, the high-priority subscribers have an advantage in call establishment rate and completion rate compared with the lower-priority subscribers according to different priority configurations in a network. The eMLPP service provides the following two mechanisms: 

Preemption The MSC determines whether preemption is allowed. Then, the MSC sends an assignment request or handover request message to the BSC to notify the BSC whether preemption is allowed. If the MSC allows for performing the preemption and eMLPP is enabled, the BSC forcibly switches the call with lowest priority to a neighboring cell when the TCHs are congested to release the resource for the call with high priority. However, if eMLPP is not enabled, the BSC releases the resource of a low-priority user directly to ensure that the call with high priority is served normally.



Queuing The MSC determines whether queuing is allowed. Then, the MSC sends an assignment request or handover request message to the BSC to notify the BSC whether queuing is allowed. When the cell has no idle TCH and the MSC allows queuing, the BSC puts the TCH request into the queue. Then, when idle TCHs are available, the TCH is assigned to the waiting call in the queue. If the directed retry is allowed, the BSC performs directed retry before the queue timer expires.

Enhancement GBSS12.0: eMLPP Enhancement: The preemption and queuing functions are enhanced, and therefore the utilization of radio resources is optimized. When an outgoing BSC better cell handover occurs on a high-priority MS, the BSC notifies the MSC and the target BSC that they should neither preempt the radio resources that are allocated to other MSs for the high-priority MS nor queue the high-priority MS. On receiving the incoming BSC handover request from a high-priority MS, the target BSC checks the type of the handover. If the handover is a better cell handover, the target BSC neither preempts the radio resources that are allocated to other MSs for the high-priority MS nor queues the high-priority MS. In this way, the high-priority MS will never preempt the radio resources

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that are allocated to a low-priority MS when the serving cell can provide service for the high-priority MS. When an intra-BSC handover (any handover other than better cell handover) occurs on a high-priority MS, the BSC can preempt the radio resources that are allocated to a low-priority MS for the high-priority MS. The high-priority MS is queued if the radio resources that are allocated to a low-priority MS cannot be preempted. In this manner, the BSC ensures the speech quality of the high-priority MS by preempting the radio resources that are allocated to a low-priority MS when the serving cell cannot provide good service for the high-priority MS.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The CN and HLR must support this feature.

1.7.3 GBFD-115002 Flow Control Based on Cell Priority Availability This feature was introduced in GBSS9.0.

Summary With this feature, when service congestion occurs in the GBSC, the flow control is started. The calls in the VIP cells are preferentially processed. Therefore, the normal operation of the GBSC and the call setup success rate of the VIP users are ensured.

Benefits The operators can apply this feature in areas with a lot of VIP users, such as central business districts (CBDs), saloon bars, and airports. In this way, the calls made by the VIP users are not affected even if the BSC system is overloaded because of burst traffic, improving the service quality.

Description In the GBSC, the system is overloaded if a large number of MS-originated calls are initiated or the core network initiates a large number of pagings in a short period. To prevent that the system is overloaded and ensure the normal operation of the system, the GBSC performs the flow control and discards some access requests and paging messages. The operators can divide the cells under the BSC into VIP cells and non-VIP cells as required. When the GBSC system is overloaded, the call requests initiated in the VIP cells are preferentially handled. The call requests initiated by the users in the non-VIP cells are

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processed according to the common flow control algorithm (GBFD-111705 GSM Flow Control).

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other functions of the GBSS The two features are recommended working together: GBFD-115002 Flow Control Based on Cell Priority GBFD-115003 Flow control based on User priority The former one controls uplink flow, and the latter one controls downlink flow. Dependency on other NEs None

1.7.4 GBFD-115003 Flow control based on User priority Availability This feature was introduced in GBSS13.0.

Summary Based on the user priority information in eMLPP, the GBSC performs different flow control policies for users in the case of network congestion. This ensures service availability for high-priority users.

Benefits Service availability is ensured for high-priority users in the case of traffic volume bursts.

Description When congestion occurs, the BSC determines whether a user is a VIP user or not according to the eMLPP priority of the user. The BSC preferentially processes the paging messages of VIP users. It processes the paging messages of non-VIP users according to the flow control algorithm. To protect the service of high-priority users from being affected by flow control, the GBSC uses the priority information in eMLPP to classify the signaling priority in flow control. The

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signaling of high-priority users will not be affected by flow control, whereas the signaling of low-priority users may be discarded due to flow control. Flow control will be used in channel assignment, handover, and paging procedures.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other functions of the GBSS This feature depends on the following features: GBFD-115001 Enhanced Multi Level Precedence and Preemption (EMLPP) The two features are recommended working together: GBFD-115002 Flow Control Based on Cell Priority GBFD-115003 Flow control based on User priority The former one controls uplink flow, and the latter one controls downlink flow. Dependency on other NEs None

1.7.5 GBFD-119907 PS Service in Priority Availability This feature was introduced in GBSS12.0.

Summary This feature enables telecom operators to provide subscribers with differentiated services. Subscribers are classified into three priority levels: gold, silver, and copper. The bandwidth and delay requirements of high-priority subscribers are preferentially guaranteed.

Benefits Based on subscriber priorities, telecom operators provide differentiated services and charge subscribers based on flexible policies. For example, a telecom operator charges a gold subscriber based on traffic whereas charges a silver or copper subscriber at a flat rate.

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Description Subscriber priorities are represented by parameters, which are set depending on the traffic class, ARP, and THP. If the priority of a subscriber is high, the scheduling priority is also high. As a result, the subscriber can use services with high bandwidth and low service delay. Interactive, background, and BE services support differentiated PS services.

Enhancement None

Dependency Dependency on BSC hardware A built-in PCU is required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The MS and SGSN must support this feature.

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2

Packet Service

2.1 PS Prime Service 2.1.1 GBFD-114101 GPRS Availability This feature was introduced in GBSS6.1.

Summary The General Packet Radio Service (GPRS) is a type of end-to-end packet switched service based on the GSM technology.

Benefits By providing the data service to the subscriber, the GPRS increases the operators' revenue and the proportion of the PS services in the mobile services.

Description Huawei GPRS is implemented by adding GPRS support nodes (GSNs) and packet control unit (PCU) on the GSM system and upgrading the software. There are two PCU modes: built-in PCU and external PCU. The GPRS provides quick access of PS services for the mobile subscribers. Huawei external PCU is connected to the BSC through the Pb interface. Huawei GPRS has an open system architecture, which facilitates smooth capacity expansion. The standard interfaces ensure the device compatibility and support the QoS features and the dynamic allocation of radio resources. In addition, the flexible networking and configuration save a large amount of CAPEX for the operator in the initial phase of the GPRS service operation. GPRS provides abundant packet services, for example, mobile Internet access, e-Commerce (e-Bank and e-Currency), cluster management, remote control/remote measurement, booking system (hotels, theaters, and airplanes), and group services (stock information publication). Huawei GPRS implements mainly three functions: managing radio links and resources, controlling MS access, and providing routing functions for packet data transmission. The radio link management includes establishment, maintenance, and release of radio links. The radio resource management includes encoding/decoding, configuration, and multiplexing of

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the radio packet channel and conversion between the CS service channels and the PS service channels. In addition, by controlling the access of the MSs, the GPRS solves the problem of channel contention and assigns channels for MSs according to the requested QoS. The GPRS system also provides routes to transmit the packet data to the SGSN and receives the downlink data from the SGSN. Huawei GPRS uses 16 kbit/s links on the G-Abis interface. When the CS-3 and CS-4 coding schemes are used, the rate of one PDCH is 15.6 kbit/s and 21.5 kbit/s respectively. Therefore, when the radio channel is mapped onto the terrestrial channel, one PDCH in CS-3 and CS-4 coding schemes should be mapped onto two 16 kbit/s links. Using the dynamic additional sub-timeslot technology, Huawei GPRS solves the transmission problem over the G-Abis interface when the CS-3 and CS-4 coding schemes are used. The dynamic additional sub-timeslot technology assigns a main 16 kbit/s sub-timeslot statically and an additional 16 kbit/s sub-timeslot dynamically on the G-Abis interface for each PDCH using CS-3 or CS-4. The dynamic additional sub-timeslot technology has the following features: Any idle 16 kbit/s sub-timeslot on the G-Abis interface can be used as an additional 16 kbit/s sub-timeslot; the additional sub-timeslot can be dynamically attached to different main timeslots within the same site and therefore the usage of additional sub-timeslot is increased based on the statistical multiplexing rule; the additional sub-timeslot does not need to be the neighbor of the main timeslot; the data packet is assembled and fragmented through software, which avoids the upgrade of hardware due to different product specifications; dynamical assignment of the TCH on the Abis interface can reduce the cost of the transmission on the Abis interface and therefore reduce the O&M cost of the equipment.

Enhancement None

Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The MS and the CN must support this feature.

2.1.2 GBFD-510001 Network Operation Mode I Availability This feature was introduced in GBSS8.0.

Summary The Network Operation Mode I feature together with the Gs interface between the MSC/VLR and the SGSN support the paging coordination function.

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The Network Operation Mode I together with the Gs interface support paging coordination and the CS paging when the MS is in packet transfer state.



The Network Operation Mode I feature greatly reduces the signaling load between the MS and the network, saving and optimizing the radio resources.

Description The GSM specifications define three network operation modes according to the paging mode adopted for CS and PS services: Network Operation Mode I, Network Operation Mode II, and Network Operation Mode III. This feature refers to the Network Operation Mode I. With this feature, the network sends the CS paging message to the MS on the packet channels. That is, the network side sends the CS paging message to the MS on the PCCCH, CCCH, or PACCH. The MS monitors only one paging channel. 

If the PCCCH is configured and the MS is in idle state, both the CS paging message and the PS paging message are sent on the PCCCH.



If the CCCH but not the PCCCH is configured in the cell and the MS is in idle state, both the CS paging message and the PS paging message are sent on the CCCH.



If the MS is in transfer state, the CS paging message is sent on the PACCH.

The Network Operation Mode I requires the configuration of the Gs interface between the MSC/VLR and the SGSN because the CS paging message must be transmitted through the SGSN. For the MS, it listens to only one type of channel to receive the CS paging message. The Network Operation Mode I feature greatly reduces the signaling load between the MS and the network, saving and optimizing the radio resources. Using the Network Operation Mode I, the MS receives the CS paging message on the PACCH when processing the PS services. Then, the MS stops the PS services and initiates the CS services.

Enhancement None

Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The Gs interface should be supported by the CN if the paging coordination is supported.

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2.1.3 GBFD-118901 CS-3/CS-4 Availability This feature was introduced in GBSS8.0.

Summary The CS-3/CS-4 feature fully uses the capability that the GPRS MS already has, increasing the throughput. The BSC adjusts the coding scheme to a higher level in the area with low error bit rate according to the transmission quality of the MS.


Increases the GPRS service rate, improves the packet service performance in areas where the EGPRS is not supported, and improves the satisfaction of the subscribers in the entire GPRS network.



Fully uses the capability that the GPRS MS already has, chooses more suitable coding scheme (from CS-1 to CS-4) according to reasonable GPRS link control algorithm, improving the spectrum efficiency.

Description According to GSM specifications, the GPRS can use four coding schemes, namely, CS-1, CS-2, CS-3, and CS-4. Although the CS-1 and CS-2 coding schemes ensure 100% and 90% cell coverage respectively and meet the co-channel interference requirement C/I = 19 dB, they only have a data rate of 9.05 kbit/s and 13.4 kbit/s (containing the head of the RLC block) respectively. The reason is that the half-rate and 1/3 rate bits in the RLC blocks of the CS-1 and CS-2 schemes are used for forward error correction (FEC). This reduces the requirement for C/I and the transmission rate. To increase the transmission rate, Huawei provides the CS-3 and CS-4 schemes. The CS-3 and CS-4 schemes provide the transmission rate of 15.6 kbit/s and 21.4 kbit/s (containing the head of the RLC block) respectively. In addition, the CS-3 and CS-4 schemes have higher requirements for C/I. During the data transmission, the BSC dynamically adjusts the channel encoding or decoding scheme according to the retransmission rate of the RLC blocks transmitted on the uplink or downlink TBF. This improves the transmission rate on the basis of guaranteed transmission quality and maximizes the use of radio resources. This feature supports the dynamic conversion among CS-1, CS-2, CS-3, and CS-4.

Enhancement None

Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required.

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Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-114101 GPRS Dependency on other NEs None

2.1.4 GBFD-114201 EGPRS Availability This feature was introduced in GBSS8.0.

Summary The enhanced GPRS (EGPRS) is an enhancement of the GPRS system. EGPRS uses the 8PSK modulation mode on the RF layer so that the rate of a single channel is increased. The maximum rate of a single channel is 59.2 kbit/s. EGPRS adopts new coding schemes MCS-1 to MCS-9. EGPRS improves the algorithm for controlling the link quality by modifying of the RLC/MAC protocol at the link layer.


Provides high-speed PS services, increases packet capacity, and reduces the delay of PS services and the congestion rate, improving the service quality and enhancing the user experience.



Attracts more subscribers of PS services and therefore increases the operators' revenue by providing more multimedia services.

Description Compared with GSM, EDGE supports a higher data transmission rate. EDGE provides a set of enhanced standards for the GSM interfaces and enables the GSM network to carry 3G services. EDGE consists of EGPRS and ECSD. EGPRS is an enhancement of the GPRS system. It improves the rate of data channels. EGPRS improves the data transmission capability of a single timeslot by adding the 8PSK modulation scheme on the Um interface and improves the data transmission capability of a single user through multislot binding. Huawei EGPRS has the following features: Huawei EGPRS supports the coding schemes MCS-1 to MCS-9 in the uplink and downlink, as listed in the following table.

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2x6

8

Data rate

HCS

2x12

(kbit/s)

Tail Payload

MCS-6

BCS

MCS-7

Family

0.92

Raw Data within one Radio Block

MCS-8

8PSK

RLC Blocks per Radio Block (20 ms)

0.36

Modulation

1.0

Mode

Header Code Rate

Code Rate

Scheme MCS-9

2 Packet Service

2

2x592

A

0.36

2

2x544

A

54.4

0.76

0.36

2

2x448

B

44.8

0.49

1/3

1

592

A

544+48 MCS-5

0.37

1/3

MCS-4

1.0

0.53

MCS-3

0.85

0.53

GMSK

12

6

59.2

29.6 27.2

1

448

B

22.4

1

352

C

17.6

1

296

A

14.8

272+24

13.6

MCS-2

0.66

0.53

1

224

B

11.2

MCS-1

0.53

0.53

1

176

C

8.8

2. Support for the incremental redundancy (IR) mechanism in the uplink and downlink EGPRS adopts two modes for controlling the link quality: link adaptation (LA) and IR. Compared with GPRS that uses only the LA mode, EGPRS uses both the LA mode and the IR mode. The working principle of the IR mechanism is as follows: Generally, the transmitter uses the coding scheme with a high rate for data transmission; however, the coding scheme with a high rate always has a weak protection capability. If the data is received incorrectly, the transmitter retransmits additional coding information. The receiver combines the new information with the historical information and then performs decoding. This procedure is repeated until the decoding is successful. 3. Support for dynamic adjustment of EGPRS coding schemes in the uplink and downlink The dynamic adjustment of EGPRS coding schemes is similar to the dynamic adjustment of GPRS coding schemes. The GBSS sends the system information to the MS. The MS calculates the bit error probability (BEP) in the downlink and reports the result to the GBSS through the measurement report. The GBSS then adjusts the EGPRS coding schemes in the uplink and downlink based on the downlink BEP. 4. Dynamic additional sub-timeslot technology The dynamic additional sub-timeslot technology solves the problem of transmission over the G-Abis interface using MCS-3 to MCS-9. The dynamic additional sub-timeslot technology statically assigns one main 16 kbit/s sub-timeslot and dynamically assigns one to three additional 16 kbit/s sub-timeslots on the G-Abis interface for each PDCH using MCS-3 to MCS9. Using the dynamic additional sub-timeslot technology, the EGPRS BSS does not need to upgrade the hardware of the BTS, BSC, and PCU for supporting MCS-3 to MCS-9. In

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addition, EGPRS maximizes the multiplexing mode over the G-Abis interface, saving the investment on the transmission devices over the G-Abis interface. The strategy for allocating the 16 kbit/s sub-timeslots for different EGPRS services is listed in the following table. Coding Scheme

Number of 16 kbit/s Timeslots Allocated over the Abis Interface

MCS-1 to MCS-2

1

MCS-3 to MCS-6

2

MCS-7

3

MCS-8 to MCS-9

4

Enhancement None

Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The SGSN, GGSN, and MS must support this feature.

2.1.5 GBFD-113101 PDCH Dynamic Adjustment Availability This feature was introduced in GBSS6.1.

Summary With this feature, fixed channels do not need to be configured for the PS services, the TCH and the PDCH can be automatically converted as required.

Benefits This feature provides the following benefits:

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

Reduces the impact of GPRS services on the GSM speech services, decreases the maintenance and configuration workload, and increases channel usage and network capacity.



Improves the performance of the PS services and increases the operators' revenue.



Packet channel types

Description The PDCH is classified into static PDCH and dynamic PDCH based on the bearer services (CS services or PS services). The static PDCH is used for the PS services only. The dynamic PDCH is a TCH during the initialization process. In the case of packet access, the TCH and the PDCH can be dynamically converted. 

PDCH dynamic adjustment The static PDCH is used for the PS services only. The dynamic PDCH is a TCH during the initialization process. When the packet resources are insufficient, the PCU requests dynamic PDCHs from the BSC for the PS services. When the circuit resources are insufficient, the BSC requests dynamic PDCHs that are used as TCHs from the PCU. In this manner, the channel resources are flexibly used as required. Therefore, the usage of resources is increased, and the complexity of PDCH configuration and the workload of maintenance and configuration are reduced. In addition, the impact of unreasonable PDCH configuration on the service performance is reduced.

Enhancement GBSS7.0 PDCH Preemption Priority: In the latter period of the GSM network development, the requirements for the PS services are preferentially met because of the significant increase in the data service demand. Huawei PCU equipment supports three types of PDCH preemption priorities: all dynamic channels preemptable, packet control channels unpreemptable, and all dynamic channels carrying services unpreemptable. This application enhancement optimizes the performance of the PS services by limiting channel preemption of the CS services. The operators can implement different packet allocation strategies by configuring preemption priority. All dynamic channels preemptable: The CS services can preempt all dynamic channels. Packet control channels unpreemptable: The CS services can preempt all the other dynamic channels except the packet control channels. All dynamic channels carrying services unpreemptable: The CS services cannot preempt all the dynamic channels carrying services. GBSS8.0 Overall Dynamic PDCH Availability: Except for static PDCHs, all the other channels can be converted in real time based on the situation of the PS services and the CS services. If required, TCHs can be converted to PDCHs for the PS services. With this application enhancement, more PDCHs can be converted when the CS services are not busy. This can alleviate the decrease in the transmission rate due to PDCH multiplexing. This flexible mechanism can maximize the channel usage and optimize the distribution of PDCHs and TCHs. In addition, the network planning is simple and therefore you can expand the capacity if required.

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Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-114101 GPRS GBFD-114201 EGPRS Dependency on other NEs None

2.1.6 GBFD-510002 Gb Over FR Availability This feature was introduced in GBSS8.0.

Summary As a traditional networking mode, the Gb over FR feature enables the operator to deploy the network in frame relay (FR) transmission mode between the BSC and the SGSN.


This feature is compatible with the CN equipment in the existing network.



This feature enables the operator to fully utilize the existing network in FR transmission mode.

Description This feature complies with the 3GPP protocols. The Gb interface provides connections between the BSS and the SGSN to send the information related to cell management and handovers in routing areas and transmit the data between the MS and the SGSN. Traditionally, the Gb interface uses the FR transmission mode to provide the logical link connection. Data is transferred through the network service virtual connection (NS-VC). The NS-VC is the permanent virtual channel (PVC) in FR. Huawei GBSS supports the FR networking over the Gb interface in the E1/T1 direct transmission mode or the FR transmission mode and supports configuration of multiple PVCs between the BSS and the SGSN. In addition, Huawei BSS manages these PVCs and supports load sharing among them. The BSC that supports Gb over FR requires no hardware upgrade. Only software upgrade is required to deploy the SGSN pool.

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The BSC supports the FR transmission mode and the IP transmission mode for the communication between the BSC and the SGSN. These two modes can work simultaneously.

Enhancement None

Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs None

2.1.7 GBFD-119201 11-Bit EGPRS Access Availability This feature was introduced in GBSS8.0.

Summary The Packet Channel Request message is an 8- or 11-bit access burst. This feature supports the 11-bit EGPRS access. The 11-bit access burst contains the multislot capability of an MS and therefore enables rapid allocation of more channels. The EGPRS MS supports one-phase 11-bit access. This shortens the access delay.

Benefits This feature shortens the access delay and increases the access rate of the EGPRS MS, increasing the subscriber satisfaction.

Description With this feature, the EGPRS MS can send the 11-bit channel access signaling request. In this manner, the system implements only one-phase access. That is, the system can immediately assign signaling for the MS to establish the uplink TBF and then transmit data. Before this feature is used, two-phase access is required. Moreover, this feature shortens the time for TBF establishment and improves the performance of small-sized data transmission (such as the TCP handshake).

Enhancement None

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Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-114201 EGPRS Dependency on other NEs The MS must support this feature.

2.1.8 GBFD-119203 Extended Uplink TBF Availability This feature was introduced in GBSS8.0.

Summary This feature ensures that the TBF is not released when no data is transmitted. In this manner, the TBF does not need to be re-established after the data is transmitted again. Therefore, frequent TBF establishment and releases are avoided.

Benefits This feature reduces the cost for establishing the uplink TBF, shortens the data transmission time in the uplink, and increases the uplink rate.

Description After the uplink data is sent, the common uplink TBF is released immediately whereas the extended uplink TBF enters the inactive period. If there is new data to be transmitted, the TBF in inactive period enters the active period for data transmission. If the inactive period timer expires and there is no data to be transmitted, the TBF is released. The inactive period timer is an adjustable parameter pertaining to network optimization. With this feature, the throughput rate of the services with unstable data flow such as webpage browsing and email sending is improved.

Enhancement None


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Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-114101 GPRS GBFD-114201 EGPRS Dependency on other NEs The MS must support this feature.

2.1.9 GBFD-119204 Dynamically Adjusting the Uplink MCS Coding Availability This feature was introduced in GBSS8.0.

Summary This feature enables the BSS to support coding schemes MCS-1 to MCS-9 and dynamically adjust the coding scheme based on the radio quality.

Benefits This feature increases the uplink rate of the EGPRS users, enhances the user experience, and improves the network quality.

Description The requirements for the radio transmission quality vary with the transmission rate of the coding schemes. The higher the transmission rate, the higher the requirements for the radio transmission quality. During the data transmission process, the BSC dynamically adjusts the coding scheme based on the radio quality to maximize the radio resource usage and the transmission rate with guaranteed transmission quality. Currently, the BSS supports nine coding schemes MSC-1 to MCS-9. The aim of this feature is to dynamically adjust the uplink rate of the EGPRS user based on the network status. With this feature, the BSC dynamically adjusts the coding scheme adopted by the PDCH based on the uplink measurement report from the BTS. In this manner, the PDCH can quickly adapt to the changes in the radio condition and therefore the uplink throughput is increased.

Enhancement None


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Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-114201 EGPRS Dependency on other NEs None

2.1.10 GBFD-119205 Dynamically Adjusting the RRBP Frequency Availability This feature was introduced in GBSS8.0.

Summary With this feature, the relative reserved block period (RRBP) frequency is dynamically adjusted according to the status of the uplink TBF and the downlink TBF. The data blocks with the RRBP flag in the downlink are sent at different intervals.


Optimizes the uplink access rate of PS services, improving the performance of the TCP services such as FTP downloading by increasing the rate of sending the TCP ACK message. As a result, the user experience is enhanced.



Reduces unnecessary data flow in the uplink and the impact on other users on the same PDCH.

Description This feature optimizes the RRBP frequency based on two factors: uplink TBF status and the phase of delayed downlink TBF release. 

Uplink TBF status and RRBP frequency During the downlink transmission process, the BSC periodically sends data blocks with RRBP flag to reserve uplink resources for the MS to respond with the PACKET DOWNLINK ACK/NACK message to report the receiving status of the downlink data. When the MS needs to send data in the uplink but the uplink TBF does not exist, the MS can carry the channel request information in the PACKET DOWNLINK ACK/NACK message to initiate the access. Therefore, if the frequency of sending the data blocks with RRBP flag is increased at this time, the access rate of the MS can be increased. On the other hand, the PACKET DOWNLINK ACK/NACK message seizes the uplink bandwidth. Therefore, when the uplink TBF already exists, the uplink expenditure is reduced and the uplink data bandwidth is increased if the frequency of sending the data blocks with RRBP flag is reduced.



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Phase of delayed downlink TBF release and RRBP frequency Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd

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The MS generally has a demand for sending uplink data in the earlier period of the delayed downlink TBF release after the data transmission in the downlink is complete. At this time, the BSS system uses a high frequency for sending the data blocks with the RRBP flag. In the latter period of the delayed downlink TBF release, there is less data to be sent in the uplink. At this time, the BSS system uses a low frequency for sending the data blocks with the RRBP flag. This feature dynamically adjusts the frequency for sending the data blocks with the RRBP flag based on the uplink TBF status and the phase of delayed downlink TBF release. When the uplink TBF exists and the delayed TBF release is in the latter period, a low frequency can be used to save the uplink bandwidth. When the uplink TBF does not exist and the delayed TBF release is in the earlier period, a high frequency can be used to increase the uplink access rate of the MS.

Enhancement None

Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other NEs None Dependency on other GBSS features This feature depends on the following features: GBFD-114101 GPRS GBFD-114201 EGPRS Dependency on other NEs None

2.1.11 GBFD-119302 Packet Channel Dispatching Availability This feature was introduced in GBSS8.0.

Summary The GPRS system uses only the GMSK modulation scheme whereas the EGPRS system uses the GMSK and 8PSK modulation schemes. When EGPRS downlink services and GPRS uplink services use the same packet channel, the EGPRS downlink data blocks with the USF should be used to schedule the GPRS uplink services. In this case, the EGPRS downlink data blocks can use only the GMSK modulation scheme. This greatly affects the downlink throughput of the EGPRS MS. With this feature, the operator can separate the EGPRS

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services from the GPRS services, effectively increasing the downlink throughput of the EGPRS MS.

Benefits This feature reduces the probability that the EGPRS services and the GPRS services use the same channel, increasing the EGPRS service rate, improving the entire network performance, and enhancing the user experience.

Description 

Types of Preferred Channels for Packet Services There are five types of preferred channels: EGPRS dedicated channel, EGPRS preferred channel, common EGPRS channel, GPRS channel, and non-GPRS channel. EGPRS dedicated channels serve only EGPRS MSs. EGPRS preferred channels serve EGPRS MSs in preference to GPRS MSs but can be used by GPRS MSs when the channels are not occupied by EGPRS MSs. When an EGPRS MS requests an EGPRS preferred channel, the GPRS MSs that occupy the EGPRS preferred channels should be transferred to other channels. EGPRS MSs and GPRS MSs cannot use the same EGPRS preferred channel. Common EGPRS channels serve either GPRS MSs or EGPRS MSs, whichever occupies the channel first. GPRS channels serve GPRS MSs. If a cell is not configured with EGPRS channels, EGPRS MSs in the cell use these channels to process GPRS services. Non-GPRS channels are channels that are not used for the PS services.



Channel Allocation Principles When configuring the channel type on the TRX, you can select the channel type from the GPRS preferred channel types. When the BSS allocates PDCHs, the preferred channel type varies with the specific packet services. For GPRS services, the channels are preferentially assigned in the following order: GPRS channels, common EGPRS channels, and EGPRS preferred channels. For EGPRS services, the channels are preferentially assigned in the following order: EGPRS dedicated channels, EGPRS preferred channels, and common EGPRS channels. Multiplexing of common EGPRS channels may occur when the GPRS MS uses the uplink channel and the EGPRS MS uses the downlink channel. To avoid this, you can set Allow E Down G Up Switch to Close. If you want to avoid this situation do not configure common EGPRS channels. Channels should be used based on the type of the preferred channel. For example, if the channels on the TRX that supports EGPRS are configured as GPRS channels, these channels can be used for only GPRS services. EGPRS dedicated channels can be configured only as static channels whereas the other three preferred channels can be configured as static or dynamic channels.

Enhancement None

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Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-114201 EGPRS Dependency on other NEs None

2.1.12 GBFD-119303 Load Sharing Availability This feature was introduced in GBSS8.0.

Summary Based on the traffic load on the PDCHs, load sharing applies to the dynamic adjustment of the MS distribution on the PDCHs to improve the channel utilization and single-user PS service rate.

Benefits This feature helps improve the channel utilization and PS service rate.

Description The strategy for load sharing includes the following three parts: When an MS accesses the network, the system preferentially assigns a TRX with a light load to the MS to adjust the load distribution between TRXs. When the MS provides PS services, the system assigns the MS a PDCH or PDCHs with a light load. The occupancy of channel resources varies during the transmission. For example, if the MS releases channel resources when the service ends, some TRXs or PDCHs are idle. If the MS accessing the network is not shifted from the channel with heavy load to the channel with a light load, the channel resources are wasted. According to the load on the PDCHs, the BSS shifts the MS carried on the PDCH with a heavy load to the one with a light load. Therefore, load sharing is implemented and the single-user rate increases. When the channel is released, the system adjusts the load distribution between channels according to the traffic load on each channel to ensure load balance on the PDCHs, optimally utilizing channel resources.

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Enhancement GBSS8.1 Load sharing during the release of radio resources: This function enhances the load balance between TRXs when radio resources are released. Therefore, the resources on all the TRXs are reassigned in the cell. That is, the MSs carried on the TRXs with a heavy load are assigned to those with a light load, and then the MSs carried on the PDCHs with a heavy load are assigned to those with a light load so that the load balance between all the TRXs in the cell is realized and the channel resources are optimally utilized. For example, an MS transmits data for a long time. During the data transmission, if radio resources are released by other MSs, the BSC determines whether the TRX used by the MSs that release radio resources are idle. If the TRX is idle, the MS performing long-time data transmission is reassigned with the channels on the idle TRX. Therefore, the throughput of the MS is increased. When the traffic load of the GPRS channels decreases, some GPRS MSs are shifted from the EGPRS channel to the GPRS channels to increase the channel utilization and minimize the impact on the EGPRS services.


2.1.13 GBFD-119501 Adaptive Adjustment of Uplink and Downlink Channels Availability This feature was introduced in GBSS8.0.

Summary The uplink and downlink channel adaptive adjustment implements dynamic assignment of the number of uplink and downlink channels for the MSs based on the uplink and downlink service data flow.

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Benefits In the case of the services that are processed on both the uplink and downlink such as ping large packets and Push to Talk over Cellular (PoC), this feature helps to reduce the system transmission delay. In the case of the downlink-preferred services such as FTP download, this feature helps improve the downlink data throughput. In the case of the uplink-preferred services such as e-mail sending, this feature, used together with extended dynamic allocation (EDA), helps improve the uplink data throughput.

Description The BSS measures the data throughput of uplink and downlink of each temporary block flow (TBF) regularly to determine the current service type of the TBF. If the downlink-preferred service is performed, the BSS assigns as many downlink timeslots as possible to the MS. For an MS with multislot class of 12, the BSS uses the 4+1 DL/UL timeslot configuration preferentially. If the uplink-preferred service is performed, the BSS assigns as many uplink timeslots as possible to the MS. For an MS with multislot class of 12, the BSS uses the 1+4 DL/UL timeslot configuration preferentially used together with EDA. If the service processed on both the uplink and downlink is performed, the BSS tries to assign the timeslots of uplink and downlink asymmetrically to the MS. For an MS with multislot class of 12, the BSS uses the 3+2 DL/UL timeslot configuration preferentially.

Enhancement None


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2.2 PS Service Enhancement 2.2.1 GBFD-119901 Streaming QoS(GBR) Availability This feature was introduced in GBSS8.0.

Summary For the streaming class services, after the QoS mechanism is introduced, the BSC allocates radio resources according to the guaranteed bit rate (GBR) of the QoS to ensure the data transmission rate. When the radio resources are insufficient, the subscribers with high priority can preempt the radio resources of the subscribers with low priority.


Ensures sufficient and stable bandwidth for the streaming services.



Ensures preferentially the bandwidth requirement and service experience of the subscribers with high priority when radio resources are insufficient.



Helps the operator to take flexible charging policies.

Description This feature supports the packet flow management (PFM) procedure, which manages packet flow context (PFC). The PFM process includes the establishment, modification, and deletion of the PFC. In addition, the BSC obtains or modifies the attributes of QoS through the PEM procedure. This feature is enabled to support streaming and push to talk over cellular (PoC) services. If the MS supports GBR, the resources are allocated according to the GBR of the QoS. If the MS does not support GBR, the resources are allocated according to the BEST EFFORT. The BSC dynamically allocates Um interface resources to the MS based on the radio environment so that the bandwidth of the MS is permanently greater than or equal to the GBR. When the radio resources on the Um interface are insufficient, the GBR is reduced. When the radio resources on the Um interface are sufficient, the reduced GBR is restored. When the BSC needs to reduce or restore the GBR, it requests the SGSN to modify the GBRs through the PFM procedure.

Enhancement GBSS8.1 Streaming class service resource preemption: If the BSC cannot offer sufficient transmission resources for the high-priority subscribers of the streaming class service, the transmission resources of the low-priority subscribers of the streaming class service will be preempted. If the radio resources are still insufficient after preemption, the GBR is reduced. If the radio resources are sufficient, the reduced GBR is restored. This feature ensures that the high-priority subscribers of the streaming services preferably use the radio resources, reducing the possibility that the packet service access fails due to insufficient radio resources on the Um interface and improving the user experience.

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Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features PS-related features are dependent on the following features (the individuals are not listed here): GBFD-114101 GPRS GBFD-114201 EGPRS Dependency on other NEs The MS and SGSN must support this feature.

2.2.2 GBFD-119902 QoS ARP&THP Availability This feature was introduced in GBSS8.0.

Summary After the QoS mechanism is introduced, the BSC allocates radio resources to the users according to the allocation/retention priority (ARP) and traffic handle priority (THP) of the QoS. The higher-priority users enjoy more radio resources and higher radio bandwidth. To be compatible with R97/R98 QoS, this feature supports the mapping between R97/98 QoS and R99 QoS.

Benefits With this feature, the operator allocates the radio resources according to different service types and user priorities. As a result, the user with higher priority can seize more bandwidth and enjoy higher data rate and better quality of service. This feature has the following benefits: 

High-priority users can enjoy more bandwidth whereas low-priority users are subject to bandwidth constraint.



The bandwidth allocation mechanism is more flexible because the operator can allocate the radio resources according to different service types and user priorities.



The operator can formulate flexible charging policies.

Description The BSC allocates the radio resources to the MS according the ARP and THP of the QoS. The higher-priority users enjoy more radio resources and higher radio bandwidth. Interactive services: The BSS allocates the radio resources according to the ARP and THP of the QoS. If the ARPs of the users are the same, the users with higher THP are allocated more

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radio resources. If the THPs of the users are the same, the users with higher ARP are allocated more radio resources. Other services: The BSS allocates the radio resources according to the ARP of the QoS. The users with higher ARP can be allocated more radio resources. For the services that do not support the QoS, the BSS allocates the radio resources according to the BEST EFFORT.

Enhancement GBSS8.1 Mapping between R97/R98 QoS and R99 QoS: If the MS supports only the R97/R98 QoS, that is, the MS does not support the GBR, the BSC maps the R97/R98 QoS to the R99 QoS according to the 3GPP specifications. After the precedence class of the R97/R98 QoS is mapped as the ARP of the R99 QoS, the BSC allocates the radio resources based on the ARP. Configuration of the radio resource allocation priorities: The priorities are configured on the basis of the service types of the QoS, ARP, and THP. For the services that do not support the QoS, the priorities are allocated according to the BEST EFFORT. The BSC allocates the radio resources according to the user priorities. The higher-priority users are allocated more radio resources. This feature enables the operator to allocate the radio resources according to different service types and user priorities and therefore the bandwidth allocation mechanism is more flexible.

Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The MS and the SGSN must support this feature.

2.2.3 GBFD-119904 PS Active Package Management Availability This feature was introduced in GBSS8.1.

Summary With this feature, the server at the application layer adjusts the transmit rate based on the bandwidth that can be provided by the radio links, avoiding IP packet loss and timeout of the IP packet transmission. As a result, the performance of the services such as large-sized email sending, webpage browsing, and file transfer is improved. In addition, the packet performance is greatly improved when multiple services are processed simultaneously.

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Improves the downlink throughput when the quality of the radio link is poor.



Reduces the download time when multiple web pages are downloaded simultaneously.



Ensures high bandwidth usage, reduces the delay of the packet service, and enhances the fairness of the bandwidth seizure of various packet service flows.



Improves the performance of the packet service. For example, when large-sized files are involved in the packet service, such as FTP downloading and email sending, this feature shortens the service delay and therefore improves the user experience.

Description Compared with the reactive queue management (a technique which drops the overflowed packets only when the queue is full), this feature provides active queue management and real-time monitoring of the buffer queue to monitor the network congestion. Once the network is congested, the system drops the data packets proactively and adjusts the sending rate at the TCP sending end to maintain the buffer queue at a certain length to reduce the congestion. Therefore, the throughput of the TCP service is maximized, the data buffer size is reduced, and the interactive time and response time of the services such as webpage browsing are saved. In GSM, the packet service uses the TCP/IP protocol in most cases. When multiple connections co-exist, the strong connection in a system may result in long transmission time over the weak connection. For example, a subscriber clicks a button on an HTTP webpage when FTP downloading is in progress. In such a case, a long time elapses before the corresponding webpage is displayed because the link resource is occupied by the FTP service. The PS active package management is applicable to scenarios where congestion may occur because of bandwidth limitation. It can reduce the network congestion caused by the TCP data flow, so the service throughput is increased and the service delay is decreased. The PS active package management performs queue management for only interactive services, background services, and services that do not support the QoS. The queue management is not performed for real-time services, such as conversational services and streaming services.

Enhancement None

Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None

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Dependency on other NEs None

2.2.4 GBFD-119905 PoC QoS Availability This feature was introduced in GBSS8.1.

Summary The push to talk over cellular (PoC) service is a type of real-time packet service that has high bandwidth and delay requirements. To guarantee the service quality and real-time performance, Huawei GBSS provides the QoS measures such as GBR, reduced data transmission delay, and balanced uplink and downlink channel allocation.

Benefits This feature guarantees the real-time performance of the PoC service, improves the voice quality of the PoC service, and enhances the user experience. It provides the operator with competitive advantages and enables the operator to provide differentiated services for data service subscribers. It also increases the service revenue.

Description The PoC service is a type of group call service implemented on the GSM network. The PoC service adopts the packet switching technology and is carried on the GPRS/EGPRS network. The PoC service involves subscriber authentication, conversation establishment, media dispatching, charging, and strategy control, most of which run on the PoC server in the CN. The PoC signaling and voice data are carried over GPRS/EGPRS. The GBSS transparently transfers these packets to the CN for further processing. In contrast to the packet service, the PoC service carries speech signals and requires low transfer delay. If the transfer delay is high, the user experience is affected. Huawei GBSS is able to identify the PoC service and provides certain measures to guarantee the QoS. These measures include GBR, reduced data transmission delay, and balanced uplink and downlink channel allocation. GBR: The resources are allocated based on the GBR. If the GBR cannot be guaranteed, it is re-negotiated and the resources are then allocated based on the negotiated GBR. Reduced data transmission delay: The services are scheduled based on the priorities. The high-priority services are preferably scheduled and the services with the same priority are scheduled in turn. Balanced uplink and downlink channel allocation: In most cases, the PoC service requires the uplink TBF and downlink TBF simultaneously and symmetrical traffic in the uplink and downlink. Therefore, the balanced uplink and downlink channel allocation enables a similar number of PDCHs to be allocated in the uplink and downlink if the multislot class of the MS permits and if the requirements of GBR are met.

Enhancement None

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Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-119901 Streaming QoS(GBR) Dependency on other NEs The MS and the CN must support this feature.

2.2.5 GBFD-119906 Conversational QoS Availability This feature was introduced in GBSS9.0.

Summary Conversational QoS refers to the QoS of conversational services. This feature means that when an MS subscribes to a network, the services on the MS are registered as conversational services. The BSC processes the services on the MS as conversational services according to the registered QoS information, provided that the MS supports the reduced latency. In this way, the service transmission delay does not exceed 80 ms and the end-to-end delay does not exceed 300 ms, meeting the high requirements of conversational services such as VoIP, PoC, and Gaming for the transmission delay.

Benefits With the development of IP-based services such as VoIP, PoC, and Gaming, the users' requirements for the service transmission delay become increasingly higher. The QoS of conversational services can achieve enhanced QoS and improved user experience. The details are as follows: 

Helping operators to achieve enhanced QoS of PS services, improve the competitiveness of GSM products in the PS domain, and attract more VIP users



Enhancing user experience and improving the core competitiveness of operators



Increasing operators’ revenues by improving the performance of PS services and implementing value-added services such as VoIP and PoC

Description The conversational service is a type of real-time service and has high requirements for the transmission delay. As specified by the related protocol, the transmission delay of conversational services cannot exceed 80 ms. In general, to ensure user satisfaction, the end-to-end delay for VoIP services cannot exceed 300 ms.

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Conversational services use the RTTI TBF so that the requirements of the conversation QoS for transmission delay are met. The scheduling period of radio blocks based on the BTTI TBF is 20 ms and the scheduling period of radio blocks based on the RTTI TBF is 10 ms. If the MS does not support the reduced latency, the BSC also allows the MS to run conversational services. The BSC allocates the BTTI TBF to the MS and tries to meet the requirement of conversation QoS for the transmission delay. Because the capability of the MS is limited, the BSC is unable to guarantee that the MS can meet the requirement of conversation QoS for the transmission delay. Because PS services are transparently transmitted on the BSC, the BSC cannot exactly identify the service type of the MS. Therefore, the BSC can determine the service type only based on the information that the MS registers in the HLR. The criteria for checking whether the services on the MS meet the QoS of conversational services are not the actual services running on the MS but the following two conditions: 1.

Whether conversational services are registered during the registration of the MS

2.

Whether the MS supports the reduced latency

Only when the previous two conditions are met, the transmission delay of services on the MS over the Um interface may meet the requirement of Conversation QoS. If the MS supports the reduced latency, employ the policy of binding the RTTI feature and the FANR feature. The RTTI feature can reduce RTT, and the FANR feature can greatly reduce the response time of the MS in case that the signal quality on the Um interface is poor. Because the current GBSS version supports the RTTI and FANR feature only in IP/HDLC transmission mode, Conversation QoS can be optimally supported in IP/HDLC transmission mode.

Enhancement None

Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. This feature applies only to IP/HDLC networking scenarios, the PEUa/POUc boards are needed as Abis interface board, and the DPUc boards are needed in GMPS/GEPS subrack. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-510805 Latency Reduction Dependency on other NEs The MS and the CN must support this feature.

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2.2.6 GBFD-116201 Network-Controlled Cell Reselection (NC2) Availability This feature was introduced in GBSS6.1.

Summary The network-controlled cell reselection (NC2) refers to the situation that the MS in packet transfer mode can be controlled by the network to reselect a cell according to the measurement report.

Benefits Based on the receive quality of the MS and receive level of the neighboring cell, this feature enables the network-controlled MS to reselect a cell with better receive level. Therefore, the subscriber can obtain better packet service, the performance of the packet service in the whole network is improved, and the resource usage is increased.

Description In NC2 mode, the network instructs the MS to perform cell reselection. In this manner, the MS can reselect a better cell because the network has a clearer view of the actual network condition than the MS does. Therefore, a better network performance is achieved. When the MS is in packet transfer mode, the network helps to reselect a cell with better receive level and lighter load for the MS based on the measurement report and the network load condition. The NC2 is triggered under the following scenarios: 1.

The downlink receive quality of the MS drops rapidly.

2.

The reselection does not occur and the number of received packet measurement reports reaches a certain threshold.

In these cases, the network helps the MS to reselect a cell with better receive level. As a result, the user experience is enhanced, and the performance of the packet service in the whole network is improved.

Enhancement GBSS8.1 Inter-BSC NC2: The network can select the neighboring cell controlled by another BSC as the target cell and initiate the cell re-selection procedure. NC2 based on cell load: When the load of PS services in the cell exceeds a specified threshold, the MS that meets the requirement of neighboring cell level threshold is reselected to the neighboring cell with light load. Support for NC2 of the target cell of the WCDMA system: The network can select the target cell of the WCDMA system for cell reselection based on the measurement reports.

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2.2.7 GBFD-116301 Network Assisted Cell Change (NACC) Availability This feature was introduced in GBSS6.1.

Summary NACC refers to network-assisted cell reselection. To implement rapid PS access after cell reselection, the BSC sends the system information about the target cell to the MS before cell reselection. Therefore, the service interruption time due to the cell reselection is minimized.


Increases the cell reselection speed, minimizes the service interruption time due to the cell reselection, and enhances the user experience.



Adheres to satisfy the services that have higher requirements for delay and throughput (such as the streaming service).



Increases the system capacity because the resources of the original cell can be released rapidly after the cell reselection.

Description The NACC feature enables the MS to access the new cell rapidly after cell reselection and perform data transmission without receiving the complete system information. The NACC feature does not control the cell reselection of the MS, but notifies the network to send the system information in advance when the MS decides to reselect a cell and delays the cell reselection. In this manner, this feature increases the cell reselection speed of the MS, greatly reducing the data transmission interruption time due to cell reselection. Because the cell reselection speed is increased, the MS can rapidly notify the SGSN. The SGSN can then rapidly detect that the cell reselection occurs. As a result, the resources of the original cell can be quickly released to other users and therefore the system capacity is increased.

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Enhancement GBSS8.1 Support for resource reservation in the target cell: When the network receives the cell reselection decision of the MS, it reserves the required radio resources in the target cell to ensure that the MS can obtain sufficient resources for service recovery after reselection. Support for NACC between BSCs or between BSC and RNC: This application enhancement can reduce the delay of cell reselection between BSCs or between the BSC and the RNC. It requires the BSC to support the RIM procedure to obtain the system information of the external cell. During cell reselection, if the BSC has the system information of the external cell, it sends the system information to the MS. Otherwise, the BSC initiates the RIM procedure to request the system information and save the system information for future use.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-114101 GPRS or GBFD-114201 EGPRS Dependency on other NEs The MS and the CN must support this feature.

2.2.8 GBFD-119801 Packet SI Status (PSI) Availability This feature was introduced in GBSS8.0.

Summary With this feature, the MS requests the system information that it requires by sending the Packet SI Status message to the BSC to reduce the service interruption time or service delay.

Benefits This feature is used together with the NACC to reduce the interruption time of the packet service due to cell reselection, improving the packet service quality and enhancing the user experience.

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Description The MS in packet transfer mode notifies the BSC of the system information it requires by sending the Packet SI Status message to the BSC. The BSC then sends the system information to the MS on the PACCH. The MS uses the obtained system information for the packet service being processed to avoid the service interruption or delay. This feature is used together with the NACC to speed up the cell reselection and reduce the service interruption time.

Enhancement None


2.2.9 GBFD-119305 BSS Paging Coordination Availability This feature was introduced in GBSS8.0.

Summary When no Gs interface between the MSC/VLR and SGSN is configured and the MS is in packet transfer state, the network sends CS paging messages through the PACCH. Then, the MS in packet transfer state can respond to the CS paging message.

Benefits With this feature, the MS in packet transfer state can receive the CS paging message, avoiding the drop of network paging rate when the PS services are performed.

Description When the common class B MS is in packet transfer state, it only listens to the paging message on the PACCH. When no Gs interface is configured, the MS in packet transfer state cannot respond to the CS paging message because the CS paging message is sent on the PCH. This problem can be solved through BSS paging coordination.

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After the BSC receives a CS paging message over the A or Gb interface, BSS paging coordination enables the BSC to query whether the MS is performing PS services according to the IMSI carried in the paging message. If the MS is in packet transfer state, the BSC sends a paging message to the MS through the PACCH; if the MS is in idle state, the BSC sends a paging message to the MS through the PCH. BSS paging coordination is independent of the Gs interface between the MSC/VLR and SGSN and is independent of Network Operation Mode I. The GBSC independently determines whether the paging message is sent on the PCH or on the PACCH. If no Gs interface is configured in a network with large amount of PS services, BSS paging coordination helps increase the paging success rate.

Enhancement None

Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-114101 GPRS GBFD-114201 EGPRS Dependency on other NEs MS should support.

2.2.10 GBFD-119502 PS Handover Availability This feature was introduced in GBSS9.0.

Summary The PS handover involves the internal inter-cell handover and the external inter-cell handover (including the inter-RAT handover).

Benefits The interruption period of PS services during handover is shortened, ensuring the QoS of PS services especially conversational services. Therefore, operators can provide more value-added services such as VoIP, PoC, and Gaming to increase revenue.

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Description The PS handover complies with the related 3GPP R6 protocols, mainly the 3GPP TS 44.060, 48.018, and 43.129. Conversational services have high requirement for the interruption period and cell reselection cannot meet this requirement. With the introduction of PS handover, before the MS is handed over, radio resources are allocated to the MS in the target cell. This greatly decreases the latency of cell change and reduces the service interruption period to less than 150 ms. Besides, PS handover takes into account factors such as the signal level and the load in the neighboring cells in advance and therefore ensures the success rate of PS handover and the throughput of the new cell. In this way, QoS is ensured. The PS handover involves the internal inter-cell handover and the external handover (including the inter-RAT handover). In addition, the PS handover involves also the handover triggered by the MS in NC0 or NC1 mode and the handover triggered by the network side in NC2 mode. The GBSS provides performance statistics related to PS handover. Based on the types of PS handover, measurement counters are classified into intra-RAT handover counters, inter-RAT handover counters.

Enhancement None


2.2.11 GBFD-119503 Early TBF Establishment Availability This feature was introduced in GBSS9.0.

Summary The early TBF establishment is a function introduced in 3GPP R7. In the early TBF establishment feature, the TBF is allocated to the MS prior to data transfer. Therefore, the service access delay is shortened.

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Benefits In the early TBF establishment feature, the delay of the uplink data is decreased by as much as hundreds of milliseconds (about the time for TBF establishment) compared with that in the traditional TBF establishment. This improves the user experiences of the session services such as the PoC service and the VoIP service.

Description The packet transfer delay is a key index of the packet services, particularly the delay sensitive session services. The early TBF establishment feature supports the pre-allocation of the TBF before the MS sends data. In this way, the transmission delay of the uplink data is reduced. Generally, the MS applies for the TBF resources only when the MS has data to transmit. The BSC then starts to allocate the TBF resources. In the early TBF establishment feature, the TBF resource application is triggered prior to the data transfer of the MS. The BSC pre-allocates the uplink TBF resources for the MS and sets the TBF to inactive state. In a specified period, the MS can send the data directly without the need for establishing the TBF. After the specified period, the BSC releases the TBF to save the packet transmission resources.

Enhancement None

Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features GBFD-119203 Extended Uplink TBF Dependency on other NEs The MS must support this feature.

2.2.12 GBFD-119504 PS Power Control Availability This feature was introduced in GBSS12.0.

Summary This feature enables the BSC to adjust the transmit power of the BTS according to the link quality of the Um interface. In this way, the desirable link quality can be ensured without requiring the maximum power on the PDCH. The reduced transmit power of the BTS helps decrease the interference in the network and lower the power consumption of the BTS.

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Benefits This feature lowers the BTS transmit power without compromising the link quality. In this way, the network interference and power consumption can be reduced, while the system capacity can be increased.

Description PS power control is classified into PS uplink open-loop power control, PS uplink closed-loop power control, and PS downlink closed-loop power control. PS uplink open-loop power control, supported by the feature GBFD-119115 Power Control, was introduced in GBSS8.0. EGPRS downlink closed-loop power control was introduced in GBSS12.0. In GBSS14.0, GPRS downlink closed-loop power control is introduced, and EGPRS downlink closed-loop power control is enhanced. When this feature is enabled, the MS measures the quality of each downlink radio block and then reports the measured quality to the BSC through the PACKET DOWNLINK ACK/NACK message. After processing the received information, the BSC performs the PS downlink power control decision. If the BSC decides to perform power control, it calculates the power attenuation value by using the PS downlink power control algorithm and then sends the value to the BTS. Based on the received power attenuation value, the BTS adjusts the transmit power on the current radio block. This feature is suitable for a network with densely-scattered sites, high rate of frequency reuse, and a large number of users. By controlling the transmit power on the PDCH in such a network, the network interference and power consumption can be reduced, while the system capacity can be increased.

Enhancement GBSS14.0 1.

GPRS downlink closed-loop power control is added.

2.

EGPRS downlink closed-loop power control is enhanced and related algorithms are optimized. In addition, the issue in GSBB12.0 where a coding scheme decreases due to improper EGPRS downlink closed-loop power control is solved using the following methods:



Power compensation is performed on measurement reports (MRs) during MR preprocessing, and filtering is performed after power compensation, which minimizes the impact of improper power control.



The impact of power control is considered during downlink link adaptation. This avoids a sharp decrease in the coding scheme.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features The following feature cannot be concurrently enabled with this feature:

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2.2.13 GBFD-119505 PDCH Dynamic Adjustment with Two Thresholds Availability This feature was introduced in GBSS12.0.

Summary With this feature, the conversion between PDCH and TCH can be dynamically performed according to the traffic load in the cell. This feature ensures the speech quality of the cell, reduces the possibility of CS services preempting the radio resources of PS services, and effectively improves the channel utilization.

Benefits This feature improves the CS access performance (indicated by the call setup success rate and access delay) and PS retainability performance (indicated by the TBF call drop rate in uplink and downlink).

Description If the rate of idle channels in a cell is greater than the higher threshold for CS idle channel rate, the CS traffic in the cell is light. In this case, idle TCHs can be dynamically converted into PDCHs to improve the throughput of PS services. If the rate of idle channels in a cell is smaller than the lower threshold for CS idle channel rate, the CS traffic in the cell is heavy. In this case, PDCHs can be dynamically converted into TCHs to reduce the possibility of CS services preempting the radio resources of PS services. If the rate of idle channels in a cell is greater than the lower threshold for CS idle channel rate and at the same time smaller than the higher threshold for CS idle channel rate, the CS traffic load and PS traffic load in the cell are balanced. In this case, the dynamic conversion between PDCH and TCH does not need to be performed. The higher threshold for CS idle channel rate and lower threshold for CS idle channel rate are configured on the basis of the traffic load in the cell.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None

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2.2.14 GBFD-119506 GPRS/EGPRS Time slot multiplexing priority Availability This feature was introduced in GBSS13.0.

Summary When a GPRS user and an EGPRS user are multiplexed onto the same PDCH, the downlink rate of the EGPRS user can be increased by adjusting the scheduling priority of the EGPRS user to a level higher than that of the GPRS user. Based on the downlink rate increase, the service experience of EGPRS users is improved, and the system throughput is increased.

Benefits Operators can attract users to EGPRS services or GPRS services by adjusting the multiplexing priorities of GPRS and EGPRS users on the PDCH, thereby increasing the downlink rate of EGPRS users. Based on the downlink rate increase, the PS service experience of EGPRS users is improved, and the system throughput is increased.

Description By setting scheduling weight parameters related to EGPRS and GPRS users in a cell, operators can adopt different uplink and downlink scheduling strategies for EGPRS users and GPRS users, thereby improving the service experience of EGPRS users. When an EGPRS user and a GPRS user are multiplexed onto the same PDCH, the radio block sent in downlink to the EGPRS user must be in the GMSK modulation mode during the scheduling of the uplink radio block of the GPRS user. This decreases the downlink rate of the EGPRS user. If the scheduling priority of the GPRS user is lower than that of the EGPRS user, the number of times that the downlink radio block of the EGPRS user uses the GMSK modulation mode is decreased, because scheduling times of the uplink radio block of the GPRS user are less than the scheduling times of the uplink radio block of the EGPRS user. In addition, the scheduling times of the downlink radio block of the EGPRS user are more than the scheduling times of the downlink radio block of the GPRS user. Therefore, the downlink rate of the EGPRS user and the system throughput are increased.

Enhancement None


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Dependency on other GBSS features None Dependency on other NEs None

2.2.15 GBFD-119401 Extended Dynamic Allocation (EDA) Availability This feature was introduced in GBSS8.0.

Summary EDA helps assign more timeslots in the uplink to the MS, improving the uplink throughput.

Benefits This feature improves the uplink rate and helps transmit large amount of data in the uplink. In this way, the user satisfaction is improved.

Description Generally, the GPRS/EGPRS downlink services outnumber the GPRS/EGPRS uplink services. However, in some cases, a higher uplink bandwidth is required; for example, a large-sized email is sent through the GPRS/EGPRS. The EDA feature enables a single MS to be assigned with four timeslots in the uplink. If the MS high multislot classes feature is supported, the MS with the high multislot class 34 can be assigned with five timeslots in the uplink, meeting the high bandwidth requirements in the uplink. EDA is based on the uplink dynamic allocation. The network assigns multiple timeslots in the uplink to the MS. The MS listens to all the assigned PDCHs. When the MS hears the assigned USF on the assigned PDCH, the MS uses the uplink block corresponding to this PDCH and the uplink block corresponding to the assigned PDCH with a greater timeslot number. Once the MS is able to send uplink blocks, it will not listen to the following assigned channels. Therefore, the MS can use more uplink channels. The uplink extended dynamic allocation requires the support from the MS. The MS will indicate whether it supports GPRS uplink extended dynamic allocation and EGPRS uplink extended dynamic allocation through the message containing the information about radio access capability.

Enhancement None

Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware

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For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs MS should support.

2.2.16 GBFD-119402 MS High Multislot Classes Availability This feature was introduced in GBSS8.1.

Summary High multislot classes ensure that a maximum of five timeslots in the uplink or downlink are assigned to a single MS, improving the uplink or downlink throughput of a single MS.

Benefits The BSS supports the MS with a high multislot class of 30 to 34. A maximum of five timeslots on the downlink can be assigned to an MS. If an MS is of the high multislot class 34, a maximum of five timeslots in the uplink can be assigned to the MS. Therefore, compared with four timeslots in the uplink or downlink, the throughput is increased by 25%.

Description The BSS supports the MS with high multislot classes from 30 to 34. A maximum of five timeslots on the downlink can be assigned to an MS. If an MS is of the high multislot class 34, a maximum of five timeslots in the uplink can be assigned to the MS. For a GPRS MS, the maximum data rate increases from 85 kbit/s to 107 kbit/s (the throughput at RLC in theory); for an EGPRS MS, the maximum data rate increases from 236 kbit/s to 296 kbit/s (the throughput at RLC in theory). The total number of timeslots on both the uplink and downlink cannot exceed six. That is, if five timeslots on the downlink are assigned to the MS, then only one timeslot in the uplink can be assigned to the MS. The following table lists the multislot capacity of MSs with multislot classes 30 to 34: High Multislot Class

Maximum Number of Downlink Timeslots

Maximum Number of Uplink Timeslots

Maximum Number of Timeslots

30

5

1

6

31

5

2

6

32

5

3

6

33

5

4

6

34

5

5

6

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For an MS with high multislot classes 32 to 34, if more than two timeslots in the uplink are assigned to the MS, EDA function must be enabled.

Enhancement None

Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-114101 GPRS GBFD-114201 EGPRS If more than two timeslots in the uplink are required, the GBFD-119401 EDA must be used. Dependency on other NEs The MS must support this feature.

2.2.17 GBFD-114151 DTM Availability This feature was introduced in GBSS8.1.

Summary Dual Transfer Mode (DTM) allows simultaneous transfer of CS service and PS service. That is, a subscriber can send photos or browse websites during the call conversation. The 3G network provides concurrent CS service and PS service. With DTM, the subscribers in a GSM network can enjoy services similar to those provided in a 3G network. In addition, in areas with insufficient 3G coverage, subscribers can use the services that are similar to 3G services through the GSM network.

Benefits DTM supports concurrent CS service and PS service. That is, a subscriber can provide PS service without affecting the CS service. With DTM, the concurrent CS services and PS services which are originally available only in the 3G network are now available in the GSM network. With the passage of time and development of technology, the data services are becoming the new area of profit growth. The concurrent CS service and PS service becomes a new requirement. Without DTM, only the class A mobile phone with complex hardware supports concurrent CS service and PS service. However, due to its complexity, few manufacturers

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provide such mobile phones. The implementation of DTM is a foundation for the extensive application of data service. With the interaction between the CS services and PS services and the multimedia services provided by operators, the call duration is prolonged and a large amount of data traffic is generated. This considerably increases the revenue of operators.

Description DTM is a 3GPP-defined standard function. This feature implements the simplified operation function of the class A mobile phone, that is, concurrent CS services and PS services. In DTM mode, the CS resource (TCH) and PS resource (PDCH) are assigned to the MS simultaneously. According to the multislot capacity of the MS, different number of channels in the uplink or downlink can be assigned to the MS to meet the requirement for different bandwidths. DTM supports MS with multislot class 5 and higher classes. According to the MS multislot capacity, the BSC assigns two channels in the uplink or downlink to the MS: one for CS services and the other for PS services. The MS multislot class 9 with DTM can be assigned with one channel for CS service and two channels for PS service.

PS

CS

PS

PS

CS

CS

PS

PS

CS

CS

PS

PS

CS

Downlink

CS

PS

PS

CS

Uplink

PS

Downlink Uplink CLASS 5

CLASS 9

After DTM is enabled, the BSC must support BSS paging coordination in packet transfer mode if the Network Operation Mode II or III is configured in a cell. For an MS supporting DTM, when the MS initiates a location update in CS mode, the CS channels (FACCH or SDCCH) can be used for location update and no PDCH is required. In this case, the channel resources in PS domain are saved. In DTM mode, the MS can establish the PS connection only after the PS connection is established. If an MS providing data service needs to switch to the DTM mode, the TBF must be released first; then, the MS switches to CS mode and a TBF connection. After that, the MS switches to DTM mode. The following figure shows the state transition in DTM mode:

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Figure 2-1 State transition in DTM mode

Enhancement None

Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-114001 Extended Cell GBFD-116201 Network-Controlled Cell Reselection (NC2) Dependency on other NEs The MSC, SGSN, and MS must support this feature.

2.2.18 GBFD-119403 Class11 DTM Availability This feature was introduced in GBSS8.1.

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Summary Based on the common DTM feature, Class 11 DTM doubles the bandwidth of the uplink PS services of the MS. When an MS using Class11 DTM provides mainly uplink service, the channel assignment of Speech + 1Downlink + 2Uplink is supported. That is, two uplink PDCHs and one downlink PDCH are assigned to the MS.

Benefits Based on common DTM, Class 11 DTM doubles the uplink rate. Theoretically, the uplink rate of the EGPRS MS can reach 110 kbit/s. Class11 DTM provides the bandwidth to support streaming services. With the Class 11 DTM function, the uplink rate or downlink rate can be increased according to requirement, improving the user experience. In addition, the increased data flow can also increase the revenues of operators.

Description In DTM mode, the MS supports both CS service and PS service simultaneously. Besides supporting the channel combination of Class11 DTM and Class9 DTM, the MS using Class11 DTM can occupy two uplink PDCHs and one downlink PDCH used together with EDA. When the MS provides mainly the uplink services, Class11 DTM meets the requirements of the MS more effectively.

PS

CS

PS

CS

Downlink PS

Uplink

CLASS

11

Enhancement None

Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-114151 DTM GBFD-119401 EDA Dependency on other NEs DTM should be supported by the MSC and SGSN. Class11 DTM should be supported by the MS.

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2.2.19 GBFD-119404 HMC DTM Availability This feature was introduced in GBSS8.1.

Summary Based on common DTM, HMC DTM improves the bandwidth of the uplink and downlink PS services of the MS. The MS can occupy a maximum of three uplink and downlink PDCHs respectively during a call. The following channel assignments are supported: Speech + 3Downlink + 1Uplink, Speech + 2Downlink + 2Uplink, and Speech + 1Downlink + 3Uplink.

Benefits Based on common DTM, HMC DTM triples the uplink and downlink rates. This improves the user experience and provides bandwidth to support streaming services. In addition, the increased data flow can also increase the revenues of operators.

Description The DTM multislot classes defined in 3GPP protocols are classes 5, 6, 9, 10, 11, 31,33, 36-38, and 41–44. The classes higher than class 31 are called High Multislot classes DTM (HMC DTM). The DTM multislot capacity is in direct proportion to the uplink/downlink rate. The higher the DTM multislot class supported by the GBSS equipment, the higher the uplink/downlink rate. Huawei HMC DTM supports multislot classes 31,33. In other words, based on the multislot capacity of MS, a maximum of five channels in the uplink or downlink can be assigned to the MS. The maximum number of channels on both the uplink and downlink is six. Except one TCH assigned to the speech in the uplink and downlink respectively, a maximum of three PDCHs in the uplink or downlink can be assigned to the MS.

The following table lists the multislot capacity of MSs with multislot classes 31 to 33: Multislot class

Maximum number of slots Rx

Tx

Sum

31

5

2

6

33

5

4

6

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For an MS with multislot classes 32 and 33, if more than three channels in the uplink are assigned to the MS, EDA must be enabled.

Enhancement None

Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-114101 DTM GBFD-119401 EDA GBFD-119402 MS High Multislot Classes Dependency on other NEs DTM should be supported by the MSC and SGSN. DTM HMC should be supported by the MS.

2.2.20 GBFD-119405 14.4kbit/s Circuit Switched Data Availability This feature was introduced in GBSS8.1.

Summary The GBSS equipment supports the transfer of PS services on individual speech channels with a high rate of 14.4 kbit/s.

Benefits Compared with common CS-based PS services, this feature provides PS services with higher bandwidth.

Description Huawei GBSS system supports different types of bearer services specified by GSM specifications. The GBSS provides lower-layer connections and transmits service data to the upper layer instead of processing these services. Huawei GBSS system supports the transfer of the PS services on individual speech channels and the CS-based PS services with a high rate of 14.4 kbit/s.

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Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The MSC must support this feature.

2.2.21 GBFD-119406 High Speed Circuit Switched Data Availability This feature is introduced in GBSS14.0.

Summary With this feature, the Huawei GBSS can transmit high speed circuit switched data (HSCSD) services on up to four TCHs at a rate of up to 57.6 kbit/s.

Benefits This feature increases the bandwidth for CSD services to support more service types and improve user experience.

Description The Huawei GBSS supports multislot binding technology, which binds a maximum of four TCHs to form a channel group to carry HSCSD services. This increases data transmission rates from 14.4 kbit/s to 57.6 kbit/s, improving user experience. The following tables list the HSCSD service rates supported by the Huawei GBSS using different channel coding modes. HSCSD service rates using 9.6 kbit/s transparent channel coding mode Table 2-1 9.6 kbit/s transparent channel coding mode HSCSD Rate

Binding Mode

9.6 kbit/s

1 x 9.6 kbit/s

19.2 kbit/s

2 x 9.6 kbit/s

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HSCSD Rate

Binding Mode

28.8 kbit/s

3 x 9.6 kbit/s

38.4 kbit/s

4 x 9.6 kbit/s

HSCSD service rates using 14.4 kbit/s transparent channel coding mode Table 2-2 14.4 kbit/s transparent channel coding mode HSCSD Rate

Binding Mode

14.4 kbit/s

1 x 14.4 kbit/s

28.8 kbit/s

2 x 14.4 kbit/s

43.2 kbit/s

3 x 14.4 kbit/s

57.6 kbit/s

4 x 14.4 kbit/s

Table 2-3 HSCSD service rates using 12 kbit/s non-transparent channel coding mode12 kbit/s non-transparent channel coding mode HSCSD Rate

Binding Mode

12 kbit/s

1 x 12 kbit/s

24 kbit/s

2 x 12 kbit/s

36 kbit/s

3 x 12 kbit/s

48 kbit/s

4 x 12 kbit/s

Table 2-4 HSCSD service rates using 14.5 kbit/s non-transparent channel coding mode 14.5 kbit/s non-transparent channel coding mode HSCSD Rate

Binding Mode

14.5 kbit/s

1 x 14.5 kbit/s

29.0 kbit/s

2 x 14.5 kbit/s

43.5 kbit/s

3 x 14.5 kbit/s

58 kbit/s

4 x 14.5 kbit/s

Transparent HSCSD calls must satisfy the listed rate requirements. If contiguous idle TCHs are insufficient in a cell due to congestion, these calls cannot be processed in the cell. Rates for non-transparent HSCSD calls may change. If contiguous idle TCHs are insufficient in a cell due to congestion, actual data transmission rates may be lower than the requested

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rates. When the cell is idle, additional TCHs are allocated to non-transparent HSCSD calls to satisfy the requested data rates. MSs under the Huawei GBSS can initiate the addition or subtraction of TCHs during a non-transparent HSCSD service process. Dual-timeslot extended cells do not support HSCSD services. Transparent HSCSD services cannot be handed over to a dual-timeslot extended cell. If non-transparent HSCSD services are handed over to such a cell, they have to use a single timeslot. Currently, no MS supports the 57.6 kbit/s HSCSD service, and therefore this service cannot be tested.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-117002 IBCA GBFD-117001 Flex MAIO Dependency on other NEs The MS and the CN must support this feature.

2.2.22 GBFD-119407 Active TBF Allocation Availability This feature is introduced in GBSS14.0.

Summary Active TBF Allocation monitors temporary block flow (TBF) transmission in real time, helping users learn about the transmission quality of TBFs and channels in a cell. This provides guidelines for allocating PDCHs to TBFs and converting dynamic PDCHs. This feature enables low-throughput services to preferentially use a tight frequency reuse pattern and high-throughput services to preferentially use a loose frequency reuse pattern. In addition to reducing the number of activated PDCHs and improving the efficiency for PDCHs to carry TBFs, this feature improves the user experience with high-throughput services, reduces interference to CS services and the proportion of HR channels to all channels, and improves the mean opinion score (MOS) for CS services.

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Benefits 

Avoids unnecessary capacity expansion and brings economic benefit because the number of activated PDCHs is reduced by about 25%, and the efficiency for PDCHs to carry TBFs is increased by about 20%.



Reduces interference from PDCHs to the network because the number of PDCHs is reduced. The MOS for CS services is increased because the proportion of HR channels to all channels is reduced by 10%, and the high quality indicator (HQI) is increased by about 0.2%.



Allocates resources to PS services more efficiently and maintains a high data rate for PS services while occupying fewer resources.

Description This feature increases the number of TBFs carried over each PDCH without affecting the network access and transmission performance. This increases the efficiency for PDCHs to carry TBFs and reduces the number of activated PDCHs. Only data transmission occupies transmission resources on the Um interface during a TBF duration, but data transmission time accounts for only part of the life cycle of a TBF. For low-throughput services, data transmission time accounts for a small part of the life cycle of a TBF. This leads to a low efficiency for PDCHs to carry TBFs, which wastes channel resources. This feature provides the following functions: 

Samples and measures TBF multiplexing rates

This feature monitors the TBF status in real time and quickly samples the TBF status. If a TBF is in transfer mode, the BSC records the sampling value as 1. Otherwise, the BSC records the sampling value as 0. In addition, the feature filters the sampling values to obtain the filtered TBF multiplexing rates. When an MS accesses a cell or resources are reallocated, this feature accumulates the filtered TBF multiplexing rates to obtain the TBF multiplexing rate for each PDCH, which is then used for channel allocation. 

Manages PDCHs based on the TBF multiplexing rate This feature allocates or reallocates PDCHs and coverts dynamic PDCHs based on the obtained TBF multiplexing rate. The procedures for allocating or reallocating PDCHs and converting dynamic PDCHs remain unchanged. This function applies to hot spots for PS services with the following characteristics: −

The throughput is about 3 kbit/s to 5 kbit/s per PDCH.

−

Instant messaging (IM) services account for more than 40% of PS services, and the traffic of IM services accounts for about 10% of the total traffic.

−

The CS traffic is heavy during busy hours.

−

The traffic carried on HR channels accounts for about 30% of the total traffic.

−

The TCH congestion rate is about 1%.

In these hot spots, Active TBF Allocation brings the following gains: 

The number of activated PDCHs is reduced by about 25%.



The efficiency for PDCHs to carry TBFs (data rate per PDCH at the RLC layer) is expected to increase by about 25%.



The MOS is improved because the proportion of HR channels for CS services is reduced by 10%, and the HQI for CS services is increased by 0.2%.

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If this feature is enabled, ensure that the following items do not deteriorate: 

Data rate per user at the logical link control (LLC) layer



Uplink or downlink TBF call drop rate for EGPRS or GPRS services



PS service throughput

Enhancement None


2.3 EDGE Evolution 2.3.1 GBFD-510801 MSRD Availability This feature was introduced in GBSS9.0.

Summary MSRD is the abbreviation for MS Station Receiver Diversity.

Benefits 

The receiver sensitivity of the MS is increased by about 3 dB and the downlink coverage distance is increased.



In conjunction with the dual-antenna interference cancellation (DAIC) technology, the MSRD feature improves the anti-interference capability of the downlink, expanding the downlink traffic capacity.

Description The MSRD feature improves the signal receiving capability of the MS. With the introduction of the DAIC technology, the MS obtains enhanced channel diversity. In addition, the GMSK

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modulation scheme has an equivalent anti-interference capability with the 8-PSK modulation scheme. Therefore, the data rate of the MS is improved and increases system capacity.

Enhancement None

Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features The MS performing GBFD-510802 Dual Carriers in Downlink cannot perform GBFD-510801 MSRD. Dependency on other NEs The MS must support this feature.

2.3.2 GBFD-510802 Dual Carriers in Downlink Availability This feature was introduced in GBSS9.0.

Summary Dual Carriers in Downlink is a method of increasing the downlink data rate. By using the second downlink carrier, the downlink data rate is doubled theoretically.

Benefits The downlink data rate is greatly increased. In this way, the GSM network can provide subscribers with data services similar to those provided in a 3G network.

Description The basic idea of the Dual Carriers in Downlink feature is to increase the number of timeslots used by the base station to transmit data to an MS in a radio block period. The MS data rate is increased by increasing the number of reception timeslots. The two carriers must be on the same frequency band. Take an MS supporting EGPRS2-A as an example. In a radio block period, the MS can receive the data on only one carrier and the maximum number of timeslots that can be assigned is five. Assume that the highest-rate coding scheme DAS12 is used. Then, the data rate on each timeslot is 98.4 kbit/s, and the maximum data rate of the MS is 98.4 x 5 = 492 kbit/s. With the introduction of the technology of Dual Carriers in Downlink, the MS can receive the data on two carriers in one radio block period. Therefore, the maximum number of

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timeslots is 10. Assume that the DAS12 is used. Then, the maximum data rate of the MS is 98.4 x 10 = 984 kbit/s.

Enhancement None

Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features The MS performing GBFD-510801 MSRD cannot perform GBFD-510802 Dual Carriers in Downlink. This feature relies on the following features: GBFD-114201 EGPRS Dependency on other NEs The MS must support this feature.

2.3.3 GBFD-510803 Uplink EGPRS2-A Availability This feature is available for beta use from GBSS9.0.

Summary The higher uplink performance for GERAN evolution (HUGE) solution is divided into two phases: EGPRS2-A and EGPRS2-B. The uplink EGPRS2-A is the first phase of the solution. With 16QAM modulation, this feature increases the rate of PS services by up to 30% in the uplink theoretically.

Benefits The rate of PS services in the uplink is increased greatly. When four timeslots are used for uplink data transmission, the theoretical rate of EGPRS is increased from 230 kbit/s to 300 kbit/s.

Description One of the aims of the GSM/EDGE radio access network (GERAN) evolution is to increase the uplink and downlink rate of PS services. For the 3GPP GERAN, the HUGE solution is used to increase the data rate in the uplink. With the 16QAM modulation, the GSM/EGPRS network supports higher uplink data rate.

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The uplink EGPRS2-A is the first phase of HUGE. With this feature, the rate of PS services in the uplink is almost increased by 30% in theory. When four timeslots are used for uplink data transmission, the theoretical rate of EGPRS is increased from 230 kbit/s to 300 kbit/s.

The new coding schemes supported by EGPRS2-A are listed in the following table. UAS-11

UAS-10

UAS-9

UAS-8

UAS-7

MCS Coding Scheme Modulation Scheme

16QAM

Family

B

Apad10

A

B

Apad10

Bit Rate (kbps/TS)

44.8

51.2

59.2

67.2

76.8

Number of RLC Data Blocks

2

2

2

3

3

Payload (octets)

2x56

2x64

2x74

3x56

3x64

This feature applies only to Abis interface IP networking scenarios, including Abis IP over E1/T1/cSTM-1 and Abis IP over FE/GE. Does not apply to Abis interface TDM networking scene, that is, Abis TDM over E1/T1/cSTM-1. Due to less terminal support Uplink EGPRS2-A, this feature is provided for trial, does not recommend for commercial use.

Enhancement None


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A built-in PCU, a packet processing board, and a Gb interface board are required. This feature applies only to IP networking scenarios, the PEUa/POUc boards are needed as Abis interface board, and the DPUc boards are needed in GMPS/GEPS subrack. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature relies on the following features: GBFD-118601 Abis over IP or GBFD-118611 Abis IP over E1/T1 or GBFD-118401 Abis Transmission Optimization Dependency on other NEs The MS must support this feature.

2.3.4 GBFD-510804 Downlink EGPRS2-A Availability This feature is available for beta use from GBSS9.0.

Summary The reduced symbols duration/higher order modulation and Turbo codes (REDHOT) solution is divided into two phases: downlink EGPRS2-A and downlink EGPRS2-B. The downlink EGPRS2-A is the first phase of the solution. With 16QAM and 32QAM modulation, this feature almost doubles the rate of PS services in the downlink theoretically.

Benefits The rate of PS services on the downlink is almost doubled. When ten timeslots are used on the downlink, the theoretical data rate of EGPRS is increased from 592 kbit/s to 984 kbit/s.

Description One of the aims of the GSM/EDGE radio access network (GERAN) evolution is to increase the uplink and downlink rate of PS services. For the 3GPP GERAN, the REDHOT solution is used to increase the data rate on the downlink. With higher order modulation (16QAM and 32QAM), high symbol rate (1.2 times), and Turbo codes, the GSM/EGPRS network supports higher downlink data rate. The downlink EGPRS2-A is the first phase of REDHOT. With this feature, the rate of PS services on the downlink is doubled in theory. When ten timeslots are used on the downlink, the theoretical data rate of EGPRS is increased from 592 kbit/s to 984 kbit/s.

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The new coding schemes supported by EGPRS2-A are listed in the following table. DAS-12

DAS-11

DAS-10

DAS-9

DAS-8

DAS-7

DAS-6

DAS-5

MCS Coding Scheme Modulation Scheme

8PSK

Family

B

Ap

Bp

B

Ap

Bp

Ap

Bp

Bit Rate (kbps/TS)

22 .4

27.2

32.8

44.8

54.4

65.6

81.6

98.4

Number of RLC Data Blocks

1

2

3

Payload (octets)

1x 56

2x82

3x68

16QA-M

32QAM

2

1x6 8

1x82

2x56

2x68

3x82

This feature applies only to Abis interface IP networking scenarios, including Abis IP over E1/T1/cSTM-1 and Abis IP over FE/GE. Does not apply to Abis interface TDM networking scene, that is, Abis TDM over E1/T1/cSTM-1. Due to less terminal support Uplink EGPRS2-A, this feature is provided for trial, does not recommend for commercial use.

Enhancement None

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Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. This feature applies only to IP networking scenarios, the PEUa/POUc boards are needed as Abis interface board, and the DPUc boards are needed in GMPS/GEPS subrack. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature relies on the following features: GBFD-118601 Abis over IP or GBFD-118611 Abis IP over E1/T1 or GBFD-118401 Abis Transmission Optimization Dependency on other NEs The MS must support this feature.

2.3.5 GBFD-510805 Latency Reduction Availability This feature was introduced in GBSS9.0.

Summary The Latency Reduction feature consists of two sub-features: Reduced Transmission Time Interval (RTTI) and Fast Ack/Nack Report (FANR).

Benefits This feature reduces the packet transmission latency and therefore improves the customer satisfaction.

Description Latency reduction is important to GERAN evolution. In GERAN, the conversational services, such as VoIP and Gaming, require short service latency. For the VoIP service that meets customer requirements, the end-to-end latency should not exceed 300 ms, and the Frame Error Rate (FER) should not exceed 2%. If the latency is within the permissible range, data can be retransmitted to meet the FER requirement, improving customer satisfaction. In addition, short latency can improve the customer experience of interactive and streaming services. Two technologies can be used to reduce latency: RTTI and FANR. RTTI: One radio block is still transmitted over four bursts, whereas two timeslots are combined. Each timeslot transmits radio blocks of 10 ms TTI. In this way, the four bursts are transmitted on two consecutive TDMA frames.

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With the introduction of RTTI, the transmission latency on the Um interface and the TTI in the access network are reduced. The TTI is reduced from 130 ms (the basic TTI is 20 ms) to 60 ms (the RTTI is 10 ms), and the single retransmission latency is reduced from 185 ms (Basic TTI) to 95 ms (the RTTI is 10 ms). FANR: Although RTTI can reduce transmission latency, under the existing Ack/Nack reporting policy, when an RLC data block is erroneous or missing, this problem is not immediately reported to the sender and another RLC data block is not retransmitted. As a result, latency is required for assembling RLC data blocks into an LLC PDU. Therefore, an efficient Ack/Nack feedback policy helps reduce the LLC PDU reassembly latency. Huawei BSC supports FANR and enables the immediate feedback of data errors and the retransmission of RLC data blocks. In this way, the LLC PDU reassembly latency is decreased and the signaling overhead is reduced.

This feature applies only to Abis interface IP networking scenarios, including Abis IP over E1/T1/cSTM-1 and Abis IP over FE/GE. Does not apply to Abis interface TDM networking scene, that is, Abis TDM over E1/T1/cSTM-1.

Enhancement None

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Dependency Dependency on BSC hardware A built-in PCU, a packet processing board, and a Gb interface board are required. This feature applies only to IP networking scenarios, the PEUa/POUc boards are needed as Abis interface board, and the DPUc boards are needed in GMPS/GEPS subrack. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature relies on the following features: GBFD-118601 Abis over IP or GBFD-118611 Abis IP over E1/T1 or GBFD-118401 Abis Transmission Optimization This feature is mutually exclusive with the following features: GBFD-114151 DTM Dependency on other NEs The BTS and MSs must support this feature.

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3

Smart MBB

3.1 Intelligent Channel 3.1.1 GBFD-511603 IM Service Efficiency Improvement Availability This feature is introduced in GBSS14.0.

Summary With this feature, the BSC provides the following functions to increase channel usage: 

Identifies IM services from various PS services.



Allocates fewer channels to process IM services based on configuration policies.



Multiplexes IM services on a PDCH.



Shortens the delay for releasing downlink TBFs.



Reduces the priority for scheduling IM services.

Benefits The efficiency for PDCHs to carry TBFs is increased by 50% to 100% for IM services.

Description Traditional PDCH management is based on the MS multislot capability and the average number of MSs using the services carried on a PDCH. To ensure that user experience is not affected, the BSC allocates as many PDCHs as needed to an MS based on the MS multislot capability. This is done because the BSC cannot predict the PS service throughput. If the average number of MSs using the services carried on a PDCH exceeds a specified threshold, the BSC triggers excessive dynamic PDCH conversions. Currently, IM services account for a large portion of GSM services, but the TBF transmission duration is short because of low throughput. As a result, procedures in which no data block is transmitted, such as TBF establishment, delayed downlink TBF release, and TBF release, account for a large part of a TBF life cycle. This wastes channel resources. This feature is implemented as follows:


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1.

The BSC uses an NIUa board to identify PS services.

2.

The BSC identifies IM services from various PS services.

3.

The BSC supports the setting of the following parameters for IM services:

4.

−

Maximum Number of PDCHs for IM ARP 1

−


−


−

IM ARP1 Scheduling Weight

−


−


−

IM PDCH Multiplexing Weight

−

IM Downlink TBF Release Delay

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The BSC allocates radio resources to IM services during peak hours based on the maximum number of configured PDCHs, priority weight, PDCH multiplexing weight, and delay for releasing downlink TBFs.

Enhancement None

Dependency Dependency on BSC hardware The NIUa board is required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs None

3.1.2 GBFD-511604 Web Browsing Service Efficiency Improvement Availability This feature is introduced in GBSS14.0.

Summary With this feature, the BSC provides the following functions to improve the user experience with regard to web browsing services: 

Identifies web browsing services from various PS services.



Allocates an appropriate number of channels to process web browsing services.



Sets an appropriate multiplexing weight.

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GBSS14.0 Optional Feature Description 

Sets an appropriate delay for releasing downlink TBFs.



Increases the priority for scheduling web browsing services.

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Benefits The user experience is improved with regard to web browsing services.

Description Traditional PDCH management is based on the MS multislot capability and the average number of MSs using the services carried on a PDCH. To ensure that user experience is not affected, the BSC allocates as many PDCHs as needed to an MS based on the MS multislot capability. This is done because the BSC cannot predict the PS service throughput. If the average number of MSs using the services carried on a PDCH exceeds a specified threshold, the BSC triggers excessive dynamic PDCH conversions. Currently, web browsing services account for a large portion of GSM services. Such services have medium throughput and a high requirement for delay. This feature is implemented as follows: 1.


2.

The BSC identifies web browsing services from various PS services.

3.

The BSC supports the setting of the following parameters for web browsing services:

4.

−

Maximum Number of PDCHs for Web Browsing ARP 1

−


−


−

Web Browsing ARP1 Scheduling Weight

−


−


−

Web Browsing PDCH Multiplexing Weight

−

Web Browsing Downlink TBF Release Delay

The BSC allocates radio resources to web browsing services during peak hours based on the maximum number of configured PDCHs, priority weight, PDCH multiplexing weight, and delay for releasing downlink TBFs.

Enhancement None

Dependency Dependency on BSC hardware The NIUa board is required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None

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3.1.3 GBFD-511605 Email Service Efficiency Improvement Availability This feature is introduced in GBSS14.0.

Summary With this feature, the BSC provides the following functions to improve user experience with regard to email services or to increase the efficiency for PDCHs to carry TBFs for email services: 

Identifies email services from various PS services.



Allocates an appropriate number of channels to process email services.



Sets an appropriate multiplexing weight.



Sets an appropriate delay for releasing downlink TBFs.



Increases the priority for scheduling email services.

Benefits This feature provides the following benefits: 1.

The user experience is improved with regard to email services.

2.

The efficiency for PDCHs to carry TBFs for email services is increased.

Description Traditional PDCH management is based on the MS multislot capability and the average number of MSs using the services carried on a PDCH. To ensure that user experience is not affected, the BSC allocates as many PDCHs as needed to an MS based on the MS multislot capability. This is done because the BSC cannot predict the PS service throughput. If the average number of MSs using the services carried on a PDCH exceeds a specified threshold, the BSC triggers excessive dynamic PDCH conversions. Currently, email services account for a certain portion of GSM services. Such services have high throughput and a low requirement for delay. This feature is implemented as follows: 1.


2.

The BSC identifies email services from various PS services.

3.

The BSC supports the setting of the following parameters for email services:

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Maximum Number of PDCHs for Email ARP 1

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−


−

Email ARP1 Scheduling Weight

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Email ARP2 Scheduling Weight

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Email ARP3 Scheduling Weight Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd

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4.

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Email PDCH Multiplexing Weight

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Email Downlink TBF Release Delay

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The BSC allocates radio resources to email services during peak hours based on the maximum number of configured PDCHs, priority weight, PDCH multiplexing weight, and delay for releasing downlink TBFs.

Enhancement None


3.1.4 GBFD-511606 Streaming Media Service Resource Balancing Availability This feature is introduced in GBSS14.0.


Identifies streaming media services from various PS services.



Reduces the number of PDCHs allocated to streaming media services.



Multiplexes more streaming media services on a PDCH.






Reduces the priority for scheduling streaming media services.

Benefits This feature improves user experience with regard to other GSM services.

Description Traditional PDCH management is based on the MS multislot capability and the average number of MSs using the services carried on a PDCH. To ensure that user experience is not affected, the BSC allocates as many PDCHs as needed to an MS based on the MS multislot

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capability. This is done because the BSC cannot predict the PS service throughput. If the average number of MSs using the services carried on a PDCH exceeds a specified threshold, the BSC triggers excessive dynamic PDCH conversions. Currently, streaming media services account for a small portion of GSM services. Such services have a large throughput and a high requirement for delay, but the spectral efficiency of GSM networks is limited. Therefore, the streaming media services are not recommended for GSM networks. This feature is implemented as follows: 1.


2.

The BSC identifies streaming media services from various PS services.

3.

The BSC supports the setting of the following parameters for streaming media services:

4.

−

Maximum Number of PDCHs for Streaming Media ARP1

−


−


−

Streaming Media ARP1 Scheduling Weight

−


−


−

Streaming Media PDCH Multiplexing Weight

−

Streaming Media Downlink TBF Release Delay

The BSC allocates radio resources to streaming media services during peak hours based on the maximum number of configured PDCHs, priority weight, PDCH multiplexing weight, and delay for releasing downlink TBFs.

Enhancement None


3.1.5 GBFD-511607 P2P Resource Balancing Availability This feature is introduced in GBSS14.0.

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Identifies point to point (P2P) services from various PS services.



Reduces the number of PDCHs allocated to P2P services.



Multiplexes more P2P services on a PDCH.






Reduces the priority for scheduling P2P services.

Benefits This feature improves user experience with regard to other GSM services.

Description Traditional PDCH management is based on the MS multislot capability and the average number of MSs using the services carried on a PDCH. To ensure that user experience is not affected, the BSC allocates as many PDCHs as needed to an MS based on the MS multislot capability. This is done because the BSC cannot predict the PS service throughput. If the average number of MSs using the services carried on a PDCH exceeds a specified threshold, the BSC triggers excessive dynamic PDCH conversions. Currently, P2P services account for a small portion of GSM services. Such services have a large throughput, but the spectral efficiency of GSM networks is limited. Therefore, the P2P services are not recommended for GSM networks. This feature is implemented as follows: 1.


2.

The BSC identifies P2P services from various PS services.

3.

The BSC supports the setting of the following parameters for P2P services:

4.

−

Maximum Number of PDCHs for P2P ARP1

−


−


−

P2P ARP1 Scheduling Weight

−


−


−

P2P PDCH Multiplexing Weight

−

P2P Downlink TBF Release Delay

The BSC allocates radio resources to P2P services during peak hours based on the maximum number of configured PDCHs, priority weight, PDCH multiplexing weight, and delay for releasing downlink TBFs.

Enhancement None


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The NIUa board is required. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs None

3.2 Smartphone Solution 3.2.1 GBFD-511501 Multiple CCCHs Availability This feature was introduced in GBSS9.0.

Summary Based on configuration of BCCH TRX timeslot 0 as the BCCH physical channel, the Multiple CCCHs feature supports also configuring timeslots 2, 4, and 6 as the BCCH physical channel. This increases the CCCH capacity within a cell, which improves the paging and random access capability of the cell.

Benefits The Multiple CCCHs feature increases the number of CCCHs in a cell, improving the paging and random access capability of the cell.

Description In GSM networks, BCCH physical channels are divided into the following several types of logical channels: 

Downlink: FCCH, SCH, BCCH, PCH, AGCH, NCH



Uplink: RACH

Of these, the PCH, AGCH, NCH, and RACH are referred to as CCCHs. One cell is normally configured with a single BCCH physical channel and the BCCH TRX timeslot 0 is configured as the BCCH physical channel. This Multiple CCCHs feature supports configuring timeslots 2, 4, and 6 of the BCCH TRX as the BCCH physical channel. These BCCH physical channels do not include downlink FCCH, SCH, or NCH. They do include the downlink BCCH, PCH, and AGCH as well as the uplink RACH. The contents sent over timeslots 0, 2, 4, and 6 BCCH logical channels are identical; however, the PCH, AGCH, and RACH channels are able to send different contents. Consequently, configuring multiple BCCH physical channels increases the CCCH capacity.

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The BSC broadcasts the configured number of CCCHs to the MS in system information type 3 messages. The MS determines which timeslot to monitor for call information based on its own IMSI. Because BCCH physical uplink channels are all RACH channels, configuration of multiple CCCHs increases the number of RACH channels within the cell. As a result, the Multiple CCCHs feature also increases the random access capability of the cell.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware None Dependency on other GBSS functions None Dependency on other NEs None

3.2.2 GBFD-511502 Layered Paging Availability This feature was introduced in GBSS13.0.

Summary For the first paging, the BSC sends paging messages to the last cell on which the MS camps and to its neighboring cells. If the first paging fails, the BSC sends paging messages to the areas specified by the SGSN for the second paging.

Benefits This feature narrows down the paging areas for packet switched (PS) services. This helps lighten the CCCH load of the GSM network.

Description With the rapid development of PS services in recent years, PS paging messages have accounted for an increasingly larger proportion of paging messages than circuit switched (CS) paging messages. This leads to heavy traffic load on the CCCHs and reduces the success rate of CS service admission. PS paging messages are sent on the basis of routing areas (RAs). In live networks, however, users processing packet services do not cross a large area. In this case, paging resources are wasted. To save paging resources, Huawei introduces the Layered Paging feature. This feature Issue V0.5 (2011-08-30)


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enables the BSC to send paging messages to the last cell that an active PS MS camps on and to its neighboring cells. The BSC initiates the second paging by RAs if the first paging fails. PS paging does not affect the user experience even though they may be delayed for a certain period. Figure 3-1 Layered paging

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware None Dependency on other GBSS functions None Dependency on other NEs None

3.2.3 GBFD-511503 Dynamic Multiple CCCH Availability This feature is introduced in GBSS14.0.

Summary When the CCCH load is high, the TCHs on timeslot 2, 4, and 6 on the BCCH TRX are dynamically converted to CCCHs to extend the Um interface capability and relieve the load on CCCHs. When the CCCH load is low, the CCCHs on timeslot 2, 4, 6 are dynamically converted to TCHs to increase the channel usage.

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Benefits This feature is different from the static multiple CCCH function because it solves the problem of the increase in sudden pagings, which improves the manual O&M efficiency and increases the channel usage.

Description The paging success rate decreases greatly during holidays and due to emergencies. When the static multiple CCCH function is enabled, it is difficult to determine the number of static CCCHs to be configured. If the number of configured static CCCHs is small, the paging success rate remains low. If the number of configured static CCCHs is large, some TCHs are wasted. After the Dynamic Multiple CCCH feature is enabled, the BTS calculates the CCCH load and determines whether to increase or decrease the number of CCCHs based on a specified threshold. Then the BTS requests the BSC to increase or decrease one CCCH at a time. After the increase or decrease, the BSC delivers a system information message containing related configuration data to an MS so that the MS listens to the timeslot carrying the allocated CCCH. Figure 3-2 Dynamic Multiple CCCH CCCH configuration

CCCH traffic increases

CCCH traffic decreases CCCH

TCH

Enhancement None


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4

Green

4.1 Power Consumption Saving 4.1.1 GBFD-117601 HUAWEI III Power Control Algorithm Availability This feature was introduced in GBSS7.0.

Summary This feature enhances and optimizes the GBFD-110703 Enhanced Power Control Algorithm feature in terms of the filtering algorithm, interpolation of the measurement report, power control decision algorithm, and flexibility of threshold configuration.


Improves the efficiency and accuracy of power control.



Reduces the intra-network interference and the power consumption of the MS and BTS.



Increases the network capacity.



Improves the network performance.

Description Power control is an important method for radio link control. Based on the expected values set for parameters and the MRs on the uplink/downlink receive level and receive quality sent by the BTS, the BSC determines whether to adjust the transmit power of the MS and the BTS. Power control on the radio link is aimed at reducing the transmit power while maintaining the transmission quality. The HUAWEI III Power Control Algorithm feature enhances and optimizes the GBFD-110703 Enhanced Power Control Algorithm feature in terms of the filtering algorithm,

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interpolation of the measurement report, power control decision algorithm, and flexibility of threshold configuration. 

Optimizing the filtering/interpolation of the MR With this feature introduced, the incorrect MRs obtained at the initial stage of channel access do not affect the power control algorithm and therefore the change in trend of the transmit power of the MS can be predicted based on the MRs in a more timely and correct manner.



Optimizing the decision algorithm Based on the filtered receive level and receive quality, this algorithm considers the gain of the radio channel from frequency hopping, improving the accuracy of decisions.



Setting the power control threshold according to the service type This algorithm sets different power control thresholds for AMRFR services, AMRHR services, FR services, and HR services to optimize the power control on the AMR.

Enhancement GBSS8.1 Support implementing with "GBFD-110802 Pre-processing of Measurement Report."

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It is recommended working with the following features: GBFD-118103 Network Support SAIC Dependency on other NEs None

4.1.2 GBFD-117602 Active Power Control Availability This feature was introduced in GBSS8.1.

Summary With this feature, the uplink power and the downlink power are calculated immediately after an MS successfully accesses the network or an intra-BSC handover is successfully performed. Then, the network informs the MS of the calculation result of the uplink power. The BTS and the MS transmit signals at proper power. Therefore, power control is performed immediately.

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Benefits Through the power control of both the BTS and the MS, the system interference is reduced and the service quality is improved. In addition, as the power consumption of the BTS and MS is reduced, energy is saved, and the service time of the MS is prolonged.

Description With this feature, the uplink power and the downlink power are calculated immediately after an MS successfully accesses the network or an intra-BSC handover is successfully performed. Then, the network informs the MS of the calculation result of the uplink power. The BTS and the MS transmit signals at proper power. Therefore, power control is performed immediately. 

Active power control during MS access When an MS accesses the network, the following power control procedures are performed:



−

Calculation of the path loss: According to 3GPP TS 45.005, the path loss of the MS is obtained on the basis of the transmit power used by the MS when the MS accesses the network, and the uplink signal strength measured by the BTS.

−

Calculation of the transmit power: The transmit power of the MS and the BTS is obtained on the basis of the path loss of the MS and the expected signal strength in the uplink and downlink.

−

Execution of power control: When the TCH request is successful or when the MS accesses the network, power control is performed immediately. This enables the BTS and the MS to immediately transmit signals at proper power.

Active power control during intra-BSC handover During the intra-BSC handover, the path loss of the MS is obtained on the basis of the BCCH signal strength of the target cell recorded by the source cell before the handover and the transmit power of the BCCH TRX of the target cell. The calculation of the transmit power and the execution of power control procedures are the same as those of active power control during MS access.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It depends on the following features: GBFD-117601 HUAWEI III Power Control Algorithm Dependency on other NEs None

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4.1.3 GBFD-118103 Network Support SAIC Availability This feature was introduced in GBSS8.1.

Summary The network side performs active power control for the MS supporting single antenna interference cancellation (SAIC).

Benefits In the GSM network, the MS can use only a single antenna because of the limitations in size and cost. Therefore, the co-channel interference cannot be effectively suppressed and the spectral efficiency of the GSM system is reduced. Some attributes of interference are known, for example, channel modulation type and training sequence. Therefore, it is possible to improve the anti-interference capability of the receiver. The anti-interference technology called SAIC is defined in the 3GPP R6 protocol for the MS with a single antenna. SAIC can enhance the anti-interference capability of the downlink, increasing the capacity of the GSM system. With this feature, the network side performs active power control on the MS supporting SAIC to reduce the interference of the entire network, expand the system capacity, reduce the transmit power of the BTS, and save the power consumption.

Description SAIC is an anti-interference technology for suppressing the co-channel interference and adjacent-channel interference. The SAIC feature applies mainly to the MS with a single antenna and is used to reduce the impact of the interference reception of downlink signals through a signal processing technology. Compared with common mobile phones, the MS supporting SAIC has stronger anti-interference capacity. The network can modify the power control policy as required to reduce the transmit power of the BTSs, reducing the interference in the entire network. In downlink power control, the network checks whether the MS supports the SAIC. If the MS supports the SAIC, the network decreases the upper downlink level threshold and the lower downlink level threshold according to the Huawei III power control algorithm; the network increases the UL Qual.Upper Threshold and UL Qual.Lower Threshold, according to the Huawei II power control algorithm.

Enhancement None


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It depends on the following features: GBFD-117601 HUAWEI III Power Control Algorithm Dependency on other NEs The MS must support this feature.

4.1.4 GBFD-114801 Discontinuous Transmission (DTX)-Downlink Availability This feature was introduced in GBSS6.1.

Summary The Discontinuous Transmission (DTX)-Downlink feature can reduce the power consumption of the BTS and the frequency interference on the Um interface.


This feature reduces the power consumption of the BTS and intra-system interference.



From the perspective of the entire network, this feature reduces the frequency interference, increasing the network capacity.

Description DTX consists of Voice Activity Detection (VAD) and Silence Descriptor (SID). In addition, the GBSS automatically generates the comfortable noise to ensure the continuity of services. 

VAD When the Transcoder & Rate Adaptation Unit (TRAU) detests through the VAD module that the data received from the MSC contains no voice information, it clears the voice flag bit in the encoded TRAU frame. After identifying the flag bit, the BTS disconnects the downlink until the flag is reset.



SID The noise coding procedure is the same as the voice signal coding procedure. The SID frame also experiences the channel coding, interleaving, ciphering, and modulating and then is turned into the field containing the noise messages and sent out in eight continuous bursts.



Comfortable noise When receiving the uplink frames, the TRAU also judges the SID flag. If the SID is set, the MS is in the intermittent period. To make subscribers feel that the GSM provides services continuously, the TRAU inserts comfortable noise in the uplink.

With this feature, the TRAU can reduce the power consumption of the BTS, frequency interference on the Um interface. In downlink DTX mode, the GBSS equipment makes subscribers feel that the communication is continuous by providing the MSs with comfortable noise.

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Enhancement GBSS8.1 Configuring the DTX according to the voice coding: DTXs for different voice coding can be configured separately. That is, you can enable the DTX for the FR (including FR, EFR, and AMR) voice coding and the DTX for HR (including HR and AMR HR) voice coding simultaneously, and you can also enable FR DTX or HR DTX separately. The flexible configuration helps reduce the intra-network interference while maintaining the voice quality.


4.1.5 GBFD-114803 Discontinuous Transmission (DTX)-Uplink Availability This feature was introduced in GBSS6.1.

Summary If the encoder of the MS detects through the VAD module that the received voice signal is environment noise only, the MS periodically sends the SID, and then the TRAU restores the comfortable noise accordingly.


This feature greatly reduces the power consumption of the MS and prolongs the standby time of the MS.



From the perspective of the entire network, this feature reduces the frequency interference, increasing the network capacity.

Description The uplink DTX can reduce the transmit power of the MS and the co-channel interference on the Um interface.

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DTX consists of VAD and SID. In addition, the GBSS automatically generates the comfortable noise to ensure the continuity of services. 

VAD In uplink DTX mode, if the encoder of the MS detects through the VAD module that the received signal is environment noise only, the MS periodically sends the SID. When receiving the uplink frames, the TRAU also judges the SID flag. If the SID flag is set, the MS is in intermittent period. In this case, the TRAU restores the comfortable noise on the uplink to make subscribers feel that the communication is continuous.



SID The noise coding procedure is the same as the voice signal coding procedure. The SID frame also experiences the channel coding, interleaving, ciphering, and modulating and then is turned into the field containing the noise messages and sent out in eight continuous bursts.



Comfortable noise When receiving the uplink frames, the TRAU also judges the SID flag. If the SID is set, the MS is in the intermittent period. To make subscribers feel that the GSM provides continuous services, the TRAU inserts comfortable noise on the uplink.

The uplink DTX can reduce the transmit power of the MS, the co-channel interference on the Um interface and the power consumption of the MS, and prolong the call duration and standby time of the MS. In uplink DTX mode, the GBSS equipment makes subscribers feel that the communication is continuous by providing the MSs with comfortable noise.

Enhancement GBSS8.1 Configuring the DTX independently according to the voice coding: DTXs for different voice coding can be configured separately. That is, you can enable the DTX for the FR (including FR, EFR, and AMR) voice coding and the DTX for HR (including HR and AMR HR) voice coding simultaneously, and you can also enable FR DTX or HR DTX separately. The flexible configuration helps reduce the intra-network interference while maintaining the voice quality.


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4.1.6 GBFD-111602 TRX Power Amplifier Intelligent Shutdown Availability This feature was introduced in GBSS7.0.

Summary In the existing network, the cells are not busy all the time. When some cells are idle, some TRXs can meet the current traffic requirements. In this case, you can disable the idle TRXs to reduce the BTS power consumption and the operational expenditure of operators.

Benefits This feature helps reduce the BTS power consumption and therefore greatly reduces the operational expenditure. The power consumption of TRXs constitutes a major part of the power consumption of BTSs. In the existing network, however, the TRXs are not always working. With this feature, the power amplifiers of some idle TRXs are shut down to reduce the power consumption of the BTS and power costs of operators.

Description The TRX Power Amplifier Intelligent Shutdown feature can be enabled in a specific period. Idle TRXs can be shut down based on the prediction of traffic load and traffic volume to save energy. Alternatively, the power amplifiers of the disabled TRXs can be switched on to ensure that these TRXs are available for use at any time. Before shutting down a TRX, the BSC initiates an intra-cell handover for the calls on the TRX and then instructs the BTS to shut down the TRX when there is no call on the TRX. If some calls on the TRX cannot be handed over to other TRXs, the BSC does not instruct the BTS to shut down the TRX. Generally, the channel allocation optimization measure is used together with this feature. That is, channels are allocated to some centralized TRXs during the channel allocation. The channels on the BCCH TRX are preferentially allocated to reduce the channel usage on the non-BCCH TRX, reducing the power consumption of the BTS. In addition, the BTS allocates channels based on the priorities of TRXs. That is, the channels are preferentially allocated to TRXs with high priorities. In this way, the BSC centralizes busy channels on a few TRXs so that as many idle TRXs as possible can be shut down.

Enhancement None


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This feature cannot be used with the following features: GBFD-113701 Frequency Hopping (baseband hopping) when a frequency hopping group is involved in baseband hopping GBFD-113701 Frequency Hopping (RF hopping) when inter-module RF hopping is applied GBFD-510104 Multi-site Cell GBFD-113703 Antenna Frequency Hopping(in only GBSS9.0 and former version) GBFD-118106 Dynamic Power Sharing Dependency on other NEs None

4.1.7 GBFD-111603 TRX Power Amplifier Intelligent Shutdown on Timeslot Level Availability This feature was introduced in GBSS8.0.

Summary The power amplifier consumption constitutes a major part of the TRX power consumption, which constitutes a major part of the BTS power consumption. The TRX Power Amplifier Intelligent Shutdown on Timeslot Level feature reduces the static power consumption by controlling the power amplifier on timeslot level to make the idle timeslots consume no power.

Benefits This feature helps reduce the power consumption of the BTS and therefore greatly reduces the operational expenditure. The power amplifier consumption constitutes a major part of the TRX power consumption, which constitutes a major part of the BTS power consumption. In the existing network, however, not all the timeslots are always working. With this feature, the power amplifiers consume no power when the timeslots are idle, greatly reducing the power costs of operators.

Description The power amplifier is an important device used for transmitting power to the antenna system. The power consumption of the power amplifier consists of static power consumption and dynamic power consumption. The linear-shaped power amplifier requires a constant offset voltage to enable power transmission at any time even when it does not transmit power. The power consumption corresponding to the fixed offset voltage is called static power consumption. The dynamic power consumption, however, refers to the power consumption produced only when the power amplifier is processing services. The dynamic power consumption increases with the output power of the TRX. When the power amplifier does not process services, the dynamic power consumption is zero. In the industry, the static power amplifier can be shut down only when all the TRXs process no service. When the dynamic power consumption is zero, the power amplifier is shut down. Therefore, the total power consumption of the power amplifier is zero.

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Enhancement None


4.1.8 GBFD-111604 Intelligent Combiner Bypass Availability This feature was introduced in GBSS8.1.

Summary With this feature, the original TRX with high output power is replaced by two TRXs with lower output power to reduce the power consumption of BCCH TRX while maintaining the network capacity in low traffic periods. Therefore, this feature saves power for the BTS.

Benefits This feature helps reduce the BTS power consumption and therefore greatly reduces the operational expenditure. The power consumption of TRXs constitutes a major part of the power consumption of BTSs. In the existing network, however, the TRXs are not always working. In low traffic periods, this feature can change the working status of TRXs to further reduce the power consumption without interfering with the coverage and therefore bring benefits to operators.

Description The ICB applies to the DTRU only. The ICB can be enabled only when all the non-BCCH carriers are idle, some channels on the BCCH carrier are idle in the cell, and the DTRU on the BCCH applies the combination mode with physical connection. For example, the ICB can be enabled in an S4 cell with single antenna, two DTRUs, and BCCH TRX in combination mode. For an S4 cell, the output power of TRXs should be 30 W for the coverage requirement. In normal cases, the TRX transmits at a high power of 60 W. After the combination mode is applied, the output power is 30 W, which still meets the coverage requirement. In the existing network, the traffic is low in some periods. When the timeslots on the BCCH carrier are idle, the output power of the BCCH TRX is reduced to 15 W and the PBT mode is applied to

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ensure that the combined output power retains 30 W. In this way, the TRX power is reduced from 60 W to 15 W while maintaining the network capacity. This greatly reduces the energy consumption of the TRX and therefore reduces the power consumption of the BTS.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. The ICB can be enabled only when all the non-BCCH TRXs are idle and some channels on the BCCH carrier are idle in the cell. The ICB applies only to the DTRU in combination mode. This feature is supported by the optimized DTRU, the DRRU, and the DRFU. The ICB cannot be enabled on the static PDCHs or on the PDCHs converted from the dynamic PDCHs (TCHs). When the output power of the TRX is 60 W and the static power level is 0 or 1, the ICB helps save the energy. When the output power of the TRX is 40 W and the static power level is 0, the ICB helps save the energy. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-113701 Frequency Hopping (baseband hopping) GBFD-113703 Antenna Frequency Hopping GBFD-510104 Multi-site Cell It depends on the following features: GBFD-111611 TRX Working Voltage Adjustment Dependency on other NEs None

4.1.9 GBFD-111605 Active Backup Power Control Availability This feature was introduced in GBSS8.1.

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Summary The Active Backup Power Control feature takes different measures to prolong the service time of the BTS in case of mains power cut due to power off, snow disaster, and earthquake, ensuring sufficient time for repairing the equipment and improving the network robustness.

Benefits When the external power supply of the BTS is interrupted, this feature provides various choices for operators to meet different requirements. For a configured BTS, the coverage preferred strategy ensures sufficient coverage, the capacity preferred strategy ensures high traffic capability, and the backup power time preferred strategy prolongs the service time and provides diverse services. This greatly improves the service quality for operators.

Description When the external power supply of the BTS is interrupted, a power-off alarm is generated on the BTS. The BTS then uses the batteries to supply power. To save the backup power, the BTS automatically shuts down some TRXs under the control of the timer and then gradually reduces the TRX transmit power with a certain step until the BTS is powered off. When the external power supply of the BTS recovers, the previously disabled TRXs are enabled and all TRXs transmit at the normal power. The Active Backup Power Control feature takes into account the coverage, capacity, and backup power time. Therefore, three modes can be configured: coverage preferred, capacity preferred, and backup power time preferred. 

Coverage preferred: Shut down some TRXs and then gradually reduce the transmit power of the remaining TRXs.



Capacity preferred: Gradually reduce the transmit power of all TRXs and then shut down some TRXs.



Backup power time preferred: Shut down some TRXs and at the same time reduce the transmit power of the remaining TRXs.

This feature reduces the coverage of a cell gradually and therefore the MSs at the edge of the cell are gradually handed over to the neighboring cells. Therefore, this feature has no negative impact on the network performance.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs

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Huawei power backup device is required, such as APM30.

4.1.10 GBFD-111606 Power Optimization Based on Channel Type Availability This feature was introduced in GBSS8.1.

Summary Huawei GBTS equipment supports two modulation modes: 8PSK and GMSK. The working voltage of the power amplifier varies with the modulation modes. When the 8PSK modulation mode is changed to GMSK, the Power Optimization Based on Channel Type feature accordingly adjusts the working voltage of the power amplifier to reduce the power consumption of the TRX.

Benefits This feature adjusts the working voltage of the power amplifier based on the working mode of MSs. The flexible adjustment of the working mode ensures that the BTS always works in optimal state while maintaining the service quality. This minimizes the power consumption and saves the power.

Description The Power Optimization Based on Channel Type feature involves two functions: dynamic voltage adjustment and dynamic PDCH voltage adjustment. The dynamic voltage adjustment provides different working voltages for the power amplifier based on the modulation mode. If all channels on the TRX are configured as TCHs, the TRX works in GMSK mode and the BTS provides the TRX with the working voltage required in GMSK mode. If some channels on the TRX are configured as dynamic or static PDCHs, the TRX works in 8PSK mode and the BTS provides the TRX with the working voltage required in 8PSK mode. In this way, the feature reduces the power consumption. As the GPRS traffic increases, an increasing number of dynamic PDCHs are configured on the TRX. When no data service is processed and a great number of speech services are processed on a TRX, the dynamic PDCHs are converted into TCHs to provide speech services. According to the dynamic voltage adjustment function, the 8PSK mode is adopted on the TRX because the TRX is configured with dynamic PDCHs. In this way, the voltage is adjusted to a very high value, increasing the power consumption. The dynamic PDCH voltage adjustment function, however, can detect the channel status on the TRX. When all dynamic PDCHs are converted into TCHs, the voltage adjustment function is enabled to provide the working voltage required in GMSK mode. If the TCHs are converted back into PDCHs, the working voltage required in 8PSK is applied again.

Enhancement None

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None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-113701 Frequency Hopping (baseband hopping) GBFD-113703 Antenna Frequency Hopping GBFD-510104 Multi-site Cell It depends on the following features: GBFD-111611 TRX Working Voltage Adjustment Dependency on other NEs None

4.1.11 GBFD-111608 PSU Smart Control Availability This feature was introduced in GBSS8.1.

Summary The PSU Smart Control feature switches on the required PSUs and shuts down the redundant PSUs based on the required power consumption of the BTS. This improves the efficiency of the power system and prolongs the service time of the power system.

Benefits When the load is not heavy, the power system works with low efficiency, reducing the service time of the power conversion modules. This feature flexibly adjusts the power supply capability as required by controlling the number of working PSUs in real time. This avoids the case that the power conversion equipment works under light load and prolongs the working time of the equipment, reducing the costs of operation and maintenance.

Description In certain BTS application scenarios, when the external power supply cannot provide the working voltage of –48 V DC required by the BTS, the BTS power system should be added to perform the power conversion such as conversion from 220 V AC to –48 V DC. The power system consists of the PMU and PSUs. The PMU is responsible for the management of the PSUs and the communication between the PSUs and the BTS. The PSUs are responsible for power conversion. In Huawei system, the PSUs are configured in N+1 mode according to the possible maximum power consumption of the BTS. Generally, the power consumption of the BTS is lower than its possible maximum power consumption. Therefore, the PSUs are usually in light load state. This results in low efficiency of power conversion and shortens the service time of PSUs.

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The PSU Smart Control feature switches on the required PSUs and shuts down the redundant PSUs based on the required power consumption of the BTS. This improves the efficiency of the power system and prolongs the service time of the power system. For MBTS scenario, because MBTS of GSM, UMTS and LTE are sharing one PMU, only one license of GSM, UMTS and LTE is required for MBTS, but if the corresponding network is down, this function will be deactivated for MBTS.

Enhancement None


4.1.12 GBFD-111609 Enhanced BCCH Power Consumption Optimization Availability This feature was introduced in GBSS8.1.

Summary The Enhanced BCCH Power Consumption feature reduces the power consumption of the BTS by reducing the transmit power of the non-BCCH timeslots on the BCCH TRX.

Benefits The overall power consumption of the BTS is a major concern for operators. This feature provides the following benefits: 

This feature reduces the overall power consumption of the BTS and therefore saves the power cost of operators.



This feature reduces the intra-network interference by reducing the transmit power to enable the tighter frequency reuse.

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Description When the non-BCCH timeslots on the BCCH TRX are idle, this feature supports the configuration of the transmit power of these timeslots. When the non-BCCH timeslots on the BCCH TRX are occupied, this feature supports the power control on these timeslots. The power control range can be configured on the Local Maintenance Terminal.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs This feature may affect the accuracy of measuring neighboring cells by the MS. Therefore, it is recommended that this feature be enabled during low traffic hours at night.

4.1.13 GBFD-111610 Dynamic Cell Power Off Availability This feature was introduced in GBSS9.0.

Summary The Dynamic Cell Power Off feature is used generally in a 900 MHz/1800 MHz dual-band network. In a specified period, if the traffic is low and a 900 MHz cell can carry all the traffic in the coverage area of an 1800 MHz cell, then the 1800 MHz cell can be powered off to reduce the power consumption of the BTS.

Benefits By powering off the idle network devices in low traffic hours, the consumption of resources can be reduced. This also reduces the operational expenditure of the operators.

Description The Dynamic Cell Power Off feature means that within a specified period, the cells in the 900 MHz/1800 MHz dual-band network are dynamically powered off on the basis of the network traffic load. 900 MHz cells refer to the cells working on the 900 MHz or 850 MHz frequency Issue V0.5 (2011-08-30)


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band, and 1800 MHz cells refer to the cells working on the 1800 MHz or 1900 MHz frequency band. If the coverage area of an 1800 MHz cell is within the coverage area of a 900 MHz cell and no blind zone exists, then the 900 MHz cell is referred to as the same-coverage cell of the 1800 MHz cell. Only 1800 MHz cell with same-coverage cells can be powered off. When a cell meets the condition of dynamic cell power-off, the BSC hands over the MSs with ongoing services to other cells. After the same-coverage cell is powered off, the BSC periodically detects the load in the cell. When the load in the cell is constantly higher than the cell load threshold, the cell is powered on again. Cells are powered off dynamically based on cell configurations. Because dynamic cell power-off affects network capacity, cells should be powered off only in specified periods of low traffic, such as 00:00 to 6:00 in the morning. Cells cannot be powered off in other periods so that the traffic absorption requirement is met.

High Traffic

Low Traffic

Cell_A 900M

Cell_A 900M

Cell_B closed

Cell_B 1800M

MS_A MS_C

MS_B

MS_B

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It is recommended working with the following features: GBFD-114402 Enhanced Dual-band Network It is mutually exclusive with the following features: GBFD-118106 Dynamic Power Sharing (Dual PA power sharing) Dependency on other NEs

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None

4.1.14 GBFD-111611 TRX Working Voltage Adjustment Availability This feature was introduced in GBSS7.0.

Summary The TRX power consumption accounts for a large proportion of the BTS power consumption. The working voltage of the TRX is a major factor that affects the TRX power consumption. Hence, to lower the TRX power consumption, the TRX should work under a suitable voltage to ensure an efficient output power.

Benefits Reduction in the TRX power consumption plays a key role in saving energy in a BTS system because the TRX power consumption accounts for a large proportion of the BTS power consumption. When the function of "TRX Working Voltage Adjustment" is enabled, the efficiency of the output power of the TRX can be maintained, which helps reduce the investment in power made by network operators on the base station equipment.

Description The working voltage of the TRX is always set to a high level to ensure the maximum output power of the TRX. In actual application, however, the maximum output power of the TRX is not always required. In this case, if the TRX still works under such a high voltage, extra power is consumed because a lower working voltage can also provide the required output power. To reduce the power consumption of the TRX, Huawei developed the function of "TRX Working Voltage Adjustment" that enables the intelligent adjustment of the TRX working voltage according to the output power. For example, in the DTRU that works under different output powers of 40 W and 60 W, this function supports the intelligent adjustment. In addition, this function supports the intelligent adjustment of the Power Amplifier (PA) working voltage based on different power levels to reduce the TRX power consumption.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS functions None Dependency on other NEs

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None

4.1.15 GBFD-111612 Multi-Carrier Intelligent Voltage Regulation Availability This feature was introduced in GBSS8.1.

Summary With this feature, the working voltage of the power amplifier of the multi-transceiver module can be timely adjusted on the basis of its output power. This improves the working efficiency of the power amplifier and reduces the power consumption of the BTS.

Benefits With the advanced design structure applied, the multi-transceiver RF module of the 3900 series base station provides the operators with the benefits such as simplified configuration, small space, and easy capacity expansion. When this feature is enabled, the multi-transceiver RF module of the 3900 series base station can properly configure the working status of the power amplifier and reduce the operation expenditure for operators without affecting the network coverage.

Description The power consumption of the TRX is a major part of the power consumption of the BTS. The power consumption of the TRX is related to factors such as the number of actually working TRXs, the traffic volume, output power, and working mode. All the carriers in the multi-transceiver module share one power amplifier. When many MSs access the same carrier, the output power of the carrier varies with the distance between the MS and the BTS. From the perspective of the total output power of the multi-transceiver module, in most cases, the output power is lower than the maximum output power of the power amplifier. The power amplifier works most efficiently when it transmits at the maximum power. The reduction of the output power affects the efficiency to some extent. The flexible adjustment of working voltage of the power amplifier helps improve the working efficiency of the power amplifier. This feature monitors the output power of all the carriers within the module. When the total output power of the power amplifier reduces after the measurement for a period, this feature adjusts the working voltage of the power amplifier to a smaller value according to the related algorithm. In this way, the power amplifier works with great efficiency after the output power reduces, reducing the power consumption of the TRX.

Enhancement None


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Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other functions of the GBSS It is mutually exclusive with the following features: GBFD-510104 Multi-site Cell Dependency on other NEs None

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Topology&Transmission

5.1 Transmission Efficiency 5.1.1 GBFD-116701 16Kbit RSL and OML on Abis Interface Availability This feature was introduced in GBSS7.0.

Summary With this feature, each signaling link occupies only 16 kbit/s bandwidth at the physical layer, saving the transmission resources on the Abis interface.


When the capacity of the BTS is small, such as O1 or O2, this feature can minimize the transmission resources required on the Abis interface.



The lease cost for the satellite transmission resources is very high. This feature can save bandwidth, and therefore it can be used when satellite transmission is used.

Description With this feature, the RSL or OML occupies 16 kbit/s sub-timeslots. In this case, the signaling and service can be configured in a 64 kbit/s timeslot on the Abis interface, and the signaling of different BTSs can coexist in the same 64 kbit/s timeslot. Compared with the traditional 4:1 multiplexing technology, the 16 kbit/s LAPD signaling link mode can reduce the timeslot fragments, reducing the rent in the network with expensive transmission cost such as the satellite transmission networking. The bandwidth of each signaling link is limited to 16 kbit/s. Therefore, for the cell with high traffic volume, the call access failure or call drops may occur because of signaling link congestion.


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Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other NEs None Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-116601 Abis Bypass GBFD-117801 Ring Topology GBFD-117301 Flex Abis GBFD-118601 Abis over IP GBFD-118611 Abis IP over E1/T1

5.1.2 GBFD-117301 Flex Abis Availability This feature was introduced in GBSS7.0.

Summary With this feature, the Abis transmission resources can be dynamically allocated to MSs.

Benefits Flex Abis enables the sharing of the Abis interface transmission resources among different BTSs, cells, and services, improving the resource utilization. Especially for BTSs of large capacity with multiple cells, cascaded BTSs, and the cells configured with the EDGE, this feature can greatly improve resource utilization.

Description In the CS domain, the timeslot transmission on the Abis interface adopts the resource pool mode. The Abis resource is allocated to a TRX only when the TRX is busy. This can improve the utilization of Abis resources. In the PS domain, the transmission resources on the Abis interface are allocated based on 16 kbit/s sub-timeslot. A main timeslot is allocated to the PDCH, and then additional timeslots are allocated with the steps of 16 kbit/s based on the required coding rate on the Um interface. Huawei adopts 16 kbit/s as the unit so that bandwidth usage is greatly improved and bandwidth is saved as much as possible.

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The synchronization timeslot, signaling link timeslot, OML timeslot, and PS idle timeslot still adopt the fixed Abis allocation mode. Other Abis timeslots adopt the Abis pool mode. Huawei BSS equipment also supports the allocation of half-rate channels on the Abis interface, which is triggered on the basis of the load of the Abis resources. Abis timeslots are allocated at a minimum rate of 8 kbit/s. When the resource usage on the Um interface does not reach the congestion threshold but the transmission resource utilization has reached the congestion threshold, 8 kbit/s half-rate channels on the Abis interface are allocated to improve the utilization of Abis resources.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It is mutually exclusive with the following features: GBFD-116701 16Kbit RSL and OML on Abis Interface GBFD-118601 Abis over IP GBFD-118611 Abis IP over E1/T1 GBFD-118401 Abis Transmission Optimization GBFD-117801 Ring Topology GBFD-116601 Abis Bypass Dependency on other NEs This feature cannot be used together with DXX.

5.1.3 GBFD-117702 BTS Local Switch Availability This feature was introduced in GBSS7.0.

Summary BTS Local Switch enables the BSC to perform speech loopbacks for a call within the BTS coverage if the calling and called MSs are under the same BTS or the same group of BTSs.

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Benefits BTS Local Switch saves transmission resources over the Abis, Ater (only in A over TDM mode), or A (only in A over IP mode) interface. The actual transmission network determines the interface over which transmission resources are saved. In Abis over satellite mode, this feature reduces the delay for transmitting voice data and improves user experience.

Description BTS Local Switch consists of the following functions: intra-BTS local switching (single-site local switching) and inter-BTS local switching (inter-site local switching). Intra-BTS local switching refers to the local switching for the calling and called MSs that are under the same BTS. Voice data for a call is looped back within a BTS without being transmitted over the Abis interface. When inter-BTS local switching is enabled in Abis over TDM mode, the BSC performs speech loopbacks within a BTS group for the calling and called MSs under a group of BTSs cascaded in chain or tree topology. When inter-BTS local switching is enabled in Abis over IP mode, the BSC transmits voice data between two BTSs for the calling and called MSs under a group of BTSs to which IP routes are reachable. After a call is established, the BSC performs a local switching if it detects that the calling and called MSs are located in the same BTS or in the coverage of a group of cascaded BTSs and the requirements for the local switching are met. Before performing the loopback for the local switching, if the speech coding schemes of the two MSs are different, the BSC adjusts the two speech coding schemes to the same scheme by enabling the two MSs to adopt the lowest speech coding capability. In this way, the speech coding schemes and the speech coding rates of the two MSs are consistent. Figure 5-1 shows the circuit usage after BTS Local Switch is enabled. The system performs speech loopbacks for both the calling and called MSs on the BTS side, and then releases the timeslots used on the Abis and Ater interfaces. Figure 5-1 BTS Local Switch Um

MS a

Abis

BTS 2 BSC

BTS

TC Core Network

1 MS b

A

Ater

BTS 3 Transfer channel loop

Transfer channel released

Huawei BTS Local Switch can be started on the basis of the prefix number or the congestion conditions of the Abis resources or started unconditionally. For the BTS with special numbers, this feature is unavailable.

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If the CN equipment is not provided by Huawei, the following functions are unavailable after BTS Local Switch is enabled: lawful interception, MSC announcement, DTMF, fax during voice, and independent charging of BTS Local Switch. BTS Local Switch has an impact on the speech quality. The times of speech coding and decoding are reduced, enhancing the speech quality. In satellite transmission mode, there is no satellite transmission delay because the speech loopback is performed. Therefore, the speech quality is greatly improved. BTS Local Switch and BSC Local Switch can be enabled at the same time or independently.

Enhancement GBSS13.0 AMR Rate Adaptation under BTS Local Switch AMR rate adaptation can be used together with BTS Local Switch. Based on the AMR rate set and protocol-specified preferred rate set of both the calling and called MSs under a BTS, the BSC obtains a new rate adjustment threshold to select the best AMR coding scheme for both the calling and called MSs under BTS Local Switch. If the calling MS occupies an AMR TCHF and the called MS occupies an AMR TCHH, or vice versa, the MS that occupies AMR TCHH is switched to an AMR TCHF, and then the BSC adjusts the AMR codec rate of both MSs before BTS Local Switch is enabled.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Lawful interception is supported by BTS Local Switch in Abis IP over FE mode only when a UTRPc board is configured. Dependency on other GBSS features If the TDM transmission mode is used on the Abis interface, this feature depends on the GBFD-117301 Flex Abis feature. In Abis over IP mode, this feature depends on the GBFD-118601 Abis over IP and GBFD-118611 Abis IP over E1/T1 features. The following features are mutually exclusive: GBFD-118602 A over IP GBFD-118622 A IP over E1/T1 GBFD-118401 Abis Transmission Optimization GBFD-119301 Voice Fault Diagnosis GBFD-116601 Abis Bypass GBFD-115601 Automatic Level Control (ALC) GBFD-115602 Acoustic Echo Cancellation (AEC)

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GBFD-115603 Automatic Noise Restraint (ANR) GBFD-115701 TFO GBFD-115703 Automatic Noise Compensation (ANC) GBFD-115704 Enhancement Packet Loss Concealment (EPLC) GBFD-115711 EVAD GBFD-115506 AMR Coding Rate Threshold Adaptive Adjustment GBFD-119301 Voice Fault Diagnosis Dependency on other NEs This feature cannot be used together with DXX.

5.1.4 GBFD-118401 Abis Transmission Optimization Availability This feature was introduced in GBSS8.0.

Summary The Abis Transmission Optimization feature detects and compresses the idle voice frames by using VAD and then sends the compressed data packet on the HDLC transmission channels for statistical multiplexing. This improves the E1/T1 bandwidth usage. With this feature, each E1/T1 can support 24 or 18 TRXs under the following conditions. (The number of TRXs supported by E1 and T1 are different because the bandwidth of an E1 is 2 Mbit/s and the bandwidth of a T1 is 1.55 Mbit/s.) 

Full-rate CS services (excluding the half-rate and PS services)



Voice activation factor of 0.5.



Cascaded BTSs not carried on a single E1.

Benefits In the radio access network, the transmission cost accounts for 20% of the operators' expenditure, of which the transmission cost over the Abis interface makes up a large portion. Therefore, to effectively reduce the CAPEX and OPEX of the operators, it is necessary to introduce a technology that saves transmission resources while protecting the current investment. This feature can save the transmission resources of the Abis interface. By adding the BSC interface hardware and upgrading the BSC and BTS software, the operator can improve the utilization of Abis resources by 30% to 40%. Under certain conditions, one E1 can carry 24 TRXs.

Description The Abis Transmission Optimization feature introduces the HDLC frame and HDLC channel without changing the physical transmission mode. It statistically multiplexes the traffic data, signaling data, and OM data on the HDLC channel to obtain a higher transmission gain through voice frame compression and multiplexing.

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Figure 5-2 Abis transmission optimization-enabled networking

Different from the TDM resources, the HDLC resources can be shared by multiple MSs. Therefore, the QoS mechanism is introduced to add the admission control and congestion management after this feature is enabled. Admission control is a major measure taken to prevent congestion and is an important part of the entire QoS mechanism. The system determines the bandwidth required for the access of new services to prevent port or link congestion and to ensure the QoS of the entire system. Congestion management alleviates the congestion by using the mechanism of lowering the speech coding rate when transmission resources are congested, improving the processing capability of the entire system.

Enhancement GBSS8.1 The function of manually configuring the HDLC channel is introduced. GBSS8.1 The enhanced QoS is introduced.

Dependency Dependency on BSC hardware The BSC should be configured with the PEUa/POUc. If the BM/TC is separated, the DPUc should be configured in the subrack where the PEUa/POUc is located for processing the HDLC frame. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Issue V0.5 (2011-08-30)


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Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-117701 BSC Local Switch GBFD-116701 16Kbit RSL and OML on Abis Interface GBFD-117301 Flex Abis Dependency on other NEs None

5.1.5 GBFD-112013 Abis Congestion Trigger HR Distribution Availability This feature was introduced in GBSS8.1.

Summary The Abis Congestion Triggered HR Distribution feature provides the following strategies for alleviating the Abis congestion: preferentially allocating the TCHH, dynamic TCHF-TCHH conversion, and queuing/preemption. In this way, the system capacity and speech quality are dynamically balanced.


This feature saves the transmission resources of the Abis interface and reduces the network deployment cost.



When the transmission resources on the Abis interface are congested, this feature maintains the system capacity by degrading the speech quality. When the transmission resources are not congested, the speech quality recovers and therefore the system capacity and the speech quality are dynamically balanced.

Description When the Abis Congestion Triggered HR Distribution feature is enabled, the system triggers the HR allocation based on the congestion condition of transmission resources on the Abis interface. In peak hours, the transmission resources on the Abis interface are congested before these on the Um interface. Therefore, the original dynamic TCHF-TCHH conversion/preferentially allocating the TCHH based on the load of the Um resources cannot ensure the system capacity. This feature performs the dynamic TCHF-TCHH conversion, preferential allocation of TCHH, and queuing/preemption to alleviate the congestion of Abis resources and increase the system capacity. 

Dynamic TCHF-TCHH conversion When the transmission resources on the Abis interface are congested, the qualified calls, calls initiated by non-VIP subscribers, calls with high speech quality, and calls with allowed path loss, are handed over from TCHF to TCHH. This alleviates the congestion of transmission resources on the Abis interface and increases the system capacity. When the congestion of transmission resources on the Abis interface is eliminated, the qualified

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calls in the cell are handed over from TCHH to TCHF to improve the speech quality of calls. 

Preferentially allocating the TCHH When the transmission resources on the Abis interface are congested, the TCHHs are preferentially allocated to the newly accessed calls to slow down the congestion.



Queuing/Preemption Similar to the queuing/preemption mechanism for the Um interface, the queuing/preemption is performed for calls that allow queuing/preemption on assignment or incoming handover. This ensures that services can be provided for subscribers with high priorities even if the transmission resources on the Abis interface are severely congested.

If the TDM transmission is used on the Abis interface, preferentially allocating the TCHH mechanism is applied to eliminate the Abis congestion triggered by the GBFD-117301 Flex Abis feature. If the HDLC transmission is used on the Abis interface, preferentially allocating the TCHH mechanism and queuing/preemption mechanism are applied to eliminate the Abis congestion triggered by the GBFD-118401 Abis Transmission Optimization feature. If the IP transmission is used on the Abis interface, dynamic TCHF-TCHH conversion, preferentially allocating the TCHH, and queuing/preemption mechanisms are applied to eliminate the Abis congestion triggered by the GBFD-118601 Abis over IP feature. This feature can be used with AMR HR and normal HR.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on one of the following features: GBFD-118401 Abis Transmission Optimization GBFD-117301 Flex Abis GBFD-118601 Abis over IP GBFD-118611 Abis IP over E1/T1 Dependency on other NEs None

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5.1.6 GBFD-116901 Flex Ater Availability This feature was introduced in GBSS7.0.

Summary When the Flex Ater feature is enabled, the Ater resources are allocated according to the channel type during the call connection. If the TCHFs are allocated on the Um interface, the 16 kbit/s timeslots on the Ater interface are used. If the TCHHs are allocated on the Um interface, the 8 kbit/s timeslots on the Ater interface are used.

Benefits This feature effectively reduces the transmission investment on the Ater interface in remote TC networking. When the half rate accounts for 30% in the system, the Flex Ater-enabled network saves the Ater transmission resources by up to 15%, compared with the Flex Ater-disabled network.

16K TS

X% * 50%

8K TS

X% HR/AMR HR without Flex Ater

X% HR/AMR HR with Flex Ater

...

...

...

50%

100% HR/AMR HR with Flex Ater

Description The Ater interface is an internal interface between the GMPS/GEPS and the GTCS in the Huawei BSS equipment. With this feature, the Ater resources are classified into 16 kbit/s timeslots and 8 kbit/s timeslots. Issue V0.5 (2011-08-30)


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The Flex Ater feature allocates the Ater resources according to the channel type during the call connection. If the TCHFs are allocated on the Um interface, the 16 kbit/s timeslots are used. If the TCHHs are allocated on the Um interface, the 8 kbit/s timeslots are used. Therefore, the Ater resources are fully utilized. The user can determine the initial proportions of the 16 kbit/s timeslots and the 8 kbit/s timeslots based on the traffic module. If either type of resources is insufficient, the BSC dynamically adjusts the Ater resources. If the 16 kbit/s timeslots are insufficient, two continuous 8 kbit/s timeslots are incorporated into one 16 kbit/s timeslot. Similarly, if the 8 kbit/s timeslots are insufficient, one 16 kbit/s timeslot is divided into two 8 kbit/s timeslots. The adjustment process is recorded in the traffic statistics. In addition, the user can query through the LMT the number of the 16 kbit/s and 8 kbit/s timeslots of a specific subrack and the usage of these timeslots. Based on the query result, the user can determine whether the initial proportions of 16 kbit/s and 8 kbit/s timeslots are proper or the Ater resources are congested. When this feature is enabled and the transmission resources on the Ater interface are insufficient, the BSC preferentially allocates the half rate to alleviate the congestion, increasing the system capacity.

Enhancement None


5.1.7 GBFD-117701 BSC Local Switch Availability This feature was introduced in GBSS7.0.

Summary BSC Local Switch enables the BSC to perform speech loopbacks for a call within the BSC if the calling and called MSs are under the same BSC. This saves Ater transmission resources and TC resources (only in A over TDM mode).

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In A over TDM mode, 5% to 40% transmission resources over the Ater interface can be saved if a remote TC is configured.



If there is a large proportion of calls involved in local switching, costs on devices can be reduced by decreasing the number of TC resources.



In A over IP mode, 5% to 40% transmission bandwidth over the A interface can be saved.

The transmission bandwidth saving proportion varies with the traffic model used on the live network.

Description 

Overview of BSC Local Switch With this feature, if the calling and called MSs are under the same BSC, the speech signals on the Abis interface are looped back to the MS without traveling around the NSS. As shown in the following figure, BSC Local Switch saves transmission resources of segment C. Note that BSC Local Switch is performed on the BSC side without involving the NEs on the NSS side and the speech signals are not routed to the MSC. The transmission resources at the D and E segments of the MSC, however, are not released. In addition, in BSC Local Switch, the speech coding schemes of the calling and called MSs are the same and no coding conversion is required. Therefore, the TC resources involved in BSC Local Switch can be released, and the speech quality is improved.

Figure 5-3 BSC Local Switch

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BSC Local Switch based on the Ater transmission congestion BSC Local Switch involves the following modes: −

Unconditional BSC Local Switch

−

BSC Local Switch based on the Ater transmission congestion

−

BSC Local Switch based on the prefix number

With BSC Local Switch based on the Ater transmission congestion enabled, the BSC determines whether to perform the local switching based on the congestion of the Ater resources to alleviate the congestion. 

Speech version adjustment When enabling BSC Local Switch, ensure that the speech coding rates of the calling and called MSs are the same. If different speech coding rates are used, the BSC adjusts different rates to the same rate through a forced handover. If the adjustment fails because the calling and called MSs have no intersection of speech coding, BSC Local Switch should not be enabled.



Inter-MGW scenario

If the calling and called MSs are served by different MGWs, the MGWs convert the user plane protocol format. This results in the loss of the BSC identification information carried by the speech frame. Therefore, BSC Local Switch fails to be triggered. There are two inter-MGW scenarios: 1. In MSC pool networking mode, the calling and called MSs are served by different MGWs. 2. If the roaming and local MSs in a conversation are served by different MSCs, the CN regards that the two MSs are served by different MGWs even if the BSC is connected to only one MGW. In this case, BSC Local Switch fails to be triggered.

Enhancement GBSS8.0 The lawful interception should be supported by Huawei MSC. GBSS8.1 The supplementary services such as CW/HOLD/MPTY/ECT are supported. The announcement should be supported by Huawei MSC. The independent charging of local switching should be supported by Huawei MSC. That is, the operators can adopt flexible charging strategies. GBSS13.0 AMR Rate Adaptation under BSC Local Switch AMR rate adaptation can be used together with BSC Local Switch. Based on the AMR rate set and protocol-specified preferred rate set of both the calling and called MSs under different BTSs, the BSC obtains a new rate adjustment threshold to select the best AMR coding scheme for both the calling and called MSs under BSC Local Switch. If the calling MS occupies an AMR TCHF and the called MS occupies an AMR TCHH, or vice versa, the MS that occupies AMR TCHH is switched to an AMR TCHF, and then the BSC adjusts the AMR codec rate of both MSs before BSC Local Switch is enabled. In addition, this release supports BSC Local Switch in A over IP or Ater over IP mode. Support BSC Local Switch in Abis over IP mode Issue V0.5 (2011-08-30)


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When MO and MT are both located under same BSC, the calling voice is being looped back at Abis interface of BSC, without going through NSS side, directly through package switch to the called side. By using Abis IP method, BSC Local Switch can save 10% to 20% transmission resource in Ater interface, accordingly save operator’s OPEX.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features In Abis over TDM mode, BSC Local Switch in compliance is mutually exclusive with the following features: GBFD-118401 Abis Transmission Optimization GBFD-118601 Abis over IP GBFD-118611 Abis IP over E1/T1 GBFD-118602 A over IP GBFD-118622 A IP over E1/T1 GBFD-119301 Voice Fault Diagnosis GBFD-115506 AMR Coding Rate Threshold Adaptive Adjustment BSC Local Switch in Abis over IP mode can be used together with the following features: GBFD-118601 Abis over IP GBFD-118611 Abis IP over E1/T1 Dependency on other NEs None

5.1.8 GBFD-116902 Ater Compression Transmission Availability This feature was introduced in GBSS9.0.

Summary When TDM is applied over the Ater interface, the IP over PPP over STM-1 scheme can be used to carry traffic data. With the application of VAD, Ater MUX, PPP MUX, and IP header compression, the data transmitted over the Ater interface is compressed and the transmission efficiency over the IP interface is increased.

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Benefits This feature helps save the lease cost of the transmission equipment over the Ater interface. Compared with the traditional TDM transmission, the Ater compression transmission saves 30% of the transmission resources.

Description The BSC interworks with the remote TC subrack through the Ater interface. To save the transmission resources over the Ater interface, the TC subrack is usually placed in the telecom equipment room with the NSS devices. That is, the BSC is in BM/TC separated mode. In this case, the speech channel over the Ater interface requires only a bandwidth of 16 kbit/s (full-rate) or 8 kbit/s (half-rate). Compared with the PCM speech channel of 64 kbit/s over the A interface, 75% of the transmission resources is saved. The application of this feature further saves 30% of the transmission resources over the Ater interface. The Ater transmission compression is based on IP over PPP over STM-1, where the IP packets of speech data are encapsulated using the PPP and then transmitted over the channelized STM-1. The key technologies of the Ater transmission compression are as follows: 



ML-PPP/MC-PPP, which helps to improve the reliability and bandwidth usage −

ML-PPP: Multiple PPP links are combined to form one ML-PPP group to provide a link with relatively high bandwidth. At the local end, a large IP packet is divided into several small packets, which are then transmitted concurrently to the peer end over the PPP links. On receiving the packets, the peer end reassembles the packets and restores the original IP packet for further processing. In the ML-PPP, multiple E1s/T1s are combined to provide load sharing for the IP transmission. Therefore, the bandwidth usage is increased.

−

MC-PPP: The priority scheme is introduced to the MC-PPP on the basis of the ML-PPP to facilitate the timely transmission of the real-time data, thereby reducing the transmission delay of the real-time data.

VAD, Ater MUX, PPP MUX, and IP header compression, which help to save the bandwidth. −

VAD: With the coordination of the DTX over the Um interface, this feature can implement the discontinuous transmission of the speech frames over the Ater link. Under typical call condition (VAD = 0.5), the Ater transmission efficiency is doubled compared with that in the traditional condition.

−

Ater MUX: Multiple UDP packets are multiplexed onto one IP/UDP packet. On receiving the IP/UDP packet, the peer end demultiplexes the IP/UDP packet to restore the data. This scheme reduces the transmission resources consumed by the IP/UDP header.

−

PPP MUX: Multiple upper layer packets such as UDP packets are multiplexed onto one PPP frame. The description field of one to two bytes is added to each multiplexed upper layer packets. All multiplexed upper layer packets share the information such as the PPP header and CRC. In this way, the transmission resources consumed by the PPP header are reduced.

IP header compression: The packets in one UDP data flow have the same source IP address, destination IP address, source port, and destination port. With the IP header compression, the redundant information in the IP/UDP header of the UDP data flow is removed. Therefore, the transmission efficiency is improved.

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Enhancement None

Dependency Dependency on BSC hardware Both the BSC and the TC subrack should be configured with the POUc for the transmission over the Ater interface. In Abis over TDM mode, the BM subrack of the BSC should be configured with the DPUc. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-116901 Flex Ater Dependency on other NEs None

5.1.9 GBFD-511201 2G/3G Co-Transmission by TDM Switching Availability This feature was introduced in GBSS8.0.

Summary The SDH/PDH transport network can be shared by the GSM traffic and UMTS traffic using the TDM timeslot cross connection function.

Benefits This feature allows operators to minimize the investments in transmission infrastructure, especially during the UMTS deployment phase when the traffic load of the network is low. With this feature, the UTRAN and GBSS can share the physical transmission media to achieve the exchange of user data and control data.

Description Huawei radio equipment provides the multiplexing of the GSM and UMTS data on the same SDH network by using the TDM timeslot cross connection function. The GSM data flow involves TDM frames and IP packets. When transmitting the IP packets, the BSC and the BTS map the IP packets onto multiple E1 timeslots by using the Abis IP over E1/T1. The UMTS data flow involves ATM packets and IP packets. The RNC and the NodeB map ATM packets or IP packets onto multiple E1 timeslots by using the function of fractional ATM or fractional IP to implement the data transmission. The following figure shows the co-transmission principles.

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GBSS14.0 Optional Feature Description time slot time slot time slot time slot NodeB

TDM SW time slot time slot time slot time slot

time slot time slot time slot time slot

SDH/PDH

time slot time slot time slot time slot

time slot time slot time slot time slot time slot time slot time slot time slot

Co-transmission

GBTS

RNC

TDM SW

GBSC time slot

Idle timeslot

time slot

3G traffic

time slot

2G traffic

This feature supports the TDM-based co-transmission on the Abis interface. That is, the TDM transmission timeslots on the Abis interface are shared by the 2G and 3G services. The following figure shows the 2G/3G co-transmission by TDM switching on the Abis interface. The 2G data is transmitted on some E1 timeslots and the 3G data is transmitted on the remaining timeslots by using the fractional ATM or fractional IP technology. In this scheme, the 2G equipment (BSC and BTS) implements the timeslot cross connection through the transmission interface board.

The GBSS8.0 supports only the TDM-based co-transmission of the following data on the Abis interface: TDM frames of 2G services and ATM packets or IP packets of 3G services.

Enhancement GBSS9.0 The GBSS9.0 supports the Abis IP over E1/T1. The Abis IP over E1/T1 supports the TDM-based co-transmission of the following data on the Abis interface: TDM frames or IP packets of 2G services and ATM packets or IP packets of 3G services.

Dependency Dependency on BSC hardware None. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS/RAN features The dependency of this feature for the GSM services on other features is as follows: If the BSC and the BTS use the IP over E1/T1 on the Abis interface, this feature depends on GBFD-118611 Abis IP over E1/T1. The dependency of this feature for the UMTS services on other features is as follows: Issue V0.5 (2011-08-30)


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WRFD-05030101 ATM over E1T1 on Iub Interface or WRFD-050411 Fractional IP Function on Iub Interface Dependency on other NEs None.

5.1.10 GBFD-115301 Local Multiple Signaling Points Availability This feature was introduced in GBSS6.1.

Summary With this feature, a physical node is logically classified into multiple signaling points. Each signaling point can be independently connected to other signaling points.

Benefits This feature breaks the capacity limitation of a single signaling point using the narrowband signaling. In addition, this feature is compatible with the traditional signaling networking mode while meeting the signaling bandwidth requirements of the high processing capacity of the BSC. Therefore, the operators' investment is saved.

Description With network expansion, development of new services, popularization of the short message service and wireless intelligent network service, and increase in the traffic volume, the signaling flow between different signaling points increases rapidly. According to the protocols related to the SS7 signaling, a maximum of 16 signaling links are allowed between single signaling points. If the 64 kbit/s signaling link is used, a maximum of 1 Mbit/s bandwidth can be provided for a single signaling point in the entire system. This is far from the requirements for the signaling link bandwidth when the BSC is in full configuration. With this feature, a physical node is logically classified into multiple signaling points. Each signaling point can be independently connected to other signaling points. If a physical node is logically classified into N signaling points, the number of links between this physical node and the remote signaling point is extended to N x 16 because the maximum number of signaling links between the OSP and DSP is 16. This feature breaks the limitation of 16 signaling links of a single signaling point using the narrowband signaling and meets the signaling link requirements for large capacity processing of the BSC. In addition, the requirements for the signaling networking capability of the CN are reduced because the high-speed signaling technology is not used. Therefore, the operators' investment is saved. This feature is used together with the High Speed Signaling feature to support more flexible signaling networking mode.

Enhancement GBSS7.0

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This application enhancement supports the use of local multiple signaling points in the MSC pool.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-118602 A over IP or GBFD-118622 A IP over E1/T1 Dependency on other NEs None

5.2 IP Transmission 5.2.1 GBFD-118606 Clock Over IP Availability This feature was introduced in GBSS8.0.

Summary Clock over IP provides accurate clock synchronization for several BTSs in the GBSS IP network. Compared with the GPS clock, Clock over IP is a cost-effective clock solution. The transmission cost is high because the IP timing packets are sent continuously. Huawei GBSS equipment supports the function of defining the interval for sending IP timing packets. It can reduce the transmission bandwidth as long as the BTS clock synchronization is guaranteed.

Benefits In the IP-based GSM network, Clock over IP provides clock synchronization to guarantee the normal operation of the GSM system. Compared with the GPS clock synchronization, Clock over IP significantly reduces the cost of network deployment.

Description Clock over IP is a cost-effective clock solution for BTS synchronization. It consists of the IP clock server and the IP clock client. The IP clock server extracts reference clock source from a clock device such as a GPS or BITS. Then, the IP clock server sends the clock synchronization information to the BTS by sending timing packets. As the IP clock client, the

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BTS performs the adaptation on the IP packets and obtains the clock synchronization information. Every IP timing packet occupies a certain bandwidth. Therefore, in the case of leased network or satellite transmission resources, the continuous transmission of IP timing packets leads to an increased CAPEX and may even affect the ongoing services during peak hours. The GBSS allows operators to define the interval for sending IP timing packets. In such a case, the IP timing packets are sent when the load of the network is light. The BTS clock provided by the GBSS can maintain a precision of 0.05 ppm within 90 days. Therefore, the bandwidth can be saved and the BTS clock can be synchronized by sending the IP timing packets regularly. The application scenario of Clock over IP is shown in the following figure:

Enhancement GBSS8.1 Enhanced Clock over IP is available, which is used for the flexible configuration of clock synchronization mode. GBSS9.0 Primary and secondary IP clock server supported by the BTS: The IP clock server can be configured on the basis of BTSs. The configuration of primary and secondary IP clock servers is supported. When the primary IP clock server becomes faulty, the path to extract the clock signals is switched to the secondary IP clock server, enhancing the flexibility and reliability of the IP clock networking.

Dependency Dependency on BTS hardware

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The BTS must support this feature. Dependency on BSC hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs An independent IP clock server device is required.

5.2.2 GBFD-118620 Clock over IP support 1588v2 Availability This feature was introduced in GBSS9.0.

Summary With this feature, the networking with the clock server that complies with IEEE1588v2 is supported. Therefore, a highly precise synchronization clock for the IP-based BTS is provided. Compared with the GPS clock, this feature is a cost-effective clock solution.


The networking is flexible because the IP-based BTS can be networked with the clock server that complies with IEEE1588v2.



This feature is a cost-effective clock solution because the IP-based BTS can obtain the clock from the IP network.



The IP-based BTS supports the configuration of the primary and secondary IP clock servers, increasing the reliability of the clock system.

Description In TDM networking mode, the BTS can extract the clock signals from the GPS, BITS, or E1 lines. The clock extraction in IP networking mode does not function properly. In all-IP networking mode, the E1 line clock is not available. The GPS line clock is available in the all-IP networking mode but the GPS reception devices, antenna, and feeder must be added, which increases the expenditure. The BITS clock is available for only a few sites. With the Clock over IP feature, the clock solution becomes cost-effective because the clock reference can be obtained from the IP network. The Clock over IP is implemented through the IP clock server and IP clock client. The IP clock server generates a time stamp and sends the time stamp to the BTS that is configured as the IP clock client. The BTS uses an adaptive method to remove the delay and restore the clock. Huawei GBSS supports two types of clock standards: Huawei proprietary clock standard and IEEE1588v2. This feature complies with only IEEE1588v2. With this feature, Huawei BSS can interconnect with the Huawei IP clock server and other clock servers that comply with IEEE1588v2.

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The following figure shows the networking scenario of Clock over IP support 1588v2.

The IP clock server can be deployed as an independent entity in the network. The IP clock client can be deployed in the BTS. No additional hardware is required. An IP clock server can serve up to 512 BTSs. In addition, the IP-based BTS supports the configuration of primary and secondary IP clock servers. When the primary IP clock server becomes faulty, the path to extract the clock signals is switched to the secondary IP clock server, enhancing the reliability of the clock system.

Enhancement GBSS12.0 Frequency Synchronization Based on IEEE1588v2 over MAC: The clock synchronization for the Ethernet can be achieved by using the IEEE1588v2 technology. From the GBSS9.0, IEEE1588v2 over UDP has been applied to the layer 3 of the multi-service transport platform (MSTP) network. In the GBSS12.0, IEEE1588v2 over MAC can be applied to the layer 2 of the MSTP network. IEEE1588v2 over MAC is a technology based on which transmission equipment forwards timestamps according to the MAC addresses instead of the IP addresses. To achieve clock synchronization in the MSTP network, all the involved transmission equipment must support IEEE1588v2 over MAC. There are two types of synchronization based on IEEE1588v2 over MAC, frequency synchronization and time synchronization. Only frequency synchronization is supported by this feature. GBSS14.0 G.8265.1 The IEEE1588 standards were initially applied to industrial automation for accurate time synchronization. In the telecommunications industry, these standards were originally used in distributed networks for clock synchronization. Now, these standards have been applied to wide area networks (WANs). The IEEE1588v2 standards, which were released in 2008, Issue V0.5 (2011-08-30)


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proposed the concept of "profile". "profile" allows vendors to select features to apply to other fields instead of only the industrial automation field. Now, the IEEE1588 standards allow vendors to select an IEEE1588 feature subset ("profile") to implement clock synchronization. As an extension of the concept of "profile", the ITU proposes G.8265.1, which defines interconnection standards for different vendors. Currently, G.8265.1 defines the profile for frequency synchronization in layer 3 unicast mode and allows the interconnection between devices supporting IEEE1588 from different vendors. In this manner, a BTS supporting G.8265.1 can be connected to a clock server supporting G.8265.1 from another vendor.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other functions of the GBSS None Dependency on other NEs This feature should be supported by the clock server that supports the IEEE1588v2 specifications.

5.2.3 GBFD-118202 Synchronous Ethernet Availability This feature was introduced in GBSS12.0.

Summary This feature provides a solution for clock synchronization in the all-IP network. The clock of a synchronous Ethernet can be obtained and recovered from the physical layer of the Ethernet. The solution provided by this feature is easy to deploy, as it does not require additional BSC or BTS hardware.

Benefits The synchronous Ethernet is a key to the solution for all-IP transmission. In addition, it is an economical and convenient solution for clock synchronization in the all-IP network.

Description The clock synchronization technology adopted by this feature is based on the physical layer of the Ethernet. By using this technology, the clock signals can be retrieved from the data flow of the Ethernet link. With this feature, the data is transmitted at the physical layer by adopting the highly precise clock. The receive end can retrieve and recover the clock directly from the data flow. In this way, the precision of the clock is ensured.

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Another benefit of the feature is that it does not require additional BTS hardware to achieve clock synchronization in the all-IP network.

Enhancement None

Dependency Dependency on BSC hardware The IP interface board must be used on the Abis interface. Dependency on BTS hardware This feature applies to only the 3900 series base stations. Dependency on other features GBFD-118601 Abis over IP Dependency on other NEs All relay devices in the transport network must support this feature.

5.2.4 GBFD-118601 Abis over IP Availability This feature was introduced in GBSS8.0.

Summary Abis over IP enables the IP networking over the Abis interface.

Benefits This feature adapts to All IP development trend of future transport layer and protocol development.

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The Abis interface incorporates the features such as high bandwidth and low cost deployment, and it does not have any restrictions on the BSC capacity. The low IP network deployment cost, short construction period, and easy maintenance effectively reduce the CAPEX and OPEX of operators. A firewall ensures the security for the BTS.

Description Abis over IP allows operators to deploy an IP network between the BSC and the BTS. In addition, this feature provides FE and GE interfaces and supports the IPv4 protocol. The BSC connects to the BTS through a LAN or WAN, depending on the location of the BSC and the BTS. Abis over IP supports active/standby mode and load sharing mode, and is reliable. The GBSS adopts the following mechanisms to ensure end-to-end high QoS. 

Physical bandwidth shaping The burst flow in the network is controlled by the buffer and token bucket. If the messages are transmitted at a very high speed, the messages are buffered and transmitted at a uniform speed under the control of the token bucket.



Priority mapping A definite rule is used to identify the messages for different services. Then, the messages are classified and prioritized, and they are associated with the corresponding flow control and resource assignment. According to the load on the current network, a specific flow control action is taken.



Congestion management Congestion occurs when the rate at which data arrives at the port is higher than the rate at which data is sent from the port. In this case, the voice quality deteriorates and the data transmission rate decreases. The traffic statistics of the interface board show that the number of discarded packets increases. As a result, congestion results in the increase of the packet transmission delay and delay variation. Furthermore, an excessively long delay leads to packet retransmission. If congestion increases, a large number of network resources are wasted and improper resource assignment may lead to system deadlock or system breakdown. The problem of shortage of network resources can be solved by increasing the network bandwidth. In addition, preventive mechanisms like tail drop and weighted random early detection (WRED) must be applied to avoid the network congestion. When congestion occurs, the priority queue (PQ) or weighted round robin (WRR) of queue scheduling is used to solve the congestion problem.

IPsec Enhancement GBSS8.1 New QoS mechanisms VLAN are introduced in GBSS8.1. VLAN: Virtual local area network. Based on the switching LAN, the network management software is used to establish an end-to-end logical network across different network segments and different networks. This improves the network processing capability and service management capability. The network logically isolates the data of different applications during transmission. For example, the network allocates the O&M data transferred between the BSC and the BTS, data transferred by signaling messages, and service data to different VLANs. This improves the security of network transmission and simplifies the flow control

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management for data transmission of different applications. In application, one or several BTSs or BSCs in the same physical network can be allocated to a VLAN. GBSS9.0 Static IP address supported by the BTS: This feature supports the configuration of items such as the BTS IP address, BSC IP address, and routing on the site maintenance terminal. Compared with the configuration of dynamic IP address for the GBSS, the configuration of static IP address is more complicated, but does not require the configuration of DHCP relay. GBSS9.0 The GBFD-118609 IP Fault detection based on BFD feature is introduced. Huawei GBSS supports bidirectional forwarding detection (BFD) on the Abis, A, and Gb interfaces. BFD is a method of detecting IP connection failures by periodically transmitting BFD packets between two nodes. When BFD packets are not received within the period of several detection intervals, the communication between the two nodes fails. In this case, procedures such as port switchover or IP rerouting are triggered to prevent traffic loss. The interval of BDF detection is about 100 ms, and therefore it can be used for telecom services over IP. The BFD involves two cases: one hop and multi-hop. For one hop, the two nodes of the BFD are the BSC and a layer 3 device connecting to the BSC, such as the router, BTS, or MGW. For multi-hop, the two nodes of the BFD are the BSC and its peer device, such as a BTS, MGW, or SGSN. The BFD is applicable in the following scenarios: 1. The BSC is connected to a peer device such as the BTS, MGW, or SGSN by using a router. In this case, the BFD can be used to check whether the router is working properly.

BSC p1

p2

R1

R2

R3

BTS/CN

R4

The BFD is activated for detecting any faults in p1 and p2. If p1 is faulty, the BSC triggers an IP rerouting procedure. The packet is then sent and received over p2. 2. The BSC is connected directly to the peer device such as the BTS, MGW, or SGSN. In this case, the BFD can be used to check whether the peer device is working properly. BSC

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p1

Public

BTS/CN

p2

The BFD is activated for detecting any faults in p1 and p2. If p1 is faulty, the BSC triggers an IP rerouting procedure. The packet is then sent and received over p2. GBSS14.0 The BTS built-in firewall function is introduced. The BTS built-in firewall automatically takes effect after the feature GBFD-118601 Abis over IP is enabled. The BTS built-in firewall filters out malicious data and prevents network attacks to avoid a system breakdown when a large number of system resources are consumed by network attacks. The BTS built-in firewall provides the following functions: 

Access Control List (ACL)-based packet filtering: The ACL module sets ACL policies to filter out malicious data. The ACL policy supports sextuple filtering. Sextuple refers to source IP address, source port, destination IP address, destination port, protocol, and DSCP. You can also choose to configure only some of these filters. This feature supports both whitelist-based and blacklist-based filtering.



Attack packet filtering: This filtering provides basic network protection. It can be configured to prevent various types of attacks, such as ARP spoofing, flooding attack, and malformed packet attack.

Dependency Dependency on BSC hardware Embedded PCU should be used. IP Interface board is needed in Abis interface: FG2a/FG2c/GOUa/GOUc. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-117801 Ring Topology GBFD-117701 BSC Local Switch GBFD-117301 Flex Abis GBFD-116601 Abis Bypass

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GBFD-116701 16Kbit RSL and OML on Abis Interface MRFD-210206 Tree Topology MRFD-210204 Chain Topology GBFD-113729 Adaptive Transmission Link Blocking GBFD-119301 Voice Fault Diagnosis Dependency on other NEs The BSC and its peer device must support BFD.

5.2.5 GBFD-118611 Abis IP over E1/T1 Availability This feature was introduced in GBSS9.0.

Summary When TDM is applied over the Abis interface, the IP over E1/T1 scheme can be used to carry traffic and signaling data.

Benefits In the IP over E1/T1 scheme, the IP packets can be carried on the TDM-based network. For the operators that have the abundant TDM transmission resources, the IP over E1/T1 scheme facilitates the evolution to an all-IP network and thereby protects the investment. The use of ML-PPP/MC-PPP enhances the reliability of the Abis links and improves Abis link bandwidth usage. As many as 18 to 21 TRXs can be supported by each E1 with compression technologies such as VAD and Abis MUX. Compared with the traditional TDM transmission, the Abis IP over E1/T1 saves 30% of the transmission resources and saves the lease cost of the TDM transmission resources.

Description In IP over E1/T1, the IP packets of the signaling and traffic data are packed using the PPP and then transmitted over the E1/T1. The BTS and the Abis interface board on the BSC are responsible for processing the PPP/ML-PPP. The IP over E1/T1 can be applied for the networking between the BTS and BSC. The BTS uses the E1/T1, and the BSC uses the E1/T1, channelized STM-1, or FE/GE. The following figure shows the networking modes supported by the Abis IP over E1/T1.

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IP over E1

BTS

IP over E1(STM-1)

SDH

IP over E1

BSC IP over FE/GE

BTS IP over E1

BTS

In IP over E1/T1, the clock can be the same as that in TDM transmission mode. That is, the clock is obtained by locking the clock of one node to the upper-level node over E1. In IP over E1/T1, the clock over IP scheme can also be used. The key technologies in IP over E1/T1 are as follows: 

ML-PPP/MC-PPP, which helps to improve the reliability and bandwidth usage

ML-PPP: Multiple PPP links are combined to form one ML-PPP group to provide a link with relatively high bandwidth. At the local end, a large IP packet is divided into several small packets, which are then transmitted concurrently to the peer end over the PPP links. On receiving the packets, the peer end reassembles the packets and restores the original IP packet for further processing. In the ML-PPP, multiple E1/T1s are combined to provide load sharing for the IP transmission. Therefore, the bandwidth usage is increased. MC-PPP: The priority scheme is introduced to the MC-PPP on the basis of the ML-PPP to facilitate the timely transmission of the real-time data, thereby reducing the transmission delay of the real-time data. 

VAD and Abis MUX, which help to save the bandwidth

VAD: With the coordination of the DTX over the Um interface, this feature can implement the discontinuous transmission of the speech frames over the Abis link. Under typical call condition (VAD = 0.5), the Abis transmission efficiency is doubled compared with that in the traditional condition. Abis MUX: Multiple UDP packets are multiplexed onto one IP/UDP packet. On receiving the IP/UDP packet, the peer end demultiplexes the IP/UDP packet to restore the data. Multiple UDP packets share one IP/UDP packet header, and therefore the IP transmission efficiency is improved. For details, see the description of GBFD-118604 Abis MUX.

Enhancement None

Dependency Dependency on BSC hardware IP over E1/T1 board is needed in Abis interface: PEUa/POUc. Dependency on BTS hardware

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For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-117801 Ring Topology GBFD-117701 BSC Local Switch GBFD-117301 Flex Abis GBFD-116601 Abis Bypass GBFD-116701 16Kbit RSL and OML on Abis Interface GBFD-119301 Voice Fault Diagnosis Dependency on other NEs When the BSC uses the STM-1 or FE transmission, this feature requires the support from the external transmission device.

5.2.6 GBFD-118604 Abis MUX Availability This feature was introduced in GBSS8.1.

Summary If Abis over IP is used without any compression or multiplexing technology, the utilization of transmission resources is low. Compared with TDM, the transmission bandwidth cannot be saved. Therefore, a compression or multiplexing technology for saving the bandwidth must be used in IP transmission mode. Abis MUX is used to save the bandwidth and multiplex the packets. The BSC and the BTS serve as transmitting end and receiving end of each other. When Abis MUX is applied, the transmitting end multiplexes the UDP packets that meet the multiplexing condition. Multiple UDP packets are multiplexed into one IP/UDP header at the transmitting end and then demultiplexed at the receiving end to reconstruct the original data in the IP/UDP packets. Therefore, the transmission efficiency is improved and the bandwidth is saved.

Benefits By multiplexing and demultiplexing the IP/UDP packet, Abis MUX reduces the overhead of each IP packet, increases the efficiency of the IP transmission, and saves the bandwidth. Without the application of Abis MUX, the efficiency in IP transmission is about 32%. Whereas, after Abis MUX is enabled, 14 full-rate speech packets are multiplexed, and the efficiency of IP transmission can reach 73%, which is increased by 40%.

Description The speech payload in GSM is small. After the IP transmission is applied, the speech payload that is carried in the IP/UDP packets is smaller than the IP/UDP header. Therefore, the transmission efficiency of the speech is very low. With the multiplexing of the IP/UDP header, the UDP packets that meet the multiplexing condition are multiplexed at the transmitting end,

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and demultiplexed at the receiving end. In this way, several UDP/IP packets are multiplexed in one UDP/IP packet; in addition, several speech packets share one IP/UDP header. Therefore, the efficiency of link transmission is improved. The principle of Abis MUX is shown as follows:

B efore using A bis Mux

MAC

IP

UDP

Speech payload A

After using A bis Mux

MAC

IP

UDP

Speech payload A+B

MAC

IP

UDP

Speech payload B

Abis MUX requires the support from both the BTS and the BSC. That is, after the BSC/BTS multiplexes UDP packets, the BSC/BTS at the peer end must be able to identify multiplexed and non-multiplexed packets and then demultiplex packets to reconstruct the original data according to the multiplexing protocol.

Enhancement None

Dependency Dependency on BSC hardware IP or IP over E1/T1 board is needed in Abis interface: FG2a/FG2c/GOUa/GOUc/PEUa/POUc. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-118601 Abis over IP or GBFD-118611 Abis IP over E1/T1 Dependency on other NEs None

5.2.7 GBFD-118612 Abis IPHC Availability This feature was introduced in GBSS13.0.

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Summary This feature, Abis IP Header Compression (IPHC), compresses the IP/UDP header of the packets transmitted over the Abis interface to save the transmission resources.

Benefits 

This feature saves more than 30% of transmission resources occupied by typical voice services.



This feature improves the transmission efficiency in a newly deployed network that adopts IP over E1 transmission or in a network where TDM transmission is upgraded to IP transmission. The transmission efficiency is improved notably especially when high-BER transmission media, such as microwave, are used for data transmission.

Description IPHC improves the transmission efficiency by removing redundant information from the IP/UDP header of UDP data streams.

In IP over E1 mode, typical small packets in a standard Abis IP packet such as speech packets occupy only 50-60% of payload. This leads to low transmission efficiency. This feature solves the preceding problem by enabling the transmitting end to compress the IP/UDP header of packets. The compressed packets will be parsed by the receiving end. After the compression, one typical full-rate voice packet can be shortened from 74 bytes to 50 bytes, which saves more than 30% of transmission resources.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For details, see the GBSS14.0 Feature List.

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Dependency on other GBSS features This feature depends on the following features: GBFD-118611 Abis IP over E1/T1 Dependency on other NEs The two ends where the Point-to-Point Protocol (PPP)/Multilink Protocol (MP) is terminated must support IPHC.

5.2.8 GBFD-118602 A over IP Availability This feature was introduced in GBSS8.0.

Summary Huawei GBSS8.0 and GBSS8.1 implements A interface over IP in proprietary protocols. The features include TC in MGW and IP transmission on the signaling plane and user plane.

Benefits With the increasing use of IP transmission in the wireless core network, the compressed speech coding scheme is used on the Nb interface, and the TDM transmission is still used on the A interface. In this way, a call across MSCs needs to be coded and decoded four times. Compared with coding and decoding in TDM transmission mode that occurs only twice, the application of IP transmission in the CN increases the number of TCs required by the BSC and the MGW in the network and deteriorates the voice quality. However, when A interface over IP is applied, together with the IP transmission on CN and transcoder free operation (TrFO), the originated call and terminated call do not need to be coded and decoded. Therefore, the voice quality is improved and the number of TCs required by the BSC and the MGW is reduced. With the increase of the network equipment capacity and the number of nodes, MSC pool is an acknowledged solution that meets the requirements of disaster recovery and backup. In TDM transmission mode, the application of MSC pool over the A interface is difficult to be implemented due to the complexity of the physical connection. The IP transmission, however, effectively address this problem. In addition, A interface over IP complies with the trend of all IP in the transmission network and simplifies the network maintenance.

Description The details of this feature are as follows: 

TC in MGW To improve the voice quality, the feature of TrFO is supported. The TCs located in the BSS are removed from the existing GSM network and are placed in the MGW. Under the control of the signaling plane, when the calling and called MSs use the same speech versions or compatible AMR codec set, the MGW performs coding and decoding without using TC. Therefore, TrFO is implemented and then the voice quality is improved. However, if the calling and called MSs use different speech versions or

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incompatible AMR codec set, the TC in the MGW is required to converse speech version under the control of the MSC-S.

MSC-S A/IP

BSS

Mc/IP MGW A/IP

= Signalling = User p lane



Nc

MSC-S A/IP

BSS

Mc/IP

Nb

MGW A/IP

e.g. AMR coded

e.g. AMR coded

IP based protocol stack

IP based protocol stack

= Transcoder or Transcoder-pair, typically not used in MS-to MS calls

Voice over IP The A interface on the user plane is placed between the BSC and the MGW and adopts the standard RTP/UDP/IP protocol to carry user data. The A interface supports all the following speech codec types in the existing BSS: GSM_FR:

RFC 3551 for GSM_FR.

GSM_HR:

ETSI 101318 for GSM_HR.

GSM_EFR:

RFC 3551 for EFR.

AMR:

RFC 3267 for AMR.

The speech coding scheme on the A interface is the same as that on the Um interface because there is no TC configured in the BSS. However, the speech codec types are different.



BSC

MGW

Payload RTP UDP IP MAC / PPP

Payload RTP UDP IP MAC / PPP

Signaling over IP The BSC supports signaling over IP on the A interface in the M3UA/SCTP/IP protocol stack. The BSC is directly connected to the MSC server through the MTP3 User Adaptation Layer (M3UA), and the data on the signaling plane and user plane can be transmitted through the MGW routes.

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To meet the requirements of TrFO and IP transmission on the user plane, some signaling messages at the BSSMAP is modified. At the same time, the intra-BSS switchover procedure of speech versions is added. The introduction of A the interface over IP has no impact on the DTAP message. BSC

MSS

BSSMAP+ SCCP M3UA SCTP IP MAC / PPP

BSSMAP+ SCCP M3UA SCTP IP MAC / PPP

Enhancement GBSS9.0 A over IP complying with 3GPP specifications: The signaling plane and user plane comply with the related specifications in 3GPP R8. The user plane complies with TS43.903 and the signaling plane complies with TS48.008. The CSD coding complies with RFC4040 and RFC2198. Theoretically, the GBSS is capable of working with the IP-based CN devices (supplied by the competitor) that comply with 3GPP R8. CSD service transmission redundancy in A over IP: Certain CSD services, such as the fax service, are quite sensitive to data loss. The retransmission mechanism for such services is usually insufficient at the application layer. Therefore, the packet loss on the IP transmission network has great impact on such services, for example, the fax is interrupted. This feature enables the same CSD service data block to be transmitted in different RTP frames in A over IP, ensuring the completeness of the data and enhancing the user experience of the CSD services in A over IP. The CSD service transmission redundancy in A over IP supports a maximum of three levels of redundancy; that is, a maximum of two consecutive RTP frames can be discarded. The CSD service bearer in A over IP complies with the RFC4040 specification. The CSD service transmission redundancy in A over IP complies with the RFC2198 specification. The GBFD-118609 IP Fault detection based on BFD feature is introduced. The GBFD-118609 IP Fault detection based on BFD feature is introduced. The GBFD-118609 IP Fault detection based on BFD feature is introduced. Huawei GBSS supports bidirectional forwarding detection (BFD) on the Abis interface, A interface, and Gb interface. BFD is a method of detecting IP connection failures by periodically transmitting BFD packets between two nodes. When BFD packets are not received within the period of several detection intervals, the communication between the two nodes fails. In this case, procedures such as port switchover or IP rerouting are triggered to prevent traffic loss. The interval of BDF detection is about 100 ms, and therefore it can be used for telecom services over IP. For details, see section 5.2.4 "GBFD-118601 Abis over IP."


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The interface board for A over IP must be configured: FG2a/FG2c/GOUa/GOUc. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-115601 Automatic Level Control (ALC) GBFD-115602 Acoustic Echo Cancellation (AEC) GBFD-115603 Automatic Noise Restraint (ANR) GBFD-115703 Automatic Noise Compensation (ANC) GBFD-115704 Enhancement Packet Loss Concealment (EPLC) GBFD-115701 TFO GBFD-117701 BSC Local Switch GBFD-117702 BTS Local Switch GBFD-115711 EVAD It is recommended working with the following features: GBFD-115702 TrFO Dependency on other NEs The MSC/MGW must support this feature. The GBSS 8.0 and GBSS8.1 are only applicable to Huawei MSC/MGW. The BSC and its peer device must support BFD.

5.2.9 GBFD-118622 A IP over E1/T1 Availability This feature was introduced in GBSS9.0.

Summary When the SDH transmission is applied between the GBSS and CN equipment, the traffic and signaling data can be carried by the PPP-based IP transmission over the A interface. The port of the BSC can be E1, T1, or STM-1.

Benefits With the IP over E1/T1 scheme, the IP packets can be carried on the TDM-based network. For the operators that have the TDM transmission resources, the IP over E1/T1 scheme facilitates the evolution to an all-IP network and thereby protects the investment. The utilization of ML-PPP/MC-PPP enhances the reliability of the A interface links and improves the bandwidth usage of A interface links.

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The technique of UDP multiplexing over the A interface increases the IP transmission efficiency. Compared with the traditional TDM transmission, the A IP over E1/T1 saves 30% of the transmission resources and saves the lease cost of the TDM transmission resources.

Description In IP over E1/T1, the IP packets of the signaling and traffic data are packed using the PPP and then transmitted over the E1/T1/CSTM-1. The peer entity and the A interface board on the BSC are responsible for processing the PPP/ML-PPP. This feature enables the networking between the BSC and CN to use IP over PPP over E1/T1/CSTM-1. The BSC adopts the E1/T1 or channelized STM-1 ports. The router at the peer end or CN can adopt the E1/T1, channelized STM-1, or FE/GE ports. The following figure shows the networking modes supported by the A IP over E1/T1. IP over E1/T1/CSTM-1 IP over E1/T1/CSTM1

SD H

BSC

IP over FE/GE

IP over E1/T1/CSTM1

MGW

MSC

IP over FE/GE

MGW

IP over E1/T1/CSTM-1

IP over FE/GE

IP over FE/GE

ROUTER

MSC

MGW

MSC

In IP over E1/T1, the clock can be the same as that in TDM transmission mode. That is, the clock is obtained by locking the clock of one node to the upper-level node over E1. The key technologies in IP over E1/T1 are as follows: 

ML-PPP/MC-PPP, which helps to improve the reliability and bandwidth usage

ML-PPP: Multiple PPP links are combined to form one ML-PPP group to provide a link with relatively high bandwidth. At the local end, a large IP packet is divided into several small packets, which are then transmitted concurrently to the peer end over the PPP links. On receiving the packets, the peer end reassembles the packets and restores the original IP packet for further processing. In the ML-PPP, multiple E1/T1s are combined to provide load sharing for the IP transmission. Therefore, the bandwidth usage is increased. MC-PPP: The priority scheme is introduced to the MC-PPP on the basis of the ML-PPP to facilitate the timely transmission of the real-time data, thereby reducing the transmission delay of the real-time data. 

UDP multiplexing on the A interface, which help to save the bandwidth

UDP multiplexing on the A interface: After A over IP is introduced, the RTP/UDP/IP packaging is applied to the data of the user plane, bringing down the transmission efficiency. In this technique, however, multiple RTP packets are multiplexed onto one UDP packet. As a result, the proportion of the packet header to the total packet decreases, and therefore the A interface transmission efficiency is increased. For details, see GBFD-118610 UDP MUX for A Transmission.

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Enhancement None

Dependency Dependency on BSC hardware IP over E1/T1 Interface board is needed in A interface: PEUa/POUc. To be specific, when the A interface uses the E1/T1 ports, the PEUa should be configured. When the A interface uses the STM-1 ports, the POUc should be configured. With this feature, the TC processing unit is no longer required on the BSC. The TC processing unit is integrated into the MGW. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-115601 Automatic Level Control (ALC) GBFD-115602 Acoustic Echo Cancellation (AEC) GBFD-115603 Automatic Noise Restraint (ANR) GBFD-115703 Automatic Noise Compensation (ANC) GBFD-115704 Enhancement Packet Loss Concealment (EPLC) GBFD-115701 TFO GBFD-113525 DTMF Downlink Message Filter Dependency on other NEs This feature should be supported by the CN and transmission equipment that support IP over PPP.

5.2.10 GBFD-118610 UDP MUX for A Transmission Availability This feature was introduced in GBSS9.0.

Summary In A over IP, the RTP/UDP/IP packaging is applied to the data of the user plane, reducing the transmission efficiency. When this feature is enabled, however, multiple RTP packets are multiplexed onto one UDP packet. As a result, the proportion of the packet header to the total packet decreases, and therefore the A interface transmission efficiency is increased.

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Benefits The UDP multiplexing improves the usage of the transmission resources on the A interface, protects the investment, and reduces the O&M cost. The transmission efficiency can be increased by 30% to 40% depending on the number of packets that are multiplexed.

Description In A over IP, the RTP/UDP/IP packaging is applied to the packets of the user plane, bringing down the transmission efficiency, particularly in the case of short packets of CS data. This feature can solve the problem by adding a UDP multiplexing subheader which is smaller than UDP and multiplexing multiple RTP packets onto one UDP packet. As a result, the proportion of the packet header to the total packet decreases, and therefore the A interface transmission efficiency is increased. The transmission efficiency can be increased by 30% to 40% depending on the number of packets that are multiplexed. The UDP multiplexing is applicable regardless of whether the RTP header is compressed. The UDP multiplexing is independent of the physical bearer. That is, the UDP multiplexing is applicable to IP over E1/T1, IP over channelized STM-1 (CPOS), or IP over FE/GE.

Enhancement None

Dependency Dependency on BSC hardware IP or IP over E1/T1 board is needed in A interface: FG2a/FG2c/GOUa/GOUc/PEUa/POUc. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-118602 A over IP or GBFD-118622 A IP over E1/T1 Dependency on other NEs The CN must support this feature.

5.2.11 GBFD-118623 TDM/IP Dual Transmission over A Interface Availability This feature was introduced in GBSS12.0.

Summary This feature enables TDM transport and IP transport to be used simultaneously over the A interface on the BSC side. Telecom operators can set a proper traffic proportion so that some

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calls use TDM bearer and other calls use IP bearer. This feature is applicable to the scenario where GSM is upgraded from the TDM network to the IP network.

Benefits When GSM is upgraded from the TDM network to the IP network, telecom operators can reconstruct the transport network gradually to ensure smooth migration.

Description As specified by 3GPP GERAN Releases 7 and 8, the IP-based transport protocols for the signaling and user planes are introduced into the A interface, and A over IP officially becomes the network reconstruction trend. When GSM is upgraded from the TDM network to the IP network, the BSC and the CN (including the MSC server and MGW) need to support TDM transport and IP transport simultaneously on the A interface in a specified period. The purpose is to ensure the smooth migration of the transport network. The following stages are involved in the migration from TDM to IP on the A interface: 1) All-TDM stage: All the calls use TDM bearer during this stage. 2) TDM and IP dual-stack transport stage: Traffic is distributed to TDM transport and IP transport according to the preset proportion during this stage. For example, 80% of the new calls are established on TDM and 20% of the new calls are established on IP. 3) All-IP stage: All the calls use IP bearer and the original TDM bearer can be removed during this stage. The following figure shows the topology where TDM and IP dual-stack transport is applied to the A interface. The BSC in the A-interface dual-stack transport state must support the TDM-based PCM voice and IP-based compressed voice simultaneously. When TDM transport is applied to the A interface, the TC in the BSS is used. When IP transport is applied to the A interface, the TC in the MGW is used.

A/TDM

A/IP BSS

MSC-S

Nc

A/TDM

MSC-S

Mc/IP

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Mc/IP

A/TDM

A/IP

A/IP

A/TDM

MGW

Nb

MGW

Signaling

Transcoder

User plane

Transcoder or Transcoder pair


A/IP

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Enhancement None

Dependency Dependency on BSC hardware The BSC must be configured with IP interface boards FG2a/FG2c/GOUa/GOUc for the A interface. Dependency on BTS hardware None Dependency on other GBSS features GBFD-118602 A over IP Dependency on other NEs The CN must support both IP and TDM.

5.2.12 GBFD-118603 Gb over IP Availability This feature was introduced in GBSS8.0.

Summary Gb over IP allows operators to deploy an IP network instead of using frame relay (FR) between the BSC and the SGSN. Therefore, operators can fully utilize the advantages of IP transmission so as to save the transmission cost and carry different types of services.

Benefits This feature can reduce the cost of network investment. The IP transmission simplifies network maintenance, saving the operation cost and maintenance expense. The application of IP transmission increases the bandwidth over the Gb interface. Therefore, the Gb interface does not restrict the bit rate of subscribers. This feature facilitates the SGSN pool function. Compared with the frame relay mode, the cost of using SGSN pool function in IP transmission is much lower because the SGSN pool function requires a large number of links on the Gb interface. Therefore, SGSN pool can be implemented in a more cost-efficient way.

Description Gb over IP complies with the 3GPP protocol. When Gb over IP is enabled, SGSN pool can be implemented after the license of SGSN pool is obtained and no upgrade is required in the existing hardware.

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Gb over IP supports dynamic configuration and highly automatic upgrade compared with the frame relay mode. If SGSN pool is enabled, the application of Gb over IP can reduce the configuration work for the Gb interface. The Gb interface supports the FE/GE interface, the interface in active/standby mode or load sharing mode, and the interconnection between the CN and the LAN or MAN. The Gb interface supports IP services based on the DiffServ mechanism and guarantees the QoS of the services with different levels. When the IP network is congested, the data packets of the service with higher priority are preferably transmitted. The BSC supports two kinds of end-to-end communications from the BSC to the SGSN, that is, the FR network and IP network. In addition, two protocol stacks can work simultaneously to minimize the impact of the IP transmission on the existing services. When Gb over IP is applied, the transmission equipment supporting IP transmission should be used. Compared with the FR equipment, the cost is lower. With the increase of packet data services, the requirement for the bandwidth over the Gb interface is higher. Gb over IP can compress the IP header and enable the data over the Gb interface to share the bandwidth, improving the transmission efficiency and reducing the transmission cost. This feature does not support VLAN or multiplexing method.

Enhancement GBSS9.0 The GBFD-118609 IP Fault detection based on BFD feature is introduced. The GBFD-118609 IP Fault detection based on BFD feature is introduced. Huawei GBSS supports bidirectional forwarding detection (BFD) on the Abis interface, A interface, and Gb interface. BFD is a method of detecting IP connection failures by periodically transmitting BFD packets between two nodes. When BFD packets are not received within the period of several detection intervals, the communication between the two nodes fails. In this case, procedures such as port switchover or IP rerouting are triggered to prevent traffic loss. The interval of BDF detection is about 100 ms, and therefore it can be used for telecom services over IP. For details, see section 5.2.4 "GBFD-118601 Abis over IP."

Dependency Dependency on BSC hardware The interface board for Gb over IP must be configured: FG2a/FG2c/GOUc. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-114101 GPRS Dependency on other NEs The SGSN must support this feature.

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The BSC and its peer device must support BFD.

5.2.13 GBFD-118605 IP QoS Availability This feature was introduced in GBSS8.1.

Summary IP QoS provides a series of QoS mechanisms for the IP transmission to ensure the transmission quality. The QoS mechanisms include admission control, congestion management, port traffic shaping, queue scheduling, DSCP, and VLAN.

Benefits IP QoS ensures the KPIs in the wireless network and prevents the drop in QoS caused by the network congestion. IP QoS meets different requirements of applications and enhances user experience.

Description After the IP transmission is applied to the GBSS, the transmission resources are multiplexed instead of being occupied exclusively. When the transmission resources are not sufficient, the congestion may cause the increase of delay, packet loss, and call drop. Therefore, the QoS mechanisms are required to guarantee the transmission quality of IP network. Huawei GBSS equipment provides different QoS mechanisms at each protocol layer to guarantee an end-to-end QoS, as listed in the following table: Protocol Layer

QoS Mechanism

Application layer

1. Admission control 2. Congestion management based on the congestion status of transmission resources 3. Logical port shaping 4. IP PATH

IP layer

1. Priority mapping

Data link layer

1. VLAN 2. BFD detection 3. Congestion management (PQ, WRR, tail drop, WRED)

Physical layer



1. Physical bandwidth shaping

QoS mechanism at physical layer Physical bandwidth shaping: The burst flow in the network is controlled by the buffer and token bucket. If the messages are transmitted at a very high speed, the messages are buffered and transmitted at a uniform speed under the control of the token bucket.

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QoS mechanism at data link layer VLAN: Virtual local area network (VLAN) logically isolates the data of different applications during transmission. For example, the network allocates the O&M data transferred between the BSC and the BTS, data transferred by signaling messages, and service data to different VLANs. This improves the security of network transmission. This function applies to Abis over IP and A over IP. BFD detection: bidirectional forwarding detection (BFD) is a simple Hello protocol, which is similar to the neighbor detection part of the routing protocols. Two systems periodically send BFD check messages on the channel between the two systems. If one system does not receive any check message from the other system for a long time, you can infer that the channel is faulty. BFD detection enables the BSC to detect the link fault between the BSC and the peer equipment in IP network quickly and then initiate handover or active/standby switchover. Therefore, the link fault can be quickly identified and isolated and therefore the service interruption time is greatly reduced. BFD is applicable when IP transmission is established on Abis, A, and Gb interface. Congestion management: The congestion occurs when the rate at which the data arrives at the port is higher than the rate at which the data is sent from the port. Then, the voice quality deteriorates and the data transmission rate reduces. In addition, the congestion increases the packet transmission delay and delay variation. An excessively long delay causes packet retransmission and further aggravates the network congestion. Therefore, the congestion control mechanisms are used to prevent congestion for the packets received, such as the tail drop and WRED. The queuing scheduling techniques such as PQ and WRR are used to send the packets in real time based on the priority of each packet. The congestion management is applicable when IP transmission is established on Abis, A, and Gb interface.



IP layer Priority mapping: A definite rule is used to identify the messages for different services. Then, the messages are classified and prioritized, and they are associated with the corresponding flow control and resource assignment. The QoS mapping in the transmission network is implemented according to the data with different priorities. Priority mapping is applicable to Abis over IP and A over IP.



Application layer Admission control: Admission control is a major measure used to prevent congestion and is an important mechanism of the entire QoS policy. The system determines the bandwidth required for the access of new services to prevent port or link congestion and to ensure the QoS of the entire system. Congestion management: The admission control applies only to new services that attempt to access the system; whereas, the congestion management applies to the admitted services and alleviates the congestion when transmission resources are congested. The BSC decreases the rates of the services that already access the network in the congestion control and bandwidth reservation phases to increase the processing capacity of the entire system. IP PATH is used for admission control and LDR is used for congestion control. According to the congestion severity, the admission control is classified into three phases: normal admission, congestion control, and bandwidth reservation. Different admission strategies are applied in different phases. Normal admission phase: The transmission resources are not congested and all services are allowed to access the system. Congestion control phase: The transmission resources are slightly congested and the services after rate reduction are allowed to access the system. The rate control measures

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consist of the PS coding control, CS AMR coding control, and preferential assignment of TCHHs for CS services. Bandwidth reservation phase: The transmission resources are severely congested. When the bandwidth is available, intra-BSC handover, incoming BSC handover, and paging response are admitted. New services with high priorities are allowed to wait in queue and preempt transmission resources, whereas other types of services are rejected. Admission control is performed on the basis of the bandwidth usage of the IP PATH. When an IP path is configured on the logical port or resource group, two-level (IP PATH and logical port/resource group) admission is performed. Logical port shaping: Generally, one physical FE/GE port on the BSC can carry the traffic of multiple BTSs. Traffic shaping on this physical port cannot be implemented on these BTSs. When burst flow occurs on one BTS, the traffic processing of other BTSs may be seriously affected. Therefore, the BSC performs two-level traffic shaping on the logical ports on the BTSs in Abis over IP mode. In this way, the BSC accurately controls the traffic flow on the BTSs according to the processing capacity of each BTS. This prevents the prolonged delay of services and the increase of delay variation and packet loss rate. IP PATH: In Abis over IP mode, the IP paths of different bandwidths are configured according to the service type. This guarantees the transmission resource for each service type and prevents different service types from preempting the transmission resources. The IP path is a logical link with virtual bandwidth and is carried on the physical link in the IP transmission network. The IP PATH mechanism is mainly applicable to admission control. That is, admission control is performed during the MS access phase according to the service type and the bandwidth of the corresponding IP path. Therefore, the effect of the services on each other can be reduced.

logical port

BE

EF

AF4

Priority Queues

BE

EF

logical port

AF4

PQ+WR Rqueues

AF4

Priority Queues PQ+WR Rqueues

EF

PQ+WR Rqueues

Priority Queues

BE

logical port

1 level shaper

IP Scheduler 2 level shaper FE port

IP/Ethernet Transport Network

Enhancement None

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Dependency Dependency on BSC hardware IP Interface board is needed in Abis/A/Gb interface: FG2a/FG2c/GOUa/GOUc Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-118601 Abis over IP or GBFD-118611 Abis IP over E1/T1 or GBFD-118602 A over IP or GBFD-118622 A IP over E1/T1 or GBFD-118603 Gb over IP Dependency on other NEs None

5.2.14 GBFD-118630 Ethernet OAM Availability This feature was introduced in GBSS9.0.

Summary The GBSS supports two types of Ethernet OAM: point-to-point Ethernet O&M (802.3ah) and end-to-end Ethernet O&M (802.1ag). The functions of Ethernet OAM consist of fault detection, monitoring, verification, and identification. Through these functions, this feature achieves reliability and high availability of Ethernet services.

Benefits The Ethernet O&M helps the operator to manage user access in terms of detection, monitoring, and rectification of Ethernet faults. This feature achieves reliability and high availability of Ethernet services, enables the service provider to provide economical and efficient advanced Ethernet services, and ensures that the services have high quality and reliability that are required by telecommunications services. This feature is implemented at the GBSS equipment, minimizing the impact of Ethernet bandwidth fluctuation or faults on the GBSS.

Description With the introduction of IP GSM, the Ethernet as a type of transport bearer is widely used. As a Layer 2 protocol, Ethernet O&M can report the status of the network at the data link layer. Therefore, the network is monitored and managed more effectively. The functions of Ethernet OAM consist of fault detection, notification, verification, and identification. The faults Issue V0.5 (2011-08-30)


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involve the hardware faults that can be detected by the physical layer, such as link failure, and the software faults that cannot be detected by the physical layer, such as memory bridging unit damage. Ethernet O&M plays a significant role in reducing CAPEX/OPEX and complying with the Service Level Agreement (SLA). The GBSS supports two types of Ethernet OAM: point-to-point Ethernet OAM (802.3ah) and end-to-end Ethernet OAM (802.1ag). 1. Point-to-point Ethernet OAM The point-to-point Ethernet OAM complies with IEEE 802.3ah. The point-to-point Ethernet OAM concerns the OAM of the last mile rather than the specific services. The OAM implements point-to-point maintenance of the Ethernet through mechanisms such as OAM discovery, loopback, link monitoring, and fault detection.

2. End-to-end Ethernet OAM The end-to-end Ethernet OAM complies with IEEE 802.1ag. Regarding the OAM domain as a whole, the end-to-end Ethernet OAM establishes end-to-end detection to perform maintenance of the Ethernet based on the services. When the BSC detects Ethernet faults or degraded network performance through the Ethernet OAM, the BSC, based on the practical configuration, can perform operations such as route reselection, port switchover, and board switchover to ensure proper communication on the Ethernet.

Enhancement None

Dependency Dependency on BSC hardware IP Interface board is needed in Abis/A/Gb interface: FG2a/FG2c/GOUa/GOUc Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other functions of the GBSS This feature depends on the following features:

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GBFD-118601 Abis over IP GBFD-118602 A over IP GBFD-118603 Gb over IP Dependency on other NEs The Ethernet OAM protocol should be supported by the interconnected transmission equipment.

5.3 Satellite Transmission 5.3.1 GBFD-113901 Satellite Transmission over Abis Interface Availability This feature was introduced in GBSS6.1.

Summary Satellite communication features wide coverage, fine mobility, flexible link scheduling, and good topography adaptability. With this feature, operators can deploy BTSs to provide radio services in mountainous regions, outlying areas, isolated islands, and other areas that are difficult to be reached through conventional transmission.

Benefits With this feature, the operator can deploy BTSs in the areas that are difficult to be reached through conventional transmission, solving the communication problem in those areas. This feature can also be used for emergency communication.

Description The Abis interface of ordinary GSM equipment does not support satellite transmission because satellite transmission encounters problems such as delay, jitter, and bit error. This feature takes these factors into account, makes improvements on the Abis signaling processing, voice processing, and clock processing, and uses special satellite transmission equipment, addressing the drawbacks of satellite transmission. With this feature, the voice quality of the CS services can reach the normal level. However, there is a certain delay in voice because there is a long transmission delay in satellite transmission. In the cell using satellite transmission, the EDGE services are supported.

Enhancement None

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5.3.2 GBFD-113902 Satellite Transmission over A Interface Availability This feature was introduced in GBSS6.1.

Summary Satellite communication features wide coverage, fine mobility, flexible link scheduling, and good topography adaptability. This feature enables the operator to deploy the BSS system to provide radio services in the areas that are difficult to be reached through conventional transmission.


In the areas that are difficult to be reached through conventional transmission, hot spots on special occasions, or emergency conditions, this feature enables the operator to deploy the BSS system to provide radio services.



The satellite transmission resources over the A interface can be shared with other interfaces.

Description The conventional terrestrial transmission has the problems such as small coverage, poor topography adaptability, and poor flexibility. With this feature, the operator can deploy the BSS system in isolated islands or small areas to share the same CN resources with other BSS systems. Huawei also provides the A interface monitoring function. This enables the operator to monitor the circuit usage over the A interface based on which the operator can extend the circuit (or add the transmission links). Therefore, the cost of the satellite link usage is effectively reduced.

Enhancement None

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5.3.3 GBFD-113903 Satellite Transmission over Ater Interface Availability This feature was introduced in GBSS6.1.

Summary Satellite communication features wide coverage, fine mobility, flexible link scheduling, and good topography adaptability. This feature enables the operator to deploy the BSS system to provide radio services in the areas that are difficult to be reached through conventional transmission.


This feature enables the operator to deploy the BSS system to provide radio services in special geographical areas or emergency conditions.



With this feature, the BSC signaling processing unit can be deployed on the BTS side and the TRAU unit can be configured in the CN equipment room. Therefore, the transmission cost is reduced because the Ater interface adopts the 4:1 multiplexing mode.

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The satellite transmission resources over the Ater interface can be shared with other interfaces.

Description This feature enables the operator to deploy the BSS system to provide radio services in the areas that are difficult to be reached through conventional transmission. With this feature, the TRAU can be configured in the CN equipment room. This enables the circuit over the Ater interface between the BSC signaling processing unit and the TRAU to use the 4:1 multiplexing mode. As a result, the bandwidth required by the A interface circuit is greatly reduced and therefore the cost of using the A interface is reduced. In addition, Huawei provides the Ater interface monitoring function. This enables the operator to configure the bandwidth for satellite transmission over the Ater interface as required and

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dynamically extend the circuit with the increase of the traffic volume. In this manner, the circuit lease cost, the operation and maintenance cost is greatly reduced.

Enhancement None


5.3.4 GBFD-113905 Satellite Transmission over Gb Interface Availability This feature was introduced in GBSS8.0.

Summary With this feature, the operator can deploy the network to provide radio services in the areas that are difficult to be reached through conventional transmission.


This feature enables the operator to deploy the BSS system to provide PS services in special geographical areas.



The satellite transmission resources over the Gb interface can be shared with other interfaces.

Description With this feature, the operator can deploy the network to provide radio services in the areas that are difficult to be reached through conventional transmission.

Enhancement None

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5.4 RAN Sharing 5.4.1 GBFD-118701 RAN Sharing Availability This feature was introduced in GBSS8.1.

Summary On the condition that independency of CNs of multiple operators is maintained, RAN Sharing enables multiple operators to share one GBSS network so that they can use the resources (including the BSC, BTS, antenna system, transmission, and so on) in the GBSS network simultaneously.

Benefits The GBSS equipment sharing enables new operators to access the network easily and implement the network coverage quickly. Operators can fully utilize the network resources and increase the revenue by sharing the equipment on the existing network. This feature reduces the comprehensive operation cost of operators. Each operator carries out radio services independently so that they can maintain the independence of business development from the network planning.

Description RAN Sharing supports a maximum of four operators. Each operator has an independent CN (MSC and SGSN). The shared GBSS uses a uniform network management system, which implements comprehensive management of all the resources in the GBSS. The shared services in the GBSS are CS services and PS services. For processing these services, the GBSS routes them to the specific CN to which the cell belongs.

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In addition, RAN Sharing supports the coexistence of shared resources and non-shared resources in the BSS. For example, some resources in the BSS, such as all the resources under one BTS belong to a specific operator. Therefore, other operators cannot use these resources. The resources under other BTSs in the GBSS can be shared by multiple operators. The network structure of RAN Sharing is shown as follows:

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware Refer to the BTS Dependency of feature list. Dependency on other GBSS features None Dependency on other NEs The following M2000 feature must be activated: WOFD-220200 RAN Sharing Management-GBSS

5.4.2 GBFD-118704 Abis Independent Transmission Availability This feature was introduced in GBSS13.0.

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Summary In a RAN sharing network, multiple telecom operators share a base station and associated auxiliary devices. Cells of different telecom operators can reside under one base station, but each cell can only belong to one telecom operator. The transmission resources under the base station can be shared among telecom operators or exclusively used by their respective telecom operators.

Benefits Telecom operators flexibly deploy transmission resources, which are applicable in different scenarios.

Description In a RAN sharing network, base station resources are usually shared among telecom operators to reduce Capital Expenditure (CAPEX). Base station resources include site location, power supply, antenna system, and transmission resources. If telecom operators have their respective transport networks and transmission resources are not shared, the Abis interface must support independent transmission. Each telecom operator's signaling and traffic data is carried by their own transmission resources over the Abis interface. Only the OM link provided by a specific telecom operator is shared among telecom operators. In Abis over TDM transmission mode, E1 ports are not shared among telecom operators. In Abis over IP transmission mode, logical transmission resources are not shared among telecom operators.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following feature: GBFD-118701 RAN Sharing Dependency on other NEs None

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5.4.3 GBFD-118702 MOCN Shared Cell Availability This feature was introduced in GBSS12.0.

Summary BSS Sharing enables multiple telecom operators to share BSS equipment on a per BTS basis while still using their respective core network (CN) equipment. A cell, however, cannot be shared among telecom operators. That is, cells of different operators can reside under one base station, but each cell can only belong to one telecom operator. MOCN Shared Cell enables multiple telecom operators to share the BSS equipment on a per cell basis while still using their respective CN equipment. That is, all the resources under a cell can work as a resource pool and be shared among telecom operators.

Benefits The cell-based BSS equipment sharing not only drastically improves the sharing degree of spectrum, BSS equipment, transmission bandwidth, and network management, but also minimizes the CAPEX of the operator. The efficient use of GSM spectrum resources lays a firm foundation for the development of LTE.

Description In existing GSM networks, multiple PLMN identifiers cannot be broadcast in a cell due to protocol limitations, and a GSM MS cannot receive multiple PLMN identifiers. Therefore, multiple telecom operators use a common PLMN identifier in a GSM cell. The BSC selects a CN node to serve an MS depending on the setting of the MOCN Switch parameter, which can be set to CNSEL(CN Select) or BSCSEL(BSC Select). In a network with the MOCN Shared Cell feature enabled, both the roaming MSs and the MSs subscribing to different telecom operators exist. The BSC identifies the IMSI, TMSI, or P-TMSI to determine whether an MS is a subscribing MS or a roaming MS: 

If the MS is a subscribing MS, the BSC routes the MS to the CN of the telecom operator to which the MS subscribes.



If the MS is a roaming MS, the BSC routes this MS to a specific telecom operator according to the specified rate of distributing roaming MSs among telecom operators.

When a telecom operator is specified for an MS, the CS-domain handover area, NC2 area, and PS-domain handover area of the MS must belong to the area permitted by the telecom operator. After this feature is enabled, the BSC integrates this feature with other handover decisions (such as decisions based on coverage, quality, load, or priorities) to select a target cell for a subscribing MS or a roaming MS. Then, the BSC triggers an intra-GSM or GSM-to-UMTS CS-domain handover, NC2, or PS-domain handover.

Enhancement None

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Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-117401 MSC Pool GBFD-119701 SGSN Pool Dependency on other NEs If the MS routing is selected by the CN, the list of VLRs in which an MS is allowed to roam needs to be configured at the HLR, or the list of LAIs in which an MS is allowed to roam needs to be configured at the MSC server.

5.4.4 GBFD-118703 IMSI-Based Handover Availability This feature was introduced in GBSS12.0.

Summary To meet the operator's requirements of network planning and service, the network can be divided into multiple areas, and an MS of a specific type can move only in the specified area to obtain services. That is, the operator can restrict the service area of an MS by configuring the mapping between the IMSI number ranges and the network areas.

Benefits In RAN sharing mode, one BSC is shared by multiple operators, which may have different partner operators. An MS can be handed over only between the networks of partner operators. In non-RAN sharing mode, MSs are provided with differentiated services based on service areas.

Description The operator can divide a network into multiple areas called handover shared areas at the BSC, based on location areas. In addition, the operator configures the mapping between the IMSI number ranges and the handover shared areas to restrict the area in which an MS can be handed over. During an intra-BSC handover, the BSC determines the target cell to which an MS is to be handed over according to the IMSI number range of the MS. In this case, the target cell must belong to the handover shared area. During an incoming inter-BSC or incoming inter-RAT handover, the BSC determines whether to allow the MS to access the target cell according to the IMSI number range of the MS. If the

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MS is not allowed to access the target cell, the handover request is rejected. That is, the MS cannot be handed over to this BSC.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware None Dependency on other GBSS features None Dependency on other NEs The Common Id and Handover Request messages sent by the MSC are required to carry IMSI.

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6

Site Solution

6.1 PICO Solution 6.1.1 GBFD-510601 PICO Automatic Configuration and Planning Availability This feature was introduced in GBSS8.1.

Summary The pico base station is BTS3900B. After being installed and powered on, the BTS3900B can connect to the BSC automatically with the network automatic detection function. Operators do not need to configure radio parameters for cells. The M2000 obtains radio parameters based on frequency bands and scanning results of the uplink and downlink level of surrounding frequencies reported from the BTS, and then performs the automatic configuration and planning of the BTS39000B.

Benefits 

This feature helps operators to rapidly deploy the network and flexibly adjust the network layout.



This feature helps reduce the workload of manual configuration once the network is adjusted.

Description The BTS3900B is a new generation pico base station launched by Huawei. It is small and light, has the plug-and-play feature, and supports indoor installation. The automatic configuration and planning function of the BTS3900B provides simple and easy installation for operators. After being equipped with hardware and powered on, the BTS3900B automatically performs the internal check to confirm that the hardware is properly installed. After the self-check is complete, the BTS3900B automatically configures the parameters related to IP transmission and establishes the encrypted IP transmission links with the BSC and the M2000. Then, the BTS3900B reports its device configurations to the M2000. The M2000 calculates the


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available radio parameters automatically based on the information about the frequency bands and ambient radio environment reported by the BTS3900B, and then sends the parameters including frequencies, BSIC, CGI, and so on to the BSC to configure based on the parameters. After the basic parameters are configured, the BTS3900B can work normally and process services. After the network runs for a period of time, you can manually initiate the automatic planning procedure of the BTS3900B through the M2000 if the network adjustment is required. Only a few manual configurations are required during the automatic planning procedure. Therefore, the BSC provides a mechanism of reporting event alarms to timely notify users of any exception during automatic planning.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The following M2000 feature must be activated: WOFD-180800 Pico BTS Automatic Planning-GBSS

6.1.2 GBFD-510602 PICO Synchronization Availability This feature was introduced in GBSS8.1.

Summary The pico base station is BTS3900B. The BTS3900B implements the frequency synchronization on the Um interface by demodulating the signals on the frequency correction channel (FCCH) and synchronization channel (SCH) on the main BCCH in the surrounding macro BTSs and then adjusting the frequency offset.

Benefits With this feature, operators need to provide neither the external clock source nor the GPS hardware for frequency synchronization, saving the cost of deploying sites and O&M cost.

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Description In the GSM network, the frequencies must be synchronized on the Um interface among BTSs. Otherwise, the network quality is affected. For example, the handover success rate drops. At present, four solutions are employed to implement frequency synchronization on the Um interface: external BITS clock, IPCLK, upper-level BSC clock, and GPS clock. All these four solutions require the external clock source or the GPS hardware, and therefore are not applicable to the indoor BTS3900B. This feature, however, can implement frequency synchronization on the Um interface between the pico base station and the surrounding macro BTSs by using software to provide the 13 MHz synchronization clock. The BTS3900B applies for frequencies of neighboring cells for synchronization and modulates the FCCH and SCH to select a target frequency. Then, the BTS3900B calculates the frequency offset to the target frequency and corrects its frequency to achieve frequency synchronization on the Um interface.

Enhancement None


6.1.3 GBFD-510603 PICO Dual-band Auto-planning Availability This feature was introduced in GBSS12.0.

Summary A BTS3900B is a PICO base station. Dual-band automatic planning is an extension of the existing single-band automatic planning. The PICO Dual-band Auto-planning feature supports automatic planning of the frequencies on the 900 MHz and 1800 MHz frequency bands or on the 850 MHz and 1900 MHz frequency bands.

Benefits The PICO Dual-band Auto-planning feature enables more flexible and high-quality network planning. Therefore, the site construction workload and the maintenance cost are reduced.

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Description After the PICO Dual-band Auto-planning feature is introduced, the BTS3900B supports not only single-band automatic planning but also automatic planning of the frequencies on the 900 MHz and 1800 MHz frequency bands or on the 850 MHz and 1900 MHz frequency bands. The BTS3900B scans the uplink and downlink frequencies specified by the operator and then reports the frequency scanning result to the M2000. Based on the frequency scanning result, the M2000 evaluates the interference to each frequency. The M2000 then considers the neighboring relationships of the surrounding base stations to select the frequency with the minimum interference as the working frequency of the BTS3900B. The BTS3900B supports three frequency planning modes. The operator can select a proper mode according to the actual conditions. 1. Co-BCCH dual-band cell mode: The M2000 allocates the BCCH frequency on the low frequency band, for example, the 900 MHz or 850 MHz frequency band, and then allocates a TCH frequency on the low or high frequency band. 2. Band adaptive selection mode: Based on the dual-band frequency scanning result reported by the BTS3900B, the M2000 selects the frequency with the minimum interference as the working frequency. The frequency band of the selected frequency becomes the working band of the BTS3900B. That is, the M2000 configures the BTS3900B as a single-band cell on the working band. 3. Specified band mode: The BTS3900B scans the frequencies on the two frequency bands and then reports the frequency scanning result to the M2000. The M2000 selects the working frequency only from the specified frequency band. The M2000 then configures the BTS3900B as a single-band cell on the specified frequency band.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware Only the BTS3900B supports this feature. Dependency on other GBSS features None Dependency on other NEs The following M2000 feature must be activated: WOFD-180800 Pico BTS Automatic Planning-GBSS

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6.1.4 GBFD-510604 PICO USB Encryption Availability This feature was introduced in GBSS12.0.

Summary A BTS3900B is a PICO base station. When a BTS3900B is locally commissioned, a USB device is used to save the configuration file. The PICO USB Encryption feature enables the encryption of the configuration file in the USB device so that the file is not displayed as plain text. In this way, the risk of disclosure of the configuration file is reduced.

Benefits The risk of disclosure of information because the files in the USB device are lost or stolen is reduced.

Description When a BTS3900B is locally commissioned, a USB device is used to save the configuration file. This file contains important configuration information, such as the IP addresses of network elements and IPsec keys. If the information is saved as plain text, it may be stolen or disclosed. After the PICO USB Encryption feature is introduced, the configuration file is encrypted by using encryption software on the M2000 side and then is decrypted on the BTS side. In this manner, the configuration file in the USB device is not displayed as plain text, ensuring information security.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware Only the BTS3900B supports this feature. Dependency on other GBSS features None Dependency on other NEs The M2000 needs to support this feature.

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6.1.5 GBFD-510605 PICO Access Control List (ACL) Availability This feature was introduced in GBSS12.0.

Summary A BTS3900B is a PICO base station. The BTS3900B filters out illegal packets at the receiving ports after packet analysis so that these packets do not enter the BTS3900B. In this manner, the robustness and anti-attack capability of the BTS3900B are improved.

Benefits The anti-attack capability of the BTS3900B in an IP transport network is improved.

Description In IP transmission mode, the BTS3900B can use an existing public IP transport network to transmit data. Compared with a private transport network, the public transport network has greater security vulnerabilities and is more vulnerable to hacker attack. The ports of the BTS3900B can filter the received packets. These ports receive and process only the ARP, DHCP, DNS, ISAKMP (IKE), ESP, TCP, and ICMP packets but discard the packets of other types. The BTS3900B filters out illegal packets so that they do not enter the BTS3900B. Therefore, the CPU usage of the BTS3900B is reduced. To some extent, the stability and the anti-attack capability of the BTS3900B are also improved.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware Only the BTS3900B supports this feature. Dependency on other GBSS features None Dependency on other NEs None

6.1.6 GBFD-510606 PICO Sleeping Mode Availability This feature was introduced in GBSS12.0.

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Summary A BTS3900B is a PICO base station. In the specified period, the TRX power amplifiers of the cell under a BTS3900B can be shut down to reduce power consumption.

Benefits Power consumption is reduced by shutting down network devices during the period when there is no traffic. Therefore, the OPEX is cut down.

Description The BTS3900B is an industry-leading compact PICO base station. It features small size, flexible site selection, and easy installation, enabling fast and cost-effective blind-spot coverage. In some temporary blind-spot coverage areas, such as office areas, temporary meeting rooms, temporary exhibition halls, and warehouses, wireless communication services are not required in the period when there is no traffic, for example, at night. With the PICO Sleeping Mode feature, the cell under the BTS3900B can be shut down in the specified period to reduce power consumption. The operator can specify the period during which a PICO cell is shut down, for example, between 0:00 a.m. and 6:00 a.m. During this period, the power amplifiers of all the TRXs (including the BCCH TRX) in the cell are shut down. In PICO sleeping mode, wireless communication services are unavailable within the coverage area of the PICO cell.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware Only the BTS3900B supports this feature. Dependency on other GBSS features None Dependency on other NEs The M2000 needs to support this feature.

6.1.7 GBFD-510607 PICO Automatic Optimization Availability This feature was introduced in GBSS12.0.

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Summary A BTS3900B is a PICO base station. If the working frequency of an operational BTS3900B is severely interfered, the BTS3900B can perform automatic frequency planning under the control of the M2000.

Benefits After this feature is introduced, the BTS3900B automatically improves the network QoS when its working frequency is interfered. In this manner, the network optimization workload and the maintenance cost are reduced.

Description The M2000 periodically analyzes the uplink and downlink interference-related traffic statistics of the BTS3900B. When the working frequency of the BTS3900B is found severely interfered, the M2000 instructs the BTS3900B to restart uplink and downlink frequency scanning. Based on the frequency scanning result, the M2000 selects the frequency with the minimum interference as the working frequency of the BTS3900B. Through automatic optimization of the working frequency, the BTS3900B avoids using the frequency with severe interference so that the speech quality and traffic KPIs in the coverage area are improved significantly. Accordingly, in the coverage area, the handover success rate increases whereas the call drop rate decreases.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The following M2000 feature must be activated: WOFD-170100 Pico BTS Frequency Automatic Optimizing-GBSS

6.1.8 GBFD-510608 PICO Transceiver Redundancy Availability This feature was introduced in GBSS13.0.

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Introduction A BTS3900B supports a maximum of two transceivers (TRXs). Usually, one TRX operates and the other TRX is idle. After this feature is introduced, one TRX automatically starts operating if the other TRX malfunctions.


Reduced out-of-service duration



Decreased OM workload

Description When one TRX configured for a BTS3900B malfunctions, the BTS3900B is reset automatically. After the BTS3900B restarts, it reconfigures the data on the other TRX. Then, the BTS3900B starts operating again. This type of switchover also can be performed manually in remote mode.

Enhancement None


6.2 EasyGSM Solution 6.2.1 GBFD-510701 Compact BTS Automatic Configuration and Planning Availability This feature was introduced in GBSS8.1.

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Summary The Compact BTS is BTS3900E. After being installed and powered on, the BTS3900E can connect to the BSC automatically. Operators do not need to configure radio parameters for cells. The M2000 obtains radio parameters based on frequency bands and scanning results of the uplink and downlink level of surrounding frequencies reported from the BTS, and then performs the automatic configuration and planning of the BTS39000E.

Benefits 

This feature helps operators to rapidly deploy the network and flexibly adjust the network layout.



This feature helps reduce the workload of manual configuration once the network is adjusted.

Description The BTS3900E is a new generation pico base station launched by Huawei. It is small and light, has the plug-and-play feature, and supports indoor installation. The automatic configuration and planning function of the BTS3900E provides simple and easy installation for operators. After being equipped with hardware and powered on, the BTS3900E automatically performs the internal check to confirm that the hardware is properly installed. After the self-check is complete, the BTS3900E automatically configures the parameters related to IP transmission and establishes the encrypted IP transmission links with the BSC and the M2000. Then, the BTS3900E reports its device configurations to the M2000. The M2000 calculates the available radio parameters automatically based on the information about the frequency bands and ambient radio environment reported by the BTS3900E, and then sends the parameters including frequencies, BSIC, CGI, and so on to the BSC to configure based on the parameters. After the basic parameters are configured, the BTS3900E can work normally and process services. After the network runs for a period of time, you can manually initiate the automatic planning procedure of the BTS3900E through the M2000 if the network adjustment is required. Only a few manual configurations are required during the automatic planning procedure. Therefore, the BSC provides a mechanism of reporting event alarms to timely notify users of any exception during automatic planning.

Enhancement None


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Dependency on other NEs The following M2000 feature must be activated: WOFD-180900 Compact BTS Automatic Planning-GBSS

6.2.2 GBFD-510702 Compact BTS Automatic Capacity Planning Availability This feature was introduced in GBSS8.1.

Summary The Compact BTS is BTS3900E. According to the traffic volume, the BSC adjusts the output power of the TRX in real time to achieve the balance between capacity and coverage of the network. A cell is initially configured with one TRX of 30 W power. With the increase of the traffic volume, another TRX in the cell is automatically activated, and these two TRXs share the 30 W power.

Benefits With this feature, the network capacity and coverage can be automatically adjusted without manual intervention, reducing the maintenance cost.

Description At the early stage of site deployment, the traffic volume is low. Therefore, the BTS is configured with one TRX, which transmits with 30 W on the GSM900 frequency band. With the slow increase of the traffic volume, when the preset threshold is exceeded, the BSC automatically configures two TRXs, with the total transmit power no more than 30 W. During the operation of the BTS, the system adjusts the TRX transmit power in real time according to the change of the traffic volume. In this way, the coverage is changed, achieving the optimal network performance. This feature mainly applies to the scenario where there are few neighboring cells and the network structure is simple, especially, where the network experiences slow increase of traffic volume.

Enhancement None


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Dependency on other NEs The following M2000 feature must be activated: WOFD-181000 Compact BTS Automatic Capacity Planning-GBSS

6.2.3 GBFD-510704 Compact BTS Automatic Neighbor Cell Planning and Optimization Availability This feature was introduced in GBSS12.0.

Summary The compact BTS is also referred to as the BTS3900E. After this feature is enabled, the M2000 analyzes the scanning information of the downlink frequencies reported by the BTS3900E and therefore obtains the information about the neighboring cells. Based on the obtained information, the M2000 performs the neighboring cell planning of the BTS3900E. If the M2000 determines that the compact BTS has redundant or missing neighboring cells by analyzing the measurement reports, the M2000 triggers the automatic neighboring cell optimization to update neighboring cell relationships.

Benefits 

The network performance is improved without manual intervention. The handover success rate is increased and the call drop rate is decreased.



The workload for manually configuring neighboring cells is greatly reduced to improve the operation and maintenance efficiency.

Description The BTS3900E is a new type of Huawei compact BTS. It is small, light, and has the feature of plug-and-play. It is used in indoor spaces and rural areas. This feature facilitates the installation of the BTS3900E. The following events occur in automatic neighboring cell planning. The M2000 enables the BTS3900E to scan downlink frequencies and then the BTS3900E reports the information about neighboring cells to the M2000. After that, the M2000 adds the scanned cells to the neighboring cell list of the cell under the BTS3900E and adds the cell under the BTS3900E to the neighboring cell list of the scanned cells. Therefore, bidirectional neighboring cell relationships are created. If the scanned cells are not controlled by the M2000, the M2000 can create only unidirectional neighboring cell relationships. If the M2000 determines that the BTS3900E has redundant or missing neighboring cells by analyzing the measurement reports, the M2000 triggers the automatic neighboring cell optimization to update neighboring cell relationships.

Enhancement None

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Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The following M2000 features must be activated: WOFD-181100 Compact BTS Frequency Automatic Optimizing-GBSS WOFD-181200 Compact BTS Automatic Neighboring Relation Optimization-GBSS

6.2.4 GBFD-510705 Compact BTS Timing Power Off Availability This feature was introduced in GBSS12.0.

Summary In rural areas, MS users habitually do not make phone calls at night. Therefore, the traffic of the compact BTS (BTS3900E) is extremely light during such period. This feature allows the BTS to be powered off and on at night as scheduled. In this manner, the power consumption of the BTS can be reduced. The power-off and power-on times can be configured on the BSC.

Benefits This feature helps reduce the power consumption of the BTS at night when there is little traffic. It can reduce the CAPEX on deploying BTSs powered by solar energy, because the reduced power consumption leads to fewer required solar panels, smaller footprint, and decreased costs in site construction and auxiliary devices.

Description This feature can be applied to rural coverage scenarios where MS users habitually do not make phone calls at night. With this feature, the BTS can be powered off and on as scheduled during the period. The feature is applicable to the following powering scenarios: 1. BTS3900E Powered By Electricity Grid In such a powering scenario, the BTS is not powered by solar energy. Telecom operators can specify the power-off and power-on times of the BTS3900E according to the habits of local MS users, so that the BTS can sleep at night, for example from midnight to 5 o'clock. When sleeping, the BTS shuts down some RF devices to reduce power consumption. After this feature is applied to BTS3900E O2, the power consumption of the BTS can be reduced by 100 W. 2. BTS3900E Powered By Solar Energy

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In this scenario, this feature can be used in combination with the solar controller. Telecom operators can set the power-off and power-on times of the BTS3900E on the BSC. The BTS3900E is then powered off and on by the solar controller as scheduled. After the BTS3900E is powered back on, it automatically establishes the connection to the BSC and resumes to the functional state. Compared with the BTS powered by electricity grid, the BTS powered by solar energy will be completely shut down during the specified power-off period, therefore not consuming any power. Note that the BTS3900E cannot process any service during the power-off period. It cannot automatically wake up or power on even if there are service requests. In conclusion, this feature contributes a lot to the reduction of power consumption, especially in the case of the BTS3900E powered by solar energy. It also helps reduce the number of solar panels to a minimum without comprising the quality of service. In this way, the CAPEX on the solar energy devices, which counts for a large percent of the total investment in a site, can be reduced.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The M2000 needs to support this feature. The Power2000, an auxiliary power supply product, is required.

6.2.5 GBFD-510706 Local User Management Availability This feature was introduced in GBSS12.0.

Summary This feature is applicable to a special business mode. In this business mode, the operator contracts out the BTS3900E deployed in a remote rural area to an entrepreneur (hereafter called "village chief"). The village chief then performs local user management. Local user management involves the following aspects: 1.

User registration and deregistration

2.

Local services

3.

Public network services

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Local services in single-BTS3900E mode

Benefits The Local User Management feature enables the operator to launch a new business mode so as to develop a new market. 

After the operator contracts out a BTS3900E to the village chief, the village chief gains profits by providing local services for the users in the village. The village chief is responsible for performing local user registration, working out the charging policy, and charging local users for their communications.



Local user management in a remote rural area can be performed even if the transmission between the public network and the local network is interrupted. In addition, calls can be made between local users and the calls can be charged.



The BTS3900E purchased by the village chief can provide services for public network users of the operator.



In the case that the communication between the BTS3900E and the BSC is interrupted, the BTS3900E attempts to meet the communication requirements of public network users.

Description The Local User Management feature involves the following aspects: 1. User registration and deregistration The village chief that contracts for the BTS3900E purchases a set of SIM cards from the operator. These SIM cards are registered in the operator's network but not registered in the local network. The village chief then sells these SIM cards to the villagers while registering the SIM cards in the local network. Subsequently, the villagers can use mobile phones with these SIM cards to make local calls and external calls. The MSs that are registered in the local network covered by the BTS3900E of the village chief are called local users, whereas other MSs are called public network users. The village chief uses a PC to perform user registration. The user information, such as the MSISDN, IMSI, prepaid fee, and balance are stored on the PC. When a public network user roams into the coverage area of the BTS3900E, the village chief manually adds this user to the local network so as to meet the communication requirements of the public network user. 2. Local services When local user A and local user B camp on the network covered by the BTS3900E of the village chief, the calls made by the two users and the short messages transmitted between them are called local services. The charging of local services is performed at the PC. The village chief uses this PC to print the call detail records (CDRs) of all local calls. Regarding the prepaid users, the PC periodically updates the balance information. Currently, only the monthly fee charging is supported. With respect to local services, the CN neither participates in the service signaling procedure nor records CDRs. Therefore, legal interception, authentication, and encryption cannot be performed. 3. Public network services

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All users except the local users are called public network users. The calls, such as a call made by a local user after it moves to the coverage area of another base station, or a call made by a public network user after it moves to the coverage area of the BTS3900E of the village chief, are called public network services. When a local user moves to the coverage area of another base station, all the charging and calls of this user are processed by the MSC. The village chief combines the CDRs of local calls and the CDRs generated by the public network to calculate the communication fee of the local user. After charging the local user for the communication fee, the village chief makes fee settlement with the operator. 4. Local services in single-BTS3900E mode When the transmission over the Abis interface is interrupted, the BTS3900E enters the single-BTS3900E mode. In this mode, the BTS3900E independently processes all local calls. When the transmission over the Abis interface recovers, the BTS3900E automatically switches from the single-BTS3900E mode to the normal work mode. If a non-local user enters the coverage area of the BTS3900E in single-BTS3900E mode and the village chief does not register this user in the local network, the BTS3900E allocates a temporary MSISDN to the user and notifies the user of the MSISDN through a short message. Subsequently, normal communication services can be processed between the non-local user and local users. The BTS3900E records the CDRs of all users, including local users and non-local users. A CDR contains the fundamental information about a user, such as the IMSI.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It depends on the following features: GBFD-118601 Abis over IP Dependency on other NEs None

6.2.6 GBFD-111613 Weather Adaptive Power Management Availability This feature was introduced in GBSS12.0.

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Summary This feature checks the strength of solar radiation and estimates the power consumption of a site using solar energy as its power supply. Based on the checking and estimation results, the energy consumption behavior, serving time, and service quality of the site can be determined. This feature helps prolong the serving time of the site and minimize the possibility of the site running out of power, while ensuring the desirable service quality. Ultimately, this feature optimizes the deployment of the energy equipment and consequently reduces the related costs.

Benefits 

The power consumption of the sites is reduced. As a result, the emission of carbon dioxide is decreased.



The deployment of the energy equipment is optimized, reducing the related costs and enhancing the reliability of power supply.

Description The administrator/operator configures the related parameters and enters the weather forecast data on the M2000. The BTS obtains from the solar energy controller the information on the power generation capacity of the solar panel, power consumption of the BTS, and remaining capacity of the storage battery. It reports the collected information to the M2000 periodically. The M2000 adjusts the transmit power of the BTS to a proper value based on the estimated power generation capacity (depending on the weather conditions), the actual power generation capacity of the solar panel, and the remaining capacity of the storage battery. This prolongs the battery life and reduces the possibility of the BTS running out of power.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The following M2000 feature must be activated: WOFD-170600 Weather Adaptive Energy Management-GBSS

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6.3 Auxiliary Equipment Management 6.3.1 GBFD-510710 Intelligent Battery Management Availability This feature is introduced in GBSS14.0.

Summary With this feature, 

The battery management mode automatically changes depending on the selected grid type, which prolongs the battery lifespan.



The battery self-protection function is triggered under high temperature, which avoids the overuse of batteries and the consequent damages to the batteries.



The runtime of batteries is displayed after the mains supply is cut off. According to the runtime, users can take measures in advance to avoid service interruption due to power supply cutoff.



Prolonged battery lifespan



Less energy consumption



Reduced operation costs



Improved system stability



Automatic change of the battery management mode:

Benefits

Description The PMU board records the number of times power supply is cut off and the duration of each cutoff. Then, the PMU board determines which grid type is chosen and correspondingly activates a specific power management mode. In grid types 1 and 2, batteries can enter the hibernation state in which batters do not charge or discharge, which helps prolong battery lifespan. Power Supply Cutoff Duration

Grid

Within 15 Days

Type

(Hours)

Charge and

Current

Discharge

Limitation

Mode

Valve

Hibernation Voltage (V)

Hibernation Duration (Days)

Estimated Battery Lifespan Improvement Rate

≤5

1

Mode A

0.10 C

52

13

100%

5-30

2

Mode B

0.15 C

52

6

50%

30-120

3

Mode C

0.15 C

N/A

N/A

0%

≥120

4

Mode C

0.15

N/A

N/A

0%

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The function of the automatic change of the battery management mode is under license control. In addition, this function is disabled by default and you can enable it by running an MML command. 

Self-protection under high temperature:

When batteries maintain a temperature exceeding the threshold for entering the floating charge state for 5 minutes, they enter the state and no alarms are generated. When batteries maintain a temperature exceeding the threshold for the self-protection function for 5 minutes, they are automatically powered off or the voltage of batteries is automatically adjusted. 

Display of the battery runtime:

After the mains supply is cut off, the base station works out the runtime of batteries based on the remaining power capacity, discharge current, and other data. This runtime can be queried by running an MML command. To calculate the runtime of batteries, use the following formula: Runtime of batteries = (Remaining power capacity x Total power capacity x Discharge efficiency)/(Mean discharge current x Aging coefficient)

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features The PMU must be of a version that supports this feature. A license is required to activate the feature. Dependency on other NEs None

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Network Performance

7.1 Coverage Enhancement 7.1.1 GBFD-115901 PBT(Power Boost Technology) Availability This feature was introduced in GBSS6.1.

Summary The Power Boost Technology (PBT) enables the DTRU to transmit the combined signals with high gain and to achieve extended network coverage.


This feature can realize the mutual transformation between the network coverage and the network capacity.



In the initial network deployment stage, the operators can use the PBT to extend the network coverage, reducing the number of BTSs.



When the subscriber number increases and the network capacity needs to be expanded, operator can transform the PBT-enabled single TRX into two common-mode TRXs, protesting the hardware investment.

Description In the DTRU, two TRXs are integrated into a TRX module that is configured with a combiner. The combiner combines the radio signals of the same frequency and same phrase from two TRXs, and then transmits the combined signals. In this way, the downlink transmit power is higher than the transmit power of the original signals, and the transmit power with high gain is achieved and the downlink coverage is extended.

Enhancement None


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7.1.2 GBFD-115902 Transmit Diversity Availability This feature was introduced in GBSS6.1.

Summary To enable this feature, the two TRXs in the DTRU are connected to the two separated antenna feeders respectively, and the two antennas transmit the same downlink signal on the same frequency. Through the introduction of the controllable delay and changeable phase between two signals of the two TRXs, the diversity gain in terms of time and space can be obtained, enhancing the RX signals and reducing the signal attenuation. This in turn, extends the network coverage.


This feature can realize the mutual transformation between the network coverage and the network capacity.



This feature can effectively extend the downlink coverage, reducing the number of required BTSs.



When the requirement for the network coverage decreases and the requirement for the capacity increases, operator can transform the transmit diversity-enabled single TRX into common-mode TRXs.

Description The feature enables the two TRXs that are integrated in the DTRU to transmit the correlated signals on the same frequency. This provides two independent downlink multi-path signals, and these signals are processed by the equalizer of the MS. In this way, the diversity gain is obtained, and the quality of the RX signal is improved. Therefore, the downlink coverage is improved. If the DTRU works in single TRX mode, this feature can be enabled through remote data configuration.

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Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It is mutually exclusive with the following features: GBFD-510104 Multi-site Cell It is mutually exclusive with the following features when using RRU3008/RRU3908: GBFD-118106 Dynamic Power Sharing (Dual PA power sharing) Dependency on other NEs None

7.1.3 GBFD-115903 4-Way Receiver Diversity Availability This feature was introduced in GBSS6.1.

Summary The 4-way receiver diversity technology allows four antennas (four uni-polarized antennas or two dual-polarized antennas) to receive the mutipath uplink signals from one cell. Then the received signals are combined. Compared with two-way receiver diversity, four-way receiver diversity can improve the receive sensitivity, extending the uplink coverage.

Benefits The 4-way receiver diversity technology can enhance the uplink RX signal strength by increasing the receive gain of the BTS antennas without increasing the transmit power of the MS. In this way, the cell coverage is extended and the improved QoS can be achieved.

Description The coverage of a cell is determined by the transmit power of the BTS and MS, and the receive gain of the BTS antenna. Because the transmit power of an MS is much lower than that of a BTS, in most cases, the actual coverage is lower than the designed value and the voice quality deteriorates. With appropriate design, the 4-way receiver diversity technology allows one TRX module to receive the uplink signals from four RX channels and then combine the uplink signals to achieve better signal quality and demodulation performance. Therefore, the receive sensitivity

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is improved, and the receive effect is much better than that of none receiver diversity and that of two-way receiver diversity.

Enhancement None


7.1.4 GBFD-118101 Dynamic Transmit Diversity Availability This feature was introduced in GBSS8.0.

Summary Dynamic transmit diversity is timeslot-based transmit diversity.

Benefits Currently, the TRX-based transmit diversity is applied. In this case, a double-transceiver unit serves as a single-transceiver unit. However, timeslot-based dynamic transmit diversity maintains optimal balance between capacity and coverage. Dynamic transmit diversity makes fully use of idle timeslots and expands the coverage in the areas with weak signals, such as at cell borders, indoors, or in cars. This feature helps save network resources and capacity. Based on actual network conditions, the application on some timeslots helps expand the coverage and improve the downlink output capacity, balancing the traffic volume and coverage. Dynamic transmit diversity can increase the handover success rate of the MSs at the border of a cell. This is mainly used to improve the concentric performance when the co-BCCH function is enabled.

Description Dynamic transmit diversity is timeslot-based transmit diversity. One MS occupies one TCH during a call, and the voice quality is monitored by the MR. If the voice quality of an MS is lower than the predefined threshold, the network enables dynamic transmit diversity to assign the same timeslots on two adjacent TRXs to the MS. The signals carried on the two timeslots Issue V0.5 (2011-08-30)


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are the same, and the phases are also identical. The signals are sent out through different transmit ports and then enhanced through signal combination. Therefore, the receive quality of the signals is improved. If the channel of the same timeslot of the adjacent TRX is occupied by an MS, the intra-cell handover is performed to switch the MS to an idle channel so that the adjacent channel can be used for dynamic transmit diversity. The receive quality of the MS that is switched to an idle channel is good. Therefore, no call drop occurs during the handover. If the voice quality is higher than the predefined threshold, the network disables dynamic transmit diversity and then releases the adjacent channel. Compared with common transmit diversity, dynamic transmit diversity does not decrease the capacity by half. It can achieve a balance between capacity and coverage and realize flexible conversion.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on GBFD-113201 Concentric Cell. It is mutually exclusive with the following features: GBFD-113701 Frequency Hopping (baseband hopping) GBFD-113703 Antenna Frequency Hopping GBFD-510104 Multi-site Cell It is mutually exclusive with the following features when using multi-carrier RRU dynamic TX diversity: GBFD-118106 Dynamic Power Sharing(Dual PA power sharing) Dependency on other NEs None

7.1.5 GBFD-118102 Dynamic PBT (Power Boost Technology) Availability This feature was introduced in GBSS8.0.

Summary Dynamic Power Boost Technology (PBT) is timeslot-based PBT.

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Benefits Currently, the TRX-based PBT is applied. In this case, a double-transceiver unit serves as a single-transceiver unit. Timeslot-based PBT, however, maintains optimal balance between capacity and coverage. Dynamic PBT makes full use of idle timeslots and expands the coverage in the areas with weak signals, such as at cell borders, indoors, or in cars. This feature helps save network resources and capacity. Based on actual network conditions, this feature helps balance the traffic volume and coverage. Dynamic PBT can increase the handover success rate of the MSs at the border of a cell. This helps improve the concentric cell performance when the co-BCCH function is enabled.

Description Dynamic PBT is timeslot-based PBT. One MS occupies one TCH during a call, and the voice quality is monitored by the MR. 

If the signal strength of an MS is lower than the preset threshold, the network enables dynamic PBT. In this case, the channels corresponding to the same timeslot of two TRXs in one TRX module cannot be assigned to the MSs; whereas the RF channels serving as backup channels can provide PBT service. The signals and the phases of the traffic timeslot in the RF channel are the same as those of the same timeslot in the same TRX module of the backup channel. The signals are strengthened after the combination, and therefore the signal strength of MSs is enhanced.



If the channel of the same timeslot of the adjacent TRX is occupied by an MS, the intra-cell handover is performed to switch the MS to an idle channel so that the adjacent channel can be used for dynamic PBT. The receive quality of the MS that is switched to an idle channel is good. Therefore, no call drop occurs during the handover.



If the signal strength of an MS is higher than the preset threshold, the network disables dynamic PBT. Then, the borrowed channel is restored to the idle state and provides access services.

Compared with common PBT, dynamic PBT does not decrease the capacity by half. It can achieve a balance between capacity and coverage and realize flexible conversion.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on GBFD-113201 Concentric Cell. It is mutually exclusive with the following features:

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GBFD-113701 Frequency Hopping (baseband hopping) GBFD-113703 Antenna Frequency Hopping GBFD-510104 Multi-site Cell Dependency on other NEs None

7.1.6 GBFD-118104 Enhanced EDGE Coverage Availability This feature was introduced in GBSS12.0.

Summary This feature increases the maximum transmit power of PS services by using the coverage enhancement and power sharing techniques, enlarging the coverage area of the EDGE network. This feature is applicable to both dual-carrier TRXs and multi-carrier TRXs.

Benefits The feature increases the TRX transmit power in the 8PSK modulation scheme and the data throughput at cell border. This improves user experience.

Description In a GSM network, CS services and low-rate PS services use the GMSK modulation scheme (CS1–4 and MCS1–4); high-rate PS services use the 8PSK modulation scheme (MCS5–9). In the case of the 8PSK modulation scheme, the peak-to-average power ratio (PAPR) of a TRX will increase. Before the introduction of this feature, the transmit power of the TRX needs to be rolled back by 1.8 dB to ensure the linear output of the power amplifier. The transmit power on EDGE channels that uses the 8PSK modulation scheme decreases by comparison with the GMSK modulation scheme. This leads to bad user experience. To solve this problem, Huawei has developed the feature Enhanced EDGE Coverage. By adopting the coverage enhancement and power sharing techniques, the maximum transmit power of the PS service is increased. With this feature, the data throughput at cell border is increased. This feature is applicable to both dual-carrier TRXs and multi-carrier TRXs. With respect to the dual-carrier TRX, the maximum transmit power of the PS service is increased by using the dynamic transmit diversity and dynamic power boost technology (PBT) techniques on the same timeslot of different carriers. In this way, the cell coverage of the PS service can be comparable to that of the CS service. With respect to the multi-carrier TRX, the maximum transmit power of the PS service is increased by allocating the power margin of the multi-carrier TRX to the 8PSK traffic channel. The power margin always exists because the power amplifier of the multi-carrier TRX does not transmit signals at full power in most cases due to power control and the existence of idle timeslots. By using the power margin, the cell coverage of the PS service can be comparable to that of the CS service. The maximum transmit power in the 8PSK modulation scheme should not exceed that in the GMSK modulation scheme. Therefore, the network planning will not be affected.

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Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-114201 EGPRS It is mutually exclusive with the following features: GBFD-510104 Multi-site Cell Dependency on other NEs None

7.1.7 GBFD-118106 Dynamic Power Sharing Availability This feature is available from GBSS13.0.

Summary The output power can be shared between TRXs at the timeslot level and be dynamically adjusted to increase the network coverage.

Benefits This feature increases the output power of TRXs, enhances the cell coverage, and improves the power utilization of the Power Amplifier (PA).

Description Dynamic Power Sharing is a type of cell coverage maximization solution that aims to meet different power requirements of users distributed in different areas of a cell. Users distributed in different areas of a cell require different transmit power to access the radio network. Generally, users near the BTS require low transmit power; whereas users far from the BTS require high transmit power. The Dynamic Power Sharing feature dynamically adjusts the transmit power of channels according to the power required by different calls to meet the power requirements of users far from the BTS. When the user distribution in a cell dynamically changes, the dynamic transmit power of the TRXs that are enabled with this feature can be greater than the average available static power of the TRXs to increase the cell coverage with the same PA output power.

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Improvement on downlink coverage In a network with poor downlink signal quality or low-speed downlink PS services, dynamic power sharing can be enabled to reduce the proportion of users with weak coverage. This improves speech quality and increases data throughput, thereby improving user experience and reducing user complaints. The Dynamic Power Sharing feature can be enabled only when the PA or PAs whose output power is shared support the multi-carrier RF module. There are two types of Dynamic Power Sharing, namely, single-PA dynamic power sharing and dual-PA dynamic power sharing. Single-PA dynamic power sharing. Assume that the multi-carrier RF module GRFU is used. The output power of three to six TRXs on the GRFU can be dynamically shared. The single-PA dynamic power sharing function improves the output power compared with static power. Dual-PA dynamic power sharing. Assume that two GRFU modules are used. The TRXs provided by the two GRFU modules work in the resource pool mode, and the output power is shared between the TRXs in the resource pool. The dual-PA dynamic power sharing function can further improve the output power of TRXs in large configuration scenarios. When the dual-PA dynamic power sharing function is enabled, the operating frequencies of the two RF modules must be within the Downlink Frequency Bandwidth (DFB) (for example, the DFB is 12.5 MHz when the operating frequencies of the RRU share the output power of one PA, and the DFB is 15 MHz when the operating frequencies of the RFU share the output power of one PA). Currently, if the RRU is enabled with the dual-PA dynamic power sharing function, the RRU must be configured in the single-cell single-module 2-way transmit mode. If the RFU is enabled with the dual-PA dynamic power sharing function, the RFU must be configured in the single-cell dual-module mode. Huawei is committed to optimize the network KPIs through algorithm improvements during dynamic power sharing. The network KPIs can be further optimized when this feature is used together with Huawei network planning and network optimization services.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the GBFD-119115 Power Control The single-PA dynamic power sharing function cannot be used together with any of the following features: GBFD-117002 IBCA GBFD-117001 Flex MAIO GBFD-118701 RAN Sharing

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GBFD-114001 Extended Cell (dual-timeslot extension function) When the RFU uses the dual-PA dynamic power sharing function, the function cannot be used together with any of the following features: GBFD-111602 TRX Power Amplifier Intelligent Shutdown GBFD-118701 RAN Sharing GBFD-113201 Concentric Cell GBFD-114501 Co-BCCH Cell GBFD-113701 RF hopping(Inter-module) GBFD-117001 Flex MAIO GBFD-118701 RAN Sharing GBFD-114001 Extended Cell (dual-timeslot extension function) When the RRU uses the dual-PA dynamic power sharing function, the function cannot be used together with any of the following features: GBFD-111602 TRX Power Amplifier Intelligent Shutdown GBFD-118701 RAN Sharing GBFD-113201 Concentric Cell GBFD-115902 Transmit Diversity GBFD-118101 Dynamic Transmit Diversity GBFD-117002 IBCA GBFD-117001 Flex MAIO GBFD-114001 Extended Cell (dual-timeslot extension function) GBFD-510104 Multi-site Cell Dependency on other NEs: None

7.1.8 GBFD-114001 Extended Cell Availability This feature was introduced in GBSS6.1.

Summary The application of extended cell breaks the coverage limit of 35 km of a GSM cell. This helps operators to provide wider coverage in special areas.

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Benefits The extended cell extends the coverage of the BTS and enables MSs to perform services in long-distance areas, such as in vast plains and seas. In this way, the scope of network services is extended and the network quality is improved.

Description According to the GSM specifications, the maximum TA of a cell on the Um interface is 63 bits. Hence, the coverage radius of a cell cannot exceed 35 km. In the vast and sparsely populated areas where the traffic is light and the transmission and power supply facilities are unavailable, the cells with a coverage radius greater than 35 km are required. The extended cell breaks the coverage limit of 35 km of a common cell. When this feature is enabled, the coverage radius of a cell can reach up to 120 km. This feature enables operators to deploy the GSM network rapidly in a cost-effective way in remote areas, improving the profitability. If the coverage radius of a cell exceeds 35 km, the signal delay exceeds the maximum TA of 63 bits. When an MS moves to the border of the cell, the MS transmits signals with the maximum permissible TA value. If the MS keeps moving outwards, the system cannot adjust the TA value in an adaptive way because the TA has reached the maximum value. In this case, some signals transmitted by the MS are sent to the BTS receiver on the next timeslot. To solve this problem, the extended cell feature can be used. When this feature is enabled, two continuous timeslots are assigned for each MS call and the receiver window of the BTS receiver is also extended to the width of two timeslots. Therefore, the cell coverage radius is extended to more than 35 km. To enable the MSs in the extended coverage area to initiate calls at any time, the BCCH, CCCH, and SDCCH should be assigned two timeslots. In the double-timeslot extended cell, the GPRS/EGPRS services are supported.

Enhancement GBSS8.1 The downlink throughput is enhanced in the double-timeslot extended cell. In the cells with a coverage radius of more than 35 km, such as coast coverage, island coverage, or wide coverage on land, the MS supporting multislot capability can be assigned PDCHs for four downlink timeslots and one uplink timeslot. The extended cell can provide a data throughput that is four times higher than that in a common cell with a single downlink timeslot for service establishment. This accelerates the download speed, enhances user experience, and improves the data service profitability of operators.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following feature: GBFD-113201 Concentric Cell It is mutually exclusive with the following features:

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GBFD-115830 VAMOS GBFD-510101 Automatic Frequency Correction (AFC) Dependency on other NEs None

7.2 Capacity Improvement 7.2.1 GBFD-113201 Concentric Cell Availability This feature was introduced in GBSS6.1.

Summary A concentric cell consists of an overlaid subcell and an underlaid subcell. Different frequency reuse patterns can be applied to the overlaid and underlaid subcells.

Benefits The tight frequency reuse pattern is applied to the overlaid subcell. Therefore, the system capacity is expanded without affecting the voice quality.

Description With the number of subscribers increasing, frequency resources do not meet the growing capacity demand. Therefore, tight frequency reuse must be applied to increase frequency usage and network capacity. Tight frequency reuse, however, may greatly increase interference and even result in deterioration of voice quality. It is necessary to reduce interference and ensure voice quality in the tight frequency reuse pattern. The concentric cell technology divides an ordinary cell into two service layers: overlaid subcell and underlaid subcell. 

For an MS in the underlaid subcell but not in the overlaid subcell, a TRX, such as the BCCH TRX, in the loose frequency reuse pattern should be assigned.



For an MS in the overlaid subcell, a TRX, such as a non-BCCH TRX, in the tight frequency reuse pattern should be assigned.

The tight frequency reuse pattern in the overlaid subcell improves the system capacity. Compared with the MSs in the underlaid subcell, the MSs in the overlaid subcell are far from the interference sources, and therefore the voice quality is guaranteed even if the tight frequency reuse pattern is applied to the overlaid subcell. The voice quality of the MSs in the underlaid subcell is also guaranteed when the loose frequency reuse pattern is applied. When the capacity of the coverage area changes, the channels in the overlaid subcell and underlaid subcell should be adjusted. For example, the traffic volume increases because a large number of calls are made within a short period in the overlaid subcell. Adjusting the TRX from the underlaid subcell to the overlaid subcell can expand the capacity of the overlaid subcell and therefore solve the problem of burst traffic increase. When the traffic volume becomes light, the original settings are restored. Issue V0.5 (2011-08-30)


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The BSS provides the power control, channel assignment, and handover algorithms regarding the concentric cell to balance the traffic distribution in the concentric cell.

Enhancement GBSS7.0 Support for Main BCCH Configured in Overlaid Subcell: The BCCH can be configured either in the underlaid subcell or in the overlaid subcell. The BCCH configured in the overlaid subcell can increase the network capacity because the tight frequency reuse pattern is applied to the overlaid subcell. When the BCCH is configured in the overlaid subcell, the coverage area of the overlaid subcell must be equivalent to that of the underlaid subcell. This can reduce failures in handovers from the overlaid subcell to the underlaid subcell and reduce failures in overlaid subcell assignments, improving the network performance. Support for PDCH configured in Overlaid Subcell: The number of PDCHs increases with the growth of PS services. This aggravates the TCH congestion in the underlaid subcell. Configuring the PDCH in the overlaid subcell can absorb the PS services into the overlaid subcell, minimizing the congestion in the underlaid subcell and increasing the capacity of the concentric cell. The parameters of concentric handover should be set for CS services and PS services separately. This can implement timely handovers in CS domain and PS domain and reduce call drops.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature and the following feature are mutually exclusive: GBFD-115830 VAMOS Dependency on other NEs None

7.2.2 GBFD-114501 Co-BCCH Cell Availability This feature was introduced in GBSS6.1.

Summary The co-BCCH cell refers to a cell where the TRXs on the GSM900/DCS1800, GSM850/DCS1800, or GSM850/PCS1900 coexist. The TRXs on two bands are distributed in the overlaid subcell and underlaid subcell that share one BCCH TRX. The co-BCCH cell can expand the network capacity and reduce the interference between cells.

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Benefits This feature helps improve the cell capacity and reduce cell reselections and inter-cell handovers for the MS. In a co-BCCH cell, the overlaid subcell and underlaid subcell share one BCCH TRX, reducing the number of BCCH TRXs and minimizing the interference between BCCH TRXs.

Description The co-BCCH cell is based on the concentric cell. The TRXs on the GSM900 or GSM850 are configured in the underlaid subcell to extend cell coverage; the TRXs on the DCS1800 or PCS1900 are configured in the overlaid subcell to absorb traffic. Before the channel assignment, the system determines the bands supported by the MS. If the MS supports the bands in the underlaid and overlaid subcells, the channel assignment strategy of the concentric cell is applied. Otherwise, only the channel in the underlaid subcell can be assigned to the MS. The system assigns channels on different bands to the MS based on the receive level, receive quality, and TA value. The underlaid subcell is used for extending cell coverage and the overlaid subcell is used for absorbing traffic. Therefore, the cell coverage is maximized and the capacity balance between the overlaid subcell and the underlaid subcell is maintained. In a co-BCCH cell, the TRXs on different bands belong to one cell, and one BCCH is shared by both the underlaid subcell and overlaid subcell. Compared with the common dual-band network, one BCCH is saved and used as a TCH, and therefore the system capacity is enhanced. In addition, the TCHs on the two bands are integrated in a cell so that the channels can be shared.

Enhancement GBSS8.1 Support for different frequency hopping (FH) type used by TRXs in overlaid/underlaid subcells: The FH type is not a cell-level parameter. In a cell, different TRXs may use different FH types. Generally, the baseband FH is applied to the underlaid subcell because of insufficient frequencies; whereas the RF FH is applied to the overlaid subcell because of sufficient frequencies. This helps obtain a high FH gain.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following feature: GBFD-113201 Concentric Cell Dependency on other NEs None

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7.2.3 GBFD-114402 Enhanced Dual-band Network Availability This feature was introduced in GBSS7.0.

Summary The enhanced dual-band network is an improvement on the existing dual-band network. In the enhanced dual-band network, two co-sited cells with different coverage areas logically form a cell group. One is an overlaid subcell, and the other is an underlaid subcell. The enhanced dual-band network algorithm enables channel sharing and load balancing between the two cells in a cell group.

Benefits The enhanced dual-band network enables a network to support multiple frequency bands and enables operators to expand frequency bands. If the KPIs are acceptable, the resource sharing of the overlaid and underlaid subcells expands the system capacity. This feature supports the tight frequency reuse pattern. The tight frequency reuse pattern is applied to the overlaid subcell and the loose frequency reuse pattern is applied to the underlaid subcell.

Description Based on the multi-band network, the enhanced dual-band network enhances the channel sharing of the overlaid and underlaid subcells. The enhanced dual-band network enables two co-sited cells with different coverage areas to form a cell group logically. The two cells are configured with the BCCH and SDCCH. One is an overlaid subcell, and the other is an underlaid subcell. The enhanced dual-band network algorithm enables channel sharing and load balancing between the two cells in a cell group. The overlaid and underlaid subcells can obtain the information about each other, such as signal level, channel, and load. Therefore, the KPIs such as the handover success rate and assignment success rate can be kept at proper values when the channels in the overlaid and underlaid subcells are shared. The two cells cannot be assigned to two different operators. 

Tight frequency reuse In terms of functions, tight frequency reuse is similar to the concentric cell. In a cell group of an enhanced dual-band network, loose frequency reuse can be applied to the underlaid subcell, and tight frequency reuse is applied to the overlaid subcell. If an MS accesses the network from the overlaid subcell and the load in the underlaid subcell is low, the channel assignment is preferably performed in the underlaid subcell to minimize the interference to the entire network. If an MS accesses the network from the underlaid subcell and the load in the underlaid subcell is high, the channel assignment is preferably performed in the overlaid subcell to achieve the traffic balance in the cell group. In addition, the enhanced dual-band network supports dynamic distribution of the MSs that are having calls according to the load and coverage.

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Enhancement None


7.2.4 GBFD-117001 Flex MAIO Availability This feature was introduced in GBSS7.0.

Summary When this feature is enabled, the channels with less interference are preferentially selected during channel assignment. If there is interference in the selected channel, the MAIO with the minimum interference is assigned to the channel.


Reduces the adjacent-channel and co-channel interference in the GSM system.



Achieves tight frequency reuse within the BTSs and therefore improves the system capacity.

Description Under the BTSs with large capacity, adjacent-channel or co-channel interference is likely to occur among channels because the frequency resources are insufficient and tight frequency reuse is adopted. For example, when some frequencies in the MA list are adjacent, adjacent-channel interference occurs if the channels with the same timeslot number but on different TRXs use adjacent MAIOs and are occupied at the same time. When dynamic MAIO is enabled, the MAIO value is dynamically adjusted according to the current interference and the MAIO value with the minimum interference is assigned to the channel. Therefore, the call has the minimum interference from the perspective of the entire network. Huawei BSS equipment records the interference on each timeslot and updates the record during each channel activation or channel release.

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Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-113701 Frequency Hopping (RF hopping) This feature and the following feature are mutually exclusive: GBFD-117002 IBCA (Interference Based Channel Allocation) GBFD-118106 Dynamic Power Sharing GBFD-115830 VAMOS Dependency on other NEs None

7.2.5 GBFD-115801 ICC Availability This feature was introduced in GBSS6.1.

Summary When combining the signals from multiple antennas, the interference counteract combine (ICC) uses interference correlation of different antennas to eliminate some interference.


Improves the voice quality and data throughput in the scenarios with severe interference, for example, where tight frequency reuse is applied, improving user experience.



Improves the anti-interference capability of equipment and increases the system capacity.

Description ICC is a technology that suppresses the interference by combining signals of multiple antennas. Generally, the interference on different antennas is generated by the same interference source. Therefore, the interfering signals received by different antennas have a certain correlation. ICC uses this correlation when combing signals to eliminate some

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interference. In this way, ICC improves the anti-interference capability of equipment and increases the uplink coverage and receiver sensitivity. ICC can suppress the interference within the GSM system and from other systems only if the interference on different antennas has a correlation. Huawei BSS supports dual-antenna ICC and four-antenna ICC.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature should be used in a synchronous network. GBFD-118201 Soft-Synchronized Network GBFD-118620 Clock over IP Support 1588v2 GBFD-510401 BTS GPS Synchronization Dependency on other NEs None

7.2.6 GBFD-115821 EICC Availability This feature was introduced in GBSS8.1.

Summary The interference on the signals received by multiple antennas has both spatial correlation and temporal correlation: co-channel interference (CCI) and inter-symbol interference (ISI). After considering the correlation of these two types of interference, EICC combines the signals received by multiple antennas to provide better signal quality on the uplink.


The EICC feature improves the uplink signal quality to meet the requirements for radio communications and to improve the uplink performance in scenarios with wide coverage.



With the uplink anti-interference capability improved, tight frequency reuse can be achieved and therefore the system capacity is increased.

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Description Similar to ICC, EICC mainly applies to the network where the tight frequency reuse pattern is adopted and the traffic volume is heavy. The interference on the signals received by multiple antennas has both spatial correlation and temporal correlation: CCI and ISI. Considering the spatial correlation and temporal correlation of the interference, ICC eliminates these two types of interference independently. EICC, however, considers the correlation of these two types of interference and constructs the multidimensional combining coefficient matrix to combine the signals according to the maximum signal-to-noise ratio (SNR) criteria. In this way, EICC obtains the optimized uplink signals. EICC requires the matrix of interference, which is calculated on the basis of the training sequence of wanted signals. For each RX signal, the network estimates a channel model based on the training sequence of the signal, reconstructs the wanted signal, and subtracts the wanted signal from the RX signal to obtain the interfering signal. The network then estimates the matrix of each interfering signal and analyzes the statistical dependency of these interfering signals. Based on the statistical dependency, some interference is counteracted during the combination of RX signals to maximize the combination gain.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature should be used in a synchronous network. This feature should be used with the following features: GBFD-118201 Soft-Synchronized Network GBFD-118620 Clock over IP Support 1588v2 This feature is mutually exclusive with the following features: GBFD-510101 Automatic Frequency Correction (AFC) Dependency on other NEs None

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7.2.7 GBFD-113701 Frequency Hopping (RF hopping, baseband hopping) Availability This feature was introduced in GBSS6.1.

Summary With this feature, wanted signals are transmitted by switching a carrier among many frequencies according to the specified sequences. Frequency hopping involves RF hopping and baseband hopping.


This feature reduces the co-channel and adjacent-channel interference and therefore improves the voice quality of the network.



The tight frequency reuse pattern can be adopted to increase the system capacity.



This feature improves the information security.

Description With this feature, a traffic carrier frequency hops along the time according to the specified sequence. Frequency hopping involves RF hopping and baseband hopping in terms of implementation of the TRX. The frequency hopping enables operators to adopt the tight frequency reuse pattern, increasing the system capacity while maintaining the good voice quality. The frequency hopping feature minimizes the interference on a channel from the same interference source. Therefore, it is widely used in the communications system because it helps improve the anti-attenuation capability, anti-interference capability, and information security. In RF hopping, the frequencies for both transmitter and receiver of the TRX participate in frequency hopping. The number of frequencies participating in the FH can exceed the number of TRXs in the cell. RF hopping is implemented through the real-time switchover between two frequency synthesizers. RF hopping has the following advantages: 

RF hopping lowers the speed requirements on the frequency synthesizer.



When there is no FH, the two frequency synthesizers work in backup mode, enhancing the system reliability.



RF hopping avoids the impact of the fast frequency conversion on the signal quality, and therefore realizes the FH of all frequencies on the supported frequency band.

In baseband hopping, each transmitter works on a fixed frequency, and the TX does not participate in FH. The TX frequency hopping is achieved though the switching of baseband signals. The RX of the TRX, however, must participate in FH. Therefore, the number of frequencies participating in FH in a cell must be less than or equal to the number of TRXs assigned for the cell. When a TRX is faulty, the system enables the baseband FH TRX cooperation to ensure that the voice quality in the cell is not affected by the faulty TRX.

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Enhancement GBSS9.0 Optimization of Baseband FH TRX cooperation: In the baseband FH cell, if the TRX involved in baseband FH is faulty, remove the faulty TRX from baseband FH group and continue FH with the good running TRX. Meanwhile the same mechanism will take effect when main BCCH TRX cooperation happen, it will still remain hopping with the baseband TRX. GBSS12.0 Support RF hopping and baseband hopping at the same time in one cell

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features Base band hopping is mutually exclusive with the following features: GBFD-111604 Intelligent Combiner Bypass GBFD-111606 Power Optimization Based on Channel Type GBFD-118101 Dynamic Transmit Diversity GBFD-118102 Dynamic PBT (Power Boost Technology) Dependency on other NEs None

7.2.8 GBFD-113702 BCCH Carrier Frequency Hopping Availability This feature was introduced in GBSS6.1.

Summary With this feature, non-BCCH timeslots participate in the baseband hopping, improving the radio quality of non-BCCH timeslots and the cell performance.

Benefits This feature helps improve the radio quality of non-BCCH timeslots on the BCCH carrier.

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Description In Huawei BSS, the non-BCCH timeslots on the BCCH TRX can participate in baseband hopping in the cell. In this way, the baseband hopping performance is improved because the number of frequencies participating in FH increases, and the performance of non-BCCH timeslots on the BCCH TRX is improved because they also participate in the FH. For the FH that the BCCH carrier participates in, the BCCH timeslot is not involved, but the rest timeslots can participate in the baseband hopping. According to the GSM specifications, the BCCH must be carried on a fixed frequency to ensure the cell selection, cell reselection, and handover measurement. Therefore, the BCCH carrier cannot participate in the RF hopping.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following feature: Baseband hopping in GBFD-113701 Frequency Hopping (RF hopping, baseband hopping) This feature and the following feature are mutually exclusive: RF hopping in GBFD-113701 Frequency Hopping (RF hopping, baseband hopping) Dependency on other NEs None

7.2.9 GBFD-113703 Antenna Frequency Hopping Availability This feature was introduced in GBSS7.0.

Summary Similar to the baseband frequency hopping, the antenna frequency hopping enables the data of all the timeslots on a specific carrier to be transmitted in turn on the antennas of other TRXs in the cell. In this way, the space diversity is increased and the quality of the TRX data received by the MS is improved, and therefore the network performance is improved.


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

Increases the space diversity and improves the quality of BCCH TRX data received by the MS, improving the network performance and reducing the network interference.



Increases the network capacity. Compared with the non-FH or FH with a few frequencies, the antenna frequency hopping can increase the radio network capacity by up to 30% and the network diversity gain by up to 3 dB.

Description Similar to the baseband frequency hopping, the antenna frequency hopping enables the data of all carriers to be transmitted in turn on the antennas of other TRXs in the cell. This feature applies to the BCCH on the BCCH TRX. The BCCH must be transmitted on the same frequency. Therefore, the BCCH cannot hop by baseband hopping or RF hopping. In a GSM cell, however, the frequency, frame number, system information, and paging group are transmitted on the BCCH of the BCCH TRX. These broadcast messages are important for the MS in idle mode to search for a network and for the MS in dedicated mode to measure the neighboring cell. If the MS is located in a place where it is difficult to receive the messages from the BCCH TRX or if the antenna for the BCCH TRX is damaged, then the MS cannot properly receive the broadcast control messages from the BCCH TRX. Similar to the baseband frequency hopping, the antenna frequency hopping enables the data of all timeslots on the BCCH TRX to be transmitted in turn on antennas of other TRXs. This increases the space diversity of the BCCH signals and improves the quality of the data received by the MS from the BCCH TRX, improving the network performance. For example: If a cell is configured with three TRXs and each TRX connects to one antenna with the antenna frequency hopping enabled, the data of TRX 0 may be transmitted on antenna 1 at this instant and on antenna 0 at the next instant, and then on antenna 2 at the third instant. In this way, the space diversity is realized and therefore the receiver performance of the MS is improved.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It is mutually exclusive with the following features: GBFD-111602 TRX Power Amplifier Intelligent Shut down (in GBS9.0 and former version; DRRU/DRFU support GBFD-111602 from GBSS12.0) GBFD-510104 Multi-site Cell GBFD-118104 Enhanced EDGE Coverage GBFD-111604 Intelligent Combiner Bypass Issue V0.5 (2011-08-30)


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GBFD-111606 Power Optimization Based on Channel Type GBFD-118101 Dynamic Transmit Diversity GBFD-118102 Dynamic PBT (Power Boost Technology) Dependency on other NEs The BTS must support this feature, and at least two antennas are required in a cell to enable antenna frequency hopping.

7.2.10 GBFD-118001 BCCH Dense Frequency Multiplexing Availability This feature was introduced in GBSS8.0.

Summary This feature allows the operator to adopt the tight frequency reuse pattern for the frequencies of the BCCH carriers.


The number of frequencies occupied by the BCCH carriers reduces, improving the frequency usage. In addition, the number of frequencies available for the TCHs and the number of frequencies participating in FH on the TCH increase, increasing the system capacity and reducing the costs of adding sites and cells.



The TCHs on BCCH carriers are assigned to only the MSs near the BTS, improving the voice quality because of less uplink interference.

Description Each cell is configured with a BCCH carrier, and timeslot 0 on the BCCH carrier is used to carry the BCH and CCCH. This timeslot continually sends messages to all the MSs camping on the cell. The messages include the synchronization message, system information, paging message, and assignment message, which are directly related to cell selection, cell reselection, call initiation, and paging response. Therefore, the BCCH becomes the most important channel in GSM communications. Generally, the 4x3 pattern is adopted for the BCCH frequencies. This can ensure a high carrier-to-interference ratio (CIR) between BCCH carriers. In this pattern, however, the BCCH carriers occupy 12 frequencies. In a network with tight frequency reuse and limited frequency resources, if the 3x3 pattern is used for the BCCH frequencies, the interference to the TCH on the BCCH carrier increases and the performance degrades to an unacceptable level. This feature enables the BCCH frequencies to adopt the tight frequency reuse pattern. In this way, in the network with limited frequency resources, the number of frequencies occupied by the BCCH carriers decreases and the number of frequencies available for the TCHs increases, increasing the system capacity without adding hardware and reducing the costs of adding sites.

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This feature regards a cell as two logical layers: TCH layer on BCCH carriers and FH layer on other carriers. The FH layer serves the entire system and covers the entire network, including the MSs at the boarder of a cell. The TCH layer on the BCCH carrier, however, provides limited coverage to ensure the performance of call access. The interference in the area near the BTS is smaller than that in the area far from the BTS and at the edge of the cell. Therefore, the TCH layer on the BCCH carrier provides the coverage only for the MSs near the BTS. During the initial access and channel assignment triggered by handover (non-BCCH tight frequency multiplexing), the system preferentially assigns TCHs on the non-BCCH carriers to ensure the access performance. If a call is assigned a TCH on a non-BCCH carrier in the cell, the BCCH Dense Frequency Multiplexing feature has less impact on the call if the MS is near the BTS. The system then hands over the call to a TCH on the BCCH carrier and reserves the channels on the non-BCCH carrier to ensure the access performance of other calls.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature and the following feature are mutually exclusive: GBFD-113201 Concentric Cell GBFD-114501 Co-BCCH Cell GBFD-114401 Multi-band Sharing One BSC Dependency on other NEs None

7.2.11 GBFD-117002 IBCA (Interference Based Channel Allocation) Availability This feature was introduced in GBSS8.1.

Summary When the network accesses a new call, the interference between the established calls and the new call is calculated. Based on the calculation result, the network assigns a channel with the minimum interference to the new call. This minimizes the overall interference in the network and therefore enables a tighter frequency reuse pattern. This increases the network capacity while maintaining the voice quality in the entire network.

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Effectively improves the frequency usage and therefore improves the network capacity.

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Reduces the overall interference and therefore improves the network performance.

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Improves the voice quality of calls.

Description In the GSM network, the loose frequency reuse provides better network performance, higher network KPIs, and excellent voice quality, but reduces the network capacity compared with the tight frequency reuse. The tight frequency reuse pattern can increase the network capacity, but also increases the probability that the TRXs use the same frequency or adjacent frequencies. This results in more co-channel or adjacent-channel interference, degrading the network performance. Based on the timeslot synchronization on the Um interface, the IBCA feature considers only the channel-level interference. During the channel assignment, the IBCA considers the interference strength of all idle channels and then preferentially assigns the channel with the minimum interference. The IBCA feature involves the following functions: 

Calculation of the interference to the new call caused by the established calls The IBCA must be used together with frequency hopping. The idle channels with different MAIOs transmit signals on the Um interface with different frequencies, and therefore the interference that the idle channels experience from the established calls varies. The IBCA calculates the interference strength on each idle channel when different MAIOs are applied.



Calculation of interference to the established calls caused by the new call The established calls cause interference to the new call. Similarly, the new call causes interference to the established calls once it accesses the network. The IBCA estimates the CIR of the new call to the established calls.

Considering the preceding two types of interference, the IBCA-enabled network assigns the channel and MAIO with the minimum interference to the new call. The IBCA feature consists of intra-BSC IBCA and inter-BSC IBCA. That is, the IBCA-enabled cells may belong to one BSC or multiple BSCs. The IBCA feature improves the frequency usage and therefore effectively increases the network capacity. In addition, the IBCA-enabled network considers the interference to the new call caused by the established calls, improving the voice quality of calls. The network KPIs may be affected after the IBCA is applied. For example, the call drop rate increases or the handover success rate decreases. Operators need to purchase Huawei's professional services to minimize the impact of introducing IBCA on network KPIs.

Enhancement GBSS12.0 IBCA Enhancement: The limitation on the frequency hopping (FH) in an IBCA-enabled cell is lifted. The limitation was that an IBCA-enabled cell can be configured with a maximum of three MA groups and each MA group be configured with a maximum of 12 frequencies. After this

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enhanced feature is enabled, the numbers of MA groups and frequencies are restricted only by the BSC memory for cell information. This feature is suitable for sites with a large number of frequencies.

Dependency Dependency on BSC hardware Embedded PCU should be used. Service processing boards should be added for processing the IBCA-related services. The IP interface board should be added for the inter-BSC IBCA. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-118201 Soft-Synchronized Network or GBFD-510401 BTS GPS Synchronization GBFD-113701 Frequency Hopping (RF hopping, baseband hopping) GBFD-117601 HUAWEI III Power Control Algorithm GBFD-118621 Connection Inter BSC over IP (When IBCA of Inter-BSC is supported) This feature and the following feature are mutually exclusive: GBFD-113701 Frequency Hopping (baseband hopping) GBFD-110607 Direct Retry GBFD-117001 Flex MAIO GBFD-118001 BCCH Dense Frequency Multiplexing Dependency on other NEs None

7.2.12 GBFD-118201 Soft-Synchronized Network Availability This feature was introduced in GBSS8.0.

Summary When Soft-Synchronized Network feature is enabled, all the BTSs under a BSC synchronize with each other by adjusting the frame number, timeslot number, and bit offset in the timeslot to be the same through software. In a synchronous network, dynamic frequency allocation and dynamic channel assignment can be adopted to minimize inter-cell co-channel and adjacent-channel collision. This greatly improves the frequency usage and increases the network capacity.


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This feature synchronizes all the BTSs under a BSC through software without additional hardware devices.

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After the BTSs are synchronized, the IBCA feature can be implemented. The IBCA enabled in the synchronous network can improve the network capacity by 20% to 50%.

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After the BTSs are synchronized, the performance of technologies such as ICC and SAIC can be greatly improved. The ICC enabled in the synchronous network can improve the network performance by about 5.5 dB compared with the performance in the asynchronous network, and the SAIC enabled in the synchronous network can increase the network capacity by about 40%.

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This feature improves the KPIs such as MOS, paging success rate, handover success rate, call drop rate, and traffic volume.

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This feature realizes the software synchronization with the reference BTS, enabling the flexible networking and reducing the workload of synchronization.

Description Most of the existing networks work in asynchronous mode. That is, all BTSs are not synchronized, and each BTS adopts a different frame number, timeslot number, and offset. There are two network synchronization modes: hardware synchronization and software synchronization. 

In hardware synchronization mode, each BTS is equipped with a GPS device to realize the network synchronization through the satellite. This requires expensive hardware devices.



The Soft-Synchronized Network feature realizes the synchronization through software. This feature enables all the BTSs under a BSC to synchronize with each other by adjusting the frame number, timeslot, and bit offset to be the same through software.

In the asynchronous network, the system cannot estimate the adjacent-channel interference but only can reduce the interference by using the functions such as loose frequency reuse and frequency hopping. In the synchronous network, the system estimates the co-channel and adjacent-channel interference in any inter-cell overlapping area and minimizes inter-cell co-channel and adjacent-channel collision by adopting the dynamic frequency allocation and dynamic channel allocation. This greatly improves the frequency usage and increases the network capacity. In the synchronous network, the ICC and SAIC achieves the optimal performance. When wanted signals are synchronized with interfering signals in time, the interfering signals are the same in the entire burst. The interference estimated on the basis of the training sequence can effectively counteract the interference during the burst. In this case, the ICC and SAIC provide the optimal performance. The Soft-Synchronized Network feature needs to be used together with the GBFD-117002 IBCA feature to avoid the inter-cell co-channel and adjacent-channel interference. This greatly improves the frequency usage and increases the network capacity. The Soft-Synchronized Network feature can be deployed at TDM network (including Abis IP over E1/T1), while the IP network is not. The Soft-Synchronized Network feature can only be used for Abis interface using TDM transmission network (including Abis IP over E1/T1), cannot apply Abis interface using Ethernet networking scene.

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The Soft-Synchronized Network feature is applicable to the scenario where the end-to-end communication between the BSC and BTS is based on TDM, such as Abis TDM over E1/T1/STM-1 and Abis IP over E1/T1/STM-1. When the Ethernet network is used between the BSC and BTS, that is, Abis IP over FE / GE, the Soft-Synchronized Network feature is not supported.

Enhancement GBSS8.1 Inter-BSC soft-synchronized network: software synchronization of BTSs under multiple BSCs Multiple-reference soft-synchronized network: In the system, some BTSs are synchronized through hardware and others are synchronized through software to enable the flexible networking. When the network replanning and upgrade are required, the enhanced feature fully utilizes the existing resources to realize synchronization, reducing the workload of synchronization and saving the costs.

Dependency Dependency on BSC hardware IP interface is needed to support Inter BSC Soft-Synchronized Network. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It depends on the following features: GBFD-118621 Connection Inter BSC over IP It is mutually exclusive with the following features: GBFD-118601 Abis over IP GBFD-510104 Multi-site Cell In the network of using GBFD-118201 Soft-Synchronized Network or GPS for synchronization, it is recommended working with the following features: GBFD-115801 ICC GBFD-115821 EICC GBFD-118103 Network Support SAIC Dependency on other NEs None

7.2.13 GBFD-510401 BTS GPS Synchronization Availability This feature was introduced in GBSS8.0.

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Summary The BTS supports the GPS synchronization through a satellite.


The frame synchronization on the Um interface in the entire network by using the GPS provides high synchronization precision and easy implementation.



When the network works in synchronous mode, the features such as ICC and IBCA can be used to increase the network capacity by more than 40%.



This feature improves the KPIs such as mean opinion score (MOS), paging success rate, handover success rate, call drop rate, and traffic volume.

Description In the existing GSM system, the BTSs work in asynchronous mode, resulting in timeslot overlapping. In the asynchronous network with the tight frequency reuse pattern, the overlapping of timeslots causes unnecessary and unpredictable interference because the frequency reuse distance between two cells using the same frequency is relatively short. The interference (that is, channel quality) rather than the number of channels restricts the network performance. Therefore, the BTSs in the entire network synchronize with each other based on the reference clock signals provided by the GPS satellite. The GPS clock system of the BTS receives the related information sent by the GPS satellite and then obtains the GPS absolute time and precise 1PPS pulse signals. The BTS clock circuit traces the 1PPS pulse signals to obtain the reference clock and then obtains various clock signals based on the reference clock. Each BTS in the network adjusts the frame number based on the absolute frame number calculated from the GPS absolute time received by the BTS software.

Enhancement Each BTS is equipped with a GPS for hardware synchronization of the entire network, which increases the costs. Therefore, the Soft-Synchronized Network feature, which is an optional feature, is introduced to GBSS8.0 to realize the frame synchronization on the Um interface through software. For details, see the GBFD-118201 Soft-Synchronized Network feature.


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7.2.14 GBFD-113706 Mega BSC Availability This feature is introduced in GBSS14.0.

Summary With this feature, a BSC supports a maximum of 8192 TRXs and 45,000 erlang of traffic volume when IP over FE/GE is used over the A, Abis, and Gb interfaces.


Enables a BSC to support more subscribers while maintaining the speech quality.



Improves the BSC equipment integration, which helps reduce the number of BSC nodes, the footprint in the equipment room, and the power consumption per TRX.

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Simplifies BSC parameter settings, which improves the network maintenance efficiency.

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Reduces the number of inter-BSC handovers and cell reselections, which improves network performance.

Description With this feature, the improved specifications are as follows: Item

Specification

Number of TRXs

8192

Traffic volume

45,000 (erlang)

Busy hour call attempts (BHCAs) for a CS+PS composite service

11,000,000

Number of users

2,200,000

Circuit identification codes (CICs) on the A interface

61,440

Number of PDCHs that can be activated

32,768

PS traffic throughput

3072 (Mbit/s)

1.

If TDM over FE/GE is used over the A, Abis, and Gb interfaces, the TRX supporting capacity remains unchanged, that is, a BSC supports a maximum of 4096 TRXs.

2.

If both IP and TDM transmission modes are used, the maximum number of TRXs supported by TDM-based BTSs is 4096, and the maximum number of TRXs supported by the BSC is less than 8192, depending on the number of configured TRX boards.

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The system specification (a maximum number of 2048 BTSs and 2048 cells) remains unchanged.

Enhancement None

Dependency Dependency on BSC hardware The BSC6900 must be configured with the following boards: DPUf, DPUg, XPUb, FG2c, GOUc, SCUb, and OMUc. In addition, IP over FE/GE must be used over the A, Gb, and Abis interfaces. Dependency on BTS hardware None Dependency on other GBSS features None Dependency on other NEs None

7.3 High Speed Mobility 7.3.1 GBFD-510101 Automatic Frequency Correction (AFC) Availability This feature was introduced in GBSS6.1.

Summary The automatic frequency correction (AFC) feature uses a special balancing algorithm to estimate the difference between the standard frequency and the frequency of the GMSK-coded signal sent from the fast-moving MS to the BTS. The AFC estimates the frequency offset between the frequency of each received burst and the standard frequency in real time. Then, the estimated frequency offset is used to correct the RX working frequency of the BTS.

Benefits This feature improves the decoding performance of the physical link in the uplink in the fast moving condition, ensuring the physical transmission performance and reliable connections between the fast-moving MS and the BTS. In addition, this feature enables the system to support a telecommunication environment with a speed higher than 500 km/h, which serves as the basis of the high-speed frequency offset handover algorithm.

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Description AFC is a BTS frequency correction algorithm designed for fast-moving MSs. This algorithm ensures reliable radio links and continuous services with good voice quality when the MS moves at a speed of 500 km/h. According to Doppler frequency shift principle, the frequency of the signals sent by the fast-moving MS shifts. The frequency shift information is related to the moving speed and direction of the MS relative to the BTS. The BTS digital signal processor uses a special balancing algorithm to estimate the difference between the standard frequency and the frequency of the GMSK-coded signal sent from the fast-moving MS to the BTS. The AFC estimates the frequency offset between the frequency of each received burst and the standard frequency in real time. Then, the estimated frequency offset is used to correct the RX working frequency of the BTS. This feature improves the decoding performance of the physical link in the uplink in the fast moving condition, ensuring the physical transmission performance and reliable connections between the fast-moving MS and the BTS. The performance of AFC depends on the vertical distance between the BTS and the railway. The shorter the vertical distance is, the faster the change of the frequency offset is when the train approaches the BTS. Therefore, the AFC loop cannot keep pace with the change of frequency offset, leading to a great residual frequency offset. Simulation results show that the frequency offset smaller than 100 Hz has little impact on the demodulation performance. Therefore, when the TRX is on the GSM900 band and the speed of the train is 600 km/h, only the vertical distance of more than 100 m is supported if the loop bandwidth is 2 Hz. In the case of a lower demand for the voice quality, the vertical distance between the BTS and the railway can be shorter.

Enhancement GBSS12.0 Common AFC corrects only uplink frequencies so that the BTS can correctly demodulate uplink signals. The downlink signals from the BTS to the MS also encounter Doppler frequency shift. Most MSs, however, do not have the frequency correction function. The downlink AFC function enables the BTS to pre-compensate downlink signals for frequency offset based on the estimated uplink frequency offset so that the frequency offset of the downlink signals received by the MS is zero.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It is mutually exclusive with the following features: GBFD-114001 Extended Cell GBFD-115821 EICC GBFD-115830 VAMOS

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7.3.2 GBFD-510102 Fast Move Handover Availability This feature was introduced in GBSS6.1.

Summary This feature enables better cell handover in a short period of time.

Benefits Generally, the chain cell algorithm is not used because of the special characteristics of the railway and highway users. This may lead to slow handover or call drops during handover. With this feature, the handover success rate in the fast-moving condition is increased and therefore the subscriber satisfaction is increased.

Description In a fast-moving train, it takes a short time for an MS to move across a cell. Therefore, a handover must be performed quickly. To reduce the handover failure rate, a handover must be quickly initiated when required. If the handover fails (for example, when the radio interface suddenly incurs interference), a second handover must be quickly initiated. The fast PBGT handover algorithm enables better cell handover in a short period of time. Compared with the existing PBGT handover algorithm, the fast PBGT handover algorithm has the following advantages: 

Handing over an MS to a proper target cell by predicting the moving direction of the MS



Accelerating the handover decision to improve the handover rate

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following feature: GBFD-510103 Chain Cell Handover Dependency on other NEs

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None

7.3.3 GBFD-510103 Chain Cell Handover Availability This feature was introduced in GBSS6.1.

Summary This feature enables the fast-moving MS to be preferentially handed over to the chain neighboring cell.

Benefits This feature increases the handover success rate in the fast-moving condition and therefore increases the subscriber satisfaction.

Description By predicting the moving direction of a fast-moving MS, this feature enables the fast-moving MS to be handed over between two chain neighboring cells. Therefore, the handover success rate is increased and the network quality is improved. Chain neighboring cells ensure reliable handovers between cells. 

Chain neighboring cells are formed on the basis of the linear coverage characteristic of the fast-moving environment such as the railway.



A handover to a chain neighboring cell is preferred. In addition, handover to the moving direction of the user should be guaranteed.

Enhancement None


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7.3.4 GBFD-510104 Multi-site Cell Availability This feature was introduced in GBSS8.1.

Summary This feature enables the subsites in different physical sites to be set to a logical cell, which is also called a cascading cell. A subsite refers to a certain area physically covered by multiple RRU/RFUs that belong to the same BBU. In the scenarios such as railway, tunnel, or indoor coverage, a cascading cell can reduce handovers, improve the coverage efficiency, and enhance the user experience.


This feature reduces handovers between cells and increases the handover success rate.



A cascading cell increases the effective coverage distance of each subsite and improves the coverage efficiency of the entire cell because few handover areas are required between different subsites.

Description Cell cascading means that different subsites in the same BBU physically belong to different sites but logically belong to the same cell. The principle is shown in the following figure.

Cascading cells are carried in multiple subsites. These subsites have the same cell parameters such as physical configurations, the number of TRXs, and frequencies. One cascading cell has only one primary subsite responsible for cell management and service control. Other subsites are secondary subsites. Under the control of the primary subsite, these secondary subsites

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implement cell service functions such as the selection of available TRXs and the activation of channels. During the initial access of an MS, all the subsites calculate the uplink signal noise ratio (SNR) of the MS respectively and report the result to the primary subsite. Then the primary subsite selects the subsite with the optimal SNR as the serving subsite. All the subsites continuously calculate the uplink SNR of the MS and then report the SNR to the primary subsite. When the SNR reported by an adjacent subsite is better than the SNR reported by the serving subsite, the handover between subsites is triggered. When the MS is handed over between subsites, the new subsite is connected and then the old subsite is disconnected without the interruption of services. In this manner, seamless handover is implemented and the QoS is guaranteed.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature cannot be used with the following features: GBFD-111602 TRX Power Amplifier Intelligent Shutdown GBFD-118201Soft-Synchronized Network GBFD-113703 Antenna Frequency Hopping GBFD-115830 VAMOS GBFD-111612 Multi-Carrier Intelligent Voltage Regulation This feature cannot be used with the following features in GBSS12.0 and its earlier versions: GBFD-118601 Abis over IP GBFD-118611 Abis IP over E1/T1 Dependency on other NEs None

7.3.5 GBFD-510105 PS AFC Availability This feature is introduced in GBSS14.0.

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Summary PS Automatic Frequency Control (AFC) applies to PS services that use Gaussian Minimum Shift Keying (GMSK) or 8 Phase Shift Keying (8PSK) and are processed along high-speed railways. PS AFC estimates the frequency offset for each burst by using frequency discrimination. Based on the frequency offset, PS AFC corrects the frequency of baseband signals before whitening filtering, and then the signals whose frequencies are corrected are used for demodulation. This feature improves the demodulation performance of uplink high-order PS services from MSs that are moving at least 200 km/hour (GSM900) or at least 100 km/hour (DCS1800). Applying this feature on services from MSs that are moving at a low rate of speed, however, will deteriorate the demodulation performance.


Improves the throughput of uplink Enhanced Data Rates for Global Evolution (EDGE) services.



Decreases the demodulation threshold for uplink EDGE services.

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Decreases the EDGE data block retransmission rate.

Description PS AFC has three procedures: frequency discrimination, frequency correction, and time resynchronization and channel estimation. The AFC process is described as follows: 1. PS AFC performs frequency discrimination on the IQ data of a burst before whitening filtering as follows: After reconstructing reference receive signals based on the local training sequence and the Channel Impulse Response (CIR), the PS AFC module performs the correlation operation and cross product on the receive signals and the reference receive signal to estimate the frequency offset. If the estimated frequency offset is less than or equal to 1000 Hz (GSM900)/2000 Hz (DCS1800), the estimated value is used. If the estimated frequency offset is greater than 1000 Hz (GSM900)/2000 Hz (DCS1800), the value 1000 Hz (GSM900)/2000 Hz (DCS1800) is used. 2. PS AFC corrects the frequency of the IQ data for this burst before whitening filtering. 3. PS AFC performs time resynchronization and Least Square (LS) channel estimation on the IQ data after frequency correction. The length of the CIR used during time resynchronization and LS channel estimation is calculated by the CIR length adaptive module. If PS AFC is enabled, the IQ data and CIR after AFC are used. If PS AFC is disabled, the IQ data and CIR before AFC are used. If PS AFC is disabled, PS services using Modulation and Coding Scheme 5 (MCS5) are unavailable for MSs moving faster than 350 km/hour because the demodulation performance is poor. If PS AFC is enabled, PS services using MCS5 reach the peak throughput when the Signal-to-Noise Ratio (SNR) is greater than 10 dB. Applying PS AFC increases the throughput of PS services using MCS1 by 25% to 100% for MSs moving 550 km/hour and with an SNR of 2 dB to 6 dB. The throughput of these PS services is inversely proportional to the SNR. The preceding moving speed applies to MSs that work at GSM900. The speed for MSs that work at GSM1800 is reduced by 50%.

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Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature and the following feature are mutually exclusive: GBFD-115821 EICC Dependency on other NEs None

7.4 Intra-System Mobility Management 7.4.1 GBFD-510501 HUAWEI II Handover Availability This feature was introduced in GBSS8.1.

Summary HUAWEI II handover algorithm is optimized from HUAWEI I handover algorithm. HUAWEI II handover algorithm takes all results of handover decisions into account, obtaining more accurate results of handover decisions.

Benefits This feature improves the accuracy of the handover decision and increases the handover success rate. This feature enhances the network quality and improves the network KPIs.

Description HUAWEI II handover algorithm takes account all results of handover decisions and candidate cell list, and then generates the handover execution policy. HUAWEI II handover algorithm is categorized into three handover algorithms: emergency handover (directed retry, frequency offset handover, bad quality handover, TA handover, and edge handover), intra-cell handover (interference handover, BCCH tight frequency multiplexing in concentric cell, AMR handover), inter-cell handover (better cell handover, enhanced dual band network handover, fast-moving handover, and GSM-to-3G inter-RAT

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handover). All handover decisions are traversed in the handover decision phase. Unlike common handover algorithms, HUAWEI II handover algorithm is not performed immediately if the triggering condition of a handover is met during the traverse. But only the candidate target cell lists with handover decision type are generated independently. After all handover decisions are traversed, HUAWEI II handover algorithm takes the intersection from the candidate target cell lists corresponding to the handovers that meet the triggering condition, and then generates the final target cell list for the handover. Compared with common handover algorithms, HUAWEI II handover algorithm takes all results of handover decisions into account, obtaining more accurate results of handover decisions.

Enhancement GBSS14.0 A handover penalty inheritance mechanism is added to the load handover. When a load handover is successful, the penalty cell list from the source cell is inherited and therefore ping-pong handovers are prevented.


7.4.2 GBFD-510502 Handover Re-establishment Availability This feature was introduced in GBSS8.1.

Summary On receiving the Error Indication message from the BTS during the handover process, the BSC does not regard it as a call drop directly and attempts to re-establish a call on the old channel.

Benefits Handover re-establishment provides the following benefits: 

Reduces the call drop rate and improving user satisfaction.



Improves network KPIs.

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Description In the handover process, the BSC sends the Handover Command message to the MS. Then, if the BSC does not receive any response from the MS but receives an Error Indication message from the BTS, the BSC regards it as a call drop. After handover re-establishment is applied, the BSC indicates that the BTS can re-establish a call on the old link over the Um interface after the BSC receives an Error Indication message on the old link. If the call re-establishment is successful, the MS makes calls on the old channel and no call drop occurs.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The BTS must support this feature.

7.4.3 GBFD-117501 Enhanced Measurement Report (EMR) Availability This feature was introduced in GBSS7.0.

Summary The EMR is a new downlink measurement report introduced in R99. Compared with the traditional MR, the EMR has more measurement-related information, such as the bit error probability (BEP) and frame erase ratio (FER). This facilitates the performance improvement of the power control algorithm and the handover algorithm.


Improves the capability of monitoring the voice quality, and the performance of the power control algorithm and the handover algorithm.



Provides better performance for GSM/WCDMA/TD-SCDMA interoperability by supporting up to 15 neighboring 3G cells.

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Description The EMR is a new downlink measurement report introduced in R99. It is reported to the network by the MS. Compared with the MR, the EMR has the following advantages: 1. The EMR uses an optimized scheme of encoding the neighboring cell information and reports more neighboring cells than the MR. The MR provides up to six neighboring GSM cells whereas the EMR provides up to 15 GSM/WCDMA/TD_SCDMA neighboring cells. Therefore, the EMR provides better performance for the GSM/WCDMA/TD-SCDMA interoperability and ensures the service continuity. 2. The EMR is added with the BEP, which is used to identify the channel quality. BEP is estimated one burst after another. It reflects the current C/I, delay of signals, and velocity of the MS. In addition, BEP adopts the 5-bit encoding scheme whereas RXQUAL adopts the 3-bit encoding scheme. Therefore, compared with RXQUAL, BEP has higher precision, especially when the radio signal quality is poor. 3. The EMR is added with the number of speech frames that are correctly received, which is used to calculate FER. In comparison with RXQUAL that measures the radio signal, the measurement effect of EFR is better because it measures the encoding/decoding performance of the speech signal. RXQUAL should be replaced with BEP and FER for the power control algorithm and the handover algorithm that use RXQUAL to evaluate radio signal quality because BEP and FER can be used to improve the performance of those algorithms. According to 3GPP TS 44018, through the MI/2QUATER system information, the network can determine whether an MS should report the measurement information about the serving cell and neighboring cells through MR or EMR. This feature should be supported by MS. If EMR enabled, and MS cannot report accurately measurement items of EMR, like BEP and FER, the HO success rate may be dropped.

Enhancement None


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7.4.4 GBFD-117101 BTS Power Lift for Handover Availability This feature was introduced in GBSS7.0.

Summary Before sending the handover command to the MS, the BSC adjusts the transmit power of the BTS to the maximum value to prevent call drops due to rapid level drop.


Reduces call drops, increases handover success rate, and optimizes KPIs.



Improves voice quality, prolongs call duration, and increases the operators' revenue.

Description During the call, if the receive level drops rapidly, the handover is triggered to avoid call drops. The power control algorithm, however, may fail to adjust the MS and BTS power in time. Therefore, the MS fails to receive the handover command, which then causes call drops. Using the BTS power lift for handover feature, the BSC can adjust the transmit power of the BTS to the maximum value before sending the handover command to the MS to prevent call drops due to rapid level drop.

Enhancement None


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7.5 GSM & WCDMA Interoperability 7.5.1 GBFD-114301 GSM/WCDMA Interoperability Availability This feature was introduced in GBSS6.1.

Summary The BSS system supports the handover and reselection of MSs between the GSM network and the WCDMA network.

Benefits This feature enables the MS to roam and be handed over from the WCDMA network to the GSM network. This can solve the problem of insufficient coverage in the early stage of the WCDMA network development. With this feature, the GSM network can smoothly evolve to the WCDMA network, saving the operator's investment.

Description GSM/WCDMA interoperability refers to the handover and roaming of dual-mode MSs between the GSM network and the WCDMA network. Huawei BSS supports the handover and roaming of dual-mode MSs between the GSM network and the WCDMA network. The handover and roaming include the following situations: 

In idle mode, an MS roams from the GSM system to the WCDMA system.

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In idle mode, an MS roams from the WCDMA system to the GSM system.

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In busy mode, an MS is handed over from the GSM system to the WCDMA system.

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In busy mode, an MS is handed over from the WCDMA system to the GSM system.

This feature consists of the following functions: 

Roaming in idle mode Through PLMN reselection, an MS can be handed over from the GSM network to the WCDMA network, or from the WCDMA network to the GSM network. The selection of the GSM network or the WCDMA network is determined by the network operator. Usually the WCDMA MSs preferentially select the WCDMA network. The PLMN reselection can be scheduled on the MS. The reselection time is determined by the operator. To inform the MS of the information on the WCDMA neighboring cell, the GBSS system needs to add the description of the WCDMA neighboring cell to the system information. The system information 3 is modified to indicate whether the system information 2 quarter exists. The system information 2 quarter includes information about cell reselection, measurement, and WCDMA neighboring cell. Through system reselection, a WCDMA MS can be handed over to a neighboring GSM cell when the signal in the WCDMA network is weak.

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The handover from the WCDMA system to the GSM system is determined by the WCDMA network. When receiving the handover request from the MSC, the BSS works with the MSC to implement the handover based on the resource situation. Then, the MS in busy mode in the GSM cell measures the WCDMA neighboring cell based on the neighboring cell information in the system information and submits the measurement report to the BSC. The BSC then makes decisions according to the information in the measurement report and initiates inter-RAT handover when the requirements for the WCDMA cell handover are met. The cell reselection of the network-controlled MS from the GPRS/EDGE system to the WCDMA system is implemented by using the inter-RAT NC2 feature. The inter-RAT NACC feature can speed up the cell reselection from the WCDMA system to the GPRS/EDGE system.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The MS, MSC, SGSN, HLR, and the WCDMA-related NEs must support this feature.

7.5.2 GBFD-114321 GSM/WCDMA Service Based Handover Availability This feature was introduced in GBSS8.1.

Summary In a GSM-WCDMA co-sited network, the operator can classify services into different types according to the operation policies. Then, the operator determines whether a service preferentially uses the radio resources of the GSM system or the WCDMA system. During call access or the handover, the BSC works with the MSC to perform the handover from the GSM system to the WCDMA system.

Benefits With this feature, the advantages of the GSM system and the WCDMA system are fully utilized and therefore the service quality is improved and the user experience is enhanced. In

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addition, the operators' investment is saved and the utilization of the network resources is maximized.

Description With the application of the WCDMA system, the GSM-WCDMA co-sited network is widely in use. The service quality on the two radio access systems is different. Therefore, it is necessary to immediately use different system resources for different services. According to the service hierarchy principle, different services can be preferentially handed over to different systems. For example, the CS services are preferentially handed over to the GSM system whereas the PS services are preferentially retained in the WCDMA system. In the assignment procedure, the MSC sends the service handover information to the BSC through the ASSIGNMENT REQUEST message. If the service handover information indicates that the call should be preferentially processed in the UTRAN, the directed retry procedure is initiated to hand over the call to the WCDMA system. The HANDOVER REQUEST message received by the BSC may also carry the service handover information and the BSC uses this information for the subsequent handover decision.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following feature: GBFD-114301 GSM/WCDMA Interoperability Dependency on other NEs The MS, MSC, SGSN, HLR, and WCDMA-related NEs must support this feature.

7.5.3 GBFD-114322 GSM/WCDMA Load Based Handover Availability This feature was introduced in GBSS8.1.

Summary When the cell load in the GSM system is heavy, the BSC can initiate the handover from the GSM system to the WCDMA system based on the load of the GSM system and the WCDMA system to balance the overall load in the network, maximizing the utilization of the network resources.

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Benefits This feature balances the load of the WCDMA system and the GSM system, improving the service quality and the usage of the network resources.

Description With the application of the WCDMA system, the GSM-WCDMA co-sited network is widely in use. Therefore, the usage of the resources in the two radio access systems needs to be maximized. When the load of one radio access system is heavy whereas the load of the other radio access system with the same coverage is light, the load-based inter-RAT handover can be initiated to balance the load of the two systems if the services of the current user can be supported by the other system. The load information about the WCDMA system is transparently transmitted to the BSC through the MSC. Then the BSC determines whether to initiate the inter-RAT handover based on the load information about the WCDMA system and the load information about the BSC. Meanwhile, the load information about the BSC is carried in the handover request message for the reference of the target system during the inter-RAT handover decision.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following feature: GBFD-114301 GSM/WCDMA Interoperability Dependency on other NEs The MS, MSC, SGSN, HLR, and WCDMA-related NEs must support this feature.

7.5.4 GBFD-114323 GSM/WCDMA Cell Reselection Based on MS State Availability This feature was introduced in GBSS8.1.

Summary This feature is designed to optimize cell reselection from the GSM network to the 3G network (WCDMA network or TD-SCDMA network). It enables dual-mode MSs in the idle state or in

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the packet transfer state to adopt different reselection policies to access the GSM network or 3G network as required.


Helps the operator to determine whether to select the GSM or 3G network according to the network planning requirements when the MS is in the idle state or in the packet transfer state.

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Reduces the duration of service interruption caused by frequent cell reselection.

Description During the 3G network construction, operators need to select a proper network planning strategy for the MSs to select the GSM network or the 3G network based on the coverage of the 3G network and the compatibility of dual-mode MSs with the 3G network. This feature provides different cell reselection strategies based on the MS state. For example, in the early stage of the 3G network construction, operators expect that the 3G network can share some traffic of the GSM network. The data transmission of the MS in packet transfer mode, however, may be interrupted after cell reselection because the coverage of the 3G network is imperfect or the compatibility between the MS and 3G network is poor. In such a case, the KPIs deteriorate. In addition, the current 3GPP protocols do not support the NACC feature between the GERAN and the UTRAN. Therefore, the services of the MS in packet transfer state are inevitably interrupted during the inter-RAT cell reselection and therefore the quality of the PS services deteriorates. With this feature, operators allow the MS in idle mode to search for neighboring 3G cells by setting the parameter Qsearch_I to a specific value between 0 and 14. Similarly, operators can prohibit the MS in packet transfer mode to search for neighboring 3G cells by setting the parameter Qsearch_P to 15. In this manner, operators can control the MS's access to the GSM network or the 3G network according to the MS state. This feature and the Network-Controlled Cell Reselection (NC2) feature are mutually exclusive. With the NC2 feature, the MS in packet transfer state can select a neighboring 3G cell through the BSC's control of the inter-RAT cell reselection. With this feature, however, the MS in packet transfer state can be prohibited from selecting a neighboring 3G cell. This problem can be solved by configuring priorities for these two features.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following feature:

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GBFD-114301 GSM/WCDMA Interoperability or GBFD-114302 GSM/TD-SCDMA Interoperability Dependency on other NEs The MS must support this feature.

7.5.5 GBFD-114325 Fast WCDMA Reselection at 2G CS Call Release Availability This feature was introduced in GBSS9.0.

Summary When an MS terminates a call in the GSM network, it camps on the WCDMA network according to the cell selection indicator after release information in the Channel Release message instead of cell reselection from GSM to WCDMA.

Benefits The cell reselection of the MS is accelerated. The MS can obtain services from the WCDMA network immediately after the call is released from the GSM network.

Description In general, when the MS terminates a call in the GSM network, it camps on the cell in which the call is released and then starts the measurement related to the cell reselection. When a WCDMA neighboring cell meets the requirements for cell reselection, the MS camps on the WCDMA network after the cell reselection. The WCDMA cell reselection is initiated after the MS receives the system information and performs the related calculation. In this case, the time for the MS to access the WCDMA network is prolonged. When this feature is enabled, the BSS figures out the best WCDMA neighboring cell based on the measurement information on the WCDMA neighboring cells after the MS in the GSM network terminates a CS call. Then, the BSS sends the MS the frequency information on the cell through the Channel Release message to instruct it to camp on the WCDMA cell. In this way, the MS can camp on a WCDMA cell without related calculation, accelerating cell reselection

Enhancement None


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Dependency on other GBSS features None Dependency on other NEs The MS must support this feature.

7.5.6 GBFD-511101 Load Based Handover Enhancement on Iur-g Availability This feature was introduced in GBSS9.0.

Summary This feature is implemented through the exchange of Huawei proprietary IE containing load information over the Iur-g interface. The Iur-g protocol stack complies with the 3GPP specifications. With this feature, the decision on handover that is not caused by insufficient coverage can be more accurate, reducing the possibility of ping-pong handovers between the GSM network and WCDMA network.

Benefits This feature helps maintain a load balance between the GSM network and WCDMA network. It also helps increase the accuracy of handover decision, reducing the possibility of ping-pong handovers. The simulation results show that this feature reduces the percentage of invalid handovers between the GSM network and WCDMA network by up to 6 % and increases the total capacity of the GSM network and WCDMA network by up to 5%.

Description This feature functions as a supplement to GBFD-114322 GSM/WCDMA Load Based Handover. If the handover decision is based only on load, the occurrence of ping-pong handover is highly possible. The reason is that the mechanism of load information exchange between the GSM network and WCDMA network is inadequate. The inadequate mechanism may cause excessive services to be handed over from the GSM network to the WCDMA network, leading to the overload of the WCDMA network and consequently handover back to the GSM network. This feature enables the load information exchange over the Iur-g interface, so that the decision on load-based handover can be more rational. The conditions on which the decision is based are as follows: 

The target WCDMA cell meets the load requirements.

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The load difference between the source GSM cell and target WCDMA cell exceeds the predefined threshold.

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The handover will not lead to the congestion in the target WCDMA cell.

Enhancement None

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Dependency Dependency on MBSC hardware The Iur-g interface can be configured only on the FG2a/FG2c/GOUa/GOUc board. Dependency on MBTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS/RAN features This feature depends on the following feature: GBFD-114322 GSM/WCDMA Load Based Handover WRFD-070004 Load Based GSM and WCDMA Handover Enhancement Based on Iur-g Dependency on other NEs None

7.5.7 GBFD-511102 NACC Procedure Optimization Based on Iur-g between GSM and WCDMA Availability This feature was introduced in GBSS12.0.

Summary This feature enables the exchange of messages containing the RAN Information Management (RIM) information over the Iur-g interface between the RNC and BSC. The Iur-g protocol stack complies with the 3GPP specifications. In this way, the NACC procedure for PS services from a WCDMA cell to a GSM cell does not require the information transfer via the CN.

Benefits This feature provides a solution that enables the NACC procedure when the CN does not support the RIM procedure. The simulation results show that this feature helps shorten the delay of PS handover by two seconds. As the delay is shortened, the user experience can be improved.

Description As indicated in the 3GPP specifications, the GERAN (P) SI is obtained through the RIM procedure during the NACC procedure. The NACC procedure involves the RNC, WCDMA SGSN, GSM SGSN, and BSC. When this feature is applied, the GSM/WCDMA GERAN (P) SI information is transferred over the Iur-g interface between the base station controllers, without being transferred via the CN. This feature applies only to the Iur-g interface, which connects different base station controllers. In such a case, the GERAN (P) SI information is transferred over the protocol stack complying with the 3GPP specifications. If there is no Iur-g interface between WCDMA and GSM, the GERAN (P) SI information can be exchanged only via the CN, and accordingly

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the NACC procedure can be implemented only through the CN, as specified in the 3GPP specifications. The following figure shows the network topology that supports this feature. As shown in the figure, Huawei RNCs and BSCs are connected through the Iur-g interface. This feature applies to the BSC/RNC of other vendors only if it has passed the interoperability test (IOT). Otherwise, the CN-involved NACC procedure is applied. For the BSC/RNC of other vendors, the common cell reselection procedure is performed if the CN does not support the RIM procedure.

Enhancement None

Dependency Dependency on MBSC hardware The Iur-g interface can be configured only on the FG2a/FG2c/GOUa/GOUc board. Dependency on MBTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS/RAN features This feature depends on the following feature: WRFD-070005 NACC Procedure Optimization Based on Iur-g between GSM and WCDMA. Dependency on other NEs The NACC procedure must be supported by the MS/UE.

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7.5.8 GBFD-511103 GSM and WCDMA Load Balancing Based on Iur-g Availability This feature was introduced in GBSS12.0.

Summary This feature implements the load-based GSM/WCDMA handover through the exchange of Huawei proprietary IE over the Iur-g interface. With this feature, the traffic is distributed on the basis of the service handover indicator and load of the GSM network and WCDMA network when an MS accesses the network. In this way, a load balance is achieved between the GSM network and WCDMA network.

Benefits This feature aims at striking a load balance between the GSM network and WCDMA network. It reduces the possibility of congestion in areas covered by both GSM and WCDMA. The network utilization is consequently increased. The simulation results show that this feature reduces the percentage of invalid handovers between the GSM network and WCDMA network by up to 6 % and decreases the access congestion rate during busy hours by up to 4%.

Description As high-speed PS services are on great demand by a large number of GSM/WCDMA dual-mode handsets in well-established 2G/3G commercial networks, the load of WCDMA network has become increasingly heavy. Facing the situation, network operators focus on reducing the congestion rate and making full utilization of the present network capacity. This feature can efficiently address this issue. With this feature, the load balance between the GSM network and WCDMA network can be achieved. This helps reduce the possibility of network congestion and the percentage of invalid inter-RAT handovers. As a result, the capacity of both the GSM network and WCDMA network can be fully utilized. The following figure shows the applicable scenario where the GSM cell and WCDMA cell have the same coverage. In this scenario, this feature provides a load-balancing function for admitted MSs through the exchange of Huawei proprietary IE between the GSM cell and WCDMA cell.

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The load-balancing function is initiated after RAB setup. The GBSC/MBSC decides whether to hand over the requested CS service to the WCDMA network on the basis of the service handover indicator and the load difference between the GSM cell and the target WCDMA cell. The conditions on which the decision is based are as follows: 

The MS supports WCDMA services.

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The service handover indicator assigned by the CN or configured at the GBSC/MBSC shows that the CS service can be handed over to the WCDMA cell.

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The target WCDMA cell is lightly loaded.

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The load difference between the source GSM cell and target WCDMA cell exceeds the predefined threshold.

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The GBSC/MBSC determines whether to perform the inter-RAT handover on a number of MSs according to the predefined distribution rate. The rate is considered as a probability rate with respect to the redirection of a single MS. If the GBSC/MBSC determines that the handover is not performed, the CS service will be processed in the GSM cell.

This feature in the present version (GBSS12.0) applies to only the handover of CS services from a GSM cell to a WCDMA cell.

Enhancement None

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Dependency on other GBSS/RAN features This feature depends on the following feature: GBFD-114322 GSM and WCDMA Load Based Handover WRFD-070006 GSM and WCDMA Load Balancing Based on Iur-g Dependency on other NEs None

7.5.9 GBFD-511104 GSM and WCDMA Traffic Steering Based on Iur-g Availability This feature was introduced in GBSS12.0.

Summary This feature supports GSM/WCDMA handover based on service. With this feature, services are steered on the basis of the service handover indicator, hierarchical network planning, and the load of the GSM network and WCDMA network when an MS accesses the network.

Benefits This feature helps operators to develop network services in hierarchies, which facilitates the hierarchical network planning. With this feature, the spectrum utilization is increased. The simulation results show that this feature reduces the percentage of invalid inter-RAT handovers by up to 8% and increases the total capacity of the GSM network and WCDMA network by up to 8%.

Description In the case of evolution from a legacy GSM network to a GSM&WCDMA network, the WCDMA network usually has a larger capacity in the early stage. How to fully utilize the WCDMA network to carry high-speed services has become a major concern for network operators. This feature provides the service steering function for the benefit of network planning. Service steering helps improve the utilization of resources in each network and divide frequencies and RATs into different hierarchies. In addition to service steering, the selection of RAT for an MS to access also depends on the network load. This helps optimize the network performance in the following aspects: 

Tasks of different RATs can be clearly defined, which facilitates the planning of network capacity.

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Service steering can reduce interference between different traffic classes, increasing the network capacity of the WCDMA network.

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The flexible distribution of services to the WCDMA and GSM cells can improve the utilization of system resources, reduce the access congestion rate, and enhance the QoS of the network.

The service-steering function is initiated after RAB setup. The GBSC/MBSC decides whether to hand over the MS to the WCDMA network on the basis of the service handover indicator

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and the load difference between the GSM cell and the target WCDMA cell. The conditions on which the decision is based are as follows: 

The MS requests the CS service.

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The MS supports WCDMA services.

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The target WCDMA cell is lightly loaded and is with the lightest load among all neighboring WCDMA cells of the source GSM cell.

This feature in the present version (GBSS12.0) applies to only the steering of CS services from a GSM cell to a WCDMA cell.

Enhancement None

Dependency Dependency on MBSC hardware The Iur-g interface can be configured only on the FG2a/FG2c/GOUa/GOUc board. Dependency on MBTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS/RAN features This feature depends on the following feature: GBFD-114321 GSM/WCDMA Service Based Handover WRFD-070007 GSM and WCDMA Traffic Steering Based on Iur-g Dependency on other NEs None

7.6 GSM & LTE Interoperability 7.6.1 GBFD-511301 Cell Reselection Between GSM and LTE Availability This feature was introduced in GBSS12.0 for test. It is commercially used from GBSS13.0.

Summary This feature enables the GSM/LTE dual-mode MS in idle mode to perform cell reselection based on the level of the neighboring cells and setting of the radio access technology (RAT) priority.

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Benefits 

This feature enables the GSM network and LTE network to work as a complement to each other. This is profitable for operators who have deployed both the GSM network and LTE network.

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This feature enables the existing GSM network to provide communication services to LTE subscribers at the initial deployment stage of LTE, generating profit for the LTE operators.

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This feature can be used to balance the traffic between the GSM network and LTE network, prolonging the lifecycle of the GSM network.

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A GSM/LTE dual-mode MS can be made to camp on the LTE network through the setting of the RAT priority when the GSM/LTE dual-mode MS is within the coverage area of the LTE network.

Description An MS in idle mode periodically measures the level of the serving cell and the cell of the neighboring cells specified in the system information. The MS determines whether to perform cell reselection based on the settings of the mode priority parameters and on the cell reselection algorithm. In this way, the MS can always camp on a cell that can provide quality services. Therefore, the purpose of this feature is to bind the MS to a cell that can provide quality services. The cell reselection between GSM and LTE is based on the setting of the RAT priority. The RAT priority is set on the BSC side, and is sent to the MS through the system information message SI2quater. Different RAT priorities must be set for the GSM and LTE networks. Therefore, the MS can select to camp on the network of higher service quality based on the RAT priorities. The MS obtains the information about the frequencies of the neighboring cells by parsing the system information message SI2quater. It also measures the downlink level of all neighboring cells to obtain the candidate cells for reselection. Then, the MS sorts the candidate cells according to the RAT priority, and selects the best cell for reselection. This feature supports the cell reselection between GSM and LTE FDD and the cell reselection between GSM and LTE TDD.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It is recommended working with the following features: GBFD-511312 Fast LTE Reselection at 2G CS Call Release

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GBFD-511313 CSFB Dependency on other NEs The Core network must support both GSM and LTE. The MS must support both GSM and LTE.

7.6.2 GBFD-511302 PS Handover Between GSM and LTE Based on Coverage Availability This feature is available for beta use from GBSS12.0. It is available for commercial use from GBSS13.0.

Summary MSs in PS connection report MRs to the BSC periodically. The BSC obtains the receive level of the serving cell through MRs. When the receive level of the serving cell remains lower than the specified PS handover threshold for a period, the BSC triggers the PS handover between GSM and LTE. In this manner, the MS reselects a neighboring cell with a higher receive level.

Benefits PS handover shortens the duration of the PS service disruption to no more than 150 ms theoretically and provides guaranteed QoS for PS services, especially conversational services. Therefore, the operators can deploy more value-added services such as VoIP, PoC, and Gaming. This feature provides PS coverage for cells of another RAT to ensure the PS service continuity. In this manner, the network performance and user experience are improved.

Description Conversational services have a high requirement for the service delay, which cannot be met through cell reselection. In view of this, Huawei introduces the PS handover, during which radio resources are allocated to the target cell before the cell change. In this manner, the service disruption during cell change is reduced to less than 150 ms. Based on the MRs reported by the MS, the BSC triggers the coverage-based PS handover between GSM and LTE when the receive level of the serving cell remains lower than the PS handover threshold for a period. This ensures that the MS can reselect a neighboring cell with a higher receive level. As the receive level of the neighboring cell is considered before the handover, the success rate of the handover, the throughput of the new cell, and the PS QoS can be guaranteed.

Enhancement GBSS13.0 The Fast PS Handover between GSM and LTE function is introduced.

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If GSM cells and LTE cells are co-sited and cover the same areas, blind handovers must be supported. When a GSM/LTE dual-mode or multi-mode MS is processing PS services in a GSM cell, a service-based or load-based PS handover can be triggered to hand over the MS to an LTE cell. In this case, a target LTE cell can be selected according to the default system setting, without using the measurement reports (MRs).

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following features: GBFD-511301 Cell Reselection Between GSM and LTE GBFD-119502 PS Handover

PS handover priority: GBFD-511306 GSM/LTE Service Based PS Handover > GBFD-511303 PS Handover Between GSM and LTE Based on Quality > GBFD-511304 PS Handover Between GSM and LTE Based on Cell Load > GBFD-511302 PS Handover Between GSM and LTE Based on Coverage It is recommended the 4 features working together. Dependency on other NEs The MS must support both GSM and LTE. The SGSN must support PS handover between GSM and LTE.

7.6.3 GBFD-511303 PS Handover Between GSM and LTE Based on Quality Availability This feature is available for beta use from GBSS12.0. It is available for commercial use from GBSS13.0.

Summary MSs in PS connection report MRs to the BSC periodically. Based on the MRs, the BSC triggers a PS handover to a neighboring LTE cell if the UL or DL signal quality in the current GSM cell on the air interface reaches the specified threshold.

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Benefits PS handover shortens the duration of the PS service disruption to no more than 150 ms theoretically and provides guaranteed QoS for PS services, especially conversational services. Therefore, the operators can deploy more value-added services such as VoIP, PoC, and Gaming. In the scenarios with severe signal attenuation, this feature can be used to prevent PS service disruption due to deterioration of signal quality on the air interface, improving network performance and user experience.

Description Conversational services have a high requirement for the service delay, which cannot be met through cell reselection. In view of this, Huawei introduces the PS handover, during which radio resources are allocated to the target cell before the cell change. In this manner, the service disruption during cell change is reduced to less than 150 ms. When the UL or DL air interface quality of the MS in the serving cell is reaches the preset threshold, the BSC triggers the PS handover between GSM and LTE so that the MS reselects an LTE neighboring cell with the highest receive level. In this manner, the success rate of the PS handover, the throughput of the new cell, and the PS QoS are guaranteed.

Enhancement GBSS13.0 The Fast PS Handover between GSM and LTE function is introduced. If GSM cells and LTE cells are co-sited and cover the same areas, blind handovers must be supported. When a GSM/LTE dual-mode or multi-mode MS is processing PS services in a GSM cell, a service-based or load-based PS handover can be triggered to hand over the MS to an LTE cell. In this case, a target LTE cell can be selected according to the default system setting, without using the measurement reports (MRs).

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following feature: GBFD-511301 Cell Reselection Between GSM and LTE GBFD-119502 PS Handover PS handover priority: GBFD-511306 GSM/LTE Service Based PS Handover > GBFD-511303 PS Handover Between GSM and LTE Based on Quality > Issue V0.5 (2011-08-30)


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GBFD-511304 PS Handover Between GSM and LTE Based on Cell Load > GBFD-511302 PS Handover Between GSM and LTE Based on Coverage It is recommended the 4 features working together.

Dependency on other NEs The MS must support both GSM and LTE. The SGSN must support PS handover between GSM and LTE.

7.6.4 GBFD-511304 PS Handover Between GSM and LTE Based on Cell Load Availability This feature is available for beta use from GBSS12.0. It is available for commercial use from GBSS13.0.

Summary Based on the traffic load and the MRs reported by the MS in PS connection mode, the BSC may trigger the PS handover from GSM to LTE when the PS load on the GSM cell is high to achieve load balance and in addition, to fully utilize the transmission resources.

Benefits PS handover shortens the duration of the PS service disruption to no more than 150 ms and provides guaranteed QoS for PS services, especially the conversational service. Therefore, the operators can deploy more value-added services such as VoIP, PoC, and Gaming. When the GSM network is congested, this feature can be used to transfer part of the load of the GSM cell to the neighboring LTE cells, increasing the PS service rate and enhancing the network performance and user experience.

Description With the construction of the LTE network, the networking with both GSM and LTE is widely used. Huawei aims to fully utilize the resources of the two networks. The LTE network can take over part of PS services from the GSM network. In an area covered with both GSM and LTE networks, if the load difference between the two networks is great and the current services are supported by both GSM and LTE, the PS handover between GSM and LTE can be triggered for load balance. When this feature is enabled, the BSC selects an LTE neighboring cell with the highest receive level for the handover. In this manner, the success rate of the PS handover, the throughput of the new cell, and the PS QoS are guaranteed.

Enhancement GBSS13.0

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The Fast PS Handover between GSM and LTE function is introduced. Conversational services have a high requirement for service interruption duration, which cannot be met by using cell reselection. The PS handover technique, however, solves this problem. During a PS handover, radio resources are allocated to the target cell before the MS camps on the target cell. In this manner, the service interruption duration is reduced to less than 150 ms. If GSM cells and LTE cells are co-sited and cover the same areas, blind handovers must be supported. When a GSM/LTE dual-mode or multi-mode MS is processing PS services in a GSM cell, a service-based or load-based PS handover can be triggered to hand over the MS to an LTE cell. In this case, a target LTE cell can be selected according to the default system setting, without using the measurement reports (MRs).

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following feature: GBFD-511301 Cell Reselection Between GSM and LTE GBFD-119502 PS Handover PS handover priority: GBFD-511306 GSM/LTE Service Based PS Handover > GBFD-511303 PS Handover Between GSM and LTE Based on Quality > GBFD-511304 PS Handover Between GSM and LTE Based on Cell Load > GBFD-511302 PS Handover Between GSM and LTE Based on Coverage It is recommended the 4 features working together.

Dependency on other NEs The MS must support both GSM and LTE. The SGSN must support PS handover between GSM and LTE.

7.6.5 GBFD-511305 PS Handover Between GSM and LTE Based on Mode Priority Availability This feature is available for beta use from GBSS12.0. It is available for commercial use from GBSS13.0.

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Summary This feature enables operators to set priorities for GSM and LTE networks. In this manner, during the PS handover, the MS will select a network with the higher priority.

Benefits PS handover shortens the duration of the PS service disruption to no more than 150 ms and provides guaranteed QoS for PS services, especially the conversational service. Therefore, the operators can deploy more value-added services such as VoIP, PoC, and Gaming. The operator can use the LTE network to carry PS services preferentially. That is, in the area with LTE coverage, use the LTE network to provide high-speed data services for GSM/LTE dual-mode users; in the area without LTE coverage, use the GSM network to carry the services. In this manner, the operator can make profit quickly from the LET network and the user experience is enhanced.

Description In a network with both GSM and LTE coverage, this feature enables the GSM/LTE dual-mode MSs to select LTE network preferentially for PS services. Based on MRs from the MS, the BSC triggers a PS handover when the downlink level of the serving cell reaches the level threshold for PS handover, when the UL or DL air interface quality decreases to the handover threshold, or when the PS load of the GSM cell is high. The BSC selects the cell with the highest receive level from the cells in a network with the highest priority as the target cell. Because the receive level, service quality, load, and network mode of the target cell and the suitable network is considered before the PS handover, the handover success rate and the throughput of the target cell are guaranteed. This feature must be used together with the feature GBFD-511302 PS Handover Between GSM and LTE Based on Coverage, GBFD-511303 PS Handover Between GSM and LTE Based on Quality, or GBFD-511304 PS Handover Between GSM and LTE Based on Cell Load.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features Depend on: GBFD-511301 Cell Reselection Between GSM and LTE GBFD-511302 PS Handover Between GSM and LTE Based on Coverage or

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GBFD-511303 PS Handover Between GSM and LTE Based on Quality or GBFD-511304 PS Handover Between GSM and LTE Based on Cell Load GBFD-119502 PS Handover Dependency on other NEs The MS must support both GSM and LTE. The SGSN must support PS handover between GSM and LTE.

7.6.6 GBFD-511306 GSM/LTE Service Based PS Handover Availability This feature is available for beta use from GBSS12.0. It is available for commercial use from GBSS13.0.

Summary In a network with both GSM and LTE coverage, the BSC hands over services of different types to the GSM or LTE network based on the service distribution information sent by the SGSN.

Benefits 

PS handover shortens the duration of the PS service disruption to no more than 150 ms and provides guaranteed QoS for PS services, especially the conversational service. Therefore, the operators can deploy more value-added services such as VoIP, PoC, and Gaming.



The services of different types are handed over to the GSM or LTE network based on the service attribute. In this manner, the loads on the two networks are balanced. In addition, the PS services will not be handed over to an inappropriate network.



The operator can use the LET network to carry the services with high requirement for rate and delay, enhancing user experience and increasing the revenue.

Description In a network with both GSM and LTE coverage, the operator can divide the services into multiple types, and then determine the network (GSM or LTE) for carrying each type of services. In this manner, the load is balanced between the two networks, and the operator can use the advantages of both GSM and LTE to provide satisfactory service quality. For example, the operator can use the LTE network to carry the streaming services with a high requirement for rate and the conversational services with a high requirement for delay, and use the GSM network to carry the background services with a low requirement for rate and delay. The operator can configure the policy on the core network, and then during the PS handover, the BSC hands over the services with different types to the corresponding network according to the service distribution information sent by the core network. According to 3GPP 48.018, the PS HANDOVER REQUEST message or the CREATE BSS PFC message from the SGSN contains the IE that indicates the service type. If the IE is "Network initiated cell change order to E-UTRAN or PS handover to E-UTRAN procedure

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should be performed", the handover to an LTE cell is preferred. In this case, the BSC selects an LTE neighboring cell with the highest receive level as the target cell, and then informs the MS to hand over to the target cell through PS handover.

Enhancement GBSS13.0 The Fast PS Handover between GSM and LTE function is introduced. Conversational services have a high requirement for service interruption duration, which cannot be met by using cell reselection. The PS handover technique, however, solves this problem. During a PS handover, radio resources are allocated to the target cell before the MS camps on the target cell. In this manner, the service interruption duration is reduced to less than 150 ms. If GSM cells and LTE cells are co-sited and cover the same areas, blind handovers must be supported. When a GSM/LTE dual-mode or multi-mode MS is processing PS services in a GSM cell, a service-based or load-based PS handover can be triggered to hand over the MS to an LTE cell. In this case, a target LTE cell can be selected according to the default system setting, without using the measurement reports (MRs).

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following feature: GBFD-511301 Cell Reselection Between GSM and LTE GBFD-119502 PS Handover PS handover priority: GBFD-511306 GSM/LTE Service Based PS Handover > GBFD-511303 PS Handover Between GSM and LTE Based on Quality > GBFD-511304 PS Handover Between GSM and LTE Based on Cell Load > GBFD-511302 PS Handover Between GSM and LTE Based on Coverage It is recommended the 4 features working together. Dependency on other NEs The MS must support both GSM and LTE. The SGSN must support PS handover between GSM and LTE.

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7.6.7 GBFD-511307 eNC2 Between GSM and LTE Availability This feature was introduced in GBSS12.0 for test. It is commercially used from GBSS13.0.

Summary In a GSM/LTE hybrid network, when the MS is in a GSM cell, the MS periodically sends packet measurement reports to the BSC if the serving cell is in NC2 mode and packet connection state. On receiving the reports from the MS, the BSC triggers a network-controlled cell reselection based on the receive level, cell load, receive quality, modulation scheme, and service priority indicated by the message sent from the core network. If the target cell is an LTE cell, the BSC triggers a procedure of eNC2 between GSM and LTE.

Benefits Compared with the MS-controlled cell reselection, eNC2 Between GSM and LTE has the following benefits: The following factors are considered at the network so that the MS can be reselected to a cell with better signal quality: receive level of the serving cell, receive quality over the Um interface, and packet service load, priority of modulation scheme, and service priority indicated by the message sent from the core network. This can prevent deterioration of QoS of the MS. In this manner, the user experience can be improved, for the duration of packet service disruption is shortened to less than 500 ms.

Description Four types of cell reselection decision are involved in eNC2 between GSM and LTE: service-based cell reselection decision, quality-based cell reselection decision, load-based cell reselection decision, and coverage-based cell. 1) Service-based cell reselection decision According to 3GPP 48.018, the PS HANDOVER REQUEST message or the CREATE BSS PFC message from the SGSN contains the IE that indicates the service type. If the IE is "Network initiated cell change order to E-UTRAN or PS handover to E-UTRAN procedure should be performed", the reselection to an LTE cell is preferred. In this case, the BSC selects an LTE neighboring cell with the highest receive level as the target cell, and then informs the MS to reselect the target cell through an eNC2 procedure. 2) Quality-based cell reselection decision The BSC determines whether the radio link quality is good or bad according to the receive quality or bit error rate, and performs a cell reselection decision based on the receive quality of the link over the Um interface. When the receive quality of the uplink or downlink radio link deteriorates to a specified threshold, the BSC triggers the NC2 procedure. The BSC selects the cell with the highest receive level from the cells in a network with the highest priority as the target cell. 3) Load-based cell reselection decision The BSC performs a cell reselection decision based on the packet load of the serving cell. When the packet load of the serving cell reaches a specified threshold, the BSC triggers the

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NC2 procedure. The BSC selects the cell with the highest receive level from the cells in a network with the highest priority as the target cell. 4) Coverage-based cell reselection decision The BSC performs a cell reselection decision based on the receive level of the serving cell. When the receive level of the serving cell is lower than a specified threshold for a period, the BSC triggers the NC2 procedure. The BSC selects the cell with the highest receive level from the cells in a network with the highest priority as the target cell.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature depends on the following feature: GBFD-511301 Cell Reselection Between GSM and LTE GBFD-119107 Networking Control Mode Dependency on other NEs The MS must support both GSM and LTE and NC2 procedure.

7.6.8 GBFD-511308 eNACC Between GSM and LTE Availability This feature was introduced in GBSS12.0 for test. It is commercially used from GBSS13.0.

Summary This feature supports eNACC from LTE to GSM only. In packet transfer mode, the UE sends the eNodeB a message, requesting for the system information of the target GSM cell. Upon receiving the message, the eNodeB sends the system information of the target GSM cell to the UE. Upon receiving the system information, the UE accelerates the packet service access to the target GSM cell.

Benefits 

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The resources of the original cell can be released for new subscribers faster after the cell reselection. In this manner, the system capacity is increased.

Description eNACC is a function based on which the UE accesses the target GSM cell quickly after the cell reselection is completed without receiving the complete system information of the target cell. eNACC does not control cell reselection of the UE. Instead, the network is informed of the message that the UE requires cell reselection, and then the network sends the system information of target GSM cells to the UE before the cell reselection. In this manner, the cell reselection is accelerated, and therefore the duration of data transmission disruption is reduced greatly. As the cell reselection is accelerated, the SGSN can detect faster that a new cell is reselected for the UE. Therefore, the resources of the source LTE cell can be released faster for other subscribers. In this manner, the system capacity is increased. Limited by 3GPP 48.018 technical specifications, the system does not support GSM-to-LTE eNACC. LTE-to-GSM eNACC is supported only when the BSC supports RIM over the Gb interface.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It depends on the following features: GBFD-116301 Network Assisted Cell Change (NACC) Dependency on other NEs The MS must support both GSM and LTE and NACC procedure. The SGSN must support eNACC procedure.

7.6.9 GBFD-511309 SRVCC Availability This feature was introduced in GBSS12.0. This feature is recommended for test purposes rather than for commercial use.

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Summary With Single Radio Voice Call Continuity (SRVCC), speech services in the LTE network can be maintained when it is handed over to a GERAN network or UTRAN network.

Benefits The speech service can be maintained when it is handed over from the GERAN to the UTRAN.

Description At the initial stage of the LTE project, the 3GPP defines that only the packet service is supported. In the evolution from GERAN to LTE, the 3GPP R8 defines two solutions: SRVCC and CSFB, to realize the interoperability of speech services between GERAN and LTE. To implement the SRVCC solution, the IP Multimedia Subsystem (IMS) must be deployed at the CN and the speech service must be provided. With the assistance of the VoIP speech service routing, control, and triggering by the IMS and the handover control by the Mobile Management Entity (MME), the speech service in the LTE network can be handed over to the GERAN/UTRAN smoothly. In SRVCC, speech services are implemented in the LTE packet network, so technically the SRVCC solution can be regarded as a real LTE VoIP technique. Through circuit switch in GERAN network or packet switch in LTE network, the UE can access IMS based on which the speech service is maintained. SRVCC supports handover of speech services from LTE to GSM only. SRVCC is available only when GERAN network and LTE network cover the same area. GBSS12.0 does not support SRVCC in DTM mode.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The CN is deployed with IMS and the speech service is available. The MS must support both GSM and LTE. The MSC and MGW must support this feature.

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7.6.10 GBFD-511310 Multi Technology Neighbour Cell Based Handover Availability This feature was introduced in GBSS13.0.

Summary This feature supports the handover between GSM frequency bands and LTE frequency bands.

Benefits Through this feature, an MS is handed over to a specific GSM or LTE frequency band, and the resources of the LTE or GSM frequency band occupied by the MS before the handover are released. This feature improves the Quality of Service (QoS) of end users, thereby increasing the revenue of operators.

Description This feature is an enhancement of the inter-RAT handover. It supports handovers between frequency bands of different RATs based on the priorities of neighboring cells. Through this feature, an MS is handed over to a frequency band of another RAT to meet the requirements of users for mobility or to ensure that the capacity restrictions on frequency bands are not exceeded. This feature can be applied to the following combinations of RATs and frequency bands: 

GSM 900M

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GSM 1800M

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LTE 800M

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LTE 900M

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LTE 2.6G

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It depends on the following features: GBFD-511303 PS Handover Between GSM and LTE Based on Quality

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GBFD-511304 PS Handover Between GSM and LTE Based on Cell Load GBFD-511302 PS Handover Between GSM and LTE Based on Coverage Dependency on other NEs The MS must support both GSM and LTE.

7.6.11 GBFD-511312 Fast LTE Reselection at 2G CS Call Release Availability This feature was introduced in GBSS13.0.

Summary After an MS terminates a call in the GSM network, the MS can camp on the LTE network according to the cell reselection indicator after release information element in the Channel Release message, without performing a cell reselection procedure.

Benefits This feature speeds up cell reselection so that an MS can immediately receive services in the LTE network after terminating its call in the GSM network.

Description Generally, after an MS terminates a call in a GSM cell, it camps on the GSM cell. If a neighboring LTE cell meets the requirements for cell reselection, the MS can camp on the LTE cell through a cell reselection. The MS, however, must receive system information and perform cell reselection calculations before initiating the cell reselection. This means that the MS cannot process services in the LTE network immediately. When this feature is enabled, the BSS selects the best neighboring LTE cell based on the measurement information on neighboring LTE cells after the MS terminates its call in the GSM network. Then, the BSS sends the frequency information about the best neighboring LTE cell to the MS by using a Channel Release message, instructing the MS to camp on the LTE cell. By doing so, the MS can reselect an LTE cell without performing cell reselection calculations, thereby speeding up cell reselection.

Enhancement None

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It is recommended working with the following features: GBFD-511309 SRVCC GBFD-511313 CSFB Dependency on other NEs The MS must support this feature.

7.6.12 GBFD-511313 CSFB Availability This feature was introduced in GBSS13.0.

Summary The Circuit Switch FallBack (CSFB) feature enables a UE camping on the E-UTRAN network to access the GERAN/UTRAN network through a PS handover or PS cell reselection and then process CS services. This feature is available only when the E-UTRAN and GERAN/UTRAN networks cover the same areas.

Benefits This feature enables a UE to be handed over from the LTE network to the GERAN network to process CS services, thereby protecting the investment in the GERAN network. The GERAN network can be used to provide CS services, and the E-UTRAN network can be used to provide high-speed PS services. Compared with the Single Radio Voice Call Continuity (SRVCC) technique, CSFB provides CS services for UEs in the LTE network with a simpler network structure, without deploying the IP Multimedia Subsystem (IMS).

Description In the LTE startup stage, the 3GPP stipulates that LTE supports only PS services. In the evolution from GERAN to E-UTRAN, 3GPP Release 8 defines two solutions, SRVCC and CSFB, to implement the interoperability between GERAN and E-UTRAN. If a mature GERAN network is available in the initial stage of E-UTRAN deployment, the operator can use the existing GERAN network to provide CS services whereas use the LTE network to provide PS services. This saves the investment in the existing GERAN network. With CSFB, a UE in the LTE network can be handed over to the GERAN network to process CS services. To implement CSFB, the SGs interface must be configured between the MSC server and the Mobile Management Entity (MME) so that dual-mode UEs attached to the LTE network can process services such as calling, calling response, SMS, and combined location update between E-UTRAN and GERAN. Technically, CSFB is not a real LTE VoIP technique because a dual-mode UE has been handed over from E-UTRAN to GERAN before it initiates CS services. The CSFB feature is available only when GERAN and E-UTRAN cover the same areas. CSFB does not need the IMS, thereby simplifying the network architecture. However, every time the UE makes or receives a call, the UE is handed over from E-UTRAN to GERAN.

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This increases the access delay. In addition, the ongoing LTE PS services are affected by the incoming call.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It is recommended working with the following features: GBFD-511301 Cell Reselection Between GSM and LTE GBFD-511312 Fast LTE Reselection at 2G CS Call Release Dependency on other NEs The SGs interface must be configured between the MSC server and the MME. The MS must be a GSM/LTE dual-mode MS and support CSFB.

7.7 GSM & TD-SCDMA Interoperability 7.7.1 GBFD-114302 GSM/TD-SCDMA Interoperability Availability This feature was introduced in GBSS7.0.

Introduction This feature enables dual-mode MSs to be handed over and reselect cells between a GSM network and a TD-SCDMA network when the MS processes CS or PS services.

Benefits 

Dual-mode MSs can roam and be handed over from a TD-SCDMA network to a GSM network. This lets dual-mode MSs enjoy continuous network coverage in scenarios with limited TD-SCDMA coverage, for example, in the early stages of network deployment.



A GSM network can smoothly evolve into a TD-SCDMA network. This helps telecom operators increase return on investment (ROI).

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Description When GSM/TD-SCDMA interoperability is enabled, dual-mode MSs can roam and be handed over between a GSM network and a TD-SCDMA network. Huawei GSM BSS supports MS handovers and roaming in the following scenarios: 

In idle mode, an MS roams from a GSM network to a TD-SCDMA network.



In idle mode, an MS roams from a TD-SCDMA network to a GSM network.

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In dedicated mode, an MS is handed over from a GSM network to a TD-SCDMA network.



In dedicated mode, an MS is handed over from a TD-SCDMA network to a GSM network.

Currently, Huawei GSM BSS does not support PS domain handovers. Interoperability between TD-SCDMA networks and GPRS/EDGE networks is implemented by using the autonomous cell reselection of MSs. The inter-RAT network assisted cell change (NACC) function can speed up the cell reselection from a TD-SCDMA network to a GPRS/EDGE network. The network-controlled cell reselection from a GPRS/EDGE network to a TD-SCDMA network is implemented by using the inter-RAT Network Control Cell Reselection Mode 2 (NC2) function.

Enhancement This feature solves the problem of some GSM terminals breaking down or restarting when a neighboring TD-SCDMA cell is broadcast in a system information message. In addition, this feature enables dual-mode MSs to be handed over between a GSM network and a TD-SCDMA network.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The MS, MSC, SGSN, HLR, and the NEs in the TD-SCDMA network must support this feature.

7.7.2 GBFD-511401 Iur-g Interface Between GSM and TD-SCDMA Availability This feature was introduced in GBSS12.0.

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Summary The Iur-g interface is used for information exchange between the BSC and the TD-RNC. Through the information exchange and common measurement procedures, the BSC and TD-RNC can obtain the capacity and load information of each other.

Benefits The GSM/TD-SCDMA inter-RAT handover mechanism is developed into a mechanism similar to BSC internal handover in GSM900/1800. In this way, the handover procedure is simplified. This decreases the handover delay and increases the handover success rate, improving the customer experience.

Description The Iur-g interface is introduced because the existing GSM/TD-SCDMA inter-RAT handover does not meet the requirements of telecom operators in terms of the handover delay and the handover success rate. The Iur-g interface is used for the information exchange between the BSC and the TD-RNC, increasing the GSM/TD-SCDMA inter-RAT handover success rate and decreasing the handover delay. The Iur-g interface supports the information exchange and common measurement procedures. The information exchange procedure is used for exchanging capacity information between the BSC and the TD-RNC. The common measurement procedure is used for exchanging load information between the BSC and the TD-RNC. 1.

Information exchange procedure

Currently, the information exchange procedure can only be initiated by the TD-RNC and terminated by the BSC. In this procedure, the TD-RNC sends the BSC an information exchange initialization request message, specifying the measurement objects (CGI of the GSM cell), information exchange type (Cell Capability Class/NACC Related Data), and reporting mode (On Demand/On Modification). The reporting mode is described as follows: 1) On demand: Upon receiving the information exchange initialization request message from the TD-RNC, the BSC returns the cell capacity information through a response message. 2) On Modification: Upon receiving the initialization request message from the TD-RNC, the BSC returns the cell capacity information through a response message. If the information is changed later, the BSC notifies the TD-RNC of the change through an Information Report message. 2.

Common measurement

Currently, the common measurement procedure can only be initiated by the TD-RNC and terminated by the BSC. In this procedure, the TD-RNC sends the BSC a common measurement initialization request message, specifying the measurement objects (CGI of the GSM cell), measurement type (Load/RT Load/NRT Load), and reporting mode (On Demand/event-triggered/periodic). The reporting mode is described as follows: 1) On demand: Upon receiving the common measurement initialization request message from the TD-RNC, the BSC returns the cell load information through a response message.

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2) Periodic: Upon receiving the common measurement initialization request message from the TD-RNC, the BSC returns the common measurement initialization response message. Subsequently, the BSC periodically reports the common measurement results according to the specified period. 3) Event-triggered: Upon receiving the common measurement initialization request message from the TD-RNC, the BSC returns the common measurement initialization response message. Subsequently, the BSC reports the common measurement results when the event triggers the conditions.

Enhancement None

Dependency Dependency on BSC hardware The BSC must be configured with a pair of IP interface boards for the Iur-g interface. Dependency on BTS hardware None Dependency on other GBSS features None Dependency on other NEs None

7.7.3 GBFD-511402 Radio Resource Reserved Handover Between GSM/TD-SCDMA Based on Iur-g Availability This feature was introduced in GBSS12.0.

Summary Through the information exchange on the Iur-g interface between the BSC and the TD-RNC, radio resource reservation is added to the standard GSM/TD-SCDMA handover procedure. In this way, the resource reservation procedure is completed without the assistance of the CN. The original redirecting procedure is maintained for compatibility with the CN.

Benefits This feature works with GSM/TD-SCDMA inter-RAT handover to reduce the handover delay by 80 ms and increase the handover success rate by 0.8% in a co-CN scenario, according to the theoretical analysis results.

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procedure is simplified. This decreases the handover delay and increases the handover success rate, improving the customer experience. This feature complies with the specifications of China Mobile. Through the information exchange on the Iur-g interface between the BSC and the TD-RNC, radio resource reservation is added to the standard GSM/TD-SCDMA handover procedure. In this way, the resource reservation procedure is completed without the assistance of the CN. The TD-RNC selects an optimum target cell to perform handover based on the signal level, capacity, and load of neighboring GSM cells. In advance of the handover, the TD-RNC reserves radio resources through the Iur-g interface to reduce the handover delay. This feature is advantageous especially in scenarios of heavy load, fast fading, and high-speed movement in GSM. The radio resource handover procedure is described as follows: After receiving measurement reports (MRs) from the UE, the TD-RNC selects an optimum target cell to perform handover based on the capacity and load of neighboring GSM cells. The TD-RNC requests Iur-g SCCP links for this UE and sends the BSC an Enhanced Relocation Resource Request message, requesting radio resources for this UE. Upon receipt of the Enhanced Relocation Resource Request message, the BSC assigns a D-RNTI to the UE, reserves radio resources according to the requested Speech Version, and responds to the TD-RNC with an Enhanced Relocation Resource Response message. Optionally, this message can carry the capacity and load information of the GSM cell. After receiving the Enhanced Relocation Resource Response message, the TD-RNC sends the UE the associated radio resources through the Handover From Utran Command message. At the same time, it sends the CN a Relocation Required message. Upon receipt of the message, the CN sends the BSC a Handover Request message. After the BSC completes the setup of A interface resources, the UE is handed over to the target cell according to the traditional inter-RAT handover procedure.

Enhancement None

Dependency Dependency on BSC hardware The BSC must be configured with a pair of IP interface boards for the Iur-g interface. Dependency on BTS hardware None Dependency on other GBSS features GBFD-511401 Iur-g Interface Between GSM and TD-SCDMA Dependency on other NEs None

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7.7.4 GBFD-511403 Extended BCCH Availability This feature was introduced in GBSS13.0.

Summary When this feature is enabled, SI2Quater and SI13 messages are broadcast on the extended BCCH. This speeds up system information message broadcasting and shortens the delay in inter-RAT cell reselection.

Benefits This feature shortens the delay in inter-RAT cell reselection between a GSM network and a TD-SCDMA network.

Description If SIQuater and SI13 messages are broadcast on a BCCH, they are multiplexed on the same BCCH as other system information messages. In addition, only one SIQuater or SI13 message is broadcast in several scheduling periods. This prolongs inter-RAT cell reselection. If SI2Quater and SI13 messages are specified to be broadcast on an extended BCCH, only these two types of messages are broadcast on the extended BCCH. In addition, one SIQuater or SI13 message is broadcast in each scheduling period. This speeds up the scheduling and broadcasting of SI2Quater and SI13 messages. As a result, MSs quickly obtain system information messages for inter-RAT cell reselection, and the delay in cell reselection decreases.

Enhancement None


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7.7.5 GBFD-511405 NC2 between GSM and TD-SCDMA Availability This feature is introduced in GBSS14.0 only for tests.

Summary On a GSM and TD-SCDMA hybrid network, MSs in packet transfer mode using NC2 periodically send measurement reports (MRs) to the BSC. Upon receiving the MRs, the BSC initiates a cell reselection from GSM to TD-SCDMA for the MSs in NC2 mode based on the receive level, cell load, and receive quality of the serving cell, as well as the receive level, cell load, and service duration of neighboring TD-SCDMA cells.

Benefits By comprehensively considering the receive level, cell load, and receive quality of the serving cell, as well as the receive level, cell load, and service duration of neighboring TD-SCDMA cells, the BSC instructs GSM/TD-SCDMA dual-mode MSs to reselect to TD-SCDMA cells so that PS services are preferentially allocated to the TD-SCDMA network. This prevents such MSs from reselecting to GSM cells with a high signal strength, therefore improving user experience and increasing network capacity.

Description The BSC provides two sets of parameters for GSM/TD-SCDMA dual-mode MSs in idle or packet transfer mode. The differentiated parameter setting allows dual-mode MSs in packet transfer mode to measure the load and signal level of TD-SCDMA neighboring cells and to report the measured values in MRs sent to the BSC. According to the MRs sent by MSs, the BSC initiates a cell reselection from GSM to TD-SCDMA for MSs in NC2 mode and selects neighboring TD-SCDMA cells, whose load is lower than a specified threshold and whose receive level meets the minimum requirement, as candidate cells. The BSC also monitors the PS service duration of MSs. If the service duration of an MS in packet transfer mode exceeds a specified value, the BSC instructs the MS to reselect to a TD-SCDMA cell. The BSC obtains the loads of neighboring TD-SCDMA cells through the Iur-g interface between the GSM BSC and the TD-SCDMA RNC during the common measurement procedure of a cell.

Enhancement None


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Dependency on other GBSS features This feature depends on the following feature: GBFD-511401 Iur-g Interface Between GSM and TD-SCDMA This feature is mutually exclusive with the following feature: Optimization of GSM/TD-SCDMA inter-RAT cell reselection for MSs in packet transfer mode in GBFD-114302 GSM/TD-SCDMA Interoperability Dependency on other NEs This feature requires GSM/TD-SCDMA dual-mode MSs that support the NC2 procedure. The TD-SCDMA RNC must support the Iur-g interface to obtain the loads of neighboring TD-SCDMA cells.

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8

Network Security

8.1 Security 8.1.1 GBFD-113501 A5/1 and A5/2 Ciphering Algorithm Availability This feature was introduced in GBSS6.1.

Summary This feature is used when the voice, data, and signaling of the user are transmitted over the Um interface.


An evident advantage of the GSM system over the analog system is that the unauthorized users are prohibited to access the network and the data of the authorized users is encrypted through sophisticated ciphering algorithm, ensuring the communication security.



The ciphering algorithm is referred to as A5 algorithm, which is a 114-bit ciphering sequence according to the GSM specifications. The GSM specifications define eight ciphering algorithms: A5/0–A5/7. With this feature, all the voice and signaling information over the Um interface are transmitted in A5/1 or A5/2 ciphering mode. This ensures the network security.

Description The GSM specifications define eight ciphering algorithms: A5/0–A5/7. A5/0 indicates "Not encrypted". With this feature, all the voice and signaling information over the Um interface are transmitted in A5/1 or A5/2 ciphering mode. This ensures the network security. 

Ciphering procedure The MSC uses the Cipher Mode CMD message (including the required ciphering algorithms and the key Kc) to initiate the ciphering procedure through the BSC. Then, according to the ciphering algorithm supported by the MS, the ciphering algorithm required by the MSC, and the ciphering algorithm allowed by the BSC, the BSC decides Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd

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the algorithm to be used and notifies the BTS of the decision. The BSC then sends the Ciphering Mode CMD message to notify the MS of the ciphering algorithm. After receiving the Ciphering Mode CMD message, the MS initiates the transmission in ciphering mode.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The MS and the CN must support this feature.

8.1.2 GBFD-113503 A5/3 Ciphering Algorithm Availability This feature was introduced in GBSS7.0.

Summary This feature is used when the voice, data, and signaling of the user are transmitted over the Um interface.


An evident advantage of the GSM system over the analog system is that the unauthorized users are prohibited to access the network and the data of the authorized users is encrypted through sophisticated ciphering algorithm, ensuring the communication security.



The ciphering algorithm is referred to as A5 algorithm, which is a 114-bit ciphering sequence according to the GSM specifications. The GSM specifications define eight ciphering algorithms: A5/0–A5/7. With this feature, all the voice and signaling information over the Um interface are transmitted in A5/3 ciphering mode. This ensures the network security.

Description For details, see the description of the A5/1 and A5/2 ciphering algorithm.

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Enhancement None

Dependency Dependency on BSC hardware None Impact on the BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The MS and the CN must support this feature.

8.1.3 GBFD-113521 A5/1 Encryption Flow Optimization Availability This feature was introduced in GBSS8.1.

Summary With this feature, the BTS optimizes the A5/1 ciphering algorithm to improve the network security.

Benefits Information security becomes increasingly important as the subscribers use MSs to browse webpages and do business on the network. This feature aims to solve the low security problem of the A5/1 ciphering algorithm and therefore improve the data transmission security by optimizing the service processing procedure and increasing the complexity of network wiretapping.

Description With the technology development, some hacker organizations state that they can attack the calls encrypted by the A5/1 ciphering algorithm within 30 seconds in ideal conditions. Huawei studies the manner in which hackers attack, and prepares a scheme to enhance the A5/1 ciphering algorithm. With this scheme, only the network software needs to be upgraded. Therefore, hackers can attack the calls with a success rate of a maximum of only 10% within 40 successive days. In this manner, the data transmission security is greatly improved. The ciphering procedure is optimized from the following aspects: 

Fast SDCCH handover is adopted in the MS access procedure. This increases the difficulty for an intruder to trace the calls of an MS.

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The TCH timing handover is introduced to increase the difficulty for an intruder to trace an MS.

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The Hopping Sequence Number (HSN) in the Flex Training Sequence Code (TSC) and Flex Mobile Allocation Index Offset (MAIO) differentiates one TCH from another. Therefore, the characteristics of TCHs are different and an intruder cannot trace other TCHs according to the characteristics of a TCH.

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After the BTS sends a ciphering command, it stops sending System Information 5, 5bis, and 5ter over the SACCH on the SDCCH.

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The dummy bits are randomized.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature and the following feature are mutually exclusive: GBFD-115830 VAMOS Dependency on other NEs None

8.1.4 GBFD-113522 Encrypted Network Management Availability This feature was introduced in GBSS8.1.

Summary The encrypted network management is related to the secure socket layer (SSL). This feature allows the establishment of a TCP transmission channel between the network management server and a network element (NE) based on the encrypted SSL.


With the rapid development of the radio network, operators have higher requirements for the OM transmission security. Therefore, the encryption of the OM transmission channel becomes a basic requirement.

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The encryption of the OM transmission channel involves the encryption of the data transmitted between the LMT and the NE and of the data transmitted between the BSC and the BTS.

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This feature ensures the confidentiality of the data transmitted through the OM transmission channel, therefore effectively protecting the privacy of the subscriber data and reducing the risk that the transmitted plain text is intercepted.

Description In many scenarios of the communication between the network management system and the NE, a large amount of data is transmitted in the form of data files, including performance data file, log file, configuration data file, version file, and patch file. The traditional plain text transmission in the network is a threat to the secrecy of the transmitted data files. With the encrypted network management feature, a transmission channel based on the encrypted SSL is established between the network management server and the NE during the establishment of the TCP connection. The data is then transmitted over this encrypted channel. Application layer Transmission before encryption

Transport layer (TCP)

Application layer Transmission after encryption

Secure socket layer (SSL) Transport layer (TCP)

The encrypted network management feature supports the transmission of plain text and cipher text, and therefore does not affect the normal communication between the network management server and the NE that does not support the encrypted SSL. Network management server (supporting encrypted SSL)

Cipher text

Plain text

New network element

Old network element

(supporting encrypted SSL)

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This feature complies with RFC4217, and supports two SSL protocol versions, namely, SSL3.0 and TSL1.0.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The following M2000 feature must be activated: WOFD-210100 Encrypted Transmission

8.1.5 GBFD-113524 BTS Integrated IPsec Availability This feature is introduced in GBSS14.0.

Summary The BTS Integrated IPsec feature encrypts data transmitted between a BTS and a BSC that are connected over an external gateway. This ensures data confidentiality, integrity, and non-repeated sending and provides operators a secure end-to-end network.

Benefits This feature protects IP packets transmitted through an IP network from being intercepted or modified, providing an end-to-end protection for user data.

Description Internet Protocol Security (IPsec) is a protocol suite for securing IP communications. IPsec uses the Authentication Header (AH) and Encapsulating Security Payload (ESP) protocols to provide the following functions: 

Data confidentiality: Data is transmitted in ciphertext.

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Data integrity: Received data is checked to ensure that it is not modified.

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Data source verification: The credibility of the data source is checked.

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Repeated data rejection: Old or repeated packets are rejected to avoid attacks from malicious users who repeatedly send intercepted data.

To simplify the use and management of IPsec, Internet Key Exchange (IKE) is defined and provides the following functions to enhance bearer network security: 

Performs automatic key negotiation.



Sets up and maintains security associations.

IKE supports peer-end identification by using pre-shared keys and digital certificates. This feature is configured and maintained on the BSC. To enable this feature, the BSC must be connected to a BTS over an external gateway.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature should be used together with the following feature: GBFD-113526 BTS Supporting PKI This feature and the following feature are mutually exclusive: GBFD-117702 BTS Local Switch Dependency on other NEs None

8.1.6 GBFD-113526 BTS Supporting PKI Availability This feature is introduced in GBSS14.0.

Summary This feature enables an NE to automatically obtain a digital certificate authorized by the Certificate Authority (CA) of an operator. The NE with a digital certificate can be authenticated by the Internet Protocol Security (IPsec), IEEE 802.1X-2004 standard, or Secure Socket Layer (SSL) protocol.

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Benefits By authenticating NE identification, the Public Key Infrastructure (PKI) feature prevents malicious users from accessing the network and therefore improves the network security. This feature is used in conjunction with encryption technologies provided in IPsec or Secure Socket Layer (SSL) to protect user data from being intercepted or modified.

Description Based on Certificate Management Protocol version 2 (CMPv2), this feature provides a suite of functions that apply to certificate management between NEs. The suite includes functions such as certificate register request, key update, key restore, certificate revocation, cross-certification, CA key update notification, certificate authorization notification, and certificate revocation notification. This feature manages the local digital certificate for a BTS based on CMPv2. Figure 8-1 shows how CMPv2 is applied in PKI. Figure 8-1 Application of CMPv2 in PKI

During the digital certificate management process, this feature provides the following functions: 1.

BTS entity initialization: BTS entity initialization involves importing the public key of the root certificate and obtaining options supported by the PKI management entity.

2.

Certificate request: A certificate is authorized in the following scenarios:

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Initial registration and certification

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The CA or registration authority (RA) identifies a BTS before authorizing a certificate to the BTS. If the initial registration and certification is successful, the CA uses the public key of the BTS to authorize a certificate for it. Then, the CA sends the certificate to the BTS or releases the certificate to the public database. 

Key pair update Each key pair is updated periodically. Each update requires a new certificate.

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Certificate update A certificated must be updated before it expires.

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CA key pair update Each CA key pair is updated periodically.

3.

Certificate revocation: The BTS revokes a certificate by sending a certificate revocation request to the CA.

Enhancement None


8.2 Reliability 8.2.1 GBFD-117801 Ring Topology Availability This feature was introduced in GBSS7.0.

Summary The ring topology is a special chain topology. Several BTSs form a chain, and the lowest-level BTS is connected to the BSC through the transmission link, forming a ring. If there is a breakpoint on the ring, the BTSs that precede the breakpoint remain unchanged in networking mode whereas the BTSs that follow the breakpoint form a new chain connection in the reverse direction.

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Benefits Compared with the ordinary chain topology, the advantage of the ring topology is that when a connection is broken, the ring automatically breaks into two chains. In this way, the BTSs that precede and follow the breakpoint can work normally, improving the robustness of the system.

Description The ring topology supports the following operations: 

Automatic switchover

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Manual switchover

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Querying and dynamically configuring of the switchover parameters



Dynamic data configuration such as adding or deleting a BTS, cell, or TRX.

Figure 8-2 and Figure 8-3 show the ring topologies of the BTS: Figure 8-2 Ring topology (1)

Figure 8-3 Ring topology (2)

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Numbers 0 and 1 shown in Figure 8-2 refer to port 0 and port 1 of the BTS. In the BTS ring topology, the link established at port 0 is a forward link and the link established at port 1 is a reverse link. The BTS ring topology can be implemented between interface boards but not between subracks. In other words, the BTS ring topology must be implemented between the GEIUBs located in the same subrack, as shown in Figure 8-3. Generally, the BTS ring topology is a chain of BTS0, BTS1, and BTS2 in sequence, known as a forward direction. In the forward direction as shown in Figure 8-2, BTS0 is the highest-level BTS, BTS1 is the second-level BTS, and other BTSs are connected analogically. When the link A, B, C, or D is broken, the BTSs that precede the breakpoint remains in the same topology, and the BTSs that follow the breakpoint form a chain in a reverse direction. The BTS ring topology is categorized into two types: Huawei BTS ring topology I and Huawei BTS ring topology II. In BTS ring topology I, the BTS with a reverse link is initialized again after transmission disruption, and therefore the services of the BTS are interrupted. In BTS ring topology II, the services of the BTS with a reverse link are not interrupted after transmission disruption.

Enhancement Fast Ring Network Switch function is introduced in GBSS8.0. With this feature, when a transmission link in the ring network is faulty, all the BTSs behind the breaking point in the ring network perform the switchover in the reverse direction. The Fast Ring Network Switch feature accelerates the ring network switchover and the BTS does not need to be initialized in the reverse ring direction. Therefore, the call drops due to the ring network switchover and the impact of the switchover on the new calls are reduced. This improves the network reliability and user experience.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It is mutually exclusive with the following features: GBFD-118601 Abis over IP GBFD-118611 Abis IP over E1/T1 GBFD-113728 OML Backup GBFD-116601 Abis Bypass "Huawei BTS ring topology II" is mutually exclusive with GBFD-117301 Flex Abis Dependency on other NEs This feature cannot be used together with DXX.

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8.2.2 GBFD-113801 TRX Cooperation Availability This feature was introduced in GBSS6.1.

Summary With this feature, when the BCCH TRX or the TRX involved in baseband FH is faulty, the cell automatically rectifies the faults. Therefore, the services in the cell are not affected before the faulty TRX is replaced.

Benefits The TRX Cooperation feature ensures that the cell provides services continuously. This feature reduces the probability that the cell is out of service because of the faulty BCCH TRX. It also reduces the probability that the call quality in the cell is degraded because of the faulty TRX involved in the baseband FH. Therefore, the reliability of the network is greatly improved.

Description With this feature, when the BCCH TRX or the TRX involved in baseband FH is faulty, the cell automatically rectifies the faults. Therefore, the services in the cell are not affected before the faulty TRX is replaced. Based on the type of faulty TRXs and the handling method, the TRX cooperation is classified into BCCH TRX cooperation and baseband FH TRX cooperation. For the non-baseband FH cell, only the BCCH TRX cooperation occurs. For the baseband FH cell, both BCCH TRX cooperation and baseband FH TRX cooperation are likely to occur. 

BCCH TRX cooperation In the idle state, the MS needs to obtain information through the broadcast messages sent on the BCCH. The messages carry information about cell selection, adjacent cell, access control, dedicated channel control, cell identification code, location, and system parameters related to the PS services. When a BCCH TRX of a cell is faulty, all the services in this cell are interrupted. Therefore, when the BCCH TRX is faulty, another available TRX of the cell is used to substitute the faulty BCCH TRX to ensure that the cell can continue to provide services. After the fault in the original BCCH TRX is rectified, the BSC can switch the BCCH back to the original TRX. This process is called BCCH TRX cooperation.



Baseband FH TRX cooperation In the baseband FH cell, if the TRX involved in baseband FH is faulty, some speech frames in the call using the FH channel are lost. Therefore, the speech quality is degraded. To ensure the speech quality in the cell, the BSC enables the baseband FH TRX cooperation and remove the faulty TRX from the FH and continue the FH mode with the fine running TRX. In this way, the speech quality of the cell is not affected by the faulty TRX. This process is called baseband FH TRX cooperation. When the BCCH TRX in a baseband FH cell is faulty, baseband FH TRX cooperation can also be performed. That is, the cell is changed to the non-FH mode. After all the faults in the original BCCH TRX and in the TRX involved in FH are rectified, the baseband FH TRX cooperation can be performed. That is, the BSC changes the non-FH mode to the FH mode.

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Enhancement None


8.2.3 GBFD-117401 MSC Pool Availability This feature was introduced in GBSS7.0.

Summary With this feature, multiple MSCs form a resource pool to provide services for the subscribers belonging to one group of BSCs.

Benefits The MSCs in an MSC pool share the traffic load and resources. Therefore, this feature provides the following benefits: 

This feature increases the network capacity and saves the equipment investment.



This feature realizes the redundancy backup and therefore improves the network reliability because the addition or deletion of an MSC does not affect the services.

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This feature automatically adjusts the traffic load on an MSC and reduces the operation and maintenance cost of operators.

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The MSC pool is logically an MSC. Therefore, the number of handovers between MSCs is reduced and the network performance is improved.

Description With this feature, a maximum of 32 MSCs form a resource pool to provide services for the subscribers under one group of BSCs. Through the MSC pool, one BSC can be connected to multiple MSCs simultaneously. In addition, the traffic on the BSC is evenly distributed to the MSCs in the pool according to the NRI or load balancing principle. The following figure shows the typical networking of the MSC Pool feature:

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GBSS14.0 Optional Feature Description MSC 3 MSC 2 MSC 1

MSC 6 MSC 5 MSC 4

MSC 7

CS poolarea 2

CS poolarea 1 RAN node

RAN node

Area 1

Area 2

RAN node

RAN node

Area 5

PS poolarea 1

Area 6

RAN node Area 3

RAN node Area 7

RAN node Area 4

RAN node Area 8

PS poolarea 2

In the preceding figure, MSC 1, MSC 2, and MSC 3 form an MSC pool. All the CS services or PS services in the BSC service areas (Area 1, Area 2, Area 5, and Area 6) are routed to the MSC pool for further processing. The routing policies are described as follows: 

Routing by network load For the newly-registered MS, the BSC selects an MSC by using the load balancing algorithm based on the IMSI carried in the CMP L3 message, the status of MSCs in the MSC pool, and the available capacity. Then, the BSC directs the traffic of the MS to the selected MSC for processing. If the MS without the SIM card initiates an emergency call, the BSC selects the MSC based on the IMEI, the status of MSCs in the MSC pool, and the available capacity and then directs the traffic of the MS to the selected MSC for processing.



Routing by the NRI After the MS is registered, the MSC allocates the TMSI containing the NRI to the MS. The NRI is used for identifying an MSC in the MSC pool. During the call processing, the MS sends the TMSI to the network side. On receiving the TMSI, the BSC resolves the NRI from the TMSI and then directs the traffic to the MSC based on the MSC signaling point corresponding to the NRI in the configuration data. With this feature, the BSCs in the pool area share a group of MSCs. If heavy traffic hours of each BSC are different, less CN resources are required compared with the network where the MSC Pool feature is disabled. This saves the investment in the CN equipment. When an MSC in the MSC pool is faulty, the traffic of the newly accessed MS is automatically directed to another normal MSC, enhancing the network reliability. When some maintenance operations such as software upgrade are performed on an MSC in the MSC pool, the traffic on this MSC can be easily directed to other MSCs. After the operation is complete, the traffic is reallocated to the original MSC. This reduces the service interruption duration and therefore improves the user satisfaction.

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Enhancement GBSS8.0 The MSC Pool feature in case of A over IP is supported. GBSS9.0 MSC pool measurements supported: The service requests sent to each MSC in the MSC pool are counted on the basis of the access method (IMSI, IMEI, or TMSI) used by the MSs. This helps the operators learn the distribution of MSs using various access methods.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The NSS must support this feature. The following M2000 feature must be activated: WOFD-230100 MSC Pool Management

8.2.4 GBFD-119701 SGSN Pool Availability This feature was introduced in GBSS8.0.

Summary With this feature, multiple SGSNs form a resource pool to provide services for the subscribers belonging to one group of BSCs.

Benefits The SGSNs in an SGSN pool share the traffic load and resources. This feature provides the following benefits: 

Increases the network capacity and saves the investment on equipment.



Implements redundancy backup and therefore improves the network reliability because the addition or deletion of an SGSN does not affect the services.

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Reduces handovers between the SGSNs because the SGSNs in an SGSN pool are logically one SGSN and therefore improves the network performance.

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Description This feature, which is similar to the MSC Pool feature, enables a maximum of 32 SGSNs to form a resource pool to provide services for the subscribers belonging to one group of BSCs. With this feature, one BSC can be connected to multiple SGSNs at the same time. In addition, the traffic on the BSC is evenly distributed to the SGSNs in the pool according to the network resource identifier (NRI) or load balancing principle. CS poolarea 2

CS poolarea 1 RAN node

RAN node

Area 1

RAN node

Area 2

RAN node

Area 3

RAN node

Area 5

Area 6

RAN node

Area 7

Area 8

PS poolarea 2

SGSN 3

SGSN 2

Area 4

RAN node

PS poolarea 1

SGSN 1

RAN node

SGSN 6

SGSN 4 SGSN 5

The routing policies are described as follows: 

Routing by network load When an MS accesses the network for the first time, it generates a random TLLI and sends it to the BSC because it does not have a local/foreign TLLI. Then, the BSC uses the load balancing algorithm to select an SGSN for the MS according to the status and available capacity of the SGSNs in the pool and routes the MS to the selected SGSN.



Routing by the NRI After an MS accesses the network for the first time, the SGSN allocates a new local TLLI that includes the NRI information associated with this SGSN to the MS. When the MS processes services, it sends the NRI information to the network through the local/foreign TLLI. Then, the BSC obtains the NRI from the local/foreign TLLI and routes the services to the SGSN corresponding to the NRI in the configuration data. Using the SGSN pool, the BSCs in the pool share a group of SGSNs. If peak hours of traffic on each BSC are different, less CN resources are required in comparison with the non-SGSN pool networking. This saves the investment in the CN equipment. When an SGSN in the SGSN pool is faulty, the new services are automatically transferred to another normal SGSN and therefore the network reliability is enhanced. When some maintenance operations such as software upgrade are performed on an SGSN in the SGSN pool, the traffic on this SGSN can be easily transferred to other SGSNs. After the operation is complete, the traffic is reallocated to the original SGSN.

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This reduces the service interruption duration and therefore improves the user satisfaction.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The SGSN must support this feature. The following M2000 feature must be activated: WOFD-230700 SGSN Pool Management

8.2.5 GBFD-116601 Abis Bypass Availability This feature was introduced in GBSS7.0.

Summary In the case of chain topology, when the power supply to a BTS fails, this feature can bypass this BTS (that is, this BTS is used only as the path) so that the signals of the lower-level BTSs can be sent to the BSC.

Benefits Chain topology is the main topology among the current networking modes. In the chain topology, if the power supply to the upper-level BTS fails, the transmission of the lower-level BTSs cannot proceed normally. With this feature, the lower-level BTSs can work normally even if the power supply to the upper-level BTS fails. Therefore, this feature provides higher reliability for the network in the chain topology, especially in the areas where the power supply fails frequently.

Description To improve the working capability of the BSS system in the areas where the power supply fails frequently, Huawei BTS provides the Abis Bypass feature. This feature is applicable in the case of chain topology. When the power supply to a BTS fails, the BTS automatically bypasses the Abis interface so that the lower-level BTSs in the chain network can work

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normally. When the power supply is recovered, the BTS and the lower-level BTSs are reset automatically.

Enhancement In GBSS8.1, this feature is supported from the 3900 series base stations.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature and the following feature are mutually exclusive: GBFD-116701 16Kbit RSL and OML on Abis Interface GBFD-118601 Abis over IP GBFD-118611 Abis IP over E1/T1 GBFD-118401 Abis Transmission Optimization GBFD-117801 Ring Topology GBFD-117702 BTS Local Switch GBFD-117301 Flex Abis(in TDM network, this feature is exclusive only with Ring Topology is using) Dependency on other NEs This feature cannot be used together with DXX.

8.2.6 GBFD-113721 Robust Air Interface Signalling Availability This feature was introduced in GBSS8.1.

Summary With this feature, the FACCH frames and SACCH frames are sent repeatedly when the radio quality is poor. Therefore, this feature enhances the anti-interference capability of the signaling links on the FACCH and SACCH and increases the possibility that the MS and the BSC successfully receive the signaling messages. This feature involves repeated sending of downlink FACCH frames and repeated sending of uplink/downlink SACCH frames.


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

Repeated sending of FACCH frames improves the FACCH link performance of the ordinary MS by 2 dB and the FACCH link performance of the MS in R6 version by 4 dB to 5 dB.



Repeated sending of SACCH frames improves the SACCH link performance of the ordinary MS by 4 dB to 5 dB.



The improvement in the FACCH and SACCH performance reduces call drops and increases the accuracy of the handover decision and power control decision of the BSC.

Description In the network with tight frequency reuse and poor radio transmission performance, the messages sent through the FACCH frames or the SACCH frames may be lost because of the high bit error rate on the Um interface. This feature involves repeated sending of downlink FACCH frames and repeated sending of uplink/downlink SACCH frames. 

Repeated sending of downlink FACCH frames When the receive quality in the downlink measurement report is lower than the specified threshold, the BTS determines whether to resend the FACCH frames. The repeated sending of downlink FACCH frames can increase the possibility that the MS successfully receives the signaling messages.



Repeated sending of uplink/downlink SACCH frames If the BTS detects that the SACCH frames are incorrectly decoded, it instructs the MS to resend the recent SACCH frame. If the MS detects that the SACCH frames are not correctly decoded, it instructs the BTS to resend the recent SACCH frame.

With this feature, the voice quality is slightly affected because the signaling messages are sent through frame stealing. When the radio quality is poor, repeated sending of signaling messages in the downlink can reduce call drops caused by decoding failure. Repeated sending of signaling messages in the uplink can increase the accuracy of the handover decision and power control decision of the BSC by increasing the possibility of correctly decoding the uplink measurement reports.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The MS and the BTS must support this feature.

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8.2.7 GBFD-117803 Abis Transmission Backup Availability This feature was introduced in GBSS8.1.

Summary This feature applies to Abis over TDM or Abis over IP mode to improve network reliability. In Abis over TDM mode, this feature switches services to standby satellite transmission links if terrestrial TDM transmission links over the Abis interface become faulty due to an exception caused by a natural disaster. In Abis over IP mode, this feature allows users to configure two transmission links over the Abis interface: an IP over E1 transmission link based on the existing TDM or SDH network and an IP over FE transmission link based on the IP network.

Benefits This feature improves the reliability of the Abis interface when TDM transmission or IP over FE transmission is applied over the Abis interface.

Description During a natural disaster, GBSS devices sometimes work normally; however, the GSM network cannot provide services because of terrestrial transmission interruption. With this feature, the standby satellite transmission links can be used for communication between the BSC and the BTS so that GSM devices can provide services in emergency conditions. When this feature is enabled, satellite transmission links are used as backup for terrestrial transmission links. When the terrestrial transmission link is faulty, the GBSS automatically uses the satellite transmission link. When the active terrestrial transmission links recover, the GBSS devices can be triggered by hand to make the transmission link rollback to use the terrestrial transmission links again. With this feature, no information is transmitted over the standby satellite transmission links. This saves satellite link bandwidth. The satellite transmission link switchover applies only to the Abis over TDM mode.

Enhancement GBSS14.0 Standby Abis transmission links In Abis over IP mode, this feature allows users to configure two transmission links over the Abis interface: an IP over E1 transmission link based on the existing TDM or SDH network and an IP over FE transmission link based on the IP network. The two transmission links over the Abis interface work in active/standby mode, and services are carried only on the active transmission link in normal conditions. The active transmission link uses Link Access Procedure on the D channel (LAPD) detection and the standby transmission link uses User Datagram Protocol (UDP) Ping detection. If the active transmission link becomes faulty, the GBSS automatically switches all services over the Abis interface to the standby transmission link. Services are interrupted for less than 1 minute

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during the switchover. When the original active transmission link recovers, the GBSS automatically switches all services back to it. If the standby transmission link becomes faulty, services are not switched over but an alarm is reported, notifying that the standby transmission link is faulty. Standby Abis transmission links apply only when one transmission mode (IP over FE or IP over E1) is used between the BTS and the BSC. Standby Abis transmission links do not apply when the transmission mode is changed by a router over the bearer network. For example, the transmission mode is changed from IP over E1 to IP over FE.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features Satellite transmission link switchover depends on the following features: GBFD-113901 Satellite Transmission over Abis Interface GBFD-117801 Ring Topology Abis transmission link backup depends on the following features: GBFD-118601 Abis over IP GBFD-118611 Abis IP over E1/T1 Dependency on other NEs None

8.2.8 GBFD-113725 BSC Node Redundancy Availability This feature was introduced in GBSS9.0.

Summary The BSC Node Redundancy feature improves the reliability and robustness of the network by providing the 1+1 backup on the BSC level.

Benefits The BSC Node Redundancy feature improves the reliability and robustness of the GSM network, reduces the duration of service interruption caused by a single-point fault, and therefore improves the service quality.

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Description The BSC controls the radio resources of every BTS. Once the BSC is faulty, all the BTSs controlled by this BSC cannot access the network and the connection cannot be set up in the coverage area of this BSC. In addition, the fault on the communication link between the BSC and the BTS will hamper the functioning of the BSC. As a result, the network in this coverage area of the BTS may break down. The BSC Node Redundancy feature provides the backup scheme on the BSC level to avoid the previous problems. The BSC supports the 1+1 backup mode. The principles of 1+1 backup are as follows: A BTS is configured with two sets of transmission links, which are connected to the main BSC and sub-BSCs respectively. All the data concerning the BTS, cell, neighboring cell is backed up on the main BSC and sub-BSCs. The BTSs are generally controlled by the main BSC. Once the main BSC is faulty, the BTS attempts to connect to the sub-BSC and continues to provide services. In this manner, a BTS has two sets of Abis interfaces (including two sets of control plane links, user plane links, and OM links). In addition, two control BSCs are available to implement cold backup (calls are not protected). Therefore, the system reliability is improved. The main and sub-BSCs do not work in active/standby mode. Normally, they are both in operation state, therefore the equipment can obtain maximal efficiency. If one BSC is faulty, the other one can take over all the BTSs under the faulty BSC to prevent the BTSs from being out of service and therefore avoid single-point faults on the BSC level. When one BSC becomes faulty, the overall service processing capability (including CS Erlang and PS throughput) of the pair of BSCs in 1+1 backup mode is decreased.

Enhancement None

Dependency Dependency on BSC hardware A/GB/Abis/Inter-BSC interface must be IP mode, using IP interface Board. Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature relies on the following features: GBFD-118601 Abis over IP or GBFD-118611 Abis IP over E1/T1 GBFD-118602 A over IP or GBFD-118622 A IP over E1/T1 GBFD-118603 Gb over IP GBFD-115301 Local Multiple Signaling Points Dependency on other NEs The following M2000 feature must be activated: WOFD-231100 BSC Redundancy Management–GBSS

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8.2.9 GBFD-113726 TC POOL Availability This feature was introduced in GBSS9.0.

Summary With this feature, multiple BSCs share the same TC resources in the TC pool. This increases the efficiency of the codec hardware.

Benefits 

The efficiency of the codec hardware is increased because multiple BSCs share the same resources in one TC pool. For the small-capacity BSC, 20% to 30% TC codec resources can be saved.



Saving room is possible. For example, three small-capacity GTCSs require three cabinets. In TC pool mode, three GTCSs require only one cabinet. In this manner, 40% to 60% area in the equipment room can be saved.

Description In general, one GTCS belongs to only one BSC and is used to process the CS services of this BSC. The GTCSs in different BSCs are not associated with each other. In this kind of network topology, the TC resources cannot be multiplexed among multiple BSCs. In the scenario where multiple BSCs with small capacity are grouped into a network, the TC resources are greatly wasted. In TC pool mode, multiple BSCs share a TC pool of large capacity. The typical network topology is shown in the following figure. Abis BSC1 (main BSC)

MSC1 Ater

E1/ST M

BSC3(sub BSC)

TM -1

E1 /ST M1

E1 /S

BSC2(sub BSC)

A

-1

TC(Pool)

MSC2

E1/STM-1 -1 E1/STM TM

1

-1 TM /S E1

/S E1

MSC3

BSC4(sub BSC)

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The TC pool adapts to the mode that the GTCS is separated from the BSC cabinet and is connected to the BSC through the Ater interface. The codec resources in the TC pool are shared by the main BSC and sub-BSCs, which work in load sharing mode. When a voice processing board is faulty, it will out of service automatically. In this manner, the subsequent CS services are not affected, which improves the system reliability. The speech versions supported by the TC pool are FR, EFR, HR, AMR-FR, and AMR-HR. To synchronize the clock of the GSM network, the main BSC and sub-BSCs in a TC pool should use the same clock source. In addition, a BSC can be connected to only one TC pool. One TC pool supports a maximum of 16 BSCs.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-118602 A over IP GBFD-118622 A IP over E1/T1 GBFD-116902 Ater Compression Transmission Dependency on other NEs None

8.2.10 GBFD-113728 OML Backup Availability This feature was introduced in GBSS9.0.

Summary This feature supports configuration of the OMLs on two independent E1s. In this case, only one OML works at one time. When the OML in working mode is faulty, the BTS uses another OML. In this way, the BTS can work without being out of service.

Benefits This feature provides better robustness for the BTS. When the OML is broken because the transmission links are faulty, this feature ensures that the BTS is not reset and the cell is not out of service.

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Compared with the ring topology that requires twice the amount of resources, this feature requires only a few timeslots. In addition, configuration of the OML on two E1s can ensure the stable operation of the BTS system with a little consumption of the transmission resources.

Description The OML is the operation and maintenance link between the BSC and the BTS. When the OML is faulty, the entire BTS cannot work. With this feature, two OMLs can be configured on two independent E1s. When the OML in working mode is faulty, the BTS uses another OML. Therefore, the BTS and cell can continue to work without being out of service due to transmission fault or port fault. When this feature is used, the BSC configures one OML on port 0 and another OML on port 1. After the BTS is reset, it attempts to establish links on the two ports in turn. If the BTS establishes the OML on one port, it always uses the OML on this port unless the BTS is reset or the OML is broken. When the established OML is broken, the BTS attempts to establish an OML on another port. If the establishment is successful, the BSC triggers the OML switchover. After the OML switchover, the RSL, TCH, idle timeslot, and monitoring timeslot are not switched over. That is, for port 0 and port 1, if the transmission link or port where the working OML is located is faulty, all the TRX channels, idle timeslots, and monitoring timeslots become unavailable. The normal port, however, can continue to provide services. Therefore, the BTS and cell can continue to work without being out of service. The OM personnel can use the MML command to enable this feature. This feature is supported by the BTS in TDM and HDLC modes. This feature is not supported by the BTS in IP mode.

Enhancement None

Dependency Dependency on MBTS hardware None Dependency on MBSC hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features This feature is mutually exclusive with the following features: GBFD-117801 Ring Topology GBFD-116601 Abis Bypass GBFD-116701 16Kbit RSL and OML on Abis Interface GBFD-118601 Abis over IP GBFD-118611 Abis IP over E1/T1 GBFD-118401 Abis Transmission Optimization Issue V0.5 (2011-08-30)


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Dependency on other NEs The BTS must support this feature.

8.2.11 GBFD-511002 Access Control Class (ACC) Availability This feature was introduced in GBSS12.0.

Summary With this feature, the BSC can control the number of MSs accessing the network at a certain time by allowing only the MSs of a certain ACC class to access the network. In this manner, the BSS overload or MSC overload caused by numerous MSs' simultaneous access to the network can be prevented. This feature uses a sliding window mechanism to enable the MSs of all ACC classes to access the network. Therefore, radio services are available for all MSs, especially in emergency cases.

Benefits In emergency cases such as natural disasters, the traffic volume in the network sharply increases. It may increase to an extent that far exceeds the network capacity. In such a case, users have difficulties in making calls, and the radio network may even be down. The Access Control Class (ACC) feature controls the number of MSs accessing the network in emergency cases by allowing only the MSs of a certain ACC class to access the network. It ensures the normal operation of the radio network.

Description When a subscriber is registered with the GSM network, it is assigned a common ACC class and a special ACC class. The MSs of a certain ACC class are informed of being allowed or of not being allowed to access the network by the GSM system through system information. The ACC feature uses a window sliding mechanism to allow only the MSs of a certain ACC class to access the network at a certain time. The size of the sliding window and the speed of window motion depend on the operator's configuration policy.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware None Dependency on other GBSS features None Dependency on other NEs

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None

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O&M Experience

9.1 O&M 9.1.1 GBFD-113729 Adaptive Transmission Link Blocking Availability This feature was introduced in GBSS13.0.

Summary If the transmission quality of an E1 link over the Abis interface deteriorates, the BSC actively blocks this E1 link, so that the link no longer carries new services. After the transmission quality of the E1 link becomes desirable, the BSC unblocks the link.

Benefits 

This feature ensures the service quality by not allocating calls to E1 links with undesirable transmission quality.



This feature reduces the costs in network monitoring and maintenance.

Description The transmission quality, especially the quality of microwave transmission, is vulnerable to bad weather such as raining. Once an E1 link is faulty, all services carried on the link will be affected, which leads to degraded service quality and increased call drop rate. To prevent the preceding problem, the BSC monitors transmission quality in real time. The BSC automatically blocks an E1 link if the transmission quality is lower than the specified threshold. After being blocked, the E1 link carries only the ongoing services and no longer carries new services. After the transmission quality of the E1 link becomes desirable, the BSC unblocks the link.

Enhancement None


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Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features It is mutually exclusive with the following features: GBFD-118601 Abis over IP Dependency on other NEs None

9.1.2 GBFD-114701 Semi-Permanent Connection Availability This feature was introduced in GBSS6.1.

Summary When the semi-permanent connection feature is enabled, some of the idle E1 timeslots in the existing network can be used to transmit information such as service hall information, alarm information on the BTS AC power supply, and other maintenance information.


Using semi-permanent connection prevents the arrangement of new paths to transmit the external maintenance information. As a result, the transmission networking is simplified, the maintenance cost is reduced, and thereby the transmission cost is greatly reduced.



With this feature, the semi-permanent connections on multiple GMPS/GEPS converge on one E1 through the timeslot switching on the interface boards. Therefore, the investment in the transmission and timeslot switching devices (DXX devices) are saved.

Description When some data that does not have a high requirement for the transmission bandwidth needs to be transmitted from one terminal to another terminal, the idle transmission resources in the GSM network can be used. Semi-permanent connection refers to the situation that the information collected on the E1 timeslots of the receiver is exchanged to the E1 timeslots of the transmitter through the intra-BSS timeslot switching function. The collected information is transparently transmitted within the BSS. The transparent transmission path is retained permanently without change in the link configuration. The timeslot switching process is shown in the following figure.

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Huawei BSS supports the semi-permanent connection at four rates: 8 kbit/s, 16 kbit/s, 32 kbit/s, and 64 kbit/s. The access points of all paths carrying the semi-permanent connections into the BSS are E1 interface timeslots. The BSS switches over multiple semi-permanent connections to one E1 and then exports the collected maintenance information to the devices in the external network. Huawei BSS supports two types of semi-permanent connections: common semi-permanent connection and monitoring timeslot. 

Common semi-permanent connection In the case of common semi-permanent connection, the interface boards in the BSC are used for input and output, and only the BSC is involved in the timeslot switching function from the input timeslot to the output timeslot. With common semi-permanent connection, the external information of the BSC equipment room can be sent to the CN equipment room using the transmission resources over the A interface. In addition, simple DXX devices can be used to combine multiple timeslots into one E1 for transmission. As a result, the transmission cost is reduced and the DXX device investment is saved.



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With monitoring timeslot, the timeslot switching function is performed by the BTS and the BSC. One end of the monitoring timeslot path is connected to the BTS port, and the other end is connected to the interface board in the BSC. The monitoring timeslot is used for transmitting external data (such as the information about the alarm of the power supply) on the BTS side. In BTS cascading, the upper-level BTS is also involved in the timeslot switching function to transparently transmit the monitoring timeslot data for the lower-level BTS.

Enhancement GBSS8.0 This application enhancement supports configuration of monitoring timeslots at the transmission optimization site.

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features When monitoring timeslots are used at the transmission optimization site, E1 connection paths should be configured between the GEHUB and the GEIUB/GOIUB. Dependency on other NEs None

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9.1.3 GBFD-116401 End-to-End MS Signaling Tracing Availability This feature was introduced in GBSS6.1.

Summary This feature enables you to collect the information about the specified MS if required and then collect the traced faults in a specific network element using only a few system resources. In this manner, you can rectify the faults effectively.

Benefits It is difficult to locate the service faults in MSs because the communications network becomes increasingly complicated. You can detect the section where the fault occurs only when the information about the whole process of one MS is collected. By using the end-to-end MS signaling tracing feature, you can completely record the service activities of an MS and then locate the section where the fault occurs. The recorded information covers all the network elements involved in the service of the MS. If the traced MS is properly defined, the valid location information can be obtained without using a large amount of processing and transmission resources of the system in the whole tracing process.

Description With this feature, you can create or delete a tracing task in the HLR. The HLR sends the tracing activation message to the MSC/VLR where the MS is located. When the traced MS initiates services, the MSC notifies the BSC to perform tracing. When the MS is switched over to a new MSC, location update is initiated. Then the HLR sends a tracing activation message to the new MSC/VLR and the tracing task of the original MSC is complete. When receiving the message of starting a tracing task from the MSC, the BSC traces information about all the interfaces and then saves the information to the BAM. The information is saved as a .tmf file, which is used for interface tracing on the BSC LMT. The file can be browsed through the function of interface tracing review on the BSC LMT. When browsing the information about a traced MS, you can choose a time segment and choose the message field to be viewed through a message filter window. The BSC supports a maximum of 64 tracing tasks (including single-MS signaling tracing, interface signaling tracing, and end-to-end MS signaling tracing tasks). There should be at least 16 end-to-end MS signaling tracing tasks. If the number of existing end-to-end MS signaling tracing tasks reaches or exceeds 16, determine whether the total number of tasks reaches the upper threshold when creating an end-to-end MS signaling tracing task. If the total number does not reach the upper threshold, you can create more tasks. If the total number reaches the upper threshold, task creation fails.

Enhancement None


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None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other GBSS features None Dependency on other NEs The M2000 and the CN must support this feature. WOFD-190600 GBSS Enhanced Subscriber Tracing WOFD-191400 G&U CS Subscriber Tracing

9.1.4 GBFD-510901 GSM/3G Neighboring Cell Automatic Optimization Availability This feature was introduced in GBSS9.0.

Summary By using the Nastar, a network optimization tool, you can find out the missing or redundant neighboring 2G/3G cells of the GSM serving cell.

Benefits This feature helps optimize the existing network, increase intra-system and inter-system handover success rate, optimize the GSM network performance, and improve the user experience.

Description Assuming that the operator can provide both the 2G network and the 3G network, the 3G network can be the WCDMA network or the TD-SCDMA network, if the 3G cells are configured as the neighboring cells of the 2G cells and the neighboring cell relationships are configured properly, the quality of the GSM network can be improved and the user can enjoy abundant 3G services. If the neighboring cell relationships are configured improperly, there are missing or redundant neighboring cells. The redundant neighboring cells make the MS cannot quickly search for the useful cells. If the required neighboring cells are not configured, some areas may not be covered, affecting the handover success rate. This feature should be supported by the MS, BSC, M2000, and Nastar. The M2000 sends the list of cells whose neighboring cells should be optimized, the list of neighboring 2G/3G cells that should be measured by the cells, and the related measurement parameters to the BSC. Then, the BSC regularly sends the information about the neighboring 2G/3G cells to the MS. After the MS measures a neighboring cell, the information about the neighboring 2G/3G cell is sent to the BSC through the measurement reports. The BSC records the neighboring cell information to the traffic statistics and sends the statistics to the M2000. The Nastar obtains the statistics from the M2000 and analyzes the statistics to obtain the missing and redundant neighboring cells as shown in the following figure.

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Huawei BSS supports two types of neighboring 3G cells: WCDMA neighboring cells (FDD neighboring cells) and TD-SCDMA neighboring cells (TDD neighboring cells). One serving cell supports only one type of neighboring cell.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware For the dependency on BTS hardware, see the GBSS14.0 Feature List. Dependency on other functions of the GBSS None Dependency on other NEs This feature should be supported by the M2000 and Nastar, and depends on the following features: GNFD-200020 GSM Neighboring Cell Analysis GNFD-200090 GSM Frequency Analysis WOFD-270100 Data Collection of Neighboring GBSS Cells This feature can be enabled only when the related features of the GBSS and Nastar are bought.

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9.2 Visualization & Data Collection 9.2.1 GBFD-511701 Radio Measurement Data Interface for Navigation Availability This feature was introduced in GBSS13.0.

Summary After this feature is enabled, the BSC sends radio measurement data to the Vendor Network Probe (VNP) through a specified interface, and the VNP sends the data to a navigation service provider, for example, TomTom. Based on analysis of the radio measurement data, the navigation service provider provides traffic and congestion information for subscribers.

Benefits With this feature, the BSC can provide radio measurement data to help telecom operators and navigation service providers jointly deploy navigation services.

Description Based on TCP/IP, the BSC reports radio measurement data to the VNP through a specified interface, which is a private interface currently. The radio measurement data is reported to the VNP upon any of the following events: 

A subscriber accesses a cell under the BSC.



The TA changes.



A cell reselection occurs.



A call connection is released.



An incoming or outgoing BSC handover occurs.

The collection unit (CU) of the navigation service provider then collects radio measurement data from the VNP.

Enhancement None

Dependency Dependency on BSC hardware None Dependency on BTS hardware None Dependency on other GBSS features

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None Dependency on other NEs To support this feature, the BSC can be connected to Huawei Nastar-TS V100R001C00 or Ericsson VNP. Ericsson VNPs use a message format of Category3 or later versions. Huawei VNPs use a message format of Category4 versions.

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Acronyms and Abbreviations

Numerics 3G

3 rd Generation Mobile Communication System

3GPP2

3rd Generation Partnership Project 2

8PSK

8 Phase Shift Keying

A AAL

ATM Adaptation Layer

AB

Access Burst

AbisPC

Abis interface Port Control

ACCH

Associated Control Channel

ACS

Active Codec Set

AEC

Acoustic Echo Cancellation

AFC

Automatic Frequency Correction

AGCH

Access Grant Channel

AGT

Agent

AICP

A Interface Common Procedure

ALC

Automatic Level Control

ALM

Alarm

AMR

Adaptive Multi Rate

AMRFS

Adaptive Multi Rate Full Speed

AMRHS

Adaptive Multi Rate Half Speed

ANR

Automatic Noise Restraint

APM

Advanced Power Module

APN

Access Point Name


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APP

Application

APS

Automatic Protection Switchback

ARP

Address Resolution Protocol

ARQ

Automatic Request for retransmission

ATM

Asynchronous Transfer Mode

ATT

Attach-Detach allowed

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B BA

BCCH Allocation

BAM

Back Administration Module

BBU

Baseband Control Unit

BCCH

Broadcast Control Channel

BEP

Bit Error Probability

BER

Bit Error Rate

BFD

Bidirectional Forwarding Detection

BG

Border Gateway

BIU

Base station Interface Unit

BKP

Backplane Board

BM

Basic Module

BMACT

Basic Module Active Codec Type

BMRC

BM Resource Control

BOM

Bill Of Materials

BQ

Bad Quality

BR

Backward Reporting

BSC

Base Station Controller

BSCOM

BSC O&M

BSIC

Base Station Identity Code

BSSAP

Base Station Subsystem Application Part

BSSAP+

Base Station Subsystem Application Part Plus

BSSGP

Base Station System GPRS Protocol

BTS

Base Transceiver Station

BTSCP

BTS Common Processing

BTSOM

BTS O&M

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BTSTRC

BTS Transmission Resource Control

BVC

BSSGP Virtual Connection

BVCI

BSSGP Virtual Connection Identifier

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C CACS

Common Active Codec Set

CAPEX

Capital expenditures

CBC

Cell Broadcast Center

CBCH

Cell Broadcast Channel

CBE

Cell Broadcast Entity

CBIP

Cell Broadcast Interface Process

CBSC

CDMA2000 Base Station Controller

CCB

Call Control Block

CCCH

Common Control Channel

CCU

Channel Codec Unit

CDB

Cell Broadcast Database

CDU

Combining and Distribution Unit

CECCM

CEll CCM process

CECHM

CEll Channel Management

CEGPRS

Cell GPRS Processing

CELP

Code-Excited LPC

CESP

Cell Service Process

CGI

Cell Global Identifier

CHR

Call History Record

CI

Cell Identify

CI

Cell Identity

CIC

Circuit identification code

CIU

Circuit Interface Unit

CM

Configuration Manage

CMI

Codec Mode Indication

CMR

Codec Mode Request

CPRI

Common Protocol Radio Interface

CPUX

xpu CPU eXtended

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CRC

Cyclic Redundancy Check

CRDLC

Call Radio Link Control

CS

Coding Scheme

CSD

Circuit Switched Data

CV

Countdown Value

CW

Call Wait

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D DACS

Distant Active Codec Set

DBAPI

DataBase API

DBG

Debug

DBMI

DataBase Management Interface

DBUS

Data-BUS

DCS 1800MHz

Digital Cellular System 1800MHz

DHCP

Dynamic Host Configuration Protocol

Diffserv

Differentiated Services

DOPRA

Distributed Object-oriented Programmable Realtime Architecture

DPU

Data Process Unit

DRFU

Double Radio Filter Unit

DRX

Discontinuous Reception

DSCP

DiffServ Code Point

DSPC

DSP for transCoder

DSPI

DSP for Integrated

DSPOM

DSP O&M

DSPOM_AGT

DSP OM Agent

DSPP

DSP for Pcu

DT

Debug Terminal

DTAP

Direct Transfer Application Part

DTCB

Distance To Cell Board

DTM

Dual Transfer Mode

DTM

Dual Transfer Mode

DTMF

Dual-Tone Multi-frequency

DTX

Discontinuous Transmission

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E ECSD

Enhanced Circuit Switched Data

ECT

Explicit Call Transfer

EDA

Extended Dynamic Allocation

EFR

Enhanced Full Rate

EFR

Enhanced Full Rate

E-GSM

Extended GSM-900 Band (includes Standard GSM-900 band)

EICC

Enhanced Interference Counteract Combining

EML

Extended Operation and Maintenance Link

EM-layer

Element Management-layer

eMLPP

Enhanced multi-level precedence and preemption service

EMR

Enhanced Measurement Report

ES

Errored Second

ESL

Extend Signaling Link

ESR

Errored Second Ratio

ETHERNET OAM

ETHERNET OAM

ETRAU

EGPRS TRAU

F FACCH

Fast Associated Control Channel

FAI

Final Ack Indicator

FBI

Final Block Indicator

FCS

Frame Check Sequence

FDR

Frequency Domain Reflectometer

FE

Fast Ethernet

FEC

Forward Error Correction

FER

Frame Erase Ratio

FER

Frame Erase Ratio

FH

Frequency Hopping

FIR

Finite Input Response

Flex Abis

Flex Abis

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FM

Forward Monitoring

FN

Frame Number

FR

Frame Relay

FR

Full Rate

FR AMR

Full Rate AMR

FS

Full Speed

FTP

FILE TRANSFER PROTOCOL

FTPS

FTP Over SSL

FUC

Frame Unit Controller

Public

G Gb

Gb interface

GBSC

GSM Base Station Controller

GBSS

GSM Base Station Subsystems

GDPUC

GDPU for transCoder

GDPUX

GDPU for eXtensible use

GE

Gigabit Ethernet

GEHUB

GSM E1/T1 High level Data Link Control Unit for aBis

GEIUB

GSM E1/T1 Interface Unit for aBis

GEPUG

GSM E1/T1 Packet Unit for Gb

GFGUA

GSM FE/GE electronic interface Unit for A

GFGUB

GSM FE/GE electronic interface Unit for Abis

GFGUG

GSM FE/GE electronic interface Unit for Gb

GGCU

GSM General Clock Unit

GGOUA

GSM GE optical interface Unit for A

GGOUB

GSM GE optical interface Unit for Abis

GMSK

Gaussian Minimum Shift Keying (modulation)

GOMU

GSM Operation and Maintenance Unit

GPRS

General Packet Radio Service

GPS

Global Position System

GRFU

GSM Radio Frequency Unit

GRLM

GPRS Radio Link Management

GRRM

GPRS Radio Resource management

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GSCU

GSM Switching and Control Unit

GSM-R

Railways Global System for Mobile Communication

GSN

Gigabyte System Network

GTMU

GSM Timing and Main control Unit

GTNU

GSM TDM switching Network Unit

GTRAU

GPRS TRAU

GTRAUE

GPRS TRAU Enhancement

GTRAUIP

GPRS TRAU IP transmission

GUI

Graphical User Interface

GXPUM

GSM eXtensible Processing Unit for Main service

Public

H HDLC

High-Level Data Link Control

HLR

Home Location Register

HMC

High Multislot Classes

HR

Half Rate

HR AMR

Half Rate AMR

HS

Half Speed

HSCSD

High Speed Circuit Switched Data

HTTP

Hypertext Transfer Protocol

HubBTS

Hub Base Transceiver Station

I IACS

Immediate Active Codec Set

IBCA

Interference Based Channel Allocation

ICB

Inner Combiner bypass

ICC

Interference Rejection Combining

ICMP

Internet Control Messages Protocol

IDC

Instance Distribution Control

IMEI

International Mobile Equipment Identity

IMSI

International Mobile Subscriber Identity

IP

Internet Protocol

IR

Incremental redundancy

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ISI

Inter-Symbol Interference

IWF

Interworking Function

Public

K KPI

Key Performance Index

L L3IF

Layer-3 Interface

LA

Link adaptation

LAC

Location Area Code

LACS

Local Active Codec Set

LAI

Location Area Identity

LAN

Local Area Network

LAPD

Link Access Protocol on D channel

LLC

Logic Link Control

LMT

Local Maintenance Terminal

LRM

Local Resource Management

M M3UA

MTP3 User Adaptation Layer

MA

Mobile Allocation

MAC

Medium Access Control

MACS

Maximum number of Codes Modes in the Active Codec Set

MAIO

Mobile Allocation Index Offset

MCS

Modulation and Coding Scheme

MGW

Media Gateway

MML

Man-Machine Language

MNC

Mobile Network Code

MOS

Mean Opinion Scores

MPTY

MultiParty

MR

Measurement Report

MSC

Main Switching Center

MSIC

MS Instance Control

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MSIP

MS Instance Processing

MSISDN

Mobile Station International ISDN Number

MTBF

Mean Time Between Failures

MTLS

Mapping and Transfer between LAPD entity and Service entity

MTP2

Message Transfer Part 2

MTP3

Message Transfer Part 3

MTSS

Mapping and Transfer between SCCP entity and Service entity

Public

N NACC

Network Assisted Cell Change

NAT

Network Address Translation

NCH

Notification Channel

NLN

Notification List Number

NM

Network Management

NMS

Network Management System

NRI

Network Resource Identifier

NS

Network Service

NSE

Network Service Entity

NSEI

Network Service Entity Identifier

NSS

Network Subsystem

NSVC

Network Service Virtual Connection

O OACS

Optimized Active Codec Set

OMC

Operations & Maintenance Centre

OML

Operation and Maintenance Link

OPEX

Operating Expense

P PACCH

Packet Associated Control Channel

PAGCH

Packet Access Grant Channel

PARC

Platform of Advanced Radio Controller

Pb

PCU-BSC interface link

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PBCCH

Packet Broadcast Control Channel

PBGT

Power Budget Handover

PBIP

Pb Interface Processing

PBT

Power Boost Technology

PCCCH

Packet Common Control Channel

PCH

Paging Channel

PCM

Pulse Code Modulation

PCS 1900MHz

Personal Communications Service 1900MHz

PCU

Packet Control Unit

PDCH

Packet Data Channel

PDH

Plesiochronous Digital Hierarchy

PDTCH

Packet Data Traffic Channel

PDU

Power Distribution Unit

PGC

Paging Control

P-GSM

Primary GSM-900 Band

PIU

Packet Interface Unit

PLMN

Public Land Mobile Network

PMU

Power Management Unit

PoC

Push to Talk over Cellular

PPCH

Packet Paging Channel

PQ

Priority Queue

PRACH

Packet Random Access Channel

PS

Packet Switch Domain

PSI

Packet SI Status

PSU

Power Supply Unit

PT

Payload Type

PTCCH

Packet Timing Advanced Control Channel

P-TMSI

Packet-Temporary Mobile Station Identity

PTP

Point-To-Point

PTRAU

Packet Transcoder/Rate Adaptor Unit

PTT

Push-To-Talk

PTU

Packet Transmission Unit

PVC

Permanent Virtual Connection

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Public

Q QoS

Quality of Service

QTRU

Quadruple Transmission Receiver Unit

R RACH

Random Access Channel

RC

Resource control & Common procedure

RFC

Request for Comments

RFU

Radio Frequency Unit

RIM

Reference Information Manager

RLC

Radio Link Control

RNC

WCDMA Radio Network Controller

RPE-LTP

Regular Pulse Excitation-Long Term Prediction

RQI

Radio Quality Indicator

RR

Radio Resources

RRBP

Relative Reserved Block Period

RSL

Radio Signaling Link

RTCP

Real-Time Transport Control Protocol

RTP

Real-Time Transport Protocol

RX

Reception

S SACCH

Slow Associated Control Channel

SAIC

Single Antenna Interference Cancellation

SAPI

Service Access Point Identifier

SCCP

Signaling Connection Control Part

SCH

Synchronization Channel

SCTP

Stream Control Transmission Protocol

SCU

Switch Control Unit

SDH

Synchronous Digital Hierarchy

SESR

Severely Errored Second Ratio

SGSN

Serving GPRS Support Node

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SID

Silence Descriptor

SIGTRAN

Signaling Transport

SMC

Short Message Centre

SMLC

Serving Mobile Location Center

SMS

Short Message Service

SMSCB

Public

Short Message Service Cell Broadcast

SONET

Synchronous Optical Network

SP

Service Provider

SPHY

Single PHY

SSL

Security Socket Layer

STP

Signaling Transfer Point

T TA

Timing Advanced

TBF

Temporary Block Flow

TC

TransCoder

TCEC

The TRAN Circuit Emulation Card

TCH

Traffic Channel

TCHF

Traffic Channel Full rate

TCP/IP

Transfer Control Protocol /Internet Protocol

TD-SCDMA

Time Division-Synchronous Code Division Multiple Access

TEI

Terminal Endpoint Identifier

TFI

Temporary Block Flow Identifier

TFO

Tandem Free Operation

TGPU

TRAN GBTS Package Process Unit

THP

Traffic handle Priority

TLLI

Temporary link level identity

TLS

Transport Layer Security

TMN

Telecommunication Management Network

TMSI

Temporary Mobile Subscriber Identifier

TMU

Timing/transmission and Management Unit

TNU

TDM switching Network Unit

TOP

TDM Over Packet

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TPEC

The TRAN Packet over E1/T1 Card

TRAU

Transcoder & Rate Adaptation Unit

TRAUE

TRAU Enhancement

TRAUIP

TRAU IP transmission

TRC

Trace

TrFO

Transcoder Free Operation

TRM

Transport Resource Management

TRU

Transmission Receiver Unit

TRX

Transceiver

TSU

TDM Switching network Unit

TSYN

TRAU Synchronization Unit

Public

U UDP

User Datagram Protocol

UMTS

Universal Mobile Telecommunications System

UOIP

User traffic Data Over IP

UOP

User Traffic Data Over Packet

USCU

Universal Satellite card and Clock Unit

USF

Uplink Status Flag

V VAD

Voice Activity Detector

VBS

Voice Broadcast Service

VGCS

Voice Group Call Service

VISP

Versatile IP and Secure Platform

VLAN

Virtual LAN

VLR

Visitor Location Register

VoIP

Voice over IP

VPN

Virtual Private Network

VQI

Voice Quality Index

W WAN

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WBBP

WCDMA Baseband Processing unit

WCDMA

Wideband CDMA

WFQ

Weighted Fair Queuing

WMPT

WCDMA Main Processing Transmission unit

WRED

Weighted Random Early Detection

WRR

Weighted Round Robin

Public

X XPUX

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GBSS14.0 Optional Feature Description

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