Handover.pdf

Handover GBSS12.0

Feature Parameter Description

Issue

01

Date

2010-06-30

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.

Trademarks and Permissions and other Huawei trademarks are trademarks of Huawei Technologies Co., Ltd. All other trademarks and trade names mentioned in this document are the property of their respective holders.

Notice The purchased products, services and features are stipulated by the contract made between Huawei and the customer. All or part of the products, services and features described in this document may not be within the purchase scope or the usage scope. Unless otherwise specified in 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 the warranty of any kind, express or implied.

Huawei Technologies Co., Ltd. Address:

Huawei Industrial Base Bantian, Longgang Shenzhen 518129 People's Republic of China

Website:

http://www.huawei.com

Email:

[email protected]

Contents 1 Introduction ................................................................................................................................1-1 1.1 Scope ............................................................................................................................................ 1-1 1.2 Intended Audience ........................................................................................................................ 1-1 1.3 Change History.............................................................................................................................. 1-1

2 Overview .....................................................................................................................................2-1 3 Technical Description ..............................................................................................................3-1 3.1 Measurement Report Processing.................................................................................................. 3-1 3.2 Handover Preprocessing ............................................................................................................... 3-2 3.3 Handover Decision Based on Handover Algorithm I ..................................................................... 3-7 3.3.1 Quick Handover .................................................................................................................... 3-7 3.3.2 TA Handover ......................................................................................................................... 3-9 3.3.3 BQ Handover ...................................................................................................................... 3-10 3.3.4 Rapid Level Drop Handover ................................................................................................3-11 3.3.5 Interference Handover .........................................................................................................3-11 3.3.6 Handover Due to No Downlink Measurement Report ........................................................ 3-12 3.3.7 Enhanced Dual-Band Network Handover .......................................................................... 3-13 3.3.8 Load Handover ................................................................................................................... 3-16 3.3.9 Enhanced Load Handover .................................................................................................. 3-17 3.3.10 Edge Handover................................................................................................................. 3-18 3.3.11 Fast-Moving Micro Cell Handover .................................................................................... 3-19 3.3.12 Inter-Layer Handover........................................................................................................ 3-21 3.3.13 PBGT Handover ............................................................................................................... 3-22 3.3.14 AMR Handover ................................................................................................................. 3-23 3.3.15 SDCCH Handover ............................................................................................................ 3-24 3.3.16 Other Handovers .............................................................................................................. 3-24 3.4 Handover Decision Based on Handover Algorithm II .................................................................. 3-24 3.4.1 Quick Handover .................................................................................................................. 3-26 3.4.2 TA Handover ....................................................................................................................... 3-28 3.4.3 BQ Handover ...................................................................................................................... 3-29 3.4.4 Interference Handover ........................................................................................................ 3-30 3.4.5 Handover Due to No Downlink Measurement Report ........................................................ 3-31 3.4.6 Enhanced Dual-Band Network Handover .......................................................................... 3-31 3.4.7 Load Handover ................................................................................................................... 3-34 3.4.8 Edge Handover................................................................................................................... 3-34 3.4.9 Fast-Moving Micro Cell Handover ...................................................................................... 3-35 3.4.10 Better Cell Handover ........................................................................................................ 3-37 3.4.11 Handover Between a Full-Rate TCH and a Half-Rate TCH ............................................. 3-38 3.4.12 SDCCH Handover ............................................................................................................ 3-40 3.4.13 Other Handovers .............................................................................................................. 3-40

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

ii

4 Parameters .................................................................................................................................4-1 5 Counters ......................................................................................................................................5-1 6 Glossary ......................................................................................................................................6-1 7 Reference Documents .............................................................................................................7-1

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GSM BSS Handover

1 Introduction

1 Introduction 1.1 Scope This document describes the overall procedure of Huawei handover algorithms and the specific handover decisions.

1.2 Intended Audience It is assumed that users of this document are familiar with GSM basics and have a working knowledge of GSM telecommunication. This document is intended for: 

Personnel working on Huawei GSM products or systems



System operators who need a general understanding of this feature

1.3 Change History The change history provides information on the changes in different document versions. There are two types of changes, which are defined as follows: 

Feature change Feature change refers to the change in the Handover feature of a specific product version.



Editorial change Editorial change refers to the change in wording or the addition of the information that was not described in the earlier version.

Document Issues The document issue is as follows: 

01 (2010-06-30)



Draft (2010-03-30)

01 (2010-06-30) This is the first release of GBSS12.0. Compared with issue Draft (2010-03-30) of GBSS12.0, issue 01 (2010-06-30) of GBSS12.0 incorporates the changes described in the following table. Change Type Change Description

Parameter Change

Feature change

The added parameters are listed as follows:

Enhanced Load Handover is added.

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

LOADHOAD



LAYHOLOADTH



LOADHOPBGTMARGIN



LOADHOUSRRATIO



LOADSTATYPE


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1 Introduction

Change Type Change Description Editorial change

Parameter Change

Parameters are presented in the None form of Parameter ID instead of Parameter Name.

Draft (2010-03-30) This is the draft release of GBSS12.0.

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2 Overview

2 Overview The GSM network comprises multiple cells with continuous coverage. The handover technique is introduced into the GSM system to enable the users who are in motion to continue with the current call without interruption, thus optimizing the network performance. During a handover, the MS and BTS in service measure the conditions of uplink and downlink radio links respectively, record the measurement results into measurement reports (MRs), and then send the MRs to the BSC. The BSC determines whether to trigger a handover based on the MRs and the actual conditions of the radio network. Huawei handover algorithms (handover algorithm I and handover algorithm II) involve measurement and MR reporting, MR processing, handover decision, and handover execution. Huawei handover algorithms apply to the handovers on TCHs as well as the handovers on SDCCHs.

You can determine the handover algorithm used in a cell through HOCTRLSWITCH. Figure 2-1 shows the procedure for performing Huawei handover algorithms (including handover algorithm I and handover algorithm II). Figure 2-1 Procedure for performing Huawei handover algorithms

Start MS in connection state MS performs measurement and MR reporting BSS performs MR processing Handover decision based on handover algorithm Handover execution End

Handover Decision Based on Handover Algorithm I Figure 2-2 shows the procedure of handover decision based on handover algorithm I.

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2 Overview

Figure 2-2 Procedure of handover decision based on handover algorithm I

Start No downlink measurement report handover decision MS starts minimum interval protection Whether minimum interval protection of consecutive handovers times out?

No

Yes Handover preprocessing Handover penalty Basic queuing Network characteristics adjustment Forced handover

Quick handover

No

Whether minimum interval protection of handover times out? Yes Other handover decisions Determines target cell according to 2G/3G priority selection conditions and corresponding thresholds Starts minimum interval protection of consecutive handovers End

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2 Overview

In handover algorithm I, five types of handover decisions are defined: 

Quick handover (including quick Power Budget(PBGT) handover and frequency offset handover). Good and stable services can be provided when the voice quality deteriorates during the fast movement of an MS. Quick handover is mainly applicable in the railway scenario.



Emergency handover. Emergency handover can ensure the call continuity when the radio condition severely deteriorates. Theoretically, the emergency handover has a bigger deviation than other handovers in terms of the selection of the target cell. In a normal cell, frequent emergency handovers should be avoided.



Enhanced dual-band network handover. In an enhanced dual-band network, the resources in the overlaid DCS1800 cell and underlaid GSM900 cell can be shared during the assignment and handover procedures. That is, the calls in the high-traffic GSM900 cell can be handed over to the low-traffic DCS1800 cell to balance traffic.



Load handover. Load handover enables the system load to be balanced among multiple cells so that the system performance can be ensured.



Normal handover. Normal handover ensures good services when an MS is moving.

Figure 2-3 shows the handovers provided in Figure 2-2 and their priorities in handover algorithm I.

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2 Overview

Figure 2-3 Handover decisions based on handover algorithm I

Emergency handover TA handover Interference handover Rapid level drop handover BQ handover Starts protection timer after emergency handover is triggered. Enhanced dual-band network handover Load handover Normal handover Edge handover Fast-moving micro cell handover Inter-layer handover PBGT handover Concentric cell handover AMR handover 3G better cell handover TIGHT BCCH handover

Handover Decision Based on Handover Algorithm II Figure 2-4 shows the procedure of handover decision based on handover algorithm II.

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2 Overview

Figure 2-4 Procedure of handover decision based on handover algorithm II Start No downlink measurement report handover decision MS starts minimum interval protection

Whether minimum interval protection of consecutive handovers times out?

No

Handover preprocessing

Yes

Basic queuing Network characteristics adjustment (some factors) Forced handover Handover penalty Quick handover (emergency handover)

No

Whether minimum interval protection of consecutive handovers times out? Yes Emergency handover (not including quick handover) Load handover decision Network characteristics adjustment (all factors) Other handover decisions Performs comprehensive decision of handover result and determines candidate neighbor cell Starts minimum interval protection of consecutive handovers End

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2 Overview

In handover algorithm II, three types of handover decisions are defined, as shown in Figure 2-5. Figure 2-5 Handover decisions based on handover algorithm II

Emergency handover Quick handover

Intra-cell handover Interference handover

TA handover

Concentric cell handover

BQ handover

AMR handover

Edge handover

Handover between a fullrate TCH and a half-rate TCH

Inter-cell handover Fast-moving micro cell handover Enhanced dual-band network handover Better cell handover 3G better cell handover

TIGHT BCCH handover

Handover Execution (GBFD-117101 BTS power lift for handover) BTS power lift for handover function determines whether the BTS of the serving cell transmits signals at the maximum power during a handover. The BSC maximizes the transmit power of the BTS before sending a handover command to the MS. The BSC does not adjust the BTS power during the handover to ensure the success of the handover.

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3 Technical Description

3 Technical Description 3.1 Measurement Report Processing This section describes the feature GBFD-110801 Processing of Measurement Report and GBFD-110802 Pre-processing of Measurement Report. Measurement report processing involves measurement report interpolation and filtering.

NE Selection for Measurement Report Processing The processing can be performed either on the BSC side or on the BTS side. 

If BTSMESRPTPREPROC is set to No, then the processing is performed on the BSC side.



If BTSMESRPTPREPROC is set to Yes, then the processing is performed on the BTS side. By setting the parameters PRIMMESPPT, BSMSPWRLEV, and MRPREPROCFREQ, you can specify the contents of the MRs to be provided and the period during which the MRs are provided. This decreases the signaling traffic on the Abis interface and the traffic volume processed by the BSC.

Data Selection for Measurement Report The MR can be classified into enhanced MR and normal MR. The parameter MEASURETYPE determines the type to be used. In the MR, the TCH measurement of the serving cell is classified into FULL SET and SUB SET.

Measurement Report Interpolation The neighboring cell indexes are found on the basis of the BCCH frequencies and BSICs provided by the MS. Then, the uplink and downlink measurement results are obtained from the measurement reports. 

If measurement reports are issued continuously, they are directly added to the measurement report list.



If measurement reports are not issued continuously and the number of lost measurement reports is smaller than the value of MRMISSCOUNT, the system performs operations as follows: − For

the serving cell, the handover algorithm I performs the linear interpolation for the MRs. The lowest values are applied to the interpolation of MRs by the handover algorithm II according to the protocols; that is, level 0 (-110 dBm) and quality 7 are applied in the interpolation.

− For

the neighboring cell, the lowest value is applied to the lost level value according to the protocols; that is, level 0 (-110 dBm) is applied in the interpolation.

If no MR is reported because the RX level in the neighboring cell is too low, level 0 (-110 dBm) is applied in the interpolation. 

If measurement reports are not issued continuously and the number of lost measurement reports is greater than the value of MRMISSCOUNT, the previous measurement reports are discarded. When new measurement reports are issued, calculation is done again.

Measurement Report Filtering Filtering is performed on measurement reports obtained continuously from the measurement report list. Averaging is performed on uplink/downlink RX level, uplink/downlink RX quality, Timing Advance(TA), Radio Quality Indication(RQI), BTS power, 2G neighboring cell level, and the Common Pilot Channel (CPICH), Received Signal Code Power(RSCP), and Ec/No of neighboring 3G cell. The averaging

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minimizes the effect on the result of handover decision due to sudden changes in the measurement values. Power control compensation needs to be performed for the downlink RX level of the serving cell by the handover algorithm II. If you compare the RX level of the serving cell after the power control with that of all BCCH TRXs of the neighboring cell, there is no mapping between them. In situations where the cells overlap severely, the handover is easily triggered, thus causing the ping-pong handover. After the power control compensation is performed, the RX level of the serving cell can reflect the coverage condition of the BCCH TRX of the serving cell. The power control compensation of the serving cell is performed after the interpolation processing and before the filtering processing. In general, the compensation of power control is calculated by adding the downlink RX level of the serving cell and twice the current downlink transmit POWL of the BTS. The number of consecutive measurement reports required for filtering is determined by the measurement object and channel type. See Table 3-1 for details. Table 3-1 Parameters related to the number of measurement reports Measurement Object

Channel Type Parameter

Receive level of the SDCCH serving cell TCH

Filter Length for SDCCH Level

Quality of the serving cell

SDCCH

Filter Length for SDCCH Qual.

TCH

Filter Length for TCH Qual

TA of the serving cell

TCH

Filter Length for TA

SDCCH

TA filter length for SDCCH level

Receive level of the BCCH neighboring cell SDCCH

Filter Length for TCH Level

Filter Length for Ncell RX_LEV NCell filter length for SDCCH level

Power of the BTS in TCH the serving cell

Filter Length for TCH Level

RQI

Filter Length for TCH Qual

TCH

If consecutive measurement reports are insufficient, the filtering fails. The handover decision is not performed.

3.2 Handover Preprocessing Handover Penalty According to the neighboring cell information in the measurement report and the parameters, the system performs handover preprocessing and adjusts the priorities of the neighboring cells. The handover penalty is performed after successful fast-moving micro cell handover, TA handover, BQ handover, fast-moving micro cell handover, OL subcell to UL subcell handover within an enhanced concentric cell, and after the handover failures. In handover algorithm II, in addition to the situations mentioned above, the handover penalty is also performed after successful or failed load handover and interference handover.

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In handover decision procedure of handover algorithm II, the handover penalty is performed after the network characteristics adjustment and before the emergency handover decision. 

After the quick handover, TA handover, Bad Quality(BQ) handover, or load handover (in handover algorithm II) is successfully performed, the penalty level is subtracted from the actual RX level of the original cell during the penalty period. Table 3-2 lists the parameters related to handover penalty.

Table 3-2 Parameters related to handover penalty Handover

Parameter

Quick handover

Quick Handover Punish Time Quick Handover Punish Value

TA Handover

Penalty Level after TA HO Penalty Time after TA HO

BQ Handover

Penalty Level after BQ HO Penalty Time after BQ HO

Load handover (handover algorithm II)

Penalty Time on Load HO Penalty Value on Load HO



After the fast-moving micro cell handover is successfully performed, penalty is performed on all the neighboring cells of the micro cell. Related parameters are SDPUNVAL and SPEEDPUNISHT.



If an MS fails to initiate an intra-cell AMR TCHF to TCHH handover, it cannot initiate another intra-cell AMR TCHF to TCHH handover within TIMEAMRFHPUNISH.



In handover algorithm II, after the interference handover is initiated, this handover is not allowed to be initiated again within INTERFEREHOPENTIME regardless of whether the handover is successful or not.



After the OL subcell to UL subcell handover within an enhanced concentric cell is successful, the handover from UL subcell to OL subcell is not allowed within UTOOHOPENTIME.



After the OL cell to UL cell handover in the enhanced dual-band network is successful, the handover from UL cell to OL cell is not allowed within HOPENALTYTIME.



After the handover fails, different penalties are performed on the target cell based on the causes: − If

the handover to a neighboring 2G or 3G cell fails, the actual RX level of the target cell is subtracted by FAILSIGSTRPUNISH for neighboring cell ranking during the penalty.

Based on the handover failure cause, the penalty time could be UMPENALTYTIMER, RSCPENALTYTIMER, or PENALTYTIMER. − If

the OL subcell to UL subcell handover within a concentric cell fails, the handover from OL subcell to UL subcell is not allowed within TIMEOTOUFAILPUN.

− If

the UL subcell to OL subcell handover within a concentric cell fails, the handover from UL subcell to OL subcell is not allowed within TIMEUTOOFAILPUN.

Basic Ranking Basic ranking is performed after handover penalty to generate a candidate cell list in descending order taking the following information into account: RX levels of the serving cell and neighboring cells carried in the MRs, hysteresis, usage of TCHs in the neighboring cells, and so on.

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

In the case of non-directed retry, if an MS in an external BSC cell occupies an SDCCH and INRBSCSDHOEN is set to No, then this cell should be removed from the candidate cell list. In other words, the handover to this external BSC cell is prohibited.



If a neighboring 2G cell and the serving cell are controlled by the same BSC and the TCH usage of the neighboring cell is 100%, then the neighboring cell should be removed from the candidate cell list; that is, the handover to this neighboring cell is prohibited.



If the downlink RX level of a neighboring 2G cell is lower than the sum of HOCDCMINDWPWR and MINOFFSET, then the neighboring cell should be removed from the candidate cell list; that is, the handover to this neighboring cell is prohibited.



If the uplink RX level of a neighboring 2G cell is lower than the sum of HOCDCMINUPPWR and MINOFFSET, then the neighboring cell should be removed from the candidate cell list; that is, the handover to this neighboring cell is prohibited.



If a neighboring 3G cell is an FDD cell, the cell is processed according to FDDREP: − If

FDDREP is set to Ec/N0, and the Ec/N0 of a neighboring cell is lower than MINECNOTHRES, the neighboring cell should be removed from the candidate cell list; that is, the handover to this neighboring cell is prohibited.

− If

FDDREP is set to RSCP, and the RSCP of a neighboring cell is lower than MINRSCPTHRES, the neighboring cell should be removed from the candidate cell list; that is, the handover to this neighboring cell is prohibited.



If a neighboring 3G cell is a TDD cell and the RSCP after penalty is lower than the MINRSCPTHRES, the neighboring cell should be removed from the candidate cell list; that is, the handover to this neighboring cell is prohibited.



Calculate the difference between the downlink RX level of the neighboring cells and the downlink RX level of the serving cell. Based on the difference, rank the neighboring cells in descending order.

Network Characteristics Adjustment Network characteristics adjustment is a process in which the position of each cell in the candidate cell list is determined based on the related network information. Network characteristics adjustment provides the final candidate cell list for handover decision. After the network characteristics adjustment, the final candidate cell list (including neighboring cells and serving cell) is generated. The candidate cells are ranked in descending order by priority. Then, the handover decision procedure starts. In handover algorithm II, the emergency handover decision is made after the network characteristics adjustment. After the emergency handover decision, LOADHOPENVALUE is subtracted from the level of the original cell within LOADHOPENTIME if the load handover is successful. The level of the target cell changes after the penalty of load handover; then, the network characteristics needs to be readjusted. In handover algorithm I, all related factors are adjusted in network characteristics adjustment phase; in handover algorithm II, some of the factors are adjusted before the emergency handover decision procedure is initiated.

Forced Handover A forced handover does not require a handover decision. A forced handover is triggered in the following scenarios: 

If no TCH is available in the serving cell which the MS attempts to access and DIRECTRYEN is set to Yes, the BSC triggers a directed retry procedure.

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When a BTS is under maintenance, the MSs served by the BTS should be handed over to the cells controlled by a functional BTS. This ensures that no call drop occurs during the BTS maintenance.

Directed Retry (GBFD-110607 Directed Retry) When the MS initiates a call, after the BSC receives an ASSIGN REQ message from the MSC, the BSC determines an assignment mode based on the load of the serving cell. Assignment mode is categorized into normal assignment procedure, mode modification procedure, and directed retry procedure. The commands issued by the BSC vary according to the procedure. 

For a normal assignment procedure, the BSC activates a channel and issues a channel assignment command.



For a mode modification procedure, the BSC issues a mode modification command.



For a directed retry procedure, the BSC issues a handover command.

If the serving cell is so overloaded that new calls cannot be admitted or admitting new calls will affect ongoing services, the BSC triggers a directed retry procedure. By using the directed retry, the MS is handed over to the target cell and part of the traffic in the serving cell is distributed to the target cell. This avoids traffic congestion in the serving cell. Figure 3-1 shows the procedure for a directed retry decision.

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Figure 3-1 Procedure for a directed retry decision

When ASSLOADJUDGEEN is set to OFF, the BSC triggers a directed retry procedure after completing basic ranking if the load of the serving cell exceeds 100%.

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As shown in Figure 3-1, directed retry is categorized into enhanced dual-band network directed retry and normal directed retry. 

Enhanced Dual-Band Network Directed Retry In an enhanced dual-band network, two cells form a group and the MS camps on one of the two cells. After the directed retry is triggered, the MS is handed over to the other cell. For details on the conditions of triggering an enhanced dual-band network directed retry, see sections 3.3.7 "Enhanced Dual-Band Network Handover" and 3.4.6 "Enhanced Dual-Band Network Handover."



Target Cell Selection in a Normal Directed Retry Procedure The target cell must have the highest priority in the candidate cell list after handover preprocessing. In addition, the target cell must meet the following conditions: − The

serving cell does not function as a target cell.

− Load

of the candidate neighboring cells ≤ DTLOADTHRED

− In

handover algorithm II, serving cell level < receive level of neighboring cells < serving cell level + DRHOLEVRANGE.

− In

handover algorithm I, receive level of neighboring cells ≥ MINPWRLEVDIRTRY.

3.3 Handover Decision Based on Handover Algorithm I This section describes the feature GBFD-110601 HUAWEI I Handover. According to the emergency condition of an MS in the network, the handover decision based on handover algorithm I is made in the following order: quick handover, emergency handover, enhanced dual-band network handover, load handover, and normal handover. Handover decision based on handover algorithm I involves the following procedures: 

Determining whether the serving cell meets the triggering conditions



Selecting corresponding candidate cells

In handover algorithm I, HOOPTSEL specifies whether a neighboring 2G cell or a neighboring 3G cell is preferred. 

When HOOPTSEL is set to Preference for 2G Cell: A neighboring 2G cell is preferred. If the candidate cell list contains suitable neighboring 3G cells but no suitable neighboring 2G cells, a neighboring 3G cell is selected.



When HOOPTSEL is set to Preference for 3G Cell: A neighboring 3G cell is preferred. If the candidate cell list contains suitable neighboring 2G cells but no suitable neighboring 3G cells, a neighboring 2G cell is selected.



When HOOPTSEL is set to Preference for 2G Cell: If the RX level of a candidate 2G cell is lower than or equal to HOPRETH2G, a neighboring 3G cell is preferred.

If the triggering conditions of emergency handover are met and there is at least one candidate cell, then the emergency handover timer NEWURGHOMININTV is started. Another emergency handover decision can be performed only when NEWURGHOMININTV times out.

3.3.1 Quick Handover This section describes the features GBFD-510103 Chain Cell Handover and GBFD-510102 Fast Move Handover.

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Quick handover aims to increase the handover success rate of an MS moving at a high speed and to ensure the call continuity and low call drop rate. Quick handover applies to the scenario where an MS moves fast along an urban backbone road, a selected route, or a high-speed railroad.

Quick Handover Types Quick handover consists of frequency offset handover and fast move handover. 

Frequency offset handover Whether the MS is moving away from the serving cell is determined based on the frequency offset information provided by an MS moving at a high speed. Frequency offset handover decision is made according to the uplink/downlink RX level of the serving cell and the path loss of neighboring cells.



Fast move handover Fast move handover decision is made according to the path loss of neighboring cells.

For quick handover, the handover response speed is enhanced by: 

Accurately calculating the moving speed of the MS



Derestricting the interval between handover decisions



Reducing the number of measurement reports for the handover decision



Introducing the alpha filtering

Quick Handover Preparation The preparation for quick handover involves the following aspects: 

Frequency offset is decoded from the measurement report. Frequency offset of the MS is obtained from the uplink measurement report that the BTS sends to the BSC.



Alpha filtering is performed on the measurement report.

Triggering Conditions During handover decision, it is first determined whether the triggering conditions of frequency offset handover are met. When the BTS cannot send the frequency offset information or the reported frequency offset information is invalid, fast move handover is triggered, provided that other conditions of frequency offset handover are met. If QUICKHOEN is set to Yes, the triggering conditions of quick handover are as follows: 

The MS is moving away from the serving cell (the frequency offset in the measurement result is a negative value) and the moving speed of the MS is greater than MOVESPEEDTHRES.



The filtered uplink level of the serving cell is lower than HOUPTRIGE.



The compensated downlink level of the serving cell is lower than HODOWNTRIGE.



The path loss of configured chain neighboring cells is lower than the specified threshold of the path loss of the serving cell. In other words, PBGT(n) is greater than or equal to 0.

The triggering conditions of quick handover are as follows: 



If the last three conditions are met simultaneously, the decision is made as follows: − If

the first condition is met, a frequency offset handover is performed.

− If

the first condition is not met, a fast move handover is performed.

If all the last three conditions are not met, quick handover is not triggered.

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Target Cell Selection The target cell must be a chain neighboring cell of the serving cell. The target cell can be obtained through the setting of ISCHAINNCELL. If HODIRFORECASTEN is set to Yes, a neighboring cell in the moving direction of the MS is selected preferentially. To forecast the moving direction of the MS, the direction of a chain neighboring cell (A or B) compared with the serving cell is specified by CHAINNCELLTYPE. If the number of times that the MS is handed over to neighboring cells in the same direction (B for example) is greater than or equal to HODIRLASTTIME when the handover time reaches HODIRSTATIME, then the MS is inferred to be moving towards the B direction. Subsequently, the MS is preferentially handed over to the neighboring cell whose CHAINNCELLTYPE is B.

Limitations The limitations on quick handover are as follows: 

The serving cell cannot be selected as the target cell.



The candidate cells for quick handover must be chain neighboring cells of the serving cell.



After a quick handover is successful, the penalty is performed on the original cell during the penalty time to prevent an immediate handover back to the original cell. The penalty time and penalty value are specified by TIMEPUNISH and HOPUNISHVALUE respectively.

3.3.2 TA Handover TA handover is a type of emergency handover. The TA handover decision is made according to the TA value reported by the MS. The TA value of a normal cell ranges from 0 to 63 and that of an extended cell ranges from 0 to 229. The TA can be stepped up or down in steps of 553.5 m. The TA value of 63 corresponds to a distance of 35 km.

Triggering Conditions TA handover is triggered when the following conditions are met: 

TAHOEN is set to Yes.



Filtered TA value in the measurement report provided by the MS is greater than or equal to TALIMIT.

The TA handover can be triggered only when the preceding two conditions are met simultaneously. From the perspective of the triggering conditions of TA handover, TA can be regarded as a limitation to the size of a cell.

Target Cell Selection The target cell should have the highest priority in the candidate cell list after handover preprocessing. In addition, the target cell should meet the following conditions: 




If TALIMIT of a co-site neighboring cell is lower than or equal to the TALIMIT of the serving cell, a handover to the neighboring cell is prohibited.

If the triggering conditions of TA handover are met but the candidate 2G cells are not suitable, the following operations are performed: 

If a neighboring 3G cell is available, if INTERRATOUTBSCHOEN is set to Yes, and if the MS supports the 2G/3G inter-RAT handover, the 2G/3G inter-RAT handover is performed.

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If no neighboring 3G cell is available, if INTERRATOUTBSCHOEN is set to No, or if the MS does not support the 2G/3G inter-RAT handover, the decision on whether to initiate another type of emergency handover is made.

Limitations After the TA handover is successful, the penalty is performed on the original cell. During TIMETAPUNISH, SSTAPUNISH is subtracted from the level of the original cell to prevent an immediate handover back to the original cell.

3.3.3 BQ Handover BQ handover is a type of emergency handover in which the system makes the decision based on the uplink/downlink RX quality on the Um interface. The RX quality is measured in bit error rate (BER). The BSC measures the quality of a radio link based on the quality class in the measurement report. The probable cause of an increase in BER is that the signal power is too low or the channel interference increases.

Triggering Conditions If BQHOEN is set to Yes, the triggering conditions of BQ handover are as follows: 

The uplink RX quality is greater than or equal to the uplink RX quality threshold of the serving cell.



The downlink RX quality is greater than or equal to the downlink RX quality threshold of the serving cell.

The BQ handover is triggered when either of the preceding conditions is met. The parameters for specifying the uplink and downlink RX quality thresholds are as follows: 

For non-AMR calls, the parameter for specifying the uplink RX quality threshold is ULQUALIMIT and the parameter for specifying the downlink RX quality threshold is DLQUALIMIT.



For AMR FR calls, the parameter for specifying the uplink RX quality threshold is ULQUALIMITAMRFR and the parameter for specifying the downlink RX quality threshold is DLQUALIMITAMRFR.



For AMR HR calls, the parameter for specifying the uplink RX quality threshold is ULQUALIMITAMRHR and the parameter for specifying the downlink RX quality threshold is DLQUALIMITAMRHR.


If the target cell is a neighboring cell, the RX level of the target cell must meet the following condition: Filtered downlink RX level of the target cell > Filtered downlink RX level of the serving cell after compensation + (INTERCELLHYST of the serving cell configured for the neighboring cell - 64) (BQMARGIN — 64)

In handover algorithm I, if there is only one cell in the candidate cell list and the cell is a neighboring cell, then the preceding condition need not be met. 

In handover algorithm I, if there is no neighboring cell, INTRACELLHOEN is set to Yes, and the serving cell is not in the intra-cell handover penalty state, then the MS is handed over to the serving cell. A channel with different frequency band, different frequency, different TRX, or different timeslot is preferred (priority: different frequency band > different frequency > different TRX > different timeslot).

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If the triggering conditions of BQ handover are met but the candidate 2G cells are not suitable, the following operations are performed: 





Limitations After the BQ handover is successful, the penalty is performed on the original cell. During TIMEBQPUNISH, SSBQPUNISH is subtracted from the level of the original cell to prevent an immediate handover back to the original cell.

3.3.4 Rapid Level Drop Handover Rapid level drop handover is a type of emergency handover. In edge handover and PBGT handover, the mean value filtering and P/N decision methods are not responsive to short-period rapid level drop. Therefore, to solve the rapid level drop problem, the finite impact response filtering can be performed on the original RX level. This filtering method is responsive to the rapid level drop based on the drop slope of the original RX level.

Triggering Conditions If ULEDGETHRES is set to Yes, the triggering conditions of rapid level drop handover are as follows: 

Filtered uplink level < ULEDGETHRES



A1 x C(nt) + A2 x C(nt - t) + A3 x C(nt - 2t) + … + A8 x C(nt - 7t) < B Here, A1 indicates FLTPARAA1, A2 indicates FLTPARAA2, A3 indicates FLTPARAA3, A4 indicates FLTPARAA4, A5 indicates FLTPARAA5, A6 indicates FLTPARAA6, A7 indicates FLTPARAA7, and A8 indicates FLTPARAA8. B indicates FLTPARAB.


The target cell has a higher priority than the serving cell.




If the triggering conditions of rapid level drop handover are met but the candidate 2G cells are not suitable, the following operations are performed: 

If a neighboring 3G cell is available, INTERRATOUTBSCHOEN is set to Yes, and the MS supports the 2G/3G inter-RAT handover, the 2G/3G inter-RAT handover is performed.



If no neighboring 3G cell is available, INTERRATOUTBSCHOEN is set to No, or the MS does not support the 2G/3G inter-RAT handover, the decision on whether to initiate another type of emergency handover is made.

3.3.5 Interference Handover In handover algorithm I, interference handover is a type of emergency handover.

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Interference handover helps protect the interfered calls and reduce the network interference. It is applicable to scenarios with interference. In handover algorithm I, the difference between interference handover and BQ handover is that in BQ handover the bad signal quality resulting from both coverage and interference is checked. In interference handover, the bad signal quality resulting from coverage is not checked.

Triggering Conditions If INTERFHOEN is set to Yes, the triggering conditions of interference handover are as follows: 

The filtered value of uplink RX quality is greater than or equal to the specified RX quality threshold at the current uplink RX level.



The filtered value of downlink RX quality is greater than or equal to the specified RX quality threshold at the current downlink RX level.

The interference handover is triggered if either of the previous conditions is met. The parameters for specifying the uplink and downlink RX quality thresholds are as follows: 

For non-AMR FR calls, the parameter for specifying the RX quality threshold is RXQUALn, where 1 ≤ n ≤ 12.



For AMR FR calls, the parameters for specifying the RX quality threshold are RXQUALn (1 ≤ n ≤ 12) and RXLEVOFF. − If

n = 1, the RX quality threshold is RXQUAL1.

− If

2 ≤ n ≤ 12, the RX quality threshold is RXQUALn + RXLEVOFF.

Target Cell Selection In handover algorithm I, the target cell should have the highest priority in the candidate cell list. In addition, the target cell should meet the following conditions: 

If INTRACELLHOEN is set to Yes and the intra-cell handover penalty timer expires, the serving cell can be selected as the target cell.

When a number of consecutive intra-cell handovers occur, BANTIME is triggered and the intra-cell handover is prohibited in the corresponding period. 

If the filtered level of a neighboring cell after handover penalty ≥ HOTHRES of the neighboring cell + INTELEVHOHYST - 64, this neighboring cell can serve as the target cell.

If the triggering conditions of interference handover are met but the candidate 2G cells are not suitable, the following operations need to be performed: 

If a neighboring 3G cell is available, INTERRATOUTBSCHOEN is set to Yes, and the MS supports the 2G/3G inter-RAT handover, the 2G/3G inter-RAT handover is performed.



If no neighboring 3G cell is available, INTERRATOUTBSCHOEN is set to No, or the MS does not support the 2G/3G inter-RAT handover, the decision on whether to initiate another type of emergency handover is made.

3.3.6 Handover Due to No Downlink Measurement Report Handover due to no downlink measurement report is performed on the basis of the uplink quality. The purpose is to ensure the call continuity and minimize the possibility of call drops. Handover due to no downlink measurement report is generally caused by adverse radio environment on the uplink. In this case, the requirements of the filtering algorithm cannot be met, so other handover decisions cannot be performed.

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Triggering Conditions In handover algorithm I, the triggering conditions of handover due to no downlink measurement report are as follows: 

NODLMRHOEN is set to Yes.



There is no downlink information in the measurement report of the call.



The filtered value of uplink quality is greater than or equal to NODLMRHOQUALLIMIT.



The number of lost downlink MRs is smaller than NODLMRHOALLOWLIMIT.



For TCH, the number of saved MRs with uplink quality value is greater than DATAQUAFLTLEN; for SDCCH, the number of saved MRs with uplink quality value is greater than QLENSI.

When all the previous conditions are met, the handover due to no downlink measurement report is triggered.

Target Cell Selection In handover algorithm I, the conditions for selecting the target cell are as follows: 

The ranked neighboring cells recorded in the last complete measurement report are saved as candidate cells.



Preferably a neighboring cell is selected as the target cell.



If no neighboring cell is available, the serving cell is selected as the target cell.

3.3.7 Enhanced Dual-Band Network Handover Enhanced dual-band network handover is performed based on the traffic volume of the overlaid and underlaid cells and based on the receive level. Enhanced dual-band network handover is classified into the following types: 

Handover due to high load in the underlaid cell



Handover due to low load in the underlaid cell



Handover due to MS movement to the border of the overlaid cell

Triggering Conditions of Handover Due to High Load in the Underlaid Cell The triggering conditions of the handover due to high load in the underlaid cell are as follows: 

The two cells are in the enhanced dual-band network and OUTLOADHOENABLE is set to Yes.



The MS supports the frequency band on which the overlaid cell operates.



The handover due to high load in the underlaid cell is performed only on TCHs.



The load in the underlaid cell is higher than or equal to OUTGENOVERLDTHRED.



The load in the overlaid cell is lower than INNSERIOVERLDTHRED.



The system traffic volume is lower than or equal to EDBSYSFLOWLEV.



The current call is within the handover margin, and the INTOINNREXLEVTHRED plus the handover margin is greater than or equal to the receive level, which is also greater than or equal to the INTOINNREXLEVTHRED.

When all the preceding conditions are met, the handover due to high load in the underlaid cell is triggered. If the load of the underlaid subcell in the cell is higher than or equal to OUTSERIOVERLDTHRED, then the handover margin is adjusted in a period of OUTLOADHOPERIOD subtracted by

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OUTLOADHOMODPERI. The step length for handover margin adjustment is specified by OUTLOADHOSTEP.

Triggering Conditions of Handover Due to Low Load in the Underlaid Cell The triggering conditions of the handover due to low load in the underlaid cell are as follows: 

The load in the underlaid cell is lower than OUTLOWLOADTHRED.






The current call is within the handover margin and the receive level is greater than or equal to OUTINNREXLEVTHRED.

When all the preceding conditions are met, the handover due to low load in the underlaid cell is triggered. If the load of the underlaid subcell is lower than OUTLOWLOADTHRED for a specified period, then the handover margin is adjusted in a period of INNLOADHOPERI. The step length for handover margin adjustment is specified by INNLOADHOSTEP.

Triggering Conditions of Handover Due to MS Movement to the Border of the Overlaid Cell The triggering conditions of the handover due to MS movement to the border of the overlaid cell are as follows: 

SS(s) < Thdouter



SS(u) - SS(n) < ATCB_THRD - ATCB_HYST Here, − SS(s):

specifies the filtering compensated downlink RX level in the serving cell.

− Thdouter:

specifies OUTINNREXLEVTHRED.

− SS(u):

specifies the downlink level (power compensation is performed on the downlink level based on the measurement) of the underlaid cell where the call is originated. If the SS(u) value cannot be obtained, you can infer that the decision of enhanced dual-band network handover is not performed and the decision condition is met by default.

− SS(n):

The best neighboring cell is the one whose measured BCCH level is the highest among neighboring cells. SS(n) is the signal level of the best neighboring cell that operates on the same frequency band, locates at the same layer, and has the same priority as the underlaid cell but is not co-sited with the underlaid cell. If such a neighboring cell is not available, the value of SS(n) is -110 dBm.

− ATCB_THRD:

specifies ATCBTHRED.

− ATCB_HYST:

specifies ATCBHYST.

Handover due to MS movement to the border of the overlaid cell is triggered if either of the preceding conditions is met.

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

In the adapter distance to cell border(ATCB) handover algorithm, the border between the overlaid and underlaid cells is determined according to the signal strength of the serving cell and that of neighboring cells. If SS(s) = SS(n), the system considers that the MS is located at the border of the underlaid cell. If SS(s) - SS(n) > ATCB_THRD, the system considers that the MS is located in the coverage area of the overlaid cell. The coverage area of the overlaid cell is determined according to different networking and coverage conditions of the existing network. In addition, the overlaid cell of the serving cells and the overlaid cell of the neighboring cells will not overlap regardless of the distance between BTSs.



The handover margin specifies the range of signal level. In the case of overlaid/underlaid load handover on the enhanced dual-band network, the MSs whose downlink levels are within the handover margin are handed over level by level.

Target Cell Selection The requirements for target cell selection in the enhanced dual-band network are as follows: 

For the handover due to high load in the underlaid cell, the MS must be handed over to the overlaid cell.



For the handover due to low load in the underlaid cell, the MS must be handed over to the underlaid cell.



For the handover due to MS movement to the border of the overlaid cell, the MS is handed over to the neighboring cell that ranks first among neighboring cells. The MS should not be handed over to the cell that ranks after the serving cell. Generally, the target cell is the underlaid cell. The target cell can also be another neighboring cell.

Limitations The limitations on the handover due to high load in the underlaid cell are as follows: 

If the cell where the call is located is on an enhanced dual-band network, CELLINEXTP is set to Extra(Extra).



The OUTLOADHOENABLE parameter should be set.



The maximum range of the handover margin is from 63 to INTOINNREXLEVTHRED. The MS with the highest receive level is handed over first.

The limitations on the handover due to low load in the underlaid cell are as follows: 

If the cell where the call is located is on the enhanced dual-band network, CELLINEXTP is set to Inner(Inner).



The INNLOADHOEN parameter should be set.



The maximum range of the handover margin is from 63 to OUTINNREXLEVTHRED. The MS with the lowest receive level is handed over first.

The limitations on the handover due to MS movement to the border of the overlaid cell are as follows: 


Impact of the Enhanced Dual-Band Network Handover on the Existing Algorithm The impact of the enhanced dual-band network handover on the existing algorithm is as follows: 

On the enhanced dual-band network, the MS should not be handed over to a cell in the same underlaid/overlaid cell group when the load handovers between the overlaid cell and the underlaid cell (specified by OUTLOADHOENABLE and INNLOADHOEN) are allowed. This is to prevent a load handover of a normal cell from colliding with a load handover between the overlaid cell and the underlaid cell on the network.

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The PBGT handover algorithm may cause inter-cell handover; thus, the MS should not be handed over to the cell in the same group in the case of PBGT handover between cells on the enhanced dual-band network.

3.3.8 Load Handover In the network, some cells carry heavy load whereas the overlapping upper-layer cells and the neighboring cells may carry light load. To balance the load of these cells, the load handover is required. In a load handover procedure, some load in heavy-load cells is switched to light-load cells. Meanwhile, the load in neighboring cells is not switched to heavy-load cells. Load handover can be performed between cells at different layers. Figure 3-2 shows the details. For details about the inter-RAT load handover, see the 2G/3G Interoperability Parameter Description feature.

Figure 3-2 Load handover between cells A cell with a heavy load A cell with a light load

A cell with a light load A cell with a heavy load

A cell with a light load

A cell with a heavy load A cell with a light load

To perform load sharing, increase DLEDGETHRES so that the load at the border of a cell is switched to a neighboring cell with light load. Whether a cell carries heavy load or light load is determined by the traffic volume in the cell, that is whether the traffic volume (generally TCH usage) in the cell exceeds the preset threshold. 

If the traffic volume in a cell is greater than TRIGTHRES, you can infer that the load in this cell is heavy. The load handover algorithm needs to be enabled.



If the traffic volume in a cell is lower than LoadAccThres, you can infer that the load in this cell is light and the cell can receive load from the heavy-load cells.

Load handover may lead to many handovers. Therefore, the load of the system CPU should be considered before load handover is performed. In other words, the system traffic volume should be taken into account. In addition, to prevent too many MSs from being handed over at a time, load handover is performed step by step. In other words, the edge handover threshold is increased on the basis of LOADHOSTEP (CLS_Ramp) and LOADHOPERIOD (CLS_Period). When the increase in the edge handover threshold equals LOADOFFSET (CLS_Offset), the edge handover threshold is not increased any more. See Figure 3-3 for details.

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Figure 3-3 Load handover Load handover band

Cell A

CONF_HO_RXLEV+CLS_Offset

Border of normal handover

Cell B

CONF_HO_RXLEV CONF_HO_RXLEV+CLS_Ramp

Triggering Conditions If LoadHoEn is set to Yes, the triggering conditions of load handover are as follows: 

The CPU usage of the system is less than or equal to SYSFLOWLEV.



The current load of the serving cell is greater than or equal to TRIGTHRES.

Target Cell Selection The conditions for selecting the target cell are as follows: 

Filtered RX level after handover penalty ≥ HOTHRES + INTELEVHOHYST - 64






If the target cell and the serving cell are in the same BSC, a load handover is performed when the current load of the target cell is lower than LoadAccThres.



If the target cell and the serving cell are not in the same BSC, a load handover is performed when the load of the target cell is lower than LoadAccThres and OutBscLoadHoEn is set to Yes.

Examples The system assigns MSs to different load handover margins based on the downlink RX level. The load handover algorithm is used to hand over the MSs out of a cell step by step. 1. The MSs in load handover margin 1 are handed over to the neighboring cells. Load handover margin 1 specifies the area where the downlink level ranges from DLEDGETHRES to the sum of DLEDGETHRES and LOADHOSTEP. 2. After a LOADHOPERIOD elapses, the MSs in load handover margin 2 are handed over to the neighboring cells. The load handover margin 2 specifies the area where the downlink level ranges from DLEDGETHRES to the sum of DLEDGETHRES and (2 x LOADHOSTEP). 3. The load handover stops when the traffic volume in the cell is less than or equal to TRIGTHRES. The load handover is performed step by step to prevent call drops caused by a sudden increase in CPU load or the congestion in the target cell.

3.3.9 Enhanced Load Handover Like the load handover, the enhanced load handover is used to balance load of cells in a network. Unlike the load handover, the enhanced load handover considers the handover quality and the load in the target cell before the handover is performed. In this way, the possibility of low level and congestion due to heavy load in the target cell Issue 01 (2010-06-30)


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after the handover is minimized. The enhanced load handover is applicable to the scenario where multiple base stations are located at the same place.

Triggering Conditions of Enhanced Load Handover If LOADHOAD is set to YES, the triggering conditions of an enhanced load handover are as follows: −

The CPU usage of the current system is lower than or equal to SYSFLOWLEV.

−

The load of the serving cell is higher than TRIGTHRES.

Here, the load of the serving cell is expressed in the percentage of the channels that are occupied. If the built-in PCU is used, the calculation method of the cell load depends on the setting of LOADSTATYPE. The setting of the parameter determines whether the dynamic PDCHs that can be preempted are considered as occupied channels. −

When LOADSTATYPE is set to 0, the dynamic PDCHs that can be preempted are not considered in the cell load.

−

When LOADSTATYPE is set to 1, the dynamic PDCHs that can be preempted are considered as occupied TCHs in the cell load.

−

When LOADSTATYPE is set to 2, the dynamic PDCHs that can be preempted are considered as idle TCHs in the cell load.

The number of the dynamic PDCHs that can be preempted depends on the number of dynamic PDCHs and DYNCHNPREEMPTLEV. The number of dynamic PDCHs is the total number of channels whose CHTYPE is set to FULLTCH. If the external PCU is used, the number of the dynamic PDCHs that can be preempted is always zero. The setting of LOADSTATYPE is thus irrelevant to calculation of the cell load.

Target Cell Selection When a candidate cell satisfying the following conditions is found and not a single MS within the range specified by LOADHOUSRRATIO is handed over to the target cell, further search of the target cell is stopped and current traffic is handed over to the candidate cell. The detailed conditions for selecting the target cell are as follows: −

The value of LOADHOPBGTMARGIN is not 0 and the path loss in the serving cell minus that in the target cell is larger than LOADHOPBGTMARGIN.

−

The load of the target cell is lower than LoadAccThres.

−

The receive level of the target cell is higher than HOTHRES of the target cell plus INTELEVHOHYST of the handover from the serving cell to the target cell.

Of all the MSs that are within the range specified by LOADHOUSRRATIO and meet the preceding conditions, only one MS can initiate the handover at a time. This regulation prevents too many MSs from being handed over to the target cell at one time and thus avoids congestion in the target cell.

3.3.10 Edge Handover Edge handover is performed on the basis of receive level.

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To trigger an edge handover, the receive level of the target cell should be at least one hysteresis value (specified by INTERCELLHYST - 64) greater than the receive level of the serving cell.

Triggering Conditions If FRINGEHOEN is set to Yes, the triggering conditions of edge handover are as follows: 



Either of the following conditions is met. − The

filtered downlink RX level of the serving cell after compensation is lower than DLEDGETHRES.

− The

filtered uplink RX level of the serving cell after compensation is lower than ULEDGETHRES.

RX level of the neighboring cell > RX level of the serving cell + INTERCELLHYST — 64

An edge handover is triggered when the P/N criterion is met, that is, when the previous conditions are met for EDGELAST1 within EDGESTAT1. Figure 3-4 shows the edge handover. Figure 3-4 Edge handover Cell 1

Cell 2

-97 dBm

-85 dBm

Target Cell Selection The target cell should have the highest priority among the candidate cells. In addition, it should meet the following conditions: 




After cells are ranked, the target cell must have a higher priority than the serving cell.

A cell becomes the target cell if the previous conditions are met for EDGEADJLASTTIME within EDGEADJSTATTIME. If the triggering conditions of edge handover are met but the candidate 2G cells are not suitable, the following operations are performed: 




If no neighboring 3G cell is available, if INTERRATOUTBSCHOEN is set to No, or if the MS does not support the 2G/3G inter-RAT handover, the decision on whether to initiate another type of handover is made.

3.3.11 Fast-Moving Micro Cell Handover Fast-moving micro cell handover is performed from a micro cell to a macro cell according to the relative speed of an MS so that the number of handovers can be minimized. Fast-moving micro cell handover applies to the following scenarios:

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

If an MS is moving fast in a micro cell, it is handed over to a macro cell.



To prevent an MS that is moving fast in a macro cell from entering a micro cell, time penalty is performed on the micro cell so that the fast-moving MS camps on the macro cell.

Figure 3-5 shows the fast-moving micro cell handover. Figure 3-5 Fast-moving micro cell handover

Umbrella cell Micro cell

Triggering Conditions If QCKMVHOEN is set to Yes, the handover decision procedure of fast-moving micro cell handover is as follows: 1. When the triggering conditions of edge handover or PBGT handover are met, the fast-moving micro cell handover decision is started. 2. When the period during which the MS camps on the serving cell is shorter than QCKTIMETH, the number of cells through which the fast-moving MS passes is incremented by one. The cell counted by the system must locate at a layer lower than layer 4. In other words, it must be a non-Umbrella cell.

3. When the number of cells that the MS passes in fast movement reaches QCKSTATCNT, the fast-moving micro cell handover is triggered if the number of cells that the MS passes in fast movement counted by the system is greater than or equal to QCKTRUECNT.

Target Cell Selection In handover algorithm I, the target cell should have the highest priority among the candidate cells. In addition, the target cell should meet the following conditions: 

The target cell must be at layer 4, that is, Umbrella cell.



Filtered RX level of the target cell ≥ HOTHRES + INTELEVHOHYST - 64

Limitations After the fast-moving micro cell handover is successful, the penalty is performed on all the neighboring micro cells. During SPEEDPUNISHT, SDPUNVAL is subtracted from the RX level of every neighboring micro cell.

Cell Layer and Cell Priority With Huawei multiband handover algorithm, a proper traffic volume distribution can be realized among multiple frequency bands.

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Huawei multiband handover algorithm divides cells into four layers, with 16 priorities at each layer. The LAYER parameter specifies at which layer a cell is located. This algorithm is applicable to complex networking scenarios. Figure 3-6 shows the cell layers. Figure 3-6 Cell layers GSM900 Layer 4

Umbrella Cell GSM900

GSM900

GSM900

Macro Cell

Layer 3 DCS1800

DCS1800

DCS1800

Micro Cell

Layer 2 GSM900

DCS1800

GSM900

GSM900

GSM900

DCS1800

DCS1800

DCS1800

Pico Cell

Layer 1

In Huawei multiband handover algorithm, a GSM network covering a certain area is divided into four layers, which are: 

Layer 4: Umbrella cell. The umbrella cells are generally GSM900 cells having the wide coverage feature. It also implements fast MS connection.



Layer 3: Macro cell. The macro cells are generally GSM900 cells, which are commonly used in current GSM system and serve majority of subscribers.



Layer 2: Micro cell. The micro cells are generally DCS1800 cells having the small coverage feature. They enable capacity expansion.



Layer 1: Pico cell. The Pico cells are generally DCS1800 cells, which are used in hot spots and blind spots.

The cell at the lower layer has a higher priority. PRIOR controls handover between cells at the same layer. Each layer has 16 priorities, numbered 1-16 respectively. A high value indicates a low priority. If the cells at the same layer have different priorities, a cell with a lower priority value has a higher priority. PRIOR along with CELLLAYER determines the priority of a cell. The priority affects the sequence of neighboring cells for handover.

3.3.12 Inter-Layer Handover Inter-layer handover is a type of normal handover. It is used to enable the micro cells at low layers (the priority is high) to absorb traffic volume. To balance the traffic volume flexibly and to meet the requirements of different network topologies, the GSM network is divided into several layers. See 3.3.10 Fast-Moving Micro Cell Handover for details.

Triggering Conditions If LEVHOEN is set to Yes, the triggering conditions of inter-layer handover are as follows:

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

The layer at which the target cell is located has a higher priority than the layer at which the serving cell is located.



The load of the serving cell is higher than LAYHOLOADTH.



Filtered downlink RX level of the target cell ≥ HOTHRES + INTELEVHOHYST - 64




The inter-layer handover is triggered when the P/N criterion is met, that is, the previous conditions are met for LEVLAST within LEVSTAT.

Target Cell Selection The requirements for target cell selection are as follows: 

The triggering conditions are met.






The target cell has the highest priority in the candidate cell list.

3.3.13 PBGT Handover This section describes the feature GBFD-510102 Fast Move Handover. PBGT handover is a type of normal handover.

Triggering Conditions If PBGTHOEN is set to Yes, the triggering conditions of PBGT handover are as follows: 

The target cell and the serving cell are at the same layer and have the same priority.



The following condition is met for PBGTLAST within PBGTSTAT: (MIN (MS_TXPWR_MAX, P) – RXLEV_DL – PWR_DIFF) – (MIN (MS_TXPWR_MAX (n), P) – RXLEV_NCELL (n) ) > PBGT_HO_MARGIN Here, − RXLEV_DL:

indicates the filtered downlink RX level of the serving cell.

− MS_TXPWR_MAX: − MS_TXPWR_MAX

indicates the maximum allowed transmit power of an MS in the serving cell. (n): indicates the maximum allowed transmit power of an MS in neighboring cell

n. − RxLev_NCELL

(n): indicates the downlink receive level in neighboring cell n.

− PWR_DIFF:

indicates the difference between the maximum downlink transmit power in the serving cell due to power control and the actual downlink transmit power in the serving cell.

− P:

indicates the maximum transmit power of an MS.

− PBGT_HO_MARGIN:

indicates the PBGTMARGIN of the serving cell configured for neighboring

cells minus 64. The PBGT handover can be triggered only when all the previous conditions are met.

Target Cell Selection The target cell should meet the following conditions: 

The target cell and the serving cell are at the same layer and have the same priority.







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3.3.14 AMR Handover This section describes the feature GBFD-115504 AMR FR/HR Dynamic Adjustment. The AMR handover in handover I algorithm consists of the AMR TCHF-TCHH handover and AMR TCHH-TCHF handover algorithm. The AMR TCHF-TCHH handover is conducted based on cell load and RQI, whereas the AMR TCHH-TCHF handover is conducted based on RQI. The conversion formula between RQI and C/I is RQI = 2 x C/I.

Triggering Conditions of AMR TCHF-TCHH Handover The triggering conditions of AMR TCHF-TCHH handover are as follows: 

INTRACELLFHHOEN is set to Yes.



The target call is an AMR call.



The half-rate function must be enabled in the cell where the call is initiated.



The full-rate speech version 3 and half-rate speech version 3 must be supported by the cell where the call is initiated.



The type of channel specified by the MSC during a call can be changed during a handover.



For AMR FR calls, when the parameter AMRTCHHPRIORALLOW is set to ON(On), TCHF-to-TCHH handover is triggered only when the cell load is greater than the value of the parameter AMRTCHHPRIORLOAD and the proportion of AMR HR users is smaller than the value of the parameter ALLOWAMRHALFRATEUSERPERC.



For AMR FR calls, when the parameter AMRTCHHPRIORALLOW is set to OFF(Off), TCHF-to-TCHH handover is triggered only the proportion of AMR HR users is smaller than the value of the parameter ALLOWAMRHALFRATEUSERPERC.



The call occupies the full-rate TCH. The RQI/2 is greater than INHOF2HTH and the cell load is greater than AMRTCHHPRIORLOAD.

For an AMR FR call, the AMR TCHF-TCHH handover can be performed if the preceding conditions are met for INFHHOLAST within INFHHOSTAT.

Triggering Conditions of AMR TCHH-TCHF Handover The triggering conditions of AMR TCHH-TCHF handover are as follows: 

INTRACELLFHHOEN is set to Yes.



The target call is an AMR call.



The half-rate function must be enabled in the cell where the call is initiated.



The full-rate speech version 3 and half-rate speech version 3 must be supported by the cell where the call is initiated.



The type of channel specified by the MSC during a call can be changed during a handover.



The call occupies the half-rate TCH. The RQI/2 is smaller than INHOH2FTH, and the proportion of half-rate TCHs in the cell is smaller than ALLOWAMRHALFRATEUSERPERC.

For an AMR HR call, the AMR TCHH-TCHF handover can be performed if the preceding conditions are met for INFHHOLAST within INFHHOSTAT.

Target Cell Selection The AMR handover is an intra-cell handover. Therefore, only the serving cell can be selected as the target cell.

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3.3.15 SDCCH Handover This section describes the feature GBFD-110608 SDCCH Handover. SDCCH handover is a process in which the MS is handed over from an SDCCH to another SDCCH in an immediate assignment. SDCCH handover helps improve the access success rate of the MSs on the edge of the network, thus improving the network QoS. The principle of SDCCH handover is the same as that of TCH handover. Regarding procedure, an SDCCH handover involves measurement and MR reporting, MR processing, handover decision, and handover execution. Whether an SDCCH handover can be performed is controlled by the SIGCHANHOEN parameter. If an inter-BSC SDCCH handover is required, both SIGCHANHOEN and INRBSCSDHOEN should be set to YES(Yes). The handover decision algorithm for SDCCH handover is different from that for TCH handover in the following ways: 

The algorithms for the following handovers support SDCCH handover: quick handover, TA handover, BQ handover, rapid level drop handover, interference handover, handover due to no downlink measurement report, edge handover, and fast-moving micro cell handover



The algorithms for the following handovers do not support SDCCH handover: enhanced dual-band network handover, load handover, inter-layer handover, PBGT handover, AMR handover, better 3G cell handover, concentric cell handover, and tight BCCH handover

3.3.16 Other Handovers Other handovers here refer to better 3G cell handover and tight BCCH handover.

Better 3G Cell Handover See 2G/3G Interoperability Feature Parameter Description.

Tight BCCH Handover See BCCH Dense Frequency Multiplexing Feature Parameter Description.

3.4 Handover Decision Based on Handover Algorithm II This section describes the feature GBFD-510501 HUAWEI II Handover. Handover decision based on handover algorithm II is made in the following order: forced handover, emergency handover, intra-cell handover, and inter-cell handover. Handover decision based on handover algorithm II involves the following procedures: 

Determining whether the serving cell meets the triggering conditions



Selecting corresponding candidate cell list for each handover type



Performing the comprehensive decision and determining the candidate neighboring cells

The procedure for performing comprehensive decision based on handover results and determining the candidate neighboring cells is as follows: 1. The BSC selects a handover type with the highest priority from all the handovers that can be performed on each neighboring cell. The handover priority is as follows: Issue 01 (2010-06-30)


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− Forced

handover, emergency handover, and interference handover have a high priority. Figure 3-7 shows the details.

Figure 3-7 Handovers with high priority

Handover decision with high priority Forced handover Directed retry Quick handover TA handover Interference BQ handover Edge handover

Quick handover is classified into frequency offset handover and fast move handover. Frequency offset handover has a higher priority than fast move handover. − Intra-cell

handover (excluding interference handover) and inter-cell handover have a normal priority. Figure 3-8 shows the details.

AMR handover has the same priority as TCHF-TCHH handover.

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Figure 3-8 Handovers with normal priority

Handover decision with normal priority Fast-moving micro cell handover Enhanced dual-band network handover Load handover Better cell handover Concentric cell handover AMR handover TIGHT BCCH handover

2. The BSC ranks the candidate cells according to the network characteristics adjustment algorithm and then generates the final candidate cell list. Every neighboring cell in the candidate cell list has its own handover decision. Neighboring 2G cells and neighboring 3G cells are ranked separately. 3. In handover algorithm II, HOOPTSEL specifies whether a neighboring 2G or a neighboring 3G cell is preferred. − When

HOOPTSEL is set to Preference for 2G Cell:

A neighboring 2G cell is preferred. If the candidate cell list contains suitable neighboring 3G cells but no suitable neighboring 2G cells, a neighboring 3G cell is selected. − When

HOOPTSEL is set to Preference for 3G Cell:

A neighboring 3G cell is preferred. If the candidate cell list contains suitable neighboring 2G cells but no suitable neighboring 3G cells, a neighboring 2G cell is selected. − When

HOOPTSEL is set to Preference for 2G Cell By Threshold:

If the RX level of a candidate 2G cell is lower than or equal to HOPRETH2G, a neighboring 3G cell is preferred. When a neighboring 3G cell is preferred among the candidate cells, the priority of 3G better cell handover is the lowest.

If the triggering conditions of emergency handover are met and there is at least one candidate cell, then the emergency handover timer NEWURGHOMININTV is started. Another emergency handover decision can be performed only when NEWURGHOMININTV times out.

3.4.1 Quick Handover This section describes the features GBFD-510103 Chain Cell Handover and GBFD-510102 Fast Move Handover.

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Quick handover aims to increase the handover success rate of an MS moving at a high speed and to ensure the call continuity and low call drop rate. Quick handover applies to the scenario where an MS moves fast along an urban backbone road, a selected route, or a high-speed railroad.

Quick Handover Types Quick handover consists of frequency offset handover and fast move handover. 

Frequency offset handover Whether the MS is moving away from the serving cell is determined based on the frequency offset information provided by an MS moving at a high speed. Frequency offset handover decision is made according to the uplink/downlink RX level of the serving cell and the path loss of neighboring cells.



Fast move handover Fast move handover decision is made according to the path loss of neighboring cells.

For quick handover, the handover response speed is enhanced by: 

Accurately calculating the moving speed of the MS



Derestricting the interval between handover decisions



Reducing the number of measurement reports for the handover decision



Introducing the alpha filtering

Quick Handover Preparation The preparation for quick handover involves the following aspects: 

Frequency offset is decoded from the measurement report. Frequency offset of the MS is obtained from the uplink measurement report that the BTS sends to the BSC.



Alpha filtering is performed on the measurement report.

Triggering Conditions During handover decision, it is first determined whether the triggering conditions of frequency offset handover are met. When the BTS cannot send the frequency offset information or the reported frequency offset information is invalid, fast move handover is triggered, provided that other conditions of frequency offset handover are met. If QUICKHOEN is set to Yes, the triggering conditions of quick handover are as follows: 

The MS is moving away from the serving cell (the frequency offset in the measurement result is a negative value) and the moving speed of the MS is greater than MOVESPEEDTHRES.



The filtered uplink level of the serving cell is lower than HOUPTRIGE.



The compensated downlink level of the serving cell is lower than HODOWNTRIGE.



The path loss of configured chain neighboring cells is lower than the specified threshold of the path loss of the serving cell. In other words, PBGT(n) is greater than or equal to 0.

The triggering conditions of quick handover are as follows: 



If the last three conditions are met simultaneously, the decision is made as follows: − If

the first condition is met, a frequency offset handover is performed.

− If

the first condition is not met, a fast move handover is performed.

If all the last three conditions are not met, quick handover is not triggered.

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Target Cell Selection The target cell must be a chain neighboring cell of the serving cell. The target cell can be obtained through the setting of ISCHAINNCELL. If HODIRFORECASTEN is set to Yes, a neighboring cell in the moving direction of the MS is selected preferentially. To forecast the moving direction of the MS, the direction of a chain neighboring cell (A or B) compared with the serving cell is specified by CHAINNCELLTYPE. If the number of times that the MS is handed over to neighboring cells in the same direction (B for example) is greater than or equal to HODIRLASTTIME when the handover time reaches HODIRSTATIME, then the MS is inferred to be moving towards the B direction. Subsequently, the MS is preferentially handed over to the neighboring cell whose CHAINNCELLTYPE is B.

Limitations The limitations on quick handover are as follows: 




The candidate cells for quick handover must be chain neighboring cells of the serving cell.



After a quick handover is successful, the penalty is performed on the original cell during the penalty time to prevent an immediate handover back to the original cell. The penalty time and penalty value are specified by TIMEPUNISH and HOPUNISHVALUE respectively.

3.4.2 TA Handover TA handover is a type of emergency handover. The TA handover decision is made according to the TA value reported by the MS. The TA value of a normal cell ranges from 0 to 63 and that of an extended cell ranges from 0 to 229. The TA can be stepped up or down in steps of 553.5 m. The TA value of 63 corresponds to a distance of 35 km.

Triggering Conditions TA handover is triggered when the following conditions are met: 

TAHOEN is set to Yes.



Filtered TA value in the measurement report provided by the MS is greater than or equal to TALIMIT.

The TA handover can be triggered only when the preceding two conditions are met simultaneously. From the perspective of the triggering conditions of TA handover, TA can be regarded as a limitation to the size of a cell.

Target Cell Selection The target cell should have the highest priority in the candidate cell list after handover preprocessing. In addition, the target cell should meet the following limitations: 




If TALIMIT of a co-site neighboring cell is lower than or equal to the TALIMIT of the serving cell, a handover to the neighboring cell is prohibited.



In handover algorithm II, a cell becomes the target cell for TA handover if the previous conditions are met for TALASTTIME within TASTATTIME.

If the triggering conditions of TA handover are met but the candidate 2G cells are not suitable, the following operations are performed:

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





Limitations After the TA handover is successful, the penalty is performed on the original cell. During TIMETAPUNISH, SSTAPUNISH is subtracted from the level of the original cell to prevent an immediate handover back to the original cell.

3.4.3 BQ Handover BQ handover is a type of emergency handover in which the system makes the decision based on the uplink/downlink RX quality on the Um interface. RX quality is represented by bit error rate (BER). The BSC measures the quality of a radio link based on the quality class in the measurement report. The probable cause of an increase in BER is that the signal power is too low or the channel interference increases.

Triggering Conditions If BQHOEN is set to Yes, the triggering conditions of BQ handover are as follows: 

The uplink RX quality is greater than or equal to the uplink RX quality threshold of the serving cell.



The downlink RX quality is greater than or equal to the downlink RX quality threshold of the serving cell.

The BQ handover is triggered when either of the preceding conditions is met. The parameters for specifying the uplink and downlink RX quality thresholds are as follows: 

For non-AMR calls, the parameter for specifying the uplink RX quality threshold is ULQUALIMIT and the parameter for specifying the downlink RX quality threshold is DLQUALIMIT.



For AMR FR calls, the parameter for specifying the uplink RX quality threshold is ULQUALIMITAMRFR and the parameter for specifying the downlink RX quality threshold is DLQUALIMITAMRFR.



For AMR HR calls, the parameter for specifying the uplink RX quality threshold is ULQUALIMITAMRHR and the parameter for specifying the downlink RX quality threshold is DLQUALIMITAMRHR.


In handover algorithm II, the serving cell cannot be selected as the target cell.



The RX level of target cell must meet the following conditions: − The

serving cell and the target cell work in the same frequency band.

Filtered downlink RX level of the target cell > Filtered downlink RX level of the serving cell after compensation + (INTERCELLHYST of the serving cell configured for the neighboring cell - 64) (BQMARGIN - 64) − The

serving cell works in GSM900 and the target cell works in DCS1800.

Filtered downlink RX level of the target cell ≥ HOTHRES + (LEVHOHYST - 64).

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serving cell works in DCS1800 and the target cell works in GSM900.

There is no constraint on the target cell in this condition. 

In handover algorithm II, a cell becomes the target cell for BQ handover if the previous conditions are met for BQLASTTIME within BQSTATTIME.

If the triggering conditions of BQ handover are met but the candidate 2G cells are not suitable, the following operations are performed: 





Limitations After the BQ handover is successful, the penalty is performed on the original cell. During TIMEBQPUNISH, SSBQPUNISH is subtracted from the level of the original cell to prevent an immediate handover back to the original cell.

3.4.4 Interference Handover Interference handover is a type of intra-cell handover in handover algorithm II. Interference handover helps protect the interfered calls and reduce the network interference. It is applicable to scenarios with interference. In handover algorithm II, the BQ handover is a type of emergency handover and the interference handover is a type of intra-cell handover.

Triggering Conditions If INTRACELLHOEN is set to Yes and INTERFHOEN is set to Yes, the triggering conditions of interference handover are as follows: 

The filtered value of uplink RX quality is greater than or equal to the specified RX quality threshold at the current uplink RX level.



The filtered value of downlink RX quality is greater than or equal to the specified RX quality threshold at the current downlink RX level.

In handover algorithm II, the interference handover is triggered when the previous conditions are met for INTERFERELASTTIME within INTERFERESTATTIME. The parameters for specifying the uplink and downlink RX quality thresholds are as follows: 

For non-AMR FR calls, the parameter for specifying the RX quality threshold is RXQUALn, where 1 ≤ n ≤ 12.



For AMR FR calls, the parameters for specifying the RX quality threshold are RXQUALn (1 ≤ n ≤ 12) and RXLEVOFF. − If

n = 1, the RX quality threshold is RXQUAL1.

− If

2 ≤ n ≤ 12, the RX quality threshold is RXQUALn + RXLEVOFF.

Target Cell Selection In handover algorithm II, only the serving cell can be selected as the target cell.

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Limitations In handover algorithm II, if an interference handover is initiated, it cannot be initiated again within INTERFEREHOPENTIME regardless of whether the handover is successful.

3.4.5 Handover Due to No Downlink Measurement Report Handover due to no downlink measurement report is performed on the basis of the uplink quality. The purpose is to ensure the call continuity and minimize the possibility of call drops. Handover due to no downlink measurement report is generally caused by adverse radio environment on the uplink. In this case, the requirements of the filtering algorithm cannot be met, so other handover decisions cannot be performed.

Triggering Conditions In handover algorithm II, the triggering conditions of handover due to no downlink measurement report are as follows: 

NODLMRHOEN is set to Yes.



There is no downlink information in the measurement report of the call.



The number of lost downlink MRs is smaller than NODLMRHOALLOWLIMIT.



For TCH, the number of saved MRs with uplink quality value is greater than DATAQUAFLTLEN; for SDCCH, the number of saved MRs with uplink quality value is greater than QLENSI.



The filtered value of uplink RX quality is greater than or equal to ULQUALIMIT. − For AMR

FR calls, the corresponding parameter is ULQUALIMITAMRFR.

− For AMR

HR calls, the corresponding parameter is ULQUALIMITAMRHR.

When all the previous conditions are met, the handover due to no downlink measurement report is triggered.

Target Cell Selection In handover algorithm II, the conditions for selecting the target cell are as follows: 

The ranked neighboring cells recorded in the last complete measurement report are saved as candidate cells.



Only a neighboring cell can serve as the target cell.



RX level in neighboring cell > Filtered RX level in serving cell + (INTERCELLHYST - 64) (BQMARGIN - 64)



A neighboring cell serves as the target cell if the previous conditions are met for ULBQLASTTIME within ULBQSTATTIME.

3.4.6 Enhanced Dual-Band Network Handover Enhanced dual-band network handover is performed based on the traffic volume of the overlaid and underlaid cells and based on the receive level. Enhanced dual-band network handover is classified into the following types: 

Handover due to high load in the underlaid cell



Handover due to low load in the underlaid cell



Handover due to MS movement to the border of the overlaid cell

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Triggering Conditions of Handover Due to High Load in the Underlaid Cell The triggering conditions of the handover due to high load in the underlaid cell are as follows: 

The two cells are in the enhanced dual-band network and OUTLOADHOENABLE is set to Yes.



The MS supports the frequency band on which the overlaid cell operates.



The handover due to high load in the underlaid cell is performed only on TCHs.



The load in the underlaid cell is higher than or equal to OUTGENOVERLDTHRED.



The load in the overlaid cell is lower than INNSERIOVERLDTHRED.






The current call is within the handover margin, and the INTOINNREXLEVTHRED plus the handover margin is greater than or equal to the receive level, which is also greater than or equal to the INTOINNREXLEVTHRED.

When all the preceding conditions are met, the handover due to high load in the underlaid cell is triggered. If the load of the underlaid subcell is higher than or equal to OUTSERIOVERLDTHRED, then the handover margin is adjusted in a period of OUTLOADHOPERIOD subtracted by OUTLOADHOMODPERI. The step length for handover margin adjustment is specified by OUTLOADHOSTEP.

Triggering Conditions of Handover Due to Low Load in the Underlaid Cell The triggering conditions of the handover due to low load in the underlaid cell are as follows: 

The load in the underlaid cell is lower than OUTLOWLOADTHRED.






The current call is within the handover margin and the receive level is greater than or equal to OUTINNREXLEVTHRED.

When all the preceding conditions are met, the handover due to low load in the underlaid cell is triggered. If the load of the underlaid subcell is lower than OUTLOWLOADTHRED for a specified period, then the handover margin is adjusted in a period of INNLOADHOPERI. The step length for handover margin adjustment is specified by INNLOADHOSTEP.

Triggering Conditions of Handover Due To MS Movement in the Overlaid Subcell The triggering conditions of the handover due to MS movement in the overlaid subcell are described as follows: 

SS(s) < Thdouter



SS(u) - SS(n) < ATCB_THRD - ATCB_HYST Here, − SS(s):

specifies the filtering compensated downlink RX level in the serving cell.

− Thdouter:

specifies OUTINNREXLEVTHRED.

− SS(u):

specifies the downlink level (power compensation is performed on the downlink level based on the measurement) of the underlaid subcell where the call is originated. If the SS(u) value cannot be obtained, you can infer that the decision of enhanced dual-band network handover is not performed and the decision condition is met by default.

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− SS(n):

The best neighboring cell is the one whose measured BCCH level is the highest among neighboring cells. SS(n) is the level value of such an optimum neighboring cell that is on the same frequency band, layer, and level with the underlaid subcell but is not co-sited with the underlaid subcell. If such a neighboring cell is not available, the value of SS(n) is -110 dBm.

− ATCB_THRD:

specifies ATCBTHRED.

− ATCB_HYST:

specifies ATCBHYST.

Handover due to MS movement in the overlaid subcell is triggered if either of the preceding conditions is met. 

For the ATCB handover algorithm, the boundaries of the overlaid and underlaid subcells are determined according to the relative value between the signal strength of serving cell and that of neighboring cell. When SS(s) is equal to SS(n), the system considers that it is the boundary point of the underlaid subcell. When the value of SS(s) subtracted by SS(n) is greater than ATCB_THRD, it is the coverage area of the overlaid subcell. The coverage area of the overlaid subcell is determined according to different networking and coverage conditions of the existing network. In addition, the overlaid subcell of serving cell and the overlaid subcell of neighboring cells will not overlap regardless of the distance between BTSs.



The handover margin specifies the range of signal level. In the case of overlaid/underlaid load handover on the enhanced dual-band network, the MSs whose downlink levels are within the handover margin are handed over level by level.

Target Cell Selection The requirements for target cell selection in the enhanced dual-band network are as follows: 

For the handover due to high load in the underlaid cell, the MS must be handed over to the overlaid cell.



For the handover due to low load in the underlaid cell, the MS must be handed over to the underlaid cell.



For the handover due to MS movement in the overlaid subcell, the MS must be handed over to the underlaid cell.

Limitations The limitations on the handover due to high load in the underlaid cell are as follows: 

If the cell where the call is located is on an enhanced dual-band network, CELLINEXTP is set to Extra(Extra).



The OUTLOADHOENABLE parameter should be set.



The maximum range of the handover margin is from 63 to INTOINNREXLEVTHRED. The MS with the highest receive level is handed over first.

The limitations on the handover due to low load in the underlaid cell are as follows: 




The INNLOADHOEN parameter should be set.



The maximum range of the handover margin is from 63 to OUTINNREXLEVTHRED. The MS with the lowest receive level is handed over first.

The limitations on the handover due to MS movement in the overlaid subcell are described as follows: 

The cell where the call is located is on the enhanced dual-band network. CELLINEXTP is set to Inner(Inner).

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Impact of the Enhanced Dual-Band Network Handover on the Existing Algorithm The impact of the enhanced dual-band network handover on the existing algorithm is as follows: On the enhanced dual-band network, the MS should not be handed over to a cell in the same underlaid/overlaid cell group when the load handovers between the overlaid cell and the underlaid cell (specified by OUTLOADHOENABLE and INNLOADHOEN) are allowed. This is to prevent a load handover of a normal cell from colliding with a load handover between the overlaid cell and the underlaid cell on the network.

3.4.7 Load Handover In handover algorithm II, load handover is not decided independently. In handover algorithm II, the load handover decision is made in network adjustment phase. The selection of target cell should be processed by the better cell handover. That is, the load handover is triggered when the triggering conditions of load handover and better cell handover are met simultaneously. See 3.3.8 Load Handover for the triggering conditions of load handover. See 3.4.10 Better Cell Handover for the triggering conditions of better cell handover. The ranges of load handover margins are defined as follows: Load handover margin 1 specifies the area where the downlink level ranges from INTERCELLHYST minus LOADHOSTEP to INTERCELLHYST. Load handover margin 2 specifies the area where the downlink level ranges from INTERCELLHYST minus LOADHOSTEP x 2 to INTERCELLHYST. Load handover margin 1 specifies the area where the downlink level ranges from DLEDGETHRES to the sum of DLEDGETHRES and LOADHOSTEP.

3.4.8 Edge Handover Edge handover is performed on the basis of receive level. To trigger an edge handover, the receive level of the target cell should be at least one hysteresis value (specified by INTERCELLHYST - 64) greater than the receive level of the serving cell.

Triggering Conditions If FRINGEHOEN is set to Yes, the triggering conditions of edge handover are as follows: 



Either of the following conditions is met. − The

filtered downlink RX level of the serving cell after compensation is lower than DLEDGETHRES.

− The

filtered uplink RX level of the serving cell after compensation is lower than ULEDGETHRES.

RX level of the neighboring cell > RX level of the serving cell + INTERCELLHYST - 64

An edge handover is triggered when the P/N criterion is met, that is, when the previous conditions are met for EDGELAST within EDGESTAT. Figure 3-9 shows the edge handover.

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Figure 3-9 Edge handover Cell 1

Cell 2

-97 dBm

-85 dBm

Target Cell Selection The target cell should have the highest priority among the candidate cells. In addition, it should meet the following conditions: 





A cell becomes the target cell if the previous conditions are met for EDGEADJLASTTIME within EDGEADJSTATTIME. If the triggering conditions of edge handover are met but the candidate 2G cells are not suitable, the following operations are performed: 




If no neighboring 3G cell is available, if INTERRATOUTBSCHOEN is set to No, or if the MS does not support the 2G/3G inter-RAT handover, the decision on whether to initiate another type of handover is made.

3.4.9 Fast-Moving Micro Cell Handover Fast-moving micro cell handover is performed from a micro cell to a macro cell according to the relative speed of an MS so that the number of handovers can be minimized. Fast-moving micro cell handover applies to the following scenarios: 

If an MS is moving fast in a micro cell, it is handed over to a macro cell.



To prevent an MS that is moving fast in a macro cell from entering a micro cell, time penalty is performed on the micro cell so that the fast-moving MS camps on the macro cell.

Figure 3-10 shows the fast-moving micro cell handover.

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Figure 3-10 Fast-moving micro cell handover

Umbrella cell Micro cell

Triggering Conditions If QCKMVHOEN is set to Yes, the handover decision procedure of fast-moving micro cell handover is as follows: 1. When the triggering conditions of edge handover or PBGT handover are met, the fast-moving micro cell handover decision is started. 2. When the period during which the MS camps on the serving cell is shorter than QCKTIMETH, the number of cells through which the fast-moving MS passes is incremented by one. The cells counted by the system must locate at a layer lower than layer 4. In other words, they must be non-Umbrella cells.

3. When the number of cells that the MS passes in fast movement reaches QCKSTATCNT, the fast-moving micro cell handover is triggered if the number of cells that the MS passes in fast movement counted by the system is greater than or equal to QCKTRUECNT.

Target Cell Selection In handover algorithm II, the target cell should have the highest priority among the candidate cells. In addition, the target cell should meet the following conditions: 

The target cell must be at layer 4, that is, Umbrella cell.



Filtered RX level of the target cell ≥ HOTHRES + INTELEVHOHYST - 64



A neighboring cell serves as the target cell if the previous conditions are met for HCSLASTTIME within HCSSTATTIME.

Limitations After the fast-moving micro cell handover is successful, the penalty is performed on all the neighboring micro cells. During SPEEDPUNISHT, SDPUNVAL is subtracted from the RX level of every neighboring micro cell.

Cell Layer and Cell Priority Through Huawei multiband handover algorithm, a proper traffic volume distribution can be realized among multiple frequency bands.

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Huawei multiband handover algorithm divides cells into four layers, with 16 priorities at each layer. The LAYER parameter specifies at which layer a cell is located. This algorithm is applicable to complex networking scenarios. Figure 3-11 shows the cell layers. Figure 3-11 Cell layers GSM900 Layer 4

Umbrella Cell GSM900

GSM900

GSM900

Macro Cell

Layer 3 DCS1800

DCS1800

DCS1800

Micro Cell

Layer 2 GSM900

DCS1800

GSM900

GSM900

GSM900

DCS1800

DCS1800

DCS1800

Pico Cell

Layer 1

In Huawei multiband handover algorithm, a GSM network covering a certain area is divided into four layers, which are: 

Layer 4: Umbrella cell. The umbrella cells are generally GSM900 cells having the wide coverage feature. It also implements fast MS connection.



Layer 3: Macro cell. The macro cells are generally GSM900 cells, which are commonly used in current GSM system and serve majority of subscribers.



Layer 2: Micro cell. The micro cells are generally DCS1800 cells having the small coverage feature. They enable capacity expansion.



Layer 1: Pico cell. The Pico cells are generally DCS1800 cells, which are used in hot spots and blind spots.

The cell at the lower layer has a higher priority. PRIOR controls handover between cells at the same layer. Each layer has 16 priorities, numbered 1-16 respectively. A high value indicates a low priority. If the cells at the same layer have different priorities, a cell with a lower priority value has a higher priority. PRIOR along with CELLLAYER determines the priority of a cell. The priority affects the sequence of neighboring cells for handover.

3.4.10 Better Cell Handover Better cell handover is an optimization of inter-layer handover and PBGT handover in handover algorithm I. Better cell handover is specific to handover algorithm II.

Triggering Conditions If BETTERCELLHOEN is set to Yes, the triggering conditions of better cell handover are as follows:

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

If PATHLOSSHOEN is set to Yes, path loss is taken into consideration during the sorting of the serving cell and target cells. If PATHLOSSHOEN is set to No, path loss is not taken into consideration during the sorting of the serving cell and target cells.



If the serving cell is in the candidate cell list, then the priorities of the target cells must be higher than the priority of the serving cell after the sorting.



If the serving cell is not in the candidate cell list, then the target cells must meet the following conditions: − LoadHoEn

is set to NO, or LoadHoEn is set to YES but the load in the serving cell is lower than TRIGTHRES.

− If

the serving cell and the target cells are at the same layer and have the same priority, the following conditions must be met: SS_DL(N) - SS_DL(S) > H - 64 SS_DL(N) indicates the filtered BCCH receive level of a target cell. SS_DL(S) indicates the compensated receive level on the downlink TCH after filtration. H indicates INTERCELLHYST of the serving cell over the neighboring cell. Negative handover is a type of better cell handover. When INTERCELLHYST is set to a value smaller than 64, the value of H – 64 is negative. In this case, even if the downlink receive level in a candidate cell is lower than the downlink receive level in the serving cell, a negative handover to the candidate cell can be performed.

− If

the serving cell and the target cells are at different layers but have the same priority, the following conditions must be met: SS_DL(N) ≥ T_layer(N) + H_layer(S) SS_DL(N) indicates the filtered BCCH receive level of a target cell. T_layer(N) indicates HOTHRES of the target cell. H_layer(S) indicates INTELEVHOHYST of the serving cell.

− If

LoadHoEn is set to YES and the load in the serving cell is higher than TRIGTHRES, better cell handover can be triggered.

A neighboring cell becomes a target cell if the preceding conditions are met for BETTERCELLLASTTIME during BETTERCELLLASTTIME.

Target Cell Selection The requirements for target cell selection are as follows: 





3.4.11 Handover Between a Full-Rate TCH and a Half-Rate TCH This section describes the feature GBFD-115522 Dynamic HR/FR Adaptation. Handover between a full-rate TCH and a half-rate TCH performs decision based on handover algorithm II. Types of handover between a full-rate TCH and a half-rate TCH are as follows: 

AMR TCHF-TCHH handover and non-AMR TCHF-TCHH handover The purpose is to absorb more MSs and to reduce the cell congestion if the cell load is high.



AMR TCHH-TCHF handover and non-AMR TCHH-TCHF handover The purpose is to improve the speech quality of the call if the cell load is low.

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Triggering Conditions of AMR TCHF-TCHH Handover If the AMRFULLTOHALFHOALLOW is set to Yes, the triggering conditions of AMR TCHF-TCHH handover are as follows: 

SPEECHVERSION used by the call is full-rate speech version 3.



Downlink path loss of the call ≤ AMRFULLTOHALFHOPATHTHRESH + path loss handover margin



ATCB of the call ≥ AMRFULLTOHALFHOATCBTHRESH – ATCB handover margin



Uplink signal quality of the call ≤ AMRFULLTOHALFHOQUALTHRESH



Downlink signal quality of the call ≤ AMRFULLTOHALFHOQUALTHRESH



The preceding conditions are met for FULLTOHALFHOLASTTIME within FULLTOHALFHOSTATTIME.

Triggering Conditions of Non-AMR TCHF-TCHH Handover If the NOAMRFULLTOHALFHOALLOW is set to Yes, the triggering conditions of non-AMR TCHF-TCHH handover are as follows: 

SPEECHVERSION used by the call is full-rate speech version 1 or full-rate speech version 2.



Downlink path loss of the call ≤ NOAMRFULLTOHALFHOPATHTHRESH + path loss handover margin



ATCB of the call ≥ NOAMRFULLTOHALFHOATCBTHRESH – ATCB handover margin



Uplink signal quality of the call ≤ NOAMRFULLTOHALFHOATCBTHRESH



Downlink signal quality ≤ NOAMRFULLTOHALFHOATCBTHRESH



The preceding conditions are met for FULLTOHALFHOLASTTIME within FULLTOHALFHOSTATTIME.

Triggering Conditions of AMR TCHH-TCHF Handover If AMRFULLTOHALFHOALLOW is set to Yes or AMRHALFTOFULLHOQUALALLOW is set to Yes, the triggering conditions of AMR TCHF-TCHH handover are as follows: 

SPEECHVERSION used by the call is half-rate speech version 3.



Downlink path loss ≤ AMRHALFTOFULLHOPATHTHRESH



ATCB of the call ≤ AMRHALFTOFULLHOATCBTHRESH



Uplink signal quality ≥ AMRHALFTOFULLHOQUALTHRESH



Downlink signal quality of the call ≥ AMRHALFTOFULLHOQUALTHRESH



The AMR TCHH-TCHF handover is triggered if either of the preceding conditions is met for HALFTOFULLHOLASTTIME within HALFTOFULLHOSTATTIME and SPEECHVERSION is half-rate speech version 3.

Triggering Conditions of Non-AMR TCHH-TCHF Handover If NOAMRFULLTOHALFHOALLOW is set to Yes or NOAMRHALFTOFULLHOQUALALLOW is set to Yes, the triggering conditions of non-AMR TCHF-TCHH handover are as follows: 

SPEECHVERSION used by the call is half-rate speech version 1.



Downlink path loss of the call ≤ NOAMRHALFTOFULLHOPATHTHRESH



ATCB of the call ≤ NOAMRHALFTOFULLHOATCBTHRESH



Uplink signal quality of the call ≥ NOAMRHALFTOFULLHOQUALTHRESH



Downlink signal quality of the call ≥ NOAMRHALFTOFULLHOQUALTHRESH

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The non-AMR TCHH-TCHF handover is triggered if either of the preceding conditions is met for HALFTOFULLHOLASTTIME within HALFTOFULLHOSTATTIME and SPEECHVERSION is half-rate speech version 1.

Target Cell Selection Only the serving cell can be selected as the target cell of the TCHF-TCHH handover.

3.4.12 SDCCH Handover This section describes the feature GBFD-110608 SDCCH Handover. SDCCH handover is a process in which the MS is handed over from an SDCCH to another SDCCH in an immediate assignment. SDCCH handover helps improve the access success rate of the MSs on the edge of the network, thus improving the network QoS. The principle of SDCCH handover is the same as that of TCH handover. Regarding procedure, an SDCCH handover involves measurement and MR reporting, MR processing, handover decision, and handover execution. Whether an SDCCH handover can be performed is controlled by the SIGCHANHOEN parameter. If an inter-BSC SDCCH handover is required, both SIGCHANHOEN and INRBSCSDHOEN should be set to YES(Yes). The handover decision algorithm for SDCCH handover is different from that for TCH handover in the following ways: 

The algorithms for the following handovers support SDCCH handover: quick handover, TA handover, BQ handover, interference handover, handover due to no downlink measurement report, edge handover, and fast-moving micro cell handover



The algorithms for the following handovers do not support SDCCH handover: enhanced dual-band network handover, load handover, better cell handover, handover between a full-rate TCH and a half-rate TCH, better 3G cell handover, concentric cell handover, and tight BCCH handover

3.4.13 Other Handovers Other handovers here refer to better 3G cell handover and tight BCCH handover.

Better 3G Cell Handover See 2G/3G Interoperability Feature Parameter Description.

Tight BCCH Handover See BCCH Dense Frequency Multiplexing Feature Parameter Description.

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4 Parameters

4 Parameters Table 4-1 Parameter description Parameter NE ID

MML Command

Description

INTERCEL BSC6900 ADD Meaning: Hysteresis value during the handovers between cells, LHYST G2GNCELL(O This value is used to suppress ping-pong handovers between ptional) cells. MOD G2GNCELL(O GUI Value Range: 0~127 ptional) Actual Value Range: 0~127 Unit: dB Default Value: 68 HOCTRLS BSC6900 SET Meaning: Whether to use handover algorithm generation 1 or 2 WITCH GCELLHOBA currently SIC(Optional) GUI Value Range: HOALGORITHM1(Handover algorithm I), HOALGORITHM2(Handover algorithm II) Actual Value Range: HOALGORITHM1, HOALGORITHM2 Unit: None Default Value: HOALGORITHM1 HOCTRLS BSC6900 SET Meaning: Whether to use handover algorithm generation 1 or 2 WITCH GCELLHOEM currently G(Optional) GUI Value Range: HOALGORITHM1(Handover algorithm I), HOALGORITHM2(Handover algorithm II) Actual Value Range: HOALGORITHM1, HOALGORITHM2 Unit: None Default Value: HOALGORITHM1 HOCTRLS BSC6900 SET Meaning: Whether to use handover algorithm generation 1 or 2 WITCH GCELLHOFIT currently PEN(Optional) GUI Value Range: HOALGORITHM1(Handover algorithm I), HOALGORITHM2(Handover algorithm II) Actual Value Range: HOALGORITHM1, HOALGORITHM2 Unit: None Default Value: HOALGORITHM1 HOCTRLS BSC6900 SET Meaning: Whether to use handover algorithm generation 1 or 2 WITCH GCELLHOIU currently O(Optional) GUI Value Range: HOALGORITHM1(Handover algorithm I), HOALGORITHM2(Handover algorithm II) Actual Value Range: HOALGORITHM1, HOALGORITHM2 Unit: None Default Value: HOALGORITHM1

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4 Parameters

BTSMESR BSC6900 SET Meaning: Whether to enable the BTS to preprocess measurement PTPREPR GCELLHOCT reports. This parameter determines where to conduct power OC RL(Optional) control. GUI Value Range: BSC_Preprocessing(BSC preprocessing), BTS_Preprocessing(BTS preprocessing) Actual Value Range: BSC_Preprocessing, BTS_Preprocessing Unit: None Default Value: BTS_Preprocessing

PRIMMESP BSC6900 SET Meaning: Whether the BTSs send the original measurement PT GCELLHOCT reports to the BSC after pre-processing them. When this RL(Optional) parameter is set to YES, the BTSs send the original and pre-processed measurement reports to the BSC. GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: NO BSMSPWR BSC6900 SET Meaning: Whether to enable the BTS to transfer BTS/MS power LEV GCELLHOCT class to the BSC RL(Optional) GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: YES MRPREPR BSC6900 SET Meaning: Frequency at which the BTSs submit pre-processed OCFREQ GCELLHOCT measurement reports to the BSC RL(Optional) GUI Value Range: NOreport(Do not report), Twice_ps(Twice every second), Once_ps(Once every second), Once_2s(Once every two second), Once_4s(Once every four second) Actual Value Range: NOreport, Twice_ps, Once_ps, Once_2s, Once_4s Unit: None Default Value: Once_ps MEASURE BSC6900 SET Meaning: Type of the measurement report (MR) reported by the TYPE GCELLCCUT MS RANSYS(Opti onal) GUI Value Range: EnhMeasReport(Enhanced Measurement Report), ComMeasReport(Common Measurement Report) Actual Value Range: EnhMeasReport, ComMeasReport Unit: None Default Value: ComMeasReport

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4 Parameters

MRMISSC BSC6900 SET Meaning: If the number of measurement reports lost consecutively OUNT GCELLHOFIT is no larger than this value, linear interpolation is performed for the PEN(Optional) values in the lost measurement reports based on the values in the two measurement reports preceding and following the lost measurement reports. Otherwise, the lost measurement reports will be discarded, and the value will be recalculated when new measurement reports arrive. GUI Value Range: 0~31 Actual Value Range: 0~31 Unit: None Default Value: 4

POWL

BSC6900 SET Meaning: This parameter specifies the transmit power level of the GTRXDEV(Op TRX. The greater this parameter is, the smaller the transmit power tional) is. When this parameter is set to "0", the transmit power level of the TRX is the greatest. Each time this parameter increases by one level, the transmit power reduces by 2 dB. For different types of BTSs, the value range of this parameter is different. BTS3X: 0-10 BTS3001C: 0-13 BTS3002C: 0-10 Double-transceiver BTSs (BTS3012,BTS3012AE,BTS3006C): 0-10 DBS3900 GSM, BTS3900 GSM, BTS3900A GSM: 0-10. GUI Value Range: 0~13 Actual Value Range: 0~13 Unit: None Default Value: 0

SDPUNVA BSC6900 ADD L GEXT2GCEL L(Optional) MOD GEXT2GCEL L(Optional)

Meaning: Level value of the penalty that is performed on the neighboring cells of the cell where a fast-moving MS is located. The neighboring cells must be located at the Macro, Micro, or Pico layer other than the Umbrella layer. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 30

SPEEDPU BSC6900 SET Meaning: Period in which penalty is performed on the neighboring NISHT GCELLHOAD( cells of the cell where a fast-moving MS is located. The Optional) neighboring cells must be located at the Macro, Micro, or Pico layer but not the Umbrella layer. GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: s Default Value: 40

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4 Parameters

TIMEAMRF BSC6900 SET Meaning: Within the preset time, no AMR FR-to-HR handover is HPUNISH GCELLHOFIT allowed if the previous FR-to-HR handover fails due to channel PEN(Optional) unavailability or channel mismatch. GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: s Default Value: 10 INTERFER BSC6900 SET Meaning: Specifies an interval between two consecutive EHOPENTI GCELLHOFIT interference handovers ME PEN(Optional) GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: s Default Value: 15 UTOOHOP BSC6900 SET Meaning: After an MS performs a OL subcell to UL subcell ENTIME GCELLHOIU handover successfully, the MS cannot be handed over to the OL O(Optional) subcell again within the value of the parameter. GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: s Default Value: 10 HOPENAL BSC6900 SET TYTIME GCELLHOED BPARA(Optio nal)

Meaning: An MS cannot be handed over from the underlaid subcell to the overlaid subcell in this duration after the MS is handed over from the overlaid subcell to the underlaid subcell successfully. GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: s Default Value: 5

FAILSIGST BSC6900 SET Meaning: Penalty signal level imposed on a target cell to which RPUNISH GCELLHOFIT the handover fails due to congestion or poor radio quality. This PEN(Optional) penalty helps to prevent the MS from making a second handover attempt to the target cell. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 30 UMPENAL BSC6900 SET Meaning: Timer of penalty on a neighboring cell when a handover TYTIMER GCELLHOFIT fails due to faults of air interface connection. PEN(Optional) GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: s Default Value: 10

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4 Parameters

RSCPENA BSC6900 SET Meaning: Timer for punishing the neighboring cells when LTYTIMER GCELLHOFIT handover failures occur due to resource-related causes, such as PEN(Optional) resources being insufficient GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: s Default Value: 5 PENALTYT BSC6900 SET Meaning: Timer of penalty on a neighboring cell when a handover IMER GCELLHOFIT fails due to faults of data configuration. PEN(Optional) GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: s Default Value: 255 TIMEOTOU BSC6900 SET Meaning: After an OL subcell to UL subcell handover of an MS FAILPUN GCELLHOIU fails, the MS does not perform OL subell-UL subcell handovers O(Optional) within the value of the parameter. GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: s Default Value: 10 TIMEUTOO BSC6900 SET Meaning: After an UL subcell to OL subcell handover of an MS FAILPUN GCELLHOIU fails, the MS does not perform UL subcell to OL subcell handovers O(Optional) within the value of the parameter. GUI Value Range: 10~255 Actual Value Range: 10~255 Unit: s Default Value: 40 INRBSCSD BSC6900 SET Meaning: Whether to allow inter-BSC SDCCH handovers HOEN GCELLHOCT RL(Optional) GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: NO HOCDCMI BSC6900 SET Meaning: If the downlink received signal level of a neighbor cell is NDWPWR GCELLHOBA greater than "Min DL Level on Candidate Cell" plus "Min Access SIC(Optional) Level Offset", the neighbor cell can be listed in the candidate cell queue for handover. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 10

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4 Parameters

MINOFFSE BSC6900 ADD Meaning: Minimum receive level offset. T G2GNCELL(O An MS can be handed over to a neighboring cell only when the ptional) downlink level of the neighboring cell is greater than the sum of MOD "Min DL level on candidate Cell" and the value of this parameter. G2GNCELL(O ptional) GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 0 HOCDCMI BSC6900 SET Meaning: If the uplink received signal level of a neighbor cell is NUPPWR GCELLHOBA greater than "Min UL Level on Candidate Cell" plus "Min Access SIC(Optional) Level Offset", the neighbor cell can be listed in the candidate cell queue for handover. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 0 FDDREP

BSC6900 SET Meaning: This parameter specifies whether Ec/No or RSCP is GCELLCCUT used for the measurement report on a FDD cell. Ec/No stands for RANSYS(Opti the signal-to-noise ratio. RSCP stands for the received signal onal) code power. GUI Value Range: RSCP(RSCP), EcN0(Ec/N0) Actual Value Range: RSCP, EcN0 Unit: None Default Value: RSCP

MINECNOT BSC6900 ADD HRES GEXT3GCEL L(Optional) MOD GEXT3GCEL L(Optional)

Meaning: Selects 3G candidate cells. If the measured value of a 3G neighboring cell is lower than this threshold, the 3G neighboring cell will be removed from among the 3G candidate cells.

MINRSCPT BSC6900 ADD HRES GEXT3GCEL L(Optional) MOD GEXT3GCEL L(Optional)

Meaning: Selects 3G candidate cells. If the measured value of a 3G neighboring cell is lower than this threshold, the 3G neighboring cell will be removed from among the 3G candidate cells.

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GUI Value Range: 0~49 Actual Value Range: 0~49 Unit: dB Default Value: 10

GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 10


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GSM BSS Handover

4 Parameters

LOADHOP BSC6900 SET Meaning: After a load handover succeeds, the BSC punishes the ENVALUE GCELLHOFIT former serving cell during "Penalty Time on Load HO" by PEN(Optional) subtracting "Penalty Value on Load HO" from the receive level of the former serving cell, thus avoiding ping-pong handovers. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 63 LOADHOP BSC6900 SET Meaning: After a load handover succeeds, the BSC punishes the ENTIME GCELLHOFIT former serving cell during "Penalty Time on Load HO" by PEN(Optional) subtracting "Penalty Value on Load HO" from the receive level of the former serving cell, thus avoiding ping-pong handovers. GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: s Default Value: 10 DIRECTRY BSC6900 SET Meaning: Whether to enable a directed retry. The directed retry is EN GCELLBASIC to hand over an MS to a neighboring cell in the same procedure PARA(Option as the handover. The directed retry is an emergency measure al) applicable to abnormal traffic peaks in some areas of a radio network. You should not use the directed retry as a major means of solving traffic congestion. If the directed retry always occurs in some areas of a network, consider adjusting the sector and TRX configuration and the network layout. GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: YES

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4 Parameters

HOOPTSE BSC6900 SET Meaning: This parameter specifies whether a 2G cell or to a 3G L GCELLHOUT cell is preferentially selected as the target cell for handover. When RANFDD(Opti this parameter is set to Pre_2G_Cell, the BSC preferentially onal) selects a 2G candidate cell as the target cell for handover. When this parameter is set to Pre_3G_Cell, the BSC preferentially selects a 3G candidate cell as the target cell for handover. When this parameter is set to Pre_2G_CellThres, the BSC preferentially selects a neighboring 3G cell as the handover target cell if the receive level of the neighboring 2G cell that ranks the first in the candidate cell list is equal to or smaller than "HO Preference Threshold for 2G Cell". Otherwise, the BSC preferentially selects a neighboring 2G cell as the handover target cell. GUI Value Range: Pre_2G_Cell(Preference for 2G cell), Pre_3G_Cell(Preference for 3G cell), Pre_2G_CellThres(Preference 2G cell by thresh) Actual Value Range: Pre_2G_Cell, Pre_3G_Cell, Pre_2G_CellThres Unit: None Default Value: Pre_2G_CellThres

HOPRETH BSC6900 SET Meaning: If the receive level of the neighboring 2G cell that ranks 2G GCELLHOUT the first in the candidate cell list is equal to or smaller than this RANFDD(Opti threshold, the BSC preferentially selects a neighboring 3G cell as onal) the handover target cell. Otherwise, the BSC preferentially selects a neighboring 2G cell as the handover target cell. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 25 NEWURGH BSC6900 SET Meaning: Minimum interval between two consecutive emergency OMININTV GCELLHOCT handovers performed by an MS. During this interval, no RL(Optional) emergency handover is allowed. GUI Value Range: 0~60 Actual Value Range: 0~60 Unit: s Default Value: 4 QUICKHOE BSC6900 SET Meaning: Whether to allow the fast handover algorithm N GCELLHOBA SIC(Optional) GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: NO

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4 Parameters

MOVESPE BSC6900 SET Meaning: A quick handover can be initiated only if the rate of an EDTHRES GCELLHOFA MS is higher than this parameter during a certain period of time. ST(Optional) GUI Value Range: 0~600 Actual Value Range: 0~600 Unit: m/s Default Value: 35 HOUPTRIG BSC6900 SET Meaning: Fast handover can be triggered only when the uplink E GCELLHOFA signal level of the serving cell is less than this parameter. ST(Optional) GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 50 HODOWNT BSC6900 SET Meaning: Fast handover can be triggered only when the downlink RIGE GCELLHOFA level of the serving cell is less than this parameter. ST(Optional) GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 50 ISCHAINN BSC6900 ADD Meaning: Whether the cell is a chain neighboring cell. The CELL G2GNCELL(O parameter is used in the quick handover algorithm. Quick ptional) handover aims to increase the handover success rate of an MS MOD moving at a high speed and to ensure the call continuity and low G2GNCELL(O call drop rate. Quick handover applies to the scenario where an ptional) MS moves fast along an urban backbone road, a selected route, or a high-speed railroad. The target cell must be a chain neighboring cell. GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: NO HODIRFOR BSC6900 SET Meaning: Handover direction forecast switch. When this ECASTEN GCELLHOFA parameter is set to YES, the BSC can forecast the handover ST(Optional) direction of the call in fast handover so that the best target cell can be selected for handover. GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: NO

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4 Parameters

CHAINNCE BSC6900 ADD Meaning: This parameter indicates the geographical relationship LLTYPE G2GNCELL(O between the neighboring cell and the serving cell. In the BSC, if ptional) direction A is selected, then the reverse direction is B. MOD G2GNCELL(O GUI Value Range: ptional) QUICK_HO_NCELL_TYPE_A(QUICK_HO_NCELL_TYPE_A), QUICK_HO_NCELL_TYPE_B(QUICK_HO_NCELL_TYPE_B) Actual Value Range: QUICK_HO_NCELL_TYPE_A, QUICK_HO_NCELL_TYPE_B Unit: None Default Value: QUICK_HO_NCELL_TYPE_A

HODIRLAS BSC6900 SET Meaning: This parameter indicates P in the P/N rule for MS TTIME GCELLHOFA handover direction forecast. ST(Optional) P/N rule: Among N handovers, the MS is handed over to Class B chain neighboring cell for successively P times, and then the BSC determines that the MS is moving to the Class B chain neighboring cell. GUI Value Range: 0~16 Actual Value Range: 0~16 Unit: None Default Value: 3 HODIRSTA BSC6900 SET Meaning: This parameter indicates N in the P/N rule for MS TIME GCELLHOFA handover direction forecast. ST(Optional) P/N rule: Among N handovers, the MS is handed over to Class B chain neighboring cell for successively P times, and then the BSC determines that the MS is moving to the Class B chain neighboring cell. GUI Value Range: 0~16 Actual Value Range: 0~16 Unit: None Default Value: 3 TIMEPUNI BSC6900 SET Meaning: After the fast handover is successful, the penalty on the SH GCELLHOFA original serving cell is performed within the "Quick handover ST(Optional) punish time": the receive level of the original serving cell is decreased by "Quick handover punish value", to prevent ping-pong handovers. GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: s Default Value: 10

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GSM BSS Handover

4 Parameters

TIMEPUNI BSC6900 ADD SH GEXT2GCEL L(Optional) MOD GEXT2GCEL L(Optional)

Meaning: After the fast handover is successful, the penalty on the original serving cell is performed within the "Quick handover punish time": the receive level of the original serving cell is decreased by "Quick handover punish value", to prevent ping-pong handovers. GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: s Default Value: 10

HOPUNISH BSC6900 SET Meaning: To avoid ping-pong handover, the received signal of the VALUE GCELLHOFA original serving cell is decreased by "Quick handover punish ST(Optional) value" in "Quick handover punish time" after fast handover succeeds. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 63 HOPUNISH BSC6900 ADD VALUE GEXT2GCEL L(Optional) MOD GEXT2GCEL L(Optional)

TAHOEN

Meaning: To avoid ping-pong handover, the received signal of the original serving cell is decreased by "Quick handover punish value" in "Quick handover punish time" after fast handover succeeds. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 63

BSC6900 SET Meaning: Whether to enable the time advance (TA) handover. GCELLHOBA The TA handover determines whether the timing advance (TA) is SIC(Optional) higher than the predefined TA threshold. When the TA is higher than the predefined TA threshold, a TA handover is triggered. The TA is calculated based on the distance between the MS and the BTS. The longer the distance is, the greater the TA value is. GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: YES

TALIMIT

BSC6900 SET Meaning: An emergency handover is triggered when TA is greater GCELLHOEM than or equal to the value of this parameter. G(Optional) GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: bit Default Value: 255

Issue 01 (2010-06-30)


4-11

GSM BSS Handover

4 Parameters

INTERRAT BSC6900 SET Meaning: This parameter specifies whether the handover from 2G OUTBSCH GCELLHOBA cells to 3G cells is allowed. OEN SIC(Optional) GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: NO TIMETAPU BSC6900 SET Meaning: After the time advancing handover is successful, the NISH GCELLHOFIT penalty on the original serving cell is performed within the "Penalty PEN(Optional) Time after TA HO": the receive level of the original serving cell is decreased by "Penalty Level after TA HO", to prevent ping-pong handovers. GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: s Default Value: 30 SSTAPUNI BSC6900 SET Meaning: After the time advancing handover is successful, the SH GCELLHOFIT penalty on the original serving cell is performed within the "Penalty PEN(Optional) Time after TA HO": the receive level of the original serving cell is decreased by "Penalty Level after TA HO", to prevent ping-pong handovers. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 63 BQHOEN

BSC6900 SET Meaning: Whether to enable the bad quality (BQ) handover GCELLHOBA algorithm. Whether to trigger BQ handover depends on the uplink SIC(Optional) and downlink transmit quality (measured by using BER). If the uplink or downlink BQ exceeds the BQ handover threshold, emergency BQ handover is triggered. The possible causes of BER increase (or quality degradation) include too low signal power and channel interference. GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: YES

ULQUALIM BSC6900 SET Meaning: An emergency handover due to bad quality is triggered IT GCELLHOEM when the uplink receive quality is not smaller than "UL Qual. G(Optional) Threshold". GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 55

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GSM BSS Handover

4 Parameters

DLQUALIM BSC6900 SET Meaning: Downlink quality threshold for emergency handover. IT GCELLHOEM This parameter is represented as the product of 10 and a quality G(Optional) level that ranges from 0 to 7. The emergency handover can be triggered only when the downlink receive quality of an MS is greater(indicate bad quality) than this threshold. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 55 ULQUALIM BSC6900 SET Meaning: The value of this parameter corresponds to multiplying ITAMRFR GCELLAMRQ quality level 0 to 7 by 10. An emergency handover can be UL(Optional) triggered only when the uplink receive quality of the MS is greater than the value of this parameter. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 60 DLQUALIM BSC6900 SET Meaning: Downlink quality limit for emergency handover in an ITAMRFR GCELLAMRQ AMR full rate call. The value of this parameter corresponds to the UL(Optional) quality levels (0 to 7) multiplied by 10. An emergency handover can be triggered only when the downlink reception quality of an MS is higher than the value of this parameter, which indicates a poor quality. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 60 ULQUALIM BSC6900 SET Meaning: The value of this parameter corresponds to multiplying ITAMRHR GCELLAMRQ quality level 0 to 7 by 10. An emergency handover can be UL(Optional) triggered only when the uplink receive quality of the MS is greater than the value of this parameter. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 55 DLQUALIM BSC6900 SET Meaning: Downlink quality limit for emergency handover in an ITAMRHR GCELLAMRQ AMR half rate call. The value of this parameter corresponds to the UL(Optional) quality levels (0 to 7) multiplied by 10. An emergency handover can be triggered only when the downlink reception quality of an MS is higher than the value of this parameter, which indicates a poor quality. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 55

Issue 01 (2010-06-30)


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GSM BSS Handover

4 Parameters

BQMARGI BSC6900 ADD Meaning: If ("downlink level of the neighbor cell after filtering" N G2GNCELL(O "downlink level of the serving cell (after power control ptional) compensation)") > (("Inter-cell HO Hysteresis" - 64) - "BQ HO MOD Margin" + 64), the BQ handover to the neighbor cell is triggered. G2GNCELL(O ptional) GUI Value Range: 0~127 Actual Value Range: 0~127 Unit: dB Default Value: 69 INTRACEL BSC6900 SET Meaning: This parameter specifies whether the intra-cell handover LHOEN GCELLHOBA is enabled. Note: A forced intra-cell handover is not subject to this SIC(Optional) parameter. GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: NO TIMEBQPU BSC6900 SET Meaning: After a handover due to bad quality is successful, the NISH GCELLHOFIT penalty on the original serving cell is performed within the "Penalty PEN(Optional) Time after BQ HO": the receive level of the original serving cell is decreased by "Penalty Level after BQ HO", to prevent ping-pong handovers. GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: s Default Value: 10 SSBQPUNI BSC6900 SET Meaning: After a handover due to bad quality is successful, the SH GCELLHOFIT penalty on the original serving cell is performed within the "Penalty PEN(Optional) Time after BQ HO": the receive level of the original serving cell is decreased by "Penalty Level after BQ HO", to prevent ping-pong handovers. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 63 ULEDGET BSC6900 SET Meaning: If the UL receive level remains lower than the "Edge HO HRES GCELLHOBA UL RX_LEV Threshold" for a period, the edge handover is SIC(Optional) triggered. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 10

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GSM BSS Handover

4 Parameters

FLTPARAA BSC6900 SET Meaning: One of the nine parameters (filter parameters A1 to A8 1 GCELLHOEM and filter parameter B) used to configure the filter for determining G(Optional) whether the received signal level drops rapidly. The computation formula is as follows: C1(nt) = A1 x C(nt) + A2 x C(nt-t) + A3 x C(nt-2t) + ... + A8 x C(nt-7t) If C1(nt) is less than B and C(nt) is less than the threshold for edge handover, the signal level is considered dropping rapidly. In the formula, A1 to A8 are filter parameters A1 to A8 minus 10 and B is the negative of filter parameter B. C(nt) indicates the received signal level in the uplink measurement report of the serving cell received at time nt. Setting the filter helps to configure the maximum allowed signal level drop degree. GUI Value Range: 0~20 Actual Value Range: 0~20 Unit: None Default Value: 10 FLTPARAA BSC6900 SET Meaning: One of the nine parameters (filter parameters A1 to A8 2 GCELLHOEM and filter parameter B) used to configure the filter for determining G(Optional) whether the received signal level drops rapidly. The computation formula is as follows: C1(nt) = A1 x C(nt) + A2 x C(nt-t) + A3 x C(nt-2t) + ... + A8 x C(nt-7t) If C1(nt) is less than B and C(nt) is less than the threshold for edge handover, the signal level is considered dropping rapidly. In the formula, A1 to A8 are filter parameters A1 to A8 minus 10 and B is the negative of filter parameter B. C(nt) indicates the received signal level in the uplink measurement report of the serving cell received at time nt. Setting the filter helps to configure the maximum allowed signal level drop degree. GUI Value Range: 0~20 Actual Value Range: 0~20 Unit: None Default Value: 10

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4-15

GSM BSS Handover

4 Parameters


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4-16

GSM BSS Handover

4 Parameters


Issue 01 (2010-06-30)


4-17

GSM BSS Handover

4 Parameters

FLTPARAA BSC6900 SET Meaning: One of the nine parameters (filter parameters A1 to A8 7 GCELLHOEM and filter parameter B) used to configure the filter for determining G(Optional) whether the received signal level drops rapidly. The computation formula is as follows: C1(nt) = A1 x C(nt) + A2 x C(nt-t) + A3 x C(nt-2t) + ... + A8 x C(nt-7t) If C1(nt) is less than B and C(nt) is less than the threshold for edge handover, the signal level is considered dropping rapidly. In the formula, A1 to A8 are filter parameters A1 to A8 minus 10 and B is the negative of filter parameter B. C(nt) indicates the received signal level in the uplink measurement report of the serving cell received at time nt. Setting the filter helps to configure the maximum allowed signal level drop degree. GUI Value Range: 0~20 Actual Value Range: 0~20 Unit: None Default Value: 10 FLTPARAA BSC6900 SET Meaning: One of the nine parameters (filter parameters A1 to A8 8 GCELLHOEM and filter parameter B) used to configure the filter for determining G(Optional) whether the received signal level drops rapidly. The computation formula is as follows: C1(nt) = A1 x C(nt) + A2 x C(nt-t) + A3 x C(nt-2t) + ... + A8 x C(nt-7t) If C1(nt) is less than B and C(nt) is less than the threshold for edge handover, the signal level is considered dropping rapidly. In the formula, A1 to A8 are filter parameters A1 to A8 minus 10 and B is the negative of filter parameter B. C(nt) indicates the received signal level in the uplink measurement report of the serving cell received at time nt. Setting the filter helps to configure the maximum allowed signal level drop degree. GUI Value Range: 0~20 Actual Value Range: 0~20 Unit: None Default Value: 10 FLTPARAB BSC6900 SET Meaning: Trend of the received signal level of the cell during a GCELLHOEM period. This parameter helps to configure the filter for determining G(Optional) whether the received signal level drops rapidly. If this parameter is higher, a more rapid signal level drop is required to trigger the handover due to rapid signal level drop. GUI Value Range: 0~200 Actual Value Range: 0~200 Unit: None Default Value: 0

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GSM BSS Handover

4 Parameters

INTERFHO BSC6900 SET Meaning: Whether to allow the interference handover algorithm. EN GCELLHOBA Interference handovers are triggered when the receive level is SIC(Optional) higher than the receive threshold while the transmit quality is lower than the interference handover quality threshold, that is, when the MSs are subject to all kinds of radio interferences. GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: YES RXLEVOFF BSC6900 SET Meaning: For AMR FR voice services, a fixed amount of offset is GCELLAMRQ added to the corresponding grade of the received signal quality for UL(Optional) the interference handover of non-AMR FR voice services. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 5 RXQUAL1 BSC6900 SET Meaning: Threshold for the interference handover of Non-AMR GCELLAMRQ FR voice services. AMRFR refers to Adaptive Multi-Rate Full UL(Optional) Rate. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 60 BANTIME BSC6900 SET Meaning: Duration in which intra-cell handover is forbidden after GCELLHOAD( the number of consecutive intra-cell handovers reaches the Optional) maximum. Intra-cell handover can be conducted again only after this duration. GUI Value Range: 1~200 Actual Value Range: 1~200 Unit: s Default Value: 20 HOTHRES BSC6900 SET Meaning: Handover threshold during the handovers between cells GCELLHOBA on different layers or of different priorities. This value is used to SIC(Optional) suppress inter-layer ping-pong handovers. Inter-layer handover threshold of the serving cell = "Inter-layer HO threshold" - "Inter-layer HO Hysteresis"; Inter-layer handover threshold of a neighboring cell = "Inter-layer HO Threshold" + "Adjacent Cell Inter-layer HO Hysteresis" - 64. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 25

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4-19

GSM BSS Handover

4 Parameters

HOTHRES BSC6900 ADD GEXT2GCEL L(Optional) MOD GEXT2GCEL L(Optional)

Meaning: Handover threshold during the handovers between cells on different layers or of different priorities. This value is used to suppress inter-layer ping-pong handovers. Inter-layer handover threshold of the serving cell = "Inter-layer HO threshold" - "Inter-layer HO Hysteresis"; Inter-layer handover threshold of a neighboring cell = "Inter-layer HO Threshold" + "Adjacent Cell Inter-layer HO Hysteresis" - 64. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 25

INTELEVH BSC6900 ADD Meaning: Hysteresis value during the handovers between cells on OHYST G2GNCELL(O different layers or of different priorities. This value is used to ptional) suppress inter-layer ping-pong handovers. MOD G2GNCELL(O GUI Value Range: 0~127 ptional) Actual Value Range: 0~127 Unit: dB Default Value: 67 NODLMRH BSC6900 SET Meaning: Whether to enable the no-downlink measurement report OEN GCELLHOEM handover algorithm G(Optional) GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: NO NODLMRH BSC6900 SET Meaning: When a certain number of no-downlink measurement OQUALLIM GCELLHOEM reports are received consecutively and the uplink receive quality is IT G(Optional) no smaller than this parameter, no-downlink measurement report emergency handovers are triggered. No-downlink measurement report emergency handovers choose the inter-cell handover mode preferentially; however, if no candidate cells are available and intra-cell handover is enabled in the current cell, intra-cell handovers are triggered. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 50 NODLMRH BSC6900 SET Meaning: Decisions of no-downlink measurement report OALLOWLI GCELLHOEM handovers can be made only when the number of consecutive MIT G(Optional) no-downlink measurement reports in the current call is no larger than this parameter. GUI Value Range: 0~64 Actual Value Range: 0~64 Unit: None Default Value: 8

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GSM BSS Handover

4 Parameters

DATAQUA BSC6900 SET Meaning: Number of measurement reports sampled for averaging FLTLEN GCELLHOFIT the signal quality on a speech/data channel. Averaging the signal PEN(Optional) quality in multiple measurement reports helps to avoid a sharp signal quality drop due to Rayleigh fading and to ensure the comprehensiveness of a handover decision. GUI Value Range: 1~31 Actual Value Range: TCH:480~14880, step:480; SDCCH:470~14570, step:470 Unit: ms Default Value: 4 QLENSI

BSC6900 SET Meaning: For the purpose of accurately reflecting the radio GCELLCHMG environment of a network, filtering is performed on the measured AD(Optional) values in several consecutive measurement reports. This parameter indicates the number of measurement reports used for the filtering of the signal quality on signaling channels. This parameter is used to determine whether interferences exist on channels. GUI Value Range: 1~32 Actual Value Range: TCH:480~15360, step:480; SDCCH:470~15040, step:470 Unit: ms Default Value: 2

OUTLOAD BSC6900 SET Meaning: Whether to switch some of the calls in the underlay HOENABL GCELLHOED subcell to the overlay. E BPARA(Optio nal) GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: YES OUTGENO BSC6900 SET Meaning: When the load of the underlay subcell is higher than this VERLDTH GCELLHOED parameter, some of the calls in the underlay subcell will be RED BPARA(Optio switched to the overlay subcell, and channels in the overlay nal) subcell will be preferentially assigned to calls initiated in the underlay subcell as well. GUI Value Range: 0~100 Actual Value Range: 0~100 Unit: % Default Value: 80 INNSERIO BSC6900 SET Meaning: In an enhanced dual-band network, if the load of the VERLDTH GCELLHOED overlay subcell is higher than this parameter, the system cannot RED BPARA(Optio initiate an underlay-to-overlay handover. nal) GUI Value Range: 0~100 Actual Value Range: 0~100 Unit: % Default Value: 90

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4-21

GSM BSS Handover

4 Parameters

EDBSYSFL BSC6900 SET OWLEV GCELLHOED BPARA(Optio nal)

Meaning: If the current system flow control level is greater than this parameter, the handover between the underlaid and overlaid subcells due to low or high load in the underlaid subcell is not allowed. System flux thresholds correspond to the system flux obtained based on message packets, CPU load, and FID queuing load. The system flux level is the current flux control level of the system. 0-11: There are 12 flow control levels. Where, 0 indicates the lowest level and 11 indicates the highest level. The handover performed over the maximum threshold may have tremendous impacts on the system. Thus, this parameter should not be set to a higher value. 1) The flow control level algorithm for the assigned system messages: [(Average Message Usage Inner Flow Control Discard Begin Threshold)/(Inner Flow Control Discard All Threshold - Inner Flow Control Discard Begin Threshold) x 100]/10+1 (round-down for division operation). If the value is smaller than Inner Flow Control Discard Begin Threshold, Level 0 is used. If the value is equal to or greater than Inner Flow Control Discard Begin Threshold, the level is calculated. The value range is from 0 to 11. 2) Flow control threshold for the CPU to start to discard the channel access messages and paging messages: 80% . Flow control threshold for the CPU to discard all channel access messages and paging messages: 100% . CPU usage smaller than 80% corresponds to level 0. CPU usage equal to or greater than CPU flow control threshold 80% corresponds to level 2. An increase of 5% means an increase of 2 levels. Level 10 is the highest. The level value can be 0, 2, 4, 6, 8, and 10. GUI Value Range: 0~11 Actual Value Range: 0~11 Unit: None Default Value: 10

INTOINNR BSC6900 SET EXLEVTHR GCELLHOED ED BPARA(Optio nal)

Meaning: Lower threshold of the overlay level during underlay-to-overlay handovers. When the receive level of an MS is higher than this threshold, the MS can be switched to the overlay subcell. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 30

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GSM BSS Handover

4 Parameters

OUTSERIO BSC6900 SET VERLDTH GCELLHOED RED BPARA(Optio nal)

Meaning: When the load of the underlay subcell is higher than this parameter, the underlay-to-overlay load handover period subtracts a period that equals "Step Length of UL Subcell Load HO" from "UL Subcell Load Hierarchical HO Periods" every second, thus increasing the load handover speed. GUI Value Range: 0~100 Actual Value Range: 0~100 Unit: % Default Value: 90

OUTLOAD BSC6900 SET HOPERIOD GCELLHOED BPARA(Optio nal)

Meaning: When the load of the underlay subcell exceeds "UL Subcell General Overload Threshold", all the calls that are using this cell as the serving cell generate handover requests at the same time, which will suddenly increase the load of the BSC and possibly cause congestion in the overlay subcell, thus causing the handovers to fail. To solve this problem, the BSC uses the hierarchical load handover algorithm to gradually switch some of the calls in the underlay subcell to the overlay subcell. This parameter indicates the duration of each handover level. GUI Value Range: 1~255 Actual Value Range: 1~255 Unit: s Default Value: 5

OUTLOAD BSC6900 SET HOMODPE GCELLHOED RI BPARA(Optio nal)

Meaning: If the underlay load is higher than "UL Subcell Serious Overload Threshold", the underlay-to-overlay handover period subtracts a value that equals this threshold from "UL Subcell Load Hierarchical HO Periods" every second. GUI Value Range: 1~255 Actual Value Range: 1~255 Unit: s Default Value: 1

OUTLOAD BSC6900 SET Meaning: Level step during underlay-to-overlay hierarchical load HOSTEP GCELLHOED handovers BPARA(Optio nal) GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 5

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GSM BSS Handover

4 Parameters

OUTLOWL BSC6900 SET Meaning: When the load of the underlay subcell is lower than this OADTHRE GCELLHOED parameter, some of the calls in the overlay subcell will be D BPARA(Optio switched to the underlay subcell, and channels in the underlay nal) subcell will be preferentially assigned to channel requests initiated in the overlay subcell as well. GUI Value Range: 0~100 Actual Value Range: 0~100 Unit: % Default Value: 50 OUTINNRE BSC6900 SET XLEVTHRE GCELLHOED D BPARA(Optio nal)

Meaning: Lower threshold of the overlay level during overlay-to-underlay handovers. When the receive level of an MS is higher than this threshold, the MS can be switched to the underlay subcell. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 25

INNLOADH BSC6900 SET Meaning: Overlay-to-underlay load handovers are performed by OPERI GCELLHOED levels. This parameter indicates the duration of each level. BPARA(Optio nal) GUI Value Range: 1~255 Actual Value Range: 1~255 Unit: s Default Value: 10 INNLOADH BSC6900 SET Meaning: Level step during overlay-to-underlay hierarchical load OSTEP GCELLHOED handovers BPARA(Optio nal) GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 5

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GSM BSS Handover

4 Parameters

ATCBTHR BSC6900 SET ED GCELLHOED BPARA(Optio nal)

Meaning: Distance between the boundary of the overlaid subcell and the boundary of the underlaid subcell. This parameter specifies the difference between the coverage of the overlaid subcell and the coverage of the underlaid subcell in the concentric cell or dual-frequency network scenario. The boundaries of the overlaid and underlaid subcells are determined according to the relative value between the signal strength of the serving cell and the signal strength of the neighbor cell. Assume that the signal strength of the serving cell is SS(s) and that the signal strength of the neighbor cell is SS(n). If SS(s) = SS(n), the MS is on the boundary of the underlaid subcell. If SS(s) - SS(n) > "Distance Between Boudaries of Subcells", the MS is in the coverage of the overlaid subcell. In the tight BCCH handover algorithm, this parameter specifies the difference between the coverage of the TRX that carries the BCCH and the coverage of the TRX that does not carry the BCCH. The relevant computation is the same as the preceding computation. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 10

ATCBHYST BSC6900 SET GCELLHOED BPARA(Optio nal)

Meaning: Hysteresis in the distance between the boundary of the overlaid subcell and the boundary of the underlaid subcell. This parameter helps to adjust "Distance Between Boudaries of Subcells" and thus to prevent ping-pong handover between the overlaid and underlaid subcells. Assume that the signal strength of the serving cell is SS(s) and that the signal strength of the neighbor cell is SS(n). If SS(s) - SS(n) < "Distance Between Boudaries of Subcells" - "Distance Hysteresis Between Boudaries", the MS is handed over from the overlaid subcell to the underlaid subcell. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 2

CELLINEX BSC6900 MOD TP GCELL(Mand atory) ADD GCELL(Mand atory)

Issue 01 (2010-06-30)

Meaning: This parameter specifies whether a cell is the OL subcell or the UL subcell. This parameter is applied to the enhanced dualband cell. GUI Value Range: Inner(Inner), Extra(Extra) Actual Value Range: Inner, Extra Unit: None Default Value: None


4-25

GSM BSS Handover

4 Parameters

INNLOADH BSC6900 SET Meaning: Whether to allow underlay-to-overlay load handovers OEN GCELLHOED BPARA(Optio GUI Value Range: NO(No), YES(Yes) nal) Actual Value Range: NO, YES Unit: None Default Value: NO DLEDGET BSC6900 SET Meaning: Threshold for downlink edge handover. If the downlink HRES GCELLHOBA receive level remains less than this threshold for a period of time, SIC(Optional) the edge handover is triggered. If the PBGT handover algorithm is enabled, this threshold can be decreased accordingly. If the PBGT handover algorithm is disabled, over-coverage, co-channel interference, and adjacent channel interference may occur when this threshold is set improperly. In addition, to ensure uplink-downlink balance, this threshold needs to be adjusted according to the handover performance statistics and actual network performance. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 20

TRIGTHRE BSC6900 SET Meaning: The load handover is triggered when the traffic load in a S GCELLHOAD( cell is greater than the value of this parameter. Optional) GUI Value Range: 0~100 Actual Value Range: 0~100 Unit: None Default Value: 90 LoadAccTh BSC6900 SET Meaning: If the load of a cell is lower than the value of this res GCELLHOAD( parameter, the cell can admit the users handed over from other Optional) cells with higher load. Otherwise, the cell rejects such users. GUI Value Range: 0~100 Actual Value Range: 0~100 Unit: % Default Value: 80 LoadAccTh BSC6900 ADD res GEXT2GCEL L(Optional) MOD GEXT2GCEL L(Optional)

Issue 01 (2010-06-30)

Meaning: If the load of a cell is lower than the value of this parameter, the cell can admit the users handed over from other cells with higher load. Otherwise, the cell rejects such users. GUI Value Range: 0~100 Actual Value Range: 0~100 Unit: % Default Value: 80


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GSM BSS Handover

4 Parameters

LoadAccTh BSC6900 ADD res GEXT3GCEL L(Optional) MOD GEXT3GCEL L(Optional)

Meaning: If the load of a cell is lower than the value of this parameter, the cell can admit the users handed over from other cells with higher load. Otherwise, the cell rejects such users. GUI Value Range: 0~100 Actual Value Range: 0~100 Unit: % Default Value: 80

LOADHOS BSC6900 SET Meaning: In hierarchical load handovers, starting from "Edge HO TEP GCELLHOAD( DL RX_LEV Threshold", a "Load HO Step Level" is added to the Optional) upper handover threshold after every "Load HO Step Period". In this way, all the calls in the current serving cell whose receive level is in the range "Edge HO DL RX_LEV Threshold" to "Edge HO DL RX_LEV Threshold" + "Load HO Bandwidth" are switched to other cells. GUI Value Range: 1~63 Actual Value Range: 1~63 Unit: dB Default Value: 5 LOADHOP BSC6900 SET Meaning: When the load of a cell reaches or exceeds "Load HO ERIOD GCELLHOAD( Threshold", all the calls that are using this cell as the serving cell Optional) generate handover requests at the same time, which will suddenly increase the load of the processor. Under some circumstances, congestion occurs in the cell, which will result in call drop. To solve this problem, the BSC uses the hierarchical load handover algorithm to control the number of users included in each level of handovers. This parameter indicates the duration of each handover level. GUI Value Range: 1~255 Actual Value Range: 1~255 Unit: s Default Value: 10 LOADOFF BSC6900 SET Meaning: In the handover algorithm of the first generation, load SET GCELLHOAD( handovers can be performed only when the receive level of the Optional) current serving cell is in the range "Edge HO DL RX_LEV Threshold" to "Edge HO DL RX_LEV Threshold" + "Load HO Bandwidth". In the handover algorithm of the second generation, load handovers can be performed only when the level difference between the neighboring cell and the serving cell is between ("Inter-cell HO Hysteresis" - 64) - "Load HO Bandwidth" and ("Inter-cell HO Hysteresis" - 64). GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 25

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GSM BSS Handover

4 Parameters

LoadHoEn BSC6900 SET Meaning: This parameter specifies whether a traffic load-sharing GCELLHOBA handover is enabled. The load handover helps to reduce cell SIC(Optional) congestion, improve success rate of channel assignment, and balance the traffic load among cells, thus improving the network performance. The load handover is used as an emergency measure instead of a primary measure to adjust abnormal traffic burst in partial areas. If load handovers occur frequently in a partial area, the cell and TRX configuration of BTSs and the network layout should be adjusted. GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: NO SYSFLOW BSC6900 SET Meaning: System flux thresholds correspond to the system flux LEV GCELLHOAD( obtained based on message packets, CPU load, and FID queuing Optional) load. The system flux level is the current flux control level of the system. 0-11: There are 12 flow control levels. Where, 0 indicates the lowest level and 11 indicates the highest level. A load handover is allowed only when the system flux is lower than the value of this parameter. The handover performed over the maximum threshold may have tremendous impacts on the system. Thus, this parameter should not be set to a higher value. 1) The flow control level algorithm for the assigned system messages: [(Average Message Usage - Inner Flow Control Discard Begin Threshold)/(Inner Flow Control Discard All Threshold - Inner Flow Control Discard Begin Threshold) x 100]/10+1 (round-down for division operation). If the value is smaller than Inner Flow Control Discard Begin Threshold, Level 0 is used. If the value is equal to or greater than Inner Flow Control Discard Begin Threshold, the level is calculated. The value range is from 0 to 11. 2) Flow control threshold for the CPU to start to discard the channel access messages and paging messages: 80% . Flow control threshold for the CPU to discard all channel access messages and paging messages: 100% . CPU usage smaller than 80% corresponds to level 0. CPU usage equal to or greater than CPU flow control threshold 80% corresponds to level 2. An increase of 5% means an increase of 2 levels. Level 10 is the highest. The level value can be 0, 2, 4, 6, 8, and 10. GUI Value Range: 0, 8~11 Actual Value Range: 0, 8~11 Unit: None Default Value: 10

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GSM BSS Handover

4 Parameters

OutBscLoa BSC6900 SET Meaning: Whether to use external 2G neighboring cells as the dHoEn GCELLHOAD( target cells of load handovers Optional) GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: NO FRINGEHO BSC6900 SET Meaning: Whether to enable the edge handover algorithm. When EN GCELLHOBA an MS makes a call at the edge of a cell, the call may drop if the SIC(Optional) received signal level is too low. To avoid such a call drop, the edge handover algorithm is involved. When the uplink signal level of the serving cell is less than "Edge HO UL RX_LEV Threshold" or the downlink signal level of the serving cell is less than "Edge HO DL RX_LEV Threshold", the edge handover is triggered. GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: YES EDGELAST BSC6900 SET Meaning: According to the P/N rule, if the conditions for edge 1 GCELLHOBA handover are met for P seconds within N seconds, the handover SIC(Optional) is triggered. This parameter specifies the number P. GUI Value Range: 1~32 Actual Value Range: 0.5~16, step:0.5 Unit: s Default Value: 4 EDGESTA BSC6900 SET Meaning: According to the P/N rule, if the conditions for edge T1 GCELLHOBA handover are met for P seconds within N seconds, the handover SIC(Optional) is triggered. This parameter specifies the number N. GUI Value Range: 1~32 Actual Value Range: 0.5~16, step:0.5 Unit: s Default Value: 6 EDGEADJL BSC6900 ADD Meaning: According to the P/N rule, if a neighbor cell meets the ASTTIME G2GNCELL(O conditions for selecting the neighbor cell for edge handover in P of ptional) N measurement reports, the edge handover to the neighbor cell is MOD triggered. G2GNCELL(O This parameter specifies the number P. ptional) GUI Value Range: 1~32 Actual Value Range: 0.5~16, step:0.5 Unit: s Default Value: 4

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GSM BSS Handover

4 Parameters

EDGEADJ BSC6900 ADD Meaning: According to the P/N rule, if a neighbor cell meets the STATTIME G2GNCELL(O conditions for selecting the neighbor cell for edge handover in P of ptional) N measurement reports, the edge handover to the neighbor cell is MOD triggered. G2GNCELL(O This parameter specifies the number N. ptional) GUI Value Range: 1~32 Actual Value Range: 0.5~16, step:0.5 Unit: s Default Value: 6 QCKMVHO BSC6900 SET Meaning: Whether to enable the fast moving micro-cell handover EN GCELLHOBA algorithm. The fast moving micro-cell handover algorithm enables SIC(Optional) fast moving MSs to switch over to macro-cells, thus reducing the handover times. GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: NO QCKTIMET BSC6900 SET Meaning: A time threshold determined based on the radius of a H GCELLHOAD( cell and the moving speed of an MS. If the MS crosses the cell in a Optional) time period shorter than this threshold, the BSC concludes that the MS quickly passes through the cell. Otherwise, it concludes that the MS slowly passes the cell. GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: s Default Value: 15 QCKSTAT BSC6900 SET Meaning: This parameter is used in the P/N criteria decision: If an CNT GCELLHOAD( MS quickly passes through N out of P micro-cells lately, the BSC Optional) enables the fast moving micro-cell handover algorithm. This parameter corresponds to the N in the P/N criteria. GUI Value Range: 1~10 Actual Value Range: 1~10 Unit: None Default Value: 3 QCKTRUE BSC6900 SET Meaning: This parameter is used in the P/N criteria decision: If an CNT GCELLHOAD( MS quickly passes through N out of P micro-cells lately, the BSC Optional) enables the fast moving micro-cell handover algorithm. This parameter corresponds to the P in the P/N criteria. GUI Value Range: 1~10 Actual Value Range: 1~10 Unit: None Default Value: 2

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GSM BSS Handover

LAYER

4 Parameters

BSC6900 SET Meaning: Layer where a cell is located. The network designed by GCELLBASIC Huawei has four layers: Umbrella (layer 4), Macro (layer 3), Micro PARA(Option (layer 2), and Pico(layer 1). Each layer can be set with 16 al) priorities. GUI Value Range: 1, 2, 3, 4 Actual Value Range: 1, 2, 3, 4 Unit: None Default Value: 3

LAYER

BSC6900 ADD GEXT2GCEL L(Optional) MOD GEXT2GCEL L(Optional)

Meaning: A network basically consists of four layers, namely, Umbrella, Macro, Micro, and Pico. Cell priorities influence the sorting of neighboring cells during handovers as well as handover algorithms including PBGT and inter-layer handovers. For example, PBGT handovers can only occur among cells on a same layer and of a same priority level. If you assign different layers and priorities to a 1800-M cell and a 900-M cell, PBGT handovers from the 1800-M cell to the 900-M cell will not occur. This causes slow handovers even when the receive quality is good. GUI Value Range: 1, 2, 3, 4 Actual Value Range: 1, 2, 3, 4 Unit: None Default Value: 3

LEVHOEN BSC6900 SET Meaning: Whether to allow inter-layer and inter-level handovers. GCELLHOBA The inter-layer and inter-level handover algorithm is achieved SIC(Optional) through the setting of different layers and priorities for cells, which switches traffic to cells of a higher precedence (decided by "Layer of the cell" and "Cell priority" together). GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: YES LEVLAST

BSC6900 ADD Meaning: The triggering of inter-layer handovers must meet the G2GNCELL(O P/N criteria, that is, when the condition for inter-layer handovers is ptional) met for a consecutive P seconds during N seconds, an inter-layer MOD handover is triggered. This parameter corresponds to the P in the G2GNCELL(O P/N criteria. ptional) GUI Value Range: 1~32 Actual Value Range: 0.5~16, step:0.5 Unit: s Default Value: 4

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GSM BSS Handover

4 Parameters

LEVSTAT BSC6900 ADD Meaning: The triggering of inter-layer handovers must meet the G2GNCELL(O P/N criteria, that is, when the condition for inter-layer handovers is ptional) met for a consecutive P seconds during N seconds, an inter-layer MOD handover is triggered. This parameter corresponds to the N in the G2GNCELL(O P/N criteria. ptional) GUI Value Range: 1~32 Actual Value Range: 0.5~16, step:0.5 Unit: s Default Value: 6 PBGTHOE BSC6900 SET Meaning: Whether to use the PBGT handover algorithm. PBGT N GCELLHOBA handovers are based on path loss. The PBGT handover algorithm SIC(Optional) searches in real time for cells that have lower path loss and meet certain system requirements, and decides whether to perform the handovers. To avoid ping-pong handovers, PBGT handovers can occur only on TCHs and among cells on a same layer and a same priority level. GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: YES PBGTLAST BSC6900 ADD Meaning: The triggering of PBGT handovers must meet the P/N G2GNCELL(O criteria, that is, when the condition for PBGT handovers is met for ptional) a consecutive P seconds during N seconds, a PBGT handover is MOD triggered. This parameter corresponds to the P in the P/N criteria. G2GNCELL(O ptional) GUI Value Range: 1~32 Actual Value Range: 0.5~16, step:0.5 Unit: s Default Value: 4 PBGTSTAT BSC6900 ADD Meaning: The triggering of PBGT handovers must meet the P/N G2GNCELL(O criteria, that is, when the condition for PBGT handovers is met for ptional) a consecutive P seconds during N seconds, a PBGT handover is MOD triggered. This parameter corresponds to the N in the P/N criteria. G2GNCELL(O ptional) GUI Value Range: 1~32 Actual Value Range: 0.5~16, step:0.5 Unit: s Default Value: 6 PBGTMAR BSC6900 ADD Meaning: PBGT handovers to a neighboring cell are allowed only GIN G2GNCELL(O when the downlink level difference between the neighboring cell ptional) and the serving cell is larger than this parameter. When the value MOD of this parameter is smaller than 64, handovers to a neighboring G2GNCELL(O cell with a lower level than the current serving cell are allowed. ptional) GUI Value Range: 0~127 Actual Value Range: 0~127 Unit: dB Default Value: 68

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GSM BSS Handover

4 Parameters

INTRACEL BSC6900 SET Meaning: Whether to allow AMR handovers. This parameter has LFHHOEN GCELLHOBA no impact on dynamic non-AMR F-H handovers. SIC(Optional) GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: YES AMRTCHH BSC6900 SET Meaning: Whether to enable the BSC to assign AMR half rate PRIORALL GCELLCHMG channels preferentially according to the channel types allowed by OW AD(Optional) the MSC and the current TCH seizure ratio of the cell GUI Value Range: OFF(Off), ON(On) Actual Value Range: OFF, ON Unit: None Default Value: ON AMRTCHH BSC6900 SET Meaning: Load threshold for assigning half rate channels PRIORLOA GCELLCHMG preferentially. If the current TCH seizure ratio of the cell is greater D AD(Optional) than this threshold, AMR half rate channels are assigned preferentially. GUI Value Range: 0~99 Actual Value Range: 0~99 Unit: % Default Value: 55 INHOF2HT BSC6900 SET Meaning: For an AMR call, if the currently occupied channel is a H GCELLHOBA full rate channel and the Radio Quality Indication (RQI) is always SIC(Optional) higher than the threshold set by this parameter, an intra-cell F-H handover is triggered. GUI Value Range: 0~39 Actual Value Range: 0~39 Unit: None Default Value: 25 INFHHOLA BSC6900 SET Meaning: The triggering of intra-cell F-H handovers must meet the ST GCELLHOBA P/N criteria, that is, when the condition for intra-cell F-H SIC(Optional) handovers is met for P seconds during N seconds, an intra-cell F-H handover is triggered. This parameter corresponds to the P in the P/N criteria. GUI Value Range: 1~32 Actual Value Range: 0.5~16, step:0.5 Unit: s Default Value: 8

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GSM BSS Handover

4 Parameters

INFHHOST BSC6900 SET Meaning: The triggering of intra-cell F-H handovers must meet the AT GCELLHOBA P/N criteria, that is, when the condition for intra-cell F-H SIC(Optional) handovers is met for P seconds during N seconds, an intra-cell F-H handover is triggered. This parameter corresponds to the N in the P/N criteria. GUI Value Range: 1~32 Actual Value Range: 0.5~16, step:0.5 Unit: s Default Value: 10 INHOH2FT BSC6900 SET Meaning: For an AMR call, if the currently occupied channel is a H GCELLHOBA half rate channel and the Radio Quality Indication (RQI) is always SIC(Optional) lower than the threshold set by this parameter, an intra-cell H-F handover is triggered. GUI Value Range: 0~39 Actual Value Range: 0~39 Unit: None Default Value: 12 SIGCHANH BSC6900 SET Meaning: Whether to enable a handover between signaling OEN GCELLHOBA channels SIC(Optional) GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: NO TALASTTI BSC6900 ADD Meaning: The P/N criterion must be met for triggering a TA ME G2GNCELL(O handover. That is, the TA handover can be triggered only if P ptional) measurement reports among N measurement reports meet the MOD triggering conditions. This parameter corresponds to P in the P/N G2GNCELL(O criterion. ptional) GUI Value Range: 1~16 Actual Value Range: 0.5~8, step:0.5 Unit: s Default Value: 1 TASTATTI BSC6900 ADD Meaning: The P/N criterion must be met for triggering a TA ME G2GNCELL(O handover. That is, the TA handover can be triggered only if P ptional) measurement reports among N measurement reports meet the MOD triggering conditions. This parameter corresponds to N in the P/N G2GNCELL(O criterion. ptional) GUI Value Range: 1~16 Actual Value Range: 0.5~0.8, step:0.5 Unit: s Default Value: 1

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GSM BSS Handover

4 Parameters

LEVHOHY BSC6900 SET Meaning: Hysteresis value during the handovers between cells on ST GCELLHOBA different layers or of different priorities. This value is used to SIC(Optional) suppress inter-layer ping-pong handovers. Inter-layer handover threshold of the serving cell = "Inter-layer HO threshold" - "Inter-layer HO Hysteresis"; Inter-layer handover threshold of a neighboring cell = "Inter-layer HO threshold" + "Adjacent Cell Inter-layer HO Hysteresis" - 64. GUI Value Range: 0~63 Actual Value Range: 0~63 Unit: dB Default Value: 2

BQLASTTI BSC6900 ADD Meaning: According to the P/N rule, if the conditions for ME G2GNCELL(O emergency BQ handover are met in P of N measurement reports, ptional) the handover is triggered. MOD This parameter specifies the number P. G2GNCELL(O ptional) GUI Value Range: 1~16 Actual Value Range: 0.5~8, step:0.5 Unit: s Default Value: 1 BQSTATTI BSC6900 ADD Meaning: According to the P/N rule, if the conditions for ME G2GNCELL(O emergency BQ handover are met in P of N measurement reports, ptional) the handover is triggered. MOD This parameter specifies the number N. G2GNCELL(O ptional) GUI Value Range: 1~16 Actual Value Range: 0.5~8, step:0.5 Unit: s Default Value: 1 INTERFER BSC6900 SET Meaning: The triggering of interference handovers must meet the ELASTTIM GCELLHOBA P/N criteria, that is, when P out of N measurement reports meet E SIC(Optional) the condition for interference handovers, a concentric circle handover is triggered. This parameter corresponds to the P in the P/N criteria. GUI Value Range: 1~16 Actual Value Range: 0.5~8, step:0.5 Unit: s Default Value: 2 INTERFER BSC6900 SET Meaning: The triggering of interference handovers must meet the ESTATTIM GCELLHOBA P/N criteria, that is, when P out of N measurement reports meet E SIC(Optional) the condition for interference handovers, a concentric circle handover is triggered. This parameter corresponds to the N in the P/N criteria. GUI Value Range: 1~16 Actual Value Range: 0.5~8, step:0.5 Unit: s Default Value: 3

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GSM BSS Handover

4 Parameters

ULBQLAST BSC6900 ADD Meaning: The P/N criterion must be met for triggering a UL BQ TIME G2GNCELL(O handover. That is, the UL BQ handover can be triggered only if P ptional) measurement reports among N measurement reports meet the MOD triggering conditions. This parameter corresponds to P in the P/N G2GNCELL(O criterion. ptional) GUI Value Range: 1~8 Actual Value Range: 0.5~4, step:0.5 Unit: s Default Value: 1 ULBQSTAT BSC6900 ADD Meaning: The P/N criterion must be met for triggering a UL BQ TIME G2GNCELL(O handover. That is, the UL BQ handover can be triggered only if P ptional) measurement reports among N measurement reports meet the MOD triggering conditions. This parameter corresponds to N in the P/N G2GNCELL(O criterion. ptional) GUI Value Range: 1~8 Actual Value Range: 0.5~4, step:0.5 Unit: s Default Value: 1 EDGELAST BSC6900 SET Meaning: According to the P/N rule, if the conditions for edge GCELLHOBA handover are met in P of N measurement reports, the handover is SIC(Optional) triggered. This parameter specifies the number P. GUI Value Range: 1~32 Actual Value Range: 0.5~16, step:0.5 Unit: s Default Value: 1 EDGESTA BSC6900 SET Meaning: According to the P/N rule, if the conditions for edge T GCELLHOBA handover are met in P of N measurement reports, the handover is SIC(Optional) triggered. This parameter specifies the number N. GUI Value Range: 1~32 Actual Value Range: 0.5~16, step:0.5 Unit: s Default Value: 1 HCSLASTT BSC6900 ADD Meaning: According to the P/N rule, if the conditions for the IME G2GNCELL(O handover to a different micro cell due to fast movement are met in ptional) P of N measurement reports, the handover is triggered. MOD This parameter specifies the number P. G2GNCELL(O ptional) GUI Value Range: 1~16 Actual Value Range: 0.5~8, step:0.5 Unit: s Default Value: 2

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GSM BSS Handover

4 Parameters

HCSSTATT BSC6900 ADD Meaning: According to the P/N rule, if the conditions for the IME G2GNCELL(O handover to a different micro cell due to fast movement are met in ptional) P of N measurement reports, the handover is triggered. MOD This parameter specifies the number N. G2GNCELL(O ptional) GUI Value Range: 1~16 Actual Value Range: 0.5~8, step:0.5 Unit: s Default Value: 3 BETTERCE BSC6900 SET Meaning: Whether to enable the algorithm for the handover to a LLHOEN GCELLHOBA better cell SIC(Optional) GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: YES PATHLOSS BSC6900 SET Meaning: Whether to perform path loss-based sorting in a better HOEN GCELLHOBA cell handover algorithm SIC(Optional) GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: NO BETTERCE BSC6900 ADD Meaning: According to the P/N rule, if the conditions for the LLLASTTIM G2GNCELL(O handover to a better cell due to interference are met for P seconds E ptional) within N seconds, the handover is triggered. MOD This parameter specifies the number P. G2GNCELL(O ptional) GUI Value Range: 1~32 Actual Value Range: 0.5~16, step:0.5 Unit: s Default Value: 4 AMRFULLT BSC6900 SET Meaning: Whether to enable the algorithm for the load-based OHALFHO GCELLHOBA AMR handover between full rate and half rate ALLOW SIC(Optional) GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: NO SPEECHV BSC6900 SET Meaning: Speech version configured on the TRX timeslot when ERSION BTSCHNFALL the BTS works in fallback mode. When "CHNTYPE" of the TRX BACK(Mandat timeslot is set to "FULLTCH", value 0 of this parameter indicates ory) FR and value 1 indicates EFR; when "CHNTYPE" of the TRX timeslot is set to "HALFRCH", this parameter is invalid. GUI Value Range: FR(FR), EFR(EFR) Actual Value Range: FR, EFR Unit: None Default Value: FR

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GSM BSS Handover

4 Parameters

AMRFULLT BSC6900 SET OHALFHO GCELLHOBA SIC(Optional) PATHTHR ESH

Meaning: Path loss threshold for the AMR handover from full rate to half rate. If the path loss of an AMR full rate call is equal to or less than this threshold, the AMR call is handed over from full rate to half rate. GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: dB Default Value: 100

AMRFULLT BSC6900 SET OHALFHO GCELLHOBA SIC(Optional) ATCBTHR ESH

Meaning: ATCB threshold for the AMR handover from full rate to half rate. If the ATCB of an AMR full rate call is equal to or greater than this threshold, the AMR call is handed over from full rate to half rate. GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: dB Default Value: 20

AMRFULLT BSC6900 SET OHALFHO GCELLHOBA SIC(Optional) QUALTHR ESH

Meaning: Quality threshold for the AMR handover from full rate to half rate. If the uplink and downlink receive quality levels of an AMR full rate call are equal to or less than this threshold, the AMR call is handed over from full rate to half rate. GUI Value Range: 0~7 Actual Value Range: 0~7 Unit: None Default Value: 0

FULLTOHA BSC6900 SET Meaning: According to the P/N rule, if the conditions for the LFHOLAST GCELLHOBA handover from full rate to half rate are met for P seconds within N TIME SIC(Optional) seconds, the handover is triggered. This parameter specifies the number P. GUI Value Range: 1~32 Actual Value Range: 0.5~16, step:0.5 Unit: s Default Value: 4 FULLTOHA BSC6900 SET Meaning: According to the P/N rule, if the conditions for the LFHOSTAT GCELLHOBA handover from full rate to half rate are met for P seconds within N TIME SIC(Optional) seconds, the handover is triggered. This parameter specifies the number N. GUI Value Range: 1~32 Actual Value Range: 0.5~16, step:0.5 Unit: s Default Value: 6

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GSM BSS Handover

4 Parameters

NOAMRFU BSC6900 SET Meaning: Whether to allow non-AMR voice F-H handover LLTOHALF GCELLHOBA HOALLOW SIC(Optional) GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: NO NOAMRFU BSC6900 SET Meaning: When the path loss value of non-AMR full rate voice is LLTOHALF GCELLHOBA no larger than this parameter, the condition for non-AMR F-H SIC(Optional) handovers is met. HOPATHT HRESH GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: dB Default Value: 95 NOAMRFU BSC6900 SET Meaning: When the ATCB value of non-AMR full rate voice is no LLTOHALF GCELLHOBA smaller than this parameter, the condition for non-AMR F-H SIC(Optional) handovers is met. HOATCBT HRESH GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: dB Default Value: 30 AMRHALF BSC6900 SET Meaning: Whether to enable the algorithm for the uplink and TOFULLHO GCELLHOBA downlink receive quality based AMR handover from half rate to full SIC(Optional) rate QUALALLO W GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: NO AMRHALF BSC6900 SET TOFULLHO GCELLHOBA SIC(Optional) PATHTHR ESH

Meaning: Path loss threshold for the AMR handover from half rate to full rate. If the path loss of an AMR half rate call is greater than this threshold, the AMR call is handed over from half rate to full rate. GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: dB Default Value: 108

AMRHALF BSC6900 SET Meaning: ATCB threshold for the AMR handover from half rate to TOFULLHO GCELLHOBA full rate. If the ATCB of an AMR half rate call is less than this SIC(Optional) threshold, the AMR call is handed over from half rate to full rate. ATCBTHR ESH GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: dB Default Value: 4

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GSM BSS Handover

4 Parameters

AMRHALF BSC6900 SET TOFULLHO GCELLHOBA SIC(Optional) QUALTHR ESH

Meaning: Quality threshold for the AMR handover from half rate to full rate. If the receive quality level of an AMR half rate call is greater than this threshold, the AMR call is handed over from half rate to full rate. GUI Value Range: 0~7 Actual Value Range: 0~7 Unit: None Default Value: 3

HALFTOFU BSC6900 SET Meaning: According to the P/N rule, if the conditions for the LLHOLAST GCELLHOBA handover from half rate to full rate are met for P seconds within N TIME SIC(Optional) seconds, the handover is triggered. This parameter specifies the number P. GUI Value Range: 1~32 Actual Value Range: 0.5~16, step:0.5 Unit: s Default Value: 4 HALFTOFU BSC6900 SET Meaning: According to the P/N rule, if the conditions for the LLHOSTAT GCELLHOBA handover from half rate to full rate are met for P seconds within N TIME SIC(Optional) seconds, the handover is triggered. This parameter specifies the number N. GUI Value Range: 1~32 Actual Value Range: 0.5~16, step:0.5 Unit: s Default Value: 6 NOAMRHA BSC6900 SET Meaning: Whether to trigger non-AMR H-F handovers according LFTOFULL GCELLHOBA to the uplink and downlink receive quality SIC(Optional) HOQUALA LLOW GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: NO NOAMRHA BSC6900 SET Meaning: When the path loss value of non-AMR half rate voice is LFTOFULL GCELLHOBA no smaller than this threshold, the condition for non-AMR H-F SIC(Optional) handovers is met. HOPATHT HRESH GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: dB Default Value: 103 NOAMRHA BSC6900 SET Meaning: When the ATCB value of non-AMR half rate voice is no LFTOFULL GCELLHOBA larger than this threshold, the condition for non-AMR H-F SIC(Optional) handovers is met. HOATCBT HRESH GUI Value Range: 0~255 Actual Value Range: 0~255 Unit: dB Default Value: 14

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GSM BSS Handover

4 Parameters

NOAMRHA BSC6900 SET Meaning: Quality threshold for non-AMR H-F handovers. When LFTOFULL GCELLHOBA the receive quality of a user is no smaller than this parameter, the SIC(Optional) user meets the condition for H-F handovers. HOQUALT HRESH GUI Value Range: 0~7 Actual Value Range: 0~7 Unit: None Default Value: 2 RXQUAL2 BSC6900 SET Meaning: Threshold for the interference handover of Non-AMR GCELLAMRQ FR voice services. AMRFR refers to Adaptive Multi-Rate Full UL(Optional) Rate. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 50 RXQUAL3 BSC6900 SET Meaning: Threshold for the interference handover of Non-AMR GCELLAMRQ FR voice services. AMRFR refers to Adaptive Multi-Rate Full UL(Optional) Rate. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 49 RXQUAL4 BSC6900 SET Meaning: Threshold for the interference handover of Non-AMR GCELLAMRQ FR voice services. AMRFR refers to Adaptive Multi-Rate Full UL(Optional) Rate. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 48 RXQUAL5 BSC6900 SET Meaning: Threshold for the interference handover of Non-AMR GCELLAMRQ FR voice services. AMRFR refers to Adaptive Multi-Rate Full UL(Optional) Rate. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 47 RXQUAL6 BSC6900 SET Meaning: Threshold for the interference handover of Non-AMR GCELLAMRQ FR voice services. AMRFR refers to Adaptive Multi-Rate Full UL(Optional) Rate. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 46

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GSM BSS Handover

4 Parameters

RXQUAL7 BSC6900 SET Meaning: Threshold for the interference handover of Non-AMR GCELLAMRQ FR voice services. AMRFR refers to Adaptive Multi-Rate Full UL(Optional) Rate. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 45 RXQUAL8 BSC6900 SET Meaning: Threshold for the interference handover of Non-AMR GCELLAMRQ FR voice services. AMRFR refers to Adaptive Multi-Rate Full UL(Optional) Rate. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 44 RXQUAL9 BSC6900 SET Meaning: Threshold for the interference handover of Non-AMR GCELLAMRQ FR voice services. AMRFR refers to Adaptive Multi-Rate Full UL(Optional) Rate. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 43 RXQUAL10 BSC6900 SET Meaning: Threshold for the interference handover of Non-AMR GCELLAMRQ FR voice services. AMRFR refers to Adaptive Multi-Rate Full UL(Optional) Rate. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 42 RXQUAL11 BSC6900 SET Meaning: Threshold for the interference handover of Non-AMR GCELLAMRQ FR voice services. AMRFR refers to Adaptive Multi-Rate Full UL(Optional) Rate. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 41 RXQUAL12 BSC6900 SET Meaning: Threshold for the interference handover of Non-AMR GCELLAMRQ FR voice services. AMRFR refers to Adaptive Multi-Rate Full UL(Optional) Rate. GUI Value Range: 0~70 Actual Value Range: 0~70 Unit: None Default Value: 40

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GSM BSS Handover

4 Parameters

LOADHOA BSC6900 SET Meaning: This parameter specifies whether to use the load D GCELLHOAD( handover or the enhanced load handover. Optional) GUI Value Range: NO(NO), YES(YES) Actual Value Range: YES, NO Unit: None Default Value: NO LOADSTAT BSC6900 SET Meaning: This parameter specifies whether the dynamic PDCHs YPE GCELLCHMG that have been converted into the PDCHs are considered during AD(Optional) the calculation of the current cell load. GUI Value Range: NODYNPDCH(Not count dynamic PDCH), DYNPDCHASOCCUPY(Count dynamic PDCH(Occupy)), DYNPDCHASIDLE(Count dynamic PDCH(Idle)) Actual Value Range: NODYNPDCH, DYNPDCHASOCCUPY, DYNPDCHASIDLE Unit: None Default Value: DYNPDCHASIDLE DYNCHNP BSC6900 SET Meaning: Mode of preempting the dynamic channel for the CS REEMPTL GCELLPSCH domain and PS domain. Only the channel configured in the TCH/F EV M(Optional) mode can be preempted. "Preempt all dynamic TCHFs" indicates the circuit domain can preempt all the dynamic channels. "No preempt of CCHs" indicates the circuit domain can preempt all the dynamic channels except the CCHs. "No preempt of service TCHF" indicates the circuit domain cannot preempt all the dynamic channels of bearer services. GUI Value Range: LEVEL0(Preempt all dynamic TCHFs), LEVEL1(No preempt of CCHs), LEVEL2(No preempt of service TCHF) Actual Value Range: LEVEL0, LEVEL1, LEVEL2 Unit: None Default Value: LEVEL0

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GSM BSS Handover

CHTYPE

4 Parameters

BSC6900 SET Meaning: Type and function of the channel GTRXCHAN( Optional) Combined BCCH+7TCH Main BCCH+SDCCH/8+6TCH Main BCCH+2SDCCH/8+5TCH Main BCCH+SDCCH/8+extended BCCH (BCH)+5TCH Main BCCH+SDCCH/8+extended BCCH (BCH)+TCH+extended BCCH (BCH)+3TCH The BCCHs in a cell need to be configured according to the number of channels in the cell and the paging capacity in the location area. The main and combined BCCHs shall always be configured in timeslot 0. An extended BCCH can be configured only in timeslot 2, 4, or 6. If an extended BCCH is configured, the CCCH parameter in the system message data needs to be configured accordingly. For example, if an extended BCCH is configured in timeslot 2, the CCCH parameter in the system message data needs to be configured as two uncombined CCCHs. To enable cell broadcast in a cell, add a CBCH to the cell during the radio channel configuration. In the case of SDCCH/8 cell broadcast, set this parameter to SDCCH_CBCH. You can change a TCH into SDCCH+CBCH or the original SDCCH into SDCCH+CBCH. In the case of SDCCH/4 cell broadcast, set this parameter to BCCH_CBCH. With the same effect, the SDCCH/8 and SDCCH/4 cell broadcast services serve different network planning requirements. The data configurations for half-rate networking differ from the data configurations for other networking. In the case of half-rate networking, each TRX maintains high RSL traffic. Therefore, the LAPD signaling link multiplexing ratio at the Abis interface is up to 2:1. In the case of half-rate networking, each E1 supports up to 13 TRXs. If the LAPD signaling links are unmultiplexed, each E1 supports fewer TRXs.

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GUI Value Range: TCHFR(TCH Full Rate), TCHHR(TCH Half Rate), SDCCH8(SDCCH8), MBCCH(Main BCCH), CBCCH(Combined BCCH), BCH(BCH), BCCH_CBCH(BCCH+CBCH), SDCCH_CBCH(SDCCH+CBCH), PBCCH_PDTCH(PBCCH+PDTCH), PCCCH_PDTCH(PCCCH+PDTCH), PDTCH(PDTCH), DPDCH(Dynamic PDCH) Actual Value Range: TCHFR, TCHHR, SDCCH8, MBCCH, CBCCH, BCH, BCCH_CBCH, SDCCH_CBCH, PBCCH_PDTCH, PCCCH_PDTCH, PDTCH, DPDCH Unit: None Default Value: TCHFR Huawei Proprietary and Confidential 4-44 Copyright © Huawei Technologies Co., Ltd.

GSM BSS Handover

4 Parameters

LOADHOU BSC6900 SET Meaning: This parameter specifies the ratio of the MSs that SRRATIO GCELLHOAD( simultaneously perform a load handover. You can enlarge the Optional) ratio to accelerate the handover to a neighboring cell for load sharing. Too large a ratio, however, causes the neighboring cell to be congested. When a neighboring cell is congested, you need to reduce the ratio to a reasonable value. GUI Value Range: 1~16 Actual Value Range: 1~16 Unit: None Default Value: 3 LOADHOP BSC6900 ADD Meaning: If the path loss in the serving cell minus that in a BGTMARGI G2GNCELL(O handover candidate cell is not smaller than the parameter value, N ptional) the handover to the candidate cell is allowed. The parameter MOD loosens the requirement of the PBGT handover threshold when G2GNCELL(O the load of the serving cell reaches a certain level. Some traffic ptional) that could not be handed over to a neighboring cell through the PBGT handover can be handed over now. The value "0" indicates that the enhanced load handover to the neighboring cell is not allowed. GUI Value Range: 0~127 Actual Value Range: -64dB~63dB Unit: dB Default Value: 0 PRIOR

BSC6900 SET Meaning: This parameter controls handover between cells at the GCELLBASIC same layer. Generally, the cells at the same layer are set with the PARA(Option same priority. If the cells at the same layer have different priorities, al) a cell with a smaller priority value has a higher priority. GUI Value Range: PRIOR-1(Priority-1), PRIOR-2(Priority-2), PRIOR-3(Priority-3), PRIOR-4(Priority-4), PRIOR-5(Priority-5), PRIOR-6(Priority-6), PRIOR-7(Priority-7), PRIOR-8(Priority-8), PRIOR-9(Priority-9), PRIOR-10(Priority-10), PRIOR-11(Priority-11), PRIOR-12(Priority-12), PRIOR-13(Priority-13), PRIOR-14(Priority-14), PRIOR-15(Priority-15), PRIOR-16(Priority-16) Actual Value Range: PRIOR-1, PRIOR-2, PRIOR-3, PRIOR-4, PRIOR-5, PRIOR-6, PRIOR-7, PRIOR-8, PRIOR-9, PRIOR-10, PRIOR-11, PRIOR-12, PRIOR-13, PRIOR-14, PRIOR-15, PRIOR-16 Unit: None Default Value: PRIOR-1

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GSM BSS Handover

PRIOR

4 Parameters

BSC6900 ADD GEXT2GCEL L(Optional) MOD GEXT2GCEL L(Optional)

COBSCMSC BSC6900 ADJEN

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Meaning: This parameter controls the handovers among cells on a same layer. A smaller priority value indicates a higher priority. Cells with higher priorities are preferentially selected as the handover target cells. GUI Value Range: Prior-1, Prior-2, Prior-3, Prior-4, Prior-5, Prior-6, Prior-7, Prior-8, Prior-9, Prior-10, Prior-11, Prior-12, Prior-13, Prior-14, Prior-15, Prior-16 Actual Value Range: Prior-1, Prior-2, Prior-3, Prior-4, Prior-5, Prior-6, Prior-7, Prior-8, Prior-9, Prior-10, Prior-11, Prior-12, Prior-13, Prior-14, Prior-15, Prior-16 Unit: None Default Value: Prior-1

SET Meaning: Whether to adjust the candidate cell queue to give priority to GCELLHOBASI intra-BSC/MSC handover C(Optional) GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Unit: None Default Value: YES


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GSM BSS Handover

5 Counters

5 Counters For the counters, see the BSC6900 GSM Performance Counter Reference.

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GSM BSS Handover

6 Glossary

6 Glossary For the acronyms, abbreviations, terms, and definitions, see the Glossary.

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GSM BSS Handover

7 Reference Documents

7 Reference Documents [1] 3GPP TS 08.58 Base Station Controler - Base Transceiver Station (BCS-BTS) Interface Layer 3 Specification [2] 3GPP TS

04.08 Mobile radio interface layer 3 specification

[3] BSC6900 Feature List [4] BSC6900 Basic Feature Description [5] BSC6900 Optional Feature Description [6] BSC6900 GSM Parameter Reference [7] BSC6900 GSM MML Command Reference [8] BSC6900 Performance Counter Reference

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Handover.pdf

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