Technical Support Note TS-RNC-SW-046
Restriction on number of cells in SIB11/12 due to inconsistency problem in 3GPP TS 25.331 Radio Controllers RNC: RN6.0, RN7.0, RN8.0, RN8.1 mcRNC: mcRNC2.0, mcRNC3.0, mcRNC4.1 FD-RNC: I-Ada4.0, I-Ada5.0, I-Ada6.0
A p p r o v a l d a t e : 0 6 - M a r - 2 0 1 4 This document contains following type of information Informative
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Preventive Corrective Ad di ti onal on al c atego ri zati on Urgent Security Release Upgrade SW Update Information is classif ied as as Internal Public
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Customer Specific
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TS-RNC-SW-046 Copyright © 2014 Nokia Solutions and Networks. All rights reserved. CONFIDENTIAL APPROVED 15.0
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Table of Contents 1. 2. 3. 4.
Validity .......................................................... ........................................................... ....................... 3 Keywords........................................................... ........................................................... .................. 3 Summary ........................................................... ........................................................... .................. 3 Detailed description ........................................................... ........................................................... .. 3 4.1 Formula for maximum number of adjacencies ......................................................................... 4 4.2 LTE neighbour cell information........................................................... ...................................... 5 5. Solution / Instructions ...................................................................................... ............................... 6 6. Note ..................................................................................... .............................. ............................. 6 7. References ........................................................ ........................................................... .................. 6 Contact: Contact your local Nokia Solutions and Networks support.
Summary of changes: 23.12.2004 11.01.2005 11.11.2005 27.06.2006
1.0 1.1 2.0 3.0
18.09.2006 28.02.2007 02.08.2007 20.01.2009 11.12.2009 26.01.2011 26.09.2011 30.09.2011
3.1 3.2 4.0 5.0 6.0 7.0 8.0 9.0
9.12.2011
10.0
3.2.2012
11.0
20.6.2012
12.0
09.1.2013
13.0
27.5.2013
14.0
6.3.2014
15.0
The first version List of the active SW technical notes removed Updated to RN2.1 WCDMA RAN1.5 system release SW support will be discontinued TN_RNC_SW_2006_082 Software validity updated ED2 validity removed RN3.0 software validity added RN4.0 SW validity checked Removed support for RN2.2 Removed Support for RN3.0 Added RN6.0 support. Cover page updated, reference added and SIB12 restriction added. Added reference to PRFILE Descriptions document for PRFILE RN50_MAINT_11. LTE neighbor cell information added also, SIB11bis data added and other modifications. TS Note combined for RNC and I-HSPA ADA products; details and solution / instructions are still given separately for both products. Also, document was moved to a new template. Added not to sentence “When SIB Optimisation is used, the RNC does not include such cell reselection parameters to SIB11/SIB11bis which have 3GPP default value.” in chapter 4. RU40 validity checked Renamed I-HSPA Adapter to Flexi Direct RNC (FD-RNC) Merged “Detailed description” and “Solutions/instructions” chapter from different products since the content is same for all products. Formula to calculate maximum number of adjacencies is added. Spreadsheet tool SIB11_Max_Neighbours_RU30_RU40_v.xls to calculate SIB 11 size is attached with this technical note. New Template RU50 validity added Added info about SIB capacity functionality, more details in WCDMA RAN Configuration Management
TS-RNC-SW-046 Copyright © 2014 Nokia Solutions and Networks. All rights reserved. CONFIDENTIAL APPROVED 15.0
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Purpose This document contains generic information about products. These can be instructions that explain problem situations in the field, instructions on how to prevent or how to recover from problem situations, announcements about changes or preliminary information as requirements for new features or releases.
1. VALIDITY Produ ct
RU20
RU30
RU40
IPA-RNC RNC OMS for IPA-RNC (Integrated) RNC OMS (Standalone) mcRNC Flexi Direct RNC Flexi Direct OMS
X
X
X
RN5.0 RN5.0 RNC OMS 5.0
Not supported I-OMS3.0
RN6.0 RN6.0 RNC OMS 1.0
X X
mcRNC2.0 I-Ada4.0 I-OMS4.0
RN7.0 Not Supported RNC OMS 2.0
X X
mcRNC3.0 I-Ada5.0 I-OMS5.0
2. KEYWORDS RNC, FD-RNC, mcRNC, neighbour cell, RRC, SIB11, SIB12, SIB11bis
3. SUMMARY There are limitations when sending neighbour cell information in System Information Block (SIB) type 11 and 12. The SIB11 and SIB12 messages can contain information on a maximum of 96 cells, but the physical size of SIB data (no more than 3552 bits) has capacity only for 47 cells. The system information block type 11bis has capacity for extra 47 cells to be used in addition to SIB11, for 3GPP Rel-6 and newer UEs. This is introduced in RAN feature RU10: RAN1323 Extension of SIB11 (SIB11bis).
4. DETAILED DESCRIPTION 3GPP TS 25.331 Radio Resource Control (RRC) protocol specification has inconsistent requirements concerning the maximum number of neighbouring cells that can be broadcast to the UEs in the System information block 11 and 12 messages. On one hand the SIB type 11 and 12 messages can contain information on the maximum of 96 cells (32 intra-frequency cells, 32 inter-frequency cells and 32 GSM cells), but on the other hand the physical size of SIB data (no more than 3552 bits) has capacity only for 47 cells (SIB Optimization not used)/ 93 cells (SIB Optimization and the 3GPP default values for cell reselection parameters are used). The system information block type 11bis has capacity for extra 47 cells /93 cells to be used in addition to SIB11 for Rel-6 and newer UEs. Maximum numbers of each type of adjacencies that can be defined for one cell in RNC radio network database are: 31 (ADJS) Intra-frequency Adjacency 48 (ADJI) Inter-frequency Adjacency (max 32 ADJI within same UARFCN) 32 (ADJG) Inter-system Adjacency • • •
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RNC has following restrictions on the maximum number of neighbour cells that can be sent in SIB11/SIB11bis/SIB12. With SIB Optimization used (PRFILE RN50_MAINT_11 enabled) a> HCS used : 82 b> HCS not used : 93 Without SIB optimizations (PRFILE RN50_MAINT_11 disabled) a> HCS used : 35 b> HCS not used : 47
SIB Optimization can help to pack more adjacencies when operator has chosen 3GPP default values for cell reselection parameters. When SIB Optimisation is used, the RNC does not include such cell reselection parameters to SIB11/SIB11bis/SIB12 which have 3GPP default value. The cell reselection parameters are defined for intra-frequency, interfrequency and inter-system (GSM) neighbours in PDDB objects ADJS, ADJI, ADJG, HOPS, HOPI and HOPG. The default value of each cell reselection parameter in PDDB equals to the 3GPP default value. If 3GPP default values are not used for all neighbouring cells, the maximum number of neighbour cells is between 93 and 47 cells (HCS not used) depending on the configuration. The capacity is smaller (82/35 cells) when HCS (hierarchical cell structure) is used because of additional cell reselection parameters. The maximum number of neighbour cells that can be sent in SIB11/SIB11bis/SIB12 is achieved with the following parameter values:
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ADJS – AdjsEcNoOffset: 0 dB (3GPP default value). HOPS - AdjsQoffset1: 0 dB (3GPP default value). HOPS - AdjsQoffset2: 0 dB (3GPP default value). ADJS - AdjsTxPwrRACH equals to WCEL – UEtxPowerMaxPRACH). HOPS - AdjsQqualMin equals to WCEL – QqualMin. HOPS - AdjsQrxlevMin equals to WCEL–QrxlevMin. HOPI - AdjiQoffset1: 0 dB (3GPP default value). HOPI - AdjiQoffset2: 0 dB (3GPP default value). ADJI - AdjiTxPwrRACH equals to WCEL – UEtxPowerMaxPRACH. HOPI - AdjiQqualMin equals to WCEL – QqualMin. HOPI - AdjiQrxlevMin equals to WCEL–QrxlevMin HOPG - AdjgQoffset1: 0 dB (3GPP default value). HOPG - AdjgQrxlevMin equals to WCEL – QrxlevMin.
In RU20 and later releases , if the number of neighbouring cells exceeds the maximum limit, the NBAP interface is not able to pack the neighbour cell information into the SIB data and the scheduling of the system information blocks fails. The cell is blocked by the system or Block by Initialization and an alarm 7771 WCDMA CELL OUT OF USE (BCCH scheduling error or BCCH info sending failure ) is reported for the cell.
4.1 Formula for maximum number of adjacencies The formula to calculate the maximum number of adjacencies is as follows: 85 + number of ADJS*30 + number of ADJI*33 + number of ADJG*49 < 3552 In the formula, 85 bits is a fixed size and includes comp mask bits, size of first Intra frequency element and size of 1 DL frequency information ( for ADJIs) TS-RNC-SW-046 Copyright © 2014 Nokia Solutions and Networks. All rights reserved. CONFIDENTIAL APPROVED 15.0
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Note: The formula is applicable when SIB Optimization is in use and following cell selection/reselection parameters are configured with default values. For ADJS, following parameters will have default value when they are configured as defined below
•
-
UEMaxTxPower
-
QRxLevMin QQualMin Qoffset1 Qoffset2 CellIndividaulOffset
For ADJI, following parameters will have default value when they are configured as defined below
•
-
UEMaxTxPower
-
QRxLevMin QQualMin Qoffset1 Qoffset2 CellIndividaulOffset
(ADJI-AdjiTxPwrRACH equals to WCEL– UEtxPowerMaxPRACH) (HOPI - AdjiQrxlevMin equals to WCEL–QrxlevMin) (HOPI - AdjiQqualMin equals to WCEL – QqualMin) (0 dB (3GPP default value)) (0 dB (3GPP default value)) (0 default value)
For ADJG, following parameters will have default value when they are configured as defined below
•
•
(ADJS-AdjsTxPwrRACH equals to WCEL– UEtxPowerMaxPRACH).) (HOPS - AdjsQrxlevMin equals to WCEL–QrxlevMin) (HOPS - AdjsQqualMin equals to WCEL – QqualMin) (0 dB (3GPP default value)) (0 dB (3GPP default value)) (0 default value)
-
UEMaxTxPower
-
QRxLevMin Qoffset1
(ADJG - AdjgTxPwrMaxRACH equals to WCEL – UEtxPowerMaxPRACH) (AdjgQrxlevMin equals to WCEL – QrxlevMin) (0 dB (3GPP default value))
Operator can define 2 DL frequencies for Inter-frequency neighbors. So if operator uses 2 DL frequency then additional 16 bits has to be added
Note: The formula given above should be used only to get an upper limit for maximum adjacencies and should not be used to calculate exact SIB length. In case operator does not use default values then SIB length will change, and operator can use the spreadsheet tool SIB11_Max_Neighbours_RU30_RU40_v.xls attached with this technical note to calculate exact SIB length.
4.2 LTE neighbour cell information Neighbour LTE frequencies are sent in System Information Block (SIB) type 19 message and they do not affect neighbour cell information in System Information Block type 11, 11bis or 12 messages.
TS-RNC-SW-046 Copyright © 2014 Nokia Solutions and Networks. All rights reserved. CONFIDENTIAL APPROVED 15.0
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5. SOLUTION / INSTRUCTIONS When SIB Optimization (PRFILE RN50_MAINT_11) is not used, NSN guarantees 47 as maximum number of neighbours with any configuration (35 if HCS is used). The limitation of 47 neighbouring cells is met with the worst possible situation that is 32 Inter-frequency + 15 Intra frequency neighbours (32+3 with HCS). If some other configuration is used then the number of defined neighbour cells is higher before cell goes to BL(S) and the alarm 7771 is given. This means an operator can exceed the number but then the alarm 7771 must be observed. When SIB Optimization (PRFILE RN50_MAINT_11) is used, NSN guarantees 93 as the maximum number of neighbours (31 intra-frequency + 31 inter-frequency + 31 GSM neighbours) when the 3GPP default values for cell reselection parameters are used (82 if HCS is used). The operator can select the neighbouring cells that are broadcasted to the UE in the SIB type 11, 11bis and 12 messages. That is, if the total number of neighbouring cells exceeds the physical size of the SIB data, the operator can exclude specified cells (e.g. far-awayneighbours) from the SIB type 11, 11bis and 12 messages. In this case it is not necessary to restrict the number of neighbouring cells that are required for handover in CELL_DCH state of connected mode. The operator can select the neighbouring cells which are included in SIB11 or SIB11bis by means of the following neighbour cell parameters: - ADJS – AdjsSIB - ADJI – AdjiSIB - ADJG – AdjgSIB SIB12 contains the cell information which is selected in SIB11. The System Information Block type 11bis (SIB11bis) is introduced in 3GPP R6 and in RAN feature RU10: RAN1323 Extension of SIB11 (SIB11bis). The SIB capability check functionality (introduced in RU50) is controlled with the SI BCapabi l i t yCheck parameter of the RNFC object. The default value of this parameter is Disabled (0). Toenable the SIB capability check, set the value of the SI BCapabi l i t yCheck parameterto Enabled (1). See details from WCDMA RAN Configuration Management (WCDMA RAN, Operating Documentation)
6. NOTE This TS Note replaces the following TS Note: TS-IHSPA-SW-001 Restriction on number of cells in SIB11/12 due to inconsistency problem in 3GPP TS 25.331
7. REFERENCES NA04932806: Serving cell information missing after SIB optimization correction activation PRFILE Descriptions, DN0948854, WCDMA RAN, Operating Documentation WCDMA RAN Configuration Management DN70227178, Operating Documentation
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Disclaimer The information in this document is subject to change without notice and describes only the product defined in the introduction of this documentation. This documentation is intended for the use of Nokia Solutions and Networks customers only for the purposes of the agreement under which the document is submitted, and no part of it may be used, reproduced, modified or transmitted in any form or means without the prior written permission of Nokia Solutions and Networks. The documentation has been prepared to be used by professional and properly trained personnel, and the customer assumes full responsibility when using it. Nokia Solutions and Networks welcomes customer comments as part of the process of continuous development and improvement of the documentation. The information or statements given in this documentation concerning the suitability, ca pacity, or performance of the mentioned hardware or software products are given “as is” and all liability arising in connection with such hardware or software products shall be defined conclusively and finally in a separate agreement between Nokia Solutions and Networks and the customer. However, Nokia Solutions and Networks has made all reasonable efforts to ensure that the instructions contained in the document are adequate and free of material errors and omissions. Nokia Solutions and Networks will, if deemed necessary by Nokia Solutions and Networks, explain issues which may not be covered by the document. Nokia Solutions and Networks will correct errors in this documentation as soon as possible. IN NO EVENT WILL NOKIA SOLUTIONS AND NETWORKS BE LIABLE FOR ERRORS IN THIS DOCUMENTATION OR FOR ANY DAMAGES, INCLUDING BUT NOT LIMITED TO SPECIAL, DIRECT, INDIRECT, INCIDENTAL OR CONSEQUENTIAL OR ANY LOSSES, SUCH AS BUT NOT LIMITED TO LOSS OF PROFIT, REVENUE, BUSINESS INTERRUPTION, BUSINESS OPPORTUNITY OR DATA,THAT MAY ARISE FROM THE USE OF THIS DOCUMENT OR THE INFORMATION IN IT. This documentation and the product it describes are considered protected by copyrights and other intellectual property rights according to the applicable laws. NSN is a trademark of Nokia Solutions and Networks. Nokia is a registered trademark of Nokia Corporation. Other product names mentioned in this document may be trademarks of their respective owners, and they are mentioned for identification purposes only. Copyright © 2014 Nokia Solutions and Networks. All rights reserved
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