IMSI-Based Handover Parameter Description

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Huawei Proprietary and Confidential

RAN

IMSI-based HandoverParameter Description

Issue 02

Date 2009-06-30


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Huawei Proprietary and Confidential

Copyright Huawei Technologies Co., Ltd. 2009. All rights reserved.

No part of this document may be reproduced or transmitted in any form or by any means without priorwritten consent of Huawei Technologies Co., Ltd.

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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 respectiveholders.

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 bewithin the purchase scope or the usage scope. Unless otherwise specified in the contract, all statements,

information, and recommendations in this document are providedAS 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.

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IMSI-based Handover Contents

Issue 02 (2009-06-30) Huawei Proprietary and Confidential iii

Contents

1 Introduction to This Document .......................................................................................... 1-1

1.1 Scope ..................................................................................................................................................... 1-1

1.2 Intended Audience.................................................................................................................................. 1-1

1.3 Change History ...................................................................................................................................... 1-1

2 Overview of IMSI-based Handover ...................................................................................2-1

3 Technical Description...........................................................................................................3-1

3.1 Principles of IMSI-Based Handover........................................................................................................ 3-1

3.1.1 Mapping Between LAs and SNAs.................................................................................................. 3-1

3.1.2 Mapping Between IMSIs and SNAs............................................................................................... 3-2

3.1.3 Example of the IMSI-Based Handover ........................................................................................... 3-2

3.2 Signaling Procedure of IMSI-Based Handover........................................................................................ 3-2

3.2.1 RRC Establishment ....................................................................................................................... 3-2

3.2.2 Cell Update ................................................................................................................................... 3-3

3.2.3 URA Update.................................................................................................................................. 3-3

3.2.4 Handover....................................................................................................................................... 3-3

3.2.5 Relocation.............................................................................. ....................................................... 3-3

3.2.6 Common ID Handling ................................................................................................................... 3-3

4 Engineering Guidelines....................................................................................................... 4-1

5 Parameters.............................................................................................................................. 5-1

6 Counters .................................................................................................................................6-1

7 Glossary.................................................................................................................................. 7-1

8 Reference Documents.............................................................................................................. 2


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IMSI-based Handover 1 Introduction to This Document

Issue 02 (2009-06-30) Huawei Proprietary and Confidential 1-1

1 Introduction to This Document1.1 Scope

This document describes the principles and signaling procedure of IMSI-based handover.

1.2 Intended AudienceIt is assumed that users of this document are familiar with WCDMA basics and have aworking knowledge of 3G telecommunication.

This document is intended for:

l Personnel working on Huawei WCDMA products or systems

l System operators who need a general understanding of IMSI-based handover feature

1.3 Change HistoryThis section provides information on the changes in different document versions.

There are two types of changes, which are defined as follows:

l Feature change: refers to the change in the IMSI-based handover feature.

l 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 issues are as follows:

l 02 (2009-06-30)

l 01 (2009-03-30)

l Draft (2009-03-10)

l Draft (2009-01-15)


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IMSI-based Handover 1 Introduction to This Document


02 (2009-06-30)

This is the document for the second commercial release of RAN11.0.

Compared with 01 (2009-03-30) of RAN11.0, this issue adjusts the structure of the document.

01 (2009-03-30)

This is the document for the first commercial release of RAN11.0.

Compared with draft (2009-03-10) of RAN11.0, 01(2009-03-30) optimizes the description.

Draft (2009-03-10)

This is the second draft release of RAN11.0.

Compared with draft (2009-01-15) of RAN11.0, draft (2009-03-10) optimizes the description.

Draft (2009-01-15)

This is the first draft release of RAN11.0.


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IMSI-based Handover 2 Overview of IMSI-based Handover


2 Overview of IMSI-based HandoverThe function of shared network in connected mode is introduced in the 3GPP R5. Thisfunction can be implemented at the CN (Core Network) or be substituted by the handover

based on the IMSI (International Mobile Subscriber Identity) through the RNC.

When a UE moves from one SNA (Shared Network Areas) to a new SNA, the RNC decideswhether or not the UE is allowed to access the new SNA in compliance with the previously

configured mapping between IMSIs and SNAs. If the RNC decides that the UE is not allowedto access the new SNA, then the UE cannot access the network in that area.

With this feature, the RNC can prevent the UE in connected mode from being moved to anun-subscribed area without CN support. This feature can also be used as a supplement forimplementing shared networks solutions.


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IMSI-based Handover 3 Technical Description


3 Technical DescriptionThis part will describe the princples of IMSI-based handover and signaling procedure ofIMSI-based handover.

3.1 Principles of IMSI-Based HandoverThe IMSI-based handover is an alternative solution applied when the CN does not support thefunction of shared network in connected mode.

The following mappings must be configured on the RNC to implement the IMSI-basedhandover feature:

l Mapping Between LAs and SNAs

l Mapping Between IMSIs and SNAs

An example is provided in Example of the IMSI-Based Handover to describe the principles

of IMSI-based handover.

3.1.1 Mapping Between LAs and SNAs

The relationship between LAs and SNAs is a multiple-to-multiple one. In other words, one

SNA may consist of multiple LAs, and one LA may belong to multiple SNAs.

Figure 3-1 shows an example of the mapping between LAs and SNAs.

Figure 3-1Mapping between LAs and SNAs

In Figure 3-1,

l SNA 1 consists of LA 1, LA 2, LA 3 and LA 4.

l SNA 2 consists of LA 3, LA 4, LA 5 and LA 6.


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l LA 3 belongs to SNA 1 and SNA 2.

l LA 4 belongs to SNA 1 and SNA 2.

Each LA is identified by MCCand LAC.

Each SNA is identified by SNAC.

3.1.2 Mapping Between IMSIs and SNAs

The SNA that a UE is allowed to access is configured on the RNC side. Each UE is identified

by an IMSI. To configure more than one UE at the same time, set a range of IMSIs so that allthe UEs within the range are configured together. The range is set by ImsiMinand ImsiMax.

The IMSI ranges can be set the same but cannot overlap each other.

The SNA that the UE is allowed to access is specified by the combination of the following

parameters: MCC, MNC, SnaExistInd, and SNAC.

3.1.3 Example of the IMSI-Based Handover

When a UE is moving, the RNC allows the UE to access the target cell if an overlapped area

exists between the SNA to which the LA of the target cell belongs and the SNA that the UE(that is, the IMSI) is allowed to access. Otherwise, the RNC does not allow the UE to accessthe target cell.

For example,

l Cell 1 belongs to LA 1, and LA 1 belongs to SNA 1.

l Cell 2 belongs to LA 2, and LA 2 belongs to SNA 2.

l Cell 3 belongs to LA 3, and LA 3 belongs to SNA 3.l A range of IMSIs, 460001234100000 to 460001234200000, are mapped to SNA 1 and

SNA 2.

l The IMSI of the UE is 460001234150001, and the UE camps on cell 1 currently.

In this situation, when the UE moves, the UE is allowed to access cell 2 but cannot access cell

3.

Each UE belongs to a maximum of 6 PLMNs (Public Land Mobile Networks). Each PLMN

corresponds to a maximum of 32 SNAs. Each LA belongs to a maximum of 32 SNAs.

3.2 Signaling Procedure of IMSI-Based HandoverThe procedures affected by the IMSI-based handover are RRC establishment, cell update,URA update, handover, relocation, and common ID handling. In these procedures, the RNCperforms access control on the UE in compliance with the mapping between IMSIs and

SNAs.

3.2.1 RRC Establishment

The UE initiates the RRC (Radio Resource Control) establishment procedure by using an

RRC CONNECTION REQUEST message.


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l If this message carries IMSI information, the RNC decides whether to allow the UE toaccess the cell or not.

If the RNC allows the UE to access the cell, the UE can access the cell.

If the RNC does not allow the UE to access the cell, the RNC sends an RRC

CONNECTION REJECT message to the UE.l If this message does not carry IMSI information, the RRC connection is established

normally.

3.2.2 Cell Update

When the UE initiates a cell update in the target cell, the RNC decides whether the UE hasaccess to the target cell or not.

If the UE does not have access to the target cell, the cell update fails.

3.2.3 URA Update

The URA update is the same as the cell update.

3.2.4 Handover

During a soft handover or a hard handover, the RNC does not send a MEASUREMENT

CONTROL message if the UE does not have access to a cell. Therefore, the UE does nottrigger a measurement report of that cell. As a result, the UE cannot be handed over to thatcell.

The RNC does not select the cell that the UE is not allowed to access as the target cell when ablind handover is triggered.

3.2.5 RelocationWhen the Target RNC receives a RELOCATION REQUEST message, it decides whether theUE has access to the target cell or not.

If the UE does not have access to the target cell, the relocation failure procedure is triggered.

3.2.6 Common ID Handling

The RNC obtains the IMSI information of the UE from the COMMON ID message and

decides whether the UE has access to the current cell or not.

If the UE does not have access to the current cell, the RRC connection is released.


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IMSI-based Handover 4 Engineering Guidelines


4 Engineering GuidelinesThe subparameter RNCAP_IMSI_HO_SWITCHof PROCESSSWITCHcontrols thefunctionality of IMSI-based handover. The subparameter can be set on through the command

SET RRCTRLSWITCH.


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IMSI-based Handover 5 Parameters


5 ParametersThe following describes the parameters related to IMSI-based Handover.

For the meaning of each parameter, see Table 5-1. For the default value, value ranges, andMML commands of each parameter, see Table 5-2.

Table 5-1IMSI-based handover parameter description (1)

Parameter ID Description

LAC Identifying a location area code for a PLMN. It is defined by the operator.For detailed information of this parameter, refer to 3GPP TS 23.003.

SNAC Sharing Network Area Code.

ImsiMin The minimum of one IMSI range.

ImsiMax The maximum of one IMSI range.

SnaExistInd Indicating whether the SNAC need be configured.

TRUE: The SNAC need be configured.

FALSE: The SNAC need not be configured.UE can access any cell of thePLMN.

PROCESSSWITCH 1) INVOKE_TRACE_SWITCH. When it is checked, RNC will start

Invoke Trace procedure upon receiving INVOKE TRACE Message formCN, otherwise, RNC won't start the Invoke Trace procedure though it

receives the INVOKE TRACE message.2) SYS_INFO_UPDATE_FOR_IU_RST. When it is checked, RNC will

broadcast SYSTEM INFORMATION messages to UE when Iu reset,otherwise, RNC won't broadcast SYSTEM INFORMATION messages toUE when IU reset.3) DRNC_DIRECT_DSCR. When it is checked, DRNC will start DSCRprocedure directly in RRC states other than CELL_DCH, otherwise, DRNC

will transfer RRC CELL UPDATE message to SRNC.4) RNC_SHARE_SWITCH. When it is checked, RNC traffic sharefunction will be valid, otherwise, RNC traffic function cannot be used.

5)RNCAP_IMSI_HO_SWITCH.When it is checked, Imsi handoverfunction will be used,otherwise it will be not used.6) TERMINAL_VERSION_DEBASE_SWITCH. When it is checked,

terminal version R4 will debase to R99.

7)SYS_HO_OUT_CIPHER_SWITCH.When it is checked ,the RNC will


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Parameter ID Description

add ciphering byte at GSM HANDOVER COMMAND if the GSM systemdo not add any cipher information at that message.8)SYS_HO_CIPHER_CONFIG.When it is checked , the cipher

configuration in the added cipher byte in GSM will be A5/1.When it is nochecked ,the cipher configuration is A5/0.9)BARRED_CELL_FOR_CSDOMAIN_RST.When it is checked, cell willbe bared when CS domain is invalid, otherwise the CS domain will be

bared when CS domain is invalid. It is invalid IfSYS_INFO_UPDATE_FOR_IU_RST is not checked.10)CR2284R1_SWITCH.in section 8.6.6.28 of TS25.331 of R5 Before

2006, it describes that the HFN should add one when UE is ciphering in thesituation of Timing re-initialized hard handover,while not specified in RBSETUP process in the section of 8.6.4.3. so it is not clear whether to add

or not in RB SETUP in DRD scenarios.CR2284R1 clarify that HFN should add one in RB SETUP process with

Timing re-initialized hard handover.when it is checked ,RNC accepts this CR2284R1;when it is not checked ,RNC does not accept this CR2284R1.11)CR2284R1_COMPATIBLE_SWITCH.CR2284R1 causes thecompatible problem.if UE is not consistent with RNC regarding whether

accept the CR2284R1 or not,it will cause the problem of streaming whenUEs are communicating with each other.So RNC creates this switch .when it is checked, RNC is auto-adaptive to accept the CR2284R1

according to UE version information.The principles that RNC judges UE whether to accept the CR2284R1 are asfollows:

R5 and above UE accepts the CR;R99/R4 UE ,if it receives the START LIST value from RB SETUPCOMPLETE,RNC figures that UE accepts the CR;

R99/R4 UE ,if it only receives the START value from RB SETUPCOMPLETE,RNC figures that UE does not accept the CR ;when it is not checked, whether RNC accept the CR or not is according toCR2284R1_SWITCH.

The relations between these two switches CR2284R1_SWITCH andCR2284R1_COMPATIBLE_SWITCH are as follows:(1)CR2284R1_COMPATIBLE_SWITCH is checked, RNC is

self-compatible,so the CR2284R1_SWITCH is invalid;(2)CR2284R1_COMPATIBLE_SWITCH is not checked, theCR2284R1_SWITCH is valid.

12)CDT_MSG_FULL_TRACE:When it is checked,CDT trace function

which starts tracing from message RRC CONNECT REQUEST.13)COMBINE_OPERATION_DRD_SWITCH.When it is on,RNC will not

reject the message RB SETUP CMP without the IE active time.14)UL_INTER_PROTECT_SWITCH.When the switch is off,RNC will notdo integrity protection check foruplink RRC messages.

MCC Mobile country code of the RNC.

MNC Mobile network code of the RNC.


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Table 5-2IMSI-based handover parameter description (2)

ParameterID

DefaultValue

GUI Value Range Actual ValueRange

Unit MML Command NE

LAC - 1~65533,65535 {1~65533},{65535}

None ADDLAC(Mandatory)

ADDRAC(Mandatory)ADD

CELLSETUP(Mandatory)ADD

QUICKCELLSETUP

(Mandatory)ADD

SAC(Mandatory)

ADDNRNCCELL(Mandatory)

ADDGSMCELL(Mandatory)

ADDCZ(Mandatory)ADD

LASNAMAP(Mandatory)

RNC

SNAC - 0~65535 0~65535 None ADD

LASNAMAP(Mandatory)ADD

IMSISNAMAP(Mandatory)

RNC

ImsiMin - - 15-bit decimalnumerals

None ADD


RNC

ImsiMax - - 15-bit decimalnumerals

None ADD


RNC

SnaExistInd - TRUE, FALSE TRUE,FALSE None ADD


RNC

PROCESSSWITCH

- INVOKE_TRACE_S

WITCH,

SYS_INFO_UPDATE_FOR_IU_RST,DRNC_DIRECT_DSC

R,RNC_SHARE_SWITCH,

RNCAP_IMSI_HO_S

This

parameter is set

to 0 or 1according to therelateddomains.

None SET

RRCTRLSWITCH(Mandatory)

RNC


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ParameterID

DefaultValue

GUI Value Range Actual ValueRange

Unit MML Command NE

WITCH,

TERMINAL_VERSIO

N_DEBASE_SWITCH,

SYS_HO_OUT_CIPHER_SWITCH,SYS_HO_CIPHER_CONFIG,

BARRED_CELL_FOR_CSDOMAIN_RST,CR2284R1_SWITCH,

CDT_MSG_FULL_TRACE,CR2284R1_COMPAT

IBLE_SWITCH,COMBINE_OPERATION_DRD_SWITCH,

UL_INTER_PROTECT_SWITCH,UPLINK_MDC_ENHENCEMENT_SWITC

H,NODEB_PRIVATE_INTERFACE_SWITCH

MCC - - 000~999 None SET

MBMSPERF(Mandatory)

RNC

MNC - -00~99,000~999

None SET

MBMSPERF(Mandatory)

RNC

The Default Valuecolumn is valid for only the optional parameters.

The "-" symbol indicates no default value.


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IMSI-based Handover 6 Counters


6 CountersThe following describes the counters related to IMSI-based Handover.

For details, see theRNC Performance Counter Reference.


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IMSI-based Handover 7 Glossary


7 GlossaryFor the acronyms, abbreviations, terms, and definitions, see the Glossary.


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IMSI-based Handover 8 Reference Documents


8 Reference DocumentsThe following lists the reference documents related to the feature:

1. 3GPP TS 25.413: UTRAN Iu interface RANAP Signalling

2. 3GPP TS 25.423: UTRAN Iur Interface RNSAP Signalling

3. Basic Feature Description of Huawei UMTS RAN11.0 V1.5

4. Optional Feature Description of Huawei UMTS RAN11.0 V1.5