Imsi Based Handover

IMSI-based Handover

DN0481735Issue 2-0 en

# Nokia Siemens Networks 1 (39)

BSC3119Nokia BSC/TCSM, Rel. S12, ProductDocumentation, v.3

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2 (39) # Nokia Siemens Networks DN0481735Issue 2-0 en

IMSI-based Handover

Contents

Contents 3

List of tables 4

List of figures 5

Summary of changes 7

1 Overview of IMSI-based Handover 9

2 Requirements for IMSI-based Handover 13

3 Technical description of IMSI-based Handover 153.1 Interworking 153.2 Restrictions 16

4 Functionality of IMSI-based Handover 174.1 Usage of Authorised Networks and Subscriber Groups 184.2 Support for IMSI-based handover to GSM cell 194.3 Support for IMSI-based handover to WCDMA cell 214.4 Scenarios for IMSI-based handover usage 23

5 Effects of IMSI-based Handover on interfaces 35

6 User interface of IMSI-based Handover 37



Contents

List of tables


IMSI-based Handover

List of figures

Figure 1. Mapping of subscribers to permitted GSM and WCDMA networks 18

Figure 2. IMSI-based Handover between GSM networks 20

Figure 3. IMSI-based Handover between a GSM and a WCDMA network 22



List of figures


IMSI-based Handover

Summary of changes

Changes between document issues are cumulative. Therefore, the latestdocument issue contains all changes made to previous issues.

Changes made between issues 2 and 1–1

In Overview of IMSI-based Handover, references have been improved.

A reference to Nokia Flexi EDGE has been added to the list ofrequirements for BTS software versions in Requirements for IMSI-basedHandover.

Changes made between issues 1–1 and 1

Requirements for IMSI-Based Handover

The requirements have been updated.

Technical description of IMSI-Based Handover

Interworking has been updated.

Functionality of IMSI-Based Handover

Chapter Usage of Authorised networks and Subscriber groups has beenadded.

Chapter Support for IMSI-based handover to GSM cell has been updated.Figure IMSI-Based Handover between GSM networks has been redrawn.

Chapter Support for IMSI-based handover to WCDMA cell has beenupdated. Figure IMSI-Based Handover between a GSM and a WCDMAnetwork has been redrawn.

Chapter Scenarios for IMSI-based handover usage has been added.



Summary of changes


IMSI-based Handover

1 Overview of IMSI-based Handover

After the WCDMA network deployment has taken place, the GSM/EDGEcells can have four types of neighbouring cells:

. Operator's own GSM/EDGE cells

. Operator's own WCDMA cells

. GSM/EDGE cells of a greenfield operator

. WCDMA cells of a greenfield operator

The purpose of the IMSI-based Handover (IBHO) is to enable the mobilesubscriber in a home or visited network to measure selectively only thecells of specified public land mobile network (PLMN) areas and to makehandovers to specified PLMNs. The function of this application software isbased on the international mobile subscriber identity, IMSI.

Benefits

The main benefit of IMSI-based Handover is that the handover access ofthe other operators' subscribers can be limited only to defined cells tomaintain service preference to own subscribers. The other operators canprefer their own cells and thus optimise costs caused by network visits.

The IMSI-based Handover application software consists of two partsdepending on which network type the handover is directed to:

. Support for IMSI-based handover to GSM cell

. Support for IMSI-based handover to WCDMA cell

Support for IMSI-based handover to WCDMA cell requires that the GSM-WCDMA Inter-System Handover is enabled.

The IMSI-based Handover is an application software and requires a validlicence in the BSC. For more information, see Licensing in BSC.



Overview of IMSI-based Handover

The Packet Switched IBHO is currently not implemented.

For activating and deactivating the application software, see Activatingand Testing BSS12158: IMSI-based Handover.

Compliance

The IMSI-based Handover complies with the 3GPP standards.

The IMSI information element is always handled in the HANDOVERREQUEST and COMMON ID messages because of IBHO. For moreinformation, see 3GPP TS 48.008: Mobile-services Switching Centre -Base Station System (MSC - BSS) interface; Layer 3 specification, version4.8.0, Rel4.

Related topics in IMSI-based Handover

. Requirements of IMSI-based Handover

. Technical description of IMSI-based Handover

. Functionality of IMSI-based Handover

. Effects of IMSI-based Handover

. User interface of IMSI-based Handover

Other related topics in BSC/TCSM documentation

. Test and Activate. Radio Network Performance

. BSS12158: IMSI-based Handover. Activating and Testing BSS12158: IMSI-based

Handover. Operability

. BSS2132: Double BCCH Allocation List. Activating and Testing BSS2132: Double BCCH

Allocation List

. Reference. Commands

. MML Commands. E4 – Authorised Networks and Subscriber Group

Handling. EE – Base Station Controller Parameter Handling

in BSC. EQ – Base Transceiver Station Handling in BSC


IMSI-based Handover

. Counters/Performance Indicators. Call Control Measurements (CSW)

. 51 BSC Level Clear Code (PM) Measurement

. 104 IMSI-based Handover Measurement. Parameters

. BSS Radio Network Parameter Dictionary

. Descriptions. Feature Descriptions

. Radio Network Performance. Dynamic Frequency and Channel Allocation. GSM-WCDMA Interworking



Overview of IMSI-based Handover


IMSI-based Handover

2 Requirements for IMSI-based Handover

The basic requirements for the IMSI-based Handover are:

. The BSC is a Nokia equipment.

. At least 32-kbit/s links are recommended. 16-kbit/s telecomsignalling links on Abis interface are not powerful enough in the cellswhere the IMSI-based Handover is enabled and Half Rate codecsare used.

. The MSC always sends the IMSI (regardless of mobile's DualTransfer Mode capability) to the BSC in the HANDOVER REQUESTand COMMON ID messages when it is available in the MSC. TheNokia MSC with M12 or newer software has this functionality.

. The Multiple-PLMN and Inter-PLMN Handover Support in MSC andHLR must be enabled in the MSC to make the handover betweenPLMNs possible.

. In the MSC, configuration of handover agreement lists (related to theFN1168: Multiple-PLMN and Inter-PLMN Handover Support in MSCand HLR function in Nokia MSC) is needed in order to preventhandovers to an unwanted PLMN on the SDCCH channel whenfiltered subscriber-specific neighbour cell lists are not sent to the MS.

Requirements for BTS SW versions are:

. Nokia UltraSite CX4.1 or newer

. Nokia MetroSite CXM4.1 or newer

. Nokia Talk-family and Nokia PrimeSite DF7 CD1 or newer

. Nokia Flexi EDGE (any software release)

IMSI-based Handover is not supported by the Nokia 2nd generation andNokia InSite BTSs.



Requirements for IMSI-based Handover

Requirements for sending IMSI

The IMSI-based Handover application software is based on theinternational mobile subscriber identity (IMSI). It is a combination of MobileCountry Code (MCC) + Mobile Network Code (MNC) + Mobile SubscriberIdentification Number (MSIN).

The MSC sends the IMSI to the BSC at the beginning of the call in aCOMMON ID message. In case of an Inter-BSC, or Inter-System (BSC-RNC) Handover, the MSC sends the IMSI in the HANDOVER REQUESTmessage. If the Inter-BSC or GSM-WCDMA Inter-System Handover takesplace before the MSC has IMSI, the MSC sends the COMMON IDmessage to the target BSC after receiving the IMSI. The BSC retains theIMSI during an active call.

IMSI transmission is controlled with the COMMON ID supported option forBSSAP, which has to be set on in the MSC. For instructions on configuringIMSI transmission in the MSC, see Base Station Controller Handling inMSC in MSC documentation.

For an overview, see Overview of IMSI-based Handover.


IMSI-based Handover

3 Technical description of IMSI-basedHandover

IMSI-based Handover has effects on the use of some application andoperating software products.

3.1 Interworking

Inter-System Handover

The Inter-System Handover must be enabled in the BSC before the IMSI-based handover to WCDMA cell can work.

For more information, see GSM-WCDMA Interworking.

Inter-PLMN Handover

If the IMSI based handover GSM enabled (IGE) parameter has value'Y', then it should also be noted that the GSM PLMN priorisation (GPP)parameter affects the PLMN prioritisation in IMSI-based handovers toGSM.

Dynamic Frequency and Channel Allocation (DFCA)

If the SEG-specific parameter IMSI based handover GSM enabled(IGE) has value 'Y', the idle BA list cannot be used in active mode. Thisaffects the reporting from the undefined neighbour cells and weakens thefunctioning of the DFCA in a call set-up. Therefore, it is recommended thatthe IMSI-based handover to GSM cell and DFCA should not be usedsimultaneously, because the simultaneous use weakens the functionalityof the DFCA considerably. The IMSI-based handover to WCDMA cell andDFCA can be used simultaneously without restrictions. For moreinformation, see Dynamic Frequency and Channel Allocation.



Technical description of IMSI-based Handover

Enhanced Measurement Reporting (EMR)

The SI5x messages are sent according to the default ANE (IMSI basedhandover GSM cells anonymous ms (IBGA)) on the SDCCH channel,that is, the GSM/EDGE neighbours are measured according to the defaultANE list. This means that the IMSI-based selective neighbour measuringis not possible on the SDCCH.

On the TCH, the call-specific SI5x and MI messages are sent from thebeginning of the channel reservation, and the mobile starts to measure thecall-specific neighbours and report with EMR as soon as it has receivedthe SI and MI messages.

3.2 Restrictions

Do not use the following measurements in the same cell where the IMSI-based handover to GSM cell is enabled:

. Undefined Adjacent Cell Measurement

. Channel Finder Measurement

. Statistical Support for Automated Planning

. Automated Planning Enhancement

The above-mentioned measurements require the use of an Idle State Listduring a call and IMSI-based handover to GSM cell cannot be enabled, ifthe Idle State List is in use.

Double BCCH Allocation List

The IMSI-based handover to GSM cell requires that the Neighbour CellList is used for active mobiles.

If the IMSI-based handover to GSM cell is used in a cell, the use of IdleState List for active MSs is forbidden. This means that the existing SEGlevel parameter BCCH allocation usage for active MS (ACT) is notallowed to have value 'IDLE', if the existing SEG level parameteridentification of BCCH frequency list (IDLE) has another valuethan 0. For more information, see Activating and Testing BSS2132: DoubleBCCH Allocation List.



IMSI-based Handover

4 Functionality of IMSI-based Handover

The purpose of the IMSI-based Handover is to enable a control ofhandovers between networks of different operators according to theidentity (IMSI) of a subscriber. With IMSI-based Handover, a host GSMoperator is able to define that the BSC performs handovers only to thecells, which are permitted for the subscribers. The IMSI-based Handoveralso introduces a handover trigger which directs subscribers from theshared or roamed network to the subscribers' home PLMN.

The IMSI-based Handover consists of two parts:

. 4.2 Support for IMSI-based handover to GSM cell, which deals withhandovers between GSM networks.

. 4.3 Support for IMSI-based handover to WCDMA cell, which dealswith handovers from the serving GSM network to the WCDMAnetworks.

Both parts of IBHO application software can be separately activated anddeactivated on the cell level by an operator.

This application software is controlled with on/off type licence, which istime dependent.

Support for IMSI-based handover to GSM cell can be activated if a periodof validity of IBHO feature licence has not expired.

Support for IMSI-based handover to WCDMA cell can be activated if aperiod of validity of IBHO feature licence has not expired and the Inter-System Handover (ISHO) is active in the BSC.



Functionality of IMSI-based Handover

4.1 Usage of Authorised Networks and SubscriberGroups

An IMSI is a worldwide unique number sequence. It consists of three parts:Mobile Country Code (MCC), Mobile Network Code (MNC), and MobileSubscriber Identification Number (MSIN). A home PLMN is a combinationof MCC and MNC of a subscriber's IMSI.

Subscriber Group (SG) refers to all subscribers of one operator, which areidentified with the same home PLMN code of IMSI.

Authorised Networks (ANE) contains a set of network PLMN identifierswhich are used to select permitted cells from all neighbour cells of aserving cell.

Figure 1. Mapping of subscribers to permitted GSM and WCDMA networks

The operator links an SG to an ANE if the operator wants that the BSCuses a limited neighbour cell list for the SG. The BSC automatically addsGSM neighbours of the host operator's network to every neighbour GSMcell list. Therefore, the host GSM operator does not need to add a networkidentifier of its own GSM network to Authorised Networks lists.

Subscriber ofOperator ’Y’

ND (Not defined)

Subscriber ofOperator ’X’

Subscriber ofOperator ’G’

Subscriber ofOperator ’S’

AuthorisedNetworks (ANE)

1. ANE2. ANE3. ANE4. ANE5. ANE6. ANE7. ANE8. ANE9. ANE10. ANE

3. Operator ’Y’ (Italy)

128. Operator ’G’ (USA)

SubscriberGroups (SG)

1. Operator ’X’ (Italy)

2. Operator ’D’ (Norway)

BSS of GSM operator ’F’ in Italy

Anonymous subscribers

Search


IMSI-based Handover

If an ANE is not defined for an SG, the BSC uses full neighbour GSM celland neighbour WCDMA cell lists for the SG.

The BSC uses a full neighbour GSM cell list for all subscribers if theparameter IMSI based handover GSM enabled (IGE) has value 'N' inthe serving GSM cell.

The BSC uses a full neighbour WCDMA cell list for all subscribers if theparameter IMSI based handover WCDMA enabled (IWE) has value 'N'in the serving GSM cell.

The BSC uses a subscriber's IMSI information to recognise the mobileuser on the dedicated mode if either Support for IMSI-based handover toGSM cell or Support for IMSI-based handover to WCDMA cell is activatedon a serving cell.

The BSC treats a mobile user as an anonymous subscriber, if thesubscriber's IMSI information is not received from the MSC, or thesubscriber cannot be linked to any of the SGs according to its homePLMN. An anonymous subscriber is allowed to measure selectively onlyspecified PLMN cells from networks according to parameters IMSI basedhandover GSM cells anonymous MS (IBGA) and IMSI basedhandover WCDMA cells anonymous MS (IBWA).

A host GSM operator can handle the majority of the subscriber groups asanonymous mobile subscribers, which means that the host GSM operatorneeds to define the most suitable BSC-level default ANEs for anonymousmobile subscribers. Therfore it is not necessary to create subscribergroups for all inbound roaming operators.

If a subscriber's home PLMN is introduced in a certain SG, the BSC usesthe SG-related ANE to define permitted neighbour cells for the subscriberon the dedicated mode.

4.2 Support for IMSI-based handover to GSM cell

The IMSI-based handover to GSM cell can be used, for example, in thefollowing cases:

. The host GSM operator offers GSM coverage in the same countryfor several competing GSM operators.

. The host GSM operator offers GSM coverage in the same countryfor several co-operating GSM operators.




. The host GSM operator wants the BSS to prevent unnecessary HOattemps of its own subscribers to the client operator's GSM network.

. The client GSM operator wants to transfer own subscribers to itsown network whenever possible.

Figure 2. IMSI-based Handover between GSM networks

One or several GSM operators can compose a GSM network group, whichacquires GSM coverage from a GSM host operator in the same country. Itis also possible that a GSM network group acquires GSM coverage from aGSM host operator, which operates on both sides of the country bordersand has neighbour cells from several networks across the country border.

The GSM host operator is able to make GSM roaming agreements withseveral GSM network groups, which are co-operating or partly co-operating with each other.

The GSM host operator can continue existing GSM or WCDMA roamingagreements with operators, which do not have their own GSM network orare not using any GSM network of the other operators in the country. Itmeans that after IMSI-based handover activation, new handover targetcells can be defined in the network of the host GSM operator without anyimpact on the handover paths for the current roaming subscribers.

GSM (A) GSM (A) GSM (A) GSM (A) GSM (A) GSM (A)

GSM (B) GSM (B) GSM (B) GSM (B)

GSM (C) GSM (C) GSM (C) GSM (C) GSM (C)

IBHO to homenetwork for

subscribers ofoperator C (Client)when network

coverage becomesavailable


subscribers ofoperator B (Client)when network


Subscribers ofoperator A (Host) stay

in home network


IMSI-based Handover

The GSM host operator composes an Authorised Networks list into theBSC due to these cases.

The roaming and sharing concepts must be agreed before a subscribergroup can be attached as users of one of existing Authorised Networks.

When the IMSI based handover GSM enabled (IGE) parameter hasvalue 'Y', the IMSI-based Handover to GSM cell is initiated to a neighbourGSM cell of ANE as soon as the coverage of at least one neighbour GSMcell of ANE is available, that is, the following equation is met:

AV_RXLEV_NCELL(n) > RxLevMinCell(n) + MAX(0, Pa)

An IMSI-based handover to GSM cell is initiated to a cell, which belongs toanother PLMN than the serving cell. Neighbour GSM cells are alwaysincluded in the neighbour cell list if the cells belong to the same network asthe serving GSM cell.

If neighbour GSM cells belong to the same Authorised Networks, the cellshave equal handover target priority compared to each other regardless ofbelonging to one or several PLMN areas. The GSM cells are put in apriority order according to the results of signal quality measurements,which are done and reported by the MS to the host GSM network.

4.3 Support for IMSI-based handover to WCDMA cell

The IMSI-based handover to WCDMA cell can be used, for example, in thefollowing cases:

. The host GSM operator offers GSM coverage in the same countryfor several competing WCDMA operators.

. The host GSM operator also has an own WCDMA network (andsubscribers) in the same country.

. The host GSM operator wants to prevent handover attempts of itsown subscribers from the GSM network to other operators' WCDMAnetwork(s).

. The host GSM operator wants to prevent handover attempts of otheroperators' subscribers from the GSM network to its own WCDMAnetwork.




Figure 3. IMSI-based Handover between a GSM and a WCDMA network

One or several WCDMA operators can compose a WCDMA networkgroup, which acquires GSM coverage from a GSM host operator in thesame country. It is also possible that a WCDMA network group acquiresGSM coverage from a GSM host operator, which operates on both sides ofthe country borders and has neighbour cells from several networks acrossthe country border.

The GSM host operator is able to make GSM roaming agreements withseveral WCDMA network groups, which are co-operating or partly co-operating with each other.

The GSM host operator can continue existing GSM or WCDMA roamingagreements with operators, which do not have their own WCDMA networkor are not using any WCDMA network of the other operators in the country.It means that after IMSI-based handover activation, new handover targetcells can be defined in the network of the host GSM operator without anyimpact to the handover paths for the current roaming subscribers.

The GSM host operator composes an Authorised Networks list into theBSC because of these cases.

WCDMA (B) WCDMA (B) WCDMA (B) WCDMA (B)

GSM (A) GSM (A) GSM (A) GSM (A) GSM (A) GSM (A)


subscribers ofoperator C (Client)when network



subscribers ofoperator B (Client)when network


Normal ISHO controlfor subscribers ofoperator A (Host) in

home network

WCDMA (C) WCDMA (C) WCDMA (C) WCDMA (C) WCDMA (C)

WCDMA (A) WCDMA (A) WCDMA (A) WCDMA (A)WCDMA (A)


IMSI-based Handover

The roaming and sharing concepts must be agreed before a subscribergroup can be attached as users of one of existing Authorised Networks.

When the IMSI based handover WCDMA enabled (IWE) parameter hasvalue 'Y', the IMSI-based Handover to WCDMA cell is initiated to aneighbour WCDMA cell of the greenfield operator as soon as the coverageof at least one neighbour WCDMA cell of the greenfield operator isavailable, that is, the following equation is met:

AV_ECNO_NCELL(n) > minimum CPICH Ec/Io level(n)

If neighbour WCDMA cells belong to the same Authorised Networks, thecells have equal handover target priority compared to each otherregardless of belonging to only one or several PLMN areas. The WCDMAcells are set into priority order according to results of signal qualitymeasurements, which are done and reported by the MS to the host GSMnetwork.

4.4 Scenarios for IMSI-based handover usage

The following scenario lists the necessary steps for taking IMSI-basedhandover in use in the BSC:

1. Install a valid IBHO licence.

2. Add network PLMNs into Authorised Networks (ANE) (to whichcertain subscribers will have equal handover access rights).

3. Define Subscriber Groups (SG)s and attach those to the desiredANE.

4. Use BSC level parameters to define IBHO handling for anonymoussubscribers.

5. Enable IBHO functionality in cells where subscribers will have limitedhandover access to GSM or/and WCDMA network(s).

6. Define new adjacent cells which are located in other GSM or/andWCDMA network(s).

7. Verify IMSI-based handovers by using IBHO Measurements.

The activation is described in detail in Activating and Testing BSS12158:IMSI-based Handover.




Example

IBHO to GSM

The situation before IMSI-based handover configuration:

. The host operator has a GSM network.

. Cells that belong to other networks have not been defined asneighbour cells for the GSM network of the host operator.

. The host operator has roaming agreements with several inboundroaming operators.

. The subscribers of the host operator and the inbound roamingsubscribers only use the host operator's network.

The target situation:

. The host GSM operator wants its subscribers and inbound roamingsubscribers to use its GSM network (MCC = 856, MNC = 23) only.

. A GSM operator 'Greenfield1' wants its subscribers to use the hostoperator's GSM network whenever Greenfield1's own GSM network(MCC = 856, MNC = 78) is not available.

. A GSM operator 'Greenfield2' wants its subscribers to use the hostoperator's GSM network whenever Greenfield2's own GSM network(MCC = 856, MNC = 66) or Greenfield3's GSM network (MCC = 856,MNC = 90) is not available.

. A GSM operator 'Greenfield3' wants its subscribers to use the hostoperator's GSM network whenever Greenfield3's own GSM networkor Greenfield2's GSM network is not available.

The solution is to use IMSI-based Handover to GSM.

The IMSI-based Handover configuration:

. The host GSM operator creates an authorised networks (ANE) for itsnetwork:. authorised networks identification (ANE) = 1. network mobile country code 1 (MCC1) = 856. network mobile network code 1 (MNC1) = 23. network technology 1 (TECH1) = 0 (the technology is

GSM only)

. The host GSM operator creates an authorised networks (ANE) forthe operator Greenfield1's GSM network:


IMSI-based Handover

. authorised networks identification (ANE) = 2

. network mobile country code 1 (MCC1) = 856

. network mobile network code 1 (MNC1) = 78

. network technology 1 (TECH1) = 0 (the technology isGSM only)

. The host GSM operator creates an authorised networks (ANE) forthe operator Greenfield2's GSM network and the operatorGreenfield3's GSM network:. authorised networks identification (ANE) = 3. network mobile country code 1 (MCC1) = 856. network mobile network code 1 (MNC1) = 66. network technology 1 (TECH1) = 0 (the technology is

GSM only). network mobile country code 2 (MCC2) = 856. network mobile network code 2 (MNC2) = 90. network technology 2 (TECH2) = 0 (the technology is

GSM only)

. The host GSM operator's subscribers and inbound roamingsubscribers are directed to use the host operator's GSM networkonly:. IMSI based handover GSM cells anonymous MS (IBGA)

= 1 (Authorised networks '1' is used)

. The host GSM operator creates a subscriber group (SG) for GSMoperator Greenfield1's subscribers (the subscribers have SIM cardswithin MCC = 856 and MNC = 78):. subscriber group identification (SG) = 1. home mobile country code (HMCC) = 856. home mobile network code (HMNC) = 78. authorised networks identification (ANE) = 2

. The host GSM operator creates a subscriber group (SG) for GSMoperator Greenfield2's subscribers (the subscribers have SIM cardswithin MCC = 856 and MNC = 61):. subscriber group identification (SG) = 2. home mobile country code (HMCC) = 856. home mobile network code (HMNC) = 61. authorised networks identification (ANE) = 3

. The host GSM operator creates a subscriber group (SG) for GSMoperator Greenfield3's subscribers (the subscribers have SIM cardswithin MCC = 856 and MNC = 90):




. subscriber group identification (SG) = 3

. home mobile country code (HMCC) = 856

. home mobile network code (HMNC) = 90

. authorised networks identification (ANE) = 3

Note

. The host GSM operator has to enable the IMSI-based handover toGSM cell functionality in cells where subscribers will have limitedhandover access to GSM network(s). It can be done by settingparameter IMSI based handover GSM enabled (IGE) to value'Y'.

. The host GSM operator has to define neighbour cells from the GSMnetwork(s) of Greenfield operators.

. There is no need to create subscriber groups for inbound roamingsubscribers and host's subscribers.

. The BSC automatically adds GSM neighbours of serving PLMN toneighbour cell list. Therefore, the host GSM operator does not needto add a network identifier of its own GSM network to AuthorisedNetworks lists.

Example

IBHO to WCDMA: separate network identifiers for GSM and WCDMA


. The host operator has a GSM network and a WCDMA network.

. The host operator has defined neighbour cells from its own GSMnetwork and WCDMA network only.


. The subscribers of the host GSM operator use the host operator'sGSM and WCDMA network only.

. The inbound roaming subscribers use the host operator's GSMnetwork only.



IMSI-based Handover

. The host GSM operator wants its subscribers to use the hostoperator's GSM network (MCC = 856, MNC = 23) and WCDMAnetwork (MCC = 856, MNC 55) only.

. The host GSM operator wants the inbound roaming subscribers touse its GSM network only.

. A WCDMA operator 'Greenfield1' wants its subscribers to use thehost operator's GSM network whenever Greenfield1's own WCDMAnetwork (MCC = 856, MNC = 78) is not available.

. A WCDMA operator 'Greenfield2' wants its subscribers to use thehost operator's GSM network whenever Greenfield2's own WCDMAnetwork (MCC = 856, MNC = 66) or Greenfield3's WCDMA network(MCC = 856, MNC = 90) is not available.

. A WCDMA operator 'Greenfield3' wants its subscribers to use thehost operator's GSM network whenever Greenfield3's own WCDMAnetwork or Greenfield2's WCDMA network is not available.

The solution is to use IMSI-based HO to WCDMA.

The IMSI-based handover configuration:

. The host GSM operator creates an authorised networks (ANE) forthe host operator's GSM network:. authorised networks identification (ANE) = 1. network mobile country code 1 (MCC1) = 856. network mobile network code 1 (MNC1) = 23. network technology 1 (TECH1) = 0 (the technology is

GSM only)

. The host GSM operator creates an authorised networks (ANE) forthe host operator's WCDMA network:. authorised networks identification (ANE) = 2. network mobile country code 1 (MCC1) = 856. network mobile network code 1 (MNC1) = 55. network technology 1 (TECH1) = 1 (the technology is

WCDMA RAN only)

. The host GSM operator creates an authorised networks (ANE) forthe operator Greenfield1's WCDMA network:. authorised networks identification (ANE) = 3. network mobile country code 1 (MCC1) = 856. network mobile network code 1 (MNC1) = 78. network technology 1 (TECH1) = 1 (the technology is

WCDMA RAN only)




. The host GSM operator creates an authorised networks (ANE) forthe operator Greenfield2's WCDMA network and the operatorGreenfield3's WCDMA network:. authorised networks identification (ANE) = 4. network mobile country code 1 (MCC1) = 856. network mobile network code 1 (MNC1) = 66. network technology 1 (TECH1) = 1 (the technology is

WCDMA RAN only). network mobile country code 2 (MCC2) = 856. network mobile network code 2 (MNC2) = 90. network technology 2 (TECH2) = 1 (the technology is

WCDMA RAN only)

. The inbound roaming subscribers are directed to use the hostoperator's GSM network only:. IMSI based handover WCDMA cells anonymous MS

(IBWA) = 1 (Authorised networks '1' is used.)

. The host GSM operator creates a subscriber group (SG) for hostGSM operator's subscribers (the subscribers have SIM cards withinMCC = 856 and MNC = 23):. subscriber group identification (SG) = 1. home mobile country code (HMCC) = 856. home mobile network code (HMNC) = 23. authorised networks identification (ANE) = 2. WCDMA RAN access (WA) = Y (Yes)

. The host GSM operator creates a subscriber group (SG) forWCDMA operator Greenfield1's subscribers (the subscribers haveSIM cards within MCC = 856 and MNC = 78):. subscriber group identification (SG) = 2. home mobile country code (HMCC) = 856. home mobile network code (HMNC) = 78. authorised networks identification (ANE) = 3. WCDMA RAN access (WA) = Y (Yes)



IMSI-based Handover


Note

. The host GSM operator has to enable the IBHO to WCDMA cellfunctionality in cells where subscribers will have limited handoveraccess to WCDMA network(s). It can be done by setting parameterIMSI based handover WCDMA enabled (IWE) to value 'Y'.

. The host GSM operator has to define neighbour cells from theWCDMA network(s) of Greenfield operators.

. There is no need to create subscriber groups for inbound roamingsubscribers.

. The BSC automatically adds GSM neighbours of the host operator'snetwork to neighbour cell list. Therefore, the host GSM operatordoes not need to add the network identifier of its own GSM networkto Authorised Networks lists.

Example

IBHO to WCDMA: the same network identifiers for GSM and WCDMA


. The host operator has a GSM network and a WCDMA network .

. The host operator has defined neighbour cells from its GSM networkand WCDMA network only.





. The subscribers of the host GSM operator use only the hostoperator's GSM and WCDMA network.

. The inbound roaming subscribers use the host operator's GSMnetwork only.


. The host GSM operator wants its subscribers to use the hostoperator's GSM network (MCC = 856, MNC = 23) and WCDMAnetwork (MCC = 856, MNC 23) only.

. The host GSM operator wants the majority of the inbound roamingsubscribers to use the host operator's GSM and WCDMA networks.

. The host GSM operator wants the subscribers of inbound roamingoperators 'IR1' and 'IR2' to be handed over only inside the GSMnetwork of the host operator.

. The host GSM operator wants the subscribers of inbound roamingoperator IR-3 to be handed over to all networks from which cells aredefined as neighbours for GSM network of the host operator.

. A WCDMA operator 'Greenfield1' wants its subscribers to use thehost operator's GSM network whenever Greenfield1's own WCDMAnetwork (MCC = 856, MNC = 78) is not available.

. A WCDMA operator 'Greenfield2' wants its subscribers to use thehost operator's GSM network whenever Greenfield2's own WCDMAnetwork (MCC = 856, MNC = 66) or Greenfield3's WCDMA network(MCC = 856, MNC = 90) is not available.

. A WCDMA operator 'Greenfield3' wants its subscribers to use thehost operator's GSM network whenever Greenfield3's own WCDMAnetwork or Greenfield2's WCDMA network is not available.

The solution is to use IMSI-based HO to WCDMA.

The IMSI-based handover configuration:

. The host GSM operator creates an authorised networks (ANE) forthe host operator's GSM network and WCDMA network:. authorised networks identification (ANE) = 1. network mobile country code 1 (MCC1) = 856. network mobile network code 1 (MNC1) = 23. network technology 1 (TECH1) = 2 (the technology is

both GSM and WCDMA)


IMSI-based Handover

. The host GSM operator creates an authorised networks (ANE) forthe operator Greenfield1's WCDMA network:. authorised networks identification (ANE) = 2. network mobile country code 1 (MCC1) = 856. network mobile network code 1 (MNC1) = 78. network technology 1 (TECH1) = 1 (the technology is

WCDMA RAN only)

. The host GSM operator creates an authorised networks (ANE) forthe operator Greenfield2's WCDMA network and the operatorGreenfield3's WCDMA network:. authorised networks identification (ANE) = 3. network mobile country code 1 (MCC1) = 856. network mobile network code 1 (MNC1) = 66. network technology 1 (TECH1) = 1 (the technology is

WCDMA RAN only). network mobile country code 2 (MCC2) = 856. network mobile network code 2 (MNC2) = 90. network technology 2 (TECH2) = 1 (the technology is

WCDMA RAN only)

. The majority of the inbound roaming subscribers are directed to usethe host operator's GSM and WCDMA networks:. IMSI based handover WCDMA cells anonymous MS

(IBWA) = 1 (Authorised networks '1' is used.)

. The host GSM operator creates a subscriber group (SG) for hostGSM operator's subscribers. (The subscribers have SIM cardswithin MCC = 856 and MNC = 23.):. subscriber group identification (SG) = 1. home mobile country code (HMCC) = 856. home mobile network code (HMNC) = 23. authorised networks identification (ANE) = 1. WCDMA RAN access (WA) = Y (Yes)

. The host GSM operator creates a subscriber group (SG) forWCDMA operator Greenfield1's subscribers. (The subscribers haveSIM cards within MCC = 856 and MNC = 78):. subscriber group identification (SG) = 2. home mobile country code (HMCC) = 856. home mobile network code (HMNC) = 78. authorised networks identification (ANE) = 2. WCDMA RAN access (WA) = Y (Yes)





. The host GSM operator creates a subscriber group (SG) forWCDMA operator Greenfield3's subscribers. (The subscribers haveSIM cards within MCC = 856 and MNC = 90.):. subscriber group identification (SG) = 4. home mobile country code (HMCC) = 856. home mobile network code (HMNC) = 90. authorised networks identification (ANE) = 3. WCDMA RAN access (WA) = Y (Yes)

. The host GSM operator creates a subscriber group (SG) for inboundroaming operator IR1's subscribers. (The subscribers have SIMcards within MCC = 902 and MNC = 235.):. subscriber group identification (SG) = 5. home mobile country code (HMCC) = 902. home mobile network code (HMNC) = 235. authorised networks identification (ANE) = 1. WCDMA RAN access (WA) = N (No)

. The host GSM operator creates a subscriber group (SG) for inboundroaming operator IR2's subscribers (the subscribers have SIM cardswithin MCC = 858 and MNC = 30):. subscriber group identification (SG) = 6. home mobile country code (HMCC) = 858. home mobile network code (HMNC) = 30. authorised networks identification (ANE) = 1. WCDMA RAN access (WA) = N (No)

. The host GSM operator creates a subscriber group (SG) for inboundroaming operator IR3's subscribers (the subscribers have SIM cardswithin MCC = 907 and MNC = 34):. subscriber group identification (SG) = 7. home mobile country code (HMCC) = 907. home mobile network code (HMNC) = 34. authorised networks identification (ANE) = ND. WCDMA RAN access (WA) = Y (Yes)


IMSI-based Handover

Note

. The host GSM operator has to enable the the IBHO to WCDMA cellfunctionality in cells where subscribers will have limited handoveraccess to WCDMA network(s). It can be done by setting parameterIMSI based handover WCDMA enabled (IWE) to value 'Y'.

. The host GSM operator has to define neighbour cells from theWCDMA network(s) of Greenfield operators.

. There is no need to create subscriber groups for the majority ofinbound roaming subscribers.

. The BSC automatically adds GSM neighbours of the host operator'snetwork to neighbour cell list. Therefore, the host GSM operatordoes not need to add a network identifier of its own GSM network toAuthorised Networks lists.






IMSI-based Handover

5 Effects of IMSI-based Handover oninterfaces

The IMSI-based Handover has effects on the following interfaces:

Abis interface

There are changes to the following messages because of IBHO:

. SI_BEGIN

Indicates to the BTS, if the IMSI-based Handover is enabled.

. SACCH_INFO_MODIFY

The call-specific neighbour cell lists are sent in this message to theBTS.

. CHANNEL_ACTIVATION

The call-specific neighbour cell lists are sent in this message to theBTS.

A interface

The IMSI information element is always handled in the following messagesdue to IBHO:

. HANDOVER REQUEST

. COMMON ID

For more information, see 3GPP TS 48.008: Mobile-services SwitchingCentre - Base Station System (MSC - BSS) interface; Layer 3specification, version 4.8.0, Rel4.

Air interface

IBHO has no impact on the Air interface.



Effects of IMSI-based Handover on interfaces

Gb interface

IBHO has no impact on the Gb interface.



IMSI-based Handover

6 User interface of IMSI-based Handover

The IMSI-based Handover introduces parameters, counters, and MMLs.

Parameters

Base Station Controller (BSC) parameters

. IMSI based handover GSM cells anonymous ms (IBGA)

. IMSI based handover WCDMA cells anonymous ms (IBWA)

SEG-specific BTS radio network object parameters

. IMSI based handover GSM enabled (IGE)

. IMSI based handover WCDMA enabled (IWE)

Subscriber Group (SG) radio network object parameters

. subscriber group identification (SG)

. subscriber group name (NAME)

. home mobile country code (HMCC)

. home mobile network code (HMNC)

. authorised networks identification (ANE)

. WCDMA RAN access (WA)

Authorised Networks (ANE) radio network object parameters

. authorised networks identification (ANE)

. authorised networks name (NAME)

. network mobile country code 1 (MCC1)

. network mobile network code 1 (MNC1)



User interface of IMSI-based Handover

. network technology 1 (TECH1)
















For more information on parameters, see BSS Radio Network ParameterDictionary.

Alarms

IBHO has no impact on alarms.

Counters

IBHO introduces the IMSI-based Handover Measurement, which is a BTS/segment specific measurement. This measurement is optional and isvisible only when IMSI-based Handover in BSC application software isactive in the BSC. For information on the counters, see 104 IMSI-basedHandover Measurement.

IBHO also affects the BSC level clear code (PM) measurement. For moreinformation, see 51 BSC Level Clear Code (PM) Measurement.


IMSI-based Handover

MMLs

. Authorised Networks and Subscriber Group Handling (commandgroup E4)

. Base Station Controller Parameter Handling in BSC (commandgroup EE)

. Base Transceiver Station Handling in BSC (command group EQ )




User interface of IMSI-based Handover

Imsi Based Handover

Documents

Transcript of Imsi Based Handover