Location Registration

MSCDOCM14PDFCD MSC/HLR, Rel. M14.0, Product Documentation, v.3 Location Registration DN987572 Issue 10-0 en # Nokia Siemens Networks 1 (53) Location Registration 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 Siemens 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 Siemens 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 Siemens Networks welcomes customer comments as part of the process of continuous development and improvement of the documentation. 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All rights reserved. 2 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en Contents Contents Contents 3 List of tables 4 List of figures 5 Summary of changes 7 1 1.1 1.2 1.2.1 1.2.2 1.2.3 1.2.4 1.2.5 1.2.6 1.3 1.4 1.5 1.6 2 2.1 2.1.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 Location Registration 9 Functional properties of location registration 9 Location registration procedures 13 Intra-MSC/VLR location update 16 Inter-MSC/VLR location update 17 Inter-PLMN location update 19 Location update in the HLR 20 Periodic location update 20 IMSI attach 21 Not-reachable MS 21 Location registration-related data in the VLR 22 Location registration-related data in the HLR 26 Location registration-related mobility measurements and charging Location registration-related features 31 National roaming 31 Location updating 32 GSM restoration 33 Subscription-based network access 35 IN mobility management 38 Regional roaming 42 Network identity and time zone 46 Inter-system handover and UMTS changes in the MSC Support of interaction with SGSN in MSC/VLR 51 Location update in pool area concept 52 29 47 DN987572 Issue 10-0 en # Nokia Siemens Networks 3 (53) Location Registration List of tables Table 1. Zone codes in MSC/VLR 44 4 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en List of figures List of figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Network elements and interfaces involved in location registration in GSM and UMTS networks 10 Service blocks involved in location registration in the MSC/VLR Service blocks involved in location registration in the HLR UMTS Service Area GSM Cells 14 16 18 34 14 13 12 Location update Inter-MSC/VLR location update VLR restoration in GSM Phase 2 Overview of the feature 36 Figure 10. IN mobility management architecture Figure 11. Handover support 50 40 DN987572 Issue 10-0 en # Nokia Siemens Networks 5 (53) Location Registration 6 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . Summary of changes Summary of changes Changes between document issues are cumulative. Changes made between issues 9–2 and 9–1 No changes in content. DN987572 Issue 10-0 en # Nokia Siemens Networks 7 (53) . Inter-system handover and UMTS changes in the MSC Access control optimisation for partial 2G/3G roaming agreement scenarios has been added. only editorial corrections done. Support of interaction with SGSN in MSC/VLR MS Identity Reguest and alternative CS paging has been added to the Gs interface procedures. Therefore. Regional roaming Early regional roaming checking based on PLMN default zone codes to save VLR-HLR/AUC signalling load has been added. Changes made between issues 10–0 and 9–2 Inter-MSC/VLR location update Support of MAP SendIdentification between PLMNs has been added. Location update in pool area concept Section has been added to the document. the latest document issue contains all changes made to previous issues. MAP enquiry: retrieving subscriber data from the previous MSC/VLR Topic moved from Section Location update in the HLR to Section InterMSC/VLR location update. Subscriber parameters Section updated. 8 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . VLR reset Figure VLR restoration in GSM Phase 2 updated.Location Registration Changes made between issues 9–1 and 9–0 Location registration procedures Parameters for allowing and denying location updates between a GSM and a UMTS network removed. There are two types of location registers: . This description covers circuit-switched side location registration. the PLMN keeps track of the location of the mobile station. In order to be able to route incoming calls.1 Functional properties of location registration Interfaces and protocols The interfaces in the NSS are presented in the following figure. the HLR. 1. which contains permanent subscriber information and the address of the current VLR of the subscriber if it is known the VLR. Interface B between the MSC and the VLR is an internal interface. Location information is stored in functional units called location registers. which are needed in the location update of a GSM or UMTS subscriber in the GSM or UMTS network.Location Registration 1 Location Registration The Location Registration function class includes the functions in the MSC/VLR and the HLR. where subscriber data is stored as long as the MS is within the area controlled by that particular VLR . DN987572 Issue 10-0 en # Nokia Siemens Networks 9 (53) . checking of the equipment identity. TCAP. Interaction with other functions and function groups Location registration procedures interact with roaming checking (national and regional).Location Registration MS BSS A UTRAN Iu cs R99 MGW A‘ A BSS MSC B VLR MS G D HLR AUC MGW Mc F EIR Iu cs UTRAN MS MS VLR B MSC Figure 1. MAP. collection of traffic data. ciphering and integrity protection. The BSSAP replaces the MAP and TCAP in the protocol stack in signalling over the A-interface (MSC/VLR–BSS). re-allocation of the temporary mobile subscriber identity. as well as with possible IN applications. Network elements and interfaces involved in location registration in GSM and UMTS networks The network elements use the CCS. authentication. Location registration procedures are as follows: 10 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . and SCCP over MTP protocol stacks for signalling with each other. AIASEB The A-Interface Applications Service Block implements the BSSAP. . MOSSEB The General Mobile System Service Block provides routing analysis for the IMSI. . . IMSI attach/detach in the MSC/VLR normal and periodic location updating in the MSC/VLR retrieval of subscriber identity and authentication vectors from the previous MSC/VLR location updating in the HLR . DN987572 Issue 10-0 en # Nokia Siemens Networks 11 (53) . . CELSEB The Cellular Network Service Block provides cellular network management. MATSEB The Mobile Application Part Service Block implements the MAP. . Architecture The following service blocks take part in the implementation of location registration: . subscriber data retrieval from the HLR . . CNGSEB The Charging Service Block provides charging services. location cancellation in the MSC/VLR . HLRSEB The Home Location Register Service Block includes the HLR database and HLR application. AUCSEB The Authentication Centre Service Block provides authentication services. EIRSEB The Equipment Identity Register Service Block provides IMEI checking services.Location Registration . . . . and TCAP implementation. . . The following figures represent the service blocks in the MSC/VLR and the HLR. MTPSEB The Message Transfer Part Service Block contains the MTP. TRDSEB The Traffic Administration Service Block contains traffic administration services. VLRSEB The Visitor Location Register Service Block includes the VLR database and VLR application.Location Registration . MSC/VLR MOSSEB TRDSEB CELSEB VLRSEB CNGSEB AIASEB MATSEB BSSAP MTPSEB MAP Figure 2. SCCP. Service blocks involved in location registration in the MSC/VLR 12 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . 2 Location registration procedures Location registration enables the GSM or UMTS network to locate the mobile subscribers in its own area and to route mobile-terminated calls efficiently. Service blocks involved in location registration in the HLR 1.Location Registration HLR CNGSEB TRDSEB AUCSEB HLRSEB EIRSEB MATSEB MTPSEB MAP Figure 3. DN987572 Issue 10-0 en # Nokia Siemens Networks 13 (53) . UMTS Service Area Location Area (LAI) Cell (CGI) Figure 5.Location Registration Location Area (LAI) Service Area (SAI) Figure 4. GSM Cells 14 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . The BSS is further divided into location areas.Location Registration The GSM network is divided into an NSS and a BSS. and compares the LAI number to the one in its memory. The LAI number. One or more cells form a service area. and one or more service areas make a location area. a UMTS core network uses the SAI. which is the equivalent to a BSS in a GSM network. there is a UTRAN. DN987572 Issue 10-0 en # Nokia Siemens Networks 15 (53) . The location information of a mobile subscriber is stored in the MSC/VLR and in the HLR. and the MSC/VLR in turn informs the mobile subscriber's HLR that the mobile station is now in its area. the MS initiates a location updating in which the MS informs the core network about its old location area and the BSC/RNC provides the core network with the new location area of the MS. The MS keeps listening to the signal from the base station. The following figure gives an overview of the procedure. If the LAI numbers do not match. which the base stations broadcast continuously. In a UMTS network. The MS informs the MSC/VLR about its own location area. Every cell has a unique CGI number. Instead of the CGI. is stored in the memory of the MS. which identifies the service area. which consist of several cells. where the mobile station resides. only the location information in the VLR needs to be updated. Location update When an MS changes its location area but remains under the control of the same MSC/VLR.2. the information in the HLR also needs to be updated.Location Registration MS BSS MSC/VLR AUC/HLR Location Update Request Request Subscriber Id . but remains in the same MSC/VLR. 16 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . As soon as this is done.1 Intra-MSC/VLR location update In an intra-MSC/VLR location update. an IMSI attach/detach is performed. When the MS is turned on/off within the same location area. The mobile status (attached/detached) is then updated in the VLR. 1. Security checkings HLR Update Insert Subscriber Data Ack HLR Update Ack Location Update Ack Figure 6. the HLR cancels the subscriber's data from the previous VLR. When an MS changes its location area so that it moves to the control area of another MSC/VLR. Send Own Id. the mobile subscriber changes the location area. the mobile subscriber changes both his location area and the MSC/VLR area. and the network may allocate a new TMSI for the subscriber. to which the MS answers by sending an (S)RES. The BSC/RNC provides the CGI/SAI to the MSC/VLR.2. 1. The network may also ask for the IMEI of the MS. The network may respond with an authentication request. This may be followed by an IMEI checking towards the EIR.2 Inter-MSC/VLR location update In an inter-MSC/VLR location update. but remains in the same PLMN.Location Registration The MS initiates the location update procedure by sending its TMSI or IMSI and old location area identity to the network. Ciphering and integrity protection on the radio interface may be started. Location updating must also be done in the HLR because the subscriber is not registered in the new VLR. The following figure gives an overall picture of an inter-MSC/VLR location update: DN987572 Issue 10-0 en # Nokia Siemens Networks 17 (53) . The MSC recognises the old LAI as the LAI of another VLR area. The subscriber's IMSI is requested from the old VLR. 18 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . This is done in a MAP enquiry. and an IMSI analysis is performed in order to find out the HLR address of the mobile station. The BSC/RNC also sends the new CGI/SAI to the core network. the IMSI and the authentication triplets/quintets must be fetched from the old VLR. Since the mobile subscriber is unknown to the new VLR.Location Registration MS BSS MSC/VLRnew MSC/VLRold AUC/HLR Channel Assignment Location Update Request Request Subscriber Identity Provide Subscriber Identity Security checkings HLR Update Insert Subscriber Data Ack HLR Update Ack Location Update Ack Cancel Old Location Location Cancelling Accepted Figure 7. Inter-MSC/VLR location update The MS starts the location update by sending its TMSI and the old LAI to the MSC/VLR. which is useful when the VLR serves more than one home PLMNs (for example. If the MSC/VLR is not able to identify the mobile subscriber on the basis of the TMSI. and a new TMSI is allocated to the mobile station. If new authentication sets are needed during location registration.3 Inter-PLMN location update In an inter-PLMN location update.2. The new location of the MS is stored in the HLR. the required subscriber information is received from the HLR. The mobile station sends a normal location updating request with TMSI or IMSI and the old LAI to the MSC/VLR. 1. the HLR initiates a 'cancel location' procedure towards the old VLR. This functionality can be activated between different PLMNs as well. The IMSI is obtained by interrogating the previous VLR if the two MSC/VLRs are within the same PLMN. they are requested by a 'send authentication info' option before the location update message is sent to the HLR. The authentication sets are also sent if they are requested and they are available. the mobile subscriber enters another mobile network. DN987572 Issue 10-0 en # Nokia Siemens Networks 19 (53) . the IMSI is requested from the MS itself. The MSC recognises the old LAI as the LAI of another PLMN.Location Registration The next step in the location update procedure involves sending the IMSI and the address information to the HLR. the location update is acknowledged to the VLR. In response to the interrogation. As soon as the location updating is completed in the HLR. 2G and 3G networks are defined as two PLMNs). the new VLR must obtain the IMSI of the MS before the HLR can be updated. In response to this. When a mobile station roams from one VLR area to another with a TMSI allocated to it by the previous VLR. MAP enquiry: retrieving subscriber data from the previous MSC/VLR A MAP enquiry is made to obtain information of a mobile subscriber from another MSC/VLR. the VLR sends the IMSI of the MS to the new VLR. Location updating must be done in the HLR. the network requires the mobile station to 'report in' at certain time intervals.Location Registration The IMSI is analysed to obtain the HLR address. The cancel location procedure can also be initiated with MML commands. so when a mobile station enters the VLR area. and a request for authentication triplets/quintets may be sent to the AUC. the HLR responds by sending the subscriber information to the VLR. 1. or deleting the MS from the HLR.2. When the data is sent. it automatically knows how often it has to report to the network. and incoming calls to the MS are not paged. the MS initiates a periodic location update. for example. Every time location updating occurs. the subscriber's data is deleted from the previous VLR in a cancel location procedure. 1.5 Periodic location update Periodic location updating is used to inform the network that the mobile station is available. the network assumes that the MS is out of the coverage area or that it has not been turned on. The time-out value is continuously broadcast. that are used for changing the area. The time interval for periodic location updating is defined in the base station parameters. This saves radio resources. the MS and the VLR reset their timers. after which an IMEI checking may happen towards the EIR. ciphering and integrity protection on the radio interface may be started. with those. Location cancellation When a mobile station registers in a new VLR. 20 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en .2. When the timer of the MS reaches the timeout value. Location updating in the HLR is followed by a 'cancel location' procedure in the previous VLR.4 Location update in the HLR In the HLR location update. the mobile subscriber's IMSI together with the MSC and VLR ISDN numbers are sent to the HLR. If there are no messages from the mobile station. and the network may allocate a new TMSI to the mobile subscriber. The HLR initiates the procedure when it receives an 'update location' message from a VLR other than the one in which the MS was located at the time when its location information was last updated in the HLR database. the new location of the MS is stored in the HLR and the location update is acknowledged to the VLR. Then the network may also ask for the IMEI of the MS. If the subscriber is allowed to roam in the area. As a result. The IMSI detach information is stored in the VLR.6 IMSI attach IMSI attach is an operation in which the MS becomes active (for example. when the mobile station has powered up). such as after a VLR restart. the VLR removes the IMSI detach flag and resumes normal call handling for the MS. the update from the HLR is done in certain error conditions. The use of the IMSI attach operation is defined in the base station parameters.3 Not-reachable MS The following location management procedures can result in the fact that an MS becomes not reachable: . The use of the IMSI detach operation is defined in the base station parameters.2. IMSI detach A regular IMSI detach operation is an action by which an MS informs the PLMN that it has become inactive (for example. However.Location Registration In a periodic location update. and the HLR does not need to be updated. and location updating in the HLR is not needed. the MS has powered down). In this procedure. A regular IMSI detach has occurred. On the basis of this information. or a VLR cleaning. 1. . calls coming to the MS can be rejected without sending a paging message on the radio path. 1. An implicit IMSI detach has occurred. A 'Purge MS' has occurred. DN987572 Issue 10-0 en # Nokia Siemens Networks 21 (53) . . the VLR area does not change. The IMSI attach information is stored in the VLR. A detach flag is set after the IMSI detach has been completed. The use of the feature is defined in the USE OF IMPLICIT IMSI DETACH parameter (VLR). the VLR compares the last active date and the time limit defined for the IMSI detach. The implicit IMSI detach is an optional feature in the network. Purge MS A 'purge MS' is a request by which the VLR orders the HLR to delete the mobile station's VLR address. the VLR subscriber database contains the following data needed for location registration functions: . If the IMSI is in 'detach' state (because of the IMSI detach or implicit IMSI detach procedure). MAY LOITER BEFORE BEING DELETED FROM VLR. cell global identity/service area identity mobility management location area identity . 1. the incoming call establishment is interrupted. The time must be longer than the periodic location updating time (defined in the BSC). 22 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en .Location Registration Implicit IMSI detach An implicit IMSI detach operation is an action taken by the VLR when the MS has been inactive for too long a time. so that any request for routing information for a mobile-terminated call will be treated as if the MS was not reachable. The implicit IMSI detach operation may also be activated by the operator. The operator can initiate this procedure with an MML command. The procedure is initiated by an MT event: when a call or a short message comes in. The cleaning parameters in the VLR are VLR CLEANING START TIME and TIME SUBSC. but it is also initiated if the MS has been inactive for too long (a VLR cleaning is performed).4 Location registration-related data in the VLR Subscriber parameters For every subscriber registered in the VLR. but shorter than the loitering time. The time limit is defined in the IMPLICIT IMSI DETACH TIME LIMIT parameter (VLR). The time limit is defined in the VLR parameters. this way an unnecessary circuit establishment from the gateway to the MSC/VLR and paging are avoided. the IMSI detach flag is set on. If the time limit has been exceeded. but the subscriber data is not deleted from the VLR. If the MS initiates a CS call in the meantime. the SAI (real location) can be different from the MM LAI (the one under the serving RNC). DN987572 Issue 10-0 en # Nokia Siemens Networks 23 (53) . location update IMSI attach IMSI detach mobile-originated call mobile-originated SM mobile-originated supplementary service operation . while it needs the SAI for routing and positioning purposes. The mobility management location is the LAI where the MS made the latest location update. however. This includes the following: . the CGI and MM LAI contain the same LAI. The VLR updates the CGI/SAI after every operation performed by the MS. . . . in general. . The serving RNC remains the same during the PS session even if the MS moves to another location or VLR area. The cell global identity/service area identity shows the exact location of an MS within the PLMN. . . . . In UMTS. . The MSC decides whether the MM LAI can be sent to the VLR. the MM LAI and the LAI part of the CGI/SAI are the same. . in UMTS. The VLR uses the MM LAI in the paging procedure. This is always true during location registration procedures and in GSM radio access. In GSM. the MSC sends the MM LAI to the VLR only if it is received from the MGW. This can happen when the user moves during an active PS session. the SAI can refer to a LAI other than the MM LAI. The VLR updates the MM LAI if it is received from the MSC and contains a valid LAI. During a location update procedure. IMSI detach flag IMEI (with software version) IMEI status authentication information last active date HLR address SGSN address zone code list .Location Registration . The address is used in subsequent procedures towards the HLR. In this case. or a supplementary service operation). the VLR application starts a search procedure. All location data is lost at the VLR restart. The IMSI detach flag is updated after each location registration procedure. The operator can handle the subscriber data in the VLR with the commands of the Visiting Subscriber Identification Handling (MV) command group. When the search has been successfully completed. or a supplementary service operation). The zone code list represents those zones (that is. location updating. The SGSN index is not zero if the MS is GPRS-attached. For more information. location updating. response to paging after call release if the call lasted longer than 3 minutes . the new MM LAI is updated in the VLR database. The HLR address is fetched from the HLR during the location updating procedure. the SGSN notifies the VLR about the location area changes. see Regional roaming. the VLR application rejects the call. For more information. The last active date (time stamp) is updated after every procedure which indicates that the mobile station is in an active state (for example. see Support of interaction with SGSN in MSC/VLR. If there is an incoming call to a subscriber who is in an 'IMSI detached' state. a call.Location Registration . for example). or when it responds to the search procedure during an incoming call set-up. a call. and the VLR initiates the paging procedure through the SGSN. if necessary. IMSI analysis The IMSI number analysis service enables the operator to route the following requests to the correct HLR: 24 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . if available. If there is an incoming call to a subscriber whose mobility management location area is unknown (after a VLR reset. The network updates the location automatically when the mobile station is active (for example. group of location areas) where the user is allowed to roam. The IMSI analysis enables the VLR to find an address for contacting the subscriber's HLR. the HLR sends a more specific HLR address. The parameters are handled with the commands of the VLR and PLMN Parameter Handling (MX) command group. . which makes it impossible to trace a subscriber by listening to the radio path integrity protection (UMTS only) . The parameters are divided into PLMN-specific and VLR-specific parameters. which means that roaming is not allowed. Security The system provides the following security functions: . HLR and VLR. DN987572 Issue 10-0 en # Nokia Siemens Networks 25 (53) . The VLR-specific parameters are independent of the subscriber's HPLMN. VLR parameters VLR parameters are used to control certain functions in the VLR. The operator can change and output the values of the parameters. ciphering. After the first contact. The PLMN-specific parameters control those VLR functions which depend on the subscriber's HPLMN. . which ensures a secure transmission on the radio path TMSI. see Parameter Management in EIR. .Location Registration . The IMSI numbers that cannot be analysed are blocked by default. a request from a new mobile subscriber for location updating a request for authentication triplets/quintets for a new mobile subscriber a 'restore data' request if subscriber data is lost in the VLR and there is an incoming call to the subscriber a request for GSM restoration towards the HLR .and PLMN-specific parameters. and this is stored in the VLR subscriber database. For more information on the VLR. . Subscriber data in the HLR can be handled with the MML commands of the Home Subscriber Identification Handling (MI) command group. see Security management in AuC. If none of the subscriber basic services can be used in the VPLMN. the location registration is denied by the HLR. For more information on security-related issues. The service area is given to the subscriber when it is created in the HLR database.5 Location registration-related data in the HLR Subscriber parameters The HLR database provides three information elements for location registration functions: . 1. mutual authentication. They are handled with the MML commands of the HLR and PLMN Parameter Handling (MJ) command group. 26 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . HLR parameters HLR parameters are used to control certain functional properties in the HLR.Location Registration . which prevents unauthorised access to the network. but the operator can change it with MML commands. the addresses of the MSC and the VLR in the area where the MS is currently located information about the service area of the MS information about how wide area the MS is allowed to roam in in the network . Another purpose of the IMEI checking is to guarantee that only the type-approved mobile equipments can use the network. EIR and VLR and Parameter management in EIR. HLR and VLR. . which is made to guarantee that the equipment is used only by its rightful owner. UMTS subscribers can also authorise the network (a UMTS subscriber is a subscriber having a UMTS SIM card) IMEI checking. The addresses are received in the location updating request. Location Registration The parameters can be divided into HLR-specific and PLMN-specific parameters. This is a key parameter. The parameter can be as specific as necessary to enable the managing of the country PLMN parameters and even VLR-specific parameters. This section describes the use of the HLR parameters in location updating procedures. PLMN description A PLMN is specified in one of the following parameters: . for example. the abbreviation 'PLMN' appearing in brackets after the parameter name means that the parameter is PLMN-specific. The PLMN INDEX parameter is the index of the PLMN entry. used for searching the PLMN-specific parameters in the file. The names of the parameters are written in capital letters. . indicates an HLR-specific parameter. Mobility management in location registration Update location When the HLR receives an 'update location' message from the current VLR of the subscriber. Both HPLMN and VPLMN defaults are available in the PLMN-specific file. a VLR-specific parameter can be used to screen the sending of data to the VLR associated with the new function. it is created automatically in connection with a new PLMN entry. If a VLR of an older release does not support certain functions in an HLR upgrading. the operator has to decide whether it gets VPLMN or HPLMN defaults as its initial values. the abbreviation 'HLR'. The HLR-specific parameters are general parameters of the HLR: they are independent. in turn. When a new entry is defined. PLMN NAME (PLMN) PLMN INDEX (PLMN) PLMN COUNTRY AND NETWORK CODES . The PLMN COUNTRY AND NETWORK CODES parameter defines the PLMN (or VLR) of the entry. the HLR checks whether the subscriber has a service defined in the ROAMING NOT ALLOWED FOR SUBSCRIBER WITH CERTAIN SERVICES (PLMN) parameter. The point of view is functional: the parameters are described as means of controlling certain functions. The PLMN-specific parameters control those HLR functions which depend on the PLMN (in some cases also on the VLR) in which the subscriber is roaming. If the subscriber has this kind of DN987572 Issue 10-0 en # Nokia Siemens Networks 27 (53) . of the PLMN. informing them that the MS is reachable. Also. If all basic services of a subscriber belong to forbidden services. Note that even if the parameter was VLR-specific. The area can be one of the following: ALL OWN NAT INT the whole GSM network the own national network all national networks the own national network and all international networks Insert subscriber data The MAP level and version needed in the 'insert subscriber data' operation are defined in the MAP LEVEL (PLMN) and MAP VERSION (PLMN) parameters. 28 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . Because the MS may need time to get into a state in which it can receive short messages. The principle of the basic services is the same: the services defined in the NOT ALLOWED BASIC SERVICE (PLMN) parameter as forbidden are not sent to the VLR in the 'insert subscriber data' operation. the HLR prevents access to the network by sending a negative acknowledgement and the error code 'roaming not allowed'. If the 'update location' operation succeeds and there are short messages waiting for the MS in the SMSC. and the 'roaming not allowed' error code is generated. When the mobile station receives the error code. and the VLR address is defined as 'unknown' in the HLR. The subscriber's VLR and MSC addresses are defined as 'unknown' in the HLR. The networks are specified in the SERVICE AREA OF PRIMARY MSISDN parameter in the MIC command. the HLR alerts the SMSCs. The networks from which a subscriber is allowed to make location updates can be specified when creating subscriber data in the HLR. Note that the responsibility for the use of this parameter is the operator's. 'cancel location' is sent to the old VLR. 'update location' is negatively acknowledged. Those supplementary services which must not be transferred to the VLR are screened out from the 'insert subscriber data' message in the NOT ALLOWED SUPPLEMENTARY SERVICE (PLMN) parameter. the access to the whole PLMN is denied because of the error code. it does not try to gain access to the network again. the operator can delay the sending of the alert message with the DELAY OF SENDING ALERTS parameter. The service interactions are not checked in the HLR.Location Registration a service. location updates of the home subscribers within the VLR area location updates of the home subscribers within the VLR area between HPLMNs location updates of the home subscribers from one VLR area to another within one PLMN location updates of the roaming subscribers within the VLR area location updates of the roaming subscribers within the VLR area between HPLMNs location updates of the roaming subscribers from one VLR area to another periodic location updates IMSI attach IMSI detach arriving visitors departing visitors GPRS initiated location updates registered subscribers per LA registered home subscribers per HLR address registered roaming subscribers per PLMN name . The same counters are implemented for normal and telemetric subscribers. . .6 Location registration-related mobility measurements and charging The user can handle location registration-related mobility measurements with the MML commands of the GSM Measurement Handling (TP) command group. . . 1. . . Mobility measurements and charging in the VLR In the VLR. . DN987572 Issue 10-0 en # Nokia Siemens Networks 29 (53) . . there are counters implemented for the following: . . . . .Location Registration Note that since the service interactions are not checked in the HLR. . the responsibility for the use of this parameter is the operator's. Mobility measurements in the HLR In the HLR. . location updates of the home subscribers to other PLMNs location updates of the home subscribers from another PLMN back to the HPLMN the total number of location updates of home subscribers registered subscribers in each VLR GPRS location registration registered subscribers per SGSN . for example. when the MSC or CGI/SAI changes.Location Registration Charging records of location updates can be created in the VLR. . . The amount of charging data decreases when unnecessary toll tickets (such as those caused by periodic location updates) are not used. . 30 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . there are counters implemented for the following: . A charging record can also be created during a location update. The main functional property of national roaming in the network subsystem is that it can prevent location updates in certain areas (groups of location areas) of subscribers from other networks. This means that if this feature is used. National roaming allows the operator to differentiate in a certain national network between areas where roaming from neighbouring networks is allowed and where it is denied. This feature is based on LA information. the normal condition is not allowed. which defines whether subscribers from other national networks are allowed to roam into a particular location area. while allowing it in other parts of the network. and others where it is restricted.Location registration-related features 2 2. If the subscriber of another network is explicitly allowed to roam in a particular location area. location updating is accepted. The basic assumption is that when a subscriber roams from the same country but from another network. 'national roaming allowed'. the cause is 'national roaming restricted'. the default setting concerning a case that restricts roaming. More detailed information can be found in the descriptions of the respective features.1 Location registration-related features Features that are affected by or have an effect on location registration are presented briefly below. with automatic return to the HPLMN when this is possible. DN987572 Issue 10-0 en # Nokia Siemens Networks 31 (53) . National roaming National roaming is a service which enables a mobile station of a given PLMN to obtain services from another PLMN in the same country on a location area basis. Operators in the same country can define areas where roaming between their networks is allowed. a national roaming check is made. for phase 2 mobile stations the error code is 'Roaming not allowed in this location area'. The national roaming restriction is signalled to phase 1 mobile stations in a 'location area not allowed' error code. Feature description. 2. 32 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . location updating is accepted. If the location updating is rejected and the error code is 'Roaming not allowed'. The GSM Phase 1 specification does not include national roaming definitions. some of the mobile stations supporting the phase 1 specification may behave in an unpredictable way. If the mobile station's PLMN information has been defined as 'home country and visitor PLMN'.Location Registration For more information on national roaming.1. checking the function of phase 1 mobile stations in this respect is recommended before the feature is activated. location areas have information of MNC and of the national networks from which roaming is allowed. If the MNC has been defined for the location area in question. Note Because the error code 'location area not allowed' is not intended to be used in this context. The specification phase of a mobile station is indicated in the revision level field of the MS classmark. It cannot be guaranteed that this feature functions in GSM Phase 1 mobile stations. see Feature 124: National Roaming. For this purpose. If the MNC defined for a particular location area does not correspond to the MNC in the IMSI. the MS starts the initial access procedure. The national roaming restriction indication to the mobile station depends on what GSM specification the MS supports.1 Location updating National roaming conditions are checked at location updating. Therefore. location updating is rejected because of the national roaming restriction. 2 GSM restoration The GSM restoration feature includes the procedures needed for ensuring the integrity of data in the location registers after the reset of the whole network element. This is replaced with a 'restore data' operation. In this case.Location registration-related features The handling of user information in the network depends on what the update status of the subscriber in the VLR was at the moment when the location updating of the MS was rejected. Mobile subscriber not known to the VLR The user information is not obtained from the HLR. DN987572 Issue 10-0 en # Nokia Siemens Networks 33 (53) . 2. When the 'provide roaming number' request concerns an unidentified subscriber. and the national roaming restriction is effective. the VLR no longer sends the 'send parameters' request like in MAP Phase 1. The operation is very similar to a location update operation. Feature Description. national roaming was allowed at the time when the previous location updating occurred. VLR reset When the VLR is restarted. the user status in the VLR is defined so that the originated attempts are not allowed. all data in the subscriber database of the VLR is lost. Later. Restoration procedures are defined for the HLR and the VLR. roaming is not allowed any more. Mobile subscriber known to the VLR In this case. After the VLR is restarted. when location updating is attempted again. see Feature 226: GSM Restoration. the data is received from the HLR in the normal location registration procedure. For more information on GSM restoration. it functions normally: the same way in which it functions when the subscriber is not identified in the VLR. In case of location update or IMSI attach. Send_Routing_Info_Ack (MSRN) 7.Location Registration GMSC VMSC HLR MS 1. the VLR notifies the HLR and downloads the subscriber's data if the IMPLICIT_LOC_UP system configuration parameter is active. The network starts the restoration procedures automatically after the reset of the VLR. Restore_Data_Ack 5. The HLR handles the 'send parameters' and the 'update location' requests normally. If the implicit location update feature is not active. Page MS Normal Call Completion Figure 8. Provide_Roaming_Number_Ack (MSRN) 6. IAM 8. Send_Routing_Information 2. This makes the MS initiate the location registration request. Restore_Data Subscriber Data Transfer 4. Provide_Roaming_Number 3. the VLR performs an implicit location update. the VLR returns the 'unidentified subscriber' error code. 34 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . and informs all VLRs involved by sending them a 'reset' message. VLR restoration in GSM Phase 2 If the subscriber tries to originate a call or makes a supplementary service control request. that is. the HLR reloads all data from the back-up. Then the original operation continues normally. HLR reset After the reset of the HLR. is checked from the HLR. Information about the possible loss of data is transferred to the VLR in reply to the location registration request. it sets a reset indicator concerning all the subscribers of that particular HLR. The VLR sends it to the MSC at call establishment. When the subscriber tries to register in a VLR for the first time. The feature is based on roaming profiles defined by the operator. and the MSC forwards it to the MS. If the VLR has been defined as 'not allowed' in the subscriber's roaming profile. which indicate whether the consistency of subscriber data has been confirmed. but in a more efficient way by using reset counters. The indication of the confirmation is not implemented as special parameters in the subscriber data. and the subscriber cannot roam in that particular VLR area. The location registration is initiated if the reset occurred after the previous location registration of the subscriber. DN987572 Issue 10-0 en # Nokia Siemens Networks 35 (53) .Location registration-related features To prevent the loss of supplementary service information at the restart. the subscribers's roaming profile . 2. The indicator is checked every time a subscriber originates a call or makes a supplementary service control operation. When the VLR receives the reset message from the HLR. the registration is rejected. The maximum number of different profiles is 99. an 'SS check required' indication is set in the HLR. The functional properties are the same. The network starts the restoration procedures automatically after the reset of the HLR. The consistency of data between the HLR and the VLR cannot be guaranteed in all cases if administrative commands are given during the restoration procedure. Each subscriber can be associated with one profile. Restrictions The GSM specification introduces parameters called restoration indicators.3 Subscription-based network access Subscription-based network access is a feature which enables the operator to prevent or allow roaming in certain VLR areas.if the subscriber has one . .. the VLR in this context can be considered as a 'VLR' in the SGSN.. 99 Negative Response Not Allowed ..Location Registration This feature also applies to the GPRS network. see Feature 541: Subscription-Based Network Access.. Properties HLR Location Update Request IMSI VLR Address Subscriber Data VLR Address Analysis RP Index PLMN Index Roaming Profile Analysis PLMN 0 RP 1 allowed PLMN 1 not allowed allowed . Feature description. that is. Allowed Continue Normally Figure 9. .. Feature description and Feature 857: Support of General Packet Radio Service. Overview of the feature 36 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . the VLR address being the SGSN address. For more information on subscription-based network access...1499 RP 2 not allowed . each PLMN index has a status. which consists of 99 different roaming profiles. The roaming profile analysis is based on a roaming profile table. After the deactivation.' If the result of the roaming profile analysis is 'allowed. and updated if necessary. When the operator defines a roaming profile index for a subscriber. which is either 'allowed' or 'not allowed. is analysed to get a PLMN index. the roaming profile is not analysed. A profile is based on PLMN indexes. a roaming profile analysis is performed in the HLR. received in the location update request. If the parameter prevents roaming. For example. however. the settings for that PLMN index in all roaming profiles must always be checked. The operator can decide what error code is generated at the refusal: it can be either 'roaming not allowed' (this is the default) or 'unknown subscriber. The roaming profile analysis can be made when both the roaming profile index and the PLMN index are known. if the operator wants the roaming profile to allow roaming in the VLR(s) of just one particular VLR address analysis branch. Changes in the roaming profile table do not initiate the cancel location procedure. If the result of the analysis is 'not allowed'. If the checking of the roaming profile status fails. In every roaming profile. When new branches are created (new indexes are taken into use). all VLRs are considered 'allowed'. DN987572 Issue 10-0 en # Nokia Siemens Networks 37 (53) . The VLR address. all PLMN indexes in the roaming profile except for one are defined as 'not allowed'.' the location update continues in the normal way. the location update is refused. When creating a new branch to a VLR address analysis. The operator can define a status for indexes which have not yet been allocated to a VLR address analysis branch. the new VLR initiates a location update towards the HLR. no roaming profile analysis is made even if there are associations with the roaming profile in the subscriber data. The operator can deactivate the feature with an MML. roaming is allowed. they automatically obtain the same status. The service area of the subscriber is analysed before the roaming profile.Location registration-related features When an MS roams in a new VLR area.' The roaming profile analysis is very flexible because there is no check between it and the VLR address analysis. If the network operator has given a roaming profile index to the subscriber. They are allocated to all branches in a VLR address analysis. the cancel location procedure towards the present VLR is initiated. on the basis of the location of the subscriber. the new location is not updated in the HLR until the subscriber has finished the call. at which the control of the location registration procedure can be moved to an external SCP in the IN. This cuts down the amount of visits to the SCP. In this feature. see GSM Measurement Handling (TP). depending on the type of the location update: normal or periodic location update or IMSI attach. location registration procedures. This means that the subscriber may be using the network resources of a VLR area in which that particular subscriber is not allowed to roam. that is. whether the location registration is accepted or not. For more information. The PLMN index of the GPRS subscriber is determined on the basis of the SGSN address. 2. For more information. this feature is dependent on Feature 585: HLR Parameter Management. Capacity The roaming profile analysis affects the performance of the location update procedure to some extent. The trigger detection point in intra-VLR location registration is conditional.4 IN mobility management The IN MM feature is one of Nokia's non-call-related IN functions. the IN concepts and architecture are applied to the MM transactions. When the Support of the GPRS feature is available in the HLR. Interaction For the VLR address analysis. It also causes some additional system load in the HLR network element. An MM state model provides the operator with TDPs. the subscription-based network access is applicable also to the GPRS network. see Feature 857: Support of General Packet Radio Service. The SCP can then decide. thus enabling the SCP to serve more customers. Feature description. 38 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en .Location Registration Note When the subscriber roams in another VLR area during a call. for example. Feature Description. Location updated in the same VLR service area Location updated in another VLR service area IMSI attach MS-initiated IMSI detach Network-initiated IMSI detach . Gapping is a new service which gives better control over the SCP load. see Feature 1159: CAMEL Phase 3 Call Unrelated Parts. For more information on CAMEL Phase 3. . it is possible to offer Operator-Specific Services (OSS). Initiated by location registration. If the SCP is heavily loaded. for example. With CAMEL. for the subscriber while he is roaming outside the home PLMN.Location registration-related features Charging data can be collected from location updating procedures. the SCP can send charging information to the SSP. it can ask the SSP to limit the number of contact attempts for a certain service. location-dependent charging. For more information on IN MM. . intelligent network services. Statistical information about location updates rejected by the SCP are added to the trace report. Functionality of the feature IN MM services can be offered to different subscriber types as follows: DN987572 Issue 10-0 en # Nokia Siemens Networks 39 (53) . see Feature 742: IN Mobility Management. CAMEL (Customised Applications for Mobile network Enhanced Logic) is an IN architecture within GSM. . that is. In CAMEL Phase 3. a notification is sent to the CSE when the VPLMN has completed the processing of any of the following mobility management events: . This enables. Subscribers can use the operator-specific services they are accustomed to also when roaming in other networks. Feature Description. which will forward it to the billing center. CAMEL provides mechanisms to support services independently of the serving network. The services are provisioned in the PLMN-specific file in the VLR. An MM-SSF carries out the handling of detection points in the network elements. The protocol between the MM-SSF and the MM-SCF is Core INAP. The SCP includes an MM-SCF and a service logic program for the MM services. and the SCP. modified for the MM requirements. Offering the network services to the home subscribers must be avoided if there is a risk of overloading the network elements. The MM-SSF exists both in the HLR and in the VLR. the VLR. . SCP MM-SCF INAP INAP MSC SSP VLR MM-SSF HLR SSP MM-SSF MAP Figure 10. Network-specific services to all roaming subscribers on a PLMN basis. 40 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . The IN MM architecture consists of the HLR. IN mobility management architecture Capacity The IN MM feature increases the memory consumption of the HLR database by two Bytes per subscriber and that of the VLR database by one Byte per subscriber. the protocol is MAP version 2. Between the HLR and the VLR. Subscriber-specific services to the home subscribers. extended with the IN mobility management subscriber data. The services are provisioned in the subscriber data.Location Registration . but the default is that the waiting time is as short as possible to avoid overload in case the MM-SCF does not respond. Feature interworking MT USSD: the MM-SCF may use the USSD functionality to interact with the subscriber. it is assumed that these services are intended only for special subscribers. The use of transaction types in the intra-VLR LocUp DP. If the subscriber is allowed to roam within the zone. Operational view In unsuccessful location registration attempts. the location registration continues normally according to the zone code table. The value of this parameter can be adjusted by the operator. The operator may define on a zone basis whether triggering is allowed within the zone. Statistical information is also collected of gapped SCP visits. is independent of the location registration and it may be carried out as a separate transaction in the Ainterface. and triggering is allowed within the zone. not for all subscribers. The use of the call gapping process prevents the SCP overload. Therefore.Location registration-related features The load increase within one transaction might be considerable if triggering takes place. This functionality. The MM-SCF may use standard MAP signalling to interrogate or change the subscriber data in the HLR. a specific 'ReleaseCall cause' is added to the trace report both in the HLR and in the VMSC to indicate that the SCP rejected the location registration. This. DN987572 Issue 10-0 en # Nokia Siemens Networks 41 (53) . the InitialDP is sent to the SCP. cuts down the amount of SCP triggering. and the DP is met. The same happens if the Regional Roaming (Zone Codes) feature is used together with IN mobility management. increases the service capacity of the system. Otherwise. however. in turn. There is a specific timer parameter (SCP_AVAILABILITY_TIMER) in the VLR and in the HLR which determines the maximum waiting time of the first response from the SCP. Regional Roaming (Zone Codes) The Regional Roaming (Zone Codes) feature is needed if a location-based triggering condition is used. 42 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . This means that the operator can define the location areas where an individual subscriber can have the service.5 Regional roaming Regional roaming (zone code) allows the network operator to control subscriber roaming. the operator can define a default zone code list with the PLMN parameters in the VLR. the intra-VLR LocUp detection point should not be encountered in the periodic location registration transactions. To avoid congestion in the IN-network. the subscriber may have a roaming area that consists of 10 roaming areas around the 10 largest cities. for example. Also. because of the possible risk of overload. the PLMN-specific LocUp detection point should not be set for home-PLMN subscribers. The meaning of zones is defined in the VLR by the operator. and the location areas where IN MM triggering is allowed or not during the location update. The operator can configure the VLR so that if zone codes from the HLR are not accepted. several location areas. The FCI operation can be used only towards the SSP/MSC/VLR. while his roaming in scarcely populated areas is forbidden. the roaming area can be scattered: for example. If the default zones restrict roaming. the use of regional roaming is denied for roaming subscribers). No IN CDR is produced of periodic location registration. The operator defines the location areas belonging to the zones where roaming is allowed or not. the VLR checks the default zone codes before fetching any authentication vectors from the AuC or starting the location update towards the HLR. These zones are shown as zone codes for the subscriber's database in the HLR. The roaming area can be a single location area. the VLR saves the signalling towards the AuC and HLR. Also. or the whole PLMN.Location Registration Restriction Because of a risk of overload. this feature should not be provided for all subscribers. It cannot be used within the location registration TDP in the HLR. 2. If the subscriber does not have any zone codes in the HLR or those zone codes are not accepted (for example. If not all the zone codes of the subscriber are known by the VLR. The subscriber's zone codes are transferred to the VLR in the same order. the IN MM triggering is not done during the location update. The zones can deny or allow roaming and/or deny or allow IN MM triggering during the location update. If there is at least one zone that allows roaming. roaming is denied. In this case. the zone codes are read from the PLMN parameters. The checking of the IN is done only if the location update is allowed to the current location area. The sending of zone codes can be defined as a not allowed service in the PLMN parameters. roaming is allowed. that is. the operator creates the zones and assigns one or more location areas (in the corresponding MSC/VLR area) to them. see Feature 805: Regional Roaming. This means that the operator can define for the VLRs where the zone codes are sent. The operator can define what kind of cause value is sent to the MS when the location update is denied by regional roaming. Function in the MSC/VLR The operator creates the interpretation of the zones in the MSC/VLR. the location update is denied.Location registration-related features A subscriber who has only a limited access to the PLMN receives an error message when he tries to roam to a location area which is not provided for him. Function in the HLR The operator can define up to ten zone codes for the subscriber. If the IN denies roaming to the current location area. If none of the subscriber's zones apply to the MSC/VLR area. These zone codes are stored in the subscriber's database as permanent data. the HLR sets the msc_area_restricted flag to restricted and the HLR functions as if the subscriber could not be reached. a location update is acknowledged to the HLR with the information that the MSC area is restricted. If there is at least one zone that denies the IN MM triggering. The zone codes are stored in the database in the same order as they are given by the operator. If the subscriber does not get any zones from the HLR. This is very useful for roaming subscribers and solutions where most of the subscribers do not need any zone codes. Feature Description. DN987572 Issue 10-0 en # Nokia Siemens Networks 43 (53) . For more information on regional roaming. Location Registration If there are zone codes neither in the subscriber's database nor in the PLMN parameters. He can then define the same zone in both MSC/VLRs so that it includes the needed location areas in the corresponding MSC/VLR.. The table below represents the zone codes in the MSC/VLR. roaming is allowed to all location areas and the IN MM triggering is done as defined in the PLMN parameters when the location update occurs.. Zone codes in MSC/VLR Location area 2 .. The location area is then checked against the subscriber's zone codes. denied Zone Code 21 included= Y . Zone Code 8867 included= Y included= Y included= Y included= N included= Y included= N included= N included= N Location update in the MSC/VLR When the subscriber tries to do a location update for the first time in the MSC/VLR area.. This can be used if the operator wants to grant the subscriber a roaming area which extends to several MSC/VLR areas. the interpretation of the zone (allowing or denying zone). Location area n Location area 1 Zone Code 1 Roaming allowed IN trigg. Thus the total roaming area is the areas granted by individual zones together. Table 1. The operator can also assign several zones. 44 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . The operator can view the location areas of a particular zone. his zone codes are fetched from the HLR and stored among other subscriber information in the VLR. and the zones that are assigned to the subscriber. each of which is defined only in one MSC/VLR. Note The same zone can have a different interpretation in different MSC/VLR areas. an error message is the result. if not. . the location update is successful. the great number of regional subscribers affects the number of unsuccessful location update requests and thus increases the load in the network. the msc_area_restricted flag is set to restricted and all MT traffic is denied to the subscriber. his zone codes are fetched from the database of the MSC/VLR. In the HLR. The 'IMSI detach' mode is removed when the subscriber makes a successful location update. If the subscriber is known to the MSC/ VLR. the 'Absent Subscriber' error message is returned to the HLR if there is an attempt to transfer MT traffic to the subscriber. call and SM) are prevented. but the location update is not allowed by the zone codes. The memory consumption in the VISION database is 21 b/ subscriber/pair of VLR unit. that is. even simultaneously. . If the zone allows roaming. If the subscriber is known to the MSC/VLR. DN987572 Issue 10-0 en # Nokia Siemens Networks 45 (53) . call and SM) are prevented. Capacity This feature is applicable to all subscribers. When the MSC/VLR finds a zone which has the attempted location area defined. If the IMSI Detached flag is set because the called subscriber is not allowed to roam into the current location area. the zone's interpretation is checked: . the MSC/ VLR sets an 'IMSI detach' mode for that subscriber. If not all the zone codes of the subscriber are known by the VLR. the subscriber information is not deleted from the MSC/ VLR but mobile-originated and mobile-terminated traffic (for example. the subscriber information is not deleted from the MSC/VLR but mobile-originated and mobile-terminated traffic (for example. the IN MM triggering is not carried out. the location update is acknowledged to the HLR with the cause msc_area_restricted and the VLR sets an 'IMSI detach' mode for that subscriber. that is.Location registration-related features The checking starts from the first zone code that can be found from the subscriber. However. The memory consumption in the HOSTEL database is 22 b/subscriber/pair of HLR unit. If the location update is not allowed by the zone codes or IN MM triggering during the location update is denied. IN MM triggering during the location update is not done if the location is not allowed to the current location area. For more information. After a stand-alone insert or restore data operation. the mobile station performs a location update request which is subsequently denied. where the operator may define whether the triggering is allowed or denied per zone basis. see Feature 541: Subscription-Based Network Access. phase 2. Feature Description. 46 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . it is not possible to get the MS out of service before the next location update. the operator can transfer the network name. even if he moves to a forbidden location area. With the SAM parameter the operator can restrict roaming outside the HPLMN. For more information. if the subscriber makes a call and moves to a forbidden area and a handover occurs. The subscriber can have service during a handover. date. universal time. 2.Location Registration Feature interworking The feature can be used together with Feature 541: Subscription-Based Network Access. the default is that a subscriber without any zones provided has a full access to the network. if the triggering condition for location is used. Feature Description. see Feature 526: Charging Based on Home Area. The maximum number of zones per subscriber is 10 in the HLR database because only the zone code part of the RSZI is stored in the HLR database. By using the Subscription-Based Network Access feature the operator can define the not allowed VLRs in the HLR. and deleting the zone codes in the HLR. GSM restoration. for example. Feature Description. For example. However. when the MS registers to the network. This feature is needed in Feature 742: IN Mobility Management. If roaming is allowed (according to the SAM).6 Network identity and time zone With the Network Identity and Time Zone feature. the call continues normally. Regional roaming does not prevent a handover to a forbidden location area. After the call. Feature 526: Charging Based on Home Area facilitates the regionality and controls the charging. and time zone to the mobile station. Restrictions The maximum number of supported zone codes in one VLR is 500. see Feature 742: IN Mobility Management. it is the operator's responsibility to design the roaming and charging areas effectively. The functionality uses the zone code table. For more information. universal time. an MS supporting NITZ can set its clock automatically to local time and take daylight-saving times into account. time. For more information on NITZ. and for phase 2 mobile stations to store and use this information. The network name. see Feature 1005: Network Identity and Time Zone Support. Feature Description. DN987572 Issue 10-0 en # Nokia Siemens Networks 47 (53) . Furthermore. the realisation of the MS can be simplified because there is no more need to keep the clock running when the mobile station is in the power-off state. during an inter-VLR location update procedure during an IMSI attach procedure during a normal location update procedure during a periodic location update procedure . .7 Inter-system handover and UMTS changes in the MSC This feature is needed to ensure a successful migration to 3G and offers a wide range of high quality services for 2G and/or 3G subscribers. Each one of these elements is optional.Location registration-related features This enhances international/national roaming by permitting an accurate indication of network names that are either newer than the mobile station or have changed their name since the mobile station was sold or its software updated. Properties This feature makes it possible for a serving PLMN to transfer its current identity. and local time zone to the MSs. daylight-saving time. and local time zone information can be transferred from the serving PLMN to the MS in the following situations: . Also. . Capacity The feature has a very minor effect on the load of the BTS unit and the VLR unit. daylight saving time. Restrictions The 7-bit SMS coding scheme is used instead of UCS2 and 8-bit SMS coding. 2. For more information. This functionality provides clear benefits for the operators who have a different PLMN code in their UMTS and GSM radio access networks. as well. This can be done on a PLMN or IMSI range basis. In other words. All PLMNs in the stored list are regarded as equivalent to each other for PLMN selection and cell selection/re-selection. and for intra-UMTS inter-MSC relocation. The stored list consists of a list of equivalent PLMNs as downloaded by the network and the PLMN code of the network that downloaded the list. and/or operate networks also in other countries. and vice versa. the operators’ own core network can send the shared networks’ PLMN code as an equivalent PLMN to its subscribers. the operator can specify a set of PLMN identities which are sent to the mobile equipment in location updating. which makes cell selection seamless when the operator’s own subscriber moves between the shared and the operator’s own coverage areas. The subscriber 48 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . an international inbound roamer may select other operators' 3G PLMN. Equivalent PLMN In PLMN-specific parameters. see Feature 1260: Inter-system Handover and UMTS Changes in MSC. The Equivalent PLMN Functionality can also be used to keep international inbound roamers in the shared network when they move outside of the operators’ own network coverage area. the operator may use this feature to make the users registered in their network to prefer their partners' networks when the coverage of their own network is not available. The mobile equipment stores this list of 'equivalent PLMNs'. This includes network sharing cases. the necessary changes in the MSC for the support of UMTS are implemented in this feature. Otherwise. With these parameters the operator can control the subscribers' access to the network by giving access rights for a UMTS/GSM type subscriber to the UMTS/GSM radio network.Location Registration The feature provides support for handovers from GSM to UMTS. and/or have a shared network with another operator. Access control Access parameters are implemented in the VLR. Equivalent PLMN Functionality is a useful tool for enabling seamless cell re-selection among cells belonging to different PLMNs. Also. Additionally. The Equivalent PLMN Functionality has no impact on handovers because the UE does not select a new target cell for handovers but it is done by the SRNC using neighbour lists. Feature Description. . GSM subscriber allowed to BSS GSM subscriber allowed to UTRAN UMTS subscriber allowed to BSS UMTS subscriber allowed to UTRAN . the operator can define the following access right parameters: . The radio access information is sent by the MSC to the VLR. The VLR sends the access right parameters also to the MSC. DN987572 Issue 10-0 en # Nokia Siemens Networks 49 (53) .Location registration-related features type (UMTS/GSM) is derived by the VLR based on authentication vectors. If a separate cause code is not defined. If the subscriber type is unknown and the currently used access network is restricted for both user types. Each parameter can have the following values: TRUE or FALSE. can be set by the operator for each access right parameter separately. Cause codes. the VLR rejects the location update without retrieving authentication vectors from the AuC. Based on this information and access right parameters. The MSC uses these parameters to allow or reject the inter-system handovers for the served subscriber. The figure below shows the types of handovers that are supported with the help of this feature. . and with other UMTS features. For each PLMN. The operator can use the commands of the VLR and PLMN Parameter Handling command group (MX) to display and modify VLR-specific and PLMN-specific parameters. used if the VLR rejects the MM connection establishment or location updating. the default values are used. the VLR can accept or reject the MM connection establishment or location updating procedure accordingly. Handover support Changes in the MSC for the support of UMTS To be able to connect the UMTS radio network to the MSC and to be able to make Intra-UMTS/Inter-system handovers. . Security Requirements due to inter-system handover Key handling in basic and subsequent inter-MSC handovers BSSMAP R99 implementation in the A interface RANAP implementation in the MAP E interface MAP phase 3 implementation in the E interface Requirements coming from the support for Multiple RNCs per Multimedia gateway Signalling requirements for the Gs interface Charging and Statistics support Access and handover control . . . 50 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . . . the following requirements are set to the MSC: . . .Location Registration Inter MSC Inter PLMN InterSystem RNC < > BSC R99 IntraSystem RNC < > RNC InterSystem RNC -> BSC R98 BSC R98/R99 < > BSC R98/99 BSC R98 -> UMTS Intra MSC Inter PLMN Intra PLMN Intra PLMN supported not possible Figure 11. The MSC can repeat the paging via the A interface if it fails via SGSN (for example. It is possible to make a circuit-switched (CS) paging request via the SGSN (paging co-ordination). DN987572 Issue 10-0 en # Nokia Siemens Networks 51 (53) .8 Support of interaction with SGSN in MSC/VLR The support of this feature is realised by supporting a standard Gs interface in the MSC/VLR. they revert to the class C mode of operation). Although the CS paging request goes via the SGSN. Since the RA is a subset of only one LA. in network operation mode III. and thus save radio resources. and thus save radio resources. the changing of the LA of the GPRS MS also changes the RA. SGSN is not available. . An additional benefit is that the paging request is performed in a smaller area if it goes via the SGSN. the paging response comes to the MSC on its ordinary route. the following benefits are gained when a class A or B GPRS MS is used (class C MSs cannot be simultaneously IMSI. This is an important feature. The MT SMS and MT USSD paging also go via the SGSN. and the CS connection establishment continues in the usual manner. The paging procedure is supervised in the MSC by a paging timer. via the A interface. The combined request first goes to the SGSN that delivers the IMSI attach or detach request to the MSC/ VLR via the Gs interface. where the RA of the IMSI is updated. or there is an address error). It is possible to make a combined IMSI/GPRS attach or combined IMSI/ GPRS detach. . It is possible to make combined LA/RA updates in a PLMN that supports both the CS and the GPRS functionality. especially for those class B MSs that are capable of monitoring only one paging channel at a time (for example. IMSI is unknown in SGSN. The SGSN may also send the unreachable MS a message before the paging timer expires. If the Gs interface is supported by the SGSN and the MSC/VLR and thus a subscriber-specific association can be established between the CS and the GPRS network. MS is in GPRS-detached state. It is possible in those cases when the SGSN knows that the subscriber is absent.Location registration-related features 2.and GPRS-attached): . The SGSN delivers the LA update request further to the MSC/VLR via the Gs interface. A combined LA/RA update request first goes to the SGSN. Visitors Location Register (VLR). the VLR can ask it from the SGSN at the end of the location update with the MS Information Request procedure. in which the serving MSS may change. If the VLR does not receive the IMEI. 52 (53) # Nokia Siemens Networks DN987572 Issue 10-0 en . The NRI identifies an individual MSS serving within one pool area. From the NRI. the BSC or the RNC knows towards which MSC/ MSS the MS is directed.018. For more information. For more information. For more information. the new MSS requests MS-specific parameters from the old MSS. see Feature 1564: Multipoint A Interface. 2. Feature Description and Feature 1449: Multipoint Iu Interface in MSC server concept. however. Feature Description. see 3GPP Technical Specification 29. The VLR does not perform security checkings (authentication and IMEI checking) when the location update request comes through the GS interface because it relies on the security procedures of SGSN.9 Location update in pool area concept Features Multipoint A Interface and Multipoint Iu Interface in MSC server concept introduce a concept where BSC or RNC can be connected to several MSC/MSSs. . The IMEI (with software version) that the SGSN sends is accepted and stored to the VLR database optionally. it is supported in the 2G system and 3G circuit switched core network. Within a pool area the MS can roam without changing the serving CN node. This feature is not supported at the system level in 3G. In these procedures. see Feature 881: Support of Interaction with SGSN in MSC/VLR. The Gs interface also suppresses the periodic location updates of the GPRS-attached MSs in the VLR because the VLR relies on the periodic routing area updates in the SGSN. Location update An MS performs location area updates. which the serving MSS assigns to the MS. The area that is served by one or more MSC/MSS in parallel forms a pool area. General Packet Radio Service (GPRS). Gs interface layer 3 specification. The NRI is part of the temporary identity TMSI. Serving GPRS Support Node (SGSN) . Feature Description.Location Registration . The default node can be defined per LA. The default node forwards the request to the correct MSS in the old pool area. a default MSS for each LA is used. More than one MSS serving the pool area can be used as a default node. These nodes can therefore contact only one MSS per LA.Location registration-related features The new MSS uses the old LA together with the NRI to derive the signalling address of the old MSS from its own configuration data. Default MSS and backwards compatibility The MSSs that can derive the old MSS only from the LAI (for example. The correct MSS responds by sending the MS-specific parameters directly to the new MSS. This decreases the load on a single node. If the network contains nodes that cannot derive the old MSS from the LAI and the NRI. A default node that supports this feature derives the NRI from the TMSI. DN987572 Issue 10-0 en # Nokia Siemens Networks 53 (53) . This one node is referred to as the default node. or detailed information about the NRIs has not been configured) do not have the information of multiple MSSs serving an LA. because they do not support this feature.