7.2.3 Functional requirements of VLR

23.0183GPPBasic call handlingRelease 15Technical realizationTS

7.2.3.1 Process PRN_VLR

Sheet 1: the procedure Check_Parameters is specified in subclause 7.2.2.2.

Sheet 1: the test "Pre-paging allowed" takes the "yes" exit if:

– the information element "Pre-paging supported" was present in the Provide Roaming Number message; or

– as an operator option, the paging procedure can be completed before the minimum timer value for the Provide Roaming Number operation timer in the HLR has elapsed.

Sheet 1: the procedure Check_Reason_In_Serving_Network_Entity is specific to Super-Charger; it is specified in 3GPP TS 23.116 [24]. If the VLR does not support Super-Charger, processing continues from the "No" exit of the test "Result=Purged?".

Sheet 1: Pre-paging is not applicable if the Provide Roaming Number request includes the MTRF Indicator.

Sheet 2, sheet 3, sheet 6, sheet 7: the procedure CAMEL_SET_SOA is specific to CAMEL; it is specified in 3GPP TS 23.078 [12].

Sheet 2, sheet 3, sheet 6, sheet 7: the task "Store alerting pattern (if received)" is executed only if the VLR supports the feature Network Indication of Alerting.

Sheet 2, sheet 3, sheet 6, sheet 7: the procedure CLI_PRN_VLR is specific to Enhanced CLI Handling. It is specified in 3GPP TS 23.081 [14].

Sheet 2, sheet 3, sheet 6, sheet 7: the procedure CCBS_Handle_PRN is specific to CCBS; it is specified in 3GPP TS 23.093 [23].

Sheet 2, sheet 4: A VLR not supporting the flag "Subscriber data dormant" shall behave as if this flag is set to false.

Sheet 2: As an implementation option, the VLR may skip the "Authorize_MTRF_VLR" procedure (i.e. assume the result of that procedure takes the "Pass" exit) and allocates an MSRN before the completion of the MAP Update Location procedure with the HLR.

Sheet 3, sheet 4: the number of unused authentication sets which triggers the VLR to request further authentication sets from the HLR is an operator option.

Sheet 3, sheet 4: the process Fetch_Authentication_Sets_VLR is specified in subclause 7.1.2.11.

Sheet 4: the procedure Search_For_MS_VLR is specified in subclause 7.3.2.3.

Sheet 4: the test "Paging via SGSN possible" takes the "yes" exit if:

– the Gs interface is implemented; and

– there is an association established for the MS between the MSC/VLR and the SGSN.

Sheet 4: "Location cancelled" cause is set when VMSC receives Cancel Location while paging.

Sheet 6: "Location cancelled with new VLR address" cause is set when VMSC receives Cancel Location with MTRF Supported And Authorized while paging and new MSC/VLR numbers have been received either in the Cancel Location or the Send Identification message.

Sheet 7, sheet 8: the state variables PAR pending, PAR successful and Fatal PAR error are global data, accessible to the matching instance of the process ICH_VLR, which is linked by the MSRN.

Sheet 8: this process communicates with the matching instance of the process ICH_VLR, which is linked by the MSRN.

Sheet 8: the test " Fatal PAR error?" takes the "Yes" exit if:

– the MS failed authentication; or

– the MS failed IMEI checking; or

– the HLR returned an "Unknown subscriber" error;

during the handling of the Process Access Request.

7.2.3.2 Process Restore_Subscriber_Data_VLR

7.2.3.3 Process PSI_VLR

Sheet 1: the procedure Check_Parameters is specified in subclause 7.2.2.2. If the HLR requests none of location information subscriber state, MS classmark and IMEI, the VLR treats this as a missing parameter.

Sheet 2: the test "Active retrieval required" takes the "Yes" exit if any one or more of current location, MS classmark or IMEI is indicated in the Provide Subscriber Info request.

7.2.3.4 Procedure Retrieve_Location_Info_VLR

The test "Retrieve location info from SGSN" takes the "Yes" exit if:

– the Gs interface is implemented; and

– there is an association established between the VLR and the SGSN.

The stored location information consists of:

– the service area ID (for UMTS) or cell ID (for GSM) or the tracking area ID and the E-UTRAN cell ID (for E-UTRAN) of the cell in which the MS last established radio contact;

– the location number, geodetic information and geographical information derived from the service area ID or cell ID if the VLR is capable of doing so (the mapping from service area ID or cell ID to location number is network-specific and outside the scope of the UMTS and GSM standards);

– the age of the location information.

The output signal Send MS information towards the SGSN indicates that the required information is mobile location information.

The received location information consists of:

– the service area ID (for UMTS) or cell ID(for GSM) received in the paging response message or in the Send MS Information ack or the tracking area ID and the E-UTRAN cell ID (for E-UTRAN) received in the SGs service request;

– the location number, geodetic information and geographical information derived from the service area ID or cell ID if the VLR is capable of doing so (the mapping from cell ID to location number is network-specific and outside the scope of the UMTS and GSM standards);

– the age of the location information.

The derivation of the location number, geodetic information and geographical information from the received service area ID or cell ID is a VLR operator option (the mapping from service area ID or cell ID to location number is network-specific and outside the scope of the UMTS and GSM standards).

7.2.3.5 Procedure Active_Info_Retrieval_VLR

Sheet 1: the test "Paging via SGSN possible" takes the "yes" exit if:

– the Gs interface is implemented; and

– the VLR configuration requires paging via the SGSN during VLR restoration.

If the SGs interface is implemented and the conditions for paging over the SGs interface as specified in subclause 5.1.2.2 of 3GPP TS 29.118 [41] are fulfilled, the VLR shall send an SGs paging request to the MME. The VLR should indicate the "SMS" service indicator in the SGs paging request if the LocationInformationEPS-Supported flag was received in the Provide Subscriber Information request; otherwise the VLR should indicate the "CS" service indicator. If the VLR indicates the "SMS" service indicator, the VLR should then send an SGs Release Request message to the MME upon receipt of the SGs Service Request message (including the tracking area ID and E-UTRAN cell ID).

The VLR should return in the Provide Subscriber Information response the tracking area ID and E-UTRAN cell ID received from the MME if the LocationInformationEPS-Supported flag was received in the Provide Subscriber Information request and the UE uses the E-UTRAN radio access; otherwise the VLR should return the service area ID (for UMTS) or cell ID (for GSM) received from UTRAN or GERAN.

NOTE: Using the "CS" service indicator leads the UE to fallback to GERAN or UTRAN radio access which can affect on-going PS sessions of the user, e.g. suspend on-going PS sessions if the UE fallbacks to GERAN radio access and Dual Transfer Mode is not supported, and which can cause extra Location Update signalling in the network.

Sheet 2: the output signal Page MS towards the SGSN includes or omits the Location area identity parameter depending on the availability of this information. If it is omitted, the signal Page MS is sent to every SGSN to which the VLR is connected.

The test "Report upon change of service area" takes the yes exit if the MSC has performed the Location Reporting Control procedure with the Request Type IE set to "change of service area" [26].

If the test "Report upon change of service area" takes the no exit, then the MSC shall perform a Location Reporting Control procedure with the Request Type IE set to "Direct".

Figure 55a: Process PRN_VLR (sheet 1)

Figure 55b: Process PRN_VLR (sheet 2)

Figure 55c: Process PRN_VLR (sheet 3)

Figure 54d: Process PRN_VLR (sheet 4)

Figure 54e: Process PRN_VLR (sheet 5)

Figure 54f: Process PRN_VLR (sheet 6)

Figure 54g: Process PRN_VLR (sheet 7)

Figure 54h: Process PRN_VLR (sheet 8)

Figure 56: Process Restore_Subscriber_Data_VLR

Figure 57a: Process PSI_VLR (sheet 1)

Figure 57b: Process PSI_VLR (sheet 2)

Figure 58: Procedure Retrieve_Location_Info_VLR

Figure 59a: Procedure Active_Info_Retrieval_VLR

Figure 59b: Procedure Active_Info_Retrieval_VLR (sheet 2)

Figure 59b: Procedure Authorize_MTRF_VLR