GSM 09.02 - Version 5.3.0 - Digital cellular telecommunications - ETSI

Page 282
GSM 09.02 Version 5.3.0: August 1996
16 Mobility procedures
16.1 Location management Procedures
This subclause comprises a number of processes to handle the mobile nature of the subscriber. The
processes will be addressed by SCCP Sub-System Number (MSC, VLR or HLR) and the Application
Context. The following processes are defined in this subclause:
Process Update Location Area:
Initiator: Update_Location_Area_MSC, subclause 16.1.1.2;
Responder: Update_Location_Area_VLR, subclause 16.1.1.3;
Process Update Location:
Initiator: Update_Location_Area_VLR, subclause 16.1.1.3, or
Update_Location_VLR, subclause 16.1.1.6;
Responder: Update_Location_HLR, subclause 16.1.1.4;
Process Send Identification:
Initiator: Update_Location_Area_VLR, subclause 16.1.1.3;
Responder: Send_Identification_VLR, subclause 16.1.1.5;
Process Subscriber Present HLR:
Initiator: Subscriber_Present_HLR, subclause 16.1.1.7;
Responder: Short_Message_Alert_IWMSC, subclause 20.4.3;
Process Cancel Location:
Initiator: Cancel_Location_HLR, subclause 16.1.2.2;
Responder: Cancel_Location_VLR, subclause 16.1.2.3;
Process Detach IMSI:
Initiator: Detach_IMSI_MSC, subclause 16.3.2;
Responder: Detach_IMSI_VLR, subclause 16.3.3.
As both the Update Location Area and the Detach IMSI processes use the same application context name,
the MAP Provider cannot distinguish between them. Therefore, a Location Management Co-ordinator
Process will act as one user for this application context. This process (one in MSC, one in VLR) will create
the Update Location Area or the Detach IMSI process, depending on the first service primitive received in
the respective dialogue.
Additionally, a Location Management Co-ordinator process in the HLR co-ordinates the two application
processes "Update Location HLR" (subclause 16.1.1.4) and "RESTORE_DATA_HLR" (subclause 16.3.3)
that are addressed by the same application context.
Location Management Co-ordinator MSC
On receipt of a request for location updating from the A-interface, the Location Management Co-ordinator
in the MSC will:
- create the process Update_Location_Area_MSC in case the updating type indicated in the
A-interface primitive indicates normal updating, periodic updating or IMSI Attach;
- create the process Detach_IMSI_MSC in case the updating type indicated in the A-interface
primitive indicates IMSI Detach.
The respective primitive is then forwarded to the created process. Henceforth, the co-ordinator will relay
all service primitives from provider to the user and vice versa, until a request or indication for dialogue
termination is received. This last primitive will be relayed, too, before the Co-ordinator process returns to
idle state.