7.11 Location Service
23.1193GPPGateway Location Register (GLR)Release 17Stage 2TS
This clause is based on that in 3G TS 23.171 [7].
7.11.1 Mobile Terminating Location Request
7.11.1.1 Circuit Switched Mobile Terminating Location Request (CS-MT-LR)
Figure 7.11/1: General Network Positioning for a MT-LR
7.11.1.1.1 Location Preparation Procedure
1) and 2) Same as the steps not involving GLR. See 3G TS 23.171 [7].
3) The HLR returns the current 3G-VMSC address that includes actually IM-MSC address. The other action is the same as the step not involving GLR. See 3G TS 23.171 [7].
4) The GMLC sends a MAP_PROVIDE_SUBSCRIBER_LOCATION message to the IM-MSC indicated by the HLR. The other action is the same as the step not involving GLR. See 3G TS 23.171 [7].
2′) If the IM-MSC already knows the VMSC location for the particular IMSI (e.g. from a previous location request), this step and step 3′ may be skipped. Otherwise, the IM-MSC sends a MAP_SEND_ROUTING_INFO_FOR_LCS message to the GLR of the target MS to be located with the IMSI of this MS.
3′) The GLR returns the current VMSC address and whichever of the IMSI and MSISDN was not provided in step (2′) for the particular MS.
4′) The IM-MSC sends a MAP_PROVIDE_SUBSCRIBER_LOCATION message to the VMSC indicated by the GLR.
5) to 8) Same as the steps not involving GLR. See 3G TS 23.171 [7].
7.11.1.1.2 Positioning Measurement Establishment Procedure
9) Same as the step not involving GLR. See 3G TS 23.171 [7].
7.11.1.1.3 Location Calculation and Release Procedure
10) Same as the step not involving GLR. See 3G TS 23.171 [7].
11′) The VMSC returns the location estimate and its age to the IM-MSC. The other action is the same as the step not involving GLR. See 3G TS 23.171 [7].
11) The IM-MSC receives the location estimate and its age, then sends them to the GMLC.
12) Same as the step not involving GLR. See 3G TS 3G 23.171 [7].
7.11.1.2 MT-LR for a previously obtained location estimate
Figure 7.11/2: MT-LR for a previously obtained location estimate
(1) to (4) Same as the step not involving GLR. See 3G TS 23.171 [7].
(2′) to (3′) Same as step 2′ for an MT-LR.
(4′) Same as step 4′ for an MT-LR. The message sent to the 3G-VMSC requests either an initial location or current or last known location with "no delay".
(5′) Same as step 11 for an MT-LR.
(5) Same as step 11 for an MT-LR.
(6) Same as the step not involving GLR. See 3G TS 23.171 [7].
7.11.1.3 Network Induced Location Request (NI-LR)
This procedure is the same as the procedure not involving GLR. See 3G TS 23.171 [7].
7.11.1.4 Network Induced Location Request (NI-LR) from a Serving RNC for a target UE in dedicated mode
This procedure is not related to GLR.
7.11.2 Mobile Originating Location Request
7.11.2.1 Mobile Originating Location Request, Circuit Switched (CS-MO-LR)
This procedure is the same as the procedure not involving GLR. See 3G TS 23.171 [7].