9.2a Common Positioning Procedure for PS Domain in A/Gb mode

3GPP43.059Functional stage 2 description of Location Services (LCS) in GERANRelease 17TS

This procedure is common to all positioning methods in the PS domain.

Figure 28a: Common Positioning Procedure for PS Domain

1) The BSS sends the BSSAP-LE Perform Location Request message to request the SMLC to start the positioning procedure. The Location Type, and Current Cell Identifier IEs are always included. If the Timing Advance value for the MS is available in the BSS, it shall be included (in BSSLAP APDU IE). Depending on the type of location request and the MS capability, additional parameters may be included to provide Measurement Report (in BSSLAP APDU IE), Packet Measurement Report, LCS Client Type, LCS Capability, LCS Priority, LCS Quality of Service, and A-GNSS Assistance Data. In addition, the IMSI and / or the IMEI of the mobile station involved in the positioning procedure may be provided by the BSS in order to allow the SMLC to maintain a context between subsequent requests for a mobile station, to tune positioning for each mobile station and to add more options for SMLC diagnostics.

2) See step 2 of clause 9.2 "Common Positioning Procedure for CS Domain in A/Gb mode". For a MS that only supports EC-GSM-IoT only the TA based positioning method is supported, see clause 9.3a.

3) The SMLC sends the BSSAP-LE Perform Location Response message to the BSS. A location estimate, velocity estimate, positioning data, deciphering keys, or LCS Cause may be included.