R.1 General

23.2283GPPIP Multimedia Subsystem (IMS)Release 18Stage 2TS

This annex describes how the user location and/or UE Time Zone information can be further distributed to IMS entities once it has been retrieved by either P-CSCF or an IMS AS. The exact mechanism for how the user location and/or UE Time Zone information are obtained is not described in this annex.

Information related to the location of the user provided by the access network may be required in IMS in order to comply with regulatory requirements (e.g. data retention, lawful interception) and/or in order to enable certain types of added value services based on the user’s location.

To simplify the information flows, the IMS AS shown in the figures can represent several AS’s. The CSCF represents the I-CSCF and/or the S-CSCF.

For the P-CSCF case in the originating side, the P-CSCF can, depending on operator policy, retrieve the user location and/or UE Time Zone information either before sending the INVITE towards the terminating side or upon reception of the SDP answer from the terminating side.

The transfer of the user location and/or UE Time Zone information within IMS signalling does not affect the transfer of any UE provided user location information. User location and/or UE Time Zone information provided in the signalling by the network will be distinguished from user location information provided by the UE.