16.2.3 HSS retrieval of information about an UE from the TWAN serving that UE

23.4023GPPArchitecture enhancements for non-3GPP accessesRelease 18TS

The procedure described in this clause supports the HSS retrieval of information about an UE from the TWAN serving that UE.

The information that the HSS can fetch corresponds to user location (TWAN ID) and/or UE Time Zone information (this information may e.g. be provided to an IMS AS that has requested the information as detailed in Annex R of TS 23.228 [74]). The User location information sent to the HSS contains information on the last known time of radio contact.

The TWAN ID is defined in clause 16.1.7.

Figure 16.2.3: HSS retrieval of information about an UE from the TWAN

1) The HSS determines that it needs to get from the TWAN access Information about the UE (defined above the figure). The HSS sends an UE Information Request (UE Identity (IMSI), Nature of the Information to fetch) via the 3GPP AAA server supporting this UE.

2) The 3GPP AAA server determines the TWAN supporting an UE and transfers the request to the TWAN. In case of roaming a 3GPP AAA proxy is used.

3) The TWAN answers by an UE Information Response (UE Identity (IMSI), Information requested). In case of roaming a 3GPP AAA proxy is used

4) The UE Information Response is relayed from 3GPP AAA server to HSS.