16.1.7 Access Network information reporting in case of a TWAN Access

23.4023GPPArchitecture enhancements for non-3GPP accessesRelease 18TS

In order for an Application Function (e.g. the P-CSCF) to be able to determine the NPLI (Network Provided location Information) of an UE in case of a TWAN access, the TWAN shall report over S2a TWAN related Access Network Information at PDN connection establishment, at bearer creation / modification / release and at PDN connection release. Such TWAN related Access Network Information may correspond to a "TWAN Identifier" and/or to a UE Time Zone.

The TWAN Identifier (reported over S2a, Gx, Gy, …) shall include the SSID of the access point to which the UE is attached and shall include at least one of the following elements, unless otherwise determined by the TWAN operator’s policies:

– the BSSID (see IEEE Std 802.11-2012 [64]);

– civic address information of the AP to which the UE is attached;

. line identifier (Logical Access ID see ETSI ES 282 004 [77]) of the access point to which the UE is attached.

NOTE 1: The SSID can be the same for several WLAN APs and SSID only may not provide a location, but it might be sufficient for charging purposes.

NOTE 2: The Information carried as part of theTWAN Identifier should be defined to cater for extension in future releases.

The TWAN Id may also contain the identifier of the operator of the TWAN. When the TWAN is operated by a mobile operator, this corresponds to a PLMN-ID. When the TWAN is not operated by a mobile operator, this corresponds to an operator Name (e.g. in Realm format).