6.3.12b Access Network selection for 5G NSWO

23.5013GPPRelease 18System architecture for the 5G System (5GS)TS

In addition to the PLMN lists specified in clause 6.3.12 and in clause 6.3.12a, a WLAN access network may also advertise the following PLMN list:

– A PLMN List-5, which includes PLMNs with which "AAA connectivity to 5GC" is supported. A WLAN access network supports "AAA connectivity to 5GC" in a PLMN when it deploys an AAA function that can connect with a NSWOF in this PLMN. The NSWOF supports "WLAN connection using 5G credentials without 5GS registration", as defined in clause 4.2.15.

When the UE wants to connect to a WLAN access network using the 5G NSWO procedure defined in TS 33.501 [29], Annex S, the UE may retrieve the PLMN List-5 advertised by each discovered WLAN access network and may consider this list for selecting the WLAN access network to connect to. For example, if the UE identifies that the HPLMN is included in the PLMN List-5 advertised by a WLAN access network, the UE may select this WLAN access network to connect to using the 5G NSWO procedure.

When the UE is configured by HPLMN to use 5G NSWO for connecting to WLAN access networks using its 5G credentials (as defined in TS 33.501 [29]), the UE shall attempt to select a WLAN that supports 5G NSWO and shall only use the 5G NSWO procedure for connecting to the selected WLAN.

A WLAN access network may also advertise a list of SNPNs which includes SNPNs with which "AAA connectivity to 5GC" is supported. A WLAN access network supports "AAA connectivity to 5GC" in an SNPN when it deploys an AAA function that can connect with a NSWOF in this SNPN. The NSWOF supports "WLAN connection using 5G credentials without 5GS registration", as defined in clause 4.2.15. When the UE operating in SNPN access mode wants to connect to a WLAN access network using the 5G NSWO procedure defined in Annex S of TS 33.501 [29], the UE may retrieve the SNPNs with which "AAA connectivity to 5GC" is supported that are advertised by each discovered WLAN access network and may consider this information for selecting the WLAN access network to which it attempts to connect.