5.49.4 Support of Additional ULI

The TAC and cell ID broadcasted by the MWAB-gNB are configured and reconfigured e.g. upon MWAB mobility as specified in TS 38.401 [42]. The MWAB-gNB provides these in the User Location Information (ULI) to the AMF serving the UE's accessing MWAB-gNB.

When a UE is served by a cell of MWAB-gNB, the MWAB-gNB shall also provide the Additional User Location Information (Additional ULI) that reflects the location of the MWAB-UE to the AMF when it sends the User Location Information (ULI) over N2 messages. In the Additional ULI, the MWAB-gNB provides the TAI/NR CGI of the MWAB Broadcasted PLMN/SNPN with which the UE is registered as specified in TS 38.401 [42].

NOTE: For the case of MWAB broadcasted PLMN/SNPN being different from the BH PLMN, or when the MWAB-UE is using the NTN access technology, MWAB-gNB formulates the Additional ULI as specified in TS 38.401 [42] based on MWABs geo-location. The MWAB can determine its geo-location using GNSS or via a MWAB-UE initiated 5GC-MO-LR procedures as specified in TS 23.273 [87]. If the MWAB broadcasted PLMN/SNPN is the same as the BH PLMN and the MWAB-UE is using TN access technology, then the TAI/NR CGI of the cell serving the MWAB-UE is included in the Additional ULI as specified in TS 38.401 [42].

If serving cell change report is required by AMF as specified in clause 4.10 of TS 23.502 [3], the MWAB-gNB shall report Additional ULI (and ULI) for the UE even when only serving cell of the MWAB-UE changes.

The AMF may consider the 'Additional ULI' when it determines UE location and manages the UE location related functions (e.g. Mobility Restrictions).

Based on operator policy, the AMF may send the Additional ULI when the AMF provides user location information it has received over the N2 interface to a NF (e.g. the LMF as specified in clause 5.19.1 of TS 23.273 [87]).

The MWAB-gNB indicates the Additional ULI to AMF(s) it connects to by NG Setup and RAN Configuration Update procedures as specified in TS 38.401 [42].