5.4.11.4 Verification of UE location

In order to ensure that the regulatory requirements are met, the network may be configured to enforce that the selected PLMN is allowed to operate in the current UE location by verifying the UE location during Mobility Management and Session Management procedures. The UE that supports network verified UE location over NTN NR shall indicate this capability in UE 5GMM Core Network Capability and LPP as defined in TS 37.355 [191].

In this case, when the AMF receives a NGAP message containing User Location Information for a UE using NR satellite access, the AMF takes into account the capability of the UE in UE 5GMM Core Network Capability for the support by the UE of network verified UE location over NR NTN and may decide to verify the UE location. If the AMF determines based on the Selected PLMN ID and ULI (including Cell ID) received from the gNB that it is not allowed to operate at the present UE location the AMF should reject any NAS request with a suitable cause value. If the UE is already registered to the network when the AMF determines that it is not allowed to operate at the present UE location, the AMF may initiate deregistration of the UE. The AMF should not reject the request or deregister the UE unless it has sufficiently accurate UE location information to determine that the UE is located in a geographical area where the PLMN is not allowed to operate.

NOTE 1: The area where the UE is allowed to operate can be determined based on the regulatory area where the PLMN is allowed to operate based on its licensing conditions.

If the AMF, based on the ULI, is not able to determine the UE's location with sufficient accuracy to make a final decision or if the received ULI is not sufficiently reliable, the AMF takes into account the UE 5GMM Core Network Capability related to the UE support of network verified UE location over NR NTN and may proceed with the Mobility Management or Session Management procedure and may initiate UE location procedure after the Mobility Management or Session Management procedure is complete, as specified in clause 6.10.1 of TS 23.273 [87], to determine the UE location.

NOTE 2: In order to ensure that the regulatory requirements are met, based on operator configuration, the AMF can prevent the UE from accessing certain services (e.g. services related with NAS messages initiated by UE or network except services related with UE location procedures or NAS procedures required for location verification) while location determination is ongoing. This can be done by, for example, the AMF providing a back-off time to the UE, such as described in clause 5.19.7.2 NAS level congestion control.

The AMF shall be prepared to deregister the UE if the information received from LMF indicates that the UE is registered to a PLMN that is not allowed to operate in the UE location. In the case of a NAS procedure, the AMF should either reject any NAS request targeted towards a PLMN that is not allowed to operate in the known UE location and indicate a suitable cause value, or accept the NAS procedure and initiate deregistration procedure once the UE location is known. In the deregistration message to the UE, the AMF shall include a suitable cause value. For UE processing of the cause value indicating that the PLMN is not allowed to operate in the current UE location, see TS 23.122 [17] and TS 24.501 [47].

In the case of a handover procedure, if the (target) AMF determines that it is not allowed to operate at the current UE location, the AMF either rejects the handover, or accepts the handover and later deregisters the UE.