5.4.7 NG-RAN location reporting

NG-RAN supports the NG-RAN location reporting for the services that require accurate cell identification (e.g. emergency services, lawful intercept, charging) or for the UE mobility event notification service subscribed to the AMF by other NFs. The NG-RAN location reporting may be used by the AMF when the target UE is in CM-CONNECTED state. The NG-RAN location reporting may be used by the AMF to determine the geographically located TAI in the case of NR satellite access.

The AMF may request the NG-RAN location reporting with event reporting type (e.g. UE location or UE presence in Area of Interest), reporting mode and its related parameters (e.g. number of reporting).

If the AMF requests UE location, the NG-RAN reports the current UE location (or last known UE location with time stamp if the UE is in RRC_INACTIVE state) based on the requested reporting parameter (e.g. one-time reporting or continuous reporting).

If the AMF requests UE location, in the case of NR satellite access, the NG-RAN provides all broadcast TAIs to the AMF as part of the ULI. The NG-RAN also reports the TAI where the UE is geographically located if this TAI can be determined.

If the AMF requests UE presence in the Area Of Interest, the NG-RAN reports the UE location and the indication (i.e. IN, OUT or UNKNOWN) when the NG-RAN determines the change of UE presence in Area Of Interest.

After N2 based Handover, if the NG-RAN location reporting information is required, the AMF shall re-request the NG-RAN location reporting to the target NG-RAN node. For Xn based Handover, the source NG-RAN shall transfer the requested NG-RAN location reporting information to target NG-RAN node.

The AMF requests the location information of the UE either through independent N2 procedure (i.e. NG-RAN location reporting as specified in clause 4.10 of TS 23.502 [3]), or by including the request in some specific N2 messages as specified in TS 38.413 [34].