For UAV location reporting mode, the USS/TPAE that wants to be reported on the UAV location subscribes to the UAS NF with the target 3GPP UAV ID. The USS/TPAE could indicate the required location accuracy and whether it's for immediate reporting or deferred reporting (e.g. periodic reporting). With the request received from USS/TPAE, UAS NF identifies the related NF, i.e. GMLC and trigger existing procedures to retrieve the location report. Then UAS NF reports back the UAV's location together with the 3GPP UAV ID to the USS/TPAE.
For UAV presence monitoring mode, the USS/TPAE may subscribe for the event report of UAV moving in or out of the geographic area (e.g. longitude/latitude, zip code, etc). The request includes target 3GPP UAV ID and geographic area info.
If the requested geographic area info can be mapped to 3GPP defined area, such as a list of Tracking Areas or a list of cells as currently supported by 3GPP network as the Area Of Interest, UAS NF subscribes to AMF/MME for reporting the presence of the UAV in Area Of Interest using existing AMF/MME procedures, otherwise UAS NF subscribes to GMLC for configuring the presence monitoring. Upon receiving the report from AMF/MME or GMLC, the UAS NF notifies USS/TPAE for the UAV presence in the geographic area.
The USS may provide policies or rules to UAS NF based on the received event notification. If the traffic routing policies or rules were provided to UAS NF, when the location of UAV or the UAV presence in the monitoring area matches a policy, UAS NF based on the policy indicates SMF to take the appropriate network layer actions, e.g. revoke the connectivity between UAV and UAV controller. UAS NF considers those policies as active and ongoing instructions from USS without constant or repeated triggers/requests from USS. The traffic routing policy includes 3GPP UAV ID(s) (i.e. GPSI(s)) to identify the UAV(s) and the corresponding network layer actions e.g. revoke the resources of the related C2 communications.
In this mode, the USS/TPAE requests UAS NF for a list of the UAVs in the geographic area and served by the PLMN (i.e. no 3GPP UAV ID provided by the USS/TPAE). The request includes geographic area info and indication of one-time reporting by setting "maximumNumberOfReports"
to 1. If the geographic area info can be mapped to 3GPP defined area such as a list of Tracking Areas or a list of cells, UAS NF triggers existing AMF/MME procedures to get the UE list within the TAI(s) or Cell Id(s). The UAS NF may include Aerial UE indication as an event filter in the request, that is used by the AMF/MME to separate out the UEs that are actual UAVs based UEs with aerial subscriptions. If the geographic area info cannot be mapped to 3GPP defined area such as a list of Tracking Areas or a list of cells, UAS NF provides a list of Tracking Areas which is larger than the geographic area to AMF/MME to retrieve the UE list within the list of Tracking Areas. Then UAS NF identifies UAVs from the UE list and obtains the location for each identified UAV via LCS procedure toward GMLC. The UAS NF compares the UAV location with the geographic area to identify the UAVs in the geographic area and provides feedback to USS/TPAE. For the UAV list received from the AMF/MME or the UAV list identified with GMLC provided location, the UAS NF performs the filtering by checking for each 3GPP UAV ID reported whether there is match for the corresponding UAV context. The UAS NF may also verify whether the requesting USS is authorized to obtain the location info of the UAV.
In the above UAV tracking modes, UAS NF may need to map the 3GPP UAV ID to 3GPP internal IDs and vice versa. The CAA Level UAV ID may be optionally provided by the UAS NF, if available, to the USS/TPAE during tracking and location reporting of UAV.