Content for  TS 23.256  Word version:  18.2.0

Broadcast Remote ID leverages A2X broadcast communication mode as defined in clauses 6.2.2.1.2 and 6.3.3.1, for both UAV UEs that register to the MNO network(s) and UAVs that operate out of coverage. The content of the messages for BRID is defined according to regional regulations for BRID (e.g. message set of ASTM F3411.19 [13] or ASD-STAN prEN 4709-002 P1 [14]) and optionally according to regional mean of compliance documents. Authorization and provisioning of policy parameters for A2X communication over PC5 reference point as described in clause 6.2.1.2 is leveraged. Where applicable, an A2X service type indicating Broadcast Remote ID is used.

DAA leverages procedures and mechanisms as defined for A2X in clause 6. This includes the corresponding references to TS 23.287 below. The detection and deconfliction of potential collisions between UAVs is locally performed between UAVs using direct UAV to UAV communication over PC5. The USS may be informed of the potential collision situation. Deconflicting policy which indicates the communication mode (unicast or broadcast) used for deconflicting for A2X is defined in clause 6.2.1.2.1. Authorization and provisioning of policy parameters for A2X communication over PC5 reference point as described in clause 6.2.1.2 is leveraged.

The steps 5 and 6 are then exchanged over the established unicast link.

This clause provides a network-assisted (ground based) DAA mechanism. It is applicable for a specific area, such as a stadium or arena where UAVs are used e.g. for filming an event. It is based on a ground-based entity, Area Airspace Manager (AAM), that is able to detect UAVs in the specific area and provide local steering policies to the individual UASs in order to avoid the UAVs crashing into each other or different structures etc. The policy may e.g. include allowed flying zones and positions allowed for the specific UAV. The policy may also apply to a specific outdoor area, e.g. an event, where specific measures to avoid collision between drones are established locally. The high-level principles of the network-assisted (ground based) DAA are:

• The arena/area has a ground-based entity Area Airspace Manager (AAM). The AAM includes one or more UEs enabled for use of PC5. The AAM may also have a direct connection to the Data Network.
• For the applicable airspace of the area/arena the AAM defines individually adapted local collision avoidance rules for correspondingly located UAVs.
• Provisioning of AAM local collision avoidance rules to a UAV/UE must comply with the policies for PC5 operations received from the 5GC or being preconfigured in the UE.
• Detected UAVs are identified by their coordinates and by the Remote ID as retrieved by Broadcast Remote ID (BRID) or Network Remote ID (NRID) mechanisms dependent on the method used by the UAV.
• Based on the retrieved Remote ID, the AAM activates PC5 communication with each detected UAV by triggering establishment of an A2X PC5 unicast link based on procedures described in clause 6 using the UAV's Remote-ID as Application-Layer-ID (i.e. Target User Info) in the Direct Communication Request message.

For Direct Communication over PC5 the UAV and AAM shall comply with the authorization and provisioning principles described in clause 4.2.1.2.2 including the following considerations:

• The default destination Layer-2 ID to be used for initial signalling to establish a unicast connection for the A2X service.
• Parameters for Groupcast are not applicable.
• The AAM uses PC5 unicast link to provide each UAV present in the arena/area with local DAA policies as user traffic.
• A UAV that receives local collision avoidance related policies from the AAM over PC5 may forward the policies to its UAV-C so that the UAV-C can steer the UAV accordingly by use of C2 communication (e.g. over Uu, PC5, or other means) in order to enforce the local policies and avoid collisions.

Ground-based DAA for an area leverages the procedures and mechanisms defined for A2X. Any references to TS 23.287 made in this clause shall be interpreted in accordance with corresponding definitions and descriptions for A2X in clause 6. Prerequisites: