4.22.3 Authorization of C2 communication

The 5GS supports USS authorization of C2 communication for pairing of UAV and UAV-C. The pairing of UAV and UAV-C needs to be authorized by USS successfully before the user plane connectivity for C2 communication (over Uu or over NR-PC5) is enabled. For C2 authorization procedure, the UE supporting UAS services provides to the network with CAA-level UAV ID.

The USS authorization of UAV flight can also be performed during the C2 authorization procedure. The UE supporting UAS services provides the UAV flight authorization information to the network if provided by upper layers.

NOTE 1: The C2 authorization payload in the service-level-AA payload can include one, some or all of the pairing information for C2 communication, an indication of the request for direct C2 communication, pairing information for direct C2 communication, and the UAV flight authorization information (see clauses 6.4.1.2 and 6.4.2.2).

The UE supporting UAS services can establish a PDU session for the C2 communication by providing the CAA-level UAV ID and the C2 authorization payload. The SMF upon reception of the UE's request for the PDU session establishment, determines that authorization is required based on the DNN and S-NSSAI combination of the PDU session is for aerial services according to user's subscription data and the CAA-level UAV ID included in the request.

If a UE supporting UAS services uses a common PDU session for both USS communication and C2 communication, the C2 communication can be authorized using UUAA-SM procedure during the PDU session establishment procedure or during the PDU session modification procedure. If the pairing of UAV and UAV-C is revoked, the network shall disable C2 communication for the PDU session. The SMF upon reception of the UE's request for the PDU session establishment, determines that authorization is required based on the DNN and S-NSSAI combination of the PDU session is for aerial services according to user's subscription data and the CAA-level UAV ID included in the request.

NOTE 2: The network can disable C2 communication for the PDU session e.g. by removing the QoS flow for C2 communication during PDU session modification procedure as decribed in clause 6.3.2.2.

If a UE supporting UAS services uses separate PDU sessions for, respectively, USS communication and C2 communication, the C2 communication is authorized using UUAA-SM during the PDU session establishment procedure. If the pairing of UAV and UAV-C is revoked, the PDU session for C2 communication shall be released by the SMF.

During the registration procedure for UAS services, direct C2 communication can be authorized as described in clause 5.5.1.2. A UE supporting A2X over NR-PC5 can perform registration procedure for UAS services including a request for authorization of direct C2 communication by providing CAA-level UAV ID and C2 authorization payload.