Content for  TS 23.256  Word version:  19.0.0

This specification covers UAV functionality provided by 5GC connected to NG-RAN and EPC connected to LTE. The following functionality is defined for UAV support in the 3GPP system:

• An UAV is authenticated and authorized by USS via a USS UAV Authentication & Authorization (UUAA) with the support of the 3GPP system before connectivity for UAS services is enabled.
• Depending on 3GPP network operator and/or regulatory requirements, the UUAA is performed:
  • In 5GS: either as a separate procedure during the 5GS registration procedure (optional and based on specific PLMN policies, USS requirements, and geographic regulatory requirements), or when the UAV requests user plane resources for UAV operation (i.e. PDU session establishment). The UAV shall support UUAA during Registration and PDU session establishment procedure. The network shall support UUAA during PDU session establishment.
  • In EPS: during the attach procedure and the corresponding PDN connection establishment. The network shall support UUAA during PDN connection establishment. The UAV shall support UUAA during PDN connection establishment procedure.
• A UAV that is provisioned with a CAA-Level UAV ID shall provide the CAA-Level UAV ID in 5GS in both Registration and in PDU Session establishment. In EPC, a UAV that is provisioned with a CAA-Level UAV ID provides the CAA-Level UAV ID in PDN Connection establishment in SM-PCO. The CN determine whether UUAA is executed at 5GS registration or at PDU session/PDN Connection establishment, based on local policies.
• The UUAA is performed at PDU session establishment when the UAV requests user plane resources for UAV operation and the UAV provides its CAA Level ID during PDU session (PDN connection) establishment.
• The UAV flight authorization and UAV-UAVC pairing authorization is performed at PDU session/PDN connection establishment/modification procedures.
• The 3GPP system supports USS authorization of pairing between a UAV and a networked UAVC or a UAVC that connects to the UAV via Internet connectivity during either the establishment of the PDN connection/PDU session for C2 communication or a modification of a PDN connection/PDU session either dedicated to C2 communication or common to USS communication and C2 communication. Modifications of the pairing or re-authorization take place via modification of the established PDN connection/PDU session. During such procedures, the USS provides to the 3GPP system information (e.g. QoS requirement, data flow descriptors, etc.) that enable traffic between the UAV and the UAVC.
• For EPC, the PDN connections used by UAV are served by SMF+PGW-C regardless of whether the UAV support 5G NAS or whether their subscription allows access to 5GC. The APN(s) used by the UAV for contacting USS or for C2 communication always resolves to a SMF+PWG-C.

The following architectural assumptions apply:

• It is assumed that the UAV trying to access UAS services using 3GPP connectivity is already registered with a USS and has been assigned a CAA-Level-UAV ID. The procedure for UAV registration and assignment of CAA-Level-UAV ID is out of scope of 3GPP. The USS assigns to the UAV a CAA-Level UAV ID, or is made aware of the assigned CAA-Level UAV ID.
• A UAV is associated with an Aerial subscription in the UDM. The Aerial subscription contains aerial UE indication in the Access and Mobility Subscription data (to be used similarly to aerial UE indication defined in EPS), an aerial service indication in the Session Management Subscription data for each DNN dedicated for UAS services (C2 and UUAA-SM) which indicates that corresponding authentication/authorization has to be done using API based mechanism.
• An UAV is identified by USS using a CAA-level UAV ID, and identified by the 3GPP System using a 3GPP UAV ID assigned by the MNO:
  • It is assumed that an aerial subscription associated to a UAV includes at least one GPSI to be used as 3GPP UAV ID.
• A UAV is registered with the USS either before connecting with the 3GPP system or using plain internet connectivity via the 3GPP system. Before registering for UAS services with the 3GPP system, the UAV shall be provisioned with a CAA-Level UAV Identity.
• In roaming scenarios, it is assumed that access to USS is in the VPLMN, thus packet data connectivity for UAV-USS communication is in local breakout, and the UAS NF function is located in the VPLMN.
• In this Release, the UAV uses 3GPP access (i.e. LTE & NR) for 3GPP UAV related operations.
• Activation of RAN aerial features for UAV accessing via E-UTRA reuses the existing mechanism defined in TS 36.300.
• One or more USS(s) may be present in a specific region and may manage UAVs over one or more 3GPP networks.
• The 3GPP Network subscription for the UAV is not assumed to contain any information about the USS.
• The USS address(es), if known to the UAV, is/are configured in the UAV via mechanisms outside the scope of 3GPP. Multiple USS addresses may be configured/provisioned to UAV in case that multiple USSs are deployed in a geographic area and may serve the UAV flight path.
• For PC5, Release 15 (and later) version of the specification is the baseline.