Abstract: Methods and apparatuses are described herein for paring an unmanned aerial vehicle (UAV) with a UAV-controller (UAV-C). For example, a UAV having a UAV wireless transmit/receive unit (UAV WTRU) may transmit, to an access and mobility management function (AMF), a non-access stratum (NAS) request message that includes a paring request indication and a UAV-controller (UAV-C) identification (UAV-C ID). The UAV-C ID may be carried in a paring request to an unmanned aerial system (UAS) service supplier (USS)/UAS traffic management (UTM) for paring authorization of the UAV with a UAV-C associated with the UAV-C ID. The UAV may receive, from the AMF, a NAS response message that includes an unmanned aerial system (UAS) identification (UAS ID) indicating that the UAV is paired with the UAV-C, wherein the UAS ID is assigned by the USS/UTM.

Abstract: In an implementation, a second device, for example a second WTRU, may receive a Link Modification Request (LMR) message from a first device, for example a first WTRU, via a first relay. The LMR message may include one or more new MSBs for a new Key NR ProSe identifier (KNRP ID). The second WTRU may send a link modification accept (LMA) message to the first WTRU via the first relay. The LMA message may include one or more new LSBs for the new KNRP ID. The second WTRU may form the new KNRP ID by combining the one or more new MSBs with the one or more new LSBs and replacing an existing KNRP ID with the new KNRP ID. The second WTRU may also receive a direct connection request (DCR) message from the first WTRU via a second relay. The DCR message may include the new KNRP ID.

Abstract: Methods, devices, and systems for changing a layer 2 (L2) identifier (ID) during an ongoing vehicle-to-everything (V2X) session between a source wireless transmit/receive unit (WTRU) and a peer WTRU include communicating between the source and a peer WTRUs based on an existing layer 2 (L2) identifier (ID). On a condition that a trigger event occurs, the source WTRU generates a new source L2 ID, communicates the new source L2 ID to the peer WTRU, receives from the peer WTRU a message that responds to the new source L2 ID, and communicates between the source WTRU and the peer WTRU based on the new source L2 ID.

Abstract: Systems and methods are described herein for handling connection rejects via a wireless transmit/receive unit (WTRU)-to-WTRU (U2U) relay associated with backoff times on behalf of a source end WTRU. A relay WTRU may retry to establish connection with a target WTRU on behalf of a source WTRU, for example, based on receiving a rejection (e.g., with a backoff value) from the target WTRU. The source WTRU may associate the reject message to the target WTRU, and the relay WTRU may be available to reach other target WTRUs. The relay WTRU may send a reject message to other source WTRUs (e.g., if the back off duration is active, running) for the same target WTRU.

Abstract: Procedures, methods, architectures, apparatuses, systems, devices, and computer program products directed to methods, architectures, apparatuses, systems directed for associating single-modal flows for synchronization and resource allocation.

Abstract: Systems, methods, and instrumentalities are disclosed that are associated with cellular communications for unmanned aerial vehicles and associated devices. A WTRU may initiate multiple PDU sessions. The WTRU may initiate a first protocol data unit (PDU) session. The WTRU may receive one or more session parameters for a second PDU session. The one or more session parameters for the second PDU session may be received via the first PDU session. The WTRU may initiate the second PDU session using the one or more session parameters (e.g., based on an authentication and authorization associated with the first PDU session being successful). The WTRU may send or receive an operation communication via the second PDU session. The operation communication may comprise an unmanned aerial vehicle command and control message or an unmanned aerial vehicle payload message.

Abstract: A method implemented in a Wireless Transmit Receive Unit (WTRU) for controlling resource usage associated with delivery of training results for a machine learning (ML) operation includes receiving one-way packet delay measurements between the WTRU and an Application Server or Application Function (AS/AF), predicting one or more upcoming one-way packet delays using the one-way packet delay measurements, determining whether the WTRU is capable of processing and delivering training results of the ML operation to the AS/AF within a specified time period based on the predicted upcoming one-way packet delays, and initiating one of a packet data unit session (PDU) release procedure or a PDU session modification procedure.

Abstract: Method, apparatus and systems are disclosed that may be implemented in wireless transmit/receive unit (WTRU), an unmanned aerial vehicle (UAV) and/or a UAV-controller (UAV-C). In one representative method, the UAV may switch from a first Command and Control (C2) communication link between a UAV and a first UAV-C to a second C2 communication link for C2 communications. The method may include determining, by the WTRU, to switch C2 communications from the first C2 communication link to the second C2 communication link based on a C2 switching condition; sending, by the WTRU to a C2 control entity, a notification indicating link information used to determine switching from the first C2 communication link to the second C2 communication link; receiving, by the WTRU from the C2 control entity, information indicating a switch; and switching, by the WTRU, C2 communications from the first C2 communication link to the second C2 communication link.

Abstract: V2X Enhancements to support V2P communication are disclosed. In particular, Vehicle to Pedestrian Communications are provided. Methods and apparatus for operation by an initiating wireless transmit/receive unit (WTRU) for direct link with a peer WTRU using a first key identifier of a root key are provided. In one embodiment, a method includes sending, by the initiating WTRU to the peer WTRU, a release request message to release the direct link with the peer WTRU, the release request message including information indicating first security information associated with a second key identifier of the root key. The method further includes receiving, receiving, by the initiating WTRU from the peer WTRU, a response to the release request message including second security information associated with the second key identifier of the root key.

Abstract: In an embodiment, a wireless transmit receive unit (WTRU) includes a processor configured to receive configuration information that includes information related to S-NSSAI support for each visited public land mobile network (VPLMN) of a plurality of VPLMNs, to receive a message indicating that an S-NSSAI is not available on a current VPLMN, and to send a request message including an indication that the S-NSSAI is not available in the current VPLMN, the request message being one of a deregistration message and a registration request message based on the configuration information.

Abstract: A relay node may detect conflicts regarding media access control (MAC) addresses. A source node may send a request to the relay node. The request may be a request to establish communications with a target node. The source may send, to the relay node, an indication of the MAC address of the source node. The source node may receive a reject message from the relay node. The reject message may comprise an indication of a conflict associated with the MAC address of the source node.

Abstract: Procedures, methods, architectures, apparatuses, systems, devices, and computer program products for a wireless transmit/receive unit (WTRU) to determine slice availability in tracking areas (TAs) of a registration area (RA). In a representative example, the WTRU may use determined slice availability to detect changes in slice availability among different TAs. For example, the WTRU may move from a first TA of a RA where access to a first slice is unavailable to a second TA of the RA where access to the first slice is available. The WTRU may receive information during a registration procedure in the first TA that indicates the first slice is available in less than all TAs of the RA. Upon moving to the second TA, the WTRU may (e.g., again) perform a registration procedure in the second TA of the RA in order to access the first slice in the second TA.

Abstract: A relay WTRU may establish a connection between a first and a second WTRU. The relay WTRU may include sending, to the second WTRU, a LMR message received from the first WTRU, the LMR message including a request for a release of the connection, and sending, to the first WTRU, a LMA message received from the second WTRU, where the LMA message includes an acceptance of the release of the connection, The relay WTRU may include sending, to the second WTRU, a link release request message received from the first WTRU including one or more new MSBs of a new KNRP ID and sending, to the first WTRU, a link release response message received from the second WTRU, the link release response message including one or more new LSBs of the new KNRP ID, where the new KNRP ID is formed by combining the new MSBs and the new LSBS.

Abstract: Systems and methods are described herein for enabling discovery and selection of a WTRU-to-network relay by a remote WTRU and handling a WTRU-to-network relay configuration update. The WTRU-to-network relay may broadcast a service type indicating that the service type is available or conditionally available based on the WTRU-to-network relay slicing configuration. The WTRU-to-network relay may update broadcasting the service type or the indication that the service type as being conditionally available based on update of the WTRU-to-network relay slicing configuration. The WTRU-to-network relay may relay traffic between one or more distinct remote WTRUs and the core network node via a WTRU-to-network relay. The WTRU-to-network relay may reuse an existing PDU session for relay traffic or send a PDU session establishment request to network with the requested PDU session parameters depending on if the session parameters associated with an existing PDU session match the PDU session requirements of the remote WTRU.

Abstract: Systems and methods for supporting multiple uncrewed aerial vehicle (UAV) Service Suppliers (multi-USS) are described. The methods may be performed by a wireless transmit/receive unit (WTRU) including a UAV application enabling (UAE) client located in the UAV with the method performed with the UAV in-flight. Steps may include: sending a registration request to a UAE server, the registration request including an indication of multi-USS capability; receiving a registration response message that includes an indication that the UAE server supports multi-USS capability; receiving a multi-USS configuration request that includes multi-USS configuration parameters related to conditions under which the UAE client may initiate a USS change and a list of allowed USSs; sending a multi-USS configuration response; and performing a multi-USS change and sending a multi-USS change notification based on the multi-USS configuration parameters.

Abstract: Methods and apparatuses directed to non-access stratum procedures in connection with layer 2 relaying are provided. A method implemented in a first WTRU, may comprise: receiving, from a second WTRU, a first sidelink transmission comprising a first information indicating an amount of time for the first WTRU to refrain from transmitting, to the second WTRU; determining to reselect to a third WTRU responsive to receiving the first information and based on a second sidelink transmission from the third WTRU; reselecting or autonomous reselecting to the third WTRU; establishing a connection with the third WTRU; and transmitting, to the third WTRU, a third sidelink transmission comprising a second information indicating congestion as a cause for the reselection.

Abstract: A wireless transmit receive unit (WTRU) may be configured to transmit on a first interface and determine to transmit on a second interface. The WTRU may receive configuration information. For example, the configuration information may include a path switching capability indication, a path switching policy, and an information sharing method indication. Based on the configuration information, the WTRU may determine to perform a path switch. In response to determining to perform a path switch, the WTRU may retrieve certain information associated with a peer WTRU. The WTRU may transmit, based on the retrieved information, a path switch request to the peer WTRU. The WTRU may receive a response to the path switch request. If the response indicates that the path switch request has been accepted by the peer WTRU, the WTRU may perform a communication path switch from the first interface to a second interface.

Abstract: A method for slice authentication in a mobile telephone network. A WTRU performs, during a registration procedure with an Access and Mobility management Function, AMF, of a network, primary authentication of the WTRU, during which registration procedure the WTRU receives from the AMF a message indicating successful registration and including at least one of an indication of at least one network slice-specific authentication and authorization for slice access, SSSA, procedure to be executed following the registration procedure, a list of slices for which the WTRU is allowed access, and a list of slices for which SSSA is needed for access by the WTRU, and performs, after successful registration, at least one SSSA of the WTRU for accessing a first slice in the network.

Abstract: A method and apparatus where an announcing WTRU may request peer discovery from a Pro Se function, and the ProSe function may provide information associated with a monitoring WTRU to the announcing WTRU as a result of the monitoring WTRU having discovered the announcing WTRU. A discoveree WTRU may request peer discovery from a ProSe function where the ProSe function sends a unique ProSe query code to a discoverer WTRU. As a result of the discoveree WTRU detecting the ProSe query code on radio interface, the discoveree WTRU triggers a match report procedure to obtain information associated with the Discoverer WTRU.

Abstract: Systems and methods are described herein for enabling discovery and selection of a WTRU-to-network relay by a remote WTRU and handling a WTRU-to-network relay configuration update. The WTRU-to-network relay may broadcast a service type indicating that the service type is available or conditionally available based on the WTRU-to-network relay slicing configuration. The WTRU-to-network relay may update broadcasting the service type or the indication that the service type as being conditionally available based on update of the WTRU-to-network relay slicing configuration. The WTRU-to-network relay may relay traffic between one or more distinct remote WTRUs and the core network node via a WTRU-to-network relay. The WTRU-to-network relay may reuse an existing PDU session for relay traffic or send a PDU session establishment request to network with the requested PDU session parameters depending on if the session parameters associated with an existing PDU session match the PDU session requirements of the remote WTRU.