Abstract: The disclosure pertains to methods and apparatus for minimization of service interruption in wireless networks, such as 5G networks. According to an embodiment, a method, implemented in a wireless transmit/receive unit, WTRU, comprises: transmitting, to a second network, first information indicating a request to register with the second network, wherein the first information comprises information indicating an identity of a first network to which the WTRU is currently registered; receiving, from the second network, second information indicating an acceptance of registration to the second network, wherein the second information comprises information indicating a maximum amount of PDU sessions, wherein the maximum amount corresponds to a limit of allowable PDU sessions; and transmitting, to the second network, third information indicating a request to establish a second amount of PDU sessions no more than the limit of allowable PDU sessions.

Abstract: Method and apparatus for secure access control in wireless communications are disclosed. In an example, a method includes receiving a broadcast message including system information, identifying a first set of hashed identifiers (IDs) and a first random number based on the system information, and each ID of the first set of hashed IDs is individually hashed using at least the first random number. The method also includes calculating a first hash value for each ID of a second set of IDs using at least the first random number, determining whether at least a hashed ID of the second set of IDs matches a hashed ID of the first set of hashed IDs, and sending a request message based on a determination that at least a hashed ID of the second set of IDs matches a hashed ID of the first set of hashed IDs.

Abstract: The disclosure pertains to methods and apparatus for supporting multiple application IDs on a single unicast link using Layer-3 Relay. Methods and apparatus for operation by a wireless transmit/receive unit (WTRU) are provided. In an embodiment, a method may include any of receiving a first request message to establish a direct communication with a peer WTRU, the request message including an indication of first user information of the peer WTRU, associated with a first application and/or a first application identity; transmitting, to the peer WTRU, information indicating a first Internet Protocol (IP) address; receiving a second request message to associate a second application with the direct communication; transmitting a second response message including a second IP address; and communicating, with the peer WTRU using the direct communication, data related to the first application using the first IP address and data related to the second application using the second IP address.

Abstract: A wireless transmit/receive unit (WTRU) may receive a power reporting policy from a network node. The power reporting policy may include one or more triggers associated with sending a power status report. The WTRU may determine that a trigger of the one or more triggers associated with sending the power status report has been satisfied. The WTRU may send the power status report to the network node in accordance with the power reporting policy. The power status report may include power status information associated with the WTRU and/or an indication that indicates the determined trigger to send the power status report.

Abstract: A method performed by a network node for storing a context for at least one unmanned aerial system includes receiving a notification including information indicative of an identifier of an unmanned aerial system and of a change of serving anchor node for the unmanned aerial system corresponding to the identifier from a first anchor node to a second anchor node. The stored context is updated for the unmanned aerial system where the stored context includes a serving anchor node for the unmanned aerial system to indicate the second anchor node as the serving anchor node.

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: Methods, apparatus and systems are disclosed. In one embodiment, a method, implemented by a Wireless Transmit/Receive Unit (WTRU) registered to a first network, includes receiving, from the first network, information indicating a value to be used during a registration to a second network; and determining, based on at least the indicated value, at least a first start time and a second start time from which to perform the registration to the second network. The method further includes initiating the registration to the second network after the first start time; and on condition that the registration is not completed within a defined period after the first start time: (1) halting the registration to the second network, and (2) initiating a second registration or re-registration of the WTRU to the second network after the second start time.

Abstract: A wireless transmit-receive unit (WTRU) may be provided. The WTRU may be configured to receive a first message from a first relay WTRU. The first message may indicate a service provided by a second WTRU and a first measurement associated with a broadcast message. The WTRU may be configured to determine a second measurement. The second measurement may be associated with the first message received from the first relay WTRU. The WTRU may be configured to send a second message to the first relay WTRU if the first measurement satisfies a first criteria for selecting a relay from a plurality of relays and the second measurement satisfies a second criteria for selecting the relay from the plurality of relays. The second message may comprise an indication to establish communication between the first WTRU and the second WTRU via the first relay WTRU.

Abstract: Methods, apparatus, and systems for a wireless transmit receive unit (WTRU) performing relay communications are provided. A method may include receiving a first message indicating: (1) a first security policy associated with a first data link, and (2) a maximum data rate for integrity protection (MDRIP) supported by the remote WTRU; transmitting, to a network, a second message indicating: (1) an MDRIP supported by the remote WTRU or by the relay WTRU, and (2) a request for PDU session establishment; receiving, from the network, a third message indicating a second security policy for a second data link; and establishing the first data link with the remote WTRU on the condition that an end-to-end (e2e) security policy is compatible with the second security policy, wherein the e2e security policy is determined according to the second security policy and a UP security policy of the relay WTRU.

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: A relay WTRU may receive, from a remote WTRU, a request for connection that includes a PRUK ID. The relay WTRU may transmit, to a PKMF associated with the relay WTRU, a key request message that includes the PRUK ID. The relay WTRU may receive, from the PKMF associated with the relay WTRU, a key response message that includes a GPI. The relay WTRU may transmit, to the remote WTRU, a direct security mode command message that includes the GPI. The relay WTRU may receive, from the remote WTRU, a direct security mode complete message. The relay WTRU may transmit, to the PKMF associated with the relay WTRU, a PRUK confirmation message. The relay WTRU, may receive, from the PKMF associated with the relay WTRU, an acknowledgement that the PRUK confirmation message was received, and transmit, to the second WTRU, an acceptance of the request for connection.

Abstract: Methods, apparatuses, systems, etc., directed to performing a change of relay are disclosed herein. In an embodiment, a WTRU may transmit a link modification request message to a target WTRU via a first relay WTRU for requesting a change of relay. The WTRU may receive a link modification accept message from the target WTRU via the first relay WTRU, indicating a (e.g., proposed) second relay WTRU (e.g., identifier). The WTRU may transmit a direct communication request message including the second relay WTRU identifier for indicating to the target WTRU acceptance of the proposed second relay WTRU. The WTRU may a receiving a direct communication accept message from the target WTRU via the second relay WTRU, indicating the traffic may be relayed via the second relay WTRU.

Abstract: Methods, apparatus, systems, architectures and interfaces for performing secure command and control (C2) communications in an Unmanned Aerial System (UAS) including a UAV controller (UAV-C) are provided. The method includes on condition that the UAV has completed a registration procedure with a network, transmitting, to a session management function (SMF) of the network, a packet data unit (PDU) session establishment request message; performing a secondary authentication, with any of the USS and the UTM, via the SMF; receiving a PDU session establishment accept message including C2 security information; and establishing C2 communications security with the peer UAV-C using the C2 security information.

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: 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: An unmanned aerial vehicle (UAV) authentication and authorization may be performed by a third-party service provider (e.g., an unmanned aerial system traffic management (UTM) over a user plane (UP)). An UAV may be configured to send an UAV ID to a network. The UAV may receive, from the network, security information that indicates an authorization of a connection to a third-party service provider. The UAV may establish, based on the security information, the connection to the third-party service provider for communications with the third-party service provider. The security information may include signature information of the third-party service provider, and one or more of a subscription identifier (ID) associated with the UAV, the UAV ID, or an ID of the third-party service provider.

Abstract: A method for changing layer 2 (L2) identifiers (ID)s during an ongoing vehicle-to-everything session between a source wireless transmit/receive unit (WTRU) and a peer WTRU includes communicating between the source and a peer WTRUs based on existing L2 IDs and an existing session ID. On a condition that a trigger event occurs, the source WTRU and the peer WTRU each generate new L2 IDs as well as respective portions of a new session ID. The new L2 IDs are subsequently used along with the new session ID to increase privacy of communication between the source WTRU and the peer WTRU.

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: Systems, methods and instrumentalities are described herein that provide security and/or privacy support for wireless transmit receive units (WTRUs) communicating via a WTRU to WTRU relay. A source WTRU may obtain a new IP address from a relay WTRU via a link identifier update request. The source WTRU may indicate to the relay WTRU which one or more target WTRUs are to be informed of the new IP address. The source WTRU may indicate to the relay WTRU whether the target WTRU's ID(s) should be changed. The relay WTRU may send the source WTRU's new IP address to authorized target WTRUs. The source, relay, and target WTRU may use tokens to grant or receive authorizations for sharing each other's IP addresses.

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.