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.

Abstract: A method for UE-to-UE (U2U) relay discovery security is disclosed. The method may comprise provisioning an end-UE with security material for a direct discovery set and a U2U discovery message and provisioning a U2U relay with security material for the U2U discovery message. The security material for the direct discovery set may comprise at least one of: A ProSe restricted code, associated key material, or an indicator associated with a relay service code (RSC) that indicates whether the RSC supports per ProSe direct discovery set protection. The method may comprise sending, by the end-UE to the U2U relay, a direct connection request (DCR) message. The DCR message may comprise at least one of: an RSC, and end-UE User info identification (ID), or a ProSe restricted code. The method may comprise sending, by the end-UE, an indication for direct discovery set protection.

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

Abstract: A Relay node may detect conflicts regarding media access control (MAC) addresses. A relay node may receive a request to establish a link with a source node. The relay node may receive the MAC address of the source node. The relay node may detect a conflict associated with the MAC address of the source node. The relay node may reject the request to establish the link with the source node.

Abstract: A relay node may detect conflicts regarding media access control (MAC) addresses. The relay node may receive a request to establish a links with a source node and a target node. The relay node may receive the MAC addresses of the source node and the target node. The relay node may detect a conflict associated with the MAC addresses of the source node and the target node. The relay node may release the link with the target node.

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 concealing a subscription identifier. The subscription identifier may be padded with a random number of characters. The padding may use characters not usable for the subscription identifier. The padded subscription identifier may be encrypted and output, possibly with an indication of the padding method used and, in an embodiment, an indication of the number of padding characters. The subscription identifier may be a user identifier, e.g., in a 5G network in which a wireless transmit/receive unit can conceal its identifier.

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: A method for use in wireless transmit/receive unit (WTRU) which assesses both a first network and a second network to receive radio frames from each of the first network and the second network is disclosed. The method comprise: obtaining a first paging occasion (PO) as the first network's current PO and a second PO as the second network's current PO; determining whether there is a PO collision between the first PO and the second PO, on condition that there is the PO collision, selecting a network from the first network and the second network, and sending a request to the selected network; receiving, from the selected network, a collision avoidance parameter corresponding to the request; calculating a third PO for the selected network using the collision avoidance parameter, and using the third PO as the selected network's current PO.

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: A system, method, and/or device for relay communications are provided. In some implementations, a method implemented by a WTRU may include sending a Link Modification Request (LMR) message to a second WTRU via a first relay, wherein the LMR message includes one or more new most significant bytes (MSBs) for a new Key NR ProSe identifier (KNRP ID), receiving a link modification accept (LMA) message from the second WTRU via a first relay, where the LMA message includes one or more new least significant bytes (LSBs) for the new KNRP ID, forming 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 device may include sending a direct connection request (DCR) message to the second WTRU via a second relay, where the DCR message includes the new KNRP ID.

Abstract: Methods and apparatuses for power saving are described herein. A method performed by a remote wireless transmit/receive unit (WTRU) may include receiving a broadcast message indicating a power saving capability, sending, to a relay WTRU, a request for direct communication, receiving an acknowledgement from the relay WTRU in response to the request for direct communication, and establishing a link to the relay WTRU based on the received acknowledgement. The method may further include sending, to the relay WTRU, a message for registration with a network, receiving, via the relay WTRU, a message from the network in response to the message for registration, sending, to the relay WTRU, a message indicating that a power saving feature is enabled, and adjusting parameters for power saving. The request for direct communication may include information indicating one or more power saving capabilities or power saving requirements of the remote WTRU.

Abstract: V2X Enhancements to support V2P communication are disclosed. In particular, Vehicle to Pedestrian Communications are provided. Methods and apparatus for direct link with a peer WTRU using a first key identifier of a root key are provided. In an 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 a response to the release request message including second security information associated with the second key identifier of the root key. The method also includes determining the second key identifier of the root key using the first security information and the second security information; and sending a message including information indicating the second key identifier of the root key.

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 method for UE-to-UE (U2U) relay discovery security is disclosed. The method may comprise provisioning an end-UE with security material for a direct discovery set and a U2U discovery message and provisioning a U2U relay with security material for the U2U discovery message. The security material for the direct discovery set may comprise at least one of: A ProSe restricted code, associated key material, or an indicator associated with a relay service code (RSC) that indicates whether the RSC supports per ProSe direct discovery set protection. The method may comprise sending, by the end-UE to the U2U relay, a direct connection request (DCR) message. The DCR message may comprise at least one of: an RSC, and end-UE User info identification (ID), or a ProSe restricted code. The method may comprise sending, by the end-UE, an indication for direct discovery set protection.

Abstract: In examples, the E2E link IDs may be isolated per-hop, so that changes of link IDs may not impact other E2E/per-hop links (e.g, a LIU procedure may only run between a WTRU and the relay), A relay may allocate R-specific security IDs/session key identifiers (e.g, MSBs/LSBs of Knrp-sess ID), The relay (e.g., relay WTRU) may replace the security IDs/session key identifiers received from peer WTRUs with R-specific security IDs/session key identifiers, for example, If forwarding a message. In examples, per-hop IDs and E2E IDs may be added to link identifier update messages, In examples, the support application layer ID and iP address/prefix may be changed using a link modification procedure (e.g.