Abstract: A method and device are disclosed for a relay User Equipment (UE). In one embodiment, the relay UE establishes a first layer-2 link with a first remote UE. The relay UE also establishes a Protocol Data Unit (PDU) session with a network, wherein the relay UE forwards traffic of the first remote UE on the PDU session. The relay UE further establishes a second layer-2 link with a second remote UE. In addition, the relay UE forwards traffic of the second remote UE on the PDU session. Furthermore, the relay UE receives a network control signaling from the network, wherein the network control signaling is associated with the first remote UE and is used for modifying the PDU session. The relay UE also initiates a layer-2 link modification procedure toward the first remote UE in response to reception of the network control signaling.

Abstract: A method and device for a first User Equipment (UE) are disclosed. In one embodiment, the first UE establishes a PC5 connection with a second UE for supporting a UE-to-UE (U2U) relay communication. The first UE also sends to the second UE a message to trigger a negotiated relay reselection, wherein the message includes a relay reselection indication information element (IE) and a link modification operation code IE set to a specific value.

Abstract: Methods, systems, and apparatuses are provided for relay User Equipment (UE) supporting candidate UE-to-UE (U2U) relay discovery, wherein a method for a relay UE comprises receiving, from a target end UE, a discovery solicitation message for candidate U2U relay discovery, and determining to transmit a discovery response message to the target end UE, in response to reception of the discovery solicitation message for candidate U2U relay discovery, wherein the discovery response message indicates the discovery response message being used for candidate U2U relay discovery by at least setting an application layer Identification (ID) indicated in the discovery response message to a specific value.

Abstract: Methods, systems, and apparatuses are provided for sending notification messages in multi-hop User Equipment (UE)-to-network (U2N) relay communications by intermediate relays in a wireless communication system, wherein a method comprises establishing a first PC5 connection with a remote UE for supporting a U2N relay communication between the remote UE and a network via the first relay UE and a second relay UE, establishing a second PC5 connection with the second relay UE for supporting the U2N relay communication, wherein the first relay UE is served by a first cell, detecting a PC5 Radio Link Failure (RLF) on the second PC5 connection or receiving a notification message indicating RLF of a Uu link from the second relay UE, performing a Radio Resource Control (RRC) connection re-establishment procedure to the network, omitting a transmission of a PC5-RRC message or not transmitting the PC5-RRC message to the remote UE if at least the first relay UE keeps being served by the first cell or a serving cell of the

Abstract: A method and device for a relay User Equipment (UE) are disclosed. In one embodiment, the relay UE establishes a first UE-to-UE (U2U) relay communication between a source end UE and a first target end UE and a second U2U relay communication between the source end UE and a second target end UE. The relay UE also sends a PC5 Radio Resource Control (RRC) message to the source end UE, wherein the PC5 RRC message includes a list information indicating at least one of a first mapping of a first local UE Identity (ID) and a first layer-2 ID for the first target end UE and a second mapping of a second local UE ID and a second layer-2 ID for the second target end UE.

Abstract: A method and device for a first User Equipment (UE) are disclosed. In one embodiment, the first UE establishes a PC5 connection with a second UE for supporting a UE-to-UE (U2U) relay communication. The first UE also sends to the second UE a message to trigger a negotiated relay reselection, wherein the message includes a relay reselection indication information element (IE) and a link modification operation code IE set to a specific value.

Abstract: A method and device for a relay User Equipment (UE) are disclosed. In one embodiment, the relay UE establishes a first direct link with a source end UE and a second direct link with a target end UE for supporting UE-to-UE (U2U) relay communication between the source end UE and the target end UE via the relay UE. The relay UE also receives a first link identifier update request message from the source end UE for updating a first user info of the source end UE to a second user info of the source end UE. Furthermore, the relay UE, in response to reception of the first link identifier update request message, performs a first relay update procedure with the target end UE.

Abstract: A method and device for a relay User Equipment (UE) are disclosed. In one embodiment, the relay UE establishes a first direct link with a source end UE and a second direct link with a target end UE for supporting UE-to-UE (U2U) relay communication between the source end UE and the target end UE via the relay UE. The relay UE also receives a first link identifier update request message from the source end UE for updating a first user info of the source end UE to a second user info of the source end UE. Furthermore, the relay UE, in response to reception of the first link identifier update request message, performs a first relay update procedure with the target end UE.

Abstract: Methods, systems, and apparatuses are provided for target end User Equipment (UE) supporting candidate UE-to-UE (U2U) relay discovery in a wireless communication system, wherein a method for a target end UE comprises establishing a connection with a relay UE for supporting U2U relay communication between a source end UE and the target end UE via the relay UE, receiving a link modification request message indicating a list of candidate relay UEs from the relay UE for performing negotiated relay reselection, determining to transmit a discovery solicitation message to a candidate relay UE among the list of candidate relay UEs, wherein the discovery solicitation message indicates the discovery solicitation message being used for candidate U2U relay discovery by at least setting an application layer Identification (ID) indicated in the discovery solicitation message to a specific value, receiving, from the candidate relay UE, a discovery response message for candidate U2U relay discovery, and transmitting a link m

Abstract: Methods, systems, and apparatuses are provided for relay User Equipment (UE) supporting candidate UE-to-UE (U2U) relay discovery, wherein a method for a relay UE comprises receiving, from a target end UE, a discovery solicitation message for candidate U2U relay discovery, and determining to transmit a discovery response message to the target end UE, in response to reception of the discovery solicitation message for candidate U2U relay discovery, wherein the discovery response message indicates the discovery response message being used for candidate U2U relay discovery by at least setting an application layer Identification (ID) indicated in the discovery response message to a specific value.

Abstract: Methods, systems, and apparatuses are provided for target end User Equipment (UE) supporting candidate UE-to-UE (U2U) relay discovery in a wireless communication system, wherein a method for a target end UE comprises establishing a connection with a relay UE for supporting U2U relay communication between a source end UE and the target end UE via the relay UE, receiving a link modification request message indicating a list of candidate relay UEs from the relay UE for performing negotiated relay reselection, determining to transmit a discovery solicitation message to a candidate relay UE among the list of candidate relay UEs, wherein the discovery solicitation message indicates the discovery solicitation message being used for candidate U2U relay discovery by at least setting an application layer Identification (ID) indicated in the discovery solicitation message to a specific value, receiving, from the candidate relay UE, a discovery response message for candidate U2U relay discovery, and transmitting a link m

Abstract: A method and device are disclosed for paging reception via UE-to-Network Relay. In one embodiment, the method includes a UE being enabled to use layer-2 type UE-to-Network (U2N) Relay. The method also includes the UE discovering one or more relay UEs in response to enabling of using layer-2 type U2N Relay. Furthermore, the method includes the UE selecting a relay UE from the one or more relay UEs. In addition, the method includes the UE establishing a layer-2 link with the relay UE. The method also includes the UE receiving paging information for the UE from the relay UE over the layer-2 link.

Abstract: A method and device for a relay User Equipment (UE). In one embodiment, the relay UE receives a first PC5 message from a first remote UE for initiating a first direct link establishment procedure for a UE-to-UE (U2U) relay communication with a second remote UE. Furthermore, the relay UE, in response to reception of the first PC5 message, sends a second PC5 message for initiating a second direct link establishment procedure for the U2U relay communication with the first remote UE. In addition, the relay UE sends a reject message corresponding to the first PC5 message to the first remote UE if the second direct link establishment procedure is not completed within a period.

Abstract: A method and device for a first end User Equipment (UE) are disclosed. The first end UE establishes a PC5 connection with a relay UE for supporting a UE-to-UE relay communication between the first end UE and a second end UE via the relay UE. The first end UE establishes an end-to-end Sidelink (SL) Data Radio Bearer (DRB) and associates the end-to-end SL DRB with a first PC5 Relay Radio Link Control (RLC) channel for supporting the UE-to-UE relay communication. In addition, the first end UE modifies the end-to-end SL DRB to associate it with a second PC5 Relay RLC channel for supporting the UE-to-UE relay communication. Furthermore, the first end UE, in response to the modification of the end-to-end SL DRB, performs PC5 Relay RLC channel release for the first PC5 Relay RLC channel.

Abstract: A method and device for a first end User Equipment (UE) are disclosed. The first end UE establishes a PC5 connection with a relay UE for supporting a UE-to-UE relay communication between the first end UE and a second end UE via the relay UE. The first end UE establishes a first end-to-end Sidelink (SL) Data Radio Bearer (DRB) and associates the first end-to-end SL DRB with a first PC5 Relay Radio Link Control (RLC) channel for supporting the UE-to-UE relay communication, wherein the first PC5 Relay RLC channel is established between the first end UE and the relay UE. The first end UE establishes a second end-to-end SL DRB and associates the second end-to-end SL DRB with a second PC5 Relay RLC channel for supporting the UE-to-UE relay communication, wherein the second PC5 Relay RLC channel is established between the first end UE and the relay UE.

Abstract: A method and apparatus are disclosed from the perspective of a first device. In one embodiment, the method includes the first device performs sensing on a data resource pool, and the first device selects/derives at least a first data resource from the data resource pool based on the sensing result of the data resource pool. The method further includes the first device transmits a first control information on a first control resource, wherein the first control information allocates or indicates the first data resource. The method also includes the first device performs a first data transmission on the first data resource to at least one second device.

Abstract: A method and device are disclosed for paging reception via UE-to-Network Relay. In one embodiment, the method includes a UE being enabled to use layer-2 type UE-to-Network (U2N) Relay. The method also includes the UE discovering one or more relay UEs in response to enabling of using layer-2 type U2N Relay. Furthermore, the method includes the UE selecting a relay UE from the one or more relay UEs. In addition, the method includes the UE establishing a layer-2 link with the relay UE. The method also includes the UE receiving paging information for the UE from the relay UE over the layer-2 link.

Abstract: The first UE establishes a PC5 connection with a relay UE for supporting a relay communication between the first UE and a second UE via the relay UE, wherein a direct link context associated with the relay communication includes a layer-2 Identity (ID) of the second UE. The first UE initiates a link identifier update (LIU) procedure with the second UE via the relay UE, wherein the first UE receives a LIU response message from the second UE in the LIU procedure, and the LIU response message includes a new layer-2 ID of the second UE. The first UE does not update the direct link context with the new layer-2 ID of the second UE or the first UE keeps the layer-2 ID of the second UE in the direct link context without updating the direct link context with the new layer-2 ID of the second UE.

Abstract: A method and device for a User Equipment (UE) for connecting with a network are disclosed. In one embodiment, the UE delivers a first Protocol Data Unit (PDU) of a first PDU set from a Quality of Service (QoS) flow to a first Data Radio Bearer (DRB). The UE also receives a message or an indication from the network for remapping the QoS flow from the first DRB to a second DRB. Furthermore, the UE delivers a second PDU of the first PDU set to the first DRB, wherein the second PDU is delivered to the first DRB after receiving the message or the indication.

Abstract: A method and apparatus are disclosed from the perspective of a first device to perform sidelink communication. In one embodiment, the method includes the first device performing sidelink resource selection or reselection procedure for a sidelink transmission to a second device, wherein the sidelink resource selection or reselection procedure is performed to select at least one sidelink resource from candidate sidelink resources within a time duration of selection window. The method further includes the first device selecting a first sidelink resource based on sidelink active time or wake-up time of the second device, wherein the first sidelink resource is within the time duration of selection window. The method also includes the first device performing the sidelink transmission on the first sidelink resource to the second device.