Abstract: Systems, methods, and instrumentalities are disclosed herein associated with robust handover (HO) via sidelink (SL) relays. A remote wireless transmit/receive unit (WTRU) may be used in HO scenario from a source network node (e.g., gNB) to a neighbor or target network node (e.g., gNB). For example, the HO procedure may include a remote WTRU determining whether condition(s) (e.g., measurement reporting condition or sidelink connection establishment condition (e.g., event condition)) are satisfied. The remote WTRU may establish a sidelink connection with a relay candidate, for example, during the HO procedure.

Abstract: Disclosed procedures, methods, architectures, apparatuses, systems, devices, and computer program products relate to beam refinement in cellular communications. In exemplary implementations, configurations and methods for performing fast and early beam refinement during an initial channel access procedure are disclosed. In exemplary implementations, beam refinement is based on channel state information (CSI) measurements performed by User Equipment (UE) on reference signal beams transmitted in a cell of a wireless cellular network.

Abstract: Systems, methods, and instrumentalities are described herein for radio link failure (RLF) detection in scenarios where a remote WTRU is connected with the network via multipath link composed of a direct link and a relayed link (e.g., via a relay WTRU connected to the remote WTRU via a sidelink, SL). A remote WTRU may be configured to modify the RLF detection parameters 2024/030653 of the direct link (e.g., RLF timer and counter values) based on the conditions on the relayed link such as SL radio quality (e.g., SL RSRP, SL RSRQ, etc.,) or/and SL congestion (e.g., CBR, CR, etc.). A remote WTRU may be configured to modify the RLF detection parameters of the SL (e.g., maximum HARQ DTX value) based on the conditions on the direct link (e.g., RSRP, RSRQ, etc. ,) and/or SL congestion (e.g., CBR, CR, etc.).

Abstract: A wireless transmit/receive node (WTRU) may be configured to receive an announcement message from another WTRU; determine, based on the announcement message, a list of source WTRUs; receive a discovery message from a source WTRU; compare the source WTRU to the list of source WTRUs; and determine, based on the comparison, whether to forward the discovery message.

Abstract: A method implemented in a relay wireless transmit/receive unit WTRU may include receiving QoS information indicating a QoS profile and receiving bearer information indicating an end-to-end bearer from a source WTRU. The method may include determining a second packet delay budget (PDB) on a second hop for the end-to-end bearer and determining a first PDB on a first hop for the end-to-end bearer based on the second PDB and an end-to-end PDB. The method may include sending PDB information to the source WTRU indicating the first PDB. In a case where a first RLC channel established with a target WTRU corresponds to a second RLC channel configured for the QoS profile, the second PDB on the second hop may be determined to be a PDB associated with the first RLC channel, and the end-to-end bearer may be associated with the first RLC channel.

Abstract: Methods, architectures, apparatuses, and systems directed to configuration and quality of service (QOS) management for relays are described herein. In an embodiment, a source wireless transmit/receive unit (WTRU) may transmit, to a relay, information indicating an end-to-end packet delay budget (PDB) for a QoS flow. The source WTRU may receive, from the relay, first information indicating a first PDB value and second information indicating a second PDB value associated with the QoS flow. The source WTRU may establish a first radio link control (RLC) channel for a first hop associated with the first PDB value, establish a second RLC channel for the first hop associated with the second PDB value, and transmit a packet of the QoS flow using one of the first RLC channel or the second RLC channel based on a signal-quality measurement associated with the first hop.

Abstract: System, methods, and instrumentalities may be configured for QoS splitting in a relay wireless transmit receive unit (WTRU). A first WTRU (e.g., a relay WTRU) may receive configuration information that indicates Packet Delay Budget (PDB) split information. The first WTRU may receive from a second WTRU (e.g., a source WTRU) a second WTRU channel busy ratio (CBR) and an End-to End (E2E) PDB associated with a Quality of Service (QoS) flow. The first WTRU may determine a first WTRU CBR and a first WTRU load. The first WTRU may determine a PDB split. The PDB split may be based on the PDB split information, the second WTRU CBR, the first WTRU CBR, and the first WTRU load. The first WTRU may send to the second WTRU an indication. The indication may indicate a PDB for a transmission from the second WTRU to the first WTRU.

Abstract: A method implemented in a relay WTRU is described herein. The method may include receiving first information from a network, the first information indicating a packet delay budget (PDB) condition for a second hop. The method may include receiving second information from the network, the second information indicating a PDB compensation. The method may include determining a second hop PDB based on measurements. The method may include determining that the second hop PDB fails to satisfy the condition, determining a second remaining PDB for a first hop based on the second hop PDB and the PDB compensation, and sending second PDB information to a source WTRU, the second PDB information indicating the second remaining PDB for the first hop.

Abstract: A method implemented in a source WTRU is described herein. The method may include determining whether to obtain information indicating a radio link control (RLC) channel configuration and a packet delay budget (PDB) for a QoS flow from a network or from a relay WTRU based on an allocation mode of the source WTRU. The method may include establishing an RLC channel on a first hop based on the RLC channel configuration. The method may include transmitting a packet of the QoS flow using the RLC channel.

Abstract: A method implemented in a wireless transmit/receive unit WTRU is described herein. The method may include sending QoS information to a relay WTRU, the QoS information indicating a first QoS profile for a QoS flow, the first QoS profile including a packet delay budget (PDB). The method may include receiving PDB information from the relay WTRU, the information indicating a first QoS PDB information indicating a split PDB for a first hop for the QoS flow. The method may include determining a first configuration for the QoS flow from the first QoS profile and determining a second configuration for the QoS flow from a second QoS profile. The second QoS profile may differ from the first QoS profile by including the split PDB. The method may include establishing a radio link control (RLC) channel with the first configuration and the second configuration and using the RLC channel to transmit data for the QoS flow.

Abstract: Systems, methods, devices, and instrumentalities are described herein related to resource selection for multiple destinations. A device (e.g., a wireless transmit/receive unit (WTRU)) may receive information that indicates a first packet delay budget (PDB) associated with a first relay WTRU and/or a second PDB associated with a second relay WTRU. The device may determine that there is data to be sent. The device may determine a resource selection window based on one condition of a first condition or a second condition being satisfied. The first condition may be satisfied if a congestion indication is received from the second relay WTRU and the second PDB is larger than the first PDB. The second condition may be satisfied if the congestion indication is not received from the second relay WTRU, the second PDB is larger than the first PDB, and a channel busy ratio (CBR) meets or is greater than a threshold.

Abstract: A method performed by a wireless transmit/receive unit (WTRU) includes receiving a cell discontinuous transmission (cell-DTX) configuration including active and inactive durations for the received cell-DTX configuration, receiving a first, a second, and a third connected WTRU DRX (C-DRX) cycle configurations, including an ON duration, periodicity, and start offset, and receiving signaling indicating that the cell-DTX configuration is activated in a serving cell of the WTRU. Thereafter, activating the third C-DRX cycle configuration associated with the activated cell-DTX configuration based on the signaling that the cell-DTX configuration is activated.

Abstract: A WTRU may be configured to receive a bearer configuration information. For example, the bearer configuration information may comprise at least one of: a configuration for a first bearer that is associated with a direct path, a configuration for a second bearer that is associated with an indirect path, and/or a configuration for a third bearer that is associated with the direct path and the indirect path. Each of the bearers may be associated with a priority. The WTRU may receive data at one of the second bearer or the third bearer. The WTRU may generate a flexible BSR MAC CE that includes an indication of the LCG and the buffer size. If the data is received at the second bearer, the LCG may be the second bearer's LCG identifier. If the data is received at the third bearer, the LCG may be the third bearer's LCG identifier.

Abstract: A wireless transmit/receive unit (WTRU) may determine that data associated with a RB is to be transmitted. For example, the RB may be capable of being used to transmit, via a sidelink (SL), an uplink (UL), or a combination of the SL and the UL, the data associated with the RB. The WTRU may determine whether a first triggering condition associated with an SL resource allocation for the data is satisfied. The first triggering condition may be that the WTRU has not received, before a delay time duration ends, one or more resource grants that allocate sufficient resources for the data. If the WTRU determines that a first triggering condition is satisfied, the WTRU may perform the SL resource allocation for the data associated with the RB. The WTRU may determine an SL resource to transmit the data, for example, by performing the SL resource allocation.

Abstract: A wireless transmit/receive unit (WTRU) may transmit data associated with a protocol data unit (PDU). The WTRU may receive a retransmission request for the data associated with the PDU. The WTRU may determine a retransmission scheme based on a triggering condition. The WTRU may send the data associated with the PDU using the determined retransmission scheme. For example, the WTRU may determine that a first triggering condition of multiple triggering conditions is satisfied. The first triggering condition may that the WTRU has retransmitted at least a threshold number of times. The WTRU may determine, based at least on the satisfaction of the first triggering condition, a retransmission scheme to send the data. The retransmission scheme may include a retransmission of the data associated with the PDU using a sidelink (SL) and an uplink (UL).

Abstract: Among the procedures, methods, architectures, apparatuses, systems, devices, and computer program products disclosed herein for multipath relaying isa wireless transmit/receive unit (WTRU) configured to: receive, from a network node, configuration information for configuring, by the WTRU, a multipath connection, the multipath connection comprising a direct path via a first link with the network node and an indirect path via a second link, the second link being a sidelink associated with a sidelink relay WTRU; receive, from the network node, first system information on a first serving cell, the first serving cell being associated with the direct path; receive, from the network node, a message to release the direct path; perform a serving cell change from the first serving cell to a second serving cell, the second serving cell being associated with the indirect path; and receive, from the sidelink relay WTRU, second system information of the second serving cell.

Abstract: A wireless transmit/receive unit (WTRU) and methods implemented therein are described. A method, implemented in a WTRU configured in multipath with mode 2 on sidelink and at least one flexible radio bearer configured with both a Uu logical channel and an SL logical channel, includes receiving a configuration for a dedicated Uu scheduling request (SR) related to a condition associated with mode 2 resource selection. The WTRU transmits the dedicated Uu SR based on the condition being met.

Abstract: Methods, apparatuses, and computer-readable storage media for facilitating condition mobility may perform conditional path switching. In various embodiments, handover of a WTRU from a current cell to a target cell may involve an intermediate relay WTRU, wherein the handover may occur upon specific conditions being met. For example, a remote WTRU may receive path switching configuration information associated with each of a plurality of candidate relay WTRUs. The remote WTRU may select a relay WTRU from the plurality of candidate relay WTRUs based on conditions being satisfied. The path switching configuration information associated with the selected relay WTRU may be applied to the remote WTRU. The remote WTRU may send a message to a network regarding the plurality of candidate relay WTRUs, and may receive an indication to connect to another relay WTRU.

Abstract: A WTRU may be configured to receive a bearer configuration information. For example, the bearer configuration information may comprise at least one of: a configuration for a first bearer that is associated with a direct path, a configuration for a second bearer that is associated with an indirect path, and/or a configuration for a third bearer that is associated with the direct path and the indirect path. The WTRU may receive data at the third bearer. The WTRU may determine a BSR type associated with the received data based at least on a primary path configured for the WTRU. For example, if the primary path configured for the WTRU is the direct path, BSR type may be determined to be the Uu BSR. If, for example, the primary path configured for the WTRU is the indirect path, the BSR type may be determined to be a SL BSR.

Abstract: Methods, apparatuses, and computer-readable storage media for implementing condition mobility may facilitate conditional path switching. In various embodiments, handover of a WTRU from a current cell to a target cell may involve a relay WTRU, wherein the handover may occur upon specific conditions being met. For example, a remote WTRU may receive conditional path switching configuration information associated with a target relay WTRU. The information may comprise a triggering condition and sidelink (SL) reconfiguration information associated with each of a plurality of candidate relay WTRUs. Upon a determination that the triggering condition has been satisfied, the remote WTRU may apply the conditional path switching configuration information associated with the target relay WTRU.