Channel access priority for sidelinks

Abstract

Aspects of the present disclosure relate to methods, apparatuses, and systems for supporting channel access priority for a sidelink. For example, an implementation provides for efficient channel access priority level (CAPC) processing for sidelink transmissions that takes into account delay attributes (e.g., packet delay budget (PDB) parameters) of logical channels multiplexed in transport blocks on cells configured with shared spectrum. In an implementation, a UE selects a highest priority CAPC for one or more sidelink logical channels having media access control (MAC) service data units (SDUs) multiplexed in a transport block.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. patent application serial number 63 / 391,921, filed on July 25, 2022, entitled “CHANNEL ACCESS PRIORITY FORSIDELINK,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to wireless communications, and more particularly to sidelink communications. Background Art

[0004] A wireless communication system may include one or more network communication devices (such as base stations), which may be referred to as eNodeB (eNB), next generation NodeB (gNB) or other suitable terms. Each network communication device (such as a base station) may support wireless communication of one or more user communication devices, which may also be referred to as user equipment (UE) or other suitable terms. A wireless communication system may support wireless communication with one or more user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, time slots, subframes, frames, etc.) or frequency resources (e.g., subcarriers, carriers)). In addition, a wireless communication system may support wireless communication across various radio access technologies, including third generation (3G) radio access technology, fourth generation (4G) radio access technology, fifth generation (5G) radio access technology, and other suitable radio access technologies beyond 5G (e.g., sixth generation (6G)).

[0005] Some wireless communication systems provide methods for enabling sidelink transmissions between devices, such as for direct transmissions between different UEs. The sidelink transmissions may occur in an unlicensed spectrum that may be shared between multiple devices, and thus a listen-before-talk process may be performed to identify an available channel for the sidelink transmission. Summary of the invention

[0006] The present disclosure relates to methods, devices and systems for supporting channel access priority for sidelinks. For example, an implementation provides efficient channel access priority level (CAPC) processing for sidelink transmissions that takes into account the delay properties (e.g., packet delay budget (PDB) parameters) of logical channels multiplexed in a transport block on a cell configured with a shared spectrum. In an implementation, a UE selects the highest priority CAPC of one or more sidelink logical channels (e.g., sidelink traffic channel (STCH)) with a media access control (MAC) service data unit (SDU) multiplexed in a transport block to enable the PDB of the transport block to be satisfied.

[0007] By utilizing the described techniques, transmission delays for high priority data may be reduced, and transmission reliability of such data may be improved.

[0008] Some implementations of the methods and apparatus described herein may also include generating a transport block comprising one or more MAC SDUs for one or more sidelink logical channels for sidelink transmission; performing a listen-before-talk procedure based at least in part on one or more listen-before-talk parameters of a CAPC priority, wherein the CAPC priority corresponds to a highest priority CAPC for one or more sidelink logical channels having one or more MAC SDUs in the transport block; and sending the transport block based at least in part on the success of the listen-before-talk procedure.

[0009] Some implementations of the methods and apparatus described herein may further include: determining a CAPC priority based at least in part on a delay parameter of one or more sidelink logical channels; wherein the delay parameter includes a PDB of a transport block; further including selecting a sidelink grant for sending the transport block, and wherein sending the transport block may include sending the transport block using the sidelink grant; further including performing a sensing process to select the sidelink grant; wherein the method is performed by a user equipment (UE), and wherein the method further includes autonomously selecting a CAPC priority by the UE; wherein the method is performed by a user equipment (UE), and wherein the method further includes determining the CAPC priority based at least in part on information received from a network entity.

[0010] Some implementations of the methods and apparatus described herein may also include: generating a transport block to include one or more MAC control elements (CEs); and selecting a CAPC priority as a highest priority CAPC for one or more MAC CEs; also including: generating a transport block to include one or more sidelink broadcast control channel (SBCCH) SDUs; and selecting a CAPC priority as a highest priority CAPC for one or more SBCCH SDUs; also including: generating a transport block to include one or more sidelink control channel (SCCH) SDUs; and selecting a CAPC priority as a highest priority CAPC for one or more SCCH SDUs; and also including selecting a CAPC priority based at least in part on priority information received as part of sidelink control information (SCI).

[0011] Some implementations of the methods and apparatus described herein may also include performing a channel access procedure to obtain a channel occupancy time (COT) associated with a first CAPC priority for a listen-before-talk procedure; receiving downlink control information (DCI) that specifies a sidelink grant for the listen-before-talk procedure and a second CAPC priority for the sidelink grant; and determining whether to send a sidelink transmission using the COT based on a comparison of the first CAPC priority and the second CAPC priority.

[0012] Some implementations of the methods and apparatus described herein may also include determining that a first CAPC priority is equal to or higher than a second CAPC priority; and sending a sidelink transmission using a COT based at least in part on the first CAPC priority being equal to or higher than the second CAPC priority; and also include determining that the first CAPC priority is lower than the second CAPC priority; terminating the COT; and initiating transmission of the sidelink transmission using a sidelink grant and based at least in part on the second CAPC priority.

[0013] Some implementations of the methods and apparatus described herein may also include generating a transport block comprising one or more MAC service data units (SDUs) of one or more sidelink logical channels for sidelink transmission, and processing the transport block based on a comparison of a CAPC priority of the transport block for a listen-before-talk procedure with a PDB of the transport block.

[0014] Some implementations of the methods and apparatus described herein may further include: wherein processing a transmission block includes: determining that a contention window for a listen-before-talk process is greater than a PDB of the transmission block, wherein the contention window is determined based on a CAPC priority; and determining not to send the transmission block based at least in part on the contention window for the listen-before-talk process being greater than the PDB of the transmission block; wherein determining that the contention window based on the CAPC priority of the listen-before-talk process is greater than the PDB of the transmission block is based on one or more of the following: initialization of a channel access process for accessing one or more sidelink logical channels; or after initialization of the channel access process; discarding the transmission block from a transmission buffer.

[0015] Some implementations of the methods and apparatus described herein may also include: wherein processing a transmission block includes: determining that a contention window for a listen-before-talk process is greater than a PDB of the transmission block, wherein the contention window is determined based on a CAPC priority; adjusting the CAPC priority; determining that a contention window based on the adjusted CAPC priority is less than the PDB of the transmission block; and sending the transmission block based at least in part on the adjusted CAPC priority; wherein processing the transmission block includes: determining that a contention window for a listen-before-talk process is greater than the PDB of the transmission block, wherein the contention window is determined based on the CAPC priority; adjusting the CAPC priority; determining that a contention window determined based on the adjusted CAPC priority is greater than the PDB of the transmission block; and determining not to send the transmission block based at least in part on the adjusted CAPC priority. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 An example of a wireless communication system supporting channel access priority for a sidelink according to aspects of the present disclosure is illustrated.

[0017] Figure 2Scenario 200 is illustrated, depicting example attributes of channel access used in some wireless communication systems.

[0018] Figure 3 An example MAC PDU is illustrated.

[0019] Figure 4 An example of a block diagram of a device supporting channel access priority for a sidelink according to aspects of the present disclosure is illustrated.

[0020] Figures 5 to 15 A flow chart of a method of supporting channel access priority for a sidelink according to aspects of the present disclosure is illustrated. DETAILED DESCRIPTION

[0021] In some wireless communication systems, a CAPC value is autonomously selected by the UE for a configuration grant (CG) physical uplink shared channel (PUSCH) transmission. For example, in a scenario where a transport block (TB) does not contain a MAC CE or a signal radio bearer (SRB), the UE selects the lowest priority CAPC in the LCH with the MAC SDU multiplexed in the TB. Applying the same behavior to a sidelink transmission where the sending UE selects a CAPC value may result in the UE selecting a CAPC that is inconsistent with the data included in the transport block. For example, when a TB contains low priority data, the UE may select a high CAPC index (e.g., a low priority CAPC) even if the sidelink resource is selected based on the PDB of the TB, which is determined based on the logical channel with the most stringent PDB requirements. Therefore, there may be a mismatch between the CAPC value selected for the TB and the PDB of the TB. For example, in some wireless communication systems, a listen-before-talk process including a contention window determined based on the CAPC may not be able to achieve conditions that allow transmission before the PDB of the TB expires, for example, the specified minimum channel access sensing duration may be too large to accommodate the PDB.

[0022] Thus, the present disclosure relates to methods, apparatus, and systems for supporting channel access priority for a sidelink. For example, an implementation provides efficient CAPC processing for sidelink transmissions that takes into account the latency properties (e.g., PDB parameters) of logical channels multiplexed in a transport block on a cell configured with a shared spectrum. In an implementation, a UE selects the highest priority CAPC for one or more sidelink logical channels (e.g., STCH) with a MAC SDU multiplexed in a transport block to enable the PDB of the transport block to be satisfied.

[0023] In at least some implementations, when performing CAT4 listen-before-talk (e.g., type 1 listen-before-talk) for sidelink TB transmissions with predefined rules, the UE autonomously determines the CAPC to use. For example, when performing listen-before-talk for sidelink TB transmissions, the UE selects the CAPC as the highest priority CAPC for the sidelink logical channel(s) with MAC SDUs multiplexed in the TB, such as, for example, in a scenario where the TB does not contain a sidelink SRB or MAC CE.

[0024] Except for at least some implementations, for scenarios where the CAPC value associated with a TB does not satisfy the PDB of the TB, the UE may skip sidelink TB transmissions. For example, a listen-before-talk process including a contention window determined as a function of the CAPC may not allow transmission of a transport block before the PDB of the transport block expires. In at least some implementations, in scenarios where TB transmissions are skipped due to not satisfying the PDB requirement, the UE may discard the TB from the transmission buffer.

[0025] Therefore, by utilizing the described techniques, transmission delays for high priority data may be reduced, and transmission reliability of such data may be improved.

[0026] Aspects of the present disclosure are described in the context of a wireless communication system. Aspects of the present disclosure are further illustrated and described with reference to device diagrams and flow charts.

[0027] Figure 1 An example of a wireless communication system 100 supporting channel access priority for a side link according to various aspects of the present disclosure is illustrated. The wireless communication system 100 may include one or more network entities 102, one or more UEs 104, a core network 106, and a packet data network 108. The wireless communication system 100 may support various radio access technologies. In some implementations, the wireless communication system 100 may be a 4G network, such as an LTE network or an advanced LTE (LTE-A) network. In some other implementations, the wireless communication system 100 may be a 5G network, such as an NR network. In other implementations, the wireless communication system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technologies, including the Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20. The wireless communication system 100 may support radio access technologies other than 5G. In addition, the wireless communication system 100 may support technologies such as time division multiple access (TDMA), frequency division multiple access (FDMA), or code division multiple access (CDMA).

[0028] One or more network entities 102 may be dispersed throughout a geographic area to form a wireless communication system 100. One or more of the network entities 102 described herein may be or include or may be referred to as a network node, a base station, a network element, a RAN, a base transceiver station, an access point, a NodeB, an eNodeB (eNB), a next generation NodeB (gNB), or other suitable terms. The network entity 102 and the UE 104 may communicate via a communication link 110, which may be a wireless or wired connection. For example, the network entity 102 and the UE 104 may perform wireless communication (e.g., receive signaling, send signaling) over a Uu interface.

[0029] The network entity 102 may provide a geographic coverage area 112 for which the network entity 102 may support services (e.g., voice, video, packet data, messaging, broadcast, etc.) for one or more UEs 104 within the geographic coverage area 112. For example, the network entity 102 and the UE 104 may support wireless communications of signals associated with services (e.g., voice, video, packet data, messaging, broadcast, etc.) according to one or more radio access technologies. In some implementations, the network entity 102 may be mobile, for example, a satellite associated with a non-terrestrial network. In some implementations, different geographic coverage areas 112 associated with the same or different radio access technologies may overlap, but different geographic coverage areas 112 may be associated with different network entities 102. The information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0030] One or more UEs 104 may be dispersed throughout the geographic area of ​​the wireless communication system 100. UE 104 may include or may be referred to as a mobile device, a wireless device, a remote device, a remote unit, a handheld device, a subscriber device, or some other suitable term. In some implementations, UE 104 may be referred to as a unit, a station, a terminal, or a client, as well as other examples. Additionally or alternatively, UE 104 may be referred to as an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communication (MTC) device, as well as other examples. In some implementations, UE 104 may be stationary in the wireless communication system 100. In some other implementations, UE 104 may be mobile in the wireless communication system 100.

[0031] One or more UEs 104 may be devices of different forms or with different capabilities. Figure 1 Some examples of UE 104 are illustrated in FIG. Figure 1 As shown, UE 104 may be able to communicate with various types of devices, such as network entity 102, other UEs 104, or network devices (e.g., core network 106, packet data network 108, relay device, integrated access and backhaul (IAB) node, or another network device), such as Figure 1 Additionally or alternatively, the UE 104 can support communications with other network entities 102 or UEs 104 that can act as relays in the wireless communication system 100.

[0032] The UE 104 may also be capable of supporting wireless communications directly with other UEs 104 via a communication link 114. For example, the UE 104 may support wireless communications directly with another UE 104 via a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, V2X deployments, or cellular V2X deployments, the communication link 114 may be referred to as a side link. For example, the UE 104 may support wireless communications directly with another UE 104 via a PC5 interface.

[0033] The network entity 102 may support communication with the core network 106 or with another network entity 102 or both. For example, the network entity 102 may interface with the core network 106 via one or more backhaul links 116 (e.g., via S1, N2, N2 or another network interface). The network entities 102 may communicate with each other via the backhaul links 116 (e.g., via X2, Xn or another network interface). In some implementations, the network entities 102 may communicate directly with each other (e.g., between the network entities 102). In some other implementations, the network entities 102 may communicate with each other or indirectly (e.g., via the core network 106). In some implementations, one or more network entities 102 may include subcomponents, such as an access network entity, which may be an example of an access node controller (ANC). The ANC may communicate with one or more UEs 104 via one or more other access network transport entities (which may be referred to as radio heads, smart radio heads, or transport reception points (TRPs)).

[0034] In some implementations, the network entity 102 may be configured in a decomposed architecture that may be configured to utilize a protocol stack that is physically or logically distributed between two or more network entities 102, such as an integrated access backhaul (IAB) network, an open RAN (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance), or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN)). For example, the network entity 102 may include one or more of a central unit (CU), a distributed unit (DU), a radio unit (RU), a RAN intelligent controller (RIC) (e.g., a near real-time RIC (near real-time (RT) RIC), a non-real-time RIC (non-RT RIC)), a service management and orchestration (SMO) system, or any combination thereof.

[0035] The RU may also be referred to as a radio head, a smart radio head, a remote radio head (RRH), a remote radio unit (RRU), or a transmission reception point (TRP). In a decomposed RAN architecture, one or more components of the network entity 102 may be collocated, or one or more components of the network entity 102 may be located at distributed locations (e.g., separate physical locations). In some implementations, one or more network entities 102 of the decomposed RAN architecture may be implemented as virtual units (e.g., virtual CU (VCU), virtual DU (VDU), virtual RU (VRU)).

[0036] The functional split between CU, DU and RU can be flexible, and different functions can be supported according to the functions performed at the CU, DU or RU (e.g., network layer functions, protocol layer functions, baseband functions, radio frequency functions and any combination thereof). For example, a functional split of a protocol stack can be adopted between a CU and a DU so that the CU can support one or more layers of the protocol stack and the DU can support one or more different layers of the protocol stack. In some implementations, the CU can host upper protocol layer (e.g., Layer 3 (L3), Layer 2 (L2)) functions and signaling (e.g., Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), Packet Data Convergence Protocol (PDCP)). The CU can be connected to one or more DUs or RUs, and one or more DUs or RUs can host lower protocol layers, such as Layer 1 (L1) (e.g., physical (PHY) layer) or L2 (e.g., radio link control (RLC) layer, MAC layer) functions and signaling, and each can be at least partially controlled by the CU.

[0037] Additionally or alternatively, a functional split of the protocol stack may be employed between the DU and the RU such that the DU may support one or more layers of the protocol stack and the RU may support one or more different layers of the protocol stack. The DU may support one or more different cells (e.g., via one or more RUs). In some implementations, the functional split between the CU and the DU or between the DU and the RU may be within the protocol layer (e.g., some functions of the protocol layer may be performed by one of the CU, DU, or RU, while other functions of the protocol layer may be performed by different ones of the CU, DU, or RU).

[0038] The CU may be further functionally split into CU control plane (CU-CP) and CU user plane (CU-UP) functions. The CU may be connected to one or more DUs via a medium-range communication link (e.g., F1, F1-c, F1-u), and the DU may be connected to one or more RUs via a fronthaul communication link (e.g., an open fronthaul (FH) interface). In some implementations, the medium-range communication link or the fronthaul communication link may be implemented based on interfaces (e.g., channels) between layers of a protocol stack supported by a corresponding network entity 102 communicating via such a communication link.

[0039] The core network 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The core network 106 may be an evolved packet core (EPC) or a 5G core (5GC), which may include control plane entities that manage access and mobility (e.g., mobility management entity (MME), access and mobility management function (AMF)), and user plane entities that route packets or interconnects to external networks (e.g., serving gateway (S-GW), packet data network (PDN) gateway (P-GW), or user plane function (UPF)). In some implementations, the control plane entities may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signal bearers, etc.) of one or more UEs 104 served by one or more network entities 102 associated with the core network 106.

[0040] The core network 106 may communicate with the packet data network 108 via one or more backhaul links 116 (e.g., via S1, N2, N2, or another network interface). The packet data network 108 may include an application server 118. In some implementations, one or more UEs 104 may communicate with the application server 118. The UE 104 may establish a session (e.g., a protocol data unit (PDU) session, etc.) with the core network 106 via the network entity 102. The core network 106 may use the established session (e.g., the established PDU session) to route traffic (e.g., control information, data, etc.) between the UE 104 and the application server 118. The PDU session may be an example of a logical connection between the UE 104 and the core network 106 (e.g., one or more network functions of the core network 106).

[0041] In the wireless communication system 100, the network entity 102 and the UE 104 may use the resources of the wireless communication system 100 (e.g., time resources (e.g., symbols, time slots, subframes, frames, etc.) or frequency resources (e.g., subcarriers, carriers)) to perform various operations (e.g., wireless communication). In some implementations, the network entity 102 and the UE 104 may support different resource structures. For example, the network entity 102 and the UE 104 may support different frame structures. In some implementations, such as in 4G, the network entity 102 and the UE 104 may support a single frame structure. In some other implementations, such as in 5G and other suitable radio access technologies, the network entity 102 and the UE 104 may support various frame structures (e.g., multiple frame structures). The network entity 102 and the UE 104 may support various frame structures based on one or more parameter sets (numerologies).

[0042] One or more parameter sets may be supported in the wireless communication system 100, and the parameter sets may include subcarrier spacing and cyclic prefixes. A first parameter set (e.g., μ=0) may be associated with a first subcarrier spacing (e.g., 15kHz) and a normal cyclic prefix. A first parameter set (e.g., μ=0) associated with a first subcarrier spacing (e.g., 15kHz) may utilize one slot per subframe. A second parameter set (e.g., μ=1) may be associated with a second subcarrier spacing (e.g., 30kHz) and a normal cyclic prefix. A third parameter set (e.g., μ=2) may be associated with a third subcarrier spacing (e.g., 60kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth parameter set (e.g., μ=3) may be associated with a fourth subcarrier spacing (e.g., 120kHz) and a normal cyclic prefix. A fifth parameter set (e.g., μ=4) may be associated with a fifth subcarrier spacing (e.g., 240kHz) and a normal cyclic prefix.

[0043] The time intervals of resources (e.g., communication resources) can be organized according to frames (also referred to as radio frames). Each frame can have a duration, for example, a duration of 10 milliseconds (ms). In some implementations, each frame can include multiple subframes. For example, each frame can include 10 subframes, and each subframe can have a duration, for example, a duration of 1 ms. In some implementations, each frame can have the same duration. In some implementations, each subframe of a frame can have the same duration.

[0044] Additionally or alternatively, the time intervals of resources (e.g., communication resources) can be organized according to time slots. For example, a subframe may include a certain number (e.g., quantity) of time slots. Each time slot may include a certain number (e.g., quantity) of symbols (e.g., orthogonal frequency division multiplexing (OFDM) symbols). In some implementations, the number (e.g., quantity) of time slots of a subframe may depend on a parameter set. For a normal cyclic prefix, a time slot may include 14 symbols. For an extended cyclic prefix (e.g., applicable to a 60kHz subcarrier spacing), a time slot may include 12 symbols. For a normal cyclic prefix and an extended cyclic prefix, the relationship between the number of symbols per time slot, the number of time slots per subframe, and the number of time slots per frame may depend on a parameter set. It should be understood that references to a first parameter set (e.g., μ=0) associated with a first subcarrier spacing (e.g., 15kHz) may be used interchangeably between subframes and time slots.

[0045] In the wireless communication system 100, the electromagnetic (EM) spectrum can be divided into various categories, frequency bands, frequency channels, etc. based on frequency or wavelength. For example, the wireless communication system 100 can support one or more operating frequency bands, such as frequency range names FR1 (410 MHz-7.125 GHz), FR2 (24.25 GHz-52.6 GHz), FR3 (7.125 GHz-24.25 GHz), FR4 (52.6 GHz-114.25 GHz), FR4a or FR4-1 (52.6 GHz-71 GHz), and FR5 (114.25 GHz-300 GHz). In some implementations, the network entity 102 and the UE 104 can perform wireless communications on the one or more operating frequency bands. In some implementations, FR1 can be used by the network entity 102 and the UE 104 and other devices or apparatuses for cellular communication services (e.g., control information, data). In some implementations, FR2 can be used by the network entity 102 and the UE 104 and other devices or apparatuses for short-range, high data rate capabilities.

[0046] FR1 may be associated with one or more parameter sets (e.g., at least three parameter sets). For example, FR1 may be associated with a first parameter set (e.g., μ=0) including a subcarrier spacing of 15 kHz; a second parameter set (e.g., μ=1) including a subcarrier spacing of 30 kHz; a third parameter set (e.g., μ=2) including a subcarrier spacing of 60 kHz. FR2 may be associated with one or more parameter sets (e.g., at least 2 parameter sets). For example, FR2 may be associated with a third parameter set (e.g., μ=2) including a subcarrier spacing of 60 kHz; a fourth parameter set (e.g., μ=3) including a subcarrier spacing of 120 kHz.

[0047] According to the implementation of channel access priority for the sidelink, UE 104a generates a transmission block 120 for transmission via the sidelink. For example, the transmission block 120 includes one or more MAC SDUs of one or more sidelink logical channels for the sidelink transmission. UE 104a then performs a listen-before-talk process 122 to determine whether one or more sidelink logical channels are available for sidelink transmission of the transmission block 120. In conjunction with the listen-before-talk process 122, UE 104a selects a CAPC 124 for performing the listen-before-talk process 122. For example, UE 104a performs the listen-before-talk process 122 based at least in part on one or more channel access parameters of a CAPC 124 priority, wherein the CAPC 124 priority corresponds to the highest priority CAPC among the one or more sidelink logical channels having the one or more MAC SDUs in the transmission block. Therefore, after successfully performing the listen-before-talk process 122, UE 104a sends the transmission block 120 to UE 104b as a sidelink transmission 126.

[0048] Figure 2 Scenario 200 is illustrated, which depicts example attributes of channel access used in some wireless communication systems. Scenario 200 includes a wireless channel 202 having a starting downlink portion subframe, an ending downlink portion subframe, and different downlink and uplink transmission portions. In addition, wireless channel 202 includes different listen-before-talk portions 204 and reserved signal portions 206. Channel access in both the downlink and uplink can rely on listen-before-talk. In at least some scenarios, the gNB and / or UE first senses the channel using a listen-before-talk procedure (e.g., clear channel assessment (CCA)) to determine whether there is ongoing communication on the channel before transmitting. For example, when wireless channel 202 is a wideband unlicensed carrier, the listen-before-talk procedure can rely on detecting energy levels on multiple subbands of wireless channel 202.

[0049] In scenarios where consistent listen-before-talk failures occur, the UE may autonomously switch uplink (UL) bandwidth parts (BWPs) in some scenarios. This is to allow other UL BWPs of the NR-U cell to mitigate a large number of listen-before-talk failures, e.g., different listen-before-talk subbands are used by different UL BWPs.

[0050] For LTE eLAA, autonomous uplink (AUL) transmissions can be enabled through a combination of RRC signaling and an activation message conveyed by DCI in the physical control channel. The RRC configuration includes the subframes in which the UE is allowed to transmit autonomously, and the eligible hybrid automatic repeat request (HARQ) process IDs. The activation message includes the resource block assignment (RBA) and the modulation and coding scheme (MCS), from which the UE can determine the transport block size for any AUL transmission.

[0051] Some scenarios allow autonomous retransmission of data related to a transport block that was not correctly received by a base station (e.g., eNB, gNB, etc.). For this purpose, the UE may monitor downlink feedback information (AUL-DFI), which may be sent by the base station and include HARQ acknowledgement (ACK) information for the AUL-enabled HARQ process ID. When the UE detects a negative acknowledgement (NACK) message, it may attempt to autonomously access the channel for retransmission of the same transport block in the corresponding HARQ process. To reduce errors, the autonomous uplink transmission may include at least a HARQ process identifier (ID) and a new data indicator (NDI) accompanying the PUSCH, such as AUL uplink control information (UCI).

[0052] Some scenarios also allow the base station to send an uplink grant via DCI that allocates uplink resources for retransmissions of the same transport block using the indicated HARQ process. The base station may also send an uplink grant via DCI that allocates uplink resources for transmission of a new transport block using the indicated HARQ process. For example, even if the HARQ process ID is eligible for AUL transmission, the base station may still access the process at any time via a scheduling grant (e.g., DCI). Typically, if a UE detects a grant for UL transmission for a subframe that is eligible for AUL (e.g., based on an RRC configuration), the UE may follow the received grant and may not perform AUL transmission in that subframe.

[0053] Table 1: Fields used for AUL-UCI

[0054]

[0055]

[0056] The listen-before-talk procedure used by some wireless communication systems for channel access includes the following:

[0057] - Both base station initiated COT and UE initiated COT use Category 4 listen before talk, where the initiation of a new transmission burst includes listen before talk with exponential backoff. In addition, in some scenarios, the duration of the dedicated reference signal (DRS) is at most 1 ms, and the DRS is not multiplexed with the unicast physical downlink shared channel (PDSCH).

[0058] - UL transmissions within a COT initiated by the base station and / or subsequent downlink transmissions within a COT initiated by the UE or the base station can be sent immediately without sensing only if the gap to the end of the previous transmission does not exceed 16 μs, otherwise Category 2 listen-before-talk is used,

[0059] And the gap does not exceed 25μs.

[0060] In some scenarios, when a UE and / or base station in an unlicensed carrier is to perform operations within Category 4 Listen-Before-Talk as specified by regulations, several CAPCs may be defined with different channel access parameters, such as described in Tables 2 and 3 of Technical Specification (TS) 37.213.

[0061] Table 2: CAPC for downlink

[0062]

[0063] Table 3: CAPC for uplink

[0064]

[0065] Figure 3 An example MAC PDU 300 is illustrated. For example, for dynamically scheduled uplink resources (e.g., UL DCI), the base station can indicate the CAPC to be used by the UE for the corresponding uplink transmission. For uplink configuration grants, the network does not signal the CAPC index at each opportunity, and thus the UE itself can select which CAPC to use at each opportunity. According to some scenarios, the UE selects the lowest priority CAPC for the LCH multiplexed in the TB. For example, for MAC PDU 300, the UE can select CAPC 4, e.g., the lowest priority.

[0066] According to the above behavior, a small amount of data may belong to the highest CAPC index, as described above, but the UE still applies a low priority CAPC index to the high priority data, which may cause a certain delay in transmission. Therefore, in some scenarios of UL CG, if an SRB (e.g., dedicated control channel (DCCH)) SDU is included in the MAC PDU, the UE may select the CAPC index of the SRB (DCCH). Otherwise, the UE selects the lowest priority CAPC index of the LCH multiplexed in the MAC PDU. Example rules for CAPC settings are further outlined below.

[0067] The CAPC for radio bearers and MAC CE can be fixed or configurable:

[0068] Fixed for filling buffer status report (BSR) and recommended bit rate MAC CE

[0069] is the lowest priority;

[0070] For SRB0, SRB1, SRB3 and other MAC CEs, they are fixed as the highest priority;

[0071] Configured by the gNB for SRB2 and Data Radio Bearers (DRBs).

[0072] When selecting the CAPC for a DRB, the base station may consider the 5QIs of all QoS flows multiplexed in the DRB, while taking into account fairness between different service types and transmissions. Table 4 below shows which CAPC can be used for which standardized 5QI, for example, which CAPC is used for a given QoS flow. In some scenarios, a QoS flow corresponding to a non-standardized 5QI (e.g., an operator-specific 5QI) will use a CAPC for a standardized 5QI that best matches the QoS characteristics of the non-standardized 5KI.

[0073]

[0074] In some scenarios, when CAT4 listen-before-talk (e.g., type 1 listen-before-talk) is performed for uplink TB transmission (see TS 37.213 clause 4.2.1.1), and when CAPC is not indicated in the DCI, the UE may select the CAPC as follows:

[0075] If only MAC CE(s) are included in the TB, the highest priority CAPC of these MAC CE(s) is used; or

[0076] If the TB includes (multiple) DCCH SDUs, the highest priority CAPC is used; or

[0077] If the TB includes DCCH SDU(s), then the highest priority CAPC of the DCCH(s) is used; or

[0078] • Otherwise, the lowest priority CAPC of the logical channel(s) with MAC SDUs multiplexed in the TB is used.

[0079] Therefore, in some wireless communication systems, there may be a mismatch between the CAPC value determined for a TB and the PDB of the TB.

[0080] Therefore, solutions are provided in the present disclosure to allow efficient CAPC processing for sidelink transmissions on cells configured with shared spectrum. For example, in at least some implementations, the UE can autonomously determine the CAPC to use when performing CAT4 listen-before-talk (e.g., type 1 listen-before-talk) for sidelink TB transmissions based on some predefined rules.

[0081] In at least one example implementation, such a rule may be one and / or a combination of the following, where the combination may be a logical OR combination: When performing listen-before-talk for sidelink TB transmission, the UE selects a CAPC as follows:

[0082] If the sidelink TB only includes (multiple) sidelink MAC CEs, this

[0083] The highest priority CAPC of some (multiple) sidelink MAC CEs;

[0084] If the sidelink TB only includes (multiple) sidelink MAC CEs, the most

[0085] High priority CAPC;

[0086] If the TB contains (multiple) SBCCH SDUs, the highest priority CAPC is used;

[0087] If the TB contains (multiple) SCCH SDUs, the highest priority CAPC is used;

[0088] If the TB includes (multiple) SCCH SDUs, the highest priority CAPC of (multiple) SCCHs is used;

[0089] • Otherwise, the highest priority CAPC of the sidelink logical channel(s) (eg, STCH) with MAC SDUs multiplexed in the TB is used.

[0090] Note that SBCCH is a channel used to broadcast sidelink system information from a UE to (multiple) other UEs. SCCH is a channel used for transmission of control information (i.e., PC5-RRC and PC5-S messages) from a UE to (multiple) other UEs. STCH refers to a logical channel used for transmission of user data from a UE to (multiple) other UEs.

[0091] According to one or more implementations, a mapping is provided between a CAPC value used for transmission of a sidelink TB and a priority value signaled within the SCI. For example, a table is provided that specifies a relationship between a priority value signaled in the SCI for a TB and a CAPC value to be used when performing CAT4 listen-before-talk (Type 1 listen-before-talk) for transmission of a sidelink TB.

[0092] According to one or more implementations, the UE may select a CAPC value such that the PDB of the TB is satisfied. For example, in a scenario where the PDB of the TB is below a configured threshold, the UE selects the highest priority CAPC (e.g., value = 1). For certain ranges of PDB values, corresponding CAPC values ​​to be used when performing listen-before-talk on the TB are defined. For example, for a scenario where the PDB of the TB is above a pre-configured threshold, the UE may select a CAPC value defined by the above rules, e.g., the PDB does not affect the CAPC selection because a large PDB can tolerate any CAPC priority.

[0093] According to one or more implementations, if a UE receives a DCI indicating a sidelink grant for scheduling a physical sidelink shared channel (PSSCH) transmission using a type 1 channel access procedure, and if the UE has an ongoing type 1 channel access procedure prior to the PSSCH transmission start time, e.g., the UE has acquired a COT with a CAPC value (e.g., the UE is operating in sidelink mode 2):

[0094] ·If the sidelink channel access priority level value p1 for an ongoing type 1 channel access procedure (e.g., a UE operating in sidelink mode 2) is equal to or greater than the sidelink channel access priority level value p2 indicated in the DCI, the UE may send a sidelink transmission (e.g., one or more of PSCCH, PSSCH, physical sidelink feedback channel (PSFCH), reference signal, etc.) in response to a sidelink grant by accessing the channel using the ongoing type 1 channel access procedure.

[0095] If the sidelink channel access priority level value p1 for an ongoing type 1 channel access procedure is less than the sidelink channel access priority level value p2 indicated in the DCI, the UE shall terminate the ongoing channel access procedure. Alternatively, the UE may ignore the received DCI and continue COT, e.g., sidelink mode 2 transmission.

[0096] According to one or more implementations, for scenarios where the CAPC value associated with a TB does not satisfy the PDB requirement for the TB, the UE may skip TB transmission. For example, a listen-before-talk process including a contention window determined based on the CAPC (e.g., as described above) may not be able to achieve conditions that allow transmission before the PDB expires. This may be known in an initialization step of the channel access process if the required minimum total channel access sensing duration exceeds the PDB for the TB, or at any time during an ongoing channel access process if the remaining required minimum channel access sensing duration exceeds the PDB for the TB. In at least one implementation, in a scenario where TB transmission is skipped due to non-satisfaction of the PDB requirement, the UE discards the TB from a transmission buffer (e.g., a HARQ transmission buffer).

[0097] According to one or more implementations, in a scenario where the selected CAPC value associated with a TB does not satisfy the PDB requirement of the TB, the UE increases the channel access priority level priority of the transmission attempt of the sidelink TB (e.g., selects a lower channel access priority level value). For example, the UE decreases the CAPC value selected for the TB by one index value and checks whether the PDB is satisfied. The check whether the PDB is satisfied can be determined as a check of the minimum allowed contention window size for the assumed CAPC value, or alternatively, as a check after an initialization step of the channel access procedure, such as where a determination is made between 0 and CW. p A random number between .

[0098] In the scenario where the PDB still cannot be met, the UE may further reduce the CAPC value. These steps may be repeated until the PDB is met or the minimum CAPC value is reached. If the PDB still cannot meet the minimum defined CAPC value, such as the highest priority CAPC, the UE may skip the transmission attempt as described above.

[0099] Figure 4 An example of a block diagram 400 of a device 402 (e.g., an apparatus) supporting channel access priority for a sidelink in accordance with aspects of the present disclosure is illustrated. The device 402 may be an example of a UE 104 as described herein. The device 402 may support wireless communications with one or more network entities 102, UEs 104, or any combination thereof. The device 402 may include components for bidirectional communications, including components for sending and receiving communications (such as a processor 404, a memory 406, a transceiver 408, and an I / O controller 410). These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., a bus).

[0100] The processor 404, memory 406, transceiver 408, or various combinations thereof, or various components thereof may be examples of means for performing various aspects of the present disclosure described herein. For example, the processor 404, memory 406, transceiver 408, or various combinations or components thereof may support methods for performing one or more of the operations described herein.

[0101] In some implementations, the processor 404, memory 406, transceiver 408, or various combinations or components thereof may be implemented in hardware (e.g., in a communication management circuit system). The hardware may include a processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, which is configured to or otherwise supports components for performing the functions described in the present disclosure. In some implementations, the processor 404 and the memory 406 coupled to the processor 404 may be configured to perform one or more functions described herein (e.g., by executing instructions stored in the memory 406 by the processor 404). For example, in the context of the UE 104, the transceiver 408 and the processor 404 coupled to the transceiver 408 are configured to cause the UE 104 to perform various described operations and / or combinations thereof.

[0102] For example, according to examples disclosed herein, the processor 404 and / or the transceiver 408 can support wireless communication at the device 402. For example, the processor 404 and / or the transceiver 408 can be configured to and / or otherwise support a component for: generating a transport block including one or more MAC service data units (SDUs) of one or more sidelink logical channels for sidelink transmission; performing a listen-before-talk procedure based at least in part on one or more channel access parameters of a CAPC priority, wherein the CAPC priority corresponds to a highest priority CAPC of the one or more sidelink logical channels having one or more MAC SDUs in the transport block; and sending the transport block based at least in part on the success of the listen-before-talk procedure.

[0103] In addition, in some implementations, the processor 404 and / or the transceiver 408 may be configured to and / or otherwise support a component for: determining a CAPC priority based at least in part on a delay parameter of one or more sidelink logical channels; wherein the delay parameter includes a PDB of a transport block; selecting a sidelink grant for sending the transport block, and wherein sending the transport block includes sending the transport block using the sidelink grant; performing a sensing process to select the sidelink grant; wherein the apparatus includes a user equipment (UE) and autonomously selects the CAPC priority; wherein the apparatus includes a user equipment (UE) and determines a CAPC priority value based at least in part on information received from a network entity; generating a transport block to include one or more MAC CEs; and selecting the CAPC priority as a highest priority CAPC of the one or more MAC CEs; generating a transport block to include one or more SBCCH SDUs; and selecting the CAPC priority as a highest priority CAPC of the one or more SBCCH SDUs; generating a transport block to include one or more SCCH SDUs; and selecting the CAPC priority as a highest priority CAPC of the one or more SCCH SDUs; selecting the CAPC priority based at least in part on priority information received as part of the SCI.

[0104] In another example, according to examples disclosed herein, the processor 404 and / or the transceiver 408 can support wireless communications at the device 402. For example, the processor 404 and / or the transceiver 408 can be configured to or otherwise support a component for: performing a channel access procedure to acquire a COT associated with a first CAPC priority for a listen-before-talk procedure; receiving a DCI that specifies a sidelink grant for the listen-before-talk procedure and a second CAPC priority for the sidelink grant; and determining whether to send a sidelink transmission using the COT based on a comparison of the first CAPC priority and the second CAPC priority.

[0105] Additionally, in some implementations, the processor and transceiver are configured to cause the apparatus to: determine that the first CAPC priority is equal to or higher than the second CAPC priority; and based at least in part on the first CAPC priority being equal to or higher than the second CAPC priority, send a sidelink transmission using the COT; determine that the first CAPC priority is lower than the second CAPC priority; terminate the COT; and initiate transmission of the sidelink transmission using a sidelink grant and based at least in part on the second CAPC priority.

[0106] In another example, according to examples disclosed herein, the processor 404 and / or the transceiver 408 can support wireless communications at the device 402. For example, the processor 404 and / or the transceiver 408 can be configured to or otherwise support a component for: generating a transport block including one or more MAC SDUs for one or more sidelink logical channels for sidelink transmission; and processing the transport block based on a comparison of a CAPC priority of the transport block for a listen-before-talk procedure with a PDB of the transport block.

[0107] In addition, in some implementations, the processor and the transceiver are configured to cause the device to: determine that a contention window for a listen-before-talk process is larger than a PDB of a transmission block, wherein the contention window is determined based on a CAPC priority; and determine not to send the transmission block based at least in part on the contention window for the listen-before-talk process being larger than the PDB of the transmission block; determine that the contention window based on the CAPC priority of the listen-before-talk process is larger than the PDB of the transmission block when one or more of the following are performed: initialization of a channel access process for accessing one or more sidelink logical channels; or after initialization of the channel access process; discard the transmission block from a transmission buffer.

[0108] In addition, in some implementations, to process a transmission block, determine that a contention window for a listen-before-talk process is larger than a PDB of the transmission block, wherein the contention window is determined based on a CAPC priority / value; adjust the CAPC priority; determine that a contention window determined based on the adjusted CAPC priority is smaller than the PDB of the transmission block; and send the transmission block based at least in part on the adjusted CAPC priority; wherein to process the transmission block, determine that a contention window for a listen-before-talk process is larger than the PDB of the transmission block, wherein the contention window is determined based on the CAPC priority; adjust the CAPC priority; determine that a contention window determined based on the adjusted CAPC priority is larger than the PDB of the transmission block; and determine not to send the transmission block based at least in part on the adjusted CAPC priority.

[0109] The processor 404 may include an intelligent hardware device (e.g., a general purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some implementations, the processor 404 may be configured to operate a memory array using a memory controller. In some other implementations, the memory controller may be integrated into the processor 404. The processor 404 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 406) to cause the device 402 to perform various functions of the present disclosure.

[0110] The memory 406 may include random access memory (RAM) and read-only memory (ROM). The memory 406 may store computer-readable computer executable code, which includes instructions that, when executed by the processor 404, cause the device 402 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as a system memory or another type of memory. In some implementations, the code may not be directly executable by the processor 404, but may cause the computer (e.g., when compiled and executed) to perform the functions described herein. In some implementations, the memory 406 may include a basic I / O system (BIOS), which may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0111] I / O controller 410 can manage input and output signals of device 402. I / O controller 410 can also manage peripheral devices that are not integrated into device 402. In some implementations, I / O controller 410 can represent a physical connection or port to an external peripheral device. In some implementations, I / O controller 410 can utilize an operating system, such as Or another known operating system. In some implementations, I / O controller 410 can be implemented as part of a processor such as processor M08. In some implementations, a user can interact with device 402 via I / O controller 410 or via hardware components controlled by I / O controller 410.

[0112] In some implementations, the device 402 may include a single antenna 412. However, in some other implementations, the device 402 may have more than one antenna 412 (e.g., multiple antennas), including multiple antenna panels or antenna arrays, which are capable of concurrently sending or receiving multiple wireless transmissions. The transceiver 408 can communicate bidirectionally via one or more antennas 412, wired or wireless links, as described herein. For example, the transceiver 408 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. The transceiver 408 may also include a modem for modulating packets, providing the modulated packets to one or more antennas 412 for transmission, and demodulating packets received from one or more antennas 412.

[0113] Figure 5 A flow chart of a method 500 for supporting channel access priority of a side link according to aspects of the present disclosure is illustrated. The operations of the method 500 may be implemented by the apparatus described herein or components thereof. For example, the operations of the method 500 may be implemented by reference to Figures 1 to 4The UE 104 described herein performs. In some implementations, the device may execute an instruction set to control functional elements of the device to perform the described functions. Additionally or alternatively, the device may use dedicated hardware to perform various aspects of the described functions.

[0114] At 502, the method may include generating a transport block including one or more MAC SDUs for one or more sidelink logical channels for sidelink transmission. The operations of 502 may be performed according to examples as described herein. In some implementations, aspects of the operations of 502 may be described with reference to Figure 1 The device is used to perform the above.

[0115] At 504, the method may include performing a listen-before-talk procedure based at least in part on one or more listen-before-talk parameters of a CAPC priority, wherein the CAPC priority corresponds to a highest priority CAPC of one or more sidelink logical channels having one or more MAC SDUs in a transport block. The operations of 504 may be performed according to examples as described herein. In some implementations, aspects of the operations of 504 may be performed by reference to Figure 1 The device is used to perform the above.

[0116] At 506, the method may include sending a transport block based at least in part on the success of the listen-before-talk process. The operations of 506 may be performed according to examples as described herein. In some implementations, aspects of the operations of 506 may be described with reference to Figure 1 The device is used to perform the above.

[0117] Figure 6 600 for supporting channel access priority for a side link according to aspects of the present disclosure. The operations of the method 600 may be implemented by the apparatus described herein or components thereof. For example, the operations of the method 600 may be implemented by reference to Figures 1 to 4 The UE 104 described herein performs. In some implementations, the device may execute an instruction set to control functional elements of the device to perform the described functions. Additionally or alternatively, the device may use dedicated hardware to perform various aspects of the described functions.

[0118] At 602, the method may include generating a transport block to include one or more MAC CEs. The operations of 602 may be performed according to examples as described herein. In some implementations, aspects of the operations of 602 may be described with reference to Figure 1 The device is used to perform the above.

[0119] At 604, the method may include selecting the CAPC priority as the highest priority CAPC of the one or more MAC CEs. The operations of 604 may be performed according to examples as described herein. In some implementations, aspects of the operations of 604 may be described by reference to Figure 1 The device is used to perform the above.

[0120] Figure 7 1 is a flow chart of a method 700 for supporting channel access priority of a side link according to aspects of the present disclosure. The operations of the method 700 may be implemented by a device or component thereof as described herein. For example, the operations of the method 700 may be implemented by reference to Figures 1 to 4 The UE 104 described herein performs. In some implementations, the device may execute an instruction set to control functional elements of the device to perform the described functions. Additionally or alternatively, the device may use dedicated hardware to perform various aspects of the described functions.

[0121] At 702, the method may include generating a transport block to include one or more SBCCH SDUs. The operations of 702 may be performed according to examples as described herein. In some implementations, aspects of the operations of 702 may be described with reference to Figure 1 The device is used to perform the above.

[0122] At 704, the method may include selecting a CAPC priority as a highest priority CAPC for one or more SBCCH SDUs. The operations of 704 may be performed according to examples as described herein. In some implementations, aspects of the operations of 704 may be described by reference to Figure 1 The device is used to perform the above.

[0123] Figure 8 800 for supporting channel access priority for a side link according to aspects of the present disclosure. The operations of the method 800 may be implemented by the apparatus described herein or components thereof. For example, the operations of the method 800 may be implemented by reference to Figures 1 to 4 The UE 104 described herein performs. In some implementations, the device may execute an instruction set to control functional elements of the device to perform the described functions. Additionally or alternatively, the device may use dedicated hardware to perform various aspects of the described functions.

[0124] At 802, the method may include generating a transport block to include one or more SCCH SDUs. The operations of 802 may be performed according to examples as described herein. In some implementations, aspects of the operations of 802 may be described by reference to Figure 1 The device is used to perform the above.

[0125] At 804, the method may include selecting a CAPC priority as a highest priority CAPC for one or more SCCH SDUs. The operations of 804 may be performed according to examples as described herein. In some implementations, aspects of the operations of 804 may be described by reference to Figure 1 The device is used to perform the above.

[0126] Fig. 9 1 is a flow chart of a method 900 for supporting channel access priority of a side link according to aspects of the present disclosure. The operations of the method 900 may be implemented by a device or component thereof as described herein. For example, the operations of the method 900 may be implemented by reference to Figures 1 to 4 The UE 104 described herein performs. In some implementations, the device may execute an instruction set to control functional elements of the device to perform the described functions. Additionally or alternatively, the device may use dedicated hardware to perform various aspects of the described functions.

[0127] At 902, the method may include performing a channel access procedure to obtain a COT associated with a first CAPC priority of a listen-before-talk procedure. The operations of 902 may be performed according to examples as described herein. In some implementations, aspects of the operations of 902 may be described by reference to Figure 1 The device is used to perform the above.

[0128] At 904, the method may include receiving a DCI that specifies a sidelink grant for a listen-before-talk procedure and a second CAPC priority for the sidelink grant. The operations of 904 may be performed according to examples as described herein. In some implementations, aspects of the operations of 904 may be described by reference to Figure 1 The device is used to perform the above.

[0129] At 906, the method may include determining whether to utilize COT to send the sidelink transmission based on a comparison of the first CAPC priority and the second CAPC priority. The operations of 906 may be performed according to examples as described herein. In some implementations, aspects of the operations of 906 may be described by reference to Figure 1 The device is used to perform the above.

[0130] Fig.10 A flow chart of a method 1000 for supporting channel access priority of a side link according to aspects of the present disclosure is illustrated. The operations of the method 1000 may be implemented by a device or component thereof as described herein. For example, the operations of the method 1000 may be implemented by reference to Figures 1 to 4 The UE 104 described herein performs. In some implementations, the device may execute an instruction set to control functional elements of the device to perform the described functions. Additionally or alternatively, the device may use dedicated hardware to perform various aspects of the described functions.

[0131] At 1002, the method may include determining that a first CAPC priority is equal to or higher than a second CAPC priority. The operations of 1002 may be performed according to examples as described herein. In some implementations, aspects of the operations of 1002 may be described by reference to Figure 1 The device is used to perform the above.

[0132] At 1004, the method may include transmitting the sidelink transmission using the COT based at least in part on the first CAPC priority being equal to or higher than the second CAPC priority. The operations of 1004 may be performed according to examples as described herein. In some implementations, aspects of the operations of 1004 may be described with reference to Figure 1 The device is used to perform the above.

[0133] Fig.11 A flow chart of a method 1100 for supporting channel access priority of a side link according to aspects of the present disclosure is illustrated. The operations of the method 1100 may be implemented by a device or component thereof as described herein. For example, the operations of the method 1100 may be implemented by reference to Figures 1 to 4 The UE 104 described herein performs. In some implementations, the device may execute an instruction set to control functional elements of the device to perform the described functions. Additionally or alternatively, the device may use dedicated hardware to perform various aspects of the described functions.

[0134] At 1102, the method may include determining that the first CAPC priority is lower than the second CAPC priority. The operations of 1102 may be performed according to examples as described herein. In some implementations, aspects of the operations of 1102 may be described by reference to Figure 1 The device is used to perform the above.

[0135] At 1104, the method may include terminating the COT. The operations of 1104 may be performed according to examples as described herein. In some implementations, aspects of the operations of 1104 may be described by reference to Figure 1 The device is used to perform the above.

[0136] At 1106, the method may include initiating transmission of a sidelink transmission using the sidelink grant and based at least in part on the second CAPC priority. The operations of 1106 may be performed according to examples as described herein. In some implementations, aspects of the operations of 1106 may be described with reference to Figure 1 The device is used to perform the above.

[0137] Fig.12 A flow chart of a method 1200 for supporting channel access priority of a side link according to aspects of the present disclosure is illustrated. The operations of the method 1200 may be implemented by a device or component thereof as described herein. For example, the operations of the method 1200 may be implemented by reference to Figures 1 to 4 The UE 104 described herein performs. In some implementations, the device may execute an instruction set to control functional elements of the device to perform the described functions. Additionally or alternatively, the device may use dedicated hardware to perform various aspects of the described functions.

[0138] At 1202, the method may include generating a transport block including one or more MAC SDUs for one or more sidelink logical channels for sidelink transmission. The operations of 1202 may be performed according to examples as described herein. In some implementations, aspects of the operations of 1202 may be described with reference to Figure 1 The device is used to perform the above.

[0139] At 1204, the method may include processing the transport block based on a comparison of the CAPC priority of the transport block for the listen-before-talk procedure with the PDB of the transport block. The operations of 1204 may be performed according to examples as described herein. In some implementations, aspects of the operations of 1204 may be described with reference to Figure 1 The device is used to perform the above.

[0140] Fig.13 A flow chart of a method 1300 for supporting channel access priority of a side link according to aspects of the present disclosure is illustrated. The operations of the method 1300 may be implemented by a device or component thereof as described herein. For example, the operations of the method 1300 may be implemented by reference to Figures 1 to 4 The UE 104 described herein performs. In some implementations, the device may execute an instruction set to control functional elements of the device to perform the described functions. Additionally or alternatively, the device may use dedicated hardware to perform various aspects of the described functions.

[0141] At 1302, the method may include determining that a contention window for a listen-before-talk process is greater than a PDB of a transmission block, wherein the contention window is determined based on a CAPC priority. The operations of 1302 may be performed according to examples as described herein. In some implementations, aspects of the operations of 1302 may be described with reference to Figure 1 The device is used to perform the above.

[0142] At 1304, the method may include determining not to send the transport block based at least in part on a contention window of the listen-before-talk process being greater than a PDB of the transport block. The operations of 1304 may be performed according to examples as described herein. In some implementations, aspects of the operations of 1304 may be described by reference to Figure 1 The device is used to perform the above.

[0143] Fig.14A flow chart of a method 1400 for supporting channel access priority of a side link according to aspects of the present disclosure is illustrated. The operations of the method 1400 may be implemented by a device or component thereof as described herein. For example, the operations of the method 1400 may be implemented by reference to Figures 1 to 4 The UE 104 described herein performs. In some implementations, the device may execute an instruction set to control functional elements of the device to perform the described functions. Additionally or alternatively, the device may use dedicated hardware to perform various aspects of the described functions.

[0144] At 1402, the method may include determining that a contention window for a listen-before-talk process is greater than a PDB of a transmission block, wherein the contention window is determined based on a CAPC priority. The operations of 1402 may be performed according to examples as described herein. In some implementations, aspects of the operations of 1402 may be described with reference to Figure 1 The device is used to perform the above.

[0145] At 1404, the method may include adjusting the CAPC priority. The operations of 1404 may be performed according to examples as described herein. In some implementations, aspects of the operations of 1404 may be described by reference to Figure 1 The device is used to perform the above.

[0146] At 1406, the method may include determining that the contention window based on the adjusted CAPC priority is less than the PDB of the transport block. The operations of 1406 may be performed according to examples as described herein. In some implementations, aspects of the operations of 1406 may be described with reference to Figure 1 The device is used to perform the above.

[0147] At 1408, the method may include sending a transport block based at least in part on the adjusted CAPC priority. The operations of 1408 may be performed according to examples as described herein. In some implementations, aspects of the operations of 1408 may be described by reference to Figure 1 The device is used to perform the above.

[0148] Fig.15 1 is a flow chart of a method 1500 for supporting channel access priority of a side link according to aspects of the present disclosure. The operations of the method 1500 may be implemented by a device or component thereof as described herein. For example, the operations of the method 1500 may be implemented by reference to Figures 1 to 4 The UE 104 described herein performs. In some implementations, the device may execute an instruction set to control functional elements of the device to perform the described functions. Additionally or alternatively, the device may use dedicated hardware to perform various aspects of the described functions.

[0149] At 1502, the method may include determining that a contention window for a listen-before-talk process is greater than a PDB of a transmission block, wherein the contention window is determined based on a CAPC priority. The operations of 1502 may be performed according to examples as described herein. In some implementations, aspects of the operations of 1502 may be described with reference to Figure 1 The device is used to perform the above.

[0150] At 1504, the method may include adjusting the CAPC priority. The operations of 1504 may be performed according to examples as described herein. In some implementations, aspects of the operations of 1504 may be described by reference to Figure 1 The device is used to perform the above.

[0151] At 1506, the method may include determining that the contention window determined based on the adjusted CAPC priority is greater than the PDB of the transmission block. The operations of 1506 may be performed according to examples as described herein. In some implementations, aspects of the operations of 1506 may be described with reference to Figure 1 The device is used to perform the above.

[0152] At 1508, the method may include determining not to send a transport block based at least in part on the adjusted CAPC priority. The operations of 1508 may be performed according to examples as described herein. In some implementations, aspects of the operations of 1508 may be described by reference to Figure 1 The device is used to perform the above.

[0153] It should be noted that the methods described herein describe possible implementations, and that the operations and steps may be rearranged or otherwise modified, and other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0154] The various illustrative blocks and components described in conjunction with the disclosure herein may be implemented or performed with a general purpose processor, DSP, ASIC, CPU, FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration).

[0155] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or sent via a computer-readable medium as one or more instructions or codes. Other examples and implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hard wiring, or any combination of these. Features that implement the functions may also be physically located in various locations, including being distributed so that portions of the functions are implemented in different physical locations.

[0156] Computer-readable media include both non-transient computer storage media and communication media, and communication media include any medium that facilitates the transmission of computer programs from one place to another. Non-transient storage media can be any available medium that can be accessed by a general or special-purpose computer. As an example and not limitation, non-transient computer-readable media can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, disk storage or other magnetic storage devices, or can be used to carry or store desired program code devices in the form of instructions or data structures and can be accessed by a general or special-purpose computer, or any other non-transient medium of a general or special-purpose processor.

[0157] Any connection may be appropriately referred to as a computer-readable medium. For example, if the software is sent from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technology (such as infrared, radio, and microwave), the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technology (such as infrared, radio, and microwave) is included in the definition of computer-readable medium. Disks and optical disks as used herein include CDs, laser disks, optical disks, digital versatile disks (DVDs), floppy disks, and Blu-ray disks, wherein disks typically reproduce data magnetically, and optical disks reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0158] As used herein, including in the claims, "or" used in a list of items (e.g., a list of items beginning with a phrase such as "at least one of" or "one or more of" or "one or both of") represents an inclusive list, so that, for example, a list of at least one of A, B, or C represents A or B or C or AB or AC or BC or ABC (e.g., A and B and C). In addition, as used herein, the phrase "based on" should not be interpreted as a reference to a closed set of conditions. For example, an example step described as "based on condition A" may be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on." In addition, as used herein, including in the claims, a "set" may include one or more elements.

[0159] When referring to a network entity, the terms "send," "receive," or "communicate" may refer to any part of a network entity of a RAN (e.g., base station, CU, DU, RU) that communicates with another device (e.g., directly or via one or more other network entities).

[0160] The descriptions described herein in conjunction with the accompanying drawings describe example configurations and do not represent all examples that may be implemented or within the scope of the claims. The term "example" as used herein means "used as an example, instance, or illustration," rather than "preferred" or "better than other examples." The detailed description includes specific details for the purpose of providing an understanding of the described techniques. However, these techniques may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form to avoid confusing the concepts of the described examples.

[0161] The description herein is provided to enable one of ordinary skill in the art to make or use the present disclosure. Various modifications to the present disclosure will be clear to one of ordinary skill in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Therefore, the present disclosure is not limited to the examples and designs described herein, but should conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A user equipment (UE) for wireless communication, comprising: at least one memory; as well as at least one processor, the at least one processor being coupled to the at least one memory and configured to cause the UE to: generating a transport block, the transport block comprising: one or more medium access control (MAC) service data units (SDUs) for one or more sidelink logical channels for sidelink transmission; performing a listen-before-talk procedure based at least in part on one or more listen-before-talk parameters of a channel access priority class (CAPC) priority corresponding to a highest priority CAPC of the one or more sidelink logical channels having the one or more MAC SDUs in the transport block; and The transport block is sent based at least in part on a success of the listen-before-talk procedure.

2. The UE of claim 1, wherein the processor is configured to cause the UE to determine the CAPC priority based at least in part on a delay parameter of the one or more sidelink logical channels.

3. The UE according to claim 2, wherein the delay parameter comprises: A packet delay budget (PDB) for the transport block.

4. The UE of claim 1 , wherein the processor is configured to cause the UE to: select a sidelink grant for sending the transport block, and wherein sending the transport block comprises: The transport block is sent using the sidelink grant. 5 . The UE of claim 4 , wherein the processor is configured to cause the UE to: perform a sensing process to select the sidelink grant. The UE according to claim 1 , wherein the processor is configured to cause the UE to: autonomously select the CAPC priority.

7. The UE of claim 1, wherein the processor is configured to cause the UE to determine the CAPC priority based at least in part on information received from a network entity.

8. The UE according to claim 1, wherein the processor is configured to cause the UE to: generating the transport block to include one or more MAC control elements (CEs); and The CAPC priority is selected as the highest priority CAPC of the one or more MAC CEs.

9. The UE according to claim 1, wherein the processor is configured to cause the UE to: generating the transport block to include one or more sidelink broadcast control channel (SBCCH) SDUs; and The CAPC priority is selected as the highest priority CAPC for the one or more SBCCH SDUs.

10. The UE of claim 1, wherein the processor is configured to cause the UE to: generating the transport block to include one or more sidelink control channel (SCCH) SDUs; and The CAPC priority is selected as the highest priority CAPC for the one or more SCCH SDUs.

11. The UE of claim 1 , wherein the processor is configured to cause the UE to select the CAPC priority based at least in part on priority information received as part of Sidelink Control Information (SCI).

12. A user equipment (UE) for wireless communication, comprising: at least one memory; as well as at least one processor, the at least one processor being coupled to the at least one memory and configured to cause the UE to: performing a channel access procedure to obtain a channel occupation time (COT) associated with a first CAPC priority level of a listen-before-talk procedure; receiving downlink control information (DCI) specifying a sidelink grant for a listen-before-talk procedure and a second CAPC priority level for the sidelink grant; as well as Based on a comparison of the first CAPC priority and the second CAPC priority, a determination is made whether to utilize the COT to send a sidelink transmission.

13. The UE according to claim 12, wherein the processor is configured to cause the UE to: determining that the first CAPC priority is equal to or higher than the second CAPC priority; and Based at least in part on the first CAPC priority being equal to or higher than the second CAPC priority, the sidelink transmission is sent using the COT.

14. The UE according to claim 12, wherein the processor is configured to cause the UE to: Determining that the first CAPC priority is lower than the second CAPC priority; terminating the COT; and Transmission of the sidelink transmission is initiated utilizing the sidelink grant and based at least in part on the second CAPC priority level.

15. A user equipment (UE) for wireless communication, comprising: at least one memory; as well as at least one processor, the at least one processor being coupled to the at least one memory and configured to cause the UE to: generating a transport block, the transport block comprising: one or more medium access control (MAC) service data units (SDUs) for one or more sidelink logical channels for sidelink transmission; as well as The transport block is processed based on a comparison of a channel access priority class (CAPC) priority of the transport block for a listen-before-talk procedure and a packet delay budget (PDB) of the transport block.

16. The UE according to claim 15, wherein, in order to process the transport block, the processor is configured to cause the UE to: determining a contention window for the listen-before-talk process to be larger than the PDB of the transport block, wherein the contention window is determined based on the CAPC priority; and A determination is made not to send the transport block based at least in part on the contention window of the listen-before-talk procedure being greater than the PDB of the transport block.

17. The UE of claim 16, wherein the processor is configured to cause the UE to: determine that the contention window of the CAPC priority based on the listen-before-talk procedure is greater than the PDB of the transport block when one or more of the following: initialization of a channel access procedure for accessing said one or more sidelink logical channels; or After initialization of the channel access process.

18. The UE of claim 16, wherein the processor is configured to cause the UE to discard the transport block from a transport buffer.

19. The UE of claim 15, wherein, in order to process the transport block, the processor is configured to cause the UE to: determining a contention window of the listen-before-talk process to be greater than the PDB of the transport block, wherein the contention window is determined based on the CAPC priority; adjusting the CAPC priority; determining that a contention window determined based on the adjusted CAPC priority is smaller than the PDB of the transport block; as well as The transport block is sent based at least in part on the adjusted CAPC priority.

20. A processor for wireless communication, comprising: at least one controller coupled to at least one memory and configured to cause the processor to: generating a transport block, the transport block comprising: one or more medium access control (MAC) service data units (SDUs) for one or more sidelink logical channels for sidelink transmission; performing a listen-before-talk procedure based at least in part on one or more listen-before-talk parameters of a channel access priority class (CAPC) priority corresponding to a highest priority CAPC of the one or more sidelink logical channels having the one or more MAC SDUs in the transport block; and The transport block is sent based at least in part on a success of the listen-before-talk procedure.

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