Method, apparatus and computer program product of wireless communication

Abstract

The invention discloses a wireless communication method. The method comprises: performing, by a first wireless communication terminal, a detection of a persistent listen before talk (LBT) failure of sidelink transmissions on one or more sets of sidelink resources; and in response to detecting a persistent LBT failure of the sidelink transmission on a first set of the one or more sets of sidelink resources, performing, by the first wireless communication terminal, at least one of: setting the first set of sidelink resources to an unavailable set of sidelink resources, and then in response to one or more predetermined conditions being satisfied, setting the first set of sidelink resources as a set of available sidelink resources; or transmitting a persistent LBT failure indication to the second wireless communication terminal via the second set of sidelink resources.

Description

[0001] This document relates to methods, systems and devices related to wireless communications, particularly 5th generation wireless communications, and more specifically, to providing sidelink communication solutions when performing sidelink communication on an unlicensed carrier (shared spectrum).

[0002] Wireless communications are typically performed with user terminal devices and base stations. In addition, wireless communications are performed on carriers or frequency bands. Some carriers are licensed carriers, which are carriers licensed by a government or other authoritative entity to a service provider for exclusive use. Other carriers are unlicensed carriers, i.e., carriers that have not been licensed by such a government or other authoritative entity. Currently, user terminal devices communicate directly with each other on licensed carriers (i.e., without using base stations). However, it may be desirable for user terminal devices to communicate directly with each other on unlicensed carriers.

[0003] This document relates to methods, systems, and devices for sidelink communications.

[0004] One aspect of the present disclosure relates to a wireless communication method. In one embodiment, the wireless communication method includes: performing detection of a persistent listen-before-talk (LBT) failure of a side link transmission on one or more side link resource sets by a first wireless communication terminal; and in response to detecting a persistent LBT failure of a side link transmission on a first side link resource set of the one or more side link resource sets, the first wireless communication terminal performs at least one of the following operations: setting the first side link resource set to an unavailable side link resource set, and then setting the first side link resource set to an available side link resource set in response to satisfying one or more predetermined conditions; or transmitting a persistent LBT failure indication to a second wireless communication terminal via a second side link resource set.

[0005] Another aspect of the present disclosure relates to a wireless communication method. In one embodiment, the wireless communication method includes: performing detection, by a first wireless communication terminal, of persistent listen-before-talk (LBT) failures of sidelink transmissions on a plurality of sidelink resource sets.

[0006] Another aspect of the present disclosure relates to a wireless communication method. In one embodiment, the wireless communication method includes: performing detection of sidelink transmission on one or more sidelink resource sets by a first wireless communication terminal (e.g., for persistent listen-before-talk LBT failure); and suspending at least one of the following of a link associated with the first sidelink resource set: a sidelink continuous discontinuous transmission DTX counter, a radio resource control RRC reconfiguration-related timer, a radio link control RLC service data unit SDU for retransmission, or RETX_COUNT.

[0007] Another aspect of the present disclosure relates to a wireless communication method. In one embodiment, the wireless communication method includes: receiving, by a second wireless communication terminal, a first persistent listen-before-talk (LBT) failure indication from a first wireless communication terminal; and performing, by the second wireless communication terminal, at least one of the following operations in response to receiving the persistent LBT failure: transmitting a second persistent LBT failure to a wireless communication node; or selecting a second side link resource set for side link communication.

[0008] Various embodiments may preferably implement the following features:

[0009] Preferably, the side link resource set comprises at least one of a side link resource pool, a side link resource block RB set, a frequency resource range or a side link bandwidth part BWP.

[0010] Preferably, the one or more predetermined conditions include at least one of the following:

[0011] A timer expires, wherein the timer is started in response to an LBT failure indication from an LBT process on a first side link resource set, or the timer is started in response to a side link persistent LBT failure trigger according to an LBT process on a first side link resource set;

[0012] The result of the LBT procedure on the first set of side-link resources is success; or

[0013] A channel occupancy rate on the first side link resource set is lower than a first predetermined threshold.

[0014] Preferably, the one or more predetermined conditions include at least one of the following:

[0015] The first wireless communication terminal receives sidelink data or signaling from a user equipment in a first sidelink resource set;

[0016] The channel busy rate in the first side link resource set is lower than a second predetermined threshold; or

[0017] A received signal strength indicator RSSI in the first side link resource set is lower than a third predetermined threshold.

[0018] Preferably, the first wireless communication terminal receives at least one of the following from the wireless communication node: a timer value of the timer, a value of the first predetermined threshold, a value of the second predetermined threshold, or a value of the third predetermined threshold.

[0019] Preferably, in response to all configured normal transmission side link resource sets being unavailable, the first wireless communication terminal performs side link transmission via the abnormal side link resource set.

[0020] Preferably, the persistent LBT failure indication comprises an identifier of the first side link resource set.

[0021] Preferably, the first wireless communication terminal transmits side link resource set configuration information, the configuration information comprising frequency resource information associated with each identifier in the side link resource set.

[0022] Preferably, in response to the first side link resource set becoming available, the first wireless communication terminal transmits a persistent LBT failure recovery indication to the second wireless communication terminal.

[0023] Preferably, the first wireless communication terminal suspends a side link continuous discontinuous transmission DTX counter, a radio resource control RRC reconfiguration related timer, a radio link control RLC service data unit SDU for retransmission, or RETX_COUNT for a link associated with the first side link resource set.

[0024] Preferably, the sidelink continuous DTX counter, the RRC reconfiguration related timer, the RLC SDU for retransmission, or the RETX_COUNT is suspended in response to at least one of:

[0025] detecting a LBT failure on the first side link resource set;

[0026] The channel busy rate in the first side link resource set is higher than a second predetermined threshold;

[0027] The RSSI in the first side link resource set is higher than a third predetermined threshold; or

[0028] The LBT failure rate on the first side link resource set is higher than a fourth predetermined threshold.

[0029] Preferably, the suspension of the sidelink continuous DTX counter, the RRC reconfiguration related timer, the RLC SDU for retransmission, or the RETX_COUNT is cancelled in response to at least one of the following:

[0030] The first wireless communication terminal receives sidelink data or signaling from a user equipment in a first sidelink resource set;

[0031] The channel busy rate in the first side link resource set is lower than a second predetermined threshold;

[0032] The RSSI in the first side link resource set is lower than a third predetermined threshold;

[0033] The result of the LBT procedure on the first side link resource set is success;

[0034] The LBT failure rate on the first side link resource set is lower than a fourth predetermined threshold; or

[0035] The first side link resource set becomes an available side link resource set.

[0036] Preferably, in response to an LBT failure occurring in a first side link resource set among multiple side link resource sets, the first wireless communication terminal starts or restarts a timer associated with the first side link resource set, increments a counter associated with the first side link resource set, and determines whether a continuous LBT failure occurs on the first side link resource set based on the counter value of the counter.

[0037] Preferably, at least one of a sidelink continuous DTX counter, an RRC reconfiguration related timer, an RLC SDU for retransmission, or a RETX_COUNT is suspended in response to at least one of:

[0038] detecting a LBT failure on the first side link resource set;

[0039] The channel busy rate in the first side link resource set is higher than a second predetermined threshold;

[0040] The RSSI in the first side link resource set is higher than a third predetermined threshold; or

[0041] The LBT failure rate on the first side link resource set is higher than a fourth predetermined threshold.

[0042] Preferably, the suspension of at least one of the sidelink continuous DTX counter, the RRC reconfiguration related timer, the RLC SDU for retransmission, or the RETX_COUNT is cancelled in response to at least one of the following:

[0043] The first wireless communication terminal receives sidelink data or signaling from a user equipment in a first sidelink resource set;

[0044] The channel busy rate in the first side link resource set is lower than a second predetermined threshold;

[0045] The RSSI in the first side link resource set is lower than a third predetermined threshold;

[0046] The result of the LBT process on the first side link resource set is success;

[0047] The LBT failure rate on the first side link resource set is lower than a fourth predetermined threshold; or

[0048] The first side link resource set becomes an available side link resource set.

[0049] Preferably, the first wireless communication terminal performs at least one of the following operations:

[0050] In response to performing transmission of a MAC protocol data unit (PDU) and receiving an LBT failure indication from the physical layer module, instructing the physical layer module to send a negative acknowledgement signal to the wireless communication node on a physical uplink control channel (PUCCH) via the medium access control (MAC) layer module;

[0051] In response to sending a sidelink CSI report medium access control element MAC CE and not receiving an LBT failure indication from the physical layer module, stopping a sl-CSI-ReportTimer for a triggered sidelink channel state information sl-CSI report;

[0052] In response to sending a sidelink CSI report medium access control element MAC CE and not receiving an LBT failure indication from the physical layer module, canceling the triggered SL-CSI report;

[0053] In response to sending a sidelink IUC MAC CE and not receiving an LBT failure indication from the physical layer module, stopping the sl-IUC-ReportTimer for the triggered sidelink inter-UE coordination SL-IUC information reporting; or

[0054] In response to the sidelink IUC MAC CE being sent and no LBT failure indication being received from the physical layer module, the triggered SL-IUC report is cancelled.

[0055] Preferably, the second persistent LBT failure indication includes at least one of a sidelink resource set indication or a destination identifier, and the destination identifier indicates the first wireless communication terminal that detects the persistent LBT failure.

[0056] Preferably, the sidelink resource set indication comprises at least one of: a non-preferred sidelink resource set, a preferred sidelink resource set, an available sidelink resource set or an unavailable sidelink resource set.

[0057] Preferably, the second wireless communication terminal performs at least one of the following:

[0058] Selecting a resource pool for sidelink transmission from an available resource pool, wherein the available resource pool excludes an unavailable resource pool indicated by a persistent LBT failure indication;

[0059] Selecting time and frequency resources for sidelink transmission from available channels or resource blocks (RB) sets, wherein the available channels or RB sets exclude unavailable channels or RB sets indicated by a persistent LBT failure indication; or

[0060] Via the medium access control MAC layer module, the physical layer module is informed of unavailable or non-preferred channels or RB sets according to the persistent LBT failure indication.

[0061] Preferably, in response to receiving a persistent LBT failure indication, the second wireless communication terminal suspends a side link continuous discontinuous transmission DTX counter, a radio resource control RRC reconfiguration related timer, an RLC SDU for retransmission, or RETX_COUNT for a link associated with the first side link resource set.

[0062] Preferably, the suspension of the sidelink continuous DTX counter, the RRC reconfiguration related timer, the RLC SDU for retransmission, or the RETX_COUNT is cancelled in response to at least one of the following:

[0063] The second wireless communication terminal receives sidelink data or signaling from the user equipment in the first sidelink resource set;

[0064] The second wireless communication terminal receives side link data or signaling from the first wireless communication terminal;

[0065] The second wireless communication terminal determines that the first set of side link resources has become available;

[0066] The second wireless communication terminal receives a continuous LBT failure recovery indication; or

[0067] The second wireless communication terminal determines to cancel the suspension of the opposite side link continuous DTX counter, the RRC reconfiguration related timer, the RLC SDU for retransmission, or the RETX_COUNT.

[0068] The present disclosure relates to a wireless communication terminal including a communication unit and a processor. The processor is configured to implement the wireless communication method described in any one of the aforementioned methods.

[0069] The present disclosure relates to a computer program product, which includes a computer-readable program medium code stored thereon, which, when executed by a processor, causes the processor to implement the wireless communication method described in any one of the aforementioned methods.

[0070] The exemplary embodiments disclosed herein are intended to provide features that will become apparent by reference to the following description when taken in conjunction with the accompanying drawings. According to various embodiments, exemplary systems, methods, devices, and computer program products are disclosed herein. However, it should be understood that these embodiments are presented by way of example and not limitation, and it will be apparent to those of ordinary skill in the art who have read this disclosure that various modifications may be made to the disclosed embodiments while remaining within the scope of this disclosure.

[0071] Therefore, the present disclosure is not limited to the exemplary embodiments and applications described and illustrated herein. In addition, the specific order and / or hierarchy of the steps in the methods disclosed herein are merely exemplary approaches. Based on design preferences, the specific order or hierarchy of the steps of the disclosed methods or processes can be rearranged while remaining within the scope of the present disclosure. Therefore, it will be understood by those of ordinary skill in the art that the methods and techniques disclosed herein present various steps or actions in a sample order, and unless otherwise expressly stated, the present disclosure is not limited to the specific order or hierarchy presented.

[0072] In some embodiments, a device such as a network device is disclosed. The device may include one or more processors and one or more memories, wherein the one or more processors are configured to read computer codes from the one or more memories to implement any of the above methods.

[0073] In some embodiments, a computer program product is disclosed. The computer program product may include a non-transitory computer-readable program medium having computer code stored thereon, and when the computer code is executed by one or more processors, the one or more processors are caused to implement any one of the above methods.

[0074] The above and other aspects and embodiments thereof will be described in more detail in the drawings, the description and the claims.

[0075] Figure 1 A block diagram of a wireless communication system according to an embodiment of the present disclosure is shown.

[0076] Figure 2 A block diagram showing the configuration of a layer entity of a communication node according to an embodiment of the present disclosure.

[0077] Figure 3 An example of a schematic diagram of a wireless terminal according to an embodiment of the present disclosure is shown.

[0078] Figure 4 An example of a schematic diagram of a wireless network node according to an embodiment of the present disclosure is shown.

[0079] Figures 5 to 8 A flow chart of a method according to some embodiments of the present disclosure is shown.

[0080]

[0013] This specification describes various embodiments of systems, apparatuses, devices, and methods for wireless communications involving sidelink transmissions, including wireless communications in unlicensed carriers.

[0081] Figure 1A schematic diagram of a wireless communication system 100 according to an embodiment is shown, the wireless communication system 100 comprising a plurality of communication nodes (or just nodes) configured to wirelessly communicate with each other. In one embodiment, the communication nodes may include at least one user equipment 102 and at least one radio access node 104. Figure 1 The wireless communication system 100 in FIG. 1 is shown to include two user equipments 102 (including a first user equipment 102(1) and a second user equipment 102(2)), and one wireless access node 104. However, the present disclosure may cover various other examples of the wireless communication system 100, which include any of various combinations of user equipments 102 and wireless access nodes 104, including: two or more user equipments 102 without any wireless access nodes 104, only one user equipment 102 and only one wireless access node 104, only one user equipment 102 and two or more wireless access nodes 104, two or more user equipments 102 and one or more wireless access nodes 104, or two or more wireless access nodes 104 without any user equipments 102.

[0082] In one embodiment, a user device as described herein, such as user device 102, may include a single electronic device or apparatus capable of wireless communication over a network, or multiple electronic devices or apparatuses (e.g., a network of electronic devices or apparatuses). A user device may include or otherwise be referred to as a user terminal, user terminal device, or user equipment (UE). In addition, the user device may be or include, but is not limited to, a mobile device (such as a mobile phone, a smart phone, a smart watch, a tablet computer, a laptop computer, a vehicle or other vessel (powered by human power, motor or engine, such as a car, airplane, train, boat or bicycle as a non-limiting example) or a fixed or stationary device (such as a desktop computer or other computing device that is not usually moved for a long time, such as an appliance, other relatively heavy devices including the Internet of Things (IoT), or a computing device used in a commercial or industrial environment, as a non-limiting example). In various embodiments, the user device 102 may include a transceiver circuit 106 coupled to an antenna 108 to enable wireless communication with the wireless access node 104. The transceiver circuit 106 may also be coupled to a processor 110, which may also be coupled to a memory 112 or other storage device. The memory 112 may store therein instructions or codes that, when read and executed by the processor 110, cause the processor 110 to implement the various methods described herein.

[0083] In one embodiment, a wireless access node as described herein, such as wireless access node 104, may include a single electronic device or apparatus, or multiple electronic devices or apparatuses (e.g., a network of electronic devices or apparatuses), and may include one or more base stations or other wireless network access points capable of wirelessly communicating with one or more user devices and / or with one or more other wireless access points 104 over a network. In one embodiment, in various embodiments, wireless access node 104 may include a 4G LTE base station, a 5G NR base station, a 5G central unit base station, a 5G distributed unit base station, a next generation Node B (gNB), an enhanced Node B (eNB), or other similar or next generation (e.g., 6G) base station. Wireless access node 104 may include transceiver circuitry 114 coupled to antenna 116, which may include antenna tower 118 in various approaches to enable wireless communication with user device 102 or another wireless access point 104. Transceiver circuitry 114 may also be coupled to one or more processors 120, which may also be coupled to memory 122 or other storage device. The memory 122 may store therein instructions or codes that, when read and executed by the processor 120 , cause the processor 120 to implement one or more of the methods described herein.

[0084] In one embodiment, two communication nodes in the wireless system 100 (such as a user device 102 and a wireless access node 104, two user devices 102 without a wireless access node 104, or two wireless access nodes 104 without a user device 102) may be configured to communicate wirelessly with each other in or through a mobile network and / or a wireless access network according to one or more standards and / or specifications. In one embodiment, the standards and / or specifications may define rules or procedures by which communication nodes may communicate wirelessly, which may include rules and procedures for communicating in a millimeter (mm) wave band and / or rules and procedures for communicating using a multi-antenna scheme and beamforming functionality. Additionally or alternatively, the standards and / or specifications are standards and / or specifications that define radio access technologies and / or cellular technologies, such as fourth generation (4G) long term evolution (LTE), fifth generation (5G) new radio (NR), or unlicensed new radio (NR-U), as non-limiting examples.

[0085] In various embodiments, two or more communication nodes in the wireless system 100 may be configured to communicate according to vehicle networking standards and / or specifications. As used herein, a vehicle network refers to a large-scale system involving wireless communications and information exchange between vehicles, pedestrians, roadside equipment, and the Internet according to any of a variety of communication protocols and data exchange standards. Vehicle network communications can improve the performance of vehicles in terms of driving safety, traffic efficiency, usability, or user convenience functions or entertainment. In addition, in any of the various embodiments, vehicle network communications may be divided into three types: communications between vehicles (also referred to as vehicle-to-vehicle (V2V)); communications between vehicles and roadside equipment / network infrastructure (referred to as vehicle-to-infrastructure / vehicle-to-network (V2I / V2N)); and communications between vehicles and pedestrians (referred to as vehicle-to-pedestrian (V2P)). These types of communications are collectively referred to as vehicle-to-external (V2X) communications. Communication nodes participating in V2X communications may communicate with each other according to any of a variety of V2X standards or specifications.

[0086] In one embodiment, in the wireless system 100, the communication nodes are configured to communicate signals wirelessly between each other. In one embodiment, the communication between two communication nodes in the wireless system 100 can be or include transmission or reception, and is usually performed simultaneously, depending on the perspective of the specific nodes in the communication. In one embodiment, for a given communication between a first node and a second node, where the first node is transmitting a signal to the second node and the second node is receiving a signal from the first node, the first node can be referred to as a source node or a transmitting node or device, the second node can be referred to as a destination node or a receiving node or device, and the communication can be considered as transmission for the first node and reception for the second node. Of course, since the communication nodes in the wireless system 100 can both send and receive signals, a single communication node can be both a transmission / source node and a receiving / destination node at the same time, or switch between a transmission node and a receiving node.

[0087] In addition, certain signals may be characterized or defined as uplink (UL) signals, downlink (DL) signals, or sidelink (SL) signals. An uplink signal is a signal transmitted from a user equipment 102 to a wireless access node 104. A downlink signal is a signal transmitted from a wireless access node 104 to a user equipment 102. A sidelink signal is a signal transmitted from one user equipment 102 to another user equipment 102, or a signal transmitted from one wireless access node 104 to another wireless access node 104. In addition, for sidelink transmissions, the first / source user equipment 102 transmits the sidelink signal directly to the second / destination user equipment 102 without forwarding the sidelink signal to the wireless access node 104.

[0088] In embodiments involving V2X communication, the user equipment 102 may perform sidelink transmissions. Such sidelink communication in V2X may be referred to as PC5-based V2X communication or V2X communication. In addition, for sidelink communication in V2X, the user equipment 102 may communicate sidelink signals to each other using a PC5 interface, where PC5 refers to a reference point where a user equipment 102 communicates with another user equipment 102 through a direct channel.

[0089] As V2X technology advances (including in the automation industry), the scenarios for V2X communications are becoming more diverse and require higher performance. Examples of advanced V2X services include vehicle platooning, extended sensors, advanced driving (semi-autonomous driving and fully autonomous driving), and remote driving. As non-limiting examples, example performance requirements for these advanced V2X services may include: support for data packets of 50 to 12,000 bytes in size, a transmission rate of 2 to 50 messages per second, a maximum end-to-end latency of 3 to 500 milliseconds, a reliability of 90% to 99.999%, a data rate of 0.5 to 1,000 megabytes per second (Mbps), or a transmission range of 50 to 1,000 meters.

[0090] In one embodiment, a communication node using NR radio access operating with shared spectrum channel access may be configured to operate in different modes, wherein a primary cell (PCell), a primary secondary cell (PSCell), or a secondary cell (SCell) may be in a shared spectrum, and the SCell may be configured or not configured with uplink transmissions. In addition, in both channel access modes, the wireless access node 104 and the user equipment 102 may be configured to apply or perform a listen-before-talk (LBT) procedure before performing transmissions on a cell configured with shared spectrum channel access.

[0091] Figure 2 A block diagram of multiple modules of a communication node (e.g., user equipment 102 or wireless access node 104) is shown, including a physical layer (PHY) entity or module (also referred to herein as a PHY layer, a PHY module, or a PHY entity) 202, a medium access control (MAC) layer entity or module control (also referred to herein as just a MAC layer, a MAC module, or a MAC entity) 204, a radio link control (RLC) layer entity or module (also referred to herein as just a RLC layer, a RLC entity, or a RLC module) 206, a packet data convergence protocol (PDCP) layer entity or module (also referred to herein as just a PDCP layer, a PDCP entity, or a PDCP module) 208, a radio resource control (RRC) layer entity or module (also referred to herein as just a RRC layer, a RRC entity, or a RRC module) 210, and a non-access stratum (NAS) layer entity or module (also referred to herein as just a NAS layer, a NAS entity, or a NAS module) 212.

[0092] Generally speaking, unless otherwise specified, the terms "layer", "entity" and "module" used herein are used alone or in combination with each other and are used for one or more components of a communication node, an electronic device including hardware or a combination of hardware and software, such as an electronic circuit. In various embodiments, a module or entity can be considered Figure 1 The communication node of the present invention may be implemented as part, component, or using one or more components, including processor 110 / 120, memory 112 / 122, transceiver circuit 106 / 114, or antenna 108 / 116. For example, processor 110 / 120 (such as when executing computer code stored in memory 112 / 116) may perform the functions of a module or entity. In addition, in various embodiments, the functions performed by a module or entity may be defined by one or more standards or protocols, such as, for example, 5G NR.

[0093] also, Figure 2 The layer entities 202 to 212 in the MAC layer entity 204 may be higher layers and lower layers relative to each other, wherein the PHY layer entity 202 is the lowest layer among the layer entities 202 to 212; the MAC layer entity 204 is a higher layer than the PHY layer entity 202 and a lower layer than the other layer entities 206 to 212; the RLC layer entity 206 is higher than the PHY and MAC layer entities 202, 204, and lower than the PDCP, RRC, and NAS layer entities 208 to 212; the PDCP layer entity 208 is higher than the PHY, MAC, and RRC layer entities 202 to 206, and lower than the RRC and NAS layer entities 210, 212; the RRC layer entity 210 is higher than the PHY, MAC, RRC, and PDCP layer entities 202-208 and lower than the NAS layer entity 212; the NAS layer entity 212 is Figure 2 The highest level entity among the level entities 202 to 220 shown in FIG. In various embodiments, the communication nodes of system 100 may include Figure 2 Modules and / or layer entities other than those shown in .

[0094] Example 1

[0095] LBT detection for each sidelink resource set

[0096] In one embodiment, a first user device (also referred to as a first UE, a first wireless communication terminal, or UE2 in the present disclosure) may determine LBT success or LBT failure based on an LBT process, i.e., whether the LBT process results in LBT success or LBT failure. In response to LBT success, the first user device (e.g., user equipment (UE)) may transmit a side link signal to a second user device (e.g., another UE) (also referred to as a second UE, a second wireless communication terminal, or UE1 in the present disclosure); and may not transmit a side link signal in response to LBT failure.

[0097] In one embodiment, the first user equipment can determine whether there is a side link continuous LBT failure according to the LBT process. In various embodiments, the first user equipment can determine the side link continuous LBT failure by counting LBT failures in several LBT processes or iterations of the LBT process. In one embodiment, the user equipment can be configured with a side link maximum LBT failure count (SL-LBT-FailureMaxCount) for continuous LBT failure detection of the side link, a side link failure detection timer (SL-LBT-FailureDetectionTime) for continuous LBS failure detection of the side link, and a side link LBT counter (SL-LBT_counter) for LBT failure, which can be initially set to zero. In the case where the first user equipment detects an LBT failure of the LBT process, the first user equipment can start or restart the side link failure detection timer. In addition, the first user equipment can increment the side link LBT counter by one. Subsequently, the first user equipment can compare the current value of the side link LBT counter with the side link maximum LBT failure count. If the current value is greater than or equal to the side link maximum LBT failure count, the first user equipment can detect that the side link continues to fail LBT. In one embodiment, the first user equipment may use a side link failure detection timer when counting. For example, the first user equipment may count during the duration measured by the side link failure detection timer. That is, the first user equipment may determine whether a side link continuous LBT failure has occurred based on the side link LBT counter count during the duration during which the side link LBT failure detection timer is running (not expired). In response to the expiration of the side link LBT failure detection timer, or when the side link LBT failure detection timer or the side link maximum LBT failure count is reconfigured by the MAC layer (or another upper layer), the user equipment may reset the side link LBT counter to zero or another initial value.

[0098] In addition, in some embodiments, the PHY layer of the first user equipment may perform an LBT process, and / or determine whether the LBT process is successful or failed. If the PHY layer determines that the LBT fails, the PHY layer may send a side link failure indication to the MAC layer indicating the LBT failure detected by the PHY layer. In addition, the MAC layer may be configured with a side link maximum LBT failure count, a side link failure detection timer, and a side link LBT counter, and determine or detect a side link continuous LBT failure in response to receiving a side link failure indication, as described above.

[0099] However, the granularity of the (persistent) sidelink LBT failure may be a SL (sidelink) resource pool or a SL RB (resource block) set, and the first user equipment may be allowed to perform sidelink transmissions on more than one resource pool or SL RB set. In one embodiment, the first user equipment is configured with the following parameters in lbt-FailureRecoveryConfig:

[0100] -lbt-FailureInstanceMaxCount for persistent LBT failure detection; and

[0101] -lbt-FailureDetectionTimer for continuous LBT failure detection;

[0102] And the UE can maintain a lbt-FailureDetectionTime and a LBT_COUNTER for each sidelink resource set.

[0103] In one embodiment, the first user equipment may perform sidelink transmission on three sidelink resource sets, including resource set 1, resource set 2, and resource set 3. In one embodiment, the UE may maintain three lbt-FailureDetectionTimes and three LBT_COUNTERs.

[0104] For each resource set x (x may be 1, 2, or 3) of the first user equipment, if an LBT failure indication associated with resource set x has been received from a lower layer, the first user equipment starts or restarts the lbt-FailureDetectionTime associated with resource set x, increments the LBT_COUNTER associated with resource set x by 1, and determines whether the LBT_COUNT is greater than or equal to the lbt-FailureInstanceMaxCount. If so, the first user equipment triggers a persistent LBT failure for resource set x. In some embodiments, if the lbt-FailureDetectionTime associated with resource set x expires; or if the lbt-FailureDetectionTime or lbt-FailureInstanceMaxCount associated with resource set x is reconfigured by an upper layer, the first user equipment sets the LBT_COUNTER associated with resource set x to 0.

[0105] In one embodiment, the sidelink resource set may be one of: a sidelink resource pool, a sidelink resource block, a RB set, a sidelink channel, a LBT band, or a sidelink bandwidth part BWP.

[0106] Example 2

[0107] Unavailable resource set

[0108] In one embodiment, a method may include: determining, by a first user equipment, a sidelink resource set as an available sidelink resource set for sidelink transmission in response to at least one of the following:

[0109] expiration of a timer started in response to an LBT failure indication from the LBT process or in accordance with a sidelink persistent LBT failure triggered by the LBT process;

[0110] The outcome of the LBT process is a success; or

[0111] The channel occupancy rate is lower than a first predetermined threshold.

[0112] In one embodiment, a method may include determining, by a first user equipment, a sidelink resource set as an available sidelink resource set for sidelink transmission in response to at least one of the following:

[0113] receiving any sidelink data or signalling from other user equipments in the sidelink resource set; or

[0114] The channel busy rate in the side link resource set is lower than a second predetermined threshold; or

[0115] The RSSI in the side link resource set is lower than a third predetermined threshold.

[0116] In one embodiment, a method may include setting a side link resource set to an unavailable side link resource set, wherein the unavailable side link resource set includes at least one of the following: a side link resource set for which a persistent LBT failure has been detected, or a side link resource set for which a persistent LBT failure has been triggered.

[0117] In one embodiment, a method may include: in response to the first user equipment being within coverage of the wireless access node, receiving, by the first user equipment, from the wireless access node a timer value indicating when the timer expires or any predetermined threshold mentioned above or hereinafter.

[0118] In one embodiment, a method may include, in response to all configured normal sidelink resource sets being determined as unavailable sidelink resource sets, performing sidelink transmission using an abnormal sidelink resource pool with a first user equipment UE.

[0119] Example 3

[0120] After persistent LBT failure is detected

[0121] In one embodiment, after detecting a persistent LBT failure, a UE (e.g., a first user equipment or a first wireless communication terminal) sends failure information to a peer UE (e.g., a second user equipment or a second wireless communication terminal, etc.) through other resource sets, and indicates information about the resource set where the persistent LBT failure occurs. If the information only includes an ID, the UE can notify the peer UE ID in advance about the mapping relationship between the ID and the location of the resource set (e.g., a resource pool).

[0122] In one embodiment, a wireless communication method may include: detecting, by a first wireless communication terminal, a continuous listen-before-talk (LBT) failure of a side link transmission in a first side link resource set; and transmitting, by the first wireless communication terminal, continuous listen-before-talk (LBT) failure indication information to a second wireless communication terminal in a second side link resource set, the information indicating a continuous LBT failure of the side link communication.

[0123] In one embodiment, the second persistent LBT failure indication information is transmitted by at least one of the following: sidelink LBT failure MAC CE, sidelink control information, SCI or short control signaling.

[0124] In one embodiment, the second set of side link resources is a set of available side link resources.

[0125] In one embodiment, if all normal side link resource sets are unavailable side link resource sets, the second side link resource set may be abnormal side link resources.

[0126] In one embodiment, the persistent LBT failure indication information may include a side link resource set identification or identifier, which may indicate an identification or identifier of a side link resource set in which the persistent LBT failure occurs.

[0127] In one embodiment, a method may include: before a first wireless communication terminal transmits continuous LBT failure indication information to a second wireless communication terminal, the first wireless communication terminal transmits side link resource set configuration information to the second wireless communication terminal, and the configuration information may include a mapping relationship between a side link resource set identifier or identifier and frequency resource location information.

[0128] In one embodiment, in response to determining that the side link continues to fail LBT according to the LBT process, the first user equipment may send a side link LBT failure MAC control element (CE) to the wireless communication node. The wireless communication node may then allocate another side link resource set to the first user equipment. However, before that, the UE may need to continue using the current side link resource set. In one embodiment, in order to avoid releasing the PC5-RRC connection of the destination, when the first user equipment detects a side link continues to fail LBT in the side link resource set, it may suspend one or more side link continuous DTX counters (numConsecutiveDTX) or suspend one or more RRC reconfiguration related timers (T400) of one or more destination IDs associated with the side link resource set.

[0129] In one embodiment, thereafter, the first user equipment may unpause one or more sidelink continuous DTX counters (numConsecutiveDTX), or unpause one or more RRC reconfiguration-related timers (T400) of one or more destination IDs associated with the side link resource set that becomes an available side link resource set.

[0130] In one embodiment, the first user equipment may suspend a continuous DTX counter (numConsecutiveDTX) or suspend an RRC reconfiguration related timer (T400) of a sidelink of one or more destination IDs associated with a sidelink resource set in response to at least one of the following:

[0131] LBT failure detected,

[0132] A channel busy rate in the side link resource set is higher than a second predetermined threshold;

[0133] The RSSI in the side link resource set is higher than a third predetermined threshold; or

[0134] The LBT failure rate on the first side link resource set is higher than a fourth predetermined threshold (eg, within a specific time period).

[0135] In one embodiment, the first user equipment may unsuspend one or more sidelink continuous DTX counters (numConsecutiveDTX) or unsuspend one or more RRC reconfiguration-related timers (T400) for one or more destination IDs associated with the sidelink resource set in response to at least one of the following:

[0136] receiving any sidelink data or signaling from other user equipments in the sidelink resource set;

[0137] A channel busy rate in the side link resource set is lower than a second predetermined threshold;

[0138] The RSSI in the side link resource set is lower than a third predetermined threshold;

[0139] LBT is successful; or

[0140] The LBT failure rate on the first side link resource set is lower than a fourth predetermined threshold (eg, within a specific time period).

[0141] Example 4

[0142] Receiving persistent LBT failure indications from other UEs

[0143] In one embodiment, for sidelink communication, considering that the TX (transmitting) UE (UE1) and the RX (receiving) UE (UE2) are located at different locations and may be interfered by different devices, in some cases, even if a persistent LBT failure is triggered in the RX UE, the TX UE may not detect the LBT failure, so the LBT failure detection in the TX UE side does not mean the LBS failure in the RX UE side. Therefore, in order to know whether the RX UE really triggers a persistent LBT failure, one method is that the RX UE can indicate an SL-specific persistent LBT failure to the TXUE. As described above, if there are other available SL resource pools or SL RB sets, in the case where a persistent LBT failure is triggered in the current SL resource pool or SL RB set, the RX UE can switch to other available SL resource pools or SL RB sets to perform sidelink transmission. Then, the RX UE can send an SL-specific persistent LBT failure indication to the TXUE via the new available SL resource pool or SL RB set. For this case, since the TX UE does not detect the persistent LBT failure, but the RX UE detects the persistent LBT failure, which causes the TX UE to continue to perform sidelink transmission in the sidelink resource pool or RB set in which the RX UE detects the persistent LBT failure, the TX UE may not receive any HARQ feedback until the SL resource pool or SL RB set associated with the RX UE is available again. To solve this problem, the TX UE may consider changing the sidelink resource set to perform sidelink transmission.

[0144] In one embodiment, if a persistent LBT failure indication is received from UE2 (e.g., the first user equipment or the first wireless communication terminal as described above), UE1 (e.g., the second user equipment or the second wireless communication terminal as described above) may send the persistent LBT failure indication received from UE2 to a base station (e.g., gNB).

[0145] In one embodiment, the destination identification and the persistent LBT failure indication received from UE2 may be included in a SidelinkUEinformationNR message.

[0146] In one embodiment, sl-Failure may be set in the SL-Failure information element included in the SidelinkUEinformationNR message to a persistent LBT failure for the associated destination.

[0147] In one embodiment, UE1 may send a persistent LBT failure indication received from UE2 to the base station, where the persistent LBT failure indication includes a sidelink resource set indication.

[0148] In one embodiment, a resource set indication may be used to indicate one or more channel indications.

[0149] In one embodiment, a channel may refer to a carrier or a portion of a carrier consisting of a set of consecutive resource blocks (RBs) on which a channel access procedure is performed in a shared spectrum.

[0150] In one embodiment, the resource set indication may be used to indicate one or more resource block sets or one or more resource pools.

[0151] In one embodiment, the sidelink resource set indication includes at least one of the following: a non-preferred sidelink resource set, a preferred sidelink resource set, an available sidelink resource set, or an unavailable sidelink resource set. The network (e.g., gNB) can then consider this information when allocating sidelink resources to the UE.

[0152] In one embodiment, if a persistent LBT failure indication is received from UE2 and UE1 is configured to perform side link resource allocation mode 2, UE1 may regard the resource pool indicated in the received persistent LBT failure indication message as an unavailable resource pool, or remove the resource pool indicated in the received persistent LBT failure indication message from the candidate resource pool.

[0153] Afterwards, UE1 may select any resource pool from the candidate resource pools or the available resource pools.

[0154] In one embodiment, UE1 may regard the channel or RB set indicated in the received persistent LBT failure indication message as an unavailable channel or RB set, or remove the resource pool indicated in the received persistent LBT failure indication message from the candidate channel or RB set.

[0155] Thereafter, the MAC entity of UE1 may indicate to the physical layer the unavailable or non-preferred channels or RB sets in one or more destination UEs so that the physical layer can avoid using the unavailable or non-preferred channels or RB sets.

[0156] In one embodiment, UE1 may select time and frequency resources for transmission from resources indicated by the physical layer within a candidate or available channel or RB set.

[0157] In one embodiment, a channel refers to a carrier or a portion of a carrier consisting of a set of consecutive resource blocks (RBs) on which a channel access procedure is performed in a shared spectrum.

[0158] Example 5

[0159] Receiving a persistent LBT failure indication from another UE

[0160] In one embodiment, when the user equipment (eg, UE1 described above) receives the sidelink persistent LBT failure indication information of the destination ID, the RLF (Radio Link Failure) due to HARQ DTX may be processed as follows.

[0161] In one embodiment, when the first user equipment wants to communicate with the second user equipment via unicast mode, the first user equipment and the second user equipment may first establish a PC5-RRC connection (also referred to as a PC5 link) with each other. Since the user equipment can communicate with multiple user equipments, such as for different types of services, the user equipment may establish multiple PC5-RRC connections with these user equipments. The user equipment may use a destination ID to uniquely identify the PC5-RRC connection it has established with another user equipment. As a non-limiting example, after the first user equipment and the second user equipment establish a PC5-RRC connection, they may exchange various information, including UE capability information, an RRC configuration message including measurement configuration information, or bearer configuration information.

[0162] In addition, the first user equipment may detect a radio link failure (RLF) of the PC5-RRC connection established by it with the second user equipment. After detecting the RLF, the first user equipment may release the PC5-RRC connection, which may include releasing the DRB of the PC5-RRC connection and / or discarding the NR side link communication configuration information of the PC5-RRC connection.

[0163] In one embodiment, in response to detecting that the number of consecutive hybrid automatic repeat request (HARQ) discontinuous transmissions (DTX) has reached a maximum number of consecutive HARQ DTXs (sl-maxNumConsecutiveDTX), the first user device may determine the RLF of the PC5-RRC connection. Generally speaking, the user device may detect the number of consecutive resources configured with a physical sidelink feedback channel (PSFCH) that have not received HARQ feedback messages. The first user device may track the current number of consecutive DTXs (numConsecutiveDTX). If the current number reaches or exceeds the maximum number, the first user device may detect the RLF. Therefore, in various embodiments, the first user device may determine whether there is no PSFCH reception at the PSFCH reception opportunity. If so, the first user device may increment the current count (numConsecutiveDTX) by one. Then, the first user device may compare whether the current count has reached the maximum value. If so, the first user device may detect the RLF of the PC5-RRC connection (also known as the HARQ-based sidelink RLF). In addition, for at least some embodiments, the MAC layer tracks the current count and determines whether RLF has occurred by comparing the current count to the maximum number. If the MAC layer detects RLF, the MAC layer may notify the RRC layer.

[0164] In some cases where a first user equipment and a second user equipment communicate on an unlicensed carrier, if the second user equipment performs an LBT procedure and the result is an LBT failure, the second user equipment may not be able to send HARQ feedback to the first user equipment. In the case where the first user equipment and the second user equipment communicate on a licensed carrier, continuous HARQ DTX most often occurs because the first user equipment and the second user equipment are far away from each other. For the case where the first user equipment and the second user equipment communicate on an unlicensed carrier, continuous HARQ DTX may occur because the first user equipment and the second user equipment are far away from each other and also because it is easier to reach the maximum number of continuous HARQ DTXs for a particular destination. However, if the maximum number of continuous HARQ DTXs is due to continuous LBT failures, the user equipment may not want to release the PC5-RRC connection of the destination.

[0165] In one embodiment, the first user equipment may be configured with a maximum number of consecutive HARQ DTXs in order to detect RLF. In some embodiments, the first user equipment may receive the maximum number of consecutive HARQ DTXs from the wireless access node 104. In one embodiment, the first user equipment may be pre-configured with a maximum number of consecutive HARQ DTXs. In one embodiment, the first user equipment may maintain a count (numConsecutiveDTX), and if the first user equipment determines that there is no PSCCH reception at the PSFCH reception opportunity, the first user equipment may increment the current count (numConsecutiveDTX) by one. In one embodiment, if the first user equipment receives a side link continuous LBT failure indication message indicating a side link continuous LBT failure from the second UE, the first user equipment may determine that the continuous HARQ DTX is caused by the continuous LBT failure, rather than by the second user equipment moving away. In one embodiment, in order to avoid releasing the PC5-RRC connection of the destination, when the first user equipment receives a side link continuous LBT failure indication message indicating a side link continuous LBT failure from the second UE, it may suspend the side link continuous DTX counter (numConsecutiveDTX).

[0166] In one embodiment, in response to at least one of the first user equipment receiving any data in the associated side link resource set; or the first user equipment receiving any data from the second UE; or the first user equipment determining that the associated side link resource set becomes available, the first user equipment may cancel the suspension of the side link continuous DTX counter (numConsecutiveDTX).

[0167] Example 6

[0168] Received LBT failure indication

[0169] In one embodiment, when the user equipment receives the side link continuous LBT failure indication information of the destination id, the RLF caused by the expiration of the timer can be handled as follows.

[0170] In one embodiment, the first user may detect the RLF of the PC5-RRC connection between the first user equipment and the second user equipment. The first user equipment may determine to perform a sidelink RRC reconfiguration process. Correspondingly, the first user equipment may transmit a sidelink RRC reconfiguration message to the second user equipment. After sending the RRC reconfiguration sidelink message, the first user equipment may also start a timer Tx (e.g., timer T400 or another timer) for the associated destination id. If the first user equipment receives a sidelink RRC reconfiguration completion message or a sidelink RRC reconfiguration failure message from the second user equipment before the timer expires, the first user equipment may stop the timer Tx for the associated destination id.

[0171] In one embodiment, if the timer Tx for a specific destination has expired, the first user equipment may consider that a sidelink radio link failure for the destination has been detected.

[0172] However, according to one embodiment, if a sidelink continuous LBT failure occurs to the second user, it may not send a sidelink RRC reconfiguration complete message or a sidelink RRC reallocation failure message. Instead, it may send a sidelink continuous LBT failure indication. In one embodiment, when the first user equipment receives a sidelink continuous LBT failure indication from the second user equipment, it may suspend the timer Tx (e.g., timer T400 or other timer) of the associated destination id. Therefore, the first user equipment can avoid releasing the PC5-RRC connection of the destination that is not moved away.

[0173] In one embodiment, in response to the first user equipment receiving any data in the associated side link resource set; or the first user equipment receiving any data from the second UE; or the first user equipment determining that the associated side link resource set becomes available, the first user equipment may cancel the suspension of the timer Tx (e.g., timer T400 or other timer) of the associated destination ID.

[0174] Example 7

[0175] In one embodiment, upon receiving an indication from the sidelink RLC entity that a maximum number of retransmissions for a particular destination has been reached, the first user equipment may detect a RLF of the PC5-RRC connection between the first user equipment and the second user equipment. RETX_COUNT is a counter for counting the number of retransmissions in the RLC entity.

[0176] If the second user equipment has a sidelink persistent LBT failure, the first user equipment may suspend RLC SDU (Service Data Unit) for retransmission; or suspend RETX_COUNT. Then, if RLC SDU or RETX_COUNT for retransmission is suspended, the first user equipment may not detect RLF because the maximum number of retransmissions for a specific destination will not have been reached.

[0177] In another embodiment, if the first user equipment detects that the sidelink continues to fail LBT, the first user equipment may suspend RLC SDU for retransmission; or suspend RETX_COUNT.

[0178] In one embodiment, in response to the first user equipment receiving any data in the associated side link resource set; or the first user equipment receiving any data from the second user equipment; or the first user equipment determining that the associated side link resource set becomes available, the first user equipment may cancel the suspension of the RLC SDU for retransmission, or cancel the suspension of the RETX_COUNT of the associated destination ID in the RLC entity.

[0179] Example 8

[0180] LBT failure on PUCCH and MAC CE

[0181] In one embodiment, if sl-PUCCH-Config is configured for the UE through RRC signaling, the MAC entity can determine whether the most recent transmission of the MAC PDU has been performed for the PUCCH transmission opportunity and whether an LBT failure indication has been received from a lower layer. If so, the MAC entity can instruct the physical layer to send a negative confirmation signal on the PUCCH. This means that the sidelink transmission was not actually performed due to the LBT failure, so the UE can send a negative confirmation to the network on the PUCCH. The network can then allocate another sidelink resource for the UE for retransmission.

[0182] CSI Report

[0183] In some embodiments, a sidelink channel state information (SL-CSI) reporting procedure is used to provide sidelink channel state information to a peer UE.

[0184] RRC signaling configures the following parameters to control the SL-CSI reporting process:

[0185] -sl-LatencyBoundCSI-Report, which is maintained for each PC5-RRC connection.

[0186] The MAC entity maintains a sl-CSIReportTimer for each pair of source layer-2 ID and destination layer-2 ID corresponding to the PC5-RRC connection. The sl-CSIReportTimer is used by the SL-CSI reporting UE to comply with the latency requirement issued by the CSI triggering UE. The value of sl-CSIReportTimer is the same as the latency requirement of the SL-CSI report in the sl-latencyBoundCSI-Report configured by the RRC.

[0187] For each pair of source Layer-2ID and destination Layer-2ID corresponding to the PC5-RRC connection established by the upper layer, the MAC entity can determine whether the SL-CSI report has been triggered by the SCI and has not been canceled, and whether the sl-CSIReportTimer of the triggered SL-CSI report has expired.

[0188] If the SL-CSI report has been triggered by the SCI and has not been canceled, and the sl-CSIReportTimer of the triggered SL-CSI report has not expired, the MAC entity can determine whether the MAC entity has allocated SL resources for new transmission and whether the SL-SCH resources can accommodate the SL-CSI report MAC CE and its subheader due to logical channel priority. If so, the MAC entity can also determine whether the sidelink CSI report MAC CE has been sent and whether the LBT failure indication has not been received from the lower layer. If so, the MAC entity can stop the sl-CSIReportTimer of the triggered SL-CSI report and cancel the triggered SL-CSI report. On the contrary, if the sidelink CSI report MAC CE is not sent, or an LBT failure indication is received from the lower layer, the MAC entity may not stop the sl-CSIReportTimer for the triggered SL-CSI report and will not cancel the triggered SL-CSI report.

[0189] In some embodiments, a MAC entity configured with sidelink resource allocation mode 1 may trigger a scheduling request if transmission of a pending SL-CSI report with one or more sidelink grants cannot meet the latency requirements associated with the SL-CSI reporting.

[0190] In some embodiments, RRC signaling can configure the following parameters to control the SL-IUC information reporting process:

[0191] -sl-LatencyBoundIUC-Report, which is maintained for each PC5-RRC connection.

[0192] In some embodiments, the MAC entity maintains a sl-IUC-ReportTimer for each pair of source layer-2 ID and destination layer-2 ID corresponding to the PC5-RRC connection. The sl-IUC-ReportTimer is used by the SL-IUC information reporting UE to comply with the latency requirement issued by the IUC information triggering UE. The value of the sl-IUC-ReportTimer is the same as the latency requirement of the SL-IUC information in the sl-latencyBoundIUC-Report configured by the RRC.

[0193] For each pair of source layer-2ID and destination layer-2ID corresponding to the PC5-RRC connection established with the upper layer, the MAC entity can determine whether the SL-IUC information report has been triggered by the SL-IUC request MAC CE (and / or SCI) and has not been canceled. If so, the MAC entity can also determine whether the sl-IUC-ReportTimer of the triggered SL-IUC information report is not running, or whether the sl-IUC-ReportTimer of the triggered SL-IUC information report has expired.

[0194] If the sl-IUC-ReportTimer of the triggered SL-IUC information report is running and the sl-IUC-ReportTimer of the triggered SL-IUC information report has not expired, the MAC entity may further determine whether the MAC entity has SL resources allocated for new transmission and whether the SL-SCH resources can accommodate the SL-IUC message MAC CE and its subheader due to logical channel priority. If so, the MAC entity may also determine whether the sidelink IUC MAC CE is transmitted and no LBT failure indication is received from the lower layer. If so, the MAC entity may stop the sl-IUC-ReportTimer of the triggered SL-IUC report and cancel the triggered SL-IUC report. On the contrary, if the sidelink IUC report MAC CE is not sent, or an LBT failure indication is received from the lower layer, the MAC entity may not stop the sl-IUC-ReportTimer of the triggered SL-IUC report and will not cancel the triggered SL-IUC report.

[0195] In some embodiments of the present disclosure, persistent sidelink LBT failure may be detected for each sidelink resource set, and the sidelink resource set may be one of: a sidelink resource pool, a sidelink resource block RB set, a sidelink channel, a LBT band, or a sidelink bandwidth part BWP.

[0196] In some embodiments of the present disclosure, it is described how to determine an unavailable side link resource set as an available side link resource set and when to use an abnormal side link resource pool.

[0197] In some embodiments of the present disclosure, when a UE detects a persistent LBT failure in a first resource set, it may send persistent LBS failure information in a second resource set to a peer UE, and the persistent LBT failure information includes resource set information. If only a resource set ID is included, the UE may send a mapping relationship between the resource set ID and the resource location (e.g., information on the time and / or frequency location).

[0198] In some embodiments of the present disclosure, a determination is made as to when to suspend and unsuspend the DTX counter or T400.

[0199] In some embodiments of the present disclosure, after receiving a persistent LBT failure indication from a first UE, the second UE may report the persistent LBT failure indication to the base station; the second UE may consider setting the associated side link RB or resource pool to be unavailable; perform resource reselection; and / or suspend the DTX counter or.

[0200] In some embodiments of the present disclosure, operations for LBT failure on PUCCH and MAC CE are also provided.

[0201] Figure 3 A schematic diagram of a wireless terminal 30 according to an embodiment of the present disclosure is provided. The wireless terminal 30 may be a user equipment (UE), a mobile phone, a laptop, a tablet computer, an e-book, or a portable computer system, and is not limited thereto. The wireless terminal 30 may include a processor 300, such as a microprocessor or an application-specific integrated circuit (ASIC), a storage unit 310, and a communication unit 320. The storage unit 310 may be any data storage device that stores program code 312 accessed and executed by the processor 300. Embodiments of the storage unit 312 include, but are not limited to, a subscriber identity module (SIM), a read-only memory (ROM), a flash memory, a random access memory (RAM), a hard disk, and an optical data storage device. The communication unit 320 may be a transceiver, and is used to transmit and receive signals (e.g., messages or data packets) according to the processing results of the processor 300. In one embodiment, the communication unit 320 communicates with the communication unit 320 via Figure 3 At least one antenna 322 is shown for transmitting and receiving signals.

[0202] In one embodiment, the storage unit 310 and the program code 312 may be omitted, and the processor 300 may include the storage unit with the stored program code.

[0203] The processor 300 may implement any one of the steps of the exemplary embodiments on the wireless terminal 30 , for example, by executing the program code 312 .

[0204] The communication unit 320 may be a transceiver. The communication unit 320 may alternatively or additionally combine a transmitting unit and a receiving unit configured to transmit and receive signals to and from a wireless network node (eg, a base station), respectively.

[0205] Figure 4 A schematic diagram of a radio network node 40 according to an embodiment of the present disclosure is provided. The radio network node 40 may be a satellite, a base station (BS), a network entity, a mobility management entity (MME), a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), a radio access network (RAN) node, a next generation RAN (NG-RAN) node, a gNB, an eNB, a gNB central unit (gNB-CU), a gNB distributed unit (gNB-DU), a data network, a core network or a radio network controller (RNC) and is not limited thereto. In addition, the radio network node 40 may include (execute) at least one network function, such as an access and mobility management function (AMF), a session management function (SMF), a user location function (UPF), a policy control function (PCF), an application function (AF), etc. The radio network node 40 may include a processor 400, such as a microprocessor or an ASIC, a storage unit 410 and a communication unit 420. The storage unit 410 may be any data storage device that stores a program code 412 accessed and executed by the processor 400. Examples of the storage unit 412 include, but are not limited to, a SIM, a ROM, a flash memory, a RAM, a hard disk, and an optical data storage device. The communication unit 420 may be a transceiver and is used to transmit and receive signals (e.g., messages or data packets) according to the processing results of the processor 400. In one example, the communication unit 420 communicates with the processor 400 via a Figure 4 At least one antenna 422 is shown for transmitting and receiving signals.

[0206] In one embodiment, storage unit 410 and program code 412 may be omitted. Processor 400 may include a storage unit with stored program code.

[0207] The processor 400 may implement any of the steps described in the exemplary embodiments on the radio network node 40 , for example, by executing the program code 412 .

[0208] The communication unit 420 may be a transceiver. The communication unit 420 may alternatively or additionally be configured as a transmitting unit and a receiving unit for transmitting and receiving signals to and from a wireless terminal (eg, a user equipment or another wireless network node), respectively.

[0209] Figures 5 to 8 A flowchart of a wireless communication method according to some embodiments of the present disclosure is shown.

[0210] like Figure 5 As shown, in one embodiment, a wireless communication method includes: a first wireless communication terminal performs detection on a continuous listen-before-talk (LBT) failure of a side link transmission on one or more side link resource sets; and the first wireless communication terminal, in response to detecting a continuous LBT failure of the side link transmission on a first side link resource set of the one or more side link resource sets, performs at least one of the following operations: sets the first side link resource set to an unavailable side link resource set, and then sets the first side link resource set to an available side link resource set in response to satisfying one or more predetermined conditions; or transmits a continuous LBT failure indication to a second wireless communication terminal via a second side link resource set.

[0211] like Figure 6 As shown, in one embodiment, a wireless communication method includes: a first wireless communication terminal performs detection of continuous listen-before-talk (LBT) failures of sidelink transmissions on multiple sidelink resource sets.

[0212] like Figure 7 As shown, in one embodiment, a wireless communication method includes: performing detection of sidelink transmission on one or more sidelink resource sets by a first wireless communication terminal (for example, for continuous listen-before-talk (LBT) failure); and suspending at least one of the following of the link associated with the first sidelink resource set: a sidelink continuous discontinuous transmission DTX counter, a radio resource control RRC reconfiguration related timer, a radio link control RLC service data unit SDU for retransmission, or RETX_COUNT.

[0213] like Figure 8 As shown, in one embodiment, a wireless communication method includes: receiving a first continuous listen-before-talk (LBT) failure indication by a second wireless communication terminal from a first wireless communication terminal; and in response to receiving the continuous LBT failure, performing at least one of the following operations by the second wireless communication terminal: transmitting a second continuous LBT failure to a wireless communication node; or selecting a second side link resource set for side link communication.

[0214] The details in this regard can be determined by referring to the above paragraphs and will not be repeated here.

[0215] Although various embodiments of the present disclosure have been described above, it should be understood that they are presented only by way of example and not by way of limitation. Similarly, various figures may depict example architectures or configurations, which are provided to enable those of ordinary skill in the art to understand the exemplary features and functions of the present disclosure. However, these personnel will understand that the present disclosure is not limited to the example architectures or configurations shown, but can be implemented using a variety of alternative architectures and configurations. In addition, as will be understood by those of ordinary skill in the art, one or more features of an embodiment can be combined with one or more features of another embodiment described herein. Therefore, the breadth and scope of the present disclosure should not be limited by any of the exemplary embodiments described above.

[0216] It should also be understood that any reference to an element using names such as "first," "second," etc., herein generally does not limit the number or order of these elements. Instead, these names may be used herein as a convenient means of distinguishing two or more elements or instances of an element. Thus, referring to a first element and a second element does not mean that only two elements can be used, or that the first element must precede the second element in some way.

[0217] In addition, those skilled in the art will understand that information and signals can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, and symbols that can be referenced in the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0218] Those skilled in the art will further understand that any of the various illustrative logical blocks, units, processors, devices, circuits, methods, and functions described in conjunction with the aspects disclosed herein may be implemented via electronic hardware (e.g., digital implementations, analog implementations, or a combination of both), firmware, various forms of programs or design codes containing instructions (for convenience, may be referred to herein as "software" or "software units"), or any combination of these technologies.

[0219] In order to clearly illustrate this interchangeability of hardware, firmware and software, various illustrative components, blocks, units, circuits and steps have been generally described above with respect to their functionality. Such functions are implemented in hardware, firmware or software or a combination of these technologies, depending on the specific application and the design constraints imposed on the entire system. Those skilled in the art can implement the described functions in various ways for each specific application, but this implementation decision will not lead to deviation from the scope of the present disclosure. According to various embodiments, processors, devices, components, circuits, structures, machines, units, etc. may be configured to perform one or more functions described herein. The term "configured to" or "configured for" used herein with respect to a specified operation or function refers to a processor, device, component, circuit, structure, machine, unit, etc. that is physically constructed, programmed and / or arranged to perform a specified operation or function.

[0220] In addition, the technician will understand that the various illustrative logic blocks, units, devices, components and circuits described herein can be implemented or performed in an integrated circuit (IC), which can include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, or any combination thereof. The logic blocks, units and circuits may also include antennas and / or transceivers to communicate with various components within a network or within a device. The general-purpose processor can be a microprocessor, but in an alternative, the processor can be any conventional processor, controller or state machine. The processor can also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a DSP core, or any other suitable configuration for performing the functions described herein. If implemented in software, the function can be stored as one or more instructions or codes on a computer-readable medium. Therefore, the steps of the method or algorithm disclosed herein can be implemented as software stored on a computer-readable medium.

[0221] Computer-readable media include computer storage media and communication media, which include any media that enable a computer program or code to be transferred from one place to another. Storage media can be any available media that can be accessed by a computer. By way of example and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other media that can be used to store desired program code in the form of instructions or data structures and can be accessed by a computer.

[0222] In this document, the term "unit" as used herein refers to software, firmware, hardware, and any combination of these elements for performing the relevant functions described herein. In addition, for ease of discussion, various units are described as independent units; however, it is obvious to a person skilled in the art that two or more units can be combined to form a single unit that performs relevant functions according to embodiments of the present disclosure.

[0223] In addition, memory or other memory and communication components may be used in embodiments of the present disclosure. It should be understood that, for the sake of clarity, the above description has described embodiments of the present disclosure with reference to different functional units and processors. However, it will be apparent that any appropriate functional distribution may be used between different functional units, processing logic elements or domains without departing from the present disclosure. For example, functions shown as being performed by different processing logic elements or controllers may be performed by the same processing logic element or controller. Therefore, references to specific functional units are only references to appropriate means for providing the described functions, rather than to strict logical or physical structures or instructions for organization.

[0224] Various modifications to the embodiments described in this disclosure will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the scope of the claims. Therefore, the present disclosure is not intended to be limited to the embodiments shown herein, but is to be given the widest scope consistent with the novel features and principles disclosed herein, as described in the claims.

Claims

1. A wireless communication method, comprising: Performing, by the first wireless communication terminal, detection of a persistent listen-before-talk (LBT) failure for sidelink transmissions on one or more sidelink resource sets; as well as In response to detecting a persistent LBT failure of the sidelink transmission on a first sidelink resource set of the one or more sidelink resource sets, performing at least one of the following operations by the first wireless communication terminal: setting the first side link resource set as an unavailable side link resource set, and, thereafter, in response to one or more predetermined conditions being satisfied, setting the first side link resource set as an available side link resource set; or A persistent LBT failure indication is transmitted to the second wireless communication terminal via the second set of side link resources.

2. The wireless communication method according to claim 1, wherein: The side link resource set includes at least one of a side link resource pool, a side link resource block RB set, a frequency resource range or a side link bandwidth part BWP.

3. The wireless communication method according to claim 1 or 2, wherein: The one or more predetermined conditions include at least one of the following: A timer times out, wherein the timer is started in response to an LBT failure indication from an LBT process on the first side link resource set, or the timer is started in response to a side link continuous LBT failure trigger according to the LBT process on the first side link resource set; The result of the LBT procedure on the first side link resource set is success; or A channel occupancy rate on the first side link resource set is lower than a first predetermined threshold.

4. The wireless communication method according to any one of claims 1 to 3, wherein: The one or more predetermined conditions include at least one of the following: The first wireless communication terminal receives sidelink data or signaling from a user equipment in the first sidelink resource set; The channel busy rate in the first side link resource set is lower than a second predetermined threshold; or A received signal strength indicator RSSI in the first side link resource set is lower than a third predetermined threshold.

5. The wireless communication method according to claim 3 or 4, wherein: The first wireless communication terminal receives at least one of the following from a wireless communication node: a timer value of the timer, a value of the first predetermined threshold, a value of the second predetermined threshold, or a value of the third predetermined threshold.

6. The wireless communication method according to any one of claims 1 to 5, wherein: In response to all configured normal transmission side link resource sets being unavailable, the first wireless communication terminal performs the side link transmission through an abnormal side link resource set.

7. The wireless communication method according to any one of claims 1 to 6, wherein: The persistent LBT failure indication includes an identifier of the first side link resource set.

8. The wireless communication method according to any one of claims 1 to 7, wherein: The first wireless communication terminal transmits sidelink resource set configuration information, the sidelink resource set configuration information including frequency resource information associated with each identifier in the sidelink resource set.

9. The wireless communication method according to any one of claims 1 to 8, wherein: In response to the first side link resource set becoming available, the first wireless communication terminal transmits a persistent LBT failure recovery indication to the second wireless communication terminal.

10. The wireless communication method according to any one of claims 1 to 9, wherein: The first wireless communication terminal suspends a side link continuous discontinuous transmission DTX counter, a radio resource control RRC reconfiguration related timer, a radio link control RLC service data unit SDU for retransmission, or RETX_COUNT for the link associated with the first side link resource set.

11. The wireless communication method according to claim 10, wherein: Suspending the sidelink continuous DTX counter, the RRC reconfiguration related timer, the RLC SDU for retransmission, or the RETX_COUNT in response to at least one of: detecting a LBT failure on the first side link resource set; The channel busy rate of the first side link resource set is higher than a second predetermined threshold; The RSSI in the first side link resource set is higher than a third predetermined threshold; or The LBT failure rate on the first side link resource set is higher than a fourth predetermined threshold.

12. The wireless communication method according to claim 10 or 11, wherein: The suspension of the sidelink continuous DTX counter, the RRC reconfiguration related timer, the RLC SDU for retransmission, or the RETX_COUNT is cancelled in response to at least one of: The first wireless communication terminal receives sidelink data or signaling from a user equipment in the first sidelink resource set; The channel busy rate of the first side link resource set is lower than a second predetermined threshold; The RSSI in the first side link resource set is lower than a third predetermined threshold; The result of the LBT process on the first side link resource set is success; The LBT failure rate on the first side link resource set is lower than a fourth predetermined threshold; or The first side link resource set becomes an available side link resource set.

13. A wireless communication method, comprising: Detection of persistent listen-before-talk (LBT) failures for sidelink transmissions on multiple sets of sidelink resources is performed by the first wireless communication terminal.

14. The wireless communication method according to claim 13, wherein: In response to an LBT failure occurring in a first side link resource set among the multiple side link resource sets, the first wireless communication terminal starts or restarts a timer associated with the first side link resource set, increments a counter associated with the first side link resource set, and determines whether a persistent LBT failure occurs on the first side link resource set based on the count value of the counter.

15. A wireless communication method, comprising: performing, by the first wireless communication terminal, detection of sidelink transmissions on one or more sets of sidelink resources; as well as At least one of the following is suspended for the link associated with the first side link resource set: a side link discontinuous transmission DTX counter, a radio resource control RRC reconfiguration related timer, a radio link control RLC service data unit SDU for retransmission, or RETX_COUNT.

16. The wireless communication method according to claim 15, wherein: In response to at least one of the following, at least one of a sidelink discontinuous transmission (DTX) counter, an RRC reconfiguration-related timer, an RLC SDU for retransmission, or a RETX_COUNT is suspended: detecting a LBT failure on the first side link resource set; The channel busy rate of the first side link resource set is higher than a second predetermined threshold; The RSSI in the first side link resource set is higher than a third predetermined threshold; or The LBT failure rate on the first side link resource set is higher than a fourth predetermined threshold.

17. The wireless communication method according to claim 15 or 16, wherein: In response to at least one of the following, canceling the suspension of at least one of the sidelink discontinuous DTX counter, the RRC reconfiguration related timer, the RLC SDU for retransmission, or RETX_COUNT: The first wireless communication terminal receives sidelink data or signaling from a user equipment in the first sidelink resource set; The channel busy rate of the first side link resource set is lower than a second predetermined threshold; The RSSI in the first side link resource set is lower than a third predetermined threshold; The result of the LBT process on the first side link resource set is success; The LBT failure rate on the first side link resource set is lower than a fourth predetermined threshold; or The first side link resource set becomes an available side link resource set.

18. The wireless communication method according to any one of claims 1 to 17, wherein: The first wireless communication terminal performs at least one of the following operations: In response to performing transmission of a MAC protocol data unit (PDU) and receiving an LBT failure indication from a physical layer module, instructing the physical layer module to send a negative acknowledgement signal to the wireless communication node on a physical uplink control channel (PUCCH) via a medium access control (MAC) layer module; In response to sending a sidelink CSI report medium access control element MAC CE and not receiving an LBT failure indication from the physical layer module, stopping an sl-CSI-ReportTimer for a triggered sidelink channel state information SL-CSI report; In response to sending a sidelink CSI report medium access control element MAC CE and not receiving an LBT failure indication from the physical layer module, canceling the triggered SL-CSI report; In response to sending a sidelink IUC MAC CE and not receiving an LBT failure indication from the physical layer module, stopping a sl-IUC-ReportTimer for a triggered sidelink inter-UE coordinated SL-IUC information report; or In response to the sidelink IUC MAC CE being sent and no LBT failure indication being received from the physical layer module, the triggered SL-IUC report is cancelled.

19. A wireless communication method, comprising: Receiving, by the second wireless communication terminal, a first continuous listen-before-talk (LBT) failure indication from the first wireless communication terminal; as well as In response to receiving the persistent LBT failure, the second wireless communication terminal performs at least one of the following operations: Transmitting a second persistent LBT failure to the wireless communication node; or A second set of sidelink resources is selected for sidelink communications.

20. The wireless communication method according to claim 19, wherein: The second persistent LBT failure indication includes at least one of a side link resource set indication or a destination identifier, and the destination identifier indicates the first wireless communication terminal that detects the persistent LBT failure.

21. The wireless communication method according to claim 20, wherein: The sidelink resource set indication includes at least one of the following: a non-preferred sidelink resource set, a preferred sidelink resource set, an available sidelink resource set, or an unavailable sidelink resource set.

22. The wireless communication method according to any one of claims 19 to 21, wherein: The second wireless communication terminal performs at least one of the following: Selecting a resource pool for sidelink transmission from an available resource pool, wherein the available resource pool excludes an unavailable resource pool indicated by the persistent LBT failure indication; Selecting time and frequency resources for the sidelink transmission from available channels or resource blocks (RB) set, wherein the available channels or RB set excludes unavailable channels or RB sets indicated by the persistent LBT failure indication; or Via the medium access control MAC layer module, the unavailable or non-preferred channel or RB set is indicated to the physical layer module according to the persistent LBT failure indication.

23. The wireless communication method according to any one of claims 19 to 22, wherein: In response to receiving the persistent LBT failure indication, the second wireless communication terminal suspends the side link continuous discontinuous transmission DTX counter, the radio resource control RRC reconfiguration related timer, the RLC SDU for retransmission, or RETX_COUNT for the link associated with the first side link resource set.

24. The wireless communication method according to claim 23, wherein: The suspension of the sidelink continuous DTX counter, the RRC reconfiguration related timer, the RLC SDU for retransmission, or the RETX_COUNT is cancelled in response to at least one of the following: The second wireless communication terminal receives sidelink data or signaling from a user equipment in the first sidelink resource set; The second wireless communication terminal receives sidelink data or signaling from the first wireless communication terminal; The second wireless communication terminal determines that the first set of side link resources has become available; The second wireless communication terminal receives a persistent LBT failure recovery indication; or The second wireless communication terminal determines to cancel the suspension of the sidelink continuous DTX counter, the RRC reconfiguration related timer, the RLC SDU for retransmission, or the RETX_COUNT.

25. A wireless communication terminal, comprising: Communication unit; and A processor, wherein the processor is configured to execute the wireless communication method according to any one of claims 1 to 18.

26. A wireless communication terminal, comprising: Communication unit; and A processor, wherein the processor is configured to execute the wireless communication method according to any one of claims 19 to 24.

27. A computer program product comprising computer-readable program medium code stored thereon, which, when executed by a processor, causes the processor to implement the wireless communication method according to any one of claims 1 to 24.

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