User equipment and method for resource allocation and channel access in sidelink communication

Abstract

A method for resource allocation and channel access in sidelink communications by a user equipment (UE) includes identifying, by the UE, one or more candidate reserved resources, where the UE is configured to share its own channel occupancy time (COT) with the one or more candidate reserved resources, or the UE is configured to utilize a shared COT from the one or more candidate reserved resources.

Description

Technical Field

[0001] The present disclosure relates to the field of communication systems, and more specifically, to a method for resource allocation and channel access in user equipment (UE) and sidelink (SL) communications, which can provide good communication performance and / or high reliability. Background Art

[0002] In the development of radio wireless transmission and reception directly between two devices, which is generally referred to as device-to-device (D2D) communication, D2D communication was first developed by the 3rd generation partnership project (3GPP) and introduced in Release 12 (formally defined as sidelink communication) and improved in Release 13 for public safety emergency purposes such as mission-critical communications to mainly support low data rates and voice-type connections. In 3GPP Releases 14, 15, and 16, sidelink technology was developed to additionally support vehicle-to-everything (V2X) communications as part of the global development of intelligent transportation systems (ITS) to improve road safety and advanced / autonomous driving use cases. To further expand the support of sidelink technology to a wider range of applications and devices with limited power / battery, the technology was further enhanced in Release 17 in the areas of power saving and transceiver link reliability. For Release 18, 3GPP is currently looking to evolve wireless technology and expand its services into unlicensed spectrum to allow for greater available bandwidth, faster data rates, and easier market adoption of D2D communications using sidelinks without requiring any mobile cellular operator to be involved in allocating and configuring a portion of their large amounts of valuable radio spectrum for data services that do not run over their mobile networks.

[0003] Therefore, there is a need for a user equipment (UE) and a method for resource allocation and channel access in sidelink communication, which can: solve the problems in the prior art; reduce the overall burden of performing type 1 listen-before-talk (LBT) channel access procedures by one or more UEs; reduce blocking problems between UEs; provide less reselection of resources; provide faster / earlier transmission of data packets with less latency; provide reduced possibility of transmission conflicts; provide higher reliability of data packet transmission; provide less traffic congestion and more resources available to others; provide good communication performance; and / or provide high reliability. Summary of the invention

[0004] In a first aspect of the present disclosure, a user equipment (UE) includes an identifier configured to identify one or more candidate reserved resources, wherein the UE is configured to share its own channel occupancy time (COT) with the one or more candidate reserved resources, or the UE is configured to utilize the shared COT from the one or more candidate reserved resources.

[0005] In a second aspect of the present disclosure, a method for performing resource allocation and channel access by a user equipment (UE) in sidelink communication includes: identifying one or more candidate reserved resources by the UE, wherein the UE is configured to share its own channel occupancy time (COT) with the one or more candidate reserved resources, or the UE is configured to utilize a shared COT from the one or more candidate reserved resources.

[0006] In a third aspect of the present disclosure, a user equipment (UE) includes a memory, a transceiver, and a processor, wherein the processor is coupled to the memory and the transceiver. The UE is configured to execute the above method.

[0007] In a fourth aspect of the present disclosure, a non-transitory machine-readable storage medium has instructions stored thereon, which, when executed by a computer, cause the computer to perform the above method.

[0008] In a fifth aspect of the present disclosure, a chip includes a processor configured to call and run a computer program stored in a memory so that a device equipped with the chip executes the above method.

[0009] In a sixth aspect of the present disclosure, a computer-readable storage medium is provided, in which a computer program is stored, so that a computer executes the above method.

[0010] In a seventh aspect of the present disclosure, a computer program product includes a computer program, and the computer program enables a computer to execute the above method.

[0011] In an eighth aspect of the present disclosure, a computer program causes a computer to execute the above method. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the various embodiments or related technologies of the present disclosure, the following briefly introduces the drawings to be described in the embodiments. Obviously, the drawings are only some embodiments of the present disclosure, and ordinary technicians in this field can obtain other drawings based on these drawings without paying any price.

[0013] Figure 1 is a block diagram of a user equipment (UE) communicating in a communication network system according to an embodiment of the present disclosure.

[0014] Figure 2 is a schematic diagram showing a user plane protocol stack according to an embodiment of the present disclosure.

[0015] Figure 3 is a schematic diagram showing a control plane protocol stack according to an embodiment of the present disclosure.

[0016] Figure 4 The present invention is a flowchart showing a method for performing resource allocation and channel access by a UE in sidelink communication according to an embodiment of the present disclosure.

[0017] Figure 5 2 is a schematic diagram showing the side link (SL) resource selection for cooperative / supplementary channel access just before the existing reserved resources exemplarily proposed according to an embodiment of the present disclosure.

[0018] Figure 6 It is a schematic diagram showing the SL resource selection for cooperative / auxiliary channel access after the existing reserved resources exemplarily proposed according to an embodiment of the present disclosure.

[0019] Figure 7 is a block diagram of a UE for wireless communication according to an embodiment of the present disclosure.

[0020] Figure 8 is a block diagram of a system for wireless communication according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0021] The technical content, structural features, objectives and effects of the embodiments of the present disclosure are described in detail below in conjunction with the accompanying drawings. Specifically, the terms in the embodiments of the present disclosure are only for the purpose of describing specific embodiments, and are not intended to limit the present disclosure.

[0022] Shared / Unlicensed Spectrum

[0023] Traditionally, Wi-Fi wireless technology and Bluetooth wireless technology typically use shared (also called unlicensed or license-free) radio spectrum in the 2.4 gigahertz (GHz), 5 GHz, and 6 GHz bands for short-range communications (from a few meters to tens of meters). It is often claimed that the unlicensed spectrum band carries more traffic than any other radio frequency band because anyone can use the spectrum freely / free as long as the communication equipment complies with specific technical regulations set for each region. In addition to Wi-Fi and Bluetooth, other radio access technologies (RATs) such as licensed-assisted access (LAA) based on 4G-Long Term Evolution (4G-LTE) according to 3GPP and new radio unlicensed (NR-U) based on 5G-New Radio (5G-NR) mobile systems also operate in the same unlicensed bands. In order to enable devices with different RATs (Wi-Fi, Bluetooth, LAA, NR-U, and other possible RATs) to operate simultaneously in the same geographic area and coexist reasonably without causing serious interference and interruption to each other's transmissions, clear channel access (CCA) protocols such as listen before talk (LBT) adopted in LAA and NR-U and carrier sense multiple access / collision avoidance (CSMA / CA) used in Wi-Fi and Bluetooth are performed before any wireless transmission is performed to ensure that another radio wave is not transmitted on the same channel when another radio wave is already being transmitted.

[0024] For sidelink wireless technologies, in order to operate and coexist with existing RATs that are already operating in unlicensed frequency bands, LBT-based schemes can be adopted to ensure that there is no ongoing activity on the radio channel before attempting to access the channel for transmission. For example, when a sidelink user equipment (UE) successfully performs a type 1 LBT, the UE has the right to access and occupy the unlicensed channel for the duration of the channel occupation time (COT). This is called COT initiation. However, during the obtained COT, if the COT initiating sidelink UE or the COT responding sidelink UE does not perform wireless transmission for an idle time period exceeding a predetermined length (e.g., 16 microseconds (μs) or 25μs), devices of another RAT may still access the channel. Therefore, access to the channel may be lost until another successful LBT is performed. A potential solution to the problem of losing access to the channel may be back-to-back (B2B) transmission.

[0025] B2B transmission / multi-consecutive slots transmission (MCSt)

[0026] The main purpose of B2B transmission (which may also be called "burst transmission" or "multiple consecutive time slot transmission") is to enable the sidelink (SL) communication UE to continuously occupy the unlicensed channel for a longer period of time (i.e., more than one time slot) to mitigate the risk of losing access to the unlicensed channel to a wireless transmission (Tx) device of another radio access technology (RAT). The B2B transmission may be particularly important and useful for the following SL Tx-UEs operating in the unlicensed wireless spectrum: the SL Tx-UE has a larger size of data transmission block (TB) or medium access control (MAC) packet data unit (PDU), requires multiple retransmissions, sidelink hybrid automatic repeat request (SL-HARQ) feedback is disabled, and / or has a short delay requirement (small packet delay budget (PDB)). When the unlicensed wireless channel is busy / congested (e.g., many devices are trying to access the channel for transmission at the same time), obtaining access to the channel may be difficult and take a long time due to the random backoff timers and priority classes in the LBT procedure. Therefore, when the UE finally has the opportunity / opportunity to obtain access to the wireless channel for a channel occupancy time (COT) length that may last for several milliseconds (e.g., 2 milliseconds (ms), 4 ms, 6 ms, or 10 ms), the goal is to maintain channel access for as long as possible (e.g., all or most of the COT length), thereby sending as much data as possible by continuously transmitting in the unlicensed channel so that wireless devices of other RATs do not have the opportunity to access the channel.

[0027] Unauthorized channel access and occupation

[0028] As previously described, the UE may perform a Type 1 LBT procedure before making any SL transmissions to first acquire access to the unlicensed channel and initiate a COT. In addition, B2B transmissions may be used to avoid larger transmission intervals to maintain the COT and access to the channel. In addition to Type 1 LBT, the UE may also use Type 2 LBT during a COT or shared COT (as required by unlicensed spectrum regulations for intervals of 25 μs or less). For example, in Type 2A LBT, a COT initiating UE is allowed to resume its transmission and / or a COT sharing UE is allowed to start its transmission within the COT if the unlicensed channel is sensed to be idle for 25 μs or longer. In Type 2B LBT, the allowed transmission interval is 16 μs, and Type 2C LBT (for which the UE does not need to perform channel sensing) is used for intervals less than 16 μs.

[0029] In NR-U system and LAA system, due to the propagation delay between gNB / gNB to UE when sending scheduling control information, the UE switching from receive mode (RX) to transmit mode (TX), and the data information encoding and modulation for actual uplink (UL) transmission, there will inevitably / unavoidably be transmission gaps before the UE occupies the unlicensed channel. Sometimes, these gaps may be greater than 25μs, and the cyclic prefix extension may be transmitted first in the UL to avoid the unlicensed channel being taken over by other devices operating in the same spectrum band due to excessive channel idle time. The duration of this cyclic prefix extension (CPE) transmission in the UL is determined by the base station (gNB / eNB) to avoid any access blocking / denial issues between different UEs, and the duration will be indicated to each scheduled UE, and the UE only needs to follow the indication and perform UL transmission accordingly.

[0030] In SL communications, especially in resource allocation (RA) mode 2, the UE will determine and select all transmission resources on its own without the intervention, assistance and coordination of any base station to avoid transmission conflicts. In addition, the SL system enables frequency domain multiplexing (FDM) of transmissions from multiple UEs in the same time slot, thereby maximizing the efficiency of radio resource utilization while also reducing communication latency. However, since there is no control and assistance from the base station when the SL UE accesses one or more unlicensed channels, even in RA mode 1 scheduled by the gNB, the UE may attempt to access the channel at different times and using different LBT channel access procedures with different channel idle period requirements. In this type of operating scenario, it is not possible to coordinate in advance between the UEs transmitting in the same time slot to avoid access blocking / rejection to the unlicensed channels.

[0031] Inter-UE blocking during channel access procedure

[0032] As previously described, before being able to transmit any SL signal or channel within the initiated COT duration, the UE may first perform Type 1 LBT to obtain access to the unlicensed channel. More specifically, according to the existing Type 1 LBT channel access procedure used in NR-U, the length of time that the UE performs "monitoring" / "sensing" on the channel depends on the access priority category of the channel / signal to be transmitted. When the access priority category is high (for example, for emergency data packets with short latency requirements), in the most ideal case with the minimum allowed contention window size, the length of time required for LBT monitoring / sensing can be as short as one orthogonal frequency division multiplexing (OFDM) symbol (one SL transmission slot has 14 OFDM symbols). When the access priority category is low, the LBT monitoring / sensing time length may be as long as hundreds of OFDM symbols (which may require many SL transmission slots to complete). If the unlicensed channel is detected to be busy during the LBT procedure, the access counter stops until the channel is idle again. The problem that this essentially exists is inter-UE blocking between SL sending UEs. That is, if a UE attempts to access an unlicensed channel by performing Type 1 LBT while other UEs are already transmitting on the channel, then in this case, the UE will be blocked by the other UEs and may have difficulty completing the channel access procedure and obtaining access to the channel. This phenomenon is generally referred to as inter-UE blocking in the channel access procedure.

[0033] Mode 2 resource allocation mechanism in the sidelink

[0034] In the existing resource allocation mechanism design for SL communication, the mode 2 resource selection method relies on the SL sending UE to perform autonomous selection of resources from the SL resource pool for its own data message transmission. In this method, the selection of transmission resources is not random, but based on a listening and reservation strategy to avoid conflicts with other SL sending UEs operating in the same resource pool. In this resource selection strategy, the sending UE listens to the channel within the listening window (which is different from LBT channel listening) to detect and decode SL resource reservation information from other sending UEs. Based on the received resource reservation information, the UE excludes these reserved resources from the selection to avoid TX conflicts. Similarly, when transmitting data and control messages, the UE also sends / broadcasts its own resource reservation information in the resource pool so that other UEs can avoid selecting the same or overlapping resources. In the existing resource selection and reservation signaling design, the time interval between two consecutive reserved resources can be up to 31 time slots apart. Since there is no guarantee that resources are selected continuously in time, using this type of resource selection method is not ideal for MCSt.

[0035] In some embodiments, for the currently proposed method of resource allocation and channel access for sidelink communication in an unlicensed channel, the sending UE selects SL radio resources in a manner that assists or cooperates with another UE, thereby reducing the overall burden of performing type 1 LBT channel access procedures by two UEs and the above-mentioned blocking problem between UEs. Other benefits of using the proposed method of resource selection and channel access for SL communication in an unlicensed spectrum include:

[0036] Reducing SL transmission losses caused by inter-UE congestion means less resource reselection and faster / earlier delivery of packets with less latency.

[0037] Reduced resource reselection means fewer SL transmissions without any prior resource reservation. Therefore, the reduced possibility of transmission collisions can lead to higher reliability of packet delivery.

[0038] A higher probability of successful packet delivery also results in a lower number of SL transmissions in the unlicensed channel, which means less traffic congestion and more available resources for others.

[0039] Figure 1It is shown that, in some embodiments, one or more user equipments (UE) 10 (e.g., a first UE) and one or more user equipments (UE) 20 (e.g., a second UE) communicating in a communication network system 30 according to an embodiment of the present disclosure are provided. The communication network system 30 includes one or more UEs 10 and one or more UEs 20. The UE 10 may include a memory 12, a transceiver 13, and a processor 11 coupled to the memory 12 and the transceiver 13. The UE 20 may include a memory 22, a transceiver 23, and a processor 21 coupled to the memory 22 and the transceiver 23. The processor 11 or 21 may be configured to implement the proposed functions, processes, and / or methods described in this specification. A layer of a radio interface protocol may be implemented in the processor 11 or 21. The memory 12 or 22 is operably coupled to the processor 11 or 21 and stores various information to operate the processor 11 or 21. The transceiver 13 or 23 is operably coupled to the processor 11 or 21 and sends and / or receives a radio signal.

[0040] The processor 11 or 21 may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits and / or data processing devices. The memory 12 or 22 may include a read-only memory (ROM), a random access memory (RAM), a flash memory, a memory card, a storage medium and / or other storage devices. The transceiver 13 or 23 may include a baseband circuit for processing radio frequency signals. When the various embodiments are implemented in software, the techniques described herein may be implemented using modules (e.g., programs, functions, etc.) that perform the functions described herein. These modules may be stored in the memory 12 or 22 and executed by the processor 11 or 21. The memory 12 or 22 may be implemented within the processor 11 or 21, or may be implemented outside the processor 11 or 21. When the memory 12 or 22 is implemented outside the processor 11 or 21, the memory 12 or 22 may be communicatively coupled to the processor 11 or 21 in various ways known in the art.

[0041] According to the sidelink technology developed under the 3rd Generation Partnership Project (3GPP) long term evolution (LTE) and new radio (NR) version 17, version 18 and higher, the communication between multiple UEs involves vehicle-to-everything (V2X) communication, which V2X communication includes vehicle-to-vehicle (V2V), vehicle-to-pedestrian (V2P) and vehicle-to-infrastructure / network (V2I / N). Multiple UEs communicate directly with each other through a sidelink interface (e.g., a PC5 interface). Some embodiments of the present disclosure relate to sidelink communication technology in 3GPP NR version 17 and higher, for example, a sidelink communication technology that provides cellular-vehicle to everything (C-V2X) communication.

[0042] In some embodiments, UE 10 may be a sidelink packet transport block (TB) transmitting UE (Tx-UE). UE 20 may be a sidelink packet TB receiving UE (Rx-UE) or a peer UE. A sidelink packet TB Rx-UE may be configured to send ACK / NACK feedback to a packet TB Tx-UE. A peer UE 20 is another UE communicating with Tx-UE 10 in the same SL unicast session or multicast session.

[0043] Figure 2 An example user plane protocol stack according to an embodiment of the disclosure is shown. Figure 2It is shown that, in some embodiments, in the user plane protocol stack, the service data adaptation protocol (SDAP) sublayer, the packet data convergence protocol (PDCP) sublayer, the radio link control (RLC) sublayer and the medium access control (MAC) sublayer and the physical (PHY) layer (also referred to as the first layer or layer 1 (L1) layer) can be terminated at the UE 10 and the base station 40 (e.g., gNB) on the network side. In an example, the PHY layer provides transmission services to higher layers (e.g., MAC, RRC, etc.). In one example, the services and functions of the MAC sublayer may include: mapping between logical channels and transport channels; multiplexing MAC service data units (SDUs) belonging to one or different logical channels into / demultiplexing MAC SDUs belonging to one or different logical channels from a transport block (TB), which are transmitted to / from the PHY layer; scheduling information reporting; error correction through hybrid automatic repeat request (HARQ) (for example, in the case of carrier aggregation (CA), one HARQ entity per carrier); priority processing between multiple UEs through dynamic scheduling; priority processing between multiple logical channels of a UE through logical channel prioritization; and / or padding. The MAC entity may support one or more parameter sets (numerology) and / or transmission timing. In one example, mapping restrictions in logical channel prioritization may control the parameter sets and / or transmission timing that can be used by logical channels. In one example, the RLC sublayer can support transparent mode (TM), unacknowledged mode (UM) and acknowledged mode (AM) transmission modes. RLC configuration can be for each logical channel, independent of parameter set and / or transmission time interval (TTI) duration. In one example, automatic repeat request (ARQ) can operate on any parameter set and / or TTI duration configured for the logical channel.In one example, the services and functions of the PDCP layer of the user plane may include sequence numbering, header compression and decompression, user data transmission, reordering and duplicate detection, PDCP PDU routing (e.g., in the case of split bearer), retransmission of PDCP SDU, encryption, decryption and integrity protection, PDCP SDU discard, PDCP reconstruction and data recovery of RLC AM, and / or duplication of PDCP PDU. In one example, the services and functions of SDAP may include mapping between QoS flows and data radio bearers. In one example, the services and functions of SDAP may include mapping quality of service indicators (QFI) in downlink (DL) data packets and uplink (UL) data packets. In one example, the protocol entity of SDAP may be configured for a separate PDU session.

[0044] Figure 3 An example control plane protocol stack according to an embodiment of the present disclosure is shown. Figure 2It is shown that in some embodiments, in the control plane protocol stack, the PDCP sublayer, the RLC sublayer, the MAC sublayer, and the PHY layer can be terminated in the UE 10 and the base station 40 (e.g., gNB) on the network side, and perform the above services and functions. In one example, RRC is used to control radio resources between the UE and the base station (e.g., gNB). In one example, RRC can be terminated in the UE and the gNB on the network side. In one example, the services and functions of RRC may include: broadcasting of system information related to the access stratum (AS) and non-access stratum (NAS); paging initiated by the 5G core network (5GC) or the radio access network (RAN); establishment, maintenance and release of the RRC connection between the UE and the RAN; security functions (including key management), establishment, configuration, maintenance and release of signaling radio bearers (SRB) and data radio bearers (DRB); mobility functions; QoS management functions; UE measurement reporting and reporting control; detection and recovery of radio link failures; and / or NAS message transmission from the UE to the non-access stratum (NAS) / from the NAS to the UE. In one example, the NAS control protocol may terminate at the access and mobility management function (AMF) on the UE and network sides, and may perform functions such as authentication, mobility management for 3GPP access and non-3GPP access between the UE and the AMF, and session management for 3GPP access and non-3GPP access between the UE and the session management function (SMF).

[0045] When a certain specific application is executed in the UE and the specific application requires a data communication service, the application layer responsible for executing the specific application provides the NAS layer with application-related information, that is, application grouping / category / priority information / ID. In this case, the application-related information can be pre-configured / defined in the UE. (Alternatively, the application-related information is received from the network to be provided from the AS (RRC) layer to the application layer, and when the application layer starts the data communication service, the application layer requests the AS (RRC) layer that receives the information to provide the information.)

[0046] In some embodiments, the processor 11 is configured to identify one or more candidate reserved resources, wherein the processor 11 is configured to share its own channel occupation time (COT) with the one or more candidate reserved resources, or the processor 11 is configured to utilize the shared COT from the one or more candidate reserved resources. This can: solve the problems in the prior art; reduce the overall burden of performing type 1 listen-before-talk (LBT) channel access procedures by one or more UEs; reduce blocking problems between UEs; provide less reselection of resources; provide faster / earlier transmission of data packets with less latency; provide reduced possibility of transmission conflicts; provide higher reliability of data packet transmission; provide less traffic congestion and more resources available to others; provide good communication performance; and / or provide high reliability.

[0047] Figure 4 A method 410 for performing resource allocation and channel access by a UE in sidelink communication according to an embodiment of the present disclosure is shown. In some embodiments, the method 410 includes: block 412, identifying one or more candidate reserved resources by the UE, wherein the UE is configured to share its own channel occupation time (COT) with the one or more candidate reserved resources, or the UE is configured to utilize the shared COT from the one or more candidate reserved resources. This can: solve the problems in the prior art; reduce the overall burden of performing type 1 listen-before-talk (LBT) channel access procedures by one or more UEs; reduce blocking problems between UEs; provide less reselection of resources; provide faster / earlier transmission of data packets with less latency; provide reduced possibility of transmission conflicts; provide higher reliability of data packet transmission; provide less traffic congestion and more resources available to others; provide good communication performance; and / or provide high reliability.

[0048] In some embodiments, identification of the one or more candidate reserved resources by the UE is based on at least one of the following criteria: availability of candidate resources in consecutive time slots for multi-continuous time slot transmission (MCSt), which consecutive time slots have multiple time slots covering the UE processing time for decoding the COT shared information; resources reserved for unicast transmission, multicast transmission or broadcast transmission with a source identifier (identifier, ID) / target ID to which the UE belongs; a channel access priority class (CAPC) level of the UE's transmission that is equal to or lower than the CAPC level of the one or more candidate reserved resources; and a maximum / remaining COT sharing duration, which covers the UE processing time for decoding the COT shared information and the length of the one or more candidate reserved resources.

[0049] In some embodiments, the method further includes: performing resource selection by the UE before the one or more candidate reserved resources, wherein the UE shares its own COT for the one or more candidate reserved resources with another UE. In some embodiments, based on the source ID / target ID in the sidelink control information (SCI), the UE is configured to determine one or more candidate reserved resources that belong to the same unicast sidelink communication, multicast sidelink communication and / or broadcast sidelink communication as the UE. In some embodiments, the method further includes: selecting a candidate resource set for MCSt by the UE, wherein the number of time slots spanned by the candidate resource set is at least the same as the UE processing time of the COT shared information. In some embodiments, the candidate resource set is before one or more candidate reserved resources that belong to the same unicast sidelink communication, multicast sidelink communication or broadcast sidelink communication as the UE.

[0050] In some embodiments, identification of one or more candidate reserved resources by the UE is based on at least one of the following criteria: availability of at least one candidate resource at least one time length away from a first time slot of the one or more candidate reserved resources, wherein the time length covers the UE processing time for decoding COT sharing information from the one or more candidate reserved resources; a source ID / target ID of an expected transmission from the UE that is the same as the indicated ID of the one or more candidate reserved resources; a CAPC level of the UE's transmission that is equal to or higher than the CAPC level of the one or more candidate reserved resources; and a maximum / remaining COT sharing duration from the one or more candidate reserved resources, wherein the maximum / remaining COT sharing duration covers the UE processing time for decoding the COT sharing information and the length of the expected transmission from the UE.

[0051] In some embodiments, the method further includes: selecting, by the UE, the at least one candidate resource after the identified candidate reserved resource, wherein the UE is configured to utilize a shared COT from the identified candidate reserved resources. In some embodiments, based on the source ID / target ID in the SCI, the UE is configured to determine one or more candidate reserved resources that belong to the same unicast sidelink communication, multicast sidelink communication and / or broadcast sidelink communication as the UE. In some embodiments, at least one candidate resource after the first time slot of one or more identified candidate reserved resources belongs to the same unicast sidelink communication, multicast sidelink communication or broadcast sidelink communication as the UE. In some embodiments, the source ID / target ID of the sidelink transmission from the UE matches the same ID from the one or more identified candidate reserved resources, or is part of an additional ID in the COT sharing information of the UE from the one or more candidate reserved resources. In some embodiments, the method further includes: performing a type 2 channel access procedure by the UE by utilizing a shared COT from the one or more candidate reserved resources. In some embodiments, when the one or more candidate reserved resources are used for sidelink unicast transmission, the source ID / target ID of the expected transmission from the UE includes the source ID / target ID of the one or more candidate reserved resources. In some embodiments, when the one or more candidate reserved resources are used for sidelink multicast transmission or sidelink broadcast transmission, the source ID / target ID of the expected transmission from the UE is the same as the source ID / target ID of the one or more candidate reserved resources.

[0052] In the above embodiments, the term "configured" may refer to "pre-configured" and "configured by the network". The terms "predefined" or "predefined rules" in the present disclosure may be implemented by pre-storing corresponding codes, tables or other methods for indicating relevant information in a device (e.g., including UE and network equipment). The present disclosure does not limit the specific implementation methods. For example, "predefined" may refer to the content defined in the protocol. It should also be understood that in the present disclosure, "protocol" may refer to a standard protocol in the field of communications, such as LTE protocols, NR protocols, and related protocols used in future communication systems, and the present disclosure is not limited to this.

[0053] Example:

[0054] In some embodiments, for the new method for cooperative / assisted channel access into unlicensed / shared spectrum channels in the present disclosure, a radio resource is strategically selected by a sidelink (SL) transmitting user equipment (Tx-UE) based on one or more resources currently reserved in a resource pool. When appropriate, the transmission resource selection by the SL Tx-UE may take into account the processing time required to receive and decode the channel occupancy time (COT) sharing information.

[0055] As mentioned above, in order to obtain access to an unlicensed / shared channel, according to the regulations on frequency use in some parts of the world, the UE device must perform a listen-before-talk (LBT) channel access procedure as part of the idle channel access (CCA) protocol to ensure that the unlicensed / shared channel is not occupied by others, and then the UE device can start transmitting radio signals and data on the channel. According to the regulations, it is also specified that the UE device can use one of two channel access mechanisms to access the unlicensed / shared channel.

[0056] First, when the UE device does not have an effective channel occupancy time (COT) shared by another communication device / node (e.g., a base station node, a wireless access point, a UE, etc.), the UE device performs an LBT channel access procedure to listen to the channel for a random duration within a certain range, which is subject to the channel access priority class (CAPC) level of the signal / data to be transmitted. Generally, when the CAPC level is higher, the required LBT listening time is shorter to achieve faster access. Once the UE device successfully completes the LBT channel procedure (i.e., the channel is heard to be idle within a random time period within a certain range), the UE device will initiate a COT of a certain duration, and the UE device has the right to access the unlicensed / shared channel within the COT and transmit on it. The LBT channel access procedure is known in 3GPP for NR-U systems and is specified as a type 1 channel access procedure. As mentioned above, even when the channel is not busy, the LBT listening time in the type 1 channel access procedure can be as short as a few OFDM symbols or as long as hundreds of OFDM symbols. Alternatively, the UE device may share the COT initiated by itself with other devices so that other devices (ie, responding UEs) may also enjoy fast access to the channel, provided that the transmission of the responding UE needs to have an equal or higher CAPC level.

[0057] Secondly, when the UE device (responding UE) has received / obtained a valid COT shared by another communication node and capable of being used by the UE device to transmit radio signals / data on an unlicensed / shared channel, the UE device only performs a brief LBT channel access procedure of 25μs or 16μs (less than one OFDM symbol length) to ensure that the channel is idle before actual transmission. The LBT channel access procedure is known in 3GPP for NR-U systems and is specified as a type 2 channel access procedure. Therefore, it can be seen that the LBT listening duration required for the UE device to access an unlicensed / shared channel within a shared COT is significantly shorter than the case where the UE device needs to perform a complete type 1 LBT channel access procedure to initiate a COT for transmission. As previously mentioned, when the channel is always occupied by transmissions of other UE devices, it is usually more difficult for the UE device to use a type 1 LBT channel access procedure to obtain access to a congested unlicensed / shared channel due to congestion between UEs.

[0058] A possible solution to the above-mentioned blocking problem between UEs is that the UE device avoids selecting resources (e.g., in time slot k-1) just before the transmission of another UE (e.g., in time slot k) so that the transmission of the UE device does not block the other UE (e.g., in time slot k) from performing the type 1 LBT channel access procedure. In addition, based on the principle that a UE device cannot transmit in a time slot just before the transmission of another UE device, the UE device can also avoid selecting resources (e.g., in time slot k+1) just after the transmission of another UE (e.g., in time slot k), otherwise, the transmission of the other UE device will block the UE device (e.g., in time slot k) from performing the type 1 LBT channel access procedure. However, this resource selection method is not a good solution for the UE device because it unnecessarily limits the number of candidate resources from which the UE device can select its transmission resources. In addition, since nothing may be transmitted just before and after the time slot containing the SL transmission, this resource selection method may cause / result in a situation where one empty time slot appears in every two SL time slots. Furthermore, as mentioned previously, the time required to perform the Type 1 LBT channel access procedure may be much longer than one slot length. Simply avoiding the slots before and after SL transmissions in resource selection does not completely solve the inter-UE blocking problem. Therefore, a different solution is needed in which resource selection and channel access utilizing the COT sharing mechanism between SL transmissions should be performed in a collaborative / assisted manner.

[0059] The proposed resource selection mechanism based on existing resource reservation

[0060] In order to enable multiple SL sending UEs to cooperate and assist each other when accessing unlicensed / shared channels, the regulatory-permitted COT sharing function can be used to reduce / minimize the burden of UEs performing type 1 LBT channel access procedures (which are prone to blocking problems between UEs). By sharing the initiated COT with one or more expected and eligible target receiving UEs (which may also be referred to as responding UEs), according to the channel access mechanism for COT sharing described above, the target receiving UE / responding UE that shares the COT only needs to perform a brief LBT channel access procedure before its transmission. Since the last slot symbol of the SL time slot structure can easily accommodate the short LBT listening time, the blocking problem between UEs mentioned above does not exist. For example, when two UEs perform SL unicast communication, since the target and expectation of one UE's transmission is always another UE, it is expected that the two UEs share the COT to exchange data communications.

[0061] In this type of communication relationship, the two UEs are responding UEs to each other. In the SL multicast communication scenario, multiple SL UEs belong to the same communication group and share a common group ID / multicast ID. The initiated COT can also be shared by a group of UEs to facilitate the exchange of data communications, thereby minimizing blocking problems between UEs. The same COT sharing principle can also be applied to SL broadcast communications by using a public broadcast ID. It should be understood that COT sharing is used to minimize / reduce the burden of UEs performing type 1 LBT and associated blocking problems between UEs. In addition, the target receiving UE / responding UE in COT sharing can be determined by the unicast ID / multicast ID / broadcast ID.

[0062] In the existing SL mode 2 resource allocation procedure, the selection of resources is randomly implemented from the available candidate resource set. There is no specific mechanism / reason to explain why a candidate resource may be selected over other candidate resources. But before finally selecting the resources for transmission, the transmitting UE (Tx-UE) needs to first determine the candidate resource set within the resource selection window. As mentioned above, the SL mode 2 resource allocation procedure is based on the listening and reservation strategy, which avoids potential conflicts with other SL transmitting UEs by performing channel listening and excluding resources that have been reserved by other UEs from the candidate resource set. The remaining candidate resource set is then reported to the higher layer of the UE for final resource selection. During channel listening, which is different from the LBT listening used in the type 1 channel access procedure and the type 2 channel access procedure, the UE decodes the first-order sidelink control information (SCI-1) transmitted in the physical sidelink control channel (PSCCH) from all UEs within the listening window to identify all future reserved resources. When a reserved resource falls within the resource selection window of the Tx-UE, the resource is excluded from the candidate set. Although in the mode 2 listening procedure, the Tx-UE only needs to decode SCI-1 for resource selection purposes, the Tx-UE also needs to decode the second-order SCI (SCI-2) transmitted in the physical sidelink shared channel (PSSCH) (SCI-2 contains the source ID and the target ID) to determine whether the data content is intended for the Tx-UE.

[0063] For example, if the target ID received in SCI-2 identifies the multicast communication or unicast communication to which the Tx-UE belongs, the Tx-UE can proceed to further decode the data content transmitted in the PSSCH. From this, it can be seen that SL UEs operating in the same resource pool may need to decode at least SCI-1 and SCI-2 from all received SL transmissions to extract information about resource reservation and source ID / target ID. It should be understood that in mode 2RA, although only SCI-1 needs to be decoded for resource exclusion to avoid Tx conflicts, the UE still needs to decode SCI-2 in the PSSCH based on the source ID / target ID to determine whether the data information content is intended for the UE, and in SL-U, the target ID also determines whether the Tx-UE can utilize the shared COT. In addition, as part of channel access, the source ID / target ID (including unicast ID / multicast ID / broadcast ID) is also needed for COT sharing purposes in order to determine whether the Tx-UE is the intended target recipient UE / responding UE, and what type of channel access procedure needs to be used.

[0064] In the process of sharing COT with one or more other UEs, all necessary information associated with COT (e.g., target receiving UE, remaining COT duration, frequency resources, CAPC, etc.) can be provided by the COT initiating UE and transmitted via SCI and / or medium access control-control element (MAC CE). Some of this information (e.g., CAPC and frequency resources) can be carried in SCI-1, while other information (e.g., target receiving UE and remaining COT duration) can be carried in SCI-2 by utilizing some existing SCI parameter fields (e.g., source ID / target ID) to avoid duplication of information or MAC CE. Therefore, COT sharing information can be sent in both PSCCH and PSSCH and transmitted on multiple OFDM symbols within the SL time slot. Once the UE receives these SL channels in the early part of the SL time slot, the UE also needs some additional processing time to decode and extract the COT sharing information. If we assume that only SCI is used to transmit COT sharing information, the information will be transmitted in the first half of the SL time slot. If we further assume that the SL UE needs 1ms to decode the PSCCH and extract the SCI, the total UE processing time to receive and obtain the COT shared information is 1.5ms. In a SL communication system with a 15 kHz sub-carrier spacing (SCS), this can be translated into a UE processing time of 1.5 time slots.

[0065] This means that the earliest time slot of the shared COT that the UE can utilize starts from the 3rd time slot, because the first two time slots are used to transmit and decode the COT shared information. In a 30kHz SCS SL system, the earliest time slot of the shared COT that the UE can utilize starts from the 4th time slot. In a 60kHz SCS SL system, the earliest time slot of the shared COT that the UE can utilize starts from the 6th time slot. For the case where the MAC CE is also used to carry the COT shared information, the entire SL time slot may be required to transmit the COT content. Assume that now 1.5ms is required to decode the COT shared information from both the PSCCH and the PSSCH, in this case the total UE processing time is 2.5ms. In a 15kHz SCS SL system, the earliest time slot of the shared COT that the UE can utilize starts from the 4th time slot, because the first three time slots are used to transmit and decode the COT shared information. In a 30kHz SCS SL system, the earliest time slot of the shared COT that the UE can utilize starts from the 5th time slot. In a 60kHz SCS SL system, the earliest time slot of the shared COT that the UE can utilize starts from the 8th time slot.

[0066] In some embodiments, an innovative new method for performing resource selection based on existing / current resource reservation to obtain access to unlicensed / shared channels in a collaborative / assisted manner between SL transmitting UEs operating in the same resource pool is proposed, whereby the SL Tx-UE first identifies one or more candidate reserved resources (i.e., target receiving UE / responding UE) with which the SL Tx-UE can share its own COT or utilize a shared COT from it.

[0067] The identification of one or more candidate reserved resources with which the SL Tx-UE can share its COT is based on at least one of the following criteria: 1. Availability of candidate resources in consecutive time slots for MCSt, where these consecutive time slots have a sufficient number of time slots covering the minimum / required UE processing time length for decoding the COT shared information. 2. Resources reserved for unicast transmissions, multicast transmissions, or broadcast transmissions with the source ID / destination ID to which the SL TX-UE belongs. 3. The CAPC level of the SLTx-UE transmission is at least equal to or lower than the CAPC level of the candidate reserved resources. 4. The maximum COT sharing duration or the remaining COT sharing duration will cover the minimum / required UE processing duration for decoding the COT shared information and the length of one or more candidate reserved resources.

[0068] In some embodiments, if candidate reserved resources can be identified based on the above criteria, the SL Tx-UE may perform resource selection just before the candidate reserved resources, which are the target receiving UE / responding UE that shares the COT with the SL Tx-UE. It should be noted that during the SL Mode 2 listening procedure, based on the target ID received in the SCI, the Tx-UE will be able to determine which reserved resources belong to the same unicast SL communication, multicast SL communication and / or broadcast SL communication in which the Tx-UE is also participating / conducting. The Tx-UE may then select a set of candidate resources for the MCSt that spans at least the same number of time slots as the minimum / required time length for the UE to process the COT shared information, and may select one or more candidate resources just before the candidate reserved resources that belong to the same unicast SL communication, multicast SL communication or broadcast SL communication with the Tx-UE.

[0069] During SL transmission on the selected candidate resource set (e.g., using MCSt), the COT sharing information may indicate the same ID (source ID or target ID) from the candidate reserved resources as the target ID of the SL transmission, or as part of the ID of the additional ID in the COT sharing information. In this way, the UEs of the candidate reserved resources are able to utilize the COT shared by the Tx-UE and perform a brief type 2LBT channel access procedure to avoid blocking problems between UEs and obtain a higher possibility of accessing unlicensed / shared channels. In the case where the candidate reserved resources are used for SL unicast transmission, the COT sharing information may include the source ID of the candidate reserved resources. In the case where the candidate reserved resources are used for SL multicast transmission or SL broadcast transmission, the COT sharing information may include the target ID of the candidate reserved resources, which represents the multicast ID or broadcast ID to which the Tx-UE belongs.

[0070] Figure 5 The diagram 100 in FIG. 1 shows an exemplary illustration of the proposed SL resource selection for cooperative / supplementary channel access just before the reserved resource. In the diagram 100, it is assumed that the SL Tx-UE identifies a candidate reserved resource 101 that satisfies all the above selection criteria in the SL Mode 2 resource selection procedure. That is, there are resources available and suitable for selection by the SL Tx-UE in each of the 4 consecutive time slots 102 just before the candidate reserved resource, these consecutive time slots will cover the UE processing time (e.g., 1.5ms) 103 for decoding the COT shared information, the transmission type of the candidate reserved resource 101 is unicast, and the target ID points to the SL Tx-UE, the indicated CAPC level of the candidate reserved resource is equal to or higher than the CAPC level of the expected transmission of the SL-Tx UE, and the maximum length of the COT to be initiated by the SL Tx-UE will cover both the MCSt length 102 and the candidate reserved resource 101 (i.e., at least 5 time slots). Then, the SL Tx-UE selects an available resource set for MCSt 102 just before the candidate reserved resources 101 and performs a Type 1 LBT channel access procedure to initiate COT for MCSt 102 .

[0071] During the sidelink transmission in time slot k-4, the SL Tx-UE shares the COT of the SL Tx-UE by indicating the COT sharing information using SCI-1 104 and SCI-2 105 in the first half of time slot k-4, and the COT sharing information will include the target ID of the UE pointing to the candidate reserved resource 101 for unicast communication. For the UE that has reserved the candidate reserved resource 101, the UE (for example, for resource selection and data reception purposes) will continue to monitor / listen to the unlicensed / shared channel and even attempt to use the candidate reserved resource 101 in time slot k to perform a type 1 LBT channel access procedure for the transmission expected by the UE. During the monitoring / listening perception process, the UE of the candidate reserved resource will also receive and decode the COT sharing information provided by the SL Tx-UE in SCI-1 104 and SCI-2 105 of time slot k-4. Assuming that the UE of the candidate reserved resource obtains the COT sharing information 1.5 ms after receiving the middle part of time slot k-1, the UE of the candidate reserved resource 101 can discard the ongoing type 1 LBT channel access procedure and perform a brief type 2 LBT channel access procedure in the gap symbol at the end of time slot k-1 and before time slot k to obtain access to the channel. By selecting the transmission resource from SL-Tx just before the candidate reserved resource and sharing the COT of SL-Tx with the UE of the candidate reserved resource, the UE of the candidate reserved resource can only perform a brief type 2 LBT to obtain access to the unlicensed / shared channel for its intended transmission, thereby avoiding potential blocking problems between UEs.

[0072] The identification of one or more candidate reserved resources from which the SL Tx-UE is able to utilize a shared COT is based on at least one of the following criteria: A. The availability of at least one candidate resource that is at least a sufficient time length away from the first time slot of the one or more candidate reserved resources. The length of the time slot can be sufficient to cover the minimum / required UE processing time for decoding the COT sharing information from the one or more candidate reserved resources. B. The indicated ID (i.e., source ID or target ID) of the one or more candidate reserved resources is the same as the target ID of the expected transmission from the SL Tx-UE. This means that the expected transmission from the SL Tx-UE is a direct response to the transmission of the one or more candidate reserved resources for the shared COT. C. The CAPC level of the transmission of the SL Tx-UE is at least equal to or higher than the CAPC level of the one or more candidate reserved resources. D. The maximum COT sharing duration or the remaining COT sharing duration of the UE from the one or more candidate reserved resources will cover the minimum / required UE processing duration for decoding the COT sharing information and the length of the expected transmission from the SL Tx-UE.

[0073] In some embodiments, if at least one candidate reserved resource can be identified based on the above criteria, the SLTx-UE may select at least one candidate resource immediately after the identified candidate reserved resource, and the SL Tx-UE may utilize the shared COT from the candidate reserved resource. It should be noted that during the SL Mode 2 listening procedure, based on the target ID received in the SCI, the Tx-UE will be able to determine which reserved resources belong to the same unicast SL communication, multicast SL communication and / or broadcast SL communication in which the Tx-UE also participates / conducts. The SL Tx-UE may select at least one candidate resource for its own SL transmission after the 1st time slot of the one or more identified candidate reserved resources belonging to the same unicast / multicast / broadcast SL communication, and the time slot timing of the at least one candidate resource may take into account the minimum / required time length for the UE to process the received COT sharing information.

[0074] In some embodiments, during SL transmission from a SL Tx-UE using the selected at least one candidate resource, the target ID of the SL transmission from the SL-Tx UE may match the same ID (source ID or target ID) from the identified one or more candidate reserved resources, or be a part of an additional ID in the COT sharing information of the UE from the one or more candidate reserved resources. In this way, the SL Tx-UE is able to utilize the COT shared by the UEs from the one or more candidate reserved resources and perform a brief type 2 LBT channel access procedure to avoid blocking issues between UEs and obtain a higher probability of accessing unlicensed / shared channels. In the case where the one or more candidate reserved resources are used for SL unicast transmission, the target ID of the intended transmission from the SL Tx-UE may include the source ID of the one or more candidate reserved resources. In the case where the one or more candidate reserved resources are used for SL multicast transmission or SL broadcast transmission, the target ID of the intended transmission from the SL Tx-UE may be the same as the target ID of the one or more candidate reserved resources, which represents the groupcast ID or broadcast ID to which the SLTx-UE belongs.

[0075] Figure 6An exemplary illustration of the proposed SL resource selection for collaborative / supplementary channel access after reserving resources is shown in Figure 200. In Figure 200, it is assumed that the SL Tx-UE identifies a set 201 of 2 candidate reserved resources (in slot n and slot n+1) that meets all the above selection criteria in the SL Mode 2 resource selection procedure. That is, after the candidate reserved resource set in time slot n+4 202, there is a candidate resource available and suitable for selection by the SL Tx-UE, where the gap between the first time slot (time slot n) of the candidate reserved resource set and the candidate resource 202 is sufficient to cover the minimum / required UE processing time (e.g., 1.5ms) 203 for decoding the COT shared information, the transmission type of the candidate reserved resource 201 is multicast, and the target ID matches the target ID of the expected transmission from the SL Tx-UE, the indicated CAPC level of the candidate reserved resource set 201 is equal to or lower than the CAPC level of the expected transmission of the SL-Tx UE in time slot n+4 202, and the maximum length of the COT initiated by the UE of the candidate reserved resource set 201 will cover the minimum / required UE processing duration 203 for decoding the COT shared information and the length of the expected transmission from the SL Tx-UE in time slot n+4 202. In this case, the SL Tx-UE selects candidate resources 202 for its own transmission after the candidate reserved resource set 201 so as to utilize the shared COT of UEs from the candidate reserved resource set 201 transmitted in SCI-1 204 and SCI-2 205, and performs only type 2 LBT during the gap symbol just before the start of time slot n+4 202 (i.e., at the end of time slot n+3) to obtain access to the unlicensed / shared channel, thereby avoiding potential blocking problems between UEs.

[0076] For the case where the Tx-UE does not find any candidate reserved resources to share its own COT with or utilize the shared COT from it, and for the case where the Tx-UE does not attempt to find candidate reserved resources to share its own COT with or utilize the shared COT from it (i.e., the simple case of only selecting some empty resources for the MCSt), the Tx-UE can still select a resource set for the MCSt that covers at least the minimum processing time length required to decode the COT sharing information, so that another UE can select a candidate resource immediately after the MCSt and can still utilize the COT shared by the Tx-UE.

[0077] In summary, in order to increase the possibility of multiple SL sending UEs operating in the same resource pool to obtain access to unlicensed / shared channels, it is proposed that the SL sending UE strategically selects one or more side link resources at the transmission opportunity just before or after the existing / current reserved resources. By selecting one or more resources just before the existing / current reserved resources, the purpose is to allow the SL sending UE to perform type 1LBT to initiate COT and share its own COT in the following reserved resources for transmission, so that the UE of the reserved resources only needs to perform a brief type 2LBT procedure and avoid the type 1LBT channel access procedure that may be long and have uncertain results. In this way, for the reserved resources, the blocking effect / phenomenon between UEs that is usually associated with the UE performing the type 1LBT channel access procedure and often occurs is eliminated. However, the selection of resources just before the existing reserved resources can take into account the UE processing time for decoding the COT sharing information. By selecting one or more resources after the existing / current reserved resources, the purpose is to allow the SL sending UE to utilize the COT shared by the UEs of the reserved resources, so that the SL sending UE only needs to perform a brief type 2 LBT procedure and avoid the type 1 LBT channel access procedure which may be long and has uncertain results. In this way, for the SL sending UE, the blocking effect / phenomenon between UEs is eliminated. Similarly, the selection of resources by the SL sending UE after the existing / current reserved resources also needs to consider the processing time required to decode the COT shared information from the UEs of the reserved resources.

[0078] Figure 7 A UE 900 for wireless communication according to an embodiment of the present disclosure is shown. The UE 900 includes an identifier 901, which is configured to identify one or more candidate reserved resources, wherein the identifier 901 is configured to share its own channel occupation time (COT) with the one or more candidate reserved resources, or the identifier 901 is configured to utilize the shared COT from the one or more candidate reserved resources. The executor 901 is configured to execute the above method in the above embodiment. This can: solve the problems in the prior art; reduce the overall burden of performing type 1 listen-before-talk (LBT) channel access procedures by one or more UEs; reduce blocking problems between UEs; provide less reselection of resources; provide faster / earlier transmission of data packets with less delay; provide reduced possibility of transmission conflicts; provide higher reliability of data packet transmission; provide less traffic congestion and more resources available to others; provide good communication performance; and / or provide high reliability.

[0079] In some embodiments, the identifier 901 is configured to identify the one or more candidate reserved resources based on at least one of the following criteria: availability of candidate resources in consecutive time slots for multi-continuous time slot transmission (MCSt), wherein the consecutive time slots have a certain number of time slots covering the UE processing time for decoding the COT shared information; resources reserved for unicast transmission, multicast transmission or broadcast transmission with a source identifier ID / target ID to which the UE belongs; a channel access priority class (CAPC) level of transmission of a UE that is equal to or lower than the CAPC level of the one or more candidate reserved resources; and a maximum / remaining COT sharing duration that covers the UE processing time for decoding the COT shared information and the length of the one or more candidate reserved resources.

[0080] In some embodiments, the identifier 901 is configured to perform resource selection before the one or more candidate reserved resources, wherein the identifier 901 shares its own COT for the one or more candidate reserved resources with another UE. In some embodiments, based on the source ID / target ID in the sidelink control information (SCI), the identifier 901 is configured to determine one or more candidate reserved resources that belong to the same unicast sidelink communication, multicast sidelink communication and / or broadcast sidelink communication as the UE. In some embodiments, the identifier 901 is configured to select a candidate resource set for MCSt, wherein the number of time slots spanned by the candidate resource set is at least the same as the UE processing time of the COT shared information. In some embodiments, the candidate resource set is located before one or more candidate reserved resources that belong to the same unicast sidelink communication, multicast sidelink communication or broadcast sidelink communication as the UE.

[0081] In some embodiments, the identifier 901 is configured to identify the one or more candidate reserved resources based on at least one of the following criteria: the availability of at least one candidate resource that is at least one time length away from the first time slot of the one or more candidate reserved resources, wherein the time length covers the UE processing time for decoding the COT sharing information from the one or more candidate reserved resources; the source ID / target ID of the expected transmission from the UE that is the same as the indicated ID of the one or more candidate reserved resources; the CAPC level of the UE's transmission that is equal to or higher than the CAPC level of the one or more candidate reserved resources; and the maximum / remaining COT sharing duration from the one or more candidate reserved resources, which covers the UE processing time for decoding the COT sharing information and the length of the expected transmission from the UE.

[0082] In some embodiments, the identifier 901 is configured to select the at least one candidate resource after the identified candidate reserved resource, wherein the UE is configured to utilize the shared COT from the identified candidate reserved resources. In some embodiments, based on the source ID / target ID in the SCI, the identifier 901 is configured to determine the one or more candidate reserved resources that belong to the same unicast sidelink communication, multicast sidelink communication and / or broadcast sidelink communication as the UE. In some embodiments, the at least one candidate resource after the first time slot of the one or more identified candidate reserved resources belongs to the same unicast sidelink communication, multicast sidelink communication or broadcast sidelink communication as the UE. In some embodiments, the source ID / target ID of the sidelink transmission from the UE matches the same ID from the one or more identified candidate reserved resources, or is part of the ID of the additional ID in the COT sharing information of the UE from the one or more candidate reserved resources. In some embodiments, the identifier 901 is configured to perform a type 2 channel access procedure by utilizing the shared COT from the one or more candidate reserved resources. In some embodiments, when the one or more candidate reserved resources are used for sidelink unicast transmission, the source ID / target ID of the expected transmission from the UE includes the source ID / target ID of the one or more candidate reserved resources. In some embodiments, when the one or more candidate reserved resources are used for sidelink multicast transmission or sidelink broadcast transmission, the source ID / target ID of the expected transmission from the UE is the same as the source ID / target ID of the one or more candidate reserved resources.

[0083] The commercial benefits of some embodiments are as follows. 1. Solve the problems in the prior art. 2. Reduce the overall burden of performing type 1 LBT channel access procedures by one or more UEs. 3. Reduce blocking issues between UEs. 4. Provide fewer reselections of resources. 5. Provide lower latency to transmit data packets faster / earlier. 6. Provide reduced likelihood of transmission conflicts. 7. Provide higher reliability of data packet delivery. 8. Provide less traffic congestion and more resources available to others. 9. Provide good communication performance. 10. Provide high reliability. 11. Some embodiments of the present disclosure are used by: 5G-NR chipset suppliers, V2X communication system development suppliers, automobile manufacturers (including manufacturers of cars, trains, trucks, buses, bicycles, motorcycles and helmets, etc.), drones (unmanned aerial vehicles), smartphone manufacturers, smart watches, wireless earbuds, wireless headphones, communication devices, remote-controlled vehicles and robots for public safety, augmented reality (AR) / virtual reality (VR) device manufacturers (for example, for games, conferences / seminars, educational purposes), smart home appliances (including televisions (TVs), stereos, speakers, lights, doorbells, locks, cameras and conference headsets, etc.), smart factories and warehouse equipment (including Industrial Internet of Things (IIoT) devices, robots, robotic arms, and devices that are only between production machines). In some embodiments, the commercial benefits and commercial importance of the disclosed invention include: reducing the power consumption of wireless communication means extending the operating time of the device, and / or the better user experience and product satisfaction brought by the longer operating time of the device between battery charges and the next charge. Some embodiments of the present disclosure are combinations of "techniques / processes" that can be adopted in 3GPP specifications to produce terminal products. Some embodiments of the present disclosure relate to 3GPP NR Release 17, Release 18, Release 19 and above mobile cellular communication technology for providing direct device-to-device (D2D) wireless communication services.

[0084] Figure 8 is a block diagram of an example system 700 for wireless communications according to an embodiment of the present disclosure. The embodiments described herein may be implemented in a system using any suitably configured hardware and / or software. Figure 8 A system 700 is shown that includes at least a radio frequency (RF) circuit 710, a baseband circuit 720, an application circuit 730, a memory / storage device 740, a display 750, a camera 760, a sensor 770, and an input / output (I / O) interface 780 coupled to each other as shown.

[0085] The application circuit 730 may include circuits such as, but not limited to, one or more single-core processors or multi-core processors. The processor may include any combination of a general-purpose processor and a special-purpose processor, such as a graphics processor or an application processor. The processor may be coupled to a memory / storage device and configured to execute instructions stored in the memory / storage device to enable various applications and / or operating systems to run on the system.

[0086] The baseband circuit 720 may include circuits such as, but not limited to, one or more single-core processors or multi-core processors. The processor may include a baseband processor. The baseband circuit may handle various radio control functions that enable communication with one or more radio networks through RF circuits. The radio control functions may include, but are not limited to, signal modulation, encoding, decoding, radio frequency shifting, etc. In some embodiments, the baseband circuit may provide communications compatible with one or more radio technologies. For example, in some embodiments, the baseband circuit may support communications with an evolved universal terrestrial radio access network (EUTRAN) and / or other wireless metropolitan area networks (WMAN), wireless local area networks (WLAN), and wireless personal area networks (WPAN). An embodiment in which the baseband circuit is configured to support radio communications of more than one wireless protocol may be referred to as a multimode baseband circuit.

[0087] In various embodiments, baseband circuitry 720 may include circuitry for operating on signals that are not strictly considered to be in baseband frequencies. For example, in some embodiments, baseband circuitry may include circuitry for operating on signals having an intermediate frequency (which is between the baseband frequency and the radio frequency).

[0088] RF circuitry 710 may enable communication with a wireless network using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry may include switches, filters, amplifiers, etc. to facilitate communication with a wireless network.

[0089] In various embodiments, RF circuitry 710 may include circuitry for operating on signals that are not strictly considered to be in radio frequencies. For example, in some embodiments, RF circuitry may include circuitry for operating on signals having an intermediate frequency (which is between baseband frequency and radio frequency).

[0090] In various embodiments, the transmitter circuitry, control circuitry, or receiver circuitry discussed above with respect to user equipment, eNBs, or gNBs may be embodied in whole or in part in one or more of the RF circuitry, baseband circuitry, and / or application circuitry. As used herein, "circuitry" may refer to, be part of, or include an application specific integrated circuit (ASIC), electronic circuitry, processor (shared processor, dedicated processor, or processor group) and / or memory (shared memory, dedicated memory, or memory group) that executes one or more software or firmware programs; combinatorial logic circuitry; and / or other suitable hardware components that provide the described functionality. In some embodiments, electronic device circuitry may be implemented in one or more software or firmware modules, or the functionality associated with the circuitry may be implemented by one or more software or firmware modules.

[0091] In some embodiments, some or all components of the baseband circuit, application circuit, and / or memory / storage device may be implemented together on a system on a chip (SOC).

[0092] The memory / storage device 740 can be used, for example, to load and store data and / or instructions for the system. The memory / storage device of one embodiment can include any combination of suitable volatile memory (e.g., dynamic random access memory (DRAM)) and / or non-volatile memory (e.g., flash memory).

[0093] In various embodiments, I / O interface 780 may include one or more user interfaces designed to implement interaction between a user and the system, and / or a peripheral component interface designed to implement interaction between a peripheral component and the system. The user interface may include, but is not limited to, a physical keyboard or keypad, a touch pad, a speaker, a microphone, etc. The peripheral component interface may include, but is not limited to, a non-volatile memory port, a universal serial bus (USB) port, an audio jack, and a power interface.

[0094] In various embodiments, the sensor 770 may include one or more sensing devices for determining environmental conditions and / or location information associated with the system. In some embodiments, the sensor may include, but is not limited to, a gyroscope sensor, an accelerometer, a proximity sensor, an ambient light sensor, and a positioning unit. The positioning unit may also be part of the baseband circuit and / or the RF circuit, or interact with the baseband circuit and / or the RF circuit to communicate with components of a positioning network (e.g., a global positioning system (GPS) satellite).

[0095] In various embodiments, display 750 may include a display, such as a liquid crystal display and a touch screen display. In various embodiments, system 700 may be a mobile computing device, such as but not limited to a laptop computing device, a tablet computing device, a netbook, an ultrabook, a smart phone, AR / VR glasses, etc. In various embodiments, the system may have more components or fewer components and / or different architectures. Where appropriate, the methods described herein may be implemented as a computer program. The computer program may be stored on a storage medium (e.g., a non-transitory storage medium).

[0096] It should be understood by those skilled in the art that each of the units, algorithms, and steps described and disclosed in the embodiments of the present disclosure is implemented using electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are run on hardware or software depends on the application conditions and design requirements of the technical solution.

[0097] A person skilled in the art may use different methods to implement the functions for each specific application, and such implementation should not exceed the scope of the present disclosure. A person skilled in the art should understand that he / she can refer to the working process of the systems, devices and units in the above embodiments, because the working process of the above systems, devices and units is basically the same. For ease of description and brevity, these working processes will not be described in detail.

[0098] It should be understood that other methods may be used to implement the systems, devices, and methods disclosed in the embodiments of the present disclosure. The above embodiments are exemplary only. The division of each unit is based only on logical functions, and other divisions may exist during implementation. It is possible for multiple units or components to be combined or integrated into another system. It is also possible to omit or skip some features. On the other hand, the coupling, direct coupling, or communication coupling shown or discussed is operated indirectly or communicatively in an electrical, mechanical, or other type of form through some ports, devices, or units.

[0099] The units that are separate components for explanation are physically separate or not separate. The units used for display are physical units or not physical units, that is, located in one place or distributed on multiple network units. Some or all of the units are used according to the purpose of the embodiment. In addition, each functional unit in each functional unit of each embodiment of the embodiments can be integrated into a processing unit, can be physically independent, or can be integrated into a processing unit together with two or more units.

[0100] If the software functional unit is implemented as a product and used and sold as a product, the software functional unit can be stored in a readable storage medium in a computer. Based on this understanding, the technical solution proposed in the present disclosure can be implemented basically or partially in the form of a software product. Alternatively, a part of the technical solution that is beneficial to traditional technology can be implemented in the form of a software product. The software product in the computer is stored in a storage medium, and the software product includes a plurality of commands for a computing device (e.g., a personal computer, a server, or a network device) to run all or part of the steps disclosed in the embodiment of the present disclosure. The storage medium includes: a USB disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a floppy disk, or other types of media capable of storing program code.

[0101] While the present disclosure has been described in connection with what are considered to be the most practical and preferred embodiments, it is to be understood that the present disclosure is not limited to the disclosed embodiments but is intended to cover various arrangements made without departing from the scope of the broadest interpretation of the appended claims.

Claims

1. A method for performing resource allocation and channel access by a user equipment UE in sidelink communication, comprising: One or more candidate reserved resources are identified by the UE, wherein the UE is configured to share its own channel occupancy time COT with the one or more candidate reserved resources, or the UE is configured to utilize the shared COT from the one or more candidate reserved resources.

2. The method according to claim 1, wherein: The identifying, by the UE, of the one or more candidate reserved resources is based on at least one of the following criteria: availability of candidate resources in consecutive time slots for a multi-consecutive time slot transmission MCSt, wherein the consecutive time slots have a number of time slots covering the UE processing time for decoding the COT shared information; Resources reserved for unicast transmission, multicast transmission or broadcast transmission having a source identifier ID / destination ID to which the UE belongs; a CAPC level of transmission of the UE that is equal to or lower than a channel access priority class CAPC level of the one or more candidate reserved resources; and A maximum / remaining COT sharing duration covering the UE processing time for decoding the COT sharing information and the length of the one or more candidate reserved resources.

3. The method according to claim 1 or 2, further comprising: Resource selection is performed by the UE before the one or more candidate reserved resources, wherein the UE shares its COT for the one or more candidate reserved resources with another UE.

4. The method according to any one of claims 1 to 3, wherein: Based on the source ID / target ID in the sidelink control information SCI, the UE is configured to determine one or more candidate reserved resources belonging to the same unicast sidelink communication, multicast sidelink communication and / or broadcast sidelink communication as the UE.

5. The method according to any one of claims 1 to 4, further comprising: A candidate resource set for MCSt is selected by the UE, wherein the number of time slots spanned by the candidate resource set is at least the same as the UE processing time of COT sharing information.

6. The method according to claim 5, wherein: The candidate resource set precedes one or more candidate reserved resources belonging to the same unicast sidelink communication, multicast sidelink communication, or broadcast sidelink communication as the UE.

7. The method according to claim 1, wherein: The identifying, by the UE, of the one or more candidate reserved resources is based on at least one of the following criteria: availability of at least one candidate resource that is at least one time length away from a first time slot of the one or more candidate reserved resources, wherein the time length covers a UE processing time for decoding COT shared information from the one or more candidate reserved resources; a source ID / target ID of an expected transmission from the UE that is the same as the indicated ID of the one or more candidate reserved resources; a CAPC level of transmissions of the UE that is equal to or higher than a CAPC level of the one or more candidate reserved resources; and A maximum / remaining COT sharing duration from the one or more candidate reserved resources, the maximum / remaining COT sharing duration covering the UE processing time for decoding the COT sharing information and the length of the expected transmission from the UE.

8. The method according to claim 7, further comprising: The at least one candidate resource is selected by the UE after the identified candidate reserved resources, wherein the UE is configured to utilize the shared COT from the identified candidate reserved resources.

9. The method according to claim 7 or 8, wherein: Based on the source ID / target ID in the SCI, the UE is configured to determine one or more candidate reserved resources belonging to the same unicast sidelink communication, multicast sidelink communication and / or broadcast sidelink communication as the UE.

10. The method according to claim 8 or 9, wherein: At least one candidate resource after a first time slot of the one or more identified candidate reserved resources belongs to the same unicast sidelink communication, multicast sidelink communication or broadcast sidelink communication as the UE.

11. The method according to claim 10, wherein: The source ID / target ID of the sidelink transmission from the UE matches the same ID from the one or more identified candidate reserved resources, or is part of an additional ID in the COT shared information of the UE from the one or more candidate reserved resources.

12. The method according to claim 11, further comprising: A type 2 channel access procedure is performed by the UE by utilizing the shared COT from the one or more candidate reserved resources.

13. The method according to claim 11 or 12, wherein: When the one or more candidate reserved resources are for sidelink unicast transmission, the source ID / target ID of the expected transmission from the UE contains the source ID / target ID of the one or more candidate reserved resources.

14. The method according to claim 11 or 12, wherein: When the one or more candidate reserved resources are used for sidelink multicast transmission or sidelink broadcast transmission, the source ID / target ID of the expected transmission from the UE is the same as the source ID / target ID of the one or more candidate reserved resources.

15. A user equipment UE, comprising: An identifier, the identifier being configured to identify one or more candidate reserved resources, wherein the UE is configured to share its own channel occupancy time COT with the one or more candidate reserved resources, or the UE is configured to utilize the shared COT from the one or more candidate reserved resources.

16. A user equipment UE, comprising: Memory; Transceiver; as well as a processor coupled to the memory and the transceiver; The UE is configured to perform the method according to any one of claims 1 to 14. 17 . A non-transitory machine-readable storage medium having instructions stored thereon, wherein when the instructions are executed by a computer, the computer is caused to perform the method according to any one of claims 1 to 14.

18. A chip, comprising: A processor, wherein the processor is configured to call and run a computer program stored in a memory so as to enable a device equipped with the chip to perform a method according to any one of claims 1 to 14.

19. A computer-readable storage medium having a computer program stored therein, wherein: The computer program causes a computer to execute the method according to any one of claims 1 to 14.

20. A computer program product, the computer program product comprising a computer program, wherein: The computer program causes a computer to execute the method according to any one of claims 1 to 14.

21. A computer program, wherein The computer program causes a computer to execute the method according to any one of claims 1 to 14.

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