Terminal device and method for destination selection for sidelink transmission

Abstract

The embodiment of the invention relates to a terminal device and method for destination selection for sidelink transmission. A terminal device receives channel occupancy time (COT) sharing information via a transceiver. The terminal device determines whether there is at least one destination satisfying a COT requirement associated with the COT sharing information among one or more destinations to which the terminal device is to transmit data. The terminal device selects a destination for the sidelink transmission from the one or more destinations based on a result of the determination. In this manner, the reliability and efficiency of sidelink communications may be improved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present disclosure generally relate to the field of communications, and in particular, to a terminal device, a method and a non-transitory computer readable medium for destination selection for sidelink transmission. BACKGROUND

[0002] Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems can be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). To meet the growing demand for mobile broadband connectivity, new radio (NR) technologies have been developed to support more capable, high-speed, low-latency communication systems. NR systems can utilize a wide array of frequencies, from low-frequency bands below approximately 1 gigahertz (GHz) and mid-frequency bands from approximately 1 GHz to approximately 6 GHz, to high-frequency bands such as millimeter wave (mmWave) bands. NR systems are also designed to operate across different spectrum types, from licensed spectrum to unlicensed and shared spectrum. In NR unlicensed (NR-U), to coexist with other wireless technologies (e.g., Wi-Fi systems) on unlicensed bands, a listen-before-talk (LBT) procedure can be performed on scheduled or selected resources to occupy the channel before each transmission.

[0003] Sidelink (SL) transmissions can also operate on unlicensed bands. LBT techniques introduced in NR-U can be used to enable SL transmissions to coexist with other wireless systems on unlicensed bands. If a type-1 LBT procedure is successful, a sidelink device (UE) can access the channel and perform a transmission. In addition, the sidelink UE can occupy the channel for a duration of time referred to as channel occupancy time (COT). There is still a need to enhance SL transmissions on unlicensed bands (SL-U). SUMMARY

[0004] Generally, embodiments of the present disclosure provide a solution for destination selection for sidelink transmissions in unlicensed bands.

[0005] In a first aspect, a terminal device is provided. The terminal device includes a processor and a transceiver coupled to the processor. The processor is configured to receive, via the transceiver, channel occupancy time (COT) sharing information, determine, among one or more destinations to which the terminal device is to transmit data, whether there is at least one destination that satisfies a COT requirement associated with the COT sharing information, and select, based on a result of the determination, a destination for a sidelink transmission from the one or more destinations.

[0006] In a second aspect, a method performed by a terminal device is provided. The method comprises receiving channel occupancy time (COT) sharing information; determining, among one or more destinations to which the terminal device is to transmit data, whether there is at least one destination that satisfies a COT requirement associated with the COT sharing information; and selecting, based on a result of the determination, a destination for sidelink transmission from the one or more destinations.

[0007] In a third aspect, a non-transitory computer-readable medium is provided. The non-transitory computer-readable medium has program instructions stored thereon that, when executed by an apparatus, cause the apparatus to at least: receive channel occupancy time (COT) sharing information; determine, among one or more destinations to which the terminal device is to transmit data, whether there is at least one destination that satisfies a COT requirement associated with the COT sharing information; and select, based on a result of the determination, a destination for sidelink transmission from the one or more destinations.

[0008] It should be understood that the Summary section is not intended to identify key or essential features of embodiments of the disclosure or to limit the scope of the disclosure. Other features of the disclosure will be apparent from review of the description below in conjunction with the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0009] Some embodiments will now be described, by way of example, with reference to the accompanying drawings, in which:

[0010] Figure 1 A schematic diagram of a communication environment in which some embodiments of the disclosure are implemented is shown;

[0011] Figure 2 A flowchart of an example method for destination selection according to some embodiments of the disclosure is shown;

[0012] Figure 3 An example block diagram for destination selection according to some embodiments of the disclosure is shown; and

[0013] Figure 4 A simplified block diagram of an apparatus suitable for implementing some embodiments of the disclosure is shown.

[0014] In all the drawings, the same or similar reference numerals identify the same or similar elements. DETAILED DESCRIPTION

[0015] The principles of the disclosure will now be described with reference to some embodiments. It should be understood that the description of these embodiments is merely intended to be illustrative and help the skilled person understand and implement the disclosure, and does not mean any limitation on the scope of the disclosure. The disclosure described herein can be implemented in various ways other than those described below.

[0016] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0017] In this disclosure, references to “one embodiment,” “an example embodiment,” “an embodiment,” “some embodiments,” etc. indicate that the described embodiment(s) can include a particular feature, structure, or characteristic, but every embodiment can not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, where a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one of ordinary skill in the art to effect such feature, structure, or characteristic in connection with other

[0018] It should be understood that although the terms “first” and “second” etc. can be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could also be termed a second element, and, similarly, a second element could also be termed a first element without departing from the scope of the examples. As used herein, the term “and / or” includes any and all combinations of one or more of the associated terms.

[0019] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and / or “including,” when used herein, specify the presence of stated features, elements and / or components, but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof.

[0020] As used herein, the term “communication network” refers to a network that follows any suitable communication standard, such as 5G NR, Long-Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code-Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), Narrow Band-Internet of Things (NB-IoT), etc. Moreover, the communication between terminal devices and network devices in a communication network can be performed according to any suitable generation communication protocol, including but not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G) communication protocols, and / or any other protocols that are currently known or that will be developed in the future. Embodiments of the present disclosure can be applied to various communication systems. Due to the rapid development in communications, there will be future types of communication technologies and systems in which the present disclosure can be embodied. The scope of the present disclosure should not be understood as being limited only to the above-mentioned systems.

[0021] As used herein, the term “network device” generally refers to a node in a communication network via which terminal devices can access a communication network and receive services from. The network device can refer to a base station (BS) or an access point (AP), e.g., a NodeB (NB), a radio access network (RAN) node, an evolved NodeB (eNodeB or eNB), an NR NB (also referred to as gNB), a remote radio unit (RRU), a radio head (RH), an infrastructure equipment for V2X (vehicle-to-everything) communication, a transmission reception point (TRP), a reception point (RP), a remote radio head (RRH), a relay, an integrated access or backhaul (IAB) node, a low power node (such as a femto BS, a pico BS, etc.), depending on the terminology used and technology.

[0022] As used herein, the term "terminal device" generally refers to any terminal device capable of wireless communication. By way of example, and without limitation, a terminal device can also be referred to as a communication device, a user equipment (UE), an end user device, a subscriber station (SS), an unmanned aerial vehicle (UAV), a portable subscriber station, a mobile station (MS), or an access terminal (AT). A terminal device can include, but is not limited to, a mobile phone, a cellular phone, a smart phone, a voice over Internet Protocol (VoIP) phone, a wireless local loop phone, a tablet, a wearable terminal device, a personal digital assistant (PDA), a portable computer, a desktop computer, an image capture terminal device, such as a digital camera, a game terminal device, a music storage and playback appliance, a vehicle-mounted wireless terminal device, a wireless endpoint, a mobile station, an embedded notebook device (LEE), a laptop installed device (LME), a USB dongle, a smart device, a wireless customer premises equipment (CPE), an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, a medical device (e.g., a remote surgery device), an industrial device (e.g., a robot and / or other wireless devices operating in an industrial and / or automation processing chain context), a consumer electronic device, a device operating on a commercial and / or industrial wireless network, etc. In the following description, the terms "terminal device," "communication device," "terminal," "user equipment," and "UE" can be used interchangeably.

[0023] As used herein, the terms "resource," "transmission resource," "resource block," "physical resource block," "uplink resource," "downlink resource," or "sidelink resource" can refer to any resource, e.g., a time domain resource, a frequency domain resource, a spatial domain resource, a code domain resource, or any other resource enabling communication, used to perform communication between a terminal device and a network device or between terminal devices. In the following, resources in both frequency and time domain will be used as an example for transmission resources for describing some embodiments of the present disclosure. It should be noted that embodiments of the present disclosure equally apply to other resources in other domains.

[0024] To extend the usefulness of destination selection in sidelink on unlicensed bands for non- commercial use cases, one of the identified key requirements is to increase the data rate. SL-U can support to meet the requirement. In addition, with the support of unlicensed spectrum, destination selection in SL-U will be in a better position to be implemented in commercial devices, as the utilization of intelligent transportation systems (ITS) is limited to ITS safety related applications.

[0025] For the study of SL-U, one target is the channel access mechanism, which is as follows:

[0026] Before starting a sidelink transmission over a shared spectrum or an unlicensed spectrum, a sidelink UE can contend for channel access in the spectrum, e.g., via a CCA and / or an LBT procedure. If a type-1 LBT procedure is successful, the SL UE can occupy the channel for a COT. For example, a first UE can contend for a COT in an unlicensed band for sidelink communications by performing an LBT procedure. Upon winning the contention, the first UE can transmit sidelink data to a second UE via a physical sidelink shared channel (PSSCH) and / or transmit sidelink control information (SCI) to the second UE via a physical sidelink shared channel (PSSCH).

[0027] There are two resource allocation modes for transmission in SL-U, i.e., a dynamic scheduling mode and an autonomous selection mode. In the dynamic scheduling mode, a network device dynamically allocates transmission resources to a SL UE according to a data report of a buffer of the SL UE. In the autonomous selection mode, a SL UE randomly selects transmission resources from a resource pool broadcasted or pre-configured by a network device.

[0028] A SL UE can perform multiplexing and assembling of a medium access control packet data unit (MAC PDU) to be transmitted in the selected resources in a sidelink unlicensed band. Because each MAC PDU can only be transmitted to one destination, the SL UE can perform a logical channel prioritization (LCP) procedure during multiplexing and assembling in order to select target destinations and corresponding logical channel(s) to be multiplexed into the MAC PDU.

[0029] A conventional LCP procedure is defined according to 5.22.1.4.1.2 in TS 38.321, which is shown as follows:

[0030] It is proposed in the current 3GPP discussion that a COT initiated by a SL UE can be shared with other SL UEs for sidelink transmissions in an unlicensed band. To meet this provision, a sidelink transmission can be performed by a corresponding SL UE, which can be referred to as a responding UE, in a COT only when a receiver of the sidelink transmission is the initiating UE, i.e., the sidelink transmission is to be transmitted to the UE that initiated the COT.

[0031] Prior to the LCP procedure, the physical layer of the SL UE can indicate the available COT duration and corresponding COT sharing information to be used by the SL UE. Each COT duration can be used under the constraints of destination identifier (ID) and channel access priority level (CAPC) priority. For example, only transmissions to destinations with multiple destination IDs in the COT sharing information are allowed to use COT, and only logical channels whose CAPC priority is equal to or higher than the CAPC priority in the COT sharing information can be selected to use COT.

[0032] The following has been agreed upon in TS38.321 of the 3GPP RAN2#121 meeting:

[0033] However, the conditions under which a UE selects an LCP solution are not yet clear. For example, under what conditions should a UE perform a modified LCP procedure based on COT-shared information? Furthermore, the auxiliary information from the responding UE to the initiating UE needs further investigation for use in COT sharing.

[0034] Based on the foregoing discussion, embodiments of this disclosure provide a solution for destination selection for sidelink transmissions. In one aspect of the solution, a terminal device receives Channel Occupancy Time (COT) sharing information. The terminal device determines whether, among one or more destinations to which it intends to transmit data, there exists at least one destination that satisfies the COT requirements associated with the COT sharing information. Based on the determination, the terminal device selects a destination from the one or more destinations for sidelink transmission. With the proposed solution, the terminal device can determine whether to perform a modified LCP procedure or a traditional procedure based on the COT sharing information. Therefore, the reliability and efficiency of sidelink communication can be improved. The principles and implementation of embodiments of this disclosure will now be described with reference to the accompanying drawings. Example embodiments

[0035] Figure 1 A schematic diagram of a communication environment 100 in which some embodiments of this disclosure can be implemented is shown. For example... Figure 1 As shown, the communication environment 100 (also referred to as the communication network 100 or the communication system 100) includes network equipment 110, terminal equipment 120-1, terminal equipment 120-2, terminal equipment 120-3 and terminal equipment 120-4 (collectively referred to as terminal equipment 120).

[0036] Network device 110 manages cell 112 and serves terminal devices 120-1 and 120-2 within cell 112. Terminal devices 120-1 and 120-2 can communicate with network device 110 respectively to send data and / or control information. Specifically, as... Figure 1 As shown in the exemplary scenario, terminal device 120-1 can communicate with network device 110 via communication link 115-1, and terminal device 120-2 can communicate with network device 110 via communication channel 115-2. For transmissions from network device 110 to terminal device 120-1 or 120-2, communication link 115-1 or 115-2 can be referred to as a downlink; however, for transmissions from terminal device 120-1 or 120-2 to network device 110, communication link 115-1 or 115-2 can alternatively be referred to as an uplink.

[0037] In addition to communication links 115-1 and 115-2, terminal devices 120-1 and 120-2 can perform sidelink transmissions via sidelink 125-1 between them, which is also known as device-to-device (D2D) communication. For example, in Figure 1 In an exemplary scenario, terminal device 120-1 performs a sidelink transmission 130-1 to terminal device 120-2 via sidelink 125-1. In some embodiments, sidelink transmission 130-1 may be performed on an unlicensed frequency band, where various wireless devices share the same wireless spectrum based on different wireless technologies.

[0038] like Figure 1 As shown, terminal devices 120-3 and 120-4 can be outside the coverage area of ​​network device 110 (i.e., outside cell 112). For terminal devices 120-3 and 120-4, destination selection in the sidelink on the unlicensed frequency band may only exist. For example, terminal devices 120-1 and 120-3 can perform sidelink transmission via sidelink 125-2 between terminal devices 120-1 and 120-3. Terminal devices 120-2 and 120-4 can perform sidelink transmission via sidelink 125-3 between terminal devices 120-2 and 120-4. Terminal devices 120-3 and 120-4 can perform sidelink transmission via sidelink 125-4 between terminal devices 120-3 and 120-4. Although not inFigure 1 As illustrated in FIG. 1, sidelink transmissions can be performed between terminal devices 120-1 and 120-4 and between terminal devices 120-2 and 120-3 via respective sidelinks.

[0039] In some embodiments, network equipment 110 can not be present in communication environment 100. In other words, terminal devices 120-1, 120-2, 120-3, and 120-4, and possibly other terminal devices (not shown) can be outside the coverage of network equipment 110 (i.e., outside of cell 112). In this case, destination selection in sidelinks over unlicensed bands can only exist between terminal devices 120-1, 120-2, 120-3, and 120-4, and possibly other terminal devices (not shown) not in the coverage of network equipment 110. Figure 1

[0040] As used herein, the term “sidelink transmission” generally refers to any transmission performed from one terminal device to another terminal device. Sidelink transmissions can be used to transmit any data or control information associated with destination selection in sidelinks over unlicensed bands, e.g., sidelink data, sidelink control information, sidelink feedback information, etc. As used herein, the term “sidelink channel” can generally refer to any channel used for destination selection in sidelinks over unlicensed bands, e.g., physical sidelink shared channel (PSSCH), physical sidelink control channel (PSCCH), physical sidelink discovery channel (PSDCH), physical sidelink broadcast channel (PSBCH), physical sidelink feedback channel (PSFCH), and other existing or future sidelink channels.

[0041] Channel access in sidelinks can rely on so-called LBT procedures. For example, before performing sidelink transmission 130-1, terminal device 120-1 can first “sense” the communication channel to discover that the communication channel is not occupied by any communication before transmitting on the communication channel. If sidelink transmission 130-1 is to be performed in an unlicensed band, terminal device 120-1 can first perform destination selection in sidelinks over unlicensed bands for sidelink transmission 130-1, if sidelink resources are scheduled or selected for sidelink transmission 130-1, the LBT procedure can be performed on the scheduled or selected sidelink resources before sidelink transmission 130-1. In some embodiments, if a type 1 LBT procedure is successful, terminal device 120-1 can access the channel and perform sidelink transmission 130-1 on the scheduled or selected sidelink resources. Furthermore, terminal device 120-1 can occupy the channel for a COT.

[0042] ​In some embodiments, the sidelink transmission 130-1 can not need the entire duration of the COT. Thus, the terminal device 120-1 can allow another sidelink UE (e.g., the terminal devices 120-1, 120-2, 120-3, and 120-4, and possibly other terminal devices (not shown)) to opportunistically join the COT and utilize any unoccupied resources. To facilitate COT sharing, the terminal device 120-1 can include COT sharing information in the SCI. For example, the COT sharing information can include information associated with available or unoccupied resources, a destination ID, and a priority (e.g., a CAPC priority) for obtaining the COT.

[0043] In some embodiments, only a destination with a destination ID in the COT sharing information can be allowed to use the COT, and only a logical channel with a CAPC priority equal to or higher than the CAPC priority in the COT sharing information can be selected to utilize the shared COT. For example, if a respective terminal device obtaining the COT sharing information is to perform a sidelink transmission, and a destination ID of the sidelink transmission is included in the COT sharing information, the sidelink transmission can be performed in the COT initiated by the terminal device 120-1. In this case, the terminal device 120-1 initiating the COT can be referred to as an “initiating UE,” and the terminal device performing the transmission using the shared COT can be referred to as a “responding UE.”

[0044] Although the network device 110 and the terminal devices 120-1, 120-2, 120-3, and 120-4 are described in the communication environment 100 of Figure 1 , embodiments of the present disclosure can equally apply to any other suitable communication devices that communicate with each other. That is, embodiments of the present disclosure are not limited to Figure 1 the exemplary scenarios of Figure 1 . In this regard, it should be noted that although the network device 11 is schematically described as a base station and the terminal devices 120 are schematically described as mobile phones in

[0045] In the case where the terminal devices 120-1, 120-2, 120-3, and 120-4 are vehicular terminal devices, the communication related thereto can be referred to as V2X communication. More generally, although not described in Figure 1As shown, however, V2X communication associated with terminal device 120 may include communication channels between terminal device 120 and any other communication devices, including but not limited to infrastructure equipment, another vehicle-mounted terminal device, pedestrian equipment, roadside units, etc. Furthermore, although not shown, as... Figure 1 All communication links shown can be transmitted via one or more relays.

[0046] It should be understood that, such as Figure 1 The specific numbers of various communication devices, communication links, other elements, and cell 112 shown are for illustrative purposes only and do not represent any limitation. Communication environment 100 may include any suitable number of communication devices, any suitable number of communication links, any suitable number of other elements, and cell 112 of any suitable shape suitable for implementing embodiments of this disclosure. Furthermore, it should be understood that various wireless and wired communications (if required) may be present among all communication devices.

[0047] Communication in communication environment 100 can be implemented according to any suitable communication protocol, including but not limited to cellular communication protocols such as first-generation (1G), second-generation (2G), third-generation (3G), fourth-generation (4G), and fifth-generation (5G), NR-U, wireless local network communication protocols (such as IEEE 802.11), and / or any other currently known or future-developed protocols. Furthermore, such communication can utilize any suitable wireless communication technology, including but not limited to Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiplexing (OFDM), Discrete Fourier Transform Spread Spectrum OFDM (DFT-s-OFDM), and / or any other currently known or future-developed technologies. Example methods

[0048] Figure 2 A flowchart of an example method 200 for destination selection according to some embodiments of the present disclosure is shown. In some embodiments, method 200 can be implemented in devices (such as...) within a communication network. Figure 1 The method is implemented at the terminal device 120-2 shown. Alternatively or concurrently, method 200 can be implemented at the terminal device 120-2 shown. Figure 1 The method 200 is implemented at other devices shown, and in some other embodiments, the method 200 may be implemented at other devices. Figure 1 The method is implemented at a device not shown in the diagram. Furthermore, it should be understood that method 200 may include additional boxes not shown and / or some boxes shown may be omitted, and the scope of this disclosure is not limited to this aspect. For the purposes of discussion, reference will be made to… Figure 1Method 200 is described from the perspective of terminal device 120-2.

[0049] At block 210, terminal device 120-2 receives channel occupancy time (COT) sharing information. At block 220, terminal device 120-2 determines, among one or more destinations to which the terminal device is to transmit data, whether there is at least one destination that satisfies a COT requirement associated with the COT sharing information. At block 230, terminal device 120-2 selects, based on a result of the determination, a destination for sidelink transmission from the one or more destinations. Thus, reliability and efficiency of sidelink communication can be improved.

[0050] For example, with reference to Figure 1 , terminal device 120-2 can perform multiplexing and assembly for MAC PDUs. Since each MAC PDU can only be transmitted to one destination, terminal device 120-2 can perform LCP procedure during multiplexing and assembly to select target destinations and corresponding logical channel(s) to be multiplexed into MAC PDUs. During destination selection, if there is no available COT sharing information, terminal device 120-2 can follow legacy procedure to select destinations, i.e., select destinations according to 5.22.1.4.1.2 in TS 38.321. Existing destination selection conditions in 5.22.1.4.1.2 in TS 38.321 are as follows:

[0051] On the other hand, if there is available COT sharing information (e.g., COT sharing information received from terminal device 120-1), the shared COT can be utilized by sidelink transmissions to destination(s) that satisfy COT requirements associated with the COT sharing information, which can not satisfy existing destination selection conditions in 5.22.1.4.1.2 in TS 38.321. As used hereinafter, such destinations can be referred to as “COT-allowed destinations”. Destinations that do not satisfy COT requirements associated with the COT sharing information can be referred to as “COT-not-allowed destinations”. The shared COT cannot be utilized by sidelink transmissions to COT-not-allowed destinations.

[0052] The terminal device 120-2 can determine whether there is at least one COT-allowed destination and select a destination based on the determination result. For example, if there is at least one COT-allowed destination and other conditions (if any) are satisfied, the terminal device 120-2 can perform destination selection based on the COT sharing information, i.e., perform a changed LCP procedure to take into account additional COT sharing restrictions in addition to the existing destination selection conditions described above in 5.22.1.4.1.2 in TS 38.321. If there is no COT-allowed destination and / or other conditions (if any) are not satisfied, the terminal device 120-2 can perform destination selection based on the legacy procedure, i.e., without taking into account the additional COT sharing restrictions.

[0053] Figure 3 An example block diagram for destination selection 300 is shown in accordance with some embodiments of the disclosure. For the purpose of discussion, reference will be made to Figure 1 The destination selection 300 is described from the perspective of the terminal device 120-2. As Figure 3 indicated, the terminal device 120-2 can have data in its buffer to be transmitted to multiple destinations (e.g., Dest#1 and Dest#2). Among these destinations, Dest#1 is not included in the destination ID(s) in the COT sharing information. Dest#2 is included in the destination ID(s) in the COT sharing information and has a logical channel with a CAPC priority equal to or higher than the CAPC priority in the COT sharing information. Thus, Dest#1 can be determined as a COT-not-allowed destination and Dest#2 can be determined as a COT-allowed destination. Thus, Dest#2 is selectable if other conditions (if any) are satisfied, e.g., if the highest priority of all logical channels associated with Dest#2 is higher than or equal to all logical channels associated with the destination of the terminal device 120-2.

[0054] In the following, some embodiments of conditions taking / not taking into account additional COT sharing restrictions will be described in detail. Other embodiments are also possible.

[0055] In some embodiments, the terminal device 120-2 can select a destination based on the COT sharing information if there is at least one destination that satisfies the COT requirement. In other words, if there is available COT sharing information and there is at least one COT-allowed destination, the terminal device 120-2 can take into account additional COT sharing restrictions in addition to the existing destination selection conditions described above in 5.22.1.4.1.2 in TS 38.321. Otherwise, the terminal device 120-2 can not take into account the additional COT sharing restrictions.

[0056] In some embodiments, there can be at least one destination that satisfies the COT requirement. If a condition associated with the at least one destination is satisfied, the terminal device 120-2 can select a destination based on the COT sharing information.

[0057] Embodiments of the condition associated with the at least one destination can be explained with reference to a specific implementation. For example, the COT sharing information can include destination ID(s) #1, #2, #3 and CAPC priority 2. In the buffer of the terminal device 120-2, there can be data to destinations with destination ID(s) #1, #2, #3, #4 and #5. These destinations can correspond to the following logical channels (LCHs) with corresponding CAPC priorities and LCH priorities:

[0058] Destination ID #1: LCH #1 (CAPC = 1, LCH priority = 3), LCH #2 (CAPC = 2, LCH priority = 3), LCH #3 (CAPC = 3, LCH priority = 4);

[0059] Destination ID #2: LCH #1 (CAPC = 1, LCH priority = 4), LCH #2 (CAPC = 1, LCH priority = 3), LCH #3 (CAPC = 2, LCH priority = 4);

[0060] Destination ID #4: LCH #1 (CAPC = 1, LCH priority = 2), LCH #2 (CAPC = 2, LCH priority = 2), LCH #3 (CAPC = 3, LCH priority = 4);

[0061] Destination ID #5: LCH #1 (CAPC = 1, LCH priority = 3), LCH #2 (CAPC = 2, LCH priority = 3), LCH #3 (CAPC = 3, LCH priority = 4).

[0062] Destinations with destination IDs #1 and #2 satisfy the requirement that their destination IDs belong to the destination ID(s) in the shared COT information, and they have logical channel(s) with CAPC priority equal to or higher than the CAPC priority in the shared COT information. Therefore, the destinations with destination IDs #1 and #2 can be determined as COT allowed destinations, and the destinations with destination IDs #4 and #5 can be determined as COT not allowed destinations.

[0063] In some embodiments, the condition can include that a LCH among at least one LCH associated with at least one destination has a highest LCH priority among one or more LCH priorities associated with one or more destinations. In other words, if there is available COT sharing information, there is at least one COT allowed destination, and there is no other destination including a higher priority logical channel than all COT allowed destinations, the terminal device 120-2 can consider additional COT sharing restrictions in addition to the above existing destination selection conditions in 5.22.1.4.1.2 in TS 38.321. Otherwise, the terminal device 120-2 can not consider additional COT sharing restrictions. For example, in the above example implementation, the destination with destination ID #4 includes logical channel LCH #1 with LCH priority of 2, which is higher than all logical channel priorities of COT allowed destinations with destination IDs #1 and #2. Thus, the terminal device 120-2 can not consider additional COT sharing restrictions.

[0064] In some embodiments, a LCH priority associated with remaining destinations among one or more destinations except at least one destination can be higher than a highest LCH priority among at least one LCH priority associated with the at least one destination. The condition can include that the highest LCH priority associated with the remaining destinations is equal to or lower than a priority threshold. In other words, if there is available COT sharing information, there is at least one COT allowed destination, there is one or more destinations including a higher priority logical channel than all COT allowed destinations, and the highest LCH priority of such destination is not higher than a configured priority threshold, the terminal device 120-2 can consider additional COT sharing restrictions in addition to the above existing destination selection conditions in 5.22.1.4.1.2 in TS 38.321. Otherwise, the terminal device 120-2 can not consider additional COT sharing restrictions. For example, in the above example implementation, while the destination with destination ID #4 includes logical channel LCH #1 with LCH priority of 2, which is higher than all logical channel priorities of COT allowed destinations with destination IDs #1 and #2, its LCH channel priority is not higher than a configured priority threshold 1. Thus, the terminal device 120-2 can consider additional COT sharing restrictions, i.e., perform destination selection based on COT sharing information.

[0065] In some embodiments, the LCH priority associated with the remaining destinations among the one or more destinations other than the at least one destination can be higher than the highest LCH priority among the at least one LCH priority associated with the at least one destination. The condition can include that the LCH priority associated with the remaining destinations is not included in a priority list configured by an upper layer of the terminal device. In other words, if there is available COT sharing information, there is at least one COT allowed destination, there is one or more destinations including a logical channel with a higher priority than all COT allowed destinations, and the highest LCH priority of such destinations is not included in the priority list configured by the higher layer, the terminal device 120-2 can consider an additional COT sharing restriction in addition to the above existing destination selection condition in 5.22.1.4.1.2 in TS 38.321. Otherwise, the terminal device 120-2 can not consider the additional COT sharing restriction.

[0066] In some embodiments, the LCH priority associated with the remaining destinations among the one or more destinations other than the at least one destination can be higher than the highest LCH priority among the at least one LCH priority associated with the at least one destination. The condition can include that the minimum of at least one remaining packet delay budget (PDB) of at least one LCH associated with the remaining destinations is equal to or higher than a PDB threshold. In other words, if there is available COT sharing information, there is at least one COT allowed destination, there is one or more destinations including a logical channel with a higher priority than all COT allowed destinations, and the minimum remaining PDB of such destinations is not lower than the configured threshold, the terminal device 120-2 can consider an additional COT sharing restriction in addition to the above existing destination selection condition in 5.22.1.4.1.2 in TS 38.321. Otherwise, the terminal device 120-2 can not consider the additional COT sharing restriction. For example, in the above example implementation, if the configured remaining PDB threshold is 20 ms, and the remaining PDB of the destination with destination ID #4 is 40 ms, which is not shorter than the configured remaining PDB threshold, the terminal device 120-2 can consider the additional COT sharing restriction, i.e., perform destination selection based on the COT sharing information.

[0067] In some embodiments, the LCH priority associated with the remaining destinations among the one or more destinations other than the at least one destination can be higher than the highest LCH priority among the at least one LCH priority associated with the at least one destination. The condition can include that there is sidelink shared channel resource in the minimum among the at least one remaining PDB of the at least one LCH associated with the remaining destinations. In other words, if there is available COT sharing information, there is at least one COT allowed destination, there is one or more destinations including a logical channel with a higher priority than all COT allowed destinations, and there is SL-SCH resource in the minimum remaining PDB of such destinations, the terminal device 120-2 can consider additional COT sharing restrictions in addition to the above existing destination selection conditions in 5.22.1.4.1.2 in TS 38.321. Otherwise, the terminal device 120-2 can not consider the additional COT sharing restrictions. For example, in the above example implementation, if there is SL-SCH resource in the minimum remaining PDB of the destination with destination ID #4, the terminal device 120-2 can consider the additional COT sharing restrictions, i.e., perform destination selection based on COT sharing information.

[0068] In some embodiments, the LCH priority associated with the remaining destinations among the one or more destinations other than the at least one destination can be higher than the highest LCH priority among the at least one LCH priority associated with the at least one destination. The condition can include that the size of the priority sidelink bucket of each LCH of the at least one LCH associated with the remaining destinations is smaller than a size threshold. In other words, if there is available COT sharing information, there is at least one COT allowed destination, there is one or more destinations including a logical channel with a higher priority than all COT allowed destinations, and the SBj of any logical channel of such destinations is smaller than the sidelink bucket size, the terminal device 120-2 can consider additional COT sharing restrictions in addition to the above existing destination selection conditions in 5.22.1.4.1.2 in TS 38.321. Otherwise, the terminal device 120-2 can not consider the additional COT sharing restrictions.

[0069] In some embodiments, the condition can include that at least one medium access control (MAC) control element (CE) is to be transmitted to a remaining one or more destinations among the one or more destinations except for at least one destination, and the MAC CE has a higher priority than a transmission to the at least one destination. In other words, if there is available COT sharing information, there is at least one COT allowed destination, and there is one or more destinations including a higher priority MAC CE than all COT allowed destinations, the terminal device 120-2 can consider an additional COT sharing restriction in addition to the above existing destination selection condition in 5.22.1.4.1.2 in TS 38.321.

[0070] In some embodiments, the COT sharing information can be associated with multiple shared COTs. In other words, there are multiple available COTs that can be utilized by the terminal device 120-2. For example, the terminal device 120-2 can receive first COT sharing information from the terminal device 120-1, second COT sharing information from the terminal device 120-3, and third COT sharing information from the terminal device 120-4. The terminal device 120-2 can utilize multiple COTs occupied by the terminal devices 120-1, 120-3, and 120-4. The terminal device 120-2 can determine a first set of COT allowed destinations corresponding to the first COT sharing information, a second set of COT allowed destinations corresponding to the second COT sharing information, and a third set of COT allowed destinations corresponding to the third COT sharing information.

[0071] In some embodiments, when selecting a destination based on the COT sharing information, the terminal device 120-2 can select a destination associated with a highest LCH priority among one or more LCH priorities associated with the one or more destinations from the one or more destinations. In other words, if the terminal device 120-2 determines to perform LCP considering an additional COT sharing restriction in addition to the existing destination selection condition in 5.22.1.4.1.2 in TS 38.321, the terminal device 120-2 can select a destination having a highest LCH priority among all COT allowed destinations.

[0072] In some embodiments, when selecting a destination based on the COT sharing information, the terminal device 120-2 can select a destination from one or more destinations that satisfies the COT requirement associated with the shared COT among the multiple shared COTs if the remaining duration of the shared COT is shorter than a duration threshold. In other words, if the terminal device 120-2 determines to perform LCP considering additional COT sharing restrictions beyond the existing destination selection conditions in 5.22.1.4.1.2 in TS 38.321, the terminal device 120-2 can prioritize a destination among all COT-allowed destinations if the remaining shared COT duration of the COT corresponding to the destination is below a remaining COT threshold.

[0073] Another specific aspect for destination selection for sidelink transmission is assistance information from a responding UE to facilitate COT sharing by an initiating UE. In addition to transmitting to the initiating UE using the shared COT, the responding UE can also transmit to a broadcast or groupcast destination. The initiating UE can be a potential receiver for the broadcast or groupcast transmission. The initiating UE can always include the destination IDs that it is interested in in the allowed destination ID list in the COT sharing information, but such a solution can incur a large amount of signaling.

[0074] In some embodiments, the responding UE can send assistance information to the initiating UE indicating that it has data to send to the destination IDs for broadcast and groupcast. For example, the responding UE can transmit assistance information to the initiating UE to assist the initiating UE to better share its COT in order to improve the responding UE’s probability of utilization. For example, the responding UE can send a list of destination IDs of the responding UE to the initiating UE for transmission. If one or more of the destination IDs are also the receiving destinations of the initiating UE, the initiating UE can include these destination ID(s) in the COT sharing information to enable the responding UE to use the initiating UE’s shared COT to send data to these destinations.

[0075] In some embodiments, the terminal device can be a first terminal device. The terminal device can send assistance information for COT sharing to a second terminal device via PC5 radio resource control (RRC) signaling. For example, as a responding UE, the terminal device 120-2 can send assistance information for COT sharing to the terminal device 120-1 via PC5 RRC signaling (e.g., a UEAssistanceInformationSidelink message). The UEAssistanceInformationSidelink message can be used to send SL-DRX assistance information. In some embodiments, the UEAssistanceInformationSidelink message can also carry assistance information for COT sharing.

[0076] In some embodiments, the assistance information can include at least one of a list of destination identifiers or a traffic pattern of the first terminal device. In some embodiments, the PC5 RRC signaling can include at least one index of at least one destination identifier in the list of destination identifiers. In other words, in addition to the destination ID(s) of the responding UE (for transmission), a traffic pattern including traffic periodicity and start offset can also be included in the assistance information for COT sharing.

[0077] In some embodiments, the PC5 RRC signaling can be triggered based on establishment of a unicast connection between the first terminal device (e.g., the responding UE) and the second terminal device (e.g., the initiating UE). In some embodiments, the PC5 RRC signaling can be triggered based on a capability exchange between the first terminal device (e.g., the responding UE) and the second terminal device (e.g., the initiating UE). In some embodiments, the PC5 RRC signaling can be triggered based on a PC5 RRC reconfiguration exchange between the first terminal device (e.g., the responding UE) and the second terminal device (e.g., the initiating UE). In some embodiments, the PC5 RRC signaling can be triggered based on establishment of a sidelink data radio bearer (SL-DRB). In some embodiments, the PC5 RRC signaling can be triggered based on an update of the SL-DRB. In some embodiments, the PC5 RRC signaling can be triggered based on a release of the SL-DRB. In some embodiments, the PC5 RRC signaling can be triggered based on an update of a list of destination identifiers of the first terminal device (e.g., the responding UE). If assistance information for COT sharing is initiated, the responding UE can send the assistance information to the initiating UE. After the initiating UE receives the assistance information for COT sharing from its peer UE, if it is in RRC_CONNECTED mode or resource allocation mode 1 (i.e., dynamic scheduling mode), the initiating UE can report the COT sharing assistance information to the eNB or gNB.

[0078] In some embodiments, the terminal device can be a first terminal device. The terminal device can transmit, to a second terminal device, assistance information for COT sharing in a MAC CE. The assistance information can comprise an indication that the terminal device has a destination to which data is to be transmitted. For example, in addition to RRC signaling, a MAC CE can be transmitted to indicate more dynamically the destination IDs of responding UEs. More specifically, the MAC CE can indicate those destination IDs with data in the buffer of the first terminal device for transmission.

[0079] In some embodiments, the MAC CE can comprise a bitmap with values for indices of destination identifiers of the first terminal device. A first value in the bitmap for an index can indicate that there is data to be transmitted to a destination associated with the index. A second value in the bitmap for an index can indicate that there is no data to be transmitted to a destination associated with the index. For example, the bitmap can be designed to indicate indices of destination IDs, e.g., if there is data for a destination ID, a value “1” can be set for the particular destination ID, and if there is no data for a destination ID, a value “0” can be set for the particular destination ID. The number of indicated destination IDs can be equal to the number of destination IDs in the assistance information in the RRC signaling. The indices of the destination IDs can be indices of the destination IDs in the list of destination IDs of the RRC signaling.

[0080] In some embodiments, the MAC CE can be triggered if data arrives in the buffer of the first terminal device for a destination and there was no data in the buffer before the data arrived. In some embodiments, the MAC CE can be triggered if all data in the buffer of the first terminal device for a destination has been transmitted, i.e., the data in the buffer has been cleared.

[0081] In some embodiments, the MAC CE can be cancelled if the buffer of the first terminal device for a destination changes from a first state back to a second state, which was indicated in a previous MAC CE transmitted by the first terminal device to the second terminal device before the MAC CE was transmitted. In other words, the buffer status of the destination ID(s) (i.e., whether there is data in the buffer for transmission) is changed back / not changed compared to the last reported MAC CE. Example apparatus

[0082] Figure 4 A simplified block diagram of a device 400 suitable for implementing embodiments of the present disclosure is shown. The device 400 can be considered as a terminal device 120. Figure 1 Another example implementation of a terminal device 120 is shown.

[0083] As illustrated, the device 400 includes a processor 410, a memory 420 coupled to the processor 410, a suitable transmitter (TX) and receiver (RX) 440 coupled to the processor 410, and a communication interface coupled to the TX / RX 440. The memory 410 stores at least a portion of a program 430. The TX / RX 440 is for bidirectional communication. While in practice an access node referred to by the present disclosure can have multiple antennas, the TX / RX 440 has at least one antenna to facilitate communication. The communication interface can represent any interface needed to communicate with other network elements, such as an X2 interface for bidirectional communication between eNBs or gNBs, an S1 interface for communication between a mobility management entity (MME) / serving gateway (S-GW) and eNBs or gNBs, a Uu interface for communication between eNBs or gNBs or relay nodes (RNs), or a Uu interface for communication between eNBs or gNBs and terminal devices.

[0084] The program 430 is assumed to include program instructions that, when executed by the associated processor 410, enable the device 400 to operate in accordance with the embodiments of the present disclosure, as discussed herein with reference to Figure 1 The embodiments herein can be implemented by computer software executable by the processor 410 of the device 400, or by hardware, or by a combination of software and hardware. The processor 410 can be configured to implement various embodiments of the present disclosure. Moreover, a combination of the processor 410 and the memory 420 can form a processing means 440 adapted to implement various embodiments of the present disclosure.

[0085] The memory 420 can be of any type appropriate for the local technical network and can be implemented using any suitable data storage technology, such as nonvolatile computer-readable storage media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. While only one memory 420 is shown in the device 400, there can be several physically different memory modules in the device 400. The processor 410 can be of any type appropriate for the local technical network, and can include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multi-core processor architectures, as non-limiting examples. The device 400 can have multiple processors such as a special purpose integrated circuit chip that is time-slaved to a clock that is synchronized with a master processor.

[0086] In some embodiments, an apparatus, e.g., terminal device 120-2, capable of performing the method 200 can include means for performing the corresponding steps of the method 200. The means can be implemented in any suitable form. For example, they can be implemented in hardware or software in circuitry or a software module. In some embodiments, the means include at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause performance of the method 200.

[0087] In general, the various embodiments of the disclosure can be implemented in hardware or special-purpose circuits, software, logic or any combination thereof. Some aspects can be implemented in hardware, while other aspects can be implemented in firmware or software which can be executed by a controller, microprocessor or other computing device. While various aspects of an embodiment of the disclosure are illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein can be implemented in, as non-limiting examples, hardware, software, firmware, special-purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0088] The disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, executed by devices on a target real or virtual processor to perform the processes or methods described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The functionality of the program modules can be combined or distributed as desired in various embodiments. Machine-executable instructions for program modules can be executed within a local or distributed device. In a distributed device, program modules can be located in both local and remote storage media.

[0089] Program code for carrying out methods of the present disclosure can be written in any combination of one or more programming languages. This program code can be provided to a processor or controller of a general purpose computer, special purpose processor or other programmable data processing apparatus to produce a machine, such that the code, which executes on the processor or controller, produces the functions / operations specified in the flowcharts and / or the block diagrams. The program code can be executed entirely on a machine, partly on a machine and partly on a remote machine or entirely on a remote machine or server.

[0090] The procedures described above can be embodied on a machine-readable medium, which can be any tangible medium that can include or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable storage media can include, without limitation, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0091] Moreover, while operations can be described as following a specific order, this should not be understood as requiring that such operations be performed in the particular order described or in sequential order, or that all described operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing can be advantageous. Likewise, while specific implementations are described herein, the scope of the disclosure is not limited to the specific details and representations as described in the foregoing description. Certain features that are described in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination.

[0092] While the disclosure has been described in language specific to structural features and / or methodological acts, it is to be understood that the subject of the appended claims need not be limited to the specific features or acts described. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

[0093] Embodiments of the disclosure can be additionally described using the following clauses.

[0094] Clause 1. A terminal device comprising: a processor; and a transceiver coupled to the processor, wherein the processor is configured to: receive channel occupancy time (COT) sharing information via the transceiver; determine, among one or more destinations to which the terminal device is to transmit data, whether there is at least one destination that satisfies a COT requirement associated with the COT sharing information; and select, based on a result of the determination, a destination for sidelink transmission from the one or more destinations.

[0095] Clause 2. The terminal device of Clause 1, wherein selecting the destination comprises: in a case that there is at least one destination that satisfies the COT requirement, selecting the destination based on the COT sharing information.

[0096] Clause 3. The terminal device of Clause 1, wherein there is at least one destination that satisfies the COT requirement, and selecting the destination comprises: in a case that a condition associated with the at least one destination is satisfied, selecting the destination based on the COT sharing information.

[0097] Clause 4. The terminal device of Clause 3, wherein the condition comprises: a logical channel (LCH) among at least one LCH associated with the at least one destination, the LCH having a highest LCH priority among one or more LCH priorities associated with the one or more destinations.

[0098] Clause 5. The terminal device of Clause 3, wherein a LCH priority associated with a remaining destination among the one or more destinations other than the at least one destination is higher than a highest LCH priority among at least one LCH priority associated with the at least one destination, and wherein the condition comprises one of:

[0099] a highest LCH priority associated with the remaining destination is equal to or lower than a priority threshold;

[0100] a highest LCH priority associated with the remaining destination is not included in a priority list configured by an upper layer of the terminal device;

[0101] a minimum among at least one remaining packet delay budget (PDB) of at least one LCH associated with the remaining destination is equal to or higher than a PDB threshold;

[0102] there is a sidelink shared channel resource in the minimum among the at least one remaining PDB of the at least one LCH associated with the remaining destination;

[0103] a size of a prioritized sidelink bucket for each LCH among the at least one LCH associated with the remaining destination is smaller than a size threshold.

[0104] Clause 6. The terminal device of Clause 3, wherein the condition comprises: at least one medium access control (MAC) control element (CE) is to be transmitted to a remaining destination among the one or more destinations other than the at least one destination, and the MAC CE has a higher priority than a transmission to the at least one destination.

[0105] Clause 7. The terminal device of Clause 2 or 3, wherein the COT sharing information is associated with a plurality of shared COTs.

[0106] Clause 8. The terminal device of clause 7, wherein selecting the destination based on the COT sharing information comprises one of: selecting, from the one or more destinations, a destination associated with a highest LCH priority among one or more LCH priorities associated with the one or more destinations; or selecting, from the one or more destinations, a destination that satisfies a COT requirement associated with a shared COT of the plurality of shared COTs, in a case that a remaining duration of the shared COT is shorter than a duration threshold.

[0107] Clause 9. The terminal device of clause 1, wherein the terminal device is a first terminal device, and wherein the processor is further configured to: transmit, to a second terminal device, assistance information for COT sharing via PC5 radio resource control (RRC) signaling.

[0108] Clause 10. The terminal device of clause 9, wherein the assistance information comprises at least one of: a list of destination identifiers of the first terminal device or a traffic pattern.

[0109] Clause 11. The terminal device of clause 10, wherein the PC5 RRC signaling comprises at least one index of at least one destination identifier in the list of destination identifiers.

[0110] Clause 12. The terminal device of clause 9, wherein the PC5 RRC signaling is triggered based on one of: establishment of a unicast connection between the first terminal device and the second terminal device; capability exchange between the first terminal device and the second terminal device; PC5 RRC reconfiguration exchange between the first terminal device and the second terminal device; establishment of a sidelink data radio bearer (SL-DRB); update of the SL-DRB; release of the SL-DRB; or update of the list of destination identifiers of the first terminal device.

[0111] Clause 13. The terminal device of clause 1, wherein the terminal device is a first terminal device, and wherein the processor is further configured to: transmit, to a second terminal device, assistance information for COT sharing in a MAC CE, wherein the assistance information comprises an indication that the terminal device has a destination to which data is to be transmitted.

[0112] Clause 14. The terminal device of clause 13, wherein the MAC CE comprises a bitmap having values for indices of destination identifiers of the first terminal device, and wherein a first value in the bitmap for an index indicates that there is data to be transmitted to a destination associated with the index, and a second value in the bitmap for the index indicates that there is no data to be transmitted to the destination associated with the index.

[0113] Clause 15. The terminal device of clause 13, wherein the MAC CE is triggered based on one of: arrival of data at a buffer of the first terminal device for the destination, and no data in the buffer prior to the arrival of the data; or all data in the buffer of the first terminal device for the destination is being transmitted.

[0114] Clause 16. The terminal device of clause 13, wherein the MAC CE is cancelled based on the buffer of the first terminal device for the destination changing from a first state to a second state prior to the MAC CE being transmitted, the second state being indicated in a previous MAC CE transmitted by the first terminal device to the second terminal device.

[0115] Clause 17. A method performed by a terminal device, comprising: receiving channel occupancy time (COT) sharing information; determining whether there is at least one of one or more destinations to which the terminal device is to transmit data that meets a COT requirement associated with the COT sharing information; and selecting a destination for a sidelink transmission from the one or more destinations based on a result of the determining.

[0116] Clause 18. A non-transitory computer readable medium having program instructions stored thereon that, when executed by an apparatus, cause the apparatus to at least: receive channel occupancy time (COT) sharing information; determine whether there is at least one of one or more destinations to which the terminal device is to transmit data that meets a COT requirement associated with the COT sharing information; and select a destination for a sidelink transmission from the one or more destinations based on a result of the determining.

Claims

1. A terminal device, comprising: processor; as well as The transceiver coupled to the processor, The processor is configured as follows: Channel Occupancy Time (COT) shared information is received via the transceiver; Determine whether, among one or more destinations to which the terminal device is to send data, there exists at least one destination that meets the COT requirements associated with the COT shared information; as well as Based on the determined results, a destination for sidelink transmission is selected from the one or more destinations.

2. The terminal device according to claim 1, wherein selecting the destination includes: If at least one destination that meets the COT requirements exists, the destination is selected based on the COT shared information.

3. The terminal device according to claim 1, wherein there exists at least one destination that satisfies the COT requirement, and selecting the destination includes: If the conditions associated with the at least one destination are met, the destination is selected based on the COT shared information.

4. The terminal device according to claim 3, wherein the conditions include: An LCH among at least one logical channel LCH associated with the at least one destination, the LCH having the highest LCH priority among one or more LCH priorities associated with the one or more destinations.

5. The terminal device of claim 3, wherein the LCH priority associated with the remaining destinations among the one or more destinations other than the at least one destination is higher than the highest LCH priority among the at least one LCH priority associated with the at least one destination, and wherein the condition includes one of the following: The highest LCH priority associated with the remaining destination is equal to or lower than the priority threshold; The highest LCH priority associated with the remaining destination is not included in the priority list configured by the upper layer of the terminal device; The minimum value in at least one remaining packet delay budget (PDB) of at least one LCH associated with the remaining destination is equal to or higher than the PDB threshold; There is a sidelink shared channel resource in the minimum of at least one remaining PDB of at least one LCH associated with the remaining destination; The size of the preferred sidelink bucket of each LCH in at least one LCH associated with the remaining destination is less than the size threshold.

6. The terminal device according to claim 1, wherein the terminal device is a first terminal device, and wherein the processor is further configured to: Auxiliary information for COT sharing is sent to the second terminal device via PC5 Radio Resource Control (RRC) signaling.

7. The terminal device according to claim 6, wherein the auxiliary information includes at least one of the following: a list of destination identifiers or a service mode of the first terminal device.

8. The terminal device according to claim 7, wherein the PC5 RRC signaling includes: At least one index of at least one destination identifier in the list of destination identifiers.

9. The terminal device of claim 6, wherein the PC5 RRC signaling is triggered based on one of the following: Establishment of a unicast connection between the first terminal device and the second terminal device; Capability exchange between the first terminal device and the second terminal device; PC5 RRC reconfiguration exchange between the first terminal device and the second terminal device; Establishment of the sidelink data radio bearer SL-DRB; SL-DRB update; The release of SL-DRB; or Update the destination identifier list of the first terminal device.

10. The terminal device according to claim 1, wherein the terminal device is a first terminal device, and wherein the processor is further configured to: Sending auxiliary information for COT sharing in MAC CE to the second terminal device, wherein the auxiliary information includes: The terminal device has an indication of the destination of the data to be sent to it.

11. The terminal device of claim 10, wherein the MAC CE includes a bitmap having a value for an index of a destination identifier for the first terminal device, and A first value in the bitmap used for the index indicates that there is data to be sent to a destination associated with the index, and a second value in the bitmap used for the index indicates that there is no data to be sent to a destination associated with the index.

12. The terminal device of claim 10, wherein the MAC CE is triggered based on one of the following: Data arriving at the cache of the first terminal device for the destination, and there was no data in the cache prior to the arrival of the data; or All data in the cache of the first terminal device destined for the destination is being sent.

13. The terminal device of claim 10, wherein the MAC CE is cancelled based on the following: Before the MAC CE is sent, the cache of the first terminal device for the destination changes from a first state to a second state, which was indicated in a previous MAC CE sent by the first terminal device to the second terminal device.

14. A method executed by a terminal device, comprising: Receive channel occupancy time COT shared information; Determine whether, among one or more destinations to which the terminal device is to send data, there exists at least one destination that meets the COT requirements associated with the COT shared information; as well as Based on the determined results, a destination for sidelink transmission is selected from the one or more destinations.

15. A non-transitory computer-readable medium having program instructions stored thereon, the program instructions, when executed by a device, causing the device to at least: Receive channel occupancy time COT shared information; Determine whether, among one or more destinations to which the terminal device is to send data, there exists at least one destination that meets the COT requirements associated with the COT shared information; as well as Based on the determined results, a destination for sidelink transmission is selected from the one or more destinations.

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