Channel occupancy time for sidelink communications in unlicensed bands

Abstract

Embodiments of the present disclosure relate to devices, methods, apparatuses, and computer-readable storage media for channel occupancy time (COT) for sidelink (SL) communication in an unlicensed band (U-band). The method includes: receiving, at a first device and from a second device, configuration information associated with a COT, the COT being at least used for SL transmission of a first device on an unlicensed resource pool allocated for the first device, the configuration information at least indicating whether a listen-before-talk process needs to be performed at the first device within the COT before SL transmission; and performing SL transmission within the COT based on the configuration information. In this way, a COT sharing mechanism can be used for SL communication in the U-band, so that the sensing process for resource selection can be unaffected by the LBT process.

Description

Technical Field

[0001] Embodiments of the present disclosure relate generally to the field of telecommunications, and in particular to devices, methods, apparatus, and computer-readable storage media for channel occupancy time (COT) for sidelink (SL) communications in an unlicensed band (U-band). Background Art

[0002] As specified in 3GPP, SL communication between user equipments (UEs) via the PC5 interface is based on the principle of a transmitting UE (Tx UE) for one-to-many broadcast. This means that in principle, no connection establishment is required for SL communication between UEs at the radio access level, regardless of whether the SL communication is for unicast, multicast or broadcast services.

[0003] On the one hand, the Tx UE may use resources from a pre-configured resource pool to send at least a link control information (SCI) to a receiving UE (Rx UE) or a group of Rx UEs or all Rx UEs in the vicinity of the Tx UE, and the SCI is used as a scheduling assignment for SL data transmission. On the other hand, the Rx UE needs to keep monitoring on the pre-configured resource pool to receive SL transmission, at least receive all SCI instances, and determine whether the received SCI and the corresponding SL data transmission are for Rx UE reception. Summary of the invention

[0004] In general, example embodiments of the present disclosure provide a solution for COT for SL communications in the U-band.

[0005] In a first aspect, a first device is provided. The first device includes at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, together with the at least one processor, cause the first device to at least: receive configuration information associated with a channel occupancy time from a second device, the channel occupancy time being used at least for a sidelink transmission of the first device on an unlicensed resource pool allocated for the first device; and perform sidelink transmission within the channel occupancy time based on the configuration information.

[0006] In a second aspect, a second device is provided. The second device includes at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, together with the at least one processor, cause the second device to at least: determine a channel occupancy time, the channel occupancy time being at least used for a sidelink transmission of a first device on an unlicensed resource pool allocated for the first device; generate configuration information associated with the channel occupancy time, the configuration information at least indicating whether a listen-before-talk procedure needs to be performed at the first device during the channel occupancy time before the sidelink transmission; and transmit the configuration information to the first device.

[0007] In a third aspect, a method is provided. The method includes: receiving, at a first device, configuration information associated with a channel occupancy time from a second device, the channel occupancy time being used at least for a sidelink transmission of the first device on an unlicensed resource pool allocated for the first device. The configuration information at least indicates whether a listen-before-talk procedure needs to be performed at the first device during the channel occupancy time before the sidelink transmission; and performing the sidelink transmission during the channel occupancy time based on the configuration information.

[0008] In a fourth aspect, a method is provided. The method includes: determining a channel occupancy time, the channel occupancy time being used for at least a sidelink transmission of a first device on an unlicensed resource pool allocated for the first device; generating configuration information associated with the channel occupancy time, the configuration information at least indicating whether a listen-before-talk procedure needs to be performed at the first device during the channel occupancy time before the sidelink transmission; and sending the configuration information to the first device.

[0009] In a fifth aspect, a device is provided, comprising: a component for receiving configuration information associated with a COT from a second device at a first device, the COT being at least used for SL transmission of the first device on an unauthorized resource pool allocated for the first device, the configuration information at least indicating whether a listen-before-talk procedure needs to be performed at the first device within the COT before SL transmission; and a component for performing SL transmission within the COT based on the configuration information.

[0010] In a sixth aspect, a device is provided, comprising: a component for determining a channel occupancy time, the channel occupancy time being at least used for a side link transmission of a first device on an unauthorized resource pool allocated for the first device; a component for generating configuration information associated with a COT, the configuration information at least indicating whether a listen-before-talk process needs to be performed at the first device within the COT before SL transmission; and a component for sending the configuration information to the first device.

[0011] In a seventh aspect, there is provided a computer readable medium having stored thereon a computer program which, when executed by at least one processor of a device, causes the device to perform the method according to the third aspect.

[0012] In an eighth aspect, there is provided a computer readable medium having stored thereon a computer program which, when executed by at least one processor of a device, causes the device to perform the method according to the fourth aspect.

[0013] Other features and advantages of the embodiments of the present disclosure will also become apparent from the following description of specific embodiments when read in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the embodiments of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The embodiments of the present disclosure are presented in exemplary sense and their advantages are explained in more detail below with reference to the accompanying drawings, in which

[0015] Figure 1 illustrates an example communication network 100 in which example embodiments of the present disclosure may be implemented;

[0016] Figure 2 shows a signaling diagram of a COT procedure for SL communication in U-band according to some example embodiments of the present disclosure;

[0017] Figure 3A and 3B An example of transmitting a signal for maintaining a COT according to some example embodiments of the present disclosure is shown;

[0018] Figure 4 A flowchart illustrating an example method for COT in the U-band for SL communications according to some example embodiments of the present disclosure;

[0019] Figure 5 A flowchart showing an example method for COT in U-band for SL communication according to some example embodiments of the present disclosure;

[0020] Figure 6 shows a simplified block diagram of a device suitable for implementing an example embodiment of the present disclosure; and

[0021] Figure 7 A block diagram of an example computer-readable medium is shown in accordance with some embodiments of the present disclosure.

[0022] Throughout the drawings, the same or similar reference numerals refer to the same or similar elements. DETAILED DESCRIPTION

[0023] The principles of the present disclosure will now be described with reference to some example embodiments. It should be understood that these embodiments are described for illustrative purposes only and to help those skilled in the art understand and implement the present disclosure without implying any limitation on the scope of the present disclosure. The disclosure described herein can be implemented in various ways different from the ways described below.

[0024] In the following description and claims, unless defined otherwise, 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 belongs.

[0025] References in this disclosure to "one embodiment," "an embodiment," "an example embodiment," etc., indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes the particular feature, structure, or characteristic. Furthermore, these phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in conjunction with an exemplary embodiment, it is considered to be within the knowledge of those skilled in the art to affect such feature, structure, or characteristic in conjunction with other embodiments (whether or not explicitly described).

[0026] It should be understood that although the terms "first" and "second", etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish the functions of the various elements. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0027] The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the 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 also be understood that the terms "include", "comprise", "have", "have", "include" and / or "comprising" when used herein specify the presence of stated features, elements and / or components, etc., but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof.

[0028] As used in this application, the term "circuitry" may refer to one, more than one, or all of the following:

[0029] (a) only hardware circuit implementation (e.g., only implementation in analog and / or digital circuits) and

[0030] (b) a combination of hardware circuitry and software, such as (where applicable):

[0031] (i) a combination of analog and / or digital hardware circuitry and software / firmware, and

[0032] (ii) a hardware processor (including a digital signal processor) with software, software and any portion of memory that work together to enable a device such as a mobile phone or server to perform various functions) and

[0033] (c) Hardware circuits and / or processors (e.g., a microprocessor or a portion of a microprocessor) that require software (e.g., firmware) to operate, but where software is not required to operate, the software may not be present.

[0034] This definition of circuitry applies to all uses of this term in this application, including in any claims. As another example, as used in this application, the term circuitry also covers an implementation of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or its) accompanying software and / or firmware. The term circuitry also covers (for example and if applicable to a particular claim element) a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in a server, a cellular network device or other computing or network device.

[0035] As used herein, the term "communication network" refers to a network that follows any suitable communication standard, such as a fifth generation (5G) system, long term evolution (LTE), advanced LTE (LTE-A), wideband code division multiple access (WCDMA), high speed packet access (HSPA), narrowband Internet of Things (NB-IoT), etc. In addition, the communication between the terminal device and the network device in the communication network can be performed according to any suitable generation of communication protocols, including but not limited to the first generation (1G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the future fifth generation (5G) new radio (NR) communication protocol, and / or any other protocol currently known or to be developed in the future. The embodiments of the present disclosure can be applied to various communication systems. In view of the rapid development of communication, there are of course future types of communication technologies and systems, using which the present disclosure can be implemented. It should not be regarded as limiting the scope of the present invention to the above-mentioned systems.

[0036] As used herein, the term "network device" refers to a node in a communication network via which a terminal device accesses the network and receives services from it. Depending on the terminology and technology applied, a network device may refer to a base station (BS) or an access point (AP), such as a Node B (Node B or NB), an evolved Node B (eNodeB or eNB), a NR next-generation Node B (gNB), a remote radio unit (RRU), a radio head (RH), a remote radio head (RRH), a relay, a low-power node such as a femto, a pico, etc. The RAN split architecture includes a gNB-CU (centralized unit, hosting RRC, SDAP, and PDCP) that controls multiple gNB-DUs (distributed units, hosting RLC, MAC, and PHY). A relay node may correspond to the DU portion of an IAB node.

[0037] The term "terminal device" refers to any terminal device capable of wireless communication. By way of example and not limitation, a terminal device may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS) or access terminal (AT). The terminal device may include, but is not limited to, a mobile phone, a cellular phone, a smart phone, a voice over IP (VoIP) phone, a wireless local loop phone, a tablet computer, 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 device, a vehicle-mounted wireless terminal device, a wireless endpoint, a mobile station, a laptop embedded device (LEE), a laptop mounted device (LME), USB dongles, smart devices, wireless client equipment (CPE), an Internet of Things (IoT) device, a watch or other wearable device, a head mounted display (HMD), a vehicle, a target, medical equipment and applications (e.g., remote surgery), industrial equipment and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated processing chain environment, consumer electronic devices, devices operating on a commercial and / or industrial wireless network, etc. The terminal device may also correspond to the mobile terminal (MT) portion of an integrated access and backhaul (IAB) node. Relay node). In the following description, the terms “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably.

[0038] Although in various example embodiments, the functions described herein may be performed in fixed and / or wireless network nodes, in other example embodiments, the functions may be implemented in a user equipment device (such as a cellular phone or a tablet computer or a laptop computer or a desktop computer or a mobile device or a fixed device). The user equipment device may, for example, be appropriately equipped with the corresponding capabilities described in conjunction with the fixed and / or wireless network nodes. The user equipment device may be a user device and / or a control device, such as a chipset or a processor, which is configured to control the user device when installed therein. Examples of such functions include a bootstrap server function and / or a home user server, which may be implemented in a user equipment device by providing the user equipment device with software configured to cause the user equipment device to execute from the perspective of these functions / nodes.

[0039] Figure 1 1 shows an example communication network 100 in which embodiments of the present disclosure may be implemented. Figure 1As shown, the communication network 100 includes a terminal device 110-1 (hereinafter may also be referred to as a local UE 110-1 or a first device 110-1). The communication network 100 may include a COT provider 120 (hereinafter may also be referred to as a second device 120). The COT provider 120 may be considered as a base station, a road side unit (RSU) or a specific UE. The COT provider 120 may communicate with the terminal device 110-1.

[0040] The communication network 100 may also include terminal devices 110-2 and 110-3 (hereinafter may be referred to as other UEs 110-2 and 110-3). The terminal devices 110-1, 110-2 and 110-3 may communicate with each other. The COT provider 120 may also communicate with the terminal devices 110-2 and 110-3. It should be understood that the number of terminal devices and network devices is only for illustrative purposes and does not have any limitation. The communication network 100 may include any suitable number of terminal devices adapted to implement the embodiments of the present disclosure.

[0041] The communication network 100 can be implemented in a SL communication scenario. In SL communication, communication between terminal devices (e.g., V2V, V2P, V2I communication) can be performed via a side link. For SL communication, information can be sent from a transmitting (TX) terminal device to one or more receiving (RX) terminal devices in a broadcast, multicast, or unicast manner.

[0042] According to the communication technology, network 100 can be a code division multiple access (CDMA) network, a time division multiple access (TDMA) network, a frequency division multiple access (FDMA) network, an orthogonal frequency division multiple access (OFDMA) network, a single carrier frequency division multiple access (SC-FDMA) network or any other network. The communication discussed in network 100 can meet any suitable standard, including but not limited to new radio access (NR), long term evolution (LTE), LTE evolution, advanced LTE (LTE-A), wideband code division multiple access (WCDMA), code division multiple access (CDMA), cdma2000 and global system for mobile communications (GSM), etc. In addition, communication can be performed according to any generation of communication protocols currently known or to be developed in the future. Examples of communication protocols include but are 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. The technology described here can be used for the above-mentioned wireless networks and radio technologies as well as other wireless networks and radio technologies. For clarity, certain aspects of the techniques are described below for LTE, and LTE terminology is used in much of the description below.

[0043] Long Term Evolution - Unlicensed (LTE-U) and New Radio - Unlicensed (NR-U) for cellular access have been studied and standardized in the 3rd Generation Partnership Project (3GPP), where communication is performed between a UE and a serving base station (BS) over a UU interface in an unlicensed spectrum (U-spectRUm) or U-band. However, SL communication between UEs over a PC5 interface in the U-band has not been studied in 3GPP to date, but is expected to be used for, for example, Industrial Internet of Things (IIoT) support.

[0044] As described above, the Tx UE may use resources from a pre-configured resource pool to transmit at least an SCI to an Rx UE or a group of Rx UEs or all Rx UEs near the Tx UE, and the SCI is used as a scheduling assignment for SL data transmission. The Rx UE needs to keep monitoring on the pre-configured resource pool to receive SL transmissions, at least receive all SCI instances, and determine whether the received SCI and the corresponding SL data transmission are intended for the Rx UE to receive.

[0045] There are two resource allocation modes specified for SL transmission, namely Mode 1 (Mode 1) and Mode 2 (Mode 2). In Mode 1, the Tx UE may use resources scheduled or authorized from the serving BS. This means that the Tx UE may need to be in the RRC connected state of the serving BS in order to obtain Mode 1 allocated resources. In Mode 2, the Tx UE can autonomously allocate or select resources from a pre-configured Tx resource pool. Resource selection in Mode 2 can be performed based on random selection or sensing-based selection. Mode 2 can be used when the Tx UE is in coverage (IC) or out of coverage (Ooc); in RRC IDLE, RRCINACTIVE or RRC CONNECTED state.

[0046] In the sub-7 GHz unlicensed band (U-band), the coexistence of NR with other systems is ensured via a listen-before-talk (LBT) channel access mechanism. Therefore, a UE that wants to perform SL transmission in the U-band needs to first successfully complete the LBT check before initiating SL transmission.

[0047] In order to pass the LBT check, it should be determined whether the channel is available for a number of consecutive clear channel assessment (CCA) slots. In the sub-7GHz U-band, the duration of these slots is 9μs. If the measured power (i.e., the energy collected during the CCA slot) is below a specified threshold, the UE can determine that the channel is available in the CCA slot.

[0048] In unlicensed spectrum, there are two types of shared channel access mechanisms, namely load-based equipment (LBE) and frame-based equipment (FBE). For LBE, when a UE initiates communication, the UE can obtain the "right" to access the channel for a specific time period, which can be called the channel occupation time (COT), by applying an "extended" LBT process. In this "extended" LBT process, the channel can be considered idle for the entire duration of the contention window (CW). This "extended" LBT process is generally referred to as LBT Category 4 (LBT Cat.4) or LBT Type 1. The duration of the COT and CW depends on the channel access priority class (CAPC) associated with the UE service as shown below.

[0049] Table 1

[0050]

[0051]

[0052] If LBT Type 1 (LBT Cat.4) is completed successfully, the UE can perform the transmission and obtain a COT with a duration associated with the corresponding CAPC. The obtained COT is valid even if the initiating device suspends its transmission. If the initiating device wants to perform a new transmission (within the COT), it still needs to perform a "reduced" LBT procedure. This "reduced" LBT procedure is generally referred to as LBT Category 2 (LBT Cat.2) or LBT Category 1 (LBT Cat.1), which may also be referred to as LBT Type 2. LBT Type 2 may refer to different variants, such as LBT Type 2A, LBT Type 2B and LBT Type 2C.

[0053] The initiating device may share its acquired COT with its receiving devices (responding devices). For this purpose, the initiating device must explicitly (i.e., via control signaling) inform the responding device about the duration of the COT. The responding device can use this information to determine which category / type of LBT should be applied to perform the transmission to the initiating device. In the event that the transmission from the responding device falls outside the COT or the responding device wants to perform a transmission to a device other than the initiating device, the responding device may have to acquire a new COT using LBT Type 1 (LBT Directory 4) with an appropriate CAPC.

[0054] In FBE, the channel access process is different from that of LBE. In FBE, the UUT (unit under test) performs LBT to acquire the channel for COT during the Clear Channel Assessment (CCA) interval of each fixed frame period in the range of 1ms to 10ms. COT can occupy 95% of the fixed frame period while maintaining the idle period for at least 100us. In the case that LBT in CCA finds that the channel is occupied, there is no transmission on the channel during the next fixed frame period.

[0055] For continuous transmissions during a COT that do not require an LBT process, the gap between two transmissions should be less than 16 μs. In the case where the gap exceeds 16 us, if the additional LBT does not detect a wireless local area network (RLAN) transmission with a level above a predetermined threshold, the transmitting device can continue to transmit in this COT. Additional LBT is performed immediately before the transmission, in the gap and in the observation time slot, which can be counted within the current COT.

[0056] Furthermore, in FBE, a responding device may be allowed to send feedback, such as an ACK, to received packets within the current COT without performing additional LBT, whereas in LBE, the responding device may have to perform LBT before accessing the channel to send feedback (depending on the timing of the transmission from the initiating device and the timing of the feedback from the responding device).

[0057] It is considered that a resource pool in the U band (which may be referred to as a U pool) and a resource pool in the L band (which may be referred to as an L pool) may be configured by a serving network device to a UE for SL communication.

[0058] The use of the U-pool for SL communication of neighboring UEs relies on LBT for CCA to obtain the COT. The COT provider can obtain the COT and share the COT with other neighboring devices to send SL communications within the acquired COT without or reducing the need to perform LBT. SL communication is in principle a broadcast-based proximity communication on a preconfigured U-pool that is common to all local UEs, and local UEs in mode 2 may need to perform sensing on the U-pool. It is not desirable to require an LBT process on the U-pool, which will affect the sensing process. Therefore, the above-mentioned COT sharing is applicable to SL communications in the local service area of ​​the target IIoT system.

[0059] Therefore, the present disclosure provides a solution for COT in the U band for SL communication. In this solution, a local UE can receive a COT configuration from a COT provider. The COT configuration can at least indicate whether the local UE is required to perform a listen-before-talk process within the COT before the SL transmission of the local UE. Then, the local UE can perform SL transmission based on the COT configuration within the duration of the COT.

[0060] The following will refer to Figure 2 Describe the principles and implementation of the present disclosure in detail. Figure 2 FIG. 4 shows a schematic process of COT for SL communication in U band. For the purpose of discussion, reference will be made to Figure 1 Process 200 is described. Process 200 may include the following: Figure 1 A local UE 110 - 1 and a COT provider 120 are shown.

[0061] like Figure 2 As shown, in the case where the COT provider 120 can be considered as a serving base station, the COT provider 120 can first send an indication of resource allocation of the U pool and the associated L pool and a measurement configuration for reporting a channel busy ratio (CBR), etc. to the local UE 110-1. In addition, the COT provider 120 can also send 202 configuration information to the local UE 110-1 for monitoring a signal indicating a COT configuration, detecting a gap within the COT, or sending another signal occupying the COT.

[0062] As another option, in the case where the COT provider 120 can be considered as another local UE, e.g. Figure 1 The illustrated UE 110 - 2 or 110 - 3 , the COT provider 120 , and the local UE 110 - 1 may all receive configuration information from the serving base station for monitoring a signal indicating a COT configuration, detecting a gap within the COT, or transmitting another signal to occupy the COT.

[0063] In some example embodiments, the local UE may be configured to monitor a signal indicating a COT configuration at a preconfigured timing and / or resource (e.g., time / frequency / code / space domain), and if a signal indicating a COT configuration is received, determine whether the U pool is to be used for SL transmission. In some example embodiments, the local UE may also be configured to maintain or skip monitoring of the U pool for SL reception when a signal indicating a COT configuration is not received.

[0064] After receiving the above configuration information and instructions, the local UE 110 - 1 may perform, for example, measurement of the CBR based on the received information, and transmit 204 a measurement report to the COT provider 120 .

[0065] Then, the COT provider 120 may acquire the COT for SL transmission, for example, by performing the LBT process. If the LBT process is successfully performed, the COT provider 120 acquires the COT.

[0066] In some example embodiments, for example, in a semi-static option (FBE), a fixed frame period and / or a fixed COT duration may be pre-configured to the COT provider and the local UE together with a configuration related to the U-pool, and / or SL synchronization for the U-pool, and / or a time period and resources for transmitting a signal indicating the COT configuration. For example, a fixed frame period of 10 ms and a fixed COT duration of 10 ms minus a predefined OFFSET (covering idle periods including CCA periods) may be pre-configured to the COT provider and the local UE. In another example, the fixed frame period and the fixed COT duration may be derived from the received configuration of the U-pool.

[0067] In some exemplary embodiments, for example, in a dynamic option (LBE), the COT provider may determine the COT duration after acquiring the COT of the U-pool based on the measured load or measurement report of the CBR of the local SL communication on the configured U-pool and / or the associated L-pool. The associated L-pool may be pre-configured to the COT provider and the local UE in parallel with the U-pool, because the use of the U-pool is opportunistic, which may depend on whether the COT is acquired on the U-band.

[0068] After obtaining the COT, the COT provider 120 may determine 206 a COT configuration for the obtained COT. The COT configuration may indicate a suitable COT on the U band for possible SL communications to and between local UEs including the local UE 110-1 using the configured U pool. For example, the COT configuration may indicate a duration of the COT. In addition, the COT configuration may also indicate whether the local UE 110-1 needs to perform an additional LBT procedure for CCA within the obtained COT immediately prior to SL transmission.

[0069] After determining the COT configuration, the COT provider 120 may send 208 the COT configuration to the local UE 110-1 via, for example, a first signal.

[0070] It should be understood that the COT provider 120 may also send the COT configuration to other UEs for their SL transmissions, for example, Figure 1 UEs 110-2 and 110-3 are shown.

[0071] In some example embodiments, the first signal indicating the COT configuration may be periodically transmitted at each configured time interval within the acquired COT using pre-configured resources in the U band or in the L band or in both the U band and the L band. The transmission of the first signal at each configured time interval may be adjusted according to the duration of the COT.

[0072] In some example embodiments, the COT configuration may also indicate the remaining duration of the COT. For example, if the first signal is transmitted after the COT is initiated, the remaining duration may be the time interval between the time point when the first signal is transmitted and the end of the duration of the COT.

[0073] In some example embodiments, the first signal may be a layer 1 (L1) signal or a layer 1 message or a higher layer message sent through a PC5 or UU interface.

[0074] After receiving the first signal indicating the COT configuration, the local UE 110-1 may determine 210 whether it is necessary to perform an LBT procedure within a channel occupancy time prior to a sidelink transmission of the local UE 110-1.

[0075] If the COT configuration indicates that an LBT process needs to be performed within the channel occupancy time before the sidelink transmission of the local UE 110-1, the local UE 110-1 can determine whether a time interval is detected before the SL transmission within the COT, during which no SL transmission or other signals such as the first signal are scheduled on the U pool or U band. For example, the time interval can be referred to as a gap within the COT. The gap may include a preconfigured duration, such as a gap greater than 16 μs. The detection of the gap before the SL transmission can be performed by the local UE 110-1 based on the sidelink control information (SCI) or other signals received from other local UEs or COT providers, for example, on the U pool or U band.

[0076] If the local UE 110-1 determines that such a gap is detected before the SL transmission within the COT, the local UE 110-1 may perform an LBT procedure before the SL transmission within the COT. If the LBT procedure is successfully performed, the local UE 110-1 may perform the SL transmission.

[0077] If the local UE 110 - 1 determines that such a gap is not detected before the SL transmission within the COT, the local UE 110 - 1 may perform the SL transmission by skipping the LBT procedure.

[0078] If the COT configuration indicates that the LBT process does not need to be performed within the channel occupancy time before the sidelink transmission of the local UE 110-1, the local UE 110-1 can perform SL transmission within the COT by skipping the LBT process. The local UE 110-1 may also be configured to determine whether a time interval is detected within the COT during which no SL transmission or other signal such as the first signal is scheduled on the U pool or U band. For example, the time interval may be referred to as a gap within the COT. The gap may include a preconfigured duration, such as a gap greater than 16 μs. For example, detection of the gap may be performed based on the sidelink control information (SCI) of the local UE 110-1 and also based on the SCI or other signals received from other local UEs or COT providers on the U pool or U band.

[0079] As an option, if the local UE 110 - 1 determines that such a gap is detected within the COT, the local UE 110 - 1 may be triggered 212 to send a second signal to the COT provider 120 occupying the gap.

[0080] As another option, if local UE 110-1 determines that such a gap is detected within the COT, local UE 110-1 may transmit 214 an indication of the gap to COT provider 120. Alternatively, UE 110-1 may also transmit a gap indication to a specific UE. COT provider 120 or a specific UE may also be configured to detect the gap and send a second signal occupying the gap.

[0081] In some example embodiments, when the COT configuration indicates that the LBT process does not need to be performed during the channel occupancy time before the sidelink transmission of the local UE 110-1, the local UE 110-1 may not need to detect the gap. In this case, the COT provider 120 or the specific local UE may be configured to send a second signal occupying the COT for the entire duration of the COT. Then, the local UE 110-1 can perform SL transmission within the COT on the U pool by skipping the LBT process. The local UE 110-1 may select a resource on the frequency domain for SL transmission that is different from the resource on the frequency domain used to transmit the second signal.

[0082] In some example embodiments, the second signal may be a preconfigured L1 signal or L1 message or a higher layer message.The second signal may indicate the same or different information as the first signal.

[0083] In some example embodiments, where the second signal is in the form of a preconfigured L1 signal, the second signal may be continuously transmitted by the COT provider and / or one or more local UEs using preconfigured resources on the U band to fill the detected gaps.

[0084] In some example embodiments, where the second signal is in the form of a preconfigured higher layer SL message, the second signal may be transmitted by the COT provider and / or one or more local UEs using preconfigured or dynamically allocated resources from the U pool to fill the detected gap.

[0085] Figure 3A and 3B An example of sending a signal for maintaining COT according to some example embodiments of the present disclosure is shown. Figure 3A As shown, in COT 310, a first signal 311 indicating COT configuration may be sent in time interval 301. Time intervals 302, 303, and 304 may be occupied by SL transmissions of local UEs. Potential gaps 320, for example, greater than 16 μs, may be detected. As described above, a second signal 312 occupying the COT may be transmitted by the COT provider, local UE 110-1, or other specific UE during the gap.

[0086] like Figure 3B As shown, in COT 310, a first signal 311 indicating COT configuration may be transmitted in time interval 301. Time intervals 302, 303, and 304 may be occupied by SL transmissions of local UEs. A second signal 312 occupying the COT may be transmitted by the COT provider or other specific UE over the entire duration of the COT. The second signal may occupy a narrowband in the U band. In this case, gap detection is not required.

[0087] In some example embodiments, taking into account the possibility that the local UE can receive from more than one COT provider, the local UE can be configured to select a COT provider based on the method applied to cell selection and reselection when the COT provider is a serving BS candidate, or the selection and reselection of the SL synchronization source when the COT provider is the selected UE. Therefore, the most relevant criteria between the local UE and each COT provider in terms of group relationship or user group, such as best received signal strength, shortest distance, longest COT, etc., can be used to select the COT provider. Note that coordination between COT providers can also be considered for providing a unified COT when serving the IIoT system over a restricted service area as in the target use case.

[0088] In this way, the COT sharing mechanism can be used for SL communication in the U band, so the sensing process for resource selection will not be affected by the LBT process.

[0089] Figure 4 FIG. 4 is a flow chart showing an example method 400 for COT sharing for SL communication in U-band according to some example embodiments of the present disclosure. The method 400 may be implemented in a manner such as Figure 1 For the purpose of discussion, reference will be made to Figure 1 Method 400 is described.

[0090] At 410, the first device receives configuration information associated with a channel occupancy time from the second device, the channel occupancy time being used for at least a sidelink transmission of the first device on an unlicensed resource pool allocated for the first device. The configuration information may at least indicate whether a listen-before-talk procedure needs to be performed at the first device during the channel occupancy time before the sidelink transmission; and performing the sidelink transmission during the channel occupancy time based on the configuration information.

[0091] In some example embodiments, the first device may periodically receive configuration information.

[0092] In some example embodiments, the configuration information may include at least one of a duration of the channel occupancy time and a remaining duration of the channel occupancy time, the remaining duration starting from a time point when the configuration information is received to an end of the channel occupancy time, and the remaining duration starting from a time point when the side link transmission starts to an end of the channel occupancy time.

[0093] In some example embodiments, the first device may receive the configuration information via a physical layer signal, a physical layer message, or a higher layer message.

[0094] At 420, the first device performs sidelink transmission within the channel occupancy time based on the configuration information.

[0095] In some example embodiments, if the first device determines based on the configuration information that a listen-before-talk procedure is needed, the first device may determine, prior to the sidelink transmission of the first device, based at least on the received sidelink control information, whether a time interval having a duration exceeding a threshold duration is detected within the channel occupancy time, during which neither the sidelink transmission nor a signal to be transmitted for indicating or occupying the channel occupancy time is scheduled. If the first device determines that the time interval is detected within the channel occupancy time prior to the sidelink transmission, the first device may determine to perform the listen-before-talk procedure prior to the sidelink transmission. If the listen-before-talk procedure is successful, the first device may perform the sidelink transmission.

[0096] In some example embodiments, if the first device determines that the time interval is not detected within the channel occupancy time before the sidelink transmission, the first device may perform the sidelink transmission by skipping the listen-before-talk procedure.

[0097] In some example embodiments, if the first device determines that the listen-before-talk procedure is not required based on the configuration information, the first device may perform sidelink transmission by skipping the listen-before-talk procedure.

[0098] In some example embodiments, if the first device determines based on the configuration information that the listen-before-talk process is not required, the first device may determine, based at least on the received sidelink control information, whether a time interval having a duration exceeding a threshold duration is detected within the channel occupancy time, during which neither a sidelink transmission is scheduled nor a signal to be transmitted for indicating or occupying the scheduled channel occupancy time is scheduled. If the first device determines that the time interval is detected within the channel occupancy time, the first device may transmit a signal for occupying the channel occupancy time during the time interval.

[0099] In some example embodiments, if the first device determines based on the configuration information that the listen-before-talk process is not required, the first device may determine, based at least on the received sidelink control information, whether a time interval having a duration exceeding a threshold duration is detected within the channel occupancy time, during which time interval neither a sidelink transmission is scheduled nor a signal to be transmitted indicating or occupying the scheduled channel occupancy time is scheduled. If the first device determines that the time interval is detected within the channel occupancy time, the first device may send an indication of the time interval to the second device so that the second device transmits a signal occupying the channel occupancy time during the time interval.

[0100] Figure 5 1 shows a flow chart of an example method 500 for COT sharing for SL communication in U band according to some example embodiments of the present disclosure. The method 500 may be performed in the second device 120 or in the example Figure 1 For the purpose of discussion, reference will be made to Figure 1 Method 500 is described.

[0101] At 510, the second device determines a channel occupancy time for at least a sidelink transmission of the first device on an unlicensed resource pool allocated for the first device.

[0102] At 520, the second device generates configuration information associated with the channel occupancy time, the configuration information indicating at least whether a listen-before-talk procedure needs to be performed at the first device within the channel occupancy time prior to sidelink transmission.

[0103] At 530 , the second device sends configuration information to the first device.

[0104] In some example embodiments, the second device may periodically send the configuration information.

[0105] In some example embodiments, the second device may transmit at least one of a duration of the channel occupancy time and a remaining duration of the channel occupancy time in the configuration information, the remaining duration starting from a time point when the configuration information is received to an end of the channel occupancy time, and the remaining duration starting from a time point when the side link transmission starts to an end of the channel occupancy time.

[0106] In some example embodiments, the second device may send the configuration information via a physical layer signal or a physical layer message or a higher layer message.

[0107] In some example embodiments, if the second device determines that a listen-before-talk procedure is not required at the first device during the channel occupancy time prior to the sidelink transmission, the second device may send a signal to occupy the channel occupancy time for the duration of the channel occupancy time.

[0108] In some example embodiments, if the second device receives an indication of a time interval from the first device, the second device may transmit a signal occupying the channel occupancy time during a time interval within the channel occupancy time, wherein during the time interval neither a side link transmission is scheduled nor a signal to be sent indicating or occupying the scheduled channel occupancy time is scheduled.

[0109] In some example embodiments, if the second device determines that a listen-before-talk procedure does not need to be performed at the first device during the channel occupancy time prior to the sidelink transmission, the second device may determine whether a time interval having a duration exceeding a threshold duration is detected during the channel occupancy time, wherein neither the sidelink transmission nor a signal to be transmitted indicating or occupying the channel occupancy time is scheduled during the time interval. If the second device determines that the time interval is detected, the second device may transmit a signal occupying the channel occupancy time during the time interval.

[0110] In some example embodiments, an apparatus capable of performing method 400 (e.g., implemented at first device 110-1) may include components for performing the various steps of method 400. The components may be implemented in any suitable form. For example, the components may be implemented in a circuit or a software module.

[0111] In some example embodiments, the apparatus includes a module for receiving, at a first device and from a second device, configuration information associated with a COT, the COT being at least used for SL transmission of the first device on an unauthorized resource pool allocated for the first device, the configuration information at least indicating whether a listen-before-talk process is required to be performed at the first device within the COT before the SL transmission; and an apparatus for performing the SL transmission within the COT based on the configuration information.

[0112] In some example embodiments, an apparatus capable of performing method 500 (e.g., implemented at second device 120) may include components for performing the various steps of method 500. The components may be implemented in any suitable form. For example, the components may be implemented in a circuit or a software module.

[0113] In some example embodiments, the apparatus includes a component for determining a COT, a channel occupancy time being at least used for a side link transmission of a first device on an unlicensed resource pool allocated for the first device; a component for generating configuration information associated with the COT, the configuration information at least indicating whether a listen-before-talk process is required to be performed at the first device within the channel occupancy time COT before transmission of the side link SL; and an apparatus for transmitting the configuration information to the first device.

[0114] Figure 6 600 is a simplified block diagram of a device 600 suitable for implementing embodiments of the present disclosure. The device 600 may be provided to implement a communication device, such as Figure 1 The UE 110 - 1 or COT provider 120 is shown. As shown, the device 600 includes one or more processors 610 , one or more memories 620 coupled to the processors 610 , and one or more transmitters and receivers (TX / RX) 640 coupled to the processors 610 .

[0115] The TX / RX 640 is used for bidirectional communication. The TX / RX 640 has at least one antenna to facilitate communication. The communication interface may represent any interface required to communicate with other network elements.

[0116] Processor 610 may be of any type suitable for the local technology network and may include one or more of the following: as non-limiting examples, a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. Device 600 may have multiple processors, such as application specific integrated circuit chips that are time slaved to a clock that synchronizes a main processor.

[0117] The memory 620 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include (but are not limited to) read-only memory (ROM) 624, electrically programmable read-only memory (EPROM), flash memory, hard disk, compact disk (CD), digital video disk (DVD), and other magnetic storage devices and / or optical storage devices. Examples of volatile memories include, but are not limited to, random access memory (RAM) 622 and other volatile memories that do not persist over the duration of a power outage.

[0118] Computer program 630 includes computer executable instructions executed by associated processor 610. Program 630 may be stored in ROM 620. Processor 610 may perform any suitable actions and processes by loading program 630 into RAM 620.

[0119] The embodiments of the present disclosure can be implemented by means of program 630, so that the device 600 can execute the following steps: Figure 2-5 Any process of the present disclosure discussed. The embodiments of the present disclosure may also be implemented by hardware or a combination of software and hardware.

[0120] In some embodiments, the program 630 may be tangibly contained in a computer-readable medium, which may be included in the device 600 (e.g., in the memory 620) or in other storage devices accessible by the device 600. The device 600 may load the program 630 from the computer-readable medium to the RAM 622 for execution. The computer-readable medium may include any type of tangible non-volatile memory, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. Figure 7 An example of a computer readable medium 700 in the form of a CD or DVD is shown. The computer readable medium has a program 630 stored thereon.

[0121] In general, various embodiments of the present disclosure may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software, which may be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of the present disclosure are shown and described as block diagrams, flow charts, or using some other graphical representations, it should be understood that the blocks, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general hardware or controllers or other computing devices, or some combination thereof, as non-limiting examples.

[0122] The present 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 a program module that are executed in a device on a target real or virtual processor to perform the above-referenced Figure 4-5 Methods 400 and 500 are described. In general, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The functions of program modules can be combined or separated between program modules as needed in various embodiments. The machine executable instructions of program modules can be executed in local or distributed devices. In distributed devices, program modules can be located in local and remote storage media.

[0123] The program code for executing the method of the present disclosure can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing device so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code can be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine, partially on a remote machine, or entirely on a remote machine or server.

[0124] In the context of the present disclosure, computer program codes or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform various processes and operations as described above. Examples of carriers include signals, computer readable media, etc.

[0125] The computer readable medium may be a computer readable signal medium or a computer readable storage medium. The computer readable medium may include, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared or semiconductor system, device or apparatus, or any suitable combination of the foregoing. More specific examples of computer readable storage media would include an electrical connection having one or more conductors, a portable computer disk, 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 disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0126] In addition, although operations are described in a particular order, this should not be understood as requiring the specific order shown or to perform these operations in sequence, or to perform all the operations shown, to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these details should not be interpreted as limitations on the scope of the present disclosure, but should be interpreted as descriptions of features peculiar to a particular embodiment. Certain features described in the context of a separate embodiment may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable sub-combination.

[0127] Although the disclosure has been described in language specific to structural features and / or methodological actions, it should be understood that the disclosure defined in the appended claims is not necessarily limited to the specific features or actions described above. Instead, the specific features and actions described above are disclosed as example forms of implementing the claims.

Claims

1. A first device, comprising: at least one processor; as well as at least one memory including computer program code; The at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to at least: periodically receiving configuration information associated with a channel occupancy time from a second device, the channel occupancy time being used at least for a sidelink transmission of the first device on an unlicensed resource pool allocated for the first device, the configuration information at least indicating whether a listen-before-talk procedure needs to be performed at the first device within the channel occupancy time before the sidelink transmission; as well as performing the side link transmission during the channel occupancy time based on the configuration information; The first device is further configured to: In accordance with determining that the listen-before-talk procedure is not needed based on the configuration information, determining based at least on the received sidelink control information: whether a time interval having a duration exceeding a threshold duration is detected within the channel occupancy time, wherein during the time interval neither a sidelink transmission is scheduled nor a signal to be transmitted for indicating or occupying the channel occupancy time is scheduled; as well as Based on determining that the time interval is detected within the channel occupation time, a signal for occupying the channel occupation time is sent during the time interval.

2. The first device according to claim 1, wherein the configuration information comprises at least one of the following: the duration of the channel occupancy time, a remaining duration of the channel occupation time, the remaining duration starting from the time point when the configuration information is received to the end of the channel occupation time, and The remaining duration of the channel occupancy time, the remaining duration starting from the time point when the sidelink transmission starts to the end of the channel occupancy time.

3. The first device of claim 1 , wherein the first device is caused to receive the configuration information by: The configuration information is received via at least one of the following: Physical layer messages, Physical layer signals, and Higher level message.

4. The first device of claim 1 , wherein the first device is caused to perform the sidelink transmission by: In accordance with determining that the listen-before-talk procedure is needed based on the configuration information, determining based at least on the received sidelink control information: whether a time interval having a duration exceeding a threshold duration is detected within the channel occupancy time prior to the sidelink transmission of the first device, wherein neither a sidelink transmission nor a signal to be transmitted for indicating or occupying the channel occupancy time is scheduled during the time interval; and performing the listen-before-talk procedure prior to the sidelink transmission based on determining that the time interval is detected within the channel occupancy time prior to the sidelink transmission, and Based on determining that the listen-before-talk process is successful, performing the sidelink transmission.

5. The first device according to claim 4, wherein the first device is further configured to: The sidelink transmission is performed by skipping the listen-before-talk procedure based on determining that the time interval is not detected within the channel occupancy time before the sidelink transmission.

6. The first device according to claim 1, wherein the first device is further configured to: In accordance with determining that the listen-before-talk procedure is not needed based on the configuration information, determining based at least on the received sidelink control information: whether a time interval having a duration exceeding a threshold duration is detected within the channel occupancy time, wherein during the time interval neither a sidelink transmission nor a signal to be transmitted indicating or occupying the channel occupancy time is scheduled; and Based on determining that the time interval is detected within the channel occupation time, an indication of the time interval is sent to the second device so that the second device sends a signal occupying the channel occupation time during the time interval.

7. A second device, comprising: at least one processor; as well as at least one memory including computer program code; The at least one memory and the computer program code are configured to, with the at least one processor, cause the second device to at least: determining a channel occupancy time, the channel occupancy time being used at least for sidelink transmission of the first device on an unlicensed resource pool allocated for the first device; generating configuration information associated with the channel occupancy time, the configuration information at least indicating whether a listen-before-talk process needs to be performed at the first device within the channel occupancy time before the sidelink transmission; as well as periodically sending the configuration information to the first device; The second device is further configured to: determining, based on determining that the listen-before-talk procedure need not be performed at the first device during the channel occupied time prior to the sidelink transmission, whether a time interval having a duration exceeding a threshold duration is detected during the channel occupied time, wherein neither a sidelink transmission nor a signal to be transmitted indicating or occupying the channel occupied time is scheduled during the time interval; Based on determining that the time interval is detected, a signal occupying the channel occupation time is transmitted during the time interval.

8. The second device according to claim 7, wherein the configuration information comprises at least one of the following: the duration of the channel occupancy time, a remaining duration of the channel occupation time, the remaining duration starting from the time point when the configuration information is received to the end of the channel occupation time, and The remaining duration of the channel occupancy time, the remaining duration starting from the time point when the sidelink transmission starts to the end of the channel occupancy time.

9. The second device according to claim 7, wherein the second device is caused to send the configuration information by: The configuration information is sent via at least one of the following: Physical layer messages, Physical layer signals, and Higher level message.

10. The second device according to claim 7, wherein the second device is further caused to: Based on determining that, prior to the sidelink transmission, it is not necessary to perform the listen-before-talk process at the first device during the channel occupation time, a signal for occupying the channel occupation time is sent for a duration of the channel occupation time.

11. The second device according to claim 7, wherein the second device is further configured to: Based on determining that an indication of a time interval is received, a signal occupying the channel occupancy time is sent during the time interval within the channel occupancy time, wherein during the time interval neither a side link transmission is scheduled nor a signal to be sent indicating or occupying the channel occupancy time is scheduled.

12. A method comprising: Periodically receiving, at a first device, configuration information associated with a channel occupancy time from a second device, the channel occupancy time being used at least for a sidelink transmission of the first device on an unlicensed resource pool allocated for the first device, the configuration information at least indicating whether a listen-before-talk procedure needs to be performed at the first device during the channel occupancy time before the sidelink transmission; as well as performing the side link transmission during the channel occupancy time based on the configuration information; The method further comprises: In accordance with determining that the listen-before-talk procedure is not needed based on the configuration information, determining based on the sidelink control information: whether a time interval having a duration exceeding a threshold duration is detected within the channel occupied time, wherein during the time interval neither a sidelink transmission is scheduled nor a signal to be transmitted for indicating or occupying the channel occupied time is scheduled; as well as Based on determining that the time interval is detected within the channel occupation time, a signal for occupying the channel occupation time is sent during the time interval.

13. The method according to claim 12, wherein the configuration information comprises at least one of the following: the duration of the channel occupancy time, and a remaining duration of the channel occupation time, the remaining duration starting from the time point when the configuration information is received to the end of the channel occupation time, and The remaining duration of the channel occupancy time, the remaining duration starting from the time point when the sidelink transmission starts to the end of the channel occupancy time.

14. The method of claim 12, wherein receiving the configuration information comprises: The configuration information is received via at least one of the following: Physical layer messages, Physical layer signals, and Higher level message.

15. The method of claim 12, wherein performing the sidelink transmission comprises: In accordance with determining that the listen-before-talk procedure is needed based on the configuration information, determining based at least on the received sidelink control information: whether a time interval having a duration exceeding a threshold duration is detected within the channel occupancy time prior to the sidelink transmission of the first device, wherein neither a sidelink transmission nor a signal to be transmitted for indicating or occupying the channel occupancy time is scheduled during the time interval; as well as performing the listen-before-talk procedure prior to the sidelink transmission based on determining that the time interval is detected within the channel occupancy time prior to the sidelink transmission, and Based on determining that the listen-before-talk process is successful, performing the sidelink transmission.

16. The method according to claim 15, further comprising: The sidelink transmission is performed by skipping the listen-before-talk procedure based on determining that the time interval is not detected within the channel occupancy time before the sidelink transmission.

17. The method according to claim 12, further comprising: In accordance with determining that the listen-before-talk procedure is not needed based on the configuration information, determining based on the sidelink control information: whether a time interval having a duration exceeding a threshold duration is detected within the channel occupied time, wherein during the time interval neither a sidelink transmission is scheduled nor a signal to be transmitted for indicating or occupying the channel occupied time is scheduled; as well as Based on determining that the time interval is detected within the channel occupation time, an indication of the time interval is sent to the second device so that the second device sends a signal occupying the channel occupation time during the time interval.

18. A method comprising: determining, at the second device, a channel occupancy time for at least a sidelink transmission of the first device on an unlicensed resource pool allocated for the first device; generating configuration information associated with the channel occupancy time, the configuration information at least indicating whether a listen-before-talk process needs to be performed at the first device within the channel occupancy time before the sidelink transmission; as well as periodically sending the configuration information to the first device; The method further comprises: determining, based on determining that the listen-before-talk procedure need not be performed at the first device during the channel occupied time prior to the sidelink transmission, whether a time interval having a duration exceeding a threshold duration is detected during the channel occupied time, wherein neither a sidelink transmission nor a signal to be transmitted indicating or occupying the channel occupied time is scheduled during the time interval; Based on determining that the time interval is detected, a signal occupying the channel occupation time is transmitted during the time interval.

19. The method according to claim 18, wherein the configuration information comprises at least one of the following: the duration of the channel occupancy time, and a remaining duration of the channel occupation time, the remaining duration starting from the time point when the configuration information is received to the end of the channel occupation time, and The remaining duration of the channel occupancy time, the remaining duration starting from the time point when the sidelink transmission starts to the end of the channel occupancy time.

20. The method of claim 18, wherein sending the configuration information comprises: The configuration information is sent via at least one of the following: Physical layer messages, Physical layer signals, and Higher level message.

21. The method of claim 18, further comprising: Based on determining that, prior to the sidelink transmission, it is not necessary to perform the listen-before-talk process at the first device during the channel occupation time, a signal for occupying the channel occupation time is sent for a duration of the channel occupation time.

22. The method of claim 18, further comprising: Based on determining that an indication of a time interval is received, a signal occupying the channel occupancy time is sent during the time interval within the channel occupancy time, wherein during the time interval neither a side link transmission is scheduled nor a signal to be sent indicating or occupying the channel occupancy time is scheduled.

23. An apparatus comprising: means for periodically receiving, at a first device, configuration information associated with a COT from a second device, the COT being used at least for SL transmission of the first device on an unlicensed resource pool allocated for the first device, the configuration information at least indicating whether a listen-before-talk procedure needs to be performed at the first device within the COT before the SL transmission; means for performing the SL transmission within the COT based on the configuration information; means for determining, based on determining that the listen-before-talk procedure is not needed based on the configuration information, at least based on the received sidelink control information: whether a time interval having a duration exceeding a threshold duration is detected within the channel occupancy time, wherein during the time interval neither a sidelink transmission is scheduled nor a signal to be transmitted for indicating or occupying the channel occupancy time is scheduled; as well as means for transmitting a signal for occupying the channel occupancy time during the time interval based on determining that the time interval is detected within the channel occupancy time.

24. An apparatus comprising: means for determining a channel occupancy time for at least a sidelink transmission of the first device on a pool of unlicensed resources allocated for the first device; means for generating configuration information associated with the COT, the configuration information indicating at least whether a listen-before-talk procedure needs to be performed at the first device within the COT before the sidelink SL transmission; A component for periodically sending the configuration information to the first device; means for determining, based on determining that the listen-before-talk procedure need not be performed at the first device within the channel occupied time prior to the sidelink transmission, whether a time interval having a duration exceeding a threshold duration is detected within the channel occupied time, wherein neither a sidelink transmission nor a signal to be transmitted indicating or occupying the channel occupied time is scheduled during the time interval; as well as means for transmitting a signal occupying the channel occupation time during the time interval in response to determining that the time interval is detected.

25. A non-transitory computer-readable medium comprising program instructions, wherein the program instructions are used to cause an apparatus to at least perform the method according to any one of claims 12-17.

26. A non-transitory computer-readable medium comprising program instructions, wherein the program instructions are used to cause an apparatus to at least perform the method according to any one of claims 18-22.

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