Channel Occupancy Time Sharing Mechanism

Abstract

According to an embodiment of the present disclosure, a first device determines one or more second devices with which it will share a channel occupation time (COT) for sidelink transmission over an unlicensed spectrum band. The first device transmits information indicating the COT shared by the first device and the one or more second devices. The second device determines a transmission gap within the COT and performs LBT / CCA on the unlicensed spectrum band based on the determined gap. In this way, sharing of the COT between the SL devices is realized. This can improve spectrum efficiency and avoid resource waste.

Description

[Technical Field]

[0001] FIELD Embodiments of the present disclosure relate generally to the field of telecommunications, and more particularly to methods, devices, apparatus, and computer-readable storage media for sharing channel occupation time (COT). [Background technology]

[0002] With the development of communication technology, various communication scenarios have been proposed. For example, sidelink communication has been proposed. Sidelink is a special communication mechanism that is performed between devices without the intervention of a network device. This "sidelink" technology can be applied to various scenarios, such as vehicle-to-vehicle (V2V) and vehicle-to-everything (V2X). Generally, before performing sidelink communication in an unlicensed frequency band, a device may perform clear channel assessment (CCA) in the unlicensed frequency band to determine that the unlicensed frequency band is not occupied by other devices. If the CCA is successful, the device can access the channel for a certain period of time, expressed as "channel occupation time (COT)." Summary of the Invention

[0003] Generally, the exemplary embodiments of the present disclosure provide a solution for sharing channel occupancy time.

[0004] In a first aspect, a first device is provided, the first device comprising: at least one processor; and at least one memory including computer program code configured, by the at least one processor, to cause the first device to: determine one or more second devices with which to share a channel occupation time for sidelink transmissions using an unlicensed spectrum; and transmit, at the first device, information indicating the channel occupation time shared by the first device and the determined one or more second devices.

[0005] In a second aspect, a second device is provided, the second device comprising at least one processor and at least one memory containing computer program code configured, by the at least one processor, to cause the second device to: receive, from the first device, information indicating a channel occupation time shared by the first device and the second device, determine a transmission gap within the channel occupation time based at least in part on sidelink transmissions from the first device, and perform listen-before-talk in the unlicensed spectrum band based on the determined gap.

[0006] In a third aspect, a method is provided that includes: determining, at a first device, one or more second devices with which to share a channel occupation time for sidelink transmissions using an unlicensed spectrum band; and transmitting, at the first device, information indicating the channel occupation time shared by the first device and the determined one or more second devices.

[0007] In a fourth aspect, a method is provided, at a second device, including receiving, from a first device, information indicating a channel occupation time shared by the first device and the second device, determining a transmission gap within the channel occupation time based at least in part on sidelink transmissions from the first device, and performing listen-before-talk in an unlicensed spectrum band based on the determined gap.

[0008] In a fifth aspect, an apparatus is provided, comprising: means, in a first device, for determining one or more second devices with which to share a channel occupation time for sidelink transmissions using an unlicensed spectrum band; and means, in the first device, for transmitting information indicating the channel occupation time shared by the first device and the determined one or more second devices.

[0009] In a sixth aspect, an apparatus is provided, comprising: means, at a second device, for receiving, from a first device, information indicating a channel occupation time shared by the first device and the second device, means for determining a transmission gap within the channel occupation time based at least in part on sidelink transmissions from the first device, and means for performing listen-before-talk in an unlicensed spectrum band based on the determined gap.

[0010] In a seventh aspect, there is provided a computer-readable medium comprising program instructions for causing an apparatus to perform at least a method according to any one of the fourth, fifth or sixth aspects above.

[0011] It should be understood that this summary is not intended to identify key features or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become more readily apparent through the following description. [Brief explanation of the drawings]

[0012] Some exemplary embodiments will now be described with reference to the accompanying drawings. [Figure 1] FIG. 1 shows a schematic diagram of a prior art COT. [Figure 2A] FIG. 2A shows a schematic diagram of a transmission gap during a COT according to the prior art. [Figure 2B] FIG. 2B shows a schematic diagram of a transmission gap during a COT according to the prior art. [Figure 3] FIG. 3 illustrates an exemplary communication environment in which exemplary embodiments of the present disclosure may be implemented. [Figure 4] FIG. 4 is a diagram illustrating a signal flow for sharing a COT according to some exemplary embodiments of the present disclosure. [Figure 5] FIG. 5 shows a schematic diagram of a gap during a COT according to some exemplary embodiments of the present disclosure. [Figure 6] FIG. 6 shows a flowchart of a method implemented in a first device according to some exemplary embodiments of the present disclosure. [Figure 7] FIG. 7 shows a flowchart of a method implemented in a second device according to some other exemplary embodiments of the present disclosure. [Figure 8] FIG. 8 shows a simplified block diagram of an apparatus suitable for practicing exemplary embodiments of the present disclosure. [Figure 9] 9 shows a block diagram of an exemplary computer-readable medium according to some exemplary embodiments of the present disclosure. Throughout the drawings, the same or similar reference numerals represent the same or similar elements. DETAILED DESCRIPTION OF THE INVENTION

[0013] The principles of the present disclosure will now be described with reference to some exemplary embodiments. It should be understood that these embodiments are provided for illustrative purposes to help those skilled in the art understand and practice the present disclosure, and are not intended to imply any limitation on the scope of the present disclosure. The embodiments described herein can be implemented in various ways other than those described below.

[0014] 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 belongs.

[0015] References in this disclosure to "one embodiment," "an embodiment," "an exemplary embodiment," etc. indicate that the described embodiment may include a particular feature, structure, or characteristic, but not all embodiments need include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is understood that it is within the knowledge of one of ordinary skill in the art to affect such feature, structure, or characteristic in connection with other embodiments, whether or not explicitly stated.

[0016] Although terms such as "first" and "second" may be used herein to describe various elements, it should be understood that these elements are not limited by these terms. These terms are merely used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of the exemplary embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0017] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit 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 as used herein, the terms "comprises," "comprising," "has," "having," "includes," and / or "including" 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.

[0018] As used herein, the term "circuitry" may refer to one or more or all of the following: (a) hardware-only circuit implementations (e.g., analog and / or digital-only implementations); and (b) a combination of hardware circuitry and software, e.g., (where applicable); (i) a combination of analog and / or digital hardware circuitry and software / firmware; and (ii) Software (including digital signal processors), software, and a portion of a hardware processor with memory(s) that work together to cause a device such as a mobile phone or server to perform various functions. (c) Hardware circuit(s) and processor(s), such as microprocessor(s) or portions of microprocessors, that require software (e.g., firmware) to operate, but the software may not be present when not necessary for operation.

[0019] This definition of circuit applies to all uses of the term in this application, including any claims. As a further example, as used herein, the term circuit also covers simply a hardware circuit or processor (or processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware implementation. The term circuit also covers, for example, a baseband or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or network device, if applicable to the recitation of a particular claim.

[0020] As used herein, the term "communication network" refers to a network conforming to any suitable communication standard, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed ​​Packet Access (HSPA), or Narrowband Internet of Things (NB-IoT). Furthermore, communications between terminal equipment and network devices in a communication network may be performed according to any suitable generation of communication protocols, 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 currently known or developed in the future. Embodiments of the present disclosure may be applied to various communication systems. Given the rapid development of communications, there will, of course, be future communication technologies and systems in which the present disclosure may be embodied. The scope of the present disclosure should not be considered limited to only the aforementioned systems.

[0021] As used herein, the term "network device" refers to a node in a communication network through which terminal equipment accesses the network and receives services therefrom. A network device may refer to a base station (BS) or access point (AP), such as a Node B (NodeB or NB), evolved Node B (eNodeB or eNB), NR NB (also known as gNB), remote radio unit (RRU), radio header (RH), remote radio head (RRH), relay, integrated access backhaul (IAB) node, low-power nodes such as femto and pico, non-terrestrial network (NTN) or non-terrestrial network devices such as satellite network devices, low Earth orbit (LEO) satellites, and geostationary Earth orbit (GEO) satellites, and airborne network devices, depending on the terminology and technology applied. Furthermore, the term "terminal equipment" refers to any terminal equipment capable of wireless communication. In the following description, the terms "terminal equipment," "terminal," "user equipment," and "UE" may be used interchangeably.

[0022] As mentioned above, sidelink communication has been proposed. In the sub-7 GHz unlicensed spectrum, the Listen-Before-Talk (LBT) channel access mechanism ensures coexistence between NR and other systems. Here, a UE that wants to perform a sidelink transmission must first successfully complete an LBT check before it can start the same transmission.

[0023] For a UE to pass the LBT check, it must confirm that the channel is available for use during several consecutive clear channel assessment (CCA) slots. In sub-7 GHz, each of these slots lasts 9 μs. The UE determines that a channel is available for use during a CCA slot if the measured power (i.e., the energy collected during the CCA slot) is below a specified threshold (which may vary depending on the operating band and region). As used herein, the term "listen-before-talk (LBT)" refers to a technique used in wireless communications whereby a wireless transmitter first senses its wireless environment before beginning transmission. LBT can be used by wireless devices to find networks in which the device is authorized to operate or to find a free wireless channel on which to operate. For example, signal detection (SD) may be used in LBT. The SD threshold is sometimes referred to as the preamble carrier sense threshold. By way of example only, the SD threshold may be approximately 4 dB signal-to-noise ratio (SNR), statistically sufficient for most radios to detect and decode a preamble. In other words, a radio can typically decode a preamble transmission it receives with the received signal about 4 dB above the noise floor. Alternatively, energy detection can be used with LBT.

[0024] As used herein, the term "clear channel assessment (CCA)" refers to a technique for assessing an RF medium. CCA may involve a physical layer radio listening to the RF medium using a CCA threshold to listen for RF transmissions. For example, energy detection may be used in CCA. An energy detection (ED) threshold is used to detect other types of RF transmissions during CCA. If the energy detected on a channel is less than the energy detection threshold, the channel may be considered available for transmission. If the energy detected on a channel is greater than the energy detection threshold, the channel may be considered busy.

[0025] When a UE initiates a communication (i.e., the UE acts as an initiating device), the UE must obtain the "right" to access the channel for a certain period (denoted in the regulations as Channel Occupancy Time (COT)) (e.g., period 120 shown in FIG. 1) by applying an "extended" LBT procedure, where the channel must be considered free for the entire duration of the Contention Window (CW) (denoted as period 110 in FIG. 1). This "extended" LBT procedure is commonly known as LBT Type 1.

[0026] The duration of both the COT and CW depends on the channel access priority class (CAPC) associated with the UE's traffic, as shown in Table 1. Control plane traffic (e.g., PSCCH) is transmitted with p=1, while user plane traffic has p>1. Table 1 shows the details of LBT Type 1 for the UU uplink (UL), but the parameters of LBT Type 1 for the downlink (DL) can also be applied in principle to SL. [Table 1]

[0027] When a UE (which can be referred to as the "initiating device") that initiates a transmission successfully completes an LBT Type 1, it obtains a COT with a duration associated with the corresponding CAPC and performs the transmission. For example, as shown in FIG. 2A, during COT 201, the initiating device can perform transmissions 211 and 212, with a gap 202 between the two transmissions. As shown in FIG. 2B, during COT 211, the initiating device can perform transmission 213, and the responding device can perform transmission 221. There is also a gap 203 between transmissions 213 and 221. The obtained COT remains valid even if the initiating device pauses its transmission; however, if the initiating device wants to perform a new transmission (within the COT), it still needs to perform a "reduced" LBT procedure.

[0028] This "reduced" LBT procedure is commonly known as LBT Type 2 and includes the following variations:

[0029] Type 2A (25 μs LBT) - relates to SL transmissions within an initiating device that has acquired a COT when the gap between two SL transmissions (e.g., gap 202 and gap 203 of an SL transmission following another SL transmission) is 25 μs or more.

[0030] Type 2B (16 μs LBT) - relates to SL transmissions in an initiating device that obtains a COT when the gap between two SL transmissions (eg, gap 202 and gap 203) is exactly equal to 16 μs.

[0031] Type 2C (without LBT) - relates to SL transmissions within an initiating device that has obtained a COT, where the gap between two SL transmissions (e.g., gap 202 and gap 203) is 16 μs or less and the allowed duration of an SL transmission is 584 μs or less.

[0032] The initiating device can share its acquired COT with the intended receiving device (responding device). For this purpose, the initiating device must inform the responding device (e.g., via a control signal) of the duration of this COT. The responding device uses this information to determine which type of LBT to apply when performing a transmission that indicates that the intended receiver is the initiating device. If the responding device's transmission is outside the range of the COT, the responding device must acquire a new COT using LBT type 1 with the appropriate channel access priority class (CAPC).

[0033] SL communication between UEs via PC5 is based on the principle of transmitter (Tx UE)-oriented one-to-many broadcast. On the one hand, a Tx UE transmits SL to an Rx UE or a group of Rx UEs, or all Rx UEs in the vicinity of the Tx UE, using resources from a (pre-)configured resource pool to transmit at least SL control information (SCI) used as a scheduling assignment for SL data transmission. As used herein, the term "TX UE" may refer to a UE that can transmit data to other UEs when performing sidelink communication with other UEs. As used herein, the term "RX UE" may refer to a UE that can receive data from other UEs when performing sidelink communication with other UEs. On the other hand, an Rx UE must receive at least all SCI instances and, based on the source (SRC) and / or destination (DST) IDs (SRC corresponds to the Tx side and DST corresponds to the Rx side) indicated in the received SCI instance, determine whether the received SCI and corresponding SL data transmission are intended for the Rx UE to receive, and continue monitoring on the (pre-)configured resource pool to receive SL. This applies to all cast types on SL, including unicast, groupcast, and broadcast.

[0034] Traditionally, there are two resource allocation modes for SL transmissions, called Mode 1 and Mode 2. Mode 1 is based on using scheduled resources or a grant from the serving BS. This means that the Tx UE must be in the serving BS's radio resource control (RRC) CONNECTED state to receive Mode 1 resource allocation. Mode 2 is based on the Tx UE's autonomous allocation or selection of resources from a preconfigured Tx resource pool. Mode 2 resource selection can be based on simple random selection or sensing-based selection. The latter is used for normal operation, while the former is used for exceptional operation or situations using a specific preconfigured resource pool. Mode 2 can be used when the Tx UE is in in-coverage (IC) or out-of-coverage (OoC) and in RRC IDLE, RRC INACTIVE, or RRC CONNECTED states. Table 2 below specifies the SCIs used for scheduling SL transmissions and facilitates Mode 2 sensing-based resource allocation. [Table 2]

[0035] For SL operating in unlicensed spectrum, after a successful "extended" LBT procedure, i.e., LBT Type 1, an SL UE can access the channel for a duration of the channel occupation time (COT). The obtained COT may be shared from the initiating device to the responding device. The shared COT remains valid even if the associated SL UE pauses transmission; however, if the associated SL UE pauses transmission within the COT and wants to perform a new transmission, a "reduced" LBT procedure is required. As used in this section, the term "channel occupation time (COT)" may refer to the total time that the eNB / gNB / UE and any eNB / gNB / UE(s) sharing the channel occupation perform transmissions on the channel after the eNB / gNB / UE performs the corresponding channel access procedure described in this section. For purposes of determining the channel occupation time, if the transmission gap is 25 μs or less, the gap duration is counted into the channel occupation time. The channel occupation time may be shared for transmission between the eNB / gNB / UE(s) and the corresponding eNB / gNB / UE(s).

[0036] For SL communications, either gNB-scheduled Mode 1 or sensing-based Mode 2 resource allocation enables frequency division multiplexing (FDM) between SL transmissions from different SL Tx UEs. Considering COT sharing in SL operating in unlicensed bands, in principle, all SL UEs can share the same COT without causing interference between SL transmissions from different UEs due to the Mode 1 or Mode 2 resource allocation designed for SL operation. However, utilizing the COT sharing mechanism and defining the scope of COT sharing among different groups of SL UEs makes it possible to manage load balancing between different SL bands in licensed or unlicensed bands. Furthermore, scheduled or sensing-based SL resource allocation (Mode 1 and Mode 2) ensures that SL transmissions from different SL-U UEs do not interfere with each other. Similar to LBT measurements, identifying transmission pauses / gaps during COT periods can take into account not only SL-U UEs sharing the same COT but also, to some extent, other SL transmissions in the targeted unlicensed band.

[0037] To solve at least some of the above problems, a new solution for COT sharing is needed. According to an embodiment of the present disclosure, a first device determines one or more second devices with which to share a COT for sidelink transmissions using an unlicensed spectrum band. The first device transmits information indicating the COT shared by the first device and the one or more second devices. The second device determines transmission gaps within the COT and performs LBT / CCA on the unlicensed spectrum band based on the determined gaps. In this way, COT sharing is achieved among SL devices. This can improve spectral efficiency and avoid resource waste.

[0038] 3 shows a schematic diagram of a communication environment 300 in which embodiments of the present disclosure may be implemented. The communication environment 300, which is part of a communication network, includes terminal equipment 310-1, terminal equipment 310-2, terminal equipment 310-1, terminal equipment 310-2, ..., terminal equipment 310-N, which may be collectively referred to as "terminal equipment 310." The communication environment 300 includes a network device 320. The number N may be any suitable integer.

[0039] The communication environment 300 may include any suitable number of devices and cells. In the communication environment 300, the terminal equipment 310 and the network device 320 may communicate data and control information with each other. The link from the network device 320 to the terminal equipment 310 is called the downlink (DL), and the link from the terminal equipment 310 to the network device 320 is called the uplink (UL).

[0040] It should be understood that the number of first devices and cells and their connections shown in Figure 3 are shown for illustrative purposes and are not intended to imply any limitations. Communication environment 300 may include any number of devices and networks suitable for implementing embodiments of the present disclosure.

[0041] Communications in communication environment 300 may be conducted according to any suitable communication protocol(s), 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), wireless local network communication protocols such as Institute of Electrical and Electronics Engineers (IEEE) 802.11, and / or other protocols now known or developed in the future. Furthermore, communications may 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 multiple access (OFDM), discrete Fourier transform spread OFDM (DFT-s-OFDM), and / or any other technology now known or developed in the future.

[0042] Exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. Reference is now made to FIG. 4 , which illustrates a signal flow 400 for sharing a COT according to an exemplary embodiment of the present disclosure. The signal flow 400 may include an initiating device (i.e., a first device) and a responding device (i.e., a second device). In some embodiments, the initiating device may be a terminal device (e.g., terminal device 310-1), and the responding device may be another terminal device (e.g., terminal device 310-2). Alternatively, the initiating device may be a network device (e.g., network device 320). In other embodiments, the initiating device may be a sidelink unlicensed (SL-U)-related device, such as a radio side unit (RSU) operating in an unlicensed spectrum band. The terms “shared spectrum band” and “unlicensed spectrum band” may be used interchangeably. Embodiments of the present disclosure are not limited in this respect. By way of example only, the signal flow 400 may include the terminal device 310-1 and the terminal device 310-2. As an example, terminal device 310-1 functions as an initiating device, and terminal device 310-2 functions as a responding device. Note that terminal device 310-1 and terminal device 310-2 are interchangeable. In other words, terminal device 310-1 can be the responding device, and terminal device 310-2 can be the initiating device.

[0043] The terminal device 310-1 may determine a channel occupation time (COT) (4010). In some embodiments, the terminal device 310-1 may obtain the COT using an LBT / CCA mechanism. For example, the COT may be obtained using a conventional LBT mechanism. Alternatively, the LBT may take into account SL-U transmissions. For example, if the terminal device 310-1 has SL operation capability (e.g., an SL-U UE or UE-type RSU), it may monitor SL-U transmissions and measure the energy of the monitored SL-U transmissions.

[0044] The terminal device 310-1 can determine the result of the LBT (or CCA) in the unlicensed spectrum band based on the difference between the energy of the sidelink transmission in the unlicensed spectrum band and the measured energy of the LBT (or CCA). For example, if the difference is within a threshold difference, the LBT can be considered a successful COT acquisition by the terminal device 310-1. In other words, if the energy detection value of the LBT is similar to the calculated energy level of the monitored SL-U transmission, the LBT can be considered a successful COT acquisition by the COT-initiating device. Alternatively, if the energy detection value in the LBT is higher than the calculated energy level of the monitored SL-U transmission by more than a set threshold, the LBT can be considered a failure.

[0045] The terminal device 310-1 determines the range of COT sharing (4020). In other words, the terminal device 310-1 determines that one or more second / capable devices (e.g., terminal device 310-2 and / or terminal device 310-3) will share the COT for sidelink transmissions using the unlicensed spectrum band (4020). As used herein, the term "range of COT sharing" may refer to whether the obtained COT is shared with all SL-U UEs or only with a portion of the SL-U UEs or specific SL-U UEs. In some embodiments, the terminal device 310-1 may determine the range of COT sharing based on the sensing results of SL operations in the associated SL band. Alternatively or additionally, the range of COT sharing may be determined based on the results of LBT / CCA in the unlicensed spectrum band for the obtained COT. In other embodiments, the terminal device 310-1 may determine the range of COT based on the type of service and / or quality of service (QoS) of the SL communication involving the terminal device 310-1.

[0046] In some embodiments, the terminal device 310-1 may determine the one or more second / capable devices based on a congestion level (e.g., a channel busy rate measurement) on the further sidelink spectrum band associated with the sidelink communication of the one or more second / capable devices. For example, the terminal device 310-1 may determine to allocate COTs to all nearby SL-U UEs if the congestion level on the further sidelink spectrum band is higher than a configured threshold.

[0047] Alternatively or additionally, the terminal device 310-1 may determine one or more second / capable devices based on the results of the CCA / LBT in the unlicensed spectrum band. In some embodiments, if the results of the CCA / LBT are better than a set threshold and / or condition, the terminal device 310-1 may determine to allocate COT to all nearby SL-U UEs. For example, if the percentage of clear channels detected in the past N CCAs is higher than a predetermined percentage value, the terminal device 310-1 may determine to allocate COT to all nearby SL-U UEs. Otherwise, the terminal device 310-1 may determine to allocate COT to only a portion of SL-UEs or a specific SL-UE that has established SL groupcast or unicast communication with the terminal device 310-1. As another example, if the energy detection (ED) measurements in the past M CCAs are smaller than a predefined value, the terminal device 310-1 may determine to allocate COT to all nearby SL-UEs. Otherwise, the terminal device 310-1 may decide to allocate the COT to only a portion of the SL-UEs or to one specific SL-UE that has established SL groupcast or unicast communication with the terminal device 310-1.

[0048] In other embodiments, the terminal device 310-1 may determine one or more secondary / responding devices based on the QoS of the terminal device 310-1's sidelink communication. For example, if the QoS of the SL service is lower than a threshold, the terminal device 310-1 may determine to allocate COT to all nearby SL-U UEs. In some embodiments, the terminal device 310-1 may determine one or more secondary / capable devices based on predicted reference signal received power (RSRP) measured by one or more secondary / capable devices. Alternatively, the terminal device 310-1 may determine one or more secondary / capable devices based on any combination of the above conditions (e.g., congestion level, CCA / LBT history results, QoS).

[0049] In an embodiment, the terminal device 310-1 may determine to allocate a COT to a nearby target SL-U UE if the congestion measurement value of the SL-U in the target unlicensed spectrum is higher than a set threshold. Alternatively, the terminal device 310-1 may determine to allocate a COT to a nearby target SL-U UE if the QoS of the SL service involving the terminal device 310-1 is higher than a set threshold. The terminal device 310-1 may determine to allocate a COT to a nearby target SL-U UE based on any combination of the above conditions (e.g., congestion level, QoS).

[0050] Alternatively or additionally, the terminal device 310-1 can determine one or more second / responding devices based on predicted reference signal received power (RSRP) measured by one or more second / responding devices. For example, the terminal device 310-1 can determine to allocate the acquired COT to SL-UEs in its vicinity by indicating an RSRP threshold that the COT responding device should reach. In this embodiment, the terminal device 310-2 can measure the RSRP of the COT from which it starts transmission to determine whether the terminal device 310-2 is within the range of the shared COT. In some embodiments, the indicated RSRP threshold can be based on congestion (e.g., a CBR measurement for intra-system congestion and a received signal strength indicator (RSSI) for inter-system congestion). For example, if there is congestion, the RSRP threshold will be high, if there is no congestion, the RSRP threshold will be low, or vice versa if the acquired COT corresponds to higher priority traffic.

[0051] In another example embodiment, the terminal device 310-1 may determine the one or more second / responding devices based on a logical relationship with the terminal device 310-1, which may include (or be given by) whether the one or more second / responding devices communicate with the terminal device 310-1 over the sidelink in unicast, groupcast, or broadcast sidelink communications, or whether there are common or shared sidelink features, services, or resources provided between the terminal device 310-1 and the one or more second / responding devices, such as sidelink synchronization, sidelink control information, resource pools, etc.

[0052] The terminal device 310-1 transmits information to the terminal device 310-2 (4030). This information indicates the COT to be shared by the first device (i.e., the initiating device) and the determined one or more second devices (i.e., the responding devices). In some embodiments, if the information is transmitted using either sidelink channel information (SCI) or a higher layer message (e.g., a medium access control (MAC) control element (CE) or RRC signaling), the COT sharing scope can be indicated using a corresponding SL broadcast type. In some embodiments, if the terminal device 310-1 determines to allocate a COT to all SL-U UEs, the COT sharing information can be transmitted via SL broadcast. Alternatively or additionally, if the terminal device 310-1 determines to allocate a COT to a target SL-U UE, the COT sharing information can be transmitted via SL groupcast or SL unicast. For example, if the COT is allocated to a group of SL-U UEs, the information can be transmitted via SL groupcast. Alternatively, if the COT is assigned to one specific SL-U UE, the terminal device 310-1 may transmit the information via SL unicast.

[0053] Alternatively, if the information is provided via physical signaling (e.g., by a predefined reference signal), the association between the COT sharing range and the corresponding physical signal must be configured for the relevant SL-U UEs. For example, one physical signal can be configured to allocate COT to all SL-U UEs. SL groupcast or unicast UEs can configure a specific physical signal for signaling COT sharing information via network configuration, application configuration, or PC-5S or SL RRC configuration signaling. Furthermore, other configuration parameters, such as the different thresholds mentioned above, can also be configured via the network, application configuration, or PC-5S or SL RRC configuration signaling mechanism between the first and second devices (if both have SL capabilities).

[0054] Upon receiving the COT sharing information from the terminal device 310-1, the terminal device 310-2 determines a transmission gap within the channel occupancy time (4040). In some embodiments, the terminal device 310-2 can determine the transmission gap based on the determined sidelink transmissions from one or more second devices. For example, if a COT is assigned to all SL-U UEs, all monitored SL transmissions in the unlicensed spectrum band need to be considered when determining the transmission gap. If a COT is shared with the target SL-U UE(s), the SL transmissions using the shared COT need to be considered in calculating the transmission gap.

[0055] In some embodiments, to facilitate identification of an SL transmission using a shared COT, in one option, the SL transmission using the shared COT may indicate an identifier of the shared COT. In some embodiments, the identifier of the shared COT may be an identifier of the terminal device 310-1, for example, the ID of the source L1 or L2 of the terminal device 310-1. Alternatively, the identification information of the shared COT may be indicated in the first or second phase of the SCI of the SL-U transmission when the terminal device 310-1 transmits the COT sharing information.

[0056] In other embodiments, when COT sharing information is transmitted using an SL groupcast, SL transmissions targeted to the same SL groupcast (e.g., identified by the same SL groupcast L2 ID) may be considered as SL transmissions using a shared COT and therefore may be taken into account in calculating the transmission gap.

[0057] In one embodiment, the transmission gap can be determined not only by taking into account the SL transmission associated with the shared COT, but also by taking into account other SL transmissions in the targeted unlicensed spectrum band if the other SL transmissions meet certain criteria. For example, the criteria can be defined by the RSRP of the monitored other SL transmissions (either the RSRP of the SL control channel PSCCH or the RSRP of the SL data channel PSSCH). If the RSRP of the other SL transmission is higher than a configured threshold or higher than the RSRP of the SL transmission from the initiating / responding device, the other SL transmission is taken into account when determining the transmission gap.

[0058] In other embodiments, the criteria may be defined by the location / distance of other SL transmitting UEs: If the location / distance between the UE calculating the transmission gap and the other SL transmitting UEs is within a set threshold or within a location / distance towards the COT initiating / responding device, the other SL transmissions are taken into account when determining the transmission gap.

[0059] FIG. 5 illustrates different types of gaps during a COT period. As shown in FIG. 5, terminal device 310-1 can perform transmissions 501-1 and 501-2. Terminal device 310-2 can perform transmission 502, and terminal device 310-3 can perform transmission 503 during COT 520. Terminal device 310-2 and terminal device 310-1 share COT 520. Terminal device 310-1 and / or terminal device 310-2 can determine a transmission gap 521 in which there is no transmission. In some embodiments, if terminal device 310-1 determines a transmission gap based on determined sidelink transmissions from one or more second devices, terminal device 310-1 can determine a transmission gap 522. In other words, a terminal device that does not share COT 520 can perform transmission 504 within COT 520 if it can obtain its own COT through a successful LBT. If the terminal device 310-1 and / or the terminal device 310-2 considers only sidelink transmissions related to the COT 520, the gap 522 is determined. Alternatively, if SL transmissions other than the shared COT are considered for the calculation of the transmission gap, the terminal device 310-1 may not determine a transmission gap 522 if the transmission 504 meets the set criteria.

[0060] Returning to FIG. 4, the terminal device 310-2 may determine an LBT type based on the transmission gap within the COT (4050). If an LBT is still required before an SL transmission (e.g., if the detected transmission gap is greater than 16 μs or 25 μs), the result of the LBT may be determined taking the SL transmission into consideration according to the resource reservation monitored from the SCI. In one embodiment, the initiating / responding device may determine the expected received energy from the SL transmission in the unlicensed spectrum band based on the resource reservation information monitored from the received SCI. If the measured energy of the LBT is similar to the determined energy of the SL transmission in the unlicensed spectrum band, the unlicensed spectrum channel may be recognized as unoccupied from the LBT because the channel is occupied by other SL-U users rather than other unlicensed spectrum band users.

[0061] The terminal device 310-2 performs LBT in the unlicensed spectrum band (4060). The monitored SL-U transmission for LBT may be based on the first-stage SCI received by the SL-U UE performing the LBT or transmission gap calculation. Alternatively, or additionally, the monitored DMRS for SL control and / or data transmission via the PSCCH / PSSCH may be based on the monitored DMRS. The terminal device 310-2 may determine the result of LBT (or CCA) in the unlicensed spectrum band based on the difference between the energy of the sidelink transmission in the unlicensed spectrum band and the measured energy of the LBT (or CCA). For example, if the difference is within a threshold difference, the LBT may be considered successful in obtaining the COT by the terminal device 310-2. In other words, if the energy detection in the LBT is similar to the calculated energy level of the monitored SL-U transmission, the LBT may be considered successful by the terminal device 310-2. Alternatively, if the energy detection in the LBT is higher than the calculated energy level of the monitored SL-U transmission, the LBT can be considered a failure.

[0062] In some embodiments, the terminal device 310-1 may determine a transmission gap (4070) if the terminal device 310-1 needs to transmit an SL again within the COT. The terminal device 310-1 may determine a transmission gap (4070) in the same manner as the terminal device 310-2 determines a transmission gap (4040). The terminal device 310-1 may determine an LBT type (4080) in the same manner as the determination (4050). In some embodiments, the terminal device 310-1 may perform an LBT (4090). Note that the determination of a transmission gap (4070), the determination of an LBT type (4080), and the execution of an LBT (4090) may be performed before or after the determination of a transmission gap (4040), the determination of an LBT type (4050), and the execution of an LBT (4060). The embodiments are not limited to this aspect.

[0063] 6 shows a flowchart of an example method 600 according to some example embodiments of the present disclosure. For purposes of discussion, method 600 will be described from the perspective of an initiating device. For illustrative purposes only, method 600 will be described with reference to terminal device 310-1.

[0064] In block 610, the terminal device 310-1 determines one or more second devices for sharing the channel occupancy time of the sidelink transmission using the unlicensed spectrum. In some embodiments, the terminal device 310-1 can determine the one or more second devices according to at least one of the following conditions: a congestion level of a further sidelink frequency band associated with the sidelink communication of the one or more second devices; a clear channel assessment or listen-before-talk result in the unlicensed spectrum; an expected reference signal received power measured by the one or more second devices; or a quality of service of the sidelink communication of the terminal device 310-1.

[0065] Alternatively or additionally, the terminal device 310-1 may determine the one or more second / responding devices based on a logical relationship with the terminal device 310-1, which may include (or be given by) whether the one or more second / responding devices communicate with the terminal device 310-1 over the sidelink in unicast, groupcast, or broadcast sidelink communication, or whether there are common or shared sidelink functions, services, or resources provided between the terminal device 310-1 and the one or more second / responding devices, such as sidelink synchronization, sidelink control information, resource pools, etc.

[0066] At block 620, terminal device 310-1 transmits information indicating the channel occupancy time shared by the first device and the determined one or more second devices.

[0067] In some embodiments, the terminal device 310-1 can determine a transmission gap within the channel occupancy time based at least on the determined sidelink transmissions from the one or more second devices, and can perform listen-before-talk in the unlicensed spectrum based on the determined gap.

[0068] In another embodiment, the terminal device 310-1 may transmit sidelink control information to one or more second devices indicating the identity of the shared channel occupation time. In this situation, when the sidelink transmission indicating the identity of the shared channel occupation time is made, the terminal device 310-1 may determine a transmission gap within the channel occupation time based on the sidelink transmission.

[0069] Alternatively, the terminal device 310-1 may transmit the shared channel occupation time information via a sidelink groupcast. If the sidelink transmissions are related to the same sidelink groupcast, the terminal device 310-1 may determine a transmission gap within the channel occupation time based on the sidelink transmissions.

[0070] In some embodiments, the terminal device 310-1 may perform measurements on other sidelink transmissions from a third device different from the determined one or more second devices. In this case, if a measurement result on the other sidelink transmission exceeds a threshold, the terminal device 310-1 may determine a transmission gap based on the sidelink transmission and the other sidelink transmission. The measurement on the other sidelink transmission may include at least one of measuring the reference signal received power of the other sidelink transmission from the third device or measuring the distance between the third device and the first device.

[0071] In another embodiment, the terminal device 310-1 may determine the energy of the sidelink transmission on the sidelink over the unlicensed spectrum band, and then determine the outcome of the listen-before-talk over the unlicensed spectrum band as a function of the difference between the determined energy and the measured energy of the listen-before-talk.

[0072] 7 shows a flowchart of an example method 700 according to some example embodiments of the present disclosure. For purposes of discussion, method 700 will be described from the perspective of a responding device. For illustrative purposes only, method 700 will be described with reference to terminal device 310-2.

[0073] In block 710, terminal device 310-2 receives information from a first device indicating a channel occupancy time shared by the first device and a second device. The information may be transmitted via either SL broadcast, SL groupcast, or SL unicast.

[0074] In block 720, the terminal device 310-2 determines a transmission gap within the channel occupation time based at least in part on the sidelink transmission from the first device. In some embodiments, the terminal device 310-2 may receive sidelink control information from the first device indicating the identity of the shared channel occupation time. In this situation, if the sidelink transmission indicates the identity of the shared channel occupation time, the terminal device 310-2 may determine a transmission gap within the channel occupation time based on the sidelink transmission.

[0075] Alternatively, if information indicating the channel occupation time is received via a sidelink groupcast and the sidelink transmissions are associated with the same sidelink groupcast, the terminal device 310-2 may determine a transmission gap within the channel occupation time based on the sidelink transmissions. In some embodiments, the terminal device 310-2 may perform measurements on other sidelink transmissions from a third device different from the first device. In this situation, if the measurement results for the other sidelink transmissions exceed a threshold, the terminal device 310-2 may determine a transmission gap based on the sidelink transmission and the other sidelink transmissions. The measurements for the other sidelink transmissions may include at least one of measuring the reference signal received power of the other sidelink transmissions from the third device or measuring the distance between the third device and the second device.

[0076] In block 730, the terminal device 310-2 performs listen-before-talk over the unlicensed spectrum band based on the determined gap. In some embodiments, the terminal device 310-2 can determine the energy of a sidelink transmission over the sidelink over the unlicensed spectrum band. The terminal device 310-2 can determine the results of the listen-before-talk over the unlicensed spectrum band according to determining the difference between the energy and the measured energy of the listen-before-talk.

[0077] In some exemplary embodiments, a first device (e.g., terminal device 310-1) capable of performing any of method 600 may comprise means for performing each operation of method 600. The means may be implemented in any suitable form. For example, the means may be implemented in a circuit or a software module. The first device may be implemented as or included in terminal device 310-1. In some exemplary embodiments, the means may comprise at least one processor and at least one memory containing computer program code. The at least one memory and the computer program code, in conjunction with the at least one processor, are configured to perform the performance of the device.

[0078] In some embodiments, the first device comprises means for determining one or more second devices with which to share a channel occupation time for sidelink transmissions using the unlicensed spectrum band; and means for transmitting, at the first device, information indicating the channel occupation time shared by the first device and the determined one or more second devices.

[0079] In some embodiments, the means for determining the one or more second devices comprises means for determining the one or more second devices according to at least one of the following conditions: a congestion level of a further sidelink frequency band associated with the sidelink communication of the one or more second devices; a clear channel assessment or listen-before-talk result in the unlicensed spectrum band; a predicted reference signal received power measured by the one or more second devices; a quality of service of the sidelink communication of the first device; or a logical relationship with the first device.

[0080] In some embodiments, the first device comprises means for determining a transmission gap within the channel occupancy time based at least on the determined sidelink transmissions from the one or more second devices, and means for performing listen-before-talk in the unlicensed spectrum band based on the determined gap.

[0081] In some embodiments, the first device comprises means for transmitting sidelink control information to the one or more second devices indicating the identity of the shared channel occupation time, and the means for determining transmission gaps within the channel occupation time comprises means for determining transmission gaps within the channel occupation time based on the sidelink transmission in accordance with the determination of the sidelink transmission indicating the identity of the shared channel occupation time.

[0082] In some embodiments, the means for transmitting information indicative of a channel occupation time shared by one or more second devices comprises means for transmitting the information via a sidelink groupcast, and the means for determining a transmission gap within the channel occupation time comprises means for determining a transmission gap within the channel occupation time based on the sidelink transmission in accordance with determining that the sidelink transmission is related to the sidelink groupcast.

[0083] In some embodiments, the first device comprises means for performing measurements on other sidelink transmissions from a third device different from the determined one or more second devices, and the means for determining a transmission gap within the channel occupancy time comprises means for determining a transmission gap based on the sidelink transmission and the other sidelink transmissions pursuant to a determination that a measurement result of the other sidelink transmission exceeds a threshold.

[0084] In some embodiments, the measurements related to the other sidelink transmissions include at least one of measurements of reference signal received power of the other sidelink transmissions from the third device or measurements of the distance between the third device and the first device.

[0085] In some embodiments, the first device comprises means for determining an energy of a sidelink transmission on the sidelink over the unlicensed spectrum band, and means for determining a result of the listen-before-talk in the unlicensed spectrum band as a function of a difference between the energy and a measured energy of the listen-before-talk.

[0086] In some embodiments, the first device is a terminal device or a network device, and the second device is another terminal device or another network device.

[0087] In some demonstrative embodiments, a first device (e.g., terminal device 310-2) capable of performing any of method 700 may comprise means for performing each operation of method 700. The means may be implemented in any suitable form. For example, the means may be implemented in a circuit or a software module. The first device may be implemented as or included in terminal device 310-2. In some demonstrative embodiments, the means may comprise at least one processor and at least one memory containing computer program code. The at least one memory and the computer program code, in conjunction with the at least one processor, are configured to perform the performance of the device.

[0088] In some embodiments, the second device comprises: means for receiving, at the second device, information from the first device indicating a channel occupation time shared by the first device and the second device; means for determining a transmission gap within the channel occupation time based at least in part on the sidelink transmission from the first device; and means for performing listen-before-talk in the unlicensed spectrum band based on the determined gap.

[0089] In some embodiments, the second device comprises means for receiving sidelink control information from the first device indicating an identity of the shared channel occupation time, and the means for determining a transmission gap within the channel occupation time comprises means for determining a transmission gap within the channel occupation time based on the sidelink transmission in accordance with the determination of the sidelink transmission indicating the identity of the shared channel occupation time.

[0090] In some embodiments, the means for receiving information indicative of a channel occupation time shared by the one or more second devices comprises means for receiving the information via a sidelink groupcast, and the means for determining a transmission gap within the channel occupation time comprises means for determining a transmission gap within the channel occupation time based on the sidelink transmission in accordance with determining that the sidelink transmission is associated with the sidelink groupcast.

[0091] In some embodiments, the second device comprises means for performing measurements on another sidelink transmission from a third device different from the first device, and the means for determining a transmission gap within the channel occupancy time comprises determining a transmission gap based on the sidelink transmission and the other sidelink transmission pursuant to a determination that the measurement result on the other sidelink transmission exceeds a threshold.

[0092] In some embodiments, the measurements related to the other sidelink transmissions include at least one of measuring a reference signal received power of the other sidelink transmissions from the third device or measuring a distance between the third device and the second device.

[0093] In some embodiments, the second device comprises means for determining an energy of a sidelink transmission on the sidelink over the unlicensed spectrum band and means for determining a result of the listen-before-talk over the unlicensed spectrum band according to determining a difference between the energy and a measured energy of the listen-before-talk.

[0094] In some embodiments, the first device is a terminal device or a network device, and the second device is another terminal device or another network device.

[0095] 8 is a simplified block diagram of a device 800 suitable for implementing an exemplary embodiment of the present disclosure. The device 800 may be provided to implement a communication device such as, for example, the terminal equipment 310 or the network device 320 shown in FIG. 3. As shown, the device 800 includes one or more processors 810, one or more memories 820 coupled to the processors 810, and one or more communication modules 840 coupled to the processors 810.

[0096] The communications module 840 is for bidirectional communication. The communications module 840 has one or more communications interfaces to facilitate communication with one or more other modules or devices. The communications interfaces may represent any interface necessary for communication with other network elements. In some exemplary embodiments, the communications module 840 may include at least one antenna.

[0097] The processor 810 may be of any type suitable for a local technology network and may include, by way of non-limiting example, one or more of 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. The device 800 may have multiple processors, such as application-specific integrated circuit chips that are time-slaved to a clock that synchronizes a main processor.

[0098] The memory 820 may include one or more nonvolatile memories and one or more volatile memories. Examples of nonvolatile memory include, but are not limited to, read-only memory (ROM) 824, electrically programmable read-only memory (EPROM), flash memory, hard disks, compact disks (CDs), digital video disks (DVDs), optical disks, laser disks, and other magnetic and / or optical storage devices. Examples of volatile memory include, but are not limited to, random access memory (RAM) 822 and other volatile memories that do not stay up to date during periods of power interruption.

[0099] The computer program 830 includes computer-executable instructions that are executed by the associated processor 810. The program 830 may be stored in a memory, for example, the ROM 824. The processor 810 can load the program 830 into the RAM 822 to perform any suitable operations and processes.

[0100] An exemplary embodiment of the present disclosure may be implemented by a program 830 such that the device 800 may execute any process of the present disclosure, as discussed with reference to Figures 4 to 7. Also, an exemplary embodiment of the present disclosure may be implemented by hardware or a combination of software and hardware.

[0101] In some exemplary embodiments, the program 830 may be tangibly contained in a computer-readable medium, which may be included in the device 800 (such as in memory 820) or other storage accessible by the device 800. The device 800 may load the program 830 from the computer-readable medium into RAM 822 for execution. The computer-readable medium may include any type of tangible non-volatile storage device, such as a ROM, an EPROM, a flash memory, a hard disk, a CD, a DVD, and other magnetic and / or optical storage devices. FIG. 9 shows an example of a computer-readable medium 900 in the form of an optical storage disk. The computer-readable medium has the program 830 stored thereon.

[0102] In general, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described using block diagrams, flowcharts, or some other graphical representations, it should be understood that the blocks, apparatus, systems, techniques, or methods described herein may be implemented in, by way of non-limiting example, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller, or other computing device, or some combination thereof.

[0103] 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 contained in program modules that execute on a target physical or virtual processor device to perform any of the methods described above with reference to FIGS. 4-7. 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 may be combined or split among program modules as desired in various embodiments. The machine-executable instructions of the program modules may be executed in local or distributed devices. In distributed devices, the program modules may be located in both local and remote storage media.

[0104] Program code for implementing the methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, such that when the program code is executed by the processor or controller, the functions / operations specified in the flowcharts and / or block diagrams are performed. The program code may run entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0105] In the context of the present disclosure, computer program code or associated data may be carried by any suitable carrier to enable a device, apparatus, or processor to perform the various processes and operations as described above. Examples of carriers include signals, computer-readable media, etc.

[0106] The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable medium includes, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer-readable storage medium 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.

[0107] Furthermore, although operations are described in a particular order, this should not be understood as requiring such operations to be performed in the particular order shown, or sequentially, or that all of the operations shown be performed, to achieve desirable results. In certain situations, multitasking and parallel processing may be advantageous. Similarly, while several specific implementation details are included in the above description, these should not be construed as limiting the scope of the disclosure, but rather as descriptions of features that may be specific to particular embodiments. 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 subcombination.

[0108] Although the present disclosure has been described in language specific to structural features and / or methodological acts, it is to be understood that the present disclosure, as defined by the appended claims, is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. determining, at the first device, one or more second devices with which to share a channel occupation time for sidelink transmissions using the unlicensed spectrum; transmitting, at the first device, information indicating the channel occupancy time shared by the first device and the determined one or more second devices; determining a transmission gap within the channel occupancy time based at least on the determined sidelink transmissions from the one or more second devices; and performing listen-before-talk on the unlicensed spectrum band based on the determined transmission gap; transmitting sidelink control information to the one or more second devices indicating an identity of the shared channel occupation time; and Including, Determining the transmission gap within the channel occupancy time comprises: determining the transmission gap within the channel occupation time based on the sidelink transmissions in accordance with the determination of the sidelink control information indicating the identity of the shared channel occupation time. method.

2. Determining the one or more second devices includes: a congestion level of a further sidelink spectrum band associated with sidelink communications of one or more second devices; the results of a clear channel assessment or listen-before-talk in the unlicensed spectrum band; a predicted reference signal received power measured by the one or more second devices; quality of service of sidelink communication of the first device; a logical relationship with the first device; determining the one or more second devices according to at least one of the following conditions: The method of claim 1 , comprising:

3. transmitting the information indicative of a channel occupancy time shared by one or more second devices, transmitting the information via a sidelink groupcast; Determining the transmission gap within the channel occupancy time comprises: determining the transmission gap within the channel occupancy time based on the sidelink transmissions according to a determination that the sidelink transmissions are related to the sidelink groupcast. The method of claim 1.

4. performing measurements on other sidelink transmissions from a third device different from the determined one or more second devices; Determining the transmission gap within the channel occupancy time comprises: determining the transmission gap based on the sidelink transmission and the other sidelink transmission in accordance with a determination that a measurement result relating to the other sidelink transmission exceeds a threshold. The method of claim 1.

5. The measurements on the other sidelink transmissions include: - measuring the reference signal received power of the other sidelink transmission from the third device; or measuring the distance between the third device and the first device; The method of claim 4 , comprising at least one of:

6. determining an energy of a sidelink transmission on the sidelink on the unlicensed spectrum band; and determining a result of the listen-before-talk in the unlicensed spectrum band as a function of a difference between the energy and a measured energy of the listen-before-talk; The method of claim 1 further comprising:

7. The method according to any one of claims 1 to 6, wherein the first device is a terminal device or a network device and the second device is another terminal device or another network device.

8. receiving, at a second device, information from a first device indicating a channel occupancy time shared by the first device and the second device; determining a transmission gap within the channel occupancy time based at least in part on a sidelink transmission from the first device; and performing listen-before-talk in an unlicensed spectrum band based on the determined transmission gap; receiving sidelink control information from the first device indicating identity of shared channel occupation time; Including, Determining the transmission gap within the channel occupancy time comprises: determining the transmission gap within the channel occupation time based on the sidelink transmissions in accordance with the determination of the sidelink control information indicating the identity of the shared channel occupation time. method.

9. Receiving the information indicative of a channel occupancy time shared by one or more second devices includes: receiving the information via a sidelink groupcast; Determining the transmission gap within the channel occupancy time comprises: determining the transmission gap within the channel occupancy time based on the sidelink transmissions according to a determination that the sidelink transmissions are related to the sidelink groupcast. The method of claim 8.

10. performing measurements on other sidelink transmissions from a third device different from the first device; Determining the transmission gap within the channel occupancy time comprises: determining the transmission gap based on the sidelink transmission and the other sidelink transmission in accordance with a determination that a measurement result relating to the other sidelink transmission exceeds a threshold. The method of claim 8.

11. The measurements on the other sidelink transmissions include: - measuring the reference signal received power of the other sidelink transmission from the third device; or measuring the distance between the third device and the second device; The method of claim 10 , comprising at least one of:

12. determining an energy of a sidelink transmission on the sidelink on the unlicensed spectrum band; and determining a result of the listen-before-talk in the unlicensed spectrum band according to determining a difference between the energy and a measured energy of the listen-before-talk; The method of claim 8 further comprising:

13. 13. The method according to any one of claims 7 to 12, wherein the first device is a terminal device or a network device and the second device is another terminal device or another network device.

14. at least one processor; at least one memory containing computer program code; The at least one memory and the computer program code are configured to cause the at least one processor to cause the first device to perform the method of any one of claims 1 to 7. The first device.

15. at least one processor; at least one memory containing computer program code; The at least one memory and the computer program code are configured to cause the at least one processor to cause the second device to perform the method of any one of claims 8 to 13. Second device.

16. A computer readable medium containing program instructions for causing an apparatus to perform the method of any one of claims 1 to 7 or the method of any one of claims 8 to 13.

17. Apparatus comprising means for carrying out the method according to any one of claims 1 to 7 or the method according to any one of claims 8 to 13.

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