KR20240045085A - Method and apparatus for channel access in unlicensed communication - Google Patents

Abstract

A method and device for channel access in unlicensed band communication are disclosed. The method of the first terminal includes receiving shared information of the COT initiated by the second terminal from the second terminal, and determining whether SL transmission of the first terminal can be performed in the COT based on the shared information. A step, and if the SL transmission can be performed in the COT, performing the SL transmission in the COT shared by the second terminal.

Description

Method and device for channel access in unlicensed band communication {METHOD AND APPARATUS FOR CHANNEL ACCESS IN UNLICENSED COMMUNICATION}

This disclosure relates to channel access technology in a communication system, and more specifically, to channel access technology in a communication system using an unlicensed band.

With the advancement of information and communication technology, various wireless communication technologies are being developed. Representative wireless communication technologies may be long term evolution (LTE), advanced (LTE-A), new radio (NR), etc. specified in the 3rd generation partnership project (3GPP) standard. LTE and/or LTE-A may be 4G (4th Generation) communication technology. NR may be a 5G (5th Generation) communication technology.

In order to process the rapid increase in wireless data after the commercialization of the 4G communication system (e.g., a communication system supporting LTE and/or LTE-A), the frequency band of the 4G communication system (e.g., a frequency band below 6 GHz) ), as well as a 5G communication system (e.g., a communication system supporting NR) that uses a higher frequency band (e.g., a frequency band of 6 GHz or higher) than the frequency band of the 4G communication system is being considered. The 5G communication system may support enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communication (URLLC), and/or massive Machine Type Communication (mMTC).

The 5G communication system can support sidelink communication. In sidelink communication, communication can be performed between terminals. For example, a first terminal may transmit signals, information, and/or data to a second terminal, and the second terminal may receive signals, information, and/or data from the first terminal. Channels for sidelink communication may be Physical Sidelink Broadcast Channel (PSBCH), Physical Sidelink Shared Channel (PSSCH), Physical Sidelink Control Channel (PSCCH), and/or Physical Sidelink Feedback Channel (PSFCH).

The communication system can support communication in unlicensed bands. Channel access procedures may be required for unlicensed band communication. In sidelink communication between terminals, the efficiency of the communication system can be improved depending on the terminal's channel access procedure. Therefore, channel access procedures for terminals in unlicensed band communication are necessary.

Meanwhile, the technology behind the invention was written to improve understanding of the background of the invention, and may include content that is not prior art already known to those skilled in the art in the field to which this technology belongs.

The purpose of the present disclosure to solve the above problems is to provide a method and device for channel access in unlicensed band communication.

A method of a first terminal according to embodiments of the present disclosure for achieving the above object includes receiving shared information of a COT initiated by a second terminal from the second terminal, and receiving shared information from the COT based on the shared information. It includes determining whether the SL transmission of the first terminal can be performed, and if the SL transmission can be performed in the COT, performing the SL transmission in the COT shared by the second terminal.

The shared information may include at least one of source ID, destination ID, CAPC, remaining COT duration, or frequency domain information of the COT.

The COT may be initiated by a type 1 LBT operation of the second terminal, the SL transmission of the first terminal in the COT may be performed based on a type 2 LBT operation, and the type 1 LBT operation may be variable It can be performed in a time interval, and the Type 2 LBT operation can be performed in a fixed time interval.

"If the SL transmission is a unicast SL transmission, the source of the unicast SL transmission is the same as the destination of the second terminal's transmission, and the destination of the unicast SL transmission is the same as the source of the second terminal's transmission ", The unicast SL transmission may be performed in the COT shared by the second terminal.

“If the SL transmission is a groupcast SL transmission and the destination of the groupcast SL transmission is the same as the destination of the second terminal’s transmission,” the groupcast SL transmission is performed in the COT shared by the second terminal. It can be.

“If the SL transmission is a broadcast SL transmission and the destination of the broadcast SL transmission is the same as the destination of the second terminal’s transmission,” the broadcast SL transmission is performed in the COT shared by the second terminal. It can be.

Performing the SL transmission may include transmitting an S-SSB in the COT.

“If the SL transmission is a PSFCH transmission and the PSFCH transmission includes HARQ feedback transmission for the second terminal,” the PSFCH transmission may be performed in the COT shared by the second terminal.

If the resources for the SL transmission belong to the resources of the COT, the SL transmission can be performed in the COT.

A first terminal according to embodiments of the present disclosure for achieving the above object includes at least one processor, wherein the at least one processor allows the first terminal to share information of the COT initiated by the second terminal. Receiving from a second terminal, determining whether SL transmission of the first terminal can be performed in the COT based on the shared information, and if the SL transmission can be performed in the COT, sharing by the second terminal causes the SL transmission to be performed in the COT.

The shared information may include at least one of source ID, destination ID, CAPC, remaining COT duration, or frequency domain information of the COT.

The COT may be initiated by a type 1 LBT operation of the second terminal, the SL transmission of the first terminal in the COT may be performed based on a type 2 LBT operation, and the type 1 LBT operation may be variable It can be performed in a time interval, and the Type 2 LBT operation can be performed in a fixed time interval.

"If the SL transmission is a unicast SL transmission, the source of the unicast SL transmission is the same as the destination of the second terminal's transmission, and the destination of the unicast SL transmission is the same as the source of the second terminal's transmission ", The unicast SL transmission may be performed in the COT shared by the second terminal.

“If the SL transmission is a groupcast SL transmission and the destination of the groupcast SL transmission is the same as the destination of the second terminal’s transmission,” the groupcast SL transmission is performed in the COT shared by the second terminal. It can be.

“If the SL transmission is a broadcast SL transmission and the destination of the broadcast SL transmission is the same as the destination of the second terminal’s transmission,” the broadcast SL transmission is performed in the COT shared by the second terminal. It can be.

When performing the SL transmission, the at least one processor may cause the first terminal to transmit an S-SSB in the COT.

“If the SL transmission is a PSFCH transmission and the PSFCH transmission includes HARQ feedback transmission for the second terminal,” the PSFCH transmission may be performed in the COT shared by the second terminal.

If the resources for the SL transmission belong to the resources of the COT, the SL transmission can be performed in the COT.

According to the present disclosure, the first terminal can initiate a channel occupancy time (COT) and share the COT with the second terminal. If certain condition(s) are satisfied, the second terminal can perform sidelink (SL) transmission in the COT shared by the first terminal. According to the above operation, the channel access efficiency of the terminal in unlicensed band communication can be increased. Therefore, the performance of the communication system can be improved.

1 is a conceptual diagram showing a first embodiment of a communication network.
Figure 2 is a block diagram showing a first embodiment of a communication node constituting a communication network.
Figure 3 is a conceptual diagram showing a first embodiment of a system frame in a communication network.
Figure 4 is a conceptual diagram showing a first embodiment of a subframe in a communication network.
Figure 5 is a conceptual diagram showing a first embodiment of a slot in a communication network.
Figure 6 is a conceptual diagram showing a first embodiment of time-frequency resources in a communication network.
Figure 7 is a conceptual diagram showing a first embodiment of setting a resource pool, SL signal, and SL channel within SL BWP.
Figure 8 is a conceptual diagram showing a first embodiment of SL resources.
Figure 9 is a flowchart showing a first embodiment of a communication method in an unlicensed band.
Figure 10 is a flowchart showing a second embodiment of a communication method in an unlicensed band.
Figure 11 is a flowchart showing a third embodiment of a communication method in an unlicensed band.
Figure 12 is a flowchart showing a fourth embodiment of a communication method in an unlicensed band.

Since the present disclosure can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present disclosure to specific embodiments, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present disclosure.

Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be referred to as a second component, and similarly, the second component may be referred to as a first component without departing from the scope of the present disclosure. The term “and/or” includes any of a plurality of related stated items or a combination of a plurality of related stated items.

In the present disclosure, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B.” Additionally, in the present disclosure, “one or more of A and B” may mean “one or more of A or B” or “one or more of combinations of one or more of A and B.”

In this disclosure, (re)transmit can mean “transmit,” “retransmit,” or “transmit and retransmit,” and (re)set can mean “set,” “reset,” or “set and reset.” can mean “connection,” “reconnection,” or “connection and reconnection,” and (re)connection can mean “connection,” “reconnection,” or “connection and reconnection.” It can mean.

When a component is said to be "connected" or "connected" to another component, it is understood that it may be directly connected to or connected to the other component, but that other components may exist in between. It should be. On the other hand, when it is mentioned that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between.

The terms used in this disclosure are only used to describe specific embodiments and are not intended to limit the disclosure. Singular expressions include plural expressions unless the context clearly dictates otherwise. In the present disclosure, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the technical field to which this disclosure pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless clearly defined in the present disclosure, should not be interpreted in an idealized or excessively formal sense. No.

Hereinafter, preferred embodiments of the present disclosure will be described in more detail with reference to the attached drawings. In order to facilitate overall understanding in explaining the present disclosure, the same reference numerals are used for the same components in the drawings, and duplicate descriptions of the same components are omitted.

A communication network (communication system) to which embodiments according to the present disclosure are applied will be described. The communication networks to which the embodiments according to the present disclosure are applied are not limited to those described below, and the embodiments according to the present disclosure can be applied to various communication networks. Here, communication network may be used in the same sense as communication system. A communication network may refer to a wireless communication network, and a communication system may refer to a wireless communication system.

In the present disclosure, “setting an operation (e.g., a transmission operation)” means “setting information (e.g., information element, parameter) for the operation” and/or “performing the operation.” This may mean that “indicating information” is signaled. “An information element (eg, parameter) is set” may mean that the information element is signaled. In the present disclosure, signaling includes system information (SI) signaling (e.g., transmission of a system information block (SIB) and/or master information block (MIB)), RRC signaling (e.g., RRC parameters and/or upper layer parameters) transmission of), MAC control element (CE) signaling, or PHY signaling (e.g., transmission of downlink control information (DCI), uplink control information (UCI), and/or sidelink control information (SCI)). You can.

1 is a conceptual diagram showing a first embodiment of a communication network.

Referring to FIG. 1, the base station 110 uses cellular communication (e.g., long term evolution (LTE), LTE-A (advanced), and LTE-A Pro defined in the 3rd generation partnership project (3GPP) standard. , LTE-U (unlicensed), NR (new radio), NR-U (unlicensed), etc. The base station 110 supports multiple input multiple output (MIMO) (e.g., single user (SU)-MIMO). , MU (multi user)-MIMO, massive MIMO, etc.), CoMP (coordinated multipoint), carrier aggregation (CA), etc. can be supported.

The first terminal 120 and the second terminal 130 may perform sidelink communication. Sidelink communication can be performed based on mode 1 or mode 2. When mode 1 is used, sidelink communication between the first terminal 120 and the second terminal 130 may be performed using resource(s) allocated by the base station 110. When mode 2 is used, sidelink communication between the first terminal 120 and the second terminal 130 will be performed using the resource(s) selected by the first terminal 120 or the second terminal 130. You can.

Communication nodes (e.g., base stations, terminals, etc.) that make up the communication network described above use a communication protocol based on CDMA (code division multiple access), a communication protocol based on WCDMA (wideband CDMA), and a time division multiple access (TDMA). communication protocol based on FDMA (frequency division multiple access), communication protocol based on single carrier (SC)-FDMA, communication protocol based on orthogonal frequency division multiplexing (OFDM), orthogonal frequency division multiple access (OFDMA) based It can support communication protocols, etc.

Among communication nodes, base stations include NodeB, evolved NodeB, 5g NodeB (gNodeB), base transceiver station (BTS), radio base station, radio transceiver, and access point. It may be referred to as an access point, an access node, a transmission/reception point (Tx/Rx Point), etc. Among communication nodes, terminals include UE (user equipment), access terminal, mobile terminal, station, subscriber station, portable subscriber station, and mobile. It may be referred to as a mobile station, node, device, etc. A communication node may have the following structure.

Figure 2 is a block diagram showing a first embodiment of a communication node constituting a communication network.

Referring to FIG. 2, the communication node 200 may include at least one of at least one processor 210, a memory 220, or a transmitting and receiving device 230 that is connected to a network and performs communication. Additionally, the communication node 200 may further include an input interface device 240, an output interface device 250, a storage device 260, etc. Each component included in the communication node 200 is connected by a bus 270 and can communicate with each other.

However, each component included in the communication node 200 may be connected through an individual interface or individual bus centered on the processor 210, rather than the common bus 270. For example, the processor 210 may be connected to at least one of the memory 220, the transmission/reception device 230, the input interface device 240, the output interface device 250, and the storage device 260 through a dedicated interface. .

The processor 210 may execute a program command stored in at least one of the memory 220 and the storage device 260. The processor 210 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present disclosure are performed. Each of the memory 220 and the storage device 260 may be comprised of at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 220 may be comprised of at least one of read only memory (ROM) and random access memory (RAM).

Next, operating methods of a communication node in a communication network will be described. Even when a method (e.g., transmission or reception of a signal) performed in a first communication node among communication nodes is described, the corresponding second communication node is described as a method (e.g., transmitting or receiving a signal) corresponding to the method performed in the first communication node. For example, reception or transmission of a signal) can be performed. In other words, when the operation of the first terminal (e.g., the transmitting terminal) is described, the corresponding second terminal (e.g., the receiving terminal) can perform an operation corresponding to the operation with the first terminal. there is. Conversely, when the operation of the second terminal is described, the corresponding first terminal may perform an operation corresponding to the operation of the second terminal.

Figure 3 is a conceptual diagram showing a first embodiment of a system frame in a communication network.

Referring to FIG. 3, time resources in a communication network can be divided into frames. For example, in the time domain of a communication network, system frames may be set sequentially. The length of the system frame may be 10ms (millisecond). The system frame number (SFN) can be set to #0 to #1023. In this case, 1024 system frames may be repeated in the time domain of the communication network. For example, the SFN of the system frame after system frame #1023 may be #0.

One system frame may include two half frames. The length of one half frame may be 5ms. The half frame located in the start area of the system frame may be referred to as “half frame #0,” and the half frame located in the end area of the system frame may be referred to as “half frame #1.” A system frame may include 10 subframes. The length of one subframe may be 1ms. Ten subframes within one system frame may be referred to as “subframes #0-9”.

Figure 4 is a conceptual diagram showing a first embodiment of a subframe in a communication network.

Referring to FIG. 4, one subframe may include n slots, and n may be a natural number. Therefore, one subframe may consist of one or more slots.

Figure 5 is a conceptual diagram showing a first embodiment of a slot in a communication network.

Referring to FIG. 5, one slot may include one or more symbols. One slot shown in FIG. 5 may include 14 symbols. The length of a slot may vary depending on the number of symbols included in the slot and the length of the symbol. Alternatively, the length of the slot may vary depending on numerology. If the subcarrier spacing is 15 kHz (eg, μ=0), the length of the slot may be 1 ms. In this case, one system frame may include 10 slots. If the subcarrier spacing is 30 kHz (eg, μ=1), the length of the slot may be 0.5 ms. In this case, one system frame may include 20 slots.

If the subcarrier spacing is 60 kHz (eg, μ=2), the length of the slot may be 0.25 ms. In this case, one system frame may include 40 slots. If the subcarrier spacing is 120 kHz (eg, μ=3), the length of the slot may be 0.125 ms. In this case, one system frame may include 80 slots. If the subcarrier spacing is 240 kHz (eg, μ=4), the length of the slot may be 0.0625 ms. In this case, one system frame may include 160 slots.

Figure 6 is a conceptual diagram showing a first embodiment of time-frequency resources in a communication network.

Referring to FIG. 6, a resource consisting of one symbol (eg, OFDM symbol) in the time domain and one subcarrier in the frequency domain may be defined as a “resource element (RE).” Resources consisting of one OFDM symbol in the time domain and K subcarriers in the frequency domain can be defined as a “resource element group (REG).” REG may contain K REs. REG can be used as a basic unit of resource allocation in the frequency domain. K may be a natural number. For example, K could be 12. N may be a natural number. In the slot shown in FIG. 5, N may be 14. N OFDM symbols can be used as a basic unit of resource allocation in the time domain.

Methods for transmitting and receiving data in a communication network will be described. In downlink communication, downlink data may be transmitted through a physical downlink shared channel (PDSCH). In uplink communication, uplink data may be transmitted through a physical uplink shared channel (PUSCH). In the present disclosure, PDSCH may refer to downlink data or a resource through which the downlink data is transmitted and received, and PUSCH may refer to uplink data or a resource through which the uplink data is transmitted and received. The base station may transmit downlink control information (DCI) including PDSCH configuration information (e.g., resource allocation information, scheduling information) through a physical downlink control channel (PDCCH). In the present disclosure, PDCCH may mean DCI (eg, control information) or a resource on which the DCI is transmitted.

The terminal can receive DCI from the PDCCH and check the configuration information of the PDSCH included in the DCI. For example, the configuration information of the PDSCH may include time domain resource assignment (TDRA), frequency domain resource assignment (FDRA), and/or modulation and coding scheme (MCS) information. TDRA may indicate the resource area of PDSCH in the time domain. FDRA can indicate the resource area of PDSCH in the frequency domain. MCS information may be MCS level or MCS index.

Sidelink (SL) communication can be performed in a communication network. SL communication may be performed in licensed and/or unlicensed bands. SL communication in the unlicensed band may be referred to as sidelink-unlicensed (SL-U) communication or unlicensed-sidelink (U-SL) communication. SL resources may be used for transmission of SL signals and/or channels. SL resources can be set on a resource pool basis. The resource pool may be referred to as an SL resource pool. The resource pool may include a Tx resource pool and/or an Rx resource pool. The Tx resource pool can be used for SL transmission, and the Rx resource pool can be used for SL reception. Tx resource pool and Rx resource pool can be distinguished from each other. The Tx resource pool and Rx resource pool can be set independently. In the present disclosure, SL transmission may be one of unicast SL transmission, groupcast SL transmission, multicast SL transmission, or broadcast SL transmission.

In the time domain, a resource pool may include one or more slots, and in the frequency domain, a resource pool may include one or more subchannels. One subchannel may include N _PRB physical resource blocks (PRBs). N _PRB can be one of 10, 12, 15, 20, 25, 50, 75, or 100. Resource pools can be set up periodically. For example, a resource pool can be set to a period of 10240ms (millisecond) in the time domain. Among all slots belonging to the section corresponding to the period of 10240ms, some slots may be set as a resource pool. Depending on the time division duplex (TDD) configuration, slot(s) containing a downlink (DL) symbol may not be set to a resource pool. Slot(s) containing resources that can transmit a sidelink-synchronization signal block (S-SSB) may not be set to a resource pool. Slot(s) that can be configured as a resource pool can be defined as a bitmap. In other words, the bitmap can indicate slot(s) that can be configured as a resource pool.

The SL channel may be used for transmission and reception of traffic (e.g., data), management information, and/or control information (e.g., control information related to scheduling) related to the SL service. The SL channel may include a Physical Sidelink Broadcast Channel (PSBCH), a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Control Channel (PSCCH), and/or a Physical Sidelink Feedback Channel (PSFCH). The SL signal may be a synchronization signal (e.g., sidelink-primary synchronization signal (S-PSS), sidelink-secondary synchronization signal (S-SSS)) and/or a reference signal (e.g., demodulation reference signal (DMRS), CSI -May include channel state information-reference signal (RS), phase tracking (PT)-RS, and positioning reference signal (PRS).

PSSCH may be a channel used for transmission and reception of transport block (TB), data, and/or traffic. PSCCH may be a channel used for transmitting and receiving control information. PSFCH may be a channel used for transmission and reception of HARQ (hybrid automatic repeat request) feedback indicating the reception status of PSSCH. S-SSB may include at least one of PSBCH, S-PSS, or S-SSS. S-SSB may further include DMRS. Synchronization between terminals may be performed using synchronization signals (eg, S-PSS and/or S-SSS).

Figure 7 is a conceptual diagram illustrating a first embodiment of setting a resource pool, SL signal, and SL channel within an SL BWP (bandwidth part).

Referring to FIG. 7, the resource pool includes one or more slots excluding “slot(s) that do not meet the setting conditions of the resource pool” and/or “slot(s) not indicated by the bitmap” among a plurality of slots. may include. Discontinuous slots in the time domain can be interpreted as continuous slots within a resource pool. In other words, even if the slots set to the resource pool are not consecutive, the indexes of the slots within the resource pool may be consecutive.

In the present disclosure, SL resources (eg, SL transmission resources) may refer to resources within a resource pool. SL resources may refer to resources for transmission of SL signals and/or SL channels. In the present disclosure, signal transmission may mean transmission of an SL signal and/or SL channel, and signal reception may mean reception of an SL signal and/or SL channel. “Signal” can be interpreted as “signal” or “signal + channel”, and “channel” can be interpreted as “channel” or “channel + signal”. SL signal/channel can be interpreted as “SL signal”, “SL channel”, or “SL signal + SL channel”.

Figure 8 is a conceptual diagram showing a first embodiment of SL resources.

Referring to FIG. 8, the basic transmission unit of an SL signal/channel in the time domain may be one slot, and the basic transmission unit of an SL signal/channel in the frequency domain may be one subchannel. The transmission resource of the SL signal/channel may include one or more slots and/or one or more subchannels. Transmission resources may include PSCCH and/or PSSCH. Additionally, transmission resources may include PSFCH. A slot containing the PSFCH (eg, slot location) may be predefined. A slot containing PSFCH may be referred to as a PSFCH slot. The setting conditions of the PSFCH slot in the licensed band may be different from the setting conditions of the PSFCH slot in the unlicensed band. The transmission operation of HARQ feedback in the PSFCH slot of the licensed band may be different from the transmission operation of HARQ feedback in the PSFCH slot of the unlicensed band. The configuration information of the SL channel actually transmitted in the transmission resource may be transmitted through signaling (e.g., RRC message, SCI). The configuration information of the SL channel may include frequency resource information (e.g., location of the frequency resource area), time resource information (e.g., location of the time resource area), etc.

SL resources can be allocated based on mode 1 or mode 2. Mode 1 may be referred to as resource allocation (RA)-mode 1, and mode 2 may be referred to as RA-mode 2. When RA-mode 1 is used, the base station may transmit a DCI (e.g., SL grant) containing SL resource allocation information to the terminal, and the terminal performs SL communication using the SL resources allocated by the base station. can do. When RA-mode 2 is used, the terminal can perform a resource sensing operation within the resource pool, perform a resource selection operation for the resources sensed by the resource sensing operation, and select the resource selected by the resource selection operation. SL communication can be performed using resources.

In RA-mode 1, when transmission data occurs, the terminal can transmit a scheduling request (SR) for the transmission data to the base station, and the base station uses a dynamic grant (DG) based on the SR of the terminal. Resources (eg, SL resources) can be allocated to the terminal. In RA-mode 1, the base station can allocate periodic resources to the terminal in a semi-static manner, and the terminal can perform SL communication using the periodic resources allocated by the base station.

A periodic resource allocated in a quasi-static manner may be a configured grant (CG) resource. The base station may transmit allocation information of CG resources to the terminal. Allocation information of CG resources may include at least one of location information of CG resources, time resource information of CG resources, frequency resource information of CG resources, or period information of CG resources. Depending on the release procedure or deactivate procedure of CG resources, CG methods can be classified into CG-Type 1 and CG-Type 2. In CG-Type 1, CG resources can be released by RRC signaling. In CG-Type 2, CG resources can be deactivated by DCI signaling.

In RA-mode 2, the terminal can perform a resource sensing operation during the sensing window, select resource(s) that satisfy predefined conditions among the resources sensed by the resource sensing operation, and select the selected resource(s) You can transmit SL signals/channels using . Resource sensing/selection methods according to RA-mode 2 can be classified into dynamic methods and semi-static methods. According to the quasi-static method, specific time resources can be occupied. Dynamic methods and semi-static methods can be distinguished depending on the time of selection of new resources. When the dynamic method is used, the UE can select resources for TB transmission every time it wants to transmit a new TB. TB transmission may include “new TB transmission (e.g., first TB transmission)” and/or “TB retransmission”. One or more resources (e.g., one or more transmission resources) may be used, occupied, and/or reserved for TB transmission.

If a quasi-static method is used, the counter value of TB transmission during a specific time (eg, resource reservation interval (RRI)) may be 0. Alternatively, if a quasi-static method is used, a new transmission resource may be selected under certain conditions. The counter value of TB transmission may be selected randomly. The selected counter value may be decreased by 1 when one TB transmission (e.g., new TB transmission and/or TB retransmission) is completed. When a quasi-static method is used, the terminal can continue to occupy the selected resource during a specific time. In other words, the terminal can continue to use the selected resource during a specific time. The specific time may mean a time that the terminal can exclusively occupy. A specific time can be defined as RRI.

The base station can signal the RRI list to the terminal. The RRI list may include up to 16 RRIs (eg, up to 16 RRI values). The signaling may be at least one of system information (SI) signaling, RRC signaling, MAC CE signaling, or PHY signaling. The terminal may receive an RRI list from the base station, select one RRI among RRIs belonging to the RRI list, and use the selected resource (eg, selected transmission resource) during the selected RRI. The terminal can occupy consecutive resources during RRI. Consecutive resources can be set in a logical resource area for SL.

The first terminal may transmit an SCI containing information of the selected RRI to the second terminal. The second terminal can receive the SCI from the first terminal and confirm the RRI selected by the first terminal based on the information element included in the SCI. The second terminal may not select a resource (eg, a resource selected by the first terminal) during RRI indicated by the SCI. Information on the resource selected by the first terminal may be included in the SCI.

When RA-mode 2 is used, a resource sensing window and/or a resource selection window can be set. A resource sensing window may be referred to as a sensing window (SSW), and a resource sensing operation may be performed within the SSW. The resource selection window may be referred to as a selection window (SLW), and the resource selection operation may be performed within the SLW. Resources used during RRI (eg, RRI value) indicated by the SCI can be confirmed by a resource sensing operation performed in the SSW.

Sidelink control information (SCI) may include scheduling information (e.g., scheduling information of the TB) and/or parameter(s) applicable to TB transmission. Parameter(s) applied to TB transmission can be used by demodulating/decoding the TB in the receiving terminal. SCI can be classified into level 1 SCI ( ^1st SCI) and level 2 SCI ( ^2nd SCI). Level 1 SCI can be transmitted on PSCCH, and level 2 SCI can be transmitted on PSSCH. A level 2 SCI can be linked to a level 1 SCI. Phase 1 SCI may include scheduling information for initial TB transmission and/or scheduling information for TB retransmission. Step 2 SCI may include at least one of PSSCH transmitting terminal information, PSSCH receiving terminal information, HARQ feedback information, or retransmission information.

Y transmission resources including slots in which phase 1 SCI is transmitted can be set. Y can be a natural number. For example, Y can be 2 or 3. The first transmission resource among Y transmission resources can be set in the slot where the first-level SCI is transmitted. In other words, the first transmission resource among the transmission resources may be a slot in which the first level SCI is transmitted. The slot(s) in which (Y-1) transmission resources are configured may be defined by slot offset(s). The slot offset can be a positive integer. The maximum value of the slot offset may be 32.

The scheduled first transmission resource may include N _subchannels in the frequency domain. The first subchannel (eg, start subchannel) among the N _subchannels may be a subchannel through which the first-level SCI is transmitted. N _subchannel can be a natural number. N _subchannels can be set to less than the maximum number of subchannels set by higher layer signaling. Step 1 SCI is the frequency resource information of the second transmission resource (e.g., information of the N subchannel(s), information of the start subchannel among the N subchannel(s)) and/or the frequency of the third transmission resource. It may include resource information (e.g., information on N subchannel(s), information on a start subchannel among N subchannel(s)). The number of subchannels (N) of the second transmission resource may be the same as the number of subchannels (N _subchannel ) of the first transmission resource. The number of subchannels (N) of the third transmission resource may be the same as the number of subchannels (N _subchannel ) of the first transmission resource. The first transmission resource among the Y transmission resources may be a transmission resource for the first TB transmission (eg, first TB transmission). The remaining (Y-1) transmission resource(s) may be transmission resource(s) for TB retransmission.

A level 1 SCI may include one or more information elements defined in Table 1 below.

A level 2 SCI may contain one or more information elements. Information elements included in the level 2 SCI may vary depending on the format of the level 2 SCI. A level 2 SCI may include one or more information elements defined in Table 2 below.

PSFCH may be configured periodically within the SL resource area. The slot in which the PSFCH is configured may be referred to as a PSFCH slot. PSFCH slots can be set according to the cycle. The period of the PSFCH slot may be referred to as PSFCH transmission occasion resource (TPR). PSFCH TPR can be defined on a slot basis within the resource pool. PSFCH TRP may be 1 slot, 2 slots, or 4 slots. PRB(s) capable of transmitting PSFCH in the frequency domain may be indicated by a bitmap. PRBs available for PSFCH transmission may be all PRBs or some PRBs. One PSFCH can be transmitted in one PRB. Alternatively, in the unlicensed band, one PSFCH may be transmitted on one or more PRBs.

The PRB(s) through which the PSFCH is transmitted may be determined based on the location of the slot in which the PSSCH associated with the PSFCH is received. The difference (eg, slot offset, interval) between the slot in which the PSSCH is received and the slot in which the PSFCH is to be transmitted may be considered. For example, the PSFCH may be transmitted in the first PSFCH slot after K slot(s) starting from slot n in which the PSSCH was received. The PRB index (eg, the index of the PRB through which the PSFCH is transmitted) may be defined based on the function f(P _PSFCH , n, K, k _subch ). P _PSFCH may be the period of PSFCH. n may be the index of the slot in which the PSSCH was received. K may be a slot offset used to determine the PSFCH slot in which the PSFCH is transmitted. k _subch may be the index of the subchannel on which the PSCCH is configured.

In the function f(.) for determining the PRB index, at least one of a different code (q), the ID (identifier) of the transmitting terminal, or the ID of the receiving terminal transmitting the PSFCH may be considered. Code (q) may be defined by a cyclic shift or a cyclic shift pair. Cyclic shifts can be related to different Zadoff-Chu sequences. A cyclic shift pair may refer to a pair of different sequences according to acknowledgment (ACK) or negative ACK (NACK).

The PRB set through which the PSFCH is transmitted may be determined based on slot #n through which the PSSCH is transmitted and/or the index of the subchannel through which the PSSCH is transmitted. The code delivered to the PRB and PSFCH in the PRB set may be determined based on a function that considers at least one of the ID of the transmitting terminal or the ID of the receiving terminal transmitting the PSFCH.

The base station may transmit configuration information (e.g., transmission resource information) of the SL channel(s) to the terminal. The terminal may receive configuration information of the SL channel(s) from the base station and transmit the SL channel(s) based on the configuration information (eg, transmission resources indicated by the configuration information). Alternatively, the terminal may select resource(s) by performing a resource sensing operation and/or a resource selection operation, and may transmit SL channel(s) on the selected resource(s). The selected resource(s) may mean transmission resource(s). Transmission resources may include one or more subchannels and one or more slots.

The transmitting terminal may transmit an SCI including transmission resource information (eg, scheduling information) of the PSSCH to the receiving terminal. Transmission resource information may be allocation information of subchannel(s) and/or slot(s) of PSSCH. A transmitting terminal may refer to a terminal that transmits PSSCH (eg, data). A receiving terminal may refer to a terminal that receives PSSCH (eg, data). Transmission resource information included in the SCI may indicate the transmission resource of PSSCH in the slot in which the SCI is transmitted. Alternatively, transmission resource information included in the SCI may indicate transmission resources of the PSSCH in a slot other than the slot in which the SCI is transmitted.

In SL-U communication, a listen-before-talk (LBT) operation may be performed for coexistence with other communication nodes (eg, communication devices). Actual transmission resources may be determined based on the results of LBT operation. The terminal can perform an LBT operation, and if the LBT operation is successful, it can use the channel for a specific time (eg, channel occupancy time (COT)). For example, if the LBT operation of the terminal is successful, COT may be initiated by the terminal, and the terminal may perform communication (eg, SL-U communication) during the COT. Depending on certain conditions, other terminals (e.g., terminals that have not initiated COT) may perform communication (e.g., SL-U communication) during COT. In other words, the COT can be shared with other terminal(s), and in this case, the other terminal(s) can perform communication within the shared COT.

Within the COT, the transmission unit (e.g., symbol setting) may vary. Within COT, transmission unit configuration information may be transmitted through signaling (eg, SCI). The symbol may refer to an OFDM symbol. In the embodiment of FIG. 8, PSCCH and PSSCH may be set together within transmission resources. PSCCH may be set starting from the PRB with the lowest index in the subchannel with the lowest index among the subchannel(s) configured for PSSCH transmission.

Operations, procedures, control information, and/or configuration information for operating channel occupancy in SL-U communication will be described. An operating channel may refer to a frequency resource having a bandwidth of a predefined size. Resources (e.g., time resources, frequency resources, carriers, subcarriers, subchannels) of unlicensed bands are used in networks other than cellular networks (e.g., 4G networks, 5G networks) (e.g., WLAN (wireless local area networks). It can be occupied by a communication node belonging to an area network). Resources in the unlicensed band may be occupied by signals/channels transmitted and received between a base station and a terminal belonging to a cellular network. Resources in the unlicensed band may be occupied by signals/channels transmitted and received between terminals belonging to the cellular network.

In the present disclosure, a communication node (e.g., base station, terminal) transmitting a signal/channel may be expressed as a transmitting node, and a communication node (e.g., base station, terminal) receiving a signal/channel may be expressed as a receiving node. It can be expressed as In the unlicensed band, communication nodes can share an operating channel. LBT operation may be performed to minimize interference between communication nodes. The LBT operation may include checking whether the operating channel is occupied by another signal before transmitting the signal/channel. If LBT operation is supported, a communication node (eg, transmitting node) may perform a random backoff procedure.

If the LBT operation is successful, the communication node can occupy the operating channel. Occupancy of an operating channel may be referred to as channel occupancy (CO). The terminal can secure CO by performing LBT operation. CO settings may vary depending on the type of LBT operation performed by the terminal. For example, the maximum length of CO may vary depending on the type of LBT operation performed by the UE. The type of LBT operation performed by the terminal may vary depending on the priority class of the data the terminal wishes to transmit within the CO. The priority class may be channel access priority class (CAPC).

The UE may perform an LBT operation using different parameters (eg, different LBT parameters) to obtain a CO corresponding to each priority class. When the LBT operation is performed according to the priority class, the parameters that determine the performance time of the LBT operation may vary. In LBT operation involving a random backoff procedure, the minimum and/or maximum size of the contention window (CW) may be set differently for each priority class. The UE can select a random backoff counter within the CW and perform a random backoff procedure based on the selected random backoff counter.

The fixed time interval in which the LBT operation is performed may be determined based on the type of LBT operation and/or LBT parameter(s). The length of the fixed time interval may be 16 μs or 25 μs. A communication node (e.g., transmitting node) that performed an LBT operation may transmit CO information (e.g., CO setting information) obtained by the LBT operation to another communication node (e.g., receiving node). there is. CO configuration information may include LBT parameter(s) used for LBT operation of the terminal. LBT parameter(s) may include information of priority class. CO setting information may include at least one of CO start point information, CO length information, or CO end point information. In the present disclosure, time point may be interpreted as time.

The receiving node may receive CO configuration information from the transmitting node and confirm the LBT parameter(s) used for acquisition of CO based on the CO configuration information. The receiving node may confirm the priority class for the CO initiated by the transmitting node based on the LBT parameter(s). The receiving node can confirm the CO initiated by the transmitting node based on the CO configuration information and perform communication within the CO. For example, a receiving node can transmit and receive signals/channels within a CO.

The transmitting node can set COT (channel occupancy time). COT establishment may mean COT initiation. COT may be set within time resources and/or frequency resources. COT may be set within one or more resource blocks (RBs) or one or more RB sets. COT configuration information may indicate time resources and/or frequency resources for which the COT is configured. The frequency resource of the COT may include one or more RBs or one or more RB sets. COT may be referred to as CO or COR (channel occupancy resource). In the unlicensed band, resources can be shared by multiple communication nodes. A communication node may use discontinuous resources (eg, discontinuous time resources and/or discontinuous frequency resources). In this case, signal/channel transmission in the unlicensed band may be performed in a discontinuous burst manner. The burst method may refer to transmission performed on transmission resources including one or more slots.

Signals/channels can be transmitted in times with a length shorter than a slot. A time with a length shorter than a slot may include consecutive symbols. A time with a length shorter than a slot may be a mini slot. Consecutive transmission resources within the COT can be configured. The transmitting node may transmit an initial signal and/or a burst signal (eg, PSSCH, PSFCH, PSCCH, reference signal) within the COT. The initial signal may be a copied signal of the signal in the first symbol on which SL transmission is performed. Alternatively, the initial signal may be a signal composed of a cyclic prefix (CP).

In SL-U communication, the terminal can perform LBT operation before transmitting the signal/channel. If the result of the LBT operation is idle, the terminal can transmit a signal/channel. If the result of the LBT operation is busy, the terminal may not transmit the signal/channel. “The result of the LBT operation is children” may mean “the LBT operation is successful.” “The result of the LBT operation is busy” may mean “the LBT operation failed.” Based on the result of comparison between the energy detection level and the predefined threshold, the result of the LBT operation can be determined as idle or busy.

LBT operation can be classified into type 1 LBT operation and type 2 LBT operation. In type 1 LBT operation, channel sensing time may be variable. In other words, type 1 LBT operation can be performed in a variable time interval. Channel sensing time can be changed by random variables. Type 1 LBT operation may refer to LBT operation involving a random backoff procedure. In type 2 LBT operation, the channel sensing time may be fixed. In other words, type 2 LBT operation can be performed in a fixed time interval. The channel sensing time may be m ㎲. m may be a natural number.

When a type 1 LBT operation is performed, the terminal can randomly select the value (N) according to equal probability within the CW. The value (N) may be an integer. Value (N) may be a random backoff counter. The terminal may perform a channel sensing operation in a predefined sensing interval (eg, sensing slot interval). A channel sensing operation may mean an energy detection operation for time and/or frequency resource(s). If the result of the channel sensing operation in one sensing period is idle, the terminal may decrease the value (N) selected in the CW by 1. If the result of the channel sensing operation in one sensing period is busy, the terminal can additionally perform the channel sensing operation. If the result of the channel sensing operation in N sensing sections is idle, the terminal can transmit a signal/channel.

The terminal can perform a channel access procedure to use the unlicensed band. The channel access procedure may be an LBT operation. The terminal can obtain COT by performing a channel access procedure. In other words, if the terminal's channel access procedure is successful, the terminal can initiate COT. In this disclosure, “the terminal has acquired the COT” may mean “the terminal has initiated the COT” and/or “the terminal has set the COT.” The terminal may perform an LBT operation (eg, type 1 LBT operation) to obtain COT. The terminal can acquire COT when the type 1 LBT operation is successful. The terminal can acquire COT by performing a semi-static channel access procedure.

The LBT operation (e.g., type of LBT operation) performed by the terminal for transmission of a signal/channel within the COT is the LBT operation (e.g., type of LBT operation) performed by the terminal for transmission of a signal/channel outside of the COT. type) may be different. The terminal can perform type 2 LBT operation for signal/channel transmission within the COT. Type 2 LBT operation can be performed in a fixed time interval. The terminal can perform type 1 LBT operation for signal/channel transmission outside of the COT. Type 1 LBT operation can be performed in a variable time interval.

The terminal can share the acquired COT or initiated COT with other terminals. The operation may be a COT sharing operation. In the present disclosure, a terminal sharing the acquired COT or initiated COT with another terminal may be referred to as “Terminal A,” and the terminal sharing the acquired COT or initiated COT with another terminal may be referred to as “Terminal B.” You can. Additionally, terminal A may be referred to as a first terminal or a second terminal, and terminal B may be referred to as a second terminal or a first terminal.

Terminal A can perform LBT operation using different LBT parameters depending on the priority class of data. Depending on the priority class, LBT parameters (e.g., contention window, length of the sensing interval (e.g., sensing window)) used for LBT operation may vary. The priority class may be selected by terminal A. The maximum length of COT may vary depending on the result of LBT operation according to priority class. The priority class may mean channel access priority class (CAPC).

Terminal A can acquire COT according to the results of the LBT operation. If the LBT operation is successful, terminal A can acquire COT. If the LBT operation fails, terminal A may not be able to obtain COT. Terminal A can transmit signals/channels within COT. Terminal A's transmission within the COT may be SL (sidelink) transmission or UL (uplink) transmission. Terminal A may transmit the acquired COT information (e.g., COT setting information, COT sharing information) to terminal B. COT setting information and COT sharing information may be the same information. COT setting information may be CO setting information, and COT sharing information may be CO sharing information. Terminal B can receive information on the COT initiated by Terminal A from Terminal A and transmit a signal/channel within the COT initiated by Terminal A.

Figure 9 is a flowchart showing a first embodiment of a communication method in an unlicensed band.

Referring to Figure 9, terminal A can acquire COT (S910). For example, terminal A can acquire COT by performing an LBT operation (eg, type 1 LBT operation). Terminal A may transmit the acquired COT information (e.g., COT setting information, COT sharing information) to terminal B (S920). COT configuration information (eg, COT sharing information) may be transmitted via MAC CE and/or SCI. In other words, terminal A can transmit MAC CE including COT configuration information to terminal B. MAC CE can be transmitted through PSSCH scheduled by SCI. Alternatively, terminal A may transmit an SCI containing COT configuration information to terminal B. COT configuration information may include one or more information elements defined in Table 3 below.

The source ID may be the source ID (for example, the ID or address of terminal A) for the transmission of terminal A in the COT. The destination ID may be a destination ID (e.g., ID of a specific terminal (e.g., ID or address of terminal B), groupcast ID, broadcast ID) for transmission of terminal A within the COT. The groupcast ID may be a groupcast address, and the broadcast ID may be a broadcast address.

The CAPC may be the CAPC for Terminal A's transmission within the COT. Frequency domain information may be frequency resource information (eg, frequency resource allocation), and time domain information may be time resource information (eg, time resource allocation). A sharing indicator (e.g., COT sharing indicator, CO sharing indicator) may indicate whether to share the COT initiated by terminal A. The shared offset may be an offset from the transmission time (e.g., reception time) of the COT configuration information to the start time when the shared COT is available. The shared offset can be set on a slot basis.

Terminal B can receive COT configuration information from terminal A. Terminal B can check the information element(s) included in the COT setting information (S930). Terminal B can confirm the COT initiated by terminal A based on COT setting information. Terminal B can check whether COT is available (S940). If the COT initiated by terminal A is available, terminal B can transmit a signal/channel within the COT (S950). “If terminal A indicates COT sharing” and/or “if communication of terminal B is possible within the remaining CO duration (e.g., remaining COT duration),” terminal B determines that the COT initiated by terminal A is available. It can be judged that

The remaining CO duration may indicate the interval from the time UE A transmits COT configuration information including information on the remaining CO duration to the end time of COT (e.g., COT associated with the COT configuration information). The remaining CO duration can be indicated on a slot basis. For example, if "COT configuration information is transmitted in slot #N-M, and the COT associated with the COT configuration information ends in slot #N", terminal A may inform terminal B of the remaining CO duration indicating M. . Alternatively, terminal A may inform terminal B of the remaining CO duration indicating at least one of M-1, M, or M+1. Terminal B can receive information on the remaining CO duration from Terminal A, and can check the end time of COT based on the remaining CO duration. Terminal B can check the interval from the reception time of COT setting information including information on the CO duration to the end time of COT associated with the COT setting information based on the remaining CO duration. Terminal B can check the length of the remaining section within the COT initiated by Terminal A based on the remaining CO duration.

If the section required for transmission of terminal B's signal/channel belongs to the remaining CO duration (e.g., the remaining section within the COT), terminal B may transmit the signal/channel within the COT shared by terminal A. . If the interval required for transmission of UE B's signal/channel is longer than the remaining CO duration (e.g., the remaining section within the COT), Terminal B will not transmit the signal/channel within the COT shared by Terminal A. You can. In this case, terminal B can acquire a separate COT and transmit signals/channels within the obtained COT.

COT configuration information transmitted by terminal A may include shared offset information. The shared offset may be an offset from the transmission time (e.g., reception time) of the COT configuration information to the start time when the shared COT is available. The shared offset can be set on a slot basis. Terminal B can receive COT configuration information from terminal A and check the shared offset included in the COT configuration information. Terminal B can check the start time when the COT shared by Terminal A is available based on the shared offset. Terminal B can check the available section of the shared COT based on the start time when the shared COT is available.

If the section required for transmission of terminal B's signal/channel falls within the available section of the shared COT, terminal B can transmit the signal/channel within the COT shared by terminal A. If the interval required for transmission of Terminal B's signal/channel is longer than the available interval of the shared COT, Terminal B may not transmit the signal/channel within the COT shared by Terminal A. In this case, terminal B can acquire a separate COT and transmit signals/channels within the obtained COT.

COT configuration information transmitted by terminal A may include frequency domain information (eg, frequency domain information of COT). The frequency domain information of the COT may indicate the frequency resource (e.g., frequency domain) through which the signal/channel of UE A is transmitted. COT configuration information including frequency domain information may be transmitted through the frequency resource through which the signal/channel of terminal A is transmitted. Terminal B can receive COT configuration information from Terminal A and check the frequency domain information included in the COT configuration information. Terminal B can check the frequency resources of the COT shared by Terminal A based on frequency domain information.

If the frequency resources required for transmission of terminal B's signal/channel belong to the frequency resources of the shared COT, terminal B can transmit the signal/channel within the COT shared by terminal A. If the frequency resources required for transmission of terminal B's signal/channel are greater than the frequency resources of the shared COT, terminal B may not transmit the signal/channel within the COT shared by terminal A. In this case, terminal B can acquire a separate COT and transmit signals/channels within the obtained COT.

COT configuration information transmitted by terminal A may include information on priority class (eg, CAPC). Information on the priority class may be an index indicating the priority class. Terminal B can receive COT configuration information from terminal A and check priority class information included in the COT configuration information. Terminal B can confirm the priority class of the COT (eg, COT shared by Terminal A) based on priority class information. The priority class of the COT may be CAPC for the COT. Terminal B can check the priority class of data that can be transmitted within the COT based on the priority class of the COT.

“If the priority class of the signal/channel (e.g., data) of terminal B is the same as the priority class indicated by the COT setting information,” or “the priority of the signal/channel (e.g., data) of terminal B If the priority class is higher than the priority class indicated by COT configuration information, terminal B can transmit a signal/channel within the COT shared by terminal A. Alternatively, "if the priority class of terminal B's signal/channel (e.g., data) is the same as the priority class indicated by the COT configuration information" or "if terminal B's signal/channel (e.g., data) If the priority class of data) is lower than the priority class indicated by COT configuration information, terminal B can transmit a signal/channel within the COT shared by terminal A.

If the priority class of the signal/channel (e.g., data) that Terminal B wants to transmit meets the conditions of the priority class of COT (e.g., COT shared by Terminal A), Terminal B is connected to the COT Signals/channels can be transmitted in . If the priority class of the signal/channel (e.g., data) that terminal B wants to transmit does not meet the conditions of the priority class of the COT (e.g., the COT shared by terminal A), terminal B Signals/channels may not be transmitted within COT. In this case, terminal B can acquire a separate COT and transmit signals/channels within the obtained COT.

COT setting information transmitted by terminal A may include sharing target information. The sharing target information may indicate the target (eg, terminal) with which the COT is shared. The sharing target information may include location information of a terminal capable of sharing COT. For example, the sharing target information may include location information of terminal A. Terminal(s) located around terminal A can share the COT initiated by terminal A. The shared target information may include information on the communication distance requirements of terminal A. Information on communication distance requirements may indicate the coverage of terminal A. The sharing target information may include at least one of terminal A's location information or terminal A's communication distance requirement information.

Terminal B can receive COT setting information from terminal A and check sharing target information included in the COT setting information. Terminal B can check the coverage of terminal A based on the shared target information. If terminal B is located within the coverage of terminal A, terminal B can transmit signals/channels in the COT shared by terminal A. In other words, the COT initiated by terminal A can be shared with terminal B. If terminal B is not located within the coverage of terminal A, terminal B cannot transmit signals/channels in the COT shared by terminal A. In other words, the COT initiated by terminal A may not be shared by terminal B.

The COT initiated by terminal A can be shared with terminal B, and terminal B can perform communication using the COT. Terminal B can transmit a signal/channel to terminal A within the COT shared by terminal A. In other words, the destination of the signal/channel transmitted by terminal B within the COT shared by terminal A may include terminal A. Terminal B cannot transmit signals/channels within the COT shared by Terminal A to a terminal other than Terminal A. In other words, within the COT shared by terminal A, signal/channel transmission to a destination other than the destination including terminal A may not be performed.

The sharing target information included in the COT setting information may include information on terminal(s) that can share the COT initiated by terminal A. Information on the terminal(s) capable of sharing the COT initiated by terminal A may include at least one of a source ID or a destination ID associated with terminal A's transmission. The source ID may be an ID or address associated with the terminal transmitting the signal/channel. The reception ID may be an ID or address associated with the terminal receiving the signal/channel. When terminal A transmits a signal/channel to terminal B, the source ID may indicate terminal A, and the destination ID may indicate terminal B.

Terminal A may transmit sharing target information (eg, source ID and/or destination ID) to terminal B. Interpretation of the source ID and/or destination ID may vary depending on the transmission method of terminal A (eg, unicast transmission, groupcast transmission, broadcast transmission). Terminals that can share COT may vary depending on source ID and/or destination ID.

When unicast SL communication is performed between terminal A and terminal B, the source ID may be the ID of terminal A, and the destination ID may be the ID of terminal B. Terminal B, which has the same ID as the destination ID indicated by the sharing target information, can transmit a signal/channel within the COT shared by terminal A, which has the source ID indicated by the sharing target information. "The COT initiated by terminal A is shared with terminal B, the source ID of terminal B's SL transmission within the shared COT is the ID of terminal B, and the destination ID of terminal B's SL transmission within the shared COT is the above If it is the ID of terminal A, terminal B can transmit a signal/channel within the shared COT.

When groupcast SL communication or broadcast SL communication is performed between terminal A and terminal B, the source ID may be the ID of terminal A, and in groupcast SL communication, the destination ID may be the ID of the group receiving the groupcast SL transmission or It may be an address, and in broadcast SL communication, the destination ID may be the ID or address of the group receiving the broadcast SL transmission. “If terminal B receives a groupcast SL transmission from terminal A in the COT initiated by terminal A, and the COT is shared with the terminal B,” the terminal B receives the “above” in the COT shared by terminal A. “Groupcast SL transmission with the same destination ID as the groupcast SL transmission of terminal A” or “groupcast SL transmission for the group including the terminal A” can be performed. When terminal A shares the COT for groupcast SL transmission with terminal B, terminal B "transmits groupcast SL with the same destination ID as the groupcast SL transmission" in the COT shared by terminal A, or “Groupcast SL transmission for the group including the terminal A” can be performed.

“If terminal B receives a broadcast SL transmission from terminal A in the COT initiated by terminal A, and the COT is shared with the terminal B,” the terminal B receives the “above” in the COT shared by terminal A. “Broadcast SL transmission with the same destination ID as the broadcast SL transmission of terminal A” or “broadcast SL transmission for a group including the terminal A” can be performed. When terminal A shares the COT for broadcast SL transmission with terminal B, terminal B "transmits a broadcast SL with the same destination ID as the broadcast SL transmission" in the COT shared by terminal A, or “Broadcast SL transmission for the group including the terminal A” may be performed.

Terminal A may transmit COT setting information including sharing target information to terminal B. The shared target information may include an additional ID. The additional ID may be different from the destination ID for terminal A's SL transmission. Terminal C, which has the same ID as the additional ID, can transmit signals/channels in the COT shared by Terminal A. If the source ID for terminal C's SL transmission is the same as the additional ID indicated by terminal A, terminal C can perform the SL transmission in the COT shared by terminal A. Terminal C may be the same as or different from terminal B. “If the transmission ID for the SL transmission of terminal C is the same as the additional ID indicated by terminal A, and the destination ID for the SL transmission of terminal C is the same as the source ID indicated by terminal A”, terminal C Can transmit signals/channels in the COT shared by terminal A.

COT configuration information may include a source ID and/or destination ID associated with terminal A's transmission. The source ID may be an ID associated with the terminal transmitting the signal/channel. The destination ID may be an ID associated with the terminal receiving the signal/channel. When terminal A transmits a signal/channel to terminal B, the source ID may be terminal A, and the destination ID may be terminal B.

COT setting information (eg, COT sharing information) transmitted by terminal A may include location information of terminal A. For example, the COT setting information may include information on the communication distance requirements of terminal A. Terminal A can transmit coverage information of terminal A. Coverage information of terminal A may be included in COT configuration information. Terminal B may receive at least one of location information of terminal A, communication distance requirement information, or coverage information from terminal A. Terminal B can determine whether terminal B is within the coverage of terminal A based on the location of terminal B and the coverage of terminal A.

If terminal B is located within the coverage of terminal A, terminal B can transmit signals/channels in the COT shared by terminal A. In other words, the COT initiated by terminal A can be shared with terminal B. If terminal B is not located within the coverage of terminal A, terminal B cannot transmit signals/channels in the COT shared by terminal A. In other words, the COT initiated by terminal A may not be shared with terminal B.

The COT initiated by terminal A can be shared with terminal B, and terminal B can perform communication using the COT. Terminal B can transmit a signal/channel to terminal A within the COT shared by terminal A. In other words, the destination of the signal/channel transmitted by terminal B within the COT shared by terminal A may include terminal A. Terminal B cannot transmit signals/channels within the COT shared by Terminal A to a terminal other than Terminal A. In other words, within the COT shared by terminal A, signal/channel transmission to a destination other than the destination including terminal A may not be performed.

The destination ID of terminal B's transmission within the COT shared by terminal A may include the ID of terminal A. Within the COT shared by terminal A, the group corresponding to the destination ID of terminal B's groupcast SL transmission (or multicast SL transmission) may include terminal A.

Terminal A may transmit COT configuration information (e.g., COT sharing information) using SCI. Terminal A can transmit a level 1 SCI including COT configuration information. COT configuration information included in the first-stage SCI may include time domain information and/or frequency domain information of the COT. The time domain information of the COT may indicate the section from the transmission time of the first stage SCI to the end time of the COT. Alternatively, the time domain information of the COT may indicate the interval from the transmission time of the first stage SCI to the start time of the available COT. COT's frequency domain information may indicate the COT's frequency resources. COT setting information included in the first-stage SCI may include priority class information.

Terminal B can receive a SCI (e.g., level 1 SCI) from terminal A and check COT setting information (e.g., COT sharing information) included in the SCI. Terminal B can check the time domain information and/or frequency domain information of the COT included in the COT configuration information. Terminal B can check the priority class information included in the COT setting information. When a level 1 SCI including COT setting information is received, terminal B may determine that the COT associated with the COT setting information is available. Terminal B can transmit a signal/channel in the COT associated with the COT configuration information.

Terminal A may transmit a second-level SCI including COT configuration information (e.g., COT sharing information). COT configuration information may be included in at least one of a first-level SCI or a second-level SCI. When COT setting information is transmitted through a first-level SCI and a second-level SCI, part of the COT setting information may be included in the first-level SCI, and the remainder of the COT setting information may be included in the second-level SCI.

COT configuration information included in the first-stage SCI may include time domain information and/or frequency domain information of the COT. The time domain information of the COT may indicate the section from the transmission time of the first stage SCI to the end time of the COT. Alternatively, the time domain information of the COT may indicate the interval from the transmission time of the first stage SCI to the start time of the available COT. COT's frequency domain information may indicate the COT's frequency resources. COT setting information included in the first-stage SCI may include priority class information.

COT setting information included in the second-level SCI may include time domain information and/or frequency domain information of the COT. The time domain information of the COT may indicate the section from the transmission time of the second-stage SCI to the end time of the COT. Alternatively, the time domain information of the COT may indicate the interval from the transmission time of the second-stage SCI to the start time of the available COT. COT's frequency domain information may indicate the COT's frequency resources. COT setting information included in the second-level SCI may include priority class information.

COT setting information included in the second-stage SCI may include sharing target information. The sharing target information may include the ID of a terminal that can use the COT (eg, shared COT). The shared target information may include location information of a terminal that can use the COT (eg, shared COT).

Terminal B can receive the second-level SCI and check the COT setting information included in the second-level SCI. Terminal B can check the time domain information and/or frequency domain information of the COT included in the COT configuration information. Terminal B can check the priority class information included in the COT setting information. When a second-level SCI including COT setting information (e.g., COT sharing information) is received from terminal A, terminal B may determine that the COT associated with the COT setting information is available. The COT associated with the COT configuration information may be a COT initiated by terminal A.

Terminal B can transmit a signal/channel in the COT associated with the COT configuration information. Terminal B can receive sharing target information from terminal A and check whether terminal B is included in the sharing target indicated by the sharing target information. If terminal B is included in the sharing target indicated by the sharing target information, terminal B can transmit a signal/channel in the shared COT. If terminal B is not included in the sharing target indicated by the sharing target information, terminal B cannot transmit signals/channels in the shared COT.

Terminal A may transmit SCI format 2-A including COT configuration information (e.g., COT sharing information). In this case, the range of terminals sharing the COT initiated by terminal A may vary depending on the cast type indicator included in SCI format 2-A. Terminal B can receive SCI format 2-A from terminal A and can receive COT configuration information included in SCI format 2-A. In this case, terminal B can check whether the COT associated with the COT setting information is available based on the cast type indicator included in SCI format 2-A.

If the cast type indicator indicates unicast, the COT initiated by terminal A can be shared with the terminal performing unicast SL transmission. "If terminal A performs unicast SL transmission for terminal B based on SCI format 2-A, and the SCI format 2-A includes COT configuration information, terminal B transmits the COT associated with the COT configuration information. A signal/channel can be transmitted in (e.g., a COT initiated by terminal A). Terminal B can check whether the COT is available using the COT setting information and destination ID included in SCI format 2-A. .If the COT initiated by terminal A is available, terminal B can transmit a signal/channel in the COT.

When the destination of terminal B's SL transmission is terminal A, terminal B can perform the SL transmission using the COT initiated by terminal A. If the destination ID for terminal B's unicast SL transmission is the ID of terminal A, terminal B can perform the unicast SL transmission in the COT initiated by terminal A. If the destination ID included in the SCI for terminal B's unicast SL transmission is set to the ID of terminal A, terminal B can perform the unicast SL transmission in the COT initiated by terminal A. In other words, UE B's unicast SL transmission can be performed in the COT shared by UE A.

If the destination for terminal B's unicast SL transmission is not terminal A, terminal B may not perform the unicast SL transmission in the COT initiated by terminal A. In other words, UE B's unicast SL transmission may not be performed in the COT shared by UE A. In this case, terminal B can acquire a new COT for unicast SL transmission and perform the unicast SL transmission in the new COT.

If the destination ID for terminal B's groupcast SL transmission is the ID of the group to which terminal A belongs, terminal B can perform the groupcast SL transmission in the COT initiated by terminal A. If the destination ID included in the SCI for terminal B's groupcast SL transmission is set to the ID of the group to which terminal A belongs, terminal B can perform the groupcast SL transmission in the COT initiated by terminal A. In other words, UE B's groupcast SL transmission can be performed in the COT shared by UE A.

If the destination ID for terminal B's groupcast SL transmission is not the ID of the group to which terminal A belongs, terminal B may not perform the groupcast SL transmission in the COT initiated by terminal A. In other words, UE B's groupcast SL transmission may not be performed in the COT shared by UE A. In this case, terminal B can acquire a new COT for groupcast SL transmission and perform the groupcast SL transmission in the new COT.

If the destination ID for terminal B's groupcast SL transmission is the same as the destination ID for terminal A's SL transmission, terminal B can perform the groupcast SL transmission in the COT initiated by terminal A. If the destination ID included in the SCI for terminal B's groupcast SL transmission is the same as the destination ID for terminal A's SL transmission, terminal B can perform the groupcast SL transmission in the COT initiated by terminal A. there is. If the destination ID for terminal B's groupcast SL transmission is different from the destination ID for terminal A's SL transmission, terminal B may not perform the groupcast SL transmission in the COT initiated by terminal A. In this case, terminal B can acquire a new COT for groupcast SL transmission and perform the groupcast SL transmission in the new COT.

Terminal B can perform broadcast SL transmission in the COT initiated by Terminal A. Alternatively, terminal B may not be able to perform broadcast SL transmission in the COT initiated by terminal A. In this case, terminal B can acquire a new COT for broadcast SL transmission and perform the broadcast SL transmission in the new COT.

If the cast type indicator indicates groupcast, the sharing target of the COT initiated by terminal A may be the terminal(s) receiving the groupcast SL transmission. "Terminal A performs groupcast SL transmission for a group including terminal B and terminal C using SCI (e.g., SCI format 2-A), and uses the SCI (e.g., SCI format 2-A) ) includes COT configuration information, the terminal B and/or the terminal C may perform SL transmission in the COT initiated by the terminal A. Terminal B and/terminal C can check whether the COT is available based on the COT setting information and destination ID included in the SCI (eg, SCI format 2-A). If the COT initiated by terminal A is available, terminal B and/or terminal C can perform SL transmission using the COT.

"If the COT initiated by terminal A is shared, and the destination for the SL transmission of terminal B and/or terminal C is terminal A, the terminal B and/or terminal C The SL transmission may be performed. “If the SL transmission of terminal B and/or terminal C is a unicast SL transmission, and the destination ID for the unicast SL transmission is the ID of terminal A,” the terminal B and/ Alternatively, the terminal C may perform the SL transmission in the COT shared by the terminal A. The destination ID included in the SCI for the unicast SL transmission of terminal B and/or terminal C is set to the ID of terminal A. In this case, the terminal B and/or the terminal C may perform the unicast SL transmission in the COT shared by the terminal A. The destination for the unicast SL transmission of terminal B and/or terminal C is terminal A. If not, the terminal B and/or the terminal C may not perform the unicast SL transmission in the COT shared by the terminal A. In this case, the terminal B and/or the terminal C may transmit the unicast SL. A new COT can be obtained for , and the unicast SL transmission can be performed in the new COT.

If the destination ID for groupcast SL transmission of terminal B and/or terminal C is the ID of the group to which terminal A belongs, the terminal B and/or terminal C transmit the groupcast SL in the COT shared by terminal A. Transmission can be performed. If the destination ID included in the SCI for groupcast SL transmission of terminal B and/or terminal C is the ID of the group to which terminal A belongs, the terminal B and/or terminal C are connected to the COT shared by terminal A. The group cast SL transmission can be performed. If the destination for the groupcast SL transmission of terminal B and/or terminal C is not a group to which terminal A belongs, terminal B and/or terminal C transmit the groupcast SL in the COT shared by terminal A. cannot be performed In this case, terminal B and/or terminal C can acquire a new COT for groupcast SL transmission and perform the groupcast SL transmission in the new COT.

Terminal B and/or Terminal C may perform broadcast SL transmission in the COT initiated by Terminal A. Alternatively, terminal B and/or terminal C may not be able to perform broadcast SL transmission in the COT initiated by terminal A. In this case, terminal B and/or terminal C may acquire a new COT for broadcast SL transmission and perform the broadcast SL transmission in the new COT.

When the cast type indicator indicates broadcast, the sharing target of the COT initiated by terminal A may be the terminal(s) receiving the broadcast SL transmission. “If terminal A performs broadcast SL transmission using SCI (e.g., SCI format 2-A), and the SCI (e.g., SCI format 2-A) includes COT configuration information”, The terminal(s) receiving the SCI (eg, SCI format 2-A) may perform SL transmission in the COT initiated by terminal A. The terminal(s) may perform SL transmission using the COT shared by terminal A based on the COT configuration information included in the SCI (eg, SCI format 2-A).

If the destination for SL transmission is terminal A, the terminal can perform the SL transmission in the COT shared by terminal A. If the destination ID for the terminal's unicast SL transmission is the ID of terminal A, the terminal can perform unicast SL transmission in the COT shared by terminal A. If the destination ID included in the SCI for unicast SL transmission of the terminal is set to the ID of terminal A, the terminal can perform unicast SL transmission in the COT shared by terminal A. If terminal A is not the destination of the terminal's unicast SL transmission, the terminal may not perform the SL transmission in the COT shared by terminal A. In this case, the terminal can acquire a new COT for unicast SL transmission and perform the unicast SL transmission in the new COT.

If the destination ID for terminal B's groupcast SL transmission is the ID of the group to which terminal A belongs, terminal B can perform the groupcast SL transmission in the COT shared by terminal A. If the destination ID included in the SCI for terminal B's groupcast SL transmission is the ID of the group to which terminal A belongs, terminal B can perform the groupcast SL transmission in the COT shared by terminal A. If the destination for terminal B's groupcast SL transmission is not the group to which terminal A belongs, terminal B may not perform the groupcast SL transmission in the COT shared by terminal A. In this case, terminal B can acquire a new COT for groupcast SL transmission and perform the groupcast SL transmission in the new COT.

The terminal can perform broadcast SL transmission in the COT shared by terminal A. Alternatively, the terminal may not be able to perform broadcast SL transmission in the COT shared by terminal A. In this case, the terminal can acquire a new COT for broadcast SL transmission and perform the broadcast SL transmission in the new COT.

Figure 10 is a flowchart showing a second embodiment of a communication method in an unlicensed band.

Referring to FIG. 10, terminal A may transmit signal/channel and COT configuration information (eg, COT sharing information) to terminal B. Terminal B can receive signal/channel and COT setting information from terminal A (S1010). Signal/channel and COT configuration information can be transmitted independently. Alternatively, COT configuration information may be included in the signal/channel. COT configuration information may be transmitted to terminal B through signaling. Signaling may be at least one of system information (SI) signaling, RRC signaling, MAC CE signaling, or PHY signaling.

Terminal B can compare the source ID for the signal/channel received from terminal A and the destination ID for the signal/channel that terminal B wants to transmit (S1020). The signal/channel transmitted by terminal A may be referred to as signal A, and the signal/channel desired to be transmitted by terminal B may be referred to as signal B. Terminal B can determine the COT where signal B will be transmitted based on the result of S1020.

If the source ID for signal A is the same as the destination ID for signal B, terminal B determines whether the time and/or frequency resources for transmission of signal B belong to the time and/or frequency resources of the COT initiated by terminal A. You can check (S1030). Terminal B can determine the COT where signal B will be transmitted based on the result of S1030. If the time and/or frequency resources for transmission of signal B belong to the time and/or frequency resources of the COT initiated by terminal A, terminal B may transmit the signal B in the COT initiated by terminal A (S1040 ). In other words, terminal B can share the COT initiated by terminal A.

If the source ID for signal A is different from the destination ID for signal B in S1020, terminal B can obtain a new COT for transmission of signal B (S1050). Terminal B can transmit signal B in the new COT (S1060). In S1030, if the time and/or frequency resources for transmission of signal B do not belong to the time and/or frequency resources of the COT initiated by terminal A, terminal B may acquire a new COT for transmission of signal B ( S1050). Terminal B can transmit signal B in the new COT (S1060).

Figure 11 is a flowchart showing a third embodiment of a communication method in an unlicensed band.

Referring to FIG. 11, terminal A may transmit a signal/channel (e.g., signal A) and COT setting information (e.g., COT sharing information) to terminal B. Terminal B can receive signal A and COT configuration information from terminal A (S1110). Signal A and COT configuration information can be transmitted independently. Alternatively, COT configuration information may be included in signal A. COT configuration information may be transmitted to terminal B through signaling.

Terminal B may compare the destination ID for signal A received from terminal A with the destination ID for the signal/channel (eg, signal B) that terminal B wants to transmit (S1120). Terminal B can determine the COT where signal B will be transmitted based on the result of S1020.

If the destination ID for signal A is the same as the destination ID for signal B, terminal B determines whether the time and/or frequency resources for transmission of signal B belong to the time and/or frequency resources of the COT initiated by terminal A. You can check (S1130). Terminal B can determine the COT where signal B will be transmitted based on the result of S1130. If the time and/or frequency resources for transmission of signal B belong to the time and/or frequency resources of the COT initiated by terminal A, terminal B may transmit the signal B in the COT initiated by terminal A (S1140 ). In other words, terminal B can share the COT initiated by terminal A.

If the destination ID for signal A is different from the destination ID for signal B in S1120, terminal B can obtain a new COT for transmission of signal B (S1150). Terminal B can transmit signal B in the new COT (S1160). In S1130, if the time and/or frequency resources for transmission of signal B do not belong to the time and/or frequency resources of the COT initiated by terminal A, terminal B may acquire a new COT for transmission of signal B ( S1150). Terminal B can transmit signal B in the new COT (S1160).

Figure 12 is a flowchart showing a fourth embodiment of a communication method in an unlicensed band.

Referring to FIG. 12, terminal A may transmit at least one of terminal A's location information, communication distance requirement information, coverage information, or COT setting information to terminal B. Terminal B may receive at least one of location information of terminal A, information on communication distance requirements, coverage information, or COT setting information from terminal A (S1210). Terminal B can check the coverage of terminal A based on information received from terminal A (S1220).

Terminal B can check whether terminal B is within the coverage of terminal A based on the location of terminal B (S1230). When Terminal B is within the coverage of Terminal A, Terminal B determines that the time and/or frequency resources for transmission of the signal/channel (e.g., signal B) that Terminal B wants to transmit are in the COT initiated by Terminal A. It is possible to check whether it belongs to the time and/or frequency resources (S1240). Terminal B can determine the COT where signal B will be transmitted based on the result of S1240. If the time and/or frequency resources for transmission of signal B belong to the time and/or frequency resources of the COT initiated by terminal A, terminal B may transmit the signal B in the COT initiated by terminal A (S1250 ). In other words, terminal B can share the COT initiated by terminal A.

If terminal B does not exist within the coverage of terminal A in S1230, terminal B can obtain a new COT for transmission of signal B (S1260). Terminal B can transmit signal B in the new COT (S1270). In S1240, if the time and/or frequency resources for transmission of signal B do not belong to the time and/or frequency resources of the COT initiated by terminal A, terminal B may acquire a new COT for transmission of signal B ( S1260). Terminal B can transmit signal B in the new COT (S1270).

Meanwhile, terminal A can set a COT and share the COT with terminal B. In other words, terminal A can transmit COT sharing information (eg, COT configuration information) to terminal B. Terminal B can receive COT sharing information from terminal A and confirm the COT shared by terminal A based on the COT sharing information. For example, terminal B can check the time and/or frequency resources of the COT shared by terminal A. Terminal B can perform S-SSB (sidelink-synchronization signal block) transmission in the shared COT.

S-SSB transmission can be performed according to a preset cycle. If the S-SSB transmission time according to the S-SSB transmission cycle belongs to the COT shared by UE A, UE B can perform S-SSB transmission in the shared COT. If the S-SSB transmission time according to the S-SSB transmission cycle does not belong to the COT shared by UE A, UE B may not perform S-SSB transmission in the shared COT. In this case, terminal B can perform a separate channel access procedure for S-SSB transmission, and can perform S-SSB transmission if the channel access procedure is successful.

S-SSB transmission may be performed on preset resources (eg, preset frequency resources). If the frequency resource of S-SSB belongs to the COT shared by UE A, UE B can perform S-SSB transmission in the shared COT. If the frequency resource of S-SSB does not belong to the COT shared by UE A, UE B may not perform S-SSB transmission in the shared COT. In this case, terminal B can perform a separate channel access procedure for S-SSB transmission, and can perform S-SSB transmission if the channel access procedure is successful.

Terminal A may transmit PSCCH and/or PSSCH (eg, control information and/or data) to terminal B. Terminal B may receive PSCCH and/or PSSCH from terminal A, and may transmit HARQ feedback (eg, HARQ-ACK response) for the PSCCH and/or PSSCH to terminal A. HARQ feedback may be transmitted on PSFCH.

Terminal A can initiate a COT and share the COT with Terminal B. For example, terminal A may transmit COT sharing information (e.g., COT configuration information) to terminal B. Terminal B can receive COT sharing information from terminal A and confirm the shared COT based on the COT sharing information. Terminal B may perform PSFCH transmission (e.g., transmission of HARQ feedback) in the COT shared by UE A.

“If the COT initiated by UE A is shared with UE B, and the PSFCH of UE B includes at least one HARQ feedback for the SL transmission (e.g., PSCCH transmission and/or PSSCH transmission) of UE A ", The terminal B can perform PSFCH transmission in the COT shared by the terminal A. PSFCH transmission may be transmission of HARQ feedback for UE A. Alternatively, PSFCH transmission may be transmission of HARQ feedback for terminal A and HARQ feedback for other terminals. If the time and/or frequency resources for PSFCH transmission of terminal B belong to the time and/or frequency resources of the COT shared by terminal A, the terminal B may perform PSFCH transmission in the COT shared by terminal A. You can.

“If the COT initiated by terminal A is shared with terminal B, and the PSFCH of terminal B does not include HARQ feedback for the SL transmission (e.g., PSCCH transmission and/or PSSCH transmission) of terminal A”, The terminal B may not perform PSFCH transmission in the COT shared by the terminal A. In this case, terminal B can perform a separate channel access procedure for PSFCH transmission, and can perform the PSFCH transmission if the channel access procedure is successful.

Terminal A may transmit PSCCH and/or PSSCH to terminal B. Terminal A can transmit COT sharing information to terminal B. Terminal B can receive PSCCH and/or PSSCH from terminal A. Terminal B can receive COT sharing information from terminal A.

Terminal B can confirm the COT shared by terminal A based on the COT sharing information received from terminal A. In other words, the COT initiated by terminal A can be shared with terminal B. Terminal B may perform PSCCH transmission and/or PSSCH transmission in the COT shared by UE A. When the destination of terminal B's SL transmission is terminal A, terminal B may perform the SL transmission (e.g., PSCCH transmission and/or PSSCH transmission) in the COT shared by terminal A. If the destination of terminal B's SL transmission includes terminal A, terminal B may perform the SL transmission (e.g., PSCCH transmission and/or PSSCH transmission) in the COT shared by terminal A. Time and/or frequency resources for SL transmission of terminal B are indicated by COT sharing information of terminal A (e.g., time and/or frequency resources of COT shared by terminal A) When belonging to , the terminal B may perform SL transmission (e.g., PSCCH transmission and/or PSSCH transmission) in the COT shared by the terminal A.

If the destination of terminal B's SL transmission does not include terminal A, terminal B may not perform the SL transmission (e.g., PSCCH transmission and/or PSSCH transmission) in the COT shared by terminal A. there is. In this case, terminal B may perform a separate channel access procedure for SL transmission, and if the channel access procedure is successful, the SL transmission (e.g., PSCCH transmission and/or PSSCH transmission) may be performed. .

Methods according to the present disclosure may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. Computer-readable media may include program instructions, data files, data structures, etc., singly or in combination. Program instructions recorded on a computer-readable medium may be specially designed and configured for the present disclosure or may be known and usable by those skilled in the art of computer software.

Examples of computer-readable media include hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, etc. Examples of program instructions include machine language code, such as that produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc. The above-described hardware device may be configured to operate with at least one software module to perform the operations of the present disclosure, and vice versa.

Although the description has been made with reference to the above embodiments, those skilled in the art will understand that various modifications and changes can be made to the present disclosure without departing from the spirit and scope of the present disclosure as set forth in the following patent claims. You will be able to.

Claims (18)

As a method of the first terminal,
Receiving shared information of COT (channel occupancy time) initiated by the second terminal from the second terminal;
determining whether sidelink (SL) transmission of the first terminal can be performed in the COT based on the shared information; and
If the SL transmission can be performed in the COT, performing the SL transmission in the COT shared by the second terminal,
Method of the first terminal. In claim 1,
The shared information includes at least one of a source identifier, destination ID, channel access priority class (CAPC), remaining COT duration, or frequency domain information of the COT,
Method of the first terminal. In claim 1,
The COT is initiated by a type 1 listen before talk (LBT) operation of the second terminal, and the SL transmission of the first terminal in the COT is performed based on a type 2 LBT operation, and the type 1 LBT operation is is performed in a variable time interval, and the type 2 LBT operation is performed in a fixed time interval,
Method of the first terminal. In claim 1,
"If the SL transmission is a unicast SL transmission, the source of the unicast SL transmission is the same as the destination of the second terminal's transmission, and the destination of the unicast SL transmission is the same as the source of the second terminal's transmission ", the unicast SL transmission is performed in the COT shared by the second terminal,
Method of the first terminal. In claim 1,
“If the SL transmission is a groupcast SL transmission and the destination of the groupcast SL transmission is the same as the destination of the second terminal’s transmission,” the groupcast SL transmission is performed in the COT shared by the second terminal. felled,
Method of the first terminal. In claim 1,
“If the SL transmission is a broadcast SL transmission and the destination of the broadcast SL transmission is the same as the destination of the second terminal’s transmission,” the broadcast SL transmission is performed in the COT shared by the second terminal. felled,
Method of the first terminal. In claim 1,
The step of performing the SL transmission is,
Including transmitting a sidelink-synchronization signal block (S-SSB) in the COT,
Method of the first terminal. In claim 1,
“If the SL transmission is a physical sidelink feedback channel (PSFCH) transmission, and the PSFCH transmission includes a hybrid automatic repeat request (HARQ) feedback transmission for the second terminal,” the PSFCH transmission is performed by the second terminal. performed on the shared COT,
Method of the first terminal. In claim 1,
If the resource for the SL transmission belongs to the resources of the COT, the SL transmission is performed in the COT,
Method of the first terminal. As a first terminal,
Contains at least one processor,
The at least one processor is the first terminal,
Receive shared information of COT (channel occupancy time) initiated by the second terminal from the second terminal;
Determine whether sidelink (SL) transmission of the first terminal can be performed in the COT based on the shared information; and
If the SL transmission can be performed in the COT, causing the SL transmission to be performed in the COT shared by the second terminal,
1st terminal. In claim 10,
The shared information includes at least one of a source identifier, destination ID, channel access priority class (CAPC), remaining COT duration, or frequency domain information of the COT,
1st terminal. In claim 10,
The COT is initiated by a type 1 listen before talk (LBT) operation of the second terminal, and the SL transmission of the first terminal in the COT is performed based on a type 2 LBT operation, and the type 1 LBT operation is is performed in a variable time interval, and the type 2 LBT operation is performed in a fixed time interval,
1st terminal. In claim 10,
"If the SL transmission is a unicast SL transmission, the source of the unicast SL transmission is the same as the destination of the second terminal's transmission, and the destination of the unicast SL transmission is the same as the source of the second terminal's transmission ", the unicast SL transmission is performed in the COT shared by the second terminal,
1st terminal. In claim 10,
“If the SL transmission is a groupcast SL transmission and the destination of the groupcast SL transmission is the same as the destination of the second terminal’s transmission,” the groupcast SL transmission is performed in the COT shared by the second terminal. felled,
1st terminal. In claim 10,
“If the SL transmission is a broadcast SL transmission and the destination of the broadcast SL transmission is the same as the destination of the second terminal’s transmission,” the broadcast SL transmission is performed in the COT shared by the second terminal. felled,
1st terminal. In claim 10,
When performing the SL transmission, the at least one processor is configured to:
causing the COT to transmit a sidelink-synchronization signal block (S-SSB),
1st terminal. In claim 10,
“If the SL transmission is a physical sidelink feedback channel (PSFCH) transmission, and the PSFCH transmission includes a hybrid automatic repeat request (HARQ) feedback transmission for the second terminal,” the PSFCH transmission is performed by the second terminal. performed on the shared COT,
1st terminal. In claim 10,
If the resource for the SL transmission belongs to the resources of the COT, the SL transmission is performed in the COT,
1st terminal.

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