Method and apparatus for performing multiple consecutive slot transmissions

Abstract

Provided are a method by which a first device performs wireless communication and an apparatus supporting same. The method may comprise the steps of: transmitting first data to a second device on the basis of a first slot from among slots for multiple consecutive slot transmissions; receiving a positive acknowledgement (ACK) for the first data from the second device; and on the basis of the positive ACK for the first data, flushing a hybrid automatic repeat request (HARQ) buffer of a sidelink process related to the first data, except that at least one slot for the first data remains from among the slots for the multiple consecutive slot transmissions.

Description

Method and device for performing multiple consecutive slot transmissions

[0001] The present disclosure relates to a wireless communication system.

[0002] 5G NR, the successor to LTE (long-term evolution), is a new clean-slate mobile communications system characterized by high performance, low latency, and high availability. 5G NR can utilize all available spectrum resources, from low-frequency bands below 1 GHz, mid-frequency bands between 1 GHz and 10 GHz, and high-frequency (millimeter wave) bands above 24 GHz.

[0003] The 6G (wireless communication) system aims to achieve (i) very high data rates per device, (ii) a very large number of connected devices, (iii) global connectivity, (iv) very low latency, (v) low energy consumption for battery-free Internet of Things (IoT) devices, (vi) ultra-reliable connectivity, and (vii) connected intelligence with machine learning capabilities. The vision of the 6G system can be divided into four aspects: intelligent connectivity, deep connectivity, holographic connectivity, and ubiquitous connectivity, and the 6G system can satisfy the requirements as shown in Table 1 below. For example, Table 1 can represent an example of the requirements of a 6G system.

[0004] Per device peak data rate 1 Tbps E2E latency 1 ms Maximum spectral efficiency 100 bps / Hz Mobility support Up to 1000 km / hr Satellite integration Fully AI Fully autonomous vehicle Fully XR Fully haptic communication Fully

[0005] In one embodiment, a method for performing wireless communication by a first device is provided. The method may include: transmitting first data to a second device based on a first slot among slots for multiple consecutive slot transmissions; receiving a positive acknowledgment (ACK) for the first data from the second device; and flushing a hybrid automatic repeat request (HARQ) buffer of a sidelink process associated with the first data, except that at least one slot for the first data remains among the slots for the multiple consecutive slot transmissions, based on the positive ACK for the first data.

[0006] In one embodiment, a first device configured to perform wireless communication is provided. The first device may include at least one transceiver; at least one processor; and at least one memory coupled to the at least one processor and storing instructions. For example, the instructions, when executed by the at least one processor, may cause the first device to: transmit first data to a second device based on a first slot among slots for multiple consecutive slot transmissions; receive a positive acknowledgment (ACK) for the first data from the second device; and flush a hybrid automatic repeat request (HARQ) buffer of a sidelink process associated with the first data based on the positive ACK for the first data, except that at least one slot for the first data remains among the slots for the multiple consecutive slot transmissions.

[0007] In one embodiment, a processing device configured to control a first device is provided. The processing device comprises at least one processor; and at least one memory coupled to the at least one processor and storing instructions, wherein the instructions, when executed by the at least one processor, cause the first device to: transmit first data to a second device based on a first slot among slots for multiple consecutive slot transmission; receive a positive acknowledgment (ACK) for the first data from the second device; and, based on the positive ACK for the first data, flush a hybrid automatic repeat request (HARQ) buffer of a sidelink process associated with the first data except that at least one slot for the first data remains among the slots for the multiple consecutive slot transmission.

[0008] In one embodiment, a non-transitory computer-readable storage medium having instructions recorded thereon is provided. The instructions, when executed, cause a first device to: transmit first data to a second device based on a first slot among slots for multiple consecutive slot transmissions; receive a positive acknowledgment (ACK) for the first data from the second device; and, based on the positive ACK for the first data, flush a hybrid automatic repeat request (HARQ) buffer of a sidelink process associated with the first data except that at least one slot for the first data remains among the slots for the multiple consecutive slot transmissions.

[0009] FIG. 1 illustrates a communication structure that can be provided in a 6G system according to one embodiment of the present disclosure.

[0010] FIG. 2 illustrates an electromagnetic spectrum according to one embodiment of the present disclosure.

[0011] FIG. 3 illustrates an example of a typical scenario of an NTN based on a transparent payload, according to one embodiment of the present disclosure.

[0012] FIG. 4 illustrates an example of a typical scenario of an NTN based on a regenerative payload, according to one embodiment of the present disclosure.

[0013] FIG. 5 illustrates an example of a sensing operation according to one embodiment of the present disclosure.

[0014] FIG. 6 illustrates a slot structure of a frame according to one embodiment of the present disclosure.

[0015] FIG. 7 illustrates an example of a BWP according to one embodiment of the present disclosure.

[0016] FIG. 8 illustrates a procedure for a terminal to perform V2X or SL communication according to a resource allocation mode, according to one embodiment of the present disclosure.

[0017] FIG. 9 illustrates an example of a wireless communication system supporting an unlicensed band according to one embodiment of the present disclosure.

[0018] FIG. 10 illustrates a method for occupying resources within an unlicensed band, according to one embodiment of the present disclosure.

[0019] FIG. 11 illustrates a case where multiple LBT-SBs are included within an unlicensed band, according to one embodiment of the present disclosure.

[0020] FIG. 12 illustrates a CAP operation for downlink signal transmission through an unlicensed band of a base station according to an embodiment of the present disclosure.

[0021] FIG. 13 illustrates a type 1 CAP operation of a terminal for uplink signal transmission according to an embodiment of the present disclosure.

[0022] FIG. 14 illustrates a channel connection procedure according to one embodiment of the present disclosure.

[0023] FIG. 15 illustrates a retransmission operation / HARQ buffer management operation / sidelink grant management operation based on reception of HARQ feedback by a terminal during MCSt-based SL TB transmission according to an embodiment of the present disclosure.

[0024] FIG. 16 illustrates an operation of managing HARQ buffers and grants related to SL TB when receiving HARQ feedback for MCSt-based SL TB transmission according to one embodiment of the present disclosure.

[0025] FIG. 17 illustrates an operation of managing HARQ buffers and grants related to SL TB when receiving HARQ feedback for MCSt-based SL TB transmission according to one embodiment of the present disclosure.

[0026] FIG. 18 illustrates a retransmission operation / HARQ buffer management operation / sidelink grant management operation based on reception of HARQ feedback by a terminal during MCSt-based SL TB transmission according to an embodiment of the present disclosure.

[0027] FIG. 19 illustrates a retransmission operation / HARQ buffer management operation / sidelink grant management operation based on reception of HARQ feedback by a terminal during MCSt-based SL TB transmission according to an embodiment of the present disclosure.

[0028] FIG. 20 illustrates a method for a first device to perform wireless communication according to one embodiment of the present disclosure.

[0029] FIG. 21 illustrates a method for a second device to perform wireless communication according to one embodiment of the present disclosure.

[0030] Fig. 22 shows a communication system (1) according to one embodiment of the present disclosure.

[0031] FIG. 23 illustrates a wireless device according to one embodiment of the present disclosure.

[0032] FIG. 24 illustrates a signal processing circuit for a transmission signal according to one embodiment of the present disclosure.

[0033] FIG. 25 illustrates a wireless device according to one embodiment of the present disclosure.

[0034] FIG. 26 illustrates a mobile device according to one embodiment of the present disclosure.

[0035] FIG. 27 illustrates a vehicle or autonomous vehicle according to one embodiment of the present disclosure.

[0036] As used herein, "A or B" can mean "only A," "only B," or "both A and B." In other words, as used herein, "A or B" can be interpreted as "A and / or B." For example, as used herein, "A, B or C" can mean "only A," "only B," "only C," or "any combination of A, B and C."

[0037] As used herein, a slash ( / ) or a comma can mean "and / or." For example, "A / B" can mean "A and / or B." Accordingly, "A / B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

[0038] In this specification, "at least one of A and B" may mean "only A", "only B" or "both A and B". Additionally, in this specification, the expressions "at least one of A or B" or "at least one of A and / or B" may be interpreted identically to "at least one of A and B".

[0039] Additionally, in this specification, “at least one of A, B and C” can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C.”

[0040] Additionally, parentheses used herein may mean "for example." Specifically, when indicated as "control information (PDCCH)", "PDCCH" may be proposed as an example of "control information." In other words, "control information" in this specification is not limited to "PDCCH," and "PDCCH" may be proposed as an example of "control information." Furthermore, even when indicated as "control information (i.e., PDCCH)", "PDCCH" may be proposed as an example of "control information."

[0041] In the following explanation, ‘when, if, in case of’ can be replaced with ‘based on’.

[0042] Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously.

[0043] In this specification, higher layer parameters may be parameters that are set for the terminal, preset, or predefined. For example, a base station or network may transmit higher layer parameters to the terminal. For example, higher layer parameters may be transmitted via radio resource control (RRC) signaling or medium access control (MAC) signaling.

[0044] In this specification, "configured or defined" may be interpreted as being configured or preset to a device through predefined signaling (e.g., SIB, MAC, RRC) from a base station or network. In this specification, "configured or defined" may be interpreted as being preset to a device.

[0045] The technology proposed in this specification can be used in various wireless communication systems such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented with wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (global system for mobile communications) / GPRS (general packet radio service) / EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented with wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (evolved UTRA), LTE (long term evolution), and 5G NR.

[0046] The technology proposed in this specification can be implemented with 6G wireless technology and applied to various 6G systems. For example, 6G systems can have key factors such as enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), massive machine-type communication (mMTC), artificial intelligence (AI) integrated communication, tactile internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion, and enhanced data security.

[0047] FIG. 1 illustrates a communication structure that can be provided in a 6G system according to one embodiment of the present disclosure. The embodiment of FIG. 1 can be combined with various embodiments of the present disclosure.

[0048] New network characteristics in 6G may include:

[0049] - Satellite integrated network

[0050] - Connected Intelligence: Unlike previous generations of wireless communication systems, 6G is revolutionary, upgrading the wireless evolution from "connected objects" to "connected intelligence." AI can be applied at every stage of the communication process (or at every signal processing step, as described below).

[0051] - Seamless integration of wireless information and energy transfer

[0052] - Ubiquitous super 3D connectivity: Access to networks and core network functions of drones and very low Earth orbit satellites will create super 3D connectivity in 6G ubiquitous.

[0053] Some general requirements for the new network characteristics of 6G, such as the above, may be as follows:

[0054] - small cell networks

[0055] - Ultra-dense heterogeneous network

[0056] - High-capacity backhaul

[0057] - Radar technology integrated with mobile technology: High-precision localization (or location-based services) through communications is a key feature of 6G wireless communication systems. Therefore, radar systems will be integrated with 6G networks.

[0058] - Softwarization and virtualization

[0059] Below, the core implementation technologies of the 6G system are described.

[0060] - Artificial Intelligence: Incorporating AI into communications can streamline and improve real-time data transmission. AI can use numerous analytics to determine how complex target tasks should be performed. This means AI can increase efficiency and reduce processing delays. Time-consuming tasks such as handovers, network selection, and resource scheduling can be performed instantly using AI. AI can also play a key role in machine-to-machine (M2M), machine-to-human, and human-to-machine communications. Furthermore, AI can facilitate rapid communication in brain-computer interfaces (BCIs). AI-based communication systems can be supported by metamaterials, intelligent structures, intelligent networks, intelligent devices, intelligent cognitive radios, self-sustaining wireless networks, and machine learning.

[0061] - THz communication (terahertz communication): Data rates can be increased by increasing the bandwidth. This can be achieved by utilizing sub-THz communication with a wide bandwidth and applying advanced massive MIMO technology. THz waves, also known as sub-millimeter waves, typically refer to the frequency range between 0.1 THz and 10 THz with corresponding wavelengths ranging from 0.03 mm to 3 mm. The 100 GHz to 300 GHz band (Sub-THz band) is considered a major portion of the THz band for cellular communications. Adding the Sub-THz band to the mmWave band will increase the capacity of 6G cellular communications. Among the defined THz bands, 300 GHz to 3 THz lies in the far infrared (IR) frequency band. While part of the optical band, the 300 GHz to 3 THz band lies at the boundary of the optical band, immediately following the RF band. Therefore, this 300 GHz to 3 THz band exhibits similarities to RF. Figure 2 illustrates the electromagnetic spectrum according to one embodiment of the present disclosure. The embodiment of FIG. 2 can be combined with various embodiments of the present disclosure. Key characteristics of THz communications include (i) widely available bandwidth to support very high data rates, and (ii) high path loss at high frequencies (highly directional antennas are essential). The narrow beamwidth generated by the highly directional antenna reduces interference. The small wavelength of THz signals allows for a much larger number of antenna elements to be integrated into devices and base stations operating in this band. This enables the use of advanced adaptive array technologies to overcome range limitations.

[0062] - Large-scale MIMO technology

[0063] - Hologram beamforming (HBF)

[0064] - Optical wireless technology

[0065] - Free-space optical transmission backhaul network (FSO backhaul network)

[0066] - Quantum communication

[0067] - Cell-free communication

[0068] - Integration of wireless information and power transmission

[0069] - Integration of wireless communication and sensing

[0070] - Integrated access and backhaul network

[0071] - Big data analysis

[0072] - Reconfigurable intelligent surface

[0073] - metaverse

[0074] - Blockchain

[0075] Unmanned aerial vehicles (UAVs): UAVs, or drones, will be a key element in 6G wireless communications. In most cases, high-speed data wireless connectivity can be provided using UAV technology. Base stations (BSs) can be installed on UAVs to provide cellular connectivity. UAVs may offer specific capabilities not found in fixed BS infrastructure, such as easy deployment, robust line-of-sight links, and controlled mobility. During emergencies such as natural disasters, deploying terrestrial communications infrastructure is not economically feasible and sometimes cannot provide services in volatile environments. UAVs can easily handle these situations. UAVs will become a new paradigm in wireless communications. This technology facilitates three fundamental requirements for wireless networks: enhanced mobile broadband (eMBB), URLLC, and mMTC. UAVs can also support various purposes, such as enhancing network connectivity, fire detection, disaster emergency services, security and surveillance, pollution monitoring, parking monitoring, and accident monitoring. Therefore, UAV technology is recognized as one of the most important technologies for 6G communications.

[0076] - Advanced air mobility (AAM): AAM is a higher concept than urban air mobility (UAM), which is an air transportation method available in urban areas, and can refer to a means of transportation that includes movement between regional hubs as well as within urban areas.

[0077] - Autonomous driving (self-driving): V2X (vehicle to everything), a key element in building autonomous driving infrastructure, can be a technology that allows cars to communicate and share with various elements on the road for autonomous driving, such as vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) wireless communication. Fast transmission speeds and low-latency technologies are essential to maximize autonomous driving performance and ensure high safety. Furthermore, in the future, autonomous driving will go beyond simply providing warnings or guidance messages to drivers and may require active intervention in vehicle operation and direct control of the vehicle in dangerous situations. To this end, the amount of information that needs to be transmitted and received may become enormous, so 6G is expected to maximize autonomous driving with faster transmission speeds and lower latency than 5G.

[0078] - Non-terrestrial networks (NTN): NTN may refer to a network or network segment that uses radio frequency (RF) resources mounted on a satellite (or unmanned aerial system (UAS) platform). FIG. 3 illustrates an example of a typical NTN scenario based on a transparent payload according to an embodiment of the present disclosure. FIG. 4 illustrates an example of a typical NTN scenario based on a regenerative payload according to an embodiment of the present disclosure. The embodiments of FIG. 3 or FIG. 4 may be combined with various embodiments of the present disclosure. Referring to FIG. 3, a satellite (or UAS platform) may create a service link with a UE. The satellite (or UAS platform) may be connected to a gateway via a feeder link. The satellite may be connected to a data network via the gateway. A beam footprint may refer to an area where a signal transmitted by a satellite can be received. Referring to Figure 4, a satellite (or UAS platform) can establish a service link with a UE. A satellite (or UAS platform) connected to a UE can be connected to another satellite (or UAS platform) via an inter-satellite link (ISL). The other satellite (or UAS platform) can be connected to a gateway via a feeder link. Based on the playback payload, a satellite can be connected to a data network through another satellite and the gateway. If an ISL does not exist between a satellite and another satellite, a feeder link between the satellite and the gateway may be required. Figures 3 and 4 are merely examples of NTN scenarios, and NTN can be implemented based on various scenarios.For example, a satellite (or UAS platform) may implement a transparent or regenerative (with onboard processing) payload. For example, a satellite (or UAS platform) may generate multiple beams over a designated service area depending on the field of view of the satellite (or UAS platform). For example, the field of view of the satellite (or UAS platform) may vary depending on the onboard antenna diagram and minimum elevation angle. For example, a transparent payload may include radio frequency filtering, frequency conversion, and amplification. Therefore, the waveform signal repeated by the payload may not be altered. For example, a regenerative payload may include radio frequency filtering, frequency conversion and amplification, demodulation / decoding, switching and / or routing, and coding / modulation. For example, a regenerative payload may be substantially equivalent to equipping the satellite (or UAS platform) with all or part of the base station functionality.

[0079] - Integrated Sensing and Communication (ISAC): Wireless sensing is a technology that uses radio frequencies to determine the instantaneous linear velocity, angle, distance (range), etc. of an object, thereby obtaining information about the characteristics of the environment and / or objects within the environment. Because radio frequency sensing does not require a device to connect to the object through a network, it can provide a service for object positioning without a device. The ability to obtain range, velocity, and angle information from radio frequency signals can enable a wide range of new capabilities, such as various object detection, object recognition (e.g., vehicles, humans, animals, UAVs), and high-precision localization, tracking, and activity recognition. Wireless sensing services can provide information to a variety of industries (e.g., drones, smart homes, V2X, factories, railways, public safety, etc.), enabling applications such as intruder detection, assisted vehicle steering and navigation, trajectory tracking, collision avoidance, traffic management, and health and traffic management. In some cases, wireless sensing can utilize non-3GPP type sensors (e.g., radar, cameras) to further support 3GPP-based sensing. For example, the operation of a wireless sensing service, i.e., a sensing operation, may depend on the transmission, reflection, and scattering of wireless sensing signals. Therefore, wireless sensing may provide an opportunity to enhance existing communication systems from a communication network to a wireless communication and sensing network. FIG. 5 illustrates an example of a sensing operation according to an embodiment of the present disclosure. The embodiment of FIG. 5 may be combined with various embodiments of the present disclosure. Specifically, FIG. 5 (a) illustrates an example of sensing using a sensing receiver and a sensing transmitter located at the same location (e.g., monostatic sensing), and FIG. 5 (b) illustrates an example of sensing using a separated sensing receiver and a sensing transmitter (e.g., bistatic sensing).

[0080] The layers of the radio interface protocol between the terminal and the network can be divided into L1 (layer 1), L2 (layer 2), and L3 (layer 3) based on the three lower layers of the Open System Interconnection (OSI) standard model, which is widely known in communication systems. Among these, the physical layer belonging to layer 1 provides an information transfer service using a physical channel, and the RRC (Radio Resource Control) layer located in layer 3 controls radio resources between the terminal and the network. To this end, the RRC layer exchanges RRC messages between the terminal and the base station.

[0081] The physical layer provides information transmission services to higher layers using physical channels. The physical layer is connected to the upper layer, the Medium Access Control (MAC) layer, via a transport channel. Data travels between the MAC layer and the physical layer through the transport channel. Transport channels are classified based on how and with what characteristics data is transmitted over the wireless interface.

[0082] Data travels between different physical layers, i.e., between the physical layers of a transmitter and a receiver, via a physical channel. This physical channel can be modulated using Orthogonal Frequency Division Multiplexing (OFDM) and utilizes time and frequency as radio resources.

[0083] The MAC layer provides services to the upper layer, the radio link control (RLC) layer, through logical channels. The MAC layer provides mapping from multiple logical channels to multiple transport channels. Furthermore, the MAC layer provides logical channel multiplexing, which maps multiple logical channels to a single transport channel. The MAC sublayer provides data transmission services on logical channels.

[0084] The RLC layer performs the concatenation, segmentation, and reassembly of RLC Service Data Units (SDUs). To guarantee the various Quality of Service (QoS) required by radio bearers (RBs), the RLC layer provides three operating modes: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). AM RLC provides error correction through automatic repeat request (ARQ).

[0085] The RRC (Radio Resource Control) layer is defined only in the control plane. The RRC layer is responsible for controlling logical channels, transport channels, and physical channels, related to the configuration, reconfiguration, and release of radio bearers. RB refers to a logical path provided by Layer 1 (physical layer or PHY layer) and Layer 2 (MAC layer, RLC layer, Packet Data Convergence Protocol (PDCP) layer, and Service Data Adaptation Protocol (SDAP) layer) for data transmission between the terminal and the network.

[0086] The functions of the PDCP layer in the user plane include the transmission of user data, header compression, and ciphering. The functions of the PDCP layer in the control plane include the transmission of control plane data and encryption / integrity protection.

[0087] The Service Data Adaptation Protocol (SDAP) layer is defined only in the user plane. It performs mapping between QoS flows and data radio bearers, marking QoS flow identifiers (IDs) within downlink and uplink packets, and more.

[0088] Establishing an RB refers to the process of defining the characteristics of the radio protocol layer and channel to provide a specific service, and setting specific parameters and operating methods for each. RBs can be further divided into two types: the Signaling Radio Bearer (SRB) and the Data Radio Bearer (DRB). The SRB is used as a channel to transmit RRC messages in the control plane, while the DRB is used as a channel to transmit user data in the user plane.

[0089] When an RRC connection is established between the RRC layer of the terminal and the RRC layer of the base station, the terminal is in the RRC_CONNECTED state. Otherwise, it is in the RRC_IDLE state. For NR, the RRC_INACTIVE state is additionally defined, and a terminal in the RRC_INACTIVE state can maintain a connection with the core network while releasing the connection with the base station.

[0090] Downlink transmission channels that transmit data from the network to the terminal include the Broadcast Channel (BCH), which transmits system information, and the downlink Shared Channel (SCH), which transmits user traffic or control messages. Traffic or control messages for downlink multicast or broadcast services may be transmitted through the downlink SCH or a separate downlink Multicast Channel (MCH). Meanwhile, uplink transmission channels that transmit data from the terminal to the network include the Random Access Channel (RACH), which transmits initial control messages, and the uplink Shared Channel (SCH), which transmits user traffic or control messages.

[0091] Logical channels that are located above the transport channel and are mapped to the transport channel include the Broadcast Control Channel (BCCH), Paging Control Channel (PCCH), Common Control Channel (CCCH), Multicast Control Channel (MCCH), and Multicast Traffic Channel (MTCH).

[0092] Radio frames can be used for uplink and downlink transmission. A radio frame has a length of 10 ms and can be defined as two 5 ms half-frames (HF). A half-frame can contain five 1 ms subframes (SF). A subframe can be divided into one or more slots, and the number of slots within a subframe can be determined by the subcarrier spacing (SCS). Each slot can contain 12 or 14 OFDM (A) symbols, depending on the cyclic prefix (CP).

[0093] When normal CP is used, each slot can contain 14 symbols. When extended CP is used, each slot can contain 12 symbols. Here, the symbols can include OFDM symbols (or CP-OFDM symbols), SC-FDMA (Single Carrier - FDMA) symbols (or DFT-s-OFDM (Discrete Fourier Transform-spread-OFDM) symbols).

[0094] Table 2 below shows the number of symbols per slot (N) depending on the SCS setting (u) when normal CP or extended CP is used. slot symb ), number of slots per frame (N frame,u slot ) and the number of slots per subframe (N subframe,u slot ) is an example.

[0095] CP type SCS (15*2 u )N slot symb N frame,u slot N subframe,u slot Normal CP15kHz (u=0)1410130kHz (u=1)1420260kHz (u=2)14404120kHz (u=3)14808240kHz (u=4)1416016Extended CP60kHz (u=2)12404

[0096] FIG. 6 illustrates a slot structure of a frame according to an embodiment of the present disclosure. The embodiment of FIG. 6 can be combined with various embodiments of the present disclosure.

[0097] Referring to FIG. 6, a slot includes a plurality of symbols in the time domain. A carrier includes a plurality of subcarriers in the frequency domain. An RB (Resource Block) may be defined as a plurality (e.g., 12) of consecutive subcarriers in the frequency domain. A BWP (Bandwidth Part) may be defined as a plurality of consecutive (P)RBs ((Physical) Resource Blocks) in the frequency domain, and may correspond to one numerology (e.g., SCS, CP length, etc.). A carrier may include up to N (e.g., 5) BWPs. Data communication may be performed through activated BWPs. Each element may be referred to as a Resource Element (RE) in the resource grid, and one complex symbol may be mapped to it.

[0098] A Bandwidth Part (BWP) can be a contiguous set of physical resource blocks (PRBs) for a given numerology. A PRB can be selected from a contiguous subset of common resource blocks (CRBs) for a given numerology on a given carrier.

[0099] FIG. 7 illustrates an example of a BWP according to an embodiment of the present disclosure. The embodiment of FIG. 7 can be combined with various embodiments of the present disclosure. In the embodiment of FIG. 7, it is assumed that there are three BWPs.

[0100] Referring to Figure 7, a common resource block (CRB) may be a carrier resource block numbered from one end of a carrier band to the other. Furthermore, a PRB may be a numbered resource block within each BWP. Point A may indicate a common reference point for the resource block grid.

[0101] BWP is point A, offset from point A (N start BWP ) and bandwidth (N size BWP ) can be set by. For example, point A can be an outer reference point of the PRB of a carrier where subcarrier 0 of all numerologies (e.g., all numerologies supported by the network on that carrier) aligns. For example, the offset can be the PRB spacing between the lowest subcarrier in a given numerology and point A. For example, the bandwidth can be the number of PRBs in a given numerology.

[0102] SLSS (Sidelink Synchronization Signal) is a SL (sidelink) specific sequence and may include PSSS (Primary Sidelink Synchronization Signal) and SSSS (Secondary Sidelink Synchronization Signal). The PSSS may be referred to as S-PSS (Sidelink Primary Synchronization Signal) and the SSSS may be referred to as S-SSS (Sidelink Secondary Synchronization Signal). For example, length-127 M-sequences may be used for S-PSS and length-127 Gold sequences may be used for S-SSS. For example, a terminal may detect an initial signal (signal detection) and obtain synchronization using S-PSS. For example, the terminal can obtain detailed synchronization using S-PSS and S-SSS and detect a synchronization signal ID.

[0103] PSBCH (Physical Sidelink Broadcast Channel) may be a (broadcast) channel that transmits basic (system) information that a terminal must know first before transmitting or receiving an SL signal. For example, the basic information may be information related to SLSS, duplex mode (DM), TDD UL / DL (Time Division Duplex Uplink / Downlink) configuration, resource pool-related information, type of application related to SLSS, subframe offset, broadcast information, etc. For example, in order to evaluate PSBCH performance, in NR V2X, the payload size of PSBCH may be 56 bits, including a 24-bit CRC (Cyclic Redundancy Check).

[0104] S-PSS, S-SSS and PSBCH may be included in a block format supporting periodic transmission (e.g., SL SS (Synchronization Signal) / PSBCH block, hereinafter referred to as S-SSB (Sidelink-Synchronization Signal Block)). The S-SSB may have the same numerology (i.e., SCS and CP length) as the PSCCH (Physical Sidelink Control Channel) / PSSCH (Physical Sidelink Shared Channel) in the carrier, and the transmission bandwidth may be within a (pre-)configured SL BWP (Sidelink BWP). For example, the bandwidth of the S-SSB may be 11 RBs (Resource Blocks). For example, the PSBCH may span 11 RBs. And, the frequency location of the S-SSB may be (pre-)configured. Therefore, the terminal does not need to perform hypothesis detection in the frequency to discover the S-SSB in the carrier.

[0105] In this specification, PSCCH may be replaced by a control channel, a physical control channel, a sidelink-related control channel, a sidelink-related physical control channel, etc. In this specification, PSSCH may be replaced by a shared channel, a physical shared channel, a sidelink-related shared channel, a sidelink-related physical shared channel, etc.

[0106] FIG. 8 illustrates a procedure for a terminal to perform V2X or SL communication according to a resource allocation mode, according to one embodiment of the present disclosure. The embodiment of FIG. 8 may be combined with various embodiments of the present disclosure.

[0107] Referring to (a) of FIG. 8, in resource allocation mode 1, the base station may schedule SL resources to be used by the terminal for SL transmission. For example, in step S800, the base station may transmit information related to SL resources and / or information related to UL resources to the first terminal. For example, the UL resources may include PUCCH resources and / or PUSCH resources. For example, the UL resources may be resources for reporting SL HARQ feedback to the base station.

[0108] For example, a first terminal may receive information related to a dynamic grant (DG) resource and / or information related to a configured grant (CG) resource from a base station. For example, a CG resource may include a CG type 1 resource or a CG type 2 resource. In this specification, a DG resource may be a resource that a base station configures / allocates to the first terminal via downlink control information (DCI). In this specification, a CG resource may be a (periodic) resource that a base station configures / allocates to the first terminal via DCI and / or an RRC message. For example, in the case of a CG type 1 resource, the base station may transmit an RRC message including information related to the CG resource to the first terminal. For example, in the case of a CG type 2 resource, the base station may transmit an RRC message including information related to the CG resource to the first terminal, and the base station may transmit a DCI related to activation or release of the CG resource to the first terminal.

[0109] In step S810, the first terminal may transmit a PSCCH (e.g., Sidelink Control Information (SCI) or 1st-stage SCI) to the second terminal based on the resource scheduling. In step S820, the first terminal may transmit a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) related to the PSCCH to the second terminal. In step S830, the first terminal may receive a PSFCH related to the PSCCH / PSSCH from the second terminal. For example, HARQ feedback information (e.g., NACK information or ACK information) may be received from the second terminal via the PSFCH. In step S840, the first terminal may transmit / report HARQ feedback information to the base station via a PUCCH or a PUSCH. For example, the HARQ feedback information reported to the base station may be information generated by the first terminal based on the HARQ feedback information received from the second terminal. For example, the HARQ feedback information reported to the base station may be information generated by the first terminal based on a rule set in advance. For example, the DCI may be DCI for scheduling SL.

[0110] Referring to (b) of FIG. 8, in resource allocation mode 2, the terminal can determine SL transmission resources within SL resources set by the base station / network or preset SL resources. For example, the set SL resources or preset SL resources may be a resource pool. For example, the terminal can autonomously select or schedule resources for SL transmission. For example, the terminal can perform SL communication by selecting resources by itself within the set resource pool. For example, the terminal can select resources by itself within a selection window by performing sensing and resource (re)selection procedures. For example, the sensing can be performed on a subchannel basis. For example, in step S810, the first terminal that has selected resources by itself within the resource pool transmits PSCCH (e.g., SCI (Sidelink Control Information) or 1) using the resources. st -stage SCI) can be transmitted to the second terminal. In step S820, the first terminal transmits the PSSCH (e.g., 2) related to the PSCCH. nd -stage SCI, MAC PDU, data, etc.) can be transmitted to the second terminal. In step S830, the first terminal can receive a PSFCH related to the PSCCH / PSSCH from the second terminal.

[0111] Referring to (a) or (b) of FIG. 8, for example, a first terminal may transmit an SCI to a second terminal on a PSCCH. Or, for example, the first terminal may transmit two consecutive SCIs (e.g., 2-stage SCIs) to the second terminal on the PSCCH and / or the PSSCH. In this case, the second terminal may decode the two consecutive SCIs (e.g., 2-stage SCIs) to receive the PSSCH from the first terminal. In the present specification, an SCI transmitted on a PSCCH is 1 st SCI, 1st SCI, 1st -stage SCI or 1 st -stage SCI format, and the SCI transmitted on the PSSCH is 2 nd SCI, 2nd SCI, 2 nd -stage SCI or 2 nd -It can be called a stage SCI format.

[0112] Referring to (a) or (b) of FIG. 8, in step S830, the first terminal may receive a PSFCH. For example, the first terminal and the second terminal may determine PSFCH resources, and the second terminal may use the PSFCH resources to transmit HARQ feedback to the first terminal.

[0113] Referring to (a) of FIG. 8, in step S840, the first terminal may transmit SL HARQ feedback to the base station via PUCCH and / or PUSCH.

[0114] Below, a wireless communication system supporting unlicensed bands (shared spectrum) is described.

[0115] FIG. 9 illustrates an example of a wireless communication system supporting an unlicensed band, according to an embodiment of the present disclosure. For example, FIG. 9 may include an unlicensed spectrum (NR-U) wireless communication system. The embodiment of FIG. 9 may be combined with various embodiments of the present disclosure.

[0116] In the following description, a cell operating in a licensed band (hereinafter, L-band) can be defined as an LCell, and the carrier of the LCell can be defined as a (DL / UL / SL) LCC. In addition, a cell operating in an unlicensed band (hereinafter, U-band) can be defined as an UCell, and the carrier of the UCell can be defined as a (DL / UL / SL) UCC. The carrier / carrier-frequency of a cell can mean the operating frequency (e.g., center frequency) of the cell. A cell / carrier (e.g., CC) is collectively referred to as a cell.

[0117] As shown in (a) of Fig. 9, when a terminal and a base station transmit and receive signals through carrier-aggregated LCC and UCC, the LCC may be set to PCC (Primary CC) and the UCC may be set to SCC (Secondary CC). As shown in (b) of Fig. 9, the terminal and base station may transmit and receive signals through one UCC or multiple carrier-aggregated UCCs. In other words, the terminal and base station may transmit and receive signals only through UCC(s) without LCC. For standalone operation, PRACH, PUCCH, PUSCH, SRS transmission, etc. may be supported in the UCell.

[0118] In the embodiment of FIG. 9, the base station may be replaced by a terminal. In this case, for example, PSCCH, PSSCH, PSFCH, S-SSB transmission, etc. may be supported in UCell.

[0119] Unless otherwise stated, the definitions below apply to terms used in this specification.

[0120] - Channel: Consists of consecutive RBs on which channel access procedures are performed in a shared spectrum, and may refer to a carrier or a portion of a carrier.

[0121] - Channel Access Procedure (CAP): This refers to the procedure for evaluating channel availability based on sensing to determine whether other communication nodes are using the channel before signal transmission. The basic unit for sensing is T sl =9us duration sensing slot. The base station or terminal senses the channel during the sensing slot period, and the power detected for at least 4us within the sensing slot period is the energy detection threshold X Thresh If it is smaller than T, the sensing slot interval is sl is considered to be idle. Otherwise, the sensing slot interval T sl =9us is considered a busy state. CAP can be referred to as LBT (Listen-Before-Talk).

[0122] - Channel occupancy: refers to the corresponding transmission(s) on the channel(s) by the base station / terminal after performing the channel access procedure.

[0123] - Channel Occupancy Time (COT): This refers to the total time that the base station / terminal and any base station / terminal(s) sharing the channel occupancy can perform transmission(s) on the channel after the base station / terminal performs the channel access procedure. When determining the COT, if the transmission gap is 25us or less, the gap period is also counted in the COT. The COT can be shared for transmission between the base station and the corresponding terminal(s).

[0124] - DL Transmission Burst: Defined as a set of transmissions from a base station without gaps exceeding 16us. Transmissions from a base station separated by gaps exceeding 16us are considered separate DL transmission bursts. A base station may perform transmission(s) after a gap without sensing channel availability within a DL transmission burst.

[0125] - UL or SL Transmission Burst: Defined as a set of transmissions from a terminal without a gap exceeding 16us. Transmissions from a terminal separated by a gap exceeding 16us are considered separate UL or SL transmission bursts. A terminal may perform transmission(s) after a gap without sensing channel availability within a UL or SL transmission burst.

[0126] - Discovery burst: refers to a DL transmission burst that includes a set of signal(s) and / or channel(s) that is limited within a (time) window and associated with a duty cycle. In an LTE-based system, a discovery burst is a transmission(s) initiated by a base station, including PSS, SSS and CRS (cell-specific RS), and may further include a non-zero power CSI-RS. In an NR-based system, a discovery burst is a transmission(s) initiated by a base station, including at least an SS / PBCH block, and may further include a CORESET for a PDCCH scheduling a PDSCH having SIB1, a PDSCH carrying SIB1, and / or a non-zero power CSI-RS.

[0127] FIG. 10 illustrates a method for occupying resources within an unlicensed band, according to one embodiment of the present disclosure. The embodiment of FIG. 10 may be combined with various embodiments of the present disclosure.

[0128] Referring to FIG. 10, a communication node (e.g., a base station, a terminal) within an unlicensed band must determine whether other communication node(s) are using the channel before transmitting a signal. To this end, the communication node within the unlicensed band may perform a channel access procedure (CAP) to access the channel(s) on which the transmission(s) are performed. The channel access procedure may be performed based on sensing. For example, the communication node may first perform carrier sensing (CS) before transmitting a signal to determine whether other communication node(s) are transmitting a signal. If it is determined that other communication node(s) are not transmitting a signal, it is defined that CCA (Clear Channel Assessment) is confirmed. A CCA threshold (e.g., X) that is predefined or set by a higher layer (e.g., RRC) Thresh ), the communication node can determine the channel state as busy if energy higher than the CCA threshold is detected in the channel, and determine the channel state as idle otherwise. If the channel state is determined to be idle, the communication node can start transmitting signals in the unlicensed band. CAP can be replaced with LBT.

[0129] Table 3 illustrates the channel access procedures (CAPs) supported in NR-U.

[0130] Type Description DL Type 1 CAP A CAP that performs a random back-off - the time duration over which the sensing slots are detected as idle before a downlink transmission is random. Type 2 CAP - Types 2A, 2B, 2C A CAP that does not perform a random back-off - the time duration over which the sensing slots are detected as idle before a downlink transmission is deterministic. UL or SL Type 1 CAP A CAP that performs a random back-off - the time duration over which the sensing slots are detected as idle before a uplink or sidelink transmission is random. Type 2 CAP - Types 2A, 2B, 2C A CAP that does not perform a random back-off - uplink Or the time duration spanning the sensing slot detected as idle before sidelink transmission is deterministic.

[0131] Referring to Table 3, LBT types or CAPs for DL / UL / SL transmissions can be defined. However, Table 3 is only an example, and new types or CAPs can be defined in a similar manner. For example, Type 1 (also called Cat-4 LBT) can be a random back-off based channel access procedure. For example, in the case of Cat-4, the contention window can be changed. For example, Type 2 can be performed in case of COT sharing within COT acquired by gNB or UE.

[0132] Below, LBT-SB (SubBand) (or RB set) is described.

[0133] In a wireless communication system supporting an unlicensed band, a cell (or carrier (e.g., CC)) or BWP configured for a terminal may be configured as a wideband with a larger BW (BandWidth) than that of the existing LTE. However, the BW for which CCA based on independent LBT operation is required may be limited due to regulations, etc. If a sub-band (SB) on which individual LBT is performed is defined as an LBT-SB, multiple LBT-SBs may be included in a single wideband cell / BWP. The RB set constituting the LBT-SB may be configured through higher layer (e.g., RRC) signaling. Therefore, one or more LBT-SBs may be included in a single cell / BWP based on (i) the BW of the cell / BWP and (ii) RB set allocation information.

[0134] FIG. 11 illustrates a case in which multiple LBT-SBs are included within an unlicensed band, according to one embodiment of the present disclosure. The embodiment of FIG. 11 may be combined with various embodiments of the present disclosure.

[0135] Referring to Fig. 11, a BWP of a cell (or carrier) may include multiple LBT-SBs. An LBT-SB may have, for example, a 20MHz band. An LBT-SB is composed of multiple consecutive (P)RBs in the frequency domain, which may be referred to as a (P)RB set. Although not shown, a guard band (GB) may be included between LBT-SBs. Accordingly, a BWP may be composed in the form of {LBT-SB #0 (RB set #0) + GB #0 + LBT-SB #1 (RB set #1 + GB #1) + ... + LBT-SB #(K-1) (RB set (#K-1))}. For convenience, the LBT-SB / RB index may be set / defined to increase starting from a lower frequency band and moving to a higher frequency band.

[0136] Below, CAPC (channel access priority class) is explained.

[0137] The MAC CEs and CAPCs of the radio bearers are fixed or configurable to operate in FR1:

[0138] - Fixed to lowest priority for padding BSR (buffer status report) and recommended bit rate MAC CE;

[0139] - Fixed to highest priority for SRB0, SRB1, SRB3 and other MAC CEs;

[0140] - Configured by the base station for SRB2 and DRB.

[0141] When selecting a CAPC for a DRB, the base station considers the 5QIs of all QoS flows multiplexed to the DRB, while also considering fairness among other traffic types and transmissions. Table 4 shows which CAPC to use for a standardized 5QI, i.e., which CAPC to use for a given QoS flow. For standardized 5QIs, CAPCs are defined as shown in the table below, and for non-standardized 5QIs, the CAPC that best aligns with the QoS characteristics should be used.

[0142] CAPC5QI11, 3, 5, 65, 66, 67, 69, 70, 79, 80, 82, 83, 84, 8522, 7, 7134, 6, 8, 9, 72, 73, 74, 764 - Note: Lower CAPC values ​​indicate higher priority

[0143] Below, a method for transmitting downlink signals via an unlicensed band is described. For example, this method for transmitting downlink signals via an unlicensed band can be applied to a method for transmitting sidelink signals via an unlicensed band.

[0144] A base station may perform one of the following channel access procedures (CAP) for downlink signal transmission in an unlicensed band.

[0145] (1) Type 1 downlink (DL) CAP method

[0146] In Type 1 DL CAP, the length of the time interval spanned by the sensing slots that are sensed as idle before transmission(s) is random. Type 1 DL CAP can be applied to the following transmissions:

[0147] - (i) a unicast PDSCH having user plane data, or (ii) a transmission(s) initiated by a base station, including a unicast PDSCH having user plane data and a unicast PDCCH scheduling user plane data, or

[0148] - Transmission(s) initiated by a base station, either (i) having only a discovery burst, or (ii) having a discovery burst multiplexed with non-unicast information.

[0149] FIG. 12 illustrates a CAP operation for downlink signal transmission through an unlicensed band of a base station according to an embodiment of the present disclosure. The embodiment of FIG. 12 may be combined with various embodiments of the present disclosure.

[0150] Referring to Figure 12, the base station first determines the defer duration T d During the sensing slot period, the channel is sensed to be in an idle state, and if the counter N becomes 0, transmission can be performed (S134). At this time, the counter N is adjusted by sensing the channel during additional sensing slot period(s) according to the following procedure:

[0151] Step 1)(S120) N=N init Set to . Here, N init Silver 0 to CW p It is a random value that is evenly distributed among them. Then, move on to step 4.

[0152] Step 2) (S140) If N>0 and the base station chooses to decrement the counter, set N=N-1.

[0153] Step 3) (S150) The channel is sensed during the additional sensing slot period. If the additional sensing slot period is idle (Y), proceed to Step 4. If not (N), proceed to Step 5.

[0154] Step 4) (S130) If N=0 (Y), terminate the CAP procedure (S132). Otherwise (N), proceed to Step 2.

[0155] Step 5)(S160) Additional delay section T d A busy sensing slot is detected within the frame, or an additional delay interval T d Sensing the channel until all sensing slots within it are detected as idle.

[0156] Step 6)(S170) Additional delay section T d If the channel is sensed as idle during all sensing slot intervals (Y), go to step 4. Otherwise (N), go to step 5.

[0157] Table 5 shows the m applied to CAP according to the channel access priority class. p , minimum contention window (CW), maximum CW, maximum channel occupancy time (MCOT), and allowed CW sizes are shown.

[0158] Channel Access Priority Class (p)m p CW min,p CW max,p T mcot,p Allowed CW p Size 11372 ms{3,7}217153 ms{7,15}3315638 or 10 ms{15,31,63}471510238 or 10 ms{15,31,63,127,255,511,1023}

[0159] Referring to Table 5, the contention window size (CWS) and maximum COT value for each CAPC can be defined. For example, T d = T f + m p * T sl It could be.

[0160] Delay interval T dis the section T f (16us) + m p A continuous sensing slot interval T of a dog sl It is composed of the order of (9us). T f is the sensing slot interval T at the start of the 16us interval. sl Includes.

[0161] CW min,p <= CW p <= CW max,p It is. CW p is CW p = CW min,p is set to , and can be updated (CW size update) prior to step 1 based on the HARQ-ACK feedback (e.g., ACK or NACK ratio) for the previous DL burst (e.g., PDSCH). For example, CW p is based on the HARQ-ACK feedback for the previous DL burst, CW min,p It can be initialized to , incremented to the next highest allowed value, or kept at the existing value.

[0162] (2) Type 2 downlink (DL) CAP method

[0163] In Type 2 DL CAP, the length of the time interval spanned by the sensing slots that are sensed as idle before transmission(s) is deterministic. Type 2 DL CAP is divided into Type 2A / 2B / 2C DL CAP.

[0164] Type 2A DL CAP can be applied to the transmissions below. In Type 2A DL CAP, the base station must have at least a sensing period T short_dl = Transmission can be transmitted immediately after the channel is sensed as idle for 25us. Here, T short_dl Silver section T f (=16us) and one sensing slot section immediately following it. T f contains a sensing slot at the start of the interval.

[0165] - transmission(s) initiated by the base station, (i) having only a discovery burst, or (ii) having a discovery burst multiplexed with non-unicast information, or,

[0166] - Transmission(s) by the base station after a 25us gap from the transmission(s) by the terminal within the shared channel occupancy.

[0167] Type 2B DL ​​CAP is applicable to transmission(s) performed by a base station after a 16us gap from transmission(s) by a terminal within the shared channel occupancy time. In Type 2B DL ​​CAP, the base station is T f =Transmission can be transmitted immediately after the channel is sensed as idle for 16us. T f Includes a sensing slot within the last 9us of the interval. Type 2C DL CAP is applicable to transmission(s) performed by the base station after a gap of up to 16us from transmission(s) by the terminal within the shared channel occupancy time. In Type 2C DL CAP, the base station does not sense the channel before performing a transmission.

[0168] Below, a method for transmitting uplink signals via an unlicensed band is described. For example, this method for transmitting uplink signals via an unlicensed band can be applied to a method for transmitting sidelink signals via an unlicensed band.

[0169] The UE performs Type 1 or Type 2 CAP for uplink signal transmission in the unlicensed band. Typically, the UE can perform the CAP (e.g., Type 1 or Type 2) configured by the base station for uplink signal transmission. For example, the UE may include CAP type indication information in the UL grant (e.g., DCI format 0_0, 0_1) that schedules PUSCH transmission.

[0170] (1) Type 1 uplink (UL) CAP method

[0171] In a Type 1 UL CAP, the length of the time interval spanned by the sensing slots that are sensed as idle before a transmission(s) is random. A Type 1 UL CAP can be applied to the following transmissions:

[0172] - Scheduled and / or configured PUSCH / SRS transmission(s) from the base station

[0173] - PUCCH transmission(s) scheduled and / or configured from the base station;

[0174] - Transmission(s) related to RAP (Random Access Procedure)

[0175] FIG. 13 illustrates a Type 1 CAP operation of a terminal for uplink signal transmission according to an embodiment of the present disclosure. The embodiment of FIG. 13 may be combined with various embodiments of the present disclosure.

[0176] Referring to Figure 13, the terminal first provides a defer duration T d During the sensing slot period, the channel is sensed to be in an idle state, and if the counter N becomes 0, transmission can be performed (S234). At this time, the counter N is adjusted by sensing the channel during additional sensing slot period(s) according to the following procedure:

[0177] Step 1)(S220) N=N init Set to . Here, N init Silver 0 to CW p It is a random value that is evenly distributed among them. Then, move on to step 4.

[0178] Step 2) (S240) If N>0 and the terminal chooses to decrement the counter, set N=N-1.

[0179] Step 3) (S250) The channel is sensed during the additional sensing slot section. If the additional sensing slot section is idle (Y), proceed to Step 4. If not (N), proceed to Step 5.

[0180] Step 4) (S230) If N=0 (Y), terminate the CAP procedure (S232). Otherwise (N), proceed to Step 2.

[0181] Step 5) (S260) Additional delay section T d A busy sensing slot is detected within the frame, or an additional delay interval T d Sensing the channel until all sensing slots within it are detected as idle.

[0182] Step 6)(S270) Additional delay section T d If the channel is sensed as idle during all sensing slot intervals (Y), go to step 4. Otherwise (N), go to step 5.

[0183] Table 6 shows the m applied to CAP according to the channel access priority class. p , minimum CW, maximum CW, maximum channel occupancy time (MCOT), and allowed CW sizes vary.

[0184] Channel Access Priority Class (p)m p CW min,p CW max,p T ulmcot,p Allowed CW p Size 12372 ms{3,7}227154 ms{7,15}331510236 or 10 ms{15,31,63,127,255,511,1023}471510236 or 10 ms{15,31,63,127,255,511,1023}

[0185] Referring to Table 6, the contention window size (CWS) and maximum COT value for each CAPC can be defined. For example, T d = T f + m p * T sl It could be.

[0186] Delay interval T d is the section T f (16us) + m p A continuous sensing slot interval T of a dog sl It is composed of the order of (9us). T f is the sensing slot interval T at the start of the 16us interval. sl Includes.

[0187] CW min,p <= CW p <= CW max,p It is. CW p is CW p = CW min,p is set to , and can be updated (CW size update) prior to step 1 based on explicit / implicit reception acknowledgment for the previous UL burst (e.g., PUSCH). For example, CW p is based on explicit / implicit reception acknowledgment to the previous UL burst, CW min,p It can be initialized to , incremented to the next highest allowed value, or kept at the existing value.

[0188] (2) Type 2 uplink (UL) CAP method

[0189] In Type 2 UL CAP, the length of the time interval spanned by the sensing slots that are sensed as idle before transmission(s) is deterministic. Type 2 UL CAP is divided into Type 2A / 2B / 2C UL CAP. In Type 2A UL CAP, the terminal must sense at least the sensing interval T short_dl= Transmission can be transmitted immediately after the channel is sensed as idle for 25us. Here, T short_dl Silver section T f (=16us) and one sensing slot section immediately following it. T in Type 2A UL CAP f includes a sensing slot at the start of the interval. In Type 2B UL CAP, the terminal starts sensing interval T f = Transmission can be transmitted immediately after the channel is sensed as idle for 16us. T in Type 2B UL CAP f contains a sensing slot within the last 9us of the interval. In Type 2C UL CAP, the terminal does not sense the channel before performing a transmission.

[0190] For example, according to Type 1 LBT-based NR-U operation, a terminal having uplink data to transmit can select a CAPC mapped to the 5QI of the data, and the terminal can set parameters of the CAPC (e.g., minimum contention window size, max contention window size, m p ) can be applied to perform NR-U operation. For example, the terminal can select a random value between the minimum CW and the maximum CW mapped to the CAPC and then select the BC (Backoff Counter). In this case, for example, the BC can be a positive integer less than or equal to the random value. The terminal that senses the channel decreases the BC by 1 when the channel is idle. When the BC becomes zero and the terminal is in T d (T d = T f + m p * T sl ) If the terminal detects that the channel is idle for a period of time, it can attempt to occupy the channel and transmit data. For example, T sl(= 9 usec) is a basic sensing unit or sensing slot, which may include a measurement duration of at least 4 usec. For example, T f The first 9 usec of (= 16 usec) is T sl can be composed of. For example, m p can be a constant mapped by CAPC, and T d can be used in calculations. For example, m p The lower the CAPC value (or the higher the priority), the smaller the value can be mapped.

[0191] For example, according to Type 2 LBT-based NR-U operation, a terminal can perform data transmission by performing Type 2 LBT (e.g., Type 2A LBT, Type 2B LBT, Type 2C LBT) within the COT.

[0192] For example, Type 2A (also called Cat-2 LBT (one shot LBT) or one-shot LBT) can be a 25 usec one-shot LBT. In this case, transmission can start immediately after idle sensing for at least a 25 usec gap. Type 2A can be used to initiate SSB and non-unicast DL information transmission. That is, the terminal can sense the channel for 25 usec within the COT, and the terminal can attempt to occupy the channel and transmit data when the channel is idle.

[0193] For example, Type 2B can be a 16-usec one-shot LBT. In this case, transmission can begin immediately after idle sensing for a 16-usec gap. That is, the terminal can sense the channel for 16 usec within the COT, and when the channel is idle, the terminal can seize the channel and attempt to transmit data.

[0194] For example, in the case of Type 2C (also called Cat-1 LBT or No LBT), LBT may not be performed. In this case, transmission may start immediately after a gap of up to 16 usec and may not sense the channel before the transmission. The duration of the transmission may be up to 584 usec. The terminal may attempt to transmit after 16 usec without sensing, and the terminal may transmit for up to 584 usec.

[0195] In a sidelink unlicensed band, a terminal can perform a channel access operation based on LBT (Listen Before Talk). Before accessing a channel in an unlicensed band, the terminal must check whether the access channel is idle (e.g., a state in which the terminal does not occupy the channel, a state in which terminals can access the channel and transmit data) or busy (e.g., a state in which the channel is occupied and data transmission and reception operations are performed on the channel, a terminal attempting to access the channel cannot transmit data when the channel is busy). In other words, the operation in which the terminal checks whether the channel is idle or busy can be referred to as CCA (Clear Channel Assessment), and the terminal can check whether the channel is idle or busy during the CCA period.

[0196] FIG. 14 illustrates a channel access procedure according to an embodiment of the present disclosure. Specifically, FIG. 14 (a) illustrates an example of a dynamic channel access procedure (load-based equipment, LBE), and FIG. 14 (b) illustrates an example of a semi-static channel access procedure (frame-based equipment, FBE). The embodiment of FIG. 14 may be combined with various embodiments of the present disclosure.

[0197] Referring to Figure 14 (a), a terminal can compete with other unlicensed band terminals to immediately occupy a channel when the channel is idle. Once a terminal occupies the channel, it can transmit data.

[0198] Referring to (b) of FIG. 14, a terminal can compete with other unlicensed band terminals at the last point (e.g., a certain time (or starting point) before the start of the next FFP) within a synchronized frame boundary (or Fixed Frame Period (FFP)). Then, if the terminal occupies the channel within the Fixed Frame Period (FFP), the terminal can transmit data. The data transmission must be completed before the start of the next FFP. Within the FFP, a Type 2 series LBT operation (e.g., without performing LBT based on random backoff, sensing the channel for a certain short time and transmitting data when the channel is idle) can be performed.

[0199] Meanwhile, in the sidelink-unlicensed band (SL-U), a terminal must first occupy a channel in the sidelink unlicensed band to transmit SL data. For example, to occupy a channel in the sidelink unlicensed band, the terminal can perform listen before talk (LBT) (e.g., type 1 LBT: LBT based on random backoff) to find a channel in the unlicensed band that is not occupied by other terminals. For example, if a terminal performing LBT finds a channel that is not occupied by other terminals, it can occupy the channel and perform SL data transmission. For example, if the LBT process fails, the terminal can adjust the parameter values ​​for performing LBT (e.g., adjusting the size of the contention window, etc.) to (re)perform LBT, and continue the process of finding a channel in the unlicensed band that is not occupied by the terminal.

[0200] For example, a transmitting terminal performing sidelink communication in SL-U can perform an LBT operation to occupy a channel in an unlicensed band. For example, if the LBT is successful, the terminal can transmit packets on the occupied channel. For example, if the LBT fails (e.g., if the terminal detects that the channel is busy as a result of sensing during the sensing slot period), the terminal cannot perform sidelink transmission because it failed to occupy a channel in the unlicensed band. In addition, for example, if the MAC layer of the transmitting terminal detects an SL LBT failure while performing an LBT operation to occupy a channel in the unlicensed band, the MAC layer can receive an indication of an SL LBT failure event from the PHY (physical) layer.

[0201] Meanwhile, in SL-U, the terminal can perform actions based on SL LBT failure events as follows.

[0202] For example, the terminal may receive the following parameters for SL LBT failure management from the base station, and perform an SL LBT failure recovery operation or an SL LBT failure declaration operation.

[0203] - sl-lbt-FailureInstanceMaxCount: When the terminal detects an SL LBT failure, it can increase SL_LBT_COUNTER by 1, and when it detects SL LBT failures up to sl-lbt-FailureInstanceMaxCount before sl-lbt-FailureDetectionTimer expires, it can declare an SL LBT failure.

[0204] - sl-lbt-FailureDetectionTimer: A timer that starts when an SL LBT failure is detected. The SL LBT failure recovery process can be performed while the timer is running.

[0205] For example, when the MAC layer of a transmitting terminal receives an SL LBT failure event from the PHY layer (e.g., when the terminal detects an SL LBT failure), it may start the sl-lbt-FailureDetectionTimer timer and simultaneously increase the SL_LBT_COUNTER by 1. In addition, for example, the SL LBT recovery process may be performed while the sl-lbt-FailureDetectionTimer timer is running. For example, if the terminal detects an SL LBT failure again while the sl-lbt-FailureDetectionTimer timer is running, the terminal may increase the SL_LBT_COUNTER by 1. For example, if the SL_LBT_COUNTER incremented due to SL LBT failure detection does not reach the threshold number of times (sl-lbt-FailureInstanceMaxCount) before the sl-lbt-FailureDetectionTimer timer expires, the UE can consider the SL LBT failure to have been recovered and can continue to perform normal sidelink communication using the sidelink grant in use.

[0206] However, for example, if the incremented SL_LBT_COUNTER due to SL LBT failure detection reaches a threshold number of times (sl-lbt-FailureInstanceMaxCount) before the sl-lbt-FailureDetectionTimer timer expires, the SL LBT failure may be considered unrecovered and a consistent SL LBT failure may be declared. Additionally, for example, the transmitting terminal may declare an SL LBT failure if the SL LBT failure is not recovered before the sl-lbt-FailureDetectionTimer timer expires.

[0207] Meanwhile, the terminal may perform the following resource (re)selection procedure when operating based on MCSt (multiple consecutive slots transmission) (e.g., operating the terminal when MCSt resources are allocated).

[0208] For reference, for example, MCSt may mean allocating consecutive sidelink (SL) slots less than a certain gap as transmission resources for sidelink transmission, and a terminal may transmit the same sidelink transport block (TB) (e.g., single TB) or multiple sidelink TBs (e.g., multiple TBs) using multiple consecutive slots.

[0209] Additionally, for example, the terminal may perform LBT in the first slot and transmit the sidelink TB without performing LBT for the sidelink TB transmitted through the subsequent consecutive slots (e.g., consecutive slots with a gap less than a certain gap).

[0210] For example, when performing MCSt-based sidelink transmission, sidelink data can be transmitted without performing LBT during the gap between consecutive slots for sidelink transmission, thereby reducing the overhead of transmission operations (e.g., performing LBT) in the sidelink unlicensed band.

[0211] Meanwhile, in the prior art, the resource selected by the terminal for sidelink TB transmission from the resource pool in which the PSFCH is set must maintain a minimum time gap between the two resources (e.g., a certain gap between the PSFCH linked to the PSSCH, a certain gap between the PSFCH associated with the PSSCH and the next PSSCH resource, or a certain gap between two resources (e.g., between the PSSCH and the PSSCH)).

[0212] Meanwhile, according to the prior art, if the PSFCH received for PSSCH transmission is a positive ACK, the HARQ buffer can be flushed and the grant can be cleared. In addition, PSFCH resources can be set in the resource pool only when transmitting multiple MAC PDUs (or multiple TBs) based on MCSt. However, in this case, the following problems may occur.

[0213] For example, in a case where multiple consecutive slots are configured to perform MCSt-based transmission for multiple MAC PDUs (or multiple TBs) (e.g., one or more slots are configured for each of multiple MAC PDUs and the configured slots are consecutive (e.g., the gap between consecutive slots is 16 usec or less)), when HARQ feedback (positive ACK) is received for any one of the multiple MAC PDUs transmitted based on any one of the multiple consecutive slots, the HARQ buffer may be flushed and the grant may be cleared according to the above-described conventional technology even if there is a slot for the MAC PDU remaining among the multiple consecutive slots. In this case, a problem may occur in that transmission of MAC PDUs other than the MAC PDU for which the positive ACK was received among the multiple MAC PDUs can no longer be performed based on MCSt. Alternatively, for example, if the HARQ buffer is flushed or the grant is cleared based on the reception of a positive ACK before all of the multiple consecutive slots for MCSt are used, the gap between the multiple consecutive slots may exceed 16 usec, which may cause the MCSt structure to become untenable.Or, for example, if a terminal creates an MCSt structure in an unlicensed band to transmit multiple MAC PDUs by performing only one type 1 LBT, and then flushes a related HARQ buffer or clears a grant due to reception of a positive ACK for one of the transmitted MAC PDUs, the terminal may need to perform resource selection again, perform type 1 LBT again, or create an MCSt structure again to transmit another MAC PDU that was scheduled to be transmitted based on the MCSt structure, which may increase overhead of the terminal and reduce efficiency related to the use of transmission resources in the unlicensed band.

[0214] In the present disclosure, a method for performing a retransmission operation / HARQ buffer management operation / sidelink grant management operation based on reception of HARQ feedback from a terminal during SL TB transmission (e.g., multiple TBs transmission or single TB transmission) using MCSt resources and a device supporting the same are proposed as follows.

[0215] As in the embodiment(s) below, when a terminal performs MCSt-based SL TB transmission consisting of four consecutive slots (e.g., performing four transmissions (initial transmission and retransmission) in four slots for one SL TB) (where the number of consecutive slots for MCSt is "4"), if HARQ feedback (e.g., positive ACK (acknowledgement)) is received in the transmission(s) of four consecutive slots, the terminal may perform the following actions.

[0216] For reference, according to the prior art, when a terminal performs MCSt-based SL TB transmission consisting of four consecutive slots (e.g., performing four transmissions (initial transmission and retransmission) in four slots for one SL TB) when the terminal receives feedback (e.g., positive ACK) for the first slot transmission of MCSt, it can transmit a retransmission packet in the remaining three slots so as not to waste MCSt resources.

[0217] Below, the embodiments of FIGS. 15 to 19 illustrate the operation of the terminal proposed in the present disclosure.

[0218] FIG. 15 illustrates a retransmission operation / HARQ buffer management operation / sidelink grant management operation based on reception of HARQ feedback by a terminal during MCSt-based SL TB transmission according to an embodiment of the present disclosure. The embodiment of FIG. 15 may be combined with various embodiments of the present disclosure.

[0219] Referring to FIG. 15, when a terminal performs MCSt-based SL TB transmission consisting of four consecutive slots (e.g., performing four transmissions (initial transmission and retransmission) in four slots for one SL TB) when the terminal receives HARQ feedback (e.g., positive ACK) (1512) for the first slot transmission (1511) of MCSt, the terminal can transmit a retransmission packet (1521) in the next second slot. And, when the terminal receives HARQ feedback (e.g., positive ACK) (1522) for the second slot transmission (1521), the terminal can transmit a retransmission packet (1531) in the next third slot. And, when receiving HARQ feedback (e.g., positive ACK) (1532) for this third slot transmission (1531), the terminal can transmit a retransmission packet (1541) in the next fourth slot. And, when receiving HARQ feedback (e.g., positive ACK) (1542) for this fourth slot transmission (1541), the terminal can flush (1551) the HARQ buffer related to the sidelink process for SL TB transmission using this MCSt resource, and perform an operation of clearing (1552) the sidelink grant generated for this SL TB transmission.

[0220] For example, when a terminal transmits an SL TB to a counterpart terminal in each slot among four consecutive slots for MCSt (multiple consecutive slots transmission) and receives a positive ACK from the counterpart terminal, but there is a slot for the SL TB remaining among the slots for MCSt after the positive ACK received by the terminal (e.g., each case in which positive ACKs 1512, 1522, and 1532 are received in the embodiment of FIG. 15), the HARQ buffer related to the sidelink process for transmitting the SL TB may not be flushed, and the sidelink grant generated for transmitting the SL TB may not be cleared. And, for example, if there is no slot for the SL TB left after the positive ACK received by the terminal from the counterpart terminal among the slots for the MCSt (e.g., if a positive ACK (1542) is received in the embodiment of FIG. 15), the HARQ buffer related to the sidelink process for transmitting the SL TB can be flushed, and the sidelink grant generated for transmitting the SL TB can be cleared.

[0221] Additionally, since the resource pool in which the PSFCH resource for receiving HARQ feedback is set can be set only when transmitting multiple TBs with MCSt, the embodiment related to transmission of the above-described SL TB can be interpreted as an embodiment related to transmission of multiple TBs.

[0222] Specifically, the embodiment of FIG. 15 described above may be as follows (see FIG. 16 and FIG. 17).

[0223] FIG. 16 illustrates an operation for managing HARQ buffers and grants associated with an SL TB when receiving HARQ feedback for MCSt-based SL TB transmission according to an embodiment of the present disclosure. The embodiment of FIG. 16 may be combined with various embodiments of the present disclosure.

[0224] Referring to FIG. 16, an MCSt resource (1600) consisting of eight consecutive slots may be configured for a transmitting terminal to transmit multiple SL TBs (TB A and TB B in FIG. 16) based on MCSt. For example, four slots (1611, 1612, 1613, and 1614) may be configured for transmitting TB A among the MCSt resources, and four slots (1621, 1622, 1623, and 1624) may be configured for transmitting TB B. Meanwhile, the transmitting terminal may obtain configuration information (e.g., SL-ResourcePool) related to a resource pool in which PSFCH resources are configured based on an RRC message. For example, the configuration information related to the resource pool may include PSFCH resource configuration information (e.g., SL-PSFCH-Config), and the PSFCH resource configuration information may include information related to a configuration period of the PSFCH resource (e.g., sl-PSFCH-Period) and information related to a minimum time gap between the PSSCH and the PSFCH (e.g., sl-MinTimeGapPSFCH).

[0225] Meanwhile, for example, the transmitting terminal can perform LBT (Type 1 LBT) on the first slot (1611) of the MCSt resources to occupy an idle channel and then transmit TB A to the counterpart terminal (and, only Type 2 LBT can be performed and transmission can be performed on slots after the first slot). For example, if the counterpart terminal succeeds in decoding TB A transmitted on the first slot (1611), it can transmit HARQ feedback (positive ACK) for TB A transmitted on the first slot (1611) to the transmitting terminal. In this case, for example, if PSFCH resources are set every two slots (e.g., sl-PSFCH-Period: 2) and the minimum time gap between PSSCH and PSFCH is set to two slots (e.g., sl-MinTimeGapPSFCH: 2), the transmitting terminal can receive HARQ feedback (positive ACK) (1630) for TB A transmitted on the first slot (1611) based on PSFCH resources included in the fourth slot (1622), which is the slot located earliest among slots including PSFCH resources two slots after the first slot (1611), rather than the second slot (1621) including PSFCH resources among MCSt resources (1600). For example, the transmitting terminal can determine whether there are slot(s) remaining for TB A among the MCSt resources (1600) consisting of the eight slots after receiving HARQ feedback (positive ACK) (1630) for TB A.For example, if slot(s) for TB A remain (1613 and 1614) after HARQ feedback (positive ACK) (1630) for TB A is received among the MCSt resources (1600) consisting of the above 8 slots, the HARQ buffer associated with the SL process for transmission of TB A cannot be flushed. And, for example, the grant for transmission of TB A cannot be cleared.

[0226] For example, even if slot(s) for TB A remain (1613 and 1614) after HARQ feedback (positive ACK) (1630) for TB A transmitted on the first slot (1611) is received, if the HARQ buffer associated with the SL process for transmission of TB A is flushed or the grant for transmission of TB A is cleared, the structure of the MCSt resource (1600) consisting of the eight consecutive slots cannot be maintained. For example, if the HARQ buffer associated with the transmission of any one of the multiple TBs is flushed or the grant is cleared, the gap between consecutive slots for MCSt will exceed 16usec, so that the structure of MCSt can no longer be maintained (e.g., to perform transmission for the remaining TBs, LBT (Type 1 LBT) must be performed again first). Therefore, as described above, if the transmitting terminal determines that there are slot(s) remaining for TB A among the MCSt resources (1600) consisting of the eight slots after the HARQ feedback (positive ACK) (1630) for TB A is received (1613 and 1614), the transmitting terminal cannot flush the HARQ buffer associated with the SL process for the transmission of TB A, and cannot clear the grant for the transmission of TB A.

[0227] Meanwhile, the transmitting terminal may perform retransmission for TB A in the fifth slot (1613) after receiving the HARQ feedback (positive ACK) (1630). For example, if the counterpart terminal succeeds in decoding TB A transmitted on the fifth slot (1613), it may transmit HARQ feedback (positive ACK) for TB A transmitted on the fifth slot (1613) to the transmitting terminal. In this case, as described above, the HARQ feedback (positive ACK) for TB A transmitted on the fifth slot (1613) may be received based on the PSFCH resource included in the eighth slot (1624), which is the slot located earliest among the slots including PSFCH resources two slots after the fifth slot. In this case, as described above, the transmitting terminal can determine whether there are any remaining slot(s) for TB A among the MCSt resources (1600) consisting of the eight slots after HARQ feedback (positive ACK) for TB A is received. For example, if there are no more remaining slot(s) for TB A after HARQ feedback (positive ACK) for TB A transmitted on the fifth slot (1613) among the MCSt resources (1600) consisting of the eight slots is received, the transmitting terminal can flush the HARQ buffer associated with the SL process for transmission of TB A and clear the grant for transmission of TB A.In summary, when a transmitting terminal receives a positive ACK for a TB transmitted on any one of the consecutive slots for MCSt, it can flush the HARQ buffer associated with the SL process for transmission of the TB, except when there are slot(s) for the TB remaining among the consecutive slots for MCSt, and can also clear the grant for transmission of the TB.

[0228] Meanwhile, for example, unlike as described above, the transmitting terminal may transmit TB A on the first slot (1611) of the MCSt resources and transmit TB B on the second slot (1621). And, for example, HARQ feedback (positive ACK) for TB A transmitted on the first slot (1611) may be received based on the PSFCH resource included in the fourth slot (1622), which is the slot located earliest among the slots including PSFCH resources two slots after the first slot (1611). And, for example, HARQ feedback (positive ACK) for TB B transmitted on the second slot (1621) may be received based on the PSFCH resource included in the sixth slot (1623), which is the slot located earliest among the slots including PSFCH resources two slots after the second slot (1621). In this case, for example, the transmitting terminal can determine that both transmissions for the TBs (TB A and TB B) to be transmitted based on MCSt were successful. Therefore, for example, even if there are slots (1614) for TB A and slots (1624) for TB B remaining after the fourth slot (1622) including the PSFCH resource in which the positive ACK for TB A is received and the sixth slot (1623) including the PSFCH resource in which the positive ACK for TB B is received, the transmitting terminal can flush the HARQ buffer associated with the SL process for transmission of TB A and the HARQ buffer associated with the SL process for transmission of TB B, and clear the grant for transmission of TB A and the grant for transmission of TB B.In this case, for example, unlike the above, since both TB A and TB B transmitted based on MCSt are successfully received and the MCSt structure no longer needs to be maintained, the HARQ buffer can be flushed or the grant can be cleared even if slots remain in the MCSt resource.

[0229] FIG. 17 illustrates an operation for managing HARQ buffers and grants associated with an SL TB when receiving HARQ feedback for MCSt-based SL TB transmission according to an embodiment of the present disclosure. The embodiment of FIG. 17 may be combined with various embodiments of the present disclosure.

[0230] Referring to FIG. 17, an MCSt resource (1700) consisting of 12 consecutive slots may be set for a transmitting terminal to transmit multiple SL TBs (TB A, TB B, TB C, and TB D in FIG. 17) based on MCSt. For example, among the MCSt resources, three slots (1711, 1712, and 1713) may be set for transmission of TB A, three slots (1721, 1722, and 1723) may be set for transmission of TB B, three slots (1731, 1732, and 1733) may be set for transmission of TB C, and three slots (1741, 1742, and 1743) may be set for transmission of TB D. Meanwhile, the transmitting terminal may obtain configuration information (e.g., SL-ResourcePool) related to a resource pool in which PSFCH resources are configured based on an RRC message. For example, the configuration information related to the resource pool may include PSFCH resource configuration information (e.g., SL-PSFCH-Config), and the PSFCH resource configuration information may include information related to a configuration period of PSFCH resources (e.g., sl-PSFCH-Period) and information related to a minimum time gap between PSSCH and PSFCH (e.g., sl-MinTimeGapPSFCH).

[0231] Meanwhile, for example, the transmitting terminal can perform LBT (Type 1 LBT) on the first slot (1711) of the MCSt resources to occupy an idle channel and then transmit TB A to the counterpart terminal (and, only Type 2 LBT can be performed and transmission can be performed on slots after the first slot). For example, if the counterpart terminal succeeds in decoding TB A transmitted on the first slot (1711), it can transmit HARQ feedback (positive ACK) for TB A transmitted on the first slot (1711) to the transmitting terminal. In this case, for example, if PSFCH resources are set every four slots (e.g., sl-PSFCH-Period: 4) and the minimum time gap between PSSCH and PSFCH is set to three slots (e.g., sl-MinTimeGapPSFCH: 3), the transmitting terminal can receive HARQ feedback (positive ACK) (1750) for TB A transmitted on the first slot (1711) based on PSFCH resources included in the eighth slot (1742), which is the slot located earliest among slots including PSFCH resources three slots after the first slot (1711), rather than the fourth slot (1741) including PSFCH resources among MCSt resources (1700). For example, the transmitting terminal can determine whether there are slot(s) remaining for TB A among the MCSt resources (1700) consisting of the 12 slots after receiving HARQ feedback (positive ACK) (1750) for TB A.For example, if slot(s) for TB A remain (1713) after HARQ feedback (positive ACK) (1750) for TB A is received among MCSt resources (1700) consisting of the 12 slots, the HARQ buffer associated with the SL process for transmission of TB A cannot be flushed. And, for example, the grant for transmission of TB A cannot be cleared.

[0232] For example, even if there are slot(s) remaining for TB A (1713) after HARQ feedback (positive ACK) (1750) for TB A transmitted on the first slot (1711) is received, if the HARQ buffer associated with the SL process for transmission of TB A is flushed or the grant for transmission of TB A is cleared, the structure of the MCSt resource (1700) consisting of the 12 consecutive slots cannot be maintained. For example, if the HARQ buffer associated with transmission of any one of the multiple TBs is flushed or the grant is cleared, the gap between consecutive slots for MCSt exceeds 16usec, and thus the structure of MCSt cannot be maintained any longer (e.g., to perform transmission for the remaining TBs, LBT (Type 1 LBT) must be performed again first). Accordingly, as described above, if the transmitting terminal determines that there are slot(s) remaining for TB A among the MCSt resources (1700) consisting of the 12 slots after receiving HARQ feedback (positive ACK) (1750) for TB A (1713), the transmitting terminal cannot flush the HARQ buffer related to the SL process for transmission of TB A, and cannot clear the grant for transmission of TB A.

[0233] Meanwhile, the transmitting terminal may perform retransmission for TB A in the fifth slot (1712). For example, if the counterpart terminal succeeds in decoding TB A transmitted on the fifth slot (1712), it may transmit HARQ feedback (positive ACK) for TB A transmitted on the fifth slot (1712) to the transmitting terminal. In this case, as described above, the HARQ feedback (positive ACK) for TB A transmitted on the fifth slot (1712) may be received based on the PSFCH resource included in the twelfth slot (1743), which is the earliest slot among the slots including PSFCH resources three slots after the fifth slot. In this case, as described above, the transmitting terminal can determine whether there are any remaining slot(s) for TB A among the MCSt resources (1700) consisting of the 12 slots after HARQ feedback (positive ACK) for TB A is received. For example, if there are no more remaining slot(s) for TB A after HARQ feedback (positive ACK) for TB A transmitted on the fifth slot (1712) among the MCSt resources (1700) consisting of the 12 slots is received, the transmitting terminal can flush the HARQ buffer associated with the SL process for transmission of TB A and clear the grant for transmission of TB A.In summary, when a transmitting terminal receives a positive ACK for a TB transmitted on any one of the consecutive slots for MCSt, it can flush the HARQ buffer associated with the SL process for transmission of the TB, except when there are slot(s) for the TB remaining among the consecutive slots for MCSt, and can also clear the grant for transmission of the TB.

[0234] FIG. 18 illustrates a retransmission operation / HARQ buffer management operation / sidelink grant management operation based on the reception of HARQ feedback by a terminal during MCSt-based SL TB transmission according to an embodiment of the present disclosure. The embodiment of FIG. 18 may be combined with various embodiments of the present disclosure.

[0235] Referring to FIG. 18, when a terminal performs MCSt-based SL TB transmission consisting of four consecutive slots (e.g., performing four transmissions (initial transmission and retransmission) in four slots for one SL TB) when the number of consecutive slots for MCSt is "4", if HARQ feedback (e.g., negative ACK) (1812) is received for the first slot transmission (1811) of MCSt, the terminal can transmit a retransmission packet (1821) in the next second slot. And, if HARQ feedback (e.g., negative ACK) (1822) is received for this second slot transmission (1821), the terminal can transmit a retransmission packet (1831) in the next third slot. And, when receiving HARQ feedback (e.g., negative ACK) (1832) for this third slot transmission (1831), the terminal can transmit a retransmission packet (1841) in the next fourth slot. And, when receiving HARQ feedback (e.g., positive ACK) (1842) for this fourth slot transmission (1841), the terminal can flush (1851) the HARQ buffer related to the sidelink process for SL TB transmission using this MCSt resource, and perform an operation of clearing (1852) the sidelink grant generated for this SL TB transmission.

[0236] FIG. 19 illustrates a retransmission operation / HARQ buffer management operation / sidelink grant management operation based on the reception of HARQ feedback by a terminal during MCSt-based SL TB transmission according to an embodiment of the present disclosure. The embodiment of FIG. 19 may be combined with various embodiments of the present disclosure.

[0237] Referring to FIG. 19, when a terminal performs MCSt-based SL TB transmission consisting of four consecutive slots (e.g., performing four transmissions (initial transmission and retransmission) in four slots for one SL TB) when the number of consecutive slots for MCSt is "4", if HARQ feedback (e.g., negative ACK) (1912) is received for the first slot transmission (1911) of MCSt, the terminal can transmit a retransmission packet (1921) in the next second slot. And, if HARQ feedback (e.g., negative ACK) (1922) is received for this second slot transmission (1921), the terminal can transmit a retransmission packet (1931) in the next third slot. And, when HARQ feedback (e.g., negative ACK) (1932) is received for this third slot transmission (1931), the terminal can transmit a retransmission packet (1941) in the next fourth slot. And, when HARQ feedback (e.g., negative ACK) (1942) is received for this fourth slot transmission (1941), the terminal can flush (1951) the HARQ buffer related to the sidelink process for SL TB transmission using this MCSt resource, and perform an operation of clearing (1952) the sidelink grant generated for this SL TB transmission.

[0238] The term “channel” as specified in this disclosure may be replaced with “carrier” or “set of resource blocks (RBs) of a specific carrier” or “band”.

[0239] For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds) may be set specifically (or differently or independently) for SL-Channel Access Priority Class (CAPC). For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds) may be set specifically (or differently or independently) for SL-LBT types (e.g., Type 1 LBT, Type 2A LBT, Type 2B LTB, Type 2C LBT). For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds) may be set specifically (or differently or independently) depending on whether FBE (Frame Based LBT) is applied. For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or the relevant parameters (e.g., thresholds) may be set specifically (or differently or independently) depending on whether LBE (Load Based LBT) is applied.

[0240] For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or their associated parameters (e.g., thresholds) can be set resource pool-specifically (or differently or independently). For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or their associated parameters (e.g., thresholds) can be set congestion level-specifically (or differently or independently). For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or their associated parameters (e.g., thresholds) can be set service priority-specifically (or differently or independently). For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or their associated parameters (e.g., thresholds) can be set service type-specifically (or differently or independently). For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds) can be set specifically (or differently or independently) for QoS requirements (e.g., latency, reliability). For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds) can be set specifically (or differently or independently) for PQI (5QI (5G QoS identifier) ​​for PC5). For example, whether (some) of the proposed methods / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds) can be set specifically (or differently or independently) for traffic types (e.g., periodic generation or aperiodic generation).

[0241] For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be specifically (or differently or independently) set depending on whether the Uu bandwidth part is activated / deactivated. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be specifically (or differently or independently) set depending on whether the sidelink bandwidth part is activated / deactivated. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be specifically (or differently or independently) set depending on whether the sidelink logical channel / logical channel group (or Uu logical channel or Uu logical channel group) is activated. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be specifically (or differently or independently) set depending on initial transmission resource selection. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for retransmission resource selection. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) depending on whether PUCCH configuration is supported (e.g., when PUCCH resources are configured or when PUCCH resources are not configured). For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for a resource pool (e.g., a resource pool where PSFCH is configured or a resource pool where PSFCH is not configured). For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for a type of service / packet.For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for the priority of the service / packet. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for a QoS profile or QoS requirement (e.g., URLLC / EMBB traffic, reliability, latency). For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for a PQI. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for a PFI. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for a cast type (e.g., unicast, groupcast, broadcast). For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for a (resource pool) congestion level (e.g., CBR). For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for a SL HARQ feedback scheme (e.g., NACK-only feedback, ACK / NACK feedback). For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for HARQ Feedback Enabled MAC PDU transmission. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set specifically (or differently or independently) for HARQ Feedback Disabled MAC PDU transmission.For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be specifically (or differently or independently) set depending on whether a PUCCH-based SL HARQ feedback reporting operation is set. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be specifically (or differently or independently) set depending on whether pre-emption or pre-emption-based resource reselection is performed. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be specifically (or differently or independently) set depending on whether re-evaluation or re-evaluation-based resource reselection is performed. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be specifically (or differently or independently) set depending on (L2 or L1) (source and / or destination) identifiers. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set identifier-specifically (or differently or independently) for (L2 or L1) (a combination of source ID and destination ID). For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set identifier-specifically (or differently or independently) for (L2 or L1) (a combination of a pair of source ID and destination ID and a cast type). For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set direction-specifically (or differently or independently) for a pair of source layer ID and destination layer ID. For example, whether the proposed rule of the present disclosure applies and / or the related parameter setting values ​​can be set PC5 RRC connection / link-specifically (or differently or independently).For example, whether the proposed rule of the present disclosure is applicable and / or the related parameter setting values ​​can be specifically (or differently or independently) set depending on whether SL DRX is performed. For example, whether the proposed rule of the present disclosure is applicable and / or the related parameter setting values ​​can be specifically (or differently or independently) set depending on whether SL DRX is supported. For example, whether the proposed rule of the present disclosure is applicable and / or the related parameter setting values ​​can be specifically (or differently or independently) set depending on the SL mode type (e.g., resource allocation mode 1 or resource allocation mode 2). For example, whether the proposed rule of the present disclosure is applicable and / or the related parameter setting values ​​can be specifically (or differently or independently) set depending on the case of performing (aperiodic) resource reservation. For example, whether the proposed rules of the present disclosure are applicable and / or the related parameter setting values ​​can be set specifically (or differently or independently) for a Tx profile (e.g., a Tx profile indicating that the service supports sidelink DRX operation or a Tx profile indicating that the service does not need to support sidelink DRX operation).

[0242] The applicability of the proposals and proposed rules of the present disclosure (and / or the associated parameter settings) may also be applied to mmWave SL operation.

[0243] According to various embodiments of the present disclosure, when a plurality of consecutive slots are set to perform MCSt-based transmission for a plurality of MAC PDUs (or a plurality of multiple TBs), even if a positive ACK is received for any one of the plurality of MAC PDUs transmitted based on any one of the plurality of consecutive slots, if at least one slot for the MAC PDU related to the received positive ACK remains among the plurality of consecutive slots, a HARQ buffer related to an SL process for transmission of the MAC PDU may not be flushed and a grant for the MAC PDU may not be cleared. For example, when multiple MAC PDUs are transmitted based on MCSt, even if a positive ACK is received for any one of the multiple MAC PDUs, the HARQ buffer can be flushed and the grant for the MAC PDU can be cleared only when multiple consecutive slots for the MCSt are all used. In this case, for example, since the transmission remainder can continue to maintain the multiple consecutive slot structure (e.g., MCSt structure) configured to transmit multiple MAC PDUs, MCSt transmission based on Type 2 LBT can continue to be performed without additionally performing Type 1 LBT for transmission of the remaining MAC PDUs. Accordingly, the transmitting terminal can continue to transmit while maintaining the existing MCSt structure, so that transmission resources of the unlicensed band can be efficiently used, and overhead of the transmitting terminal that may occur due to performing the new Type 1 LBT can be reduced.

[0244] FIG. 20 illustrates a method for a first device to perform wireless communication according to an embodiment of the present disclosure. The embodiment of FIG. 20 may be combined with various embodiments of the present disclosure.

[0245] Referring to FIG. 20, in step S2010, a first device may transmit first data to a second device based on a first slot among slots for multiple consecutive slot transmission. In step S2020, the first device may receive a positive ACK (acknowledgement) for the first data from the second device. In step S2030, the first device may flush a hybrid automatic repeat request (HARQ) buffer of a sidelink process related to the first data, except that at least one slot for the first data remains among the slots for the multiple consecutive slot transmissions, based on the positive ACK for the first data.

[0246] For example, the HARQ buffer may be flushed based on the first slot in which the first data is transmitted being the last slot among the slots for the plurality of consecutive slot transmissions.

[0247] For example, the first data may be included in at least one of a plurality of transport blocks (TBs) or a plurality of medium access control (MAC) protocol data units (PDUs) transmitted based on the plurality of consecutive slot transmissions.

[0248] For example, the time duration during which sensing is performed to access a resource included in the first slot among the slots for the plurality of consecutive slot transmissions may be random.

[0249] For example, based on access to resources included in the first slot among the slots for the plurality of consecutive slot transmissions, channel access to resources included in slots after the first slot among the slots can be performed without performing sensing during a random time interval.

[0250] For example, the gap between slots for the above multiple consecutive slot transmissions may be less than a threshold.

[0251] For example, based on receiving all positive ACKs for each of the plurality of data, including the first data transmitted based on each slot of the slots for the plurality of consecutive slot transmissions, a grant for each of the plurality of data may be cleared, and a sidelink process associated with each of the plurality of data may be flushed.

[0252] For example, based on the first data being transmitted through a physical sidelink shared channel (PSSCH) within the first slot, the positive ACK may be received on a physical sidelink feedback channel (PSFCH) resource included in a slot after a minimum time gap from the PSSCH among slots for the plurality of consecutive slot transmissions.

[0253] For example, based on the PSFCH resource being set for reception of the positive ACK in the resource pool, the plurality of consecutive slot transmissions for the plurality of data including the first data can be performed.

[0254] For example, the HARQ buffer may be flushed except that at least one slot for the first data remains after a slot containing a PSFCH resource associated with reception of the positive ACK for the first data among the slots for the plurality of consecutive slot transmissions.

[0255] Additionally, for example, the first device may clear a grant for the first data, based on the positive ACK for the first data, except that at least one slot for the first data remains among the slots for the plurality of consecutive slot transmissions. For example, the grant may be cleared based on the first slot in which the first data is transmitted among the slots for the plurality of consecutive slot transmissions being the last slot among the slots for the plurality of consecutive slot transmissions. For example, the grant may be cleared except that at least one slot for the first data remains after a slot including a PSFCH resource associated with reception of the positive ACK for the first data among the slots for the plurality of consecutive slot transmissions.

[0256] The proposed method can be applied to devices according to various embodiments of the present disclosure. First, the processor (102) of the first device (100) can control the transceiver (106) to transmit first data to the second device based on the first slot among slots for multiple consecutive slot transmission. Then, the processor (102) of the first device (100) can control the transceiver (106) to receive a positive ACK (acknowledgement) for the first data from the second device. And, the processor (102) of the first device (100) may flush a hybrid automatic repeat request (HARQ) buffer of a sidelink process related to the first data, except that at least one slot for the first data remains among the slots for the plurality of consecutive slot transmissions, based on the positive ACK for the first data.

[0257] According to one embodiment of the present disclosure, a first device configured to perform wireless communication may be provided. For example, the first device may include at least one transceiver; at least one processor; and at least one memory coupled to the at least one processor and storing instructions. For example, the instructions, when executed by the at least one processor, may cause the first device to: transmit first data to a second device based on a first slot among slots for multiple consecutive slot transmissions; receive a positive ACK (acknowledgement) for the first data from the second device; and, based on the positive ACK for the first data, flush a hybrid automatic repeat request (HARQ) buffer of a sidelink process associated with the first data except that at least one slot for the first data remains among the slots for the multiple consecutive slot transmissions.

[0258] According to one embodiment of the present disclosure, a processing device configured to control a first device may be provided. For example, the processing device may include at least one processor; and at least one memory coupled to the at least one processor and storing instructions. For example, the instructions, when executed by the at least one processor, may cause the first device to: transmit first data to a second device based on a first slot among slots for multiple consecutive slot transmissions; receive a positive ACK (acknowledgement) for the first data from the second device; and, based on the positive ACK for the first data, flush a hybrid automatic repeat request (HARQ) buffer of a sidelink process associated with the first data except that at least one slot for the first data remains among the slots for the multiple consecutive slot transmissions.

[0259] According to one embodiment of the present disclosure, a non-transitory computer-readable storage medium having instructions recorded thereon may be provided. For example, the instructions, when executed, may cause a first device to: transmit first data to a second device based on a first slot among slots for multiple consecutive slot transmissions; receive a positive acknowledgment (ACK) for the first data from the second device; and, based on the positive ACK for the first data, flush a hybrid automatic repeat request (HARQ) buffer of a sidelink process associated with the first data except that at least one slot for the first data remains among the slots for the multiple consecutive slot transmissions.

[0260] FIG. 21 illustrates a method for a second device to perform wireless communication according to an embodiment of the present disclosure. The embodiment of FIG. 21 may be combined with various embodiments of the present disclosure.

[0261] Referring to FIG. 21, in step S2110, the second device may receive first data from the first device based on a first slot among slots for multiple consecutive slot transmission. In step S2120, the second device may generate a positive ACK (acknowledgement) for the first data based on successful decoding of the first data. In step S2130, the second device may transmit the positive ACK for the first data to the first device. For example, based on the positive ACK for the first data, a hybrid automatic repeat request (HARQ) buffer of a sidelink process related to the first data may be flushed, except that at least one slot for the first data remains among the slots for the multiple consecutive slot transmission.

[0262] The proposed method can be applied to devices according to various embodiments of the present disclosure. First, the processor (202) of the second device (200) can control the transceiver (206) to receive first data from the first device based on a first slot among slots for multiple consecutive slot transmission. Then, the processor (202) of the second device (200) can generate a positive ACK (acknowledgement) for the first data based on the successful decoding of the first data. Then, the processor (202) of the second device (200) can control the transceiver (206) to transmit the positive ACK for the first data to the first device.

[0263] According to one embodiment of the present disclosure, a second device configured to perform wireless communication may be provided. For example, the second device may include at least one transceiver; at least one processor; and at least one memory coupled to the at least one processor and storing instructions. For example, the instructions, based on execution by the at least one processor, may cause the second device to: receive first data from the first device based on a first slot among slots for multiple consecutive slot transmissions; generate a positive acknowledgment (ACK) for the first data based on successful decoding of the first data; and transmit the positive ACK for the first data to the first device. For example, based on the positive ACK for the first data, a hybrid automatic repeat request (HARQ) buffer of a sidelink process related to the first data may be flushed, except that at least one slot for the first data remains among the slots for the plurality of consecutive slot transmissions.

[0264] According to one embodiment of the present disclosure, a processing device configured to control a second device may be provided. For example, the processing device may include at least one processor; and at least one memory coupled to the at least one processor and storing instructions. For example, the instructions, when executed by the at least one processor, may cause the second device to: receive first data from the first device based on a first slot among slots for multiple consecutive slot transmissions; generate a positive acknowledgment (ACK) for the first data based on a successful decoding of the first data; and transmit the positive ACK for the first data to the first device. For example, based on the positive ACK for the first data, a hybrid automatic repeat request (HARQ) buffer of a sidelink process related to the first data may be flushed, except that at least one slot for the first data remains among the slots for the plurality of consecutive slot transmissions.

[0265] According to one embodiment of the present disclosure, a non-transitory computer-readable storage medium having instructions recorded thereon may be provided. For example, the instructions, when executed, may cause a second device to: receive first data from a first device based on a first slot among slots for multiple consecutive slot transmissions; generate a positive acknowledgment (ACK) for the first data based on a successful decoding of the first data; and transmit the positive ACK for the first data to the first device. For example, based on the positive ACK for the first data, a hybrid automatic repeat request (HARQ) buffer of a sidelink process associated with the first data may be flushed except that at least one slot for the first data remains among the slots for the multiple consecutive slot transmissions.

[0266] The various embodiments of the present disclosure may be combined with each other.

[0267] Below, a description is given of devices to which various embodiments of the present disclosure can be applied.

[0268] Although not limited thereto, the various descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed in this document may be applied to various fields requiring wireless communication / connectivity (e.g., 5G) between devices.

[0269] Hereinafter, more specific examples will be provided with reference to the drawings. In the drawings / descriptions below, the same drawing reference numerals may represent identical or corresponding hardware blocks, software blocks, or functional blocks, unless otherwise described.

[0270] FIG. 22 illustrates a communication system (1) according to one embodiment of the present disclosure. The embodiment of FIG. 22 can be combined with various embodiments of the present disclosure.

[0271] Referring to FIG. 22, a communication system (1) to which various embodiments of the present disclosure are applied includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using a wireless access technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution)) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Things) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone) and / or an Aerial Vehicle (AV) (e.g., an Advanced Air Mobility (AAM)). The XR device may include an Augmented Reality (AR) / Virtual Reality (VR) / Mixed Reality (MR) device, and may be implemented in the form of a Head-Mounted Device (HMD), a Head-Up Display (HUD) equipped in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a robot, etc. The portable device may include a smartphone, a smart pad, a wearable device (e.g., a smart watch, smart glasses), a computer (e.g., a laptop, etc.), etc. The home appliance may include a TV, a refrigerator, a washing machine, etc. The IoT device may include a sensor, a smart meter, etc. For example, a base station and a network may also be implemented as a wireless device, and a specific wireless device (200a) may operate as a base station / network node to other wireless devices.

[0272] Here, the wireless communication technology implemented in the wireless devices (100a to 100f) of the present specification may include not only LTE, NR, and 6G, but also Narrowband Internet of Things for low-power communication. At this time, for example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology, and may be implemented with standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless devices (100a to 100f) of the present specification may perform communication based on LTE-M technology. At this time, for example, LTE-M technology may be an example of LPWAN technology, and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology can be implemented by at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless devices (100a to 100f) of the present specification can include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) considering low-power communication, and is not limited to the above-described names. For example, ZigBee technology can create personal area networks (PAN) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and can be called by various names.

[0273] Wireless devices (100a to 100f) can be connected to a network (300) via a base station (200). Artificial Intelligence (AI) technology can be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) via the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, etc. The wireless devices (100a to 100f) can communicate with each other via the base station (200) / network (300), but can also communicate directly (e.g., sidelink communication) without going through the base station / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to Everything) communication). In addition, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0274] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base stations (200), and base stations (200) / base stations (200). Here, wireless communication / connection can be achieved through various wireless access technologies (e.g., 5G NR) such as uplink / downlink communication (150a), sidelink communication (150b) (or, D2D communication), and communication between base stations (150c) (e.g., relay, IAB (Integrated Access Backhaul). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes can be performed based on various proposals of the present disclosure.

[0275] FIG. 23 illustrates a wireless device according to an embodiment of the present disclosure. The embodiment of FIG. 23 may be combined with various embodiments of the present disclosure.

[0276] Referring to FIG. 23, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals via various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device (100), the second wireless device (200)} can correspond to {the wireless device (100x), the base station (200)} and / or {the wireless device (100x), the wireless device (100x)} of FIG. 22.

[0277] A first wireless device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memories (104) and / or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (102) may process information in the memory (104) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (106). Furthermore, the processor (102) may receive a wireless signal including second information / signal via the transceiver (106), and then store information obtained from signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE, NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals via one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present disclosure, a wireless device may also mean a communication modem / circuit / chip.

[0278] A second wireless device (200) includes one or more processors (202), one or more memories (204), and may further include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memories (204) and / or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate third information / signals, and then transmit a wireless signal including the third information / signals via the transceivers (206). In addition, the processor (202) may receive a wireless signal including fourth information / signals via the transceivers (206), and then store information obtained from signal processing of the fourth information / signals in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may perform some or all of the processes controlled by the processor (202), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In the present disclosure, a wireless device may also mean a communication modem / circuit / chip.

[0279] Hereinafter, the hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed herein, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein.

[0280] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and executed by one or more processors (102, 202). The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0281] One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0282] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of this document, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of this document, from one or more other devices. For example, one or more transceivers (106, 206) can be connected to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein, via one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0283] FIG. 24 illustrates a signal processing circuit for a transmission signal according to an embodiment of the present disclosure. The embodiment of FIG. 24 can be combined with various embodiments of the present disclosure.

[0284] Referring to FIG. 24, the signal processing circuit (1000) may include a scrambler (1010), a modulator (1020), a layer mapper (1030), a precoder (1040), a resource mapper (1050), and a signal generator (1060). Although not limited thereto, the operations / functions of FIG. 24 may be performed in the processor (102, 202) and / or the transceiver (106, 206) of FIG. 23. The hardware elements of FIG. 24 may be implemented in the processor (102, 202) and / or the transceiver (106, 206) of FIG. 23. For example, blocks 1010 to 1060 may be implemented in the processor (102, 202) of FIG. 23. Additionally, blocks 1010 to 1050 may be implemented in the processor (102, 202) of FIG. 23, and block 1060 may be implemented in the transceiver (106, 206) of FIG. 23.

[0285] The codeword can be converted into a wireless signal through the signal processing circuit (1000) of FIG. 24. Here, the codeword is an encoded bit sequence of an information block. The information block may include a transport block (e.g., an UL-SCH transport block, a DL-SCH transport block). The wireless signal may be transmitted through various physical channels (e.g., a PUSCH or a PDSCH).

[0286] Specifically, the codeword can be converted into a bit sequence scrambled by a scrambler (1010). The scramble sequence used for scrambling is generated based on an initialization value, and the initialization value may include ID information of the wireless device, etc. The scrambled bit sequence can be modulated into a modulation symbol sequence by a modulator (1020). The modulation method may include pi / 2-BPSK (pi / 2-Binary Phase Shift Keying), m-PSK (m-Phase Shift Keying), m-QAM (m-Quadrature Amplitude Modulation), etc. The complex modulation symbol sequence can be mapped to one or more transmission layers by a layer mapper (1030). The modulation symbols of each transmission layer can be mapped to the corresponding antenna port(s) by a precoder (1040) (precoding). The output z of the precoder (1040) can be obtained by multiplying the output y of the layer mapper (1030) by a precoding matrix W of N*M. Here, N is the number of antenna ports, and M is the number of transmission layers. Here, the precoder (1040) can perform precoding after performing transform precoding (e.g., DFT transform) on complex modulation symbols. In addition, the precoder (1040) can perform precoding without performing transform precoding.

[0287] The resource mapper (1050) can map modulation symbols of each antenna port to time-frequency resources. The time-frequency resources can include multiple symbols (e.g., CP-OFDMA symbols, DFT-s-OFDMA symbols) in the time domain and multiple subcarriers in the frequency domain. The signal generator (1060) generates a wireless signal from the mapped modulation symbols, and the generated wireless signal can be transmitted to another device through each antenna. To this end, the signal generator (1060) can include an Inverse Fast Fourier Transform (IFFT) module, a Cyclic Prefix (CP) inserter, a Digital-to-Analog Converter (DAC), a frequency uplink converter, etc.

[0288] The signal processing process for receiving signals in a wireless device can be configured in reverse order of the signal processing process (1010 to 1060) of FIG. 24. For example, a wireless device (e.g., 100, 200 of FIG. 23) can receive wireless signals from the outside through an antenna port / transceiver. The received wireless signals can be converted into baseband signals through a signal restorer. For this purpose, the signal restorer can include a frequency downlink converter, an analog-to-digital converter (ADC), a CP remover, and a fast Fourier transform (FFT) module. Thereafter, the baseband signal can be restored to a codeword through a resource demapper process, a postcoding process, a demodulation process, and a descrambling process. The codewords can be restored to the original information blocks through decoding. Accordingly, a signal processing circuit (not shown) for a received signal may include a signal restorer, a resource de-mapper, a postcoder, a demodulator, a de-scrambler, and a decoder.

[0289] FIG. 25 illustrates a wireless device according to an embodiment of the present disclosure. The wireless device may be implemented in various forms depending on the use case / service (see FIG. 22). The embodiment of FIG. 25 may be combined with various embodiments of the present disclosure.

[0290] Referring to FIG. 25, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 23 and may be composed of various elements, components, units, and / or modules. For example, the wireless device (100, 200) may include a communication unit (110), a control unit (120), a memory unit (130), and an additional element (140). The communication unit may include a communication circuit (112) and a transceiver(s) (114). For example, the communication circuit (112) may include one or more processors (102, 202) and / or one or more memories (104, 204) of FIG. 23. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 23. The control unit (120) is electrically connected to the communication unit (110), the memory unit (130), and the additional elements (140) and controls the overall operation of the wireless device. For example, the control unit (120) may control the electrical / mechanical operation of the wireless device based on the program / code / command / information stored in the memory unit (130). In addition, the control unit (120) may transmit information stored in the memory unit (130) to an external device (e.g., another communication device) via a wireless / wired interface through the communication unit (110), or store information received from an external device (e.g., another communication device) via a wireless / wired interface in the memory unit (130).

[0291] The additional element (140) may be configured in various ways depending on the type of the wireless device. For example, the additional element (140) may include at least one of a power unit / battery, an input / output (I / O) unit, a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 22, 100a), a vehicle (Fig. 22, 100b-1, 100b-2), an XR device (Fig. 22, 100c), a portable device (Fig. 22, 100d), a home appliance (Fig. 22, 100e), an IoT device (Fig. 22, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, an AI server / device (Fig. 22, 400), a base station (Fig. 22, 200), a network node, etc. Wireless devices may be mobile or stationary depending on the use / service.

[0292] In FIG. 25, various elements, components, units / parts, and / or modules within the wireless device (100, 200) may be interconnected entirely via a wired interface, or at least some may be wirelessly connected via a communication unit (110). For example, within the wireless device (100, 200), the control unit (120) and the communication unit (110) may be wired, and the control unit (120) and the first unit (e.g., 130, 140) may be wirelessly connected via the communication unit (110). In addition, each element, component, unit / part, and / or module within the wireless device (100, 200) may further include one or more elements. For example, the control unit (120) may be composed of one or more processor sets. For example, the control unit (120) may be composed of a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of a random access memory (RAM), a dynamic RAM (DRAM), a read only memory (ROM), a flash memory, a volatile memory, a non-volatile memory, and / or a combination thereof.

[0293] Below, the implementation example of Fig. 25 is described in more detail with reference to the drawings.

[0294] FIG. 26 illustrates a mobile device according to an embodiment of the present disclosure. The mobile device may include a smartphone, a smart pad, a wearable device (e.g., a smartwatch, smartglasses), or a portable computer (e.g., a laptop, etc.). The mobile device may be referred to as a Mobile Station (MS), a User Terminal (UT), a Mobile Subscriber Station (MSS), a Subscriber Station (SS), an Advanced Mobile Station (AMS), or a Wireless Terminal (WT). The embodiment of FIG. 26 may be combined with various embodiments of the present disclosure.

[0295] Referring to FIG. 26, the portable device (100) may include an antenna unit (108), a communication unit (110), a control unit (120), a memory unit (130), a power supply unit (140a), an interface unit (140b), and an input / output unit (140c). The antenna unit (108) may be configured as a part of the communication unit (110). Blocks 110 to 130 / 140a to 140c correspond to blocks 110 to 130 / 140 of FIG. 25, respectively.

[0296] The communication unit (110) can transmit and receive signals (e.g., data, control signals, etc.) with other wireless devices and base stations. The control unit (120) can control components of the mobile device (100) to perform various operations. The control unit (120) can include an AP (Application Processor). The memory unit (130) can store data / parameters / programs / codes / commands required for operating the mobile device (100). In addition, the memory unit (130) can store input / output data / information, etc. The power supply unit (140a) supplies power to the mobile device (100) and can include a wired / wireless charging circuit, a battery, etc. The interface unit (140b) can support connection between the mobile device (100) and other external devices. The interface unit (140b) can include various ports (e.g., audio input / output ports, video input / output ports) for connection with external devices. The input / output unit (140c) can input or output video information / signals, audio information / signals, data, and / or information input from a user. The input / output unit (140c) may include a camera, a microphone, a user input unit, a display unit (140d), a speaker, and / or a haptic module.

[0297] For example, in the case of data communication, the input / output unit (140c) obtains information / signals (e.g., touch, text, voice, image, video) input by the user, and the obtained information / signals can be stored in the memory unit (130). The communication unit (110) converts the information / signals stored in the memory into wireless signals, and can directly transmit the converted wireless signals to other wireless devices or to a base station. In addition, the communication unit (110) can receive wireless signals from other wireless devices or base stations, and then restore the received wireless signals to the original information / signals. The restored information / signals can be stored in the memory unit (130) and then output in various forms (e.g., text, voice, image, video, haptic) through the input / output unit (140c).

[0298] Figure 27 illustrates a vehicle or autonomous vehicle according to one embodiment of the present disclosure. The vehicle or autonomous vehicle may be implemented as a mobile robot, a car, a train, a manned or unmanned aerial vehicle (AV), a ship, or the like. The embodiment of Figure 27 may be combined with various embodiments of the present disclosure.

[0299] Referring to FIG. 27, a vehicle or autonomous vehicle (100) may include an antenna unit (108), a communication unit (110), a control unit (120), a driving unit (140a), a power supply unit (140b), a sensor unit (140c), and an autonomous driving unit (140d). The antenna unit (108) may be configured as a part of the communication unit (110). Blocks 110 / 130 / 140a to 140d correspond to blocks 110 / 130 / 140 of FIG. 25, respectively.

[0300] The communication unit (110) can transmit and receive signals (e.g., data, control signals, etc.) with external devices such as other vehicles, base stations (e.g., base stations, road side units, etc.), and servers. The control unit (120) can control elements of the vehicle or autonomous vehicle (100) to perform various operations. The control unit (120) can include an ECU (Electronic Control Unit). The drive unit (140a) can drive the vehicle or autonomous vehicle (100) on the ground. The drive unit (140a) can include an engine, a motor, a power train, wheels, brakes, a steering device, etc. The power supply unit (140b) supplies power to the vehicle or autonomous vehicle (100) and can include a wired / wireless charging circuit, a battery, etc. The sensor unit (140c) can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit (140c) may include an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, an incline sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / backward sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit (140d) may implement a technology for maintaining a driving lane, a technology for automatically controlling speed such as adaptive cruise control, a technology for automatically driving along a set path, a technology for automatically setting a path and driving when a destination is set, etc.

[0301] For example, the communication unit (110) can receive map data, traffic information data, etc. from an external server. The autonomous driving unit (140d) can generate an autonomous driving route and driving plan based on the acquired data. The control unit (120) can control the drive unit (140a) so that the vehicle or autonomous vehicle (100) moves along the autonomous driving route according to the driving plan (e.g., speed / direction control). During autonomous driving, the communication unit (110) can irregularly / periodically acquire the latest traffic information data from an external server and can acquire surrounding traffic information data from surrounding vehicles. In addition, during autonomous driving, the sensor unit (140c) can acquire vehicle status and surrounding environment information. The autonomous driving unit (140d) can update the autonomous driving route and driving plan based on newly acquired data / information. The communication unit (110) can transmit information regarding the vehicle location, autonomous driving route, driving plan, etc. to the external server. External servers can predict traffic information data in advance using AI technology or other technologies based on information collected from vehicles or autonomous vehicles, and provide the predicted traffic information data to the vehicles or autonomous vehicles.

[0302] The claims set forth in this specification may be combined in various ways. For example, the technical features of the method claims of this specification may be combined and implemented as a device, and the technical features of the device claims of this specification may be combined and implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a device, and the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a method.

Claims

1. In terms of method, A step in which a first device transmits first data to a second device based on a first slot among slots for multiple consecutive slot transmission; A step of receiving a positive ACK (acknowledgement) for the first data from the second device; and A method comprising: a step of flushing a hybrid automatic repeat request (HARQ) buffer of a sidelink process related to the first data, except that at least one slot for the first data remains among the slots for the plurality of consecutive slot transmissions, based on the positive ACK for the first data; 2. In paragraph 1, A method in which the HARQ buffer is flushed based on the first slot in which the first data is transmitted being the last slot among the slots for the plurality of consecutive slot transmissions.

3. In paragraph 1, A method wherein the first data is included in at least one of a plurality of TBs (transport blocks) or a plurality of MAC (medium access control) PDUs (protocol data units) transmitted based on the plurality of consecutive slot transmissions.

4. In paragraph 1, A method wherein a time duration during which sensing is performed to access a resource included in the first slot among the slots for the plurality of consecutive slot transmissions is random.

5. In paragraph 1, A method in which channel access is performed for resources included in slots after the first slot among the slots for the plurality of consecutive slot transmissions, without performing sensing during a random time interval, based on access to resources included in the first slot among the slots.

6. In paragraph 1, A method wherein the gap between slots for the above multiple consecutive slot transmissions is less than or equal to a threshold value.

7. In paragraph 1, A method wherein a grant for each of the plurality of data is cleared and a sidelink process associated with each of the plurality of data is flushed based on reception of all positive ACKs for each of the plurality of data including the first data transmitted based on each slot of the slots for the plurality of consecutive slot transmissions.

8. In paragraph 1, A method in which the positive ACK is received on a PSFCH (physical sidelink feedback channel) resource included in a slot after a minimum time gap from the PSSCH among slots for the plurality of consecutive slot transmissions, based on the first data being transmitted through a PSSCH (physical sidelink shared channel) within the first slot.

9. In paragraph 1, A method in which a plurality of consecutive slot transmissions for a plurality of data including the first data are performed based on setting a PSFCH resource for reception of the positive ACK in a resource pool.

10. In paragraph 1, A method wherein the HARQ buffer is flushed, except that at least one slot for the first data remains after a slot including a PSFCH resource associated with reception of the positive ACK for the first data among the slots for the plurality of consecutive slot transmissions.

11. In paragraph 1, A method further comprising: a step of clearing a grant for the first data, except that at least one slot for the first data remains among the slots for the plurality of consecutive slot transmissions, based on the positive ACK for the first data.

12. In paragraph 11, A method wherein the grant is cleared based on the first slot in which the first data is transmitted being the last slot among the slots for the plurality of consecutive slot transmissions.

13. In paragraph 11, A method wherein the grant is cleared except that at least one slot for the first data remains after a slot including a PSFCH resource associated with reception of the positive ACK for the first data among the slots for the plurality of consecutive slot transmissions.

14. In a first device configured to perform wireless communication, At least one transceiver; at least one processor; and At least one memory coupled to said at least one processor and storing instructions, said instructions being executed by said at least one processor to cause said first device to: Transmitting first data to a second device based on a first slot among slots for multiple consecutive slot transmission; To receive a positive ACK (acknowledgement) for the first data from the second device; and A first device, based on the positive ACK for the first data, flushing a hybrid automatic repeat request (HARQ) buffer of a sidelink process related to the first data, except that at least one slot for the first data remains among the slots for the plurality of consecutive slot transmissions.

15. In a processing device set to control the first device, at least one processor; and At least one memory coupled to said at least one processor and storing instructions, said instructions being executed by said at least one processor to cause said first device to: Transmitting first data to a second device based on a first slot among slots for multiple consecutive slot transmission; To receive a positive ACK (acknowledgement) for the first data from the second device; and A processing device that flushes a hybrid automatic repeat request (HARQ) buffer of a sidelink process related to the first data, except that at least one slot for the first data remains among the slots for the plurality of consecutive slot transmissions, based on the positive ACK for the first data.

16. A non-transitory computer-readable storage medium that records commands, The above commands, when executed, cause the first device to: Transmitting first data to a second device based on a first slot among slots for multiple consecutive slot transmission; To receive a positive ACK (acknowledgement) for the first data from the second device; and A non-transitory computer-readable storage medium, which causes a HARQ (hybrid automatic repeat request) buffer of a sidelink process related to the first data to be flushed, except that at least one slot for the first data remains among the slots for the plurality of consecutive slot transmissions, based on the positive ACK for the first data.

17. In the method, A step in which a second device receives first data from a first device based on a first slot among slots for multiple consecutive slot transmission; A step of generating a positive ACK (acknowledgement) for the first data based on successful decoding of the first data; and A step of transmitting the positive ACK for the first data to the first device; comprising: A method wherein, based on the positive ACK for the first data, a hybrid automatic repeat request (HARQ) buffer of a sidelink process related to the first data is flushed, except that at least one slot for the first data remains among the slots for the plurality of consecutive slot transmissions.

18. In a second device configured to perform wireless communication, At least one transceiver; at least one processor; and At least one memory coupled to said at least one processor and storing instructions, said instructions causing said second device to: Receiving first data from a first device based on a first slot among slots for multiple consecutive slot transmission; Based on the successful decoding of the first data, generating a positive ACK (acknowledgement) for the first data; and To transmit the positive ACK for the first data to the first device, A second device, wherein, based on the positive ACK for the first data, a hybrid automatic repeat request (HARQ) buffer of a sidelink process related to the first data is flushed, except that at least one slot for the first data remains among the slots for the plurality of consecutive slot transmissions.

19. In a processing device set to control a second device, at least one processor; and At least one memory coupled to said at least one processor and storing instructions, said instructions causing said second device to: Receiving first data from a first device based on a first slot among slots for multiple consecutive slot transmission; Based on the successful decoding of the first data, generating a positive ACK (acknowledgement) for the first data; and To transmit the positive ACK for the first data to the first device, A processing device, wherein, based on the positive ACK for the first data, a hybrid automatic repeat request (HARQ) buffer of a sidelink process related to the first data is flushed, except that at least one slot for the first data remains among the slots for the plurality of consecutive slot transmissions.

20. A non-transitory computer-readable storage medium that records commands, The above commands, when executed, cause the second device to: Receiving first data from a first device based on a first slot among slots for multiple consecutive slot transmission; Based on the successful decoding of the first data, generating a positive ACK (acknowledgement) for the first data; and To transmit the positive ACK for the first data to the first device, A non-transitory computer-readable storage medium, wherein, based on the positive ACK for the first data, a hybrid automatic repeat request (HARQ) buffer of a sidelink process related to the first data is flushed, except that at least one slot for the first data remains among the slots for the plurality of consecutive slot transmissions.

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