Method and device for performing communication in wireless communication system

Abstract

A method for performing wireless communication by a first device, and a device for supporting same are provided The method may comprise the steps of: obtaining information relating to the maximum number of counts by which a listen-before-talk (LBT) failure has been detected; and on the basis that an LBT counter has a value greater than or equal to the maximum number of counts by which the LBT failure has been detected, continuously detecting the LBT failure. For example, on the basis that information about an LBT failure for a first resource block (RB) set is obtained, a first LBT counter may be incremented by a value of 1 for the first RB set. For example, on the basis that the first LBT counter is incremented by a value of 1 for the first RB set and that no guard band is configured between RB sets, a second LBT counter may be incremented by a value of 1 for a second RB set that is an RB set different from the first RB set.

Description

Method and device for performing communication in a wireless communication system

[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 rate1 TbpsE2E latency1 msMaximum spectral efficiency100bps / HzMobility supportUp to 1000km / hrSatellite integrationFullyAIFullyAutonomous vehicleFullyXRFullyHaptic CommunicationFully

[0005] The present disclosure provides a device and method for effectively providing services in a wireless communication system. In particular, the present disclosure provides a method and device for communication.

[0006] In one embodiment, a method performed by a first device may be provided. The method may include: obtaining information related to a maximum count for detecting listen before talk (LBT) failure; and detecting a persistent LBT failure based on an LBT counter being greater than or equal to the maximum count for detecting LBT failure. For example, a first LBT counter may be incremented by 1 for a first RB (resource block) set based on obtaining information about an LBT failure for the first RB set. For example, a second LBT counter may be incremented by 1 for a second RB set that is different from the first RB set based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that a guard band is not set between the RB sets.

[0007] In one embodiment, a first device configured to perform wireless communication may be 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, wherein the instructions, when executed by the at least one processor, cause the first device to: obtain information related to a maximum count for listen before talk (LBT) failure detection; and detect persistent LBT failures based on an LBT counter being greater than or equal to the maximum count for LBT failure detection. For example, the first LBT counter may be incremented by 1 for a first RB (resource block) set based on obtaining information related to an LBT failure for the first RB set. For example, the second LBT counter may be incremented by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that no guard band is set between the RB sets.

[0008] In one embodiment, a processing device configured to control a first device may be provided. The processing device may include 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: obtain information related to a maximum count for listen before talk (LBT) failure detection; and detect persistent LBT failures based on an LBT counter being greater than or equal to the maximum count for LBT failure detection. For example, a first LBT counter may be incremented by 1 for a first RB (resource block) set based on obtaining information related to an LBT failure for the first RB set. For example, the second LBT counter may be incremented by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that no guard band is set between the RB sets.

[0009] In one embodiment, a non-transitory computer-readable storage medium having instructions recorded thereon may be provided. The instructions, when executed, may cause a first device to: obtain information related to a maximum count for detecting listen before talk (LBT) failures; and detect persistent LBT failures based on an LBT counter being greater than or equal to the maximum count for detecting LBT failures. For example, a first LBT counter may be incremented by 1 for a first RB (resource block) set based on information about an LBT failure for the first RB set being obtained. For example, a second LBT counter may be incremented by 1 for a second RB set that is different from the first RB set based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that a guard band is not established between the RB sets.

[0010] In one embodiment, a method performed by a second device may be provided. The method may include: receiving, from a first device, control information for scheduling a physical shared channel on a physical control channel; and receiving, from the first device, data on the physical shared channel. For example, information related to a maximum count for listen before talk (LBT) failure detection may be acquired by the first device. For example, based on a failure in reception of the data due to an LBT failure, a first LBT counter for the first device may be incremented by 1 for a first RB set for which reception has failed. For example, a second LBT counter for the first device may be incremented by 1 for a second RB set that is different from the first RB set, based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that a guard band is not set between RB sets.

[0011] In one embodiment, a second device configured to perform wireless communication may be provided. 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, wherein the instructions, when executed by the at least one processor, cause the second device to: receive, from a first device, control information for scheduling a physical shared channel on a physical control channel; and receive, from the first device, data on the physical shared channel. For example, information related to a maximum count for listen before talk (LBT) failure detection may be acquired by the first device. For example, based on a failure in reception of the data due to an LBT failure, a first LBT counter for the first device may be incremented by 1 for a first set of RBs on which reception failed. For example, the second LBT counter for the first device may be incremented by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that no guard band is set between the RB sets.

[0012] In one embodiment, a processing device configured to control a second device may be provided. The processing device may include 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 second device to: receive, from a first device, control information for scheduling a physical shared channel on a physical control channel; and receive, from the first device, data on the physical shared channel. For example, information related to a maximum count for listen before talk (LBT) failure detection may be acquired by the first device. For example, based on a failure in reception of the data due to an LBT failure, a first LBT counter for the first device may be incremented by 1 for a first set of RBs on which reception failed. For example, the second LBT counter for the first device may be incremented by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that no guard band is set between the RB sets.

[0013] In one embodiment, a non-transitory computer-readable storage medium having instructions recorded thereon may be provided. The instructions, when executed, may cause a second device to: receive, from a first device, control information for scheduling a physical shared channel on a physical control channel; and receive, from the first device, data on the physical shared channel. For example, information related to a maximum count for listen before talk (LBT) failure detection may be obtained by the first device. For example, based on a failure in reception of the data due to an LBT failure, a first LBT counter for the first device may be incremented by 1 for a first set of RBs on which reception failed. For example, the second LBT counter for the first device may be incremented by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that no guard band is set between the RB sets.

[0014] The present disclosure can provide a device and method for effectively providing services in a wireless communication system. For example, communication can be performed efficiently through the embodiments proposed in the present disclosure.

[0015] FIG. 1 illustrates a communication structure that can be provided in a 6G system according to one embodiment of the present disclosure.

[0016] FIG. 2 illustrates an electromagnetic spectrum according to one embodiment of the present disclosure.

[0017] 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.

[0018] 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.

[0019] FIG. 5 illustrates an example of a sensing operation according to one embodiment of the present disclosure.

[0020] FIG. 6 illustrates a slot structure of a frame according to one embodiment of the present disclosure.

[0021] FIG. 7 illustrates an example of a BWP according to one embodiment of the present disclosure.

[0022] 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.

[0023] FIG. 9 illustrates an example of a wireless communication environment according to one embodiment of the present disclosure.

[0024] FIG. 10 illustrates an interlaced RB according to one embodiment of the present disclosure.

[0025] FIG. 11 illustrates an example of a wireless communication system supporting an unlicensed band according to one embodiment of the present disclosure.

[0026] FIG. 12 illustrates a method for occupying resources within an unlicensed band, according to one embodiment of the present disclosure.

[0027] FIG. 13 illustrates a case in which multiple LBT-SBs are included within an unlicensed band, according to one embodiment of the present disclosure.

[0028] FIG. 14 illustrates a CAP operation for downlink signal transmission through an unlicensed band of a base station according to an embodiment of the present disclosure.

[0029] FIG. 15 illustrates a type 1 CAP operation of a terminal for uplink signal transmission according to an embodiment of the present disclosure.

[0030] FIG. 16 illustrates a channel connection procedure according to an embodiment of the present disclosure.

[0031] FIG. 17 illustrates a procedure for beam failure detection according to one embodiment of the present disclosure.

[0032] FIG. 18 illustrates a procedure for RLF detection according to one embodiment of the present disclosure.

[0033] FIG. 19 illustrates a procedure for RLF detection according to one embodiment of the present disclosure.

[0034] FIG. 20 illustrates a procedure for LBT detection according to one embodiment of the present disclosure.

[0035] FIG. 21 illustrates a procedure for LBT with or without a guard band according to an embodiment of the present disclosure.

[0036] FIG. 22 illustrates a method for a first device to perform wireless communication according to one embodiment of the present disclosure.

[0037] FIG. 23 illustrates a method for a second device to perform wireless communication according to one embodiment of the present disclosure.

[0038] Fig. 24 shows a communication system (1) according to one embodiment of the present disclosure.

[0039] FIG. 25 illustrates a wireless device according to one embodiment of the present disclosure.

[0040] FIG. 26 illustrates a signal processing circuit for a transmission signal according to one embodiment of the present disclosure.

[0041] FIG. 27 illustrates a wireless device according to one embodiment of the present disclosure.

[0042] FIG. 28 illustrates a mobile device according to one embodiment of the present disclosure.

[0043] FIG. 29 illustrates a vehicle or autonomous vehicle according to one embodiment of the present disclosure.

[0044] 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."

[0045] 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."

[0046] 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".

[0047] 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.”

[0048] 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."

[0049] In the following explanation, ‘when, if, in case of’ can be replaced with ‘based on’.

[0050] Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] New network characteristics in 6G may include:

[0057] - Satellite integrated network

[0058] - 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).

[0059] - Seamless integration of wireless information and energy transfer

[0060] - 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.

[0061] Some general requirements for the new network characteristics of 6G, such as the above, may be as follows:

[0062] - small cell networks

[0063] - Ultra-dense heterogeneous network

[0064] - High-capacity backhaul

[0065] - 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.

[0066] - Softwarization and virtualization

[0067] Below, the core implementation technologies of the 6G system are described.

[0068] - 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 crucial 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.

[0069] - 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.

[0070] - Large-scale MIMO technology

[0071] - Hologram beamforming (HBF)

[0072] - Optical wireless technology

[0073] - Free-space optical transmission backhaul network (FSO backhaul network)

[0074] - Quantum communication

[0075] - Cell-free communication

[0076] - Integration of wireless information and power transmission

[0077] - Integration of wireless communication and sensing

[0078] - Integrated access and backhaul network

[0079] - Big data analysis

[0080] - Reconfigurable intelligent surface

[0081] - metaverse

[0082] - Blockchain

[0083] 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.

[0084] - 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.

[0085] - 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.

[0086] - 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.

[0087] - 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).

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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).

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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).

[0100] 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).

[0101] 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).

[0102] Table 2 below illustrates the number of symbols per slot (Nslotsymb), the number of slots per frame (Nframe,uslot), and the number of slots per subframe (Nsubframe,uslot) depending on the SCS setting (u) when normal CP or extended CP is used.

[0103] 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

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] The BWP can be set by Point A, an offset from Point A (NstartBWP), and a bandwidth (NsizeBWP). For example, Point A can be an outer reference point of a PRB of a carrier where subcarrier 0 of all numerologies (e.g., all numerologies supported by the network on that carrier) are aligned. 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.

[0110] 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.

[0111] 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).

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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 within the set resource pool. For example, the terminal can select resources 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 within the resource pool can transmit a PSCCH (e.g., Sidelink Control Information (SCI) or 1st-stage SCI) to the second terminal using the resources. 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.

[0119] 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 this specification, an SCI transmitted on a PSCCH may be referred to as a 1st SCI, a 1st SCI, a 1st-stage SCI, or a 1st-stage SCI format, and an SCI transmitted on a PSSCH may be referred to as a 2nd SCI, a 2nd SCI, a 2nd-stage SCI, or a 2nd-stage SCI format.

[0120] 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.

[0121] 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.

[0122] FIG. 9 illustrates an example of a wireless communication environment according to embodiments of the present disclosure. The embodiment of FIG. 9 may be combined with various embodiments of the present disclosure.

[0123] Referring to FIG. 9, a first device (910), a second device (920), and a third device (930) are exemplified as some of the devices that utilize a wireless channel in a wireless communication system. FIG. 9 illustrates only one first device (910), one second device (920), and one third device (930), but is not limited thereto.

[0124] According to the present disclosure, the first device (910), the second device (920), and / or the third device (930) can transmit and receive wireless signals in the millimeter wave (mmWave) band. For example, to improve channel gain, the first device (910), the second device (920), and / or the third device (930) can perform beamforming. Here, the beamforming can include transmit beamforming and receive beamforming. For example, the first device (910), the second device (920), and / or the third device (930) can impart directionality to a transmit signal or a receive signal. For example, the first device (910), the second device (920), and / or the third device (930) may select serving beams (912, 913, 921, 931) through a beam search or beam management procedure. After the serving beams (912, 913, 921, 931) are selected, communication may be performed through resources that are in a quasi-co-located (QCL) relationship with the resources that transmitted the serving beams (912, 913, 921, 931).

[0125] According to the present disclosure, the first device (910), the second device (920), and / or the third device (930) may include an antenna array. Each antenna included in the antenna array may be referred to as an array element or an antenna element. The antenna array may be configured in various forms, such as a linear array or a multi-layer array. The antenna array may be referred to as a massive antenna array. For example, the antenna array may include a plurality of sub-arrays each including a plurality of antenna elements.

[0126] Meanwhile, the existing NR-U (unlicensed spectrum) supports communication between terminals and base stations in unlicensed bands. Furthermore, Rel-18 plans to support mechanisms that enable communication between sidelink terminals in unlicensed bands.

[0127] Meanwhile, a set of non-contiguous RBs (equally spaced) in frequency may be allocated to a UE. Such a set of non-contiguous RBs may be referred to as interlaced RBs. This may be useful in spectrums subject to restrictions such as occupied channel bandwidth (OCB) and power spectral density (PSD), such as shared spectrum.

[0128] FIG. 10 illustrates an interlaced RB according to an embodiment of the present disclosure. The embodiment of FIG. 10 can be combined with various embodiments of the present disclosure.

[0129] Referring to Fig. 10, multiple interlaces of RBs can be defined in the frequency domain. An interlace m∈{0, 1, ..., M-1} can be composed of (common) RBs {m, M+m, 2M+m, 3M+m, ...}, where M can represent the number of interlaced RBs given by Table 3.

[0130] uM01015

[0131] A communication device (e.g., a device, UE, vehicle, drone, etc. as proposed through various embodiments of the present disclosure) may transmit a signal / channel using one or more interlaced RBs.

[0132] In this disclosure, a channel may refer to a set of frequency-domain resources that performs Listen-Before-Talk (LBT). In NR-U, a channel may refer to a 20 MHz LBT bandwidth and may have the same meaning as an RB set. For example, an RB set may be defined in Section 7 of 3GPP TS 38.214 V17.0.0.

[0133] In the present disclosure, CO (channel occupancy) may mean time / frequency axis resources acquired by a base station or terminal after successful LBT.

[0134] In this disclosure, channel occupancy time (COT) may refer to a time-domain resource acquired by a base station or terminal after successful LBT. It may be shared between the base station (or terminal) that acquired the CO and the terminal (or base station), and this may be referred to as COT sharing. Depending on the initiating device, this may be referred to as gNB-initiated COT or UE-initiated COT.

[0135] Below, a wireless communication system supporting unlicensed bands (shared spectrum) is described.

[0136] FIG. 11 illustrates an example of a wireless communication system supporting an unlicensed band, according to an embodiment of the present disclosure. For example, FIG. 11 may include an unlicensed spectrum (NR-U) wireless communication system. The embodiment of FIG. 11 may be combined with various embodiments of the present disclosure.

[0137] 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.

[0138] As shown in (a) of Fig. 11, 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. 11, the terminal and the base station may transmit and receive signals through one UCC or multiple carrier-aggregated UCCs. In other words, the terminal and the 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.

[0139] In the embodiment of FIG. 11, 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.

[0140] Unless otherwise stated, the definitions below apply to terms used in this specification.

[0141] - 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.

[0142] - Channel Access Procedure (CAP): This refers to the procedure for evaluating channel availability based on sensing to determine whether other communication node(s) are using the channel before signal transmission. The basic unit for sensing is a sensing slot with a duration of Tsl=9us. If the base station or terminal senses the channel during the sensing slot period, and the detected power for at least 4us within the sensing slot period is less than the energy detection threshold XThresh, the sensing slot period Tsl is considered to be idle. Otherwise, the sensing slot period Tsl=9us is considered to be busy. CAP may be referred to as LBT (Listen-Before-Talk).

[0143] - Channel occupancy: refers to the corresponding transmission(s) on the channel(s) by the base station / terminal after performing the channel access procedure.

[0144] - 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).

[0145] - 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.

[0146] - 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.

[0147] - 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.

[0148] FIG. 12 illustrates a method for occupying resources within an unlicensed band, according to one embodiment of the present disclosure. The embodiment of FIG. 12 may be combined with various embodiments of the present disclosure.

[0149] Referring to FIG. 12, 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 a clear channel assessment (CCA) has been confirmed. If there is a CCA threshold (e.g., XThresh) that is predefined or set by a higher layer (e.g., RRC), the communication node may determine the channel state as busy if energy higher than the CCA threshold is detected in the channel, and otherwise determine the channel state as idle. If the channel condition is determined to be idle, the communicating node can initiate signal transmission in the unlicensed band. CAP can be replaced with LBT.

[0150] Table 4 illustrates the channel access procedures (CAPs) supported in NR-U.

[0151] TypeExplanationDLType 1 CAPCAP with random back-off- time duration spanned by the sensing slots that are sensed to be idle before a downlink transmission(s) is randomType 2 CAP- Type 2A, 2B, 2CCAP without random back-off- time duration spanned by sensing slots that are sensed to be idle before a downlink transmission(s) is deterministicUL or SLType 1 CAPCAP with random back-off- time duration spanned by the sensing slots that are sensed to be idle before an uplink or sidelink transmission(s) is randomType 2 CAP- Type 2A, 2B, 2CCAP without random back-off- time duration spanned by sensing slots that are sensed to be idle before an uplink or sidelink transmission(s) is deterministic

[0152] Referring to Table 4, LBT types or CAPs for DL / UL / SL transmissions can be defined. However, Table 4 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.

[0153] Below, LBT-SB (SubBand) (or RB set) is described.

[0154] 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.

[0155] FIG. 13 illustrates a case in which multiple LBT-SBs are included within an unlicensed band, according to an embodiment of the present disclosure. The embodiment of FIG. 13 may be combined with various embodiments of the present disclosure.

[0156] Referring to FIG. 13, a BWP of a cell (or carrier) may include multiple LBT-SBs. An LBT-SB may have, for example, a 20 MHz 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 illustrated, 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.

[0157] Below, CAPC (channel access priority class) is explained.

[0158] The MAC CEs and CAPCs of the radio bearers are fixed or configurable to operate in FR1:

[0159] - Fixed to lowest priority for padding BSR (buffer status report) and recommended bit rate MAC CE;

[0160] - Fixed to highest priority for SRB0, SRB1, SRB3 and other MAC CEs;

[0161] - Configured by the base station for SRB2 and DRB.

[0162] 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 5 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 matches the QoS characteristics should be used.

[0163] 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

[0164] 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.

[0165] A base station may perform one of the following channel access procedures (CAP) for downlink signal transmission in an unlicensed band.

[0166] (1) Type 1 downlink (DL) CAP method

[0167] 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:

[0168] - (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

[0169] - 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.

[0170] FIG. 14 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. 14 may be combined with various embodiments of the present disclosure.

[0171] Referring to Figure 14, the base station first senses whether the channel is idle during the sensing slot period of the defer duration Td, and then, when 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:

[0172] Step 1) (S120) Set N=Ninit, where Ninit is a random value uniformly distributed between 0 and CWp. Then, proceed to Step 4.

[0173] Step 2) (S140) If N>0 and the base station chooses to decrement the counter, set N=N-1.

[0174] 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.

[0175] Step 4) (S130) If N=0 (Y), terminate the CAP procedure (S132). Otherwise (N), proceed to Step 2.

[0176] Step 5) (S160) Sensing the channel until a busy sensing slot is detected within the additional delay period Td or all sensing slots within the additional delay period Td are detected as idle.

[0177] Step 6) (S170) If the channel is sensed as idle during all sensing slot periods of the additional delay period Td (Y), go to Step 4. Otherwise (N), go to Step 5.

[0178] Table 6 illustrates how the mp, minimum contention window (CW), maximum CW, maximum channel occupancy time (MCOT), and allowed CW sizes applied to CAP vary depending on the channel access priority class.

[0179] Channel Access Priority Class (p)m p CW min,p CW max,p T mcot,p allowed CW p sizes11372 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}

[0180] Referring to Table 6, the contention window size (CWS) and maximum COT value for each CAPC can be defined. For example, Td = Tf + mp * Tsl.

[0181] The delay interval Td is composed of an interval Tf (16us) + mp consecutive sensing slot intervals Tsl (9us), in that order. Tf includes the sensing slot interval Tsl at the start of the 16us interval.

[0182] CWmin,p <= CWp <= CWmax,p. CWp is set as CWp = CWmin,p and can be updated (CW size update) before step 1 based on the HARQ-ACK feedback (e.g., ACK or NACK rate) for the previous DL burst (e.g., PDSCH). For example, CWp can be initialized to CWmin,p, increased to the next highest allowed value, or kept at the current value, based on the HARQ-ACK feedback for the previous DL burst.

[0183] (2) Type 2 downlink (DL) CAP method

[0184] 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.

[0185] Type 2A DL CAP can be applied to the transmissions below. In Type 2A DL CAP, the base station can transmit immediately after the channel is sensed as idle for at least a sensing period Tshort_dl = 25us. Here, Tshort_dl consists of a period Tf (= 16us) and one sensing slot period immediately following it. Tf includes a sensing slot at the beginning of the period.

[0186] - 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,

[0187] - Transmission(s) by the base station after a 25us gap from the transmission(s) by the terminal within the shared channel occupancy.

[0188] Type 2B DL ​​CAP is applicable to transmission(s) performed by the base station after a 16us gap from transmission(s) by the terminal within the shared channel occupancy time. In Type 2B DL ​​CAP, the base station can transmit transmission immediately after the channel is sensed as idle for Tf=16us. Tf includes the 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 maximum 16us gap 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 the transmission.

[0189] 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.

[0190] 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.

[0191] (1) Type 1 uplink (UL) CAP method

[0192] 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:

[0193] - Scheduled and / or configured PUSCH / SRS transmission(s) from the base station

[0194] - PUCCH transmission(s) scheduled and / or configured from the base station;

[0195] - Transmission(s) related to RAP (Random Access Procedure)

[0196] FIG. 15 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. 15 may be combined with various embodiments of the present disclosure.

[0197] Referring to Figure 15, the terminal first senses whether the channel is idle during the sensing slot period of the defer duration Td, and then, when 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:

[0198] Step 1) (S220) Set N=Ninit, where Ninit is a random value uniformly distributed between 0 and CWp. Then, proceed to Step 4.

[0199] Step 2) (S240) If N>0 and the terminal chooses to decrement the counter, set N=N-1.

[0200] 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.

[0201] Step 4) (S230) If N=0 (Y), terminate the CAP procedure (S232). Otherwise (N), proceed to Step 2.

[0202] Step 5) (S260) Sensing the channel until a busy sensing slot is detected within the additional delay period Td or all sensing slots within the additional delay period Td are detected as idle.

[0203] Step 6) (S270) If the channel is sensed as idle during all sensing slot periods of the additional delay period Td (Y), go to Step 4. Otherwise (N), go to Step 5.

[0204] Table 7 illustrates how the mp, minimum CW, maximum CW, maximum channel occupancy time (MCOT), and allowed CW sizes applied to a CAP vary depending on the channel access priority class.

[0205] Channel Access Priority Class (p)m p CW min,p CW max,p T ulmcot,p allowed CW p sizes12372 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}

[0206] Referring to Table 7, the contention window size (CWS) and maximum COT value for each CAPC can be defined. For example, Td = Tf + mp * Tsl.

[0207] The delay interval Td is composed of an interval Tf (16us) + mp consecutive sensing slot intervals Tsl (9us), in that order. Tf includes the sensing slot interval Tsl at the start of the 16us interval.

[0208] CWmin,p <= CWp <= CWmax,p. CWp is set as CWp = CWmin,p and can be updated (CW size update) before Step 1 based on the explicit / implicit reception acknowledgment for the previous UL burst (e.g., PUSCH). For example, CWp can be initialized to CWmin,p, increased to the next highest allowed value, or kept at the existing value, based on the explicit / implicit reception acknowledgment for the previous UL burst.

[0209] (2) Type 2 uplink (UL) CAP method

[0210] In a Type 2 UL CAP, the length of the time interval spanned by the sensing slots during which the channel is sensed as idle before a transmission(s) is deterministic. Type 2 UL CAP is divided into Type 2A / 2B / 2C UL CAP. In a Type 2A UL CAP, a UE can transmit a transmission immediately after the channel has been sensed as idle for at least a sensing interval Tshort_dl=25us. Here, Tshort_dl consists of an interval Tf(=16us) and one sensing slot interval immediately following it. In a Type 2A UL CAP, Tf includes a sensing slot at the beginning of the interval. In a Type 2B UL CAP, a UE can transmit a transmission immediately after the channel has been sensed as idle for a sensing interval Tf=16us. In a Type 2B UL CAP, Tf includes 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.

[0211] For example, according to the 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 perform the NR-U operation by applying the parameters of the corresponding CACP (e.g., minimum contention window size, maximum contention window size, mp, etc.). For example, the terminal can select a random value between the minimum CW and the maximum CW mapped to the CAPC, and then select a BC (Backoff Counter) between 0 and the random value. In this case, for example, the BC can be a positive integer less than or equal to the random value. The terminal sensing the channel decrements the BC by 1 when the channel is idle. When the BC becomes zero and the terminal detects that the channel is idle for a time Td (Td = Tf + mp * Tsl), the terminal can occupy the channel and attempt to transmit data. If a terminal attempting data transmission detects a collision, it can increase the CW size mapped to the CAPC, and reselect a BC between zero and the increased CW. A terminal that successfully transmits a packet can reset the CW size (to CW min).

[0212] For example, Tsl (= 9 usec) is a basic sensing unit or sensing slot and can include a measurement duration of at least 4 usec. For example, the first 9 usec of Tf (= 16 usec) can be configured as Tsl. For example, mp can be a constant mapped by CAPC and can be used in calculating Td. For example, a smaller value can be mapped as the CACP value decreases (the priority increases).

[0213] 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.

[0214] 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.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] FIG. 16 illustrates a channel access procedure according to an embodiment of the present disclosure. Specifically, FIG. 16 (a) illustrates an example of a dynamic channel access procedure (load-based equipment, LBE), and FIG. 16 (b) illustrates an example of a semi-static channel access procedure (frame-based equipment, FBE). The embodiment of FIG. 16 can be combined with various embodiments of the present disclosure.

[0219] Referring to Figure 16 (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.

[0220] Referring to (b) of FIG. 16, 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. The terminal can perform a Type 2 series LBT operation within the FFP. For example, within the FFP, the terminal may not perform random backoff-based LBT, and the terminal may sense the channel for a certain short time and perform data transmission when the channel is idle.

[0221] Meanwhile, in the conventional NR Uu (operation between a base station and a UE), a new beam management operation has been introduced at mmWave frequencies. For example, the beam management operation may be beam scheduling, beam selection, beam failure recovery, etc. In the present disclosure, the beam management (e.g., beam failure recovery) operation is proposed as follows. For example, the following proposal may be an operation related to beam management in NR. Meanwhile, the following proposal is not limited to NR. For example, the following proposal may be an operation related to beam management in sidelink. Meanwhile, the following proposal is not limited to sidelink. For example, the following proposal may be an operation related to beam management in NR sidelink.

[0222] The terminal can perform the following motion-based FR2 (mmWave frequency-based communication) operations. For example, FR2 may be sidelink FR2. For example, sidelink FR2 may be sidelink mmWave frequency-based communication. Meanwhile, the motion-based operations below are not limited to sidelink FR2. The present disclosure is not limited to sidelink FR2. For example, the present disclosure can be applied to 5G FR2 or FR2 beyond 5G (e.g., 6G FR2).

[0223] - Beam sweeping operation: The terminal may perform an operation of sweeping the beams to be used for communication to find the best beam (e.g., a transmission beam, a reception beam). For example, the terminal may perform an operation of covering a spatial area using the transmission and / or reception beams for a predetermined time interval in a predetermined manner. For example, communication in the beam sweeping operation may be sidelink communication.

[0224] - Beam measurement operation: The terminal can perform an operation of measuring a reference signal (RS) transmitted by a counterpart terminal and finding an RS whose measurement value is greater than a threshold.

[0225] - Beam selection operation: The terminal can perform an operation of selecting the best beam (e.g., transmission beam, reception beam) based on the beam measurement result.

[0226] - Beam reporting operation: The terminal can perform an operation of reporting the selected best beam to the opposing terminal or base station.

[0227] - Beam pairing operation: Terminals can perform an operation to synchronize (pair) beams (e.g., transmission beam / reception beam) with each other to enable communication through beams (e.g., transmission beam / reception beam) between terminals.

[0228] (Sidelink) (In FR2) For beam management (e.g., beam sweeping, beam measurement, beam selection, beam pairing) of terminals, terminals can transmit and receive reference signals (RS) to select / decide and adjust / manage BEAMs that can be used between each other.

[0229] FIG. 17 illustrates a procedure for beam failure detection 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, if a terminal detects a threshold amount of failures in a beam being used for communication, the terminal may trigger a beam failure recovery procedure to perform a beam recovery procedure. For example, if a terminal detects a threshold amount of failures in a beam being used for sidelink communication, the terminal may trigger a sidelink beam failure recovery procedure to perform a beam recovery procedure. For example, if the MAC layer of the terminal receives a threshold amount of beam failure instances from the physical layer, the terminal may trigger a beam failure recovery procedure to perform a beam recovery procedure. For example, the beam recovery procedure by triggering a beam failure recovery procedure may be performed by the MAC layer of the terminal. For example, if the MAC layer of a terminal receives a threshold number of beam failure instances from the physical layer, the terminal may trigger a sidelink beam failure recovery procedure to perform a beam recovery procedure. For example, the beam recovery procedure by triggering a sidelink beam failure recovery procedure may be performed by the MAC layer of the terminal. Although the present disclosure has been described with respect to sidelink beam failure, it is not limited thereto. For example, the present disclosure may be applied to beam failures other than sidelink beam failure as well as sidelink beam failure.

[0231] In Fig. 17, for example, the MAC layer may configure a beam failure recovery procedure that is used to notify when a beam failure is detected by the RRC. For example, a beam failure may be detected by counting beam failure instance indications to the MAC entity from a lower layer. For example, the RRC may configure a beam failure instance maximum count and a beam failure detection timer. For example, the beam failure instance maximum count may determine how many beam failure events must pass before the terminal triggers beam failure recovery. For example, the beam failure instance maximum count may be set to 3. For example, the beam failure detection timer may be a timer for beam failure detection. For example, if a beam failure instance indication is received from a lower layer, the beam failure detection timer may be started or restarted. For example, if a beam failure instance indication is received from a lower layer, the beam failure instance counter can be increased by 1. For example, if the beam failure instance counter is greater than or equal to a maximum count of beam failure instances, a beam failure can be detected. For example, if the beam failure instance counter is greater than or equal to 3, a beam failure can be detected. For example, if the beam failure instance counter is greater than or equal to a maximum count of beam failure instances, a beam failure recovery procedure can be triggered.For example, if the beam failure instance counter is greater than or equal to 3, a beam failure recovery procedure can be triggered. For example, if the beam failure detection timer expires, the beam failure instance counter can be set to 0.

[0232] In Fig. 17, the maximum count of beam failure instances is set to 3, but this is not limited to this. For example, the maximum count of beam failure instances may be set to a value other than 3.

[0233] In this disclosure, the following follow-up actions of the terminal are proposed when the (SL) BFR procedure fails.

[0234] When beam failure recovery (BFR) is triggered, the terminal may transmit a (SL) BFR MAC CE (e.g., for the purpose of indicating that there is a problem with the currently operating transmit beam or receive beam, or for the purpose of indicating that there is a problem with a reference signal associated with the currently operating transmit beam or receive beam, or for the purpose of indicating a best transmit beam or a best receive beam for beam failure recovery when BFR is triggered) and may also start a (SL) BFR timer to initiate the (SL) BFR process. If feedback (e.g., a (SL) BFR confirmation MAC CE or HARQ ACK feedback) for the transmitted (SL) BFR MAC CE is not received by the time the BFR timer expires, the terminal may initiate the following procedure.

[0235] - The terminal can re-trigger the BFR process by retransmitting (SL) BFR MAC CE (for example, to indicate that there is a problem with the currently operating transmit beam or receive beam, or to indicate that there is a problem with the reference signal associated with the currently operating transmit beam or receive beam, or to indicate the best transmit beam or best receive beam for beam failure recovery when BFR is triggered).

[0236] - The terminal may consider the (SL) BFR process as a failure and declare (SL) RLF for the PC5 RRC connection for which (SL) BFR was triggered and report it to the base station or the other terminal (with cause: (SL) beam failure recovery (BFR) fail-based (sidelink) RLF).

[0237] - The terminal can re-trigger or re-perform at least one operation among beam sweeping, beam selection, or beam pairing.

[0238] For example, if a terminal detects a threshold amount of failure in a beam being used for (sidelink) communication, the terminal can trigger a (sidelink) beam failure recovery procedure to perform a procedure for recovering the beam. In the present disclosure, when a threshold amount of (sidelink) beam failure occurs, the BFR operation of the terminal can be defined as follows:

[0239] In this disclosure, the following follow-up actions of the terminal are proposed when the (SL) BFR procedure fails.

[0240] When beam failure recovery (BFR) is triggered, the terminal may transmit a (SL) BFR MAC CE (e.g., for the purpose of indicating that there is a problem with the currently operating transmit beam or receive beam, or for the purpose of indicating that there is a problem with a reference signal associated with the currently operating transmit beam or receive beam, or for the purpose of indicating a best transmit beam or a best receive beam for beam failure recovery when BFR is triggered) and may also start a (SL) BFR timer to initiate the (SL) BFR process. If feedback (e.g., a (SL) BFR confirmation MAC CE or HARQ ACK feedback) for the transmitted (SL) BFR MAC CE is not received by the time the BFR timer expires, the terminal may initiate the following procedure.

[0241] - The terminal can re-trigger the BFR process by retransmitting (SL) BFR MAC CE (for example, to indicate that there is a problem with the currently operating transmit beam or receive beam, or to indicate that there is a problem with the reference signal associated with the currently operating transmit beam or receive beam, or to indicate the best transmit beam or best receive beam for beam failure recovery when BFR is triggered).

[0242] - The terminal may consider the (SL) BFR process as a failure and declare (SL) RLF for the PC5 RRC connection for which (SL) BFR was triggered and report it to the base station or the other terminal (with cause: (SL) beam failure recovery (BFR) fail-based (sidelink) RLF).

[0243] - The terminal can re-trigger or re-perform at least one operation among beam sweeping, beam selection, or beam pairing.

[0244] In the present disclosure, (sidelink) DRX configuration may include at least one or more of the following parameters.

[0245] - SL drx-onDurationTimer: Duration at the start of the SL DRX cycle

[0246] - SL drx-SlotOffset: Delay before the start of SL drx-onDurationTimer

[0247] - SL drx-InactivityTimer: Duration after a PSCCH opportunity instructing a new SL transmission to the MAC entity.

[0248] - SL drx-StartOffset: Subframe where the SL DRX cycle starts

[0249] - SL drx-Cycle: SL DRX Cycle

[0250] - SL drx-HARQ-RTT-Timer (per HARQ process or per sidelink process): Minimum duration before allocation for HARQ retransmission expected by the MAC entity.

[0251] - SL drx-RetransmissionTimer (per HARQ process or per sidelink process): Maximum duration until a retransmission is received.

[0252] In this disclosure, the (sidelink) DRX timer below can be used for the following purposes.

[0253] - (Sidelink) DRX Onduration Timer: (Sidelink) The period during which a UE performing DRX operation must basically operate as an active time to receive PSCCH / PSSCH from the other UE.

[0254] - (Sidelink) DRX Inactivity Timer: A period for extending the (sidelink) DRX Onduration period, which is a period during which a UE performing (sidelink) DRX operation must basically operate as an active time in order to receive PSCCH / PSSCH of the counterpart UE. For example, the (sidelink) DRX Onduration timer can be extended by the period of the (sidelink) DRX Inactivity timer. For example, when the UE receives a PSCCH (1st SCI and 2nd SCI) for a new TB from the counterpart UE or a new packet (new PSSCH transmission), the UE can start the (sidelink) DRX Inactivity timer and extend the (sidelink) DRX Onduration timer.

[0255] - (Sidelink) DRX HARQ RTT Timer: A period during which a UE performing (sidelink) DRX operation operates in sleep mode until it receives a retransmission packet (e.g., or PSSCH allocation) transmitted by a counterpart UE. For example, if a UE starts a (sidelink) DRX HARQ RTT timer, the UE may determine that the counterpart UE will not transmit a (sidelink) retransmission packet to it until the (sidelink) DRX HARQ RTT timer expires, and may operate in sleep mode during the timer (or may not monitor the (sidelink) channel / signal transmitted by the Tx UE).

[0256] - (Sidelink) DRX Retransmission Timer: A period during which a UE performing (sidelink) DRX operation operates as an active time to receive a retransmission packet (e.g., or PSSCH allocation) transmitted by a counterpart UE. During this timer period, the UE can monitor the reception of a retransmission (sidelink) packet (e.g., or PSSCH allocation) transmitted by the counterpart UE.

[0257] For example, the names of the timers (e.g., (Sidelink) DRX Onduration Timer, (Sidelink) DRX Inactivity Timer, (Sidelink) DRX HARQ RTT Timer, (Sidelink) DRX Retransmission Timer, etc.) are examples, and timers that perform the same / similar function based on the description of each timer can be considered the same / similar timer regardless of the name.

[0258] For example, PSFCH reception may be performed. For example, the MAC entity may perform a HARQ-based (sidelink) RLF detection procedure for each PSSCH transmission. For example, the MAC entity may perform a HARQ-based (sidelink) RLF detection procedure for each PSSCH transmission if the PSSCH transmission occurs for a pair of source Layer-2 IDs and destination Layer-2 IDs corresponding to a PC5-RRC connection established by a higher layer.

[0259] FIG. 18 illustrates a procedure for RLF detection according to an embodiment of the present disclosure. The embodiment of FIG. 18 can be combined with various embodiments of the present disclosure.

[0260] Referring to FIG. 18, for example, HARQ-based (sidelink) RLF (radio link failure) detection can be performed.

[0261] For example, if a transmitting terminal does not receive a physical feedback channel (e.g., PSFCH) (e.g., HARQ ACK or HARQ NACK) from a receiving terminal after transmitting a physical control channel / physical shared channel (e.g., PSCCH / PSSCH), the transmitting terminal may increase a discontinuous transmission (DTX) count by 1 and declare a (SL) RLF when the DTX count reaches a threshold. For example, when declaring an (SL) RLF for a unicast link, the terminal may release the PC5 RRC connection that declared the (SL) RLF and report (e.g., report) a PC5 link identifier associated with the released PC5 RRC connection to a higher layer (e.g., a V2X layer). For example, the terminal may report (e.g., report) to the base station that an (SL) RLF has occurred. For example, when reporting, the terminal may report (e.g., report) together the unicast link information where the RLF occurred (e.g., destination layer 2 ID) and the cause (cause) of the (SL) RLF occurrence (e.g., (SL) RLF).

[0262] For example, a HARQ-based (sidelink) RLF detection procedure can be used to detect (sidelink) RLF based on the number of consecutive discontinuous transmissions (DTXs) ​​in a PSFCH reception occasion for a PC5-RRC connection.

[0263] For example, RRC can set the following parameters to control HARQ-based (sidelink) RLF detection. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) can be set. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) can indicate the maximum number of DTX (e.g., consecutive HARQ DTX) before triggering an RLF.

[0264] For example, the following UE variables can be used for HARQ-based (sidelink) RLF detection: For example, the DTX maintained for each PC5-RRC connection (e.g., numConsecutiveDTX) can be set.

[0265] For example, the (sidelink) HARQ entity may (re)initialize the DTX (e.g., numConsecutiveDTX) to 0 when establishing the PC5-RRC connection or (re)establishing the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX), if any, for each PC5-RRC connection established from the upper layer. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) may be set to 3. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) may not be limited to 3. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) may be (re)configured to a value different from 3.

[0266] For example, the (sidelink) HARQ entity may increment the DTX (e.g., numConsecutiveDTX) by 1 for each PSFCH reception opportunity associated with a PSSCH transmission. For example, the (sidelink) HARQ entity may increment the DTX (e.g., numConsecutiveDTX) by 1 for each PSFCH reception opportunity associated with a PSSCH transmission if there is no PSFCH reception in the PSFCH reception opportunity.

[0267] For example, the (sidelink) HARQ entity may instruct RRC to perform HARQ-based (sidelink) RLF detection for each PSFCH reception opportunity associated with a PSSCH transmission. For example, the (sidelink) HARQ entity may instruct RRC to perform HARQ-based (sidelink) RLF detection for each PSFCH reception opportunity associated with a PSSCH transmission if the DTX (e.g., numConsecutiveDTX) reaches the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX). For example, the (sidelink) HARQ entity may, for each PSFCH reception opportunity associated with a PSSCH transmission, increase the DTX (e.g., numConsecutiveDTX) by 1 if there is no PSFCH reception in the PSFCH reception opportunity, and may instruct RRC to perform HARQ-based (sidelink) RLF detection if the DTX (e.g., numConsecutiveDTX) reaches a maximum DTX (e.g., (sl-)maxNumConsecutiveDTX). For example, as illustrated in FIG. 18, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) may be set to 3. For example, as illustrated in FIG. 18, the (sidelink) HARQ entity may instruct RRC to perform HARQ-based (sidelink) RLF detection for each PSFCH reception opportunity associated with a PSSCH transmission, if the DTX (e.g., numConsecutiveDTX) reaches a maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) of 3. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) may not be limited to 3. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) may be (re)configured to a value different from 3.

[0268] For example, the (sidelink) HARQ entity may reinitialize DTX (e.g., numConsecutiveDTX) to 0 for each PSFCH reception opportunity associated with a PSSCH transmission. For example, the (sidelink) HARQ entity may reinitialize DTX (e.g., numConsecutiveDTX) to 0 for each PSFCH reception opportunity associated with a PSSCH transmission, unless there is no PSFCH reception in the PSFCH reception opportunity (e.g., if else for “if there is no PSFCH reception in the PSFCH reception opportunity”).

[0269] In FIG. 18, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) is shown to be set to 3, but is not limited thereto. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) may be (re)set to a value other than 3.

[0270] In multi-carrier operation or carrier aggregation (CA), there may be multiple carriers involved in a PC5-RRC connection. There may be issues with detecting RLF and indicating RLF detection to upper layers when detecting DTX peaks on only some carriers.

[0271] FIG. 19 illustrates a procedure for RLF detection according to an embodiment of the present disclosure. The embodiment of FIG. 19 can be combined with various embodiments of the present disclosure.

[0272] Referring to FIG. 19, for example, HARQ-based (sidelink) RLF (radio link failure) detection can be performed.

[0273] For example, in LTE V2X, a terminal supporting multi-channel operation (e.g., multi-carrier operation or carrier aggregation) can select a specific carrier for transmitting (sidelink) data, select available resources on the selected carrier, and transmit (sidelink) data through the selected resources and carrier.

[0274] In the present disclosure, the PC5 RRC connection establishment operation of a multi-carrier operation supporting terminal can be proposed as follows.

[0275] In (sidelink) multicarrier operation, PC5 RRC connections can be established or configured on a (sidelink) carrier-by-carrier basis (e.g., or per (sidelink) HARQ entity mapped to a (sidelink) carrier). For example, (sidelink) data transmission (e.g., SL-SCH transmission) is managed by the (sidelink) HARQ entity (e.g., flushing the HARQ buffer or flushing the soft buffer of the (sidelink) process, (sidelink) process management, (sidelink) transport block allocation to an unoccupied sidelink process, etc.), and also, in (sidelink) multi-carrier operation, there is one (sidelink) HARQ entity per carrier, and the (sidelink) HARQ entity mapped to the (sidelink) carrier can manage (sidelink) data transmission per carrier (e.g., flushing the HARQ buffer or flushing the soft buffer of the (sidelink) process, (sidelink) process management, (sidelink) transport block allocation to an unoccupied sidelink process, etc.). For example, it may be desirable for PC5 RRC connections to be managed on a per (sidelink) carrier basis (e.g., or per (sidelink) HARQ entity mapped to a (sidelink) carrier).

[0276] When a (sidelink) terminal and a counterpart (sidelink) terminal establish a PC5 unicast link (e.g., or a PC5-S connection) between each other, a PC5 RRC connection can be established for each (sidelink) carrier that has been set up for (sidelink) communication or is being used for (sidelink) communication. The terminal that has established a PC5 unicast link (or PC5-S connection) can proceed with the (sidelink) capability negotiation process by exchanging PC5 RRC messages for each (sidelink) carrier. For example, terminals that have established a PC5 unicast link (e.g., or a PC5-S connection) can perform a PC5 RRC reconfiguration process for each (sidelink) carrier by exchanging PC5 RRC messages (e.g., RRC (sidelink) reconfiguration (e.g., RRCreconfigurationSidelink) message, RRCreconfigurationCompleteSidelink message) to configure a (sidelink) radio bearer (e.g., SL DRB configuration) between them. The (sidelink) radio bearer information may include allowed (sidelink) carrier index information mapped to the corresponding radio bearer. A (sidelink) radio bearer configured per (sidelink) carrier (e.g., a (sidelink) radio bearer configured through PC5 RRC reconfiguration of a specific (sidelink) carrier-specific PC5 RRC connection) can only be used for (sidelink) communication through the corresponding (sidelink) carrier (e.g., a carrier on which PC5 RRC reconfiguration was performed or an allowed (sidelink) carrier included in (sidelink) radio bearer information configured during the PC5 RRC reconfiguration process).

[0277] For example, the terminal can declare SL RLF for each PC5 RRC connection established for each (sidelink) carrier (e.g., SL RLF can be declared when DTX is detected at or above a preset threshold in the corresponding (sidelink) carrier. For example, SL RLF can be declared when HARQ NACK Feedback is received at or above a preset threshold in response to PSCCH / PSSCH transmission in the corresponding (sidelink) carrier.). When SL RLF is declared on a specific (sidelink) carrier, the UE may terminate the PC5 RRC connection of the carrier and report the PC5 link identifier associated with the terminated PC5 RRC connection, the (sidelink) carrier index information associated with the terminated PC5 RRC connection, and the SL RLF cause and Source Layer-2 ID / Destination Layer-2 ID to the upper layer (e.g., V2X layer) and the base station.

[0278] For example, the UE may declare a PC5 RRC reconfiguration failure per PC5 RRC connection established per (sidelink) carrier (e.g., the UE declares a PC5 RRC reconfiguration failure if it transmits an RRC (sidelink) reconfiguration (e.g., RRCreconfigurationSidelink) message on the corresponding (sidelink) carrier and does not receive an RRC (sidelink) reconfiguration complete (e.g., RRCreconfigurationCompleteSidelink) message or an RRC (sidelink) reconfiguration failure (e.g., RRCreconfigurationFailureSidelink) message until the T400 timer expires). When a PC5 RRC reconfiguration failure is declared on a specific (sidelink) carrier (e.g., considering that SL RLF has occurred on that (sidelink) carrier), the UE may terminate the PC5 RRC connection on that carrier and report the PC5 link identifier associated with the terminated PC5 RRC connection, the (sidelink) carrier index information associated with the terminated PC5 RRC connection, the cause of the PC5 RRC reconfiguration failure, and the Source Layer-2 ID / Destination Layer-2 ID to the upper layer (e.g., V2X layer) and the base station.

[0279] In the present disclosure, the SL RLF operation of a multi-carrier operation supporting terminal can be proposed as follows.

[0280] In the present disclosure, it can be proposed that the terminal manages the numConsecutiveDTX parameter for each (sidelink) carrier (e.g., or for each (sidelink) HARQ entity of each (sidelink) carrier) so that the transmitting terminal increases and manages the DTX count for each carrier when a DTX occurs. For example, even if the transmitting terminal has established a PC5 RRC connection that is commonly used for all carriers, it can be proposed that the numConsecutiveDTX count is managed for each (sidelink) carrier of the PC5 RRC connection to perform DTX counting. For example, when the numConsecutiveDTX count for each carrier reaches a preset threshold, the SL RLF can be declared for the corresponding (sidelink) carrier. When SL RLF is declared on a specific (sidelink) carrier, the UE can report the carrier index information and the SL RLF cause and the Source Layer-2 ID / Destination Layer-2 ID of the corresponding carrier to the upper layer (e.g., V2X layer) and the base station. When the UE declares SL RLF on the configured (sidelink) carrier or all (sidelink) carriers in operation or use, the UE can terminate the PC5 RRC connection and report the PC5 link identifier associated with the terminated PC5 RRC connection and all (sidelink) carrier index information and the SL RLF cause and the Source Layer-2 ID / Destination Layer-2 ID associated with the terminated PC5 RRC connection to the upper layer (e.g., V2X layer) and the base station.

[0281] As an example of the present disclosure, the following (sidelink) RLF operation of the terminal may be proposed.

[0282] For example, the behavior of a UE (e.g., a transmitting UE) may be proposed if parameters for (sidelink) RLF operation per (sidelink) carrier or (sidelink) BWP or (sidelink) HARQ entity (e.g., (sl-)MaxNumConsecutiveDTX: this field may indicate the maximum number of consecutive HARQ DTXs before triggering a (sidelink) RLF, numConsecutiveDTX parameter: when a DTX occurs, the UE may increment the numConsecutiveDTX parameter by 1 and declare SL RLF for the PC5 RRC connection associated with the (sidelink) carrier or (sidelink) BWP or (sidelink) HARQ entity) are configured (e.g., differently) or managed.

[0283] For example, a) The terminal may accumulate counts of multiple SL RLF parameters (e.g., numConsecutiveDTX) mapped to multiple (sidelink) carriers / SL BWPs / (sidelink) HARQ entities associated with a PC5 RRC connection, and when the accumulated counts reach (sl-)MaxNumConsecutiveDTX, the terminal may declare SL RLF for the PC5 RRC connection associated with multiple (sidelink) carriers / SL BWPs / (sidelink) HARQ entities and terminate the corresponding PC5 RRC connection. For example, the UE may perform numConsecutiveDTX counting for multiple carriers / BWPs / (sidelink) HARQ entities using the minimum (e.g., or maximum or (e.g., weighted) average) value of multiple SL RLF parameters (e.g., (sl-)MaxNumConsecutiveDTX), and when the DTX counting reaches the minimum (e.g., or maximum or (e.g., weighted) average) value of (sl-)MaxNumConsecutiveDTX, the UE may declare SL RLF for the PC5 RRC connection associated with the multiple (sidelink) carriers / SL BWPs / (sidelink) HARQ entities and terminate the corresponding PC5 RRC connection.

[0284] For example, the terminal may declare SL RLF for the PC5 RRC connection associated with multiple (sidelink) carriers / SL BWP / (sidelink) HARQ entities and terminate the corresponding PC5 RRC connection if the numConsecutiveDTX counting reaches (sl-)MaxNumConsecutiveDTX or reaches the minimum (e.g., or maximum or (e.g., weighted) average) value of (sl-)MaxNumConsecutiveDTX for at least one carrier / SL BWP / (sidelink) HARQ entity among multiple (sidelink) carriers / SL BWP / (sidelink) HARQ entities associated with the PC5 RRC connection.

[0285] For example, the terminal may declare SL RLF for the PC5 RRC connection associated with multiple (sidelink) carriers / SL BWP / (sidelink) HARQ entities and terminate the corresponding PC5 RRC connection when the numConsecutiveDTX counting for each of the multiple (sidelink) carriers / SL BWP / (sidelink) HARQ entities associated with the PC5 RRC connection reaches (sl-)MaxNumConsecutiveDTX or reaches the minimum (e.g., or maximum or (e.g., weighted) average) value of (sl-)MaxNumConsecutiveDTX.

[0286] For example, if the parameters for (sidelink) RLF operation per (sidelink) carrier or (sidelink) BWP or (sidelink) HARQ entity (e.g., (sl-)MaxNumConsecutiveDTX: this field can indicate the maximum number of consecutive HARQ DTXs before triggering (sidelink) RLF, numConsecutiveDTX parameter: when a DTX occurs, the UE increases the numConsecutiveDTX parameter by 1 and when numConsecutiveDTX reaches (sl-)MaxNumConsecutiveDTX, it can declare SL RLF for the PC5 RRC connection associated with the (sidelink) carrier or (sidelink) BWP or (sidelink) HARQ entity) are set to the same value or are managed identically (e.g., or a (sidelink) unicast session (e.g., or a PC5 RRC connection), the SL RLF parameters commonly applied per (sidelink) carrier or (sidelink) BWP or (sidelink) HARQ entity) (e.g., (sl-)MaxNumConsecutiveDTX: this field can indicate the maximum number of consecutive HARQ DTXs before triggering (sidelink) RLF, numConsecutiveDTX parameter: when a DTX occurs, the UE can declare SL RLF for the PC5 RRC connection associated with the (sidelink) carrier or (sidelink) BWP or (sidelink) HARQ entity) are set to the same value or are managed identically (e.g., or a (sidelink) unicast session (e.g., or a PC5 RRC connection), (sidelink) RLF can be triggered by indicating the maximum number of consecutive HARQ DTXs, numConsecutiveDTX parameter: When a DTX occurs, the UE increments the numConsecutiveDTX parameter by 1 and when numConsecutiveDTX reaches (sl-)MaxNumConsecutiveDTX, it can declare SL RLF for the PC5 RRC connection associated with the (sidelink) carrier or (sidelink) BWP or (sidelink) HARQ entity. The behavior of the UE (e.g., the transmitting UE) can be suggested when (sl-)MaxNumConsecutiveDTX is set.

[0287] For example, a) The terminal may accumulate numConsecutiveDTX counting commonly for multiple (sidelink) carriers / SL BWP / SL HARQ entities using the same (sidelink) RLF parameter, and when the numConsecutiveDTX counting reaches (sl-)MaxNumConsecutiveDTX, declare an SL RLF declaration for the PC5 RRC connection associated with multiple (sidelink) carriers / SL BWP / SL HARQ entities and terminate the corresponding PC5 RRC connection.

[0288] For example, if the numConsecutiveDTX counting of at least one of the multiple (sidelink) carriers / SL BWP / SL HARQ entities associated with the PC5 RRC connection reaches (sl-)MaxNumConsecutiveDTX, the terminal may declare an SL RLF declaration for the PC5 RRC connection associated with the multiple (sidelink) carriers / SL BWP / SL HARQ entities and terminate the corresponding PC5 RRC connection.

[0289] For example, the terminal may declare an SL RLF declaration for the PC5 RRC connection associated with multiple (sidelink) carriers / SL BWP / SL HARQ entities and terminate the corresponding PC5 RRC connection when the numConsecutiveDTX counting for each of the multiple (sidelink) carriers / SL BWP / SL HARQ entities associated with the PC5 RRC connection reaches (sl-)MaxNumConsecutiveDTX.

[0290] For example, the following (sidelink) RLF operation of the terminal may be proposed.

[0291] For example, operation 1) The terminal may perform SL DTX counting (e.g., counting of numConsecutiveDTX) operation for each (sidelink) carrier / SL BWP / (sidelink) HARQ entity by setting and / or applying SL RLF parameters (e.g., (sl-)MaxNumConsecutiveDTX, numConsecutiveDTX) for each (sidelink) carrier / SL BWP / (sidelink) HARQ entity.

[0292] For example, operation 2) SL RLF parameters (e.g., (sl-)MaxNumConsecutiveDTX, numConsecutiveDTX) are set and / or applied per (sidelink) carrier / SL BWP / (sidelink) HARQ entity, but (sidelink) DTX counting (e.g., counting of numConsecutiveDTX) can be cumulatively counted together across multiple (e.g., or pre-configured) (sidelink) carriers / SL BWP / (sidelink) HARQ entities.

[0293] For example, operation 3) SL RLF parameters may be commonly applied and / or configured for multiple (e.g., or pre-configured) (sidelink) carriers / SL BWP / (sidelink) HARQ entities and SL DTX counting (e.g., counting of numConsecutiveDTX) may be commonly counted for multiple (e.g., or pre-configured) (sidelink) carriers / SL BWP / (sidelink) HARQ entities.

[0294] In the present disclosure, the following conditions may be proposed as conditions for a terminal to declare (side link) RLF in relation to operations 1), 2) and 3).

[0295] For example, the conditions for declaring a (sidelink) RLF could be:

[0296] 1) When the counted number of (sidelink) DTXs (e.g., numConsecutiveDTX) per pre-configured (sidelink) carrier / SL BWP / SL HARQ entity (e.g., associated with a PC5 RRC connection) reaches the associated (sl-)MaxNumConsecutiveDTX threshold (e.g., action 1).

[0297] 2) When the (sidelink) DTX counting (e.g., numConsecutiveDTX) value of each of all (sidelink) carriers / SL BWP / SL HARQ entities (e.g., associated with a PC5 RRC connection) reaches the associated (sl-)MaxNumConsecutiveDTX threshold (e.g., or when the (sidelink) DTX counting value of each of all (sidelink) carriers / SL BWP / SL HARQ entities, cumulatively counted together, reaches the (sl-)MaxNumConsecutiveDTX threshold) (e.g., Action 1, Action 2)

[0298] 3) When the (sidelink) DTX counting value for a pre-configured number (e.g., “1”) of (sidelink) carriers / SL BWP / SL HARQ entities among the multiple (sidelink) carriers / SL BWP / SL HARQ entities (e.g., associated with a PC5 RRC connection) reaches the associated (sl-)MaxNumConsecutiveDTX threshold (e.g., or when the numConsecutiveDTX counting value for a pre-configured number (e.g., “1”) of (sidelink) carriers / SL BWP / SL HARQ entities among the multiple (sidelink) carriers / SL BWP / SL HARQ entities reaches the associated (sl-)MaxNumConsecutiveDTX threshold) (e.g., action 1, action 2, action 3)

[0299] For Action 2) and Action 3), the (sidelink) RLF assertion may be limited to the occurrence of this event (e.g., the numConsecutiveDTX counting value reaches the associated (sl-)MaxNumConsecutiveDTX threshold) within a pre-configured timer, which may be started when DTX counting is performed in one (sidelink) carrier / SL BWP / SL HARQ entity or when a (sidelink) RLF is asserted.

[0300] 4) The terminal may apply or perform DTX counting (e.g., numConsecutiveDTX) together for (e.g., one or more) (sidelink) carriers / SL BWP / SL HARQ entities related to the same unicast service or Destination Layer-2 ID. For example, if unicast sessions A and B of the terminal are the same unicast service, when DTX occurs in unicast session A, the terminal may increase the DTX counting by 1 not only in unicast session A (e.g., or PC5 RRC connection) but also in unicast session B (e.g., or PC5 RRC connection). For example, if unicast sessions A and B of the terminal are the same unicast service, when SL RLF is declared in unicast session A, the terminal may declare SL RLF in unicast session B (e.g., or PC5 RRC connection) in the same manner.

[0301] For example, if the SL DTX counting (e.g., numConsecutiveDTX) value for a specific unicast service or destination layer-2 ID reaches a preset threshold number of times for a (sidelink) carrier / SL BWP / SL HARQ entity (e.g., in a situation where multiple service or destination layer-2 IDs are in operation for a unicast session), an SL RLF can be declared for the related unicast session (e.g., or the related PC5 RRC connection).

[0302] In an embodiment of the present disclosure, a terminal may select a carrier set (e.g., a concerned carrier set) to use for multi-carrier operation for DTX-based RLF declaration, and may declare SL RLF and terminate all unicast sessions (e.g., or all PC5 RRC connections) of the terminal when the SL DTX counting (e.g., numConsecutiveDTX) value reaches a preset threshold number of times in all carriers of the carrier set, as in the proposed embodiment.

[0303] For example, a terminal may select a set of carriers (e.g., a set of concerned carriers) to use for multi-carrier operation for DTX-based RLF declaration as follows:

[0304] For example, 1) A set of all carriers with PSFCH configured among the carriers negotiated to be used for CA between UEs through PC5-RRC (e.g., capability negotiation)

[0305] When establishing a unicast connection with a counterpart terminal (e.g., during capability negotiation or PC5 RRC reconfiguration), the terminal can negotiate a carrier set for multicarrier (e.g., or carrier aggregation). The terminal can select a carrier set that includes only carriers with PSFCH configured (e.g., or carriers including a resource pool with PSFCH configured) among the negotiated carriers as the carrier set used for multicarrier operation for DTX-based RLF declaration.

[0306] For example, 2) A set of all carriers with PSFCH configured among the carriers configured for QoS flows of a pair of SRC / DST from the V2X layer.

[0307] The AS layer of a terminal (e.g., the MAC layer of the terminal) can receive a set of carriers for multicarriers (e.g., or carrier aggregation) mapped to a service (e.g., a pair of Source Layer-2 ID / Destination Layer-2 IDs or a service associated with a pair of Source Layer-2 ID / Destination Layer-2 IDs or a QoS flow(s) associated with a pair of Source Layer-2 ID / Destination Layer-2 IDs) from a higher layer (e.g., a V2X layer). The AS layer can select a set of carriers that includes only carriers on which PSFCH is set (e.g., or a carrier including a resource pool on which PSFCH is set) among the carriers received from the higher layer as a set of carriers used for multicarrier operation for DTX-based RLF declaration.

[0308] For example, 3) A set of all carriers for which PSFCH is configured among multiple carriers selected (e.g., It is left to UE implementation how many carriers to select based on UE Capability) by the UE among the carrier set configured by the Network) selected by the UE from among the carrier set configured by the Network

[0309] The terminal can receive a carrier set for multi-carriers (e.g., or carrier aggregation) mapped to a service (e.g., a pair of Source Layer-2 ID / Destination Layer-2 IDs or a service associated with a pair of Source Layer-2 ID / Destination Layer-2 IDs or a QoS flow(s) associated with a pair of Source Layer-2 ID / Destination Layer-2 IDs) from the base station. The terminal can select a carrier set that includes only carriers for which a PSFCH is set (e.g., a carrier including a resource pool for which a PSFCH is set) among the carriers received from the base station (e.g., or the terminal selects a carrier set to be used for multi-carrier operation among the carriers received from the base station and selects the carrier set) as a carrier set to be used for multi-carrier operation for DTX-based RLF declaration.

[0310] For example, the present disclosure may propose a method for selecting and / or limiting sidelink carriers / SL BWP / SL HARQ entities used for SL RLF-related DTX counting of a multi-carrier supporting terminal as follows. The terminal may perform SL DTX counting (e.g., numConsecutiveDTX) only for sidelink carriers / SL BWP / SL HARQ entities that satisfy the following conditions among multiple sidelink carriers / SL BWP / SL HARQ entities related to a unicast session or a PC5 RRC connection.

[0311] For example, 1) Perform SL DTX counting (e.g., numConsecutiveDTX) by selecting a sidelink carrier / SL BWP / SL HARQ entity that is lower (e.g., higher) than a pre-configured CBR threshold. The CBR threshold can be configured on a priority-by-priority basis, a QoS profile-by-QoS profile basis (e.g., PDB, reliability), a SL radio bearer basis, or a logical channel basis.

[0312] For example, 2) Sidelink carrier / SL BWP / SL HARQ entity with PSFCH set up

[0313] For example, 3) a sidelink carrier / SL BWP / SL HARQ entity whose remaining CR value is higher (e.g., lower) than the congestion control-related CR limit value (e.g., than a preset threshold).

[0314] For example, 4) a sidelink carrier / SL BWP / SL HARQ entity to which pre-configured messages (e.g., PC5 RRC reconfiguration related PC5 RRC messages (e.g., RRC Reconfiguration (Sidelink) (e.g., RRCReconfiguration(Sidelink)), RRC Reconfiguration Complete (Sidelink) (e.g., RRCReconfigurationComplete(Sidelink)), RRC Reconfiguration Failure (Sidelink) (e.g., RRCReconfigurationFailure(Sidlelink))), PC5-S signal (e.g., DCR / DCA messages), sidelink messages using SL SRB 0 / SL SRB 1 / SL SRB 2 / SL SRB 3 / SL SRB 4, etc.) are transmitted.

[0315] For example, 5) the sidelink carrier / SL BWP / SL HARQ entity through which the pre-configured sidelink channel / signal (e.g. SL-SSB) is (actually) transmitted.

[0316] For example, 6) (e.g., limited to sidelink carrier / SL BWP / SL HARQ entity agreed between terminals, sidelink carrier / SL BWP / SL HARQ entity with lowest or highest or preset index, etc.)

[0317] For example, 7) A sidelink carrier / SL BWP / SL HARQ entity that transmits packets with sidelink priority or sidelink reliability above a preset threshold level.

[0318] For example, 8) a sidelink carrier / SL BWP / SL HARQ entity configured with an LCH (e.g., or an RB providing HARQ feedback enabled data) having the HARQ feedback enabled attribute.

[0319] For example, 9) a sidelink carrier / SL BWP / SL HARQ entity (e.g., a sidelink carrier / SL BWP / SL HARQ entity) to which PC5 RRC signaling (e.g., RRC Reset (sidelink) (e.g., RRCReconfiguration(Sidelink)), RRC Reset Complete (sidelink) (e.g., RRCReconfigurationComplete(Sidelink)), RRC Reset Failure (sidelink) (e.g., RRCReconfigurationFailure(Sidlelink))) is transmitted (or a sidelink carrier / SL BWP / SL HARQ entity) to which a pre-configured PC5-S message (e.g., DCR message) is transmitted)

[0320] For example, PSFCH reception may be performed. For example, the MAC entity may perform a HARQ-based (sidelink) RLF detection procedure for each PSSCH transmission. For example, the MAC entity may perform a HARQ-based (sidelink) RLF detection procedure for each PSSCH transmission if the PSSCH transmission occurs for a pair of source Layer-2 IDs and destination Layer-2 IDs corresponding to a PC5-RRC connection established by a higher layer.

[0321] For example, a HARQ-based (sidelink) RLF detection procedure can be used to detect a (sidelink) RLF based on the number of consecutive discontinuous transmissions (DTXs) ​​in a PSFCH reception opportunity (occasion) for a PC5-RRC connection. For example, for each carrier associated with the PC5-RRC connection, a HARQ-based (sidelink) RLF detection procedure can be used to detect a (sidelink) RLF based on the number of consecutive discontinuous transmissions (DTXs) ​​in a PSFCH reception opportunity (occasion) for the PC5-RRC connection.

[0322] For example, RRC can set the following parameters to control HARQ-based (sidelink) RLF detection. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) can be set. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) can indicate the maximum number of DTX (e.g., consecutive HARQ DTX) before triggering an RLF.

[0323] For example, the following UE variables can be used for HARQ-based (sidelink) RLF detection: For example, the DTX maintained for each PC5-RRC connection (e.g., numConsecutiveDTX) can be set. For example, the DTX maintained for each carrier for each PC5-RRC connection (e.g., numConsecutiveDTX) can be set.

[0324] For example, the (sidelink) HARQ entity may (re)initialize the DTX (e.g., numConsecutiveDTX) to 0 for each PC5-RRC connection established from the upper layer, if any, upon establishment of the PC5-RRC connection or upon (re)establishment of the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX). For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may (re)initialize the DTX (e.g., numConsecutiveDTX) to 0 for each PC5-RRC connection established from the upper layer, if any, upon establishment of the PC5-RRC connection or upon (re)establishment of the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX). For example, as illustrated in FIG. 18, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) may be set to 3. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) may not be limited to 3. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) may be (re)set to a value other than 3.

[0325] For example, the (sidelink) HARQ entity may increment the DTX (e.g., numConsecutiveDTX) by 1 for each PSFCH reception opportunity associated with a PSSCH transmission. For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may increment the DTX (e.g., numConsecutiveDTX) by 1 for each PSFCH reception opportunity associated with a PSSCH transmission. For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may increment the DTX (e.g., numConsecutiveDTX) by 1 for each PSFCH reception opportunity associated with a PSSCH transmission if there is no PSFCH reception in the PSFCH reception opportunity. For example, in (SL) operation with shared spectrum channel access, a terminal (e.g., UE) may increment DTX (e.g., numConsecutiveDTX) by 1 when the terminal (e.g., UE) fails to detect HARQ feedback on all relevant PSFCH resources.

[0326] For example, the (sidelink) HARQ entity may trigger a TX carrier (re)selection procedure for each PSFCH reception opportunity associated with a PSSCH transmission. For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may trigger a TX carrier (re)selection procedure for each PSFCH reception opportunity associated with a PSSCH transmission. For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may trigger a TX carrier (re)selection procedure for each PSFCH reception opportunity associated with a PSSCH transmission if one or more of the selected carriers are considered as carriers for HARQ-based (sidelink) RLF detection. For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may trigger a TX carrier (re)selection procedure for each PSFCH reception opportunity associated with a PSSCH transmission if the DTX (e.g., numConsecutiveDTX) reaches the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) for the carrier for which HARQ-based (sidelink) RLF detection applies. For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may trigger a TX carrier (re)selection procedure for each PSFCH reception opportunity associated with a PSSCH transmission, if one or more selected carriers are considered as carriers for HARQ-based (sidelink) RLF detection, if the DTX (e.g., numConsecutiveDTX) reaches the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) for the carriers subject to HARQ-based (sidelink) RLF detection.For example, in triggering a TX carrier (re)selection procedure, the TX carrier (re)selection procedure may be triggered as initiated in the TX carrier (re)selection below. For example, in the selected one or more carriers, the carrier may be selected as initiated in the TX carrier (re)selection below. For example, as illustrated in FIG. 19, for a first carrier, which is one of each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may, for each PSFCH reception opportunity associated with a PSSCH transmission, if the first carrier, which is one of the selected one or more carriers, is considered as a carrier for HARQ-based (sidelink) RLF detection, if the DTX (e.g., numConsecutiveDTX) reaches 3, which is the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) for the first carrier that is applied for HARQ-based (sidelink) RLF detection, then trigger the TX carrier (re)selection procedure. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) may not be limited to 3. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) may be (re)set to a value other than 3.

[0327] For example, the (sidelink) HARQ entity may instruct RRC to perform HARQ-based (sidelink) carrier failure detection for each PSFCH reception opportunity associated with a PSSCH transmission. For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may instruct RRC to perform HARQ-based (sidelink) carrier failure detection for each PSFCH reception opportunity associated with a PSSCH transmission. For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may instruct RRC to perform HARQ-based (sidelink) carrier failure detection for each PSFCH reception opportunity associated with a PSSCH transmission if one or more of the selected carriers are considered as carriers for HARQ-based (sidelink) RLF detection. For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may instruct RRC for HARQ-based (sidelink) carrier failure detection, for each PSFCH reception opportunity associated with a PSSCH transmission, if the DTX (e.g., numConsecutiveDTX) for the carrier applicable for HARQ-based (sidelink) RLF detection reaches the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX). For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may, for each PSFCH reception opportunity associated with a PSSCH transmission, instruct RRC to perform HARQ-based (sidelink) carrier failure detection if the DTX (e.g., numConsecutiveDTX) for the selected carriers is considered as a carrier for HARQ-based (sidelink) RLF detection, and if the DTX (e.g., numConsecutiveDTX) reaches the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) for the carriers subject to HARQ-based (sidelink) RLF detection.For example, from the selected one or more carriers, the carrier may be selected as disclosed in the TX carrier (re)selection below. For example, as illustrated in FIG. 19, for each PSFCH reception opportunity associated with a PSSCH transmission, for a first carrier, which is one of the selected one or more carriers, the (sidelink) HARQ entity may instruct RRC to perform HARQ-based (sidelink) carrier failure detection if the first carrier, which is one of the selected one or more carriers, is considered as a carrier for HARQ-based (sidelink) RLF detection, and if the DTX (e.g., numConsecutiveDTX) reaches 3, which is the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) for the first carrier, which is a carrier applied for HARQ-based (sidelink) RLF detection. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) may not be limited to 3. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) can be (re)set to a value other than 3.

[0328] For example, the (sidelink) HARQ entity may instruct RRC to perform HARQ-based (sidelink) RLF detection for each PSFCH reception opportunity associated with a PSSCH transmission. For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may instruct RRC to perform HARQ-based (sidelink) RLF detection for each PSFCH reception opportunity associated with a PSSCH transmission. For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may instruct RRC to perform HARQ-based (sidelink) RLF detection for each PSFCH reception opportunity associated with a PSSCH transmission if one or more of the selected carriers are considered as carriers for HARQ-based (sidelink) RLF detection. For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may instruct RRC for HARQ-based (sidelink) RLF detection, for each PSFCH reception opportunity associated with a PSSCH transmission, if the DTX (e.g., numConsecutiveDTX) reaches the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) for all carriers for which HARQ-based (sidelink) RLF detection applies. For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may, for each PSFCH reception opportunity associated with a PSSCH transmission, instruct RRC to perform HARQ-based (sidelink) RLF detection if one or more selected carriers are considered as carriers for HARQ-based (sidelink) RLF detection, and if the DTX (e.g., numConsecutiveDTX) reaches the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) for all carriers subject to HARQ-based (sidelink) RLF detection.For example, from the selected one or more carriers, the carrier may be selected as disclosed in the TX carrier (re)selection below. For example, as illustrated in FIG. 19, for each carrier associated with the PC5-RRC connection, a (sidelink) HARQ entity may, for each PSFCH reception opportunity associated with the PSSCH transmission, instruct the RRC to perform HARQ-based (sidelink) RLF detection if the selected one or more carriers, the first carrier and the second carrier, are considered as carriers for HARQ-based (sidelink) RLF detection, if the DTX (e.g., numConsecutiveDTX) reaches 3, which is the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) for all carriers applicable to HARQ-based (sidelink) RLF detection, the first carrier and the second carrier. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) may not be limited to 3. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) can be (re)set to a value other than 3.

[0329] For example, the (sidelink) HARQ entity may instruct RRC to perform HARQ-based (sidelink) RLF detection for each PSFCH reception opportunity associated with a PSSCH transmission if the DTX (e.g., numConsecutiveDTX) reaches a maximum DTX (e.g., (sl-)maxNumConsecutiveDTX). For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may instruct RRC to perform HARQ-based (sidelink) RLF detection for each PSFCH reception opportunity associated with a PSSCH transmission if the DTX (e.g., numConsecutiveDTX) reaches a maximum DTX (e.g., (sl-)maxNumConsecutiveDTX). For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may, for each PSFCH reception opportunity associated with a PSSCH transmission, instruct RRC to perform HARQ-based (sidelink) RLF detection if the selected one or more carriers are not considered as carriers for HARQ-based (sidelink) RLF detection (e.g., else for “if the selected one or more carriers are considered as carriers for HARQ-based (sidelink) RLF detection”), and if the DTX (e.g., numConsecutiveDTX) reaches a maximum DTX (e.g., (sl-)maxNumConsecutiveDTX). For example, among the selected one or more carriers, a carrier may be selected as initiated in TX carrier (re)selection below. For example, as illustrated in FIG. 18, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) may be set to 3.For example, as illustrated in FIG. 18, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may, for each PSFCH reception opportunity associated with a PSSCH transmission, instruct RRC to perform HARQ-based (sidelink) RLF detection if one or more of the selected carriers are not considered as carriers for HARQ-based (sidelink) RLF detection (e.g., else for “if one or more of the selected carriers are considered as carriers for HARQ-based (sidelink) RLF detection”), and if the DTX (e.g., numConsecutiveDTX) reaches a maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) of 3. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) may not be limited to 3. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) can be (re)set to a value other than 3.

[0330] For example, the (sidelink) HARQ entity may reinitialize the DTX (e.g., numConsecutiveDTX) to 0 for each PSFCH reception opportunity associated with a PSSCH transmission. For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may reinitialize the DTX (e.g., numConsecutiveDTX) to 0 for each PSFCH reception opportunity associated with a PSSCH transmission. For example, for each carrier associated with a PC5-RRC connection, the (sidelink) HARQ entity may reinitialize the DTX (e.g., numConsecutiveDTX) to 0 for each PSFCH reception opportunity associated with a PSSCH transmission, unless there is no PSFCH reception in the PSFCH reception opportunity (e.g., if else for “if there is no PSFCH reception in the PSFCH reception opportunity”).

[0331] By not indicating an RLF when a DTX peak is detected only in some carriers, the PC5-RRC connection can be prevented from being terminated due to an RLF being indicated even when a DTX peak is not detected in any of the multiple carriers, thereby preventing the PC5-RRC connection from being terminated due to an RLF being indicated even when there are available carriers where a DTX peak is not detected. By indicating an RLF only when a DTX peak is detected in multiple carriers, the PC5-RRC connection can be prevented from being terminated due to an RLF being indicated even when there are available carriers where a DTX peak is not detected. By terminating the PC5-RRC connection only when a DTX peak is detected in multiple carriers, the PC5-RRC connection can be prevented from being terminated even when there are available carriers where a DTX peak is not detected.

[0332] For example, TX carrier (re)selection may be performed.

[0333] For example, if a CBR measurement result is available, the MAC entity can consider the CBR of the carrier as being measured by the lower layer. For example, if a CBR measurement result is available, the MAC entity can consider the CBR of the carrier as being measured by the lower layer. For example, if a CBR measurement result is not available, the MAC entity can consider the CBR of the carrier as being set by the corresponding index (e.g., (sl-)defaultTxConfigIndex) from the upper layer.

[0334] For example, if TX carrier (re)selection is triggered for a (sidelink) process, the MAC entity may consider a carrier as a candidate carrier for TX carrier (re)selection for the concerned (sidelink) logical channel. For example, if TX carrier (re)selection is triggered for a (sidelink) process, the MAC entity may consider a carrier as a candidate carrier for TX carrier (re)selection for the concerned (sidelink) logical channel if a (sidelink) grant has not been selected on all allowed carriers for the (sidelink) logical channel on which data is available as instructed by the upper layers. For example, if TX carrier (re)selection is triggered for a (sidelink) process, for each carrier configured by the upper layers associated with the concerned (sidelink) logical channel, the MAC entity may consider a carrier as a candidate carrier for TX carrier (re)selection for the concerned (sidelink) logical channel. For example, if TX carrier (re)selection is triggered for a (sidelink) process, if the CBR of the carrier is lower than a CBR threshold associated with the priority of the (sidelink) logical channel (e.g., (sl-)threshCBR-FreqReselection), the MAC entity may consider the carrier as a candidate carrier for TX carrier (re)selection for the concerned (sidelink) logical channel. For example, if TX carrier (re)selection is triggered for a (sidelink) process, taking into account HARQ feedback enablement for the (sidelink) logical channel (e.g., (sl-)HARQ-FeedbackEnabled), the MAC entity may consider the carrier as a candidate carrier for TX carrier (re)selection for the concerned (sidelink) logical channel.For example, if TX carrier (re)selection is triggered for a (sidelink) process, and if multiple resource pools are configured on the carrier, it is up to the UE implementation which particular resource pool is used to determine the CBR of this carrier, and the MAC entity may consider the carrier as a candidate carrier for TX carrier (re)selection for the concerned (sidelink) logical channel. For example, if TX carrier (re)selection is triggered for a (sidelink) process, and if multiple resource pools are configured on the carrier, it is up to the UE implementation which particular resource pool is used to determine the CBR of this carrier, and the MAC entity may consider the carrier as a candidate carrier for TX carrier (re)selection for the concerned (sidelink) logical channel, taking into account HARQ feedback enable (e.g., (sl-)HARQ-FeedbackEnabled) for the (sidelink) logical channel.For example, when a TX carrier (re)selection is triggered for a (sidelink) process, if a (sidelink) grant is not selected on all allowed carriers for a (sidelink) logical channel for which data is available as instructed by upper layers, then for each carrier configured by upper layers associated with the concerned (sidelink) logical channel, if the CBR of the carrier is lower than a CBR threshold (e.g., (sl-)threshCBR-FreqReselection) associated with the priority of the (sidelink) logical channel, the MAC entity, taking into account HARQ feedback enablement for the (sidelink) logical channel (e.g., (sl-)HARQ-FeedbackEnabled), determines which particular resource pool is used to determine the CBR of this carrier if multiple resource pools are configured on the carrier, and it is up to the UE implementation which specific resource pool is used to determine the CBR of this carrier, and the MAC entity determines whether the carrier is selected for the TX carrier for the concerned (sidelink) logical channel. It can be considered as a candidate carrier for (re)selection.

[0335] For example, if TX carrier (re)selection is triggered for a (sidelink) process, the MAC entity may select a carrier and a pool of associated (e.g., carrier-associated) resources. For example, if TX carrier (re)selection is triggered for a (sidelink) process, if at least one (sidelink) grant has been selected on all allowed carriers for data-available (sidelink) logical channels as indicated by higher layers (e.g., if “no (sidelink) grant has been selected on all allowed carriers for data-available (sidelink) logical channels as indicated by higher layers”), the MAC entity may select a carrier and a pool of associated (e.g., carrier-associated) resources. For example, if a TX carrier (re)selection is triggered for a (sidelink) process, then for each (sidelink) logical channel allowed on the carrier for which data is available and for which TX carrier (re)selection is triggered, the MAC entity may select a carrier and a pool of associated (e.g., carrier-associated) resources, if any. For example, if a TX carrier (re)selection is triggered for a (sidelink) process, then for each (sidelink) logical channel allowed on the carrier for which data is available and for which TX carrier (re)selection is triggered, the MAC entity may select a carrier and a pool of associated (e.g., carrier-associated) resources, if any, if the CBR of the carrier is lower than a threshold associated with the priority of the (sidelink) logical channel (e.g., (sl-)threshCBR-FreqKeeping).For example, when TX carrier (re)selection is triggered for a (sidelink) process, for each (sidelink) logical channel allowed on the carrier for which data is available and for which TX carrier (re)selection is triggered, the MAC entity, if any, may select a pool of resources from the carrier and its associated (e.g., associated with the carrier) resources, if the CBR of the carrier is lower than a threshold associated with the priority of the (sidelink) logical channel (e.g., (sl-)threshCBR-FreqKeeping). For example, if TX carrier (re)selection is triggered for a (sidelink) process, if at least one (sidelink) grant has been selected on all allowed carriers for (sidelink) logical channels on which data is available as indicated by upper layers (e.g., if “no (sidelink) grant has been selected on all allowed carriers for (sidelink) logical channels on which data is available as indicated by upper layers”), then for each allowed (sidelink) logical channel on which data is available and for which TX carrier (re)selection is triggered, if the CBR of the carrier, if any, is lower than a threshold associated with the priority of the (sidelink) logical channel (e.g., (sl-)threshCBR-FreqKeeping), then the MAC entity, if any, is assigned to the carrier and its associated (e.g., associated with the carrier) You can choose a pool of resources.

[0336] For example, if TX carrier (re)selection is triggered for a (sidelink) process, the MAC entity may consider, for each carrier configured by the upper layers for which (sidelink) logical channels are allowed, a carrier as a candidate carrier for TX carrier (re)selection. For example, if TX carrier (re)selection is triggered for a (sidelink) process, if at least one (sidelink) grant has been selected on all allowed carriers for data-available (sidelink) logical channels as indicated by the upper layers (e.g., if no (sidelink) grant has been selected on all allowed carriers for data-available (sidelink) logical channels as indicated by the upper layers) (else), the MAC entity may consider, for each carrier configured by the upper layers for which (sidelink) logical channels are allowed, a carrier as a candidate carrier for TX carrier (re)selection. For example, when a TX carrier (re)selection is triggered for a (sidelink) process, if data is not available, or there is no (sidelink) logical channel allowed on the carrier for which a TX carrier (re)selection is triggered, or for each (sidelink) logical channel allowed on the carrier for which data is available and a TX carrier (re)selection is triggered, if any, then the CBR of the carrier is higher than a threshold associated with the priority of the (sidelink) logical channel (e.g., (sl-)threshCBR-FreqKeeping) or equal to a threshold associated with the priority of the (sidelink) logical channel (e.g., (sl-)threshCBR-FreqKeeping) (e.g., "data is available and a TX carrier (re)selection is triggered, for each (sidelink) logical channel allowed on the carrier for which a TX carrier (re)selection is triggered, if any,For each (sidelink) logical channel allowed on the carrier for which data is available and TX carrier (re)selection is triggered, if the CBR of the carrier is lower than a threshold (e.g., (sl-)threshCBR-FreqKeeping), then the MAC entity may, for each carrier configured by the upper layer for which (sidelink) logical channels are allowed, consider the carrier as a candidate carrier for TX carrier (re)selection. For example, if TX carrier (re)selection is triggered for the (sidelink) process, then for each carrier configured by the upper layer for which (sidelink) logical channels are allowed, the MAC entity may, for each carrier configured by the upper layer for which (sidelink) logical channels are allowed, consider the carrier as a candidate carrier for TX carrier (re)selection. For example, if TX carrier (re)selection is triggered for the (sidelink) process, then if the CBR of the carrier is lower than a threshold (e.g., (sl-)threshCBR-FreqKeeping) for the (sidelink) logical channels, then For each carrier configured by the upper layer for which the (sidelink) logical channel is allowed, the MAC entity may consider the carrier as a candidate carrier for TX carrier (re)selection if the CBR of the carrier is lower than a threshold associated with the priority of the channel (e.g., (sl-)threshCBR-FreqReselection). For example, when TX carrier (re)selection is triggered for the (sidelink) process, for each carrier configured by the upper layer for which the (sidelink) logical channel is allowed, the MAC entity may consider the carrier as a candidate carrier for TX carrier (re)selection if the CBR of the carrier is lower than a threshold associated with the priority of the (sidelink) logical channel (e.g., (sl-)threshCBR-FreqReselection). For example,If TX carrier (re)selection is triggered for a (sidelink) process, if at least one (sidelink) grant has been selected on all allowed carriers for (sidelink) logical channels on which data is available as indicated by upper layers (e.g., if “no (sidelink) grant has been selected on all allowed carriers for (sidelink) logical channels on which data is available as indicated by upper layers”), then TX carrier (re)selection is triggered for a (sidelink) process, if data is not available, or there are no (sidelink) logical channels allowed on the carrier for which TX carrier (re)selection is triggered, or for each (sidelink) logical channel on the carrier for which data is available and TX carrier (re)selection is triggered, if any, the CBR of the carrier is higher than a threshold (e.g., (sl-)threshCBR-FreqKeeping) associated with the priority of the (sidelink) logical channel and If the associated threshold (e.g., (sl-)threshCBR-FreqKeeping) is equal to (e.g., “for each (sidelink) logical channel allowed on the carrier for which data is available and TX carrier (re)selection is triggered, if the carrier’s CBR is lower than the threshold associated with the priority of the (sidelink) logical channel (e.g., (sl-)threshCBR-FreqKeeping)”, then (else for “for each (sidelink) logical channel allowed on the carrier for which data is available and TX carrier (re)selection is triggered, if any”), if the carrier’s CBR is lower than the threshold associated with the priority of the (sidelink) logical channel (e.g., (sl-)threshCBR-FreqReselection)For each carrier configured by the upper layer for which (sidelink) logical channels are allowed, if the CBR of the carrier is lower than a threshold value (e.g., (sl-)threshCBR-FreqReselection) associated with the priority of the (sidelink) logical channel, the MAC entity may, for each carrier configured by the upper layer for which (sidelink) logical channels are allowed, consider the carrier as a candidate carrier for TX carrier (re)selection.

[0337] For example, the MAC entity may select one or more carriers from among the candidate carriers. For example, the MAC entity may select one or more carriers and a pool of associated (e.g., associated) resources from among the candidate carriers. For example, the MAC entity may select one or more carriers from among the candidate carriers in order of increasing CBR starting from the lowest CBR. For example, the MAC entity may select one or more carriers from among the candidate carriers and a pool of associated (e.g., associated) resources from among the candidate carriers in order of increasing CBR starting from the lowest CBR. For example, if one or more carriers are considered as candidate carriers for TX carrier (re)selection, the MAC entity may select one or more carriers from among the candidate carriers and a pool of associated (e.g., associated) resources from among the candidate carriers in order of increasing CBR starting from the lowest CBR. For example, if TX carrier (re)selection is triggered for each (sidelink) logical channel on which data is allowed on the available carrier, the MAC entity may select one or more carriers and a pool of associated (e.g., associated with one or more carriers) resources from among the candidate carriers in increasing order of CBR, starting from the lowest.For example, if more than one carrier is considered as a candidate carrier for TX carrier (re)selection, and if TX carrier (re)selection is triggered for each (sidelink) logical channel allowed on the data-available carrier, the MAC entity may select one or more carriers and a pool of associated (e.g., associated with one or more carriers) resources from among the candidate carriers in order of increasing CBR, starting with the lowest CBR.

[0338] For example, the MAC entity can select a pool of resources (e.g., one pool of resources) for which PSFCH resources are configured from among the pools of resources. For example, if enable is set for a (sidelink) logical channel, the MAC entity can select a pool of resources (e.g., one pool of resources) for which PSFCH resources are configured from among the pools of resources. For example, if enable is set for a (sidelink) logical channel, the MAC entity can select a pool of resources (e.g., one pool of resources) for which PSFCH resources are configured from among the pools of resources, excluding the pools in the information related to discovery of resource pools (e.g., (sl-)BWP-DiscPoolConfig or (sl-)BWP-DiscPoolConfigCommon), if configured. For example, the MAC entity may select one or more carriers and a pool of resources associated with them (e.g., associated with one or more carriers) from among the candidate carriers, and if the enable is set for the (sidelink) logical channel, the MAC entity may select a pool of resources for which PSFCH resources are configured (e.g., one of the pools of resources), excluding the pools in the information related to discovery of resource pools (e.g., (sl-)BWP-DiscPoolConfig or (sl-)BWP-DiscPoolConfigCommon), if configured.

[0339] For example, a MAC entity may select any pool of resources from among the pools of resources. For example, if disable is set for a (sidelink) logical channel, the MAC entity may select any pool of resources from among the pools of resources. For example, if disable is set for a (sidelink) logical channel, the MAC entity may select any pool of resources from among the pools of resources, excluding pools in the information related to discovery of resource pools (e.g., (sl-)BWP-DiscPoolConfig or (sl-)BWP-DiscPoolConfigCommon), if set. For example, a MAC entity may select one or more carriers and a pool of resources associated with them (e.g., associated with one or more carriers) from among the candidate carriers, and if a disable is set for a (sidelink) logical channel, the MAC entity may select all pools of resources from among the pools of resources, excluding pools in the information related to discovery of resource pools (e.g., (sl-)BWP-DiscPoolConfig or (sl-)BWP-DiscPoolConfigCommon), if set.

[0340] For example, it may be left to the UE implementation to decide how many carriers to select based on UE performance.

[0341] For example, it may be left to the UE implementation to determine which (sidelink) logical channel is allowed on the carrier for which data is available and TX carrier (re)selection is triggered.

[0342] In FIG. 19, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) is shown to be set to 3, but is not limited thereto. For example, the maximum DTX (e.g., (sl-)maxNumConsecutiveDTX) may be (re)set to a value other than 3.

[0343] FIG. 20 illustrates a procedure for LBT detection according to an embodiment of the present disclosure. The embodiment of FIG. 20 may be combined with various embodiments of the present disclosure.

[0344] Referring to FIG. 20, the (side link) LBT operation can be illustrated as follows.

[0345] In (SL-)U(unlicensed), the terminal may first have to occupy a channel in the (sidelink) unlicensed band to transmit (SL) data. For example, in order to occupy a channel in the (sidelink) unlicensed band, the terminal may perform LBT (e.g., type 1 LBT: random backoff-based LBT) to find a channel in the unlicensed band that is not occupied by the terminal. For example, if the 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 contention window size, etc.) to perform LBT again and continue the process of finding a channel in the unlicensed band that is not occupied by the terminal.

[0346] For example, the present disclosure may propose the following actions for resource (re-)selection of a terminal when LBT (e.g., one shot LBT or consistent LBT) fails (e.g., the process of finding an unoccupied channel fails).

[0347] For example, when a LBT (e.g., one shot LBT or consistent LBT) failure for a (sidelink) TB (transport block) transmission is detected, the terminal may reselect resources by replacing the resources selected from the set of RBs (e.g., resource blocks) (RBs) (e.g., or (sidelink) resource pools) where the LBT (e.g., one shot LBT or consistent LBT) failure occurred with resources from another set of RBs (e.g., or (sidelink) resource pools) where the LBT failure occurred without clearing the (sidelink) grant.

[0348] For example, in an embodiment of the present disclosure, when an LBT (e.g., one shot LBT or consistent LBT) failure is detected, if there is an ongoing (sidelink) TB transmission in the RB set (e.g., or (sidelink) resource pool) where the LBT (e.g., one shot or consistent) failure occurred, the terminal may either continue the related (remaining) (re)transmission using reselected resources in another RB set (e.g., or (sidelink) resource pool) or drop the ongoing (sidelink) TB.

[0349] For example, in an embodiment of the present disclosure, when an LBT (e.g., one shot or consistent) failure for a (sidelink) TB transmission is detected, a (sidelink) grant selected from a RB set (e.g., or a (sidelink) resource pool) where an LBT (e.g., one shot LBT or consistent LBT) failure occurred may be cleared, and a (sidelink) grant may be regenerated from another RB set (e.g., or a (sidelink) resource pool) where an LBT failure did not occur.

[0350] For example, in an embodiment of the present disclosure, when an LBT (e.g., one shot LBT or consistent LBT) failure is detected, if there is a TB transmission in progress in the RB set (e.g., or (sidelink) resource pool) where the LBT (e.g., one shot or consistent) failure occurred, the related (remaining) (re)transmission can be continued using a (sidelink) grant generated on another RB set (e.g., or (sidelink) resource pool), or the (sidelink) TB in progress can be dropped.

[0351] For example, in an embodiment of the present disclosure, when an LBT (e.g., one shot or consistent) failure for a (sidelink) TB transmission is detected, the terminal may clear a (sidelink) grant selected from the RB set (e.g., or (sidelink) resource pool) where the LBT (e.g., one shot or consistent) failure occurred and / or drop the (sidelink) TB transmission that was in progress.

[0352] For example, in an embodiment of the present disclosure, when a (sidelink) TB transmission encounters an LBT failure (e.g., one shot or consistent), if the terminal selects a reserved resource for the (sidelink) TB transmission but does not transmit the reserved resource to the peer (e.g., peer) terminal by indicating the SCI, all resources (e.g., initial transmission resources and retransmission resources) reserved for the (sidelink) TB encountering the (one shot or consistent) LBT failure may be reselected to other resources (from the RB set or resource pool where the LBT failure did not occur). For example, when a LBT failure (e.g., one shot or consistent) occurs for a (sidelink) TB transmission, if the terminal has selected a reserved resource for the (sidelink) TB transmission and has transmitted the reserved resource to the peer (e.g., peer) terminal by indicating the SCI, the terminal can reselect the resource or resources (e.g., initial transmission resource or retransmission resource) on which the LBT failure (e.g., one shot or consistent) occurred to another resource (on the RB set or resource pool on which the LBT failure did not occur).

[0353] For example, the present disclosure can be equally extended and applied to a case where a terminal performs multiple consecutive slot transmission (MCSt)-based operations (terminal operations when MCSt resources are allocated) in a (sidelink).

[0354] For example, MCSt: (Sidelink) slots less than or equal to a certain gap can be allocated as transmission resources for (sidelink) transmission consecutively. The terminal can transmit the same (sidelink) TB or multiple (sidelink) TBs using multiple consecutive slots. For example, the terminal can perform LBT in the first slot and transmit the (sidelink) TB without performing LBT for the (sidelink) TB transmitted through the subsequent consecutive slots (consecutive slot(s) less than or equal to a certain gap). For example, performing MCSt-based (sidelink) transmission has the effect of reducing overhead of transmission operations (e.g., performing LBT) in the (sidelink) unlicensed band, since (sidelink) data can be transmitted without performing LBT during the gap between consecutive slot(s) for (sidelink) transmission.

[0355] For example, in an embodiment of the present disclosure, when a LBT failure (e.g., one shot or consistent) occurs for a MCSt-based (sidelink) TB transmission, if the terminal has selected a reserved resource for the (sidelink) TB transmission but has not transmitted the reserved resource to the peer (e.g., peer) terminal by indicating the reserved resource in the SCI, the terminal may reselect all resources (e.g., initial transmission resources and retransmission resources or resources reserved on all slots of MCSt) reserved for the (sidelink) TB for which a one shot or consistent) LBT failure has occurred to other resources (from the RB set or resource pool in which the LBT failure has not occurred). For example, when a LBT failure (e.g., one shot or consistent) occurs for MCSt-based (sidelink) TB transmission, if the terminal has selected a reserved resource for the (sidelink) TB transmission and has indicated the reserved resource in the SCI to transmit it to the counterpart (e.g., peer) terminal, the terminal may reselect the resource or resources on which the LBT failure (e.g., one shot or consistent) occurred (e.g., only the initial transmission resource or only the retransmission resource or only the resources on the slots of MCSt on which the LBT failure occurred) to another resource (on the RB set or the resource pool on which the LBT failure did not occur).

[0356] For example, in an embodiment of the present disclosure, when a terminal triggers or declares a (sidelink) consistent LBT failure in a (sidelink) RB set (e.g., or a (sidelink) resource pool), if there is no (sidelink) resource block (RB) set in which a (sidelink) consistent LBT failure has not occurred within the (sidelink) resource pool being used or configured, the terminal may trigger a resource reselection procedure and reselect a (sidelink) RB set in the (sidelink) resource pool in which a (sidelink) consistent LBT failure has not occurred, or in which a (sidelink) LBT failure has occurred below a preset threshold, to perform (sidelink) data transmission.

[0357] For example, in an embodiment of the present disclosure, if a terminal triggers or declares a (sidelink) consistent LBT failure in a (sidelink) RB set (e.g., or a (sidelink) resource pool), and there is no (sidelink) resource block (RB) set (e.g., or a (sidelink) resource pool) in use or configured (sidelink) resource pool (e.g., or a (sidelink) RB set) in which a (sidelink) (consistent) LBT failure has not occurred, the terminal may terminate all (sidelink) sessions (unicast or groupcast or broadcast) configured by the terminal, declare an (SL) RLF for all unicast sessions in case of unicast, and perform a MAC reset procedure for MAC operations related to all unicast sessions / groupcast sessions / broadcast sessions.

[0358] For example, in an embodiment of the present disclosure, a terminal supporting multi-carrier operation triggers or declares a (sidelink) consistent LBT failure in a (sidelink) RB set (e.g., or a (sidelink) resource pool) of a specific (sidelink) carrier, and if there is no (sidelink) resource block (RB) set (e.g., or a (sidelink) resource pool) in use or configured in the specific (sidelink) carrier in which a (sidelink) (consistent) LBT failure has not occurred, triggers a carrier reselection procedure for reselecting another (sidelink) carrier, and selects a (sidelink) resource block (RB) in which a (sidelink) (consistent) LBT failure has not occurred (e.g., a (sidelink) LBT failure below a preset threshold level has occurred). A (sidelink) carrier can be reselected for which a set (e.g., or (sidelink) resource pool) exists.

[0359] For example, in an embodiment of the present disclosure, a terminal may additionally perform (Type 1) LBT check-based PSCCH / PSSCH or PSFCH transmission in a (sidelink) RB set (e.g., or a (sidelink) resource pool) in which a (sidelink) (consistent) LBT failure is triggered (e.g., or declared) for a PSCCH / PSSCH or PSFCH transmission having a (sidelink) priority higher than a preset threshold level (e.g., or a (SL) CAPC with a priority higher than a preset threshold level).

[0360] For example, in an embodiment of the present disclosure, if the granularity for triggering or detection of (sidelink) consistent LBT failure is per (sidelink) resource pool (e.g., or per (SL) BWP), the UE may use only some RB sets within the (sidelink) resource pool (e.g., or (SL) BWP) where (sidelink) consistent LBT failure is triggered (or declared) as RB sets associated with (SL) (consistent) LBT failure declarations, while the remaining RB sets not associated with (SL) (consistent) LBT failure declarations may be used for (sidelink) grant generation or resource reselection. For example, if the granularity for triggering or detection of (sidelink) consistent LBT failure is per (sidelink) resource pool (e.g., or per (SL) BWP), the UE shall not use any RB set within the (sidelink) resource pool (e.g., or (SL) BWP) where (sidelink) consistent LBT failure is triggered (e.g., declared) as an RB set associated with the (SL) (consistent) LBT failure declaration, for (sidelink) grant generation or resource reselection, the remaining RB sets not associated with the (SL) (consistent) LBT failure declaration.

[0361] For example, a (sidelink specific) consistent LBT failure may be initiated. For example, an (SL-specific) consistent LBT failure detection and recovery procedure may be supported (e.g., for SL-U). When a UE detects an (SL-specific, e.g., SL-specific) persistent LBT failure, the UE may perform actions (as described in 3GPP TS 38.321). The (SL-specific) consistent LBT failure detection may be per RB set.

[0362] For example, a (SL) UE in RRC_CONNECTED may indicate a (SL-specific) consistent LBT failure to a base station (e.g., a gNB) using a (SL) MAC CE indicating the RB set(s) on which the (SL-specific) consistent LBT failure was detected. For example, a (SL) UE (using Mode 2 resource allocation) may trigger resource reselection and / or resource pool reselection when a (SL-specific) consistent LBT failure occurs. For example, in this case, resources in the failed RB set(s) may be excluded from resource (re)selection until the consistent LBT failure on the RB set(s) is cancelled. For example, the terminal may trigger SL RLF for all PC5-RRC connections when the UE triggers a consistent (SL-specific) LBT failure in all RB sets.

[0363] For example, a lower layer of a MAC entity may perform an LBT procedure. For example, as in 3GPP TS 37.213, a lower layer of a MAC entity may perform an LBT procedure. For example, a lower layer of a MAC entity may perform an LBT procedure if the channel is identified as occupied, and the transmission is not performed by a lower layer of the MAC entity. For example, when a lower layer of a MAC entity performs an LBT procedure before a transmission and the transmission is not performed, a (sidelink) LBT failure indication may be transmitted from the lower layer to the MAC entity. For example, unless otherwise indicated, when a (SL) LBT procedure is performed for a transmission, the action may be performed as disclosed in the present disclosure, regardless of whether an (SL) LBT failure indication is received from a lower layer of the MAC entity. For example, when (SL) LBT is not performed from a lower layer of the MAC entity, an (SL) LBT failure indication may not be received from the lower layer of the MAC entity.

[0364] For example, a (sidelink) LBT failure and / or recovery vehicle may be performed as follows:

[0365] For example, a MAC entity may be configured by RRC with (SL) LBT failure detection and / or recovery procedures. (SL) Consistent LBT failures may be detected on a per-RB-set basis by counting (SL) LBT failure indication(s) for all (SL) transmissions from lower layers to the MAC entity.

[0366] For example, RRC can set the following parameters in the (SL) LBT failure recovery configuration (e.g., (sl-)lbt-FailureRecoveryConfig):

[0367] - (SL) Maximum count of (SL) LBT failure instances for consistent LBT failure detection (e.g., (sl-)lbt-FailureInstanceMaxCount)

[0368] - (SL) LBT failure detection timer for consistent LBT failure detection (e.g., (sl-)lbt-FailureDetectionTimer)

[0369] For example, the following UE variables can be used in a (SL) consistent LBT failure detection procedure:

[0370] - LBT_COUNTER (e.g. SL_LBT_COUNTER) (e.g. RB (set) by): Counter for (SL) LBT failure indications, initially set to 0.

[0371] For example, for a (SL) BWP (e.g., configured with (sl-)lbt-FailureRecoveryConfig), the MAC entity may increment the LBT_COUNTER for the RB set by 1. For example, for a (SL) BWP (e.g., configured with (sl-)lbt-FailureRecoveryConfig), if a (SL) LBT failure indication is received from a lower layer for an RB set of the pool(s) of resources configured in the SL BWP, the MAC entity may increment the LBT_COUNTER for the RB set by 1.

[0372] For example, as illustrated in Figure 20, for a (SL) BWP (e.g., configured with (sl-)lbt-FailureRecoveryConfig), if an (SL) LBT failure indication is received from a lower layer for an RB set of the pool(s) of resources configured in the SL BWP, the MAC entity may increment the LBT_COUNTER for the RB set by 1.

[0373] For example, for a (SL) BWP (e.g., configured with (sl-)lbt-FailureRecoveryConfig), the MAC entity may start or restart (sl-)lbt-FailureDetectionTimer. For example, for a (SL) BWP (e.g., configured with (sl-)lbt-FailureRecoveryConfig), the MAC entity may start or restart (sl-)lbt-FailureDetectionTimer if it is not running. For example, for a (SL) BWP (e.g., configured with (sl-)lbt-FailureRecoveryConfig), if a (SL) LBT failure indication is received from a lower layer for a set of RBs in the pool(s) of resources configured in the SL BWP, the MAC entity may start or restart (sl-)lbt-FailureDetectionTimer.

[0374] For example, as illustrated in Figure 20, for a (SL) BWP (e.g., configured with (sl-)lbt-FailureRecoveryConfig), if an (SL) LBT failure indication is received from a lower layer for an RB set of the pool(s) of resources configured in the SL BWP, the MAC entity may start or restart the (sl-)lbt-FailureDetectionTimer.

[0375] For example, for a (SL) BWP (e.g., configured with (sl-)lbt-FailureRecoveryConfig), the MAC entity can trigger a (SL) consistent LBT failure for a set of RBs in the (SL) BWP. For example, for a (SL) BWP (e.g., configured with (sl-)lbt-FailureRecoveryConfig), if LBT_COUNTER is greater than or equal to (sl-)lbt-FailureInstanceMaxCount, the MAC entity can trigger a (SL) consistent LBT failure for a set of RBs in the (SL) BWP.

[0376] For example, as illustrated in FIG. 20, for a (SL) BWP (e.g., configured with (sl-)lbt-FailureRecoveryConfig), if LBT_COUNTER is greater than or equal to 3, which is (sl-)lbt-FailureInstanceMaxCount, the MAC entity can trigger a (SL) consistent LBT failure for a set of RBs in the (SL) BWP. For example, (sl-)lbt-FailureInstanceMaxCount is not limited to 3. For example, (sl-)lbt-FailureInstanceMaxCount can be set to a value different from 3.

[0377] For example, for a (SL) BWP (e.g. configured with (sl-)lbt-FailureRecoveryConfig), the MAC entity may indicate to RRC for SL (persistent) LBT failure based (sidelink) RLF detection. For example, for a (SL) BWP (e.g. configured with (sl-)lbt-FailureRecoveryConfig), if a consistent LBT failure is triggered in all RB sets of the pool(s) of resources configured in the SL BWP, the MAC entity may indicate to RRC for SL (persistent) LBT failure based (sidelink) RLF detection.

[0378] For example, for a (SL) BWP (e.g., configured with (sl-)lbt-FailureRecoveryConfig), the MAC entity may set LBT_COUNTER to 0 for an RB set. For example, for a (SL) BWP (e.g., configured with (sl-)lbt-FailureRecoveryConfig), if all triggered (SL) consistent LBT failures in the RB set have been canceled, the MAC entity may set LBT_COUNTER to 0 for the RB set. For example, for a (SL) BWP (e.g., configured with (sl-)lbt-FailureRecoveryConfig), if (sl-)lbt-FailureDetectionTimer has expired for the RB set, the MAC entity may set LBT_COUNTER to 0 for the RB set.

[0379] For example, as illustrated in FIG. 20, for a (SL) BWP (e.g., configured with (sl-)lbt-FailureRecoveryConfig), if the (sl-)lbt-FailureDetectionTimer has expired for an RB set, the MAC entity may set the LBT_COUNTER to 0 for the RB set.

[0380] For example, for a (SL) BWP (e.g., configured with (sl-)lbt-FailureRecoveryConfig), the MAC entity may set the LBT counters to 0 for all RB sets. For example, for a (SL) BWP (e.g., configured with (sl-)lbt-FailureRecoveryConfig), if (sl-)lbt-FailureDetectionTimer is reset by upper layers, the MAC entity may set the LBT counters to 0 for all RB sets. For example, for a (SL) BWP (e.g., configured with (sl-)lbt-FailureRecoveryConfig), if (sl-)lbt-FailureInstanceMaxCount is reset by upper layers, the MAC entity may set the LBT counters to 0 for all RB sets.

[0381] For example, the MAC entity may clear the selected (sidelink) grant (if available). For example, if a (sidelink) persistent LBT failure is detected in some RB set(s) of the selected resource pool spanning multiple RB sets for a logical channel, and if a single carrier frequency is configured, the MAC entity may clear the selected (sidelink) grant (if available).

[0382] For example, the MAC entity may trigger TX resource (re)selection. For example, if a (sidelink) persistent LBT failure is detected in some RB set(s) of the selected resource pool spanning multiple RB sets for a logical channel, and if a single carrier frequency is configured, the MAC entity may trigger TX resource (re)selection.

[0383] If guard bands are not established between RB sets, there may be no need to trigger an LBT failure for only the RB set where the LBT occurred. A more comprehensive approach to interference mitigation can be achieved by incrementing the LBT count for other RB sets, not just the RB set where the LBT occurred, based on LBT failure information.

[0384] FIG. 21 illustrates a procedure for LBT with or without a guard band, according to an embodiment of the present disclosure. The embodiment of FIG. 21 can be combined with various embodiments of the present disclosure.

[0385] Referring to FIG. 21, LBT counting may vary depending on the presence or absence of a guard band. For example, if a guard band is present between RB sets, the LBT counter may be incremented for the RB set. For example, if a guard band is present between RB sets, the LBT counter may be incremented for the RB set for which information about an LBT failure has been obtained. For example, if a guard band is not present between RB sets, the LBT counter may also be incremented for the first RB set and a second RB set that is different from the first RB set. For example, if a guard band is present between RB sets, the LBT counter may be incremented for the first RB set for which information about an LBT failure has been obtained, and the LBT counter may also be incremented for the second RB set that is different from the first RB set for which information about an LBT failure has been obtained.

[0386] For example, in an embodiment of the present disclosure, if a guard band is not set between RB sets and an LBT failure counting is increased by 1 in a specific RB set, the UE may also increase a (sidelink) LBT failure counting (e.g., LBT_COUNTER) by 1 in other RB sets (e.g., the other RB sets may be limited to adjacent RB sets around the specific RB set whose LBT failure counting was increased by 1). For example, when this rule is applied, if a (SL) consistent LBT failure occurs in a specific RB set, the UE may not use not only this RB set but also its adjacent RB sets for (sidelink) grant generation or resource reselection. For example, if the granularity of (SL) consistent LBT failure declaration is set to (sidelink) resource pool or (sidelink) BWP, the UE may not perform (sidelink) grant generation or resource reselection operation using the (sidelink) resource pool or (sidelink) BWP to which the adjacent RB set belongs. For example, the LBT counter may be incremented per RB set. For example, the persistent LBT failure may be detected per RB set. For example, the (SL) UE (using Mode 2 resource allocation) may trigger resource reselection and / or resource pool reselection when an (SL-specific) consistent LBT failure occurs. For example, in this case, resources in the failed RB set(s) may be excluded from resource (re)selection until a consistent LBT failure on the RB set(s) is cancelled.For example, the UE may trigger SL RLF for all PC5-RRC connections when the UE triggers a consistent (SL-specific) LBT failure in all RB sets. For example, for a (SL) BWP (e.g., configured with (sl-)lbt-FailureRecoveryConfig), if a consistent LBT failure is triggered in all RB sets of the pool(s) of resources configured in the SL BWP, the MAC entity may indicate to RRC to detect SL (persistent) LBT failure based (sidelink) RLF. For example, the MAC entity may clear the selected (sidelink) grant (if available). For example, if a (sidelink) persistent LBT failure is detected in some RB set(s) of a selected resource pool spanning multiple RB sets for a logical channel, and a single carrier frequency is configured, the MAC entity may clear the selected (sidelink) grant (if available).

[0387] If guard bands are not configured between RB sets, a more comprehensive approach to interference mitigation can be allowed by incrementing LBT counts not only for the RB set where LBT occurred but also for other RB sets based on LBT failure information. This can broaden network performance by preventing potential LBT failures before they degrade service quality, and can ensure a proactive approach to maintaining communication reliability. If guard bands are not configured between RB sets, incrementing LBT counts not only for the RB set where LBT occurred but also for other RB sets based on LBT failure information can enable more dynamic spectrum management, allowing the system to adjust its operation based on real-time information about LBT failures in other RB sets. This can be used as a way to minimize spectrum interference and optimize network performance, especially in dense and complex environments. By counting LBT failures beyond the RB set where they occurred, when guard bands are not established between RB sets, network spectrum-related challenges can be improved. This can help maintain stable connectivity and is particularly important for applications that require high reliability and minimal latency.

[0388] For example, in an embodiment of the present disclosure, when a (sidelink) consistent LBT failure is triggered or declared, the UE may start a timer and may not use the RB set or (sidelink) resource pool where the (sidelink) consistent LBT failure was triggered while the timer is running. For example, if the UE has only one RB set configured, the UE may exceptionally perform LBT check-based (sidelink) consistent LBT Failure MAC CE (e.g., (sidelink) consistent LBT Failure MAC CE) (e.g., or PSCC / PSSCH or PSFCH) transmission using the RB set or (sidelink) resource pool where the (SL) consistent LBT failure occurred for transmission of the (sidelink) consistent LBT Failure MAC CE (e.g., (sidelink) consistent LBT Failure MAC CE) (e.g., or PSCC / PSSCH or PSFCH) to the counterpart UE.

[0389] For example, a terminal's (sidelink) consistent LBT failure MAC CE transmission (e.g., (sidelink) consistent LBT Failure MAC CE) may be triggered only if there is at least one RB set (e.g., or (sidelink) resource pool) in which no (sidelink) (consistent) LBT failure occurred.

[0390] For example, in an embodiment of the present disclosure, when UE#A selects a newly created (SL) grant-related resource according to (some) of the rules below, considering its other (SL) grant-related resources (e.g., and / or CPE configuration values) or other UE#B's reserved resources (e.g., and / or CPE configuration values), only data / messages having a priority (e.g., CAPC, (L1) PRIORITY) associated with the selected CPE length value based on Rule A are selected in the LCP procedure and configured to be transmitted through the new (SL) grant-related resource, and / or only data / messages having a priority (e.g., CAPC, (L1) PRIORITY) associated with its other (SL) grant-related resources (e.g., and / or other UE#B's reserved resources) on Rule B are selected in the LCP procedure (e.g., its other (SL) grant-related resources) (e.g., when (preferentially) selecting a candidate resource on a slot adjacent to and in front of its own other (SL) grant related resources (e.g., and / or other UE#B's reserved resources)) (e.g., only data / messages with and / or lower or equal values ​​are selected in the LCP procedure (e.g., when (preferentially) selecting a candidate resource on a slot adjacent to and behind its own other (SL) grant related resources (e.g., and / or other UE#B's reserved resources))) and transmitted through the new (SL) grant related resources.

[0391] For example, Rule A) Selectable CPE length (candidate) values ​​are limited based on priorities (e.g., CAPC, (L1) PRIORITY), and if UE#A selects a resource (for a newly created (SL) grant) that is FDM'd with (e.g., and / or overlaps (e.g., in time and / or packet resource domain)) the reserved resource of UE#B, then the same CPE length value related to the reserved resource of UE#B is applied. This can increase resource utilization / efficiency, for example, from a system perspective.

[0392] For example, Rule B) UE#A (preferentially) selects a candidate resource (for a newly created (SL) grant) in a slot adjacent to (e.g., and / or after) its other (SL) grant-related resources (e.g., and / or reserved resources of another UE#B). This can reduce LBT overhead, for example, by enabling TX burst structure (e.g., between different TB transmissions).

[0393] For example, a transmitting terminal performing (sidelink) communication in an unlicensed band (sl-U) can perform an LBT operation to occupy a channel in the unlicensed band. For example, if the LBT is successful, the terminal can transmit packets in the occupied channel. For example, if the LBT fails (for example, if the terminal detects that the channel is busy as a result of sensing during the sensing slot period), the (sidelink) transmission cannot be performed because the channel in the unlicensed band was not occupied. 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 physical layer.

[0394] For example, the terminal may receive the following parameters for (SL) LBT failure management from the base station and perform (SL) LBT failure recovery or (SL) LBT failure declaration operations.

[0395] - (sl-)lbt-failureInstanceMaxCount: When the terminal detects an (SL) LBT failure, it increments the LBT_COUNTER (e.g., SL_LBT_COUNTER) by 1, and can declare an (SL) LBT failure when it detects (sl-)lbt-failureInstanceMaxCount (SL) LBT failures before (sl-)lbt-failureDetectionTimer expires.

[0396] - (sl-)lbt-failureDetectionTimer: A timer that starts when (SL) LBT failure is detected. The (SL) LBT failure recovery process can be performed while the timer is running.

[0397] For example, when the MAC layer of a transmitting terminal receives a (SL) LBT failure event from the physical layer (i.e., when the terminal detects an (SL) LBT failure), the MAC layer may start the (sl-)lbt-failureDetectionTimer timer and simultaneously increase the LBT_COUNTER (e.g., SL_LBT_COUNTER) by 1. For example, the (SL) LBT recovery process may be performed during the operation of the (sl-)lbt-failureDetectionTimer timer. For example, when the terminal detects an (SL) LBT failure again during the operation of the (sl-)lbt-failureDetectionTimer timer, the terminal may increase the LBT_COUNTER (e.g., SL_LBT_COUNTER) by 1. For example, if the LBT_COUNTER (e.g., SL_LBT_COUNTER) incremented due to (SL) LBT detection does not reach the threshold number ((sl-)lbt-failureInstanceMaxCount) before the (sl-)lbt-failureDetectionTimer timer expires, the terminal considers the (SL) LBT failure to have been recovered and can continue to perform normal (sidelink) communication using the (sidelink) grant in use.

[0398] For example, a consistent (SL) LBT failure can be declared if the LBT_COUNTER (e.g., SL_LBT_COUNTER) incremented due to (SL) LBT failure detection reaches a threshold number of times ((sl-)lbt-failureInstanceMaxCount) before the (sl-)lbt-failureDetectionTimer timer expires. For example, the MAC layer can declare a consistent (SL) LBT failure per (sidelink) resource pool or per RB (resource block) set. For example, if a UE performs LBT for (SL) data transmission in the currently used (sidelink) resource pool or RB set and a consistent (SL) LBT failure is reached, the UE may switch to another (sidelink) resource pool or another RB set and re-perform LBT for (SL) data transmission instead of declaring a (sidelink) radio link failure (RLF). For example, if a UE experiences consistent (SL) LBT failures for all (sidelink) resource pools or all RB sets, the UE may declare an (SL) RLF in the (sidelink) unlicensed band.

[0399] For example, in an embodiment of the present disclosure, when a MAC entity of a terminal receives an (SL) LBT failure indication from a physical layer (e.g., a one-shot (SL) LBT failure or a threshold (the threshold value may be set to a value smaller than a threshold for declaring a consistent (SL) LBT failure, which may be set by the base station or may be set in advance)), the terminal may switch to another RB set having idle resources (e.g., a process of performing channel sensing to search for an RB set having idle resources) and re-perform an LBT operation for (sidelink) data transmission in the switched RB set.

[0400] For example, a transmitting terminal may be prevented from using a (sidelink) resource pool or RB set for a period of time in which a consistent LBT failure has occurred (e.g., by considering it as a de-prioritized (sidelink) resource pool or de-prioritized RB set). For example, if a transmitting terminal declares a consistent LBT failure, the (sidelink) resource pool or RB set in which the consistent LBT failure occurred may not be used for a certain period of time and may be used again after a certain period of time (e.g., or expired) (e.g., after a timer expires, the transmitting terminal may perform resource selection again using the (sidelink) resource pool or RB set in which the previous consistent LBT failure occurred). For example, the time period for which the (sidelink) resource pool or RB set in which the consistent LBT failure occurred may not be used (e.g., a timer for (SL) resource pool / RB set de-prioritization) may be configured by the base station to the terminal (via an RRC message) or may be pre-configured (e.g., pre-configuration).For example, a time period (e.g., a timer for (SL) resource pool / RB set de-prioritization) can be set to prevent the (sidelink) resource pool or RB set from being used when a consistent LBT failure occurs between terminals during PC5 RRC reconfiguration. For example, the time after which a consistent LBT failure will cause the (sidelink) resource pool or RB set to become unusable (e.g., a timer for (SL) resource pool de-prioritization) can be configured per (sidelink) logical channel or PQI (PC5 QoS Identifier) ​​or per (sidelink) resource pool or RB set or per (sidelink) BWP, per QoS profile or per destination layer-2 ID or per source layer-2 ID / destination layer-2 ID pair (e.g., Source Layer-2 ID / Destination Layer-2 ID pair) or per (sl-)CAPC or per Sidelink priority. For example, in an embodiment of the present disclosure, if a transmitting terminal declares a consistent LBT failure, the transmitting terminal may perform an LBT operation to reuse the (sidelink) resource pool or RB set after a corresponding period of time without using the (sidelink) resource pool or RB set in which the consistent LBT failure occurred.For example, LBT (performed at this time) can be performed by a transmitting terminal to check whether a (sidelink) resource pool or RB set can be reused even if there is no (sidelink) data to transmit. For example, when a transmitting terminal performs LBT (e.g., type 1 LBT or type 2A LBT or type 2B LBT or type 2C LBT) on a (sidelink) resource pool or RB set where a consistent LBT failure has occurred, and detects LBT success as many times as a threshold (e.g., threshold N = can be set to a value greater than or equal to 1. For example, threshold N can be set per (sidelink) logical channel or PQI (PC5 QoS Identifier) ​​or per (sidelink) resource pool or RB set or per QoS profile or per destination layer-2 ID), the transmitting terminal can perform (SL) data transmission by reusing the corresponding (sidelink) resource pool or RB set.

[0401] For example, in an embodiment of the present disclosure, a transmitting terminal may report to a base station (e.g., a sidelink resource pool index) information in which a consistent LBT failure has occurred or RB set information in which a consistent LBT failure has occurred (e.g., an RB set index). For example, when a transmitting terminal reports to the base station (sidelink) resource pool information (e.g., sidelink resource pool index) where a consistent LBT failure occurred or RB set information (e.g., RB set index) where a consistent LBT failure occurred, the transmitting terminal may also report to the base station (sidelink) resource pool information (e.g., sidelink resource pool index) where the switching occurred or RB set information (e.g., RB set index) where the switching occurred.

[0402] For example, in an embodiment of the present disclosure, a transmitting terminal may start a timer (e.g., a timer for (SL) resource pool / RB set de-prioritization) (e.g., a timer for (SL) resource pool / RB set de-prioritization) if it declares a consistent LBT failure per RB set, per (sidelink) resource pool, or per (sidelink) BWP. For example, a transmitting terminal may start a timer (e.g., a timer for (SL) resource pool / RB set de-prioritization) if it declares a consistent LBT failure for all configured (e.g., or in use) RB sets, or all configured (e.g., or in use) (sidelink) resource pools, or all configured (e.g., or in use) (sidelink) BWPs.

[0403] For example, in an embodiment of the present disclosure, even if a transmitting terminal declares a consistent LBT failure in (all) RB sets or (all) (sidelink) resource pools or (all) (sidelink) BWPs, the transmitting terminal may declare a (sidelink) RLF for all established unicast links (e.g., or all established PC5 RRC connections) after a timer (e.g., a timer for (SL) resource pool / RB set de-prioritization) has expired and terminate all established (sidelink) unicast links or all established PC5 RRC connections.

[0404] For example, in an embodiment of the present disclosure, the transmitting terminal may pending the use of the selected (e.g., or in-use) (sidelink) grant without releasing it while a timer (e.g., a timer for (SL) resource pool / RB set de-prioritization) is running, or may release the selected (e.g., or in-use) (sidelink) grant.

[0405] For example, in an embodiment of the present disclosure, if a transmitting terminal receives (sidelink) data (e.g., PSCCH / PSSCH) from a counterpart terminal and the CBR is below a threshold (e.g., or the CBR at the time of a consistent LBT failure declaration is below a preset offset), the transmitting terminal may reuse a pending RB set (e.g., or (sidelink) resource pool).

[0406] For example, embodiments of the present disclosure may be solutions applicable and extendable to all states in which a terminal is in an RRC CONNECTED state with a base station, a state in which a terminal is in an RRC idle state with a base station, a state in which a terminal is in an RRC INACTIVE state with a base station, and a state in which a terminal is out of coverage with a base station (e.g., out of coverage).

[0407] For example, in an embodiment of the present disclosure, when a (sidelink) LBT failure reaches a preset threshold number of times and triggers a (sidelink) consistent LBT failure, the terminal may cancel the triggered (sidelink) consistent LBT failure and perform normal (sidelink) communication in the (sidelink) unlicensed band if the following conditions are satisfied.

[0408] For example, 1) if the UE receives a new mode 1 (sidelink) grant or a new RB set / resource pool (related to a set of resource blocks) that does not have consistent LBT failure (e.g., at least one or a number greater than a preset threshold) due to success in decoding Uu LBT (e.g., uplink data from the UE to the base station or uplink MAC CE (e.g., MAC CE for reporting (sidelink) consistent LBT failure) or channel access procedure for transmitting PUCCH or RRC message) or success in decoding an uplink message from the UE to the base station (e.g., uplink data from the UE to the base station or uplink MAC CE (e.g., MAC CE for indicating (sidelink) consistent LBT failure to the base station) or PUCCH or RRC message)

[0409] For example, 2) if the terminal successfully decode Uu LBT (e.g., uplink data from the terminal to the base station or uplink MAC CE (e.g., MAC CE for reporting (sidelink) consistent LBT failure) or channel access procedure for transmitting PUCCH or RRC message) or the base station successfully decode the terminal's uplink message (e.g., uplink data from the terminal to the base station or uplink MAC CE (e.g., MAC CE for indicating (sidelink) consistent LBT failure to the base station) or PUCCH or RRC message), the terminal is granted a new mode 1 (sidelink) grant or a new RB set / resource pool related to the RB set / resource pool where consistent LBT occurred (SL) and is set to mode 1 or mode 2 (Side Link) If the grant is cleared

[0410] For example, 3) if the terminal successfully decode Uu LBT (e.g., uplink data from the terminal to the base station or uplink MAC CE (e.g., MAC CE for reporting (sidelink) consistent LBT failure) or channel access procedure for transmitting PUCCH or RRC message) or the base station successfully decode the terminal's uplink message (e.g., uplink data from the terminal to the base station or uplink MAC CE (e.g., MAC CE for indicating (sidelink) consistent LBT failure to the base station) or PUCCH or RRC message), the terminal receives a new mode 1 (sidelink) grant or a new RB set / resource pool related to the RB set / resource pool where consistent LBT occurred (SL) and sets the resource block set / resource pool related to the RB set / resource pool where consistent LBT occurred. 2. When clearing the (sidelink) grant or flushing the HARQ Buffer related to MAC PDU transmission of the Mode 1 or Mode 2 (sidelink) grant related to the RB set / resource pool where consistent LBT occurred (SL).

[0411] For example, 4) the terminal may cancel the triggered (sidelink) consistent LBT failure if it receives a Mode 1 grant based on a (sidelink) resource pool or a (sidelink) resource block set (e.g., at least one or more than a preset threshold number) in which the (SL) consistent LBT failure did not occur by transmitting a Uu MAC CE for reporting the (SL) consistent LBT failure to the base station.

[0412] For example, 5) when a (sidelink) consistent LBT failure is triggered, the terminal may cancel the triggered (sidelink) consistent LBT failure by transmitting a Uu MAC CE to the base station for reporting the (SL) consistent LBT failure to the base station, and receiving a reset or reallocation from the base station of a (sidelink) resource pool or a set of (sidelink) resource blocks (at least one or more than a preset threshold number) in which the (SL) consistent LBT failure did not occur.

[0413] For example, if (SL) RLF occurs for a PC5 RRC connection (e.g., or a unicast link) where a (sidelink) consistent LBT failure occurs (e.g., or triggered).

[0414] For example, 7) (Sidelink) If a MAC reset is triggered for a PC5 RRC connection (e.g., a unicast link) or a groupcast session / broadcast session where a consistent LBT failure has occurred (e.g., triggered).

[0415] For example, 8) (Sidelink) If a consistent LBT failure occurs (e.g., or triggered), the (SL) BWP is deactivated.

[0416] For example, 9) in multi-carrier operation, if carrier reselection is triggered for a (sidelink) carrier that has experienced (or is triggered by) a (sidelink) persistent LBT failure.

[0417] For example, 10) In the (sidelink) FR2 operation, if a beam failure recovery procedure is triggered for a beam-related resource where a (sidelink) consistent LBT failure has occurred (e.g., or triggered) (e.g., or the beam failure recovery procedure has failed or the beam failure recovery procedure has succeeded).

[0418] For example, 11) If a PC5 RRC Reconfiguration procedure is triggered for a PC5 RRC connection (e.g., or a unicast link) on which a (sidelink) consistent LBT failure has occurred (e.g., or triggered) (e.g., or reconfiguration of a PC5 RRC connection on which a (sidelink) consistent LBT failure has occurred has been completed).

[0419] For example, 12) if a (sidelink) RB set or (sidelink) resource pool or (SL) BWP associated with a triggered (sidelink) consistent LBT failure is replaced with a new (sidelink) RB set (e.g., a (sidelink) RB set that has not experienced a (consistent) LBT failure) or (sidelink) resource pool (e.g., a (sidelink) resource pool that has not experienced a (consistent) LBT failure) or (sidelink) BWP (e.g., a (SL) BWP that has not experienced a (consistent) LBT failure).

[0420] For example, if a resource reselection procedure is triggered for a (sidelink) resource associated with a triggered (sidelink) consistent LBT failure (e.g., or if the resource reselection procedure is completed).

[0421] For example, 14) When a resource re-selection procedure is triggered for a (sidelink) resource associated with a triggered (sidelink) consistent LBT failure (e.g., by Re-evaluation or pre-emption or congestion control or uplink / (sidelink) prioritization, etc.) (e.g., or when a resource re-selection procedure is completed)

[0422] For example, if the configuration information for recovery of (sidelink) consistent LBT failure (e.g., (sl_)lbt-failureInstanceMaxCount, (sl_)lbt-failureDetectionTimer) is reset.

[0423] For example, 16) If the terminal successfully completes transmission of an (SL) consistent LBT failure MAC CE (e.g., (SL) consistent LBT failure MAC CE) for (SL) consistent LBT failure to a pre-configured number (e.g., 1) or more of peer UEs, or to a peer UE involved in data transmission above (e.g., below) a pre-configured (SL) CAPC priority or (sidelink) priority or L1 priority threshold level, the terminal may cancel the triggered (SL) consistent LBT failure procedure.

[0424] For example, 17) The UE may transmit (SL) consistent LBT failure MAC CEs (e.g., (SL) consistent LBT failure MAC CEs) only to a pre-configured number (e.g., 1) or more of peer UEs, or to peer UEs involved in data transmission above (e.g., below) a pre-configured (SL) CAPC priority or (sidelink) priority or L1 priority threshold level. For example, the UE may cancel a triggered (SL) consistent LBT failure procedure only if it has successfully transmitted (SL) consistent LBT failure MAC CEs (e.g., (SL) consistent LBT failure MAC CEs) to all of the corresponding peer UEs, if this rule applies.

[0425] For example, the present disclosure may propose the following (sidelink) unlicensed band operation.

[0426] For example, if the base station successfully decodes an uplink message of the terminal (e.g., an uplink MAC CE (e.g., a MAC CE indicating to the base station that (sidelink) consistent LBT failure has occurred), it can configure the terminal with a new Mode 1 (sidelink) grant or a new RB set / resource pool for a set of resource blocks (at least one or a number greater than a preset threshold) for which (sidelink) consistent LBT failure has not occurred.

[0427] For example, when a terminal transmits an uplink message (e.g., an uplink MAC CE (e.g., a MAC CE indicating (sidelink) consistent LBT failure to the base station) to the base station and receives from the base station a new mode 1 (sidelink) grant or a new RB set / resource pool related to a set of resource blocks (at least one or a number greater than a preset threshold) for which (sidelink) consistent LBT failure has not occurred, the (SL) can clear the mode 1 or mode 2 (sidelink) grant related to the RB set / resource pool for which consistent LBT has occurred.

[0428] For example, when a terminal transmits an uplink message (e.g., an uplink MAC CE (e.g., a MAC CE indicating (sidelink) consistent LBT failure to the base station) to the base station and receives from the base station a new mode 1 (sidelink) grant or a new RB set / resource pool associated with a set of resource blocks (at least one or a number greater than a preset threshold) for which (sidelink) consistent LBT failure has not occurred, the terminal may clear the mode 1 or mode 2 (sidelink) grant associated with the RB set / resource pool for which (SL) consistent LBT has occurred and / or flush the HARQ Buffer associated with the MAC PDU transmission of the mode 1 or mode 2 (sidelink) grant associated with the RB set / resource pool for which (SL) consistent LBT has occurred.

[0429] For example, if a terminal transmits an uplink message (e.g., an uplink MAC CE (e.g., a MAC CE indicating (sidelink) consistent LBT failure to the base station)) to the base station and receives from the base station a new mode 1 (sidelink) grant or a new RB set / resource pool related to a set of (at least one or a number greater than a preset threshold) resource blocks in which (sidelink) consistent LBT failure did not occur, the triggered (SL) consistent LBT failure can be canceled and normal (sidelink) communication can be performed in the (sidelink) unlicensed band.

[0430] For example, in an embodiment of the present disclosure, if a terminal declares a (sidelink) consistent LBT failure, the terminal may not use the (sidelink) resource pool or RB set in which the (sidelink) consistent LBT failure occurred for a certain period of time, and may reuse the (sidelink) resource pool or RB set after a certain period of time (e.g., or after a timer expires) has elapsed (e.g., the transmitting terminal may perform resource selection operation again using the (sidelink) resource pool or RB set in which the previous (sidelink) consistent LBT failure occurred). For example, the time period for which the (sidelink) resource pool or RB set in which the (sidelink) consistent LBT failure occurred is de-prioritized (e.g., a timer for (SL) resource pool / RB set de-prioritization) may be set by the base station to the terminal (via an RRC message) or may be pre-configured.For example, if a terminal (e.g., a mode 2 terminal) fails to transmit a Uu consistent LBT failure MAC CE (e.g., Uu consistent LBT failure MAC CE) to the base station for reporting a (sidelink) consistent LBT failure due to a Uu LBT failure, or if the Uu LBT of the Uu consistent LBT failure MAC CE (e.g., Uu consistent LBT failure MAC CE) for reporting a (sidelink) consistent LBT failure is successful and the corresponding MAC CE is successfully transmitted but no response is received from the base station, the terminal does not use the resources of the resource block (RB) set where the (sidelink) consistent LBT failure occurred or the resources belonging to the resource pool where the (sidelink) consistent LBT failure occurred while the timer is running, and after the timer expires, the terminal transmits the resources where the (sidelink) consistent LBT failure occurred. It is possible to enable the use of resources belonging to a set of blocks (resource blocks) (RBs) or a pool of resources that have experienced a consistent LBT failure (side link).For example, if a terminal (e.g., a mode 1 terminal) fails to transmit a Uu consistent LBT failure MAC CE (e.g., Uu consistent LBT failure MAC CE) to the base station for reporting a (sidelink) consistent LBT failure due to a Uu LBT failure, or if the Uu LBT of the Uu consistent LBT failure MAC CE (e.g., Uu consistent LBT failure MAC CE) for reporting a (sidelink) consistent LBT failure is successful and the corresponding MAC CE is successfully transmitted but no response is received from the base station, then the terminal (e.g., a mode 1 terminal) does not use the (sidelink) grant of the resource block (RB) set in which the (sidelink) consistent LBT failure occurred or the (sidelink) grant of the resource pool in which the (sidelink) consistent LBT failure occurred while the timer is running, and then after the timer expires, the terminal (e.g., a mode 1 terminal) transmits a (sidelink) It is possible to use a (sidelink) grant of a set of resource blocks (RBs) that have experienced consistent LBT failures or a (sidelink) grant of a resource pool that has experienced consistent LBT failures.For example, if the terminal fails to transmit a Uu consistent LBT failure MAC CE (e.g., Uu consistent LBT failure MAC CE) to the base station for reporting a (sidelink) consistent LBT failure due to a Uu LBT failure, or if the Uu LBT of the Uu consistent LBT failure MAC CE (e.g., Uu consistent LBT failure MAC CE) for reporting a (sidelink) consistent LBT failure is successful and the corresponding MAC CE is successfully transmitted but no response is received from the base station, the triggered (sidelink) consistent LBT failure may not be canceled while the timer is running, but the triggered (sidelink) consistent LBT failure may be canceled when the timer expires. For example, when the above rule is applied, it can be interpreted that the terminal clears the remaining retransmission resources related to the (sidelink) grant, or the terminal transmits an ACK (e.g., or NACK) on the PUCCH related to the (sidelink) grant. The operation of the present disclosure can be applied to all (sidelink) unicast / groupcast / broadcast operations.

[0431] In embodiments of the present disclosure, “channel” may be replaced with “carrier” or “a set of resource blocks of a specific carrier” or “band”.

[0432] In the present disclosure, multi-carrier can be extended to be interpreted as carrier aggregation (CA).

[0433] In order to ensure HARQ feedback enabled MAC PDU transmission in (sidelink) multi-carrier operation, the base station may expect the terminal to configure PSFCH resources in an exceptional pool (e.g., a normal TX pool or a normal RX pool) on at least one (sidelink) carrier / SL BWP / SL HARQ entity among multiple (sidelink) carriers / SL BWP / SL HARQ entities to which the same unicast service or the same source layer-2 ID / destination layer-2 ID pair (e.g., or the same groupcast / broadcast service or the same destination layer-2 ID) are mapped. The present disclosure is not limited thereto.

[0434] When a base station forms a unicast session, groupcast, or broadcast session that performs HARQ feedback enabled MAC PDU transmission, the base station may restrict the terminal to include at least one carrier that includes an exceptional pool (e.g., a normal TX pool or a normal RX pool) in which the PSFCH resource is set. The present disclosure is not limited thereto.

[0435] When a terminal forms a unicast session, groupcast, or broadcast session that performs HARQ feedback enabled MAC PDU transmission, it may be restricted to include at least one carrier that includes an exceptional pool (e.g., a normal TX pool or a normal RX pool) in which PSFCH resources are configured. The present disclosure is not limited thereto.

[0436] In the present disclosure, the CBR threshold associated with a sidelink carrier / SL BWP / SL HARQ entity can be set per priority, per QoS profile (e.g., PDB, reliability), per SL Radio Bearer, or per logical channel.

[0437] In the present disclosure, a (sidelink) carrier can be extended to be interpreted as a (sidelink) BWP or a (sidelink) HARQ entity.

[0438] In embodiments of the present disclosure, “carrier” may be replaced with “band” or “resource block set of a specific carrier” or “resource pool set of a specific carrier” or “channel”.

[0439] In embodiments of the present disclosure, the beam management operation may be interpreted as being replaced with beam selection or spatial filter selection or beam pairing or spatial filter pairing or beam failure recovery (BFR) or spatial filter recovery or beam sweeping or spatial filter sweeping or beam switching or spatial filter sweeping or reference signal (RS) resource measurement or reference signal (RS) resource measurement report operation or beam report or spatial filter report.

[0440] In embodiments of the present disclosure, the beam may be interpreted as being replaced by an RS or RS resource or a spatial filter resource.

[0441] In the embodiments of the present disclosure, RS may be interpreted as being replaced with an RS resource or a spatial filter resource.

[0442] In the embodiments of the present disclosure, the transmitting terminal may be interpreted as a terminal transmitting a beam, a terminal transmitting a beam RS, a terminal transmitting a beam RS resource, etc.

[0443] In the embodiment of the present disclosure, the receiving terminal may be interpreted as a terminal that receives a beam, a terminal that receives a beam RS, a terminal that receives a beam RS resource, etc.

[0444] In an embodiment of the present disclosure, the transmission beam or reception beam information transmitted and received by the terminal may be interpreted as being replaced with resource information of a reference signal (RS) associated with the transmission beam and resource information of a reference signal (RS) associated with the reception beam.

[0445] In an embodiment of the present disclosure, the DCR (direct communication request) message and / or the DCA (direct communication accept) message may be interpreted as being replaced with a PC5-S (sidelink) DCR message and / or a PC5-S (sidelink) DCA message.

[0446] Although the embodiments of the present disclosure have exemplified (SL) CSI-RS as an RS for beam management, the present disclosure is not limited thereto. The proposed operations of the present disclosure can be equally extended and applied to cases where a reference signal (RS) other than (SL) CSI-RS (e.g., (sidelink) SSB) is used as an RS for beam management.

[0447] Although the embodiments of the present disclosure have exemplified RSRP as an RS measurement for beam management, the present disclosure is not limited thereto. The proposed operations of the present disclosure can be equally extended and applied to other measurement operations (e.g., RSSI (received signal strength indicator) measurement, etc.) as RS measurement for beam management.

[0448] In embodiments of the present disclosure, spatial settings and / or transmission configuration indicator (TCI) information and / or quasi-colocation (QCL) information and / or beams may refer to each other and / or may be interpreted as being replaced with beam-related information, beam direction, spatial domain transmission filter and / or spatial domain reception filter. For example, the spatial domain transmission filter may be a spatial domain TX filter. For example, the spatial domain reception filter may be a spatial domain RX filter.

[0449] In embodiments of the present disclosure, the beam may be interpreted as being replaced by a spatial filter.

[0450] In embodiments of the present disclosure, the transmit / transmit beam may be interpreted as being replaced by a spatial transmission (TX) filter or a spatial domain transmission (TX) filter.

[0451] In embodiments of the present disclosure, a beam may be interpreted as a transmit beam or a receive beam or a spatial filter or a spatial transmission (TX) filter or a spatial domain transmission (TX) filter or a spatial reception (RX) filter or a spatial domain reception (RX) filter.

[0452] In embodiments of the present disclosure, the reception beam may be interpreted as being replaced by a spatial reception (RX) filter or a spatial domain reception (RX) filter.

[0453] In an embodiment of the present disclosure, the fact that the spatial setting information (or beam information) for transmission is the same may mean that the spatial domain TX filter of the terminal is the same for two different transmission signals. In an embodiment of the present disclosure, the fact that the spatial setting information (or beam information) for reception is the same may mean that the two different reception signals are in a QCL 'TypeD' relationship and / or use the same spatial RX parameters.

[0454] 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 (and / or independently and / or differently) according to the SL-CAPC (Channel Access Priority Class). 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 (and / or independently and / or differently) according to the SL-LBT type (e.g., Type 1 LBT, Type 2A LBT, Type 2B LTB, or 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) can be set specifically (and / or independently and / or differently) according to the FBE (Frame Based LBT). 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 (and / or independently and / or differently) depending on whether LBE (Load Based LBT) is applied.

[0455] For example, whether (some) of the proposed schemes / rules of the present disclosure are applied and / or related parameters (e.g., thresholds) may be specifically (or differently or independently) set depending on whether LBT succeeds / fails, LBT-related energy detection levels, sidelink channels (PSCCH / PSSCH, PSFCH, SL-SSB (or S-SSB)), whether MCSt (Multi-Consecutive Slot Transmission) is applied, whether multi-PSFCH occasions are applied, resource order / location for setting MCSt, whether multiple starting points are set within one slot, whether the 1st starting point (or 2nd starting point) is applied, etc.

[0456] Whether (some) of the proposed methods / rules of the present disclosure are applied and / or related parameters (e.g., thresholds) may be specifically (or differently or independently) set according to whether LBT is successful / failure, LBT-related energy detection level, sidelink channel (PSCCH / PSSCH, PSFCH, SL-SSB), whether MCSt (multi-consecutive slot transmission) is applied, whether multi-PSFCH (multi-PSFCH) occasion is applied, resource order / location constituting MCSt, whether multiple starting points are set within one slot, whether 1st starting point (or 2nd starting point) is applied, etc.

[0457] For example, the present disclosure (e.g., whether (some) of the proposed methods / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds)) can be specifically (and / or independently and / or differently) set according to the resource pool. For example, the present disclosure (e.g., whether (some) of the proposed methods / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds)) can be specifically (and / or independently and / or differently) set according to the congestion level. For example, the present disclosure (e.g., whether (some) of the proposed methods / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds)) can be specifically (and / or independently and / or differently) set according to the priority of the service. For example, the present disclosure (e.g., whether (some) of the proposed methods / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds)) can be specifically (and / or independently and / or differently) set according to the type of service. For example, the present disclosure (e.g., whether (some) of the proposed methods / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds)) can be specifically (and / or independently and / or differently) set according to QoS requirements (e.g., latency, reliability). For example, the present disclosure (e.g., whether (some) of the proposed methods / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds)) can be specifically (and / or independently and / or differently) set according to PQI (5QI (5G QoS identifier) ​​for PC5). For example, the present disclosure (e.g., whether (some) of the proposed methods / rules of the present disclosure are applicable and / or the associated parameters (e.g., thresholds)) may be set specifically (and / or independently and / or differently) depending on the traffic type (e.g., periodic generation and / or aperiodic generation).For example, the present disclosure (e.g., whether (some) of the proposed schemes / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds)) can be specifically (and / or independently and / or differently) configured according to a (SL) transmission resource allocation mode (e.g., mode 1 and / or mode 2). For example, the present disclosure (e.g., whether (some) of the proposed schemes / rules of the present disclosure are applicable and / or related parameters (e.g., thresholds)) can be specifically (and / or independently and / or differently) configured according to 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).

[0458] For example, the present disclosure may determine whether a proposed rule is applied (and / or a related parameter setting value) whether PUCCH configuration is supported (e.g., when PUCCH resources are configured or when PUCCH resources are not configured), resource pool (e.g., resource pool with PSFCH configured, resource pool without PSFCH configured), service / packet type (and / or priority), QoS profile or QoS requirement (e.g., URLLC / EMBB traffic, reliability, latency), PQI, PFI, cast type (e.g., unicast, groupcast, broadcast, (resource pool) congestion level (e.g., CBR), SL HARQ feedback scheme (e.g., NACK only feedback, ACK / NACK feedback), HARQ feedback enabled MAC PDU. In case of transmitting (and / or HARQ feedback disabled MAC PDU), whether to set PUCCH-based SL HARQ feedback reporting operation, in case of (non)performing (or resource reselection-based) pre-emption (and / or re-evaluation), (L2 or L1) (source and / or destination) identifier, (L2 or L1) (combination of source layer ID and destination layer ID) identifier, (L2 or L1) (combination of a pair of source layer ID and destination layer ID and cast type) identifier,For at least one of a direction of a pair of source layer ID and destination layer ID, a PC5 RRC connection / link, a case of SL DRX (non)performance (or support), an SL mode type (resource allocation mode 1, resource allocation mode 2), (non)periodic resource reservation performance, a Tx profile (e.g., a Tx profile indicating that the service supports (sidelink) DRX operation, a Tx profile indicating that the service does not need to support (sidelink) DRX operation), it can be configured specifically (and / or independently and / or differently).

[0459] For example, 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.

[0460] FIG. 22 illustrates a method for a first device to perform wireless communication according to an embodiment of the present disclosure. The embodiment of FIG. 22 may be combined with various embodiments of the present disclosure.

[0461] Referring to FIG. 22, in step S2210, the first device can obtain information related to a maximum count for LBT (listen before talk) failure detection. In step S220, the first device can detect a persistent LBT failure based on the LBT counter being greater than or equal to the maximum count for LBT failure detection. For example, the first LBT counter can be increased by 1 for the first RB (resource block) set based on the information regarding the LBT failure for the first RB set being obtained. For example, the second LBT counter can be increased by 1 for the second RB set, which is a different RB set from the first RB set, based on the first LBT counter being increased by 1 for the first RB set and based on the fact that a guard band is not set between RB sets.

[0462] For example, the LBT counter may be incremented per RB set. For example, the persistent LBT failure may be detected per RB set.

[0463] For example, a first persistent LBT may be detected for the first RB set based on the first LBT counter being greater than or equal to a maximum count for LBT failure detection. For example, a second persistent LBT may be detected for the second RB set based on the second LBT counter being greater than or equal to a maximum count for LBT failure detection.

[0464] For example, the second RB set may be an RB set adjacent to the first RB set.

[0465] For example, resources in the first RB set in which the first persistent LBT failure is detected and the second RB set in which the second persistent LBT failure is detected may be excluded from resource reselection.

[0466] For example, resource reselection may be triggered on resources excluding resources in the first RB set in which the first persistent LBT failure is detected and the second RB set in which the second persistent LBT failure is detected.

[0467] For example, grants associated with a first set of RBs in which the first persistent LBT failure is detected and a second set of RBs in which the second persistent LBT failure is detected may be cleared.

[0468] For example, a radio link failure (RLF) can be detected based on the above persistent LBT failure being detected for all RB sets.

[0469] For example, based on the detection of the persistent LBT failure on a resource pool basis, resources in a first resource pool including a first set of RBs in which the first persistent LBT failure is detected and a second resource pool including a second set of RBs in which the second persistent LBT failure is detected may be excluded from resource reselection.

[0470] For example, based on the detection of the persistent LBT failure on a resource pool basis, grants associated with a first resource pool including a first set of RBs in which the first persistent LBT failure is detected and a second resource pool including a second set of RBs in which the second persistent LBT failure is detected may be cleared.

[0471] For example, based on the detection of the persistent LBT failure in units of bandwidth parts (BWPs), resources in a first BWP including a first set of RBs in which the first persistent LBT failure is detected and a BWP including a second RB in which the second persistent LBT failure is detected may be excluded from resource selection or reselection.

[0472] For example, based on the detection of the persistent LBT failure on a BWP basis, a grant associated with a first BWP including a first set of RBs in which the first persistent LBT failure is detected and a BWP including a second set of RBs in which the second persistent LBT failure is detected may be cleared.

[0473] For example, the above persistent LBT failure may be a sidelink persistent LBT failure.

[0474] 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 obtain information related to a maximum count for detecting listen before talk (LBT) failure. Then, the processor (102) of the first device (100) can detect a persistent LBT failure based on the LBT counter being greater than or equal to the maximum count for detecting LBT failure. For example, the first LBT counter can be increased by 1 for the first RB (resource block) set based on the information regarding the LBT failure for the first RB set being obtained. For example, the second LBT counter can be increased by 1 for the second RB set, which is a different RB set from the first RB set, based on the first LBT counter being increased by 1 for the first RB set and based on the fact that a guard band is not set between the RB sets.

[0475] 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, based on execution by the at least one processor, may cause the first device to: obtain information related to a maximum count for detecting listen before talk (LBT) failures; and detect persistent LBT failures based on an LBT counter being greater than or equal to the maximum count for detecting LBT failures. For example, a first LBT counter may be incremented by 1 for a first RB (resource block) set based on obtaining information related to an LBT failure for the first RB set. For example, the second LBT counter may be incremented by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that no guard band is set between the RB sets.

[0476] 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, based on execution by the at least one processor, may cause the first device to: obtain information related to a maximum count for detecting listen before talk (LBT) failures; and detect persistent LBT failures based on an LBT counter being greater than or equal to the maximum count for detecting LBT failures. For example, a first LBT counter may be incremented by 1 for a first RB (resource block) set based on obtaining information related to an LBT failure for the first RB set. For example, the second LBT counter may be incremented by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that no guard band is set between the RB sets.

[0477] 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: obtain information related to a maximum count for detecting listen before talk (LBT) failures; and detect persistent LBT failures based on an LBT counter being greater than or equal to the maximum count for detecting LBT failures. For example, a first LBT counter may be incremented by 1 for a first RB (resource block) set based on information about an LBT failure for the first RB set being obtained. For example, a second LBT counter may be incremented by 1 for a second RB set that is different from the first RB set based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that a guard band is not set between the RB sets.

[0478] FIG. 23 illustrates a method for a second device to perform wireless communication according to an embodiment of the present disclosure. The embodiment of FIG. 23 may be combined with various embodiments of the present disclosure.

[0479] Referring to FIG. 23, in step S2310, the second device may receive control information for scheduling a physical shared channel from the first device on a physical control channel. In step S2320, the second device may receive data from the first device on the physical shared channel. For example, information related to a maximum count for listen before talk (LBT) failure detection may be acquired by the first device. For example, based on the failure of reception of the data due to an LBT failure, the first LBT counter for the first device may be increased by 1 for the first RB set on which reception was failed. For example, the second LBT counter for the first device may be increased by 1 for the second RB set, which is a different RB set from the first RB set, based on the first LBT counter being increased by 1 for the first RB set and based on the fact that a guard band is not set between RB sets.

[0480] For example, the LBT counter may be incremented per RB set. For example, persistent LBT failures may be detected per RB set.

[0481] For example, a first persistent LBT may be detected for the first RB set based on the first LBT counter being greater than or equal to a maximum count for LBT failure detection. For example, a second persistent LBT may be detected for the second RB set based on the second LBT counter being greater than or equal to a maximum count for LBT failure detection.

[0482] For example, the second RB set may be an RB set adjacent to the first RB set.

[0483] For example, resources in the first RB set in which the first persistent LBT failure is detected and the second RB set in which the second persistent LBT failure is detected may be excluded from resource reselection.

[0484] For example, resource reselection may be triggered on resources excluding resources in the first RB set in which the first persistent LBT failure is detected and the second RB set in which the second persistent LBT failure is detected.

[0485] For example, grants associated with a first set of RBs in which the first persistent LBT failure is detected and a second set of RBs in which the second persistent LBT failure is detected may be cleared.

[0486] For example, a radio link failure (RLF) can be detected based on persistent LBT failures detected for all RB sets.

[0487] For example, based on the detection of persistent LBT failures on a resource pool basis, resources in a first resource pool including a first set of RBs in which the first persistent LBT failure is detected and a second resource pool including a second set of RBs in which the second persistent LBT failure is detected may be excluded from resource reselection.

[0488] For example, based on the detection of a persistent LBT failure on a resource pool basis, grants associated with a first resource pool including a first set of RBs in which the first persistent LBT failure is detected and a second resource pool including a second set of RBs in which the second persistent LBT failure is detected may be cleared.

[0489] For example, based on the detection of persistent LBT failures in bandwidth part (BWP) units, resources in a first BWP including a first set of RBs in which the first persistent LBT failure is detected and a BWP including a second RB in which the second persistent LBT failure is detected may be excluded from resource selection or reselection.

[0490] For example, based on the detection of a persistent LBT failure on a BWP basis, a grant associated with a first BWP including a first set of RBs in which the first persistent LBT failure is detected and a BWP including a second set of RBs in which the second persistent LBT failure is detected may be cleared.

[0491] For example, a persistent LBT failure may be a sidelink persistent LBT failure.

[0492] 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 control information for scheduling a physical shared channel from the first device on a physical control channel. Then, the processor (202) of the second device (200) can control the transceiver (206) to receive data from the first device on the physical shared channel. For example, information related to a maximum count for listen before talk (LBT) failure detection can be acquired by the first device. For example, based on the failure of data reception due to an LBT failure, the first LBT counter for the first device can be increased by 1 for the first RB set for which reception failed. For example, the second LBT counter for the first device may be incremented by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that no guard band is set between the RB sets.

[0493] 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, from a first device, control information for scheduling a physical shared channel on a physical control channel; and receive, from the first device, data on the physical shared channel. For example, information related to a maximum count for listen before talk (LBT) failure detection may be acquired by the first device. For example, based on a failure in reception of the data due to an LBT failure, a first LBT counter for the first device may be incremented by 1 for a first set of RBs for which reception failed. For example, the second LBT counter for the first device may be incremented by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that no guard band is set between the RB sets.

[0494] 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, based on execution by the at least one processor, may cause the second device to: receive, from a first device, control information for scheduling a physical shared channel on a physical control channel; and receive, from the first device, data on the physical shared channel. For example, information related to a maximum count for listen before talk (LBT) failure detection may be acquired by the first device. For example, based on a failure in reception of the data due to an LBT failure, a first LBT counter for the first device may be incremented by 1 for a first set of RBs for which reception has failed. For example, the second LBT counter for the first device may be incremented by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that no guard band is set between the RB sets.

[0495] 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, from a first device, control information for scheduling a physical shared channel on a physical control channel; and receive, from the first device, data on the physical shared channel. For example, information related to a maximum count for listen before talk (LBT) failure detection may be acquired by the first device. For example, based on a failure in reception of the data due to an LBT failure, a first LBT counter for the first device may be incremented by 1 for a first set of RBs on which reception failed. For example, the second LBT counter for the first device may be incremented by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that no guard band is set between the RB sets.

[0496] The various embodiments of the present disclosure may be combined with each other.

[0497] Below, a description is given of devices to which various embodiments of the present disclosure can be applied.

[0498] 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.

[0499] 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.

[0500] Fig. 24 illustrates a communication system (1) according to one embodiment of the present disclosure. The embodiment of Fig. 24 can be combined with various embodiments of the present disclosure.

[0501] Referring to FIG. 24, 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.

[0502] 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.

[0503] 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).

[0504] 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.

[0505] FIG. 25 illustrates a wireless device according to an embodiment of the present disclosure. The embodiment of FIG. 25 may be combined with various embodiments of the present disclosure.

[0506] Referring to FIG. 25, 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. 24.

[0507] 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.

[0508] 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.

[0509] 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.

[0510] 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.

[0511] 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.

[0512] 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.

[0513] FIG. 26 illustrates a signal processing circuit for a transmission signal according to an embodiment of the present disclosure. The embodiment of FIG. 26 can be combined with various embodiments of the present disclosure.

[0514] Referring to FIG. 26, 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. 26 may be performed in the processor (102, 202) and / or the transceiver (106, 206) of FIG. 25. The hardware elements of FIG. 26 may be implemented in the processor (102, 202) and / or the transceiver (106, 206) of FIG. 25. For example, blocks 1010 to 1060 may be implemented in the processor (102, 202) of FIG. 25. Additionally, blocks 1010 to 1050 may be implemented in the processor (102, 202) of FIG. 25, and block 1060 may be implemented in the transceiver (106, 206) of FIG. 25.

[0515] The codeword can be converted into a wireless signal through the signal processing circuit (1000) of FIG. 26. Here, the codeword is an encoded bit sequence of an information block. The information block can include a transport block (e.g., an UL-SCH transport block, a DL-SCH transport block). The wireless signal can be transmitted through various physical channels (e.g., a PUSCH or a PDSCH).

[0516] 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.

[0517] 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.

[0518] 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. 26. For example, a wireless device (e.g., 100, 200 of FIG. 25) 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.

[0519] Figure 27 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 Figure 24). The embodiment of Figure 27 may be combined with various embodiments of the present disclosure.

[0520] Referring to FIG. 27, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 25 and may be composed of various elements, components, units / 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. 25. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 25. 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).

[0521] 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 unit (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. 24, 100a), a vehicle (Fig. 24, 100b-1, 100b-2), an XR device (Fig. 24, 100c), a portable device (Fig. 24, 100d), a home appliance (Fig. 24, 100e), an IoT device (Fig. 24, 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. 24, 400), a base station (Fig. 24, 200), a network node, etc. Wireless devices may be mobile or stationary depending on the use / service.

[0522] In FIG. 27, 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.

[0523] Below, the implementation example of Fig. 27 is described in more detail with reference to the drawings.

[0524] FIG. 28 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. 28 may be combined with various embodiments of the present disclosure.

[0525] Referring to FIG. 28, 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. 27, respectively.

[0526] 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.

[0527] 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).

[0528] Figure 29 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 29 may be combined with various embodiments of the present disclosure.

[0529] Referring to FIG. 29, 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. 27, respectively.

[0530] 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.

[0531] 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.

[0532] 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. A method performed by a first device in a wireless communication system, A step of obtaining information related to the maximum count for LBT (listen before talk) failure detection; and A step of detecting a persistent LBT failure based on the LBT counter being greater than or equal to the maximum count for the LBT failure detection; The first LBT counter is incremented by 1 for the first RB (resource block) set based on the acquisition of information about an LBT failure for the first RB (resource block) set, and A method wherein a second LBT counter is incremented by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that a guard band between RB sets is not set.

2. In paragraph 1, The above LBT counter is incremented by RB set units, and A method wherein the above continuous LBT failure is detected in units of the RB set.

3. In paragraph 1, A first persistent LBT is detected for the first RB set based on the first LBT counter being greater than or equal to a maximum count for LBT failure detection, and A method wherein a second persistent LBT is detected for the second RB set based on the second LBT counter being greater than or equal to a maximum count for LBT failure detection.

4. In paragraph 1, A method wherein the second RB set is an RB set adjacent to the first RB set.

5. In paragraph 3, A method in which resources in a first RB set in which the first persistent LBT failure is detected and a second RB set in which the second persistent LBT failure is detected are excluded from resource reselection.

6. In paragraph 5, A method in which resource reselection is triggered in resources excluding resources in a first RB set in which the first persistent LBT failure is detected and a second RB set in which the second persistent LBT failure is detected.

7. In paragraph 3, A method in which grants associated with a first set of RBs in which a first persistent LBT failure is detected and a second set of RBs in which a second persistent LBT failure is detected are cleared.

8. In paragraph 1, A method in which a radio link failure (RLF) is detected based on the above-mentioned persistent LBT failure being detected for all RB sets.

9. In paragraph 3, A method wherein resources in a first resource pool including a first set of RBs in which the first persistent LBT failure is detected and a second resource pool including a second set of RBs in which the second persistent LBT failure is detected are excluded from resource reselection based on the persistent LBT failure being detected on a resource pool basis.

10. In paragraph 3, A method wherein, based on the detection of the persistent LBT failure on a resource pool basis, grants associated with a first resource pool including a first set of RBs in which the first persistent LBT failure is detected and a second resource pool including a second set of RBs in which the second persistent LBT failure is detected are cleared.

11. In paragraph 3, A method wherein, based on the detection of the above persistent LBT failure in units of BWP (bandwidth part), resources in a first BWP including a first set of RBs in which the first persistent LBT failure is detected and a BWP including a second RB in which the second persistent LBT failure is detected are excluded from resource selection or reselection.

12. In paragraph 3, A method wherein a grant associated with a first BWP including a first set of RBs in which the first persistent LBT failure is detected and a BWP including a second set of RBs in which the second persistent LBT failure is detected are cleared based on the persistent LBT failure being detected in a BWP unit.

13. In paragraph 1, The above continuous LBT failure is a side link continuous LBT failure.

14. In a first device configured to perform wireless communication, At least one transmitter / receiver; at least one processor; and At least one memory connected to said at least one processor and storing instructions, said instructions being executed by said at least one processor, wherein said first device causes: Obtain information related to the maximum count for LBT (listen before talk) failure detection; and Detect persistent LBT failures based on the LBT counter being greater than or equal to the maximum count for the above LBT failure detection, The first LBT counter is incremented by 1 for the first RB (resource block) set based on the acquisition of information about an LBT failure for the first RB (resource block) set, and A first device, wherein the second LBT counter is incremented by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that a guard band between RB sets is not set.

15. In a processing device set to control the first device, at least one processor; and At least one memory connected to said at least one processor and storing instructions, said instructions being executed by said at least one processor, wherein said first device causes: Obtain information related to the maximum count for LBT (listen before talk) failure detection; and Detect persistent LBT failures based on the LBT counter being greater than or equal to the maximum count for the above LBT failure detection, The first LBT counter is incremented by 1 for the first RB (resource block) set based on the acquisition of information about an LBT failure for the first RB (resource block) set, and A processing device, wherein the second LBT counter is incremented by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that a guard band between RB sets is not set.

16. A non-transitory computer-readable storage medium that records commands, The above commands, when executed, cause the first device to: Obtain information related to the maximum count for LBT (listen before talk) failure detection; and Detect persistent LBT failures based on the LBT counter being greater than or equal to the maximum count for the above LBT failure detection, The first LBT counter is incremented by 1 for the first RB (resource block) set based on the acquisition of information about an LBT failure for the first RB (resource block) set, and A non-transitory computer-readable storage medium in which a second LBT counter is incremented by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that a guard band between RB sets is not set.

17. In a method performed by a second device in a wireless communication system, A step of receiving control information for scheduling a physical shared channel on a physical control channel from a first device; and A step of receiving data from the first device on the physical shared channel; Information related to the maximum count for LBT (listen before talk) failure detection is acquired by the first device, Based on the failure of reception of the data due to LBT failure, the first LBT counter for the first device is increased by 1 for the first RB (resource block) set for which reception was failed, and A method wherein a second LBT counter for the first device is incremented by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being incremented by 1 for the first RB set and based on the fact that a guard band between RB sets is not set.

18. In a second device configured to perform wireless communication, At least one transmitter / receiver; at least one processor; and At least one memory connected to said at least one processor and storing instructions, said instructions being executed by said at least one processor, wherein said second device causes: From the first device, control information for scheduling a physical shared channel is received on a physical control channel; and From the first device, data is received on the physical shared channel, Information related to the maximum count for LBT (listen before talk) failure detection is acquired by the first device, Based on the failure of reception of the data due to LBT failure, the first LBT counter for the first device is increased by 1 for the first RB (resource block) set for which reception was failed, and A second device, wherein the second LBT counter for the first device is increased by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being increased by 1 for the first RB set and based on the fact that a guard band between RB sets is not set.

19. In a processing device set to control a second device, at least one processor; and At least one memory connected to said at least one processor and storing instructions, said instructions being executed by said at least one processor, wherein said second device causes: From the first device, control information for scheduling a physical shared channel is received on a physical control channel; and From the first device, data is received on the physical shared channel, Information related to the maximum count for LBT (listen before talk) failure detection is acquired by the first device, Based on the failure of reception of the data due to LBT failure, the first LBT counter for the first device is increased by 1 for the first RB (resource block) set for which reception was failed, and A processing device, wherein the second LBT counter for the first device is increased by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being increased by 1 for the first RB set and based on the fact that a guard band between RB sets is not set.

20. A non-transitory computer-readable storage medium that records commands, The above commands, when executed, cause the second device to: From the first device, control information for scheduling a physical shared channel is received on a physical control channel; and From the first device, data is received on the physical shared channel, Information related to the maximum count for LBT (listen before talk) failure detection is acquired by the first device, Based on the failure of reception of the data due to LBT failure, the first LBT counter for the first device is increased by 1 for the first RB (resource block) set for which reception was failed, and A non-transitory computer-readable storage medium, wherein the second LBT counter for the first device is increased by 1 for a second RB set that is a different RB set from the first RB set, based on the first LBT counter being increased by 1 for the first RB set and based on the fact that a guard band between RB sets is not set.

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