Method and apparatus for performing communication on basis of carrier aggregation

Abstract

Provided are a method by which a first device performs wireless communication and an apparatus supporting same. The first device may: establish a PC5 radio resource control (RRC) connection with a second device; select a plurality of carriers; on the basis of the number of continuous discontinuous transmissions (DTXs) for a carrier from among the plurality of carriers reaching a threshold, release the carrier; and detect a sidelink radio link failure on the basis of release of all of the plurality of carriers.

Description

Method and device for performing communication based on carrier aggregation

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

[0002] Sidelink (SL) refers to a communication method that establishes a direct link between user equipment (UE) and directly exchanges voice or data between terminals without going through a base station (BS). SL is being considered as a solution to solve the burden on base stations due to rapidly increasing data traffic. V2X (vehicle-to-everything) refers to a communication technology that exchanges information with other vehicles, pedestrians, and objects with built-in infrastructure through wired / wireless communication. V2X can be divided into four types: V2V (vehicle-to-vehicle), V2I (vehicle-to-infrastructure), V2N (vehicle-to-network), and V2P (vehicle-to-pedestrian). V2X communication can be provided through the PC5 interface and / or the Uu interface.

[0003] Meanwhile, as more and more communication devices demand greater communication capacity, the need for improved mobile broadband communication compared to existing Radio Access Technology (RAT) is emerging. Accordingly, communication systems that consider reliability and latency-sensitive services or terminals are being discussed. Next-generation wireless access technologies that take into account improved mobile broadband communication, massive Machine Type Communication (MTC), and Ultra-Reliable and Low Latency Communication (URLLC) can be referred to as new RAT (new radio access technology) or NR (new radio).

[0004] In one embodiment, a method for a first device to perform wireless communication is provided. The method may include: establishing a PC5 RRC (radio resource control) connection with a second device; selecting a plurality of carriers; releasing a carrier based on a number of continuous discontinuous transmissions (DTXs) ​​for a carrier among the plurality of carriers reaching a threshold; and detecting a sidelink radio link failure based on all of the plurality of carriers being released.

[0005] In one embodiment, a first device configured to perform wireless communication is provided. The first device includes 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: establish a PC5 RRC (radio resource control) connection with a second device; select a plurality of carriers; release a carrier based on a number of continuous discontinuous transmissions (DTXs) ​​for a carrier among the plurality of carriers reaching a threshold; and detect a sidelink radio link failure based on all of the plurality of carriers being released.

[0006] In one embodiment, a processing device configured to control a first device is provided. The processing device includes 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: establish a PC5 RRC (radio resource control) connection with a second device; select a plurality of carriers; release a carrier based on a number of continuous discontinuous transmissions (DTXs) ​​for a carrier among the plurality of carriers reaching a threshold; and detect a sidelink radio link failure based on all of the plurality of carriers being released.

[0007] In one embodiment, a non-transitory computer-readable storage medium having instructions recorded thereon is provided. The instructions, when executed, cause a first device to: establish a PC5 RRC (radio resource control) connection with a second device; select a plurality of carriers; release a carrier based on a number of continuous discontinuous transmissions (DTXs) ​​for a carrier among the plurality of carriers reaching a threshold; and detect a sidelink radio link failure based on all of the plurality of carriers being released.

[0008] FIG. 1 illustrates a communication structure that can be provided in a 6G system according to one embodiment of the present disclosure.

[0009] FIG. 2 illustrates an electromagnetic spectrum according to one embodiment of the present disclosure.

[0010] FIG. 3 illustrates the structure of an NR system according to one embodiment of the present disclosure.

[0011] FIG. 4 illustrates a radio protocol architecture according to an embodiment of the present disclosure.

[0012] FIG. 5 illustrates the structure of a radio frame of NR according to one embodiment of the present disclosure.

[0013] FIG. 6 illustrates a slot structure of an NR frame according to one embodiment of the present disclosure.

[0014] FIG. 7 illustrates an example of a BWP according to one embodiment of the present disclosure.

[0015] FIG. 8 illustrates a procedure for a terminal to perform V2X or SL communication according to a transmission mode, according to one embodiment of the present disclosure.

[0016] FIG. 9 illustrates three cast types according to one embodiment of the present disclosure.

[0017] FIG. 10 illustrates a resource unit for measuring channel busy ratio (CBR) according to one embodiment of the present disclosure.

[0018] FIG. 11 illustrates an example of overlapping PSFCH time resources between multiple carriers, according to one embodiment of the present disclosure.

[0019] FIG. 12 illustrates a method for a first device to perform wireless communication according to one embodiment of the present disclosure.

[0020] FIG. 13 illustrates a method for a second device to perform wireless communication according to one embodiment of the present disclosure.

[0021] Fig. 14 illustrates a communication system (1) according to one embodiment of the present disclosure.

[0022] FIG. 15 illustrates a wireless device according to an embodiment of the present disclosure.

[0023] FIG. 16 illustrates a signal processing circuit for a transmission signal according to one embodiment of the present disclosure.

[0024] FIG. 17 illustrates a wireless device according to one embodiment of the present disclosure.

[0025] FIG. 18 illustrates a mobile device according to one embodiment of the present disclosure.

[0026] FIG. 19 illustrates a vehicle or autonomous vehicle according to one embodiment of the present disclosure.

[0027] 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."

[0028] 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."

[0029] 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".

[0030] 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.”

[0031] 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."

[0032] In the following explanation, ‘when, if, in case of’ can be replaced with ‘based on’.

[0033] Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously.

[0034] 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.

[0035] The following technologies 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, and E-UTRA (evolved UTRA). IEEE 802.16m is an evolution of IEEE 802.16e, providing backward compatibility with systems based on IEEE 802.16e. UTRA is part of UMTS (universal mobile telecommunications system). 3GPP (3rd generation partnership project) LTE (long term evolution) is a part of E-UMTS (evolved UMTS) that uses E-UTRA (evolved-UMTS terrestrial radio access), employing OFDMA in the downlink and SC-FDMA in the uplink.LTE-A (advanced) is an evolution of 3GPP LTE.

[0036] 5G NR, the successor to LTE-A, is a new clean-slate mobile communications system featuring 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.

[0037] 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 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. In other words, Table 1 is an example of the requirements of a 6G system.

[0038] Per device peak data rate1 TbpsE2E latency1 msMaximum spectral efficiency100bps / HzMobility supportUp to 1000km / hrSatellite integrationFullyAIFullyAutonomous vehicleFullyXRFullyHaptic CommunicationFully

[0039] 6G systems can have key factors such as enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), massive machine-type communication (mMTC), AI integrated communication, tactile internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion, and enhanced data security.

[0040] 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.

[0041] 6G systems are expected to have 50 times the simultaneous wireless connectivity of 5G systems. URLLC, a key feature of 5G, will become even more crucial in 6G communications by providing end-to-end latency of less than 1 ms. 6G systems will have significantly higher volumetric spectral efficiency, compared to the commonly used area spectral efficiency. 6G systems can offer extremely long battery life and advanced battery technologies for energy harvesting, eliminating the need for separate charging for mobile devices in 6G systems. New network characteristics in 6G may include:

[0042] - Satellite integrated network: 6G is expected to integrate with satellites to provide a global mobile network. The integration of terrestrial, satellite, and airborne networks into a single wireless communications system is crucial for 6G.

[0043] 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).

[0044] - Seamless integration of wireless information and energy transfer: 6G wireless networks will transfer power to charge the batteries of devices such as smartphones and sensors. Therefore, wireless information and energy transfer (WIET) will be integrated.

[0045] - 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.

[0046] Some general requirements for the new network characteristics of 6G, such as the above, may be as follows:

[0047] - Small cell networks: The concept of small cell networks was introduced to improve received signal quality in cellular systems by increasing throughput, energy efficiency, and spectral efficiency. Consequently, small cell networks are essential for 5G and beyond-5G (5GB) communication systems. Accordingly, 6G communication systems also adopt the characteristics of small cell networks.

[0048] Ultra-dense heterogeneous networks: Ultra-dense heterogeneous networks will be another key feature of 6G communication systems. Multi-tier networks comprised of heterogeneous networks improve overall QoS and reduce costs.

[0049] High-capacity backhaul: Backhaul connections are characterized by high-capacity backhaul networks to support high-volume traffic. High-speed fiber optics and free-space optics (FSO) systems may be potential solutions to this problem.

[0050] - 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.

[0051] - Softwarization and virtualization: Softwarization and virtualization are two critical features that form the foundation of the design process for 5GB networks to ensure flexibility, reconfigurability, and programmability. Furthermore, billions of devices can be shared on a shared physical infrastructure.

[0052] Below, the core implementation technologies of the 6G system are described.

[0053] - Artificial Intelligence (AI): The most important and newly introduced technology for 6G systems is AI. 4G systems did not involve AI. 5G systems will support partial or very limited AI. However, 6G systems will be fully AI-enabled for automation. Advances in machine learning will create more intelligent networks for real-time communications in 6G. Incorporating AI into communications can streamline and improve real-time data transmission. AI can use numerous analyses 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. AI can also enable 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.

[0054] - Terahertz Communication: Data rates can be increased by increasing the bandwidth. This can be achieved by utilizing sub-THz communications with wide bandwidths 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.

[0055] - Large-scale MIMO technology

[0056] - Holographic Beam Forming (HBF)

[0057] - Optical wireless technology

[0058] - Free-Space Optical Transmission Backhaul Network (FSO Backhaul Network)

[0059] - Non-Terrestrial Networks (NTN)

[0060] - Quantum Communication

[0061] - Cell-free Communication

[0062] - Integration of Wireless Information and Power Transmission

[0063] Integration of Wireless Communication and Sensing

[0064] - Integrated Access and Backhaul Network

[0065] - Big data analysis

[0066] - Reconfigurable Intelligent Surface

[0067] - Metaverse

[0068] - Blockchain

[0069] Unmanned Aerial Vehicles (UAVs): Unmanned Aerial Vehicles (UAVs), or drones, will be a key element in 6G wireless communications. In most cases, high-speed data wireless connections will be provided using UAV technology. BS entities are installed on UAVs to provide cellular connectivity. UAVs 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 communication 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.

[0070] - Autonomous Driving (Self-driving): For fully autonomous driving, vehicles must communicate with each other to notify each other of dangerous situations, and vehicles must communicate with infrastructure such as parking lots and traffic lights to confirm parking location information, signal change times, and other information. V2X (Vehicle to Everything), a key element of autonomous driving infrastructure construction, is a technology that enables 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. The amount of information that must be transmitted and received will increase dramatically to actively intervene in driving and directly control the vehicle in dangerous situations. Therefore, 6G is expected to maximize autonomous driving with faster transmission speeds and lower latency than 5G.

[0071] For clarity, the description focuses on 5G NR, but the technical concepts of one embodiment of the present disclosure are not limited thereto. Various embodiments of the present disclosure can also be applied to 6G communication systems.

[0072] FIG. 3 illustrates the structure of an NR system according to an embodiment of the present disclosure. The embodiment of FIG. 3 can be combined with various embodiments of the present disclosure.

[0073] Referring to FIG. 3, the NG-RAN (Next Generation - Radio Access Network) may include a base station (20) that provides user plane and control plane protocol termination to a terminal (10). For example, the base station (20) may include a next generation Node B (gNB) and / or an evolved Node B (eNB). For example, the terminal (10) may be fixed or mobile, and may be referred to by other terms such as a Mobile Station (MS), a User Terminal (UT), a Subscriber Station (SS), a Mobile Terminal (MT), or a Wireless Device. For example, the base station may be a fixed station that communicates with the terminal (10), and may be referred to by other terms such as a Base Transceiver System (BTS), or an Access Point.

[0074] The embodiment of Fig. 3 exemplifies a case including only gNB. Base stations (20) can be connected to each other via Xn interfaces. Base stations (20) can be connected to a 5th generation core network (5G Core Network: 5GC) via an NG interface. More specifically, base stations (20) can be connected to an access and mobility management function (AMF) (30) via an NG-C interface, and can be connected to a user plane function (UPF) (30) via an NG-U interface.

[0075] 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.

[0076] FIG. 4 illustrates a radio protocol architecture according to an embodiment of the present disclosure. The embodiment of FIG. 4 can be combined with various embodiments of the present disclosure. Specifically, (a) of FIG. 4 illustrates a radio protocol stack of a user plane for Uu communication, and (b) of FIG. 4 illustrates a radio protocol stack of a control plane for Uu communication. (c) of FIG. 4 illustrates a radio protocol stack of a user plane for SL communication, and (d) of FIG. 4 illustrates a radio protocol stack of a control plane for SL communication.

[0077] Referring to Figure 4, 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 via the transport channel. Transport channels are classified based on how and with what characteristics data is transmitted over the wireless interface.

[0078] 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.

[0079] 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.

[0080] 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).

[0081] 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 the 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.

[0082] 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.

[0083] 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.

[0084] Establishing a Radio Bearer (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.

[0085] 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.

[0086] 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.

[0087] 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).

[0088] FIG. 5 illustrates the structure of a radio frame of NR according to an embodiment of the present disclosure. The embodiment of FIG. 5 can be combined with various embodiments of the present disclosure.

[0089] Referring to FIG. 5, radio frames can be used for uplink and downlink transmission in NR. A radio frame has a length of 10 ms and can be defined as two 5 ms half-frames (Half-Frames, HF). A half-frame can include five 1 ms sub-frames (Subframes, SF). A sub-frame can be divided into one or more slots, and the number of slots within a sub-frame can be determined by the Subcarrier Spacing (SCS). Each slot can include 12 or 14 OFDM (A) symbols depending on the cyclic prefix (CP).

[0090] 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).

[0091] Table 2 below shows the number of symbols per slot (N) depending on the SCS setting (u) when normal CP or extended CP is used. slot symb ), number of slots per frame (N frame,u slot ) and the number of slots per subframe (N subframe,u slot ) is an example.

[0092] CP type SCS (15*2 u )N slot symb N frame,u slot N subframe,u slotNormal CP15kHz (u=0)1410130kHz (u=1)1420260kHz (u=2)14404120kHz (u=3)14808240kHz (u=4)1416016Extended CP60kHz (u=2)12404

[0093] In an NR system, OFDM(A) numerology (e.g., SCS, CP length, etc.) may be set differently between multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., subframe, slot, or TTI) (conveniently referred to as TU (Time Unit)) consisting of the same number of symbols may be set differently between the merged cells.

[0094] In NR, multiple numerologies, or SCSs, can be supported to support various 5G services. For example, a 15 kHz SCS can support wide areas in traditional cellular bands, while a 30 kHz / 60 kHz SCS can support dense urban areas, lower latency, and wider carrier bandwidth. A 60 kHz or higher SCS can support bandwidths greater than 24.25 GHz to overcome phase noise.

[0095] The NR frequency band can be defined by two types of frequency ranges. The two types of frequency ranges can be FR1 and FR2. The numerical values ​​of the frequency ranges can be changed, and for example, the two types of frequency ranges can be as shown in Table 3 below. Among the frequency ranges used in the NR system, FR1 can mean the "sub 6 GHz range", and FR2 can mean the "above 6 GHz range" and can be called millimeter wave (mmW).

[0096] Frequency Range designationCorresponding frequency rangeSubcarrier Spacing (SCS)FR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0097] As described above, the numerical value of the frequency range of the NR system can be changed. For example, FR1 may include a band from 410 MHz to 7125 MHz, as shown in Table 4 below. That is, FR1 may include a frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.). For example, the frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.) included within FR1 may include an unlicensed band. The unlicensed band may be used for various purposes, such as for vehicular communications (e.g., autonomous driving).

[0098] Frequency Range designationCorresponding frequency rangeSubcarrier Spacing (SCS)FR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0099] FIG. 6 illustrates a slot structure of an NR frame according to an embodiment of the present disclosure. The embodiment of FIG. 6 can be combined with various embodiments of the present disclosure.

[0100] Referring to Figure 6, a slot includes multiple symbols in the time domain. For example, in the case of a normal CP, one slot may include 14 symbols, but in the case of an extended CP, one slot may include 12 symbols. Alternatively, in the case of a normal CP, one slot may include 7 symbols, but in the case of an extended CP, one slot may include 6 symbols.

[0101] A carrier includes multiple subcarriers in the frequency domain. An RB (Resource Block) can be defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A BWP (Bandwidth Part) can be defined as multiple consecutive (P)RBs ((Physical) Resource Blocks) in the frequency domain, and can correspond to one numerology (e.g., SCS, CP length, etc.). A carrier can include up to N (e.g., 5) BWPs. Data communication can be performed through activated BWPs. Each element can be referred to as a Resource Element (RE) in the resource grid, and one complex symbol can be mapped to it.

[0102] Below, BWP (Bandwidth Part) and carrier are explained.

[0103] 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.

[0104] For example, the BWP may be at least one of an active BWP, an initial BWP, and / or a default BWP. For example, the UE may not monitor the downlink radio link quality in a DL BWP other than the active DL BWP on the PCell (primary cell). For example, the UE may not receive a PDCCH, a physical downlink shared channel (PDSCH), or a CSI-RS (reference signal) (except for RRM) outside the active DL BWP. For example, the UE may not trigger a CSI (Channel State Information) report for an inactive DL BWP. For example, the UE may not transmit a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH) outside the active UL BWP. For example, for downlink, the initial BWP can be given as a contiguous set of RBs for the remaining minimum system information (RMSI) CORESET (control resource set) (set by the physical broadcast channel (PBCH)). For example, for uplink, the initial BWP can be given by the system information block (SIB) for the random access procedure. For example, the default BWP can be set by a higher layer. For example, the initial value of the default BWP can be the initial DL BWP. For energy saving, if the UE does not detect downlink control information (DCI) for a certain period of time, the UE can switch its active BWP to the default BWP.

[0105] Meanwhile, a BWP can be defined for an SL. The same SL BWP can be used for transmission and reception. For example, a transmitting terminal can transmit an SL channel or an SL signal on a specific BWP, and a receiving terminal can receive an SL channel or an SL signal on the specific BWP. In a licensed carrier, an SL BWP can be defined separately from an Uu BWP, and an SL BWP can have separate configuration signaling from an Uu BWP. For example, a terminal can receive a configuration for an SL BWP from a base station / network. For example, a terminal can receive a configuration for an Uu BWP from a base station / network. An SL BWP can be (pre-)configured for out-of-coverage NR V2X terminals and RRC_IDLE terminals within a carrier. For terminals in RRC_CONNECTED mode, at least one SL BWP can be activated within a carrier.

[0106] 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.

[0107] 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.

[0108] BWP is point A, offset from point A (N start BWP ) and bandwidth (N sizeBWP ) can be set by. For example, point A can be an outer reference point of the PRB of a carrier where subcarrier 0 of all numerologies (e.g., all numerologies supported by the network on that carrier) aligns. For example, the offset can be the PRB spacing between the lowest subcarrier in a given numerology and point A. For example, the bandwidth can be the number of PRBs in a given numerology.

[0109] Below, V2X or SL communication is explained.

[0110] SLSS (Sidelink Synchronization Signal) is an SL-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 and obtain synchronization using S-PSS. For example, a terminal may obtain detailed synchronization and detect a synchronization signal ID using S-PSS and S-SSS.

[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] For example, a terminal can generate an S-SS / PSBCH block (i.e., S-SSB), and the terminal can map the S-SS / PSBCH block (i.e., S-SSB) onto a physical resource and transmit it. For example, the time-frequency structure of the S-SS / PSBCH block can be as follows.

[0114] In the time domain, the S-SS / PSBCH block is N S-SSB symb It can be composed of OFDM symbols, and is numbered from 0 to N within an S-SS / PSBCH block. S-SSB symb -1 can be numbered in ascending order, where the PSBCH with S-PSS, S-SSS and associated DM-RS can be mapped to the symbols given in Table 5. The number of OFDM symbols in an S-SS / PSBCH block is N for the normal cyclic prefix. S-SSB symb =13 and N for extended cyclic prefix S-SSB symb =11. The first OFDM symbol in an S-SS / PSBCH block may be the first OFDM symbol of a slot.

[0115] In the frequency domain, an S-SS / PSBCH block may be composed of 132 consecutive subcarriers, with subcarrier numbers assigned in ascending order from 0 to 131 within the sidelink S-SS / PSBCH block. The quantities k and l may represent frequency and time indices, respectively, within one sidelink S-SS / PSBCH block.

[0116] Channel or signalOFDM symbol number lrelative to the start of an S-SS / PSBCH blockSubcarrier number krelative to the start of an S-SS / PSBCH blockS-PSS1, 22, 3, ..., 127, 128S-SSS3, 42, 3, ..., 127, 128Set to zero1, 2, 3, 40, 1, 129, 130, 131PSBCH0, 5, 6, ..., N S-SSB symb -10, 1, ..., 131DM-RS for PSBCH0, 5, 6, ..., N S-SSB symb -10, 4, 8, ..., 128

[0117] FIG. 8 illustrates a procedure for a terminal to perform V2X or SL communication according to a transmission mode, according to an embodiment of the present disclosure. The embodiment of FIG. 8 may be combined with various embodiments of the present disclosure. In various embodiments of the present disclosure, the transmission mode may be referred to as a mode or a resource allocation mode. Hereinafter, for convenience of explanation, the transmission mode in LTE may be referred to as an LTE transmission mode, and the transmission mode in NR may be referred to as an NR resource allocation mode.

[0118] For example, (a) of Fig. 8 represents terminal operation related to LTE transmission mode 1 or LTE transmission mode 3. Or, for example, (a) of Fig. 8 represents terminal operation related to NR resource allocation mode 1. For example, LTE transmission mode 1 can be applied to general SL communication, and LTE transmission mode 3 can be applied to V2X communication.

[0119] For example, (b) of FIG. 8 represents terminal operation related to LTE transmission mode 2 or LTE transmission mode 4. Or, for example, (b) of FIG. 8 represents terminal operation related to NR resource allocation mode 2.

[0120] Referring to (a) of FIG. 8, in LTE transmission mode 1, LTE transmission mode 3, or NR 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.

[0121] 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.

[0122] 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 of SL. For example, the format of the DCI may be DCI format 3_0 or DCI format 3_1.

[0123] Below, an example of DCI format 3_0 is described.

[0124] DCI format 3_0 is used for scheduling NR PSCCH and NR PSSCH in one cell.

[0125] The following information is transmitted via DCI format 3_0 with CRC scrambled by SL-RNTI or SL-CS-RNTI.

[0126] - Resource Pool Index - ceiling (log2I) bits, where I is the number of resource pools for transmission, set by the upper layer parameter sl-TxPoolScheduling.

[0127] - Time gap - 3 bits determined by the upper layer parameter sl-DCI-ToSL-Trans

[0128] - HARQ process number - 4 bits

[0129] - New data indicator - 1 bit

[0130] - Lowest index of subchannel allocation for initial transmission - ceiling (log2(N SL subChannel)) bit

[0131] - SCI Format 1-A Field: Frequency Resource Allocation, Time Resource Allocation

[0132] - PSFCH-to-HARQ feedback timing indicator - ceiling (log2N fb_timing ) bits, where N fb_timing is the number of entries of the upper layer parameter sl-PSFCH-ToPUCCH.

[0133] - PUCCH resource indicator - 3 bits

[0134] - Configuration Index - 0 bit if the UE is not configured to monitor DCI format 3_0 with CRC scrambled by SL-CS-RNTI; otherwise, 3 bits. If the UE is configured to monitor DCI format 3_0 with CRC scrambled by SL-CS-RNTI, this field is reserved for DCI format 3_0 with CRC scrambled by SL-RNTI.

[0135] - Counter sidelink allocation index - 2 bits, 2 bits if the UE is set to pdsch-HARQ-ACK-Codebook = dynamic, 2 bits if the UE is set to pdsch-HARQ-ACK-Codebook = semi-static

[0136] - Padding bits if needed

[0137] Referring to (b) of FIG. 8, in LTE transmission mode 2, LTE transmission mode 4, or NR resource allocation mode 2, the terminal can determine SL transmission resources within SL resources set by the base station / network or preset SL resources. For example, the set SL resources or preset SL resources may be a resource pool. For example, the terminal can autonomously select or schedule resources for SL transmission. For example, the terminal can perform SL communication by selecting resources by itself within the set resource pool. For example, the terminal can select resources by itself within a selection window by performing sensing and resource (re)selection procedures. For example, the sensing can be performed on a subchannel basis. For example, in step S810, the first terminal that has selected resources by itself within the resource pool transmits PSCCH (e.g., SCI (Sidelink Control Information) or 1 st -stage SCI) can be transmitted to the second terminal. In step S820, the first terminal transmits the PSSCH (e.g., 2) related to the PSCCH. nd -stage SCI, MAC PDU, data, etc.) can be transmitted to the second terminal. In step S830, the first terminal can receive a PSFCH related to the PSCCH / PSSCH from the second terminal.

[0138] Referring to (a) or (b) of FIG. 8, for example, a first terminal may transmit an SCI to a second terminal on a PSCCH. Or, for example, the first terminal may transmit two consecutive SCIs (e.g., 2-stage SCIs) to the second terminal on the PSCCH and / or the PSSCH. In this case, the second terminal may decode the two consecutive SCIs (e.g., 2-stage SCIs) to receive the PSSCH from the first terminal. In the present specification, an SCI transmitted on a PSCCH is 1 st SCI, 1st SCI, 1 st -stage SCI or 1 st -stage SCI format, and the SCI transmitted on the PSSCH is 2 nd SCI, 2nd SCI, 2 nd -stage SCI or 2 nd -stage SCI format can be called. For example, 1 st -stage SCI format can include SCI format 1-A, 2 nd -stage SCI format may include SCI Format 2-A and / or SCI Format 2-B.

[0139] Below, an example of SCI format 1-A is described.

[0140] SCI Format 1-A is a 2-bit format on the PSSCH and PSSCH nd -stage is used for scheduling SCI.

[0141] The following information is transmitted using SCI Format 1-A.

[0142] - Priority - 3 bits

[0143] - Frequency resource allocation - If the value of the upper layer parameter sl-MaxNumPerReserve is set to 2, then ceiling (log2(N SL subChannel(N SLsubChannel+1) / 2)) bits; otherwise, if the value of the upper layer parameter sl-MaxNumPerReserve is set to 3, ceiling log2(N SL subChannel(N SL subChannel+1)(2N SL subChannel+1) / 6) bits

[0144] - Time resource allocation - 5 bits if the value of the upper layer parameter sl-MaxNumPerReserve is set to 2; otherwise, 9 bits if the value of the upper layer parameter sl-MaxNumPerReserve is set to 3.

[0145] - Resource reservation cycle - ceiling (log2N) rsv_period ) bits, where N rsv_period The number of entries in the upper layer parameter sl-ResourceReservePeriodList if the upper layer parameter sl-MultiReserveResource is set; otherwise, 0 bits.

[0146] - DMRS pattern - ceiling (log2N pattern ) bits, where N pattern is the number of DMRS patterns set by the upper layer parameter sl-PSSCH-DMRS-TimePatternList.

[0147] - 2 nd -stage SCI format - 2 bits as defined in Table 6

[0148] - Beta_Offsets indicator - 2 bits as provided by the upper layer parameter sl-BetaOffsets2ndSCI

[0149] - Number of DMRS ports

[0150] - Modulation and coding method - 5 bits

[0151] - Additional MCS table indicator - 1 bit if one MCS table is set by the upper layer parameter sl-Additional-MCS-Table; 2 bits if two MCS tables are set by the upper layer parameter sl-Additional-MCS-Table; otherwise 0 bits

[0152] - PSFCH Overhead Indicator - 1 bit if the upper layer parameter sl-PSFCH-Period = 2 or 4; otherwise 0 bit

[0153] - Reserved bits - The number of bits determined by the upper layer parameter sl-NumReservedBits, whose value is set to 0.

[0154] Value of 2nd-stage SCI format field2nd-stage SCI format00SCI format 2-A01SCI format 2-B10Reserved11Reserved

[0155] Below, an example of SCI format 2-A is described.

[0156] In HARQ operation, when HARQ-ACK information contains ACK or NACK, or when HARQ-ACK information contains only NACK, or when there is no feedback of HARQ-ACK information, SCI format 2-A is used for decoding PSSCH.

[0157] The following information is transmitted via SCI Format 2-A.

[0158] - HARQ process number - 4 bits

[0159] - New data indicator - 1 bit

[0160] - Redundancy version - 2 bits

[0161] - Source ID - 8 bits

[0162] - Destination ID - 16 bits

[0163] - HARQ feedback enable / disable indicator - 1 bit

[0164] - Cast type indicator - 2 bits as defined in Table 7

[0165] - CSI request - 1 bit

[0166] Value of Cast type indicatorCast type00Broadcast01Groupcast when HARQ-ACK information includes ACK or NACK10Unicast11Groupcast when HARQ-ACK information includes only NACK

[0167] Below, an example of SCI format 2-B is described.

[0168] In HARQ operation, when HARQ-ACK information contains only NACK or there is no feedback of HARQ-ACK information, SCI format 2-B is used for decoding PSSCH.

[0169] The following information is transmitted via SCI Format 2-B.

[0170] - HARQ process number - 4 bits

[0171] - New data indicator - 1 bit

[0172] - Redundancy version - 2 bits

[0173] - Source ID - 8 bits

[0174] - Destination ID - 16 bits

[0175] - HARQ feedback enable / disable indicator - 1 bit

[0176] - Zone ID - 12 bits

[0177] - Communication range requirement - 4 bits determined by the upper layer parameter sl-ZoneConfigMCR-Index

[0178] 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.

[0179] 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.

[0180] FIG. 9 illustrates three cast types according to an embodiment of the present disclosure. The embodiment of FIG. 9 can be combined with various embodiments of the present disclosure. Specifically, FIG. 9 (a) illustrates broadcast-type SL communication, FIG. 9 (b) illustrates unicast-type SL communication, and FIG. 9 (c) illustrates groupcast-type SL communication. In the case of unicast-type SL communication, a terminal can perform one-to-one communication with another terminal. In the case of groupcast-type SL communication, a terminal can perform SL communication with one or more terminals within the group to which it belongs. In various embodiments of the present disclosure, SL groupcast communication can be replaced with SL multicast communication, SL one-to-many communication, etc.

[0181] Below, the HARQ (Hybrid Automatic Repeat Request) procedure is described.

[0182] For example, SL HARQ feedback can be enabled for unicast. For example, SL HARQ feedback can be enabled for groupcast. For example, two HARQ feedback options can be supported for groupcast.

[0183] (1) Groupcast Option 1: If a receiving terminal fails to decode a transport block associated with the PSCCH after decoding a PSCCH targeting the receiving terminal, the receiving terminal may transmit a negative acknowledgment (NACK) to the transmitting terminal via a PSFCH. On the other hand, if the receiving terminal decodes a PSCCH targeting the receiving terminal and successfully decodes a transport block associated with the PSCCH, the receiving terminal may not transmit a positive acknowledgment (ACK) to the transmitting terminal.

[0184] (2) Groupcast Option 2: If the receiving terminal fails to decode a transport block associated with the PSCCH after decoding the PSCCH targeting the receiving terminal, the receiving terminal can transmit a NACK to the transmitting terminal via the PSFCH. In addition, if the receiving terminal decodes the PSCCH targeting the receiving terminal and successfully decodes the transport block associated with the PSCCH, the receiving terminal can transmit an ACK to the transmitting terminal via the PSFCH.

[0185] Below, the UE procedure for reporting HARQ-ACK on the sidelink is described.

[0186] In response to receiving the PSSCH, the UE transmits a PSFCH containing HARQ-ACK information, N PSSCH subchThe SCI format may be indicated by scheduling PSSCH reception on one or more subchannels from the subchannel number. The UE provides HARQ-ACK information including ACK, NACK, or NACK only.

[0187] The UE may be provided with the number of slots in the resource pool for PSFCH transmission occasion resources by sl-PSFCH-Period-r16. If the number is 0, PSFCH transmission from the UE in the resource pool is disabled. The UE may be provided with k mod N PSFCH PSSCH = 0 if slot t' k SL (0 ≤ k < T' max ) is expected to have PSFCH transmission opportunity resources, where t' k SL is a slot belonging to the resource pool, and T' max is the number of slots belonging to the resource pool within 10240 msec, and N PSFCH PSSCH is provided in sl-PSFCH-Period-r16. The UE may be instructed by upper layers not to transmit a PSFCH in response to a PSSCH reception. When the UE receives a PSSCH from a resource pool and the HARQ Feedback Enable / Disable indicator field included in the associated SCI Format 2-A or SCI Format 2-B has a value of 1, the UE provides HARQ-ACK information via a PSFCH transmission from the resource pool. The UE transmits the PSFCH in a first slot, wherein the first slot includes a PSFCH resource and is a slot after the minimum number of slots provided by sl-MinTimeGapPSFCH-r16 of the resource pool after the last slot of the PSSCH reception.

[0188] The UE selects a set M of PRBs within the resource pool for PSFCH transmission in the PRBs of the resource pool. PSFCHPRB,set is provided by sl-PSFCH-RB-Set-r16. The number of subchannels N for the resource pool provided by sl-NumSubchannel subch and N PSFCH PSSCH For the number of PSSCH slots associated with PSFCH slots less than or equal to M, the UE PRB,set PSFCH Among PRBs, [(i+j·N PSFCH PSSCH )·M PSFCH subch,slot, (i+1+j·N PSFCH PSSCH )·M PSFCH [subch,slot-1] PRB is allocated to slot i and subchannel j among the PSSCH slots linked to the PSFCH slot. Here, M PSFCH subch,slot= M PSFCH PRB,set / (N subch ·N PSFCH PSSCH ), 0 ≤ i < N PSFCH PSSCH , 0 ≤ j < N subch , and the assignment starts in ascending order of i and continues in ascending order of j. UE is M PSFCH PRB,set Go N subch ·N PSFCH PSSCH It is expected to be a multiple of .

[0189] The UE determines the number of available PSFCH resources for multiplexing HARQ-ACK information included in the PSFCH transmission. PSFCH PRB,CS = N PSFCH type ·M PSFCH subch,slot·N PSFCH CS is determined by . Here, N PSFCH CS is the number of cyclic shift pairs for the resource pool, and based on instructions from the upper layer,

[0190] - N PSFCH type = 1 and M PSFCH subch,slotPRB is associated with the starting subchannel of the corresponding PSSCH,

[0191] - N PSFCH type = N PSSCH subch Ego and N PSSCH subch ·M PSFCH subch,slotPRB is the N of the corresponding PSSCH PSSCH subch Associated with one or more subchannels among the subchannels.

[0192] PSFCH resources are first N PSFCH type ·M PSFCH subch, slotPRB are indexed in ascending order of PRB index, then N PSFCH CS Among the cyclic shift pairs, they are indexed in ascending order of the cyclic shift pair index.

[0193] The UE, in response to receiving the PSSCH, sends an index of the PSFCH resource for PSFCH transmission (P ID + M ID ) mod R PSFCH PRB,CS is determined by . Here, P ID is the physical layer source ID provided by SCI format 2-A or 2-B for scheduling PSSCH reception, and M ID is the ID of the UE receiving the PSSCH indicated by the upper layer if the UE detects SCI format 2-A with the Cast Type Indicator field value of "01", otherwise M ID is 0.

[0194] UE uses Table 8 to determine N PSFCH CSDetermine the m0 value for calculating the cyclic shift α value from the cyclic shift pair index corresponding to the PSFCH resource index.

[0195] N PSFCH CS m0 cyclic shift pair index 0 cyclic shift pair index 1 cyclic shift pair index 2 cyclic shift pair index 3 cyclic shift pair index 4 cyclic shift pair index 510-----203----3024---6012345

[0196] If the UE detects SCI format 2-A with a cast type indicator field value of "01" or "10" as shown in Table 9, or if the UE detects SCI format 2-B or SCI format 2-A with a cast type indicator field value of "11" as shown in Table 10, the UE calculates the value m for calculating the cyclic shift α value. cs The UE applies one cyclic shift from among the cyclic shift pairs to the sequence used for PSFCH transmission.

[0197] HARQ-ACK Value0 (NACK)1 (ACK)Sequence cyclic shift06

[0198] HARQ-ACK Value0 (NACK)1 (ACK)Sequence cyclic shift0N / A

[0199] FIG. 10 illustrates resource units for measuring channel busy ratio (CBR) according to an embodiment of the present disclosure. The embodiment of FIG. 10 may be combined with various embodiments of the present disclosure.

[0200] Referring to FIG. 10, CBR may refer to the number of subchannels in which the RSSI (Received Signal Strength Indicator) measurement result value is higher than a preset threshold value when the terminal measures the RSSI per subchannel for a specific period (e.g., 100 ms). Alternatively, CBR may refer to the ratio of subchannels in which the RSSI measurement result value is higher than a preset threshold value among the subchannels in the specific period. For example, in the embodiment of FIG. 10, assuming that the hatched subchannels are subchannels in which the value is higher than a preset threshold value, CBR may refer to the ratio of the hatched subchannels in the 100 ms period. Additionally, the terminal may report the CBR to the base station.

[0201] For example, when PSCCH and PSSCH are multiplexed in the frequency domain, the terminal can perform one CBR measurement for one resource pool. Here, if PSFCH resources are configured or configured in advance, the PSFCH resources can be excluded from the CBR measurement.

[0202] Furthermore, congestion control that considers the priority of traffic (e.g., packets) may be required. For this purpose, for example, the terminal may measure the channel occupancy ratio (CR). Specifically, the terminal may measure the channel occupancy ratio (CBR), and based on the CBR, the terminal may determine the maximum value (CRlimitk) of the channel occupancy ratio (Channel occupancy ratio k, CRk) that traffic corresponding to each priority (e.g., k) may occupy. For example, the terminal may derive the maximum value (CRlimitk) of the channel occupancy for each traffic priority based on a pre-determined table of CBR measurements. For example, for traffic with a relatively high priority, the terminal may derive a relatively large maximum value of the channel occupancy. Thereafter, the terminal may perform congestion control by limiting the sum of the channel occupancies of traffic with a priority k lower than i to a certain value or less. Using this method, traffic with a relatively low priority may be subject to a stronger channel occupancy limit.

[0203] In addition, the terminal can perform SL congestion control by using methods such as adjusting the size of transmission power, dropping packets, deciding whether to retransmit, and adjusting the size of transmission RB (MCS adjustment).

[0204] Table 11 shows an example of SL CBR and SL RSSI.

[0205] SL CBRDefinitionSL Channel Busy Ratio (SL CBR) measured in slot n is defined as the portion of sub-channels in the resource pool whose SL RSSI measured by the UE exceed a (pre-)configured threshold sensed over a CBR measurement window [n-a, n-1], wherein a is equal to 100 or 100·2 μslots, according to higher layer parameter sl-TimeWindowSizeCBR.Applicable forRRC_IDLE intra-frequency,RRC_IDLE inter-frequency,RRC_CONNECTED intra-frequency,RRC_CONNECTED inter-frequencySL RSSIDefinitionSidelink Received Signal Strength Indicator (SL RSSI) is defined as the linear average of the total received power (in [W]) observed in the configured sub-channel in OFDM symbols of a slot configured for PSCCH and PSSCH, starting from the 2nd OFDM symbol.For frequency range 1, the reference point for the SL RSSI shall be the antenna connector of the UE. For frequency range 2, SL RSSI shall be measured based on the combined signal from antenna elements corresponding to a given receiver branch. For frequency range 1 and 2, if receiver diversity is in use by the UE, the reported SL RSSI value shall not be lower than the corresponding SL RSSI of any of the individual receiver branches.Applicable forRRC_IDLE intra-frequency,RRC_IDLE inter-frequency,RRC_CONNECTED intra-frequency,RRC_CONNECTED inter-frequency.

[0206] Referring to Table 11, the slot index may be based on the physical slot index.

[0207] Table 12 shows an example of SL CR (Channel occupancy ratio).

[0208] DefinitionSidelink Channel Occupancy Ratio (SL CR) evaluated at slot n is defined as the total number of sub-channels used for its transmissions in slots [na, n-1] and granted in slots [n, n+b] divided by the total number of configured sub-channels in the transmission pool over [na, n+b].Applicable forRRC_IDLE intra-frequency,RRC_IDLE inter-frequency,RRC_CONNECTED intra-frequency,RRC_CONNECTED inter-frequency

[0209] NOTE 1: a is a positive integer and b is 0 or a positive integer. a and b depend on the upper-layer parameter sl-TimeWindowSizeCR, b < (a+b+1) / 2, so a+b+1 = 1000 or 1000·2. u The slots are determined by the UE implementation, and n+b must not exceed the last transmission opportunity of the grant for the current transmission.

[0210] NOTE 2: SL CR is evaluated for each (re)transmission.

[0211] NOTE 3: When evaluating SL CR, the UE shall assume that the transmission parameters used in slot n are reused according to the existing grant(s) in slot [n+1, n+b] without dropping packets.

[0212] NOTE 4: Slot index is based on physical slot index.

[0213] NOTE 5: SL CR can be calculated by priority level.

[0214] NOTE 6: A resource is considered approved if it is a member of a selected sidelink grant.

[0215] Meanwhile, in the sidelink, carrier aggregation (CA) operations may be supported. For example, sidelink carrier (re)selection, synchronization of aggregated carriers, handling of limited capabilities, power control for simultaneous sidelink transmissions, and / or packet duplication may be supported in the sidelink CA operations. For example, this functionality may be backward compatible with respect to: For example, a Rel-16 / Rel-17 UE may receive PSCCH / PSSCH and (if SL HARQ is enabled in SCI) receive Rel-18 sidelink broadcast / groupcast transmissions using CA for the carrier that transmits the corresponding sidelink HARQ feedback.

[0216] Meanwhile, when operating SL unicast based on multiple carriers, unlike when using a single carrier, the SL RLF declaration criteria (for SL unicast sessions) need to be newly defined. Furthermore, it is necessary to prevent the AGC (automatic gain control) problem that occurs due to transmission and reception based on multiple carriers (e.g., PSCCH / PSSCH transmission and reception, PSFCH transmission and reception, etc.). According to various embodiments of the present disclosure, a method for performing communication based on carrier aggregation and a device supporting the same are proposed.

[0217] For example, in the present disclosure, a TX UE may be interpreted as a UE performing data transmission (e.g., PSCCH / PSSCH) (to a (target) RX UE), and / or a UE performing SL CSI-RS (and / or SL CSI Report Request Indicator) transmission (to the (target) RX UE), and / or a UE performing (predefined) RS transmission (e.g., PSSCH DM-RS) (and / or SL (L1) RSRP Report Request Indicator) to be used for SL (L1) RSRP measurement (to the (target) RX UE), and / or a UE transmitting a (control) channel (e.g., PSCCH, PSSCH) and / or an RS (e.g., DM-RS, CSI-RS) (on the (control) channel) to be used for SL RLM (radio link monitoring) (and / or SL RLF (radio link failure)) operation (of the (target) RX UE).

[0218] For example, in the present disclosure, an RX UE may be interpreted as a UE transmitting SL HARQ feedback (to a TX UE) based on whether decoding of data received from a TX UE is successful (and / or whether detection / decoding of a PSCCH (related to PSSCH scheduling) transmitted by the TX UE is successful), and / or a UE performing SL CSI transmission (to the TX UE) based on an SL CSI-RS (and / or an SL CSI Report Request Indicator) received from the TX UE, and / or a UE transmitting an SL (L1) RSRP measurement value (to the TX UE) based on an (predefined) RS (and / or an SL (L1) RSRP Report Request Indicator) received from the TX UE, and / or a UE performing its own data transmission (to the TX UE), and / or a UE performing an RLM (and / or RLF) operation based on a (predefined) (control) channel and / or an RS (on the (control) channel) received from the TX UE.

[0219] For example, in the present disclosure, the term "PSCCH" may be extended to mean SCI (and / or first SCI (or second SCI) and / or PSSCH). For example, in the present disclosure, the term "SCI" ​​may be extended to mean PSCCH (and / or first SCI (or second SCI) and / or PSSCH). For example, in the present disclosure, the term "PSSCH" may be extended to mean second SCI (and / or PSCCH).

[0220] For example, in this disclosure, the term "configuration (or definition)" may be interpreted as being (pre-)configured (resource pool-specifically) from a base station (or network) (via pre-defined signaling (e.g., SIB, MAC, RRC)). For example, in this disclosure, the term "configuration (or definition)" may be interpreted as being specified between terminals via pre-defined signaling (e.g., PC5 RRC). For example, in this disclosure, the term "RLF" may be mutually extended to be interpreted as at least one of OOS (out-of-synch) or IS (in-synch). For example, in this disclosure, the term "RB" may be mutually extended to be interpreted as subcarrier. For example, in this disclosure, the term "packet (or traffic)" may be mutually extended to be interpreted as TB (transport block) (or MAC PDU). For example, in this disclosure, the term "CBG (code block group) (or CG)" may be mutually extended to be interpreted as TB. For example, in the present disclosure, the term "source ID" can be extendedly interpreted as "destination ID". For example, in the present disclosure, the term "L1 ID" can be extendedly interpreted as "L2 ID". For example, in the present disclosure, the term "retransmission resource reservation / selection" can be extendedly interpreted as reservation / selection of potential retransmission resources, the actual use of which is determined based on SL HARQ feedback information. For example, in the present disclosure, the term "sub-selection window" can be extendedly interpreted as selection window (and / or a set of resources in advance within the selection window). For example, in the present disclosure, "SL mode 1 operation" can mean a case where a base station directly schedules SL transmission resources of a terminal through predefined signaling (e.g., DCI), and "SL mode 2 operation" can mean a case where a terminal independently selects SL transmission resources from a predefined resource pool (from a base station or a network).For example, in this disclosure, the term "dynamic grant" can be extended to mean a configured (or SPS) grant (or a combination of a configured (or SPS) grant and a dynamic grant). For example, in this disclosure, the term "configured grant" can be extended to mean a "type 1 configured grant" (or a "type 2 configured grant"). For example, in this disclosure, the term "channel" can be extended to mean a "signal". For example, in this disclosure, the term "cast (type)" can be extended to mean "unicast (and / or groupcast and / or broadcast)". For example, in this disclosure, the term "resource" can be extended to mean "slot" (or "symbol"). For example, in the present disclosure, the term "priority" may be extended to mean "logical channel prioritization (LCP)" (and / or "latency" and / or "reliability" and / or "minimum required communication range" and / or "ProSe Per-Packet Priority (PPPP)" and / or "priority" and / or "SLRB" and / or "QoS profile / parameter" and / or "requirement").

[0221] For example, for SL TX using SL CA, intra-band contiguous CA (supported in REL-15 RAN4), intra-band non-contiguous CA, and / or inter-band CA may be supported. Here, for example, the possibility of simultaneous transmission / reception between inter-band carriers may be a UE capability.

[0222] For example, for SL RX using SL CA, intra-band contiguous CA (supported in REL-15 RAN4), intra-band non-contiguous CA (supported in REL-15 RAN4), and / or inter-band CA may be supported. Here, for example, the possibility of simultaneous transmission / reception between inter-band carriers may be a UE capability.

[0223] For example, the spectrum combinations relevant for SL operation could be only intelligent transport system (ITS) bands (supported by REL-15 RAN4), only licensed bands, or both ITS bands and licensed bands.

[0224] For example, limited capability could include simultaneous SL TX (considered in REL-15) or simultaneous SL RX.

[0225] For example, service types / types can be mapped by carrier. This can be supported in REL-15. For example, service types / types can be mapped by SL BWP. In this case, for example, if there is one SL BWP per carrier, it can be considered the same as the per-carrier form. For example, there can be multiple SL BWPs within a carrier.

[0226] For example, the numerology (e.g., SCS) may be different between SL CA carriers / BWPs. For example, especially in the case of intra-band CA, the numerology (e.g., SCS) may be different between SL CA carriers / BWPs.

[0227] For example, dynamic UL switching may change the supportable combinations between SLs and Uu, which may impact SL operation.

[0228] For example, if the numerologies are different between SL CA carriers / BWPs, there may be synchronization-related issues such as DFN (direct frame number) index mismatch between carriers / BWPs, and / or mismatch in the location / number of SLSS resources between carriers / BWPs (e.g., this issue can be addressed by configuration restrictions), and / or there may be synchronization accuracy issues (e.g., in the case of SLs, due to the absence of transmissions such as Uu's TRX). For example, if the numerologies are different between SL CA carriers / BWPs, handling of half-duplex / limited TX capabilities may become more difficult. For example, if the numerologies are different between SL CA carriers / BWPs, power sharing may become more difficult since transmissions of different TTI lengths may overlap, and implementation limitations may lead to more frequent events where some transmission regions are dropped.

[0229] For example, an additional enhancement considering the limited TX capability (for convenience of discussion, the number of carriers / BWPs that a REL-18 UE can transmit on simultaneously is named 'NUM_CC_SIMTX') can be proposed as follows.

[0230] For example, when the number of carriers / BWPs requiring simultaneous PSFCH transmission is greater than NUM_CC_SIMTX, PSFCH transmission prioritization may be performed within the carrier / BWP first, and PSFCH transmission prioritization may be performed between carriers / BWPs next. For example, PSFCH transmission prioritization may be performed within the carrier / BWP. For example, PSFCH transmission prioritization may be performed between carriers / BWPs. For example, the highest priority among the priorities of the service(s) (of which it is interested or all) mapped to the carrier / BWP and / or the highest priority among the priorities of the PSFCH(s) currently requiring transmission per carrier / BWP and / or the carrier / BWP on which PSFCH transmission of a greater number of ACK information (and / or NACK information) is performed may be considered as having a relatively high priority.

[0231] For example, PSFCH transmissions satisfying the conditions below may, exceptionally, be assumed to have the highest priority, or may be set (in advance).

[0232] Example) REL-16 / 17 or PSFCH transmission related to pre-defined service type / kind (e.g. release indicator can be added on REL-18 SCI or MAC CE)

[0233] Example) Pre-defined message types (e.g. SCCH, MAC CE)

[0234] Example) (Distance-based) PSFCH transmission only related to NACK feedback

[0235] Example) PSFCH transmission related to a pre-configured cast type (e.g., group cast)

[0236] For example, in case of unicast, the PSFCH half-duplex / limited capability issue can be mitigated by exchanging information between REL-18 UEs (e.g., supportable (transmit / receive) band combinations, simultaneous transmit / receive capability information, preferred carriers of peer UEs considering their own receive band combinations, etc.). This can be especially useful when considering novel behaviors such as PSFCH feedback from peer UEs. For example, preferred (or supported) band combination information of (peer UEs) can be exchanged / reported between UEs (e.g., using inter-UE coordination (IUC) containers - (non)preferred or pre-selected carrier information, etc.) or between UEs and base stations (e.g., in Mode 1). For example, a Mode 1 TX UE can report to its base station the RX bands / carriers supported by the peer UE, and the base station can take this into account to efficiently determine the bands / carriers to which the Mode 1 transmission resources of the TX UE are allocated. For example, when signaling IUC information, resources exceeding CA capabilities may be signaled as non-preferred resources.

[0237] For example, different types of PSFCH carriers / BWPs linked to PSCCH / PSSCH carriers / BWPs may be supported. This may be useful, for example, for unicast operations between REL-18 UEs. Additionally, a REL-18 dedicated resource pool or PSFCH pool may be configured. However, this may not be readily utilized for communications with legacy UEs.

[0238] For example, transmission resource (re)selection considering PSFCH transmission / reception may be performed. For example, when transmission resource (re)selection is performed, if information on the time point at which PSFCH transmission / reception is required on the same carrier / BWP is available, a slot at which PSFCH transmission is required may be prioritized. For example, when transmission resource (re)selection is performed, if information on the time point at which PSFCH transmission / reception is required on a different carrier / BWP is available, on the carrier / BWP where transmission resource (re)selection is performed, a slot overlapping with a time point at which PSFCH transmission is required on another carrier / BWP and a (previous) / next slot may be deprioritized, or a slot overlapping with a time point at which PSFCH reception is required on another carrier / BWP may be deprioritized. For example, considering the priority of data related to resource (re)selection, unsatisfactory requirements of related data (e.g., PDB) due to delay in resource (re)selection, etc., resource (re)selection at a time point overlapping with a PSFCH RX slot may be allowed. For example, in this case, the PSFCH RX operation may be omitted. For example, when the overlapping channels between carriers are different (or the same) (PSCCH / PSSCH + PSFCH) and / or the TX or RX are different (or the same) between carriers (TX + RX, TX + TX, RX + RX), as a solution to the above problem, a form in which the REL-16 / 17 rules within the carrier may be preferentially applied and prioritization between carriers may be performed based on the result may be considered. For example, similar to re-evaluation / preemption, reselection of selected / reserved resources overlapping with the positions of PSFCH transmit / receive resources may be triggered. For example, the (non)priority criteria may be defined differently depending on channel type / type, cast type, service / message type / type, etc.

[0239] For example, TX carrier reselection may be performed considering PSFCH transmission. For example, when carrier reselection is performed, if information regarding the time at which PSFCH transmission is required is available, priority may be given to supportable PSFCH transmissions that are required.

[0240] For example, the periodicity / location of PSFCH resources can be restricted to be set identically between carriers. For example, even when the numerologies differ between carriers, the periodicity / location of PSFCH resources can be restricted to be set identically between carriers. For example, this can alleviate the problem of PSSCH reception being omitted during a slot period on another carrier (partially) overlapping with PSFCH transmission on a specific carrier.

[0241] For example, SL DRX operation may be supported in SL CA. For example, a per-carrier resource selection priority scheme (e.g., per-destination) considering the SL DRX pattern (e.g., active time) may be considered. For example, the linked PSFCH resource may be semi-statically / dynamically configured / adjusted to be located outside the active time. For example, to achieve this, the location of the selected PSSCH transmission resource (linked with the PSFCH) may be adjusted. For example, the SL DRX operation may be disabled when the PSFCH transmission overlaps with the active time.

[0242] For example, to enhance Mode 1 PUCCH, it is necessary to support an operation in which SL HARQ information related to PSFCH received on multiple carriers / BWPs is simultaneously reported via PCELL (or PSCELL or PUCCH CELL). For example, in particular, when the PSFCH period (and / or numerology) is different for each carrier / BWP, PSFCH information of the carrier that serves as a reference when configuring PUCCH resources may be signaled, and / or carrier information related to SL HARQ information included on the PUCCH may be included, and / or PUCCH resources may be configured for each carrier, but the length of the time window in which the PUCCH is multiplexed may be configured, and / or the payload size may be determined during semi-static codebook operation. For example, PSFCH information for each carrier / BWP may be preferentially merged, and these may be ultimately merged between carriers / BWPs. For example, in this case, the merging order between carriers / BWPs may be configured in advance.

[0243] For example, with respect to Mode 1 CG, Mode 1 operation may be enabled in SCG, and / or whether there is one or multiple Mode 1 PUCCH cells (e.g., different PUCCH cells per SL carrier set) may be configured, and the SL mode type may be configured differently between MCG and SCG.

[0244] For example, in mode 1 resource scheduling, the base station may not be able to determine on which carrier the UE wants to perform which service packet transmission based solely on the SR / BSR (e.g., LCH / destination ID) information. Therefore, for example, additional carrier information on which the UE wants to perform packet transmission may be included in the BSR, or additional carrier (or destination) information may be mapped for each SR resource. For example, signaling for mapping LCH information per carrier may be defined.

[0245] For example, with respect to SL session management, the permissible unit of operation of a single unicast link may be a single carrier / BWP or multiple carriers / BWP.

[0246] For example, in the case of unicast, an agreement procedure may be required between UEs regarding which carriers / BWPs to add / release (or activate / deactivate). For example, PC5 RRC signaling may be used for this purpose, or carrier / BWP-specific cause values ​​may be introduced.

[0247] For example, in the case of groupcast, carrier selection between TX / RX UEs can be efficiently performed through exchange of IUC (e.g., preferred / supported carrier information, radio link failure occurrence carrier information).

[0248] For example, unicast link parameters can be configured on a carrier / BWP basis. For example, unicast link parameters can be configured commonly across carriers / BWPs. For example, parameters related to SL communication on one carrier can be configured through another carrier.

[0249] For example, packet duplication in an SL unicast session can be established through negotiation between UEs. In the present disclosure, an SL unicast session may be referred to as an SL PC5 RRC connection.

[0250] For example, when an SL unicast session controls multiple carriers / BWPs, discontinuous transmission (DTX) counting may be performed for SL radio link failure handling. For example, the DTX counting may be in a form that considers the sum of the number of DTX occurrences on multiple carriers / BWPs. For example, the DTX counting may be in a form that considers the number of DTX occurrences per carrier / BWP. In this case, for example, when the number of DTX occurrences continuously on a specific carrier / BWP exceeds a threshold, the carrier / BWP may be deactivated / released. For example, the DTX counting may be in a form that considers only the number of DTX occurrences on a carrier / BWP on which session establishment related signaling has been / is being transmitted.

[0251] For example, if a radio link failure (e.g., carrier failure) occurs in some carriers / BWPs among multiple carriers / BWPs, the SL unicast session can be maintained. In this case, for example, radio link monitoring and / or radio link failure operations can be performed across carriers. Accordingly, for example, if a radio link failure (e.g., carrier failure) occurs in some carriers / BWPs among multiple carriers / BWPs, the SL unicast session can be maintained, and if a radio link failure (e.g., carrier failure) occurs in all carriers / BWPs among multiple carriers / BWPs, the SL unicast session can be terminated.

[0252] For example, if a radio link failure (e.g., carrier failure) occurs in some carriers / BWPs among multiple carriers / BWPs, the SL unicast session may be terminated. In this case, for example, radio link monitoring and / or radio link failure operations may be performed on a per-carrier basis.

[0253] For example, PC5 RRC signaling, radio link failure indicator, recovery signaling, etc. may be transmitted over multiple carriers (rather than a single predefined carrier (e.g., the carrier used for SL unicast link setup signaling exchange)). For example, in Mode 1, when reporting a radio link failure occurrence, related carrier / BWP information may also be transmitted. For example, carrier / BWP information performing unicast operation with a peer UE may be reported to the base station. For example, when operating in Mode 1 with a peer UE, information about a preferred band combination of the peer UE may be reported to the base station.

[0254] For example, Mode 1 BSR / SR can be reported / configured on a per-carrier basis (e.g., carrier indicator).

[0255] For example, in the case of SL CA, in the LCP procedure, the LCH data included in the MAC PDU generation can be determined by considering the carrier / BWP related numerology.

[0256] For example, multiple BWPs with different numerologies can be set for each carrier, and a carrier can be selected based on a valid BWP selection, taking into account the requirements of LCH data.

[0257] For example, if the numerology differs between the UL and SL, the SL may be deactivated. In this case, carrier reselection may be triggered, for example. Alternatively, an SL BWP with the same numerology as the UL on the same carrier may be reselected, for example.

[0258] For example, inter-band asynchronous CA form may be supported in REL-18.

[0259] For example, in case of unicast SL CA, a TX / RX carrier may be designated for PC5-S signaling or PC5-RRC message. For example, the TX / RX carrier may be a primary carrier or a lowest CBR carrier. For example, the TX / RX carrier may be designated by SIB or dedicated RRC. For example, the TX / RX carrier may be designated by a discovery message from a TX UE to a RX UE. For example, terminals may perform TX / RX for unicast link setup based on the designated carrier. In this case, for example, a separate resource pool may be configured.

[0260] For example, the RX UE needs to be aware of the carrier reselection of the TX UE. For example, the service-to-carrier mapping can be established in unicast or through negotiation between the terminals. For example, even in legacy unicast, the TX UE can select a single carrier based on the service-to-carrier mapping. For example, this information can also be extended to the unicast of SL CA. For example, in a CA situation, if one service is mapped to multiple carriers (C1, C2, C3, C4), there is a problem that the RX UE does not know which carrier the TX UE will select. For example, if the RX UE can obtain the service information during the PC5-S unicast link setup, the RX UE can monitor all of C1, C2, C3, and C4 based on the service frequency mapping.

[0261] Step 1: TX UE can be configured with C1, C2, C3, C4 through RRC of base station.

[0262] For example, the TX UE can determine the first activated CC (C1, C2, C3) and inform the RX UE of it via PC5-RRC. For example, the TX UE can transmit an SL MAC CE or SCI for activating (C1, C2, C3) to the RX UE. For example, (C1, C2, C3) can be selected considering service mapping. For example, this can be helpful in terms of RX capability and power saving.

[0263] For example, a TX UE can set C1, C2, C3, and C4 to the RX UE via RRC.

[0264] For example, the RX UE can select the RX carrier. For example, considering only unicast, the RX UE can always monitor C1, C2, C3, and C4. For example, considering only unicast, the RX UE can only monitor (C1, C2, C3). In this case, a problem may occur if the TX UE moves only to C4 during carrier reselection.

[0265] For example, the RX UE can select a TX carrier.

[0266] For example, considering only unicast, the RX UE can be configured with C1, C2, C3, and C4 through the RRC of the base station. For example, a connected RX UE can request C1, C2, C3, and C4 from the base station.

[0267] For example, considering only unicast, the RX UE can set the carrier among C1, C2, C3, C4 selected by the TX UE. For example, the RX UE can set the unicast TX carrier among C1, C2, C3, C4 that the TX UE notified through RRC. For example, the carrier notified by the TX UE can be the TX carrier of the TX UE or the RX carrier of the TX UE. For example, the RX UE can report C1, C2, C3, C4 information to the base station.

[0268] For example, considering only unicast, the TX UE can inform the RX UE of the possible CC combinations, and the RX UE can select a CC combination. For example, the TX UE can inform the RX UE of the possible CC combinations such as (C1, C2, C3), (C1, C2, C3, C4), (C3, C4, C5), etc., and the RX UE can select a CC combination.

[0269] For example, if there is another unicast or another GC / BC carrier, the RX UE can transmit the carrier preference to the TX UE. For example, the RX UE can request the TX UE to select the TX resource based on C3, C4, C5, C6. For example, if the RX UE is currently TXing or RXing based on C5, C6, the RX UE can request the TX UE to select the TX resource based on C3, C4, C5, C6. For example, the RX UE can inform the TX UE that the RX of the combination (C1, C2, C3) is not supported. In this case, for example, the RX UE can inform the TX UE of the possible combinations.

[0270] Step 2: The TX UE may perform SL mode 2 carrier reselection. For example, the TX UE may select carriers (C1, C2, C3) to carriers (C2, C4).

[0271] For example, in SL mode 1, the base station can enable / disable via DL MAC CE. For example, in SL mode 1, the base station can enable / disable per destination via DL MAC CE. For example, this can affect SL CG enable / disable or PUCCH A / N codebook configuration. For example, the base station can control TX power saving of the TX UE (e.g., RF off for inter-band CA) and power saving of the RX UE. For example, the TX UE can be enabled / disabled immediately after the application time. For example, in LTE SL CA, the UE can report carrier information per destination.

[0272] Step 3: The TX UE may transmit SL MAC CE or SCI to the RX UE for activation / deactivation.

[0273] For example, a TX UE may indicate (C2, C4). For example, there may be an advantage if the TX UE indicates (C2, C4) before finally performing carrier reselection. For example, if the (C2, C4) indication is acknowledged late and the reselection is CBR-based, the TX UE may briefly maintain (C1, C2, C3). For example, if the (C2, C4) indication is acknowledged late and the reselection is sidelink failure-based, a definition of a default carrier may be required.

[0274] For example, when the RX UE receives an activation / deactivation from the TX UE, the RX UE may switch to (C2, C4). For example, the RX UE may transmit an ACK (PSFCH or MAC CE based ACK or SCI based ACK) for the activation / deactivation to C2 or C4.

[0275] For example, carrier reselection of an RX UE may operate similarly to carrier reselection of a TX UE. For example, the TX carrier or the RX carrier of the TX UE may be preferentially selected as the TX carrier of the RX UE. For example, the TX UE may report its preferred TX carrier of the RX UE using the IUC MAC CE, etc. In this case, for example, the RX UE may select / reselect the TX carrier based on the carrier information of the IUC.

[0276] For example, the TX UE and the RX UE can perform cell indexing. For example, the cell index can be specified via a PC5-RRC message. For example, absolute radio frequency channel number (ARFCN)-to-cell index mapping can be used.

[0277] For example, there may be N_F PSFCH carriers for N_S PSSCH carriers for unicast, where, for example, N_F may be greater than or equal to 1 and less than or equal to N_S.

[0278] For example, when PSSCH carrier reselection is performed, PSFCH carrier reselection may also be triggered. In the following embodiment, carrier reselection may be performed as follows: (C1, C2, C3) -> (C2, C4) -> (C1, C3).

[0279] For example, as in the past, the PSFCH carrier may be reselected according to TX carrier reselection. For example, from a unicast / groupcast perspective, it may be advantageous if the TX carrier of the TX UE and the TX carrier of the RX UE are aligned. Otherwise, it may cause problems in feedback transmission due to the TX capability limitation of the RX UE. For example, if PSFCH transmission for C1 is possible, a feedback-enabled channel may be mapped, and if PSFCH transmission for C2 is not possible, a feedback-disabled channel may be mapped. For example, if carrier reselection is initiated for a specific feedback-enabled logical channel, carrier reselection may be performed considering the PSFCH transmission capability of the RX UE and / or a carrier with PSFCH transmission resources. For example, if carrier reselection is initiated for a specific feedback-disabled logical channel, carrier reselection may be performed without having to consider the PSFCH transmission capability of the RX UE. For example, feedback transmission may be required for carriers transmitted by legacy UEs and for groupcast transmissions. In this case, such carriers may be preferentially selected as TX carriers. For example, based on a TX carrier prioritization scheme, simultaneous transmission of multiple PSFCHs or simultaneous transmission of PSSCH / PSFCHs may be performed.

[0280] For example, if it was previously C1 PSFCH, it can be switched to C2 or C4. For example, C2 or C4 can be indicated by the TX UE (via SCI or MAC CE). In this case, it can be advantageous to indicate the PSFCH carrier, for example, with a scheduling SCI. For example, C2 or C4 can be indicated by the RX UE (via MAC CE). In this case, for example, if the TX UE indicates activation / deactivation, the RX UE can indicate the PSFCH carrier, for example, with a confirmation SCI or MAC CE.

[0281] For example, it can always be set to C1, regardless of carrier reselection. For example, the TX UE can semi-statically configure / change it via RRC. For example, the base station can configure / change it via RRC.

[0282] For example, it can be set to the lowest C2 or the highest C4 during carrier reselection. In this case, for example, it can be set based on the criteria for activating / deactivating the TX UE.

[0283] For example, when PSSCH carrier reselection is performed, it is necessary to reconstruct multiplexed HARQ-ACK information of multiple carriers in PSFCH transmission. In the following embodiments, carrier reselection may be performed as follows: (C1, C2, C3) -> (C2, C4) -> (C1, C3). For example, the carrier order in the HARQ-ACK information may be based on a carrier index specified by the TX UE via RRC, and / or a carrier index based on MAC CE activation / deactivation of the TX UE, and / or a carrier index based on a carrier index specified by the base station via RRC. For example, a long format for Rel-18 PSFCH may not be supported.

[0284] For example, multiple PSFCH transmissions may be supported in Rel-18 SL CA. For example, in the case of single carrier-multiple PSFCH mapping, the RX UE may transmit multiple PSFCHs based on CDM / TDM / FDM. For example, in the case of multiple carrier-multiple PSFCH mapping, the RX UE may transmit multiple PSFCHs based on CDM / TDM / FDM. For example, there may be a PSFCH priority issue for both the single carrier-multiple PSFCH mapping scheme and the multiple carrier-multiple PSFCH mapping scheme.

[0285] For example, in the case of packet duplication, broadcast / groupcast packet duplication may not be a problem for legacy terminals. For example, in the case of SL mode 2, the carrier for packet duplication may change depending on carrier reselection. In this case, for example, the primary path may change based on the lowest carrier index and / or the lowest CBR, and the secondary path may change based on the lowest carrier index and / or the lowest CBR among the remaining carriers that are not the primary path. For example, the current Uu duplication enable / disable MAC CE can only support enable / disable per DRB ID. For example, in the case of SL mode 1, the base station can transmit the SL duplication enable / disable MAC CE to the TX UE. In this case, for example, a destination index field may be added, and / or the primary carrier may be designated per destination, per SLRB, or per priority, and / or CBR measurement information or priority may be designated per carrier index. For example, CBR measurement information or priority per carrier index can be utilized to designate a primary path, and / or CBR measurement information or priority per carrier index can be utilized in LCP. For example, the TX UE can send an SL replication enable / disable MAC CE to the RX UE. For example, this can be useful in unicast, since the TX UE can establish the bearer, but it can be difficult in groupcast / broadcast, since (like LTE) replication can be determined based on the logical channel ID value. For example, (like LTE) replication can be indicated per SLRB or per priority, and / or the carrier combination for replication can be indicated per SLRB or per priority.

[0286] For example, carrier reselection may be performed upon SL failure. For example, SL failure may be a per-UE (per bearer mapped to carrier(s)) RLC retransmission and / or a per-carrier HARQ feedback and / or a per-UE reset failure and / or a per-UE (per bearer mapped to carrier(s)) IP check failure and / or a PC5-S keep-alive signal.

[0287] For example, SL HARQ feedback-based RLM can be performed. For example, multiple RLMs can be performed on each carrier. For example, only one RLM can be performed on one carrier. Here, for example, the carrier can be a carrier on which a PC5-RRC connection is established and / or a carrier indicated by a TX UE. For example, one RLM can be performed for an aggregated carrier. For example, this is a different operation from Uu, and carrier reselection needs to be reflected, and can be considered in the case of one PSFCH carrier for multiple PSSCH carriers.

[0288] For example, a primary sidelink carrier may be established. In this case, PC5 RLM may be performed, for example, similar to Uu.

[0289] For example, in case of unicast, the TX UE can inform the RX UE of an SL failure (of a specific carrier). In this case, for example, in case of an SL failure of a specific carrier, it is necessary to not select that specific carrier as a TX carrier.

[0290] For example, in the case of unicast, the TX UE may not inform the RX UE of an SL failure (of a specific carrier). In this case, for example, the PC5-RRC connection may be released due to an SL failure as in the past.

[0291] For example, an SL failure may occur for one carrier (e.g., an SL carrier on which an RLC retransmission failure or an SL carrier on which an HARQ feedback based SL failure occurred). In this case, for example, an SL mode 2 TX UE may perform carrier reselection to a primary / default carrier (if the RX UE is not monitoring all carriers), and an SL mode 2 TX UE may perform carrier reselection to any carrier (configured by PC5-RRC) (if the RX UE is monitoring all carriers). Here, for example, multiple default carriers may be specified, and / or the RX UE may perform reception by switching to the default carrier upon detection of an SL failure.

[0292] For example, an SL failure may occur for a carrier (e.g., an SL carrier on a carrier where an RLC retransmission failure or an SL failure based on HARQ feedback has occurred). In this case, for example, an SL mode 1 TX UE may report this to the base station. The base station may, for example, reselect a carrier to activate / deactivate the SL carrier. For example, both the destination and the carrier where the SL failure occurred may be reported. For example, in SL mode 1, per-carrier RLM may be meaningful. This may, for example, prevent the base station from scheduling that carrier. However, in this case, for example, the UE may use that carrier for another destination.

[0293] For example, a TX UE may activate / deactivate a carrier while informing the RX UE of an SL failure. For example, carrier reselection may be performed such as (C1, C2, C3) -> (C2, C4). For example, a TX UE may activate / deactivate a carrier while informing the RX UE of an SL failure via a common active C2 or primary / default carrier. For example, an SL failure may be indicated via an RRC message or a MAC CE. For example, a carrier to switch to upon SL failure may be indicated, and / or the RX UE may switch reception to the indicated carrier. For example, if there is no indicated carrier, the RX UE may switch to a default carrier. For example, if there is no default carrier, the RX UE may switch to the lowest index or CBR carrier.

[0294] For example, if only the RX UE detects an SL failure, the RX UE may start a timer. For example, the RX UE may switch TX / RX to the primary / default carrier after the timer expires. For example, if there is no default carrier, the RX UE may switch to the lowest index or CBR carrier. After that, the PC5-RRC connection may be released, for example, according to conventional procedures.

[0295] For example, a MAC CE carrier can be designated. For example, a base station or TX UE can designate the SL carrier(s) on which the above / existing MAC CEs can be transmitted. For example, MAC CEs can be transmitted only on the primary carrier, or MAC CEs can be transmitted on the carrier with the lowest CBR. For example, a specific MAC CE can be transmitted on a specific carrier, and other MAC CEs (IUC MAC CEs) can be transmitted on any carrier.

[0296] For example, since a synchronization carrier is currently designated, the PSBCH can only be transmitted on the current synchronization carrier.

[0297] For example, a frequency can be input as a security input parameter of the SL AS. In this case, for example, the frequency can be the reference for the primary carrier. For example, the frequency on which PC5-S and PC5-RRC messages are exchanged can be designated as the primary carrier. For example, based on LTE CA, the primary carrier can be selected based on the lowest CBR. For example, if the primary carrier is reselected, there may be an issue of how to designate the primary carrier again. For example, the TX UE can reconfigure the primary carrier to the RX UE via RRC or designate it via MAC CE / SCI.

[0298] For example, in the case of groupcast SL CA, similar to the unicast method, MAC CE-based activation / deactivation of the base station / TX UE can be used. In this case, for example, confirmation ACK can be supported on a NACK-only basis or MAC CE-based basis.

[0299] For example, for broadcast SL CA, MAC CE-based activation / deactivation of TX UEs can be configured. For example, this may be difficult to coexist with legacy RX UEs, since the carrier where the legacy RX UE exists cannot be deactivated. For example, this may not be useful in a resource pool that coexists with legacy UEs, but it can be used in a Rel-18 resource pool. For example, broadcast SL CA can operate as much as possible like legacy LTE CA.

[0300] For example, for LTE SL CA operation, the UE may only report {destination index 0, LCG1, X}, and / or the base station may find out that both f1 and f2 are associated with this destination ID based on the sidelink UE information, and may provide resource grants on f1(XY) and f2(Y) to jointly carry data volume X, where Y may be a value between (0, X), for example. For example, the above LTE SL CA operation may also be applied to NR SL BSR.

[0301] For example, in the case of LTE / NR PDCP packet duplication, the LTE SL BSR and the NR SL BSR may indicate the buffer size for the same destination. In this case, for example, a 100% duplicate buffer size may be reported. In this case, for example, since both RATs receive the report, an over-allocation problem may occur if the schedulers are different. Alternatively, the buffer size may be preferentially reported (only one side reported) via the NR BSR or LTE BSR, for example, per destination, per LCG, or per UE. In this case, for example, the base station may configure NR or LTE or both. For example, since the NR / LTE schedulers may be different, reporting to only one RAT may allow only one RAT to schedule. For example, in the case where the buffer size is preferentially reported (only one side reported) via the NR BSR or LTE BSR per destination, per LCG, or per UE, the base station may determine the reporting target depending on the implementation situation of the LTE / NR base station. In this case, for example, the PDCP PDU of NR PDCP can be transmitted by LTE RLC / MAC.

[0302] For example, for SL CG, a TX UE can report preferred / non-preferred TX carriers (per destination). For example, the base station can configure an SL CG for a preferred TX carrier, and / or an SL CG for a non-preferred TX carrier can be disabled or released, and / or an SL CG-to-one or more destination mappings can be configured.

[0303] For example, for an SL carrier, one or more SL carrier-to-destination mappings may be established for LCP, and / or destinations or (current) SL carriers may be specified by DCI.

[0304] For example, when multiple PSFCHs are transmitted on a specific carrier, power splitting between carriers may be performed. In this case, for example, P_CMAX may be defined.

[0305] For example, when (re)selecting resources, actions / conditions can be defined that make FDM resource selection between carriers a lower priority.

[0306] For example, even if the SCS value is the same between carriers, in order to alleviate the AGC problem, the start symbol position / number of symbols, CP length, etc. may also be limited to be the same between carriers.

[0307] For example, when multiple TBs with different QoS profiles / destinations are transmitted simultaneously on multiple carriers, a SL DRX operation method can be defined.

[0308] For example, a DTX counting method and SL RLF final declaration conditions can be defined among multiple unicast-related carriers. For example, this can be limited to carriers agreed upon between terminals and / or carriers with the lowest index. For example, DTX counting and SL RLF final declaration can be performed only by considering carriers for which PSFCH resources are configured among multiple unicast-related carriers.

[0309] For example, when SL RLF counting is performed considering carrier(s) for which PSFCH resources are configured, carriers for which PSFCH resources are not configured may not be utilized for SL RLF declaration.

[0310] For example, in the case of packet replication, since PPPR is not defined in NR SL, the granularity of packet replication settings in NR SL CA can be set differently per RB, per LCH, per SRB / DBR, or per message type / content.

[0311] For example, to perform packet duplication, there may be conditions other than PPPR. For example, the network may set packet duplication operation permission, and the UE may decide whether to perform actual packet duplication based on whether the preset conditions are satisfied. In this case, the UE may decide whether to perform actual packet duplication based on, for example, CBR, packet size, QoS profile (wherein parameters such as latency may be considered as additional conditions), priority, number of PSFCH NACK feedback / DTX occurrences, SL CSI information, and whether SL RLF occurs.

[0312] For example, a UE may request a packet duplication operation from a base station or a peer UE. For example, a packet duplication operation may be requested when a RX UE repeatedly fails to decode received data and / or an SL RLF occurs.

[0313] For example, in the case of LTE SL CA, service mapping can be performed on a carrier-by-carrier basis. For example, in NR SL CA, service mapping can also be performed on a carrier-by-carrier basis.

[0314] For example, the granularity of a PC5 RRC reset operation (e.g., RB, SL DRX) can be defined. For example, the granularity of a PC5 RRC reset operation (e.g., RB, SL DRX) can be per carrier. For example, the granularity of a PC5 RRC reset operation (e.g., RB, SL DRX) can be per PC5 RRC connection. For example, the transmission of a PC5 RRC reset related complete message can be limited to the carrier on which the PC5 RRC reset was received. For example, the granularity of a PC5 RRC reset related T400 timer setting can be defined.

[0315] For example, transmission / reception of specific messages (e.g., PC5 RRC messages, SRB messages, etc.) may be restricted by carrier. For example, the carriers on which specific messages are transmitted / received may be selected / restricted based on carrier index. For example, the carriers on which specific messages are transmitted / received may be selected / restricted based on the carrier's CBR measurement value, the number of NACK occurrences, the SL CSI value, etc.

[0316] For example, conditions for triggering carrier reselection or resource reselection conditions (e.g., whether SL RLF occurs) can be defined.

[0317] For example, if an RLF occurs for unicast, resource selection can be performed excluding multiple linked carriers. Furthermore, for example, when a pre-set timer expires, the multiple carriers can be re-available for resource selection.

[0318] For example, when reselecting a carrier, if a packet to be transmitted is SL HARQ ENABLED, the carriers for which PSFCH resources are set may be selectively selected using the CBR measurement value. For example, among the carriers for which HARQ feedback ENABLED packet transmission is allowed, only the carriers for which PSFCH resources are set may be filtered. And, for example, among the carriers for which a CBR measurement value is lower than a CBR threshold value linked to the packet priority among the carriers, the carrier for which the lowest CBR measurement value is set may be selected.

[0319] For example, under an SL CA environment, when a terminal transmits sidelink UE information to a base station, a carrier index may be included in the sidelink UE information.

[0320] For example, a latency bound can be established between unicast UEs (e.g., via SL CSI and / or IUC). In this case, for example, the granularity of the latency bound can be per PC5 RRC connection. Alternatively, for example, the granularity of the latency bound can be per carrier. For example, even though SL CSI triggering / feedback is performed on a per-carrier basis, the latency bound can be established on a per-PC5 RRC connection basis.

[0321] For example, in the case of IUC operation, IUC request / IUC information transmission (SCHEME 1) and collision indicator transmission for UE-B resource reservation (SCHEME 2) may be limited to a carrier basis.

[0322] For example, CBR measurements can be performed on a carrier basis, and the carrier index can be reported together with the report to the base station.

[0323] For example, when an SL RLF occurs, the SL RLF occurrence indicator and the carrier index can be reported together to the base station or upper layer of the terminal (e.g., when reporting a PC5 link identifier).

[0324] For example, PSFCH time resources may overlap between SL CA carriers.

[0325] FIG. 11 illustrates an example of overlapping PSFCH time resources between multiple carriers, according to one embodiment of the present disclosure. The embodiment of FIG. 11 may be combined with various embodiments of the present disclosure.

[0326] Referring to FIG. 11, PSFCH time resources may overlap between SL CA carriers. This can alleviate AGC issues caused by PSFCH transmission and reception. For example, an explanation may be needed regarding the exact meaning of PSFCH time resource overlap between SL CA carriers. For example, in the case of PSFCH time resource overlap, PSFCH resources may be configured and the PSFCH time resource locations may be identical only for resource pools that overlap in the time domain with resource pools where PSFCH resources are configured on different carriers. For example, in the case of PSFCH time resource overlap, if PSFCH resources are configured for (some) resource pools on a specific carrier, PSFCH resources may be configured and the PSFCH time resource locations may be identical for resource pools on all carriers of the SL CA. For example, in case of PSFCH time resource overlap, PSFCH resources may not be configured in a resource pool in which PSFCH resources are configured on different carriers and a resource pool that overlaps in time domain, and the SL symbol start position / number may be set to be the same as the SL slot in the pool in which PSFCH resources are configured, or the SL symbol start position / number parameters may be independently set for slots that overlap with actual PSFCH slots and slots that do not. For example, resource pools in which PSFCH resources are configured and resource pools in which PSFCH resources are not configured between different carriers may not overlap in time domain. For example, even if the PSFCH time resource positions are set to be the same between different carriers, the PSFCH frequency resource positions / PSSCH-to-PSFCH minimum gap, etc. may be set independently.

[0327] For example, in the case of a HARQ feedback ENABLED packet, carrier reselection may be performed only for carriers for which PSFCH resources are configured. In this case, if there is no carrier for which PSFCH resources are configured that satisfies a predefined condition (e.g., CBR), carrier reselection may be performed by changing the characteristic to HARQ feedback DISABLED.

[0328] For example, PSFCH TX or RX capabilities can be defined. For example, PSFCH TX or RX capabilities can be defined independently per carrier or per broadcast, or the capabilities can be defined for a specific carrier and applied equally to the remaining SL CA carriers.

[0329] For example, a power splitting method between SL / UL can be defined for combinations of “multiple SL carriers + one UL carrier” and / or “multiple SL carriers + multiple UL carriers”.

[0330] For example, even if the SCS is the same between carriers, the starting positions and lengths of sidelink symbols may be aligned between carriers.

[0331] For example, in SL CA, SL DRX can be operated as a single pattern for multiple carriers. In this case, a criterion for generating an SL DRX pattern can be defined, for example, when multiple unicast target UE / QoS profile packets are transmitted or received simultaneously.

[0332] For example, RB configuration, SL CSI latency budget, IUC MAC CE, etc. can be configured / operated per PC5 RRC connection unit or per carrier unit.

[0333] For example, (in the case of intraband CA), the half-duplex problem may still exist. Therefore, for example, resources that overlap (in the time domain) with resources selected from other carriers may not be selected as transmission resources. For example, to avoid power sharing, protect against high-priority performance degradation, etc., resources that overlap (in the time domain) with resources selected from other carriers may not be selected as transmission resources.

[0334] For example, when transmitting a PSFCH on a specific carrier, reception of the PSFCH on all other carriers may not be possible. To address this, for example, prioritization between PSFCH TX / RX may be performed, and / or prioritization between PSFCH TX / TX may be performed.

[0335] For example, if the numerology between carriers is different, the emission to a specific carrier may differ due to TX-RX switching gap, PSFCH resources, etc., and AGC problems may occur. For example, the numerology may be limited to be the same between carriers.

[0336] For example, when splitting PSFCH power between carriers, a representative PSFCH priority may be set, and the power may be split between carriers. Alternatively, for example, when splitting PSFCH power between carriers, the power may be split between carriers across carriers. For example, power may be split between carriers across carriers, especially considering that transmit power values ​​should be the same between multiple PSFCH transmissions within a carrier. For example, P_CMAX may be defined considering multiple carriers simultaneously.

[0337] For example, RSRP feedback and / or CSI feedback may be performed across carriers. In this case, for example, carrier indicator information may be included in the RSRP feedback and / or CSI feedback. For example, the CSI feedback latency setting may be configured on a per-carrier basis. For example, the CSI feedback latency setting may be configured commonly across carriers.

[0338] For example, due to different numerologies between carriers, AGC issues may arise, and the half-duplex problem may become more severe. To address this, for example, high-SCS value-based operation that fills slots (boundaries) with low SCS values ​​(or at least fills the first slot with low SCS values) may be supported. For example, the PSFCH period may be defined in units of aggregated slots.

[0339] For example, SL RLF can be operated on a per-PC5 RRC connection basis, and SL RLF can be operated on a per-CA carrier basis (e.g., the carrier with the highest CBR, the carrier with the highest packet priority to be transmitted, or a carrier negotiated between unicast UEs) or all carriers (e.g., DTX counting). For example, primary / secondary carriers can be defined per PC5 RRC connection. For example, the primary carrier can be the same as the above-mentioned carrier selection criteria.

[0340] The various schemes of the present disclosure may be applied differently per unicast session (group) and / or per cast type and / or per transmission priority value and / or per reception priority value and / or per SL transmission with SL HARQ-ACK feedback enabled / disabled and / or per SL HARQ-ACK feedback option and / or per QoS parameter and / or per (remaining) PDB and / or per congestion control level and / or per (transmission and / or reception) resource pool and / or per UE's mobility-related information (e.g., speed, velocity, direction, acceleration, position, height, etc.) and / or per sidelink transmission or reception and / or per HARQ process and / or per beam process and / or per source ID and / or per destination ID and / or per TB. For example, in the embodiments of the present disclosure, the unit of (pre-)configuration may be configured in the form of the above different combinations. For example, in an embodiment of the present disclosure, parameter indication and management via PSCCH and / or PSSCH may be performed in units of the above different combinations. In an embodiment of the present disclosure, spatial setting and / or transmission configuration indicator (TCI) information and / or quasi-co-location (QCL) information, etc. may refer to each other and / or may be interpreted as being replaced with beam-related information, beam direction, spatial domain transmission or reception filter, etc. In an embodiment of the present disclosure, the same spatial setting information for transmission 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 same spatial setting information for reception may mean that two different reception signals are in a QCL 'TYPE D' relationship and / or use the same spatial RX parameters. Various methods of the present disclosure may be applied differently for each SL channel.The various methods of the present disclosure may be applied differently depending on the type of information contained in the SL channel.

[0341] For example, service type (and / or (LCH or service) priority and / or QoS requirements (e.g., delay, reliability, minimum communication range) and / or PQI parameters) (and / or HARQ FEEDBACK ENABLED (and / or DISABLED) LCH / MAC PDU (transmission) and / or CBR measurement value of resource pool and / or SL cast type (e.g., unicast, groupcast, broadcast) and / or SL groupcast HARQ feedback options (e.g., NACK ONLY feedback, ACK / NACK feedback, TX-RX distance based NACK ONLY feedback) and / or SL mode 1 CG type (e.g., SL CG type 1 / 2) and / or SL mode type (e.g., mode 1 / 2) and / or resource pool and / or whether PSFCH resources are configured for the resource pool and / or if periodic resource reservation operation (and / or aperiodic resource reservation operation) is allowed / configured (or not allowed / configured) on the resource pool. and / or partial sensing operation (and / or random resource selection operation (and / or full sensing operation)) is allowed / configured (or not allowed / configured) on the resource pool and / or source (L2) ID (and / or destination (L2) ID) and / or PC5 RRC connection link and / or SL link and / or connection state (with base station) (e.g. RRC CONNECTED state, IDLE state,INACTIVE state) and / or SL HARQ process (ID) and / or whether SL DRX operation (of TX UE or RX UE) is performed and / or whether power saving (TX or RX) UE is performed and / or if (from a specific UE perspective) PSFCH TX and PSFCH RX overlap (and / or multiple PSFCH TXs (exceeding UE CAPABILITY)) (and / or if PSFCH TX (and / or PSFCH RX) is omitted) and / or if RX UE actually (successfully) receives PSCCH (and / or PSSCH) (re)transmission from TX UE and / or if (TX) UE performing packet transmission (and / or transmission resource (re)selection) performs power saving operation (and / or SL DRX operation) and / or if target (RX) UE of transmitted packet performs power saving operation (and / or SL DRX operation) and / or remaining For at least one (or not) of the following elements / parameters: (i) when the PDB value is above (or below) a preset threshold value and / or (ii) when an initial transmission (and / or retransmission) (TB-related) is performed and / or (iii) when an interlace-based (RB) structure is applied and / or (iv) when a (pre-set) channel access type (e.g., Type 1, Type 2A, Type 2B, Type 2C, semi-static channel occupancy) is performed and / or (iv) when transmission / reception of a (pre-set) SL channel / signal (e.g., SL SSB, PSCCH, PSSCH, PSFCH) is performed and / or (iv) when a channel access operation is performed in an unlicensed band, (ii) when a set of RBs (and / or channels and / or carriers) and / or channel occupancy time (COT) and / or TX burst and / or discovery burst,Whether the above rule is applied (and / or the parameter values ​​related to the proposed method / rule of the present disclosure) can be specifically (or differently or independently) set / allowed (and / or the application of the rule can be set / allowed in a limited manner). In addition, a combination of the proposed method (and / or the proposed rule and / or the embodiment) described in the present disclosure can be applied. In addition, in the present disclosure, the term "setting" (or "designation") can be extended to mean a form in which a base station notifies a terminal through a predefined (physical layer or higher layer) channel / signal (e.g., SIB, RRC, MAC CE) (and / or a form provided through pre-setting and / or a form in which a terminal notifies another terminal through a predefined (physical layer or higher layer) channel / signal (e.g., SL MAC CE, PC5 RRC)), etc. In addition, the term "PSFCH" in the present disclosure can be (mutually) extendedly interpreted as "(NR or LTE) PSSCH (and / or (NR or LTE) PSCCH) (and / or (NR or LTE) SL SSB (and / or UL channel / signal))". In addition, the proposed method of the present disclosure can be combined with each other and used in an extended manner (in a new form). In addition, in the present disclosure, the term "ACTIVE TIME" (and / or "ON DURATION") can be (mutually) extendedly interpreted as "ON DURATION" (and / or "ACTIVE TIME").

[0342] FIG. 12 illustrates a method for a first device to perform wireless communication according to an embodiment of the present disclosure. The embodiment of FIG. 12 may be combined with various embodiments of the present disclosure.

[0343] Referring to FIG. 12, in step S1210, a first device may establish a PC5 RRC (radio resource control) connection with a second device. In step S1220, the first device may select multiple carriers. In step S1230, the first device may release a carrier based on whether the number of continuous discontinuous transmissions (DTXs) ​​for a carrier among the multiple carriers reaches a threshold. In step S1240, the first device may detect a sidelink radio link failure based on whether all of the multiple carriers are released.

[0344] For example, based on the detection of the sidelink radio link failure, the PC5 RRC connection may be released.

[0345] For example, the PC5 RRC connection may be maintained based on some of the plurality of carriers being released.

[0346] For example, based on the data to be transmitted by the first device being set to enable hybrid automatic repeat request (HARQ) feedback, the plurality of carriers may be selected from among carriers that (i) have physical sidelink feedback channel (PSFCH) resources set, and (ii) have a channel busy ratio (CBR) measurement value smaller than a CBR threshold. For example, the CBR threshold used to select the plurality of carriers may be related to a priority of the data.

[0347] For example, the plurality of carriers may be carriers associated with the PC5 RRC connection.

[0348] For example, prioritization for PSFCH transmission can be performed across the multiple carriers.

[0349] For example, PSFCH resources on the plurality of carriers can be aligned in the time domain.

[0350] For example, the frequency domain of the PSFCH resource or the minimum time gap between the PSFCH and the PSSCH (physical sidelink shared channel) can be independently set for the plurality of carriers.

[0351] For example, the position of the sidelink start symbol, the number of sidelink symbols, the cyclic prefix, and the subcarrier spacing may be set identically for the plurality of carriers.

[0352] Additionally, for example, the first device may report information related to the carrier to the base station based on the number of consecutive DTXs for the carrier among the plurality of carriers reaching the threshold.

[0353] Additionally, for example, the first device may transmit information to the second device about whether packet duplication is supported.

[0354] Additionally, for example, the first device may transmit a first PC5 RRC message to the second device for carrier addition or modification. Additionally, for example, the first device may receive a second PC5 RRC message from the second device for completion of the carrier addition or modification.

[0355] 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 establish a PC5 RRC (radio resource control) connection with the second device. Then, the processor (102) of the first device (100) can select multiple carriers. Then, the processor (102) of the first device (100) can release a carrier based on whether the number of continuous discontinuous transmissions (DTXs) ​​for a carrier among the multiple carriers reaches a threshold. Then, the processor (102) of the first device (100) can detect a sidelink radio link failure based on whether all of the multiple carriers are released.

[0356] 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: establish a PC5 RRC (radio resource control) connection with a second device; select a plurality of carriers; release a carrier based on a number of continuous discontinuous transmissions (DTXs) ​​for a carrier among the plurality of carriers reaching a threshold; and detect a sidelink radio link failure based on all of the plurality of carriers being released.

[0357] 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: establish a PC5 RRC (radio resource control) connection with a second device; select a plurality of carriers; release a carrier based on a number of continuous discontinuous transmissions (DTXs) ​​for a carrier among the plurality of carriers reaching a threshold; and detect a sidelink radio link failure based on all of the plurality of carriers being released.

[0358] 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: establish a PC5 RRC (radio resource control) connection with a second device; select a plurality of carriers; release a carrier based on a number of continuous discontinuous transmissions (DTXs) ​​for a carrier among the plurality of carriers reaching a threshold; and detect a sidelink radio link failure based on all of the plurality of carriers being released.

[0359] FIG. 13 illustrates a method for a second device to perform wireless communication according to an embodiment of the present disclosure. The embodiment of FIG. 13 may be combined with various embodiments of the present disclosure.

[0360] Referring to FIG. 13, in step S1310, the second device may establish a PC5 RRC (radio resource control) connection with the first device. For example, based on the number of continuous discontinuous transmissions (DTXs) ​​for a carrier among multiple carriers reaching a threshold, the carrier may be released by the first device. For example, based on all of the multiple carriers being released, a sidelink radio link failure may be detected by the first device.

[0361] 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 establish a PC5 RRC (radio resource control) connection with the first device. For example, based on the number of continuous discontinuous transmissions (DTXs) ​​for a carrier among a plurality of carriers reaching a threshold, the carrier can be released by the first device. For example, based on the release of all of the plurality of carriers, a sidelink radio link failure can be detected by the first device.

[0362] 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: establish a PC5 radio resource control (RRC) connection with a first device. For example, based on a number of continuous discontinuous transmissions (DTXs) ​​for a carrier among a plurality of carriers reaching a threshold, the carrier may be released by the first device. For example, based on all of the plurality of carriers being released, a sidelink radio link failure may be detected by the first device.

[0363] 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: establish a PC5 radio resource control (RRC) connection with the first device. For example, based on a number of continuous discontinuous transmissions (DTXs) ​​for a carrier among a plurality of carriers reaching a threshold, the carrier may be released by the first device. For example, based on all of the plurality of carriers being released, a sidelink radio link failure may be detected by the first device.

[0364] 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: establish a PC5 RRC (radio resource control) connection with a first device. For example, a carrier may be released by the first device based on a number of continuous discontinuous transmissions (DTXs) ​​for a carrier among a plurality of carriers reaching a threshold. For example, a sidelink radio link failure may be detected by the first device based on all of the plurality of carriers being released.

[0365] According to various embodiments of the present disclosure, if a carrier failure occurs for all carriers that include a resource pool in which PSFCH resources are configured and satisfy a preset CBR condition (e.g., a carrier having a CBR value lower than a preset CBR threshold level linked to a priority of a transmission packet), the terminal may declare a radio link failure for a unicast session. Here, for example, a carrier failure for a specific carrier may mean that a preset threshold number of consecutive DTXs have occurred on the corresponding carrier. In addition, by aligning PSFCH resources between carriers in the time domain and / or aligning sidelink symbol positions between carriers, an AGC problem may be prevented from occurring in communications based on carrier aggregation.

[0366] The various embodiments of the present disclosure may be combined with each other.

[0367] Below, a description is given of devices to which various embodiments of the present disclosure can be applied.

[0368] 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.

[0369] 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.

[0370] FIG. 14 illustrates a communication system (1) according to one embodiment of the present disclosure. The embodiment of FIG. 14 can be combined with various embodiments of the present disclosure.

[0371] Referring to FIG. 14, 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). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices, and can be implemented in the form of HMD (Head-Mounted Device), HUD (Head-Up Display) installed in a vehicle, television, smartphone, computer, wearable device, home appliance, digital signage, vehicle, robot, etc. Mobile devices can include smartphone, smart pad, wearable device (e.g., smart watch, smart glass), computer (e.g., laptop, etc.), etc. Home appliances can include TV, refrigerator, washing machine, etc. IoT devices can include sensors, smart meters, etc. For example, base stations and networks can also be implemented as wireless devices, and a specific wireless device (200a) can act as a base station / network node to other wireless devices.

[0372] 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.

[0373] 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).

[0374] 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.

[0375] FIG. 15 illustrates a wireless device according to an embodiment of the present disclosure. The embodiment of FIG. 15 may be combined with various embodiments of the present disclosure.

[0376] Referring to FIG. 15, 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. 14.

[0377] 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.

[0378] 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.

[0379] 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.

[0380] 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 driven 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.

[0381] 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.

[0382] 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.

[0383] FIG. 16 illustrates a signal processing circuit for a transmission signal according to an embodiment of the present disclosure. The embodiment of FIG. 16 can be combined with various embodiments of the present disclosure.

[0384] Referring to FIG. 16, 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. 16 may be performed in the processor (102, 202) and / or the transceiver (106, 206) of FIG. 15. The hardware elements of FIG. 16 may be implemented in the processor (102, 202) and / or the transceiver (106, 206) of FIG. 15. For example, blocks 1010 to 1060 may be implemented in the processor (102, 202) of FIG. 15. Additionally, blocks 1010 to 1050 may be implemented in the processor (102, 202) of FIG. 15, and block 1060 may be implemented in the transceiver (106, 206) of FIG. 15.

[0385] The codeword can be converted into a wireless signal through the signal processing circuit (1000) of FIG. 16. 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).

[0386] 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.

[0387] 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.

[0388] 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. 16. For example, a wireless device (e.g., 100, 200 of FIG. 15) 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.

[0389] Figure 17 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 14). The embodiment of Figure 17 may be combined with various embodiments of the present disclosure.

[0390] Referring to FIG. 17, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 15 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 additional elements (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. 15. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 15. 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).

[0391] 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. 14, 100a), a vehicle (Fig. 14, 100b-1, 100b-2), an XR device (Fig. 14, 100c), a portable device (Fig. 14, 100d), a home appliance (Fig. 14, 100e), an IoT device (Fig. 14, 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. 14, 400), a base station (Fig. 14, 200), a network node, etc. Wireless devices may be mobile or stationary depending on the use / service.

[0392] In FIG. 17, 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.

[0393] Below, the implementation example of Fig. 17 is described in more detail with reference to the drawings.

[0394] FIG. 18 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. 18 may be combined with various embodiments of the present disclosure.

[0395] Referring to FIG. 18, 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. 17, respectively.

[0396] 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.

[0397] 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).

[0398] FIG. 19 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 FIG. 19 may be combined with various embodiments of the present disclosure.

[0399] Referring to FIG. 19, 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. 17, respectively.

[0400] 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.

[0401] 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.

[0402] The claims set forth in this specification may be combined in various ways. For example, the technical features of the method claims of this specification may be combined and implemented as a device, and the technical features of the device claims of this specification may be combined and implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a device, and the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a method.

Claims

1. In a method for performing wireless communication by a first device, Step of establishing a PC5 RRC (radio resource control) connection with the second device; Step of selecting multiple carriers; A step of releasing a carrier based on the number of continuous DTXs (discontinuous transmissions) for a carrier among the plurality of carriers reaching a threshold; and A method comprising: detecting a sidelink radio link failure based on all of the above multiple carriers being released; 2. In paragraph 1, A method wherein the PC5 RRC connection is released based on the detection of the above sidelink wireless link failure.

3. In paragraph 1, A method wherein the PC5 RRC connection is maintained based on some of the plurality of carriers being released.

4. In paragraph 1, A method wherein the plurality of carriers are selected from among carriers that (i) have PSFCH (physical sidelink feedback channel) resources set and (ii) have a CBR measurement value less than a CBR (channel busy ratio) threshold, based on the data to be transmitted by the first device being set to HARQ (hybrid automatic repeat request) feedback enable.

5. In paragraph 4, A method wherein the CBR threshold used to select the plurality of carriers is related to the priority of the data.

6. In paragraph 1, A method wherein the plurality of carriers are carriers associated with the PC5 RRC connection.

7. In paragraph 1, A method wherein prioritization for PSFCH transmission is performed across the plurality of carriers.

8. In paragraph 1, A method wherein PSFCH resources on the plurality of carriers are aligned in the time domain.

9. In paragraph 1, A method in which the frequency domain of PSFCH resources or the minimum time gap between PSFCH and PSSCH (physical sidelink shared channel) is independently set for the plurality of carriers.

10. In paragraph 1, A method in which the position of the sidelink start symbol, the number of sidelink symbols, the cyclic prefix, and the subcarrier spacing are set identically for the plurality of carriers.

11. In paragraph 1, A method further comprising: a step of reporting information related to the carrier to a base station based on the number of consecutive DTXs for the carrier among the plurality of carriers reaching the threshold; 12. In paragraph 1, A method further comprising the step of transmitting information on whether packet duplication is supported to the second device.

13. In paragraph 1, A step of transmitting a first PC5 RRC message for adding or modifying a carrier to the second device; and A method further comprising: receiving a second PC5 RRC message from the second device for completion of the carrier addition or modification.

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: Establish a PC5 RRC (radio resource control) connection with the second device; Allows you to choose multiple carriers; Release the carrier based on the number of continuous DTXs (discontinuous transmissions) for the carrier among the plurality of carriers reaching a threshold; and A first device that detects a sidelink radio link failure based on all of the above multiple carriers being released.

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: Establish a PC5 RRC (radio resource control) connection with the second device; Allows you to choose multiple carriers; Release the carrier based on the number of continuous DTXs (discontinuous transmissions) for the carrier among the plurality of carriers reaching a threshold; and A processing device that detects a sidelink radio link failure based on all of the above multiple carriers being released.

16. A non-transitory computer-readable storage medium that records commands, The above commands, when executed, cause the first device to: Establish a PC5 RRC (radio resource control) connection with the second device; Allows you to choose multiple carriers; Release the carrier based on the number of continuous DTXs (discontinuous transmissions) for the carrier among the plurality of carriers reaching a threshold; and A non-transitory computer-readable storage medium for detecting a sidelink radio link failure based on all of the above multiple carriers being released.

17. In a method for performing wireless communication by a second device, A step of establishing a PC5 RRC (radio resource control) connection with the first device; Based on the number of continuous discontinuous transmissions (DTXs) ​​for a carrier among multiple carriers reaching a threshold, the carrier is released by the first device, and A method wherein a sidelink radio link failure is detected by the first device based on all of the above multiple carriers being released.

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: Establish a PC5 RRC (radio resource control) connection with the first device, Based on the number of continuous discontinuous transmissions (DTXs) ​​for a carrier among multiple carriers reaching a threshold, the carrier is released by the first device, and A second device, wherein a sidelink radio link failure is detected by the first device based on all of the above multiple carriers being released.

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: Establish a PC5 RRC (radio resource control) connection with the first device, Based on the number of continuous discontinuous transmissions (DTXs) ​​for a carrier among multiple carriers reaching a threshold, the carrier is released by the first device, and A processing device, wherein a sidelink radio link failure is detected by the first device based on all of the above multiple carriers being released.

20. A non-transitory computer-readable storage medium that records commands, The above commands, when executed, cause the second device to: Establish a PC5 RRC (radio resource control) connection with the first device, Based on the number of continuous discontinuous transmissions (DTXs) ​​for a carrier among multiple carriers reaching a threshold, the carrier is released by the first device, and A non-transitory computer-readable storage medium, wherein a sidelink radio link failure is detected by the first device based on all of the above multiple carriers being released.

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