Operation method of a relay UE related to link quality in a wireless communication system

Abstract

One embodiment is a method for operating a relay User Equipment (UE) in a wireless communication system, comprising: a step in which the relay UE measures the link quality between a source UE and the relay UE; and a step in which the relay UE receives information from a remote UE regarding the link quality between the relay UE and the remote UE, wherein if the relay UE does not know the Quality of Service (QoS) required for a message, the method performs resource reselection based on the difference between the link quality between the source UE and the relay UE and the link quality between the relay UE and the remote UE being greater than a preset value.

Description

Technology Field

[0001] The following description relates to a wireless communication system, and more specifically, to a method and apparatus related to operations, resource reselection, etc., concerning the link quality of a sidelink relay UE. Background Technology

[0002] Wireless communication systems are being widely deployed to provide various types of communication services, such as voice and data. Generally, a wireless communication system is a multiple access system capable of supporting communication with multiple users by sharing available system resources (bandwidth, transmission power, etc.). Examples of multiple access systems include CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), SC-FDMA (single carrier frequency division multiple access), and MC-FDMA (multi carrier frequency division multiple access) systems.

[0003] In wireless communication systems, various Radio Access Technologies (RATs) such as LTE, LTE-A, and WiFi are used, and 5G is included in this. The three major requirement areas of 5G include (1) the Enhanced Mobile Broadband (eMBB) area, (2) the Massive Machine Type Communication (mMTC) area, and (3) the Ultra-reliable and Low Latency Communications (URLLC) area. Some use cases may require multiple areas for optimization, while others may focus on only a single Key Performance Indicator (KPI). 5G supports these various use cases in a flexible and reliable manner.

[0004] eMBB goes far beyond basic mobile internet access, covering media and entertainment applications in rich interactive tasks, the cloud, or augmented reality. Data is one of the core drivers of 5G, and dedicated voice services may not be seen for the first time in the 5G era. In 5G, voice is expected to be processed simply as an application using the data connection provided by the communication system. The main causes for the increased traffic volume are the increase in content size and the growing number of applications requiring high data transfer rates. Streaming services (audio and video), interactive video, and mobile internet connectivity will become more widely used as more devices connect to the internet. Many of these applications require always-on connectivity to push real-time information and notifications to users. Cloud storage and applications are growing rapidly on mobile communication platforms, and this can be applied to both work and entertainment. Furthermore, cloud storage is a specific use case driving the growth of uplink data transfer rates. 5G is also used for remote work in the cloud, requiring much lower end-to-end latency to maintain an excellent user experience when haptic interfaces are used. Entertainment, for example, cloud gaming and video streaming, is another key factor increasing the demand for mobile broadband capabilities. Entertainment is essential on smartphones and tablets anywhere, including in highly mobile environments such as trains, cars, and airplanes. Other use cases include augmented reality for entertainment and information retrieval. Here, augmented reality requires very low latency and instantaneous data volumes.

[0005] Furthermore, one of the most anticipated use cases for 5G concerns mMTC, the ability to seamlessly connect embedded sensors across all fields. The number of potential IoT devices is projected to reach 20.4 billion by 2020. Industrial IoT is one of the areas where 5G plays a key role in enabling smart cities, asset tracking, smart utilities, agriculture, and security infrastructure.

[0006] URLLC includes new services that will transform industries through ultra-reliable / available low-latency links, such as remote control of critical infrastructure and self-driving vehicles. Levels of reliability and latency are essential for smart grid control, industrial automation, robotics, and drone control and coordination.

[0007] Next, we will examine several usage examples in more detail.

[0008] 5G can complement FTTH (fiber-to-the-home) and cable-based broadband (or DOCSIS) as a means of providing streams rated at hundreds of megabits per second to gigabits per second. These high speeds are required for virtual and augmented reality, as well as for delivering TV at resolutions of 4K and above (6K, 8K, and higher). VR (Virtual Reality) and AR ( Augmented Reality) applications include near-immersive sports matches. Certain applications may require special network configurations. For example, in the case of VR games, game companies may need to integrate core servers with the network operator's edge network servers to minimize latency.

[0009] The automotive sector is expected to become a significant new driving force for 5G, with numerous use cases for mobile communications within vehicles. For instance, passenger entertainment requires high-capacity and high-mobility mobile broadband. This is because future users expect high-quality connectivity regardless of their location or speed. Another application in the automotive sector is the augmented reality dashboard. This displays information overlaid onto what the driver is seeing through the windshield, allowing them to identify objects in the dark and providing the driver with information about the objects' distances and movements. In the future, wireless modules will enable communication between vehicles, information exchange between vehicles and supporting infrastructure, and information exchange between vehicles and other connected devices (e.g., devices accompanying pedestrians). Safety systems will allow drivers to drive more safely by guiding them to alternative courses of action, thereby reducing the risk of accidents. The next step will be remotely controlled or self-driven vehicles. This requires highly reliable and very fast communication between different self-driven vehicles and between vehicles and infrastructure. In the future, self-driving vehicles will perform all driving activities, allowing drivers to focus solely on traffic anomalies that the vehicle itself cannot identify. The technical requirements for self-driving vehicles demand ultra-low latency and ultra-high reliability to increase traffic safety to a level unattainable by humans.

[0010] Smart cities and smart homes, referred to as a smart society, will be embedded with high-density wireless sensor networks. Distributed networks of intelligent sensors will identify conditions for maintaining the cost-effective and energy-efficient maintenance of the city or home. A similar setup can be implemented for each household. Temperature sensors, window and heating controllers, burglar alarms, and home appliances are all wirelessly connected. Many of these sensors typically feature low data transfer rates, low power consumption, and low cost. However, for example, real-time HD video may be required for certain types of devices for surveillance.

[0011] The consumption and distribution of energy, including heat or gas, are becoming highly decentralized, requiring automated control of distributed sensor networks. Smart grids interconnect these sensors using digital information and communication technologies to collect information and act accordingly. Since this information may include the behavior of suppliers and consumers, smart grids can improve efficiency, reliability, economic viability, production sustainability, and the automated distribution of fuels such as electricity. A smart grid can also be viewed as another sensor network with low latency.

[0012] The health sector possesses numerous applications that can benefit from mobile communications. Communication systems can support telemedicine, providing clinical care from remote locations. This helps reduce distance barriers and improves access to medical services that are not consistently available in remote rural areas. It is also used to save lives during critical medical care and emergencies. Mobile communication-based wireless sensor networks can provide remote monitoring and sensors for parameters such as heart rate and blood pressure.

[0013] Wireless and mobile communications are becoming increasingly important in industrial applications. Wiring is expensive to install and maintain. Therefore, the potential to replace cables with reconfigurable wireless links presents an attractive opportunity in many industries. However, achieving this requires wireless connections to operate with latency, reliability, and capacity comparable to cables, while also simplifying their management. Low latency and a very low probability of error are new requirements that 5G needs to meet.

[0014] Logistics and freight tracking are important use cases for mobile communications that use location-based information systems to enable the tracking of inventory and packages anywhere. Use cases for logistics and freight tracking typically require low data rates but necessitate wide coverage and reliable location information.

[0015] A wireless communication system is a multiple access system that supports communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power, etc.). Examples of multiple access systems include CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), SC-FDMA (single carrier frequency division multiple access), and MC-FDMA (multi carrier frequency division multiple access) systems.

[0016] Sidelink (SL) refers to a communication method in which User Equipment (UE) establishes a direct link to directly exchange voice or data between terminals without passing through a Base Station (BS). SL is being considered as a solution to address the burden on base stations caused by rapidly increasing data traffic.

[0017] V2X (vehicle-to-everything) refers to a communication technology that exchanges information with other vehicles, pedestrians, and infrastructure-equipped objects through wired or wireless communication. V2X can be classified 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 PC5 interfaces and / or Uu interfaces.

[0018] Meanwhile, as more communication devices require larger communication capacities, the need for improved mobile broadband communication compared to existing Radio Access Technology (RAT) is emerging. Accordingly, communication systems considering services or terminals sensitive to reliability and latency are being discussed; next-generation radio access technology that incorporates improved mobile broadband communication, Massive Machine Type Communication (MTC), and Ultra-Reliable and Low Latency Communication (URLC) can be referred to as new radio access technology (new RAT) or new radio (NR). Vehicle-to-everything (V2X) communication can also be supported in NR.

[0019] Figure 1 is a diagram illustrating a comparison between V2X communication based on RAT prior to NR and V2X communication based on NR.

[0020] Regarding V2X communication, prior to NR, RATs mainly discussed methods for providing safety services based on V2X messages such as BSM (Basic Safety Message), CAM (Cooperative Awareness Message), and DENM (Decentralized Environmental Notification Message). V2X messages can include location information, dynamic information, attribute information, etc. For example, a terminal can transmit a CAM of the periodic message type and / or a DENM of the event-triggered message type to another terminal.

[0021] For example, the CAM may include basic vehicle information such as dynamic state information of the vehicle, such as direction and speed, static data of the vehicle, such as dimensions, external lighting conditions, and route history. For example, a terminal may broadcast the CAM, and the latency of the CAM may be less than 100ms. For example, in the event of an unexpected situation such as a vehicle breakdown or accident, the terminal may generate a DENM and transmit it to other terminals. For example, all vehicles within the transmission range of the terminal may receive the CAM and / or DENM. In this case, the DENM may have a higher priority than the CAM.

[0022] Since then, various V2X scenarios regarding V2X communication have been presented in NR. For example, various V2X scenarios may include vehicle platooning, advanced driving, extended sensors, remote driving, etc.

[0023] For example, based on vehicle platooning, vehicles can dynamically form groups and move together. For example, to perform platoon operations based on vehicle platooning, vehicles belonging to said group can receive periodic data from the lead vehicle. For example, vehicles belonging to said group can use the periodic data to reduce or increase the distance between vehicles.

[0024] For example, based on enhanced driving, vehicles can be semi-automated or fully automated. For example, each vehicle can adjust trajectories or maneuvers based on data acquired from local sensors of nearby vehicles and / or nearby logical entities. Additionally, for example, each vehicle can mutually share driving intentions with nearby vehicles.

[0025] For example, based on extended sensors, raw data or processed data or live video data acquired through local sensors can be exchanged between vehicles, logical entities, pedestrian terminals and / or V2X application servers. Thus, for example, a vehicle can perceive an environment that is enhanced compared to the environment it can detect using its own sensors.

[0026] For example, based on remote driving, a remote driver or V2X application can operate or control a remote vehicle for a person unable to drive or for a remote vehicle located in a dangerous environment. For example, in cases where the route is predictable, such as in public transportation, cloud computing-based driving can be used for the operation or control of the remote vehicle. Additionally, access to a cloud-based back-end service platform, for example, can be considered for remote driving.

[0027] Meanwhile, methods to specify service requirements for various V2X scenarios, such as vehicle platooning, enhanced driving, extended sensors, and remote driving, are being discussed in NR-based V2X communication. The problem to be solved

[0028] The embodiment(s) have as technical tasks a method related to the determination of link quality between the relay UE and the remote UE, resource reselection, etc. means of solving the problem

[0029] One embodiment is a method for operating a relay User Equipment (UE) in a wireless communication system, comprising: a step in which the relay UE measures the link quality between a source UE and the relay UE; and a step in which the relay UE receives information from a remote UE regarding the link quality between the relay UE and the remote UE, wherein if the relay UE does not know the Quality of Service (QoS) required for a message, the method performs resource reselection based on the difference between the link quality between the source UE and the relay UE and the link quality between the relay UE and the remote UE being greater than a preset value.

[0030] One embodiment is a relay User Equipment (UE) in a wireless communication system, comprising: at least one processor; and at least one computer memory that can be operably connected to the at least one processor and stores instructions that, when executed, cause the at least one processor to perform operations, wherein the operations include: measuring the link quality between a source UE and the relay UE; and receiving information from a remote UE regarding the link quality between the relay UE and the remote UE, wherein if the relay UE does not know the Quality of Service (QoS) required for the message, the relay UE performs resource reselection based on the difference between the link quality between the source UE and the relay UE and the link quality between the relay UE and the remote UE being greater than a preset value.

[0031] One embodiment is a processor for performing operations for a relay User Equipment (UE) in a wireless communication system, wherein the operations include: measuring the link quality between a source UE and the relay UE; and receiving information from a remote UE regarding the link quality between the relay UE and the remote UE, wherein if the relay UE does not know the Quality of Service (QoS) required for a message, the processor performs resource reselection based on the difference between the link quality between the source UE and the relay UE and the link quality between the relay UE and the remote UE being greater than a preset value.

[0032] One embodiment is a nonvolatile computer-readable storage medium that stores at least one computer program including instructions that, when executed by at least one processor, cause at least one processor to perform operations for a UE, wherein the operations include: measuring the link quality between a source UE and the relay UE; and receiving information from a remote UE regarding the link quality between the relay UE and the remote UE, wherein if the relay UE does not know the Quality of Service (QoS) required for a message, the storage medium performs resource reselection based on the difference between the link quality between the source UE and the relay UE and the link quality between the relay UE and the remote UE being greater than a preset value.

[0033] The above-mentioned re-selected resource may be a resource used between the relay UE and the remote UE.

[0034] The above resource reselection can be performed when the congestion level is below a certain value.

[0035] If the relay UE knows the QoS required for the message, the relay UE may perform resource reselection based on the fact that the link quality between the relay UE and the remote UE does not satisfy the QoS.

[0036] Based on the information regarding the link quality between the relay UE and the remote UE reported to the source UE, the relay UE can receive resource reselection triggering from the source UE. Effects of the invention

[0037] According to one embodiment, link quality management can be performed efficiently by performing resource reselection after comparing link quality. Brief explanation of the drawing

[0038] The drawings attached to this specification are intended to provide an understanding of the embodiment(s), to illustrate various embodiments, and to explain the principles together with the description in the specification. Figure 1 is a diagram illustrating a comparison between V2X communication based on RAT prior to NR and V2X communication based on NR. FIG. 2 shows the structure of an LTE system according to one embodiment of the present disclosure. FIG. 3 shows a radio protocol architecture for a user plane and a control plane according to one embodiment of the present disclosure. FIG. 4 shows the structure of an NR system according to one embodiment of the present disclosure. FIG. 5 shows a functional split between NG-RAN and 5GC according to one embodiment of the present disclosure. FIG. 6 shows the structure of a wireless frame of NR to which the embodiment(s) can be applied. FIG. 7 shows a slot structure of an NR frame according to one embodiment of the present disclosure. FIG. 8 shows a radio protocol architecture for SL communication according to one embodiment of the present disclosure. FIG. 9 shows a radio protocol architecture for SL communication according to one embodiment of the present disclosure. FIG. 10 illustrates a procedure in which a terminal performs V2X or SL communication according to a transmission mode, in accordance with one embodiment of the present disclosure. FIGS. 11 and 12 are drawings for explaining the embodiment(s). FIGS. 13 to 19 are drawings illustrating various devices to which the embodiment(s) can be applied. Specific details for implementing the invention

[0039] In various embodiments of the present disclosure, “ / ” and “,” should be interpreted as indicating “and / or.” For example, “A / B” may mean “A and / or B.” Furthermore, “A, B” may mean “A and / or B.” Furthermore, “A / B / C” may mean “at least one of A, B and / or C.” Furthermore, “A, B, C” may mean “at least one of A, B and / or C.”

[0040] In various embodiments of the present disclosure, “or” should be interpreted as indicating “and / or.” For example, “A or B” may include “only A,” “only B,” and / or “both A and B.” In other words, “or” should be interpreted as indicating “additionally or alternatively.”

[0041] 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 using wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented using wireless technologies such as GSM (global system for mobile communications), GPRS (general packet radio service), and EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented using 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 and provides 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 part of E-UMTS (evolved UMTS) which 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.

[0042] 5G NR is a successor technology to LTE-A and is a new clean-slate type mobile communication system with characteristics such as high performance, low latency, and high availability. 5G NR can utilize all available spectrum resources, ranging from low frequency bands below 1 GHz to mid-frequency bands from 1 GHz to 10 GHz, and high frequency (millimeter wave) bands above 24 GHz.

[0043] For clarity of explanation, the description focuses on LTE-A or 5G NR, but the technical concept according to one embodiment of the present disclosure is not limited thereto.

[0044] FIG. 2 shows the structure of an LTE system according to one embodiment of the present disclosure. This may be called an E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) or an LTE (Long Term Evolution) / LTE-A system.

[0045] Referring to FIG. 2, the E-UTRAN includes a base station (20) that provides a control plane and a user plane to a terminal (10). The terminal (10) may be fixed or mobile and may be referred to by other terms such as MS (Mobile Station), UT (User Terminal), SS (Subscriber Station), MT (Mobile Terminal), or Wireless Device. The base station (20) refers to a fixed station that communicates with the terminal (10) and may be referred to by other terms such as eNB (evolved-NodeB), BTS (Base Transceiver System), or Access Point.

[0046] Base stations (20) can be connected to each other through an X2 interface. The base station (20) is connected to the EPC (Evolved Packet Core, 30) through the S1 interface, more specifically to the MME (Mobility Management Entity) through the S1-MME and to the S-GW (Serving Gateway) through the S1-U.

[0047] The EPC (30) consists of an MME, an S-GW, and a P-GW (Packet Data Network-Gateway). The MME holds information regarding the terminal's connection information or capabilities, and this information is primarily used for managing the terminal's mobility. The S-GW is a gateway with an E-UTRAN as its endpoint, and the P-GW is a gateway with a PDN (Packet Data Network) as its endpoint.

[0048] The layers of the Radio Interface Protocol between a terminal and a network can be classified into L1 (Layer 1), L2 (Layer 2), and L3 (Layer 3) based on the lower three layers of the Open System Interconnection (OSI) model, which is widely known in communication systems. Among these, the Physical Layer, belonging to Layer 1, provides Information Transfer Services using a physical channel, while the Radio Resource Control (RRC) layer, located at Layer 3, performs the role of controlling radio resources between the terminal and the network. To this end, the RRC layer exchanges RRC messages between the terminal and the base station.

[0049] FIG. 3(a) shows a radio protocol architecture for a user plane according to one embodiment of the present disclosure.

[0050] FIG. 3(b) shows a wireless protocol structure for a control plane according to one embodiment of the present disclosure. The user plane is a protocol stack for transmitting user data, and the control plane is a protocol stack for transmitting control signals.

[0051] Referring to Figure 3(a) and A3, the physical layer provides information transmission services to the upper layer using a physical channel. The physical layer is connected to the upper layer, the MAC (Medium Access Control) layer, through a transport channel. Data travels between the MAC layer and the physical layer through the transport channel. Transport channels are classified according to how and with what characteristics data is transmitted through a wireless interface.

[0052] Data travels between different physical layers, specifically between the physical layers of the transmitter and the receiver, through a physical channel. This physical channel can be modulated using Orthogonal Frequency Division Multiplexing (OFDM) and utilizes time and frequency as wireless resources.

[0053] The MAC layer provides services to the upper layer, the RLC (radio link control) layer, through logical channels. The MAC layer provides mapping functions from multiple logical channels to multiple transmission channels. Additionally, the MAC layer provides logical channel multiplexing functions through mapping from multiple logical channels to a single transmission channel. The MAC sublayer provides data transmission services over logical channels.

[0054] The RLC layer performs the concatenation, segmentation, and reassembly of RLC Serving Data Units (SDUs). To guarantee the various Quality of Service (QoS) required by the Radio Bearer (RB), 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 Requests (ARQ).

[0055] The RRC (Radio Resource Control) layer is defined only in the control plane. The RRC layer is responsible for controlling logical channels, transmission channels, and physical channels in relation to the configuration, reconfiguration, and release of wireless bearers. RB refers to the logical path provided by the first layer (physical layer or PHY layer) and the second layer (MAC layer, RLC layer, PDCP (Packet Data Convergence Protocol) layer) for data transmission between a terminal and a network.

[0056] The functions of the PDCP layer in the user plane include the delivery of user data, header compression, and ciphering. The functions of the PDCP layer in the control plane include the delivery of control plane data and encryption / integrity protection.

[0057] The establishment of an RB refers to the process of defining the characteristics of the wireless protocol layer and channel to provide specific services, and setting their respective specific parameters and operating methods. RBs can be further divided into two types: SRBs (Signaling Radio Bearers) and DRBs (Data Radio Bearers). SRBs are used as a channel for transmitting RRC messages in the control plane, while DRBs are used as a channel for transmitting user data in the user plane.

[0058] When an RRC connection is established between the RRC layer of the terminal and the RRC layer of the E-UTRAN, 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 maintains a connection with the core network while releasing the connection with the base station.

[0059] Downlink transmission channels for transmitting data from a network to a terminal include a Broadcast Channel (BCH) for transmitting system information and a Shared Channel (SCH) for transmitting user traffic or control messages. Traffic or control messages for downlink multicast or broadcast services may be transmitted via the Shared Channel (SCH) or via a separate Multicast Channel (MCH). Meanwhile, uplink transmission channels for transmitting data from a terminal to a network include a Random Access Channel (RACH) for transmitting initial control messages and a Shared Channel (SCH) for transmitting user traffic or control messages.

[0060] Logical channels that are above the transmission channel and mapped to the transmission channel include BCCH (Broadcast Control Channel), PCCH (Paging Control Channel), CCCH (Common Control Channel), MCCH (Multicast Control Channel), and MTCH (Multicast Traffic Channel).

[0061] A physical channel consists of multiple OFDM symbols in the time domain and multiple subcarriers in the frequency domain. A single subframe consists of multiple OFDM symbols in the time domain. A resource block is a resource allocation unit composed of multiple OFDM symbols and multiple subcarriers. Additionally, each subframe may utilize specific subcarriers of specific OFDM symbols (e.g., the first OFDM symbol) within that subframe for the Physical Downlink Control Channel (PDCCH), i.e., the L1 / L2 control channel. The Transmission Time Interval (TTI) is the unit time for subframe transmission.

[0062] FIG. 4 shows the structure of an NR system according to one embodiment of the present disclosure.

[0063] Referring to FIG. 4, the Next Generation Radio Access Network (NG-RAN) may include a gNB (next generation-Node B) and / or an eNB that provides user plane and control plane protocol termination to terminals. FIG. 4 illustrates a case where only a gNB is included. The gNB and eNB are connected to each other via an Xn interface. The gNB and eNB are connected to the 5th Generation Core Network (5G Core Network: 5GC) via an NG interface. More specifically, they are connected to the access and mobility management function (AMF) via an NG-C interface and to the user plane function (UPF) via an NG-U interface.

[0064] FIG. 5 shows a functional split between NG-RAN and 5GC according to one embodiment of the present disclosure.

[0065] Referring to FIG. 5, the gNB can provide functions such as Inter Cell Radio Resource Management (Inter Cell RRM), Radio Bearer Management (RB control), Connection Mobility Control, Radio Admission Control, Measurement Configuration & Provision, and Dynamic Resource Allocation. The AMF can provide functions such as Non Access Stratum (NAS) security and idle state mobility processing. The UPF can provide functions such as Mobility Anchoring and Protocol Data Unit (PDU) processing. The Session Management Function (SMF) can provide functions such as terminal IP (Internet Protocol) address allocation and PDU session control.

[0066] Figure 6 shows the structure of a wireless frame of NR to which the present invention can be applied.

[0067] Referring to FIG. 6, radio frames can be used for uplink and downlink transmission in NR. The radio frame has a length of 10 ms and can be defined as two 5 ms half-frames (HF). A half-frame may contain five 1 ms subframes (SF). A subframe may be divided into one or more slots, and the number of slots within a subframe may be determined by the subcarrier spacing (SCS). Each slot may contain 12 or 14 OFDM(A) symbols according to the cyclic prefix (CP).

[0068] When normal CP is used, each slot may contain 14 symbols. When extended CP is used, each slot may contain 12 symbols. Here, the symbols may include OFDM symbols (or CP-OFDM symbols) and SC-FDMA symbols (or DFT-s-OFDM symbols).

[0069] Table 1 below shows the number of symbols per slot according to the SCS setting (μ) when normal CP is used ( ), number of slots per frame( ) and the number of slots per subframe( ) exemplifies.

[0070]

[0071] Table 2 shows the number of symbols per slot, the number of slots per frame, and the number of slots per subframe according to the SCS when an extended CP is used.

[0072]

[0073] In an NR system, the OFDM(A) numerology (e.g., SCS, CP length, etc.) can be configured differently among multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., subframe, slot, or TTI) (collectively referred to as TU (Time Unit) for convenience) composed of the same number of symbols can be configured differently among the merged cells.

[0074] In NR, multiple numerologies or SCSs may be supported to support various 5G services. For example, if the SCS is 15 kHz, a wide area in traditional cellular bands may be supported, and if the SCS is 30 kHz / 60 kHz, dense-urban, lower latency, and wider carrier bandwidth may be supported. If the SCS is 60 kHz or higher, a bandwidth greater than 24.25 GHz may be supported to overcome phase noise.

[0075] The NR frequency band can be defined by two types of frequency ranges. The two types of frequency ranges may be FR1 and FR2. The numerical values ​​of the frequency ranges may change, for example, as shown in Table 3 below. Among the frequency ranges used in an NR system, FR1 may mean the “sub 6 GHz range” and FR2 may mean the “above 6 GHz range” and may be referred to as millimeter wave (mmW).

[0076]

[0077] As described above, the numerical value of the frequency range of the NR system may change. For example, FR1 may include a band of 410 MHz to 7125 MHz as shown in Table 4 below. That is, FR1 may include a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher. For example, the frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher included within FR1 may include an unlicensed band. The unlicensed band may be used for various purposes, for example, for communication for vehicles (e.g., autonomous driving).

[0078]

[0079] FIG. 7 shows a slot structure of an NR frame according to one embodiment of the present disclosure.

[0080] Referring to FIG. 7, a slot contains multiple symbols in the time domain. For example, in the case of a normal CP, one slot may contain 14 symbols, but in the case of an extended CP, one slot may contain 12 symbols. Alternatively, in the case of a normal CP, one slot may contain 7 symbols, but in the case of an extended CP, one slot may contain 6 symbols.

[0081] A carrier includes multiple subcarriers in the frequency domain. A Resource Block (RB) can be defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A Bandwidth Part (BWP) can be defined as multiple consecutive (P)RBs ((Physical) Resource Blocks) in the frequency domain and can correspond to a single numerology (e.g., SCS, CP length, etc.). A carrier can include up to N (e.g., 5) BWPs. Data communication can be performed through the active BWPs. Each element can be referred to as a Resource Element (RE) in a resource grid and can be mapped to a single complex symbol.

[0082] Meanwhile, a wireless interface between terminals or a wireless interface between a terminal and a network may be composed of L1, L2, and L3 layers. In various embodiments of the present disclosure, L1 layer may refer to the physical layer. Additionally, for example, L2 layer may refer to at least one of the MAC layer, RLC layer, PDCP layer, and SDAP layer. Additionally, for example, L3 layer may refer to the RRC layer.

[0083] V2X or SL (sidelink) communication will be explained below.

[0084] FIG. 8 illustrates a radio protocol architecture for SL communication according to one embodiment of the present disclosure. Specifically, FIG. 8(a) illustrates a user plane protocol stack of LTE, and FIG. 8(b) illustrates a control plane protocol stack of LTE.

[0085] FIG. 9 illustrates a radio protocol architecture for SL communication according to one embodiment of the present disclosure. Specifically, FIG. 9 (a) illustrates a user plane protocol stack of NR, and FIG. 9 (b) illustrates a control plane protocol stack of NR.

[0086] Resource allocation in SL is explained below.

[0087] FIG. 10 illustrates a procedure in which a terminal performs V2X or SL communication according to a transmission mode, in accordance with one embodiment 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.

[0088] For example, FIG. 10(a) illustrates a terminal operation associated with LTE transmission mode 1 or LTE transmission mode 3. Or, for example, FIG. 10(a) illustrates a terminal operation associated with 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.

[0089] For example, FIG. 10(b) illustrates a terminal operation associated with LTE transmission mode 2 or LTE transmission mode 4. Or, for example, FIG. 10(b) illustrates a terminal operation associated with NR resource allocation mode 2.

[0090] Referring to FIG. 10(a), in LTE transmission mode 1, LTE transmission mode 3, or NR resource allocation mode 1, the base station can schedule SL resources to be used by the terminal for SL transmission. For example, the base station can perform resource scheduling to terminal 1 via PDCCH (more specifically, DCI (Downlink Control Information)), and terminal 1 can perform V2X or SL communication with terminal 2 according to the resource scheduling. For example, terminal 1 can transmit SCI (Sidelink Control Information) to terminal 2 via PSCCH (Physical Sidelink Control Channel) and then transmit data based on the SCI to terminal 2 via PSSCH (Physical Sidelink Shared Channel).

[0091] For example, in NR resource allocation mode 1, a terminal may receive or be allocated resources from a base station for one or more SL transmissions of a single TB (Transport Block) through a dynamic grant. For example, the base station may provide the terminal with resources for the transmission of PSCCH and / or PSSCH using a dynamic grant. For example, the transmitting terminal may report SL HARQ (Hybrid Automatic Repeat Request) feedback received from the receiving terminal to the base station. In this case, the PUCCH resources and timing for reporting the SL HARQ feedback to the base station may be determined based on the indication in the PDCCH for the base station to allocate resources for SL transmission.

[0092] For example, DCI may represent a slot offset between the DCI reception and the first SL transmission scheduled by the DCI. For example, the minimum gap between the DCI scheduling the SL transmission resource and the first scheduled SL transmission resource may not be smaller than the processing time of the terminal.

[0093] For example, in NR resource allocation mode 1, the terminal may periodically receive or be allocated a set of resources from the base station for multiple SL transmissions through a configured grant. For example, the configured grant may include configured grant type 1 or configured grant type 2. For example, the terminal may determine the TB to be transmitted in each occasion indicated by the given configured grant.

[0094] For example, a base station can allocate SL resources to terminals on the same carrier and can allocate SL resources to terminals on different carriers.

[0095] For example, an NR base station can control LTE-based SL communication. For example, an NR base station can transmit an NR DCI to a terminal to schedule LTE SL resources. In this case, for example, a new RNTI may be defined to scramble the NR DCI. For example, the terminal may include an NR SL module and an LTE SL module.

[0096] For example, after a terminal including an NR SL module and an LTE SL module receives an NR SL DCI from a gNB, the NR SL module may convert the NR SL DCI to LTE DCI Type 5A, and the NR SL module may transmit the LTE DCI Type 5A to the LTE SL module in X ms increments. For example, after the LTE SL module receives the LTE DCI Format 5A from the NR SL module, the LTE SL module may apply enable and / or disable to the first LTE subframe after Z ms. For example, X may be dynamically represented using fields of the DCI. For example, the minimum value of X may vary depending on the UE capability. For example, the terminal may report a single value depending on the UE capability. For example, X may be a positive number.

[0097] Referring to FIG. 10(b), in LTE transmission mode 2, LTE transmission mode 4, or NR resource allocation mode 2, the terminal can determine an SL transmission resource within an SL resource set by the base station / network or a preset SL resource. For example, the set SL resource or the preset SL resource may be a resource pool. For example, the terminal may autonomously select or schedule a resource for SL transmission. For example, the terminal may perform SL communication by selecting a resource itself within the set resource pool. For example, the terminal may select a resource itself within a selection window by performing a sensing and resource (re)selection procedure. For example, the sensing may be performed on a subchannel basis. Then, Terminal 1, having selected a resource itself within the resource pool, can transmit an SCI to Terminal 2 via PSCCH, and then transmit data based on the SCI to Terminal 2 via PSSCH.

[0098] For example, a terminal can assist in selecting SL resources for other terminals. For example, in NR resource allocation mode 2, a terminal can receive a configured grant for SL transmission. For example, in NR resource allocation mode 2, a terminal can schedule SL transmissions for other terminals. For example, in NR resource allocation mode 2, a terminal can reserve SL resources for blind retransmission.

[0099] For example, in NR resource allocation mode 2, the first terminal may instruct the second terminal to prioritize SL transmission using SCI. For example, the second terminal may decode said SCI, and the second terminal may perform sensing and / or resource (re)selection based on said priority. For example, said resource (re)selection procedure may include the step of the second terminal identifying candidate resources in a resource selection window and the step of the second terminal selecting a resource for (re)transmission from among the identified candidate resources. For example, the resource selection window may be a time interval in which the terminal selects a resource for SL transmission. For example, after the second terminal triggers resource (re)selection, the resource selection window may start at T1 ≥ 0, and the resource selection window may be limited by the remaining packet delay budget of the second terminal. For example, in the step where the second terminal identifies candidate resources in a resource selection window, if a specific resource is indicated by an SCI received by the second terminal from the first terminal and the L1 SL RSRP measurement for said specific resource exceeds an SL RSRP threshold, the second terminal may not determine said specific resource as a candidate resource. For example, the SL RSRP threshold may be determined based on the priority of SL transmission indicated by the SCI received by the second terminal from the first terminal and the priority of SL transmission on the resource selected by the second terminal.

[0100] For example, the L1 SL RSRP can be measured based on the SL DMRS (Demodulation Reference Signal). For example, one or more PSSCH DMRS patterns in the time domain may be set or pre-set for each resource pool. For example, PSSCH DMRS setting type 1 and / or type 2 may be identical or similar to the frequency domain pattern of the PSSCH DMRS. For example, the exact DMRS pattern may be indicated by the SCI. For example, in NR resource allocation mode 2, the transmitting terminal may select a specific DMRS pattern from among the DMRS patterns set or pre-set for the resource pool.

[0101] For example, in NR resource allocation mode 2, based on a sensing and resource (re)selection procedure, the transmitting terminal can perform the initial transmission of a Transport Block (TB) without reservation. For example, based on a sensing and resource (re)selection procedure, the transmitting terminal can reserve an SL resource for the initial transmission of a second TB using an SCI associated with a first TB.

[0102] For example, in NR resource allocation mode 2, the terminal may reserve resources for feedback-based PSSCH retransmissions through signaling associated with previous transmissions of the same TB (Transport Block). For example, the maximum number of SL resources reserved by a single transmission, including the current transmission, may be 2, 3, or 4. For example, the maximum number of SL resources may be the same regardless of whether HARQ feedback is enabled. For example, the maximum number of HARQ (re)transmissions for a single TB may be limited by a setting or preset. For example, the maximum number of HARQ (re)transmissions may be up to 32. For example, if there is no setting or preset, the maximum number of HARQ (re)transmissions may be unspecified. For example, the setting or preset may be for the transmitting terminal. For example, in NR resource allocation mode 2, HARQ feedback may be supported to release resources that are not being used by the terminal.

[0103] For example, in NR resource allocation mode 2, a terminal may use an SCI to direct one or more subchannels and / or slots used by said terminal to another terminal. For example, a terminal may use an SCI to direct one or more subchannels and / or slots reserved by said terminal for PSSCH (re)transmission to another terminal. For example, the minimum allocation unit of an SL resource may be a slot. For example, the size of a subchannel may be set for the terminal or pre-set.

[0104] The following describes SCI (Sidelink Control Information).

[0105] Control information transmitted by a base station to a terminal via PDCCH is referred to as DCI (Downlink Control Information), whereas control information transmitted by a terminal to another terminal via PSCCH may be referred to as SCI. For example, a terminal may know the start symbol of the PSCCH and / or the number of symbols in the PSCCH before decoding the PSCCH. For example, SCI may include SL scheduling information. For example, a terminal may transmit at least one SCI to another terminal to schedule the PSSCH. For example, one or more SCI formats may be defined.

[0106] For example, a transmitting terminal can transmit an SCI over a PSCCH to a receiving terminal. The receiving terminal can decode one SCI to receive the PSSCH from the transmitting terminal.

[0107] For example, a transmitting terminal may transmit two consecutive SCIs (e.g., 2-stage SCIs) to a receiving terminal over a PSCCH and / or PSSCH. The receiving terminal may decode the two consecutive SCIs (e.g., 2-stage SCIs) to receive the PSSCH from the transmitting terminal. For example, if the SCI constituent fields are divided into two groups considering a (relatively) high SCI payload size, the SCI containing the first group of SCI constituent fields may be referred to as the first SCI or 1st SCI, and the SCI containing the second group of SCI constituent fields may be referred to as the second SCI or 2nd SCI. For example, the transmitting terminal may transmit the first SCI to the receiving terminal via the PSCCH. For example, the transmitting terminal may transmit the second SCI to the receiving terminal over the PSCCH and / or PSSCH. For example, the second SCI may be transmitted to a receiving terminal via a (separate) PSCCH, or may be transmitted piggybacked with data via a PSSCH. For example, two consecutive SCIs may be applied to different transmissions (e.g., unicast, broadcast, or groupcast).

[0108] For example, a transmitting terminal may transmit some or all of the following information to a receiving terminal through an SCI. Here, for example, the transmitting terminal may transmit some or all of the following information to a receiving terminal through a first SCI and / or a second SCI.

[0109] - PSSCH and / or PSCCH-related resource allocation information, e.g., time / frequency resource locations / counts, resource reservation information (e.g., periods), and / or

[0110] - SL CSI Report Request Indicator or SL (L1) RSRP (and / or SL (L1) RSRQ and / or SL (L1) RSSI) Report Request Indicator, and / or

[0111] - SL CSI transmission indicator (on PSSCH) (or SL (L1) RSRP (and / or SL (L1) RSRQ and / or SL (L1) RSSI) information transmission indicator), and / or

[0112] - MCS information, and / or

[0113] - Transmission power information, and / or

[0114] - L1 destination ID information and / or L1 source ID information, and / or

[0115] - SL HARQ process ID information, and / or

[0116] - NDI (New Data Indicator) information, and / or

[0117] - RV (Redundancy Version) information, and / or

[0118] - QoS information (related to transmission traffic / packets), e.g., priority information, and / or

[0119] - SL CSI-RS transmission indicator or information on the number of (transmitting) SL CSI-RS antenna ports

[0120] - Location information of the transmitting terminal or location (or distance area) information of the target receiving terminal (for which SL HARQ feedback is requested), and / or

[0121] - Information on reference signals (e.g., DMRS, etc.) related to the decoding and / or channel estimation of data transmitted via PSSCH, e.g., information related to the pattern of the (time-frequency) mapping resource of the DMRS, rank information, antenna port index information;

[0122] For example, the first SCI may include information related to channel sensing. For example, the receiving terminal may decode the second SCI using PSSCH DMRS. A polar code used in PDCCH may be applied to the second SCI. For example, in a resource pool, the payload size of the first SCI may be the same for unicast, groupcast, and broadcast. After decoding the first SCI, the receiving terminal does not need to perform blind decoding of the second SCI. For example, the first SCI may include scheduling information for the second SCI.

[0123] Meanwhile, in various embodiments of the present disclosure, since the transmitting terminal can transmit at least one of SCI, the first SCI, and / or the second SCI to the receiving terminal via PSCCH, PSCCH may be replaced / substituted with at least one of SCI, the first SCI, and / or the second SCI. And / or, for example, SCI may be replaced / substituted with at least one of PSCCH, the first SCI, and / or the second SCI. And / or, for example, since the transmitting terminal can transmit the second SCI to the receiving terminal via PSSCH, PSSCH may be replaced / substituted with the second SCI.

[0124] Meanwhile, when using a UE-to-UE relay, the link quality between the source UE and the relay UE, as well as the link quality between the relay UE and the destination UE, must be guaranteed to transmit data from the source UE to the destination UE. To satisfy the QoS requirements (e.g., reliability, latency) of a specific service transmitted by the source UE, the link with the relatively lower quality between the link quality between the source UE and the relay UE and the link quality between the relay UE and the destination UE exerts a dominant influence on the overall link quality from the source UE to the final destination UE. In other words, improving the lower link quality plays a crucial role in enhancing the overall link quality.

[0125] In one embodiment, a case is considered where a source UE performs communication through a relay UE, and the link quality from the source UE to the final destination UE (the link from the source to the relay UE and the link from the relay to the destination UE) does not satisfy the service requirements. In such a case, the operation related to resource reselection of the relay UE, and the conditions and methods for the source UE to trigger the operation of the relay UE are proposed. In the description of the invention below, the source UE refers to the UE transmitting data, and it is obvious that the source UE may also be the destination UE depending on the direction of data transmission. Additionally, the source UE may be replaced with a base station (or another relay UE).

[0126] A relay User Equipment (UE) according to one embodiment may measure the link quality between the source UE and the relay UE (S1201 in FIG. 12) and receive information related to the link quality between the relay UE and the remote UE from the remote UE (S1202 in FIG. 12). If the relay UE does not know the Quality of Service (QoS) required for the message, it may perform resource reselection based on the difference between the link quality between the source UE and the relay UE and the link quality between the relay UE and the remote UE being greater than a preset value. The resource being reselected here may refer to a resource used between the relay UE and the remote UE.

[0127] In other words, the relay UE receives a report on the link quality between the relay UE and the destination UE, and if it determines that the reported link quality does not satisfy the QoS of the message currently being transmitted, it may (re)configure the resource.

[0128] In particular, when the relay UE does not know the QoS level required by the message, the following operation is possible. If the difference between the measured / estimated link quality between the source UE and the relay UE and the reported link quality between the relay UE and the destination UE exceeds a threshold, the relay UE may attempt resource reselection. For example, if the measured / estimated link quality between the source UE and the relay UE is significantly better than the link quality reported by the destination UE, resource reselection may be performed to improve the link quality between the relay UE and the destination UE, which have a worse link quality. In this case as well, resource reselection is performed only when the congestion level is below a threshold, making it highly likely that a better resource will be selected.

[0129] Meanwhile, if the relay UE knows the QoS required by the message, the relay UE may perform resource reselection based on the fact that the link quality between the relay UE and the remote UE does not satisfy the QoS. Here, the QoS may be received by the relay UE from the source UE. For this operation to work, the relay UE must know in advance the QoS value required by the message currently being transmitted. The source UE may provide the corresponding QoS value.

[0130] The aforementioned resource reselection may be performed when the congestion level is below a certain value. In other words, this behavior may be permitted only when the resource pool-related congestion level is below a certain value. That is, the purpose is to increase the likelihood of selecting a better resource by triggering resource reselection only in environments where there is a high probability that the quality of the reselected resource will be better than the existing resource.

[0131] By configuring as described above, it is possible to efficiently manage link quality by performing resource reselection after comparing the quality of two links, compared to conventional technology that performs relay reselection when the link quality between the relay and the remote deteriorates.

[0132] As an apparatus related to the above embodiment, a relay User Equipment (UE) comprises at least one processor; and at least one computer memory that can be operably connected to the at least one processor and stores instructions that cause the at least one processor to perform operations when executed, wherein the operations include: measuring the link quality between a source UE and the relay UE; and receiving information from a remote UE regarding the link quality between the relay UE and the remote UE, wherein if the relay UE does not know the Quality of Service (QoS) required for the message, it may perform resource reselection based on the difference between the link quality between the source UE and the relay UE and the link quality between the relay UE and the remote UE being greater than a preset value.

[0133] Additionally, a processor for performing operations for relay User Equipment (UE), wherein the operations include: measuring the link quality between a source UE and the relay UE; and receiving information from a remote UE regarding the link quality between the relay UE and the remote UE, wherein if the relay UE does not know the Quality of Service (QoS) required for a message, the processor performs resource reselection based on the difference between the link quality between the source UE and the relay UE and the link quality between the relay UE and the remote UE being greater than a preset value.

[0134] Additionally, in a non-volatile computer-readable storage medium storing at least one computer program that includes instructions for at least one processor to perform operations for a UE when executed by at least one processor, said operations include: measuring the link quality between a source UE and the relay UE; and receiving information from a remote UE regarding the link quality between the relay UE and the remote UE, and if the relay UE does not know the Quality of Service (QoS) required for the message, it may perform resource reselection based on the difference between the link quality between the source UE and the relay UE and the link quality between the relay UE and the remote UE being greater than a preset value.

[0135] The above description is an example in which a relay UE performs decision-making and resource reselection, but as another embodiment, it may be performed by a source UE, and the following describes this. The following description may be performed independently of the operation of the relay UE or in a combined form.

[0136] The source UE must be able to trigger (request) the relay UE to report the link quality between the source UE and the relay UE as well as the link quality between the relay UE and the destination UE. That is, based on the information regarding the link quality between the relay UE and the remote UE reported to the source UE, the relay UE may receive resource reselection triggering from the source UE. Here, the quality information that the relay UE must transmit to the source UE may be at least one of SL-RSRP / RSSI / RSRQ, SL-CSI, k (k>=1) or more consecutive NACKs, and l (l>=1) or more consecutive OOS (Out-Of-Sync) occurrences measurable in the communication between the source UE and the relay UE, and at least one of SL-RSRP / RSSI / RSRQ, SL-CSI, m (m>=1) or more consecutive NACKs, and n (n>=1) or more consecutive OOS (Out-Of-Sync) occurrences measurable in the communication between the relay UE and the destination UE. The information may be information directly measured by the relay UE or information received from the destination UE.

[0137] In the case of communications not configured to send ACK / NACK, the source UE performs blind retransmission; in this case, the relay UE may report the (average) number of times the same message has been received and decoded to the source UE as part of the information reporting link quality. Since the source UE knows the (average) number of times it performs blind retransmission, it can estimate, estimate, or derive the link quality through this. In this case, if a signal has been received but decoding is impossible, the reception count may be calculated as 0 and reported.

[0138] Based on information reported by the relay UE, if it is determined that it is difficult to reliably satisfy service requirements because the link quality between the source UE and the relay UE is above a specific threshold while the link quality between the relay UE and the destination UE is below the threshold, the following actions may be performed.

[0139] The source UE must be able to trigger (request) the relay UE to reselect the resources being used for communication between the relay UE and the destination UE.

[0140] In this case, the action may be permitted only when the resource pool congestion level is below a certain value. In other words, the purpose is to increase the likelihood of selecting a better resource by triggering resource reselection only in environments where there is a high probability that the quality of the reselected resource will be better than the existing resource. Additionally, this aims to reduce the burden of finding a new relay UE and establishing a sidelink connection by allowing the currently connected relay UE to do its best before triggering relay reselection.

[0141] Example of a communication system to which the present invention is applied

[0142] Although not limited thereto, the various descriptions, functions, procedures, proposals, methods, and / or flowcharts of the invention disclosed in this document may be applied to various fields requiring wireless communication / connection (e.g., 5G) between devices.

[0143] Examples are provided in more detail below with reference to the drawings. In the following drawings and descriptions, the same reference numerals may represent the same or corresponding hardware blocks, software blocks, or function blocks unless otherwise described.

[0144] FIG. 13 illustrates a communication system (1) to which the present invention is applied.

[0145] Referring to FIG. 13, the communication system (1) to which the present invention applies includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using 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 Thing) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with wireless communication functions, an autonomous vehicle, a vehicle capable of performing communication between vehicles, 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 HMDs (Head-Mounted Devices), HUDs (Head-Up Displays) equipped in vehicles, televisions, smartphones, computers, wearable devices, home appliances, digital signage, vehicles, robots, etc. Portable devices may include smartphones, smartpads, wearable devices (e.g., smartwatches, smart glasses), computers (e.g., laptops, etc.). Home appliances may include TVs, refrigerators, washing machines, etc. IoT devices may include sensors, smart meters, etc. For example, base stations and networks may be implemented as wireless devices, and a specific wireless device (200a) may operate as a base station / network node to other wireless devices.

[0146] Wireless devices (100a to 100f) can be connected to a network (300) through a base station (200). Artificial Intelligence (AI) technology may be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) through the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. The wireless devices (100a to 100f) may communicate with each other through the base station (200) / network (300), but they may 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). Also, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0147] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base station (200) and base station (200) / base station (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 inter-base station communication (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 / from each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, based on various proposals of the present invention, at least some of the following may be performed: 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.), resource allocation processes, etc.

[0148] Example of a wireless device to which the present invention is applied

[0149] FIG. 14 illustrates a wireless device that can be applied to the present invention.

[0150] Referring to FIG. 14, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device (100), the second wireless device (200)} may correspond to {wireless device (100x), base station (200)} and / or {wireless device (100x), wireless device (100x)} of FIG. 13.

[0151] The first wireless device (100) includes one or more processors (102) and one or more memories (104), and may additionally include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memory (104) and / or transceivers (106) and may be configured to implement the descriptions, functions, procedures, proposals, methods and / or flowcharts of operation disclosed in this document. For example, the processor (102) may process information within the memory (104) to generate a first information / signal and then transmit a wireless signal containing the first information / signal through the transceiver (106). Additionally, the processor (102) may receive a wireless signal containing a second information / signal through the transceiver (106) and then store information obtained from the 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 store software code containing instructions for performing some or all of the processes controlled by the processor (102) or for performing the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement 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 through one or more antennas (108). The transceiver (106) may include a transmitter and / or receiver. The transceiver (106) may be combined with an RF (Radio Frequency) unit. In the present invention, the wireless device may refer to a communication modem / circuit / chip.

[0152] The second wireless device (200) includes one or more processors (202) and one or more memories (204), and may additionally include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memory (204) and / or transceivers (206) and may be configured to implement the descriptions, functions, procedures, proposals, methods and / or operation sequences disclosed in this document. For example, the processor (202) may process information within the memory (204) to generate a third information / signal and then transmit a wireless signal containing the third information / signal through the transceiver (206). Additionally, the processor (202) may receive a wireless signal containing a fourth information / signal through the transceiver (206) and then store information obtained from the signal processing of the fourth information / signal 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 store software code containing instructions for performing some or all of the processes controlled by the processor (202) or for performing the descriptions, functions, procedures, proposals, methods, and / or operation sequences 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 through one or more antennas (208). The transceiver (206) may include a transmitter and / or receiver. The transceiver (206) may be interchangeable with an RF unit. In the present invention, the wireless device may refer to a communication modem / circuit / chip.

[0153] Hereinafter, 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 Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation 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 flowcharts of operation disclosed in this document. One or more processors (102, 202) may generate a signal (e.g., baseband signal) containing a PDU, SDU, message, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in this document and provide it to one or more transceivers (106, 206). One or more processors (102, 202) may receive a signal (e.g., baseband signal) from one or more transceivers (106, 206) and may obtain a PDU, SDU, message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed in this document.

[0154] One or more processors (102, 202) may be referred to as a controller, microcontroller, microprocessor, or 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 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. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document may be contained in 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, proposals, methods, and / or operation sequences disclosed in this document may be implemented using firmware or software in the form of code, instructions, and / or sets of instructions.

[0155] One or more memories (104, 204) may be connected to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, code, instructions, and / or commands. One or more memories (104, 204) may be composed of ROM, RAM, EPROM, flash memory, hard drive, registers, cache memory, computer read storage media, and / or combinations thereof. One or more memories (104, 204) may be located inside and / or outside of one or more processors (102, 202). Additionally, one or more memories (104, 204) may be connected to one or more processors (102, 202) through various technologies such as wired or wireless connections.

[0156] One or more transceivers (106, 206) may transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or operation flowcharts, etc., of this document to one or more other devices. One or more transceivers (106, 206) may receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or operation flowcharts, etc., disclosed in this document from one or more other devices. For example, one or more transceivers (106, 206) may be connected to one or more processors (102, 202) and may transmit and receive wireless signals. For example, one or more processors (102, 202) may 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 connected 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, etc., as described in the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document through 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 the received wireless signal / channel, etc. from an RF band signal to a baseband signal in order to process the received user data, control information, wireless signal / channel, etc. using one or more processors (102, 202).One or more transceivers (106, 206) can convert user data, control information, wireless signals / channels, etc. processed using one or more processors (102, 202) from baseband signals to RF band signals. To this end, one or more transceivers (106, 206) may include (analog) oscillators and / or filters.

[0157] Examples of vehicles or autonomous vehicles to which the present invention is applied

[0158] FIG. 15 illustrates a vehicle or autonomous vehicle to which the present invention applies. The vehicle or autonomous vehicle may be implemented as a mobile robot, vehicle, train, manned / unmanned aerial vehicle (AV), ship, etc.

[0159] Referring to FIG. 15, 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 part of the communication unit (110).

[0160] 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, roadside base stations (Roadside units), etc.), and servers. The control unit (120) can perform various operations by controlling elements of the vehicle or autonomous vehicle (100). The control unit (120) may include an Electronic Control Unit (ECU). The driving unit (140a) can drive the vehicle or autonomous vehicle (100) on the ground. The driving unit (140a) may include an engine, motor, power train, wheels, brakes, steering device, etc. The power supply unit (140b) supplies power to the vehicle or autonomous vehicle (100) and may include wired / wireless charging circuits, batteries, 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 inclination sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / reverse 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 technologies such as maintaining the driving lane, technologies for automatically adjusting speed such as adaptive cruise control, technologies for automatically driving along a predetermined path, and technologies for automatically setting a path and driving when a destination is set.

[0161] 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 path and a driving plan based on the acquired data. The control unit (120) can control the drive unit (140a) so that the vehicle or the autonomous vehicle (100) moves along the autonomous driving path according to the driving plan (e.g., speed / direction control). During autonomous driving, the communication unit (110) can acquire the latest traffic information data from an external server non-periodically and can acquire surrounding traffic information data from surrounding vehicles. Additionally, 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 path and the driving plan based on the newly acquired data / information. The communication unit (110) can transmit information regarding the vehicle location, autonomous driving path, driving plan, etc. to an external server. An external server can predict traffic information data in advance using AI technology, etc., based on information collected from vehicles or autonomous vehicles, and can provide the predicted traffic information data to vehicles or autonomous vehicles.

[0162] AR / VR and vehicle examples to which the present invention is applied

[0163] FIG. 16 illustrates a vehicle to which the present invention is applied. The vehicle may also be implemented as a means of transportation, a train, an aircraft, a ship, etc.

[0164] Referring to FIG. 16, the vehicle (100) may include a communication unit (110), a control unit (120), a memory unit (130), an input / output unit (140a), and a position measuring unit (140b).

[0165] The communication unit (110) can transmit and receive signals (e.g., data, control signals, etc.) with external devices such as other vehicles or base stations. The control unit (120) can control the components of the vehicle (100) to perform various operations. The memory unit (130) can store data / parameters / programs / codes / commands that support various functions of the vehicle (100). The input / output unit (140a) can output AR / VR objects based on information within the memory unit (130). The input / output unit (140a) may include a HUD. The position measurement unit (140b) can acquire position information of the vehicle (100). The position information may include absolute position information of the vehicle (100), position information within the driving line, acceleration information, position information relative to surrounding vehicles, etc. The position measurement unit (140b) may include GPS and various sensors.

[0166] For example, the communication unit (110) of the vehicle (100) can receive map information, traffic information, etc. from an external server and store it in the memory unit (130). The location measurement unit (140b) can acquire vehicle location information through GPS and various sensors and store it in the memory unit (130). The control unit (120) creates a virtual object based on map information, traffic information, and vehicle location information, etc., and the input / output unit (140a) can display the created virtual object on the glass window inside the vehicle (1410, 1420). In addition, the control unit (120) can determine whether the vehicle (100) is operating normally within the driving line based on the vehicle location information. If the vehicle (100) deviates abnormally from the driving line, the control unit (120) can display a warning on the glass window inside the vehicle through the input / output unit (140a). Additionally, the control unit (120) can broadcast a warning message regarding a driving abnormality to surrounding vehicles through the communication unit (110). Depending on the situation, the control unit (120) can transmit the vehicle's location information and information regarding the driving / vehicle abnormality to relevant authorities through the communication unit (110).

[0167] Example of an XR device to which the present invention is applied

[0168] FIG. 17 illustrates an XR device to which the present invention is applied. The XR device may be implemented as an HMD, a Head-Up Display (HUD) equipped in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, digital signage, a vehicle, a robot, etc.

[0169] Referring to FIG. 17, the XR device (100a) may include a communication unit (110), a control unit (120), a memory unit (130), an input / output unit (140a), a sensor unit (140b), and a power supply unit (140c).

[0170] The communication unit (110) can transmit and receive signals (e.g., media data, control signals, etc.) with external devices such as other wireless devices, mobile devices, or media servers. The media data may include video, images, sound, etc. The control unit (120) can perform various operations by controlling the components of the XR device (100a). For example, the control unit (120) may be configured to control and / or perform procedures such as video / image acquisition, (video / image) encoding, metadata generation, and processing. The memory unit (130) may store data / parameters / programs / codes / commands required for driving the XR device (100a) or creating an XR object. The input / output unit (140a) acquires control information, data, etc. from the outside and can output the created XR object. The input / output unit (140a) may include a camera, microphone, user input unit, display unit, speaker and / or haptic module, etc. The sensor unit (140b) can obtain XR device status, surrounding environment information, user information, etc. The sensor unit (140b) may include a proximity sensor, an illuminance sensor, an accelerometer, a magnetic sensor, a gyroscope, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone and / or radar, etc. The power supply unit (140c) supplies power to the XR device (100a) and may include a wired / wireless charging circuit, a battery, etc.

[0171] For example, the memory unit (130) of the XR device (100a) may contain information (e.g., data, etc.) necessary for creating an XR object (e.g., AR / VR / MR object). The input / output unit (140a) may receive a command to operate the XR device (100a) from the user, and the control unit (120) may operate the XR device (100a) according to the user's operation command. For example, if the user intends to watch movies, news, etc. through the XR device (100a), the control unit (120) may transmit content request information to another device (e.g., mobile device (100b)) or a media server through the communication unit (130). The communication unit (130) may download / stream content such as movies, news, etc. from another device (e.g., mobile device (100b)) or a media server to the memory unit (130). The control unit (120) controls and / or performs procedures such as video / image acquisition, (video / image) encoding, and metadata generation / processing for the content, and can generate / output an XR object based on information about the surrounding space or real object acquired through the input / output unit (140a) / sensor unit (140b).

[0172] Additionally, the XR device (100a) is wirelessly connected to the mobile device (100b) through the communication unit (110), and the operation of the XR device (100a) can be controlled by the mobile device (100b). For example, the mobile device (100b) can act as a controller for the XR device (100a). To this end, the XR device (100a) can acquire three-dimensional position information of the mobile device (100b), and then generate and output an XR object corresponding to the mobile device (100b).

[0173] Example of a robot to which the present invention is applied

[0174] FIG. 18 illustrates a robot to which the present invention is applied. Robots can be classified into industrial, medical, household, military, etc., depending on the purpose or field of use.

[0175] Referring to FIG. 18, the robot (100) may include a communication unit (110), a control unit (120), a memory unit (130), an input / output unit (140a), a sensor unit (140b), and a driving unit (140c).

[0176] The communication unit (110) can transmit and receive signals (e.g., driving information, control signals, etc.) with external devices such as other wireless devices, other robots, or control servers. The control unit (120) can control the components of the robot (100) to perform various operations. The memory unit (130) can store data / parameters / programs / codes / commands that support various functions of the robot (100). The input / output unit (140a) can acquire information from outside the robot (100) and output information to outside the robot (100). The input / output unit (140a) may include a camera, microphone, user input unit, display unit, speaker and / or haptic module, etc. The sensor unit (140b) can obtain internal information of the robot (100), surrounding environment information, user information, etc. The sensor unit (140b) may include a proximity sensor, an illuminance sensor, an accelerometer, a magnetic sensor, a gyroscope, an inertial sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone, a radar, etc. The driving unit (140c) may perform various physical movements, such as moving robot joints. Additionally, the driving unit (140c) may enable the robot (100) to travel on the ground or fly in the air. The driving unit (140c) may include an actuator, a motor, a wheel, a brake, a propeller, etc.

[0177] Example of an AI device to which the present invention is applied

[0178] FIG. 19 illustrates an AI device to which the present invention is applied. The AI ​​device may be implemented as a stationary device or a mobile device, such as a TV, projector, smartphone, PC, laptop, digital broadcasting terminal, tablet PC, wearable device, set-top box (STB), radio, washing machine, refrigerator, digital signage, robot, vehicle, etc.

[0179] Referring to FIG. 19, the AI ​​device (100) may include a communication unit (110), a control unit (120), a memory unit (130), an input / output unit (140a / 140b), a learning processor unit (140c), and a sensor unit (140d).

[0180] The communication unit (110) can transmit and receive wired and wireless signals (e.g., sensor information, user input, learning model, control signal, etc.) with external devices such as other AI devices (e.g., 100x, 200, 400 in FIG. 13) or AI servers (e.g., 400 in FIG. 13) using wired and wireless communication technology. To do this, the communication unit (110) can transmit information within the memory unit (130) to an external device or transmit signals received from an external device to the memory unit (130).

[0181] The control unit (120) can determine at least one executable operation of the AI ​​device (100) based on information determined or generated using a data analysis algorithm or a machine learning algorithm. The control unit (120) can perform the determined operation by controlling the components of the AI ​​device (100). For example, the control unit (120) can request, search, receive, or utilize data from the learning processor unit (140c) or the memory unit (130), and can control the components of the AI ​​device (100) to execute a predicted operation or an operation determined to be desirable among at least one executable operation. Additionally, the control unit (120) can collect historical information, including the operation content of the AI ​​device (100) or user feedback regarding the operation, and store it in the memory unit (130) or the learning processor unit (140c), or transmit it to an external device such as an AI server (Fig. 13, 400). The collected historical information can be used to update the learning model.

[0182] The memory unit (130) can store data that supports various functions of the AI ​​device (100). For example, the memory unit (130) can store data obtained from the input unit (140a), data obtained from the communication unit (110), output data from the learning processor unit (140c), and data obtained from the sensing unit (140). Additionally, the memory unit (130) can store control information and / or software code required for the operation / execution of the control unit (120).

[0183] The input unit (140a) can acquire various types of data from outside the AI ​​device (100). For example, the input unit (140a) can acquire training data for model training and input data to which the training model is applied. The input unit (140a) may include a camera, a microphone and / or a user input unit, etc. The output unit (140b) can generate output related to visual, auditory, or tactile senses, etc. The output unit (140b) may include a display unit, a speaker and / or a haptic module, etc. The sensing unit (140) can obtain at least one of internal information of the AI ​​device (100), surrounding environment information of the AI ​​device (100), and user information using various sensors. The sensing unit (140) may include a proximity sensor, an illuminance sensor, an accelerometer, a magnetic sensor, a gyroscope, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone and / or radar, etc.

[0184] The learning processor unit (140c) can train a model composed of an artificial neural network using training data. The learning processor unit (140c) can perform AI processing together with the learning processor unit of the AI ​​server (Fig. 13, 400). The learning processor unit (140c) can process information received from an external device through the communication unit (110) and / or information stored in the memory unit (130). Additionally, the output value of the learning processor unit (140c) can be transmitted to an external device through the communication unit (110) and / or stored in the memory unit (130). Industrial applicability

[0185] The embodiments described above can be applied to various mobile communication systems.

Claims

Claim 1 A method performed by a relay User Equipment (UE), comprising: selecting a resource for communication between the relay UE and the remote UE from a preset resource pool; transmitting Sidelink Control Information (SCI) containing information regarding the selected resource; measuring a first link quality between the source UE and the relay UE; receiving information regarding a second link quality between the relay UE and the remote UE from the remote UE; and, when the Quality of Service (QoS) required for a message transmitted from the source UE is unknown, performing a re-selection of the resource based on the difference between the first link quality and the second link quality being greater than a preset value. Claim 2 delete Claim 3 A method according to claim 1, wherein the reselection of the resource is performed when the condition that the congestion level is below a certain value is satisfied. Claim 4 The method of claim 1 further comprises the step of performing a reselection of the resource based on the fact that the second link quality does not satisfy the QoS when the QoS required for the message is known. Claim 5 The method of claim 1 further comprises the step of receiving information from the source UE that triggers the reselection of the resource based on reporting information related to the second link quality to the source UE; wherein the reselection of the resource is performed based on the information that triggers the reselection of the resource. Claim 6 A relay User Equipment (UE) comprises at least one transceiver; at least one processor; and at least one computer memory that can be operably connected to the at least one processor and stores instructions that cause the at least one processor to perform operations when executed, wherein the operations include selecting a resource for communication between the relay UE and a remote UE from a preset resource pool, transmitting Sidelink Control Information (SCI) containing information regarding the selected resource, measuring a first link quality between a source UE and the relay UE, receiving information regarding a second link quality between the relay UE and the remote UE from the remote UE, and, when the Quality of Service (QoS) required for a message transmitted from the source UE is unknown, performing a resource reselection based on the difference between the first link quality and the second link quality being greater than a preset value. Claim 7 delete Claim 8 In paragraph 6, the above resource reselection is performed when the condition that the congestion level is below a certain value is satisfied, in a relay UE. Claim 9 In paragraph 6, the relay UE further comprises an operation to perform reselection of the resource based on the fact that the second link quality does not satisfy the QoS when the QoS required for the message is known. Claim 10 In claim 6, the operation further includes receiving information from the source UE that triggers the reselection of the resource based on reporting information related to the second link quality to the source UE, and the reselection of the resource is performed based on the information that triggers the reselection of the resource, the relay UE. Claim 11 A processing device comprising: at least one processor; and at least one computer memory that can be operably connected to the at least one processor and stores instructions that, when executed, cause the at least one processor to perform operations, wherein the operations include selecting a resource for communication between a relay UE and a remote UE from a preset resource pool, transmitting Sidelink Control Information (SCI) containing information regarding the selected resource, measuring a first link quality between a source UE and the relay UE, receiving information regarding a second link quality between the relay UE and the remote UE from the remote UE, and, when the Quality of Service (QoS) required for a message transmitted from the source UE is unknown, performing a reselection of a resource based on the difference between the first link quality and the second link quality being greater than a preset value. Claim 12 A nonvolatile computer-readable storage medium storing at least one computer program that, when executed by at least one processor, causes at least one processor to perform operations for relay UE (user equipment), wherein the operations include selecting a resource for communication between the relay UE and a remote UE from a preset resource pool, transmitting Sidelink Control Information (SCI) containing information regarding the selected resource, measuring a first link quality between a source UE and the relay UE, receiving information regarding a second link quality between the relay UE and the remote UE from the remote UE, and, when the Quality of Service (QoS) required for a message transmitted from the source UE is unknown, performing a re-selection of the resource based on the difference between the first link quality and the second link quality being greater than a preset value.

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