Method for performing relay communication and device therefor in wireless communication system

Abstract

A device according to various embodiments may: establish a first connection to a base station and a second connection to a first remote UE for a UE to network (U2N) relay; receive a first message including a layer2 identifier (L2 ID) of the first remote UE through the second connection; and transmit the first message through the first connection.

Description

Method for performing relay communication in a wireless communication system and device for the same

[0001] This relates to a method for performing multi-hop based relay communication in a wireless communication system and a device for doing so.

[0002] 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.

[0003] 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.

[0004] 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.

[0005] 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.

[0006] Figure 1 is a diagram illustrating a comparison between V2X communication based on RAT prior to NR and V2X communication based on NR.

[0007] 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.

[0008] 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.

[0009] Since then, regarding V2X communication, various V2X scenarios have been presented in NR. For example, various V2X scenarios may include vehicle platooning, advanced driving, extended sensors, remote driving, etc.

[0010] 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 said periodic data to reduce or increase the distance between vehicles.

[0011] 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.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] The technical problem that the present invention aims to solve is to provide a method for performing multi-hop based U2N relay communication more accurately and efficiently.

[0016] The technical problems are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

[0017] A method by a first relay UE (User Equipment) according to one aspect comprises the steps of: establishing a first connection toward a base station and a second connection toward a first remote UE for U2N relay (UE to Network); receiving a first message including an L2 ID (layer 2 identifier) ​​of the first remote UE through the second connection; and transmitting the first message through the first connection, wherein the first relay UE can map the L2 ID of the first remote UE to the second connection where the first message was received.

[0018] Alternatively, the method may further include the step of receiving a second message through the first connection; and the step of transmitting the second message through the second connection mapped to the L2 ID of the first remote UE, based on the fact that the second message contains an L2 ID identical to the L2 ID of the first remote UE.

[0019] Alternatively, the first message may be a local ID request message requesting the assignment of a local ID to the first remote UE, and the second message may be a local ID assignment message assigning the local ID to the first remote UE.

[0020] Alternatively, the first message may be a message requesting a System Information Block (SIB) or a message requesting paging monitoring.

[0021] Alternatively, it may further include the step of establishing a third connection toward a second remote UE; the step of receiving a second message through the first connection; and the step of transmitting the second message through one of the second connection and the third connection that is mapped to an L2 ID included in the second message.

[0022] Alternatively, the L2 ID of the first remote UE may be mapped to the second connection where the first message was received, based on the fact that an e2e (end-to-end) bearer between the base station and the first remote UE has not yet been established.

[0023] Alternatively, the second connection may be a direct connection with the first remote UE or a direct connection with a third relay UE that is directly connected to the first remote UE.

[0024] Alternatively, the first message may be a PC5 RRC (Radio Resource Control) message.

[0025] Alternatively, the first connection may be a connection between a second relay UE connected to the base station and the first relay UE.

[0026] According to another aspect, at least one non-transient computer-readable recording medium comprises instructions for performing operations when executed by at least one processor, said operations include establishing a first connection toward a base station and a second connection toward a first remote UE for U2N relay (UE to Network); receiving a first message including an L2 ID (layer 2 identifier) ​​of the first remote UE through the second connection; and transmitting the first message through the first connection, wherein the L2 ID of the remote UE may be mapped to the second connection where the first message was received.

[0027] According to another aspect, a first relay UE (User Equipment) comprises an RF (Radio Frequency) transceiver; and a processor connected to the RF transceiver, wherein the processor controls the RF transceiver to establish a first connection toward a base station and a second connection toward a first remote UE for U2N relay (UE to Network), receives a first message including an L2 ID (layer 2 identifier) ​​of the first remote UE through the second connection, transmits the first message through the first connection, and the L2 ID of the remote UE may be mapped to the second connection where the first message was received.

[0028] A processing device for controlling a first relay UE according to another aspect comprises at least one processor; and at least one memory connected to the at least one processor and storing instructions, wherein the instructions are executed by the at least one processor and cause the first relay UE to: establish a first connection toward a base station and a second connection toward a first remote UE for U2N relay (UE to Network), receive a first message including an L2 ID (layer 2 identifier) ​​of the first remote UE through the second connection, and transmit the first message through the first connection, and the L2 ID of the remote UE can be mapped to the second connection where the first message was received.

[0029] A method by a second relay UE (User Equipment) according to another aspect comprises the steps of: establishing a first connection with a base station and a second connection with a first relay UE for U2N relay (UE to Network); receiving a first message including an L2 ID (layer 2 identifier) ​​of a first remote UE through the second connection; and transmitting a third message to the base station through the first connection to convey the first message, wherein the second relay UE can map the L2 ID of the first remote UE to the second connection where the first message was received.

[0030] According to another aspect, a second relay UE (User Equipment) comprises an RF (Radio Frequency) transceiver; and a processor connected to the RF transceiver, wherein the processor controls the RF transceiver to establish a first connection with a base station and a second connection with the first relay UE for U2N relay (UE to Network), receives a first message including an L2 ID (layer 2 identifier) ​​of the first remote UE through the second connection, transmits a third message to the base station through the first connection to deliver the first message, and the L2 ID of the first remote UE may be mapped to the second connection where the first message was received.

[0031] According to one embodiment, multi-hop based U2N relay communication can be performed more accurately and efficiently in a wireless communication system. For example, by mapping the connection to which a message from a remote UE is received with the L2 ID included in the message, the connection to which a message to the remote UE is to be delivered can be accurately identified even before the configuration of the gNB associated with the U2N relay is completed.

[0032] The effects obtainable from various embodiments are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description below.

[0033] The drawings attached to this specification are intended to provide an understanding of the present invention, to illustrate various embodiments of the invention, and to explain the principles of the invention together with the description in the specification.

[0034] Figure 1 is a diagram illustrating a comparison between V2X communication based on RAT prior to NR and V2X communication based on NR.

[0035] Figure 2 shows the structure of an LTE system.

[0036] Figure 3 shows the structure of the NR system.

[0037] Figure 4 shows the structure of a wireless frame of NR.

[0038] Figure 5 shows the slot structure of an NR frame.

[0039] FIG. 6 shows a communication structure that can be provided in a 6G system according to one embodiment of the present disclosure.

[0040] FIG. 7 shows an electromagnetic spectrum according to one embodiment of the present disclosure.

[0041] Figure 8 shows the radio protocol architecture for SL communication.

[0042] Figure 9 shows a terminal performing V2X or SL communication.

[0043] Figure 10 shows a resource unit for V2X or SL communication.

[0044] FIG. 11 shows an example of a BWP according to one embodiment of the present disclosure.

[0045] FIG. 12 illustrates a procedure in which a terminal performs V2X or SL communication according to a resource allocation mode, according to one embodiment of the present disclosure.

[0046] Figure 13 is a diagram illustrating the control plane procedure of an L2 U2N relay (UE-to-Network Relay).

[0047] FIG. 14 is a diagram illustrating the SRAP sublayer operation on the relay UE or remote UE side.

[0048] Figure 15 is a diagram schematically illustrating the functions of the SRAP sublayer in the PC5 interface and the Uu interface.

[0049] FIG. 16 is a diagram illustrating multi-hop based U2N relay operation, and FIG. 17 is a diagram illustrating SRAP header structure.

[0050] FIG. 18 is a diagram illustrating how a first relay UE performs a multi-hop based U2N relay.

[0051] FIG. 19 is a diagram illustrating how a second relay UE performs a multi-hop based U2N relay.

[0052] FIG. 20 illustrates a communication system to which the present invention is applied.

[0053] FIG. 21 illustrates a wireless device that can be applied to the present invention.

[0054] FIG. 22 illustrates another example of a wireless device to which the present invention applies. The wireless device may be implemented in various forms depending on the use-example / service.

[0055] FIG. 23 illustrates a vehicle or autonomous vehicle to which the present invention is applied.

[0056] 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.

[0057] Sidelink 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). Sidelink is being considered as a solution to address the burden on base stations caused by rapidly increasing data traffic.

[0058] 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.

[0059] 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 MTC, and URLLC (Ultra-Reliable and Low Latency Communication) 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.

[0060] 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.

[0061] 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.

[0062] For clarity of explanation, the description focuses on LTE-A or 5G NR, but the technical concept of the embodiment(s) is not limited thereto.

[0063] Figure 2 shows the structure of an applicable LTE system. This can be called an E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network), or an LTE (Long Term Evolution) / LTE-A system.

[0064] Referring to FIG. 2, the E-UTRAN includes a base station (20; Base Station, BS) 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.

[0065] 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.

[0066] 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 as its endpoint.

[0067] 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.

[0068] Figure 3 shows the structure of the NR system.

[0069] Referring to FIG. 3, the NG-RAN may include gNBs and / or eNBs that provide user plane and control plane protocol termination to terminals. FIG. 7 illustrates a case where only gNBs are included. The gNBs and eNBs are connected to each other via Xn interfaces. The gNBs and eNBs are connected to the 5G Core Network (5GC) via NG interfaces. More specifically, they are connected to the access and mobility management function (AMF) via NG-C interfaces and to the user plane function (UPF) via NG-U interfaces.

[0070] Figure 4 shows the structure of a wireless frame of NR.

[0071] Referring to FIG. 4, 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).

[0072] 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 (Single Carrier - FDMA) symbols (or DFT-s-OFDM (Discrete Fourier Transform-spread-OFDM) symbols).

[0073] Table 1 below shows the number of symbols per slot ((N) according to the SCS setting (u) when normal CP is used. slot symb ), number of slots per frame((N frame,u slot ) and the number of slots per subframe((N subframe,u slot ) exemplifies.

[0074] SCS (15*2 u )N slot symb N frame,u slot N subframe,u slot 15KHz (u=0)1410130KHz (u=1)1420260KHz (u=2)14404120KHz (u=3)14808240KHz (u=4)1416016

[0075] 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.

[0076] SCS (15*2 u )N slot symb N frame,u slot N subframe,u slot 60KHz (u=2)12404

[0077] 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.

[0078] 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.

[0079] 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 "sub 6GHz range" and FR2 may mean "above 6GHz range" and may be referred to as millimeter wave (mmW).

[0080] Frequency Range designationCorresponding frequency rangeSubcarrier Spacing (SCS)FR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0081] 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).

[0082] Frequency Range designationCorresponding frequency rangeSubcarrier Spacing (SCS)FR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0083] Figure 5 shows the slot structure of an NR frame.

[0084] Referring to FIG. 5, 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.

[0085] 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.

[0086] 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.

[0087] FIG. 6 illustrates a communication structure that can be provided in a 6G system according to one embodiment of the present disclosure. The embodiment of FIG. 6 can be combined with various embodiments of the present disclosure.

[0088] New network characteristics in 6G may be as follows.

[0089] - Satellite Integrated Network

[0090] - Connected Intelligence: Unlike previous generations of wireless communication systems, 6G is innovative and will update wireless evolution from "connected things" to "connected intelligence." AI can be applied at each stage of the communication process (or at each step of the signal processing described below).

[0091] - Seamless integration of wireless information and energy transfer

[0092] - Ubiquitous Super 3D Connectivity: Connectivity to the network and core network functions of drones and very low Earth orbit satellites will create Super 3D connectivity in 6G ubiquitous.

[0093] Some general requirements regarding the new network characteristics of 6G mentioned above may be as follows.

[0094] - Small cell networks

[0095] - Ultra-dense heterogeneous network

[0096] - High-capacity backhaul

[0097] - Radar technology integrated with mobile technology: High-precision localization (or location-based services) through communication is one of the functions of 6G wireless communication systems. Therefore, radar systems will be integrated with 6G networks.

[0098] - Softwarization and virtualization

[0099] The core implementation technologies of the 6G system are described below.

[0100] - Artificial Intelligence: Introducing AI into communications can streamline and enhance real-time data transmission. AI can determine how complex target tasks are performed using numerous analyses. In other words, AI can increase efficiency and reduce processing latency. Time-consuming tasks such as handover, network selection, and resource scheduling can be performed instantly using AI. AI can also play a significant role in M2M, machine-to-human, and human-to-machine communication. Furthermore, AI can enable rapid communication in Brain-Computer Interfaces (BCI). AI-based communication systems can be supported by metamaterials, intelligent structures, intelligent networks, intelligent devices, intelligent cognitive radios, self-sustaining wireless networks, and machine learning.

[0101] - THz Communication: Data transmission rates can be increased by expanding bandwidth. This can be achieved by using sub-THz communication with wide bandwidth and applying advanced large-scale MIMO technology. THz waves, also known as sub-millimeter radiation, generally refer to a frequency band between 0.1 THz and 10 THz with corresponding wavelengths ranging from 0.03 mm to 3 mm. The 100 GHz-300 GHz band range (Sub-THz band) is considered the primary portion of the THz band for cellular communication. Adding the Sub-THz band to the mmWave band increases 6G cellular communication capacity. Among the defined THz bands, the 300 GHz-3 THz band is located in the far-infrared (IR) frequency band. Although the 300 GHz-3 THz band is part of the optical band, it lies at the boundary of the optical band and immediately following the RF band. Therefore, this 300 GHz-3 THz band exhibits similarities to RF.

[0102] FIG. 7 illustrates an electromagnetic spectrum according to one embodiment of the present disclosure. The embodiment of FIG. 7 may be combined with various embodiments of the present disclosure. Key characteristics of THz communication include (i) a widely available bandwidth to support very high data transmission rates, and (ii) high path loss occurring at high frequencies (highly directional antennas are indispensable). The narrow beam width generated by highly directional antennas reduces interference. The small wavelength of THz signals allows a much larger number of antenna elements to be integrated into devices and BSs operating in this band. This enables the use of advanced adaptive array techniques that can overcome range limitations.

[0103] - Large-scale MIMO technology

[0104] - Hologram beamforming (HBF)

[0105] - Optical wireless technology

[0106] - Free Space Optical Transmission Backhaul Network (FSO backhaul network)

[0107] - Quantum communication

[0108] - Cell-free communication

[0109] - Integration of wireless information and power transmission

[0110] - Integration of wireless communication and sensing

[0111] - Integrated access and backhaul network

[0112] - Big data analysis

[0113] - Reconfigurable intelligent metasurface

[0114] - Metaverse

[0115] - blockchain

[0116] - Unmanned Aerial Vehicle (UAV): UAVs or drones will be a critical element in 6G wireless communication. In most cases, high-speed data wireless connectivity can be provided using UAV technology. Base station (BS) entities can be installed on UAVs to provide cellular connectivity. UAVs can possess specific features not found in fixed BS infrastructure, such as easy deployment, robust line-of-sight links, and controlled degrees of freedom for mobility. During emergencies, such as natural disasters, the deployment of ground communication infrastructure is not economically feasible, and sometimes services cannot be provided in volatile environments. UAVs can easily handle these situations. UAVs will become a new paradigm in the field of wireless communication. This technology facilitates the three fundamental requirements of wireless networks: eMBB, URLLC, and mMTC. UAVs can also support various purposes, such as enhancing network connectivity, fire detection, disaster emergency services, security and surveillance, pollution monitoring, parking monitoring, and accident monitoring. Therefore, UAV technology is recognized as one of the most critical technologies for 6G communication.

[0117] - Autonomous Driving (Self-Driving): V2X (Vehicle to Everything), a core element in building autonomous driving infrastructure, refers to technologies that enable vehicles to communicate and share with various elements on the road for autonomous driving, such as wireless communication between vehicles (Vehicle to Vehicle, V2V) and between vehicles and infrastructure (Vehicle to Infrastructure, V2I). Fast transmission speeds and low-latency technologies are essential to maximize autonomous driving performance and ensure high safety. Furthermore, future autonomous driving may go beyond simply delivering warning or guidance messages to the driver to actively intervene in vehicle operation and directly control the vehicle in dangerous situations. Since the amount of information to be transmitted and received may become massive for this purpose, it is expected that 6G will be able to maximize autonomous driving through faster transmission speeds and lower latency compared to 5G.

[0118] FIG. 8 illustrates a radio protocol architecture for SL communication. Specifically, FIG. 8 (a) shows the user plane protocol stack of NR, and FIG. 8 (b) shows the control plane protocol stack of NR.

[0119] The Sidelink Synchronization Signal (SLSS) and synchronization information are described below.

[0120] SLSS is an SL-specific sequence that may include PSSS (Primary Sidelink Synchronization Signal) and SSSS (Secondary Sidelink Synchronization Signal). The PSSS may be referred to as S-PSS (Sidelink Primary Synchronization Signal), and the SSSS may be referred to as S-SSS (Sidelink Secondary Synchronization Signal). For example, length-127 M-sequences may be used for S-PSS, and length-127 Gold sequences may be used for S-SSS. For example, a terminal may use S-PSS to detect a primary signal and obtain synchronization. For example, a terminal may use S-PSS and S-SSSS to obtain detailed synchronization and detect a synchronization signal ID.

[0121] PSBCH (Physical Sidelink Broadcast Channel) may be a (broadcast) channel through which basic (system) information that a terminal must know first is transmitted before transmitting or receiving SL signals. For example, the basic information may include information related to SLSS, Duplex Mode (DM), TDD UL / DL (Time Division Duplex Uplink / Downlink) configuration, information related to resource pools, types of applications related to SLSS, subframe offsets, broadcast information, etc. For example, to evaluate PSBCH performance, in NR V2X, the payload size of PSBCH may be 56 bits, including a 24-bit CRC.

[0122] S-PSS, S-SSS, and PSBCH may be included in a block format that supports periodic transmission (e.g., SL SS (Synchronization Signal) / PSBCH block, hereinafter S-SSB (Sidelink-Synchronization Signal Block)). The S-SSB may have the same numerology (i.e., SCS and CP lengths) as the PSCCH (Physical Sidelink Control Channel) / PSSCH (Physical Sidelink Shared Channel) within the carrier, and the transmission bandwidth may be within a (pre-)set SL BWP (Sidelink BWP). For example, the bandwidth of the S-SSB may be 11 RB (Resource Block). For example, the PSBCH may span 11 RB. Additionally, the frequency position of the S-SSB may be (pre-)set. Therefore, the terminal does not need to perform hypothesis detection at the frequency to discover the S-SSB in the carrier.

[0123] Meanwhile, in an NR SL system, multiple numerologies having different SCS and / or CP lengths may be supported. In this case, as the SCS increases, the length of the time resource for the transmitting terminal to transmit S-SSBs may decrease. Consequently, the coverage of S-SSBs may decrease. Therefore, to ensure S-SSB coverage, the transmitting terminal may transmit one or more S-SSBs to the receiving terminal within a single S-SSB transmission cycle according to the SCS. For example, the number of S-SSBs transmitted by the transmitting terminal to the receiving terminal within a single S-SSB transmission cycle may be pre-configured or configured for the transmitting terminal. For example, the S-SSB transmission cycle may be 160ms. For example, an S-SSB transmission cycle of 160ms may be supported for all SCSs.

[0124] For example, if the SCS is 15 kHz at FR1, the transmitting terminal may transmit one or two S-SSBs to the receiving terminal within one S-SSB transmission cycle. For example, if the SCS is 30 kHz at FR1, the transmitting terminal may transmit one or two S-SSBs to the receiving terminal within one S-SSB transmission cycle. For example, if the SCS is 60 kHz at FR1, the transmitting terminal may transmit one, two, or four S-SSBs to the receiving terminal within one S-SSB transmission cycle.

[0125] For example, if the SCS is 60 kHz at FR2, the transmitting terminal can transmit 1, 2, 4, 8, 16, or 32 S-SSBs to the receiving terminal within one S-SSB transmission cycle. For example, if the SCS is 120 kHz at FR2, the transmitting terminal can transmit 1, 2, 4, 8, 16, 32, or 64 S-SSBs to the receiving terminal within one S-SSB transmission cycle.

[0126] Meanwhile, when the SCS is 60 kHz, two types of CP may be supported. Additionally, depending on the CP type, the structure of the S-SSB transmitted by the transmitting terminal to the receiving terminal may differ. For example, the CP type may be Normal CP (NCP) or Extended CP (ECP). Specifically, for example, if the CP type is NCP, the number of symbols mapping PSBCH within the S-SSB transmitted by the transmitting terminal may be 9 or 8. On the other hand, for example, if the CP type is ECP, the number of symbols mapping PSBCH within the S-SSB transmitted by the transmitting terminal may be 7 or 6. For example, PSBCH may be mapped to the first symbol within the S-SSB transmitted by the transmitting terminal. For example, the receiving terminal receiving the S-SSB may perform Automatic Gain Control (AGC) operation during the first symbol interval of the S-SSB.

[0127] Figure 9 shows a terminal performing V2X or SL communication.

[0128] Referring to FIG. 9, in V2X or SL communication, the term terminal may primarily refer to a user's terminal. However, if network equipment such as a base station transmits and receives signals according to the communication method between terminals, the base station may also be considered a type of terminal. For example, terminal 1 may be a first device (100), and terminal 2 may be a second device (200).

[0129] For example, terminal 1 can select a resource unit corresponding to a specific resource within a resource pool, which represents a set of resources. Then, terminal 1 can transmit an SL signal using the said resource unit. For example, terminal 2, which is a receiving terminal, can be configured with a resource pool in which terminal 1 can transmit a signal, and can detect terminal 1's signal within said resource pool.

[0130] Here, if terminal 1 is within the connection range of the base station, the base station may inform terminal 1 of the resource pool. On the other hand, if terminal 1 is outside the connection range of the base station, another terminal may inform terminal 1 of the resource pool, or terminal 1 may use a pre-configured resource pool.

[0131] Generally, a resource pool can be composed of multiple resource units, and each terminal can select one or more resource units to use for its SL signal transmission.

[0132] Figure 10 shows a resource unit for V2X or SL communication.

[0133] Referring to FIG. 10, the total frequency resources of the resource pool can be divided into NF units, and the total time resources of the resource pool can be divided into NT units. Thus, a total of NF * NT resource units can be defined within the resource pool. FIG. 10 illustrates an example where the resource pool is repeated in a period of NT subframes.

[0134] As shown in FIG. 10, a single resource unit (e.g., Unit #0) may appear repeatedly over time. Alternatively, to obtain diversity effects in the time or frequency dimension, the index of the physical resource unit to which a single logical resource unit is mapped may change in a predetermined pattern over time. In this structure of resource units, a resource pool may refer to a set of resource units that a terminal intending to transmit an SL signal can use for transmission.

[0135] Resource pools can be subdivided into several types. For example, depending on the content of the SL signals transmitted from each resource pool, resource pools can be classified as follows.

[0136] (1) A Scheduling Assignment (SA) may be a signal containing information such as the location of the resource used by the transmitting terminal for transmission of the SL data channel, the Modulation and Coding Scheme (MCS) or Multiple Input Multiple Output (MIMO) transmission method required for demodulation of the data channel, and Timing Advance (TA). The SA may also be multiplexed and transmitted together with the SL data on the same resource unit, in which case the SA resource pool may refer to a resource pool in which the SA is multiplexed and transmitted together with the SL data. The SA may also be called the SL control channel.

[0137] (2) A Physical Sidelink Shared Channel (PSSCH) may be a resource pool used by a transmitting terminal to transmit user data. If SA is multiplexed and transmitted along with SL data on the same resource unit, only the form of the SL data channel excluding SA information can be transmitted from the resource pool for the SL data channel. In other words, REs (Resource Elements) that were used to transmit SA information on individual resource units within the SA resource pool can still be used to transmit SL data in the resource pool of the SL data channel. For example, the transmitting terminal can transmit by mapping the PSSCH to a succession of PRBs.

[0138] (3) The discovery channel may be a resource pool for a transmitting terminal to transmit information such as its ID. Through this, the transmitting terminal can enable adjacent terminals to discover it.

[0139] Even if the content of the SL signal described above is the same, different resource pools may be used depending on the transmission and reception attributes of the SL signal. For example, even if the same SL data channel or discovery message is used, it may be divided into different resource pools depending on the method of determining the transmission timing of the SL signal (e.g., whether it is transmitted at the time of reception of the synchronization reference signal or whether it is transmitted by applying a certain timing advance at the time of reception), the method of resource allocation (e.g., whether the base station assigns the transmission resource of an individual signal to the individual transmission terminal or whether the individual transmission terminal selects the individual signal transmission resource itself from within the resource pool), the signal format (e.g., the number of symbols occupied by each SL signal in one subframe, or the number of subframes used for the transmission of one SL signal), the signal strength from the base station, the transmission power strength of the SL terminal, etc.

[0140] FIG. 11 illustrates an example of a BWP according to an embodiment of the present disclosure. The embodiment of FIG. 11 may be combined with various embodiments of the present disclosure. In the embodiment of FIG. 11, it is assumed that there are three BWPs.

[0141] Referring to FIG. 11, the common resource block (CRB) may be a numbered carrier resource block extending from one end of the carrier band to the other. And, the PRB may be a numbered resource block within each BWP. Point A may indicate a common reference point for the resource block grid.

[0142] A BWP can be configured by point A, an offset from point A (NstartBWP), and a bandwidth (NsizeBWP). For example, point A may be an external reference point of the PRB of a carrier where the subcarrier 0 of all numerologies (e.g., all numerologies supported by the network on that carrier) is aligned. For example, the offset may be the PRB interval between the lowest subcarrier in a given numerology and point A. For example, the bandwidth may be the number of PRBs in a given numerology.

[0143] SLSS (Sidelink Synchronization Signal) is a sidelink-specific sequence and may include PSSS (Primary Sidelink Synchronization Signal) and SSSS (Secondary Sidelink Synchronization Signal). The PSSS may be referred to as S-PSS (Sidelink Primary Synchronization Signal), and the SSSS may be referred to as S-SSS (Sidelink Secondary Synchronization Signal). For example, length-127 M-sequences may be used for S-PSS, and length-127 Gold sequences may be used for S-SSS. For example, a terminal may use S-PSS to detect the initial signal and obtain synchronization. For example, a terminal may use S-PSS and S-SSSS to obtain detailed synchronization and detect the synchronization signal ID.

[0144] The PSBCH (Physical Sidelink Broadcast Channel) may be a (broadcast) channel through which basic (system) information that the terminal must know first is transmitted before transmitting or receiving SL signals. For example, the basic information may include information related to SLSS, Duplex Mode (DM), TDD UL / DL (Time Division Duplex Uplink / Downlink) configuration, information related to resource pools, types of applications related to SLSS, subframe offsets, broadcast information, etc. For example, to evaluate PSBCH performance, in NR V2X, the payload size of the PSBCH may be 56 bits, including a 24-bit CRC (Cyclic Redundancy Check).

[0145] S-PSS, S-SSS, and PSBCH may be included in a block format that supports periodic transmission (e.g., SL SS (Synchronization Signal) / PSBCH block, hereinafter S-SSB (Sidelink-Synchronization Signal Block)). The S-SSB may have the same numerology (i.e., SCS and CP lengths) as the PSCCH (Physical Sidelink Control Channel) / PSSCH (Physical Sidelink Shared Channel) within the carrier, and the transmission bandwidth may be within a (pre-)set SL BWP (Sidelink BWP). For example, the bandwidth of the S-SSB may be 11 RB (Resource Block). For example, the PSBCH may span 11 RB. Additionally, the frequency position of the S-SSB may be (pre-)set. Therefore, the terminal does not need to perform hypothesis detection at the frequency to discover the S-SSB in the carrier.

[0146] FIG. 12 illustrates a procedure in which a terminal performs V2X or SL communication according to a resource allocation mode, according to one embodiment of the present disclosure. The embodiment of FIG. 12 may be combined with various embodiments of the present disclosure.

[0147] Referring to FIG. 12(a), in resource allocation mode 1, the base station may schedule SL resources to be used by the terminal for SL transmission. For example, in step S1200, the base station may transmit information related to SL resources and / or information related to UL resources to the first terminal. For example, the UL resources may include PUCCH resources and / or PUSCH resources. For example, the UL resources may be resources for reporting SL HARQ feedback to the base station.

[0148] For example, the first terminal may receive information related to a dynamic grant (DG) resource and / or information related to a configured grant (CG) resource from the base station. For example, the CG resource may include a CG type 1 resource or a CG type 2 resource. In this specification, the DG resource may be a resource that the base station sets / assigns to the first terminal via downlink control information (DCI). In this specification, the CG resource may be a (periodic) resource that the base station sets / assigns to the first terminal via DCI and / or RRC messages. For example, in the case of a CG type 1 resource, the base station may transmit an RRC message containing information related to the CG resource to the first terminal. For example, in the case of a CG type 2 resource, the base station may transmit an RRC message containing information related to the CG resource to the first terminal, and the base station may transmit DCI related to the activation or release of the CG resource to the first terminal.

[0149] In step S1210, the first terminal may transmit a PSCCH (e.g., Sidelink Control Information or 1st-stage SCI) to the second terminal based on the resource scheduling. In step S1220, the first terminal may transmit a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) associated with the PSCCH to the second terminal. In step S1230, the first terminal may receive a PSFCH associated with the PSCCH / PSSCH from the second terminal. For example, HARQ feedback information (e.g., NACK information or ACK information) may be received from the second terminal via the PSFCH. In step S1240, the first terminal may transmit / report the HARQ feedback information to the base station via a PUCCH or PUSCH. For example, the HARQ feedback information reported to the base station may be information generated by the first terminal based on HARQ feedback information received from the second terminal. For example, the HARQ feedback information reported to the base station may be information generated by the first terminal based on a pre-set rule. For example, the DCI may be a DCI for scheduling SL.

[0150] Referring to FIG. 12(b), in 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. For example, in step S1210, the first terminal, having selected a resource itself within the resource pool, may use the resource to transmit PSCCH (e.g., SCI (Sidelink Control Information) or 1st-stage SCI) to the second terminal. In step S1220, the first terminal can transmit PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) associated with the PSCCH to the second terminal. In step S1230, the first terminal can receive PSFCH associated with the PSCCH / PSSCH from the second terminal.

[0151] Referring to FIG. 12 (a) or (b), for example, the first terminal may transmit an SCI to the second terminal over the PSCCH. Or, for example, the first terminal may transmit two consecutive SCIs (e.g., 2-stage SCIs) to the second terminal over the PSCCH and / or PSSCH. In this case, the second terminal may decode the two consecutive SCIs (e.g., 2-stage SCIs) to receive the PSSCH from the first terminal. In this specification, an SCI transmitted over the PSCCH may be referred to as the 1st SCI, the 1st SCI, the 1st-stage SCI, or the 1st-stage SCI format, and an SCI transmitted over the PSSCH may be referred to as the 2nd SCI, the 2nd SCI, the 2nd-stage SCI, or the 2nd-stage SCI format.

[0152] Referring to FIG. 12 (a) or (b), in step S1230, the first terminal can receive PSFCH. For example, the first terminal and the second terminal can determine a PSFCH resource, and the second terminal can use the PSFCH resource to transmit HARQ feedback to the first terminal.

[0153] Referring to FIG. 12(a), in step S1240, the first terminal can transmit SL HARQ feedback to the base station via PUCCH and / or PUSCH.

[0154] Meanwhile, the aforementioned sidelink may be defined as communication between terminals or direct communication between terminals. In this case, PSCCH may be defined as a physical control channel for direct communication between terminals, PSSCH as a physical data channel or physical sharing channel for direct communication between terminals, and PSFCH as a physical feedback transmission channel for direct communication between terminals.

[0155] Figure 13 is a diagram illustrating the control plane procedure of an L2 U2N relay (UE-to-Network Relay).

[0156] The PC5-RRC side PC5 unicast link setup procedure of Rel-16 NR V2X can be reused to set up a secure unicast link for layer 2 UE-to-Network relaying between the remote UE and the relay UE before the remote UE establishes a Uu RRC connection with the network through the relay UE.

[0157] For both in-coverage and out-of-coverage situations, when the remote UE initiates the first RRC message to establish a connection with the gNB, the PC5 L2 configuration for transmission between the remote UE and the U2N relay UE can be based on the RLC / MAC configuration defined in the standard. The establishment of the remote UE's Uu SRB1 / SRB2 and DRB follows the legacy Uu configuration procedure for the L2 U2N relay.

[0158] A specified scenario (TS 38.300) describes the control plane procedure of the L2 U2N relay as follows.

[0159] In step S1300, the remote UE and the relay UE perform a discovery procedure and can establish a PC5-RRC connection in step S1301 based on the existing Rel-16 procedure.

[0160] In step S1302, the remote UE can send the first RRC message (i.e., RRCSetupRequest) to establish a connection with the gNB via the Relay UE using the default L2 configuration of PC5. The gNB responds to the remote UE with an RRCSetup message (S1303). The delivery of the RRCSetup to the remote UE uses the default configuration of PC5. If the relay UE was not started in RRC_CONNECTED, it must perform its own connection setup upon receiving the message for the default L2 configuration of PC5.

[0161] In step S1304, the gNB and the relay UE perform the relay channel setup procedure via Uu. Depending on the configuration of the gNB, the relay / remote UE establishes an RLC channel to relay SRB1 to the remote UE via PC5. This step prepares the relay channel for SRB1.

[0162] In step S1305, a remote UE SRB1 message (e.g., RRCSetupComplete message) is transmitted to the gNB via the relay UE using the SRB1 relay channel through PC5. Then, the remote UE establishes an RRC connection through Uu.

[0163] In steps S1306 and S1307, the remote UE and gNB establish security according to legacy procedures, and security messages are transmitted through the Relay UE.

[0164] In steps S1308 and S1309, the gNB sends RRCReconfiguration to the remote UE via the relay UE to configure the relay SRB2 / DRB. The remote UE sends RRCReconfigurationComplete to the gNB in ​​response via the relay UE.

[0165] In step S1310, the gNB establishes an additional RLC channel between the gNB and the relay UE for traffic relay. Depending on the configuration of the gNB, the relay / remote UE establishes an additional RLC channel between the remote UE and the relay UE for traffic relay.

[0166] In the above scenario, in addition to the connection setup procedure, for the L2 UE-to-Network relay:

[0167] - The RRC reconfiguration and RRC disconnection procedures can reuse legacy RRC procedures along with the message content / configuration design left in the WI stage.

[0168] The RRC connection reset and resumption procedures can reuse existing RRC procedures as a baseline by considering the connection setup procedure of the L2 U2N relay above to handle specific parts of the relay, along with the message content / configuration design. The message content / configuration may be defined later.

[0169] SRAP (Sidelink Relay Adaptation Protocol)

[0170] Figures 14 and 15 are diagrams for schematically illustrating the functions of the SRAP sublayer in the PC5 interface and Uu interface.

[0171] SRAP may be a protocol layer designed to support sidelink relay communication in NR (New Radio) systems. This protocol can be situated above the RLC (Radio Link Control) sublayer, which is above the MAC (Media Access Control) and PHY (Physical Layer) layers in a wireless interface protocol architecture. SRAP applies to both the User Plane (UP) and the Control Plane (CP), and can operate on both the PC5 interface (sidelink) and the Uu interface (cellular). Key functions of SRAP include data transmission, determination of UE ID and BEARER ID fields within data packets, determination of the egress (transmit) link, and determination of the egress RLC channel.

[0172] SRAP can play a significant role, particularly in L2 UE-to-Network (U2N) relay scenarios. In these scenarios, the SRAP sublayer of the relay UE can forward data received from the remote UE via the PC5 interface to the gNB via the Uu interface, or vice versa. In this process, SRAP performs bearer mapping and may include a UE ID identifying the remote UE and a BEARER ID identifying the bearer in the data packet. For example, during downlink, the gNB can include the end-to-end Uu radio bearer information of the L2 U2N remote UE and the local remote UE ID in the Uu SRAP header to enable the relay UE to identify them. The remote UE can associate the received packet with the correct PDCP entity based on the identifier information included in the PC5 SRAP header. For specific bearers, such as SRB0 (Signaling Radio Bearer 0), the system may operate by transmitting data without an SRAP header or by adding or removing the SRAP header internally within the relay UE.

[0173] Referring to FIG. 14, the SRAP sublayer operation on the relay UE or remote UE side is illustrated.

[0174] For general data packets (excluding SRB0), the transmitting part may receive SRAP data packets from the relay UE SRAP entity receiver on the Uu interface (in the case of a relay UE) or from the upper layer (in the case of a remote UE). An SRAP header is added to the received data packet, and this header may include determined UE ID and BEARER ID fields. These fields may be used to identify the destination of the data packet and the corresponding bearer. Subsequently, the data may be mapped to the appropriate egress PC5 relay RLC channel and transmitted to the lower layer. For uplink transmission of SRB0 data packets, the SRAP entity transmitter on the PC5 interface (L2 U2N remote UE) receives an SRAP SDU from the upper layer but may construct and transmit a data PDU without an SRAP header.

[0175] The receiving part can receive an SRAP data PDU from the lower layer (PC5-RLC). In the case of a general data packet other than an SRB0, the receiving part can remove the SRAP header and forward the SRAP Service Data Unit (SDU) to the relay UE SRAP entity transmitter of the Uu interface (in the case of a relay UE) or to the upper layer (in the case of a remote UE). In this case, the received packet can be associated with the correct upper layer entity by utilizing the UE ID and BEARER ID information included in the SRAP header. In the case of receiving an SRB0 data packet downlink, the SRAP entity receiver of the PC5 interface (L2 U2N relay UE) can receive the SRAP data PDU from the SRAP entity receiver of the Uu interface, remove the SRAP header, and forward the SRAP SDU to the upper layer.

[0176] Referring to FIG. 15, the SRAP sublayer operation on the NB or relay UE side is illustrated.

[0177] For general data packets (excluding SRB0), the transmitting part may receive SRAP data packets from the relay UE SRAP entity receiver on the PC5 interface (in the case of a relay UE) or from an upper layer (in the case of a gNB). The transmitting part constructs an SRAP data PDU, and in doing so, may determine the UE ID and BEARER ID fields by including an SRAP header. For example, in the case of uplink relay traffic, the relay UE may include the identification information of the remote UE and the bearer ID so that the gNB can properly process the packet. The constructed SRAP data PDU can be mapped to the appropriate egress Uu relay RLC channel and transmitted to the lower layer. In the case of uplink SRB0 data packets, the transmitting part receives an SRAP SDU from the SRAP entity receiver on the PC5 interface, and may construct an SRAP data PDU by adding an SRAP header. The UE ID field corresponds to sl-LocalIdentity, and the BEARER ID field can be set to '0'.

[0178] The receiving part can receive an SRAP data PDU from the lower layer (Uu-RLC). For general data packets that are not SRB0, the receiving part can forward the SRAP data PDU as is to the SRAP entity transmitter on the PC5 interface (in the case of a relay UE) or to the upper layer (in the case of a gNB). For downlink SRB0 data packets, the SRAP entity receiving part on the Uu interface (L2 U2N relay UE) can receive the SRAP data PDU and then forward it to the SRAP entity transmitter on the PC5 interface. This transmitter can then remove the SRAP header.

[0179] (1) The transmission operation of the U2N relay UE may be as follows.

[0180] The transmitter of an SRAP entity located at the Uu interface of a U2N relay UE receives an SRAP data packet from the receiver of an SRAP entity located at the PC5 interface of the same U2N relay UE, and can construct an SRAP data PDU as needed.

[0181] If the transmitter of an SRAP entity located on the Uu interface holds an SRAP data PDU to transmit, the transmitter of the SRAP entity located on the Uu interface must perform the following:

[0182] - If the SRAP data PDU is received from SL-RLC0 as defined in TS 38.331: Determine the UE ID field and the BEARER ID field. Construct the SRAP data PDU with an SRAP header containing the UE ID field and the BEARER ID field set to the determined values.

[0183] Determine the transmission RLC channel.

[0184] Submit the corresponding SRAP data PDU to the determined transmission RLC channel.

[0185] (2) Determination of UE ID field and BEARER ID field

[0186] For an SRAP data PDU received from SL-RLC0, the SRAP entity must perform the following:

[0187] - If sl-L2IdentityRemote matching the Layer 2 ID of the remote UE in the received SRAP data PDU is included in sl-RemoteUE-ToAddModList: Determine the UE ID field corresponding to the sl-LocalIdentity configured for the sl-L2IdentityRemote. Determine the BEARER ID field as 0 (e.g., set the BEARER ID field to 0).

[0188] Such a SARP can be configured via SL-SRAP-Config as shown in Table 5. SL-SRAP-Config can be configured for the UE via SL-L2RelayUE-Config of the RCReconfiguration message.

[0189] ASN1START-- TAG-SL-SRAP-CONFIG-STARTSL-SRAP-Config-r17 ::= SEQUENCE {sl-LocalIdentity-r17 INTEGER (0..255) OPTIONAL, -- Need Msl-MappingToAddModList-r17 SEQUENCE (SIZE (1..maxLC-ID)) OF SL-MappingToAddMod-r17 OPTIONAL, -- Need Nsl-MappingToReleaseList-r17 SEQUENCE (SIZE (1..maxLC-ID)) OF SL-RemoteUE-RB-Identity-r17 OPTIONAL, -- Need N...}SL-MappingToAddMod-r17 ::= SEQUENCE {sl-RemoteUE-RB-Identity-r17 SL-RemoteUE-RB-Identity-r17,sl-EgressRLC-ChannelUu-r17 Uu-RelayRLC-ChannelID-r17 OPTIONAL, -- Cond L2RelayUEsl-EgressRLC-ChannelPC5-r17 SL-RLC-ChannelID-r17 OPTIONAL, -- Need N...}SL-RemoteUE-RB-Identity-r17 ::= CHOICE {srb-Identity-r17 INTEGER (0..3),drb-Identity-r17 DRB-Identity,...}-- TAG-SL-SRAP-CONFIG-STOP-- ASN1STOP

[0190] Here, sl-LocalIdentity indicates the local UE ID of the L2 U2N remote UE used in SRAP, sl-MappingToAddModList indicates a list of items to be added or modified in the mapping between the L2 U2N remote UE bearer ID and the egress RLC channel as defined in TS 38.351, sl-MappingToReleaseList indicates a list of items to be released in the mapping between the L2 U2N remote UE bearer ID and the egress RLC channel as defined in TS 38.351, and sl-RemoteUE-RB-Identity indicates the end-to-end Uu bearer ID of the L2 U2N remote UE (the value 3 of the srb-identity-r17 field (for SRB3 configuration purposes) may not be supported). Additionally, sl-EgressRLC-ChannelUu indicates an egress RLC channel on the Uu hop for upstream transmission from the L2 U2N relay UE, and sl-EgressRLC-ChannelPC5 may indicate an egress RLC channel on the PC5 hop for downstream transmission from the L2 U2N relay UE and upstream transmission from the L2 U2N remote UE.

[0191] Local ID assignment for multi-hop U2N relay operation

[0192] FIG. 16 is a diagram illustrating multi-hop based U2N relay operation, and FIG. 17 is a diagram illustrating SRAP header structure.

[0193] Referring to Fig. 16, the multi-hop U2N relay operation may be handled by the rel-19 SL relay. The multi-hop U2N relay operation may be a structure in which data transmission and reception from the gNB to the remote UE through multiple hops is performed in the existing U2N operation.

[0194] In the operation of the existing Rel-17 U2N relay, the gNB establishes an ingress RLC (Radio Link Control) channel and an egress RLC channel for one e2e (end-to-end) bearer ID to the relay UE. As illustrated in FIG. 17, the SRAP header may include a bearer ID, UE ID, data, etc. (see TS 38.351). Here, the bearer ID is an e2e bearer (end-to-end bearer) ID between the gNB and the remote UE, and the UE ID may include a local ID.

[0195] For example, when a relay UE receives an SRAP data PDU (Protocol Data Unit) with an SRAP header attached, it can determine which remote UE the SRAP data PDU (or data PDU) should be delivered to by using the UE ID included in the SRAP header. Additionally, the relay UE may have an ingress RLC channel ID / logical channel ID and an egress RLC channel ID set for the bearer ID via dedicated RRC. In this case, the relay UE can recognize / know which RLC channel ID / logical channel ID to use to transmit the SRAP data PDU to the remote UE based on the bearer ID. Here, one of the ingress RLC channel ID and the egress RLC channel ID set via dedicated RRC may be a value set for the Uu link, and the other may be a value set for the sidelink (SL). Therefore, a relay UE can forward data PDUs received via the configured Uu link RLC channel for a specific bearer ID through the configured SL RLC channel, and conversely, forward data PDUs received via the configured SL RLC channel through the configured Uu RLC channel. For example, from the perspective of the relay UE, the direction in which to transmit the received data PDU may not be an issue. However, in multi-hop U2N relay operation, intermediate relay UEs may be connected via SL link-SL link (or SL-SL). In this case, it may not be clear to the intermediate relay UE which RLC egress channel to transmit data received via the configured RLC ingress channel to, and which L2 ID to use for transmission.

[0196] Considering these issues, the following describes in detail how an SL-SL relay UE or an intermediate relay UE distinguishes between an ingress RLC channel (or ingress link) and an egress RLC channel (or egress link) using an SRAP header in multi-hop U2N relay operation. Meanwhile, the intermediate relay UE described below may be an SL-SL connection relay UE. The last relay UE may be a Uu-SL connection relay UE that is directly connected to a base station or capable of direct connection. For example, a relay UE used for the connection from the last relay UE to a remote UE will be referred to as an intermediate relay UE.

[0197] Local ID Request and assignment

[0198] Among the intermediate relay UEs, the relay UE having a direct PC5 connection with the remote UE is designated as the first intermediate relay UE, and the relay UE connected to the first intermediate relay UE in the gNB direction is designated as the second intermediate relay UE, and so on. For example, the First / Second / ... relay UEs or the Last relay UE can all be defined as intermediate relay UEs.

[0199] One last relay UE may be connected to multiple intermediate relay UEs, and one intermediate relay UE may be connected to multiple remote UEs. However, for one intermediate relay UE to support U2N, one intermediate relay UE may be limited to having only one PC5-S( / RRC) link established / existing with one intermediate / last relay UE in the direction toward gNB. For example, one first intermediate relay UE may be connected to multiple remote UEs (e.g., SL connection, PC5 connection), but may have only one intermediate relay (e.g., second intermediate relay UE) or one last relay connection (e.g., SL connection, PC5 connection) in the direction toward gNB or gNB.

[0200] A remote UE may transmit a message (e.g., a local ID request message) to request a local ID assignment from the gNB. The local ID request message may include the L2 ID of the remote UE. Here, the L2 ID may be the L2 ID (or (SRC / DST)L2 ID pair) used for the SL connection between the remote UE and the first relay UE. For example, the local ID request message may be transmitted using a newly configured PC5-RRC message. For example, the remote UE may transmit the local ID request message to the base station through the intermediate relay UE using a newly configured PC5-RRC message with the intermediate relay UE.

[0201] In this case, the first intermediate relay UE that receives the Local ID request message can store through which link the Local ID request message was received. For example, the first intermediate relay UE can store / map the association between the link (PC5 or SL link) through which the Local ID request message was received and the L2 ID of the remote UE included in the Local ID request message. The first intermediate relay UE can forward the received Local ID request message to the second intermediate relay UE. For example, if the Local ID request message is received by the first intermediate relay UE before the U2N-related setup between the remote UE and the base station is completed (e.g., before the e2e bearer setup), the first intermediate relay UE can map the L2 ID of the Local ID request message to the SL connection through which the Local ID request message was received. This is because, before the U2N-related setup between the remote UE and the base station is completed (e.g., before the e2e bearer setup, when the relationship between the link / connection and the remote UE has not been established), the link / connection to which the message destined for the remote UE will be delivered must be identified through the aforementioned association.

[0202] Meanwhile, the Access Stratum (AS) layer of the first intermediate relay UE may not know which link among the various links or SL connections corresponds to the SL link of the previous hop leading to the gNB. For example, the AS layer of the first intermediate relay UE may not be able to determine which SL link leading to the base station is among the multiple established SL links (e.g., the SL link with the second intermediate relay, the SL link with the remote UE). Therefore, in multi-hop relay operation, the upper layer of the first intermediate relay UE may inform the AS layer which SL connection / link is the link leading to the gNB. Information indicated in this way can be similarly applied when requesting SIB / paging monitoring (e.g., a message requesting SIB / paging monitoring from the remote UE).

[0203] When the second intermediate relay UE receives a local ID request message containing the L2 ID of a remote UE from the first intermediate relay UE, the second intermediate relay UE can store / map through which SL link the local ID request message was received and through which L2 ID the local ID request message was received via said SL link, as described above. For example, the second intermediate relay UE can check which SL link among the multiple formed / established SL links received the local ID request message and map the SL link through which the local ID request message was received to the L2 ID included in the local ID request message. Subsequently, the second intermediate relay UE can transmit the local ID request message to the last relay UE. Likewise, the upper layer of the second intermediate relay UE can inform the AS layer of the second intermediate relay UE of which SL link among the various SL links held by the second intermediate relay UE is the SL link connected to the last relay UE.

[0204] When the last relay UE receives a local ID request message from the second intermediate relay UE, the last relay UE performs an operation similar to that of the first intermediate relay UE and the second intermediate relay UE described above. For example, the last relay UE stores information regarding which SL link the local ID request message was received through and which remote UE with which L2 ID requested the message through the SL link (e.g., the SL link where the local ID request message was received). For example, the last relay UE checks which SL link among the multiple formed / established SL links received the local ID request message and can map the SL link where the local ID request message was received to the L2 ID included in the local ID request message. Subsequently, the last relay UE can request the gNB to assign a local ID (e.g., the local ID of the remote UE) through a Uu message (e.g., SUI (Sidelink UE information) / UAI (UE assistance information)). In this case, the gNB can assign a local ID to a remote UE that can be paired with the L2 ID (e.g., the L2 ID of the local ID request message). The message that the gNB sends to the last relay UE after assigning the local ID (e.g., a local ID assignment message) may also include information regarding which L2 ID the assigned local ID is assigned to.

[0205] A last relay UE that receives a local ID assignment message from a gNB can specify an SL link corresponding to the L2 ID of a remote UE included in the local ID assignment message based on the L2 ID and related SL information (e.g., association / mapping information between the L2 ID and the SL link) that it stored / mapped before sending a local ID request message to the gNB, and can transmit / forward the local ID assignment message received from the gNB to a second intermediate relay UE through the specified SL link. A second intermediate relay UE (and / or a first intermediate relay UE) that receives the local ID assignment message can transmit the local ID assignment message to a remote UE using the L2 ID included in the message through an operation similar to that of the last relay UE described above. For example, the second intermediate relay UE may specify an SL link corresponding to the L2 ID of the remote UE included in the local ID assignment message based on the L2 ID stored / mapped and related SL information (e.g., association / mapping information between the L2 ID and the SL link) before transmitting / forwarding the local ID request message to the last relay UE, and transmit / forward the local ID assignment message to the first intermediate relay UE through the specified SL link. The first intermediate relay UE may also specify an SL link corresponding to the L2 ID of the remote UE included in the local ID assignment message based on the L2 ID stored / mapped and related SL information (e.g., association / mapping information between the L2 ID and the SL link) before transmitting / forwarding the local ID request message to the second intermediate relay UE, and transmit / forward the local ID assignment message to the remote UE through the specified SL link.

[0206] The proposed method described above can be similarly applied when a message requesting paging monitoring of a remote UE or a remote UE's SIB request message is transmitted to a gNB. For example, the paging monitoring request message and / or the SIB request message may include the L2 ID of the remote UE. Additionally, the message transmitted by the last relay UE or the gNB to the remote UE containing the remote UE's SIB information or paging information may include the L2 ID of said remote UE. For example, when the last relay UE transmits the monitored SIB information or paging information to the remote UE based on said request message, the message containing said SIB information or paging information may include the L2 ID of said remote UE. And / or, if the same message corresponds to multiple remote UEs (or involves multiple remote UEs; for example, if multiple remote UEs have requested the same SIB), the SIB request message or the message containing the SIB information based on said SIB request message may include a list of the L2 IDs of the remote UEs. As described above, such an L2 ID list can be used by an intermediate relay UE (and / or, last relay UE) to store link information regarding the L2 ID and the associated SL link. In this case, the intermediate relay UE and / or last relay UE can perform the necessary U2N operations based on the L2 ID (or L2 ID list) and / or mapping information between the L2 ID and the SL link even before the e2e bearer between the gNB and the remote UE is established.

[0207] FIG. 18 is a diagram illustrating how a first relay UE performs a multi-hop based U2N relay.

[0208] As described above, the first relay UE can operate as an intermediate relay UE in multi-hop based U2N relay communication. For example, the first relay UE can establish an SL connection / indirect connection with the second relay UE connected to the base station, and establish an SL connection / indirect connection with the third relay UE or remote UE. Here, the U2N relay may be a multi-hop based U2N relay communication performed using multi-hops based on a plurality of relay UEs, as described above. In this case, the first relay UE can perform multi-hop U2N relay operation / multi-hop U2N relay communication that relays messages / signals between the base station and the remote UE through multi-hops. Meanwhile, the connection between the relay UE and / or the remote UE can be defined as a direct connection, PC5 sidelink connection, SL connection, direct connection and / or hop, and the connection between the relay UE (or the last relay UE) and the base station can also be defined as a Uu connection / link.

[0209] Referring to FIG. 18, the first relay UE may establish a first connection (e.g., a direct connection with a second relay UE connected to the base station) in the direction toward the base station for the U2N relay, and establish a second connection (e.g., a direct connection with the first remote UE or a direct connection with a third relay UE connected to the first remote UE) in the direction toward the first remote UE (S181). Alternatively, the first relay UE may additionally establish a third connection toward the second remote UE. For example, the first relay UE may establish direct connections toward each of two or more remote UEs. Meanwhile, as described above, even if the first relay UE establishes two or more direct connections in the direction toward each of two or more remote UEs, it may form only one connection (e.g., the first connection) in the direction toward the base station. For example, even though the first relay UE can form / establish multiple connections to multiple remote UEs, it can only establish one connection in the direction toward the base station.

[0210] The first relay UE can receive a first message containing the layer 2 identifier (L2 ID) of the first remote UE through the second connection (S183). The first message may be a local ID request message requesting the base station to assign a local ID to the first remote UE, a message requesting a System Information Block (SIB), or a message requesting paging monitoring. The first message may be a PC5 Radio Resource Control (RRC) message. For example, the first message may be a RemoteUEInformationSidelink message.

[0211] Meanwhile, the first message may be transmitted by the first remote UE even before the appropriate configuration related to the U2N relay is completed by the first relay UE. For example, even if the e2e (end-to-end) bearer between the base station and the first remote UE has not yet been established or has not been completed, the first remote UE may transmit the first message toward the base station. In this way, when the first relay UE receives a message regarding a remote UE responding to the first message through the first connection while the configuration for the U2N relay is not completed, it may not know which connection to use to deliver the message to the remote UE. Therefore, as described below, the first relay UE needs to map the connection through which the first message was received to the L2 ID included in the first message in advance.

[0212] Specifically, the first relay UE can map an L2 ID included in the first message to a second connection where the first message was received (S185). For example, the first relay UE can establish multiple connections toward multiple remote UEs, and among the multiple connections, map one connection where the first message was received to an L2 ID included in the first message.

[0213] The first relay UE can transmit the first message through the first connection (S187). For example, the first relay UE can transmit the first message to the second relay UE to which the first connection has been established.

[0214] Subsequently, the first relay UE may receive a second message responding to the first message through the first connection. The second message may be a local ID assignment message containing a local ID assigned to the first remote UE, a message containing SIB information, or a message containing paging information. In this case, the first relay UE may transmit the second message through a second connection mapped to the L2 ID included in the second message. For example, the first relay UE may specify / determine one connection mapped to the L2 ID included in the second message among a plurality of connections directed toward a plurality of relay UEs, and transmit the second message through the specified / determined one connection.

[0215] FIG. 19 is a diagram illustrating how a second relay UE performs a multi-hop based U2N relay.

[0216] As described above, the second relay UE can operate as the last relay UE in multi-hop based U2N relay communication. For example, the second relay UE is connected to the base station and can establish a direct connection / SL connection with the first relay UE in the direction toward the remote UE. As described above, the U2N relay may be a multi-hop based U2N relay communication performed using multi-hop based on a plurality of relay UEs. In this case, the first relay UE can perform multi-hop U2N relay operation / multi-hop U2N relay communication that relays messages / signals between the base station and the remote UE through multi-hop.

[0217] Referring to FIG. 19, the second relay UE can establish a first connection (e.g., a Uu connection with the base station) in the direction toward the base station for the U2N relay, and establish a second connection (e.g., a direct connection with the first relay UE) in the direction toward the first remote UE (S191). Additionally, the second relay UE can establish a third connection in the direction toward the second remote UE. For example, the second relay UE can establish two or more direct connections in the direction toward each of two or more remote UEs (the two or more direct connections with the two or more remote UEs may have a one-to-one correspondence with each other). Meanwhile, as described above, even if the second relay UE establishes two or more direct connections in the direction toward two or more remote UEs, it can form only one connection (e.g., the first connection) in the direction toward the base station. For example, even if the second relay UE can establish multiple direct connections toward multiple remote UEs, it can establish only one connection toward the base station.

[0218] The second relay UE can receive a first message containing the layer 2 identifier (L2 ID) of the first remote UE through the second connection (S193). The first message may be a local ID request message requesting the base station to assign a local ID to the first remote UE, a message requesting a System Information Block (SIB), or a message requesting paging monitoring. The first message may be a PC5 Radio Resource Control (RRC) message. For example, the first message may be a RemoteUEInformationSidelink message.

[0219] Meanwhile, the first message may be transmitted by the first remote UE even before appropriate settings related to the U2N relay are completed. For example, even if an e2e (end-to-end) bearer between the base station and the first remote UE has not yet been established, the first remote UE can transmit the first message toward the base station, and the first message can be received by the second relay UE. For example, the second relay UE can receive the first message even when appropriate settings for the U2N relay have not been performed in relation to the first remote UE. However, if the second relay UE receives a message from a remote UE responding to the first message via the first connection while the settings for the U2N relay are not yet completed, it may not know which connection to use to transmit the message to the remote UE. Therefore, as described below, the second relay UE needs to map the connection through which the first message was received to the L2 ID included in the first message in advance.

[0220] Specifically, the second relay UE can map the L2 ID included in the first message to the second connection where the first message was received (S195). For example, the second relay UE can establish multiple connections toward multiple remote UEs, and can map the L2 ID included in the first message to one of the multiple connections where the first message was received.

[0221] The second relay UE can transmit a third message to the base station through the first connection to transmit the first message (S197). For example, the second relay UE can transmit a third message, which is a Uu message to transmit the first message, to the base station through the first connection.

[0222] Subsequently, the second relay UE may receive a second message responding to the first message through the first connection. The second message may be a local ID assignment message containing a local ID assigned to the first remote UE, a message containing SIB information, or a message containing paging information. In this case, the second relay UE may transmit the second message through a second connection mapped to the L2 ID included in the second message. For example, the second relay UE may specify / determine one connection mapped to the L2 ID included in the second message among a plurality of connections directed toward a plurality of relay UEs, and transmit the second message through the specified / determined one connection.

[0223] In this way, the proposed invention maps the connection to which a message from a remote UE is received with the L2 ID included in the message, thereby accurately identifying the connection to which a message to be delivered to the remote UE can be transmitted even before the configuration of the gNB associated with the U2N relay is completed. Furthermore, since the proposed invention can effectively transmit a message to the remote UE even when the configuration associated with the U2N relay is not yet completed, service delays caused by configuration delays in multi-hop U2N relay communication can be prevented or minimized.

[0224] Example of a communication system to which the invention is applied

[0225] 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.

[0226] 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.

[0227] FIG. 20 illustrates a communication system to which the present invention is applied.

[0228] Referring to FIG. 20, 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 inter-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices and can be implemented in the form of 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.

[0229] 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).

[0230] 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.

[0231] Example of a wireless device to which the present invention is applied

[0232] FIG. 21 illustrates a wireless device that can be applied to the present invention.

[0233] Referring to FIG. 21, 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. 20.

[0234] 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 / chipset 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 / chipset.

[0235] Specifically, the first wireless device or the first relay UE (100) may include a processor (102) connected to a transceiver (106) and a memory (104). The memory (104) may include at least one program capable of performing operations related to the embodiments described in FIGS. 16 through 19.

[0236] The processor (102) controls the transceiver (106) to establish a first connection toward a base station and a second connection toward a first remote UE for U2N relay (UE to Network), receives a first message including an L2 ID (layer 2 identifier) ​​of the first remote UE through the second connection, transmits the first message through the first connection, and the L2 ID of the remote UE can be mapped to the second connection where the first message was received.

[0237] Alternatively, a processing device may be configured including a processor (102) and a memory (104). In this case, the device may include at least one processor; and at least one memory connected to the at least one processor and storing instructions, wherein the instructions are executed by the at least one processor and cause the first relay UE to: establish a first connection toward a base station and a second connection toward a first remote UE for U2N relay (UE to Network), receive a first message including the L2 ID (layer 2 identifier) ​​of the first remote UE through the second connection, transmit the first message through the first connection, and the L2 ID of the remote UE may be mapped to the second connection where the first message was received.

[0238] 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 sequence diagrams 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.

[0239] Specifically, the second wireless device or the second relay UE (200) may include a processor (202) connected to a transceiver (206) and a memory (204). The memory (204) may include at least one program capable of performing operations related to the embodiments described in FIGS. 16 through 19.

[0240] The processor (202) controls the transceiver (206) to establish a first connection with a base station and a second connection with a first relay UE for a U2N relay (UE to Network), receives a first message including an L2 ID (layer 2 identifier) ​​of a first remote UE through the second connection, transmits a third message to the base station through the first connection to deliver the first message, and the L2 ID of the first remote UE can be mapped to the second connection where the first message was received.

[0241] 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.

[0242] 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.

[0243] 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.

[0244] 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.

[0245] Examples of wireless device applications to which the present invention is applied

[0246] FIG. 22 illustrates another example of a wireless device to which the present invention applies. The wireless device may be implemented in various forms depending on the use-example / service (see FIG. 20).

[0247] Referring to FIG. 22, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 21 and may be composed of various elements, components, units / parts, and / or modules. For example, the wireless device (100, 200) may include a communication unit (110), a control unit (120), a memory unit (130), and additional elements (140). The communication unit may include a communication circuit (112) and transceiver(s) (114). For example, the communication circuit (112) may include one or more processors (102, 202) and / or one or more memories (104, 204) of FIG. 22. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 21. The control unit (120) is electrically connected to the communication unit (110), the memory unit (130), and additional elements (140) and controls the general operation of the wireless device. For example, the control unit (120) may control the electrical / mechanical operation of the wireless device based on a program / code / command / information stored in the memory unit (130). Additionally, the control unit (120) may transmit information stored in the memory unit (130) to an external (e.g., another communication device) via a wireless / wired interface through the communication unit (110), or store information received from an external (e.g., another communication device) via a wireless / wired interface through the communication unit (110) in the memory unit (130).

[0248] The additional element (140) can be configured in various ways depending on the type of wireless device. For example, the additional element (140) may include at least one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 20, 100a), a vehicle (Fig. 20, 100b-1, 100b-2), an XR device (Fig. 20, 100c), a portable device (Fig. 20, 100d), a home appliance (Fig. 20, 100e), an IoT device (Fig. 20, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a fintech device (or financial device), a security device, a climate / environment device, an AI server / device (Fig. 20, 400), a base station (Fig. 20, 200), a network node, etc. Wireless devices can be used in a movable or fixed location depending on the use—e.g., service.

[0249] In FIG. 22, various elements, components, units / parts, and / or modules within the wireless device (100, 200) may be entirely interconnected via a wired interface, or at least partially connected via a communication unit (110). For example, within the wireless device (100, 200), the control unit (120) and the communication unit (110) may be connected via a wire, and the control unit (120) and the first unit (e.g., 130, 140) may be connected wirelessly via the communication unit (110). Additionally, each element, component, unit / part, and / or module within the wireless device (100, 200) may include one or more additional elements. For example, the control unit (120) may be composed of one or more sets of processors. For example, the control unit (120) may be composed of a set of a communication control processor, an application processor, an Electronic Control Unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory and / or a combination thereof.

[0250] Examples of vehicles or autonomous vehicles to which the present invention is applied

[0251] FIG. 23 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.

[0252] Referring to FIG. 23, 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). Blocks 110 / 130 / 140a to 140d each correspond to blocks 110 / 130 / 140 of FIG. 22.

[0253] 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.

[0254] 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.

[0255] Here, the wireless communication technology implemented in the wireless device (XXX, YYY) of this specification may include LTE, NR, and 6G, as well as Narrowband Internet of Things for low-power communication. For example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology and may be implemented according to standards such as LTE Cat NB1 and / or LTE Cat NB2, but is not limited to the names mentioned above. Additionally, or generally, the wireless communication technology implemented in the wireless device (XXX, YYY) of this specification may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and may be referred to by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology may be implemented in at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the names mentioned above. Additionally or generally, wireless communication technology implemented in the wireless device (XXX, YYY) of this specification may include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) with consideration for low-power communication, and is not limited to the names mentioned above. As an example, ZigBee technology can create personal area networks (PANs) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and may be referred to by various names.

[0256] The embodiments described above are combinations of the components and features of the present invention in a specific form. Each component or feature should be considered optional unless otherwise explicitly stated. Each component or feature may be implemented in a form not combined with other components or features. Additionally, it is possible to construct embodiments of the present invention by combining some components and / or features. The order of operations described in the embodiments of the present invention may be changed. Some components or features of one embodiment may be included in another embodiment, or may be replaced with corresponding components or features of another embodiment. It is obvious that embodiments may be constructed by combining claims that do not have an explicit citation relationship in the claims, or that new claims may be included by amendment after filing.

[0257] In this document, embodiments of the present invention are described primarily with a focus on the signal transmission and reception relationship between a terminal and a base station. This transmission and reception relationship is extended in the same or similar manner to signal transmission and reception between a terminal and a relay or between a base station and a relay. Specific operations described in this document as being performed by a base station may, in some cases, be performed by an upper node. That is, it is self-evident that various operations performed for communication with a terminal in a network consisting of multiple network nodes including a base station may be performed by the base station or other network nodes other than the base station. The base station may be replaced by terms such as fixed station, Node B, eNode B (eNB), and access point. Additionally, the terminal may be replaced by terms such as User Equipment (UE), Mobile Station (MS), and Mobile Subscriber Station (MSS).

[0258] Embodiments according to the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of implementation by hardware, one embodiment of the present invention may be implemented by one or more ASICs (application specific integrated circuits), DSPs (digital signal processors), DSPDs (digital signal processing devices), PLDs (programmable logic devices), FPGAs (field programmable gate arrays), processors, controllers, microcontrollers, microprocessors, etc.

[0259] In the case of implementation by firmware or software, an embodiment of the present invention may be implemented in the form of a module, procedure, function, etc., that performs the functions or operations described above. Software code may be stored in a memory unit and executed by a processor. The memory unit may be located inside or outside the processor and may exchange data with the processor by various means already known.

[0260] It is obvious to those skilled in the art that the present invention may be embodied in other specific forms without departing from the features of the invention. Accordingly, the above detailed description should not be interpreted restrictively in all respects and should be considered exemplary. The scope of the invention shall be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the invention are included within the scope of the invention.

[0261] The embodiments of the present invention as described above can be applied to various mobile communication systems.

Claims

In the method using the first relay UE (User Equipment), A step of establishing a first connection toward a base station and a second connection toward a first remote UE for U2N relay (UE to Network); A step of receiving a first message including the L2 ID (layer2 identifier) ​​of the first remote UE through the second connection; and It includes the step of transmitting the first message through the first connection, A method in which the first relay UE maps the L2 ID of the first remote UE to the second connection in which the first message is received. In paragraph 1, A step of receiving a second message through the first connection; and A method further comprising the step of transmitting the second message through the second connection mapped to the L2 ID of the first remote UE, based on the fact that the second message contains an L2 ID identical to the L2 ID of the first remote UE. In paragraph 2, The first message above is a local ID request message requesting the assignment of a local ID to the first remote UE, and A method in which the second message above is a local ID assignment message that assigns the local ID to the first remote UE. In paragraph 1, A method in which the first message above is a message requesting a SIB (System Information Block) or a message requesting paging monitoring. In paragraph 1, Step of establishing a third connection toward a second remote UE; A step of receiving a second message through the first connection; and A method further comprising the step of transmitting the second message through one of the second and third connections mapped to an L2 ID included in the second message. In paragraph 1, A method in which the L2 ID of the first remote UE is mapped to the second connection where the first message is received, based on the fact that an e2e (end-to-end) bearer between the base station and the first remote UE is not established. In paragraph 1, A method in which the second connection is a direct connection with the first remote UE or a direct connection with a third relay UE that is directly connected to the first remote UE. In paragraph 1, The above first message is a PC5 RRC (Radio Resource Control) message, method. In paragraph 1, A method in which the first connection is a connection between the second relay UE connected to the base station and the first relay UE. In at least one non-transient computer-readable recording medium, Includes instructions that perform operations when executed by at least one processor, The above operations are, Establish a first connection toward the base station and a second connection toward the first remote UE for U2N relay (UE to Network); Receiving a first message including the L2 ID (layer2 identifier) ​​of the first remote UE through the second connection; and It includes transmitting the first message through the first connection, The L2 ID of the above remote UE is at least one non-transient computer-readable recording medium mapped to the second connection where the first message was received. In the first relay UE (User Equipment), RF (Radio Frequency) transceiver; and It includes a processor connected to the above RF transceiver, and The processor controls the RF transceiver to establish a first connection toward a base station and a second connection toward a first remote UE for U2N relay (UE to Network), receives a first message including the L2 ID (layer 2 identifier) ​​of the first remote UE through the second connection, and transmits the first message through the first connection. The L2 ID of the above remote UE is a first relay UE mapped to the second connection where the first message was received. In Paragraph 11, A first relay UE, wherein the processor controls the RF transceiver to receive a second message through the first connection and transmits the second message through the second connection mapped to the L2 ID of the first remote UE based on the fact that the second message contains an L2 ID identical to the L2 ID of the first remote UE. In a processing device that controls a first relay UE (User Equipment), At least one processor; and The first relay UE includes at least one memory connected to the at least one processor and storing instructions, wherein the instructions are executed by the at least one processor. For U2N relay (UE to Network), establish a first connection toward a base station and a second connection toward a first remote UE, receive a first message including the L2 ID (layer 2 identifier) ​​of the first remote UE through the second connection, and transmit the first message through the first connection. A processing device in which the L2 ID of the above remote UE is mapped to the second connection where the above first message was received. In the method using the second relay UE (User Equipment), A step of establishing a first connection with a base station and a second connection with the first relay UE for U2N relay (UE to Network); A step of receiving a first message including the L2 ID (layer2 identifier) ​​of the first remote UE through the second connection; and It includes the step of transmitting a third message for transmitting the first message to a base station through the first connection, and A method in which the second relay UE maps the L2 ID of the first remote UE to the second connection in which the first message is received. In the second relay UE (User Equipment), RF (Radio Frequency) transceiver; and It includes a processor connected to the above RF transceiver, and The above processor controls the RF transceiver to establish a first connection with a base station and a second connection with a first relay UE for U2N relay (UE to Network), receives a first message including the L2 ID (layer 2 identifier) ​​of a first remote UE through the second connection, and transmits a third message to the base station through the first connection to deliver the first message. The L2 ID of the first remote UE is a second relay UE mapped to the second connection where the first message was received.

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