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

Abstract

Disclosed are a method for performing communication in a wireless communication system and a device therefor according to various embodiments. The device may receive a first message requesting radio resource control (RRC) connection establishment for a first UE related to a UE to network (U2N) relay, and transmit, to a base station, a second message including information requesting allocation of a local identifier (ID) for the first UE on the basis of the first message.

Description

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

[0001] A method for performing multi-hop based relay communication in a wireless communication system and a device therefor are provided.

[0002] Wireless communication systems are multiple access systems that support communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power, etc.). Examples of multiple access systems include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and multi-carrier frequency division multiple access (MC-FDMA).

[0003] Sidelink (SL) refers to a communication method that establishes a direct link between user equipment (UE), allowing voice or data to be exchanged directly between terminals without going through a base station (BS). SL is being considered as a solution to address the burden on base stations due to rapidly increasing data traffic.

[0004] V2X (vehicle-to-everything) refers to a communication technology that exchanges information with other vehicles, pedestrians, and infrastructure-based objects through wired / wireless communication. V2X can be divided into four types: V2V (vehicle-to-vehicle), V2I (vehicle-to-infrastructure), V2N (vehicle-to-network), and V2P (vehicle-to-pedestrian). V2X communication can be provided through the PC5 interface and / or Uu interface.

[0005] Meanwhile, as more and more communication devices demand greater communication capacity, the need for improved mobile broadband communication compared to existing radio access technology (RAT) is emerging. Accordingly, communication systems that consider services or terminals sensitive to reliability and latency are being discussed. Next-generation wireless access technologies that consider improved mobile broadband communication, massive machine type communication (MTC), and ultra-reliable and low latency communication (URLLC) can be called new radio access technology (RAT) or new radio (NR). NR can also support vehicle-to-everything (V2X) communication.

[0006] Figure 1 is a diagram for comparing and explaining V2X communication based on RAT before NR and V2X communication based on NR.

[0007] In relation to V2X communication, in RATs prior to NR, methods for providing safety services based on V2X messages such as Basic Safety Message (BSM), Cooperative Awareness Message (CAM), and Decentralized Environmental Notification Message (DENM) were mainly discussed. V2X messages may include location information, dynamic information, attribute information, etc. For example, a terminal may transmit a CAM of a periodic message type and / or a DENM of an event triggered message type to another terminal.

[0008] For example, a CAM may include basic vehicle information such as dynamic vehicle status information, such as direction and speed, static vehicle data, such as dimensions, external lighting conditions, and route history. For example, a terminal may broadcast a CAM, and the latency of the CAM may be less than 100 ms. For example, in the event of an emergency, such as a vehicle breakdown or accident, a 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, various V2X scenarios have been proposed in NR in relation to V2X communications. For example, various V2X scenarios may include vehicle platooning, advanced driving, extended sensors, and remote driving.

[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 in the group can receive periodic data from the lead vehicle. For example, vehicles in the group can use this periodic data to narrow or widen the gap between vehicles.

[0011] For example, based on improved driving, vehicles can become semi-autonomous or fully automated. For example, each vehicle can adjust its trajectories or maneuvers based on data acquired from local sensors of nearby vehicles and / or nearby logical entities. Furthermore, for example, each vehicle can share driving intentions with nearby vehicles.

[0012] For example, based on extended sensors, raw data, 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 its environment better than it can perceive using its own sensors.

[0013] For example, based on remote driving, a remote driver or V2X application can operate or control the remote vehicle for people who cannot drive or for remote vehicles located in hazardous environments. For example, in cases where the route is predictable, such as public transportation, cloud computing-based driving can be utilized to operate or control the remote vehicle. Additionally, access to a cloud-based back-end service platform, for example, can be considered for remote driving.

[0014] Meanwhile, a method to specify service requirements for various V2X scenarios, such as vehicle platooning, enhanced driving, expanded sensors, and remote driving, is being discussed in NR-based V2X communication.

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

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

[0017] A method by a first relay UE (User Equipment) according to one aspect comprises the steps of: receiving a first message requesting establishment of a radio resource control (RRC) connection for a first UE associated with a U2N (UE to Network) relay; and transmitting a second message to a base station, based on the first message, including information requesting allocation of a local identifier (ID) for the first UE; wherein, based on the U2N relay being multi-hop based, the second message may further include type information of the first UE.

[0018] Alternatively, the second message is a SidelinkUEInformationNR message in which a source ID for the first relay UE and a destination ID for the first UE are set, and the second message includes first type information for the source ID and second type information for the destination ID.

[0019] Alternatively, the method further comprises the step of transmitting the first message including an SRAP (Sidelink Relay Adaptation Protocol) header related to the first UE to the base station.

[0020] Alternatively, the SRAP header is characterized in that it includes a local ID and bearer ID of the first UE allocated by the base station.

[0021] Alternatively, the first relay UE is characterized in that it receives a third message for establishing an RRC connection to the first UE from the base station, and transmits a message with an SRAP header related to the first relay UE removed from the third message to the first UE.

[0022] Alternatively, the method further comprises receiving a fourth message having an SRAP (Sidelink Relay Adaptation Protocol) header including a local ID not assigned to the first UE, wherein the first relay UE forwards the fourth message to the first UE based on the fourth message further including mapping information between the local ID and the ID for the first UE.

[0023] Alternatively, the first message is characterized in that it further includes UE type information for the first UE.

[0024] Alternatively, based on the first relay UE being in an RRC idle or RRC inactive state, the first relay UE further transmits a fourth message requesting RRC connection establishment of the first relay UE to the base station, and based on a message for establishing an RRC connection for the first relay UE being received from the base station, the first relay UE forwards the first message to the base station.

[0025] Alternatively, the first UE is an intermediate relay UE performing the U2N relay operation connected to the base station via the first relay UE, and the first relay UE is a relay UE directly connected to the base station.

[0026] According to another aspect, a non-transitory computer-readable storage medium having recorded thereon instructions for performing the method described above may be provided.

[0027] According to another aspect, a first relay UE performing the method described above may be provided.

[0028] According to another aspect, a processing device may be provided for controlling a first relay UE performing the method described above.

[0029] According to another aspect, a method by a base station includes the steps of: receiving, from a first relay UE, a first message including information requesting allocation of a local identifier (ID) for a first UE associated with a U2N (UE to Network) relay; and receiving, through the first relay UE, a second message requesting establishment of a radio resource control (RRC) connection for the first UE; wherein, based on the U2N relay being multi-hop based, the second message may further include type information of the first UE.

[0030] According to another aspect, a second relay UE may be provided that performs the method described above.

[0031] According to one embodiment, multi-hop based U2N relay communication can be performed more accurately and efficiently in a wireless communication system.

[0032] The effects that can be obtained in various embodiments are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

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

[0034] Figure 1 is a diagram for comparing and explaining V2X communication based on RAT before NR and V2X communication based on NR.

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

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

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

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

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

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

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

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

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

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

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

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

[0047] Figure 14 is a diagram for explaining multi-hop based U2N relay communication.

[0048] FIG. 15 and FIG. 16 are diagrams illustrating an initial connection setup procedure for U2N relay operation according to a given scenario.

[0049] Figure 17 is a drawing illustrating a method for performing an initial connection setup procedure for MH-relay operation.

[0050] FIG. 18 is a diagram illustrating how a first relay UE performs an initial connection setup procedure for a multi-hop based U2N relay.

[0051] FIG. 19 is a diagram illustrating how a base station performs an initial connection setup procedure for a multi-hop based U2N relay.

[0052] Figure 20 illustrates a communication system applied to the present invention.

[0053] Figure 21 illustrates a wireless device applicable to the present invention.

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

[0055] Figure 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 code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and multi-carrier frequency division multiple access (MC-FDMA).

[0057] Sidelink refers to a communication method that establishes a direct link between user equipment (UE), allowing voice or data to be exchanged directly between terminals without going through a base station (BS). Sidelink is being considered as a solution to address the burden on base stations due to rapidly increasing data traffic.

[0058] V2X (vehicle-to-everything) refers to a communication technology that exchanges information with other vehicles, pedestrians, and infrastructure-based objects through wired / wireless communication. V2X can be divided into four types: V2V (vehicle-to-vehicle), V2I (vehicle-to-infrastructure), V2N (vehicle-to-network), and V2P (vehicle-to-pedestrian). V2X communication can be provided through the PC5 interface and / or Uu interface.

[0059] Meanwhile, as more and more communication devices demand greater communication capacity, the need for improved mobile broadband communication compared to existing radio access technology (RAT) is emerging. Accordingly, communication systems that consider services or terminals sensitive to reliability and latency are being discussed. Next-generation wireless access technologies that consider improved mobile broadband communication, massive MTC, and URLLC (Ultra-Reliable and Low Latency Communication) can be called new radio access technology (RAT) or new radio (NR). NR can also support V2X (vehicle-to-everything) communication.

[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 with wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (global system for mobile communications) / GPRS (general packet radio service) / EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented with wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (evolved UTRA). IEEE 802.16m is an evolution of IEEE 802.16e, providing backward compatibility with systems based on IEEE 802.16e. UTRA is part of UMTS (universal mobile telecommunications system). 3GPP (3rd generation partnership project) LTE (long term evolution) is a part of E-UMTS (evolved UMTS) that uses E-UTRA (evolved-UMTS terrestrial radio access), employing OFDMA in the downlink and SC-FDMA in the uplink.LTE-A (advanced) is an evolution of 3GPP LTE.

[0061] 5G NR, the successor to LTE-A, is a new clean-slate mobile communications system featuring high performance, low latency, and high availability. 5G NR can utilize all available spectrum resources, from low-frequency bands below 1 GHz, mid-frequency bands between 1 GHz and 10 GHz, and high-frequency (millimeter wave) bands above 24 GHz.

[0062] For clarity, the description will focus on LTE-A or 5G NR, but the technical ideas of the embodiment(s) are not limited thereto.

[0063] Figure 2 illustrates the architecture of an applicable LTE system. This may be referred to as an Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN) or a Long Term Evolution (LTE) / LTE-A system.

[0064] Referring to FIG. 2, the E-UTRAN includes a base station (20; 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 a mobile station (MS), a user terminal (UT), a subscriber station (SS), a mobile terminal (MT), a wireless device, etc. 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 an evolved-NodeB (eNB), a base transceiver system (BTS), an access point, etc.

[0065] Base stations (20) can be connected to each other via the X2 interface. The base station (20) is connected to an EPC (Evolved Packet Core, 30) via the S1 interface, more specifically, to an MME (Mobility Management Entity) via the S1-MME, and to an S-GW (Serving Gateway) via 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 about terminal access and capabilities, and this information is primarily used for terminal mobility management. The S-GW is a gateway with the E-UTRAN as its endpoint, and the P-GW is a gateway with the PDN as its endpoint.

[0067] The layers of the radio interface protocol between the terminal and the network can be divided into L1 (Layer 1), L2 (Layer 2), and L3 (Layer 3) based on the three lower layers of the Open System Interconnection (OSI) standard model, which is widely known in communication systems. Among these, the physical layer belonging to Layer 1 provides an information transfer service using a physical channel, and the RRC (Radio Resource Control) layer located in Layer 3 controls radio resources between the terminal and the network. To this end, the RRC layer exchanges RRC messages between the terminal and the base station.

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

[0069] Referring to FIG. 3, the NG-RAN may include a gNB and / or an eNB that provides user plane and control plane protocol termination to the UE. FIG. 7 illustrates a case where only a gNB is included. The gNB and eNB are connected to each other via an Xn interface. The gNB and eNB are connected to the 5th generation core network (5G Core Network: 5GC) via the NG interface. More specifically, the gNB is connected to the access and mobility management function (AMF) via the NG-C interface, and the gNB is connected to the user plane function (UPF) via the NG-U interface.

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

[0071] Referring to FIG. 4, radio frames can be used for uplink and downlink transmission in NR. A radio frame has a length of 10 ms and can be defined as two 5 ms half-frames (Half-Frames, HF). A half-frame can include five 1 ms sub-frames (Subframes, SF). A sub-frame can be divided into one or more slots, and the number of slots within a sub-frame can be determined by the Subcarrier Spacing (SCS). Each slot can include 12 or 14 OFDM (A) symbols depending on the cyclic prefix (CP).

[0072] When normal CP is used, each slot can contain 14 symbols. When extended CP is used, each slot can contain 12 symbols. Here, the symbols can include OFDM symbols (or CP-OFDM symbols), SC-FDMA (Single Carrier - FDMA) symbols (or DFT-s-OFDM (Discrete Fourier Transform-spread-OFDM) symbols).

[0073] Table 1 below shows the number of symbols per slot ((N)) depending on 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 ) is an example.

[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 illustrates the number of symbols per slot, the number of slots per frame, and the number of slots per subframe according to SCS when 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, OFDM(A) numerology (e.g., SCS, CP length, etc.) may be set differently between multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., subframe, slot, or TTI) (conveniently referred to as TU (Time Unit)) consisting of the same number of symbols may be set differently between the merged cells.

[0078] In NR, multiple numerologies, or SCSs, can be supported to support various 5G services. For example, a 15 kHz SCS can support wide areas in traditional cellular bands, while a 30 kHz / 60 kHz SCS can support dense urban areas, lower latency, and wider carrier bandwidth. A 60 kHz or higher SCS can support bandwidths greater than 24.25 GHz to overcome phase noise.

[0079] The NR frequency band can be defined by two types of frequency ranges. The two types of frequency ranges can be FR1 and FR2. The numerical values ​​of the frequency ranges can be changed, and for example, the two types of frequency ranges can be as shown in Table 3 below. Among the frequency ranges used in the NR system, FR1 can mean the "sub 6 GHz range", and FR2 can mean the "above 6 GHz range" and can be called millimeter wave (mmW).

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

[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 Figure 5, a slot includes multiple symbols in the time domain. For example, in the case of a normal CP, one slot may include 14 symbols, but in the case of an extended CP, one slot may include 12 symbols. Alternatively, in the case of a normal CP, one slot may include 7 symbols, but in the case of an extended CP, one slot may include 6 symbols.

[0085] A carrier includes multiple subcarriers in the frequency domain. An RB (Resource Block) can be defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A BWP (Bandwidth Part) can be defined as multiple consecutive (P)RBs ((Physical) Resource Blocks) in the frequency domain, and can correspond to one numerology (e.g., SCS, CP length, etc.). A carrier can include up to N (e.g., 5) BWPs. Data communication can be performed through activated BWPs. Each element can be referred to as a Resource Element (RE) in the resource grid, and one complex symbol can be mapped to it.

[0086] Meanwhile, the wireless interface between terminals or between terminals and a network may be composed of an L1 layer, an L2 layer, and an L3 layer. In various embodiments of the present disclosure, the L1 layer may refer to a physical layer. Furthermore, for example, the L2 layer may refer to at least one of a MAC layer, an RLC layer, a PDCP layer, and an SDAP layer. Furthermore, for example, the L3 layer may refer to an RRC layer.

[0087] FIG. 6 illustrates a communication structure that can be provided in a 6G system according to an 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 include:

[0089] - Satellite integrated network

[0090] - Connected Intelligence: Unlike previous generations of wireless communication systems, 6G is revolutionary, upgrading the wireless evolution from "connected objects" to "connected intelligence." AI can be applied at every stage of the communication process (or at every signal processing step, as described below).

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

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

[0093] Some general requirements for the new network characteristics of 6G, such as the 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 communications is a key feature of 6G wireless communication systems. Therefore, radar systems will be integrated with 6G networks.

[0098] - Softwarization and virtualization

[0099] Below, the core implementation technologies of the 6G system are described.

[0100] - Artificial Intelligence: Incorporating AI into communications can streamline and improve real-time data transmission. AI can use numerous analytics to determine how complex target tasks should be performed. This means AI can increase efficiency and reduce processing delays. Time-consuming tasks such as handovers, network selection, and resource scheduling can be performed instantly using AI. AI can also play a crucial role in machine-to-machine (M2M), machine-to-human, and human-to-machine communications. Furthermore, AI can facilitate rapid communication in brain-computer interfaces (BCIs). AI-based communication systems can be supported by metamaterials, intelligent structures, intelligent networks, intelligent devices, intelligent cognitive radios, self-sustaining wireless networks, and machine learning.

[0101] - THz communication (terahertz communication): Data rates can be increased by increasing the bandwidth. This can be achieved by using sub-THz communication with wide bandwidths and applying advanced massive MIMO technology. THz waves, also known as sub-millimeter waves, typically refer to the frequency range between 0.1 THz and 10 THz, with corresponding wavelengths ranging from 0.03 mm to 3 mm. The 100 GHz to 300 GHz band (sub-THz band) is considered a key part of the THz spectrum for cellular communications. Adding the sub-THz band to the mmWave band will increase the capacity of 6G cellular communications. Among the defined THz bands, 300 GHz to 3 THz lies in the far infrared (IR) frequency band. While part of the optical band, the 300 GHz to 3 THz band lies at the boundary of the optical band, immediately following the RF band. Therefore, this 300 GHz to 3 THz band exhibits similarities to RF.

[0102] Figure 7 illustrates the electromagnetic spectrum according to one embodiment of the present disclosure. The embodiment of Figure 7 can be combined with various embodiments of the present disclosure. Key characteristics of THz communications include (i) a widely available bandwidth to support very high data rates, and (ii) high path loss at high frequencies (highly directional antennas are essential). The narrow beamwidth generated by the highly directional antenna reduces interference. The small wavelength of THz signals allows for a much larger number of antenna elements to be integrated into devices and base stations operating in this band. This enables the use of advanced adaptive array techniques to 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 surface

[0114] - metaverse

[0115] - Block chain

[0116] Unmanned aerial vehicles (UAVs): UAVs, or drones, will be a key element in 6G wireless communications. In most cases, high-speed data wireless connectivity can be provided using UAV technology. Base stations (BSs) can be installed on UAVs to provide cellular connectivity. UAVs may offer specific capabilities not found in fixed BS infrastructure, such as easy deployment, robust line-of-sight links, and controlled mobility. During emergencies such as natural disasters, deploying terrestrial communications infrastructure is not economically feasible and sometimes cannot provide services in volatile environments. UAVs can easily handle these situations. UAVs will become a new paradigm in wireless communications. This technology facilitates three fundamental requirements for wireless networks: enhanced mobile broadband (eMBB), URLLC, and mMTC. UAVs can also support various purposes, such as enhancing network connectivity, fire detection, disaster emergency services, security and surveillance, pollution monitoring, parking monitoring, and accident monitoring. Therefore, UAV technology is recognized as one of the most important technologies for 6G communications.

[0117] - Autonomous driving (self-driving): V2X (vehicle to everything), a key element in building autonomous driving infrastructure, can be a technology that allows cars to communicate and share with various elements on the road for autonomous driving, such as vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) wireless communication. Fast transmission speeds and low-latency technologies are essential to maximize autonomous driving performance and ensure high safety. Furthermore, in the future, autonomous driving will go beyond simply providing warnings or guidance messages to drivers and may require active intervention in vehicle operation and direct control of the vehicle in dangerous situations. To this end, the amount of information that needs to be transmitted and received may become enormous, so 6G is expected to maximize autonomous driving with faster transmission speeds and lower latency than 5G.

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

[0119] Below, the SL synchronization signal (Sidelink Synchronization Signal, SLSS) and synchronization information are described.

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

[0121] PSBCH (Physical Sidelink Broadcast Channel) may be a (broadcast) channel that transmits basic (system) information that a terminal must know first before transmitting or receiving an SL signal. For example, the basic information may be information related to SLSS, duplex mode (DM), TDD UL / DL (Time Division Duplex Uplink / Downlink) configuration, resource pool-related information, type of application related to SLSS, subframe offset, broadcast information, etc. For example, in NR V2X, for evaluating PSBCH performance, 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 supporting periodic transmission (e.g., SL SS (Synchronization Signal) / PSBCH block, hereinafter referred to as S-SSB (Sidelink-Synchronization Signal Block)). The S-SSB may have the same numerology (i.e., SCS and CP length) as the PSCCH (Physical Sidelink Control Channel) / PSSCH (Physical Sidelink Shared Channel) in the carrier, and the transmission bandwidth may be within a (pre-)configured SL BWP (Sidelink BWP). For example, the bandwidth of the S-SSB may be 11 RBs (Resource Blocks). For example, the PSBCH may span 11 RBs. And, the frequency location of the S-SSB may be (pre-)configured. Therefore, the terminal does not need to perform hypothesis detection in the frequency to discover the S-SSB in the carrier.

[0123] Meanwhile, in the 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 a transmitting terminal to transmit an S-SSB may become shorter. Accordingly, the coverage of the S-SSB may decrease. Therefore, in order to ensure the coverage of the S-SSB, the transmitting terminal may transmit one or more S-SSBs to a receiving terminal within one S-SSB transmission period according to the SCS. For example, the number of S-SSBs that the transmitting terminal transmits to the receiving terminal within one S-SSB transmission period may be pre-configured or configured for the transmitting terminal. For example, the S-SSB transmission period may be 160 ms. For example, an S-SSB transmission period of 160 ms may be supported for all SCSs.

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

[0125] For example, when 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 period. For example, when 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 period.

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

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

[0128] Referring to FIG. 9, the term "terminal" in V2X or SL communication may primarily refer to a user's terminal. However, if a network device such as a base station transmits and receives signals according to a 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 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 a signal from terminal 1 within the resource pool.

[0130] Here, if terminal 1 is within the connection range of the base station, the base station can 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 can inform terminal 1 of the resource pool, or terminal 1 can use a pre-configured resource pool.

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

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

[0133] Referring to Figure 10, the entire frequency resources of the resource pool can be divided into NF units, and the entire time resources of the resource pool can be divided into NT units. Therefore, a total of NF * NT resource units can be defined within the resource pool. Figure 10 illustrates an example where the resource pool repeats with a cycle of NT subframes.

[0134] As shown in Figure 10, a single resource unit (e.g., Unit #0) may appear periodically and repeatedly. Alternatively, to achieve diversity effects in the time or frequency dimensions, 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 resource unit structure, a resource pool may refer to a set of resource units that a terminal wishing to transmit an SL signal can use for transmission.

[0135] Resource pools can be subdivided into several categories. For example, based on the content of the SL signal transmitted from each resource pool, resource pools can be categorized as follows:

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

[0137] (2) The SL data channel (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 together with SL data on the same resource unit, only the SL data channel excluding SA information may be transmitted from the resource pool for the SL data channel. In other words, the REs (Resource Elements) that were used to transmit SA information on individual resource units within the SA resource pool may still be used to transmit SL data in the resource pool of the SL data channel. For example, the transmitting terminal may transmit the PSSCH by mapping it to consecutive PRBs.

[0138] (3) A discovery channel may be a resource pool for transmitting terminals to transmit information such as their IDs. Through this, transmitting terminals can enable neighboring terminals to discover them.

[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 properties of the SL signal. For example, even if it is the same SL data channel or discovery message, it may be again divided into different resource pools depending on the transmission timing determination method of the SL signal (for example, whether it is transmitted at the time of reception of a synchronization reference signal or whether it is transmitted by applying a certain timing advance at the time of reception), the resource allocation method (for example, whether the base station designates transmission resources for individual signals to individual transmitting terminals or whether individual transmitting terminals independently select individual signal transmission resources within the resource pool), the signal format (for example, the number of symbols each SL signal occupies in one subframe or the number of subframes used for 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 can 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 Figure 11, a common resource block (CRB) may be a carrier resource block numbered from one end of a carrier band to the other. Furthermore, a PRB may be a numbered resource block within each BWP. Point A may indicate a common reference point for the resource block grid.

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

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

[0144] PSBCH (Physical Sidelink Broadcast Channel) may be a (broadcast) channel that transmits basic (system) information that a terminal must know first before transmitting or receiving an SL signal. For example, the basic information may be information related to SLSS, duplex mode (DM), TDD UL / DL (Time Division Duplex Uplink / Downlink) configuration, resource pool-related information, type of application related to SLSS, subframe offset, broadcast information, etc. For example, in order to evaluate PSBCH performance, in NR V2X, the payload size of PSBCH may be 56 bits, including a 24-bit CRC (Cyclic Redundancy Check).

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

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

[0147] Referring to (a) of FIG. 12, 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, a first terminal may receive information related to a dynamic grant (DG) resource and / or information related to a configured grant (CG) resource from a base station. For example, a CG resource may include a CG type 1 resource or a CG type 2 resource. In this specification, a DG resource may be a resource that a base station configures / allocates to the first terminal via downlink control information (DCI). In this specification, a CG resource may be a (periodic) resource that a base station configures / allocates to the first terminal via DCI and / or an RRC message. For example, in the case of a CG type 1 resource, the base station may transmit an RRC message including information related to the CG resource to the first terminal. For example, in the case of a CG type 2 resource, the base station may transmit an RRC message including information related to the CG resource to the first terminal, and the base station may transmit a DCI related to activation or release of the CG resource to the first terminal.

[0149] In step S1510, the first terminal may transmit a PSCCH (e.g., Sidelink Control Information (SCI) or 1st-stage SCI) to the second terminal based on the resource scheduling. In step S1220, the first terminal may transmit a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) related to the PSCCH to the second terminal. In step S1230, the first terminal may receive a PSFCH related to the PSCCH / PSSCH from the second terminal. For example, HARQ feedback information (e.g., NACK information or ACK information) may be received from the second terminal via the PSFCH. In step S1240, the first terminal may transmit / report HARQ feedback information to the base station via a PUCCH or a PUSCH. For example, the HARQ feedback information reported to the base station may be information generated by the first terminal based on the HARQ feedback information received from the second terminal. For example, the HARQ feedback information reported to the base station may be information generated by the first terminal based on a rule set in advance. For example, the DCI may be DCI for scheduling SL.

[0150] Referring to (b) of FIG. 12, in resource allocation mode 2, a terminal can determine an SL transmission resource within the SL resources set by the base station / network or within the preset SL resources. For example, the set SL resources or the preset SL resources may be a resource pool. For example, the terminal can autonomously select or schedule resources for SL transmission. For example, the terminal can perform SL communication by selecting a resource by itself within the set resource pool. For example, the terminal can select a resource by itself within a selection window by performing sensing and resource (re)selection procedures. For example, the sensing can be performed on a subchannel basis. For example, in step S1210, a first terminal that has selected a resource by itself within the resource pool can transmit a PSCCH (e.g., Sidelink Control Information (SCI) or 1st-stage SCI) to a second terminal using the resource. In step S1220, the first terminal may transmit a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) related to the PSCCH to the second terminal. In step S1230, the first terminal may receive a PSFCH related to the PSCCH / PSSCH from the second terminal.

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

[0152] Referring to (a) or (b) of FIG. 12, in step S1530, the first terminal may receive a PSFCH. For example, the first terminal and the second terminal may determine PSFCH resources, and the second terminal may use the PSFCH resources to transmit HARQ feedback to the first terminal.

[0153] Referring to (a) of FIG. 12, in step S1540, the first terminal may transmit SL HARQ feedback to the base station via PUCCH and / or PUSCH.

[0154] Figure 13 is a diagram for explaining the control plane procedure of L2 U2N relay (UE-to-Network Relay).

[0155] The PC5-RRC aspect PC5 unicast link establishment procedure of Rel-16 NR V2X can be reused to establish a secure unicast link for L2 U2N relay (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 via the relay UE.

[0156] For both in-coverage and out-of-coverage scenarios, when a remote UE initiates the first RRC message to establish a connection with a gNB, the PC5 L2 configuration for transmissions between the remote UE and the U2N relay UE can be based on the RLC / MAC configuration defined in the standard. The establishment of Uu SRB1 / SRB2 and DRB of the remote UE follows the legacy Uu configuration procedure for the L2 U2N relay.

[0157] A given scenario (TS 38.300) describes the control plane procedures of an L2 U2N relay as follows:

[0158] In step S1300, the remote UE and the relay UE can perform a discovery procedure and establish a PC5-RRC connection in step S1301 based on the existing Rel-16 procedure.

[0159] In step S1302, the remote UE can transmit 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 RRCSetup delivery to the remote UE uses the default configuration of PC5. If the relay UE is not initiated in RRC_CONNECTED, it must perform its own connection establishment upon receiving the message for the default L2 configuration of PC5.

[0160] In step S1304, the gNB and the relay UE perform a relay channel setup procedure via Uu. Depending on the configuration of the gNB, the relay / remote UE establishes an RLC channel for relaying SRB1 to the remote UE via PC5. This step prepares the relay channel for SRB1.

[0161] In step S1305, a remote UE SRB1 message (e.g., an RRCSetupComplete message) is transmitted to the gNB via the relay UE using the SRB1 relay channel over PC5. The remote UE is then RRC connected over Uu.

[0162] In steps S1306 and S1307, the remote UE and the gNB establish security according to legacy procedures, and the security message is transmitted through the Relay UE.

[0163] In steps S1308 and S1309, the gNB transmits RRCReconfiguration to the remote UE via the relay UE to set up the relay SRB2 / DRB. The remote UE responds by transmitting RRCReconfigurationComplete to the gNB via the relay UE.

[0164] 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.

[0165] In the above scenario, in addition to the connection setup procedure, for L2 UE-to-Network relay:

[0166] - RRC reconfiguration and RRC disconnection procedures can reuse legacy RRC procedures with message content / configuration design left in the WI phase.

[0167] - The RRC connection re-establishment and RRC connection resumption procedures can be reused as a baseline by considering the connection establishment procedure of the L2 U2N relay above to handle relay-specific parts along with the message content / structure design. The message content / structure can be defined later.

[0168] The above discovery procedure may define discovery model A and discovery model B. Discovery model A may be a method in which a relay UE periodically broadcasts a message announcing its presence (Announcement message). Discovery model B may be a method in which a device (remote UE) wishing to perform relay communication periodically broadcasts a message requesting relay communication (solicitation message) (see 3GPP TS 23.304).

[0169] Additionally, the common identifier of 5G ProSe UE-to-Network Relay in the discovery procedure may be as follows (see 3GPP TS 23.304). The parameters below may be used in the 5G ProSe UE-to-Network Relay Discovery Announcement message (Model A). Here, the Source Layer-2 ID and the Destination Layer-2 ID are used to send and receive the discovery message, and the Announcer Info and Relay Service Code may be included in the discovery message.

[0170] - Source Layer-2 ID: 5G ProSe UE-to-Network Relay can select its own Source Layer-2 ID for 5G ProSe UE-to-Network Relay Discovery.

[0171] - Destination Layer-2 ID: Destination Layer-2 ID selected for 5G ProSe UE-to-Network Relay Discovery (see 3GPP TS 23.304 Section 5.1.4.1)

[0172] - Announcer Info: Information about the announcing user (e.g., user information ID) can be provided.

[0173] - Relay Service Code: This may be a parameter that identifies the connection service that the 5G ProSe UE-to-Network Relay provides to the 5G ProSe Remote UE. The relay service code may be configured in the 5G ProSe UE-to-Network Relay for advertisement. In addition, the relay service code may identify a user to whom the 5G ProSe UE-to-Network Relay is authorized to provide services, and may be used to select relevant security policies or information required for authentication and authorization between the 5G ProSe Remote UE and the 5G ProSe UE-to-Network Relay (for example, a relay service code of a relay for police officers only may be different from a relay service code of a relay for firefighters only. This is to support Internet access even if they potentially provide connections to the same DN).

[0174] The following parameters can be used in the 5G ProSe UE-to-Network Relay Discovery Solicitation message (Model B). Here, the Source Layer-2 ID and Destination Layer-2 ID are used to send and receive the message, and the Discoverer Info and Relay Service Code can be included in the message.

[0175] - Source Layer-2 ID: 5G ProSe Remote-UE can select its own Source Layer-2 ID for 5G ProSe UE-to-Network Relay Discovery.

[0176] - Destination Layer-2 ID: The Destination Layer-2 ID for 5G ProSe UE-to-Network Relay Discovery can be selected based on a given scenario (see 3GPP TS 23.304 section 5.1.4.1).

[0177] - Discoverer Info: Can provide information about the discoverer user (e.g., user info ID).

[0178] - Target Info: Information about the target discoveree user (e.g., user info ID) can be provided.

[0179] - Relay Service Code: This may be information about the connection that the discoverer UE is interested in. The Relay Service Code can be set in the 5G ProSe Remote UE that is interested in the relevant connection service.

[0180] The following parameters can be used in the 5G ProSe UE-to-Network Relay Discovery Response message (Model B). Here, the Source Layer-2 ID and Destination Layer-2 ID are used to send and receive the message, and the Discoveree Info and Relay Service Code can be included in the message.

[0181] - Source Layer-2 ID: 5G ProSe UE-to-Network Relay can self-select the Source Layer-2 ID for 5G ProSe UE-to-Network Relay Discovery.

[0182] - Destination Layer-2 ID: Can be set to the Source Layer-2 ID of the received 5G ProSe UE-to-Network Relay Discovery Solicitation message.

[0183] - Relay Service Code: 5G ProSe UE-to-Network Relay can identify the connection service provided to the 5G ProSe Remote UE that matches the Relay Service Code of the corresponding Discovery Solicitation message.

[0184] - Discoveree Info: Can provide information about the discoveree (e.g. User Info ID).

[0185] The following parameters can be used in the Relay Discovery Additional Information message (using Model A) according to the procedure defined in the given scenario for 5G ProSe UE-to-Network Relay (3GPP TS 23.304 section 6.5.1.3). Here, the Source Layer-2 ID and the Destination Layer-2 ID are used to send and receive the message, and other parameters can be included in the message.

[0186] - Source Layer-2 ID: 5G ProSe UE-to-Network Relay can select its own Source Layer-2 ID to send the Relay Discovery Additional Information message.

[0187] - Destination Layer-2 ID: The Destination Layer-2 ID to which the Relay Discovery Additional Information message will be sent can be selected based on the settings defined in a given scenario (3GPP TS 23.304 section 5.1.4.1).

[0188] - Relay Service Code: This may be the Relay Service Code associated with the message. The Relay Service Code may be used to identify the security parameters required for the receiving UE to process the Discovery message.

[0189] - Announcer Info: You can provide information about the Announcer's users.

[0190] - Additional parameters: Additional parameters for 5G ProSe Layer-3 UE-to-Network Relay (if applicable) are defined in the given scenario (3GPP TS 23.304 section 5.8.3.2).

[0191] Below, a method for performing multi-hop based U2N relay communication based on the above-described discovery model B is described in detail.

[0192] Figure 14 is a diagram for explaining multi-hop based U2N relay communication.

[0193] In the existing Rel-17 SL U2N relay operation, <gnb>-<Relay UE> -<Remote UE> Technology development has been conducted for such connection relationships. However, in the future, for multi-hop U2N relay operation, technology development may be required for a structure in which the gNB and remote UE are connected through relay UEs of multiple hops. When passing through relay UEs of multiple hops, greater coverage extension can be achieved than in the case of existing U2N.

[0194] Hereinafter, methods for forwarding / broadcasting discovery messages for various cases in multi-hop (MP) U2N relay operation are described. In this case, broadcasting a discovery message may mean, unlike simple forwarding, re-generating one's own discovery message based on a discovery message received from another relay UE and then transmitting the re-generated discovery message by forwarding the received discovery message. If the broadcasting and / or forwarding operation of the discovery message is initiated by another relay UE (e.g., initiated through reception of a discovery message from another relay UE), the relay UE may modify the hop count value of the received discovery message and perform the broadcast / forwarding operation.

[0195] For convenience of explanation, as illustrated in FIG. 14, a relay UE directly connected to a gNB is defined as relay UE1, a relay UE (or intermediate relay UE) connected to relay UE1 is defined as relay UE2, a relay UE connected to relay UE2 is defined as relay UE3, etc. In this case, relay UE1 can be defined as Uu-SL relay UE, and relay UEs such as relay UE2 and 3 can be defined as SL-SL relay UEs.

[0196] Below, we describe in detail the initial connection setup procedure expected in MH-relay (Multi-hop relay) operation.

[0197] Initial connection procedure for multi-hop U2N relay operation

[0198] FIG. 15 and FIG. 16 are diagrams illustrating an initial connection setup procedure for U2N relay operation according to a given scenario.

[0199] Referring to FIG. 15, 1) the remote UE can select relay UE1 as a relay UE for U2N relay operation and then establish a PC5 connection (connection establishment) with the selected relay UE1.

[0200] 2) The remote UE may transmit an initialRRCSetupRequest message to the relay UE1 (or to the gNB via the relay UE1) for connection establishment with the gNB (or base station). The initialRRCSetupRequest message may include an ID of the remote UE (e.g., 5G S-temporary mobile subscriber identity; 5G-S-TMSI). If the relay UE1 receiving the initialRRCSetupRequest message is in RRC IDLE / INACTIVE state, the relay UE1 cannot (immediately) forward the initialRRCSetupRequest message to the gNB. Therefore, it may be expected that the initialRRCSetupRequest message will be stored in the relay UE1 until the relay UE1 becomes CONNECTED and can transmit the message to the gNB.

[0201] 3) When the relay UE1 is in the RRC IDLE / INACTIVE state, the relay UE1 may perform an operation for transitioning to the RRC CONNECTED state in order to transmit the initialRRCSetupRequest message. For example, the relay UE1 may transmit the RRCSetupRequest message to the gNB. The RRCSetupRequest message may include the ID of the relay UE1 (e.g., 5G-S-TMSI) and be transmitted. For example, the RRCSetupRequest message may be a message requesting RRC connection setup of the relay UE1.

[0202] 4) The gNB can send an RRCSetup message to the relay UE1. For example, when the gNB receives an RRCSetupRequest message from the relay UE1, it can send an RRCSetup message to the relay UE1 to set up the RRC connection of the relay UE1.

[0203] 5) When relay UE1 completes initial connection setup with gNB, relay UE1 can transmit a message to gNB through SUI including destination L2 ID (e.g., source L2 ID of remote UE from remote UE's perspective) and information requesting local ID for remote UE (e.g., local ID Request). For example, relay UE1 can provide gNB with destination L2 ID for remote UE and information requesting local ID for remote UE through SidelinkUEInformationNR message defined as in Table 5 below.

[0204] SL-TxResourceReqListCommRelay-r17 ::= SEQUENCE (SIZE (1..maxNrofSL-Dest-r16)) OF SL-TxResourceReqCommRelayInfo-r17SL-TxResourceReqCommRelayInfo-r17 ::= SEQUENCE {sl-RelayDRXConfig-r17 SL-TxResourceReq-v1700 OPTIONAL,sl-TxResourceReqCommRelay-r17 SL-TxResourceReqCommRelay-r17}SL-TxResourceReqCommRelay-r17 ::= CHOICE {sl-TxResourceReqL2U2N-Relay-r17 SL-TxResourceReqL2U2N-Relay-r17,sl-TxResourceReqL3U2N-Relay-r17 SL-TxResourceReq-r16}SL-TxResourceReqL2U2N-Relay-r17::= SEQUENCE {sl-DestinationIdentityL2U2N-r17 SL-DestinationIdentity-r16 OPTIONAL,sl-TxInterestedFreqListL2U2N-r17 SL-TxInterestedFreqList-r16,sl-TypeTxSyncListL2U2N-r17 SEQUENCE (SIZE (1..maxNrofFreqSL-r16)) OF SL-TypeTxSync-r16,sl-LocalID-Request-r17 ENUMERATED {true} OPTIONAL,sl-PagingIdentityRemoteUE-r17 SL-PagingIdentityRemoteUE-r17 OPTIONAL,sl-CapabilityInformationSidelink-r17 OCTET STRING OPTIONAL,...}

[0205] 6) The gNB can set a local ID (e.g., the local ID of the remote UE) for the destination ID reported from the relay UE1 via the RRCReconfiguration message. For example, the gNB can provide local ID information for the remote UE via the RRCReconfiguration message defined as in Table 6 below.

[0206] RRCReconfiguration-v1700-IEs ::= SEQUENCE {otherConfig-v1700 OtherConfig-v1700 OPTIONAL, -- Need Msl-L2RelayUE-Config-r17 SetupRelease { SL-L2RelayUE-Config-r17} OPTIONAL, -- Need Msl-L2RemoteUE-Config-r17 SetupRelease { SL-L2RemoteUE-Config-r17} OPTIONAL, -- Need MdedicatedPagingDelivery-r17 OCTET STRING (CONTAINING Paging) OPTIONAL, -- Cond PagingRelayneedForGapNCSG-ConfigNR-r17 SetupRelease {NeedForGapNCSG-ConfigNR-r17} OPTIONAL, -- Need MneedForGapNCSG-ConfigEUTRA-r17 SetupRelease {NeedForGapNCSG-ConfigEUTRA-r17} OPTIONAL, -- Need Mmusim-GapConfig-r17 SetupRelease {MUSIM-GapConfig-r17} OPTIONAL, -- Need Mul-GapFR2-Config-r17 SetupRelease { UL-GapFR2-Config-r17} OPTIONAL, -- Need Mscg-State-r17 ENUMERATED { deactivated} OPTIONAL, -- Need NappLayerMeasConfig-r17 AppLayerMeasConfig-r17 OPTIONAL, -- Need Mue-TxTEG-RequestUL-TDOA-Config-r17 SetupRelease {UE-TxTEG-RequestUL-TDOA-Config-r17} OPTIONAL, -- Need MnonCriticalExtension RRCReconfiguration-v1800-IEs OPTIONAL}

[0207] SL-L2RelayUE-Config-r17::= SEQUENCE {sl-RemoteUE-ToAddModList-r17 SEQUENCE (SIZE (1..maxNrofRemoteUE-r17)) OF SL-RemoteUE-ToAddMod-r17 OPTIONAL, -- Need Nsl-RemoteUE-ToReleaseList-r17 SEQUENCE (SIZE (1..maxNrofRemoteUE-r17)) OF SL-DestinationIdentity-r16 OPTIONAL, -- Need N...,[[sl-U2U-RemoteUE-ToAddModList-r18 SEQUENCE (SIZE (1..maxNrofSL-Dest-r16)) OF SL-U2U-RemoteUE-Config-r18 OPTIONAL, -- Need Nsl-U2U-RemoteUE-ToReleaseList-r18 SEQUENCE (SIZE (1..maxNrofSL-Dest-r16)) OF SL-DestinationIdentity-r16 OPTIONAL -- Need N]]}SL-RemoteUE-ToAddMod-r17 ::= SEQUENCE {sl-L2IdentityRemote-r17 SL-DestinationIdentity-r16,sl-SRAP-ConfigRelay-r17 SL-SRAP-Config-r17 OPTIONAL, -- Need M...}

[0208] 7) Relay UE1 may forward the initial RRCSetupReuquest message received from the remote UE (e.g., the RRCSetupReuquest message of the remote UE received in step '2)) to the gNB. At this time, relay UE1 may transmit to the gNB an SRAP (Sidelink Relay Adaptation Protocol) header including the L2 ID (or local ID) of the remote UE set in step '6)' and the bearer ID corresponding to SRB0 (e.g., "00000"). For example, relay UE1 may provide / forward the initial RRCSetupReuquest message (e.g., the initial RRCSetupReuquest message of the remote UE) to the gNB using a U2N SRAP data PDU format including an SRAP header as illustrated in FIG. 16.

[0209] 8) The gNB may send an RRCSetup message to the remote UE via relay UE1. The RRCSetup message may include the local ID of the remote UE and bearer information for SRB1 transmission. In this case, the local ID may be set to the same value as the local ID set by the gNB for the L2 ID of the remote UE in step "6)".

[0210] Meanwhile, since the gNB reports the L2 ID of the remote UE in step "6)" and sets the local ID for the reported L2 ID of the remote UE, the gNB can identify information about which local ID is set for which remote UE with which L2 ID value. At this time, when the relay UE1 forwards the initial RRCSetup message of the remote UE to the gNB, the relay UE1 can send the initial RRCSetup message with an SRAP header (including the local ID) added to the gNB. In this case, the gNB can set the C-RNTI value for the remote UE through the RRCSetup message, and the gNB can know all of the C-RNTI value, local ID value, and L2 ID value of the remote UE.

[0211] 9) The remote UE can send a SUI (SidelinkUEInformation) / UAI (UEAssistanceInformation) message (to the gNB) via relay UE1. The SUI / UAI message can include information for establishing a bearer for data transmission.

[0212] 10) The gNB can set up an end-to-end bearer (e2e) and SL-RLC channel for the remote UE to send data PDUs (Packet Data Units).

[0213] Below, we describe in detail how to perform the initial connection setup procedure for MH-relay operation by making full use of the given scenario (U2N relay of 3GPP Rel-17) described in FIGS. 15 and 16.

[0214] Figure 17 is a drawing illustrating a method for performing an initial connection setup procedure for MH-relay operation.

[0215] Referring to FIG. 17, 1) a remote UE can establish a PC5 connection (or SL connection / hop connection / direct connection) with a relay UE2 selected through a discovery procedure (for multi-hop based U2N relay communication).

[0216] 2) Relay UE2, which has established a PC5 connection with a remote UE, can select relay UE1 and establish a PC5 connection (or SL connection / hop connection / direct connection) with the selected relay UE1.

[0217] 3) The remote UE may transmit an initial RRCSetupRequest message to the relay UE2. The initial RRCSetupRequest message may be a message transmitted by the remote UE to establish an RRC connection with the gNB. At this time, the initial RRCSetupRequest message may be transmitted using a specified SL_RLC (and / or bearer) on the SRB (Signaling Radio Bearer) used by the remote UE. This is to inform the relay UE2 that the message received at the relay UE2 (e.g., the initial RRCSetupRequest message) is a message that should be transmitted to the relay UE1. A relay UE (e.g., relay UE2) connected via SL-SL may transmit the message received via the specified SL-RLC to the gNB via another relay UE (e.g., relay UE1) via the specified SL-RLC / bearer.

[0218] Alternatively, if the relay UE2 is in RRC_IDLE / INACTIVE state, the relay UE2 may store the initial RRCSetupRequest message received from the remote UE and perform an action to transition to RRC_CONNECTED state. Alternatively, if the relay UE2 is in RRC_CONNECTED state, the relay UE2 may forward the initial RRCSetupRequest message received from the remote UE toward the relay UE1.

[0219] 4) If relay UE2 is in RRC_IDLE / INACTIVE state, relay UE2 may need to perform connection setup operation to become RRC CONNECTED state. For example, relay UE2 may send relay UE1 an initial RRCSetupRequest message to establish its RRC connection. In this case, relay UE2 may also send its initial RRCSetupRequest message using a specific SL_RLC( / bearer). This is to enable relay UE1 to know that the initial RRCSetupRequest message of relay UE2 is the first RRCSetupRequest message that relay UE2 transmits to establish a connection with gNB. In this case, relay UE1 may need to distinguish whether the initial RRCSetupRequest message of relay UE2 is a message transmitted for SL-SL relay UE or a message transmitted for remote UE in order to distinguish it from the operation of existing Rel-17. For this purpose, the (initial) RRCSetupRequest message transmitted by the remote / relay UE may further include information about the UE type (e.g., whether it is a relay / remote UE, and if it is a relay UE, whether it is a UL-SL relay or a SL-SL relay). For example, relay UE1 may distinguish / identify whether the initial RRCSetupRequest message is for relay UE2 or a remote UE based on the UE type included in the received initial RRCSetupRequest message.

[0220] Alternatively, if relay UE1 is also in RRC_IDLE / INACTIVE state, relay UE1 can store the (initial) RRCSetupRequest message received from relay UE2 and perform actions for its RRC_CONNECTED. Alternatively, if relay UE1 is in RRC_CONNECTED state, relay UE1 can forward the (initial) RRCSetupRequest message received from relay UE2 toward gNB.

[0221] 5) When relay UE1 is in RRC_IDLE / INACTIVE state, relay UE1 needs to perform actions / procedures for RRC connection setup to transition to RRC CONNECTED state. Therefore, relay UE1 can send RRCSetupRequest message to gNB to enter RRC_CONNECTED state.

[0222] 6) The gNB may transmit an RRCSetup message for the RRC connection of the relay UE1 to the relay UE1. For example, if the relay UE1 in RRC_IDLE / INACTIVE state needs to transmit an RRCSetupRequest message for the RRC connection of the relay UE2 and / or remote UE to the gNB, the relay UE1 may transmit its RRCSetupRequest message to the gNB in ​​order to first transition to the RRC connected state (step '5'). In this case, the gNB may transmit the RRCSetupRequest message for the RRC connection of the relay UE1 to the relay UE1 based on the reception of the RRCSetupRequest message of the relay UE1.

[0223] 7) Relay UE1, which has entered RRC_CONNECTED state (e.g., by receiving an RRCSetupRequest message from gNB), may transmit a message, such as SUI, to gNB for requesting a destination L2 ID (e.g., (source) L2 ID of relay UE2) and a local ID for relay UE2. For example, the message may include information for requesting a destination L2 ID and a local ID for relay UE2. At this time, relay UE1 may have multiple other relay UEs / remote UEs connected to it. In this case, the relay UE may transmit a destination L2 ID and local ID request for multiple other relay UEs / remote UEs to gNB in ​​the form of a list (e.g., SUI, etc.)

[0224] Meanwhile, the SUI transmitted by the relay UE1 may also include type information about the UE type corresponding to the destination L2 ID. Currently, the SUI defined in a given scenario (3GPP Rel-17; e.g., single-hop based U2N relay communication) only defines the UE type of the entity transmitting the SUI, and does not define the UE type for the destination UE. Therefore, in the case of multi-hop-based, information about the UE type of the destination UE needs to be additionally defined for the SUI message. For example, in a given scenario (e.g., single-hop based U2N relay communication), if the UE type transmitting the SUI is a relay UE, the gNB can implicitly / comprehensively assume / guess that the UE corresponding to the destination L2 ID of the SUI is a remote UE. This is because the given scenario is defined only for single-hop based U2N relay. However, in the case of a multi-hop U2N relay where intermediate relay UEs also exist, it is difficult for the gNB to implicitly estimate / guess the type of the UE corresponding to the destination L2 ID as described above. For example, in MH-relay operation, the UE corresponding to the destination L2 ID of the SUI may be a relay UE or a remote UE. Therefore, when the L2 ID for another relay UE is reported as the destination L2 ID (e.g., the destination L2 ID of the SUI), the relay UE may also need to report information on what type of UE corresponds to the destination L2 ID. For example, UE type information related to the destination L2 ID may be additionally defined in the SUI message defined in Table 5. For example, an element may be additionally defined to indicate the UE type of sl-DestinationIdentityL2U2N-r17 in the parameter of SL-TXResourceReqL2U2N-Relay-r17 of the SUI message defined in Table 5.This is because the assigned values ​​of SRB1 and local ID set by the gNB may differ depending on the UE type. Alternatively, in order to inform the UE type corresponding to the destination L2 ID of the SUI, a method may be considered in which the UE corresponding to the destination L2 ID directly informs the UE connected to it through a PC5-RRC( / PC5-S) message, etc. Alternatively, the upper layer of the relay UE may inform the AS layer of the UE type for the destination L2 ID. This is because the upper layer may also know the destination UE type through the discovery and / or PC5 connection establishment process, etc.

[0225] 8) The gNB may set up a radio bearer and / or an RLC channel for transmitting a local ID and an SRB1 of the destination L2 ID reported by the relay UE1 (e.g., the L2 ID for the relay UE2). For example, the gNB may set up a local ID, a radio bearer, and RLC channels for the UE (e.g., the relay UE2) corresponding to the destination L2 ID based on the UE type information corresponding to the destination L2 ID included in the message received in step '7)'.

[0226] 9) Relay UE1 can forward the RRCSetupRequest message for RRC connection setup of relay UE2, which was received and stored from relay UE2, to gNB. At this time, relay UE1 attaches the local ID and bearer ID (i.e., “00000”) for relay UE2 configured by gNB to an SRAP header and transmits it to gNB. For example, relay UE1 can transmit an initial RRCSetupRequest message of relay UE2 to gNB with an SRAP header attached / added including the local ID and bearer ID (e.g., “00000”) for relay UE2 configured by gNB.

[0227] 10) The gNB may transmit an RRCSetup message (e.g., a message for RRC connection of relay UE2) to relay UE2 via relay UE1. At this time, the gNB may transmit a message with an SRAP header attached for relay UE2 to relay UE1, and relay UE1 may transmit only the RRCSetup message with the SRAP header removed from the message to relay UE2 (or to the remote UE) via a specified SL_RLC0( / bearer). This is because relay UE2 (or remote UE) does not know its own local ID value until it receives the first RRCSetup message (the local ID value is included in the initialRRCSetup message). Therefore, relay UE1 may remove the SRAP header from the message received from gNB and forward the message with the SRAP header removed to relay UE2.

[0228] 11) Relay UE2, which has completed RRC connection setup with gNB, can request gNB for destination L2 ID (e.g., (source) L2 ID of remote UE) and local ID for remote UE by transmitting message such as SUI. If relay UE2 is connected to multiple remote UEs, relay UE2 can request setting of local ID through list information for multiple remote UEs (e.g., in a similar manner to step '7').

[0229] 12) The gNB can allocate a local ID for the remote UE to the relay UE2 based on the SUI message received in '11)' and configure the remote UE for SRB0 ( / SRB 1) transmission.

[0230] 13) Since the SRB0( / SRB1) transmission of the remote UE (e.g., RRCSetupRequest / RRCSetup message) is transmitted to the gNB via relay UE2 and relay UE1, even if the relay UE1 transmits a message including SRAP header information (e.g., local ID, bearer ID) corresponding to the remote UE, the relay UE1 must be able to directly transmit a message including SRAP header information related to the remote UE (or, even if the relay UE1 transmits a message including SRAP header information corresponding to the remote UE, the relay UE1 must be able to transmit it). Therefore, the gNB must also configure the relay UE1 to transmit the SRAP header related to the remote UE to the appropriate SL_RLC( / bearer).

[0231] Meanwhile, in the case of a given scenario (single-hop U2N in 3GPP Rel-17), since it is a single-hop U2N operation, the following operations may be performed. For example, a UE acting as a relay UE may be configured through Sl-L2relayUE-Config in Table 7, but addition / modification of remote UEs may also be configured (sl-RemoteUE-ToAddModList). In this case, in order to indicate which remote UE the SRAP configuration is for, the SL-RemoteUE-ToAddMod element may be configured with the sl-L2IdentityRemote (e.g., L2 ID of the remote UE) value and the corresponding SRAP configuration (sl-SRAP-Configrelay) value.

[0232] However, when configuring a remote UE in the manner described above for relay UE1, the following problems may occur. For example, in the case of multi-hop, a problem may arise in that a relay UE directly connected to a gNB may not know the L2 ID of the remote UE. For example, relay UE1 may not know the L2 ID of the remote UE, and the local ID for the remote UE may also be a value transmitted through relay UE2. Therefore, it is necessary to configure relay UE1 so that it can recognize that the local ID for the remote UE is the local ID of SL-RLC( / bearer) transmitted to relay UE2. In addition, from the perspective of relay UE1, since the above-described setting (sl-RemoteUE-ToAddModList or Sl-L2relayUE-Config) is not a setting for the destination L2 ID reported by relay UE1 through its SUI (the content reported by relay UE1 through its SUI only contains information about relay UE2), it may be unclear what the above-described setting (e.g., sl-RemoteUE-ToAddModList or Sl-L2relayUE-Config) represents. For example, relay UE1 may be unclear what the setting represents in the case of the setting via Sl-L2relayUE-Config, since it is not a setting for the destination L2 ID reported by relay UE1 through its SUI. Therefore, additional setting or provision of information as follows may be required.

[0233] - Even when a message / data containing an SRAP header of a remote UE is transmitted to relay UE1, SL-RLC( / bearer) must be configured for transmission. For example, SL-RLC( / bearer) can be configured to forward / transmit a message / data containing an SRAP header of a remote UE to relay UE1.

[0234] - In this case, since the value is not included in the information about the L2 ID reported by the relay UE1 (e.g., the L2 ID of the remote UE) (e.g., the L2 ID of the SRAP header included in the above-described message is not the L2 ID reported by the relay UE1 in the SUI message), it can be indicated to the relay UE1 that the configuration for this is for MH-relay. Alternatively, it can be indicated for whom the current configuration information or the message (e.g., the message in which the above-described SRAP header is configured / included) is intended (whether it is information for the SL-SL relay UE, the remote UE, or the relay UE of which hop). For example, a message including an SRAP configuration can additionally include information about an L2 ID mapped to a local ID (e.g., the L2 ID of the relay UE2). For example, although the SRAP configuration is not for the purpose reported by relay UE1 (i.e., the L2 ID value), the relay UE1 may be instructed that the configuration is for another relay UE2 or remote UE other than relay UE2 connected to relay UE1. This instructing method may simply indicate that the operation is for an MH-relay UE, or may indicate which relay / remote UE the configuration is for.

[0235] - For example, if information about the SRAP header of a remote UE is set in relay UE1, this must be transmitted via relay UE2. Therefore, when setting information about the SRAP header for the remote UE, the destination L2 ID needs to be indicated as the L2 ID of the relay UE2, not the L2 ID of the remote UE. For example, if a message in which information about the SRAP header of the remote UE is set needs to be transmitted by relay UE1, the gNB needs to indicate to relay UE1 that the destination L2 ID of the message including the SRAP header is the L2 ID of the relay UE2, not the L2 ID of the remote UE, when setting information about the SRAP header for the remote UE.

[0236] 14) Relay UE2, which has completed RRC connection setup with gNB, can forward the RRCSetupRequest message for RRC connection setup of the remote UE, which it has received and stored from the remote UE, to gNB. At this time, relay UE2 can attach the SRAP header of the remote UE to the RRCSetupRequest message and transmit the RRCSetupRequest message with the SRAP header of the remote UE toward the base station (via another relay UE). Relay UE1 has received the RLC channel ( / bearer) set up for SRB1 transmission of the remote UE in '13)', and thus relay UE1 can forward the SRB1 message received from the remote UE to gNB.

[0237] 15) The RRCSetup message for establishing the RRC connection of the remote UE generated by the gNB can be transmitted to the remote UE via relay UE1 and relay UE2. The remote UE does not know its own local ID until it receives the initial RRCSetup message. Therefore, relay UE2 can remove the SRAP header of the RRCSetup message for the remote UE received from the gNB and only forward the RRCSetup message to the remote UE.

[0238] Meanwhile, the RRCSetupRequest message transmitted by the remote UE in step "1)" can be naturally replaced with the RRCReestablishmentRequest / RRCResumeRequest message. Alternatively, the proposed invention assumes a case where one remote UE and / or relay UE selects a relay UE for its SL connection. For example, the proposed invention assumes a case where the remote UE selects only one relay UE2 that can be connected to itself, and the relay UE2 selects relay UE1 that can be connected to the gNB.

[0239] In this way, the proposed invention can effectively apply the initial setup procedure to multi-hop U2N relay operation.

[0240] FIG. 18 is a diagram illustrating how a first relay UE performs an initial connection setup procedure for a multi-hop based U2N relay.

[0241] As described above, the first relay UE may be a relay UE capable of relaying data / message transmission / reception between the remote UE and the base station / gNB. For example, the first relay UE may be a relay UE capable of performing a multi-hop based U2N relay operation. In addition, the first relay UE may be a last relay UE (or relay UE1) directly connected to the base station / gNB in ​​the multi-hop based U2N relay. The first relay UE may forward / transmit a message (e.g., a message of the remote UE) delivered via an intermediate relay UE (e.g., relay UE2, relay UE3) to the base station / gNB. As illustrated in FIG. 17, the first relay UE may form an SL connection / PC5 connection with a second relay UE (or relay UE2) that has formed an SL connection / PC5 connection with the remote UE through a discovery procedure or the like. For example, the first relay UE may perform an initial connection setup procedure as illustrated in FIGS. 15 to 17.

[0242] Specifically, referring to FIG. 18, a first relay UE may receive a first message requesting RRC (radio resource control) connection establishment of a first UE (S181). Here, the first message requesting RRC connection establishment may be a message requesting RRC connection establishment that is initially performed after the discovery procedure as described above, and the first UE may be a remote UE related to U2N relay communication / operation or another relay UE (hereinafter, a second relay UE). For example, when a second relay UE in an RRC idle state or an RRC inactive state receives a message requesting RRC connection establishment from a remote UE, the first relay UE may receive a first message requesting RRC connection establishment of the second relay UE from the second relay UE. Alternatively, when the first relay UE is directly connected to a remote UE, the first relay UE may receive a first message requesting RRC connection establishment of the remote UE. Alternatively, the first message may be an RRCSetupRequest message as illustrated in FIG. 17, and may further include UE type information on whether the first UE is a relay UE or a remote UE.

[0243] Next, the first relay UE may transmit a second message to the base station, which includes information requesting allocation of a local identifier (ID) for the first UE based on the first message (S183). Meanwhile, if the first relay UE is in an RRC idle state or an RRC inactive state, the first relay UE may transmit a message requesting its RRC connection establishment to the base station prior to transmitting the second message, and may be switched to an RRC connected state with the base station by receiving an RRC connection establishment message from the base station. Thereafter, the first relay UE may transmit the second message to the base station. Here, the second message may be a SidelinkUEInformationNR (SUI) message in which a source ID for the first relay UE and a destination ID for the first UE are set. In this case, as described above, the SUI message may include not only UE type information corresponding to the source ID for the UE transmitting the message, but also UE type information corresponding to the destination ID of the SUI message. For example, based on the U2N relay being multi-hop based, the second message may further include type information of the first UE corresponding to the destination ID. As described above, in the case of multi-hop, unlike in the case of a single hop, the UE corresponding to the destination ID of the SUI may be a relay UE or a remote UE. For example, the first relay UE may transmit a second message to the base station including information requesting allocation of a local identifier (ID) for the first UE, a destination ID (e.g., an L2 ID for the first UE), and UE type information for the destination ID. In this case, the base station may identify whether the UE requiring allocation of the local ID is a relay UE or a remote UE based on the UE type information, and may allocate an appropriate local ID / radio bearer / RLC channel corresponding to the identified type.Thereafter, the first relay UE may receive a message responding to the second message (e.g., an RRCReconfiguration message) and may be assigned a local ID associated with the first UE through the message.

[0244] Next, the first relay UE may transmit / forward the first message further including an SRAP (Sidelink Relay Adaptation Protocol) header related to the first UE to the base station (S185). Alternatively, the first relay UE may transmit / forward the first message further including an SRAP header for SRB0 (Signaling Radio Bearer0) of the first UE to the base station. For example, when the first relay UE has been allocated a local ID for the first UE from the base station, the first relay UE may add an SRAP header related to the first UE to the first message received from the first UE, and transmit the first message with the added SRAP header to the base station. Here, the SRAP header related to the first UE may include a local ID and a bearer ID of the first UE.

[0245] Thereafter, the first relay UE may receive a third message from the base station for establishing an RRC connection to the first UE. For example, the third message may be an RRCSetup message, as illustrated in FIG. 17, to which an SRAP header associated with the first UE may be added. In this case, the first relay UE may remove the SRAP header associated with the first relay UE from the third message and transmit the RRCSetup message with the SRAP header removed to the first UE.

[0246] Meanwhile, the first relay UE may receive a fourth message having an SRAP (Sidelink Relay Adaptation Protocol) header that includes a local ID that is not assigned to the first UE (e.g., a local ID for a remote UE that is SL-connected with the first UE). For example, the fourth message may be a message that establishes an RRC connection between the first UE and the remote UE that is SL-connected. In this case, the first relay UE may not know the target corresponding to the local ID and may not know to which of the at least one intermediate relay UE connected to it the fourth message should be transmitted. In consideration of this, as described with reference to FIG. 17, the fourth message may additionally include mapping information for an L2 ID associated / mapped with the local ID (e.g., an L2 ID for an intermediate relay UE that is SL-connected with the remote UE), and the first relay UE may specify a relay UE to which the fourth message will be transmitted based on the mapping information.

[0247] FIG. 19 is a diagram illustrating how a base station performs an initial connection setup procedure for a multi-hop based U2N relay.

[0248] As described above, the base station can perform an initial connection setup procedure related to a multi-hop U2N relay operation formed by a plurality of relay UEs, including the first relay UE.

[0249] Specifically, referring to FIG. 19, the base station may receive a first message from the first relay UE, which includes information requesting allocation of a local identifier (ID) for the first UE (S191). Meanwhile, if the first relay UE is in an RRC idle state or an RRC inactive state, the base station may receive a message requesting RRC connection establishment of the first relay UE prior to receiving the first message, and transmit a corresponding RRC connection establishment message to the first relay UE to first form an RRC connection with the first relay UE.

[0250] Here, the first message may be a SidelinkUEInformationNR (SUI) message in which a source ID for the first relay UE and a destination ID for the first UE are set. In this case, as described above, the SUI message may include not only UE type information corresponding to the source ID for the UE transmitting the message, but also UE type information corresponding to the destination ID of the SUI message. For example, based on the U2N relay being based on multi-hop, the second message may further include type information of the first UE corresponding to the destination ID. For example, as described above, when the U2N relay is based on multi-hop, the UE corresponding to the destination ID of the SUI may be a relay UE or a remote UE. For example, the base station may receive a second message including information requesting allocation of a local identifier (ID) for the first UE from the first relay UE, a destination ID (e.g., an L2 ID for the first UE), and UE type information for the destination ID. In this case, the base station can identify whether the UE requiring allocation of the local ID is a relay UE or a remote UE based on the UE type information, and can allocate a local ID corresponding to the identified type.

[0251] Next, the base station can receive a second message from the relay UE, which further adds an SRAP (Sidelink Relay Adaptation Protocol) header related to the first UE to the message requesting RRC connection setup of the first UE (S193). For example, the base station can transmit a message for allocating a local ID for the first UE to the first relay UE based on the first message, and can receive a second message from the first relay UE, to which an SRAP header including information about the local ID is added. For example, the base station can receive an RRCSetupRequest message requesting RRC connection setup of the first UE and the SRAP header in the second message from the first relay UE.

[0252] Meanwhile, the base station may transmit a message for establishing an RRC connection to a remote UE directly connected to the first UE, which is an intermediate relay UE. In this case, since the first relay UE may not know the local ID associated with the remote UE, the base station may transmit a second message to the first relay UE, which further includes information about the mapping relationship between the local ID and the L2 ID of the first UE.

[0253] In this way, the proposed invention can effectively support the base station to assign an appropriate local ID by additionally providing the base station with information about the type of UE that requires the assignment of a local ID during the initial setup procedure of a multi-hop U2N relay. In addition, the proposed invention can support the relay UE to clearly identify an intermediate relay UE to which a message having a local ID that the relay UE does not recognize will be delivered by additionally providing a mapping relationship between the local ID and the L2 ID during the initial setup procedure of a multi-hop U2N relay.

[0254] Examples of communication systems to which the invention applies

[0255] Although not limited thereto, the various descriptions, functions, procedures, proposals, methods and / or operational flowcharts of the present invention disclosed in this document may be applied to various fields requiring wireless communication / connection (e.g., 5G) between devices.

[0256] Hereinafter, more specific examples will be provided with reference to the drawings. In the drawings / descriptions below, the same drawing reference numerals may represent identical or corresponding hardware blocks, software blocks, or functional blocks, unless otherwise described.

[0257] Figure 20 illustrates a communication system applied to the present invention.

[0258] Referring to FIG. 20, a communication system (1) applied to the present invention includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using a wireless access technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution)) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Things) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices, and can be implemented in the form of HMD (Head-Mounted Device), HUD (Head-Up Display) installed in a vehicle, television, smartphone, computer, wearable device, home appliance, digital signage, vehicle, robot, etc. Mobile devices can include smartphone, smart pad, wearable device (e.g., smart watch, smart glass), computer (e.g., laptop, etc.), etc. Home appliances can include TV, refrigerator, washing machine, etc. IoT devices can include sensors, smart meters, etc. For example, base stations and networks can also be implemented as wireless devices, and a specific wireless device (200a) can act as a base station / network node to other wireless devices.

[0259] Wireless devices (100a to 100f) can be connected to a network (300) via a base station (200). Artificial Intelligence (AI) technology can be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) via the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, etc. The wireless devices (100a to 100f) can communicate with each other via the base station (200) / network (300), but can also communicate directly (e.g., sidelink communication) without going through the base station / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to Everything) communication). In addition, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0260] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base stations (200), and base stations (200) / base stations (200). Here, wireless communication / connection can be achieved through various wireless access technologies (e.g., 5G NR) such as uplink / downlink communication (150a), sidelink communication (150b) (or, D2D communication), and communication between base stations (150c) (e.g., relay, IAB (Integrated Access Backhaul). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes can be performed based on various proposals of the present invention.

[0261] Examples of wireless devices to which the present invention is applied

[0262] Figure 21 illustrates a wireless device applicable to the present invention.

[0263] 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)} can correspond to {the wireless device (100x), the base station (200)} and / or {the wireless device (100x), the wireless device (100x)} of FIG. 20.

[0264] A first wireless device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memories (104) and / or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (102) may process information in the memory (104) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (106). In addition, the processor (102) may receive a wireless signal including second information / signal via the transceiver (106), and then store information obtained from signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / 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 via one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present invention, a wireless device may also mean a communication modem / circuit / chipset.

[0265] Specifically, the first wireless device or first relay UE (100) may include a processor (102) and a memory (104) connected to a transceiver (106). The memory (104) may include at least one program capable of performing operations related to the embodiments described in FIGS. 14 to 19.

[0266] A processor (102) may control a transceiver (106) to receive a first message requesting establishment of a radio resource control (RRC) connection for a first UE associated with a U2N (UE to Network) relay, and transmit a second message including information requesting allocation of a local identifier (ID) for the first UE to a base station based on the first message. Here, based on the U2N relay being multi-hop-based, the second message may further include type information of the first UE.

[0267] Alternatively, a processing device may be configured including a processor (102) and a memory (104). In this case, at least one processor; and at least one memory connected to the at least one processor and storing instructions, wherein the instructions, based on being executed by the at least one processor, cause the first relay UE to: receive a first message requesting establishment of a radio resource control (RRC) connection for a first UE associated with a U2N (UE to Network) relay, and transmit a second message to a base station including information requesting allocation of a local identifier (ID) for the first UE based on the first message. Here, based on the U2N relay being based on multi-hop, the second message may further include type information of the first UE.

[0268] The second wireless device (200) includes one or more processors (202), one or more memories (204), and may further include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memories (204) and / or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate third information / signals, and then transmit a wireless signal including the third information / signals via the transceivers (206). Furthermore, the processor (202) may receive a wireless signal including fourth information / signals via the transceivers (206), and then store information obtained from signal processing of the fourth information / signals in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may perform some or all of the processes controlled by the processor (202), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In the present invention, a wireless device may also mean a communication modem / circuit / chip.

[0269] Specifically, the second wireless device or base station (200) may include a processor (202) and a memory (204) connected to a transceiver (206). The memory (204) may include at least one program capable of performing operations related to the embodiments described in FIGS. 14 to 19.

[0270] The processor (202) controls the transceiver (206) to receive, from the first relay UE, a first message including information requesting allocation of a local identifier (ID) for a first UE associated with a U2N (UE to Network) relay, and to receive, through the first relay UE, a second message requesting establishment of a radio resource control (RRC) connection for the first UE. Here, based on the U2N relay being multi-hop-based, the second message may further include type information of the first UE.

[0271] Hereinafter, the hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed herein, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein.

[0272] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and executed by one or more processors (102, 202). The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0273] One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0274] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of this document, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of this document, from one or more other devices. For example, one or more transceivers (106, 206) can be connected to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein, via one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0275] Examples of wireless devices to which the present invention is applied

[0276] Figure 22 illustrates another example of a wireless device applicable to the present invention. The wireless device may be implemented in various forms depending on the use case / service (see Figure 20).

[0277] 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 / units, and / or modules. For example, the wireless device (100, 200) may include a communication unit (110), a control unit (120), a memory unit (130), and additional elements (140). The communication unit may include a communication circuit (112) and a transceiver(s) (114). For example, the communication circuit (112) may include one or more processors (102, 202) and / or one or more memories (104, 204) of FIG. 21. 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 the additional elements (140) and controls the overall operation of the wireless device. For example, the control unit (120) may control the electrical / mechanical operation of the wireless device based on the program / code / command / information stored in the memory unit (130). In addition, the control unit (120) may transmit information stored in the memory unit (130) to an external device (e.g., another communication device) via a wireless / wired interface through the communication unit (110), or store information received from an external device (e.g., another communication device) via a wireless / wired interface in the memory unit (130).

[0278] The additional element (140) may be configured in various ways depending on the type of the wireless device. For example, the additional element (140) may include at least one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 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 a financial device), a security device, a climate / environmental device, an AI server / device (Fig. 20, 400), a base station (Fig. 20, 200), a network node, etc. Wireless devices may be mobile or stationary depending on the use / service.

[0279] 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 some may be wirelessly connected via a communication unit (110). For example, within the wireless device (100, 200), the control unit (120) and the communication unit (110) may be wired, and the control unit (120) and a first unit (e.g., 130, 140) may be wirelessly connected via the communication unit (110). In addition, each element, component, unit / part, and / or module within the wireless device (100, 200) may further include one or more elements. For example, the control unit (120) may be composed of one or more processor sets. For example, the control unit (120) may be composed of a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory, and / or a combination thereof.

[0280] Examples of vehicles or autonomous vehicles to which the present invention is applied

[0281] Figure 23 illustrates a vehicle or autonomous vehicle applicable to the present invention. The vehicle or autonomous vehicle may be implemented as a mobile robot, car, train, manned / unmanned aerial vehicle (AV), ship, etc.

[0282] 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 a part of the communication unit (110). Blocks 110 / 130 / 140a to 140d correspond to blocks 110 / 130 / 140 of FIG. 22, respectively.

[0283] The communication unit (110) can transmit and receive signals (e.g., data, control signals, etc.) with external devices such as other vehicles, base stations (e.g., base stations, road side units, etc.), and servers. The control unit (120) can control elements of the vehicle or autonomous vehicle (100) to perform various operations. The control unit (120) can include an ECU (Electronic Control Unit). The drive unit (140a) can drive the vehicle or autonomous vehicle (100) on the ground. The drive unit (140a) can include an engine, a motor, a power train, wheels, brakes, a steering device, etc. The power supply unit (140b) supplies power to the vehicle or autonomous vehicle (100) and can include a wired / wireless charging circuit, a battery, etc. The sensor unit (140c) can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit (140c) may include an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, an incline sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / backward sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit (140d) may implement a technology for maintaining a driving lane, a technology for automatically controlling speed such as adaptive cruise control, a technology for automatically driving along a set path, a technology for automatically setting a path and driving when a goal is set, etc.

[0284] For example, the communication unit (110) can receive map data, traffic information data, etc. from an external server. The autonomous driving unit (140d) can generate an autonomous driving route and driving plan based on the acquired data. The control unit (120) can control the drive unit (140a) so that the vehicle or autonomous vehicle (100) moves along the autonomous driving route according to the driving plan (e.g., speed / direction control). During autonomous driving, the communication unit (110) can irregularly / periodically acquire the latest traffic information data from an external server and can acquire surrounding traffic information data from surrounding vehicles. In addition, during autonomous driving, the sensor unit (140c) can acquire vehicle status and surrounding environment information. The autonomous driving unit (140d) can update the autonomous driving route and driving plan based on newly acquired data / information. The communication unit (110) can transmit information regarding the vehicle location, autonomous driving route, driving plan, etc. to the external server. External servers can predict traffic information data in advance using AI technology or other technologies based on information collected from vehicles or autonomous vehicles, and provide the predicted traffic information data to the vehicles or autonomous vehicles.

[0285] Here, the wireless communication technology implemented in the wireless device (XXX, YYY) of the present specification may include not only LTE, NR, and 6G, but also Narrowband Internet of Things for low-power communication. At this time, for example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology, and may be implemented with standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless device (XXX, YYY) of the present specification may perform communication based on LTE-M technology. At this time, for example, LTE-M technology may be an example of LPWAN technology, and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology can be implemented by at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless device (XXX, YYY) of the present specification can include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) considering low-power communication, and is not limited to the above-described names. For example, ZigBee technology can create PAN (personal area networks) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and can be called by various names.

[0286] The embodiments described above are combinations of components and features of the present invention in a predetermined form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, it is also possible to form an embodiment 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 self-evident that claims that do not have an explicit citation relationship in the patent claims may be combined to form an embodiment or may be incorporated as a new claim through a post-application amendment.

[0287] In this document, embodiments of the present invention have been described primarily focusing on the signal transmission and reception relationship between a terminal and a base station. This transmission and reception relationship is equally / similarly extended to signal transmission and reception between a terminal and a relay or a base station and a relay. Certain operations described as being performed by a base station in this document may, in some cases, be performed by its upper node. That is, it is obvious that various operations performed for communication with a terminal in a network composed 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. In addition, the terminal may be replaced by terms such as UE (User Equipment), MS (Mobile Station), MSS (Mobile Subscriber Station).

[0288] Embodiments of the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of hardware implementation, an embodiment of the present invention may be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc.

[0289] When implemented via firmware or software, an embodiment of the present invention may be implemented in the form of modules, procedures, functions, etc. that perform the functions or operations described above. The software code may be stored in a memory unit and executed by a processor. The memory unit may be located within or outside the processor and may exchange data with the processor via various known means.

[0290] It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the scope of the invention. Therefore, the above detailed description should not be construed as limiting in any respect, but rather as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present invention are intended to be included within the scope of the present invention.

[0291] The embodiments of the present invention as described above can be applied to various mobile communication systems.< / gnb>

Claims

1. In a method using a first relay UE (User Equipment), A step of receiving a first message requesting RRC (radio resource control) connection establishment for a first UE associated with a U2N (UE to Network) relay; and A step of transmitting a second message to the base station, the second message including information requesting allocation of a local identifier for the first UE based on the first message; A method wherein the second message further includes type information of the first UE, based on the fact that the U2N relay is multi-hop based.

2. In paragraph 1, The second message is a SidelinkUEInformationNR message in which a source ID for the first relay UE and a destination ID for the first UE are set, A method, characterized in that the second message includes first type information about the source ID and second type information about the destination ID.

3. In paragraph 1, A method characterized in that it further comprises the step of transmitting the first message including an SRAP (Sidelink Relay Adaptation Protocol) header related to the first UE to the base station.

4. In paragraph 3, A method, characterized in that the SRAP header includes a local ID and a bearer ID of the first UE allocated by the base station.

5. In paragraph 3, A method characterized in that the first relay UE receives a third message for establishing an RRC connection to the first UE from the base station, and transmits a message with an SRAP header related to the first relay UE removed from the third message to the first UE.

6. In paragraph 1, Further comprising the step of receiving a fourth message with an SRAP (Sidelink Relay Adaptation Protocol) header including a local ID not assigned to the first UE; A method, characterized in that the first relay UE forwards the fourth message to the first UE based on the fourth message further including mapping information between the local ID and the ID for the first UE.

7. In paragraph 1, A method, characterized in that the first message further includes UE type information for the first UE.

8. In paragraph 1, Based on the first relay UE being in an RRC idle or RRC inactive state, the first relay UE further transmits a fourth message requesting the base station to establish an RRC connection of the first relay UE, A method characterized in that, based on a message for establishing an RRC connection to the first relay UE being received from the base station, the first relay UE forwards the first message to the base station.

9. In paragraph 1, The above first UE is an intermediate relay UE performing the U2N relay operation connected to the base station through the first relay UE, A method, characterized in that the first relay UE is a relay UE directly connected to the base station.

10. A computer-readable recording medium recording a program for performing the method described in paragraph 1.

11. In the first relay UE (User Equipment), RF (Radio Frequency) transmitter and receiver; and A processor connected to the RF transceiver, The processor controls the RF transceiver to receive a first message requesting RRC (radio resource control) connection setup for a first UE associated with a U2N (UE to Network) relay, and transmits a second message to a base station including information requesting allocation of a local identifier (ID) for the first UE based on the first message. A first relay UE, wherein the second message further includes type information of the first UE, based on the fact that the U2N relay is multi-hop based.

12. In paragraph 11, The second message is a SidelinkUEInformationNR message in which a source ID for the first relay UE and a destination ID for the first UE are set, A first relay UE, characterized in that the second message includes first type information about the source ID and second type information about the destination ID.

13. In a processing device controlling the first relay UE (User Equipment), at least one processor; and At least one memory connected to said at least one processor and storing instructions, said instructions being executed by said at least one processor, wherein said first relay UE: Receive a first message requesting RRC (radio resource control) connection setup for a first UE related to a U2N (UE to Network) relay, and transmit a second message including information requesting allocation of a local identifier (ID) for the first UE to a base station based on the first message; A processing device, wherein the second message further includes type information of the first UE, based on the U2N relay being multi-hop based.

14. In the method by the base station, A step of receiving a first message from a first relay UE, the first message including information requesting allocation of a local identifier (ID) for a first UE associated with a U2N (UE to Network) relay; and A step of receiving a second message requesting RRC (radio resource control) connection setup for the first UE through the first relay UE; A method wherein the second message further includes type information of the first UE, based on the fact that the U2N relay is multi-hop based.

15. At the base station, RF (Radio Frequency) transmitter and receiver; and A processor connected to the RF transceiver, The processor controls the RF transceiver to receive, from the first relay UE, a first message including information requesting allocation of a local identifier (ID) for a first UE associated with a U2N (UE to Network) relay, and receives, through the first relay UE, a second message requesting establishment of an RRC (radio resource control) connection for the first UE. A base station, wherein the second message further includes type information of the first UE, based on the fact that the U2N relay is multi-hop based.

Images