Method and apparatus for managing relay communication between two remote terminals by relay terminal in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. In the present disclosure, a method performed by a first terminal in a wireless communication system may comprise the steps of: transmitting a direct communication request message for a second terminal to a user equipment-to-user equipment (U2U) relay terminal based on sidelink radio bearer (SLRB) configuration information for relaying communication between the first terminal and the second terminal; performing a PC5 security configuration for direct communication with the second terminal; receiving a direct communication acceptance message for the second terminal from the U2U relay terminal; and performing direct communication with the second terminal through the U2U relay terminal.

Description

Technical Field

[0001] The present disclosure relates to a wireless communication system. More specifically, the present disclosure relates to a method and apparatus for configuring relay information based on a side link with a relay terminal in a wireless communication system, and an operation of a relay terminal and a terminal establishing a connection between two terminals. Background Art

[0002] 5G mobile communication technology defines a wide frequency band to realize high transmission rates and new services, and can be realized not only in "below 6 GHz" frequency bands such as 3.5 GHz, but also in "above 6 GHz" frequency bands called millimeter waves including 28 GHz and 39 GHz. In addition, it has been considered to realize 6G mobile communication technology (called super 5G system) in terahertz frequency bands (for example, 95 GHz to 3 THz frequency bands) in order to realize a transmission rate fifty times faster than 5G mobile communication technology and an ultra-low latency one-tenth of 5G mobile communication technology.

[0003] At the beginning of 5G mobile communication technology, in order to support services and meet performance requirements related to enhanced mobile broadband (eMBB), ultra-reliable low latency communication (URLLC) and massive machine type communication (mMTC), there is already ongoing standardization on beamforming and massive MIMO for mitigating radio wave path loss in mmWave and increasing radio wave transmission distance, dynamic operation of parameter sets (e.g., operating multiple subcarrier spacings) and time slot formats for efficient utilization of mmWave resources, initial access technology for supporting multi-beam transmission and broadband, definition and operation of BWP (bandwidth part), new channel coding methods such as LDPC (low-density parity check) codes for large-volume data transmission and polar codes for highly reliable transmission of control information, L2 pre-processing, and network slicing for providing dedicated networks tailored for specific services.

[0004] Currently, there are ongoing discussions on the improvement and performance enhancement of initial 5G mobile communication technologies in view of the services to be supported by 5G mobile communication technologies, and there has been physical layer standardization on technologies such as vehicle-to-everything (V2X) for assisting driving decisions of autonomous vehicles based on information about the position and status of a vehicle transmitted by the vehicle and for enhancing user convenience, New Radio Unlicensed (NR-U) for system operation intended to comply with various regulatory-related requirements within unlicensed frequency bands, NR UE energy saving, non-terrestrial network (NTN) as UE-satellite direct communication for guaranteeing coverage in areas where communication with terrestrial networks is not possible, and positioning.

[0005] In addition, in the field of radio interface architecture / protocol, there is already ongoing standardization on technologies such as Industrial Internet of Things (IIoT) that supports new services through interconnection and convergence with other industries, IAB (Integrated Access and Backhaul) that provides nodes for network service area expansion by supporting wireless backhaul links and access links in an integrated manner, mobility enhancements including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access (two-step RACH for NR) for simplifying the random access procedure. Standardization is also ongoing in the field of system architecture / services on 5G baseline architecture (e.g., service-based architecture or service-based interface) for combining network function virtualization (NFV) and software defined network (SDN) technologies, and mobile edge computing (MEC) for receiving services based on UE location.

[0006] If such a 5G mobile communication system is commercialized, the already exponentially growing number of connected devices will be connected to the communication network, and it is accordingly expected that enhanced functions and performance of the 5G mobile communication system and integrated operations of the connected devices will be necessary. To this end, new research is arranged on extended reality (XR) for effectively supporting augmented reality (AR), virtual reality (VR), mixed reality (MR), etc., 5G performance improvement and complexity reduction by utilizing artificial intelligence (AI) and machine learning (ML), AI service support, metaverse service support, and drone communication.

[0007] Furthermore, such development of 5G mobile communication systems will serve as the basis for developing not only new waveforms, full-dimensional MIMO (FD-MIMO), multi-antenna transmission technologies (such as array antennas and massive antennas) for securing terahertz band coverage for 6G mobile communication technology, metamaterial-based lenses and antennas for improving terahertz band signal coverage, high-dimensional spatial multiplexing technology using orbital angular momentum (OAM), and reconfigurable smart surfaces (RIS), but also full-duplex technology for improving frequency efficiency and improving system networks for 6G mobile communication technology, AI-based communication technology for achieving system optimization and internalizing end-to-end AI support functions by utilizing satellites and AI (artificial intelligence) from the design stage, and next-generation distributed computing technology for realizing services at a complexity level that exceeds the limits of UE operating capabilities by utilizing ultra-high-performance communication and computing resources.

[0008] In addition, device-to-device direct communication (sidelink communication) using the 5G communication system has been studied, and it is expected that the sidelink communication can be applied to, for example, vehicle communication (vehicle-to-everything, hereinafter referred to as "V2X") and public safety networks to provide various services to users.

[0009] In particular, there is a need for a sidelink relay utilization scheme that can support service coverage expansion, increased data transfer reliability, and reduced terminal power consumption. Summary of the invention

[0010] Technical issues

[0011] The disclosed embodiments are to provide an apparatus and method capable of effectively providing services in a wireless communication system.

[0012] The technical subject matter pursued in the present disclosure may not be limited to the above-mentioned technical subject matter, and other technical subject matter not mentioned may be clearly understood from the following description by those skilled in the art to which the present disclosure belongs.

[0013] Solution to the problem

[0014] According to an embodiment of the present disclosure, a method performed by a user equipment in a wireless communication system may include: identifying resources for sending a sidelink discovery message, identifying the sidelink discovery message to be sent, selecting a destination identifier corresponding to the sidelink discovery message, selecting a logical channel corresponding to the selected destination identifier, and allocating the identified resources to the logical channel.

[0015] Advantageous Effects of the Invention

[0016] The present disclosure provides an apparatus and method capable of effectively providing a service in a wireless communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1a is a diagram showing a wireless communication system according to an embodiment of the present disclosure;

[0018] Figure 1b is a diagram showing a wireless communication system according to an embodiment of the present disclosure;

[0019] Figure 2 is a diagram showing a configuration of a base station in a wireless communication system according to an embodiment of the present disclosure;

[0020] Figure 3 is a diagram showing a configuration of a terminal in a wireless communication system according to an embodiment of the present disclosure;

[0021] Figure 4 is a diagram showing a configuration of a communication unit in a wireless communication system according to an embodiment of the present disclosure;

[0022] Figure 5 is a diagram showing a structure of time-frequency resources of a wireless communication system according to an embodiment of the present disclosure;

[0023] Figure 6is a diagram showing a process of processing configuration information for transmitting and receiving signaling and data in a wireless communication system in which direct communication is performed between a terminal and a terminal;

[0024] Figure 7 is a diagram showing a process of processing configuration information for transmitting and receiving signaling and data in a wireless communication system in which a terminal is connected to a base station through a side link relay;

[0025] Figure 8 is a diagram illustrating a process of processing configuration information for relay transmission of signaling and data in a wireless communication system in which a terminal and another terminal perform communication through a side link relay according to an embodiment of the present disclosure;

[0026] Fig. 9 is a diagram illustrating processing of a discovery message for discovering a side link relay in a wireless communication system in which a terminal and another terminal perform communication through a side link relay according to an embodiment of the present disclosure;

[0027] Fig.10a is a diagram illustrating an operation of processing a side link relay discovery message transmission resource in a wireless communication system in which a terminal and another terminal perform communication through a side link relay according to an embodiment of the present disclosure;

[0028] Fig.10b is a diagram illustrating an operation of processing a side link relay discovery message transmission resource in a wireless communication system in which a terminal and another terminal perform communication through a side link relay according to an embodiment of the present disclosure;

[0029] Fig.10c is a diagram illustrating an operation of processing a side link relay discovery message transmission resource in a wireless communication system in which a terminal and another terminal perform communication through a side link relay according to an embodiment of the present disclosure;

[0030] Fig.11a is a diagram illustrating an operation of processing transmission of a side link relay discovery message in a wireless communication system in which a terminal and another terminal perform communication through a side link relay according to an embodiment of the present disclosure;

[0031] Fig.11b is a diagram illustrating an operation of processing transmission of a side link relay discovery message in a wireless communication system in which a terminal and another terminal perform communication through a side link relay according to an embodiment of the present disclosure;

[0032] Fig.11c is a diagram illustrating an operation of processing transmission of a side link relay discovery message in a wireless communication system in which a terminal and another terminal perform communication through a side link relay according to an embodiment of the present disclosure;

[0033] Fig.11dis a diagram illustrating an operation of processing transmission of a side link relay discovery message in a wireless communication system in which a terminal and another terminal perform communication through a side link relay according to an embodiment of the present disclosure;

[0034] Fig.11e is a diagram illustrating an operation of processing transmission of a side link relay discovery message in a wireless communication system in which a terminal and another terminal perform communication through a side link relay according to an embodiment of the present disclosure;

[0035] Fig.12 shows a signal flow between a sidelink relay and a base station processing sidelink relay configuration information in a wireless communication system in which a terminal and another terminal perform communication through the sidelink relay according to an embodiment of the present disclosure; and

[0036] Fig.13 A signal flow between a terminal and a base station processing sidelink relay configuration information in a wireless communication system in which the terminal and another terminal perform communication through a sidelink relay according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0037] Hereinafter, exemplary embodiments of the present disclosure will be described in detail in conjunction with the accompanying drawings. It should be noted that in the accompanying drawings, identical or similar elements are indicated by identical or similar reference numerals as much as possible. In addition, detailed descriptions of known functions or configurations that may make the subject matter of the present disclosure unnecessarily unclear will be omitted.

[0038] When describing the embodiments in the specification, descriptions related to technical contents known in the art and not directly related to the present disclosure will be omitted. Such omission of unnecessary descriptions is intended to prevent the main idea of ​​the present disclosure from being obscured and to convey the main idea more clearly.

[0039] For the same reason, in the accompanying drawings, some elements may be exaggerated, omitted or schematically shown. In addition, the size of each element does not fully reflect the actual size. In each of the accompanying drawings, the same or corresponding elements are assigned the same reference numerals.

[0040] By referring to the embodiments described in detail below in conjunction with the accompanying drawings, the advantages and features of the present disclosure and the ways to achieve them will be apparent. However, the present disclosure is not limited to the embodiments set forth below, but can be implemented in various different forms. The following embodiments are provided only to fully disclose the present disclosure and to notify the scope of the present disclosure to those skilled in the art, and the present disclosure is limited only by the scope of the appended claims. Throughout the specification, the same or similar reference numerals indicate the same or similar elements.

[0041] In this article, it will be understood that each box of the flowchart diagram and the combination of boxes in the flowchart diagram can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device create equipment for realizing the function specified in the flowchart box or box. These computer program instructions can also be stored in a computer-available or computer-readable memory, which can instruct the computer or other programmable data processing device to act in a particular way, so that the instructions stored in the computer-available or computer-readable memory produce an article of instruction equipment including the function specified in the flowchart box or box. The computer program instructions can also be loaded on a computer or other programmable data processing device, so that a series of operating steps are performed on a computer or other programmable device to produce a computer-implemented process, so that the instructions executed on a computer or other programmable device provide steps for realizing the function specified in the flowchart box or box.

[0042] In addition, each box in the flowchart diagram may represent a module, fragment or portion of code, which includes one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative embodiments, the functions marked in the box may not occur in order. For example, two boxes shown in succession may actually be executed substantially simultaneously, or the boxes may sometimes be executed in reverse order, depending on the functions involved.

[0043] As used in the embodiments of the present disclosure, "unit" refers to a software element or hardware element that performs a predetermined function, such as a field programmable gate array (FPGA) or an application-specific integrated circuit (ASIC). However, "unit" does not always have a meaning limited to software or hardware. "Unit" can be constructed to be stored in an addressable storage medium or to execute one or more processors. Therefore, "unit" includes, for example, software elements, object-oriented software elements, class elements or task elements, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays, and parameters. The elements and functions provided by the "unit" can be combined into a smaller number of elements or "units", or divided into a larger number of elements or "units". In addition, elements and "units" can be implemented as one or more CPUs in a reproduction device or a secure multimedia card. In addition, the "unit" in the embodiment can include one or more processors.

[0044] In the following description, for the convenience of description, terms for identifying access nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, terms referring to various identification information, etc. are illustratively used. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to subjects with equivalent technical meanings may also be used.

[0045] The following detailed description of the embodiments of the present disclosure is mainly directed to the new RAN (NR) as the radio access network and the packet core as the core network (5G system or 5G core network or next generation core (NG core)) in the 5G mobile communication standard specified by the Third Generation Partnership Project (3GPP) as a mobile communication standardization group, but based on the determination of those skilled in the art, the main ideas of the present disclosure can be applied to other communication systems with similar backgrounds through some modifications without significantly departing from the scope of the present disclosure.

[0046] In the 5G system, a network data collection and analysis function (NWDAF) may be defined to support network automation. The NWDAF is a network function for analyzing and providing data collected in the 5G network. The NWDAF may collect / store / analyze information from the 5G network and provide the results to an unspecified network function (NF), and the analysis results may be used independently in each NF.

[0047] In the following description, for the convenience of description, some terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) standard (a standard for 5G, NR, LTE or similar systems) may be used. However, the present disclosure is not limited to these terms and names and can be applied to systems conforming to other standards in the same manner.

[0048] In the following description, for the convenience of description, terms referring to signals, terms referring to channels, terms referring to control information, terms referring to network entities, terms referring to device elements, etc. are illustratively used. Therefore, the present disclosure is not limited by the terms used herein, and other terms referring to subjects with equivalent technical meanings may be used.

[0049] In the following description, a base station is an entity that allocates resources to a terminal, and may be at least one of a gNode B, an eNode B, a Node B, a base station (BS), a wireless access unit, a base station controller, and a node on a network. A terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function. However, they are merely examples thereof, and base stations and terminals are not limited to these examples. In the present disclosure, for the sake of convenience of description, the term "eNB" may be used interchangeably with the term "gNB". That is, a base station described as an "eNB" may refer to a "gNB". In the present disclosure, the term "terminal" may refer not only to mobile phones, NB-IoT devices, and sensors, but also to various wireless communication devices.

[0050] In particular, the present disclosure can be applied to 3GPP NR (5th generation mobile communication standard). In addition, the present disclosure can be applied to smart services based on 5G communication technology and IoT-related technology (e.g., smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail business, security and safety-related services, etc.). In the present disclosure, for the convenience of description, the term "eNB" can be used interchangeably with the term "gNB". That is, a base station described as "eNB" can refer to "gNB". In addition, the term "terminal" can refer not only to mobile phones, NB-IoT devices and sensors, but also to other wireless communication devices.

[0051] Wireless communication systems are evolving into broadband wireless communication systems for providing high-speed and high-quality packet data services using communication standards such as High Speed ​​Packet Access (HSPA) of 3GPP, LTE (Long Term Evolution or Evolved Universal Terrestrial Radio Access (E-UTRA)), Advanced LTE (LTE-A), LTE-Pro, High Speed ​​Packet Data (HRPD) of 3GPP2, Ultra Mobile Broadband (UMB), IEEE 802.16e, etc., as well as typical voice-based services.

[0052] As a typical example of a broadband wireless communication system, the LTE system adopts an orthogonal frequency division multiplexing (OFDM) scheme in the downlink (DL) and a single carrier frequency division multiple access (SC-FDMA) scheme in the uplink (UL). The uplink refers to a radio link via which a user equipment (UE) or a mobile station (MS) sends data or a control signal to a base station (BS) or an eNode B, and the downlink refers to a radio link via which a base station sends data or a control signal to a UE. The above-mentioned multiple access scheme separates the data or control information of each user by allocating and operating time-frequency resources for transmitting data or control information to each user to avoid overlapping with each other, that is, to establish orthogonality.

[0053] Since the 5G communication system as a post-LTE communication system must freely reflect various requirements of users, service providers, etc., it is necessary to support services that meet various requirements. Services considered in the 5G communication system include enhanced mobile broadband (eMBB) communication, massive machine type communication (mMTC), ultra-reliable low latency communication (URLLC), etc.

[0054] According to an embodiment, eMBB is intended to provide a higher data rate than that supported by existing LTE, LTE-A or LTE-Pro. For example, in a 5G communication system, eMBB must provide a peak data rate of 20Gbps in the downlink for a single base station and a peak data rate of 10Gbps in the uplink. In addition, the 5G communication system must provide an increased user-perceived data rate to the UE, as well as a maximum data rate. In order to meet such requirements, it may be necessary to improve the transmission / reception technology including further enhanced multiple-input multiple-output (MIMO) transmission technology. In addition, a frequency bandwidth greater than 20MHz can be used in a frequency band of 3 to 6GHz or 6GHz or higher to obtain the data rate required by the 5G communication system, instead of using a transmission bandwidth of up to 20MHz to send signals in the 2GHz frequency band used in LTE.

[0055] In addition, mMTC is being considered to support application services such as the Internet of Things (IoT) in a 5G communication system. mMTC may have requirements such as support for the connection of a large number of UEs in a cell, enhanced coverage of UEs, improved battery time, reduction in the cost of UEs, etc., in order to effectively provide the Internet of Things. Since the Internet of Things provides communication functions while being provided to various sensors and various devices, it must support a large number of UEs in a cell (e.g., 1,000,000 UEs / km2). In addition, a UE supporting mMTC may require wider coverage than coverage of other services provided by the 5G communication system because the UE may be located in a shadow area (such as a basement of a building) that is not covered by the cell due to the nature of the service. A UE supporting mMTC must be configured to be inexpensive and may require a very long battery life, such as 10 to 15 years, because it is difficult to frequently replace the battery of the UE.

[0056] Finally, URLLC, which is a cellular-based mission-critical wireless communication service, can be used for remote control of robots or machines, industrial automation, unmanned aerial vehicles, remote healthcare, emergency alerts, etc. Therefore, URLLC must provide communications with ultra-low latency and ultra-high reliability. For example, services supporting URLLC must meet an air interface delay of less than 0.5 ms, and may also require a packet error rate of 10-5 or less. Therefore, for services supporting URLLC, the 5G system must provide a shorter Transmit Time Interval (TTI) than other services, and may also require a design for assigning a large amount of resources in the frequency band in order to ensure the reliability of the communication link.

[0057] The above three services considered in the 5G communication system, namely eMBB, URLLC and mMTC, can be multiplexed and transmitted in a single system. In this case, different transmission / reception technologies and transmission / reception parameters can be used between services to meet the different requirements of each service. However, mMTC, URLLC and eMBB as described above are only examples of different service types, and the service types to which the present disclosure is applicable are not limited to those mentioned above.

[0058] In addition, in the following description of the embodiments of the present disclosure, LTE, LTE-A, LTE-Pro or NR systems will be described by way of example, but the embodiments of the present disclosure may be applied to other communication systems with similar backgrounds or channel types. In addition, based on the determination of those skilled in the art, the embodiments of the present disclosure may be applied to other communication systems with some modifications without significantly departing from the scope of the present disclosure.

[0059] Hereinafter, the operating principle of the present disclosure will be described in detail with reference to the accompanying drawings. The terms described below are defined in consideration of the functions in the present disclosure and may vary depending on the user, the user's intention or habit. Therefore, the definition of the terms should be made based on the content in the entire specification.

[0060] In the following description, the terms "physical channel" and "signal" may be used interchangeably with the terms "data" or "control signal". For example, the term "physical downlink shared channel (PDSCH)" refers to a physical channel through which data is transmitted, but PDSCH may also be used to refer to "data". That is, in the present disclosure, the expression "transmitting a physical channel" may be interpreted as having the same meaning as the expression "transmitting data or a signal through a physical channel".

[0061] In the following description of the present disclosure, upper layer signaling refers to a signal transmission scheme from a base station to a terminal via a downlink data channel of a physical layer or from a terminal to a base station via an uplink data channel of a physical layer. Upper layer signaling can also be understood as radio resource control (RRC) signaling or media access control (MAC) control element (CE).

[0062] Furthermore, as used in the present disclosure, the expression “greater than” or “less than” is used to determine whether a specific condition is satisfied or achieved, but this is intended only to illustrate an example and does not exclude “greater than or equal to” or “equal to or less than.” A condition indicated by the expression “greater than or equal to” may be replaced by a condition indicated by “greater than,” a condition indicated by the expression “equal to or less than” may be replaced by a condition indicated by “less than,” and a condition indicated by “greater than and equal to or less than” may be replaced by a condition indicated by “greater than and less than.”

[0063] In addition, the embodiments of the present disclosure will be described using terms adopted in some communication standards (eg, 3rd Generation Partnership Project (3GPP)), but they are for illustration purposes only. The embodiments of the present disclosure can be easily applied to other communication systems by modification.

[0064] In the following, the present disclosure relates to a method and apparatus, wherein, in a wireless communication system, a terminal processes a connection establishment with another terminal through a side link relay. The present disclosure relates to a method and apparatus, wherein, in a wireless communication system, a side link relay obtains configuration information required for relaying data / signaling between a terminal and another terminal. The present disclosure relates to a method and apparatus for processing a relay discovery message in a wireless communication system, the relay discovery message discovering a side link relay supporting a connection between a terminal and another terminal.

[0065] Specifically, the present disclosure provides a method, in which a terminal determines whether to perform a direct communication connection establishment process with another terminal through a side link relay, determines whether to obtain configuration information for sending a direct communication connection establishment message to other terminals or receiving a direct communication connection establishment message from other terminals through a side link relay, and obtains configuration information for sending and receiving direct communication connection establishment messages. The present disclosure provides a method, in which, in the case where the terminal needs to establish a connection with another terminal through a side link relay, the terminal determines whether the terminal needs to obtain a discovery message from the side link relay or send a discovery message for discovering the side link relay, and when the discovery message is obtained from the side link relay or the discovery message for discovering the side link relay is sent, the transmission of the side link discovery message or the reception of the side link discovery message is processed.

[0066] Embodiments of the present disclosure may enable a terminal to send data / signaling to or receive data / signaling from another terminal via sidelink relay so as to expand service coverage, increase reliability of data transmission and reception, and minimize battery usage of the terminal.

[0067] The present disclosure relates to a communication technology and a system thereof for integrating IoT technology with a fifth generation (5G) or quasi-5G communication system designed to support a higher data transfer rate than a fourth generation (4G) system such as a long term evolution (LTE) system. The present disclosure can be applied to smart services based on 5G communication technology and IoT-related technologies (e.g., smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail business, security and safety-related services, etc.).

[0068] The present disclosure may provide a method and device for processing signaling for discovering a sidelink relay in a wireless communication system so that a terminal establishes a connection with another terminal through the sidelink relay. In addition, the present disclosure may provide a method and device for processing configuration information for enabling a sidelink relay to relay data / signaling between a terminal and another terminal in a wireless communication system.

[0069] Advantageous effects obtainable from the present disclosure may not be limited to the above-mentioned effects, and other effects that are not mentioned may be clearly understood by those skilled in the art to which the present disclosure pertains from the following description.

[0070] Figure 1a is a diagram illustrating a wireless communication system according to an embodiment of the present disclosure.

[0071] Figure 1a An example of a base station 110, terminals 130 and 140, and a sidelink relay 120 capable of relaying data transmission and reception between the base station and the terminal as some nodes using a wireless channel in a wireless communication system is shown. According to an embodiment of the present disclosure, the sidelink relay may be a UE-to-network (U2N) relay. In addition, although Figure 1a Only one base station is shown, but other base stations identical to or similar to base station 110 may be further included, and more relays may be included. That is, Figure 1a The configuration of the wireless communication system shown in is an example and may further include Figure 1a Other elements not shown.

[0072] According to an embodiment of the present disclosure, the base station 110 may be a network infrastructure that provides wireless access to the terminals 130 and 140 and the relay 120. The base station 110 has coverage defined as a specific geographical area based on the distance at which the base station can send signals. The base station 110 may also be referred to as an "access point (AP)", "eNodeB (eNB)", "fifth generation (5G) node", "gNodeB (next generation Node B, gNB)", "radio point", "transmission / reception point (TRP)" or other terms having technical meanings equivalent thereto.

[0073] According to an embodiment of the present disclosure, the relay 120 is a device used by a user or a network infrastructure, and can perform communication with the base station 110 through a wireless channel. A link from the base station 110 toward the relay 120 is called a downlink (DL), and a link from the relay 120 toward the base station 110 may be called an uplink (UL). The base station 110 and the relay 120 may be connected via a Uu interface. An uplink (UL) may indicate a wireless link through which the relay 120 sends data or a control signal to the base station 110, and a downlink (DL) may indicate a wireless link through which the base station 110 sends data or a control signal to the relay 120.

[0074] In addition, the relay 120 may perform communication with the terminals 130 and 140 through a wireless channel. A link between the relay 120 and the terminal 130 and a link between the relay 120 and the terminal 140 are referred to as side links, and the side links may also be referred to as PC5 interfaces.

[0075] According to an embodiment of the present disclosure, each of the terminals 130 and 140 is a device used by a user, and may perform communication with the base station 110 through a wireless channel, or perform communication with a network through the relay 120 and a wireless channel.

[0076] In the present disclosure, each of the terminals 130 and 140 may perform communication with the relay 120 through a wireless channel. At least one of the terminals 130 and 140 may be operated without user participation. That is, at least one of the terminals 130 and 140 is a device that performs machine type communication (MTC) and may not be carried by a user. Each of the terminals 130 and 140 may be referred to as a "user equipment (UE)", "mobile station", "subscriber station", "remote terminal", "wireless terminal", "user equipment" or other terms having technical meanings equivalent thereto.

[0077] Figure 1b is a diagram illustrating a wireless communication system according to an embodiment of the present disclosure.

[0078] Figure 1bA wireless communication system is shown, which includes terminals 150 and 170 as some nodes using a wireless channel in the wireless communication system and a side link relay 160 capable of relaying data transmission and reception between the terminals. The side link relay 160 may be a UE-to-UE (U2U) relay. The wireless communication system is not limited to the above example. That is, Figure 1b The configuration of the wireless communication system shown in is an example and may further include Figure 1b Other elements not shown.

[0079] According to an embodiment of the present disclosure, the relay 160 may perform communication with the terminals 150 and 170 through a wireless channel. The link between the relay 160 and the terminal 150 and the link between the relay 160 and the terminal 170 are called side links, and the side links may also be called PC5 interfaces.

[0080] According to an embodiment of the present disclosure, each of the terminals 150 and 170 is a device used by a user, and can perform direct communication through a wireless channel, or perform communication with a counterpart terminal through a relay 160 and a wireless channel. The link between the terminal 150 and the terminal 170, the link between the terminal 150 and the relay 160, and the link between the terminal 170 and the relay 160 are called side links, and the side links may also be called PC5 interfaces.

[0081] In addition, at least one of the terminals 150 and 170 may be operated without user involvement. That is, at least one of the terminals 150 and 170 is a device that performs machine type communication (MTC) and may not be carried by a user. Each of the terminals 150 and 170 may be referred to as a "user equipment (UE)", "mobile station", "subscriber station", "remote terminal", "wireless terminal", "user equipment" or other terms having technical meanings equivalent thereto.

[0082] In the following description, an uplink or a downlink may be referred to as a Uu interface, and a side link may be referred to as PC5.

[0083] Figure 1a and Figure 1bThe base station 110, relays 120 and 160, and terminals 130, 140, 150, and 170 shown in the figure can send and receive wireless signals in a millimeter wave (mmWave) frequency band (e.g., 28 GHz, 30 GHz, 38 GHz, and 60 GHz). In order to improve channel gain, the base station 110, relays 120 and 160, and terminals 130, 140, 150, and 170 can perform beamforming. Herein, beamforming may include transmission beamforming and reception beamforming. That is, the base station 110, relays 120 and 160, and terminals 130, 140, 150, and 170 can provide directionality for transmission signals or reception signals. To this end, the base station 110, the relays 120 and 160, and the terminals 130, 140, 150, and 170 may select the service beams 112, 113, 121, 131, 141, 151, 161, and 171 through a beam search or beam management process. After the service beams 112, 113, 121, 131, 141, 151, 161, and 171 are selected, communication may be performed through resources having a quasi co-location (QCL) relationship with resources on which the service beams 112, 113, 121, 131, 141, 151, 161, and 171 have been transmitted.

[0084] According to an embodiment of the present disclosure, if a large-scale characteristic of a channel for which a symbol has been transmitted on a first antenna port can be inferred from a channel for which a symbol has been transmitted on a second antenna port, the first antenna port and the second antenna port can be evaluated to have a QCL relationship. For example, the large-scale characteristic may include at least one of delay spread, Doppler spread, Doppler shift, average gain, average delay, and spatial receiver parameters.

[0085] Figure 1a and 1b The terminals 130, 140, 150 and 170 shown in the figure can support vehicle communication. In the case of vehicle communication, in the LTE system, based on the device-to-device (D2D) communication structure, the standardization work of vehicle-to-everything (V2X) technology has been completed in 3GPP releases 14 and 15. Based on 5G NR, the standardization work of V2X technology has been completed in 3GPP release 16.

[0086] NR V2X supports end-to-end unicast communication, groupcast (or multicast) communication, and broadcast communication. In addition, unlike LTE V2X, which is designed to send and receive basic safety information required for road driving of vehicles, NR V2X is designed to provide further evolved services such as platooning, advanced driving, extended sensors, and remote driving. V2X services can be classified into basic safety services and advanced services.

[0087] Basic safety services may include detailed services such as car notification (Collaborative Awareness Message (CAM) or Basic Safety Message (BSM)) service, left turn notification service, forward collision warning service, emergency vehicle access notification service, forward obstacle warning service, intersection traffic light information service. V2X information may be sent and received using broadcast, unicast, or multicast transmission methods.

[0088] Compared with basic safety services, advanced services not only have enhanced quality of service (QoS) requirements, but also require methods for transmitting and receiving V2X information by using unicast and multicast transmission methods instead of broadcast transmission methods, so that V2X information can be sent and received in a specific vehicle group or between two vehicles. Advanced services may include detailed services such as convoy driving services, autonomous driving services, remote driving services, and extended sensor-based V2X services. In addition, NR V2X can support direct communication services between terminals in areas without network infrastructure in order to provide public safety services.

[0089] Hereinafter, a side link (SL) indicates a transmission / reception path of a signal between terminals or a transmission / reception path of a signal between a terminal and a relay and can be used together with the PC5 interface.

[0090] In the following, a base station is a subject that performs resource allocation for a terminal and a relay, and may be a base station that supports both V2X communication and general cellular communication, or a base station that supports only V2X communication. That is, a base station may mean an NR base station (e.g., gNB), an LTE base station (e.g., eNB), or a road side unit (RSU).

[0091] The terminal may include not only general user equipment and mobile stations, but also all of the following: vehicles supporting vehicle-to-vehicle (V2V) communication, handheld devices of vehicles or pedestrians (e.g., smart phones) supporting vehicle-to-pedestrian (V2P) communication, vehicles supporting vehicle-to-network (V2N) communication, or vehicles supporting communication between vehicles and transportation infrastructure (vehicle-to-infrastructure (V2I) communication), as well as roadside units (RSUs) equipped with terminal functions, RSUs equipped with base station functions, or RSUs equipped with some base station functions and some terminal functions.

[0092] In the present disclosure, a terminal may refer to a vehicle supporting vehicle-to-vehicle (V2V) communication, a vehicle or pedestrian's handheld device (e.g., a smart phone) supporting vehicle-to-pedestrian (V2P) communication, a vehicle supporting vehicle-to-network (V2N) communication, or a vehicle supporting vehicle-to-infrastructure (V2I) communication. A terminal may refer to a user device supporting device-to-device communication of a public safety network.

[0093] Furthermore, a terminal in the present disclosure may refer to a roadside unit (RSU) equipped with a terminal function, an RSU equipped with a base station function, or an RSU equipped with some base station functions and some terminal functions.

[0094] The relay in the present disclosure may refer to a vehicle supporting V2X communication or a user device supporting device-to-device communication of a public safety network. In addition, the relay in the present disclosure may refer to a device equipped with a terminal function, a device equipped with a base station function, or a device equipped with some terminal functions and some base station functions.

[0095] Figure 2 is a diagram showing a configuration of a base station in a wireless communication system according to an embodiment of the present disclosure.

[0096] Figure 2 The configuration shown in the figure may be understood as the configuration of the base station 110. The term "unit" or a term including a suffix "device", "machine", etc. used hereinafter may refer to a unit that processes at least one function or operation, and this may be embodied by hardware, software, or a combination of hardware and software.

[0097] refer to Figure 2 , the base station 110 may include a wireless communication unit 210, a backhaul communication unit 220, a storage unit 230, and a controller 240. However, the elements of the base station 110 are not limited to the examples shown. For example, the base station may also include more or fewer elements than the above elements. In addition, the wireless communication unit 210, the backhaul communication unit 220, the storage unit 230, and the controller 240 may be implemented in a single chip type. In addition, the controller 240 may include one or more processors.

[0098] The wireless communication unit 210 performs a function for sending or receiving a signal through a wireless channel. For example, the wireless communication unit 210 can perform a function of converting between a baseband signal and a bit stream according to the physical layer specification of the system. For example, when transmitting data, the wireless communication unit 210 can generate complex symbols by encoding and modulating the transmission bit stream. In addition, when receiving data, the wireless communication unit 210 can reconstruct the received bit stream by demodulating and decoding the baseband signal.

[0099] In addition, the wireless communication unit 210 up-converts the baseband signal into a radio frequency (RF) band signal, then transmits the converted RF band signal through the antenna, and down-converts the RF band signal received through the antenna into a baseband signal. To this end, the wireless communication unit 210 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), etc. In addition, the wireless communication unit 210 may include multiple transmission / reception paths. In addition, the wireless communication unit 210 may include at least one antenna array configured by a plurality of antenna elements.

[0100] In terms of hardware, the wireless communication unit 210 may be configured by a digital unit and an analog unit, and the analog unit may be configured by a plurality of sub-units according to operating power, operating frequency, etc. The digital unit may be implemented as at least one processor (eg, a digital signal processor (DSP)).

[0101] The wireless communication unit 210 transmits and receives signals as described above. Therefore, the whole or part of the wireless communication unit 210 may be referred to as a "transmitter", "receiver" or "transceiver". In addition, in the following description, transmission and reception performed through a wireless channel are used as meanings including the above-mentioned processing performed by the wireless communication unit 210.

[0102] The backhaul communication unit 220 may provide an interface for performing communication with other nodes within the network. That is, the backhaul communication unit 220 may convert a bit stream sent from the base station 110 to another node (e.g., another access node, another base station, a higher node, a core network, etc.) into a physical signal, and convert a physical signal received from another node into a bit stream.

[0103] The storage unit 230 may store data such as basic programs, application programs, and configuration information for the operation of the base station 110. The storage unit 230 may be configured by a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. The storage unit 230 may provide the stored data in response to a request of the controller 240.

[0104] The controller 240 may control the overall operation of the base station 110. For example, the controller 240 may send and receive signals through the wireless communication unit 210 or the backhaul communication unit 220. In addition, the controller 240 records data in the storage unit 230 and reads data from the storage unit 230. In addition, the controller 240 may perform the functions of the protocol stack required in the communication specification. According to another embodiment, the protocol stack may be included in the wireless communication unit 210. To this end, the controller 240 may include at least one processor. According to an embodiment, the controller 240 may control the base station 110 to perform operations according to an embodiment described later.

[0105] Figure 3 is a diagram showing a configuration of a terminal in a wireless communication system according to an embodiment of the present disclosure.

[0106] include Figure 3 The terminal of the configuration shown may correspond to Figure 1a The side link relay 120 in Figure 1a and Figure 1b Terminal 130, 140, 150 or 170 in.

[0107] Figure 3 The configuration shown in can be understood as the configuration of the side link relay 120 or the terminal 130, 140, 150 or 170. The term "... unit" or a term including a suffix "device", "machine", etc. used hereinafter may refer to a unit that processes at least one function or operation, and this may be embodied by hardware, software, or a combination of hardware and software.

[0108] refer to Figure 3 , the side link relay 120 and the terminal may each include a communication unit 310, a storage unit 320 and a controller 330. The elements of the terminal are not limited to the above examples. For example, the terminal may also include more or less elements than the above elements. In addition, the communication unit 310, the storage unit 320 and the controller 330 may be implemented in a single chip type. In addition, the controller 330 may include one or more processors.

[0109] The communication unit 310 performs a function for sending or receiving a signal through a wireless channel. For example, the communication unit 310 may perform a function of conversion between a baseband signal and a bit stream according to the physical layer specification of the system. For example, during data transmission, the communication unit 310 generates complex symbols by encoding and modulating the transmission bit stream. In addition, during data reception, the communication unit 310 may reconstruct the received bit stream by demodulating and decoding the baseband signal. In addition, the communication unit 310 may up-convert the baseband signal into an RF band signal, then transmit the converted RF band signal through an antenna, and down-convert the RF band signal received through the antenna into a baseband signal. For example, the communication unit 310 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like.

[0110] In addition, the communication unit 310 may include multiple transmission / reception paths. In addition, the communication unit 310 may include at least one antenna array including multiple antenna elements. In terms of hardware, the communication unit 310 may be configured by digital circuits and analog circuits (e.g., radio frequency integrated circuits (RFIC)). The digital circuits and analog circuits may be implemented as a single package. In addition, the communication unit 310 may include multiple RF chains. In addition, the communication unit 310 may perform beamforming.

[0111] The communication unit 310 can transmit and receive signals as described above. Therefore, the whole or part of the communication unit 310 may be referred to as a "transmitter", "receiver" or "transceiver". In addition, in the following description, transmission and reception performed through a wireless channel are used as the meaning including the above-mentioned processing performed by the communication unit 310.

[0112] The storage unit 320 may store data such as basic programs, applications, and configuration information for the operation of the terminal. The storage unit 320 may be configured by a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. The storage unit 320 provides stored data according to a request of the controller 330.

[0113] The controller 330 controls the overall operation of the terminal. For example, the controller 330 may send and receive signals through the communication unit 310. In addition, the controller 330 records data in the storage unit 320 and reads data from the storage unit 320. In addition, the controller 330 may perform the functions of the protocol stack required in the communication specification. To this end, the controller 330 may include at least one processor or microprocessor, or may be part of a processor. In addition, the controller 330 and a part of the communication unit 310 may be referred to as a communication processor (CP). According to an embodiment, the controller 330 may control the terminal to perform operations according to an embodiment described later.

[0114] Figure 4 is a diagram showing a configuration of a communication unit in a wireless communication system according to an embodiment of the present disclosure.

[0115] Figure 4 Shows Figure 2 The wireless communication unit 210 or Figure 3 An example of a specific configuration of the communication unit 310 is shown in FIG. Figure 4 The elements used to perform beamforming are shown in FIG. Figure 2 The wireless communication unit 210 or Figure 3 Part of the communication unit 310 in.

[0116] refer to Figure 4 , the wireless communication unit 210 or the communication unit 310 may include a coding and modulation unit 402 , a digital beamformer 404 , a plurality of transmission paths 406 - 1 to 406 -N, and an analog beamformer 408 .

[0117] The coding and modulation unit 402 may perform channel coding. For channel coding, at least one of a low density parity check (LDPC) code, a convolutional code, and a polar code may be used. The coding and modulation unit 402 generates modulation symbols by performing constellation mapping.

[0118] The digital beamformer 404 may perform beamforming of a digital signal (e.g., a modulation symbol). To this end, the digital beamformer 404 multiplies the modulation symbol by a beamforming weight. The beamforming weight is used to change the magnitude and phase of the signal and may be referred to as a "precoding matrix," "precoder," etc. The digital beamformer 404 may output the digitally beamformed modulation symbol to a plurality of transmission paths 406-1 to 406-N. According to a multiple-input multiple-output (MIMO) transmission technique, the modulation symbol may be multiplexed or the same modulation symbol may be provided to a plurality of transmission paths 406-1 to 406-N.

[0119] Multiple transmission paths 406-1 to 406-N can convert digital beamforming digital signals into analog signals. To this end, each of the multiple transmission paths 406-1 to 406-N may include an inverse fast Fourier transform (IFFT) calculator, a cyclic prefix (CP) inserter, a digital-to-analog converter (DAC), and an up-converter. The CP inserter is designed for an orthogonal frequency division multiplexing (OFDM) method and can be excluded when a different physical layer method (e.g., filter bank multi-carrier (FBMC)) is applied. That is, the multiple transmission paths 406-1 to 406-N can provide independent signal processing processes for the multiple streams generated by digital beamforming, respectively. However, according to the implementation method, parts of the elements of the multiple transmission paths 406-1 to 406-N may be shared.

[0120] The analog beamformer 408 can perform beamforming on the analog signal. To this end, the digital beamformer 404 can multiply the analog signal by a beamforming weight. The beamforming weight is used to change the size and phase of the signal. Specifically, the analog beamformer 408 can be configured differently according to the connection structure between the multiple transmission paths 406-1 to 406-N and the antenna. For example, each of the multiple transmission paths 406-1 to 406-N can be connected to an antenna array. As another example, the multiple transmission paths 406-1 to 406-N can be connected to an antenna array. As yet another example, the multiple transmission paths 406-1 to 406-N can be adaptively connected to an antenna array or two or more antenna arrays.

[0121] Figure 5 is a diagram showing the structure of time-frequency resources of a wireless communication system according to an embodiment of the present disclosure.

[0122] refer to Figure 5 , in the wireless resource region, the horizontal axis indicates the time domain, and the vertical axis indicates the frequency domain. The minimum transmission unit in the time domain is an OFDM symbol or a DFT-S-OFDM symbol, and Nsymb OFDM symbols or DFT-S-OFDM symbols 530 may be included in one slot 505. Unlike a slot, the length of a subframe in an NR system may be defined as 1.0 ms, and the length of a radio frame 500 may be defined as 10 ms. The minimum transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission band (transmission bandwidth) may include a total of N BW subcarriers 525. Such as N symb and N BW The specific value of may be applied variably depending on the system.

[0123] The basic unit of the time-frequency resource region is a resource element (RE) 510, which can be represented by an OFDM symbol index or a DFT-S-OFDM symbol index and a subcarrier index. A resource block (RB) 515 can be defined as N in the frequency domain. RB 520 consecutive subcarriers. Generally, the minimum transmission unit of data is an RB unit, and usually in an NR system, N symb is equal to 14 and N RB Equals 12.

[0124] like Figure 5 The structure of the time-frequency resources shown is applied to the Uu interface. Figure 5 The structure of the time-frequency resources shown can also be similarly applied to the side link.

[0125] According to an embodiment of the present disclosure, an operation process of a terminal (also referred to as a remote UE or source UE), a side link relay (also referred to as a relay or relay UE), and other terminals (also referred to as remote UE or destination UE) for processing a PC5 unicast connection establishment process between a terminal and other terminals for supporting data transmission and reception through a direct connection between the terminal and other terminals will be described. In addition, according to an embodiment of the present disclosure, a relay function configuration process of a side link relay for relaying data and signaling between a terminal and another terminal will be described. In addition, according to an embodiment of the present disclosure, a process for processing a discovery message sent and received to discover a side link relay for supporting data transmission and reception through a direct connection between a terminal and another terminal will be described.

[0126] According to an embodiment of the present disclosure, a sidelink relay may be authenticated for use in at least one or a combination of a specific service, a specific terminal, a specific sidelink flow, a specific sidelink bearer, a specific unicast link, a specific source identifier, and a specific destination (target) identifier.

[0127] According to an embodiment of the present disclosure, a side link relay can establish a direct connection with an authenticated terminal at the installation time. For example, while sending a relay discovery message, the side link relay can obtain a direct connection establishment request for the purpose of side link relay from the authenticated terminal, and establish a side link direct connection with the authenticated terminal. In addition, the side link relay can obtain a relay discovery request message (discovery solicitation message) from the authenticated terminal, and send a discovery message to the authenticated terminal to obtain a direct connection establishment request for the purpose of side link relay from the authenticated terminal, and establish a side link direct connection with the authenticated terminal.

[0128] When a PC5 direct link setup request message is received from an authenticated terminal, the side link relay may establish a side link direct connection with the authenticated terminal. The method of a PC5 direct connection setup request (PC5 direct link setup request) for a relay connection used by the side link relay and the terminal may include at least one or a combination of the following methods: including an "indication of a connection through a relay" in a general PC5 direct link setup request message, separately defining a "PC5 direct link setup message for the purpose of relaying", or configuring the use of a general PC5 direct link setup request message sent through a side link bearer (referred to as a side link radio bearer or SLRB) for the purpose of relaying. The present disclosure is not limited to this example.

[0129] Figure 6 is a diagram illustrating a process of processing configuration information for transmitting and receiving signaling and data in a wireless communication system in which direct communication is performed between UEs.

[0130] refer to Figure 6 UE1 600 and UE2 650 are UEs capable of establishing a direct connection via a side link interface and transmitting and receiving data and signaling through the direct connection. In operation 601, UE1 600 may transmit a direct communication request message to establish a direct connection with UE2 650.

[0131] When receiving the direct communication request message of operation 601 , UE2 650 may perform PC5 security configuration procedures, such as side link authentication and encryption key configuration, with UE1 600 in operation 602 for establishing a direct connection with UE1 600 .

[0132] When it is determined that the process for establishing the direct connection between UE1 600 and UE2 650 , such as side link authentication and encryption key configuration, has been normally performed, in operation 603 , UE2 650 may transmit a direct communication accept message to UE1 600 .

[0133] UE1 600 and UE2 650 may perform a subsequent procedure for establishing a direct connection, and in operation 606, signaling for exchanging sidelink UE capability information may be exchanged in the RRC layer of UE1 600 and UE2 650. In operation 606, in the RRC layer of UE1 600 and UE2 650, signaling for exchanging configuration information about a sidelink radio bearer (SLRB) for data transmission and reception may be exchanged.

[0134] The sidelink signaling radio bearer corresponding to the signaling sent and received between UE1 600 and UE2 650 in operations 601 to 606 corresponds to SL-SRB0, SL-SRB1, SL-SRB2 or SL-SRB3, and configuration information about SL-SRB0, SL-SRB1, SL-SRB2 and SL-SRB3 can be stored in UE1 600 and UE2 650 as a specified configuration.

[0135] The method of obtaining configuration information on a sidelink data radio bearer (SL-DRB) corresponding to data in operation 606 by the UE1 600 and the UE2 650 may be explained through three examples as shown in [Table 1].

[0136] [Table 1]

[0137]

[0138] If UE1 600 or UE2 650 is a transmitting UE, UE1 600 or UE2 650 can obtain configuration information about the sidelink data radio bearer of the QoS flow corresponding to the data to be sent through one of the three methods in [Table 1], and in operation 606, the SLRB configuration information about the QoS flow can be transmitted to UE2 650 or UE1 600 corresponding to the receiving UE through RRC layer signaling.

[0139] The SLRB configuration information (limited to only RX SLRB configuration information) about the QoS flow of the data to be applied by the receiving UE when performing reception can be determined by the receiving UE itself. UE1 600 or UE2 650 can apply the SLRB configuration information about the data configured in operation 606 to send and receive data in operation 607.

[0140] In a case where the UE performs a connection with a base station through a three-layer sidelink relay (Layer 3 U2N sidelink relay), the specified SLRB configuration may be applied to SL-SRB0, SL-SRB1, SL-SRB2, and SL-SRB3 used when establishing a sidelink unicast connection between the UE and the sidelink relay.

[0141] In a case where the UE establishes a sidelink unicast connection between the UE and the sidelink relay when the UE is connected to another UE via the sidelink relay, the specified SLRB configuration may be applied to signaling radio bearers (SL-SRB0, SL-SRB1, SL-SRB2, and SL-SRB3) between the UE and the sidelink relay.

[0142] Figure 7 is a diagram illustrating a process of processing configuration information for transmitting and receiving signaling and data in a wireless communication system in which a UE is connected to a base station through a side link relay.

[0143] refer to Figure 7 , UE 700 cannot process the RRC connection establishment procedure with base station 760 through direct connection, and thus can send and receive RRC signaling required for RRC connection establishment by using side link signaling with side link relay 750. Figure 7 In the embodiment of the present invention, the sidelink relay 750 may correspond to a two-layer sidelink relay (layer 2 U2N sidelink relay). To this end, in operation 701, the UE 700 and the sidelink relay 750 may establish a sidelink direct connection and configure a sidelink radio bearer (referred to as PC5 SLRB) through which RRC signaling required for RRC connection establishment with the base station 760 is transmitted and received.

[0144] When the RRCSetupRequest message is sent in operation 702, the UE 700 may apply the PC5 SLRB configuration, and at this time, the specified SLRB configuration may be applied. The sidelink relay 760 may receive the RRCSetupRequest message from the UE 700 through the specified SLRB configuration corresponding to the RRCSetupRequest message, and notify the base station 760 that the UE 700 is attempting RRC connection establishment through the sidelink relay 750.

[0145] The base station 760 can configure a dedicated RRC message including Uu radio bearer and SLRB configuration for the sidelink relay 750 to perform relay transmission of the RRCSetupRequest message and subsequent messages (RRCSetup, RRCSetupComplete, SecurityModeCommand, SecurityModeComplete, RRCReconfiguration, and RRCReconfigurationComplete) of the UE 700, and send the dedicated RRC message to the sidelink relay 750.

[0146] The base station 760 may configure a dedicated RRC message including SLRB configuration of an RRCSetupComplete message for the UE 700 and subsequent RRC messages (SecurityModeComplete and RRCReconfigurationComplete) that the UE 700 may send to the base station 760 through the sidelink relay 750 , and send the dedicated RRC message to the UE 700 .

[0147] The base station 760 may configure the SLRB configuration for the UE 700 to send the UE's data via the sidelink relay 750, and send the SLRB configuration to the UE 700 via a dedicated RRC message, and may configure the SLRB configuration and Uu radio bearer configuration for relay transmission of the UE's data via the sidelink relay 750, and send the configuration to the sidelink relay 750 via a dedicated RRC message.

[0148] The base station 760 may configure a SLRB configuration for transmitting data of the base station to be received by the UE 700 through the sidelink relay 750, and transmit the SLRB configuration to the sidelink relay 750 and the UE 700 through a dedicated RRC message.

[0149] Next, refer to Figure 8 , the process of establishing a sidelink unicast connection between a UE and a sidelink relay through the sidelink relay, establishing a sidelink unicast connection between the sidelink relay and other UEs, and establishing a sidelink unicast connection between the UE and other UEs will be described when a direct connection is established between the UE and another UE through a sidelink relay and signaling and data are sent and received.

[0150] Figure 8 is a diagram illustrating a process of processing configuration information for relay transmission of signaling and data in a wireless communication system in which a UE and another UE perform communication through a sidelink relay according to an embodiment of the present disclosure.

[0151] refer to Figure 8 , UE1 800 may determine whether a direct connection with UE2 870 can be established, and determine whether a side link relay 860 capable of supporting a direct connection with UE2 870 is found.

[0152] In operation 801, UE1 800 may perform a relay discovery procedure. In operation 801, UE1 800 may use a procedure of sending a relay discovery request message for discovering a side link relay capable of supporting a direct connection with UE2 870 and receiving a relay discovery message from the side link relay. Alternatively, in operation 801, UE1 800 may use a procedure of monitoring a relay discovery message according to a side link relay capable of supporting a direct connection with UE2 870.

[0153] In operation 802, the sidelink relay 860 may use a process of sending a relay discovery message for discovering UE2 870 with which UE1 800 is to establish a direct connection. Alternatively, in operation 802, the sidelink relay 860 may use a process of monitoring a relay discovery request message sent by UE2 870 with which UE1 800 is to establish a direct connection and sending a relay discovery message to UE2 870.

[0154] When it is determined that a direct connection with UE2 870 through the sidelink relay 860 is establishable, in operation 803, UE1 800 may perform a unicast connection procedure with the sidelink relay 860. When it is determined that a direct connection with UE1 800 through the sidelink relay 860 is establishable, in operation 804, UE2 870 may perform a unicast connection procedure with the sidelink relay 860.

[0155] You can execute Figure 6 Operations 601 to 606 are performed to establish a sidelink unicast connection between UE1 800 and the sidelink relay 860 and a sidelink unicast connection between the sidelink relay 860 and UE2 870. However, the SLRB configuration for data transmission and reception (i.e., the configuration of the SL-DRB in operation 606) may be omitted. The specified SLRB configuration may be applied to the SLRB (SL-SRB0, SL-SRB1, SL-SRB2, or SL-SRB3) for sidelink signaling transmitted and received during the unicast connection establishment process in operations 803 and 804.

[0156] UE1 800 and UE2 870 may establish an end-to-end unicast connection separately from the unicast connection of the sidelink relay 860. The end-to-end unicast connection may start with a process in which UE1 800 transmits a direct communication request message to UE2 870 through relay transmission of the sidelink relay 860 (operations 807 and 808).

[0157] UE1 800 and UE2 870 may perform a PC5 security procedure of processing sidelink authentication and encryption key configuration through relay transmission of the sidelink relay 860 (operation 809 ).

[0158] When it is determined that the sidelink security process has been normally performed, UE2 870 may perform a process of sending a direct communication acceptance message to UE1 800 through relay transmission of the sidelink relay 860 (operations 810 and 811). Figure 8Although not shown in the figure, when it is necessary to exchange the side link UE capability information between UE1 800 and UE2 870, the side link UE capability messages of UE1 800 and UE2 870 may be sent and received through the relay transmission of the side link relay 860. Figure 8 As shown in FIG. 8 , the RRC configuration message between UE1 800 and UE2 870 may be sent and received via relay transmission of the sidelink relay 860 .

[0159] UE1 800 and UE2 870 may transmit their own data to the corresponding UE through the relay transmission of the sidelink relay 860, and receive the data of the corresponding UE through the relay transmission of the sidelink relay 860 (operation 812). The end-to-end unicast connection may also start from a process in which UE2 870 first transmits a direct communication request message to UE1 800 through the relay transmission of the sidelink relay 860.

[0160] UE1 800, UE2 870, and sidelink relay 860 are required to obtain the end-to-end unicast connection establishment message sent and received between the two UEs and the sidelink radio bearer configuration information corresponding to the data of the two UEs through the relay transmission of the sidelink relay 860. The sidelink radio bearer configuration information may correspond to, for example, SLRB configuration information, which is applied to UE1 800 to send the direct communication request message of operation 807 to the sidelink relay 860 and to the sidelink relay 860 to receive the direct communication request message from UE1 800. In addition, the sidelink radio bearer configuration information may correspond to SLRB configuration information, which is applied to UE2 870 to send the direct communication acceptance message of operation 810 to the sidelink relay 869 and to the sidelink relay 860 to receive the direct communication acceptance message from UE2 870. In addition, the sidelink radio bearer configuration information may correspond to SLRB configuration information applied to UE1 800 to transmit and receive data of UE1 between UE1 800 and the sidelink relay 860 when UE1 800 transmits the data of UE1 to UE2 870 in operation 812 .

[0161] In operation 805, UE1 800 and the sidelink relay 860 may obtain SLRB configuration information for the purpose of relaying. In operation 806, UE2 870 and the sidelink relay 860 may obtain SLRB configuration information for the purpose of relaying. Figure 8 The time points of operation 805 and operation 806 shown in FIG. 8 may be an embodiment. That is, according to the method of obtaining the SLRB configuration for the purpose of relaying or the U2U relay type (layer 3 relay or layer 2 relay), in Figure 8After the time shown (eg, after operation 811 ) the operations may be performed.

[0162] A method of obtaining SLRB configuration information for the purpose of relaying according to a layer 2 U2U relay type is shown in the following [Table 2].

[0163] [Table 2]

[0164]

[0165] [Table 3] shows an example of a case where SLRB configuration information for the purpose of relay transmission is configured as a dedicated SLRB configuration.

[0166] [Table 3]

[0167]

[0168]

[0169]

[0170] [Table 4] shows an example of a case where SLRB configuration information for the purpose of relay transmission is configured as a specified configuration.

[0171] [Table 4]

[0172]

[0173] A method of obtaining SLRB configuration information for the purpose of relaying according to a layer 3 U2U relay type is shown in the following [Table 5].

[0174] [Table 5]

[0175]

[0176] [Table 6] shows an example of a case where SLRB configuration information for the purpose of relay transmission is configured as a dedicated SLRB configuration.

[0177] [Table 6]

[0178]

[0179] [Table 7] shows an example of a case where SLRB configuration information for the purpose of relay transmission is configured as a specified configuration.

[0180] [Table 7]

[0181]

[0182] Next, refer to Fig. 9 , will be described in Figure 8The side link relay discovery message sent in operation 801 and operation 802.

[0183] Fig. 9 is a diagram illustrating processing of a discovery message for discovering a side link relay in a wireless communication system in which a UE and another UE perform communication through the side link relay according to an embodiment of the present disclosure.

[0184] The sidelink discovery message used in U2U relay (layer 3 U2U relay or layer 2 U2U relay) can have Fig. 9 The protocol stack configured in layers 900 to 904 in the side link discovery layer 904. The side link discovery message can be configured in the discovery layer 904.

[0185] The PDCP data PDU format for the sidelink discovery message used in the U2U relay may be configured as format 905. The logical channel identifier through which the sidelink discovery message used in the U2U relay is transmitted may be configured as 0, which is the same as the logical channel identifier through which the U2N relay discovery message or the D2D direct discovery message is transmitted. The present disclosure is not limited to the above example, and the logical channel identifier through which the sidelink discovery message used in the U2U relay is transmitted may be configured to have a value different from the value of the logical channel identifier through which the U2N relay discovery message or the D2D direct discovery message is transmitted.

[0186] A method of configuring an SDU type of a side link discovery message used in U2U relay in format 905 and a method of configuring a logical channel identifier of a side link discovery message used in U2U relay are shown in [Table 8].

[0187] [Table 8]

[0188]

[0189] In a wireless communication system using U2U relay, both mode 1 in which a base station schedules transmission resources and mode 2 in which a transmission UE directly selects transmission resources may be applied as transmission resource allocation modes applied to a UE (source UE or destination UE) and a sidelink relay. The UE (source UE or destination UE) and the sidelink relay may perform operations of measuring and reporting a congestion busy ratio (CBR) of a transmission resource pool according to a configuration of the base station, and the transmission resource pool in which the CBR measurement and reporting is configured may correspond to a sidelink discovery dedicated resource pool (including a U2U discovery dedicated resource pool) or a general sidelink resource pool.

[0190] Next, we will refer to Figures 10a to 10c A method of selecting a transmission resource pool and a transmission resource in Mode 2 in which a transmission UE directly selects a transmission resource in a wireless communication system using a U2U relay is described. Figures 10a to 10c The present invention is an embodiment of a method for selecting transmission resources and configuring a transmission resource pool for a U2U relay discovery message.

[0191] Fig.10a This may correspond to a case where a separate transmission resource pool may be configured for transmission of a sidelink discovery message (i.e., transmission of a U2U relay discovery message, a U2N relay discovery message, and a D2D direct discovery message). If a separate transmission resource pool for the purpose of sidelink discovery message transmission is not configured, a transmission resource pool for the purpose of general sidelink transmission may be configured. Therefore, regardless of any sidelink discovery message transmission, the transmission resource pool for the purpose of general sidelink transmission may be used to send the sidelink discovery message.

[0192] Fig.10b This may correspond to a case where a separate transmission resource pool may be configured for transmission of a U2U relay discovery message. If a separate transmission resource pool for U2U relay discovery message transmission is not configured, a transmission resource pool for the purpose of general sidelink transmission is configured. Therefore, the transmission resource pool for the purpose of general sidelink transmission may be used to send a U2U relay discovery message.

[0193] exist Fig.10c In the present invention, if a separate transmission resource pool for U2U relay discovery message transmission is not configured, and a separate transmission resource pool for transmission of U2N relay discovery message or D2D direct discovery message is configured, the resource pool configured for transmission of different discovery messages can be used to send the U2U relay discovery message.

[0194] If in Figures 10a to 10c If a medium power saving option is configured for a transmission resource pool (partial sensing, full sensing, continuous partial sensing, non-continuous partial sensing, random selection, etc.), then when the UE selects a transmission resource or a transmission resource pool for U2U relay discovery message transmission, the UE may apply the power saving option configured for the transmission resource pool.

[0195] Fig.10a is a diagram illustrating an operation of processing a sidelink relay discovery message transmission resource in a wireless communication system in which a UE and another UE perform communication through a sidelink relay according to an embodiment of the present disclosure.

[0196] refer to Fig.10aIn operation 1000, the UE may determine whether a U2U relay discovery message to be transmitted occurs and whether a U2U sidelink discovery transmission resource is required. In operation 1001, the UE may determine whether a transmission resource pool for the purpose of sidelink discovery has been configured. When the UE determines that the transmission resource pool for the purpose of sidelink discovery has been configured according to the determination in operation 1001, in operation 1002, the UE may determine to select a transmission resource in the transmission resource pool for the purpose of sidelink discovery. When it is determined that the transmission resource pool for the purpose of sidelink discovery has not been configured according to the determination in operation 1001, in operation 1003, the UE may determine to select a transmission resource in a general sidelink transmission resource pool.

[0197] Fig.10b is a diagram illustrating an operation of processing a sidelink relay discovery message transmission resource in a wireless communication system in which a UE and another UE perform communication through a sidelink relay according to an embodiment of the present disclosure.

[0198] refer to Fig.10b , at operation 1050, the UE may determine whether a U2U relay discovery message to be transmitted occurs and whether a U2U side link discovery transmission resource is required. At operation 1051, the UE may determine whether a transmission resource pool for the purpose of U2U side link discovery has been configured. When it is determined according to the determination in operation 1051 that a transmission resource pool for the purpose of U2U side link discovery has been configured, at operation 1052, the UE may determine to select a transmission resource in the transmission resource pool for the purpose of U2U side link discovery. When it is determined according to the determination in operation 1051 that a transmission resource pool for the purpose of U2U side link discovery has not been configured, at operation 1053, the UE may determine to select a transmission resource in a general side link transmission resource pool.

[0199] Fig.10c is a diagram illustrating an operation of processing a sidelink relay discovery message transmission resource in a wireless communication system in which a UE and another UE perform communication through a sidelink relay according to an embodiment of the present disclosure.

[0200] refer to Fig.10c, in operation 1080, the UE may determine whether a U2U relay discovery message to be sent occurs and whether a U2U side link discovery transmission resource is required. In operation 1081, the UE may determine whether a transmission resource pool for the purpose of U2U side link discovery has been configured. When it is determined according to the determination in operation 1081 that the transmission resource pool for the purpose of U2U side link discovery has been configured, in operation 1082, the UE may determine to select a transmission resource in the transmission resource pool for the purpose of U2U side link discovery. When it is determined according to the determination in operation 1081 that the transmission resource pool for the purpose of U2U side link discovery has not been configured, in operation 1083, the UE may determine whether a dedicated resource pool for different purposes of discovery has been configured. When the UE determines according to the determination in operation 1083 that a dedicated resource pool for different purposes of discovery has been configured, in operation 1084, the UE may determine to select a transmission resource in the transmission resource pool for different purposes of side link discovery. When it is determined according to the determination in operation 1083 that a transmission resource pool for a different purpose of sidelink discovery has not been configured, in operation 1085 , the UE may determine to select a transmission resource in a general sidelink transmission resource pool.

[0201] When the sidelink transmission resources are obtained, the transmitting UE may configure one or more logical channels corresponding to the same destination identifier (destination layer 2 ID) as the same MAC PDU and send the MAC PDU by using the obtained transmission resources. If the UE is capable of supporting both U2N relay discovery and U2U relay discovery, different destination identifier values ​​may be configured for the U2N relay discovery message and the U2U relay discovery message. In addition, if the UE is capable of supporting both U2N relay discovery and U2U relay discovery, the same destination identifier value may be configured for the U2N relay discovery message and the U2U relay discovery message.

[0202] In a case where a transmitting UE is capable of supporting both U2U relay discovery message transmission and U2N relay discovery message transmission, and the same destination identifier is configured to be used in the U2U relay discovery message and the U2N relay discovery message, when the U2N relay discovery message and the U2U relay discovery message to be sent to the transmitting UE occur at the same time (when the MAC PDU is configured, the two messages are present in the MAC buffer of the UE, but not at exactly the same time point), the destination identifier is the same, and thus the transmitting UE can configure and send the MAC PDU so that the U2N relay discovery message and the U2U relay discovery message are included in the same MAC PDU. In a case where a dedicated resource pool for the purpose of U2U relay discovery message transmission is configured, even if the destination identifier configured for the U2U relay discovery message and the U2N relay discovery message is the same, the corresponding resources on which the transmission of the U2U relay discovery message and the U2N relay discovery message is possible are different from each other. Therefore, the MAC PDU including the U2U relay discovery message and the MAC PDU including the U2N relay discovery message can be configured separately.

[0203] In the case where a dedicated resource pool for the purpose of sidelink discovery message transmission is configured, the selected resources for the purpose of sidelink discovery message transmission can be used to send U2U relay discovery messages and U2N relay discovery messages. Therefore, if the destination identifiers configured for U2U relay discovery messages and U2N relay discovery messages are the same, the MAC PDU can be configured so that the U2U relay discovery message and the U2N relay discovery message are included in one MAC PDU. In the case where the resources for the purpose of general sidelink transmission are configured to be used to send U2U relay discovery messages and U2N relay discovery messages, the selected transmission resources can be used to send U2U relay discovery messages and U2N relay discovery messages. Therefore, if the destination identifiers configured for U2U relay discovery messages and U2N relay discovery messages are the same, the U2U relay discovery message and the U2N relay discovery message can be configured to be included in one MAC PDU.

[0204] The logical channel identifier for the U2U relay discovery message may be configured to have the same or different value as the logical channel identifier for the U2N relay discovery message, as described in the example of [Table 8].

[0205] Next, we will refer to Figures 11a to 11e Describes processes such as logical channel prioritization in which a MAC PDU for transmission of a U2U relay discovery message is configured based on information regarding whether destination identifiers configured for the U2U relay discovery message and the U2N relay discovery message are the same, and configuration of a transmission resource pool in which transmission of a sidelink discovery message is possible.

[0206] Fig.11a is a diagram illustrating an operation of processing transmission of a sidelink relay discovery message in a wireless communication system in which a UE and another UE perform communication through a sidelink relay according to an embodiment of the present disclosure.

[0207] Fig.11a Assume a case where a dedicated resource pool is configured for U2U relay discovery messages. That is, Fig.11a A case where a U2U side link discovery dedicated resource pool is configured in which transmission of a U2U relay discovery message is possible is shown.

[0208] refer to Fig.11a In operation 1101, the UE may determine that a U2U side link discovery dedicated resource pool in which transmission of a U2U relay discovery message is possible has been configured, and determine that resources have been obtained from the U2U side link discovery resource pool for the purpose of U2U relay discovery message transmission. In operation 1102, the UE may determine that a U2U side link discovery message (e.g., a U2U relay discovery message) to be newly transmitted exists in a buffer. In operation 1103, the UE may select a destination identifier of the U2U side link discovery message (e.g., a U2U relay discovery message). The UE may select the destination identifier according to the process of [Table 9] below.

[0209] [Table 9]

[0210]

[0211] In operation 1104, the UE may select a logical channel corresponding to the destination identifier selected in operation 1103. The UE may select a logical channel according to the procedure of [Table 10] below.

[0212] [Table 10]

[0213]

[0214] In operation 1105, the UE may perform an operation of allocating the transmission resources obtained in operation 1101 to the logical channel selected in operation 1104 as shown in the following [Table 11].

[0215] [Table 11]

[0216]

[0217] exist Fig.11aIn the embodiment of the present invention, for a U2N relay discovery message, a D2D direct discovery message, or a general side link message, the operation of selecting a destination identifier in the logical channel prioritization process that can be performed by the transmitting UE is as shown in [Table 12]. The operation of selecting a logical channel identifier for the selected destination identifier can be the same as the process of operation 1104.

[0218] [Table 12]

[0219]

[0220] Fig.11b and Fig.11c Assume a case where a dedicated resource pool is configured for the purpose of sidelink discovery message transmission. If a dedicated resource pool for the purpose of sidelink discovery message transmission has been configured, the transmitting UE may send a U2U relay discovery message or a U2N relay discovery message by using a transmission resource allocated from the resource pool for the purpose of sidelink discovery message transmission.

[0221] In a case where the UE is capable of supporting U2U relay discovery messages and U2N relay discovery messages and the same destination identifier is assigned to the U2U relay discovery messages and the U2N relay discovery messages, the UE may configure and send a MAC PDU including both the U2U relay discovery message and the U2N relay discovery message on transmission resources allocated for U2U relay discovery message transmission, and the UE may configure and send a MAC PDU including both the U2N relay discovery message and the U2U relay discovery message on transmission resources allocated for U2N relay discovery message transmission.

[0222] Fig.11b is a diagram illustrating an operation of processing transmission of a sidelink relay discovery message in a wireless communication system in which a UE and another UE perform communication through a sidelink relay according to an embodiment of the present disclosure.

[0223] refer to Fig.11b In operation 1111, the UE may determine that a sidelink discovery transmission resource pool has been configured, and determine that resources have been obtained from the resource pool for the purpose of sidelink discovery transmission. In operation 1112, the UE may determine that a U2U relay discovery message to be newly transmitted exists in a buffer. In operation 1113, the UE may select a destination identifier for the U2U relay discovery message. The UE may select a destination identifier according to the process of [Table 13] below.

[0224] [Table 13]

[0225]

[0226] In operation 1114, the UE may select a logical channel corresponding to the destination identifier selected in operation 1113. The UE may select a logical channel according to the procedure of [Table 14] below.

[0227] [Table 14]

[0228]

[0229] In operation 1115 , as shown in the following [Table 15], the UE may perform an operation of allocating the transmission resources obtained in operation 1111 to the logical channel selected in operation 1114 .

[0230] [Table 15]

[0231]

[0232] When it is determined that the obtained transmission resources are still available and a U2N relay discovery message with the same destination identifier as the U2U relay discovery message exists in the MAC buffer of the UE, the UE may allocate the logical channel corresponding to the U2N relay discovery message to the obtained transmission resources, configure the message as the same MAC PDU, and send the MAC PDU.

[0233] Fig.11c is a diagram illustrating an operation of processing transmission of a sidelink relay discovery message in a wireless communication system in which a UE and another UE perform communication through a sidelink relay according to an embodiment of the present disclosure.

[0234] refer to Fig.11c In operation 1121, the UE may determine that a sidelink discovery transmission resource pool has been configured, and determine that resources have been obtained from the resource pool for the purpose of sidelink discovery transmission. In operation 1122, the UE may determine that a U2N relay discovery message to be newly transmitted exists in a buffer. In operation 1123, the UE may select a destination identifier for the U2N relay discovery message. The UE may select a destination identifier according to the process of [Table 16] below.

[0235] [Table 16]

[0236]

[0237] In operation 1124, the UE may select a logical channel corresponding to the destination identifier selected in operation 1123. The UE may select a logical channel according to the procedure of [Table 17] below.

[0238] [Table 17]

[0239]

[0240] In operation 1125, as shown in the following [Table 18], the UE may perform an operation of allocating the transmission resources obtained in operation 1121 to the logical channel selected in operation 1124.

[0241] [Table 18]

[0242]

[0243] When it is determined that the obtained transmission resources are still available and a U2U relay discovery message with the same destination identifier as the U2N relay discovery message exists in the MAC buffer of the UE, the UE may allocate the logical channel corresponding to the U2U relay discovery message to the obtained transmission resources, configure the U2N relay discovery message and the U2U relay discovery message as the same MAC PDU, and send the MAC PDU.

[0244] exist Fig.11b and Fig.11c In the embodiment of the present invention, for a general sidelink message, the operation of selecting a destination identifier in the logical channel prioritization process that can be performed by the transmitting UE is as shown in [Table 19]. The operation of selecting a logical channel identifier for the selected destination identifier can be the same as the process of operation 1114 or operation 1124.

[0245] [Table 19]

[0246]

[0247] Fig.11d and Fig.11e Assume a case where a dedicated resource pool is not configured and a general sidelink transmission resource pool is configured for the purpose of sidelink discovery message transmission. The transmitting UE may send a U2U relay discovery message or a U2N relay discovery message by using transmission resources allocated from the general sidelink transmission resource pool.

[0248] Fig.11d is a diagram illustrating an operation of processing transmission of a sidelink relay discovery message in a wireless communication system in which a UE and another UE perform communication through a sidelink relay according to an embodiment of the present disclosure.

[0249] refer to Fig.11d In operation 1131, the UE may determine that a dedicated resource pool or a sidelink discovery transmission resource pool for the U2U relay discovery transmission purpose has not been configured, and determine that resources have been obtained from a general sidelink transmission resource pool. In operation 1132, the UE may determine that a U2N relay discovery message to be newly transmitted exists in a buffer. In operation 1133, the UE may select a destination identifier for the U2N relay discovery message. The UE may select a destination identifier according to the following [Table 20].

[0250] [Table 20]

[0251]

[0252] In operation 1134, the UE may select a logical channel corresponding to the destination identifier selected in operation 1133. The UE may select a logical channel according to the following [Table 21].

[0253] [Table 21]

[0254]

[0255] In operation 1135, the UE may perform an operation of allocating the transmission resources obtained in operation 1131 to the logical channel selected in operation 1134 as shown in the following [Table 22].

[0256] [Table 22]

[0257]

[0258] When it is determined that the obtained transmission resources are still available and a U2U relay discovery message with the same destination identifier as the U2N relay discovery message exists in the MAC buffer of the UE, the UE may allocate the logical channel corresponding to the U2U relay discovery message to the obtained transmission resources, configure the U2N relay discovery message and the U2U relay discovery message as the same MAC PDU, and send the MAC PDU.

[0259] Fig.11e is a diagram illustrating an operation of processing transmission of a sidelink relay discovery message in a wireless communication system in which a UE and another UE perform communication through a sidelink relay according to an embodiment of the present disclosure.

[0260] refer to Fig.11e In operation 1141, the UE may determine that a dedicated resource pool or a sidelink discovery transmission resource pool for the purpose of U2U relay discovery transmission has not been configured, and determine that resources have been obtained from a general sidelink transmission resource pool. In operation 1142, the UE may determine that a U2U relay discovery message to be newly transmitted exists in a buffer. In operation 1143, the UE may select a destination identifier for the U2U relay discovery message. The UE may select a destination identifier according to the following [Table 23].

[0261] [Table 23]

[0262]

[0263] In operation 1144, the UE may select a logical channel corresponding to the destination identifier selected in operation 1143. The UE may select a logical channel according to the following [Table 24].

[0264] [Table 24]

[0265]

[0266] In operation 1145, the UE may perform an operation of allocating the transmission resources obtained in operation 1141 to the logical channel selected in operation 1144 as shown in the following [Table 25].

[0267] [Table 25]

[0268]

[0269] When it is determined that the obtained transmission resources are still available and a U2N relay discovery message with the same destination identifier as the U2U relay discovery message exists in the MAC buffer of the UE, the UE may allocate the logical channel corresponding to the U2N relay discovery message to the obtained transmission resources, configure the U2U relay discovery message and the U2N relay discovery message as the same MAC PDU, and send the MAC PDU.

[0270] In a case where a dedicated resource pool (e.g., sl-BWP-U2UDiscPoolConfig or sl-BWP-U2UDiscPoolConfigCommon) for the purpose of U2U relay discovery message transmission has been configured according to an embodiment of the present disclosure, the operation of selecting a resource pool for U2U relay discovery message transmission by the transmitting UE is as shown in [Table 26].

[0271] [Table 26]

[0272]

[0273] As an embodiment, in a case where the UE is capable of supporting both the U2N relay discovery message and the U2U relay discovery message, it may be configured that: the distinction between the U2N relay discovery message and the U2U relay discovery message is processed in the discovery layer of the UE. As an embodiment, in a case where the UE is capable of supporting both the U2N relay discovery message and the U2U relay discovery message, it may be configured that: the distinction between the U2U relay discovery message and the U2N relay discovery message is processed in the discovery layer of the UE and the RRC layer, PDCP layer, RLC layer and / or MAC layer of the UE.

[0274] The UE that sends the U2N relay discovery message or the U2U relay discovery message may configure the U2N relay discovery message or the U2U relay discovery message in the discovery layer, and transmit the configured U2N relay discovery message or the U2U relay discovery message to the lower layer (PDCP layer). When sending the U2N relay discovery message or the U2U relay discovery message to the lower layer, the discovery layer of the UE may transmit an indicator indicating that the message is a sidelink discovery message to the PDCP layer and the RRC layer corresponding to the lower layer. The indicator that the message is a sidelink discovery message may not include an identifier for the U2U relay discovery message and an identifier for the U2N relay discovery message, and may be applied to the U2U relay discovery message and the U2N relay discovery message as the same sidelink discovery message indicator, or may be applied as a sidelink discovery message indicator that can identify the U2U relay discovery message and the U2N relay discovery message.

[0275] When the indicator includes an identifier for a U2N relay discovery message and an identifier for a U2U relay discovery message, a lower layer (RRC, PDCP, RLC, or MAC) of the UE may process a configuration defined for each discovery message. Even if information enabling identification that a message is a sidelink discovery message is transmitted to all lower layers of the UE, information about an identifier for a U2U relay discovery message and an identifier for a U2N relay discovery message may not be transmitted to all lower layers of the UE. When information enabling identification that a message is a sidelink discovery message and / or information about an identifier for a U2U relay discovery message and an identifier for a U2N relay discovery message are transmitted to the lower layers, for example, according to Fig. 9 In an embodiment of the present invention, RRC may process the configuration of the sidelink signaling radio bearer to be applied to the U2U relay discovery message or the U2N relay discovery message. Fig. 9 In an embodiment, when the PDCP data PDU is configured, processing of the sidelink signaling radio bearer corresponding to the U2U relay discovery message or the U2N relay discovery message and processing of the SDU type information may be performed according to the defined configuration. Fig. 9 In an embodiment, processing of a logical channel identifier corresponding to a U2U relay discovery message or a U2N relay discovery message may be performed according to a defined configuration. A higher layer of the UE may transmit identification information about a side link discovery message that does not have an identification for a U2N relay discovery message and an identification for a U2U relay discovery message, or a distinction between a U2N relay discovery message and a U2U relay discovery message, while transmitting a U2N relay discovery message or a U2U relay discovery message to a lower layer.

[0276] If there are separate identifiers for the U2U relay discovery message and the U2N relay discovery message, the PDCP layer of the UE may perform the PDCP data PDU processing configured for the U2N relay discovery message and the PDCP data PDU processing configured for the U2N relay discovery message (refer to Fig. 9 ). The U2U relay discovery message or the U2N relay discovery message processed in the PDCP layer of the UE may be delivered to the RLC layer, and the U2U relay discovery message or the U2N relay discovery message processed in the RLC layer may be delivered to the MAC layer. The MAC layer of the UE may perform processing of a destination identifier or a logical channel identifier corresponding to the U2U relay discovery message, and perform processing of a destination identifier or a logical channel identifier corresponding to the U2N relay discovery message, and then deliver the message to a lower layer.

[0277] If there is no separate distinction between the U2U relay discovery message and the U2N relay discovery message, the PDCP layer of the UE may perform PDCP data PDU processing configured for the purpose of sidelink discovery on the U2U relay discovery message or the U2N relay discovery message. The U2U relay discovery message and the U2N relay discovery message processed in the PDCP layer of the UE may be transferred to the RLC layer, and the U2U relay discovery message and the U2N relay discovery message processed in the RLC layer may be transferred to the MAC layer. The MAC layer of the UE may perform processing of a destination identifier or a logical channel identifier corresponding to the U2U relay discovery message and the U2N relay discovery message, and transfer the processed MAC PDU to a lower layer. The RLC layer and the MAC layer may perform RLC PDU processing and MAC PDU processing configured for the purpose of sidelink discovery on the U2U relay discovery message or the U2N relay discovery message, respectively.

[0278] When the receiving UE receives the MAC PDU including the U2U relay discovery message or the U2N relay discovery message, the receiving UE may transmit the MAC SDU to a higher layer of the receiving UE. If the MAC layer of the receiving UE is able to identify that the message is a side link discovery message, identify that the message is a U2U relay discovery message, or identify that the message is a U2N relay discovery message, the UE may receive information about an identifier for the side link discovery message, an identifier for the U2U relay discovery message, or an identifier for the U2N relay discovery message while transmitting the message to a higher layer.

[0279] For example, while transmitting a PDCP SDU including a U2U relay discovery message or a U2N relay discovery message to a higher layer (discovery layer), the PDCP layer of the receiving UE may transmit information about an identifier for a sidelink discovery message, an identifier for a U2U relay discovery message, or an identifier for a U2N relay discovery message. In a case where a destination identifier for a U2N relay discovery message and a destination identifier for a U2U relay discovery message may be used distinguishably, the MAC layer of the receiving UE may distinguish between the U2N relay discovery message and the U2U relay discovery message based on the destination identifier. In a case where a logical channel identifier for a U2N relay discovery message and a logical channel identifier for a U2U relay discovery message may be used distinguishably, the MAC layer of the receiving UE may distinguish between the U2N relay discovery message and the U2U relay discovery message based on the logical channel identifier.

[0280] Even when the lower layer (MAC, RLC, PDCP or RRC layer) of the receiving UE transmits identification information to the higher layer without distinguishing between the U2U relay discovery message and the U2N relay discovery message, the discovery layer of the receiving UE can distinguish between the U2U relay discovery message and the U2N relay discovery message.

[0281] The MAC entity of the receiving UE may perform the operations shown in the following [Table 27] to process the U2U relay discovery message.

[0282] [Table 27]

[0283]

[0284] According to an embodiment of the present disclosure, a base station may configure support information about U2U relay in a SIB message. An embodiment of a message including information about U2U relays that a base station can support may be as shown in the following [Table 28]. The base station may configure U2U relay discovery configuration information and information notifying layer 2 U2U relay (discovery or relay communication) support or layer 3 U2U relay discovery support in a SIB message.

[0285] [Table 28]

[0286]

[0287] The operation of selecting / reselecting a U2U relay UE by a remote UE supporting U2U relay according to an embodiment of the present disclosure is as shown in the example of [Table 29] below. The operation of selecting / reselecting a U2U relay UE by a remote UE supporting U2U relay can be applied to a case where the UE selects / reselects a sidelink relay capable of relaying a direct connection with another UE. When the sidelink relay is reselected, the remote UE may apply the quality of the sidelink signal (SD-RSRP or SL-RSRP) to which the sidelink relay is currently connected, and the sidelink relay selection criteria configured in a higher layer (discovery layer or ProSe layer). Configuration information about the sidelink signal quality for sidelink relay selection / reselection may be obtained from a base station connected to the remote UE (RRC dedicated message or SIB message) or from a pre-configured setting.

[0288] [Table 29]

[0289]

[0290]

[0291] Fig.12 A signal flow between a sidelink relay and a base station processing sidelink relay configuration information in a wireless communication system in which a UE and another UE perform communication through the sidelink relay according to an embodiment of the present disclosure is shown.

[0292] refer to Fig.12 , the sidelink relay 1200 may determine that the base station supports at least one or a combination of U2U relay discovery and U2U relay communication according to the configuration of the SIB message (example of [Table 28]) transmitted by the base station 1230, and transmit a SidelinkUEInformationNR message in operation 1201 to request sidelink relay configuration information and sidelink transmission resource information for at least one or a combination of U2U relay discovery or U2U relay communication from the base station 1230. In operation 1202, the sidelink relay 1200 may obtain an RRCReconfiguration message from the base station 1230, and perform an operation of obtaining configuration information required for the sidelink relay 1200 to perform a sidelink relay operation of at least one or a combination of U2U relay discovery or U2U relay communication from the RRCReconfiguration message. In operation 1203, the sidelink relay 1200 may transmit an RRCReconfigurationComplete message as a response to the RRCReconfiguration message received from the base station 1230.

[0293] Fig.13A signal flow between a UE and a base station processing sidelink relay configuration information in a wireless communication system in which the UE and another UE perform communication through a sidelink relay according to an embodiment of the present disclosure is illustrated.

[0294] refer to Fig.13 , the remote UE 1300 may determine that the base station supports at least one or a combination of U2U relay discovery and U2U relay communication according to the configuration of the SIB message (example of [Table 28]) transmitted by the base station 1330, and transmits a SidelinkUEInformationNR message in operation 1301 to request sidelink relay configuration information and sidelink transmission resource information for at least one or a combination of U2U relay discovery or U2U relay communication from the base station 1330. The remote UE 1300 may correspond to a source UE or a destination UE capable of performing direct connection communication by relay transmission using a sidelink relay.

[0295] In operation 1302, the remote UE 1300 may obtain an RRCReconfiguration message from the base station 1330, and perform an operation of obtaining configuration information required for the remote UE 1300 to perform a sidelink relay operation of at least one of U2U relay discovery or U2U relay communication or a combination thereof from the RRCReconfiguration message. In operation 1303, the remote UE 1300 may send an RRCReconfigurationComplete message as a response to the RRCReconfiguration message received from the base station 1330.

[0296] The SidelinkUEInformationNR message sent by the sidelink relay 1200 to the base station 1230 or by the remote UE 1300 to the base station 1330 can be used for at least one or a combination of the purposes shown in [Table 30] below.

[0297] [Table 30]

[0298]

[0299] Next, an embodiment of a SidelinkUEInformationNR message configured by a sidelink relay or remote UE to be sent to a base station according to the purpose of [Table 30] will be described.

[0300] [Table 31]

[0301]

[0302] [Table 32]

[0303]

[0304]

[0305] [Table 33]

[0306]

[0307]

[0308]

[0309] [Table 34]

[0310]

[0311]

[0312] The present disclosure relates to a method performed by a user equipment in a wireless communication system. The method may include: processing a relay discovery message for discovering a side link relay so as to perform direct connection communication with another user equipment, configuring and sending the side link relay discovery message according to whether a condition for sending the relay discovery message for discovering the side link relay is satisfied, monitoring and receiving the side link relay discovery message according to whether a condition for monitoring the relay discovery message for discovering the side link relay is satisfied, and obtaining and processing configuration information for performing a direct connection establishment process with other user equipment through the side link relay. The present disclosure relates to a method performed by a side link relay in a wireless communication system. The method may include: processing a relay discovery message for discovering a side link relay so as to perform direct connection communication between a user device and another user device, configuring and sending the side link relay discovery message according to whether a condition for sending the relay discovery message for discovering the side link relay is met, monitoring and receiving the side link relay discovery message according to whether a condition for monitoring the relay discovery message for discovering the side link relay is met, and obtaining and processing configuration information of relay transmission for a direct connection establishment process between the user device and another user device.

[0313] The methods disclosed in the claims and / or the methods according to the embodiments described in the specification of the present disclosure may be implemented by hardware, software, or a combination of hardware and software.

[0314] When the method is implemented by software, a computer-readable storage medium for storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium may be configured to be executed by one or more processors within an electronic device. At least one program includes instructions for causing an electronic device to perform a method according to various embodiments of the present disclosure, as defined by the attached claims and / or disclosed herein.

[0315] These programs (software modules or software) can be stored in a non-volatile memory, which includes random access memory and flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), magnetic disk storage devices, compact disk-ROM (CD-ROM), digital versatile disk (DVD) or other types of optical storage devices or tape cassettes. Alternatively, any combination of some or all of them can form a memory in which the program is stored. In addition, multiple such memories may be included in the electronic device.

[0316] In addition, the program can be stored in an attachable storage device that can access the electronic device through a communication network such as the Internet, an intranet, a local area network (LAN), a wide LAN (WLAN), and a storage area network (SAN) or a combination thereof. Such a storage device can access the electronic device via an external port. In addition, a separate storage device on a communication network can access the portable electronic device.

[0317] In the above detailed embodiments of the present disclosure, the elements included in the present disclosure are expressed in the singular or plural, depending on the detailed embodiments presented. However, the singular form or the plural form is appropriately selected for the presented situation for the convenience of description, and the present disclosure is not limited to the elements expressed in the singular or plural. Therefore, the elements expressed in the plural may also include a single element, or the elements expressed in the singular may also include multiple elements.

[0318] Although specific embodiments have been described in the detailed description of the present disclosure, it is apparent that various modifications and changes may be made thereto without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the embodiments set forth herein, but should be defined by the appended claims and their equivalents.

Claims

1. A method performed by a first user equipment (UE) in a wireless communication system, the method comprising: sending a direct communication request message for the second user equipment to a user equipment (UE) to UE (U2U) relay UE based on side link radio bearer (SLRB) configuration information for relaying communication between the first user equipment and the second user equipment; performing PC5 security configuration for direct communication with the second user device; receiving a direct communication accept message for a second user equipment from the U2U relay UE; as well as The UE performs direct communication with the second user equipment through the U2U relay.

2. The method according to claim 1, wherein: The SLRB configuration information includes configuration information about at least one of a sidelink signaling radio bearer (SL-SRB) and a sidelink data radio bearer (SL-DRB), and The SLRB configuration information is included in a radio resource control (RRC) message or a system information block (SIB) message received from a base station, included in radio bearer configuration information pre-configured in the first user equipment, or configured based on designated SLRB configuration information.

3. The method according to claim 1, wherein: The SLRB configuration information includes sidelink radio link control (RLC) bearer configuration information, and Among them, the side link RLC bearer configuration information is determined according to the RLC mode of SL-SRB.

4. The method according to claim 3, wherein: The side link RLC bearer configuration information includes: configuration information about a first SL-SRB to which an unacknowledged mode RLC (UM RLC) mode is to be applied and configuration information about a second SL-SRB to which an acknowledged mode RLC (AM RLC) mode is to be applied; Configuration information for applying the AM RLC mode to all SL-SRBs, the sidelink RLC bearer configuration information being to be applied to all SL-SRBs; or Configuration information for applying the UM RLC mode to all SL-SRBs, and the sidelink RLC bearer configuration information is to be applied to all SL-SRBs.

5. A method performed by a user equipment (UE) to UE (U2U) relay UE in a wireless communication system, the method comprising: receiving, from the first user equipment, a direct communication request message for the second user equipment based on the side link radio bearer (SLRB) configuration information; Sending a direct communication request message to the second user equipment; receiving a direct communication acceptance message from the second user equipment, the direct communication acceptance message including communication response information of the second user equipment in response to the direct communication request message, and transmitting the direct communication acceptance message to the first user equipment; and relaying direct communication between a first user device and a second user device, The SLRB configuration information indicates radio resources used by the U2U relay UE to relay communications between the first user equipment and the second user equipment.

6. The method according to claim 5, wherein: The SLRB configuration information includes configuration information about at least one of a sidelink signaling radio bearer (SL-SRB) and a sidelink data radio bearer (SL-DRB), and The SLRB configuration information is included in a radio resource control (RRC) message or a system information block (SIB) message received from a base station, included in radio bearer configuration information pre-configured in the first user equipment, or configured based on designated SLRB configuration information.

7. The method according to claim 5, wherein: The SLRB configuration information includes sidelink radio link control (RLC) bearer configuration information, and Among them, the side link RLC bearer configuration information is determined according to the RLC mode of SL-SRB.

8. The method according to claim 7, wherein: The side link RLC bearer configuration information includes: configuration information about a first SL-SRB to which an unacknowledged mode RLC (UM RLC) mode is to be applied and configuration information about a second SL-SRB to which an acknowledged mode RLC (AM RLC) mode is to be applied; Configuration information for applying the AM RLC mode to all SL-SRBs, the sidelink RLC bearer configuration information being to be applied to all SL-SRBs; or Configuration information for applying the UM RLC mode to all SL-SRBs, and the sidelink RLC bearer configuration information is to be applied to all SL-SRBs.

9. A first user equipment (UE) in a wireless communication system, the first user equipment comprising: Transceiver; and A controller, coupled to the transceiver, The controller is configured as follows: sending a direct communication request message for the second user equipment to a user equipment (UE) to UE (U2U) relay UE based on side link radio bearer (SLRB) configuration information for relaying communication between the first user equipment and the second user equipment; performing PC5 security configuration for direct communication with the second user device; receiving a direct communication accept message for a second user equipment from the U2U relay UE; as well as The UE performs direct communication with the second user equipment through the U2U relay.

10. The first user equipment according to claim 9, wherein: The SLRB configuration information includes configuration information about at least one of a sidelink signaling radio bearer (SL-SRB) and a sidelink data radio bearer (SL-DRB), and The SLRB configuration information is included in a radio resource control (RRC) message or a system information block (SIB) message received from a base station, included in radio bearer configuration information pre-configured in the first user equipment, or configured based on designated SLRB configuration information.

11. The first user equipment according to claim 9, wherein: The SLRB configuration information includes sidelink radio link control (RLC) bearer configuration information, and Among them, the side link RLC bearer configuration information is determined according to the RLC mode of SL-SRB.

12. The first user equipment according to claim 11, wherein: The side link RLC bearer configuration information includes: configuration information about a first SL-SRB to which an unacknowledged mode RLC (UM RLC) mode is to be applied and configuration information about a second SL-SRB to which an acknowledged mode RLC (AM RLC) mode is to be applied; Configuration information for applying the AM RLC mode to all SL-SRBs, the sidelink RLC bearer configuration information being to be applied to all SL-SRBs; or Configuration information for applying the UM RLC mode to all SL-SRBs, and the sidelink RLC bearer configuration information is to be applied to all SL-SRBs.

13. A user equipment (UE) to UE (U2U) relay UE in a wireless communication system, the U2U relay UE comprising: Transceiver; and A controller, coupled to the transceiver, The controller is configured as follows: receiving, from the first user equipment, a direct communication request message for the second user equipment based on the side link radio bearer (SLRB) configuration information; Sending a direct communication request message to the second user equipment; receiving a direct communication acceptance message from the second user equipment, the direct communication acceptance message including communication response information of the second user equipment in response to the direct communication request message, and transmitting the direct communication acceptance message to the first user equipment; and relaying direct communications between the first user equipment and the second user equipment, and The SLRB configuration information indicates radio resources used by the U2U relay UE to relay communications between the first user equipment and the second user equipment.

14. The U2U relay UE according to claim 13, wherein: The SLRB configuration information includes configuration information about at least one of a sidelink signaling radio bearer (SL-SRB) and a sidelink data radio bearer (SL-DRB), and The SLRB configuration information is included in a radio resource control (RRC) message or a system information block (SIB) message received from a base station, included in radio bearer configuration information pre-configured in the first user equipment, or configured based on designated SLRB configuration information.

15. The U2U relay UE according to claim 13, wherein: The SLRB configuration information includes sidelink radio link control (RLC) bearer configuration information, and The side link RLC bearer configuration information is determined according to the RLC mode of the SL-SRB and includes: configuration information about a first SL-SRB to which an unacknowledged mode RLC (UM RLC) mode is to be applied and configuration information about a second SL-SRB to which an acknowledged mode RLC (AM RLC) mode is to be applied; Configuration information for applying the AM RLC mode to all SL-SRBs, the sidelink RLC bearer configuration information being to be applied to all SL-SRBs; or Configuration information for applying the UM RLC mode to all SL-SRBs, and the sidelink RLC bearer configuration information is to be applied to all SL-SRBs.

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