KR20230148729A - Apparatus and method for supporting sidelink relay discovery operation in wireless communication system - Google Patents

Abstract

This disclosure relates to 5G or 6G communication systems to support higher data rates. According to various embodiments of the present disclosure, in a method of operating a first terminal in a wireless communication system, generating a sidelink relay discovery message to discover a sidelink relay for connection between the first terminal and the second terminal. A method is provided including a process, identifying a radio bearer to transmit the sidelink relay discovery message, and transmitting the sidelink relay discovery message through the radio bearer.

Description

Apparatus and method for supporting sidelink relay discovery in a wireless communication system {APPARATUS AND METHOD FOR SUPPORTING SIDELINK RELAY DISCOVERY OPERATION IN WIRELESS COMMUNICATION SYSTEM}

This disclosure relates to wireless communication systems. More specifically, it relates to a method and device for transmitting and receiving a sidelink relay discovery message when performing communication between remote terminals or between a remote terminal and a network through a sidelink relay in a wireless communication system.

5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and includes sub-6 GHz ('Sub 6GHz') bands such as 3.5 gigahertz (3.5 GHz) as well as millimeter wave (mm) bands such as 28 GHz and 39 GHz. It is also possible to implement it in the ultra-high frequency band ('Above 6GHz') called Wave. In addition, in the case of 6G mobile communication technology, which is called the system of Beyond 5G, Terra is working to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low delay time that is reduced to one-tenth. Implementation in Terahertz bands (e.g., 95 GHz to 3 THz) is being considered.

In the early days of 5G mobile communication technology, there were concerns about ultra-wideband services (enhanced Mobile BroadBand, eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC). With the goal of satisfying service support and performance requirements, efficient use of ultra-high frequency resources, including beamforming and massive array multiple input/output (Massive MIMO) to alleviate radio wave path loss in ultra-high frequency bands and increase radio transmission distance. Various numerology support (multiple subcarrier interval operation, etc.) and dynamic operation of slot format, initial access technology to support multi-beam transmission and broadband, definition and operation of BWP (Band-Width Part), large capacity New channel coding methods such as LDPC (Low Density Parity Check) codes for data transmission and Polar Code for highly reliable transmission of control information, L2 pre-processing, and dedicated services specialized for specific services. Standardization of network slicing, etc., which provides networks, has been carried out.

Currently, discussions are underway to improve and enhance the initial 5G mobile communication technology, considering the services that 5G mobile communication technology was intended to support, based on the vehicle's own location and status information. V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience, and NR-U (New Radio Unlicensed), which aims to operate a system that meets various regulatory requirements in unlicensed bands. ), NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with the terrestrial network is impossible, positioning, etc. Physical layer standardization for technology is in progress.

In addition, IAB (IAB) provides a node for expanding the network service area by integrating intelligent factories (Industrial Internet of Things, IIoT) to support new services through linkage and convergence with other industries, and wireless backhaul links and access links. Integrated Access and Backhaul, Mobility Enhancement including Conditional Handover and DAPS (Dual Active Protocol Stack) handover, and 2-step Random Access (2-step RACH for simplification of random access procedures) Standardization in the field of wireless interface architecture/protocol for technologies such as NR) is also in progress, and a 5G baseline for incorporating Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technology Standardization in the field of system architecture/services for architecture (e.g., Service based Architecture, Service based Interface) and Mobile Edge Computing (MEC), which provides services based on the location of the terminal, is also in progress.

When this 5G mobile communication system is commercialized, an explosive increase in connected devices will be connected to the communication network. Accordingly, it is expected that strengthening the functions and performance of the 5G mobile communication system and integrated operation of connected devices will be necessary. To this end, eXtended Reality (XR) and Artificial Intelligence are designed to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR). , AI) and machine learning (ML), new research will be conducted on 5G performance improvement and complexity reduction, AI service support, metaverse service support, and drone communication.

In addition, the development of these 5G mobile communication systems includes new waveforms, full dimensional MIMO (FD-MIMO), and array antennas to ensure coverage in the terahertz band of 6G mobile communication technology. , multi-antenna transmission technology such as Large Scale Antenna, metamaterial-based lens and antenna to improve coverage of terahertz band signals, high-dimensional spatial multiplexing technology using OAM (Orbital Angular Momentum), RIS ( In addition to Reconfigurable Intelligent Surface technology, Full Duplex technology, satellite, and AI (Artificial Intelligence) to improve the frequency efficiency of 6G mobile communication technology and system network are utilized from the design stage and end-to-end. -to-End) Development of AI-based communication technology that realizes system optimization by internalizing AI support functions, and next-generation distributed computing technology that realizes services of complexity beyond the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources. It could be the basis for .

This disclosure may provide a method of transmitting, receiving, and processing a sidelink relay discovery message when a terminal communicates with another terminal through a sidelink relay in a wireless communication system.

The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below. You will be able to.

According to various embodiments of the present disclosure, in a method of operating a first terminal in a wireless communication system, the process of generating a sidelink relay discovery message to discover a sidelink relay for connection between the first terminal and the second terminal A method is provided including a process of identifying a radio bearer to transmit a sidelink relay discovery message, and a process of transmitting a sidelink relay discovery message through the radio bearer.

According to various embodiments of the present disclosure, a first terminal in a wireless communication system includes a transceiver and at least one processor, and the at least one processor is a sidelink relay for connecting between the first terminal and the second terminal. A first terminal configured to generate a sidelink relay discovery message to discover, identify a radio bearer to transmit the sidelink relay discovery message, and transmit the sidelink relay discovery message through the radio bearer is provided.

According to an embodiment of the present disclosure, a service can be effectively provided to a terminal through a sidelink relay in a wireless communication system, and service coverage can be expanded.

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

FIG. 1A is a diagram illustrating a wireless communication system according to an embodiment of the present disclosure.
FIG. 1B is a diagram illustrating a wireless communication system according to an embodiment of the present disclosure.
FIG. 2 is a diagram illustrating the configuration of a base station in a wireless communication system according to an embodiment of the present disclosure.
FIG. 3 is a diagram illustrating the configuration of a relay or terminal in a wireless communication system according to an embodiment of the present disclosure.
FIG. 4 is a diagram illustrating the configuration of a communication unit in a wireless communication system according to an embodiment of the present disclosure.
FIG. 5 is a diagram illustrating the structure of time-frequency resources of a wireless communication system according to an embodiment of the present disclosure.
FIG. 6 is a diagram illustrating signal flows between a remote terminal and a sidelink relay that transmit and receive a sidelink relay discovery message between a remote terminal and another remote terminal according to an embodiment of the present disclosure.
FIG. 7 is a diagram illustrating signal flows between a remote terminal and a sidelink relay that transmit and receive a sidelink relay discovery message between a remote terminal and another remote terminal according to an embodiment of the present disclosure.
FIG. 8 is a diagram illustrating an operation in which a remote terminal and a sidelink relay transmit a sidelink relay discovery message between the remote terminal and another remote terminal according to an embodiment of the present disclosure.
FIG. 9 is a diagram illustrating an operation of a remote terminal and a sidelink relay receiving a sidelink relay discovery message between a remote terminal and another remote terminal according to an embodiment of the present disclosure. FIG. 10 is a side link relay according to an embodiment of the present disclosure. This is a diagram to explain transmission and/or reception of a link relay discovery message.

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the attached drawings. At this time, it should be noted that in the attached drawings, identical components are indicated by identical symbols whenever possible. Additionally, detailed descriptions of well-known functions and configurations that may obscure the gist of the present disclosure will be omitted.

In describing the embodiments in this specification, description of technical content that is well known in the technical field to which the present disclosure belongs and that is not directly related to the present disclosure will be omitted. This is to convey the gist of the present disclosure more clearly without obscuring it by omitting unnecessary explanation.

For the same reason, some components are exaggerated, omitted, or schematically shown in the accompanying drawings. Additionally, the size of each component does not entirely reflect its actual size. In each drawing, identical or corresponding components are assigned the same reference numbers.

The advantages and features of the present disclosure and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms, and the present embodiments are merely intended to ensure that the disclosure is complete and to provide common knowledge in the technical field to which the present disclosure pertains. It is provided to fully inform those who have the scope of the disclosure, and the disclosure is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

At this time, it will be understood that each block of the processing flow diagram diagrams and combinations of the flow diagram diagrams can be performed by computer program instructions. These computer program instructions can be mounted on a processor of a general-purpose computer, special-purpose computer, or other programmable data processing equipment, so that the instructions performed through the processor of the computer or other programmable data processing equipment are described in the flow chart block(s). It creates the means to perform functions. These computer program instructions may also be stored in computer-usable or computer-readable memory that can be directed to a computer or other programmable data processing equipment to implement a function in a particular manner, so that the computer-usable or computer-readable memory It is also possible to produce manufactured items containing instruction means that perform the functions described in the flowchart block(s). Computer program instructions can also be mounted on a computer or other programmable data processing equipment, so that a series of operational steps are performed on the computer or other programmable data processing equipment to create a process that is executed by the computer, thereby generating a process that is executed by the computer or other programmable data processing equipment. Instructions that perform processing equipment may also provide steps for executing the functions described in the flow diagram block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). Additionally, it should be noted that in some alternative execution examples it is possible for the functions mentioned in the blocks to occur out of order. For example, it is possible for two blocks shown in succession to be performed substantially at the same time, or it is possible for the blocks to be performed in reverse order depending on the corresponding function.

At this time, the term '~unit' used in this embodiment refers to software or hardware components such as FPGA or ASIC, and the '~unit' performs certain roles. However, '~part' is not limited to software or hardware. The '~ part' may be configured to reside in an addressable storage medium and may be configured to reproduce on one or more processors. Therefore, as an example, '~ part' refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and 'parts' may be combined into a smaller number of components and 'parts' or may be further separated into additional components and 'parts'. Additionally, components and 'parts' may be implemented to regenerate one or more CPUs within a device or a secure multimedia card.

In describing embodiments of the present disclosure in detail, the radio access network New RAN (NR) and the core network Packet Core (5G system, 5G system, Although the main target is 5G core network, or NG Core: next generation core), the main gist of the present disclosure can be applied to other communication systems with similar technical backgrounds without significantly departing from the scope of the present disclosure. It can be applied, and this will be possible at the discretion of a person with skilled technical knowledge in the technical field of the present disclosure.

In the 5G system, in order to support network automation, a network data collection and analysis function (NWDAF), which is a network function that provides the function of analyzing and providing data collected from the 5G network, can be defined. NWDAF can collect/store/analyze information from the 5G network and provide the results to an unspecified network function (NF), and the analysis results can be used independently by each NF.

For convenience of explanation below, some terms and names defined in the 3GPP standard (standard for 5G, NR, LTE, or similar systems) may be used. However, it is not limited by the terms and names of the present disclosure, and can be equally applied to systems that comply with other standards.

Hereinafter, the present disclosure relates to a method and device for transmitting and receiving a sidelink relay discovery message for a remote terminal to discover a sidelink relay in a wireless communication system. The present disclosure provides a method and device for processing, transmitting and receiving a relay discovery message to discover a sidelink relay in a wireless communication system when a remote terminal communicates with another remote terminal through a sidelink relay.

Specifically, the present disclosure relates to a sidelink relay or a remote terminal configuring a relay discovery message between the remote terminal and the remote terminal and transmitting the relay discovery message using a radio bearer configured for the relay discovery message between the remote terminal and the remote terminal. Provides a method. The present disclosure provides a method for a sidelink relay or a remote terminal to receive a relay discovery message using a radio bearer configured for the relay discovery message between the remote terminal and the remote terminal. According to embodiments of the present disclosure, a terminal can expand direct communication service coverage with other terminals through a sidelink relay, increase reliability of data transmission and reception, and minimize battery usage of the terminal.

In the following description, terms referring to signals, terms referring to channels, terms referring to control information, terms referring to network entities, terms referring to device components, etc. are used for convenience of explanation. This is exemplified. Therefore, it is not limited to the terms used in the present disclosure, and other terms referring to objects having equivalent technical meaning may be used.

Hereinafter, the base station is an entity that performs resource allocation for the terminal and may be at least one of gNode B, eNode B, Node B, BS (base station), wireless access unit, base station controller, or node on the network. A terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing communication functions. However, this is only an example, and base stations and terminals are not limited to these examples. In this disclosure, eNB may be used interchangeably with gNB for convenience of explanation. That is, a base station described as an eNB may represent a gNB. In this disclosure, the term terminal may refer to various wireless communication devices as well as mobile phones, NB-IoT devices, and sensors.

In the following description, physical channel and signal may be used interchangeably with data or control signals. For example, PDSCH (physical downlink shared channel) is a term that refers to a physical channel through which data is transmitted, but PDSCH can also be used to refer to data. That is, in the present disclosure, the expression 'transmit a physical channel' can be interpreted equivalently to the expression 'transmit data or a signal through a physical channel'.

Hereinafter, in this disclosure, upper signaling refers to a signal transmission method in which a signal is transmitted from a base station to a terminal using a downlink data channel of the physical layer, or from the terminal to the base station using an uplink data channel of the physical layer. High-level signaling can be understood as radio resource control (RRC) signaling or media access control (MAC) control element (CE).

In addition, in the present disclosure, the expressions greater than or less than are used to determine whether a specific condition is satisfied or fulfilled, but this is only a description for expressing an example, and the description of more or less is not used. It's not exclusion. Conditions written as ‘more than’ can be replaced with ‘more than’, conditions written as ‘less than’ can be replaced with ‘less than’, and conditions written as ‘more than and less than’ can be replaced with ‘greater than and less than’.

In addition, the present disclosure describes embodiments using terms used in some communication standards (eg, 3rd Generation Partnership Project (3GPP)), but this is only an example for explanation. Embodiments of the present disclosure can be easily modified and applied to other communication systems.

In addition, direct communication (sidelink communication) between terminals using the 5G communication system is being studied, and direct communication between terminals is, for example, vehicle-to-everything (V2X) and public safety network. ), it is expected to be able to provide various services to users.

In particular, there is a need for a method of utilizing sidelink relays that can support expansion of service coverage, increased reliability of data transmission, and reduced power consumption of terminals.

FIG. 1A is a diagram illustrating a wireless communication system according to an embodiment of the present disclosure.

Figure 1a is a portion of nodes that use a wireless channel in a wireless communication system, including a base station 110, terminals 130 and 140, and a sidelink relay 120 that can relay data transmission and reception between the base station and the terminal. Illustrate. Here, the sidelink relay corresponds to a U2N (UE to network) relay. Figure 1A shows only one base station, but other base stations identical or similar to base station 110 may be further included.

The base station 110 is a network infrastructure that provides wireless access to the terminals 130 and 140 and the relay 120. Base station 110 has coverage defined as a certain geographic area based on the distance over which signals can be transmitted. In addition to the base station, the base station 110 includes 'access point (AP)', 'eNodeB (eNB)', '5G node (5th generation node)', and 'next generation nodeB'. , gNB)', 'wireless point', 'transmission/reception point (TRP)', or other terms with equivalent technical meaning.

The relay 120 is a device used by a user or a network infrastructure and can communicate with the base station 110 through a wireless channel. The link from the base station 110 to the relay 120 may be referred to as downlink (DL), and the link from the relay 120 to the base station 110 may be referred to as uplink (UL). The base station 110 and the relay 120 may be connected through the Uu interface. Uplink (UL) refers to a wireless link through which the relay 120 transmits data or control signals to the base station 110, and downlink (DL) refers to a wireless link through which the base station 110 transmits data or control signals to the relay 120. Alternatively, it refers to a wireless link that transmits control signals.

The relay 120 may communicate with the terminal 130 and the terminal 140 through a wireless channel. At this time, the link between the relay 120 and the terminal 130 and the link between the relay 120 and the terminal 140 are referred to as sidelinks, and the sidelink may be referred to as a PC5 interface.

Each of the terminals 130 and 140 is a device used by a user and can communicate with the base station 110 through a wireless channel or communicate with the network through a wireless channel with the relay 120. In this disclosure, only the case where each of the terminal 130 and the terminal 140 performs communication through a wireless channel with the relay 120 is shown. At least one of the terminal 130 and the terminal 140 may be operated without user involvement. That is, at least one of the terminal 130 and the terminal 140 is a device that performs machine type communication (MTC) and may not be carried by the user. The terminal 130 and the terminal 140 each include a 'user equipment (UE)', a 'mobile station', a 'subscriber station', and a 'remote terminal' in addition to the terminal. )', 'wireless terminal', or 'user device', or other terms with equivalent technical meaning.

FIG. 1B is a diagram illustrating a wireless communication system according to an embodiment of the present disclosure.

Figure 1b is a portion of nodes using a wireless channel in a wireless communication system, which includes terminals 150 and 170 and a sidelink relay 160 capable of relaying data transmission and reception between terminals. The system is shown. Here, the sidelink relay 160 corresponds to a U2U (UE to UE) relay.

The relay 160 may communicate with the terminal 150 and the terminal 170 through a wireless channel. At this time, the link between the relay 160 and the terminal 150 and the link between the relay 160 and the terminal 170 are referred to as sidelinks, and the sidelink may be referred to as a PC5 interface.

Each of the terminal 150 and terminal 170 is a device used by a user and can communicate directly through a wireless channel or communicate with the other terminal through a wireless channel with the relay 160. At this time, 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 referred to as side links, and the side link is It may also be referred to as the PC5 interface.

At least one of the terminal 150 and the terminal 170 may be operated without user involvement. That is, at least one of the terminal 150 and the terminal 170 is a device that performs machine type communication (MTC) and may not be carried by the user. The terminal 150 and the terminal 170 each include a 'user equipment (UE)', a 'mobile station', a 'subscriber station', and a 'remote terminal' in addition to the terminal. )', 'wireless terminal', or 'user device', or other terms with equivalent technical meaning.

In the following description, uplink or downlink and Uu interface, sidelink, and PC-5 may be used interchangeably.

The base station 110, relays 120, 160, and terminals 130, 140, 150, and 170 shown in FIGS. 1A to 1B are in the mmWave band (e.g., 28 GHz, 30 GHz, 38 GHz, 60 GHz). It can transmit and receive wireless signals. At this time, to improve channel gain, the base station 110, relays 120 and 160, and terminals 130, 140, 150, and 170 may perform beamforming. Here, 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 to a transmitted signal or a received signal.

To this end, the base station 110, relays 120 and 160, and terminals 130, 140, 150, and 170 search for serving beams 112 through a beam search or beam management procedure. , 113, 121, 131, 141, 151, 161, 171) can be selected. After the serving beams (112, 113, 121, 131, 141, 151, 161, 171) are selected, communication is performed between the resource that transmitted the serving beams (112, 113, 121, 131, 141, 151, 161, 171) and the QCL It can be performed through resources in a (quasi co-located) relationship.

A first antenna port and a second antenna port are said to be in a QCL relationship if the large-scale characteristics of the channel carrying the symbols on the first antenna port can be inferred from the channel carrying the symbols on the second antenna port. can be evaluated. For example, a wide range of characteristics include delay spread, doppler spread, doppler shift, average gain, average delay, and spatial receiver parameters. It may include at least one of:

The terminal 130, terminal 140, terminal 150, and terminal 170 shown in FIGS. 1A to 1B can support vehicle communication. In the case of vehicle communication, in the LTE system, standardization work on V2X (vehicle to everything) technology was completed in 3GPP Release 14 and Release 15 based on the device-to-device (D2D) structure, and based on 5G NR. Standardization work for V2X technology was completed in 3GPP Release 16. NR V2X supports unicast communication, groupcast (or multicast) communication, and broadcast communication between terminals. In addition, unlike LTE V2X, which aims to transmit and receive basic safety information required for vehicle driving on the road, NR V2X provides various functions such as group driving (platooning), advanced driving (advanced driving), extended sensors, remote driving, etc. Together, we aim to provide more advanced services. V2X services can be divided into basic safety services and advanced services. Basic safety services range from vehicle notification (CAM (cooperative awareness messages) or BSM (basic safety message)) service to left turn notification service, front car collision warning service, emergency vehicle approach notification service, front obstacle warning service, and intersection signal information. It may include detailed services such as services, and V2X information can be transmitted and received using broadcast, unicast, or group cast transmission methods. The advanced service not only has stronger QoS (quality of service) requirements than the basic safety service, but also provides a unique service in addition to broadcast to enable transmission and reception of V2X information within a specific vehicle group or between two vehicles. A method to transmit and receive V2X information using cast and group cast transmission methods is required. Advanced services may include detailed services such as platooning services, autonomous driving services, remote driving services, and extended sensor-based V2X services. Additionally, NR V2X can provide public safety services by supporting direct communication services between devices in areas without network infrastructure.

Hereinafter, sidelink (SL) refers to the transmission/reception path for signals between a terminal and a terminal, or a transmission/reception path for signals between a terminal and a relay, and can be used interchangeably with the PC5 interface. Hereinafter, a base station is an entity that performs resource allocation for terminals and relays, 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, the base station may mean an NR base station (eg, gNB), an LTE base station (eg, eNB), or a road site unit (RSU). Terminals include not only general user equipment and mobile stations, but also vehicles that support vehicle-to-vehicular (V2V) communication, and vehicle-to-pedestrian communication (vehicular-to-pedestrian). , vehicle or pedestrian handsets (e.g. smartphones) supporting vehicle-to-network (V2P), vehicles supporting vehicle-to-network (V2N) communication, or communication between vehicles and transportation infrastructure (vehicular). It can include an RSU equipped with vehicle and terminal functions that support V2I (V2I), an RSU equipped with a base station function, or an RSU equipped with part of the base station function and part of the terminal function.

Meanwhile, in the present disclosure, the terminal is a vehicle supporting communication between vehicles (vehicular-to-vehicular, V2V), a vehicle supporting communication between vehicles and pedestrians (vehicular-to-pedestrian, V2P), or a pedestrian's handset ( Example: smartphone), a vehicle that supports communication between a vehicle and a network (vehicular-to-network, V2N), or a vehicle that supports communication between a vehicle and infrastructure (vehicular-to-infrastructure, V2I) It can mean. A terminal may refer to a user device that supports communication between devices in the public safety network.

Additionally, in the present disclosure, the terminal may mean an RSU (road side unit) equipped with a terminal function, an RSU equipped with a base station function, or an RSU equipped with a part of the base station function and a part of the terminal function.

In this disclosure, a relay may mean a user device that supports communication between vehicles supporting V2X communication or devices in the public safety network. Additionally, in the present disclosure, a relay may mean a device equipped with a terminal function, a device equipped with a base station function, or a device equipped with a part of a terminal function and a part of a base station function.

FIG. 2 is a diagram illustrating the configuration of a base station in a wireless communication system according to an embodiment of the present disclosure.

The configuration shown in FIG. 2 may be understood as the configuration of a base station (eg, 110 in FIG. 1A). Terms such as '... unit' and '... unit' used hereinafter refer to a unit that processes at least one function or operation, which can be implemented through hardware, software, or a combination of hardware and software. there is.

Referring to FIG. 2, the base station 110 may include a wireless communication unit 210, a backhaul communication unit 220, a storage unit 230, and a control unit 240. However, the components of the base station 110 are not limited to the examples described above. For example, a base station may include more or fewer components than those described above. In addition, the wireless communication unit 210, the backhaul communication unit 220, the storage unit 230, and the control unit 240 may be implemented in the form of a single chip. Additionally, the control unit 240 may include one or more processors.

The wireless communication unit 210 may perform functions for transmitting and receiving signals through a wireless channel. For example, the wireless communication unit 210 may perform a conversion function between a baseband signal and a bit string according to the physical layer standard of the system. For example, when transmitting data, the wireless communication unit 210 may generate complex symbols by encoding and modulating the transmission bit stream. Additionally, when receiving data, the wireless communication unit 210 can restore the received bit stream by demodulating and decoding the baseband signal.

Additionally, the wireless communication unit 210 up-converts the baseband signal into a radio frequency (RF) band signal and transmits it through an 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 convertor (DAC), an analog to digital convertor (ADC), etc. Additionally, the wireless communication unit 210 may include a plurality of transmission and reception paths. Furthermore, the wireless communication unit 210 may include at least one antenna array composed of a plurality of antenna elements.

In terms of hardware, the wireless communication unit 210 may be composed of a digital unit and an analog unit, and the analog unit includes a plurality of sub-units according to operating power, operating frequency, etc. It can be composed of: A digital unit may be implemented with at least one processor (eg, digital signal processor (DSP)).

The wireless communication unit 210 transmits and receives signals as described above. Accordingly, all or part of the wireless communication unit 210 may be referred to as a 'transmitter', 'receiver', or 'transceiver'. Additionally, in the following description, transmission and reception performed through a wireless channel are used to mean that the processing as described above is performed by the wireless communication unit 210.

The backhaul communication unit 220 may provide an interface for communicating with other nodes in the network. That is, the backhaul communication unit 220 converts a bit string transmitted from the base station 110 to another node, for example, another access node, another base station, a higher node, a core network, etc., into a physical signal, and converts the bit string received from the other node into a physical signal. Physical signals can be converted into bit strings.

The storage unit 230 may store data such as basic programs, application programs, and setting information for operation of the base station 110. The storage unit 230 may be comprised of volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. Additionally, the storage unit 230 may provide stored data upon request from the control unit 240.

The control unit 240 can control the overall operations of the base station 110. For example, the control unit 240 may transmit and receive signals through the wireless communication unit 210 or the backhaul communication unit 220. Additionally, the control unit 240 records and reads data from the storage unit 230. Additionally, the control unit 240 can perform protocol stack functions required by communication standards. According to another implementation example, the protocol stack may be included in the wireless communication unit 210. For this purpose, the control unit 240 may include at least one processor. According to one embodiment, the control unit 240 may control the base station 110 to perform operations according to embodiments described later.

FIG. 3 is a diagram illustrating the configuration of a relay or terminal in a wireless communication system according to an embodiment of the present disclosure.

The configuration shown in FIG. 3 may be understood as the configuration of a relay (eg, 120 in FIG. 1A) or a terminal (eg, 130 and 140 in FIG. 1A). Terms such as '... unit' and '... unit' used hereinafter refer to a unit that processes at least one function or operation, which can be implemented through hardware, software, or a combination of hardware and software. there is.

Referring to FIG. 3, the relay 120 or terminals 130 and 140 may include a communication unit 310, a storage unit 320, and a control unit 330. However, the components of the relay 120 or the terminals 130 and 140 are not limited to the examples described above. For example, the relay 120 or the terminals 130 and 140 may include more or fewer components than the aforementioned components. In addition, the communication unit 310, the storage unit 320, and the control unit 330 may be implemented in the form of a single chip. Additionally, the control unit 330 may include one or more processors.

The communication unit 310 performs functions for transmitting and receiving signals through a wireless channel. For example, the communication unit 310 may perform a conversion function between a baseband signal and a bit string according to the physical layer standard of the system. For example, when transmitting data, the communication unit 310 generates complex symbols by encoding and modulating the transmission bit string. Additionally, when receiving data, the communication unit 310 can restore the received bit stream by demodulating and decoding the baseband signal. Additionally, the communication unit 310 may up-convert the baseband signal into an RF band signal and transmit it 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, etc.

Additionally, the communication unit 310 may include a plurality of transmission and reception paths. Furthermore, the communication unit 310 may include at least one antenna array composed of a plurality of antenna elements. In terms of hardware, the communication unit 310 may be composed of digital circuits and analog circuits (eg, radio frequency integrated circuit (RFIC)). Here, the digital circuit and analog circuit can be implemented in one package. Additionally, the communication unit 310 may include a plurality of RF chains. Furthermore, the communication unit 310 may perform beamforming.

The communication unit 310 can transmit and receive signals as described above. Accordingly, all or part of the communication unit 310 may be referred to as a 'transmitter', 'receiver', or 'transceiver'. Additionally, in the following description, transmission and reception performed through a wireless channel may be used to mean that the processing as described above is performed by the communication unit 310.

The storage unit 320 may store data such as basic programs, application programs, and setting information for the operation of the relay 120 or the terminals 130 and 140. The storage unit 320 may be comprised of volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. And, the storage unit 320 provides stored data according to the request of the control unit 330.

The control unit 330 controls the overall operations of the relay 120 or the terminals 130 and 140. For example, the control unit 330 may transmit and receive signals through the communication unit 310. Additionally, the control unit 330 records and reads data from the storage unit 320. Additionally, the control unit 330 can perform protocol stack functions required by communication standards. To this end, the control unit 330 may include at least one processor or microprocessor, or may be part of a processor. Additionally, a portion of the communication unit 310 and the control unit 330 may be referred to as a communication processor (CP). According to one embodiment, the control unit 330 may control the relay 120 or the terminals 130 and 140 to perform operations according to embodiments described later.

FIG. 4 is a diagram illustrating the configuration of a communication unit in a wireless communication system according to an embodiment of the present disclosure.

FIG. 4 shows an example of the detailed configuration of the wireless communication unit 210 of FIG. 2 or the communication unit 310 of FIG. 3. Specifically, FIG. 4 shows components for performing beamforming as part of the wireless communication unit 210 of FIG. 2 or the communication unit 310 of FIG. 3.

Referring to FIG. 4, the wireless communication unit 210 or communication unit 310 includes an encoding and modulation unit 402, a digital beamforming unit 404, a plurality of transmission paths (406-1 to 406-N), and an analog beam. It may include a forming part 408.

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

The digital beamforming unit 404 may perform beamforming on digital signals (eg, modulation symbols). To this end, the digital beamforming unit 404 multiplies the modulation symbols by beamforming weights. Here, beamforming weights are used to change the size and phase of the signal, and may be referred to as a 'precoding matrix', 'precoder', etc. The digital beamforming unit 404 may output digitally beamformed modulation symbols to a plurality of transmission paths 406-1 to 406-N. At this time, according to the multiple input multiple output (MIMO) transmission technique, the modulation symbols may be multiplexed or the same modulation symbols may be provided to a plurality of transmission paths 406-1 to 406-N.

The plurality of transmission paths 406-1 to 406-N may convert digital beamformed digital signals into analog signals. To this end, each of the plurality of transmission paths 406-1 to 406-N may include an inverse fast fourier transform (IFFT) operation unit, a cyclic prefix (CP) insertion unit, a DAC, and an upconversion unit. The CP insertion unit is for the OFDM (orthogonal frequency division multiplexing) method, and may be excluded when another physical layer method (e.g., filter bank multi-carrier (FBMC)) is applied. That is, the plurality of transmission paths 406-1 to 406-N can provide an independent signal processing process for a plurality of streams generated through digital beamforming. However, depending on the implementation method, some of the components of the plurality of transmission paths 406-1 to 406-N may be commonly used.

The analog beamforming unit 408 can perform beamforming on analog signals. To this end, the digital beamforming unit 404 may multiply the analog signals by beamforming weights. Here, beamforming weights are used to change the size and phase of the signal. Specifically, depending on the connection structure between the plurality of transmission paths 406-1 to 406-N and the antennas, the analog beamforming unit 440 may be configured in various ways. For example, each of the plurality of transmission paths 406-1 to 406-N may be connected to one antenna array. As another example, a plurality of transmission paths 406-1 to 406-N may be connected to one antenna array. As another example, the plurality of transmission paths 406-1 to 406-N may be adaptively connected to one antenna array or to two or more antenna arrays.

FIG. 5 is a diagram illustrating the structure of time-frequency resources of a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 5, in the radio resource area, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain is an OFDM symbol or DFT-S-OFDM symbol, where Nsymb OFDM symbols or DFT-S-OFDM symbols 530 are one It may be included in slot 505. Unlike slots, in the NR system, the length of a subframe can be defined as 1.0 ms, and the length of a radio frame 500 can be defined as 10 ms. The minimum transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission bandwidth may include a total of NBW subcarriers 525. Specific values such as Nsymb and NBW can be applied variably depending on the system.

The basic unit of the time-frequency resource area is a resource element (RE) 510, which can be expressed as an OFDM symbol index or a DFT-S-OFDM symbol index and a subcarrier index. A resource block (RB 515) may be defined as NRB consecutive subcarriers 520 in the frequency domain. In general, the minimum data transmission unit is RB, and in NR systems, Nsymb = 14 and NRB = 12.

The structure of time-frequency resources as shown in FIG. 5 can be applied to the Uu interface. Additionally, the time-frequency resource structure as shown in FIG. 5 can be similarly applied to sidelinks.

Sidelink relay, which can transmit and transmit packets between a remote terminal and another remote terminal or between a remote terminal and a network, is a specific service, a specific terminal, a specific sidelink flow, a specific sidelink bearer, a specific unicast link, a specific It may be authenticated to be used in at least one of a source identifier and a specific destination identifier. The sidelink relay can establish a direct connection with an authenticated terminal at the time of installation. In one embodiment, the sidelink relay may transmit a sidelink relay discovery message and perform a sidelink direct connection establishment procedure with the authenticated terminal. In another embodiment, the sidelink relay may receive a sidelink relay discovery message from an authenticated terminal, transmit a sidelink relay discovery message to the authenticated terminal, and perform a sidelink direct connection setup procedure with the authenticated terminal. Sidelink relay and remote terminal may support sidelink relay between the remote terminal and the network and/or support sidelink relay between the remote terminal and another remote terminal. If the sidelink relay and the remote terminal support both sidelink relay between the remote terminal and the network and sidelink relay between the remote terminal and another remote terminal, sidelink relay discovery when sending or receiving a sidelink relay discovery message. The relay discovery message can be configured and processed by distinguishing whether the message is a relay discovery message for sidelink relay between a remote terminal and a network or a relay discovery message for sidelink relay between a remote terminal and another remote terminal. In various embodiments, a sidelink relay discovery message can be understood as a message transmitted between a sidelink relay and a terminal to initiate a sidelink relay discovery procedure, and may be a message for discovery or a message for a request for discovery. It may also be included. Configuration information necessary for the sidelink relay terminal and the sidelink remote terminal to transmit or receive a sidelink relay discovery message may be obtained from the base station or set in advance.

The terminal may be authenticated to use a sidelink direct connection in at least one 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 identifier. In one embodiment, the terminal may transmit a sidelink discovery message to discover other terminals that can perform sidelink direct connection establishment and perform a sidelink direct connection establishment procedure with the authenticated terminal. In another embodiment, the terminal may receive a sidelink discovery message from an authenticated terminal, transmit the sidelink discovery message to the authenticated terminal, and perform a sidelink direct connection establishment procedure with the authenticated terminal.

In a relay discovery procedure that can relay packet transmission and reception between a remote terminal and another remote terminal or packet transmission and reception between a remote terminal and a network, the transmission mode for transmitting a sidelink relay discovery message between a remote terminal and a sidelink relay is unicast; It may apply to either group cast or broadcast.

A remote terminal communicating with a sidelink relay can maintain one of RRC connected mode (RRC_CONNECTED state), RRC idle mode (RRC_IDLE state), and RRC inactive mode (RRC_INACTIVE state) with respect to the base station. A sidelink relay communicating with a remote terminal may maintain one of RRC connected mode (RRC_CONNECTED state), RRC idle mode (RRC_IDLE state), and RRC inactive mode (RRC_INACTIVE state) for the base station. The sidelink relay and the remote terminal can perform the roles of the transmitting terminal and receiving terminal of sidelink direct communication to each other, and maintain one of RRC connected mode, RRC idle mode, and RRC deactivated mode for the base station and enable sidelink direct communication. Communication can be performed.

According to various embodiments of the present invention, a sidelink relay discovery message used to discover a sidelink relay capable of relaying between a remote terminal and another remote terminal may include at least one of the following.

(One) PC5 relay discovery message

(2) DCR (direct communication request) message with relay discovery indication, this message corresponds to the case of expanding the DCR message sent to establish a sidelink-based direct connection between the terminal and the terminal for the purpose of sidelink relay discovery. When used for this purpose, information corresponding to relay discovery indication may be included.

The remote terminal and/or sidelink relay may use (1) or (2) as a sidelink relay discovery message between the remote terminal and another remote terminal.

Next, referring to FIG. 6, an example in which the remote terminal and the sidelink relay uses (1) as a sidelink relay discovery message, and with reference to FIG. 7, the remote terminal and the sidelink relay use (2) as a sidelink relay discovery message. An example of use as will be described.

FIG. 6 is a diagram illustrating signal flows between a remote terminal and a sidelink relay that transmit and receive a sidelink relay discovery message between a remote terminal and another remote terminal according to an embodiment of the present disclosure.

Referring to FIG. 6, when remote terminal A (600) attempts to perform sidelink-based direct communication with remote terminal B (650), it connects directly to remote terminal B (650) or connects to remote terminal B (650). It can be connected to remote terminal B (650) through relay of the side link relay (630). If remote terminal A (600) determines that it must perform a procedure to search for the sidelink relay 630 in step 601, as an example, remote terminal A (600) receives a sidelink relay search message from the sidelink relay 630. If it is determined that is not received, a sidelink relay search request message may be transmitted in step 603 to search for the sidelink relay 630. If the sidelink relay 630 receives a sidelink relay discovery request message from remote terminal A 600 and determines that the sidelink relay discovery message can be transmitted, it may transmit the sidelink relay discovery message in step 605. The sidelink relay discovery request message in step 603 and the sidelink relay discovery message in step 605 may correspond to the PC5 relay discovery message. Remote terminal A (630) receives the sidelink relay discovery message transmitted by the sidelink relay 630, selects the sidelink relay 630, and performs a sidelink direct connection procedure with the selected sidelink relay 630 in step 607. can be performed. If remote terminal A (600) determines that it is necessary to perform a procedure for searching the sidelink relay 630, as an example, remote terminal A (600) sends a sidelink relay discovery message transmitted by the sidelink relay 630. It can be monitored and received in step 609. The sidelink relay discovery message transmitted by the sidelink relay 630 and received by remote terminal A (600) in step 609 may correspond to a PC5 relay discovery message. Remote terminal A (600) may perform a sidelink direct connection procedure in step 611 with the sidelink relay 630 selected in step 611. Remote terminal B (650) may perform the sidelink relay discovery procedure in steps 603 to 607 or the sidelink relay discovery procedure in steps 609 to 611. Remote terminal A (600) and remote terminal B (650) can perform sidelink-based direct communication through relay of the sidelink relay (630).

FIG. 7 is a diagram illustrating signal flows between a remote terminal and a sidelink relay that transmit and receive a sidelink relay discovery message between a remote terminal and another remote terminal according to an embodiment of the present disclosure.

Referring to FIG. 7, when remote terminal A (700) attempts to perform sidelink-based direct communication with remote terminal B (750), it connects directly to remote terminal B (750) or connects to remote terminal B (750). It can be connected to remote terminal B (750) through relay of the side link relay (730). If remote terminal A (700) determines in step 701 that it is necessary to perform a procedure to search for a sidelink relay (730) to connect to remote terminal B (750), remote terminal A (700) sends a message to remote terminal B (759). A relay discovery indication may be included in the DCR message to be delivered and transmitted to the sidelink relay 730 in step 703. The DCR message with relay discovery indication message in step 703 may correspond to a sidelink relay discovery message. If the sidelink relay 730 receives a DCR message with relay discovery indication, that is, a sidelink relay discovery message, from remote terminal A (700) and determines that sidelink relay can be performed, the sidelink relay 730 receives a DCR message with relay discovery indication from remote terminal A (700) in step 705. The received DCR message can be transmitted to remote terminal B (750). The DCR message in step 705 may not include relay discovery indication information. Remote terminal B (750) may transmit a direct connection accept message in step 707 to communicate with remote terminal A (700) through relay of the side link relay (730). The sidelink relay 730 may transmit the direct connection accept message of the remote terminal B (750) to the remote terminal A (700) in step 709. Remote terminal A (700) and side link relay (730), remote terminal B (750) and side link relay (730) are side links for relaying data transmission between remote terminal A (700) and remote terminal B (750). You can perform a direct connection procedure. Remote terminal A (700) and remote terminal B (750) can perform sidelink-based direct communication through relay of the sidelink relay (730).

According to various embodiments of the present invention, a sidelink relay discovery message (including a sidelink relay discovery request message) is transmitted and received in the procedure of FIGS. 6 and 7, that is, a procedure for discovering a sidelink relay between a remote terminal and another remote terminal. We will explain how to handle this.

(One) Option 1

A sidelink relay discovery message and a sidelink relay discovery request message can be transmitted and received using the format of a PC5 relay discovery message or a DCR message with relay discovery indication.

The sidelink radio bearer that transmits/receives the PC5 relay discovery message or DCR message with relay discovery indication can be configured as SL-SRB4 (sidelink signaling radio bearer 4). In other words, the sidelink radio bearer that transmits/receives sidelink relay discovery messages between a remote terminal and another remote terminal is the same as the sidelink radio bearer that transmits/receives sidelink relay discovery messages between a remote terminal and the network. Can be set to SRB4. A DCR message requesting establishment of a general sidelink direct connection between a remote terminal and another remote terminal may be configured to use SL-SRB0.

In cases where the sidelink relay and/or remote terminal support both sidelink relay discovery between the remote terminal and another remote terminal and sidelink relay discovery between the remote terminal and the network, the upper layer of the sidelink relay (e.g., ProSe layer, V2X layer, PC5-S layer), the upper layer of the remote terminal determines whether the sidelink discovery message to be transmitted to each RRC layer is a sidelink relay discovery between the remote terminal and another remote terminal or a sidelink between the remote terminal and the network. Information indicating whether it is a relay search can be transmitted. The RRC layer can transmit information indicating whether it is a sidelink relay search between a remote terminal and another remote terminal, and information indicating whether it is a sidelink relay search between a remote terminal and a network to the PDCP layer, RLC layer, and MAC layer. When information indicating whether sidelink relay discovery between the remote terminal and another remote terminal is transmitted from the upper layer of the transmitting terminal (remote terminal or sidelink relay) to the RRC layer, the RRC layer SRB4 can be set and the PDCP layer can be instructed to create a PDCP entity that can process SL-SRB4. When an instruction is sent from the upper layer of the transmitting terminal that transmission of the sidelink relay discovery message between the remote terminal and other remote terminals is no longer required, the RRC layer instructs the PDCP layer to transmit the sidelink relay discovery message between the remote terminal and other remote terminals. An instruction can be sent to release the PDCP entity created for this purpose. A PDCP entity that receives sidelink relay discovery messages between a remote terminal and another remote terminal may be created and released in the same manner as a PDCP entity that receives sidelink relay discovery messages between a remote terminal and a network.

In the case where the receiving terminal (sidelink relay or remote terminal) supports both sidelink relay discovery between the remote terminal and another remote terminal and sidelink relay discovery between the remote terminal and the network, the PDCP layer of the receiving terminal is different from that of the remote terminal. When it is determined that a sidelink relay discovery message between a remote terminal has been received or a sidelink relay discovery message between a remote terminal and a network has been received, the PDCP layer of the receiving terminal is connected to each upper layer (e.g., ProSe layer, V2X Information indicating whether the sidelink discovery message received is a sidelink relay discovery between a remote terminal and another remote terminal or a sidelink relay discovery between a remote terminal and a network may be transmitted to the layer (PC5-S layer).

The logical channel for transmitting and receiving sidelink relay discovery messages between a remote terminal and another remote terminal and the logical channel for transmitting and receiving sidelink relay discovery messages between a remote terminal and the network may be set differently. A logical channel configured differently can be used to distinguish between a sidelink relay discovery message between a remote terminal and another remote terminal and a sidelink relay discovery message between a remote terminal and a network. The MAC layer can select the corresponding logical channel according to the indication information from the RRC layer about whether it is a sidelink relay discovery message between a remote terminal and another remote terminal or a sidelink relay discovery message between a remote terminal and the network. The transmitting terminal (remote terminal or sidelink relay) is configured according to the sidelink relay discovery message instruction between the remote terminal and another remote terminal or the sidelink relay discovery message instruction between the remote terminal and the network transmitted by the RRC layer to the MAC layer. A sidelink discovery message can be transmitted through a logical channel. The receiving terminal (remote terminal or sidelink relay) receives the information through the logical channel corresponding to the sidelink relay discovery message between the remote terminal and another remote terminal or the logical channel corresponding to the sidelink relay discovery message between the remote terminal and the network. The sidelink discovery message can be determined and information indicating which relay discovery message it is can be transmitted to the upper layer.

The resource pool for transmitting sidelink relay discovery messages between a remote terminal and another remote terminal may be set as a discovery message transmission-only pool or as a general sidelink message transmission pool. When selecting a resource for transmitting a sidelink relay discovery message between a remote terminal and another remote terminal, the remote terminal and the sidelink relay can select a resource from the discovery message transmission dedicated pool if it is determined that a discovery message transmission dedicated pool is set, and the discovery message transmission dedicated pool can be selected. If it is determined that a dedicated message transmission pool is not set up, resources can be selected from the general sidelink message transmission pool.

When the remote terminal and the sidelink relay transmit and receive sidelink relay discovery messages between the remote terminal and other remote terminals, the destination layer is in the Layer-2 ID pool set for the sidelink relay discovery message between the remote terminal and other remote terminals. You can select -2 ID and/or source layer-2 ID. This Layer-2 ID pool can be set separately from the Layer-2 ID pool set for general sidelink communication purposes. The MAC layer of the remote terminal and the sidelink relay follows the instruction information from the RRC layer about whether it is a sidelink relay discovery message between the remote terminal and another remote terminal, and the instruction information about whether it is a sidelink relay discovery message between the remote terminal and the network. The operation of selecting a discovery message transmission resource pool can be performed, and the operation of selecting the destination layer-2 ID and source layer-2 ID can be performed.

The transmitting terminal (remote terminal or sidelink relay) will not multiplex the MAC PDU containing the sidelink relay discovery message between the remote terminal and another remote terminal in the same transport block (TB) as the MAC PDU containing general sidelink data. You can.

(2) Option 2

A sidelink relay discovery message and a sidelink relay discovery request message can be transmitted and received using the format of a PC5 relay discovery message or a DCR message with relay discovery indication.

The sidelink radio bearer that transmits/receives the PC5 relay discovery message or DCR message with relay discovery indication can be configured as a new SL-SRB (sidelink signaling radio bearer). In other words, the sidelink radio bearer that transmits/receives sidelink relay discovery messages between a remote terminal and another remote terminal is different from the sidelink radio bearer SL-SRB4 that transmits/receives sidelink relay discovery messages between a remote terminal and the network. Can be set to SRB. A DCR message requesting establishment of a general sidelink direct connection between a remote terminal and another remote terminal may be configured to use SL-SRB0.

In cases where the sidelink relay and/or remote terminal support both sidelink relay discovery between the remote terminal and another remote terminal and sidelink relay discovery between the remote terminal and the network, the upper layer of the sidelink relay (e.g., ProSe layer, V2X layer, PC5-S layer), the upper layer of the remote terminal determines whether the sidelink discovery message to be transmitted to each RRC layer is a sidelink relay discovery between the remote terminal and another remote terminal or a sidelink between the remote terminal and the network. Information indicating whether it is a relay search can be transmitted. The RRC layer can transmit information indicating whether it is a sidelink relay search between a remote terminal and another remote terminal, and information indicating whether it is a sidelink relay search between a remote terminal and a network to the PDCP layer, RLC layer, and MAC layer. When information indicating whether sidelink relay discovery between the remote terminal and another remote terminal is transmitted from the upper layer of the transmitting terminal (remote terminal or sidelink relay) to the RRC layer, the RRC layer sends a new SL corresponding to the sidelink relay discovery message. -SRB can be set and the PDCP layer can be instructed to create a PDCP entity that can process the new SL-SRB. When information indicating whether the sidelink relay discovery between the remote terminal and the network is transmitted from the upper layer of the transmitting terminal (remote terminal or sidelink relay) to the RRC layer, the RRC layer sends SL-SRB4 corresponding to the sidelink relay discovery message. It can be set, and the PDCP layer can be instructed to create a PDCP entity that can process SL-SRB4. When an instruction is sent from the upper layer of the transmitting terminal that transmission of the sidelink relay discovery message between the remote terminal and other remote terminals is no longer required, the RRC layer instructs the PDCP layer to transmit the sidelink relay discovery message between the remote terminal and other remote terminals. An instruction to release the PDCP entity corresponding to the new SL-SRB created for this purpose can be sent. The PDCP entity that processes the new SL-SRB that receives the sidelink relay discovery message between a remote terminal and another remote terminal is the same as the PDCP entity that handles the SL-SRB4 that receives the sidelink relay discovery message between the remote terminal and the network. It can be created and released in this way.

In the case where the receiving terminal (sidelink relay or remote terminal) supports both sidelink relay discovery between the remote terminal and another remote terminal and sidelink relay discovery between the remote terminal and the network, the PDCP layer of the receiving terminal is different from that of the remote terminal. When it is determined that a sidelink relay discovery message between a remote terminal has been received or a sidelink relay discovery message between a remote terminal and a network has been received, the PDCP layer of the receiving terminal is connected to each upper layer (e.g., ProSe layer, V2X Information indicating whether the sidelink discovery message received is a sidelink relay discovery between a remote terminal and another remote terminal or a sidelink relay discovery between a remote terminal and a network may be transmitted to the layer (PC5-S layer).

The logical channel for transmitting and receiving sidelink relay discovery messages between a remote terminal and another remote terminal and the logical channel for transmitting and receiving sidelink relay discovery messages between a remote terminal and the network may be set differently. A logical channel configured differently can be used to distinguish between a sidelink relay discovery message between a remote terminal and another remote terminal and a sidelink relay discovery message between a remote terminal and a network. The MAC layer can select the corresponding logical channel according to the indication information from the RRC layer about whether it is a sidelink relay discovery message between a remote terminal and another remote terminal or a sidelink relay discovery message between a remote terminal and the network. The transmitting terminal (remote terminal or sidelink relay) is configured according to the sidelink relay discovery message instruction between the remote terminal and another remote terminal or the sidelink relay discovery message instruction between the remote terminal and the network transmitted by the RRC layer to the MAC layer. A sidelink discovery message can be transmitted through a logical channel. The receiving terminal (remote terminal or sidelink relay) receives the information through the logical channel corresponding to the sidelink relay discovery message between the remote terminal and another remote terminal or the logical channel corresponding to the sidelink relay discovery message between the remote terminal and the network. The sidelink discovery message can be determined and information indicating which relay discovery message it is can be transmitted to the upper layer.

The resource pool for transmitting sidelink relay discovery messages between a remote terminal and another remote terminal may be set as a discovery message transmission-only pool or as a general sidelink message transmission pool. When selecting a resource for transmitting a sidelink relay discovery message between a remote terminal and another remote terminal, the remote terminal and the sidelink relay can select a resource from the discovery message transmission dedicated pool if it is determined that a discovery message transmission dedicated pool is set, and the discovery message transmission dedicated pool can be selected. If it is determined that a dedicated message transmission pool is not set up, resources can be selected from the general sidelink message transmission pool.

When the remote terminal and the sidelink relay transmit and receive sidelink relay discovery messages between the remote terminal and other remote terminals, the destination layer is in the Layer-2 ID pool set for the sidelink relay discovery message between the remote terminal and other remote terminals. You can select -2 ID and/or source layer-2 ID. This Layer-2 ID pool can be set separately from the Layer-2 ID pool set for general sidelink communication purposes. The MAC layer of the remote terminal and the sidelink relay follows the instruction information from the RRC layer about whether it is a sidelink relay discovery message between the remote terminal and another remote terminal, and the instruction information about whether it is a sidelink relay discovery message between the remote terminal and the network. The operation of selecting a discovery message transmission resource pool can be performed, and the operation of selecting the destination layer-2 ID and source layer-2 ID can be performed.

The transmitting terminal (remote terminal or sidelink relay) will not multiplex the MAC PDU containing the sidelink relay discovery message between the remote terminal and another remote terminal in the same transport block (TB) as the MAC PDU containing general sidelink data. You can.

(3) Option 3

When a sidelink relay discovery message is transmitted and received using the format of DCR message with relay discovery indication, the sidelink radio bearer that transmits/receives the DCR message with relay discovery indication will be set to SL-SRB0 (sidelink signaling radio bearer 0). You can. The sidelink radio bearer that transmits/receives sidelink relay discovery messages between the remote terminal and the network can be configured as SL-SRB4. In the case where a sidelink relay discovery message between a remote terminal and another remote terminal is transmitted and received using the format of the PC5 relay discovery message, the sidelink radio bearer is an SL-SRB (SL-SRB4 or new SL-SRB) other than SL-SRB0. ) can be set.

A sidelink relay or remote terminal is a sidelink relay discovery message between a remote terminal and another remote terminal and is sent and received in the PC5 relay discovery message format. A sidelink relay discovery message between a remote terminal and another remote terminal is sent and received in the DCR message with relay discovery indication format. It may support at least one or a combination of transmission and reception, transmission and reception of a sidelink direct connection setup message between the remote terminal and another remote terminal, and transmission and reception of a sidelink relay discovery message between the remote terminal and the network. In each case, the processing of transmitted and received messages may be different at the RRC layer, PDCP layer, RLC layer, and MAC layer, so the upper layer of the transmitting terminal (sidelink relay or remote terminal) sends the PC5 relay discovery message to the RRC layer. Transmission instruction in format, DCR message with relay discovery indication as a sidelink relay discovery message between the remote terminal and other remote terminals, transmission instruction in format, transmission instruction for sidelink direct connection establishment message between the remote terminal and other remote terminals, remote terminal and network A sidelink relay discovery message transmission instruction can be transmitted between the two sides. The RRC layer can instruct the PDCP layer, RLC layer, and MAC layer what settings to apply according to the instruction information of the upper layer. The receiving terminal (sidelink relay or remote terminal) determines reception in the format of a PC5 relay discovery message, or determines reception in the format of a DCR message with relay discovery indication as a sidelink relay discovery message between the remote terminal and another remote terminal. When the terminal determines reception of a sidelink direct connection setup message or a sidelink relay discovery message between a remote terminal and the network, information about the received message can be transmitted to the upper layer. For example, the PDCP layer of the receiving terminal (sidelink relay or remote terminal) provides indication information to the upper layer (e.g., ProSe layer, V2X layer, PC5-S layer) about which case the received message corresponds to. It can be delivered.

When the PDCP layer of the transmitting terminal (sidelink relay or remote terminal) receives an instruction from the RRC layer indicating that a DCR with relay discovery indication message is being transmitted, it sets SL-SRB0 for DCR with relay discovery indication and transmits the PDCP corresponding to SL-SRB0. You can create entities. When an instruction is sent from the upper layer of the transmitting terminal that transmission of the sidelink relay discovery message between the remote terminal and other remote terminals in the DCR with relay discovery indication format is no longer necessary, the RRC layer tells the PDCP layer to An instruction to release the PDCP entity corresponding to SL-SRB0 created to transmit the sidelink relay discovery message can be sent. The PDCP entity that processes SL-SRB0, which receives the DCR with relay discovery indication as a sidelink relay discovery message between a remote terminal and another remote terminal, processes SL-SRB4, which receives a sidelink relay discovery message between a remote terminal and the network. It can be created and released in the same way as a PDCP entity.

A logical channel for transmitting and receiving a sidelink relay discovery message DCR with relay discovery indication between a remote terminal and another remote terminal may be set differently from a logical channel for transmitting and receiving a general DCR message. The logical channel for transmitting and receiving the DCR with relay discovery indication may be set differently from the logical channel for transmitting and receiving the PC5 relay discovery message. The logical channel for transmitting and receiving the DCR with relay discovery indication may be set differently from the logical channel for transmitting and receiving the sidelink relay discovery message between the remote terminal and the network. The MAC layer is in the DCR with relay discovery indication format as a sidelink relay discovery message between the remote terminal and another remote terminal from the RRC layer, or in the PC5 relay discovery format as a sidelink relay discovery message between the remote terminal and other remote terminals. The corresponding logical channel can be selected according to the indication information whether it is a general DCR message between the remote terminal and another remote terminal or a sidelink relay search message between the remote terminal and the network. The transmitting terminal (remote terminal or sidelink relay) is a sidelink relay discovery message between the remote terminal and another remote terminal delivered by the RRC layer to the MAC layer. It is a DCR with relay discovery indication or a sidelink relay between the remote terminal and another remote terminal. As a discovery message, a sidelink discovery message can be transmitted through the logical channels set for each according to the PC5 relay discovery instruction, the general DCR message instruction between the remote terminal and another remote terminal, or the sidelink relay discovery message instruction between the remote terminal and the network. . The receiving terminal (remote terminal or sidelink relay) is a sidelink relay discovery message between the remote terminal and another remote terminal, a logical channel corresponding to DCR with relay discovery indication, or a sidelink relay discovery message between the remote terminal and another remote terminal. The logical channel corresponding to PC5 relay discovery, the logical channel corresponding to a general DCR message between a remote terminal and another remote terminal, or the logical channel corresponding to a sidelink relay discovery message between a remote terminal and the network can be determined and sent to the upper layer. Information indicating what is the case can be conveyed.

The resource pool that transmits the DCR with relay discovery indication as a sidelink relay discovery message between a remote terminal and another remote terminal may be set as a discovery message transmission-only pool or a general sidelink message transmission pool. The remote terminal and sidelink relay is a sidelink relay discovery message between a remote terminal and another remote terminal. When selecting a resource for transmitting a DCR with relay discovery indication, if it is determined that a discovery message transmission dedicated pool is set, the resource is selected from the discovery message transmission dedicated pool. You can select, and if it is determined that a dedicated discovery message transmission pool is not set, you can select a resource from the general sidelink message transmission pool.

Remote terminal and sidelink relay is a sidelink relay discovery message between a remote terminal and another remote terminal. When transmitting and receiving a DCR with relay discovery indication, Layer- set for the purpose of a sidelink relay discovery message between a remote terminal and another remote terminal. 2 You can select the destination layer-2 ID and/or source layer-2 ID from the ID pool. This Layer-2 ID pool can be set separately from the Layer-2 ID pool used for DCR messages for general sidelink communication purposes. The MAC layer of the remote terminal and the sidelink relay is a sidelink relay discovery message between the remote terminal and other remote terminals from the RRC layer, indicating information about whether it is a DCR with relay discovery indication message, and sidelink relay between the remote terminal and other remote terminals. Indication information as to whether it is a PC5 relay discovery message as a discovery message, indication information as to whether it is a DCR message for the purpose of establishing a general direct connection between a remote terminal and another remote terminal, and indication as to whether it is a sidelink relay discovery message between a remote terminal and a network. Depending on the information, an operation can be performed to select a discovery message transmission resource pool, and an operation to select a destination layer-2 ID and a source layer-2 ID can be performed.

The transmitting terminal (remote terminal or sidelink relay) transmits the MAC PDU containing the DCR with relay discovery indication as a sidelink relay discovery message between the remote terminal and another remote terminal in the same TB (transport) as the MAC PDU containing general sidelink data. block) may not be multiplexed.

(4) Option 4

A sidelink relay discovery message and a sidelink relay discovery request message can be transmitted and received using the format of a PC5 relay discovery message or a DCR message with relay discovery indication. The sidelink radio bearer that transmits/receives the PC5 relay discovery message or DCR message with relay discovery indication can be configured as SL-SRB4 (sidelink signaling radio bearer 4). In other words, the sidelink radio bearer that transmits/receives sidelink relay discovery messages between a remote terminal and another remote terminal is the same as the sidelink radio bearer that transmits/receives sidelink relay discovery messages between a remote terminal and the network. Can be set to SRB4. A DCR message requesting establishment of a general sidelink direct connection between a remote terminal and another remote terminal may be configured to use SL-SRB0.

A sidelink relay or remote terminal is a sidelink relay discovery message between a remote terminal and another remote terminal and is sent and received in the PC5 relay discovery message format. A sidelink relay discovery message between a remote terminal and another remote terminal is sent and received in the DCR message with relay discovery indication format. It may support at least one or a combination of transmission and reception, transmission and reception of a sidelink direct connection setup message between the remote terminal and another remote terminal, and transmission and reception of a sidelink relay discovery message between the remote terminal and the network. In each case, the processing of transmitted and received messages may be different at the RRC layer, PDCP layer, RLC layer, and MAC layer, so the upper layer of the transmitting terminal (sidelink relay or remote terminal) sends the PC5 relay discovery message to the RRC layer. Transmission instruction in format, DCR message with relay discovery indication as a sidelink relay discovery message between the remote terminal and other remote terminals, transmission instruction in format, transmission instruction for sidelink direct connection establishment message between the remote terminal and other remote terminals, remote terminal and network A sidelink relay discovery message transmission instruction can be transmitted between the two sides. The RRC layer can instruct the PDCP layer, RLC layer, and MAC layer what settings to apply according to the instruction information of the upper layer. The receiving terminal (sidelink relay or remote terminal) determines reception in the format of a PC5 relay discovery message, or determines reception in the format of a DCR message with relay discovery indication as a sidelink relay discovery message between the remote terminal and another remote terminal. When the terminal determines reception of a sidelink direct connection setup message or a sidelink relay discovery message between a remote terminal and the network, information about the received message can be transmitted to the upper layer. For example, the PDCP layer of the receiving terminal (sidelink relay or remote terminal) provides indication information to the upper layer (e.g., ProSe layer, V2X layer, PC5-S layer) about which case the received message corresponds to. It can be delivered.

When the PDCP layer of the transmitting terminal (sidelink relay or remote terminal) receives an instruction from the RRC layer indicating that a DCR with relay discovery indication message is being transmitted, it sets SL-SRB4 for DCR with relay discovery indication and transmits the PDCP corresponding to SL-SRB4. You can create entities. When an instruction is sent from the upper layer of the transmitting terminal that transmission of the sidelink relay discovery message between the remote terminal and other remote terminals in the DCR with relay discovery indication format is no longer necessary, the RRC layer tells the PDCP layer to An instruction to release the PDCP entity corresponding to the SL-SRB4 created for transmitting the sidelink relay discovery message can be sent. The PDCP entity that processes the SL-SRB4 that receives the DCR with relay discovery indication as a sidelink relay discovery message between the remote terminal and another remote terminal processes the SL-SRB4 that receives the sidelink relay discovery message between the remote terminal and the network. It can be created and released in the same way as a PDCP entity.

The logical channel that transmits and receives sidelink relay discovery messages between a remote terminal and other remote terminals, DCR with relay discovery indication, is set differently from the logical channel that transmits and receives PC5 relay discovery messages between a remote terminal and other remote terminals. It can be. The MAC layer is in the DCR with relay discovery indication format as a sidelink relay discovery message between the remote terminal and another remote terminal from the RRC layer, or in the PC5 relay discovery format as a sidelink relay discovery message between the remote terminal and other remote terminals. The corresponding logical channel can be selected according to the indication information whether it is a general DCR message between the remote terminal and another remote terminal or a sidelink relay search message between the remote terminal and the network. The transmitting terminal (remote terminal or sidelink relay) is a sidelink relay discovery message between the remote terminal and another remote terminal delivered by the RRC layer to the MAC layer. It is a DCR with relay discovery indication or a sidelink relay between the remote terminal and another remote terminal. As a discovery message, a sidelink discovery message can be transmitted through the logical channels set for each according to the PC5 relay discovery instruction, the general DCR message instruction between the remote terminal and another remote terminal, or the sidelink relay discovery message instruction between the remote terminal and the network. . The receiving terminal (remote terminal or sidelink relay) is a sidelink relay discovery message between the remote terminal and another remote terminal, a logical channel corresponding to DCR with relay discovery indication, or a sidelink relay discovery message between the remote terminal and another remote terminal. The logical channel corresponding to PC5 relay discovery, the logical channel corresponding to a general DCR message between a remote terminal and another remote terminal, or the logical channel corresponding to a sidelink relay discovery message between a remote terminal and the network can be determined and sent to the upper layer. Information indicating what is the case can be conveyed.

The resource pool that transmits the DCR with relay discovery indication as a sidelink relay discovery message between a remote terminal and another remote terminal may be set as a discovery message transmission-only pool or a general sidelink message transmission pool. The remote terminal and sidelink relay is a sidelink relay discovery message between a remote terminal and another remote terminal. When selecting a resource for transmitting a DCR with relay discovery indication, if it is determined that a discovery message transmission dedicated pool is set, the resource is selected from the discovery message transmission dedicated pool. You can select, and if it is determined that a dedicated discovery message transmission pool is not set, you can select a resource from the general sidelink message transmission pool.

Remote terminal and sidelink relay is a sidelink relay discovery message between a remote terminal and another remote terminal. When transmitting and receiving a DCR with relay discovery indication, Layer- set for the purpose of a sidelink relay discovery message between a remote terminal and another remote terminal. 2 You can select the destination layer-2 ID and/or source layer-2 ID from the ID pool. This Layer-2 ID pool can be set separately from the Layer-2 ID pool used for DCR messages for general sidelink communication purposes. The MAC layer of the remote terminal and the sidelink relay is a sidelink relay discovery message between the remote terminal and other remote terminals from the RRC layer, indicating information about whether it is a DCR with relay discovery indication message, and sidelink relay between the remote terminal and other remote terminals. Indication information as to whether it is a PC5 relay discovery message as a discovery message, indication information as to whether it is a DCR message for the purpose of establishing a general direct connection between a remote terminal and another remote terminal, and indication as to whether it is a sidelink relay discovery message between a remote terminal and a network. Depending on the information, an operation can be performed to select a discovery message transmission resource pool, and an operation to select a destination layer-2 ID and a source layer-2 ID can be performed.

The transmitting terminal (remote terminal or sidelink relay) transmits the MAC PDU containing the DCR with relay discovery indication as a sidelink relay discovery message between the remote terminal and another remote terminal in the same TB (transport) as the MAC PDU containing general sidelink data. block) may not be multiplexed.

(5) Option 5

A sidelink relay discovery message and a sidelink relay discovery request message can be transmitted and received using the format of a PC5 relay discovery message or a DCR message with relay discovery indication. The sidelink radio bearer that transmits/receives the PC5 relay discovery message or DCR message with relay discovery indication can be configured as a new SL-SRB (sidelink signaling radio bearer). The sidelink radio bearer that transmits/receives sidelink relay discovery messages between the remote terminal and the network can be configured as SL-SRB4. A DCR message requesting establishment of a general sidelink direct connection between a remote terminal and another remote terminal may be configured to use SL-SRB0.

A sidelink relay or remote terminal is a sidelink relay discovery message between a remote terminal and another remote terminal and is sent and received in the PC5 relay discovery message format. A sidelink relay discovery message between a remote terminal and another remote terminal is sent and received in the DCR message with relay discovery indication format. It may support at least one or a combination of transmission and reception, transmission and reception of a sidelink direct connection setup message between the remote terminal and another remote terminal, and transmission and reception of a sidelink relay discovery message between the remote terminal and the network. In each case, the processing of transmitted and received messages may be different at the RRC layer, PDCP layer, RLC layer, and MAC layer, so the upper layer of the transmitting terminal (sidelink relay or remote terminal) sends the PC5 relay discovery message to the RRC layer. Transmission instruction in format, DCR message with relay discovery indication as a sidelink relay discovery message between the remote terminal and other remote terminals, transmission instruction in format, transmission instruction for sidelink direct connection establishment message between the remote terminal and other remote terminals, remote terminal and network A sidelink relay discovery message transmission instruction can be transmitted between the two sides. The RRC layer can instruct the PDCP layer, RLC layer, and MAC layer what settings to apply according to the instruction information of the upper layer. The receiving terminal (sidelink relay or remote terminal) determines reception in the format of a PC5 relay discovery message, or determines reception in the format of a DCR message with relay discovery indication as a sidelink relay discovery message between the remote terminal and another remote terminal. When the terminal determines reception of a sidelink direct connection setup message or a sidelink relay discovery message between a remote terminal and the network, information about the received message can be transmitted to the upper layer. For example, the PDCP layer of the receiving terminal (sidelink relay or remote terminal) provides indication information to the upper layer (e.g., ProSe layer, V2X layer, PC5-S layer) about which case the received message corresponds to. It can be delivered.

When the PDCP layer of the transmitting terminal (sidelink relay or remote terminal) receives an instruction from the RRC layer indicating that a DCR with relay discovery indication message is being transmitted, it sets a new SL-SRB for DCR with relay discovery indication and sets the new SL-SRB corresponding to the new SL-SRB. A PDCP transmitting entity can be created. When an instruction is sent from the upper layer of the transmitting terminal that transmission of the sidelink relay discovery message between the remote terminal and other remote terminals in the DCR with relay discovery indication format is no longer necessary, the RRC layer tells the PDCP layer to An instruction to release the PDCP entity corresponding to the new SL-SRB created for transmitting the sidelink relay discovery message can be sent. The PDCP entity that processes the new SL-SRB that receives the DCR with relay discovery indication as a sidelink relay discovery message between the remote terminal and another remote terminal is the new SL-SRB that receives the sidelink relay discovery message between the remote terminal and the network. It can be created and released in the same way as the PDCP entity that handles it.

The logical channel that transmits and receives sidelink relay discovery messages between a remote terminal and other remote terminals, DCR with relay discovery indication, is set differently from the logical channel that transmits and receives PC5 relay discovery messages between a remote terminal and other remote terminals. It can be. The MAC layer is in the DCR with relay discovery indication format as a sidelink relay discovery message between the remote terminal and another remote terminal from the RRC layer, or in the PC5 relay discovery format as a sidelink relay discovery message between the remote terminal and other remote terminals. The corresponding logical channel can be selected according to the indication information whether it is a general DCR message between the remote terminal and another remote terminal or a sidelink relay search message between the remote terminal and the network. The transmitting terminal (remote terminal or sidelink relay) is a sidelink relay discovery message between the remote terminal and another remote terminal delivered by the RRC layer to the MAC layer. It is a DCR with relay discovery indication or a sidelink relay between the remote terminal and another remote terminal. As a discovery message, a sidelink discovery message can be transmitted through the logical channels set for each according to the PC5 relay discovery instruction, the general DCR message instruction between the remote terminal and another remote terminal, or the sidelink relay discovery message instruction between the remote terminal and the network. . The receiving terminal (remote terminal or sidelink relay) is a sidelink relay discovery message between the remote terminal and another remote terminal, a logical channel corresponding to DCR with relay discovery indication, or a sidelink relay discovery message between the remote terminal and another remote terminal. The logical channel corresponding to PC5 relay discovery, the logical channel corresponding to a general DCR message between a remote terminal and another remote terminal, or the logical channel corresponding to a sidelink relay discovery message between a remote terminal and the network can be determined and sent to the upper layer. Information indicating what is the case can be conveyed.

The resource pool that transmits the DCR with relay discovery indication as a sidelink relay discovery message between a remote terminal and another remote terminal may be set as a discovery message transmission-only pool or a general sidelink message transmission pool. The remote terminal and sidelink relay is a sidelink relay discovery message between a remote terminal and another remote terminal. When selecting a resource for transmitting a DCR with relay discovery indication, if it is determined that a discovery message transmission dedicated pool is set, the resource is selected from the discovery message transmission dedicated pool. You can select, and if it is determined that a dedicated discovery message transmission pool is not set, you can select a resource from the general sidelink message transmission pool.

Remote terminal and sidelink relay is a sidelink relay discovery message between a remote terminal and another remote terminal. When transmitting and receiving a DCR with relay discovery indication, Layer- set for the purpose of a sidelink relay discovery message between a remote terminal and another remote terminal. 2 You can select the destination layer-2 ID and/or source layer-2 ID from the ID pool. This Layer-2 ID pool can be set separately from the Layer-2 ID pool used for DCR messages for general sidelink communication purposes. The MAC layer of the remote terminal and the sidelink relay is a sidelink relay discovery message between the remote terminal and other remote terminals from the RRC layer, indicating information about whether it is a DCR with relay discovery indication message, and sidelink relay between the remote terminal and other remote terminals. Indication information as to whether it is a PC5 relay discovery message as a discovery message, indication information as to whether it is a DCR message for the purpose of establishing a general direct connection between a remote terminal and another remote terminal, and indication as to whether it is a sidelink relay discovery message between a remote terminal and a network. Depending on the information, an operation can be performed to select a discovery message transmission resource pool, and an operation to select a destination layer-2 ID and a source layer-2 ID can be performed.

The transmitting terminal (remote terminal or sidelink relay) transmits the MAC PDU containing the DCR with relay discovery indication as a sidelink relay discovery message between the remote terminal and another remote terminal in the same TB (transport) as the MAC PDU containing general sidelink data. block) may not be multiplexed.

According to various embodiments of the present invention, when transmitting and receiving a DCR with relay discovery indication as a sidelink relay discovery message between a remote terminal and another remote terminal, the sending terminal (sidelink relay or remote terminal) performs general sidelink direct communication. The destination layer-2 ID and source layer-2 ID can be selected from the same Layer-2 ID poo as the Layer-2 ID pool used in the DCR message. The MAC layer of the transmitting terminal (remote terminal, sidelink relay) is a sidelink relay discovery message between the remote terminal and another remote terminal from the RRC layer, and general sidelink direct communication is based on information indicating whether it is a DCR with relay discovery indication message. The operation of selecting the destination layer-2 ID and source layer-2 ID can be performed from the Layer-2 ID pool used in the DCR message. In one embodiment, the transmitting terminal (remote terminal or sidelink relay) uses the same Layer2-ID pool as the general DCR message for the MAC PDU containing the DCR with relay discovery indication as a sidelink relay discovery message between the remote terminal and another remote terminal. When transmitting a MAC PDU by selecting the destination layer-2 ID and source layer-2 ID, the transmitting terminal transmits the MAC PDU including the DCR with relay discovery indication in the same TB (transport) as the MAC PDU including general sidelink data. block) may not be multiplexed. In another embodiment, the transmitting terminal (remote terminal or sidelink relay) uses the same Layer2-ID pool as the general DCR message for the MAC PDU containing the DCR with relay discovery indication as a sidelink relay discovery message between the remote terminal and another remote terminal. When transmitting a MAC PDU by selecting the destination layer-2 ID and source layer-2 ID, the transmitting terminal transmits the MAC PDU including the DCR with relay discovery indication to the MAC PDU including general sidelink data, that is, DCR with relay. The same destination layer-2 ID as the MAC PDU containing the discovery indication can be multiplexed in the same TB (transport block) as the selected MAC PDU.

According to various embodiments of the present invention, when transmitting a PC5 relay discovery message or DCR message with relay discovery indication as a sidelink relay discovery message between a remote terminal and another remote terminal, the transmitting terminal (sidelink relay or remote terminal) has MAC The operation of selecting the destination layer-2 ID to configure a PDU and selecting the logical channel(s) to be included in the MAC PDU is shown in [Table 1] below.

Selection of logical channels
The MAC entity shall for each SCI corresponding to a new transmission:
1> if sl-BWP-DiscPoolConfig or sl-BWP-DiscPoolConfigCommon is configured according to RRC:
2> if the new transmission is associated with a sidelink grant in sl-DiscTxPoolSelected or sl-DiscTxPoolScheduling configured in sl-BWP-DiscPoolConfig or sl-BWP-DiscPoolConfigCommon :

One embodiment: When a dedicated resource pool for sidelink relay discovery message purpose is set and transmission resources are allocated from this pool, Layer-2 is set for sidelink relay discovery purpose for PC5 relay discovery message or DCR message with relay discovery indication. When selecting destination layer-2 ID from ID pool
3> select a Destination associated with sidelink discovery, having at least one of the logical channel with the highest priority, among the logical channels that satisfy all the following conditions for the SL grant associated to the SCI:
4> SL data is available for transmission; and
4> SBj > 0, in case there is any logical channel having SBj >0; and
4> sl-configuredGrantType1Allowed , if configured, is set to true in case the SL grant is a Configured Grant Type 1; and
4> sl-AllowedCG-List , if configured, includes the configured grant index associated to the SL grant;

One embodiment: When a dedicated resource pool for sidelink relay discovery message purpose is set and transmission resources are allocated from this pool, the destination layer is in the Layer-2 ID pool for general sidelink direct communication for DCR message with relay discovery indication. -2 When selecting ID
3> select a Destination associated with DCR for sidelink discovery as specified in upper layer specification (or a Destination associated with one of unicast, groupcast and broadcast for DCR with relay discovery indication), having at least one of the logical channel with the highest priority , among the logical channels that satisfy all the following conditions for the SL grant associated to the SCI:
4> SL data is available for transmission; and
4> SBj > 0, in case there is any logical channel having SBj >0; and
4> sl-configuredGrantType1Allowed , if configured, is set to true in case the SL grant is a Configured Grant Type 1; and
4> sl-AllowedCG-List , if configured, includes the configured grant index associated to the SL grant;

(Operation of selecting a destination layer-2 ID and selecting a logical channel when the transmitting terminal configures a MAC PDU for general sidelink direct communication)
3> select a Destination associated with one of unicast, groupcast and broadcast (excluding the Destination(s) associated with sidelink discovery) , having at least one of the MAC CE and the logical channel with the highest priority, among the logical channels that satisfy all the following conditions and MAC CE(s), if any, for the SL grant associated to the SCI:
4> SL data is available for transmission; and
4> SBj > 0, in case there is any logical channel having SBj >0; and
4> sl-configuredGrantType1Allowed , if configured, is set to true in case the SL grant is a Configured Grant Type 1; and
4> sl-AllowedCG-List , if configured, includes the configured grant index associated to the SL grant; and
4> sl-HARQ-FeedbackEnabled is set to disabled, if PSFCH is not configured for the SL grant associated to the SCI.

According to various embodiments of the present invention, when a sidelink relay and a remote terminal transmit a sidelink relay discovery message between the remote terminal and another remote terminal, where the sidelink relay discovery message is a PC5 relay discovery message or a DCR message with relay discovery indication, and the base station can schedule sidelink relay discovery message transmission resources to the sidelink relay and remote terminal. The sidelink relay and the remote terminal may transmit a sidelink buffer status report (SL-BSR) message to the base station to request transmission resources for transmitting a sidelink relay discovery message. As an embodiment, the SidelinkUEInformationNR message may include SL-TxResourceReqListCommRelay information for a sidelink relay discovery message between a remote terminal and another remote terminal, and when the sidelink relay and the remote terminal report this information to the base station, SL-BSR The destination index included in the message may include the information shown in [Table 2] below for the sidelink relay discovery message between the remote terminal and another remote terminal.

SL destination identity associated to same destination reported in SL-TxResourceReqList , SL-TxResourceReqListDisc and SL-TxResourceReqListCommRelay , SL-TXResourceRequestListU2URelay , if present. The value is indexed sequentially from "0" in the same ascending order of SL destination identity in SL-TxResourceReqList , SL-TxResourceReqListDisc and SL-TxResourceReqListCommRelay , SL-TXResourceRequestListU2URelay as specified in TS 38.331. When multiple lists are reported, the value is indexed sequentially across all the lists in the same order as presented in SidelinkUEInformaitonNR message;

As another embodiment, if the SidelinkUEInformationNR message includes SL-TXResourceRequestListU2URelay information for a sidelink relay discovery message between a remote terminal and another remote terminal, the destination index included in the SL-BSR message is a sidelink relay discovery message between the remote terminal and another remote terminal. The relay discovery message may include the information in [Table 3] below.

SL destination identity associated to same destination reported in SL-TxResourceReqList , SL-TxResourceReqListDisc and SL-TxResourceReqListCommRelay , SL-TXResourceRequestListU2URelay , if present. The value is indexed sequentially from "0" in the same ascending order of SL destination identity in SL-TxResourceReqList , SL-TxResourceReqListDisc and SL-TxResourceReqListCommRelay , SL-TXResourceRequestListU2URelay as specified in TS 38.331. When multiple lists are reported, the value is indexed sequentially across all the lists in the same order as presented in SidelinkUEInformaitonNR message;

FIG. 8 is a diagram illustrating an operation in which a remote terminal and a sidelink relay transmit a sidelink relay discovery message between the remote terminal and another remote terminal according to an embodiment of the present disclosure.

Referring to FIG. 8, the remote terminal and the sidelink relay can support both sidelink relay discovery between the remote terminal and another remote terminal and sidelink relay discovery between the remote terminal and the network. The remote terminal and the sidelink relay may transmit a sidelink relay discovery message between the remote terminal and another remote terminal or a sidelink relay discovery message between the remote terminal and the network. The remote terminal and the sidelink relay process instructions as to whether the message to be transmitted is a sidelink relay discovery message between the remote terminal and another remote terminal or a sidelink relay discovery message between the remote terminal and the network, and in each case, The operation of configuring and transmitting a sidelink relay discovery message can be processed.

The transmitting terminal (sidelink relay or remote terminal) may determine whether transmission of the sidelink relay discovery message is necessary in step 801. The determination of whether sidelink relay discovery message transmission is necessary is determined by determining whether transmission of a sidelink relay discovery message between a remote terminal and another remote terminal is necessary, conditions for transmitting a sidelink relay discovery message between a remote terminal and another remote terminal, and discovery message transmission. An operation to determine whether the transmission conditions are satisfied, whether transmission of a sidelink relay discovery message between the remote terminal and the network is necessary, whether the sidelink relay discovery message transmission conditions between the remote terminal and the network are set and the discovery message transmission conditions are satisfied, etc. may include. The upper layer of the transmitting terminal (e.g., ProSe layer, V2X layer, PC5-S layer) determines in steps 803 to 801 whether to transmit a sidelink relay discovery message between the remote terminal and another remote terminal or to transmit a sidelink relay discovery message between the remote terminal and the remote terminal. Information indicating whether to transmit a sidelink relay discovery message between networks can be transmitted to the RRC layer. If it is determined in step 805 that the transmission of the sidelink relay discovery message indicates transmission of the sidelink relay discovery message between the remote terminal and another remote terminal, the RRC layer of the transmitting terminal transmits the sidelink relay between the remote terminal and the other remote terminal in step 807. SL-SRB can be set for transmission of discovery messages. The SL-SRB configuration for transmitting a sidelink relay discovery message between a remote terminal and another remote terminal may correspond to at least one of methods 1 to 5. In step 809, the RRC layer of the transmitting terminal transmits information such as entity settings, logical channel settings, and transmission resource pool settings for transmitting sidelink relay discovery messages between the remote terminal and other remote terminals to the PDCP layer, RLC layer, and MAC layer. You can. The operation of the PDCP layer, RLC layer, and MAC layer that processes sidelink relay discovery message transmission between a remote terminal and another remote terminal based on the information of the RRC layer may correspond to at least one of methods 1 to 5.

If the transmitting terminal determines in step 805 that the indication information transmitted to the RRC layer by the upper layer of the transmitting terminal indicates transmission of a sidelink relay discovery message between the remote terminal and the network, the RRC layer of the transmitting terminal transmits a sidelink relay discovery message between the remote terminal and the network in step 811. You can set SL-SRB4 configured for transmitting sidelink relay discovery messages between. In step 813, the RRC layer of the transmitting terminal can transmit information such as entity settings, logical channel settings, and transmission resource pool settings for transmitting sidelink relay discovery messages between the remote terminal and the network to the PDCP layer, RLC layer, and MAC layer. . The PDCP layer, RLC layer, and MAC layer of the transmitting terminal can process the transmission of a sidelink relay discovery message between the remote terminal and the network based on the information of the RRC layer. In the embodiment of FIG. 8, processing for transmission of a general sidelink direct communication connection setup message in addition to the sidelink relay discovery message or traffic transmission transmitted and received in general sidelink direct communication is not shown, but general processing is performed from the upper layer of the transmitting terminal to the RRC layer. Instructions for sidelink direct communication connection setup messages or instructions for traffic transmitted and received in general sidelink direct communication can be transmitted, and the RRC layer of the transmitting terminal can transmit settings for the PDCP layer, RLC layer, and MAC layer to each layer. there is.

FIG. 9 is a diagram illustrating an operation in which a remote terminal and a sidelink relay receive a sidelink relay discovery message between a remote terminal and another remote terminal according to an embodiment of the present disclosure.

Referring to FIG. 9, the remote terminal and the sidelink relay can support both sidelink relay discovery between the remote terminal and another remote terminal and sidelink relay discovery between the remote terminal and the network. The remote terminal and the sidelink relay may receive a sidelink relay discovery message between the remote terminal and another remote terminal or a sidelink relay discovery message between the remote terminal and the network. The remote terminal and the sidelink relay process a judgment as to whether the received message is a sidelink relay discovery message between the remote terminal and another remote terminal or a sidelink relay discovery message between the remote terminal and the network, and in each case, An operation may be performed to transmit information indicating which sidelink relay discovery message is to the upper layer (eg, ProSe layer, V2X layer, PC5-S layer) of the receiving terminal. FIG. 9 illustrates the operation of a sidelink relay or a receiving PDCP entity of a remote terminal as an example.

The receiving terminal (sidelink relay or remote terminal) may receive a PDCP PDU including a sidelink relay discovery message in step 901. The receiving terminal may determine in step 903 whether the received PDCP PDU corresponds to the SL-SRB configured for the sidelink relay discovery message between the remote terminal and another remote terminal. SL-SRB configuration for a sidelink relay discovery message between a remote terminal and another remote terminal may correspond to at least one of methods 1 to 5. If it is determined in step 903 that the received PDCP PDU corresponds to the SL-SRB set for the sidelink relay discovery message between the remote terminal and another remote terminal, the PDCP layer entity of the receiving terminal is different from the remote terminal in step 905. The PDCP SDU received along with an indicator indicating that it is a sidelink relay discovery message between remote terminals may be delivered to a higher layer (e.g., ProSe layer, V2X layer, PC5-S layer). According to the determination in step 903, if the received PDCP PDU is not received from the SL-SRB corresponding to the sidelink relay discovery message between the remote terminal and another remote terminal, the receiving terminal determines that the PDCP PDU received in step 907 is connected to the remote terminal and the network. It can be determined whether it corresponds to SL-SRB4, which is set for the purpose of sidelink relay discovery messages. If the receiving terminal determines that the received PDCP PDU corresponds to SL-SRB4 set for the sidelink relay discovery message between the remote terminal and the network, it receives it with an indicator indicating that it is a sidelink relay discovery message between the remote terminal and the network in step 909. The PDCP SDU can be delivered to a higher layer (e.g., ProSe layer, V2X layer, PC5-S layer). If it is determined in step 907 that the received PDCP PDU does not correspond to SL-SRB4 set for the sidelink relay discovery message between the remote terminal and the network, the receiving terminal selects the SRB or DRB (data) on which the PDCP PDU was received in step 911. The received packet can be judged and processed according to the radio bearer, and the information of the processed packet and PDCP SDU can be delivered to the upper layer (e.g., ProSe layer, V2X layer, PC5-S layer). The PDCP PDU that can be processed in step 911 may include a general sidelink direct communication connection establishment message or traffic transmitted and received in general sidelink direct communication.

FIG. 10 is a diagram illustrating transmission and/or reception of a side link relay discovery message according to an embodiment.

Referring to FIG. 10, a wireless communication system according to an embodiment includes a first UE (1001), a second UE (1002), a first sidelink relay (1003), and/or a second sidelink relay (1004). can do.

According to one embodiment, in step 1010, the first UE 1001 and/or the second UE 1002 provide a service provided by sidelink relays (e.g., UE-to-UE relays) 1003 and 1004. You may be granted permission to use it. Sidelink relays 1003 and 1004 may be authorized to provide services that relay traffic between UEs. Authorization for UEs 1001, 1002 and/or sidelink relays 1003, 1004 is performed when UEs 1001, 1002 and/or sidelink relays 1003, 1004 are registered with the network. It can be.

According to one embodiment, in step 1011, the first UE (1001) may establish unicast communication with the second UE (1002). Unicast communication may be performed directly between the first UE 1001 and the second UE 1002, or may be performed using at least one of the sidelink relays 1003 and 1004. In one embodiment, the first UE 1001 may broadcast a Direct Communication Request with relay indication. A broadcasted message (eg, Direct Communication Request with relay indication) may be received by the first sidelink relay 1003 and/or the second sidelink relay 1004. Additionally, a broadcast message (eg, Direct Communication Request with relay indication) may be received by the second UE (1002).

According to one embodiment, in step 1012, the first sidelink relay 1003 and/or the second sidelink relay 1004 may determine whether to participate in the procedure. The first sidelink relay 1003 and/or the second sidelink relay 1004 may broadcast a Direct Communication Request message without relay indication. The first sidelink relay 1003 and/or the second sidelink relay 1004 include first UE (1001) identification information, second UE (1002) identification information, and/or the Direct Communication Request message without relay indication message. The sidelink relay may include its own identification information.

According to one embodiment, in step 1013, the second UE 1002 may receive Direct Communication Requests from the first sidelink relay 1003 and the second sidelink relay 1004. If the second UE (1002) is within a communication range with the first UE (1001), the second UE (1002) may directly receive a Direct Communication Request message from the first UE (1001).

According to one embodiment, in step 1014, the second UE (1002) may select the first sidelink relay (1003) and reply to the Direct Communication Accept message through the first sidelink relay (1003). You can. When the second UE (1002) receives a Direct Communication Request from the first UE (1001), the second UE (1002) sets up a direct communication link by sending a Direct Communication Accept message directly to the first UE (1001). You can select .

According to one embodiment, in step 1015, the first UE 1001 may receive a Direct Communication Accept message from the first sidelink relay 91003. The first UE (1001) determines the path according to the policy and signal strength, that is, through which side link relay to set up a communication link with the second UE (1002) or to set up a direct communication link with the second UE (1002). You can choose whether or not.

According to one embodiment, in the case of a Layer 3 UE-to-UE relay case in step 1016a, the first UE 1001 and the second UE 1002 may complete communication link setup.

According to one embodiment, in the case of a Layer 2 UE-to-UE relay case in step 1016b, the source UE and target UE can set up an end-to-end PC5 link through relay. The first UE (1001) may transmit a unicast E2E Direct Communication Request message to the second UE (1002) through the selected first sidelink relay (1003). The second UE (1002) may transmit a unicast E2E Direct Communication Accept message to the first UE (1001) through the first sidelink relay (1003).

According to various embodiments of the present disclosure, various messages transmitted and/or received from the source remote terminal, target remote terminal, and/or sidelink relay may be processed as a sidelink relay discovery message.

For example, the Direct Communication Request with relay_indication message transmitted by the remote terminal, that is, the DCR with relay discovery indication message (hereinafter, the first message), may be processed as a sidelink relay discovery message.

For example, in addition to the DCR with relay discovery indication message, the sidelink relay that received the DCR with relay discovery indication message sent by the source remote terminal forwards it to the target remote terminal. Direct Communication Request with Relay UE info (e.g., Relay UE ID) The message (hereinafter referred to as the second message) may be processed as a side link relay discovery message.

For example, based on the Direct Communication Request with Relay UE info delivered by the sidelink relay, a sidelink relay that provides a connection to the source remote terminal is selected and a Direct Communication Accept with Relay UE info message (hereinafter referred to as , third message) may be processed as a side link relay discovery message.

For example, the Direct Communication Accept with Relay UE info message (hereinafter referred to as the fourth message) transmitted by the sidelink relay that has received the Direct Communication Accept with Relay UE info message from the target remote terminal to the source remote terminal is a sidelink relay discovery message. It can be processed as .

For example, DCR with relay with discovery indication message (first message), Direct communication Accept with Relay UE info message (second message) transmitted by the sidelink relay to the target remote terminal, Direct Communication Accept transmitted to the sidelink relay At least one or a combination of the with Relay UE info (third message) and the Direct Communication Accept with Relay UE info message (fourth message) transmitted to the source remote terminal may be processed as a sidelink relay discovery message.

According to one embodiment, when the Direct Communication Request with Relay UE info (e.g., Relay UE ID) message (second message) is processed as a sidelink relay discovery message, Direct Communication Request with Relay UE info (e.g., Relay UE ID ) message (second message) corresponds to a message transmitted before sidelink security setting, such as the DCR message with relay discovery indication message, so the ciphering function or integrity protection check and verification check functions are required at the PDCP layer. It may be transmitted and/or received using a redundant sidelink signaling bearer (SL-SRB).

For example, the Direct Communication Request with Relay UE info message is a SL-SRB (e.g., SL-SRB4 or PDCP layer where the PDCP layer ciphering function/integrity protection check and verification check functions are not applied), such as the DCR message with relay discovery indication message. Can be transmitted and/or received using the PDCP layer (SL-SRB0, to which the ciphering function/integrity protection check and verification check functions are not applied, or the new SL-SRB, to which the PDCP layer ciphering function/integrity protection check and verification check functions are not applicable) .

According to one embodiment, when the Communication Accept with Relay UE info message is processed as a sidelink relay discovery message, it is necessary to apply the PDCP layer ciphering function/integrity protection check and verification check function to the Communication Accept with Relay UE info message. If not present, the Communication Accept with Relay UE info message can be transmitted and received using the sidelink signaling bearer (SL-SRB), which does not require ciphering or integrity protection check and verification check functions at the PDCP layer. .

For example, the Direct Communication Accept with Relay UE info message is a SL-SRB (e.g., SL-SRB4 or PDCP layer where the PDCP layer ciphering function/integrity protection check and verification check functions are not applied), such as the DCR message with relay discovery indication message. Can be transmitted and/or received using the PDCP layer (SL-SRB0, to which the ciphering function/integrity protection check and verification check functions are not applied, or the new SL-SRB, to which the PDCP layer ciphering function/integrity protection check and verification check functions are not applicable) .

According to one embodiment, when the Communication Accept with Relay UE info message is processed as a sidelink relay discovery message, the transmission time of the Communication Accept with Relay UE info message is security for the unicast sidelink between the sidelink relay and the target remote terminal. This may apply after the establishment procedure is completed or after the security establishment procedure is completed for the unicast sidelink between the sidelink relay and the source remote terminal. Accordingly, the PDCP layer ciphering function/integrity protection check and verification check functions may need to be applied to the Communication Accept with Relay UE info message depending on the security settings. Therefore, the Communication Accept with Relay UE info message is transmitted and/or using a sidelink signaling bearer (SL-SRB) to which the ciphering function or integrity protection check and verification check functions can be applied in the PDCP layer. or may be received.

For example, the Direct Communication Accept with Relay UE info message is SL-SRB2 set to apply the PDCP layer ciphering function/integrity protection check and verification check function, or SL-SRB2 set to apply the PDCP layer ciphering function/integrity protection check and verification check function. -Can be transmitted and/or received using SRB4 or the new SL-SRB configured to apply the PDCP layer ciphering function/integrity protection check and verification check function.

According to one embodiment, SL-SRB2 may be defined as in [Table 4]. In [Table 4], the parameters specified for unicast of NR sidelink communication used for sidelink signaling radio bearer of protected PC5-S messages except Direct Link Security Mode Complete and ProSe Direct Link Security Mode Complete can be described. . The SL-SRB using the SCCH configuration related to [Table 4] may be referred to or named as SL-SRB2.

Name Value Semantics description Ver. PDCP configuration >t-Reordering Undefined Selected by the receiving UE, up to UE implementation >pdcp-SN-Size 12 RLC configuration A.M.R.C. >sn-FieldLength 12 >t-Reassembly Undefined Selected by the receiving UE, up to UE implementation >t-PollRetransmit Undefined Selected by the transmitting UE, up to UE implementation >pollPDU Undefined Selected by the transmitting UE, up to UE implementation >pollByte Undefined Selected by the transmitting UE, up to UE implementation >maxRetxThreshold Undefined Selected by the transmitting UE, up to UE implementation >t-StatusProhibit Undefined Selected by the receiving UE, up to UE implementation >logicalChannelIdentity 2 MAC configuration >priority One >prioritisedBitRate infinity >logicalChannelGroup 0 > schedulingRequestId 0 The scheduling request configuration with this value is applicable for this SCCH if configured by the network. > sl-HARQ-FeedbackEnabled Undefined Selected by the transmitting UE, up to UE implementation

According to one embodiment, in addition to the Direct Communication Request with relay_indication message, that is, the DCR with relay discovery indication message, the Direct Communication Request with Relay UE info (e.g., Relay UE ID) message, and/or the Direct Communication Accept with Relay UE info message are sent to the side. When processed as a link relay discovery message, the PDCP layer and/or RRC layer of the sending terminal (e.g., sidelink relay or remote terminal) transmits the received information to the upper layer (e.g., ProSe layer, V2X layer, or PC5-S layer). Instruction information that can distinguish whether the message is a sidelink relay discovery message or a general sidelink unicast link setup message can be received from the upper layer. The PDCP layer and/or RRC layer of the transmitting terminal (e.g., sidelink relay or remote terminal) may select the corresponding SL-SRB for the sidelink relay discovery message based on the indication information.

According to one embodiment, in addition to the Direct Communication Request with relay_indication message, that is, the DCR with relay discovery indication message, the Direct Communication Request with Relay UE info (e.g., Relay UE ID) message, and/or the Direct Communication Accept with Relay UE info message are sent to the side. When processed as a link relay discovery message, the PDCP layer of the receiving terminal (sidelink relay or remote terminal) delivers the sidelink relay discovery message to the upper layer (e.g., ProSe layer, V2X layer, PC5-S layer). Instruction information that can distinguish whether the message is a sidelink relay discovery message or a general sidelink unicast link setup message can be transmitted to the upper layer.

According to one embodiment, in addition to the Direct Communication Request with relay_indication message, that is, the DCR with relay discovery indication message, the Direct Communication Request with Relay UE info (e.g., Relay UE ID) message, and/or the Direct Communication Accept with Relay UE info message are sent to the side. When processed as a link relay discovery message, the sidelink relay discovery message can be transmitted through resources allocated from a resource pool dedicated to sidelink discovery message transmission if a resource pool dedicated to sidelink discovery message transmission is set. If there is no dedicated resource pool set for sidelink discovery messages, this sidelink relay discovery message can be transmitted through resources allocated from the resource pool set for general sidelink message purposes.

A method of operating a sidelink relay in a wireless communication system according to various embodiments of the present disclosure includes sending a first relay discovery message indicating that it is a sidelink relay capable of relaying data between a remote terminal and another remote terminal. Configuring and transmitting a first relay discovery message through a radio bearer set for the purpose of a relay discovery message between the terminal and the terminal, and a side link between the terminal and the terminal that can relay data from the remote terminal to another remote terminal. The method may include receiving a second relay discovery message searching for a relay through a radio bearer configured for a sidelink relay discovery message and determining that it is a second relay discovery message.

A method of operating a remote terminal (remote UE) in a wireless communication system according to various embodiments of the present disclosure includes: a first relay indicating that the sidelink relay is a sidelink relay capable of relaying data between the remote terminal and another remote terminal; Receiving a discovery message through a radio bearer set for a sidelink relay discovery message and determining that it is a first relay discovery message; and performing a second relay to discover a sidelink relay that can relay data with another remote terminal. Constructing a discovery message and transmitting a second relay discovery message through a radio bearer configured for the sidelink relay discovery message.

In a wireless communication system according to various embodiments of the present disclosure, a sidelink relay includes a communication unit and a control unit. The control unit controls to configure and transmit a first relay discovery message for a sidelink relay that can relay data between the remote terminal and other remote terminals, and can relay data between the remote terminal and other remote terminals. It can be controlled to receive and determine a second relay discovery message for the sidelink relay. In the wireless communication system according to an embodiment of the present disclosure, a remote terminal includes: a communication unit; and a control unit. The control unit controls to receive and determine the first relay search message for the sidelink relay that can relay data between the remote terminal and other remote terminals, and can relay data between the remote terminal and other remote terminals. It can be controlled to configure and transmit a second relay discovery message for the sidelink relay.

Methods according to embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

When implemented as software, a computer-readable storage medium that stores one or more programs (software modules) may be provided. One or more programs stored in a computer-readable storage medium are configured to be executable by one or more processors in an electronic device (configured for execution). One or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure.

These programs (software modules, software) include random access memory, non-volatile memory including flash memory, read only memory (ROM), and electrically erasable programmable ROM. (EEPROM: electrically erasable programmable read only memory), magnetic disc storage device, compact disc-ROM (CD-ROM), digital versatile discs (DVDs), or other forms of disk storage. It can be stored in an optical storage device or magnetic cassette. Alternatively, it may be stored in a memory consisting of a combination of some or all of these. Additionally, a plurality of each configuration memory may be included.

In addition, the program can be accessed through a communication network such as the Internet, an intranet, a local area network (LAN), a wide LAN (WLAN), or a storage area network (SAN), or a combination thereof. It may be stored in an attachable storage device that can be accessed. This storage device can be connected to a device performing an embodiment of the present disclosure through an external port. Additionally, a separate storage device on a communication network may be connected to the device performing an embodiment of the present disclosure.

In the specific embodiments of the present disclosure described above, elements included in the disclosure are expressed in singular or plural numbers depending on the specific embodiment presented. However, singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components, and even components expressed in plural may be composed of singular or singular. Even expressed components may be composed of plural elements.

Meanwhile, in the detailed description of the present disclosure, specific embodiments have been described, but of course, various modifications are possible without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be determined not only by the scope of the patent claims described later, but also by the scope of this patent claim and equivalents.

Claims (2)

In a method of operating a first terminal in a wireless communication system,
A process of generating a sidelink relay discovery message to discover a sideline relay for connection between the first terminal and the second terminal;
A process of identifying a radio bearer to transmit the sidelink relay discovery message;
Method comprising transmitting the sidelink relay discovery message through the radio bearer.
In a first terminal in a wireless communication system,
transceiver; and
Contains at least one processor,
The at least one processor:
Generating a sidelink relay discovery message to discover a sidelink relay for connection between the first terminal and the second terminal,
Identify a radio bearer to transmit the sidelink relay discovery message,
A first terminal configured to transmit the sidelink relay discovery message through the radio bearer.

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