Method and device for transmitting data in wireless communication system

Abstract

A method performed by a relay user equipment in a wireless communication system, of the present disclosure, comprises the steps of: receiving, from a first user equipment, a first message for soliciting a user equipment-to-user equipment relay discovery; on the basis of the first message, transmitting, to a second user equipment, a second message including first identification information for the first user equipment and second identification information for the second user equipment; receiving, from the second user equipment, a third message that responds to a relay discovery including the first identification information and the second identification information; and, on the basis of the first identification information and the second identification information, transmitting, to the first user equipment, a fourth message that responds to a relay discovery.

Description

Method and device for transmitting data in a wireless communication system

[0001] The present disclosure relates to a wireless communication system or a mobile communication system. Specifically, it relates to a method and device for transmitting user data between terminals in a wireless communication system.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz band such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band (Above 6GHz) called millimeter wave (mmWave) such as 28GHz and 39GHz. In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz (THz) band (for example, 3 THz band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and ultra-low latency that is reduced to one-tenth.

[0003] In the early stages of 5G mobile communication technology, the goal is to support services and satisfy performance requirements for ultra-wideband services (eMBB: enhanced Mobile Broadband), ultra-reliable / ultra-low-latency communications (URLLC: Ultra-Reliable Low-Latency Communications), and massive Machine-Type Communications (mMTC). These include beamforming and massive MIMO (Massive MIMO) to alleviate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple sub-carrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and polar codes for reliable transmission of control information, L2 pre-processing, and specific services. Standardization has been progressed for network slicing, which provides specialized, dedicated networks.

[0004] Currently, discussions are underway to improve and enhance the initial 5G mobile communication technology in consideration of the services that 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience based on their own location and status information transmitted by vehicles, NR-U (New Radio Unlicensed) for the purpose of system operation that complies with 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 terrestrial networks is impossible, and Positioning.

[0005] In addition, standardization of wireless interface architecture / protocols is in progress for technologies such as intelligent factories (IIoT: Industrial Internet of Things) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) to provide nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement technology including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step random access (2-step RACH for NR) to simplify random access procedures. Standardization is also in progress for system architecture / services such as 5G baseline architecture (e.g., Service-based Architecture: SBA, Service-based Interface: SBI) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal.

[0006] When such 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, which will require enhanced functions and performance of 5G mobile communication systems and integrated operation of connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, supporting AI services, supporting metaverse services, and drone communications by utilizing eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] In addition, the development of these 5G mobile communication systems includes new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, and AI (Artificial Intelligence) from the design stage and internalize end-to-end AI support functions to realize system optimization, and ultra-high-performance communication and computing resources to realize services with complexity that exceeds the limits of terminal computing capabilities. It could serve as a basis for the development of next-generation distributed computing technologies.

[0008] The present disclosure provides a method and device for transmitting user data between terminals in a wireless communication system or mobile communication system. The technical challenges addressed by the present disclosure are not limited to those mentioned above, and other technical challenges not mentioned will be readily apparent to those skilled in the art, based on the description below.

[0009] Based on the discussion described above, the present disclosure provides a method for processing a control signal in a wireless communication system, which may include: receiving a first control signal transmitted from a base station; processing the received first control signal; and transmitting a second control signal generated based on the processing to the base station.

[0010] The embodiments proposed in the present disclosure provide a device and method capable of effectively providing a service in a wireless communication system.

[0011] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0012] FIG. 1 illustrates the structure of a 5G network according to an embodiment of the present disclosure.

[0013] FIG. 2 illustrates a 5G ProSe (Proximity based Services) UE-to-UE Relay structure according to an embodiment of the present disclosure.

[0014] FIG. 3 illustrates a 5G ProSe UE-to-UE Relay Discovery Model B scheme according to an embodiment of the present disclosure.

[0015] FIG. 4 illustrates a procedure of a 5G ProSe UE-to-UE Relay Discovery Model B scheme according to an embodiment of the present disclosure.

[0016] FIG. 5 is a diagram showing the configuration of a terminal according to an embodiment of the present disclosure.

[0017] FIG. 6 is a diagram illustrating the configuration of a base station or network entity according to an embodiment of the present disclosure.

[0018] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the attached drawings. It should be noted that, where possible, identical components are represented by identical reference numerals throughout the attached drawings. Furthermore, detailed descriptions of well-known functions and configurations that may obscure the gist of the present disclosure will be omitted.

[0019] In describing the embodiments herein, descriptions of technical details that are well known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure will be omitted. This is to avoid obscuring the gist of the present disclosure by omitting unnecessary explanations and to convey the gist more clearly.

[0020] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0021] The advantages and features of the present disclosure, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. The embodiments are provided only to ensure that the disclosure of the present disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

[0022] Furthermore, when describing the present disclosure, detailed descriptions of related functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present disclosure. Furthermore, the terms described below are defined based on the functions of the present disclosure and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the content throughout this specification.

[0023] Hereinafter, the base station is an entity that performs resource allocation of the terminal, and may be at least one of a gNode B, an eNode B, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, the downlink (DL) refers to a wireless transmission path of a signal transmitted from the base station to the terminal, and the uplink (UL) refers to a wireless transmission path of a signal transmitted from the terminal to the base station. In addition, although LTE, LTE-A, or 5G systems may be described as examples below, embodiments of the present disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, the 5th generation mobile communication technology (5G, new radio, NR) developed after LTE-A may be included here, and the 5G below may also be a concept that includes existing LTE, LTE-A, and other similar services. In addition, the present disclosure may be applied to other communication systems through some modifications within a scope that does not significantly deviate from the scope of the present disclosure, as judged by a person having skilled technical knowledge.

[0024] At this time, it will be understood that each block of the processing flowchart drawings and combinations of the flowchart drawings can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flowchart block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flowchart block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0025] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0026] Here, the term '~ unit' used in the present embodiment means a software or hardware component such as an FPGA or ASIC, and the '~ unit' performs certain roles. However, the '~ unit' is not limited to software or hardware. The '~ unit' may be configured to be on an addressable storage medium and may be configured to regenerate one or more processors. Thus, as an example, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, the components and '~ units' may be implemented to regenerate one or more CPUs within a device or a secure multimedia card. Additionally, in the embodiment, '~bu' may include one or more processors.

[0027] Wireless communication systems are evolving from providing voice-oriented services in the early days to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as communication standards such as 3GPP's HSPA (High Speed ​​Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2's HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE's 802.16e.

[0028] As a representative example of the above broadband wireless communication system, the LTE system adopts the Orthogonal Frequency Division Multiplexing (OFDM) method in the downlink (DL) and the Single Carrier Frequency Division Multiple Access (SC-FDMA) method in the uplink (UL). The uplink refers to a wireless link in which a terminal (User Equipment (UE) or Mobile Station (MS)) transmits data or control signals to a base station (eNode B, gNode B, or base station (BS)), and the downlink refers to a wireless link in which a base station transmits data or control signals to a terminal. The above multiple access method can distinguish the data or control information of each user by allocating and operating the time-frequency resources for transmitting data or control information to each user so that they do not overlap, that is, so as to achieve orthogonality.

[0029] As a future communication system beyond LTE, 5G communication systems must be able to freely reflect the diverse needs of users and service providers. Therefore, they must support services that simultaneously satisfy these diverse requirements. Services being considered for 5G communication systems include enhanced Mobile Broadband (eMBB), massive Machine Type Communication (mMTC), and Ultra-Reliable Low Latency Communication (URLLC).

[0030] eMBB aims to provide data transmission rates that are significantly higher than those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB must be able to support a peak data rate of 20 Gbps in the downlink and a peak data rate of 10 Gbps in the uplink from the perspective of a single base station. Furthermore, 5G communication systems must simultaneously provide the peak data rate and an increased user-perceived data rate for terminals. To meet these requirements, improvements in various transmission and reception technologies, including improved multi-input, multi-output (MIMO) transmission technology, are required. Furthermore, while LTE transmits signals using a maximum transmission bandwidth of 20 MHz in the 2 GHz band, 5G communication systems can meet the data transmission rates required by 5G communication systems by using a wider frequency bandwidth than 20 MHz in the 3-6 GHz or higher 6 GHz band.

[0031] At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. To efficiently provide the Internet of Things, mMTC requires support for large-scale terminal connection within a cell, improved terminal coverage, improved battery life, and reduced terminal costs. The Internet of Things provides communication functions by attaching various sensors and various devices, so a large number of terminals (e.g., 1,000,000 terminals / km) are required within a cell. 2 ) must be able to support. Furthermore, terminals supporting mMTC are likely to be located in shadow areas not covered by cells, such as basements of buildings, due to the nature of the service, and thus may require wider coverage than other services provided by 5G communication systems. Terminals supporting mMTC must be composed of low-cost terminals, and because it is difficult to frequently replace the terminal's battery, a very long battery life time, such as 10 to 15 years, may be required.

[0032] Finally, URLLC refers to cellular-based wireless communication services used for specific mission-critical purposes. Examples include remote control of robots or machinery, industrial automation, unmanned aerial vehicles (UAVs), remote health care, and emergency alerts. Therefore, URLLC communications must offer extremely low latency and high reliability. For example, services supporting URLLC must meet air interface latency requirements of less than 0.5 milliseconds and a packet error rate (PER) of less than 10^-5. Therefore, for services supporting URLLC, 5G systems must provide shorter transmission time intervals (TTIs) than other services, and design requirements may require the allocation of extensive resources in the frequency band to ensure communication link reliability.

[0033] The three 5G services—eMBB, URLLC, and mMTC—can be multiplexed and transmitted within a single system. To meet the differing requirements of each service, different transmission and reception techniques and parameters can be used. Of course, 5G is not limited to the three services described above.

[0034] In this disclosure, phrases such as “A and / or B,” “A or B,” “at least one of A and B,” “at least one of A or B,” “A, B, or C,” “at least one of A, B, and C,” and “at least one of A, B, or C” can each include any one of the items listed together in that phrase, or all possible combinations thereof. Terms such as “first,” “second,” or “first” or “second” may be used merely to distinguish the corresponding component from other corresponding components and do not limit the corresponding components in any other respect (e.g., importance or order).

[0035] Hereinafter, the base station is an entity that performs resource allocation of a terminal, and may be at least one of a Node B, a BS (Base Station), an eNB (eNode B), a gNB (gNode B), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In addition, the embodiments of the present disclosure may be applied to other communication systems having a similar technical background or channel form to the embodiments of the present disclosure described below. In addition, the embodiments of the present disclosure may be applied to other communication systems through some modifications without significantly departing from the scope of the present disclosure at the discretion of a person having skilled technical knowledge.

[0036] In the present disclosure, network technology may refer to standard specifications defined by the International Telecommunication Union (ITU) or 3GPP (e.g., TS 23.501, TS 23.502, TS 23.503, etc.), and components included in the network structure of FIG. 1 may each mean a physical entity, or may mean software performing an individual function, or hardware combined with software. Reference symbols shown as Nx, such as N1, N2, N3, ... in the drawings, represent known interfaces between NFs in a 5G core network (CN), and since a related description may refer to the standard specification (TS 23.501), a detailed description will be omitted.

[0037] In the following description, terms used to identify connection nodes, terms referring to network entities (NEs) or network functions (NFs), terms referring to messages, terms referring to interfaces between network entities, terms referring to various identification information, etc. are provided as examples for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to objects having equivalent technical meanings may be used.

[0038] For convenience of explanation, some terms and names defined in the 3rd generation partnership project long-term evolution (3GPP) standards may be used. However, the present disclosure is not limited to these terms and names, and can be equally applied to systems conforming to other standards.

[0039] FIG. 1 is a diagram showing an example of a configuration of a wireless communication system according to an embodiment of the present disclosure, and FIG. 1 exemplifies the configuration of a 5G system.

[0040] Referring to FIG. 1, a 5G network may include network entities (NE) or network functions (NF) described below.

[0041] (R)AN ((Radio) Access Network) is an entity that performs wireless resource allocation of a terminal, and may be at least one of an eNode B, a Node B, a BS (Base Station), an NG-RAN (Next Generation Radio Access Network), a 5G-AN (5G Access Network), a 5G NR (5G New Radio), a radio access unit, a base station controller, or a node on a network.

[0042] The terminal may include a UE (User Equipment), NG UE (Next Generation UE), MS (Mobile Station), cellular phone, smartphone, computer, IoT (Internet of Things) device, or multimedia system capable of performing communication functions.

[0043] Furthermore, while the embodiments of the present disclosure are described below using a 5G system as an example, the embodiments of the present disclosure can also be applied to other communication systems with similar technical backgrounds. Furthermore, the embodiments of the present disclosure can be applied to other communication systems with some modifications, as determined by a person skilled in the art, without significantly departing from the scope of the present disclosure.

[0044] As wireless communication systems evolve from 4G to 5G, a new core network (CN) called the Next Generation Core (NG Core) or 5GC (5G Core Network) is being defined. This new core network virtualizes all existing network entities (NEs) into network functions (NFs). According to one embodiment of the present disclosure, a network function may refer to a network entity, a network component, or a network resource.

[0045] According to one embodiment of the present disclosure, 5GC may include NFs as illustrated in FIG. 1. Of course, the present invention is not limited to the example illustrated in FIG. 1, and 5GC may include more or fewer NFs than the number of NFs illustrated in FIG. 1.

[0046] The Access and Mobility Management Function (AMF) may be a network function that manages the access and mobility of a terminal (UE). For example, AMF may perform network functions such as terminal registration, connection, reachability, mobility management, access verification, authentication, and mobility event generation.

[0047] A Session Management Function (SMF) may be a network function that manages a Packet Data Network (PDN) connection provided to a user equipment (UE). A PDN connection may be referred to as a Protocol Data Unit (PDU) Session. For example, an SMF may perform network functions such as session management through the establishment, modification, and release of sessions and the maintenance of tunnels between the User Plane Function (UPF) and the RAN, selection and control of the User Plane (UPF), control of traffic processing in the UPF, and control of charging data collection.

[0048] PCF (Policy Control Function) may be a network function that applies a mobile carrier's service policy, charging policy, and PDU Session policy to a terminal.

[0049] Unified Data Management (UDM) can be a network function that stores subscriber information. For example, UDM can perform functions such as generating authentication information for 3GPP security, processing user identifiers (User IDs), managing a list of network functions supporting UEs, and managing subscription information.

[0050] The Network Exposure Function (NEF) may provide information about a terminal to a server outside the 5G network. Additionally, NEF may provide the information necessary for 5G network services and store it in the Unified Data Repository (UDR).

[0051] The User Plane Function (UPF) may function as a gateway that transmits user data (PDU) to the Data Network (DN). More specifically, the UPF may perform the role of processing data so that data transmitted by a terminal can be transmitted to an external network or data received from an external network can be transmitted to the terminal. For example, the UPF may perform network functions such as serving as an anchor between radio access technologies (RATs), packet routing and forwarding, packet inspection, user plane policy application, traffic usage report generation, and buffering.

[0052] NRF (Network Repository Function) can store the profiles of NFs and perform the function of discovering NFs.

[0053] AUSF (Authentication Server Function) can perform terminal authentication in 3GPP access networks and non-3GPP access networks.

[0054] NSSF (Network Slice Selection Function) can perform the function of selecting a Network Slice Instance provided to a terminal.

[0055] The Network Data Analytics Function (NWDAF) collects data from multiple NFs (Network Functions) to ensure efficient operation of the 5GC network. This data is analyzed using a machine learning (ML) model, and the results are provided to the NFs, helping them provide efficient network services.

[0056] An Application Function (AF) can communicate with a network operator to enable external servers (Application Servers) to utilize network services provided by the network operator. Depending on the deployment entity, AFs can be categorized as internal AFs and external AFs. Internal AFs deployed by network operators can communicate directly with network functions (NFs) within the network operator. AFs deployed by third-party service providers (3rd-party service providers) must go through an NEF to communicate with NFs within the network operator.

[0057] DN (Data Network) can be a data network where terminals transmit and receive data to use network operator services or third-party services.

[0058] The terminal may include an IoT device. The IoT device may include a device that does not use battery power or operates with very little power, and such IoT devices are referred to as ambient IoT devices (or simply Ambient IoT).

[0059] FIG. 2 illustrates a 5G ProSe (Proximity based Services) UE-to-UE Relay structure according to an embodiment of the present disclosure.

[0060] Referring to FIG. 2, both 5G ProSe End UE and 5G ProSe UE-to-UE Relay are 5G ProSe enabled UEs. The 5G ProSe End UE can communicate with the counterpart 5G ProSe End UE using the 5G ProSe UE-to-UE Relay, and the 5G ProSe UE-to-UE Relay can provide a data relay service to enable 5G ProSe End UEs to communicate. In addition, 5G ProSe enabled UEs use the PC5 interface to transmit data and signaling.

[0061] FIG. 3 illustrates a 5G ProSe UE-to-UE Relay Discovery Model B scheme according to an embodiment of the present disclosure.

[0062] Figure 3 illustrates a Model B scheme in which a 5G ProSe End UE transmits a Discovery Solicitation message to search for a 5G ProSe UE-to-UE Relay. The 5G ProSe UE-to-UE Relay Discovery Solicitation message includes the Type of Discovery Message, its own User Info ID, RSC (Relay Service Code), and the other party's User Info ID.

[0063] The Type of Discovery Message indicates the type of message being transmitted. The User Info ID is a value configured in the 5G ProSe End UE and 5G ProSe UE-to-UE Relay for 5G ProSe UE-to-UE Relay Discovery. The RSC can identify the connectivity service provided by the 5G ProSe UE-to-UE Relay.

[0064] The 5G ProSe UE-to-UE Relay that receives the Discovery Solicitation message transmitted by the 5G ProSe End UE can check the RSC included in the message to confirm whether it is a connectivity service it provides and then relay it again.

[0065] When a 5G ProSe End UE relayed by a 5G ProSe UE-to-UE Relay receives a Discovery Solicitation message, the other party's 5G ProSe End UE can check the RSC and the other party's User Info ID included in the received message and, if the message sent to itself is correct, generate and send a 5G ProSe UE-to-UE Relay Discovery Response message.

[0066] FIG. 4 illustrates a procedure of a 5G ProSe UE-to-UE Relay Discovery Model B scheme according to one embodiment of the present disclosure.

[0067] In step 410, the (discoverer) 5G ProSe End UE-1 may perform the 5G ProSe UE-to-UE Relay Discovery Model B procedure to communicate with the (discoveree) 5G ProSe End UE-2. To this end, the UE-1 may transmit a 5G ProSe UE-to-UE Relay Discovery Solicitation message. The 5G ProSe UE-to-UE Relay Discovery Solicitation message may include a Type of Discovery Message, a User Info ID of UE-1, a User Info ID of UE-2, and an RSC value. To transmit the message, the Source Layer-2 ID value may be assigned a value arbitrarily set by the UE, and the Destination Layer-2 ID value may be set to a Default ID value. The Layer-2 ID value may be an address value that 5G ProSe enabled UEs use to confirm whether a received message is a message sent to the UE. In particular, since the Default ID value means Broadcast, if this value is assigned as the destination (Destination Layer-2 ID) address, all terminals can receive this message. The message transmitted by UE-1 can be received by 5G ProSe UE-to-UE Relay-1, 5G ProSe UE-to-UE Relay-2, and 5G ProSe UE-to-UE Relay-3.

[0068] In step 420, 5G ProSe UE-to-UE Relay-1, 5G ProSe UE-to-UE Relay-2, and 5G ProSe UE-to-UE Relay-3, which received the 5G ProSe UE-to-UE Relay Discovery Solicitation message transmitted by UE-1, check the message. At this time, each Relay checks the RSC value in the message. It checks whether the RSC is one of its services, and if it is the same as the RSC value it serves, it re-creates and retransmits the 5G ProSe UE-to-UE Relay Discovery Solicitation message, and if it is not the same as the RSC value, it ignores the message. In FIG. 4, Relay-1 and Relay-2 support the RSC service and thus retransmit the 5G ProSe UE-to-UE Relay Discovery Solicitation message, but Relay-3 does not support it and thus may ignore and not retransmit the message. The 5G ProSe UE-to-UE Relay Discovery Solicitation message retransmitted by the Relay may contain the following values:

[0069] - Type of Discovery Message, User Info ID of discoverer 5G ProSe End UE (UE-1), User Info ID of discoveree 5G ProSe End UE (UE-2), User Info ID of 5G ProSe UE-to-UE Relay, and RSC.

[0070] To transmit a 5G ProSe UE-to-UE Relay Discovery Solicitation message, the Source Layer-2 ID value can be assigned a value of its own choice and the Destination Layer-2 ID value can be set to the Default ID value. In addition, the Relay can store the Source Layer-2 ID value and RSC value of UE-1 to provide retransmission services.

[0071] At step 430, the (discoveree) 5G ProSe End UE (UE-2) may receive the 5G ProSe UE-to-UE Relay Discovery Solicitation message retransmitted by Relay-1 and Relay-2. UE-2 receives the message and checks the RSC value and the User Info ID of the discoveree 5G ProSe End UE (UE-2). It may check whether the RSC value is the same as the RSC value of the service to which it has subscribed and check the User Info ID value to confirm whether the message has been sent to it. UE-2 may select one of the messages received from multiple Relays and transmit a 5G ProSe UE-to-UE Relay Discovery Response message to the Relay that sent the message. The method of selecting one of the multiple 5G ProSe UE-to-UE Relay Discovery Solicitation messages received by UE-2 may be selected by considering the strength of the received message signal, the time of message reception, etc. The 5G ProSe UE-to-UE Relay Discovery Response message transmitted by UE-2 may include the following values:

[0072] - Type of Discovery Message, User Info ID of discoverer 5G ProSe End UE, User Info ID of discoveree 5G ProSe End UE, and RSC.

[0073] In order to transmit this 5G ProSe UE-to-UE Relay Discovery Response message, the Source Layer-2 ID value can be assigned a value arbitrarily set by the user, and the Destination Layer-2 ID value can be assigned the Source Layer-2 ID value of the 5G ProSe UE-to-UE Relay Discovery Solicitation message received by the user. In other words, this 5G ProSe UE-to-UE Relay Discovery Solicitation message is not broadcast but unicast transmission directed to a specific Relay. In this embodiment, the address of Relay-2 can be assigned. The message is received by Relay-1 and Relay-2, but since the destination address is Relay-2, only Relay-2 can receive it and Relay-1 can ignore it.

[0074] In step 440, the relay that receives the 5G ProSe UE-to-UE Relay Discovery Response message transmitted by UE-2 may generate a 5G ProSe UE-to-UE Relay Discovery Response message and transmit it to the discoverer 5G ProSe End UE (UE-1). This message may include the following information: Type of Discovery Message, User Info ID of discoveree 5G ProSe End UE, User Info ID of 5G ProSe UE-to-UE Relay, and RSC. In order to transmit this message, the Source Layer-2 ID value is assigned a value arbitrarily set by the relay. In order to set the Destination Layer-2 ID value, the User Info ID of discoverer 5G ProSe End UE and RSC included in the 5G ProSe UE-to-UE Relay Discovery Response message may be checked and used to set the Source Layer-2 ID value of UE-1 stored in step 2. Therefore, the message can be unicast to the (discoverer) 5G ProSe End UE (UE-1).

[0075] The 5G ProSe UE-to-UE Relay Discovery Model B procedure of FIG. 4 may have some operational issues. The User Info ID of the discoverer 5G ProSe End UE (UE-1) and the User Info ID of the discoveree 5G ProSe End UE (UE-2) are stored in a container called a protected direct discovery set for security reasons. In other words, these values ​​may be visible only to UE-1 and UE-2, and may not be verifiable by the Relay. In the procedure of FIG. 4, the Relay verifies the User Info ID of the discoverer 5G ProSe End UE (UE-1) included in the 5G ProSe UE-to-UE Relay Discovery Response message received from UE-2 in order to transmit the 5G ProSe UE-to-UE Relay Discovery Response message to the discoverer 5G ProSe End UE (UE-1), but this is impossible. Therefore, the present disclosure proposes a solution to this problem.

[0076] The first option is to change the following in the messages of steps 420 and 430 of FIG. 4.

[0077] According to one embodiment of the present disclosure, the following values ​​may be added in the 5G ProSe UE-to-UE Relay Discovery Solicitation message of step 420.

[0078] -Source Layer-2 ID of discoveree 5G ProSe End UE

[0079] This value is the value that UE-2 requests to use as the Source Layer-2 ID of the message when transmitting the 5G ProSe UE-to-UE Relay Discovery Response message of step 430 to the Relay. That is, the Relay can determine that the message corresponds to the message received from UE-1 by looking at the Source Layer-2 ID value of the 5G ProSe UE-to-UE Relay Discovery Response message received from UE-2 and transmit it to UE-1.

[0080] - In step 430, UE-2 can assign the value of the Source Layer-2 ID of discoveree 5G ProSe End UE by U2U Relay transmitted by the Relay to the Source Layer-2 ID.

[0081] The second option is to change the following in the messages of steps 420 and 430 of Figure 4:

[0082] The following values ​​can be added to the 5G ProSe UE-to-UE Relay Discovery Solicitation message in step 420.

[0083] -Index associated with Source Layer-2 ID of discoverer 5G ProSe End UE and RSC

[0084] This value is the Index value of the Source Layer-2 ID of the discoverer 5G ProSe End UE and the RSC value stored by the Relay in step 420. This value can be included in the 5G ProSe UE-to-UE Relay Discovery Solicitation message transmitted to UE-2.

[0085] In step 430, UE-2 includes the Index value received in step 420 in the 5G ProSe UE-to-UE Relay Discovery Response message transmitted to the Relay. The Relay receiving this can determine that the message corresponds to the message received from UE-1 through this Index value and transmit it to UE-1.

[0086] The third option is to change the following in the messages of steps 420 and 430 of Figure 4:

[0087] The following values ​​can be added to the 5G ProSe UE-to-UE Relay Discovery Solicitation message in step 420.

[0088] -Source Layer-2 ID of discoverer 5G ProSe End UE

[0089] The above value is the Source Layer-2 ID of the discoverer 5G ProSe End UE value stored by the Relay in step 420. This value can be included in the 5G ProSe UE-to-UE Relay Discovery Solicitation message transmitted to UE-2.

[0090] In step 430, UE-2 includes the Source Layer-2 ID of discoverer 5G ProSe End UE value received in step 420 in the 5G ProSe UE-to-UE Relay Discovery Response message transmitted to the Relay. The Relay receiving this can determine that the message corresponds to the message received from UE-1 through this Source Layer-2 ID of discoverer 5G ProSe End UE value and transmit it to UE-1.

[0091] A fourth option would be to change the messages in steps 420 and 430 of Figure 4.

[0092] The following can be changed in the 5G ProSe UE-to-UE Relay Discovery Solicitation message of step 420.

[0093] In step 420, when the relay transmits the 5G ProSe UE-to-UE Relay Discovery Solicitation message, the Source Layer-2 ID is assigned to a value not used in the existing 5G ProSe UE-to-UE Relay Discovery with Model B procedure, and this is associated with the stored Source Layer-2 ID of the discoverer 5G ProSe End UE value and the RSC value and stored.

[0094] In step 430, UE-2 can assign the value of the Source Layer-2 ID of the 5G ProSe UE-to-UE Relay Discovery Solicitation message received in step 420 as the value of the Destination Layer-2 ID of the 5G ProSe UE-to-UE Relay Discovery Response message transmitted to the Relay. The Relay receiving this can determine that the message corresponds to the message received from UE-1 through the value of the Destination Layer-2 ID of the 5G ProSe UE-to-UE Relay Discovery Response message and transmit it to UE-1.

[0095] FIG. 5 is a diagram showing the configuration of a terminal according to an embodiment of the present disclosure.

[0096] A terminal according to one embodiment of the present disclosure may include a processor (520) that controls the overall operation of the terminal, a transceiver (500) including a transmitter and a receiver, and a memory (510). Of course, the present invention is not limited to the above example, and the terminal may include more or fewer components than those illustrated in FIG. 5.

[0097] According to one embodiment of the present disclosure, the transceiver (500) can transmit and receive signals with network entities or other terminals. The signals transmitted and received with the network entities may include control information and data. In addition, the transceiver (500) can receive signals via a wireless channel, output them to the processor (520), and transmit the signals output from the processor (520) via the wireless channel.

[0098] According to one embodiment of the present disclosure, the processor (520) can control the terminal to perform any one of the operations of the above-described embodiments. Meanwhile, the processor (520), the memory (510), and the transceiver (500) do not necessarily have to be implemented as separate modules, and of course, they can be implemented as a single component in the form of a single chip. In addition, the processor (520) and the transceiver (500) can be electrically connected. In addition, the processor (520) can be an Application Processor (AP), a Communication Processor (CP), a circuit, an application-specific circuit, or at least one processor.

[0099] According to one embodiment of the present disclosure, the memory (510) can store data such as basic programs, application programs, and setting information for the operation of the terminal. In particular, the memory (510) provides the stored data upon request of the processor (520). The memory (510) may be configured as a storage medium or a combination of storage media such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, there may be a plurality of memories (510). In addition, the processor (520) can perform the above-described embodiments based on a program for performing the above-described embodiments of the present disclosure stored in the memory (510).

[0100] FIG. 6 is a diagram illustrating the configuration of a base station or network entity according to an embodiment of the present disclosure.

[0101] A network entity according to one embodiment of the present disclosure may include a processor (620) that controls the overall operation of the network entity, a transceiver (600) including a transmitter and a receiver, and a memory (610). Of course, the present invention is not limited to the above example, and the network entity may include more or fewer components than those illustrated in FIG. 6.

[0102] According to one embodiment of the present disclosure, the transceiver (600) can transmit and receive signals with at least one of other network entities or terminals. The signals transmitted and received with at least one of the other network entities or terminals may include control information and data.

[0103] According to one embodiment of the present disclosure, the processor (620) can control a network entity to perform any one of the operations described above. Meanwhile, the processor (620), the memory (610), and the transceiver (600) do not necessarily have to be implemented as separate modules, and of course, they can be implemented as a single component in the form of a single chip. In addition, the processor (620) and the transceiver (600) can be electrically connected. In addition, the processor (620) can be an Application Processor (AP), a Communication Processor (CP), a circuit, an application-specific circuit, or at least one processor.

[0104] According to one embodiment of the present disclosure, the memory (610) can store data such as basic programs, application programs, and setting information for the operation of a network entity. In particular, the memory (610) provides the stored data upon request of the processor (620). The memory (610) can be configured as a storage medium or a combination of storage media such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, there can be a plurality of memories (610). In addition, the processor (620) can perform the above-described embodiments based on a program for performing the above-described embodiments of the present disclosure stored in the memory (610).

[0105] It should be noted that the aforementioned configuration diagrams, examples of control / data signal transmission methods, examples of operational procedures, and configuration diagrams are not intended to limit the scope of the present disclosure. That is, not all components, entities, or operational steps described in the embodiments of the present disclosure should be construed as essential components for implementing the disclosure, and implementations may be made within a scope that does not detract from the essence of the disclosure even if only some components are included. Furthermore, each embodiment may be combined and operated as needed. For example, parts of the methods proposed in the present disclosure may be combined to operate network entities and terminals.

[0106] The operations of the base station or terminal described above can be realized by providing a memory device storing the corresponding program code in any component within the base station or terminal device. That is, the control unit of the base station or terminal device can execute the operations described above by reading and executing the program code stored in the memory device using a processor or CPU (Central Processing Unit).

[0107] The various components and modules of the entity, base station or terminal device described in this specification may be operated using hardware circuits, such as logic circuits based on complementary metal oxide semiconductors, firmware, software and / or hardware and firmware and / or software embedded in a machine-readable medium. For example, various electrical structures and methods may be implemented using electrical circuits such as transistors, logic gates and application-specific semiconductors.

[0108] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to the embodiments described in the claims or specification of the present disclosure.

[0109] These programs (software modules, software) may be stored in a non-volatile memory including random access memory, flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage devices, compact disc ROMs (CD-ROMs), digital versatile discs (DVDs) or other forms of optical storage devices, magnetic cassettes, or may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may include multiple copies.

[0110] Additionally, the program may be stored in an attachable storage device that is accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device performing an embodiment of the present disclosure.

[0111] In the specific embodiments of the present disclosure described above, components included in the disclosure are expressed in the singular or plural form, depending on the specific embodiment presented. However, the 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. Components expressed in the plural form may be composed of singular elements, or components expressed in the singular form may be composed of plural elements.

[0112] Meanwhile, although specific embodiments have been described in the detailed description of the present disclosure, it is obvious that 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 following claims but also by equivalents of the scope of the claims. In other words, it will be apparent to those skilled in the art to which the present disclosure pertains that other modifications based on the technical idea of ​​the present disclosure are possible. In addition, each of the above embodiments can be combined and operated with each other as needed. For example, parts of the methods proposed in the present disclosure can be combined with each other to operate a base station and a terminal. In addition, although the above embodiments have been presented based on a 5G, NR system, other modifications based on the technical idea of ​​the above embodiments can be implemented with other systems such as LTE, LTE-A, and LTE-A-Pro systems.

[0113] While the detailed description of this disclosure has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents thereof.

Claims

1. A method performed by a relay terminal (user equipment) in a wireless communication system, A step of receiving a first message requesting terminal-to-terminal relay search from a first terminal; A step of transmitting, to a second terminal, a second message including first identification information for the first terminal and second identification information for the second terminal based on the first message; A step of receiving a third message responding to a relay search including the first identification information and the second identification information from the second terminal; and A method comprising the step of transmitting, to the first terminal, a fourth message responding to the relay search based on the first identification information and the second identification information.

2. In claim 1, The third message is identified as a response message to the first message based on the first identification information and the second identification information, A method wherein the fourth message is generated based on the identification.

3. In claim 1, The above first message includes a relay service code (RSC), A method wherein the RSC is used to identify whether the relay terminal can provide relay services to the first terminal and the second terminal.

4. In claim 1, A method, wherein the second message and the fourth message include user ID (identity) information of the relay terminal.

5. In a relay terminal (user equipment) in a wireless communication system, transceiver; and A controller coupled with the above transmitter and receiver is included, The above controller, Receive a first message requesting inter-terminal relay search from the first terminal, Transmitting to the second terminal, a second message including first identification information for the first terminal and second identification information for the second terminal based on the first message, Receive a third message from the second terminal in response to a relay search including the first identification information and the second identification information, A relay terminal configured to transmit, to the first terminal, a fourth message responding to relay search based on the first identification information and the second identification information.

6. In claim 5, The third message is identified as a response message to the first message based on the first identification information and the second identification information, The fourth message is a relay terminal generated based on the identification.

7. In claim 5, The above first message includes a relay service code (RSC), The above RSC is a relay terminal used to identify whether the relay terminal can provide relay service to the first terminal and the second terminal.

8. In claim 5, A relay terminal, wherein the second message and the fourth message include user ID (identity) information of the relay terminal.

9. A method performed by a first terminal (user equipment) in a wireless communication system, A step of transmitting a first message requesting terminal-to-terminal relay search to a relay terminal; and A step of receiving, from the relay terminal, a second message responding to a relay search based on first identification information for the first terminal and second identification information for the second terminal, A method wherein the first identification information and the second identification information are received based on a third message responding to a relay search.

10. In claim 9, A method wherein the third message is associated with a response message of the first message based on the first identification information and the second identification information.

11. In claim 9, The above first message includes a relay service code (RSC), A method wherein the RSC is used to identify whether the relay terminal can provide relay services to the first terminal and the second terminal.

12. In claim 9, A method wherein the second message includes user ID (identity) information of the relay terminal.

13. In a wireless communication system, in the first terminal (user equipment), transceiver; and A controller coupled with the above transmitter and receiver is included, The above controller, Transmit a first message to the relay terminal requesting terminal-to-terminal relay search, is configured to receive a second message responding to a relay search based on identification information for the first terminal and the second terminal from the relay terminal; A method wherein the first identification information and the second identification information are received based on a third message responding to a relay search.

14. In claim 13, The third message is associated with a response message of the first message based on the first identification information and the second identification information, the first terminal.

15. In claim 13, The above first message includes a relay service code (RSC), The above RSC is a first terminal used to identify whether the relay terminal can provide relay service to the first terminal and the second terminal.

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