A method and apparatus for discovering a data path in a wireless communication system

Abstract

The disclosure provides a method performed by a first relay terminal in a wireless communication system including a first terminal supporting a proximity-based service (ProSe), a second terminal, the first relay terminal, and a second relay terminal. The method includes receiving a first message for discovering the second terminal from the first terminal, and transmitting a second message to the second relay terminal based on the first message, wherein the first message includes first information for a relay service and second information for a multi-hop relay.

Description

Technical Field

[0001] This disclosure relates to wireless communication systems. Specifically, this disclosure relates to a method and apparatus for supporting the discovery of reliable data paths in a multi-hop relay environment within a wireless communication system. Background Technology

[0002] 5G mobile communication technology defines a wide frequency band, thus enabling high transmission rates and new services. It can be implemented not only in the "sub-6GHz" band, such as 3.5GHz, but also in the "above 6GHz" band, including 28GHz and 39GHz, known as millimeter waves. Furthermore, the implementation of 6G mobile communication technology (referred to as "super 5G systems") in terahertz (THz) bands (e.g., the 95GHz to 3THz band) is being considered to achieve transmission rates 50 times faster than 5G and ultra-low latency one-tenth that of 5G.

[0003] In the early stages of 5G mobile communication technology development, standardization work is underway to support and meet performance requirements for services associated with enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine-type communication (mMTC). This includes: beamforming and massive MIMO for reducing radio-wave path loss and increasing radio-wave transmission distance in millimeter waves; parameter sets supporting efficient use of millimeter wave resources and dynamic operation of time slot formats (e.g., operating multi-subcarrier spacing); initial access technologies to support multi-beam transmission and broadband; defining and operating the BWP (broadband portion); new channel coding methods such as LDPC (low-density parity-check) codes for large data transmissions and polar codes for highly reliable transmission of control information; L2 preprocessing; and network slicing for providing dedicated networks specifically for particular services.

[0004] Currently, considering the services that 5G mobile communication technology needs to support, discussions are underway regarding improvements and performance enhancements to the initial 5G mobile communication technology, and physical layer standards for related technologies have been defined, such as: V2X (vehicle-to-everything) for autonomous vehicles to assist driving decisions based on vehicle location and status information transmitted by the vehicle and for improving user convenience; NR-U (New Radio Unlicensed) designed to ensure that the system operates in unlicensed frequency bands in compliance with various regulatory requirements; NR UE power saving; non-terrestrial networks (NTN) for UE-satellite direct communication to provide coverage in areas where terrestrial network communication is unavailable; and positioning.

[0005] Furthermore, standardization of air interface architecture / protocols is underway, with related technologies including: Industrial Internet of Things (IIoT) to support new services through interconnection and integration with other industries; IAB (Integrated Access and Backhaul) to provide nodes for network service area expansion by supporting wireless backhaul links and access connections in an integrated manner; mobility enhancements including conditional handover and DAPS (Dual Active Protocol Stack) handover; and two-step random access (2-step RACH for NR) to simplify random access procedures. Standardization of system architecture / services is also progressing, concerning: 5G baseline architectures (e.g., service-based architectures or service-based interfaces) for joint Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) for receiving services based on UE location.

[0006] With 5G mobile communication systems already commercially available, the number of devices connecting to communication networks is increasing exponentially. Therefore, it is foreseeable that enhanced functionality and performance of 5G mobile communication systems, as well as centralized operation of connected devices, will be necessary. To this end, new research is planned on: Extended Reality (XR) for effectively supporting technologies such as AR (Augmented Reality), VR (Virtual Reality), and MR (Mixed Reality); enhancing 5G performance and reducing complexity through the utilization of Artificial Intelligence (AI) and Machine Learning (ML); AI service support; metaverse service support; and drone communication.

[0007] Furthermore, the aforementioned evolution of 5G mobile communication systems will serve as the foundation for developing the following technologies: not only new waveforms for providing coverage in the terahertz band of 6G mobile communication technology, such as multi-antenna transmission technologies for full-dimensional MIMO (FD-MIMO) / array antennas and massive MIMO antennas, metamaterial-based lenses and antennas for improving terahertz band signal coverage, high-dimensional spatial multiplexing technologies utilizing OAM (orbital angular momentum), and RIS (reconfigurable smart surfaces), but also full-duplex technologies for improving the frequency efficiency of 6G mobile communication technology and improving system networks, AI-based communication technologies for system optimization by utilizing satellites and AI (artificial intelligence) from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technologies for providing services with complexity levels exceeding the UE's operational capabilities by utilizing ultra-high-performance communication and computing resources. Summary of the Invention

[0008] [Technical Issues]

[0009] This disclosure aims to provide an apparatus and method for effectively providing services in a wireless communication system.

[0010] This disclosure aims to provide a method and apparatus for effectively supporting proximity-based services (ProSe) in a multi-hop environment.

[0011] The technical topics addressed in this disclosure are not limited to those mentioned above, and other technical topics not mentioned herein will be clearly understood by those skilled in the art from the following description.

[0012] [Technical Solution]

[0013] According to one embodiment of this disclosure, a method for processing control signals in a wireless communication system may include: receiving a first control signal sent by a base station, processing the received first control signal, and sending a second control signal generated based on the above processing to the base station.

[0014] [Beneficial Effects]

[0015] According to the embodiments proposed in this disclosure, an apparatus and method are provided that can effectively provide services in a wireless communication system.

[0016] The beneficial effects brought about by this disclosure are not limited to those described above. Those skilled in the art can clearly understand other effects not mentioned herein from the following description. Attached Figure Description

[0017] Figure 1 The architecture of a 5G network according to one embodiment of the present disclosure is shown.

[0018] Figure 2 A structure supporting multi-hop 5G proximity service (ProSe) UE to network relay is shown according to one embodiment of the present disclosure.

[0019] Figure 3 A structure for a multi-hop 5G Proximity Service (ProSe) UE-to-network relay according to another embodiment of this disclosure is shown.

[0020] Figure 4 An example of a communication disconnection that may occur in multi-hop ProSe communication according to one embodiment of this disclosure is shown.

[0021] Figure 5 The present disclosure illustrates a process for a UE supporting 5G ProSe to perform data path discovery for data transmission according to one embodiment of the present disclosure.

[0022] Figure 6 This illustrates a scenario in which the same data is redundantly transmitted through multiple data transmission paths according to one embodiment of the present disclosure.

[0023] Figure 7The present disclosure illustrates data transmission according to a flooding scheme in one embodiment of the present disclosure, wherein data is transmitted directly without performing data path discovery.

[0024] Figure 8 The structure of a UE according to one embodiment of the present disclosure is shown.

[0025] Figure 9 The structure of a base station or network entity according to one embodiment of the present disclosure is shown. Detailed Implementation

[0026] In the following, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that, in the drawings, identical or similar elements are indicated by identical or similar reference numerals wherever possible. Furthermore, detailed descriptions of known functions or configurations that might obscure the subject matter of this disclosure will be omitted.

[0027] In describing embodiments of this disclosure, descriptions of technical content known in the art and not directly related to this disclosure will be omitted. The omission of unnecessary descriptions is intended to avoid obscuring the main ideas of this disclosure and to more clearly convey these main ideas.

[0028] For the same reason, some elements may be shown, omitted, or schematically in the accompanying drawings. Also, the dimensions of each element do not perfectly reflect its actual size. In all the drawings, the same or corresponding elements are labeled with the same reference numerals.

[0029] The advantages and features of this disclosure, and the ways in which they are implemented, will become apparent from the following detailed description of the embodiments in conjunction with the accompanying drawings. However, this disclosure is not limited to the embodiments given below, but can be implemented in various different forms. The following embodiments are provided only to fully disclose this disclosure and to inform those skilled in the art of its scope, and this disclosure is limited only by the scope of the appended claims. Throughout the specification, the same or similar reference numerals indicate the same or similar elements.

[0030] In this document, it should be understood that each block in the flowchart illustration, and combinations of blocks in the flowchart illustration, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to generate a machine, such that the instructions, executed by the computer or other programmable data processing device, create means for implementing the functions specified in one or more blocks in the flowchart. These computer program instructions can also be stored in a computer-usable or computer-readable storage medium that can instruct the computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer-usable or computer-readable storage medium can generate an article of manufacture including instruction means that implement the flowchart. Figure 1 The functions specified in one or more boxes. Computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be executed on the computer or other programmable apparatus, thereby generating a computer-implemented process. Thus, the instructions that execute on the computer or other programmable apparatus provide for implementing the process. Figure 1 The steps of the functions specified in one or more boxes.

[0031] Furthermore, each box in the flowchart may represent a module, segment, or portion of code, containing one or more executable instructions for implementing a specific logical function. It should also be noted that in some alternative implementations, the functions described in the boxes may not occur in sequence. For example, depending on the functions involved, two boxes shown sequentially may actually be executed substantially simultaneously, or these boxes may sometimes be executed in reverse order.

[0032] As used in embodiments of this disclosure, the term "unit" refers to a software element or hardware element, such as a field-programmable gate array (FPCA) or an application-specific integrated circuit (ASIC), and the term "unit" can perform a specific function. However, "unit" is not always limited to the meaning of software or hardware. A "unit" may be configured to be stored in an addressable storage medium or configured to execute one or more processors. Thus, a "unit" includes, for example: software elements, object-oriented software elements, class elements or task elements, processes, functions, attributes, programs, subroutines, program code fragments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and parameters. The elements and functions provided by a "unit" can be combined into a smaller number of elements, or "units," or divided into a larger number of elements, or "units." Furthermore, the elements and "units" may be implemented as one or more CPUs being generated within a device or secure multimedia card.

[0033] In the following description, a base station is an entity that allocates resources to terminals and can be at least one of a Node B, a base station (BS), an eNode B (eNB), a gNode B (gNB), a radio access unit, a base station controller, and a node in a network. A terminal can 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. Furthermore, the embodiments of this disclosure described below can also be applied to other communication systems with similar technical backgrounds or channel types. Moreover, based on the judgment of those skilled in the art, the embodiments of this disclosure can also be applied to other communication systems with some modifications without significantly departing from the scope of this disclosure.

[0034] In the following description, for ease of description, the following terms are used exemplarily: terms for identifying access nodes, terms for referring to network entities or network functions (NFs), terms for referring to messages, terms for referring to interfaces between network entities, terms for referring to various identification information, etc. Therefore, this disclosure is not limited to the following terms, and other terms referring to objects with equivalent technical meanings may also be used.

[0035] In the following description, for ease of description, some terms and names defined in the 3GPP standards may be used. However, this disclosure is not limited to these terms and names and can be applied in the same manner to systems conforming to other standards.

[0036] According to embodiments of the present disclosure, a method and apparatus are provided for using a user plane (UPF) to transmit control signals to utilize services provided by the user plane.

[0037] Figure 1 The architecture of a 5G network according to one embodiment of the present disclosure is shown.

[0038] refer to Figure 1 The network entities or network nodes that make up a 5G network are as follows.

[0039] A (Radio) Access Network ((R)AN) is an entity that performs radio resource allocation to a UE and may be at least one of an eNode B, Node B, base station (BS), next-generation radio access network (NG-RAN), 5G-AN, radio access unit, base station controller, or a node in the network.

[0040] Terminals may include user equipment (UE), next-generation UE (NG UE), mobile station (MS), cellular phone, smartphone, computer, or multimedia system capable of performing communication functions. Similarly, in the following description, embodiments of this disclosure will be described using a 5G system as an example; however, embodiments of this disclosure can also be applied to other communication systems with similar technical backgrounds. Furthermore, based on the judgment of those skilled in the art, embodiments of this disclosure can be applied to other communication systems with some modifications without significantly departing from the scope of this disclosure.

[0041] As wireless communication systems evolve from 4G to 5G, a new core network (CN), known as the next-generation core network (NG Core) or 5G core network (5GC), has been defined. This new core network fully virtualizes existing network entities (NEs) into network functions (NFs). According to one embodiment of this disclosure, a network function (NF) may refer to a network entity, a network component, and a network resource.

[0042] According to one embodiment of this disclosure, the 5GC may include... Figure 1 The NF shown is clearly not limited to this disclosure. Figure 1 For example, and 5GC can contain more than Figure 1 The number of NFs shown is greater or less than the number of NFs.

[0043] Access and Mobility Management Functions (AMFs) can be network functions that manage the access and mobility of a UE. For example, an AMF can perform network functions such as registration, connectivity, reachability, mobility management, access authentication, authorization, and mobility event generation.

[0044] A Session Management Function (SMF) can be a network function that manages the Packet Data Network (PDN) connection provided to a User Equipment (UE). This PDN connection may be referred to as a Protocol Data Unit (PDU) session. For example, the SMF may perform network functions such as session management functions including session establishment, modification, and release, as well as the tunnel maintenance between the User Plane Function (UPF) and the RAN required for this, user plane (UP) selection and control, traffic processing control at the UPF, and charging data collection control.

[0045] Policy control function (PCF) can be a network function that applies the mobile communication service provider's service policy, charging policy, and PDU session policy to the UE.

[0046] Unified Data Management (UDM) can be a network function that stores user information. For example, UDM can perform functions such as generating authentication information for 3GPP security, processing user IDs, managing the list of network functions supported by the UE, and managing subscription information.

[0047] Network Open Function (NEF) can be a function that provides UE-related information to a server located outside the 5G network. In addition, NEF can provide the information required to provide services to the 5G network and store that information in the UDR.

[0048] User plane functions (UPFs) can function as gateways delivering user data (PDUs) to a data network (DN). More specifically, UPFs can be used to process data to deliver data sent by the UE to an external network or to deliver incoming data from an external network to the UE. As examples, UPFs can perform network functions such as acting as an anchor point between radio access technologies (RATs), packet routing and forwarding, packet detection, user plane policy enforcement, traffic usage report creation, and caching.

[0049] The Network Repository Function (NRF) can perform NF discovery.

[0050] The Authentication Server Function (AUSF) can perform UE authentication in both 3GPP and non-3GPP access networks.

[0051] The Network Slice Selection (NSSF) function can perform the selection of network slice instances provided to the UE.

[0052] A data network (DN) can be a data network through which a UE sends or receives data to use the services of a network service provider or a third-party service provider.

[0053] Furthermore, the terms used in this disclosure may be defined as follows.

[0054] The term "ProSe service, or proximity-based service (ProSe)" refers to a service that enables discovery, direct communication between physically adjacent devices, communication via base stations, or communication via third-party devices. In this context, user plane data can be exchanged via a direct data path without traversing the core network.

[0055] A UE that supports ProSe can refer to a UE that supports ProSe discovery and / or ProSe communication.

[0056] ProSe UE to Network Relay can refer to a relay that is a ProSe-enabled UE and acts as a communication relay between the ProSe-enabled UE and the network.

[0057] ProSe UE-to-UE relay (neighborhood service UE-to-UE relay) can refer to a relay that is a ProSe-enabled UE and acts as a neighborhood service communication relay between ProSe-enabled UEs.

[0058] ProSe discovery can refer to a process in which a ProSe-enabled UE identifies whether there is another ProSe-enabled UE or a ProSe relay providing proximity services.

[0059] Figure 2 The present disclosure illustrates a structure for a multi-hop 5G Proximity Service (ProSe) UE-to-network relay according to one embodiment of the present disclosure.

[0060] Reference Figure 2 The 5G ProSe remote UE, 5G ProSe UE-to-UE relay, and 5G ProSe UE-to-network relay can be 5G ProSe-enabled UEs. Furthermore, in a multi-hop environment, the 5G ProSe remote UE can communicate with the NG-RAN (or network) using the 5G ProSe UE-to-UE relay and the 5G ProSe UE-to-network relay. The 5G ProSe UE-to-UE relay and the 5G ProSe UE-to-network relay can provide data relay services to allow the 5G ProSe remote UE to communicate with the network in a multi-hop environment. Additionally, 5G ProSe-enabled UEs (e.g., at least one of 5G ProSe remote UE, 5G ProSe UE-to-UE relay, or 5G ProSe UE-to-network relay) can use the PC5 interface to transmit data and signaling. 5G ProSe-enabled UEs and the NG-RAN (or network) can use the Uu interface for user data transmission. In the following, the terms "UE" or "relay" in embodiments of this disclosure may refer to a 5G ProSe-enabled UE. Furthermore, a UE supporting 5G ProSe can refer to at least one of 5G ProSe remote UE, 5G ProSe UE-to-UE relay, and 5G ProSe UE-to-network relay. Of course, the above examples are not limiting and may also include another device not included in the above examples that performs 5G ProSe communication.

[0061] Figure 3 The structure of a multi-hop 5G ProSe UE-to-UE relay according to one embodiment of the present disclosure is shown.

[0062] Reference Figure 3The 5G ProSe end UE and the 5G ProSe UE-to-UE relay are UEs that support 5G ProSe, and the 5G ProSe end UE can communicate with the peer 5G ProSe end UE by using the 5G ProSe UE-to-UE relay. The 5G ProSe UE-to-UE relay can provide data relay services, thus enabling multiple 5G ProSe end UEs to perform communication. In addition, 5G ProSe-enabled UEs (e.g., 5G ProSe end UE and 5G ProSe UE-to-UE relay) can use the PC5 interface to transmit data and signaling.

[0063] Figure 3 illustrates a structure in which at least one 5G ProSe UE-to-UE relay support can be used for multi-hop data transmission.

[0064] This disclosure proposes a scheme for supporting reliable communication of UEs supporting 5G ProSe, wherein the UEs supporting 5G ProSe perform communication in ProSe communication in a multi-hop environment by using 5G ProSe UE-to-UE relay or 5G ProSe UE-to-network relay.

[0065] Figure 4 An example of a communication disconnection that may occur in multi-hop ProSe communication according to one embodiment of this disclosure is shown.

[0066] Reference Figure 4 When communication infrastructure is damaged by disasters such as earthquakes and fires, communication can become impossible. In this case, a solution that supports communication by utilizing user terminals without relying on the damaged infrastructure (e.g., base stations) could be ProSe. Since UEs operate on battery power, their communication transmission distance may be significantly shorter than that of base stations. Therefore, to communicate with a UE located in a remote location, the UE can perform communication by relaying data via one or more nearby UEs. Communication performed by relaying data via nearby UEs to reach a remote UE can be called multi-hop communication. However, because communication is performed across multiple terminals, reliable communication can be difficult due to problems in the communication links between hops. Figure 4 As shown, the UE may run out of battery, causing it to shut down and resulting in communication loss. Furthermore, the distance between two UEs may be greater than the UE's transmission distance, or communication may be interrupted by obstacles such as vehicles or buildings. Therefore, this disclosure proposes a scheme for reliably performing ProSe communication based on multi-hops.

[0067] This disclosure can be applied to communication methods using 5G ProSe UE-to-UE relay or 5G ProSe UE-to-network relay (e.g., ProSe communication), and can be applied to Model A and Model B methods as relay discovery methods. Model A can refer to the discovery process of the relay sending an announcement message, and Model B can refer to the discovery process of the end UE or remote UE sending a request message.

[0068] This disclosure supports multiple transmission paths for reliable communication. For example, when performing data path discovery, the UE can perform multiple path discovery procedures according to service requirements, and can store and / or maintain multiple discovered paths to use another path if the currently used path is interrupted.

[0069] This disclosure supports multiple data transmissions for reliable communication. For example, when transmitting data, the UE can transmit the same data multiple times as needed for service.

[0070] This disclosure supports flooding, which refers to the direct transmission of data without configuring a data transmission path. In a flooding scheme, the process of discovering a data transmission path can be omitted, and data can be transmitted to all UEs based on service demand. However, flooding can cause network congestion or excessive traffic, and may result in significant battery consumption for UEs. Consequently, data transmission using flooding can be very strictly limited and can only be used in highly urgent scenarios (e.g., earthquakes, tsunamis, large-scale fires, etc.).

[0071] Figure 5 The process of one embodiment of the present disclosure is illustrated, wherein a UE supporting 5G ProSe performs data path discovery to transmit data.

[0072] Reference Figure 5 This implementation can be described based on the scenario of discovering 5G ProSe UE-to-UE relay using Model B.

[0073] The 5G ProSe UE that initiates the discovery of a 5G ProSe UE to a UE relay can be referred to as the discovering 5G ProSe UE. The peer UE of the discovering UE can be referred to as the discovered 5G ProSe UE. In a multi-hop discovery environment, the request message for a 5G ProSe UE to a UE relay can include not only existing parameters but also additional parameters.

[0074] Existing parameters can be referred to as the 5G ProSe UE-to-UE relay discovery parameter group. New parameters added for multi-hop purposes can be referred to as the PC5 multi-hop parameter group. Of course, the above names are just examples, and other names can be used. Furthermore, there is no distinction between existing parameters and additional parameters.

[0075] Existing parameters may include at least one of the following: discovery message type, relay service code (RSC), user information identifier (discoverer), user information identifier (discoverer), source layer 2 identifier, or destination layer 2 identifier.

[0076] Additional parameters may include user information identifier (relay), hop limit, hop count, mobility level, battery status, load status, original source layer 2 identifier, number of repetitions, or at least one of the source layer 2 identifier list.

[0077] The hop count limit restricts the number of hops a relayed message can be sent. This limit prevents messages from being relayed across the network, thus preventing network congestion. Furthermore, since the appropriate distance to the discovered 5G ProSe UE can vary depending on each RSC (e.g., service), the hop count limit value can be adjusted to discover suitable discovered 5G ProSe UEs. While the hop count limit value can be determined by the ProSe application server and network policies, it can also be manually determined by authorized personnel based on field conditions (e.g., disaster situations). Moreover, the hop count limit value manually determined by authorized personnel takes precedence over the value determined by the ProSe application server and network policies. Different hop count limit values ​​can be assigned based on RSC and field conditions. For example, a relatively small hop count limit value can be assigned to a service used in a small disaster situation, such as a traffic accident, while a relatively large hop count limit value can be assigned in a disaster situation involving a large area, such as an earthquake. Furthermore, when the disaster area is a narrow region, such as an island with low UE density, a relatively small hop count limit value can be assigned, while when the disaster area is a vast region, such as a large city with high UE density, a larger hop count limit value can be assigned. Additionally, to avoid network congestion, the discovering 5G ProSe UE can use a value greater than or equal to the minimum hop count limit to send the initial 5G ProSe UE to UE relay discovery request message. Alternatively, if the discovering 5G ProSe UE does not receive a 5G ProSe UE to UE relay discovery response message within a specified time period (timer), the discovering 5G ProSe UE can reconfigure the hop count limit value to a value between the minimum and maximum values, or reconfigure it to the maximum value, based on the RSC and disaster area conditions, and can resend the message. Furthermore, depending on the site conditions (e.g., disaster type, area size, urgency level, etc.), the hop count limit value can be manually configured by authorized personnel to a value greater than the maximum value, and the message can be resent. Of course, this disclosure is not limited to the above examples, and the hop count limit value can be determined considering various conditions.

[0078] The hop count represents a value that increments with each hop and indicates the number of hops a request message has traversed before reaching the discoverer 5G ProSe UE. When the discoverer 5G ProSe UE subsequently receives request messages transmitted via multiple paths, the hop count value can serve as the basis for selecting which path to receive the message through.

[0079] The values ​​for mobility level, battery status, and load status are input solely from the 5G ProSe UE to the UE relay and can be used to maintain a stable overall path when configuring relay paths between the discovering 5G ProSe UE and the discovering 5G ProSe UE. Mobility level can be a value indicating the mobility of the relay (e.g., the degree of mobility the relay possesses). Battery status can indicate the available battery capacity of the relay. The relay is also a mobile device and can operate on battery power. Load status can indicate the load of the relay connection service being handled by the relay. Since each relay has a different location and different types and numbers of supported connection services, the load handled by each relay can be different. The above information (e.g., mobility level, battery status, and load status) can be used as basic information to determine the selection of a message received via one of multiple transmission paths when the discovering 5G ProSe UE subsequently receives a request message transmitted via multiple paths. For example, in the case where a path is configured by a relay with high mobility, frequent relay reselection may occur due to the relay's movement. Furthermore, if the route is configured using a relay with a small battery capacity, the relay may shut down, and relay reselection may be necessary. Of course, the above examples are not limiting, and other parameters can be added to or substituted for the parameters determined above.

[0080] The value of the original source layer 2 identifier can be used to prevent relays from redundantly relaying request messages sent by the same discoverer. The value of the original source layer 2 identifier can be assigned by the first relay to receive the request message from the discoverer to the discoverer's source layer 2 identifier in the 5G ProSe UE-to-UE relay discovery parameter group (e.g., the discoverer's source layer 2 identifier value). Subsequent relays can perform relays without modifying the value of the original source layer 2 identifier.

[0081] The repetition count can be configured to enable multiple path discovery during data path discovery. The UE can use the original source layer 2 identifier value to prevent network congestion caused by retransmission of previously sent request messages. When the repetition count is configured, even if the UE has previously sent a request message, as long as the repetition count is not "0", the UE can retransmit the request message after decrementing the repetition count by 1 and resetting the value. When the repetition count is "0", the UE can avoid retransmitting the request message.

[0082] The source layer 2 identifier list can be a list of layer 2 identifiers of relays that have sent request messages. The source layer 2 identifier list can indicate relays configured in the data path.

[0083] Refer again Figure 5 This describes the transmission process of a 5G ProSe UE-to-UE relay discovery request message. The discovering UE can generate and send a 5G ProSe UE-to-UE relay discovery request message to communicate with the discovered UE using one or more 5G ProSe UE-to-UE relays. In the 5G ProSe UE-to-UE relay discovery request message, the parameter values ​​of the 5G ProSe UE-to-UE relay discovery parameter group (including at least one of the following parameters) can be configured as follows: Discovery message type: 5G ProSe UE-to-UE relay discovery request User information identifier: The discoverer's user information identifier User information identifier: User information identifier of the discoverer RSC Source Layer 2 identifier: assigned by the discoverer Destination Layer 2 identifier: Default destination Layer 2 identifier The parameters of the PC5 multi-hop parameter group in the 5G ProSe UE-to-UE relay discovery request message (including at least one of the following parameters) can be configured as follows: User information identifier: Relay user information identifier Hop limit: Values ​​based on the parameters described above. Jump count: 0 Mobility level: Configured only by the relay (excluding configuration by the end UE). Battery status: Configured only by the relay (configuration by the end UE is not excluded). Load status: Configured only by the relay (configuration by the end UE is not excluded). Original source layer 2 identifier: Only configured by relay Number of repetitions Source Layer 2 Identifier List The request message sent by the discovering UE can be received by one or more relays located around the discovering UE. The destination Layer 2 identifier of the request message is configured to default, so all relays can receive the request message. The relay can receive the request message and identify the value of the RSC in the message. If the relay is providing connectivity services, the relay can modify the received 5G ProSe UE-to-UE relay discovery request message and retransmit the modified message. In this case, if the relay is one hop away from the discovering UE, the relay can modify the message as follows: The parameters for the 5G ProSe UE-to-UE relay discovery parameter group can be configured as follows. Of course, it is not limited to the following examples: Discovery message type: 5G ProSe UE-to-UE relay discovery request User information identifier: The discoverer's user information identifier User information identifier: User information identifier of the discoverer User information identifier: Relay user information identifier RSC Source Layer 2 identifier: allocated by relay Destination Layer 2 identifier: Default destination Layer 2 identifier The parameters for the PC5 multi-hop parameter group can be configured as follows. Of course, it is not limited to the following examples.

[0084] Hop limit: Received hop limit value - 1

[0085] Hop count: The received hop count value + 1

[0086] Mobility level: The mobility level of the relay

[0087] Battery status: Relay battery status

[0088] Load status: Relay load status

[0089] Original source layer 2 identifier: Source layer 2 identifier of the discoverer

[0090] Number of repetitions: numerical value (if the relay is a repeating relay, then this value is -1).

[0091] Source Layer 2 Identifier List: Identifier (add its own Source Layer 2 identifier)

[0092] If the relay is two hops away from the discoverer, the message can be modified as follows.

[0093] The parameters for the 5G ProSe UE-to-UE relay discovery parameter group can be configured as follows. Of course, it is not limited to the following examples.

[0094] Discovery message type: 5G ProSe UE-to-UE relay discovery request

[0095] User information identifier: The discoverer's user information identifier

[0096] User information identifier: User information identifier of the discoverer

[0097] User information identifier: Relay user information identifier

[0098] RSC

[0099] Source Layer 2 identifier: allocated by relay

[0100] Destination Layer 2 identifier: Default destination Layer 2 identifier

[0101] The parameters for the PC5 multi-hop parameter group can be configured as follows. Of course, it is not limited to the following examples.

[0102] Hop limit: Received hop limit value - 1

[0103] Hop count: The received hop count value + 1

[0104] Mobility level: A list of existing relay mobility levels, as well as the mobility level of the relay itself.

[0105] Battery Status: A list of existing relay battery statuses, as well as the relay's own battery status.

[0106] Load Status: A list of existing trunk load statuses, as well as the load status of the trunk itself.

[0107] Original source layer 2 identifier: The discoverer's source layer 2 identifier (unchanged)

[0108] Number of repetitions: numerical value (if the relay is a repeating relay, then the numerical value is reduced by 1).

[0109] Source Layer 2 Identifier List: Identifier (add its own Source Layer 2 identifier)

[0110] A relay receiving a request message containing the original source layer 2 identifier can determine whether the received request message is a duplicate message based on at least one of the following: the discoverer user information identifier, RSC, or the original source layer 2 identifier. If the message is determined to be a duplicate message, the relay can determine whether to retransmit the request message additionally based on the value of the repetition count. If the repetition count value is "0", the relay may not perform additional retransmission of the request message. The relay can immediately retransmit the first received request message and discard subsequent received duplicate messages. Alternatively, the relay can select whether to retransmit (or discard) duplicate messages received within a predetermined time period by considering at least one of the following: hop count, relay mobility, battery status, and load status. Furthermore, the relay can select whether to retransmit the request message (or discard subsequent received duplicate messages) by considering the received signal strength. For example, in Figure 5In this process, the relay can retransmit the first received message in the order of arrival time and discard subsequent duplicate messages. If the repetition count is "1" or greater, the relay can decrement the repetition count by 1 and reconfigure the reduced value in the duplicate message (e.g., if the repetition count is 2, it can be reconfigured to 1), and can retransmit the duplicate message additionally. As mentioned above, the relay can configure multiple data paths through additional retransmissions. At the last relay, the hop count limit for duplicate messages can be 0, thus eliminating the need for further retransmissions. The discovered 5G ProSe UE can receive the request message through multiple transmission paths. The discovered 5G ProSe UE that receives the request message through multiple transmission paths can identify the RSC value and user information identifier (e.g., the discoverer) value contained in the request message. The discovered 5G ProSe UE can determine the communication path with the discoverer UE based on the identified RSC value and user information identifier (discoverer) value in the request message. For example, the discovered 5G ProSe UE can determine the communication path with the discovering UE by considering at least one of hop count, mobility level, battery status, or load status. Furthermore, the discovered 5G ProSe UE can further consider message arrival order or the radio status of the last-hop relay. Figure 5 The example in the text illustrates the operation of the discovered 5G ProSe UE selecting the path with the fewest hop counts.

[0111] Data communication paths between 5G ProSe UEs can be discovered through multiple other relays. A UE (e.g., a 5G ProSe UE) can select a discovered path to send and / or receive data. However, since the currently used data path may be disconnected for various reasons, a UE (e.g., a 5G ProSe UE) can store multiple discovered data transmission paths in a table format as shown below. However, the configuration in Table 1 and the elements included in Table 1 are merely examples and are not limited thereto.

[0112] Table 1

[0113] The path number can be the index number of the discovered data transmission path.

[0114] A relay list can be a list of Layer 2 identifiers for relays that transmit data in a data path.

[0115] A public trunk can be identified as a Layer 2 trunk that is contained in another path.

[0116] Priority can be a value calculated considering at least one of the following: number of hops in the path, mobility level, battery status, or load status, and can be recalculated using a score.

[0117] To improve data transmission reliability, a UE can transmit the same data through two or more data transmission paths. For example, a UE can select one data transmission path from multiple data transmission paths by considering at least one of the priorities of each path and the number of common relays. For instance, a UE can select the path with the highest priority (e.g., path number 1) or the path with the fewest common relays (e.g., path number 4) among multiple data transmission paths. As another example, a UE can select path number 3 as the data transmission path by considering both priority and common relays among multiple data transmission paths. Of course, this is not limited to the above examples; paths with lower priorities can also be selected as data transmission paths.

[0118] Figure 6 This illustration depicts a scenario according to an embodiment of the present disclosure, in which the same data is redundantly transmitted through multiple data transmission paths. In this case, redundant transmission may refer to a scheme in which the same data is transmitted simultaneously through multiple data transmission paths. However, simultaneous transmission is merely an example and is not necessarily limited to simultaneous transmission.

[0119] Reference Figure 6 Whether to utilize multiple data transmission paths for redundant data transmission can be determined based on service requirements (e.g., RSC). For example, Figure 6 In this example, a UE (e.g., a 5G ProSe end UE) is shown transmitting the same data three times using three discovered data transmission paths. If at least one of the transmission paths remains open, the data can be transmitted to the peer UE.

[0120] Figure 7 This illustration shows a flooding-based data transmission scheme according to an embodiment of the present disclosure, in which data is transmitted directly without performing data path discovery.

[0121] Reference Figure 7 The UE (e.g., a source 5G ProSe UE) can flood data according to service requirements (e.g., RSC). For flooded transmission, the data transmission message may include a flooding indication and the data to be transmitted. The UE can configure the target user information identifier as the identifier of the UE to which data is to be transmitted, or configure it as an identifier corresponding to all UEs, and can transmit data accordingly. The UE may additionally include hop count limit and repetition count fields to reduce congestion within the network. Figure 7 There are two methods for handling duplicate messages. When a duplicate message has already been transmitted via a different path, it can be retransmitted. However, duplicate messages exchanged directly between two relays may not be retransmitted.

[0122] Figure 8 The structure of a UE according to an embodiment of this disclosure is shown.

[0123] A UE according to embodiments of this disclosure may include: a processor 820 for controlling the overall operation of the UE, a transceiver 800 including a transmitter and a receiver, and a memory 810. Of course, the examples shown above are not limiting; the UE may include more than... Figure 8 The components shown are fewer or more components.

[0124] According to embodiments of this disclosure, transceiver 800 can send / receive signals with a network entity or other UEs. Signals sent / received with the network entity may include control information and data. Additionally, transceiver 800 can receive signals via a wireless channel, output them to processor 820, and transmit signals output from processor 820 via a wireless channel.

[0125] According to embodiments of this disclosure, the processor 820 can control the UE to perform operations according to any of the above embodiments. The processor 820, memory 810, and transceiver 800 do not necessarily need to be implemented as discrete modules, but can be implemented as a single component unit, such as a single chip. Furthermore, the processor 820 and transceiver 800 can be electrically connected to each other. Additionally, the processor 820 can be an application processor (AP), a communication processor (CP), a circuit, a dedicated circuit, or at least one processor.

[0126] According to embodiments of this disclosure, memory 810 may store data such as basic programs, application programs, and configuration information for UE operation. Specifically, memory 810 may provide the stored data upon request from processor 820. Memory 810 may include storage media such as ROM, RAM, hard disk, CD-ROM, and DVD, or combinations of storage media. In addition, memory 810 may include multiple memories. Furthermore, processor 820 may execute the above-described embodiments of this disclosure based on programs stored in memory 810 for executing embodiments.

[0127] Figure 9 The structure of a base station or network entity according to an embodiment of this disclosure is shown.

[0128] A network entity according to embodiments of this disclosure may include a processor 920 for controlling the overall operation of the network entity, a transceiver 900 including a transmitter and a receiver, and a memory 910. Of course, the above examples are not limiting; the network entity may include more than... Figure 9 The diagram shows fewer or more components.

[0129] According to embodiments of this disclosure, transceiver 910 can transmit / receive signals with at least one of other base stations (or other network entities) or UEs. Signals transmitted / received with at least one of other base stations (or other network entities) or UEs may include control information and data.

[0130] According to embodiments of this disclosure, processor 920 can control network entities to perform operations according to any of the above embodiments. Of course, processor 920, memory 910, and transceiver 900 do not necessarily need to be implemented as discrete modules, but can be implemented as a single component unit, such as a single chip. Furthermore, processor 920 and transceiver 900 can be electrically connected to each other. Additionally, processor 920 can be an application processor (AP), a communication processor (CP), a circuit, a dedicated circuit, or at least one processor.

[0131] According to embodiments of this disclosure, memory 910 may store basic programs, application programs, and data such as configuration information for the operation of network entities. Specifically, memory 910 may provide the stored data upon request from processor 920. Memory 910 may include storage media such as ROM, RAM, hard disk, CD-ROM, and DVD, or combinations of storage media. In addition, memory 910 may include multiple memories. Furthermore, processor 920 may execute the above-described embodiments of this disclosure based on programs stored in memory 910 for executing embodiments.

[0132] It should be noted that the above configuration diagrams, schematic diagrams of control / data signal transmission methods, schematic diagrams of operation processes, and structural diagrams are not intended to limit the scope of this disclosure. That is, all components, entities, or operational steps described in the embodiments of this disclosure should not be construed as essential elements for implementing this disclosure. Even if only some of these elements are included, this disclosure can be implemented without prejudice to its substance. Furthermore, the above embodiments can be combined as needed. For example, the methods proposed in this disclosure can be partially combined with each other to operate network entities and terminals.

[0133] The aforementioned operations of the base station or terminal can be implemented by providing any unit of the base station or terminal equipment with a storage device containing the corresponding program code. That is, the controller of the base station or terminal equipment can read and execute the program code stored in the storage device through a processor or central processing unit (CPU) to perform the aforementioned operations.

[0134] Various units or modules of physical entities, base station equipment, or terminal equipment can be operated using hardware circuits, firmware, or hardware circuits, such as software and / or combinations of hardware and firmware and / or software embedded in a machine-readable medium, for example, based on complementary metal-oxide-semiconductor logic circuits. For example, various electrical structures and methods can be implemented using transistors, logic gates, and circuits such as application-specific integrated circuits (ASICs).

[0135] When implemented in software, a computer-readable storage medium may be provided for storing one or more programs (software modules). The one or more programs stored in the computer-readable storage medium may be configured to be executed by one or more processors within an electronic device. The at least one program includes instructions that cause the electronic device to perform the methods defined in the appended claims and / or disclosed herein, according to various embodiments of this disclosure.

[0136] These programs (software modules or software) can be stored in non-volatile memory, including random access memory and flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), magnetic disk storage devices, optical disc read-only memory (CD-ROM), digital versatile optical disc (DVD), or other types of optical storage devices, or magnetic tape. Alternatively, any combination of some or all of the above-mentioned memories can constitute a memory for storing programs. Furthermore, an electronic device may contain multiple such memories.

[0137] Furthermore, the program can be stored in an attachable storage device that can be accessed by the electronic device via a communication network, such as the Internet, intranet, local area network (LAN), wide area network (WLAN), storage area network (SAN), or a combination thereof. Such a storage device can access the electronic device via an external port. Additionally, a separate storage device on the communication network can access the device used to execute embodiments of this disclosure.

[0138] In the specific embodiments described above, the elements included in this disclosure are expressed in a singular or plural form depending on the specific implementation presented. However, the singular or plural form is appropriately chosen as presented for ease of description, and this disclosure is not limited to elements expressed in a singular or plural form. Therefore, elements expressed in a plural form may include a single element, or elements expressed in a singular form may include multiple elements.

[0139] Although specific embodiments have been described in the detailed description of this disclosure, it will be apparent that various modifications and variations can be made without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the embodiments described herein, but rather to the appended claims and their equivalents. That is, those skilled in the art will understand that other variations based on the technical concept of this disclosure can also be implemented. Furthermore, the above embodiments can be combined when necessary. For example, the methods proposed in this disclosure can be partially combined with each other to operate network entities and terminals. And, although the above embodiments are described based on 5G or NR systems, other variations based on the technical concept of the embodiments can also be implemented in other communication systems such as LTE, LTE-A, or LTE-A-Pro systems.

[0140] Although specific embodiments have been described in the detailed description of this disclosure, it will be apparent that various modifications and variations can be made without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the embodiments described herein, but should be defined by the appended claims and their equivalents.

Claims

1. A method performed by a first relay terminal in a wireless communication system, the method comprising: Receive a first message from the first terminal for discovering the second terminal; as well as Based on the first message, a second message is sent to the second relay terminal. Among them, the first terminal, the second terminal, the first relay terminal, and the second relay terminal are terminals that support ProSe based on proximity. The first message includes first information for relay services and second information for multi-hop relays.

2. The method according to claim 1, wherein, The first information includes at least one of the following: the type of the first message, service-related information, first terminal-related information, second terminal-related information, identification information of the first relay terminal, or identification information of the second relay terminal.

3. The method according to claim 1, wherein, The second information includes a hop count limit, a hop count, a repeat count of the first message, status information of at least one relay terminal containing the first relay terminal, an identifier of the at least one relay terminal, or at least one item from a list of relay terminals containing the at least one relay terminal, and The at least one relay terminal is located on the transmission path of the first message.

4. The method according to claim 3, wherein, The status information of the at least one relay terminal includes at least one of mobility-related information, battery status information, or data status information.

5. The method according to claim 2, wherein, Whether the first message is duplicated is determined based on the information related to the second terminal, the service-related information, and the identification information of the first relay terminal.

6. The method according to claim 3, further comprising: The transmission of the second message is identified based on the repetition count of the first message.

7. The method according to claim 6, further comprising: If the duplicate count of the first message is 0, discard at least one of the duplicate first messages; as well as If the repetition count of the first message is not zero, the second message is generated.

8. The method according to claim 1, wherein, The data receiving path used to receive data from the second terminal is determined based on the first information and the second information, and The data receiving path includes candidate data receiving paths.

9. A first relay terminal in a wireless communication system, comprising: transceiver; as well as At least one controller connected to the transceiver Wherein, the at least one controller is configured as follows: Receive a first message from the first terminal for discovering the second terminal; and Based on the first message, a second message is sent to the second relay terminal. Among them, the first terminal, the second terminal, the first relay terminal, and the second relay terminal are terminals that support ProSe based on proximity. The first message includes first information for relay services and second information for multi-hop relays.

10. The first relay terminal according to claim 9, wherein, The first information includes at least one of the following: the type of the first message, service-related information, first terminal-related information, second terminal-related information, identification information of the first relay terminal, or identification information of the second relay terminal.

11. The first relay terminal according to claim 9, wherein, The second information includes a hop count limit, a hop count, a repeat count of the first message, status information of at least one relay terminal containing the first relay terminal, an identifier of the at least one relay terminal, or at least one item from a list of relay terminals containing the at least one relay terminal, and The at least one relay terminal is located on the transmission path of the first message.

12. The first relay terminal according to claim 11, wherein, The status information of the at least one relay terminal includes at least one of mobility-related information, battery status information, or data status information.

13. The first relay terminal according to claim 10, wherein, Whether the first message is duplicated is determined based on the information related to the second terminal, the service-related information, and the identification information of the first relay terminal.

14. The first relay terminal according to claim 11, wherein, The at least one controller is further configured to identify the transmission of the second message based on the repetition count of the first message.

15. The first relay terminal according to claim 14, wherein, The at least one controller is further configured to: If the duplicate count of the first message is 0, discard at least one of the duplicate first messages; and If the repetition count of the first message is not zero, the second message is generated.

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