Method and apparatus for supporting multipath relay in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. More specifically, the present disclosure provides a method performed by a first terminal in a wireless communication system, the method comprising the steps of: receiving, from a second terminal, a signal for measuring a sidelink with the second terminal; and transmitting a measurement report including a measurement result based on the signal to the second terminal or the base station, where the measurement report may include information indicating a measurement unit on which the measurement result is based.

Description

Technical Field

[0001] This disclosure relates to a wireless communication system, and more specifically, to a method and apparatus for using multipath relay in a wireless communication system. Background Technology

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

[0003] At the outset of 5G mobile communication technology development, in order to support services and meet performance requirements associated with enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine-type communication (mMTC), ongoing standardization efforts were underway regarding the following: beamforming and massive MIMO for mitigating radio wave path loss and increasing radio wave transmission distance in mmWave; a set of supporting parameters for dynamic operation (e.g., operating multiple subcarrier spacings) for efficient utilization of mmWave resources and time slot formats; initial access technologies for supporting multi-beam transmission and broadband; the definition and operation of BWP (bandwidth portion); new channel coding methods (such as LDPC (low-density parity-check) codes for large-volume data transmission and polar codes for highly reliable transmission of control information); L2 preprocessing; and network slicing for providing dedicated networks for specific services.

[0004] Currently, given the services to be supported by 5G mobile communication technology, discussions are underway regarding improvements and performance enhancements to the initial 5G mobile communication technology. Furthermore, physical layer standardization exists for technologies such as: V2X (Vehicle-to-Everything) for assisting autonomous vehicles in determining driving based on information transmitted by the vehicle regarding its location and status, enhancing user convenience; NR-U (New Radio Unlicensed) for system operation designed to comply with various regulatory requirements in unlicensed frequency bands; NR UE power saving; non-terrestrial networks (NTN) (which are UE-satellite direct communication used to provide coverage in areas where communication with terrestrial networks is unavailable); and positioning.

[0005] Furthermore, ongoing standardization exists in the air interface architecture / protocol for technologies such as: Industrial Internet of Things (IIoT) to support new services through interoperability and convergence with other industries; IAB (Integrated Access and Backhaul) for nodes to provide network service area extension by supporting wireless backhaul and access links 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 the random access process. There is also ongoing standardization of 5G baseline architectures (e.g., service-based architectures or service-based interfaces) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, as well as system architectures / services for Mobile Edge Computing (MEC) to receive services based on UE location.

[0006] With the commercialization of 5G mobile communication systems, the already exponentially growing number of connected devices will connect to the communication network, and correspondingly, enhanced functionality and performance of 5G mobile communication systems, as well as the integrated operation of connected devices, are expected to be necessary. To this end, new research is planned related to extended reality (XR) for effectively supporting AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality), 5G performance improvements and complexity reductions through the utilization of artificial intelligence (AI) and machine learning (ML), AI service support, metaverse service support, and drone communication.

[0007] Furthermore, this development of 5G mobile communication systems will serve as a foundation for developing not only new waveforms for providing coverage in the terahertz band of 6G mobile communication technology, such as full-dimensional MIMO (FD-MIMO), multi-antenna transmission technologies like array antennas and massive MIMO, metamaterial-based lenses and antennas for improving terahertz band signal coverage, high-dimensional spatial multiplexing technologies using 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 enhancing system networks, AI-based communication technologies for system optimization by leveraging satellites and AI (artificial intelligence) from the design phase and internalizing end-to-end AI support capabilities, and next-generation distributed computing technologies for providing services at complexity levels exceeding the limitations of UE operational capabilities by utilizing ultra-high-performance communication and computing resources. Summary of the Invention

[0008] [Technical Issues]

[0009] This disclosure provides a method and apparatus for supporting multipath relay in a wireless communication system, thereby providing multipath relay services.

[0010] The technical topics pursued in this disclosure may not be limited to those described above, and those skilled in the art to which this disclosure pertains may clearly understand from the following description other technical topics not mentioned herein.

[0011] Solution to the problem

[0012] This disclosure provides a method performed by a first terminal in a wireless communication system, the method comprising: receiving from a second terminal a signal for measuring a side link with the second terminal; and sending to the second terminal or a base station a measurement report including measurement results based on the signal, wherein the measurement report may include information indicating the measurement unit on which the measurement results are based.

[0013] Additionally, this disclosure provides a method performed by a second terminal in a wireless communication system, the method comprising: sending a signal to a first terminal for measuring a side link with the first terminal; and receiving from the first terminal a measurement report including measurement results based on the signal, wherein the measurement report may include information indicating the measurement unit on which the measurement results are based.

[0014] Additionally, this disclosure provides a first terminal in a wireless communication system, the first terminal including: a transceiver; and a controller connected to the transceiver, wherein the controller is configured to: receive from a second terminal a signal for measurements regarding a side link with the second terminal; and send to the second terminal or a base station a measurement report including measurement results based on the signal, wherein the measurement report may include information indicating the measurement unit on which the measurement results are based.

[0015] Additionally, this disclosure provides a second terminal in a wireless communication system, the second terminal comprising: a transceiver; and a controller connected to the transceiver, wherein the controller is configured to: send a signal to a first terminal for measurements of a side link with the first terminal; and receive from the first terminal a measurement report including measurement results based on the signal, wherein the measurement report may include information indicating the measurement unit on which the measurement results are based.

[0016] [Beneficial effects of the invention]

[0017] According to embodiments of this disclosure, apparatus and methods can be provided to effectively provide services in a wireless communication system.

[0018] The beneficial effects that can be obtained from this disclosure may not be limited to the effects described above, and those skilled in the art to which this disclosure pertains may clearly understand from the following description other effects not mentioned herein. Attached Figure Description

[0019] Figure 1 The structure of a next-generation mobile communication system according to an embodiment of this disclosure is shown.

[0020] Figure 2 The user plane radio protocol structure of a next-generation mobile communication system according to an embodiment of the present disclosure is shown.

[0021] Figure 3 The control plane radio protocol structure of a next-generation mobile communication system according to various embodiments of the present disclosure is shown.

[0022] Figure 4 The structure of a base station in a wireless communication system according to an embodiment of the present disclosure is shown.

[0023] Figure 5 The structure of a UE in a wireless communication system according to an embodiment of the present disclosure is shown.

[0024] Figure 6a Examples of sidelink communication scenarios in wireless communication systems according to various embodiments of the present disclosure are shown.

[0025] Figure 6b Examples of sidelink communication scenarios in wireless communication systems according to various embodiments of the present disclosure are shown.

[0026] Figure 6c Examples of sidelink communication scenarios in wireless communication systems according to various embodiments of the present disclosure are shown.

[0027] Figure 6d Examples of sidelink communication scenarios in wireless communication systems according to various embodiments of the present disclosure are shown.

[0028] Figure 6e Examples of sidelink communication scenarios in wireless communication systems according to various embodiments of the present disclosure are shown.

[0029] Figure 7a Examples of transmission schemes for sidelink communication in wireless communication systems according to various embodiments of the present disclosure are shown.

[0030] Figure 7b Examples of transmission schemes for sidelink communication in wireless communication systems according to various embodiments of the present disclosure are shown.

[0031] Figure 8 An example of a sidelink resource pool in a wireless communication system according to an embodiment of the present disclosure is illustrated.

[0032] Figure 9 An example of a signal flow for allocating sidelink transmission resources in a wireless communication system, according to embodiments of the present disclosure, is shown.

[0033] Figure 10Another example of a signal flow for allocating sidelink transmission resources in a wireless communication system, according to embodiments of the present disclosure, is shown.

[0034] Figure 11 This is a diagram illustrating an example of a channel structure for a time slot used for sidelink communication in a wireless communication system according to an embodiment of the present disclosure.

[0035] Figure 12a This is a diagram illustrating the user plane radio protocol structure for multipath UE-network relay according to an embodiment of the present disclosure.

[0036] Figure 12b This is a diagram illustrating the control plane radio protocol structure for a multipath UE-network relay according to an embodiment of the present disclosure.

[0037] Figure 12c This is a diagram illustrating a user plane radio protocol architecture for multipath UE-network relay communication using UE-to-UE communication not defined in 3GPP, according to an embodiment of this disclosure.

[0038] Figure 12d This is a diagram illustrating the control plane radio protocol structure for multipath UE-network relay using UE-to-UE communication not defined in 3GPP, according to an embodiment of this disclosure.

[0039] Figure 13a This is a diagram illustrating a signal flow for sending threshold conditions for multipath UE-network relay to a relay UE according to an embodiment of the present disclosure.

[0040] Figure 13b This is a flowchart of an embodiment of the present disclosure for determining whether a UE meets the threshold conditions for multipath UE-network relay.

[0041] Figure 13c This is a flowchart of an embodiment of the present disclosure for determining whether a UE meets the threshold conditions for multipath UE-network relay.

[0042] Figure 14a This is a diagram illustrating a signal flow for sending threshold conditions for multipath UE-network relay to a remote UE according to an embodiment of the present disclosure.

[0043] Figure 14b This is a flowchart of an embodiment of the present disclosure for determining whether a UE meets the threshold conditions for multipath UE-network relay.

[0044] Figure 15 This is a flowchart illustrating a UE using a threshold for multipath UE-network relay operation according to an embodiment of the present disclosure.

[0045] Figure 16This is a flowchart illustrating a UE performing measurements and measurement reports in a multipath UE-network relay according to an embodiment of the present disclosure.

[0046] Figure 17 This is a flowchart illustrating a UE performing measurements and measurement reports in a multipath UE-network relay according to an embodiment of the present disclosure.

[0047] Figure 18 This is a flowchart illustrating a UE selecting or reselecting a relay UE during multipath UE-network relay operation according to an embodiment of the present disclosure.

[0048] Figure 19 This is a flowchart illustrating a UE reporting an indirect path failure to a base station during multipath UE-network relay operation according to an embodiment of the present disclosure. Detailed Implementation

[0049] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0050] In describing the embodiments, descriptions related to technical content known in the relevant art and not directly related to this disclosure will be omitted. This omission of unnecessary descriptions is intended to prevent obscuring the main ideas of this disclosure and to more clearly convey them.

[0051] For the same reason, some elements may be exaggerated, omitted, or shown schematically in the accompanying drawings. Furthermore, the dimensions of each element do not perfectly reflect the actual dimensions. In the corresponding drawings, the same or corresponding elements have the same or corresponding reference numerals.

[0052] The advantages and features of this disclosure, as well as the ways in which these advantages and features are realized, will become apparent from the following detailed description of embodiments in conjunction with the accompanying drawings. However, this disclosure is not limited to the embodiments set forth below, but can be implemented in various different forms. The following embodiments are provided only to fully disclose this disclosure and to enable those skilled in the art to understand its scope, which is defined only by the scope of the appended claims. Throughout the specification, the same or similar reference numerals denote the same or similar elements. Furthermore, in describing this disclosure, detailed descriptions of known functions or configurations will be omitted if it is determined that such detailed descriptions would unnecessarily obscure the subject matter of this disclosure. The terminology described below is based on the functional definitions in this disclosure and may vary depending on the user, user intent, or usage habits. Therefore, the definitions of the terms should be understood based on the overall content of the specification.

[0053] The following detailed description of embodiments of this disclosure is primarily directed to the New RAN (NR) as a radio access network and the Packet Core (5G system or 5G core network or next-generation core (NG core)) as a core network in the 5G mobile communication standard specified by the 3GPP (3rd Generation Partnership Project) mobile communication standardization organization. However, based on the determination of those skilled in the art, the main ideas of this disclosure can be applied to other communication systems with similar backgrounds with some modifications without significantly departing from the scope of this disclosure.

[0054] In the following description, for ease of description, some terms and names defined in 3GPP standards (standards for 5G, NR, LTE or similar systems) 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.

[0055] In the following description, for ease of description, terms for identifying access nodes, referring to network entities, referring to messages, referring to interfaces between network entities, referring to various types of identification information, etc., are used illustratively. Therefore, this disclosure is not limited to the terminology used herein, and other terms that refer to subjects with equivalent technical meanings may be used.

[0056] In the following description, a base station is an entity that allocates resources to a terminal, and may be at least one of a gNode B, eNode B, Node B, base station (BS), radio access unit, base station controller, and network node. A terminal may include a user equipment (UE), mobile station (MS), cellular phone, smartphone, computer, or multimedia system capable of performing communication functions. In this disclosure, "downlink (DL)" refers to the radio link used by the base station to transmit signals to the terminal, and "uplink (UL)" refers to the radio link used by the terminal to transmit signals to the base station.

[0057] In this document, it should be understood that each block in the flowchart diagram, and combinations of blocks in the flowchart, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, special-purpose computer, or other programmable data processing device to generate a machine, such that the instructions, executable by the processor of the computer or other programmable data processing device, create components for implementing the functions specified in one or more flowchart blocks. These computer program instructions can also be stored in a computer-usable or computer-readable storage medium capable of directing the computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the storage medium generate components for implementing the functions specified in the flowchart blocks. Figure 1An article of manufacture of instruction components that specify functions in one or more frames. These 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 performed on the computer or other programmable apparatus, thereby generating a process implemented by the computer, such that the executed instructions provide for implementing the process. Figure 1 The steps that specify the function in one or more boxes.

[0058] Furthermore, each box in the flowchart diagram may represent a module, segment, or code section, which includes one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur out of order. For example, depending on the functions involved, two boxes shown consecutively may actually execute substantially simultaneously, or these boxes may sometimes execute in reverse order.

[0059] As used in the embodiments of this disclosure, "unit" refers to a software element or hardware element that performs a predetermined function, such as a field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC). However, "unit" is not always limited to software or hardware. A "unit" may be configured to be stored in an addressable storage medium or to execute one or more processors. Thus, "unit" includes, for example, software elements, object-oriented software elements, class elements or task elements, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and parameters. Elements and functions provided by a "unit" may be combined into a smaller number of elements or "units," or divided into a larger number of elements or "units." Furthermore, elements and "units" may be implemented to reproduce one or more CPUs within a device or secure multimedia card. Additionally, a "unit" in the embodiments may include one or more processors.

[0060] 5G mobile communication technology defines a wide frequency band, enabling high transmission rates and new services. It can be implemented not only in "sub-6GHz" bands such as 3.5GHz, but also in "above 6GHz" bands, including 28GHz and 39GHz, known as millimeter waves (mmWave). Furthermore, 6G mobile communication technology (referred to as "super 5G systems") is being considered in terahertz bands (e.g., the 95GHz to 3THz band) to achieve transmission rates fifty times faster than 5G and ultra-low latency one-tenth that of 5G.

[0061] At the outset of 5G mobile communication technology development, in order to support services and meet performance requirements associated with enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine-type communication (mMTC), ongoing standardization efforts were underway regarding the following: beamforming and massive MIMO for mitigating radio wave path loss and increasing radio wave transmission distance in mmWave; a set of supporting parameters for dynamic operation (e.g., operating multiple subcarrier spacings) for efficient utilization of mmWave resources and time slot formats; initial access technologies for supporting multi-beam transmission and broadband; the definition and operation of BWP (bandwidth portion); new channel coding methods (such as LDPC (low-density parity-check) codes for large-volume data transmission and polar codes for highly reliable transmission of control information); L2 preprocessing; and network slicing for providing dedicated networks for specific services.

[0062] Currently, given the services to be supported by 5G mobile communication technology, discussions are underway regarding improvements and performance enhancements to the initial 5G mobile communication technology. Furthermore, physical layer standardization exists for technologies such as: Vehicle-to-Everything (V2X) to assist autonomous vehicles in determining driving based on information transmitted by the vehicle regarding its location and status, enhancing user convenience; New Radio Unlicensed (NR-U) designed to comply with various regulatory requirements in unlicensed frequency bands; NR UE power saving; Non-Terrestrial Networks (NTN) (which provides UE-satellite direct communication for coverage in areas where communication with terrestrial networks is unavailable); and positioning.

[0063] Furthermore, ongoing standardization exists in the air interface architecture / protocol for technologies such as: Industrial Internet of Things (IIoT) to support new services through interoperability and convergence with other industries; IAB (Integrated Access and Backhaul) for nodes to provide network service area extension by supporting wireless backhaul and access links 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 the random access process. There is also ongoing standardization of 5G baseline architectures (e.g., service-based architectures or service-based interfaces) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, as well as system architectures / services for Mobile Edge Computing (MEC) to receive services based on UE location.

[0064] With the commercialization of 5G mobile communication systems, the already exponentially growing number of connected devices will connect to the communication network, and correspondingly, enhanced functionality and performance of 5G mobile communication systems, as well as the integrated operation of connected devices, are expected to be necessary. To this end, new research is planned related to extended reality (XR) for effectively supporting AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality), 5G performance improvements and complexity reductions through the utilization of artificial intelligence (AI) and machine learning (ML), AI service support, metaverse service support, and drone communication.

[0065] Furthermore, this development of 5G mobile communication systems will serve as a foundation for developing not only new waveforms for providing coverage in the terahertz band of 6G mobile communication technology, such as full-dimensional MIMO (FD-MIMO), multi-antenna transmission technologies like array antennas and massive MIMO, metamaterial-based lenses and antennas for improving terahertz band signal coverage, high-dimensional spatial multiplexing technologies using 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 enhancing system networks, AI-based communication technologies for system optimization by leveraging satellites and AI (artificial intelligence) from the design phase and internalizing end-to-end AI support capabilities, and next-generation distributed computing technologies for providing services at complexity levels exceeding the limitations of UE operational capabilities by utilizing ultra-high-performance communication and computing resources.

[0066] In the following, this disclosure relates to methods and apparatus for supporting multipath (MP) relay, wherein direct and indirect paths are used simultaneously in UE-to-Network (U2N) relay. Specifically, multipath relay can be configured by a UE capable of operating as a relay UE in multipath relay, a UE capable of operating as a remote UE in multipath relay, and a base station supporting multipath relay. A multipath remote UE can communicate with the base station via multipath relay, and the UE-UE links and UE-base station links supporting this data flow can be collectively referred to as indirect paths. Furthermore, a multipath remote UE can communicate directly with the base station, and the UE-base station link used for direct communication can be referred to as a direct path. The base station can control multipath operation by adding, modifying, and deleting indirect and direct paths for multipath remote UEs. The base station can control the operation of multipath remote UEs and multipath relay UEs by configuring threshold conditions to be used in U2N and threshold conditions to be used in MP differently. The base station can send instructions to multipath remote UEs and multipath relay UEs to configure MP operation, thereby controlling which UEs are to be applied threshold conditions available for MP. For the purpose of controlling indirect and direct paths, a base station can configure multipath remote UEs and multipath relay UEs to periodically or under specific conditions report measurement results about surrounding base stations or surrounding UEs. The base station can configure the units to be measured for the UE (e.g., SL-RSRP or SD-RSRP), and the UE can explicitly notify the base station of the configured units to be measured in the measurement result report. For the purpose of managing the direct or indirect paths of multipath remote UEs, the base station may not perform relay UE selection or reselection for multipath remote UEs. Multipath remote UEs can notify the base station whether to use a UE-UE link based on upper-layer instructions.

[0067] Figure 1 The structure of a next-generation mobile communication system according to an embodiment of the present disclosure is shown.

[0068] refer to Figure 1 The radio access network of a next-generation mobile communication system (hereinafter referred to as NR or 5G) may include a next-generation base station (new radio node B, hereinafter referred to as NR gNB, gNB or base station) 120 and a new radio core network (NR CN) 110. User terminals (new radio user equipment, hereinafter referred to as NR UE or terminal) 150 may access external networks via NR gNB 120 and NRCN 110.

[0069] exist Figure 1In this context, the NR gNB 120 corresponds to the eNB 140 in an LTE system. The NR gNB 120 can connect to the NR UE 150 via radio channels and provides superior service compared to the eNB 140. In next-generation mobile communication systems, since all user services are served through a shared channel, it is necessary to collect status information such as the UE's buffer state, available transmit power state, and channel state, and to perform scheduling accordingly. The NR gNB 120 can serve as this device. Typically, one NR gNB 120 can control multiple cells. To achieve ultra-high-speed data transmission exceeding LTE, a bandwidth wider than the maximum bandwidth of LTE can be used. Orthogonal Frequency Division Multiplexing (OFDM) can be employed as the radio access technology, and beamforming technology can be integrated with it. Furthermore, an Adaptive Modulation and Coding (AMC) scheme can be used to determine the modulation scheme and channel coding rate based on the UE's channel state. The NR CN 110 can perform functions such as mobility support and QoS configuration. The NR CN 110 is responsible for various control functions and UE mobility management functions and can connect to multiple base stations. In addition, the next-generation mobile communication system can interoperate with the existing LTE system, and the NR CN110 can connect to the MME 130 via a network interface. The MME 130 can connect to the eNB 140.

[0070] Figure 2 The user plane radio protocol structure of a next-generation mobile communication system according to an embodiment of the present disclosure is shown.

[0071] refer to Figure 2 On the UE 210 side, the user plane radio protocol of the next-generation mobile communication system may include SDAP 211, PDCP 212, RLC 213, MAC 214, and / or PHY 215. On the gNB 220 side, the user plane radio protocol of the next-generation mobile communication system may include SDAP 221, PDCP 222, RLC 223, MAC 224, and / or PHY 225. In this disclosure, the expression "may include" can be replaced by the expression "may be configured by". For example, on the UE 210 side, the user plane radio protocol of the next-generation mobile communication system may consist of SDAP 211, PDCP 212, RLC 213, MAC 214, and / or PHY 215.

[0072] The functionality of SDAP 211 or 221 may include at least some of the following functions. However, this disclosure is not limited thereto.

[0073] - Mapping between Quality of Service (QoS) streams and data radio bearers

[0074] - Mark QoS Flow ID (QFI) in DL and UL packets

[0075] The main functions of PDCP 212 or 222 may include some of the following functions. However, this disclosure is not limited thereto.

[0076] - Data transmission (user plane or control plane)

[0077] - Maintenance of PDCP serial number (SN)

[0078] - Header compression and decompression using the ROHC protocol

[0079] -Header compression and decompression using the EHC protocol

[0080] - Uplink PDCP SDU compression and decompression: UDC based solely on DEFLATE

[0081] - Encryption and decryption

[0082] - Integrity protection and integrity verification

[0083] - SDU discarding based on timer

[0084] - Routes used for splitting bearers

[0085] -copy

[0086] - Reordering and sequential delivery

[0087] -unordered delivery

[0088] -Duplicate discarding

[0089] The main functions of RLC 213 or 223 may include some of the following functions. However, this disclosure is not limited thereto.

[0090] -Transmission of upper-layer PDUs

[0091] - Sequence numbers (UM and AM) independent of sequence numbers in PDCP

[0092] - Error correction via ARQ (AM only)

[0093] - Segmentation (AM and UM) and resegmentation (AM only) of RLC SDU

[0094] - SDU (AM and UM) Reorganization

[0095] -Duplicate detection (AM only)

[0096] -RLC SDU discard (AM and UM)

[0097] -RLC Reconstruction

[0098] - Protocol error detection (AM only)

[0099] The main functions of the MAC 214 or 224 may include some of the following functions. However, this disclosure is not limited thereto.

[0100] Mapping between logical channels and transport channels

[0101] - Multiplex MAC SDUs from one or more logical channels onto a transport block (TB) to be delivered to the physical layer on the transport channel.

[0102] - Demultiplex the MAC SDU from the physical layer of the transport channel into one or different logical channels.

[0103] - Scheduling Information Report

[0104] - Error correction via HARQ

[0105] -Logical channel prioritization

[0106] Priority handling between overlapping resources of a UE

[0107] PHY layer 215 or 225 can perform channel coding and modulation of upper-layer data to generate OFDM symbols, and can convert OFDM symbols into RF signals, which are then transmitted through an antenna. Additionally, PHY layer 215 or 225 can perform demodulation and channel decoding on the received OFDM symbols before transmitting them to the upper layer.

[0108] Figure 3 The control plane radio protocol structure of a next-generation mobile communication system according to various embodiments of the present disclosure is shown.

[0109] refer to Figure 3 On the UE 310 side, the control plane radio protocol of the next-generation mobile communication system may include Radio Resource Control (RRC) 311, PDCP 312, RLC 313, MAC 314 and / or PHY 315. On the gNB 320 side, the control plane radio protocol of the next-generation mobile communication system may include RRC 321, PDCP 322, RLC 323, MAC 324 and / or PHY 325.

[0110] The functionality of RRC 311 or 312 may include at least some of the following functions.

[0111] - Broadcast of system information related to AS and NAS

[0112] - Paging initiated by 5GC or NG-RAN

[0113] - The establishment and management of RRC connections between UE and NG-RAN, as well as the addition, modification and release of dual connections between carrier aggregation and NR or between NR and LTE (the establishment, maintenance and release of RRC connections between UE and NG-RAN, including: the addition, modification and release of carrier aggregation; the addition, modification and release of dual connections in NR or between E-UTRA and NR).

[0114] -Includes security features for key management

[0115] - Establishment, configuration, maintenance, and release of signaling radio bearers (SRBs) and data radio bearers (DRBs)

[0116] - UE mobility support (mobility functions include: handover and context delivery; UE cell selection and reselection and control of cell selection and reselection; inter-RAT mobility).

[0117] -QoS management function

[0118] - UE measurement reports and control of reports

[0119] - Detection and recovery of radio link failures

[0120] -NAS message transmission (NAS messages transmitted from UE to NAS / from NAS to UE)

[0121] The main functions of PDCP 312 or 322, RLC 313 or 323, MAC 314 or 324 and / or PHY 315 or 325 can be followed Figure 2 Examples.

[0122] Figure 4 The structure of a base station according to an embodiment of the present disclosure is shown.

[0123] refer to Figure 4 The base station may include a transceiver 405, a controller 410, and a storage device 415. The transceiver 405, controller 410, and storage device 415 can operate according to the communication method described above for the base station. Network devices may also correspond to the structure of the base station. However, the components of the base station are not limited to the examples described above. For example, the base station may include more or fewer components than those described above. For example, the base station may include a transceiver 405 and a controller 410. Furthermore, the transceiver 405, controller 410, and storage device 415 may be implemented as a single chip.

[0124] Transceiver 405 refers to a base station receiver and base station transmitter as a whole, capable of transmitting / receiving signals with the UE, other base stations, and other network devices. The transmitted / received signals may include control information and data. Transceiver 405 may transmit, for example, system information, synchronization signals, or reference signals to the UE. For this purpose, transceiver 405 may include an RF transmitter configured to up-convert and amplify the frequency of the transmitted signal, an RF receiver configured to perform low-noise amplification and down-convert the frequency of the received signal, etc. However, this is only one embodiment of transceiver 405, and the components of transceiver 405 are not limited to RF transmitters and RF receivers. Transceiver 405 may include wired / wireless transceivers and may include various components for transmitting / receiving signals. Additionally, transceiver 405 may receive signals via a communication channel (e.g., a radio channel), output them to controller 410, and transmit signals output from controller 410 via a communication channel. In addition, transceiver 405 can receive communication signals, output them to the processor, and transmit the signals output from the processor to the UE, other base stations, or other network entities via wired / wireless networks.

[0125] Storage device 415 can store programs and data required for the operation of the base station. Additionally, storage device 415 can store control information or data included in signals acquired by the base station. Storage device 415 may include storage media or combinations of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD. Furthermore, storage device 415 can store at least one of information transmitted / received via transceiver 405 and information generated by controller 410.

[0126] As used herein, controller 410 may be defined as a circuit, an application-specific integrated circuit (ASIC), or at least one processor. The processor may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper-layer applications such as applications. Controller 410 may control the overall operation of a base station according to embodiments set forth in this disclosure. For example, controller 410 may control the signal flow between various blocks to perform operations according to the flowchart described above.

[0127] Figure 5 The structure of a UE according to an embodiment of the present disclosure is shown.

[0128] refer to Figure 5The UE may include a transceiver 505, a controller 510, and a storage device 515. The transceiver 505, controller 510, and storage device 515 can operate according to the communication method described above for the UE. However, the components of the UE are not limited to the examples described above. For example, the UE may include more or fewer components than those described above. For example, the UE may include a transceiver 505 and a controller 510. Furthermore, the transceiver 505, controller 510, and storage device 515 may be implemented as a single chip.

[0129] Transceiver 505 refers to a UE receiver and UE transmitter integrated as a whole, capable of transmitting / receiving signals with a base station, other UEs, or network entities. Signals transmitted / received using the base station may include control information and data. Transceiver 505 may receive, for example, system information, synchronization signals, or reference signals from the base station. For this purpose, transceiver 505 may include an RF transmitter configured to up-convert and amplify the frequency of the transmitted signal, an RF receiver configured to perform low-noise amplification and down-convert the frequency of the received signal, etc. However, this is only one embodiment of transceiver 505, and the components of transceiver 505 are not limited to RF transmitters and RF receivers. Furthermore, transceiver 505 may include wired / wireless transceivers and may include various components for transmitting / receiving signals. Additionally, transceiver 505 may receive signals via a radio channel, output them to controller 510, and transmit signals output from controller 510 via a radio channel. Furthermore, transceiver 505 may receive communication signals, output them to a processor, and transmit signals output from the processor to network entities via a wired / wireless network.

[0130] The memory 515 can store programs and data required for the operation of the UE. Additionally, the memory 515 can store control information or data included in signals acquired by the UE. The storage device 515 may include storage media or combinations of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD.

[0131] As used herein, controller 510 may be defined as a circuit, an application-specific integrated circuit (ASIC), or at least one processor. The processor may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper-layer applications such as applications. Controller 510 may control the overall operation of the UE according to embodiments set forth in this disclosure. For example, controller 510 may control the signal flow between various blocks to perform operations according to the flowchart described above.

[0132] Figures 6a to 6e This is a diagram illustrating an example of a scenario concerning sidelink communication in a wireless communication system according to an embodiment of the present disclosure.

[0133] Figure 6aThe illustration shows a coverage (IC) scenario in which sidelink UEs 620 and 625 are located within the coverage area 610 of base station 600.

[0134] refer to Figure 6a Sidelink UEs 620 and 625 can receive data and control information from base station 600 via downlink (DL) or send data and control information to base station 600 via uplink (UL). The data and control information can be for sidelink communication or for general cellular communication other than sidelink communication. Additionally, sidelink UEs 620 and 625 can send and receive data and control information for sidelink communication via the sidelink. Furthermore, the first UE 620 can receive data and control information from base station 600 along a direct path (via DL or UL) or along an indirect path (via relay by the second UE 625). The first UE 620 can be referred to as a remote UE, and the second UE 625 can be referred to as a relay UE. The scenario where the first UE 620 accesses base station 600 via the second UE 625 can be referred to as UE-to-network (U2N) relay. Furthermore, the first UE 620 can simultaneously use both direct and indirect paths to send data and control information to / receive data and control information from the base station 600, a situation that can be referred to as multipath relay.

[0135] Figure 6b The illustration shows a case where the first UE 620 of the sidelink UE is located within the coverage area 610 of the base station 600, and the second UE 625 is located in a partial coverage (PC) outside the coverage area 610 of the base station 600.

[0136] refer to Figure 6b The first UE 620, located within the coverage area 610 of base station 600, can receive data and control information from base station 600 via downlink, or send data and control information to base station 600 via uplink. The second UE 625, located outside the coverage area of ​​base station 600, can receive data and control information directly from base station 600 without downlink, and can send data and control information directly to base station 600 without uplink. The second UE 625 can send data and control information to and receive data and control information for sidelink communication from the first UE 620 via sidelink.

[0137] Figure 6c The illustration shows an example of a situation where a sidelink UE (e.g., the first UE 620 and the second UE 625) is located outside the coverage of the base station 600 (out-of-coverage (OOC)).

[0138] refer to Figure 6c The first UE 620 and the second UE 625 can receive data and control information from the base station without using the downlink, and can send data and control information to the base station without using the uplink. The first UE 620 and the second UE 625 can send and receive data and control information for sidelink communication via the sidelink.

[0139] Figure 6d The illustration depicts a scenario where a first UE 620 and a second UE 625 performing sidelink communication are connected to different base stations (e.g., first base station 600 and second base station 605) (e.g., RRC connected state) or camped on them (i.e., RRC disconnected state, i.e., RRC idle or inactive state), and perform inter-cell sidelink communication. Reference Figure 6d The first UE 620 can be a sidelink transmitting UE, and the second UE 625 can be a sidelink receiving UE. Alternatively, the first UE 620 can be a sidelink receiving UE, and the second UE 625 can be a sidelink transmitting UE. The first UE 620 can receive a sidelink dedicated system information block (SIB) from a base station 600 to which the first UE 620 is connected (or on which the first UE 620 resides), and the second UE 625 can receive a sidelink dedicated SIB from a different base station 605 to which the second UE 625 is connected (or on which the second UE 625 resides). The information of the sidelink dedicated SIB received by the first UE 620 and the information of the sidelink dedicated SIB received by the second UE 625 can be different from each other. Therefore, in order to perform sidelink communication between UEs located in different cells, it may be necessary to further unify information or add methods for assuming and interpreting information. Furthermore, the first UE 620 can receive data and control information from the first base station 600 along a direct path via DL or UL, or it can receive data and control information from the second base station 605 along an indirect path via a relay of the second UE 625. The first UE 620 can be referred to as a remote UE, and the second UE 625 can be referred to as a relay UE. The scenario where the first UE 620 accesses the second base station 605 through the second UE 625 can be referred to as UE-network relay. Additionally, the first UE 620 can simultaneously use both direct and indirect paths to send data and control information to / receive data and control information from the first base station 600 and the second base station 605, and this scenario can be referred to as multi-path relay.

[0140] Figure 6e The illustration shows a scenario where the first UE 620, the second UE 625, and the third UE 630 perform sidelink communication by configuring UE-to-UE relay. (Reference) Figure 6eThe first UE 620 can be a source UE acting as a terminal UE in a UE-to-UE relay, and the third UE 630 can be a target UE acting as a terminal UE in a UE-to-UE relay. Alternatively, the first UE 620 can be a target UE acting as a terminal UE in a UE-to-UE relay, and the third UE 630 can be a source UE acting as a terminal UE in a UE-to-UE relay. The second UE 625 can be a relay UE that relays data between terminal UEs in a UE-to-UE relay. (As in...) Figures 6a to 6d In the example, the first UE 620, the second UE 625, and the third UE 630 can be in one of all possible combinations of the following: they are connected to the same or different base stations (e.g., in an RRC connected state) or reside on them (e.g., in an RRC disconnected state, i.e., an RRC idle or inactive state), they are performing inter-cell side-link communication, and they are in an OOC state.

[0141] Although, for ease of description, a sidelink system configured with two or three UEs (e.g., first UE 620, second UE 625, and third UE 630) has been described with reference to such a system. Figures 6a to 6e The examples provided are not limited to this disclosure and can also be applied to sidelink systems involving three or more UEs. Furthermore, the uplink and downlink between base station 600 and the sidelink UEs can be referred to as Uu interfaces, and the sidelink between sidelink UEs can be referred to as PC5 interfaces. Additionally, a sidelink UE located in OOC and not connected to a Uu interface of base station 600 can indirectly receive data and control information from base station 600 through a relay of another sidelink UE located in IC and having a Uu interface connected to base station 600. In the following description, uplink or downlink and Uu interfaces can be used interchangeably, and sidelinks and PC5 interfaces can be used interchangeably.

[0142] In this disclosure, UE can refer to a vehicle supporting vehicle-to-vehicle (V2V) communication, a vehicle supporting vehicle-to-pedestrian (V2P) communication or a pedestrian mobile phone (e.g., a smartphone), a vehicle supporting vehicle-to-network (V2N) communication, or a vehicle supporting vehicle-to-infrastructure (V2I) communication. Additionally, in this disclosure, UE can refer to a roadside unit (RSU) with UE functionality, an RSU with base station functionality, or an RSU with a portion of base station functionality and a portion of UE functionality. Furthermore, this can refer to a UE supporting Proximity Service (ProSe) and UE-to-UE relay (e.g., a terminal UE or relay UE in a UE-to-UE relay) or UE-to-network relay (e.g., a remote UE or relay UE in a UE-to-network relay).

[0143] Furthermore, in this disclosure, a base station can refer to a base station that supports both sidelink and general cellular communication, or a base station that only supports sidelink. The base station can be a 5G gNB, a 4G eNB, or an RSU. Therefore, in this disclosure, a base station can also be referred to as an RSU.

[0144] Figure 7a and Figure 7b An example of a transmission scheme for sidelink communication in a wireless communication system according to embodiments of the present disclosure is shown. Figure 7a The diagram illustrates a unicast scheme, and... Figure 7b The diagram illustrates a multicast scheme.

[0145] refer to Figure 7a The sending UE 700 and receiving UE 705 can perform one-to-one communication 710. For example... Figure 7a The transmission scheme used in this method can be called unicast communication.

[0146] Reference Figure 7b The sending UEs 730 and 745 can perform one-to-many communication with the receiving UEs 735, 740, 750, 755, and 760. For example... Figure 7b The transmission scheme in this context can be referred to as multicast or multi-cast.

[0147] exist Figure 7b In this configuration, the first UE 730, the second UE 735, and the third UE 740 can form a group to perform multicast communication, and the fourth UE 745, the fifth UE 750, the sixth UE 755, and the seventh UE 760 can form another group to perform multicast communication. UEs can perform multicast communication within their respective groups and can perform unicast, multicast, or broadcast communication with at least one other UE belonging to a different group. Although in Figure 7b Two groups are shown, but this disclosure is not limited to this and can be applied to situations where more groups are formed.

[0148] At the same time, despite Figure 7a or Figure 7b Although not shown in the diagram, sidelink UEs can also perform broadcast communication. Broadcast communication refers to a scheme in which all sidelink UEs receive data and control information sent by a sidelink sending UE via the sidelink. For example, if Figure 7b If the first UE 730 is the transmitting UE, then the other UEs 735, 740, 745, 750, 755 and 760 can receive the data and control information transmitted by the first UE 730.

[0149] It can support the above-mentioned sidelink unicast communication, multicast communication and broadcast communication in scenarios with coverage, partial coverage or outside coverage.

[0150] Figure 8An example of a sidelink resource pool in a wireless communication system according to an embodiment of the present disclosure is illustrated. A resource pool can be defined as a set of resources in the time and frequency domains used for sidelink transmission and reception.

[0151] The time-domain resource allocation unit (resource granularity) within the resource pool can be one or more Orthogonal Frequency Division Multiplexing (OFDM) symbols. Additionally, the frequency-domain resource allocation unit can be one or more Physical Resource Blocks (PRBs).

[0152] In the case of allocating resource pools in both the time and frequency domains, the region of resource configuration indicated by the diagonal line represents the region configured as a resource pool in both the time and frequency domains. Although this disclosure has been described based on the case of allocating resource pools in a discontinuous manner in the time domain, this disclosure is not limited thereto and can also be applied to the case of allocating resource pools in a continuous manner in the time domain. Furthermore, although this disclosure has been described based on the case of allocating resource pools continuously in the time domain, this disclosure is not limited thereto and can also be applied to the case of allocating resource pools in a discontinuous manner in the time domain.

[0153] Figure 8 The illustration depicts a non-contiguous allocation of resources within the time domain 800 of a configured resource pool. Within the time domain 800 of the resource pool, the time-axis resource allocation unit (resource granularity) can be a time slot. Specifically, a time slot comprising 14 OFDM symbols can be the basic unit of time-axis resource allocation. Referring to the time domain 800 of the configured resource pool, shaded time slots represent time slots allocated to the resource pool along the time axis, and the allocation of time slots along the time axis to the resource pool can be indicated using system information. For example, time-domain resource pool configuration information within the SIB can be used to indicate time slots allocated to the resource pool along the time axis. Specifically, at least one time slot configured as a time-domain resource pool can be indicated using a bitmap. (Refer to...) Figure 8 Physical time slot 800, belonging to a non-contiguous resource pool along the time axis, can be mapped to logical time slot 825. Typically, a set of time slots belonging to a resource pool used for Physical Side Link Shared Channel (PSSCH) can be represented as (t0, t1, ..., ti, ..., tTmax).

[0154] Figure 8 This illustrates the case of continuous resource allocation within the frequency domain 805 of a configured resource pool. Within the frequency domain 805 of the resource pool, the unit of resource allocation along the frequency axis can be a sub-channel 810. Specifically, a sub-channel 810 configured by one or more resource blocks (RBs) can be defined as the basic unit of frequency domain resource allocation. That is, a sub-channel 810 can be defined as an integer multiple of the number of RBs. (See reference...) Figure 8The subchannel size (sizeSubchannel) can be configured by five consecutive PRBs, but this disclosure is not limited to this, and the subchannel size can be configured differently. Furthermore, although a subchannel is typically configured by consecutive PRBs, subchannels are not necessarily configured by consecutive PRBs. Subchannel 810 can be the basic unit for resource allocation for PSSCH. Additionally, subchannels related to the Physical Side Link Feedback Channel (PSFCH) can be defined independently of the PSSCH.

[0155] refer to Figure 8 The starting position of a subchannel in the frequency domain within the resource pool can be indicated by startRB-Subchannel 815. When the resource allocation unit along the frequency axis is subchannel 810, frequency domain resource pool configuration can be performed using configuration information regarding the subchannel's starting RB index (startRB-Subchannel 815), information indicating how many RBs constitute the subchannel (sizeSubchannel 810), and the total number of subchannels (numSubchannel). Furthermore, frequency domain resource pool configuration can also be performed using configuration information regarding the subchannel's ending RB index (EndRB-Subchannel) 820. According to various embodiments, subchannels allocated to the resource pool in the frequency domain can be indicated using system information. For example, at least one of startRB-Subchannel, sizeSubchannel, EndRB-Subchannel, and numSubchannel can be indicated as frequency resource pool configuration information in the SIB. When subchannels are defined for the PSFCH independently of the PSSCH, the subchannel configuration information for the PSFCH and PSSCH can be indicated to the UE separately.

[0156] Figure 9 An example of a signal flow for allocating sidelink transmission resources in a wireless communication system according to an embodiment of the present disclosure is illustrated. Figure 9 The diagram illustrates the signal exchange between the transmitting UE 901, the receiving UE 902, and the base station 903.

[0157] As described below, the scheme by which the base station allocates transmission resources for sidelink communication can be referred to as Mode 1. Mode 1 is a scheme based on the base station's scheduling of resource allocation. More specifically, in Mode 1 resource allocation, the base station can allocate resources for sidelink transmission to UEs with RRC connections according to a dedicated scheduling scheme. Since the base station can manage the resources used for sidelink transmission, the scheduled resource allocation can be advantageous for interference management and resource pool management (e.g., dynamic allocation and / or configuration authorization (CG)).

[0158] refer to Figure 9 In operation 907, the transmitting UE 901, camped on cell (905), can receive a sidelink SIB from base station 903. In operation 909, the receiving UE 902 can monitor sidelink communication based on the sidelink SIB or RRC message received from base station (e.g., 903) or an Rx resource pool included in a pre-configuration. As used herein, receiving UE 902 refers to a UE that receives data transmitted by transmitting UE 901. The sidelink SIB can be transmitted periodically or on demand. Additionally, the sidelink SIB may include at least one of the following: sidelink resource pool information for sidelink communication, parameter configuration information for sensing operations, information for configuring sidelink synchronization, or carrier information for sidelink communication operating at different frequencies. Although operations 907 and 909 have been described above as being performed sequentially, this is for illustrative purposes, and operations 907 and 909 can be performed in parallel.

[0159] In operation 913, if a data service for sidelink communication is generated in the transmitting UE 901, the transmitting UE 901 can initiate an RRC connection procedure with the base station 903 to request (915) transmission resources. The RRC connection between the transmitting UE 901 and the base station 903 can be referred to as Uu-RRC. The Uu-RRC connection can be performed before the UE 901 generates the data service. In addition, in mode 1, when a Uu-RRC connection is established between the base station 903 and the receiving UE 902, the transmitting UE 901 performs transmission to the receiving UE 902 via the sidelink. In addition, in mode 1, even if a Uu-RRC connection is not established between the base station 903 and the receiving UE 902, the transmitting UE 901 can still perform transmission to the receiving UE 902 via the sidelink.

[0160] In operation 915, the transmitting UE 901 may request the base station 903 to provide transmission resources for transmitting sidelink data to the receiving UE 902. The transmitting UE 901 may send the request for sidelink transmission resources to the base station 903 using at least one of the Physical Uplink Control Channel (PUCCH), RRC messages, or MACCE. For example, when using MAC CE, the MAC CE may be a Buffer Status Report (BSR) related MAC CE with a new format, which includes at least one of an indicator for a buffer status report used for sidelink communication and information about the size of data stored in a buffer for device-to-device (D2D) communication (or V2X communication). This MAC CE may be referred to as a sidelink BSR MAC CE. Alternatively, when using PUCCH, the transmitting UE 901 may request sidelink resources via bits of a scheduling request (SR) sent via PUCCH. Additionally, when using RRC, UE 901 can send information about receiving UE 902 and frequencies for sending and receiving various types of sidelink communication (including sidelink discovery, sidelink data communication, and sidelink relay communication) to the base station via Uu-RRC, and can include at least one of the following information via the same or different RRC messages.

[0161] The frequency to be used for receiving in sidelink communication

[0162] Frequency to be used for transmission in sidelink communication

[0163] Types of sidelink data sent in sidelink communication

[0164] Periodicity and magnitude of sidelink data occurring in sidelink communication

[0165] Information about the target UE (target UE ID, UE capabilities, DRX information, etc.) received in sidechain communication from sidechain data sent in the sidechain communication.

[0166] QoS information of sidelink data sent in sidelink communication

[0167] The type of sidelink data broadcast in sidelink communication

[0168] RLC mode for sidelink data sent in sidelink communication

[0169] In operation 915, PUCCH, MAC CE, and RRC messages can be used independently of each other or in combination depending on the purpose. Furthermore, operation 915 is described after operation 913, but this is for ease of description. It can also be used in the unicast layer 2 link establishment process 911, which establishes a PC5 unicast link with receiving UE 902, to request resources for sending sidechain data to be sent by UE 901, and can be executed in parallel or simultaneously with other operations.

[0170] In operation 917, base station 903 may send an RRC message to transmitting UE 901, which includes information about the transmission resources to be used by transmitting UE 901.

[0171] In Operation 919, base station 903 can send downlink control information (DCI) to sending UE 901 via PDCCH.

[0172] By operating procedures 917 to 919, base station 903 can instruct transmitting UE 901 to schedule sidelink communication with receiving UE 902. More specifically, base station 903 can allocate sidelink transmission resources to transmitting UE 901 according to at least one of a Dynamic Grant (DG) scheme or a Configuration Grant (CG) scheme.

[0173] In the case of a dynamic granting (DG) scheme, base station 903 can allocate resources for transmission of at least one transport block (TB) by sending a DCI 919 to transmitting UE 901. The sidelink scheduling information included in the DCI may include resource pool information, parameters related to the initial transmission timing and / or retransmission timing, and parameters related to the frequency allocation location information field. The DCI regarding the dynamic granting scheme can be scrambled with Cyclic Redundancy Check (CRC) based on the Sidelink Radio Network Temporary Identifier (SL-RNTI) to indicate that the transmission resource allocation scheme is a dynamic granting scheme.

[0174] In the case of a configured grant scheme (CG), base station 903 can periodically allocate resources for transmitting at least TB via RRC message 917, or the periodicity of the sidelink CG can be configured. Additionally, base station 903 can send a DCI to transmitting UE 901 to activate and / or deactivate an existing CG or indicate a retransmission. The sidelink scheduling information included in the DCI may include parameters related to the initial transmission timing and / or the retransmission timing, as well as parameters related to the frequency allocation location information field. In the case of a configured grant scheme, the initial transmission timing and / or the retransmission timing, as well as the frequency allocation location, can be determined based on the sent DCI, and resources can be repeated within the CG periodic intervals. The DCI regarding the configured grant scheme can be CRC scrambled based on the sidelink configured Scheduling Radio Network Temporary Identifier (SL-CS-RNTI) to indicate that the transmission resource allocation scheme is a configured grant scheme. Furthermore, the configured grant scheme can be classified as Type 1 CG and Type 2 CG.

[0175] In the case of broadcast transmission between transmitting / receiving UEs 901 and 902, in operations 921 and 923, transmitting UE 901 can broadcast SCI and data to at least one receiving UE (e.g., 902) via PSCCH and PSSCH without a PC5 unicast link connection.

[0176] In the case of unicast or multicast transmission between transmitting / receiving UEs 901 and 902, transmitting UE 901 can perform a unicast Layer 2 link establishment procedure 911 in operation 911 to communicate directly with other UEs (e.g., receiving UE 902). The upper layer (e.g., ProSe or V2X layer) of transmitting / receiving UEs 901 and 902 can provide a PC5 link ID and / or a source Layer 2 ID and a destination Layer 2 ID, enabling the AS layer of transmitting / receiving UEs 901 and 902 to identify the PC5 unicast link. The RRC connection between UEs 901 and 902 can be used for unicast communication and is a logical RRC connection corresponding to a pair of source Layer 2 IDs and destination Layer 2 IDs. This RRC connection between UEs 901 and 902 can be referred to as PC5-RRC to distinguish it from Uu-RRC. In the case of a multicast transmission scheme, a PC5-RRC connection can be configured separately between the transmitting and receiving UEs within the group. (Reference) Figure 9The unicast layer 2 link establishment procedure 911 is shown as an operation after the side link SIB is received 907, but the unicast layer 2 link establishment procedure 911 can be performed before receiving the side link SIB, or it can be omitted if PC5-RRC broadcast or multicast transmission is not required. If a PC5-RRC connection is required, the unicast layer 2 link establishment procedure 911 can be performed. In operation 921, the transmitting UE 901 can send a 1-operation SCI to the receiving UE 902 via PSCCH. Additionally, in operation 921, the transmitting UE 901 can send a 2-operation SCI and side link data to the receiving UE 902 via PSSCH. In mode 1, the transmitting UE 901 can identify the side link scheduling information included in the DCI received from the base station 903, and can perform side link scheduling based on the side link scheduling information. The SCI can be divided into a first-stage SCI sent via PSCCH and a second-stage SCI sent via PSSCH, and the first-stage SCI can include at least one of the following information.

[0177] Priority

[0178] Frequency resource allocation

[0179] Time resource allocation

[0180] Resource reservation period

[0181] Demodulation Reference Signal (DMRS) mode

[0182] Second-stage SCI format

[0183] Beta_offset indicator

[0184] Number of DMRS ports

[0185] Modulation and coding schemes

[0186] Additional MCS table indicator

[0187] PSFCH Overhead Indication

[0188] reserve

[0189] Conflict Information Receiver Flag

[0190] Priority can be sent or configured from the upper layer and can be specified by using 3 bits, with a maximum value of 8, such that, for example, priority value 1 corresponds to 000 and 2 corresponds to 001. In the case of sidelink data, this value can have the highest priority among all logical channels or MAC CEs included in the TB scheduled by the SCI. When sending MAC CEs or SCIs for inter-UE coordination, this value can be configured by RRC parameters and differ from the priority of the corresponding MAC CE. Without RRC parameter configuration, the inter-UE coordination request MAC CE can have the highest priority among all logical channels or MAC CEs included in the TB of the UE receiving the corresponding MAC CE, and the inter-UE coordination information MAC CE sent by the UE in response to the request can have the same value as the priority field in the inter-UE coordination request MAC CE after receiving the request. Additionally, when the inter-UE coordination information MAC CE is sent not by a request from another UE but by specific conditions (e.g., when the RSRP of a resource reserved by a third UE is higher than a specific value), the UE can arbitrarily select a priority from values ​​between 1 and 8.

[0191] When selecting resources for multiple TBs (i.e., multiple MAC Protocol Data Units (PDUs)), the reserved interval can indicate a fixed value for the interval between TBs. When selecting resources for a single TB, "0" can be used to indicate the value for the interval between TBs.

[0192] The second-stage SCI may be included in the PSSCH resource indicated by the first-stage SCI sent in operation 921, and may be sent along with the data in operation 923. The second-stage SCI may include at least one of the following information.

[0193] HARQ process number

[0194] New data indicator

[0195] Redundant version

[0196] Source ID

[0197] Destination ID

[0198] HARQ Feedback Enable / Disable Indicator

[0199] Projection type indicator

[0200] CSI Request

[0201] Region ID

[0202] Communication range requirements

[0203] Provide / Request Indicator

[0204] Resource combination

[0205] First resource location

[0206] Reference time slot position

[0207] Resource set type

[0208] Lowest Subchannel Index

[0209] Priority

[0210] Number of sub-channels

[0211] Resource reservation period

[0212] Resource selection window location

[0213] Resource set type

[0214] Fill bits

[0215] Furthermore, in operation 925, the receiving UE 902 can send a first HARQ feedback message to the transmitting UE 901, indicating whether the demodulation / decoding of the received data via operations 921 and 923 was successful. The first HARQ feedback message includes information such as ACK (success) or NACK (failure), and the receiving UE 902 sends the first HARQ feedback message to the transmitting UE 901 via the PSFCH channel. In operation 927, based on the first HARQ feedback message received from the receiving UE 902, the transmitting UE 901 sends the transmission result as a second HARQ feedback message to the base station 903. The second HARQ feedback is sent to the base station via the PUCCH. The second HARQ feedback message may be the same as or different from the first HARQ feedback message. Additionally, the second HARQ feedback message may include multiple first HARQ feedback messages. These multiple first HARQ feedback messages may include multiple HARQ feedback messages received from a single receiving UE, or one or more HARQ feedback messages received from multiple UEs. Based on the second HARQ feedback information, the base station can allocate resources for retransmission to the sending UE 901, or allocate resources for new transmissions to the sending UE 901, or stop allocating resources to the sending UE 901 if there are no more resources to allocate. PUCCH transmission resources can be determined by the DCI information sent by the base station to the sending UE via PDCCH. PSFCH (925) transmission resources can be determined by the SCI of the PSCCH or by the transmission resource areas within which PSSCH has already been transmitted / received.

[0216] Figure 10 Another example of a signal flow for allocating sidelink transmission resources in a wireless communication system, according to embodiments of the present disclosure, is shown. Figure 10 The signal exchange between the transmitting UE 1001, the receiving UE 1002, and the base station 1003 is shown.

[0217] As described below, the scheme in which the UE directly allocates transmission resources for the sidelink through sensing in the sidelink can be referred to as Mode 2. Mode 2 can also be referred to as UE autonomous resource selection. Specifically, according to Mode 2, base station 1003 can provide the UE with a sidelink transmit / receive resource pool for the sidelink through sidelink SIB or RRC messages (e.g., RRCReconfiguration message or PC5 RRC message), and the transmitting UE 1001 can select the resource pool and resources according to predetermined rules. Figure 9 Unlike Mode 1, which describes base stations directly participating in resource allocation, in... Figure 10 In Mode 2 as described, the transmitting UE 1001 can autonomously select resources and transmit data based on resource pools previously received via sidelink SIB, RRC messages, or pre-configured resources.

[0218] refer to Figure 10 In operation 1007, the currently camped (1005) transmitting UE 1001 can receive a sidelink SIB from base station 1003. In operation 1009, the receiving UE 1002 can monitor sidelink communication based on a sidelink SIB or RRC message received from the base station (e.g., 1003) or an Rx resource pool included in a pre-configured configuration. As used herein, receiving UE 1002 refers to the UE that receives data transmitted by transmitting UE 1001. Sidelink SIBs can be transmitted periodically or on demand. Additionally, the sidelink SIB may include at least one of the following: sidelink resource pool information for sidelink communication, parameter configuration information for sensing operations, information for configuring sidelink synchronization, or carrier information for sidelink communication operating at different frequencies. Although operations 1007 and 1009 have been described sequentially above, this is for ease of description, and operations 1007 and 1009 can be performed in parallel. Figure 9 In this case, base station 1003 and transmitting UE 1001 operate in RRC connection state, while Figure 10 In operation 1013, base station 1003 and transmitting UE 1001 can operate regardless of whether an RRC connection exists between them. That is, when transmitting UE 1001 is an IC (Integrated Circuit), it can perform mode 2-based sidelink communication in RRC-connected state, in idle or inactive state without RRC connection, or even in OOC (Out of Context) state. Furthermore, even in RRC-connected state, base station 1003 can avoid directly participating in resource allocation and can configure transmitting UE 1001 to autonomously select transmission resources.

[0219] In operation 1013, if data traffic for sidelink communication is generated in transmitting UE 1001, transmitting UE 1001 can initiate an RRC connection procedure with base station 1003 to request (1015) transmission resources. The RRC connection between transmitting UE 1001 and base station 1003 can be referred to as Uu-RRC. The Uu-RRC connection can be performed before transmitting UE 1001 generates data traffic.

[0220] In operation 1015, transmitting UE 1001 can use an RRC message to request transmission resources from base station 1003 for transmitting sidelink data to receiving UE 1002. Transmitting UE 1001 can send information about receiving UE 1002 and frequencies for various types of sidelink communication transmission and reception (including sidelink discovery, sidelink data communication, and sidelink relay communication) to the base station via Uu-RRC, and it can do so through the same or different RRC messages including... Figure 9At least one of the above examples of information.

[0221] In operation 1017, base station 1003 can configure a resource pool for transmitting UE 1001 based on the transmission resources requested by transmitting UE 1001.

[0222] In operation 1019, the transmitting UE 1001 can directly select time-domain and frequency-domain resources via side-link SIB 1007 or RRC message 1017 from base station 1003, or sense them in a pre-configured transmission resource pool.

[0223] In the case of broadcast transmission between sending / receiving UEs 1001 and 1002, in operations 1021 and 1023, sending UE 1001 can broadcast SCI and data to at least one receiving UE (e.g., 1002) via PSCCH and PSSCH without a PC5 unicast link connection.

[0224] In the case of unicast or multicast transmission between transmitting / receiving UEs 1001 and 1002, transmitting UE 1001 can perform a unicast Layer 2 link establishment procedure 1011 in operation 1011 to communicate directly with other UEs (e.g., receiving UE 1002). The upper layer (e.g., ProSe or V2X layer) of transmitting / receiving UEs 1001 and 1002 can provide a PC5 link ID and / or a source Layer 2 ID and a destination Layer 2 ID, so that the AS layer of transmitting / receiving UEs 1001 and 1002 can identify the PC5 unicast link. The RRC connection between UEs 1001 and 1002 can be used for unicast communication and is a logical RRC connection corresponding to a pair of source Layer 2 IDs and destination Layer 2 IDs. This RRC connection between UEs 1001 and 1002 can be referred to as PC5-RRC to distinguish it from Uu-RRC. In the case of multicast transmission schemes, PC5-RRC connections can be configured separately between transmitting and receiving UEs within the group. refer to Figure 10The unicast layer 2 link establishment procedure 1011 is shown as an operation after the side link SIB is received 1007. However, the unicast layer 2 link establishment procedure 1011 can be performed before receiving the side link SIB, or it can be omitted if PC5-RRC broadcast or multicast transmission is not required. If a PC5-RRC connection is required, the unicast layer 2 link establishment procedure 1011 can be performed. In operation 921, the transmitting UE 1001 can send a 1-operation SCI to the receiving UE 1002 via PSCCH. Additionally, in operation 1021, the transmitting UE 1001 can send a 2-operation SCI and side link data to the receiving UE 1002 via PSSCH. In mode 1, the transmitting UE 901 can identify the side link scheduling information included in the DCI received from the base station 903 and can perform side link scheduling based on the side link scheduling information. In mode 2, the transmitting UE 1001 can directly perform side link scheduling by performing sensing and transmission resource selection operations. The first-stage SCI and the second-stage SCI used in operations 1021 and 1023 can be compared with... Figure 9 The same as in the example.

[0225] Furthermore, in operation 1025, receiving UE 1002 may send HARQ feedback information to transmitting UE 1001 indicating whether the modulation / decoding of the data received in operations 1021 and 1023 was successful. The HARQ feedback information includes ACK (success) or NACK (failure) information, and receiving UE 1002 sends the HARQ feedback information to transmitting UE 1001 via the PSFCH channel.

[0226] In addition, although not in Figure 9 or Figure 10 As shown, however, if any transmitting UE (e.g., 1001) performs sidelink communication under OOC, mode 2 resource allocation can be used, and as available information for sidelink communication, information can be used by pre-configuring stored in the UE, or configuration information can be received from the base station via a sidelink relay.

[0227] Figure 11 An example of a channel structure for a time slot used for sidelink communication in a wireless communication system according to an embodiment of the present disclosure is illustrated. Figure 11 The diagram illustrates the physical channels mapped to time slots used for sidelink communication.

[0228] refer to Figure 11Automatic gain control (AGC) symbol 1105, which can be used to receive the UE, is mapped to the first symbol of time slot 1100. Thereafter, PSCCH 1110, PSSCH 1115, GUARD 1120, AGC 1125 for PSFCH, PSFCH 1130, and GUARD 1135 can be mapped in sequence.

[0229] Before transmitting the PSCCH in the corresponding time slot 1100, the transmitting UE may transmit a signal for AGC purposes in one or more symbols having the same information as the symbol transmitting PSCCH 1110. AGC symbol 1105 can be used to allow the receiving UE to appropriately perform automatic gain control (AGC) to adjust the amplification strength when amplifying the power of the received signal. The signal used for AGC may be referred to as a "synchronization signal," "sidelink synchronization signal," "sidelink reference signal," "intermediate code," "initial signal," "wake-up signal," or another term with equivalent technical meaning.

[0230] PSCCH 1110, which includes control information, can be transmitted using symbols sent at the beginning of a time slot. PSSCH 1115, scheduled by the control information from PSCCH 1110, can then be transmitted. PSSCH 1115 may have at least a portion of the SCI (control information) mapped to it. Subsequently, GUARD 1120 and AGC 1125 may be present for PSFCH, and a physical channel (i.e., PSFCH 1130) may be mapped for transmitting feedback information.

[0231] exist Figure 11 In the example shown, PSFCH 1130 is located in the penultimate symbol of the time slot. By ensuring GUARD 1120 (a predetermined empty time period) between PSSCH 1115 and PSFCH 1130, a UE that has already sent or received PSSCH 1115 can prepare to send or receive PSFCH 1130 (e.g., transmit / receive handover). Additionally, AGC 1125 may exist for PSFCH 1130. Following PSFCH 1130, GUARD 1135 (a predetermined empty time period) exists.

[0232] A UE may have a location for a pre-configured PSFCH transmission slot. As used herein, pre-configuration can refer to the process of determining a pre-configuration during UE manufacturing, transmitting a pre-configuration when accessing a link-related system, transmitting a pre-configuration from a base station when accessing a base station, or transmitting a pre-configuration from another UE.

[0233] exist Figure 11In one embodiment, the preamble signal for performing AGC has been described as being transmitted separately within the physical channel structure in the side link time slot. However, according to another embodiment, a separate preamble signal may not be transmitted, and the receiver of the receiving UE may perform AGC operations by using the physical channel for control information or data transmission while simultaneously receiving the physical channel for control information or data transmission.

[0234] Figure 12a This is a diagram illustrating the user plane radio protocol structure for multipath UE-network relay according to an embodiment of the present disclosure.

[0235] refer to Figure 12a The first UE 1210 has a PC5 unicast link established / formed to send / receive data to / from the second UE 1220, and the second UE 1220 has a Uu link established / formed to send / receive data to / from the base station 1230. The second UE 1220 can relay data sent by the first UE 1210 to the base station 1230, and the second UE 1220 can relay data sent by the base station 1230 to the first UE 1210. Data transmission / reception between the first UE 1210 and the base station 1230 via the second UE 1220 can be referred to as U2N relay, and in this disclosure may be referred to as an indirect path to clearly indicate that it is not a direct communication link with the base station 1230. Additionally, the first UE 1210 has a Uu link established for sending / receiving data to / from the base station 1230, and the first UE 1210 can send / receive DL or UL data to / from the base station 1230. In this disclosure, data transmission / reception between the first UE 1210 and the base station 1230 may be referred to as a direct path to clearly indicate that it is not data transmission / reception via an indirect path or relay. The second UE 1220, configured with an indirect path from the first UE 1210 to the base station 1230 via the second UE 1220, may be referred to as a serving relay, and the base station 1230, configured with a direct path from the first UE 1210 to the base station 1230, may be referred to as a serving gNB, or the cell of the base station may be referred to as a serving cell.

[0236] The first UE 1210 can send data to / receive data from the base station 1230 via a U2N relay and can be referred to as a U2N remote UE. The second UE 1220 can perform data transmission / reception via a U2N relay between the first UE 1210 and the base station 1230 and can be referred to as a U2N relay UE.

[0237] To transmit / receive user data via direct and indirect paths, the user plane radio protocols of the first UE 1210, the second UE 1220, and the base station 1230 may include Uu-SDAP 1211-1 and 1231-1, Uu-PDCP 1212 and 1232, PC5-SRAP 1213 and 1221, Uu-SRAP 1225 and 1233, PC5-RLC 1214 and 1222, Uu-RLC 1217, 1226, 1234 and 1237, PC5-MAC 1215 and 1223, Uu-MAC 1218, 1227, 1235 and 1238, PC5-PHY 1216 and 1224, and Uu-PHY 1219, 1228, 1236 and 1239.

[0238] The main functions of Uu-SDAP 1211-1 or 1231-1 may include some of the following functions. However, the functions described below are not limiting.

[0239] - Mapping between PC5 QoS streams and SL-DRB for NR sidelink communication

[0240] - Mark the PC5 QoS flow ID in the unicast of NR sidelink communication packets.

[0241] The main functions of Uu-PDCP 1212 or 1232 may include some of the following functions. However, the functions described below are not limiting.

[0242] - Data transmission (user plane or control plane)

[0243] - PDCP SN maintenance

[0244] - Header compression and decompression using the ROHC protocol

[0245] -Header compression and decompression using the EHC protocol

[0246] - Uplink PDCP SDU compression and decompression: UDC based solely on DEFLATE

[0247] - Encryption and decryption

[0248] - Integrity protection and integrity verification

[0249] - SDU discarding based on timer

[0250] - For split bearers, routing

[0251] -copy

[0252] - Reordering and sequential delivery

[0253] -unordered delivery

[0254] -Duplicate discarding

[0255] The main functions of PC5-SRAP 1213 or 1221 may include some of the following functions. However, the functions described below are not limiting.

[0256] -Data transmission

[0257] - Determine the UE ID field and bearer ID field used for data packetization

[0258] - Determining the export link

[0259] - Determination of the exit RLC channel

[0260] The main functions of PC5-RLC 1214 or 1222 and Uu-RLC 1217, 1226, 1234 or 1237 may include some of the following functions. However, the functions described below are not limiting.

[0261] -Transmission of upper-layer PDUs

[0262] - Sequence numbers (UM and AM) independent of sequence numbers in PDCP

[0263] - Error correction via ARQ (AM only)

[0264] - Segmentation (AM and UM) and resegmentation (AM only) of RLC SDU

[0265] - SDU (AM and UM) Reorganization

[0266] -Duplicate detection (AM only)

[0267] -RLC SDU discard (AM and UM)

[0268] -RLC Reconstruction

[0269] - Protocol error detection (AM only)

[0270] The main features of PC5-MAC 1215 or 1223 and Uu-MAC 1218, 1227, 1235 or 1238 may include some of the following features. However, the features described below are not limiting.

[0271] Mapping between logical channels and transport channels

[0272] - Multiplex MAC SDUs from one or more logical channels onto a transport block (TB) to be sent to the physical layer on the transport channel.

[0273] - Demultiplex the MAC SDU from the physical layer of the transport channel into one or different logical channels.

[0274] - Scheduling Information Report

[0275] - Error correction via HARQ

[0276] -Logical channel prioritization

[0277] Priority handling between overlapping resources of a UE

[0278] - Radio Resource Selection

[0279] PC5-PHY layer 1216 or 1224 and Uu-PHY layer 1219, 1228, 1236 or 1239 can perform channel coding and modulation of upper-layer data to generate OFDM symbols, and can convert OFDM symbols into RF signals, which are then transmitted through an antenna. Additionally, the PHY layer can perform demodulation and channel decoding on the received OFDM symbols before transmitting them to the upper layer.

[0280] Figure 12b This is a diagram illustrating the control plane radio protocol structure of a multi-hop UE-network relay according to an embodiment of the present disclosure.

[0281] refer to Figure 12bThe first UE 1210 has a PC5 unicast link established / formed to send data to / receive data from the second UE 1220, and the second UE 1220 has a Uu link established / formed to send data to / receive data from the base station 1230. The second UE 1220 can relay data sent by the first UE 1210 to the base station 1230, and the second UE 1220 can relay data sent by the base station 1230 to the first UE 1210. The data transmission / reception between the first UE 1210 and the base station 1230 via the second UE 1220 can be referred to as U2N relay, and in this disclosure it can be referred to as an indirect path to clearly indicate that it is not a direct communication link with the base station 1230. Additionally, the first UE 1210 has an established / formed Uu link to send data to / receive data from the base station 1230, and the first UE 1210 can send DL or UL data to / receive DL or UL data from the base station 1230. In this disclosure, the data transmission / reception between the first UE 1210 and the base station 1230 can be referred to as a direct path to clearly indicate that it is not a data transmission / reception via an indirect path or relay. The second UE 1220, configured with an indirect path from the first UE 1210 to the base station 1230 via the second UE 1220, can be referred to as a serving relay, and the base station 1230, configured with a direct path from the first UE 1210 to the base station 1230, can be referred to as a serving gNB, or the cell of the base station can be referred to as a serving cell.

[0282] To transmit / receive control data via direct and indirect paths, the control plane radio protocols of the first UE 1210, the second UE 1220, and the base station 1230 may include Uu-RRC 1211-2 and 1231-2, Uu-PDCP 1212 and 1232, PC5-SRAP 1213 and 1221, Uu-SRAP 1225 and 1233, PC5-RLC 1214 and 1222, Uu-RLC 1217, 1226, 1234 and 1237, PC5-MAC 1215 and 1223, Uu-MAC 1218, 1227, 1235 and 1238, PC5-PHY 1216 and 1224, and Uu-PHY 1219, 1228, 1236 and 1239.

[0283] The main functions of Uu-RRC 1311-2 or 1331-2 may include some of the following functions. However, the functions described below are not limiting.

[0284] - Broadcast of system information related to AS and NAS

[0285] - Paging initiated by 5GC or NG-RAN

[0286] - The establishment, maintenance, and release of RRC connections between the UE and NG-RAN, including: the addition, modification, and release of carrier aggregation; the addition, modification, and release of dual connections in NR or between E-UTRA and NR.

[0287] -Includes security features for key management

[0288] - Establishment, configuration, maintenance, and release of signaling radio bearers (SRBs) and data radio bearers (DRBs)

[0289] - Mobility functions, including: handover and context transfer; UE cell selection and reselection and control of cell selection and reselection; inter-RAT mobility.

[0290] -QoS management function

[0291] - UE measurement reports and control of reports

[0292] - Detection and recovery of radio link failures

[0293] - NAS message transmission from UE to NAS / from NAS to UE

[0294] Figure 12c This is a diagram illustrating a user plane radio protocol structure for multipath UE-network relay without 3GPP access in UE-to-UE communication according to an embodiment of the present disclosure.

[0295] refer to Figure 12cThe first UE 1210 has established / formed non-3GPP links 1240 and 1250 to send / receive data to / from the second UE 1220, and the second UE 1220 has established / formed a U2N link to send / receive data to / from the base station 1230. The second UE 1220 can relay data sent by the first UE 1210 to the base station 1230, and the second UE 1220 can relay data sent by the base station 1230 to the first UE 1210. The data transmission / reception between the first UE 1210 and the base station 1230 via the second UE 1220 can be referred to as U2N relay, and in this disclosure it can be referred to as an indirect path to clearly indicate that it is not a direct communication link with the base station 1230. Additionally, the first UE 1210 has an established / formed Uu link to send / receive data to / from the base station 1230, and the first UE 1210 can send / receive DL or UL data to / from the base station 1230. In this disclosure, the data transmission / reception between the first UE 1210 and the base station 1230 can be referred to as a direct path to clearly indicate that it is not a data transmission / reception via an indirect path or relay. The second UE 1220, configured with an indirect path from the first UE 1210 to the base station 1230 via the second UE 1220, can be referred to as a serving relay, and the base station 1230, configured with a direct path from the first UE 1210 to the base station 1230, can be referred to as a serving gNB, or the cell of the base station can be referred to as a serving cell. Non-3GPP links 1240 and 1250 can be communication methods between UEs, which may include Wi-Fi or Bluetooth, and do not use V2X, ProSe, or RAT side links that use technologies defined in 3GPP (e.g., LTE / NR).

[0296] To transmit / receive control data via direct and indirect paths, the user plane radio protocols of the first UE 1210, the second UE 1220, and the base station 1230 may include Uu-SDAP 1211-1 and 1231-1, Uu-PDCP 1212 and 1232, Uu-RLC 1217, 1226, 1234 and 1237, Uu-MAC 1218, 1227, 1235 and 1238, and Uu-PHSY 1219, 1228, 1236 and 1239. The connection of non-3GPP links 1240 and 1250 between the first UE 1210 and the second UE 1220 can be configured using methods not defined by 3GPP (e.g., methods for always connecting the first UE 1210 and the second UE 1220), or can be established using methods not defined by 3GPP.

[0297] Figure 12dThis is a diagram illustrating a user plane radio protocol structure for multipath UE-network relay without 3GPP access in UE-to-UE communication according to an embodiment of the present disclosure.

[0298] refer to Figure 12d The first UE 1210 has established / formed non-3GPP links 1240 and 1250 to send / receive data to / from the second UE 1220, and the second UE 1220 has established / formed a U2N link to send / receive data to / from the base station 1230. The second UE 1220 can relay data sent by the first UE 1210 to the base station 1230, and the second UE 1220 can relay data sent by the base station 1230 to the first UE 1210. The data transmission / reception between the first UE 1210 and the base station 1230 via the second UE 1220 can be referred to as U2N relay, and in this disclosure it can be referred to as an indirect path to clearly indicate that it is not a direct communication link with the base station 1230. Additionally, the first UE 1210 has an established / formed Uu link to send data to / receive data from the base station 1230, and the first UE 1210 can send DL or UL data to / receive DL or UL data from the base station 1230. In this disclosure, data transmission / reception between the first UE 1210 and the base station 1230 can be referred to as a direct path to clearly indicate that it is not data transmission / reception via an indirect path or relay. The second UE 1220 configured with an indirect path from the first UE 1210 can be referred to as a serving relay, and the base station 1230 configured with a direct path from the first UE 1210 can be referred to as a serving gNB, or the cell of the base station can be referred to as a serving cell. Non-3GPP links 1240 and 1250 can be communication methods between UEs, which may include Wi-Fi or Bluetooth, and are side links of RATs that do not use V2X, ProSe, or technologies defined in 3GPP (e.g., LTE / NR).

[0299] To transmit / receive control data via direct and indirect paths, the user plane radio protocols of the first UE 1210, the second UE 1220, and the base station 1230 may include Uu-RRC 1211-2 and 1231-2, Uu-PDCP 1212 and 1232, Uu-RLC 1217, 1226, 1234 and 1237, Uu-MAC 1218, 1227, 1235 and 1238, and Uu-PHY 1219, 1228, 1236 and 1239. The connection of non-3GPP links 1240 and 1250 between the first UE 1210 and the second UE 1220 can be configured using methods not defined by 3GPP (e.g., methods for always connecting the first UE 1210 and the second UE 1220), or can be established using methods not defined by 3GPP.

[0300] Figure 13a This is a diagram of a signal flow for sending threshold conditions for multipath UE network relay to a relay UE according to an embodiment of the present disclosure.

[0301] refer to Figure 13a The first UE 1310 can be located within the coverage area (Coverage Area (IC)) of the base station 1320 and can support multipath relay.

[0302] Base station 1320 may indicate whether relay is supported in an SIB message (e.g., SIB12), and if the SIB message includes an indicator indicating relay support, the first UE 1310 may recognize information indicating that base station 1320 supports relay. Information regarding whether base station 1320 supports relay may include L2 U2N relay, non-relay discovery, and L3 U2N relay discovery, and information regarding whether multipath (MP) relay is supported may be sent in a true / false format. When MP relay discovery message transmission is required, the first UE 1310, in the RRC_IDLE or RRC_INACTIVE state, may execute procedure 1312 for establishing an RRC connection to base station 1320 that supports L2 U2N relay and / or MP relay.

[0303] Base station 1320 can request capability information from first UE 1310 via RRC message 1313 (e.g., UECapabilityEnquiry) to obtain capability information of first UE 1310 in the RRC_CONNECTED state. First UE 1310 can send an indicator to base station 1320 via RRC message 1314 (e.g., UECapabilityInformation) that includes information indicating support for sidelink relay in 3GPP version 18 or information indicating support for multipath relay. Whether multipath relay or version 18 sidelink relay is supported can differently indicate whether relay or remote UE operation is supported. For example, RRC message 1314 could be capability information indicating that first UE 1310 supports multipath relay and can operate as a relay UE in multipath relay. Through this message (RRC message 1314), base station 1320 can know that first UE 1310 supports multipath relay. Furthermore, although not shown in the figure, the Access and Mobility Management Function (AMF) can receive information from the Unified Data Management (UDM) or Unified Data Repository (UDR) regarding whether L2 and / or L3 UE network relay operations of the first UE 1310 are permitted and whether corresponding operation-specific relay and / or remote UE operations are permitted, and can transmit this information to the base station 1320 via NGAP or the like.

[0304] When the first UE 1310 supports MP relay UE operation and is in the RRC_CONNECTED state where an RRC connection with base station 1320 has been configured, the first UE 1310 may send an RRC message 1315 (e.g., SidelinkUEInformationNR) to base station 1320 to request base station 1320 to provide resources for sending / receiving discovery messages and sharing discovery-related information used in multipath relay. This information may be sent as shown in Table 1 below.

[0305] [Table 1]

[0306]

[0307] The source layer 2 ID used by the first UE 1310 when sending MP relay discovery can be the same as or different from the source layer 2 ID used by the first UE 1310 when sending U2N relay discovery. If the source layer 2 ID used by the first UE 1310 when sending discovery for MP relay differs from the source layer 2 ID used by the first UE 1310 when sending discovery for U2N relay, these two IDs can be distinguished by sl-DiscoveryType or a similar IE, or by a new IE (e.g., sl-SourceIdentityMPRelayUE). Furthermore, to distinguish the purpose of discovery transmission from that of U2N relay, information indicating the transmission of multipath relay discovery (e.g., mp-Relay) can be included in sl-DiscoveryType or a similar IE.

[0308] Upon receiving an RRC message sent by the first UE 1310, the base station 1320 can configure resources and thresholds for the first UE 1310 to send / receive discovery messages for U2N relay and / or MP relay via an RRC message 1316 (e.g., RRCReconfiguration).

[0309] According to embodiments of this disclosure, when the first UE 1310 supports U2N relay UE operation and is in the RRC_CONNECTED state where an RRC connection with base station 1320 is configured, base station 1320 can configure a range of thresholds for the first UE 1310's discovery message sending and / or receiving operations via RRC message 1316 (e.g., RRCReconfiguration). The thresholds can be configured by at least one of threshHighRelay, threshLowRelay, hystMaxRelay, and hystMinRelay (or may include at least one of them).

[0310] According to embodiments of this disclosure, when the first UE 1310 supports U2N relay UE operation and is in an RRC_IDLE or RRC_INACTIVE state without an configured RRC connection with base station 1320, base station 1320 can configure a range of thresholds for the first UE 1310's discovery message sending and / or receiving operations via SIB message 1311 (e.g., SIB12). The thresholds can be configured by at least one of threshHighRelay, threshLowRelay, hystMaxRelay, and hystMinRelay (or may include at least one of them). If the value obtained by measuring the RSRP of the serving cell, primary cell, or camped cell is lower than (or less than) the value obtained by subtracting hystMaxRelay from threshHighRelay, or if the value obtained by measuring the RSRP of the serving cell, primary cell, or camped cell is higher than (or greater than) the value obtained by adding hystMinRelay to threshLowRelay, then the first UE 1310 can determine that the first UE 1310 meets the threshold conditions used to determine whether to operate as a U2N relay UE. When it is determined that the first UE 1310 meets the threshold conditions, the first UE 1310 can operate as a U2N relay UE.

[0311] Additionally, if the RSRP value obtained by measuring the serving cell, primary cell, or camped cell is higher than (greater than) threshLowRelay, or if the RSRP value measured as the serving cell, primary cell, or camped cell is lower than (less than) threshLowRelay, then the first UE 1310 can determine that the first UE 1310 does not meet the threshold conditions used to determine whether the first UE 1310 should operate as a U2N relay UE. When it is determined that the first UE 1310 does not meet the threshold conditions, the first UE 1310 may not operate as a U2N relay UE. Such operation can be illustrated in Table 2 below.

[0312] [Table 2]

[0313]

[0314] The threshold conditions for U2N relays and MP relays can differ. That is, in indirect paths configured with multipath relay UEs having poor Uu link quality, transmission failures and retransmissions may occur frequently, adversely affecting MP relays. Therefore, the lower threshold conditions used to determine whether to operate as a U2N relay UE, which can be configured by threshLowRelay and hystMinRelay, need to be configured differently depending on the channel conditions in multipath relays. Furthermore, the U2N relay service aims to provide extended coverage and stable DL / UL transmissions through relay services even when the U2N remote UE and base station 1320 have poor Uu link quality. Correspondingly, if the U2N relay UE has good coverage with base station 1320 (threshHighRelay or higher), the PC5 connection between the U2N relay UE and a U2N remote UE expected to be far from base station 1320 may be poor. Therefore, in the case of U2N relay, if the U2N relay UE does not meet the threshold conditions, the U2N relay may not send / receive discovery messages.

[0315] Furthermore, if the threshold conditions for U2N relay services and MP relay services are used identically, MP remote UEs may fail to detect MP relay UEs that do not meet the threshold conditions. Additionally, unlike U2N relay, in the case of MP relay, even when the MP remote UE is in a good coverage area near base station 1320, increased stability (reliability) and bandwidth (throughput) can be provided through additional indirect paths. Furthermore, in the case of MP relay, even when both the MP relay UE and the MP remote UE are in a good coverage area near base station 1320, enhanced service can be provided by using MP relay. Therefore, even in good coverage conditions that do not meet the U2N relay UE threshold conditions (i.e., threshHighRelay or higher Uu link quality), it is necessary to provide extended service by allowing the UE to operate as an MP relay UE. In other words, the lower threshold condition (which can be configured by threshLowRelay and hystMinRelay) used to determine whether to operate as a U2N relay UE and the upper threshold condition (which can be configured by threshHighRelay and hystMaxRelay) used to determine whether to operate as a U2N relay UE can be configured and applied differently by the base station 1320 for MP relay UEs, thereby solving the existing operational problems that may occur when the threshold conditions for U2N relay services and the threshold conditions for MP relay services are used in the same way.

[0316] The threshold applicable to MP relay UEs can be used / defined / constructed / configured as different IEs (e.g., threshHighMPRelay, threshLowMPRelay, hystMaxMPRelay, hystMinMPRelay) to clarify that the threshold is used only in MP relays, and can be used / defined / constructed / configured, for example, as shown in Table 3 below.

[0317] [Table 3]

[0318]

[0319] To configure and apply thresholds for MP relay UEs, when the first UE 1310 supports MP relay UE operation and is in the RRC_CONNECTED state with an RRC connection configured to base station 1320, base station 1320 can configure the range of thresholds for the first UE 1310's discovery message sending and / or receiving operations via RRC message 1316 (e.g., RRCReconfiguration). The thresholds may include at least one of threshHighMPRelay, threshLowMPRelay, hystMaxMPRelay, and hystMinMPRelay (or may include at least one of them). When the first UE 1310 supports U2N MP relay UE operation and is in the RRC_IDLE or RRC_INACTIVE state without an RRC connection configured to base station 1320, base station 1320 can configure the range of thresholds for the first UE 1310's discovery message sending and / or receiving operations via SIB message 1311 (e.g., SIB12). The thresholds included in SIB can be configured by at least one of threshHighMPRelay, threshLowMPRelay, hystMaxMPRelay, and hystMinMPRelay (or may include at least one of them).

[0320] Figure 13b This is a flowchart illustrating the process by which a UE determines whether a multipath UE-network relay threshold condition is met according to an embodiment of the present disclosure.

[0321] refer to Figure 13bIf the RSRP obtained by measuring the serving cell, primary cell, or camped cell is lower than (less than) the value obtained by subtracting hystMaxMPRelay from threshHighMPRelay, and if the RSRP obtained by measuring the serving cell, primary cell, or camped cell is higher than (greater than) the value obtained by adding hystMinMPRelay to threshLowMPRelay, then a UE supporting MP Relay can determine that a threshold condition for determining whether to operate as an MP Relay UE is met. If the threshold condition for determining whether to operate as an MP Relay UE is met, the UE can operate as an MP Relay UE. If threshHighMPRelay or threshLowMPRelay is not configured, a UE supporting MP Relay can determine that the threshHighMPRelay or threshLowMPRelay condition for determining whether to always operate as an MP Relay UE is met.

[0322] If, under the MP relay threshold conditions, the value obtained by measuring the RSRP of the serving cell, primary cell, or camped cell is higher than (or greater than) threshHighMPRelay, or if the value obtained by measuring the RSRP of the serving cell, primary cell, or camped cell is lower than (or less than) threshLowMPRelay, then a UE supporting MP relay can be determined to no longer meet the threshold conditions used to determine whether to operate as an MP relay UE. If the threshold conditions used to determine whether to operate as an MP relay UE are not met, the UE may not operate as an MP relay UE.

[0323] Figure 13c This is a flowchart illustrating the process by which a UE determines whether a threshold condition for multipath UE-network relay is met according to an embodiment of the present disclosure.

[0324] refer to Figure 13cIf the value obtained by measuring the RSRP of the serving cell, primary cell, or camped cell is lower than (or less than) the value obtained by subtracting hystMaxMPRelay from threshHighMPRelay, or if the value obtained by measuring the RSRP of the serving cell, primary cell, or camped cell is higher than (or greater than) the value obtained by adding hystMinMPRelay to threshLowMPRelay, then a UE supporting MP Relay can determine that it meets the threshold conditions used to determine whether to operate as an MP Relay UE. If the threshold conditions used to determine whether to operate as an MP Relay UE are met, the UE can operate as an MP Relay UE. If threshHighMPRelay or threshLowMPRelay is not configured, a UE supporting MP Relay can use threshHighRelay or threshLowRelay used to determine whether to operate as a U2N Relay UE, instead of threshHighMPRelay or threshLowMPRelay, to determine the threshold conditions used to determine whether to operate as an MP Relay UE and whether those threshold conditions are met. Without threshHighMPRelay or threshLowMPRelay configured, a UE supporting MP relay can be certain that it always meets the threshHighRelay or threshLowRelay requirement. However, if, while meeting the MP relay threshold conditions, the value obtained by measuring the RSRP of the serving cell, primary cell, or camped cell is higher than (or greater than) threshHighMPRelay, or if the value obtained by measuring the RSRP of the serving cell, primary cell, or camped cell is lower than (or less than) threshLowMPRelay, then as an MP relay UE, a UE supporting MP relay can be certain that it no longer meets the threshold conditions. Alternatively, without threshHighMPRelay or threshLowMPRelay configured, a UE supporting MP relay can use threshHighRelay or threshLowRelay to determine whether it does not meet the MP relay UE threshold.

[0325] In the absence of MP relay UE threshold conditions (or in the absence of MP relay UE threshold conditions being configured), the base station can indicate to the UE via RRC messages or SIB messages whether the UE meets the threshold by using U2N relay UE threshold conditions.

[0326] Figure 14aThis is a diagram of a signal flow for sending threshold conditions for multipath UE network relay to a remote UE according to an embodiment of the present disclosure.

[0327] refer to Figure 13a The first UE 1410 can be located within the coverage area (Coverage Area (IC)) of the base station 1420 and can support multipath relay.

[0328] Base station 1420 may indicate whether relay is supported in an SIB message (e.g., SIB12), and if the SIB message includes an indicator indicating relay support, the first UE 1410 may recognize information indicating that base station 1420 supports relay. Information regarding whether base station 1420 supports relay may include L2 U2N relay, non-relay discovery, and L3 U2N relay discovery, and information regarding whether MP relay is supported may be sent in a true / false format. When MP relay discovery message transmission is required, the first UE 1410, in the RRC_IDLE or RRC_INACTIVE state, may execute procedure 1412 for establishing an RRC connection to base station 1420 that supports L2U2N relay and / or MP relay.

[0329] Base station 1420 can request capability information from first UE 1410 via RRC message 1413 (e.g., UECapabilityEnquiry) to obtain capability information of first UE 1410 in the RRC_CONNECTED state. First UE 1410 can send an indicator to base station 1420 via RRC message 1414 (e.g., UECapabilityInformation) that includes information indicating support for 3GPP version 18 sidelink relay or information indicating support for multipath relay. Whether multipath relay or version 18 sidelink relay is supported can differently indicate whether relay or remote UE operation is supported. For example, RRC message 1414 could be capability information indicating that first UE 1410 supports multipath relay and can operate as a relay UE in multipath relay. Through this message (RRC message 1414), base station 1420 can know that first UE 1410 supports multipath relay. Furthermore, although not shown in the figure, the Access and Mobility Management Function (AMF) can receive information from the Unified Data Management (UDM) or Unified Data Repository (UDR) regarding whether L2 and / or L3 UE network relay operations of the first UE 1410 are permitted and whether corresponding operation-specific relay and / or remote UE operations are permitted, and can transmit this information to the base station 1420 via NGAP or the like.

[0330] If the first UE 1410 supports MP remote UE operation and is in the RRC_CONNECTED state, which has been configured with an RRC connection to the base station 1420, the first UE 1410 may send an RRC message 1415 (e.g., SidelinkUEInformationNR) to the base station 1420 to request resources for sending / receiving discovery messages used in multipath relay. This information may be sent as shown in Table 1 below.

[0331] To distinguish between the purpose of discovery transmissions and the purpose of U2N relays, the first UE 1410 may include information indicating the transmission of multipath relay discovery (e.g., mp-Relay) in the sl-DiscoveryType or a similar IE. Furthermore, this may include the source L2ID for discovery transmissions for MP remote UEs.

[0332] Upon receiving an RRC message sent by the first UE 1410, the base station 1420 can configure resources and thresholds for the first UE 1410 to send / receive discovery messages for U2N relay and / or MP relay via RRC message 1416 (e.g., RRCReconfiguration).

[0333] According to embodiments of this disclosure, when the first UE 1410 supports U2N relay UE operation and is in the RRC_CONNECTED state where an RRC connection with base station 1420 is configured, base station 1420 can configure a range of thresholds for the first UE 1410's discovery message sending and / or receiving operations via RRC message 1416 (e.g., RRCReconfiguration). The thresholds can be configured by at least one of threshHighRemote and hystMaxRemote (or may include at least one of them).

[0334] According to embodiments of this disclosure, when the first UE 1410 supports U2N relay UE operation and is in an RRC_IDLE or RRC_INACTIVE state without an configured RRC connection to base station 1420, base station 1420 can configure a range of thresholds for the first UE 1410's discovery message sending and / or receiving operations via SIB message 1411 (e.g., SIB 12). The thresholds can be configured by at least one of threshHighRemote and hystMaxRemote (or may include at least one of them). If the value obtained by measuring the RSRP of the serving cell, primary cell, or camped cell is lower than (or less than) the value obtained by subtracting hystMaxRelay from threshHighRelay, the first UE 1410 can determine that it meets the threshold conditions for determining whether to operate as a U2N remote UE. When it is determined that the first UE 1410 meets the threshold conditions, the first UE 1410 can operate as a U2N remote UE.

[0335] Additionally, if the value obtained by measuring the RSRP of the serving cell, primary cell, or camped cell is higher than (greater than) threshHighRemote, then the first UE 1410 can determine that the first UE 1410 does not meet the threshold condition used to determine whether the first UE 1410 will operate as a U2N remote UE. When it is determined that the first UE 1410 does not meet the threshold condition, the first UE 1410 may not operate as a U2N remote UE. Such operation can be illustrated in Table 4 below.

[0336] [Table 4]

[0337]

[0338] For MP relay service to be provided smoothly, the Uu link quality of the MP remote UE may need to be good. That is, in direct paths with poor Uu link quality, frequent transmission failures and retransmissions may occur, which could adversely affect MP relay. Therefore, the upper limit threshold condition used by threshHighRemote and hystMaxRemote to determine whether to operate as a U2N remote UE needs to be configured with different values ​​for multipath relay.

[0339] Furthermore, if the U2N remote UE does not meet the threshold conditions—that is, if the Uu link quality with base station 1420 is good—the U2N remote UE may not send / receive discovery messages. Therefore, if the threshold conditions for U2N relay service and MP relay service are used equally, the MP remote UE may only receive MP relay service when the Uu link quality is poor, and may not be able to discover the MP relay UE when the Uu link quality is good. Additionally, unlike U2N relay, MP relay can provide increased reliability and throughput through additional indirect paths, even if the MP remote UE is in a good coverage area close to base station 1420. Furthermore, MP relay can be used to provide improved service even if both the MP relay UE and the MP remote UE are in a good coverage area close to base station 1420. Therefore, even if the UE is in a good coverage state that does not meet the U2N remote UE threshold conditions (i.e., Uu link quality equal to or higher than threshHighRemote), it is necessary to allow the UE to operate as an MP remote UE to provide extended service. In other words, the upper limit threshold conditions for determining whether to operate as a U2N remote UE, which can be configured by threshHighRemote and hystMaxRemote, can be configured differently and applied to MP remote UEs, thereby resolving existing operational issues that may occur when the threshold conditions for U2N remote UEs and the threshold conditions for MP remote UEs are used in the same way.

[0340] Additionally, according to embodiments of this disclosure, it is necessary to guarantee minimum Uu link quality through a lower threshold condition. The threshold to be applied to MP remote UEs (as an upper / lower threshold and the corresponding hysteresis added thereto) can have an IE (e.g., threshHighMPRemote, threshLowMPRemote, hystMaxMPRemote, hystMinMPRemote) that is different from the threshold applied to existing U2N remote UEs, to clearly indicate that the threshold is only used for MP remote UEs (and not U2N remote UEs), and can be used / defined / constructed / configured as shown in Table 5 below.

[0341] [Table 5]

[0342]

[0343] To configure and apply thresholds for MP remote UEs, when the first UE 1410 supports MP remote UE operation and is in the RRC_CONNECTED state where an RRC connection with base station 1420 is configured, base station 1420 can configure the range of thresholds for the first UE 1410's discovery message sending and / or receiving operations via RRC message 1416 (e.g., RRCReconfiguration). The thresholds can be configured by at least one of threshHighMPRemote, threshLowMPRemote, hystMaxMPRemote, and hystMinMPRemote (or may include at least one of these). When the first UE 1410 supports MP remote UE operation and is in the RRC_IDLE or RRC_INACTIVE state where no RRC connection with base station 1420 is configured, base station 1420 can configure the range of thresholds for the first UE 1410's discovery message sending and / or receiving operations via SIB 1411 (e.g., SIB12). Upon receiving SIB12, the first UE 1410 may apply the corresponding threshold, which may be configured by at least one of threshHighMPRemote, threshLowMPRemote, hystMaxMPRemote, and hystMinMPRemote (or may include at least one of them).

[0344] Figure 14b This is a flowchart illustrating the process by which a UE determines whether a threshold condition for multipath UE-network relay is met according to an embodiment of the present disclosure.

[0345] refer to Figure 14bIf the RSRP obtained by measuring the serving cell, primary cell, or camped cell is lower than (less than) the value obtained by subtracting hystMaxMPRemote from threshHighMPRemote, or if the RSRP obtained by measuring the serving cell, primary cell, or camped cell is higher than (greater than) the value obtained by adding hystMinMPRemote to threshLowMPRemote, then the UE supporting MP remote UE can determine that the UE meets the threshold conditions used to determine whether to operate as an MP remote UE. If the threshold conditions for determining whether to operate as an MP remote UE are met, the UE can operate as an MP remote UE. Alternatively, if the RSRP obtained by measuring the serving cell, primary cell, or camped cell is higher than (or greater than) threshHighMPRemote, or if the RSRP of the serving cell, primary cell, or camped cell measured by the UE supporting MP remote UE is lower than (or less than) threshLowMPRemote, then the UE supporting MP remote UE can determine that the UE no longer meets the threshold conditions used to determine whether to operate as an MP remote UE. If the threshold conditions used to determine whether to operate as an MP remote UE are not met, the UE may not operate as an MP remote UE. Additionally, if threshHighMPRemote or threshLowMPRemote is not configured, a UE supporting MP remote UE can determine that the UE always meets the threshHighMPRemote or threshLowMPRemote conditions used to determine whether to operate as an MP remote UE.

[0346] Figure 15 This is a flowchart illustrating a UE using a threshold for multipath UE-network relay operation according to an embodiment of the present disclosure.

[0347] refer to Figure 15 The first UE 1510 can be located within the coverage area (Coverage Area (IC)) of base station 1520 and can support multipath relay. When the first UE 1510 is in the RRC_CONNECTED state, the first UE 1510 can follow the configuration included in the RRC message (e.g., RRCReconfiguration) sent by base station 1520. Additionally, when the first UE 1510 is in the RRC_INACTIVE or RRC_IDLE state, the first UE 1510 can follow the configuration included in the SIB message (e.g., SIB12) sent by base station 1520. Figure 13a and Figure 14aThe MP relay thresholds described herein, applied to either an MP relay UE or an MP remote UE, can also be sent to and used by the first UE 1510 based on its RRC state using different methods (e.g., RRCReconfiguration or SIB12). In the absence of a configured threshold for determining whether to operate as an MP relay UE or an MP remote UE, the UE can determine that the threshold condition is always met, or it can follow the threshold condition used to determine whether to operate as a U2N relay UE or a U2N remote UE to determine whether to operate as an MP relay UE or an MP remote UE.

[0348] The first UE 1510, in the RRC_CONNECTED state, can confirm / determine / recognize whether to operate as an MP relay UE or an MP remote UE based on the UE capability information held by the base station 1520 (information received from the first UE 1510 via UE capability information, or information received from the AMF) or the UE capability information held by the first UE 1510. In the absence of a configured or defined reference... Figure 13a and Figure 14a In the case of the threshold applied to MP relay described, base station 1520 can configure the threshold applied to U2N relay used by first UE 1510 in RRC_CONNECTED state as the threshold applied to MP relay via RRC message 1511. That is, in the case where first UE 1510 is a U2N relay UE and in the case where first UE 1510 is an MP relay UE, at least one of threshHighRelay, threshLowRelay, hystMaxRelay, and hystMinRelay can be configured differently so that, in the absence of an explicit indication to first UE 1510 regarding the MP relay UE threshold, first UE 1510 can replace the threshold to be used for MP relay UE operation with the U2N relay UE threshold, and then use that threshold. Additionally, if the first UE 1510 is an MP remote UE, at least one of threshHighRemote and hystMaxRemote can be configured differently, such that without explicitly instructing the first UE 1510 about the MP remote UE threshold, the first UE 1510 can replace the threshold to be used in relation to the MP remote UE operation with the U2N remote UE threshold, and then use that threshold.

[0349] Reference Figure 13a and Figure 14aIn cases where the thresholds applied to MP relays and U2N relays are both provided to the first UE 1510 via RRC message 1511 or SIB message 1512, the AS layer of the first UE 1510 may not clearly recognize the reference thresholds. Figure 13a and Figure 14a Which value to use between the described MP relay and the threshold applied to U2N relay? The first UE 1510 can determine which threshold to use for MP relay by at least one of the following methods and configurations.

[0350] -Supports version 18 SL relay

[0351] - Supports version 18 multipath relay

[0352] - Capable of operating as a relay UE in version 18 multipath relay.

[0353] - Capable of operating as a remote UE in version 18 multipath relay.

[0354] - Configure the operation as a multipath relay UE in the upper layer (e.g., the ProSe layer).

[0355] - Configure the operation as a multipath remote UE in the upper layer (e.g., the ProSe layer).

[0356] -Base station 1520 configures the threshold applied to MP relays in the RRC message.

[0357] Base station 1520 instructs MP relay UE to operate via RRC message.

[0358] Base station 1520 instructs MP remote UE to operate via RRC message.

[0359] When the first UE 1510 is in the RRC_CONNECTED state, the base station 1520 can configure a threshold applied to MP relay in RRC message 1513. If the first UE 1510 recognizes that a threshold used in MP relay UEs and / or MP remote UEs is included in RRC message 1513, the first UE 1510 can determine whether the discovery transmit / receive condition is met by using the MP relay threshold. Alternatively, the base station 1520 can directly instruct the first UE 1510 to operate as an MP relay UE and / or MP remote UE via RRC message 1514, and the first UE 1510 can operate as an MP relay UE and / or MP remote UE until the corresponding configuration is released.

[0360] When the first UE 1510 is in the RRC_IDLE or RRC_INACTIVE state, the base station 1520 may include an MP relay threshold in SIB 1512 (e.g., SIB12) to indicate the MP relay threshold to a plurality of unspecified UEs, including the first UE 1510 in the RRC_IDLE or RRC_INACTIVE state. The SIB may not include UE-specific configurations that apply only to a specific UE (e.g., the first UE 1510) among the plurality of unspecified UEs in the RRC_IDLE or RRC_INACTIVE state. Therefore, in order for a specific UE (e.g., the first UE 1510) to use the MP relay threshold in the RRC_IDLE or RRC_INACTIVE state, the base station 1520 may send an indicator to the first UE 1510 in the RRC_CONNECTED state via RRC message 1515 (e.g., RRCLease) indicating that it uses the MP relay threshold even in the RRC_IDLE or RRC_INACTIVE state. An indicator indicating the use of the MP relay threshold even in RRC_IDLE or RRC_INACTIVE states can explicitly indicate MP relay UE or MP remote UE operation, or it can be an MP relay or MP remote threshold to be used in RRC_IDLE or INACTIVE. Upon receiving this indicator, the first UE 1510 can use the MP relay threshold included in SIB1512 in RRC_IDLE or RRC_INACTIVE. The base station 1520 can indicate a configurable timer along with the indicator to the first UE 1510, and the first UE 1510 can suspend the use of the MP relay threshold based on a combination of at least one of the following: an RRC state change to RRC_IDLE or RRC_INACTIVE; a deviation from the SI validity area; cell reselection; and timer expiration. If base station 1520 does not indicate to first UE 1510 via RRC message whether it is an MP relay UE or an MP remote UE, first UE 1510 may determine whether it can operate as an MP relay / remote UE based on UE capability information 1516 or upper-layer (e.g., ProSe) configuration 1517. If base station 1520 includes a threshold to be used in MP relay in SIB 1512, first UE 1510 may use that threshold for MP relay / remote UEs in RRC_IDLE or RRC_INACTIVE states.

[0361] Figure 16 This is a flowchart illustrating a UE performing measurements and measurement reports in a multipath UE-network relay according to an embodiment of the present disclosure.

[0362] refer to Figure 16The first UE 1610 and the second UE 1620 can be within the coverage area of ​​the base station 1630, and the first UE 1610 can operate as an MP remote UE, and the second UE 1620 can operate as an MP relay UE.

[0363] To enable the first UE 1610 to measure L2 U2N relay UEs or L2 MP relay UEs (e.g., the second UE 1620), the base station 1630 can configure a measurement configuration for the first UE 1610 as an L2U2N relay object via RRC messages on either the indirect path 1611 or the direct path 1612. With the L2 U2N relay object configured, the first UE 1610 performs measurements on the serving NR cell and candidate L2 U2N relay UEs, and reports the measurement results (1613 and 1614). (For L2U2N relay objects, the UE measures and reports the serving NR cell and the discovered L2U2N relay UEs.)

[0364] In the case where the first UE 1610 and the second UE 1620, as well as the first UE 1610 and the base station 1630 are connected via an MP relay, the base station 1630 can configure the first UE 1610 to measure candidate MP relay UEs located near the first UE 1610, and can perform indirect path handover based on information about candidate MP relay UEs included in the measurement results reported by the first UE 1610. The first UE 1610 needs to simultaneously measure and report not only the candidate MP relay UEs, but also the serving MP relay UE (i.e., the second UE 1620). Therefore, the base station 1630 can compare the link quality reported by the first UE 1610 between the first UE 1610 and the serving MP relay UE with the link quality between the first UE 1610 and the candidate MP relay UE, and can perform related operations such as indirect path changes. Furthermore, if the U2N remote UE can simultaneously measure and transmit link quality with both the serving L2U2N relay UE and the candidate L2U2N relay UE, the base station 1630 can perform path handover operations, such as indirect path handover. Therefore, when configuring an L2 U2N relay target for the first UE 1610, the first UE 1610 needs to perform measurements and report measurement results for the serving NR cell, the serving relay UE, and the candidate L2 U2N relay UE. (That is, for the L2 U2N relay target, the UE measures and reports the serving NR cell, the serving relay UE, and the discovered L2 U2N relay UE.)

[0365] The operation of an L2 MP remote UE measuring and reporting measurement results to an L2 MP relay UE can be processed in the same way as the operation of an L2 U2N remote UE measuring and reporting measurement results to an L2 U2N relay UE. That is, both the L2 MP relay UE and the L2 MP remote UE can be UEs capable of performing MP relay operations within an L2 U2N relay UE, and can also be UEs capable of performing MP remote operations within an L2 U2N remote UE. In other words, within an L2 U2N relay UE, a UE capable of performing MP relay operations can be an L2 MP relay UE, and within an L2 U2N remote UE, a UE capable of performing MP remote operations can be an L2 MP remote UE. In another case, the L2 U2N relay UE and the L2 U2N remote UE, as well as the L2 MP relay UE and the L2 MP remote UE, can perform different operations, such that operations not performed by the L2 U2N relay UE or the L2 U2N remote UE can be included in the operations of the L2 MP relay UE or the L2 MP remote UE. Such operations may include references... Figure 13a , Figure 14a and Figure 15 The description covers the operations for determining and using MP relay UE thresholds and MP remote UE thresholds.

[0366] Furthermore, operations 1613 and 1614, in which the first UE 1610 performs measurements and reports regarding the second UE 1620 (indirect path) and base station 1630 (direct path), can be included in the measurement and measurement reporting operations within the multi-path UE network relay. That is, the MP remote UE can include measurement results regarding the serving L2 MP relay UE and serving NR cell configured in servingCellMO in its measurement report.

[0367] When an MP remote UE (e.g., the first UE 1610) reports measurement results about an MP relay UE (e.g., the second UE 1620) to base station 1630, it may include the identifier of the MP relay UE's PCell or the cell it is camped on, the L2ID sent by the MP relay UE for sidelink discovery and / or sidelink communication, and the results of measuring the corresponding sidelink signal, and may be constructed / configured / defined as shown in Table 6 below.

[0368] [Table 6]

[0369]

[0370] According to embodiments of this disclosure, MP relay can consider scenarios where both the MP remote UE (e.g., first UE 1610) and the MP relay UE (e.g., second UE 1620) are served by the same base station 1630. In this case, when measuring and reporting the serving relay UE, the first UE 1610 may not include the cell identifier because the PCell or camped cell of the first UE 1610 and the second UE 1620 are connected to the same base station 1630 of the first UE 1610 and the second UE 1620 respectively via direct links. That is, the cellIdentity in Table 6 above may not be sent.

[0371] According to embodiments of this disclosure, when a first UE 1610 is performing an MP relay operation in which both direct and indirect paths are configured, base station 1630 may instruct the first UE 1610 to discover and measure candidate relay UEs for purposes such as indirect path changes. The PCell or camped cell of the candidate relay UE may be different from the PCell or camped cell of the first UE 1610. In this case, the candidate relay UE and the first UE 1610 may not be served by the same base station 1630, and therefore, the first UE 1610 may determine not to report candidate relay UEs that are not served by the PCell or camped cell of the first UE 1610.

[0372] To distinguish between reporting operations in scenarios where both MP remote UEs (e.g., the first UE 1610) and MP relay UEs (e.g., the second UE 1620) are served by the same base station 1630, and reporting operations in scenarios where both MP remote UEs (e.g., the first UE 1610) and MP relay UEs (e.g., the second UE 1620) are served by different base stations 1630, base station 1630 may separately indicate L2 U2N relay measurement objects and L2 MP relay measurement objects to the UE when instructing reporting operations.

[0373] Additionally, if the indirect and direct paths are configured to pass through different base stations 1630, the cell identifier may need to be included in the candidate relay UE's measurement report. Therefore, considering the case of configuring paths through different base stations 1630, the cell identifier in Table 6 can be reported as needed (optionally).

[0374] Figure 17 This is a flowchart illustrating how a UE performs measurements and reports in a multipath UE-network relay according to embodiments of this disclosure.

[0375] refer to Figure 17The first UE 1710, the second UE 1720, and the third UE 1730 can be within the coverage area of ​​the base station 1740, and the first UE 1710 can operate as an MP remote UE, while the second UE 1720 and the third UE 1730 can operate as MP relay UEs. The second UE 1720 can be the serving relay UE of the first UE 1710.

[0376] Reference Figure 17 Base station 1740 can configure the first UE 1710 to consider one or more of the serving NR cell, serving relay UE, neighboring NR cells, and candidate relay UEs in conjunction with the measurement report triggering event. That is, when the first UE 1710 provides U2N relay service to base station 1740 through the second UE 1720, base station 1740 can add a direct path for the first UE 1710 to communicate directly with base station 1740, thereby configuring (1711) to identify whether a measurement report triggering event is suitable for providing MP relay service via a direct path. The measurement report triggering event can be satisfied when the link quality of the PC5 link between the first UE 1710 and the second UE 1720 is equal to or higher than a specific threshold PC5 link quality. Alternatively, a measurement report trigger event can be satisfied when the PC5 link quality between the first UE 1710 and the second UE 1720 is equal to or higher than a specific threshold PC5 link quality, and the Uu link quality between the first UE 1710 and the base station 1740 is equal to or higher than a specific threshold Uu link quality. The unit used by the first UE 1710 to measure the signal strength of the second UE 1720 (i.e., the serving U2N relay) can be either the Sidelink Reference Received Signal Power (SL-RSRP) based on the signal strength of sidelink communication, or the Sidelink Discovery Reference Received Signal Power (SD-RSRP) based on the signal strength of sidelink discovery messages. The base station 1740 can individually specify / configure the unit to be used for measuring the second UE 1720 for each measurement report trigger event for the first UE 1710, and can specify / configure one or both SL-RSRP and SD-RSRP as the measurement unit. The measurement unit can also be applied to measurement report triggering events associated with the first UE 1710 and the second UE 1720, or a third UE 1730 not connected to the first UE 1710, or other UEs not shown in the figures. The conditions for such measurement report triggering events can be as follows.

[0377] - When the PC5 link quality between the remote UE and the serving relay UE is equal to or higher than the threshold.

[0378] - When the PC5 link quality between the remote UE and the serving relay UE is equal to or higher than the threshold, and the Uu link quality between the remote UE and the NR cell is equal to or higher than the threshold.

[0379] Upon fulfilling the conditions of the measurement report trigger event (1712), the first UE 1710 may include measurement results and additional information in the measurement report message. This additional information may include the serving cell, NR cell, serving relay UE, and candidate relay UE configured to be measured by the first UE 1710 through the measurement object. The measurement results may include one of the SL-RSRP and SD-RSRP configured by the base station 1740, or both SL-RSRP and SD-RSRP. To match the measurement unit configured by the base station 1740 with the measurement unit reported by the first UE 1710, the configuration for explicitly indicating whether the measurement result is SL-RSRP or SD-RSRP can be configured / constructed / defined as shown in Table 7 below.

[0380] [Table 7]

[0381]

[0382] When the first UE 1710 is configured to measure and report on candidate relay UEs that are not serving relay UEs, the measurement unit for the candidate relay UE may differ from the reporting unit for the serving relay UE. For example, if the first UE 1710 is configured to measure and report the SL-RSRP of the candidate relay UE, but the serving relay UE of the first UE 1710 does not send sidelink data, the SL-RSRP of the serving relay UE of the first UE 1710 may not be measured, and the SD-RSRP may be measured only through the sidelink discovery message of the serving relay UE of the first UE 1710. In this case, comparing the PC5 link quality of the candidate relay UE with that of the serving relay UE may be difficult, and therefore, even if the base station 1740 receives the measurement report, it may be difficult to manage the indirect path of the first UE 1710. Therefore, an explicit indication and reporting process for the measurement units of the serving relay UE and the candidate relay UE measured by the first UE 1710 may be necessary. When measurement results for the serving relay UE of the first UE 1710 are included in the measurement report of the first UE 1710, the measurement results may include SL-RSRP, and when there is no sidelink data transmission, the measurement results may include SD-RSRP. According to embodiments of this disclosure, the first UE 1710 may measure the candidate relay UE in units of SL-RSRP or SD-RSRP, and the base station 1740 may configure thresholds for SL-RSRP and / or SD-RSRP. Even without explicitly configuring measurement units for the serving relay UE, the first UE 1710 may report (1713) the measurement results of the serving relay UE by using the same measurement unit configured for the unit used to report the measurement report triggering event for the candidate relay UE (i.e., the measurement unit ReportConfig associated with the L2U2N relay measurement object). For example, if the configured measurement report trigger condition for the candidate relay UE is SD-RSRP, the measurement report 1713 reported due to the fulfillment of the configured measurement report trigger condition for the candidate relay UE may include the result of the first UE 1710 measuring the SD-RSRP of the serving relay UE. Alternatively, at least one of the currently reportable measurement results for the serving relay UE, namely SD-RSRP and SL-RSRP, may be included in the measurement report 1713.

[0383] Figure 18 This is a flowchart illustrating a UE selecting or reselecting a relay UE during multipath UE-network relay operation according to an embodiment of the present disclosure.

[0384] When the first UE operates as a U2N remote UE, the first UE can select or reselect a U2N relay UE to use the U2N relay service. Conditions for the first UE to select or reselect a U2N relay UE may include: the absence of a serving cell for the first UE; the RSRP of the currently camped cell or PCell meeting the threshold conditions for a U2N remote UE and no U2N relay UE being selected; the serving relay UE's SL-RSRP being worse than sl-RSRP-Thresh; the serving relay UE's SL-RSRP being unavailable; the serving relay UE's SD-RSRP being worse than sl-RSRP-Thresh; the upper layer indicating that the serving relay UE should not be used; the upper layer indicating that the PC5-RRC connection with the serving relay UE has been released; and an RLF being detected in the sidelink with the serving relay UE. In cases where at least one of the conditions included in the first UE's selection or reselection of a U2N relay UE is present, a discovery procedure for discovering candidate relay UEs can be performed. Among the discovered candidate relay UEs, those that meet the AS layer threshold (e.g., sl-RSRP-thresh) can be considered as selection targets. Such a process can be illustrated exemplarily in Table 8 below.

[0385] [Table 8]

[0386]

[0387] Unlike U2N relay, the selection or reselection of the MP relay UE for the first UE's MP relay service can be performed by the base station. That is, instead of performing the selection or reselection of the MP relay UE, the first UE performs a process of measuring candidate MP relay UEs and reporting the measurement results to the base station. Through this process, the base station, which has received candidate MP relay UEs from the first UE, can select the MP relay UE to use in the indirect path.

[0388] To prevent an MP remote UE from selecting or reselecting an MP relay UE, the UE may not select or reselect the relay UE under at least one of the following conditions.

[0389] - UEs configured as MP remote UEs and operating accordingly, i.e. UEs configured with direct and indirect paths, do not select or reselect MP relay UEs.

[0390] - In UEs communicating via direct path, UEs that meet the MP remote UE threshold condition do not select or reselect an MP relay UE. If the U2N remote UE threshold condition is also met, the conditions for selecting or reselecting a U2N remote UE can be followed.

[0391] Figure 19This is a flowchart illustrating a UE reporting an indirect path failure to a base station during multipath UE-network relay operation according to an embodiment of the present disclosure.

[0392] refer to Figure 19 The first UE 1910 and the second UE 1920 can be within the coverage area of ​​the base station 1930. The first UE 1910 can operate as an MP remote UE, and the second UE 1920 can operate as an MP relay UE. The first UE 1910 can be in the middle of an MP relay operation, wherein an indirect path through the second UE 1920 and a direct path through the base station 1930 are configured in the MP relay operation.

[0393] If the first UE 1910 detects a (1911) PC5 RLF or link failure in a connection with the second UE, the first UE 1910 can notify the base station 1930 of the indirect path failure report via the direct link using RRC message 1912. A PC5 RLF can be detected if at least one of the following conditions is met: a specified number of RLC retransmissions for a specific target has occurred; a T400 timer for a specific target has expired; a specified number of HARQ DRXs for a specific target has occurred; or an integrity check for SL-SRB2 or SL-SRB3 for a specific target has failed. Additionally, when using radio access technologies other than 3GPP, link failures can be detected using detection methods employed by the radio access technology.

[0394] Besides the scenario where the first UE 1910 detects a PC5 RLF and a link failure related to the second UE 1920, the first UE 1910 can also terminate its connection with the second UE 1920 via an upper-layer interruption. For example, the upper layer of the first UE 1910 can issue instruction 1913 to release the PC5-RRC connection with the second UE 1920. Alternatively, the upper layer of the first UE 1910 can issue instruction 1913 to cease using MP relay with the second UE 1920. In this case, the first UE 1910 may not send an indirect path failure report to the base station 1930 because no PC5 RLF or link failure has occurred, and therefore, the base station 1930 may not be aware of the reason for the termination of the connection between the first UE 1910 and the second UE 1920. Therefore, if the first UE 1910 has terminated PC5-RRC through the upper layer or no longer uses the second UE 1920 as an MP relay UE (1913), it may be necessary for the first UE 1910 to notify the base station 1930 of its method.

[0395] According to embodiments of this disclosure, the first UE 1910 can use an indirect path failure report 1914, and can send the indirect path failure report 1914 to the base station 1930 using either an indirect path or a direct path. Message 1914 may include an indicator for notifying the base station 1930 that the upper layer has requested PC5-RRC release or has sent an instruction to no longer use the second UE 1920, and may include an identifier (e.g., L2ID) for identifying the second UE 1920, as well as identifiers for the second UE's serving cell, PCell, and camped cell.

[0396] According to embodiments of this disclosure, in another method, the first UE 1910 may send an RRC message 1915 (e.g., sidelinkUEInformationNR) to the base station 1930 using an indirect or direct path, thereby ceasing to request resources from the base station 1930 for communication with the second UE 1920. This message 1915 may include an identifier (e.g., L2ID) for identifying the second UE 1920, as well as an identifier for the second UE's serving cell, PCell, or camped cell. The base station 1930 may identify that the first UE 1910 has not continued communication with the second UE 1920 based on the fact that the first UE 1910 has not requested resources for communication with the second UE 1920.

[0397] According to embodiments of this disclosure, in another approach, a first UE 1910 may send an RRC message 1916 (e.g., sidelinkUEInformationNR) to a base station 1930 using either an indirect or direct path. This RRC message 1916 includes information indicating that the first UE 1910 no longer communicates with the second UE 1920. The message 1916 may include an identifier (e.g., L2ID) for identifying the second UE 1920, as well as an identifier for the second UE's serving cell, PCell, or camped cell. By including such information, the base station 1930 can efficiently utilize resources through management such as releasing indirect paths that may no longer be used.

[0398] The methods described in the claims or specification of this disclosure can be implemented in software, hardware, or a combination of hardware and software.

[0399] Regarding the software, a computer-readable storage medium may be provided 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 of an electronic device. The one or more programs may include instructions for instructing the electronic device to perform methods according to the embodiments described in the claims or specification of this disclosure.

[0400] Such programs (software modules, software) can be stored in random access memory, non-volatile memory including flash memory, read-only memory (ROM), electrically erasable programmable ROM (EEPROM), disk storage devices, optical disc (CD-ROM), digital versatile optical disc (DVD), or other optical storage devices and magnetic tape cassettes. Optionally, they can be stored in a memory incorporating some or all of the aforementioned recording media. Multiple memories may be included.

[0401] Furthermore, the program can be stored in an attachable storage device accessible via a communication network, including the Internet, intranet, local area network (LAN), wireless local area network (WLAN), or storage area network (SAN), or a combination of these networks. Such a storage device can access the device executing embodiments of this disclosure via an external port. Additionally, a separate storage device on the communication network can access the device executing embodiments of this disclosure.

[0402] In specific embodiments of this disclosure, the components included in this disclosure are represented in singular or plural form. However, the singular or plural form is appropriately chosen for ease of explanation based on the proposed scenario. This disclosure is not limited to a single component or multiple components; a component represented in plural form may be configured as a single component, and a component represented in singular form may be configured as multiple components.

[0403] The embodiments of this disclosure described and illustrated in the specification and drawings are merely specific examples provided to facilitate understanding of the technical content of this disclosure, and are intended to aid in understanding, not to limit the scope of this disclosure. For example, those skilled in the art will recognize that other variations can be implemented based on the technical concepts of this disclosure. Furthermore, the above embodiments can be combined with each other as needed. For example, a portion of one embodiment of the present invention can be combined with a portion of another embodiment to operate a base station and a terminal. As an example, a portion of Embodiment 1 of this disclosure can be combined with a portion of Embodiment 2 to operate a base station and a terminal. In addition, although the above embodiments are based on an FDD LTE system, other variations based on the technical ideas of the above embodiments can also be implemented in other systems, such as TDD LTE, 5G, or NR systems.

[0404] In the accompanying drawings describing the methods of this disclosure, the order of description does not always correspond to the order in which the method steps are executed. The order of the steps can be adjusted, or the steps can be executed in parallel.

[0405] Optionally, in the accompanying drawings describing the methods of this disclosure, some elements may be omitted or only some elements may be included without departing from the basic spirit and scope of this disclosure.

[0406] Furthermore, in the methods disclosed herein, some or all of the contents of each embodiment can be combined to implement the methods without departing from the basic spirit and scope of this disclosure.

[0407] Various embodiments of this disclosure have been described above. The above description is for illustrative purposes and is not intended to limit the embodiments of this disclosure to those set forth herein. Those skilled in the art will understand that other specific modifications and changes can be readily made to the form of this disclosure without altering its technical concept or essential characteristics. The scope of this disclosure is defined by the appended claims, not by the detailed description above, and the scope of this disclosure should be construed as including all changes or modifications derived from the meaning and scope of the claims and their equivalents.

Claims

1. A method performed by a first terminal in a wireless communication system, the method comprising: Receive signals from the second terminal for measurements regarding the side link with the second terminal; as well as Send a measurement report, including measurement results based on the signal, to a second terminal or base station. The measurement report includes information indicating the measurement unit on which the measurement results are based.

2. The method according to claim 1, wherein, The information from the measurement unit indicates one of the sidelink reference signal received power (SL-RSRP) and the sidelink discovery reference signal received power (SD-RSRP).

3. The method according to claim 2, wherein, Measurement results include those based on SL-RSRP or those based on SD-RSRP.

4. The method according to claim 2, wherein, There is no separate configuration for the measurement unit for the first terminal.

5. A method performed by a second terminal in a wireless communication system, the method comprising: Send a signal to the first terminal for measurements of the side link with the first terminal; as well as Receive a measurement report from the first terminal, including measurement results based on the signal. The measurement report includes information indicating the measurement unit on which the measurement results are based.

6. The method according to claim 5, wherein, The information from the measurement unit indicates one of the sidelink reference signal received power (SL-RSRP) and the sidelink discovery reference signal received power (SD-RSRP).

7. The method according to claim 6, wherein, Measurement results include those based on SL-RSRP or those based on SD-RSRP.

8. The method according to claim 6, wherein, There is no separate configuration for the measurement unit for the first terminal.

9. A first terminal in a wireless communication system, the first terminal comprising: transceiver; as well as The controller is connected to the transceiver. The controller is configured as follows: Receive signals from the second terminal for measurements regarding the side link with the second terminal; and Send a measurement report, including measurement results based on the signal, to a second terminal or base station. The measurement report includes information indicating the measurement unit on which the measurement results are based.

10. The first terminal according to claim 9, wherein, The information from the measurement unit indicates one of the sidelink reference signal received power (SL-RSRP) and the sidelink discovery reference signal received power (SD-RSRP).

11. The first terminal according to claim 10, wherein, Measurement results include those based on SL-RSRP or those based on SD-RSRP.

12. The first terminal according to claim 10, wherein, There is no separate configuration for the measurement unit for the first terminal.

13. A second terminal in a wireless communication system, the second terminal comprising: transceiver; as well as The controller is connected to the transceiver. The controller is configured as follows: Send a signal to the first terminal for measurements regarding the side link with the first terminal; and Receive a measurement report from the first terminal, including measurement results based on the signal. The measurement report includes information indicating the measurement unit on which the measurement results are based.

14. The second terminal according to claim 13, wherein, The information from the measurement unit indicates one of the sidelink reference signal received power (SL-RSRP) and the sidelink discovery reference signal received power (SD-RSRP).

15. The second terminal according to claim 14, wherein, Measurement results include those based on SL-RSRP or those based on SD-RSRP.

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