Method and apparatus for a multi-hop sidelink relay communication in a wireless communication system

Abstract

The present disclosure provides a method performed by a network node, a method performed by a node, and a network node and a node in a wireless communication system. A method performed by a second node in a wireless communication system comprising: receiving a first configuration message transmitted by a first network node; receiving a first notification message transmitted by a first node, and transmitting a second notification message to a third node, wherein the second notification message is used to notify information on a link where the second node is located.

Description

METHOD AND APPARATUS FOR A MULTI-HOP SIDELINK RELAY COMMUNICATION IN A WIRELESS COMMUNICATION SYSTEM

[0001] The application relates generally to the field of wireless communications, and more specifically, to a method performed by a network node, a method performed by a node, and a network node and a node.

[0002] 5G mobile communication technologies define broad frequency bands such that high transmission rates and new services are possible, and can be implemented not only in “Sub 6GHz” bands such as 3.5GHz, but also in “Above 6GHz” bands referred to as mmWave including 28GHz and 39GHz. In addition, it has been considered to implement 6G mobile communication technologies (referred to as Beyond 5G systems) in terahertz (THz) bands (for example, 95GHz to 3THz bands) in order to accomplish transmission rates fifty times faster than 5G mobile communication technologies and ultra-low latencies one-tenth of 5G mobile communication technologies.

[0003] At the beginning of the development of 5G mobile communication technologies, in order to support services and to satisfy performance requirements in connection with enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), there has been ongoing standardization regarding beamforming and massive MIMO for mitigating radio-wave path loss and increasing radio-wave transmission distances in mmWave, supporting numerologies (for example, operating multiple subcarrier spacings) for efficiently utilizing mmWave resources and dynamic operation of slot formats, initial access technologies for supporting multi-beam transmission and broadbands, definition and operation of BWP (BandWidth Part), new channel coding methods such as a LDPC (Low Density Parity Check) code for large amount of data transmission and a polar code for highly reliable transmission of control information, L2 pre-processing, and network slicing for providing a dedicated network specialized to a specific service.

[0004] Currently, there are ongoing discussions regarding improvement and performance enhancement of initial 5G mobile communication technologies in view of services to be supported by 5G mobile communication technologies, and there has been physical layer standardization regarding technologies such as V2X (Vehicle-to-everything) for aiding driving determination by autonomous vehicles based on information regarding positions and states of vehicles transmitted by the vehicles and for enhancing user convenience, NR-U (New Radio Unlicensed) aimed at system operations conforming to various regulation-related requirements in unlicensed bands, NR UE Power Saving, Non-Terrestrial Network (NTN) which is UE-satellite direct communication for providing coverage in an area in which communication with terrestrial networks is unavailable, and positioning.

[0005] Moreover, there has been ongoing standardization in air interface architecture / protocol regarding technologies such as Industrial Internet of Things (IIoT) for supporting new services through interworking and convergence with other industries, IAB (Integrated Access and Backhaul) for providing a node for network service area expansion by supporting a wireless backhaul link and an access link in an integrated manner, mobility enhancement including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access for simplifying random access procedures (2-step RACH for NR). There also has been ongoing standardization in system architecture / service regarding a 5G baseline architecture (for example, service based architecture or service based interface) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) for receiving services based on UE positions.

[0006] As 5G mobile communication systems are commercialized, connected devices that have been exponentially increasing will be connected to communication networks, and it is accordingly expected that enhanced functions and performances of 5G mobile communication systems and integrated operations of connected devices will be necessary. To this end, new research is scheduled in connection with eXtended Reality (XR) for efficiently supporting AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality) and the like, 5G performance improvement and complexity reduction by utilizing Artificial Intelligence (AI) and Machine Learning (ML), AI service support, metaverse service support, and drone communication.

[0007] Furthermore, such development of 5G mobile communication systems will serve as a basis for developing not only new waveforms for providing coverage in terahertz bands of 6G mobile communication technologies, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas and large-scale antennas, metamaterial-based lenses and antennas for improving coverage of terahertz band signals, high-dimensional space multiplexing technology using OAM (Orbital Angular Momentum), and RIS (Reconfigurable Intelligent Surface), but also full-duplex technology for increasing frequency efficiency of 6G mobile communication technologies and improving system networks, AI-based communication technology for implementing system optimization by utilizing satellites and AI (Artificial Intelligence) from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technology for implementing services at levels of complexity exceeding the limit of UE operation capability by utilizing ultra-high-performance communication and computing resources.

[0008] The present disclosure relates generally to the field of wireless communications, and more specifically, to a method performed by a network node, a method performed by a node, and a network node and a node.

[0009] Embodiments of the present disclosure provide a method performed by a network node, a method performed by a node, and a network node and a node. The technical solutions provided by the embodiments of the present disclosure are as follows:

[0010] An embodiment of the present disclosure provides a method performed by a second node in a wireless communication system, including:

[0011] receiving a first configuration message related to a multi-hop sidelink relay network serving a first user equipment transmitted by a first network node,

[0012] receiving a first notification message transmitted by a first node, wherein the first notification message is used to notify information on a link where the first node is located, and / or

[0013] transmitting a second notification message to a third node, wherein the second notification message is used to notify information on a link where the second node is located;

[0014] wherein the first configuration message includes at least one of the following information: identification information indicating a node served by the second node, path configuration information indicating one or more paths served by the second node, first notification configuration information used to indicate the second node to transmit the second notification message, state configuration indication information used to indicate the connection state of the second node, and data transmission configuration information used to configure a relay node to perform data transmission in an idle state or an inactive state;

[0015] wherein the first notification message and / or the second notification message includes at least one of the following information: indication information on a device type, supported hop count information, hop count information of a transmission path, relay node reselection indication information, relay node selection indication information, reestablishment indication information, reestablishment failure indication information, first path interruption indication information used to indicate transmission path failure or interruption or unavailable, a notification message container containing notification messages transmitted by other relay nodes, and first assistant information for assisting in learning a link change;

[0016] wherein the first node, the second node and the third node are relay nodes in the multi-hop sidelink relay network.

[0017] According to a possible embodiment of the present disclosure, it further comprises transmitting a first assistant message to a first network node, wherein the first assistant message is used to help the first network node configure a transmission path serving the first user equipment, and includes at least one of the following information: identification information of a node to which the second node is connected, identification information of a serving cell of the node to which the second node is connected, identification information of a path where the second node is located, identification information of the first user equipment served by the second node, and information used to indicate data termination.

[0018] According to a possible embodiment of the present disclosure, it further comprises transmitting the second notification message if a cell to which the second node is connected is different from a serving cell of the first user equipment, or

[0019] transmitting a reestablishment connection request message if the cell to which the second node is connected is different from the serving cell of the first user equipment;

[0020] wherein the cell to which the second node is connected is a serving cell of a relay node selected after the second node performs relay node selection or reselection, or a cell selected after the second node performs reestablishment or cell selection or reselection.

[0021] According to a possible embodiment of the present disclosure, wherein after receiving the first notification message, at least one of the following behaviors is also included:

[0022] starting a first timer, wherein the first timer is used to determine a time taken by the second node to perform at least one of selection or reselection of a relay node, reestablishment, cell selection or reselection, handover, connection setup, connection resume, waiting for a request of the first user equipment;

[0023] transmitting the second notification message;

[0024] resuming a link, wherein the resuming the link includes at least one of reestablishment of the link and establishment of the link again;

[0025] entering an idle state;

[0026] entering an inactive state.

[0027] According to a possible embodiment of the present disclosure, wherein the second notification message is transmitted when at least one of the following conditions is met:

[0028] the second node is a relay node in the multi-hop relay network;

[0029] the second node receives the first notification message;

[0030] the second node is in a connected state;

[0031] the second node is in an idle or inactive state;

[0032] the second node fails to complete at least one of relay node selection or reselection, reestablishment, cell selection or reselection, handover, connection setup and connection resume before the second timer expires;

[0033] at least one behavior of relay node reselection or selection, reestablishment, a link failure, handover, cell reselection or selection, a sidelink release has occurred at the second node.

[0034] According to a possible embodiment of the present disclosure, wherein the path configuration information includes at least one of the following information: identification information of the user equipment, path identification information; and / or

[0035] the first notification configuration information includes at least one of the following information: time indication information used to indicate time that the second node needs to wait before transmitting the second notification message, relay node behavior indication information used to indicate a behavior that the second node is allowed to perform; and / or

[0036] the state configuration indication information includes at least one of the following information: state indication information used to indicate one of a connected state, an idle state and an inactive state, cell identification information, and state condition indication information used to indicate a condition of a state which the relay node is in; and / or

[0037] the data transmission configuration information includes at least one of the following information: configuration retention indication information used to indicate a configuration that the second node needs to retain, and condition indication information used to indicate a condition for the second node to perform data transmission.

[0038] According to a possible embodiment of the present disclosure, wherein the first assistant information includes at least one of the following information:

[0039] identification information of a cell, wherein the cell is a cell selected during a cell selection process of the second node, or a cell selected during a cell reselection process, or a cell selected for reestablishment, or a target cell for handover, a cell serving a relay node accessed by the second node, and a serving cell of a path where the second node is located;

[0040] identification information of a node, wherein the node is a node reselected by the second node, or a node selected by the second node, and a node where a sidelink failure occurs;

[0041] identification information of a link;

[0042] indication information of a link type.

[0043] According to a possible embodiment of the present disclosure, the establishment of the link again includes at least one of relay node selection or reselection, reestablishment, cell reselection or selection.

[0044] According to a possible embodiment of the present disclosure, wherein the first assistant message is transmitted after at least one of the following conditions is met:

[0045] a serving cell of a relay node selected by the second node through a relay node reselection or selection process is the same as a serving cell of the first user equipment;

[0046] a cell selected by the second node through a cell selection or reselection process is the same as the serving cell of the first user equipment;

[0047] the second node completes a connection setup or connection resume process, and the second node serves the first user equipment in an idle state or an inactive state.

[0048] According to a possible embodiment of the present disclosure, the multi-hop sidelink relay network includes the first network node, the first user equipment, the first node, the second node, and the third node.

[0049] According to a possible embodiment of the present disclosure, wherein the first configuration message is a connection release message,

[0050] The first assistant message includes at least one of a connection setup complete message, a reestablishment complete message, or a resume complete message.

[0051] Embodiments of the present disclosure also provide a method performed by a first network node in a wireless communication system, comprising:

[0052] transmitting, to a second node, a first configuration message related to a multi-hop sidelink relay network serving a first user equipment,

[0053] receiving a first assistant message transmitted by a second node, wherein the first assistant message is used to help the first network node configure a transmission path serving the first user equipment,

[0054] wherein the first configuration message includes at least one of the following information: identification information indicating a node served by the second node, path configuration information indicating one or more paths served by the second node, first notification configuration information used to indicate the second node to transmit the second notification message, state configuration indication information used to indicate the connection state of the second node, and data transmission configuration information used to configure a relay node to perform data transmission in an idle state or an inactive state.

[0055] According to a possible embodiment of the present disclosure, it further comprises

[0056] transmitting, to the first user equipment, a second configuration message, wherein the second configuration message is used to configure an access to a multi-hop sidelink relay network, the second configuration includes at least one of the following information:

[0057] first hop count information used to indicate a hop count of the multi-hop sidelink relay network serving the first user equipment,

[0058] first time information used to indicate a length of time for the first user equipment to perform connection setup or connection reestablishment or connection resume,

[0059] reference time information used to indicate a reference length of time for the first user equipment to perform connection setup or connection reestablishment or connection resume,

[0060] first time step information used to indicate an increase step of the length of time,

[0061] first time increment information used to indicate information of an increase in a time length.

[0062] According to a possible embodiment of the present disclosure, the first assistant message includes at least one of the following information: identification information of a node to which the second node is connected, identification information of a serving cell of the node to which the second node is connected, identification information of a path where the second node is located, identification information of the first user equipment served by the second node.

[0063] According to a possible embodiment of the present disclosure, wherein the path configuration information includes at least one of the following information: identification information of the user equipment, path identification information; and / or

[0064] the first notification configuration information includes at least one of the following information: time indication information used to indicate time that the second node needs to wait before transmitting the second notification message, relay node behavior indication information used to indicate a behavior that the second node is allowed to perform; and / or

[0065] the state configuration indication information includes at least one of the following information: state indication information used to indicate one of a connected state, an idle state and an inactive state, cell identification information, and state condition indication information used to indicate a condition of a state which the relay node is in; and / or

[0066] the data transmission configuration information includes at least one of the following information: configuration retention indication information used to indicate a configuration that the second node needs to retain, and condition indication information used to indicate a condition for the second node to perform data transmission.

[0067] According to a possible embodiment of the present disclosure, wherein the first configuration message is a connection release message,

[0068] The first assistant message includes at least one of a connection setup complete message, a reestablishment complete message, or a resume complete message.

[0069] Embodiments of the present disclosure also provide a method performed by a first user equipment in a wireless communication system, comprising:

[0070] receiving a second configuration message used to configure an access to a multi-hop sidelink relay network transmitted by a first network node,

[0071] starting a timer for connection setup or connection reestablishment or connection resume,

[0072] performing connection setup or connection reestablishment or connection resume.

[0073] According to a possible embodiment of the present disclosure, wherein the second configuration includes at least one of the following information:

[0074] first hop count information used to indicate a hop count of the multi-hop sidelink relay network serving the first user equipment,

[0075] first time information used to indicate a length of time for the first user equipment to perform connection setup or connection reestablishment or connection resume,

[0076] reference time information used to indicate a reference length of time for the first user equipment to perform connection setup or connection reestablishment or connection resume,

[0077] first time step information used to indicate an increase step of the length of time,

[0078] first time increment information used to indicate information of an increase in a time length.

[0079] According to a possible embodiment of the present disclosure, wherein according to information in the second configuration message, a length of the timer is determined according to at least one of the following methods:

[0080] based on the first hop count information and the first time information;

[0081] based on the first hop count information, the reference time information, and the first time step information;

[0082] based on the first hop count information, the reference time information, and the first time increment information.

[0083] Embodiments of the present disclosure also provide a first node or a second node or a third node or a first network node or a first user equipment in a wireless communication system, including:

[0084] a transceiver for transmitting and receiving signals; and

[0085] a controller coupled with the transceiver and configured to perform the method as in any preceding embodiment.

[0086] Figure 1 is an exemplary system architecture of System Architecture Evolution (SAE).

[0087] Figure 2 is a schematic diagram of a multi-hop sidelink relay network.

[0088] Figure 3 is a first flow chart according to the present disclosure.

[0089] Figure 4 is a second flow chart according to the present disclosure.

[0090] Figure 5 is a third flow chart according to the present disclosure.

[0091] Figure 6 is a fourth flow chart according to the present disclosure.

[0092] Figure 7 is a block diagram of a terminal or user equipment (UE) according to an embodiment of the disclosure.

[0093] Figure 8 is a block diagram of a base station (BS) according to an embodiment of the disclosure.

[0094] Figure 9 is a block diagram of a network entity according to an embodiment of the disclosure.

[0095] Hereinafter, embodiments of the disclosure will be described in detail with reference to the accompanying drawings.

[0096] In describing the embodiments, descriptions related to technical contents well-known in the art and not associated directly with the disclosure will be omitted. Such an omission of unnecessary descriptions is intended to prevent obscuring of the main idea of the disclosure and more clearly transfer the main idea.

[0097] For the same reason, in the accompanying drawings, some elements may be exaggerated, omitted, or schematically illustrated. Further, the size of each element does not completely reflect the actual size. In the drawings, identical or corresponding elements are provided with identical reference numerals or different reference numerals.

[0098] The advantages and features of the disclosure and ways to achieve them will be apparent by making reference to embodiments as described below in detail in conjunction with the accompanying drawings. However, the disclosure is not limited to the embodiments set forth below, but may be implemented in various different forms. The following embodiments are provided only to completely disclose the disclosure and inform those skilled in the art of the scope of the disclosure, and the disclosure is defined only by the scope of the appended claims. Throughout the specification, the same or like reference numerals designate the same or like elements. Furthermore, in describing the disclosure, a detailed description of known functions or constitution incorporated herein will be omitted in the case that it is determined that the description may make the subject matter of the disclosure unnecessarily unclear. The terms which will be described below are terms defined in consideration of the functions in the disclosure, and may be different according to users, intentions of the operators, or customs. Therefore, the definitions of the terms should be made based on the contents throughout the specification.

[0099] Herein, it will be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, may be performed based on computer program instructions. These computer program instructions may be loaded collectively onto at least one processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which perform through any one of, or in any combination of, the at least one processor of the computer or other programmable data processing apparatus, create means for performing the functions specified in the flowchart block(s). These computer program instructions may also be stored in a non-transitory computer usable or computer-readable memory that may direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer usable or computer-readable memory produce an article of manufacture including instruction means that perform the function specified in the flowchart block(s). The 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 data processing apparatus to produce a computer executed process such that the instructions that perform on the computer or other programmable data processing apparatus provide steps for executing the functions specified in the flowchart block(s).

[0100] Further, each block may represent a module, segment, or portion of code, which includes one or more executable instructions for executing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of the order. For example, two blocks(or functions) shown in succession may in fact be performed substantially concurrently or the blocks may sometimes be performed in the reverse order, depending upon the functionality involved.

[0101] As used in embodiments of the disclosure, a “~unit” may refer to a software element or a hardware element, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), which performs a predetermined function. However, the term including the word “~unit” does not always have a meaning limited to software or hardware. The “~unit” may be constructed either to be stored in an addressable storage medium or to execute one or more processors. Therefore, the “~unit” includes, for example, software elements, object-oriented software elements, components such as class elements and task elements, processes, functions, properties, procedures, sub-routines, segments of a program code, drivers, firmware, micro-codes, circuits, data, database, data structures, tables, arrays, and parameters. The components and functions provided by the “~unit” may be either combined into a smaller number of components and a “~unit,” or divided into additional components and a “~unit.” Moreover, the components and “~units” may be implemented to reproduce one or more central processing units (CPUs) within a device or a security multimedia card. Further, in the embodiments, the “~unit” may include one or more processors.

[0102] It should be appreciated that the blocks in each flowchart and combinations of the flowcharts may be performed by one or more computer programs which include instructions. The entirety of the one or more computer programs may be stored in a single memory device or the one or more computer programs may be divided with different portions stored in different multiple memory devices.

[0103] Any of the functions or operations described herein can be processed by one processor or a combination of processors. The one processor or the combination of processors is circuitry performing processing and includes circuitry like an application processor (AP, e.g. a CPU), a communication processor (CP, e.g., a modem), a graphics processing unit (GPU), a neural processing unit (NPU) (e.g., an artificial intelligence (AI) chip), a Wi-Fi chip, a Bluetooth® chip, a global positioning system (GPS) chip, a near field communication (NFC) chip, connectivity chips, a sensor controller, a touch controller, a finger-print sensor controller, a display driver integrated circuit (IC), an audio CODEC chip, a universal serial bus (USB) controller, a camera controller, an image processing IC, a microprocessor unit (MPU), a system on chip (SoC), an IC, or the like.

[0104] It will be appreciated that various embodiments of the disclosure according to the claims and description in the specification can be realized in the form of hardware, software or a combination of hardware and software.

[0105] Any such software may be stored in non-transitory computer readable storage media. The non-transitory computer readable storage media store one or more computer programs (software modules), the one or more computer programs include computer-executable instructions that, when executed by one or more processors of an electronic device individually or collectively, cause the electronic device to perform a method of the disclosure.

[0106] Any such software may be stored in the form of volatile or non-volatile storage such as, for example, a storage device like read only memory (ROM), whether erasable or rewritable or not, or in the form of memory such as, for example, random access memory (RAM), memory chips, device or integrated circuits or on an optically or magnetically readable medium such as, for example, a compact disk (CD), digital versatile disc (DVD), magnetic disk or magnetic tape or the like. It will be appreciated that the storage devices and storage media are various embodiments of non-transitory machine-readable storage that are suitable for storing a computer program or computer programs comprising instructions that, when executed, implement various embodiments of the disclosure. Accordingly, various embodiments of the present disclosure may provide a program comprising code for implementing apparatus or a method as claimed in any one of the claims of this specification and a non-transitory machine-readable storage storing such a program.

[0107] Hereinafter, the determination of priority between A and B in the present disclosure may refer to various actions such as selecting the one having a higher priority based on a predefined priority rule and performing an operation corresponding thereto, or omitting or dropping an operation corresponding to the one having a lower priority.

[0108] Hereinafter, "A or B" as described in the present disclosure may be understood as "A and / or B," which may include A, or B, or both A and B.

[0109] In addition, "at least one of A, B, and C" as described in the present disclosure may be understood to include A, or B, or C, or any combination of A, B, and C.

[0110] In addition, "at least one of A, B, or C" as described in the present disclosure may be understood to include A, or B, or C, or any combination of A, B, and C.

[0111] Furthermore, "A / B" as described in the present disclosure may be understood as "A and / or B," which may include A, or B, or both A and B.

[0112] Furthermore, "A, B" as described in the present disclosure may be understood as "A and / or B," which may include A, or B, or both A and B.

[0113] Furthermore, "A and B" as described in the present disclosure may be understood as "A and / or B," which may include A, or B, or both A and B.

[0114] Furthermore, “if condition A and condition B are satisfied,” as described in the present disclosure, may not be limited to a case where both condition A and condition B are satisfied, but may be understood to include a case where either condition A or condition B is individually satisfied, both condition A and condition B are satisfied, or one or more additional conditions are satisfied in combination.

[0115] Furthermore, throughout this disclosure, ordinal terms such as "first," "second," "third," etc., (and similar qualifiers) are used merely to distinguish between different instances, occurrences, configurations, messages, stages, or aspects of elements, operations, or information as described herein. Unless the context clearly dictates otherwise, the use of such ordinal terms does not itself require that the elements, operations, or information distinguished by these terms be structurally different, numerically distinct, or substantively dissimilar. For example, a "first signal" and a "second signal" may refer to instances of the same signal transmitted at different times or containing the same core information despite minor variations, or they may refer to signals with different content or characteristics, depending on the specific context. Similarly, a "first value" and a "second value" may represent the same magnitude but measured or applied in different circumstances, or they may represent different magnitudes. The interpretation should be guided by the specific technical context, function, and relationship described in the relevant portion of the specification and claims.

[0116] Furthermore, the terms “first ~”, “second ~”, etc., as described in the present disclosure with respect to various elements (e.g., information, objects, operation, sequences, or the like), should not limit those elements. These terms may only be intended to distinguish one element from another, and may not be intended to indicate a specific order. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element.

[0117] Furthermore, even if “first ~” and “second ~” are described in the present disclosure, it may be understood that element(s) referred to by “first ~” and “second ~” may be the same or different. For example, in case of element(s) being information, first information and second information may both be same information and, in some cases, are separate and different information.

[0118] In addition, the terms “if ~” and “in case that ~” as used in the disclosure or claims may be interpreted to include the meanings of “when (or upon) ~,” “in response to ~,” “based on ~,” or “according to ~,” and may be used interchangeably with these expressions. In addition, expressions other than those exemplified herein may also be used, as long as they have substantially the same meaning and do not impair the technical features of the present disclosure.

[0119] For example, the physical layer signaling may be referred to as Layer 1 (L1) signaling and may include downlink control information (DCI). In addition, the higher layer signaling may include a medium access control (MAC) control message, a radio resource control (RRC) signaling message, a non-access stratum (NAS) signaling message, or an application layer message. The RRC signaling message may be referred to as L3 (layer 3) signaling. It should be noted, however, that the higher layer signaling is not limited to the aforementioned examples.

[0120] In addition, the term "not perform" as used in the present disclosure or claims may, in context, be understood to mean that the corresponding step is omitted or skipped. Such a term may be replaced with other terms having the same or substantially equivalent meaning.

[0121] In addition, "transmitting a message including A and B" as described in the present disclosure, may be understood as encompassing both (i) transmitting A and B in a single message, and (ii) transmitting A and B separately via multiple messages (e.g., transmitting a first message including A and a second message including B). This interpretation may also apply to messages that include two or more items (e.g., A, B, C), transmitted either together or separately.

[0122] In addition, "transmitting a message including A and transmitting a message including B" may also be interpreted as transmitting a message including A and B in a single message.

[0123] In the specific embodiments of the present disclosure described below, terms or components included in the disclosure may be expressed in singular or plural form depending on the specific embodiments presented. However, such singular or plural expressions are selected appropriately for convenience of description, and the present disclosure is not limited to a singular or plural number of components. A component expressed in the plural form may be implemented as a single component, and a component expressed in the singular form may be implemented as multiple components.

[0124] The drawings or flowcharts described below illustrate exemplary methods that may be implemented according to the principles of the present disclosure, and various modifications may be made to the methods illustrated in the flowcharts of the present disclosure. For example, although illustrated as a series of steps, various steps in each drawing or flowchart may overlap, occur in parallel, occur in a different order, or be repeated. In other examples, any step may be omitted or replaced with another step.

[0125] The methods and apparatuses proposed in the embodiments of the present disclosure are not limited to each embodiment individually, but may also be applied in combination of all or some of the embodiments proposed in the disclosure. Therefore, the embodiments of the present disclosure may be modified and applied without significantly departing from the scope of the present disclosure, as would be understood by those skilled in the art.

[0126] In this case, even if certain wordings are described differently across embodiments, they may be used interchangeably or in substitution or in combination if their underlying concepts are equivalent. For example, for the same or equivalent concept, even if one embodiment uses the expression "A" and another embodiment uses the expression "B", such expressions may be understood interchangeably, in substitution, or in combination.

[0127] The terms used in the following description to refer to access nodes, network entities, messages, interfaces between network entities, various types of identification information, and the like, are provided merely for the convenience of explanation by way of example. Therefore, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may also be used. Such terms may also be interchangeable with terms defined in any 3rd generation partnership project　(3GPP) technical specifications (TS) where appropriate.

[0128] Hereinafter, a base station is an entity that allocates resources to terminals, and may be at least one of a gNode B, an eNode B, a Node B, a base station (BS), a wireless access unit, a BS controller, or a node on a network.

[0129] Furthermore, the base station of the present disclosure may include a split architecture comprising a central unit (CU) and a distributed unit (DU). In this structure, the CU is configured to process the higher layers of the control and user planes, while the DU is configured to process lower-layer radio resource functions. The embodiments of the present disclosure may be equally applicable to 5G base station architectures in which such CU and DU functional splits are implemented.

[0130] A terminal may include a UE, a mobile station (MS), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing communication functions.

[0131] In the disclosure, a downlink (DL) refers to a radio link through which a BS transmits a signal to a UE, and an uplink (UL) refers to a radio link through which a UE transmits a signal to a BS.

[0132] Furthermore, hereinafter, 5th generation (5G) mobile communication technologies (e.g., 5G new radio (NR)), 6th generation (6G) mobile communication technologies may be described by way of example, but the embodiments of the present disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, newly evolved mobile communication systems developed after 5G and 6G may be included. Furthermore, based on determinations by those skilled in the art, the embodiments of the present disclosure may also be applied to other communication systems (e.g., Wi-Fi systems) through some modifications without significantly departing from the scope of the present disclosure

[0133] In the following description, the terms physical channel and signal may be used interchangeably with data or control signal. For example, the term physical downlink shared channel (PDSCH) refers to a physical channel through which data is transmitted, but the term PDSCH may also be used to refer to the data itself. That is, in the present disclosure, the expression "transmit a physical channel" may be interpreted as being equivalent to the expression "transmit data or a signal via a physical channel."

[0134] Hereinafter, in the context of the present disclosure, higher layer signaling may refer to signaling corresponding to at least one or any combination of the following: master information block (MIB), system information block (SIB) or SIB M (M = 1, 2, ...), radio resource control (RRC), or medium access control (MAC) control element (CE), or a non-access stratum (NAS) signaling message, or an application layer message. The RRC signaling message may be referred to as L3 (layer 3) signaling.

[0135] In addition, L1 signaling may refer to signaling corresponding to at least one or any combination of signaling techniques using the at least one or any combination of the following physical layer channels or signaling: physical downlink control channel (PDCCH), downlink control information (DCI), user equipment (UE)-specific DCI, group-common DCI, common DCI, scheduling DCI (e.g., DCI used for scheduling downlink or uplink data), non-scheduling DCI (e.g., DCI not used for scheduling downlink or uplink data) physical uplink control channel (PUCCH), or uplink control information (UCI). The L1 signaling message may be referred to as a physical layer signaling.

[0136] Hereinafter, the expression that information is configured by the BS, as used in the present disclosure or claims, may, in context, be understood to mean that the terminal receives the corresponding information from the BS via a physical layer signaling or a higher layer signaling. Such an expression may be replaced with other terms having the same or substantially equivalent meaning.

[0137] Hereinafter, the operational principle of the present disclosure will be described in detail with reference to the accompanying drawings.

[0138] In order to meet an increasing demand for wireless data communication services since a deployment of 4G communication system, efforts have been made to develop an improved 5G or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called “beyond 4G network” or “post LTE system”.

[0139] Wireless communication is one of the most successful innovations in modern history. Recently, a number of subscribers of wireless communication services has exceeded 5 billion, and it continues growing rapidly. With the increasing popularity of smart phones and other mobile data devices (such as tablet computers, notebook computers, netbooks, e-book readers and machine-type devices) in consumers and enterprises, a demand for wireless data services is growing rapidly. In order to meet rapid growth of mobile data services and support new applications and deployments, it is very important to improve efficiency and coverage of wireless interfaces.

[0140] In the wireless network, due to limitations in cell coverage or cell capacity, user equipment directly connected to the base station cannot obtain better services, and users far away from the base station cannot connect to the network. To solve this problem, researchers have proposed multi-hop user equipment relay technology, which allows one user equipment to connect to a base station through one or more relay user equipment. One example of this technique is a multi-hop sidelink relay technique. Since user equipment is connected to the network through multiple nodes, how to establish and maintain this connection efficiently and quickly is an urgent problem to be solved.

[0141] Figures discussed below and various embodiments for describing the principles of the present disclosure in this patent document are only for illustration and should not be interpreted as limiting the scope of the disclosure in any way. Those skilled in the art will understand that the principles of the present disclosure can be implemented in any suitably arranged system or device.

[0142] Fig. 1 is an exemplary system architecture 200 according to various embodiments of the present disclosure. Other embodiments of the system architecture 200 can be used without departing from the scope of the present disclosure.

[0143] User equipment (UE) 201 is a terminal device for receiving data. A next generation radio access network (NG-RAN) 202 is a radio access network, which includes a base station (a gNB or an eNB connected to 5G core network 5GC, and the eNB connected to the 5GC is also called ng-gNB) that provides UE with interfaces to access the radio network. An access control and mobility management function entity (AMF) 203 is responsible for managing mobility context and security information of the UE. A user plane function entity (UPF) 204 mainly provides functions of user plane. A session management function entity SMF 205 is responsible for session management. A data network (DN) 206 includes, for example, services of operators, access of Internet and service of third parties.

[0144] The exemplary embodiments of the present disclosure are further described below in conjunction with the accompanying drawings.

[0145] The text and drawings of this disclosure are provided as examples only to assist in understanding the present disclosure. They should not be construed as limiting the scope of the disclosure in any way. Although certain embodiments and examples have been provided, it will be apparent to those skilled in the art, based upon this disclosure, that changes can be made to the embodiments and examples shown without departing from the scope of the disclosure.

[0146] Before introducing the specific content, some assumptions and some definitions of this disclosure are given below.

[0147] * In this disclosure, user, user device, user device, user device device are equivalent.

[0148] * The "first" and "second" included in the message name of the disclosure are only used to distinguish one message from another, and do not represent the execution or transmission order.

[0149] * Detailed description of steps irrelevant to the disclosure is omitted in the present invention.

[0150] * In the disclosure, the steps in each process can be executed in combination with each other or independently. The execution steps of each process are only examples, and other possible execution steps and / or orders are not excluded.

[0151] * In the disclosure, the base station may be a 6G base station, a 5G base station (such as gNB and ng-eNB), a 4G base station (such as eNB), RAN nodes or other types of access nodes.

[0152] Nodes involved in this disclosure include:

[0153] First user equipment: user equipment (UE), in one example, the user equipment is a remote user equipment (remote UE), which accesses the network through one or more relay nodes;

[0154] First relay node: a relay node, which can be a user equipment, a node with the function of a base station, or a node with the function of a distribution unit of a base station. The node is directly connected to the first user equipment (not directly connected to the base station), and provides the first user equipment with a connection function to the third relay node. There is at least one second relay node between the first user equipment (or the first relay node) and the third relay node. When the first relay node is a user equipment, the link between the first user equipment and the first relay node is sidelink or PC5 link. In one example, the node is the first relay user equipment (first relay UE).

[0155] Second relay node: a relay node, which can be a user equipment, a node with the function of a base station, or a node with the function of a distribution unit of a base station. This node is a node that provides the first user equipment with a connection function to the third relay node. It is not directly connected to the base station. There is at least one second relay node between the first relay node (or the first user equipment) and the third relay node. In one example, the node is an intermediate relay node, or an intermediate relay UE. When there are multiple intermediate relay nodes, the two adjacent intermediate relay nodes are the second relay node and the fourth relay node, respectively

[0156] Third relay node: a relay node, which can be a user equipment, a node with the function of a base station, or a node with the function of a distribution unit of a base station. This node is a node that provides the first user equipment with a connection function to the network, and is directly connected to the base station, and the first user equipment accesses the base station through the third relay node. There may also be one or more nodes (such as the above-mentioned second relay node, fourth relay node) between the third relay node and the first user equipment (or first relay node). In one example, the node is the last relay node, or last relay user equipment (last relay UE);

[0157] First network node: a base station. In one example, the base station is a node that directly performs data transmission with the third relay node.

[0158] Figure 2 is a schematic diagram of a multi-hop sidelink relay network.

[0159] As shown in Figure 2, a multi-hop sidelink relay network includes a first network node, a first / second / third relay node, and a first user equipment.

[0160] The above-mentioned first network node can be one of the following types (other types that can be used for user terminal access are not excluded):

[0161] * Long Term Evolution (LTE) base station;

[0162] * 5G base station;

[0163] * 6G base station

[0164] * RAN node;

[0165] * Non-Terrestrial Networks (NTN) base station;

[0166] * High Altitude Platform Station (HAPS) base station;

[0167] * Drone base station; and

[0168] * WIFI access point.

[0169] In a multi-hop relay network (such as a multi-hop sidelink relay network), the remote user equipment needs to transmit data with the base station through one or more intermediate relay nodes and one last relay node. In this network, the transmission path between the remote user equipment and the base station may be interrupted due to a change in the link of the relay node. Therefore, an urgent problem to be solved in multi-hop relay networks is how to maintain the connection between the remote user equipment and the base station and quickly resume the transmission path when problems occur in the transmission path. The transmission path may be interrupted for at least one of the following reasons:

[0170] * a change in a link of the third relay node (last relay node), such as a radio link failure, cell reselection, handover, a connection failure (such as a connection setup failure, a connection resume failure), a connection reestablishment failure, and an upper layer request to a release sidelink (such as a PC5 link).

[0171] * a change in a link of the second relay node (intermediate relay node), such as a sidelink failure (e.g., a PC5 failure), relay node reselection, a radio link failure, cell reselection, handover, a connection failure (e.g., a connection setup failure, a connection resume failure), a connection reestablishment failure, an upper layer request to a release sidelink (such as a PC5 link), other connected relay nodes indicating a change of a connection state.

[0172] * a change in a link of the first user equipment (a remote user equipment), such as a sidelink failure (such as a PC5 failure), relay node reselection, a radio link failure, cell reselection, handover, a connection failure (such as a connection setup failure, a connection resume failure), a connection reestablishment failure, an upper layer request to a release sidelink (such as a PC5 link), other connected relay nodes indicating a change of a connection state.

[0173] Figure 3 is a first flow chart according to the present disclosure.

[0174] As shown in Figure 3, when a link of a node changes, a first notification message will be transmitted to other nodes to notify other nodes of the change in its state. Alternatively, when a node wants to establish a connection with other nodes (such as establishing a sidelink or a PC5 link), the node needs to transmit a first notification message so that other nodes can discover the node, and other nodes can then determine whether to establish a connection with the node. Specifically, the process includes:

[0175] Step 1-0: The first network node transmits a first configuration message related to a multi-hop sidelink relay network serving a first user equipment to a first node.

[0176] Step 1-1: The first node transmits a first notification message to the second node. This message is used to notify the information on a link where the first node or the second node is located, and can also be used to notify the information on a link on the transmission path where the first node or the second node is located, and can also be used to inform information related to the first node. The first node and the second node may be any two of the first relay node, the second relay node, the third relay node, the fourth relay node and the first user equipment, such as the third relay node and the second relay node, the second relay node and the fourth relay node, the second relay node and the first relay node, the first relay node and the first user equipment, the third relay node and the first user equipment, the third relay node and the first relay node. The beneficial effect of this message is to help the second node learn a change in a link of the first node or information on the first node. Furthermore, the second node can change the connected link in a timely manner and reduce the interruption in data transmission of user equipment, or determine whether to connect with the first node, so as to ensure the data transmission of the user equipment. The message includes at least one of the following information:

[0177] * First type indication information, which is used to indicate a type or capability of the first node, and further helps the second node to determine whether it can establish a connection with the first node and perform data transmission of the user equipment. The information has the beneficial effects of helping the second node to determine the type or capability of the first node, and then establishing a connection with the first node according to the capability of the first node, and helping the transmission of the user equipment, thus improving the efficiency of data transmission. The information includes at least one of the following information:

[0178] * indication information on a device type, which indicates the type of the first node, and the type indicated by the information may be at least one of the following types (or a combination of at least two types):

[0179] - a remote user equipment. The type indicates that the first node cannot provide other nodes with a link to access the network, or other nodes cannot access the network through the first node.

[0180] - a first relay user equipment. The type indicates that the first node allows the access of the user equipment, but the user equipment accessing the first node cannot provide other user equipment with a link to access the network.

[0181] - an intermediate relay node. The type indicates that the first node can provide other nodes with a link to access the network, and other nodes also have child nodes.

[0182] - a last relay node. The type indicates that the first node has a link with the network (base station), and other nodes can access the network through the first node, and the other nodes can have child nodes.

[0183] * supported hop count information, which indicates the hop count supported by the first node. This information can help the second node decide whether to establish a connection with the first node, and then access the network through the first node or provide a link for the first node to access the network. The information includes at least one of the following information:

[0184] - a supported downlink hop count, which indicates the hop count in the downlink multi-hop path supported by the first node, that is, the hop count included in the multi-hop transmission path accessing the first node. When the second node receives this information, it will determine whether it can establish a connection with the first node according to this information and the hop count in the path where the second node is located. If the hop count in the path where the second node is located causes the downlink hop count supported by the first node to be exceeded, the second node will not establish a connection with the first node. In one example, if the first node is the above-mentioned remote user equipment, the information can be set to 0, which means that the first node cannot provide other nodes with a link to access the network. In another example, if the first node is the first relay user equipment, the information can be set to 1, which means that the first node allows the second node to access the network through the first node, but the second node can no longer provide other nodes with a link to access the network. In another example, the information may be determined by the first node according to the downlink hop count supported by other nodes accessed by the first node. If the downlink hop count supported by other nodes accessed by the first node is 5, the first node may set the information to 4.

[0185] - a supported uplink hop count, which indicates the hop count of the uplink multi-hop path supported by the first node, that is, the hop count included in the multi-hop transmission path accessed by the first node. If the first node accesses the network through the second node, the hop count included in the multi-hop path of the network accessed by the first node should not exceed the hop count indicated by this information. After receiving the information, the second node will determine whether it can provide the first node with a transmission path to access the network according to the information and the hop count of the multi-hop transmission path of the access network where the second node is located.

[0186] * hop count information of a transmission path, which indicates the hop count of the multi-hop transmission path where the first node is located (which is the transmission path between the first node and the network). After receiving this information, the second node can determine whether it establishes a connection with the first node, and then access the network through the first node.

[0187] ■ first indication information, which is used to indicate a link state of the node, or type information of the link state. In one implementation, this information may be named indication type information. The node related to such information may be any one of the first relay node or the second relay node or the third relay node or the fourth relay node. In one example, the information is generated by the transmitting node (such as the first node) according to its own state. In another example, the information may be obtained by the transmitting node (such as the first node) from other nodes. For example, the message (such as the above-mentioned first notification message) transmitted by the other node to the transmitting node (such as the first node) includes this indication information. In another example, it may also be generated by the transmitting node (such as the first node) based on information obtained from other nodes. The beneficial effect of this information is to provide the receiving node (such as the second node) with information on the link connection state, so that the link of the receiving node (such as the second node) can be adjusted according to the state, reducing the interruption in data transmission of the user equipment. The information includes at least one of the following information:

[0188] * relay node reselection indication information, which indicates that the node performs the relay node reselection. Further, this information can also be used to indicate the node that performs relay node reselection, such as third relay node reselection indication information (such as last relay UE reselection), second relay node reselection indication information (such as intermediate relay UE reselection), first relay node reselection indication information (such as first relay UE reselection).

[0189] * relay node selection indication information, which indicates that the node performs the relay node selection. Further, this information can also be used to indicate the node that performs relay node selection, such as the third relay node selection indication information (such as last relay UE selection), the second relay node selection indication information (such as intermediate relay UE selection), first relay node selection indication information (such as first relay UE selection).

[0190] * reestablishment indication information, which indicates that the node has completed the reestablishment, or indicates that the node is performing the reestablishment, or has started the reestablishment. Further, this information can also be used to indicate the node that performs the reestablishment, such as third relay node reestablishment indication information (such as last relay UE reestablishment), second relay node reestablishment indication information (such as intermediate relay UE reestablishment), first relay node reestablishment indication information (such as first relay UE reestablishment).

[0191] * reestablishment failure indication information, which indicates that the reestablishment of the node has failed. Furthermore, this information can also be used to indicate the node that fails to perform the reestablishment, such as the third relay node reestablishment failure indication information (such as the last relay UE reestablishment failure), second relay node reestablishment failure indication information (such as intermediate relay UE reestablishment failure), first relay node reestablishment failure indication information (such as first relay UE reestablishment failure).

[0192] * air interface radio link failure indication information, such as Uu-radio link failure (Uu-RLF). This information indicates that the node occurs a radio link failure. Furthermore, this information can also be used to indicate that the node which occurs an air interface radio link failure. For example, third relay node air interface radio link failure indication information (such as last relay UE Uu RLF), second relay node air interface radio link failure indication information (such as intermediate relay UE Uu RLF), first relay node air interface radio link failure indication information (such as first relay UE Uu RLF).

[0193] * handover indication information, which indicates that the node performs a handover or performs the reconfiguration with synchronization. Furthermore, this information can also be used to indicate the node which performs a handover, such as the third relay node handover indication information (such as last relay UE Handover), second relay node handover indication information (such as intermediate relay UE handover), first relay node handover indication information (such as first relay UE handover).

[0194] * cell reselection indication information, which indicates that the node performs the cell reselection. Further, this information can also be used to indicate the node for the cell reselection, such as the third relay node cell reselection indication information (such as last relay UE cell reselection), second relay node cell reselection indication information (such as intermediate relay UE cell reselection), first relay node cell reselection indication information (such as first relay UE cell reselection).

[0195] * cell selection indication information, which indicates that the node performs the cell selection. Further, this information can also be used to indicate the node for the cell selection, such as the third relay node cell selection indication information (such as last relay UE cell selection), second relay node cell selection indication information (such as intermediate relay UE cell selection), first relay node cell selection indication information (such as first relay UE cell selection).

[0196] * connection failure indication information, or Radio Resource Control (RRC) failure, which indicates that the connection failure of the node has occurred, such as a connection setup failure and a connection resume failure. Furthermore, this information can also be used to indicate a nodes where the connection failure has occurred. For example, the third relay node connection failure indication information (such as the last relay UE RRC failure), the second relay node connection failure indication information (such as the intermediate relay UE RRC failure), the first relay node connection failure indication information (such as the first relay UE RRC failure).

[0197] * sidelink failure indication information, which indicates that a radio link failure occurred in the sidelink (or PC5 link) of the node. Furthermore, this information can also be used to indicate the node where the sidelink failed, such as the third relay node sidelink failure indication information (such as last relay UE PC5 RLF), second relay node sidelink failure indication information (such as intermediate relay UE sidelink failure), first relay node sidelink failure indication information (such as first relay UE PC5 RLF).

[0198] * sidelink release indication information, which indicates that the sidelink (or PC5 link) of the node is released. Further, this information can also be used to indicate the node where the sidelink is released, such as the third relay node sidelink release indication information (such as last relay UE PC5 release), second relay node sidelink release indication information (such as intermediate relay UE sidelink release), first relay node sidelink release indication information (such as first relay UE PC5 release).

[0199] ■ first path interruption indication information, which is used to indicate transmission path failure or interruption or unavailable (such as multi-hop relay transmission path failure / interruption / unavailable). In one example, the transmission path is a path between the third relay node and the first relay node. In another example, the transmission path is a transmission path between the first network node and the first user equipment node. In another example, the transmission path is a transmission path between the third relay node and the first user equipment. The reason for path failure / interruption / unavailable may be that one or more links on the transmission path (such as the link between two intermediate relay nodes, the link between the intermediate relay node and the last relay node, the link between the intermediate relay node and the first user equipment, the link between the first relay node and the first user equipment) has occurred at least one of the following situations: relay node reselection, relay node selection, reestablishment, a reestablishment failure, air interface radio link failure, handover, cell reselection, cell selection, a connection failure (or a RRC failure), a sidelink failure, a sidelink release. In order to indicate the reason for the failure or interruption of the transmission path, this information can also be used in combination with the above-mentioned "first indication information", that is, the above-mentioned "first indication information" is used to indicate the reason for the failure / interruption / unavailable of the transmission path. Further, the information may also include information related to the path, such as the identification information of the path (path ID), the information of the destination node of the path (such as the identification information of the first user equipment, the identification of the first relay node, the identification of the third relay node, the identification of the second relay node). The beneficial effect of this information is to provide state information on the transmission path where the receiving node (such as the second node) is located, detect the interruption of the path in time, and adjust the connected link to reduce the interruption of user data.

[0200] ■ a notification message container containing notification messages transmitted by other relay nodes. For the content of the notification message, please refer to the above-mentioned “first notification message”. Further, in order to indicate the transmitter of the message contained in the container, identification information of the relay node, such as local ID, may also be included. The beneficial effect of this information is to notify the receiving node (such as the second node) or a node different from the receiving node (such as the second node) of the state information of other nodes, facilitating the receiving node (such as the second node) or a node different from the receiving node (such as the second node) to make link changes and reduce the interruption in data transmission.

[0201] ■ first assistant information for assisting in learning a link change. In one embodiment, the information is provided for the above-mentioned "first indication information" or "first path interruption indication information". The beneficial effect of this information is to help the receiving node (such as the second node) obtain accurate information on the transmission path, facilitate the receiving node (such as the second node) to adjust the transmission path, and reduce the interruption in data transmission. The information includes at least one of the following:

[0202] * identification information of a cell. Further, the cell indicated by the information may be at least one of the following cells (if the information indicates multiple cells, the information may include identification information of multiple cells):

[0203] - a cell selected during a cell selection process.

[0204] - a cell selected during a cell reselection process.

[0205] - a cell selected for reestablishment, which in one example is a cell that starts the reestablishment, in another example is a cell where the re-establishment is success.

[0206] - a target cell for handover.

[0207] - a cell serving a relay node accessed by a transmitting node (such as the first node).

[0208] - a serving cell of a path.

[0209] The above-mentioned cell is a cell serving the transmitting node (such as the first node), or a cell serving the relay node accessed by the transmitting node (such as the first node), or a cell serving a relay node on the transmission path where the transmitting node (such as the first node) is located.

[0210] * identification information of a node, such as local identification (Local ID). Further, the information indicates a node on the transmission path, and the node indicated by the information can be at least one of the following nodes (if the information indicates multiple nodes, the information can contain identification information of multiple nodes):

[0211] - a node selected during relay node reselection. Further, it may also include the identification of the node that performs relay node reselection. In one example, the node is the node reselected by the transmitting node (such as the first node). In another example, the node is the node reselected by a node on the transmission path where the transmitting node (such as the first node) is located.

[0212] - a node selected during relay node selection. Further, it may also include the identification of the node that performs relay node selection. In one example, the node is the node selected by the transmitting node (such as the first node). In another example, the node is the node selected by a node on the transmission path where the transmitting node (such as the first node) is located.

[0213] - a node where a sidelink failure occurs. Further, the information may also include the identification of the two nodes serving the failed sidelink.

[0214] * identification information of a link, such as link ID. This information indicates the link on the transmission path (such as the link between two nodes), and the link identified by the information can be at least one of the following links (if this information indicates multiple links, this information may include identification information of multiple links):

[0215] - a link between the first user equipment and the first relay node.

[0216] - a link between two intermediate relay nodes.

[0217] - a link between the second relay node and the third relay node.

[0218] - a link between the third relay node and the base station.

[0219] * indication information of a link type, which indicates the type of link on the transmission path, which may be an interrupted or failed or unavailable link, may be used to indicate at least one of the following types (if the information indicates multiple link types, This information may contain an indication of link types for multiple links):

[0220] - a link between the first user equipment and the first relay node.

[0221] - a link between two intermediate relay nodes.

[0222] - a link between the second relay node and the third relay node.

[0223] - a link between the third relay node and the base station.

[0224] The above-mentioned first notification message can be a sidelink notification message, NotificationMessageSidelink, it can also be a Discovery message or other messages.

[0225] Before the above step 1-1, it may also include:

[0226] Step 1-0: The first network node transmits a first configuration message to a relay node, such as the third relay node or the second relay node or the first relay node. The message includes at least one of the following information:

[0227] ■ path configuration information indicating one or more paths served by the relay node. The beneficial effect of this information is to provide information on the path where the relay node is located, facilitate data transmission, and improve the efficiency of data transmission. The information includes at least one of the following:

[0228] * identification information of user equipment, which indicates the identification information of the user equipment served by the relay node, such as local ID. In one example, the user equipment is directly connected to the relay node. In another example, the user equipment is connected to the relay node through other relay nodes; Further, the information may include identification information of one or more user equipment.

[0229] * path identification information indicating a path served by the relay node.

[0230] ■ first notification configuration information used to help the relay node determine whether to transmit the above-mentioned “first notification message”. The beneficial effect of this information is to configure the relay node to transmit the “first notification message” and reduce unnecessary signaling overhead. The information includes at least one of the following:

[0231] * time indication information used to indicate a (maximum) time that the relay node needs to wait before transmitting the “first notification message”, or a (maximum) time that performs the relevant behaviour. The relevant behaviour may be at least one of: relay node reselection or selection, reestablishment, handover, cell selection or reselection, connection setup, connection resume, waiting for a request of the first user equipment (such as a reestablishment request, a connection setup request, or a data packet from a special channel (such as a Radio link control channel, RLC channel)). In one example, the relay node transmits the “first notification message” after the time indicated by the information ends (or the timer set according to the time indication information expires). In another example, the relay node does not complete the above-mentioned “relevant behaviour” within the time indicated by the information (or after the timer set according to the time indication information expires), and the relay node transmits the above-mentioned “first notification message”.

[0232] * relay node behavior indication information used to indicate a behaviour which the relay node is allowed to perform or needs to perform. The behavior may be at least one of the following behaviors: relay node reselection, relay node selection, cell selection, cell reselection, reestablishment, connection setup, connection resume, releasing a link (such as releasing a sidelink or a PC5 link), entering an IDLE state or an INACTIVE state. In one example, the behavior may be a behavior that the relay node is allowed to perform or a behavior that needs to be performed before transmitting the above-mentioned “first notification message”. Therefore, the relay node will determine the behavior to perform based on this information, and further, the “first notification message” is only transmitted when the above-mentioned “a condition that triggers the first node to transmit the above-mentioned first notification message” is met. In another example, the behavior may be a behavior that the relay node is allowed to perform or a behavior that needs to perform after transmitting the above-mentioned “first notification message”.

[0233] ■ state configuration indication information, which is used to indicate the connection state of the relay node, such as connected state, idle state or inactive state, or used to indicate condition information that the relay node is in a certain state. The relay node may determine the state (e.g. connected state, idle state or inactive state) in which it is allowed based on this information. Further, the state indicated by the information is the state that the relay node is in when serving the multi-hop relay network. In one embodiment, this information is transmitted to the relay node via a system information. Based on this information, the relay node can determine whether it is allowed to serve the multi-hop relay network when it is in an idle state or inactive state, and further, the relay node can determine the condition under which it is in the idle state or inactive state based on this information, to determine whether it can continue to remain in the idle state or inactive state. The beneficial effect of this information is to indicate the state of the relay node serving the multi-hop network, reducing signaling overhead and energy consumption of the relay node. The information includes at least one of the following:

[0234] * state indication information. The state indicated by the information is one of a connected state, an idle state, or an inactive state. In one example, the information indicates the state in which the relay node is allowed, and further indicates the state in which the relay node is when serving the multi-hop relay network.

[0235] * cell identification information, which indicates the cell in which the relay node is located when it is in a specific state (such as connected state, idle state or inactive state, or the state indicated by the above "state indication information")

[0236] * state condition indication information, which indicates the condition of the state in which the relay node is (such as connected state, idle state or inactive state). When the relay node is in an idle state or inactive state, if the condition indicated by the information cannot be met, the relay node can start a connection setup process or a connection resume process with the first network node. Furthermore, the relay node can also transmit the following “first assistant message” to the first network node. The information includes at least one of the following:

[0237] - first time indication information, which indicates the time length of the state in which the relay node is in. After the time indicated by the indication information, the relay node needs to enter the connected state.

[0238] - first measurement result threshold indication information, which indicates the threshold of the measurement result of the state in which the relay node is, and the measurement result may be, for example, Reference Signal Receiving Power (RSRP), Reference Signal Receiving Quality (RSRQ), etc. The measurement result can be the measurement result of the air interface or the measurement result of the sidelink. Furthermore, the measurement result can be a measurement result on a link between the relay node and a node (parent node) in the uplink direction, or a measurement result on a link between the relay node and a node (child node) in the downlink direction. In one implementation, when the measurement result is greater than (or less than) the threshold indicated by the information, the relay node can perform data transmission (or serve multi-hop relay network) in a specific state (such as connected state, idle state or inactive state), otherwise, the relay node needs to enter the connected state.

[0239] - first data amount indication information, which indicates the threshold of the data transmission amount in the state in which the relay node is, and the data transmission amount can be the transmitted data amount of all user equipment, or the transmitted data amount of the specific user equipment (i.e., the indication information also includes the identification information of the specific user equipment). It may also be the transmitted data amount of a specific bearer of a specific user equipment (that is, the indication information also includes the identification information of the specific user equipment and the identification information of the bearer). In one implementation, when the data amount is greater than (or less than) the threshold indicated by the information, the relay node can perform data transmission (or serve multi-hop relay network) in a specific state (such as connected state, idle state or inactive state), otherwise, the relay node needs to enter the connected state.

[0240] ■ data transmission configuration information used to configure a relay node to perform data transmission. In one example, the data transmission is performed when the relay node is in the connected state (such as RRC connected state). In another example, the data transmission is performed when the relay node is in the idle state (such as RRC idle state,) or inactive state (such as RRC inactive state). Further, the data transmission is performed in the process of remote user equipment accessing the network. In one example, this information may be transmitted to the relay node when the relay node is released into an idle or inactive state (such as transmitted to the relay node via an RRCRelease message), so that the relay node can continue to perform the data transmission according to this information. The beneficial effect of this information is to configure the relay node's data transmission, reducing signaling overhead and energy consumption. The information includes at least one of the following:

[0241] * Second identification information of user equipment, which contains one or more identification information. In one example, this information indicates the identification information of the user equipment served by the relay node, such as local ID (local ID). The user equipment served by the relay node may be directly connected to the relay node or connected to the relay node through other relay nodes. In one embodiment, the information is (in advance) allocated by the first network node to the user equipment accessing the relay node (such as the third relay node or the second relay node or the first relay node), for example, the information is transmitted to the relay node when the first network node releases the relay node to an idle state or an inactive state. After receiving this information, the relay node will allocate one identification information among the information to other node after receiving the message transmitted by the other node. In one example, if the message transmitted by the other node to the relay node is transmitted through a specific channel (such as RLC channel on the sidelink, RLC channel on the sidelink for carrying SRB0, or RLC channel 0 on the sidelink, etc.), the relay node will allocate one identification information among the information to the other node.

[0242] * configuration retention indication information used to indicate a configuration that the relay node needs to retain, and the configuration that needs to retain may be at least one of the following configuration information (or the configuration retention indication information includes at least one of the following configuration information, that is, the information indicates the configuration of the relay node for data transmission.):

[0243] - configuration information of data mapping, which indicates the mapping of data transmitted by the relay node. The information may include at least one of the following information: identification information of a bearer, identification information of first user equipment, identification information of an (uplink / downlink) egress channel (such as PC5 RLC channel, air interface RLC channel), identification information of an (uplink / downlink) ingress channel (such as PC5 RLC channel, air interface RLC channel), etc. In one example, the configuration is a configuration of a Sidelink Relay Adaptation Protocol layer (SRAP). In one embodiment, the configuration information of the data mapping is used to transmit a specific bearer (signaling radio bearer, data radio bearer), such as signaling radio bearer 0, signaling radio bearer 1, signaling radio bearer 2, etc. In another embodiment, the configuration information of the data mapping is used to transmit all bearers (such as all signaling radio bearers, or all data radio bearers, or all signaling radio bearers and data radio bearers).

[0244] - configuration information of a channel, which indicates the configuration of the channel used by the relay node to transmit data, and the information may include at least one of the following information: configuration information of the RLC entity, configuration information of the logical channel, etc. In one example, the channel is a PC5 RLC channel, and in another example, the channel is an air interface RLC channel. In one embodiment, the configuration information of the channel is used to transmit one or more specific bearers (signaling radio bearer, data radio bearer), such as signaling radio bearer 0, signaling radio bearer 1, signaling radio bearer 2, etc. In another embodiment, the configuration information of the channel is used to transmit all bearers (such as all signaling radio bearers, or all data radio bearers, or all signaling radio bearers and data radio bearers).

[0245] In an example, if a relay node is in an idle or inactive state, when it receives a message transmitted by a child node through a specific channel (such as PC5 RLC channel), on the one hand, it will transmit the received message to the parent node based on the above configuration information, and on the other hand, it can also start the process of connection setup / reestablishment / resume. In this way, the connection setup / reestablishment / resume procedure of the node can be performed in parallel with the procedure of the relay node, which reduces the time delay of the child node accessing the network.

[0246] * condition indication information used to indicate a condition for the relay node to perform data transmission (and / or transmit the above-mentioned “first notification message”). In one example, if the condition indicated by the information is not met, the relay node stops data transmission, or the relay node starts the procedure of connection setup / resume. The information may indicate at least one of the following information:

[0247] - second time indication information, which indicates the time to perform data transmission (and / or transmit the above-mentioned “first notification message”). In one example, the relay node can perform data transmission within the time indicated by the information. In another example, the relay node needs to transmit the above-mentioned “first notification message” after the time indicated by the information. In one implementation, after receiving the above-mentioned "second configuration message", the relay node starts a timer, and the length of the timer is the time indicated by the indication information. When the timer expires, the relay node stops the data transmission, or transmit a "first notification message."

[0248] - second measurement result threshold indication information, which indicates the measurement result required for data transmission (and / or transmitting the above-mentioned “first notification message”) (such as Reference Signal Receiving Power (RSRP), Reference Signal Receiving Quality (RSRQ), etc.) The measurement result can be the measurement result of the air interface or the measurement result of the sidelink. Furthermore, the measurement result can be a measurement result on a link between the relay node and a node (parent node) in the uplink direction, or a measurement result on a link between the relay node and a node (child node) in the downlink direction. In one embodiment, when the measurement result is less than (or greater than) the threshold indicated by the information, the relay node stops the data transmission or the relay node transmits the above-mentioned "first notification message."

[0249] - second data amount indication information, which indicates a threshold of the data transmission amount for the relay node to perform data transmission (and / or transmit the above-mentioned “first notification message”), and the data transmission amount can be the transmitted data amount of all user equipment, or the transmitted data amount of the specific user (i.e., the indication information also includes the identification information of the specific user equipment), or the transmitted data amount of the specific bearer of the specific user (that is, the indication information also includes the identification information of the specific user equipment and the identification information of the bearer). In one implementation, when the data amount is greater than (or less than) the threshold indicated by the information, the relay node can perform data transmission (or serve multi-hop relay network) in a specific state (such as connected state, idle state or inactive state), otherwise, the relay node needs to enter the connected state.

[0250] - area indication information, which indicates the area where the relay node performs data transmission, and the information may include at least one of the following information:

[0251] -- identification information of a cell, which indicates that the relay node can transmit data only when it is in the cell indicated by the information;

[0252] -- identification information of a node, which can identify the base station, indicates that the relay node can transmit data only when it is in the node indicated by the information;

[0253] -- area identification information, which indicates that the relay node can transmit data only when it is in the area indicated by the information.

[0254] The above-mentioned first configuration message can be an RRC Reconfiguration message, a system message, an RRC Release message, or other messages.

[0255] When the relay node receives the first configuration message, it may include at least one of the following behaviors:

[0256] ■ If the first configuration message is used to release the relay node to an idle state or an inactive state, the relay node enters an idle state or an inactive state and saves the configuration information in the first configuration message. When the relay node needs to transmit data, it will transmit data according to the information in the first configuration message.

[0257] ■ Receive a message 1 transmitted by a child node of the relay node. In one example, the message 1 may include a connection establishment request message, a connection resume request message or a connection reestablishment request message of the child node, and in another example, the message 1 includes a connection establishment request message, a connection resume request message or a connection reestablishment request message of the other node.

[0258] ■ Assign an identification information to the child node. In one example, the identification information is assigned based on the "second identification information of user equipment" contained in the "data transmission configuration information" in the above step 1-0, such as selecting one identification information from the "second identification information of user equipment". Further, the relay node needs to meet at least one of the following conditions when allocating the identification information or adding the allocated identification information in the header of the data packet containing the message 1 (in one example, if at least one of the conditions is not met, the relay node starts the connection establishment or connection resume process):

[0259] * The relay node is in a non-connected state (such as an idle state and an inactive state).

[0260] * The relay node is in a connected state.

[0261] * The relay node obtains the “second identification information of user equipment” from the “data transmission configuration information” in step 1-0, and the “second identification information of user equipment” also includes the identification information that has not been allocated.

[0262] * The relay node receives the data packet containing the message 1 through a specific channel (such as RLC channel of PC5, sidelink RLC channel, sidelink RLC channel 0, etc.).

[0263] ■ Forward the message 1.

[0264] * If the header of the received data packet containing the message 1 contains at least one of the identification information of the user and the bearer information, the data packet containing the message 1 also contains at least one of the identification information of the user and the bearer information when it is transmitted.

[0265] * If the header of the received data packet containing the message 1 does not contain identification information of the user and bearer information, at least one of the following information is added to the header of the data packet containing the message 1:

[0266] - Identification information of first user equipment, in one example, the identification information of the first user equipment is allocated by the relay node, and further, the allocated identification information is allocated based on the “second identification information of user equipment” included in the "data transmission configuration information" in the above step 1-0, such as selecting one identification information from the “second identification information of user equipment”;

[0267] - Identification information of a bearer of the first user equipment, which identifies the radio bearer (such as SRB0, SRB1, SRB2, etc.) that carries the message a;

[0268] ■ If the header of the received data packet containing the message 1 contains identification information of the user, the information in the header of the data packet containing the message 1 is recorded, such as the identification information of the user, which can help the relay node to know that if the relay node receives the data packet transmitted to the node identified by the "identification information of the user ", the relay node can forward it to the child node of the relay node.

[0269] ■ The configuration used when forwarding the received data packet containing the message 1 can be given by the "data transmission configuration information" in the above step 1-0 (such as the configuration information of data mapping, the configuration information of the channel, such as the configuration information of data mapping required for transmitting the message carried by SRB0 / 1, and the configuration information of the channel required for transmitting the message carried by SRB0 / 1). In another example, the configuration used when forwarding the data packet containing the message 1 may be pre-configured, such as the configuration of RLC channel of PC5, the configuration of the sidelink RLC channel, and the configuration of the sidelink RLC channel 0 / 1.

[0270] ■ Transmit a fifth notification message to the first network node (such as transmitting the fifth notification message through the network connected to the parent node (at the next higher level) or directly transmitting to the first network node, and an example of this message is SidelinkUEInformation message). The notification message includes information of the node directly or indirectly connected to the relay node (such as the first user equipment, the other node connected to the first relay node, the other node connected to the second relay node, the other node connected to the third relay node), such as identification information (such as local ID) of the node, and after receiving this message, the first network node will transmit, to the relay node, all data packets transmitted to the node indicated by the identification information contained in the fifth notification message.

[0271] Further, the condition that triggers the first node to transmit the above-mentioned first notification message may be at least one of the following conditions:

[0272] ■ The first node is at least one of:

[0273] * a relay node in the multi-hop relay network

[0274] * a third relay node, that is, a node that provides the function of connecting the first user equipment to the network

[0275] * a second relay node, that is. a node that provides a function of connecting the first user equipment to a third relay node

[0276] * first relay node, e.g. connected via sidelink or PC5 link

[0277] ■ There are one or more relay nodes between the first node and the first user equipment.

[0278] ■ The number of relay nodes between the first node and the first user equipment is less than a certain threshold (the threshold can be network configured, or predefined), or greater than a certain threshold (the threshold can be network configured, or predefined).

[0279] ■ The number of relay nodes between the first node and the third relay node is less than a certain threshold (the threshold can be network configured, or predefined), or greater than a certain threshold (the threshold can be network configured, or predefined).

[0280] ■ The number of relay nodes between the first node and the first relay node is less than a certain threshold (the threshold can be network configured or predefined), or greater than a certain threshold (the threshold can be network configured or predefined).

[0281] ■ The first node receives a notification message transmitted by another node, and the content of the notification message can refer to the above-mentioned “first notification message”, or the notification message contains at least one of information in the above-mentioned "first notification message."

[0282] ■ The first node is in a connected state (such as an RRC connected state).

[0283] ■ The first node is in an idle state (e.g., RRC idle state) or inactive state (e.g., RRC inactive state).

[0284] ■ The first node does not complete at least one of the following behaviors within a specified time (in one example, the specified time can be configured by the base station or predefined) or before a timer (in one example, the value of the timer is configured by the base station, or predefined) expires:

[0285] * relay node selection or reselection, i.e. selection or reselection to a relay node, or the serving cell of the relay node of the selection or reselection is the same as the serving cell of the first node (or the serving cell of the first user equipment). In other words, if the serving cell of the relay node selected or reselected by the first node within a specified time or before the timer expires is different from the serving cell of the first node (or the serving cell of the first user equipment), the first node transmits a “first notification message”, and vice versa, the first node may transmit the following “first assistant message” to the base station or first user equipment.

[0286] * reestablishment, or the cell of the reestablishment is the same as the serving cell of the first node (or the serving cell of the first user equipment). In other words, if the cell re-established by the first node within a specified time or before the timer expires is different from the serving cell of the first node (or the serving cell of the first user equipment), then the first node transmits a "first notification message".

[0287] * cell selection or reselection, i.e. selection or reselection to a cell, or the cell of the selection or reselection is the same as the serving cell of the first node (or the serving cell of the first user equipment). In other words, If the cell selected or reselected by the first node within a specified time or before the timer expires is different from the serving cell of the first node (or the serving cell of the first user equipment), the first node transmits a "first notification message".

[0288] * handover

[0289] * connection setup

[0290] * connection resume

[0291] ■ The first node occurs at least one of the following behaviors:

[0292] * relay node reselection or selection. In one example, this behavior is performed by the first node based on the configuration of the base station, such as determining whether to perform this behavior according to the above "relay node behavior indication information" in the "first configuration message". Further, the serving cell of the reselected or selected relay node (or the cell indicated by the reselected or selected relay node to the first node) is different from the cell serving the first node (or the cell serving the first user equipment).

[0293] * Reestablishment. In one example, the behavior is performed by the first node based on the configuration of the base station, such as determining whether to perform the behavior according to the above "relay node behavior indication information" in the "first configuration message". The behavior includes at least one of the following behaviors: starting a reestablishment procedure; a reestablishment failure; a reestablishment success; a reestablishment success and the cell accessed after reestablishment is different from the cell connected to the first node before reestablishment.

[0294] * a link failure. The behavior includes at least one of the following behaviors: an air interface radio link failure (such as when the first node is the above-mentioned third relay node), a connection failure or RRC failure, a sidelink failure.

[0295] * handover, or the target cell of the handover is different from the serving cell of the first node or the first user equipment.

[0296] * cell reselection or selection. In one example, this behavior is performed by the first node based on the configuration of the base station, such as determining whether to perform this behavior based on the above "relay node behavior indication information" in the "first configuration message". Further, the reselected or selected cell is different from the serving cell of the first node or the first user equipment. In one embodiment, if the first node is in the idle state or inactive state, when the first node performs cell reselection or cell selection, it does not need to transmit the above-mentioned “first notification message”. In other words, if the first node is in the connected state, when the first node performs cell reselection or cell selection, the above “first notification message” needs to be transmitted.

[0297] * a sidelink release

[0298] As shown in Figure 3, the above conditions can also be applied to trigger the second node to transmit a notification message (such as a second notification message, for the information contained in this message, please refer to the description in the above-mentioned “first notification message”) to the third node (other nodes different from the above-mentioned first node and second node, which can be any one of the first / second / third / fourth relay nodes, or can also be the first user equipment), just replace the "first node" in the above condition with the "second node".

[0299] Further, the behavior of the second node after receiving the above-mentioned first notification message will include at least one of the following behaviors (further, when performing at least one of the following behaviors, the second node needs to be at least one of the following nodes: a relay node in a multi-hop relay network, a third relay node, a second relay node, the first relay node, there are one or more relay nodes between the second node and the first user equipment, and the number of relay nodes between the second node and the first user equipment is less than a certain threshold (the threshold can be configured by the network or predefined), or greater than a certain threshold (the threshold can be configured by the network or predefined), the number of relay nodes between the second node and the third relay node is less than a certain threshold (the threshold can be configured by the network or predefined), or greater than a certain threshold (the threshold can be configured by the network or predefined), the number of relay nodes between the second node and the first relay node is less than a certain threshold (the threshold can be configured by the network or predefined), or greater than a certain threshold (the threshold can be configured by the network or predefined)):

[0300] ■ Start a timer. In one example, the timer is used to determine the time it takes for the second node to perform at least one of the following behaviors: selection or reselection of a relay node, reestablishment, cell selection or reselection, handover, connection setup, connection resume, waiting for a request of the first user equipment (such as a reestablishment request, a connection establishment request, or a data packet from a special channel (e.g. Radio link control channel). Further, if the first node does not complete at least one of the following behaviors within a specified time (in one example, the specified time can be configured by the base station or predefined) or before the timer expires, the second node transmits the above-mentioned "second notification message":

[0301] * selection or reselection to a relay node, or the serving cell of the relay node of the selection or reselection is the same as the serving cell of the second node (or the serving cell of the first user equipment). In other words, if the serving cell of the relay node selected or reselected by the second node within a specified time or before the timer expires is different from the serving cell of the second node (or the serving cell of the first user equipment), the second node transmits a “second notification message”, and vice versa, the second node may transmit the following “first assistant message” to the base station or first user equipment.

[0302] * a reestablishment success, or the cell of the reestablishment is the same as the serving cell of the second node (or the serving cell of the first user equipment). In other words, if the cell re-established by the second node within a specified time or before the timer expires is different from the serving cell of the second node (or the serving cell of the first user equipment), then the second node transmits a "second notification message".

[0303] * selection or reselection to a cell, or the cell of the selection or reselection is the same as the serving cell of the second node (or the serving cell of the first user equipment). In other words, If the cell selected or reselected by the second node within a specified time or before the timer expires is different from the serving cell of the second node (or the serving cell of the first user equipment), the second node transmits a "second notification message".

[0304] * handover complete.

[0305] * a connection establishment complete, or a connection resume complete.

[0306] ■ Transmit a notification message to other nodes. The other nodes are nodes that establish a link (such as a sidelink or a PC5 link) with the second node. For example, transmit the above-mentioned "second notification message" to a third node (other nodes different from the above-mentioned first node and second node, which can be any one of the first / second / third / fourth relay nodes, or can also be first user equipment). The content contained in the notification message can refer to the above-mentioned “first notification message”. In one example, the content in the notification message is determined based on the “first notification message” transmitted by the first node to the second node (e.g., copying the information in the “first notification message” transmitted by the first node into the notification message). In another example, the content in the notification message is generated by the second node itself (e.g., the notification message includes information relating to the second node, such as the above-mentioned first indication information). In another example, the notification message is the “first notification message” transmitted by the first node.

[0307] ■ Recover the link. The behavior includes at least one of the following behaviors (further, the above behavior may be determining whether to perform this behavior based on the above "relay node behavior indication information" in the "first configuration message"):

[0308] * reestablishment. In one embodiment, the reestablishment is performed by the first node. In one example, if the cell information contained in the “first notification message” received by the second node (such as the above-mentioned "cell identification information" in the "first assistant information") is different from the serving cell of the second node (or the first serving cell of the user equipment), the second node can directly start the reestablishment process on the cell (without performing cell selection or reselection, and directly transmitting a reestablishment connection request message). In another example, if the cell information contained in the “first notification message” received by the second node (such as the above-mentioned "cell identification information" in the "first assistant information") is the same as the serving cell of the second node (or the serving cell of the first user equipment), the second node can directly start the reestablishment process on the cell (without performing cell selection or reselection, and directly transmitting a reestablishment connection request message).

[0309] * establishment of the link again, which may be done by at least one of: relay node selection or reselection, reestablishment, cell reselection or selection. When the link connection is successfully established (such as a suitable relay node is selected for connection, the reestablishment is successful, or a suitable cell is selected), the second node can determine at least one of the subsequent behaviors according to the cell where the connection is established (such as the serving cell of the selected relay node, the cell where the reestablishment is located, and the cell selected by cell reselection or selection):

[0310] - If the cell (the cell in which the connection is established) is different from the serving cell of the second node (or the serving cell of the first user equipment), the second node transmits a "second notification message".

[0311] - If the cell (the cell in which the connection is established) is the same as the serving cell of the second node (or the serving cell of the first user equipment), the second node transmits a "second notification message".

[0312] - If the cell (the cell in which the connection is established) is the same as the serving cell of the second node (or the serving cell of the first user equipment), the second node can transmit the following “first assistant message” to the base station or the first user equipment, thereby updating the path serving the first user equipment.

[0313] - If the cell (the cell in which the connection is established) is different from the serving cell of the second node (or the serving cell of the first user equipment), the second node transmits a "second notification message", and the second node can directly start the reestablishment process on the cell (without performing the cell selection or reselection, directly transmitting a connection reestablishment request message).

[0314] ■ enter the idle state. Further, in one example, when the second node has no data transmission, such as when data radio bearer is not configured, the second node can enter the idle state. In another example, when the second node does not receive a request (such as a reestablishment request, a connection setup request, or a data packet from a special channel (such as a Radio link control channel)) from the first user equipment within a specified time or before a specified timer expires (the specified time, or the time of the timer is pre-configured by the base station), it can enter the idle state

[0315] ■ The behavior of entering an inactive state. Further, in one example, the second node can enter the inactive state when the second node has no data transmission, such as when data radio bearer is not configured. In another example, when the second node does not receive a request (such as a reestablishment request, a connection setup request, or a data packet from a special channel (such as a Radio link control channel)) from the first user equipment within a specified time or before a specified timer expires (the specified time, or the time of the timer is pre-configured by the base station), it can enter the inactive state.

[0316] Figure 4 is a second flow chart according to the present disclosure.

[0317] Figure 5 is a third flow chart according to the present disclosure.

[0318] In order to help the first network node configure the multi-hop relay network, the relay node (such as the first / second / third relay node, the above-mentioned first node, the above-mentioned second node) can also transmit a first assistant message to the first network node (as shown in Figure 4), or the relay node transmits a first assistant message to the first user equipment. Then, the first user equipment transmits a second assistant message to the base station (as shown in Figure 5), or the first user equipment transmits a first assistant message to the relay node, and then the relay node transmits a second assistant message to the first network node or other relay nodes. The effect of the first assistant message or the second assistant message is to provide assistant information, which can help the base station reconfigure the transmission path serving the first user equipment or release the configuration information for serving the first user equipment on the transmission path. In one example, if a second relay node connects to a new node (such as a connected node by relay node reselection, such as an intermediate relay node, a last relay node, or a connected base station by cell selection or reselection), while the cell serving the new node is the same as the cell serving the first user equipment (or the cell serving the intermediate relay node), or the cell selected by cell selection or reselection is the same as the cell serving the first user equipment (or the cell serving the intermediate relay node), the relay node may transmit a first assistant message to the base station. In another example, the relay node serves the first user equipment in an idle state or inactive state. If the relay node needs to perform a connection setup or connection resume procedure, after the procedure is successful, the relay node can transmit the first assistant message to the first network node, which can help the first network node obtain information on the first user equipment served by the relay node, and then continue to configure it to serve the first user equipment (in this example, the first assistant message may be an RRC establishment complete message or an RRC resume complete message). In another example, when the first user equipment changes the transmission path, or the first user equipment has no data to transmit, the first user equipment can inform the first network node or relay node through the assistant message, and then the first network node or relay node can release the configuration serving the first user equipment, or start the procedure of releasing the service for the first user equipment. The beneficial effect of this message is to provide assistant information to the first network node, thereby quickly configuring the multi-hop network serving the user equipment and reducing the interruption in data transmission. In one example, this step may occur after step 1-1 above. The first assistant message or the second assistant message may be at least one of the following information:

[0319] ■ identification information of a node, such as local ID. The node is the node to which the relay node is newly connected, such as the second relay node, the third relay node, the first relay node, etc. In one example, the node may be selected through a relay node reselection process or selection process.

[0320] ■ cell identification information, which indicates the serving cell where the new node connected to the relay node is located.

[0321] ■ path identification information, which indicates a transmission path where a new node connected to the relay node is located, or a path with the new node as a destination node.

[0322] ■ identification information of user equipment, which indicates an identification of a user equipment served by the relay node.

[0323] ■ indication information of data termination, which is used to indicate that the data transmission of the user equipment has been ended, or to indicate that the first assistant message or the second assistant message is the last data packet transmitted by the first user equipment to the first network node. When the first network node receives this information, it can start to release the configuration information serving user equipment on the transmission path. In one example, when the first user equipment wants to change the transmission path (e.g., when receiving a configuration message of transmission path change, such as RRC reconfiguration message), the indication information of data termination is transmitted.

[0324] The above-mentioned first / second assistant message can be a UE assistant information message, a connection setup complete message, a connection resume complete message, a connection reestablishment complete message, or other messages, or the first / second assistant message is transmitted through the information contained in the SRAP header.

[0325] Figure 6 is a fourth flow chart according to the present disclosure.

[0326] When the first user equipment accesses the first network node through the multi-hop relay network, its access delay will increase according to the hop count of the network. In order to avoid the connection failure, the first network node can configure different access time for the first user equipment. Specifically, the first network node may transmit a second configuration message to the first user equipment (as shown in Figure 6), and the function of this message is to configure the first user equipment to establish a network connection. The beneficial effect of this message is to configure reasonable access time and reduce access failures of user equipment. The message includes at least one of the following information:

[0327] ■ first hop count information, which indicates the hop count related to the following "first time information" (so that the different time can be configured for different hop counts), such as the hop count of the multi-hop relay network serving the first user equipment, that is, the hop count from the first network node to the first user equipment (or from the third relay node to the first user equipment, or from the third relay node to the first relay node). The first user equipment may obtain hop count information from the first relay node to which it is connected.

[0328] ■ first time information, which is used to indicate the length of time. The time length indicates a length of time for the first user equipment to perform connection setup or connection resume or connection reestablishment (e.g., a length of time of timer T300, a length of time of timer T301, a length of time of timer T319, a length of time of timer T319a), i.e., the time within which the first user equipment needs to complete connection setup, connection resume, or connection reestablishment.

[0329] ■ reference time information, which is used to indicate a reference length of time for the first user equipment to perform connection setup or connection resume or connection reestablishment (such as a length of timer T300, a length of timer T301, a length of timer T319, a length of timer T319a).

[0330] ■ first time step information, which is used to indicate an increase step of the length of time. The time length indicates a length of time for the first user equipment to perform connection setup or connection resume or connection reestablishment (e.g., a length of time of timer T300, a length of time of timer T301, a length of time of timer T319, a length of time of timer T319a), i.e., the time within which the first user equipment needs to complete connection setup, connection resume, or connection reestablishment. In one example, the first user equipment will determine the length of time for connection setup or connection resume or connection reestablishment based on this information and the above-mentioned "first hop count information" and "reference time information" (for example, the length is equal to "reference time information" + "first hop count information"*"time step information")

[0331] ■ first time increment information, which is used to indicate information of an increase in a time length. The time length indicates a length of time for the first user equipment to perform connection setup or connection resume or connection reestablishment (e.g., a length of timer T300, a length of timer T301, a length of timer T319, a length of timer T319a). This information corresponds to the above-mentioned "first hop count information", and different "first hop count information" have different "first time increment information". In one example, the first user equipment will determine the length of time for connection setup or connection resume or connection reestablishment based on this information, the above-mentioned "reference time information", and the hop count (for example, the length is equal to the "reference time information" + "time step information" corresponding to the hop count of the first user equipment)

[0332] After receiving the above second configuration message, the first user equipment determines the time required to perform the procedure of accessing the first network device, and performs the procedure of accessing the first network device, such as connection setup, connection reestablishment, connection resume, etc. This process is performed through a multi-hop sidelink relay network, which includes one or more relay nodes.

[0333] When performing the procedure of accessing the first network device, the first user equipment will start a timer, and the length of the timer is determined based on the configuration information in the second configuration message. The method used includes at least one of:

[0334] ■ based on the first hop count information and the first time information. That is, the hop count of the access network of the first user equipment is determined, then the length of the timer is the first time information corresponding to the hop count.

[0335] ■ based on the first hop count information, the reference time information, and the first time step information. That is, the hop count of the access network of the first user equipment is determined, then the length of the timer is the reference time information + the hop count * first time step.

[0336] ■ based on the first hop count information, the reference time information, and the first time increment information. That is, the hop count of the access network of the first user equipment is determined, then the length of the timer is the reference time information + the first time increment information corresponding to the hop count.

[0337] The above-mentioned second configuration message can be an RRC Reconfiguration message, a system message, an RRC Release message, or other messages.

[0338] In combination with the above steps, the present invention includes the following possible implementations.

[0339] ■ Embodiment 1: After receiving the first notification message, the relay node directly enters the idle state or inactive state. For example, refer to the description in the above “the behavior of the second node after receiving the above-mentioned first notification message”.

[0340] ■ Embodiment 2: After receiving the first notification message, the relay node directly transmits a connection reestablishment request message without performing cell selection. For example, refer to the description in the above “the behavior of the second node after receiving the above-mentioned first notification message”.

[0341] ■ Embodiment 3: The relay node triggers the transmitting of the above-mentioned first notification message based on the reestablishment or receiving the notification message. For example, refer to the description in the above “the condition that triggers the first node to transmit the above-mentioned first notification message”.

[0342] ■ Embodiment 4: When the first network node can release the relay node in the multi-hop relay network to the idle state or inactive state, it configures the relay node to continue to perform the data transmission in the idle state or inactive state. For example, the relay node performs data transmission based on the information in the above "first configuration message";

[0343] ■ Embodiment 5: The relay node can determine whether data transmission can be performed in the idle state or inactive state based on the configuration of the network, for example, the relay node determines based on the information in the above "first configuration message".

[0344] ■ Embodiment 6: The relay node determines the behavior after receiving the above-mentioned “first notification message” based on the configuration of the network, for example, the relay node determines based on the information in the above-mentioned "first configuration message".

[0345] ■ Embodiment 7, the user equipment determines the length of the timer for accessing the network based on the configuration of the network, such as the length of the timer for connection setup or connection resume or connection reestablishment (such as the length of timer T300, the length of timer T301, the length of timer T319, the length of time of timer T319a). For example, the user equipment makes a determination based on the information in the above "second configuration message".

[0346] In a multi-hop relay network, if the first user equipment needs to establish a connection through the multi-hop relay network (such as connection establishment, connection resume, connection reestablishment, etc.), the multi-hop relay network needs to transmit the message related to the connection establishment of the first user equipment. However, the time required for this process will be longer than that required for connection establishment in a single-hop network. The present invention hopes to reduce the time for the first user equipment to establish a connection in a multi-hop relay network through at least one of the above processes. An embodiment in which the first user equipment establishes a connection through a multi-hop network is given below. In this embodiment, the first user equipment, the first / second / third relay nodes, and the first network node are included.

[0347] ■ Step 0: The first user equipment transmits a message a to the first relay node. The message a includes the first message used by the first user equipment to connect the node, such as a connection establishment request message, a connection resume request message and a connection reestablishment request message. Further, the message a is transmitted through a specific channel (such as an RLC channel of PC5, a sidelink RLC channel, sidelink RLC channel 0, etc.). The first relay node will have at least one of the following behaviors:

[0348] * Forward the received message a to the parent node of the first relay node (such as the second relay node), such as the second relay node or the third relay node. In one example, the configuration used by the first relay node when forwarding the message a can be given through the "data transmission configuration information" in the above step 1-0 (such as the configuration information of data mapping, the configuration information of the channel, such as the configuration information of data mapping required for transmitting the message carried by SRB0, and the configuration information of the channel required for transmitting the message carried by SRB0). In another example, the configuration used by the first relay node when forwarding the message a may be pre-configured, such as the configuration of RLC channel of PC5, the configuration of the sidelink RLC channel, and the configuration of the sidelink RLC channel 0.

[0349] * If the first relay node is in a non-connected state, it can start the connection establishment or connection resume process of the first relay node. In one example, if the first relay node is in a non-connected state (such as an idle state and an inactive state), the first relay node starts the process.

[0350] * When forwarding message a, at least one of the following information is added in the packet header (such as a SRAP packet header):

[0351] - Identification information offirst user equipment, in one example, the identification information of the first user equipment is allocated by the first relay node, and further, the identification information allocated by the first relay node is allocated based on the “second identification information of user equipment” included in the "data transmission configuration information" in the above step 1-0, such as selecting one identification information from the “second identification information of user equipment”;

[0352] - Identification information of a bearer of the first user equipment, which identifies the radio bearer (such as SRB0, SRB1, SRB2, etc.) that carries the message a;

[0353] Further, the first relay node needs to meet at least one of the following conditions when adding the above information in the header of the data packet (in one example, if at least one of the conditions is not met, the first relay node starts the connection establishment or connection resume process):

[0354] - The first relay node is in a non-connected state (such as an idle state and an inactive state).

[0355] - The first relay node is in a connected state.

[0356] - The first relay node obtains the “second identification information of user equipment” from the “data transmission configuration information” in step 1-0, and the “second identification information of user equipment” also includes the identification information that has not been allocated.

[0357] - The first relay node receives the message a through a specific channel (such as an RLC channel of PC5, a sidelink RLC channel, a sidelink RLC channel 0, etc.).

[0358] - The packet header (such as SRAP packet header) of the data packet containing the message a received by the first relay node does not contain at least one of the identification information of the first user equipment and the identification information of the bearer of the first user equipment.

[0359] * When the first relay node enters the connected state, it transmits a second notification message to the first network node (such as transmitting the second notification message through the network connected to the parent node (at the next higher level), an example of which is SidelinkUEInformation message).The message includes information of the node directly or indirectly connected to the first relay node (such as the first user equipment, the other node connected to the first relay node), such as identification information (such as local ID) of the node, and after receiving this message, the first network node will transmit, to the first relay node, data packets transmitted to the node indicated by the identification information contained in the second notification message.

[0360] ■ Step 1: The second relay node receives the data packet containing the message a from the first relay node and includes at least one of the following behaviors:

[0361] * Forwarding the received data packet containing the message a to the parent node (at the next higher level) of the second relay node (such as the third relay node). In one example, the configuration used by the second relay node when forwarding the data packet containing the message a can be given through the "data transmission configuration information" in the above step 1-0 (such as the configuration information of data mapping, the configuration information of the channel, such as the configuration information of data mapping required for transmitting the message carried by SRB0, and the configuration information of the channel required for transmitting the message carried by SRB0). In another example, the configuration used by the first relay node when forwarding the data packet containing the message a may be pre-configured, such as the configuration of RLC channel of PC5, the configuration of the sidelink RLC channel, and the configuration of the sidelink RLC channel 0.

[0362] * Record the information in the header of the data packet containing the message a, such as "identification information of first user equipment", which can help the second relay node to know that if the second relay node receives the data packet transmitted to the node identified by the "identification information offirst user equipment", the second relay node can forward it to the first relay node.

[0363] * If the second relay node is in a non-connected state, it can start the connection establishment or connection resume process of the second relay node. In one example, if the second relay node is in a non-connected state (such as an idle state and an inactive state), the second relay node can start the process.

[0364] * When the second relay node enters the connected state, it transmits a third notification message to the first network node (such as transmitting the third notification message through the network connected to the parent node (at the next higher level), and an example of this message is SidelinkUEInformation).The message includes information of the node directly or indirectly connected to the second relay node (such as the first user equipment, the other node connected to the second relay node), such as identification information (such as local ID) of the node, and after receiving this message, the first network node will transmit, to the second relay node, data packets transmitted to the node indicated by the identification information contained in the third notification message.

[0365] ■ Step 2: The third relay node receives the data packet containing the message a from the second relay node and includes at least one of the following behaviors:

[0366] * If the third relay node is in a non-connected state, it can start the connection establishment or connection resume process of the third relay node. In one example, if the third relay node is in a non-connected state (such as an idle state and an inactive state), the third relay node starts the process.

[0367] *

[0368] Transmit a fourth notification message to the first network node, one example of which is a sidelink user information message (SidelinkUEInformation) .The message includes information of the node directly or indirectly connected to the third relay node (such as the first user equipment, the other node connected to the first relay node, the other node connected to the second relay node, the other node connected to the third relay node), such as identification information (such as local ID) of the node, and after receiving this message, the first network node will transmit, to the third relay node, data packets transmitted to the node indicated by the identification information contained in the fourth notification message.

[0369] ■ Step 3: The first network node transmits a response message (such as a connection establishment message, a connection resume message and a connection reestablishment message) of the message a to the first user equipment. The response message is transmitted through the third relay node, the second relay node and the first relay node, and the configuration used to transmit the response message between the two relay nodes can be given in the "data transmission configuration information" in the above step 1-0 (such as the configuration information of data mapping, the configuration information of the channel, such as the configuration information of data mapping required for transmitting the message carried by SRB0 / 1, and the configuration information of the channel required for transmitting the message carried by SRB0 / 1). In another example, the configuration used by the first relay node when forwarding the data packet containing the message a may be pre-configured, such as the configuration of RLC channel of PC5, the configuration of the sidelink RLC channel, and the configuration of the sidelink RLC channel 0 / 1.

[0370] Through the above steps, if the first relay node or the second relay node is in a non-connected state, the first relay node or the second relay node can carry out its own connection establishment or connection resume process when forwarding the message a from the first user equipment, so that the process of connection establishment or resume of the first user equipment can be accelerated.

[0371] FIG. 7 is a block diagram of a terminal or user equipment (UE) 700 according to an embodiment of the disclosure.

[0372] The terminal is an electronic device capable of wireless communication, may include a User Equipment (UE), a portable phone, a smartphone, a tablet, an Internet of things (IoT) device, etc., having various form factors, and may perform wireless communication with a base station (BS) through a wireless channel.

[0373] Referring to FIG. 7, the UE 700 may include at least one transceiver (hereinafter, referred to as simply “transceiver”) 701, at least one processor (hereinafter, referred to as simply “processor”) 702, and at least one memory (hereinafter, referred to as simply “memory”) 703. According to at least one or a combination of methods corresponding to the embodiments described in the present disclosure, the transceiver 701, the processor 702, and the memory 703 of the UE 700 may operate. However, components of the UE 700 are not limited to the exemplary components illustrated in FIG. 7. In another embodiment, the UE 700 may further include additional components in addition to the above-mentioned components, or some components may be omitted. Further, in some embodiments, any combination of the transceiver 701, the processor 702, or the memory 703 may be integrated in the form of one component.

[0374] The transceiver 701 may be a communication circuit or communication circuitry that enables the UE 700 to perform wireless communication with a node or an entity of a network. For example, the transceiver 701 may enable the UE 700 to transmit or receive a signal to or from a BS through cellular communication, or to transmit or receive a signal to or from another UE through cellular communication. For example, the transceiver 701 may support at least one of various cellular communication technologies including 3rd generation (3G), 4th generation (4G), long term evolution (LTE), 5th generation (5G) NR, 6th generation (6G), and various cellular wireless communication technologies supported by the transceiver (701) may include all subsequent generations of evolved wireless communications.

[0375] According to an embodiment, the UE 700 may include a plurality of transceivers. For example, in the case of supporting evolved-universal terrestrial radio access-new radio (E-UTRA-NR) sual connectivity (EN-DC), the UE 700 may include a first transceiver supporting the 4G LTE wireless communication and a second transceiver supporting the 5G NR wireless communication. According to another embodiment, in the case of supporting NR-dual connectivity (NR-DC), the UE 700 may include a plurality of transceivers supporting the 5G NR wireless communication. According to still another embodiment, in the case of supporting near field wireless communication, the UE 700 may separately include a transceiver supporting at least one standard in the group of wireless communication protocol standards as defined in the protocol standards for Bluetooth®, wireless local area network (WLAN) network (including institute of electrical and electronics engineers (IEEE) 802.11-2016 standard or its amendments, e.g., 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be, without being limited thereto).

[0376] According to an embodiment, the transceiver 701 may include various circuit structures used to transmit or receive signals to or from a BS through a wireless channel. The signals may include control information and data. For example, the transceiver 701 may include a radio frequency (RF) transmitter for up-converting and amplifying the frequency of a transmitted signal and an RF receiver for low-noise-amplifying a received signal and down-converting the frequency thereof. The transceiver 701 may output a signal received through a wireless channel to the processor 702 and may transmit, through a wireless channel, a signal output from the processor 702.

[0377] The processor 702 may control general operations of the UE 700 according to embodiments of the disclosure. The processor 702 may be implemented by one or more integrated circuit (or circuitry) (IC) chips and may execute various data processings. The processor 702 may include at least one electric circuit, and may execute instructions (or a program, codes, data, etc.) stored in the memory 703, individually, collectively or in any combination thereof. Further, the processor 702 may include a single-core processor or multi-core processor, and may include a processor assembly including a plurality of processing circuits (circuitry) according to a specific implementation scheme.

[0378] The processor 702 may be electrically, operatively, or communicatively coupled to the transceiver 701 to control the transceiver 701.

[0379] The processor 702 may include at least one processor (or processing circuitry), and the at least one processor may perform the following operations individually, collectively or in any combination thereof. For example, the processor 702 may include a communication processor (CP) configured to control communication operations and an application processor (AP) configured to control execution of an upper layer (for example, an application layer) . In a specific embodiment, at least a part of the processor 702 may be included in one chip and the other part of the processor 702 may be included in another chip. Otherwise, at least one processor may be included in another component, for example, the transceiver 701 or the memory 703.

[0380] The processor 702 may perform or control or cause an operation of the UE 700 for executing at least one or a combination of methods according to embodiments of the disclosure. For example, the processor 702 may control operations of the UE 700 for processing a downlink signal received from a BS or generating and transmitting an uplink signal to a BS. To this end, the processor 702 may execute a computer program, codes, or instructions stored in the memory 703, so as to control other components of the UE 700 to enable execution of various operations.

[0381] The memory 703 corresponds to a hardware storage device capable of temporarily or permanently storing information and may include one or more storage media. For example, the memory 703 may include a memory assembly including one or more storage media. For example, the one or more storage media may include permanent memory, such as a hard drive, flash memory, or read-only memory (ROM), semipermanent memory, such as random access memory (RAM), cache memory, or a combination thereof.

[0382] The memory 703 may be electrically, operatively, or communicatively coupled to the processor 702 and may be accessed by the processor 702.

[0383] The memory 703 may store a computer program, codes, or instructions executable by the processor 702. According to an embodiment, a computer program, codes, or instructions executable by the processor 702 may be either stored in a single memory device or separated and distributedly stored in two or more memory devices. By executing the instructions stored in the memory 703, the processor 702 may perform various functions according to an embodiment of the disclosure.

[0384] According to an embodiment of the disclosure, operations of the UE 700 may be caused to be performed based on execution of instructions (or a computer program or codes) stored in the memory 703 by at least one processor (or processing circuitry) configured to execute the same individually, collectively, or in any combination thereof, based on processing circuitry that is not configured to execute instructions, and / or based on components of processing circuitry that is not configured to execute instructions.

[0385] FIG. 8 is a block diagram of a base station (BS) 800 according to an embodiment of the disclosure.

[0386] The BS 800 may perform wireless communication with at least one user equipment (UE) located within the area of the BS 800 through a wireless channel.

[0387] Referring to FIG. 8, the BS 800 may include at least one transceiver (hereinafter, referred to as simply “transceiver”) 801, at least one processor (hereinafter, referred to as simply “processor”) 802, and at least one memory (hereinafter, referred to as simply “memory”) 803. According to at least one or a combination of methods corresponding to the embodiments described in the present disclosure, the transceiver 801, the processor 802, and the memory 803 of the BS 800 may operate. However, components of the BS 800 are not limited to the exemplary components illustrated in FIG. 8. In another embodiment, the BS 800 may further include additional components in addition to the above-mentioned components, or some components may be omitted. Further, in some embodiments, any combination of the transceiver 801, the processor 802, or the memory 803 may be integrated in the form of one component.

[0388] The transceiver 801 may be a communication circuit or communication circuitry that enables the BS 800 to perform wireless communication with a node or an entity of a network. For example, the transceiver 801 may enable the BS 800 to transmit or receive a signal to or from the UE X00 through cellular communication, or to transmit or receive a signal to or from another network entity through wireless communication. For example, the transceiver 801 may support various cellular communication technologies including 3rd generation (3G), 4th generation (4G), long term evolution (LTE), 5th generation (5G) NR, 6th generation (6G), and various cellular wireless communication technologies supported by the transceiver (801) may include all subsequent generations of evolved wireless communications.. According to an embodiment, the transceiver 801 may include various circuit structures used to transmit or receive signals to or from a UE through a wireless channel. The signals may include control information and data. For example, the transceiver 801 may include a radio frequency (RF) transmitter for up-converting and amplifying the frequency of a transmitted signal and an RF receiver for low-noise-amplifying a received signal and down-converting the frequency thereof. The transceiver 801 may output a signal received through a wireless channel to the processor 802 and may transmit, through a wireless channel, a signal output from the processor 802.

[0389] Meanwhile, according to an embodiment of the present disclosure, the BS 800 may perform communication with a node or an entity of a network through wired or wireless communication. For example, the BS 800 may perform wired or wireless communication with an adjacent BS, or a node or an entity of a core network through a backhaul network. Although not illustrated in FIG. 8, when the BS 800 performs wired communication, the BS 800 may further include a separate network interface for wired communication in addition to the transceiver 801. The network interface may be referred to as network interface circuitry or communication interface circuitry.

[0390] The processor 802 may control general operations of the BS 800 according to embodiments of the disclosure. The processor 802 may be implemented by one or more integrated circuit (or circuitry) (IC) chips and may execute various data processings. The processor 802 may include at least one electric circuit, and may execute instructions (or a program, codes, data, etc.) stored in the memory 803, individually, collectively or in any combination thereof. Further, the processor 802 may include a single-core processor or multi-core processor, and may include a processor assembly including a plurality of processing circuits (circuitry) according to a specific implementation scheme.

[0391] The processor 802 may be electrically, operatively, or communicatively coupled to the transceiver 801 to control the transceiver 801.

[0392] The processor 802 may include at least one processor (or processing circuitry), and the at least one processor may perform the following operations individually, collectively or in any combination thereof. In a specific embodiment, at least a part of the processor 802 may be included in one chip and the other part of the processor 802 may be included in another chip. Otherwise, at least one processor may be included in another component, for example, the transceiver 801 or the memory 803.

[0393] The processor 802 may perform or control or cause an operation of the BS 800 for executing at least one or a combination of methods according to embodiments of the disclosure. For example, the processor 802 may control operations of the BS 800 for generating and transmitting a downlink signal to a UE or processing an uplink signal received from a UE. Otherwise, the BS 800 may transmit or receive a signal to or from a neighboring BS, transfer a signal received from a UE to an upper node of the network, or transmit a signal transferred from an upper node of the network to a UE. To this end, the processor 802 may execute a computer program, codes, or instructions stored in the memory 803, so as to control other components of the BS 800 to enable execution of various operations.

[0394] The memory 803 corresponds to a hardware storage device capable of temporarily or permanently storing information and may include one or more storage media. For example, the memory 803 may include a memory assembly including one or more storage media. For example, the one or more storage media may include permanent memory, such as a hard drive, flash memory, or read-only memory (ROM), semipermanent memory, such as random access memory (RAM), cache memory, or a combination thereof.

[0395] The memory 803 may be electrically, operatively, or communicatively coupled to the processor 802 and may be accessed by the processor 802.

[0396] The memory 803 may store a computer program, codes, or instructions executable by the processor 802. According to an embodiment, a computer program, codes, or instructions executable by the processor 802 may be either stored in a single memory device or separated and distributedly stored in two or more memory devices. By executing the instructions stored in the memory 803, the processor 802 may perform various functions according to an embodiment of the disclosure.

[0397] According to an embodiment of the disclosure, operations of the BS 800 may be caused to be performed based on execution of instructions (or a computer program or codes) stored in the memory 803 by at least one processor (or processing circuitry) configured to execute the same individually, collectively, or in any combination thereof, based on processing circuitry that is not configured to execute instructions, and / or based on components of processing circuitry that is not configured to execute instructions.

[0398] The UE or the base station may perform various communication procedures related to the control plane or the user plane by cooperating with one or more network entities based on wireless communication. For example, the UE may communicate with network entity such as an Access and Mobility Management Function (AMF) or a Session Management Function (SMF) via the base station, or the base station may perform at least one communication procedure by directly transmitting and receiving signals to / from, or relaying signals between, the network entities.

[0399] The structure of the above-described network entity will be described in more detail with reference to the drawings.

[0400] FIG. 9 is a block diagram of a network entity 900 according to an embodiment of the disclosure.

[0401] The network entity 900 may include an entity (apparatus, device, or server, etc.) that performs one or more network functions (NFs) or a part of a network function constituting a core network (e.g., a 5th generation (5G) core (5GC)) in a communication system. In this case, multiple NFs may be implemented within a single network entity, or a single NF may be distributed and implemented across a plurality of network entities. In addition, when an NF is implemented within the network entity, the NF may be implemented in the form of software, and in such a case, a program for operating the NF may be stored in memory of the network entity 900.

[0402] A single NF may be implemented by one or more instances, which may be deployed on the same network entity or distributed across multiple network entities to operate. The instance may be a software unit that logically executes a specific network function, and may be implemented in a form that is decoupled from physical hardware resources. Further, one or more NFs may be implemented in the form of one network slice to operate to satisfy specifications required by a particular service.

[0403] The NF may include at least one of an access and mobility management function (AMF), a session management function (SMF), a local session management function (L-SMF), a user plane function (UPF), a local user plane function (L-UPF), a policy control function (PCF), a unified data management (UDM), a unified data repository (UDR), a network exposure function (NEF), a network repository function (NRF), an application function (AF), a network slice selection function (NSSF), a network data analytics function (NWDAF), a network slice admission control function (NSACF), an authentication server function (AUSF), or a data network (DN).

[0404] Referring to FIG. 9, the network entity 900 may include at least one network interface 901, at least one processor 902 (hereinafter, “processor”), and at least one memory 903 (hereinafter, “memory”). As described above, a NF may be implemented in the form of a physical device such as the network entity 900, or may be virtualized and executed in the form of an instance. When implemented as an instance, the NF need not necessarily include physical components as illustrated in FIG. 9. In such a case, the instance may be logically represented as comprising one or more logical functional elements.

[0405] According to at least one or a combination of methods corresponding to the embodiments described in the present disclosure, the network interface 901, the processor 902, and the memory 903 of the network entity 900 may operate. However, components of the network entity 900 are not limited to the exemplary components illustrated in FIG. 9. In another embodiment, the network entity 900 may further include additional components in addition to the above-mentioned components, or some components may be omitted. Further, in an embodiment, the network interface 901, the processor 902, or the memory 903 may be integrated in the form of one component.

[0406] The network interface 901 is a collective term for a transmitter part of the network entity 900 and a receiver part of the network entity 900, and may be a communication circuit for transmitting or receiving a signal to or from a user equipment (UE), a base station (BS), or another network entity. Here, the communication circuit may include both a communication circuit for wireless communication and a communication circuit for a wired communication. For example, the network interface 901 may include a circuit, logic, hardware, etc., configured to exchange a control plane message or a user plane message with a UE, a BS, or other core network entities through wireless communication or wired communication. The network interface 901 may operate using various protocols (e.g., non-access stratum (NAS) protocol). The network interface 901 may also be referred to, for convenience of description or depending on implementation, as communication circuitry, network interface circuitry, or a communication interface circuitry.

[0407] The processor 902 may control general operations of the network entity 900 according to embodiments of the disclosure. The processor 902 may be implemented by one or more integrated circuit (or circuitry) (IC) chips and may execute various data processings. The processor 902 may include at least one electric circuit, and may execute instructions (or a program, codes, data, etc.) stored in the memory 903, individually, collectively or in any combination thereof. Further, the processor 902 may include a single-core processor or multi-core processor, and may include a processor assembly including a plurality of processing circuits (circuitry) according to a specific implementation scheme. Further, it should be noted that, according to another embodiment, in a case where NF is implemented in the form of an instance, the network function may be not necessarily configured by physical hardware.

[0408] According to an embodiment, the processor 902 may be electrically, operatively, or communicatively coupled to the network interface 901 to control the network interface 901.

[0409] The processor 902 may include at least one processor (or processing circuitry), and the at least one processor may perform the following operations individually, collectively or in any combination thereof. In a specific embodiment, at least a part of the processor 902 may be included in one chip and the other part of the processor 902 may be included in another chip. Otherwise, at least one processor may be included in another component, for example, the network interface 901 or the memory 903.

[0410] The processor 902 may perform or control or cause an operation of the network entity 900 for executing at least one or a combination of methods according to embodiments of the disclosure. For example, the processor 902 may control operations of the network entity 900 for exchanging a control plane message or a user plane message with a UE, a BS, or other core network entities through wireless or wired communication, using various protocols (e.g., NAS protocol). To this end, the processor 902 may execute a computer program, codes, or instructions stored in the memory 903, so as to control other components of the network entity 900 to enable execution of various operations.

[0411] The memory 903 corresponds to a hardware storage device capable of temporarily or permanently storing information and may include one or more storage media. For example, the memory 903 may include a memory assembly including one or more storage media. For example, the one or more storage media may include permanent memory, such as a hard drive, flash memory, or read-only memory (ROM), semipermanent memory, such as random access memory (RAM), cache memory, or a combination thereof.

[0412] The memory 903 may be electrically, operatively, or communicatively coupled to the processor 902 and may be accessed by the processor 902.

[0413] The memory 903 may store a computer program, codes, or instructions executable by the processor 902. According to an embodiment, a computer program, codes, or instructions executable by the processor 902 may be either stored in a single memory device or separated and distributedly stored in two or more memory devices. By executing the instructions stored in the memory 903, the processor 902 may perform various functions according to an embodiment of the disclosure.

[0414] According to an embodiment of the disclosure, operations of the network entity 900 may be caused to be performed based on execution of instructions (or a computer program or codes) stored in the memory 903 by at least one processor (or processing circuitry) configured to execute the same individually, collectively, or in any combination thereof, based on processing circuitry that is not configured to execute instructions, and / or based on components of processing circuitry that is not configured to execute instructions.

[0415] Meanwhile, although specific embodiments of the present disclosure have been described in detail, various modifications may be made without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be defined by the claims and equivalents thereof.

Claims

1.A method performed by a first relay user equipment (UE) in a wireless communication system, the method comprising:performing a relay reselection; andtransmitting, to the second relay UE, a notification message for a multi-hop sidelink based on the relay reselection, the notification message including a relay reselection indication,wherein the first relay UE relays communication between the second relay UE and another relay UE,wherein the second relay UE relays communication between the first relay UE and a remote UE,wherein the first relay UE is in a radio resource control (RRC) idle state or an RRC inactive state.2.The method of claim 1,wherein the notification message is transmitted to the second relay UE, if a first serving cell of the first relay UE is different from a second serving cell of the second relay UE.3.The method of claim 1,wherein a length of a timer associated with the multi-hop sidelink is identified based on a multi-hop count of the multi-hop sidelink and time information.4.A method performed by a second relay user equipment (UE) in a wireless communication system, the method comprising:receiving, from a first relay UE, a notification message for a multi-hop sidelink associated with a relay reselection, the notification message including a relay reselection indication,wherein the first relay UE relays communication between the second relay UE and another relay UE,wherein the second relay UE relays communication between the first relay UE and a remote UE,wherein the first relay UE is in a radio resource control (RRC) idle state or an RRC inactive state.5.The method of claim 4,wherein the notification message is received from the first relay UE, if a first serving cell of the first relay UE is different from a second serving cell of the second relay UE.6.The method of claim 4,wherein a length of a timer associated with the multi-hop sidelink is identified based on a multi-hop count of the multi-hop sidelink and time information.7.A first relay user equipment (UE) in a wireless communication system, the first relay UE comprising:at least one transceiver;at least one processor communicatively coupled to the at least one transceiver; andat least one memory, communicatively coupled to the at least one processor, storing instructions executable by the at least one processor individually or in any combination to cause the first relay UE to:perform a relay reselection,transmit, to the second relay UE, a notification message for a multi-hop sidelink based on the relay reselection, the notification message including a relay reselection indication,wherein the first relay UE relays communication between the second relay UE and another relay UE,wherein the second relay UE relays communication between the first relay UE and a remote UE,wherein the first relay UE is in a radio resource control (RRC) idle state or an RRC inactive state.8.The first relay UE of claim 7,wherein the notification message is transmitted to the second relay UE, if a first serving cell of the first relay UE is different from a second serving cell of the second relay UE.9.The first relay UE of claim 7,wherein a length of a timer associated with the multi-hop sidelink is identified based on a multi-hop count of the multi-hop sidelink and time information.10.A second relay user equipment (UE) in a wireless communication system, the second relay UE comprising:at least one transceiver;at least one processor communicatively coupled to the at least one transceiver; andat least one memory, communicatively coupled to the at least one processor, storing instructions executable by the at least one processor individually or in any combination to cause the second relay UE to:receive, from a first relay UE, a notification message for a multi-hop sidelink associated with a relay reselection, the notification message including a relay reselection indication,wherein the first relay UE relays communication between the second relay UE and another relay UE,wherein the second relay UE relays communication between the first relay UE and a remote UE,wherein the first relay UE is in a radio resource control (RRC) idle state or an RRC inactive state.11.The second relay UE of claim 10,wherein the notification message is received from the first relay UE, if a first serving cell of the first relay UE is different from a second serving cell of the second relay UE.12.The second relay UE of claim 10,wherein a length of a timer associated with the multi-hop sidelink is identified based on a multi-hop count of the multi-hop sidelink and time information.

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