Node device in communication system and method performed thereof

Abstract

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. The present disclosure provides a method performed by a remote user equipment (UE) in a wireless communication system. The method comprises receiving, from a first relay UE, a PC5 radio resource control (RRC) message indicating a PC5 radio link failure; and triggering a relay reselection based on the PC5 radio link failure, wherein the PC5 RRC message includes information related to the relay reselection of the remote UE.

Description

NODE DEVICE IN COMMUNICATION SYSTEM AND METHOD PERFORMED THEREOF

[0001] The application relates to the field of communication, and more particularly, to a method performed by a first node in a communication system, a method performed by a second node in a communication system, a method performed by a third node in a communication system, a method performed by a fourth node in a communication system, a method performed by a eighth node in a communication system, a first node, a second node, a third node, a fourth node and a eighth node.

[0002] Fifth generation (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 6 gigahertz (GHz)” bands such as 3.5GHz, but also in “Above 6GHz” bands referred to as millimeter wave (mmWave) including 28GHz and 39GHz. In addition, it has been considered to implement sixth generation (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 multi input multi output (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 BandWidth Part (BWP), new channel coding methods such as a Low Density Parity Check (LDPC) 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 Vehicle-to-everything (V2X) 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, New Radio Unlicensed (NR-U) aimed at system operations conforming to various regulation-related requirements in unlicensed bands, new radio (NR) user equipment (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, Integrated Access and Backhaul (IAB) 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 Dual Active Protocol Stack (DAPS) handover, and two-step random access for simplifying random access procedures (2-step random access channel (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 Augmented Reality (AR), Virtual Reality (VR), Mixed Reality (MR) 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 Orbital Angular Momentum (OAM), and Reconfigurable Intelligent Surface (RIS), 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 Artificial Intelligence (AI) 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] 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”.

[0009] 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.

[0010] With the gradual maturation of the 5G commercial network (NR: New Radio access network), research and standardization work on non-terrestrial network (NTN) technology has been carried out.

[0011] The technical problem to be solved by the present disclosure is to provide improved communication method in a wireless communication system.

[0012] According to an aspect of the present disclosure, a method performed by a remote user equipment (UE) in a wireless communication system is provided. The method comprises receiving, from a first relay UE, a PC5 radio resource control (RRC) message indicating a PC5 radio link failure and triggering a relay reselection based on the PC5 radio link failure, wherein the PC5 RRC message includes information related to the relay reselection of the remote UE.

[0013] According to an aspect of the present disclosure, a method performed by a first relay user equipment (UE) in a wireless communication system is provided. The method comprises identifying a PC5 radio link failure and transmitting, to a remote UE, a PC5 radio resource control (RRC) message indicating the PC5 radio link failure, wherein the PC5 RRC message includes information related to the relay reselection of the remote UE, and wherein a relay reselection is triggered based on the PC5 radio link failure.

[0014] According to an aspect of the present disclosure, a remote user equipment (UE) in a wireless communication system is provided. The remote UE comprises at least one transceiver and at least one processor coupled with the at least one transceiver and configured to receive, from a first relay UE, a PC5 radio resource control (RRC) message indicating a PC5 radio link failure, and to trigger a relay reselection based on the PC5 radio link failure, wherein the PC5 RRC message includes information related to the relay reselection of the remote UE.

[0015] According to an aspect of the present disclosure, a first relay user equipment (UE) in a wireless communication system is provided. The first relay UE comprises at least one transceiver and at least one processor coupled with the at least one transceiver and configured to identify a PC5 radio link failure; and to transmit, to a remote UE, a PC5 radio resource control (RRC) message indicating the PC5 radio link failure, wherein the PC5 RRC message includes information related to the relay reselection of the remote UE, and wherein a relay reselection is triggered based on the PC5 radio link failure.

[0016] According to an aspect of the present disclosure, there is provided a method performed by a second node in a communication system, the method comprising: receiving first information from a sixth node, wherein the first information includes ninth information associated with a hop count of the sixth node; determining whether the second node is able to act as a relay user equipment based on the ninth information and information on a maximum number of relay user equipment allowed on a communication link from a base station to a remote user equipment; wherein the sixth node is a next hop user equipment of the second node.

[0017] According to the method performed by the second node in a communication system provided by the present disclosure, wherein the first information further includes information on the maximum number.

[0018] According to the method performed by the second node in a communication system provided by the present disclosure, wherein the determining whether the second node is able to act as the relay user equipment based on the ninth information and information on the maximum number of relay user equipment allowed on the communication link from the base station to the remote user equipment comprises: in the case that the hop count is less than or equal to the maximum number and the hop count is equal to zero or one, determining that the second node is not able to act as the relay user equipment; in the case that the hop count is greater than zero or one, determining that the second node is able to act as the relay user equipment; or in the case that the hop count is less than or equal to the maximum number, decreasing the hop count by one as an updated hop count; in the case that the updated hop count is equal to zero or negative one, determining that the second node is not able to act as the relay user equipment; in the case that the updated hop count is greater than zero or negative one, determining that the second node is able to act as the relay user equipment; or in the case that the hop count is greater than or equal to the maximum number, determining that the second node is not able to act as the relay user equipment; in the case that the hop count is less than the maximum number, determining that the second node is able to act as the relay user equipment; or adding one to the hop count as an updated hop count; in the case that the updated hop count is greater than or equal to the maximum number or the maximum number plus one, determining that the second node is not able to act as a relay user equipment; in the case that the updated hop count is less than the maximum count or the maximum count plus one, determining that the second node is able to act as a relay user equipment.

[0019] According to the method performed by the second node in a communication system provided by the present disclosure, wherein the method further comprises: transmitting nineteenth information to a fifth node, wherein the nineteenth information includes a hop count updated based on the hop count included in the first information, wherein the fifth node is the previous hop user equipment of the second node.

[0020] According to the method performed by the second node in a communication system provided by the present disclosure, wherein the method further comprises: triggering, by the second node, reselection of the relay user equipment based on a first situation / condition; or, triggering, by the second node, the selection of relay user equipment based on a second situation / condition; wherein the first situation / condition includes at least one of: a PC5 signal strength between the second node and the sixth node being below a first threshold; the sixth node performing cell reselection; the sixth node performing reselection of the relay user equipment; the sixth node occurring a handover; the sixth node occurring an air interface radio link failure; a PC5 radio link failure occurring in PC5 between the sixth node and a ninth node, wherein the ninth node is a next hop user equipment of the sixth node; the sixth node occurring a radio resource control connection setup failure or resume failure; the second node detecting that a radio link failure occurs in PC5 with the sixth node; wherein the second situation / condition includes at least one of: a Uu signal strength of a current serving cell of the second node being lower than a second threshold.

[0021] According to the method performed by the second node in a communication system provided by the present disclosure, wherein the method further comprises: receiving sixth information from a fourth node, wherein the sixth information includes at least one of: a remote user equipment related identification / ID; a remote user equipment radio bearer identification / ID; an identification / ID associated with a previous hop relay user equipment; a first egress radio link control (RLC) channel identification / ID associated with an RLC channel between the second node and a previous hop relay user equipment of the second node; a second egress RLC channel identification / ID associated with an RLC channel between the second node and a next hop relay user equipment of the second node.

[0022] According to the method performed by the second node in a communication system provided by the present disclosure, wherein the first egress RLC channel identification / ID and the second egress RLC channel identification / ID are PC5 RLC channel identifications / IDs.

[0023] According to the method performed by the second node in a communication system provided by the present disclosure, herein the method further comprises: transmitting seventeenth information to a fifth node, wherein the seventeenth information includes at least one of: information related to re-establishment and / or relay reselection of the sixth node; information related to a next hop or next-multi-hop relay user equipment of the sixth node; the fifth node is a previous hop user equipment of the second node.

[0024] According to the method performed by the second node in a communication system provided by the present disclosure, wherein the method further comprises: transmitting an eighteenth information to the sixth node, wherein the eighteenth information includes information related to a system information block request or paging of a previous hop or previous-multi-hop relay user equipment of the sixth node or remote user equipment.

[0025] According to another aspect of the present disclosure, there is provided a method performed by a first node in a communication system, the method comprising: receiving tenth information from a fourth node, wherein the tenth information includes information about a maximum number of relay user equipment allowed on a communication link from a base station to a remote user equipment; transmitting twentieth information to a second node, wherein the twentieth information includes information associated with a hop count of a first node.

[0026] According to the method performed by the first node in a communication system provided by the present disclosure, wherein the maximum number is a predefined value and is stored in the first node device.

[0027] According to the method performed by the first node in a communication system provided by the present disclosure, wherein the hop count is the maximum number or the maximum number minus one; or the hop count is zero or one.

[0028] According to the method performed by the first node in a communication system provided by the present disclosure, wherein the method further comprises: receive eleventh information from the fourth node, wherein the eleventh information includes at least one of: a remote user equipment related identification / ID; a remote user equipment radio bearer identification / ID; an identification / ID associated with a previous hop relay user equipment; a third egress radio link control (RLC) channel identification / ID associated with an RLC channel between the first node and a previous hop relay user equipment of the first node; a fourth egress RLC channel identification / ID associated with an RLC channel between the first node and the fourth node.

[0029] According to the method performed by the first node in a communication system provided by the present disclosure, wherein the third egress RLC channel identification / ID is a PC5 RLC channel identification / ID and the fourth egress RLC channel identification / ID is a Uu RLC channel identification / ID.

[0030] According to another aspect of the present disclosure, there is provided a method performed by a third node in a communication system, the method including: receiving twelfth information from a tenth node, wherein the twelfth information includes fifteenth information associated with a hop count of the tenth node; selecting or reselecting a relay user equipment based on the twelfth information and information about a maximum number of relay user equipment allowed on a communication link from a base station to a remote user equipment.

[0031] According to the method performed by the third node in a communication system provided by the present disclosure, wherein the method further comprises: triggering, by the third node, reselection of the relay user equipment based on the third situation / condition; wherein the third situation / condition includes at least one of: a PC5 radio link failure occurring between the tenth node and an eleventh node, wherein the eleventh node is a next hop user equipment of the tenth node; performing, by the tenth node, the reselection of the relay user equipment.

[0032] According to the method performed by the third node in a communication system provided by the present disclosure, wherein the method further includes: receiving sixteenth information from a fourth node, wherein the sixteenth information includes at least one of the following: a remote user equipment related identification / ID; a remote user equipment radio bearer identification / ID; an identification / ID associated with a previous hop relay user equipment; a fifth egress radio link control (RLC) channel identification / ID associated with a RLC channel between the second node and the third node.

[0033] According to the method performed by the third node in a communication system provided by the present disclosure, the fifth egress radio link control (RLC) channel identification / ID is a PC5 RLC channel identification / ID.

[0034] According to another aspect of the present disclosure, there is provided a method performed by a fourth node in a communication system, the method comprising: transmitting second information to an eighth node, wherein the second information includes at least one of: information related to a number of links between a third node to a first node; information related to a number of relay user equipment between the third node to the first node or the fourth node; receiving third information from the eighth node, wherein the third information includes information related to a PC5 Quality of Service associated with each link between the third node to the first node.

[0035] According to the method performed by the fourth node in a communication system provided by the present disclosure, wherein the method further comprises: transmitting fifth information and / or fourth information to a seventh node, wherein the fourth information includes information related to a relay user equipment identification / ID and information related to a PC5 Quality of Service; wherein the fifth information includes information related to a PC5 radio link control RLC channel.

[0036] According to the method performed by the fourth node in a communication system provided by the present disclosure, wherein the fourth node is a base station or a centralized unit of a base station.

[0037] According to another aspect of the present disclosure, there is provided a method performed by an eighth node in a communication system, the method comprising: receiving second information from a fourth node, wherein the second information includes at least one of: information related to a number of links between a third node to a first node; information related to a number of relay user equipment between the third node to the first node or the fourth node; transmitting third information to the fourth node, wherein the third information includes information related to a PC5 Quality of Service associated with each link between the third node to the first node.

[0038] According to another aspect of the present disclosure, there is provided a first node including a transceiver configured to transmit and receive signals with the outside; and a controller configured to control the transceiver to perform the method performed by the first node.

[0039] According to another aspect of the present disclosure, there is provided a second node including a transceiver configured to transmit and receive signals with the outside; and a controller configured to control the transceiver to perform the method performed by the second node.

[0040] According to another aspect of the present disclosure, there is provided a third node including a transceiver configured to transmit and receive signals with the outside; and a controller configured to control the transceiver to perform the method performed by the third node.

[0041] According to another aspect of the present disclosure, there is provided a fourth node including a transceiver configured to transmit and receive signals with the outside; and a controller configured to control the transceiver to perform the method performed by the fourth node.

[0042] According to another aspect of the present disclosure, there is provided a fifth node including a transceiver configured to transmit and receive signals with the outside; and a controller configured to control the transceiver to perform the method performed by the fifth node.

[0043] According to another aspect of the present disclosure, there is provided a non-transitory computer-readable recording medium having stored thereon a program which, when being executed by a computer, performs any of the above methods.

[0044] According to various embodiments of present disclosure improved communication methods can be provided.

[0045] Figure 1 is an exemplary system architecture in accordance with various embodiments of the present disclosure.

[0046] Figure 2A, 2B, 2C are an exemplary architecture of a base station according to various embodiments of the present disclosure.

[0047] Figure 3A is a scenario in which there are two relay user equipment between a base station and a remote user equipment according to various embodiments of the present disclosure.

[0048] Figure 3B illustrates another scenario with three relay user equipment between a base station and a remote user equipment according to various implementations of the present disclosure.

[0049] Figure 4A illustrates a method of selecting or reselecting a relay user equipment according to various embodiments of the present disclosure.

[0050] Figure 4B illustrates a method of node interaction / coordination in accordance with various embodiments of the present disclosure.

[0051] Figure 4C illustrates another method of node interaction / coordination in accordance with various embodiments of the present disclosure.

[0052] Figure 4D illustrates yet another method of node interaction / coordination in accordance with various embodiments of the present disclosure.

[0053] Figure 4E illustrates yet another method of node interaction / coordination in accordance with various embodiments of the present disclosure.

[0054] Figure 4F illustrates yet another method of node interaction / coordination in accordance with various embodiments of the present disclosure.

[0055] Figure 4G illustrates yet another method of node interaction / coordination according to various embodiments of the present disclosure.

[0056] Figure 4HA and 4HB illustrate yet another method of node interaction / coordination according to various embodiments of the present disclosure.

[0057] Figure 5 is a block diagram of a node device according to an embodiment of the present disclosure.

[0058] In order to make the objectives, technical solutions and advantages of the embodiments of the present disclosure, a clearly and complete description will be made with respect to the technical solutions of the embodiments of the present disclosure, in conjunction with the accompanying drawings of the embodiments of the present disclosure. Apparently, the described embodiments are a part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary skilled in the art without creative labor belong to the protection scope of the present disclosure. In the present disclosure, elements expressed in the singular form may also be understood to be expressed in the plural form. Similar words such as singular forms “a”, “an” or “the” do not express a limitation of quantity, but express the existence of at least one of the referenced item, unless the context clearly dictates otherwise. For example, reference to “a component surface” includes reference to one or more of such surfaces.

[0059] Before undertaking the DETAILED DESCRIPTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The term “couple” and its derivatives refer to any direct or indirect communication between two or more elements, whether those elements are in physical contact with one another. The terms “transmit,” “receive,” and “communicate,” as well as derivatives thereof, encompass both direct and indirect communication. The terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation. The term “or” is inclusive, meaning and / or. The phrase “associated with,” as well as derivatives thereof, means to include, be included within, interconnect to or with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, have a relationship to or with, or the like. The term “controller” means any device, system or part thereof that controls at least one operation. Such a controller may be implemented in hardware or a combination of hardware and software and / or firmware. The function associated with any particular controller may be centralized or distributed, whether locally or remotely. The phrase “at least one of,” when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one item in the list may be needed. For example, “at least one of: A, B, and C” includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C. For example, "at least one of A, B, or C " includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C.

[0060] In addition, various functions described below can be implemented or supported by one or more computer programs, each of which is formed by computer-readable program code and embodied in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, procedures, functions, objects, classes, instances, related data or parts thereof appropriate for implementation in suitable computer-readable program code. The phrase "computer readable program code" includes any type of computer code, including source code, objective code and executable code. The phrase "computer readable medium" includes any type of medium that can be accessed by a computer, such as Read-Only Memory (ROM), Random Access Memory (RAM), hard disk drive, compact disk (CD), digital video disk (DVD) or any other type of memory. A "non-transitory" computer-readable medium excludes wired, wireless, optical or other communication links that transfer transitory electrical or other signals. A non-transitory computer-readable medium includes a medium in which data can be stored permanently and a medium in which data can be stored and rewritten later, such as rewritable optical disks or erasable memory devices.

[0061] The terms used herein to describe the embodiments of the present application is not intended to limit and / or define the scope of the present application. For example, unless otherwise defined, the technical or scientific terms used in the present disclosure should have ordinary meanings as understood by ordinary skilled in the art to which the present application belongs.

[0062] It should be understood that "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Unless clearly indicated otherwise in the context, similar words such as "a", "an", "the" and the like in the singular form do not indicate a quantitative limitation, but indicate the existence of at least one.

[0063] As used herein, any reference to "one example" or "an example", "one embodiment" or "an embodiment" means that a particular element, feature, structure or characteristic described in conjunction with the embodiment is included in at least one embodiment. The appearances of the phrases "in one embodiment" or "in one example" in different places in the specification are not necessarily all referring to the same embodiment.

[0064] As used herein, "a part of" a certain thing means "at least some of" this thing, so it may mean being less than the entirety thereof or being the entirety thereof. Therefore, "a part of" the thing includes the whole thing as a special case, that is, an example in which the whole thing is a part of the thing.

[0065] It will be further understood that words such as "include", "contain" or the like means that the elements or objects appearing preceding the word encompass the elements or objects listed behind the word as well as their equivalents, without excluding other elements or objects. Words such as "connect", "interconnect" or the like are not limited to physical or mechanical connections, but may include electrical connection, whether direct or indirect. "Up", "Down", "Left" and "Right" are only used to indicate relative positional relationships. When the absolute position of the described object changes, accordingly, the relative positional relationship may change as well.

[0066] The various embodiments discussed below for describing the principle of the present disclosure in this patent document are for illustration only, and should not be construed as limiting the scope of the present disclosure in any way. Those skilled in the art will understand that the principle of the present disclosure may be implemented in any suitably arranged wireless communication system. For example, although the following detailed description of the embodiments of the present disclosure will focus on LTE and 5G communication systems, those skilled in the art can understand that the main points of the present disclosure can also be applied to other communication systems with similar technical backgrounds and channel formats, with slight modifications and basically without departing from the scope of the present disclosure. The schemes of the embodiments of the present application may be applied to various communication systems. For example, the communication systems may include a Global System for Mobile communications (GSM) system, a Code Division Multiple Access (CDMA) system, a Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE frequency Division DUplex (FDD) system, LTE time Division DUplex (TDD), Universal Mobile Telecommunication System (UMTS), worldwide interoperability for microwave access (WiMAX) communication system, fifth generation (5th generation, 5G) system or New Radio (NR), etc. In addition, the schemes of the embodiments of the present application may be applied to future-oriented communication technologies. In addition, the schemes of the embodiments of the present application may be applied to future-oriented communication technologies.

[0067] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure as defined by the claims and their equivalents. The description includes various specific details to assist in that understanding but should be regarded as exemplary only. Accordingly, the ordinary skilled in the art will recognize that various changes and modifications to the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and structures may be omitted for clarity and conciseness.

[0068] The terms and wordings used in the following description and claims are not limited to the bibliographical meanings, but are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustration purpose only, but not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.

[0069] It should be understood that the singular forms “a,” “an,” and “the” include plural referents, unless clearly indicated otherwise in the context. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces.

[0070] The term “include” or “may include” refers to the existence of a corresponding disclosed function, operation or component which can be used in various embodiments of the present disclosure, and does not limit the existence of one or more additional functions, operations, or components. The terms “include” and / or “have” may be construed to represent certain feature, numbers, steps, operations, constituent elements, components or combinations thereof, but may not be construed to exclude the possibility of existence of one or more other feature, numbers, steps, operations, constituent elements, components or combinations thereof.

[0071] The term “or” used in various embodiments of the present disclosure includes any of the listed terms or all combinations thereof. For example, “A or B” may include A, may include B, or may include both A and B.

[0072] Unless defined differently, all terms used in the present disclosure, including technical or scientific terms, have the same meanings as those understood by the skilled in the art as described in the present disclosure. Common terms as defined in a dictionary are to be interpreted to have meanings consistent with the context in the relevant technical field o, and are not to be interpreted ideally or excessively, unless clearly defined as such in the present disclosure.

[0073] Figures discussed below and various embodiments for describing the principle of the present disclosure in this patent document are only for illustration, and should not be interpreted as limiting the scope of the present disclosure in any way. Those skilled in the art will understand that the principle of the present disclosure may be implemented in any suitably arranged system or device.

[0074] Figure 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.

[0075] 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.

[0076] In NR system, in order to support network function virtualization, more efficient resource management and scheduling, a base station (gNB / ng-eNB) that provides a radio network interface for user equipment (UE) can be further divided into a centralized unit gNB-CU / ng-eNB-CU (gNB central unit / ng-eNB central unit) and a distribution unit gNB-DU / ng-eNB-DU (gNB distribution unit / ng-eNB distribution unit) (abbreviated as CU and DU in the present invention), as shown in Figure 2(a). gNB-CU has radio resource control (RRC), service data adaptation protocol (SDAP) and packet data convergence protocol (PDCP) protocols, etc, while ng-eNB-CU has RRC and PDCP layers. gNB-DU / ng-eNB-DU has radio link control protocol (RLC), medium access control (MAC) and physical layer, etc. There is a standardized public interface F1 between gNB-CU and gNB-DU, and a standardized public interface W1 between ng-eNB-CU and ng-eNB-DU. The F1 interface is divided into control plane F1-C and user plane F1-U. The transport network layer of F1-C is based on IP transport. In order to transmit signaling more reliably, SCTP (stream control transmission protocol) protocol is added to IP. The protocol of the application layer is F1AP (F1 Application Protocol, F1 Application Protocol / F1 Interface Application Protocol). SCTP can provide reliable application layer message transmission. The transport layer of F1-U (F1-User, user plane of F1) is UDP / IP, and GTP-U (GPRS tunneling protocol for the user plane) is used to carry user plane protocol data unit PDU above UDP / IP. Further, for gNB-CU, as shown in Figure 2(b), gNB-CU can include gNB-CU-CP (the control plane part of the centralized unit of the base station) and gNB-CU-UP (the user plane part of the centralized unit of the base station). gNB-CU-CP includes the function of the control plane of the base station and has RRC and SDAP protocol layers, and gNB-CU-UP includes the function of the user plane of the base station and has SDAP and PDCP protocol layers. gNB-CU-CP and gNB-CU-UP are standardized public interfaces E1, and the protocol is E1AP. The interface between the control plane part of the centralized unit of the base station and the distribution unit of the base station is F1-C interface, that is, the control plane interface of F1, and the interface between the user plane part of the centralized unit of the base station and the distribution unit of the base station is F1-U interface, that is, the user plane interface of F1. In addition, in the NR system, the base station providing the E-UTRA user plane and control plane which accesses the 5G core network is called ng-eNB. In order to support virtualization, such a base station (ng-eNB) can also be further divided into a centralized unit ng-eNB-CU (gNB central unit / ng-eNB central unit) and a distribution unit ng-eNB-DU (gNB distribution unit / ng-eNB distribution unit) (abbreviated as CU and DU in the present invention), as shown in Figure 2(c). ng-eNB-CU has RRC and PDCP layers. gNB-DU / ng-eNB-DU has radio link control protocol (RLC), medium access control (MAC) and physical layer,etc. There is a standardized public interface W1 between ng-eNB-CU and ng-eNB-DU. W1 interface is divided into control plane W1-C and user plane W1-U. The transport network layer of W1-C is based on IP transport. In order to transmit signaling more reliably, SCTP protocol is added to IP. The protocol of the application layer is W1AP. The transport layer of W1-U is UDP / IP, and GTP-U is used to carry user plane protocol data unit PDU above UDP / IP.

[0077] Exemplary embodiments of the present disclosure are further described below with reference to the accompanying drawings.

[0078] The text and drawings are provided as examples only to help understand the present disclosure. They should not be construed as limiting the scope of the present disclosure in any way. Although certain embodiments and examples have been provided, based on the disclosure herein, it is obvious to those skilled in the art that changes can be made to the illustrated embodiments and examples without departing from the scope of this disclosure.

[0079] Before introducing the specific content, some assumptions and some definitions of the present invention are given below.

[0080] - The message names in the present invention are only examples, and other message names can be used.

[0081] - The "first" and "second" included in the message name of the present invention are only examples of messages and do not represent the execution order. In addition, the words "first" and "second" appearing in front of the message or information mentioned in the claim are not necessarily exactly the same as the words "first" and "second" appearing in front of the message or information mentioned in the specification.

[0082] - Detailed description of steps irrelevant to the present invention is omitted in the present invention.

[0083] - In the present invention, the steps in each procedure can be executed in combination with each other or independently. The execution steps of each process are only examples, and other possible execution orders are not excluded.

[0084] - In the present invention, the base station may be a 5G base station (such as gNB, ng-eNB), a 4G base station (such as eNB), a 6G base station or other types of access nodes.

[0085] - In the present invention, data transmission refers to the reception or transmission of data.

[0086]

[0087] Nodes involved in the present invention:

[0088] - First Relay user equipment (UE)

[0089] - Second relay user equipment

[0090] - Last relay user equipment

[0091] - Remote User Equipment (Remote UE)

[0092] - A base station, or a centralized unit of a base station, or a control plane part of a centralized unit of a base station

[0093] - A distribution unit of a base station

[0094] - A core network, or an Access and Mobility Management Function (AMF) (for simplicity of description, the description will be collectively used as 'core network' below)

[0095] - The "tenth node" may correspond to the "first relay user equipment"; the "first node" may correspond to the "last relay user equipment"; the "third node" may correspond to the "remote user equipment"; the "fourth node" may correspond to the "a base station or a centralized unit of the base station"; the "second node" may correspond to the "second relay user equipment"; the "seventh node" may correspond to the "a distribution unit of the base station"; the "eighth node" may correspond to the "a core network node";

[0096] - The Xth node is the next hop relay user equipment of the Yth node may be used interchangeably with the following: the Xth node is the next hop relay user equipment of the Yth node along the direction from the remote user equipment to the base station; or the Xth node is the previous hop relay user equipment of the Yth node along the direction from the base station to the remote user equipment.

[0097] - The Xth node is the previous hop relay user equipment of the Yth node may be used interchangeably with the following: the Xth node is the previous hop relay user equipment of the Yth node along the direction from the remote user equipment to the base station; or the Xth node is the next hop relay user equipment of the Yth node along the direction from the base station to the remote user equipment.

[0098] The selection or reselection of relay user equipment of the Xth node can be triggered by the remote user equipment or the relay user equipment. Various triggering situation / conditions will be described in detail below with reference to the scenarios of Figures 3A and 3B.

[0099] (1) The situation / condition where the remote user equipment triggers reselection of the relay user equipment (also called the third situation / condition) includes at least one of the following situation / conditions:

[0100] - PC5 radio link failure, and the PC5 radio link failure is indicated to the remote user equipment by the first relay user equipment through a PC5 radio resource control related message. It should be pointed out that the PC5 radio link failure refers to a radio link failure between the relay user equipment of this hop and the relay user equipment of the next hop; In one embodiment, it refers to that a radio link failure occurs between the first relay user equipment and the second relay user equipment and / or the last relay user equipment.

[0101] - Relay user equipment reselection, wherein the relay user equipment reselection is indicated to the remote user equipment by the first relay user equipment through a PC5 radio resource control related message. It should be pointed out that the relay user equipment reselection refers to the relay user equipment of this hop reselecting the relay user equipment of the next hop. In one implementation, it refers to that the first relay user equipment reselects to another second relay user equipment and / or the last relay user equipment.

[0102] (2) The situation / condition where the relay user equipment triggers the selection of the relay user equipment (also called the second situation / condition), including at least one of the following situation / conditions:

[0103] - The Uu air interface signal quality of the current serving cell of the relay user equipment is lower than a configured signal quality threshold (also called a second threshold). It should be pointed out that the Uu air interface signal quality of the current serving cell of the relay user equipment refers to the air interface signal quality when the relay user equipment is directly connected to the current serving cell.

[0104] - An upper layer indication of the relay user equipment.

[0105] (3) The situation / condition in which the relay user equipment triggers reselection of the relay user equipment (also called the first situation / condition) includes at least one of the following situation / conditions:

[0106] - The PC5 signal quality of the relay user equipment is below a configured signal quality threshold (which may also be referred to as a first threshold). It should be pointed out that the PC5 signal quality of the relay user equipment refers to the PC5 signal quality between this relay user equipment and the current next hop relay user equipment.

[0107] - Cell reselection, wherein the cell reselection is indicated by the relay user equipment of the next hop to the relay user equipment of this hop through a PC5 radio resource control related message. It should be pointed out that the cell reselection refers to the next hop relay user equipment performing cell reselection. In one embodiment, it refers to that the last relay user equipment performs cell reselection and indicates it to the first relay user equipment (Figure 3A) or the second relay user equipment (Figure 3B) through PC5.

[0108] - Relay user equipment reselection, wherein the relay user equipment reselection is indicated to the relay user equipment of this hop by the relay user equipment of the next hop through a PC5 radio resource control related message. It should be pointed out that the relay user equipment reselection refers to the relay user equipment of the next hop reselecting the relay user equipment of the next two hops. In one implementation, as shown in Figure 3B, it refers to that the second relay user equipment reselects to another last relay user equipment and indicates it to the first relay user equipment through PC5.

[0109] - Handover, wherein the handover is indicated by the relay user equipment of the next hop to the relay user equipment of this hop through a PC5 radio resource control related message. It should be pointed out that the handover refers to that the handover has occurred in the relay user equipment of the next hop. In one implementation, that is, the handover has occurred in the last relay user equipment and is indicated to the first relay user equipment (as shown in Figure 3A) or the second relay user equipment (as shown in Figure 3B) through PC5. In another implementation, the handover has occurred in the second relay user equipment and is indicated to the first relay user equipment through the PC interface (Figure 3B).

[0110] - The air interface radio link failure, wherein the air interface radio link failure is indicated by the relay user equipment of the next hop to the relay user equipment of this hop through a PC5 radio resource control related message. It should be pointed out that the air interface radio link failure refers to that an air interface radio link failure has occurred in the relay user equipment of the next hop. In one implementation, an air interface radio link failure has occurred in the last relay user equipment and is indicated to the first relay user equipment (as shown in Figure 3A) or the second relay user equipment (as shown in Figure 3B) through PC5.

[0111] - PC5 radio link failure, wherein the PC5 radio link failure is indicated by the relay user equipment of the next hop to the relay user equipment of this hop through a PC5 radio resource control related message. It should be pointed out that the PC5 radio link failure refers to that PC5 radio link failure has occurred between the relay user equipment of the next hop and the PC5 of the relay user equipment of the next two hops. In one implementation, that is, a PC5 radio link failure has occurred between the second relay user equipment and the last relay user equipment, the second relay user equipment indicates it to the first relay user equipment through PC5 (as shown in Figure 3B).

[0112] - The radio resource control connection setup failure or resume failure, wherein the radio resource control connection setup failure or resume failure is indicated by the relay user equipment of the next hop to the relay user equipment of the this hop through the PC5 radio resource control related message. It should be pointed out that the radio resource control connection setup failure or resume failure refers to that the radio resource control connection setup failure or resume failure has occurred in the relay user equipment of the next hop. In one implementation, that is, the radio resource control connection setup failure or resume failure has occurred in the last relay user equipment, and is indicated it to the first relay user equipment (as shown in Figure 3A) or the second relay user equipment (as shown in Figure 3B) through PC5. In another implementation, the radio resource control connection setup failure or resume failure has occurred in the second relay user equipment and is indicated it to the first relay user equipment through the PC interface (as shown in Figure 3B).

[0113] - The relay user equipment detects that a radio link failure occurs in PC5 with the relay user equipment of the next hop.

[0114] - An upper layer indication of the relay user equipment.

[0115] Through the above different trigger conditions, it is ensured that remote user equipment with communication needs can select or reselect to the appropriate relay user equipment. On the other hand, it can also be ensured that the relay user equipment of this hop on the path can select or reselect to the appropriate next hop relay user equipment, thereby ensuring the communication of the remote user equipment.

[0116] Figure 4A illustrates a method of selecting or reselecting a relay user equipment according to one embodiment of the present disclosure. As illustrate in Figure 4A,

[0117] The first node transmits first information for relay user selection or reselection to the second node.

[0118] The first information includes at least one of the following information:

[0119] - information related to a hop count of relay user equipment (may also be referred to as seventh information or thirteenth information).

[0120] - indication information related to the selection or reselection of the relay user equipment (may also be referred to as eighth information).

[0121] The information related to the hop count of relay user equipment includes at least one of the following information:

[0122] - hop count related information (may also be referred to as ninth information or fifteenth information or nineteenth information or twentieth information).

[0123] - information on an allowed maximum hop count of the relay user equipment.

[0124] It should be pointed out that if the first node is a base station, the second node is the last relay user equipment, then the first information may also be called tenth information. If the first node is the last relay user equipment, the second node is the second relay user equipment (as shown in Figure 3B) or the first relay user equipment (as shown in Figure 3A) or the remote user equipment. If the first node is the second relay user equipment, the second node is the first relay user equipment or the remote user equipment. If the first node is the first relay user equipment, the second node is the remote user equipment. In addition, the first information may be called twelve information.

[0125] If the first node is a base station, the first information may be included in a Radio Resource Control (RRC) message, such as an RRC reconfiguration message, a system information, etc., or may also be included in other RRC messages.

[0126] If the first node is a relay user equipment, the first information may be included in a PC5 radio resource control (PC5-RRC) message, such as a sidelink RRC reconfiguration message, a sidelink notification message, etc., or may be included in other PC5-RRC messages; or may also be included in a PC5 Signaling (PC5-S) message; or may be included in PC5 discovery (PC5-D) messages, such as Discovery Announcement messages, Discovery Response messages, etc., or may be included in other PC5-D messages.

[0127] In one embodiment: the last relay user equipment transmits the first information including the indication information related to the selection or reselection of the relay user equipment to the second node (if it is not the last relay user equipment, the indication information related to the selection or reselection of the relay user equipment cannot be included in the first information). After receiving the first information from the first node, the second node may determine whether it can become a relay user equipment based on whether the indication information related to the selection or reselection of the relay user equipment is included. If the first information includes the indication information related to the selection or reselection of the relay user equipment, the second node is able to act as the first relay user equipment; If the first information does not include the indication information related to the selection or reselection of the relay user equipment, the second node is not able to act as the relay user equipment, but can communicate with the network as a remote user equipment.

[0128] For the information on an allowed maximum hop count of the relay user equipment, in one implementation, the base station transmits it to the last relay user equipment through the first information (at this time, the first information transmitted by the base station may also be called tenth information); in another embodiment, it is a fixed value that is predefined in the network and stored in the user equipment.

[0129] For the hop count related information of the last relay user equipment, in one implementation: the first information transmitted by the base station to the last relay user equipment (at this time, the first information transmitted by the base station may also be called the tenth information) contains the information on an allowed maximum hop count of the relay user equipment; after the last relay user equipment receives the information on an allowed maximum hop count of the relay user equipment, the information on an allowed maximum hop count of the relay user equipment or the information on an allowed maximum hop count of the relay user equipment minus one is taken as the hop count information of the last relay user equipment.

[0130] In another implementation: the last relay user equipment stores the predefined information on an allowed maximum hop count of the relay user equipment. The last relay user equipment uses the information on an allowed maximum hop count of the relay user equipment or the information on an allowed maximum hop count of the relay user equipment minus one as the hop information of the last relay user equipment.

[0131] In another implementation: the last relay user equipment uses zero or one as the hop count information of the last relay user equipment.

[0132] When the last relay user equipment transmits the first information, the hop count information of the last relay user equipment is transmitted to the second node as hop count related information.

[0133] Updating the hop count related information. In one implementation, the second node subtracts the received hop count related information by one as the updated hop count related information; when the second node subsequently transmits the first information as the first node, the updated hop count related information is transmitted to other second nodes.

[0134] in another embodiment, the second node adds one to the received hop count related information as updated hop count related information; when the second node subsequently transmits the first information as the first node, the updated hop count related information is transmitted to other second nodes.

[0135] In one embodiment, when the second node receives the hop count related information, in one implementation: the second node first determines the hop count related information. If the received hop count related information is equal to zero or one, the second node is not able to act as a relay user equipment; if the received hop count related information is greater than zero or one, the second node is able to act as a relay user equipment.

[0136] In another embodiment, the second node may also subtract the received hop count related information by one as updated hop count related information, and when the second node subsequently transmits the first information as the first node, the updated hop count related information is transmitted to other second nodes.

[0137] In another implementation, the second node first determines the hop count related information. If the received hop count related information is greater than the information on an allowed maximum hop count of the relay user equipment contained in the first information, the second node is not able to act as a relay user equipment; if the received hop count related information is less than the information on an allowed maximum hop count of the relay user equipment contained in the first information, the second node is able to act as a relay user equipment.

[0138] In another implementation, the second node may also add one to the received hop count related information as updated hop count related information. When the second node subsequently transmits the first information as the first node, the updated hop count related information is transmitted to other second nodes.

[0139] In another implementation, if the received hop count related information is equal to the information on an allowed maximum hop count of the relay user equipment contained in the first information, the second node is not able to act as a relay; in another implementation, if the received hop count related information is equal to the information on an allowed maximum hop count of the relay user equipment contained in the first information, the second node is able to act as a relay user equipment.

[0140] In another implementation, the second node may also add one to the received hop count related information as updated hop count related information. When the second node subsequently transmits the first information as the first node, the updated hop count related information is transmitted to other second nodes.

[0141] In another implementation: the second node subtracts one from the received hop count related information as updated hop count related information, and then determines the updated hop count related information. If the updated hop count related information is equal to zero or one or negative one, the second node is not able to act as a relay user equipment; if the updated hop count related information is greater than zero or one or negative one, the second node is able to act as a relay user equipment.

[0142] In another implementation, when the second node subsequently transmits the first information as the first node, the updated hop count related information may also be transmitted to other second nodes.

[0143] In another implementation, the second node adds one to the received hop count related information as updated hop count related information, and then determines the updated hop count related information. If the updated hop count related information is greater than the information on an allowed maximum hop count of the relay user equipment contained in the first information or the information on an allowed maximum hop count of the relay user equipment plus one, the second node is not able to act as a relay user equipment; if the updated hop count related information is less than the information on an allowed maximum hop count of the relay user equipment contained in the first information or the information on an allowed maximum hop count of the relay user equipment plus one, the second node is able to act as a relay user equipment.

[0144] In another implementation, when the second node subsequently transmits the first information as the first node, the updated hop count related information may also be transmitted to other second nodes.

[0145] In another implementation, if the updated hop count related information is equal to the information on an allowed maximum hop count of the relay user equipment contained in the first information or the information on an allowed maximum hop count of the relay user equipment plus one, the second node is not able to act as a relay user equipment. In another implementation, if the updated hop count related information is equal to the information on an allowed maximum hop count of the relay user equipment contained in the first information or the information on an allowed maximum hop count of the relay user equipment plus one, the second node is able to act as a relay user equipment.

[0146] In another implementation, when the second node subsequently transmits the first information as the first node, the updated hop count related information may also be transmitted to other second nodes.

[0147] Through the above method, it is ensured that the relay user equipment will not exceed the allowed maximum value, thereby ensuring that stable communication between the remote user equipment and the base station can be performed through multiple relay user equipment.

[0148] Figure 4B illustrates a method of node interaction / coordination according to one embodiment of the present disclosure. As illustrate in Figure 4B,

[0149] The base station transmits second information used to provide second information related to the multi-hop relay user equipment to the core network.

[0150] The second information includes at least one of the following information:

[0151] - information related to multi-hop relay.

[0152] - an identification / ID list of relay user equipment.

[0153] The information related to multi-hop relay is, in one implementation, used to provide information related to the number of links from the remote user equipment to the last relay user equipment (as in Figure 3A, the links from the remote user equipment to the last relay user equipment includes the link from the remote user equipment to the first relay user equipment, and the link from the first relay user equipment to the last relay user equipment, a total of two links); in another embodiment, it is used to provide information related to the number of relay user equipment from the remote user equipment to the last relay user equipment (as in Figure 3A, the relay user equipment from the remote user equipment to the last relay user equipment only includes the first relay user equipment, a total of one intermediate relay user equipment); in another implementation, it is used to provide information related to the number of relay user equipment from the remote user equipment to the base station (for example, in Figure 3A, the relay user equipment from the remote user equipment to the base station includes the first relay user equipment and the last relay user equipment, a total of two relay user equipment).

[0154] The identification / ID list of relay user equipment contains at least one relay user equipment identification / ID, and for each relay user equipment identification / ID, contains at least one of the following information:

[0155] - AMF user equipment NG Application Protocol (NGAP) identification / ID of the relay user equipment.

[0156] - A radio access network user equipment NGAP identification / ID of the relay user equipment.

[0157] It should be pointed out that each entry / item of relay user equipment identification / ID in the identification / ID list of relay user equipment is listed in a certain order. In one implementation, it is listed in the list in the certain order in which the first entry / item in the list may correspond to the first relay user equipment, the second entry / item corresponds to the second relay user equipment (if the second relay user equipment is supported in the standard), and the last entry / item corresponds to the last relay user equipment. In another embodiment, it is listed in the list in the certain order in which the first entry / item in the list may correspond to the last relay user equipment, the second from last entry / item corresponds to the second relay user equipment (if the second relay user equipment is supported in the standard), and the last entry / item corresponds to the first relay user equipment.

[0158] The second information may be included in an NG application protocol NGAP message, such as an initial user equipment message, a handover required message, a handover request acknowledge message, an uplink non-access stratum transport message, etc., or may also be included in other NGAP messages.

[0159] The core network determines the number of PC5 links based on the information related to multi-hop relay.

[0160] The core network confirms the relay user equipment from the remote user equipment to the base station according to the identification / ID list of relay user equipment.

[0161] After receiving the second information, the core network determines the Quality of Service (QoS) related information of each PC5 link of the multi-hop relay based on the content of the second information, and transmits it to base station through the third information.

[0162] The third information includes a PC5 Quality of Service related information list. Each entry / item of PC5 Quality of Service related information in the PC5 Quality of Service related information list corresponds to the Quality of Service related information of the PC5 link between two relay user equipment or between the remote user equipment and the first relay user equipment.

[0163] It should be pointed out that each entry / item of PC5 Quality of Service related information in the PC5 Quality of Service related information list is listed in a certain order. In one embodiment, as shown in Figure 3A, it is listed in the list in the certain order in which the first entry / item in the list corresponds to the PC5 Quality of Service related information between the remote user equipment and the first relay user equipment, and the second entry / item corresponds to the PC5 Quality of Service related information between the first relay user equipment and the last relay user equipment; in another embodiment, as shown in Figure 3A, it is listed in the list in the certain order in which the first entry / item in the list corresponds to the PC5 quality of service related information between the last relay user equipment and the first relay user equipment, and the second entry / item corresponds to the PC5 quality of service related information between the first relay user equipment and the remote user equipment.

[0164] The third information may be included in an NG application protocol NGAP message, such as an initial context setup request message, a user equipment context modification request message, a handover request message, a path switch request acknowledge message, a downlink non-access stratum transport message, etc., or it can also be included in other NGAP messages.

[0165] The base station stores the PC5 Quality of Service related information list.

[0166] The base station confirms / identifies the Quality of Service related information of each PC5 link from the remote user equipment to the last relay user equipment according to the PC5 Quality of Service related information list.

[0167] Through the above method, it is ensured that the core network can determine the Quality of Service related information of each PC5 link based on the information related to multi-hop relay, thereby further ensuring the Quality of Service of each PC5 link.

[0168] Figure 4C illustrates a method of node interaction / coordination according to one embodiment of the present disclosure. As illustrate in Figure 4C,

[0169] The centralized unit of the base station transmits fourth information related to the multi-hop relay user equipment to the distribution unit of the base station.

[0170] The fourth information includes at least one of the following information:

[0171] - an identification / ID list of relay user equipment.

[0172] - PC5 Quality of Service related information list.

[0173] The identification / ID list of relay user equipment contains at least one relay user equipment identification / ID, and for each relay user equipment identification / ID, contains at least one of the following information:

[0174] - a base station gNB centralized unit user equipment F1 Application Protocol (F1AP) identification / ID of the relay user equipment.

[0175] - a base station gNB distribution unit user equipment F1AP identification / ID of the relay user equipment.

[0176] It should be pointed out that each entry / item of relay user equipment identification / ID in the identification / ID list of relay user equipment is listed in a certain order. In one implementation, it is listed in the list in the certain order in which the first entry / item in the list may correspond to the first relay user equipment, the second entry / item corresponds to the second relay user equipment (if the second relay user equipment is supported in the standard), and the last entry / item corresponds to the last relay user equipment. In another embodiment, it is listed in the list in the certain order in which the first entry / item in the list may correspond to the last relay user equipment, the second from last entry / item corresponds to the second relay user equipment (if the second relay user equipment is supported in the standard), and the last entry / item corresponds to the first relay user equipment.

[0177] Each entry / item of PC5 Quality of Service related information in the PC5 Quality of Service related information list corresponds to the Quality of Service related information of the PC5 link between two relay user equipment or between the remote user equipment and the first relay user equipment.

[0178] It should be pointed out that each entry / item of PC5 Quality of Service related information in the PC5 Quality of Service related information list is listed in a certain order. In one embodiment, as shown in Figure 3A, it is listed in the list in the certain order in which the first entry / item in the list corresponds to the PC5 Quality of Service related information between the remote user equipment and the first relay user equipment, and the second entry / item corresponds to the PC5 Quality of Service related information between the first relay user equipment and the last relay user equipment. In another embodiment, as shown in Figure 3A, it is listed in the list in the certain order in which the first entry / item in the list corresponds to the PC5 quality of service related information between the last relay user equipment and the first relay user equipment, and the second entry / item corresponds to the PC5 quality of service related information between the first relay user equipment and the remote user equipment.

[0179] The fourth information may be included in an F1 application protocol F1AP message, such as a user equipment context setup request message, a user equipment context modification request message, etc., or may also be included in other F1AP messages.

[0180] The distribution unit of the base station confirms the relay user equipment from the remote user equipment to the base station according to the identification / ID list of relay user equipment.

[0181] The distribution unit of base station stores the PC5 Quality of Service related information list.

[0182] The distribution unit of base station confirms the Quality of Service related information of each PC5 link from the remote user equipment to the last relay user equipment according to the PC5 Quality of Service related information list.

[0183] It should be noted that the information contained in the fourth information depends on different implementations.

[0184] In one implementation, the core network determines the Quality of Service related information of each PC5 link in the multi-hop relay: the core network transmits the third information including the PC5 Quality of Service related information list to base station (i.e. base station centralized unit). In this case, in one embodiment, the base station transmits the identification / ID list of relay user equipment and / or the PC5 Quality of Service related information list received from the third information to the distribution unit of base station through the fourth information. In this case, in another implementation, the base station transmits multiple fourth information to the distribution unit of base station; each fourth information includes one relay user equipment identification / ID and / or one entry / item of PC5 quality of service related information; each fourth information is used to setup and / or modify the context of a relay user equipment or remote user equipment.

[0185] In another implementation, the centralized unit of base station determines the Quality of Service related information of each PC5 link in the multi-hop relay: the core network transmits the PC5 Quality of Service related information to the base station (ie, the centralized unit of base station). It should be pointed out that the PC5 quality of service related information corresponds to the quality of service related information on an end-to-end communication link from the last relay user equipment to the remote user equipment. The centralized unit of base station decomposes / splits the PC5 Quality of Service related information, and / or determines the Quality of Service related information of each PC5 link. In this case, in one embodiment, the centralized unit of base station transmits the identification / ID list of relay user equipment and / or the PC5 Quality of Service related information list determined by the centralized unit of base station through the fourth information to the distribution unit of base station. In this case, in another implementation, the base station transmits multiple fourth information to the distribution unit of base station; each fourth information includes one relay user equipment identification / ID and / or one entry / item of PC5 quality of service related information; each fourth information is used to setup and / or modify the context of a relay user equipment or remote user equipment.

[0186] In another implementation, the distribution unit of base station determines the Quality of Service related information of each PC5 link in the multi-hop relay: the core network transmits the PC5 Quality of Service related information to the base station (i.e., the centralized unit of base station). It should be pointed out that the PC5 quality of service related information corresponds to the quality of service related information on an end-to-end communication link from the last relay user equipment to the remote user equipment. The centralized unit of base station transmits the PC5 Quality of Service related information to the distribution unit of the base station. The distribution unit of base station decomposes / splits the PC5 Quality of Service related information, and / or determines the Quality of Service related information of each PC5 link. In this case, in one implementation, the centralized unit of base station transmits the identification / ID list of relay user equipment to the distribution unit of the base station through the fourth information.

[0187] Through the above method, it is ensured that the distribution unit of base station can confirm or determine the Quality of Service related information of each PC5 link, thereby further ensuring the Quality of Service of each PC5 link.

[0188] Figure 4D illustrates a method of node interaction / coordination according to one embodiment of the present disclosure. As illustrate in Figure 4D,

[0189] The centralized unit of base station transmits fifth information related to the Radio Link Control channel (RLC channel) to the distribution unit of the base station.

[0190] The fifth information includes at least one of the following information:

[0191] - PC5 RLC channel first setup list.

[0192] - PC5 RLC channel second setup list.

[0193] - PC5 RLC channel first modification list.

[0194] - PC5 RLC channel second modification list.

[0195] Herein, the PC5 RLC channel first / second setup / modification list contains at least one PC5 RLC channel setup / modification entry / item, for each PC5 RLC channel setup / modification entry / item, at least one of the following information:

[0196] - relay user equipment related identification / ID.

[0197] - a remote user equipment related identification / ID list.

[0198] The relay user equipment related identification / ID includes at least one of the following information:

[0199] - a local identification / ID (Local ID) of a relay user equipment.

[0200] - a destination identification / ID (Destination ID) of a relay user equipment.

[0201] - a base station gNB centralized unit user equipment F1AP identification / ID of a relay user equipment.

[0202] - a base station gNB distribution unit user equipment F1AP identification / ID of a relay user equipment.

[0203] The remote user equipment related identification / ID list includes at least one remote user equipment local identification / ID.

[0204] The fifth information may be included in an F1 application protocol F1AP message, such as a user equipment context setup request message, a user equipment context modification request message, etc., or may also be included in other F1AP messages.

[0205] The distribution unit of base station identifies the relay user equipment corresponding to the PC5 RLC channel setup / modification entry / item according to the relay user equipment related identification / ID.

[0206] The distribution unit of base station identifies at least one remote user equipment corresponding to the PC5 RLC channel according to the remote user equipment related identification / ID list.

[0207] It should be pointed out that the information contained in the fifth information depends on different situation / conditions.

[0208] Taking the scenario in Figure 3B as an example:

[0209] If the fifth information is used for modification or setup of the last relay user equipment context, the fifth information includes the PC5 RLC channel second setup entry / item and / or the PC5 RLC channel second modification entry / item. The PC5 RLC channel corresponds to the PC5 RLC channel between the last relay user equipment and the second relay user equipment. In this case, the second PC5 RLC channel setup entry / item and / or the second PC5 RLC channel modification entry / item include the second relay user equipment related identification / ID.

[0210] If the fifth information is used for modification or setup of a second relay user equipment context, the fifth information includes the PC5 RLC channel first setup entry / item and / or the PC5 RLC channel first modification entry / item and / or the PC5 RLC channel second setup entry / item and / or the PC5 RLC channel second modification entry / item. The PC5 RLC channel first setup / modification entry / item corresponds to the PC5 RLC channel between the second relay user equipment and the last relay user equipment. The PC5 RLC channel second setup / modification entry / item corresponds to the PC5 RLC channel between the second relay user equipment and the first relay user equipment. In this case, the PC5 RLC channel second setup entry / item and / or the PC5 RLC channel second modification entry / item include the first relay user equipment related identification / ID.

[0211] If the fifth information is used for modification or setup of the first relay user equipment context, the fifth information includes the PC5 RLC channel first setup entry / item and / or the PC5 RLC channel first modification entry / item and / or the PC5 RLC channel second setup entry / item and / or the PC5 RLC channel second modification entry / item. The PC5 RLC channel first setup / modification entry / item corresponds to the PC5 RLC channel between the first relay user equipment and the second relay user equipment. The PC5 RLC channel second setup / modification entry / item corresponds to the PC5 RLC channel between the first relay user equipment and the remote user equipment.

[0212] If the fifth information is used for modification or setup of a remote relay user equipment context, the fifth information includes the PC5 RLC channel first setup entry / item and / or the PC5 RLC channel first modification entry / item. The PC5 RLC channel first setup / modification entry / item corresponds to the PC5 RLC channel between the remote user equipment and the first relay user equipment.

[0213] It should be pointed out that in one implementation, if the fifth information is used to modify or establish the context of the relay user equipment of this hop, if the entry / item contains the relay user equipment related identification / ID of the previous hop, then the PC5 RLC channel corresponding to the corresponding entry / item or list is the PC5 RLC channel between the relay user equipment of this hop and the relay user equipment of the previous hop. If the entry / item does not contain a relay user equipment related identification / ID, the PC5 RLC channel corresponding to the corresponding entry / item or list is the PC5 RLC channel between the relay user equipment of this hop and the relay user equipment of the next hop.

[0214] Taking the scenario of Figure 3B as an example, if the fifth information is used to modify or establish the context of the second relay user equipment, if the entry / item contains the relay user equipment related identification / ID (i.e., the first relay user equipment related identification / ID), then the PC5 RLC channel corresponding to the corresponding entry / item or list is the PC5 RLC channel between the second relay user equipment and the first relay user equipment. If the entry / item does not contain the relay user equipment related identification / ID, the PC5 RLC channel corresponding to the corresponding entry / item or list is the PC5 RLC channel between the second relay user equipment and the last relay user equipment.

[0215] Through the above method, it is ensured that the distribution unit of base station can perform correct PC5 RLC channel related configuration for the relay user equipment of each hop, thereby further ensuring that the remote user equipment and the base station can communicate through multi-hop relay.

[0216] Figure 4E illustrates a method of node interaction / coordination according to one embodiment of the present disclosure. As illustrate in Figure 4E,

[0217] The base station or centralized unit of base station transmits sixth information related to the remote user equipment to the first node.

[0218] The sixth information includes at least one of the following information:

[0219] - a remote user equipment related identification / ID.

[0220] - a remote user equipment radio bearer identification / ID.

[0221] - a relay user equipment related identification / ID, which is used to identify a previous hop relay user equipment.

[0222] - a first egress radio link control (RLC) channel identification / ID, which is used to identify the egress RLC channel between the first node and the previous hop relay user equipment or the remote user equipment.

[0223] - a second egress RLC channel identification / ID, which is used to identify the egress RLC channel between the first node and the next hop relay user equipment or network.

[0224] The remote user equipment related identification / ID or the relay user equipment related identification / ID includes at least one of the following information:

[0225] - a local identification / ID (Local ID) of user equipment.

[0226] - a destination identification / ID (Destination ID) of user equipment.

[0227] It should be noted that the first node can be a remote user equipment, a first relay user equipment, a second relay user equipment, a last relay user equipment, or other relay user equipment.

[0228] The sixth information can be included in an RRC message, such as an RRC reconfiguration message, etc., or can be included in other RRC messages.

[0229] The first node confirms or identifies the remote user equipment according to the remote user equipment related identification / ID.

[0230] The first node confirms or identifies the radio bearer of the remote user equipment according to the remote user equipment radio bearer identification / ID.

[0231] The first node confirms the previous hop relay user equipment according to the relay user equipment related identification / ID.

[0232] The first node confirms the egress RLC channel of downlink transmission (i.e., transmission from this hop relay user equipment to the previous hop relay user equipment or remote user equipment) according to the first egress RLC channel identification / ID.

[0233] The first node confirms the egress RLC channel of the uplink transmission (i.e., the transmission from the remote user equipment or the this hop relay user equipment to the next hop relay user equipment or the network) according to the second egress RLC channel identification / ID.

[0234] It should be pointed out that if the first node is a remote user equipment, the sixth information (also called the sixteenth information) includes the second egress RLC channel identification / ID (also called the fifth egress RLC channel identification / ID). The second egress RLC channel identification / ID (also called a fifth egress RLC channel identification / ID) is a PC5 RLC channel identification / ID. The second egress RLC channel(also called a fifth egress RLC channel) is an RLC channel between the remote user equipment and the first relay user equipment.

[0235] If the first node is the first relay user equipment, the sixth information includes the first egress RLC channel identification / ID and the second egress RLC channel identification / ID. The first egress RLC channel identification / ID and the second egress RLC channel identification / ID are PC5 RLC channel identification / IDs. The first egress RLC channel is an RLC channel between the first relay user equipment and the remote user equipment. The second egress RLC channel is an RLC channel between the first relay user equipment and the second relay user equipment.

[0236] If the first node is the second relay user equipment, the sixth information includes the first egress RLC channel identification / ID and the second egress RLC channel identification / ID. The first egress RLC channel identification / ID and the second egress RLC channel identification / ID are PC5 RLC channel identification / IDs. The first egress RLC channel is an RLC channel between the second relay user equipment and the first relay user equipment. The second egress RLC channel is an RLC channel between a second relay user equipment and a last relay user equipment.

[0237] If the first node is the last relay user equipment, the sixth information (also called eleventh information) includes the first egress RLC channel identification / ID (also called the third egress RLC channel identification / ID) and the second egress RLC channel identification / ID (also called the fourth egress RLC channel identification / ID). The first egress RLC channel identification / ID (also called third egress RLC channel identification / ID) is a PC5 RLC channel identification / ID. The second egress RLC channel identification / ID (also called a fourth egress RLC channel identification / ID) is a Uu RLC channel identification / ID. The first egress RLC channel (also called a third egress RLC channel) is the RLC channel between the last relay user equipment and the second relay user equipment. The second egress RLC channel (also called fourth egress RLC channel) is the RLC channel between the last relay user equipment and the base station or distribution unit of base station or network.

[0238] It should be pointed out that, in one implementation, when a relay user equipment in a multi-hop relay receives the sixth information, when the relay user equipment receives a downlink data, the relay user equipment confirms the remote user equipment to which the downlink data is to be sent by the user equipment related identification / ID contained in the Sidelink Relay Adaptation Protocol (SRAP) header corresponding to the downlink data. The relay user equipment confirms the radio bearer of the remote user equipment to which downlink data is to be sent by the bearer identification / ID contained in the SRAP header. The relay user equipment determines the egress link (i.e., the previous hop relay user equipment to which downlink data needs to be sent) by the relay user equipment related identification / ID in the sixth information associated with the remote user equipment related identification / ID and / or the remote user equipment radio bearer identification / ID contained in the sixth information. The relay user equipment determines the egress RLC channel (i.e., the RLC channel between the remote user equipment or the previous hop relay user equipment to which downlink data needs to be sent) by the first egress RLC channel identification / ID in the sixth information associated with the remote user equipment related identification / ID and / or the remote user equipment radio bearer identification / ID and / or the relay user equipment related identification / ID contained in the sixth information.

[0239] It should be pointed out that, in one implementation, when a relay user equipment in the multi-hop relay receives the sixth information, when the relay user equipment receives an uplink data, the relay user equipment confirms which remote user equipment the uplink data comes from, by the user equipment related identification / ID contained in the Sidelink Relay Adaptation Protocol (SRAP) header corresponding to the uplink data. The relay user equipment confirms which radio bearer the uplink data comes from, by the bearer identification / ID contained in the SRAP header. The relay user equipment determines the egress RLC channel (i.e., the RLC channel between the network or the next hop relay user equipment to which uplink data needs to be sent) by the second egress RLC channel identification / ID in the sixth information associated with the remote user equipment related identification / ID and / or the remote user equipment radio bearer identification / ID contained in the sixth information.

[0240] It should be noted that in one embodiment, the first egress RLC channel identification / ID contained in the sixth information transmitted to the relay user equipment of this hop may be the same as the second egress RLC channel identification / ID contained in the sixth information transmitted to the relay user equipment of the previous hop.

[0241] Through the above method, it is ensured that the relay user equipment of each hop in the multi-hop relay can transmit the received data to the correct egress link or egress RLC channel, thereby further ensuring that the communication or data transmission between the remote user equipment and the base station can be carried out through the multi-hop relay.

[0242] Figure 4F illustrates a method of node interaction / coordination according to one embodiment of the present disclosure. As illustrate in Figure 4F,

[0243] The first node transmits seventeenth information for notification to the second node.

[0244] The seventeenth information includes at least one of the following information:

[0245] - information related to relay user equipment re-establishment.

[0246] - information related to relay user equipment relay reselection.

[0247] - information related to a next hop or next-multi-hop relay user equipment.

[0248] Herein the information related to the next hop or next-multi-hop relay user equipment includes at least one of the following information:

[0249] - information related to next hop or next-multi-hop relay user equipment air interface (Uu) radio link failures.

[0250] - information related to next hop or next-multi-hop relay user equipment handover.

[0251] - information related to next hop or next-multi-hop relay user equipment cell reselection.

[0252] - information related to next hop or next-multi-hop relay user equipment radio resource control failures.

[0253] - information related to a next hop or next-multi-hop relay user equipment PC5 radio link failures.

[0254] It should be pointed out that if the first node is the last relay user equipment, the second node is the second relay user equipment (as shown in Figure 3B) or the first relay user equipment (as shown in Figure 3A) or the remote user equipment; if the first node is the second relay user equipment, the second node is the first relay user equipment or the remote user equipment; if the first node is the first relay user equipment, the second node is the remote user equipment.

[0255] If the first node is a relay user equipment, the seventeenth information may be included in a PC5 radio resource control (PC5-RRC) message, such as a sidelink notification message, etc., or may also be included in other PC5-RRC messages.

[0256] In one implementation: the first node transmits seventeenth information including the information related to relay user equipment re-establishment or the information related to relay reselection of the relay user equipment to the second node. After receiving the seventeenth information, the second node confirms that radio resource control re-establishment has occurred in the first node. If the second node is in a radio resource control connected state, the second node initiates a radio resource control re-establishment process. If the second node is in a radio resource control inactive state or idle state, and if the second node decides to release the PC5 RRC connection with the first node, the second node triggers a relay reselection or cell reselection process. If the second node is in a radio resource control inactive state or idle state, and if the second node maintains a PC5 RRC connection with the first node, the second node considers that a cell reselection has been occurred.

[0257] In another implementation: taking Figure 3B as an example, the last user equipment initiates the transmission of seventeenth information, and the seventeenth information includes information related to the (last) relay user equipment re-establishment. After the second relay user equipment receives the seventeenth information from the last user equipment, if the second relay user equipment is in a radio resource control connection state, the second relay user equipment initiates a radio resource control re-establishment process. Afterwards, the second relay user equipment initiates the transmission of seventeenth information, and the seventeenth information contains information related to the (second) relay user equipment re-establishment. When the first relay user equipment receives the seventeenth information from the second relay user equipment, if the first relay user equipment is in the radio resource control inactive state or idle state, and if the first relay user equipment decides to release the PC5 RRC connection with the second relay user equipment, the first relay user equipment initiates a relay reselection or cell reselection process. Afterwards (in one embodiment, when the first relay user equipment completes the relay reselection process), the first relay user equipment initiates the transmission of seventeenth information, where the seventeenth information includes information related to (first) relay user equipment relay reselection. After the remote user equipment receives the seventeenth information from the first relay user equipment, if the remote user equipment maintains the PC5 RRC connection with the first relay user equipment, the first relay user equipment considers that cell reselection has been occurred.

[0258] In another implementation: the first node transmits seventeenth information including the information related to the next hop or next-multi-hop relay user equipment to the second node. After receiving the seventeenth information, the second node confirms that the Uu radio link failure / handover / cell reselection / radio resource control failure / PC5 radio link failure has occurred in the next hop or next-multi-hop relay user equipment of the first node (taking Figure 3B as an example, if the first node is the first relay user equipment, the next hop of the first node is the second relay user equipment, and the next two hops of the second node are the last relay user equipment). If the second node is in a radio resource control connected state, the second node initiates a radio resource control re-establishment process. If the second node is in a radio resource control inactive or idle state, and if the second node maintains a PC5 RRC connection with the first node, and if a handover or cell reselection has occurred in a next hop or next-multi-hop relay user equipment of the first node, the second node considers that a cell reselection has been occurred. If the second node is in a radio resource control inactive state or idle state, and if the second node maintains a PC5 RRC connection with the first node, and if a Uu radio link failure or a radio resource control failure or a PC5 radio link failure has occurred a next hop or next-multi-hop relay user equipment of the first node, the second node may subsequently initiate the transmission of seventeenth information as the first node, wherein the seventeenth information includes the information related to the next hop or next-multi-hop relay user equipment.

[0259] In another implementation, taking Figure 3A as an example, the last relay user equipment initiates a transmission, and the transmission includes information related to that a Uu radio link failure or a radio resource control failure or PC5 radio link failure has occurred in the (last) relay user equipment. After receiving the related information from the last relay user equipment, the first relay user equipment may initiate the transmission of seventeenth information, where the seventeenth information includes information related to the next hop relay user equipment (i.e., the last relay user equipment). After receiving the seventeenth information from the first relay user equipment, the remote user equipment confirms that a Uu radio link failure, a radio resource control failure or a PC5 radio link failure has occurred in the next hop or next multi-hop relay user equipment.

[0260] Through the above method, it is ensured that the relay user equipment of this hop can initiate a transmission for notification to the relay user equipment of the previous hop or the remote user equipment, thereby ensuring that the remote user equipment can obtain the connection situation / conditions between the base station and multiple relay user equipment, which are between the remote user equipment and the base station, thereby ensuring the smooth progress of subsequent communications.

[0261] Figure 4G illustrates a method of node interaction / coordination according to one embodiment of the present disclosure. As illustrate in Figure 4G,

[0262] A second node transmits an eighteenth information to a first node for requesting a system information block or providing paging related information.

[0263] The eighteenth information includes information related to previous hop or previous-multi-hop relay user equipment or remote user equipment.

[0264] Herein, the information related to the previous hop or previous-multi-hop relay user equipment or remote user equipment includes at least one of the following information:

[0265] - system information block related information requested by the previous hop or the previous-multi-hop relay user equipment or the remote user equipment.

[0266] - information related to previous hop or previous-multi-hop relay user equipment or remote user equipment paging.

[0267] Herein, the information related to paging of the previous hop or previous-multi-hop relay user equipment or remote user equipment includes at least one of the following information:

[0268] - a paging identification / ID of previous or previous-multi-hop relay user equipment or remote user equipment.

[0269] - a paging cycle / period of previous-multi-hop relay user equipment or remote user equipment.

[0270] It should be pointed out that if the first node is the last relay user equipment, the second node is the second relay user equipment (as shown in Figure 3B) or the first relay user equipment (as shown in Figure 3A); if the first node is the second relay user equipment, the second node is the first relay user equipment.

[0271] If the first node is a relay user equipment, the eighteenth information may be included in a PC5 Radio Resource Control (PC5-RRC) message, such as a sidelink user equipment information message, a sidelink relay user equipment information message, etc., and may also be included in other PC5-RRC messages.

[0272] In one implementation: the second node transmits eighteenth information to the first node. After receiving the eighteenth information, when the first node subsequently serves as the second node, the first node transmits the content contained in the eighteenth information to the subsequent first node.

[0273] In another implementation: taking Figure 3A as an example, the remote user equipment transmits the requested system information block related information and / or paging related information to the first relay user equipment. After receiving the information, the first relay user equipment includes the information in the eighteenth information and transmits it to the last relay user equipment.

[0274] The first node may receive the eighteenth information from multiple second nodes.

[0275] In one implementation, the first node may combine eighteenth information received from multiple second nodes. When the first node subsequently serves as the second node, it transmits the combined eighteenth information to the subsequent first node.

[0276] In another implementation, when the first node subsequently serves as the second node, it directly transmits the eighteenth information received from the original second node to the subsequent first node.

[0277] Through the above method, it is ensured that the intermediate relay user equipment can finally send the system information block request information or paging related information received from the remote user equipment or the previous hop or previous-multi-hop relay user equipment in the inactive state or idle state to the last relay user equipment, thereby ensuring that subsequent system information or system information block containing the requested system information block or paging message can be transmitted to the remote user equipment or previous hop or previous-multi-hop relay user equipment in the inactive state or idle state.

[0278] Figure 4HA and 4HB illustrate a method of node interaction / coordination according to one embodiment of the present disclosure. As illustrate in Figure 4HA and 4HB,

[0279] Taking the multi-hop relay scenario in Figure 3B as an example,

[0280] Step 0, perform a relay discovery process and a PC5 connection process between multiple relay user equipment, and between a relay user equipment and a remote user equipment. Optionally, during or after step 0, the relay user equipment and / or the remote user equipment may trigger relay selection or reselection. Optionally, the relay user equipment and / or the remote user equipment may receive the first information for relay selection or reselection from other relay user equipment. Optionally, the relay user equipment and / or the remote user equipment may perform relay selection or reselection according to the first information. Optionally, the relay user equipment (except the last relay user equipment) and / or the remote user equipment may receive the seventeenth information for notification from the next hop relay user equipment. Optionally, the relay user equipment may initiate the transmission of the seventeenth information. Optionally, the relay user equipment may receive the eighteenth information from the previous hop relay user equipment for requesting a system information block or providing paging related information. Optionally, the relay user equipment (except the last relay user equipment) may send the eighteenth information to the next hop relay user equipment. Optionally, the relay user equipment (except the last relay user equipment) and / or the remote user equipment may receive system information or system information block containing the requested system information block or paging message sent from the next hop relay user equipment.

[0281] Step 1: The remote user equipment transmits an RRC setup request message to the first relay user equipment.

[0282] Step 2: The first relay user equipment retains the RRC setup request message from the remote user equipment and transmits a side link user equipment information message to the base station.

[0283] Step 3: The centralized unit of base station transmits a user equipment context modification request message to the distribution unit of the base station, which contains the fourth information and / or the fifth information for the last relay user equipment context modification.

[0284] Step 4: The base station transmits an RRC reconfiguration message to the last relay user equipment, which contains the sixth information transmitted to the last relay user equipment.

[0285] Step 5: The centralized unit of base station transmits a user equipment context modification request message to the distribution unit of base station, which contains the fourth information and / or the fifth information for context modification of the second relay user equipment.

[0286] Step 6: The base station transmits an RRC reconfiguration message to the second relay user equipment, which contains the sixth information transmitted to the second relay user equipment.

[0287] Step 7: The centralized unit of base station transmits a user equipment context modification request message to the distribution unit of base station, which contains the fourth information and / or the fifth information for first relay user equipment context modification.

[0288] Step 8: The base station transmits an RRC reconfiguration message to the first relay user equipment, which contains the sixth information transmitted to the first relay user equipment.

[0289] Step 9: The first relay user equipment transmits an RRC setup request message from the remote user equipment to the base station.

[0290] Step 10: The base station transmits an RRC setup message to the remote user equipment.

[0291] Step 11: The remote user equipment transmits an RRC setup complete message to the base station.

[0292] Step 12, The base station transmits an initial user equipment message to the core network, optionally containing the second information.

[0293] Step 13: The core network transmits an initial context setup request message to the base station, optionally including the third information.

[0294] Step 14: The centralized unit of base station transmits a user equipment context modification request message to the distribution unit of the base station, which contains the fourth information and / or the fifth information for remote user equipment context setup.

[0295] Step 15: The base station transmits an RRC reconfiguration message to the remote user equipment, which contains the sixth information transmitted to the remote user equipment.

[0296] Figure 5 is a block diagram of a node device according to an embodiment of the present disclosure.

[0297] A network node in the network can be used to implement the first node to the eleventh node in the present invention. Referring to Figure 4, the node device according to the present invention includes a transceiver 510, a controller 520 and a memory 530. The transceiver 510, the controller 520 and the memory 530 are configured to perform the operations of the methods and / or embodiments of the present invention. Although the transceiver 510, the controller 520 and the memory 530 are shown as separate entities, they may be implemented as a single entity, such as a single chip. The transceiver 510, the controller 520 and the memory 530 may be electrically connected or coupled to each other. The transceiver 510 may transmit and receive signals to and from other network nodes. The controller 520 may include one or more processing units, and may control the network device or user equipment to perform the operations and / or functions according to one of the above embodiments. The memory 530 may store instructions for implementing the operations and / or functions of one of the above embodiments described.

[0298] Those skilled in the art will understand that the illustrative embodiments described above are described herein and are not intended to be limiting. It should be understood that any two or more of the embodiments disclosed herein can be combined in any combination. In addition, other embodiments can be utilized and other changes can be made without departing from the spirit and scope of the subject matter presented herein. It will be readily understood that aspects of the present invention of the present disclosure, as generally described herein and shown in the accompanying drawings, can be arranged, substituted, combined, separated and designed in various different configurations, all of which are contemplated herein.

[0299] Those skilled in the art will understand that the various illustrative logical blocks, modules, circuits, and steps described in the present application can be implemented as hardware, software, or a combination of both. In order to clearly illustrate this interchangeability between hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above in the form of their function set. Whether such a function set is implemented as hardware or software depends on the specific application and the design constraints imposed on the total / overall system. Skilled people can implement the described function set in different ways for each specific application, but such design decisions should not be interpreted as causing a departure from the scope of the present application.

[0300] The various illustrative logic blocks, modules, and circuits described in the present application can be implemented in a general-purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic devices, discrete gate or transistor logic, discrete hardware component, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors cooperating with a DSP core, or any other such configuration.

[0301] The steps of the method or technique described in the present application can be embodied directly in hardware, in a software module performed by a processor, or in a combination of both. Software modules may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, register, hard disk, removable disk, or any other form of storage media known in the art. An exemplary storage medium is coupled to a processor to enable the processor to read and write information from / to the storage medium. In the alternative, the storage medium may be integrated into the processor. The processor and storage medium may reside in an ASIC. The ASIC may reside in the UE. In the alternative, the processor and the storage medium may reside in the UE as discrete components.

[0302] In one or more exemplary designs, the described functions can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, each function can be stored on or transferred by a computer-readable medium as one or more instructions or codes. Computer-readable media include both computer storage media and communication media, which includes any media that facilitates the transfer of computer programs from one place to another. The storage medium may be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0303] What has been described above is only an exemplary embodiment of the present disclosure, and is not used to limit the protection scope of the present disclosure, which is determined by the appended claims.

Claims

1.A method performed by a remote user equipment (UE) in a wireless communication system, the method comprising:receiving, from a first relay UE, a PC5 radio resource control (RRC) message indicating a PC5 radio link failure; andtriggering a relay reselection based on the PC5 radio link failure,wherein the PC5 RRC message includes information related to the relay reselection of the remote UE.2.The method of claim 1, further comprising:receiving, from the first relay UE, information on a Uu radio link failure; andconfirming the Uu radio link failure based on the information on the Uu radio link failure,wherein the information on the Uu radio link failure from the first relay UE is based on a notification message related to the Uu radio link failure from a last relay UE.3.The method of claim 1, further comprising:transmitting, to the first relay UE, information for system information acquisition in multi-hop,wherein the information for system information acquisition in multi-hop includes system information block related information requested by the remote UE.4.The method of claim 1, further comprising:transmitting a message containing paging information,wherein the paging information includes a paging identification (ID) and paging cycle of the remote UE.5.A method performed by a first relay user equipment (UE) in a wireless communication system, the method comprising:identifying a PC5 radio link failure; andtransmitting, to a remote UE, a PC5 radio resource control (RRC) message indicating the PC5 radio link failure;wherein the PC5 RRC message includes information related to the relay reselection of the remote UE, andwherein a relay reselection is triggered based on the PC5 radio link failure.6.The method of claim 5, further comprising:receiving, from a last relay UE, a notification message related to the Uu radio link failure; andtransmitting, to the remote UE, information on the Uu radio link failure.7.The method of claim 5, further comprising:receiving, from the remote UE, first information for system information acquisition in multi-hop, wherein the first information for system information acquisition in multi-hop includes system information block related information requested by the remote UE; andtransmitting, to a last relay UE, second information for system information acquisition in multi-hop, wherein the second information for system information acquisition in multi-hop includes system information block related information requested by the first relay UE.8.The method of claim 5, further comprising:receiving, from the remote UE, a message containing first paging information, wherein the first paging information includes a paging identification (ID) and paging cycle of the remote UE; andtransmitting, to a last relay UE, a message containing second paging information, wherein the second paging information includes a paging identification (ID) and paging cycle of the first relay UE.9.A remote user equipment (UE) in a wireless communication system, the remote UE comprising:at least one transceiver; andat least one processor coupled with the at least one transceiver and configured to:receive, from a first relay UE, a PC5 radio resource control (RRC) message indicating a PC5 radio link failure, andtrigger a relay reselection based on the PC5 radio link failure,wherein the PC5 RRC message includes information related to the relay reselection of the remote UE.10.The remote UE of claim 9,wherein the at least one processor is further configured to:receive, from the first relay UE, information on a Uu radio link failure; andconfirm the Uu radio link failure based on the information on the Uu radio link failure,wherein the information on the Uu radio link failure from the first relay UE is based on a notification message related to the Uu radio link failure from a last relay UE.11.The remote UE of claim 9,wherein the at least one processor is further configured to transmit, to the first relay UE, information for system information acquisition in multi-hop, andwherein the information for system information acquisition in multi-hop includes system information block related information requested by the remote UE.12.The remote UE of claim 9,wherein the at least one processor is further configured to transmit a message containing paging information, andwherein the paging information includes a paging identification (ID) and paging cycle of the remote UE.13.A first relay user equipment (UE) in a wireless communication system, the first relay UE comprising:at least one transceiver; andat least one processor coupled with the at least one transceiver and configured to:identify a PC5 radio link failure; andtransmit, to a remote UE, a PC5 radio resource control (RRC) message indicating the PC5 radio link failure;wherein the PC5 RRC message includes information related to the relay reselection of the remote UE, andwherein a relay reselection is triggered based on the PC5 radio link failure.14.The first relay UE of claim 13,wherein the at least one processor is further configured to:receive, from a last relay UE, a notification message related to the Uu radio link failure; andtransmit, to the remote UE, information on the Uu radio link failure.15.The first relay UE of claim 13,wherein the at least one processor is further configured to:receive, from the remote UE, first information for system information acquisition in multi-hop, wherein the first information for system information acquisition in multi-hop includes system information block related information requested by the remote UE;transmit, to a last relay UE, second information for system information acquisition in multi-hop, wherein the second information for system information acquisition in multi-hop includes system information block related information requested by the first relay UE;receive, from the remote UE, a message containing first paging information, wherein the first paging information includes a paging identification (ID) and paging cycle of the remote UE; andtransmit, to a last relay UE, a message containing second paging information, wherein the second paging information includes a paging identification (ID) and paging cycle of the first relay UE.

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