Communication method and apparatus, communication device, chip, storage medium, program and program product

Abstract

Provided in the embodiments of the present application are communication methods and apparatus, a terminal device and a network device. A method comprises: a first device receives a first discovery message sent by one or more second devices, the first discovery message comprising related information of each of one or more first paths supported by the second device, the first path being a transmission path between the second device and a network device, and the first path comprising a single-hop link or a multi-hop link; and, on the basis of the first discovery message, the first device selects a target relay device and / or a target path, the target relay device being one of the one or more second devices, and the target path being one of the first path supported by the one or more second devices.

Description

Communication method and apparatus, communication device, chip, storage medium, program, program product TECHNICAL FIELD

[0001] Embodiments of the present application relate to the field of mobile communication technology, in particular to a communication method and apparatus, a communication device, a chip, a computer storage medium, a computer program, and a computer program product. BACKGROUND

[0002] With the development of technology, a user equipment-to-network relay (UE-NW relay) technology is introduced into a communication system to expand network coverage.

[0003] The current UE-NW relay technology only supports a single-hop scenario, that is, one relay device is set between a remote UE and a network. The future UE-NW relay technology can be extended to a multi-hop scenario, that is, multiple relay devices are set between the remote UE and the network. In the multi-hop scenario, how to select a relay device and how to select a path are technical problems to be solved.

[0004] SUMMARY

[0005] Embodiments of the present application provide a communication method and apparatus, a communication device, a chip, a computer storage medium, a computer program, and a computer program product.

[0006] In a first aspect, a communication method is provided, and the method comprises:

[0007] A first device receives a first discovery message sent by one or more second devices, the first discovery message comprising relevant information of each first path supported by the second device; the first path is a transmission path between the second device and a network device, and the first path comprises a single-hop link or a multi-hop link.

[0008] The first device selects a target relay device and / or a target path based on the first discovery message, the target relay device being one or more of the one or more second devices, and the target path being one or more of the first paths supported by the one or more second devices.

[0009] In a second aspect, a communication method is provided, and the method comprises:

[0010] The second device sends a first discovery message, the first discovery message including related information of each of one or more first paths supported by the second device; the first path being a transmission path between the second device and a network device, the first path including a single-hop link or a multi-hop link; the first discovery message being used for selecting a target relay device and / or a target path.

[0011] In a third aspect, a communication method is provided, the method comprising:

[0012] The third device sends a second discovery message;

[0013] The second discovery message including related information of each of one or more second paths supported by the third device; the second path being a transmission path between the third device and a network device, the second path including a single-hop or a multi-hop link; the first discovery message being related to the second discovery message, the first discovery message being used for selecting a target relay device and / or a target path.

[0014] In a fourth aspect, a communication apparatus is provided, applied to a first device, the apparatus comprising:

[0015] A first receiving unit, configured to receive a first discovery message sent by one or more second devices, the first discovery message including related information of each of one or more first paths supported by the second device; the first path being a transmission path between the second device and a network device, the first path including a single-hop link or a multi-hop link;

[0016] A first selecting unit, configured to select a target relay device and / or a target path based on the first discovery message, the target relay device being one or more of the one or more second devices, the target path being one or more of the first paths supported by the one or more second devices.

[0017] In a fifth aspect, a communication apparatus is provided, applied to a second device, the apparatus comprising:

[0018] A second sending unit, configured to send a first discovery message, the first discovery message including related information of each of one or more first paths supported by the second device; the first path being a transmission path between the second device and a network device, the first path including a single-hop link or a multi-hop link; the first discovery message being used for selecting a target relay device and / or a target path.

[0019] In a sixth aspect, a communication apparatus is provided, applied to a third device, the apparatus comprising:

[0020] A third sending unit, configured to send a second discovery message;

[0021] The second discovery message includes relevant information of each of one or more second paths supported by the third device, and the second path is a transmission path between the third device and a network device, and the second path includes a single-hop or multi-hop link. The first discovery message is related to the second discovery message, and the first discovery message is used to select a target relay device and / or a target path.

[0022] In a seventh aspect, a network device is provided, which includes a processor and a memory. The memory is configured to store a computer program, and the processor is configured to invoke and run the computer program stored in the memory to perform the communication method.

[0023] The chip is configured to implement the communication method.

[0024] Specifically, the chip includes a processor configured to invoke and run a computer program from a memory, so that a device installed with the chip performs the communication method.

[0025] The computer readable storage medium is configured to store a computer program, and the computer program causes a computer to perform the communication method.

[0026] The computer program product includes computer program instructions, and the computer program instructions cause a computer to perform the communication method.

[0027] The computer program causes a computer to perform the communication method when the computer program runs on the computer.

[0028] A communication method is provided. A first device can receive a first discovery message sent by one or more second devices, and the first discovery message carries relevant information of one or more first paths supported by the second devices. In this way, the first device can select a target relay device and a target path according to the one or more first paths supported by the one or more second devices. It can be seen that the first discovery message can carry relevant information of a link that cannot be directly observed by the first device, so that the first device can select a more suitable target relay device and target path based on the first discovery message. BRIEF DESCRIPTION OF DRAWINGS

[0029] The accompanying drawings, which are included to provide a further understanding of the application and constitute a part of this application, illustrate embodiments of the application and serve to explain the principle of the application, and do not constitute improper limitations on the application. In the drawings:

[0030] FIG. 1 is a schematic diagram of an application scenario of an embodiment of the present application.

[0031] FIG. 2 is a schematic diagram of a mode A discovery procedure according to an embodiment of the present application;

[0032] FIG. 3 is a schematic diagram of a mode B discovery procedure according to an embodiment of the present application;

[0033] FIG. 4A is a schematic diagram of a no MP-like topology according to an embodiment of the present application;

[0034] FIG. 4B is a schematic diagram of a no MP-like topology according to an embodiment of the present application;

[0035] FIG. 4C is a schematic diagram of a MP-like topology according to an embodiment of the present application;

[0036] FIG. 5 is a schematic diagram of a communication method according to an embodiment of the present application;

[0037] FIG. 6 is a schematic diagram of a topology according to an embodiment of the present application;

[0038] FIG. 7 is a schematic diagram of a communication method according to an embodiment of the present application;

[0039] FIG. 8A and FIG. 8B are schematic diagrams of information interaction according to an embodiment of the present application;

[0040] FIG. 9 is a schematic diagram of a topology according to an embodiment of the present application;

[0041] FIG. 10A and FIG. 10B are schematic diagrams of a communication method according to an embodiment of the present application;

[0042] FIG. 11 is a schematic diagram of a communication method according to an embodiment of the present application;

[0043] FIG. 12 is a schematic diagram of a communication method according to an embodiment of the present application;

[0044] FIG. 13 is a schematic diagram of a communication method according to an embodiment of the present application;

[0045] FIG. 14 is a schematic diagram of a communication method according to an embodiment of the present application;

[0046] FIG. 15 is a schematic diagram of a communication apparatus according to an embodiment of the present application;

[0047] FIG. 16 is a schematic diagram of a communication apparatus according to an embodiment of the present application;

[0048] FIG. 17 is a schematic diagram of a communication apparatus according to an embodiment of the present application;

[0049] FIG. 18 is a schematic structural diagram of a communication device according to an embodiment of the present application;

[0050] FIG. 19 is a schematic structural diagram of a chip according to an embodiment of the present application;

[0051] FIG. 20 is a schematic block diagram of a communication system according to an embodiment of the present application. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0053] It should be noted that the terms "system" and "network" are often used interchangeably in this document.

[0054] It should be understood that the term "and / or" in this document is only used to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent the existence of A alone, the existence of A and B together, and the existence of B alone. In addition, the character " / " in this document generally represents an "or" relationship between the front and rear associated objects.

[0055] It should also be understood that the "indication" mentioned in the embodiments of the present application can be direct indication or indirect indication, or can represent an associated relationship. For example, A indicates B, which can mean that B can be obtained through A; or A indirectly indicates B, for example, A indicates C, and B can be obtained through C; or A and B have an associated relationship. It should also be understood that the "corresponding" mentioned in the embodiments of the present application can represent a direct correspondence or an indirect correspondence between the two, or can represent an associated relationship between the two, or can mean an indication and being indicated, a configuration and being configured, etc. It should also be understood that the "predefined" or "predefined rule" mentioned in the embodiments of the present application can be realized by pre-saving the corresponding code, table or other means that can be used to indicate related information in the device (for example, including terminal device and network device), and the specific implementation manner of the present application is not limited. For example, the predefinition can mean the definition in the protocol. It should also be understood that the "protocol" in the embodiments of the present application can mean a standard protocol in the communication field, which can include LTE protocol, NR protocol and related protocols applied to future communication systems, and the present application does not limit this.

[0056] FIG. 1 is a schematic structural diagram of a wireless communication system 100 to which the embodiments of the present application are applied.

[0057] As shown in FIG. 1, the communication system 100 can include a network device 110 and a user equipment (UE) 120. The network device 110 can communicate with the UE 120 through an air interface (also referred to as a Uu interface). The UE 120 and the network device 110 support multiple service transmissions.

[0058] It should be understood that the embodiments of the present application are only exemplarily described with the communication system 100, but the embodiments of the present application are not limited thereto. That is, the technical solutions of the embodiments of the present application can be applied to various communication systems, for example, a Long Term Evolution (LTE) system, an LTE Time Division Duplex (TDD), a Universal Mobile Telecommunication System (UMTS), an Internet of Things (IoT) system, a Narrow Band Internet of Things (NB-IoT) system, an enhanced Machine-Type Communications (eMTC) system, a 5G communication system (also referred to as a New Radio (NR) communication system), or a future communication system, etc.

[0059] The UE in the embodiments of the present application can also be referred to as a terminal device, an access terminal, a user unit, a user station, a mobile station, a mobile station (MS), a mobile terminal (MT), a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, or a user apparatus.

[0060] The UE in the embodiments of the present application can be a device that provides voice and / or data connectivity for a user, and can be used to connect people, things, and machines, for example, handheld devices with wireless connection functions, vehicle-mounted devices, etc.

[0061] The UE in the embodiments of the present application can be a mobile phone, a tablet computer (Pad), a notebook computer, a palm computer, a mobile Internet device (MID), a wearable device, a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, and the like.

[0062] In some embodiments, the UE can be configured to function as a base station. For example, the UE can function as a scheduling entity that provides sidelink signals between UEs in vehicle-to-X (V2X) or device-to-device (D2D) or the like. For example, a cellular phone and a car communicate with each other using sidelink signals, and a cellular phone and a smart home device communicate without relaying the communication signals through a base station.

[0063] The network device in the embodiments of the present application can be a device for communicating with the UE, and the network device can also be referred to as an access network device or a wireless access network device, such as a base station. The network device in the embodiments of the present application can refer to a radio access network (RAN) node (or device) that accesses the UE to a wireless network.

[0064] It should be noted that the base station can be variously named or replaced by the following names in a broad sense, such as: Node B (Node B), evolved Node B (eNB), next generation Node B (gNB), relay station, access point, transmitting and receiving point (TRP), transmitting point (TP), master station MeNB, auxiliary station SeNB, multi-mode wireless node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. The base station can be a macro base station, a micro base station, a relay node, a donor node, or the like, or a combination thereof.

[0065] It should be noted that the UE can communicate with the UE through the sidelink. The sidelink communication can also be referred to as proximity service (ProSe) communication, one-way communication, side link communication, D2D communication, V2X communication.

[0066] At present, the NR system introduces a UE-NW relay technology. This technology supports a remote UE to establish a connection with a network (or a network device) through a relay UE (UE-to-network relay UE). The remote UE can be a UE located outside the coverage range of the network device (hereinafter referred to as network coverage range). Therefore, the UE-NW relay technology can expand the network coverage range.

[0067] As shown in FIG. 1, some UEs (such as UE 120a in FIG. 1) are located within the coverage range of the network device 110, and some UEs (such as UE 120b in FIG. 1) are located outside the network coverage range. The UE 120b located outside the network coverage range can be referred to as a remote UE, and the UE 120a located within the network coverage range can act as a relay UE (or relay node) of the remote UE 120b, thereby establishing a connection between the remote UE 120b and the network.

[0068] Before a remote UE selects a relay UE, a discovery procedure is usually needed to be performed first. The discovery procedure includes two discovery modes, Model A discovery (hereinafter referred to as Model A) and Model B discovery (hereinafter referred to as Model B).

[0069] Referring to a Model A discovery flowchart shown in FIG. 2, in Model A, a relay UE sends (or broadcasts, such as periodically broadcasts) a discovery announcement message. A remote UE discovers and selects a relay UE by monitoring the discovery announcement message.

[0070] The discovery announcement message sent by the relay UE includes a message type, an application layer identity of the relay UE, and a relay service code. For a Layer-2 (L2) relay case, the discovery announcement message also includes cell information in which the L2 relay UE is currently located, an NR Cell Global Identity (NCGI), for L2 remote UE to select a relay UE.

[0071] The source L2 ID and the target L2 ID used in the discovery announcement message are carried in an L2 frame structure. The source L2 ID is assigned by the relay UE, and the target L2 ID is determined according to a configuration. The remote UE determines the target L2 ID to be monitored according to the configuration, thereby monitoring the relay service code corresponding to the service of interest and selecting a relay UE.

[0072] Optionally, the relay UE can also send discovery additional information. It needs to be noted that the discovery additional information can also be used to send additional information that is not directly used for relay discovery.

[0073] Referring to a Model B discovery flowchart shown in FIG. 3, in Model B, a remote UE actively sends a discovery solicitation message, and discovers and selects a relay UE through a discovery response message returned by the relay UE.

[0074] The relay discovery solicitation message sent by the remote UE includes a message type, an application layer identity of the remote UE, and a relay service code.

[0075] The source L2 ID and the target L2 ID used in the discovery solicitation message are carried in an L2 frame structure. The source L2 ID is assigned by the remote UE, and the target L2 ID is determined according to a configuration. The relay service code is the relay service code corresponding to the service of interest of the remote UE. The relay UE determines the target L2 ID to be monitored according to the configuration.

[0076] The relay UE that matches the relay service code in the discovery request message sends a discovery response message to the remote UE, and the discovery response message includes a message type, an application layer identifier of the relay UE, and the relay service code. The source L2 ID of the discovery response message is allocated by the relay UE, and the target L2 ID is the source L2 ID of the request message received by the relay UE.

[0077] [According to Rule 91 Correction 19.08.2024] The current protocol only supports a single-hop scenario, that is, the existing solution only allows one relay UE to exist between the remote UE and the network. The connection scenario of the remote UE 110b-1 and the network device 120 formed by path A in FIG. 1 is a single-hop scenario.

[0078] [According to Rule 91 Correction 19.08.2024] The protocol version R19 will discuss the multi-hop relay scenario. The connection scenario of the remote UE and the network formed by path B in FIG. 1 is a multi-hop scenario. For example, in path B in FIG. 1, the remote UE is UE 120b-1. This UE 120b-1 is connected to the network through three-hop relay UEs (relay UE 120b-2, relay UE 120a-1, and relay UE 120a-2, respectively). Therefore, FIG. 1 forms a topology connection (or network topology connection) of UE 120b-1 -> UE 120b-2 -> UE 120a-1 -> UE 120a-2 -> network device 110.

[0079] It should be noted that the multi-hop scenario can support different topology structures. According to the number of paths supported by the UE, the relay topology structure of the multi-hop scenario can be divided into a single-path topology structure (no MP-like topology) and a multi-path (Mesh) topology structure (MP-like topology).

[0080] In the single-path topology structure, the remote UE and / or the relay UE support relay connection with one parent device, or in other words, the remote UE and / or the relay UE do not support relay connection with multiple parent devices, and each UE is connected to the network through one (or one path).

[0081] It should be noted that the parent device of the remote UE and / or the relay UE can be understood as the last-hop device, or the last-hop node, or the parent node of the remote UE and / or the relay UE.

[0082] In an example, referring to FIG. 4A, a single-path topology structure (no MP-like topology) diagram 1 is provided. Remote UE 1 is connected to gNB through first relay UE 1 and second relay UE 1, and remote UE 2 is connected to gNB through first relay UE 2 and second relay UE 2.

[0083] In another example, a no MP-like topology diagram is provided in FIG. 4B. Remote UE1 connects to the gNB through the first relay UE1 and the second relay UE, and remote UE2 connects to the gNB through the first relay UE2 and the second relay UE. The first relay UE1 and the first relay UE2 can be connected to the same second relay UE.

[0084] In the multi-path topology, the remote UE and / or the relay UE support relaying connection with multiple parent devices.

[0085] Exemplarily, a MP-like topology diagram is provided in FIG. 4C. The remote UE can be connected to the gNB through two different paths. One path is that the remote UE connects to the gNB through the first relay UE and the second relay UE1, and the other path is that the remote UE connects to the gNB through the first relay UE and the second relay UE2.

[0086] It should be understood that in the multi-path topology, the same and / or different remote UEs can be connected to different other relays and / or networks through the same relay UE, for example, the case shown in FIG. 4C.

[0087] In practical applications, the network does not expect to communicate with the remote UE through multiple different paths, or in other words, the network expects to communicate with the remote UE through one path. Therefore, for the multi-path topology, how to further select a path based on relay selection, or how to avoid the case of communicating with the remote UE through multiple different paths is a problem to be solved.

[0088] Based on this, the embodiment of the present application provides a communication method which can be applied to a multi-hop scenario. The first device can receive a first discovery message sent by one or more second devices, wherein the first discovery message carries information about one or more first paths supported by the second device. In this way, the first device can select a target relay device and a target path according to the one or more first paths supported by the one or more second devices. It can be seen that the first discovery message can carry information about a link that the first device cannot directly observe, so that the first device can select a more suitable target relay device and target path based on the first discovery message.

[0089] In order to facilitate understanding of the technical solutions of the embodiments of the present application, the technical solutions of the present application are described in detail below through specific embodiments. The above related technologies can be combined with the technical solutions of the embodiments of the present application as optional schemes, which all belong to the protection scope of the embodiments of the present application. The embodiments of the present application include at least part of the following contents.

[0090] It should be noted that the device in the embodiments of the present application can be referred to as a UE, and can also be referred to as a node, and the three are equivalent or replaceable. For example, the first device can also be referred to as a first UE or a first node. The second device can also be referred to as a second UE or a second node, and the third device can also be referred to as a third UE or a third node.

[0091] It should be further noted that the channel quality in the embodiments of the present application can also be referred to as link quality, and the two are equivalent or replaceable.

[0092] FIG. 5 shows a communication method provided by the embodiments of the present application, which can include steps S510 and S520.

[0093] S510, the second device sends a first discovery message, and correspondingly, the first device receives the first discovery message.

[0094] S520, the first device selects a target relay device and / or a target path based on the first discovery message.

[0095] It should be noted that the first device can be a remote UE, for example, the first device can be a UE outside the network coverage, or a UE at the edge of the network coverage, or a UE with poor signal quality, and the embodiments of the present application do not limit this.

[0096] It should be further noted that the second device is a device capable of providing relay service, and the second device can be referred to as a relay UE. It can be understood that the second device can establish a connection with the network device, and provide relay service from the remote UE to the network device to the remote UE through the connection between the second device and the network device.

[0097] It should be understood that the second device can be directly connected with the network device, or the second device can be connected with the network device through other relay devices, and the embodiments of the present application do not limit this.

[0098] In the embodiments of the present application, the transmission path between the second device and the network device is referred to as a first path. The first path can include a single-hop or a multi-hop link. The multi-hop link can be composed of multiple single-hop links.

[0099] It should be noted that one single-hop link in a path can be understood as a link directly connecting two adjacent devices in the path. One path can include one or more single-hop links. Exemplarily, referring to FIG. 1, path A can include two-hop links (which can also be understood as including two single-hop links), the first-hop link being the link from UE 120b to UE 120a, and the second-hop link being the link from UE 120a to network device 110. Path B can include four-hop links (which can also be understood as including four single-hop links), the first-hop link being the link between UE 120b-l and UE 120b-2, the second-hop link being the link between UE 120b-2 and UE 120a-l, the third-hop link being the link between UE 120a-l and UE 120a-2, and the fourth-hop link being the link between UE 120a-2 and network device 110.

[0100] It should be understood that if the second device is directly connected to the network device, the first path includes only one single-hop link, i.e., the link between the second device and the network device. If the second device is connected to the network device through other relay UEs, the first path includes two or more single-hop links.

[0101] It should also be understood that the transmission path between the second device and the network device (i.e., the first path) can include one or more. That is, the second device can establish a connection with the network device through one or more first paths, or in other words, the second device supports one or more first paths.

[0102] It should be noted that among the one or more first paths supported by the second device, at least one first path includes a multi-hop link.

[0103] Exemplarily, referring to the topological structure diagram shown in FIG. 6, the second device can be connected to the network device through two first paths, first path A and first path B.

[0104] In an implementation, for a single-path topological structure scenario, i.e., a scenario in which the network does not allow the same relay UE to be connected to different parent devices, the second device can establish a relay connection with the network device through one first path, i.e., there is only one transmission path between the second device and the network device. Exemplarily, assuming that the second device is the first relay UE 1 in FIG. 4A, the first relay UE 1 only supports accessing the gNB through the first relay UE 1.

[0105] In another implementation, for a scenario of a multi-path topology, i.e., a scenario in which the network allows the same relay UE to connect to different parent devices, the second device can establish a relay connection with the network device through one or more first paths. Exemplarily, assuming that the second device is the first relay UE in FIG. 4C, the first relay UE can connect with the gNB through the second relay UE1, and the first relay UE can also connect with the gNB through the second relay UE2.

[0106] In an embodiment of the present application, the second device can send a first discovery message, and through the first discovery message, inform other devices of its capability of providing relay service, so that the first device receiving the first discovery message can determine whether to select the second device as a relay UE according to the first discovery message.

[0107] The information carried in the first discovery message is described below.

[0108] In some embodiments, the first discovery message can include relevant information of each first path supported by the second device.

[0109] The relevant information of each first path includes one or more of the following:

[0110] The relevant information of the network device accessed by the first path;

[0111] Quality of Service (QoS) information supported by the first path;

[0112] The relevant information of each hop link in the first path.

[0113] It should be understood that the second device can establish a connection with the network device through the first path, or in other words, the second device can access the network device through the first path. The relevant information of the network device accessed by the first path can be included in the first discovery message.

[0114] In some embodiments, the relevant information of the network device includes one or more of the following:

[0115] Cell identification information;

[0116] Maximum supported hop count;

[0117] Whether to support IDLE or INACTIVE devices to provide relay service.

[0118] It should be noted that the relevant information of the network device can be configured by the network device, or in other words, the relevant information of the network device is determined according to the configuration information sent by the network device.

[0119] In an example, if the second device is directly connected with the network device, the second device can receive the configuration information sent by the network device through the Uu interface, and determine the related information of the network device based on the configuration information.

[0120] In another example, if the second device is relay connected with the network device through other device (e.g. the third device), the second device can receive the configuration information of the network device forwarded by the third device through the PC5 interface, and determine the related information of the network device based on the configuration information.

[0121] In some embodiments, the QoS information supported by the first path can include one or more of the following:

[0122] the latency information of the first path (including one or more of the average latency, the maximum latency, the minimum latency);

[0123] the traffic information of the first path (including one or more of the average traffic, the maximum traffic, the minimum traffic);

[0124] the error probability information of the first path;

[0125] the QoS level of the first path (e.g. dividing the latency information, the traffic information and the error probability information into N levels).

[0126] It should be noted that the QoS information supported by the first path can be predefined or configured by the network device. Alternatively, the QoS information supported by the first path is determined according to predefined information or configuration information sent by the network device.

[0127] In an example, if the second device is directly connected with the network device, the second device can receive the configuration information sent by the network device through the Uu interface, and determine the QoS information supported by the first path based on the configuration information.

[0128] In another example, if the second device is relay connected with the network device through other device (e.g. the third device), the second device can receive the configuration information of the network device forwarded by the third device through the PC5 interface, and determine the QoS information supported by the first path based on the configuration information.

[0129] It should be understood that the first path can include a single-hop link or a multi-hop link. In some embodiments, the related information of the single-hop link in the first path, or the related information of each hop link (which can be understood as each single-hop link in the multi-hop link) in the multi-hop link of the first path includes one or more of the following:

[0130] the channel quality between the two devices on the link;

[0131] the QoS information supported by the link;

[0132] a Radio Resource Control (RRC) state of the child device in the link;

[0133] identification information (e.g., L2 ID, User Info, IP address, etc.) of the child device in the link.

[0134] It should be understood that each hop link in the first path refers to a transmission link between any two adjacent devices in the first path. Each hop link can correspond to two devices, i.e., a parent device and a child device.

[0135] In an example, referring to FIG. 6, in the first path A, the second device is directly connected to the network device, and the first path A includes one single-hop link, i.e., a link between the second device and the network device. The link between the second device and the network device can be referred to as a Uu link, and the network device can be a parent device in the Uu link, and the second device can be a child device in the Uu link.

[0136] In another example, referring to FIG. 6, in the first path B, the second device is relayed to the network device through a third device, and the first path B can include two-hop links (or two single-hop links). Among them, the first hop link in the first path B can be a Uu link, the parent device in the Uu link is the network device, and the child device in the Uu link is the third device. In addition, the second hop link in the first path B can be a PC5 link, the parent device in the PC5 link is the third device, and the child device is the second device.

[0137] It should be noted that the channel quality between the two devices on the link can be understood as the link quality between the parent device and the child device on the link, or the channel quality corresponding to the link.

[0138] In some embodiments, the channel quality can be a channel measurement result of the link, and / or a parameter capable of indicating the channel quality, such as a channel measurement result level. Illustratively, the channel quality result can be divided into N levels, N being an integer greater than 1.

[0139] It should be noted that the channel measurement result can be a measurement value of a L1 / L3 corresponding Reference Signal Received Power (RSRP), Reference Signal Receiving Quality (RSRQ), and / or Signal to Interference plus Noise Ratio (SRNR).

[0140] It should be noted that the channel quality between the two devices on each hop link can be measured by the child device in the link based on one or more of the following information transmitted between the two devices on the link:

[0141] a sidelink reference signal;

[0142] a sidelink data channel;

[0143] a sidelink control channel;

[0144] a second discovery message;

[0145] a downlink reference signal;

[0146] a downlink data channel;

[0147] a downlink control channel.

[0148] In an embodiment, if the link is a Uu link, i.e., a link between a network device and a UE, the child device in the Uu link can measure one or more of the downlink reference signal, the downlink data channel, and the downlink control channel transmitted by the network device to obtain the channel quality of the current link.

[0149] It should be noted that the downlink reference signal can include but is not limited to a synchronization signal block (SSB), a channel state information reference signal (CSI-RS), a downlink positioning reference signal (PRS), a demodulation reference signal (DMRS), etc. The downlink data channel can be a physical downlink shared channel (PDSCH), and the downlink control channel can be a physical downlink control channel (PDCCH).

[0150] In another embodiment, if the link is a PC5 link, i.e., a link between UEs, the child device in the PC5 link can measure one or more of the sidelink reference signal, the sidelink data channel, and the sidelink control channel transmitted by the parent device to obtain the channel quality of the current link.

[0151] It should be noted that the sidelink reference signal can include but is not limited to a discovery reference signal (DRS), a sidelink PRS, a sidelink DMRS, etc. The sidelink data channel can be a physical sidelink shared channel (PSSCH), and the sidelink control channel can be a physical sidelink control channel (PSCCH).

[0152] In some embodiments, the QoS information supported by each hop link includes one or more of the following:

[0153] latency information (including one or more of average latency, maximum latency, minimum latency);

[0154] traffic information (including one or more of average traffic, maximum traffic, minimum traffic);

[0155] error probability information;

[0156] QoS level (e.g., dividing the latency information, traffic information, and error probability information into N levels).

[0157] It should be noted that the QoS information supported by each hop link in the single-hop link or the multi-hop link can be configured by the network (e.g., configured through dedicated RRC information or SIB information) or measured / estimated by the child device or the parent device in the link based on implementation.

[0158] It should be noted that the QoS information supported by each hop link in the single-hop link or the multi-hop link can be configured per resource pool and / or per constant bit rate (CBR) level, and the embodiments of the present application do not limit this.

[0159] It should also be noted that the related information of the link directly connected to the second device can be determined by the second device. For example, for the first path B of FIG. 6, the second device can measure the SL reference signal, PSSCH, PSCCH, and the second discovery message (see the description below) sent by the third device to obtain the channel quality (e.g., the measurement value of the RSRP / RSRQ / SINR corresponding to L1 / L3) of the PC5 link and / or the channel quality level; the second device can also determine the QoS information of the PC5 link based on the network device configuration (e.g., through the third device forwarding the RRC configuration information of the network) or based on implementation measurement / estimation.

[0160] The information about the link not directly connected with the second device can be sent by the parent device of the second device through the discovery information. For example, for the first path B in FIG. 6, the second device can receive the discovery message sent by the third device, and obtain the information about the Uu link between the third device and the network device through the discovery message sent by the third device.

[0161] It should be understood that the first discovery message can include the QoS information supported by the first path, or can include the QoS information supported by each hop link in the single-hop link or the multi-hop link in the first path. That is, the first discovery message can configure the QoS information in the unit of path or in the unit of each hop link in the path. For example, for the first path B shown in FIG. 6, the first discovery message can indicate that the latency of the first path is 7 ms, and the first discovery message can also indicate that the latency of the Uu link is 3 ms and the latency of the PC5 link is 4 ms.

[0162] It should be noted that the information about each first path supported by the second device can be carried in the RRC container of the first discovery message.

[0163] The method provided by the embodiments of the present application can be applied to a multi-hop scenario, and the information about the Uu link and the PC5 link that cannot be directly observed by the remote UE can be carried in the discovery message, so that the remote UE can better select a suitable relay and path after receiving the discovery message.

[0164] In some embodiments, the number of second devices is one or more, and the one or more second devices each send a first discovery message. Different second devices can correspond to different first discovery messages.

[0165] Correspondingly, the first device can receive the first discovery message sent by the one or more second devices, and then the first device can select a suitable target relay device and / or a suitable path to access the network according to the first discovery message sent by the one or more second devices.

[0166] It should be noted that the network allows the device to be connected to multiple parent devices (for example, the scenario shown in FIG. 4C), and the network does not allow the device to be connected to multiple parent devices (for example, the scenarios shown in FIG. 4A and FIG. 4B), and the selection manner of the first device according to the first discovery message can be different.

[0167] In an embodiment of the present disclosure, for the scenario that the network allows the device to connect to multiple parent devices, i.e., the first device supports connection with multiple parent devices, and / or one or more second devices support connection with multiple parent devices. In this scenario, there can be multiple paths between the device and the network, and the first device can select a target relay device and / or a target path according to the received one or more first discovery messages.

[0168] In an embodiment, after receiving the one or more first discovery messages, the first device can select one or more appropriate second devices from the one or more second devices that send the first discovery messages to obtain a target relay device. If the selected target relay device supports only one first path, the first device can not select a path. If the selected target relay device supports multiple first paths, the first device can further select one or more appropriate first paths from the multiple first paths supported by the target relay device as target paths.

[0169] In another embodiment, after receiving the one or more first discovery messages, the first device can directly select one or more appropriate first paths from the multiple first paths supported by the multiple second devices that send the first discovery messages as the target paths.

[0170] The principles / conditions for the first device to select the target relay device and / or the target path according to the first discovery messages can include one or more of the following:

[0171] The target relay device is a second device in the one or more second devices whose channel quality with the first device is better than a first threshold value;

[0172] The target path is a path in the first paths whose supported QoS information meets the QoS requirement information of the first device;

[0173] The target path is a path in the first paths whose supported QoS information is optimal;

[0174] The hop count of the target path is less than or equal to a maximum hop count;

[0175] The hop count of the target path is a path in the first paths whose hop count is the least;

[0176] The link quality of each hop link of the target path is better than a second threshold value corresponding to each hop link;

[0177] The RRC state of each device in the target path meets a first condition;

[0178] The identification information of each device in the target path meets a second condition;

[0179] The network device accessed by the target path meets a third condition.

[0180] It should be noted that the first threshold value can be predefined or configured by the network device. That is, the first threshold value can be determined according to predefined information or network device configuration information (for example, directly receiving configuration information sent by the network device, or based on historical configuration information of the network, or forwarding the configuration information of the network through the relay, etc.).

[0181] It should be understood that the predefinition can be understood as being realized by pre-storing corresponding codes, tables or other means for indicating related information in the device, and the specific implementation manner thereof is not limited in the present application. The predefinition can also refer to the definition in the protocol.

[0182] It should be noted that the first threshold value can reuse the threshold value of the relay in the single-hop scenario. The first threshold value can also be a threshold value introduced specifically for the multi-hop scenario. For example, for the multi-hop scenario, since the number of hops is more and the link failure is more likely to occur compared with the single-hop, better channel quality is needed to ensure the relay communication quality, and therefore the first threshold value can be greater than the threshold value of the relay in the single-hop scenario. In this way, the multi-hop relay scenario can be more flexibly adapted.

[0183] In addition, the second threshold value corresponding to each hop link can also be predefined or configured by the network device. That is, the second threshold value can be determined according to the predefined information or the network configuration information.

[0184] It should be noted that for the first path, the second threshold values corresponding to the respective links can be the same or different.

[0185] In an embodiment, the second threshold values corresponding to all PC5 links in the first path can be the same. The second threshold value corresponding to the PC5 link is different from the second threshold value corresponding to the Uu link.

[0186] In another embodiment, in each hop link of the first path, the second threshold values corresponding to the links of different hops are different.

[0187] It should be noted that the maximum number of hops, and / or the second threshold information corresponding to each hop link is related to the service corresponding to the to-be-transmitted data, or in other words, related to the RSC. It can be understood that different services can correspond to different maximum numbers of hops and / or second threshold values.

[0188] It should be understood that the first condition can be that the RRC states of the devices in the path are all in the connected state, or the RRC state is in the non-idle state, etc. That is, the first device can select the first path in which all the devices are in the connected state or the RRC state is in the connected state or the inactive state as the target path. Or, the RRC state of the device in the target path selected by the first device is in the connected state or the RRC state is in the connected state or the inactive state.

[0189] It should be noted that the second condition can be that the identification information of the device in the path is the identification information in the preset identification information set. That is, the first device can select a specific device as a relay in the target path.

[0190] It should be further noted that the third condition can be that the network device supports IDLE / INACTIVE relay. That is, the first device can select a path that supports IDLE / INACTIVE relay.

[0191] It should be further noted that one or more of the above first condition to the third condition can be predefined, or can be configured by the network device, for example, configured by the historical configuration information of the network, or configured by the configuration information of the relay forwarding network.

[0192] It should be further noted that based on the above principles / conditions, if the target relay device selected by the first device includes multiple second devices, and / or the target path includes multiple first paths, the first device can communicate with the network device through multiple second devices and / or multiple first paths. Alternatively, the first device can select one second device and / or one first path from the multiple second devices and / or multiple first paths to communicate with the network device, for example, the first device can select one of the multiple second devices and / or one of the multiple first paths based on an implementation or a random manner.

[0193] In an embodiment of the present application, for the scenario in which the network does not allow the device to connect to multiple parent devices, that is, the first device supports connection with one parent device, and the above one or more second devices support connection with one parent device. In this scenario, there is only one path between the device and the network, and in this scenario, the first device selects the target relay device, that is, selects the target path, and the target relay device supports one first path, which is the target path.

[0194] That is, for the scenario in which the network does not allow the device to connect to multiple parent devices, the first device selects the target relay device and / or the target path based on the first discovery message sent by the one or more second devices in S520 can be implemented in the following manner: the first device selects the target relay device based on the first discovery message sent by the one or more second devices.

[0195] The principle / condition for the first device to select the target relay device according to the first discovery message comprises one or more of the following:

[0196] The target relay device is a second device of the one or more second devices, and a channel quality between the first device and the second device is better than a first threshold value.

[0197] QoS information of a first path supported by the target relay device meets QoS requirement information of the first device;

[0198] The QoS information of the first path supported by the target relay device is optimal;

[0199] A hop number of the first path supported by the target relay device is less than or equal to a maximum hop number;

[0200] The hop number of the first path supported by the target relay device is minimal;

[0201] A link quality of each hop link in the first path supported by the target relay device is better than a second threshold value corresponding to the each hop link;

[0202] An RRC state of each device in the first path supported by the target relay device meets a first condition;

[0203] Identification information of each device in the first path supported by the target relay device meets a second condition;

[0204] A network device accessed by the first path supported by the target relay device meets a third condition.

[0205] It should be noted that the first threshold value, the second threshold value corresponding to each hop link, the maximum hop number, the first condition, the second condition, and the third condition can refer to the description in the above embodiments, and will not be described here for brevity.

[0206] It should also be noted that based on the above principles / conditions, if the target relay device selected by the first device includes multiple second devices, the first device can communicate with the network device through the first paths corresponding to the multiple second devices. Alternatively, the first device can select one second device from the multiple second devices to communicate with the network device, for example, the first device can select one of the multiple second devices based on an implementation or a random manner.

[0207] The method provided by the embodiments of the present application can be applied to a multi-hop scenario, wherein the first device can receive a first discovery message sent by one or more second devices, wherein the first discovery message carries information about one or more first paths supported by the second device. In this way, the first device can select a target relay device and a target path according to the one or more first paths supported by the one or more second devices. As can be seen, the first discovery message can carry information about a link that cannot be directly observed by the first device, so that the first device can select a more suitable target relay device and target path based on the first discovery message.

[0208] It should be noted that the first discovery message can be a first discovery announcement message or a first discovery response message. For example, the second device is a UE based on mode A, and the first discovery message is a first discovery announcement message. For another example, the second device is a UE based on mode B, and the first discovery message is a first discovery response message. The embodiments of the present application do not limit the type of the first discovery message.

[0209] In some embodiments, with reference to the flowchart shown in FIG. 7, when the first discovery message is a first discovery response message, the following steps can be further included before S510:

[0210] S500, the first device sends a first discovery request message; correspondingly, the second device receives the first discovery request message.

[0211] It should be understood that the first device can send the first discovery request message according to a configuration of an upper layer (Prose layer).

[0212] In some embodiments, the first discovery request message includes one or more of the following:

[0213] End to End (E2E) QoS requirement information;

[0214] Maximum hop count;

[0215] A second threshold value corresponding to each hop link.

[0216] In some embodiments, the E2E QoS requirement information can include one or more of the following:

[0217] Delay information (including one or more of average delay, maximum delay, and minimum delay) between the first device and a network device;

[0218] Traffic information (including one or more of average traffic, maximum traffic, and minimum traffic) between the first device and the network device;

[0219] Error probability information between the first device and the network device;

[0220] QoS requirement level between the first device and the network device.

[0221] It should be noted that the end-to-end QoS requirement information can be determined based on one or more of the following:

[0222] Configuration information of a Proximity Service (ProSe) layer in the first device;

[0223] Implementation of the first device;

[0224] QoS information corresponding to the data to be transmitted.

[0225] That is, the E2E QoS requirement information can be configured by the ProSe layer, or determined by the first device based on implementation, or obtained according to the QoS of the data triggering the relay service, and the embodiments of the present application do not limit this.

[0226] It should also be noted that the maximum number of hops in the E2E QoS requirement information, and / or the second threshold information corresponding to each hop link, is related to the service corresponding to the data to be transmitted, or in other words, is related to the RSC. It can be understood that different services can correspond to different maximum numbers of hops and / or second threshold values.

[0227] In the communication method provided by the embodiments of the present application, when the first device (remote UE) sends the first discovery request message, the first device can carry the requirement information of the first device for the relay path in the first discovery request message, so as to find a more suitable target path.

[0228] It should be understood that the first discovery message in the embodiments of the present application can include related information of each of one or more first paths supported by the second device. The second device can inform the first device of the related information of one or more first paths supported by the second device through the first discovery message, so that the first device receiving the first discovery message can determine whether the second device can be selected as a relay UE according to the first discovery message.

[0229] It should be noted that the manner of determining the related information of the first path can be different for different second devices.

[0230] In some embodiments, referring to the information interaction diagram shown in FIG. 8A, if the second device is close to the network device, the second device can be directly connected to the network device, that is, the first path supported by the second device can be a Uu link between the second device and the network device, and then the second device can obtain the related information of the first path (i.e., the Uu link between the second device and the network device) according to the network information sent by the network device.

[0231] Exemplarily, the network information can comprise relevant information of the network device, wherein the relevant information of the network device can comprise one or more of the following: cell identification information, maximum hop count supported by the network device, whether the network device supports providing relay service for an idle-state or inactive-state device.

[0232] Exemplarily, the network information can also comprise resource configuration information of a downlink reference signal (or a downlink data channel, a downlink control channel), so that the second device can perform measurement on a resource of the downlink reference signal (or the downlink data channel, the downlink control channel) according to the relevant configuration information of the downlink reference signal (or the downlink data channel, the downlink control channel), to obtain a corresponding channel quality on a Uu link between the second device and the network device.

[0233] Exemplarily, the network information can further comprise relay and / or path selection related configuration information, for example, a first threshold value, a second threshold value, a maximum hop count, a first condition, a second condition, a third condition, etc., which are not limited by embodiments of the present application.

[0234] That is, in this scenario, the first discovery message sent by the second device is related to the network information, and specifically, the first discovery message can be determined based on the network information.

[0235] In some embodiments, referring to the information interaction diagram two shown in FIG. 8B, if the second device is far away from the network device, the second device cannot be directly connected to the network device, and then the second device can receive the second discovery message sent by the third device (S502). In this way, the second device can determine the relevant information of one or more first paths supported by the second device based on the second discovery message.

[0236] That is, the first discovery message sent by the second device can be related to the second discovery message, and specifically, the first discovery message can be determined based on the second discovery message.

[0237] It should be noted that the second discovery message can comprise relevant information of each second path of one or more second paths supported by the third device. It should be understood that the second path is a transmission path between the third device and the network device, and the second path can comprise a single-hop or multi-hop link.

[0238] In embodiments of the present application, the relevant information of the second path comprises one or more of the following:

[0239] relevant information of a network device accessed by the second path;

[0240] QoS information supported by the second path;

[0241] relevant information of each hop link in the second path.

[0242] It should be understood that the third device can establish a connection with the network device through the second path, or in other words, the third device can access the network device through the second path. The first discovery message can include relevant information of the network device accessed by the second path.

[0243] In some embodiments, the relevant information of the network device includes one or more of the following:

[0244] cell identification information;

[0245] supported maximum number of hops;

[0246] whether to support idle or inactive state devices providing relay services.

[0247] It should be noted that the relevant information of the network device can be configured by the network device, or in other words, the relevant information of the network device is determined according to the configuration information sent by the network device.

[0248] In an example, if the third device is directly connected to the network device, the third device can receive the configuration information sent by the network device through the Uu interface, and determine the relevant information of the network device based on the configuration information.

[0249] In another example, if the third device is relay connected to the network device through other devices, the third device can receive the configuration information of the network device forwarded by the other devices through the PC5 interface, and determine the relevant information of the network device based on the configuration information.

[0250] In some embodiments, the QoS information supported by the second path can include one or more of the following:

[0251] latency information of the second path (including one or more of average latency, maximum latency, and minimum latency);

[0252] traffic information of the second path (including one or more of average traffic, maximum traffic, and minimum traffic);

[0253] error probability information of the second path;

[0254] QoS level of the second path (e.g., dividing the latency information, traffic information, and error probability information into N levels).

[0255] It should be noted that the QoS information supported by the second path can be predefined or configured by the network device. Or in other words, the QoS information supported by the second path is determined according to the predefined information or the configuration information sent by the network device.

[0256] In an example, if the third device is directly connected with the network device, the third device can receive the configuration information sent by the network device through the Uu interface, and determine the QoS information supported by the second path based on the configuration information.

[0257] In another example, if the third device is relay connected with the network device through another device, the second device can receive the configuration information of the network device forwarded by the another device through the PC5 interface, and determine the QoS information supported by the second path based on the configuration information.

[0258] It should be understood that the second path can include a single-hop link or a multi-hop link. In some embodiments, the relevant information of the single-hop link in the second path, or the relevant information of each hop link in the multi-hop link of the second path includes one or more of the following:

[0259] channel quality between two devices on the link;

[0260] QoS information supported by the link;

[0261] RRC state of a child device in the link;

[0262] identification information (e.g., L2 ID, User Info, IP address, etc.) of a child device in the link.

[0263] It should be noted that the relevant content of the relevant information of each hop link in the second path can refer to the description of the relevant information of each hop link in the first path in the foregoing description, and will not be described here for brevity.

[0264] It should be noted that the relevant information of each second path supported by the third device can be carried in the RRC container of the second discovery message.

[0265] It should be further noted that the number of third devices is one or more, and each of the one or more third devices sends a second discovery message, wherein different third devices can correspond to different second discovery messages. Correspondingly, the second device can receive the second discovery message sent by the one or more third devices.

[0266] It should be understood that the one or more first paths supported by the second device can be related to the one or more second paths supported by the one or more third devices.

[0267] In an embodiment of the present application, for the scenario that the network allows the device to be connected to multiple parent devices, i.e., the second device supports connection with multiple parent devices, and / or the one or more third devices support connection with multiple parent devices, there can be multiple paths between a device and the network; the one or more first paths supported by the second device and the one or more second paths supported by the third device can include:

[0268] The one or more first paths supported by the second device are composed of a link between the second device and one or more third devices, and the one or more second paths supported by the third device.

[0269] Exemplarily, referring to the topological structure diagram shown in FIG. 9, the third device 1 can be directly connected with the network device, and the second path (denoted as the second path C in this example) supported by the third device 1 is a Uu link between the network device and the third device 1. In addition, the third device 2 can be directly connected with the network device or connected with the network device in relay through the third device 1, that is, the third device 2 supports two second paths, wherein the second path A includes a Uu link between the network device and the third device 1 and a PC5 link between the third device 1 and the third device 2, and the second path B includes a Uu link between the network device and the third device 2.

[0270] The second device can receive the second discovery messages sent by the third device 1 and the third device 2, and can establish a connection with the third device 1 or the third device 2. Based on this, for the scenario in which the network allows the device to be connected to multiple parent devices, the second device can support three first paths. Among them, the first path A can include the second path A and a PC5 link between the third device 2 and the second device, the first path B includes the second path B and a PC5 link between the third device 2 and the second device, and the first path C includes the second path C and a PC5 link between the third device 1 and the second device.

[0271] In an embodiment of the present application, for the scenario in which the network does not allow the device to be connected to multiple parent devices, that is, the scenario in which the second device supports connection with one parent device and the one or more third devices support connection with one parent device, in this scenario, there is only one path between the device and the network. In this scenario, the one or more first paths supported by the second device are related to the one or more second paths supported by the third device, and can be that the first path supported by the second device is composed of a link between the second device and a target third device, and the second path supported by the target third device; wherein the target third device can be one of the one or more third devices.

[0272] In a possible implementation, if the second device has established a relay connection to the network device, and the parent device of the second device is the target third device, the first discovery message can be determined based on the second discovery message sent by the target third device in the second discovery messages sent by the one or more third devices.

[0273] It should be noted that establishing the relay connection to the network device does not mean establishing the RRC connection, and the second device can be in the IDLE / INACTIVE state. The second device can also be referred to as establishing the relay connection to the network device by listening to the SIB or the paging (Paging) message of the network through the relay connection.

[0274] It should be understood that the second device can receive the second discovery message sent by one or more third devices. Since the second device has established a relay connection to the network device through the target third device, the second device can determine the first discovery message sent by itself according to the second discovery message sent by the target third device. For example, the first discovery message can include: related information in the second discovery message, and / or link related information between the target third device and the second device.

[0275] In another possible implementation, if the second device does not establish a relay connection to the network device, after the second device receives the second discovery message sent by one or more third devices, the second device can further perform the following steps:

[0276] The second device selects the target third device based on the second discovery message sent by the one or more third devices.

[0277] It should be understood that for the scenario in which the network does not allow the device to connect to multiple parent devices, that is, the second device supports connection with one parent device, and the one or more third devices support connection with one parent device. In this scenario, the device is required to support only one path. Therefore, when the number of the one or more third devices includes multiple, the second device needs to select a suitable target third device from the multiple third devices. In this way, the first path of the second device can be a second path supported by the target third device plus a PC5 link between the target third device and the second device.

[0278] In some embodiments, the second device selects the target third device based on one or more of the following:

[0279] The target third device is a third device in the one or more third devices, and the channel quality between the second device and the third device is better than a third threshold value;

[0280] The QoS information corresponding to the second path supported by the target third device meets the QoS requirement information of the second device;

[0281] The QoS information corresponding to the second path supported by the target third device is optimal;

[0282] The number of hops of the second path supported by the target third device is less than or equal to a maximum number of hops;

[0283] The number of hops of the second path supported by the target third device is the least;

[0284] a link quality of each hop link in the second path supported by the target third device is better than a second threshold value corresponding to the each hop link;

[0285] an RRC state of each device in the second path supported by the target third device satisfies a first condition;

[0286] identification information of each device in the second path supported by the target third device satisfies a second condition;

[0287] a network device accessed by the second path supported by the target third device satisfies a third condition.

[0288] It should be noted that the third threshold value can be predefined or configured by the network device. That is, the third threshold value can be determined according to predefined information or network device configuration information (for example, directly receiving configuration information sent by the network device, or based on historical configuration information of the network, or forwarding the configuration information of the network through the relay).

[0289] It should also be noted that the third threshold value can reuse the threshold value of the relay in the single-hop scenario. The third threshold value can also be a threshold value introduced specifically for the multi-hop scenario. For example, for the multi-hop scenario, since the number of hops is more, it is more likely to occur link failure compared to single-hop, and better channel quality is needed to ensure relay communication quality, so the third threshold value can be greater than the threshold value of the relay in the single-hop scenario. In this way, the multi-hop relay scenario can be more flexible and adaptive.

[0290] In addition, the second threshold value corresponding to each hop link can also be predefined or configured by the network device. That is, the second threshold value can be determined according to predefined information or network configuration information.

[0291] It should be noted that for the second path, the second threshold values corresponding to each link can be the same or different.

[0292] In an embodiment, the second threshold values corresponding to all PC5 links in the second path can be the same. The second threshold value corresponding to the PC5 link is different from the second threshold value corresponding to the Uu link.

[0293] In another embodiment, in each hop link of the second path, the second threshold values corresponding to the links of different hops are different.

[0294] It should be noted that the maximum number of hops, and / or the second threshold information corresponding to each hop link is related to the service corresponding to the data to be transmitted, or in other words, related to RSC. It can be understood that different services can correspond to different maximum number of hops and / or second threshold values.

[0295] It should be understood that the first condition can be that the RRC states of the devices in the second path are all in a connected state, or the RRC states are in a non-idle state, and the like.

[0296] It should be noted that the second condition can be that the identification information of the devices in the path is identification information in a preset identification information set.

[0297] It should be further noted that the third condition can be that the network device supports IDLE / INACTIVE relaying.

[0298] It should be further noted that one or more of the first condition to the third condition described above can be predefined or configured by the network device, for example, configured by historical configuration information of the network or configuration information of the network forwarded by the relay.

[0299] In some embodiments, to guarantee the communication quality of the relay transmission, the second device can further determine whether to send the first discovery message before sending the first discovery message.

[0300] In the embodiments of the present application, the second device can send the first discovery message when one or more of the following conditions are met:

[0301] The channel quality between the second device and the one or more third devices is better than a fourth threshold value;

[0302] The number of hops of the path between the second device and the network device on which the relay connection has been established is less than a maximum number of hops.

[0303] It can be understood that the second device can measure one or more of the sidelink reference signal, the sidelink data channel, and the sidelink control channel sent by the third device to determine the channel quality between the second device and the third device. The second device can send the first discovery message when the channel quality between the second device and the one or more third devices is good (better than the fourth threshold value).

[0304] In an implementation, the fourth threshold value can be predefined or configured by the network device. That is, the fourth threshold value can be determined according to predefined information or network device configuration information (for example, directly receiving configuration information sent by the network device, or based on historical configuration information of the network, or configuration information of the network forwarded by the relay).

[0305] It should be further noted that the fourth threshold value can reuse the threshold value of the relay in the single-hop scenario. The fourth threshold value can also be a threshold value introduced specifically for the multi-hop scenario. For example, for the multi-hop scenario, since the number of hops is more likely to cause link failure compared to single-hop, better channel quality is needed to ensure relay communication quality, and therefore the fourth threshold value can be greater than the threshold value of the relay in the single-hop scenario. In this way, the multi-hop relay scenario can be more flexible and adaptive.

[0306] In another embodiment, the fourth threshold value can be determined according to a first discovery request message sent by the first device; wherein the first discovery request message comprises a second threshold value corresponding to each hop link; correspondingly, the fourth threshold value is determined based on the hop number corresponding to the link between the second device and one or more third devices and the second threshold value.

[0307] In the embodiments of the present application, if the second device has established a relay connection to the network device, the second device can further determine whether the hop number of the path of the established relay connection is less than the requirement of the maximum hop number. The second device can send the first discovery message when the hop number of the relay connection is less than the limit of the maximum hop number.

[0308] It should be noted that if the second device is close to the network device and can be directly connected to the network device, the second device can determine whether the channel quality between the second device and the network device satisfies the condition, and the second device can send the first discovery message when the channel quality between the second device and the network device is better than the fourth threshold value.

[0309] It should be understood that the second device can measure one or more of the downlink reference signal, the downlink data channel and the downlink control channel from the network device to determine the channel quality between the second device and the network device.

[0310] It should be further noted that the second device can send the first discovery message in a broadcast manner.

[0311] In some embodiments, the above discovery process can be a mode A discovery process, that is, the first discovery message in the above discovery process is a first discovery announcement message, and the second discovery message is a second discovery announcement message.

[0312] It can be understood that the second device can receive the second discovery announcement message of one or more third devices, and send the first discovery announcement message based on the second discovery announcement message.

[0313] In some embodiments, the above discovery process can be a mode B discovery process. For the mode B discovery process, the above first discovery message can be a first discovery response message, and the second discovery message can be a second discovery response message. Based on this, the embodiments of the present application can further comprise the following steps:

[0314] The second device receives the first discovery request message sent by the first device, and the first discovery response message is associated with the first discovery request message;

[0315] Alternatively,

[0316] The second device receives the second discovery request message sent by another second device.

[0317] In a possible implementation, as shown in FIG. 7, if the second device is close to the first device and can be directly connected with the first device, the second device can receive the first discovery request message sent by the first device. Correspondingly, the second device can feed back the first discovery response message (i.e., the first discovery message) to the first device in response to the first discovery request message sent by the first device. The sending of the first discovery response message can enable the first device to select a target relay device and / or a target path and establish a relay connection with the network according to the first discovery response message.

[0318] In another possible implementation, if the second device is far away from the first device and cannot be directly connected with the first device, the second device can receive the second discovery request message sent by the other second device. Correspondingly, the second device can feed back the first discovery response message (i.e., the first discovery message) to the other second device in response to the second discovery request message sent by the other second device. The sending of the first discovery response message can enable the other second device to select a target relay device and / or forward the first discovery response message, so that the first device located at a remote end can select a target relay device and / or a target path and establish a relay connection with the network.

[0319] It should be understood that after the second device receives the first discovery request message sent by the first device or the second discovery request message sent by the other second device, the second device can feed back the first discovery response message.

[0320] In a possible implementation, as shown in FIG. 10A, if the second device is close to the network device and can be directly connected with the network device, the second device can send the first discovery response message (i.e., the first discovery message) according to the network information sent by the network device.

[0321] In another possible implementation, if the second device is far away from the network device and cannot be directly connected with the network device, the second device can send the second discovery request message based on the first discovery request message sent by the first device / the second discovery request message sent by the other second device, to find other relay devices. As shown in FIG. 10B, the embodiments of the present application can further include the following steps:

[0322] S501, the second device sends the second discovery request message, and correspondingly, the third device can receive the second discovery request message.

[0323] The second discovery request message can include one or more of the following:

[0324] The channel quality between the second device and the first device;

[0325] The channel quality between the second device and the other second device;

[0326] QoS requirement information between the second device and the network device;

[0327] QoS requirement information supported by the link between the second device and the first device;

[0328] QoS requirement information supported by the link between the second device and the other second device;

[0329] Remaining hop count.

[0330] It should be understood that if the second device is close to the first device, the second device can receive the first discovery request message sent by the first device, and the second device can measure the channel quality of the link between the second device and the first device according to the first discovery request message sent by the first device to obtain the channel quality between the two.

[0331] If the second device is far away from the first device and cannot receive the first discovery request message sent by the first device, but can receive the second discovery request message sent by the other second device, at this time, the second device can measure the channel quality of the link between the second device and the other second device according to the second discovery request message sent by the other second device to obtain the channel quality between the two.

[0332] It should be understood that the second discovery request message can carry QoS requirement information for the remaining link, i.e., QoS requirement information between the second device and the network device.

[0333] In some embodiments, the QoS information can include one or more of the following:

[0334] Latency information (including one or more of average latency, maximum latency, minimum latency);

[0335] Traffic information (including one or more of average traffic, maximum traffic, minimum traffic);

[0336] Error probability information;

[0337] QoS level (e.g., dividing latency information, traffic information, and error probability information into N levels).

[0338] It should be noted that the QoS requirement information between the second device and the network device is based on end-to-end QoS requirement information and QoS supported by the link between the second device and the first device; wherein the E2E QoS requirement information can be carried by the first discovery request information sent by the first device.

[0339] That is, the QoS requirement information of the remaining link can be determined based on the supported / consumed QoS information of the previous hop link. For example, the Packet Delay Budget (PDB) of the remaining link can be the E2E QoS requirement information minus the supported / consumed PDB of the link between the first device and the second device.

[0340] It should be understood that the supported QoS requirement information of the previous hop link can also be carried in the second discovery request message. For example, if the second device is close to the first device, the second device can receive the first discovery request message sent by the first device, and the supported QoS requirement information of the link between the first device and the second device can be carried in the second discovery request message. If the second device is far away from the first device, the second device can receive the second discovery request message sent by another second device, and the supported QoS requirement information of the link between the second device and the other second device can be carried in the second discovery request message sent by the current second device.

[0341] It should also be understood that the remaining hop count can be determined based on the maximum hop count and the hop count between the first device and the second device. For example, the second device can receive the first discovery request message sent by the first device, and the remaining hop count can be the maximum hop count carried in the first discovery request minus 1. The second device receives the second discovery request message sent by another second device, and the remaining hop count can be the remaining hop count in the second discovery request message minus 1.

[0342] In some embodiments, in order to guarantee the communication quality of relay transmission, the second device can also determine whether to send the first discovery request message before sending the first discovery request message. It should be understood that the second device sends the second discovery request message in S501 can be realized by the following steps:

[0343] The second device sends the second discovery request message when one or more of the following conditions are met:

[0344] The channel quality between the second device and the first device is better than a fifth threshold value;

[0345] The channel quality between the second device and the other second device is better than a sixth threshold value;

[0346] The channel quality between the second device and the target third device is better than a seventh threshold value; the target third device is a parent device that establishes a relay connection with the second device;

[0347] The supported QoS of the link between the second device and the first device meets the QoS requirement information of the second device;

[0348] The supported QoS of the link between the second device and the other second device meets the QoS requirement information of the second device;

[0349] The number of hops of the path of the relay connection established between the second device and the network device is less than the maximum number of hops.

[0350] It should be understood that if the second device is close to the first device, the second device can receive the first discovery request message sent by the first device, and the second device can measure one or more of the first discovery request message, the sidelink reference signal, the sidelink data channel, and the sidelink control channel sent by the first device to determine the channel quality between the second device and the first device. The second device can send the second discovery request message when the channel quality between the second device and the first device is good (better than the fifth threshold value).

[0351] If the second device is far away from the first device, the second device can receive the second discovery request message sent by the other second device, and the second device can measure one or more of the second discovery request message, the sidelink reference signal, the sidelink data channel, and the sidelink control channel sent by the other second device to determine the channel quality between the second device and the other second device. The second device can send the second discovery request message when the channel quality between the second device and the other second device is good (better than the sixth threshold value).

[0352] It should be understood that when the second device has established a relay connection with the network device, the second device can also measure the link between the second device and the parent device (which can be the target third device described above), for example, measure one or more of the sidelink reference signal, the sidelink data channel, and the sidelink control channel sent by the target third device to obtain the channel quality between the second device and the parent device. The second device can send the second discovery request message when the channel quality between the second device and the parent device is good (better than the seventh threshold value).

[0353] In an embodiment, the fifth threshold value, the sixth threshold value, and the seventh threshold value described above can be predefined or configured by the network device. That is, the fifth threshold value, the sixth threshold value, and the seventh threshold value can be determined according to predefined information or network device configuration information (for example, directly receiving configuration information sent by the network device, or based on historical configuration information of the network, or forwarding the configuration information of the network through the relay).

[0354] It should be noted that the fifth threshold value, the sixth threshold value, and the seventh threshold value can reuse the threshold value of the relay in the single-hop scenario. The fifth threshold value, the sixth threshold value, and the seventh threshold value can also be introduced threshold values dedicated to the multi-hop scenario. For example, for the multi-hop scenario, since the number of hops is more and it is more likely to occur link failure compared to single-hop, better channel quality is needed to ensure relay communication quality, so the fifth threshold value, the sixth threshold value, and the seventh threshold value can be greater than the threshold value of the relay in the single-hop scenario. In this way, the multi-hop relay scenario can be more flexible and adaptive.

[0355] In another implementation, the fifth threshold value, the sixth threshold value, and the seventh threshold value can be determined according to the first discovery request message sent by the first device; wherein the first discovery request message includes a second threshold value corresponding to each hop link; correspondingly, the fifth threshold value, the sixth threshold value, and the seventh threshold value can be determined based on the number of hops and the second threshold value corresponding to the associated link.

[0356] It should also be understood that if the second device is close to the first device, the second device can receive the first discovery request message sent by the first device, and the second device can determine whether the QoS supported by the link between the second device and the first device meets the QoS requirement information of the second device. The second device can send the second discovery request message when the QoS supported by the link between the second device and the first device meets the QoS requirement information of the second device.

[0357] If the second device is far away from the first device, the second device can receive the second discovery request message sent by other second devices, and the second device can determine whether the QoS supported by the link between the second device and the other second devices meets the QoS requirement information of the second device. The second device can send the second discovery request message when the QoS supported by the link between the second device and the other second devices meets the QoS requirement information of the second device.

[0358] It should be noted that the QoS requirement information of the second device is determined based on one or more of the following:

[0359] Implementation of the second device;

[0360] Configuration information of the network device;

[0361] Configuration information of the device (root relay UE) directly connected to the network device in the path in which the second device and the network device have established a relay connection.

[0362] The number of hops of the path in which the second device and the network device have established a relay connection is less than the maximum number of hops.

[0363] It should be understood that if the second device has established a relay connection to the network device, the second device can also determine whether the number of hops of the path of the established relay connection is less than the requirement of the maximum number of hops. The second device can send the first discovery message when the number of hops of the established relay connection is less than the limit of the maximum number of hops.

[0364] It should be noted that in the case where the second device has not established a relay connection with the network device, the second device can send the second discovery request message in a broadcast manner.

[0365] In the case where the second device has established a relay connection with the network device, the second device can send the second discovery request message to the target third device in a unicast manner; wherein the target third device is a parent device that has established a relay connection with the second device.

[0366] It should be understood that the second discovery message in the embodiments of the present application can include the related information of each of the one or more second paths supported by the third device. The third device can inform the second device of the related information of the one or more second paths supported by the third device through the second discovery message, so that the second device receiving the second discovery message can determine whether the third device can be selected as a relay UE according to the second discovery message.

[0367] It should be noted that the manner of determining the related information of the second path can be different for different third devices.

[0368] In some embodiments, referring to FIG. 8B, if the third device is close to the network device and can be directly connected to the network device, that is, the second path supported by the third device can be a Uu link between the third device and the network device, the third device can obtain the related information of the second path (i.e., the Uu link between the third device and the network device) according to the network information sent by the network device.

[0369] Exemplarily, the network information can include the related information of the network device, wherein the related information of the network device can include one or more of the following: cell identification information, the maximum number of hops supported by the network device, whether to support idle state or inactive state devices to provide relay services.

[0370] Exemplarily, the network information can also include resource configuration information of a downlink reference signal (or a downlink data channel, a downlink control channel), so that the second device can measure the corresponding channel quality on the Uu link between the second device and the network device according to the related configuration information of the downlink reference signal (or the downlink data channel, the downlink control channel) on the resource of the downlink reference signal (or the downlink data channel, the downlink control channel).

[0371] Exemplarily, the network information can further comprise relay and / or path selection related configuration information, such as the first threshold value, the second threshold value, the maximum hop count, the first condition, the second condition, the third condition, etc., and the embodiments of the present application do not limit this.

[0372] Of course, the third device can also be a device that cannot be directly connected with the network device, and in this scenario, the third device can receive the second discovery message sent by another third device, and determine the information related to one or more second paths supported by the third device based on the second discovery message.

[0373] It should be noted that the third device determines the information related to one or more second paths supported by the third device based on the second discovery message sent by another third device, which is the same as the manner in which the second device determines the information related to one or more second paths supported by the second device based on the second discovery message sent by the third device, and can be understood with reference to the related description above. For brevity, details are not repeated here.

[0374] In an embodiment of the present application, in order to guarantee the communication quality of relay transmission, in the scenario shown in FIG. 8B (the third device is the device closest to the network), the third device can further determine whether to send the second discovery message before sending the second discovery message. The third device can send the second discovery message in the following case:

[0375] The channel quality between the third device and the network device is better than an eighth threshold value;

[0376] The QoS information supported by the link between the third device and the network device meets the remaining QoS requirement;

[0377] The QoS information supported by the link between the third device and the network device and the QoS information supported by the link between the third device and the first device meet the end-to-end QoS requirement information.

[0378] It should be understood that the third device can measure one or more of the downlink reference signal, the downlink data channel, and the downlink control channel sent by the network device to determine the channel quality between the third device and the network device. The third device can send the second discovery message when the channel quality between the third device and the network device is good (better than the eighth threshold value).

[0379] In an embodiment, the eighth threshold value can be predefined or configured by the network device. That is, the eighth threshold value can be determined according to predefined information or network device configuration information.

[0380] It should be noted that the eighth threshold value can reuse the threshold value of the relay in the single-hop scenario. The eighth threshold value can also be a threshold value introduced specifically for the multi-hop scenario. For example, for the multi-hop scenario, since the number of hops is larger, it is more likely to occur link failure compared to single-hop, and better channel quality is required to ensure relay communication quality, so the eighth threshold value can be greater than the threshold value of the relay in the single-hop scenario. In this way, the multi-hop relay scenario can be more flexibly adapted.

[0381] In another implementation, the eighth threshold value can be determined according to a second discovery request message sent by the second device; wherein the second discovery request message can include a second threshold value corresponding to each hop link; correspondingly, the eighth threshold value is determined based on the number of hops corresponding to the link between the third device and the network device and the second threshold value.

[0382] It should be understood that the remaining QoS requirement can be determined based on the E2E QoS requirement information and the QoS information supported by the link between the third device and the first device.

[0383] In a possible implementation, the third device can determine whether to send the second discovery message based on whether the final remaining Uu QoS requirement information can be supported.

[0384] In a possible implementation, the third device can also determine whether to send the second discovery message based on whether the QoS supported by the link that has passed and the Uu link can support the E2E QoS requirement.

[0385] Through the communication method provided by the embodiments of the present application, the problems caused by the multi-path (mesh) network relay topology in the multi-hop scenario can be solved. For example, in the case where the network allows this topology (i.e., the network allows the same device to be connected to different parent devices), it is necessary to make enhancements in the discovery and selection mechanism; and in the case where the network does not allow this topology (i.e., the network does not allow the same device to be connected to different parent devices), it is necessary to avoid the occurrence of this topology scenario in the discovery and relay selection mechanism. The method provided by the embodiments of the present application can carry the relevant information of each link in the path supported by the device in the discovery message, so as to perform relay selection and / or path selection. The method provided by the embodiments of the present application also regulates the sending manner of the discovery message, and further regulates the condition for the relay device to determine whether to forward the discovery message.

[0386] The method provided by the embodiments of the present application will be described in detail in combination with specific application scenarios.

[0387] Embodiment one

[0388] It should be noted that embodiment one can be applied to a multi-path topology, and it can be understood that the system allows the same device to be connected to different parent relays.

[0389] Embodiment one is a mode A discovery process. Referring to the discovery process diagram shown in FIG. 11, the method provided by embodiment one can include the following steps:

[0390] Step 0: The Relay 3 closest to the network (with a direct link to the network) can receive network information sent by the gNB, such as network configuration information, network identification information, reference signal information, etc.

[0391] Step 1a: Relay 3 sends a discovery announcement message according to the upper layer (Prose layer) indication / configuration.

[0392] It should be noted that the network can configure a threshold value for judging link quality, which can include threshold information corresponding to the measurement indicators SINR / RSRP / RSRQ of the network reference signal.

[0393] It should also be noted that this threshold configuration can reuse the threshold configuration in the current single-hop relay, or introduce a new threshold configuration specifically for multi-hop relay (such as requiring better signal strength).

[0394] It should be understood that Relay 3 can measure the downlink reference signal, and if the SINR / RSRP / RSRQ of the downlink reference signal meets the configured threshold value, it sends the model A discovery announcement message.

[0395] It should also be understood that Relay 3 performs conditional judgment (also known as filtering) on whether to send the discovery announcement message, and by introducing a new threshold configuration, it can be more flexible to adapt to the scenario of multi-hop relay. For example, due to the larger number of hops, link failure is more likely to occur compared to single-hop, and better link quality is required to support multi-hop relay.

[0396] Step 1: Relay 3 determines that it can send a model A discovery announcement message, which can carry information related to the path between relay 3 and gNB, including the following (in addition to the information currently available in single-hop):

[0397] a) Uu link quality, and / or parameters that can express link quality information, such as measurement result levels (dividing the measurement result into N levels).

[0398] Wherein, Relay3 can measure DL reference signal, data transmission, control channel from network, and get the measurement value corresponding to L1 / L3 measurement index (RSRP / RSRQ / SINR).

[0399] b) QoS information that can be supported on Uu link.

[0400] The QoS information can include one or more of the following:

[0401] Latency information (average latency / maximum latency / minimum latency);

[0402] Traffic information (maximum traffic, minimum traffic, average traffic);

[0403] Error probability information, etc.

[0404] QoS level.

[0405] It should be noted that the QoS information that can be supported on the Uu link can be configured by the network (configured through dedicated RRC information or SIB information) or measured / estimated by the UE based on implementation.

[0406] c) Cell-related configuration information, such as maximum hop number that can be supported and / or whether IDLE / INACTIVE relay UE is supported, etc.

[0407] d) RRC state of the relay UE;

[0408] e) UE ID information (L2 ID, User Info, IP address, etc.).

[0409] The above information can be carried in the RRC container in the discovery announcement message.

[0410] It should be understood that the relevant information on the Uu hop that the remote UE cannot directly observe can be carried in the discovery announcement message, so that the remote UE can better select a suitable path when receiving the information.

[0411] Step 2a / 3a: Intermediate UEs (Relay2 and Relay1) determine whether to send model A discovery announcement message.

[0412] It should be noted that the network can configure a threshold value for judging the quality of the PC5 link, which can include threshold information corresponding to the measurement indicators SINR / RSRP / RSRQ of SL discovery / PSCCH / PSSCH.

[0413] It should also be noted that the threshold configuration can reuse the threshold configuration in the current single-hop relay, or introduce a new threshold configuration specifically for multi-hop relay (e.g., requiring better signal strength).

[0414] It should be understood that the intermediate UE (Relay2 and Relay1) can measure the SL reference signal / SL discovery / PSCCH / PSSCH, and when the SINR / RSRP / RSRQ of the SL reference signal / SL discovery / PSCCH / PSSCH meets the configured threshold value, the model A discovery announcement message is sent.

[0415] It should be noted that the intermediate UE (Relay2 and Relay1) receiving multiple qualified Model A discovery announcement messages can send multiple messages.

[0416] It should be understood that Relay2 and Relay1 make conditional judgments (also known as filtering) on whether to send a discovery announcement message, and by introducing a new threshold configuration, the multi-hop relay scenario can be more flexible. For example, due to the larger number of hops, link failure is more likely to occur than single-hop, and better link quality is required to support multi-hop relay.

[0417] Step 2 / 3: The intermediate UE (Relay2 and Relay1) judges that the model A discovery announcement message can be sent. In this information, the relevant information of the link between relay3-gNB and the relevant information of the link between relay2-relay3 is carried, wherein the relevant information of the link between relay2-relay3 can include the following contents: (The following information is in the model A discovery announcement message sent by the intermediate UE, in addition to the information currently available in single-hop and the information already sent by the parent relay)

[0418] a) Channel quality of the link with the parent relay and / or parameters that can express link quality information, such as measurement result levels (dividing the measurement result into N levels).

[0419] The channel quality can be the measurement of L1 / L3 measurement value (RSRP / RSRQ / SINR) of the intermediate UE (Relay2 and Relay1) to the SL reference signal / PSSCH / PSCCH / discovery message from the parent relay.

[0420] b) QoS information that can be supported on the link with the parent relay.

[0421] The QoS information can include one or more of the following:

[0422] Latency information (average latency / maximum latency / minimum latency);

[0423] Traffic information (maximum traffic, minimum traffic, average traffic);

[0424] Error probability information, etc.

[0425] QoS level.

[0426] It should be noted that the QoS information that can be supported on the link with the parent relay can be configured by the network, for example, through dedicated RRC information or SIB. The configuration granularity can be per-resource pool and / or per-CBR level.

[0427] The QoS information that can be supported on the link with the parent relay can also be measured / estimated by the intermediate UE based on the implementation.

[0428] c) RRC state of the current relay UE;

[0429] d) UE ID information (L2 ID, User Info, IP address, etc.)

[0430] It should be noted that the above information can be carried in the RRC container in the discovery message.

[0431] It should be noted that the above information can be carried in the RRC container in the discovery message.

[0432] It should be understood that other related information on the PC5 hop that the remote UE cannot directly observe can be carried in the discovery announcement message, so that the remote UE can better select a suitable path when receiving the information.

[0433] Step 4: remote UE monitors discovery announcement message according to ProSe layer configuration, after receiving discovery announcement message, relay / path selection is performed according to the following conditions:

[0434] a) whether the link quality between the remote relay (direct connection) is greater than the configured threshold value; it should be noted that the threshold value is configured by the network and / or predefined; the threshold value can reuse the threshold configuration in the current single-hop relay, or introduce a new threshold configuration dedicated to multi-hop relay (if better signal strength is required).

[0435] b) QoS information carried in the discovery announcement message, select the one that meets the QoS requirement or the one that can support the best QoS;

[0436] c) hop number information carried in the discovery announcement message, select the one that meets the maximum hop limit and the shortest;

[0437] d) whether all link qualities carried in the discovery announcement message are greater than the configured threshold, which can be configured by the network and / or predefined. It should be noted that all PC5s are the same, Uu is the same or each hop has its own configuration;

[0438] e) relay RRC state information carried in the discovery announcement message (such as selecting only paths with all connected states);

[0439] f) UE ID information carried in the discovery announcement message;

[0440] g) network information carried in the discovery announcement message (such as selecting only paths that support IDLE / INACTIVE relay).

[0441] Embodiment two

[0442] It should be noted that embodiment one can be applied to a multi-path topology. It can be understood that the system allows the same device to be connected to different parent nodes.

[0443] Embodiment two is a mode B discovery process. Referring to the discovery process diagram shown in FIG. 12, the method provided by embodiment two can include the following steps:

[0444] Step 1: Remote UE sends discovery solicitation message according to upper layer (Prose layer) configuration, which carries requirement information for the whole relay link. The requirement information for the whole relay link can include:

[0445] a) E2E QoS information, such as latency information (may be average latency / maximum latency / minimum latency) and / or traffic information (maximum, minimum, average), error probability information, etc., or QoS level; the QoS requirement information is configured by the Prose layer, or determined by the UE based on implementation, or obtained according to the QoS of the data triggering the relay service;

[0446] b) Maximum hop information, which is related to the service or related to the RSC;

[0447] c) Link quality threshold information of each link, which is related to the service or related to the RSC;

[0448] It should be understood that the Remote UE sends the discovery solicitation message to carry additional information, and finds a more suitable path by carrying the requirement information of the remote UE for the target relay link.

[0449] Step 2a / 3a: Intermediate UE (Relay2 and Relay1) determines whether to send a discovery solicitation message.

[0450] It should be understood that the intermediate UE (Relay2 and Relay1) can send the model B discovery solicitation message according to the network configuration (for example, the parent relay UE forwards the configuration from the network, or the network sends the configuration through the RRC message) and / or the pre-configuration and the measurement result of the link between the parent relay on the sidelink according to the upper layer (Prose layer) indication / configuration.

[0451] In an implementation mode, the intermediate UE (Relay2 and Relay1) determines whether to send the model B discovery solicitation message according to the signal quality.

[0452] Network configuration and / or pre-configuration and / or sidelink quality threshold information carried in discovery solicitation message by remote UE, such as SINR / RSRP / RSRQ threshold information measured from discovery solicitation message or data channel (PSCCH / PSSCH) from child relay, the threshold configuration can reuse the threshold configuration in current one-hop UE-to-UE relay, or introduce new threshold configuration dedicated for multi-hop UE-to-network relay;

[0453] Intermediate UE (Relay2 and Relay1) measure SL discovery or PSCCH / PSSCH, and send model B discovery solicitation information if the reference signal meets the threshold configuration;

[0454] In another implementation, intermediate UE (Relay2 and Relay1) judge whether to send according to the QoS that can be supported.

[0455] Wherein, intermediate UE (Relay2 and Relay1) can judge whether to forward the discovery solicitation message based on the implementation or network configuration to judge whether the QoS requirement information can be supported.

[0456] It should be noted that the relay UE sends the discovery solicitation message in a broadcast manner.

[0457] It should be understood that intermediate UE (Relay2 and Relay1) can make conditional judgment (filtering) on whether to forward the discovery solicitation, and by introducing the channel quality judgment of relay UE, the relay UE can only forward the signal with good quality and meeting the requirements when deciding to forward the discovery solicitation.

[0458] Step 2 / 3: The relay UE sends the discovery solicitation message according to the upper layer (Prose layer) configuration. It can include the current relay-to-gNB requirement, which includes the following contents:

[0459] a) UE ID information, such as L2 ID, User Info, IP address, etc.

[0460] b) link quality, and / or parameters that can express link quality information, such as measurement result level (dividing the measurement result into N levels).

[0461] The link quality is specifically the link quality information between the Relay UE and the child relay / remote, which can be the measurement value of L1 / L3 measurement value (RSRP / RSRQ / SINR) of SL reference signal, data transmission (PSSCH), control channel (PSCCH), discovery message from the child relay / remote.

[0462] c) QoS information.

[0463] In an implementation, the QoS information is the QoS requirement information for the remaining relay link, i.e. the QoS information (one or more of latency information, traffic information, error probability information, QoS class) from this relay to the network.

[0464] It should be understood that the QoS information from this relay to the network can be derived based on the previous hop, for example, the current PDB is the PDB of the previous hop of this relay (e.g. for relay1, the QoS information that can be supported / has been consumed on the remote UE to relay1 link).

[0465] In another implementation, the QoS information is the QoS information that can be supported by the previous hop (e.g. for relay1, the link from remote to relay1). Specifically, it can be the QoS information (e.g. latency information (average latency / max latency / min latency) and / or traffic information (max / min / average), error probability information, etc.) that can be supported on the link between the child relay, or it can be the QoS class. For this QoS information that can be supported,

[0466] The QoS information can be configured by the network (through dedicated RRC information or SIB, the configuration granularity can be per-resource pool and / or per-CBR class), or it can be measured / estimated by the UE based on the implementation.

[0467] d) Hop information. The remaining hop information is the hop information received minus one.

[0468] Step 4: The relay3 closest to the network (which has a direct link with the network) receives relevant information from the network, such as configuration information, network identification information, reference signal information, etc.

[0469] Step 5a: The relay 3 closest to the network (has direct link with the network) decides whether to send discovery respond message.

[0470] It should be understood that the relay 3 can send discovery respond information according to network configuration and channel measurement results and according to upper layer (Prose layer) indication / configuration.

[0471] a) The relay 3 decides according to signal quality.

[0472] Network configuration and / or link quality judgment threshold information in remote UE discovery, such as SINR / RSRP / RSRQ threshold information for measurement from network reference signals, the threshold configuration can reuse the threshold configuration in the current single-hop relay, or introduce new threshold configuration dedicated to multi-hop relay (such as requiring better signal strength);

[0473] The relay UE measures the DL reference signal, and if the reference signal meets the threshold configuration, it sends the model B discovery respond information;

[0474] b) The relay 3 decides according to the QoS that can be supported.

[0475] The relay UE judges whether to forward the discovery solicitation message based on the implementation or network configuration to judge whether it can support the final remaining Uu QoS requirement information; or

[0476] The relay UE judges whether to forward the discovery solicitation message according to the QoS that can be supported by the link that has been passed and the Uu link condition to support the E2E QoS requirement.

[0477] It should be understood that the relay UE can make conditional judgments (filtering) on whether discovery respond messages are needed, and by introducing new threshold configurations, it can be more flexible to adapt to the multi-hop relay scenario. For example, due to more hops, it is more likely to occur link failure compared to single-hop, and better link quality is required to support multi-hop relay.

[0478] Step 5: The relay 3 closest to the network (has direct link with the network) decides whether to send model B discovery respond message, which carries the following contents (in addition to the information currently available in single-hop):

[0479] a) Uu link quality information, and / or parameters that can express the link quality information, such as measurement result level (dividing the measurement result into N levels).

[0480] It should be noted that the relay 3 can measure the DL reference signal, data transmission, and control channel of the network to obtain the measurement value of the L1 / L3 measurement index (RSRP / RSRQ / SINR).

[0481] b) QoS information.

[0482] In a possible implementation, the QoS information can be the QoS information that can be supported on the Uu, such as delay information (which can be average delay / maximum delay / minimum delay) and / or traffic information (maximum, minimum, average), error probability information, etc., or QoS level; for the QoS information that can be supported,

[0483] The QoS information can be configured by the network (through dedicated RRC information or SIB information) or measured / estimated by the UE.

[0484] In another possible implementation, the QoS information can be the QoS information that can be supported on the link between the child relay and the parent relay, such as delay information (which can be average delay / maximum delay / minimum delay) and / or traffic information (maximum, minimum, average), error probability information, etc., or QoS level; for the QoS information that can be supported,

[0485] It should be noted that the QoS information can be configured by the network (through dedicated RRC information or SIB, and the configuration granularity can be per-resource pool and / or per-CBR level) or measured / estimated by the UE.

[0486] c) Cell-related configuration information, such as the maximum number of hops that can be supported and / or whether an IDLE / INACTIVE relay UE is supported;

[0487] d) RRC state of the relay UE;

[0488] e) UE ID information (L2 ID, User Info, IP address, etc.)

[0489] It should be noted that the above information can be carried in the RRC container in the discovery message.

[0490] It should be understood that by carrying the relevant information on the Uu hop that the remote UE cannot directly observe, it is convenient for the remote UE to better select the appropriate path when receiving the information.

[0491] Step 6a / 7a: Intermediate UE (Relay2 and Relay1) judges whether to send model B discovery respond message.

[0492] It should be understood that the intermediate UE (Relay2 and Relay1) can send the model B discovery respond message according to the network configuration and the channel measurement result and according to the upper layer (Prose layer) indication / configuration.

[0493] It should be noted that the network configuration and / or pre-configuration of the sidelink quality judgment threshold information, such as the SINR / RSRP / RSRQ threshold information for the discovery message / PSCCH / PSSCH measurement from the parent relay, the threshold configuration can reuse the threshold configuration in the current single-hop UE-to-UE relay, or introduce a new threshold configuration specially for the multi-hop UE-to-network relay.

[0494] The intermediate UE (Relay2 and Relay1) measures the SL reference signal / SL discovery / PSCCH / PSSCH, and sends the model B discovery respond information when the threshold configuration is met.

[0495] It should be noted that the intermediate UE (Relay2 and Relay1) can send the model B discovery respond message from multiple parent relay UEs.

[0496] It should be understood that the intermediate UE (Relay2 and Relay1) makes conditional judgments (filters) on whether to send the discovery respond. By introducing the channel quality judgment of the relay UE, the relay UE can only forward the signals with good quality when deciding whether to forward the discovery.

[0497] Step 6 / 7: The intermediate UE (Relay2 and Relay1) judges that the model B discovery respond information can be sent, which carries the following contents (in addition to the existing information of the single-hop and the information already sent by the parent relay):

[0498] a) link quality information between the relay UE and the parent relay, which can be the measurement value of L1 / L3 measurement value (RSRP / RSRQ / SINR) of SL reference signal, data transmission (PSSCH), control channel (PSCCH), discovery message from the parent relay, and / or a parameter capable of expressing link quality information, such as measurement result level (dividing the measurement result into N levels).

[0499] b) QoS information that can be supported on the link between the relay UE and the parent relay, such as delay information (which can be average delay / maximum delay / minimum delay) and / or traffic information (maximum, minimum, average), error probability information, etc., which can also be QoS level; for this QoS information that can be supported. The QoS information can be network configured (through dedicated RRC information or SIB, the configuration granularity can be per-resource pool and / or per-CBR level, etc.); or can be measured / estimated by the UE based on implementation.

[0500] c) RRC state of the relay UE.

[0501] It should be noted that the above information can be carried in the RRC container in the discovery message

[0502] It should be understood that the model B discovery respond message sent by the intermediate UE (Relay2 and Relay1) needs to carry additional information, which carries relevant information on other PC5 hops that the remote UE cannot directly observe, so as to facilitate the remote UE to better select a suitable path when receiving the information.

[0503] Step 8: The remote UE listens to the discovery message according to the Prose layer configuration, and selects the relay / path according to the following conditions after receiving the discovery message:

[0504] a) Whether the link quality between the remote relay (directly connected) is greater than the configured threshold value; it should be noted that the threshold value is network configured and / or predefined; the threshold value can reuse the threshold configuration in the current single-hop relay, or introduce a new threshold configuration specifically for multi-hop relay (such as requiring better signal strength).

[0505] b) QoS information carried in the discovery announcement message, select the one that meets the QoS requirement of itself or the one that can support the best QoS.

[0506] c) the hop number information carried in the discovery announcement message, select the shortest one that satisfies the maximum hop limit;

[0507] d) all link quality carried in the discovery announcement message, whether each link quality is greater than the configured threshold, which can be network configured and / or predefined. It should be noted that all PC5s are the same, Uu is the same or each hop has its own configuration;

[0508] e) relay RRC state information carried in the discovery announcement message (such as only selecting paths with all connected states);

[0509] f) UE ID information carried in the discovery announcement message;

[0510] g) network information carried in the discovery announcement message (such as only selecting paths supporting IDLE / INACTIVE relay).

[0511] Embodiment three

[0512] It should be noted that embodiment three can be applied to a single path topology. It can be understood that the system does not allow the same device to be connected to different parent nodes.

[0513] Embodiment three is a mode A discovery process. Referring to the discovery process diagram shown in FIG. 13, the method provided by embodiment three can include the following steps:

[0514] Step 0: The relay 3 closest to the network (with a direct link to the network) can receive network information sent by the gNB, such as network configuration information, network identification information, reference signal information, etc.

[0515] Step 1a: The relay 3 (with a direct link to the network and without selecting other parent relays) sends a discovery announcement message according to the upper layer (Prose layer) indication / configuration.

[0516] It should be noted that the network can configure a threshold value for judging the link quality, which can include threshold information corresponding to the measurement indicators SINR / RSRP / RSRQ of the network reference signal.

[0517] It should be noted that the threshold configuration can reuse the threshold configuration in the current single-hop relay, or introduce a new threshold configuration specifically for multi-hop relay (e.g. better signal strength is required).

[0518] It should be understood that Relay 3 can measure the downlink reference signal, and the SINR / RSRP / RSRQ of the downlink reference signal meets the configured threshold value, and then sends the model A discovery announcement message.

[0519] It should also be understood that Relay 3 makes conditional judgments (also known as filtering) on whether to send the discovery announcement message, and by introducing a new threshold configuration, it can be more flexible to adapt to the scenario of multi-hop relay. For example, due to more hops, it is more likely to occur link failure compared to single-hop, and better link quality is required to support multi-hop relay.

[0520] Step 1: Relay 3 (with direct link to the network and without selecting other parent relays) judges that it can send the model A discovery announcement message, which can carry the relevant information of the path between relay 3-gNB.

[0521] It should be noted that the relevant information of the path between relay 3-gNB is the same as in Embodiment One, and for the sake of brevity, it will not be repeated here.

[0522] Step 2a / 3a: Intermediate UEs (Relay 2 and Relay 1) can select parent relays if they have not selected parent relays.

[0523] It should be understood that the intermediate UEs (Relay 2 and Relay 1) then select parent relays according to network configuration (parent relay UE forwards configuration from network, or network sends configuration through RRC message) and / or pre-configuration and measurement results between parent relays on sidelink, and according to upper layer (Prose layer) indication / configuration.

[0524] It should be noted that the network configuration and / or pre-configuration sidelink quality judgment threshold information, such as SINR / RSRP / RSRQ threshold information measured from the discovery message or data channel (PSCCH / PSSCH) of the parent relay, can reuse the threshold configuration in the current single-hop UE-to-UE relay, or introduce a new threshold configuration specifically for multi-hop UE-to-network relay

[0525] In this way, the intermediate UE (Relay2 and Relay1) can measure SL reference signals / SL discovery / PSCCH / PSSCH, and if the measurement result meets the threshold configuration, the parent relay is considered as a candidate.

[0526] It should be noted that if there are multiple parent relays that meet the conditions, the UE selects the parent relay according to the following conditions:

[0527] a) Based on implementation;

[0528] b) Select the best link quality;

[0529] c) QoS information carried in the discovery, select the one that meets the QoS requirement or the one that can support the best QoS;

[0530] d) The number of hops carried in the discovery, select the one that meets the maximum hop limit and the shortest;

[0531] e) Relay RRC state information carried in the discovery (such as only selecting paths with all connected states);

[0532] f) Network information carried in the discovery (such as only selecting paths that support IDLE / INACTIVE relays).

[0533] It should be noted that the sending model A announcement message is in broadcast mode.

[0534] It should be understood that by introducing the channel quality of the relay UE, the relay UE decides to select the parent relay UE, and if it is selected, it is considered that the relay will only have a unique parent relay.

[0535] It should also be understood that the intermediate UE (Relay2 and Relay1) has selected the parent relay, and only forwards the model A announcement message from the parent relay. The sending model A announcement message is in broadcast mode.

[0536] By introducing the channel quality of the relay UE, the relay UE decides to select the parent relay UE, and if it is selected, it is considered that the relay will only have a unique parent relay.

[0537] Step 2 / 3: The intermediate UE (Relay2 and Relay1) judges that it can send the model A discovery announcement message. In this message, it carries the related information of the link between relay3-gNB and the related information of the link between relay2-relay3. It should be noted that the related information of the link between relay2-relay3 can refer to the description in Embodiment I above, and for the sake of brevity, will not be repeated here.

[0538] Step 4: The remote UE listens to the discovery announcement message according to the Prose layer configuration. After receiving the discovery announcement message, it selects the relay / path according to the following conditions:

[0539] Whether the link quality between the remote relay (directly connected) is greater than the configured threshold value; it should be noted that the threshold value is configured by the network and / or predefined; the threshold value can reuse the threshold configuration in the current single-hop relay, or introduce a new threshold configuration specifically for multi-hop relay (such as requiring better signal strength).

[0540] It should be noted that if there are multiple relay UEs that meet the conditions, the remote UE can further select according to the following conditions:

[0541] a) Based on implementation;

[0542] b) Select the best link quality;

[0543] c) QoS information carried in discovery, select the one that meets the QoS requirement of itself or can support the best QoS;

[0544] d) The number of hops carried in the discovery information, select the one that meets the maximum hop limit and is the shortest;

[0545] e) Relay RRC state information carried in discovery (such as only selecting paths with all connected states);

[0546] f) Network information carried in discovery (such as only selecting paths that support IDLE / INACTIVE relay).

[0547] It should be noted that since each hop of the relay UE has selected its parent relay, the remote UE only needs to select the relay UE, and the corresponding path is only one.

[0548] Embodiment Four

[0549] It should be noted that embodiment four can be applied to single-path topology. It can be understood that the system does not allow the same device to be connected to different parent nodes.

[0550] Embodiment four is a model B discovery procedure. Referring to the discovery procedure diagram shown in FIG. 14, the method provided by embodiment four can include the following steps:

[0551] Step 1: The remote UE sends a discovery solicitation message according to the upper layer (Prose layer) configuration, which carries the requirement information for the entire relay link. The requirement information for the entire relay link can refer to the description in embodiment two, and will not be repeated here for brevity.

[0552] Step 2a / 3a: The intermediate UE (Relay2 and Relay1) determines whether to send a discovery solicitation message.

[0553] It should be understood that the intermediate UE (Relay2 and Relay1) can send a model B discovery solicitation message according to the network configuration (for example, the parent relay UE forwards the configuration from the network, or the network sends the configuration through the RRC message) and / or the pre-configuration and the measurement result of the link between the parent relay on the sidelink and the indication / configuration of the upper layer (Prose layer).

[0554] In one implementation, the intermediate UE (Relay2 and Relay1) determines whether to send a model B discovery solicitation message according to the signal quality.

[0555] The network configuration and / or pre-configuration and / or the sidelink quality judgment threshold information carried in the discovery solicitation message by the remote UE, such as the SINR / RSRP / RSRQ threshold information measured from the discovery solicitation message or the data channel (PSCCH / PSSCH) of the child relay, the threshold configuration can reuse the threshold configuration in the current single-hop UE-to-UE relay, or introduce a new threshold configuration specially for multi-hop UE-to-network relay;

[0556] The intermediate UE (Relay2 and Relay1) measures SL discovery or PSCCH / PSSCH, and sends the model B discovery solicitation information if the reference signal meets the threshold configuration.

[0557] In another implementation, the intermediate UE (Relay2 and Relay1) determines whether to send according to the QoS that can be supported.

[0558] It should be noted that the Relay UE determines whether to forward the discovery solicitation message based on the implementation or network configuration or root relay UE configuration (a link to the root relay has been selected / established) to determine whether the QoS requirement information can be supported.

[0559] In yet another implementation, it can be determined whether to send according to hop information.

[0560] Specifically, for the Relay UE that has selected / established a link to the root relay, it is determined whether the maximum hop requirement matches the currently established link, i.e., the hop number of the currently established link is less than the maximum hop requirement.

[0561] It should be noted that if the relay UE has not selected a parent relay at this time, the model B discovery solicitation message is sent in a broadcast manner; if the relay UE has selected a parent relay at this time, the model B discovery solicitation information is sent in a unicast manner, and is only sent to the selected parent relay.

[0562] It should be understood that the intermediate UE (Relay2 and Relay1) can make conditional judgments (filtering) on whether the discovery solicitation needs to be forwarded, and by introducing the channel quality of the relay UE, the relay UE can only forward signals with good quality and that can meet the requirements when deciding to forward the discovery solicitation. In addition, the parent relay selection and unicast manner of discovery solicitation forwarding can achieve the purpose that one relay can only connect to one parent relay.

[0563] Step 2 / 3: Relay UE sends discovery solicitation message according to upper layer (Prose layer) configuration. It can include current relay to gNB requirement. The current relay to gNB requirement can refer to the related description in Embodiment Two, which will not be repeated here for brevity.

[0564] Step 4: The relay 3 closest to the network (with direct link to the network) receives relevant information from the network, such as configuration information, network identification information, reference signal information, etc.

[0565] Step 5a: The relay 3 closest to the network (with direct link to the network) determines whether to send a discovery response (discovery respond) message.

[0566] It should be understood that the relay 3 can send the discovery response information according to the network configuration and the channel measurement result and according to the upper layer (Prose layer) indication / configuration.

[0567] a) The relay 3 determines according to the signal quality.

[0568] The network configuration and / or the link quality judgment threshold information in remote UE discovery, such as SINR / RSRP / RSRQ threshold information for measurement of reference signals from the network, the threshold configuration can reuse the threshold configuration in the current single-hop relay, or introduce new threshold configuration dedicated to multi-hop relay (such as requiring better signal strength);

[0569] The relay UE measures the DL reference signal, and if the reference signal meets the threshold configuration, it sends the model B discovery respond information;

[0570] b) The relay 3 determines according to the supportable QoS.

[0571] The relay UE judges whether to forward the discovery solicitation message based on the implementation or network configuration to judge whether it can support the final remaining Uu QoS requirement information; or

[0572] The relay UE judges whether to forward the discovery solicitation message according to the implementation or network configuration to judge whether the QoS supported by the link already passed in combination with the Uu link case can support the E2E QoS requirement.

[0573] It should be understood that the relay UE can make conditional judgment (filtering) on whether the discovery respond message needs to be sent, and by introducing a new threshold configuration, the scenario of multi-hop relay can be more flexibly adapted, such as more link failures due to more hops, and better link quality is needed to support multi-hop relay.

[0574] Step 5: The relay 3 closest to the network (with a direct link to the network) judges that the model B discovery respond message can be sent, and the following contents are carried in the message (in addition to the information currently available for single-hop):

[0575] a) Uu link quality information, and / or parameters that can express link quality information, such as measurement result levels (dividing the measurement result into N levels).

[0576] It should be noted that the relay 3 can measure the DL reference signal, data transmission, and control channel of the network to obtain the measurement value of the L1 / L3 measurement index (RSRP / RSRQ / SINR);

[0577] b) QoS information.

[0578] In a possible implementation, the QoS information can be the QoS information that can be supported on the Uu, such as delay information (which can be average delay / maximum delay / minimum delay) and / or traffic information (maximum, minimum, average), error probability information, etc., or QoS level; for this QoS information that can be supported,

[0579] The QoS information can be configured by the network (through dedicated RRC information or SIB information), or measured / estimated by the UE.

[0580] In another possible implementation, the QoS information can be the QoS information that can be supported on the link between the child relay, such as delay information (which can be average delay / maximum delay / minimum delay) and / or traffic information (maximum, minimum, average), error probability information, etc., or QoS level; for this QoS information that can be supported,

[0581] It should be noted that the QoS information can be configured by the network (through dedicated RRC information or SIB, and the configuration granularity can be per-resource pool and / or per-CBR level), or measured / estimated by the UE.

[0582] c) Cell related configuration information, such as the maximum hop number that can be supported and / or whether IDLE / INACTIVE relay UE is supported, etc.

[0583] d) RRC state of the relay UE;

[0584] e) UE ID information (L2 ID, User Info, IP address, etc.)

[0585] It is noted that the above information can be carried in the RRC container in the discovery message.

[0586] It is understood that by carrying the related information on Uu hop that the remote UE cannot directly observe, it is easier for the remote UE to select a suitable path when it receives the information.

[0587] Step 6a / 7a: Intermediate UE (Relay2 and Relay1) selects parent relay.

[0588] It is understood that the network configures and / or pre-configures the sidelink quality judgment threshold information, such as the SINR / RSRP / RSRQ threshold information measured from the discovery message or data channel (PSCCH / PSSCH) of the parent relay, which threshold configuration can reuse the threshold configuration in the current single-hop UE-to-UE relay, or introduce a new threshold configuration specifically for the multi-hop UE-to-network relay

[0589] Wherein, the relay UE measures the SL discovery / PSCCH / PSSCH, and the reference signal satisfies the threshold configuration, then the parent relay is considered as a candidate;

[0590] It is noted that if there are multiple parent relays that meet the conditions, the UE selects the parent relay according to the following conditions:

[0591] a) Based on implementation;

[0592] b) Select the best link quality;

[0593] c) QoS information carried in the discovery, select the one that meets the QoS requirement of itself or can support the best QoS;

[0594] d) Hop number information carried in the discovery, select the one that meets the maximum hop number limit and is the shortest;

[0595] e) Relay RRC state information carried in discovery (e.g. only select paths with all connected state).

[0596] f) Network information carried in discovery (e.g. only select paths with IDLE / INACTIVE relay support).

[0597] It is noted that the sending of the model B respond message is in broadcast manner.

[0598] It is further noted that for the intermediate UEs (Relay2 and Relay1), if a parent relay has been selected, only forward the model B respond message from the parent relay, and the sending of the model A announcement message is in broadcast manner.

[0599] Step 6 / 7: The intermediate UEs (Relay2 and Relay1) determine that the model B discovery respond information can be sent, which carries the following information (in addition to the current single-hop information and the information already sent by the parent relay):

[0600] a) Link quality information between the UE and the parent relay, which can be the measurement value of the L1 / L3 measurement of the SL reference signal, data transmission (PSSCH), control channel (PSCCH), discovery message from the parent relay (RSRP / RSRQ / SINR), and / or a parameter that can express the link quality information, such as the measurement result level (dividing the measurement result into N levels).

[0601] b) The QoS information that can be supported on the link between the UE and the parent relay, such as the delay information (which can be the average delay, the maximum delay, and / or the minimum delay) and / or the traffic information (maximum, minimum, and / or average), the error probability information, etc., which can also be the QoS level; for the QoS information that can be supported. The QoS information can be configured by the network (through dedicated RRC information or SIB, and the configuration granularity can be per-resource pool and / or per-CBR level); or it can be measured / estimated by the UE based on the implementation.

[0602] c) The RRC state of the relay UE.

[0603] It is noted that the above information can be carried in the RRC container in the discovery message

[0604] It is understood that the model B discovery respond message sent by the intermediate UE (Relay2 and Relay1) needs to carry additional information, which carries relevant information on other PC5 hops that the remote UE cannot directly observe, to facilitate the remote UE to better select a suitable path when receiving the information.

[0605] Step 8: The remote UE listens to the discovery message according to the Prose layer configuration, and selects a relay according to the following conditions after receiving the discovery message:

[0606] a) Whether the link quality between the remote relay (directly connected) is greater than the configured threshold value; it is noted that the threshold value is network configured and / or predefined; the threshold value can reuse the threshold configuration in the current single-hop relay, or introduce a new threshold configuration specifically for multi-hop relay (if a better signal strength is required).

[0607] b) The QoS information carried in the discovery announcement message, select the one that meets the QoS requirement or the one that can support the best QoS;

[0608] c) The hop number information carried in the discovery announcement message, select the one that meets the maximum hop limit and the shortest;

[0609] d) All link qualities carried in the discovery announcement message, whether each link quality is greater than the configured threshold, which can be network configured and / or predefined. It is noted that all PC5s are the same, Uu is the same or each hop has its own configuration;

[0610] e) The relay RRC state information carried in the discovery announcement message (such as only selecting paths with all connected states);

[0611] f) The UE ID information carried in the discovery announcement message;

[0612] g) The network information carried in the discovery announcement message (such as only selecting paths that support IDLE / INACTIVE relay).

[0613] The preferred embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited to the specific details of the above-described embodiments. Various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and all of these simple modifications shall fall within the scope of protection of the present application. For example, in the above-described specific embodiments, various specific technical features described in the embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, various possible combinations are not described again in the present application. For another example, various different embodiments of the present application can also be combined in any appropriate manner, as long as it does not deviate from the idea of the present application, and it shall also be considered as disclosed in the present application. For another example, in the absence of conflict, various embodiments described in the present application and / or technical features in various embodiments can be combined with any prior art, and the technical solutions obtained after the combination shall also fall within the protection scope of the present application.

[0614] It should also be understood that, in various method embodiments of the present application, the magnitude of the serial number of the above-described processes does not mean the order of execution. The execution order of the processes should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. In addition, in the embodiments of the present application, the terms “downlink”, “uplink” and “sidelink” are used to represent the transmission direction of signals or data, wherein “downlink” is used to represent the first direction of the transmission direction of signals or data from the station to the user equipment of the cell, “uplink” is used to represent the second direction of the transmission direction of signals or data from the user equipment of the cell to the station, and “sidelink” is used to represent the third direction of the transmission direction of signals or data from the user equipment 1 to the user equipment 2. For example, “downlink signal” represents that the transmission direction of the signal is the first direction. In addition, in the embodiments of the present application, the term “and / or” is only used to describe the association relationship of the associated objects, which means that there can be three relationships. Specifically, A and / or B can represent three cases of A alone, A and B together, and B alone. In addition, the character “ / ” in this paper generally represents that the front and rear associated objects are in an “or” relationship.

[0615] FIG. 15 is a schematic structural diagram of a communication apparatus according to an embodiment of the present application, which is applied to a first device. As shown in FIG. 15, the communication apparatus comprises:

[0616] The first receiving unit 1510 is configured to receive a first discovery message sent by one or more second devices, wherein the first discovery message comprises relevant information of each first path supported by the second device; and the first path is a transmission path between the second device and a network device, and the first path comprises a single-hop link or a multi-hop link.

[0617] The first selection unit 1520 is configured to select a target relay device and / or a target path based on the first discovery message, the target relay device being one or more of the one or more second devices, and the target path being one or more of the first paths supported by the one or more second devices.

[0618] In some embodiments, the related information of the first path comprises one or more of the following:

[0619] Related information of a network device accessed;

[0620] Quality of service (QoS) information supported by the path;

[0621] Related information of each hop link in the path.

[0622] In some embodiments, the related information of each hop link in the path comprises one or more of the following:

[0623] Channel quality between two devices on the link;

[0624] Quality of service (QoS) information supported by the link;

[0625] RRC state of a sub-device in the link;

[0626] Identification information of a sub-device in the link.

[0627] In some embodiments, the related information of the network device comprises one or more of the following:

[0628] Cell identification information;

[0629] Maximum number of hops supported;

[0630] Whether to support a relay service provided by an idle state or inactive state device.

[0631] In some embodiments, the QoS information supported by the path, and / or the QoS information supported by the link, comprises one or more of the following:

[0632] Latency information;

[0633] Traffic information;

[0634] Error probability information;

[0635] QoS level.

[0636] In some embodiments, the first device supports connection with multiple parent devices, and / or the one or more second devices support connection with multiple parent devices; accordingly, the first selecting unit 1520 is further configured to select a target relay device and / or a target path based on the first discovery message, including one or more of the following:

[0637] the target relay device is a second device of the one or more second devices, and a channel quality between the first device and the second device is better than a first threshold value;

[0638] the target path is a path of the first paths, and QoS information supported by the path meets QoS requirement information of the first device;

[0639] the target path is a path of the first paths, and QoS information supported by the path is optimal; the QoS information supported by the first path is determined based on QoS information supported by each hop link in the first path;

[0640] a hop number of the target path is less than or equal to a maximum hop number;

[0641] the hop number of the target path is a minimum hop number of the first paths;

[0642] a link quality of each hop link of the target path is better than a second threshold value corresponding to the each hop link;

[0643] RRC states of devices in the target path meet a first condition;

[0644] identification information of the devices in the target path meets a second condition;

[0645] a network device accessed by the target path meets a third condition.

[0646] In some embodiments, the first device supports connection with one parent device, and the one or more second devices support connection with one parent device; accordingly, the first selecting unit 1520 is further configured to select a target relay device based on the first discovery message sent by the one or more second devices.

[0647] In some embodiments, the first selecting unit 1520 is further configured to select the target relay device based on one or more of the following:

[0648] the target relay device is a second device of the one or more second devices, and a channel quality between the first device and the second device is better than a first threshold value;

[0649] QoS information of a first path supported by the target relay device meets QoS requirement information of the first device;

[0650] The QoS information of the first path supported by the target relay device is optimal;

[0651] The number of hops of the first path supported by the target relay device is less than or equal to a maximum number of hops;

[0652] The number of hops of the first path supported by the target relay device is minimal;

[0653] The link quality of each hop link in the first path supported by the target relay device is better than a second threshold value corresponding to the each hop link;

[0654] The RRC state of each device in the first path supported by the target relay device satisfies a first condition;

[0655] The identification information of each device in the first path supported by the target relay device satisfies a second condition;

[0656] The network device accessed by the first path supported by the target relay device satisfies a third condition.

[0657] In some embodiments, the channel quality comprises one or more of the following:

[0658] A channel measurement result;

[0659] A channel measurement result level.

[0660] In some embodiments, the channel measurement result and / or the channel measurement result level is measured by a sub-device in a link from one or more of the following transmitted between two devices in the link:

[0661] A sidelink reference signal;

[0662] A sidelink data channel;

[0663] A sidelink control channel;

[0664] A second discovery message;

[0665] A downlink reference signal;

[0666] A downlink data channel;

[0667] A downlink control channel.

[0668] In some embodiments, the first discovery message is a first discovery announcement message, or the first discovery message is a first discovery response message.

[0669] In some embodiments, the first discovery message is a first discovery response message, and the communication apparatus further comprises a first sending unit configured to send a first discovery request message; the first discovery response message is associated with the first discovery request message.

[0670] In some embodiments, the first discovery request message comprises one or more of the following:

[0671] end-to-end QoS requirement information;

[0672] maximum hop count;

[0673] a second threshold value corresponding to each hop link.

[0674] In some embodiments, the end-to-end QoS requirement information comprises one or more of the following:

[0675] latency information between the first device and a network device;

[0676] traffic information between the first device and the network device;

[0677] error probability information between the first device and the network device;

[0678] QoS requirement level between the first device and the network device.

[0679] In some embodiments, the end-to-end QoS requirement information is determined based on one or more of the following:

[0680] configuration information of a proximity service, ProSe, layer in the first device;

[0681] implementation of the first device;

[0682] QoS information corresponding to data to be transmitted.

[0683] In some embodiments, the maximum hop count, and / or the second threshold value corresponding to each hop link, is related to a service corresponding to data to be transmitted.

[0684] In some embodiments, the first threshold value, and / or the second threshold value corresponding to each hop link, is determined according to predefined information or network configuration information.

[0685] In some embodiments, in each hop link of the first path, the second threshold value corresponding to a PC5 link is different from the second threshold value corresponding to a Uu link.

[0686] Or, in each hop link of the first path, the second threshold value corresponding to links of different hops is different.

[0687] In some embodiments, the first device is a remote device;

[0688] the second device is a device capable of providing a relay service.

[0689] Fig. 16 is a schematic diagram of a structure of a communication apparatus according to an embodiment of the present application, which is applied to a second device. As shown in Fig. 16, the communication apparatus comprises:

[0690] a second sending unit 1610 configured to send a first discovery message, wherein the first discovery message comprises relevant information of each of one or more first paths supported by the second device; the first path is a transmission path between the second device and a network device, and the first path comprises a single-hop link or a multi-hop link; and the first discovery message is used for selecting a target relay device and / or a target path.

[0691] In some embodiments, the communication apparatus further comprises a second receiving unit configured to receive a second discovery message sent by one or more third devices, wherein the second discovery message comprises relevant information of each of one or more second paths supported by the third device; the second path is a transmission path between the third device and the network device, and the second path comprises a single-hop link or a multi-hop link.

[0692] The one or more first paths supported by the second device are related to the one or more second paths supported by the third device.

[0693] In some embodiments, the second device supports connection with a plurality of parent devices, and / or the one or more third devices support connection with a plurality of parent devices.

[0694] The one or more first paths supported by the second device are composed of links between the second device and the one or more third devices, and the one or more second paths supported by the third device.

[0695] In some embodiments, the second device supports connection with one parent device, and the one or more third devices support connection with one parent device, and the second device supports one first path.

[0696] The first path supported by the second device is composed of a link between the second device and a target third device, and a second path supported by the target third device; the target third device is one of the one or more third devices.

[0697] In some embodiments, the second device has established a relay connection to the network device, and a parent device of the second device is the target third device; wherein,

[0698] The first discovery message sent by the second device is determined based on a second discovery message sent by the target third device in the second discovery message sent by the one or more third devices.

[0699] In some embodiments, the second device does not establish a relay connection with the network device, and the communication apparatus further comprises a second selection unit configured to select the target third device based on a second discovery message sent by the one or more third devices.

[0700] In some embodiments, the second selection unit is further configured to select the target third device based on one or more of the following:

[0701] the target third device is a third device of the one or more third devices, and a channel quality between the second device and the third device is better than a third threshold value;

[0702] QoS information corresponding to a second path supported by the target third device meets QoS requirement information of the second device;

[0703] QoS information corresponding to a second path supported by the target third device is optimal;

[0704] a hop count of a second path supported by the target third device is less than or equal to a maximum hop count;

[0705] a hop count of a second path supported by the target third device is minimal;

[0706] a link quality of each hop link in a second path supported by the target third device is better than a second threshold value corresponding to the each hop link;

[0707] an RRC state of each device in a second path supported by the target third device meets a first condition;

[0708] identification information of each device in a second path supported by the target third device meets a second condition;

[0709] a network device accessed by a second path supported by the target third device meets a third condition.

[0710] In some embodiments, the second sending unit 1610 is further configured to send the first discovery message when one or more of the following is met:

[0711] a channel quality between the second device and the one or more third devices is better than a fourth threshold value;

[0712] a hop count of a path between the second device and a network device via which a relay connection is established is less than a maximum hop count.

[0713] In some embodiments, the third threshold value and / or the fourth threshold value is determined based on one or more of the following:

[0714] network configuration information;

[0715] predefined information;

[0716] a first discovery request message sent by the first device; the first discovery request message comprises a second threshold value corresponding to each hop link, and the fourth threshold value is determined based on the hop number corresponding to the link between the second device and the one or more third devices and the second threshold value.

[0717] In some embodiments, the related information of the first path, and / or the related information of the second path comprises one or more of the following:

[0718] related information of a network device accessed;

[0719] QoS information supported by the path;

[0720] related information of each hop link in the path.

[0721] In some embodiments, the related information of each hop link in the path comprises one or more of the following:

[0722] channel quality between two devices on the link;

[0723] QoS information supported by the link;

[0724] RRC state of a child device in the link;

[0725] identification information of a child device in the link.

[0726] In some embodiments, the related information of the network device comprises one or more of the following:

[0727] cell identification information;

[0728] maximum hop number supported;

[0729] whether to support idle state or inactive state device providing relay service.

[0730] In some embodiments, the QoS information supported by the path, and / or the QoS information supported by the link comprises one or more of the following:

[0731] latency information;

[0732] traffic information;

[0733] error probability information;

[0734] QoS level.

[0735] In some embodiments, the first discovery message is a first discovery announcement message, and the second discovery message is a second discovery announcement message;

[0736] Alternatively, the first discovery message is a first discovery response message, and the second discovery message is a second discovery response message.

[0737] In some embodiments, the first discovery message is a first discovery response message, the second discovery message is a second discovery response message, and the second receiving unit is further configured to receive a first discovery request message sent by the first device, the first discovery response message being associated with the first discovery request message.

[0738] Alternatively, the second receiving unit is further configured to receive a second discovery request message sent by another second device.

[0739] In some embodiments, the second sending unit is further configured to send a second discovery request message, the second discovery request message sent by the second device being associated with the second discovery response message received by the second device.

[0740] In some embodiments, the first discovery request message comprises one or more of the following:

[0741] end-to-end QoS requirement information;

[0742] maximum hop count;

[0743] a second threshold value corresponding to each hop link.

[0744] In some embodiments, the end-to-end QoS requirement information comprises one or more of the following:

[0745] latency information between the first device and the network device;

[0746] traffic information between the first device and the network device;

[0747] error probability information between the first device and the network device;

[0748] QoS requirement level between the first device and the network device.

[0749] In some embodiments, the maximum hop count and / or the second threshold value corresponding to each hop link is related to a service corresponding to the data to be transmitted.

[0750] In some embodiments, the second threshold value corresponding to a PC5 link in the each hop link is different from the second threshold value corresponding to a Uu link.

[0751] Alternatively, the second threshold value corresponding to different links in the each hop link is different.

[0752] In some embodiments, the second discovery request message comprises one or more of the following:

[0753] Channel quality between the second device and the first device;

[0754] Channel quality between the second device and the other second devices;

[0755] The QoS requirement information between the second device and the network device; the QoS requirement information between the second device and the network device is based on the end-to-end QoS requirement information and the QoS determination supported by the link between the second device and the first device;

[0756] QoS requirements information supported by the link between the second device and the first device;

[0757] QoS requirement information supported by the link between the second device and the other second devices;

[0758] Remaining hops; the remaining hops are determined based on the maximum hops and the hops between the first device and the second device.

[0759] In some embodiments, the second sending unit is further configured to send the second discovery request message if one or more of the following conditions are met:

[0760] The channel quality between the second device and the first device is better than the fifth threshold.

[0761] The channel quality between the second device and the other second devices is better than the sixth threshold.

[0762] The channel quality between the second device and the target third device is better than the seventh threshold; the target third device is the parent device that establishes a relay connection with the second device;

[0763] The QoS supported by the link between the second device and the first device meets the QoS requirements of the second device.

[0764] The QoS supported by the link between the second device and the other second devices satisfies the QoS requirements of the second device.

[0765] The number of hops in the relay connection established between the second device and the network device is less than the maximum number of hops.

[0766] In some embodiments, the QoS requirement information of the second device is determined based on one or more of the following:

[0767] Implementation of the second device;

[0768] Network device configuration information;

[0769] Configuration information of a device directly connected with the network device in a path in which the second device has established a relay connection with the network device.

[0770] In some embodiments, in a case where the second device has not established a relay connection with a network device, the second device sends the second discovery request message in a broadcast manner;

[0771] In a case where the second device has established a relay connection with a network device, the second device sends the second discovery request message to a target third device in a unicast manner; the target third device is a parent device that has established a relay connection with the second device.

[0772] In some embodiments, the channel quality comprises one or more of the following:

[0773] Channel measurement result;

[0774] Channel measurement result level.

[0775] In some embodiments, the channel measurement result and / or channel measurement result level is measured by a child device in a link on one or more of the following transmitted between two devices in the link:

[0776] Sidelink reference signal;

[0777] Sidelink data channel;

[0778] Sidelink control channel;

[0779] Second discovery message;

[0780] Downlink reference signal;

[0781] Downlink data channel;

[0782] Downlink control channel.

[0783] In some embodiments, the first device is a remote device;

[0784] The second device and the one or more third devices are devices capable of providing relay services.

[0785] FIG. 17 is a structural composition diagram three of a communication apparatus provided by an embodiment of the present application, applied to a third device, as shown in FIG. 17, the communication apparatus comprises:

[0786] A third sending unit 1710, configured to send a second discovery message;

[0787] The second discovery message includes relevant information of each of one or more second paths supported by the third device, the second path being a transmission path between the third device and a network device, the second path including a single-hop or multi-hop link; the first discovery message is related to the second discovery message, and the first discovery message is used to select a target relay device and / or a target path.

[0788] In some embodiments, the relevant information of the second path includes one or more of the following:

[0789] relevant information of an accessed network device;

[0790] QoS information supported by the path;

[0791] relevant information of each hop link in the path.

[0792] In some embodiments, the relevant information of each hop link includes one or more of the following:

[0793] channel quality between two devices of the link;

[0794] QoS information supported by the link;

[0795] RRC state of a child device in the link;

[0796] identification information of a child device in the link.

[0797] In some embodiments, the relevant information of the network device includes one or more of the following:

[0798] cell identification information;

[0799] maximum number of hops supported;

[0800] whether to support a relay service provided by an idle state or inactive state device.

[0801] In some embodiments, the QoS information supported by the path, and / or the QoS information supported by the link, includes one or more of the following:

[0802] latency information;

[0803] traffic information;

[0804] error probability information;

[0805] QoS level.

[0806] In some embodiments, the third device is directly connected to the network device, and the third sending unit 1710 is further configured to send the second discovery message when one or more of the following conditions is met:

[0807] a channel quality between the third device and the network device is better than an eighth threshold value;

[0808] QoS information supported by a link between the third device and the network device satisfies a residual QoS requirement; the residual QoS requirement is determined based on the end-to-end QoS requirement information and QoS information supported by a link between the third device and the first device;

[0809] QoS information supported by a link between the third device and the network device and QoS information supported by a link between the third device and the first device satisfy the end-to-end QoS requirement information.

[0810] In some embodiments, the eighth threshold value is determined based on one or more of:

[0811] network configuration information;

[0812] predefined information;

[0813] a second discovery request message; the second discovery request message comprises a second threshold value corresponding to each hop link; the eighth threshold value is determined based on a hop number corresponding to a link between the three devices and the network device and the second threshold value.

[0814] In some embodiments, the second discovery message is a second discovery announcement message, or the second discovery message is a second discovery response message.

[0815] In some embodiments, the communication apparatus further comprises a third receiving unit configured to receive a second discovery request message, the second discovery response message being associated with the second discovery request message.

[0816] In some embodiments, the second discovery request message comprises one or more of:

[0817] a channel quality between the second device and the first device;

[0818] a channel quality between the second device and the other second device;

[0819] QoS requirement information between the second device and the network device; the QoS requirement information between the second device and the network device is determined based on the end-to-end QoS requirement information and QoS supported by a link between the second device and the first device;

[0820] QoS requirement information of a link between the second device and the first device;

[0821] QoS requirement information of a link between the second device and the other second device;

[0822] a remaining number of hops; the remaining number of hops is determined based on the maximum number of hops and a number of hops between the first device and the second device.

[0823] In some embodiments, the channel quality comprises one or more of:

[0824] a channel measurement result;

[0825] a channel measurement result level.

[0826] In some embodiments, the channel measurement result and / or the channel measurement result level is measured from one or more of the following transmitted between a pair of devices in a link:

[0827] a sidelink reference signal;

[0828] a sidelink data channel;

[0829] a sidelink control channel;

[0830] a second discovery message;

[0831] a downlink reference signal;

[0832] a downlink data channel;

[0833] a downlink control channel.

[0834] In some embodiments, the second device and the third device are devices capable of providing a relay service.

[0835] It should be understood by those skilled in the art that the above description of the communication apparatus of the embodiments of the present application can be understood with reference to the description of the communication method of the embodiments of the present application.

[0836] FIG. 18 is a schematic structural diagram of a communication device 1800 provided by an embodiment of the present application. The communication device can be a first device, a second device, or a third device. The communication device 1800 shown in FIG. 18 includes a processor 1810, which can call and run a computer program from a memory to implement the method in the embodiments of the present application.

[0837] Optionally, as shown in FIG. 18, the communication device 1800 can further include a memory 1820. The processor 1810 can call and run a computer program from the memory 1820 to implement the method in the embodiments of the present application.

[0838] The memory 1820 can be a separate device independent of the processor 1810, or can be integrated in the processor 1810.

[0839] Optionally, as shown in FIG. 18, the communication device 1800 can further include a transceiver 1830, which can be controlled by the processor 1810 to communicate with other devices, specifically, to send information or data to other devices, or to receive information or data sent by other devices.

[0840] The transceiver 1830 can include a transmitter and a receiver. The transceiver 1830 can further include an antenna, and the number of antennas can be one or more.

[0841] Optionally, the communication device 1800 can be specifically a first device of the embodiments of the present application, and the communication device 1800 can implement the corresponding procedures implemented by the first device in each of the methods of the embodiments of the present application. For the sake of brevity, details are not described herein.

[0842] Optionally, the communication device 1800 can be specifically a second device of the embodiments of the present application, and the communication device 1800 can implement the corresponding procedures implemented by the second device in each of the methods of the embodiments of the present application. For the sake of brevity, details are not described herein.

[0843] Optionally, the communication device 1800 can be specifically a third device of the embodiments of the present application, and the communication device 1800 can implement the corresponding procedures implemented by the third device in each of the methods of the embodiments of the present application. For the sake of brevity, details are not described herein.

[0844] FIG. 19 is a schematic structural diagram of a chip according to the embodiments of the present application. The chip 1900 shown in FIG. 19 includes a processor 1910, which can call and run a computer program from a memory to implement the method in the embodiments of the present application.

[0845] Optionally, as shown in FIG. 19, the chip 1900 can further include a memory 1920. The processor 1910 can call and run a computer program from the memory 1920 to implement the method in the embodiments of the present application.

[0846] The memory 1920 can be a separate device independent of the processor 1910, or can be integrated in the processor 1910.

[0847] Optionally, the chip 1900 can further include an input interface 1930. The processor 1910 can control the input interface 1930 to communicate with other devices or chips, specifically, to obtain information or data sent by other devices or chips.

[0848] Optionally, the chip 1900 can further include an output interface 1940. The processor 1910 can control the output interface 840 to communicate with other devices or chips, specifically, to output information or data to other devices or chips.

[0849] Optionally, the chip can be applied to the first device in the embodiments of the present application, and the chip can implement the corresponding procedures implemented by the first device in the various methods of the embodiments of the present application. For brevity, details are not described herein.

[0850] Optionally, the chip can be applied to the second device in the embodiments of the present application, and the chip can implement the corresponding procedures implemented by the second device in the various methods of the embodiments of the present application. For brevity, details are not described herein.

[0851] Optionally, the chip can be applied to the third device in the embodiments of the present application, and the chip can implement the corresponding procedures implemented by the third device in the various methods of the embodiments of the present application. For brevity, details are not described herein.

[0852] It should be understood that the chip mentioned in the embodiments of the present application can also be referred to as a system chip, a system chip, a chip system or a system on chip, etc.

[0853] The embodiments of the present application also provide a computer storage medium, which stores one or more programs, and the one or more programs can be executed by one or more processors to implement the method in the embodiments of the present application.

[0854] FIG. 20 is a schematic block diagram of a communication system 2000 provided by the embodiments of the present application. As shown in FIG. 20, the communication system 2000 includes a first device 2010, a second device 2020 and a third device 2030.

[0855] Among them, the first device 2010 can be used to implement the corresponding functions of the first device in the above method, and the second device 2020 can be used to implement the corresponding functions of the second device in the above method, and the third device 2030 can be used to implement the corresponding functions of the third device in the above method. For brevity, details are not described herein.

[0856] It should be understood that the processor of the embodiments of the present application can be an integrated circuit chip with a processing capability of signals. In the implementation process, each step of the method embodiments described above can be completed by the integrated logic circuit of hardware in the processor or the instructions in the form of software. The processor described above can be a general processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The disclosed methods, steps and logic block diagrams in the embodiments of the present application can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor or the like. The steps of the method disclosed in conjunction with the embodiments of the present application can be directly embodied as a hardware coding processor for execution, or a combination of hardware and software modules in the coding processor for execution. The software module can be located in a random access memory, a flash memory, a read only memory, a programmable read only memory or an electrically erasable programmable memory, a register or other mature storage medium in the art. The storage medium is located in the storage, and the processor reads the information in the storage, and combines the hardware to complete the steps of the above method.

[0857] It is to be understood that the memory in the embodiments of the present application can be a volatile memory or a nonvolatile memory, or can include both volatile and nonvolatile memory. Among them, the nonvolatile memory can be a read-only memory (Read-Only Memory, ROM), a programmable read-only memory (Programmable ROM, PROM), an erasable programmable read-only memory (Erasable PROM, EPROM), an electrically erasable programmable read-only memory (Electrically EPROM, EEPROM) or a flash memory. The volatile memory can be a random access memory (Random Access Memory, RAM) used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (Static RAM, SRAM), dynamic random access memory (Dynamic RAM, DRAM), synchronous dynamic random access memory (Synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (Double Data Rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (Enhanced SDRAM, ESDRAM), synchronous link dynamic random access memory (Synchlink DRAM, SLDRAM) and direct memory bus random access memory (Direct Rambus RAM, DR RAM). It should be noted that the memory of the system and method described herein is intended to include, but not limited to, these and any other suitable types of memory.

[0858] It should be understood that the above-mentioned memory is exemplary but not limiting, for example, the memory in the embodiments of the present application can also be static random access memory (static RAM, SRAM), dynamic random access memory (dynamic RAM, DRAM), synchronous dynamic random access memory (synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synchronous link dynamic random access memory (synch link DRAM, SLDRAM) and direct memory bus random access memory (Direct Rambus RAM, DR RAM) and the like. That is, the memory in the embodiments of the present application is intended to include, but not limited to, these and any other suitable types of memory.

[0859] The embodiment of the present application further provides a computer readable storage medium for storing the computer program.

[0860] Optionally, the computer readable storage medium can be applied to the network device in the embodiment of the present application, and the computer program makes the computer execute the corresponding process realized by the network device in the various methods of the embodiment of the present application, which will not be repeated here for the sake of brevity.

[0861] Optionally, the computer readable storage medium can be applied to the mobile terminal / terminal device in the embodiment of the present application, and the computer program makes the computer execute the corresponding process realized by the mobile terminal / terminal device in the various methods of the embodiment of the present application, which will not be repeated here for the sake of brevity.

[0862] The embodiment of the present application further provides a computer program product comprising computer program instructions.

[0863] Optionally, the computer program product can be applied to the network device in the embodiment of the present application, and the computer program instructions make the computer execute the corresponding process realized by the network device in the various methods of the embodiment of the present application, which will not be repeated here for the sake of brevity.

[0864] Optionally, the computer program product can be applied to the mobile terminal / terminal device in the embodiment of the present application, and the computer program instructions make the computer execute the corresponding process realized by the mobile terminal / terminal device in the various methods of the embodiment of the present application, which will not be repeated here for the sake of brevity.

[0865] The embodiment of the present application further provides a computer program.

[0866] Optionally, the computer program can be applied to the network device in the embodiment of the present application, and when the computer program runs on the computer, makes the computer execute the corresponding process realized by the network device in the various methods of the embodiment of the present application, which will not be repeated here for the sake of brevity.

[0867] Optionally, the computer program can be applied to the mobile terminal / terminal device in the embodiment of the present application, and when the computer program runs on the computer, makes the computer execute the corresponding process realized by the mobile terminal / terminal device in the various methods of the embodiment of the present application, which will not be repeated here for the sake of brevity.

[0868] Those skilled in the art can clearly understand that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0869] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

[0870] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the above-described device embodiments are merely schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0871] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on multiple network units. According to actual needs, part or all of the units can be selected to achieve the purpose of the embodiment.

[0872] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically independently, or two or more units can be integrated into one unit.

[0873] If the functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the parts of the technical solutions that essentially contribute to the prior art or the parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0874] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A communication method, the method comprising: A first device receives a first discovery message sent by one or more second devices. The first discovery message includes relevant information about each of one or more first paths supported by the second device. The first path is a transmission path between the second device and a network device, and the first path includes a single-hop link or a multi-hop link. Based on the first discovery message, the first device selects a target relay device and / or a target path, wherein the target relay device is one or more of the one or more second devices, and the target path is one or more of the first paths supported by the one or more second devices.

2. The method according to claim 1, wherein, The relevant information for the first path includes one or more of the following: Information about the network devices being accessed; QoS information supported by the path; Information related to each hop link in the path.

3. The method according to claim 2, wherein, The relevant information for each hop link in the path includes one or more of the following: Channel quality between two devices on the link; Quality of Service (QoS) information supported by the link; RRC status of sub-devices in the link; Identification information of sub-devices in the link.

4. The method according to claim 2 or 3, wherein, The relevant information of the network device includes one or more of the following: Community signage information; Maximum number of hops supported; Does it support relay services from idle or inactive devices? 5. The method according to any one of claims 2-4, wherein, The QoS information supported by the path, and / or the QoS information supported by the link, includes one or more of the following: Delay information; Traffic information; Error probability information; QoS level.

6. The method according to any one of claims 1-5, wherein, The first device supports connection to multiple parent devices, and / or the one or more second devices support connection to multiple parent devices; Based on the first discovery message, the first device selects a target relay device and / or a target path, including one or more of the following: The target relay device is one of the one or more second devices whose channel quality with the first device is better than a first threshold value; The target path is the path in the first path whose QoS information satisfies the QoS requirements of the first device. The target path is the path with the best QoS information supported in the first path; The number of hops in the target path is less than or equal to the maximum number of hops; The number of hops in the target path is the path with the fewest hops in the first path; The link quality of each hop of the target path is better than the second threshold value corresponding to each hop; The RRC status of each device in the target path meets the first condition; The identification information of each device in the target path satisfies the second condition; The network device accessed by the target path meets the third condition.

7. The method according to any one of claims 1-5, wherein, The first device supports connection to a parent device, and the one or more second devices support connection to a parent device; The first device selects a target relay device and / or a target path based on a first discovery message sent by one or more second devices, including: The first device selects a target relay device based on a first discovery message sent by one or more second devices.

8. The method according to claim 7, wherein, The first device selects the target relay device based on one or more of the following: The target relay device is one of the one or more second devices whose channel quality with the first device is better than a first threshold value; The QoS information of the first path supported by the target relay device meets the QoS requirements of the first device. The target relay device supports the best QoS information for the first path; The number of hops for the first path supported by the target relay device is less than or equal to the maximum number of hops; The target relay device supports the first path with the fewest hops; The link quality of each hop in the first path supported by the target relay device is better than the second threshold value corresponding to each hop; The RRC status of each device in the first path supported by the target relay device meets the first condition; The identification information of each device in the first path supported by the target relay device satisfies the second condition; The network devices accessed by the first path supported by the target relay device meet the third condition.

9. The method according to any one of claims 3-8, wherein, The channel quality includes one or more of the following: Channel measurement results; Channel measurement result level.

10. The method according to claim 9, wherein, The channel measurement results and / or channel measurement result levels are obtained by a sub-device in the link measuring one or more of the following information transmitted between two devices in the link: Lateral reference signal; Side-line data channel; Side-line control channel; Second discovery message; Downward reference signal; Downlink data channel; Downlink control channel.

11. The method according to any one of claims 1-10, wherein, The first discovery message is either a first discovery announcement message or a first discovery response message.

12. The method according to any one of claims 1-11, wherein, The first discovery message is a first discovery response message, which also includes: The first device sends a first discovery request message; the first discovery response message is associated with the first discovery request message.

13. The method according to claim 12, wherein, The first discovery request message includes one or more of the following: End-to-end QoS requirement information; Maximum number of hops; The second threshold value corresponding to each hop link.

14. The method according to claim 13, wherein, The end-to-end QoS requirement information includes one or more of the following: The latency information between the first device and the network device; Traffic information between the first device and the network device; Error probability information between the first device and the network device; The QoS requirement level between the first device and the network device.

15. The method according to claim 13 or 14, wherein, The end-to-end QoS requirement information is determined based on one or more of the following: Configuration information of the Prose layer of adjacent services in the first device; The first device implements this; QoS information corresponding to the data to be transmitted.

16. The method according to any one of claims 6, 8, 13-15, wherein, The maximum number of hops and / or the second threshold value corresponding to each hop link are related to the service corresponding to the data to be transmitted.

17. The method according to any one of claims 6-8 or 13-16, wherein, The first threshold value, and / or the second threshold value corresponding to each hop link, are determined based on predefined information or network configuration information.

18. The method according to any one of claims 6-8 or 13-17, wherein, In each hop of the first path, the second threshold value corresponding to the PC5 link is different from the second threshold value corresponding to the Uu link; Alternatively, in each hop of the first path, the second threshold value corresponding to different hops is different.

19. The method according to any one of claims 1-18, wherein, The first device is a remote device; The second device is a device capable of providing relay services.

20. A communication method, the method comprising: The second device sends a first discovery message, which includes relevant information about each of the one or more first paths supported by the second device. The first path is the transmission path between the second device and the network device, and the first path includes a single-hop link or a multi-hop link; the first discovery message is used to select a target relay device and / or a target path.

21. The method according to claim 20, wherein, The second device receives a second discovery message sent by one or more third devices. The second discovery message includes relevant information about each of the one or more second paths supported by the third device. The second path is a transmission path between the third device and the network device, and the second path includes single-hop or multi-hop links. One or more first paths supported by the second device are related to one or more second paths supported by the third device.

22. The method according to claim 21, wherein, The second device supports connection to multiple parent devices, and / or, the one or more third devices support connection to multiple parent devices. The first path supported by the second device consists of a link between the second device and the one or more third devices, and one or more second paths supported by the third device.

23. The method according to claim 21, wherein, The second device supports connection to a parent device, the one or more third devices support connection to a parent device, and the second device supports a first path; The first path supported by the second device consists of a link between the second device and the target third device, and a second path supported by the target third device; the target third device is one of the one or more third devices.

24. The method according to claim 23, wherein, The second device has established a relay connection to the network device, and the parent device of the second device is the target third device; wherein, The first discovery message sent by the second device is determined based on the second discovery messages sent by the target third device among the second discovery messages sent by the one or more third devices.

25. The method according to claim 23, wherein, The second device did not establish a relay connection with the network device, and the method further includes: The second device selects the target third device based on the second discovery message sent by the one or more third devices.

26. The method of claim 25, wherein, The second device selects the target third device based on one or more of the following: The target third device is one of the one or more third devices that has a channel quality with the second device that is better than a third threshold value; The QoS information corresponding to the second path supported by the target third device satisfies the QoS requirement information of the second device. The QoS information corresponding to the second path supported by the target third device is optimal; The number of hops for the second path supported by the target third device is less than or equal to the maximum number of hops; The target third device supports the second path with the fewest hops; The link quality of each hop in the second path supported by the target third device is better than the second threshold value corresponding to each hop; The RRC status of each device in the second path supported by the target third device satisfies the first condition; The identification information of each device in the second path supported by the target third device satisfies the second condition; The network devices accessed by the second path supported by the target third device meet the third condition.

27. The method according to any one of claims 21-26, wherein, The second device sends a first discovery message, including: The second device sends the first discovery message if one or more of the following conditions are met: The channel quality between the second device and the one or more third devices is better than the fourth threshold. The number of hops in the relay connection established between the second device and the network device is less than the maximum number of hops.

28. The method according to claim 26 or 27, wherein, The third and / or fourth threshold values ​​are determined based on one or more of the following: Network configuration information; Predefined information; The first device sends a first discovery request message; the first discovery request message includes a second threshold value corresponding to each hop link, and the fourth threshold value is determined based on the number of hops corresponding to the links between the second device and the one or more third devices and the second threshold value.

29. The method according to any one of claims 20-28, wherein, The relevant information for the first path, and / or the relevant information for the second path, includes one or more of the following: Information about the network devices being accessed; QoS information supported by the path; Information related to each hop link in the path.

30. The method according to claim 29, wherein, The relevant information for each hop link in the path includes one or more of the following: Channel quality between two devices on the link; QoS information supported by the link; RRC status of sub-devices in the link; Identification information of sub-devices in the link.

31. The method according to claim 29 or 30, wherein, The relevant information of the network device includes one or more of the following: Community signage information; Maximum number of hops supported; Does it support relay services from idle or inactive devices? 32. The method according to any one of claims 29-31, wherein, The QoS information supported by the path, and / or the QoS information supported by the link, includes one or more of the following: Delay information; Traffic information; Error probability information; QoS level.

33. The method according to any one of claims 22-32, wherein, The first discovery message is a first discovery announcement message, and the second discovery message is a second discovery announcement message; Alternatively, the first discovery message may be a first discovery response message, and the second discovery message may be a second discovery response message.

34. The method according to any one of claims 20-33, wherein, The first discovery message is a first discovery response message, the second discovery message is a second discovery response message, and the method further includes: The second device receives a first discovery request message sent by the first device, and the first discovery response message is associated with the first discovery request message; or, The second device receives a second discovery request message sent by another second device.

35. The method according to claim 34, wherein, Before the second device receives a second discovery response message sent by one or more third devices, it further includes: The second device sends a second discovery request message, which is associated with the second discovery response message received by the second device.

36. The method according to claim 34 or 35, wherein, The first discovery request message includes one or more of the following: End-to-end QoS requirement information; Maximum number of hops; The second threshold value corresponding to each hop link.

37. The method of claim 36, wherein, The end-to-end QoS requirement information includes one or more of the following: Latency information between the first device and the network device; Traffic information between the first device and the network device; Error probability information between the first device and the network device; The QoS requirement level between the first device and the network device.

38. The method according to claim 36 or 37, wherein, The maximum number of hops and / or the second threshold value corresponding to each hop link are related to the service corresponding to the data to be transmitted.

39. The method according to claim 26, and any one of claims 36-38, wherein, In each hop link, the second threshold value corresponding to the PC5 link is different from the second threshold value corresponding to the Uu link; Alternatively, in each hop link, the second threshold value corresponding to different hop links is different.

40. The method according to any one of claims 33-39, comprising: The second discovery request message includes one or more of the following: Channel quality between the second device and the first device; Channel quality between the second device and the other second devices; QoS requirement information between the second device and the network device; The QoS requirement information between the second device and the network device is based on the end-to-end QoS requirement information and the QoS determination supported by the link between the second device and the first device; QoS requirements information supported by the link between the second device and the first device; QoS requirement information supported by the link between the second device and the other second devices; Remaining hops; the remaining hops are determined based on the maximum hops and the hops between the first device and the second device.

41. The method according to any one of claims 35-40, wherein, The second device sends a second discovery request message, including: The second device sends the second discovery request message if one or more of the following conditions are met: The channel quality between the second device and the first device is better than the fifth threshold. The channel quality between the second device and the other second devices is better than the sixth threshold. The channel quality between the second device and the target third device is better than the seventh threshold; the target third device is the parent device that establishes a relay connection with the second device; The QoS supported by the link between the second device and the first device meets the QoS requirements of the second device. The QoS supported by the link between the second device and the other second devices satisfies the QoS requirements of the second device. The number of hops in the relay connection established between the second device and the network device is less than the maximum number of hops.

42. The method according to claim 41, wherein, The QoS requirements of the second device are determined based on one or more of the following: Implementation of the second device; Network device configuration information; The configuration information of the devices directly connected to the network device in the path where the second device and the network device have established a relay connection.

43. The method according to any one of claims 35-42, wherein, If the second device and the network device have not established a relay connection, the second device sends the second discovery request message via broadcast. If the second device has established a relay connection with the network device, the second device sends the second discovery request message to the target third device via unicast; the target third device is the parent device that has established a relay connection with the second device.

44. The method according to any one of claims 25-32 or 40-43, wherein, The channel quality includes one or more of the following: Channel measurement results; Channel measurement result level.

45. The method according to claim 44, wherein, The channel measurement results and / or channel measurement result levels are obtained by a sub-device in the link measuring one or more of the following information transmitted between two devices in the link: Lateral reference signal; Side-line data channel; Side-line control channel; Second discovery message; Downward reference signal; Downlink data channel; Downlink control channel.

46. ​​The method according to any one of claims 20-45, wherein, The first device is a remote device; The second device, as well as one or more third devices, are devices capable of providing relay services.

47. A communication method, the method comprising: The third device sends a second discovery message; The second discovery message includes relevant information for each of one or more second paths supported by the third device; the second path is a transmission path between the third device and a network device, and the second path includes single-hop or multi-hop links; the first discovery message is related to the second discovery message, and the first discovery message is used to select a target relay device and / or a target path. path.

48. The method according to claim 47, wherein, The relevant information for the second path includes one or more of the following: Information about the network devices being accessed; QoS information supported by the path; Information related to each hop link in the path.

49. The method according to claim 48, wherein, The relevant information for each hop link includes one or more of the following: Channel quality between two devices in a link; QoS information supported by the link; RRC status of sub-devices in the link; Identification information of sub-devices in the link.

50. The method according to claim 48 or 49, wherein, The relevant information of the network device includes one or more of the following: Community signage information; Maximum number of hops supported; Does it support relay services from idle or inactive devices? 51. The method according to any one of claims 48-50, wherein, The QoS information supported by the path, and / or the QoS information supported by the link, includes one or more of the following: Delay information; Traffic information; Error probability information; QoS level.

52. The method according to any one of claims 47-51, wherein, The third device is directly connected to the network device, and the third device sends a second discovery message, including: The third device sends the second discovery message if one or more of the following conditions are met: The channel quality between the third device and the network device is better than the eighth threshold value; The QoS information supported by the link between the third device and the network device satisfies the remaining QoS requirements; the remaining QoS requirements are determined based on the end-to-end QoS requirement information and the QoS information supported by the link between the third device and the first device. The QoS information supported by the link between the third device and the network device and the QoS information supported by the link between the third device and the first device satisfy the end-to-end QoS requirements.

53. The method according to claim 52, wherein, The eighth threshold value is determined based on one or more of the following: Network configuration information; Predefined information; The second discovery request message includes a second threshold value corresponding to each hop link; the eighth threshold value is determined based on the number of hops corresponding to the links between the three devices and the network device and the second threshold value.

54. The method according to any one of claims 47-53, wherein, The second discovery message is either a second discovery announcement message or a second discovery response message.

55. The method according to any one of claims 47-54, wherein, The second discovery message is a second discovery response message. Before the third device sends the second discovery response message, it also includes: The third device receives a second discovery request message, and the second discovery response message is associated with the second discovery request message.

56. The method according to claim 55, wherein, The second discovery request message includes one or more of the following: Channel quality between the second device and the first device; Channel quality between the second device and the other second devices; QoS requirement information between the second device and the network device; The QoS requirement information between the second device and the network device is based on the end-to-end QoS requirement information and the QoS determination supported by the link between the second device and the first device; QoS requirement information of the link between the second device and the first device; QoS requirement information of the link between the second device and the other second devices; Remaining hops; the remaining hops are determined based on the maximum hops and the hops between the first device and the second device.

57. The method according to any one of claims 48-53, 56, wherein, The channel quality includes one or more of the following: Channel measurement results; Channel measurement result level.

58. The method according to claim 57, wherein, The channel measurement results and / or channel measurement result levels are obtained by a sub-device in the link measuring one or more of the following information transmitted between two devices in the link: Lateral reference signal; Side-line data channel; Side-line control channel; Second discovery message; Downward reference signal; Downlink data channel; Downlink control channel.

59. The method according to any one of claims 47-58, wherein, The second device and the third device are devices capable of providing relay services.

60. A communication device applied to a first device, the device comprising: The first receiving unit is configured to receive a first discovery message sent by one or more second devices. The first discovery message includes relevant information about each of the one or more first paths supported by the second devices. The first path is a transmission path between the second devices and a network device, and the first path includes a single-hop link or a multi-hop link. The first selection unit is configured to select a target relay device and / or a target path based on the first discovery message, wherein the target relay device is one of the one or more second devices, and the target path is one of the first paths supported by the one or more second devices.

61. A communication device applied to a second device, the device comprising: The second sending unit is configured to send a first discovery message, the first discovery message including relevant information of each of one or more first paths supported by the second device; the first path is a transmission path between the second device and a network device, the first path including a single-hop link or a multi-hop link; the first discovery message is used to select a target relay device and / or a target path.

62. A communication device applied to a third device, the device comprising: The third sending unit is configured to send the second discovery message; The second discovery message includes relevant information about each of the one or more second paths supported by the third device; the second path is a transmission path between the third device and a network device, and the second path includes single-hop or multi-hop links; the first discovery message is related to the second discovery message, and the first discovery message is used to select a target relay device and / or a target path.

63. A communication device, comprising: A processor and a memory for storing a computer program, the processor for calling and running the computer program stored in the memory to perform the method as claimed in any one of claims 1 to 10, or claims 20 to 46, or claims 47 to 59.

64. A chip, comprising: A processor for retrieving and running a computer program from memory, causing a device having the chip mounted to perform the method of any one of claims 1 to 10, or claims 20 to 46, or claims 47 to 59.

65. A computer-readable storage medium for storing a computer program that causes a computer to perform the method as claimed in any one of claims 1 to 10, or claims 20 to 46, or claims 47 to 59.

66. A computer program product comprising computer program instructions that cause a computer to perform the method as claimed in any one of claims 1 to 10, or claims 20 to 46, or claims 47 to 59.

67. A computer program that causes a computer to perform the method as claimed in any one of claims 1 to 10, or claims 20 to 46, or claims 47 to 59.

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