Path switching methods, apparatuses, storage medium and program product

Abstract

The present disclosure provides path switching methods, apparatuses, a storage medium, and a program product. A method comprises: receiving a path measurement report; and, on the basis of the path measurement report, making a path switching decision on a second node.

Description

Path switching method and apparatus, storage medium, and program product

[0001] This application claims priority to Chinese Patent Application No. 202411089104.4, filed on August 8, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure relates to the technical field of communication, and in particular, to a path switching method and apparatus, a storage medium, and a program product. BACKGROUND

[0003] In the 3rd Generation Partnership Project (3GPP) standard protocol, User Equipment to Network (U2N) relay allows network coverage to be extended to Remote User Equipment (UE). SUMMARY

[0004] Embodiments of the present disclosure provide a path switching method and apparatus, a storage medium, and a program product.

[0005] In a first aspect, a path switching method is provided and applied to a first node. The method includes receiving a path measurement report, and making a decision on path switching of a second node based on the path measurement report.

[0006] In a second aspect, a path switching method is provided and applied to a second node. The method includes sending a path measurement report.

[0007] In a third aspect, a communication apparatus is provided and applied to a first node. The apparatus includes a receiving unit and a processing unit. The receiving unit is configured to receive a path measurement report. The processing unit is configured to make a decision on path switching of a second node based on the path measurement report.

[0008] In a fourth aspect, a communication apparatus is provided and applied to a second node. The apparatus includes a sending unit. The sending unit is configured to send a path measurement report.

[0009] In a fifth aspect, a communication apparatus is provided. The communication apparatus includes a processor and a memory. The memory and the processor are coupled; the memory is configured to store instructions executable by the processor; and the processor is configured to execute the instructions to enable the communication apparatus to implement the method provided in the first aspect or the second aspect.

[0010] In a sixth aspect, a computer-readable storage medium is provided. The computer-readable storage medium stores computer instructions. When the computer instructions are run on a computer, the computer is caused to perform the method provided in the first aspect or the second aspect.

[0011] In a seventh aspect, a computer program product containing computer instructions is provided. When the computer instructions are run on a computer, the computer is caused to perform the method provided in the first aspect or the second aspect. BRIEF DESCRIPTION OF DRAWINGS

[0012] The accompanying drawings are used to provide a further understanding of the technical solutions of the present disclosure, and constitute a part of the specification, and are used to explain the technical solutions of the present disclosure together with the embodiments of the present disclosure, and do not constitute a limitation to the technical solutions of the present disclosure.

[0013] FIG. 1 is a schematic diagram of a scenario of multi-hop sidelink relay according to some embodiments;

[0014] FIG. 2 is a schematic diagram of a tree topology of multi-hop sidelink relay according to some embodiments;

[0015] FIG. 3 is a schematic diagram of a structure of a communication system according to some embodiments;

[0016] FIG. 4 is a flowchart of a path switching method according to some embodiments;

[0017] FIG. 5 is a schematic diagram of a structure of another communication system according to some embodiments;

[0018] FIG. 6 is another flowchart of a path switching method according to some embodiments;

[0019] FIG. 7 is an interaction flowchart of switching from a direct path to a multi-hop relay path according to some embodiments;

[0020] FIG. 8 is a block diagram of a communication apparatus according to some embodiments;

[0021] FIG. 9 is a block diagram of another communication apparatus according to some embodiments;

[0022] FIG. 10 is a block diagram of still another communication apparatus according to some embodiments. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present disclosure will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present disclosure. However, the described embodiments are only some of the embodiments of the present disclosure, but not all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the scope of protection of the present disclosure.

[0024] Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to". As used herein, the terms "example" and "exemplary" indicate functions, structures, or characteristics which could be combined in any suitable manner to produce yet further embodiments. As used herein, the term "or" as used herein, without limitation, can be any logical combination of its elements. As used herein, the terms "first", "second", and the like, do not imply relative importance or a specific order, but are used to distinguish one element from another. As used herein, the term "a" or "an" shall not be construed to mean "one and only one" unless specifically indicated otherwise.

[0025] As used herein, the terms "first", "second", and the like, do not imply relative importance or a specific order but are used to distinguish one element from another. As used herein, the term "a" or "an" shall not be construed to mean "one and only one" unless specifically indicated otherwise.

[0026] In the description of the present disclosure, the meaning of "a plurality of" is two or more unless otherwise specified.

[0027] In addition, the use of "based on" means open and inclusive, as the process, step, calculation, or other action based on one or more stated conditions or values can be based on additional conditions or values beyond those stated.

[0028] In the 3rd Generation Partnership Project (3GPP) standard protocol, User Equipment to Network (U2N) relay allows network coverage to be extended to Remote User Equipment (UE), but only through a relay UE located in the coverage. Considering the relatively short distance of Sidelink (SL), this single-hop method has certain limitations, and using multi-hop relay can provide more reasonable coverage extension for U2N relay.

[0029] Extending single-hop U2N relay to multi-hop U2N relay will open up a variety of new application scenarios. For example, in factory sensor and smart metering scenarios, Internet of Things devices in unfavorable deployment locations will be able to connect; in addition, even if the companion smartphone of a smartwatch is out of coverage, the smartwatch can still benefit from connecting to the network through another UE and establish a connection with the smartphone. FIG. 1 is a schematic diagram of a multi-hop sidelink relay scenario according to some embodiments. As shown in FIG. 1, UEs are connected through a Proximity Communication 5 (PC5) interface, relay UE1 acts as a U2N relay UE, connects to a Generation NodeB (gNB) through a User Equipment to gNodeB interface (Uu interface), and provides U2N relay services for downstream relay UEs or remote UEs. The remote UE acts as a U2N remote UE, and the remote UE establishes a Protocol Data Unit (PDU) session or a Data Radio Bearer (DRB) with the network. Data transmission between the remote UE and the gNB is forwarded via the multi-hop relay UE.

[0030] FIG. 2 is a schematic diagram of a tree topology of a multi-hop sidelink relay according to some embodiments. A relay UE directly connected to a gNB through a Uu interface can be referred to as a root node relay or a root node U2N relay UE (such as relay UE1 or relay UE4). For a remote UE, its first-hop relay UE is its access relay UE; for example, the access relay (i.e., access U2N relay) of remote UE1 is relay UE2, and the access relay of remote UE2 is relay UE3. A relay UE other than a root node relay can be referred to as an intermediate relay UE, such as relay UE5, relay UE6, relay UE2, and relay UE3. A relay UE (such as relay UE5) can be an access relay UE for a remote UE (such as remote UE3) and also an intermediate relay UE for other downstream UEs. For relay UE5, the node serving relay UE5 is relay UE4, which is referred to as a parent relay or a serving relay of relay UE5. The nodes served by relay UE5 are remote UE3 and relay UE6, which can be collectively referred to as child nodes or served nodes of relay UE5.

[0031] Extending from single-hop U2N relay to multi-hop U2N relay requires enhancements to relay discovery and relay selection or reselection mechanisms. Adaptation layer protocols and control plane procedures need to be enhanced to support multi-hop U2N relay transmission. According to quality of service (QoS) requirements, in order to still meet the delay requirements under the delay introduced by the relay, QoS in multi-hop U2N becomes particularly important.

[0032] Based on this, the embodiments of the present disclosure provide a path switching method and device, a storage medium and a program product. The first node makes a decision on path switching of the second node based on a path measurement report, so that the second node can timely perform path switching, and the path after the second node performs path switching can guarantee the quality of service, thereby guaranteeing the quality of service in the multi-hop U2N scenario, and the second node timely performs path switching, thereby guaranteeing the mobility robustness and service continuity in the multi-hop U2N scenario.

[0033] The scheme of the embodiments of the present disclosure will be described below with reference to the drawings.

[0034] The technical solutions provided by the embodiments of the present disclosure can be applied to various mobile communication networks, for example, a New Radio (NR) mobile communication network using the 5th Generation Mobile Networks (5G) mobile communication technology, a future mobile communication network (such as a 6G wireless communication system), or a multi-communication convergence system, and the present disclosure does not limit this.

[0035] FIG. 3 shows a structural schematic diagram of a communication system according to some embodiments. As shown in FIG. 3, the communication system includes, but is not limited to, a plurality of terminals (for example, terminal 11, terminal 12, terminal 13, and terminal 14) and a base station 20. The plurality of terminals and the base station 20 can perform wireless signal transmission, reception, and related interactions.

[0036] In some embodiments, the base station described above can be any one of an Evolution NodeB (eNB), a next-generation base station, a Transmission Receive Point (TRP), a Transmission Point (TP), a relay node, a Reconfigurable Intelligence Surface (RIS), and some other access node. According to the size of the service coverage area provided, the base station can be further divided into a macro base station for providing a macro cell, a micro base station for providing a micro cell, and a femto base station for providing a femto cell. As wireless communication technologies continue to evolve, future base stations can also be referred to by other names.

[0037] In some embodiments, the terminal described above can be a device with wireless transceiver functions, such as a mobile phone, a tablet computer, a wearable device, a vehicle-mounted device, an Augmented Reality (AR) device or a Virtual Reality (VR) device, a notebook computer, an Ultra-mobile Personal Computer (UMPC), a netbook, a Personal Digital Assistant (PDA), an Internet of Things terminal, and the like. The present disclosure does not limit the type of terminal.

[0038] As shown in FIG. 3, a plurality of terminals can be connected through a PC5 interface, and a terminal and a base station 20 can be connected through a Uu interface. As described above, the terminal 11 can be referred to as a remote UE or a remote node, and the terminals 12, 13 and 14 can be referred to as relay UEs or relay nodes. In one aspect, when the terminal 11 is not located in the coverage of the base station 20, the terminal 11 is connected to the base station 20 through a relay path composed of the terminals 12, 13 and 14, and the terminal 11 and the terminal 12 are connected through a first hop, the terminal 12 and the terminal 13 are connected through a second hop, and the terminal 13 and the terminal 14 are connected through a last hop. In another aspect, when the terminal 11 moves into the coverage of the base station 20, the terminal 11 can also be switched to a direct connection path through the Uu interface to be connected to the base station 20.

[0039] It should be understood that FIG. 3 is an exemplary structure diagram, and the number of devices included in the communication system shown in FIG. 3 is not limited, for example, the number of terminals and base stations is not limited. In addition to the devices shown in FIG. 1, the communication system shown in FIG. 3 can also include other devices, which are not limited by the present disclosure.

[0040] As shown in FIG. 4, some embodiments of the present disclosure provide a path switching method, which is applied to a first node, and the first node can be the base station 20 shown in FIG. 3. The method includes the following steps S101 and S102:

[0041] In S101, a path measurement report is received.

[0042] The path measurement report is used for path switching decision of a second node. The second node is a remote UE, and in combination with the communication system shown in FIG. 3, the second node can be the terminal 11.

[0043] The receiving of the path measurement report can include the following examples 1 to 3:

[0044] In example 1, the path measurement report reported by the second node based on a first measurement event is received.

[0045] The first measurement event is related to the type of at least one of the source path or the candidate path of the second node, that is, the type of at least one of the different source paths or the candidate paths of the second node can correspond to different first measurement events. The source path is a communication path between the first node and the second node, and the type of the source path includes a direct connection path and a relay path, and the relay path includes a single-hop relay path and a multi-hop (MH) relay path. The candidate path is a communication path other than the currently applied communication path between the second node and the first node. For example, assuming that the second node currently communicates with the first node through a direct connection path, if the second node moves at this time and can communicate with the first node through a relay path, the relay path is a candidate path of the second node.

[0046] In some embodiments, the source path is a relay path, and the candidate path includes a direct connection path and a relay path; or the source path is a direct connection path, and the candidate path includes a relay path.

[0047] In combination with the communication system shown in FIG. 3, when the terminal 11 is located in the coverage range of the base station 20, the terminal 11 is directly connected with the base station 20 through the Uu interface. At this time, the path between the terminal 11 and the base station 20 is a direct connection path.

[0048] When the terminal 11 is not located in the coverage range of the base station 20, assuming that the terminal 12 is connected with the base station 20 through the Uu interface, the terminal 11 can be connected with the base station 20 through the terminal 12, and the terminal 11 and the terminal 12 are the first hop. At this time, the path between the terminal 11 and the base station 20 is a single-hop relay path. Assuming that the terminal 11 is connected with the base station 20 through the relay path composed of the terminal 12, the terminal 13 and the terminal 14, at this time, the path between the terminal 11 and the base station 20 is a multi-hop relay path.

[0049] In some embodiments, the first measurement event includes at least one of:

[0050] Event 1, detecting that the link quality between the second node and the first relay node in the source path is less than or equal to a first threshold value, and detecting that the link quality of the direct connection path between the second node and the first node is greater than or equal to a second threshold value;

[0051] Event 2, detecting that the link quality between the second node and the first relay node in the source path is less than or equal to a third threshold value;

[0052] Event 3.1, receiving first indication information, the first indication information being used to indicate that the link quality of a target link in the source path is deteriorated or less than or equal to a fourth threshold value;

[0053] Event 3.2, the link quality of a relay node other than the first relay node in the source path is less than or equal to a fifth threshold value; or

[0054] Event 4, detecting that there exists a candidate path with relay hop count less than or equal to target hop count M, and link quality between the second node and the first relay node in the candidate path is greater than or equal to the sixth threshold. The target hop count M is the relay hop count of the source path or a preset value.

[0055] In some embodiments, the first threshold to the sixth threshold are configured for the second node.

[0056] In some embodiments, the link quality is PC5 link quality.

[0057] The event 1 can be understood as that the link quality between the second node and the serving relay node of the second node is less than or equal to the first threshold, and the link quality of the direct path between the second node and the first node is greater than or equal to the second threshold. In combination with the communication system shown in the above Fig. 3, the link quality between the terminal 11 and the terminal 12 is less than or equal to the first threshold, and the link quality of the direct path between the terminal 11 and the base station 20 is greater than or equal to the second threshold.

[0058] It should be understood that the event 1 represents that the link quality between the terminal 11 and the terminal 12 is poor and the link quality of the direct path between the terminal 11 and the base station 20 is good, which represents that the terminal 11 can enter the coverage range of the base station 20, and the terminal 11 can be directly connected with the base station 20. Therefore, the terminal 11 can send a path measurement report to the base station 20, and the base station 20 can determine whether the terminal 11 needs to perform path switching.

[0059] The event 2 can be understood as that the link quality between the second node and the serving relay node of the second node is less than or equal to the third threshold. That is, the link quality between the terminal 11 and the terminal 12 is less than or equal to the third threshold. Therefore, the terminal 11 can send a path measurement report to the base station 20, and the base station 20 can determine whether the terminal 11 needs to perform path switching.

[0060] In the above event 3.1, receiving the first indication information can be receiving the first indication information sent by the fourth node, or receiving the first indication information sent by the fifth node and forwarded by the fourth node. Receiving the first indication information sent by the fifth node and forwarded by the fourth node can be understood as that the fifth node sends the first indication information to the fourth node, and the fourth node forwards the first indication information to the second node. The fourth node is the first relay node in the source path of the second node, and the fifth node is the intermediate relay node in the source path of the second node. For example, the fourth node is the terminal 12 shown in the above Fig. 3, and the fifth node is the terminal 13 shown in the above Fig. 3. The third node is the last relay node in the source path of the second node. For example, the third node is the terminal 14 shown in the above Fig. 3.

[0061] In some embodiments, the first relay node can be referred to as a First Relay UE, and the last relay node can be referred to as a Last Relay UE or a Root Relay UE.

[0062] In the case that the received first indication information is the first indication information sent by the fourth node, the target link is the link between the fourth node and the fifth node, i.e., the second hop shown in FIG. 3. Alternatively, in the case that the fourth node forwards the first indication information sent by the fifth node, the target link is the link between the fifth node and the third node, i.e., the last hop shown in FIG. 3. The target link can be indicated by the node identifier of the relay node. For example, the first indication information contains the node identifier of the fifth node and the link quality (or an indication that the link quality is lower than a threshold); at this time, the first indication information indicates the link quality (or the link quality is lower than a threshold) between the fifth node and its upper node (e.g., the third node).

[0063] In event 3.2 described above, the link quality of the non-first relay node in the source path can refer to the link quality between the other relay node in the source path except the first relay node and the service relay node of the other relay node. For example, taking the non-first relay node as the terminal 13 as an example, the link quality of the non-first relay node can refer to the link quality between the terminal 13 and the terminal 14.

[0064] That is, for each relay node in the source path, each relay node detects the link quality between the relay node and the service relay node of the relay node, and sends the link quality between the relay node and the service relay node of the relay node to the child relay node of the relay node until it is passed to the second node.

[0065] Event 4 will be introduced below in combination with FIG. 5. For example, FIG. 5 is a structural schematic diagram of another communication system according to some embodiments. Referring to FIG. 5, the communication system shown in FIG. 5 adds the terminal 15 compared with the communication system shown in FIG. 3. If the terminal 11 is connected in communication with the base station 20 through the terminal 12, the terminal 13, and the terminal 14, the relay hop number between the terminal 11 and the base station 20 is 3. If the terminal 11 is connected with the base station 20 through the terminal 15, the relay hop number between the terminal 11 and the base station 20 is 1.

[0066] In one scenario, the UE 11 is originally connected with the base station 20 or the network through a multi-hop relay, when the UE 11 moves and detects a relay path with less relay hops or a single-hop relay path, the UE 11 can switch to the single-hop relay path or the relay path with less relay hops to connect with the base station 20. For example, after the terminal 11 detects the terminal 15, the relay hop number of the candidate path between the terminal 11 and the base station 20 is 1, which is less than the relay hop number 3 of the original path between the terminal 11 and the base station 20, and in the case that the terminal 11 detects that the link quality between the terminal 11 and the terminal 15 is greater than or equal to the sixth threshold value, the terminal 11 can send a path measurement report to the base station 20, and the base station 20 determines whether the terminal 11 needs to perform path switching.

[0067] In some embodiments, the path measurement report includes at least one of the following: measurement information of the source path or measurement information of the candidate path.

[0068] Taking the multi-hop relay path as an example, the measurement information of the candidate path includes at least one of the following:

[0069] The node identifier of the first relay node in the candidate path;

[0070] The link quality between the first relay node and the second node in the candidate path;

[0071] The node identifier of the last relay node in the candidate path, for example, the last / root relay UE identity (ID);

[0072] The cell identifier of the last relay node in the candidate path;

[0073] The relay hop number of the candidate path;

[0074] The node identifier of the intermediate relay node of the candidate path; or

[0075] The link quality between the relay node and the upper node of the relay node in the candidate path.

[0076] The node identity of the first relay node can be denoted as first relay UE ID. The node identity of the last relay node can be denoted as last / root relay UE ID. The cell identity can be replaced by a serving cell identity. The relay hop number is the number of relay nodes in the candidate path, including the first relay node and the last relay node. The intermediate relay node can be understood as a relay node located in the middle of the candidate path, such as terminal 12, terminal 13. The link quality between the relay node and the upper node of the relay node can be understood as the link quality between a relay node and the serving relay node of the relay node. For example, taking the relay node as terminal 12, the upper node of the relay node is terminal 13.

[0077] In some embodiments, the relay hop number of the candidate path is less than or equal to a preset value, which is configured for the first node. The preset value can have other names, such as maximum relay hop number, which is not limited in the disclosure. That is, the second node only reports the measurement information of the candidate path whose relay hop number does not exceed (i.e., is less than or equal to) the maximum relay hop number.

[0078] In some embodiments, the path measurement report further includes Uu measurement information.

[0079] It should be understood that, in the case of satisfying any of the above first measurement events, the second node can send a path measurement report to the first node, so that the first node makes a path switching decision based on the path measurement report.

[0080] In some embodiments, in the above example 1, before receiving the path measurement report reported by the second node based on the first measurement event, the first node sends first configuration information to the second node, the first configuration information being used to configure at least one of the content of the first measurement event or the content of the path measurement report. Accordingly, the second node receives the first configuration information and determines at least one of the content of the first measurement event or the content of the path measurement report based on the first configuration information.

[0081] In some embodiments, the first configuration information includes the first threshold to the sixth threshold.

[0082] Example 2, receiving the path measurement report reported by the relay node in the source path of the second node based on the second measurement event.

[0083] The second measurement event is detecting that the link quality of the relay node related link is less than or equal to a fourth threshold. The relay node in the source path of the second node can be any one of the plurality of terminals shown in the above FIG. 3 except terminal 11. Taking the relay node in the source path of the second node as terminal 12 for example, the link quality of the relay node related link can refer to the link quality of the link between terminal 12 and terminal 11.

[0084] In some embodiments, the second measurement event is detecting a SL Radio Link Failure (RLF). That is, in the case that the relay node in the source path of the second node detects that the link quality of the relay node related link is less than or equal to a fourth threshold value, or detects a SL RLF, the relay node in the source path of the second node sends a path measurement report to the first node.

[0085] In some embodiments, the path measurement report comprises at least one of:

[0086] a node identity of a child relay node (also referred to as a next level node) of the relay node in the source path of the second node, for example, taking the relay node in the source path of the second node as the terminal 12, the node identity of the child relay node of the relay node in the source path of the second node is the node identity of the terminal 11;

[0087] a link quality between the relay node in the source path of the second node and the child relay node of the relay node; or

[0088] indication information for indicating that the link quality between the relay node in the source path of the second node and the child relay node of the relay node is less than or equal to the fourth threshold value.

[0089] Based on the embodiment shown in Example 2, the relay node in the source path of the second node detects the link quality of the relay node related link during operation. In the case that the link quality of the relay node related link is detected to be less than or equal to the fourth threshold value or a SL RLF occurs, the link quality of the relay node related link becomes poor, which may not guarantee the service quality in the multi-hop U2N scenario, and then the relay node sends a path measurement report to the first node, so that the first node makes a path switching decision based on the path measurement report, so as to facilitate the second node to perform path switching in time, which helps to guarantee the service quality in the multi-hop U2N scenario.

[0090] In some embodiments, in the above Example 2, before receiving the path measurement report reported by the relay node in the source path of the second node based on the second measurement event, the first node sends second configuration information to the relay node in the source path of the second node, and the second configuration information is used to configure the content of the second measurement event. Accordingly, the relay node in the source path of the second node receives the second configuration information and determines the content of the second measurement event based on the second configuration information.

[0091] In some embodiments, the second configuration information comprises the fourth threshold value.

[0092] That is, the first node sends the second configuration information to each relay node on the source path of the second node, containing the measurement of the serving / parent relay node of the relay node and the measurement of the served / child relay node. A relay node sends the PC5 link quality between the relay node and the parent relay node of the relay node to the child relay node of the relay node, and gradually passes down until it is sent to the second node. The relay node can also directly send the path measurement report or result between the relay node and the child relay node of the relay node to the first node.

[0093] Example 3, receiving a path measurement report reported by a third node based on a third measurement event.

[0094] As described above, the third node is the last relay node on the source path of the second node, for example, it can be the terminal 14 shown in the above FIG. 3.

[0095] In some embodiments, the third measurement event includes detecting that the signal reception power of the second node is greater than or equal to a seventh threshold value. The seventh threshold value is configured by the first node.

[0096] The signal reception power includes a sidelink discovery reference signal received power (SD-RSRP) and a sidelink communication reference signal received power (SL-RSRP).

[0097] In some embodiments, the path measurement report includes at least one of the following: a node identifier of the second node or a link quality between the third node and the second node.

[0098] The node identifier of the second node includes a Layer 2 (L2) ID of the second node or a local ID of the second node.

[0099] It should be understood that the third node is located on the source path of the second node, and the third node belongs to the serving relay node of the second node. That is, the third node detects the signal reception power of the second node on the service path of the third node during operation. In the case where the signal reception power of the second node is greater than or equal to the seventh threshold value, it means that the second node may have operational abnormalities and may not be able to guarantee the service quality in the multi-hop U2N scenario, and then the third node sends the path measurement report to the first node, so that the first node makes a path switching decision based on the path measurement report, so as to facilitate the second node to perform path switching in time, which helps to guarantee the service quality in the multi-hop U2N scenario.

[0100] In some embodiments, in Example 3 above, before receiving the path measurement report reported by the third node based on the third measurement event, the first node sends third configuration information to the third node, the third configuration information being used to configure at least one of the content of the third measurement event or the content of the path measurement report. Accordingly, the third node receives the third configuration information and determines at least one of the content of the third measurement event or the content of the path measurement report based on the third configuration information.

[0101] In some embodiments, the third configuration information includes the seventh threshold value described above.

[0102] In S102, a decision is made on path switching of the second node based on the path measurement report.

[0103] In some examples, if the first node determines that there is a direct connection path between the first node and the second node based on the path measurement report, the first node can determine to switch the first node to the direct connection path.

[0104] In other examples, if the first node determines that there is a relay path with less relay hops than the current relay hops between the first node and the second node based on the path measurement report, the first node can determine to switch the first node to the relay path.

[0105] In some embodiments of the present disclosure, the first node makes a decision on path switching of the second node based on the path measurement report, so that the second node can timely perform path switching, and the path after the path switching of the second node can guarantee the quality of service, ensuring the quality of service in the multi-hop U2N scenario, and the timely path switching of the second node ensures the mobility robustness and service continuity in the multi-hop U2N scenario. For example, in one scenario, the second node is originally connected to the first node or the network directly through a Uu link, when the second node detects that the quality of the Uu link becomes poor after moving, and detects that there is a multi-hop relay path to the first node, the second node can send a path measurement report to the first node, and the first node determines whether the second node can switch to the multi-hop relay path to connect to the first node. In another scenario, the second node is originally connected to the first node through a single-hop relay path, when the second node or the relay node moves, the second node detects that the quality of the PC5 link between the second node and the relay node becomes poor, and detects that there is a multi-hop relay path to the first node, the second node can send a path measurement report to the first node, and the first node determines whether the second node can switch to the multi-hop relay path to connect to the first node, thereby ensuring the quality of service, mobility robustness and service continuity in the multi-hop U2N scenario.

[0106] In some embodiments, in a case that the first node determines to perform path switching for the second node based on the path measurement report, the first node sends a switching configuration of the target path to the second node to facilitate the second node to perform path switching based on the switching configuration of the target path. The target path is a path selected by the first node for the second node.

[0107] For example, the second node is originally connected to the first node through a multi-hop relay. When the second node moves into the coverage of the first node, it can switch to a direct connection path to connect to the first node, and the target path is the direct connection path. The first node sends the switching configuration of the target path to the second node, which can be that the first node sends a radio resource control (RRC) reconfiguration message to the second node, and the RRC reconfiguration message includes the switching configuration of the target path. In this way, RRC Reconfiguration With Synchronization (RRC Reconfiguration With Sync) and T304 (a kind of timer) are multiplexed.

[0108] For another example, the second node is originally connected to the first node through a multi-hop relay. When the first node moves, the second node detects a relay path with fewer relay hops or a single-hop relay path, and then the second node can switch to the single-hop relay path or the relay path with fewer relay hops to connect to the first node. At this time, the target path is the relay path with fewer relay hops or the single-hop relay path, and the switching configuration of the target path sent by the first node is the configuration of the relay path with fewer relay hops or the configuration of the single-hop relay path.

[0109] In some embodiments, the switching configuration of the target path includes at least one of the following: a sequence number of the target path, path information of the target path, a number of relay hops of the target path, or a path switching timer configuration.

[0110] The sequence number of the target path corresponds to the serial number of each path in the path measurement report, such as path sequence number 1 corresponding to the first candidate path in the measurement report, and path sequence number 3 corresponding to the third candidate path in the measurement report. The path information of the target path includes the node identifier of each relay node in the target path, such as including first relay UE ID, second relay UE ID, and so on until last relay UE ID.

[0111] In some embodiments, in a case that the first node determines to perform path switching for the second node based on the path measurement report, the first node sends the configuration information of the target path to the relay nodes in the target path to inform the relay nodes in the target path that a new remote node has joined.

[0112] In some examples, for the first relay node in the target path, the first node sends the configuration information of the target path to the first relay node in the target path, in a case that the first relay node is in a radio resource control (RRC) connected state. The configuration information of the target path includes at least one of: a mapping relationship between a Uu bearer of the second node and an uplink PC5 radio link control (RLC) channel, a mapping relationship between the Uu bearer of the second node and a downlink PC5 RLC channel, a mapping relationship between an uplink ingress RLC channel and an egress RLC channel, or a mapping relationship between a downlink ingress RLC channel and an egress RLC channel.

[0113] Accordingly, the first relay node in the target path receives the configuration information of the target path from the first node, and determines that there is a new remote node joining based on the configuration information of the target path, i.e., determines that the second node joins.

[0114] In some examples, for the last relay node in the target path, the first node sends the configuration information of the target path to the last relay node in the target path, in a case that the last relay node is in an RRC connected state. The configuration information of the target path includes at least one of: a node identifier of the second node, a local identifier of the second node, a node identifier of the first relay node in the target path, downlink routing information, a node identifier of each relay node in the target path, a mapping relationship between a Uu bearer of the second node and a PC5 RLC channel, or a mapping relationship between the Uu bearer of the second node and a Uu RLC channel.

[0115] Accordingly, the last relay node in the target path receives the configuration information of the target path from the first node, and determines that there is a new remote node joining based on the configuration information of the target path, i.e., determines that the second node joins.

[0116] In some embodiments, the configuration information of the target path further includes specific path information, Uu RLC channel configuration, and PC5 RLC channel configuration.

[0117] In some embodiments, the downlink routing information includes a node identifier of a downstream relay node of the last relay node that can reach the second node.

[0118] In some examples, for the intermediate relay node in the target path, the first node sends, to the intermediate relay node in the target path, configuration information of the target path in a case that the intermediate relay node is in an RRC connected state. The configuration information of the target path includes at least one of: a mapping relationship between a Uu bearer of the second node and an uplink PC5 RLC channel, a mapping relationship between the Uu bearer of the second node and a downlink PC5 RLC channel, downlink routing information, a mapping relationship between an uplink entering RLC channel and a leaving RLC channel, or a mapping relationship between a downlink entering RLC channel and a leaving RLC channel.

[0119] Correspondingly, the intermediate relay node in the target path receives the configuration information of the target path from the first node, and determines that a new remote node joins, i.e., the second node joins, based on the configuration information of the target path.

[0120] As can be seen from the above, compared with the configuration information of the target path corresponding to the first relay node in the target path, the configuration information of the target path corresponding to the intermediate relay node in the target path further includes downlink routing information.

[0121] In a multi-hop relay scenario, a multi-hop L2 U2N remote UE (i.e., the second node in the above embodiment) communicates with a base station through a relay path of a plurality of intermediate L2 U2N relay UEs (i.e., the intermediate relay nodes in the above embodiment) and a root / last L2 U2N relay UE (i.e., the third node in the above embodiment). Each UE has different UE roles / functions / operations, and when each UE requests a resource from the base station, the base station checks whether the UE has corresponding authorization information, and if the UE has the corresponding authorization information, the base station further provides the UE with corresponding configuration information and resources.

[0122] Based on this, the second node sends node type information to the first node. Correspondingly, the first node receives the node type information sent by the second node, and determines whether the second node can serve as a node type corresponding to the node type information based on the node type information.

[0123] In some embodiments, in order to facilitate the first node to determine whether each node in the network range of the first node can serve as a node type corresponding to node type information of the node, a core network element sends multi-hop relay communication related authorization information to the first node. Correspondingly, the first node receives the multi-hop relay communication related authorization information sent by the core network element, and the authorization information includes at least one of:

[0124] authorization information for serving as a multi-hop L2 U2N remote node;

[0125] authorization information authorizing a remote node of a multi-hop L2 U2N;

[0126] authorization information authorizing an intermediate relay node of a multi-hop L2 U2N;

[0127] authorization information authorizing an intermediate relay operation of a multi-hop L2 U2N;

[0128] authorization information authorizing a root relay node of a multi-hop L2 U2N; or

[0129] authorization information authorizing a root relay operation of a multi-hop L2 U2N.

[0130] The authorization information authorizing a remote node of a multi-hop L2 U2N and the authorization information authorizing a remote operation of a multi-hop L2 U2N can be denoted as multi-hop L2 U2N remote, the authorization information authorizing an intermediate relay node of a multi-hop L2 U2N and the authorization information authorizing an intermediate relay operation of a multi-hop L2 U2N can be denoted as intermediate L2 U2N relay, and the authorization information authorizing a root relay node of a multi-hop L2 U2N and the authorization information authorizing a root relay operation of a multi-hop L2 U2N can be denoted as root / last L2 U2N relay.

[0131] For example, taking the authorization information authorizing a remote node of a multi-hop L2 U2N in the above multiple authorization information as an example, the authorization information authorizing a remote node of a multi-hop L2 U2N can include a node identifier authorizing a remote node of a multi-hop L2 U2N, so that the first node determines which nodes are authorized as remote nodes of a multi-hop L2 U2N based on the node identifier authorizing a remote node of a multi-hop L2 U2N.

[0132] In some examples, the core network network element is an Access and Mobility Management Function (AMF) network element.

[0133] In some embodiments, in the movement of the second node, the first node (i.e., the source base station) sends the authorization information related to the multi-hop relay communication of the second node to the target first node (i.e., the target base station) on the Xn interface. In a centralized unit (CU) and distributed unit (DU) separation architecture, the CU receives the authorization information related to the multi-hop relay communication sent by the core network network element, and sends the authorization information related to the multi-hop relay communication to the DU on the Xn interface.

[0134] In some examples, the first node determines, based on the node type information, whether the second node is capable of acting as a node of the node type corresponding to the node type information, including determining, based on the node type information and the authorization information, whether the second node is capable of acting as a node of the node type corresponding to the node type information. For example, after the first node receives the node type information of the second node, the first node checks whether there is authorization information corresponding to the second node. In the case where there is authorization information corresponding to the second node, the first node determines that the second node is capable of acting as a node of the node type corresponding to the node type information, and then provides the second node with the configuration information and resources related to the multi-hop relay communication.

[0135] In some embodiments, before the first node provides the second node with the configuration information and resources related to the multi-hop relay communication, the second node sends the first node with the capability information related to the multi-hop relay communication. Accordingly, the first node receives the capability information related to the multi-hop relay communication sent by the second node. Then, the first node can determine the capabilities supported by the second node based on the capability information related to the multi-hop relay communication sent by the second node.

[0136] The capability information related to the multi-hop relay communication includes at least one of the following:

[0137] The capability of connecting to the first node through a multi-hop relay path;

[0138] The capability of switching to a multi-hop relay path;

[0139] The list of frequency points supporting the multi-hop relay communication;

[0140] The frequency band combination supporting the multi-hop relay communication;

[0141] The capability of connecting to the first node through a multi-hop relay path of L2 U2N relay; or

[0142] The capability of switching to L2 U2N relay.

[0143] The above embodiments are to illustrate a path switching method provided by some embodiments of the present disclosure from the perspective of the first node. In some embodiments, as shown in FIG. 6, some embodiments of the present disclosure also provide a path switching method applied to the second node. The method can include the following step S201:

[0144] In S201, the path measurement report is sent.

[0145] The path measurement report is used for the first node to make a decision on path switching of the second node.

[0146] In some examples, the second node generates the path measurement report based on the first measurement event; and sends the path measurement report.

[0147] In some embodiments, the second node detects whether the first measurement event is met during operation, generates the path measurement report in the case where the first measurement event is met, and sends the path measurement report to the first node. For the description of the first measurement event and the path measurement report, reference can be made to the corresponding description in the above-described embodiment shown in FIG. 4, which will not be repeated here.

[0148] In some embodiments, the first measurement event is related to the type of at least one of the source path or the candidate path of the second node. The type of the source path includes a direct connection path, a single-hop relay path, and a multi-hop relay path.

[0149] In some embodiments, the first measurement event includes at least one of the following:

[0150] detecting that the link quality between the second node and the first relay node in the source path is less than or equal to a first threshold value, and detecting that the link quality of the direct connection path between the second node and the first node is greater than or equal to a second threshold value;

[0151] detecting that the link quality between the second node and the first relay node in the source path is less than or equal to a third threshold value;

[0152] receiving first indication information, the first indication information being used to indicate that the link quality of a target link in the source path is deteriorated or less than or equal to a fourth threshold value;

[0153] the link quality of a relay node other than the first relay node in the source path is less than or equal to a fifth threshold value; or

[0154] detecting that there is a candidate path with a relay hop count less than or equal to a target hop count, and the link quality between the second node and the first relay node in the candidate path is greater than or equal to a sixth threshold value; the target hop count is the relay hop count of the source path or a preset value.

[0155] In some embodiments, before sending the path measurement report, the second node receives first configuration information from the first node, the first configuration information being used to configure at least one of the content of the first measurement event or the content of the path measurement report. For the description of the first configuration information, reference can be made to the corresponding description in the above-described embodiment shown in FIG. 4, which will not be repeated here. The first configuration information can have other names, such as SL measurement configuration information, which is not limited in the present disclosure.

[0156] In some embodiments, the path measurement report includes at least one of the following: measurement information of the source path or measurement information of the candidate path.

[0157] The source path is a relay path, and the candidate path includes a direct connection path and a relay path; or the source path is a direct connection path, and the candidate path includes a relay path.

[0158] In a case that the candidate path is a multi-hop relay path, the measurement information of the candidate path comprises at least one of:

[0159] a node identity of a first relay node in the candidate path;

[0160] a link quality between the first relay node and a second node in the candidate path;

[0161] a node identity of a last relay node in the candidate path;

[0162] a cell identity of the last relay node in the candidate path;

[0163] a number of relay hops of the candidate path;

[0164] a node identity of an intermediate relay node in the candidate path; or

[0165] a link quality between a relay node and a previous node of the relay node in the candidate path.

[0166] In some embodiments, the number of relay hops of the candidate path is less than or equal to a preset value, which is configured for the first node.

[0167] In some embodiments, the second node receives a handover configuration of the target path from the first node, and then the second node can hand over to the target path to connect with the first node based on the handover configuration of the target path.

[0168] The handover configuration of the target path comprises at least one of: a sequence number of the target path, path information of the target path, a number of relay hops of the target path, or a path handover timer configuration. The path handover timer configuration can also be referred to as a timer configuration associated with path handover.

[0169] In some embodiments, the second node sends capability information related to multi-hop relay communication to the first node, so as to facilitate the first node to determine the capabilities possessed by the second node.

[0170] The capability information related to multi-hop relay communication comprises at least one of:

[0171] a capability of connecting to the first node through a multi-hop relay path;

[0172] a capability of supporting path handover to a multi-hop relay path;

[0173] a list of frequency points supporting multi-hop relay communication;

[0174] a frequency band combination supporting multi-hop relay communication;

[0175] a capability of connecting to the first node through a multi-hop relay path of L2 U2N relay; or

[0176] Supporting the capability of switching to L2 U2N relay.

[0177] In some embodiments, for each relay node on the source path of the second node, the relay node detects, in operation, a link quality between the relay node and an upper level relay node of the relay node, and detects a link quality between the relay node and a lower level relay node of the relay node. When the relay node detects that the link quality between the relay node and the upper level relay node of the relay node is lower than a fourth threshold or an SL RLF occurs, the relay node informs the lower level node of the relay node through a first indication message. If the lower level node is also an intermediate relay node, the lower level node forwards the first indication message to a lower level node of the lower level node, until the first indication message is forwarded to the second node.

[0178] The upper level node of a relay node can be understood as a relay node connected to the relay node in the uplink direction, and the upper level node of a relay node is also the serving relay node or the parent relay node of the relay node. The lower level node of a relay node can be understood as a relay node connected to the relay node in the downlink direction, and the lower level node of a relay node is also the served relay node or the child relay node of the relay node.

[0179] For example, in combination with the communication system shown in FIG. 3, when the terminal 13 detects that the link quality between the terminal 13 and the terminal 14 is less than or equal to the fourth threshold, the terminal 13 sends a first indication message to the terminal 12, and the terminal 12 further forwards the first indication message to the terminal 11. After receiving the first indication message, the terminal 11 determines that event 3.1 in the first measurement event is met, and then the terminal 11 sends a path measurement report to the base station 20.

[0180] Based on the above example, the second node receives a second indication message from the fourth node, the fourth node being the first relay node in the source path of the second node, and the second indication message including at least one of:

[0181] a link quality between the fourth node and an upper level node of the fourth node;

[0182] a link quality between an intermediate relay node in the source path and an upper level node of the intermediate relay node;

[0183] an indication information indicating that the link quality between the intermediate relay node in the source path and the upper level node of the intermediate relay node deteriorates or an SL Radio Link Failure (RLF) occurs;

[0184] a Uu interface link state information of the last relay node in the source path; or

[0185] PC5 RRC information.

[0186] The PC5 RRC information includes at least one of the following: a node identifier of a parent node of the fourth node, a link quality between the fourth node and the parent node of the fourth node, third indication information, a SL RLF, or an identifier of an intermediate relay node in a source path. The third indication information is used to indicate that the link quality between the fourth node and the parent node of the fourth node is less than or equal to a fourth threshold value.

[0187] The Uu interface link state information includes at least one of the following: cell reselection, handover, a Uu RLF, or Uu connection failure indication information. The SL RLF indicates that a SL RLF occurs between the fourth node and the parent node of the fourth node.

[0188] Based on the embodiment shown in FIG. 6, the second node sends a path measurement report to the first node for the first node to make a decision on path switching of the second node, so that the second node can timely perform path switching, and the path after the second node performs path switching can guarantee the service quality, ensuring the service quality in the multi-hop U2N scenario, and the second node timely performs path switching, ensuring the mobile robustness and service continuity in the multi-hop U2N scenario.

[0189] For example, in one scenario, the second node is originally connected with the first node or the network directly through a Uu link. When the second node detects that the Uu link quality becomes poor after moving, and detects that there is a multi-hop relay path to the first node, the second node can send a path measurement report to the first node, and the first node makes a decision on whether the second node can switch to the multi-hop relay path to connect with the first node.

[0190] In another scenario, the second node is originally in communication with the first node through a single-hop relay path. When the second node or the relay node moves, the second node detects that the PC5 link quality between the second node and the relay node becomes poor, and detects that there is a multi-hop relay path to the first node, the second node can send a path measurement report to the first node, and the first node makes a decision on whether the second node can switch to the multi-hop relay path to connect with the first node, thereby guaranteeing the service quality, the mobile robustness and the service continuity in the multi-hop U2N scenario.

[0191] The following examples are used to illustrate the path switching method provided by some embodiments of the present disclosure. The following examples are illustrated by taking terminal 11 as a remote UE, terminal 12 as a first relay UE, terminal 13 as a second relay UE, terminal 14 as a last / root relay UE, and base station 20 as a gNB. For example, the method can include the following examples:

[0192] Embodiment one.

[0193] In one scenario, in combination with the communication system shown in FIG. 3, the remote UE originally communicates with the gNB or network through multi-hop relay. When the remote UE moves into the coverage of the gNB, it can switch to direct Uu path to communicate with the gNB.

[0194] The gNB configures the measurement configuration for the remote UE. The measurement configuration includes a first measurement event that triggers the remote UE to report the path measurement report, i.e., the gNB sends the first configuration information to the remote UE.

[0195] In the multi-hop relay scenario, the first measurement event includes at least one of the following:

[0196] In addition to the two measurement reporting events defined in the 17th release of the 3rd Generation Partnership Project (3GPP R17), such as Event X1: the serving relay UE link quality is lower than a first threshold and the Uu cell link quality is higher than a second threshold (corresponding to the above-mentioned event 1), and Event X2: the serving relay UE link quality is lower than a configured threshold (corresponding to the above-mentioned event 2), new measurement reporting events can also be considered.

[0197] For example, Event X3: the remote UE receives an indication that the link quality of the second hop sent by the first relay UE is deteriorating or lower than a threshold, or receives an indication that the link quality of the last hop forwarded by the first relay UE is deteriorating or lower than a threshold (the indication comes from the second relay UE sent to the first relay UE), corresponding to the above-mentioned event 3.1. Alternatively, the remote UE receives the PC5 link quality of the intermediate relay UE, which is lower than the threshold configured by the gNB (corresponding to the above-mentioned event 3.2).

[0198] When the above measurement reporting event is satisfied, the remote UE sends a path measurement report to the gNB, i.e., the second node sends a path measurement report to the first node. The path measurement report includes at least one of the following: candidate path measurement information, current serving path measurement information, Uu measurement information, so that the gNB initiates path switching for the remote UE. If there is a direct Uu path and the gNB decides to switch the remote UE to the direct Uu path, the gNB sends an RRC reconfiguration message to the remote UE, multiplexing RRC Reconfiguration With Sync and T304.

[0199] In some embodiments, the gNB sends SL measurement configuration to the intermediate relay UE or the root relay UE. The SL measurement configuration can include threshold related to the above measurement reporting event Event X4, i.e., the first node sends the second configuration information to each relay node on the source path of the second node.

[0200] Event X4: The relay UE detects that the PC5 link quality between the relay UE and the child / served node is lower than a configured threshold. The intermediate relay UE not only measures the PC5 link quality between the intermediate relay UE and the parent / serving relay serving the intermediate relay UE, but also measures the PC5 link quality between the intermediate relay UE and the child node (including child relay UE or remote UE) served by the intermediate relay UE. When the PC5 link quality between the intermediate relay UE (e.g., second relay) and its parent relay is lower than a certain threshold or SL RLF occurs, the intermediate relay UE informs its child node through a PC5 RRC message; if the child node is also an intermediate relay UE (e.g., first relay UE), the child node further informs its child node (e.g., remote UE) through a PC5 RRC message. The PC5 RRC message includes at least one of the following: second relay UE ID, PC5 link quality (referring to the PC5 link quality between the second relay and its parent relay) or an indication that the PC5 link quality is lower than a threshold, SL RLF (indicating that SL RLF occurs between the second relay and its parent relay). After the remote UE receives the indication information, it can trigger measurement reporting (satisfy Event X3) so that the gNB initiates path switching for the remote UE.

[0201] When an intermediate relay UE (e.g., first relay UE) or root relay UE measures that the PC5 link quality between it and its certain child node (e.g., remote UE) is lower than a threshold (satisfies Event X4) or SL RLF occurs, the intermediate relay UE or root relay UE triggers measurement reporting and sends a path measurement report to the gNB. That is, the relay node in the source path of the second node reports a path measurement report based on the second measurement event. The path measurement report contains at least one of the following: child node UE ID (e.g., remote UE ID), PC5 link quality (referring to the PC5 link quality between the first relay UE and the remote UE) or an indication that the PC5 link quality is lower than a threshold, or SL RLF. After receiving the measurement report sent by the intermediate relay UE or root relay UE, the gNB can decide whether to configure the remote UE to perform path switching.

[0202] Embodiment two.

[0203] In one scenario, in combination with the communication system shown in FIG. 5, the remote UE originally communicates with the gNB or network through multi-hop relaying. When the remote UE detects a relay path with fewer hops or a single-hop relay path after moving, it can switch to the single-hop relay path or the relay path with fewer hops to communicate with the gNB. Further, two scenarios are included: 1) a new single-hop path or a relay path with fewer hops is detected; 2) a direct PC5 path with the root / last relay UE (or a direct PC5 path with a certain intermediate relay UE) is detected.

[0204] The gNB configures the remote UE to perform measurement, that is, configures the first configuration information. The measurement configuration includes the configuration related to the measurement reporting event, such as measurement reporting event Event X5: the remote UE detects a relay path with fewer hops (or detects an M-hop relay path or detects a relay path with fewer than M hops), and the PC5 link quality between the remote UE and the first relay UE on the relay path is higher than a threshold. M and the link quality threshold are configured by the gNB. It should be understood that Event X5 corresponds to Event 4 described above.

[0205] When the measurement reporting event Event X5 is satisfied, the remote UE triggers to send a path measurement report to the gNB, and the path measurement report contains the measurement information of all candidate paths that satisfy Event X5. For example, the measurement information of each candidate path includes at least one of the following:

[0206] first relay UE ID (i.e., the relay UE directly serving the remote UE);

[0207] PC5 link quality between the remote UE and the first relay UE;

[0208] last / root relay UE ID;

[0209] serving cell identity of the last / root relay UE;

[0210] relay hop count (total number of relay UEs on the relay path, including intermediate relay UEs and the last relay UE);

[0211] each intermediate relay UE ID;

[0212] PC5 link quality between each intermediate relay UE and its parent node.

[0213] After the gNB receives the path measurement report from the remote UE, it decides whether to configure path switching for the remote UE. The switching configuration of path switching includes at least one of the following:

[0214] sequence number of the target path, corresponding to the serialized number of each path in the path measurement report, such as path sequence number 1 corresponding to the first candidate path in the measurement report, path sequence number 3 corresponding to the third candidate path in the measurement report;

[0215] path information of the target path, including node identities of relay nodes in the target path, for example: first relay UE ID, second relay UE ID... until last relay UE ID;

[0216] relay hop count of the target path; or

[0217] timer configuration of path switching.

[0218] The gNB sends SL measurement configuration to the intermediate relay UE, including measurement of serving / parent node and measurement of served / child node. The intermediate relay UE sends the PC5 link quality between the intermediate relay UE and the parent node to the child node, and gradually passes down until sent to the remote UE. The intermediate relay UE sends the path measurement report or result between the intermediate relay UE and the child node to the gNB. Similar to the first embodiment, details are not repeated here.

[0219] In some embodiments, in one way, the gNB sends SL measurement configuration to the root / last relay UE, including measurement of served / child node and measurement of remote UE on the served path, i.e. the first node sends the third configuration information to the third node in the above embodiment. The root relay UE configures the measurement of remote UE on the served path, including measurement reporting event Event X6: the root relay UE detects that the signal (e.g. SD-RSRP or SL-RSRP) of the remote UE on the served path is higher than the threshold value, which is configured by the gNB. When Event X6 is met, the root relay UE triggers measurement reporting, i.e. the third node reports the path measurement report based on the third measurement event in the above embodiment. The path measurement report includes: remote UE ID (L2 ID or local ID), PC5 link quality between the root / last relay UE and the remote UE, Uu interface link state information of the last relay UE. The Uu interface link state information includes at least one of the following: cell reselection, handover, Uu RLF, or Uu connection failure indication information.

[0220] After the gNB receives the path measurement report sent by the root relay UE, it can decide whether to configure path switching for the remote UE and switch the remote UE to the single-hop relay path of the root relay UE. It should be understood that Event X6 corresponds to the third measurement event in the above embodiment.

[0221] Embodiment three.

[0222] In one scenario, remote UE is originally communicating with gNB or network directly through Uu link, when remote UE detects that Uu link quality is getting worse and detects that there is a multi-hop relay path to gNB, then remote UE can switch to the multi-hop relay path to communicate with gNB. In another scenario, remote UE is originally communicating with gNB through a single-hop relay path, when remote UE detects that PC5 link quality between remote UE and relay UE is getting worse and detects that there is a multi-hop relay path to gNB, then remote UE can switch to the multi-hop relay path to communicate with gNB.

[0223] When remote UE detects that Uu link quality is getting worse or detects that PC5 link quality between remote UE and single-hop relay UE is getting worse, and satisfies the measurement reporting configuration, remote UE triggers to send path measurement report to gNB. Path measurement report contains measurement information of candidate paths detected by remote UE, and the measurement information of each candidate path (same as in embodiment two) includes at least one of the following: first relay UE ID, PC5 link quality between remote UE and first relay UE, root / last relay UE ID, serving cell identity of root / last relay UE, relay hop number, each intermediate relay UE ID, or PC5 link quality between each intermediate relay UE and its parent node.

[0224] In some embodiments, gNB configures a maximum relay hop number, and remote UE only reports relay path information whose relay hop number does not exceed the maximum relay hop number.

[0225] After gNB receives the path measurement report of remote UE, gNB decides whether to configure path switching for remote UE. Path switching configuration includes at least one of the following: target path sequence number, path information of target path, relay hop number of target path, or timer configuration associated with path switching. (Same as in embodiment two)

[0226] If the root / last relay UE on the target path configured by gNB is in RRC connected state, gNB sends RRC reconfiguration message to the root / last relay UE, informing that there is a new remote UE joining. The RRC reconfiguration message includes the specific path information, downlink routing information (the downstream or child node identification of the root relay UE that can reach the remote UE), Uu RLC channel configuration, PC5 RLC channel configuration, and the mapping relationship between remote UE Uu bearer and Uu / PC5 RLC channel. For example, the RRC reconfiguration message includes at least one of the following: remote UE ID, remote UE local ID, first relay UE ID, downlink routing information, the identification of each intermediate relay UE, or the mapping relationship between remote UE Uu bearer and Uu / PC5 RLC channel.

[0227] It should be understood that this example corresponds to the content included in the configuration information of the target path for the last relay node in the target path in the above-described embodiments.

[0228] If the first relay UE on the target path configured by gNB is in RRC connected state, gNB sends RRC reconfiguration message to the first relay UE. The RRC reconfiguration message includes at least one of the following: the mapping relationship between remote UE Uu bearer and uplink PC5 RLC channel, the mapping relationship between remote UE Uu bearer and downlink PC5 RLC channel, the mapping relationship between uplink ingress RLC channel and egress RLC channel, and the mapping relationship between downlink ingress RLC channel and egress RLC channel.

[0229] It should be understood that this example corresponds to the content included in the configuration information of the target path for the first relay node in the target path in the above-described embodiments.

[0230] If other intermediate relay UEs (except root / last relay UE and first relay UE) on the target path configured by gNB are in RRC connected state, gNB sends RRC reconfiguration message to the intermediate relay UE. The RRC reconfiguration message contains at least one of the following: mapping relationship between remote UE Uu bearer and uplink PC5 RLC channel, mapping relationship between uplink ingress RLC channel and egress RLC channel, downlink routing information (which can reach remote UE, the downstream or child node identifier of the intermediate relay UE), mapping relationship between remote UE Uu bearer and downlink PC5 RLC channel, mapping relationship between downlink ingress RLC channel and egress RLC channel. That is, compared with the configuration information of the first relay UE, the configuration information of the intermediate relay UE contains additional downlink routing information.

[0231] It should be understood that this example corresponds to the content included in the configuration information of the target path for the intermediate relay nodes in the target path in the above-described embodiments.

[0232] The third embodiment is described below from the perspective of the interaction between the remote UE, the first relay UE, the second relay UE, the last relay UE, and the gNB.

[0233] FIG. 7 shows an interaction flow diagram for switching a direct path to a multi-hop relay path according to some embodiments. Referring to FIG. 7, the exchange flow can include the following steps S0 to S7:

[0234] In S0, the remote UE transmits uplink (UL) / downlink (DL) data with the gNB.

[0235] In some embodiments, the remote UE is located within the coverage of the gNB, and the remote UE transmits uplink / downlink data with the gNB through a direct path.

[0236] In S1, the remote UE sends a measurement configuration report to the gNB.

[0237] In some embodiments, the remote UE sends a measurement configuration report to the gNB when a measurement event is met.

[0238] The measurement configuration report corresponds to the path measurement report in the above embodiments. For the description of the path measurement report, please refer to the description in the above embodiments, which will not be repeated here.

[0239] In S2, the gNB makes the decision of switching to a multi-hop relay path (i.e., gNB Decision of switching to a MH indirect path).

[0240] After receiving the measurement configuration report sent by the remote UE, the gNB makes a path switching decision based on the measurement configuration report.

[0241] In S3a, the gNB sends an RRC reconfiguration message for the remote UE to the last relay UE.

[0242] That is, the gNB sends an RRC Reconfiguration for remote UE to the last relay UE.

[0243] When the gNB decides to instruct a remote UE to perform a path handover, that is, to switch the remote UE from a direct path to a multi-hop relay path, the gNB sends an RRC reconfiguration message for the remote UE to each relay UE on the target path. The RRC reconfiguration message includes the handover configuration for the target path. At this time, the target path is a multi-hop relay path.

[0244] In S3b, the gNB sends an RRC reconfiguration message for the remote UE to the second relay UE.

[0245] In S3c, the gNB sends an RRC reconfiguration message for the remote UE to the first relay UE.

[0246] Thus, through steps S3a, S3b and S3c, each relay UE on the multi-hop relay path knows about the addition of the remote UE and the information of the remote UE.

[0247] In S4, the gNB sends an RRC reconfiguration message to the remote UE.

[0248] That is, the gNB sends an RRC Reconfiguration message to the remote UE, and the RRC reconfiguration message includes the handover configuration of the target path.

[0249] In S5a, the PC5 connection is complete.

[0250] The remote UE, the first relay UE, the second relay UE and the last relay UE establish PC5 connections with each other, i.e., PC5 connection establishment.

[0251] In S6, the remote UE sends an RRC Reconfiguration Complete message to the gNB.

[0252] That is, the remote UE sends an RRC Reconfiguration Complete message to the gNB through the relay UEs.

[0253] In S7, the remote UE transmits UL / DL data with the gNB through the multi-hop relay path.

[0254] Embodiment four.

[0255] In the multi-hop relay scenario, the multi-hop L2 U2N remote UE (i.e., the remote UE in the above embodiments) communicates with the gNB through the relay path of multiple intermediate L2 U2N relay UEs (i.e., the intermediate relay UEs in the above embodiments) and the root / last L2 U2N relay UE (i.e., the root / last relay UE in the above embodiments). Each UE has different UE roles / functions / operations, and when the UE requests resources from the gNB, the gNB checks whether the UE has corresponding authorization information. If the UE has corresponding authorization information, the gNB further provides the UE with corresponding configuration information and resources.

[0256] For example, the gNB receives multi-hop relay communication related authorization information sent by a core network or an AMF network element. The multi-hop relay communication related authorization information includes at least one of the following: multi-hop L2 U2N remote (UE authorization as MH L2 U2N remote UE or UE authorization to perform MH L2 U2N remote operation), intermediate L2 U2N relay (UE authorization as MH intermediate L2 U2N relay UE or UE authorization to perform MH intermediate L2 U2N relay operation), root / last L2 U2N relay (UE authorization as MH root / last L2 U2N relay UE or UE authorization to perform MH root / last L2 U2N relay operation).

[0257] The gNB receives node type information sent by the UE, and the node type information includes at least one of the following: multi-hop L2 U2N remote UE, intermediate L2 U2N relay UE, or root / last L2 U2N relay UE. The gNB checks whether the UE has corresponding authorization information according to the node type information indicated by the UE.

[0258] In the handover procedure, the source gNB sends the authorization information related to the multi-hop relay communication of the UE to the target gNB over the Xn interface. In the gNB CU-DU split architecture, the CU sends the authorization information related to the multi-hop relay communication of the UE to the DU over the Xn interface.

[0259] Before obtaining the multi-hop relay communication related configuration from the gNB, the UE sends the capability information related to the multi-hop relay communication to the gNB. The capability information related to the multi-hop relay communication includes at least one of the following: a capability of supporting the MH U2N relay (a capability of connecting to the gNB through the multi-hop relay path), a capability of supporting the path switching to the multi-hop relay path, a frequency point list supporting the multi-hop relay communication, a frequency band combination supporting the multi-hop relay communication, a capability of supporting the multi-hop relay path connecting to the base station through the traditional L2 U2N relay, and a capability of supporting the switching to the traditional L2 U2N relay.

[0260] The above mainly introduces the scheme provided by the present disclosure from the perspective of interaction between nodes. It can be understood that, in order to implement the above functions, each node, such as the first node or the second node, includes at least one of a corresponding hardware structure or a software module for executing each function. Those skilled in the art should easily realize that, in combination with the algorithm steps of each example described in the embodiments disclosed herein, the present disclosure can be realized in the form of hardware or a combination of hardware and computer software. Whether a certain function is implemented in hardware or computer software driven hardware depends on the specific application and design constraints of the technical solution. Professional technicians 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 disclosure.

[0261] Some embodiments of the present disclosure can divide the functions of the first node or the second node according to the method embodiments described above, for example, each function module can be divided according to each function, or two or more functions can be integrated into one function module. The integrated module can be realized in the form of hardware or software. It should be noted that the division of the modules in some embodiments of the present disclosure is illustrative, and is only a logical function division. In actual implementation, there can be another division manner. Hereinafter, taking the division of each function module according to each function as an example for description.

[0262] FIG. 8 is a block diagram of a communication apparatus according to some embodiments. As shown in FIG. 8, the communication apparatus 30 includes a receiving unit 301 and a processing unit 302. In some embodiments, the communication apparatus 30 further includes a sending unit 303.

[0263] The communication device 30 can be the first node or a chip in the first node. When the communication device 30 is used to implement the functions of the first node in the above embodiments, each unit is used to implement the following functions.

[0264] The receiving unit 301 is configured to receive a path measurement report.

[0265] The processing unit 302 is configured to make a decision on path switching of the second node based on the path measurement report.

[0266] In some embodiments, the receiving unit 301 is configured to receive the path measurement report reported by the second node based on the first measurement event.

[0267] In some embodiments, the sending unit 303 is configured to send first configuration information to the second node. The first configuration information is used to configure at least one of the content of the first measurement event or the content of the path measurement report.

[0268] In some embodiments, the sending unit 303 is configured to send second configuration information to a relay node in the source path of the second node. The second configuration information is used to configure a second measurement event, and the second measurement event is to detect that the link quality of the link related to the relay node is less than or equal to a fourth threshold value.

[0269] In some embodiments, the receiving unit 301 is configured to receive the path measurement report reported by the third node based on the third measurement event. The third node is the last relay node in the source path of the second node.

[0270] In some embodiments, the sending unit 303 is configured to send third configuration information to the third node. The third configuration information is used to configure at least one of the content of the third measurement event or the content of the path measurement report.

[0271] In some embodiments, the sending unit 303 is configured to send switching configuration of the target path to the second node.

[0272] In some embodiments, the sending unit 303 is configured to send configuration information of the target path to a relay node in the target path.

[0273] In some embodiments, the receiving unit 301 is further configured to receive capability information related to multi-hop relay communication sent by the second node.

[0274] In some embodiments, the receiving unit 301 is further configured to receive node type information sent by the second node.

[0275] The processing unit 302 is further configured to determine whether the second node can serve as a node type corresponding to the node type information based on the node type information.

[0276] In some embodiments, the receiving unit 301 is further configured to receive authorization information related to multi-hop relay communication sent by the core network element. The authorization information includes at least one of:

[0277] authorization information authorizing a remote node of the multi-hop L2 U2N;

[0278] authorization information authorizing a remote operation of the multi-hop L2 U2N;

[0279] authorization information authorizing an intermediate relay node of the multi-hop L2 U2N;

[0280] authorization information authorizing an intermediate relay operation of the multi-hop L2 U2N;

[0281] authorization information authorizing a root relay node of the multi-hop L2 U2N; or

[0282] authorization information authorizing a root relay operation of the multi-hop L2 U2N.

[0283] FIG. 9 is a block diagram of another communication apparatus according to some embodiments. As shown in FIG. 9, the communication apparatus 40 includes a sending unit 401. In some embodiments, the communication apparatus 40 further includes a receiving unit 402.

[0284] The communication apparatus 40 can be the second node or a chip in the second node. When the communication apparatus 40 is configured to implement the functions of the second node in the above embodiments, each unit is configured to implement the following functions.

[0285] The sending unit 401 is configured to send a path measurement report.

[0286] In some embodiments, the sending unit 401 is configured to generate a path measurement report based on a first measurement event, and send the path measurement report.

[0287] In some embodiments, the receiving unit 402 is configured to receive first configuration information from the first node. The first configuration information is used to configure at least one of a content of the first measurement event or a content of the path measurement report.

[0288] In some embodiments, the receiving unit 402 is configured to receive switching configuration of a target path from the first node.

[0289] In some embodiments, the sending unit 401 is further configured to send capability information related to multi-hop relay communication to the first node.

[0290] In some embodiments, the receiving unit 402 is configured to receive second indication information from the fourth node. The fourth node is the first relay node in the source path of the second node, and the second indication information includes at least one of:

[0291] a link quality between the fourth node and a parent node of the fourth node;

[0292] a link quality between an intermediate relay node in the source path and a parent node of the intermediate relay node;

[0293] indication information used to indicate that the link quality between the intermediate relay node in the source path and the parent node of the intermediate relay node deteriorates or an SL RLF occurs;

[0294] a Uu interface link state information of a last relay node in the source path; or

[0295] PC5 radio resource control information.

[0296] The PC5 RRC information includes at least one of the following: a node identifier of the parent node of the fourth node, the link quality between the fourth node and the parent node of the fourth node, the third indication information, the SL RLF, or an identifier of the intermediate relay node in the source path. The third indication information is used to indicate that the link quality between the fourth node and the parent node of the fourth node is less than or equal to a fourth threshold value.

[0297] It should be noted that the units in FIG. 8 or FIG. 9 can also be referred to as modules, for example, the sending unit can be referred to as a sending module. In addition, in the embodiments shown in FIG. 8 or FIG. 9, the names of the various units can also be different from those shown in the figure, for example, the sending unit can also be referred to as a communication unit, and the receiving unit can also be referred to as a communication unit.

[0298] If each unit in FIG. 8 or FIG. 9 is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present disclosure or the part that contributes to the related art or the whole or part 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.) or a processor (Processor) to execute all or part of the steps of the embodiments of the present disclosure. The storage medium storing the computer software product includes a U disk, a mobile hard disk, a read-only memory (Read-only Memory, ROM), a random access memory (Random Access Memory, RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0299] In the case that the communication device 30 or the communication device 40 implements the functions of the above-mentioned integrated modules in the form of hardware, some embodiments of the present disclosure further provide a communication device. As shown in FIG. 10, the communication device 50 includes a processor 502, a communication interface 503, and a bus 504. For example, the communication device 50 can further include a memory 501.

[0300] The processor 502 can be a central processing unit, a general purpose processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array, or other programmable logic device, transistor logic, hardware components, or any combination thereof. The processor 502 can implement or execute the various exemplary logical blocks, modules, and circuits described in conjunction with the disclosure. The processor 502 can also be a combination of implementing computing functions, such as a combination of one or more microprocessors, a combination of a digital signal processor (DSP) and a microprocessor, and the like.

[0301] The communication interface 503 is used to connect with other devices through a communication network. The communication network can be an Ethernet, a wireless access network, a wireless local area network (WLAN), and the like.

[0302] The memory 501 can be a read-only memory or other type of static storage device that can store static information and instructions, a random access memory or other type of dynamic storage device that can store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program codes in the form of instructions or data structures and can be accessed by a computer, but the present disclosure is not limited thereto.

[0303] In some embodiments, the memory 501 can exist independently of the processor 502. The memory 501 can be connected to the processor 502 through the bus 504 for storing instructions or program codes. When the processor 502 invokes and executes the instructions or program codes stored in the memory 501, the path switching method provided by some embodiments of the present disclosure can be implemented.

[0304] In some embodiments, the memory 501 can also be integrated with the processor 502.

[0305] The bus 504 can be an Extended Industry Standard Architecture (EISA) bus or the like. The bus 504 can be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, only one thick line is shown in FIG. 10, but this does not mean that there is only one bus or only one type of bus.

[0306] Through the above description of the embodiments, those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above functional modules is exemplified, and in actual application, the above functions can be completed by different functional modules according to needs, that is, the internal structure of the first node or the second node is divided into different functional modules to complete all or part of the functions described above.

[0307] Some embodiments of the present disclosure also provide a computer-readable storage medium. All or part of the processes of the above method embodiments can be instructed by computer program instructions to complete related hardware, and the computer program instructions can be stored in the above computer-readable storage medium. When the computer program instructions are executed, the processes of the above method embodiments can be included. The above computer-readable storage medium can also be an external storage device of the above first node or second node, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, and the like. Further, the above computer-readable storage medium can include both the internal storage unit of the above first node or second node and the external storage device. The above computer-readable storage medium is used to store the above computer program instructions and other programs and data required by the above first node or second node. The above computer-readable storage medium can also be used to temporarily store data that has been output or will be output.

[0308] Some embodiments of the present disclosure also provide a computer program product containing a computer program. When the computer program product runs on a computer, it makes the computer execute any one of the path switching methods provided in the above embodiments.

[0309] Although the present disclosure is described in conjunction with various embodiments, it will be understood that many of the described embodiments are not mutually exclusive, and that specific characteristics or embodiments described can be implemented in various combinations with each other. It will be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure without departing from the spirit or scope of the disclosure. Thus, it is intended that the present disclosure cover the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents. It is therefore intended that the present disclosure not be limited to the specific illustrative embodiments disclosed, but rather, cover all modifications and variations that come within the scope of the present disclosure.

[0310] Although the present disclosure is described in conjunction with various embodiments, it will be understood that many of the described embodiments are not mutually exclusive, and that specific characteristics or embodiments described can be implemented in various combinations with each other. It will be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure without departing from the spirit or scope of the disclosure. Thus, it is intended that the present disclosure cover the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents. It is therefore intended that the present disclosure not be limited to the specific illustrative embodiments disclosed, but rather, cover all modifications and variations that come within the scope of the present disclosure.

[0311] The above merely provides specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and any changes or replacements within the technical scope disclosed by the present disclosure should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. A path switching method applied to a first node, the method comprising: receiving a path measurement report; and making a decision on path switching of a second node based on the path measurement report. The receiving the path measurement report comprises: receiving the path measurement report reported by the second node based on a first measurement event. The first measurement event is related to a type of at least one of a source path or a candidate path of the second node. The first measurement event comprises at least one of: detecting that a link quality between the second node and a first relay node in the source path is less than or equal to a first threshold value, and detecting that a link quality of a direct path between the second node and the first node is greater than or equal to a second threshold value; detecting that the link quality between the second node and the first relay node in the source path is less than or equal to a third threshold value; receiving first indication information indicating that a target link in the source path has a deteriorated link quality or is less than or equal to a fourth threshold value; a link quality of a relay node other than the first relay node in the source path is less than or equal to a fifth threshold value; or detecting that there is a candidate path with a relay hop count less than or equal to a target hop count, and a link quality between the second node and a first relay node in the candidate path is greater than or equal to a sixth threshold value, wherein the target hop count is a relay hop count of the source path or a preset value.

2. The method of claim 1, wherein, 5.The method of claim 2, further comprising: sending first configuration information to the second node, the first configuration information being used to configure at least one of a content of the first measurement event or a content of the path measurement report. The path measurement report comprises at least one of: measurement information of a source path or measurement information of a candidate path.

3. The method of claim 2, wherein, The source path is a relay path, and the candidate path comprises a direct path and the relay path; or the source path is the direct path, and the candidate path comprises the relay path.

4. The method of claim 2, wherein, The relay path comprises a single-hop relay path and a multi-hop relay path. The candidate path is a multi-hop relay path, and the measurement information of the candidate path comprises at least one of: a node identifier of a first relay node in the candidate path; a link quality between the first relay node in the candidate path and the second node; a node identifier of a last relay node in the candidate path; a cell identifier of the last relay node in the candidate path; a relay hop count of the candidate path; a node identifier of an intermediate relay node of the candidate path; or a link quality between a relay node in the candidate path and a previous node of the relay node. The relay hop count of the candidate path is less than or equal to a preset value, and the preset value is configured by the first node. 10.The method of claim 1, further comprising: sending second configuration information to a relay node in a source path of the second node, wherein the second configuration information is used to configure a second measurement event, and the second measurement event is detecting that a link quality of a link related to the relay node is less than or equal to a fourth threshold value. The receiving the path measurement report comprises: ​ ​ ​ ​ 6. The method of claim 2, wherein, ​ 7. The method of claim 3, wherein, ​ ​ ​ 8. The method of claim 6, wherein, ​ ​ ​ ​ ​ ​ ​ ​ 9. The method of claim 8, wherein, ​ ​ ​ 11. The method of claim 1, wherein, ​ receive a path measurement report reported by a third node based on a third measurement event; wherein the third node is a last relay node in a source path of the second node.

12. The method of claim 11, wherein, The path measurement report comprises at least one of a node identifier of the second node or a link quality between the third node and the second node.

13. The method of claim 11, wherein, The third measurement event comprises detecting that a signal receiving power of the second node is greater than or equal to a seventh threshold.

14. The method of claim 11, further comprising: sending third configuration information to the third node; wherein the third configuration information is used to configure at least one of a content of the third measurement event or a content of the path measurement report.

15. The method of claim 1, further comprising: sending a handover configuration of a target path to the second node.

16. The method of claim 15, wherein, The handover configuration of the target path comprises at least one of a sequence number of the target path, path information of the target path, a relay hop number of the target path, or a path handover timer configuration.

17. The method of claim 1, further comprising: sending configuration information of the target path to a relay node in the target path.

18. The method of claim 17, wherein, for a first relay node in the target path, the configuration information of the target path comprises at least one of a mapping relationship between a Uu bearer of the second node and an uplink PC5 Radio Link Control (RLC) channel, a mapping relationship between the Uu bearer of the second node and a downlink PC5 RLC channel, a mapping relationship between an uplink ingress RLC channel and an egress RLC channel, or a mapping relationship between a downlink ingress RLC channel and an egress RLC channel; for a last relay node in the target path, the configuration information of the target path comprises at least one of a node identifier of the second node, a local identifier of the second node, a node identifier of the first relay node in the target path, downlink routing information, node identifiers of each relay node in the target path, a mapping relationship between the Uu bearer of the second node and a PC5 RLC channel, or a mapping relationship between the Uu bearer of the second node and a Uu RLC channel; for an intermediate relay node in the target path, the configuration information of the target path comprises at least one of a mapping relationship between the Uu bearer of the second node and the uplink PC5 RLC channel, a mapping relationship between the Uu bearer of the second node and the downlink PC5 RLC channel, the downlink routing information, a mapping relationship between the uplink ingress RLC channel and the egress RLC channel, or a mapping relationship between the downlink ingress RLC channel and the egress RLC channel.

19. The method of claim 18, wherein, The downlink routing information comprises node identifiers of downstream relay nodes of the last relay node, which are reachable to the second node.

20. The method of claim 1, further comprising: receiving, from the second node, multi-hop relay communication related capability information.

21. The method of claim 20, wherein, The multi-hop relay communication related capability information comprises at least one of: a capability of supporting connection to the first node through a multi-hop relay path; a capability of supporting path switching to the multi-hop relay path; a frequency list supporting multi-hop relay communication; a frequency band combination supporting the multi-hop relay communication; a capability of supporting connection to the first node through a Layer 2 User Equipment to Network Relay (L2 U2N relay) multi-hop relay path; or a capability of supporting switching to the L2 U2N relay.

22. The method of claim 1, further comprising: receiving, from the second node, node type information; and based on the node type information, determining whether the second node is capable of acting as a node type corresponding to the node type information.

23. The method of claim 1, further comprising: receiving, from a core network network element, multi-hop relay communication related authorization information; wherein the authorization information comprises at least one of: authorization information authorizing acting as a remote node of a multi-hop L2 U2N; authorization information authorizing performing a remote operation of the multi-hop L2 U2N; authorization information authorizing acting as an intermediate relay node of the multi-hop L2 U2N; authorization information authorizing performing an intermediate relay operation of the multi-hop L2 U2N; authorization information authorizing acting as a root relay node of the multi-hop L2 U2N; or authorization information authorizing performing a root relay operation of the multi-hop L2 U2N.

24. A path switching method applied to a second node, the method comprising: sending a path measurement report. The sending of the path measurement report comprises:

25. The method of claim 24, wherein, generating the path measurement report based on a first measurement event; and sending the path measurement report. The first measurement event is related to a type of at least one of a source path or a candidate path of the second node.

26. The method of claim 25, wherein, The first measurement event comprises at least one of:

27. The method of claim 25, wherein, detecting that a link quality between the second node and a first relay node in a source path is less than or equal to a first threshold value, and detecting that a link quality of a direct connection path between the second node and a first node is greater than or equal to a second threshold value; detecting that a link quality between the second node and the first relay node in the source path is less than or equal to a third threshold value; receiving first indication information indicating that a target link in the source path has deteriorated or is less than or equal to a fourth threshold value; a link quality of a non-first relay node in the source path is less than or equal to a fifth threshold value; or detecting that there is a candidate path having a relay hop count less than or equal to a target hop count, and a link quality between the second node and a first relay node in the candidate path is greater than or equal to a sixth threshold value; wherein the target hop count is a relay hop count of the source path or a preset value.

28. The method of claim 25, further comprising: ​ ​ receive first configuration information from a first node; wherein the first configuration information is used to configure at least one of a content of the first measurement event or a content of the path measurement report.

29. The method of claim 28, wherein, The path measurement report comprises at least one of: measurement information of a source path or measurement information of a candidate path.

30. The method of claim 26, wherein, The source path is a relay path, and the candidate path comprises a direct path and the relay path; or, The source path is the direct path, and the candidate path comprises the relay path; The relay path comprises a single-hop relay path and a multi-hop relay path.

31. The method of claim 29, wherein, The candidate path is a multi-hop relay path, and the measurement information of the candidate path comprises at least one of: a node identifier of a first relay node in the candidate path; a link quality between the first relay node and a next node of the first relay node in the candidate path; a node identifier of a last relay node in the candidate path; a cell identifier of the last relay node in the candidate path; a relay hop number of the candidate path; a node identifier of an intermediate relay node of the candidate path; or a link quality between a relay node and a next node of the relay node in the candidate path.

32. The method of claim 31, wherein, The relay hop number of the candidate path is less than or equal to a preset value, and the preset value is configured by the first node.

33. The method of claim 24, further comprising: receiving a handover configuration of a target path from a first node.

34. The method of claim 33, wherein, The handover configuration of the target path comprises at least one of: a sequence number of the target path, path information of the target path, a relay hop number of the target path, or a path handover timer configuration.

35. The method of claim 24, further comprising: sending, to a first node, multi-hop relay communication related capability information.

36. The method of claim 35, wherein, The multi-hop relay communication related capability information comprises at least one of: a capability of connecting to the first node through a multi-hop relay path; a capability of handover to the multi-hop relay path; a frequency list supporting multi-hop relay communication; a frequency band combination supporting the multi-hop relay communication; a capability of connecting to the first node through a multi-hop relay path of L2 U2N relay; or a capability of handover to L2 U2N relay.

37. The method of claim 24, further comprising: receiving second indication information from a fourth node; wherein the fourth node is a first relay node in a source path of the second node, and the second indication information comprises at least one of: a link quality between the fourth node and a next node of the fourth node; a link quality between an intermediate relay node and a next node of the intermediate relay node in the source path; indication information indicating that a link quality between the intermediate relay node and the next node of the intermediate relay node in the source path deteriorates or a Sidelink (SL) Radio Link Failure (RLF) occurs; Uu interface link state information of a last relay node in the source path; or ​ PC5 RRC information; wherein the PC5 RRC information comprises at least one of: a node identifier of a parent node of the fourth node, a link quality between the fourth node and the parent node of the fourth node, third indication information, a SL RLF, or an identifier of the intermediate relay node in the source path; wherein the third indication information is used to indicate that the link quality between the fourth node and the parent node of the fourth node is less than or equal to a fourth threshold.

38. A communications device comprising: a memory and a processor; the memory and the processor are coupled; the memory is configured to store instructions executable by the processor; the processor executes the instructions to perform the method according to any one of claims 1 to 37.

39. A computer readable storage medium, wherein, The computer readable storage medium has stored thereon computer instructions which, when executed on a computer, cause the computer to perform the method according to any one of claims 1 to 37.

40. A computer program product, wherein, The computer program product contains computer instructions which, when executed on a computer, cause the computer to perform the method according to any one of claims 1 to 37.

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