SL multi-path establishment method, and terminal, network-side device, chip and medium

Abstract

The present application belongs to the technical field of communications. Disclosed are an SL multi-path establishment method, and a terminal, a network-side device, a chip and a medium. The SL multi-path establishment method in the embodiments of the present application comprises: a remote UE receiving a first configuration, which is sent by a first network node by means of a first communication link, wherein the first communication link is a communication link between the remote UE and the first network node, and the first configuration is used for establishing a second communication link between the remote UE and a second network node; and the remote UE establishing the second communication link on the basis of the first configuration, wherein the communication link is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link.

Description

SL multi-path establishment method, terminal, network side equipment, chip and medium

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application number 202310982074.9 filed in China on August 4, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application belongs to the field of communication technology, and specifically relates to a side link (SL) multi-path establishment method, terminal, network-side equipment, chip and medium. Background Art

[0004] Currently, User Equipment (UE) can directly establish a communication path with a network device, i.e., a direct path of the UE; or, the UE can establish a communication link with a network device through a relay UE, i.e., an indirect path of the UE.

[0005] In some cases, a UE may need to transmit data via both direct and indirect paths, meaning it needs to transmit data via multiple paths. However, the related art does not provide a solution for establishing multiple paths for UEs, so implementing multiple paths for UEs is an urgent problem to be solved.

[0006] Summary of the Invention

[0007] The embodiments of the present application provide a SL multi-path establishment method, terminal, network-side equipment, chip and medium, which can solve the problem of multi-path establishment of UE.

[0008] In a first aspect, a SL multi-path establishment method is provided, which is executed by a remote UE, and the method includes: a remote user equipment UE receives a first configuration sent by a first network node through a first communication link, wherein the first communication link is a communication link between the remote UE and the first network node, and the first configuration is used to establish a second communication link between the remote UE and a second network node; the remote UE establishes the second communication link based on the first configuration; wherein the communication link is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link.

[0009] In the second aspect, a SL multi-path establishment method is provided, which is executed by a first network node, and the method includes: the first network node sends a first configuration to a remote UE through a first communication link, wherein the first communication link is a communication link between the remote UE and the first network node, and the first configuration is used to establish a second communication link between the remote UE and the second network node; wherein the communication link is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link.

[0010] In the third aspect, a SL multi-path establishment method is provided, which is executed by a second network node, and the method includes: the second network node sends a first configuration, and the first configuration is used to establish a second communication link between a remote UE and the second network node; the second communication link is different from the first communication link of the remote UE; the first communication link is the communication link between the remote UE and the first network node, and the first communication link is used by the first network node to send the first configuration to the remote UE; wherein, the communication link is a direct link or an indirect link of the remote UE.

[0011] In a fourth aspect, a SL multi-path establishment device is provided, which includes: a receiving module and an establishment module; the receiving module is used to receive a first configuration sent by a first network node through a first communication link, the first communication link is a communication link between the remote UE and the first network node, and the first configuration is used to establish a second communication link between the remote UE and the second network node; the establishment module is used to establish the second communication link based on the first configuration received by the receiving module; wherein the communication link is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link.

[0012] In a fifth aspect, a SL multi-path establishment device is provided, the SL multi-path establishment device including: a sending module;

[0013] The sending module is configured to send a first configuration to a remote UE via a first communication link, where the first communication link is a communication link between the remote UE and a first network node, and the first configuration is used to establish a second communication link between the remote UE and a second network node; wherein the communication link is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link.

[0014] In the sixth aspect, a SL multi-path establishment device is provided, which includes: a sending module; the sending module is used to send a first configuration, and the first configuration is used to establish a second communication link between the remote UE and the second network node; the second communication link is different from the first communication link of the remote UE; the first communication link is the communication link between the remote UE and the first network node, and the first communication link is used by the first network node to send the first configuration to the remote UE; wherein, the communication link is a direct link or an indirect link of the remote UE.

[0015] In a seventh aspect, a terminal is provided, comprising a processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the steps of the method described in the first aspect are implemented.

[0016] In an eighth aspect, a terminal is provided, comprising a processor and a communication interface, wherein the communication interface is used to receive a first configuration sent by a first network node via a first communication link, the first communication link being a communication link between the remote UE and the first network node, and the first configuration being used to establish a second communication link between the remote UE and the second network node; the processor is used to establish the second communication link based on the first configuration received by the communication interface; wherein the communication link is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link.

[0017] In the ninth aspect, a network side device is provided, which includes a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the program or instructions are executed by the processor, the steps of the method described in the second aspect are implemented.

[0018] In the tenth aspect, a network side device is provided, comprising a processor and a communication interface, wherein the communication interface is used to send a first configuration to a remote UE through a first communication link, wherein the first communication link is a communication link between the remote UE and a first network node, and the first configuration is used to establish a second communication link between the remote UE and a second network node; wherein the communication link is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link.

[0019] In the eleventh aspect, a network side device is provided, which includes a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the program or instructions are executed by the processor, the steps of the method described in the third aspect are implemented.

[0020] In the twelfth aspect, a network side device is provided, including a processor and a communication interface, wherein the communication interface is used to send a first configuration, and the first configuration is used to establish a second communication link between a remote UE and a second network node; the second communication link is different from the first communication link of the remote UE; the first communication link is the communication link between the remote UE and the first network node, and the first communication link is used by the first network node to send the first configuration to the remote UE; wherein the communication link is a direct link or an indirect link of the remote UE.

[0021] In the thirteenth aspect, a readable storage medium is provided, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the method described in the first aspect are implemented, or the steps of the method described in the second aspect are implemented, or the steps of the method described in the third aspect are implemented.

[0022] In the fourteenth aspect, a communication system is provided, comprising: the SL multi-link establishment device as described in the fourth, fifth and sixth aspects above; or, comprising the terminal as described in the eighth aspect above, and the network side equipment as described in the tenth and twelfth aspects.

[0023] In the fifteenth aspect, a chip is provided, which includes a processor and a communication interface, the communication interface and the processor are coupled, and the processor is used to run programs or instructions to implement the method as described in the first aspect, or the method as described in the second aspect, or the method as described in the third aspect.

[0024] In the sixteenth aspect, a computer program / program product is provided, which is stored in a storage medium, and the program / program product is executed by at least one processor to implement the method as described in the first aspect, or the method as described in the second aspect, or the steps of the method as described in the third aspect.

[0025] In an embodiment of the present application, a remote UE receives a first configuration sent by a first network node through a first communication link, wherein the first communication link is a communication link between the remote UE and the first network node, and the first configuration is used to establish a second communication link between the remote UE and a second network node; the remote UE establishes the second communication link based on the first configuration; wherein the communication link is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link. Through this solution, since the remote UE can receive the link configuration of the second communication link that the remote UE has not established through the first communication link that the remote UE already has, the remote UE can quickly establish the second communication link based on the link configuration of the second communication link when the remote UE has one communication link. In this way, multi-path establishment of the remote UE can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG1 is a schematic diagram of an architecture of a communication system provided in an embodiment of the present application;

[0027] FIG2 is a schematic diagram of an SL architecture provided in an embodiment of the present application;

[0028] FIG3 is a schematic diagram of a multipath architecture in related art;

[0029] FIG4 is a flow chart of a method for establishing a SL multi-path according to an embodiment of the present application;

[0030] FIG5 is one of the schematic diagrams of the architecture of establishing SL multipath provided in an embodiment of the present application;

[0031] FIG6 is a second schematic diagram of the architecture of establishing SL multipath provided in an embodiment of the present application;

[0032] FIG7 is a third schematic diagram of the architecture of SL multi-path establishment provided in an embodiment of the present application;

[0033] FIG8 is a second flow chart of a method for establishing a SL multi-path according to an embodiment of the present application;

[0034] FIG9 is a third flow chart of a method for establishing a SL multi-path according to an embodiment of the present application;

[0035] FIG10 is a fourth flow chart of a method for establishing a SL multi-path according to an embodiment of the present application;

[0036] FIG11 is a flowchart of a fifth SL multi-path establishment method provided in an embodiment of the present application;

[0037] FIG12 is a sixth flow chart of a method for establishing a SL multi-path according to an embodiment of the present application;

[0038] FIG13 is a flowchart of a method for establishing a SL multi-path according to an embodiment of the present application;

[0039] FIG14 is a schematic diagram of a structure of an SL multi-path establishment device according to an embodiment of the present application;

[0040] FIG15 is a second structural diagram of an SL multi-path establishment device provided in an embodiment of the present application;

[0041] FIG16 is a third structural diagram of an SL multi-path establishment device provided in an embodiment of the present application;

[0042] FIG17 is a schematic diagram of a structure of a terminal provided in an embodiment of the present application;

[0043] FIG18 is a second structural diagram of a terminal provided in an embodiment of the present application;

[0044] FIG19 is a schematic structural diagram of a network-side device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0045] The following will be combined with the accompanying drawings in the embodiments of this application to clearly describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0046] The terms "first", "second", etc. in this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same type, and do not limit the number of objects, for example, the first object can be one or more. In addition, "or" in this application represents at least one of the connected objects. For example, "A or B" covers three options, namely, Option 1: including A but not including B; Option 2: including B but not including A; Option 3: including both A and B. The character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0047] The term "indication" in this application can be either a direct indication (or explicit indication) or an indirect indication (or implicit indication). A direct indication can be understood as the sender explicitly informing the receiver of specific information, the operation to be performed, or the requested result, etc. in the instruction sent; an indirect indication can be understood as the receiver determining the corresponding information based on the instruction sent by the sender, or making a judgment and determining the operation to be performed or the requested result, etc. based on the judgment result.

[0048] It is worth noting that the technology described in the embodiments of the present application is not limited to the Long Term Evolution (LTE) / LTE-Advanced (LTE-A) system, but can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency-Division Multiple Access (SC-FDMA) or other systems. The terms "system" and "network" in the embodiments of the present application are often used interchangeably, and the technology described can be used for the systems and radio technologies mentioned above, as well as for other systems and radio technologies. The following description describes a New Radio (NR) system for illustrative purposes, and NR terminology is used in most of the following description, but these technologies can also be applied to systems other than NR systems, such as 6th generation (6G) systems. th Generation, 6G) communication system.

[0049] FIG1 is a block diagram of a wireless communication system applicable to an embodiment of the present application. The wireless communication system includes a terminal 11 and a network-side device 12. The terminal 11 may be a mobile phone, a tablet computer (Tablet Personal Computer), a laptop computer (Laptop Computer), a notebook computer, a personal digital assistant (PDA), a handheld computer, a netbook, an ultra-mobile personal computer (UMPC), a mobile internet device (MID), an augmented reality (AR), a virtual reality (VR) device, a robot, a wearable device (Wearable Device), an aircraft (Flight Vehicle), a vehicle-mounted device (VUE), a ship-mounted device, a pedestrian user equipment (PUE), a smart home (home appliances with wireless communication capabilities, such as refrigerators, televisions, washing machines, or furniture), a game console, a personal computer (PC), an ATM, or a self-service machine, or other terminal-side devices. Wearable devices include: smart watches, smart bracelets, smart headphones, smart glasses, smart jewelry (smart bracelets, smart bracelets, smart rings, smart necklaces, smart anklets, smart anklets, etc.), smart wristbands, smart clothing, etc. Among them, the vehicle-mounted device can also be called a vehicle-mounted terminal, a vehicle-mounted controller, a vehicle-mounted module, a vehicle-mounted component, a vehicle-mounted chip or a vehicle-mounted unit, etc. It should be noted that the specific type of the terminal 11 is not limited in the embodiment of the present application. The network side device 12 may include an access network device or a core network device, wherein the access network device may also be called a radio access network (Radio Access Network, RAN) device, a radio access network function or a radio access network unit. The access network device may include a base station, a wireless local area network (WLAN) access point (AS) or a wireless fidelity (WiFi) node, etc.Among them, the base station can be referred to as Node B (NB), Evolved Node B (eNB), the next generation Node B (gNB), New Radio Node B (NR Node B), access point, Relay Base Station (RBS), Serving Base Station (SBS), Base Transceiver Station (BTS), radio base station, radio transceiver, Basic Service Set (BSS), Extended Service Set (ESS), Home Node B (HNB), Home Evolved Node B (home evolved Node B), Transmission Reception Point (TRP) or other appropriate terms in the field. As long as the same technical effect is achieved, the base station is not limited to specific technical vocabulary. It should be noted that in the embodiment of the present application, only the base station in the NR system is used as an example for introduction, and the specific type of the base station is not limited.

[0050] The following is an explanation of the nouns and terms involved in the description and claims of this application.

[0051] 1. Sidelink Relay Mechanism

[0052] Relay technology in wireless communication systems adds one or more relay nodes between the base station and the terminal, which is responsible for forwarding the wireless signal once or multiple times. That is, the wireless signal has to go through multiple hops before reaching the terminal.

[0053] Wireless relay technology not only expands cell coverage and fills blind spots, but also increases cell capacity through spatial resource reuse. For indoor coverage, relay technology can also overcome penetration loss and improve indoor coverage quality.

[0054] Taking a simple two-hop relay as an example, wireless relay splits a base station-terminal link into two links: base station-relay station and relay station-terminal. This allows one poor-quality link to be replaced with two high-quality links, achieving higher link capacity and better coverage.

[0055] Currently, the relay supported in LTE is a UE-to-network relay, where one end of the relay is connected to the UE and the other end is connected to the network. The UE connected to the relay is called a remote UE.

[0056] NR will also study how to support the UE-to-Network Relay mechanism. A typical scenario is shown in Figure 2:

[0057] Figure 2 shows a typical UE-to-network scenario. A remote UE needs to transmit data to the network, but due to poor coverage, it uses a relay UE to relay the data. The Uu interface connects the relay UE to the base station, while the SL interface, such as the PC5 interface, connects the relay UE to the remote UE. Generally speaking, the relay UE is open and can serve any remote UE.

[0058] 2. Indirect path: Also known as an indirect path, it refers to the wireless link established between the Remote UE (or Primary UE) and the base station through the Relay UE (or Secondary UE) and the Uu interface of the Relay UE (or Secondary UE).

[0059] 3. Direct path: Direct path refers to the wireless link established between the Remote UE (or Primary UE) and the base station through its own Uu interface air interface.

[0060] 4. Multipath scenario definition

[0061] For the SL relay architecture, multipath means that the Remote UE establishes both an indirect path and a direct path.

[0062] In the related art, a multipath scenario is that a UE is within the coverage of the same base station and establishes both a direct link and an indirect link with the base station, as shown in FIG3 .

[0063] 5. Radio Bearer (RB) is a general term for different layer protocol entities and configurations allocated by network nodes, such as base stations, to UEs. It includes a series of resources such as PDCP protocol entity, RLC protocol entity, MAC protocol entity, and PHY protocol entity.

[0064] There are two types of RBs: Signaling Radio Bearer (SRB) and Data Radio Bearer (DRB).

[0065] Optionally, the SRB includes at least one of the following: SRB1 and SRB3;

[0066] For RRC messages (which may include piggybacked NAS messages) and for NAS messages before SRB2 is established, all using the DCCH logical channel;

[0067] SRB3 is used for specific RRC messages when the UE is in (NG)EN-DC (EUTRA-NR Dual Connection) or NR-DC, all using the DCCH logical channel.

[0068] Below, in combination with the accompanying drawings, the SL multi-path establishment method, UE, network node, chip and medium provided in the embodiments of the present application are described in detail through some embodiments and their application scenarios.

[0069] The SL multi-path establishment method provided in the embodiments of the present application can be applied to the following three scenarios.

[0070] In the related art, the R18 side link (SL) relay architecture can support remote user equipment (UE) to establish a direct link and an indirect link, that is, to form a multi-path communication architecture, so that the remote UE can use two paths for network communication.

[0071] Specifically, the remote UE establishes a direct path and an indirect path under the same access network node. For example, both paths established by the remote UE are under the control of a next-generation access network Node B (gNB), i.e., an intra-gNB, so that the remote UE can communicate with the gNB through the direct path and the indirect path.

[0072] In this way, since the SL relay architecture of the related technology supports the remote UE to establish multiple paths under the same access network node, there is no solution to establish multiple paths across access network nodes. Therefore, how to enable the remote UE to establish multiple paths across access network nodes in the SL relay architecture is an urgent problem to be solved.

[0073] Scenario 1: The remote UE establishes multiple paths across different access network nodes.

[0074] Exemplarily, in the SL multi-path establishment method provided in an embodiment of the present application, the remote UE can receive a first configuration sent by an access network node through a first communication link, where the first configuration is a link configuration of a second communication link between the remote UE and another access network node; the remote UE establishes a second communication link based on the first configuration; wherein the communication link is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link. In this way, since the remote UE can receive a link configuration of a second communication link that the remote UE has not established through a first communication link that the remote UE already has, a network node sends the link configuration of a second communication link that the remote UE has not established to the remote UE, thereby quickly establishing the second communication link based on the link configuration of the second communication link when the UE has one communication link. In this way, multi-path establishment of the remote UE across access network nodes can be achieved.

[0075] Scenario 2: The remote UE establishes multiple paths across different Distributed Units (DUs) in one access network node.

[0076] Exemplarily, in the SL multi-path establishment method provided in an embodiment of the present application, the remote UE can receive a first configuration sent by the first access network node through the first communication link, where the first configuration is the link configuration of the second communication link between the remote UE and the second access network node; the remote UE establishes a second communication link based on the first configuration; wherein the communication link is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link. In this way, since the remote UE can receive the link configuration of the second communication link that the remote UE has not established through the first communication link that the remote UE already has, the remote UE can quickly establish the second communication link based on the link configuration of the second communication link when the UE has one communication link. In this way, multi-path establishment of the remote UE across access network nodes can be achieved.

[0077] Scenario 3: The remote UE establishes multiple paths across Centralized Units (CUs) in different access network nodes.

[0078] Exemplarily, in the SL multi-path establishment method provided in an embodiment of the present application, the remote UE can receive a first configuration sent by a CU in an access network node through a DU in the access network node (i.e., a DU that can be included in the first communication link), and the first configuration is the link configuration of the second communication link between the remote UE and the CU, such as a communication link that can include the remote UE-another DU in the access network node-the CU; the remote UE establishes the second communication link based on the first configuration; wherein the communication link is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link. In this way, since the remote UE can receive the link configuration of the second communication link that the remote UE has not established through the first communication link that the remote UE already has, the remote UE can send the link configuration of the second communication link that the remote UE has not established to the remote UE, thereby quickly establishing the second communication link based on the link configuration of the second communication link when the UE has one communication link. In this way, multi-path establishment of the remote UE across DUs can be achieved.

[0079] An embodiment of the present application provides a SL multi-path establishment method. Figure 4 shows a flowchart of the SL multi-path establishment method provided by the embodiment of the present application. As shown in Figure 4, the SL multi-path establishment method provided by the embodiment of the present application may include the following steps 401 and 402.

[0080] Step 401: A remote UE receives a first configuration sent by a first network node through a first communication link.

[0081] The first communication link is a communication link between a remote UE and a first network node, and the first configuration may be used to establish a second communication link between the remote UE and a second network node.

[0082] The communication link is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link.

[0083] For example, the first communication link is a direct link of the remote UE, and the second communication link is an indirect link of the remote UE.

[0084] For another example, the first communication link is an indirect link of the remote UE, and the second communication link is a direct link of the remote UE.

[0085] Optionally, the indirect link of the remote UE may be referred to as an indirect path of the remote UE, and the direct link of the remote UE may be referred to as a direct path of the remote UE.

[0086] It can be understood that the first communication link is a link that the remote UE already has, that is, the first communication link is a communication link that the remote UE has successfully established; the second communication link is a communication link that the remote UE has not yet established.

[0087] Optionally, the remote UE may perform data transmission with the network side via the first communication link.

[0088] In an embodiment of the present application, scenario 1: the first network node and the second network node are different access network nodes; or, scenario 2: the first network node is a first centralized unit (CU), and the second network node is a second CU; or, scenario 3: the first network node and the second network node are both third CUs.

[0089] Optionally, the first CU and the second CU are CUs in different access network nodes.

[0090] Optionally, Figure 5 illustrates a typical multi-path communication architecture across access network nodes (e.g., inter-gNB multi-path) involved in Scenario 1, hereinafter referred to as Communication Architecture 1. In Communication Architecture 1, a remote UE can establish a direct link with Access Network Node 1 and can also establish an indirect path with the Access Network Node via a relay UE. It will be appreciated that in Scenario 1, since the remote UE establishes a multi-path across two Access Network Nodes, the process for establishing the second communication link and the details of the information carried will differ significantly from the related art in which a link with the remote UE is established within a single Access Network Node.

[0091] Optionally, in Scenario 2, the access network nodes are split into a CU-DU architecture, and the remote UE's service DU and the relay UE's service DU belong to different access network nodes. That is, the remote UE's service DU and the relay UE's service DU are located in different CUs. Figure 6 shows a typical multipath communication architecture across DUs and CUs involved in Scenario 2, hereinafter referred to as Communication Architecture 2. In Communication Architecture 2, the remote UE can establish a direct link with CU1 via DU1 and an indirect path with CU1 via the relay UE and DU2.

[0092] Optionally, in FIG6 , DU1 and DU2 are serving DUs of a remote UE and a relay UE, respectively.

[0093] It should be noted that in scenario 2, the signaling process for the remote UE to establish the second communication link involves not only signaling interaction between the CU-DU interfaces, but also signaling interaction between CUs, such as the Xn interface.

[0094] Optionally, in scenario 3, the access network node is split into a CU-DU architecture. Figure 7 shows a typical cross-DU multi-path (such as inter-DU indirect link) communication architecture involved in scenario 3, hereinafter referred to as communication architecture 3. Since the access network node is split into a CU-DU architecture, the second communication link of the remote UE, such as the addition of a second communication link, will have an impact on the interface process between the CU-DU. However, whether the access network node is split into a CU-DU structure does not affect the behavior of the UE in principle, and can be transparent to the UE. Among them, in communication architecture 3, the remote UE can establish a direct link with the CU through DU1, and can establish an indirect path with the CU through the relay UE and the relay UE's DU2.

[0095] Optionally, in FIG7 , DU1 and DU2 are serving DUs of a remote UE and a relay UE, respectively.

[0096] Optionally, the first configuration may include at least one of the following:

[0097] End-to-end E2E bearer configuration of the remote UE at the second network node;

[0098] Transmission configuration of the remote UE on the PC5 interface;

[0099] Transmission configuration of the remote UE on the Uu interface;

[0100] The basic configuration of the remote UE may include at least one of the cell information and relay UE information configured by the second network node for the remote UE.

[0101] Optionally, the transmission configuration of the remote UE on the PC5 interface refers to the transmission configuration of the Remote UE bearer on the PC5 interface. For example, it may include mapping information of the Remote UE RB identifier to the Remote UE PC5 interface Radio Link Control (RLC) bearer, Remote UE PC5 interface RLC bearer information, etc.

[0102] Optionally, the cell information configured by the second network node for the remote UE may include at least one of the following: serving cell information configured by the second network node for the remote UE, and primary cell (Pcell) information configured by the second network node for the remote UE.

[0103] Optionally, the relay UE information configured by the second network node for the remote UE may include: a relay UE layer 2 (Layer 2, L2) identifier configured by the second network node for the remote UE.

[0104] Step 402: The remote UE establishes a second communication link based on the first configuration.

[0105] Optionally, the remote UE may perform transmission establishment and necessary bearer establishment between the remote UE and the second network node based on the first configuration, so as to establish the second communication link.

[0106] In the SL multi-link establishment method provided in the embodiment of the present application, since the remote UE can receive the link configuration of the second communication link that the remote UE has not established, sent to the remote UE by the first network node via the first communication link that the remote UE already has, the second communication link can be quickly established based on the link configuration of the second communication link when the UE already has one communication link. In this way, multi-path establishment can be achieved for the remote UE.

[0107] Optionally, before the above step 401, the SL multi-path establishment method provided in the embodiment of the present application may further include the following step 403.

[0108] Step 403: The remote UE sends link information of the second communication link to the first network node through the first communication link.

[0109] Optionally, the link information of the second communication link may include at least one of the following:

[0110] Relevant information of the relay UE in the first communication link;

[0111] Serving cell information of the remote UE.

[0112] The relevant information of the relay UE may include at least one of the following: identification information of the relay UE and serving cell information of the relay UE.

[0113] Optionally, the serving cell information of the UE may include an identifier of the serving cell; for example, an Evolved Access Network Cell Global Identifier (E-UTRAN Cell Global Identifier, ECGI) of the serving cell.

[0114] Optionally, the identification information of the relay UE may include at least one of the following: the cell radio network temporary identification (C-RNTI) identification of the relay UE, the international mobile subscriber identity (IMSI) identification, the temporary identity (S-TMSI) identification, the invalid (Inactive)-RNTI identification, the local identification selected by the remote UE for the relay UE, and the SL Layer-2 identification of the relay UE.

[0115] Optionally, the second communication link is different, and the link information of the second communication link is also different.

[0116] For example, assuming that the second communication link is an indirect link of the remote UE, the link information of the second communication link may include: relevant information of the relay UE in the second communication link.

[0117] For example, assuming that the second communication link is a direct link of the remote UE, the link information of the second communication link may include: serving cell information of the remote UE.

[0118] In this way, since the remote UE can send the link information of the second communication link it needs to establish to the first network node, the first network node can trigger the establishment of the second communication link based on the link information after receiving the link information, thereby improving the link establishment speed of the remote UE.

[0119] Optionally, the above step 403 may include the following step 403a.

[0120] Step 403a: When the link quality of the second communication link meets the link quality requirement, the remote UE sends link information of the second communication link to the first network node through the first communication link.

[0121] The link quality requirement may include at least one of the following:

[0122] The link measurement result of the communication link meets the first measurement trigger condition;

[0123] There is an ideal backhaul condition between the relay UE and the remote UE in the communication link.

[0124] Optionally, the first measurement triggering condition may include at least one of the following:

[0125] The link quality between the remote UE and the relay UE is greater than or equal to a first threshold;

[0126] A received signal quality RSRP from the remote UE to the cell in the second network node is greater than or equal to a second threshold.

[0127] Optionally, the link quality between the remote UE and the relay UE being greater than or equal to a first threshold may include at least one of the following:

[0128] The sidelink discovery reference signal received power (SD-RSRP) is greater than or equal to the first subthreshold;

[0129] The sidelink reference signal received power (SL Reference Signal Receiving Power, SL-RSRP) is greater than or equal to the second subthreshold.

[0130] The received signal strength is greater than or equal to the third sub-threshold.

[0131] Optionally, when the second communication link is a direct link of the remote UE, the link information of the second communication link may further include: a link measurement result of the remote UE on the second communication link.

[0132] Optionally, when the link measurement result of the link between the remote UE and the relay UE supporting the PC5 interface, WiFi or Bluetooth meets the first measurement trigger condition, the link information of the second communication link may further include the link measurement result.

[0133] Optionally, in the case where an ideal backhaul condition exists between the remote UE and the relay UE, since the ideal backhaul generally directly connects the remote UE and the relay UE via a wired link such as an optical fiber, there is no need to report the measurement result.

[0134] Optionally, when the second communication link is an indirect link of the remote UE, before reporting the link information of the second communication link, the remote UE needs to interact with the relay UE in the second communication link through a discovery process to obtain information about the service requirements and capabilities of the SL relay. The remote UE may report the link information of the second communication link if it determines that the relay UE supports the relay service required by the remote UE.

[0135] For example, the remote UE and the relay UE may exchange relay service codes, so that the remote UE can determine whether the relay UE supports the relay service of the remote UE.

[0136] Optionally, before the remote UE sends the link information of the second communication link, the remote UE may establish the first communication link if the link quality of the first communication link meets the link quality requirement.

[0137] Example 1, in scenario 1, referring to Figure 5, if the Remote UE has a data transmission requirement and the link quality of the direct link of the remote UE on the Uu interface meets the link quality requirement, the remote UE can establish a connection and necessary bearer with the serving network node of the remote UE, such as the first network node, that is, the Remote UE first has a direct link, so that the remote UE can first transmit data with the network side through the direct link.

[0138] Example 2. In scenario 1, referring to Figure 5, if the Remote UE has a data transmission requirement, and the link quality of the indirect link of the remote UE through the relay UE meets the link quality requirement, for example, the Uu interface RSRP of the Remote UE is less than the Uu interface RSRP threshold, and the relay UE meets the Uu interface RSRP threshold as a relay UE, and the PC5 interface RSRP between the relay UE and the Remote UE is greater than or equal to the PC5 interface RSRP; then the remote UE can establish a connection and necessary bearer establishment to the serving network node of the relay UE, such as the serving base station gNB2, through the relay UE. That is, the Remote UE first has an indirect link, so that the remote UE can first perform data transmission with the network side through the indirect link.

[0139] Example 3. In scenario 3, referring to Figure 7, the Remote UE has a data transmission requirement, and the link quality of the direct link of the remote UE on the Uu interface meets the link quality requirement. The remote UE can establish a connection and necessary bearer establishment between DU1 and CU, that is, the Remote UE first has a direct link, so that the remote UE can first transmit data with the network side through the direct link.

[0140] Example 4. In scenario 3, referring to Figure 7, if the Remote UE has a data transmission requirement, and the link quality of the indirect link of the remote UE through the relay UE meets the link quality requirement, for example, the Uu interface RSRP of the Remote UE is less than the Uu interface RSRP threshold, and the relay UE meets the Uu interface RSRP threshold as a relay UE, and the PC5 interface RSRP between the relay UE and the Remote UE is greater than or equal to the PC5 interface RSRP; then the remote UE can establish a connection and necessary bearer establishment between the relay UE and the service DU2 of the relay UE and the CU, that is, the Remote UE first has an indirect link, so that the remote UE can first transmit data with the network side through the indirect link.

[0141] It can be understood that for the process of the remote UE establishing the first communication link in scenario 2, reference can be made to the relevant process of the remote UE establishing the first communication link in scenario 2, such as Example 3 and Example 4 above.

[0142] In this way, since the remote UE can send the link information of the second communication link to the first network node through the first communication link that the remote UE already has when the link quality of the second communication link meets the link quality requirement, the success rate of the remote UE successfully establishing the second communication link can be improved.

[0143] Optionally, before the above step 403, the SL multi-path establishment method provided in the embodiment of the present application may further include the following step 404.

[0144] Step 404: The remote UE receives first information sent by the first network node through the first communication link.

[0145] The first information may include at least one of the following:

[0146] Link measurement configuration, where the link measurement configuration may include a first measurement triggering condition;

[0147] The first indication information may be used to instruct the remote UE to report information of the relay UE having an ideal backhaul condition with the remote UE.

[0148] Optionally, the above-mentioned link measurement configuration may include at least one of the following: link measurement configuration on PC5 interface, link measurement configuration on PC5 interface, link measurement configuration on Uu interface, and link measurement configuration on non-3GPP interface.

[0149] For example, non-3GPP may include link measurement configuration on a WiFi interface or a Bluetooth interface.

[0150] Optionally, the link measurement configuration on the Uu interface may also be referred to as a neighbor cell measurement configuration.

[0151] Optionally, the link measurement configuration on the Uu interface may include: an RSRP from the remote UE to a cell in the second network node is greater than or equal to a second threshold.

[0152] In this way, since the remote UE can receive the first information sent by the first network node through the communication link that the remote UE already has, the remote UE can determine whether the remote UE has the communication conditions to create another communication link based on the first information, that is, when the communication conditions are met, the link information of the second communication link is reported to the network side, thereby improving the success rate of creating another communication link of the remote UE.

[0153] Optionally, in scenario 1 (i.e., the first network node and the second network node are different access network nodes) or scenario 2 (i.e., the first network node is the first CU and the second network node is the second CU), since the bearer configuration and transmission configuration of the second communication link are generated and controlled by the second network node, and specific configuration information, such as the first configuration, is sent by the second network node to the first network node, and then sent by the first network node to the Remote UE via the first communication link. That is, the second network node does not know whether the remote UE has successfully established the second communication link. Therefore, a method is needed to notify the second network node that the Remote UE has established the second communication link according to the first configuration and can subsequently transmit data via the second communication link.

[0154] Optionally, in the above scenario 1 or scenario 2, after the above step 402, the SL multi-link establishment method provided in the embodiment of the present application may further include at least one of step 405, step 406 and step 407.

[0155] Step 405: The remote UE sends a first message to the first network node.

[0156] The first message may be used to notify the remote UE that the second communication link has been successfully established.

[0157] Optionally, after the remote UE sends the first message to the first network node, the first network node may receive the first message, thereby knowing that the remote UE has successfully established the second communication link. The first network node may then send a notification message to the second network node, where the notification message may be used to notify the remote UE that the second communication link has been successfully established.

[0158] Optionally, the remote UE may send the first message to the first network node through the first communication link.

[0159] Optionally, the first message may be a configuration completion message of the first configuration.

[0160] Optionally, the first message may be used to notify the remote UE that the second communication link has been established according to requirements of the first configuration.

[0161] Step 406: The remote UE sends a second message or arbitrary data to the second network node through the second communication link.

[0162] It can be understood that the second network node can know that the remote UE has successfully established the second communication link after receiving the second message or any data sent through the second communication link.

[0163] The second message may be used to notify the remote UE that the second communication link has been established according to the requirements of the first configuration. The second message may include any one of the following:

[0164] a radio resource control (RRC) message carried on the SRB of the second communication link;

[0165] RRC reconfiguration complete message.

[0166] Optionally, the aforementioned arbitrary data may be SRB data or Data Radio Bearer (DRB) data.

[0167] Optionally, the remote UE may send an RRC message through an established SRB bearer, such as SRB3, to the second network node to inform the second network node that it has successfully established the second communication link.

[0168] Optionally, when the second communication link is an indirect link of the remote UE, the remote UE can first configure the main path or the only path of the remote UE to the SRB1 bearer of the second network node, and then the remote UE can send an RRC reconfiguration completion message to inform the second network node through the RRC reconfiguration completion message that it has successfully established the indirect path.

[0169] Optionally, the remote UE has a primary path or a unique path to send data by default.

[0170] Step 407: The remote UE initiates an access process to the second network node.

[0171] Optionally, the access process may include a layer 2 process with the second network node.

[0172] Optionally, the above L2 process may include a random access process.

[0173] Optionally, taking the second communication link as a direct link of the Remote UE as an example, after the Remote UE successfully establishes the second communication link, the Remote UE may notify the second network node, through a layer 2 procedure between the Remote UE and the second network node, that the remote UE has completed the establishment of the direct link. When the second network node successfully identifies the Remote UE through the layer 2 procedure, it can be known that the Remote UE has successfully established the direct link.

[0174] For example, the Remote UE may notify the second network node that the remote UE has completed the establishment of the direct link by performing a successful non-contention or contention random access procedure on the second network node.

[0175] Optionally, the above embodiment is illustrated by taking the example of the first network node or the remote UE notifying the second network node that the remote UE has successfully established the second communication link. In actual implementation, when the second communication link is an indirect link, the relay UE in the second communication link can also notify the second network node that the remote UE has successfully established the second communication link.

[0176] Exemplarily, after completing the RRC process of the PC5 interface between the relay UE and the remote UE, that is, the relay UE can confirm that the PC5 interface RLC bearer for the relay service is successfully established, thereby confirming that the remote UE has successfully established the second communication link. In this way, the relay UE can send a message to the second network node, which can be used to notify the remote UE that the establishment of the second communication link has been completed.

[0177] The following describes an example of a manner of notifying the second network node that the remote UE has successfully established the second communication link.

[0178] For example, assuming that the first network node is gNB1, the second network node is gNB2, and the second communication link is an indirect link of the Remote UE, then after the Remote UE successfully establishes the second communication link, the following scheme can be used to indicate to gNB1 that the Remote UE has successfully established the indirect link according to the configuration requirements:

[0179] 1) The Remote UE sends a Configuration Complete message for the first configuration to gNB1. After receiving the Configuration Complete message, gNB1 can send a Notification message to gNB2 to indicate that the Remote UE has successfully established the indirect link according to the configuration requirements.

[0180] 2) The Remote UE can send an RRC message via the established SRB bearer to gNB2 to inform gNB2 that it has successfully established the indirect link.

[0181] 3) The Remote UE sends any data, either SRB data or DRB data, over the established path to gNB2. Upon receipt of any data, gNB2 considers the indirect link establishment of the Remote UE successful.

[0182] 4) The Remote UE can perform the PC5 interface RRC procedure with the relay UE via the PC5 interface. After the procedure is completed, the relay UE can confirm that the PC5 interface RLC bearer for the relay service has been successfully established. Therefore, the relay UE can be informed that the remote UE's indirect link has been successfully established. Then, the relay UE can send a message to the relay UE's serving base station gNB2 to notify gNB2 of the successful establishment of the remote UE's indirect link.

[0183] For example, assuming that the first network node is gNB2, the second network node is gNB1, and the second communication link is a direct link of the Remote UE, then: for the newly added direct link of the Remote UE, since the bearer configuration and transmission configuration are generated and controlled by gNB1, and the specific configuration information is sent by gNB1 to gNB2, and then sent by gNB2 to the Remote UE through an RRC message, the Remote UE's configuration completion message can be returned to gNB2 (when the primary link of the Remote UE's SRB1 is still an indirect link). At this time, a method is required to notify gNB1 that the Remote UE has established a direct link according to the configuration and that subsequent data transmission can be carried out. The notification method is one or a combination of the following:

[0184] 1) After receiving the Configuration Complete message from the Remote UE, gNB2 sends a message to gNB1 to indicate that the Remote UE has successfully established a direct link according to the configuration requirements.

[0185] 2) The Remote UE sends an RRC message to gNB1 via the established SRB bearer, such as SRB3, to inform gNB1 that it has successfully established a direct link.

[0186] 3) The Remote UE sends an RRC Reconfiguration Complete message to the SRB1 bearer configured to gNB1 via the primary or sole path, notifying gNB1 that it has successfully established the direct link.

[0187] 4) The Remote UE performs a successful non-contention or contention random access procedure to gNB1 through an L2 procedure, such as a random access procedure. When gNB1 recognizes the identity of the Remote UE, it knows that a direct link has been successfully established.

[0188] 5) The Remote UE sends any data, either SRB data or DRB data, over the established path to gNB1. When gNB1 receives the data, it considers the direct link establishment of the Remote UE successful.

[0189] In this way, the remote UE can directly or indirectly notify the second network node that the remote UE has successfully established the second communication link by sending a first message to the first network node, or sending a second message or arbitrary data to the second network node, or by initiating an access procedure to the second network node. This ensures that the second network node is aware that data transmission with the remote UE via the second communication link is possible. This can improve the flexibility of data transmission.

[0190] The present application provides a method for establishing a multi-path SL. FIG8 shows a flowchart of the method for establishing a multi-path SL provided by the present application. As shown in FIG8 , the method for establishing a multi-path SL provided by the present application may include the following step 801:

[0191] Step 801: A first network node sends a first configuration to a remote UE via a first communication link.

[0192] The first communication link is a communication link between a remote UE and a first network node, and the first configuration may be used to establish a second communication link between the remote UE and a second network node.

[0193] Among them, the communication link in the embodiment of the present application is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link.

[0194] Optionally, scenario 1: the first network node and the second network node are different access network nodes; or, scenario 2: the first network node is the first CU and the second network node is the second CU; or, scenario 3: the first network node and the second network node are both third CUs.

[0195] Optionally, the first configuration may include at least one of the following:

[0196] End-to-end E2E bearer configuration of the remote UE at the second network node;

[0197] Transmission configuration of the remote UE on the PC5 interface;

[0198] Transmission configuration of the remote UE on the Uu interface;

[0199] The basic configuration of the remote UE may include at least one of the cell information and relay UE information configured by the second network node for the remote UE.

[0200] For other descriptions in step 801 , please refer to the relevant descriptions in the above embodiment.

[0201] In the SL multi-link establishment method provided in the embodiment of the present application, since the first network node can send the link configuration of the second communication link that the remote UE has not established to the remote UE through the first communication link that the remote UE already has, the UE can quickly establish the second communication link directly based on the link configuration of the second communication link when it already has one communication link. In this way, multi-path establishment can be achieved for the remote UE.

[0202] Optionally, before the above step 801, the SL multi-link establishment method provided in the embodiment of the present application may also include the following 802.

[0203] Step 802: The first network node receives link information of a second communication link sent by a remote UE through a first communication link.

[0204] Optionally, after receiving the link information of the second communication link, the first network node can judge or identify the second network node in the first communication link based on the link information, so that the first network node can initiate the establishment process of the second communication link to the second network node.

[0205] Optionally, the link information of the second communication link may include at least one of the following:

[0206] Relevant information of the relay UE in the first communication link;

[0207] Serving cell information of remote UE;

[0208] The relevant information of the relay UE may include at least one of the following: identification information of the relay UE and serving cell information of the relay UE.

[0209] In this way, since the first network node can receive the link information of the second communication link sent by the remote UE through the first communication link, the first network node can trigger the establishment of the second communication link based on the link information, thereby improving the link establishment speed of the remote UE.

[0210] Optionally, before the above step 801, the SL multi-link establishment method provided in the embodiment of the present application may also include the following step 803.

[0211] Step 803: The first network node sends first information to the remote UE through the first communication link.

[0212] The first information may include at least one of the following:

[0213] Link measurement configuration, where the link measurement configuration may include a first measurement triggering condition;

[0214] The first indication information may be used to instruct the remote UE to report information of the relay UE having an ideal backhaul condition with the remote UE.

[0215] Optionally, the first network node sends the first information to the remote UE through the first communication link based on that the remote UE has established a first communication link.

[0216] In this way, since the first network node can send the first information to the remote UE through the first communication link that the remote UE already has, the remote UE can determine whether the remote UE has the communication conditions to create another communication link based on the first information. For example, when the communication conditions are met, the link information of the second communication link is reported to the network side, thereby improving the success rate of creating another communication link of the remote UE.

[0217] Optionally, the first network node and the second network node are different access network nodes (scenario 1 above); or, the first network node is the first CU and the second network node is the second CU (scenario 2 above); before the above step 801, the SL multi-link establishment method provided in the embodiment of the present application may also include steps 804 and 805.

[0218] Step 804: The first network node sends a first request message to the second network node.

[0219] The first request message may be used to request adding a second communication link.

[0220] Optionally, the first request message may include at least one of the following:

[0221] Security-related information of the remote UE;

[0222] Communication information of remote UE;

[0223] Protocol Data Unit (PDU) session information offloaded by the remote UE to the second network node;

[0224] DRB identification information supported by the second network node;

[0225] Cell group configuration for remote UE;

[0226] RB information of the offloaded bearer of the remote UE;

[0227] Protection rate information of the remote UE;

[0228] Primary Cell (PC11) information of the remote UE;

[0229] Relevant information of the relay UE in the second communication link;

[0230] Service information and capability information of the remote UE.

[0231] Optionally, the security-related information of the remote UE may include at least one of the following: security capability information of the remote UE, security key information configured by the first network node to the second network node;

[0232] Alternatively, the communication information of the remote UE may include at least one of the following information of the remote UE at the second network node: an aggregate maximum bit rate (AMBR), a selected public land mobile network (PLMN) identifier, a mobility restriction list, a radio access index, and a frequency selection priority;

[0233] Alternatively, the PDU session information may include at least one of the following: session identification information, quality of service (QoS) flow information in the session, slice information, maximum bit rate of the session, and session resource information;

[0234] Alternatively, the DRB identification information supported by the second network node may include at least one of the following: an identification list of DRBs supported by the second network node, and scope information of DRBs supported by the second network node;

[0235] Alternatively, the cell group configuration may include cell group information that the second network node is expected to establish, modify, or release;

[0236] Alternatively, the RB information of the offload bearer of the remote UE may include: at least one of SRB information of the offload bearer of the remote UE and DRB information of the offload bearer.

[0237] Alternatively, the protection rate information of the remote UE may include at least one of the following: an uplink protection rate and a downlink protection rate of the remote UE.

[0238] Alternatively, the primary cell information of the remote UE may include a Pc1 identifier of the remote UE.

[0239] Alternatively, the relevant information of the relay UE may include at least one of the following: a Layer-2 identifier of the relay UE, an identifier of a serving cell of the relay UE, and a serving cell list of the relay UE.

[0240] Optionally, when the second communication link is a direct communication link of the remote UE, and the second network node is added as a master node (M (Master)-Node), that is, the second network node serves as the master cell group (MCG) node of the remote UE, the first request message may include the service information and capability information of the remote UE. That is, the overall service information and capability information of the remote UE are handed over to the MCG through the first request message, and the MCG performs the division between the MCG and the secondary cell group (SCG).

[0241] Optionally, when the second communication link is an indirect communication link of the remote UE; or the second communication link is a direct communication link of the remote UE and the second network node is added as a secondary node, the first request message may include at least one of the above information except the service information and capability information of the remote UE.

[0242] It's important to note that the second communication link is the addition of a direct link in a multipath. If this addition process is a redesigned Xn interface process 1, this design already reflects the difference from existing direct and indirect link operations. However, if the Xn interface signaling process is reused, such as by multiplexing an SCG, the second network node must be explicitly or implicitly instructed that the second communication link is being added while the first communication link exists.

[0243] For example, the explicit indication may be: indicating, through a dedicated field in the first request message, that this is the addition of the second communication link in the multipath.

[0244] For example, the implicit indication may be: a newly added configuration field in the first request message, indicating that the second communication link is a direct link or an indirect link that is different from the single communication link in the related art.

[0245] Step 805: The first network node receives a first response message sent by the second network node.

[0246] The first response message may be used to indicate that the second network node supports providing a transmission service for the remote UE, and the first response message may include the first configuration.

[0247] Optionally, the first configuration may be generated for the second network node.

[0248] Optionally, the first request message and the first response message may be referred to as a process of adding the second communication link initiated by the first network node.

[0249] Optionally, 1) the above-mentioned addition process can reuse the Xn interface signaling process, such as the secondary node addition preparation (S-NG-RAN node Addition Preparation) process. Among them, the successful addition process may include: the first network node sends a secondary node addition request message (S-NODE ADDITION REQUEST), and receives a secondary node addition response message (S-NODE ADDITION REQUEST ACKNOWLEDGE) sent by the second network node. Among them, a field is added to the secondary node addition request message to carry through the field: it is the addition information of the second communication link when the first communication link exists. Optionally, in 1), a field that can be used to carry the first configuration can be added to the S-NODE ADDITION REQUEST ACKNOWLEDGE.

[0250] Alternatively, the addition process may be a separately designed Xn interface signaling process, hereinafter referred to as Xn interface signaling process 1. For example, Xn interface signaling process 1 may include any of the following: 2) a multipath addition preparation process, or 3) a Class M next generation radio access network (NGRAN) node addition preparation process. A successful multipath addition preparation process may include a Multi-path Addition Request message and a corresponding acknowledgement signaling message.

[0251] Optionally, in 1), the first request message may include: a Multi-path Addition Request message in a multi-path addition preparation process, and the first response message may include an S-NODE ADDITION REQUEST ACKNOWLEDGE message.

[0252] For example, the first request message may include: an M-NODE ADDITION REQUEST message in the M-NG-RAN node Addition Preparation process, and the first response message may include an M-NODE ADDITION REQUEST ACKNOWLEDGE message in the M-NG-RAN node Addition Preparation process.

[0253] For example, the first request message may include: a Multi-path Addition Request message in a Multi-path Addition Preparation process, and the first response message may include a Multi-path Addition Acknowledge message.

[0254] It should be noted that the embodiment of the present application does not limit the name of the first Xn interface signaling process. For example, the first Xn interface signaling process can also be any Xn interface signaling process other than the Multi-path Addition Preparation and M-NG-RAN node Addition Preparation processes.

[0255] It can be seen that when the first network node and the second network node are different access network nodes; or when the first network node is a first CU and the second network node is a second CU, the first configuration is controlled and generated by the second network node.

[0256] In this way, since the first network node can obtain the first configuration from the second network node through the first request message and the first response message, the convenience of obtaining the first configuration can be improved.

[0257] Optionally, the first network node and the second network node are different access network nodes; or, the first network node is the first CU and the second network node is the second CU; after the above step 801, the SL multi-link establishment method provided in the embodiment of the present application may also include the following steps 806 and 807.

[0258] Step 806: The first network node receives a first message sent by the remote UE.

[0259] The first message may be used to notify the remote UE that the second communication link has been successfully established.

[0260] Optionally, the first message may be a configuration completion message of the first configuration.

[0261] Step 807: The first network node sends a third message to the second network node. The third message may be used to notify the remote UE that the second communication link has been successfully established.

[0262] In this way, since the first network node can send a third message to the second network node after receiving the first message sent by the remote UE, which can be used to notify the remote UE that the second communication link has been successfully established, the third network node can know through the third message that the remote UE has successfully established the second communication link.

[0263] For other descriptions in the embodiments of the present application, please refer to the relevant descriptions in the above embodiments. In order to avoid repetition, they will not be repeated here.

[0264] An embodiment of the present application provides a SL multi-path establishment method. Figure 9 shows a flowchart of the SL multi-path establishment method provided by the embodiment of the present application. As shown in Figure 9, the SL multi-path establishment method provided by the embodiment of the present application may include the following step 901.

[0265] Step 901: A second network node sends a first configuration.

[0266] The first configuration may be used to establish a second communication link between the remote UE and the second network node.

[0267] The second communication link is different from the first communication link of the remote UE; the first communication link is a communication link between the remote UE and the first network node, and the first communication link can be used by the first network node to send the first configuration to the remote UE.

[0268] The communication link is a direct link or an indirect link of the remote UE.

[0269] Optionally, the first configuration may include at least one of the following:

[0270] End-to-end E2E bearer configuration of the remote UE at the second network node;

[0271] Transmission configuration of the remote UE on the PC5 interface;

[0272] Transmission configuration of the remote UE on the Uu interface;

[0273] The basic configuration of the remote UE may include at least one of the cell information and relay UE information configured by the second network node for the remote UE.

[0274] Optionally, scenario 1: the first network node and the second network node are different access network nodes; or, scenario 2: the first network node is the first CU and the second network node is the second CU; or, scenario 3: the first network node and the second network node are both third CUs.

[0275] The following describes the SL multi-path establishment method provided in the embodiment of the present application in combination with scenarios 1 to 3.

[0276] 1. In Scenario 1 and Scenario 2

[0277] Alternatively, the first network node and the second network node are different access network nodes; or the first network node is a first CU and the second network node is a second CU. The above step 901 may include the following steps 901a and 901b.

[0278] Step 901a: The second network node receives a first request message sent by the first network node. The first request message may be used to request adding a second communication link.

[0279] Optionally, the first request message may include at least one of the following:

[0280] Security-related information of the remote UE;

[0281] Communication information of remote UE;

[0282] PDU session information offloaded by the remote UE to the second network node;

[0283] Data radio bearer (DRB) identification information supported by the second network node;

[0284] Cell group configuration for remote UE;

[0285] RB information of the offloaded bearer of the remote UE;

[0286] Protection rate information of the remote UE;

[0287] Primary cell information of the remote UE;

[0288] Relevant information of the relay UE in the second communication link;

[0289] Service information and capability information of the remote UE.

[0290] Step 901b: The second network node sends a first response message to the first network node.

[0291] The first response message may include the first configuration.

[0292] Optionally, the second communication link is a direct link of the remote UE, and the first response message may include S-NODE, M-NODE or MULTI-PATH ADDITION REQUEST ACKNOWLEDGE signaling, or an addition request response message with other names.

[0293] Optionally, the second communication link is a direct link of the remote UE, and the first response message may include any one of the following: S-NODE ADDITION REQUEST ACKNOWLEDGE message, Multi-path Addition Request Acknowledge, and other name addition request response messages.

[0294] In this way, since the second network node can send a first response message to the first network node, and the first response message can include the first configuration, the first network node can obtain the configuration that can be used to establish the second communication link with the remote UE through the first response message.

[0295] Optionally, after the above step 901a, the SL multi-link establishment method provided in the embodiment of the present application may further include at least one step from step 902 to step 905.

[0296] Step 902: The second network node accepts the first service and generates configurations of the remote UE and the first relay UE.

[0297] The first service is a service that the remote UE needs to transmit through the second communication link, and the first relay UE is a relay UE in the second communication link.

[0298] Optionally, when the second communication link is an indirect link of the remote UE, the second network node may perform step 902 .

[0299] It should be noted that the configurations of the remote UE and the first relay UE generated by the second network node are configurations that can be used for the remote UE and the second relay UE to establish relevant bearers and transmissions of the second communication link, respectively.

[0300] Step 902: The second network node sends an RRC reconfiguration message to the first relay UE.

[0301] Optionally, the RRC reconfiguration message may include at least one of information about the first service and relevant information about the first relay UE.

[0302] Optionally, the first service is a service that the remote UE needs to transmit through the second communication link, and the first relay UE is a relay UE in the second communication link.

[0303] Optionally, the RRC reconfiguration message may be RRC reconfiguration signaling.

[0304] Optionally, the RRC reconfiguration message may include at least one of the following:

[0305] Remote UE identifier, such as Layer 2 identifier;

[0306] The remote UE needs to relay service information, such as an end-to-end bearer identifier, such as an end-to-end RB identifier.

[0307] Transmission configuration of the remote UE service on the Uu interface of the relay UE. For example, the transmission configuration may include at least one of the following: mapping information between the remote UE RB identifier and the first relay UE Uu interface RLC bearer, and the first relay UE Uu interface RLC bearer information.

[0308] Transmission configuration of the remote UE's service on the PC5 interface of the first relay UE. For example, the transmission configuration may include at least one of the following: mapping information of the remote UE RB identifier to the first relay UE PC5 interface RLC bearer, and first relay UE PC5 interface RLC bearer information.

[0309] Optionally, the first service is a service that the remote UE needs to transmit through the second communication link, and the first relay UE is a relay UE in the second communication link.

[0310] Step 903: The second network node generates a configuration of the remote UE.

[0311] Optionally, the configuration of the remote UE generated by the second network node may include the above-mentioned first configuration.

[0312] Optionally, the second communication link is an indirect link of the remote UE, and the configuration of the remote UE generated by the second network node may include at least one of the following:

[0313] End-to-end bearer configuration of the Remote UE at the second network node;

[0314] The transmission configuration of the Remote UE bearer on the PC5 interface, such as the mapping information from the Remote UE RB identifier to the Remote UE PC5 interface RLC bearer;

[0315] Newly added Remote UE PC5 interface RLC bearer information;

[0316] Basic configuration of the Remote UE on the second network node, such as the serving cell information and Pcell information of the Remote UE on the second network node;

[0317] Related information of the first relay UE, such as the relay UE L2 identifier.

[0318] Optionally, the second communication link is a direct link of the remote UE, and the configuration of the remote UE generated by the second network node may include at least one of the following:

[0319] It may include end-to-end bearer information of the Remote UE on the first network node;

[0320] The transmission configuration of the Remote UE bearer on the Uu interface, such as the mapping information of the Remote UE RB identifier to the Remote UE Uu interface RLC bearer;

[0321] Added Remote UE Uu interface RLC bearer information;

[0322] Basic configuration of the Remote UE in the second network node, such as serving cell information and Pcell information.

[0323] Step 904: The second network node accepts the first service and generates a configuration for the remote UE.

[0324] The first service is a service that the remote UE needs to transmit through the second communication link.

[0325] Optionally, the second network node may accommodate the service that the Remote UE needs to transmit through the second communication link, allow multi-path establishment, and form a configuration for the Remote UE, such as the first configuration.

[0326] It should be noted that, for the above-mentioned scenarios 2 and 3, that is, when the access network node is a DU-CU architecture, the establishment of the second communication path will involve signaling interaction between the CU-DU interfaces.

[0327] The signaling interaction between CU and DU is described below.

[0328] Optionally, in scenario 2 or scenario 3, the SL multi-link establishment method provided in the embodiment of the present application may also include the following steps 906 and 907.

[0329] Step 906: The fourth CU sends a second request message to the first DU.

[0330] Among them, the fourth CU is the second CU or the third CU; the first DU is the DU corresponding to the second communication link, and the second request message can be used to request the transmission configuration of the remote UE that is responsible for the first DU in the second communication link, and the second request message can include the second configuration, and the second configuration can include the E2E bearer configuration of the remote UE in the fourth CU.

[0331] Optionally, the above-mentioned E2E bearer configuration may include: a list of SRBs and DRBs of the remote UE in the fourth CU and attribute information, for example, it may include some configurations of the PDCP layer and above layers.

[0332] Optionally, the transmission configuration of the remote UE that is responsible for the first DU may include: configuration of protocol layers below PDCP, for example, configuration of SRAP, RLC, MAC and PHY protocol layers.

[0333] It can be understood that in the CU-DU architecture, the DU is responsible for the configuration of the protocol layers below the PDCP, and the CU is responsible for the configuration of the PDCP protocol layer and the protocol layers above the PDCP.

[0334] Step 907: The fourth CU receives the second response message sent by the first DU.

[0335] The second response message may include the third configuration and the acceptance result of the first DU for the second configuration.

[0336] Optionally, in Mode 1, the second communication link is a direct link to the remote UE, and the third configuration may include the transmission configuration configured by the first DU for the remote UE on the Uu interface. Alternatively, in Mode 2, the second communication link is an indirect link to the remote UE, and the third configuration may include the transmission configuration configured by the first DU for the remote UE on the PC5 interface.

[0337] Optionally, after receiving the second request message, the first DU may first determine which configurations in the second configuration can be accepted. If the first DU successfully accepts the second configuration, such as accepting at least part of the second configuration, the acceptance result may include: an SRB list and a DRB list that were successfully accepted, or an SRB list and a DRB list that were not successfully accepted.

[0338] It can be understood that the above acceptance result can be used to indicate the degree of acceptance of the second configuration by the first DU or which configurations of the second configuration are accepted.

[0339] Optionally, in mode 1, the third configuration may include: configuration of a Uu interface RLC channel of the remote UE, and a mapping relationship between the configuration accepted by the first DU from the second configuration and the Uu interface RLC channel.

[0340] Optionally, in mode 2, the third configuration may include: configuration of a PC5 interface RLC channel of the remote UE, and a mapping relationship between the configuration accepted by the first DU from the second configuration and the PC5 interface RLC channel.

[0341] Optionally, the third configuration may be generated by the first DU based on the configuration it adopts from the second configuration.

[0342] Alternatively, in Option 1, since the DU is only responsible for processing protocol layers below PDCP, for the remote UE's indirect link, the Uu interface SRAP, Uu interface RLC, Uu interface MAC, and Uu interface PHY protocol layers are located in the DU, and these protocol layers are all from the relay UE. Therefore, in Option 1, the DU can provide the remote UE's Uu interface RLC channel configuration and the mapping between this channel configuration and the E2E bearer configuration accepted by the first DU.

[0343] Optionally, the RLC channel configuration of the PC5 interface or Uu interface configured by the DU for the remote UE corresponds to the E2E bearer configuration it accepts. That is, the E2E bearer configuration is an upper-layer configuration, and the channel configuration is a lower-layer configuration corresponding to the E2E bearer configuration.

[0344] For example, the first DU provides the lower half configuration corresponding to the SRB or DRB it accepts, and the lower half configuration may include at least one of the RLC, MAC and PHY configurations corresponding to the SRB or DRB.

[0345] Optionally, the second request message and the second response message may be referred to as a process related to adding a second communication link.

[0346] Optionally, the fourth CU may initiate a process related to adding the second communication link to the first DU through an interface between the CU and the DU, such as the F1 interface.

[0347] Optionally, the above-mentioned addition-related process may reuse the existing F1 interface signaling process to establish the configuration related to the second communication link of the remote UE through the process, or use a new signaling process to establish the configuration of the second communication link of the Remote UE.

[0348] For example, the above-mentioned adding-related process may include: a UE context establishment (Context Setup) process, wherein the adding-related process successfully includes: the fourth CU sending a UE CONTEXT SETUP REQUEST message, and receiving a UE CONTEXT SETUP RESPONSE message sent by the first DU.

[0349] For example, the aforementioned addition-related process may include: a UE context modification process, or a new signaling process to establish the configuration of the second communication link of the Remote UE itself. The addition-related process successfully includes: the fourth CU sending a UE CONTEXT MODIFICATION REQUEST message, and receiving a UE CONTEXT MODIFICATION RESPONSE message sent by the first DU.

[0350] Optionally, the first configuration may be generated for the remote UE by the fourth CU with reference to the third configuration and the configuration adopted by the first DU from the second configuration. The specific configuration may be determined based on actual needs and is not limited in this embodiment of the present application. Optionally, step 901 may be performed after step 907.

[0351] In this way, when the first network node is the first CU and the second network node is the second CU; or, when the first network node and the second network node are both the third CU, the second network node can send a second request message to the first DU in the second communication link to send the E2E bearer configuration of the remote UE in the third or second CU to the first DU, so that the first DU can accept the bearer configuration and return its acceptance result and the third configuration configured for the remote UE through a second response message. In this way, the CU and the related DU can obtain the complete configuration of the remote UE.

[0352] Optionally, in scenario 2 or scenario 3, when the second communication link is an indirect link of the remote UE, the SL multi-link establishment method provided in the embodiment of the present application may also include the following steps 908 and 909.

[0353] Step 908: The fourth CU sends a third request message to the first DU.

[0354] Among them, the fourth CU is the second CU or the third CU; the first DU is the DU corresponding to the second communication link, and the third request message can be used to request the transmission configuration of the relay UE in the second communication link that is responsible for the first DU, and the third request message can include the fourth configuration, and the fourth configuration can include the E2E bearer configuration of the remote UE in the fourth CU.

[0355] Optionally, the fourth configuration may include: a list of SRBs and DRBs of the remote UE in the fourth CU and attribute information, for example, may include some configurations of the PDCP layer and above layers.

[0356] Optionally, the transmission configuration of the remote UE that is responsible for the first DU may include: configuration of protocol layers below PDCP, for example, configuration of SRAP, RLC, MAC and PHY protocol layers.

[0357] It can be understood that in the CU-DU architecture, the DU is responsible for the configuration of the protocol layers below the PDCP, and the CU is responsible for the configuration of the PDCP protocol layer and the protocol layers above the PDCP.

[0358] Step 909: The fourth CU receives a third response message sent by the first DU. The third response message may include the fifth configuration and the acceptance result of the first DU for the fourth configuration.

[0359] The fifth configuration may include the transmission configuration on the PC5 interface and the Uu interface configured by the first DU for the relay UE.

[0360] Optionally, after receiving the third request message, the first DU may first determine which configurations in the fourth configuration can be accepted. If the first DU successfully accepts the request, such as accepting at least some of the configurations in the fourth configuration, the acceptance result in step 908 may include: an SRB list and a DRB list that were successfully accepted, or an SRB list and a DRB list that were not successfully accepted.

[0361] It can be understood that the above acceptance result can be used to indicate the degree of acceptance of the fourth configuration by the first DU or which configurations of the fourth configuration are accepted.

[0362] Optionally, the transmission configuration configured by the first DU for the relay UE on the PC5 interface and the Uu interface may include: the Uu interface RLC channel configuration configured by the first DU for the relay UE, and a mapping relationship between the Uu interface RLC channel configuration and the E2E RB of the Remote UE in the fourth CU; the PC5 interface RLC channel configuration configured by the first DU for the relay UE, and a mapping relationship between the PC5 interface RLC channel and the E2E RB from the Remote UE to the fourth CU. This is equivalent to opening up transmission channels between a DU and the relay UE, and between the relay UE and the Remote UE for relaying Remote UE services.

[0363] Optionally, since the CU and DU are in a controlling and controlled relationship, after the fourth CU instructs the first DU to complete the relevant configuration of the second communication link, it needs to send an RRC reconfiguration message to the relay UE. The RRC reconfiguration message may include: the addition of the Uu interface RLC channel of the relay UE and the mapping relationship between the Uu interface RLC channel and the Remote UE's E2E RB in the fourth CU, etc.; the addition of the PC5 interface RLC channel and the mapping relationship between the PC5 interface RLC channel and the Remote UE to the E2E RB of the fourth CU, etc.

[0364] For other descriptions in the embodiments of the present application, please refer to the relevant descriptions in the above embodiments. In order to avoid repetition, they will not be repeated here.

[0365] It should be noted that the embodiment of the present application does not limit the execution order of step 906 and step 908. Step 906 and step 908 can be executed simultaneously, or step 906 can be executed first and then step 908, or step 908 can be executed first and then step 906.

[0366] In this way, since the first network node can send the first information that may include at least one of the measurement link configuration and the first indication information to the remote UE through the communication link that the remote UE already has, the remote UE can determine whether the remote UE has the communication conditions for establishing another communication link based on the first information, that is, when the communication conditions are met, the link information of the second communication link is reported to the network side, thereby improving the success rate of establishing another communication link of the remote UE.

[0367] The SL multi-path establishment method provided in the embodiment of the present application is described below in conjunction with a specific implementation method.

[0368] A possible implementation: the first network node and the second network node are different access network nodes

[0369] Figure 5 shows a typical inter-gNB multi-path architecture. The remote UE establishes a direct link through gNB1 and an indirect link through the relay UE and gNB2. Because this scenario spans two nodes, the establishment process and the information carried are significantly different from a single-node scenario.

[0370] Implementation method 1: Adding an inter-gNB indirect link. This method provides the process and details of how a Remote UE can add an inter-gNB indirect link based on an existing direct link.

[0371] 5 , in Implementation 1, the first network node is gNB1 and the second network node is gNB2. As shown in FIG10 , Implementation 1 may include the following steps:

[0372] Step 100: gNB1 sends first information to the remote UE through the remote UE's direct link.

[0373] Optionally, assuming that the Remote UE has a need for data transmission and the Uu interface link meets the communication requirements, the remote UE can first establish a connection and necessary bearer establishment with its own serving base station gNB1 according to the existing process, that is, the Remote UE first has a direct link to transmit data with the network side.

[0374] Optionally, based on the remote UE having a direct link, gNB1 may send the first information to the remote UE through the direct link.

[0375] Exemplarily, the first information may include a link measurement configuration, so that the remote UE can search for available relay UEs around the remote UE based on the link measurement configuration configured by gNB1. For example, the link measurement configuration may include PC5, WiFi, or Bluetooth measurements.

[0376] Exemplarily, gNB1 may instruct the Remote UE by means of dedicated signaling or public signaling, allowing it to report information of the relay UE that has an ideal backhaul condition with the Remote UE, that is, the first information is dedicated signaling or public signaling.

[0377] Step 101: A remote UE receives first information.

[0378] Step 102: When the link quality of the remote UE's indirect link meets the link quality requirement, the remote UE sends link information of the indirect link to gNB1 through the direct link.

[0379] Optionally, gNB1 is a serving base station for the remote UE.

[0380] Optionally, if the indirect link satisfies the measurement trigger conditions configured by gNB1 (i.e., the measurement trigger conditions that may be included in the link measurement configuration, such as the first measurement trigger condition in the above embodiment), for example, if the PC5, WiFi, or Bluetooth link measurement results meet the basic communication threshold, the Remote UE may report the corresponding relay UE identification information (or the relay UE's serving cell information), the link measurement results of the indirect link, etc., to the Remote UE's serving base station gNB1. Alternatively, if the Remote UE meets the ideal backhaul condition with the relay UE, it may report at least one of the relay UE identification information and the relay UE's serving cell information to its own serving base station gNB1.

[0381] The following further illustrates step 102 by taking the communication interface between the remote UE and the relay UE as an example.

[0382] (1) PC5 interface. If it is a PC5 interface, that is, the SL link between the remote UE and the relay UE is an SL link based on the PC5 interface, the relay UE and the Remote UE need to exchange information about each other's requirements and capabilities for SL relay through the PC5 discovery process. For example, what services (such as relay service code) related to the Remote UE need to be provided with transit or relay services, what services (such as the relay service code corresponding to the relay UE) related to the relay or relay services that the relay UE can or is capable of providing, etc. Only when the services supported by the relay UE match the service requirements of the remote UE, and the link quality between the Remote UE and the relay UE meets the threshold requirement (such as the first threshold mentioned above), for example, SD-RSRP or SL-RSRP is higher than a certain threshold, in this case, it means that the relay UE meets the conditions for providing relay services to the Remote UE, and the remote UE can report to gNB1.

[0383] When the PC5 interface is used between two UEs, the relay UE identification information reported by the remote UE is generally the relay UE's SL Layer-2 identification. In addition, the remote UE can obtain the relay UE's serving cell information through the discovery process and report it to its serving base station gNB1.

[0384] (2) Wired link interface. Ideal backhaul is achieved between the remote UE and the relay UE. Because ideal backhaul typically involves a direct connection between the remote UE and relay UE via a wired link, such as an optical fiber, link quality measurement and reporting of link measurement results are not required. Ideal backhaul only requires meeting ideal backhaul conditions, such as a direct optical fiber or wired connection between the two UEs. A remote UE that meets these conditions, i.e., a remote UE connected to another UE via a wired link, can directly report information about its connected relay UE to its serving base station, gNB1.

[0385] Generally, the relay UE's identification information needs to be reported. This identification information can include the relay UE's C-RNTI, IMSI, S-TMSI, I-RNTI, or other identifiers, or local identification information selected by the remote UE for the relay UE. Furthermore, the two UEs need to inform the remote UE of the relay UE's serving cell information through the wired interface between the UEs, and the remote UE will report the information to its serving base station gNB1.

[0386] (3) Non-3GPP interface. Non-3GPP interfaces may include WiFi or Bluetooth. When the Remote UE detects an available relay UE nearby and can provide relay services for itself through non-3GPP transmission such as WiFi or Bluetooth between UEs, it is generally necessary to meet basic link quality requirements between the two UEs, such as communication link quality requirements, for example, the received signal strength must be above a certain threshold. For relay UEs that meet the conditions, the Remote UE needs to report the relay UE's identification information, which can be the relay UE's C-RNTI, IMSI, S-TMSI, I-RNTI, or other identifiers, or local identification information selected by the Remote UE for the relay UE. In addition, the two UEs also need to inform the Remote UE of the relay UE's serving cell information through the non-3GPP interface between the UEs, and the Remote UE will report it to its own serving base station gNB1.

[0387] It should be noted that the remote UE reports link information via the direct link between the remote UE and the gNB.

[0388] Step 103: gNB1 receives link information of the indirect link of the remote UE.

[0389] Optionally, when the Remote UE's serving base station gNB1 receives a report from the Remote UE, it can determine the relay UE's serving cell information in the link information, typically the serving cell identifier (e.g., ECGI). If the cell is not managed by this base station, and based on inter-gNB interface interaction information, such as the Xn establishment process, it can be determined to be a cell under neighboring gNB2, then if gNB1 and / or gNB2 support inter-gNB multi-path functionality, gNB1 can initiate an indirect link addition process to gNB2.

[0390] Step 104: gNB1 sends a first request message to gNB2.

[0391] Optionally, gNB1 sends a first request message to gNB2 through an interface between base stations, such as an Xn interface, to initiate an indirect link addition process for the Remote UE.

[0392] Optionally, the indirect link addition process of the Remote UE can reuse existing Xn interface signaling processes, such as the S-NG-RAN node Addition Preparation process. A successful addition process can include S-NODE ADDITION REQUEST and S-NODE ADDITION REQUEST ACKNOWLEDGE signaling. A new field is added to the Request signaling to carry the relay relationship between the Remote UE and the relay UE and necessary relay information, thereby obtaining a first request message.

[0393] Alternatively, for the Remote UE's indirect link addition process, a new Xn interface signaling process can be designed, such as Multi-path Addition Preparation, Multi-path Addition Request, and corresponding acknowledge signaling. Alternatively, other names and appropriate signaling fields can be used to carry relay UE information and relay service information in the corresponding request message.

[0394] The first request message, such as the add request message, should carry at least one or a combination of the following information:

[0395] Remote UE security-related information may include at least one of the following: Remote UE security capability information, security key information provided by gNB1 to gNB2;

[0396] Some basic communication information of the Remote UE, including but not limited to the AMBR on gNB2, Selected PLMN, Mobility Restriction List, Index to RAT, Frequency Selection Priority, etc.

[0397] Information about the PDU session offloaded from the Remote UE to gNB2 may include session identifier, QoS flow information within the session, slice information, maximum session bit rate, and session resource information.

[0398] DRB identification information that can be used by gNB2 may include an identification list or range information;

[0399] Cell group configuration information may include information about the cell group that the gNB2 wants to establish, modify, or release;

[0400] Split RB information, which may include split SRB information, split DRB information, etc.

[0401] Integrity protection rate information, including uplink integrity protection rate, downlink integrity protection rate, etc.

[0402] Pcell information, which may include a PCell identifier, etc.

[0403] The related information of the relay UE may include the Layer-2 identity of the relay UE and / or the serving cell identity or list of the relay UE.

[0404] Step 105: gNB2 receives the first request message.

[0405] Step 106: gNB2 sends a first response message to gNB1.

[0406] Optionally, the first response message may include a first configuration, and the first configuration may be used to establish a second communication link between the remote UE and the second network node.

[0407] Optionally, gNB2 responds to the first request message to gNB1 through the interface between base stations, such as the Xn interface, i.e., the indirect link addition process of the Remote UE.

[0408] After receiving the first request message, such as the add request message, from the remote UE's serving base station gNB1, the relay UE's serving base station gNB2 may respond. A successful response may include one or a combination of the following:

[0409] -gNB2 accepts the services that the Remote UE needs to relay through the Relay UE and configures the Relay UE and Remote UE separately.

[0410] - Sending RRC reconfiguration signaling to the relay UE (step A) to configure the service information and relay information related to the Remote UE to the relay UE, which may include at least one of the following:

[0411] Remote UE identifier (e.g. Layer 2 identifier),

[0412] Remote UE needs to relay service information (such as end-to-end bearer identifier, RB identifier),

[0413] Transmission information of the Remote UE's services on the relay UE's Uu interface (e.g., mapping information of the Remote UE RB identifier to the relay UE Uu interface RLC bearer, newly added relay UE Uu interface RLC bearer information, etc.),

[0414] Transmission information of the Remote UE's services on the relay UE's PC5 interface (e.g., mapping information from the Remote UE RB identifier to the relay UE PC5 interface RLC bearer, information of newly added relay UE PC5 interface RLC bearer, etc.);

[0415] -Generate configuration information for the Remote UE, which may include the Remote UE's end-to-end bearer information on gNB2, the Remote UE's bearer transmission information on the PC5 interface (e.g., mapping information from the Remote UE RB identifier to the Remote UE PC5 interface RLC bearer, newly added Remote UE PC5 interface RLC bearer information, etc.), as well as the Remote UE's basic configuration on gNB2, such as serving cell information, PCell information, etc., and relay UE information, such as the relay UE L2 identifier;

[0416] -gNB2 sends the generated Remote UE configuration, i.e., the first configuration, to gNB1 in an S-NODE ADDITION REQUEST ACKNOWLEDGE signaling message or a Multi-path Addition Request Acknowledge message or other named addition request acknowledgment message (i.e., the first response message).

[0417] Optionally, gNB2 may perform step 01 after step 106. For example, as shown in FIG10 , gNB2 may perform step A after step 106 and before step 107. It is understood that after gNB2 performs step 106, the relay UE may receive the RRC reconfiguration signaling sent by gNB2 and establish a connection and bearer related to the indirect link with the remote UE.

[0418] Step 107: gNB1 receives the first response message.

[0419] Step 108: gNB1 sends the first configuration to the remote UE through the remote UE's direct link.

[0420] Optionally, when the first response message indicates that gNB2 successfully accepts the Remote UE to be provided with relay services by the relay UE, gNB2 sends the configuration information (e.g., the first configuration) for the Remote UE to the Remote UE via an RRC reconfiguration message. That is, the first configuration can be carried in the RRC reconfiguration signaling.

[0421] Step 109: The remote UE receives the first configuration.

[0422] Step 110: The remote UE establishes an indirect link to the remote UE based on the first configuration.

[0423] Optionally, the remote UE receives the reconfiguration message and establishes a new indirect link from the relay UE to gNB2 according to the relay UE identifier and the first configuration, such as the configuration information of gNB2, thereby forming a multipath to the network side together with the original direct link to gNB1 for its own service transmission.

[0424] It should be noted that the configuration and transmission of the newly added indirect link are generated and controlled by gNB2. The specific configuration information is sent by gNB2 to gNB1, and then by gNB1 to the Remote UE. The Remote UE's configuration completion signaling is returned to gNB1. However, a method is required to notify gNB2 that the Remote UE has established the indirect link according to the configuration and that subsequent data transmission is possible. The notification methods include one or a combination of the following:

[0425] - After receiving the Configuration Complete message from the Remote UE, gNB1 indicates to gNB2 that the Remote UE has successfully established the indirect link according to the configuration requirements;

[0426] -The Remote UE sends an RRC message via the newly established SRB bearer to gNB2, notifying gNB2 that it has successfully established the indirect link.

[0427] The Remote UE sends any data, either SRB data or DRB data, over the newly established path to gNB2. Upon receiving this data, gNB2 considers the Remote UE indirect link established successfully.

[0428] The PC5 interface RRC procedure between the remote UE and the relay UE confirms the successful establishment of the PC5 interface RLC bearer for the relay service. The relay UE is then informed that the remote UE's indirect link has been successfully established. The relay UE then notifies the serving base station gNB2 of the successful establishment of the remote UE's indirect link.

[0429] It should also be noted that in the architecture shown in Figure 5, the PCell in the direct link is more important because the remote UE's direct link has a shorter transmission hop count and its configuration inherently shares the configuration attributes of a traditional Uu interface link. On the other hand, since the indirect link primarily configures the PC5 interface link for the remote UE and does not require direct cell group or PCell configuration to gNB2, the direct link's PCell can be used as the remote UE's PCell, allowing for reuse of PCell failure and recovery behaviors.

[0430] Optionally, the remote UE's SRB1 can also set the direct link as the sole or primary path. When the direct link fails, it will follow the MCG failure behavior. Since indirect failure does not affect SRB1 transmission, a more gentle recovery method can be adopted, such as simply reporting UE assistance information (Assistance Information) or SCG failure information (Failure Information) and waiting for network processing, without affecting the remote UE's data transmission.

[0431] Implementation method 2: Adding an inter-gNB direct link. This method provides the process and details of how the Remote UE can add an inter-gNB direct link based on the existing indirect link.

[0432] As shown in combination with Figure 5, in implementation method 2, the first network node is gNB2 and the second network node is gNB1.

[0433] As shown in FIG11 , implementation method 2 may include the following steps:

[0434] Step 110: gNB2 sends first information to the remote UE through the indirect link of the remote UE.

[0435] It can be understood that the remote UE can receive the first information.

[0436] It can be understood that gNB2 sends the first information to the remote UE through the relay UE.

[0437] Optionally, assuming that the Remote UE has a need for data transmission and the current indirect link through the relay UE meets the communication requirements, for example, the Uu interface RSRP of the Remote UE is less than the Uu interface RSRP threshold condition, and the relay UE meets the Uu interface RSRP threshold condition as a relay, and the PC5 interface RSRP between the relay UE and the Remote UE is greater than or equal to the PC5 interface RSRP to meet the communication requirements; therefore, the remote UE can first follow the existing process, and the Remote UE can establish a connection and necessary bearer establishment to the serving base station gNB2 through the relay UE, that is, the Remote UE first has an indirect link to transmit data with the network side.

[0438] Optionally, based on the remote UE having an indirect link, gNB1 can send the first information to the remote UE through the indirect link.

[0439] Exemplarily, the first information may include link measurement configuration, such as triggering conditions for neighbor cell measurement and measurement threshold, and the first measurement triggering condition in the above embodiment.

[0440] Step 111: When the link quality of the remote UE's direct link meets the link quality requirement, the remote UE sends link information of the direct link to gNB2 through an indirect link.

[0441] The link information of the direct link of the remote UE is the link information of the second communication link.

[0442] It can be understood that the above link quality requirement is determined according to the link measurement configuration in the first information.

[0443] Optionally, when the direct link satisfies the measurement trigger conditions configured by gNB2, for example, the RSRP from the Remote UE to the cell under gNB1 is greater than or equal to the first threshold, and the basic communication conditions of the Uu interface are met, the Remote UE can report the corresponding serving cell representation, the link measurement results of the direct link, etc. to the current Remote UE's serving base station gNB2.

[0444] Step 112: gNB2 receives link information of the direct link of the remote UE.

[0445] Optionally, the Remote UE's serving base station, gNB2, receives a report from the Remote UE and can determine the cell's location based on the reported serving cell information, typically a serving cell indicator such as the ECGI. If the cell is not managed by this base station, and based on inter-gNB interface interaction information, such as the Xn establishment process, it can be determined that the cell is a cell under neighboring gNB1. In this case, if gNB2 or gNB1 supports inter-gNB multi-path functionality, gNB2 can initiate a direct link addition procedure with gNB1.

[0446] Step 113: gNB2 sends a first request message to gNB1.

[0447] Optionally, gNB2 sends a first request message to gNB1 through an interface between base stations, such as an Xn interface, to initiate a direct link addition process for the Remote UE.

[0448] Optionally, the direct link addition process of the Remote UE can reuse the existing Xn interface signaling process, such as the S-NG-RAN node Addition Preparation process. A successful addition process can include S-NODE ADDITION REQUEST and S-NODE ADDITION REQUEST ACKNOWLEDGE signaling. A new field is added to the Request signaling to carry the information that this is a direct link addition in the presence of a relay indirect link. That is, the field added to the first request message can include information indicating the direct link addition in the presence of a relay indirect link.

[0449] Alternatively, a new Xn interface signaling process may be designed for the direct link adding process of the Remote UE.

[0450] For example, Multi-path Addition Preparation, such as Multi-path Addition Request and corresponding acknowledge signaling; or, M-NG-RAN node Addition Preparation process. The successful addition process includes M-NODE ADDITION REQUEST and M-NODE ADDITION REQUEST ACKNOWLEDGE signaling.

[0451] Alternatively, it may have other names and an appropriate signaling field to carry the information about the addition of a new direct link.

[0452] Optionally, the first request message, such as the add request message, may carry information including at least one or a combination of the following:

[0453] If the gNB1 where the direct link is located is added as an S-Node, that is, as a Secondary SCG node, the data carried in the first request message in Implementation 1 can basically be reused;

[0454] - If the gNB1 where the direct link is located is added as an M-Node, that is, as a Master MCG node, the information carried in the first request message should be different from that of an SCG node. The main difference is that if it is an SCG node, it is in a subordinate position, so the key, available DRB identifier, split PDU session, split RB and other information can be distributed by the MCG. If an MCG node is added, the entire service information and capability information of the Remote UE must be handed over to the MCG, and the MCG will perform the division between the MCG and SCG.

[0455] It should be noted that Implementation 2 involves adding a multi-path direct link. If the first request message uses the new Xn procedure and new signaling, this design already reflects the difference from the existing direct link addition operation. However, if SCG addition is multiplexed, the gNB1 node must be explicitly or implicitly informed that this direct link is a multi-path direct link addition.

[0456] Optionally, the explicit one is, for example, a dedicated field indicating that this is a direct link addition, and the implicit one is, for example, through a newly added configuration field, indicating that this is a direct link addition different from the original process.

[0457] Step 114: gNB1 receives the first request message.

[0458] Step 115. gNB1 sends a first response message to gNB2.

[0459] Optionally, after receiving the first request message, gNB1 can respond to the direct link addition process of the Remote UE through the interface between base stations, such as the Xn interface, that is, send a first response message to gNB2 through the interface between base stations.

[0460] Optionally, after receiving the first request message, such as the add request message, from the remote UE's current relay link serving base station gNB2, the remote UE's new serving base station gNB1 may respond. A successful response may include one or a combination of the following:

[0461] gNB1 accepts the services that the Remote UE needs to transmit via direct, allows multipath establishment, and configures the Remote UE.

[0462] -Generate configuration information for the Remote UE, which may include the Remote UE's end-to-end bearer configuration on gNB1, the Remote UE's bearer transmission information on the Uu interface (e.g., mapping information from the Remote UE RB identifier to the Remote UE Uu interface RLC bearer, information about newly added Remote UE Uu interface RLC bearers, etc.), and the Remote UE's basic configuration information on gNB1, such as serving cell information and PCell information;

[0463] -gNB1 sends the generated configuration information about the Remote UE, such as the first configuration, to gNB2 in a first response message, such as an S-NODE, M-NODE, or MULTI-PATH ADDITION REQUEST ACKNOWLEDGE message, or in an add request response message with another name.

[0464] Step 116. gNB2 receives the first response message.

[0465] Step 117: gNB2 sends the first configuration to the remote UE through the indirect link of the remote UE.

[0466] Optionally, after gNB2 receives the first response message from gNB1, when the first response message indicates that gNB1 has successfully accepted the Remote UE and can provide transmission services for it, the configuration information (such as the first configuration) of gNB1 for the Remote UE is sent to the Remote UE through an RRC reconfiguration message, that is, the first configuration is carried in the RRC reconfiguration message.

[0467] Step 118: The remote UE receives the first configuration.

[0468] Step 119: The remote UE establishes a direct link to the remote UE based on the first configuration.

[0469] Optionally, after receiving the reconfiguration message, the Remote UE can establish a new direct link to gNB1 and the original indirect link to gNB2 according to the cell identifier of the remote UE in gNB1 and the first configuration, such as the configuration information of gNB1, to form a multi-path to the network side and jointly perform its own service transmission.

[0470] It should be noted that for a newly added or established direct link for a remote UE, the configuration and transmission are generated and controlled by gNB1. The specific configuration information is sent by gNB1 to gNB2, and then by gNB2 to the remote UE via RRC. If the remote UE's configuration completion signaling is returned to gNB2 (when the primary transmission channel of SRB1 is still the indirect link), a method is required to notify gNB1 that the remote UE has established the direct link according to the configuration and that subsequent data transmission is possible. The notification methods include one or a combination of the following:

[0471] - After receiving the Configuration Complete message from the Remote UE, gNB2 indicates to gNB1 that the Remote UE has successfully established the direct link according to the configuration requirements;

[0472] - The Remote UE sends an RRC message via the newly established SRB bearer to gNB1, such as SRB3, to inform gNB1 that it has successfully established a direct link.

[0473] -The Remote UE reconfigures the primary or sole path to the SRB1 bearer of gNB1 and sends an RRC Reconfiguration Complete message to inform gNB1 that it has successfully established the direct link.

[0474] The Remote UE performs a successful non-contention or contention random access procedure to gNB1 through a Layer 2 procedure, such as a random access procedure. When gNB1 identifies the Remote UE, it knows that a direct link has been successfully established.

[0475] - The Remote UE sends any data, which can be SRB data or DRB data, through the newly established path to gNB1. When gNB1 receives the data, it can be considered that the Remote UE direct link is successfully established;

[0476] It should also be noted that in the architecture shown in Figure 5, although the indirect link is established first, the PCell in the direct link is more important due to its shorter transmission hop count and its inherent configuration attributes similar to those of a traditional Uu interface link. Since the indirect link primarily configures the PC5 interface link for the remote UE and does not require direct cell group or PCell configuration to gNB2, the model that can be adopted is that the PCell in the direct link is the PCell of the remote UE, and the PCell failure and recovery behaviors can be reused. The remote UE's SRB1 can also reconfigure the direct link as the sole or primary path. In the event of a direct link failure, the behavior for an MCG failure is followed. Since an indirect link failure does not affect SRB1 transmission, a more gentle recovery approach can be adopted, such as simply reporting via UE Assistance Information or SCG Failure Information and waiting for network processing without affecting data transmission. That is, with the addition of a direct link, the PCell and at least the SRB1 path are reconfigured simultaneously, reconfiguring the primary path from indirect to direct link. Alternatively, the SRB1 path can be retained on the indirect link to avoid reconfiguration. In this case, indirect link failures are handled similarly to MCG failures, while direct link failures are handled using a gentle escalation process.

[0477] It should be noted that the above implementations 1 and 2 use the addition of a second link across gNBs as an example to illustrate the multipath establishment process. In practice, inter-gNB path modification or path release also involves similar Xn interface and air interface processes, and are not further illustrated here.

[0478] In this way, in the above-mentioned implementation method 1 and implementation method 2, multi-path transmission can be established for the Remote UE when the Remote UE and the relay UE belong to different serving base stations, thereby ensuring the data transmission effect of the Remote UE, thereby improving the UE experience and system efficiency while ensuring data transmission.

[0479] Another possible implementation manner: the first network node and the second network node are the same third CU, or different first CU and second CU.

[0480] It is understandable that if the network-side access network node is not a gNB but is split into CU-DU nodes, the addition of a second communication link to the remote UE will affect the CU-DU interface process. However, in principle, the CU-DU structure does not affect UE behavior and can be transparent to the UE.

[0481] In conjunction with Figure 7, Figure 7 shows a typical inter-DU multi-path architecture. In communication architecture 2, the remote UE can establish a direct link with CU1 through DU1, and can establish an indirect path with CU1 through the relay UE and DU2. In this scenario, since two DU nodes are spanned, the link establishment process and the information details carried during the link establishment process will be significantly different from those when a single DU node is used. It can be seen that in the architecture shown in Figure 7, the first network node and the second network node are both the third CU.

[0482] Implementation method 3, adding an inter-DU indirect link, provides the process and details of how the Remote UE adds an inter-DU indirect link based on the existing direct link.

[0483] In conjunction with Figure 5 , in implementation 3, the first network node and the second network node are both CUs in Figure 5 . As shown in Figure 12 , implementation 3 may include the following steps:

[0484] Step 120: The CU sends first information to the remote UE through the direct link of the remote UE.

[0485] Optionally, assuming that the Remote UE has a data transmission requirement and the Uu interface link meets the communication requirements, the Remote UE can first follow the existing process to establish a connection and necessary bearer establishment between DU1 and CU, that is, the Remote UE first has a direct link to transmit data with the network side.

[0486] It can be understood that in implementation mode 3, the direct link of the remote UE is a link established between the remote UE and the CU through DU1.

[0487] Optionally, on the basis that the remote UE has a direct link, the CU may send the first information to the remote UE through the direct link.

[0488] For example, the first information may include a link measurement configuration, so that the remote UE can search for available relay UEs around the remote UE based on the link measurement configuration configured by the CU. For example, the link measurement configuration may include measurements of PC5 interface, WiFi, or Bluetooth.

[0489] Exemplarily, the CU may instruct the Remote UE in a dedicated signaling or public signaling manner to allow it to report information of the relay UE having an ideal backhaul condition with the Remote UE, that is, the first information is dedicated signaling or public signaling.

[0490] Step 121: The remote UE receives first information.

[0491] Step 122: When the link quality of the indirect link of the remote UE meets the link quality requirement, the remote UE sends link information of the indirect link to the CU through the direct link.

[0492] Optionally, the CU is a serving base station of the remote UE.

[0493] Optionally, when the indirect link of the remote UE satisfies the measurement trigger conditions configured by the CU (i.e., the measurement trigger conditions that may be included in the link measurement configuration, such as the first measurement trigger condition in the above embodiment), for example, when the measurement results of the PC5 interface, WiFi, or Bluetooth link meet the basic communication threshold, the Remote UE may report the corresponding relay UE identification information (or the relay UE's serving cell information), the link measurement results of the indirect link, etc., to the serving CU of the Remote UE. Alternatively, when the Remote UE meets the ideal backhaul condition with the relay UE, it may report the relay UE identification information and the relay UE's serving cell information, etc., to its own serving CU.

[0494] The following further illustrates step 82 by taking the communication interface between the remote UE and the relay UE as an example.

[0495] (1) PC5 interface. If it is a PC5 interface, that is, the SL link between the remote UE and the relay UE is an SL link based on the PC5 interface, the relay UE and the Remote UE need to exchange information about each other's requirements and capabilities for SL relay through the PC5 discovery process. For example, what services (such as relay service code) related transit or relay services does the Remote UE need to be provided with, what services (such as relay service code corresponding to the relay UE) related transit or relay services can or are capable of providing, etc. Only when the services supported by the relay UE match the service requirements of the remote UE, and the link quality between the Remote UE and the relay UE meets the threshold requirement (such as the first threshold mentioned above), for example, SD-RSRP or SL-RSRP is higher than a certain threshold, in this case, it means that the relay UE meets the conditions for providing relay services to the Remote UE, so that the remote UE can report to the CU.

[0496] When the PC5 interface is used between two UEs, the relay UE identification information reported by the remote UE is generally the relay UE's SL Layer-2 identification. In addition, the remote UE can obtain the relay UE's serving cell information through the interaction of the discovery process and report it to its own serving CU.

[0497] (2) Wired link interface. Ideal backhaul is defined between the remote UE and the relay UE. Because ideal backhaul typically involves a direct connection between the remote UE and relay UE via a wired link, such as an optical fiber, link quality measurement and reporting of link measurement results are not required. The only requirement for ideal backhaul is that the two UEs have a direct optical fiber connection. If the remote UE meets these conditions, i.e., is connected to another UE via a wired link, the remote UE can directly report information about the relay UE to its serving CU.

[0498] Generally speaking, it is necessary to report the relay UE's identification information, which can be the relay UE's C-RNTI, IMSI, S-TMSI, I-RNTI, or other identification information, or local identification information selected by the remote UE for the relay UE. Furthermore, the two UEs need to inform the remote UE of the relay UE's serving cell information through the wired interface between the UEs, and the remote UE will report the information to its own serving CU.

[0499] (3) Non-3GPP interface. The non-3GPP interface may include: WiFi interface or Bluetooth, etc. When the Remote UE detects that there is an available relay UE nearby and can provide relay services for itself through non-3GPP transmission such as WiFi or Bluetooth between UEs, generally speaking, it is also necessary to meet the basic link quality requirements between the two UEs, such as the communication link quality requirements, for example, the received signal strength is higher than a certain threshold. For relay UEs that meet the conditions, the Remote UE needs to report the identification information of the relay UE, which can be the C-RNTI, IMSI, S-TMSI, I-RNTI and other identifiers of the relay UE, or the local identification information selected by the Remote UE for the relay UE, etc., and the two UEs also need to inform the Remote UE of the service cell information of the relay UE through the non-3GPP interface between the UEs, and the Remote UE reports it to its own service CU together.

[0500] Step 123: The CU receives link information of the indirect link of the remote UE.

[0501] Optionally, the serving CU of the Remote UE receives a report from the Remote UE and can make a judgment based on the serving cell information of the relay UE in the received link information, which is generally a serving cell identifier, such as ECGI. If it is not the cell under the current Remote UE serving DU1, and based on the interface interaction information between CU and DU, such as the F1 establishment process, it can be judged to be a cell under the neighboring DU2. At this time, if at least one of DU1 and DU2 supports the inter-DU multi-path function, the CU can initiate the Remote UE-related indirect link addition process to DU2.

[0502] Step 124: CU sends a second request message to DU2.

[0503] Among them, DU2 is the DU corresponding to the second communication link, that is, the indirect link. The second request message can be used to request the transmission configuration of the remote UE that is responsible for DU2 in the second communication link, and the second request message can include the second configuration, and the second configuration can include the E2E bearer configuration of the remote UE in the CU.

[0504] Optionally, the above-mentioned E2E bearer configuration may include: a list of SRBs and DRBs of the remote UE in the CU and attribute information, for example, it may include some configurations of the PDCP layer and above layers.

[0505] Optionally, the CU sends a second request message to the DU2 through an interface between the CU and the DU, such as the F1 interface, to initiate an indirect link adding process related to the Remote UE.

[0506] Optionally, the indirect link addition process related to the Remote UE can reuse the existing F1 interface signaling process, such as the UE Context Setup process. A successful addition process includes the CU sending a UE CONTEXT SETUP REQUEST message and receiving a UE CONTEXT SETUP RESPONSE message sent by the DU2, or a new signaling process is used to establish the Remote UE's own indirect link configuration.

[0507] Because the DU is only responsible for processing protocol layers below PDCP, for the remote UE's indirect link, the Uu interface's SRAP, RLC, MAC, and PHY protocol layers are located in DU2, and these protocol layers belong to the relay UE. The remote UE is associated with DU2, which can configure for the remote UE: the mapping between the remote UE's E2ERB in the CU and the remote UE's PC5 interface RLC channel, as well as the newly established PC5 interface RLC channel for the indirect link.

[0508] Optionally, the CU can use the UE Context Setup or UE Context Modification process to send a second request message from the CU to DU2 to request DU2 to add a new PC5 interface RLC channel configuration for the Remote UE, as well as the mapping relationship between the configured PC5 interface RLC channel and the Remote UE E2E RB, which is equivalent to opening up the transmission channel and configuration between the Remote UE and the relay UE.

[0509] Step 125: DU2 receives the second request message.

[0510] Step 126: DU2 sends a second response message to CU.

[0511] Step 127: The CU receives the second response message.

[0512] The second response message may include the third configuration and the result of DU2 accepting the second configuration.

[0513] The second communication link is an indirect link of the remote UE, so the third configuration may include a transmission configuration on the PC5 interface configured by DU2 for the remote UE.

[0514] Optionally, the transmission configuration configured by the remote UE on the PC5 interface may include: configuration of the PC5 interface RLC channel, and a mapping relationship between the SRB and DRB accepted by DU2 and its configured PC5 RLC channel.

[0515] Optionally, DU2 sends a second response message to the CU through an interface between the CU and DU, such as the F1 interface, to respond to the UE context establishment process related to the Remote UE.

[0516] Optionally, for the second request message, such as the UE SETUP REQUEST message of the Remote UE, the message may carry a list of SRBs and DRBs and attribute information, for example, it may include some configurations of the PDCP and above layers. DU2 determines whether these SRBs and DRBs can be accepted. If the acceptance is successful, DU2 may return the list of SRBs and DRBs that have been successfully accepted in the second response message. And because these RBs are not directly transmitted on the Uu interface, for example, for the Remote UE, they are carried on the PC5 interface, so DU2 needs to provide the configuration of the PC5 interface RLC channel, as well as the mapping relationship between the SRBs and DRBs accepted by DU2 and the PC5 RLC channel configured by it.

[0517] Step 128: CU sends a third request message to DU2.

[0518] Among them, the third request message can be used to request the transmission configuration of the relay UE responsible for DU2 in the indirect link of the remote UE, and the third request message can include the fourth configuration, and the fourth configuration can include the E2E bearer configuration of the remote UE in the fourth CU.

[0519] Optionally, the fourth configuration may include: a list of SRBs and DRBs of the remote UE in the fourth CU and attribute information, for example, may include some configurations of the PDCP layer and above layers.

[0520] Optionally, the third request message may be a request message in a UE Context Modification or UE Context SETUP process.

[0521] Step 129: DU2 receives the third request message.

[0522] Optionally, after DU2 receives the second request message, DU2 can add a new Uu interface RLC channel configuration for the relay UE, and configure the mapping relationship between the Uu interface RLC channel and the third configuration; and / or, request DU2 to add a new PC5 interface RLC channel configuration for the relay UE, and configure the mapping relationship between the PC5 RLC channel and the E2E RB of the Remote UE in the CU, which is equivalent to opening up the transmission channel between DU2 and the relay UE, and between the relay UE and the Remote UE for transferring the Remote UE.

[0523] Exemplarily, the CONTEXT SETUP REQUEST message for the relay UE may carry a fourth configuration, such as a list of SRBs and DRBs of the Remote UE and attribute information (for example, it may include some configurations of the PDCP and above layers). DU2 determines whether it can accept these SRBs / DRBs. If the acceptance is successful, the list of successfully accepted SRBs and DRBs is returned in a third response message, such as CONTEXT SETUP Response. Because these successfully accepted RBs involve two air interfaces for the relay UE, for the relay UE, DU2 needs to provide the transmission configuration of the relay UE on the PC5 interface and the Uu interface, such as the configuration of the Uu interface RLC channel and the PC5 interface RLC channel, and the mapping relationship between the SRB / DRB and the Uu interface RLC channel and the PC5 interface RLC channel configured by DU2.

[0524] Step 130: DU2 sends a third response message to CU.

[0525] Step 131: The CU receives the third response message.

[0526] The third response message may include the fifth configuration and the result of DU2 accepting the fourth configuration.

[0527] The fifth configuration may include the transmission configuration configured by DU2 for the relay UE on the PC5 interface and the Uu interface.

[0528] Optionally, DU2 may send a third response message to the CU via an interface between the CU and DU, such as the F1 interface, to respond to a UE context establishment or modification process related to the Remote UE, to ensure that the indirect link of the Remote UE can be established.

[0529] Generally, the relationship between CU and DU is one of control and control. Therefore, after CU instructs DU to complete relevant configuration, it needs to send RRC reconfiguration signaling to the relay UE. The reconfiguration signaling may mainly include the addition of Uu RLC channel of relay UE, the mapping relationship between Uu RLC channel and Remote UE E2E RB, the addition of PC5 RLC channel, and the mapping relationship between PC5 RLC channel and Remote UE E2E RB.

[0530] Step 132: The CU sends a first configuration to the remote UE through the remote UE's direct link.

[0531] Optionally, the first configuration may include: transmission configuration of the remote UE at the PC5 interface.

[0532] Optionally, when CU receives a third response message from DU2, such as a response confirmation message, when DU2 successfully completes the update configuration of the Remote UE and relay UE, it can send RRC reconfiguration information to the Remote UE. The main content may include the addition of the PC5 interface RLC channel of the Remote UE, and the mapping relationship between the PC5 interface RLC channel and the Remote UE E2E RB, etc.

[0533] Optionally, the timing for the CU to send the second request message and the third request message is not limited.

[0534] Step 133: The remote UE receives the first configuration.

[0535] Step 134: The remote UE establishes an indirect link to the remote UE based on the first configuration.

[0536] Optionally, the Remote UE receives the reconfiguration information and establishes a new indirect link to DU2 through the relay UE and the original direct link to CU1 according to the relay UE identifier and the first configuration, forming a multipath to the network side for its own service transmission.

[0537] Alternatively, when both DUs reside within the same CU, since both the remote UE's and the relay UE's RRC signaling terminate at the same CU node, the CU node clearly understands that both UEs have completed the indirect link reconfiguration process, allowing the CU to send data over the indirect link. Regarding the PCell and SRB1 primary path, a simpler model can be employed: the PCell is always defined as the PCell within direct link DU1, and the SRB1 primary path is configured over the direct link.

[0538] It should be noted that Implementation 3 uses two DU nodes located in the same CU as an example to illustrate the basic process. If the two DU nodes are located in different CUs, the more complex situation involves not only the CU-DU interface but also the Xn interface. This is equivalent to requiring a combination of Implementation 1 and Implementation 3. To avoid repetition, this is not repeated here.

[0539] Optionally, in actual implementation, the CU may request the transmission configuration of both the relay UE and the remote UE from DU2 through a request message. DU2 may then return the configured transmission configuration of both the relay UE and the remote UE, as well as its acceptance result of the relevant bearer configuration, to the CU through a response message, for example, by adopting a new F1 interface signaling process.

[0540] Implementation method 4: Adding inter-DU direct link, which provides the process and details of how the Remote UE adds a direct link across DUs based on the existing indirect link.

[0541] In conjunction with Figure 5 , in implementation 4, the first network node and the second network node are both CUs in Figure 5 . As shown in Figure 13 , implementation 4 may include the following steps:

[0542] Step 135: The CU sends first information to the remote UE through the indirect link of the remote UE.

[0543] Optionally, assuming that the Remote UE has a need for data transmission and the current indirect link through the relay meets the communication requirements, for example, the Uu interface RSRP of the Remote UE is lower than the threshold, while the relay UE meets the Uu interface RSRP threshold condition as a relay, and the PC5 interface RSRP between the relay UE and the Remote UE is higher than a certain threshold to meet the communication requirements; therefore, the Remote UE can first establish a connection and necessary bearer establishment with the CU through the relay UE and service DU2 according to the existing process, that is, the Remote UE first has an indirect link to transmit data with the network side.

[0544] It can be understood that in implementation mode 4, the indirect link of the remote UE is a link established between the remote UE and the CU through DU2.

[0545] Optionally, on the basis that the remote UE has a direct link, the CU may send the first information to the remote UE through the direct link.

[0546] Exemplarily, the first information may include link measurement configuration, such as neighbor cell measurement and threshold.

[0547] Step 136: The remote UE receives the first information.

[0548] Step 137: When the link quality of the direct link of the remote UE meets the link quality requirement, the remote UE sends the link information of the direct link to the CU through the indirect link.

[0549] Optionally, when the direct link meets the measurement trigger conditions configured by the CU, for example, the RSRP from the Remote UE to the cell under DU1 is higher than the threshold and the basic Uu interface communication conditions are met, the Remote UE can report the corresponding serving cell identification information, link measurement results, etc. to the serving CU of the current Remote UE;

[0550] Step 138: The CU receives link information of the direct link of the remote UE, that is, link information of the second communication link.

[0551] Optionally, the serving CU of the Remote UE receives a report from the Remote UE and can make a judgment based on the reported serving cell information, which is generally the serving cell identifier, such as ECGI. If it is not a cell managed by the current DU2, and based on the interface interaction information between the CU and DU, such as the F1 establishment process, it can be determined to be a cell under the neighboring DU1. At this time, if DU2 and / or DU1 support the inter-DU multi-path function, the CU can initiate the relevant process of adding a direct link to DU1.

[0552] Step 139: CU sends a second request message to DU1.

[0553] Among them, DU1 is the DU corresponding to the second communication link, and the second request message can be used to request the transmission configuration of the remote UE that is responsible for DU1 in the second communication link, and the second request message can include the second configuration, and the second configuration can include the E2E bearer configuration of the remote UE in the CU.

[0554] Optionally, the CU may send a second request message to the DU1 through an interface between the CU and the DU, such as the F1 interface, to initiate a process related to adding a direct link of the Remote UE.

[0555] Optionally, the Remote UE's direct link addition-related procedures can reuse existing F1 interface signaling procedures, such as the UE Context Setup procedure (a successful procedure includes UE CONTEXT SETUP REQUEST and UE CONTEXT SETUP RESPONSE signaling), or use new signaling procedures to establish the Remote UE's own direct link configuration. Since the DU is only responsible for processing protocol layers below PDCP, for the Remote UE's direct link, the Uu interface SRAP / RLC / MAC / PHY protocol layers are located in DU2, and these protocol layers belong to the Remote UE. Therefore, the Remote UE associated with DU2 needs to configure the mapping relationship between the E2E RB and the Uu interface RLC channel, as well as the newly established Uu interface RLC channel for the direct link.

[0556] Optionally, after the CU sends the second request message to DU1, DU1 may receive the second request message.

[0557] Step 140: DU1 sends a second response message to CU.

[0558] The second response message may include the third configuration and the acceptance result of the first DU for the second configuration. The third configuration may include the transmission configuration on the Uu interface configured by the first DU for the remote UE.

[0559] Optionally, DU1 sends a third response message to the CU via an interface between the CU and the DU, such as the F1 interface, to respond to the UE context establishment process related to the direct link addition of the Remote UE.

[0560] Optionally, after DU1 sends the second request message to CU, the CU may receive a second response message.

[0561] Step 141: The CU sends a first configuration to the remote UE through an indirect link of the remote UE.

[0562] Optionally, the CU receives the response confirmation information of DU1. When DU1 successfully configures the Remote UE to provide transmission services for the remote UE, the CU sends the updated direct link configuration (which may include bearer mapping and cell-related configuration, etc.) to the Remote UE through RRC reconfiguration signaling, that is, sends the first configuration to the remote UE.

[0563] Optionally, the remote UE may receive the first configuration.

[0564] Step 142: The remote UE establishes a direct link to the remote UE based on the first configuration.

[0565] Optionally, the remote UE receives the reconfiguration information and establishes a new direct link through DU1 and the original indirect link through DU2 according to the cell identifier and configuration information, forming a multi-path to the network side to jointly transmit its own services.

[0566] Alternatively, when both DUs reside within the same CU, the Remote UE's RRC signaling terminates at the CU node. Therefore, the CU node clearly understands that the Remote UE has completed the direct link reconfiguration process and can therefore send data over the direct link. Regarding the PCell and SRB1 primary path, a simpler model can still be adopted: the PCell is always defined as the PCell within direct link DU1, and the SRB1 primary path is configured over the direct link.

[0567] It should be noted that the above implementation method 4 takes the two DU nodes involved in the two links of the UE as an example and describes the basic process. If the two DU nodes are located in different CUs, as shown in the architecture of Figure 6, not only the CU-DU interface but also the Xn interface is involved, which is equivalent to the need for implementation methods 2 and 4 to be combined. To avoid repetition, they will not be repeated here.

[0568] Optionally, when the second communication link is an indirect link for the remote UE, the above embodiment is described in detail primarily based on communication between the remote UE and the relay UE via the PC5 interface. In actual implementation, when the remote UE and the relay UE are connected via a non-3GPP interface or a wired connection, such as an optical fiber connection, the second network node needs to configure transmission configuration for the relay UE on the Uu interface. For the remote UE, it can configure which E2E RBs are allowed to be transmitted on the indirect link; the rest can be implemented by the UE.

[0569] For example, the transmission configuration of the relay UE on the Uu interface may include a Uu RLC channel and a mapping relationship between the Uu RLC channel and the E2E RB of the Remote UE.

[0570] The present invention provides a method for establishing SL relay multi-path across nodes, so that the Remote UE and the relay UE can still establish multi-path transmission for the Remote UE when they belong to different serving base stations, ensuring the data transmission effect of the Remote UE, thereby improving the UE experience and system efficiency while ensuring data transmission.

[0571] Combined with the statements of implementation methods 1 to 4 above, it can be seen that the SL multi-path establishment method provided in the embodiment of the present application can enable the Remote UE to be better compatible with cross-node scenarios when it is in a multi-path scenario and has a PC5 interface or an ideal interface or even a non-3GPP interface (such as WiFi, Bluetooth, etc.) with the relay UE. When the relay UE and the Remote UE are in different service nodes, the process problems of management processes such as multi-path addition and establishment are solved, which not only ensures the multi-path experience of the Remote UE but also improves the scenario compatibility. On the basis of ensuring the UE service experience, the system efficiency is further improved.

[0572] It should be noted that, in the above embodiment, the SL multi-link establishment method provided by the embodiment of the present application is described by taking the case where the first communication link and the second communication link are different, which may include: the first communication link is an indirect link of the remote UE, and the second communication link is a direct link of the remote UE; or the first communication link is a direct link of the remote UE, and the second communication link is an indirect link of the remote UE as an example. In actual implementation, the SL multi-link establishment method provided by the embodiment of the present application can also be used in the scenario where the first communication link and the second communication link are both indirect links of the remote UE, that is, the specific scheme for the remote UE to establish the second communication link can be used in this scenario. In order to avoid repetition, it will not be repeated here.

[0573] It can be understood that the above-mentioned method embodiments, or various possible implementation methods in each method embodiment can be executed separately, or, under the premise that there is no contradiction, can also be executed in combination with each other. The specific implementation can be determined according to actual usage requirements, and the embodiments of the present application do not limit this.

[0574] The embodiment of the present application provides a SL multi-path establishing device. As shown in FIG14 , the SL multi-path establishing device 1400 provided by the embodiment of the present application may include: a receiving module 1401 and an establishing module 102;

[0575] Receiving module 1401 may be configured to receive a first configuration sent by a first network node via a first communication link, where the first communication link is a communication link between a remote UE and the first network node, and the first configuration may be used to establish a second communication link between the remote UE and a second network node;

[0576] The establishing module 1402 may be configured to establish a second communication link based on the first configuration received by the receiving module 1401;

[0577] The communication link is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link.

[0578] Optionally, the device may further include a sending module;

[0579] The sending module may be configured to send link information of the second communication link to the first network node through the first communication link before the receiving module receives the first configuration sent by the first network node through the first communication link.

[0580] Optionally, the sending module can be used to:

[0581] When the link quality of the second communication link meets the link quality requirement, the remote UE sends link information of the second communication link to the first network node through the first communication link;

[0582] The link quality requirement may include at least one of the following:

[0583] The link measurement result of the communication link meets the first measurement trigger condition;

[0584] There is an ideal backhaul condition between the relay UE and the remote UE in the communication link.

[0585] Optionally, the receiving module may be further configured to receive first information sent by the first network node through the first communication link before the sending module sends link information of the second communication link to the first network node through the first communication link;

[0586] The first information may include at least one of the following:

[0587] Link measurement configuration, where the link measurement configuration may include a first measurement triggering condition;

[0588] The first indication information may be used to instruct the remote UE to report information of the relay UE having an ideal backhaul condition with the remote UE.

[0589] Optionally, the first measurement triggering condition may include at least one of the following:

[0590] The link quality between the remote UE and the relay UE is greater than or equal to a first threshold;

[0591] A received signal quality RSRP from the remote UE to the cell in the second network node is greater than or equal to a second threshold.

[0592] Optionally, the first network node and the second network node are different access network nodes;

[0593] Alternatively, the first network node is a first centralized unit CU, and the second network node is a second CU;

[0594] Alternatively, the first network node and the second network node are both third CUs.

[0595] Optionally, the first network node and the second network node are different access network nodes; or, the first network node is a first CU, and the second network node is a second CU;

[0596] The apparatus may further include an execution module, which may be configured to execute at least one of the following after the creation module establishes the second communication link based on the first configuration:

[0597] The remote UE sends a first message to the first network node;

[0598] The remote UE sends a second message or arbitrary data to the second network node through the second communication link;

[0599] The remote UE initiates an access process to the second network node;

[0600] The first message and the second message can be used to notify the remote UE that the second communication link has been successfully established; the second message may include any one of the following: an RRC message carried on the signaling radio bearer SRB of the second communication link, and an RRC reconfiguration completion message.

[0601] Optionally, the link information of the second communication link may include at least one of the following:

[0602] Relevant information of the relay UE in the first communication link;

[0603] Serving cell information of remote UE;

[0604] The relevant information of the relay UE may include at least one of the following: identification information of the relay UE and serving cell information of the relay UE.

[0605] Optionally, the first configuration may include at least one of the following:

[0606] End-to-end E2E bearer configuration of the remote UE at the second network node;

[0607] Transmission configuration of the remote UE on the PC5 interface;

[0608] Transmission configuration of the remote UE on the Uu interface;

[0609] The basic configuration of the remote UE may include at least one of the cell information and relay UE information configured by the second network node for the remote UE.

[0610] The SL multipath establishment device in the embodiments of the present application can be an electronic device, such as an electronic device with an operating system, or a component of an electronic device, such as an integrated circuit or chip. The electronic device can be a terminal or other device other than a terminal. For example, the terminal can include, but is not limited to, the types of terminal 11 listed above, and the other device can be a server, a network attached storage (NAS), etc., which is not specifically limited in the embodiments of the present application.

[0611] The embodiments of the present application provide various processes implemented by the remote UE in the method embodiments of Figures 4 to 13 and achieve the same technical effects. To avoid repetition, they are not described here.

[0612] The embodiment of the present application provides an SL multi-path establishment device. As shown in FIG15 , the SL multi-path establishment device 1500 provided by the embodiment of the present application may include: a sending module 1501;

[0613] The sending module 1501 may be configured to send a first configuration to a remote UE via a first communication link, where the first communication link is a communication link between the remote UE and a first network node, and the first configuration may be used to establish a second communication link between the remote UE and a second network node;

[0614] The communication link is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link.

[0615] Optionally, the first network node and the second network node are different access network nodes;

[0616] Alternatively, the first network node is a first CU and the second network node is a second CU;

[0617] Alternatively, the first network node and the second network node are both third CUs.

[0618] Optionally, the first configuration may include at least one of the following:

[0619] End-to-end E2E bearer configuration of the remote UE at the second network node;

[0620] Transmission configuration of the remote UE on the PC5 interface;

[0621] Transmission configuration of the remote UE on the Uu interface;

[0622] The basic configuration of the remote UE may include at least one of the cell information and relay UE information configured by the second network node for the remote UE.

[0623] Optionally, the device may further include a receiving module;

[0624] The receiving module may be configured to receive link information of a second communication link sent by the remote UE through the first communication link before the sending module sends the first configuration to the remote UE through the first communication link.

[0625] Optionally, the link information of the second communication link may include at least one of the following:

[0626] Relevant information of the relay UE in the first communication link;

[0627] Serving cell information of remote UE;

[0628] The relevant information of the relay UE may include at least one of the following: identification information of the relay UE and serving cell information of the relay UE.

[0629] Optionally, the first network node and the second network node are different access network nodes; or, the first network node is a first CU, and the second network node is a second CU;

[0630] The sending module may also be configured to send a first request message to the second network node before sending the first configuration to the remote UE through the first communication link, where the first request message may be used to request adding a second communication link;

[0631] The receiving module may also be configured to receive a first response message sent by the second network node. The first response message may be used to indicate that the second network node supports providing a transmission service for the remote UE, and the first response message may include a first configuration.

[0632] Optionally, the first request message may include at least one of the following:

[0633] Security-related information of the remote UE;

[0634] Communication information of remote UE;

[0635] PDU session information offloaded by the remote UE to the second network node;

[0636] Data radio bearer (DRB) identification information supported by the second network node;

[0637] Cell group configuration for remote UE;

[0638] RB information of the offloaded bearer of the remote UE;

[0639] Protection rate information of the remote UE;

[0640] Primary cell information of the remote UE;

[0641] Relevant information of the relay UE in the second communication link;

[0642] Service information and capability information of the remote UE.

[0643] Optionally, the first network node and the second network node are different access network nodes; or, the first network node is a first CU, and the second network node is a second CU;

[0644] The apparatus may further include a receiving module;

[0645] The receiving module may be configured to receive a first message sent by the remote UE after the sending module sends the first configuration to the remote UE through the first communication link, where the first message may be used to notify the remote UE that the second communication link has been successfully established;

[0646] The sending module may also be configured to send a third message to the second network node, where the third message may be used to notify the remote UE that the second communication link has been successfully established.

[0647] Optionally, the sending module may be further configured to send first information to the remote UE through the first communication link before sending the first configuration to the remote UE through the first communication link;

[0648] The first information may include at least one of the following:

[0649] Link measurement configuration, where the link measurement configuration may include a first measurement triggering condition;

[0650] The first indication information may be used to instruct the remote UE to report information of the relay UE having an ideal backhaul condition with the remote UE.

[0651] The SL multi-path establishment device in the embodiment of the present application can be a network side device, such as an access network device (such as gNB) or a CU.

[0652] The embodiments of the present application provide various processes implemented by the first network node in the method embodiments of Figures 4 to 13 and achieve the same technical effects. To avoid repetition, they are not described here.

[0653] The embodiment of the present application provides a SL multi-path establishment device. As shown in FIG16 , the SL multi-path establishment device 1600 provided by the embodiment of the present application may include: a sending module 1601;

[0654] A sending module 1601 may be configured to send a first configuration, where the first configuration may be used to establish a second communication link between a remote UE and a second network node; the second communication link is different from the first communication link of the remote UE; the first communication link is a communication link between the remote UE and the first network node, and the first communication link may be used by the first network node to send the first configuration to the remote UE;

[0655] The communication link is a direct link or an indirect link of the remote UE.

[0656] Optionally, the first network node and the second network node are different access network nodes;

[0657] Alternatively, the first network node is a first CU and the second network node is a second CU;

[0658] Alternatively, the first network node and the second network node are both third CUs.

[0659] Optionally, the first network node and the second network node are different access network nodes; or, the first network node is a first CU and the second network node is a second CU; the apparatus may further include a receiving module;

[0660] A receiving module, which may be used to receive a first request message sent by a first network node, where the first request message may be used to request adding a second communication link;

[0661] The sending module may be specifically configured to send a first response message to the first network node, where the first response message may include a first configuration.

[0662] Optionally, the first request message may include at least one of the following:

[0663] Security-related information of the remote UE;

[0664] Communication information of remote UE;

[0665] PDU session information offloaded by the remote UE to the second network node;

[0666] Data radio bearer (DRB) identification information supported by the second network node;

[0667] Cell group configuration for remote UE;

[0668] RB information of the offloaded bearer of the remote UE;

[0669] Protection rate information of the remote UE;

[0670] Primary cell information of the remote UE;

[0671] Relevant information of the relay UE in the second communication link;

[0672] Service information and capability information of the remote UE.

[0673] Optionally, the device may further include an execution module;

[0674] The execution module may also be configured to, after the receiving module receives the first request message sent by the second network node and received by the first network node, perform at least one of the following:

[0675] The second network node accepts the first service and generates configurations for the remote UE and the first relay UE;

[0676] The second network node sends an RRC reconfiguration message to the first relay UE, where the RRC reconfiguration message may include at least one of information about the first service and relevant information about the first relay UE;

[0677] The second network node generates a configuration of the remote UE;

[0678] The second network node accepts the first service and generates a configuration for the remote UE;

[0679] The first service is a service that the remote UE needs to transmit through the second communication link, and the first relay UE is a relay UE in the second communication link.

[0680] Optionally, the first network node and the second network node are both third CUs;

[0681] The sending module can be specifically configured to send the first configuration to the remote UE via the first communication link.

[0682] Optionally, the device may further include a receiving module;

[0683] The sending module may also be configured to send a second request message to the first DU, where the device is a second CU or a third CU; the first DU is a DU corresponding to the second communication link, and the second request message may be used to request a transmission configuration of a remote UE that is responsible for the first DU in the second communication link, and the second request message may include a second configuration, and the second configuration may include an E2E bearer configuration of the remote UE in the fourth CU;

[0684] a receiving module, configured to receive a second response message sent by the first DU, where the second response message may include the third configuration and an acceptance result of the first DU to the second configuration;

[0685] The second communication link is a direct link of the remote UE, and the third configuration may include the transmission configuration on the Uu interface configured by the first DU for the remote UE; or, the second communication link is an indirect link of the remote UE, and the third configuration may include the transmission configuration on the PC5 interface configured by the first DU for the remote UE.

[0686] Optionally, the second communication link is an indirect link of the remote UE; optionally, the apparatus may further include a receiving module;

[0687] The sending module may also be configured to send a third request message to the first DU, where the device is a second CU or a third CU; the first DU is a DU corresponding to the second communication link, and the third request message may be used to request a transmission configuration of a relay UE that is responsible for the first DU in the second communication link, and the third request message may include a fourth configuration, which may include an E2E bearer configuration of the remote UE in the fourth CU;

[0688] a sending module, configured to receive a third response message sent by the first DU, where the third response message may include the fifth configuration and an acceptance result of the first DU to the fourth configuration;

[0689] The fifth configuration may include the transmission configuration on the PC5 interface and the Uu interface configured by the first DU for the relay UE.

[0690] Optionally, the first configuration may include at least one of the following:

[0691] End-to-end E2E bearer configuration of the remote UE at the second network node;

[0692] Transmission configuration of the remote UE on the PC5 interface;

[0693] Transmission configuration of the remote UE on the Uu interface;

[0694] The basic configuration of the remote UE may include at least one of the cell information and relay UE information configured by the second network node for the remote UE.

[0695] The SL multi-path establishment device shown in Figures 15 and 16 in the embodiments of the present application can be a network side device, such as an access network device (such as gNB) or a CU.

[0696] The embodiments of the present application provide various processes implemented by the second network node in the method embodiments of Figures 4 to 13, and achieve the same technical effects. To avoid repetition, they are not described here.

[0697] As shown in Figure 17, an embodiment of the present application further provides a terminal 1700, including a processor 1701 and a memory 1702, wherein the memory 1702 stores a program or instruction that can be run on the processor 1701. For example, when the terminal 1700 is a terminal, the program or instruction, when executed by the processor 1701, implements the various steps of the above-mentioned SL multi-path establishment method embodiment and can achieve the same technical effect. When the terminal 1700 is a network-side device, the program or instruction, when executed by the processor 1701, implements the various steps of the above-mentioned SL multi-path establishment method embodiment and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0698] An embodiment of the present application also provides a terminal, including a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is configured to execute a program or instruction to implement the steps performed by the remote UE in the method embodiments shown in Figures 4 to 13. This terminal embodiment corresponds to the aforementioned method embodiment on the remote UE side, and each implementation process and implementation method of the aforementioned method embodiment can be applied to this terminal embodiment and achieve the same technical effects. Specifically, Figure 19 is a schematic diagram of the hardware structure of a terminal implementing an embodiment of the present application.

[0699] The terminal 1800 includes but is not limited to: a radio frequency unit 1801, a network module 1802, an audio output unit 1803, an input unit 1804, a sensor 1805, a display unit 1806, a user input unit 1807, an interface unit 1808, a memory 1809 and at least some of the components of the processor 1810.

[0700] Those skilled in the art will appreciate that the terminal 1800 may also include a power supply (such as a battery) to power various components. The power supply may be logically connected to the processor 1810 via a power management system, thereby enabling the power management system to manage charging, discharging, and power consumption. The terminal structure shown in FIG18 does not limit the terminal. The terminal may include more or fewer components than shown, or combine certain components, or have different component arrangements, which will not be described in detail here.

[0701] It should be understood that in an embodiment of the present application, the input unit 1804 may include a graphics processing unit (GPU) 18041 and a microphone 18042, and the graphics processor 18041 processes the image data of a static picture or video obtained by an image capture device (such as a camera) in a video capture mode or an image capture mode. The display unit 1806 may include a display panel 18061, and the display panel 18061 may be configured in the form of a liquid crystal display, an organic light emitting diode, etc. The user input unit 1807 includes a touch panel 18071 and at least one of other input devices 18072. The touch panel 18071 is also called a touch screen. The touch panel 18071 may include two parts: a touch detection device and a touch controller. Other input devices 18072 may include, but are not limited to, a physical keyboard, function keys (such as volume control keys, switch keys, etc.), a trackball, a mouse, and a joystick, which will not be repeated here.

[0702] In the embodiment of the present application, after receiving downlink data from a network-side device, the RF unit 1801 may transmit the data to the processor 1810 for processing. Furthermore, the RF unit 1801 may send uplink data to the network-side device. Typically, the RF unit 1801 includes, but is not limited to, an antenna, an amplifier, a transceiver, a coupler, a low-noise amplifier, a duplexer, and the like.

[0703] Memory 1809 can be used to store software programs or instructions and various data. Memory 1809 may primarily include a first storage area for storing programs or instructions and a second storage area for storing data. The first storage area may store an operating system, applications or instructions required for at least one function (such as a sound playback function, an image playback function, etc.). Furthermore, memory 1809 may include volatile memory or non-volatile memory. The non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. Volatile memory can be random access memory (RAM), static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct RAM bus random access memory (DRRAM). The memory 1809 in the embodiment of the present application includes but is not limited to these and any other suitable types of memory.

[0704] Processor 1810 may include one or more processing units. Optionally, processor 1810 integrates an application processor and a modem processor. The application processor primarily handles operations related to the operating system, user interface, and application programs, while the modem processor primarily processes wireless communication signals, such as a baseband processor. It is understood that the modem processor may not be integrated into processor 1810.

[0705] It can be understood that the implementation process of each implementation method mentioned in this embodiment can refer to the relevant description of the remote UE in the method embodiment, and achieve the same or corresponding technical effects. To avoid repetition, it will not be repeated here.

[0706] The present application also provides a network-side device, including a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is configured to execute a program or instruction to implement the steps of the first network node or the second network node in the method embodiments shown in Figures 4 to 13. This network-side device embodiment corresponds to the above-mentioned first network node or second network node method embodiment, and each implementation process and implementation method of the above-mentioned method embodiment can be applied to this network-side device embodiment and can achieve the same technical effects.

[0707] Specifically, an embodiment of the present application also provides a network-side device. As shown in Figure 19, the network-side device 1900 includes: an antenna 1901, a radio frequency device 1902, a baseband device 1903, a processor 1904, and a memory 1905. Antenna 1901 is connected to radio frequency device 1902. In the uplink direction, radio frequency device 1902 receives information via antenna 1901 and sends the received information to baseband device 1903 for processing. In the downlink direction, baseband device 1903 processes the information to be transmitted and sends it to radio frequency device 1902. Radio frequency device 1902 processes the received information and sends it through antenna 1901.

[0708] The method executed by the network-side device in the above embodiment may be implemented in the baseband device 1903 , which includes a baseband processor.

[0709] The baseband device 1903 may include, for example, at least one baseband board, on which multiple chips are arranged, as shown in Figure 190, one of which is, for example, a baseband processor, which is connected to the memory 1905 through a bus interface to call the program in the memory 1905 and execute the network device operations shown in the above method embodiment.

[0710] The network side device may further include a network interface 1906 , which is, for example, a Common Public Radio Interface (CPRI).

[0711] Specifically, the network side device 1900 of an embodiment of the present invention also includes: instructions or programs stored in the memory 1905 and executable on the processor 1904. The processor 1904 calls the instructions or programs in the memory 1905 to execute the methods executed by the modules shown in FIG15 or FIG16 and achieve the same technical effect. To avoid repetition, they will not be elaborated here.

[0712] An embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by the processor, the various processes of the above-mentioned SL multi-path establishment method embodiment are implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0713] The processor is the processor in the terminal described in the above embodiment. The readable storage medium includes a computer-readable storage medium, such as a computer read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk. In some examples, the readable storage medium may be a non-transitory readable storage medium.

[0714] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned SL multi-path establishment method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0715] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0716] An embodiment of the present application further provides a computer program / program product, which is stored in a storage medium. The computer program / program product is executed by at least one processor to implement the various processes of the above-mentioned SL multi-path establishment method embodiment and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0717] An embodiment of the present application also provides a SL multi-path establishment system, including: a terminal and a network side device, wherein the terminal can be used to execute the steps of the remote UE in the SL multi-path establishment method as described above, and the network side device can be used to execute the steps of the first network node or the second network node in the SL multi-path establishment method as described above.

[0718] It should be noted that, in this article, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the opposite order according to the functions involved. For example, the described method may be performed in an order different from that described, and various steps may also be added, omitted or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0719] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of a computer software product plus a necessary general-purpose hardware platform, or of course, by hardware. The computer software product is stored in a storage medium (such as ROM, RAM, magnetic disk, optical disk, etc.) and includes a number of instructions for enabling a terminal or network-side device to execute the methods described in each embodiment of the present application.

[0720] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms of implementation methods without departing from the purpose of this application and the scope of protection of the claims. These implementation methods are all within the protection of this application.

Claims

1. A side link SL multipath establishment method, the method comprising: The remote user equipment UE receives a first configuration sent by a first network node through a first communication link, where the first communication link is a communication link between the remote UE and the first network node, and the first configuration is used to establish a second communication link between the remote UE and a second network node; The remote UE establishes the second communication link based on the first configuration; The communication link is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link.

2. The method according to claim 1, wherein: Before the remote UE receives the first configuration sent by the first network node through the first communication link, the method further includes: The remote UE sends link information of the second communication link to the first network node through the first communication link.

3. The method according to claim 2, wherein: The remote UE sending link information of the second communication link to the first network node through the first communication link includes: When the link quality of the second communication link meets the link quality requirement, the remote UE sends link information of the second communication link to the first network node through the first communication link; The link quality requirement includes at least one of the following: The link measurement result of the communication link meets the first measurement trigger condition; There is an ideal backhaul condition between the relay UE and the remote UE in the communication link.

4. The method according to claim 3, wherein: Before the remote UE sends link information of the second communication link to the first network node through the first communication link, the method further includes: Receiving, by the remote UE, first information sent by the first network node through the first communication link; The first information includes at least one of the following: A link measurement configuration, wherein the link measurement configuration includes the first measurement triggering condition; The first indication information is used to instruct the remote UE to report information of the relay UE having an ideal backhaul condition with the remote UE.

5. The method according to claim 3 or 4, wherein: The first measurement triggering condition includes at least one of the following: The link quality between the remote UE and the relay UE is greater than or equal to the first threshold; A received signal quality RSRP from the remote UE to the cell in the second network node is greater than or equal to a second threshold.

6. The method according to any one of claims 1 to 5, wherein: The first network node and the second network node are different access network nodes; Alternatively, the first network node is a first centralized unit CU, and the second network node is a second CU; Alternatively, the first network node and the second network node are both third CUs.

7. The method according to claim 6, wherein: The first network node and the second network node are different access network nodes; or, the first network node is a first CU, and the second network node is a second CU; After the remote UE establishes the second communication link based on the first configuration, the method further includes any one of the following: The remote UE sends a first message to the first network node; The remote UE sends a second message or any data to the second network node through the second communication link; The remote UE initiates an access process to the second network node; The first message and the second message are used to notify the remote UE that the second Communication link; the second message includes any one of the following: an RRC message carried on the signaling radio bearer SRB of the second communication link, and an RRC reconfiguration completion message.

8. The method according to any one of claims 1 to 7, wherein: The link information of the second communication link includes at least one of the following: Relevant information of the relay UE in the first communication link; Serving cell information of the remote UE; The relevant information of the relay UE includes at least one of the following: identification information of the relay UE and serving cell information of the relay UE.

9. The method according to any one of claims 1 to 8, wherein: The first configuration includes at least one of the following: End-to-end E2E bearer configuration of the remote UE on the second network node; The transmission configuration of the remote UE at the PC5 interface; The transmission configuration of the remote UE at the Uu interface; The basic configuration of the remote UE includes at least one of the cell information and relay UE information configured by the second network node for the remote UE.

10. A SL multi-path establishment method, the method comprising: The first network node sends a first configuration to a remote UE through a first communication link, where the first communication link is a communication link between the remote UE and the first network node, and the first configuration is used to establish a second communication link between the remote UE and a second network node; The communication link is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link.

11. The method according to claim 10, wherein: The first network node and the second network node are different access network nodes; Alternatively, the first network node is a first CU, and the second network node is a second CU; Alternatively, the first network node and the second network node are both third CUs.

12. The method according to claim 10 or 11, wherein: The first configuration includes at least one of the following: End-to-end E2E bearer configuration of the remote UE on the second network node; The transmission configuration of the remote UE at the PC5 interface; The transmission configuration of the remote UE at the Uu interface; The basic configuration of the remote UE includes at least one of the cell information and relay UE information configured by the second network node for the remote UE.

13. The method according to any one of claims 10 to 12, wherein: Before the first network node sends the first configuration to the remote UE through the first communication link, the method further includes: The first network node receives link information of the second communication link sent by the remote UE through the first communication link.

14. The method according to claim 13, wherein: The link information of the second communication link includes at least one of the following: Relevant information of the relay UE in the first communication link; Serving cell information of the remote UE; The relevant information of the relay UE includes at least one of the following: identification information of the relay UE and serving cell information of the relay UE.

15. The method according to any one of claims 10 to 14, wherein: The first network node and the second network node are different access network nodes; or, the first network node is a first CU, and the second network node is a second CU; Before the first network node sends the first configuration to the remote UE via the first communication link, the method Also includes: The first network node sends a first request message to the second network node, where the first request message is used to request to add the second communication link; The first network node receives a first response message sent by the second network node, where the first response message is used to indicate that the second network node supports providing a transmission service for the remote UE, and the first response message includes the first configuration.

16. The method according to claim 15, wherein: The first request message includes at least one of the following: security related information of the remote UE; Communication information of the remote UE; PDU session information offloaded by the remote UE to the second network node; DRB identification information of a data radio bearer supported by the second network node; The cell group configuration of the remote UE; RB information of the offload bearer of the remote UE; Protection rate information of the remote UE; Primary cell information of the remote UE; Relevant information of the relay UE in the second communication link; The service information and capability information of the remote UE.

17. The method according to any one of claims 10 to 16, wherein: The first network node and the second network node are different access network nodes; or, the first network node is a first CU, and the second network node is a second CU; After the first network node sends the first configuration to the remote UE through the first communication link, the method further includes: The first network node receives a first message sent by the remote UE, where the first message is used to notify the remote UE that the second communication link has been successfully established; The first network node sends a third message to the second network node, where the third message is used to notify the remote UE that the second communication link has been successfully established.

18. The method according to any one of claims 10 to 17, wherein: Before the first network node sends the first configuration to the remote UE through the first communication link, the method further includes: The first network node sends first information to the remote UE through the first communication link; The first information includes at least one of the following: A link measurement configuration, wherein the link measurement configuration includes the first measurement triggering condition; The first indication information is used to instruct the remote UE to report information of the relay UE having an ideal backhaul condition with the remote UE.

19. A SL multi-path establishment method, wherein: The method comprises: The second network node sends a first configuration, where the first configuration is used to establish a second communication link between a remote UE and the second network node; the second communication link is different from the first communication link of the remote UE; the first communication link is a communication link between the remote UE and the first network node, and the first communication link is used by the first network node to send the first configuration to the remote UE; The communication link is a direct link or an indirect link of the remote UE.

20. The method according to claim 19, wherein: The first network node and the second network node are different access network nodes; Alternatively, the first network node is a first CU, and the second network node is a second CU; Alternatively, the first network node and the second network node are both third CUs.

21. The method according to claim 20, wherein: The first network node and the second network node are different access network nodes; or, the first network node is a first CU, and the second network node is a second CU; The second network node sending a first configuration includes: The second network node receives a first request message sent by the first network node, where the first request message is used to request to add the second communication link; The second network node sends a first response message to the first network node, where the first response message includes the first configuration.

22. The method according to claim 21, wherein: The first request message includes at least one of the following: security related information of the remote UE; Communication information of the remote UE; PDU session information offloaded by the remote UE to the second network node; DRB identification information of a data radio bearer supported by the second network node; The cell group configuration of the remote UE; RB information of the offload bearer of the remote UE; Protection rate information of the remote UE; Primary cell information of the remote UE; Relevant information of the relay UE in the second communication link; The service information and capability information of the remote UE.

23. The method according to claim 21, wherein: After the second network node receives the first request message sent by the first network node, the method further includes at least one of the following: The second network node accepts the first service and generates configurations of the remote UE and the first relay UE; The second network node sends an RRC reconfiguration message to the first relay UE, where the RRC reconfiguration message includes at least one of information about the first service and relevant information about the first relay UE; The second network node generates a configuration of the remote UE; The second network node accepts the first service and generates a configuration of the remote UE; The first service is a service that the remote UE needs to transmit through the second communication link, and the first relay UE is a relay UE in the second communication link.

24. The method according to claim 20, wherein: The first network node and the second network node are both third CUs; The second network node sending a first configuration includes: The second network node sends the first configuration to the remote UE through the first communication link.

25. The method according to claim 21 or 24, wherein: The method further comprises: The fourth CU sends a second request message to the first DU, where the fourth CU is the second CU or the third CU; the first DU is the DU corresponding to the second communication link, and the second request message is used to request the transmission configuration of the remote UE responsible for the first DU in the second communication link, and the second request message includes a second configuration, and the second configuration includes the E2E bearer configuration of the remote UE in the fourth CU; The fourth CU receives a second response message sent by the first DU, where the second response message includes a third configuration and an acceptance result of the first DU for the second configuration; The second communication link is a direct link of the remote UE, and the third configuration includes the transmission configuration on the Uu interface configured by the first DU for the remote UE; or, the second communication link is an indirect link of the remote UE, and the third configuration includes the transmission configuration on the PC5 interface configured by the first DU for the remote UE.

26. The method according to claim 21 or 24, wherein: The second communication link is an indirect link of the remote UE; The method further comprises: The fourth CU sends a third request message to the first DU, where the fourth CU is the second CU or the third CU; the first DU is the DU corresponding to the second communication link, and the third request message is used to request the transmission configuration of the relay UE responsible for the first DU in the second communication link, and the third request message includes a fourth configuration, and the fourth configuration includes the E2E bearer configuration of the remote UE in the fourth CU; The fourth CU receives a third response message sent by the first DU, where the third response message includes the fifth configuration and an acceptance result of the first DU for the fourth configuration; The fifth configuration includes the transmission configuration on the PC5 interface and the Uu interface configured by the first DU for the relay UE.

27. The method according to any one of claims 19 to 26, wherein: The first configuration includes at least one of the following: End-to-end E2E bearer configuration of the remote UE on the second network node; The transmission configuration of the remote UE at the PC5 interface; The transmission configuration of the remote UE at the Uu interface; The basic configuration of the remote UE includes at least one of the cell information and relay UE information configured by the second network node for the remote UE.

28. A SL multi-path establishment device, wherein: The device comprises: a receiving module and an establishing module; The receiving module is configured to receive a first configuration sent by a first network node through a first communication link, where the first communication link is a communication link between the remote UE and the first network node, and the first configuration is used to establish a second communication link between the remote UE and a second network node; The establishing module is used to establish the second communication link based on the first configuration received by the receiving module; The communication link is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link.

29. A SL multi-path establishment device, wherein: The device comprises: a sending module; The sending module is used to send a first configuration to a remote UE through a first communication link, where the first communication link is a communication link between the remote UE and a first network node, and the first configuration is used to establish a second communication link between the remote UE and a second network node; The communication link is a direct link or an indirect link of the remote UE, and the first communication link is different from the second communication link.

30. A SL multi-path establishment device, wherein: The device comprises: a sending module; The sending module is used to send a first configuration, where the first configuration is used to establish a second communication link between a remote UE and a second network node; the second communication link is different from the first communication link of the remote UE; the first communication link is a communication link between the remote UE and the first network node, and the first communication link is used by the first network node to send the first configuration to the remote UE; The communication link is a direct link or an indirect link of the remote UE.

31. A terminal, wherein: It includes a processor and a memory, the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the steps of the SL multi-path establishment method as described in any one of claims 1 to 9 are implemented.

32. A network side device, wherein: It includes a processor and a memory, the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the steps of the SL multi-path establishment method as described in any one of claims 10 to 27 are implemented.

33. A readable storage medium, wherein: The readable storage medium stores programs or instructions, and when the programs or instructions are executed by the processor, they implement the SL multipath establishment method as described in any one of claims 1 to 9, or implement the SL multipath establishment method as described in any one of claims 10 to 18, or implement the steps of the SL multipath establishment method as described in any one of claims 19 to 27.

34. A chip, wherein: The chip includes a processor and a communication interface, the communication interface is coupled to the processor, and the processor is used to run a program or instruction to implement the SL multi-path establishment method as described in any one of claims 1 to 9, or to implement the SL multi-path establishment method as described in any one of claims 10 to 18, or to implement the SL multi-path establishment method as described in any one of claims 19 to 27.

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