Communication method, apparatus and system

Abstract

The present application relates to the technical field of communications. Disclosed are a communication method, apparatus and system. The method comprises: a first node receiving a first message from a third node, wherein the first message is used for requesting the addition of the first node as a secondary node of second multi-connectivity of a terminal, the multi-connectivity that currently serves the terminal is first multi-connectivity, a master node of the first multi-connectivity is a second node, and a secondary node of the first multi-connectivity is the first node; and in response to the first message, sending a second message to the third node, wherein the second message is used for accepting the addition of the first node as the secondary node of the second multi-connectivity, the second multi-connectivity is a candidate multi-connectivity that serves the terminal, a master node of the second multi-connectivity is the third node, and the third node is a candidate master node to which the terminal switches. By means of the method, a secondary-node addition process can be executed in advance in a configuration stage, thereby facilitating the rapid resumption of data transmission of a secondary node, and reducing the time delay of the secondary node resuming data transmission, and thus avoiding service interruption.

Description

Communication method, device and system

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of the People's Republic of China on March 21, 2024, with application number 202410335430.2 and application name "A Communication Method, Device and System", the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of communication technology, and in particular to a communication method, device, and system. Background Art

[0004] In wireless communication systems, a terminal may be connected to multiple network nodes simultaneously. This means that the resources of multiple network nodes provide communication services to the terminal, enabling high-speed transmission. When a terminal is connected to multiple network nodes simultaneously, this is called multi-connectivity. The network node that interacts with the core network for control plane signaling is called the master node (MN), and the other network nodes are called secondary nodes (SN).

[0005] However, in the cell handover scenario, how to quickly restore data transmission of the secondary node still needs further research. Summary of the Invention

[0006] The present application provides a communication method, device, and system for quickly recovering data transmission of a secondary node.

[0007] In the first aspect, an embodiment of the present application provides a communication method, which can be applied to a first node, and the first node can be a first network device or a component in the first network device (such as a chip or circuit). For example, in the method provided in the first aspect, the first node receives a first message from a third node, and the first message is used to request that the first node be added as a secondary node of the second multi-connection of the terminal, the multi-connection currently serving the terminal is the first multi-connection, the main node of the first multi-connection is the second node, and the secondary node of the first multi-connection is the first node; in response to the first message, a second message is sent to the third node, and the second message is used to accept the addition of the first node as a secondary node of the second multi-connection, the second multi-connection is a candidate multi-connection serving the terminal, the main node of the second multi-connection is the third node, and the third node is a candidate primary node for the terminal to switch.

[0008] Using the above method, when the multi-connection currently serving the terminal is the first multi-connection, the third node (i.e., the candidate master node) adds the first node as the auxiliary node of the second multi-connection, that is, the auxiliary node addition process can be executed in advance during the configuration stage, so that when the main node of the terminal switches (for example, the main node of the terminal switches to the third node), the third node no longer needs to execute the auxiliary node addition process, which facilitates the rapid recovery of data transmission of the auxiliary node, reduces the delay of the auxiliary node in resuming data transmission, and avoids business interruption.

[0009] In one possible design, the method further includes: receiving a third message, where the third message is used to instruct the main node of the terminal to switch to the third node; and in response to the third message, determining to use the second multi-connection service to serve the terminal.

[0010] In this way, the first node learns from the third message that the primary node of the terminal is switched to the third node, thereby determining to use the second multi-connection service terminal, so as to quickly resume data transmission of the secondary node.

[0011] In one possible design, the second message includes first information, where the first information is used by the terminal to monitor the control channel of the first node after the terminal determines to use the second multi-connection service to serve the terminal.

[0012] In this way, since the first information is sent to the terminal during the configuration stage, the terminal can monitor the control channel of the first node according to the first information after determining to use the second multi-connection service terminal, without waiting for the instruction to monitor the control channel of the first node, thereby facilitating the rapid recovery of data transmission of the auxiliary node.

[0013] In one possible design, the third message is also used to request activation of the second multi-connected secondary cell group (for example, the third message includes an activation request, and the activation request is used to request activation of the second multi-connected secondary cell group), and the first node manages the secondary cell group; the method also includes: activating the second multi-connected secondary cell group in response to the third message; or, the third message is also used to request deactivation of the second multi-connected secondary cell group (for example, the third message includes a deactivation request, and the deactivation request is used to request activation of the second multi-connected secondary cell group); the method also includes: deactivating the second multi-connected secondary cell group in response to the third message.

[0014] In this way, when the main node of the terminal switches to the third node, the third node decides to activate or deactivate the second multi-connected secondary cell group. For example, the third node can activate or deactivate the second multi-connected secondary cell group according to actual needs, making the implementation more flexible.

[0015] In one possible design, the method also includes: receiving security information from the second node or the third node, the security information including N key information, the N key information being associated with the second multi-connection; N is an integer greater than or equal to 1; after determining that the second multi-connection is a service multi-connection for the terminal, the method also includes: using first key information to communicate with the terminal, the first key information being unused key information among the N key information.

[0016] In this way, the security information is sent to the first node through the second node or the third node, so that the first node can perform secure communication with the terminal after determining that the second multi-connection is the serving multi-connection of the terminal.

[0017] In one possible design, the security information is carried in the first message.

[0018] In one possible design, the security information also includes N count values, and the N key information is associated one-to-one with the N count values; the method also includes: sending the N count values ​​encapsulated in the auxiliary node format to the terminal through the third node.

[0019] In this way, by sending N count values ​​to the terminal, the terminal can perform secure communication with the first node after determining that the second multi-connection is the serving multi-connection of the terminal.

[0020] In one possible design, the third message also includes second key information; after determining that the second multi-connection is the service multi-connection of the terminal, the method also includes: using the second key information to communicate with the terminal.

[0021] In this way, when the main node of the terminal is switched to the third node, the source node of the switch can send the second key information to the target node of the switch (i.e., the third node), and then the third node sends the second key information to the first node through a third message, so that the first node can securely communicate with the terminal based on the second key information. In addition, the source node of the switch can send a second count value to the terminal through a switch command message, so that the terminal can securely communicate with the first node based on the second count value, and the second count value is associated with the second key information.

[0022] In one possible design, the first message includes first identification information, the first identification information is associated with a first configuration, and the first configuration is used for the first multi-connected secondary cell group; the method also includes: determining that the first configuration is also used for the second multi-connected secondary cell group; wherein the first node manages the first multi-connected secondary cell group and the second multi-connected secondary cell group.

[0023] In one possible design, the method also includes: sending a fourth message to the second node, the fourth message including at least one of the following: first identification information, the first identification information is associated with a first configuration, the first configuration is used for the first multi-connected secondary cell group; identification information of a used RB, the used RB terminates at the first node; and QoS flow information mapped to the used RB.

[0024] In this way, after the first node sends the first identification information to the second node, the second node can send the first identification information to different candidate master nodes, and then regardless of whether the candidate master node is configured with multiple connections, it can communicate with the first node based on the first identification information. After the first node sends the identification information of the used RB and the QoS flow information mapped to the used RB to the second node, the second node can send the identification information of the used RB and the QoS flow information mapped to the used RB to different candidate master nodes, and then, if the candidate master node is not configured with multiple connections, the candidate master node can replace the node where the used RB terminates with itself.

[0025] In one possible design, the method also includes: receiving a fifth message from a fourth node, the fifth message being used to request that the first node be added as a third multi-connected secondary node of the terminal, the third multi-connected primary node being the fourth node, and the fourth node being a candidate primary node for the terminal to switch; in response to the fifth message, sending a sixth message to the fourth node, the sixth message being used to refuse to add the first node as a third multi-connected secondary node.

[0026] For another example, in the method provided in the first aspect, the first node receives a fifth message from the fourth node, and the fifth message is used to request that the first node be added as a secondary node of the third multi-connection of the terminal, the multi-connection currently serving the terminal is the first multi-connection, the main node of the first multi-connection is the second node, and the secondary node of the first multi-connection is the first node; in response to the fifth message, a sixth message is sent to the fourth node, and the sixth message is used to indicate a refusal to add the first node as a secondary node of the third multi-connection, the third multi-connection is a candidate multi-connection serving the terminal, the main node of the third multi-connection is the fourth node, and the fourth node is a candidate primary node for the terminal to switch.

[0027] In the second aspect, an embodiment of the present application provides a communication method, which can be applied to a third node, and the third node can be a third network device or a component in the third network device (such as a chip or circuit). For example, in the method provided in the second aspect, the third node sends a first message to the first node, and the first message is used to request that the first node be added as a secondary node of the second multi-connection of the terminal, the multi-connection currently serving the terminal is the first multi-connection, the main node of the first multi-connection is the second node, and the secondary node of the first multi-connection is the first node; a second message is received from the first node, and the second message is used to accept the addition of the first node as a secondary node of the second multi-connection, the second multi-connection is a candidate multi-connection serving the terminal, the main node of the second multi-connection is the third node, and the third node is a candidate primary node for the terminal to switch.

[0028] In one possible design, the method further includes: sending a third message to the first node, where the third message is used to instruct the main node of the terminal to switch to the third node.

[0029] In one possible design, the third message is also used to request activation of the second multi-connected secondary cell group or deactivation of the second multi-connected secondary cell group, and the first node manages the secondary cell group.

[0030] In one possible design, the method further includes: sending security information, the security information including N key information, the N key information being associated with the second multi-connection; N is an integer greater than or equal to 1.

[0031] In one possible design, the security information also includes N count values, and the N key information and the N count values ​​are associated one-to-one; the method also includes: receiving the N count values ​​encapsulated in the auxiliary node format from the first node; and sending the N count values ​​encapsulated in the auxiliary node format to the terminal through the second node.

[0032] In one possible design, the method also includes: receiving first identification information from the second node, the first identification information is associated with a first configuration, and the first configuration is used for the first multi-connected secondary cell group; wherein the first message includes the first identification information.

[0033] In one possible design, the method also includes: receiving sequence number status information of a used RB, wherein the used RB terminates at the first node; sending the sequence number status information to the first node, wherein the sequence number status information is used to determine a receiving window of a packet data convergence layer protocol PDCP.

[0034] In the third aspect, an embodiment of the present application provides a communication method, which can be applied to a fourth node, and the fourth node can be a fourth network device or a component in the fourth network device (such as a chip or circuit). For example, in the method provided in the third aspect, the fourth node sends a fifth message to the first node, and the fifth message is used to request that the first node be added as a secondary node of the third multi-connection of the terminal, the multi-connection currently serving the terminal is the first multi-connection, the main node of the first multi-connection is the second node, and the secondary node of the first multi-connection is the first node; receive a sixth message from the first node, and the sixth message is used to refuse to add the first node as a secondary node of the third multi-connection, the third multi-connection is a candidate multi-connection serving the terminal, the main node of the third multi-connection is the fourth node, and the fourth node is a candidate primary node for the terminal to switch.

[0035] In one possible design, the method further includes: receiving identification information of a used RB, where the used RB terminates at the first node; and determining that the node where the used RB terminates is replaced with the fourth node.

[0036] In one possible design, the method also includes: sending a switching command message to the terminal, wherein the switching command message is used to instruct the main node of the terminal to switch to a third node; and sending the serial number status information of the used RB to the third node, wherein the serial number status information is used to determine the receiving window of the packet data convergence layer protocol PDCP.

[0037] In one possible design, the switching command message is also used to indicate a second count value; the method also includes: sending second key information, the second key information is used for communication between the first node and the terminal, and the second key information is associated with the second count value.

[0038] In a fourth aspect, an embodiment of the present application provides a communication method, which can be applied to a second node, and the second node can be a second network device or a component in the second network device (such as a chip or circuit). For example, in the method provided in the fourth aspect, the second node receives a fourth message from the first node, and the fourth message includes first identification information, and the first identification information is associated with a first configuration, and the first configuration is used for a first multi-connected secondary cell group of the terminal; the multi-connection currently serving the terminal is the first multi-connection, the master node of the first multi-connection is the second node, and the auxiliary node of the first multi-connection is the first node; the first identification information is sent to a third node, and the third node is a candidate master node for switching.

[0039] In this way, after the first node sends the first identification information to the second node, the second node can send the first identification information to the candidate master node, and then regardless of whether the candidate master node is configured with multiple connections, it can communicate with the first node based on the first identification information.

[0040] In one possible design, the fourth message also includes identification information of the used RB and / or QoS flow information mapped to the used RB, and the used RB terminates at the first node; the second node is the primary node of the first multi-connection of the terminal, the first node is the secondary node of the first multi-connection, and the first multi-connection is the service multi-connection of the terminal; the identification information of the used RB and / or the QoS flow information mapped to the used RB is sent to the third node.

[0041] In this way, after the first node sends the identification information of the used RB and the QoS flow information mapped to the used RB to the second node, the second node can send the identification information of the used RB and the QoS flow information mapped to the used RB to the candidate master node, and then, if the candidate master node is not configured with multiple connections, the candidate master node can replace the node where the used RB terminates with itself.

[0042] In one possible design, the method also includes: sending security information, the security information including N key information, the N key information being associated with at least one candidate multi-connection of the terminal, and N being an integer greater than or equal to 1; wherein the at least one candidate multi-connection includes a second multi-connection, the main node of the second multi-connection is the third node, and the secondary node of the second multi-connection is the first node.

[0043] In one possible design, the security information also includes N count values, and the N key information is associated one-to-one with the N count values; the method also includes: receiving the N count values ​​encapsulated in the auxiliary node format; and sending the N count values ​​encapsulated in the auxiliary node format to the terminal.

[0044] In a fifth aspect, an embodiment of the present application provides a communication method, which can be applied to a terminal-side device, and the terminal-side device can be a terminal or a component in the terminal (such as a chip or circuit). For example, in the method provided in the fifth aspect, the terminal-side device receives N count values ​​encapsulated in a secondary node format, and the N count values ​​are associated with a second multi-connection, the master node of the second multi-connection is the third node, the secondary node of the second multi-connection is the first node, and the third node is a candidate master node for switching; after the master node of the terminal-side device is switched to the third node, the first count value is used to communicate with the first node, and the first count value is an unused count value among the N count values.

[0045] For another example, in the method provided in the fifth aspect, the terminal side device receives a switching command message, wherein the switching command message is used to instruct the main node of the terminal to switch to a third node, the third node is the second multi-connected main node of the terminal, and the second multi-connected auxiliary node is the first node; the switching command message includes a second count value; after the main node of the terminal side device is switched to the third node, the second count value is used to communicate with the first node.

[0046] In one possible design, the method further includes: receiving a switching command message, wherein the switching command message is used to instruct the main node of the terminal side device to switch to the third node; and in response to the switching command message, determining to use the second multi-connection service to serve the terminal side device.

[0047] In one possible design, the method also includes: receiving first information, the first information being used to monitor the control channel of the first node after determining to use the second multi-connection service for the terminal side device; and based on the first information, monitoring the control channel of the first node after determining to use the second multi-connection service for the terminal side device.

[0048] In one possible design, the method further includes: receiving a second configuration, where the second configuration is used for the second multi-connected secondary cell group, and the first information is included in the second configuration.

[0049] In a sixth aspect, the present application provides a communication device, which has the ability to implement the functions involved in any one of the first to fifth aspects above. For example, the communication device includes modules or units or means corresponding to the operations involved in any one of the first to fifth aspects above. The functions or units or means can be implemented through software, or through hardware, or the corresponding software can be implemented through hardware.

[0050] In one possible design, the communication device includes a processing unit and a communication unit. The communication unit can be used to send and receive signals to enable communication between the communication device and other devices; the processing unit can be used to perform certain internal operations of the communication device. The functions performed by the processing unit and the communication unit can correspond to the operations described in any of the first to fifth aspects above.

[0051] In one possible design, the communication device includes a processor, which can be coupled to a memory. The memory can store the necessary computer programs or instructions for implementing the functions of any of the first to fifth aspects. The processor can execute the computer programs or instructions stored in the memory. When the computer programs or instructions are executed, the communication device implements the method of any possible design or implementation of the first to fifth aspects.

[0052] In one possible design, the communication device includes a processor and a memory, and the memory may store the necessary computer programs or instructions for implementing the functions of any of the first to fifth aspects described above. The processor may execute the computer program or instructions stored in the memory. When the computer program or instructions are executed, the communication device implements the method of any possible design or implementation of the first to fifth aspects described above.

[0053] In one possible design, the communication device includes a processor and an interface circuit, wherein the processor is used to communicate with other devices through the interface circuit and execute the method in any possible design or implementation of the first to fifth aspects above.

[0054] It can be understood that in the sixth aspect above, the processor can be implemented by hardware or by software. When implemented by hardware, the processor can be a logic circuit, an integrated circuit, etc.; when implemented by software, the processor can be a general-purpose processor, which is implemented by reading the software code stored in the memory. In addition, the above processors can be one or more, and the memories can be one or more. The memory can be integrated with the processor, or the memory and the processor can be set separately. In the specific implementation process, the memory can be integrated with the processor on the same chip, or can be set on different chips respectively. The embodiment of the present application does not limit the type of memory and the setting method of the memory and the processor.

[0055] In a seventh aspect, the present application provides a communication system, which may include a first node and a third node, the first node being used to execute the method described in the first aspect, and the third node being used to execute the method described in the second aspect.

[0056] Optionally, the communication system further includes a second node, and the second node is used to execute the method described in the fourth aspect above.

[0057] Optionally, the communication system further includes a fourth node, and the fourth node is used to execute the method described in the third aspect above.

[0058] Optionally, the communication system further includes a terminal side device, and the terminal side device is used to execute the method described in the fifth aspect above.

[0059] In an eighth aspect, the present application provides a computer-readable storage medium, in which computer-readable instructions are stored. When a computer reads and executes the computer-readable instructions, the computer executes the method in any possible design of the first to fifth aspects above.

[0060] Exemplarily, a computer-readable storage medium can be any available medium that can be accessed by a computer. By way of example and not limitation, a computer-readable medium can include a non-transitory computer-readable medium, a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a CD-ROM or other optical disk storage, a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer.

[0061] In a ninth aspect, the present application provides a computer program product, which, when read and executed by a computer, enables the computer to execute the method in any possible design of the first to fifth aspects above.

[0062] In the tenth aspect, the present application provides a chip (or chip system), which includes a processor, and the processor is coupled to a memory, and is used to read and execute a software program stored in the memory to implement the method in any possible design of the first to fifth aspects above. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] FIG1 is a schematic diagram of a communication system applicable to an embodiment of the present application;

[0064] FIG2 is a schematic diagram of a CU-DU separation architecture provided in an embodiment of the present application;

[0065] FIG3 is a flow chart of the communication method according to the first embodiment of the present application;

[0066] FIG4 is a possible exemplary block diagram of a device involved in an embodiment of the present application;

[0067] FIG5 is a schematic structural diagram of a network-side device provided in an embodiment of the present application;

[0068] FIG6 is a schematic structural diagram of a terminal-side device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0069] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings in the embodiments of the present application. The technical solutions in the embodiments of the present application can be applied to various communication systems, such as universal mobile telecommunications system (UMTS), wireless local area network (WLAN), wireless fidelity (Wi-Fi) system, 4th generation (4G) mobile communication system, such as long term evolution (LTE) system, fifth generation (5G) mobile communication system, such as new radio (NR) system, and future evolved communication systems, such as sixth generation (6G) mobile communication system.

[0070] This application will present various aspects, embodiments or features around a system that may include multiple devices, components, modules, etc. It should be understood and appreciated that each system may include additional devices, components, modules, etc., and / or may not include all the devices, components, modules, etc. discussed in conjunction with the accompanying drawings. In addition, combinations of these schemes may also be used. In addition, in the embodiments of this application, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described in this application as an "example" should not be interpreted as being more preferred or more advantageous than other embodiments or design schemes. Specifically, the use of the word "example" is intended to present concepts in a concrete way. In the embodiments of this application, "of", "corresponding, relevant" and "corresponding" can sometimes be used interchangeably. It should be noted that when the distinction is not emphasized, the meanings to be expressed are consistent.

[0071] The communication system and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. A person skilled in the art will appreciate that, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0072] To facilitate understanding of the embodiments of the present application, the communication system applicable to the embodiments of the present application is first described in detail using the communication system shown in Figure 1 as an example. As shown in Figure 1, the communication system 10 includes one or more network nodes 20, and one or more terminals 30, and optionally, one or more core network elements in the core network (not shown in the figure). Among them, the interface between the network node and the terminal can be a Uu interface (or air interface), and data can be transmitted between the network node 20 and the terminal 30 through air interface resources. For example, the terminal can be located within the communication coverage of one or more cells managed by the network node, and the cell providing services to the terminal (i.e., the service cell of the terminal) can be one or more.

[0073] (1) Terminal

[0074] A terminal can be a device that accesses the above-mentioned communication system and has wireless transceiver capabilities. A terminal may also be called user equipment (UE), terminal equipment, user device, access terminal, user unit, user station, mobile station, mobile station (MS), remote station, remote terminal, mobile device, user terminal, terminal unit, terminal station, terminal device, wireless communication device, user agent, or user device.

[0075] For example, the terminal in the embodiment of the present application can be a mobile phone, a personal digital assistant (PDA), a laptop computer, a tablet computer, a drone, a computer with wireless transceiver function, a machine type communication (MTC) terminal, a virtual reality (VR) terminal, an augmented reality (AR) terminal, an Internet of Things (IoT) terminal, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home (such as a game console, a smart TV, a smart speaker, a smart refrigerator, and fitness equipment, etc.), a vehicle-mounted terminal, and a roadside unit (RSU) with terminal function.

[0076] (2) Network nodes

[0077] A network node is a network device (such as an access network device or a wireless access network device) located on the network side of the above-mentioned communication system and having wireless transceiver functions, or it can also be a component (such as a chip or circuit) in a network device. In the embodiments of this application, "a network node is a network device" is used as an example for description.

[0078] For example, the network node in the embodiment of the present application can be an access point (AP) in a Wi-Fi system, such as a home gateway, a router, a server, a switch, a bridge, etc., a base station, an evolved Node B (eNB), a radio network controller (RNC), a base station controller (BSC), a base transceiver station (BTS), a home base station, a baseband unit (BBU), a wireless relay node, a wireless backhaul node, etc. It can also be a next-generation NodeB (gNB) in a 5G system, or a network node constituting a gNB, such as an RSU with base station functions, or it can also be a satellite or various future forms of base stations.

[0079] (3) Wireless bearer

[0080] Communication between terminals and network nodes follows a certain protocol layer structure. For example, the control plane protocol layer structure may include the radio resource control (RRC) layer, the packet data convergence protocol (PDCP) layer, the radio link control (RLC) layer, the media access control (MAC) layer, and the physical layer (PHY). The user plane protocol layer structure may include the PDCP layer, the RLC layer, the MAC layer, and the physical layer. In one possible implementation, the service data adaptation protocol (SDAP) layer may also be included above the PDCP layer. The SDAP layer, PDCP layer, RLC layer, MAC layer, and physical layer may also be collectively referred to as the access layer. For a detailed description of each of the above protocol layers, please refer to the relevant technical specifications of the 3rd Generation Partnership Project (3GPP).

[0081] When a terminal and a network node perform user-plane data transmission, the data needs to pass through the user-plane protocol layers, such as the SDAP layer, PDCP layer, RLC layer, MAC layer, and physical layer. For example, data is transmitted between the terminal and the network node by establishing at least one data radio bearer (DRB). Each DRB may correspond to a set of functional entities, such as a PDCP layer entity, at least one RLC layer entity corresponding to the PDCP layer entity, at least one MAC layer entity corresponding to the at least one RLC layer entity, and at least one physical layer entity corresponding to the at least one MAC layer entity.

[0082] When a terminal and a network node perform control plane signaling, the signaling needs to pass through the control plane protocol layer, such as the RRC layer, PDCP layer, RLC layer, MAC layer, and physical layer. For example, the terminal and the network node establish at least one signaling radio bearer (SRB) to transmit signaling. Each SRB can correspond to a set of functional entities. For details, refer to the description of DRB. SRBs and DRBs can be collectively referred to as radio bearers (RBs).

[0083] (4) CU-DU separation architecture

[0084] For example, in some possible network structures, a network node may include one or more centralized units (CUs) and one or more distributed units (DUs), and multiple DUs may be centrally controlled by one CU. This architecture may be referred to as a CU-DU separation architecture. As an example, the interface between the CU and the DU may be referred to as an F1 interface, where the control plane (CP) interface may be an F1-C interface and the user plane (UP) interface may be an F1-U interface.

[0085] The processing functions of CU and DU can be divided according to the protocol layers of the wireless network: for example, as shown in Figure 2, the functions of the PDCP layer and above protocol layers are set in the CU, and the functions of the protocol layers below the PDCP layer (such as the RLC layer and the MAC layer, etc.) are set in the DU. It can be understood that the above division of the processing functions of CU and DU according to the protocol layer is only an example, and can also be divided in other ways, such as the functions of the protocol layers above the RLC layer are set in the CU, and the functions of the protocol layers below the RLC layer are set in the DU. For example, the CU or DU can be divided into functions with more protocol layers, and the CU or DU can also be divided into partial processing functions with protocol layers. The embodiments of the present application are not limited to this.

[0086] It can be understood that the embodiments of the present application do not limit the number of network nodes and terminals included in the communication system, and the above-mentioned communication system may also include other devices or network elements in addition to network nodes and terminals, such as core network network elements, relay equipment, etc., which are not limited by the embodiments of the present application.

[0087] The following first explains the relevant terms involved in the embodiments of this application. When not specifically explained, these explanations are intended to support the meaning of the relevant terms and make the embodiments of this application easier to understand, and should not be regarded as strict limitations on the relevant terms in the scope of protection claimed by this application.

[0088] (1) Cell switching

[0089] Cell switching (switch or handover) can be divided into two types, one of which is cell switching based on layer 1 / layer 2, which can be called layer 1 / layer 2 switching or layer 1 / layer 2 triggered mobility (L1 / L2 triggered mobility, LTM) switching, and the other is cell switching based on layer 3, which can be called layer 3 switching (L3 handover) or ordinary switching. Among them, layer 1 can refer to the physical layer, layer 2 can refer to any layer or multiple layers of the PDCP layer, RLC layer, and MAC layer, and layer 3 can refer to the RRC layer. Since layer 1 / layer 2 is located at a lower level of the protocol stack than the RRC layer (layer 3), layer 1 / layer 2 switching can also be called low-layer switching, or bottom layer switching, or lower layer switching. This application does not limit the name of the specific switching technology. In the embodiment of this application, LTM switching will be described as an example.

[0090] (2) Cell switching scenarios

[0091] When a terminal switches between different cells, there may be multiple specific switching scenarios, such as scenario 1 and scenario 2.

[0092] Scenario 1: A terminal switches from a cell managed by network node 1 to a cell managed by network node 2. In this scenario, network node 1 is called the source network node, and network node 2 is called the target network node. In other words, the source and target cells of the terminal belong to different network nodes. The cell handover associated with Scenario 1 is called an inter-gNB handover.

[0093] For example, when a CU-DU separation architecture is adopted (for example, a network node includes one CU and multiple DUs, the multiple DUs are centrally controlled by one CU, and each of the multiple DUs can manage one or more cells), network node 1 includes CU1 and DU1, CU1 controls DU1, network node 2 includes CU2 and DU2, CU2 controls DU2, and the above scenario 1 can also be described as: the terminal switches from a cell managed by DU1 to a cell managed by DU2, that is, the source cell and target cell of the terminal belong to different CUs. Therefore, cross-site switching can also be understood as inter-CU switching.

[0094] Scenario 2: A terminal switches from one cell managed by a network node to another cell managed by the same network node. In other words, the source and target cells belong to the same network node. The cell handover associated with Scenario 2 is known as an intra-gNB handover.

[0095] Exemplarily, when a CU-DU separation architecture is adopted (for example, the network node includes a CU, a DU1 controlled by the CU, and a DU2 controlled by the CU), the above scenario 2 can also be referred to as intra-CU switching. For example, intra-CU switching includes intra-DU switching and inter-DU switching. Intra-DU switching means that the terminal switches from a cell managed by a DU (such as DU1 or DU2) to another cell managed by the DU, that is, the source cell and the target cell of the terminal belong to the same DU; inter-DU switching means that the terminal switches from a cell of DU1 to a cell managed by DU2, that is, the source cell and the target cell of the terminal belong to different DUs controlled by the same CU.

[0096] (3) Multiple connections

[0097] In the communication system shown in Figure 1, when the terminal is connected to multiple network nodes at the same time, it can be called multi-connectivity, wherein when the terminal is connected to two network nodes at the same time, it can be called dual-connectivity (DC); that is, multi-connectivity can refer to dual connectivity, or it can also refer to the terminal being connected to more than two network nodes at the same time. Among them, one of the multiple network nodes (the network node that has control plane signaling interaction with the core network) is called the master node, and the other network nodes are called secondary nodes. The cell group managed by the master node that provides services to the terminal is called the master cell group (MCG), and the cell group managed by the secondary node that provides services to the terminal is called the secondary cell group (SCG). In addition, the multiple network nodes here can be base stations belonging to the same radio access technology (RAT) (for example, all 4G base stations, or all 5G base stations), or they can be base stations of different RATs (for example, one is a 4G base station and the other is a 5G base station). In the embodiment of the present application, multiple network nodes are 5G base stations (i.e., NR-DC) as an example for description.

[0098] In a multi-connection scenario, a bearer whose PDCP terminates on a primary node can be referred to as an MN-terminated bearer (MN-terminated RB), that is, downlink data directly reaches the primary node from the core network, is processed by the primary node's PDCP (for example, it may first pass through SDAP and then through PDCP processing), and then is sent to the terminal via RLC / MAC. Uplink data is processed by the primary node's PDCP (for example, it may first pass through PDCP and then through SDAP processing) and then is sent to the core network. Similarly, a bearer whose PDCP terminates on a secondary node can be referred to as an SN-terminated RB, that is, downlink data directly reaches the secondary node from the core network, is processed by the secondary node's PDCP (for example, it may first pass through SDAP and then through PDCP processing), and then is sent to the terminal via RLC / MAC. Uplink data is processed by the secondary node's PDCP (for example, it may first pass through PDCP and then through SDAP processing) and then is sent to the core network.

[0099] It can be understood that the multi-connection (such as dual connection) in the embodiment of the present application is described by taking the example of the terminal being connected to two network nodes, one network node being the main node and the other network node being the auxiliary node. When the terminal is connected to a single network node, the node can also serve as both the main node and the auxiliary node, and configure the main cell group and the auxiliary cell group at the same time.

[0100] Taking a dual-connection scenario as an example, after a terminal establishes a connection with a network node (i.e., a primary node), the primary node can add a secondary node to the terminal through the secondary node addition process, thereby establishing a dual connection. The primary and secondary nodes then communicate with the terminal via the dual connection. Furthermore, if the terminal's primary node switches, one possible implementation is: the terminal's source primary node sends a secondary node release request to the secondary node to notify the secondary node to stop transmitting data to the terminal; after the terminal successfully switches to the target primary node, the terminal first communicates with the target primary node. Subsequently, the target primary node adds a secondary node to the terminal through the secondary node addition process and establishes a new dual connection. The target primary node and secondary node then communicate with the terminal via the new dual connection.

[0101] However, using the above method, when the main node of the terminal switches, the target main node needs to execute the auxiliary node addition process to add an auxiliary node for the terminal before restoring the data transmission of the auxiliary node, which results in a large delay in the auxiliary node resuming data transmission and may cause business interruption.

[0102] Based on this, the embodiments of the present application will study the relevant implementations of cross-site switching scenarios (or cross-CU switching scenarios). Exemplarily, the embodiments of the present application provide a communication method for quickly restoring data transmission of a secondary node to avoid service interruption. Among them, the communication method provided in the embodiments of the present application involves a terminal side device and at least one network node (such as a first node, a second node, a third node, and a fourth node). The "terminal side device" can be a terminal, or it can also be a component in the terminal, such as a chip or chip system provided in the terminal. In the embodiments of the present application, the "terminal side device is a terminal" will be described as an example; the "network node" can be a network device, or it can also be a component in a network device, such as a chip or chip system provided in the network device.

[0103] The communication method provided in the embodiments of the present application is described in detail below in conjunction with specific embodiments.

[0104] FIG3 is a flow chart of the communication method according to an embodiment of the present application. As shown in FIG3 , the flow may include:

[0105] S301 , establishing a first multi-connection for serving a terminal, where a primary node of the first multi-connection is the second node and a secondary node of the first multi-connection is the first node.

[0106] After completing the establishment of the first multiple connections, the second node and the first node use the first multiple connection service terminal.

[0107] Exemplarily, after the terminal establishes a single connection with the second node, the second node can complete the establishment of the first multi-connection through the secondary node addition process. The establishment of the first multi-connection specifically includes: the second node sending a secondary node addition request (SN addition request) message to the first node, where the secondary node addition request message is used to request that the first node be added as a secondary node for the terminal's first multi-connection. Accordingly, after receiving the secondary node addition request message, the first node sends a secondary node addition request acknowledgement (SN addition request acknowledgment) message to the second node, where the secondary node addition response message is used to accept the addition of the first node as a secondary node for the terminal's first multi-connection. The secondary node addition response message includes configuration information of the secondary node (referred to as a first configuration for ease of description), where the first configuration is used for the secondary cell group for the first multi-connection. Furthermore, the first node saves the terminal's context (referred to as the terminal's SN context), where the terminal's SN context includes the first configuration and, optionally, other possible information, which is not specifically limited. After receiving the secondary node addition request acknowledgement message, the second node sends an RRC reconfiguration message to the terminal, where the RRC reconfiguration message includes the first configuration. The terminal can then establish a connection with the secondary node based on the first configuration, thereby completing the establishment of the first multi-connection. After completing the establishment of the first multiple connections, the second node and the first node use the first multiple connections to serve the terminal, that is, the second node and the first node transmit uplink data and / or downlink data of the terminal through multiple connections.

[0108] Optionally, the secondary node addition request message includes available identification information of the SN terminated RB. Accordingly, when the first node accepts adding the first node as the first multi-connected secondary node, the first node may select one or more identification information from the available identification information of the SN terminated RB and establish the SN terminated RB. For example, the available identification information of the SN terminated RB includes {RB identification 0, RB identification 1, RB identification 2, RB identification 3}. The first node may select {RB identification 0, RB identification 1} from the available identification information of the SN terminated RB and establish SN terminated RB0 and SN terminated RB1. The identification of SN terminated RB0 is RB identification 0, and the identification of SN terminated RB1 is RB identification 1. In this case, RB identification 0 and RB identification 1 are used RB identifications, and RB identification 2 and RB identification 3 are unused RB identifications. The RBs identified by the used RB identifications may be referred to as used RBs, that is, SN terminated RB0 and SN terminated RB1 are used RBs.

[0109] S302: The second node sends a message a1 to the first node. The message a1 is used to request to change the MN but not the SN for LTM. Correspondingly, the first node receives the message a1.

[0110] Exemplarily, the second node determines whether to initiate LTM configuration based on the measurement result reported by the terminal. In the case of determining to initiate LTM configuration, the second node sends a message a1 to the first node.

[0111] For example, message a1 includes information for LTM that changes the MN but not the SN, and optionally, further includes second identification information, the second identification information being associated with the first configuration, and the second identification information being identification information associated with the SN context of the terminal (such as the first configuration) recommended by the second node. Optionally, message a1 also includes identification information of at least one MN, and the identification information of the at least one MN is used to indicate that the SN will not be changed when the target node of the handover is one of the at least one MN. The at least one MN may include a candidate master node for the terminal handover, such as the third node and the fourth node described below.

[0112] In the embodiment of the present application, "not changing SN" can be understood as keeping the SN of the terminal, or keeping the context of the terminal at the SN. "Changing MN but not changing SN for LTM" can be understood as changing the MN but not the SN.

[0113] S303: The first node sends a message a2 (ie, a fourth message) to the second node. The message a2 is used to accept the MN change but not the SN change for the LTM. Accordingly, the second node receives the message a2.

[0114] Exemplarily, after receiving the message a1, the first node sends a message a2 to the second node based on the "information of changing the MN but not the SN for LTM" included in the message a1 and accepts the changing of the MN but not the SN for LTM.

[0115] For example, message a2 includes first identification information, and the first identification information is associated with the SN context of the terminal (such as the first configuration). The first identification information and the second identification information are different, that is, the first node does not accept the second identification information suggested by the second node, and reallocates a new identification information (that is, the first identification information) associated with the SN context of the terminal (such as the first configuration); or, the first identification information and the second identification information may be the same, that is, the first node accepts the second identification information suggested by the second node. In this case, message a2 may not include the first identification information. It is understandable that in other possible embodiments, message a1 may not include the second identification information, that is, the second node does not need to suggest the identification information associated with the first configuration to the first node.

[0116] Optionally, message a2 also includes identification information of the used RB and / or quality of service (QoS) flow information mapped to the used RB. The used RB terminates at the first node, that is, the used RB is an SN terminated RB, for example, the used RB includes SN terminated RB0 and SN terminated RB1, and the identification information of the used RB includes RB identification 0 and RB identification 1. The QoS flow information mapped to the used RB is, for example, a QoS flow identifier (QoS flow ID, QFI) mapped to the used RB.

[0117] Exemplarily, the message a1 may be a secondary node modification request (SN modification request) message, and the message a2 may be a secondary node modification request acknowledgement (SN modification request acknowledgement) message.

[0118] The above-mentioned steps S302 and S303 are optional, i.e., S302 and S303 may not be performed. For example, in S302 and S303, the first node and the second node determine, through negotiation, the identification information associated with the SN context of the terminal (such as the first configuration). When the identification information associated with the SN context of the terminal (such as the first configuration) is predefined identification information or is multiplexed with other identification information (such as multiplexing the identification information of the terminal), S302 and S303 may not be performed.

[0119] S304: The second node sends a message a3 to the third node. For example, the message a3 is a handover request message. Accordingly, the third node receives the handover request message.

[0120] Exemplarily, when the second node determines to initiate LTM configuration, if the second node determines the first cell as a candidate main cell for terminal switching (the first cell is located at the third node, that is, the third node is determined as a candidate main node for terminal switching), it sends a switching request message to the third node.

[0121] For example, message a3 includes identification information of the first cell (for example, the cell global identifier (CGI) of the first cell), the first identification information, and identification information of the secondary node (such as the ID of the secondary node, that is, the ID of the first node); wherein the first identification information and the identification information of the secondary node are used to trigger the third node to initiate SN addition without changing the SN, and the identification information of the first cell is used to request the third node to configure the first cell as a candidate primary cell for terminal switching. Optionally, message a3 also includes at least one of the identification of the MN terminated RB, the QoS flow information mapped to the MN terminated RB, the identification of the SN terminated RB, or the QoS flow information mapped to the SN terminated RB.

[0122] S305, the third node sends a first message to the first node, the first message is used to request that the first node be added as the second multi-connected auxiliary node of the terminal (i.e., requesting the addition of an SN without changing the SN for the third node), and the main node of the second multi-connection is the third node; accordingly, the first node receives the first message.

[0123] Exemplarily, in response to the handover request message, the third node performs admission control to determine whether to serve as a candidate master node for the terminal, and to determine whether to add the first node as a secondary node of the second multi-connection of the terminal. If the third node determines to serve as a candidate master node for the terminal, and determines to add the first node as a secondary node of the second multi-connection of the terminal, the first message is sent to the first node and the handover request of the handover request message is accepted; alternatively, if the third node determines to serve as a candidate master node for the terminal, and determines not to add the first node as a secondary node of the second multi-connection of the terminal, the first message is not required to be sent to the first node, and the handover request of the handover request message is accepted; alternatively, if the third node determines not to serve as a candidate master node for the terminal, the first message is not required to be sent to the first node, and the handover request of the handover request message is rejected.

[0124] Taking "the third node determines to be a candidate master node for the terminal, and determines to add the first node as a secondary node of the second multi-connection of the terminal" as an example, the multi-connection currently serving the terminal is the first multi-connection, that is, when the third node sends the first message to the first node, the multi-connection serving the terminal is the first multi-connection. The second multi-connection is a candidate multi-connection serving the terminal, that is, a multi-connection that may serve the terminal in the future (after the third node sends the first message to the first node).

[0125] Exemplarily, the first message includes first identification information, i.e., the SN corresponding to the source master node (i.e., the second node) and the candidate master node (i.e., the third node) are the same. Further, optionally, the first message is also used to indicate that the LTM switching request of the master node is based on the addition of an SN for the third node without changing the SN.

[0126] S306 , in response to the first message, the first node sends a second message to the third node, where the second message is used to accept adding the first node as a secondary node of the second multi-connection; accordingly, the third node receives the second message.

[0127] Exemplarily, in response to the first message, the first node sends a second message to the third node if it is determined to accept adding the first node as a secondary node of the second multi-connection.

[0128] Among them, the second message includes configuration information of the secondary node (referred to as the second configuration for ease of description), and the second configuration corresponds to the first cell. The second configuration may be the same as the first configuration, that is, the first configuration is also used for the second multi-connected secondary cell group. Alternatively, the second configuration is different from the first configuration, that is, the SN configuration corresponding to the candidate primary cell is different from the first configuration; in this case, the SN context of the terminal also includes the second configuration, that is, the SN context of the terminal includes the first configuration and the SN configuration corresponding to the candidate primary cell (such as the second configuration corresponding to the first cell). It can be understood that the SN configurations corresponding to different candidate primary cells may be the same or different, and there is no specific limitation.

[0129] Furthermore, the third node may send the second configuration to the second node via message a4 below (see S307), and the second node may then send the second configuration to the terminal via an RRC reconfiguration message (see S312); after receiving the second configuration, the terminal may establish a connection with the secondary node according to the second configuration, thereby completing the establishment of the second multi-connection. It is understandable that the second multi-connection is a candidate multi-connection serving the terminal, that is, although the second multi-connection is established, the second multi-connection has not yet been used to serve the terminal.

[0130] Optionally, the second message includes first information, and the first information is used for the terminal to monitor the control channel of the first node after determining to use the second multi-connection service terminal, and the first information can be included in the second configuration. For example, the first information is used to indicate that the initial state of the second multi-connection secondary cell group is an activated state, and then the terminal can monitor the control channel of the first node after determining to use the second multi-connection service terminal based on the received first information. In addition, in other examples, if the first information is used to indicate that the initial state of the second multi-connection secondary cell group is a deactivated state, the terminal needs to wait for an indication from the second multi-connection master node after determining to use the second multi-connection service terminal (for example, when the second multi-connection master node activates the second multi-connection secondary cell group, the second multi-connection master node can send the indication to the terminal), and after receiving the indication, monitor the control channel of the first node.

[0131] Exemplarily, the first message is a secondary node adding request message, and the second message is a secondary node adding request confirmation message.

[0132] S307 , the third node sends a message a4 to the second node, for example, the message a4 is a handover request acknowledgement message; accordingly, the second node receives the message a4 .

[0133] Exemplarily, message a4 includes the LTM configuration of the first cell and the configuration information of the secondary node (i.e., the second configuration). The LTM configuration of the first cell includes at least one of a cell group configuration (e.g., group identification information corresponding to the first cell), a channel state information (CSI) resource configuration, a transmission configuration indication (TCI) state configuration, or a CSI report configuration, without limitation.

[0134] Optionally, message a4 also includes a candidate MN terminated RB configuration (i.e., a third-node terminated RB configuration). For example, for the MN terminated RB, the third node reconfigures the MN terminated RB as a third-node terminated RB. For example, the identification information of the third-node terminated RB and the identification information of the MN terminated RB may be the same, and the QoS flow information mapped to the third-node terminated RB and the QoS flow information mapped to the MN terminated RB may be the same.

[0135] S308 , the second node sends a message a5 to the fourth node, where the message a5 is a handover request message; accordingly, the fourth node receives the message a5 .

[0136] Exemplarily, when the second node determines to initiate LTM configuration, if the second node determines the second cell as a candidate primary cell for terminal switching (the second cell is located at the fourth node, that is, the fourth node is determined as a candidate primary node for terminal switching), it sends message a5 to the fourth node.

[0137] For example, message a5 includes identification information of the second cell, the first identification information, and identification information of the secondary node (such as the ID of the secondary node, i.e., the ID of the first node). The first identification information and the identification information of the secondary node are used to trigger the fourth node to initiate SN addition without changing the SN, and the identification information of the second cell is used to request the fourth node to configure the second cell as a candidate primary cell for terminal switching. Optionally, message a5 also includes at least one of the identification of the SN terminated RB, the QoS flow information mapped to the SN terminated RB, the identification of the MN terminated RB, or the QoS flow information mapped to the MN terminated RB.

[0138] S309, the fourth node sends the fifth message to the first node, and the fifth message is used to request that the first node be added as the third multi-connected auxiliary node of the terminal (that is, requesting the addition of SN without changing SN for the fourth node), and the main node of the third multi-connection is the fourth node; accordingly, the first node receives the fifth message.

[0139] Exemplarily, in response to message a5, the fourth node performs admission control to determine whether to serve as a candidate master node for the terminal and whether to add the first node as a secondary node of the third multi-connection of the terminal. If the fourth node determines to serve as a candidate master node for the terminal and determines to add the first node as a secondary node of the third multi-connection of the terminal, the fifth message is sent to the first node and the switching request of the switching request message is accepted; alternatively, if the fourth node determines to serve as a candidate master node for the terminal and determines not to add the first node as a secondary node of the third multi-connection of the terminal, the fifth message is not required to be sent to the first node and the switching request of the switching request message is accepted; alternatively, if the fourth node determines not to serve as a candidate master node for the terminal, the fifth message is not required to be sent to the first node and the switching request of the switching request message is rejected.

[0140] Taking "the fourth node determines to be a candidate master node for the terminal, and determines to add the first node as a secondary node of the third multi-connection of the terminal" as an example, the multi-connection currently serving the terminal is the first multi-connection, that is, when the fourth node sends the first message to the first node, the multi-connection serving the terminal is the first multi-connection. The third multi-connection is a candidate multi-connection serving the terminal, that is, a multi-connection that may serve the terminal in the future (after the fourth node sends the first message to the first node).

[0141] Exemplarily, the fifth message includes the first identification information, i.e., the SN corresponding to the source master node (i.e., the second node) and the candidate master node (i.e., the fourth node) are the same. Further optionally, the fifth message is also used to indicate that the SN addition is based on the LTM switching request of the master node for the fourth node without changing the SN.

[0142] S310, in response to the fifth message, the first node sends a sixth message to the fourth node, where the sixth message is used to refuse to add the first node as a secondary node of the third multi-connection (i.e., refuse to change the SN for the fourth node); accordingly, the fourth node receives the sixth message.

[0143] Exemplarily, in response to the fifth message, the first node sends a sixth message to the fourth node if it is determined to refuse to add the first node as a secondary node of the third multi-connection.

[0144] Exemplarily, the fifth message is a secondary node adding request message, and the sixth message is a secondary node adding request reject (SN addition request reject) message.

[0145] S311, the fourth node sends a message a6 to the second node, for example, the message a6 is a handover request confirmation message; accordingly, the second node receives the message a6.

[0146] Exemplarily, the message a6 includes the LTM configuration of the second cell, and the LTM configuration of the second cell may refer to the description of the LTM configuration of the first cell.

[0147] Optionally, message a6 also includes a candidate MN terminated RB configuration (i.e., the fourth node terminated RB configuration). Specifically, since the fourth node cannot establish multiple connections with the first node, in order to avoid data loss, a bearer termination change is required: for the SN terminated RB, the fourth node determines the bearer termination change (bearer termination change) and configures the SN terminated RB (such as SN terminated RB0 and SN terminated RB1) as the fourth node terminated RB (i.e., the node where the SN terminated RB is terminated is replaced with the fourth node), and then determines the fourth node terminated RB configuration, which includes the identifier of the fourth node terminated RB, and the identifier of the fourth node terminated RB is the same as the identifier of the SN terminated RB. In addition, for the MN terminated RB, the fourth node reconfigures the MN terminated RB to the fourth node terminated RB.

[0148] S312: The second node sends an RRC reconfiguration message to the terminal; accordingly, the terminal receives the RRC reconfiguration message.

[0149] Exemplarily, the RRC reconfiguration message includes the LTM configuration and the second configuration of the first cell (i.e., the content included in message a4), and also includes the LTM configuration of the second cell (i.e., the content included in message a6). The RRC reconfiguration message may also include other possible information, such as the third node terminated RB configuration and the fourth node terminated RB configuration, which are not specifically limited.

[0150] Optionally, after receiving the RRC reconfiguration message, the terminal may send an RRC reconfiguration completion message to the second node.

[0151] It can be understood that the above S302 to S312 can be understood as a configuration process, which is described by taking the "first cell (third node)" and the "second cell (fourth node)" as examples. In other embodiments, the configuration process includes a configuration process for the first cell, but does not include a configuration process for the second cell; or, the configuration process includes a configuration process for the second cell, but does not include a configuration process for the first cell; or, the configuration process includes a configuration process for the first cell and the second cell, and also includes a configuration process for other cells, without specific limitation. In addition, not all of the steps involved in the above S301 to S312 are steps that must be executed. For example, S305 and S306 can be executed separately, or S309 and S310 can be executed separately.

[0152] Optionally, the above method further includes S313-a to S315-a, or S313-b to S318-b:

[0153] S313 - a , the second node sends a handover command message 1 to the terminal; correspondingly, the terminal receives the handover command message 1 .

[0154] Handover Command Message 1 is used to instruct the terminal's primary node to switch to a third node. That is, Handover Command Message 1 is a handover command message for the primary node. For example, Handover Command Message 1 is used to instruct the terminal to switch to the first cell managed by the third node. In response to Handover Command Message 1, the terminal determines to use the second multiple connection for data transmission.

[0155] Exemplarily, the terminal may send measurement reports of one or more candidate cells to the second node. If the second node determines that the terminal should switch to the first cell managed by the third node based on the measurement reports of the one or more candidate cells, the second node sends a switching command message 1 to the terminal.

[0156] The handover command message 1 is a MAC control element (CE) and includes a configuration identifier of a first cell, which is a target primary cell for handover. Optionally, the handover command message 1 also includes TCI state identifier information, so that the terminal receives scheduling information on a corresponding beam of the first cell based on the TCI state identifier information.

[0157] S314 - a , the second node sends a switching notification message 1 to the third node; correspondingly, the third node receives the switching notification message 1 .

[0158] Exemplarily, the handover notification message 1 is used to indicate that a handover command message of the master node has been sent to the terminal, and the handover command message is used to instruct the master node of the terminal to switch to the first cell managed by the third node.

[0159] The handover notification message 1 includes identification information of the first cell and identification information of the TCI state, so that the third node can send scheduling information on the corresponding beam of the first cell based on the identification information of the TCI state. Optionally, the handover notification message 1 also includes identification information of the secondary node (i.e., identification information of the first node) and the first identification information.

[0160] S315 - a , the third node sends a third message to the first node, for example, the third message is a switching notification message 2 ; accordingly, in response to the switching notification message 2 , the first node determines to use the second multi-connection service terminal.

[0161] Here, the first node determining to use the second multi-connection serving terminal may refer to the first node determining that the first node continues to serve the terminal. The first node continuing to serve the terminal may refer to the first node continuing to maintain the serving terminal, that is, before the first node receives the switching notification message 2, the first node is the serving terminal, and then in response to the switching notification message 2, the first node continues to maintain the serving terminal.

[0162] Exemplarily, the third node sends a switching notification message 2 to the first node based on the identification information of the auxiliary node (i.e., the identification information of the first node) and the first identification information. The switching notification message 2 is used to instruct the main node of the terminal to switch to the third node (i.e., the terminal switches to the first cell managed by the third node). The switching notification message 2 includes the first identification information and the identification information of the first cell. The first identification information is used by the first node to identify the SN context of the terminal, and the identification information of the first cell is used by the first node to identify the second configuration corresponding to the first cell in the SN context of the terminal. For example, different candidate main cells correspond to different SN configurations. Therefore, it is necessary to provide the first node with the identification information of the target main cell currently switched (i.e., the identification information of the first cell) so that the first node can determine the SN configuration corresponding to the target main cell currently switched.

[0163] Optionally, Handover Notification Message 2 further includes cause information, where the cause information is used to indicate that the reason for sending Handover Notification Message 2 is that an LTM handover occurred at the master node. For example, the first message described above is based on the master node's LTM handover request for the third node not to change the SN. Therefore, when Handover Notification Message 2 includes the cause information indicating that an LTM handover occurred at the master node, the first node can determine the corresponding SN configuration.

[0164] In addition, as a possible implementation (implementation method 1), when the second configuration includes the first information, if the first information indicates that the initial state of the second multi-connected secondary cell group is an activated state, then after the first node determines to use the second multi-connected service terminal, the second multi-connected secondary cell group can be activated; when the second configuration includes the first information, if the first information indicates that the initial state of the second multi-connected secondary cell group is a deactivated state, then after the first node determines to use the second multi-connected service terminal, the second multi-connected secondary cell group can be deactivated. Wherein, the first node manages the second multi-connected secondary cell group, and when the second multi-connected secondary cell group is in an activated state, the first node can transmit data with the terminal on the second multi-connected secondary cell group, and when the second multi-connected secondary cell group is in a deactivated state, the first node cannot transmit data with the terminal on the second multi-connected secondary cell group.

[0165] As another possible implementation (implementation method 2), the third node may also send an activation request to the first node (for example, the handover notification message 2 includes an activation request), the activation request is used to request activation of the second multi-connected secondary cell group; accordingly, after the first node determines to use the second multi-connection service terminal, it activates the second multi-connected secondary cell group in response to the activation request. Alternatively, the third node may also send a deactivation request to the first node (for example, the handover notification message 2 includes a deactivation request), the deactivation request is used to deactivate the second multi-connected secondary cell group; accordingly, after the first node determines to use the second multi-connection service terminal, it deactivates the second multi-connected secondary cell group in response to the deactivation request. In this way, the third node can activate or deactivate the second multi-connected secondary cell group according to actual needs; for example, when the amount of data to be transmitted is large, the third node can activate the second multi-connected secondary cell group to improve transmission efficiency, and when the amount of data to be transmitted is small, the third node can deactivate the second multi-connected secondary cell group.

[0166] It should be noted that if the first configuration and the second configuration are the same, that is, the first multi-connected secondary cell group and the second multi-connected secondary cell group can be understood as the same secondary cell group. In this case, before the first node activates the second multi-connected secondary cell group, if the first multi-connected secondary cell group is in an activated state, then "the first node activates the second multi-connected secondary cell group" can be understood as "the first node maintains the activated state of the second multi-connected secondary cell group" or "the first node reactivates the activated state of the second multi-connected secondary cell group"; similarly, before the first node deactivates the second multi-connected secondary cell group, if the first multi-connected secondary cell group is in a deactivated state, then "the first node deactivates the second multi-connected secondary cell group" can be understood as "the first node maintains the deactivated state of the second multi-connected secondary cell group" or "the first node reactivates the second multi-connected secondary cell group". That is, taking "activate X" as an example, "activate X" in the embodiments of the present application can refer to performing the operation of activating X, or it can also refer to maintaining the activated state of X.

[0167] As another possible implementation (Implementation 3), assuming that the first configuration and the second configuration are the same, that is, the first multi-connected secondary cell group and the second multi-connected secondary cell group can be understood as the same secondary cell group, the second node can send the current state information of the secondary cell group to the third node. For example, the handover notification message 1 includes the current state information of the secondary cell group. Accordingly, the third node can obtain the current state of the secondary cell group based on the current state information of the secondary cell group. Furthermore, when the third node determines that the secondary cell group needs to be activated, if the current state of the secondary cell group is activated, there is no need to send an activation request; if the current state of the secondary cell group is deactivated, an activation request is sent. When the third node determines that the secondary cell group needs to be deactivated, if the current state of the secondary cell group is deactivated, there is no need to send a deactivation request; if the current state of the secondary cell group is activated, a deactivation request is sent. Compared to Implementation 2, in Implementation 3, because the second node sends the current state information of the secondary cell group to the third node, the third node can send an activation request or deactivation request in a targeted manner based on the current state information of the secondary cell group.

[0168] In the above-mentioned implementation method 2 or implementation method 3, when the third node sends an activation request to the first node, the third node may send an instruction to the terminal to instruct the terminal to monitor the control channel of the first node; when the third node sends a deactivation request to the first node, the third node may send an instruction to the terminal to instruct the terminal to stop monitoring the control channel of the first node.

[0169] In addition, S315-a may be replaced by S315-a', where S315-a': the second node sends a third message to the first node, for example, the third message is handover notification message 3; accordingly, in response to handover notification message 3, the first node determines to use the second multi-connection service terminal. Handover notification message 3 includes the first identification information and identification information of the first cell. The functions of the first identification information and the identification information of the first cell can be referred to the description of handover notification message 2.

[0170] S313 - b , the second node sends a handover command message 2 to the terminal; accordingly, the terminal receives the handover command message 2 .

[0171] Handover Command Message 2 is used to instruct the terminal's master node to switch to the fourth node. That is, Handover Command Message 2 is a handover command message for the master node. For example, Handover Command Message 2 is used to instruct the terminal to switch to the second cell managed by the fourth node. Handover Command Message 2 can refer to the relevant description of Handover Command Message 1.

[0172] S314 - b , the second node sends a switching notification message 4 to the fourth node; accordingly, the fourth node receives the switching notification message 4 .

[0173] Exemplarily, the handover notification message 4 is used to indicate that a handover command message of the master node has been sent to the terminal, and the handover command message is used to instruct the master node of the terminal to switch to the second cell managed by the fourth node.

[0174] The handover notification message 4 includes identification information of the second cell and, optionally, identification information of the TCI state, so that the fourth node can send scheduling information on the corresponding beam of the second cell based on the identification information of the TCI state. Optionally, the handover notification message 4 also includes identification information of the secondary node (i.e., identification information of the first node) and the first identification information.

[0175] S315 - b , the fourth node sends a switching notification message 5 to the first node; correspondingly, the first node receives the switching notification message 5 .

[0176] Exemplarily, the fourth node sends a switching notification message 5 to the first node based on the identification information of the secondary node (i.e., the identification information of the first node) and the first identification information in the switching notification message 4, and the switching notification message 5 is used to instruct the main node of the terminal to switch to the fourth node (i.e., the terminal switches to the second cell managed by the fourth node). The switching notification message 5 includes the first identification information and the identification information of the second cell. Accordingly, after the first node receives the switching notification message 5, since the SN configuration corresponding to the second cell does not exist in the SN context of the terminal, the first node deactivates the secondary cell group managed by the first node (for example, before receiving the switching notification message 5, the first multi-connected secondary cell group is in an activated state, then the first multi-connected secondary cell group can be deactivated).

[0177] In addition, S315-b may be replaced by S315-b': the second node sends a handover notification message 6 to the first node; accordingly, the first node receives the handover notification message 6. The handover notification message 6 includes the first identification information and the identification information of the second cell.

[0178] S316 - b , the fourth node sends a handover command message 3 to the terminal; accordingly, the terminal receives the handover command message 3 .

[0179] Handover Command Message 3 is used to instruct the terminal's primary node to switch to the third node. That is, Handover Command Message 3 is a handover command message for the primary node. For example, Handover Command Message 3 is used to instruct the terminal to switch to the first cell managed by the third node. Handover Command Message 3 can refer to the relevant description of Handover Command Message 1. In response to Handover Command Message 3, the terminal determines to use the second multiple connection for data transmission.

[0180] S317 - b , the fourth node sends a switching notification message 7 to the third node; correspondingly, the third node receives the switching notification message 7 .

[0181] Exemplarily, the handover notification message 7 is used to indicate that a handover command message of the master node has been sent to the terminal, and the handover command message is used to instruct the master node of the terminal to switch to the first cell managed by the third node.

[0182] The handover notification message 7 includes the identification information of the first cell and, optionally, the identification information of the TCI state, so that the third node can send scheduling information on the corresponding beam of the first cell based on the identification information of the TCI state. Optionally, the handover notification message 7 also includes the identification information of the secondary node (i.e., the identification information of the first node) and the first identification information.

[0183] Optionally, the fourth node may also send the sequence number status information of the used RB to the third node, for example, the switching notification message 7 also includes the sequence number status information of the used RB. The used RB terminates at the first node, for example, the used RB includes SN terminated RB0 and SN terminated RB1. Since the fourth node configures the SN terminated RB (such as SN terminated RB0 and SN terminated RB1) as the fourth node terminated RB in the configuration phase, the fourth node may send the sequence number status information of the used RB to the target master node of the switching (i.e., the third node), which is then sent to the first node by the third node. For example, the third node sends the sequence number status information of the used RB to the first node via the switching notification message 8 described below. Furthermore, the first node determines the PDCP receiving window based on the sequence number status information of the used RB, specifically, the bottom of the receiving window points to the next unsuccessfully received sequence number.

[0184] S318-b, the third node sends a third message to the first node, such as the third message switching notification message 8; accordingly, in response to the switching notification message 8, the first node determines to use the second multi-connection service terminal.

[0185] Here, the first node determines to use the second multi-connection service terminal, which may refer to the first node determining that the first node continues to serve the terminal. The first node continuing to serve the terminal may refer to the first node changing from a non-service terminal to a service terminal, that is, before the first node receives the switching notification message 8, the first node is a non-service terminal, and in response to the switching notification message 8, the first node changes from a non-service terminal to a service terminal. Specifically, when the main node of the terminal is the second node, the first node and the second node use the first multi-connection service terminal; when the main node of the terminal is switched from the second node to the fourth node, the fourth node uses a single connection service terminal, and at this time the first node does not serve the terminal; when the main node of the terminal is switched from the fourth node to the third node, the first node and the third node use the second multi-connection service terminal, that is, the first node continues to serve the terminal (at this time, the first node changes from a non-service terminal to a service terminal).

[0186] For example, the specific implementation of S318 - b may refer to the description of S315 - a .

[0187] In addition, S318-b may be replaced by S318-b', where S318-b': the fourth node sends a third message to the first node, such as a third message, a handover notification message 9; accordingly, in response to the handover notification message 9, the first node determines to use the second multi-connection service terminal. The handover notification message 9 includes the first identification information and the identification information of the first cell. The functions of the first identification information and the identification information of the first cell can be referred to the description of the handover notification message 8.

[0188] Using the above method, during the configuration stage, the candidate master node can add the first node as a candidate multi-connection secondary node, that is, the secondary node addition process can be executed in advance, so that when the main node of the terminal is switched, the target master node does not need to execute the secondary node addition process again (for example, the above method introduces the activation and deactivation mechanism of the secondary cell group. When switching to the main node that is not configured with multiple connections, the secondary cell group can be deactivated. When switching to the main node that is configured with multiple connections, the secondary cell group can be activated without the need to execute the secondary node addition process), which facilitates the rapid recovery of data transmission of the secondary node, reduces the delay of the secondary node in resuming data transmission, and avoids business interruption.

[0189] In addition, in the above method, the first node can allocate first identification information associated with the SN context of the terminal and send it to the second node. The second node sends the first identification information to different candidate master nodes, and then regardless of whether the candidate master node is configured with multiple connections, it can communicate with the first node based on the first identification information.

[0190] The following describes the implementation of secure communication between the first node and the terminal in the above process.

[0191] (1) Security Solution 1

[0192] The initial source master node (i.e., the second node) sends security information 1 to the first node. The security information 1 includes N key information. The N key information is associated with at least one candidate multi-connection of the terminal. The candidate multi-connection is a candidate multi-connection serving the terminal. For example, at least one candidate multi-connection includes the second multi-connection, and may also include other candidate multi-connections (such as the fourth multi-connection, the master node of the fourth multi-connection is the fifth node, and the first node accepts to add the first node as the auxiliary node of the fourth multi-connection), that is, the N key information is associated with the second multi-connection and the fourth multi-connection, or the second multi-connection and the fourth multi-connection share N key information.

[0193] The N key information may be determined based on the key information of the second node. There are many specific implementations of the second node sending the security information 1 to the first node. For example, the second node sends the security information 1 to the first node through the above message a1.

[0194] The security information 1 also includes N counter values, each of which is associated with the N key information. The counter values ​​may also be replaced with other possible expressions, which are not specifically limited. After receiving the security information 1, the first node may send the N counter values ​​encapsulated in the auxiliary node format to the second node (for example, the N counter values ​​encapsulated in the auxiliary node format are included in the second configuration). After receiving the N counter values ​​encapsulated in the auxiliary node format, the second node may send the N counter values ​​encapsulated in the auxiliary node format to the terminal.

[0195] In this way, after the master node of the terminal is switched, the first node can communicate securely with the terminal. For example, after the master node of the terminal is switched to the third node, the first node can communicate securely with the terminal.

[0196] Specifically, from the perspective of the first node: the first node determines to replace key information and uses the first key information to communicate with the terminal. The first key information is unused key information among the N key information. For example, the first node performs PDCP re-establishment and then uses the first key information to communicate with the terminal. In the embodiments of the present application, "unused key information" can be understood as a fresh key.

[0197] There are various scenarios in which the first node determines to replace key information. For example, if the first node determines, based on a handover notification message, that the primary node of the terminal has switched, and the target primary node of the handover is configured with multiple connections, the first node can determine to replace key information. For another example, assuming that the SN configurations corresponding to the candidate primary cells are the same as the first configuration, the first node can determine to replace key information when it determines that the secondary cell group has switched from a deactivated state to an activated state.

[0198] The N key information are sorted in a first order, where the first key information is the first unused key information among the N key information. For example, the N key information are key information 1, key information 2, and key information 3, key information 1 is the used key information (for example, during the previous master node switch of the terminal, the key information used by the first node was key information 1). The remaining key information is unused key information, and the first key information is key information 2. The first order is the order of the count values ​​corresponding to the N key information from small to large, or other possible order.

[0199] From the perspective of the terminal: The terminal can communicate with the first node using the first count value, where the first count value is an unused count value among the N count values, and the first count value is associated with the first key information. For example, the terminal can derive the first key information based on the first count value using the key of the second node, and then use the first key information to communicate with the first node.

[0200] (2) Security Solution 2

[0201] The third node sends security information 2 to the first node. The security information 2 includes N key information, and the N key information is associated with the second multiple connection of the terminal. The N key information can be determined based on the key information of the third node. There are various specific implementations for the third node sending security information 2 to the first node, such as the third node sending security information 2 to the first node via the first message described above.

[0202] The security information 2 also includes N count values, which are associated one-to-one with the N key information. After the first node receives the security information 2, it can send the N count values ​​encapsulated in the auxiliary node format to the third node (for example, the N count values ​​encapsulated in the auxiliary node format are included in the second configuration). After the third node receives the N count values ​​encapsulated in the auxiliary node format, it sends the N count values ​​encapsulated in the auxiliary node format to the terminal.

[0203] In this way, each time the terminal's master node switches to the third node, the first node can use the unused key information in the N key information to communicate securely with the terminal. For example, the N key information are key information 1, key information 2, and key information 3. After completing the configuration process (such as S302 to S312), when the terminal's master node switches to the third node for the first time, the first node can use key information 1 to communicate securely with the terminal; when the terminal's master node switches to the third node for the second time, the first node can use key information 2 to communicate securely with the terminal, and so on. The processing on the terminal side can refer to the description in Security Solution 1.

[0204] It is understood that the above example uses the third node as an example. Other candidate master nodes may also send security information to the first node. In other words, different candidate master nodes are assigned their own security information, which is different from Security Solution 1 (Security Solution 1, in which the initial source master node assigns security information, without requiring candidate master nodes to assign security information). In addition, the amount of key information assigned to different candidate master nodes can be the same or different, without specific limitation.

[0205] (3) Security Solution 3

[0206] When the master node of the terminal switches, the target master node of the switch is a candidate master node configured with multiple connections, and the source master node of the switch sends a second count value to the terminal, such as the source master node of the switch sends the second count value to the terminal through a switch command message. And, the source master node of the switch sends the second key information to the target master node of the switch, and then the target master node sends the second key information to the first node, such as the source master node of the switch sends the second key information to the target master node of the switch through a switch notification message (such as the above-mentioned switch notification message 1), and then the target master node sends the second key information to the first node through a switch notification message (such as the above-mentioned switch notification message 2). Alternatively, the source master node of the switch sends the second key information to the first node, such as the source master node of the switch sends the second key information to the first node through a switch notification message (such as the above-mentioned switch notification message 3). Wherein, the second count value is associated with the second key information, and the second key information is determined according to the key of the source master node of the switch. In this way, the terminal uses the key of the source master node of the switch to deduce the second key information based on the second count value, and then the first node and the terminal use the second key information to communicate securely.

[0207] Alternatively, when the master node of the terminal is switched, the target master node of the switch is a candidate master node configured with multiple connections, and the target master node of the switch sends a second count value to the terminal, for example, after the terminal switches to the target master node, the target master node sends the second count value to the terminal. Also, the target master node of the switch sends the second key information to the first node, for example, the target master node of the switch sends the second key information to the first node through a switch notification message (such as the above-mentioned switch notification message 2). Among them, the second count value is associated with the second key information, and the second key information is determined based on the key of the target master node of the switch. In this way, the terminal uses the key of the switched source master node to deduce the second key information based on the second count value, and then the first node and the terminal use the second key information for secure communication.

[0208] In the embodiments of the present application, "the terminal and the first node communicate using key information (such as the first key information)" may mean: the terminal and the first node communicate using the first key information itself; or it may mean: the terminal and the first node communicate using Krrc and / or Kup derived based on the first key information. Krrc is used for encryption, decryption, and integrity protection of control messages, and Kup is used for encryption, decryption, and integrity protection of user data. The specific implementation of the terminal and the first node communicating using the second key information can refer to the description of the terminal and the first node communicating using the first key information.

[0209] With respect to the above embodiment, it can be understood that:

[0210] (1) The above embodiment describes the implementation process of the embodiment of the present application from the perspective of communication between the network node and the terminal. Among them, when the network node includes a CU and one or more DUs, the specific implementation process may also include communication between the CU and the DU. For example, the above-mentioned first node can be replaced by the first CU, the second node can be replaced by the second CU, the third node can be replaced by the third CU, and the fourth node can be replaced by the fourth CU; wherein, after the target master node of the switch (such as the third CU) receives the switch notification message (such as the switch notification message 1), it can forward part or all of the content of the switch notification message (such as the identification information of the first cell, the identification information of the TCI state) to the DU managed by the third CU, and after the first CU receives the switch notification message (such as the switch notification message 2), it can forward part or all of the content of the switch notification message (such as the identification information of the first cell, the activation request or the deactivation request) to the DU managed by the first CU. Other processes can refer to the description of the above embodiment.

[0211] (2) In any embodiment of the present invention, "in response to A (message), execute B (action)" can be understood as "according to A, execute B" or "because of A, execute B." The message names described in the embodiments of the present invention are only examples and are not intended to be limiting.

[0212] (3) In the various embodiments of this application, unless otherwise specified or logically conflicting, the terms and / or descriptions between different embodiments are consistent and may be referenced to each other. The technical features in different embodiments may be combined to form new embodiments based on their inherent logical relationships. In addition, within the same embodiment, different implementations or different examples may also reference or refer to each other.

[0213] (4) The various numerical numbers involved in this application are only for the convenience of description and are not intended to limit the scope of this application. The step numbers in the above flowcharts are only examples of the execution process and do not constitute a restriction on the order of execution of the steps. That is, the size of the step numbers does not mean the order of execution. The execution order of each step should be determined by its function and internal logic. In addition, not all the steps shown in the flowcharts are required to be executed. Some steps can be added or deleted based on actual needs.

[0214] The above mainly introduces the solution provided by the embodiment of the present application from the perspective of the interaction between the network node and the terminal side device. It is understandable that in order to realize the above functions, the network node and the terminal side device may include hardware structures and / or software modules corresponding to the execution of each function. It should be easily appreciated by those skilled in the art that, in combination with the units and algorithm steps of the various examples described in the embodiments disclosed herein, the embodiments of the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0215] In the embodiments of the present application, the network nodes and terminal-side devices can be divided into functional units according to the above-mentioned method examples. For example, different functional units can be divided according to different functions, or two or more functions can be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or software functional units.

[0216] In the case of adopting an integrated unit, Figure 4 shows a possible exemplary block diagram of the device involved in the embodiments of the present application. As shown in Figure 4, the device 400 may include: a processing unit 402 and a communication unit 403. The processing unit 402 is used to control and manage the actions of the device 400. The communication unit 403 is used to support the communication between the device 400 and other devices. Optionally, the communication unit 403 is also called a transceiver unit, and may include a receiving unit and / or a sending unit, which are used to perform receiving and sending operations respectively. The device 400 may also include a storage unit 401 for storing program code and / or data of the device 400.

[0217] (1) The apparatus 400 may be a network node (e.g., the first node) in the above-described embodiments. The processing unit 402 may support the apparatus 400 in executing the actions of the first node in each of the above-described method examples. Alternatively, the processing unit 402 primarily executes the internal actions of the first node in the method examples, and the communication unit 403 may support communication between the apparatus 400 and other devices.

[0218] For example, in one embodiment, the communication unit 403 is used to: receive a first message from a third node, the first message is used to request that the first node be added as a secondary node of the second multi-connection of the terminal, the multi-connection currently serving the terminal is the first multi-connection, the main node of the first multi-connection is the second node, and the secondary node of the first multi-connection is the first node; in response to the first message, send a second message to the third node, the second message is used to accept the addition of the first node as a secondary node of the second multi-connection, the second multi-connection is a candidate multi-connection serving the terminal, the main node of the second multi-connection is the third node, and the third node is a candidate primary node for the terminal to switch.

[0219] In one possible design, the communication unit 403 is further used to: receive a third message, where the third message is used to instruct the main node of the terminal to switch to the third node; and in response to the third message, determine to use the second multi-connection service to serve the terminal.

[0220] In one possible design, the third message is also used to request activation of the second multi-connected secondary cell group, and the first node manages the secondary cell group; the processing unit 402 is used to: activate the second multi-connected secondary cell group in response to the third message; or, the third message is also used to request deactivation of the second multi-connected secondary cell group; the processing unit 402 is used to: deactivate the second multi-connected secondary cell group in response to the third message.

[0221] In one possible design, the communication unit 403 is also used to: receive security information from the second node or the third node, the security information including N key information, the N key information being associated with the second multi-connection; N is an integer greater than or equal to 1; after determining that the second multi-connection is a service multi-connection of the terminal, the processing unit 402 is used to: communicate with the terminal using the first key information, the first key information being unused key information among the N key information.

[0222] In one possible design, the security information also includes N count values, and the N key information and the N count values ​​are associated one-to-one; the communication unit 403 is also used to: send the N count values ​​encapsulated in the auxiliary node format to the terminal through the third node.

[0223] In one possible design, the third message also includes second key information; after determining that the second multi-connection is the service multi-connection of the terminal, the processing unit 402 is used to: communicate with the terminal using the second key information.

[0224] In one possible design, the first message includes first identification information, the first identification information is associated with a first configuration, and the first configuration is used for the first multi-connected secondary cell group; the processing unit 402 is used to: determine that the first configuration is also used for the second multi-connected secondary cell group; wherein the first node manages the first multi-connected secondary cell group and the second multi-connected secondary cell group.

[0225] In one possible design, the communication unit 403 is also used to: send a fourth message to the second node, the fourth message including at least one of the following: first identification information, the first identification information is associated with a first configuration, the first configuration is used for the first multi-connected secondary cell group; identification information of a used RB, the used RB terminates at the first node; QoS flow information mapped to the used RB.

[0226] In one possible design, the communication unit 403 is also used to: receive a fifth message from a fourth node, the fifth message being used to request that the first node be added as a third multi-connected secondary node of the terminal, the third multi-connected primary node being the fourth node, and the fourth node being a candidate primary node for the terminal to switch; in response to the fifth message, send a sixth message to the fourth node, the sixth message being used to refuse to add the first node as a third multi-connected secondary node.

[0227] (2) The apparatus 400 may be a network node (e.g., a third node) in the above-described embodiments. The processing unit 402 may support the apparatus 400 in executing the actions of the third node in each of the above-described method examples. Alternatively, the processing unit 402 primarily executes the internal actions of the third node in the method examples, and the communication unit 403 may support communication between the apparatus 400 and other devices.

[0228] For example, in one embodiment, the communication unit 403 is used to: send a first message to a first node, the first message is used to request that the first node be added as a secondary node of the second multi-connection of the terminal, the multi-connection currently serving the terminal is the first multi-connection, the main node of the first multi-connection is the second node, and the secondary node of the first multi-connection is the first node; receive a second message from the first node, the second message is used to accept the addition of the first node as a secondary node of the second multi-connection, the second multi-connection is a candidate multi-connection serving the terminal, the main node of the second multi-connection is the third node, and the third node is a candidate primary node for the terminal to switch.

[0229] In a possible design, the communication unit 403 is further used to: send a third message to the first node, where the third message is used to instruct the main node of the terminal to switch to the third node.

[0230] In one possible design, the communication unit 403 is further used to: send security information, where the security information includes N key information, and the N key information is associated with the second multiple connections; N is an integer greater than or equal to 1.

[0231] In one possible design, the security information also includes N count values, and the N key information and the N count values ​​are associated one-to-one; the communication unit 403 is also used to: receive the N count values ​​encapsulated in the auxiliary node format from the first node; and send the N count values ​​encapsulated in the auxiliary node format to the terminal through the second node.

[0232] In one possible design, the communication unit 403 is also used to: receive first identification information from the second node, the first identification information is associated with a first configuration, and the first configuration is used for the first multi-connected secondary cell group; wherein the first message includes the first identification information.

[0233] In one possible design, the communication unit 403 is also used to: receive sequence number status information of a used RB, where the used RB terminates at the first node; and send the sequence number status information to the first node, where the sequence number status information is used to determine a receiving window of a packet data convergence layer protocol PDCP.

[0234] (3) The apparatus 400 may be a network node (e.g., the fourth node) in the above-described embodiments. The processing unit 402 may support the apparatus 400 in executing the actions of the fourth node in each of the above-described method examples. Alternatively, the processing unit 402 primarily executes the internal actions of the fourth node in the method examples, and the communication unit 403 may support communication between the apparatus 400 and other devices.

[0235] For example, in one embodiment, the communication unit 403 is used to: send a fifth message to the first node, the fifth message is used to request that the first node be added as a secondary node of the third multi-connection of the terminal, the multi-connection currently serving the terminal is the first multi-connection, the main node of the first multi-connection is the second node, and the secondary node of the first multi-connection is the first node; receive a sixth message from the first node, the sixth message is used to refuse to add the first node as a secondary node of the third multi-connection, the third multi-connection is a candidate multi-connection serving the terminal, the main node of the third multi-connection is the fourth node, and the fourth node is a candidate primary node for the terminal to switch.

[0236] (4) The apparatus 400 may be a network node (e.g., a second node) in the above-described embodiments. The processing unit 402 may support the apparatus 400 in executing the actions of the second node in each of the above-described method examples. Alternatively, the processing unit 402 may primarily execute the internal actions of the second node in the method examples, and the communication unit 403 may support communication between the apparatus 400 and other devices.

[0237] For example, in one embodiment, the communication unit 403 is used to: receive a fourth message from a first node, the fourth message including first identification information, the first identification information being associated with a first configuration, the first configuration being used for a first multi-connection secondary cell group of a terminal; the multi-connection currently serving the terminal is the first multi-connection, the main node of the first multi-connection is the second node, and the secondary node of the first multi-connection is the first node; and send the first identification information to a third node, the third node being a candidate main node for switching.

[0238] (5) The apparatus 400 may be a terminal-side apparatus (e.g., a terminal) in the above-described embodiments. The processing unit 402 may support the apparatus 400 in executing the terminal actions in the above-described method examples. Alternatively, the processing unit 402 primarily executes the internal actions of the terminal in the method examples, and the communication unit 403 may support communication between the apparatus 400 and other devices.

[0239] For example, in one embodiment, the communication unit 403 is used to: receive N count values ​​encapsulated in a secondary node format, the N count values ​​are associated with a second multi-connection, the master node of the second multi-connection is the third node, the secondary node of the second multi-connection is the first node, and the third node is a candidate master node for switching; the processing unit 402 is used to: after the master node of the terminal side device is switched to the third node, use the first count value to communicate with the first node, and the first count value is an unused count value among the N count values.

[0240] In another embodiment, the communication unit 403 is used to: receive a switching command message, wherein the switching command message is used to instruct the main node of the terminal to switch to a third node, the third node is the second multi-connected main node of the terminal, and the second multi-connected auxiliary node is the first node; the switching command message includes a second count value; the processing unit 402 is used to: after the main node of the terminal side device is switched to the third node, use the second count value to communicate with the first node.

[0241] It should be understood that the division of units in the above device is merely a division of logical functions. In actual implementation, they can be fully or partially integrated into one physical entity, or they can be physically separated. Moreover, the units in the device can all be implemented in the form of software calling through processing elements; or they can all be implemented in the form of hardware; or some units can be implemented in the form of software calling through processing elements, and some units can be implemented in the form of hardware. For example, each unit can be a separately established processing element, or it can be integrated into a certain chip of the device. In addition, it can also be stored in the memory in the form of a program, called by a certain processing element of the device and execute the function of the unit. In addition, all or part of these units can be integrated together, or they can be implemented independently. The processing element described here can also be a processor, which can be an integrated circuit with signal processing capabilities. In the implementation process, each operation of the above method or each unit above can be implemented by the integrated logic circuit of the hardware in the processor element or in the form of software calling through the processing element.

[0242] In one example, the unit in any of the above devices may be one or more integrated circuits configured to implement the above method, such as one or more application specific integrated circuits (ASICs), or one or more digital singnal processors (DSPs), or one or more field programmable gate arrays (FPGAs), or a combination of at least two of these integrated circuit forms. For another example, when the unit in the device can be implemented in the form of a processing element scheduler, the processing element can be a processor, such as a general-purpose central processing unit (CPU), or other processor that can call a program. For another example, these units can be integrated together and implemented in the form of a system-on-a-chip (SOC).

[0243] The above-mentioned receiving unit is an interface circuit of the device, which is used to receive signals from other devices. For example, when the device is implemented as a chip, the receiving unit is the interface circuit of the chip used to receive signals from other chips or devices. The above-mentioned sending unit is an interface circuit of the device, which is used to send signals to other devices. For example, when the device is implemented as a chip, the sending unit is the interface circuit of the chip used to send signals to other chips or devices.

[0244] Referring to Figure 5, which is a schematic diagram of the structure of a network node provided in an embodiment of the present application, the network node can be applied to the communication system shown in Figure 1 to perform the functions of the network node in the above method embodiment. As shown in Figure 5, the network node 50 may include one or more DUs 501 and one or more CUs 502. The DU 501 may include at least one antenna 5011, at least one radio frequency unit 5012, at least one processor 5013 and at least one memory 5014. The DU 501 is mainly used for receiving and transmitting radio frequency signals, converting radio frequency signals into baseband signals, and partial baseband processing. The CU 502 may include at least one processor 5022 and at least one memory 5021.

[0245] The CU502 is primarily used for baseband processing and controlling network nodes. The DU501 and CU502 can be physically located together or separately, i.e., in a distributed base station. The CU502 is the control center of the network node, also known as a processing unit, and is primarily used to perform baseband processing. For example, the CU502 can be used to control the network node to execute the network node operation process described in the above method embodiments.

[0246] In addition, optionally, the network node 50 may include one or more radio frequency units, one or more DUs, and one or more CUs. The DU may include at least one processor 5013 and at least one memory 5014, the radio frequency unit may include at least one antenna 5011 and at least one radio frequency unit 5012, and the CU may include at least one processor 5022 and at least one memory 5021.

[0247] In one example, the CU502 may be composed of one or more single boards, and the multiple single boards may jointly support a wireless access network with a single access indication (such as a 5G network), or may respectively support wireless access networks with different access standards (such as an LTE network, a 5G network, or other networks). The memory 5021 and the processor 5022 may serve one or more single boards. That is, a memory and a processor may be separately set on each single board. It is also possible that multiple single boards share the same memory and processor. In addition, necessary circuits may be provided on each single board. The DU501 may be composed of one or more single boards, and the multiple single boards may jointly support a wireless access network with a single access indication (such as a 5G network), or may respectively support wireless access networks with different access standards (such as an LTE network, a 5G network, or other networks). The memory 5014 and the processor 5013 may serve one or more single boards. That is, a memory and a processor may be separately set on each single board. It is also possible that multiple single boards share the same memory and processor. In addition, necessary circuits may be provided on each single board.

[0248] The network node shown in Figure 5 is capable of implementing the various processes related to the network node in the above-described method embodiments. The operations and / or functions of the various modules in the network node shown in Figure 5 are for implementing the corresponding processes in the above-described method embodiments. For details, please refer to the description of the above-described method embodiments; to avoid repetition, detailed descriptions are omitted here.

[0249] Refer to Figure 6, which is a structural diagram of a terminal-side device (such as a terminal) provided in an embodiment of the present application. The terminal can be applied to the communication system shown in Figure 1 to implement the operation of the terminal in the above embodiment. As shown in Figure 6, the terminal includes: an antenna 610, a radio frequency part 620, and a signal processing part 630. The antenna 610 is connected to the radio frequency part 620. In the downlink direction, the radio frequency part 620 receives information sent by the network device through the antenna 610, and sends the information sent by the network device to the signal processing part 630 for processing. In the uplink direction, the signal processing part 630 processes the information of the terminal and sends it to the radio frequency part 620. The radio frequency part 620 processes the information of the terminal and sends it to the network device through the antenna 610.

[0250] The signal processing unit 630 may include a modem subsystem for processing data at various communication protocol layers; a central processing unit for processing the terminal operating system and application layers; and other subsystems, such as a multimedia subsystem for controlling the terminal's camera and screen display, and a peripheral subsystem for connecting to other devices. The modem subsystem may be a separate chip.

[0251] The modem subsystem may include one or more processing elements 631, such as a main control CPU and other integrated circuits. Furthermore, the modem subsystem may include a storage element 632 and an interface circuit 633. Storage element 632 is used to store data and programs. However, the program used to execute the method executed by the terminal in the above method may not be stored in storage element 632, but rather in a memory external to the modem subsystem, and loaded by the modem subsystem when in use. Interface circuit 633 is used to communicate with other subsystems.

[0252] The modem subsystem can be implemented using a chip comprising at least one processing element and an interface circuit. The processing element is configured to execute each step of any of the methods performed by the terminal, and the interface circuit is configured to communicate with other devices. In one implementation, the unit that performs each step of the method can be implemented as a processing element scheduler. For example, the terminal device includes a processing element and a storage element, and the processing element invokes a program stored in the storage element to execute the method performed by the terminal in the above method embodiments. The storage element can be a storage element located on the same chip as the processing element, i.e., an on-chip storage element.

[0253] In another implementation, the program for executing the method executed by the terminal in the above method can be stored in a memory element on a different chip from the processing element, i.e., an off-chip memory element. In this case, the processing element calls or loads the program from the off-chip memory element to the on-chip memory element to call and execute the method executed by the terminal in the above method embodiment.

[0254] In another implementation, the unit implementing each step of the above method in the terminal may be configured as one or more processing elements, which are provided in the modem subsystem. The processing elements may be integrated circuits, such as one or more ASICs, one or more DSPs, one or more FPGAs, or a combination of these integrated circuits. These integrated circuits may be integrated together to form a chip.

[0255] The units that implement the various steps of the above method in the terminal can be integrated together and implemented in the form of a SOC chip, which is used to implement the above method. The chip can integrate at least one processing element and a storage element, and the processing element can call the program stored in the storage element to implement the above terminal execution method; alternatively, the chip can integrate at least one integrated circuit to implement the above terminal execution method; or, a combination of the above implementation methods can be used, with the functions of some units implemented by the processing element calling the program, and the functions of some units implemented by the integrated circuit.

[0256] As can be seen, the above-mentioned terminal device may include at least one processing element and an interface circuit, wherein the at least one processing element is used to execute any of the terminal-executed methods provided in the above method embodiments. The processing element may execute some or all of the steps executed by the terminal in a first manner: by calling a program stored in a storage element; or in a second manner: by combining hardware integrated logic circuits in the processor element with instructions to execute some or all of the steps executed by the terminal. Of course, the first and second manners may also be combined to execute some or all of the steps executed by the terminal.

[0257] The processing element here is the same as described above and can be implemented by a processor. The function of the processing element can be the same as that of the processing unit described in Figure 4. For example, the processing element can be a general-purpose processor, such as a CPU, or one or more integrated circuits configured to implement the above method, such as one or more ASICs, or one or more microprocessors (DSPs), or one or more FPGAs, or a combination of at least two of these integrated circuit forms. The storage element can be implemented by a memory, and the function of the storage element can be the same as that of the storage unit described in Figure 4. The storage element can be a single memory or a collective term for multiple memories.

[0258] The terminal shown in FIG6 is capable of implementing the various processes involved in the terminal in the above-described method embodiment. The operations and / or functions of the various modules in the terminal shown in FIG6 are for implementing the corresponding processes in the above-described method embodiment. For details, please refer to the description of the above-described method embodiment; to avoid repetition, detailed descriptions are omitted here.

[0259] An embodiment of the present application also provides a communication system, which includes the terminal in the above method embodiment, the first network device in the above method embodiment, and optionally, the third network device in the above method embodiment.

[0260] The terms "system" and "network" in the embodiments of the present application can be used interchangeably. "At least one" refers to one or more, and "plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, "at least one of A, B or C" includes A, B, C, AB, AC, BC or ABC, and "at least one of A, B and C" can also be understood to include A, B, C, AB, AC, BC or ABC. And, unless otherwise specified, the ordinal numbers such as "first" and "second" mentioned in the embodiments of the present application are used to distinguish multiple objects and are not used to limit the order, timing, priority or importance of multiple objects.

[0261] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, optical storage, etc.) that contain computer-usable program code.

[0262] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each flow and / or box in the flow chart and / or block diagram, as well as the combination of the flow chart and / or box in the flow chart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more flow charts and / or one or more boxes in the block diagram.

[0263] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0264] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

Claims

1. A communication method, characterized in that: The method is applied to a first node, and includes: receiving a first message from a third node, where the first message is used to request that the first node be added as a secondary node of a second multi-connection of a terminal, where the multi-connection currently serving the terminal is a first multi-connection, the primary node of the first multi-connection is the second node, and the secondary node of the first multi-connection is the first node; In response to the first message, a second message is sent to the third node, the second message being used to accept adding the first node as a secondary node of the second multi-connection, the second multi-connection being a candidate multi-connection serving the terminal, the primary node of the second multi-connection being the third node, and the third node being a candidate primary node for the terminal to switch.

2. The method according to claim 1, characterized in that The method further comprises: receiving a third message, where the third message is used to instruct the master node of the terminal to switch to the third node; In response to the third message, it is determined to use the second multi-connection service for the terminal.

3. The method according to claim 2, characterized in that The second message includes first information, where the first information is used by the terminal to monitor the control channel of the first node after the terminal determines to use the second multi-connection service to serve the terminal.

4. The method according to claim 2, characterized in that The third message is further used to request activation of the second multi-connected secondary cell group, and the first node manages the secondary cell group; the method further includes: activating the second multi-connected secondary cell group in response to the third message; or, The third message is further used to request deactivation of the second multi-connected secondary cell group; the method further includes: deactivating the second multi-connected secondary cell group in response to the third message.

5. The method according to any one of claims 2 to 4, characterized in that The method further comprises: receiving security information from the second node or the third node, the security information including N key information, the N key information being associated with the second multi-connection; N being an integer greater than or equal to 1; After determining that the second multi-connection is a service multi-connection of the terminal, the method further includes: communicating with the terminal using first key information, where the first key information is unused key information among the N key information.

6. The method according to claim 5, characterized in that The security information is carried in the first message.

7. The method according to claim 5 or 6, characterized in that The security information further includes N count values, and the N key information is associated one-to-one with the N count values; The method further includes: sending the N count values ​​encapsulated in a secondary node format to the terminal through the third node.

8. The method according to any one of claims 2 to 4, characterized in that The third message also includes second key information; After determining that the second multi-connection is a serving multi-connection of the terminal, the method further includes: communicating with the terminal using the second key information.

9. The method according to any one of claims 1 to 8, characterized in that The first message includes first identification information, where the first identification information is associated with a first configuration, and the first configuration is used for the first multi-connected secondary cell group; The method further comprises: determining that the first configuration is also used for the second multi-connected secondary cell group; The first node manages the first multi-connected secondary cell group and the second multi-connected secondary cell group.

10. The method according to any one of claims 1 to 9, characterized in that The method further comprises: Send a fourth message to the second node, where the fourth message includes at least one of the following: first identification information, where the first identification information is associated with a first configuration, where the first configuration is used for the first multi-connected secondary cell group; Identification information of a used radio bearer (RB), where the used RB ends at the first node; The quality of service (QoS) flow information mapped to the used RB.

11. The method according to any one of claims 1 to 10, characterized in that The method further comprises: receiving a fifth message from a fourth node, the fifth message being used to request that the first node be added as a secondary node of a third multi-connection of the terminal, the third multi-connection being a candidate multi-connection serving the terminal, the primary node of the third multi-connection being the fourth node, and the fourth node being a candidate primary node for handover by the terminal; In response to the fifth message, a sixth message is sent to the fourth node, where the sixth message is used to refuse to add the first node as a secondary node of the third multi-connection.

12. A communication method, characterized in that: The method is applied to a third node, and includes: Sending a first message to a first node, where the first message is used to request that the first node be added as a secondary node of a second multi-connection of a terminal, where the multi-connection currently serving the terminal is the first multi-connection, the primary node of the first multi-connection is the second node, and the secondary node of the first multi-connection is the first node; Receive a second message from the first node, the second message is used to accept the addition of the first node as a secondary node of the second multi-connection, the second multi-connection is a candidate multi-connection serving the terminal, the master node of the second multi-connection is the third node, and the third node is a candidate master node for the terminal to switch.

13. The method according to claim 12, characterized in that The method further comprises: A third message is sent to the first node, where the third message is used to instruct the primary node of the terminal to switch to the third node.

14. The method according to claim 13, characterized in that The third message is further used to request activation of the second multi-connected secondary cell group or deactivation of the second multi-connected secondary cell group, and the first node manages the secondary cell group.

15. The method according to any one of claims 12 to 14, characterized in that The method further comprises: Send security information, where the security information includes N key information, and the N key information is associated with the second multi-connection; N is an integer greater than or equal to 1.

16. The method according to claim 15, characterized in that The security information is carried in the first message.

17. The method according to claim 15 or 16, characterized in that The security information further includes N count values, and the N key information is associated one-to-one with the N count values; The method further comprises: receiving the N count values ​​encapsulated in a slave node format from the first node; The N count values ​​encapsulated in a secondary node format are sent to the terminal through the second node.

18. The method according to any one of claims 12 to 17, characterized in that The method further comprises: receiving first identification information from the second node, where the first identification information is associated with a first configuration, where the first configuration is used for the first multi-connected secondary cell group; The first message includes the first identification information.

19. The method according to any one of claims 12 to 18, characterized in that The method further comprises: receiving sequence number status information of a used RB, where the used RB ends at the first node; The sequence number status information is sent to the first node, where the sequence number status information is used to determine a receiving window of a packet data convergence layer protocol (PDCP).

20. A communication device, characterized in that: The method comprises a unit for performing the method according to any one of claims 1 to 11, or a unit for performing the method according to any one of claims 12 to 19.

21. A communication device, characterized in that: The communication device comprises a processor coupled to a memory, wherein a computer program is stored in the memory; the processor is used to call the computer program in the memory so that the communication device executes the method according to any one of claims 1 to 11, or the method according to any one of claims 12 to 19.

22. A communication system, characterized in that: The communication system includes a first node and a third node; wherein the first node is used to execute the method according to any one of claims 1 to 11, and the third node is used to execute the method according to any one of claims 12 to 19.

23. A computer-readable storage medium, characterized in that The storage medium stores a computer program or instruction. When the computer program or instruction is executed by a computer, the method according to any one of claims 1 to 11 is executed, or the method according to any one of claims 12 to 19 is executed.

24. A computer program product, characterized in that When a computer reads and executes the computer program product, the method according to any one of claims 1 to 11 is executed, or the method according to any one of claims 12 to 19 is executed.

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