Communication method and device

Abstract

According to the communication method and device provided by the invention, the terminal equipment only needs to be switched among different clusters in the moving process, so that the switching frequency of the terminal equipment can be reduced, and the communication experience of the terminal equipment is improved. The method comprises the following steps: a first access network device included in a source cluster currently accessed by a terminal device acquires first information, wherein the first information comprises identification information corresponding to at least one candidate access network device respectively included in a plurality of candidate clusters; the first access network device obtains first measurement report information indicating channel quality; and the first access network equipment sends a switching request message used for requesting to switch the terminal equipment from the source cluster to a target cluster, wherein the target cluster is determined from the plurality of candidate clusters according to the first information and the first measurement report information.

Description

Communication method and device Technical Field

[0001] The present application relates to the field of communications, and more particularly, to a communication method and apparatus. Background Art

[0002] In handover technology, as a terminal device moves, it must switch from one cell to another. In high-density network scenarios, due to the large number and density of base stations, the movement of terminal devices causes frequent handovers. Frequent handovers can lead to increased handover failure rates, increased risk of service interruption, increased signaling overhead, and wasted bandwidth, resulting in a poor communication experience for the terminal device.

[0003] Summary of the Invention

[0004] The present application provides a communication method and apparatus that can reduce the number of handovers of terminal devices, thereby improving the communication experience of the terminal devices.

[0005] In a first aspect, a communication method is provided, which can be performed by a first communication device. The method includes: the first communication device obtains first information, the first information including identification information corresponding to at least one candidate access network device included in multiple candidate clusters, the first communication device being an access network device included in a source cluster currently accessed by a second communication device; the first communication device obtains first measurement report information; the first communication device sends a handover request message, the handover request message is used to request that the second communication device be switched from the source cluster to a target cluster, the target cluster being determined based on the first information and the first measurement report information, the target cluster being included in the multiple candidate clusters. The first communication device can be a first access network device, or a chip or chip system in the first access network device, or a device used in conjunction with the first access network device; the second communication device can be a terminal device, or a chip or chip system in the terminal device, or a device used in conjunction with the terminal device.

[0006] Based on the above technical solution, the first access network device in the source cluster to which the terminal device is currently connected can obtain identification information (first information) corresponding to at least one candidate access network device included in each of the multiple candidate clusters; the first access network device determines to switch the terminal device from the source cluster to the target cluster based on the obtained first measurement report information and the first information; the first access network device initiates the switching process of switching the terminal device from the source cluster to the target cluster by sending a switching request message. Multiple access network devices within a cluster (source cluster / target cluster) can jointly serve the terminal device. The terminal device only needs to switch between different clusters during the movement process. Therefore, the number of switching times of the terminal device can be reduced, thereby improving the communication experience of the terminal device.

[0007] In certain implementations of the first aspect, the first communication device acquiring the first information includes: the first communication device receiving the first information from a third communication device. The third communication device may be the first controller, or a chip or chip system in the first controller.

[0008] In certain implementations of the first aspect, the first measurement report information indicates a channel quality of at least one candidate access network device included in each of the multiple candidate clusters.

[0009] In certain implementations of the first aspect, the method further includes: the first communications device sending second information to the second communications device, where the second information includes identification information corresponding to at least one candidate access network device included in each of the multiple candidate clusters; and the first communications device obtaining first measurement report information includes: the first communications device receiving the first measurement report information from the second communications device. The first measurement report information may be determined by the second communications device by measuring a downlink reference signal.

[0010] In certain implementations of the first aspect, the method further includes: the first communication device obtains second measurement report information, where the second measurement report information indicates the channel quality of the access network device included in the source cluster; and the first communication device sends a first request message to the third communication device based on the second measurement report information, where the first request message is used to obtain the first information.

[0011] In certain implementations of the first aspect, the first communication device obtaining the second measurement report information includes: the first communication device receiving the second measurement report information from the second communication device. The second measurement report information may be determined by the second communication device by measuring a downlink reference signal.

[0012] In certain implementations of the first aspect, the first information further includes priority information of the multiple candidate clusters, the target cluster is a candidate cluster among the multiple candidate clusters whose priority is greater than or equal to a preset threshold, and the first measurement report information indicates channel quality of access network devices included in the source cluster. A candidate cluster with a higher priority has better performance.

[0013] Based on the above scheme, the first information also includes priority information of multiple candidate clusters. The first communication device can determine the target cluster from multiple candidate clusters based on the first measurement report information and the priority information of multiple candidate clusters; and the performance of the target cluster is proportional to the priority. The priority of the determined target cluster is greater than or equal to the preset threshold, indicating that the performance of the target cluster is better, thereby improving the communication experience of the terminal device accessing the target cluster.

[0014] In certain implementations of the first aspect, the first communication device sending a handover request message includes: the first communication device sending the handover request message to a fourth communication device, where the fourth communication device is a candidate access network device included in the target cluster. The fourth communication device may be a second access network device, or a chip or chip system in the second access network device. In this case, the third communication device (first controller) is connected to the access network device included in the source cluster and the candidate access network devices included in the multiple candidate clusters.

[0015] The first information may also indicate identification information corresponding to the candidate access network device with the highest priority among at least one candidate access network device included in the candidate cluster.

[0016] In certain implementations of the first aspect, the first communication device sending the handover request message includes: the first communication device sending the handover request message to a third communication device. In this case, the third communication device (first controller) is connected to an access network device included in a source cluster, and the fifth communication device (second controller) is connected to candidate access network devices included in multiple candidate clusters.

[0017] In certain implementations of the first aspect, the candidate cluster satisfies at least one of the following: an average frequency efficiency of the at least one candidate access network device included in the candidate cluster is greater than or equal to a first threshold; an average throughput of the at least one candidate access network device included in the candidate cluster is greater than or equal to a second threshold; or an average communication rate of the at least one candidate access network device included in the candidate cluster is greater than or equal to a third threshold. The performance of the candidate cluster meeting certain conditions can improve the communication experience of terminal devices accessing the candidate cluster.

[0018] In certain implementations of the first aspect, the source cluster satisfies at least one of the following: a channel quality of at least one access network device included in the source cluster is greater than or equal to a first threshold; a throughput of the at least one access network device included in the source cluster is greater than or equal to a second threshold; or an average communication rate of the at least one access network device included in the source cluster is greater than or equal to a third threshold. If the performance of the source cluster meets certain conditions, the communication experience of terminal devices accessing the source cluster can be improved.

[0019] In a second aspect, a communication method is provided, which can be performed by a third communication device. The method includes: the third communication device determines first information, the first information including identification information corresponding to at least one candidate access network device included in multiple candidate clusters; the third communication device sends the first information to the first communication device, and the first communication device is an access network device included in the source cluster currently accessed by the second communication device. The first communication device can be a first access network device, or a chip or chip system in the first access network device, or a device used in conjunction with the first access network device; the second communication device can be a terminal device, or a chip or chip system in the terminal device, or a device used in conjunction with the terminal device; the third communication device can be a first controller, or a chip or chip system in the first controller, or a device used in conjunction with the first controller.

[0020] The method provided in the second aspect is a method on the third communication device side corresponding to the first aspect, and its beneficial effects can be directly referred to the first aspect.

[0021] In certain implementations of the second aspect, the third communication apparatus determines the first information, including: the third communication apparatus determines the first information based on channel quality information of the plurality of candidate access network devices.

[0022] In certain implementations of the second aspect, the method further includes: the third communication device receiving a first request message from the first communication device, where the first request message is used to obtain the first information.

[0023] In certain implementations of the second aspect, the first information further includes priority information of the multiple candidate clusters.

[0024] In certain implementations of the second aspect, the method further includes: the third communication device sending a second request message to a fifth communication device, the second request message being used to obtain channel quality information of the plurality of candidate access network devices; and the third communication device receiving the channel quality information of the plurality of candidate access network devices from the fifth communication device. The fifth communication device may be the second controller, or a chip or chip system within the second controller, or a device used in conjunction with the second controller.

[0025] In certain implementations of the second aspect, the method further includes: the third communication device receiving a switching request message from the first communication device, the switching request message being used to request that the second communication device be switched from the source cluster to the target cluster, the target cluster being included in the multiple candidate clusters; the third communication device sending a context establishment request message of the second communication device to the fifth communication device; and the third communication device receiving a context establishment request confirmation message of the second communication device from the fifth communication device.

[0026] In a third aspect, a communication method is provided, which can be performed by a second communication device. The method includes: the second communication device receives second information from a first communication device, the second information includes identification information corresponding to at least one candidate access network device respectively included in multiple candidate clusters, and the first communication device is an access network device included in a source cluster currently accessed by the second communication device; the second communication device sends first measurement report information to the first communication device, and the first measurement report information indicates the channel quality of at least one candidate access network device respectively included in the multiple candidate clusters. The first communication device can be a first access network device, or a chip or chip system in the first access network device, or a device used in conjunction with the first access network device; the second communication device can be a terminal device, or a chip or chip system in the terminal device, or a device used in conjunction with the terminal device.

[0027] The method provided in the third aspect is a method on the second communication device side corresponding to the first aspect, and its beneficial effects can be directly referred to the first aspect.

[0028] In certain implementations of the third aspect, the method further includes: the second communication device sending second measurement report information to the first communication device, where the second measurement report information indicates a channel quality of an access network device included in the source cluster.

[0029] In a fourth aspect, a communication method is provided, which can be performed by a second communication device. The method includes: the second communication device sends first measurement report information to the first communication device, where the first measurement report information indicates the channel quality of an access network device included in a source cluster currently accessed by the second communication device, and the first communication device is an access network device included in the source cluster. The first communication device can be a first access network device, or a chip or chip system in the first access network device, or a device used in conjunction with the first access network device; the second communication device can be a terminal device, or a chip or chip system in the terminal device, or a device used in conjunction with the terminal device.

[0030] The method provided in the fourth aspect is a method on the second communication device side corresponding to the first aspect, and its beneficial effects can be directly referred to the first aspect.

[0031] In certain implementations of the fourth aspect, the source cluster satisfies at least one of the following: the channel quality of at least one access network device included in the source cluster is greater than or equal to a first threshold; the throughput of the at least one access network device included in the source cluster is greater than or equal to a second threshold; or, the average communication rate of the at least one access network device included in the source cluster is greater than or equal to a third threshold.

[0032] In a fifth aspect, a communication method is provided, the method comprising: a first access network device obtains first information, the first information including identification information corresponding to at least one candidate access network device respectively included in multiple candidate clusters, the first access network device is an access network device included in a source cluster currently accessed by a terminal device; the first access network device obtains first measurement report information; the first access network device sends a switching request message, the switching request message is used to request that the terminal device be switched from the source cluster to a target cluster, the target cluster is determined based on the first information and the first measurement report information, and the target cluster is included in the multiple candidate clusters.

[0033] Based on the above technical solution, the first access network device in the source cluster to which the terminal device is currently connected can obtain identification information (first information) corresponding to at least one candidate access network device included in each of the multiple candidate clusters / list information of multiple candidate clusters; the first access network device determines to switch the terminal device from the source cluster to the target cluster based on the obtained first measurement report information and the first information; the first access network device initiates the switching process of switching the terminal device from the source cluster to the target cluster by sending a switching request message. Multiple access network devices within a cluster (source cluster / target cluster) can jointly serve the terminal device, and the terminal device only needs to switch between different clusters during the movement process. Therefore, the number of switching times of the terminal device can be reduced, thereby improving the communication experience of the terminal device.

[0034] In certain implementations of the fifth aspect, the first access network device obtains the first information, including: a first controller determines the first information; the first controller sends the first information to the first access network device; and the first access network device receives the first information from the first controller.

[0035] In certain implementations of the fifth aspect, the first controller determines the first information, including: the first controller determines the first information based on channel quality information of the plurality of candidate access network devices.

[0036] In certain implementations of the fifth aspect, the first measurement report information indicates a channel quality of at least one candidate access network device respectively included in the multiple candidate clusters.

[0037] In certain implementations of the fifth aspect, the method also includes: the first access network device sends second information to the terminal device, the second information including identification information corresponding to at least one candidate access network device included in the multiple candidate clusters; the first access network device obtains first measurement report information, including: the first access network device receives the first measurement report information from the terminal device.

[0038] In certain implementations of the fifth aspect, the method further includes: the first access network device obtains second measurement report information, where the second measurement report information indicates the channel quality of the access network devices included in the source cluster; the first access network device sends a first request message to the first controller based on the second measurement report information, where the first request message is used to obtain the first information; and the first controller receives the first request message from the first access network device.

[0039] In certain implementations of the fifth aspect, the first access network device obtains the second measurement report information, including: the first access network device receives the second measurement report information from the terminal device.

[0040] In certain implementations of the fifth aspect, the first information also includes priority information of the multiple candidate clusters, and the target cluster is a candidate cluster among the multiple candidate clusters whose priority is greater than or equal to a preset threshold; the first measurement report information indicates the channel quality of the access network device included in the source cluster.

[0041] In certain implementations of the fifth aspect, the first access network device sends a switching request message, including: the first access network device sends the switching request message to a second access network device, and the second access network device is a candidate access network device included in the target cluster.

[0042] In certain implementations of the fifth aspect, the first access network device sends a switching request message, including: the first access network device sends the switching request message to the first controller; the first controller receives the switching request message from the first access network device; the first controller sends a context establishment request message for the terminal device to the second controller; and the first controller receives a context establishment request confirmation message for the terminal device from the second controller.

[0043] In certain implementations of the fifth aspect, the method further includes: the first controller sends a second request message to the second controller, the second request message being used to obtain channel quality information of the multiple candidate access network devices; and the first controller receives the channel quality information of the multiple candidate access network devices from the second controller.

[0044] In certain implementations of the fifth aspect, the candidate cluster satisfies at least one of the following: the average frequency efficiency of the at least one candidate access network device included in the candidate cluster is greater than or equal to a first threshold; the average throughput of the at least one candidate access network device included in the candidate cluster is greater than or equal to a second threshold; or, the average communication rate of the at least one candidate access network device included in the candidate cluster is greater than or equal to a third threshold.

[0045] In certain implementations of the fifth aspect, the source cluster satisfies at least one of the following: the channel quality of at least one access network device included in the source cluster is greater than or equal to the first threshold; the throughput of the at least one access network device included in the source cluster is greater than or equal to the second threshold; or, the average communication rate of the at least one access network device included in the source cluster is greater than or equal to the third threshold.

[0046] In the sixth aspect, a communication device is provided, which can be applied to the first communication device described in the first aspect. The device includes: an acquisition unit, used to implement the acquisition function of the method described in the first aspect; and a transceiver unit, used to implement the receiving and sending functions of the method described in the first aspect.

[0047] In the seventh aspect, a communication device is provided, which can be applied to the third communication device described in the second aspect. The device includes: a processing unit, used to implement the processing functions such as determining the first information of the method described in the second aspect; and a transceiver unit, used to implement the receiving and sending functions of the method described in the second aspect.

[0048] In an eighth aspect, a communication device is provided, which can be applied to the second communication device described in the third aspect. The device includes: a transceiver unit, used to implement the receiving and sending functions of the method described in the third aspect.

[0049] In the ninth aspect, a communication device is provided, which can be applied to the second communication device described in the fourth aspect. The device includes: a transceiver unit, used to implement the sending function of the method described in the third aspect.

[0050] In the tenth aspect, a communication device is provided, comprising: a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the communication device executes the method in any possible implementation of the above-mentioned first to fourth aspects or the first to fourth aspects.

[0051] In the eleventh aspect, a communication device is provided, comprising: an input and output interface and a logic circuit, wherein the input and output interface is used to obtain input information and / or output information; the logic circuit is used to execute the method described in the first to fourth aspects or any possible implementation method of the first to fourth aspects above, and process and / or generate output information based on the input information.

[0052] In the twelfth aspect, a communication system is provided, including: a first communication device, a second communication device and a third communication device, the first communication device is used to implement the method in the above-mentioned first aspect or any possible implementation of the first aspect, the second communication device is used to implement the method in the above-mentioned third aspect and fourth aspect or any possible implementation of the third aspect and fourth aspect, and the third communication device is used to implement the method in the above-mentioned second aspect or any possible implementation of the second aspect.

[0053] In the thirteenth aspect, a communication system is provided, including: a first communication device and a third communication device, the first communication device is used to implement the method in the above-mentioned first aspect or any possible implementation of the first aspect, and the third communication device is used to implement the method in the above-mentioned second aspect or any possible implementation of the second aspect.

[0054] In the fourteenth aspect, a communication system is provided, including: a terminal device, a first access network device and a first controller, wherein the terminal device, the first access network device and the first controller are used to implement the method in the above-mentioned fifth aspect or any possible implementation method of the fifth aspect.

[0055] In the fifteenth aspect, a computer-readable storage medium is provided, which stores a computer program; when the computer program runs on a computer, the computer executes the method in the above-mentioned first to fourth aspects and any possible implementation of the first to fourth aspects.

[0056] In the sixteenth aspect, a computer program product comprising instructions is provided, wherein when the instructions are executed by a computer, the communication device implements the method in the above-mentioned first to fourth aspects and any possible implementation method of the first to fourth aspects.

[0057] The solutions provided in the sixth to sixteenth aspects are used to implement or cooperate with the methods provided in the first to fifth aspects, and therefore can achieve the same or corresponding beneficial effects as the first to fifth aspects, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] FIG1 is a schematic diagram of the architecture of a communication system used in an embodiment of the present application.

[0059] Figure 2 shows the basic process of switching terminal devices in an independent networking scenario.

[0060] FIG3 is a schematic diagram of the interaction process of traditional cell handover.

[0061] FIG4 is a schematic diagram showing the relationship among the controller, access network equipment and terminal equipment in an embodiment of the present application.

[0062] FIG5 is a schematic flowchart of a communication method according to an embodiment of the present application.

[0063] FIG6 is a schematic flow diagram of the communication method provided in an embodiment of the present application.

[0064] FIG7 is a schematic diagram of a terminal device movement scenario based on candidate clusters within the same controller.

[0065] FIG8 is a schematic diagram of multiple candidate clusters determined by the first controller.

[0066] FIG9 is another schematic flow diagram of the communication method provided in an embodiment of the present application.

[0067] FIG10 is another schematic flow diagram of the communication method provided in an embodiment of the present application.

[0068] FIG11 is a schematic diagram of terminal device movement scenarios based on candidate clusters in different controllers.

[0069] FIG12 is another schematic flow diagram of the communication method provided in an embodiment of the present application.

[0070] FIG13 is another schematic flow diagram of the communication method provided in an embodiment of the present application.

[0071] FIG14 is a schematic block diagram of a communication device according to an embodiment of the present application.

[0072] FIG15 is a schematic block diagram of another communication device according to an embodiment of the present application.

[0073] FIG16 is a schematic block diagram of another communication device according to an embodiment of the present application.

[0074] FIG17 is a schematic block diagram of another communication device according to an embodiment of the present application.

[0075] FIG18 is a schematic block diagram of another communication device according to an embodiment of the present application. DETAILED DESCRIPTION

[0076] The technical solution in this application will be described below with reference to the accompanying drawings.

[0077] The embodiments of the present application can be applied to various communication systems, such as wireless local area network systems (WLAN), narrowband Internet of Things systems (NB-IoT), long term evolution systems (LTE), and other fourth generation (4G) communication systems, satellite communications, sidelinks (SL), new radios (NR), and other fifth generation (5G) communication systems, and sixth generation (6G) communication systems evolved after 5G, etc.

[0078] The terminal device involved in the embodiments of the present application can be a device with wireless transceiver capabilities, and can specifically refer to a subscriber unit (SU), user equipment (UE), access terminal, cellular phone, user station, mobile station (MS), customer-premises equipment (CPE), remote station, remote terminal, mobile device, user terminal, wireless communication device, user agent, or user device. The terminal device can also be a satellite phone, cellular phone, smartphone, wireless data card, personal digital assistant (PDA), tablet computer, wireless modem (modulator demodulator, modem), laptop computer, machine type communication (MTC) device, and wireless terminal in self-driving. The terminal device may also be a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication capabilities, an in-vehicle device, a wearable device, a computing device or other processing device connected to a wireless modem, a communication device carried on a high-altitude aircraft, a drone, a robot, a smart point of sale (POS) machine, a terminal in device-to-device communication (D2D), a terminal in vehicle to everything (V2X), a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical care, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc. The user equipment includes a wireless terminal in a home or a terminal device in a future communication network, etc. The user equipment includes a vehicle user equipment.With the rise of the Internet of Things (IoT) technology, more and more devices that previously did not have communication capabilities, such as but not limited to household appliances, vehicles, tools and equipment, service equipment, and service facilities, have begun to obtain wireless communication capabilities by configuring wireless communication units, thereby being able to access wireless communication networks and accept remote control. Such devices have wireless communication capabilities because they are configured with wireless communication units, and therefore also fall into the category of wireless communication devices. This application does not limit this.

[0079] In the embodiments of the present application, the device for implementing the function of the terminal device can be the terminal device; it can also be a device that can support the terminal device to implement the function, such as a chip system. The device can be installed in the terminal device or used in conjunction with the terminal device. In the embodiments of the present application, the chip system can be composed of a chip or include a chip and other discrete devices.

[0080] Exemplarily, a network device is a device with wireless transceiver functions for communicating with a terminal device, and may also be a device for accessing a terminal device to a wireless network. The network device may be a node in a radio access network, which may also be referred to as a base station, or a radio access network (RAN) node (or device). The network device may be an evolved Node B (eNB or eNodeB) in LTE; or a next generation node B (gNB) in a 5G network or a base station in a future evolved public land mobile network (PLMN), a broadband network gateway (BNG), an aggregation switch, or a non-third generation partnership project (3GPP) access device, etc. Optionally, the network devices in the embodiments of the present application may include various forms of base stations, such as relay stations, access points, devices that implement base station functions in communication systems evolved after 5G, mobile switching centers, home evolved NodeBs (home Node Bs or home Node Bs, HNBs), baseband units (baseband units, BBUs), devices that perform base station functions in device to device (D2D), access points (APs) in wireless fidelity (WIFI) systems, wireless relay nodes, wireless backhaul nodes, transmission points (TPs) or transmission and reception points (TRPs), etc., devices that perform base station functions in vehicle-to-everything (V2X) and machine-to-machine (M2M) communications, etc., and may also include centralized units (CUs) and distributed units (DUs) in cloud radio access networks (C-RAN) systems, non-terrestrial communication networks (non-terrestrial networks), and wireless cellular networks. The network equipment in the NTN communication system can be deployed on high-altitude platforms or satellites.It can also be a gNB or transmission point in NR, one or a group (including multiple) of antenna panels of a base station in NR, or a network node constituting a gNB or transmission point, or a network device can also be a vehicle-mounted device, a wearable device, and a network device in a 6G network, or a network device in a future evolved PLMN network, or a network device deployed on a satellite, which is not limited in the embodiments of the present application. In addition, according to the size of the service coverage area provided, the base station can be divided into a macro base station for providing macro cells, a micro base station for providing micro cells, and a femto base station for providing femto cells. With the continuous evolution of wireless communication technology, future base stations may also adopt other names.

[0081] The product forms of network equipment are very rich. For example, during the product implementation process, the BBU can be integrated with the radio frequency unit (RFU) in the same device, which is connected to the antenna array via a cable (such as but not limited to a feeder). The BBU can also be set separately from the RFU, and the two are connected by optical fiber, and communicate through, for example, but not limited to, the common public radio interface (CPRI) protocol. In this case, the RFU is usually called a remote radio unit (RRU), which is connected to the antenna array via a cable. In addition, the RRU can also be integrated with the antenna array. For example, the active antenna unit (AAU) product adopts this structure.

[0082] Furthermore, the BBU can be further broken down into multiple components. For example, the BBU can be further divided into the CU and DU based on the real-time nature of the services it handles. The CU handles non-real-time protocols and services, while the DU handles physical layer protocols and real-time services. Furthermore, some physical layer functions can be separated from the BBU or DU and integrated into the AAU.

[0083] In another possible scenario, multiple network devices collaborate to assist the terminal in achieving wireless access, and different network devices respectively implement part of the functions of the base station. For example, the network device may be a CU, DU, CU-control plane (CP), CU-user plane (UP), or radio unit (RU), etc. The CU and DU may be set separately, or may be included in the same network element, such as a BBU. The RU may be included in a radio frequency device or a radio frequency unit, such as an RRU, AAU, or a remote radio head (RRH). It will be understood that the network device may be a CU node, a DU node, or a device including a CU node and a DU node. In addition, the CU may be divided into a network device in the access network RAN, or the CU may be divided into a network device in the core network (CN), without limitation here.

[0084] In different systems, CU (or CU-CP and CU-UP), DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in an open radio access network (open RAN, ORAN) system, CU may also be called O-CU (open CU), DU may also be called O-DU, CU-CP may also be called O-CU-CP, CU-UP may also be called O-CU-UP, and RU may also be called O-RU. For the convenience of description, this application uses CU, CU-CP, CU-UP, DU and RU as examples for description. Any unit of CU (or CU-CP, CU-UP), DU and RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0085] Network devices can communicate and interact with core network devices to provide communication services to terminal devices. Core network devices are, for example, devices in the 5G core network. As a bearer network, the core network provides an interface to the data network, providing communication connections, authentication, management, policy control, and data service delivery for terminals.

[0086] In the embodiments of the present application, the device for implementing the function of the network device can be the network device; or it can be a device that can support the network device to implement the function, such as a chip system. The device can be installed in the network device or used in conjunction with the network device.

[0087] Figure 1 is a schematic diagram of the architecture of a communication system 1000 used in an embodiment of the present application. As shown in Figure 1 , the communication system includes a radio access network 100 and a core network 200. Optionally, the communication system 1000 may also include the Internet 300. The radio access network 100 may include at least one radio access network device (such as 110a and 110b in Figure 1 ) and at least one terminal device (such as 120a-120j in Figure 1 ). The terminal device is wirelessly connected to the radio access network device, and the radio access network device is wirelessly or wiredly connected to the core network. The core network device and the radio access network device may be independent and distinct physical devices, or the functions of the core network device and the logical functions of the radio access network device may be integrated into the same physical device, or a single physical device may integrate some of the functions of the core network device and some of the functions of the radio access network device. Terminal devices and radio access network devices may be connected to each other via wired or wireless means. Figure 1 is only a schematic diagram, and the communication system may also include other network devices, such as wireless relay devices and wireless backhaul devices, which are not shown in Figure 1. In the embodiments of the present application, "wireless access network devices" may be referred to as "access network devices" for short.

[0088] The following is an explanation of some terminology concepts involved in the embodiments of this application.

[0089] Handover: refers to the process of a mobile terminal moving from the coverage area of ​​one base station to the coverage area of ​​another base station during a call.

[0090] To facilitate understanding of the embodiments of the present application, the following briefly introduces the technical solutions related to the embodiments of the present application.

[0091] Figure 2 shows the basic process of handover of a terminal device in an independent networking scenario. After the handover function is started and the judgment is passed, the access network device will select the corresponding processing mode based on the signal quality of the serving cell and related events. Depending on whether the signal quality of the candidate target cell needs to be measured before the terminal device switches, the processing mode is divided into measurement mode and blind mode. In the measurement mode, after the access network device sends the measurement control to the terminal device, the terminal device measures the signal quality of the candidate target cell and reports the measurement report to the access network device; the access network device makes a target cell or target frequency decision based on the measurement report and instructs the terminal device to perform the handover; if the terminal device fails to switch, a handover failure penalty is imposed, and the access network device selects another target cell and instructs the terminal device to perform the handover. In the blind mode, the terminal device does not need to measure the signal quality of the candidate target cell before switching. The access network device directly makes a target cell or target frequency decision and instructs the terminal device to perform the handover.

[0092] (1) Measurement mode: The access network device instructs the terminal device to measure and report the signal quality of candidate target cells based on the information sent by the measurement control. The access network device generates a target cell list based on the measurement report reported by the terminal device.

[0093] (2) Blind mode: The access network device does not instruct the terminal device to measure the signal quality of candidate target cells, but directly generates a list of target cells or target frequencies based on relevant priority parameters.

[0094] Blind mode is relatively widely used in high-frequency scenarios. Due to the high frequency and short wavelength of millimeter waves in high-frequency scenarios, signal transmission attenuation is rapid, resulting in limited coverage. In scenarios with rapid user mobility, using measurement mode may result in the terminal device moving out of the source cell before the signal quality of the target cell or frequency is fully measured, leading to increased call drop rates. In such cases, using blind mode allows the terminal device to quickly complete handover. However, blind mode scenarios require strict neighboring cell planning; incomplete neighboring cell planning may result in terminal device access failure.

[0095] Measurement control delivery refers to the process of the access network device delivering measurement configuration information to the terminal device. The following scenarios will trigger the access network device to deliver measurement configuration information to the terminal device: (1) When the terminal device enters the connected state, the access network device will deliver the measurement configuration information to the terminal device via a radio resource control (RRC) reconfiguration message; (2) When the terminal device is in the connected state or after handover, if the measurement configuration information is updated, the access network device will also deliver the updated measurement configuration information to the terminal device via an RRC reconfiguration message.

[0096] The measurement configuration information is configured by the access network equipment and sent to the terminal equipment. The measurement configuration information mainly includes the following information:

[0097] 1) Measurement object: This consists of attributes such as the measurement system, measurement frequency, or measurement cell. It indicates which cell or frequency the terminal device measures the signal quality of. The measurement cell can be a serving cell or a neighboring cell.

[0098] 2) Report configuration: It consists of measurement event information and triggering quantities for event reporting, etc.; it is used to instruct the terminal device under what conditions to report the measurement report and according to what standards to report the measurement report.

[0099] 3) Other configurations: Consists of properties such as the measurement synchronization signal and physical broadcast channel (PBCH) block (SSB) measurement timing configuration (SMTC), measurement gap, and measurement filter; used to indicate the duration and interval of measurement performed by the terminal device.

[0100] Figure 3 is a schematic diagram of the traditional cell handover process interaction. The specific steps are as follows.

[0101] 301. The source access network device sends an RRC reconfiguration message to the terminal device in the connected state. The RRC reconfiguration message is used by the terminal device to measure the signal strength of the currently served cell and other cells. The RRC reconfiguration message includes parameters such as measurement object, report configuration, and measurement identifier.

[0102] 302. The terminal device receives an RRC reconfiguration message from the source access network device. After performing cell measurement according to the RRC reconfiguration message, the terminal device generates a measurement report and reports it to the currently connected source access network device. The measurement report includes the signal strength of the current serving cell and the signal strength of other cells obtained by the terminal device.

[0103] 303. The source access network device determines whether the terminal device needs to perform cell switching based on the measurement report reported by the terminal device. If the source access network device determines that the terminal device needs to perform cell switching, it sends a switching request message to the target access network device.

[0104] 304. The target access network device receives the handover request message from the source access network device and decides whether to allow the terminal device to access based on the number of terminal devices connected to it and other conditions. If the terminal device is allowed to access, the target access network device sends a handover request confirmation message to the source access network device. The handover request confirmation message includes parameters such as the cell radio network temporary identifier (C-RNTI) allocated to the terminal device and the security-related algorithm of the target access network device.

[0105] 305. The source access network device receives a handover request confirmation message from the target access network device and sends a handover command to the terminal device. The handover command includes the parameters in the handover request confirmation message, which is equivalent to transparent transmission by the source access network device. Specifically, the handover command includes relevant information about the target cell and the relevant configuration parameters required for the terminal device to access the target cell. For example, the handover command includes information such as the PCI of the target cell, the frequency information of the target cell (the frequency of the target cell), the C-RNTI allocated by the target cell to the terminal device, and the random access channel (RACH) resources required to access the target cell.

[0106] 306. The terminal device receives the handover command from the source access network device, and initiates random access to the target access network device according to the handover command.

[0107] 307. If the terminal device successfully accesses the target access network device, the terminal device sends a switching completion message to the target access network device.

[0108] As mentioned above, the handover process involves a lot of signaling. In high-density network deployment scenarios such as 5G / beyond 5G (B5G) / 6G, due to the large number and density of access network devices, user mobility will cause frequent handovers. If the number of handovers for terminal devices is high, it will lead to increased handover failure rates, increased risk of service interruption, increased signaling overhead, and wasted bandwidth, resulting in a poor communication experience for the terminal device.

[0109] To address the frequent handoffs experienced by mobile users in high-density networks, the concept of clusters has been proposed. A cluster consists of multiple access network devices. With a well-designed cluster, all access network devices within the cluster can collectively serve end devices, reducing the frequency of user handoffs and improving the end-user experience through the collaborative services of all access network devices within the cluster.

[0110] An embodiment of the present application provides a communication method that can reduce the number of switching times of a terminal device, thereby improving the communication experience of the terminal device. Figure 4 is a schematic diagram of the relationship between the controller, access network device and terminal device of an embodiment of the present application. Figure 4 (a) is a schematic diagram of the same controller (first controller) having a communication connection (for example, a wired connection) with the access network devices included in the source cluster and the candidate cluster; Figure 4 (b) is a schematic diagram of the first controller having a communication connection with the access network devices included in the source cluster, and the second controller having a communication connection with the access network devices included in the candidate cluster. Among them, the cluster currently accessed by the terminal device is called the source cluster, the cluster to which the terminal device is to access through switching is called the candidate cluster, and the access network devices included in the candidate cluster can be called candidate access network devices.

[0111] FIG5 is a schematic flow chart of a communication method 500 according to an embodiment of the present application. The first communication device may be a first access network device, or a chip or chip system in the first access network device; the second communication device may be a terminal device, or a chip or chip system in the terminal device; the third communication device may be a first controller, or a chip or chip system in the first controller; the fourth communication device may be a second access network device, or a chip or chip system in the second access network device; the fifth communication device may be a second controller, or a chip or chip system in the second controller; the candidate access network device may be a candidate access network device, or a chip or chip system in the candidate access network device, etc.

[0112] The communication method of an embodiment of the present application is described by taking as an example a first communication device being a first access network device, a second communication device being a terminal device, a third communication device being a first controller, a fourth communication device being a second access network device, and a fifth communication device being a second controller. The first access network device and the second access network device may be base stations; the first access network device may be understood as the head base station of a source cluster, and the second access network device may be understood as the head base station of a target cluster.

[0113] 510. A first access network device obtains first information, where the first information includes identification information corresponding to at least one candidate access network device included in each of a plurality of candidate clusters. The first access network device is an access network device included in a source cluster currently accessed by a terminal device.

[0114] In a possible implementation, the first information may be list information of multiple candidate clusters.

[0115] The candidate access network device is an access network device outside the source cluster whose distance to the terminal device is less than or equal to a fourth threshold; the source cluster includes one or more access network devices. The fourth threshold may be predefined.

[0116] In one possible implementation, the identification information corresponding to the candidate access network device includes the physical cell identifier (PCI) of the candidate access network device, or the cell-radio network temporary identifier (CRNTI), or the new radio cell identifier (NR cell identifier, NCI), or other newly defined identifiers.

[0117] Optionally, the first controller determines the first information; the first controller sends the first information to the first access network device, and correspondingly, the first access network device receives the first information from the first controller. The first controller can be a network element in a radio access network (RAN) or a network element in a core network.

[0118] Exemplarily, the first controller collects channel quality information of different candidate access network devices, and determines first information / multiple candidate clusters according to the channel quality information of the multiple candidate access network devices.

[0119] The first controller can make a rapid performance evaluation of different clustering combinations of multiple candidate access network devices, and determine the clustering combination with better performance as the candidate cluster, and the performance of the source cluster and the candidate cluster both meet certain conditions. Exemplarily, the candidate cluster meets at least one of the following: the average frequency efficiency of at least one candidate access network device included in the candidate cluster is greater than or equal to the first threshold; the average throughput of at least one candidate access network device included in the candidate cluster is greater than or equal to the second threshold; the average communication rate of at least one candidate access network device included in the candidate cluster is greater than or equal to the third threshold. The first threshold, the second threshold, and the third threshold can be determined or predefined by the first controller. The performance of the candidate cluster meets certain conditions, which can improve the communication experience of the terminal device accessing the candidate cluster.

[0120] Exemplarily, the source cluster satisfies at least one of the following conditions: the channel quality of at least one access network device included in the source cluster is greater than or equal to a first threshold; the throughput of at least one access network device included in the source cluster is greater than or equal to a second threshold; and the average communication rate of at least one access network device included in the source cluster is greater than or equal to a third threshold. If the performance of the source cluster meets certain conditions, the communication experience of terminal devices accessing the source cluster can be improved.

[0121] 520. The first access network device obtains first measurement report information. The first measurement report information may be determined by the first access network device by measuring an uplink reference signal sent by the terminal device; or the first measurement report information may be determined by the terminal device by measuring a downlink reference signal sent by the first access network device and sent to the first access network device.

[0122] At step 530 , the first access network device sends a handover request message, where the handover request message is used to request handover of the terminal device from the source cluster to a target cluster. The target cluster is determined by the terminal device based on the first information and the first measurement report information, and the target cluster is included in multiple candidate clusters. The target cluster includes one or more candidate access network devices.

[0123] In one possible implementation, a first access network device sends a handover request message to a second access network device, where the second access network device is a candidate access network device included in the target cluster. Correspondingly, the second access network device receives the handover request message from the first access network device. The second access network device sends a handover request confirmation message to the first access network device. After the first access network device receives the handover request confirmation message from the second access network device, the first access network device sends a handover command to a terminal device. The terminal device switches from the source cluster to the target cluster based on the received handover command. In this case, the first controller is connected to the access network devices included in the source cluster and the candidate access network devices included in the multiple candidate clusters via a wired connection.

[0124] In one possible implementation, the first information further indicates identification information corresponding to the highest-priority candidate access network device among the at least one candidate access network device included in the candidate cluster. It can be assumed that the highest-priority candidate access network device among the at least one candidate access network device included in each candidate cluster has the best channel quality information and can provide better communication services. The second access network device is the highest-priority candidate access network device among the at least one candidate access network device included in the target cluster; the first access network device is the highest-priority access network device among the access network devices included in the source cluster.

[0125] In one possible implementation, a first access network device sends a handover request message to a first controller; correspondingly, the first controller receives the handover request message from the first access network device. The first controller sends a context establishment request message for a terminal device to a second controller; after receiving the context establishment request message from the first controller, the second controller sends a context establishment request confirmation message for the terminal device to the first controller; correspondingly, the first controller receives the context establishment request confirmation message from the second controller. In this case, the first controller is connected to the access network devices included in the source cluster via a wired connection, and the second controller is connected to the candidate access network devices included in multiple candidate clusters via a wired connection.

[0126] The first controller and the second controller may be connected via an interface. When the first controller and the second controller are network elements in the RAN, the first controller and the second controller may be connected via an Xn interface; when the first controller and the second controller are network elements in the core network, the first controller and the second controller may be connected via an Ng interface.

[0127] In the technical solution provided in the embodiment of the present application, the first access network device in the source cluster to which the terminal device is currently connected can obtain identification information (first information) corresponding to at least one candidate access network device included in each of the multiple candidate clusters / list information of multiple candidate clusters; the first access network device determines to switch the terminal device from the source cluster to the target cluster based on the obtained first measurement report information and the first information; the first access network device initiates a switching process to switch the terminal device from the source cluster to the target cluster by sending a switching request message. Multiple access network devices within a cluster (source cluster / target cluster) can serve the terminal device together. During the movement, the terminal device only needs to switch between different clusters and does not need to switch within the cluster. Therefore, the number of switching times of the terminal device can be reduced, thereby improving the communication experience of the terminal device.

[0128] Depending on whether channel quality measurement of at least one candidate access network device in each of the candidate clusters is required before switching, the processing mode is divided into measurement mode and blind mode. In measurement mode, channel quality measurement of at least one candidate access network device in each of the candidate clusters is required; in blind mode, channel quality measurement of the candidate access network devices in the candidate clusters is not required. The first implementation method below corresponds to the measurement mode, and the second implementation method corresponds to the blind mode.

[0129] In a first implementation, the first measurement report information indicates the channel quality of at least one candidate access network device included in each of the multiple candidate clusters. Exemplarily, the target cluster is the candidate cluster with the best channel quality among the multiple candidate clusters.

[0130] Optionally, the first access network device sends second information to the terminal device, where the second information includes identification information corresponding to at least one candidate access network device included in each of the multiple candidate clusters. Accordingly, the terminal device receives the second information from the first access network device. Based on the second information, the terminal device measures the channel quality of the at least one candidate access network device included in each of the multiple candidate clusters. The terminal device sends first measurement report information to the first access network device. Accordingly, the first access network device receives the first measurement report information from the terminal device.

[0131] Optionally, the first information obtained by the first access network device also includes priority information of multiple candidate clusters, and the second information sent by the first access network device to the terminal device also includes priority information of multiple candidate clusters; after receiving the second information from the first access network device, the terminal device measures, based on the second information, the channel quality of at least one candidate access network device respectively included in one or more candidate clusters having a priority higher than a fifth threshold, and the first measurement report information sent by the terminal device to the first access network device indicates the channel quality of at least one candidate access network device respectively included in one or more candidate clusters having a priority higher than the fifth threshold. The fifth threshold may be predefined or determined by the terminal device.

[0132] Optionally, before the first access network device receives the first information from the first controller, the first access network device obtains second measurement report information, where the second measurement report information indicates the channel quality of the access network devices included in the source cluster; the first access network device sends a first request message to the first controller based on the second measurement report information, where the first request message is used to obtain the first information. Correspondingly, the first controller receives the first request message from the first access network device, determines the first information based on the first request message, and sends the first information to the first access network device. The second measurement report information can be determined by the first access network device by measuring the uplink reference signal sent by the terminal device; the second measurement report information can also be determined by the terminal device by measuring the downlink reference signal sent by the first access network device and sent to the first access network device.

[0133] Optionally, after receiving the first request message from the first controller, the first controller sends a second request message to the second controller, where the second request message is used to obtain channel quality information of multiple candidate access network devices. Correspondingly, the second controller receives the second request message from the first controller; the second controller sends the channel quality information of multiple candidate access network devices to the first controller; and correspondingly, the first controller receives the channel quality information of multiple candidate access network devices from the second controller. In this case, the first controller is connected to the access network devices included in the source cluster, and the second controller is connected to the candidate access network devices included in multiple candidate clusters.

[0134] It should be understood that when the first controller is connected to the access network devices included in the source cluster and the candidate access network devices included in multiple candidate clusters, the first controller does not need to send a second request message to the second controller for obtaining the channel quality information of multiple candidate access network devices. The first controller can determine the channel quality information of multiple candidate access network devices by itself.

[0135] Optionally, before the first access network device sends the first request message to the first controller, the terminal device sends second measurement report information to the first access network device, where the second measurement report information indicates the channel quality of the access network devices included in the source cluster; correspondingly, the first access network device receives the second measurement report information from the terminal device, and the first access network device determines that switching is required based on the second measurement report information.

[0136] In a first implementation, the first access network device in the source cluster to which the terminal device is currently connected can obtain identification information (first information) corresponding to at least one candidate access network device respectively included in multiple candidate clusters / list information of multiple candidate clusters; the first access network device obtains first measurement report information based on the first information, and the first measurement report information indicates the channel quality of at least one candidate access network device respectively included in the multiple candidate clusters; the first access network device determines to switch the terminal device from the source cluster to the target cluster based on the first measurement report information, and initiates a switching process for switching the terminal device from the source cluster to the target cluster by sending a switching request message. Multiple access network devices within a cluster (source cluster / target cluster) can serve the terminal device together, and the terminal device only needs to switch between different clusters during movement. Therefore, the number of switching times of the terminal device can be reduced, thereby improving the communication experience of the terminal device.

[0137] In this implementation, the first access network device needs to obtain the channel quality of at least one candidate access network device respectively included in the multiple candidate clusters included in the first information based on the identification information corresponding to at least one candidate access network device respectively included in the multiple candidate clusters; the first access network device determines the target cluster from the multiple candidate clusters based on the channel quality of at least one candidate access network device respectively included in the multiple candidate clusters.

[0138] In a second implementation, the first information also includes priority information for multiple candidate clusters. The target cluster is a candidate cluster with a priority greater than or equal to a preset threshold among the multiple candidate clusters. The first measurement report information indicates the channel quality of the access network devices included in the source cluster. Candidate clusters with higher priorities have better performance. Exemplarily, the target cluster is the candidate cluster with the highest priority among the multiple candidate clusters.

[0139] Exemplarily, the first access network device determines that handover is required based on the channel quality of the access network device included in the source cluster indicated by the first measurement report information. The first access network device then determines a target cluster from the multiple candidate clusters based on the priority information of the multiple candidate clusters included in the first information. If the priority of the determined target cluster is greater than or equal to a preset threshold, it indicates that the target cluster has good performance, thereby improving the communication experience of terminal devices accessing the target cluster.

[0140] In the second implementation, the first access network device in the source cluster to which the terminal device is currently connected can obtain identification information (first information) corresponding to at least one candidate access network device included in each of the multiple candidate clusters / list information of multiple candidate clusters; multiple access network devices in the source cluster jointly serve the terminal device, and when the terminal device is about to move out of the source cluster, the channel quality information of the access network devices included in the source cluster deteriorates, and the terminal device can send a first measurement report information to the first access network device, and the first measurement report information indicates the channel quality of the access network devices included in the source cluster; the first access network device determines to switch the terminal device from the source cluster to the target cluster based on the first information and the first measurement report information, and initiates the switching process of switching the terminal device from the source cluster to the target cluster by sending a switching request message. Multiple access network devices in a cluster (source cluster / target cluster) can jointly serve the terminal device, and the terminal device only needs to switch between different clusters during the movement process. Therefore, the number of switching times of the terminal device can be reduced, thereby improving the communication experience of the terminal device.

[0141] In this implementation, the first access network device does not need to obtain the channel quality of at least one candidate access network device included in multiple candidate clusters, but only needs to obtain the channel quality of the access network device included in the source cluster, and determine to switch the terminal device from the source cluster to the target cluster based on the channel quality of the access network device included in the source cluster and the first information.

[0142] Optionally, after the first controller determines the first information, the first controller does not send the first information to the first access network device. The first access network device sends the obtained first measurement report information to the first controller, and the first controller makes a switching decision to switch the terminal device from the source cluster to the target cluster based on the first information and the first measurement report information.

[0143] When the first controller is connected to the access network devices included in the source cluster and the candidate access network devices included in multiple candidate clusters, after the first controller makes a switching decision to switch the terminal device from the source cluster to the target cluster, the first controller can notify the first access network device included in the source cluster to initiate a switching request to the second access network device included in the target cluster; or, the first controller can notify the second access network device to switch the terminal device from the source cluster to the target cluster, and the first controller initiates the switching request. For example, after the first controller makes a switching decision to switch the terminal device from the source cluster to the target cluster, the first controller sends a switching request message to the second access network device; the second access network device receives the switching request message from the second controller and allows the terminal device to be switched from the source cluster to the target cluster; the second access network device sends a switching request confirmation message to the second access network device, and correspondingly, the first controller receives the switching request confirmation message from the second access network device; the second access network device sends a switching command to the terminal device.

[0144] When the first controller is connected to the access network device included in the source cluster and the second controller is connected to the candidate access network devices included in multiple candidate clusters, after the first controller makes a switching decision to switch the terminal device from the source cluster to the target cluster, the first controller sends a switching notification message to the second controller; after the second controller receives the switching notification message from the first controller, the second controller sends a switching request message to the second access network device; after the second access network device receives the switching request message from the second controller, the second access network device sends a switching request confirmation message to the second controller; after the second controller receives the switching request confirmation message, it sends a switching notification confirmation message to the first controller; after the first controller receives the switching notification confirmation message from the second controller, the first controller sends a switching command to the first access network device; after the first access network device receives the switching command from the first controller, it sends a switching command to the terminal device.

[0145] To facilitate understanding, the communication method provided in the embodiments of the present application will be introduced below with reference to specific examples.

[0146] FIG6 is a schematic flow diagram of the communication method provided in an embodiment of the present application. In this example, the first access network device needs to obtain the channel quality of at least one candidate access network device included in each of the multiple candidate clusters, which can be understood as the above-mentioned measurement mode; and the first controller is connected to the access network device included in the source cluster and the candidate access network devices included in the multiple candidate clusters via a wired connection, and the first controller can communicate directly with the access network device included in the source cluster and the candidate access network devices included in the multiple candidate clusters. The specific process is as follows.

[0147] 601. A terminal device sends second measurement report information to a first access network device, where the second measurement report information indicates channel quality of the access network device included in the source cluster. The first access network device is the access network device included in the source cluster to which the terminal device is currently accessing.

[0148] 602. The first access network device receives second measurement report information from the terminal device. The first access network device determines to initiate a handover decision based on the second measurement report information. Exemplarily, when the first access network device determines, based on the second measurement report information, that the channel quality of the access network devices included in the source cluster is below a certain threshold, the first access network device determines to initiate a handover decision.

[0149] 603. The first access network device sends a first request message to the first controller. The first request message is used to obtain first information, where the first information includes identification information corresponding to at least one candidate access network device included in each of the multiple candidate clusters. In one possible implementation, the first request message is used to obtain list information of the multiple candidate clusters.

[0150] At 604, the first controller receives a first request message from the first access network device and determines first information. Exemplarily, the first controller determines the first information based on channel quality information of multiple candidate access network devices. In one possible implementation, the first controller determines multiple candidate clusters based on the channel quality information of the multiple candidate access network devices.

[0151] For example, Figure 7 is a schematic diagram of a terminal device movement scenario based on candidate clusters within the same controller, and Figure 8 is a schematic diagram of multiple candidate clusters determined by the first controller, wherein the performance of both the source cluster and the candidate clusters meet certain conditions.

[0152] 605. The first controller sends first information to the first access network device.

[0153] 606 , the first access network device receives the first information from the first controller, and sends second information to the terminal device, where the second information includes identification information corresponding to at least one candidate access network device included in each of the multiple candidate clusters.

[0154] 607. The terminal device receives second information from the first access network device. The terminal device determines the channel quality of at least one candidate access network device included in each of the multiple candidate clusters by measuring a downlink reference signal based on the second information.

[0155] 608. The terminal device sends first measurement report information to the first access network device, where the first measurement report information indicates a channel quality of at least one candidate access network device included in each of the multiple candidate clusters.

[0156] 609. The first access network device receives first measurement report information from the terminal device; the first access network device determines to switch the terminal device from the source cluster to the target cluster based on the first measurement report information, wherein the multiple candidate clusters include the target cluster.

[0157] Exemplarily, the first access network device selects a candidate cluster including at least one candidate access network device with the highest average channel quality from multiple candidate clusters as the target cluster based on the first measurement report information, and determines to switch the terminal device from the source cluster to the target cluster.

[0158] At step 610, the first access network device sends a handover request message to the second access network device. The handover request message includes identification information corresponding to at least one candidate access network device included in the target cluster. The handover request message is used to request handover of the terminal device from the source cluster to the target cluster. The second access network device is a candidate access network device included in the target cluster. In one possible implementation, because the first controller is connected to the access network devices included in the source cluster and the candidate access network devices included in multiple candidate clusters, the first access network device and the second access network device are connected via an Xn interface.

[0159] Exemplarily, the first information further indicates identification information corresponding to the candidate access network device with the highest priority among at least one candidate access network device included in the candidate cluster. The second access network device may be the candidate access network device with the highest priority among the candidate access network devices included in the target cluster.

[0160] 611. The second access network device receives the handover request message from the first access network device and allows the terminal device to be handed over from the source cluster to the target cluster. Exemplarily, after receiving the handover request message from the first access network device, the second access network device allows the terminal device to be handed over from the source cluster to the target cluster if it determines that the candidate access network devices included in the target cluster have a low load and available time-frequency resources.

[0161] 612. The second access network device sends a switching request confirmation message to the first access network device. The switching request confirmation message indicates that the terminal device is allowed to switch from the source cluster to the target cluster. The switching request confirmation message includes the identification information of the terminal device allocated by the second access network device to the terminal device, such as C-RNTI.

[0162] Optionally, after the second access network device receives the switching request message from the first access network device, if the terminal device is not allowed to access the target cluster, the second access network device sends a switching preparation failure message to the first access network device, and the switching preparation failure message indicates that the terminal device is not allowed to switch from the source cluster to the target cluster.

[0163] 613. After the first access network device receives the switching request confirmation message from the second access network device, the first access network device sends a switching command to the terminal device. The switching command includes the identification information of the terminal device allocated by the second access network device to the terminal device, such as C-RNTI.

[0164] At 614, the first access network device sends a first message to the second access network device. The first message is used to inform the second access network device which data packets are received and which data packets are not received. For example, the first message is used to inform the second access network device which packet data convergence protocol (PDCP) service data unit (SDU) data packets are received and which data packets are not received. Exemplarily, the first message is a sequence number (SN) state transition message.

[0165] In step 615, after receiving the handover command from the first access network device, the terminal device attempts to establish a connection with the second access network device. If the terminal device successfully connects to the second access network device, the terminal device sends a handover complete message to the second access network device and disconnects from the first access network device. Correspondingly, the second access network device receives the handover complete message from the terminal device. Step 615 can be performed before step 614, or simultaneously with step 614, without limitation.

[0166] 616. The second access network device sends a path switching request message to the first controller. The path switching request message is used to request to change the forwarding address of the downlink data so that the core network subsequently sends the downlink data of the terminal device to the second access network device instead of the first access network device.

[0167] 617. After receiving the path switch request message, the first controller notifies relevant network elements (e.g., user plane function (UPF) or other core network elements) to perform path switching. If the path switching is successful, the first controller sends a path switch request confirmation message to the second access network device.

[0168] 618. The second access network device sends a notification message of releasing the context of the terminal device to the first access network device, so that the first access network device releases the context of the terminal device. For example, the first controller may be an access and mobility management function (AMF).

[0169] FIG9 is another schematic flow diagram of the communication method provided in an embodiment of the present application. In this example, the first access network device needs to obtain the channel quality of at least one candidate access network device included in each of the multiple candidate clusters, which can be understood as the above-mentioned measurement mode; and the first controller is connected to the access network device included in the source cluster and the candidate access network devices included in the multiple candidate clusters via a wired connection, and the first controller can communicate directly with the access network device included in the source cluster and the candidate access network devices included in the multiple candidate clusters. The specific process is as follows.

[0170] 901. The terminal device sends third measurement report information to the first access network device. The third measurement report information indicates the channel quality of the access network devices included in the source cluster and the channel quality of the access network devices corresponding to multiple neighboring areas. The neighboring areas include cells adjacent to the cell currently accessed by the terminal device. The first access network device is the access network device included in the source cluster currently accessed by the terminal device.

[0171] 902: A first access network device receives third measurement report information from a terminal device. The first access network device determines to initiate a handover decision based on the third measurement report information. Exemplarily, when the first access network device determines, based on the third measurement report information, that the channel quality of the access network devices included in the source cluster is below a certain threshold, the first access network device determines to initiate a handover decision.

[0172] 903. The first access network device sends third information to the first controller. The third information indicates the channel qualities of the access network devices corresponding to the plurality of neighboring cells and instructs the first controller to make a handover decision. Correspondingly, the first controller receives the third information from the first access network device.

[0173] At 904, the first controller receives third information from the first access network device and determines first information, where the first information includes identification information corresponding to at least one candidate access network device included in each of the multiple candidate clusters, where the access network devices corresponding to the multiple neighboring cells include multiple candidate access network devices. Exemplarily, the first controller determines the first information based on channel quality information of the multiple candidate access network devices.

[0174] At 905, the first controller determines, based on the first information, to switch the terminal device from a source cluster to a target cluster, where the target cluster is included in the plurality of candidate clusters. Exemplarily, the first controller selects, from the plurality of candidate clusters, a candidate cluster that includes at least one candidate access network device with the highest average channel quality as the target cluster, and determines to switch the terminal device from the source cluster to the target cluster.

[0175] 906. The first controller sends a switching notification message to the first access network device. The switching notification message is used to notify the first access network device to initiate a switching request to the second access network device included in the target cluster. The switching notification message includes identification information corresponding to at least one candidate access network device included in the target cluster and identification information of the second access network device.

[0176] Optionally, the first controller may also notify the second access network device to switch the terminal device from the source cluster to the target cluster, and the first controller may initiate a switching request.

[0177] 907. Correspondingly, the first access network device receives a handover notification message from the first controller. Based on the handover notification message, the first access network device sends a handover request message to the second access network device. The handover request message includes identification information corresponding to at least one candidate access network device included in the target cluster. The handover request message is used to request that the terminal device be switched from the source cluster to the target cluster. In one possible implementation, since the first controller is connected to the access network devices included in the source cluster and the candidate access network devices included in multiple candidate clusters, the first access network device and the second access network device are connected via an Xn interface.

[0178] The subsequent steps are the same as steps 611 to 618 in FIG. 6 , and reference may be made to FIG. 6 , and detailed description thereof will not be given here.

[0179] Figure 10 is another schematic flow diagram of the communication method provided in an embodiment of the present application. In this example, the first access network device needs to obtain the channel quality of at least one candidate access network device included in multiple candidate clusters, which can be understood as the above-mentioned measurement mode; and the first controller is connected to the access network device included in the source cluster via a wired connection, and the second controller is connected to the candidate access network devices included in the multiple candidate clusters via a wired connection. The first controller can communicate directly with the access network device included in the source cluster, and the second controller can communicate directly with the candidate access network devices included in the multiple candidate clusters. The specific process is as follows.

[0180] 1001. A terminal device sends second measurement report information to a first access network device, where the second measurement report information indicates channel quality of the access network device included in the source cluster. The first access network device is the access network device included in the source cluster currently accessed by the terminal device.

[0181] 1002. A first access network device receives second measurement report information from a terminal device. The first access network device determines to initiate a handover decision based on the second measurement report information. Exemplarily, when the first access network device determines, based on the second measurement report information, that a channel quality of an access network device included in the source cluster is below a certain threshold, the first access network device determines to initiate a handover decision.

[0182] 1003. The first access network device sends a first request message to the first controller. The first request message is used to obtain first information, where the first information includes identification information corresponding to at least one candidate access network device included in each of the multiple candidate clusters. In one possible implementation, the first request message is used to obtain list information of the multiple candidate clusters.

[0183] 1004. The first controller receives a first request message from the first access network device. The first controller sends a second request message to the second controller based on the first request message, where the second request message is used to obtain channel quality information of multiple candidate access network devices.

[0184] For example, Figure 11 is a schematic diagram of a terminal device mobility scenario based on candidate clusters within different controllers. The source cluster controller is the first controller, and the candidate cluster 1 controller and the candidate cluster 2 controller are the second controllers. The performance of both the source cluster and the candidate clusters meets certain conditions.

[0185] The first controller and the second controller may be connected via an interface. When the first controller and the second controller are network elements in the RAN, the first controller and the second controller may be connected via an Xn interface; when the first controller and the second controller are network elements in the core network, the first controller and the second controller may be connected via an Ng interface.

[0186] 1005 : After receiving the second request message from the first controller, the second controller sends channel quality information of multiple candidate access network devices to the first controller.

[0187] 1006. The first controller receives channel quality information of multiple candidate access network devices from the second controller. The first controller determines first information based on the channel quality information of the multiple candidate access network devices. In one possible implementation, the first controller determines multiple candidate clusters based on the channel quality information of the multiple candidate access network devices.

[0188] 1007. The first controller sends first information to the first access network device.

[0189] 1008. The first access network device receives the first information from the first controller and sends second information to the terminal device, where the second information includes identification information corresponding to at least one candidate access network device included in each of the multiple candidate clusters.

[0190] 1009. The terminal device receives second information from the first access network device. The terminal device determines, based on the second information, a channel quality of at least one candidate access network device included in each of the multiple candidate clusters by measuring a downlink reference signal.

[0191] 1010. The terminal device sends first measurement report information to a first access network device, where the first measurement report information indicates a channel quality of at least one candidate access network device included in each of a plurality of candidate clusters.

[0192] 1011. A first access network device receives first measurement report information from a terminal device, and the first access network device determines, based on the first measurement report information, to switch the terminal device from a source cluster to a target cluster, where the target cluster is included in the plurality of candidate clusters.

[0193] Exemplarily, the first access network device selects a candidate cluster including at least one candidate access network device with the highest average channel quality from multiple candidate clusters as the target cluster based on the first measurement report information, and determines to switch the terminal device from the source cluster to the target cluster.

[0194] 1012. The first access network device sends a switching request message to the first controller. The switching request message includes identification information corresponding to at least one candidate access network device included in the target cluster. The switching request message is used to request switching of the terminal device from the source cluster to the target cluster.

[0195] 1013. The first controller receives a switching request message from the first access network device; the first controller sends a context establishment request message of the terminal device to the second controller, where the context establishment request message of the terminal device is used to request that the terminal device be switched from the source cluster to the target cluster, and the context establishment request message of the terminal device includes identification information corresponding to at least one candidate access network device included in the target cluster.

[0196] At 1014, the second controller receives a context establishment request message from the terminal device of the first controller and allows the terminal device to be switched from the source cluster to the target cluster. For example, after receiving the context establishment request message from the terminal device of the first controller, if the second controller determines that the target cluster includes candidate access network devices with low load and available time-frequency resources, the second controller allows the terminal device to be switched from the source cluster to the target cluster.

[0197] 1015. The second controller sends a switching notification message to the second access network device, where the switching notification message is used to notify the second access network device to switch the terminal device from the source cluster to the target cluster. The second access network device is a candidate access network device included in the target cluster.

[0198] 1016. After receiving the handover notification message from the second controller, the second access network device sends a handover notification confirmation message to the second controller. The handover notification confirmation message includes the C-RNTI allocated by the second access network device to the terminal device.

[0199] 1017. The second controller sends a context establishment request confirmation message of the terminal device to the first controller; correspondingly, the first controller receives the context establishment request confirmation message of the terminal device from the second controller, and the context establishment request confirmation message of the terminal device includes the C-RNTI allocated by the second access network device to the terminal device.

[0200] 1018. The first controller sends a switching request confirmation message to the first access network device. The switching request confirmation message indicates that the terminal device is allowed to be switched from the source cluster to the target cluster. The switching request confirmation message includes the C-RNTI allocated by the second access network device to the terminal device.

[0201] 1019. After the first access network device receives the handover request confirmation message from the first controller, the first access network device sends a handover command to the terminal device. The handover command includes the C-RNTI allocated by the second access network device to the terminal device.

[0202] 1020. The first access network device sends a first message to the second access network device, where the first message is used to inform the second access network device which PDCP SDU data packets are received and which are not received. Exemplarily, the first message is an SN state transfer message.

[0203] At 1021, after receiving the handover command from the first access network device, the terminal device attempts to establish a connection with the second access network device. If the terminal device successfully connects to the second access network device, it sends a handover completion message to the second access network device and disconnects from the first access network device. Step 1021 can be performed before step 1020, or can be performed simultaneously with step 1020. This is not limited to this.

[0204] 1022. The second access network device sends a path switching request message to the second controller. The path switching request message is used to request to change the forwarding address of the downlink data so that the core network subsequently sends the downlink data of the terminal device to the second access network device instead of the first access network device.

[0205] 1023. After receiving the path switch request message, the second controller notifies the user plane unit or other core network elements to perform path switch. If the path switch is successful, the second controller replies with a path switch request confirmation message to the second access network device.

[0206] 1024. The second access network device sends a context notification message for releasing the terminal device to the second controller, so that the first access network device releases the context of the terminal device; the second controller forwards the context notification message for releasing the terminal device to the first controller, and the first controller sends the context notification message for releasing the terminal device to the first access network device.

[0207] Optionally, the first controller does not send the first information to the first access network device; the first access network device sends the third measurement report information reported by the terminal device to the first controller, and the first controller makes a switching decision to switch the terminal device from the source cluster to the target cluster based on the first information and the third measurement report information.

[0208] Figure 12 is another schematic flow diagram of the communication method provided in an embodiment of the present application. In this example, the first access network device does not need to obtain the channel quality of at least one candidate access network device included in each of the multiple candidate clusters, which can be understood as the above-mentioned blind mode; and the first controller is connected to the access network device included in the source cluster and the candidate access network devices included in the multiple candidate clusters via a wired connection, and the first controller can communicate directly with the access network device included in the source cluster and the candidate access network devices included in the multiple candidate clusters. The specific process is as follows.

[0209] At 1201, a first controller determines first information, where the first information includes identification information corresponding to at least one candidate access network device included in each of the multiple candidate clusters and priority information of the multiple candidate clusters. Exemplarily, the first controller determines the first information based on channel quality information of the multiple candidate access network devices. The performance of both the source cluster and the candidate clusters meets certain conditions.

[0210] 1202. The first controller sends first information to a first access network device. Correspondingly, the first access network device receives the first information from the first controller. The first access network device is an access network device included in the source cluster currently accessed by the terminal device.

[0211] 1203. The terminal device sends first measurement report information to the first access network device, where the first measurement report information indicates the channel quality of the access network device included in the source cluster.

[0212] At 1204, the first access network device receives first measurement report information from the terminal device. Based on the first measurement report information and the first information, the first access network device determines to switch the terminal device from the source cluster to the target cluster. The target cluster is a candidate cluster among the multiple candidate clusters whose priority is greater than or equal to a preset threshold. Exemplarily, the target cluster is the candidate cluster with the highest priority among the multiple candidate clusters; alternatively, the target cluster is a candidate cluster randomly selected from the multiple candidate clusters whose priorities are greater than or equal to the preset threshold.

[0213] At 1205, the first access network device sends a handover request message to the second access network device. The handover request message includes identification information corresponding to at least one candidate access network device included in the target cluster. The handover request message is used to request handover of the terminal device from the source cluster to the target cluster. The second access network device is a candidate access network device included in the target cluster. In one possible implementation, because the first controller is connected to the access network devices included in the source cluster and the candidate access network devices included in multiple candidate clusters, the first access network device and the second access network device are connected via an Xn interface.

[0214] Exemplarily, the first information further indicates identification information corresponding to the candidate access network device with the highest priority among at least one candidate access network device included in the candidate cluster. The second access network device may be the candidate access network device with the highest priority among the candidate access network devices included in the target cluster.

[0215] At 1206, the second access network device receives the handover request message from the first access network device and allows handover of the terminal device from the source cluster to the target cluster. For example, after receiving the handover request message from the first access network device, the second access network device allows handover of the terminal device from the source cluster to the target cluster if it determines that the candidate access network devices included in the target cluster have a low load and available time-frequency resources.

[0216] 1207. The second access network device sends a switching request confirmation message to the first access network device. The switching request confirmation message indicates that the terminal device is allowed to switch from the source cluster to the target cluster. The switching request confirmation message includes the C-RNTI allocated by the second access network device to the terminal device.

[0217] Optionally, after the second access network device receives the switching request message from the first access network device, if the terminal device is not allowed to access the target cluster, the second access network device sends a switching preparation failure message to the first access network device, and the switching preparation failure message indicates that the terminal device is not allowed to switch from the source cluster to the target cluster.

[0218] 1208. After the first access network device receives the handover request confirmation message from the second access network device, the first access network device sends a handover command to the terminal device. The handover command includes the C-RNTI allocated by the second access network device to the terminal device.

[0219] 1209. The first access network device sends a first message to the second access network device, where the first message is used to inform the second access network device which PDCP SDU data packets are received and which are not received. Exemplarily, the first message is a sequence number (SN) state transfer message.

[0220] At 1210, after receiving the handover command from the first access network device, the terminal device attempts to establish a connection with the second access network device. If the terminal device successfully connects to the second access network device, the terminal device sends a handover completion message to the second access network device and disconnects from the first access network device. Correspondingly, the second access network device receives the handover completion message from the terminal device. Step 1210 can be performed before step 1209, or simultaneously with step 1209.

[0221] 1211. The second access network device sends a path switching request message to the first controller. The path switching request message is used to request to change the forwarding address of the downlink data so that the core network subsequently sends the downlink data of the terminal device to the second access network device instead of the first access network device.

[0222] 1212. After receiving the path switch request message, the first controller notifies the user plane unit or other core network element to perform path switch. If the path switch is successful, the first controller replies with a path switch request confirmation message to the second access network device.

[0223] 1213. The second access network device sends a context notification message of releasing the terminal device to the first access network device, so that the first access network device releases the context of the terminal device.

[0224] Optionally, the first controller does not send the first information to the first access network device; the first access network device sends the third measurement report information to the first controller, and the first controller makes a switching decision to switch the terminal device from the source cluster to the target cluster based on the first information and the third measurement report information. After the first controller makes the switching decision to switch the terminal device from the source cluster to the target cluster, the first controller may notify the first access network device included in the source cluster to initiate a switching request to the second access network device included in the target cluster; alternatively, the first controller may notify the second access network device to switch the terminal device from the source cluster to the target cluster, and the first controller may initiate the switching request.

[0225] Figure 13 is another schematic flow diagram of the communication method provided in an embodiment of the present application. In this example, the first access network device does not need to obtain the channel quality of at least one candidate access network device included in the multiple candidate clusters, which can be understood as the above-mentioned blind mode; and the first controller is connected to the access network device included in the source cluster via a wired connection, and the second controller is connected to the candidate access network devices included in the multiple candidate clusters via a wired connection. The first controller can communicate directly with the access network device included in the source cluster, and the second controller can communicate directly with the candidate access network devices included in the multiple candidate clusters. The specific process is as follows.

[0226] 1301. A first controller sends a second request message to a second controller, where the second request message is used to obtain channel quality information of multiple candidate access network devices.

[0227] The first controller and the second controller may be connected via an interface. For example, when the first controller and the second controller are network elements in the RAN, the first controller and the second controller may be connected via an Xn interface; when the first controller and the second controller are network elements in the core network, the first controller and the second controller may be connected via an Ng interface.

[0228] 1302 : After receiving the second request message from the first controller, the second controller sends channel quality information of multiple candidate access network devices to the first controller.

[0229] At 1303, the first controller receives channel quality information of multiple candidate access network devices from the second controller. The first controller determines first information based on the channel quality information of the multiple candidate access network devices. The first information includes identification information corresponding to at least one candidate access network device included in each of the multiple candidate clusters and priority information of the multiple candidate clusters. The performance of both the source cluster and the candidate clusters meets certain conditions.

[0230] 1304. The first controller sends first information to the first access network device. Correspondingly, the first access network device receives the first information from the first controller. The first access network device is an access network device included in the source cluster currently accessed by the terminal device.

[0231] 1305. The terminal device sends first measurement report information to the first access network device. The first measurement report information indicates the channel quality of the access network device included in the source cluster.

[0232] At 1306, the first access network device receives first measurement report information from the terminal device. Based on the first measurement report information and the first information, the first access network device determines to switch the terminal device from the source cluster to the target cluster. The target cluster is a candidate cluster among the multiple candidate clusters whose priority is greater than or equal to a preset threshold. Exemplarily, the target cluster is the candidate cluster with the highest priority among the multiple candidate clusters; alternatively, the target cluster is a candidate cluster randomly selected from the multiple candidate clusters whose priorities are greater than or equal to the preset threshold.

[0233] 1307. The first access network device sends a switching request message to the first controller. The switching request message includes identification information corresponding to at least one candidate access network device included in the target cluster. The switching request message is used to request switching of the terminal device from the source cluster to the target cluster.

[0234] 1308. The first controller receives a switching request message from the first access network device; the first controller sends a context establishment request message of the terminal device to the second controller, where the context establishment request message of the terminal device is used to request that the terminal device be switched from the source cluster to the target cluster, and the context establishment request message of the terminal device includes identification information corresponding to at least one candidate access network device included in the target cluster.

[0235] At 1309, the second controller receives a context establishment request message from the terminal device of the first controller and allows the terminal device to be switched from the source cluster to the target cluster. For example, after receiving the context establishment request message from the terminal device of the first controller, if the second controller determines that the target cluster includes candidate access network devices with low load and available time-frequency resources, the second controller allows the terminal device to be switched from the source cluster to the target cluster.

[0236] 1310. The second controller sends a handover notification message to a second access network device, where the handover notification message is used to notify the second access network device to handover the terminal device from the source cluster to the target cluster. The second access network device is a candidate access network device included in the target cluster.

[0237] 1311. After receiving the switching notification message from the second controller, the second access network device sends a switching notification confirmation message to the second controller. The switching notification confirmation message includes the C-RNTI allocated by the second access network device to the terminal device.

[0238] 1312. The second controller sends a context establishment request confirmation message of the terminal device to the first controller; correspondingly, the first controller receives the context establishment request confirmation message of the terminal device from the second controller, and the context establishment request confirmation message of the terminal device includes the C-RNTI allocated by the second access network device to the terminal device.

[0239] 1313. The first controller sends a switching request confirmation message to the first access network device. The switching request confirmation message indicates that the terminal device is allowed to be switched from the source cluster to the target cluster. The switching request confirmation message includes the C-RNTI allocated by the second access network device to the terminal device.

[0240] 1314. After the first access network device receives the handover request confirmation message from the first controller, the first access network device sends a handover command to the terminal device. The handover command includes the C-RNTI allocated by the second access network device to the terminal device.

[0241] 1315. The first access network device sends a first message to the second access network device, where the first message is used to inform the second access network device which PDCP SDU data packets are received and which are not received. Exemplarily, the first message is an SN state transfer message.

[0242] At 1316, after receiving the handover command from the first access network device, the terminal device attempts to establish a connection with the second access network device. If the terminal device successfully connects to the second access network device, it sends a handover completion message to the second access network device and disconnects from the first access network device. Step 1216 can be performed before step 1215, or simultaneously with step 1215. This is not a limitation.

[0243] 1317. The second access network device sends a path switching request message to the second controller. The path switching request message is used to request to change the forwarding address of the downlink data so that the core network subsequently sends the downlink data of the terminal device to the second access network device instead of the first access network device.

[0244] 1318. After receiving the path switch request message, the second controller notifies the user plane unit or other core network elements to perform path switch. If the path switch is successful, the second controller replies with a path switch request confirmation message to the second access network device.

[0245] 1319. The second access network device sends a context notification message for releasing the terminal device to the second controller, so that the first access network device releases the context of the terminal device; the second controller forwards the context notification message for releasing the terminal device to the first controller, and the first controller sends a context notification message for releasing the terminal device to the first access network device.

[0246] Optionally, the first controller does not send the first information to the first access network device; the first access network device sends the third measurement report information to the first controller, and the first controller makes a switching decision to switch the terminal device from the source cluster to the target cluster based on the first information and the third measurement report information.

[0247] The above describes the communication method provided in the embodiments of the present application. The following describes the execution entity used to execute the above communication method.

[0248] FIG14 is a schematic block diagram of a communication device 1400 according to an embodiment of the present application. The device can be applied to a first communication device according to an embodiment of the present application, which can be a first access network device. The communication device 1400 includes:

[0249] An acquiring unit 1410 is configured to acquire first information, where the first information includes identification information corresponding to at least one candidate access network device included in each of a plurality of candidate clusters, where the device is an access network device included in a source cluster currently accessed by the second communication device;

[0250] The acquiring unit 1410 is further configured to acquire first measurement report information;

[0251] The transceiver unit 1420 is used to send a switching request message, where the switching request message is used to request that the second communication device be switched from the source cluster to a target cluster, where the target cluster is determined based on the first information and the first measurement report information, and the target cluster is included in the multiple candidate clusters.

[0252] Optionally, the acquiring unit 1410 is specifically configured to receive the first information from a third communication device.

[0253] Optionally, the first measurement report information indicates a channel quality of at least one candidate access network device included in each of the multiple candidate clusters.

[0254] Optionally, the transceiver unit 1420 is further configured to send second information to the second communication device, where the second information includes identification information corresponding to at least one candidate access network device included in each of the multiple candidate clusters;

[0255] The acquiring unit 1410 is specifically configured to receive the first measurement report information from the second communication device.

[0256] Optionally, the acquiring unit 1410 is further configured to acquire second measurement report information, where the second measurement report information indicates a channel quality of an access network device included in the source cluster;

[0257] The transceiver unit 1420 is further configured to send a first request message to the third communication device according to the second measurement report information, where the first request message is used to obtain the first information.

[0258] Optionally, the acquiring unit 1410 is specifically configured to receive the second measurement report information from the second communication device.

[0259] Optionally, the first information also includes priority information of the multiple candidate clusters, and the target cluster is a candidate cluster among the multiple candidate clusters whose priority is greater than or equal to a preset threshold; the first measurement report information indicates the channel quality of the access network device included in the source cluster.

[0260] Optionally, the transceiver unit 1420 is specifically configured to send the handover request message to a fourth communication device, where the fourth communication device is a candidate access network device included in the target cluster.

[0261] Optionally, the transceiver unit 1420 is specifically configured to send the switching request message to a third communication device.

[0262] Optionally, the candidate cluster satisfies at least one of the following: the average frequency efficiency of the at least one candidate access network device included in the candidate cluster is greater than or equal to a first threshold; the average throughput of the at least one candidate access network device included in the candidate cluster is greater than or equal to a second threshold; or, the average communication rate of the at least one candidate access network device included in the candidate cluster is greater than or equal to a third threshold.

[0263] Optionally, the source cluster satisfies at least one of the following: the channel quality of at least one access network device included in the source cluster is greater than or equal to a first threshold; the throughput of the at least one access network device included in the source cluster is greater than or equal to a second threshold; or, the average communication rate of the at least one access network device included in the source cluster is greater than or equal to a third threshold.

[0264] FIG15 is a schematic block diagram of another communication device 1500 according to an embodiment of the present application. The device can be applied to the third communication device according to an embodiment of the present application, and the third communication device can be the first controller. The communication device 1500 includes:

[0265] The processing unit 1510 is configured to determine first information, where the first information includes identification information corresponding to at least one candidate access network device included in each of the plurality of candidate clusters;

[0266] The transceiver unit 1520 is configured to send the first information to a first communication device, where the first communication device is an access network device included in a source cluster currently accessed by the second communication device.

[0267] Optionally, the processing unit 1510 is specifically configured to determine the first information based on channel quality information of a plurality of candidate access network devices.

[0268] Optionally, the transceiver unit 1520 is further used to receive a first request message from the first communication device, where the first request message is used to obtain the first information.

[0269] Optionally, the first information further includes priority information of the multiple candidate clusters.

[0270] Optionally, the transceiver unit 1520 is further configured to:

[0271] Sending a second request message to the fifth communication device, where the second request message is used to obtain channel quality information of the multiple candidate access network devices;

[0272] Receive channel quality information of the plurality of candidate access network devices from the fifth communication apparatus.

[0273] Optionally, the transceiver unit 1520 is further configured to:

[0274] receiving a handover request message from the first communication device, the handover request message being used to request handover of the second communication device from the source cluster to a target cluster, the target cluster being included in the plurality of candidate clusters;

[0275] sending a context establishment request message of the second communication device to the fifth communication device;

[0276] A context establishment request confirmation message of the second communication device is received from the fifth communication device.

[0277] FIG16 is a schematic block diagram of another communication device 1600 according to an embodiment of the present application. The device can be applied to a second communication device according to an embodiment of the present application, and the second communication device can be a terminal device. The communication device 1600 includes:

[0278] The transceiver unit 1610 is configured to receive second information from a first communication device, the second information including identification information corresponding to at least one candidate access network device included in each of a plurality of candidate clusters, the first communication device being an access network device included in a source cluster to which the device is currently accessing;

[0279] The transceiver unit 1610 is further configured to send first measurement report information to the first communication device, where the first measurement report information indicates a channel quality of at least one candidate access network device included in each of the multiple candidate clusters.

[0280] Optionally, the transceiver unit 1610 is further configured to send second measurement report information to the first communication device, where the second measurement report information indicates a channel quality of an access network device included in the source cluster.

[0281] FIG17 is a schematic block diagram of another communication device 1700 according to an embodiment of the present application. The device can be applied to a second communication device according to an embodiment of the present application, and the second communication device can be a terminal device. The communication device 1700 includes:

[0282] The transceiver unit 1710 is configured to send first measurement report information to a first communication device, where the first measurement report information indicates a channel quality of an access network device included in a source cluster to which the device is currently accessing, and the first communication device is an access network device included in the source cluster.

[0283] Optionally, the source cluster satisfies at least one of the following:

[0284] The channel quality of at least one access network device included in the source cluster is greater than or equal to a first threshold;

[0285] The throughput of the at least one access network device included in the source cluster is greater than or equal to a second threshold; or,

[0286] An average communication rate of the at least one access network device included in the source cluster is greater than or equal to a third threshold.

[0287] FIG18 is a schematic block diagram of a communication device 1800 according to an embodiment of the present application. The communication device 1800 includes a processor 1810 and a communication interface 1830 . In one possible implementation, the communication device further includes a memory 1820 .

[0288] The memory 1820 is used to store computer programs;

[0289] The processor 1810 is coupled to the memory 1820 via the communication interface 1830. The processor 1810 is configured to call and execute the computer program in the memory 1820 to implement the method in the embodiment of the present application. The communication device can be applied to the first device or the second device in the embodiment of the present application. Optionally, the processor 1810 and the memory 1820 are integrated together.

[0290] The processor 1810 described above may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above-described method embodiment may be completed by hardware integrated logic circuits within the processor or by software instructions. The processor described above may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component. The methods, steps, and logic block diagrams disclosed in the embodiments of this application may be implemented or executed. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the embodiments of this application may be directly implemented and executed by a hardware decoding processor, or by a combination of hardware and software modules within the decoding processor. The software module may be located in a storage medium well-known in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. The storage medium is located in a memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above-described method.

[0291] Optionally, an embodiment of the present application also provides a communication device, which includes an input and output interface and a logic circuit, wherein the input and output interface is used to obtain input information and / or output information; the logic circuit is used to execute the method in any of the above method embodiments, and process and / or generate output information based on the input information.

[0292] An embodiment of the present application provides a communication system, including a first communication device (first access network device), a second communication device (terminal device) and a third communication device (first controller) in the communication method of the embodiment of the present application.

[0293] An embodiment of the present application provides a communication system, including the first communication device and the third communication device in the communication method of the embodiment of the present application.

[0294] The present application also provides a computer-readable storage medium storing a computer program for implementing the method in the above method embodiment. When the computer program is executed on a computer, the computer can implement the method in the above method embodiment.

[0295] An embodiment of the present application further provides a computer program product, which includes computer program code. When the computer program code runs on a computer, the method in the above method embodiment is executed.

[0296] An embodiment of the present application also provides a chip, including a processor, wherein the processor is coupled to a memory, the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the chip executes the method in the above method embodiment.

[0297] It should be understood that in the embodiments of the present application, the numbers "first", "second", etc. are only used to distinguish different objects, such as to distinguish different communication devices, information, etc., and do not constitute a limitation on the scope of the embodiments of the present application. The embodiments of the present application are not limited to this.

[0298] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0299] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0300] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0301] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0302] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0303] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0304] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A communication method, characterized in that: include: The first communication device acquires first information, where the first information includes identification information corresponding to at least one candidate access network device respectively included in a plurality of candidate clusters, and the first communication device is an access network device included in a source cluster currently accessed by the second communication device; The first communication device obtains first measurement report information; The first communication device sends a switching request message, where the switching request message is used to request that the second communication device be switched from the source cluster to a target cluster, where the target cluster is determined based on the first information and the first measurement report information, and the multiple candidate clusters include the target cluster.

2. The method according to claim 1, characterized in that The first communication device acquires first information, including: The first communication device receives the first information from a third communication device.

3. The method according to claim 1 or 2, characterized in that: The first measurement report information indicates a channel quality of at least one candidate access network device respectively included in the multiple candidate clusters.

4. The method according to claim 3, characterized in that: The method further includes: the first communication device sending second information to the second communication device, the second information including identification information corresponding to at least one candidate access network device respectively included in the multiple candidate clusters; The first communication device acquires first measurement report information, including: the first communication device receives the first measurement report information from the second communication device.

5. The method according to any one of claims 2 to 4, characterized in that The method further comprises: The first communication device obtains second measurement report information, where the second measurement report information indicates a channel quality of an access network device included in the source cluster; The first communication device sends a first request message to the third communication device according to the second measurement report information, where the first request message is used to obtain the first information.

6. The method according to claim 5, characterized in that The first communication device obtains second measurement report information, including: The first communication device receives the second measurement report information from the second communication device.

7. The method according to claim 1 or 2, characterized in that: The first information further includes priority information of the multiple candidate clusters, and the target cluster is a candidate cluster whose priority is greater than or equal to a preset threshold among the multiple candidate clusters; The first measurement report information indicates channel quality of the access network device included in the source cluster.

8. The method according to any one of claims 1 to 7, characterized in that The first communication device sending a switching request message includes: The first communication device sends the switching request message to a fourth communication device, where the fourth communication device is a candidate access network device included in the target cluster.

9. The method according to any one of claims 1 to 7, characterized in that The first communication device sending a switching request message includes: The first communication device sends the switching request message to the third communication device.

10. The method according to any one of claims 1 to 9, characterized in that The candidate cluster satisfies at least one of the following: The average frequency efficiency of the at least one candidate access network device included in the candidate cluster is greater than or equal to a first threshold; The average throughput of the at least one candidate access network device included in the candidate cluster is greater than or equal to a second threshold; or, An average communication rate of the at least one candidate access network device included in the candidate cluster is greater than or equal to a third threshold.

11. The method according to any one of claims 1 to 10, characterized in that The source cluster satisfies at least one of the following: The channel quality of at least one access network device included in the source cluster is greater than or equal to a first threshold; The throughput of the at least one access network device included in the source cluster is greater than or equal to a second threshold; or, An average communication rate of the at least one access network device included in the source cluster is greater than or equal to a third threshold.

12. A method of communication, characterized in that: include: The third communication device determines first information, where the first information includes identification information corresponding to at least one candidate access network device respectively included in the plurality of candidate clusters; The third communication device sends the first information to the first communication device, where the first communication device is an access network device included in a source cluster currently accessed by the second communication device.

13. The method according to claim 12, characterized in that The third communication device determines the first information, including: The third communication device determines the first information according to the channel quality information of the plurality of candidate access network devices.

14. The method according to claim 12 or 13, characterized in that The method further comprises: The third communication device receives a first request message from the first communication device, where the first request message is used to obtain the first information.

15. The method according to claim 12 or 13, characterized in that The first information further includes priority information of the multiple candidate clusters.

16. The method according to any one of claims 12 to 15, characterized in that The method further comprises: The third communication device sends a second request message to the fifth communication device, where the second request message is used to obtain channel quality information of the plurality of candidate access network devices; The third communication device receives the channel quality information of the plurality of candidate access network devices from the fifth communication device.

17. The method according to claim 16, characterized in that The method further comprises: The third communication device receives a switching request message from the first communication device, the switching request message being used to request switching the second communication device from the source cluster to a target cluster, the multiple candidate clusters including the target cluster; The third communication device sends a context establishment request message of the second communication device to the fifth communication device; The third communication device receives a context establishment request confirmation message of the second communication device from the fifth communication device.

18. A method of communication, characterized in that: include: The second communication device receives second information from the first communication device, where the second information includes identification information corresponding to at least one candidate access network device respectively included in a plurality of candidate clusters, and the first communication device is an access network device included in a source cluster currently accessed by the second communication device; The second communication device sends first measurement report information to the first communication device, where the first measurement report information indicates a channel quality of at least one candidate access network device respectively included in the multiple candidate clusters.

19. The method according to claim 18, characterized in that The method further comprises: The second communication device sends second measurement report information to the first communication device, where the second measurement report information indicates a channel quality of an access network device included in the source cluster.

20. A method of communication, characterized in that: include: The second communication device sends first measurement report information to the first communication device, where the first measurement report information indicates a channel quality of an access network device included in a source cluster currently accessed by the second communication device, and the first communication device is an access network device included in the source cluster.

21. The method according to claim 20, characterized in that The source cluster satisfies at least one of the following: The channel quality of at least one access network device included in the source cluster is greater than or equal to a first threshold; The throughput of the at least one access network device included in the source cluster is greater than or equal to a second threshold; or, An average communication rate of the at least one access network device included in the source cluster is greater than or equal to a third threshold.

22. A communication device, characterized in that: include: an acquiring unit, configured to acquire first information, wherein the first information includes identification information corresponding to at least one candidate access network device respectively included in a plurality of candidate clusters, wherein the device is an access network device included in a source cluster currently accessed by the second communication device; The acquiring unit is further configured to acquire first measurement report information; A transceiver unit is used to send a switching request message, wherein the switching request message is used to request to switch the second communication device from the source cluster to a target cluster, the target cluster is determined based on the first information and the first measurement report information, and the multiple candidate clusters include the target cluster.

23. The device according to claim 22, characterized in that The acquiring unit is specifically configured to receive the first information from a third communication device.

24. The device according to claim 22 or 23, characterized in that The first measurement report information indicates a channel quality of at least one candidate access network device respectively included in the multiple candidate clusters.

25. The device according to claim 24, characterized in that The transceiver unit is further configured to send second information to the second communication device, where the second information includes identification information corresponding to at least one candidate access network device respectively included in the multiple candidate clusters; The acquiring unit is specifically configured to receive the first measurement report information from the second communication device.

26. The device according to any one of claims 23 to 25, characterized in that The acquisition unit is further configured to acquire second measurement report information, where the second measurement report information indicates a channel quality of an access network device included in the source cluster; The transceiver unit is further used to send a first request message to the third communication device according to the second measurement report information, where the first request message is used to obtain the first information.

27. The device according to claim 26, characterized in that The acquiring unit is specifically configured to receive the second measurement report information from the second communication device.

28. The device according to claim 22 or 23, characterized in that The first information further includes priority information of the multiple candidate clusters, and the target cluster is a candidate cluster whose priority is greater than or equal to a preset threshold among the multiple candidate clusters; The first measurement report information indicates channel quality of the access network device included in the source cluster.

29. The device according to any one of claims 22 to 28, characterized in that The transceiver unit is specifically configured to send the switching request message to a fourth communication device, where the fourth communication device is a candidate access network device included in the target cluster.

30. The device according to any one of claims 22 to 28, characterized in that The transceiver unit is specifically configured to send the switching request message to the third communication device.

31. The device according to any one of claims 22 to 30, characterized in that The candidate cluster satisfies at least one of the following: The average frequency efficiency of the at least one candidate access network device included in the candidate cluster is greater than or equal to a first threshold; the average throughput of the at least one candidate access network device included in the candidate cluster is greater than or equal to a second threshold; or, An average communication rate of the at least one candidate access network device included in the candidate cluster is greater than or equal to a third threshold.

32. The device according to any one of claims 22 to 31, characterized in that The source cluster satisfies at least one of the following: The channel quality of at least one access network device included in the source cluster is greater than or equal to a first threshold; The throughput of the at least one access network device included in the source cluster is greater than or equal to a second threshold; or, An average communication rate of the at least one access network device included in the source cluster is greater than or equal to a third threshold.

33. A communication device, characterized in that: include: a processing unit, configured to determine first information, wherein the first information includes identification information corresponding to at least one candidate access network device respectively included in the plurality of candidate clusters; The transceiver unit is used to send the first information to a first communication device, where the first communication device is an access network device included in a source cluster currently accessed by the second communication device.

34. The device according to claim 33, characterized in that The processing unit is specifically configured to determine the first information according to channel quality information of a plurality of candidate access network devices.

35. The device according to claim 33 or 34, characterized in that The transceiver unit is further used to receive a first request message from the first communication device, where the first request message is used to obtain the first information.

36. The device according to claim 33 or 34, characterized in that The first information further includes priority information of the multiple candidate clusters.

37. The device according to any one of claims 33 to 36, characterized in that The transceiver unit is also used for: Sending a second request message to a fifth communication device, where the second request message is used to obtain channel quality information of the plurality of candidate access network devices; Receive channel quality information of the plurality of candidate access network devices from the fifth communication apparatus.

38. The device according to claim 37, characterized in that The transceiver unit is also used for: receiving a switching request message from the first communication device, the switching request message being used to request switching the second communication device from the source cluster to a target cluster, the multiple candidate clusters including the target cluster; Sending a context establishment request message of the second communication device to the fifth communication device; A context establishment request confirmation message of the second communication device is received from the fifth communication device.

39. A communication device, characterized in that: include: a transceiver unit, configured to receive second information from a first communication device, wherein the second information includes identification information corresponding to at least one candidate access network device respectively included in a plurality of candidate clusters, and the first communication device is an access network device included in a source cluster currently accessed by the device; The transceiver unit is further configured to send first measurement report information to the first communication device, where the first measurement report information indicates a channel quality of at least one candidate access network device respectively included in the multiple candidate clusters.

40. The device according to claim 39, characterized in that The transceiver unit is further configured to send second measurement report information to the first communication device, where the second measurement report information indicates a channel quality of an access network device included in the source cluster.

41. A communication device, characterized in that: include: The transceiver unit is used to send first measurement report information to a first communication device, where the first measurement report information indicates the channel quality of an access network device included in a source cluster currently accessed by the device, and the first communication device is the access network device included in the source cluster.

42. The device according to claim 41, characterized in that The source cluster satisfies at least one of the following: The channel quality of at least one access network device included in the source cluster is greater than or equal to a first threshold; The throughput of the at least one access network device included in the source cluster is greater than or equal to a second threshold; or, An average communication rate of the at least one access network device included in the source cluster is greater than or equal to a third threshold.

43. A communication device, characterized in that: include: A processor and a memory, the memory being used to store a computer program, the processor being used to execute the computer program stored in the memory, so that the communication device executes the method according to any one of claims 1 to 21.

44. A communication device, characterized in that: include: Input-output interfaces and logic circuits; The input and output interface is used to obtain input information and / or output information; The logic circuit is used to execute the method according to any one of claims 1 to 21, and to process and / or generate the output information according to the input information.

45. A communication system, characterized in that: include: A first communication device, a second communication device and a third communication device, wherein the first communication device is used to implement the method described in any one of claims 1 to 11, the third communication device is used to implement the method described in any one of claims 12 to 17, and the second communication device is used to implement the method described in any one of claims 18 to 21.

46. ​​A communication system, characterized in that: include: A first communication device and a third communication device, wherein the first communication device is used to implement the method according to any one of claims 1 to 11, and the third communication device is used to implement the method according to any one of claims 12 to 17.

47. A computer-readable storage medium, characterized in that include: The computer readable medium stores a computer program; When the computer program is executed on a computer, the computer is caused to execute the method according to any one of claims 1 to 21.

48. A computer program product, characterized in that It comprises a computer program which, when executed, enables the method according to any one of claims 1 to 21 to be implemented.

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