Communication method and communication apparatus

Abstract

Provided are a communication method and a communication device. The method comprises: a core network device or an access network device determining that the load of a first mobile relay exceeds a first preset threshold, determining that the load of a second mobile relay is lower than a second preset threshold, and determining that the movement trajectory of the second mobile relay in a first time period is the same as the movement trajectory of the first mobile relay in the first time period; and controlling a terminal device to migrate from the first mobile relay with a larger load to the second mobile relay with a smaller load, so as to achieve load balancing between the mobile relays. Through load balancing between the mobile relays, the pressure of an individual mobile relay with an excessively large load can be relieved, and part of the pressure is transferred to a mobile relay with a smaller load, which is conducive to improving the performance of the mobile relay and the system throughput, and can avoid the terminal device frequently initiating cell reselection due to the change in the position of the mobile relay, thereby reducing the impact on normal communication of the terminal device.

Description

Technical Field

[0001] This application relates to the field of communications, and more particularly to communication methods and communication devices. Background Technology

[0002] With the development of communication technology, mobile relays have become widely used. A mobile relay is a mobile wireless access network device that integrates a wireless access link and a wireless backhaul link. The wireless access link is the communication link between the terminal device and the mobile relay, while the wireless backhaul link is the communication link between the mobile relay and ground-based, non-mobile wireless access network devices. The wireless backhaul link primarily handles data transmission. Because mobile relays do not require wired transmission networks for data transmission, they are beneficial in scenarios such as outdoors where wired transmission networks are difficult to deploy, reducing the deployment requirements for wired transmission networks. For example, a mobile relay can be a vehicle-mounted relay (VMR). The application of mobile relays allows terminal devices located inside or around a vehicle to connect to the mobile relay and access the network.

[0003] Currently, with the increasing number of terminal devices connected to mobile trunk lines, the load on these lines is also growing. When the load on a particular mobile trunk line becomes too high, it is necessary to migrate the terminal devices from that line to another mobile trunk line to achieve load balancing. However, how to achieve load balancing on mobile trunk lines has become a pressing technical problem that needs to be solved. Summary of the Invention

[0004] This application provides a communication method and a communication device to achieve load balancing of mobile relays.

[0005] In a first aspect, this application provides a communication method that can be executed by a core network device, or by a component (such as a chip, chip system, etc.) configured in the core network device, or by a logic module or software capable of implementing all or part of the functions of the core network device. This application does not limit the scope of the method.

[0006] For example, the method includes: determining that the load of a first mobile relay exceeds a first preset threshold; determining that the load of a second mobile relay is lower than a second preset threshold, and determining that the movement trajectory of the second mobile relay in a first time period is the same as the movement trajectory of the first mobile relay in the first time period; sending information about the second mobile relay to a first access network device, the information about the second mobile relay being used to connect a terminal device to the second mobile relay, wherein the first mobile relay and the second mobile relay are in a mobile state, and the first mobile relay is used to provide relay services between the terminal device and the first access network device.

[0007] It should be understood that the movement trajectory of a mobile relay can refer to the set of locations traversed by the mobile relay. Identical movement trajectories specifically refer to the overlapping or near-overlapping movement trajectories of two or more mobile relays. For example, near-overlapping might mean that the locations of the two or more mobile relays (e.g., the first mobile relay and the second mobile relay) are within a preset distance range.

[0008] Based on the aforementioned technical content, the core network equipment identifies mobile trunks with excessive loads and those with less loads. From the less loaded mobile trunks, a target mobile trunk is selected that shares the same movement trajectory as the excessively loaded mobile trunk within the same time period. Then, information about the second mobile trunk is sent to the first access network equipment to migrate terminal devices from the excessively loaded mobile trunk to the less loaded target mobile trunk, thereby achieving load balancing among the mobile trunks. By achieving load balancing among the mobile trunks, the pressure on individual excessively loaded mobile trunks can be alleviated, transferring some of the pressure to less loaded mobile trunks. This improves the performance of the mobile trunks and reduces the deployment requirements of the wired transmission network, especially in areas where wired transmission networks are difficult to deploy, such as indoors, thus improving system throughput. Furthermore, considering the high mobility of mobile trunks, the core network equipment determines the target mobile trunk for the first mobile trunk based on the movement trajectory of each mobile trunk. Since the movement trajectory of the second mobile relay selected as the target mobile relay is the same as that of the first mobile relay for a period of time (such as the first time period mentioned above), and considering that the terminal devices accessing the first mobile relay usually have the same movement trajectory as the first mobile relay (for example, the first mobile relay and the terminal devices are located inside the same vehicle entity), if some terminal devices are migrated from the first mobile relay to the second mobile relay, the service connection of the terminal devices can be unaffected by the mobility of the second mobile relay during the first time period. This avoids the frequent cell reselection of these terminal devices due to the location change of the second mobile relay, thereby avoiding the increase in signaling overhead and power consumption caused by cell reselection, reducing the impact on the normal communication of the terminal devices, and helping to ensure the transmission performance of the terminal devices.

[0009] In conjunction with the first aspect, in some possible implementations of the first aspect, the method further includes: sending a first duration to the first access network device, wherein after the first duration expires, the first mobile relay is able to provide relay services between the terminal device and the first access network device.

[0010] By sending a first duration to the first access network device, the first access network device can, based on the first duration, migrate terminals requesting access from the first mobile trunk to the second mobile trunk before the first duration expires. After the first duration expires, the device can connect terminals requesting access from the first mobile trunk to the first mobile trunk. This helps avoid problems such as performance degradation that might occur if the terminal device is redirected to the second mobile trunk when the distance between the second and first mobile trunks is far or the movement trajectory is different.

[0011] Optionally, the first duration is less than or equal to the duration of the first time period.

[0012] Since the first mobile relay and the second mobile relay have the same movement trajectory in the first time period, if the first duration is controlled within the duration of the first time period, it can effectively avoid problems such as the degradation of transmission performance that may occur when the terminal device is redirected to the second mobile relay even if the second mobile relay is far away from the first mobile relay or the movement trajectory is different.

[0013] In conjunction with the first aspect, in some possible implementations of the first aspect, before sending the information of the second mobile relay to the first access network device, the method further includes: receiving from the first access network device an identifier of the first mobile relay and a registration request from a terminal device, the identifier of the first mobile relay being used to indicate that the registration request is forwarded to the first access network device via the first mobile relay.

[0014] After receiving the identifier of the first mobile trunk and the registration request message of the terminal device from the core network device, the second mobile trunk information is sent to the first access network device, thereby achieving load balancing of the mobile trunk and realizing the way in which the core network device controls the access of the terminal device to the second mobile trunk at the granularity of the terminal device.

[0015] In conjunction with the first aspect, in some possible implementations of the first aspect, the second mobile relay is used to provide relay services between the terminal device and the second access network device.

[0016] One possibility is that the first access network device and the second access network device are the same access network device. Another possibility is that the first access network device and the second access network device are different access network devices.

[0017] Optionally, the information of the second mobile relay includes the identifier of the second mobile relay, which corresponds to the frequency point of the second mobile relay.

[0018] Regardless of whether the first access network device and the second access network device are the same access network device, the core network device can send the identifier of the second mobile relay to the first access network device, so that the first access network device can obtain the frequency point of the corresponding second mobile relay based on the identifier of the second mobile relay.

[0019] Optionally, the information of the second mobile relay includes the frequency of the second mobile relay.

[0020] Regardless of whether the first access network device and the second access network device are the same access network device, the core network device can send the frequency point of the second mobile relay to the first access network device so that the first access network device can notify the terminal device of the frequency point of the second mobile relay.

[0021] Furthermore, the first access network device and the second access network device are different access network devices, and before sending the information of the second mobile relay to the first access network device, the method further includes: sending the identifier of the second mobile relay to the second access network device; and receiving the frequency point of the second mobile relay from the second access network device.

[0022] That is, the core network device can first send the identifier of the second mobile relay to the second access network device to obtain the frequency point of the corresponding second mobile relay, and then send the obtained frequency point of the second mobile relay to the first access network device.

[0023] In conjunction with the first aspect, in some possible implementations of the first aspect, the method further includes: acquiring the load of the first mobile relay and the second mobile relay.

[0024] It should be understood that the load of a mobile trunk line can be understood as the resources currently occupied by the mobile trunk line. The load can be expressed as a percentage, decimal, etc. The larger the value, the more resources the mobile trunk line is currently occupied, and the greater the load.

[0025] Load information can include the load itself or the number of terminal devices accessing the mobile relay. The number of terminal devices accessing the mobile relay can be used to calculate the load. Therefore, core network equipment can determine the load based on the load information reported by each mobile relay.

[0026] In conjunction with the first aspect, in some possible implementations of the first aspect, the method further includes: acquiring the movement trajectories of the first mobile relay and the second mobile relay. The core network device can acquire the movement trajectories of each mobile relay based on the movement trajectories actively reported by each mobile relay, or it can acquire the movement trajectories of the mobile relays by performing location monitoring. This application does not limit this aspect.

[0027] Secondly, this application provides a communication method, which can be executed by a first access network device, or by a component (such as a chip, chip system, etc.) configured in the first access network device, or by a logic module or software capable of implementing all or part of the functions of the first access network device. This application does not limit the scope of the method.

[0028] For example, the method includes: receiving information from a core network device about a second mobile relay, the information of which is used to connect a terminal device to the second mobile relay; wherein the terminal device is a terminal device that requested access from a first mobile relay during a first time period, the load of the first mobile relay exceeds a first preset threshold, the load of the second mobile relay is lower than a second preset threshold, and the movement trajectory of the second mobile relay is the same as that of the first mobile relay during the first time period; and sending the frequency point of the second mobile relay to the terminal device, the frequency point of the second mobile relay being used to connect the terminal device to the second mobile relay.

[0029] Based on the above technical content, the first access network device receives information from the core network device about the second mobile trunk and sends the frequency point of the second mobile trunk to the terminal device. This migrates terminal devices requesting access from the overloaded first mobile trunk to the second mobile trunk, which has a lower load and whose movement trajectory within a first time period is the same as that of the first mobile trunk within the same time period. This achieves load balancing among the mobile trunks. By achieving load balancing among the mobile trunks, the pressure on some overloaded mobile trunks can be alleviated, transferring some of the pressure to less loaded mobile trunks. This improves the performance of the mobile trunks and reduces the deployment requirements of the wired transmission network, especially in areas such as indoors where it is difficult to deploy wired transmission networks, thus improving system throughput. Furthermore, since the high mobility of mobile relays is taken into account when determining the target mobile relay for the first mobile relay, the movement trajectory of the second mobile relay selected as the target mobile relay is the same as that of the first mobile relay for a period of time (such as the first time period mentioned above). Moreover, considering that the terminal devices accessing the first mobile relay usually have the same movement trajectory as the first mobile relay (for example, the first mobile relay and the terminal devices are located inside the same vehicle entity), if some terminal devices are migrated from the first mobile relay to the second mobile relay, the service connection of the terminal devices can be unaffected by the mobility of the second mobile relay during the first time period. This avoids the frequent cell reselection of these terminal devices due to the location change of the second mobile relay, thereby avoiding the increase in signaling overhead and power consumption caused by cell reselection, reducing the impact on the normal communication of the terminal devices, and helping to ensure the transmission performance of the terminal devices.

[0030] In conjunction with the second aspect, in some possible implementations of the second aspect, the method further includes: receiving a first duration from the core network device, and after the first duration expires, continuing to provide relay services between the terminal device and the first access network device.

[0031] By receiving a first time interval from the core network equipment, the first access network equipment can, based on this first time interval, migrate terminals requesting access from the first mobile trunk to the second mobile trunk before the first time interval expires. After the first time interval expires, it can connect terminals requesting access from the first mobile trunk to the first mobile trunk. This helps avoid problems such as performance degradation that might occur if the terminal equipment is redirected to the second mobile trunk when the second mobile trunk is far from the first mobile trunk or the movement trajectory is different.

[0032] Optionally, the first duration is less than or equal to the duration of the first time period.

[0033] Since the first mobile relay and the second mobile relay have the same movement trajectory in the first time period, if the first duration is controlled within the duration of the first time period, it can effectively avoid the problems of frequent cell reselection and transmission performance degradation that may occur when the terminal device is redirected to the second mobile relay even if the second mobile relay is far away from the first mobile relay or the movement trajectory is different.

[0034] In conjunction with the second aspect, in some possible implementations of the second aspect, before receiving information about the second mobile relay from the core network device, the method further includes: receiving a radio resource control (RRC) message from the terminal device, the RRC message carrying a registration request message for requesting access from the first mobile relay; and forwarding the registration request message and the identifier of the first mobile relay to the core network device.

[0035] After receiving the RRC message from the terminal device, the first access network device forwards the registration request message and the identifier of the first mobile trunk in the RRC message to the core network device, and then receives the information of the second mobile trunk from the core network device. This enables load balancing of the mobile trunk and allows the core network device to control the terminal device's access to the second mobile trunk at the terminal device level.

[0036] In conjunction with the second aspect, in some possible implementations of the second aspect, the second mobile relay is used to provide relay services between the terminal device and the second access network device.

[0037] One possibility is that the first access network device and the second access network device are the same access network device. Another possibility is that the first access network device and the second access network device are different access network devices.

[0038] Optionally, the information of the second mobile relay includes the identifier of the second mobile relay, and the identifier of the second mobile relay corresponds to the frequency point of the second mobile relay.

[0039] Regardless of whether the first access network device and the second access network device are the same access network device, the core network device can send the frequency point of the second mobile relay to the first access network device so that the first access network device can notify the terminal device of the frequency point of the second mobile relay.

[0040] Furthermore, the first access network device and the second access network device are different access network devices. The method further includes: sending a request message to the second access network device, the request message carrying an identifier of the second mobile relay, the request message being used to request the frequency point of the second mobile relay, and requesting that the terminal device be connected to the second mobile relay; and receiving a response message from the second access network device, the response message including the frequency point of the second mobile relay.

[0041] By sending the identifier of the second mobile relay to the second access network device through the first access network device, the frequency point of the second mobile relay can be easily obtained, and the basic conditions for migrating the terminal device from the first mobile relay connected to the first access network device to the second mobile relay connected to the second access network device are provided.

[0042] Optionally, the information of the second mobile relay includes the frequency of the second mobile relay, which is used to provide relay services between the terminal equipment and the second access network equipment.

[0043] Regardless of whether the first access network device and the second access network device are the same access network device, the core network device can send the frequency point of the second mobile relay to the first access network device so that the first access network device can notify the terminal device of the frequency point of the second mobile relay.

[0044] Thirdly, this application provides a communication method that can be executed by a first access network device, or by a component (such as a chip, chip system, etc.) configured in the first access network device, or by a logic module or software capable of implementing all or part of the functions of the first access network device. This application does not limit the scope of the method.

[0045] For example, the method includes: determining that the load of a first mobile relay exceeds a first preset threshold; determining that the load of a second mobile relay is lower than a second preset threshold, and determining that the movement trajectory of the second mobile relay in a first time period is the same as the movement trajectory of the first mobile relay in the first time period; determining that a terminal device requests access from the first mobile relay at a first moment in the first time period, and sending the frequency point of the second mobile relay to the terminal device, wherein the frequency point of the second mobile relay is used by the terminal device to access the second mobile relay.

[0046] It should be understood that the first access network device can redirect a terminal device to the second mobile trunk when it determines that a terminal device requests access from the first mobile trunk. That is, load balancing between mobile trunks is achieved at the granularity of the terminal device.

[0047] Based on the above scheme, the access network equipment identifies mobile trunks with excessive loads and those with less loads. From the less loaded mobile trunks, it identifies those with the same movement trajectory as the excessively loaded ones within the same time period, designating them as target mobile trunks. This controls the migration of terminal devices from the excessively loaded mobile trunks to the less loaded ones, achieving load balancing among the mobile trunks. By achieving load balancing among mobile trunks, the pressure on some excessively loaded mobile trunks can be alleviated, transferring some of the pressure to less loaded ones, which is beneficial for improving mobile trunk performance and reducing the deployment requirements of wired transmission networks. This is particularly beneficial for improving system throughput in areas where wired transmission networks are difficult to deploy, such as indoors. Furthermore, considering the high mobility of mobile trunks, the first access network equipment determines the target mobile trunk for the first mobile trunk based on the movement trajectory of each mobile trunk. Since the movement trajectory of the second mobile relay selected as the target mobile relay is the same as that of the first mobile relay for a period of time (such as the first time period mentioned above), and considering that the terminal devices accessing the first mobile relay usually have the same movement trajectory as the first mobile relay (for example, the first mobile relay and the terminal devices are located inside the same vehicle entity), migrating some terminal devices from the first mobile relay to the second mobile relay can ensure that the service connections of the terminal devices are not affected by the mobility of the second mobile relay during the first time period. This avoids the frequent cell reselection of these terminal devices due to the change of the mobile relay's location, thereby avoiding the increase in signaling overhead and power consumption caused by cell reselection, reducing the impact on the normal communication of the terminal devices, and helping to ensure the transmission performance of the terminal devices.

[0048] In conjunction with the third aspect, in some possible implementations of the third aspect, the method further includes: obtaining the loads of the first mobile trunk and the second mobile trunk; and sending the loads of the first mobile trunk and the second mobile trunk to the core network equipment.

[0049] In conjunction with the third aspect, in some possible implementations of the third aspect, the method further includes: acquiring the movement trajectories of the first mobile relay and the second mobile relay; and sending the movement trajectories of the first mobile relay and the second mobile relay to the core network equipment.

[0050] For details regarding load, load information, and movement trajectory, please refer to the relevant explanations in the first section; they will not be repeated here.

[0051] Fourthly, this application provides a communication method that can be executed by a second access network device, or by a component (such as a chip, chip system, etc.) configured in the second access network device, or by a logic module or software capable of implementing all or part of the functions of the second access network device. This application does not limit the scope of the method.

[0052] For example, the method includes: receiving a request message carrying an identifier of a second mobile relay, the request message being used to request a frequency point of the second mobile relay and to request a terminal device to access the second mobile relay, the terminal device being a terminal device that requested access from a first mobile relay within a first time period, the load of the first mobile relay exceeding a first preset threshold, the load of the second mobile relay being below a second preset threshold, and the movement trajectory of the second mobile relay being the same as the movement trajectory of the first mobile relay within the first time period; and sending a response message based on the request message, the response message including the frequency point of the second mobile relay.

[0053] Based on the above technical content, when the first mobile relay and the second mobile relay are connected to different access network devices, the frequency point of the second mobile relay can be obtained from the second access network device through interaction with the second access network device, which provides the basic conditions for migrating the terminal device from the first mobile relay connected to the first access network device to the second mobile relay connected to the second access network device.

[0054] In conjunction with the fourth aspect, in some possible implementations of the fourth aspect, receiving the request message includes: receiving the request message from a core network device, the core network device being the core network device serving the first mobile trunk and the second mobile trunk; and sending a response message based on the request message, including: sending a response message to the core network device based on the request message.

[0055] In conjunction with the fourth aspect, in some possible implementations of the fourth aspect, receiving the request message includes: receiving the request message from a first access network device, the first access network device being an access network device serving the first mobile trunk; and sending a response message based on the request message, including: sending a response message to the first access network device based on the request message.

[0056] When the second mobile trunk and the first mobile trunk are connected to different access network devices, the second access network device to which the second mobile trunk is connected can provide the frequency points of the second mobile trunk to the core network device or the first access network device, thereby providing the basic conditions for migrating terminal devices from the first mobile trunk to the second mobile trunk.

[0057] Fifthly, a communication apparatus is provided, comprising modules or units for implementing the methods of the first to fourth aspects and any possible implementation thereof. It should be understood that each module or unit may implement its respective function by executing a computer program.

[0058] In a sixth aspect, this application provides a communication device, including a processor, the processor being configured to execute the communication methods described in the first to fourth aspects and any possible implementation thereof.

[0059] The device may further include a memory for storing instructions and data. The memory is coupled to the processor, which, when executing the instructions stored in the memory, can implement the methods described in the foregoing aspects. The device may also include a communication interface for communicating with other devices; exemplary, the communication interface may be a transceiver, circuit, bus, module, or other type of communication interface.

[0060] In a seventh aspect, this application provides a chip system including at least one processor for supporting the implementation of the functions involved in the first to fourth aspects and any possible implementation of the first to fourth aspects, such as receiving or processing data and / or information involved in the above methods.

[0061] In one possible design, the chip system also includes a memory for storing program instructions and data, which may be located within or outside the processor.

[0062] The chip system can consist of chips or include chips and other discrete components.

[0063] Eighthly, this application provides a computer-readable storage medium including a computer program that, when run on a computer, causes the computer to implement the methods of the first to fourth aspects and any possible implementation of the first to fourth aspects.

[0064] Ninthly, this application provides a computer program product comprising: a computer program (also referred to as code or instructions) that, when the computer program is run, causes a computer to perform the methods of the first to fourth aspects and any possible implementation thereof. Attached Figure Description

[0065] Figure 1 This is a schematic diagram of the system architecture of the communication method provided in the embodiments of this application.

[0066] Figure 2This is a schematic diagram of a scenario illustrating the communication method provided in an embodiment of this application;

[0067] Figure 3 This is a schematic diagram illustrating the migration of a terminal device between two mobile relays under the same access network device, as provided in the embodiments of this application.

[0068] Figure 4 This is a schematic diagram illustrating the migration of a terminal device between two mobile relays under different access network devices, as provided in the embodiments of this application.

[0069] Figure 5 This is a schematic flowchart of the communication method provided in the embodiments of this application;

[0070] Figure 6 This is a schematic flowchart of a communication method provided in another embodiment of this application;

[0071] Figure 7 This is another illustrative flowchart of a communication method provided in yet another embodiment of this application;

[0072] Figure 8 This is another illustrative flowchart of a communication method provided in yet another embodiment of this application;

[0073] Figures 9 to 10 This is a schematic block diagram of the communication device provided in the embodiments of this application;

[0074] Figure 11 This is a schematic diagram of the structure of the access network device provided in the embodiments of this application. Detailed Implementation

[0075] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0076] The technical solutions provided in this application can be applied to various communication systems, such as 5th Generation (5G) mobile communication systems or new radio access technology (NR). The 5G mobile communication system can include non-standalone (NSA) and / or standalone (SA) networking.

[0077] The technical solutions provided in this application can also be applied to machine-type communication (MTC), long-term evolution-machine (LTE-M) technology, device-to-device (D2D) networks, machine-to-machine (M2M) networks, Internet of Things (IoT) networks, or other networks. Among these, IoT networks may include, for example, vehicle-to-everything (V2X) networks. The communication methods in V2X systems are collectively referred to as vehicle-to-X (V2X), where X can represent anything. For example, V2X may include vehicle-to-vehicle (V2V) communication, vehicle-to-infrastructure (V2I) communication, vehicle-to-pedestrian (V2P) communication, or vehicle-to-network (V2N) communication, etc.

[0078] The technical solution provided in this application can also be applied to future communication systems, such as sixth-generation mobile communication systems. This application does not limit this application.

[0079] Before introducing the communication method provided in the embodiments of this application in detail, a brief introduction to each network element involved in this application will be given first:

[0080] 1. Terminal equipment: can be called user equipment (UE), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication equipment, user agent, or user device.

[0081] Terminal devices can be devices that provide voice / data connectivity to users, such as handheld devices with wireless connectivity, in-vehicle devices, etc. Currently, some examples of terminals include: mobile phones, tablets, computers with wireless transceiver capabilities (such as laptops, PDAs, etc.), mobile internet devices (MIDs), virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical care, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, and personal digital assistants (PDAs). The following are examples of terminal devices: assistant (PDA), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, in-vehicle devices, wearable devices, terminal devices in 5G networks, or terminal devices in future evolved public land mobile networks (PLMNs).

[0082] Furthermore, terminal devices can also be terminal devices in Internet of Things (IoT) systems. IoT is an important component of future information technology development. Its main technical characteristic is connecting objects to networks through communication technologies, thereby realizing an intelligent network that enables human-machine interaction and machine-to-machine interaction. IoT technology can achieve massive connectivity, deep coverage, and low power consumption at the terminal level through technologies such as narrowband (NB).

[0083] In addition, terminal devices may also include sensors such as smart printers, train detectors, and gas stations. Their main functions include collecting data (for some terminal devices), receiving control information and downlink data from network devices, and sending electromagnetic waves to transmit uplink data to network devices.

[0084] 2. Access Network (AN) Equipment: An access network provides network access functionality to authorized users in a specific area and can use transmission tunnels of different quality depending on the user's level and service requirements. Access networks can employ different access technologies. Currently, there are two types of wireless access technologies: 3G Partnership (3GPP)... rd 3GPP (Generation Partnership Project) access technologies (such as radio access technologies used in 3G, 4G, or 5G systems) and non-3GPP access technologies. 3GPP access technologies refer to access technologies that conform to 3GPP standards and specifications; for example, access network equipment in a 5G system is called a next-generation node base station (gNB). Non-3GPP access technologies refer to access technologies that do not conform to 3GPP standards and specifications; for example, air interface technologies represented by access points (APs) in Wi-Fi.

[0085] An access network that uses wireless communication technology to implement access network functions can be called a radio access network (RAN). A RAN manages radio resources, provides access services to terminal devices, and facilitates the forwarding of control signals and user data between the terminal and the core network.

[0086] Wireless access network equipment may include, but is not limited to: radio network controllers (RNCs), node Bs (NBs), base station controllers (BSCs), base transceiver stations (BTSs), home base stations (e.g., home evolved node Bs, or home node Bs, HNBs), baseband units (BBUs), access points (APs), wireless relay nodes, wireless backhaul nodes, transmission points (TPs), or transmission and reception points (TRPs) in Wi-Fi systems. It may also be gNBs or transmission points (TRPs or TPs) in 5G (e.g., NR) systems, one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, or network nodes constituting gNBs or transmission points, such as baseband units (BBUs), distributed units (DUs), or base stations in next-generation 6G communication systems. This application does not limit the specific technologies or equipment forms used in the wireless access network equipment.

[0087] 3. Mobile Relay: This refers to a mobile radio access network (RAN) device that integrates a radio access link and a radio backhaul link. The radio access link is the communication link between the terminal equipment and the mobile relay, while the radio backhaul link is the communication link between the mobile relay and RAN devices deployed on the ground that lack mobility. The radio backhaul link primarily handles data transmission. Mobile relays support interfaces such as Uu, F1, E1, NG, and X2, and include both RAN device functionality and mobile-termination (MT) functionality. The MT function is integrated into the mobile relay and serves as the Uu interface endpoint for the backhaul link between the mobile relay and the host RAN device or other mobile relays. When the mobile relay is activated, the MT function performs cell selection to access the network.

[0088] It is understandable that mobile relays are mobile. For example, a typical mobile relay, also known as a vehicle-mounted relay (VMR), is a relay that integrates wireless access and wireless backhaul links and can move with the vehicle.

[0089] 4. Donor Radio Access Network (RAN) Equipment: This typically refers to terrestrial RAN equipment without mobility. It provides network access to terminal devices through the backhaul link between the donor RAN and mobile trunks, and the access link provided by the mobile trunks. A donor RAN device can consist of a centralized unit (CU) and one or more distributed units (DUs). The CU primarily handles non-real-time higher-layer radio protocol stack functions, such as radio resource control (RRC) layer protocols and packet data convergence protocol (PDCP) layer protocols. The DU primarily handles physical layer (PHY) functions and layer 2 functions with higher real-time requirements, such as the PHY protocol. CUs and DUs can communicate with each other via the F1 interface.

[0090] This application does not limit the number of mobile trunks that the donor RAN can connect to.

[0091] For ease of description, the host radio access network device is referred to as the access network device in this application. Unless otherwise stated, the access network device in the embodiments of this application refers to the host radio access network (donor RAN) device.

[0092] 5. Access and Mobility Management Function (AMF): The AMF is part of the core network and is mainly used for terminal registration, mobility management, and tracking area update processes in the mobile network. The AMF terminates non-access stratum (NAS) messages, is responsible for registration management, connection management, reachability management, allocation of tracking area lists (TA lists), and mobility management, and is also responsible for forwarding session management (SM) messages to the session management network element.

[0093] Figure 1 This is a schematic diagram of the system architecture applicable to the communication method in the embodiments of this application. For example... Figure 1 As shown, the system 100 may include a core network 110, access network equipment 120, mobile trunk 130, and terminal equipment 140.

[0094] The system 100 may be, for example, a 5G system (5GS). In the 5GS, the core network 110 may be a 5G core network (5GC). Exemplarily, the core network 110 may include, but is not limited to, AMF, session management function (SMF), user plane function (UPF), etc. Each network element can be used to implement its respective function. For example, the AMF can be used for mobility management and access management. The SMF can be used for session management, Internet Protocol (IP) address allocation and management of terminal devices, selection and management of user plane functions, policy control, or termination points of charging function interfaces, and downlink data notification, etc. The UPF can be used for packet routing and forwarding, or quality of service (QoS) processing of user plane data, etc. This application does not limit the specific network elements included in the core network 110, nor their functions, quantity, or form.

[0095] Access network device 120 can be connected to core network 110 and can be used to provide network access functions for authorized terminals within the coverage area, manage radio resources, and forward control signals and user data between terminal devices and core network 110.

[0096] In this embodiment of the application, the access network device 120 can not only provide wireless access services for terminal devices, but also for mobile relays (such as... Figure 1 The mobile relay 130 shown provides a wireless backhaul function, enabling the mobile relay to access the core network via the access network device 120. The mobile relay 130 is mobile, for example, it can be deployed in a vehicle, connecting to the access network device 120 via a wireless backhaul link, and then connecting to the core network via the access network device 120. Simultaneously, it provides a wireless access link to nearby terminal devices (including those inside or outside the vehicle), thereby enabling the terminal devices to access the network.

[0097] like Figure 1 The terminal device 140 shown is located outside the vehicle. It can access the mobile relay 130 via the wireless access link provided by the mobile relay 130, and then access the core network 110 via the wireless backhaul link between the access network device 120 and the access mobile relay 130.

[0098] It should be understood that Figure 1The illustration is merely an example, showing a core network, a radio access network device, a mobile relay, and a terminal device, but this should not constitute any limitation on this application. The number of each device can be one or more. There can be one or more access network devices accessing the same core network. The number of mobile relays accessing the same radio access network device can also be one or more. The number of terminal devices accessing the same mobile relay can also be one or more.

[0099] also, Figure 1 Although not shown, it should be understood that terminal device 140 can access the network by connecting to a mobile relay or by accessing a wireless access network device. Furthermore, terminal device 140 can also be located inside the vehicle.

[0100] Figure 2 This is a schematic diagram illustrating a scenario applicable to the communication method provided in the embodiments of this application. For example... Figure 2 As shown, mobile relay 201 and mobile relay 202 are mounted on different vehicles. Mobile relay 201 and the vehicle on which it is mounted share the same movement trajectory, and mobile relay 202 and the vehicle on which it is mounted also share the same movement trajectory. Mobile relay 201 and mobile relay 202 can be connected to the same donor RAN or to different donor RANs; this application does not limit this.

[0101] like Figure 2 As shown, when mobile relay 201 is operating within area 1, terminal devices may continuously connect to the network via mobile relay 201, such as... Figure 2 Terminal devices 1 through n (where n is a positive integer) shown in the diagram all access the core network through mobile trunk 201. As more and more terminal devices request access to mobile trunk 201, the load on mobile trunk 201 increases. However, since there are no other trunks nearby to balance the load, these terminal devices still access the network through mobile trunk 201.

[0102] As mobile relay 201 moves, it gradually enters area 2. If mobile relay 201 is in area 2, and there is a mobile relay 202 nearby with low load on it, then some terminal devices connected to mobile relay 201 can be migrated to mobile relay 202. For example, for terminal devices that have already successfully joined the network (i.e., Figure 2 As shown in the diagram, if terminal devices 1 to n subsequently initiate access requests again through mobile trunk 201, some of the terminal devices connected to mobile trunk 201, such as terminal device n and terminal device n-1, can be migrated to mobile trunk 202. This reduces the number of terminal devices connected to mobile trunk 201 to n-2, alleviating the load on mobile trunk 201 and achieving load balancing. Furthermore, Figure 2 Although not shown, it is understandable that there may be some terminal devices that were not previously connected to mobile relay 201, such as terminal devices in area 2. After mobile relay 201 enters area 2, they may request to join the network through mobile relay 201. These terminal devices may also be migrated to mobile relay 202. Figure 2 The n terminal devices shown are merely examples and should not be construed as limiting.

[0103] As mobile relay 201 continues its journey, if it reaches area 3, and the distance between mobile relay 201 and mobile relay 202 increases, then the migrated mobile terminals need to be migrated back. For example, terminal device n and terminal device n-1 need to be migrated from mobile relay 202 back to mobile relay 201. Understandably, if mobile relay 201 is still overloaded in area 3, a new target mobile relay can be found to balance the load.

[0104] It should be understood that Figure 2 The n terminal devices shown are merely examples. As time progresses, the number of mobile terminals connected to the mobile relay 201 may also change, and this application embodiment does not limit this.

[0105] It should also be understood that Figure 2 The regions 1, 2, and 3 shown are for ease of description only; such regional divisions may not exist in actual scenarios.

[0106] It should also be understood that Figure 2 This is merely an example illustrating two mobile relays. However, this should not be construed as limiting the scope of this application. More mobile relays may be included in each area within this scenario. The embodiments of this application do not limit this. Furthermore, Figure 2 The scenario shown only involves migration of terminal devices that have already successfully joined the network, thereby reducing the load on mobile relays. This application embodiment can also initiate migration for terminal devices that have not successfully joined the network, and this application embodiment does not limit whether the terminal device to be migrated has already successfully joined the network.

[0107] It should also be understood that Figure 2 This is merely an example, showing the migration of two terminal devices accessing mobile trunk 201 to mobile trunk 202. However, this should not be construed as limiting this application. In this scenario, more or fewer terminal devices can be migrated, and terminal devices can also be migrated to other mobile trunks besides mobile trunk 202. This application's embodiments do not limit this.

[0108] Due to the high mobility of mobile relays, the mobile relay 202 used for load balancing as mobile relay 201 may change over time. For example, mobile relays cannot be aware of each other's load status, and it is difficult to know each other's movement trajectory in advance. Figure 2 For mobile relay 201, it is unaware of the load status of mobile relay 202, nor can it know the distance between itself and mobile relay 202, or the future route of mobile relay 202. Therefore, how to find a suitable other mobile relay for load balancing, and thus achieve load balancing among mobile relays, is a technical problem that urgently needs to be solved.

[0109] In view of this, this application provides a communication method that identifies mobile trunks with excessive load and those with less load through core network equipment or access network equipment. Furthermore, it identifies mobile trunks with less load that share the same movement trajectory as the excessively loaded mobile trunks within the same time period, and selects these as target mobile trunks, thereby achieving load balancing among the mobile trunks. In other words, the communication method provided by this application allows core network equipment or access network equipment to control terminal devices to migrate from excessively loaded mobile trunks to less loaded mobile trunks, thus achieving load balancing among the mobile trunks.

[0110] The communication method provided in this application embodiment will be described in detail below with reference to the accompanying drawings, from the perspectives of AMF (an example of core network equipment) control and access network equipment control. For example, Figure 3 and Figure 4 Two scenarios applicable to the embodiments of this application are illustrated. Figure 5 An embodiment of the method is illustrated from the perspective of AMF control or access network equipment control. Figures 6 to 8 This demonstrates the perspective of device interaction. Figure 3 and Figure 4 The two illustrated scenarios demonstrate the implementation of the communication method provided in this application. Figure 6 and Figure 7 The communication method of this application, implemented under AMF control, is illustrated. Figure 8 The communication method of this application, implemented under the control of an access network device, is illustrated.

[0111] To better understand the embodiments of this application, the following points are explained first:

[0112] First, in the embodiments of this application, descriptions such as "when," "under the circumstances," "if," and "if" all refer to the fact that the device (e.g., AMF or access network device) will make corresponding processing under certain objective circumstances. They are not time limits, nor do they require the device (e.g., AMF or access network device) to make a judgment action when implementing it, nor do they imply any other limitations.

[0113] Second, in the embodiments shown below, the terms "first," "second," and various numerical designations are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. For example, they distinguish between different mobile trunks, different access network devices, etc. Those skilled in the art will understand that the terms "first," "second," etc., do not limit the quantity or execution order, and the terms "first," "second," etc., are not necessarily different.

[0114] Third, in the embodiments of this application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates an "or" relationship between the preceding and following related objects, but it does not exclude the possibility of indicating an "and" relationship. The specific meaning can be understood in conjunction with the context. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c; a and b; a and c; b and c; or a and b and c. Here, a, b, and c can be single or multiple.

[0115] Fourth, for ease of understanding and explanation, the following assumptions and definitions are made:

[0116] First mobile trunk: A mobile trunk whose load exceeds a first preset threshold, i.e., a mobile trunk requiring load balancing, also known as a source mobile trunk. The first mobile trunk can be used to provide trunk services between terminal devices and the first access network device.

[0117] Second mobile trunk: A mobile trunk whose load is less than a second preset threshold and whose movement trajectory is the same as that of the first mobile trunk within a certain time period. That is, a mobile trunk that serves as the migration target of a terminal device can also be called a target mobile trunk. The second mobile trunk can be used to provide trunk services between the terminal device and the second access network device.

[0118] It should be understood that both the first preset threshold and the second preset threshold are thresholds used to determine whether the load on the mobile relay is too high. The first preset threshold and the second preset threshold can be the same or different. This application does not limit this.

[0119] First access network device: The host access network device for the first mobile trunk access.

[0120] Second access network equipment: The host access network equipment for the second mobile trunk access.

[0121] It should be noted that the first access network device and the second access network device may be the same access network device or different access network devices. The following embodiments will be described in detail in conjunction with different situations.

[0122] AMF: Refers to the AMF that serves the MT function of the mobile trunk, that is, the AMF registered when the MT of the first mobile trunk and the MT of the second mobile trunk are connected to the network. It can also be simply described as the AMF registered when the first mobile trunk and the second mobile trunk are connected to the network. Unless otherwise specified, it is assumed that the first mobile trunk and the second mobile trunk are registered in the same AMF.

[0123] Below, we will first introduce two possible scenarios in which the communication method provided in the embodiments of this application is applicable. The host wireless access network device will be referred to as the access network device.

[0124] One possibility is that the first access network device and the second access network device are the same access network device. In other words, the first mobile trunk and the second mobile trunk are connected to the same access network device. Therefore, the terminal device can migrate between the two mobile trunks under the same access network device.

[0125] Figure 3 This is a schematic diagram illustrating the migration of terminal devices between two mobile relays under the same access network device. Figure 3 The diagram illustrates an AMF (Access Network Function), an access network device (i.e., a donor RAN), a first mobile trunk and a second mobile trunk, and terminal devices simultaneously located within the service range of both the first and second mobile trunks. The first and second mobile trunks are connected to the same access network device. When the first mobile trunk is overloaded, terminal devices initiating access to the first mobile trunk can be migrated to the second mobile trunk, which has a lower load and whose movement trajectory is similar to that of the first mobile trunk for a certain period of time.

[0126] Another possible scenario is that the first access network device and the second access network device are different access network devices. In other words, the first mobile trunk and the second mobile trunk are connected to different access network devices. Therefore, the terminal device can migrate between two mobile trunks under different access network devices. As the terminal device migrates between the two mobile trunks, the access network device connected to that terminal device (which can be understood as the terminal device connecting to the host access network device through a mobile trunk) also changes.

[0127] Figure 4 This is a schematic diagram illustrating the migration of terminal equipment between two mobile relays under different access network devices. Figure 4The diagram illustrates an AMF (Access Network Function), a first access network device (i.e., a first donor RAN), a second access network device (i.e., a second donor RAN), a first mobile trunk, a second mobile trunk, and terminal devices simultaneously located within the service range of both the first and second mobile trunks. The first mobile trunk is connected to the first access network device, and the second mobile trunk is connected to the second access network device; the first and second access network devices are different access network devices. When the first mobile trunk is overloaded, terminal devices initiating access to the first mobile trunk can be migrated to the second mobile trunk, which has a lower load and whose movement trajectory is similar to that of the first mobile trunk for a certain period of time.

[0128] It should be understood that Figure 3 and Figure 4 This is merely an example illustrating two mobile relays and one terminal device. However, this should not be construed as limiting the scope of this application. For example, each access network device can connect to more than one mobile relay, and the number of terminal devices accessing each mobile relay can also be more than one. The embodiments of this application do not limit this. Furthermore, Figure 3 and Figure 4 In the scenario shown, this application embodiment does not limit whether the terminal device to be migrated to the second mobile relay has successfully joined the network.

[0129] It should also be understood that Figure 3 and Figure 4 This is merely an example, showing one or two access network devices. However, this should not constitute any limitation on this application, and the number of access network devices connected to the AMF may be more than one.

[0130] In other words, the communication method provided in this application embodiment can not only realize the migration of terminal devices between two mobile relays under the same access network device, but also realize the migration of terminal devices between two mobile relays under different access network devices.

[0131] The following is combined Figure 5 The communication method provided in this application is described from the perspective of AMF control or access network equipment control.

[0132] Figure 5 This is a schematic flowchart applicable to the communication method provided in the embodiments of this application. The method 500 includes steps 510 to 530. Wherein, Figure 5 The access network equipment mentioned refers to the donor RAN that is connected to the mobile trunk via a wireless backhaul link.

[0133] It should be understood that method 500 can be executed by the AMF or access network device, or by components (such as circuits, chips, chip systems, etc.) deployed in the AMF or access network device, or by logic modules or software capable of implementing all or part of the functions of the AMF or access network device. This application does not limit this.

[0134] Step 510: Determine that the load of the first mobile relay exceeds the first preset threshold.

[0135] Step 520: Determine that the load of the second mobile relay is lower than the second preset threshold, and determine that the movement trajectory of the second mobile relay in the first time period is the same as the movement trajectory of the first mobile relay in the first time period.

[0136] It should be understood that in steps 510 and 520, the load of the first mobile trunk exceeds a first preset threshold, while the load of the second mobile trunk is below a second preset threshold. This could mean that the load of the first mobile trunk is greater than or equal to the first preset threshold, and the load of the second mobile trunk is less than the second preset threshold; or it could mean that the load of the first mobile trunk is greater than the first preset threshold, and the load of the second mobile trunk is less than or equal to the second preset threshold.

[0137] In one possible implementation, steps 510 to 520 can be performed by the AMF. The AMF can obtain the load of all mobile trunks registered with the AMF. In other words, the AMF can obtain their load regardless of whether these mobile trunks access the network through the same access network device. Therefore, this implementation is applicable to... Figure 3 or Figure 4 The situation is shown.

[0138] In another possible implementation, steps 510 to 520 can be performed by an access network device, such as a first access network device connected to the first mobile trunk. Since the first access network device can acquire the load of the mobile trunk connected to it, this implementation is more suitable for… Figure 3 The situation shown. Of course, this implementation method can also be applied to... Figure 4 The scenario shown is simply that the first access network device may need to obtain the load of other mobile trunks not connected to the first access network device from the core network device or other access network devices.

[0139] The following is a detailed explanation of the specific methods for obtaining the load of a mobile relay.

[0140] Each mobile trunk can periodically report its own load information to the access network equipment it is connected to. As one implementation, the load information may include information on the resources currently occupied on the mobile trunk, the remaining resources (or unoccupied resources), or the number of terminal devices accessing the mobile trunk.

[0141] The resource usage information currently displayed on the mobile trunk is expressed as a percentage or decimal, indicating the amount of resources currently being used. In other words, the resource usage information currently displayed on the mobile trunk represents its current load. For example, a higher value for the resource usage information indicates that more resources are being used on the mobile trunk, suggesting a greater load.

[0142] For example, if the load information reported by the mobile trunk is: the current resource usage on the mobile trunk is 80% or 0.8, then the load can be determined to be 80% or 0.8.

[0143] The remaining resource information on the current mobile trunk can also be used to determine the load. This information can be expressed as a percentage, decimal, etc., to indicate the remaining resources on the current mobile trunk. The smaller the value of the remaining resource information, the more resources are left on the mobile trunk, indicating a lower load.

[0144] For example, if the load information reported by the mobile relay is: the remaining resources on the current mobile relay are 20% or 0.2, then the load of the current first mobile relay can be determined to be 80% or 0.8.

[0145] The number of terminal devices connected to the mobile relay can also be used to determine the load; for example, the more terminal devices there are, the greater the load.

[0146] For example, the load information reported by a mobile trunk line includes the number of terminal devices accessing the line. The AMF (Application Management Function) can obtain the maximum allowed number of terminals to access the mobile trunk line from subscription data, other network elements, or local configuration information. The AMF determines the load of the mobile trunk line based on this maximum allowed number and the current number of terminals accessing it. Assuming the maximum allowed number of terminals is 1000 and the current number is 800, the AMF can calculate the load as 80% or 0.8%. Alternatively, the AMF can send the maximum allowed number of terminals to the mobile trunk line to the access network device (which is the access network device to which the mobile trunk line is connected), allowing the access network device to calculate the load.

[0147] As can be seen, regardless of whether each mobile relay reports information on occupied resources, remaining resources, or the number of terminal devices accessing the mobile relay, all of this information can be converted into load data for comparison with their respective load thresholds. This application does not limit the method used to represent load information.

[0148] It should be understood that the reporting cycle of load information by each mobile relay can be set by those skilled in the art according to actual needs, and this application does not limit it.

[0149] For example, each mobile trunk reports load information to its respective connected access network device. If steps 510 to 520 are performed by the first access network device, the first access network device can directly execute steps 510 and 520 based on the received load information. If steps 510 to 520 are performed by the AMF, the first access network device can forward the load to the AMF, and then the AMF can execute steps 510 and 520 based on the received load information.

[0150] After the AMF or the first access network device obtains the load information of each mobile trunk, it can know the load of each mobile trunk, and then determine the first mobile trunk with excessive load and the second mobile trunk that can be used as the target mobile trunk.

[0151] It is understood that the AMF or the first access network device can determine one or more overloaded mobile trunks based on the received load information, and these one or more overloaded mobile trunks are examples of the first mobile trunks. For each first mobile trunk, the AMF or the first access network device can determine a second mobile trunk for migrating terminal devices. The AMF or access network device can determine one or more first mobile trunks at once, and then determine a second mobile trunk for each first mobile trunk; or it can determine a second mobile trunk for each first mobile trunk determined. This application does not limit the specific implementation process. Without loss of generality, this document uses a first mobile trunk as an example to describe the method provided by the embodiments of this application.

[0152] It should also be understood that this application does not limit the execution order of steps 510 and 520. For example, step 510 can be executed first and then step 520 can be executed, or steps 510 and 520 can be executed simultaneously. For example, the loads of the first mobile relay and the second mobile relay can be obtained at the same time. After determining that the load of the first mobile relay exceeds the first preset threshold, the second mobile relay with a load lower than the preset threshold and the same movement trajectory as the first mobile relay in a certain time period can be further determined.

[0153] As mentioned earlier, the second mobile relay is a mobile relay whose load is less than a second preset threshold and whose movement trajectory is the same as that of the first mobile relay within a certain time period. Here, a time period is a concept with start and end times and duration. For ease of understanding and explanation, this document refers to the duration during which the movement trajectory of the second mobile relay is the same as that of the first mobile relay as the first time period.

[0154] In this context, the movement trajectory of a mobile relay refers to the set of locations traversed by the relay during its movement. The movement trajectory can be understood as the path the relay takes; this path is a vector and has direction. From this path, we can see all the locations the relay passes through from its start to its end. In one possible implementation, the movement trajectory can include the location information of the mobile relay at multiple points in time. By connecting the locations of the mobile relay at each point in time in chronological order, the movement trajectory of the mobile relay can be obtained.

[0155] The same movement trajectory specifically refers to the overlapping or near-overlapping movement trajectories of two or more mobile relays. For example, near-overlapping could mean that the locations of the two or more mobile relays are within a preset distance range.

[0156] In other words, the movement trajectory of the first mobile relay is the same as that of the second mobile relay in the first time period. That is, the distance between the location of the first mobile relay at any point in the first time period and the location of the second mobile relay at the same point in the first time period is less than or equal to a preset distance range.

[0157] For the sake of brevity, unless otherwise specified, the movement trajectory and the fact that the movement trajectory is the same within a certain period of time can be understood by referring to the description above.

[0158] Step 530: Control the terminal device to connect to the second mobile relay.

[0159] Corresponding to the preceding text, in one possible implementation, step 530 can be performed by the AMF. Specifically, when performing step 530, the AMF can send information about the second mobile trunk to the first access network device, so that the terminal device can be controlled to access the second mobile trunk through the first access network device.

[0160] For example, when the first mobile trunk and the second mobile trunk are simultaneously connected to the same first access network device (i.e., for...) Figure 3In this scenario, the information of the second mobile relay can be either the identifier (ID) of the second mobile relay or the cell information of the second mobile relay. The cell information includes at least a frequency point or frequency band. In this embodiment, the cell information can be used to redirect a terminal device from the first mobile relay to the second mobile relay. Since the mobile relay ID corresponds to the cell information, the first access network device can determine the cell information of the second mobile relay based on the identifier of the second mobile relay from the AMF. The first access network device can further send the cell information of the second mobile relay to the terminal device to trigger the terminal device to initiate cell redirection and migrate to the second mobile relay. For simplicity, unless otherwise specified, the cell information will be understood in the following text with reference to the above description.

[0161] When the access network devices connected to the first mobile trunk and the second mobile trunk are different, for Figure 4 In this scenario, the information of the second mobile relay can be its cell information. This cell information can be used to redirect a terminal device from the first mobile relay to the second mobile relay. Since the first and second mobile relays are connected to different access network devices, in this scenario, the AMF needs to send the cell information of the second mobile relay to the first access network device.

[0162] In another possible implementation, step 530 can be performed by the first access network device. When performing step 530, the first access network device can send the cell information of the second mobile relay to the terminal device to trigger the terminal device to initiate cell redirection and migrate to the second mobile relay.

[0163] The details of how the first access network device obtains the cell information of the second mobile trunk will be explained in detail later with reference to different embodiments, and will not be elaborated here.

[0164] It should be noted that the terminal device can be a terminal device requesting access from the first mobile relay. Specifically, it can be a terminal device that has already successfully accessed the network from the first mobile relay and needs to initiate access again due to location updates or service requirements, or it can be an initial access terminal device to the first mobile relay. This application embodiment does not limit this.

[0165] Based on the above scheme, the core network equipment or access network equipment identifies mobile trunks with excessive loads and those with less loads. Furthermore, from the less loaded mobile trunks, those with the same movement trajectory as the excessively loaded mobile trunks within the same time period are selected as target mobile trunks. This allows terminal devices to migrate from the excessively loaded mobile trunks to the less loaded ones, achieving load balancing among the mobile trunks. By achieving load balancing among mobile trunks, the pressure on individual excessively loaded mobile trunks can be alleviated, transferring some of the pressure to less loaded mobile trunks. This improves the performance of mobile trunks and reduces the deployment requirements of wired transmission networks, especially in areas such as indoors where wired transmission networks are difficult to deploy, thus improving system throughput. Furthermore, considering the high mobility of mobile relays, the movement trajectory of the second mobile relay selected as the target mobile relay is the same as that of the first mobile relay in the first time period. Moreover, considering that the terminal devices accessing the first mobile relay usually have the same movement trajectory as the first mobile relay (for example, the first mobile relay and the terminal devices are located inside the same vehicle entity), if some terminal devices are migrated from the first mobile relay to the second mobile relay, the service connections of the terminal devices can be unaffected by the mobility of the second mobile relay in the first time period. This avoids the frequent cell reselection of these terminal devices due to the location change of the second mobile relay, thereby avoiding the increase in signaling overhead and power consumption caused by cell reselection, reducing the impact on the normal communication of the terminal devices, and helping to ensure the transmission performance of the terminal devices.

[0166] Below, in conjunction with Figures 6 to 7 This describes the communication method implemented in this application using AMF.

[0167] Figure 6 This is a schematic flowchart applicable to a communication method provided in another embodiment of this application.

[0168] It should be noted that method 600 is applicable to Figure 3 The diagram illustrates a scenario where a terminal device migrates between mobile trunks within the same access network device. In this case, the first mobile trunk and the second mobile trunk are connected to the same access network device, namely the first access network device.

[0169] It should be understood that, for ease of understanding and illustration, Figure 6 Only the first access network device connected to the AMF, and the first and second mobile trunks connected to the first access network device are shown. In practical applications, the first access network device can connect to more mobile trunks, and the AMF can connect to more access network devices. Figure 6 The access network equipment mentioned refers to the donor RAN that is connected to the mobile trunk via a wireless backhaul link.

[0170] The steps in method 600 are explained in detail below.

[0171] In step 601, the first mobile relay and the second mobile relay register with the network.

[0172] Each mobile trunk can initiate a registration process to join the network through the access network device. For example, the mobile termination (MT) function of each mobile trunk can access the network through cell selection. For example, the MT functions of the first mobile trunk and the second mobile trunk can both join the network by sending a registration request message through the access network device.

[0173] For example, after the first and second mobile trunks are activated, both the MT (Mobile Transmission Function) functions of the first and second mobile trunks can send registration request messages to the first access network device. Correspondingly, upon receiving the registration request message, the first access network device can select an AMF (Application Management Function) for each of the MT functions and send the registration request message to the selected AMF. Since the first and second mobile trunks are connected to the same access network device (i.e., the first access network device), the first access network device can select the same AMF for both the MT functions; that is, the AMF registered by the MT functions of the first and second mobile trunks is usually the same AMF. After receiving the registration request messages from the MT functions of the first and second mobile trunks, the AMF can send registration response messages to both the MT functions of the first and second mobile trunks through the first access network device to accept the registration request messages from both mobile trunks. Thus, the MT function of the first mobile trunk and the MT function of the second mobile trunk successfully joined the network.

[0174] It should be understood that during the registration process of the first and second mobile trunks, the AMF can assign temporary identifiers (IDs) to the MT functions of the first and second mobile trunks respectively, and record the access network devices connected to each mobile trunk. For example, in this embodiment, the AMF can record the context information of the MT function of the first mobile trunk, such as the correspondence between the temporary identifier of the MT function of the first mobile trunk and the ID of the first access network device, and the context information of the MT function of the second mobile trunk, such as the correspondence between the temporary identifier of the MT function of the second mobile trunk and the ID of the first access network device.

[0175] As one implementation, the temporary identifier for the MT function of a mobile trunk can be a globally unique temporary identity (GUTI), and the ID of the first access network device can be a global RAN node ID.

[0176] It should be understood that after receiving registration request messages for the MT function of the first mobile trunk and the MT function of the second mobile trunk, the first access network device can assign RAN UE NGAP IDs to the MT functions of the first and second mobile trunks respectively. These RAN UE NGAP IDs are used by the first access network device to identify the MT functions of the first and second mobile trunks respectively. Here, NGAP stands for Next Generation Application Protocol. The first access network device locally stores the RAN UE NGAP IDs assigned to the MT functions of the first and second mobile trunks. Furthermore, the first access network device can also send the RAN UE NGAP IDs corresponding to the MT functions of each mobile trunk to the AMF, and the AMF will store these RAN UE NGAP IDs in the context of the MT functions of each mobile trunk.

[0177] It should also be understood that, in the embodiments of this application, the meaning of the first mobile trunk and the second mobile trunk registering to the network is the same as the meaning of the MT function of the first mobile trunk and the MT function of the second mobile trunk registering to the network. The meaning of the AMF assigning temporary identifiers to the MT function of the first mobile trunk and the second mobile trunk is the same as the meaning of the AMF assigning temporary identifiers to the first mobile trunk and the second mobile trunk.

[0178] For the sake of brevity, unless otherwise specified, the description of the MT function execution action of the mobile trunk can be simply understood as the execution action of the mobile trunk. In other words, in the embodiments of this application, "MT function of mobile trunk" can be simply replaced with "mobile trunk".

[0179] It should also be understood that the specific details of the registration process can be found in the existing network access process for terminal devices, and will not be elaborated here for the sake of brevity.

[0180] It should also be understood that terminal devices can also register and join the network using the above method. That is, the terminal device can connect to the mobile relay it wants to connect to through cell selection, and send a registration request message to that mobile relay. The mobile relay then forwards the registration request message to the access network device, which in turn selects an AMF (Active Mobile Provider) for the terminal device and forwards the registration request message to the selected AMF, thus enabling the terminal device to join the network. Correspondingly, the AMF can also assign a temporary ID to the terminal requesting registration and record the correspondence between the terminal device's ID (such as the temporary ID assigned by the AMF), the ID of the connected mobile relay (such as the temporary ID assigned by the AMF mentioned above), and the ID of the access network device.

[0181] Furthermore, if the MT function of the terminal device / mobile relay is undergoing initial network access, meaning that the MT function of the terminal device / mobile relay has not previously successfully registered with the network, then the registration process using the above method can be called the initial registration process. If the MT function of the terminal device / mobile relay has already successfully registered with the network, and due to mobility or periodic registration updates, the MT function is triggered to initiate a registration request again, then this registration process can be called the registration update process. In the former implementation, the registration request message sent by the MT function of the terminal device / mobile relay carries its own permanent identifier, such as the International Mobile Subscriber Identification Number (IMSI). In the latter implementation, the registration request message sent by the MT function of the terminal device / mobile relay carries its own temporary ID, such as the GUTI assigned by the AMF.

[0182] In step 602, the AMF acquires the load of the first mobile trunk and the load of the second mobile trunk.

[0183] As the number of terminal devices connected to each mobile relay increases, each mobile relay can report its own load information to the AMF at preset time intervals. For example, in this embodiment, the first mobile relay and the second mobile relay can report their respective load information to the AMF so that the AMF can determine the load of the first mobile relay and the load of the second mobile relay.

[0184] It should be understood that load can be interpreted as the resources currently occupied by the mobile trunk line. The larger the value, the more resources are currently occupied on the mobile trunk line, indicating that the load of the mobile trunk line is greater.

[0185] It should be understood that the process of each mobile trunk reporting load information to the AMF can be the same. The following text uses the first mobile trunk as an example to explain step 602 in detail. The process of the AMF obtaining the load of the second mobile trunk can also be implemented in the following manner.

[0186] One possible implementation is that the MT function of the first mobile relay can carry the load information in the NAS message and send the NAS message to the AMF through the first access network device.

[0187] That is, step 602 may specifically include step 602a:

[0188] The MT function of the first mobile trunk sends a NAS message to the AMF via the first access network device. This NAS message includes load information. For example, the NAS message may be a registration update message.

[0189] The load information may include information on the resources currently occupied on the mobile relay, information on the remaining resources, or the number of terminal devices connected to the first mobile relay.

[0190] Upon receiving the NAS message, the AMF can obtain the load of the first mobile relay based on the load information carried within it. The specific method by which the AMF obtains the load based on the load information can be found in the relevant description in Method 500 above, and will not be repeated here.

[0191] Optionally, the NAS message may also include the ID of the MT function of the first mobile relay. This allows the first access network device and the AMF to determine which mobile relay is transmitting the load.

[0192] Another possible implementation is that the MT function of the first mobile trunk can send the load information in the RRC message to the first access network device. The first access network device determines the load of the first mobile trunk based on the load information in the received RRC message and sends the load of the first mobile trunk in the N2 message to the AMF.

[0193] That is, step 602 specifically includes step 602b:

[0194] The MT function of the first mobile trunk sends an RRC message to the first access network device. The RRC message includes the load information of the first mobile trunk, which can be the load (e.g., a percentage, decimal, etc. that can be used to represent the load) or the number of terminal devices accessing the first mobile trunk.

[0195] The first access network device sends an N2 message to the AMF, which carries the load of the first mobile trunk or the number of terminal devices accessing the first mobile trunk.

[0196] After receiving the RRC message, the first access network device can determine the load of the first mobile trunk based on the load information carried in the RRC message. For example, if the first mobile trunk reports its load, the AMF can directly obtain the load of the first mobile trunk from the NAS message. If the first mobile trunk reports the number of terminal devices connected to the first mobile trunk, the first access network device can calculate the load of the first mobile trunk itself based on the number of terminal devices connected to the first mobile trunk carried in the NAS message. Of course, the first access network device can also choose not to calculate the load of the first mobile trunk and directly report the number of terminal devices connected to the first mobile trunk to the AMF so that the AMF can calculate the load of the first mobile trunk.

[0197] In addition, the first access network device can determine the ID of the first mobile trunk that sent the RRC message, generate an N2 message based on the load information in the RRC message and the ID of the mobile trunk, and send the N2 message to the AMF.

[0198] It should be noted that each mobile trunk has its own corresponding communication link with the access network device. Furthermore, when establishing this communication link, the mobile trunk exchanges information with the access network device, such as informing the access network device of its own ID. Therefore, even if the RRC message received by the access network device does not carry the mobile trunk's identifier, the access network device can still determine which mobile trunk reported the payload based on the corresponding communication link, and thus obtain the mobile trunk's ID.

[0199] It should be understood that the above-described implementation of the first mobile relay reporting load information is merely an example, and the signaling used to carry the load information is also an example. This application does not impose any limitations on it.

[0200] To facilitate the AMF in more accurately identifying the corresponding second mobile relay for the first mobile relay, optionally, the first and second mobile relays can also report their respective movement trajectories to the AMF. One possible design is that each mobile relay reports its movement trajectory along with its load information in step 602 above. That is, the movement trajectory can be carried in a NAS message or an RRC message.

[0201] Understandably, for buses or trains with fixed routes, the movement trajectories of the mobile relays mounted on them are known and can be pre-configured on the mobile relays. Therefore, these mobile relays can include their movement trajectories in NAS or RRC messages for reporting.

[0202] For mobile relays with unpredictable movement trajectories, it may be impossible to report the movement trajectory in advance. The AMF (Advanced Location Function) can obtain the movement trajectory in the following way: Taking the movement trajectory of the first mobile relay as an example, after receiving the registration request message from the MT (Mobile Transport Function) of the first mobile relay in step 601, the AMF can locate the MT function (i.e., the AMF triggers a location process for the MT function). For example, it can obtain the location information of the MT function at preset time intervals, and thus obtain the corresponding movement trajectory after continuous location for a period of time. If the MT function of the first mobile relay does not report the movement trajectory during the AMF's load acquisition process, the AMF can query the pre-located movement trajectory locally to obtain the movement trajectory of the first mobile relay. Generally speaking, road and railway routes are fixed. When a vehicle is on a certain road or railway, its direction of movement in the future can be basically determined. Therefore, the movement trajectory of the first mobile relay in the future can be predicted based on its current location and its historical movement trajectory. For example, the movement trajectory of the first mobile relay over a future period can be predicted using a network data analytics function (NWDAF). For instance, the AMF can send the current location information and historical movement trajectory of the first mobile relay to the NWDAF. The NWDAF, combining the current location and historical movement trajectory of the first mobile relay, predicts the movement trajectory of the first mobile relay over a future period and sends the predicted trajectory to the AMF.

[0203] It should be understood that the process of AMF acquiring the movement trajectory of the second mobile relay can also be implemented in the same way as above, and will not be elaborated further. It should also be understood that the movement trajectory of the first mobile relay's MT function is the same as the movement trajectory of the first mobile relay. AMF locating the first mobile relay's MT function can be understood as AMF locating the first mobile relay.

[0204] In step 603, the AMF determines that the load of the first mobile relay exceeds a first preset threshold.

[0205] In step 604, the AMF determines that the load of the second mobile relay is lower than the second preset threshold, and that the movement trajectory of the second mobile relay in the first time period is the same as that of the first mobile relay in the first time period.

[0206] It should be understood that the execution process of steps 603 to 604 is the same as the execution process of AMF in steps 501 to 502 above. The specific execution process is the same as that in steps 501 to 502 above, and will not be repeated here.

[0207] In step 605, the AMF sends information about the second mobile relay to the first access network device.

[0208] After the AMF identifies the first and second mobile relays, it can send information about the second mobile relay to the access network equipment. This information can be used to connect terminal equipment to the second mobile relay.

[0209] As one implementation, the AMF can send an N2 message to the first access network device, which carries information about the second mobile trunk. For example, the N2 message could be a UE Context Modification Request message.

[0210] As mentioned above, the information of the second mobile relay can be either the ID of the MT function of the second mobile relay or the cell information of the second mobile relay. For example, the ID of the MT function of the second mobile relay can be the RAN UE NGAP ID, which is assigned by the first access network device to the MT function of the second mobile relay during step 601, and is used by the first access network device to identify the MT function of the second mobile relay. This ID can be used by the first access network device to determine which mobile relay it is. Since the terminal device needs to perform cell reselection based on the cell information of the second mobile relay, if the AMF sends the ID of the second mobile relay to the first access network device, the first access network device can look up the cell information of the second mobile relay from the locally stored correspondence between mobile relays and cell information based on this ID. Further, the AMF can also set a valid duration for controlling the terminal device to migrate to the second mobile relay, for example, denoted as the first duration. Optionally, the method further includes step 606, whereby the AMF sends the first duration to the first access network device.

[0211] One possible design is that the first duration is less than or equal to the duration of the first time period. Since the first and second mobile relays have the same movement trajectory in the first time period, controlling the first duration within the range of the first time period can effectively avoid problems such as frequent cell reselection and reduced transmission performance that might occur if the terminal device is redirected to the second mobile relay even when the second mobile relay is far away from the first mobile relay or has a different movement trajectory.

[0212] The first access network device can start timing after receiving the first duration. As long as the first access network device receives a request from the terminal device to access the network through the first mobile trunk before the first duration expires, it can connect the terminal device to the second mobile trunk.

[0213] It should be understood that the information of the second mobile relay and the first duration can be carried in the same signaling, or they can be carried in different signaling; this application embodiment does not limit this.

[0214] In step 607, the first access network device receives an RRC setup request message from the terminal device.

[0215] For a terminal device in the RRC idle state, the terminal device can send an RRC setup request message to the first access network device via the first mobile trunk. In other words, the terminal device wishes to access the network through the first mobile trunk.

[0216] In step 608, the first access network device determines, based on the first duration, to connect the terminal device to the second mobile relay.

[0217] If the first access network device receives an RRC establishment request message from the terminal device, the first access network device can determine whether the time point received from the first mobile trunk (i.e., the RRC establishment request message sent by the terminal device through the first mobile terminal) still falls within the valid duration of the first time period, or in other words, whether the first time period has not expired. If it has not expired, it can be determined that the terminal device will be connected to the second mobile trunk.

[0218] In step 609, the first access network device sends an RRC rejection message to the terminal device through the first mobile trunk, and the RRC rejection message carries the cell information of the second mobile trunk.

[0219] If the first access network device receives an RRC establishment request message from the terminal device and determines to redirect the terminal device to the second mobile relay, the first access network device sends an RRC reject message to the terminal device. The frequency point of the second mobile relay (i.e., an example of cell information) can be carried in the RRC reject message sent by the first access network device to the terminal device. For example, the redirectedCarrierInfo field in the RRC reject message carries the frequency point of the second mobile relay. This RRC reject message is used to redirect the terminal device to the cell of the frequency point indicated by the redirectedCarrierInfo field, that is, to the cell where the second mobile relay is located.

[0220] It should be understood that the first access network device can not only redirect terminal devices in the RRC idle state to the cell of the second mobile trunk when they request to access the network through the first mobile trunk, but also redirect some terminal devices connected to the first mobile trunk to the second mobile trunk. Figure 6 Although not shown in the image, this should not constitute any limitation on this application.

[0221] For example, for a terminal device in RRC connected state, if the terminal device has already been connected to the first access network device via the first mobile trunk, the first access network device can also determine which terminal devices need to be redirected to the target mobile trunk according to its local policy. In other words, a terminal device in RRC connected state does not necessarily need to send a message to the first access network device, such as the RRC establishment request message in step 607, and can be redirected to the second mobile trunk.

[0222] Correspondingly, in step 609, the first access network device can send an RRC release message to the terminal device. The frequency point of the second mobile relay (i.e., an example of cell information) can be carried, for example, in the RRC release message sent by the first access network device to the terminal device. For instance, the redirectedCarrierInfo field in the RRC release message carries the frequency point of the second mobile relay. This RRC release message is used to redirect the terminal device to the cell containing the frequency point indicated by the redirectedCarrierInfo field, i.e., to the cell where the second mobile relay is located.

[0223] In step 610, the terminal device performs cell reselection.

[0224] Terminal devices that receive cell information from the second mobile relay can perform cell reselection based on the cell information of the second mobile relay, select the cell of the second mobile relay, and enter the network by executing the registration request process.

[0225] In this way, the terminal device can access the network through the second mobile relay, thereby avoiding increasing the load on the first mobile relay.

[0226] Steps 605 to 610 above describe in detail how the AMF controls terminal device access to the second mobile relay at the mobile relay granularity. Regardless of whether the AMF receives a registration request message from the terminal device to access the network through the first mobile relay, it sends the second mobile relay information to the first access network device. During a subsequent period (e.g., a first duration), as long as a terminal device wishes to access the network through the first mobile relay, it can be migrated to the second mobile relay. It should be understood that after the first duration expires, the first mobile relay can still provide relay services between the terminal device and the first access network device.

[0227] It should be noted that in the process exemplified above, after determining that the first mobile relay has a large load and can be load balanced, the AMF can send the information of the second mobile relay to the first access network device. Based on this, the first access network device can connect the terminal device initiating access to the first mobile relay to the second mobile relay. This process controls the connection of terminal devices to the second mobile relay at the mobile relay granularity, achieving load balancing. However, this should not constitute any limitation on this application. The embodiments of this application do not limit the specific implementation method.

[0228] For example, in another implementation, after identifying the second mobile relay, the AMF may temporarily refrain from executing step 605, which involves sending the second mobile relay information to the first access network device. Instead, upon receiving the registration request from the terminal device in step 607 (which should be understood as being sent from the first access network device to the AMF and carrying the identifier of the first mobile relay), the AMF determines that a terminal device requests access from the first mobile relay. Only then does the AMF execute step 605 based on the received registration request, sending the second mobile relay information to the first access network device (e.g., via an N2 message). In other words, step 607 in this process can include: the terminal device sending a registration request message to the first access network device, and the first access network device sending the received registration request message to the AMF. This step 607 can be executed before step 605. Subsequently, the first access network device can determine the information of the second mobile relay based on the received identifier of the second mobile relay, and then directly execute the step of sending the cell information of the second mobile relay to the terminal device in step 609, so as to trigger the terminal device to execute step 610 to perform cell reselection.

[0229] For example, in another implementation, after receiving the load from each mobile trunk, the AMF may temporarily suspend steps 603 to 605. Instead, upon receiving the registration request message from the terminal device in step 607 (which should be understood as being sent from the first access network device to the AMF and carrying the identifier of the first mobile trunk), and determining that a terminal device requests access from the first mobile trunk, the AMF executes steps 603 to 605 based on the received registration request message. This determines that the first mobile trunk is overloaded and that the terminal device accessing the first mobile trunk can be migrated to the second mobile trunk. The AMF then sends information about the second mobile trunk to the first access network device. In other words, step 607 in this process can include: the terminal device sending a registration request message to the first access network device, and the first access network device sending the received registration request message to the AMF. This step 607 can be executed before steps 603, 604, and 605. Subsequently, the first access network device can determine the information of the second mobile relay based on the received identifier of the second mobile relay, and then directly execute the step of sending the cell information of the second mobile relay to the terminal device in step 609, so as to trigger the terminal device to execute step 610 to perform cell reselection.

[0230] As can be seen, in the other two implementations provided above, the first access network device obtains the information of the second mobile trunk from the AMF and connects the terminal device to the second mobile trunk only after determining that a terminal device requests access from the first mobile trunk and sending the terminal device's registration request message to the AMF. This process controls the terminal device's access to the second mobile trunk at the terminal device level, achieving load balancing. Therefore, the AMF does not need to send the first duration to the first access network device; that is, step 606 can be omitted.

[0231] It should be understood that Figure 6 This is merely an example illustrating the process of controlling terminal devices to access a second mobile relay at the relay node level. This application does not limit the specific implementation methods or the order in which the steps are executed.

[0232] Based on the above scheme, the AMF (Advanced Mobile Network Function) identifies mobile trunks with excessive loads and those with less loads. Furthermore, from among the less loaded mobile trunks, those with the same movement trajectory as the excessively loaded ones within the same time period are selected as target mobile trunks. This allows terminal devices to migrate from the excessively loaded mobile trunks to the less loaded ones, achieving load balancing among the mobile trunks. By achieving load balancing among mobile trunks, the pressure on individual excessively loaded mobile trunks can be alleviated, transferring some of the pressure to less loaded ones. This improves mobile trunk performance and reduces the deployment requirements of wired transmission networks, especially in areas where wired transmission networks are difficult to deploy, such as indoors, thus increasing system throughput. In addition, considering the high mobility of mobile trunks, the core network equipment determines the target mobile trunk for the first mobile trunk based on the movement trajectory of each mobile trunk. Since the movement trajectory of the second mobile relay selected as the target mobile relay is the same as that of the first mobile relay for a period of time (such as the first time period mentioned above), if some terminal devices are migrated from the first mobile relay to the second mobile relay, the service connections of the terminal devices can be unaffected by the mobility of the second mobile relay during the first time period. This avoids the frequent cell reselection of these terminal devices due to the location change of the second mobile relay, thereby avoiding the increase in signaling overhead and power consumption caused by cell reselection, reducing the impact on the normal communication of the terminal devices, and helping to ensure the transmission performance of the terminal devices.

[0233] Figure 7 This is a schematic flowchart applicable to a communication method provided in another embodiment of this application.

[0234] It should be noted that method 700 is applicable to Figure 4 The illustration shows a scenario where a terminal device migrates between mobile trunks connected to different access network devices. In this case, the first mobile trunk and the second mobile trunk are connected to different access network devices, with the first mobile trunk connected to the first access network device and the second mobile trunk connected to the second access network device.

[0235] It should be understood that, for ease of understanding and illustration, Figure 7 The diagram only shows a first access network device and a second access network device connected to the same AMF, a first mobile trunk connected to the first access network device, a second mobile trunk connected to the second access network device, and the first and second access network devices themselves. In practical applications, the first and second access network devices can each connect to more mobile trunks, and the AMF can also connect to more access network devices.

[0236] In step 701, the first mobile relay and the second mobile relay register with the network.

[0237] The execution process of step 701 is the same as that of step 601. For details of the execution process, please refer to the above description of step 601.

[0238] The difference between step 701 and step 601 is that in step 701, the first mobile trunk initiates a registration request to the first access network device, and the second mobile trunk initiates a registration request to the second access network device. In step 601, however, the first and second mobile trunks initiate registration requests to the same access network device.

[0239] In step 702, the AMF acquires the load of the first mobile trunk and the load of the second mobile trunk.

[0240] The specific implementation of step 702 is the same as that of step 602 mentioned above. For details, please refer to the above description of steps 601 to 602, which will not be repeated here.

[0241] Similarly, taking the first mobile trunk as an example. In one possible implementation, the MT function of the first mobile trunk can carry load information in a NAS message and send the NAS message to the AMF through the first access network device.

[0242] That is, step 702 may specifically include step 702a:

[0243] The MT function of the first mobile relay sends a NAS message to the AMF via the first access network device. The NAS message includes load information, which may include information on the resources currently occupied on the mobile relay, information on the remaining resources, or the number of terminal devices accessing the first mobile relay.

[0244] Another possible implementation is that the MT function of the first mobile trunk can send the load information in the RRC message to the first access network device. The first access network device determines the load of the first mobile trunk based on the load information in the received RRC message and sends the load of the first mobile trunk in the N2 message to the AMF.

[0245] That is, step 702 may specifically include step 702b:

[0246] The MT function of the first mobile trunk sends an RRC message to the first access network device. The RRC message includes load information, which may include information on the resources currently occupied on the mobile trunk, information on the remaining resources, or the number of terminal devices accessing the first mobile trunk. The load information can be used by the first access network device to determine the load of the first mobile trunk.

[0247] The first access network device sends an N2 message to the AMF, which carries the load of the first mobile trunk or the number of terminal devices accessing the first mobile trunk.

[0248] It should be understood that the implementation method of the first mobile trunk reporting load information listed above is only an example. The implementation method of the second mobile trunk reporting load information is the same as step 702a or step 702b. It only requires the second mobile trunk to report the load to the second access network device, and then the second access network device to report the load to the AMF.

[0249] It should also be understood that the specific implementation method for obtaining load based on load information can be found in the relevant description in Method 500 above, and will not be repeated here.

[0250] In step 703, the AMF determines that the load of the first mobile relay exceeds a first preset threshold.

[0251] In step 704, the AMF determines that the load of the second mobile relay is lower than the second preset threshold, and that the movement trajectory of the second mobile relay in the first time period is the same as that of the first mobile relay in the first time period.

[0252] The execution process of steps 703 to 704 is the same as that of steps 603 to 604. For details, please refer to the above description of steps 603 to 604.

[0253] In step 705, the AMF sends information about the second mobile relay to the first access network device.

[0254] Since the first mobile trunk and the second mobile trunk are connected to different access network devices, if the terminal device is to access the second mobile trunk, the AMF or the first access network device also needs to obtain the cell information of the second mobile trunk so that the terminal device can perform cell reselection.

[0255] In one possible implementation, the AMF can obtain the cell information of the second mobile trunk from the second access network device, and then send the cell information of the second mobile trunk to the first access network device. That is, the information of the second mobile trunk is the cell information of the second mobile trunk. Figure 7 705a in the document illustrates the various steps in this implementation:

[0256] AMF sends the ID of the second mobile trunk to the second access network device;

[0257] The second access network device sends the cell information of the second mobile trunk to the AMF based on the ID of the second mobile trunk; and

[0258] AMF sends the cell information of the second mobile relay to the first access network device.

[0259] For example, when the MT function of the second mobile trunk enters the network through the second access network device, the AMF can save the correspondence between the second mobile trunk and the second access network device. For instance, it can record the correspondence between the temporary ID of the MT function of the second mobile trunk (as mentioned earlier, this temporary ID can be assigned by the AMF when the second mobile trunk enters the network) and the ID of the second access network device. After determining that the second mobile trunk will be used as the target mobile trunk of the first mobile trunk, the AMF can send a request message to the second access network device according to this correspondence to request the cell information of the second mobile trunk. For example, the request message may include: the ID of the second mobile trunk, the request message is used to request the terminal device to access the second mobile trunk, and the request is used to obtain the cell information of the second mobile trunk.

[0260] Upon receiving the request message, if the second access network device agrees to the access of the terminal device, it can determine the cell information of the second mobile relay based on the ID of the second mobile relay and send a response message to the AMF. The response message includes the cell information of the second mobile relay.

[0261] After receiving the response message, AMF can send the cell information of the second mobile relay to the first access network device corresponding to the first mobile relay, based on the correspondence between the first mobile relay and the first access network device.

[0262] Furthermore, the AMF can further determine the effective duration for which the control terminal device migrates to the second mobile relay, i.e., the first duration, and send the first duration to the first access network device. For example, the first duration can be less than or equal to the duration of the first time period.

[0263] It should be understood that the cell information and first duration of the second mobile relay can be carried in one N2 message or in different N2 messages. This application does not limit this.

[0264] The correspondence between the first mobile trunk and the first access network device is similar to the correspondence between the second mobile trunk and the second access network device in the example above. It can be saved when the MT function of the first mobile trunk enters the network through the first access network device. For example, it can be the correspondence between the temporary ID of the MT function of the first mobile trunk and the ID of the second access network device.

[0265] In another possible implementation, the AMF can send the ID of the second mobile trunk to the first access network device, which can then obtain the cell information of the second mobile trunk from the second access network device via the Xn interface.

[0266] Figure 7 705b in the document illustrates the various steps in this implementation:

[0267] AMF sends the ID of the second mobile trunk and the ID of the second access network device to the first access network device;

[0268] The first access network device sends a request message to the second access network device, the request message being used to obtain the cell information of the second mobile trunk;

[0269] The second access network device sends the cell information of the second mobile trunk to the first access network device.

[0270] Specifically, the AMF can first send an N2 message to the first access network device. The N2 message includes: the identifier of the second mobile trunk and the identifier of the second access network device. The identifier of the second mobile trunk is used to indicate that the terminal device is connected to the second mobile trunk, and the identifier of the second access network device is used to indicate that the second mobile trunk is connected to the second access network device.

[0271] Optionally, the N2 message may also include a first duration to allow the first access network device to control the terminal device to migrate to the second mobile trunk within a reasonable time frame.

[0272] It should be understood that the cell information and first duration of the second mobile relay can be carried in one N2 message or in different N2 messages. This application does not limit this.

[0273] The first access network device can send a request message to the second access network device through the Xn interface based on the identifier of the second access network device. The request message includes the identifier of the second mobile trunk for obtaining the cell information of the second mobile trunk.

[0274] After receiving the request message, the second access network device determines the cell information of the second mobile trunk based on the identifier of the second mobile trunk, and sends a response message to the first access network device through the Xn interface. The response message includes the cell information of the second mobile trunk.

[0275] Optionally, the request message sent to the second access network device in the above two implementation methods may also carry a request reason, which can be used to indicate that the first mobile trunk is overloaded.

[0276] In step 706, the first access network device receives an RRC establishment request message from a terminal device in an RRC idle state. In step 707, the first access network device determines, based on a first duration, to connect the terminal device to the second mobile trunk.

[0277] Similar to method 600, the first access network device can determine whether the first moment (e.g., denoted as the first moment) and the first duration fall within the effective duration of the first duration, or in other words, whether the first duration has not expired, based on the time point (e.g., the first moment) at which it receives the RRC establishment request message from the terminal device in the RRC idle state. If the first duration has not expired, then it is determined to connect the terminal device to the second mobile trunk.

[0278] In step 708, the first access network device sends an RRC rejection message to the terminal device through the first mobile trunk, and the RRC rejection message carries the cell information of the second mobile trunk.

[0279] In step 709, the terminal device performs cell reselection, selects the cell of the second mobile relay, and executes the registration request process.

[0280] The specific implementation methods of steps 706 to 709 are the same as those of steps 607 to 610 mentioned above. For details, please refer to the above description of steps 607 to 610, which will not be repeated here.

[0281] It should be understood that, similar to method 600, the above method is not limited to controlling terminal devices in the RRC idle state to access the second mobile trunk. For terminal devices in the RRC connected state, the first access network device can also redirect some terminal devices connected to the first mobile trunk to the second mobile trunk. Correspondingly, the RRC rejection message in step 708 can be replaced with an RRC release message.

[0282] It should be noted that in the process illustrated above, after determining that the first mobile relay has a large load and can be load balanced, the AMF can send the information of the second mobile relay to the first access network device or the second access network device. After obtaining the identifier of the second mobile relay, the first access network device can connect the terminal device initiating access to the first mobile relay to the second mobile relay. In this process, the step of the first access network device determining the second mobile relay does not require the access of the terminal device to trigger it; it controls the terminal device to access the second mobile relay at the mobile relay granularity, thus achieving load balancing. However, this should not constitute any limitation on this application. The embodiments of this application do not limit the specific implementation method.

[0283] For example, in another implementation, after identifying the second mobile relay, the AMF can temporarily postpone step 705. Instead, after receiving the registration request message from the terminal device in step 706 (which should be understood as being sent from the first access network device to the AMF and carrying the identifier of the first mobile relay), the AMF determines that a terminal device requests access from the first mobile relay. Only then does the AMF execute step 705 based on the received registration request message. In other words, step 706 in this process can include: the terminal device sending a registration request message to the first access network device, and the first access network device sending the received registration request message to the AMF. This step 706 can be executed before step 705. Subsequently, the first access network device can determine the information of the second mobile relay based on the received identifier of the second mobile relay, and then directly execute the step of sending the cell information of the second mobile relay to the terminal device in step 708 to trigger the terminal device to execute step 709 for cell reselection.

[0284] For example, in another implementation, after receiving the load from each mobile trunk, the AMF may temporarily suspend steps 603 to 605. Instead, upon receiving the registration request message from the terminal device in step 706 (which should be understood as being sent from the first access network device to the AMF and carrying the identifier of the first mobile trunk), and determining that a terminal device requests access from the first mobile trunk, the AMF executes steps 703 to 705 based on the received registration request. It then determines that the first mobile trunk is overloaded and that the terminal device accessing the first mobile trunk can be migrated to the second mobile trunk, and sends the second mobile trunk information to the first access network device. In other words, step 706 in this process may include: the terminal device sending a registration request message to the first access network device, and the first access network device sending the received registration request message to the AMF. This step 706 can be executed before steps 703, 704, and 705. Subsequently, the first access network device can determine the information of the second mobile relay based on the received identifier of the second mobile relay, and then directly execute the step of sending the cell information of the second mobile relay to the terminal device in step 708, so as to trigger the terminal device to execute step 709 to perform cell reselection.

[0285] As can be seen, in the other two implementations provided above, the first access network device obtains the information of the second mobile trunk only after determining that a terminal device requests access from the first mobile trunk and after sending the terminal device's registration request message to the AMF, and then connects the terminal device to the second mobile trunk. This process controls the terminal device's access to the second mobile trunk at the terminal device level, thereby achieving load balancing.

[0286] It should be understood that Figure 7This is merely an example illustrating the process of controlling terminal devices to access a second mobile relay at the relay node level. This application does not limit the specific implementation methods or the order in which the steps are executed.

[0287] Based on the above scheme, the AMF (Advanced Mobile Network Function) identifies mobile trunks with excessive loads and those with less loads. Furthermore, from among the less loaded mobile trunks, those with the same movement trajectory as the excessively loaded ones within the same time period are selected as target mobile trunks. This allows terminal devices to migrate from the excessively loaded mobile trunks to the less loaded ones, achieving load balancing among the mobile trunks. By achieving load balancing among mobile trunks, the pressure on individual excessively loaded mobile trunks can be alleviated, transferring some of the pressure to less loaded ones. This improves mobile trunk performance and reduces the deployment requirements of wired transmission networks, especially in areas where wired transmission networks are difficult to deploy, such as indoors, thus increasing system throughput. In addition, considering the high mobility of mobile trunks, the core network equipment determines the target mobile trunk for the first mobile trunk based on the movement trajectory of each mobile trunk. Since the movement trajectory of the second mobile relay selected as the target mobile relay is the same as that of the first mobile relay for a period of time (such as the first time period mentioned above), if some terminal devices are migrated from the first mobile relay to the second mobile relay, the service connections of the terminal devices can be unaffected by the mobility of the second mobile relay during the first time period. This avoids the frequent cell reselection of these terminal devices due to the location change of the second mobile relay, thereby avoiding the increase in signaling overhead and power consumption caused by cell reselection, reducing the impact on the normal communication of the terminal devices, and helping to ensure the transmission performance of the terminal devices.

[0288] The above text combined Figure 6 and Figure 7 The communication method implemented under AMF control is described below. Figure 8 Describe the communication method implemented under the control of access network equipment.

[0289] Figure 8 This is a schematic flowchart applicable to a communication method provided in another embodiment of this application.

[0290] It should be noted that Method 800 is applicable to Figure 3 The illustration shows a scenario where the terminal device migrates between mobile trunks within the same access network device. In this case, the first mobile trunk and the second mobile trunk are connected to the same access network device, namely the first access network device.

[0291] It should be understood that, for ease of understanding and illustration, Figure 8The diagram only shows the first access network device connected to the AMF, and the first and second mobile trunks connected to the first access network device. In practical applications, the first access network device can also connect to more mobile trunks, and the AMF can also connect to more access network devices.

[0292] The following details each step in method 800.

[0293] In step 801, the first mobile relay and the second mobile relay register with the network.

[0294] Each mobile trunk, including the first mobile trunk and the second mobile trunk, can initiate a registration process through this access network device to join the network.

[0295] It should be understood that the execution process of step 801 is the same as step 601 in method 600. For details, please refer to the relevant explanation in step 601 above, which will not be repeated here.

[0296] In step 802, the first access network device acquires the load of the first mobile trunk and the load of the second mobile trunk.

[0297] As the number of terminal devices accessing each mobile relay increases, each mobile relay connected to the first access network device can report its own load information to the first access network device at preset time intervals. As mentioned earlier, the load information may include information on the resources currently occupied on the mobile relay, information on the remaining resources, or the number of terminal devices connected to each mobile relay. For the specific implementation of obtaining the load based on the load information, please refer to the relevant description in method 500, which will not be repeated here.

[0298] The following provides two possible implementations for the first access network device to obtain the load of each mobile trunk. In one implementation, the MT function of each mobile trunk can send load information in an RRC message to the first access network device, which then determines the load of each mobile trunk based on the load information in the received RRC message.

[0299] As another implementation, the DU function of each mobile trunk can carry load information in the F1 setup request message and send it to the first access network device. The first access network device determines the load of each mobile trunk based on the load information in the received F1 setup request message.

[0300] For buses or trains with fixed routes, the movement trajectories of the mobile relays on board are known and can be pre-configured on the mobile relays. Therefore, in step 802, the MT function of each mobile relay can also send the movement trajectory information to the first access network device in an RRC message, or the DU function of each mobile relay can send the movement trajectory information to the first access network device in an F1 setup request message.

[0301] Furthermore, when determining the target mobile relay (i.e., the second mobile relay) for the first mobile relay, the first access network device needs to combine the movement trajectory of the first mobile relay to determine the second mobile relay. If each mobile relay actively reports its movement trajectory in step 802, the access network device can directly determine the second mobile relay based on the load and movement trajectory of each mobile relay. If the mobile relay does not actively report its movement trajectory in step 802, the method further includes step 803: obtaining the movement trajectory of each mobile relay.

[0302] For example, step 803 may specifically include:

[0303] The first access network device sends a trajectory acquisition request to the AMF, which carries the ID of each mobile trunk;

[0304] The access network equipment receives the movement trajectories of each mobile relay.

[0305] It should be understood that the first access network device can request the movement trajectories of each mobile trunk it is connected to from the AMF in order to find a second mobile trunk whose movement trajectories are the same as those of the first mobile trunk within a certain time period. The specific method by which the AMF obtains the movement trajectories of each mobile trunk is described in detail in method 600 above, and will not be repeated here.

[0306] In step 804, the first access network device determines that the load of the first mobile trunk exceeds a first preset threshold.

[0307] In step 805, the first access network device determines that the load of the second mobile relay is lower than the second preset threshold, and that the movement trajectory of the second mobile relay in the first time period is the same as that of the first mobile relay in the first time period.

[0308] It should be understood that the execution process of steps 804 to 805 is the same as that of steps 510 to 520 in method 500. For details, please refer to the relevant explanations of steps 510 to 520 above, which will not be repeated here.

[0309] Furthermore, similar to method 600, when the first access network device implements load balancing at the mobile relay level, a valid duration, such as a first duration, can be set for the second mobile relay after it is identified. This allows control over terminal devices accessing the network via the first mobile relay to connect to the second mobile relay within that first duration.

[0310] In step 806, the first access network device receives an RRC establishment request message from a terminal device in the RRC idle state.

[0311] For a terminal device in RRC idle state, the terminal device sends an RRC establishment request message to the first access network device via the first mobile trunk. That is, the terminal device wishes to access the network through the first mobile trunk.

[0312] If the first access network device implements load balancing at the mobile relay level, the method may further include step 807, whereby the first access network device determines to connect the terminal device to the second mobile relay based on a first duration. As mentioned above, if the first access network device receives an RRC establishment request message from the terminal device, the first access network device can determine whether the time point received from the first mobile relay still falls within the valid duration of the first duration, or in other words, whether the first duration has not expired, based on the first duration and the time point of receiving the RRC message from the first mobile relay. If it has not expired, then it can be determined to connect the terminal device to the second mobile relay.

[0313] In step 808, the first access network device sends an RRC rejection message to the terminal device through the first mobile trunk, and the RRC rejection message carries the cell information of the second mobile trunk.

[0314] In step 809, the terminal device performs cell reselection, selects the cell of the second mobile relay, and executes the registration request process.

[0315] It should be understood that the execution process of steps 806 to 809 is the same as that of steps 607 to 610 in method 600. Please refer to the relevant description of steps 609 to 610 above, which will not be repeated here.

[0316] It should be understood that, similar to method 600, the above method is not limited to controlling terminal devices in the RRC idle state to access the second mobile trunk. For terminal devices in the RRC connected state, the first access network device can also redirect some terminal devices connected to the first mobile trunk to the second mobile trunk. Correspondingly, the RRC rejection message in step 808 can be replaced with an RRC release message.

[0317] It should be noted that in the process illustrated above, after determining that the first mobile relay has a large load and can be load balanced, the first access network device can then determine the second mobile relay. Based on this, the first access network device can connect the terminal device initiating access to the first mobile relay to the second mobile relay. In this process, the step of the first access network device determining the second mobile relay does not require the access of the terminal device to trigger it. It controls the terminal device to access the second mobile relay at the mobile relay level, achieving load balancing. However, this should not constitute any limitation on this application. The embodiments of this application do not limit the specific implementation method.

[0318] For example, in another implementation, after receiving the load from each mobile trunk, the first access network device may temporarily suspend steps 804 and 805. Instead, upon receiving the RRC establishment request message from the terminal device in the RRC idle state in step 806, and confirming that a terminal device requests access from the first mobile trunk, it executes steps 804 and 805 based on the received RRC establishment request message. It then determines that the first mobile trunk is overloaded and that the terminal device accessing the first mobile trunk can be migrated to the second mobile trunk, and sends the second mobile trunk information to the first access network device. In other words, step 806 can be executed before steps 804 and 805. Afterward, the first access network device can execute step 808, sending the cell information of the second mobile trunk to the terminal device, to trigger the terminal device to execute step 709 for cell reselection.

[0319] As can be seen, in the alternative implementation provided above, the first access network device only identifies the second mobile trunk and connects the terminal device to the second mobile trunk after determining that a terminal device requests access from the first mobile trunk. This process controls the terminal device's access to the second mobile trunk at the terminal device level, achieving load balancing. Therefore, the first access network device does not need to determine whether to connect the terminal device to the second mobile trunk based on the first duration; that is, step 807 can be omitted.

[0320] It should be understood that Figure 8 This is merely an example illustrating the process of controlling a terminal device to access a second mobile relay at the mobile relay level. This application does not limit the specific implementation methods or the order in which the steps are executed.

[0321] Based on the above scheme, the access network equipment identifies mobile trunks with excessive loads and those with less loads. From the less loaded mobile trunks, it identifies those with the same movement trajectory as the excessively loaded ones within the same time period, designating them as target mobile trunks. This controls the migration of terminal devices from the excessively loaded mobile trunks to the less loaded ones, achieving load balancing among the mobile trunks. By achieving load balancing among mobile trunks, the pressure on some excessively loaded mobile trunks can be alleviated, transferring some of the pressure to less loaded ones, which is beneficial for improving mobile trunk performance and reducing the deployment requirements of wired transmission networks. This is particularly beneficial for improving system throughput in areas where wired transmission networks are difficult to deploy, such as indoors. Furthermore, considering the high mobility of mobile trunks, the first access network equipment determines the target mobile trunk for the first mobile trunk based on the movement trajectory of each mobile trunk. Since the movement trajectory of the second mobile relay selected as the target mobile relay is the same as that of the first mobile relay for a period of time (such as the first time period mentioned above), if some terminal devices are migrated from the first mobile relay to the second mobile relay, the service connections of the terminal devices can be unaffected by the mobility of the second mobile relay during the first time period. This avoids the frequent cell reselection of these terminal devices due to the location change of the second mobile relay, thereby avoiding the increase in signaling overhead and power consumption caused by cell reselection, reducing the impact on the normal communication of the terminal devices, and helping to ensure the transmission performance of the terminal devices.

[0322] The above, combined with Figures 3 to 8 The methods provided in the embodiments of this application are described in detail below. Hereinafter, in conjunction with... Figures 9 to 11 The apparatus provided in the embodiments of this application will be described in detail.

[0323] Figure 9 This is a schematic block diagram of a communication device provided in an embodiment of this application. Figure 9 As shown, the communication device 900 includes a processing unit 910 and a transceiver unit 920.

[0324] Optionally, the communication device 900 may correspond to the AMF (an example of a core network device) in the method embodiments. For example, the communication device 900 may be an AMF, or it may be a component configured in the AMF (such as a circuit, chip, chip system, etc.), or it may be a logic module or software capable of implementing all or part of the AMF functions. This application embodiment does not limit this.

[0325] When the communication device 900 corresponds to the AMF, the communication device 900 can be used to perform the above-mentioned combination. Figures 5 to 8 The AMF performs the steps in methods 500 to 800 shown, and the communication device 900 may include steps for performing the above. Figures 5 to 8The units in methods 500 to 800 shown are units that execute the method of AMF. Furthermore, each unit in the communication device 900 and the other operations and / or functions described above are respectively for implementing... Figures 5 to 8 The corresponding processes in methods 500 to 800 are shown.

[0326] It should be understood that when the communication device is an AMF, the transceiver unit 920 in the communication device 900 can be implemented by a transceiver, for example, it can correspond to... Figure 10 The transceiver is shown in the communication device 1000. The processing unit 910 in the communication device 900 can be implemented by at least one processor, for example, corresponding to... Figure 10 The processor 1010 in the communication device 1000 shown in the figure.

[0327] Optionally, the communication device 900 may correspond to the first access network device in the method embodiment. For example, the communication device 900 may be the first access network device, or it may be a component (such as a circuit, chip, chip system, etc.) configured in the first access network device, or it may be a logic module or software capable of implementing all or part of the AMF function. This application embodiment does not limit this.

[0328] When the communication device 900 corresponds to the first access network device, the communication device 900 can be used to perform the above-mentioned combination. Figures 5 to 8 The communication device 900 may include steps performed by the first access network device in methods 500 to 800 shown above, and may include methods for performing the above steps. Figures 5 to 8 The units of the method executed by the first access network device in methods 500 to 800 shown are respectively for implementing... Furthermore, each unit in the communication device 900 and the other operations and / or functions described above are respectively for implementing... Figures 5 to 8 The corresponding processes in methods 500 to 800 are shown.

[0329] It should be understood that when the communication device is a first access network device, the transceiver unit 920 in the communication device 900 can be implemented by a transceiver, for example, it can correspond to... Figure 10 The transceiver or transceiver in the communication device 1000 shown in the figure Figure 11 The remote radio unit (RRU) 2100 in the base station 2000 is shown in the diagram. The processing unit 910 in the communication device 900 can be implemented by at least one processor, for example, corresponding to… Figure 10 The processor 1010 or in the communication device 1000 shown in the figure Figure 11 The processing unit 2200 or processor 2202 in the base station 2000 shown in the figure.

[0330] Optionally, the communication device 900 may correspond to the second access network device in the method embodiment. For example, the communication device 900 may be the second access network device, or it may be a component (such as a circuit, chip, chip system, etc.) configured in the second access network device, or it may be a logic module or software capable of implementing all or part of the AMF function. This application embodiment does not limit this.

[0331] When the communication device 900 corresponds to the second access network device, the communication device 900 can be used to perform the above-mentioned combination. Figure 7 The steps performed by the second access network device in the method 700 shown above, the communication device 900 may include steps for performing the above. Figure 7 The method 700 shown is a unit of the method executed by the second access network device. Furthermore, each unit in the communication device 900 and the other operations and / or functions described above are respectively for implementing... Figure 7 The corresponding process in method 700 is shown.

[0332] It should be understood that when the communication device is a second access network device, the transceiver unit 920 in the communication device 900 can be implemented by a transceiver, for example, it can correspond to... Figure 10 The transceiver or transceiver in the communication device 1000 shown in the figure Figure 11 The base station 2000 shown in the figure has an RRU 2100. The processing unit 910 in the communication device 900 can be implemented by at least one processor, for example, which can correspond to Figure 10 The processor 1010 or in the communication device 1000 shown in the figure Figure 11 The processing unit 2200 or processor 2202 in the base station 2000 shown in the figure.

[0333] It should also be understood that when the communication device 900 is a chip or chip system configured in the AMF, the first access network equipment or the second access network, the transceiver unit 920 in the communication device 900 can be implemented through input / output interfaces, circuits, etc., and the processing unit 910 in the communication device 900 can be implemented through a processor, microprocessor or integrated circuit integrated on the chip or chip system.

[0334] Figure 10 This is another schematic block diagram of the communication device provided in the embodiments of this application. For example... Figure 10 As shown, the device 1000 may include at least one processor 1010. The at least one processor 1010 may be used to implement the functions of the AMF (an example of a core network device) or access network device in the methods provided in the embodiments of this application.

[0335] For example, when the device 1000 is used to implement the AMF function in the method provided in the embodiments of this application, the processor 1010 can be used to determine that the load of the first mobile relay exceeds a first preset threshold; determine that the load of the second mobile relay is lower than a second preset threshold, and determine that the movement trajectory of the second mobile relay in a first time period is the same as the movement trajectory of the first mobile relay in the first time period; and control the communication interface 1030 to send the information of the second mobile relay to the first access network device; wherein, the information of the second mobile relay is used to connect the terminal device to the second mobile relay, the first mobile relay and the second mobile relay are in a mobile state, and the first mobile relay is used to provide relay services between the terminal device and the first access network device.

[0336] When the device 1000 is used to implement the function of the first access network device in the method provided in this application embodiment, the processor 1010 can be used to determine that the load of the first mobile relay exceeds a first preset threshold; determine that the load of the second mobile relay is lower than a second preset threshold, and determine that the movement trajectory of the second mobile relay in a first time period is the same as the movement trajectory of the first mobile relay in the first time period; determine that the terminal device requests access from the first mobile relay at a first moment in the first time period; and control the communication interface 1030 to send the frequency point of the second mobile relay to the terminal device, the frequency point of the second mobile relay being used by the terminal device to access the second mobile relay. See the detailed description in the method examples for details, which will not be repeated here.

[0337] The device 1000 may further include at least one memory 1020 for storing program instructions and / or data. The memory 1020 is coupled to the processor 1010. The coupling in this embodiment is an indirect coupling or communication connection between devices, units, or modules, and may be electrical, mechanical, or other forms, used for information exchange between devices, units, or modules. The processor 1010 may operate in conjunction with the memory 1020. The processor 1010 may execute program instructions stored in the memory 1020. At least one of the at least one memory may be included in the processor.

[0338] The device 1000 may further include a communication interface 1030 for communicating with other devices via a transmission medium, thereby enabling the device 1000 to communicate with other devices. For example, when the device 1000 is used to implement the AMF function in the method provided in this application embodiment, the other device may be a first access network device, a second access network device, etc.; when the device 1000 is used to implement the access network device function in the method provided in this application embodiment, the other device may be a terminal device, an AMF, etc. The communication interface 1030 may be, for example, a transceiver, an interface, a bus, a circuit, or a device capable of transmitting and receiving functions. The processor 1010 may utilize the communication interface 1030 to transmit and receive data and / or information, and to implement... Figures 5 to 8 The method performed by the AMF or access network device in the corresponding embodiment.

[0339] This application embodiment does not limit the specific connection medium between the processor 1010, memory 1020, and communication interface 1030. This application embodiment... Figure 10 The processor 1010, memory 1020, and communication interface 1030 are connected via bus 1040. Bus 1040 is... Figure 10 The connections between other components are shown in thick lines only and are not intended to be limiting. This bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, Figure 10 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0340] Figure 11 This is a schematic diagram of the access network device provided in an embodiment of this application. The network device can be, for example, a base station. The base station 2000 can be applied to, for example... Figure 1 In the scenario shown, the functions of the first access network device or the second access network device in the above method embodiments are performed.

[0341] like Figure 11 As shown, the base station 2000 may include one or more radio frequency units, such as a remote radio frequency unit (RRU) 2010 and one or more baseband units (BBU) (also known as distributed units (DU)) 2020. The RRU 2010 can be referred to as a transceiver unit and can interact with... Figure 9 The transceiver unit 920 or Figure 10The communication interface 1030 corresponds to this. Optionally, the RRU 2100 can also be called a transceiver, transceiver circuit, or transceiver unit, etc., and it may include at least one antenna 2101 and a radio frequency unit 2102. Optionally, the RRU 2100 may include a receiving unit and a transmitting unit. The receiving unit may correspond to a receiver (or receiver circuit), and the transmitting unit may correspond to a transmitter (or transmitter circuit). The RRU 2100 is mainly used for transmitting and receiving radio frequency signals and converting radio frequency signals to baseband signals. For example, it is used to execute the operation procedures of the first access network device or the second access network device, such as executing the operation procedures of the first access network device sending RRC rejection messages and RRC release messages to the terminal device. The BBU 2200 is mainly used for baseband processing and controlling the base station. The RRU 2100 and BBU 2200 can be physically set together or physically separated, i.e., a distributed base station.

[0342] The BBU 2200 is the control center of the base station, also known as the processing unit, and can communicate with... Figure 9 Processing unit 910 or Figure 10 The processor 1010 in the diagram is mainly used to complete baseband processing functions, such as channel coding, multiplexing, modulation, spreading, etc. For example, the BBU (processing unit) can be used to control the base station to execute the operation procedures of the first access network device or the second access network device in the above method embodiments, such as executing the operation procedures of the first access network device to determine whether the first duration has expired and whether to connect the terminal device to the first mobile relay.

[0343] In one example, the BBU 2200 can be composed of one or more single boards. Multiple single boards can collectively support a single access standard wireless access network (such as an LTE network), or they can each support different access standard wireless access networks (such as LTE, 5G, or other networks). The BBU 2200 also includes a memory 2201 and a processor 2202. The memory 2201 is used to store necessary instructions and data. The processor 2202 is used to control the base station to perform necessary actions, such as controlling the base station to execute the operation procedures related to the network device in the above method embodiments. The memory 2201 and processor 2202 can serve one or more single boards. That is, each single board can have its own memory and processor, or multiple single boards can share the same memory and processor. Furthermore, each single board can also have necessary circuitry.

[0344] It should be understood that Figure 11 The base station 2000 shown can achieve Figures 5 to 8The methods illustrated in the embodiments involve various processes of the first access network device. The operations and / or functions of each module in the base station 2000 are respectively for implementing the corresponding processes in the above method embodiments. For details, please refer to the descriptions in the above method embodiments; to avoid repetition, detailed descriptions are appropriately omitted here.

[0345] The BBU 2200 described above can be used to perform the actions implemented internally by the first access network device as described in the preceding method embodiments, while the RRU 2100 can be used to perform the actions sent by the first access network device to the terminal device or received from the terminal device as described in the preceding method embodiments. Please refer to the descriptions in the preceding method embodiments for details, which will not be repeated here.

[0346] or, Figure 11 The base station 2000 shown can achieve Figure 7 The methods described in the embodiment illustrate the various processes of the second access network device. The operations and / or functions of each module in the base station 2000 are respectively for implementing the corresponding processes in the above method embodiments. For details, please refer to the descriptions in the above method embodiments; to avoid repetition, detailed descriptions are appropriately omitted here.

[0347] The BBU 2200 described above can be used to perform the actions implemented internally by the second access network device as described in the preceding method embodiments, while the RRU 2100 can be used to perform the actions described in the preceding method embodiments, whereby the second access network device sends or receives data from the AMF or the first access network device. For details, please refer to the descriptions in the preceding method embodiments; they will not be repeated here.

[0348] It should be understood that Figure 11 The base station 2000 shown is only one possible form of access network equipment and should not be construed as limiting this application. The method provided in this application can be applied to other forms of access network equipment. For example, it may include an AAU, and may also include a CU and / or a DU, or include a BBU and an adaptive radio unit (ARU), or a BBU; it may also be customer premises equipment (CPE), or other forms. This application does not limit the specific form of the network equipment.

[0349] The CU and / or DU can be used to perform the actions implemented internally by the access network device as described in the preceding method embodiments, while the AAU can be used to perform the actions sent by the access network device to the terminal device or received from the terminal device as described in the preceding method embodiments. Please refer to the descriptions in the preceding method embodiments for details, which will not be repeated here.

[0350] It should be understood that the processor in this application can be an integrated circuit chip with signal processing capabilities. In implementation, the steps of the above method embodiments can be completed by the integrated logic circuits in the processor's hardware or by instructions in software form. The processor can 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 devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in memory, and the processor reads the information in the memory and, in conjunction with its hardware, completes the steps of the above method.

[0351] It should also be understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0352] This application also provides a computer program product comprising: a computer program (also referred to as code or instructions), which, when executed, causes a computer to perform... Figures 5 to 8 The method executed by the AMF or the method executed by the first access network device in the illustrated embodiment, or the method that causes the computer to execute... Figure 7 The method executed by the second access network device in the illustrated embodiment.

[0353] This application also provides a computer-readable storage medium storing a computer program (also referred to as code or instructions). When the computer program is executed, it causes the computer to perform... Figure 5 or Figure 8 The method executed by the AMF or the method executed by the first access network device in the illustrated embodiment, or the method that causes the computer to execute... Figure 7 The method executed by the second access network device in the illustrated embodiment.

[0354] The terms “unit”, “module”, etc., used in this specification may be used to refer to computer-related entities, hardware, firmware, combinations of hardware and software, software, or software in execution.

[0355] Those skilled in the art will recognize that the various illustrative logical blocks and steps 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 implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application. In the several embodiments provided in this application, it should be understood that the disclosed apparatus, devices, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for example, the division of units is merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the shown or discussed mutual couplings or direct couplings or communication connections may be through some interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0356] The unit described as a separate component may or may not be physically separate. The component shown as a unit may or may not be a physical unit; that is, it may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0357] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0358] In the above embodiments, the functions of each functional unit can be implemented entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. This computer program product includes one or more computer instructions (programs). When the computer program instructions (programs) are loaded and executed on a computer, all or part of the flow or function described in the embodiments of this application is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., digital video discs (DVDs)), or semiconductor media (e.g., solid-state disks (SSDs)).

[0359] If this function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0360] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method, characterized in that, include: It is determined that the load of the first mobile relay exceeds a first preset threshold; It is determined that the load of the second mobile relay is lower than the second preset threshold, and it is determined that the movement trajectory of the second mobile relay in the first time period is the same as the movement trajectory of the first mobile relay in the first time period. Send the information of the second mobile relay to the first access network device. The information of the second mobile relay is used to connect the terminal device to the second mobile relay. The first mobile relay and the second mobile relay are in a mobile state, and the first mobile relay is used to provide relay services between the terminal device and the first access network device. The method further includes: The first time duration is sent to the first access network device. After the first time duration expires, the first mobile relay can provide relay services between the terminal device and the first access network device. The first duration is less than or equal to the duration of the first time period.

2. The method as described in claim 1, characterized in that, Before sending the information of the second mobile relay to the first access network device, the method further includes: The system receives the identifier of the first mobile relay and a registration request message from the terminal device from the first access network device. The identifier of the first mobile relay is used to indicate that the registration request message is forwarded to the first access network device through the first mobile relay.

3. The method as described in claim 1 or 2, wherein the second mobile relay is used to provide relay services between the terminal device and the second access network device, wherein the first access network device and the second access network device are the same access network device, or the first access network device and the second access network device are different access network devices.

4. The method as described in claim 3, characterized in that, The information of the second mobile relay includes the identifier of the second mobile relay, which corresponds to the frequency point of the second mobile relay.

5. The method as described in claim 3, characterized in that, The information of the second mobile relay includes the frequency point of the second mobile relay.

6. The method as described in claim 4, characterized in that, The first access network device and the second access network device are different access network devices; as well as Before sending the information of the second mobile relay to the first access network device, the method further includes: Send the identifier of the second mobile relay to the second access network device; Receive the frequency point of the second mobile relay from the second access network device.

7. The method according to any one of claims 1-2 and 4-6, characterized in that, The method further includes: Obtain the load of the first mobile relay and the load of the second mobile relay.

8. The method according to any one of claims 1-2 and 4-6, characterized in that, The method further includes: Obtain the movement trajectory of the first mobile relay and the movement trajectory of the second mobile relay.

9. A communication method, characterized in that, include: It is determined that the load of the first mobile relay exceeds a first preset threshold; It is determined that the load of the second mobile relay is lower than the second preset threshold, and it is determined that the movement trajectory of the second mobile relay in the first time period is the same as the movement trajectory of the first mobile relay in the first time period. Determine that the terminal device requests access from the first mobile trunk at the first moment of the first time period; The frequency point of the second mobile relay is sent to the terminal device, and the frequency point of the second mobile relay is used by the terminal device to access the second mobile relay; Also includes: Receive the first duration; After the first duration expires, the first mobile relay is controlled to provide relay services between the terminal device and the first access network device; the first duration is less than or equal to the duration of the first time period.

10. The method as described in claim 9, characterized in that, The method further includes: Obtain the load of the first mobile relay and the load of the second mobile relay.

11. The method as described in claim 9 or 10, characterized in that, The method further includes: Obtain the movement trajectory of the first mobile relay and the movement trajectory of the second mobile relay.

12. A communication device, characterized in that, include: The processing unit is used to determine that the load of the first mobile relay exceeds a first preset threshold; The load of the second mobile relay is determined to be lower than a second preset threshold, and is used to determine that the movement trajectory of the second mobile relay in the first time period is the same as the movement trajectory of the first mobile relay in the first time period. The transceiver unit is used to send information about the second mobile relay to the first access network device. The information about the second mobile relay is used to connect the terminal device to the second mobile relay. The first mobile relay and the second mobile relay are in a mobile state, and the first mobile relay is used to provide relay services between the terminal device and the first access network device. The transceiver unit is also configured to send a first duration to the first access network device. After the first duration expires, the first mobile relay can provide relay services between the terminal device and the first access network device. The first duration is less than or equal to the duration of the first time period.

13. The apparatus as claimed in claim 12, characterized in that, The transceiver unit is further configured to receive from the first access network device the identifier of the first mobile relay and a registration request message from the terminal device, wherein the identifier of the first mobile relay is used to indicate that the registration request message is forwarded to the first access network device through the first mobile relay.

14. The apparatus as claimed in claim 12 or 13, characterized in that, The second mobile relay is used to provide relay services between a terminal device and a second access network device, wherein the first access network device and the second access network device are the same access network device, or the first access network device and the second access network device are different access network devices.

15. The apparatus as claimed in claim 14, characterized in that, The information of the second mobile relay includes the identifier of the second mobile relay, which corresponds to the frequency point of the second mobile relay.

16. The apparatus as claimed in claim 14, characterized in that, The information of the second mobile relay includes the frequency point of the second mobile relay.

17. The apparatus as claimed in claim 16, characterized in that, The first access network device and the second access network device are different access network devices. The transceiver unit is also used to send the identifier of the second mobile relay to the second access network device; and to receive the frequency point of the second mobile relay from the second access network device.

18. The apparatus as described in any one of claims 12-13 and 15-17, characterized in that, The processing unit is also used to acquire the load of the first mobile relay and the load of the second mobile relay.

19. The apparatus as described in any one of claims 12-13 and 15-17, characterized in that, The processing unit is also used to acquire the movement trajectory of the first mobile relay and the movement trajectory of the second mobile relay.

20. A communication device, characterized in that, include: The processing unit is used to determine that the load of the first mobile relay exceeds a first preset threshold; The system determines that the load of the second mobile relay is lower than a second preset threshold, and is used to determine that the movement trajectory of the second mobile relay in the first time period is the same as that of the first mobile relay in the first time period; it is also used to determine that the terminal device requests access from the first mobile relay at the first moment of the first time period. A transceiver unit is used to send the frequency point of the second mobile relay to the terminal device, wherein the frequency point of the second mobile relay is used by the terminal device to access the second mobile relay; The transceiver unit is also configured to receive a first duration; after the first duration expires, control the first mobile relay to provide relay services between the terminal device and the first access network device; The first duration is less than or equal to the duration of the first time period.

21. The apparatus as claimed in claim 20, characterized in that, The processing unit is also used to acquire the load of the first mobile relay and the load of the second mobile relay.

22. The apparatus as claimed in claim 20 or 21, characterized in that, The processing unit is also used to acquire the movement trajectory of the first mobile relay and the movement trajectory of the second mobile relay.

23. A communication device, characterized in that, Includes a processor, the processor being used to call program code to implement the method as described in any one of claims 1 to 11.

24. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it causes the computer to perform the method as described in any one of claims 1 to 11.

25. A computer program product, characterized in that, Includes a computer program that, when run, causes a computer to perform the method as described in any one of claims 1 to 11.

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