Communication method, communication apparatus, and communication system

Abstract

The present application provides a communication method, a communication apparatus, and a communication system. The method comprises: receiving first tracking area identity information from a terminal device, wherein the first tracking area identity information is tracking area identity information supported by a second access network device accessed by the terminal device or tracking area identity information corresponding to first position information of the terminal device; on the basis of the first tracking area identity information, determining second tracking area identity information supported by a first access network device, wherein the terminal device and the first access network device form a vehicle-mounted relay (VMR) device. The solution allows for accurate determination of the tracking area identification information supported by the first access network device (i.e., the VMR access network device), so that the first access network device can better provide services to surrounding terminal devices, thereby improving the communication quality.

Description

Communication method, communication device and communication system

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of the People's Republic of China on October 27, 2023, with application number 202311425033.6 and invention name "A communication method, communication device and communication system", the entire contents of which are incorporated by reference into this application. Technical Field

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

[0004] Currently, vehicle mounted relay (VMR) devices are proposed based on vehicle-mounted scenarios. VMR devices are usually deployed on moving vehicles and consist of access network devices and terminal devices. The terminal devices can be called VMR terminal devices, and the access network devices can be called VMR access network devices.

[0005] Because vehicles move, VMR access network equipment and VMR terminal devices also have mobility. VMR terminal devices have the functions of ordinary terminal devices and can access the core network via new radio (NR). While the N2 backhaul link between fixed ground access network equipment and the core network can typically be implemented using optical fiber, the N2 backhaul link between mobile VMR access network equipment and the core network can be carried over the protocol data unit (PDU) session between the VMR terminal device and the core network to achieve wireless backhaul. This allows the VMR access network equipment to provide wireless access to other terminal devices near the vehicle.

[0006] The VMR access network device needs to broadcast the tracking area identification information supported by the VMR access network device so that the surrounding terminal devices can determine whether they can access the VMR access network device.

[0007] However, how to accurately determine the tracking area identification information supported by the VMR access network device remains to be solved.

[0008] Summary of the Invention

[0009] The embodiments of the present application provide a communication method, a communication device, and a communication system for accurately determining tracking area identification information supported by a VMR access network device.

[0010] In a first aspect, an embodiment of the present application provides a communication method, which can be performed by a first access network device or a module (such as a chip) in the first access network device. The method includes: receiving first tracking area identification information from a terminal device, where the first tracking area identification information is tracking area identification information supported by a second access network device accessed by the terminal device, or tracking area identification information corresponding to the first location information of the terminal device; determining second tracking area identification information supported by the first access network device based on the first tracking area identification information; wherein the terminal device and the first access network device constitute an on-board relay device.

[0011] The above solution realizes accurate determination of the tracking area identification information supported by the first access network device (ie, the VMR access network device), so that the first access network device can better provide services to the surrounding terminal devices, which helps to improve the communication quality.

[0012] In a possible implementation method, before receiving the first tracking area identification information from the terminal device, it also includes: sending a request message to the terminal device, where the request message is used to trigger the terminal device to obtain the first tracking area identification information.

[0013] The above solution can enable the terminal device to quickly obtain the tracking area identification information by triggering the terminal device through a request message when the first access network device needs to obtain the tracking area identification information.

[0014] In one possible implementation method, the request message includes indication information, and the indication information is used to indicate at least one of the following: the type of the terminal device, the type of the terminal device indicates that the terminal device is a vehicle-mounted relay terminal device jointly installed with the first access network device; the capability of the terminal device, the capability of the terminal device is to use a PDU session to establish a wireless backhaul link; a request for tracking area identification information that can be used for the first access network device; and a request for tracking area identification information associated with the first access network device.

[0015] In the above solution, the mobility management network element is triggered to quickly obtain the tracking area identification information through the indication information.

[0016] In a possible implementation method, after determining the second tracking area identification information supported by the first access network device based on the first tracking area identification information, it also includes: receiving third tracking area identification information from the terminal device, the third tracking area identification information is the tracking area identification information supported by the third access network device to which the terminal device accesses, or is the tracking area identification information corresponding to the second location information of the terminal device.

[0017] The above solution can update the tracking area identification information for the first access network device, so that the first access network device can broadcast the updated tracking area identification information to provide better services for surrounding terminal devices.

[0018] In a possible implementation method, the method further includes: determining fourth tracking area identification information supported by the first access network device based on the third tracking area identification information.

[0019] In a possible implementation method, determining the fourth tracking area identification information supported by the first access network device based on the third tracking area identification information includes: when the third tracking area identification information is different from the first tracking area identification information, determining the fourth tracking area identification information supported by the first access network device based on the third tracking area identification information.

[0020] In the above scheme, when the third tracking area identification information is different from the first tracking area identification information, the fourth tracking area identification information supported by the first access network device is determined based on the third tracking area identification information. That is, if the third tracking area identification information is the same as the first tracking area identification information, there is no need to re-determine the tracking area identification information, thereby reducing unnecessary computing overhead.

[0021] In a second aspect, an embodiment of the present application provides a communication method, which can be executed by a terminal device or a module (such as a chip) in the terminal device. The method includes: obtaining first tracking area identification information, where the first tracking area identification information is tracking area identification information supported by a second access network device accessed by the terminal device, or tracking area identification information corresponding to the first location information of the terminal device; sending the first tracking area identification information to the first access network device, where the first tracking area identification information is used to determine second tracking area identification information supported by the first access network device; wherein the terminal device and the first access network device constitute an on-board relay device.

[0022] The above solution realizes accurate determination of the tracking area identification information supported by the first access network device (ie, the VMR access network device), so that the first access network device can better provide services to the surrounding terminal devices, which helps to improve the communication quality.

[0023] In one possible implementation method, obtaining the first tracking area identification information includes: sending a NAS request message to a first mobility management network element, where the first mobility management network element is the mobility management network element where the terminal device is registered; and receiving a NAS response message from the first mobility management network element, where the NAS response message includes the first tracking area identification information.

[0024] The above solution carries the first tracking area identification information in the NAS response message, without adding additional signaling to carry the first tracking area identification information, which can reduce signaling overhead.

[0025] In one possible implementation method, the NAS request message also includes indication information, and the indication information is used to indicate at least one of the following: the type of the terminal device, the type of the terminal device indicates that the terminal device is a vehicle-mounted relay terminal device jointly installed with the first access network device; the capability of the terminal device, the capability of the terminal device is to use a PDU session to establish a wireless backhaul link; a request for tracking area identification information that can be used for the first access network device; and a request for tracking area identification information associated with the first access network device.

[0026] The above solution can quickly determine the tracking area identification information for the first access network device by triggering the determination of the tracking area identification information for the first access network device through the indication information.

[0027] In a possible implementation method, the method also includes: receiving a configuration update message from the first mobility management network element, the configuration update message including third tracking area identification information, the third tracking area identification information being the tracking area identification information supported by the third access network device to which the terminal device accesses, or being the tracking area identification information corresponding to the second location information of the terminal device; sending the third tracking area identification information to the first access network device, the third tracking area identification information being used to determine the fourth tracking area identification information supported by the first access network device.

[0028] The above solution can update the tracking area identification information for the first access network device, so that the first access network device can broadcast the updated tracking area identification information to provide better services for surrounding terminal devices.

[0029] In a possible implementation method, before obtaining the first tracking area identification information, it also includes: receiving a request message from the first access network device, the request message includes indication information, and the indication information is used to indicate at least one of the following: the type of the terminal device, the type of the terminal device indicates that the terminal device is a vehicle-mounted relay terminal device jointly set up with the first access network device; the capability of the terminal device, the capability of the terminal device is to have the ability to use PDU sessions to establish a wireless backhaul link; requesting tracking area identification information that can be used for the first access network device; requesting tracking area identification information associated with the first access network device; obtaining the first tracking area identification information includes: sending the request message to a second mobility management network element, the second mobility management network element is the mobility management network element accessed by the first access network device through the wireless backhaul link; receiving a response message from the second mobility management network element, the response message includes the first tracking area identification information.

[0030] In one possible implementation method, sending the request message to the second mobility management network element includes: sending uplink data to the user plane network element, the uplink data includes the request message and the address of the second mobility management network element, and the request message is forwarded by the user plane network element to the second mobility management network element; receiving a response message from the second mobility management network element includes: receiving first downlink data from the user plane network element, the first downlink data includes the response message, and the response message in the first downlink data comes from the second mobility management network element.

[0031] In a possible implementation method, the method also includes: receiving second downlink data from the user plane network element, the first downlink data includes a configuration update message, the configuration update message includes third tracking area identification information, the third tracking area identification information is the tracking area identification information supported by the third access network device accessed by the terminal device, or is the tracking area identification information corresponding to the second location information of the terminal device; sending the configuration update message to the first access network device, the third tracking area identification information in the configuration update message is used to determine the fourth tracking area identification information supported by the first access network device.

[0032] The above solution can update the tracking area identification information for the first access network device, so that the first access network device can broadcast the updated tracking area identification information to provide better services for surrounding terminal devices.

[0033] In a third aspect, an embodiment of the present application provides a communication method, which can be executed by a second mobility management network element or a module (such as a chip) in the second mobility management network element. The method includes: receiving a request message from a first access network device, the request message including indication information, the indication information being used to indicate at least one of the following: a type of terminal device, the type of terminal device indicating that the terminal device is an on-vehicle relay terminal device jointly provided with the first access network device; a capability of the terminal device, the capability of the terminal device being the ability to establish a wireless backhaul link using a PDU session; requesting tracking area identification information that can be used for the first access network device; requesting tracking area identification information associated with the first access network device; obtaining first tracking area identification information based on the indication information, the first tracking area identification information being tracking area identification information supported by a second access network device accessed by the terminal device, or tracking area identification information corresponding to first location information of the terminal device; and sending a response message to the first access network device, the response message including the first tracking area identification information, the first tracking area identification information being used to determine second tracking area identification information supported by the first access network device; wherein the terminal device and the first access network device constitute an on-vehicle relay device, and the second mobility management network element is a mobility management network element accessed by the first access network device via a wireless backhaul link.

[0034] The above solution realizes accurate determination of the tracking area identification information supported by the first access network device (ie, the VMR access network device), so that the first access network device can better provide services to the surrounding terminal devices, which helps to improve the communication quality.

[0035] In one possible implementation method, receiving a request message from a first access network device includes: receiving the request message from the first access network device through a user plane network element; sending a response message to the first access network device includes: sending the response message to the first access network device through the user plane network element.

[0036] In one possible implementation method, obtaining the first tracking area identification information includes: sending a subscription request message to a first mobility management network element, where the subscription request message is used to subscribe to the tracking area identification information supported by the second access network device accessed by the terminal device, and the first mobility management network element is the mobility management network element registered by the terminal device; and receiving the first tracking area identification information from the first mobility management network element.

[0037] In a possible implementation method, the method also includes: receiving a subscription notification message from the first mobility management network element, the subscription notification message including third tracking area identification information, the third tracking area identification information being the tracking area identification information supported by the third access network device accessed by the terminal device; and sending a configuration update message to the first access network device, the configuration update message including the third tracking area identification information, the third tracking area identification information being used to determine the fourth tracking area identification information supported by the first access network device.

[0038] In the above solution, the second mobility management network element can obtain the latest tracking area identification information in a timely manner through subscription, which helps to quickly determine the tracking area identification information that can be used for the first access network device.

[0039] In one possible implementation method, obtaining the first tracking area identification information includes: sending a subscription request message to a first mobility management network element, where the subscription request message is used to subscribe to the location information of the terminal device, and the first mobility management network element is the mobility management network element where the terminal device is registered; receiving the first location information of the terminal device from the mobility management network element; and obtaining the first tracking area identification information corresponding to the first location information.

[0040] In a possible implementation method, obtaining the first tracking area identification information corresponding to the first location information includes: sending the first location information to a network open network element; and receiving the first tracking area identification information from the network open network element.

[0041] In a possible implementation method, the method also includes: receiving a subscription notification message from the first mobility management network element, the subscription notification message including the second location information of the terminal device; obtaining third tracking area identification information corresponding to the second location information, the third tracking area identification information being the tracking area identification information corresponding to the second location information; sending a configuration update message to the first access network device, the configuration update message including the third tracking area identification information, and the third tracking area identification information being used to determine the fourth tracking area identification information supported by the first access network device.

[0042] In the above solution, the second mobility management network element can obtain the latest tracking area identification information in a timely manner through subscription, which helps to quickly determine the tracking area identification information that can be used for the first access network device.

[0043] In a fourth aspect, embodiments of the present application provide a communication method, which can be performed by a second mobility management network element or a module (e.g., a chip) in the second mobility management network element. The method includes: sending first location information of a terminal device to an open network element; receiving first tracking area identification information corresponding to the first location information from the open network element; and sending the first tracking area identification information to the terminal device.

[0044] In a fifth aspect, an embodiment of the present application provides a communication method, which can be performed by an on-board relay device or a module (such as a chip) in the on-board relay device. The method includes: obtaining first tracking area identification information, where the first tracking area identification information is tracking area identification information supported by a second access network device accessed by the on-board relay device, or tracking area identification information corresponding to the first location information of the on-board relay device; and determining second tracking area identification information supported by the on-board relay device based on the first tracking area identification information.

[0045] The above solution can accurately determine the tracking area identification information supported by the vehicle-mounted relay device, so that the vehicle-mounted relay device can better provide services to surrounding terminal devices, which helps to improve communication quality.

[0046] In one possible implementation method, obtaining the first tracking area identification information includes: sending a NAS request message to a first mobility management network element, where the first mobility management network element is the mobility management network element where the vehicle-mounted relay device is registered; and receiving a NAS response message from the first mobility management network element, where the NAS response message includes the first tracking area identification information.

[0047] The above solution carries the first tracking area identification information in the NAS response message, without adding additional signaling to carry the first tracking area identification information, which can reduce signaling overhead.

[0048] In one possible implementation method, the NAS request message also includes indication information, and the indication information is used to indicate at least one of the following: the type of the vehicle-mounted relay device, the type of the vehicle-mounted relay device indicates a vehicle-mounted relay terminal device that is equipped with a vehicle-mounted terminal device and a vehicle-mounted access network device; the capability of the vehicle-mounted relay device, the capability of the vehicle-mounted relay device is to be able to establish a wireless backhaul link using a PDU session; a request for tracking area identification information that can be used for the vehicle-mounted relay device; and a request for tracking area identification information associated with the vehicle-mounted relay device.

[0049] The above solution can quickly determine the tracking area identification information for the first access network device by triggering the determination of the tracking area identification information for the first access network device through the indication information.

[0050] In a possible implementation method, the method also includes: receiving a configuration update message from the first mobility management network element, the configuration update message including third tracking area identification information, the third tracking area identification information being the tracking area identification information supported by the third access network device to which the vehicle-mounted relay device accesses, or being the tracking area identification information corresponding to the second location information of the vehicle-mounted relay device.

[0051] The above solution can update the tracking area identification information for the first access network device, so that the first access network device can broadcast the updated tracking area identification information to provide better services for surrounding terminal devices.

[0052] In one possible implementation method, obtaining the first tracking area identification information includes: sending a request message to a second mobility management network element, the request message including indication information, the indication information being used to indicate at least one of the following: the type of the vehicle-mounted relay device, the type of the vehicle-mounted relay device indicating a vehicle-mounted relay terminal device that is equipped with a vehicle-mounted terminal device and a vehicle-mounted access network device; the capability of the vehicle-mounted relay device, the capability of the vehicle-mounted relay device being the ability to establish a wireless backhaul link using a PDU session; requesting tracking area identification information that can be used for the vehicle-mounted relay device; requesting tracking area identification information associated with the vehicle-mounted relay device, the second mobility management network element being the mobility management network element accessed by the vehicle-mounted relay device through the wireless backhaul link; receiving a response message from the second mobility management network element, the response message including the first tracking area identification information.

[0053] The above solution can quickly determine the tracking area identification information for the first access network device by triggering the determination of the tracking area identification information for the first access network device through the indication information.

[0054] In one possible implementation method, sending the request message to the second mobility management network element includes: sending uplink data to the user plane network element, the uplink data includes the request message and the address of the second mobility management network element, and the request message is forwarded by the user plane network element to the second mobility management network element; receiving a response message from the second mobility management network element includes: receiving first downlink data from the user plane network element, the first downlink data includes the response message, and the response message in the first downlink data comes from the second mobility management network element.

[0055] In a possible implementation method, the method also includes: receiving second downlink data from the user plane network element, the first downlink data includes a configuration update message, the configuration update message includes third tracking area identification information, the third tracking area identification information is the tracking area identification information supported by the third access network device to which the vehicle-mounted relay device accesses, or is the tracking area identification information corresponding to the second location information of the vehicle-mounted relay device.

[0056] The above solution can update the tracking area identification information for the first access network device, so that the first access network device can broadcast the updated tracking area identification information to provide better services for surrounding terminal devices.

[0057] In a possible implementation method, the method further includes: determining fourth tracking area identification information supported by the vehicle-mounted relay device based on the third tracking area identification information.

[0058] In a possible implementation method, determining the fourth tracking area identification information supported by the vehicle-mounted relay device based on the third tracking area identification information includes: when the third tracking area identification information is different from the first tracking area identification information, determining the fourth tracking area identification information supported by the vehicle-mounted relay device based on the third tracking area identification information.

[0059] In the above scheme, when the third tracking area identification information is different from the first tracking area identification information, the fourth tracking area identification information supported by the first access network device is determined based on the third tracking area identification information. That is, if the third tracking area identification information is the same as the first tracking area identification information, there is no need to re-determine the tracking area identification information, thereby reducing unnecessary computing overhead.

[0060] In a sixth aspect, an embodiment of the present application provides a communication device, which may be a first access network device or a module (such as a chip) in the first access network device. The device has the function of implementing any implementation method of the first aspect described above. The function may be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

[0061] In a seventh aspect, an embodiment of the present application provides a communication device, which may be a terminal device or a module (such as a chip) in the terminal device. The device has the function of implementing any implementation method of the second aspect described above. The function may be implemented by hardware or by hardware executing corresponding software implementations. The hardware or software includes one or more modules corresponding to the above functions.

[0062] In an eighth aspect, an embodiment of the present application provides a communication device, which may be a second mobility management network element, or a module (such as a chip) in the second mobility management network element. The device has the function of implementing any implementation method of the third or fourth aspects described above. The function may be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

[0063] In a ninth aspect, an embodiment of the present application provides a communication device, which may be an on-board relay device or a module (such as a chip) in the on-board relay device. The device has the function of implementing any implementation method of the fourth aspect above. The function can be implemented by hardware or by executing corresponding software implementation by hardware. The hardware or software includes one or more modules corresponding to the above functions.

[0064] In a tenth aspect, an embodiment of the present application provides a communication device, comprising a unit or means for executing each step of any implementation method in the above-mentioned first to fifth aspects.

[0065] In an eleventh aspect, an embodiment of the present application provides a communication device, comprising a processor and an interface circuit, wherein the processor is configured to communicate with other devices via the interface circuit and execute any of the implementation methods described in the first to fifth aspects. The processor comprises one or more.

[0066] Optionally, the communication device may further include a memory for storing computer instructions, the memory being coupled to a processor, and the processor executing the computer instructions stored in the memory so that the device executes any implementation method in the first to fifth aspects above.

[0067] In the twelfth aspect, an embodiment of the present application further provides a computer program product, which includes a computer program or instructions. When the computer program or instructions are run by a communication device, any implementation method in the above-mentioned first to fifth aspects is executed.

[0068] In the thirteenth aspect, an embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores instructions, which, when run on a communication device, enables any implementation method in the above-mentioned first to fifth aspects to be executed.

[0069] In the fourteenth aspect, an embodiment of the present application also provides a chip system, including: a processor, used to execute any implementation method in the above-mentioned first to fifth aspects.

[0070] In the fifteenth aspect, an embodiment of the present application also provides a communication system, including a first access network device for executing any implementation method of the first aspect, and a terminal device for executing any implementation method of the above-mentioned second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1(a) is a schematic diagram of the 5G network architecture based on service-oriented architecture;

[0072] Figure 1(b) is a schematic diagram of the 5G network architecture based on point-to-point interfaces;

[0073] Figure 2 is a schematic diagram of TA;

[0074] FIG3 is a schematic diagram of the basic architecture of a VMR;

[0075] Figure 4 is a schematic diagram of forwarding N2 messages between the VMR-gNB and the AMF through a PDU session;

[0076] FIG5( a ) is a flow chart of a communication method provided in an embodiment of the present application;

[0077] FIG5( b ) is a flow chart of a communication method provided in an embodiment of the present application;

[0078] FIG6 is a flow chart of a communication method provided in an embodiment of the present application;

[0079] FIG7 is a flow chart of a communication method provided in an embodiment of the present application;

[0080] FIG8 is a flow chart of a communication method provided in an embodiment of the present application;

[0081] FIG9 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0082] FIG10 is a schematic diagram of the structure of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0083] To meet the challenges of wireless broadband technology and maintain the leading edge of the Third Generation Partnership Project (3GPP) network, the 3GPP standards group has developed the Next Generation System (NGS) architecture, known as the 5G network architecture. This architecture not only supports access to the 5G core network (CN) using 3GPP-defined radio access technologies (such as Long Term Evolution (LTE) and 5G Radio Access Network (RAN)), but also supports access to the 5G core network using non-3GPP access technologies via the non-3GPP interworking function (N3IWF) or the next generation packet data gateway (ngPDG).

[0084] Figure 1(a) shows a schematic diagram of a 5G network architecture based on a service-oriented architecture. The 5G network architecture shown in Figure 1(a) may include access network equipment and core network equipment. Terminal devices access the data network (DN) through the access network equipment and core network equipment. Among them, the core network equipment includes but is not limited to some or all of the following network elements: authentication server function (AUSF) network element (not shown in the figure), unified data management (UDM) network element, unified data repository (UDR) network element, network storage function (NRF) network element (not shown in the figure), network exposure function (NEF) network element (not shown in the figure), application function (AF) network element, policy control function (PCF) network element, access and mobility management function (AMF) network element, session management function (SMF) network element, user plane function (UPF) network element, binding support function (BSF) network element (not shown in the figure).

[0085] Terminal devices can be user equipment (UE), mobile stations, mobile terminal devices, etc. Terminal devices can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wearables, smart transportation, smart cities, etc. Terminal devices can be mobile phones, tablets, computers with wireless transceiver functions, wearable devices, vehicles, urban air vehicles (such as drones and helicopters), ships, robots, robotic arms, smart home devices, etc.

[0086] Access network equipment can be a radio access network (RAN) device or a wireline access network (FAN) device. Among them, radio access network equipment includes 3GPP access network equipment, untrusted non-3GPP access network equipment and trusted non-3GPP access network equipment. 3GPP access network equipment includes but is not limited to: evolved NodeB (eNodeB) in LTE, next generation NodeB (gNB) in 5G mobile communication system, base station in future mobile communication system or module or unit that completes part of the functions of base station, such as centralized unit (CU), distributed unit (DU), etc. Untrusted non-3GPP access network equipment includes but is not limited to: untrusted non-3GPP access gateway or N3IWF device, untrusted wireless local area network (WLAN) access point (AP), switch, router. Trusted non-3GPP access network equipment includes but is not limited to: trusted non-3GPP access gateway, trusted WLAN AP, switch, router. Wired access network equipment includes but is not limited to: wireline access gateway, fixed telephone network equipment, switches, and routers.

[0087] Access network equipment and terminal devices can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; on water; or in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of access network equipment and terminal devices.

[0088] The AMF network element is responsible for UE mobility management, including mobile state management, allocating temporary identities to UEs, and authenticating and authorizing UEs.

[0089] The SMF network element is responsible for the selection and reselection of UPF network elements, IP address allocation, bearer establishment, modification and release, and quality of service (QoS) control.

[0090] The UPF network element supports all or part of the following functions: interconnecting protocol data unit (PDU) sessions with the data network; packet routing and forwarding (for example, supporting uplink classification (Uplink classifier) ​​of traffic before forwarding to the data network); and data packet inspection.

[0091] The UDM network element is responsible for managing contract data and notifying the corresponding network element when the contract data is modified.

[0092] The UDR network element stores and retrieves contract data, policy data, and public architecture data; it provides access to relevant data for UDM, PCF, and NEF network elements. The UDR network element must implement different data access authentication mechanisms for different types of data, such as contract data and policy data, to ensure data access security. The UDR network element must be able to return a failure response with an appropriate cause value for illegal service-based operations or data access requests.

[0093] NEF network element is used to support the opening of capabilities and events.

[0094] The AF network element communicates application-side requirements to the network, such as QoS requirements or user status event subscriptions. The AF can be a third-party functional entity or an application service deployed by a carrier, such as the IP Multimedia Subsystem (IMS) voice call service. AF network elements include those within the core network (i.e., the carrier's AF network element) and third-party AF network elements (such as an enterprise's application server).

[0095] The PCF network element includes policy control functions such as billing for sessions and service flow levels, QoS bandwidth guarantee and mobility management, and terminal device policy decision-making. PCF network elements include access and mobility management policy control function (AM PCF) network element and session management policy control function (SM PCF) network element. Among them, the AM PCF network element is used to formulate AM policies for terminal devices. The AM PCF network element can also be called a policy control network element that provides services for terminal devices (PCF for a UE). The SM PCF network element is used to formulate session management policies (SM policies) for sessions. The SM PCF network element can also be called a policy control network element that provides services for sessions (PCF for a PDU session).

[0096] NRF network elements can be used to provide network element discovery capabilities, providing network element information corresponding to the network element type based on requests from other network elements. NRF also provides network element management services such as network element registration, update, and deregistration, as well as network element status subscription and push.

[0097] The BSF network element can provide BSF service registration / deregistration / update, NRF connection detection, session binding information creation, UE information acquisition, and session binding information query for duplicate IP addresses.

[0098] The AUSF network element is responsible for authenticating the UE to determine whether the UE is allowed to access the network.

[0099] A DN is a network located outside of a carrier network. A carrier network can connect to multiple DNs, and a variety of services can be deployed on the DN, providing data and / or voice services to terminal devices. For example, a DN is the private network of a smart factory. Sensors installed in the workshop can be terminal devices. The DN houses a sensor control server, which provides services to the sensors. Sensors can communicate with the control server, receive instructions from the control server, and transmit collected sensor data to the control server based on the instructions. Another example is a DN that is a company's internal office network. An employee's mobile phone or computer can be a terminal device, allowing them to access information and data resources on the company's internal office network.

[0100] In Figure 1(a), Npcf, Nufr, Nudm, Naf, Namf, and Nsmf are the service-oriented interfaces provided by the PCF, UDR, UDM, AF, AMF, and SMF, respectively, for invoking corresponding service-oriented operations. N1, N2, N3, N4, and N6 are interface serial numbers, and their meanings are as follows:

[0101] 1) N1: The interface between AMF and terminal devices, which can be used to deliver non-access stratum (NAS) signaling (such as QoS rules from AMF) to terminal devices.

[0102] 2) N2: The interface between AMF and access network equipment, which can be used to transmit radio bearer control information from the core network side to the access network equipment.

[0103] 3) N3: The interface between the access network equipment and UPF, mainly used to transmit uplink and downlink user plane data between the access network equipment and UPF.

[0104] 4) N4: The interface between SMF and UPF can be used to transmit information between the control plane and the user plane, including controlling the issuance of forwarding rules, QoS rules, traffic statistics rules, etc. for the user plane and reporting information on the user plane.

[0105] 5) N6: Interface between UPF and DN, used to transmit uplink and downlink user data flows between UPF and DN.

[0106] Figure 1(b) is a schematic diagram of a 5G network architecture based on point-to-point interfaces. The functions of the network elements in Figure 1(a) can be referred to for the functions of the corresponding network elements, and will not be repeated here. The main difference between Figure 1(b) and Figure 1(a) is that the interfaces between the control plane network elements in Figure 1(a) are service-oriented interfaces, while the interfaces between the control plane network elements in Figure 1(b) are point-to-point interfaces.

[0107] In the architecture shown in Figure 1(b), the interface names and functions between the various network elements are as follows:

[0108] 1) For the meanings of the N1, N2, N3, N4 and N6 interfaces, please refer to the above description.

[0109] 2) N5: The interface between the AF network element and the PCF network element, which can be used to issue application service requests and report network events.

[0110] 3) N7: The interface between PCF network element and SMF network element, which can be used to issue PDU session granularity and service data flow granularity control strategy.

[0111] 4) N8: The interface between the AMF network element and the UDM network element, which can be used by the AMF network element to obtain access and mobility management related contract data and authentication data from the UDM network element, and the AMF network element to register terminal device mobility management related information with the UDM network element.

[0112] 5) N9: User plane interface between UPF network elements, used to transmit uplink and downlink user data flows between UPF network elements.

[0113] 6) N10: The interface between the SMF network element and the UDM network element, which can be used by the SMF network element to obtain session management related contract data from the UDM network element, and the SMF network element to register terminal device session related information with the UDM network element.

[0114] 7) N11: The interface between the SMF network element and the AMF network element, which can be used to transmit PDU session tunnel information between the access network device and the UPF, transmit control messages sent to the terminal device, transmit wireless resource control information sent to the access network device, etc.

[0115] 8) N15: The interface between the PCF network element and the AMF network element, which can be used to issue terminal device policies and access control related policies.

[0116] 9) N35: The interface between the UDM network element and the UDR network element, which can be used by the UDM network element to obtain user contract data information from the UDR network element.

[0117] 10) N36: Interface between PCF network element and UDR network element, which can be used by PCF network element to obtain policy-related contract data and application data-related information from UDR network element.

[0118] It is understood that the above-mentioned network element or function can be a network element in a hardware device, a software function running on dedicated hardware, or a virtualized function instantiated on a platform (e.g., a cloud platform). Optionally, the above-mentioned network element or function can be implemented by a single device, or by multiple devices, or can be a functional module within a single device, and this is not specifically limited in the embodiments of the present application.

[0119] The mobility management network element, user plane network element, and network open network element in this application can be the AMF network element, UPF network element, and NEF network element in the 5G system, respectively, or can be a network element with the functions of the above-mentioned AMF network element, UPF network element, and NEF network element in future communications such as 6G networks. This application is not limited to this. In the embodiments of this application, an example is described as the AMF network element, UPF network element, and NEF network element as the mobility management network element, user plane network element, and network open network element, respectively. In addition, the AMF network element, UPF network element, and NEF network element are referred to as AMF, UPF, and NEF, respectively.

[0120] For ease of explanation, the embodiments of the present application are described using a base station and a UE as specific examples of an access network device and a terminal device, respectively. Any base station and UE appearing in any subsequent location can be replaced by an access network device and a terminal device, respectively.

[0121] To facilitate understanding of the content of this application, the relevant background involved in the embodiments of this application is first introduced below.

[0122] Refer to Figure 2, which is a schematic diagram of a tracking area (TA). TA is a concept set by 3GPP for UE location management. One TA corresponds to a tracking area code (TAC). Each TA has a unique identifier, namely a tracking area identity (TAI), which consists of a TAC, a mobile country code (MCC) and a mobile network code (MNC). Multiple TAs can form a tracking area list (TAL). Depending on the coverage of the antenna, each base station can be divided into multiple sectors, and each sector can be divided into multiple cells. A cell can only belong to one TA, different cells in a base station can belong to different TAs, and the cells contained in a TA can belong to different base stations. In the example of Figure 2, each hexagon represents a TA, multiple TAs filled with dot patterns form a tracking area list, and multiple TAs filled with right-slash patterns form another tracking area list.

[0123] Currently, VMR devices are being proposed for in-vehicle scenarios. VMR devices are typically deployed on moving vehicles. A VMR device consists of a base station and a user equipment (UE). The UE can be referred to as a VMR-UE, and the base station can be referred to as a VMR-base station. Because vehicles move, the VMR-base station and VMR-UE also have mobility. The VMR-UE has the functions of a regular UE and can access the core network via NR. Typically, the N2 backhaul link between a fixed ground base station and the core network can be implemented using optical fiber. The N2 backhaul link between the mobile VMR-base station and the core network can be carried over the PDU session between the VMR-UE and the core network to achieve wireless backhaul. This allows the VMR-base station to provide wireless access to other UEs near the vehicle. The VMR device can also be referred to as a wireless access and backhaul (WAB) device. The UEs that make up the WAB can be referred to as WAB-UEs, and the base stations that make up the WAB can be referred to as WAB-base stations.

[0124] The following description takes the VMR-base station in the VMR device as an example, which is a VMR-gNB.

[0125] Figure 3 is a schematic diagram of the basic VMR architecture. A VMR-UE accesses the core network through a donor base station (e.g., donor-gNB) located outside the vehicle and establishes a PDU session between the VMR-UE and the UPF. N2 messaging between the VMR-gNB and the AMF is implemented through the PDU session between the VMR-UE and the UPF. For example, when the VMR-gNB needs to send an N2 message to the AMF, the VMR-gNB forwards the N2 message to the VMR-UE via the internal interface between the VMR-gNB and the VMR-UE. The VMR-UE uses the N2 message as the payload of the data packet and passes it to the corresponding UPF via the established PDU session. The UPF then forwards the data packet to the AMF, completing the forwarding of the N2 message. The donor base station is also called a macro base station.

[0126] Figure 4 is a schematic diagram of forwarding N2 messages between the VMR-gNB and the AMF through a PDU session. The method includes the following steps:

[0127] In step 401, the VMR-gNB sends an N2 request message to the VMR-UE. Accordingly, the VMR-UE receives the N2 request message.

[0128] The source IP address of the N2 request message is the IP address of the VMR-UE, and the destination address is the address of the AMF.

[0129] The N2 request message may be a next generation setup request (NG setup request) message. The NG setup request message carries the VMR-gNBID.

[0130] Step 402: The VMR-UE matches the correct PDU session for the N2 request message.

[0131] For example, the VMR-UE matches the correct PDU session according to the source IP address and / or destination address (ie, the address of the AMF) corresponding to the N2 request message.

[0132] Step 403: The VMR-UE sends uplink data to the UPF via the PDU session. Correspondingly, the UPF receives the uplink data.

[0133] The payload of the uplink data includes an N2 request message, the source IP address in the uplink data is the IP address of the VMR-UE, and the destination address in the uplink data is the address of the AMF. The AMF is the AMF accessed by the VMR-gNB through the wireless backhaul link.

[0134] In step 404, the UPF sends an N2 request message to the AMF based on the destination address in the uplink data. Accordingly, the AMF receives the N2 request message.

[0135] In step 405, the AMF sends an N2 response message to the UPF. Accordingly, the UPF receives the N2 response message.

[0136] For example, after processing the N2 request message from the VMR-gNB, the AMF constructs an N2 response message whose destination address is the IP address of the VMR-UE and whose source address is the address of the AMF. The AMF then sends the N2 response message to the UPF.

[0137] In step 406, the UPF sends downlink data to the VMR-UE via the PDU session, and the VMR-UE receives the downlink data accordingly.

[0138] The payload of the downlink data includes an N2 response message, the source IP address in the downlink data is the address of the AMF, and the destination address in the downlink data is the IP address of the VMR-UE.

[0139] In step 407, the VMR-UE sends an N2 response message to the VMR-gNB. Accordingly, the VMR-gNB receives the N2 response message.

[0140] The VMR-UE receives the downlink data packet, decapsulates it and obtains the N2 response message. If it finds that the N2 response message is not sent to itself, it forwards the N2 response message to the VMR-gNB.

[0141] At this point, the forwarding process of uplink and downlink N2 messages (i.e., N2 request message and N2 response message) is completed between the VMR-gNB and the AMF.

[0142] The following describes different scenarios in which the VMR-gNB may broadcast tracking area identity information (which may include at least one TAI and / or at least one TAC) during mobility:

[0143] Scenario 1: During the mobility of the VMR-gNB, the broadcast tracking area identification information remains unchanged.

[0144] That is, the TAI is bound to the donor-gNB or VMR-UE and does not change during mobility. That is, the tracking area identifier information broadcast by the VMR-gNB is inconsistent with the tracking area identifier information corresponding to the current geographic location of the VMR-gNB.

[0145] Scenario 2: During the movement of the VMR-gNB, the broadcast tracking area identification information may change.

[0146] For example, the tracking area identifier information broadcast by the VMR-gNB is consistent with the tracking area identifier information corresponding to the current geographic location of the VMR-gNB. For example, when the VMR-gNB moves from geographic location #1 to geographic location #2, the tracking area identifier information corresponding to geographic location #1 is different from the tracking area identifier information corresponding to geographic location #2. Therefore, the tracking area identifier information broadcast by the VMR-gNB must change.

[0147] The embodiment of the present application discusses the above-mentioned scenario 2, and specifically introduces how to configure the VMR-base station with appropriate tracking area identification information for broadcasting during the movement of the VMR device.

[0148] Figure 5(a) is a flow chart of a communication method provided in an embodiment of the present application. The method is performed by a first base station (or a module of the first base station) and a UE (or a module of the UE). Optionally, the method also includes other steps performed by a second base station (or a module of the second base station), a first AMF (or a module of the first AMF), and a second AMF (or a module of the second AMF). The first base station here refers to the VMR-base station in the VMR device (for example, the VMR-gNB in ​​Figure 3), and the UE here refers to the VMR-UE in the VMR device (for example, the VMR-UE in Figure 3), so the UE and the first base station form a vehicle-mounted relay device. The second base station here refers to the base station accessed by the VMR-UE (for example, the donor-gNB in ​​Figure 3). The first AMF here refers to the AMF registered by the VMR-UE (which can be called VMR-AMF), and the second AMF here refers to the AMF accessed by the first base station through the wireless backhaul link.

[0149] Alternatively, the first base station here refers to the WAB-base station in the WAB device, and the UE here refers to the WAB-UE in the WAB device, so the UE and the first base station constitute a WAB device. The second base station here refers to the base station accessed by the WAB-UE. The first AMF here refers to the AMF registered by the WAB-UE (which can be called WAB-AMF), and the second AMF here refers to the AMF accessed by the first base station through the wireless backhaul link.

[0150] Among them, the first base station and the second base station are different base stations, and the first AMF and the second AMF can be the same AMF or different AMFs.

[0151] In the following description, the method is described by taking the UE and the first base station forming a VMR device as an example, including the following steps:

[0152] In step 501a, the UE obtains first tracking area identification information, where the first tracking area identification information is tracking area identification information supported by a second base station accessed by the UE, or is tracking area identification information corresponding to the first location information of the UE.

[0153] The first tracking area identification information may include at least one TAI and / or at least one TAC.

[0154] The first location information of the UE is used to indicate the current location of the UE. For example, the first location information of the UE is the TAI, cell or other information where the UE is located.

[0155] Step 502a: The UE sends first tracking area identification information to the first base station. Correspondingly, the first base station receives the first tracking area identification information.

[0156] Step 503a: The first base station determines the second tracking area identification information supported by the first base station based on the first tracking area identification information.

[0157] The second tracking area identification information determined by the first base station may be the same as the first tracking area identification information, or the second tracking area identification information may be a part of the first tracking area identification information.

[0158] After the first base station determines the second tracking area identification information, it can broadcast the second tracking area identification information, so that the UE that receives the second tracking area identification information (the UE is a UE around the VMR device and not a VMR-UE) can determine whether it can access the first base station, so that the first base station can provide services for the UE around the vehicle.

[0159] The above solution can accurately determine the tracking area identification information supported by the vehicle-mounted relay base station, so that the vehicle-mounted relay base station can better provide services to surrounding UEs, which helps to improve communication quality.

[0160] The following introduces three different implementation methods for the UE to obtain the first tracking area identification information.

[0161] Implementation method 1: The first AMF determines the first tracking area identification information and sends the first tracking area identification information to the UE.

[0162] Based on the implementation method one, the first tracking area identification information determined by the first AMF is specifically the tracking area identification information supported by the second base station.

[0163] Based on the implementation method one, as an implementation method, before the above step 501a, the first base station sends a request message to the UE, and the request message is used to trigger the UE to obtain the first tracking area identification information. Then the above step 501a is specifically: the UE obtains the first tracking area identification information according to the request message.

[0164] Based on this implementation method 1, as an implementation method, step 501a above specifically comprises: the UE sends a NAS request message to the first AMF, and the UE receives a NAS response message from the first AMF, the NAS response message including the first tracking area identifier information determined by the first AMF. Optionally, the NAS request message includes indication information indicating at least one of the following: the UE type, where the UE type indicates that the UE is a VMR-UE co-located with a VMR-base station; the UE capability, where the UE capability is capable of establishing a wireless backhaul link using a PDU session; and the request for tracking area identifier information available for the first base station. This indication information triggers the first AMF to determine the first tracking area identifier information.

[0165] Exemplarily, the NAS request message may be a registration request message or a service request message, which is not limited in this application. The registration request message is used to request registration with the network, and the service request message is used to request establishment of a connection with the network. Accordingly, the NAS response message may be a registration accept message or a service response message.

[0166] Based on this implementation method 1, after step 503a above, if the vehicle moves, and the UE (referred to as the VMR-UE) and the first base station (i.e., the VMR-base station) on the vehicle also move, causing the UE to register with a new base station (e.g., a third base station), the first AMF obtains the third tracking area identification information, which is the tracking area identification information supported by the third base station accessed by the UE. The first AMF then sends a configuration update message to the UE, which includes the third tracking area identification information. The UE then sends the third tracking area identification information to the first base station. After receiving the third tracking area identification information, the first base station can determine the fourth tracking area identification information supported by the first base station based on the third tracking area identification information, or, if the first base station determines that the third tracking area identification information is different from the first tracking area identification information, determine the fourth tracking area identification information supported by the first base station based on the third tracking area identification information. The first base station can subsequently broadcast the fourth tracking area identification information. This implementation method will be further described in conjunction with Figure 6 below.

[0167] Implementation method 2: The second AMF determines the first tracking area identification information and sends the first tracking area identification information to the UE.

[0168] Based on the second implementation method, the first tracking area identification information determined by the second AMF is specifically the tracking area identification information supported by the second base station or the tracking area identification information corresponding to the first location information of the UE.

[0169] Based on the second implementation method, as an implementation method, before step 501a, the first base station sends a request message to the UE, where the request message includes indication information, where the indication information is used to indicate at least one of the following:

[0170] 1) UE type, where the UE type indicates that the UE is a VMR-UE co-located with the first base station;

[0171] 2) UE capability, where the UE capability is to establish a wireless backhaul link using a PDU session;

[0172] 3) requesting tracking area identification information available for the first base station;

[0173] 4) Request tracking area identification information associated with the first base station.

[0174] The above step 501a is specifically as follows: the UE sends the request message to the second AMF, the second AMF obtains the first tracking area identification information based on the indication information in the request message, and sends a response message to the UE, where the response message includes the first tracking area identification information.

[0175] The tracking area identification information available for the first base station refers to the tracking area identification information that can be broadcast by the first base station. Requesting the tracking area identification information available for the first base station refers to requesting the second AMF to determine the tracking area identification information that can be broadcast by the first base station. Requesting the tracking area identification information associated with the first base station refers to requesting the second AMF to determine, for the first base station, the tracking area identification information supported by the first base station.

[0176] Exemplarily, the UE sends a request message to the second AMF, which may be: the UE sends uplink data to the UPF, the uplink data includes the request message and the address of the second AMF, so that the UPF sends the request message to the second AMF according to the address of the second AMF. Correspondingly, the second AMF sends a response message to the UE, which may be: the second AMF sends the response message to the UPF, the UPF sends first downlink data to the UE, the first downlink data includes the response message, so that the UE obtains the response message from the first downlink data. For the detailed process of the UE sending a request message to the second AMF, please refer to the description of the embodiment of Figure 4 and will not be repeated here.

[0177] The following introduces two different implementation methods for the second AMF to determine the first tracking area identification information.

[0178] Method a, the second AMF sends a subscription request message to the first AMF, which is used to subscribe to the tracking area identification information supported by the second base station accessed by the UE. The first AMF obtains the first tracking area identification information and sends the first tracking area identification information to the second AMF. The first tracking area identification information is the tracking area identification information supported by the second base station.

[0179] The subscription request message carries the UE ID and the subscribed event type: requesting to subscribe to the tracking area identification information supported by the base station to which the UE is currently accessing. The UE ID can be a Subscription Permanent Identifier (SUPI), a Generic Public Subscription Identifier (GPSI), or a 5G Globally Unique Temporary Identifier (5G-GUTI). The 5G-GUTI is allocated to the UE by the first AMF during the UE registration process and sent to the UE in the registration acceptance message.

[0180] Based on method a, after the above step 503a, if the vehicle moves, and the UE (referring to the VMR-UE) and the first base station (i.e., the VMR-base station) on the vehicle also move, causing the UE to register with a new base station (such as a third base station), the first AMF sends a subscription notification message to the second AMF, and the subscription notification message includes the third tracking area identification information. The third tracking area identification information is the tracking area identification information supported by the third base station accessed by the UE, and then the second AMF sends a configuration update message to the first base station, and the configuration update message includes the third tracking area identification information. After receiving the third tracking area identification information, the first base station can determine the fourth tracking area identification information supported by the first base station based on the third tracking area identification information, or the first base station can determine the fourth tracking area identification information supported by the first base station based on the third tracking area identification information when determining that the third tracking area identification information is different from the first tracking area identification information. Subsequently, the first base station can broadcast the fourth tracking area identification information. Exemplarily, the second AMF sends a configuration update message to the first base station. Specifically, the second AMF sends the configuration update message to the UPF, and the UPF sends second downlink data to the UE, where the second downlink data includes the configuration update message. The UE obtains the configuration update message from the second downlink data and sends the configuration update message to the first base station. This implementation method will be further described in conjunction with Figure 7 below.

[0181] Method b, the second AMF sends a subscription request message to the first AMF, which is used to subscribe to the UE's location information. The first AMF obtains the UE's first location information (i.e., information about the UE's current location) and sends the first location information to the second AMF. The second AMF then obtains the first tracking area identification information corresponding to the first location information.

[0182] The subscription request message carries the UE ID and the subscribed event type: requesting to subscribe to the UE's current geographic location. The UE ID can be SUPI, GPSI, or 5G-GUTI.

[0183] Among them, the second AMF obtains the first tracking area identification information corresponding to the first location information, for example, it can be: the second AMF sends the first location information to the UDM / NEF, and then the UDM / NEF queries the first tracking area identification information corresponding to the first location information, and sends the first tracking area identification information to the second AMF.

[0184] Based on method b, after step 503a above, if the vehicle moves, and the UE (referred to as the VMR-UE) and the first base station (i.e., the VMR-base station) on the vehicle also move, causing the UE to register with a new base station (e.g., a third base station), the first AMF sends a subscription notification message to the second AMF. The subscription notification message includes the second location information of the UE (i.e., information about the current location of the UE). The second AMF then obtains the third tracking area identifier corresponding to the second location information. The third tracking area identifier is the tracking area identifier corresponding to the second location information. The second AMF then sends a configuration update message to the first base station. The configuration update message includes the third tracking area identifier. After receiving the third tracking area identifier, the first base station can determine the fourth tracking area identifier supported by the first base station based on the third tracking area identifier. Alternatively, if the first base station determines that the third tracking area identifier is different from the first tracking area identifier, the first base station can determine the fourth tracking area identifier supported by the first base station based on the third tracking area identifier. Subsequently, the first base station can broadcast the fourth tracking area identifier information. Exemplarily, the second AMF sends a configuration update message to the first base station. Specifically, the second AMF sends the configuration update message to the UPF, and the UPF sends second downlink data to the UE, where the second downlink data includes the configuration update message. The UE obtains the configuration update message from the second downlink data and sends the configuration update message to the first base station. This implementation method will be further described in conjunction with Figure 8 below.

[0185] Implementation method three: the second base station broadcasts the first tracking area identification information, and the UE receives the first tracking area identification information.

[0186] Based on the third implementation method, the first tracking area identification information is specifically tracking area identification information supported by the second base station.

[0187] Based on the third implementation method, after the above step 503a, if the vehicle moves, and the UE (referring to the VMR-UE) and the first base station (i.e., the VMR-base station) on the vehicle also move, causing the UE to register with a new base station (such as a third base station), the third base station broadcasts the third tracking area identification information, and the third tracking area identification information is the tracking area identification information supported by the third base station accessed by the UE, so that the UE receives the third tracking area identification information. The UE then sends the third tracking area identification information to the first base station. After receiving the third tracking area identification information, the first base station can determine the fourth tracking area identification information supported by the first base station based on the third tracking area identification information, or the first base station can determine the fourth tracking area identification information supported by the first base station based on the third tracking area identification information when determining that the third tracking area identification information is different from the first tracking area identification information. Subsequently, the first base station can broadcast the fourth tracking area identification information.

[0188] Figure 5(b) is a flow chart of a communication method provided in an embodiment of the present application. The method is executed by a vehicle-mounted relay device (or a module of a vehicle-mounted relay device), and optionally, further includes other steps executed by a second base station (or a module of a second base station), a first AMF (or a module of a first AMF), and a second AMF (or a module of a second AMF). The second base station here refers to a base station to which the vehicle-mounted relay device accesses (for example, the donor-gNB in ​​Figure 3). The first AMF here refers to the AMF registered by the vehicle-mounted relay device (which can be called VMR-AMF), and the second AMF here refers to the AMF accessed by the vehicle-mounted relay device through a wireless backhaul link. The first AMF and the second AMF are different AMFs. The vehicle-mounted relay device in Figure 5(b) can also be replaced with a WAB device that has both the functions of a UE and a base station.

[0189] In the embodiment of FIG5(b), the vehicle-mounted relay device has both the functions of a UE and a base station.

[0190] The method comprises the following steps:

[0191] Step 501b: The vehicle-mounted relay device obtains first tracking area identification information, which is tracking area identification information supported by the second base station to which the vehicle-mounted relay device accesses, or tracking area identification information corresponding to the first location information of the vehicle-mounted relay device.

[0192] The first tracking area identification information may include at least one TAI and / or at least one TAC.

[0193] The first location information of the vehicle-mounted relay device is used to indicate the current location of the vehicle-mounted relay device. For example, the first location information of the vehicle-mounted relay device is the TAI, cell or other information where the vehicle-mounted relay device is located.

[0194] Step 502b: The vehicle-mounted relay device determines the second tracking area identification information supported by the vehicle-mounted relay device according to the first tracking area identification information.

[0195] The second tracking area identification information determined by the vehicle-mounted relay device may be the same as the first tracking area identification information, or the second tracking area identification information may be a part of the first tracking area identification information.

[0196] After the vehicle-mounted relay device determines the second tracking area identification information, it can broadcast the second tracking area identification information, so that the UE receiving the second tracking area identification information can determine whether it can access the vehicle-mounted relay device, so that the vehicle-mounted relay device can provide services for UEs around the vehicle.

[0197] The above solution can accurately determine the tracking area identification information supported by the vehicle-mounted relay device, so that the vehicle-mounted relay device can better provide services to surrounding UEs, which helps to improve communication quality.

[0198] In the embodiment of Figure 5(b), the specific implementation method for the on-board relay device to obtain the first tracking area identification information is similar to the method for the UE to obtain the first tracking area identification information in the embodiment of Figure 5(a), and reference can be made to the aforementioned description. It can be understood that the functions of the UE and the first base station in the embodiment of Figure 5(a) are both performed by the on-board relay device in the embodiment of Figure 5(b). In other words, the UE and the first base station are considered as a whole, namely the on-board relay device.

[0199] The embodiment of Figure 5(a) is described in detail below in conjunction with the embodiments of Figures 6 to 8. The embodiments of Figures 6 to 8 are described in conjunction with the example of Figure 3. The VMR-UE, VMR-gNB, donor-gNB-1, donor-gNB-2, VMR-AMF, and AMF in the following embodiments are specific examples of the UE, first eNB, second eNB, third eNB, first AMF, and second AMF in the embodiment of Figure 5(a), respectively.

[0200] FIG6 is a flow chart of a communication method provided in an embodiment of the present application. The method includes the following steps:

[0201] Step 601: Configure the subscription information of the VMR-UE on the UDM.

[0202] The contract information includes indication information, which is used to indicate at least one of the following:

[0203] 1) The type of VMR-UE, for example, the UE is a VMR-UE co-located with a gNB or the UE is a vehicle-mounted relay device.

[0204] 2) VMR-UE capabilities, for example, the UE has the ability to establish a wireless backhaul link using a PDU session.

[0205] This step 601 is an optional step.

[0206] In step 602, the VMR-UE sends a NAS request message to the VMR-AMF via donor-gNB-1. In response, the VMR-AMF receives the NAS request message.

[0207] For example, the NAS request message may be a registration request message or a service request message, which is not limited in this application.

[0208] The registration request message is used to request registration with the network, and the service request message is used to request establishment of a link with the network.

[0209] Optionally, the NAS request includes indication information, where the indication information is used to indicate at least one of the following:

[0210] 1) The type of VMR-UE, for example, the UE is a VMR-UE co-located with a gNB or the UE is a vehicle-mounted relay device.

[0211] 2) VMR-UE capabilities, for example, the UE has the ability to establish a wireless backhaul link using a PDU session.

[0212] 3) Request tracking area identification information available for VMR-gNB.

[0213] 4) Request the tracking area identification information associated with the VMR-gNB.

[0214] In this step, donor-gNB-1 selects an AMF for the VMR-UE.

[0215] In step 603, the VMR-AMF determines the tracking area identification information supported by the donor-gNB-1 to which the VMR-UE accesses.

[0216] For example, the VMR-AMF determines that the VMR-UE accesses from donor-gNB-1 and determines the tracking area identifiers supported by donor-gNB-1 based on the donor-gNB-1 ID. The VMR-AMF may obtain the tracking area identifiers supported by donor-gNB-1 during the NG setup process. For example, before step 603, donor-gNB-1 sends the donor-gNB-1 ID and the tracking area identifiers supported by donor-gNB-1 to the VMR-AMF via an NG setup request message.

[0217] The tracking area identification information supported by donor-gNB-1 may include one or more TAIs and / or one or more TACs.

[0218] As an implementation method, the VMR-AMF can determine the type of the VMR-UE based on the indication information in the NAS request message and / or the indication information in the subscription information from the UDM, and then trigger the VMR-AMF to determine the tracking area identification information supported by the donor-gNB-1 accessed by the VMR-UE based on the type of the VMR-UE.

[0219] As another implementation method, the VMR-AMF may determine the capabilities of the VMR-UE based on the indication information in the NAS request message and / or the indication information in the subscription information from the UDM, and then, based on the capabilities of the VMR-UE, trigger the VMR-AMF to determine the tracking area identification information supported by the donor-gNB-1 accessed by the VMR-UE.

[0220] As another implementation method, the VMR-AMF may trigger the determination of the tracking area identification information supported by the donor-gNB-1 to which the VMR-UE accesses based on the indication information in the NAS request message for requesting the tracking area identification information available for the VMR-gNB.

[0221] Step 604: The VMR-AMF sends a NAS response message to the VMR-UE. Correspondingly, the VMR-UE receives the NAS response message.

[0222] The NAS response message includes the tracking area identification information supported by the donor-gNB-1 accessed by the VMR-UE.

[0223] The NAS response message may be a registration acceptance message or a service response message.

[0224] In step 605, the VMR-UE sends the tracking area identifier information supported by the donor-gNB-1 to which the VMR-UE is connected to the VMR-gNB. In response, the VMR-gNB receives the tracking area identifier information supported by the donor-gNB-1 to which the VMR-UE is connected.

[0225] Taking Figure 2 as an example, assuming that the donor-gNB-1 accessed by the VMR-UE is gNB2, and the TAIs supported by gNB2 include TAI-1, TAI-2, and TAI-3, the tracking area identity information received by the VMR-gNB includes TAI-1, TAI-2, and TAI-3.

[0226] In step 606, the VMR-gNB determines the tracking area identification information supported by the VMR-gNB based on the received tracking area identification information.

[0227] Exemplarily, the tracking area identification information supported by the VMR-gNB includes part or all of the tracking area identification information in the received tracking area identification information.

[0228] Exemplarily, the tracking area identification information received by the VMR-gNB includes TAI-1, TAI-2 and TAI-3, and the tracking area identification information supported by the VMR-gNB includes one or more of TAI-1, TAI-2 or TAI-3.

[0229] In step 607, the VMR-gNB initiates the NG Setup process and reports the tracking area identification information supported by the VMR-gNB to the AMF accessed through the N2 wireless backhaul link.

[0230] In this way, the AMF obtains the tracking area identification information supported by the VMR-gNB. Subsequently, the AMF can perform mobility management on the UE accessing the VMR-gNB (the UE is different from the VMR-UE) based on the tracking area identification information supported by the VMR-gNB.

[0231] For example, after the VMR-UE establishes a PDU session for N2 radio link backhaul, the VMR-gNB generates an NG Setup request message, which carries the tracking area identification information supported by the VMR-gNB, and then sends the NG Setup request message to the AMF through the PDU session of the VMR-UE through the process of Figure 4.

[0232] In step 608, the VMR moves, and the donor-gNB accessed by the VMR-UE switches from donor-gNB-1 to donor-gNB-2.

[0233] The VMR moves, which means that the vehicle where the VMR-gNB and VMR-UE are located moves.

[0234] In step 609, the VMR-AMF determines the tracking area identification information supported by the donor-gNB-2 to which the VMR-UE accesses.

[0235] The tracking area identification information supported by donor-gNB-2 may include one or more TAIs and / or one or more TACs.

[0236] In step 610, the VMR-AMF sends a configuration update message to the VMR-UE. In response, the VMR-UE receives the configuration update message.

[0237] The configuration update message includes the tracking area identification information supported by the donor-gNB-2 accessed by the VMR-UE.

[0238] For example, the VMR-AMF determines to send a configuration update message to the VMR-UE based on the type of UE and / or the capability of the UE.

[0239] In step 611, the VMR-UE sends the tracking area identifier information supported by donor-gNB-2 to the VMR-gNB. In response, the VMR-gNB receives the tracking area identifier information supported by donor-gNB-2 to which the VMR-UE is connected.

[0240] Taking Figure 2 as an example, assuming that the donor-gNB-2 accessed by the VMR-UE is gNB2, and the TAIs supported by gNB2 include TAI-3, TAI-4, and TAI-5, the tracking area identity information received by the VMR-gNB includes TAI-3, TAI-4, and TAI-5.

[0241] In step 612, the VMR-gNB determines the tracking area identification information supported by the VMR-gNB based on the received tracking area identification information.

[0242] Exemplarily, the tracking area identification information supported by the VMR-gNB includes part or all of the tracking area identification information in the received tracking area identification information.

[0243] Exemplarily, the tracking area identification information received by the VMR-gNB includes TAI-3, TAI-4 and TAI-5, and the tracking area identification information supported by the VMR-gNB includes one or more of TAI-3, TAI-4 or TAI-5.

[0244] In step 613, if the tracking area identification information supported by the VMR-gNB changes, the VMR-gNB initiates a configuration update process and reports the tracking area identification information supported by the VMR-gNB to the AMF accessed through the N2 wireless backhaul link.

[0245] Among them, the tracking area identification information supported by the VMR-gNB changes, which means that the tracking area identification information determined in step 612 is different from the tracking area identification information locally stored in the VMR-gNB.

[0246] For example, the VMR-gNB generates a configuration update request message that carries the tracking area identification information supported by the VMR-gNB, and then sends the configuration update request message to the AMF through the PDU session of the VMR-UE through the process of Figure 4.

[0247] The above solution determines the tracking area identification information supported by the VMR-gNB based on the tracking area identification information of the donor-gNB currently accessed by the VMR-UE, so as to determine the appropriate tracking area identification information for the VMR-gNB.

[0248] FIG7 is a flow chart of a communication method provided in an embodiment of the present application. The method includes the following steps:

[0249] In step 700, the VMR-UE accesses the core network through the donor-gNB and establishes a PDU session to access the AMF through the N2 wireless backhaul link.

[0250] In step 701, the VMR-gNB sends an NG setup request message to the VMR-UE. In response, the VMR-UE receives the NG setup request message.

[0251] The NG setup request message includes the VMR-UE ID and optionally also includes indication information, where the indication information is used to indicate at least one of the following:

[0252] 1) The type of VMR-UE, for example, the UE is a VMR-UE co-located with a gNB or the UE is a vehicle-mounted relay device.

[0253] 2) VMR-UE capabilities, for example, the UE has the ability to establish a wireless backhaul link using a PDU session.

[0254] 3) Request the tracking area identification information that can be used for the VMR-gNB.

[0255] 4) Request the tracking area identification information associated with the VMR-gNB.

[0256] The VMR-UE ID can be SUPI, GPSI, or 5G-GUTI. The 5G-GUTI is allocated to the VMR-UE by the VMR-AMF during the VMR-UE registration process and sent to the VMR-UE in the registration accept message.

[0257] Step 702: The VMR-UE sends uplink data to the UPF via a PDU session. Correspondingly, the UPF receives the uplink data.

[0258] Among them, the payload of the uplink data includes an NG establishment request message, the source IP address of the uplink data is the IP address of the VMR-UE, and the destination address of the uplink data is the address of the AMF.

[0259] In step 703, the UPF sends an NG setup request message to the AMF based on the destination address in the uplink data. Correspondingly, the AMF receives the NG setup request message.

[0260] Step 704: AMF obtains the identification information of the VMR-AMF corresponding to the VMR-UE ID, that is, the VMR-AMF ID.

[0261] For example, if the VMR-UE ID included in the NG setup request message in step 701 is SUPI or GPSI, the AMF queries the UDM for the identification information of the VMR-AMF corresponding to the VMR-UE ID, i.e., the VMR-AMF ID, based on the SUPI or GPSI. In the VMR-UE registration process, the UDM stores the correspondence between the VMR-UE ID and the identification information of the VMR-AMF.

[0262] Exemplarily, if the VMR-UE ID included in the NG establishment request message of step 701 is 5G-GUTI, the AMF determines the identification information of the VMR-AMF according to the 5G-GUTI, wherein the 5G-GUTI field contains the Globally Unique AMF ID (GUAMI), which can be used to determine the identification information of the VMR-AMF.

[0263] Step 705: AMF sends a subscription request message to VMR-AMF. Correspondingly, VMR-AMF receives the subscription request message.

[0264] This subscription request message is used to subscribe to the tracking area identity information supported by the donor-gNB to which the VMR-UE is currently accessing.

[0265] The subscription request message carries the VMR-UE ID and the subscribed event type, requesting subscription to the tracking area identifier information supported by the donor-gNB to which the VMR-UE is currently connected. The VMR-UE ID can be SUPI, GPSI, or 5G-GUTI.

[0266] In step 706, the VMR-AMF sends the tracking area identification information supported by the donor-gNB-1 to which the VMR-UE is currently connected to the AMF. Accordingly, the AMF receives the tracking area identification information.

[0267] Among them, the tracking area identification information supported by the donor-gNB-1 currently accessed by the VMR-UE may include one or more TAIs and / or one or more TACs.

[0268] In step 707, the AMF sends an NG Setup response message to the UPF. Accordingly, the UPF receives the NG Setup response message.

[0269] The destination address of the NG establishment response message is the IP address of the VMR-UE, and the source address is the address of the AMF.

[0270] The N2 establishment response message includes the tracking area identification information supported by the donor-gNB-1 to which the VMR-UE is currently accessing.

[0271] Taking Figure 2 as an example, assuming that the donor-gNB-1 accessed by the VMR-UE is gNB2, and the TAIs supported by gNB2 include TAI-1, TAI-2, and TAI-3, the tracking area identification information in the N2 establishment response message includes TAI-1, TAI-2, and TAI-3.

[0272] In step 708, the UPF sends downlink data to the VMR-UE via the PDU session, and the VMR-UE receives the downlink data accordingly.

[0273] Among them, the payload of the downlink data includes the NG establishment response message, the source IP address of the downlink data is the address of the AMF, and the destination address of the downlink data is the IP address of the VMR-UE.

[0274] In step 709, the VMR-UE sends an NG Setup Response message to the VMR-gNB. In response, the VMR-gNB receives the NG Setup Response message.

[0275] The VMR-UE receives the downlink data packet, decapsulates it and obtains the NG Setup Response message. If it finds that the NG Setup Response message is not sent to itself, it forwards the NG Setup Response message to the VMR-gNB.

[0276] In step 710, the VMR-gNB determines the tracking area identification information supported by the VMR-gNB based on the tracking area identification information in the NG establishment response message.

[0277] Exemplarily, the tracking area identification information supported by the VMR-gNB includes part or all of the tracking area identification information in the received tracking area identification information.

[0278] Exemplarily, the tracking area identification information received by the VMR-gNB includes TAI-1, TAI-2 and TAI-3, and the tracking area identification information supported by the VMR-gNB includes one or more of TAI-1, TAI-2 or TAI-3.

[0279] In step 711, the VMR moves, and the donor-gNB accessed by the VMR-UE switches from donor-gNB-1 to donor-gNB-2.

[0280] The VMR moves, which means that the vehicle where the VMR-gNB and VMR-UE are located moves.

[0281] Step 712: The VMR-AMF sends a subscription notification message to the AMF. Correspondingly, the AMF receives the subscription notification message.

[0282] The subscription notification message includes the tracking area identification information supported by the donor-gNB-2 to which the VMR-UE is currently accessing.

[0283] Taking Figure 2 as an example, assuming that the donor-gNB-2 accessed by the VMR-UE is gNB2, and the TAIs supported by gNB2 include TAI-3, TAI-4, and TAI-5, the tracking area identity information in the subscription notification message includes TAI-3, TAI-4, and TAI-5.

[0284] Step 713: The AMF sends a configuration update message to the UPF. Correspondingly, the UPF receives the configuration update message.

[0285] The destination address of the configuration update message is the IP address of the VMR-UE, and the source address is the address of the AMF.

[0286] This configuration update message contains the tracking area identification information supported by the donor-gNB-2 to which the VMR-UE is currently accessing.

[0287] Optionally, the AMF sends a configuration update message to the UPF only when it determines that the tracking area identifier information supported by the donor-gNB currently accessed by the VMR-UE has been updated. That is, if the tracking area identifier information supported by the donor-gNB currently accessed by the VMR-UE has not been updated, the configuration update message may not be sent to the UPF. The tracking area identifier information supported by the donor-gNB currently accessed by the VMR-UE has been updated, which means that the tracking area identifier information supported by the donor-gNB-2 currently accessed by the VMR-UE is different from the tracking area identifier information last sent to the VMR-gNB (for example, the tracking area identifier information supported by the donor-gNB-1 currently accessed by the VMR-UE).

[0288] In step 714, the UPF sends downlink data to the VMR-UE via the PDU session, and the VMR-UE receives the downlink data accordingly.

[0289] The payload of the downlink data includes a configuration update message, the source IP address of the downlink data is the address of the AMF, and the destination address of the downlink data is the IP address of the VMR-UE.

[0290] In step 715, the VMR-UE sends a configuration update message to the VMR-gNB. In response, the VMR-gNB receives the configuration update message.

[0291] The VMR-UE receives the downlink data packet, decapsulates it and obtains the configuration update message. If it finds that the configuration update message is not sent to itself, it forwards the configuration update message to the VMR-gNB.

[0292] In step 716, the VMR-gNB determines the tracking area identification information supported by the VMR-gNB based on the tracking area identification information in the configuration update message.

[0293] Exemplarily, the tracking area identification information supported by the VMR-gNB includes part or all of the tracking area identification information in the received tracking area identification information.

[0294] Exemplarily, the tracking area identification information received by the VMR-gNB includes TAI-3, TAI-4 and TAI-5, and the tracking area identification information supported by the VMR-gNB includes one or more of TAI-3, TAI-4 or TAI-5.

[0295] The above solution determines the tracking area identification information supported by the VMR-gNB based on the tracking area identification information of the donor-gNB currently accessed by the VMR-UE, so as to determine the appropriate tracking area identification information for the VMR-gNB.

[0296] FIG8 is a flow chart of a communication method provided in an embodiment of the present application. The method includes the following steps:

[0297] In step 800, the VMR-UE accesses the core network through the donor-gNB and establishes a PDU session to access the AMF through the N2 wireless backhaul link.

[0298] In step 801, the VMR-gNB sends an NG setup request message to the VMR-UE. In response, the VMR-UE receives the NG setup request message.

[0299] The NG setup request message includes the VMR-UE ID and optionally also includes indication information, where the indication information is used to indicate at least one of the following:

[0300] 1) The type of VMR-UE, for example, the UE is a VMR-UE co-located with a gNB or the UE is a vehicle-mounted relay device.

[0301] 2) VMR-UE capabilities, for example, the UE has the ability to establish a wireless backhaul link using a PDU session.

[0302] 3) Request tracking area identification information available for VMR-gNB.

[0303] 4) Request the tracking area identification information associated with the VMR-gNB.

[0304] The VMR-UE ID can be SUPI, GPSI, or 5G-GUTI. The 5G-GUTI is allocated to the VMR-UE by the VMR-AMF during the VMR-UE registration process and sent to the VMR-UE in the registration accept message.

[0305] Step 802: The VMR-UE sends uplink data to the UPF via a PDU session. Correspondingly, the UPF receives the uplink data.

[0306] Among them, the payload of the uplink data includes an NG establishment request message, the source IP address of the uplink data is the IP address of the VMR-UE, and the destination address of the uplink data is the address of the AMF.

[0307] In step 803, the UPF sends an NG setup request message to the AMF based on the destination address in the uplink data. Correspondingly, the AMF receives the NG setup request message.

[0308] Step 804: AMF obtains the identification information of the VMR-AMF corresponding to the VMR-UE ID, that is, the VMR-AMF ID.

[0309] For example, if the VMR-UE ID included in the NG setup request message in step 801 is SUPI or GPSI, the AMF queries the UDM for the identification information of the VMR-AMF corresponding to the VMR-UE ID, i.e., the VMR-AMF ID, based on the SUPI or GPSI. In the VMR-UE registration process, the UDM stores the correspondence between the VMR-UE ID and the identification information of the VMR-AMF.

[0310] Exemplarily, if the VMR-UE ID included in the NG establishment request message of step 801 is 5G-GUTI, the AMF determines the identification information of the VMR-AMF according to the 5G-GUTI, wherein the 5G-GUTI field contains the Globally Unique AMF ID (GUAMI), which can be used to determine the identification information of the VMR-AMF.

[0311] Step 805: AMF sends a subscription request message to VMR-AMF. Correspondingly, VMR-AMF receives the subscription request message.

[0312] The subscription request message is used to subscribe to the current geographical location of the VMR-UE.

[0313] The subscription request message carries the VMR-UE ID and the subscribed event type: requesting to subscribe to the current geographic location of the VMR-UE. The VMR-UE ID can be SUPI, GPSI, or 5G-GUTI.

[0314] Step 806: The VMR-AMF sends the current geographic location 1 of the VMR-UE to the AMF. Accordingly, the AMF receives the current geographic location 1 of the VMR-UE.

[0315] Among them, the VMR-AMF can initiate a positioning process for the VMR-UE, thereby obtaining the current geographical location 1 of the VMR-UE.

[0316] Step 807: The AMF obtains the tracking area identification information corresponding to the current geographical location of the VMR-UE from the NEF.

[0317] For example, the AMF sends a request message to the NEF, carrying the current geographic location 1 of the VMR-UE. The NEF determines the tracking area identification information mapped to the geographic location 1 based on the current geographic location of the VMR-UE.

[0318] In step 808, the AMF sends an NG setup response message to the UPF. Accordingly, the UPF receives the NG setup response message.

[0319] The destination address of the NG establishment response message is the IP address of the VMR-UE, and the source address is the address of the AMF.

[0320] The N2 establishment response message includes the tracking area identification information corresponding to the current geographical location 1 of the VMR-UE.

[0321] In step 809, the UPF sends downlink data to the VMR-UE via the PDU session, and the VMR-UE receives the downlink data accordingly.

[0322] Among them, the payload of the downlink data includes the NG establishment response message, the source IP address of the downlink data is the address of the AMF, and the destination address of the downlink data is the IP address of the VMR-UE.

[0323] In step 810, the VMR-UE sends an NG Setup Response message to the VMR-gNB. In response, the VMR-gNB receives the NG Setup Response message.

[0324] The VMR-UE receives the downlink data packet, decapsulates it and obtains the NG Setup Response message. If it finds that the NG Setup Response message is not sent to itself, it forwards the NG Setup Response message to the VMR-gNB.

[0325] In step 811, the VMR-gNB determines the tracking area identification information supported by the VMR-gNB based on the tracking area identification information in the NG establishment response message.

[0326] Exemplarily, the tracking area identification information supported by the VMR-gNB includes part or all of the tracking area identification information in the received tracking area identification information.

[0327] Exemplarily, the tracking area identification information received by the VMR-gNB includes TAI-1, TAI-2 and TAI-3, and the tracking area identification information supported by the VMR-gNB includes one or more of TAI-1, TAI-2 or TAI-3.

[0328] Step 812: The VMR moves, and the current geographical location of the VMR-UE is updated from geographical location 1 to geographical location 2.

[0329] The VMR moves, which means that the vehicle where the VMR-gNB and VMR-UE are located moves.

[0330] Step 813: The VMR-AMF sends a subscription notification message to the AMF. Correspondingly, the AMF receives the subscription notification message.

[0331] The subscription notification message includes the current geographical location 2 of the VMR-UE.

[0332] In step 814, the AMF sends a configuration update message to the UPF. Accordingly, the UPF receives the configuration update message.

[0333] The destination address of the configuration update message is the IP address of the VMR-UE, and the source address is the address of the AMF.

[0334] The configuration update message includes the tracking area identification information corresponding to the geographical location 2 where the VMR-UE is currently located.

[0335] Optionally, the AMF sends a configuration update message to the UPF only when it determines that the tracking area identification information corresponding to the current geographical location of the VMR-UE has been updated. That is, if the tracking area identification information corresponding to the current geographical location of the VMR-UE has not been updated, the configuration update message may not be sent to the UPF. Among them, the tracking area identification information corresponding to the current geographical location of the VMR-UE has been updated, which means that the tracking area identification information corresponding to the current geographical location 2 of the VMR-UE is different from the tracking area identification information last sent to the VMR-gNB (such as the tracking area identification information corresponding to the current geographical location 1 of the VMR-UE).

[0336] In step 815, the UPF sends downlink data to the VMR-UE via the PDU session, and the VMR-UE receives the downlink data accordingly.

[0337] The payload of the downlink data includes a configuration update message, the source IP address of the downlink data is the address of the AMF, and the destination address of the downlink data is the IP address of the VMR-UE.

[0338] In step 816, the VMR-UE sends a configuration update message to the VMR-gNB. In response, the VMR-gNB receives the configuration update message.

[0339] The VMR-UE receives the downlink data packet, decapsulates it and obtains the configuration update message. If it finds that the configuration update message is not sent to itself, it forwards the configuration update message to the VMR-gNB.

[0340] In step 817, the VMR-gNB determines the tracking area identification information supported by the VMR-gNB based on the tracking area identification information in the configuration update message.

[0341] Exemplarily, the tracking area identification information supported by the VMR-gNB includes part or all of the tracking area identification information in the received tracking area identification information.

[0342] Exemplarily, the tracking area identification information received by the VMR-gNB includes TAI-3, TAI-4 and TAI-5, and the tracking area identification information supported by the VMR-gNB includes one or more of TAI-3, TAI-4 or TAI-5.

[0343] The above solution determines the tracking area identification information supported by the VMR-gNB based on the tracking area identification information corresponding to the current geographical location of the VMR-UE, so as to determine the appropriate tracking area identification information for the VMR-gNB.

[0344] It is understandable that in order to implement the functions in the above embodiments, the first access network device, the terminal device, the second mobility management network element or the vehicle-mounted relay device includes hardware structures and / or software modules corresponding to the execution of each function. It should be easily appreciated by those skilled in the art that, in combination with the units and method steps of each example described in the embodiments disclosed in this application, this application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0345] Figures 9 and 10 are schematic diagrams of the structures of possible communication devices provided in the embodiments of the present application. These communication devices can be used to implement the functions of the first access network device, terminal device, second mobility management network element or vehicle-mounted relay device in the above-mentioned method embodiments, and thus can also achieve the beneficial effects possessed by the above-mentioned method embodiments. In the embodiments of the present application, the communication device can be a first access network device, a terminal device, a second mobility management network element or a vehicle-mounted relay device, and can also be a module (such as a chip) applied to the first access network device, the terminal device, the second mobility management network element or the vehicle-mounted relay device.

[0346] The communication device 900 shown in Figure 9 includes a processing unit 910 and a transceiver unit 920. The communication device 900 is used to implement the functions of the first access network device, terminal device, second mobility management network element or vehicle-mounted relay device in the above method embodiment.

[0347] When the communication device 900 is used to implement the function of the first access network device in the above method embodiment, the transceiver unit 920 is used to receive first tracking area identification information from the terminal device, where the first tracking area identification information is tracking area identification information supported by the second access network device accessed by the terminal device, or is tracking area identification information corresponding to the first location information of the terminal device; the processing unit 910 is used to determine the second tracking area identification information supported by the first access network device based on the first tracking area identification information; wherein the terminal device and the first access network device constitute a vehicle-mounted relay device.

[0348] In a possible implementation method, the transceiver unit 920 is further used to send a request message to the terminal device before receiving the first tracking area identification information from the terminal device, and the request message is used to trigger the terminal device to obtain the first tracking area identification information.

[0349] In one possible implementation method, the request message includes indication information, and the indication information is used to indicate at least one of the following: the type of the terminal device, the type of the terminal device indicates that the terminal device is a vehicle-mounted relay terminal device jointly installed with the first access network device; the capability of the terminal device, the capability of the terminal device is to use a PDU session to establish a wireless backhaul link; a request for tracking area identification information that can be used for the first access network device; and a request for tracking area identification information associated with the first access network device.

[0350] In one possible implementation method, the transceiver unit 920 is also used to receive third tracking area identification information from the terminal device after the processing unit 910 determines the second tracking area identification information supported by the first access network device based on the first tracking area identification information. The third tracking area identification information is the tracking area identification information supported by the third access network device to which the terminal device accesses, or is the tracking area identification information corresponding to the second location information of the terminal device.

[0351] In a possible implementation method, the processing unit 910 is further configured to determine fourth tracking area identification information supported by the first access network device based on the third tracking area identification information.

[0352] In one possible implementation method, the processing unit 910 is used to determine the fourth tracking area identification information supported by the first access network device based on the third tracking area identification information, specifically including: when the third tracking area identification information is different from the first tracking area identification information, determining the fourth tracking area identification information supported by the first access network device based on the third tracking area identification information.

[0353] When the communication device 900 is used to implement the function of the terminal device in the above method embodiment, the processing unit 910 is used to obtain first tracking area identification information, where the first tracking area identification information is tracking area identification information supported by the second access network device to which the terminal device accesses, or is tracking area identification information corresponding to the first location information of the terminal device; the transceiver unit 920 is used to send the first tracking area identification information to the first access network device, where the first tracking area identification information is used to determine the second tracking area identification information supported by the first access network device; wherein the terminal device and the first access network device constitute a vehicle-mounted relay device.

[0354] In one possible implementation method, the processing unit 910 is used to obtain the first tracking area identification information, specifically including: sending a NAS request message to the first mobility management network element through the transceiver unit 920, where the first mobility management network element is the mobility management network element registered by the terminal device; and receiving a NAS response message from the first mobility management network element, where the NAS response message includes the first tracking area identification information.

[0355] In one possible implementation method, the NAS request message also includes indication information, and the indication information is used to indicate at least one of the following: the type of the terminal device, the type of the terminal device indicates that the terminal device is a vehicle-mounted relay terminal device jointly installed with the first access network device; the capability of the terminal device, the capability of the terminal device is to use a PDU session to establish a wireless backhaul link; a request for tracking area identification information that can be used for the first access network device; and a request for tracking area identification information associated with the first access network device.

[0356] In one possible implementation method, the transceiver unit 920 is also used to receive a configuration update message from the first mobility management network element, where the configuration update message includes third tracking area identification information, where the third tracking area identification information is the tracking area identification information supported by the third access network device to which the terminal device accesses, or is the tracking area identification information corresponding to the second location information of the terminal device; and the third tracking area identification information is sent to the first access network device, where the third tracking area identification information is used to determine the fourth tracking area identification information supported by the first access network device.

[0357] In one possible implementation method, the transceiver unit 920 is also used to receive a request message from the first access network device before obtaining the first tracking area identification information, and the request message includes indication information, and the indication information is used to request tracking area identification information that can be used for the first access network device; the processing unit 910 is used to obtain the first tracking area identification information, specifically including: sending the request message to the second mobility management network element, the second mobility management network element is the mobility management network element accessed by the first access network device through the wireless backhaul link; receiving a response message from the second mobility management network element, and the response message includes the first tracking area identification information.

[0358] In one possible implementation method, the processing unit 910 is used to send the request message to the second mobility management network element through the transceiver unit 920, specifically including: sending uplink data to the user plane network element through the transceiver unit 920, the uplink data including the request message and the address of the second mobility management network element, and the request message is forwarded by the user plane network element to the second mobility management network element; the processing unit 910 is used to receive a response message from the second mobility management network element through the transceiver unit 920, specifically including: receiving first downlink data from the user plane network element through the transceiver unit 920, the first downlink data including the response message, and the response message in the first downlink data comes from the second mobility management network element.

[0359] In one possible implementation method, the transceiver unit 920 is also used to receive second downlink data from the user plane network element, where the first downlink data includes a configuration update message, and the configuration update message includes third tracking area identification information, where the third tracking area identification information is the tracking area identification information supported by the third access network device to which the terminal device accesses, or is the tracking area identification information corresponding to the second location information of the terminal device; and the configuration update message is sent to the first access network device, where the third tracking area identification information in the configuration update message is used to determine the fourth tracking area identification information supported by the first access network device.

[0360] When the communication device 900 is used to implement the function of the second mobility management network element in the above method embodiment, the transceiver unit 920 is configured to receive a request message from the first access network device, where the request message includes indication information, where the indication information is used to indicate at least one of the following: The type of the terminal device, the type of the terminal device indicates that the terminal device is an on-vehicle relay terminal device jointly set up with the first access network device; the capability of the terminal device, the capability of the terminal device is to be able to use PDU sessions to establish a wireless backhaul link; request tracking area identification information that can be used for the first access network device; request tracking area identification information associated with the first access network device; processing unit 910 is used to obtain first tracking area identification information according to the indication information, the first tracking area identification information is the tracking area identification information supported by the second access network device accessed by the terminal device, or the tracking area identification information corresponding to the first location information of the terminal device; transceiver unit 920 is also used to send a response message to the first access network device, the response message includes the first tracking area identification information, the first tracking area identification information is used to determine the second tracking area identification information supported by the first access network device; wherein the terminal device and the first access network device constitute a on-vehicle relay device, and the second mobility management network element is the mobility management network element accessed by the first access network device through the wireless backhaul link.

[0361] In one possible implementation method, the transceiver unit 920 is used to receive a request message from the first access network device, specifically including: receiving the request message from the first access network device through the user plane network element; the transceiver unit 920 is used to send a response message to the first access network device, specifically including: sending the response message to the first access network device through the user plane network element.

[0362] In one possible implementation method, the processing unit 910 is used to obtain the first tracking area identification information, specifically including: sending a subscription request message to the first mobility management network element through the transceiver unit 920, wherein the subscription request message is used to subscribe to the tracking area identification information supported by the second access network device accessed by the terminal device, and the first mobility management network element is the mobility management network element registered by the terminal device; and receiving the first tracking area identification information from the first mobility management network element.

[0363] In one possible implementation method, the transceiver unit 920 is also used to receive a subscription notification message from the first mobility management network element, where the subscription notification message includes third tracking area identification information, and the third tracking area identification information is the tracking area identification information supported by the third access network device to which the terminal device accesses; and to send a configuration update message to the first access network device, where the configuration update message includes the third tracking area identification information, and the third tracking area identification information is used to determine the fourth tracking area identification information supported by the first access network device.

[0364] In one possible implementation method, the processing unit 910 is used to obtain the first tracking area identification information, specifically including: sending a subscription request message to the first mobility management network element through the transceiver unit 920, wherein the subscription request message is used to subscribe to the location information of the terminal device, and the first mobility management network element is the mobility management network element registered by the terminal device; receiving the first location information of the terminal device from the mobility management network element; and obtaining the first tracking area identification information corresponding to the first location information.

[0365] In one possible implementation method, the processing unit 910 is used to obtain the first tracking area identification information corresponding to the first location information, specifically including: sending the first location information to the network open network element through the transceiver unit 920; receiving the first tracking area identification information from the network open network element.

[0366] In one possible implementation method, the transceiver unit 920 is also used to receive a subscription notification message from the first mobility management network element, and the subscription notification message includes the second location information of the terminal device; the processing unit 910 is also used to obtain the third tracking area identification information corresponding to the second location information, and the third tracking area identification information is the tracking area identification information corresponding to the second location information; the transceiver unit 920 is also used to send a configuration update message to the first access network device, and the configuration update message includes the third tracking area identification information, and the third tracking area identification information is used to determine the fourth tracking area identification information supported by the first access network device.

[0367] When the communication device 900 is used to implement the function of the second mobility management network element in the above method embodiment, the transceiver unit 920 is used to send the first location information of the terminal device to the network open network element; receive the first tracking area identification information corresponding to the first location information from the network open network element; and send the first tracking area identification information to the terminal device.

[0368] When the communication device 900 is used to implement the function of the vehicle-mounted relay device in the above method embodiment, the processing unit 910 is used to obtain first tracking area identification information, where the first tracking area identification information is tracking area identification information supported by the second access network device to which the vehicle-mounted relay device accesses, or is tracking area identification information corresponding to the first location information of the vehicle-mounted relay device; and based on the first tracking area identification information, the second tracking area identification information supported by the vehicle-mounted relay device is determined.

[0369] In one possible implementation method, the processing unit 910 is used to obtain the first tracking area identification information, specifically including: sending a NAS request message to the first mobility management network element through the transceiver unit 920, where the first mobility management network element is the mobility management network element registered with the vehicle-mounted relay device; and receiving a NAS response message from the first mobility management network element, where the NAS response message includes the first tracking area identification information.

[0370] In one possible implementation method, the NAS request message also includes indication information, and the indication information is used to indicate at least one of the following: the type of the vehicle-mounted relay device, the type of the vehicle-mounted relay device indicates a vehicle-mounted relay terminal device that is equipped with a vehicle-mounted terminal device and a vehicle-mounted access network device; the capability of the vehicle-mounted relay device, the capability of the vehicle-mounted relay device is to be able to establish a wireless backhaul link using a PDU session; a request for tracking area identification information that can be used for the vehicle-mounted relay device; and a request for tracking area identification information associated with the vehicle-mounted relay device.

[0371] In one possible implementation method, the transceiver unit 920 is also used to receive a configuration update message from the first mobility management network element, and the configuration update message includes third tracking area identification information, and the third tracking area identification information is the tracking area identification information supported by the third access network device to which the vehicle-mounted relay device accesses, or the tracking area identification information corresponding to the second location information of the vehicle-mounted relay device.

[0372] In one possible implementation method, the processing unit 910 is used to obtain the first tracking area identification information, specifically including: sending a request message to the second mobility management network element through the transceiver unit 920, the request message including indication information, the indication information being used to indicate at least one of the following: the type of the vehicle-mounted relay device, the type of the vehicle-mounted relay device indicating a vehicle-mounted relay terminal device that is equipped with a vehicle-mounted terminal device and a vehicle-mounted access network device; the capability of the vehicle-mounted relay device, the capability of the vehicle-mounted relay device is to have the ability to establish a wireless backhaul link using a PDU session; requesting tracking area identification information that can be used for the vehicle-mounted relay device; requesting tracking area identification information associated with the vehicle-mounted relay device; receiving a response message from the second mobility management network element, the response message including the first tracking area identification information.

[0373] In one possible implementation method, the processing unit 910 is used to send the request message to the second mobility management network element through the transceiver unit 920, specifically including: sending uplink data to the user plane network element through the transceiver unit 920, the uplink data including the request message and the address of the second mobility management network element, and the request message is forwarded by the user plane network element to the second mobility management network element; the processing unit 910 is used to receive a response message from the second mobility management network element through the transceiver unit 920, specifically including: receiving first downlink data from the user plane network element through the transceiver unit 920, the first downlink data including the response message, and the response message in the first downlink data comes from the second mobility management network element.

[0374] In one possible implementation method, the transceiver unit 920 is also used to receive second downlink data from the user plane network element, where the first downlink data includes a configuration update message, and the configuration update message includes third tracking area identification information, where the third tracking area identification information is the tracking area identification information supported by the third access network device to which the vehicle-mounted relay device accesses, or is the tracking area identification information corresponding to the second location information of the vehicle-mounted relay device.

[0375] In a possible implementation method, the processing unit 910 is further configured to determine fourth tracking area identification information supported by the vehicle-mounted relay device according to the third tracking area identification information.

[0376] In one possible implementation method, the processing unit 910 is used to determine the fourth tracking area identification information supported by the vehicle-mounted relay device based on the third tracking area identification information, specifically including: when the third tracking area identification information is different from the first tracking area identification information, determining the fourth tracking area identification information supported by the vehicle-mounted relay device based on the third tracking area identification information.

[0377] For a more detailed description of the processing unit 910 and the transceiver unit 920, reference can be made to the relevant description in the above method embodiment, which will not be repeated here.

[0378] The communication device 1000 shown in Figure 10 includes a processor 1010 and an interface circuit 1020. The processor 1010 and the interface circuit 1020 are coupled to each other. It is understood that the interface circuit 1020 can be a transceiver or an input / output interface. Optionally, the communication device 1000 may also include a memory 1030 for storing instructions executed by the processor 1010, or storing input data required by the processor 1010 to execute instructions, or storing data generated after the processor 1010 executes instructions.

[0379] When the communication device 1000 is used to implement the above method embodiment, the processor 1010 is used to implement the functions of the above processing unit 910 , and the interface circuit 1020 is used to implement the functions of the above transceiver unit 920 .

[0380] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0381] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disk, mobile hard disk, compact disc read-only memory (CD-ROM) or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a first access network device, a terminal device, a second mobility management network element or an on-board relay device. Of course, the processor and the storage medium can also exist as discrete components in the access network device or the terminal.

[0382] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. A computer program refers to a set of instructions that instruct an electronic computer or other device with message processing capabilities to perform each step of the action, usually written in a certain programming language and running on a certain target architecture. When the computer program or instruction is loaded and executed on a computer, the process or function described in the embodiment of the present application is executed in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network or other programmable device. The computer program or instruction can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer program or instruction can be transmitted from one website, computer, server or data center to another website, computer, server or data center by wired or wireless means. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium, such as a floppy disk, a hard disk, or a magnetic tape; an optical medium, such as a digital video disk; or a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or may include both volatile and non-volatile types of storage media.

[0383] In the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0384] In this application, "at least one" means one or more, and "more" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. In the text description of this application, the character " / " generally indicates that the previous and next related objects are in an "or" relationship; in the formulas of this application, the character " / " indicates that the previous and next related objects are in a "division" relationship.

[0385] It is understood that the various numbers used in the embodiments of this application are merely for ease of description and are not intended to limit the scope of the embodiments of this application. The order of the sequence numbers of the above-mentioned processes does not necessarily imply a specific order of execution; the order of execution of the processes should be determined by their functions and inherent logic.

Claims

1. A communication method, characterized in that: Applied to the first access network device or the module of the first access network device, the method comprises: Receiving first tracking area identification information from a terminal device, where the first tracking area identification information is tracking area identification information supported by a second access network device accessed by the terminal device, or is tracking area identification information corresponding to first location information of the terminal device; Determine, according to the first tracking area identification information, second tracking area identification information supported by the first access network device; Among them, the terminal device and the first access network device constitute a vehicle-mounted relay device.

2. The method according to claim 1, characterized in that Before receiving the first tracking area identification information from the terminal device, the method further includes: A request message is sent to the terminal device, where the request message is used to trigger the terminal device to obtain the first tracking area identification information.

3. The method according to claim 2, characterized in that The request message includes indication information, where the indication information is used to indicate at least one of the following: The type of the terminal device, where the type of the terminal device indicates that the terminal device is a vehicle-mounted relay terminal device jointly provided with the first access network device; The capability of the terminal device is to establish a wireless backhaul link using a protocol data unit (PDU) session; Requesting tracking area identification information that can be used for the first access network device; Request tracking area identification information associated with the first access network device.

4. The method according to any one of claims 1 to 3, characterized in that After determining, according to the first tracking area identification information, the second tracking area identification information supported by the first access network device, the method further includes: Receive third tracking area identification information from the terminal device, where the third tracking area identification information is tracking area identification information supported by a third access network device to which the terminal device accesses, or is tracking area identification information corresponding to the second location information of the terminal device.

5. The method according to claim 4, characterized in that The method further comprises: According to the third tracking area identification information, determine the fourth tracking area identification information supported by the first access network device.

6. The method according to claim 5, characterized in that The determining, according to the third tracking area identification information, fourth tracking area identification information supported by the first access network device includes: In a case where the third tracking area identification information is different from the first tracking area identification information, the fourth tracking area identification information supported by the first access network device is determined according to the third tracking area identification information.

7. A communication method, characterized in that: Applied to a terminal device or a module of a terminal device, the method comprises: Acquire first tracking area identification information, where the first tracking area identification information is tracking area identification information supported by a second access network device accessed by the terminal device, or is tracking area identification information corresponding to the first location information of the terminal device; Sending the first tracking area identification information to the first access network device, where the first tracking area identification information is used to determine the second tracking area identification information supported by the first access network device; Among them, the terminal device and the first access network device constitute a vehicle-mounted relay device.

8. The method according to claim 7, characterized in that The obtaining the first tracking area identification information includes: Sending a non-access layer NAS request message to a first mobility management network element, where the first mobility management network element is the mobility management network element registered by the terminal device; A NAS response message is received from the first mobility management network element, where the NAS response message includes the first tracking area identification information.

9. The method according to claim 8, characterized in that The NAS response message further includes indication information, where the indication information is used to indicate at least one of the following: The type of the terminal device, where the type of the terminal device indicates that the terminal device is a vehicle-mounted relay terminal device jointly provided with the first access network device; The capability of the terminal device is to establish a wireless backhaul link using a protocol data unit (PDU) session; Requesting tracking area identification information that can be used for the first access network device; Request tracking area identification information associated with the first access network device.

10. The method according to claim 8 or 9, characterized in that The method further comprises: receiving a configuration update message from the first mobility management network element, the configuration update message including third tracking area identification information, the third tracking area identification information being tracking area identification information supported by a third access network device accessed by the terminal device, or being tracking area identification information supported by the third access network device accessed by the terminal device. Tracking area identification information corresponding to the second location information of the terminal device; The third tracking area identification information is sent to the first access network device, where the third tracking area identification information is used to determine the fourth tracking area identification information supported by the first access network device.

11. The method according to claim 7, characterized in that Before obtaining the first tracking area identification information, the method further includes: Receive a request message from the first access network device, the request message including indication information, the indication information being used to indicate at least one of the following: the type of the terminal device, the type of the terminal device indicating that the terminal device is a vehicle-mounted relay terminal device jointly provided with the first access network device; the capability of the terminal device, the capability of the terminal device being the ability to establish a wireless backhaul link using a protocol data unit (PDU) session; requesting tracking area identification information that can be used for the first access network device; requesting tracking area identification information associated with the first access network device; The obtaining the first tracking area identification information includes: Sending the request message to a second mobility management network element, where the second mobility management network element is a mobility management network element accessed by the first access network device through a wireless backhaul link; A response message is received from the second mobility management network element, where the response message includes the first tracking area identification information.

12. The method according to claim 11, characterized in that The sending the request message to the second mobility management network element includes: Sending uplink data to a user plane network element, the uplink data including the request message and the address of the second mobility management network element, the request message being forwarded by the user plane network element to the second mobility management network element; The receiving a response message from the second mobility management network element includes: Receive first downlink data from the user plane network element, where the first downlink data includes the response message, and the response message in the first downlink data comes from the second mobility management network element.

13. The method according to claim 12, characterized in that The method further comprises: receiving second downlink data from the user plane network element, where the first downlink data includes a configuration update message, where the configuration update message includes third tracking area identification information, where the third tracking area identification information is tracking area identification information supported by a third access network device accessed by the terminal device, or is tracking area identification information corresponding to the second location information of the terminal device; The configuration update message is sent to the first access network device, and the third tracking area identification information in the configuration update message is used to determine the fourth tracking area identification information supported by the first access network device.

14. A communication method, characterized in that: Applied to the second mobility management network element or a module of the second mobility management network element, the method comprising: Receive a request message from a first access network device, the request message including indication information, the indication information being used to indicate at least one of the following: a type of terminal device, the type of terminal device indicating that the terminal device is a vehicle-mounted relay terminal device co-installed with the first access network device; a capability of the terminal device, the capability of the terminal device being the ability to establish a wireless backhaul link using a protocol data unit (PDU) session; requesting tracking area identification information that can be used for the first access network device; requesting tracking area identification information associated with the first access network device; According to the indication information, first tracking area identification information is acquired, where the first tracking area identification information is tracking area identification information supported by a second access network device accessed by the terminal device, or is tracking area identification information corresponding to the first location information of the terminal device; Sending a response message to the first access network device, where the response message includes the first tracking area identification information, where the first tracking area identification information is used to determine the second tracking area identification information supported by the first access network device; Among them, the terminal device and the first access network device constitute a vehicle-mounted relay device, and the second mobility management network element is a mobility management network element accessed by the first access network device through a wireless backhaul link.

15. The method according to claim 14, characterized in that The receiving a request message from the first access network device includes: Receiving the request message from the first access network device through a user plane network element; The sending a response message to the first access network device includes: The response message is sent to the first access network device through the user plane network element.

16. The method according to claim 14 or 15, characterized in that The obtaining the first tracking area identification information includes: Sending a subscription request message to a first mobility management network element, where the subscription request message is used to subscribe to the tracking area identification information supported by the second access network device accessed by the terminal device, and the first mobility management network element is the mobility management network element registered by the terminal device; Receive the first tracking area identification information from the first mobility management network element.

17. The method according to claim 16, characterized in that The method further comprises: receiving a subscription notification message from the first mobility management network element, where the subscription notification message includes third tracking area identification information, where the third tracking area identification information is tracking area identification information supported by a third access network device accessed by the terminal device; A configuration update message is sent to the first access network device, where the configuration update message includes the third tracking area identification information, and the third tracking area identification information is used to determine the fourth tracking area identification information supported by the first access network device.

18. The method of claim 14, wherein: The obtaining the first tracking area identification information includes: Sending a subscription request message to a first mobility management network element, where the subscription request message is used to subscribe to the location information of the terminal device, and the first mobility management network element is the mobility management network element with which the terminal device is registered; Receiving first location information of the terminal device from the mobility management network element; Obtain the first tracking area identification information corresponding to the first location information.

19. The method according to claim 18, characterized in that The acquiring the first tracking area identification information corresponding to the first location information includes: Sending the first location information to a network open network element; Receive the first tracking area identification information from the network open network element.

20. The method according to claim 18 or 19, characterized in that The method further comprises: receiving a subscription notification message from the first mobility management network element, where the subscription notification message includes the second location information of the terminal device; Acquire third tracking area identification information corresponding to the second location information, where the third tracking area identification information is the tracking area identification information corresponding to the second location information; A configuration update message is sent to the first access network device, where the configuration update message includes the third tracking area identification information, and the third tracking area identification information is used to determine the fourth tracking area identification information supported by the first access network device.

21. A communication device, characterized in that: Comprising a module for executing the method of any one of claims 1 to 6, or the method of any one of claims 7 to 13, or the method of any one of claims 14 to 20.

22. A communication device, characterized in that: The invention comprises a processor and an interface circuit, wherein the processor is used to communicate with other devices through the interface circuit and execute the method described in any one of claims 1 to 6, or the method described in any one of claims 7 to 13, or the method described in any one of claims 14 to 20.

23. A computer program product, characterized in that The computer program product comprises instructions, which, when executed on a processor, cause the processor to perform the method of any one of claims 1 to 6, or the method of any one of claims 7 to 13, or the method of any one of claims 14 to 20.

24. A computer-readable storage medium, characterized in that: The storage medium stores a computer program or instruction. When the computer program or instruction is executed by the communication device, the method described in any one of claims 1 to 6, or the method described in any one of claims 7 to 13, or the method described in any one of claims 14 to 20 is implemented.

25. A communication system, characterized in that: It comprises a first access network device for executing the method as claimed in any one of claims 1 to 6, and a terminal device for executing the method as claimed in any one of claims 7 to 13.

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