Communication method and related apparatus

Abstract

Provided in the present application are a communication method and a related apparatus, which can be used in the technical field of communications. In the technical solution provided in the present application, a first network element may acquire MBS serving area information, the MBS serving area information comprising M mapping cell identifiers; the first network element may send an MBS session establishment request to a first access network device, the MBS session establishment request being used for requesting that a first session is established; and a mapping cell identifier currently corresponding to a cell of the first access network device includes at least one of the M mapping cell identifiers. In addition, the first network element may further receive first response information from the first access network device, which first response information is used for indicating that the first access network device successfully establishes a first session or fails to establish the first session. The method of the present application can solve the problem in the prior art of it not being possible for an access network device to accurately provide an MBS to a UE.

Description

Communication method and related device

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on August 31, 2023, with application number 202311134295.7 and application name “Communication Methods and Related Devices”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to communication methods and related devices. Background Art

[0003] Multicast and broadcast service (MBS) is a service targeted at multiple user equipment (UE), such as live broadcast services, public safety services, and batch software updates. MBS data can be associated with an MBS service area. MBS data is typically sent only to UEs within a defined geographic area. An MBS service area encompasses all or part of the cells of a base station covering that defined geographic area. In other words, MBS data is typically sent only to UEs located within the MBS service area.

[0004] A method for sending MBS data to a UE located within an MBS service area is as follows: a core network device receives MBS data and an MBS service request from a data server, determines an MBS service area associated with the MBS data based on the MBS service request, and sends an MBS session establishment request to an access network device whose coverage includes the MBS service area. The MBS session establishment request may include MBS service area information, which is used to indicate the MBS service area associated with the MBS session. Accordingly, the access network device receives the MBS session request and establishes an MBS session based on the MBS session request. After the access network device successfully establishes the MBS session, the core network device sends the MBS data to the access network device. After receiving the MBS data, the access network device may send the MBS data to at least one cell. When there are multiple MBS service areas, the MBS data sent by cells in different MBS service areas may be different.

[0005] In the NTN network, satellites, aircraft and other devices can be used as access network devices to transmit data. However, when the access network devices in the NTN network use the above method to transmit MBS data, there may be a problem that the access network devices cannot accurately provide MBS services to the UE.

[0006] Summary of the Invention

[0007] The present application provides a communication method and related apparatus for solving the problem in the prior art that access network equipment cannot accurately provide MBS services to UE.

[0008] In a first aspect, the present application provides a communication method, which is applied to a first network element. The method includes: obtaining multicast broadcast service (MBS) service area information, the MBS service area information including M mapped cell identifiers, the M mapped cell identifiers including a mapped cell identifier corresponding to each access network device in a first geographical area among multiple access network devices, the first geographical area being a geographical area associated with a first session, and M being a positive integer; sending an MBS session establishment request to a first access network device among the multiple access network devices based on the MBS service area information, the MBS session establishment request being used to request establishment of the first session, the mapped cell identifier currently corresponding to a cell of the first access network device including at least one of the M mapped cell identifiers; and receiving first response information from the first access network device, the first response information being used to indicate whether the first access network device succeeded or failed in establishing the first session.

[0009] As an example, the first network element may be an AMF network element.

[0010] The fact that the mapped cell identifier currently corresponding to the cell of the first access network device includes at least one of the M mapped cell identifiers can be understood as follows: the current coverage area of ​​the first access network device includes the first geographical area, or the current coverage area of ​​the first access network device and the first geographical area intersect. In other words, all TAs currently supported by the first access network device intersect with the first geographical area or cover the first geographical area.

[0011] In this method, when the first access network device transmits MBS data to the UE, it can send the MBS data based on the mapped cell identifier. Compared to the prior art in which access network devices in an NTN network transmit MBS data based on the NTN cell, this method can avoid the problem of the first access network device being unable to accurately provide MBS services to the UE due to changes in the geographical area actually covered by the first access network device.

[0012] In addition, subsequently, when the mapped cell identifier currently corresponding to the cell of the first access network device no longer includes M mapped cell identifiers, but the mapped cell identifier currently corresponding to the cell of the second access network device includes at least one of the M mapped cell identifiers, or when the coverage area of ​​the first access network device no longer includes the first geographical area, and the coverage area of ​​the second access network device includes the first geographical area, the first network element can send an MBS session establishment request to the second access network device, and then the second access network device can establish a first session based on the MBS session establishment request. After the second access network device successfully establishes the first session, the second access network device can transmit MBS data through the first session and send MBS data to the terminal device located in the first geographical area. This avoids the problem of MBS data transmission interruption when the first access network device cannot continue to send MBS data to the terminal device located in the first geographical area due to changes in the geographical area actually covered by the first access network device.

[0013] In some possible implementations, the sending of an MBS session establishment request to a first access network device among the multiple access network devices based on the MBS service area information includes: sending MBS session establishment requests to the multiple access network devices respectively based on the MBS service area information; and receiving second response information from a second access network device, the second response information being used to indicate whether the second access network device succeeds or fails in establishing the first session, the second access network device being a device whose mapped cell identifier currently corresponding to a cell among the multiple access network devices does not include the M mapped cell identifiers.

[0014] In this method, both the first access network device and the second access network device can establish a first session. After the first access network device successfully establishes the first session, the first access network device can transmit MBS data through the first session and send the MBS data to terminal devices located in the first geographical area. Subsequently, when the coverage area of ​​the second access network device includes the first geographical area, the second access network device can directly transmit MBS data based on the established first session and send the MBS data to terminal devices located in the first geographical area. This avoids the problem of MBS data transmission interruption caused by changes in the geographical area actually covered by the first access network device, resulting in the first access network device being unable to continue sending MBS data to terminal devices located in the first geographical area.

[0015] In some possible implementations, when the second response information is used to indicate that the second access network device successfully establishes the first session, the method further includes: receiving first indication information from the second access network device, the first indication information including at least one of the following information: the second access network device does not send MBS data, the mapped cell identifier currently corresponding to the cell of the second access network device does not include the M mapped cell identifiers, and the second access network device does not establish an NG-U tunnel.

[0016] In this method, when the second access network device successfully establishes the first session, it is also necessary to send a first indication message to the first network element, so that the first network element can determine, based on the first indication message, that the second access network device successfully establishes the first session but does not transmit MBS data, thereby avoiding the situation where the first network element mistakenly believes that the MBS data transmission is successful when the first response message indicates that the first access network device fails to establish the first session and the first response message indicates that the second access network device successfully establishes the first session.

[0017] In some possible implementations, the method further includes: sending first information, where the first information is used to indicate whether establishment of the first session is successful or failed.

[0018] In the method, the first network element may send the first information to the second network element. As an example, the second network element may be an MB-SMF network element.

[0019] When the first response information is used to indicate that the first access network device failed to establish the first session, the second response information is used to indicate that the second access network device successfully established the first session, and the first network element receives the first indication information, the first network element can send the first information to the second network element, and the first information is used to indicate that the first session establishment failed.

[0020] Optionally, when the first response information is used to indicate that the first access network device failed to establish the first session, the second response information is used to indicate that the second access network device successfully established the first session, and the first network element receives the first indication information, the first network element may send the first information to the second network element, and the first information may also be used to indicate that the first session was successfully established. In addition, the first network element may also send second indication information to the second network element, where the second indication information is used to indicate that MBS data was not transmitted.

[0021] Optionally, when the first response information is used to indicate that the first access network device failed to establish the first session and the second response information is used to indicate that the second access network device failed to establish the first session, the first network element may send first information to the second network element, where the first information is used to indicate that the first session failed to be established.

[0022] Optionally, when the first response information is used to indicate that the first access network device has successfully established the first session, the first network element may send first information to the second network element, where the first information is used to indicate that the first session has been successfully established.

[0023] In a second aspect, the present application provides a communication method, which is applied to an access network device. The method includes: receiving an MBS session establishment request from a first network element, the MBS session establishment request being used to request establishment of a first session, the MBS session request including MBS service area information, the MBS service area information including M mapped cell identifiers, where M is a positive integer; establishing the first session according to the MBS session establishment request when a mapped cell identifier currently corresponding to a cell of the access network device includes at least one of the M mapped cell identifiers; and sending a first response message to the first network element, the first response message being used to indicate whether establishment of the first session by the access network device succeeded or failed.

[0024] In some possible implementations, the method further includes: when all possible mapped cell identifiers corresponding to the cell of the access network device include at least one of the M mapped cell identifiers and the mapped cell identifier currently corresponding to the cell of the access network device does not include the M mapped cell identifiers, establishing the first session according to the MBS session establishment request; and sending a second response message to the first network element, the second response message being used to indicate whether the access network device succeeds or fails in establishing the first session.

[0025] In some possible implementations, when the second response information is used to indicate that the access network device has successfully established the first session, the method further includes: sending a first indication information to the first network element, the first indication information including at least one of the following information: the access network device has not sent MBS data, the mapping cell identifier currently corresponding to the cell of the access network device does not include the M mapping cell identifiers, and the access network device has not established an NG-U tunnel.

[0026] It can be understood that the effects obtainable in the second aspect can be referred to the description in the first aspect and will not be elaborated here.

[0027] In a third aspect, the present application provides a communication method, which is applied to an access network device. The method includes: sending first MBS radio bearer information and second MBS radio bearer information of a first session to a first terminal device and / or a second terminal device in a first time period, where the first terminal device is located in a second geographical area, and the second terminal device is located in a third geographical area; wherein the first MBS radio bearer information corresponds to the second geographical area, and is used by the access network device to transmit first MBS data to the first terminal device; and the second MBS radio bearer information corresponds to the third geographical area, and is used by the access network device to transmit second MBS data to the second terminal device.

[0028] In this method, different geographic areas may correspond to different MBS radio bearer information, and different MBS radio bearer information transmits different MBS data. For any geographic area, a terminal device located in that geographic area can receive MBS data based on the MBS radio bearer information corresponding to that geographic area. This prevents the terminal device from receiving MBS data transmitted by MBS radio bearer information corresponding to other geographic areas, thereby avoiding the issue of access network equipment being unable to accurately transmit MBS data to the terminal device.

[0029] In some possible implementations, the method further includes: sending the first MBS radio bearer information or the second MBS radio bearer information to the first terminal device and / or the second terminal device in a second time period, where the second time period is before the first time period.

[0030] In this method, the first terminal device and / or the second terminal device can respectively determine the MBS wireless bearer information received by each of them in the second time period as the target MBS wireless bearer information, and then transmit the target MBS data based on the target MBS wireless bearer information, which is conducive to the first terminal device and / or the second terminal device receiving accurate MBS data.

[0031] As an example, assuming that the access network device can send the first MBS wireless bearer information to the first terminal device in the second time period, after the first terminal device receives the first MBS wireless bearer information and the second MBS wireless bearer information in the first time period, it can first determine that the MBS wireless bearer information received by the first terminal device in the second time period is the first MBS wireless bearer information, and then determine the first MBS wireless bearer information as the target wireless bearer information.

[0032] As another example, assuming that the access network device can send the second MBS radio bearer information to the second terminal device in the second time period, after the second terminal device receives the first MBS radio bearer information and the second MBS radio bearer information in the first time period, it can first determine that the MBS radio bearer information received by the second terminal device in the second time period is the second MBS radio bearer information, and then determine the second MBS radio bearer information as the target radio bearer information.

[0033] In some possible implementations, the method further includes: sending second indication information to the first terminal device and / or the second terminal device, wherein the second indication information is used to indicate a first correspondence between the first MBS radio bearer and the second geographical area and a second correspondence between the second MBS radio bearer and the third geographical area.

[0034] In this method, after the first terminal device and / or the second terminal device receives the second indication information, it can determine the target wireless bearer information based on the second indication information, and then receive the target MBS data based on the target MBS wireless bearer information, which is beneficial for the first terminal device and / or the second terminal device to receive accurate MBS data.

[0035] In a fourth aspect, the present application provides a communication method, which is applied to an access network device. The method includes: determining multiple beam-level cells based on multiple beams transmitted by the access network device, wherein the multiple beam-level cells correspond one-to-one to the multiple beams; and sending MBS data to a terminal device, wherein the terminal device is located in a target beam-level cell, wherein the target beam-level cell is any one of the multiple beam-level cells, and the MBS data is MBS data associated with the target beam-level cell.

[0036] In this method, the access network device can send MBS data based on beam-level cells, with different beam-level cells associated with different MBS data. When the coverage area of ​​a beam-level cell is smaller than that of the access network device cell, sending MBS data based on the beam-level cell can avoid the issue of the access network device being unable to accurately send MBS data to the terminal device due to the access network device cell having a larger coverage area.

[0037] In a fifth aspect, the present application provides a communication method, which is applied to a terminal device. The method includes: receiving first MBS radio bearer information and second MBS radio bearer information of a first session in a first time period, wherein the first MBS radio bearer information corresponds to a second geographical area, the first MBS radio bearer information is used by an access network device to transmit first MBS data to a terminal device located in the second geographical area, the second MBS radio bearer information corresponds to a third geographical area, the second MBS radio bearer information is used by the access network device to transmit second MBS data to a terminal device located in the third geographical area, and the terminal device is located in the second geographical area or the third geographical area; determining the first MBS radio bearer information or the second MBS radio bearer information as target MBS radio bearer information; and receiving target MBS data based on the target MBS radio bearer information, the target MBS data being the MBS data transmitted by the target MBS radio bearer information.

[0038] In some possible implementations, determining the first MBS radio bearer information or the second MBS radio bearer information as the target MBS radio bearer information includes: determining the MBS radio bearer information received by the terminal device in a second time period, the MBS radio bearer information received by the terminal device in the second time period is the first MBS radio bearer information or the second MBS radio bearer information, and the second time period is before the first time period; determining the MBS radio bearer information received by the terminal device in the second time period as the target MBS radio bearer information.

[0039] In some possible implementations, the method further includes: receiving second indication information, where the second indication information is used to indicate a first correspondence between the first MBS radio bearer and the second geographical area and a second correspondence between the second MBS radio bearer and the third geographical area.

[0040] Among them, the determining of the first MBS wireless bearer information or the second MBS wireless bearer information as the target MBS wireless bearer information includes: receiving area configuration information, the area configuration information is used to indicate the mapping cell identifier of each of a plurality of geographical areas, the plurality of geographical areas including the second geographical area and the third geographical area; obtaining location information, the location information is used to indicate the mapping cell identifier of the geographical area where the terminal device is located; determining the geographical area where the terminal device is located based on the area configuration information and the location information; and determining the MBS wireless bearer information corresponding to the geographical area where the terminal device is located as the target MBS wireless bearer information based on the second indication information.

[0041] It can be understood that the effects obtainable in the fifth aspect can be referred to the description in the second aspect and will not be elaborated here.

[0042] In a sixth aspect, the present application provides a communication method, which is applied to a second network element. The method includes: receiving multicast broadcast service (MBS) service area information, the MBS service area information including M mapped cell identifiers, where M is a positive integer; and sending the MBS service area information to a first network element.

[0043] In a possible implementation, the method further includes: receiving first information, where the first information is used to indicate whether the first session is established successfully or failed.

[0044] In a seventh aspect, the present application provides a communication method, applied in a third network element. The method comprises: sending third indication information to a fourth network element, the third indication information being used to indicate a first geographical area; receiving multicast broadcast service (MBS) service area information, the MBS service area information being generated by the fourth network element based on the third indication information, the MBS service area information comprising M mapped cell identifiers, the M mapped cell identifiers being the mapped cell identifiers corresponding to each access network device in the first geographical area among a plurality of access network devices, where M is a positive integer; and sending the MBS service area information to a second network element.

[0045] In an eighth aspect, the present application provides a communication method, applied to a fourth network element. The method comprises: receiving third indication information, the third indication information being used to indicate a first geographical area; generating multicast broadcast service (MBS) service area information based on the third indication information, the MBS service area information comprising M mapped cell identifiers, the M mapped cell identifiers being the mapped cell identifier corresponding to each access network device in the first geographical area among a plurality of access network devices, where M is a positive integer; and sending the MBS service area information to the third network element or the second network element.

[0046] In a ninth aspect, the present application provides a communication device comprising modules or units for implementing the method in any possible implementation of aspects 1 to 8. It should be understood that each module or unit can implement the corresponding function by executing a computer program.

[0047] In a tenth aspect, the present application provides a communication device comprising a processor, wherein the processor is configured to execute the communication method described in any possible implementation of the first to eighth aspects.

[0048] The apparatus may further include a memory for storing instructions and data. The memory is coupled to the processor, and when the processor executes the instructions stored in the memory, the methods described in the above aspects may be implemented. The apparatus may further include a communication interface for communicating between the apparatus and other devices. Exemplarily, the communication interface may be a transceiver, circuit, bus, module, or other type of communication interface.

[0049] In the eleventh aspect, the present application provides a communication system, which includes an access network device, a terminal device, a first network element, a second network element, a third network element and a fourth network element. The access network device can be used to execute the method in any possible implementation of the second to fourth aspects, the terminal device can be used to execute the method in the fifth aspect and any possible implementation of the fifth aspect, the first network element can be used to execute the method in the first aspect and any possible implementation of the first aspect, the second network element can be used to execute the method in the sixth aspect and any possible implementation of the sixth aspect, the third network element can be used to execute the method in the seventh aspect and any possible implementation of the seventh aspect, and the fourth network element can be used to execute the method in the eighth aspect and any possible implementation of the eighth aspect.

[0050] In a twelfth aspect, the present application provides a computer-readable storage medium storing a program code for execution by a communication device, wherein the program code includes instructions for implementing the methods in the first to eighth aspects.

[0051] In a thirteenth aspect, the present application provides a computer program product comprising instructions, which, when executed on a communication device, enables the communication device to implement the methods of the first to eighth aspects.

[0052] It can be understood that the effects obtainable in the sixth to thirteenth aspects can be referred to the description in the first or third aspect and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] FIG1 is a schematic diagram of a communication system applicable to an embodiment of the present application;

[0054] FIG2 is a schematic diagram of a multicast network architecture;

[0055] FIG3 is a schematic diagram of a control and transmission flow of a broadcast service;

[0056] FIG4 is a schematic diagram of an MBS system architecture applicable to the present application;

[0057] FIG5 is a schematic diagram of an existing MBS session establishment process;

[0058] FIG6 is a schematic diagram of an NTN network architecture applicable to the present application;

[0059] Figure 7 is a schematic diagram of the satellite coverage area at different time periods;

[0060] FIG8 is a schematic diagram of a satellite coverage area;

[0061] FIG9 is a flow chart of a communication method provided by one embodiment of the present application;

[0062] FIG10 is a flow chart of a communication method provided by another embodiment of the present application;

[0063] FIG11 is a flow chart of a communication method provided by another embodiment of the present application;

[0064] FIG12 is a schematic structural diagram of a communication device provided in one embodiment of the present application;

[0065] FIG13 is a schematic structural diagram of a communication device provided in another embodiment of the present application;

[0066] FIG14 is a schematic structural diagram of a communication device provided in yet another embodiment of the present application;

[0067] FIG15 is a schematic structural diagram of a communication device provided in yet another embodiment of the present application. DETAILED DESCRIPTION

[0068] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0069] To facilitate a clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. For example, the first information and the second information are merely used to distinguish different information and do not limit their order. Those skilled in the art will understand that words such as "first" and "second" do not limit the quantity or execution order, and words such as "first" and "second" do not necessarily limit differences.

[0070] In the embodiments of the present application, "at least one" refers to one or more, and "more" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c; a and b; a and c; b and c; or a, b, and c. Among them, a, b, and c can be single or multiple.

[0071] The technical solution of the present invention can be applied to various communication systems, such as long term evolution (LTE) systems, fifth generation (5G) communication systems or new radio (NR), non-terrestrial networks (NTN) and future communication systems such as sixth generation (6G) communication systems, etc., and the present invention is not limited to this.

[0072] Below, the embodiments of the present application are described in detail with reference to the accompanying drawings.

[0073] To facilitate understanding of the embodiments of the present application, a communication system applicable to the embodiments of the present application is first described with reference to Figure 1. As shown in Figure 1, the communication system includes a data server, a core network device, a wireless access network device, and a terminal.

[0074] The terminal can be connected to the wireless access network device wirelessly, the wireless access network device can be connected to the core network device wirelessly or by wire, and the core network device can be connected to the data server by wire. The core network device and the wireless access network device can be independent and different physical devices, or the functions of the core network device and the logical functions of the wireless access network device can be integrated into the same physical device, or a physical device can integrate some of the functions of the core network device and some of the functions of the wireless access network device. Terminals and wireless access network devices can be connected to each other by wire or wireless. Figure 1 is only a schematic diagram, and the communication system can also include other network devices, such as wireless relay devices and wireless backhaul devices, which are not shown in Figure 1.

[0075] Radio access network (RAN) equipment can be a device with wireless transceiver functions. The RAN equipment can be a device that provides wireless communication service and is usually located on the network side, including but not limited to: the next-generation base station (gNodeB, gNB) in 5G communication systems, the next-generation base station in the sixth generation (6G) mobile communication system, the base station in the future mobile communication system, or the access node in the WiFi system, etc., the evolved node B (eNB) in the long term evolution (LTE) system, the radio network controller (RNC), the node B (NB), the base station controller (BSC), the home base station (e.g., home evolved NodeB, or home Node B, HNB), the base band unit (BBU), the transmission reception point (TRP), the transmitting point (TP), the base transceiver station (BTS), etc. In a network structure, the access network device may include a centralized unit (CU) node, a distributed unit (DU) node, or a RAN device including a CU node and a DU node, or a control plane CU node and a user plane CU node, and a RAN device of a DU node. The access network device provides services for a cell, and a user equipment communicates with a base station through the transmission resources used by the cell (e.g., frequency domain resources, or spectrum resources). The cell may be a cell corresponding to a base station (e.g., a base station), and the cell may belong to a macro base station or a base station corresponding to a small cell. The small cells here may include: metro cells, micro cells, pico cells, femto cells, etc. These small cells have the characteristics of small coverage and low transmission power, and are suitable for providing high-speed data transmission services. Wireless access network equipment can be satellites, macro base stations, micro base stations or indoor stations, relay nodes or donor nodes, devices that provide wireless communication services to user devices, wireless controllers in cloud radio access network (CRAN) scenarios, relay stations, vehicle-mounted devices, wearable devices, and network equipment in future evolved networks.The access network device in this embodiment may also be an open radio access network (O-RAN) device, which may include an open distributed unit (O-DU) and an open centralized unit (O-CU).

[0076] The embodiments of the present application do not limit the specific technology and specific device form used by the wireless access network device. For ease of description, the following description uses a base station as an example of a wireless access network device.

[0077] The terminal can also be referred to as a terminal device, user equipment (UE), mobile station (MS), mobile terminal (MT), etc. It can be an entity on the user side for receiving or transmitting signals, such as a mobile phone. Terminal devices include handheld devices, vehicle-mounted devices, wearable devices, or computing devices with wireless communication functions. Exemplarily, the UE can be a mobile phone, a tablet computer, or a computer with wireless transceiver functions. The terminal device can also be a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in unmanned driving, a wireless terminal in telemedicine, a wireless terminal in a smart grid, a wireless terminal in a smart city, a wireless terminal in a smart home, and the like. The terminal 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 wearable, smart transportation, smart city, etc. The terminal can be a mobile phone, tablet computer, computer with wireless transceiver function, wearable device, vehicle, drone, helicopter, airplane, ship, robot, robotic arm, smart home device, etc. In the embodiment of the present application, the device for implementing the function of the terminal can be a terminal; it can also be a device that can support the terminal to implement the function, such as a chip system, or a communication module, or a modem, which can be installed in the terminal. In the embodiment of the present application, the chip system can be composed of a chip, or it can include a chip and other discrete devices. In the technical solutions provided in the embodiments of the present application, the device for implementing the function of the terminal is a terminal, and the terminal is a UE as an example to describe the technical solutions provided in the embodiments of the present application. The embodiments of the present application do not limit the specific technology and specific device form adopted by the terminal device.

[0078] In the system, the number of the wireless access network device may be at least one, and each of the at least one wireless access network device may be connected to at least one terminal.

[0079] Core network equipment is mainly used to provide user connections, user management and service carrying. It can serve as a bearer network to provide an interface to the external network to process and distribute services across the entire network.

[0080] The core network equipment may include multiple network elements, such as access and mobility management function (AMF) network element, session management function (SMF) network element, policy control function (PCF) network element, application function (AF) network element, user plane function (UPF) network element and network exposure function (NEF) network element.

[0081] Among them, the AMF network element is mainly responsible for mobility management in the mobile network, such as user location update, user registration network, user switching, etc.

[0082] The SMF network element is responsible for session management in mobile networks, such as session establishment, modification, and release. Specific functions include allocating IP addresses to users and selecting the UPF that provides packet forwarding capabilities.

[0083] The PCF network element mainly supports providing a unified policy framework to control network behavior, provides policy rules to the control layer network functions, and is responsible for obtaining user subscription information related to policy decisions.

[0084] The AF network element mainly supports interaction with the 3GPP core network to provide services, such as influencing data routing decisions, policy control functions, or providing some third-party services to the network side.

[0085] The UPF network element is primarily responsible for forwarding and receiving user data from terminal devices. It can receive user data from the data network and transmit it to the terminal device via the access network equipment. It can also receive user data from the terminal device via the access network equipment and forward it to the data network. The transmission resources and scheduling functions provided by the UPF network element to the terminal device are managed and controlled by the SMF network element.

[0086] NEF network elements are mainly used to support the opening of capabilities and events.

[0087] It is understandable that the system may also include unified data management (UDM) network elements and other network elements. The UDM network elements are used to generate authentication credentials, user identity processing (such as storing and managing user permanent identities, etc.), access authorization control and contract data management, etc.

[0088] In this application, the network element may also be referred to as an entity or a functional entity. For example, the AMF network element may also be referred to as an AMF entity or an AMF functional entity. For another example, the SMF network element may also be referred to as an SMF entity or an SMF functional entity.

[0089] It is understandable that the names of the network elements in this application do not limit the scope of this application and may also be other names.

[0090] The data server can send MBS data to the core network device. After receiving the MBS data, the core network device can send the MBS data to the base station. The base station can then send the MBS data to the UE. When the core network device sends MBS data to the base station, the MBS data can be transmitted through a common transmission channel, an MBS session. Each MBS session can include at least one MBS Quality of Service (QoS) flow. When the base station sends MBS data to the UE, the MBS data can be transmitted through an MBS radio bearer.

[0091] There are two transmission modes for an MBS radio bearer: the first mode may adopt a point-to-multipoint (PTM) transmission mode; the second mode may adopt a point-to-point (PTP) transmission mode.

[0092] MBS services include multicast and broadcast services. Multicast services are designed for services with high QoS requirements and require group management. They offer the same QoS level as unicast services. Broadcast services are designed for services with relatively low QoS requirements, similar to the single cell point-to-multipoint (SC-PTM) service in Long Term Evolution (LTE). They provide best-effort QoS guarantees.

[0093] In multicast services, core network equipment must manage UE joining and leaving. Transmission between core network equipment and base stations relies on MBS sessions. Base stations support both PTP and PTM transmission methods to send data to UEs, and can dynamically switch between PTP and PTM. Multicast services can only be provided to UEs in a radio resource control (RRC) connected state. Base stations and core network equipment must maintain UE information corresponding to the multicast service group. Core network equipment can also trigger MBS session deactivation / activation, without UEs being aware of the service status.

[0094] Figure 2 is a schematic diagram of a multicast network architecture. In this example, it is assumed that an MBS session may include Session 1 and Session 2. Session 1 is used to transmit first data to the base station. This first data may be MBS data required by Terminal 1. Accordingly, after receiving the first data, the base station may send the first data to Terminal 1.

[0095] Session 2 is used to transmit second data to the base station, where the second data is MBS data required by terminal 2. Accordingly, after receiving the second data, the base station may send the second data to terminal 1.

[0096] In addition, the core network device may also obtain the QoS flow and send the QoS flow to terminal 1 and terminal 2 through the base station.

[0097] Broadcast services support UEs in any RRC state. Core network equipment and base stations do not need to maintain a UE group for receiving broadcast services. When a service is being provided, the UE can autonomously receive it based on configuration information. Like multicast services, broadcast data transmission is designed only for the downlink (DL). However, unlike multicast services, broadcast services only support PTM transmission. UE-side broadcast service configuration and multicast service reception configuration are completely independent.

[0098] Broadcast services must be provided within a specific scope. Optionally, for the same service, different data contents can be provided within different scopes.

[0099] Figure 3 is a schematic diagram of a control and transmission process of a broadcast service. As shown in Figure 3, the dotted line represents the control process of the broadcast service, and the solid line represents the transmission process of the broadcast service.

[0100] An MBS service may be associated with an MBS service area. The MBS service area may include a group of tracking areas (TAs) and / or a group of cells, which are used to specify a specific range.

[0101] According to different MBS service areas, MBS services may include local MBS services and location dependent MBS services.

[0102] It should be noted that the term "MBS" in this application is broad and may include multicast, broadcast, or multicast. This means that the embodiments of this application can be applied to both multicast and broadcast service transmissions, as well as other services, without limitation. The term "MBS" in this application can be replaced with "multicast or broadcast."

[0103] For local multicast services, each MBS service is associated with an MBS service area. A UE can receive multicast data within the MBS service area. However, when the UE moves outside the MBS service area, even if it remains within the same base station, it cannot receive data from the local MBS service. In some embodiments, the local multicast service is also referred to as an area-limited MBS service.

[0104] For location-specific multicast services, a single MBS service can be associated with multiple MBS service areas, each of which corresponds to an area session ID. Different area session IDs for the same multicast service may correspond to different MBS service data content and data sources. The UE is unaware of the area session ID, only the MBS session ID. The base station controls the transmission of different multicast data to different UEs within different areas.

[0105] Figure 4 is a schematic diagram of an MBS system architecture applicable to this application. Compared to the existing 5G system architecture, this architecture adds four core network elements related to MBS services: the multicast / broadcast user plane function (MB-UPF), the multicast / broadcast session management function (MB-SMF), the multicast / broadcast service transport function (MBSTF), and the multicast / broadcast service function (MBSF).

[0106] The MB-UPF network element primarily implements user-plane forwarding for multicast / broadcast services. The MB-SMF network element primarily implements session management for multicast / broadcast services. The MBSTF network element primarily serves as an anchor for MBS data traffic, providing general packet transport functionality and supporting IP multicast applications such as framing, multi-streaming, and packet FEC (coding). The MBSF network element primarily supports MBS services, including selecting the BM-SMF, controlling the MBSTF, and determining transmission parameters.

[0107] Next, this application will use the broadcast service as an example to illustrate the process of establishing an MBS session. As shown in Figure 5, the session establishment process may include S501 to S510. It should be understood that this description is only an example and does not limit the process of establishing an MBS session.

[0108] S501: The MB-SMF network element allocates a temporary mobile group identity (TMGI), where the TMGI is used to identify a broadcast service.

[0109] In this method, the MB-SMF network element may allocate TMGI to all network elements related to the MBS service.

[0110] Optionally, this step may be triggered by an application function (AF) network element.

[0111] S502: The MB-SMF network element may obtain MBS service area information.

[0112] Optionally, the method for the MB-SMF network element to obtain MBS service area information may include: the AF network element sending location information to a network element function (NEF) network element; the NEF network element may determine the MBS service area information based on the location information and send the MBS service area information to the MB-SMF network element; and the MB-SMF network element receives the service area information accordingly.

[0113] In the method, the data server may receive indication information for instructing to send MBS data to UEs located in a limited geographical area. After receiving the indication information, the data server may send location information to the NEF network element based on the AF network element, where the location information is used to indicate the limited geographical area.

[0114] The MBS service area information is used to indicate an MBS service area. The MBS service area is generated based on location information. The MBS service area is associated with MBS data to be sent. The MBS service area may include at least one cell. The at least one cell may be all or part of the cells of a base station whose service area includes a defined geographical area.

[0115] S503, the MB-SMF network element determines the target access and mobility management function (AMF) network element based on the network repository function (NRF) network element, and the target AMF network element supports MBS services.

[0116] The NRF network element may include registration information, which is used to indicate whether each AMF network element in multiple AMF network elements supports MBS services.

[0117] In this method, the MB-SMF network element may send a request message to the NRF network element, where the request message is used to request an AMF network element that supports the MBS service. After receiving the request message, the NRF network element may determine the AMF network element that can support the MBS service based on the registration information, and send a response message to the MB-SMF network element, where the response message is used to indicate the AMF network element that can support the MBS service. After receiving the response message, the MB-SMF network element may determine the target AMF network element based on the response message.

[0118] S504: The MB-SMF network element sends an MBS session establishment request to the target AMF network element. The MBS session establishment request may include TMGI, quality of service configuration information, and MBS service area information. Accordingly, the target AMF network element receives the MBS session establishment request.

[0119] In this method, the quality of service configuration information is used to indicate the requirements of the MBS service, such as requirements in terms of latency.

[0120] S505: The target AMF network element sends an MBS session establishment request to the target base station. Correspondingly, the target base station may receive the MBS session establishment request.

[0121] In this method, the target base station includes all base stations supporting MBS services within the MBS service area.

[0122] The AMF network element may include configuration information, which is used to indicate whether each base station in multiple base stations supports MBS services.

[0123] Optionally, the target AMF network element sending an MBS session establishment request to the target base station may include: the target AMF network element may determine multiple base stations located in the MBS service area based on the MBS service area information, and then determine the target base station from these multiple base stations based on the configuration information, and send the MBS session establishment request to the target base station.

[0124] S506: The target base station establishes an MBS session context, and stores the TMGI and the quality of service configuration information in the MBS session establishment request in the MBS session context.

[0125] After the target base station establishes the MBS session context, if N3mb multicast transmission is used between the target base station and the MB-UPF and the target base station has an available multicast transmission tunnel address, the target base station joins the multicast group.

[0126] If N3mb unicast transmission is used between the target base station and the MB-UPF, or if there is no multicast transmission tunnel address in the target base station, the target base station allocates its N3mb tunnel endpoint to receive downlink MBS session data.

[0127] S507, the target base station sends a first session response message to the AMF network element, where the first session response message is used to indicate whether the MBS session is successfully established. Accordingly, the AMF network element receives the first session response message.

[0128] As an example, if the target base station successfully establishes an MBS session in at least one cell, the first session response information may be used to indicate that the MBS session establishment is successful. If the target base station fails to establish an MBS session in all cells, the first session response information may be used to indicate that the MBS session establishment fails.

[0129] Optionally, the first session response information may further include TMGI and N3mb tunnel information.

[0130] Optionally, assuming that there are multiple target base stations, each of these multiple target base stations can send a first session response message to the AMF network element, that is, the AMF network element can receive multiple first session response messages, and these multiple first session messages can correspond one-to-one to multiple target base stations.

[0131] S508: The AMF network element sends a second session response message to the MB-SMF network element, where the second session response message indicates whether the MBS session is successfully established. Correspondingly, the MB-SMF network element receives the second session response message.

[0132] If at least one of the multiple first session response messages indicates that the MBS session is successfully established, the second session response message is used to indicate that the MBS session is successfully established. If each of the multiple first session response messages indicates that the MBS session fails to be established, the second session response message is used to indicate that the MBS session fails to be established.

[0133] S509 , when the second session response information indicates that the MBS session is successfully established, the MB-SMF network element sends indication information to the AF network element, where the indication information is used to instruct the AF network element to send MBS data to the UE.

[0134] S510 : After receiving the instruction information, the AF network element sends MBS data to the UE located in the MBS service area based on the MB-UPF network element and the target base station.

[0135] In this method, a core network device may receive MBS data and an MBS service request from a data server, determine an MBS service area associated with the MBS data based on the MBS service request, and send an MBS session establishment request to an access network device whose coverage includes the MBS service area. The MBS session establishment request may include MBS service area information indicating the MBS service area associated with the MBS session. Accordingly, the access network device receives the MBS session request and establishes an MBS session based on the MBS session request. After the access network device successfully establishes the MBS session, the core network device sends the MBS data to the access network device. After receiving the MBS data, the access network device may send the MBS data to at least one cell. When multiple MBS service areas exist, cells in different MBS service areas send different MBS data.

[0136] Existing communication systems may involve NTN technology, and a communication network involving NTN technology may be referred to as an NTN network. The NTN network may include satellites or aircraft (eg, airplanes, drones, etc.). Hereinafter, this application will take the NTN network including satellites as an example for explanation.

[0137] In some scenarios, the satellite can be used as a base station or part of the functions of a base station to transmit data. Figure 6 is a schematic diagram of an NTN network architecture applicable to this application. As shown in Figure 6, the satellite has some or all of the functions of an access network device, and can be called a satellite base station. It can provide wireless access services and schedule wireless resources for UEs that access the network through the satellite base station. The satellite base station communicates with the UE through the Uu interface. Among them, the satellite base station and the core network equipment can communicate through the NG interface, and the satellite base station and the core network equipment can exchange NAS signaling and UE business data through the NG interface. The satellite radio interface (SRI) interface is a feeder link between the NTN gateway and the satellite. In Figure 6, the SRI interface can be used as part of the NG interface to realize communication interaction between the satellite and the core network equipment.

[0138] However, when the access network device in the NTN network uses the above method to send MBS data, the problem may arise that the access network device cannot accurately provide the MBS service to the UE.

[0139] Research has found that in the NTN network, some satellites are mobile relative to the ground, that is, the geographical area covered by the access network equipment corresponding to the satellite is constantly changing. As a result, the MBS data provided by the access network equipment to the UE is not the data required by the UE, or the access network equipment does not provide MBS data to the UE.

[0140] Taking any satellite as an example, assume that the area covered by the satellite during the first time period can be shown as shown in (a) of Figure 7. In this example, each small square can represent a geographical area, where square A can represent geographical area A, and square B can represent geographical area B. If the coverage area of ​​the satellite during the first time period includes square A, then the geographical area covered by satellite 1 during the first time period includes geographical area A.

[0141] Assume that the area covered by the satellite during the second time period can be as shown in (b) of Figure 7. In this example, each small square can represent a geographical area, where square A can represent geographical area A, and square B can represent geographical area B. If the coverage area of ​​the satellite during the second time period includes square B but does not include square A, then the geographical area covered by the satellite during the second time period includes geographical area B but does not include geographical area A.

[0142] In one scenario, the MBS data provided by the satellite to the UE located in geographic area B may also be data required by the UE located in geographic area A, resulting in the satellite being unable to accurately provide MBS data to the UE located in geographic area B.

[0143] In another scenario, the satellite provides MBS data required by a UE located in geographic area A during a first period, but no longer covers geographic area A during a second period. The satellite no longer provides MBS data to the UE located in geographic area A during the second period, which may result in the UE in geographic area A not being able to receive MBS data.

[0144] Furthermore, actual signals are transmitted by satellites based on satellite cells. Due to the significant distance between satellites and the ground, the coverage radius of satellite signals is significantly greater than that of current terrestrial networks. When satellites cover multiple geographic areas, the MBS data transmitted by the satellite to UEs in any one geographic area may include MBS data required by UEs in other geographic areas.

[0145] Assume that the satellite coverage is as shown in Figure 8. In this example, each small square may represent a geographic area, where square C may represent geographic area C and square D may represent geographic area D. Assume that the satellite coverage includes geographic area C and geographic area D. The satellite may transmit MBS data to UEs within the satellite coverage. The MBS data transmitted by the satellite includes MBS data required by UEs in geographic area C and MBS data required by UEs in geographic area D, where geographic area C and geographic area D belong to different MBS service areas of the same MBS session. In this example, the MBS data transmitted by the satellite to the UE in geographic area C also includes MBS data required by the UE in geographic area D, and the MBS data received by the satellite from the UE in geographic area D also includes MBS data required by the UE in geographic area C. Therefore, the satellite cannot accurately provide each UE with the MBS data required by each UE.

[0146] Currently, the coverage radius of air interface cells (also known as NTN cells) provided by NTN networks is too large. Air interface cell identifiers typically include a physical cell identifier (PCI) and a global cell identifier (CGI). The PCI is used for air interface physical cells, while the CGI is typically used in gNBs and CNs to uniquely identify a cell in the entire network. For core network equipment, the CGI is the most commonly used identifier for cells. In some scenarios, core network elements (such as NEF and AMF) can map specific geographic locations based on the CGI. However, the coverage radius of cells in NTN networks is too large. Furthermore, because some satellites in NTN networks are not geostationary but rather relatively mobile, the actual geographic coverage area of ​​these mobile cells can vary. If the unique CGI corresponding to a cell in existing technologies is still used to identify the corresponding cell, the core network no longer can accurately map it to detailed geographic location information, making it meaningless to continue to manage cell information based on the unique CGI. Therefore, the concept of mapped cell IDs has been introduced in NTN networks. An NTN cell can be associated with multiple mapped cell identifiers, each of which has its own corresponding actual geographic location. Access network devices and core network devices in the NTN network can interact through mapped cell identifiers, and can determine the geographic location corresponding to the mapped cell identifier based on the mapped cell identifier.

[0147] For example, the access network device may report the mapped cell identifier of the UE to the core network device, so that the core network can determine the actual geographical location of the UE based on the mapped cell identifier of the UE.

[0148] To this end, the present application provides a communication method and related apparatus for solving the problem in the prior art that access network equipment in an NTN network cannot accurately provide MBS services to UEs.

[0149] In the technical solution of this application, when an access network device in an NTN network transmits MBS data, it can first send the MBS data based on a mapped cell identifier. Compared to the prior art in which an access network device in an NTN network transmits MBS data based on an NTN cell, this solution can avoid the problem of the access network device being unable to accurately provide MBS services to the UE due to changes in the actual geographical area covered by the access network device or an overly large coverage area of ​​the access network device.

[0150] Next, this application will provide a detailed introduction to the technical solution of this application in conjunction with Figures 9 to 15.

[0151] Figure 9 is a flow chart of a communication method provided by an embodiment of the present application. As shown in Figure 9, the method may include S901 to S904.

[0152] S901. The first network element obtains MBS service area information, where the MBS service area information includes M mapped cell identifiers. The M mapped cell identifiers include a mapped cell identifier corresponding to each access network device in a first geographical area among multiple access network devices. The first geographical area is a geographical area associated with a first session, and M is a positive integer.

[0153] In this method, an example of the first network element may be an AMF network element in the system architecture shown in Figure 4. An example of an access network device may be a satellite or an aircraft.

[0154] In this method, different access network devices may correspond to different mapped cell identifiers in the first geographical area.

[0155] In the method, the first session may be used to transmit MBS data.

[0156] As an example, the mapped cell identifier corresponding to the access network device 1 in the first geographical area may be 11, and the mapped cell identifier corresponding to the access network device 2 in the first geographical area may be 21.

[0157] For any access network device, the access network device can be mobile relative to the opposite side, and the geographical area actually covered by the access network device is constantly changing, that is, the mapped cell identifier corresponding to the cell of the access network device at different times is also constantly changing.

[0158] For example, at a first moment, the mapped cell identifier corresponding to the cell of the access network device 1 may include 11, but at a second moment, the mapped cell identifier corresponding to the cell of the access network device 1 may not include 11.

[0159] Optionally, the first network element may obtain the MBS service area information from the second network element. For example, the MBS service area information may be carried in the MBS session establishment request. An example of the second network element may be the MB-SMF network element in the system architecture shown in FIG4 .

[0160] Optionally, the second network element may obtain the MBS service area information from a third network element or a fourth network element. An example of the third network element may be an AF network element in the system architecture shown in FIG4 , and an example of the fourth network element may be an NEF network element in the system architecture shown in FIG4 .

[0161] Taking the first network element, the second network element, the third network element, and the fourth network element as an example, the AMF network element, the MB-SMF network element, the AF network element, and the NEF network element, respectively, the AF network element can send the first geographical area to the NEF network element. After receiving the indication information, the NEF network element can generate MBS service area information based on the indication information. After generating the MBS service area information, the NEF network element can send the MBS service area information to the MB-SMF network element or the AF network element.

[0162] If the NEF network element sends the MBS service area information to the MB-SMF network element, the MB-SMF network element can send the MBS service area information to the AMF network element after receiving the MBS service area information.

[0163] If the NEF network element sends the MBS service area information to the AF network element, the AF network element can send the MBS service area information to the MB-SMF network element after receiving the MBS service area information. After receiving the MBS service area information, the MB-SMF network element can send the MBS service area information to the AMF network element.

[0164] S902: A first network element sends an MBS session establishment request to a first access network device among the multiple access network devices based on the MBS service area information. The MBS session establishment request is used to request establishment of a first session. The mapped cell identifier currently corresponding to the cell of the first access network device includes at least one of the M mapped cell identifiers. In response, the first access network device receives the MBS session establishment request.

[0165] In this method, the number of the first access network devices may be one or more.

[0166] In the present application, the fact that the mapped cell identifier currently corresponding to the cell of the first access network device includes at least one of the M mapped cell identifiers can be understood as follows: the current coverage area of ​​the first access network device includes the first geographical area, or the current coverage area of ​​the first access network device and the first geographical area intersect. In other words, all TAs currently supported by the first access network device intersect with the first geographical area or cover the first geographical area.

[0167] Optionally, the method in which the first network element sends an MBS session establishment request to a first access network device among multiple access network devices based on the MBS service area information may include: the first network element sends the MBS session establishment request to each of the multiple access network devices based on the MBS service area information. Accordingly, each of the multiple access network devices receives the MBS session establishment request.

[0168] The multiple access network devices include a first access network device and a second access network device, and the second access network device is a device whose mapped cell identifier currently corresponding to a cell in the multiple access network devices does not include the M mapped cell identifiers.

[0169] That is, all possible mapped cell identifiers corresponding to the cell of the second access network device include at least one of the M mapped cell identifiers, and the mapped cell identifier currently corresponding to the cell of the second access network device does not include the M mapped cell identifiers.

[0170] That all possible mapped cell identifiers corresponding to the cell of the second access network device include at least one of the M mapped cell identifiers can be understood as follows: the coverage area of ​​the second access network device may include the first geographical area, or the coverage area of ​​the second access network device and the first geographical area may intersect. In other words, all TAs currently supported by the second access network device may intersect with the first geographical area or cover the first geographical area.

[0171] If the mapped cell identifier currently corresponding to the cell of the second access network device does not include M mapped cell identifiers, it can be understood that: the current coverage area of ​​the second access network device does not include the first geographical area, or the coverage area of ​​the second access network device and the first geographical area do not intersect. In other words, all TAs currently supported by the second access network device do not intersect with the first geographical area or do not cover the first geographical area.

[0172] In other words, the coverage area of ​​the second access network device may include the first geographical area, but the current coverage area of ​​the second access network device does not include the first geographical area.

[0173] In this method, the number of the second access network device is also at least one.

[0174] In other words, the multiple access network devices are all access network devices that may / can cover the first geographical area, or are all access network devices that may / can have an intersection with the first geographical area. In other words, all TAs currently supported by the multiple access network devices may / can have an intersection with the first geographical area or will cover the first geographical area.

[0175] S903: The first access network device establishes a first session according to the MBS session establishment request.

[0176] In this method, the method for the first access network device to establish the first session according to the MBS session establishment request can refer to the existing technology and will not be described in detail here.

[0177] S904: The first access network device sends a first response message to the first network element, where the first response message indicates whether the first access network device succeeds or fails in establishing the first session. Correspondingly, the first network element receives the first response message.

[0178] In this method, the first access network device may include multiple cells, and the currently mapped cell identifier corresponding to at least one of the multiple cells may include at least one of the M mapped cell identifiers. In other words, the current coverage area of ​​at least one of the multiple cells includes the first geographical area.

[0179] When the first session is successfully established in a cell among the at least one cell, the first access network device sends first response information to the first network element, where the first response information is used to indicate that the first session is successfully established by the first access network device.

[0180] When no cell in the at least one cell successfully establishes the first session, the first access network device sends first response information to the first network element, where the first response information is used to indicate that the first access network device fails to establish the first session.

[0181] Optionally, when at least one of all TAs currently supported by the first access network device intersects with the first geographical area, but the current cell of the first access network device does not cover the first geographical area, the first access network device may further send first indication information to the first network element, where the first indication information includes at least one of the following information: the first access network device does not send MBS data, the mapped cell identifier currently corresponding to the cell of the first access network device does not include M mapped cell identifiers, and the first access network device does not establish an NG-U tunnel. Accordingly, the first network element receives the first indication information.

[0182] In this method, when the first access network device transmits MBS data to the UE, the MBS data can be sent based on the mapped cell identifier. Compared to the prior art in which an access network device in an NTN network transmits MBS data based on the NTN cell, this method can avoid the problem of the first access network device being unable to accurately provide MBS services to the UE due to changes in the geographical area actually covered by the first access network device.

[0183] In addition, when the mapped cell identifier currently corresponding to the cell of the first access network device no longer contains M mapped cell identifiers, but the mapped cell identifier currently corresponding to the cell of the second access network device contains at least one of the M mapped cell identifiers, the first network element can send an MBS session establishment request to the second access network device, and then the second access network device can establish a first session based on the MBS session establishment request. After the second access network device successfully establishes the first session, the second access network device can transmit MBS data through the first session and send MBS data to the terminal device located in the first geographical area. This avoids the problem of MBS data transmission interruption when the first access network device cannot continue to send MBS data to the terminal device located in the first geographical area due to changes in the geographical area actually covered by the first access network device.

[0184] Optionally, when the first network element sends an MBS session establishment request to each of the multiple access network devices based on the MBS service area information, the communication method may further include S905 to S907.

[0185] S905: The second access network device establishes a first session according to the MBS session establishment request.

[0186] In this method, the method for the second access network device to establish the first session according to the MBS session establishment request can refer to the existing technology and will not be described in detail here.

[0187] S906: The second access network device sends a second response message to the first network element, where the second response message indicates whether the second access network device succeeds or fails in establishing the first session. Correspondingly, the first network element receives the second response message.

[0188] The manner in which the second access network device sends the second response information may refer to the manner in which the first access network device sends the first response information in S904, and will not be repeated here.

[0189] Optionally, when the second response information is used to indicate that the second access network device successfully established the first session, the method may further include: the second access network device sending first indication information to the first network element, the first indication information including at least one of the following information: the second access network device did not send MBS data, the mapped cell identifier currently corresponding to the cell of the second access network device does not include M mapped cell identifiers, and the second access network device did not establish an NG-U tunnel. Accordingly, the first network element receives the first indication information.

[0190] S907: The first network element sends first information to the second network element, where the first information is used to indicate success or failure in establishing the first session.

[0191] In this method, when the first response information is used to indicate that the first access network device failed to establish the first session, the second response information is used to indicate that the second access network device successfully established the first session, and the first network element receives the first indication information, the first network element can send the first information to the second network element, and the first information is used to indicate that the first session failed to be established.

[0192] Optionally, when the first response information is used to indicate that the first access network device failed to establish the first session, the second response information is used to indicate that the second access network device successfully established the first session, and the first network element receives the first indication information, the first network element may send the first information to the second network element, and the first information may also be used to indicate that the first session was successfully established. In addition, the first network element may also send second indication information to the second network element, where the second indication information is used to indicate that MBS data was not transmitted.

[0193] Optionally, when the first response information is used to indicate that the first access network device failed to establish the first session and the second response information is used to indicate that the second access network device failed to establish the first session, the first network element may send first information to the second network element, where the first information is used to indicate that the first session failed to be established.

[0194] Optionally, when the first response information is used to indicate that the first access network device has successfully established the first session, the first network element may send first information to the second network element, where the first information is used to indicate that the first session has been successfully established.

[0195] Optionally, when the first access network device is not included in the multiple access network devices, if the second response information is used to indicate that the second access network device successfully established the first session and the first network element receives the first indication information, the first network element may send first information to the second network element, where the first information is used to indicate that the first session was successfully established. Optionally, the first network element may also send indication information to the second network element, where the indication information is used to indicate that the second access network device successfully established the first session.

[0196] Optionally, the first network element may further store an identifier of the access network device that sent the first indication information.

[0197] Optionally, when the second access network device is not included in the multiple access network devices, if the first response information is used to indicate that the first access network device has successfully established the first session, and there is at least one TA among all TAs currently supported by the first access network device that has an intersection with the first geographical area, but the current cell of the first access network device does not cover the first geographical area, the first access network device may also send first indication information to the first network element, where the first indication information includes at least one of the following information: the first access network device has not sent MBS data, the mapped cell identifier currently corresponding to the cell of the first access network device does not include M mapped cell identifiers, and the first access network device has not established an NG-U tunnel. Accordingly, the first network element receives the first indication information.

[0198] In this method, both the first access network device and the second access network device can establish a first session. After the first access network device successfully establishes the first session, the first access network device can transmit MBS data through the first session and send the MBS data to terminal devices located in the first geographical area. Subsequently, when the coverage area of ​​the second access network device includes the first geographical area, the second access network device can directly transmit MBS data based on the established first session and send the MBS data to terminal devices located in the first geographical area. This avoids the problem of MBS data transmission interruption caused by changes in the geographical area actually covered by the first access network device, resulting in the first access network device being unable to continue sending MBS data to terminal devices located in the first geographical area.

[0199] Optionally, when the second access network device successfully establishes the first session but does not transmit MBS data, if the subsequent coverage area of ​​the second access network device includes the first geographical area, the second access network device may also trigger session modification, session release, etc., to notify the first network element that the second access network device failed to send the MBS service or did not send the MBS data.

[0200] Figure 10 is a flow chart of a communication method provided by another embodiment of the present application. As shown in Figure 10, the communication method may include S1001 to S1003.

[0201] S1001: An access network device sends first MBS radio bearer information and second MBS radio bearer information of a first session to a first terminal device and / or a second terminal device in a first time period. The first terminal device is located in a second geographical area, and the second terminal device is located in a third geographical area. Accordingly, the first terminal device and / or the second terminal device receives the first MBS radio bearer information and the second MBS radio bearer information of the first session.

[0202] In the method, the cell coverage area of ​​the access network device includes the second geographical area and the third geographical area. The access network device can send the first MBS radio bearer information and the second MBS radio bearer information to terminal devices located in all coverage areas of the cell of the access network device.

[0203] In this method, the first MBS radio bearer information corresponds to the second geographical area and is used by the access network device to transmit the first MBS data to the first terminal device. The second MBS radio bearer information corresponds to the third geographical area and is used by the access network device to transmit the second MBS data to the second terminal device.

[0204] S1002: The first terminal device and / or the second terminal device determines the first MBS radio bearer information or the second MBS radio bearer information as target MBS radio bearer information.

[0205] In one possible implementation, the access network device may send the first MBS radio bearer information or the second MBS radio bearer information to the first terminal device and / or the second terminal device in the second time period, and the first terminal device and / or the second terminal device may respectively determine the MBS radio bearer information received in the second time period as the target MBS radio bearer information, and the second time period is located before the first time period.

[0206] As an example, assuming that the access network device can send the first MBS wireless bearer information to the first terminal device in the second time period, after the first terminal device receives the first MBS wireless bearer information and the second MBS wireless bearer information in the first time period, it can first determine that the MBS wireless bearer information received by the first terminal device in the second time period is the first MBS wireless bearer information, and then determine the first MBS wireless bearer information as the target wireless bearer information.

[0207] As another example, assuming that the access network device can send the second MBS radio bearer information to the second terminal device in the second time period, after the second terminal device receives the first MBS radio bearer information and the second MBS radio bearer information in the first time period, it can first determine that the MBS radio bearer information received by the second terminal device in the second time period is the second MBS radio bearer information, and then determine the second MBS radio bearer information as the target radio bearer information.

[0208] In this method, the access network device may send the first MBS radio bearer information or the second MBS radio bearer information to the terminal device in the second time period, and may send the first MBS radio bearer information and the second MBS radio bearer information to the terminal device in the first time period. Although the MBS radio bearer information sent in the first and second time periods has changed, the access network device does not need to indicate the MBS radio bearer information change to the terminal device. This saves the terminal device the overhead of re-reading the MBS radio bearer information.

[0209] Optionally, the access network device may further send the first MBS radio bearer information or the second MBS radio bearer information to the first terminal device and / or the second terminal device in a third time period, where the third time period is after the first time period.

[0210] As an example, assuming that the access network device sends the first MBS radio bearer information to the first terminal device in the second time period, the access network device may also send the first MBS radio bearer information to the first terminal device in the third time period.

[0211] Optionally, the access network device that sends the first MBS radio bearer information to the first terminal device in the second time period and the access network device that sends the first MBS radio bearer information to the first terminal device in the third time period may be different access network devices.

[0212] As another example, assuming that the access network device sends the second MBS radio bearer information to the second terminal device in the second time period, the access network device may also send the second MBS radio bearer information to the second terminal device in the third time period.

[0213] Optionally, the access network device that sends the second MBS radio bearer information to the second terminal device in the second time period and the access network device that sends the second MBS radio bearer information to the second terminal device in the third time period may be different access network devices.

[0214] In this method, the access network device may send the first MBS radio bearer information and the second MBS radio bearer information to the terminal device in the first time period, and may send the first MBS radio bearer information or the second MBS radio bearer information to the terminal device in the third time period. Although the MBS radio bearer information sent by the access network device in the first and third time periods has changed, the access network device does not need to indicate the MBS radio bearer information change to the terminal device. This saves the terminal device the overhead of re-reading the MBS radio bearer information.

[0215] In another possible implementation, the access network device may send second indication information to the first terminal device and / or the second terminal device, where the second indication information is used to indicate a first correspondence between the first MBS radio bearer and the second geographical area, and a second correspondence between the second MBS radio bearer and the third geographical area. Accordingly, after receiving the second indication information, the first terminal device and / or the second terminal device may determine target radio bearer information based on the second indication information.

[0216] Optionally, the method for a terminal device to determine target wireless bearer information based on second indication information may include: receiving area configuration information, the area configuration information being used to indicate a mapping cell identifier for each of a plurality of geographical areas, the plurality of geographical areas including a second geographical area and a third geographical area; obtaining location information, the location information being used to indicate a mapping cell identifier for the geographical area where the terminal device is located; determining the geographical area where the terminal device is located based on the area configuration information and the location information; and determining the MBS wireless bearer information corresponding to the geographical area where the terminal device is located as the target MBS wireless bearer information based on the second indication information.

[0217] Optionally, the NEF network element may generate and send area configuration information to the AF network element. After receiving the area configuration information, the AF network element may send the area configuration information to each terminal device. Accordingly, each terminal device may receive the area configuration information.

[0218] As an example, assuming that the first terminal device determines that the mapping cell identifier of the geographical area where the first terminal device is located is the mapping cell identifier of the second geographical area based on the location information and area configuration information, the first terminal device can determine that it is located in the second geographical area, and then determine that the wireless bearer information corresponding to the second geographical area is the first wireless bearer information based on the second indication information, and then determine the first wireless bearer information as the target wireless bearer information.

[0219] As another example, assuming that the second terminal device determines that the mapping cell identifier of the geographical area where the second terminal device is located is the mapping cell identifier of the third geographical area based on the location information and the area configuration information, the second terminal device can determine that it is located in the third geographical area, and then determine that the wireless bearer information corresponding to the third geographical area is the second wireless bearer information based on the second indication information, and then determine the second wireless bearer information as the target wireless bearer information.

[0220] Optionally, when the AF network element sends the area configuration information to each terminal device, it may be sent in a standalone (SA) manner.

[0221] Optionally, when the terminal device receives the area configuration information, it can be received through an application layer message or a service announcement notification.

[0222] S1003, the first terminal device and / or the second terminal device receives target MBS data based on the target MBS radio bearer information, where the target MBS data is MBS data transmitted by the target MBS radio bearer information.

[0223] As an example, assuming that the target radio bearer information is the first radio bearer information, the target MBS data may be the first MBS data.

[0224] As another example, assuming that the target radio bearer information is the second radio bearer information, the target MBS data may be the second MBS data.

[0225] In this method, different geographic areas may correspond to different MBS radio bearer information, and different MBS radio bearer information transmits different MBS data. For any geographic area, terminal devices located in that geographic area can transmit MBS data based on the MBS radio bearer information corresponding to that geographic area. This prevents the terminal device from receiving MBS data transmitted by MBS radio bearer information corresponding to other geographic areas, thereby avoiding the issue of access network equipment being unable to accurately transmit MBS data to the terminal device.

[0226] Figure 11 is a flow chart of a communication method provided by another embodiment of the present application. As shown in Figure 11, the communication method may include S1101 to S1102.

[0227] S1101: The access network device determines a plurality of beam-level cells based on a plurality of beams transmitted by itself, where the plurality of beam-level cells correspond one-to-one to the plurality of beams.

[0228] As an example, assuming that the access network device can transmit four beams in a cell, the access network device can generate four beam-level cells based on the four beams.

[0229] Optionally, different beam-level cells correspond to different PCIs.

[0230] Optionally, different beam-level cells may send system messages independently, or different beam-level cells may send different system messages.

[0231] Optionally, different beam-level cells may send MCCH messages independently, or different beam-level cells may send different MCCH messages.

[0232] S1102, the access network device sends MBS data to the terminal device, the terminal device is located in a target beam-level cell, the target beam-level cell is any one of multiple beam-level cells, and the MBS data is MBS data associated with the target beam-level cell.

[0233] In this method, the access network device can send MBS data based on beam-level cells, and different beam-level cells are associated with different MBS data. When the coverage area of ​​a beam-level cell is smaller than that of the access network device cell, sending MBS data based on the beam-level cell can avoid the problem of the access network device being unable to accurately send MBS data to the terminal device due to the access network device cell having a larger coverage area.

[0234] FIG12 is a schematic diagram of the structure of a communication device provided in an embodiment of the present application. As shown in FIG12 , the communication device 1200 may include an acquisition module 1201 , a sending module 1202 , and a receiving module 1203 .

[0235] As an example, the communication device 1200 may be used to implement the communication method of the embodiment shown in Figure 9. The acquiring module 1201 may be used to execute S901, the sending module 1202 may be used to execute S902, and the receiving module 1203 may be used to execute S903.

[0236] Optionally, the receiving module 1203 may also be used to execute S906 , and the sending module 1202 may be used to execute S907 .

[0237] The communication device 1200 can be applied in a first network element.

[0238] FIG13 is a schematic diagram of the structure of a communication device provided in another embodiment of the present application. As shown in FIG13 , the communication device 1300 may include a receiving module 1301 , a processing module 1302 , and a sending module 1303 .

[0239] As a first example, the communication device 1300 may be used to implement the communication method of the embodiment shown in FIG. 9 .

[0240] Optionally, the communication apparatus 1300 may be applied to a first access network device, wherein the receiving module 1301 may be used to execute S902, the processing module 1302 may be used to execute S903, and the sending module 1303 may be used to execute S904.

[0241] Optionally, the communication apparatus 1300 may be applied to a second access network device, wherein the receiving module 1301 may be used to execute S902, the processing module 1302 may be used to execute S905, and the sending module 1303 may be used to execute S906.

[0242] As a second example, the communication apparatus 1300 may be used to implement the communication method of the embodiment shown in Figure 10. The sending module 1303 may be used to execute S1001. The communication apparatus 1300 may be applied to an access network device.

[0243] As a third example, the communication apparatus 1300 may be used to implement the communication method of the embodiment shown in Figure 11. The processing module 1302 may be used to execute S1101, and the sending module 1303 may be used to execute S1102. The communication apparatus 1300 may be applied to an access network device.

[0244] FIG14 is a schematic diagram of the structure of a communication device provided in yet another embodiment of the present application. As shown in FIG14 , the communication device 1400 may include a receiving module 1401 and a processing module 1402 .

[0245] As an example, the communication device 1400 may be used to implement the communication method of the embodiment shown in Figure 10. The receiving module 1401 may be used to execute S1001 and S1003, and the processing module 1402 may be used to execute S1002.

[0246] Optionally, the communication apparatus 1400 may be applied to a first terminal device or a second terminal device.

[0247] As another example, the communication device 1400 may be used to implement the communication method of the embodiment shown in Figure 11. The receiving module 1401 may be used to execute S1102.

[0248] Optionally, the communication apparatus 1400 may be applied to a terminal device.

[0249] Figure 15 is a schematic diagram of the structure of a communication device provided in another embodiment of the present application. As shown in Figure 15, the communication device 1500 includes a processor 1501 and an interface circuit 1502. The processor 1501 and the interface circuit 1502 are coupled to each other. It is understood that the interface circuit 1502 can be a transceiver or an input / output interface. Optionally, the communication device 1500 may also include a memory 1503 for storing instructions executed by the processor 1501, or storing input data required by the processor 1501 to execute instructions, or storing data generated after the processor 1501 executes instructions.

[0250] As a first example, the interface circuit 1502 is used to implement the functions of the above-mentioned acquisition module 1201, sending module 1202 and receiving module 1203.

[0251] As a second example, the processor 1501 may be used to implement the functions of the processing module 1302 , and the interface circuit 1502 may be used to implement the functions of the receiving module 1301 and the sending module 1303 .

[0252] As a third example, the processor 1501 may be used to implement the functions of the processing module 1402 , and the interface circuit 1502 may be used to implement the functions of the receiving module 1401 .

[0253] The communication apparatus 1500 may be a communication device or a chip used in a communication device.

[0254] 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 a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable programmable read-only memory, a register, a hard disk, a mobile hard disk, a CD-ROM or any other form of storage medium well 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 network device or a terminal device. Of course, the processor and the storage medium can also be present in a network device or a terminal device as discrete components.

[0255] In the above embodiments, all or part of the embodiments may be implemented using software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are performed in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device, or other programmable device. The computer program or instructions may be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions may be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium may 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, hard disk, or magnetic tape; an optical medium, such as a digital video disk; or a semiconductor medium, such as a solid-state drive.

[0256] 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.

[0257] 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: The method is applied in a first network element, and the method includes: Acquire multicast broadcast service MBS service area information, where the MBS service area information includes M mapped cell identifiers, where the M mapped cell identifiers include a mapped cell identifier corresponding to each access network device in a first geographical area among multiple access network devices, where the first geographical area is a geographical area associated with the first session, and M is a positive integer; Sending an MBS session establishment request to a first access network device among the multiple access network devices based on the MBS service area information, where the MBS session establishment request is used to request establishment of the first session, and a mapped cell identifier currently corresponding to a cell of the first access network device includes at least one of the M mapped cell identifiers; Receive first response information from the first access network device, where the first response information is used to indicate whether the first access network device succeeds or fails in establishing the first session.

2. The method according to claim 1, characterized in that The sending an MBS session establishment request to a first access network device among the multiple access network devices based on the MBS service area information includes: Sending MBS session establishment requests to the multiple access network devices respectively based on the MBS service area information; Receive a second response message from a second access network device, where the second response message is used to indicate whether the second access network device succeeds or fails in establishing a first session, and the second access network device is a device whose mapped cell identifier currently corresponding to a cell among the multiple access network devices does not include the M mapped cell identifiers.

3. The method according to claim 2, characterized in that When the second response information is used to indicate that the second access network device successfully establishes the first session, the method further includes: Receive first indication information from the second access network device, the first indication information including at least one of the following information: the second access network device does not send MBS data, the mapped cell identifier currently corresponding to the cell of the second access network device does not include the M mapped cell identifiers, and the second access network device does not establish an NG-U tunnel.

4. The method according to any one of claims 1 to 3, characterized in that The method further comprises: Sending first information, where the first information is used to indicate whether the first session is established successfully or failed.

5. A communication method, characterized in that: The method is applied to an access network device, and the method comprises: receiving an MBS session establishment request from a first network element, the MBS session establishment request being used to request establishment of a first session, the MBS session request including MBS service area information, the MBS service area information including M mapped cell identifiers, where M is a positive integer; When the mapped cell identifier currently corresponding to the cell of the access network device includes at least one of the M mapped cell identifiers, establishing the first session according to the MBS session establishment request; Sending first response information to the first network element, where the first response information is used to indicate whether the access network device succeeds or fails in establishing the first session.

6. The method according to claim 5, characterized in that The method further comprises: When all possible mapped cell identifiers corresponding to the cell of the access network device include at least one of the M mapped cell identifiers and the mapped cell identifier currently corresponding to the cell of the access network device does not include the M mapped cell identifiers, establishing the first session according to the MBS session establishment request; Sending second response information to the first network element, where the second response information is used to indicate whether the access network device succeeds or fails in establishing the first session.

7. The method according to claim 6, characterized in that When the second response information is used to indicate that the access network device successfully establishes the first session, the method further includes: Sending first indication information to the first network element, the first indication information including at least one of the following information: the access network device does not send MBS data, the mapped cell identifier currently corresponding to the cell of the access network device does not include the M mapped cell identifiers, and the access network device does not establish an NG-U tunnel.

8. A communication method, characterized in that: The method is applied to an access network device, and the method comprises: Sending first MBS radio bearer information and second MBS radio bearer information of a first session to a first terminal device and / or a second terminal device in a first time period, wherein the first terminal device is located in a second geographical area and the second terminal device is located in a third geographical area; The first MBS wireless bearer information corresponds to the second geographical area, and is used by the access network device to transmit the first MBS data to the first terminal device; the second MBS wireless bearer information corresponds to the third geographical area, and is used by the access network device to transmit the second MBS data to the second terminal device.

9. The method according to claim 8, characterized in that The method further comprises: Sending the first MBS radio bearer information or the second MBS radio bearer information to the first terminal device and / or the second terminal device in a second time period MBS radio bearer information, the second time period is located before the first time period.

10. The method according to claim 8, characterized in that The method further comprises: Sending second indication information to the first terminal device and / or the second terminal device, where the second indication information is used to indicate a first corresponding relationship between the first MBS radio bearer and the second geographical area and a second corresponding relationship between the second MBS radio bearer and the third geographical area.

11. A communication method, characterized in that: The method is applied to an access network device, and the method comprises: Determine a plurality of beam-level cells based on a plurality of beams transmitted by the access network device, wherein the plurality of beam-level cells correspond one-to-one to the plurality of beams; MBS data is sent to a terminal device, where the terminal device is located in a target beam-level cell, where the target beam-level cell is any one of the multiple beam-level cells, and the MBS data is MBS data associated with the target beam-level cell.

12. A communication method, characterized in that: The method is applied in a terminal device, and the method includes: receiving first MBS radio bearer information and second MBS radio bearer information of a first session in a first time period, wherein the first MBS radio bearer information corresponds to a second geographical area, the first MBS radio bearer information is used by an access network device to transmit first MBS data to a terminal device located in the second geographical area, the second MBS radio bearer information corresponds to a third geographical area, the second MBS radio bearer information is used by the access network device to transmit second MBS data to a terminal device located in the third geographical area, and the terminal device is located in the second geographical area or the third geographical area; Determine the first MBS radio bearer information or the second MBS radio bearer information as target MBS radio bearer information; Target MBS data is received based on the target MBS radio bearer information, where the target MBS data is MBS data transmitted by the target MBS radio bearer information.

13. The method according to claim 12, characterized in that The determining the first MBS radio bearer information or the second MBS radio bearer information as the target MBS radio bearer information includes: Determine MBS radio bearer information received by the terminal device in a second time period, the MBS radio bearer information received by the terminal device in the second time period is the first MBS radio bearer information or the second MBS radio bearer information, and the second time period is before the first time period; The MBS radio bearer information received by the terminal device in the second time period is determined as the target MBS radio bearer information.

14. The method according to claim 12, characterized in that The method further comprises: receiving second indication information, where the second indication information is used to indicate a first correspondence between the first MBS radio bearer and the second geographical area and a second correspondence between the second MBS radio bearer and the third geographical area; The determining the first MBS radio bearer information or the second MBS radio bearer information as the target MBS radio bearer information includes: receiving area configuration information, where the area configuration information is used to indicate a mapped cell identifier for each of a plurality of geographical areas, where the plurality of geographical areas include the second geographical area and the third geographical area; Acquire location information, where the location information is used to indicate a mapped cell identifier of a geographical area where the terminal device is located; Determine the geographical area where the terminal device is located based on the area configuration information and the location information; Based on the second indication information, the MBS radio bearer information corresponding to the geographical area where the terminal device is located is determined as the target MBS radio bearer information.

15. A communication method, characterized in that: The method is applied in a second network element, and the method includes: receiving multicast broadcast service MBS service area information, wherein the MBS service area information includes M mapped cell identifiers, where M is a positive integer; The MBS service area information is sent to the first network element.

16. The method according to claim 15, characterized in that The method further comprises: First information is received, where the first information is used to indicate whether the first session is established successfully or failed.

17. A communication method, characterized in that: The method is applied in a third network element, and the method includes: Sending third indication information to a fourth network element, where the third indication information is used to indicate the first geographical area; receiving multicast broadcast service MBS service area information, where the MBS service area information is generated by the fourth network element based on the third indication information, and the MBS service area information includes M mapping cell identifiers, where the M mapping cell identifiers are mapping cell identifiers corresponding to each access network device in the first geographical area among multiple access network devices, and M is a positive integer; The MBS service area information is sent to the second network element.

18. A communication method, characterized in that: The method is applied in a fourth network element, and the method includes: receiving third indication information, where the third indication information is used to indicate the first geographical area; Generate multicast broadcast service MBS service area information based on the third indication information, the MBS service area information including M mapping cell identifiers, the M mapping cell identifiers are mapping cell identifiers corresponding to each access network device in the first geographical area among the multiple access network devices, and M is a positive integer; The MBS service area information is sent to the third network element or the second network element.

19. A communication device, characterized in that: The method comprises a functional module for implementing the method according to any one of claims 1 to 18.

20. A communication device, characterized in that: include: Memory and processor; The memory is used to store program instructions; The processor is configured to execute program instructions in the memory to implement the method according to any one of claims 1 to 18.

21. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a program code for computer execution, wherein the program code includes instructions for implementing the method according to any one of claims 1 to 18.

22. A computer program product, characterized in that The computer program product comprises instructions for implementing the method according to any one of claims 1 to 18.

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