Communication method and related apparatus

Abstract

Embodiments of the present application provide a communication method and a related apparatus. In the method, on the basis of an intended service area reported by a terminal device, a network side can manage / control a session related to an MBS, such that a terminal device, which is in an intended area associated with the MBS, can use the MBS, whereas a terminal device, which has left the intended area associated with the MBS, cannot use the MBS. Thus, the MBS can be accurately managed, improving application feasibility of the MBS in NTN communications.

Description

A communication method and related apparatus

[0001] This application claims priority to Chinese Patent Application No. 202510390319.8, filed on March 28, 2025, entitled "A Communication Method and Related Apparatus", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of wireless communication, and more particularly to a communication method and related apparatus. Background Technology

[0003] Multicast and broadcast service (MBS) is a service that targets multiple user equipment (UEs), such as live broadcasting, public safety services, and batch software update services. Non-terrestrial network (NTN) communication (e.g., satellite communication) has advantages over terrestrial network (TN) communication (e.g., terrestrial cellular network communication) in terms of longer communication distance and larger coverage area. Considering that NTN communication has a larger coverage area compared to terrestrial network communication, multicast and broadcast service can provide better service; therefore, multicast and broadcast service from terrestrial network communication can be applied to NTN communication. Since the intended service area (ISA) of MBS service is usually smaller than the coverage area of ​​an NTN cell, how to use MBS service in NTN communication is a problem that needs to be considered. Summary of the Invention

[0004] This application provides a communication method and related apparatus. This method can provide an effective way to manage / use MBS services in NTN communication, enriching the communication methods in NTN scenarios.

[0005] In a first aspect, embodiments of this application provide a communication method applied to a network device in non-terrestrial network (NTN) communication. This method can be executed by components (such as circuits, chips, or chip systems) configured in the network device, or by logic modules or software capable of implementing or partially implementing the functions of the network device. This application does not limit the scope of this method; the following description uses a network device as an example.

[0006] The method includes: receiving a first message, wherein the first message is used to indicate MBS services of a terminal device, and the first message is also used to indicate the intended service area of ​​the terminal device.

[0007] For example, MBS services include MBS broadcast services and MBS multicast services transmitted via a multicast / broadcast radio bearer (MBR).

[0008] For example, the MBS service of a terminal device includes one or more of the following: MBS services that the terminal device is receiving or is interested in receiving, or MBS services that it no longer receives or is no longer interested in receiving, or MBS services that the terminal device has subscribed to, etc.

[0009] In one implementation, the first message includes a first index and a second index. The first index is used to indicate an index related to the MBS service of the terminal device. For example, the index may be an MBS service list, a frequency list (including at least one frequency point), or a priority bias (indicating whether the terminal device prioritizes MBS broadcast reception relative to unicast and MBS broadcast reception). The second index is used to indicate the intended service area (ISA) of the terminal device.

[0010] In this embodiment, in NTN communication, the wireless communication area of ​​the network device is much larger than the intended service area of ​​the MBS service. There is overlap between the wireless communication area and the intended service area of ​​the MBS service. This can lead to situations where the terminal device receives MBS services it does not need, resulting in resource waste and poor application performance. To help the network device effectively and efficiently manage MBS services, this embodiment introduces an enhancement mechanism to notify the intended service area of ​​the MBS service. This allows the network device to obtain the MBS service and the intended service area of ​​the terminal device, thereby facilitating the use of MBS services in NTN communication and enriching communication methods in NTN scenarios.

[0011] In one possible scenario of the first aspect, the intended service area of ​​the terminal device includes a first intended service area that the terminal device enters, and / or, the intended service area of ​​the terminal device includes a second intended service area that the terminal device leaves, the second intended service area includes N intended service areas associated with the MBS service, or, the second intended service area is any one of the N intended service areas associated with the MBS service.

[0012] In the above embodiments, the network device can obtain whether the terminal device enters or leaves the intended service area, so that the network device can understand the regional dynamics of the terminal device and help the network device use / apply MBS services in NTN communication according to the communication status of the terminal device. For example, only terminal devices in the intended service area can receive the corresponding MBS service, while terminal devices that have left the intended service area cannot use the MBS service, thereby improving the stability of MBS services.

[0013] In one possible implementation of the first aspect, the method further includes:

[0014] Send a first request message, wherein the first request message is used to indicate permission to send the first message.

[0015] In the above embodiments, the generation / sending of the first message can be triggered by the network device. For example, when MBS service is applied in NTN communication, the network device can send a first request message to request the first message; when MBS service is not applied in the NTN system, the first request message may not be sent, thereby making the acquisition of the first message more flexible and able to be acquired according to needs.

[0016] In one possible implementation of the first aspect, the method further includes:

[0017] If, based on the first message, it is determined that the number of terminal devices in the first intended service area associated with the MBS service is one, the data of the MBS service is transmitted in unicast mode.

[0018] In one possible implementation of the first aspect, the method further includes:

[0019] If, based on the first message, it is determined that the number of terminal devices in the first intended service area associated with the MBS service is greater than one, the data of the MBS service is transmitted in broadcast mode.

[0020] In the above embodiments, the network device can determine the data transmission mode (unicast mode or broadcast mode) of MBS service based on the content carried by the first message, so that the current data transmission mode can better serve NTN communication and save signaling overhead.

[0021] In one possible implementation of the first aspect, the method further includes:

[0022] If, based on the first message, it is determined that the first intended service area entered by the terminal device belongs to the intended service area associated with the MBS service, the session of the MBS service is activated. Further, the MBS service session is identified by a temporary mobile group identity (TMGI).

[0023] In one possible implementation of the first aspect, the method further includes:

[0024] If, based on the first message, it is determined that the first intended service area entered by the terminal device does not belong to the intended service area associated with the MBS service, then the session of the MBS service is activated.

[0025] In the above embodiments, the network device can determine whether to activate / deactivate the MBS service based on the content carried by the first message, thereby activating the MBS service when needed so that the MBS service can be applied in NTN communication; and deactivating the MBS service when not needed to save communication overhead.

[0026] In one possible implementation of the first aspect, the method further includes:

[0027] If the first message indicates a second intended service area that the terminal device has left, a second message is received, wherein the second message indicates a third intended service area that the terminal device has entered.

[0028] In the above embodiments, when the terminal device leaves, it can report its intended service area, so that the network device can understand the regional dynamics of the terminal device in a timely manner. This helps the network device to use / apply MBS services in NTN communication based on the communication status of the terminal device, thereby improving the stability of MBS services.

[0029] In one possible implementation of the first aspect, the method further includes:

[0030] If, based on the first message, it is determined that the terminal device is the last session to join the MBS service, the MBS service session is released.

[0031] In the above embodiments, the network device can determine whether there are any terminal devices in the MBS service session based on the content carried by the first message, which helps the network device release the MBS service and save communication overhead when no terminal device joins the MBS session.

[0032] In one possible implementation of the first aspect, the method further includes:

[0033] If, based on the first message and the second message, it is determined that the third intended service area does not belong to the intended service area associated with the MBS service, and it is determined that the terminal device is the last session to join the MBS service, the MBS service session is released.

[0034] In the above embodiments, the network device can determine whether there are still terminal devices in the MBS service session based on the content carried by the first message and the second message, which helps the network device release the MBS service and save communication overhead when no terminal device joins the MBS session.

[0035] In one possible implementation of the first aspect, the method further includes:

[0036] If, based on the first message and the second message, it is determined that the third intended service area belongs to the intended service area associated with the MBS service, the binding relationship between the terminal device and the second intended service area is updated to the binding relationship between the terminal device and the third intended service area.

[0037] In the above embodiments, when the terminal device leaves, it can report its intended service area, so that the network device can update the terminal device's area dynamics in a timely manner. This helps the network device use / apply MBS services in NTN communication based on the terminal device's communication status, thereby improving the stability of MBS services.

[0038] In one possible implementation of the first aspect, the method further includes:

[0039] If, based on the first message, it is determined that the first intended service area entered by the terminal device belongs to the intended service area associated with the MBS service, a third message is sent, wherein the third message is used to indicate acceptance of the terminal device joining the MBS service session.

[0040] In one possible implementation of the first aspect, the method further includes:

[0041] If, based on the first message, it is determined that the first intended service area entered by the terminal device does not belong to the intended service area associated with the MBS service, a fourth message is sent, wherein the fourth message is used to indicate that the terminal device's attempt to join the MBS service session is rejected. Further, the fourth message may also carry a reason for rejection; for example, the reason for rejection may be that the first intended service area does not belong to the intended service area associated with the MBS service.

[0042] In the above embodiments, the network device can determine whether to allow the terminal device to join the MBS service session based on the content carried by the first message. If allowed, a message can be sent to inform the terminal device that joining is allowed; if not allowed, a message can be sent to inform the terminal device that joining is not allowed. This ensures that only terminal devices in the intended service area can receive the corresponding MBS service, while terminal devices outside the intended service area cannot use the MBS service, thereby improving the stability of the MBS service.

[0043] In one possible implementation of the first aspect, the method further includes:

[0044] Send a fifth message, wherein the fifth message is used to indicate the MBS service corresponding to the first intended service area, or the intended service area associated with the MBS service.

[0045] In the above embodiments, the network device can provide a list of services available in the intended service area and / or the intended service area associated with the MBS service, to help the terminal device better use the MBS service in NTN communication.

[0046] In one possible implementation of the first aspect, the method further includes:

[0047] Based on the first message, the terminal device is removed from the MBS service session.

[0048] In the above embodiments, the network device can promptly remove terminal devices that do not require MBS services during NTN communication, saving communication / data overhead.

[0049] In one possible implementation of the first aspect, the method further includes:

[0050] If, based on the first message and the second message, it is determined that the third intended service area belongs to the intended service area associated with the MBS service, the binding relationship between the terminal device and the second intended service area is updated to the binding relationship between the terminal device and the third intended service area.

[0051] In the above embodiments, when the terminal device leaves, it can report its intended service area, so that the network device can update the terminal device's area dynamics in a timely manner. This helps the network device use / apply MBS services in NTN communication based on the terminal device's communication status, thereby improving the stability of MBS services.

[0052] In one possible implementation of the first aspect, the method further includes:

[0053] If, based on the first message and the second message, it is determined that the third intended service area does not belong to the intended service area associated with the MBS service, the terminal device is removed from the MBS service session.

[0054] In the above embodiments, the network device can promptly remove terminal devices that do not require MBS services during NTN communication, saving communication / data overhead.

[0055] In one possible implementation of the first aspect, the method further includes:

[0056] Send a sixth message, wherein the sixth message is used to indicate the MBS service corresponding to the third intended service area.

[0057] In the above embodiments, after the terminal device leaves the intended service area associated with the MBS service, and after the terminal device reports its intended service area to the network device, the network device can provide the terminal device with the MBS service under that intended service area, so that the terminal device can better use the MBS service in NTN communication and improve the user experience.

[0058] In one possible implementation of the first aspect, the MBS service of the terminal device includes MBS services related to the intended service area of ​​the terminal.

[0059] Secondly, a communication method is provided, which can be executed by a terminal device, or by a component (such as a circuit, chip, or chip system) configured in the terminal device, or by a logic module or software capable of implementing all or part of the functions of the terminal device. This application does not limit this. The following description uses a terminal device as an example.

[0060] The method includes sending a first message, wherein the first message is used to indicate the Multicast Broadcast Service (MBS) of the terminal device, and the first message is also used to indicate the intended service area of ​​the terminal device.

[0061] For example, the first message includes a first index and a second index, the first index being used to indicate MBS service related to the terminal device, and the second index being used to indicate the intended service area of ​​the terminal device.

[0062] In this embodiment, during NTN communication, the wireless communication area of ​​the network device is much larger than the intended service area of ​​the MBS service. There is overlap between the wireless communication area and the intended service area of ​​the MBS service, which may lead to situations where the terminal device receives an MBS service that it does not need, resulting in wasted resources. To help the network device effectively and efficiently manage the MBS service, this embodiment introduces an enhancement mechanism to notify the network device of the intended service area of ​​the MBS service. This allows the terminal device to report its MBS service and intended service area to the network device, thereby helping the network device utilize the MBS service in NTN communication and enriching the communication methods in NTN scenarios.

[0063] In one possible scenario of the second aspect, sending the first message includes:

[0064] When the terminal device enters the first intended service area, the first message is sent, wherein the first message is also used to indicate the first intended service area.

[0065] In another possible scenario of the second aspect, sending the first message includes:

[0066] When the terminal device leaves the second intended service area, the first message is sent, wherein the first message is further used to indicate the second intended service area, the second intended service area includes N intended service areas associated with the MBS service, or the second intended service area is any one of the N intended service areas associated with the MBS service, where N is a positive integer.

[0067] In the above embodiments, when a terminal device enters and / or leaves the intended service area, it can report its intended service area to the network device to help the network device understand the regional dynamics of the terminal device, so that the network device can make better decisions on the status of MBS services and improve the stability of MBS services.

[0068] In one possible implementation of the second aspect, the method further includes:

[0069] Receive a first request message, wherein the first request message is used to indicate permission to send the first message.

[0070] In the above embodiments, the generation / sending of the first message can be triggered by the network device. For example, when MBS service is applied in NTN communication, the network device can send a first request message to request the first message; when MBS service is not applied in the NTN system, the first request message may not be sent, which makes the acquisition of the first message more flexible and can be acquired according to needs, thereby saving the energy consumption of the terminal device.

[0071] In one possible implementation of the second aspect, the method further includes:

[0072] Send a second message, wherein the second message is used to indicate the third intended service area that the terminal device has entered.

[0073] In the above embodiments, when the terminal device leaves, it can report its intended service area, so that the network device can understand the regional dynamics of the terminal device in a timely manner. This helps the network device to use / apply MBS services in NTN communication based on the communication status of the terminal device, thereby improving the stability of MBS services.

[0074] In one possible implementation of the second aspect, the method further includes:

[0075] Receive a sixth message, wherein the sixth message is used to indicate the MBS corresponding to the third intended service area.

[0076] In the above embodiments, after the terminal device leaves the intended service area associated with the MBS service, and after the terminal device reports its intended service area to the network device, the network device can provide the terminal device with the MBS service under that intended service area, so that the terminal device can better use the MBS service in NTN communication and improve the user experience.

[0077] In one possible implementation of the second aspect, the method further includes:

[0078] A third message is received, wherein the third message is used to indicate acceptance of the terminal device joining the MBS service session.

[0079] In one possible implementation of the second aspect, the method further includes:

[0080] A fourth message is received, wherein the fourth message is used to indicate that the terminal device is denied access to the MBS service session.

[0081] In the above embodiments, the network device can determine whether to allow the terminal device to join the MBS service session based on the content carried by the first message. If allowed, a message can be sent to inform the terminal device that joining is allowed; if not allowed, a message can be sent to inform the terminal device that joining is not allowed. This ensures that only terminal devices in the intended service area can receive the corresponding MBS service, while terminal devices outside the intended service area cannot use the MBS service, thereby improving the stability of the MBS service.

[0082] In one possible implementation of the first aspect, the MBS service of the terminal device includes MBS services related to the intended service area of ​​the terminal.

[0083] In one possible implementation of the second aspect, the method further includes:

[0084] Receive a fifth message, wherein the fifth message is used to indicate the MBS service corresponding to the first intended service area, or the intended service area associated with the MBS service.

[0085] In the above embodiments, the network device can provide a list of services available in the intended service area and / or the intended service area associated with the MBS service, to help the terminal device better use the MBS service in NTN communication.

[0086] Thirdly, embodiments of this application provide a communication device, which can be a network device or a device or functional module within a network device, wherein:

[0087] The communication device includes a module for performing the method described in the first aspect or any possible implementation thereof;

[0088] Alternatively, the communication device includes a processor for performing the method described in the first aspect or any possible implementation thereof.

[0089] Fourthly, embodiments of this application provide a communication device, which can be a terminal device or a device or functional module within a terminal device, wherein:

[0090] The communication device includes a module for performing the method described in the second aspect or any possible implementation thereof;

[0091] Alternatively, the communication device includes a processor for performing the method described in the second aspect or any possible implementation thereof.

[0092] Fifthly, embodiments of this application provide a communication device, including a logic circuit and an interface, wherein the logic circuit and the interface are coupled; the interface is used for inputting and / or outputting information, wherein:

[0093] The logic circuit is used to perform the method described in the first aspect or any possible implementation thereof, or...

[0094] The logic circuit is used to perform the method described in the second aspect or any possible implementation thereof.

[0095] Sixthly, embodiments of this application provide a computer-readable storage medium for storing a computer program, wherein:

[0096] When the computer program is executed, it is capable of implementing the first aspect or any possible implementation of the first aspect, or...

[0097] When the computer program is executed, it is capable of implementing the second aspect or any possible implementation of the second aspect.

[0098] Seventhly, embodiments of this application provide a communication system, which includes a terminal device and a network device, wherein:

[0099] The network device is used to perform the method described in the first aspect or any possible implementation thereof;

[0100] The terminal device is used to execute the method described in the second aspect or any possible implementation thereof.

[0101] Eighthly, embodiments of this application provide a computer program that, when executed by a processor, causes a communication device including the processor to implement the method described in the first aspect or any possible implementation of the first aspect, or to implement the method described in the second aspect or any possible implementation of the second aspect.

[0102] Ninthly, embodiments of this application provide a chip system including logic circuitry (or, as understood, the chip system includes a processor, which may include logic circuitry, etc.) and input / output interfaces. The input / output interfaces can be used to receive messages or to send messages. For example, when the chip system is used to implement the functions of a communication device, the input / output interfaces can be used to receive first information. The input / output interfaces can be the same interface, i.e., the same interface can implement both sending and receiving functions; or, the input / output interfaces include an input interface and an output interface, where the input interface is used to implement the receiving function, i.e., to receive messages; and the output interface is used to implement the sending function, i.e., to send messages. The logic circuitry can be used to perform operations other than the sending and receiving functions described in the first aspect; the logic circuitry can also be used to transmit messages to the input / output interfaces or to receive messages from other communication devices from the input / output interfaces. The chip system can be used to implement the methods described in the first aspect or any possible implementation of the first aspect, or to implement the methods described in the second aspect or any possible implementation of the second aspect. The chip system can be composed of chips or can include chips and other discrete devices.

[0103] Optionally, the chip system may also include a memory, which can be used to store instructions, and the logic circuits can call the instructions stored in the memory to implement the corresponding functions.

[0104] It should be understood that the descriptions of technical features, technical solutions, beneficial effects, or similar language in this application do not imply that all features and advantages can be achieved in any single embodiment. Rather, it is understood that the description of a feature or beneficial effect means that a specific technical feature, technical solution, or beneficial effect is included in at least one embodiment. Therefore, the descriptions of technical features, technical solutions, or beneficial effects in this specification do not necessarily refer to the same embodiment. Furthermore, the technical features, technical solutions, and beneficial effects described in this embodiment can be combined in any suitable manner. Those skilled in the art will understand that embodiments can be implemented without one or more specific technical features, technical solutions, or beneficial effects of a particular embodiment. In other embodiments, additional technical features and beneficial effects may be identified in specific embodiments that do not embody all embodiments. Attached Figure Description

[0105] The accompanying drawings used in the embodiments of this application are described below.

[0106] Figure 1 is a schematic diagram of a communication system provided in an embodiment of this application;

[0107] Figure 2A is a schematic diagram of a transparent transmission architecture;

[0108] Figure 2B is a schematic diagram of a regenerative architecture;

[0109] Figure 3A is a schematic diagram of a multicast service scenario provided in an embodiment of this application;

[0110] Figure 3B is a schematic diagram of a broadcast service provided in an embodiment of this application;

[0111] Figure 4 is a flowchart illustrating a communication method provided in an embodiment of this application;

[0112] Figure 5 is a flowchart illustrating another communication method provided in an embodiment of this application;

[0113] Figure 6 is a flowchart illustrating another communication method provided in an embodiment of this application;

[0114] Figure 7 is a flowchart illustrating a communication method provided in an embodiment of this application;

[0115] Figure 8 is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0116] Figure 9 is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0117] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described below with reference to the accompanying drawings.

[0118] In this application, the terms "system" and "network" are used interchangeably. Unless otherwise stated, " / " indicates that the objects before and after are in an "or" relationship; for example, A / B can mean A or B. "And / or" in this application merely describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. Furthermore, in the description of this application, unless otherwise stated, "multiple" refers to two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be one or more. Furthermore, to facilitate a clear description of the technical solutions in the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish between network elements and similar items with essentially the same function. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that the terms "first" and "second" are not necessarily different.

[0119] References such as "in one implementation," "exemplarily," or "in one implementation" as described in the embodiments of this application mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0120] The following detailed embodiments further illustrate the objectives, technical solutions, and beneficial effects of this application. It should be understood that the following are merely specific embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made based on the technical solutions of this application should be included within the scope of protection of this application.

[0121] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0122] First, a brief introduction will be given to the implementation environment and application scenarios of the embodiments of this application.

[0123] The technical solution of this application can be applied to non-terrestrial networks (NTN), or scenarios where NTN and terrestrial networks (TN) are integrated. NTN systems can be, for example, satellite communication systems, high altitude platform station (HAPS) communication systems, global navigation satellite systems (GNSS), etc. TN systems can be, for example, 4th generation (4G) communication systems (e.g., long term evolution (LTE) systems), worldwide interoperability for microwave access (WiMAX) communication systems, 5th generation (5G) communication systems (e.g., new radio (NR) systems), and future mobile communication systems, etc.

[0124] Please refer to Figure 1, which is a schematic diagram of a communication system provided in an embodiment of this application. As shown in Figure 1, the communication system 10 includes a terminal device 11 and a network device 12.

[0125] In this embodiment, network device 12 can be a device on the network side used to provide network communication functions, and is sometimes also referred to as a network device or network element. Exemplarily, network device 12 has a device or module with corresponding communication functions. Network device 12 typically contains a communication module, circuit, or chip that performs the corresponding communication function. Network device 12 is also configured with program instructions for performing the corresponding communication function and corresponding program instructions. In this embodiment, network device 12 can typically be a base station (including functional units of a base station, or a combination of functional units of a base station) or a core network element.

[0126] Specifically, network device 12 is a network device in the NTN system, i.e., an NTN network device. For example, an NTN network device includes any one of an NTN base station (gNB), a drone network device, a high-altitude platform network device, an aircraft network device, or a communication balloon network device. The specific implementation of the NTN network device is not limited in this embodiment; this is just an example of a possible scenario.

[0127] As an example, network device 12 serves as a base station. A base station can be any device with wireless transceiver capabilities, including but not limited to: evolved base stations (NodeB, eNB, or e-NodeB) in Long Term Evolution (LTE), base stations (gNodeB or gNB) or transmission receiving points / transmission reception points (TRPs) in New Radio (NR), base stations in subsequent evolutions of the 3rd Generation Partnership Project (3GPP), access nodes, wireless relay nodes, and wireless backhaul nodes in Wi-Fi systems. Base stations can be: macro base stations, micro base stations, pico base stations, small cells, relay stations, or balloon stations, etc. A base station can contain one or more co-located or non-co-located Transmission Reception Points (TRPs). A base station can also be a radio controller, centralized unit (CU), and / or distributed unit (DU) in a cloud radioaccess network (CRAN) scenario. Base stations can communicate directly with terminal devices or via relay stations. Terminal devices can communicate with multiple base stations using different technologies; for example, they can communicate with base stations supporting LTE networks, base stations supporting 5G networks, or even have dual connections with both LTE and 5G base stations. In some deployments, the gNB may also include a radio unit (RU). The CU and DU implement some of the gNB's functions. For instance, the CU implements radio resource control (RRC) and packet data convergence protocol (PDCP) layer functions, while the DU implements radio link control (RLC), media access control (MAC), and physical (PHY) layer functions. Since RRC layer information ultimately becomes PHY layer information, or is derived from PHY layer information, in this architecture, higher-layer signaling, such as RRC or PDCP layer signaling, can be considered to be sent by the DU, or by the DU+RU.It is understood that network devices can be CU nodes, DU nodes, or devices that include both CU and DU nodes. Furthermore, a CU can be classified as a network device in the access network (RAN) or a network device in the core network (CN); no restrictions are placed here.

[0128] As another example, network device 12 serves as a core network (CN) unit. Core network elements can be functional units within the core network, referring to those that provide service support to terminal devices, including but not limited to Access and Mobility Management Function (AMF) units, Session Management Function (SMF) units, User Plane Function (UPF) units, and Mobility Management Entity (MME) units. Among these, the AMF unit is responsible for access management and mobility management of the terminal device; the SMF unit is responsible for session management, such as user session establishment; the UPF unit is responsible for implementing user plane functions; and the MME is responsible for signaling processing, etc.

[0129] For example, network device 12 provides services to a cell. Terminal devices communicate with the cell through transmission resources (e.g., frequency domain resources, or spectrum resources) allocated by the network device. The cell may belong to a macro base station (e.g., macro eNB or macro gNB) or to a base station corresponding to a small cell. The small cell may include: metro cell, micro cell, pico cell, femto cell, etc. These small cells have the characteristics of small coverage area and low transmission power, and are suitable for providing high-speed data transmission services.

[0130] As an example, terminal device 11 can also be called user equipment (UE), mobile station (MS), mobile terminal (MT), etc., and is a device that provides voice or data connectivity to users, or it can be an Internet of Things (IoT) device. For example, terminal devices include handheld devices with wireless connectivity, vehicle-mounted devices, etc. Currently, terminal devices can be: mobile phones, tablets, laptops, PDAs, mobile internet devices (MIDs), wearable devices (such as smartwatches, smart bracelets, pedometers, etc.), in-vehicle devices (such as cars, bicycles, electric vehicles, airplanes, ships, trains, high-speed trains, etc.), virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, smart home devices (such as refrigerators, televisions, air conditioners, electricity meters, etc.), intelligent robots, workshop equipment, wireless terminals in autonomous driving, wireless terminals in remote surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, or wireless terminals in smart homes, and flying devices (such as intelligent robots, hot air balloons, drones, airplanes), etc. Terminal devices can also be other devices with terminal functions; for example, a terminal device can also be a device that performs terminal functions in D2D communication. In this application, terminal devices with wireless transceiver functions and chips that can be installed in the aforementioned terminal devices are collectively referred to as terminal devices. Terminal devices can also be terminal devices in Internet of Things (IoT) systems. IoT is an important part of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network that connects people and machines and things.

[0131] To facilitate a clear description of the technical methods in the embodiments of this application, the following provides a brief introduction to some of the users and technologies involved in the embodiments of this application.

[0132] (1) Non-terrestrial Networks (NTN): In communication systems, Non-terrestrial Network (NTN) technology is one of the technical directions for direct satellite connection between mobile phones and terrestrial cellular communication technology, serving as an important supplement to terrestrial cellular communication technology. By integrating satellite communication networks with terrestrial 5G networks, NTN technology can provide ubiquitous coverage regardless of terrain, connecting multiple spaces including air, space, land, and sea to form an integrated ubiquitous access network, enabling on-demand access across all scenarios. Non-terrestrial networks are not limited by geographical location, achieving seamless global communication; and satellite communication networks can be flexibly deployed to quickly respond to various communication needs. Due to the advantages of global coverage and flexible deployment, non-terrestrial networks are currently widely used in various communication scenarios. Key value scenarios include areas with poor land coverage, maritime communication, public safety needs, inter-aircraft communication, and railways, aiming to provide users with mobile broadband services.

[0133] For example, HAPS in the NTN system is carried on an airborne platform, mainly including airplanes, balloons and airships, and uses the high-altitude platform station as a mobile communication base station to provide mobile services using the same frequency band as the terrestrial mobile network.

[0134] For example, the satellite communication network in the NTN system relies on a spaceborne platform, which mainly includes low earth orbit (LEO), medium earth orbit (MEO), and geostationary earth orbit (GEO) satellites.

[0135] In one implementation, based on the relationship between the satellite and the base station, it can be divided into the following two architectures:

[0136] First, the transparent payload architecture. As shown in Figure 2A, which is a schematic diagram of a transparent payload architecture, the satellite is only responsible for signal forwarding and has no data processing capabilities. The base station (gNB) is located on the ground, and the satellite is connected to the base station through a ground gateway. The signal between the UE and the base station is transmitted through the satellite, while the data processing function still resides at the base station. The scenarios and protocol stacks of the transparent payload architecture are described below. The link between the satellite and the UE is called the service link, and the link between the satellite and the base station is called the feeder link.

[0137] Second, regenerative payload architecture. As shown in Figure 2B, which is a schematic diagram of a regenerative architecture, the satellite possesses all or part of the functions of a base station, meaning the satellite can perform data processing. Specifically, it can be categorized into various forms, such as a complete base station located on the satellite, a distributed unit (DU) located on the satellite while a centralized unit (CU) is located on the ground, and so on, along with different scenarios and protocol stacks. The link between the satellite / base station and the UE is called a service link.

[0138] (2) Cell: In a communication system, a cell is described by higher layers from the perspective of resource management, mobility management, or service unit. The coverage area of ​​each network device can be divided into one or more cells, and each cell can correspond to one or more frequency points. In other words, each cell can be regarded as an area formed by the coverage area of ​​one or more frequency points.

[0139] It should be noted that a cell can be an area within the coverage range of a network device's wireless network. In the embodiments of this application, different cells can correspond to the same or different network devices. For example, the network device belonging to cell 1 and the network device belonging to cell 2 can be different network devices (such as base stations). That is, cell 1 and cell 2 can be managed by different base stations. Or, for another example, the network device managing cell 1 and the network device managing cell 2 can also be different radio frequency processing units of the same base station, such as radio remote units (RRUs). That is, cell 1 and cell 2 can be managed by the same base station, have the same baseband processing unit and intermediate frequency processing unit, but have different radio frequency processing units. Or, for yet another example, the network device belonging to cell 1 and the network device belonging to cell 2 can be the same network device (such as a base station). That is, cell 1 and cell 2 can be managed by the same base station. In this case, it can be referred to as cell 1 and cell 2 co-located. This application does not make any special limitations on this.

[0140] In some possible deployments, a base station may include a CU and a DU. In such a deployment, cell 1 and cell 2 may be managed by the same CU and the same DU, i.e., they share the same CU and the same DU; cell 1 and cell 2 may be managed by the same CU and different DUs, i.e., they share the same CU but not the same DU; cell 1 and cell 2 may also be managed by different CUs and different DUs, i.e., they do not share the same CU and do not share the same DU.

[0141] In one implementation, the interface for wireless communication between the first device 11 (e.g., a terminal device) and the second device 12 (e.g., a base station) shown in Figure 1 includes a Uu interface. A cell can also be called a Uu cell. A Uu cell refers to the wireless area covered by the base station that establishes a connection with the terminal device through the Uu interface.

[0142] In another implementation, within the NTN system, a cell refers to an NTN cell, specifically an area providing wireless coverage via non-terrestrial equipment such as satellites or high-altitude platforms. For example, based on the location of a building within the ground coverage area of ​​an NTN cell, NTN cells can be categorized into at least three types:

[0143] Earth-fixed: The coverage area of ​​this type of NTN cell is fixed to a specific area on the ground, i.e., continuous fixed-point coverage. The NTN cells provided by GEO satellites are of this type.

[0144] Quasi-earth-fixed: The coverage area of ​​this type of NTN cell is fixed to a certain area on the ground for a period of time, and then it will be changed to another area on the ground after a period of time, that is, fixed-point coverage for a certain period of time. LEO satellites and MEO satellites can provide this type of NTN cell.

[0145] Earth-moving: The coverage area of ​​this type of NTN cell slides across the ground. LEO and MEO satellites can provide this type of NTN cell.

[0146] (3) Multicast Broadcast Service (MBS) is a network communication service mainly used to efficiently transmit data to multiple receivers. It is widely used in multimedia transmission, routing protocols, Internet of Things (IoT), vehicle networking, etc.

[0147] For example, the MBS service process is as follows: The data server can send MBS data to the core network equipment. After receiving the MBS data, the core network equipment can send the MBS data to the base station. Then, after receiving the MBS data, the base station can send the MBS data to the UE. When the core network equipment sends MBS data to the base station, the MBS data can be transmitted through a common transmission channel MBS session. Each MBS session can contain at least one MBS quality of service (QoS) stream. When the base station sends MBS data to the UE, the MBS data can be transmitted through the MBS radio bearer.

[0148] In one implementation, for MBS radio bearers, there are at least two transmission modes: the first can be point-to-multipoint (PTM) transmission; the second can be point-to-point (PTP) transmission. Based on these two transmission modes, MBS services include multicast and broadcast services.

[0149] For example, in the embodiments of this application, multicast can also be referred to as multicast. Multicast service refers to sending data to multiple UEs within a subscription group, allowing only devices that have joined the multicast group to receive the content, and UEs need to actively join or leave the multicast group.

[0150] For example, broadcasting refers to sending data to all UEs within the coverage area, which the devices can passively receive regardless of whether the users have subscribed. The network can directly push data without requiring a UE response or subscription.

[0151] For example, at the core network level, MBS transmission refers to sending MBS service data to terminal devices through an MBS session. Between network elements, multicast transmission refers to a tunnel established for multicast between the source and destination network elements (one possibility is that the destination network element's IP address is a multicast IP address; another possibility is that the destination network element receives data sent by the source network element by joining a multicast tree). For the air interface, air interface MBS transmission refers to a single service data sent by an access network device, which can be received simultaneously and / or on the same frequency by multiple terminal devices.

[0152] Please refer to Figure 3A, which is a schematic diagram of a multicast service scenario provided by an embodiment of this application. As shown in Figure 3A, in the multicast service, the network side creates an MBS session and sends a service announcement to the UEs (including but not limited to UE1 and UE2) within the multicast group. At time T1, a UE (e.g., UE1) in the multicast group joins the session, and a session is established between UE1 and the network. During the session establishment phase, the network side can transmit MBS data with the UE, that is, send MBS data to UE1. At time T2, a UE (e.g., UE2) in the multicast group also joins the session, and a session is established between UE2 and the network. At the session establishment node, the network side can send MBS data to UE2. As can be seen from Figure 3A, at this time, both UE1 and UE2 are in the session, and the network side can send MBS data to both UE1 and UE2. At time T3, UE1 leaves the session, and the network device sends MBS data to UE2. At time T4, UE2 leaves the session. After time T4, if the network side detects that UE2 is the last UE to join the session, it deletes the MBS session. Alternatively, multicast can also be called groupcast.

[0153] Please refer to Figure 3B, which is a schematic diagram of a broadcast service provided in an embodiment of this application. As shown in Figure 3B, the network side starts broadcasting a service announcement. During the broadcast service announcement period (i.e., from the start of the broadcast service announcement to the end of the broadcast service announcement), all UEs within the coverage area (e.g., UEs in the local service active state) can receive broadcast data. As can be seen from Figure 3B, before the start of service session 1, UE1 is in the local service active state. When the service session starts, UE1 in the active state can receive broadcast data transmitted through service session 1. During the start of service session 1, UE2 in the active state can receive broadcast data transmitted through service session 1. Before the start of service session 2, UE2 is in the local service deactivated state. UE2 in the deactivated state cannot receive broadcast data transmitted through service session 2. When service session 2 starts, UE2 is in the active state. UE2 in the active state can receive broadcast data transmitted through service session 2. After the end of service session 2, if UE2 is the last UE in the active state within the coverage area, the network side can stop broadcasting the service announcement after UE2 switches from the active state to the deactivated state.

[0154] Generally, MBS services have associated intended service areas (ISAs). An ISA refers to the geographical area or logical group to which the MBS service is planned to cover, dynamically or statically configured by the network side (e.g., PCF). In technical implementations, the definition of a geographical area includes, but is not limited to, cell-level coverage, area identifiers, and geographical boundaries. Cell-level coverage refers to mapping the ISA to one or more cells based on the physical coverage area of ​​the base station. For example, multiple cells within a stadium jointly form an ISA for live broadcasting of events. Area identifiers refer to the boundaries of the ISA defined by the core network through tracking areas (TAs) or network slice identifiers. For example, emergency alerts only broadcast a list of TAs for disaster-affected areas. Geographical boundaries refer to the geographical coordinate range, i.e., the boundaries defined based on global positioning system (GPS) / BeiDou coordinates (such as rectangles, polygons, etc.). Logical groups are used to identify a set of UEs subscribing to the same MBS service through temporary mobile group identities (TMGIs). For example, a TMGI group of paying users has an ISA that represents the set of cells where these users are currently located. It is understood that the ISA range can be expanded or contracted based on UE mobility.

[0155] In summary, in an NTN system, the coverage area of ​​a single NTN cell can typically reach hundreds of thousands of square kilometers. The intended service area for MBS services is usually smaller than the coverage area of ​​an NTN cell, and there is overlap between the coverage area of ​​an NTN cell and the intended service area of ​​MBS services. Therefore, when network devices in an NTN system distribute MBS services, there may be situations where terminal devices that do not require MBS services also receive MBS data, leading to poor application of MBS services in NTN communication. Effectively managing MBS services in NTN communication is a pressing issue that needs to be addressed.

[0156] In view of this, embodiments of this application provide a communication method in which the network side can manage / control sessions related to MBS services based on the intended service area reported by the terminal device. This allows terminal devices within the intended service area associated with the MBS service to use the MBS service, while terminal devices outside the intended service area cannot use the MBS service. This enables accurate management of the MBS service and improves the feasibility of applying the MBS service in NTN communication.

[0157] The embodiments of this application are not limited to NTN scenarios, but can also be applied to other scenarios where the intended area of ​​Multicast Broadcast Service (MBS) is smaller than the coverage area of ​​an NTN cell. The aforementioned network equipment (e.g., base stations) can be located on the ground and connected to the satellite through a gateway (transparent transmission structure), or they can be located directly on the satellite (regenerative architecture).

[0158] Please refer to Figure 4, which is a flowchart illustrating a communication method provided in an embodiment of this application. This method can be implemented based on the architecture shown in Figure 1, Figure 2A, or Figure 2B. The method includes step S400, which is described below.

[0159] Step S400: The terminal device sends a first message to the network device. The first message indicates the MBS service of the terminal device and also indicates the intended service area of ​​the terminal device. Correspondingly, the network device receives the first message.

[0160] In one implementation, the first message includes a first index and a second index. The first index indicates an index related to the MBS service of the terminal device. For example, the index could be an identifier in an MBS service list; it could be a frequency point in a frequency list, which might correspond to a specific MBS service; or it could be a priority bias, indicating whether unicast, broadcast, or multicast services are received preferentially. The second index indicates the intended service area of ​​the terminal device. For example, the second index could be an index in an intended service area list.

[0161] For example, as can be seen from the above, the MBS service of a terminal device includes MBS services related to the intended service area of ​​the terminal device. Further, the MBS service includes multicast services and broadcast services. In the broadcast MBS service, the MBS service of the terminal device refers to at least one MBS service that the terminal device is interested in or is currently receiving, or an MBS service that it no longer receives / is no longer interested in receiving. As another example, in the multicast MBS service, the MBS service of the terminal device refers to at least one MBS service that the terminal device has subscribed to.

[0162] For example, an MBS service is associated with at least one intended service area. That is, the network device can maintain an MBS session area mapping table, which provides a list of intended service area identifiers related to MBS broadcast sessions included in the MBS session information list. It is understood that the MBS session area mapping table can define the geographical area identifiers covered by a particular MBS broadcast session (such as live broadcast or emergency communication). The intended service area identifiers are used to identify the service range.

[0163] In one implementation, upon the terminal device entering a first intended service area, a first message is sent, wherein the first message further indicates the first intended service area. Exemplarily, the intended service area of ​​the terminal device includes the first intended service area the terminal device has entered. As an example, the first intended service area where the terminal device is located / enters can be understood as the terminal device entering a new intended service area unrelated to the MBS. As yet another example, the first intended service area where the terminal device is located / enters can be understood as the terminal device entering an intended service area associated with the MBS service. Further, the first intended service area can be used to indicate the current geographical location / geographical area of ​​the terminal device.

[0164] In another implementation, when the terminal device leaves the second intended service area, the first message is sent, wherein the first message is further used to indicate the second intended service area. Exemplarily, the intended service area of ​​the terminal device includes the second intended service area that the terminal device has left, wherein the second intended service area includes N intended service areas associated with the MBS service, or the second intended service area is any one of the N intended service areas associated with the MBS service, where N is a positive integer. Further, the N intended service areas associated with the MBS service may be all intended service areas corresponding to all identifiers in the intended service area identifier list previously sent by the network device to the terminal device and associated with a particular MBS broadcast session.

[0165] As an example, the second intended service area that the terminal device has left / is not in can be used to indicate that the current geographic location / region of the terminal device is not / does not belong to the location / region indicated by the second intended service area. In one implementation, the second intended service area that the terminal device has left includes all intended service areas associated with the MBS service. In another implementation, the second intended service area that the terminal device has left is any one of the intended service areas associated with the MBS service.

[0166] In one possible implementation, the network device may also send a first request message to the terminal device. This first request message instructs the terminal device to determine its current / entered intended area, or its absent / left intended area. The first request message also requests the terminal device to collect statistics on MBS services of interest or currently being received. In one implementation, during MBS service transmission, the first request message sent by the network device to the terminal device may be carried in a system information block (SIB), or it may be carried in a message transmitted in broadcast format.

[0167] In one implementation, the terminal device receives a first request message from the network device, and in response to the first request message, if the intended service area changes (for example, entering a first intended area), sends a first message to the network device. The first message is used to indicate the first intended service area where the terminal device is located.

[0168] In another implementation, the terminal device receives a first request message from the network device. In response to the first request message, if the terminal device leaves the second intended area, it can indicate that the terminal device has left all intended service areas associated with the MBS service. The first message is used to indicate the second intended service area that the terminal device has left.

[0169] In another implementation, the terminal device receives a first request message from the network device and, in response to the first request message, sends a first message to the network device if the intended service area is not the intended service area associated with the MBS service. The first message is used to indicate the first intended service area where the terminal device is located.

[0170] For example, suppose the MBS service associated with the terminal device indicated by the first message includes a first MBS service, and the intended service area associated with the first MBS service includes intended service area 1, intended service area 2, and intended service area 3. When the terminal device leaves intended service area 1, intended service area 2, and intended service area 3, a first message indicating departure from the intended service area associated with the first MBS service and the MBS service associated with the terminal device is sent to the network device. Alternatively, when the terminal device leaves intended service area 1, intended service area 2, or intended service area 3, a first message indicating departure from intended service area 1, intended service area 2, or intended service area 3 and the MBS service associated with the terminal device is sent to the network device.

[0171] In another possible implementation, during multicast service, the terminal device needs to actively join the MBS session. Upon joining the MBS session, the terminal device sends a first message to the network device, indicating the first intended service area where the terminal device is located. Upon leaving the second intended service area, the terminal device sends a first message to the network device, indicating the second intended service area it has left.

[0172] In this embodiment, the network device can also send a list of intended service areas (ISAs) and the corresponding index values ​​(ISA identifiers, ISA IDs) to terminal devices within the coverage area via system messages. That is, the list of intended service areas includes at least one index value corresponding to an intended service area. Further, the terminal device can determine its current intended service area or the intended service area it has left by combining its current coordinates with the list of intended service areas provided by the network device. Even further, the terminal device can report to the network device its current first intended service area / the index number corresponding to the first intended service area, or its left second intended service area / the index number corresponding to the second intended service area.

[0173] In this embodiment, during the broadcast service notification process, the network device can broadcast a list of currently available MBS services to the terminal device via system messages or dedicated signaling. Each MBS service in the list can correspond to an index value (such as a numeric identifier, ID). For example, the MBS service list may include, but is not limited to, a first MBS service, a second MBS service, and a third MBS service. The first MBS service corresponds to index number 1, the second MBS service corresponds to index number 3, and the third MBS service corresponds to index number 4. Further, after receiving the MBS service list, the terminal device can maintain a "list of services of interest" according to its own needs (such as user configuration, application requests, etc.), saving the index values ​​of the MBS services to be received. In one implementation, when the network device broadcasts data, the terminal device can quickly determine whether it needs to receive the currently transmitted service content through index matching. In another implementation, when a user selects a service through the application layer (such as clicking: watch live stream), the terminal device can generate a multicast subscription. Furthermore, the terminal device can report MBS services related to the terminal device to the network device, such as MBS services that the terminal device is interested in, is receiving, or has subscribed to. Moreover, the terminal device can send an MBS service index to the network device.

[0174] In one implementation, the network device can send the list of available MBS services and the list of intended service areas to the terminal device in the same message; that is, the list of available MBS services and the list of intended service areas can be contained in the same message.

[0175] As an example, a large geographical area (such as the coverage area of ​​an NTN cell) can be divided into multiple geographical regions. Each geographical region represents a continuous ground geographical area defined by a geometric shape, such as a square, rectangle, quadrilateral, or general polygon. In one implementation, a large ground geographical area can also be divided into geographical regions of the same size. Optionally, in another implementation, a large ground geographical area can be divided into geographical regions of different sizes; this application does not impose any limitations on this. In the embodiments of this application, each geographical region can be regarded as an intended service area. Furthermore, various attributes can be used to represent the intended service area, such as using a bounding box of latitude and longitude coordinates, or using an identifier (or index) of the geographical area, the name of the geographical area (such as Hubei Province), and a description of the boundary of the geographical area. For ease of understanding, this application mainly uses the index (ID) of the intended service area as an example for illustrative explanation. It should be understood that in this application, one intended service area corresponds to one ID, but one ID may correspond to multiple intended service areas. The correspondence between intended service areas and IDs can be predefined by the protocol or configured by the core network elements. This application does not impose any restrictions on this.

[0176] Please refer to Figure 5, which is a flowchart of another communication method provided in an embodiment of this application. The method can be implemented based on the architecture shown in Figure 1, Figure 2A or Figure 2B. The method includes steps S500 to S501, and each step is described below.

[0177] Step S500: The terminal device sends a first message to the network device. The first message indicates the MBS service related to the terminal device and indicates the first intended service area that the terminal device has entered. Correspondingly, the network device receives the first message.

[0178] In one implementation, during broadcast services, when a terminal device enters a first intended service area, the terminal device sends a first message to the network device to report the MBS services it is interested in or is currently receiving, as well as the intended service area it is currently in (i.e., the first intended service area).

[0179] For example, other descriptions of step S500 can be found in the relevant descriptions of step S400, and will not be repeated here.

[0180] Step S501: The network device performs a first operation on the MBS service based on the first message.

[0181] For example, a network device may provide at least one or more MBS services to a terminal device, each MBS service having at least one intended service area associated with it. The network device may perform corresponding operations on the MBS service corresponding to the intended area (i.e., the first intended area) where the terminal device is located, based on the information reported by the terminal device (i.e., the content carried in the first message).

[0182] For example, as can be seen from the foregoing, MBS services include multicast and broadcast services. In one scenario, under broadcast service, the network device can perform a first operation on the MBS session based on a first message. The first operation performed on the MBS session includes, but is not limited to: determining the mode for sending MBS data (e.g., unicast mode and multicast mode), and determining whether to activate / deactivate the MBS service session. Further, the MBS service session is identified by a service-related identifier (e.g., TMGI).

[0183] In one possible implementation, after receiving a first message from a terminal device, the network device can determine the number of terminal devices that need to use / receive the MBS service within the effective area (i.e., the intended service area associated with the MBS service) based on the content indicated by the first message. In one implementation, if the number of terminal devices in / within the first intended service area associated with the MBS service is determined to be one based on the content indicated by the first message, the mode for sending MBS data is determined to be unicast mode, and therefore the MBS service data can be transmitted in unicast mode. In another implementation, if the number of terminal devices in the first intended service area associated with the MBS service is determined to be greater than one based on the first message, the mode for sending MBS data is determined to be broadcast mode, and therefore the MBS service data can be transmitted in broadcast mode.

[0184] In this application embodiment, the network device maintenance has a first list, which includes MBS services and their associated / corresponding intended service areas. It is understood that the number of MBS services in the first list can be dynamically adjusted according to demand (such as the instructions of the core network elements), and the intended service area associated with each MBS service can also be dynamically adjusted according to demand. This application does not impose any restrictions on this.

[0185] For example, suppose the MBS service that the terminal device indicated by the first message is interested in or is receiving includes the first MBS service, and the first intended service area where the indicated terminal device is located is intended service area 1. Based on the first message and the first list, the network device can determine that the intended service areas associated with the first MBS service include intended service area 1, intended service area 2, and intended service area 4, and can also determine that the first intended service area where the terminal device is located is intended service area 1 associated with the first MBS service. A network device can receive a first message reported by at least one terminal device. In one implementation, assuming the first terminal device reports a first message 1 and the second terminal device reports a message 2, the first message 1 is used to indicate that the MBS service that the first terminal device is interested in or is receiving includes the first MBS service, and is also used to indicate that the first terminal device is located in the intended service area 3. The first message 2 is used to indicate that the MBS service that the second terminal device is interested in or is receiving includes the first MBS service, and is also used to indicate that the second terminal device is located in the intended service area 1. It can be seen that the first terminal device is not located in the intended area associated with the first MBS service. That is, if the network device can determine based on at least one first message that only one terminal device (i.e., the second terminal device) is located in the intended service area (i.e., intended service area 1) associated with the first MBS service, then the network device can determine that the mode of sending MBS data is unicast mode. In another implementation, suppose the first terminal device reports a first message 1 and the second terminal device reports a message 2. The first message 1 is used to indicate that the MBS service that the first terminal device is interested in or is receiving includes the first MBS service, and is also used to indicate that the first terminal device is located in the intended service area 2. The first message 2 is used to indicate that the MBS service that the second terminal device is interested in or is receiving includes the first MBS service, and is also used to indicate that the second terminal device is located in the intended service area 1. It can be seen that both the first terminal device and the second terminal device are located in the intended area associated with the first MBS service. That is, when the network device determines, based on at least one first message, that more than one terminal is located in the intended service area associated with the first MBS service, the network device can determine that the mode of sending MBS data is broadcast mode.

[0186] In another possible implementation, the network device can provide at least one MBS service. When the network device determines, based on a first message, that the first intended service area where the terminal device is located belongs to the intended service area associated with the MBS service, it can activate the MBS service session and then transmit the MBS session data to the terminal device in unicast or multicast mode.

[0187] In another possible implementation, the network device can provide at least one MBS service. If it is determined based on the first message that the first intended service area where the terminal device is located does not belong to the intended service area associated with the MBS service, it means that the terminal device cannot receive the data of the MBS service. In order to save costs, the MBS service session can be deactivated.

[0188] Please refer to Figure 6, which is a flowchart illustrating another communication method provided in an embodiment of this application. This method can be implemented based on the architecture shown in Figure 1, Figure 2A, or Figure 2B. The method includes steps S600 to S601, which are described below.

[0189] Step S600: The terminal device sends a first message to the network device. The first message indicates the MBS service of the terminal device and indicates the first intended service area that the terminal device enters. Correspondingly, the network device receives the first message.

[0190] In one implementation, during multicast service, when a terminal device enters the first intended service area, the terminal device sends a first message to the network device to report the MBS service it has subscribed to and the intended service area it is currently in (i.e., the first intended service area).

[0191] For example, other descriptions of step S600 can be found in the relevant descriptions of step S400, and will not be repeated here.

[0192] Step S601: The network device sends an indication message to the terminal device. The indication message is used to indicate whether to accept or reject the terminal device's session to join the MBS service.

[0193] In one scenario, under multicast service, the network device performs a first operation on the MBS session based on the first message. The first operation performed on the MBS session includes, but is not limited to: accepting the terminal device to join the MBS session, rejecting the terminal device to join the MBS session, etc.

[0194] In one possible implementation, after receiving a first message from a terminal device, the network device can determine, based on the content indicated by the first message, whether the first geographical area where the terminal device is located / entered is within the geographical area associated with the MBS service. In one implementation, if the network device determines, based on the first message, that the first intended service area where the terminal device is located belongs to the intended service area associated with the MBS service, it sends a third message to the terminal device, wherein the third message indicates acceptance of the terminal device joining the MBS service session. Correspondingly, the terminal device receives the third message. In another implementation, if the network device determines, based on the first message, that the first intended service area where the terminal device is located does not belong to the intended service area associated with the MBS service, it sends a fourth message to the terminal device, wherein the fourth message indicates rejection of the terminal device joining the MBS service session. Correspondingly, the terminal device receives the fourth message. Furthermore, when the network device sends a fourth message to the terminal device to indicate rejection of joining the MBS session, the network device may also send a rejection reason to the terminal device, or the fourth message may also carry a rejection reason, for example, the rejection reason may be that the first geographical area where the terminal device is located is not within the geographical area associated with the MBS service.

[0195] For example, suppose the MBS service subscribed to by the terminal device indicated by the first message includes the first MBS service, and the first intended service area where the indicated terminal device is located is intended service area 1. Based on the first message and the first list, the network device can determine that the intended service areas associated with the first MBS service include intended service area 1, intended service area 2, and intended service area 4, and can also determine that the first intended service area where the terminal device is located is intended service area 1 associated with the first MBS service. The network device can receive a first message reported by at least one terminal device. In one implementation, suppose the first terminal device reports first message 1, and the second terminal device reports message 2. First message 1 is used to indicate that the MBS service subscribed to by the first terminal device includes the first MBS service, and is also used to indicate that the first terminal device is located in intended service area 3. First message 2 is used to indicate that the MBS service subscribed to by the second terminal device includes the first MBS service, and is also used to indicate that the second terminal device is located in intended service area 1. It can be seen that the first terminal device is not located in the intended area associated with the first MBS service, while the second terminal device is located in the intended area associated with the first MBS service. The network device can send a fourth message to the first terminal device and a third message to the second terminal device.

[0196] In this implementation, the network device may further send a fifth message to the terminal device, the fifth message being used to indicate the MBS service corresponding to the first intended service area (i.e., the list of available MBS services), or the intended service area associated with the MBS service subscribed to by the terminal device.

[0197] Please refer to Figure 7, which is a flowchart illustrating a communication method provided in an embodiment of this application. This method can be implemented based on the architecture shown in Figure 1, Figure 2A, or Figure 2B. The method includes, but is not limited to, steps S700 to S701, which are described below.

[0198] Step S700: The terminal device sends a first message to the network device. The first message indicates MBS services related to the terminal device and also indicates the second intended service area that the terminal device has left. Correspondingly, the network device receives the first message.

[0199] In one implementation, when a terminal device leaves one of the N intended service areas associated with the MBS service, a first message is sent to the network device. The first message indicates the MBS service associated with the terminal device. The first message is also used to indicate that the terminal device leaves the MBS area (i.e., the second intended service area, which includes the N intended service areas associated with the MBS service).

[0200] In another implementation, when the terminal device leaves any one of the N intended service areas associated with the MBS service, a first message is sent to the network device. The first message indicates the MBS service associated with the terminal device. The first message is also used to indicate that the terminal device leaves the current intended service area (i.e., the second intended service area, which includes any one of the N intended service areas associated with the MBS service).

[0201] For example, the description of "the first message is used to indicate MBS services related to the terminal device and the first message is also used to indicate the second intended service area that the terminal device has left" in step S700 can be referred to step S400, and will not be repeated here.

[0202] Step S701: The network device performs a first operation on the MBS service based on the first message.

[0203] For example, a network device may provide at least one MBS service to a terminal device, each MBS service having at least one intended service area associated with it. The network device may perform corresponding operations on the MBS service related to the intended area (i.e., the second intended area) that the terminal device has left, based on information reported by the terminal device (i.e., the content carried in the first message).

[0204] For example, as can be seen from the foregoing, MBS services include multicast services and broadcast services. In one scenario, under broadcast services, the network device performs a first operation on the MBS service based on a first message. The first operation performed on the MBS service includes, but is not limited to: releasing the MBS service session, updating the binding relationship between the terminal device and the intended service area, etc.

[0205] In one possible implementation, the network device determines to release the MBS session based on the first message, i.e., performs session release-related operations, such as the broadcast / multicast service center sending a session termination request to the core network, which may carry the service index and release reason. The core network can forward the release request to the access network node, triggering the release of radio resources. The access network node can stop scheduling broadcast / multicast channels, release allocated frequency resources, update system messages (such as SIB13 / SIB20), and notify the terminal device of MBS service termination. The access network returns a session terminal response to the core network node, confirming that the resources have been released. After detecting the termination of MBS service, the terminal device can stop receiving MBS service data, release the context associated with the MBS service, and update the service list.

[0206] In one implementation, if the first message is used to instruct the terminal device to leave all intended service areas associated with the MBS service, and if the first message determines that the terminal device is the last terminal device to join the MBS session, then the network device can release the MBS service session.

[0207] For example, suppose the MBS service associated with the terminal device indicated by the first message includes the first MBS service, and the intended service areas associated with the first MBS service include intended service area 1, intended service area 2, and intended service area 3. After the network device determines, based on the first message, that the terminal device has left intended service area 1, intended service area 2, and intended service area 3, and no other terminal device joins the first MBS service, the network device can determine that the terminal device can be considered the last terminal device to join the first MBS service, and the network device can release the first MBS service session (referred to as the MBS session).

[0208] Optionally, the terminal device may send a second message to the network device, indicating the intended service area (i.e., the third intended service area) where the terminal device is currently located. The network device may send a sixth message to the terminal device, indicating at least one MBS service corresponding to the third intended service area, i.e., an MBS service list. In this way, the terminal device can obtain the MBS services that can be received in its current intended service area.

[0209] In another implementation, if the first message indicates that the terminal device is leaving its current intended service area, the terminal device can also send a second message to the network device, indicating the third geographical area where the terminal device is currently located. Further, the network device receives the first and second messages from the terminal device. If, based on the first and second messages, it determines that the third intended service area is not part of the intended service area associated with the MBS service, and determines that the terminal device is the last session to join the MBS service, the network device can release the MBS service session.

[0210] In another implementation, if it is determined based on the first and second messages that the third intended service area belongs to the intended service area associated with the MBS service, the binding relationship between the terminal device and the second intended service area is updated to the binding relationship between the terminal device and the third intended service area.

[0211] For example, suppose the MBS service associated with the terminal device indicated by the first message includes a first MBS service, and the intended service areas associated with the first MBS service include intended service area 1, intended service area 2, and intended service area 3. Based on the first message, the network device determines that the terminal device has left intended service area 1. In one implementation, the network device determines, based on a second message, that the terminal device is currently located in intended service area 2. It can be seen that intended service area 2 is still a valid area for the MBS service. Therefore, the network device can update the binding relationship, changing the binding relationship from terminal device and intended service area 1 to terminal device and intended service area 2. If it receives a message indicating that no other terminal device has joined the first MBS service, the network device can determine that this terminal device can be considered the last terminal device to join the first MBS service, and the network device can release the first MBS service session (referred to as the MBS session). In another implementation, after the network device determines based on the second message that the terminal device is currently located in the intended service area 4, it can be seen that the intended service area 4 is not a valid area for the MBS service. After the network device determines based on the first message that the terminal device has left the intended service area 1, and no other terminal device joins the first MBS service, the network device can determine that the terminal device can be considered the last terminal device to join the first MBS service. Therefore, the network device can release the first MBS service session (abbreviated as MBS session).

[0212] Optionally, the network device may send a sixth message to the terminal device, which indicates at least one MBS service corresponding to the third intended service area, i.e., an MBS service list. In this way, the terminal device can obtain the MBS services that can be received in its current intended service area.

[0213] In another scenario, under multicast services, the network device performs a first operation on the MBS service based on the first message. The first operation performed on the MBS service includes, but is not limited to: removing the terminal device from the MBS service session and updating the binding relationship between the terminal device and the intended service area.

[0214] In one possible implementation, the network device removes the terminal device from the MBS service session. The removal process includes the following: the SMF network element modifies the member list of the MBS session, removes the context of the terminal device, stops copying multicast data to the UE via the UPF, updates multicast group membership information, and may trigger resource release. The SMF / AMF stops sending multicast data to the terminal device through the access network element (e.g., gNB) via the interface, and releases the radio bearer associated with the terminal device.

[0215] In one implementation, when the first message is used to instruct the terminal device to leave all intended service areas associated with the MBS service, i.e., the second intended service area includes all intended service areas associated with the MBS service, the network device can remove the terminal device from the MBS service session.

[0216] Optionally, the terminal device may send a second message to the network device, indicating the intended service area (i.e., the third intended service area) where the terminal device is currently located. The network device may send a sixth message to the terminal device, indicating at least one MBS service corresponding to the third intended service area, i.e., an MBS service list. In this way, the terminal device can obtain the MBS services that can be received in its current intended service area.

[0217] In another implementation, if the first message indicates that the terminal device is leaving its current intended service area, the terminal device can also send a second message to the network device, indicating its current third geographical area. Further, upon receiving the first and second messages from the terminal device, if the network device determines, based on the first and second messages, that the third intended service area is not associated with the MBS service, it can remove the terminal device from the MBS service session. Further, if, based on the first and second messages, the network device determines that the third intended service area is not associated with the MBS service, and determines that the terminal device was the last session to join the MBS service, the network device can release the MBS service session.

[0218] In another implementation, if it is determined based on the first message and the second message that the third intended service area belongs to the intended service area associated with the MBS service, the binding relationship between the terminal device and the second intended service area is updated to the binding relationship between the terminal device and the third intended service area.

[0219] Optionally, the network device may send a sixth message to the terminal device, which indicates at least one MBS service corresponding to the third intended service area, i.e., an MBS service list. In this way, the terminal device can obtain the MBS services that can be received in its current intended service area.

[0220] It should be understood that the steps in the above-described method embodiments provided in this application can be implemented by integrated logic circuits in the processor hardware or by instructions in software form. The method steps disclosed in the embodiments of this application can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules in the processor.

[0221] This application divides the communication device into functional modules according to the above method embodiments. For example, each function can be divided into its own functional modules, or two or more functions can be integrated into one processing module. The integrated modules can be implemented in hardware or as software functional modules. It should be noted that the module division in this application is illustrative and only represents one logical functional division; other division methods may be used in actual implementation. The communication device of the embodiments of this application will be described in detail below with reference to Figures 8 and 9.

[0222] Figure 8 is a schematic diagram of a communication device provided in an embodiment of this application. As shown in Figure 8, the communication device includes a transceiver module 802. In one implementation, the communication device may further include a processing module 801. The transceiver module 802 can implement corresponding communication functions; for example, the transceiver module 802 may also be called an interface, communication interface, or communication module. The processing module 801 is used for data processing, such as generating information. The transceiver module 802 may have its own control logic or may execute corresponding operations under the control of the processing module 801. In some embodiments of this application, the communication device can be used to execute the actions performed by the sending end in the above method embodiments. For example, the sending end may be the device itself or a chip or functional module configurable in the device. The transceiver module 802 is used to execute operations related to information transmission and reception in the above method embodiments, and the processing module 801 is used to execute operations related to data processing in the above method embodiments. The processing module 801 can execute corresponding operations by calling a computer program or by executing corresponding operations through corresponding hardware circuits. The transceiver module 802 can perform transceiver operations independently, or it can perform corresponding transceiver operations under the control of the processing module 801.

[0223] For example, the communication device 80 shown in FIG8 can be a network device in an NTN system or a component in such a network device. The transceiver module 802 in the communication device 80 can perform the following operations:

[0224] The transceiver module 802 is used to receive a first message, wherein the first message is used to indicate the multicast broadcast service (MBS) of the terminal device, and the first message is also used to indicate the intended service area of ​​the terminal device.

[0225] For example, the first message includes a first index and a second index, the first index being used to indicate MBS services related to the terminal device, and the second index being used to indicate the intended service area of ​​the terminal device.

[0226] In one scenario, the intended service area of ​​the terminal device includes a first intended service area where the terminal device is located, and / or, the intended service area of ​​the terminal device includes a second intended service area where the terminal device leaves, the second intended service area includes N intended service areas associated with the MBS service, or, the second intended service area is any one of the N intended service areas associated with the MBS service, where N is a positive integer.

[0227] In one implementation, the processing module 801 in the communication device 80 is used to generate a first request message, and the transceiver module 802 is used to send the first request message, wherein the first request message is used to request the sending of a first message.

[0228] As an example of a scenario, in the broadcast service of MBS, the first message is used to instruct the terminal device to enter the first intended service area.

[0229] In one possible implementation of this scenario, the processing module 801 is specifically used to: transmit MBS service data in unicast mode when the number of terminal devices in the first intended service area associated with the MBS service is determined to be one based on the first message.

[0230] In one possible implementation of this scenario, the processing module 801 is specifically used to: transmit MBS service data in broadcast mode when the number of terminal devices in the first intended service area associated with the MBS service is greater than one, based on the first message.

[0231] In one possible implementation of this scenario, the processing module 801 is specifically used to: activate the MBS service session when it is determined based on the first message that the first intended service area entered by the terminal device belongs to the intended service area associated with the MBS service.

[0232] In one possible implementation of this scenario, the processing module 801 is specifically used to: activate the MBS service session when it is determined based on the first message that the first intended service area entered by the terminal device does not belong to the intended service area associated with the MBS service.

[0233] As another example of a scenario, in the broadcast service of MBS, the first message is used to indicate the second intended service area that the terminal device has left.

[0234] As one possible implementation in this scenario, the transceiver module 802 is also used to receive a second message, wherein the second message is used to indicate the third intended service area entered by the terminal device.

[0235] In one possible implementation of this scenario, the processing module 801 is specifically used to: release the MBS service session when it is determined, based on the first message and the second message, that the third intended service area does not belong to the intended service area associated with the MBS service, and the terminal device is the last session to join the MBS service.

[0236] In one possible implementation of this scenario, the processing module 801 is specifically used to: when it is determined based on the first message and the second message that the third intended service area belongs to the intended service area associated with the MBS service, update the binding relationship between the terminal device and the second intended service area to the binding relationship between the terminal device and the third intended service area.

[0237] In one possible implementation of this scenario, the processing module 801 is specifically used to: release the MBS service session when it is determined, based on the first message and the second message, that the third intended service area does not belong to the intended service area associated with the MBS service, and the terminal device is the last session to join the MBS service.

[0238] As another example of a scenario, in the multicast service of MBS, the first message is used to indicate the first intended service area that the terminal device enters.

[0239] As one possible implementation in this scenario, if it is determined based on the first message that the first intended service area entered by the terminal device belongs to the intended service area associated with the MBS service, the transceiver module 802 is further configured to: send a third message, wherein the third message is used to indicate that the terminal device accepts the session of joining the MBS service.

[0240] As another possible implementation in this scenario, if it is determined based on the first message that the first intended service area entered by the terminal device does not belong to the intended service area associated with the MBS service, the transceiver module 802 is further configured to: send a fourth message, wherein the fourth message is used to indicate that the terminal device is refused entry into the MBS service session.

[0241] As another possible implementation in this scenario, the transceiver module 802 is further configured to: send a fifth message, wherein the fifth message is used to indicate the MBS service corresponding to the first intended service area, or the intended service area associated with the MBS service.

[0242] As another example of a scenario, in the multicast service of MBS, the first message is used to indicate the second intended service area that the terminal device will leave.

[0243] In one possible implementation, the second intended service area includes N intended service areas associated with the MBS service, and the processing module 801 is specifically used to: remove the terminal device from the MBS service session based on the first message.

[0244] In another possible implementation, the processing module 801 is specifically used to: when it is determined based on the first message and the second message that the third intended service area belongs to the intended service area associated with the MBS service, update the binding relationship between the terminal device and the second intended service area to the binding relationship between the terminal device and the third intended service area.

[0245] In another possible implementation, the processing module 801 is specifically used to: remove the terminal device from the MBS service session if it is determined based on the first message and the second message that the third intended service area does not belong to the intended service area associated with the MBS service.

[0246] As one possible implementation, the transceiver module 802 is also used to send a sixth message, wherein the sixth message is used to indicate the MBS service corresponding to the third intended service area.

[0247] As one possible implementation, the MBS service of the terminal device includes MBS services related to the intended service area of ​​the terminal.

[0248] Reusing Figure 8, in some other embodiments of this application, for example, the communication device 80 shown in Figure 8 can be a terminal device in an NTN system or a component of that terminal device. The processing module 801 and the transceiver module 802 in the communication device can respectively perform the following operations:

[0249] The processing module 801 is used to generate a first message; the transceiver module 802 is used to send the first message, wherein the first message is used to indicate the multicast broadcast service (MBS) of the terminal device, and the first message is also used to indicate the intended service area of ​​the terminal device.

[0250] For example, the first message includes a first index and a second index, the first index being used to indicate an index related to the MBS service of the terminal device, and the second index being used to indicate the intended service area of ​​the terminal device.

[0251] In one scenario, the transceiver module 802 is used to: send a first message when the terminal device enters the first intended service area, wherein the first message is also used to indicate the first intended service area.

[0252] In another scenario, the transceiver module 802 is used to: send a first message when the terminal device leaves the second intended service area, wherein the first message is also used to indicate the second intended service area, the second intended service area includes N intended service areas associated with the MBS service, or the second intended service area is any one of the N intended service areas associated with the MBS service, where N is a positive integer.

[0253] As an example, the transceiver module 802 is also used to: receive a first request message, and the processing module is specifically used to: generate a first message in response to the first request message, and the transceiver module 802 is used to send the first message.

[0254] In one implementation, the transceiver module 802 is further configured to: send a second message, wherein the second message is used to indicate the third intended service area entered by the terminal device.

[0255] In another implementation, the transceiver module 802 is also used to: receive a sixth message, wherein the sixth message is used to indicate the MBS corresponding to the third intended service area.

[0256] In another implementation, the transceiver module 802 is also used to: receive a third message, wherein the third message is used to indicate that the accepting terminal device has joined the MBS service session.

[0257] In another implementation, the transceiver module 802 is also used to: receive a fourth message, wherein the fourth message is used to indicate that the terminal device is rejected from joining the MBS service session.

[0258] In another implementation, the transceiver module 802 is further configured to: receive a fifth message, wherein the fifth message is used to indicate the MBS service corresponding to the first intended service area, or the intended service area associated with the MBS service.

[0259] As one possible implementation, the MBS service of the terminal device includes MBS services related to the intended service area of ​​the terminal.

[0260] The specific descriptions of the transceiver module and processing module shown in the above embodiments are merely examples. For the specific functions or execution steps of the transceiver module and processing module, please refer to the above method embodiments, which will not be described in detail here.

[0261] The communication device according to the embodiments of this application has been described above. The following describes possible product forms of the communication device. Any product possessing the functions of the communication device described in FIG8 above falls within the protection scope of the embodiments of this application.

[0262] The following description is merely an example and does not limit the product form of the communication device in the embodiments of this application to this.

[0263] In one possible implementation, in the communication device shown in FIG8, the processing module 801 can be one or more processors, and the transceiver module 802 can be a transceiver, or the transceiver module 802 can also be a transmitting module and a receiving module. The transmitting module can be a transmitter, and the receiving module can be a receiver. The transmitting module and the receiving module are integrated into one device, such as a transceiver. In the embodiments of this application, the processor and the transceiver can be coupled, etc., and the connection method of the processor and the transceiver is not limited in the embodiments of this application. In the process of executing the above method, the process of sending information in the above method can be the process of the processor outputting the above information. When outputting the above information, the processor outputs the above information to the transceiver so that the transceiver can transmit it. After the above information is output by the processor, it may need to undergo other processing before reaching the transceiver. Similarly, the process of receiving information in the above method can be the process of the processor receiving the input above information. When the processor receives the input information, the transceiver receives the above information and inputs it into the processor. In addition, after the transceiver receives the above information, the above information may need to undergo other processing before being input into the processor.

[0264] As shown in Figure 9, the communication device 90 includes one or more processors 920 and transceivers 910. Exemplarily, the transceiver 910 executes the functions or steps implemented by the transceiver module 802 shown in Figure 8, and the processor 920 executes the functions or steps implemented by the processing module 801 shown in Figure 8. The transceiver 910 may have its own processing logic or may execute related operations under the control of the processor 920. Optionally, the communication device 90 may also include a memory 930, which can store computer programs. The processor 920 performs operations by calling the computer programs in the memory 930, such as generating a first registration request, generating a first inventory response, etc. Specific descriptions of the processor 920 and transceiver 910 can be found in Figure 8 or the method embodiments shown above, and will not be detailed here. Descriptions of related steps and information in the above embodiments can be found in the descriptions in the above method embodiments, and will not be detailed here. In various implementations of the communication device shown in Figure 9, the transceiver may include a receiver for performing a receiving function (or operation) and a transmitter for performing a transmitting function (or operation). The transceiver is also used to communicate with other devices / appliances via a transmission medium.

[0265] This application also provides a chip system, which includes at least one processor for implementing the functions involved in the methods executed by the communication node, access network device, or core network device in any of the above embodiments.

[0266] In one possible design, the chip system further includes a memory for storing program instructions and data, which may be located within or outside the processor.

[0267] The chip system can consist of chips or include chips and other discrete components.

[0268] Optionally, the chip system may contain one or more processors. These processors can be implemented in hardware or software. When implemented in hardware, the processor can be a logic circuit, an integrated circuit, etc. When implemented in software, the processor can be a general-purpose processor, implemented by reading software code stored in memory.

[0269] Optionally, the chip system may contain one or more memories. The memory may be integrated with the processor or disposed separately from it; this application embodiment does not limit this. For example, the memory may be a non-transient processor, such as a read-only memory (ROM), which may be integrated with the processor on the same chip or disposed separately on different chips. This application embodiment does not specifically limit the type of memory or the arrangement of the memory and processor.

[0270] For example, the chip system may be a field programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a system-on-chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a micro controller unit (MCU), a programmable logic device (PLD), or other integrated chips.

[0271] This application also provides a computer program product, which includes a computer program (also referred to as code or instructions) that, when run, causes a computer to execute the method performed by the communication node, access network device, or core network device in any of the above embodiments.

[0272] This application also provides a computer-readable storage medium storing a computer program (also referred to as code or instructions). When the computer program is run, it causes a computer to perform the method executed by the communication node, access network device, or core network device in any of the above embodiments.

[0273] The various embodiments of this application can be combined arbitrarily to achieve different technical effects.

[0274] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk).

[0275] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM or random access memory (RAM), magnetic disks, or optical disks.

[0276] In summary, the above description is merely an embodiment of the technical solution of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made based on the disclosure of this application should be included within the scope of protection of this application.

[0277] The various embodiments of this application can be combined arbitrarily to achieve different technical effects.

[0278] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk).

[0279] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM or random access memory (RAM), magnetic disks, or optical disks.

[0280] In summary, the above description is merely an embodiment of the technical solution of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made according to the disclosure of the present invention should be included within the scope of protection of the present invention.

Claims

1. A communication method characterized by comprising: The method is applied to network devices in non-terrestrial network (NTN) communication, and the method includes: Receive a first message, wherein the first message is used to indicate the multicast broadcast service (MBS) of the terminal device, and the first message is also used to indicate the intended service area of ​​the terminal device.

2. The method of claim 1, wherein, The intended service area of ​​the terminal device includes the first intended service area where the terminal device is located, and / or, The intended service area of ​​the terminal device includes a second intended service area that the terminal device leaves. The second intended service area includes N intended service areas associated with the MBS service, or the second intended service area is any one of the N intended service areas associated with the MBS service, where N is a positive integer.

3. The method according to claim 1 or 2, characterized in that, The method further includes: Send a first request message, wherein the first request message is used to indicate permission to send the first message.

4. The method according to any one of claims 1 to 3, characterized in that, The method further includes: If, based on the first message, it is determined that the number of terminal devices in the intended service area associated with the MBS service is one, the data of the MBS service is transmitted in unicast mode.

5. The method according to any one of claims 1 to 4, characterized in that, The method further includes: If, based on the first message, it is determined that the number of terminal devices in the intended service area associated with the MBS service is greater than one, the data of the MBS service is transmitted in broadcast mode.

6. The method according to any one of claims 2 to 5, characterized in that, The method includes: If, based on the first message, it is determined that the first intended service area entered by the terminal device belongs to the intended service area associated with the MBS service, the session of the MBS service is activated.

7. The method according to any one of claims 1 to 6, characterized in that, The method further includes: Receive a second message, wherein the second message is used to indicate the third intended service area that the terminal device has entered.

8. The method according to any one of claims 1 to 7, characterized in that, The method further includes: If, based on the first message, it is determined that the terminal device is the last session to join the MBS service, the MBS service session is released.

9. The method according to claim 7, characterized in that, The method further includes: If, based on the first message and the second message, it is determined that the third intended service area does not belong to the intended service area associated with the MBS service, and it is determined that the terminal device is the last session to join the MBS service, the MBS service session is released.

10. The method according to claim 7, characterized in that, The method further includes: If, based on the first message and the second message, it is determined that the third intended service area belongs to the intended service area associated with the MBS service, the binding relationship between the terminal device and the second intended service area is updated to the binding relationship between the terminal device and the third intended service area.

11. The method according to any one of claims 1 to 3, characterized in that, The method further includes: If, based on the first message, it is determined that the first intended service area entered by the terminal device belongs to the intended service area associated with the MBS service, a third message is sent, wherein the third message is used to indicate acceptance of the terminal device joining the MBS service session.

12. The method according to any one of claims 1 to 3 or 11, characterized in that, The method further includes: If, based on the first message, it is determined that the first intended service area entered by the terminal device does not belong to the intended service area associated with the MBS service, a fourth message is sent, wherein the fourth message is used to indicate that the terminal device's participation in the MBS service session is rejected.

13. The method according to claim 11 or 12, characterized in that, The method further includes: Send a fifth message, wherein the fifth message is used to indicate the MBS service corresponding to the first intended service area, or the intended service area associated with the MBS service.

14. The method according to any one of claims 1 to 3 or 7, characterized in that, The method further includes: Based on the first message, the terminal device is removed from the MBS service session.

15. The method according to claim 7, characterized in that, The method further includes: If, based on the first message and the second message, it is determined that the third intended service area does not belong to the intended service area associated with the MBS service, the terminal device is removed from the MBS service session.

16. The method according to any one of claims 7 to 10 or 14 to 15, characterized in that, The method further includes: Send a sixth message, wherein the sixth message is used to indicate the MBS service corresponding to the third intended service area.

17. The method according to any one of claims 1 to 16, characterized in that, The first message includes a first index and a second index, wherein the first index is used to indicate an index related to the MBS service of the terminal device, and the second index is used to indicate the intended service area of ​​the terminal device.

18. The method according to any one of claims 1 to 17, characterized in that, The MBS service of the terminal device includes MBS services related to the intended service area of ​​the terminal.

19. A communication method, characterized in that, The method is applied to terminal equipment in NTN communication, and the method includes: Send a first message, wherein the first message is used to indicate the Multicast Broadcast Service (MBS) of the terminal device, and the first message is also used to indicate the intended service area of ​​the terminal device.

20. The method according to claim 19, characterized in that, Sending the first message includes: When the terminal device enters the first intended service area, the first message is sent, wherein the first message is also used to indicate the first intended service area.

21. The method according to claim 19 or 20, characterized in that, Sending the first message includes: When the terminal device leaves the second intended service area, the first message is sent, wherein the first message is further used to indicate the second intended service area, the second intended service area includes N intended service areas associated with the MBS service, or the second intended service area is any one of the N intended service areas associated with the MBS service, where N is a positive integer.

22. The method according to any one of claims 19 to 21, characterized in that, The method further includes: Receive a first request message, wherein the first request message is used to indicate permission to send the first message.

23. The method according to claim 21 or 22, characterized in that, The method further includes: Send a second message, wherein the second message is used to indicate the third intended service area that the terminal device enters.

24. The method according to claim 23, characterized in that, The method further includes: Receive a sixth message, wherein the sixth message is used to indicate the MBS service corresponding to the third intended service area.

25. The method according to any one of claims 19 to 24, characterized in that, The method further includes: A third message is received, wherein the third message is used to indicate acceptance of the terminal device joining the MBS service session.

26. The method according to any one of claims 19 to 25, characterized in that, The method further includes: A fourth message is received, wherein the fourth message is used to indicate that the terminal device is denied access to the MBS service session.

27. The method according to claim 25 or 26, characterized in that, The method further includes: Receive a fifth message, wherein the fifth message is used to indicate the MBS service corresponding to the first intended service area, or the intended service area associated with the MBS service.

28. The method according to any one of claims 19 to 27, characterized in that, The first message includes a first index and a second index, wherein the first index is used to indicate an index related to the MBS service of the terminal device, and the second index is used to indicate the intended service area of ​​the terminal device.

29. A communication device, characterized in that, The communication device includes a module for performing the method as described in any one of claims 1 to 18; or a module for performing the method as described in any one of claims 19 to 28.

30. A communication system, characterized in that, Includes the apparatus as described in claim 29.

Images