Communication method and apparatus

Abstract

The present application discloses a communication method and apparatus. The method comprises: a first access network element acquiring first information, the first information indicating an expected service area of a multicast and broadcast service (MBS) corresponding to a non-terrestrial network (NTN); and sending a system information block (SIB) to a terminal device, the SIB comprising the first information. According to the solution, the first information is carried in the SIB to indicate the expected service area, so that the terminal device can clearly determine, on the basis of the SIB, the range for receiving MBS data in the NTN, thereby achieving the reception of the MBS by the terminal device in the NTN.

Description

Communication method and device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of the People's Republic of China on March 29, 2024, with application number 202410383506.9 and application name "A Communication Method and Device", the entire contents of which are incorporated by reference into this application. Technical Field

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

[0004] Multicast and broadcast service (MBS) is a point-to-multipoint service introduced by the 3rd Generation Partnership Project (3GPP) to effectively utilize mobile communication network resources. It provides a point-to-multipoint service in mobile communication networks where one data source sends data to multiple users, enabling network resource sharing and improving resource utilization, especially air interface resources.

[0005] When a terrestrial network (TN) provides MBS, the network may provide the terminal device with the MBS service area in a service announcement.

[0006] It is still unclear how non-terrestrial networks (NTN) will provide MBS. Summary of the Invention

[0007] The embodiments of the present application provide a communication method and apparatus, which can implement MBS provision in NTN.

[0008] In a first aspect, a communication method is provided, which can be executed by a first access network element. Unless otherwise specified, the "first access network element" in this application can refer to the first access network element itself, or a component in the first access network element (for example, a processor, a chip, or a chip system, etc.), or a logical module or software that can implement all or part of the functions of the first access network element. The method includes: obtaining first information, the first information indicating an expected service area of ​​a multicast and broadcast service (MBS) corresponding to a non-terrestrial network (NTN); and sending a system information block (SIB) to a terminal device, wherein the SIB includes the first information.

[0009] The above solution carries the first information indicating the expected service area in the SIB, so that the terminal device can clearly determine the range of receiving MBS data in the NTN based on the SIB, thereby providing MBS for the terminal device in the NTN and enabling the terminal device to receive MBS in the NTN.

[0010] In one possible design, the SIB is one of the following: SIB19, SIB20, SIB21, SIB24, or SIB used to send the first information.

[0011] This design clarifies several possible ways to send the expected service area, enabling terminal devices to obtain the expected service area in the NTN, improving the accuracy of MBS provision for terminal devices in the NTN, and avoiding problems such as terminal devices receiving the wrong MBS or overreceiving MBS in the NTN.

[0012] In the embodiment of the present application, the content of the first information can be expressed in various forms, and several possible designs are listed below:

[0013] In one possible design, the first information includes coordinates of multiple location points, and the expected service area includes a polygonal area determined based on the coordinates of the multiple location points.

[0014] In one possible design, the first information includes the coordinates of a location point and a distance, and the expected service area includes a circular area with the location point as the center and the distance as the radius or diameter.

[0015] In one possible design, the first information includes a proportional coefficient, and the expected service area includes an area determined by multiplying the coverage area of ​​the cell by the proportional coefficient.

[0016] In one possible design, the first information includes location information of multiple areas, and the expected service area includes an intersection area or a union area of ​​the multiple areas.

[0017] It is understood that the above-mentioned design methods can be implemented separately or in combination without limitation. Moreover, the above-mentioned design methods are only examples and are not limited thereto.

[0018] The above-mentioned design methods clarify the specific definition of the expected service area and further improve the accuracy of providing MBS to terminal devices in the NTN.

[0019] In one possible design, the first information may include a correspondence between a frequency selection area identity (FSAI) and an expected service area, where one FSAI corresponds to one or more expected service areas. When one FSAI corresponds to multiple MBSs, the expected service areas corresponding to the multiple MBSs are the same.

[0020] Therefore, by sending the correspondence between FSAI and the expected service area, the expected service area corresponding to the MBS can be efficiently indicated. For example, when multiple MBSs correspond to the same expected service area, the information of the expected service area can be sent only once, reducing signaling overhead.

[0021] In one possible design, the first access network element may receive the first information from the core network element or the second access network element, thereby improving the flexibility of the solution.

[0022] In a second aspect, a communication method is provided. The method can be performed by a terminal device. Unless otherwise specified, the term "terminal device" in this application can refer to the terminal device itself, a component within the terminal device (e.g., a processor, a chip, or a chip system), or a logic module or software that implements all or part of the terminal device's functions. The method includes: receiving a SIB containing first information indicating an expected service area of ​​an MBS corresponding to an NTN; and stopping receiving MBS data after the terminal device moves out of the expected service area.

[0023] In one possible design, the SIB is one of the following: SIB19, SIB20, SIB21, SIB24, or SIB used to send the first information.

[0024] In one possible design, the first information includes a correspondence between the FSAI and the expected service area, where one FSAI corresponds to one or more expected service areas.

[0025] In one possible design, the first information includes coordinates of multiple location points, and the expected service area includes a polygonal area determined based on the coordinates of the multiple location points.

[0026] In one possible design, the first information includes the coordinates of a location point and a distance, and the expected service area includes a circular area with the location point as the center and the distance as the radius or diameter.

[0027] In one possible design, the first information includes a proportional coefficient, and the expected service area includes an area determined by multiplying the coverage area of ​​the cell by the proportional coefficient.

[0028] In one possible design, the first information includes location information of multiple areas, and the expected service area includes an intersection area or a union area of ​​the multiple areas.

[0029] The beneficial effects of the above-mentioned design methods can be found in the beneficial effects of the corresponding designs in the first aspect and will not be repeated here.

[0030] In one possible design, the expected service area indicated by the first information is a first area. The terminal device receives MBS data within the intersection of the first area and a second area. After the terminal device moves out of the intersection of the first area and the second area, the terminal device stops receiving MBS data. The second area is the expected service area of ​​the MBS indicated in the user service description or service announcement received by the terminal device.

[0031] In this way, it can be ensured that when the terminal device obtains different expected service areas through multiple channels, it can still receive MBS data normally in the NTN, thereby improving the reliability of communication.

[0032] In one possible design, the terminal device saves first information and second information, and the second information indicates the service area of ​​the MBS corresponding to the TN; the terminal device receives MBS data at the NTN according to the first information, and / or receives MBS data at the TN according to the second information.

[0033] In this way, it can be ensured that the terminal equipment can normally receive MBS data in both TN and NTN, thereby improving the reliability of communication.

[0034] In a third aspect, a communication method is provided, which can be executed by a core network element. Unless otherwise specified, the "core network element" in this application can refer to the core network element itself, a component in the core network element (e.g., a processor, chip, or chip system), or a logical module or software that can implement all or part of the core network element functions. The method includes: sending a user service description or service announcement to a terminal device; wherein the user service description or service announcement includes third information, and the third information includes at least one cell identifier, and the at least one cell identifier is used to determine the service area of ​​the MBS corresponding to the NTN.

[0035] The above solution carries at least one cell identifier in the user service description or service announcement to indicate the service area, so that the terminal device can clearly determine the range of receiving MBS data in the NTN based on the user service description or service announcement, thereby providing MBS to the terminal device in the NTN and enabling the terminal device to receive MBS in the NTN.

[0036] In one possible design, the core network element is an application function network element.

[0037] In a possible design, the protocol stipulates or the system stipulates the type of at least one cell identifier, for example, it can only be an air interface cell identifier or a mapped cell identifier.

[0038] This design approach can clarify the type of cell identifier in a user service description or service announcement, further improving the accuracy of providing MBS to terminal devices in the NTN.

[0039] In one possible design, the third information also includes indication information, where the indication information indicates the type of at least one cell identifier, including a mapped cell identifier and / or an air interface cell identifier.

[0040] This design approach can clarify the type of cell identifier in the user service description or service announcement through indication information, further improving the accuracy of providing MBS for terminal devices in the NTN.

[0041] In one possible design, the at least one cell identifier is at least one air interface cell identifier. The core network element may also determine at least one air interface cell identifier corresponding to the service area of ​​the MBS corresponding to the NTN based on the correspondence between the mapped cell identifier and the air interface cell identifier.

[0042] This design clarifies the process by which the core network sends the air interface cell identifier in user service descriptions or service announcements, further improving the accuracy of MBS provision for terminal devices in the NTN.

[0043] In a possible design, the core network element may also obtain the correspondence between the mapped cell identifier and the air interface cell identifier from the access network element.

[0044] This design approach enables the core network element to learn the correspondence between the mapped cell identifier and the air interface cell identifier, and provides support for the core network element to send the air interface cell identifier.

[0045] In one possible design, the at least one cell identifier is at least one mapped cell identifier. The third information may also include at least one of the following: an air interface cell identifier corresponding to the at least one mapped cell identifier, and geographic location information corresponding to the at least one mapped cell identifier.

[0046] This design clarifies the process by which the core network sends mapped cell identifiers in user service descriptions or service announcements, further improving the accuracy of MBS provision for terminal devices in the NTN.

[0047] In a fourth aspect, a communication method is provided, which can be executed by a terminal device. Unless otherwise specified, the term "terminal device" in this application can refer to the terminal device itself, a component within the terminal device (e.g., a processor, chip, or chip system), or a logic module or software that implements all or part of the terminal device's functions. The method includes: receiving a user service description or service announcement; wherein the user service description or service announcement includes third information, the third information including at least one cell identifier; and determining a service area for an MBS corresponding to an NTN based on the third information.

[0048] In one possible design, the third information also includes indication information, where the indication information indicates the type of each cell identifier in at least one cell identifier, where the type includes a mapped cell identifier and / or an air interface cell identifier.

[0049] In one possible design, at least one cell identifier is at least one air interface cell identifier.

[0050] In one possible design, the at least one cell identifier is at least one mapped cell identifier;

[0051] In one possible design, an air interface cell identifier corresponding to at least one mapped cell identifier and geographic location information corresponding to at least one mapped cell identifier.

[0052] The technical effects corresponding to the above-mentioned design methods can be found in the technical effects of the corresponding designs of the third party, which will not be repeated here.

[0053] In one possible design, the at least one cell identifier is at least one mapped cell identifier. The terminal device may further receive fourth information from an access network element, where the fourth information includes at least one of the following: a correspondence between a mapped cell identifier and an air interface cell identifier, and a correspondence between a mapped cell identifier and geographic location information; and determine a service area of ​​an MBS corresponding to the NTN based on the third information and the fourth information.

[0054] With this design, the terminal device can obtain the correspondence between the mapped cell identifier and the air interface cell identifier, the correspondence between the mapped cell identifier and the geographic location information, etc. from the access network element, and then determine the service area based on the obtained correspondence and the mapped cell identifier, clarify the scope of receiving MBS data in the NTN, and improve the reliability of providing MBS to the terminal device in the NTN.

[0055] In a fifth aspect, a communication method is provided, which can be executed by an access network element. Unless otherwise specified, the "access network element" in this application can refer to the access network element itself, or a component in the access network element (for example, a processor, a chip, or a chip system, etc.), or a logical module or software that can implement all or part of the functions of the access network element. The method includes: determining fourth information, the fourth information including at least one of the following: a correspondence between a mapped cell identifier and an air interface cell identifier, and a correspondence between a mapped cell identifier and geographic location information; and sending the fourth information.

[0056] In this solution, the access network element provides the terminal device with the correspondence between the mapped cell identifier and the air interface cell identifier, the correspondence between the mapped cell identifier and the geographic location information, etc., so that the terminal device can determine the service area based on these correspondences and the mapped cell identifier, clarify the scope of receiving MBS data in the NTN, and improve the accuracy of providing MBS to the terminal device in the NTN.

[0057] In a sixth aspect, a communication device is provided, comprising a module, a unit or a technical means for executing the method described in the first aspect or any possible design of the first aspect.

[0058] Exemplarily, the device may include:

[0059] a transceiver module, configured to obtain first information indicating an expected service area of ​​an MBS corresponding to a non-terrestrial network;

[0060] The transceiver module is further configured to send an SIB to the terminal device, where the SIB includes the first information;

[0061] Optionally, the device may further include: a processing module, configured to generate a SIB.

[0062] In a seventh aspect, a communication device is provided, comprising a module, a unit or a technical means for executing the method described in the second aspect or any possible design of the second aspect.

[0063] Exemplarily, the device may include:

[0064] a transceiver module, configured to receive a SIB, where the SIB includes first information, where the first information indicates an expected service area of ​​an MBS corresponding to a non-terrestrial network;

[0065] The transceiver module is further configured to: stop receiving MBS data after the terminal device moves out of the expected service area;

[0066] Optionally, the device may further include: a processing module, configured to control the receiving module to receive SIB and stop receiving MBS data.

[0067] In an eighth aspect, a communication device is provided, comprising a module, unit or technical means for executing the method described in the third aspect or any possible design of the third aspect.

[0068] Exemplarily, the device may include:

[0069] The transceiver module is used to send a user service description or service announcement to the terminal device; wherein the user service description or service announcement includes third information, the third information includes at least one cell identifier, and the at least one cell identifier is used to determine the service area of ​​the MBS corresponding to the non-terrestrial network.

[0070] Optionally, the device may further include a processing module configured to generate a user service description or a service announcement.

[0071] In a ninth aspect, a communication device is provided, comprising a module, unit or technical means for executing the method described in the fourth aspect or any possible design of the fourth aspect.

[0072] Exemplarily, the device may include:

[0073] A transceiver module, configured to receive a user service description or a service announcement; wherein the user service description or the service announcement includes third information, and the third information includes at least one cell identifier;

[0074] The processing module is configured to determine a service area of ​​the MBS corresponding to the non-terrestrial network according to the third information.

[0075] In the tenth aspect, a communication device is provided, comprising a module, unit or technical means for executing the method described in the fifth aspect.

[0076] Exemplarily, the device may include:

[0077] a processing module, configured to determine fourth information, the fourth information including at least one of the following: a correspondence between a mapped cell identifier and an air interface cell identifier, and a correspondence between a mapped cell identifier and geographic location information;

[0078] The transceiver module is used to send fourth information.

[0079] In the eleventh aspect, a communication device is provided, comprising: a processor, the processor being coupled to a memory, the memory being used to store programs or instructions, and when the program or instructions are executed by the processor, the communication device is caused to execute the method described in the first aspect or any possible design of the first aspect, or the communication device is caused to execute the method described in the second aspect or any possible design of the second aspect, or the communication device is caused to execute the method described in the third aspect or any possible design of the third aspect, or the communication device is caused to execute the method described in the fourth aspect or any possible design of the fourth aspect, or the communication device is caused to execute the method described in the fifth aspect.

[0080] In the twelfth aspect, a computer-readable storage medium is provided, wherein the storage medium stores a computer program or instructions. When the computer program or instructions are executed by a communication device, the method described in the first aspect or any possible design of the first aspect is implemented, or the method described in the second aspect or any possible design of the second aspect is implemented, or the method described in the third aspect or any possible design of the third aspect is implemented, or the method described in the fourth aspect or any possible design of the fourth aspect is implemented, or the method described in the fifth aspect is implemented.

[0081] In the thirteenth aspect, a computer program product is provided, which includes a computer program or instructions. When the computer program or the instructions are run by a communication device, the method described in the first aspect or any possible design of the first aspect is executed, or the method described in the second aspect or any possible design of the second aspect is executed, or the method described in the third aspect or any possible design of the third aspect is executed, or the method described in the fourth aspect or any possible design of the fourth aspect is executed, or the method described in the fifth aspect is executed.

[0082] In the fourteenth aspect, a communication device is provided, which includes a processor and an interface circuit, wherein the interface circuit is electrically coupled to the processor, and the processor causes the method described in the first aspect or any possible design of the first aspect to be executed through a logic circuit or execution code instructions, or causes the method described in the second aspect or any possible design of the second aspect to be executed, or causes the method described in the third aspect or any possible design of the third aspect to be executed, or causes the method described in the fourth aspect or any possible design of the fourth aspect to be executed, or causes the method described in the fifth aspect to be executed.

[0083] According to a fifteenth aspect, a communication system is provided, including:

[0084] A first access network element, configured to perform the method as described in the first aspect or any possible design of the first aspect;

[0085] A terminal device is used to execute the method described in the second aspect or any possible design of the second aspect.

[0086] In a sixteenth aspect, a communication system is provided, including:

[0087] A core network element, configured to execute the method as described in the third aspect or any possible design of the third aspect;

[0088] A terminal device, used to execute the method as described in the fourth aspect or any possible design of the fourth aspect.

[0089] Optionally, the system also includes an access network element, which is used to execute the method described in the fifth aspect.

[0090] The specific designs and beneficial effects of the sixth to sixteenth aspects mentioned above can be found in the specific designs and beneficial effects of the first to fifth aspects, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0091] FIG1 is a schematic diagram of an MBS transmission method;

[0092] FIG2 is a schematic diagram of an NTN network;

[0093] FIG3 is a flowchart of establishing a broadcast MBS session;

[0094] FIG4 is a schematic diagram of a communication system applicable to an embodiment of the present application;

[0095] FIG5 is a flow chart of a communication method provided by the present application;

[0096] FIG6 is a flow chart of another communication method provided by the present application;

[0097] 7A to 7D are flowcharts of several communication methods provided in this application;

[0098] FIG8 is a schematic diagram of a communication device provided in an embodiment of the present application;

[0099] FIG9 is a schematic diagram of another communication device provided in an embodiment of the present application;

[0100] FIG10 is a schematic diagram of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0101] Below, some terms used in the embodiments of the present application are explained to facilitate understanding by those skilled in the art.

[0102] 1) Multicast and broadcast service (MBS): MBS is a service that is transmitted simultaneously to multiple terminal devices, such as live broadcast services, public safety services, and batch software updates. MBS originates from a data server. First, the data server sends the MBS data to the core network device. The core network device then sends the MBS data to the access network device. Finally, the access network device sends the MBS data to at least one terminal device that receives the MBS. When the core network device sends MBS data to the access network device, the MBS data is transmitted over a common transmission channel, known as an MBS session. When the access network device sends MBS data to the terminal device, there are two transmission methods: point-to-multipoint (PTM) transmission or point-to-point (PTP) transmission. Figure 1 shows a schematic diagram of PTP and PTM.

[0103] It should be noted that MBS is only an exemplary name. The naming of multicast broadcast services may be different under different communication standards. For example, in long term evolution (LTE), multicast broadcast services can be called multimedia broadcast multicast services (MBMS), and in new radio (NR), multicast broadcast services can be called MBS. In future communication development, multicast broadcast services may also be named other names, and this application does not make specific limitations.

[0104] In the embodiment of the present application, MBS may also be referred to as "MBS service", "MBS business", "MBS broadcast service", "MBS session", "MBS broadcast service" and the like.

[0105] The area where MBS is provided may be referred to as "MBS service area", "MBS business area", "MBS broadcast service area", "MBS session area", "MBS broadcast service area", "MBS area" or "multicast service area (MBS service area)" or "MBS service area" or "service area", etc.

[0106] MBS service types include multicast service (also known as multicast service) and broadcast service. In this application, MBS can be replaced by multicast or broadcast.

[0107] 2) Multicast service:

[0108] It is designed for services with high quality of service (QoS) requirements. It requires group management for multicast services and can provide the same QoS level as unicast services. Specifically, for multicast services, the core network (CN) needs to manage the joining and exit of terminal devices. For the radio access network (RAN), it supports PTP and PTM transmission methods to send data to terminal devices, and supports dynamic switching between PTP and PTM controlled by the RAN. Multicast services are provided to terminal devices in the radio resource control (RRC) connected state, and the RAN and CN are required to maintain the terminal device information corresponding to the MBS group. At the same time, for multicast services, it also supports MBS session deactivation / activation triggered by the core network, and the terminal device is not aware of the service status.

[0109] 3) Broadcasting business:

[0110] The broadcast service is designed for services with relatively low QoS requirements and is a best-effort QoS guarantee. The broadcast service supports terminal devices in any RRC state. The RAN and CN do not need to maintain a group of terminal devices that receive related broadcast services. When a service is being provided, the terminal device group receives it autonomously according to the configuration information. The data transmission of the broadcast service is designed only for downlink transmission, just like the multicast service. The difference from the multicast service is that the broadcast service only supports the PTM transmission mode. For terminal devices, the configuration of the broadcast service and the configuration of the multicast service are completely independent. For the broadcast service, it is mandatory to provide services within a certain range. Optionally, different data content can be provided in different areas for a service (i.e., local broadcast service).

[0111] 4) Local MBS: Local MBS service features service content that is area-dependent. Specifically, it is divided into two categories: area-limited MBS service or local MBS service, and location-dependent MBS service. Accordingly, the MBS service area (hereinafter referred to as the service area) consists of a set of tracking areas (TAs) and / or a set of cells, which are used to indicate a specific range.

[0112] For a local MBS service, only UEs within the MBS service area may receive content data, while UEs outside the MBS service area are not allowed to receive location-specific content.

[0113] For location-specific multicast services, an MBS is associated with multiple service areas, each identified by an area session ID. Different area session IDs within the same area session may contain different data content and possibly from different sources. Terminal devices are unaware of the area session ID, only the MBS session identifier, such as the MBS Session ID or temporary mobile group identity (TMGI). The base station controls the sending of different multicast data to different terminal devices within different areas.

[0114] 5) Non-terrestrial networks (NTN) and terrestrial networks (TN):

[0115] A non-terrestrial network, or NTN or NTN network for short, refers to a network in which at least some network equipment is deployed on land other than land. For example, this includes aircraft (such as airplanes or drones) or satellites used as relay nodes or base stations in a communication system, as shown in Figure 2. Conversely, a terrestrial network, or TN or TN network for short, is a network in which all network equipment is deployed on land.

[0116] Compared to TN, NTN boasts larger coverage areas and more flexible networking. For example, in NTN, since satellites are involved in the communication process, data sent between a terminal device and a base station must be transmitted to the satellite. Due to the long transmission distance, this creates significant propagation delays, resulting in round-trip times (RTTs) of tens to hundreds of milliseconds. This compares to the RTTs of traditional terrestrial communication networks, which are several milliseconds or less. Because network signals are transmitted by satellites, the distance from the satellite to the ground is significant, resulting in a much larger coverage radius for the proposed NTN air interface cell than for the TN air interface cell.

[0117] 6) Uu cell ID, mapped cell ID:

[0118] Air interface cell identification, that is, the identification of the air interface cell. In TN, the air interface cell identification includes the physical cell identification (PCI) and / or carrier frequency (such as the absolute radio frequency channel number (ARFCN) value), etc. The cell corresponding to the air interface cell identification also corresponds to a unique global cell identification code (GCI). For the core network, CGI is the most commonly used identifier to identify the cell. In some scenarios, some core network elements (such as the network exposure function (NEF), AMF, etc.) can map a specific geographical location based on CGI.

[0119] However, in NTNs, the coverage radius of air-interface cells is excessively large. Some NTN satellites are not geostationary but rather mobile. Therefore, air-interface cells in NTNs may be mobile (i.e., earth-moving), and the actual geographical area covered by a cell may vary. If a cell is still identified using a CGI or PCI, the core network cannot map it to a specific geographical area. Therefore, NTN research requires further enhancement of the cell concept. For example, the concept of a mapped cell ID has been introduced for cell identification. An NTN air-interface cell may be associated with multiple mapped cell IDs, each corresponding to a fixed geographical area. For the NG interface (the interface between the core network and base stations), all exchanged cell IDs should use the mapped cell ID to populate the NR CGI field, ensuring that both the base station and the core network can clearly identify the geographical location to which the exchanged cell ID corresponds. For the Xn interface (the interface between base stations), either the mapped cell ID or the air-interface cell ID can be exchanged.

[0120] It can be understood that the purpose of mapping the cell identifier is to map the geographical location area, and does not represent the air interface cell coverage of the geographical location area, nor does it mean that the geographical location area must have signal coverage.

[0121] 7) In the embodiments of the present application, "at least one" refers to one or more, and "more" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0122] Furthermore, unless otherwise indicated, ordinal numbers such as "first" and "second" in the embodiments of this application are used to distinguish between multiple objects and are not used to limit the size, content, order, timing, priority, or importance of the multiple objects. For example, the first threshold and the second threshold are only used to distinguish different thresholds and do not indicate a difference in size, priority, or importance between the two thresholds.

[0123] The foregoing text introduces some of the terms and concepts involved in the embodiments of this application. The following text introduces the technical features involved in the embodiments of this application.

[0124] When the TN provides MBS, the network may provide the terminal device with MBS service area information (hereinafter referred to as MBS service area or service area) in the service announcement to indicate the MBS service area. For example, referring to FIG3 , a flowchart for establishing a broadcast service MBS session (hereinafter referred to as a broadcast MBS session) includes the following steps:

[0125] S301: CN allocates TMGI for identifying broadcast services and establishes an MBS session. During this process, the application function (AF) may send information to the terminal device through a service announcement (SA), and the information may include the MBS service area.

[0126] Specifically, for local MBS services, the service announcement may include MBS service area information, such as a cell identity (ID) list, a tracking area identity (TAI) list, geographic area information or city address information, etc. The cell ID list and TAI list can only be used by the AF located in the trust domain.

[0127] It can be understood that the service announcement can be included in the user service description (USD), which is the information configured at the application layer.

[0128] In addition to MBS service area information, the service announcement may also include a frequency selection area identity (FSAI). The FSAI is used to guide terminal devices in frequency selection for broadcast MBS sessions, increasing the probability of terminal devices reselecting to a cell delivering the desired broadcast service. The same FSAI can be assigned to one or more broadcast MBS sessions.

[0129] The mapping between broadcast MBS sessions and FSAI is communicated to the terminal device in the service announcement. The UE compares these FSAI with the FSAI in the system message for frequency selection during cell reselection.

[0130] For example, the service announcement may include TMGI and frequency selection area identity (FSAI). Optionally, it may also include frequency. The system information block (SIB) 21 may include the correspondence between FSAI and frequency. The terminal device can determine the TMGI of the broadcast service it wants to receive and the FSAI corresponding to the TMGI based on the received USD. If the FSAI corresponding to the TMGI is in the SIB21 of the service cell of the terminal device, the frequency corresponding to the FSAI in SIB21 can be set to the highest priority, thereby increasing the probability of the terminal device retransmitting to the cell corresponding to the frequency providing the MBS service.

[0131] S302: The multicast / broadcast-session management function (MB-SMF) can use the network function repository function (NRF) to discover the access and mobility management function (AMF) that supports MBS according to the MBS service area and select the appropriate AMF. If the service type is a broadcast service, the MB-SMF sends an MBS session resource establishment request message, such as an MBS broadcast service context generation request (Namf_MBSBroadcast_ContextCreate Request), to the selected AMF in parallel. The request may include TMGI, 5G QoS profile, MBS service area, etc. The MB-SMF may also include the maximum response time in the request.

[0132] S303: The AMF forwards the MBS session resource establishment request message to all next generation radio access network nodes (NG-RAN) that support MBS in the MBS service area, for example, sending an N2 message request (N2 message Request) to the NG-RAN. The request may include 5G QoS Profile, MBS service area, etc.

[0133] S304: NG-RAN creates an MBS session context and stores the TMGI and 5G QoS Profile in the MBS session context.

[0134] S305a: If the NG-RAN prefers to use N3mb multicast transmission (and if there is an available multicast transmission tunnel address on the NG-RAN side), the NG-RAN joins the multicast group (i.e., joins the IP multicast group).

[0135] S305b: If the NG-RAN prefers to use N3mb unicast transmission between the NG-RAN and the MB-UPF (or if there is no multicast transmission tunnel address in the NG-RAN), the NG-RAN allocates an N3mb tunnel endpoint for receiving the downlink MBS session data.

[0136] S306: When the NG-RAN successfully establishes the corresponding MBS session in at least one cell, it sends an MBS Session Resource Setup Response message, such as an N2 message response, to the AMF to report the successful establishment of the MBS session resources. If the NG-RAN fails to establish the MBS session in all cells, it responds with a setup failure.

[0137] S307: AMF sends an MBS session resource establishment response message to MB-SMF, for example, sends an MBS broadcast service context creation response (Namf_MBSBroadcast_ContextCreate Response).

[0138] When the AMF receives the first successful response from the NG-RAN(s), it shall respond with a success response. If all NG-RANs report failure, the AMF shall respond with a failure response. The MB-SMF stores the AMF that responded successfully in the MBS session context as a downstream node. If the AMF receives NG-RAN responses from all involved NG-RAN(s), the AMF shall also include an indication that all NG-RANs have completed the operation.

[0139] S308: NG-RAN sends the configuration information of the broadcast service in the MCCH (MBS control channel, MCCH) message.

[0140] S309: The terminal device receives data of the broadcast service based on the configuration information.

[0141] It is understood that the above steps are merely examples, and may include more steps or only some of them. Figure 1 uses the broadcast service as an example. The existing MBS session establishment process for multicast services can refer to the MBS session establishment process for broadcast services, and the differences will not be further described.

[0142] In NTN research, enabling NTN to support MBS scenarios is mentioned, but the solution for providing MBS in NTN is still unclear.

[0143] In view of this, a technical solution of an embodiment of the present application is provided. The embodiment of the present application can be applied to various communication systems, for example, it can be the Internet of Things (IoT), narrowband Internet of Things (NB-IoT), LTE, or a fifth generation (5G) communication system, or a hybrid architecture of LTE and 5G, or a new communication system that will emerge in the development of 6G or future communications, etc. The 5G communication system described in the present application may include at least one of a non-standalone (NSA) 5G communication system and a standalone (SA) 5G communication system. The communication system may also be a machine to machine (M2M) network, a machine type communication (MTC) or other network.

[0144] As shown in Figure 4, a schematic diagram of a communication system applicable to an embodiment of the present application is shown. The communication system includes a radio access network (RAN) 100 and a core network (CN) 200. Optionally, the Internet 300 may also be included.

[0145] RAN 100 includes at least one RAN node (e.g., 110a and 110b in FIG. 4 , collectively referred to as 110) and at least one terminal device (e.g., 120a-120j in FIG. 4 , collectively referred to as 120). The RAN may also include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in FIG. 4 ). Terminal device 120 is wirelessly connected to RAN node 110. RAN node 110 is wirelessly or wiredly connected to core network 200. The core network devices in core network 200 and RAN node 110 in RAN 100 may be separate physical devices, or they may be a single physical device that integrates core network logical functions and radio access network logical functions.

[0146] The RAN 100 may be a cellular system related to the Third Generation Partnership Project (3GPP), such as a 4G or 5G mobile communication system, an NTN system, or a future-oriented evolution system (such as a 6G mobile communication system). The RAN 100 may also be an open access network (O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) system, or a communication system that integrates two or more of the above systems.

[0147] In the embodiment of the present application, the RAN 100 may be an NTN system, the RAN 100 may be in a transparent transmission mode or a regeneration mode, and the serving cell of the RAN 100 may be a fixed cell or an earth fixed cell or an earth moving cell.

[0148] The terminal device 120 may also be referred to as a terminal, user equipment (UE), mobile station, mobile terminal, etc. The terminal device can be widely used in various scenarios, for example, device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IOT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city, etc. The terminal can be a mobile phone, a tablet computer, a computer with wireless transceiver function, a wearable device, a vehicle, a drone, a helicopter, an airplane, a ship, a robot, a robotic arm, a smart home device, etc. The embodiments of the present application do not limit the device form of the terminal.

[0149] RAN node 110, sometimes also referred to as access network equipment, access network element, RAN entity, or access node, constitutes part of a communication system and facilitates wireless access for terminals. Multiple RAN nodes 110 in a communication system can be of the same type or different types. In some scenarios, the roles of RAN node 110 and terminal 120 are relative. For example, network element 120i in Figure 4 can be a helicopter or drone, which can be configured as a mobile base station. For terminal 120j accessing RAN 100 via network element 120i, network element 120i is a base station; however, for base station 110a, network element 120i is a terminal. RAN node 110 and terminal 120 are sometimes referred to as communication devices. For example, network elements 110a and 110b in Figure 4 can be understood as communication devices with base station functionality, and network elements 120a-120j can be understood as communication devices with terminal functionality.

[0150] In one possible scenario, a RAN node may be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a next-generation base station in a sixth-generation (6G) mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system. A RAN node may be a macro base station (such as 110a in Figure 4 ), a micro base station or an indoor station (such as 110b in Figure 4 ), a relay node or a donor node, or a wireless controller in a CRAN scenario. Alternatively, a RAN node may be a server, a wearable device, a vehicle, or an onboard device. For example, the access network device in vehicle-to-everything (V2X) technology may be a roadside unit (RSU).

[0151] In another possible scenario, multiple RAN nodes collaborate to assist terminals in achieving wireless access, with different RAN nodes implementing portions of the base station's functionality. For example, a RAN node can be a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU). The CU and DU can be separate or included in the same network element, such as the baseband unit (BBU). The CU and DU nodes split the gNB's protocol layers, centrally controlling some protocol layer functions within the CU and distributing some or all of the remaining protocol layer functions within the DU, which is then centrally controlled by the CU. As an implementation method, the CU is deployed with the radio resource control (RRC) layer, the PDCP layer, and the service data adaptation protocol (SDAP) layer in the protocol stack; the DU is deployed with the radio link control (RLC) layer, the media access control (MAC) layer, and the physical layer (PHY) in the protocol stack. Thus, the CU has the processing capabilities of RRC, PDCP, and SDAP. The DU has the processing capabilities of RLC, MAC, and PHY. It will be understood that the above functional division is only an example and does not constitute a limitation on the CU and DU. The RU may be included in a radio frequency device or a radio frequency unit, for example, in a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH).

[0152] The communication between the access network device and the terminal device follows a certain protocol layer structure. The protocol layer may include a control plane protocol layer and a user plane protocol layer. The control plane protocol layer may include at least one of the following: a radio resource control (RRC) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, a media access control (MAC) layer, or a physical (PHY) layer. The user plane protocol layer may include at least one of the following: a service data adaptation protocol (SDAP) layer, a PDCP layer, an RLC layer, a MAC layer, or a physical layer.

[0153] Core network equipment refers to the equipment in the core network that provides service support for terminals. Some examples of core network equipment include access and mobility management function (AMF) entity, session management function (SMF) entity, user plane function (UPF) entity, application function (AF) entity, etc., which are not listed here one by one.

[0154] The AMF entity can be responsible for terminal access management and mobility management, such as user location updates, user network registration, and user handover. The SMF entity can be responsible for session management, such as session establishment, modification, and release. Specific functions include allocating IP addresses to users and selecting the UPF that provides message forwarding capabilities. The UPF entity can be a functional entity in the user plane, primarily responsible for connecting to external networks and processing user messages, such as forwarding and billing. The AF is primarily responsible for providing services to the 3GPP network.

[0155] It should be noted that the entity in this application may also be referred to as a network element or a functional entity. For example, the AMF entity may also be referred to as an AMF network element or an AMF functional entity. For example, the SMF entity may also be referred to as an SMF network element or an SMF functional entity. In this document, any entity / network element may also be represented by its English abbreviation. For example, AF may represent an application function network element.

[0156] It is understood that the network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. It is known to those skilled in the art that with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems. For example, the boundaries and definitions of access network equipment and core network equipment may vary, such as merging part of the core network's functions into the base station side, or merging part of the access network's functions into the core network, or merging the core network and the access network into the core network (which can be called network equipment), or completely splitting the existing core network and access network's functions into different functions (all performed by different network equipment), and so on.

[0157] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0158] See Figure 5, which is a flow chart of a communication method provided by this application, which can be applied to NTN. The method includes S501 to S503:

[0159] S501: An access network element obtains first information.

[0160] The first information indicates the expected service area of ​​the MBS corresponding to the NTN.

[0161] The intended service area (e.g., intended service area) refers to the area where NTN provides MBS. Terminal devices receive MBS data within the intended service area, and stop or do not receive MBS data after moving out of the intended service area. It can be understood that when a terminal device receives MBS data within the intended service area, it means that the terminal device has enabled the function of receiving MBS data within the intended service area, and whether the terminal device actually receives the MBS data depends on whether the network currently sends MBS data. If so, the terminal device will receive the MBS data. When a terminal device stops or does not receive MBS data after moving out of the intended service area, it means that the terminal device disables the function of receiving MBS data outside the intended service area, and does not receive MBS data regardless of whether the network currently sends MBS data.

[0162] It should be noted that the expected service area is only an exemplary name for the service area where NTN provides MBS. In actual applications, the expected service area may also be named otherwise, for example, a specific service area, an additional service area, an additional service area, an NTN-specific service area, a redundant service area, or a precise service area, etc. This application does not impose any restrictions.

[0163] Optionally, the first information can also be called expected service area information, specific service area information, additional service area information, additional service area information, NTN-specific service area information, redundant service area information or precise service area information, etc. This application does not limit the name of the first information.

[0164] The content of the first information can be expressed in various forms, some of which are listed below:

[0165] Example 1: The first information includes (or is) the coordinates of multiple location points. Accordingly, the expected service area includes a polygonal area determined based on the coordinates of the multiple location points. For example, the first information includes the latitude and longitude information of four location points, and the expected service area is the quadrilateral area enclosed by the lines connecting the four location points.

[0166] Example 2: The first information includes (or is) the coordinates of a location point and a distance, and the expected service area includes a circular area with the location point as the center and the distance as the radius or diameter.

[0167] Example 3: The first information includes (or is) a proportional coefficient, and the expected service area includes the area determined by multiplying the coverage area of ​​the cell by the proportional coefficient. The proportional coefficient can be a proportional coefficient of the diameter or radius of the cell (such as 1 / 2 of the cell radius). The cell can be an air interface cell or a mapped cell. Optionally, the first information also includes a cell identifier. Alternatively, the cell identifier and the first information are carried in different signaling.

[0168] Example 4: The first information includes (or is) the location information of multiple areas, and the expected service area includes the intersection area or the union area of ​​the multiple areas. The implementation method of the location information of each area can refer to the above Example 1, Example 2, or Example 3 without limitation. For example, the first information includes multiple combinations of [circle center + distance], and the expected service area is the intersection area of ​​multiple circles determined by the multiple [circle center + distance].

[0169] The examples above clarify the specific definition of the expected service area, which can improve the accuracy of MBS provision for terminal devices in the NTN. Of course, the above examples are only examples, and there are other possibilities.

[0170] In one possible implementation, the access network element may obtain the first information from a core network element, such as from an AMF or SMF. The AMF or SMF may obtain the first information from the AF and then send the first information to the access network element. In another possible implementation, the access network element may obtain the first information from another access network element. For example, if the access network element in S501 is the first access network element, the first access network element may obtain the first information from a second access network element. The second access network element may obtain the first information from another access network element or from a core network element.

[0171] S502: The access network element sends the SIB, and the terminal device receives the SIB.

[0172] The SIB includes first information.

[0173] In one possible implementation, the SIB is a SIB used to send the first information. Alternatively, the SIB may be a newly defined SIB specifically used to indicate the expected service area. For example, the SIB is SIBx, where the value of x can be set as required.

[0174] In another possible implementation, the SIB may reuse an existing SIB, for example, the SIB is any one of SIB19, SIB20, SIB21, SIB24, etc. Among them, SIB19 contains satellite assistance information for NTN access; SIB20 contains the information required to acquire the MCCH / MTCH configuration for MBS broadcast; SIB21 contains the mapping between the current and / or neighbouring carrier frequencies and MBS Frequency Selection Area Identities (FSAI); SIB24 contains the information required to acquire the multicast MCCH / MTCH configuration for MBS multicast reception in RRC_INACTIVE. This implementation method can save signaling by reusing existing SIBs.

[0175] Both of the above implementation methods clarify the specific sending method of the expected service area, and can enable the terminal device to obtain the expected service area in the NTN through the SIB, thereby improving the accuracy of providing MBS to the terminal device in the NTN and avoiding problems such as the terminal device receiving the wrong MBS or over-receiving MBS in the NTN.

[0176] In one possible scenario, the SIB is SIB19, and the access network element is a deployment scenario where the CU and DU are separated. SIB19 is generated by the DU. Therefore, after the CU obtains the first information from the core network element, it sends the first information to the DU, which then carries the first information in SIB19 and sends it to the terminal device. Similarly, if other SIBs, such as SIBx, are also generated by the DU, the same interaction process between the CU and DU is also required.

[0177] In one possible design, the first information in the SIB may include a correspondence between the FSAI and the expected service area, where one FSAI corresponds to one or more expected service areas; or the SIB includes a correspondence between the FSAI and the expected service area, where the expected service area is the first information. The access network element may obtain the correspondence between the FSAI and the expected service area from the core network element, for example, by carrying the correspondence in a broadcast session establishment request sent by the core network element to the access network element; or, the access network element may obtain the correspondence between the FSAI and the expected service area from other access network elements, without limitation.

[0178] Exemplarily, when SIB21 carries the first information, in addition to carrying the correspondence between FSAI and frequency, SIB21 also carries the correspondence between FSAI and expected service area. For example, SIB21 carries frequency f1 and FSAI1 and FSAI 2 corresponding to f1, as well as information about the expected service area corresponding to FSAI1 and information about the expected service area corresponding to FSAI2. The content of the expected service area information can refer to Examples 1 to 4 above.

[0179] It is understood that when the same FSAI corresponds to multiple MBSs, the expected service areas corresponding to these multiple MBSs are the same. Therefore, by sending the correspondence between the FSAI and the expected service area, the expected service area corresponding to the MBS can be efficiently indicated. For example, when multiple MBSs correspond to the same expected service area, the expected service area information can be sent only once, avoiding repeated transmission of the same expected service area information. This can significantly reduce information overhead, especially when the amount of expected service area information is large.

[0180] It is understandable that the first information at different stages (for example, the first information received by the access network element from the core network element and the first information sent by the access network element to the terminal device) may have the same or different names, or may contain the same or different content. For example, the first information obtained by the access network element from the core network element is the coordinates of multiple location points, and the first information carried by the access network element in SIB21 is the correspondence between the FSAI and the expected service area; for example, the first information obtained by the access network element from the core network element and the first information carried in SIB21 are both the correspondence between the FSAI and the expected service area.

[0181] The expected service area in the embodiment of the present application can be at the MBS session granularity (or TMGI granularity), that is, different MBS sessions (or MBSs) correspond to different expected service areas; it can also be at the service area (area session) granularity of the MBS session, that is, for location dependent MBS sessions, different area sessions correspond to different expected service areas; it can also be at the FSAI granularity, that is, different FSAIs correspond to different expected service areas; it can also be at the cell granularity, that is, all MBSs in this cell can only be received by the terminal device in a certain area of ​​the cell; it can also be at the PLMN granularity, that is, different PLMNs correspond to different expected service areas, etc., and the embodiment of the present application does not impose any restrictions.

[0182] In one possible design, the first information can be transparent to the access network element, or in other words, the access network element can transparently transmit the first information. For example, after obtaining the first information, the access network element may not understand which expected service areas the first information specifically indicates, and may directly send the first information to the terminal device by carrying it in the SIB. This can reduce the complexity of the access network element side.

[0183] S503: After moving out of the expected service area, the terminal device stops receiving MBS data.

[0184] Specifically, after receiving the first information, the terminal device can learn the expected service area. When the terminal device is in the expected service area, the terminal device can receive MBS data. When the terminal device moves out of the expected service area, it stops or does not receive MBS data.

[0185] Optionally, for a scenario where an inactive terminal device receives MBS, the terminal device may trigger an RRC connection resume process after moving outside the expected service area to enter a connected state.

[0186] The above solution carries first information indicating the expected service area in the SIB, allowing the terminal device to clearly define the range of MBS data to be received in the NTN based on the SIB, thereby providing MBS to the terminal device in the NTN and enabling the terminal device to receive MBS in the NTN. It also provides a specific definition of the expected service area (such as Examples 1 to 4) and a specific method for transmitting the expected service area (for example, indicating the expected service area in SIB19, SIB20, SIB21, SIB24, or SIBx), further improving the accuracy of MBS provision for terminal devices in the NTN and enabling terminal devices to accurately receive MBS.

[0187] In one possible scenario, in addition to receiving information indicating the expected service area in the SIB (such as the first information), the terminal device also receives information indicating the service area in the user service description or service announcement (such as the third information below). The terminal device can then comprehensively consider the areas obtained in different ways to determine the final area for receiving MBS. For example, if the expected service area indicated by the first information is the first area, and the service area indicated by the third information is the second area, the terminal device can receive MBS data in the intersection area of ​​the first area and the second area. In this way, it can be ensured that the terminal device can receive MBS data normally in the NTN, and the accuracy of the MBS data received by the terminal device can be guaranteed.

[0188] In one possible scenario, in addition to receiving the regional information of the MBS corresponding to the NTN, the terminal device also receives the regional information of the MBS corresponding to the TN in the TN. The terminal device can independently save these two types of regional information and receive MBS data based on different regional information in different networks.

[0189] For example, the terminal device receives information indicating the expected service area in the SIB in the NTN network (such as first information indicating area 1), and receives information indicating the service area in the service announcement in the TN network (such as second information indicating area 3), and then saves the first information and the second information; the terminal device receives MBS data in the NTN according to the first information (such as in the NTN, receiving MSB in area 1, and not receiving MBS after moving out of area 1), and / or receives MBS data in the TN according to the second information (such as in the TN, receiving MSB in area 3, and not receiving MBS after moving out of area 3).

[0190] For example, the terminal device receives information indicating the service area (such as the third information, indicating area 2) in the service announcement in the NTN network, and receives information indicating the service area (such as the second information, indicating area 3) in the service announcement in the TN network, then saves the third information and the second information; the terminal device receives MBS data in the NTN according to the third information (such as in the NTN, receiving MSB in area 2, and not receiving MBS after moving out of area 2), and / or, receives MBS data in the TN according to the second information (such as in the TN, receiving MSB in area 3, and not receiving MBS after moving out of area 3).

[0191] For example, in the NTN network, the terminal device receives information indicating the expected service area in the SIB (such as the first information, indicating area 1), and receives information indicating the service area in the service announcement (such as the third information, indicating area 2), and in the TN network, receives information indicating the service area in the service announcement (such as the second information, indicating area 3). Then, the terminal device can determine the fourth information (indicating the overlapping area of ​​area 1 and area 2) based on the first information and the third information, and save the fourth information and the second information; the terminal device receives MBS data in the NTN based on the fourth information (such as in the NTN, receiving the MSB in the overlapping area, and not receiving the MBS after moving out of the overlapping area), and / or receives MBS data in the TN based on the second information (such as in the TN, receiving the MSB in area 3, and not receiving the MBS after moving out of area 3).

[0192] The above examples are only examples and are not limited to these.

[0193] In this way, it can be ensured that the terminal device can normally receive MBS data in both TN and NTN, and the accuracy of MBS data received by the terminal device is guaranteed.

[0194] 6 , which is a flow chart of another communication method provided by the present application, which can be applied to NTN, includes S601 to S602:

[0195] S601. A core network element sends a user service description or service announcement, and a terminal device receives the user service description or service announcement.

[0196] The user service description or service announcement includes third information, which includes at least one cell identifier. The at least one cell identifier is used to determine the service area of ​​the MBS. For example, the geographical location area corresponding to the at least one cell identifier is the service area of ​​the MBS.

[0197] Optionally, the service area may be an expected service area, such as an expected service area corresponding to the NTN. The definition or content of the expected service area can be referred to the relevant content in the embodiment of FIG5 above, and will not be further described here.

[0198] The at least one cell identifier in the third information may be at least one air interface cell identifier, or at least one mapped cell identifier, or may include at least one air interface cell identifier and at least one mapped cell identifier at the same time, without limitation.

[0199] In some embodiments, the at least one cell identifier may be in the form of a cell identifier list, that is, the third information includes a list, and the at least one cell identifier is filled in the list.

[0200] The core network element may be a network element responsible for providing services, such as an AF. The user service description or service announcement sent by the AF may be transmitted via one or more network elements (such as MB-UPF, gNB, etc.) before reaching the terminal device.

[0201] In some embodiments, the core network element further generates the user service description or service announcement before sending the user service description or service announcement.

[0202] In some embodiments, the core network element further obtains the identifier of the MBS before sending the user service description or service announcement. For example, referring to FIG7A , a flowchart of obtaining the TMGI for the AF includes the following steps:

[0203] S701. AF requests NEF to allocate TMGI for MBS.

[0204] S702. NEF uses NRF to discover MB-SMF that supports MBS.

[0205] S703. NEF requests MB-SMF to allocate TMGI for MBS.

[0206] S704. The MB-SMF allocates a TMGI and sends the allocated TMGI to the NEF.

[0207] S705. The NEF sends the allocated TMGI to the AF.

[0208] After obtaining the TMGI, the AF generates a user service description or service announcement according to the TMGI, which carries the TMGI and provides at least one cell identifier corresponding to the TMGI (the cells corresponding to these cell identifiers provide MBSs identified by the TMGI).

[0209] In one possible design, the protocol or system stipulates that a user service description or service announcement only carries an air interface cell identifier or a mapped cell identifier. Thus, upon receiving a user service description or service announcement, a terminal device can clearly identify the cell identifier in the user service description or service announcement as an air interface cell identifier or a mapped cell identifier.

[0210] In another possible design, the third information carries indication information indicating the type of at least one cell identifier, including a mapped cell identifier and / or an air interface cell identifier. In this way, after receiving a user service description or service announcement, the terminal device can determine the type of the cell identifier in the user service description or service announcement based on the indication information. Optionally, the indication information can also be included in other messages without limitation.

[0211] For example, referring to FIG. 7B , after the above S705 , S706 is executed, and the AF sends a user service description or service announcement to the terminal device. The user service description or service announcement includes a cell identifier list and indication information (corresponding to S601 ).

[0212] When there are multiple cell identifiers, the types of the multiple cell identifiers can be the same (such as all air interface cell identifiers or all mapped cell identifiers) or different (such as some are air interface cell identifiers and the other are mapped cell identifiers), without limitation.

[0213] When there are multiple cell identifiers, the type can be indicated for each cell identifier separately. For example, the indication information includes multiple indication information, each cell identifier corresponds to one indication information in the multiple indication information, different cell identifiers correspond to different indication information, and the indication information corresponding to each cell identifier indicates the type of the cell identifier. Alternatively, cell identifiers of the same type correspond to the same indication information, and cell identifiers of different types correspond to another indication information. For example, multiple cell identifiers are divided into sets according to type, where the type of mapped cell identifiers is a set and corresponds to one indication information indicating the mapped cell identifier, and the type of air interface cell identifiers is a set and corresponds to one indication information indicating the air interface cell identifier. Of course, the above are only examples of some implementation methods and are not limited thereto.

[0214] In one possible implementation, the at least one cell identifier is at least one air interface cell identifier (such as an air interface cell identifier specified in the protocol, or indicated by indication information as an air interface cell identifier). In this case, the geographical location area corresponding to the at least one air interface cell identifier (i.e., the coverage area of ​​the cell corresponding to the at least one air interface cell identifier) ​​is the service area of ​​the MBS corresponding to the NTN.

[0215] Accordingly, before sending the user service description or service announcement, the core network element may determine at least one air interface cell identifier according to the geographical location information of the area where the MBS service is required (ie, the geographical location information of the service area).

[0216] It can be understood that in the NTN, the core network element can understand the mapped cell identity but does not understand the air interface cell identity. Therefore, before the core network element sends the air interface cell identity, it needs to convert the mapped cell identity into the air interface cell identity.

[0217] Exemplarily, the core network element may determine at least one air interface cell identifier corresponding to the service area of ​​the MBS corresponding to the NTN based on the correspondence between the mapped cell identifier and the air interface cell identifier. As an example, the core network element may determine the correspondence between the air interface cell identifier and the service area based on the correspondence between the mapped cell identifier and the air interface cell identifier and the correspondence between the mapped cell identifier and the service area; then, based on the correspondence between the air interface cell identifier and the service area, determine the at least one air interface cell identifier corresponding to the service area of ​​the MBS corresponding to the NTN. Of course, this is merely an example, and actual implementations are not limited thereto.

[0218] Exemplarily, the core network element may provide at least one mapped cell identifier corresponding to the service area of ​​the MBS corresponding to the NTN to another core network element, which converts the at least one mapped cell identifier into an air interface cell identifier and feeds back the conversion result.

[0219] Optionally, the core network element may obtain the correspondence between the mapped cell identifier and the air interface cell identifier from the access network element.

[0220] For example, referring to FIG7C , after S705 and before S706, the following steps are further included:

[0221] S707-S709: The AF sends a request message to request mapping of the correspondence between the cell identifier and the air interface cell identifier. Optionally, the request message may be forwarded to the gNB via the MB-SMF and / or AMF.

[0222] S710~S712, the gNB sends the correspondence between the mapped cell identifier and the air interface cell identifier; optionally, the correspondence can be forwarded to the AF via the AMF and / or MB-SMF.

[0223] In some embodiments, the above steps S707 to S712 may be combined into the session establishment request process, that is, the request message may be a session establishment request message, and the corresponding relationship may be carried in a session establishment request response message, thereby saving signaling process.

[0224] Through the above process, the AF can obtain the correspondence between the mapped cell identifier and the air interface cell identifier, and then convert the mapped cell identifier into the air interface cell identifier according to the correspondence between the mapped cell identifier and the air interface cell identifier.

[0225] Alternatively, the request message in S707 to S709 may be sent by other core network elements, such as NEF, so that NEF can obtain the correspondence between the mapped cell identifier and the air interface cell identifier from the gNB. When the AF needs to convert the mapped cell identifier into an air interface cell identifier, it may send the mapped cell identifier to other core network elements, such as NEF, and the NEF converts the mapped cell identifier into an air interface cell identifier according to the correspondence and sends the converted air interface cell identifier to the AF.

[0226] Through the above implementation, the core network element can indicate the service area by sending the air interface cell identifier to the terminal device in the user service description or service announcement.

[0227] In one possible implementation, the at least one cell identifier is at least one mapped cell identifier (such as a mapped cell identifier specified in a protocol or indicated by indication information). In this case, the geographical location area corresponding to the at least one mapped cell identifier is the service area of ​​the MBS corresponding to the NTN.

[0228] It is understood that in the NTN, terminal devices can understand air interface cell identifiers but not mapped cell identifiers. Therefore, when the core network element sends the mapped cell identifier, it can provide the terminal device with the air interface cell identifier corresponding to the mapped cell identifier or geographic location information corresponding to the mapped cell identifier, etc., to help the terminal device determine the service area based on the mapped cell. As an example, the third information can also include at least one of the following: an air interface cell identifier corresponding to at least one mapped cell identifier, and geographic location information corresponding to at least one mapped cell identifier.

[0229] For example, referring to FIG. 7D , in S706 , the user service description or service announcement sent by the AF to the terminal device includes, in addition to the mapped cell identifier list, the air interface cell identifier corresponding to each mapped cell identifier or the geographic location information corresponding to each mapped cell identifier (corresponding to S601 ).

[0230] Optionally, before sending the user service description or service announcement, the AF may determine the air interface cell identifier or geographic location information corresponding to at least one mapped cell identifier based on the correspondence between the mapped cell identifier and the air interface cell identifier. The AF may obtain the correspondence between the mapped cell identifier and the air interface cell identifier from the gNB. The acquisition method can refer to the process shown in Figure 7C and will not be expanded here.

[0231] Alternatively, before sending the user service description or service announcement, the AF may obtain the air interface cell identifier or geographic location information corresponding to at least one mapped cell identifier from the NEF. For example, the AF sends at least one mapped cell identifier to the NEF; the NEF determines the air interface cell identifier corresponding to the at least one mapped cell identifier based on the correspondence between the mapped cell identifier and the air interface cell identifier (or determines the geographic location information corresponding to the at least one mapped cell identifier based on the correspondence between the mapped cell identifier and the geographic location information), and then sends the air interface cell identifier (or geographic location information) corresponding to the at least one mapped cell identifier to the AF. Among them, the NEF can obtain the correspondence between the mapped cell identifier and the air interface cell identifier, and the correspondence between the mapped cell identifier and the geographic location information from the gNB. The specific implementation method can refer to the process shown in Figure 7C, which will not be expanded here.

[0232] Through the above implementation method, the core network element can indicate the service area by sending the mapped cell identifier and additional indication information (such as the air interface cell identifier or geographic location information corresponding to the mapped cell identifier) ​​to the terminal device in the user service description or service announcement.

[0233] In an alternative implementation, when at least one cell identifier is at least one mapped cell identifier, the core network network element may not provide the terminal device with the air interface cell identifier corresponding to the mapped cell identifier or the geographic location information corresponding to the mapped cell identifier, etc. Instead, the terminal device obtains at least one of the correspondence between the mapped cell identifier and the air interface cell identifier and the correspondence between the mapped cell identifier and the geographic location information from the access network network element, so that after receiving the third information, the terminal device can determine the service area based on these correspondences and at least one mapped cell identifier in the third information.

[0234] Specifically, the access network network element can determine the fourth information and send the fourth information to the terminal device. The terminal device receives the fourth information from the access network network element. The fourth information includes at least one of the following: the correspondence between the mapping cell identifier and the air interface cell identifier, and the correspondence between the mapping cell identifier and the geographic location information. Among them, the access network network element can actively send the fourth information, or it can be triggered by the terminal device or other network element to send the fourth information (for example, the terminal device requests the fourth information from the access network network element), without limitation. For example, referring to Figure 7D, the method also includes: S713, the terminal device obtains at least one of the correspondence between the mapping cell identifier and the air interface cell identifier, and the correspondence between the mapping cell identifier and the geographic location information from the gNB. It can be understood that this application does not limit the order of S706 and S713.

[0235] Alternatively, the fourth information includes at least one of the following: an air interface cell identifier corresponding to each mapped cell identifier in the at least one mapped cell identifier, and geographic location information corresponding to each mapped cell identifier in the at least one mapped cell identifier. In other words, the access network element can determine the air interface cell identifier or geographic location information corresponding to each mapped cell identifier and send it to the terminal device.

[0236] In a specific implementation, the access network element may send the fourth information via a system message or an RRC reconfiguration message.

[0237] Through the above implementation method, the core network element can indicate the service area by sending a mapped cell identifier to the terminal device in the user service description or service announcement, without sending additional indication information (such as the air interface cell identifier or geographic location information corresponding to the mapped cell identifier).

[0238] S602: The terminal device determines the service area of ​​the MBS corresponding to the NTN according to the third information.

[0239] According to different contents of the third information, the terminal device determines the service area of ​​the MBS corresponding to the NTN in different ways.

[0240] For example, the terminal device can determine whether the cell identifier in the third information is a mapped cell identifier or an air interface cell identifier according to the protocol provisions; or, the terminal device can determine whether the cell identifier in the third information is a mapped cell identifier or an air interface cell identifier according to the indication information in the third information.

[0241] For example, when at least one cell identifier in the third information is at least one air interface cell identifier, the terminal device can determine that the geographical location area corresponding to the at least one air interface cell identifier is the service area. When at least one cell identifier in the third information is at least one mapped cell identifier, if the third information also includes additional indication information (such as the air interface cell identifier or geographical location information corresponding to each mapped cell identifier), the terminal device can determine the service area based on the at least one mapped cell identifier and the air interface cell identifier or geographical location information corresponding to each mapped cell identifier. Alternatively, when at least one cell identifier in the third information is at least one mapped cell identifier, the terminal device can obtain the air interface cell identifier or geographical location information corresponding to each mapped cell identifier from the access network element, and then determine the service area based on the at least one mapped cell identifier and the air interface cell identifier or geographical location information corresponding to each mapped cell identifier.

[0242] After the terminal device determines the service area of ​​the MBS corresponding to the NTN, when the terminal device is located in the service area, the terminal device can receive MBS data. When the terminal device moves out of the service area, it stops or does not receive MBS data.

[0243] The above solution includes at least one cell identifier in a user service description or service announcement to indicate the service area. This allows terminal devices to clearly identify the range of MBS data they will receive within the NTN based on the user service description or service announcement, thereby enabling MBS provision and reception within the NTN for terminal devices. Furthermore, the solution provides a method for specifying the type of cell identifier in a user service description or service announcement, a process for the core network to send an air interface cell identifier in a user service description or service announcement, and a process for the core network to send a mapped cell identifier in a user service description or service announcement, further improving the accuracy of MBS provision for terminal devices within the NTN.

[0244] It can be understood that the above embodiments can be implemented separately or in combination with each other.

[0245] The method provided by the embodiment of the present application is described above in conjunction with the accompanying drawings, and the device provided by the embodiment of the present application is described below in conjunction with the accompanying drawings.

[0246] Based on the same technical concept, embodiments of the present application provide a communications device, which includes a module / unit / means for executing the method executed by any device, network element, or entity (such as a terminal device, access network element, or core network element) in the above method embodiments. The module / unit / means can be implemented by software or hardware, or the corresponding software implementation can be executed by hardware.

[0247] For example, referring to FIG8 , a schematic diagram of a communication device according to an embodiment of the present application is provided. The device includes a transceiver module 801 and optionally a processing module 802 .

[0248] For example, when the device is located in a first access network element, the functions of the modules of the device may be as follows:

[0249] The transceiver module 801 is configured to obtain first information indicating an expected service area of ​​an MBS corresponding to a non-terrestrial network;

[0250] The transceiver module 801 is further configured to send an SIB to the terminal device, where the SIB includes first information;

[0251] In one possible design, the device may also include: a processing module 802, used to generate SIB.

[0252] In one possible design, the SIB is one of the following: SIB19, SIB20, SIB21, SIB24, or SIB used to send the first information.

[0253] In one possible design, the first information includes a correspondence between the FSAI and the expected service area, where one FSAI corresponds to one or more expected service areas.

[0254] In one possible design, the first information includes coordinates of multiple location points, and the expected service area includes a polygonal area determined based on the coordinates of the multiple location points; or,

[0255] The first information includes the coordinates of a location point and a distance, and the expected service area includes a circular area with the location point as the center and the distance as the radius or diameter; or

[0256] The first information includes a proportional coefficient, and the expected service area includes an area determined by multiplying the coverage area of ​​the cell by the proportional coefficient; or,

[0257] The first information includes location information of multiple areas, and the expected service area includes an intersection area or a union area of ​​the multiple areas.

[0258] In one possible design, the transceiver module 801 is used to receive first information from a core network network element or a second access network network element.

[0259] For example, when the apparatus is located in a terminal device, the functions of the modules of the apparatus may be as follows:

[0260] The transceiver module 801 is configured to receive a SIB, where the SIB includes first information indicating an expected service area of ​​an MBS corresponding to a non-terrestrial network;

[0261] The transceiver module 801 is further configured to: stop receiving MBS data after the terminal device moves out of the expected service area;

[0262] In one possible design, the device may further include: a processing module 802, used to control the receiving module to receive SIB and stop receiving MBS data.

[0263] In one possible design, the SIB is one of the following: SIB19, SIB20, SIB21, SIB24, or SIB used to send the first information.

[0264] In one possible design, the first information includes a correspondence between the FSAI and the expected service area, where one FSAI corresponds to one or more expected service areas.

[0265] In one possible design, the first information includes coordinates of multiple location points, and the expected service area includes a polygonal area determined based on the coordinates of the multiple location points; or,

[0266] The first information includes the coordinates of a location point and a distance, and the expected service area includes a circular area with the location point as the center and the distance as the radius or diameter; or

[0267] The first information includes a proportional coefficient, and the expected service area includes an area determined by multiplying the coverage area of ​​the cell by the proportional coefficient; or,

[0268] The first information includes location information of multiple areas, and the expected service area includes an intersection area or a union area of ​​the multiple areas.

[0269] In one possible design, the expected service area indicated by the first information is the first area; the transceiver module 801 is also used for: the terminal device receives MBS data in the intersection area of ​​the first area and the second area; after the terminal device moves out of the intersection area of ​​the first area and the second area, the terminal device stops receiving MBS data; wherein the second area is the expected service area of ​​the MBS indicated in the user service description or service announcement received by the terminal device.

[0270] In one possible design, the device also includes a storage module for storing first information and second information, where the second information indicates the service area of ​​the MBS corresponding to the terrestrial network; the transceiver module 801 is also used to: receive MBS data in a non-terrestrial network according to the first information, and / or receive MBS data in a terrestrial network according to the second information.

[0271] For example, when the device is located in a core network element, the functions of the modules of the device may be as follows:

[0272] The transceiver module 801 is used to send a user service description or service announcement to the terminal device; wherein the user service description or service announcement includes third information, and the third information includes at least one cell identifier, and the at least one cell identifier is used to determine the service area of ​​the MBS corresponding to the non-terrestrial network.

[0273] In one possible design, the third information also includes indication information, where the indication information indicates the type of at least one cell identifier, including a mapped cell identifier and / or an air interface cell identifier.

[0274] In one possible design, the at least one cell identifier is at least one air interface cell identifier. The apparatus further includes: a processing module 802, configured to: determine, based on a correspondence between the mapped cell identifier and the air interface cell identifier, at least one air interface cell identifier corresponding to a service area of ​​an MBS corresponding to a non-terrestrial network.

[0275] In one possible design, the transceiver module 801 is also used to obtain the correspondence between the mapped cell identifier and the air interface cell identifier from the access network element.

[0276] In one possible design, at least one cell identifier is at least one mapped cell identifier; the third information also includes at least one of the following: an air interface cell identifier corresponding to at least one mapped cell identifier, and geographic location information corresponding to at least one mapped cell identifier.

[0277] For example, when the apparatus is located in a terminal device, the functions of the modules of the apparatus may be as follows:

[0278] The transceiver module 801 is configured to receive a user service description or service announcement; wherein the user service description or service announcement includes third information, and the third information includes at least one cell identifier;

[0279] The processing module 802 is configured to determine a service area of ​​the MBS corresponding to the non-terrestrial network according to the third information.

[0280] In one possible design, the third information also includes indication information, where the indication information indicates the type of each cell identifier in at least one cell identifier, where the type includes a mapped cell identifier and / or an air interface cell identifier.

[0281] In one possible design, at least one cell identifier is at least one air interface cell identifier.

[0282] In one possible design, at least one cell identifier is at least one mapped cell identifier; the third information also includes at least one of the following: an air interface cell identifier corresponding to at least one mapped cell identifier, and geographic location information corresponding to at least one mapped cell identifier.

[0283] In one possible design, the at least one cell identifier is at least one mapped cell identifier;

[0284] The transceiver module 801 is further configured to: receive fourth information from an access network element, the fourth information including at least one of the following: a correspondence between a mapped cell identifier and an air interface cell identifier, and a correspondence between a mapped cell identifier and geographic location information;

[0285] The processing module 802 is configured to determine a service area of ​​the MBS corresponding to the non-terrestrial network according to the third information and the fourth information.

[0286] For example, when the device is located in an access network element, the functions of the modules of the device may be as follows:

[0287] The processing module 802 is configured to determine fourth information, where the fourth information includes at least one of the following: a correspondence between a mapped cell identifier and an air interface cell identifier, and a correspondence between a mapped cell identifier and geographic location information;

[0288] The transceiver module 801 is configured to send fourth information.

[0289] It should be understood that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module and will not be repeated here.

[0290] Based on the same technical concept, referring to Figure 9, an embodiment of the present application also provides a communication device, including: at least one processor 901; and a communication interface 903 communicatively connected to the at least one processor 901; the at least one processor 901 executes instructions stored in the memory 902, so that the device executes the method steps in the above method embodiment through the communication interface 903.

[0291] Optionally, the transceiver module 801 may be a communication interface 903 , and the processing module 802 may be a processor 901 .

[0292] Optionally, the memory 902 is located outside the device.

[0293] Optionally, the apparatus includes the memory 902, the memory 902 is connected to the at least one processor 901, and the memory 902 stores instructions executable by the at least one processor 901. FIG9 uses a dotted line to indicate that the memory 902 is optional for the apparatus.

[0294] The processor 901 and the memory 902 may be coupled via an interface circuit or may be integrated together, which is not limited here.

[0295] The specific connection medium between the processor 901, memory 902, and communication interface 903 is not limited in the embodiments of the present application. In Figure 9, the processor 901, memory 902, and communication interface 903 are connected via a bus 904. The bus is represented by a bold line in Figure 9. The connection between other components is only for illustrative purposes and is not intended to be limiting. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, Figure 9 only uses a single bold line, but this does not mean that there is only one bus or only one type of bus.

[0296] Based on the same technical concept, an embodiment of the present application further provides a communication device, as shown in FIG10 , comprising a processor 1001 and an interface circuit 1002. The interface circuit 1002 is electrically coupled to the processor 1001, and the processor 1001 executes the method steps in the above method embodiment via a logic circuit or by executing code instructions. Optionally, the communication device further includes a memory.

[0297] Based on the same technical concept, an embodiment of the present application also provides a computer-readable storage medium, which stores a computer program or instruction. When the computer program or instruction is executed by a communication device, the method steps in the above method embodiment are implemented.

[0298] Based on the same technical concept, an embodiment of the present application further provides a computer program product, which includes a computer program or instructions. When the computer program or the instructions are run by a communication device, the method steps in the above method embodiment are executed.

[0299] It should be understood that the processors mentioned in the embodiments of the present application can be implemented by hardware or software. When implemented by hardware, the processor can be a logic circuit, an integrated circuit, etc. When implemented by software, the processor can be a general-purpose processor that is implemented by reading software code stored in a memory.

[0300] Exemplarily, the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0301] It should be understood that the memory mentioned in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct RAM bus random access memory (DR RAM).

[0302] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, the memory (storage module) can be integrated into the processor.

[0303] It should be noted that the memory described herein is intended to include, but not be limited to, these and any other suitable types of memory.

[0304] Based on the same technical concept, an embodiment of the present application also provides a computer-readable storage medium, which stores a computer program or instruction. When the computer program or instruction is executed by a communication device, the method steps performed by any device in the above method embodiment are implemented.

[0305] Based on the same technical concept, an embodiment of the present application also provides a computer program product, which includes a computer program or instructions. When the computer program or the instructions are run by a communication device, the method steps performed by any device in the above method embodiments are executed.

[0306] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0307] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each flow and / or box in the flow chart and / or block diagram, as well as the combination of the flow chart and / or box in the flow chart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more flow charts and / or one or more boxes in the block diagram.

[0308] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0309] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0310] Obviously, those skilled in the art may make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include these modifications and variations.

Claims

1. A communication method, characterized in that: Applied to a first access network element, the method includes: Acquire first information, where the first information indicates an expected service area of ​​a multicast broadcast service MBS corresponding to the non-terrestrial network; Sending a system information block (SIB) to a terminal device, where the SIB includes the first information; The SIB is one of the following: SIB19; SIB20; SIB21; SIB24; The SIB is used to send the first information.

2. The method according to claim 1, wherein The first information includes a correspondence between a frequency selection area identifier (FSAI) and an expected service area, wherein one FSAI corresponds to one or more expected service areas.

3. The method according to claim 1 or 2, wherein: The first information includes coordinates of a plurality of location points, and the expected service area includes a polygonal area determined based on the coordinates of the plurality of location points; or The first information includes coordinates of a location point and a distance, and the expected service area includes a circular area with the location point as the center and the distance as the radius or diameter; or The first information includes a proportional coefficient, and the expected service area includes an area determined by multiplying the coverage area of ​​the cell by the proportional coefficient; or The first information includes location information of multiple areas, and the expected service area includes an intersection area or a union area of ​​the multiple areas.

4. The method according to any one of claims 1 to 3, wherein The obtaining of the first information includes: The first information is received from a core network element or a second access network element.

5. A communication method, characterized in that: Applied to a terminal device, the method includes: receiving a system information block (SIB), where the SIB includes first information, where the first information indicates an expected service area of ​​a multicast broadcast service (MBS) corresponding to a non-terrestrial network; After the terminal device moves out of the expected service area, the terminal device stops receiving the MBS data; The SIB is one of the following: SIB19; SIB20; SIB21; SIB24; The SIB is used to send the first information.

6. The method according to claim 5, wherein The first information includes a correspondence between a frequency selection area identifier (FSAI) and an expected service area, wherein one FSAI corresponds to one or more expected service areas.

7. The method according to claim 5 or 6, wherein: The first information includes coordinates of a plurality of location points, and the expected service area includes a polygonal area determined based on the coordinates of the plurality of location points; or The first information includes coordinates of a location point and a distance, and the expected service area includes a circular area with the location point as the center and the distance as the radius or diameter; or The first information includes a proportional coefficient, and the expected service area includes an area determined by multiplying the coverage area of ​​the cell by the proportional coefficient; or The first information includes location information of multiple areas, and the expected service area includes an intersection area or a union area of ​​the multiple areas.

8. The method according to any one of claims 5 to 7, wherein: The expected service area indicated by the first information is the first area; The method further comprises: The terminal device receives the MBS data in an intersection area of ​​the first area and the second area; after the terminal device moves out of the intersection area of ​​the first area and the second area, it stops receiving the MBS data; The second area is the expected service area of ​​the MBS indicated in the user service description or service announcement received by the terminal device.

9. The method according to any one of claims 5 to 8, wherein: The method further comprises: The terminal device stores the first information and the second information, where the second information indicates a service area of ​​the MBS corresponding to the terrestrial network; The terminal device receives MBS data in the non-terrestrial network according to the first information, and / or receives MBS data in the terrestrial network according to the second information.

10. A communication method, characterized in that: Applied to a core network element, the method includes: Sending a user service description or service announcement to a terminal device; wherein the user service description or service announcement includes third information, the third information includes at least one cell identifier, and the at least one cell identifier is used to determine the service area of ​​the multicast broadcast service MBS corresponding to the non-terrestrial network.

11. The method according to claim 10, wherein The third information further includes indication information, where the indication information indicates a type of the at least one cell identifier, where the type includes a mapped cell identifier and / or an air interface cell identifier.

12. The method according to claim 10 or 11, wherein: The at least one cell identifier is at least one air interface cell identifier; The method further comprises: According to the correspondence between the mapped cell identifiers and the air interface cell identifiers, the at least one air interface cell identifier corresponding to the expected service area of ​​the MBS corresponding to the non-terrestrial network is determined.

13. The method according to claim 12, wherein: Also includes: The correspondence between the mapped cell identifier and the air interface cell identifier is acquired from an access network element.

14. The method according to claim 11 or 12, wherein: The at least one cell identifier is at least one mapped cell identifier; The third information further includes at least one of the following: an air interface cell identifier corresponding to the at least one mapped cell identifier, and geographic location information corresponding to the at least one mapped cell identifier.

15. A communication method, characterized in that: Applied to a terminal device, the method includes: receiving a user service description or a service announcement; wherein the user service description or the service announcement includes third information, and the third information includes at least one cell identifier; A service area of ​​the multicast broadcast service MBS corresponding to the non-terrestrial network is determined according to the third information.

16. The method according to claim 15, wherein The third information further includes indication information, where the indication information indicates a type of each cell identifier in the at least one cell identifier, where the type includes a mapped cell identifier and / or an air interface cell identifier.

17. The method according to claim 15 or 16, wherein: The at least one cell identifier is at least one air interface cell identifier.

18. The method according to claim 15 or 16, wherein: The at least one cell identifier is at least one mapped cell identifier; The third information further includes at least one of the following: an air interface cell identifier corresponding to the at least one mapped cell identifier, and geographic location information corresponding to the at least one mapped cell identifier.

19. The method according to claim 15 or 16, wherein: The at least one cell identifier is at least one mapped cell identifier; The method further comprises: receiving fourth information from an access network element, the fourth information including at least one of the following: a correspondence between a mapped cell identifier and an air interface cell identifier, and a correspondence between a mapped cell identifier and geographic location information; The determining, according to the fourth information, an expected service area of ​​the MBS corresponding to the non-terrestrial network includes: An expected service area of ​​the MBS corresponding to the non-terrestrial network is determined according to the third information and the fourth information.

20. A communication method, characterized in that: Applicable to access network elements, including: Determine fourth information, where the fourth information includes at least one of the following: a correspondence between a mapped cell identifier and an air interface cell identifier, and a correspondence between a mapped cell identifier and geographic location information; Send the fourth information.

21. A communication device, characterized in that: The method comprises a module or unit for executing the method according to any one of claims 1 to 4, or a module or unit for executing the method according to any one of claims 5 to 9, or a module or unit for executing the method according to any one of claims 10 to 14, or a module or unit for executing the method according to any one of claims 15 to 19, or a module or unit for executing the method according to claim 20.

22. A communication device, characterized in that: include: A processor, the processor being coupled to a memory, the memory being used to store a program or instruction, which, when executed by the processor, causes the communication device to perform the method according to any one of claims 1 to 4, or causes the communication device to perform the method according to any one of claims 5 to 9, or causes the communication device to perform the method according to any one of claims 10 to 14, or causes the communication device to perform the method according to any one of claims 15 to 19, or causes the communication device to perform the method according to claim 20.

23. A computer-readable storage medium, characterized in that The storage medium stores a computer program or instruction. When the computer program or instruction is executed by the communication device, it implements the method according to any one of claims 1 to 4, or the method according to any one of claims 5 to 9, or the method according to any one of claims 10 to 14, or the method according to any one of claims 15 to 19, or the method according to claim 20.

24. A computer program product, characterized in that The computer program product includes a computer program or instructions, and when the computer program or the instructions are executed by a communication device, the method according to any one of claims 1 to 4 is executed, or the method according to any one of claims 5 to 9 is executed, or the method according to any one of claims 10 to 14 is executed, or the method according to any one of claims 15 to 19 is executed, or the method according to claim 20 is executed.

25. A communication system, characterized in that: include: A first access network element, configured to execute the method according to any one of claims 1 to 4; A terminal device, configured to execute the method according to any one of claims 5 to 9.

26. A communication system, characterized in that: include: A core network element, configured to execute the method according to any one of claims 10 to 14; A terminal device, configured to execute the method according to any one of claims 15 to 19.

27. The system of claim 26, wherein: The system further includes an access network element configured to execute the method according to claim 20.

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