A method for satellite multicasting short messages and related apparatus

Abstract

The application discloses a method, system and related device for multicast short message transmission in a satellite communication system. The method can be applied to a first terminal, and can include: the first terminal sending an inbound multicast short message packet to a satellite network device. The inbound multicast short message packet can include a first field and a second field. The first field is used to indicate that the multicast ID of the multicast group corresponding to the inbound multicast short message packet is a first multicast ID, and the second field is used to indicate that the information content in the inbound multicast short message packet is first information content. In this way, when there is no cellular network or wireless local area network in the environment where the first terminal is located, the first terminal can send a multicast short message to other terminals through a satellite network. The multicast short message indicates the multicast ID of the multicast group corresponding to the multicast short message, so that the satellite network device can identify the multicast group corresponding to the multicast short message.

Description

Technical Field

[0001] This application relates to the field of satellite communication technology, and in particular to a method and related apparatus for multicast short message transmission in a satellite communication system. Background Technology

[0002] Satellite navigation systems are major infrastructure integrating positioning, timing, and communication. Satellite short message communication service is one of the distinctive features of satellite communication systems. It is particularly suitable for communication in areas such as oceans, deserts, grasslands, and uninhabited areas where mobile communication is unavailable, lacks coverage, or where existing communication systems are damaged. Currently, some satellite communication satellites have upgraded their short message technology, opening up necessary resources for the satellite short message service communication system. For consumer services and equipment characteristics, communication protocols need to be designed based on the specific characteristics of the satellite short message service communication system.

[0003] Because satellite communication systems lack protocols for multicast short message transmission used by terminals, terminals using the BeiDou communication system cannot send or receive multicast short messages from other terminals.

[0004] Therefore, how to achieve multicast short message transmission in satellite communication systems has become an urgent problem to be solved. Summary of the Invention

[0005] This application provides a method, system, and related apparatus for multicast short message transmission in a satellite communication system. Through the multicast short message transmission method provided in this application, even when there is no cellular network or wireless local area network in the environment where the terminal is located, the terminal can still send multicast short messages to other terminals via the satellite communication system.

[0006] In a first aspect, embodiments of this application provide a method for transmitting multicast short messages in a satellite communication system. The method is applied to a first terminal and may include: the first terminal sending an inbound multicast short message to a satellite network device. The inbound multicast short message may include a first field and a second field. The first field is used to indicate that the multicast ID of the multicast group corresponding to the inbound multicast short message is a first multicast ID, and the second field is used to indicate that the information content in the inbound multicast short message is a first information content.

[0007] Thus, when the environment where the first terminal is located has no cellular network or wireless local area network, the first terminal can send multicast short messages to other terminals via satellite network. The multicast short message indicates the ID of the multicast group to which the multicast short message belongs, allowing satellite network equipment to identify the multicast group.

[0008] In conjunction with the first aspect, in one possible implementation, the inbound multicast short message message also includes a third field, which is used to indicate that the service type of the inbound multicast short message message is a general message service type.

[0009] In conjunction with the first aspect, in one possible implementation, the first terminal sends an inbound multicast short message to the satellite network device, including: the first terminal sending one or more first user frames to the satellite network device, wherein the one or more first user frames include a fourth field, the fourth field being used to indicate that the frame type of the one or more first user frames is a multicast short message frame type.

[0010] In this way, satellite network equipment can determine that the received message is an inbound multicast short message message through one or more first user frames, and thus can send the inbound multicast short message message to the corresponding network element for processing at the lower layer of the protocol.

[0011] In conjunction with the first aspect, in one possible implementation, the inbound multicast short message message also includes a third field, which is used to indicate that the service type of the inbound multicast short message message is an inbound multicast short message type.

[0012] In this way, satellite network equipment can directly identify the received message as an inbound multicast short message through the inbound multicast short message message. Therefore, there is no need for the lower layer of the protocol to indicate that the message is an inbound multicast short message message, thus saving communication resources in the satellite network equipment.

[0013] In conjunction with the first aspect, in one possible implementation, the first terminal sends an inbound multicast short message to the satellite network device, including: the first terminal sending one or more first user frames to the satellite network device, wherein the one or more first user frames include a fourth field, the fourth field being used to indicate that the frame type of the one or more first user frames is a general data frame type.

[0014] In conjunction with the first aspect, in one possible implementation, the method further includes: a first terminal receiving a first outbound multicast short message sent by a satellite network device, the first outbound multicast short message including a fifth field and a sixth field, the fifth field indicating that the sender ID of the first outbound multicast short message is the user ID of the second terminal, and the sixth field indicating that the information content in the first outbound multicast short message is second information content; wherein, the first terminal and the second terminal belong to a first multicast group, and the multicast ID of the first multicast group is the first multicast ID.

[0015] In this way, after receiving the first outbound multicast short message, the first terminal can determine the specific sender of the first outbound multicast short message through the fifth field.

[0016] In conjunction with the first aspect, in one possible implementation, the first terminal receiving a first outbound multicast short message sent by a satellite network device includes: the first terminal receiving one or more second user frames, each of which includes a seventh field and an eighth field. The seventh field indicates that the frame type of the one or more second user frames is a multicast user frame type, and the eighth field indicates that the multicast ID of the multicast group corresponding to the one or more second user frames is a first multicast ID; the first terminal determines that the one or more second user frames are multicast short message frames based on the seventh field and parses them to obtain the first multicast ID; the first terminal obtains the first outbound multicast short message based on the one or more second user frames and parses it to obtain the user ID of the second terminal and the second information content; the first terminal displays the second information content based on the first multicast ID and the user ID of the second terminal.

[0017] In this way, one or more second user frames include the first multicast ID, so the satellite network equipment can send one or more second user frames once over the air interface, and the terminals in the multicast group corresponding to the first multicast ID can receive the one or more second user frames, saving air interface resources for satellite communication.

[0018] In conjunction with the first aspect, in one possible implementation, the method further includes: a first terminal sending a multicast short message query request message to a satellite network device, the multicast short message query request message including a service type field, the service type field being used to indicate that the service type of the multicast short message query request message is a multicast short message query type; the first terminal receiving and displaying a multicast short message query result message, the multicast short message query result message being generated by the satellite network device based on the multicast short message query request message.

[0019] In this way, the first terminal can query the number of multicast short message messages that were not successfully received through the satellite system.

[0020] In conjunction with the first aspect, in one possible implementation, the service type field is used to indicate that the service type of the multicast SMS query request message is a multicast SMS query type, and the query queries the number of multicast SMS messages sent by the specified multicast group to the first terminal; the multicast SMS query request message also includes a multicast ID field and a multicast SMS ID field, wherein the multicast ID field is used to indicate the multicast ID of the specified multicast group, and the multicast SMS ID field is used to indicate the multicast SMS ID of the last multicast SMS message successfully received by the first terminal in a series of consecutive multicast SMS messages; the multicast SMS query result message includes a multicast SMS quantity field, which is used to indicate the number of multicast SMS messages sent by the specified multicast group to the first terminal.

[0021] In this way, the first terminal can use the satellite communication system to query the number of multicast short messages that were not successfully received in a specified multicast group.

[0022] In conjunction with the first aspect, in one possible implementation, the service type field is used to indicate that the service type of the multicast SMS query request message is a multicast SMS query type, and the query queries the number of multicast SMS messages sent by all multicast groups to the first terminal; the multicast SMS query request message also includes a multicast SMS ID field, which is used to indicate the ID of the last multicast SMS message successfully received by the first terminal in a series of consecutive multicast SMS messages; the multicast SMS query result message includes a multicast SMS quantity field, which is used to indicate the number of multicast SMS messages sent by all multicast groups to the first terminal.

[0023] In this way, the first terminal can use the satellite communication system to query the number of multicast short messages that were not successfully received in all multicast groups.

[0024] In conjunction with the first aspect, in one possible implementation, the method further includes: a first terminal sending a multicast short message download request message to a satellite network device, the multicast short message download request message including a service type field, the service type field being used to indicate that the service type of the multicast short message download request message is a multicast short message download type; the first terminal receiving and displaying a second outbound multicast short message message, the second outbound multicast short message message being generated by the satellite network device based on the multicast short message download request message.

[0025] In this way, the first terminal can download the information content of the multicast short messages that were not successfully received through the satellite communication system.

[0026] In conjunction with the first aspect, in one possible implementation, the service type field is used to indicate that the service type of the multicast SMS download request message is multicast SMS download type, and that the multicast SMS message sent to the first terminal by the specified multicast group is being downloaded; the multicast SMS download request message also includes a multicast ID field and a multicast SMS ID field, the multicast ID field being used to indicate the multicast ID of the specified multicast group, and the multicast SMS ID field being used to indicate the multicast SMS ID of the last multicast SMS message successfully received by the first terminal in a series of consecutive multicast SMS messages; the second outbound multicast SMS message includes a download completion indication field, which is used to indicate whether the specified multicast group will subsequently send more multicast SMS messages to the first terminal.

[0027] In this way, the first terminal can download the content of multicast short messages that were not successfully received from a designated multicast group via the satellite system. Furthermore, the first terminal can also determine whether to continue downloading.

[0028] In conjunction with the first aspect, in one possible implementation, the service type field is used to indicate that the service type of the multicast SMS download request message is multicast SMS download type, and that all multicast SMS messages sent to the first terminal by all multicast groups are downloaded; the multicast SMS download request message also includes a multicast SMS ID field, which is used to indicate the multicast SMS ID of the last multicast SMS message successfully received by the first terminal in a series of consecutive multicast SMS messages; the second outbound multicast SMS message includes a download completion indication field, which is used to indicate whether all multicast groups will subsequently send more multicast SMS messages to the first terminal.

[0029] In this way, the first terminal can download the content of all unreceived multicast short messages in all multicast groups via the satellite system. Furthermore, the first terminal can also determine whether to continue downloading.

[0030] Secondly, embodiments of this application provide a method for multicast short message transmission in a satellite communication system. The method includes: a first terminal sending an inbound multicast short message to a satellite network device, the inbound multicast short message including a first field and a second field, the first field indicating that the multicast ID of the multicast group corresponding to the inbound multicast short message is a first multicast ID, and the second field indicating that the information content in the inbound multicast short message is a first information content; the satellite network device receiving the inbound multicast short message and parsing it to obtain the first multicast ID and the first information content; the satellite network device sending a first outbound multicast short message based on the first information content; and a second terminal receiving the first outbound multicast short message, wherein the first terminal and the second terminal belong to a first multicast group, and the multicast ID of the first multicast group is the first multicast ID.

[0031] Thus, when the environment where the first terminal is located is devoid of cellular or wireless local area networks, the first terminal can send multicast short messages to a second terminal belonging to the same multicast group via satellite network. The multicast short message contains the ID of the multicast group to which it belongs, allowing satellite network equipment to identify the multicast group.

[0032] In conjunction with the second aspect, in one possible implementation, the inbound multicast short message message also includes a third field, which is used to indicate that the service type of the multicast short message message is a general message service type.

[0033] In conjunction with the second aspect, in one possible implementation, the first terminal sends an inbound multicast short message to the satellite network device, including: the first terminal sends one or more first user frames to the satellite network device, wherein the one or more first user frames include a fourth field, the fourth field being used to indicate that the frame type of the one or more first user frames is a multicast short message frame type.

[0034] In conjunction with the second aspect, in one possible implementation, the satellite network device receives the inbound multicast short message, including: the satellite network device receives one or more first user frames and parses them to obtain a fourth field; the satellite network device determines one or more first user frames as multicast short message frames based on the fourth field; the satellite network device obtains the inbound multicast short message based on one or more first user frames and parses them to obtain a first multicast ID and a first information content.

[0035] In this way, satellite network equipment can determine that the received message is an inbound multicast short message message through one or more first user frames, and thus can send the inbound multicast short message message to the corresponding network element for processing at the lower layer of the protocol.

[0036] In conjunction with the second aspect, in one possible implementation, the inbound multicast short message includes a third field, which is used to indicate that the service type of the multicast short message is an inbound multicast short message.

[0037] In conjunction with the second aspect, in one possible implementation, the first terminal sends an inbound multicast short message to the satellite network device, including: the first terminal sending one or more first user frames to the satellite network device, wherein the one or more first user frames include a fourth field, the fourth field being used to indicate that the frame type of the one or more first user frames is a general data frame type.

[0038] In conjunction with the second aspect, in one possible implementation, the satellite network device receives an inbound multicast short message, including: the satellite network device receiving one or more first user frames; the satellite network device obtaining the inbound multicast short message based on the one or more first user frames, and parsing it to obtain a third field; the satellite network device determining the service type of the inbound multicast short message based on the third field as an inbound multicast short message type, and parsing it to obtain a first multicast ID and a first information content.

[0039] In this way, satellite network equipment can directly identify the received message as an inbound multicast short message through the inbound multicast short message message. Therefore, there is no need for the lower layer of the protocol to indicate that the message is an inbound multicast short message message, thus saving communication resources in the satellite network equipment.

[0040] In conjunction with the second aspect, in one possible implementation, the first outbound multicast short message includes a sender ID field and a fifth field. The sender ID field is used to indicate that the sender ID of the first outbound multicast short message is the user ID of the first terminal, and the fifth field is used to indicate the information content of the first outbound multicast short message.

[0041] In conjunction with the second aspect, in one possible implementation, the satellite network device sends a first outbound multicast short message based on the information content, including: the satellite network device sending one or more second user frames, the one or more second user frames including a sixth field and a seventh field, the sixth field being used to indicate that the frame type of the one or more second user frames is a multicast short message frame type, and the seventh field being used to indicate that the multicast ID of the multicast group corresponding to the one or more second user frames is a first multicast ID.

[0042] In this way, one or more second user frames include the first multicast ID, so the satellite network equipment can send one or more second user frames once over the air interface, and the terminals in the multicast group corresponding to the first multicast ID can receive the one or more second user frames, saving air interface resources for satellite communication.

[0043] In conjunction with the second aspect, in one possible implementation, the second terminal receiving the first outbound multicast short message includes: the second terminal receiving one or more second user frames and parsing them to obtain a sixth field; the second terminal determining that one or more second user frames are multicast short message frames based on the sixth field and parsing them to obtain a first multicast ID; the second terminal obtaining the first outbound multicast short message based on one or more second user frames and parsing it to obtain the user ID of the first terminal and the first information content; and the second terminal displaying the first information content based on the first multicast ID and the user ID of the first terminal.

[0044] In this way, after receiving the first outbound multicast short message, the first terminal can determine the specific sender of the first outbound multicast short message through the sixth field.

[0045] In conjunction with the second aspect, in one possible implementation, before the satellite network device sends the first outbound multicast short message based on the first information content, the method further includes: the satellite network device determining the satellite information and beam information of the first outbound multicast short message.

[0046] In this way, satellite network equipment can determine satellite information and beam information before sending the first outgoing multicast short message, thus improving the success rate of sending the first outgoing multicast short message.

[0047] In conjunction with the second aspect, in one possible implementation, the inbound multicast short message includes a location information field, which is used to indicate the location information of the first terminal; the satellite network device determines the satellite information and beam information of the first outbound multicast short message, including: the satellite network device parses the location information field based on the inbound multicast short message; the satellite network device obtains the satellite information and beam information of the first outbound multicast short message based on the location information field.

[0048] In this way, the satellite network equipment can receive the location information of the first terminal and determine the satellite information and beam information of the first outgoing multicast short message based on the location information of the first terminal, thereby improving the success rate of sending the first outgoing multicast short message.

[0049] In conjunction with the second aspect, in one possible implementation, one or more first user frames include an outbound link indication field, which is used to indicate the satellite information and beam information of the first outbound multicast short message; before the satellite network device sends the first outbound multicast short message based on the first information content, the method further includes: the satellite network device parsing the outbound link indication field based on one or more first user frames; and the satellite network device obtaining the satellite information and beam information of the first outbound multicast short message based on the outbound link indication field.

[0050] In this way, the satellite network equipment can receive the outbound link indication and determine the satellite information and beam information of the first outbound multicast short message based on the outbound link indication, thereby improving the success rate of sending the first outbound multicast short message.

[0051] In conjunction with the second aspect, in one possible implementation, the method further includes: a first terminal sending a multicast short message query request message to a satellite network device, the multicast short message query request message including a service type field, the service type field being used to indicate that the service type of the multicast short message query request message is a multicast short message query type; the satellite network device receiving the multicast short message query request message; the satellite network device generating a multicast short message query result message based on the multicast short message query request message; the satellite network device sending the multicast short message query result message to the first terminal; and the first terminal receiving and displaying the multicast short message query result message.

[0052] In this way, the first terminal can query the number of multicast short message messages that were not successfully received through the satellite system.

[0053] In conjunction with the second aspect, in one possible implementation, the service type field is used to indicate that the service type of the multicast SMS query request message is a multicast SMS query type, and the query queries the number of multicast SMS messages sent by the specified multicast group to the first terminal; the multicast SMS query request message also includes a multicast ID field and a multicast SMS ID field, the multicast ID field being used to indicate the multicast ID of the specified multicast group, and the multicast SMS ID field being used to indicate the multicast SMS ID of the last multicast SMS message successfully received by the first terminal in a series of consecutive multicast SMS messages; the multicast SMS query result message includes a multicast SMS quantity field, the multicast SMS quantity field being used to indicate the number of multicast SMS messages sent by the specified multicast group to the first terminal.

[0054] In this way, the first terminal can use the satellite communication system to query the number of multicast short messages that were not successfully received in a specified multicast group.

[0055] In conjunction with the second aspect, in one possible implementation, the service type field is used to indicate that the service type of the multicast SMS query request message is a multicast SMS query type, and the query queries the number of multicast SMS messages sent by all multicast groups to the first terminal; the multicast SMS query request message also includes a multicast SMS ID field, which is used to indicate the multicast SMS ID of the last multicast SMS message successfully received by the first terminal in a series of consecutive multicast SMS messages; the multicast SMS query result message includes a multicast SMS quantity field, which is used to indicate the number of multicast SMS messages sent by all multicast groups to the first terminal.

[0056] In this way, the first terminal can use the satellite communication system to query the number of multicast short messages that were not successfully received in all multicast groups.

[0057] In conjunction with the second aspect, in one possible implementation, the method further includes: a first terminal sending a multicast short message download request message to a satellite network device, the multicast short message download request message including a service type field, the service type field being used to indicate that the service type of the multicast short message download request message is multicast short message download type; the satellite network device receiving the multicast short message download request message; the satellite network device generating a second outbound multicast short message message based on the multicast short message download request message; the satellite network device sending the second outbound multicast short message message to the first terminal; and the first terminal receiving and displaying the second outbound multicast short message message.

[0058] In this way, the first terminal can download the information content of the multicast short messages that were not successfully received through the satellite communication system.

[0059] In conjunction with the second aspect, in one possible implementation, the service type field is used to indicate that the service type of the multicast SMS download request message is multicast SMS download type, and that the multicast SMS message sent to the first terminal by the specified multicast group is being downloaded; the multicast SMS download request message also includes a multicast ID field and a multicast SMS ID field, the multicast ID field being used to indicate the multicast ID of the specified multicast group, and the multicast SMS ID field being used to indicate the multicast SMS ID of the last multicast SMS message successfully received by the first terminal in a series of consecutive multicast SMS messages; the second outbound multicast SMS message includes a download completion indication field, which is used to indicate whether the specified multicast group will subsequently send more multicast SMS messages to the first terminal.

[0060] In this way, the first terminal can download the content of multicast short messages that were not successfully received from a designated multicast group via the satellite system. Furthermore, the first terminal can also determine whether to continue downloading.

[0061] In conjunction with the second aspect, in one possible implementation, the service type field is used to indicate that the service type of the multicast SMS download request message is multicast SMS download type, and that all multicast SMS messages sent to the first terminal by all multicast groups are downloaded; the multicast SMS download request message also includes a multicast SMS ID field, which is used to indicate the multicast SMS ID of the last multicast SMS message among the multicast SMS messages that the first terminal has successfully received consecutively; the second outbound multicast SMS message includes a download completion indication field, which is used to indicate whether all multicast groups will send more multicast SMS messages to the first terminal.

[0062] In this way, the first terminal can download the content of all unreceived multicast short messages in all multicast groups via the satellite system. Furthermore, the first terminal can also determine whether to continue downloading.

[0063] Thirdly, embodiments of this application provide a communication device including one or more processors, one or more memories, and a transceiver; wherein the transceiver, one or more memories are coupled to one or more processors, and the one or more memories are used to store computer program code, the computer program code including computer instructions, and when one or more processors execute the computer instructions, the communication device performs the method in any possible implementation of the first aspect described above.

[0064] In conjunction with the third aspect, in one possible implementation, the communication device is a terminal.

[0065] Fourthly, embodiments of this application provide a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the method in any possible implementation of the first aspect described above.

[0066] Fifthly, embodiments of this application provide a chip or chip system applied to a terminal, including a processing circuit and an interface circuit. The interface circuit is used to receive code instructions and transmit them to the processing circuit, and the processing circuit is used to run the code instructions to perform the method in any possible implementation of the first aspect described above. Attached Figure Description

[0067] Figure 1 This application provides a schematic diagram of the architecture of a satellite communication system.

[0068] Figure 2A This application provides an embodiment of a data inbound transmission process in a satellite communication system.

[0069] Figure 2B This application provides an embodiment of a data outgoing transmission process in a satellite communication system.

[0070] Figure 3 This is a schematic diagram of the structure of the terminal 100 provided in the embodiments of this application;

[0071] Figure 4 This is a schematic diagram of the protocol encapsulation architecture for inbound data of a satellite communication system 10 provided in this application embodiment;

[0072] Figure 5 This is a schematic diagram of the protocol parsing architecture for inbound data of a satellite communication system 10 provided in this application embodiment;

[0073] Figure 6 This is a schematic diagram of the protocol encapsulation architecture for outbound data of a satellite communication system 10 provided in this application embodiment;

[0074] Figure 7 This is a schematic diagram of the protocol parsing architecture for outbound data of a satellite communication system 10 provided in this application embodiment;

[0075] Figures 8A-8F This is a set of interface diagrams provided in the embodiments of this application;

[0076] Figures 9A-9B This is another set of interface diagrams provided in the embodiments of this application;

[0077] Figure 10A This application provides a schematic diagram of the multicast short message transmission process in a satellite communication system.

[0078] Figure 10B This application provides a schematic diagram of another process for multicast short message transmission in a satellite communication system;

[0079] Figure 11 This is a schematic diagram of the architecture of another satellite communication system provided in an embodiment of this application;

[0080] Figure 12A This application provides a schematic diagram of another process for multicast short message transmission in a satellite communication system;

[0081] Figure 12B This application provides a schematic diagram of another process for multicast short message transmission in a satellite communication system;

[0082] Figure 13 This is a schematic diagram of the architecture of another satellite communication system provided in an embodiment of this application;

[0083] Figure 14 This is a flowchart illustrating a method for querying the number of multicast short messages in a satellite communication system provided in this application embodiment;

[0084] Figure 15 This is a flowchart illustrating a method for downloading multicast short messages in a satellite communication system provided in this application embodiment;

[0085] Figure 16 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0086] Figure 17 This is a schematic diagram of another communication device provided in an embodiment of this application;

[0087] Figure 18 This is a schematic diagram of another communication device provided in an embodiment of this application;

[0088] Figure 19 This is a schematic diagram of another communication device provided in an embodiment of this application. Detailed Implementation

[0089] The technical solutions in the embodiments of this application will be clearly and thoroughly described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B; the word "and / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone.

[0090] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0091] The following describes a satellite communication system 10 provided in the embodiments of this application.

[0092] Figure 1 A schematic diagram of the architecture of a satellite communication system 10 provided in an embodiment of this application is shown, taking a satellite communication system as an example.

[0093] As above Figure 1 As shown, the satellite communication system 10 may include a terminal 100, a short message satellite 21, a satellite network device 200, a short message center 25, and a terminal 300. Optionally, the satellite communication system 10 may also include an emergency rescue platform 26 and an emergency rescue center 27.

[0094] Terminal 100 can send short message information to short message satellite 21. Short message satellite 21 only acts as a relay, directly forwarding the short message information sent by terminal 100 to ground satellite network equipment 200. Satellite network equipment 200 can parse the short message information forwarded by the satellite according to the satellite communication protocol, and forward the message content of the general message type parsed from the short message information to short message service center (SMSC) 25. Short message service center 25 can forward the message content to terminal 300 through traditional cellular communication network. Satellite network equipment 200 can also send emergency distress messages sent by terminal 100 to emergency rescue center 27 through emergency rescue platform 26.

[0095] Terminal 300 can also send short messages to Short Message Service (SMS) Center 25 via a traditional cellular communication network. SMS Center 25 can forward the short messages from Terminal 300 to Satellite Network Equipment 200. Satellite Network Equipment 200 can then relay the short messages from Terminal 300 to Terminal 100 via Short Message Satellite 21.

[0096] Terminal 100 can transmit its location information to Location Center 28 via a satellite communication system. Upon receiving the location information from Terminal 100, Location Center 28 stores the location information locally. This location information may include the longitude, latitude, and altitude of Terminal 100. In a Long Term Evolution (LTE) network, Location Center 28 can be a Home Subscriber Server (HSS). In a New Radio (NR) network, Location Center 28 can be a Unified Data Management (UDM) network element. Location Center 28 also stores the location information of Terminal 300 within the cellular network.

[0097] The satellite network equipment 200 may include a satellite ground transceiver station 22, a satellite central station 23, and a satellite short message fusion communication platform 24. The satellite ground transceiver station 22 may include one or more devices with transmitting and receiving functions, or it may include one or more devices with both transmitting and receiving functions; this is not limited here. The satellite ground transceiver station 22 can be used by the satellite network equipment 200 for data processing at the physical layer protocol (PHY). The satellite central station 23 can be used by the satellite network equipment 200 for data processing at the satellite link control protocol (SLC) layer and the message data convergence protocol (MDCP) layer. The satellite short message fusion communication platform 24 can be used for data processing at the application protocol (APP) layer.

[0098] Since satellite communication system 10 communicates via satellite links, its main characteristics are: long latency (approximately 270ms one-way) and high link loss. Currently, satellite communication system 10 mainly supports bursty short message services and does not support connection state management, mobility management, broadcast control information, etc.

[0099] Terminal 100 can actively send data to satellite network equipment 200 via short message satellite 21. However, due to the lack of air interface signaling, the ground central station cannot actively page the user. Because satellite communication has a long propagation distance, the satellite communication system 10 requires high transmission power from terminal 100. Limited by the current radio frequency (RF) devices on terminal 100, terminal 100 cannot continuously send signals to short message satellite 21 for extended periods. To minimize damage to the RF devices on terminal 100, after continuous operation in the transmission state for a period, the RF devices of terminal 100 must stop working for a period before switching back to the transmission state. The duration of the transmission state on terminal 100 is determined by the underlying hardware capabilities of terminal 100. In the aforementioned satellite communication system 10, to ensure that the data received and transmitted by terminal 100 do not interfere with each other, terminal 100 does not support simultaneous data transmission and reception. Terminal 100 needs to wait to receive data from satellite network equipment 200 after transmitting data.

[0100] The satellite network device 200 can operate in full-duplex mode, allowing it to send and receive data simultaneously, and it can also send and receive data for extended periods.

[0101] Figure 2A This illustration shows the data inbound transmission process in a satellite communication system provided by an embodiment of this application.

[0102] like Figure 2A As shown, data inbound can refer to terminal 100 sending data to satellite network device 200. For example, terminal 100 can send data frames to satellite ground transceiver station 22. Satellite ground transceiver station 22 can send the data frames to satellite central station 23. Satellite central station 23 can aggregate the data frames into application layer messages and report them to satellite short message fusion communication platform 24. After receiving the data frames sent by terminal 100, satellite central station 23 can return an SLC layer acknowledgment character (ACK) to terminal 100. This ACK can be used to indicate whether satellite network device 200 has successfully received the data frames sent by terminal 100.

[0103] Figure 2B This illustration shows the data outgoing transmission process in a satellite communication system provided by an embodiment of this application.

[0104] like Figure 2BAs shown, data outbound can refer to the satellite network device 200 sending data to the terminal 100. For example, the satellite short message fusion communication platform 24 in the satellite network device 200 can send application layer messages to the satellite central station 23; then the satellite central station 23 can split the application layer message into one or more data frames and send them to the satellite ground transceiver station 22, which is then relayed by the short message satellite 21 and sent to the terminal 100. Optionally, after receiving the data frame, the terminal 100 can return an SLC layer ACK to the satellite central station 23. This ACK can be used to determine whether the terminal 100 has successfully received the data frame sent by the satellite network device 200.

[0105] Figure 3 A schematic diagram of the terminal 100 is shown.

[0106] The following description uses terminal 100 as an example to illustrate the embodiment. It should be understood that... Figure 3 The terminal 100 shown is merely an example, and terminal 100 can have more than... Figure 3 The more or fewer components shown can be combined into two or more components, or they can have different component configurations. Figure 3 The various components shown can be implemented in hardware, software, or a combination of hardware and software, including one or more signal processing and / or application-specific integrated circuits.

[0107] Terminal 100 may include: processor 110, external memory interface 120, internal memory 121, universal serial bus (USB) interface 130, charging management module 140, power management module 141, battery 142, antenna 1, antenna 2, mobile communication module 150, wireless communication module 160, audio module 170, speaker 170A, receiver 170B, microphone 170C, headphone jack 170D, sensor module 180, button 190, motor 191, indicator 192, camera 193, display screen 194, and subscriber identification module (SIM) card interface 195, etc. The sensor module 180 may include a pressure sensor 180A, a gyroscope sensor 180B, a barometric pressure sensor 180C, a magnetic sensor 180D, an accelerometer sensor 180E, a distance sensor 180F, a proximity sensor 180G, a fingerprint sensor 180H, a temperature sensor 180J, a touch sensor 180K, an ambient light sensor 180L, a bone conduction sensor 180M, etc.

[0108] It is understood that the structure illustrated in the embodiments of the present invention does not constitute a specific limitation on the terminal 100. In other embodiments of this application, the terminal 100 may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0109] Processor 110 may include one or more processing units, such as: application processor (AP), modem processor, graphics processing unit (GPU), image signal processor (ISP), controller, memory, video codec, digital signal processor (DSP), baseband processor, and / or neural network processing unit (NPU), etc. Different processing units may be independent devices or integrated into one or more processors.

[0110] The controller can serve as the central nervous system and command center of the terminal 100. The controller can generate operation control signals based on the instruction opcode and timing signals to control the fetching and execution of instructions.

[0111] The wireless communication function of terminal 100 can be implemented through antenna 1, antenna 2, mobile communication module 150, wireless communication module 160, modem processor and baseband processor, etc.

[0112] Antennas 1 and 2 are used to transmit and receive electromagnetic wave signals. Each antenna in terminal 100 can be used to cover one or more communication frequency bands. Different antennas can also be multiplexed to improve antenna utilization. For example, antenna 1 can be multiplexed as a diversity antenna for a wireless local area network. In some other embodiments, the antennas can be used in conjunction with tuning switches.

[0113] The mobile communication module 150 can provide solutions for wireless communication applications including 2G / 3G / 4G / 5G on the terminal 100. The mobile communication module 150 may include at least one filter, switch, power amplifier, low-noise amplifier (LNA), etc. The mobile communication module 150 can receive electromagnetic waves via the antenna 1, and perform filtering, amplification, and other processing on the received electromagnetic waves before transmitting them to the modem processor for demodulation. The mobile communication module 150 can also amplify the signal modulated by the modem processor and convert it into electromagnetic waves for radiation via the antenna 1. In some embodiments, at least some functional modules of the mobile communication module 150 may be housed in the processor 110. In some embodiments, at least some functional modules of the mobile communication module 150 and at least some modules of the processor 110 may be housed in the same device.

[0114] The modem processor may include a modulator and a demodulator. The modulator modulates the low-frequency baseband signal to be transmitted into a mid-to-high frequency signal. The demodulator demodulates the received electromagnetic wave signal into a low-frequency baseband signal. The demodulator then transmits the demodulated low-frequency baseband signal to the baseband processor for processing. After processing by the baseband processor, the low-frequency baseband signal is transmitted to the application processor. The application processor outputs sound signals through an audio device (not limited to speaker 170A, receiver 170B, etc.) or displays images or videos through the display screen 194. In some embodiments, the modem processor may be a separate device. In other embodiments, the modem processor may be independent of the processor 110 and may be housed in the same device as the mobile communication module 150 or other functional modules.

[0115] The wireless communication module 160 can provide solutions for wireless communication applications on the terminal 100, including wireless local area networks (WLAN) (such as wireless fidelity (Wi-Fi) networks), Bluetooth (BT), global navigation satellite system (GNSS), satellite communication modules, frequency modulation (FM), near field communication (NFC), and infrared (IR) technologies. The wireless communication module 160 can be one or more devices integrating at least one communication processing module. The wireless communication module 160 receives electromagnetic waves via antenna 2, performs frequency modulation and filtering of the electromagnetic wave signals, and sends the processed signal to processor 110. The wireless communication module 160 can also receive signals to be transmitted from processor 110, perform frequency modulation and amplification, and convert them into electromagnetic waves for radiation via antenna 2.

[0116] Among them, the satellite communication module can be used to communicate with satellite network equipment. For example, in the BeiDou communication system, the satellite communication module can communicate with BeiDou network equipment, and the satellite communication module can support short message transmission between BeiDou network equipment.

[0117] In some embodiments, antenna 1 of terminal 100 is coupled to mobile communication module 150, and antenna 2 is coupled to wireless communication module 160, enabling terminal 100 to communicate with networks and other devices via wireless communication technology. The wireless communication technology may include Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Time Division Code Division Multiple Access (TD-SCDMA), Long Term Evolution (LTE), BT, GNSS, WLAN, NFC, FM, and / or IR technologies, etc. The GNSS may include the Global Positioning System (GPS), the Global Navigation Satellite System (GLONASS), the BeiDou Navigation Satellite System (BDS), the Quasi-Zenith Satellite System (QZSS), and / or satellite-based augmentation systems (SBAS).

[0118] Terminal 100 implements display functions through a GPU, display screen 194, and application processor. The GPU is a microprocessor for image processing, connected to the display screen 194 and the application processor. The GPU is used to perform mathematical and geometric calculations and for graphics rendering. Processor 110 may include one or more GPUs, which execute program instructions to generate or modify display information.

[0119] Display screen 194 is used to display images, videos, etc. Display screen 194 includes a display panel. The display panel can be a liquid crystal display (LCD). The display panel can also be manufactured using organic light-emitting diodes (OLEDs), active-matrix organic light-emitting diodes (AMOLEDs), flexible light-emitting diodes (FLEDs), miniled, microLEDs, micro-OLEDs, quantum dot light-emitting diodes (QLEDs), etc. In some embodiments, terminal 100 may include one or N displays 194, where N is a positive integer greater than 1.

[0120] The external storage interface 120 can be used to connect an external storage card, such as a Micro SD card, to expand the storage capacity of the terminal 100. The external storage card communicates with the processor 110 through the external storage interface 120 to perform data storage functions. For example, music, video, and other files can be saved on the external storage card.

[0121] Internal memory 121 can be used to store computer executable program code, which includes instructions. Processor 110 executes various functional applications and data processing of terminal 100 by running the instructions stored in internal memory 121. Internal memory 121 may include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback, image playback, etc.), etc. The data storage area may store data created during the use of terminal 100 (such as audio data, phonebook, etc.). Furthermore, internal memory 121 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, universal flash storage (UFS), etc.

[0122] Terminal 100 can implement audio functions, such as music playback and recording, through audio module 170, speaker 170A, receiver 170B, microphone 170C, headphone jack 170D, and application processor.

[0123] The SIM card interface 195 is used to connect a SIM card. The SIM card can be inserted into or removed from the SIM card interface 195 to make contact with and separate from the terminal 100. The terminal 100 can support one or N SIM card interfaces, where N is a positive integer greater than 1. The SIM card interface 195 can support Nano SIM cards, Micro SIM cards, SIM cards, etc. Multiple cards can be inserted into the same SIM card interface 195 simultaneously. The multiple cards can be of the same or different types. The SIM card interface 195 is also compatible with different types of SIM cards. The SIM card interface 195 is also compatible with external memory cards. The terminal 100 interacts with the network through the SIM card to realize functions such as calls and data communication. In some embodiments, the terminal 100 uses an eSIM, i.e., an embedded SIM card. The eSIM card can be embedded in the terminal 100 and cannot be separated from the terminal 100.

[0124] The following describes a protocol encapsulation architecture for inbound data of a satellite communication system 10 provided in the embodiments of this application.

[0125] Figure 4 This paper illustrates a schematic diagram of the protocol encapsulation architecture for inbound data of a satellite communication system 10 provided in an embodiment of this application.

[0126] like Figure 4 As shown, the satellite short message transmission protocol layer on terminal 100 can be divided into the application layer (APP), the message data convergence protocol (MDCP), the satellite link control layer (SLC), and the physical layer (PHY).

[0127] When terminal 100 sends data to satellite network device 200, the workflow of the satellite short message transmission protocol on terminal 100 can be as follows:

[0128] At the APP layer, terminal 100 can compress the original data into compressed data using a compression algorithm, and add a compression indicator field to the front of the compressed data. This compression indicator field indicates the type of compression algorithm used to compress the data. Next, terminal 100 can encrypt the compressed data to obtain encrypted data, and add an encryption indicator field to the header of the encrypted data. This encryption indicator field indicates the type of encryption algorithm used to encrypt the encrypted data. Terminal 100 can then encapsulate the encrypted data, the compression indicator field, and the encryption indicator field into an application layer message and send it to the MDCP layer. This application layer message includes a header and message data. The header includes the compression indicator field, encryption indicator field, etc. The message data includes the aforementioned encrypted data.

[0129] Optionally, terminal 100 can also encrypt the compression instruction field together with the compressed data to obtain encrypted data.

[0130] At the MDCP layer, terminal 100 can obtain application layer messages sent from the APP layer through the inter-layer interface and treat the application layer messages as an MDCP SDU (MDCP Service Data Unit). Due to air interface limitations, terminal 100 can only send physical frames of a specified length at the physical layer each time, thus constraining the length of MDCP layer data to a specified length. Therefore, at the MDCP layer, terminal 100 can add padding data to the end of the MDCP SDU to a specified length and add a redundancy length indicator field to the header of the MDCP SDU. This redundancy length indicator field can be used to indicate the length of the padding data. Terminal 100 can split the padding data and the MDCP SDU with the added redundancy length indicator field into one or more fixed-length MDCP segments (M_segment), and add a successor indicator field to the header of each MDCP segment to obtain an MDCP PDU (MDCP Protocol Data Unit). That is, the MDCP PDU includes the M_segment and the successor indicator field. The successor indication field can be used to indicate whether the current MDCP PDU is the first, middle, or last MDCP PDU among a series of consecutively transmitted MDCP PDUs; or, it can be a single MDCP PDU transmitted independently.

[0131] At the SLC layer, terminal 100 can obtain the MDCP PDU issued by the MDCP layer through the inter-layer interface, which serves as the SLC SDU (SLC Service Data Unit). At the SLC layer, terminal 100 can segment the SLC SDU into one or more (up to four) fixed-length SLC segment data (S_segment), and add frame header information to the header of each S_segment to obtain the SLC PDU (SLC Protocol Data Unit).

[0132] At the PHY layer, terminal 100 can obtain the SLC PDU issued by the SLC layer through the inter-layer interface, using it as a code block for the PHY layer. A synchronization header is added to the beginning of the code block, and a checksum field is added to the end. In the aforementioned satellite communication system 10, cyclic redundancy check (CRC) can be used to verify the code block; therefore, the checksum field can include the CRC code. Terminal 100 can encode the code block and checksum field (e.g., polar encoding) to obtain coded data, and then insert pilot signals into the coded data to obtain pilot coded data. Then, terminal 100 modulates the synchronization header and pilot coded data sequentially through the underlying hardware to obtain modulated data. Terminal 100 can spread the modulated data to obtain spread-modulated data. Terminal 100 can send the spread-modulated data to short message satellite 21, which then relays it to satellite network equipment 200.

[0133] The following describes a protocol parsing architecture for inbound data of a satellite communication system 10 provided in an embodiment of this application.

[0134] Figure 5 This illustration shows a schematic diagram of the protocol parsing architecture for inbound data of a satellite communication system 10 provided in an embodiment of this application.

[0135] like Figure 5 As shown, the satellite short message transmission protocol layer of the satellite network device 200 can be divided into the Application Protocol (APP), Message Data Convergence Protocol (MDCP), Satellite Link Control (SLC), and Physical (PHY) layers. The satellite network device 200 may include a satellite ground transceiver station 22, a satellite central station 23, and a satellite short message fusion communication platform 24. The satellite ground transceiver station 22 is responsible for protocol processing at the PHY layer. The satellite central station 23 is responsible for protocol processing at the SLC and MDCP layers. The satellite short message fusion communication platform 24 is responsible for protocol processing at the APP layer.

[0136] When satellite network device 200 receives data sent by terminal 100, the workflow of the satellite short message transmission protocol layer of satellite network device 200 can be as follows:

[0137] At the PHY layer, satellite network device 200 can acquire the modulated and spread-spectrum pilot coded data sent by terminal 100. Satellite network device 200 can despread the received spread-modulated data to obtain modulated data. Then, satellite network device 200 can demodulate the modulated data to obtain pilot coded data. Next, satellite network device 200 removes the pilot information from the pilot coded data to obtain coded data. Then, satellite network device 200 can decode the coded data and verify the integrity of the code block using the checksum in the check bit field. If complete, satellite network device 200 can extract the code block and present it to the SLC layer through the inter-layer interface as the SLC PDU of the SLC layer.

[0138] At the SLC layer, the satellite network device 200 can combine SLC PDUs belonging to the same SLC SDU into a single SLC SDU based on the frame header information of the SLC PDU. The satellite network device 200 can then present the SLC SDU to the MDCP layer through the inter-layer interface, serving as the MDCP PDU for the MDCP layer.

[0139] At the MDCP layer, satellite network device 200 can concatenate all MDCP PDUs belonging to the same MDCP SDU into a single MDCP SDU. Satellite network device 200 can then present the MDCP SDU to the APP layer via the inter-layer interface, serving as an application layer message received by the APP layer.

[0140] At the APP layer, the satellite network device 200 can decrypt and decompress the application layer message based on the message header to obtain the original data.

[0141] In the embodiments of this application, the above protocol processing procedure is only an example for illustration, and this application does not limit the specific operation of protocol processing.

[0142] The following describes a protocol encapsulation architecture for outbound data of a satellite communication system 10 provided in the embodiments of this application.

[0143] Figure 6 This illustration shows a schematic diagram of the protocol encapsulation architecture for outbound data of a satellite communication system 10 provided in an embodiment of this application.

[0144] like Figure 6As shown, the satellite short message transmission protocol layer in the satellite network device 200 can be divided into an application layer (APP), a message data convergence protocol (MDCP), a satellite link control (SLC), and a physical layer (PHY). The satellite network device 200 may include a satellite ground transceiver station 22, a satellite central station 23, and a satellite short message fusion communication platform 24. The satellite ground transceiver station 22 is responsible for protocol processing at the PHY layer. The satellite central station 23 is responsible for protocol processing at the SLC and MDCP layers. The satellite short message fusion communication platform 24 is responsible for protocol processing at the APP layer.

[0145] When satellite network device 200 sends data to terminal 100, the workflow of the satellite short message transmission protocol in satellite network device 200 can be as follows:

[0146] At the APP layer, the satellite network device 200 can compress the raw data into compressed data using a compression algorithm, and add a compression indicator field to the front of the compressed data. This compression indicator field indicates the compression algorithm type. Next, the satellite network device 200 can encrypt the compressed data and the compression indicator field together to obtain encrypted data. An encryption algorithm field is added to the header of the encrypted data, indicating the encryption algorithm type. The satellite network device 200 also needs to add a service type field to the header of the encryption algorithm field, indicating the service type of the original data. The satellite network device 200 can then encapsulate the encrypted data, compression indicator field, encryption indicator field, and service type field into an application layer message and send it to the MDCP layer. This application layer message can include a header and message data. The header can include the compression indicator field, encryption indicator field, and service type field, etc. The message data includes the aforementioned encrypted data.

[0147] At the MDCP layer, the satellite network device 200 can obtain application layer messages sent from the APP layer through the inter-layer interface and treat each application layer message as an MDCP SDU. At the MDCP layer, the satellite network device 200 can split an MDCP SDU into one or more fixed-length MDCP segments (M_segement) and add a successor indication field to the header of each MDCP segment to obtain an MDCP PDU. That is, an MDCP PDU includes an M_segement and a successor indication field. The successor indication field can be used to indicate whether the current MDCP PDU is the starting, middle, or last MDCP PDU of a series of consecutively sent MDCP PDUs; or a single MDCP PDU sent independently.

[0148] At the SLC layer, the satellite network device 200 can obtain the MDCP PDU issued by the MDCP layer through the inter-layer interface, and use it as the SLC SDU. At the SLC layer, the satellite network device 200 can segment the SLC SDU into one or more (up to four) fixed-length SLC segment data (S_segement), and add frame header information to the header of each S_segement to obtain the SLC PDU.

[0149] At the PHY layer, satellite network device 200 can obtain SLC PDUs issued by the SLC layer through the inter-layer interface. Satellite network device 200 can obtain SLC PDUs for one or more users from the SLC layer. Satellite network device 200 can concatenate multiple users' SLC PDUs together, add the physical frame header (e.g., version number) as a code block for the PHY layer, and add a check bit (e.g., cyclic redundancy check (CRC) code) to the end of the code block. The code block and CRC code are then encoded (e.g., polar encoding). The encoded physical frame, plus a reserved segment, can form the encoded data of a fixed-length physical time slot message branch (S2C_d branch). Satellite network device 200 can place multiple SLC PDUs for one user into different physical frames. Then, satellite network device 200 combines the encoded data of the S2C_d branch with the pilot information of the pilot branch (S2C_p branch) to form pilot encoded data, i.e., outbound data. Satellite network equipment 200 can send outbound data to short message satellite 21, which then relays it to terminal 100.

[0150] Understandably, the pilot information of the S2C_p branch is related to the satellite beam. When the satellite beam number is known, the pilot information of the S2C_p branch is also known and does not require decoding. However, the encoded data of the S2C_d branch requires decoding.

[0151] The following describes a protocol parsing architecture for outbound data of a satellite communication system 10 provided in an embodiment of this application.

[0152] Figure 7 This illustration shows a schematic diagram of the protocol parsing architecture for outbound data of a satellite communication system 10 provided in an embodiment of this application.

[0153] like Figure 7 As shown, the satellite short message transmission protocol layer of terminal 100 can be divided into the application layer (APP), the message data convergence protocol (MDCP), the satellite link control layer (SLC), and the physical layer (PHY).

[0154] When terminal 100 receives data sent by satellite network equipment, the workflow of the satellite short message transmission protocol layer of terminal 100 can be as follows:

[0155] At the PHY layer, terminal 100 can obtain the modulated and spread-spectrum pilot coded data sent by satellite network equipment 200. Terminal 100 can despread the received spread-modulated data to obtain modulated data. Then, terminal 100 can demodulate the modulated data to obtain pilot coded data. Next, terminal 100 can remove the pilot information from the pilot coded data to obtain coded data. Then, terminal 100 can decode the coded data and verify the integrity of the code block through the check bit field. If complete, terminal 100 can extract the code block and present it to the SLC layer through the inter-layer interface as the SLC PDU of the SLC layer.

[0156] Here, the pilot coded data is the outgoing data sent by the aforementioned satellite network device 200. This outgoing data consists of the coded data of the S2C_d branch and the pilot information of the pilot branch (S2C_p branch).

[0157] At the SLC layer, terminal 100 can concatenate SLC PDUs belonging to the same SLC SDU into a single SLC SDU based on the frame header information of the SLC PDU. Terminal 100 can then present the SLC SDU to the MDCP layer through the inter-layer interface, serving as the MDCP PDU for the MDCP layer.

[0158] At the MDCP layer, terminal 100 can concatenate all MDCP PDUs belonging to the same MDCP SDU into a single MDCPSDU. Terminal 100 can then present the MDCP SDU to the APP layer through the inter-layer interface, serving as an application layer message received by the APP layer.

[0159] At the APP layer, terminal 100 can decrypt and decompress the application layer message based on the message header to obtain the original data.

[0160] In the embodiments of this application, the above protocol processing procedure is only an example for illustration, and this application does not limit the specific operation of protocol processing.

[0161] In one possible implementation, terminal 100 cannot use network resources other than satellite networks (e.g., cellular networks), i.e., it is in a state without signal, for example, when terminal 100 is in areas where mobile communication is not covered, or cannot be covered, or where the communication system is damaged, such as oceans, deserts, grasslands, or uninhabited areas. Terminal 100 can communicate with other terminals via satellite networks. Specifically, terminal 100 joins a first multicast group, and can send multicast short messages to other terminals in the first multicast group via satellite networks, and can also receive multicast short messages sent to terminal 100 by other terminals in the first multicast group via satellite networks. In this way, users can achieve multicast short message transmission via satellite systems through terminal 100.

[0162] Specifically, terminal 100 can respond to a user's input of sending a multicast short message, and in response to that input, generate an inbound multicast short message based on the user-input text message and the multicast ID. Terminal 100 can send the inbound multicast short message to satellite network device 200. The inbound multicast short message includes a first type indication field and a multicast ID field. The first type indication field is used to indicate the service type of the inbound multicast short message, and the multicast ID field is used to indicate the multicast group to which the inbound multicast short message belongs.

[0163] The following section presents a set of interface diagrams provided in the embodiments of this application.

[0164] For example, such as Figure 8AAs shown, terminal 100 can display desktop 801. Desktop 801 can include multiple application icons, such as a first communication application icon 803, etc. The first communication application icon 803 can be used to trigger the display of the interface of the first communication application (e.g., ...). Figure 8B The first communication application interface 810 shown can be used to receive / send satellite short messages. For example, the first communication application can be SMS, MeeTime, etc. A status bar 802 can also be displayed above the desktop 801. This status bar 802 can display a prompt icon 802A, which indicates that the terminal 100 has lost communication with the cellular network. At this time, the terminal 100 is in a state without cellular signal.

[0165] Terminal 100 receives input from the user regarding the first communication application icon 803 (e.g., a click), and in response to this input, terminal 100 can display, as shown below. Figure 8B The first communication application interface 810.

[0166] like Figure 8B As shown, the first communication application interface 810 may include a new control 811, which can be used to trigger the terminal 100 to display a contact selection interface. The first communication application interface 810 may also display a multicast group control 812 and historical contact entries. The historical contact entries may display information about historical contacts and their recent message records. The historical contact entries can also be used to trigger the terminal 100 to display a message editing interface for that historical contact. The multicast group control 812 can be used to trigger the terminal 100 to display a multicast group function interface (such as...). Figure 8C The multicast group function interface shown is 820.

[0167] Terminal 100 receives user input (e.g., a click) to the multicast group control 812, and in response to this input, terminal 100 can display the multicast group functionality interface 820. For example... Figure 8C As shown, the multicast group function interface may include a new control 821, which can be used to trigger the terminal 100 to display the multicast group selection interface. The multicast group function interface 820 may also display historical multicast group entries, which may display information about historical multicast groups and their most recent message records. Historical multicast group entries may also be used to trigger the terminal 100 to display the message editing interface for that historical multicast group.

[0168] Terminal 100 receives user input (e.g., a click) for the newly created control 821. In response to this input, terminal 100 can display, as shown below. Figure 8DThe multicast group selection interface 830 is shown. This multicast group selection interface 830 can display a multicast group display area 831. The multicast group display area 831 can display multiple multicast group icons, such as multicast group icon 831A. The multicast group icon can be used to trigger the display of the information editing interface for the multicast group communication corresponding to the multicast group icon.

[0169] Terminal 100 receives input from the user for the multicast group icon 831C (e.g., a click). In response to this input, terminal 100 can display the multicast group information editing interface 840 of the third group corresponding to the multicast group icon 831C.

[0170] like Figure 8E As shown, the multicast group information editing interface 840 may include, but is not limited to, an editing bar 841 and a sending control 842. The editing bar 841 can be used to display the text message content entered by the user. The sending control 842 can be used to trigger the terminal 100 to send a multicast short message containing the text message content displayed in the editing bar 841 to the satellite network device 200. The multicast group information editing interface 840 may also display a keyboard display area 843 and more icons 844. The keyboard display area 843 can be used to input text message content, and the more icons 844 can be used to trigger the display of user member information in the multicast group.

[0171] Terminal 100 can receive user input for the keyboard display area 843 and display the user's input in the editing bar 841. For example... Figure 8E As shown, the terminal 100 can receive and display text messages entered by the user in the editing bar 841 through the keyboard display area 843. The text message could be "Safely arrived at the campsite".

[0172] Terminal 100 can receive user input (e.g., a click) to the send control 842, and in response to the input, terminal 100 can display, for example, Figure 8F The multicast group information editing interface 850 shown is included. The multicast group information editing interface 850 may include a multicast information box 851. The multicast information box 851 can be used to display the content sent by the user in the editing bar 841.

[0173] After receiving an inbound multicast short message from terminal 100, satellite network device 200 identifies the message as a multicast short message. It then parses the multicast ID from the message and forwards it to other terminals in the multicast group indicated by that ID. For example, if the multicast group indicated by the ID is the third group, and its members include terminal 100, terminal 200, and terminal 300, satellite network device 200 will send the multicast short message to both terminals 200 and 300. Terminal 200 or terminal 300 can then display the multicast short message upon receiving it.

[0174] It is understood that the user interface illustrated in the embodiments of the present invention does not constitute a specific limitation on the terminal 100. In other embodiments of this application, the terminal 100 may employ other user interfaces.

[0175] The following is another set of interface diagrams provided in the embodiments of this application.

[0176] In one possible implementation, after receiving a multicast short message, terminal 200 can display a receipt information prompt, which can be used to notify the user that a multicast short message has been received from terminal 100.

[0177] For example, terminal 200 can display as follows Figure 9A The desktop 900 shown can include multiple application icons, such as a first communication application icon. This first communication application icon can be used to trigger the display of the first communication application's interface, which can be used to receive / send satellite SMS messages. For example, the first communication application could be SMS, MeeTime, etc.

[0178] The desktop 900 can also display a status bar 901 at the top, which can display a prompt icon 901A. Prompt icon 901A indicates that the terminal 200 has lost communication with the cellular network, and at this time, the terminal 200 is in a state without cellular signal. The status bar 901 can also display a prompt icon 901B, which indicates that the terminal 200 is within satellite signal coverage and can use a satellite communication system for communication.

[0179] Above multiple application icons, a received message notification 902 can be displayed. The received message notification 902 can be used to notify the user that a satellite multicast short message has been received from terminal 100. For example, the received message notification 902 can include a text message: "Received a satellite multicast short message from terminal 100." The received message notification 902 can also include an application identifier 903, which can be used to indicate the application software that displays the satellite message. For example, the application identifier 903 can be used to instruct terminal 200 to receive the satellite multicast short message through a first communication application. That is, the application identifier 903 can prompt the user to view the satellite message through the first communication application. After receiving user input (e.g., a click) on the received message notification 902, terminal 200, in response to the input, can display the content of the received satellite short message through the first communication application.

[0180] Terminal 200 can receive user requests for, such as Figure 9A Upon receiving the input (e.g., clicking) shown in the message prompt 902, in response to that input, the following is displayed: Figure 9B The information editing interface shown is 910.

[0181] For example, such as Figure 9B As shown, the information editing interface 910 may include an information box 911. The information box 911 can be used to display the content of the text message in the received multicast short message. Optionally, the information box 911 can also display the sender of the multicast short message, such as terminal 100. Optionally, the information box 911 can also display the time information of the multicast short message being sent. Figure 9B Not shown in the image. Among them, Figure 9B The fourth group shown is the terminal 200, that is, the third group in the terminal 100 corresponds to the fourth group in the terminal 200. This application embodiment does not limit this.

[0182] It is understood that the user interface illustrated in the embodiments of the present invention does not constitute a specific limitation on the terminal 200. In other embodiments of this application, the terminal 200 may employ other user interfaces.

[0183] Figure 10A This illustration shows a flowchart of multicast short message transmission in a satellite communication system provided in an embodiment of this application.

[0184] like Figure 10A As shown, the method includes:

[0185] S1001, Terminal 100 generates an inbound multicast short message based on text information and multicast ID.

[0186] Specifically, terminal 100 can use the text message and multicast ID as raw data, and obtain an application layer message based on the raw data. This application layer message is an inbound multicast short message. For a detailed description of how terminal 100 obtains the application layer message based on the raw data, please refer to [link to relevant documentation]. Figure 4 The embodiments shown will not be described in detail here.

[0187] In some embodiments, terminal 100 may receive user data such as... Figure 8E After the operation, a text message and a multicast ID are obtained. The text message indicates that the user has safely arrived at the campsite, and the multicast ID is the multicast ID corresponding to the third group selected by the user.

[0188] In one possible implementation, member terminals in the third group of terminal 100 can negotiate with the corresponding application server under a cellular network to determine the multicast ID or group virtual beam information (e.g., synchronization header information) of the third group, which is used to indicate the identifier of the third group in the satellite communication system. The terminal device can then identify the received physical layer data as a multicast short message message using the group virtual beam information at the physical layer.

[0189] In one possible implementation, the format of the inbound multicast short message can be as shown in Table 1 below.

[0190] Table 1

[0191]

[0192] As shown in Table 1 above, an inbound multicast short message may include a receipt indication field, a service type field, an encryption indication field, a compression indication field, an application layer authentication code field, a multicast ID field, and a text message field. It is understood that the specific fields included in the inbound multicast short message in this embodiment are not limited in their order. For example, when an inbound multicast short message does not require an application layer receipt by default, the receipt indication field may not be included in the inbound multicast short message.

[0193] The detailed descriptions of each field in the inbound multicast short message message shown in Table 1 can be found in Table 2 below.

[0194] Table 2

[0195]

[0196]

[0197] As shown in Table 2, the receipt indication field can be used to indicate whether the receiving device (e.g., satellite network device 200) of the inbound multicast short message needs to reply with an application layer receipt to the terminal 200. The application layer receipt can be used to indicate whether the receiving device has successfully received the inbound multicast short message. The length of the receipt indication field can be 1 bit. When the receipt indication field is a value D1 (e.g., 0), it can be used to indicate that the receiving device of the inbound multicast short message does not need to reply with an application layer receipt to the terminal 200. When the receipt indication field is a value D2 (e.g., 1), it can be used to indicate that the receiving device of the inbound multicast short message needs to reply with an application layer receipt to the terminal 200. It is understood that the embodiments of this application do not limit the length of the receipt indication field or its specific value.

[0198] As shown in Table 2, the service type field can be used to indicate the service type of the inbound multicast short message. In satellite short message communication, the service type of the message can include general message, multicast multi-message query, and multicast short message download, etc. The length of the service type field can be 4 bits. It is understood that the length of the service type field is not limited in this embodiment. As the number of service types increases, the length of the service type field can become longer. This embodiment uses a 4-bit length service type field as an example. When the service type field is 0000, it indicates that the application layer message is a general message. The meanings of other values ​​of the service type indication field can be found in Table 2, and will not be repeated here. It should be noted that in this embodiment, the service type of the inbound multicast short message is the general message service type.

[0199] As shown in Table 2, the encryption indicator field can be used to indicate whether the inbound multicast short message is encrypted. For example, the length of the encryption indicator field can be 2 bits. When the encryption indicator field is the value D3 (e.g., 00), it indicates that the inbound multicast short message is not encrypted. It is understood that this application embodiment does not limit the length of the encryption indicator field or its specific value.

[0200] As shown in Table 2, the compression indicator field can be used to indicate whether the inbound multicast short message is compressed. For example, the length of the compression indicator field can be 2 bits. When the compression indicator field is the value D4 (e.g., 00), it indicates that the inbound multicast short message is not compressed. It is understood that this application embodiment does not limit the length of the compression indicator field or its specific value.

[0201] As shown in Table 2, the multicast ID field can be used to indicate the identifier of the multicast group corresponding to the inbound multicast short message. The length of the multicast ID field can be 10 bits. It is understood that the embodiments of this application do not limit the length of the multicast ID field.

[0202] As shown in Table 2, the text message field can be used to indicate the content of the inbound multicast short message. The length of the text message field can be N bits. It is understood that the embodiments of this application do not limit the length of the text message field.

[0203] Optionally, the inbound multicast short message may also include a location information field, which can be used to indicate the current location of terminal 100. This location information may include the longitude and latitude of terminal 100's current location. Terminal 100 may obtain its current location information based on a satellite navigation system, such as a Global Navigation Satellite System (GNSS), BeiDou Navigation Satellite System (BDS), etc.

[0204] S1002, Terminal 100 generates one or more first user frames based on inbound multicast short messages.

[0205] Specifically, terminal 100 can forward inbound multicast short message packets to the MDCP layer via the inter-layer interface. Terminal 100 can then segment the inbound multicast short message packets into one or more MDCP PDUs at the MDCP layer. Next, terminal 100 forwards the one or more MDCP PDUs to the SLC layer. At the SLC layer, terminal 100 can segment each MDCP PDU into one or more first user frames. At the SLC layer, terminal 100 can fill in its identifier (e.g., terminal 100's mobile phone number) in the user ID field of the frame header of each first user frame. For more details, please refer to [link / reference]. Figure 4 The description of the inbound data encapsulation process in the China Satellite Communication System 10 will not be repeated here.

[0206] In one possible implementation, the format of the first user frame can be as shown in Table 3 below.

[0207] Table 3

[0208]

[0209] As shown in Table 3, the first user frame may include a version number field, a frame type indicator field, a user ID field, an outbound link indicator field, an AM-Enable field, an NDI (New Data Indicator) field, a total number of frames field, a frame sequence number field, a user information field, etc. It is understood that the specific fields included in the first user frame and the order of the fields are not limited in this embodiment.

[0210] The specific descriptions of each field in the first user frame shown in Table 3 can be found in Table 4 below.

[0211] Table 4

[0212]

[0213]

[0214] As shown in Table 4, the version number field indicates the version of the currently used satellite communication protocol. The data length of this version number field can be 3 bits. It is understood that the embodiments of this application do not limit the length of the version number field. In some embodiments, the version number field may not be included in the first user frame.

[0215] As shown in Table 4, the frame type field can be used to indicate the frame type of the first user frame. The data length of the frame type field can be 3 bits. Frame types can include general data frames (or information message frames), ACK frames, acknowledgment frames, location reporting frames, emergency rescue frames, multicast short message frames, etc. It should be noted that in this embodiment, the frame type of the first user frame is a multicast short message frame.

[0216] As shown in Table 4, the User ID field can be used to indicate the device identifier of terminal 100. The data length of this User ID field can be 34 bits. It is understood that this application embodiment does not limit the length of the User ID field.

[0217] As shown in Table 4, the outbound link indication field is used to indicate the satellite information and beam information of the outbound multicast short message. The data length of this outbound link indication field can be 16 bits. It is understood that the length of the outbound link indication field is not limited in this embodiment. In some embodiments, the outbound link indication field may not be included in the first user frame.

[0218] As shown in Table 4, the AM-Enable field is used to indicate whether the receiver needs to provide acknowledgment information for the first user frame. The data length of the AM-Enable field can be 1 bit. When the AM-Enable field is a value A1 (e.g., 0), it indicates that the first user frame does not require acknowledgment information from the receiver; when the AM-Enable field is a value A2 (e.g., 1), it indicates that the first user frame requires acknowledgment information from the receiver. It is understood that the length of the AM-Enable field is not limited in this embodiment. In some embodiments, the AM-Enable field may not be included in the first user frame.

[0219] As shown in Table 4, the NDI field is used to indicate whether the first user frame is a retransmitted user frame. The data length of the NDI field can be 1 bit. Specifically, when the NDI is flipped, it indicates that the first user frame is not a retransmitted user frame. It is understood that the embodiments of this application do not limit the length of the NDI field. In some embodiments, the first user frame may not include the NDI field.

[0220] As shown in Table 4, the total frame count field can be used to indicate the total number of user frames included in the SLC SDU containing the first user frame. The length of this total frame count field can be 2 bits. When the length of the total frame count field is 2 bits, a single SLC SDU can include a maximum of 4 location reporting frames. It is understood that the embodiments of this application do not limit the length of the total frame count field.

[0221] As shown in Table 4, the frame sequence number field can be used to indicate the order of the multicast short message frame in an SLC SDU. The length of the frame sequence number field can be 2 bits.

[0222] As shown in Table 4, the user information field can be used to indicate the data content of the first user frame. Specifically, the data content of the first user frame is all or part of the SLC SDU. It is understood that the embodiments of this application do not limit the length of the user information field.

[0223] It is understandable that the frame type indication field of the first user frame is obtained by the terminal 100 at the SLC layer based on the message service type indication sent by the APP layer. For example, when the APP layer sends an inbound multicast short message message through the inter-layer interface, it indicates that the service type of the inbound multicast short message message message is the inbound multicast short message type. Then, the terminal 100 sets the frame type to the multicast short message frame type at the SLC layer.

[0224] S1003, terminal 100 sends one or more first user frames to satellite network device 200.

[0225] Terminal 100 can send one or more first user frames to satellite network device 200. See here for details. Figure 4 The description of the inbound data encapsulation process in the China Satellite Communication System 10 will not be repeated here.

[0226] In some embodiments, after receiving a user's first input, the terminal 100 may, in response to the first input, generate and send one or more first user frames to the satellite network device 200. The first input is not limited to single-click, double-click, long-press, swipe, voice command input, etc. For example, the first input can be one of the above-mentioned... Figure 8E The input shown is for the send control 842.

[0227] S1004, the satellite network device 200 determines that the first user frame is a multicast short message frame, and obtains the multicast ID and text information based on one or more first user frames.

[0228] After receiving one or more first user frames, satellite network device 200 can determine that the first user frame is a multicast short message frame based on the frame type field at the SLC layer, determine the sender ID based on the user ID field, and obtain the multicast ID and text information based on one or more first user frames. For example, the sender ID can be the mobile phone number of terminal 100.

[0229] Specifically, satellite network device 200 assembles one or more first user frames sent by terminal 100 into one or more SLC SDUs at the SLC layer. Then, satellite network device 200 uploads these one or more SLC SDUs to the MDCP layer as one or more MDCP PDUs. Then, satellite network device 200 can assemble one or more MDCPPDUs into an MDCP SDU at the MDCP layer. Finally, satellite network device 200 can upload the MDCP SDU to the APP layer as an inbound multicast short message. (See reference here.) Figure 4 The decapsulation process of incoming data in the satellite communication system will not be described here.

[0230] Optionally, the inbound multicast short message includes location information, and the satellite network device 200 can obtain the location information based on the MDCP SDU at the APP layer.

[0231] Optionally, the first user frame includes an outbound link indication field, which is used to indicate the satellite information and beam information of the outbound multicast short message. The satellite network device 200 can obtain the outbound link indication information based on the first user frame at the SLC layer.

[0232] In some embodiments, such as Figure 1In the illustrated architecture diagram of the satellite communication system, the satellite network device 200 includes a satellite central station 23 and a satellite short message fusion communication platform 24. After determining that the first user frame is a multicast short message frame based on the frame type field at the SLC layer, the satellite central station 23 obtains an MDCP SDU based on one or more first user frames at the MDCP layer. The satellite central station 23 sends the MDCP SDU and the frame type of the first user frame to the satellite short message fusion communication platform 24. The satellite short message fusion communication platform 24 obtains the text information and multicast ID based on the MDCP SDU at the APP layer. Optionally, the inbound multicast short message includes location information, and the satellite short message fusion communication platform 24 can also obtain the location information based on the MDCP SDU at the APP layer. Optionally, the first user frame includes an outbound link indication field, which is used to indicate the satellite information and beam information of the outbound multicast short message. The satellite central station 23 also sends the outbound link indication information to the satellite short message fusion communication platform 24.

[0233] In some embodiments, such as Figure 11 In the illustrated architecture diagram of the satellite communication system, the satellite network device 200 includes a satellite central station 23, a satellite short message fusion communication platform 24, and a broadcast multicast center 29. After determining that the first user frame is a multicast short message frame based on the frame type field at the SLC layer, the satellite central station 23 obtains an MDCP SDU based on one or more first user frames at the MDCP layer. The satellite central station 23 sends the MDCP SDU and the frame type of the first user frame to the broadcast multicast center 29. The broadcast multicast center 29 obtains the text information and multicast ID based on the MDCP SDU at the APP layer. Optionally, the inbound multicast short message includes location information, and the broadcast multicast center 29 can also obtain the location information based on the MDCP SDU at the APP layer. Optionally, the first user frame includes an outbound link indication field, which is used to indicate the satellite information and beam information of the outbound multicast short message. The satellite central station 23 also sends the outbound link indication information to the broadcast multicast center 29.

[0234] It should be noted that, in Figure 11 In the satellite communication system architecture diagram shown, the broadcast multicast center 29 and the location center 28 can communicate with each other. Optionally, the broadcast multicast center 29 can communicate with the short message center 25, and the short message center 25 can communicate with the location center 28. Figure 11 The connection method is not shown in the diagram. This application does not limit the specific connection method described in the embodiments.

[0235] S1005, the satellite network device 200 determines the target user ID based on the multicast ID in the inbound short message message, and determines the satellite information and beam information of the outbound multicast short message.

[0236] Satellite network device 200 can obtain the multicast ID field and text information from the inbound multicast short message message. Satellite network device 200 can determine the target user ID of the text information based on the multicast ID field. For example, when satellite network device 200 determines that the multicast group corresponding to the multicast ID is the third group based on the multicast ID field, and the member information of the third group is terminal 100, terminal 200, and terminal 300, then satellite network device 200 determines that the target user ID of the text information is the user ID of terminal 200 and the user ID of terminal 300. Optionally, satellite network device 200 can query the location center 28 for the member terminal information of the multicast group corresponding to the multicast ID, and location center 28 can send the member terminal information of the multicast group to satellite network device 200 based on the multicast ID.

[0237] Optionally, the first user frame includes an outbound link indication field, and the satellite network device 200 determines the satellite information and beam information of the outbound multicast short message based on the outbound link indication field at the SLC layer.

[0238] Optionally, the inbound multicast short message includes location information, which is the location of terminal 100. Satellite network device 200 determines the satellite information and beam information of the outbound multicast short message based on the location information. Specifically, satellite network device 200 can generate a circle with the location of terminal 100 as the center and a radius of a first length. The satellites and beams within this circle are determined as the satellite information and beam information of the outbound multicast short message. The first length can be 10 kilometers; however, this embodiment does not limit the specific value of the first length.

[0239] Optionally, the satellite network device 200 can request the location information of the terminal 100 from the location center 28. The satellite network device 200 can send the user ID information of the terminal 100 to the location center 28. After the location center 28 retrieves the location information of the terminal 100 based on the user ID, it sends the location information of the terminal 100 back to the satellite network device 200. The satellite network device 200 determines the satellite information and beam information of the outgoing multicast short message based on the location information. The specific determination method can be found in the description of the above embodiments, and will not be repeated here.

[0240] In some embodiments, the satellite network device 200 may request the location information of the terminal 100 from the location center 28 in response to receiving an inbound multicast short message.

[0241] In some embodiments, the satellite network device 200 may periodically request the location information of the terminal 100 from the location center 28 and store the obtained location information of the terminal 100 locally.

[0242] In some embodiments, the satellite network device 200 requests the location information of the terminal 100 from the location center 28, and instructs the location center 28 to send the location information of the terminal 100 to the satellite network device 200 when the location of the terminal 100 changes. The satellite network device 200 stores the obtained location information of the terminal 100 locally.

[0243] In some embodiments, such as Figure 1 In the architecture diagram of the satellite communication system shown, the satellite network device 200 includes a satellite central station 23 and a satellite short message fusion communication platform 24. After receiving the MDCP SDU and the frame type of the first user frame sent by the satellite central station 23, the satellite short message fusion communication platform 24 obtains the multicast ID field and text information based on the MDCP SDU at the APP layer. The satellite short message fusion communication platform 24 can determine the target user ID of the text information based on the multicast ID field. The specific determination method can be referred to the description of the above embodiment, and will not be repeated here.

[0244] Optionally, the first user frame includes an outbound link indication field. The satellite center station 23 obtains this outbound link indication field at the SLC layer based on the first user frame and sends it to the satellite short message fusion communication platform 24. The satellite short message fusion communication platform 24 determines the satellite information and beam information of the outbound multicast short message based on the outbound link indication field. In one possible implementation, the satellite center station 23 obtains the outbound link indication field at the SLC layer based on the first user frame and determines the satellite information and beam information of the outbound multicast short message based on the outbound link indication field. The satellite center station 23 then sends the satellite information and beam information to the satellite short message fusion communication platform 24.

[0245] Optionally, the inbound multicast short message includes location information, which the satellite short message fusion communication platform 24 obtains at the APP layer based on the MDCP SDU. The satellite short message fusion communication platform 24 then determines the satellite information and beam information of the outbound multicast short message based on the location information. The specific determination method can be found in the description of the above embodiments, and will not be repeated here.

[0246] Optionally, the satellite short message fusion communication platform 24 can send a location query request to the location center 28 through the short message center 25. This location query request is used to request the location information of the terminal 100. The satellite short message fusion communication platform 24 can send the user ID information of the terminal 100 to the location center 28. After the location center 28 retrieves the location information of the terminal 100 based on the user ID, it sends the location information of the terminal 100 back to the satellite short message fusion communication platform 24. The satellite short message fusion communication platform 24 determines the satellite information and beam information of the outgoing multicast short message based on the location information. The specific methods for determining the satellite information and beam information can be referred to the description of the above embodiments, and will not be repeated here. The specific location request method can be referred to the description of the above embodiments, and will not be repeated here.

[0247] In some embodiments, such as Figure 11 In the architecture diagram of the satellite communication system shown, the satellite network device 200 includes a satellite central station 23, a satellite short message fusion communication platform 24, and a broadcast multicast center 29. After receiving the MDCP SDU and the frame type of the first user frame sent by the satellite central station 23, the broadcast multicast center 29 obtains the multicast ID field and text information based on the MDCP SDU at the APP layer. The broadcast multicast center 29 can determine the target user ID of the text information based on the multicast ID field. The specific determination method can be referred to the description of the above embodiment, and will not be repeated here.

[0248] Optionally, the first user frame includes an outbound link indication field. Satellite center station 23 obtains this outbound link indication field at the SLC layer based on the first user frame and sends it to broadcast / multicast center 29. Broadcast / multicast center 29 determines the satellite information and beam information of the outbound multicast short message based on the outbound link indication field. In one possible implementation, satellite center station 23 obtains the outbound link indication field at the SLC layer based on the first user frame and determines the satellite information and beam information of the outbound multicast short message based on the outbound link indication field. Satellite center station 23 then sends the satellite information and beam information to broadcast / multicast center 29.

[0249] Optionally, the inbound multicast short message includes location information, which the broadcast multicast center 29 obtains at the APP layer based on the MDCP SDU. The broadcast multicast center 29 then determines the satellite information and beam information of the outbound multicast short message based on the location information. The specific determination method can be found in the description of the above embodiments, and will not be repeated here.

[0250] Optionally, the broadcast multicast center 29 can request the location information of the terminal 100 from the location center 28. The broadcast multicast center 29 can send the user ID information of the terminal 100 to the location center 28. After the location center 28 retrieves the location information of the terminal 100 based on the user ID, it sends the location information of the terminal 100 back to the broadcast multicast center 29. The broadcast multicast center 29 determines the satellite information and beam information of the outgoing multicast short message based on the location information. The specific methods for determining the satellite information and beam information can be found in the description of the above embodiments and will not be repeated here. The specific location request method can also be found in the description of the above embodiments and will not be repeated here.

[0251] S1006, Satellite Network Equipment 200 generates outbound multicast short message messages based on text information and multicast ID.

[0252] Specifically, the satellite network device 200 can use text information, sender ID, and multicast ID as raw data, and obtain application layer messages based on the raw data. These application layer messages are outbound multicast short message messages.

[0253] In some embodiments, such as Figure 1 In the architecture diagram of the satellite communication system shown, the satellite network device 200 includes a satellite central station 23 and a satellite short message fusion communication platform 24. The satellite short message fusion communication platform 24 uses the text message, the sender's user ID and multicast ID as raw data at the APP layer, and obtains the application layer message based on the raw data. The application layer message is an outbound multicast short message message.

[0254] In some embodiments, such as Figure 11 In the architecture diagram of the satellite communication system shown, the satellite network device 200 includes a satellite central station 23, a satellite short message fusion communication platform 24, and a broadcast multicast center 29. The broadcast multicast center 29 uses the text message, the sender's user ID, and the multicast ID as raw data at the APP layer, and obtains the application layer message based on the raw data. The application layer message is an outbound multicast short message message.

[0255] In one possible implementation, the format of the outbound multicast short message is shown in Table 5.

[0256] Table 5

[0257]

[0258] As shown in Table 5 above, a multicast short message message may include a message type indicator field, a multicast short message download completion indicator field, an encryption indicator field, a compression indicator field, an application layer authentication code field, a multicast group quantity field, a multicast ID field, a sender ID field, a message original sending time field, a multicast short message content field, and a multicast short message ID field. It is understood that the specific fields included in the multicast short message message in this embodiment are not limited in their order. For example, if the multicast short message message is not encrypted, the encryption indicator field may not be included.

[0259] The detailed descriptions of each field in the outbound multicast short message message shown in Table 5 can be found in Table 6 below. Table 6 provides an example of the length and detailed description of each field in Table 5.

[0260] Table 6

[0261]

[0262]

[0263] As shown in Table 6, the message type indicator field can be used to indicate the message type of the outbound multicast short message. In satellite short message communication, the message type can include mailbox overview, letter message, multicast short message query result, and multicast short message, etc. The length of the message type indicator field can be 2 bits. It is understood that the length of the message type indicator field is not limited in this application embodiment. As the number of message types increases, the length of the message type indicator field can become longer. This application embodiment uses a message type indicator field length of 2 bits as an example for illustration. When the message type indicator field is 00, it indicates that the application layer message is a message overview message. The meanings of other values ​​of the message type indicator field can be found in Table 6, and will not be repeated here. It should be noted that in this application embodiment, the message type of the outbound multicast short message is a multicast short message type.

[0264] For details regarding the encryption indicator field, compression indicator field, and application layer authentication code field in Table 6, please refer to the description in S1001, which will not be repeated here.

[0265] As shown in Table 6, the multicast SMS download completion indication field can be used to indicate whether there are any more multicast SMS messages to be sent to the terminal 200. The length of this multicast SMS download completion indication field can be 1 bit. When the multicast SMS download completion indication field is a value M1 (e.g., 1), it can be used to indicate that there are any more multicast SMS messages to be sent to the terminal 200. When the multicast SMS download completion indication field is a value M2 (e.g., 0), it can be used to indicate that there are no more multicast SMS messages to be sent to the terminal 200. It is understood that the embodiments of this application do not limit the length and specific value of the multicast SMS download completion indication field. It should be noted that the outbound multicast SMS message may not include this multicast SMS download completion indication field.

[0266] As shown in Table 6, the multicast ID can be used to indicate the ID of the multicast group corresponding to the multicast short message. For example, the data length of the multicast ID can be 10 bits. It is understood that the embodiments of this application do not limit the length of the multicast ID field.

[0267] As shown in Table 6, the sender ID field can be used to indicate the identifier of the target terminal sending the multicast short message. For example, the sender ID field can be a 34-bit identifier of the target terminal (e.g., a mobile phone number). It is understood that this application embodiment does not limit the length of the sender ID field or its specific values.

[0268] As shown in Table 6, the original sending time field of the multicast SMS message is used to indicate the original sending time of the multicast SMS message, that is, the time when the target terminal sent the multicast SMS message. For example, the length of the original sending time field of the multicast SMS message can be 7 bits. It is understood that the embodiments of this application do not limit the length of the original sending time field of the multicast SMS message.

[0269] As shown in Table 6, the multicast SMS ID field is used to indicate the ID of the multicast SMS. For example, the length of the multicast SMS ID field can be 4 bits. It is understood that the embodiments of this application do not limit the length of the multicast SMS ID field.

[0270] As shown in Table 6, the multicast message content field can be used to indicate the content of the multicast message sent by the target multicast group to the terminal 200. For example, the length of the multicast message content field can be N bits. It is understood that this application embodiment does not limit the length of the multicast message content field.

[0271] In some embodiments, when the multicast ID indicates a multicast group of a subscription service, the subscription service can be provided by an application server, and execution begins directly from S1006. The application server can send text information and the multicast ID to the satellite network device 200. It should be noted that the outbound multicast short message may not include a sender ID field.

[0272] S1007, Satellite Network Equipment 200 segments outgoing multicast short message messages into one or more second user frames.

[0273] Specifically, satellite network device 200 can send outgoing multicast short message packets and target user IDs to the MDCP layer. Satellite network device 200 can segment the outgoing multicast short message packets into one or more MDCP PDUs at the MDCP layer. Then, satellite network device 200 sends one or more MDCP PDUs to the SLC layer as SLC SDUs, and sends the target user IDs to the SLC layer. Satellite network device 200 can segment each SLC SDU into one or more second user frames at the SLC layer. At the SLC layer, satellite network device 200 can fill in the target user ID in the user ID field of each second user frame. The process of satellite network device 200 segmenting outgoing multicast short message packets into one or more second user frames can be found in [reference needed]. Figure 6 The specific description will not be repeated here. It should be noted that, in the embodiments of this application, the frame type of one or more second user frames is a general data frame type.

[0274] In some embodiments, such as Figure 1 In the architecture diagram of the satellite communication system shown, the satellite network device 200 includes a satellite central station 23 and a satellite short message fusion communication platform 24. The satellite short message fusion communication platform 24 can send outgoing multicast short message messages and target user IDs to the satellite central station 23. The satellite central station 23 segments the outgoing multicast short message messages into one or more second user frames.

[0275] In some embodiments, such as Figure 11 In the architecture diagram of the satellite communication system shown, the satellite network equipment 200 includes a satellite central station 23, a satellite short message fusion communication platform 24, and a broadcast multicast center 29. The broadcast multicast center 29 sends outgoing multicast short message packets and target user IDs to the satellite central station 23. The satellite central station 23 segments the outgoing multicast short message packets into one or more second user frames.

[0276] S1008, Satellite network equipment 200 sends one or more second user frames to the target user.

[0277] Satellite network device 200 can use the satellite information and beam information determined in S1005 to send one or more second user frames to the target user. Specifically, satellite network device 200 can send one second user frame, receive a successful reception reply from the target user, and then send a second second user frame to the target user. Optionally, satellite network device 200 can also send one or more second user frames to the target user sequentially, and the target user can reply to satellite network device 200 with a successful reception reply after receiving all the second user frames. Alternatively, the target user may not reply. This application embodiment does not limit this.

[0278] It is understood that, in this embodiment, the outbound multicast short message is an outbound multicast short message sent to a specific target terminal. When there are N target users in the group to which the multicast ID belongs, the satellite network device 200 executes S1007 and S1008 N times in a loop. For example, when the group to which the multicast ID belongs is a third group, and the third group includes terminal 100, terminal 200, and terminal 300, the satellite network device 200 executes S1007 and S1008 respectively with terminal 200 and terminal 300 as target users.

[0279] In this embodiment of the application, the target user is terminal 200 as an example for explanation.

[0280] S1009, Terminal 200 receives one or more second user frames.

[0281] Terminal 200 can receive one or more second user frames. For details on the reception process, please refer to [reference needed]. Figure 7 The description of the illustrated embodiments will not be repeated here.

[0282] In one possible implementation, after the terminal 200 has received one or more second user frames, it replies to the satellite network device 200 that it has received one or more second user frames.

[0283] Furthermore, terminal 200 can parse the user ID field in the frame header of each second user frame at the SLC layer. If the user ID parsed by terminal 200 from the user ID field is the same as the identifier of terminal 200, then terminal 200 uploads the one or more second user frames to the MDCP layer for further parsing. If the user ID parsed by terminal 200 from the user ID field is different from the identifier of terminal 200, then terminal 200 can determine that the second user frame was not sent to terminal 200, and terminal 200 can discard the second user frame.

[0284] S1010, Terminal 200 assembles one or more second user frames into an outbound multicast short message.

[0285] Specifically, terminal 200 can assemble one or more SLC SDUs from one or more second user frames at the SLC layer. Then, terminal 200 uploads the one or more SLC SDUs to the MDCP layer as one or more MDCP PDUs. Then, terminal 200 can assemble one or more MDCP PDUs into an MDCP SDU at the MDCP layer. Finally, terminal 200 can upload the MDCPSDU to the APP layer as an outbound multicast short message. (See reference here.) Figure 7 The decapsulation process of outgoing data from the satellite communication system will not be described here.

[0286] S1011, Terminal 200 parses the content of the multicast short message sent by Terminal 100 to Terminal 200 in the outbound multicast short message message.

[0287] Terminal 200 can obtain the multicast ID field, sender ID field, and multicast short message content field, etc., based on the multicast short message message at the APP layer, thereby determining the multicast group and sender corresponding to the multicast short message.

[0288] S1012, Terminal 200 displays the content of the multicast short message sent by Terminal 100 to Terminal 200.

[0289] Terminal 200 can display the content of a multicast short message sent to terminal 200 by a target multicast group on its display screen. For example, if the sender ID is the user ID of terminal 100, and the multicast ID indicates the fourth multicast group in terminal 200, then terminal 100 will use a first communication application to display the message content in the fourth group. The sender of the message content is terminal 100. (See reference...) Figure 9B As shown. Terminal 200 may also prompt the user with the content of the short message sent to terminal 200 by the target multicast group in other forms. For example, terminal 200 may verbally announce the content of the email sent to terminal 200 by the target multicast group. This application embodiment does not limit the specific display form.

[0290] Thus, through the multicast short message transmission method in a satellite communication system provided in this application embodiment, terminal 100, even when not residing in a cellular network, can send multicast short messages to other terminals in a target multicast group via the satellite network.

[0291] Figure 12A This paper illustrates a flowchart of a multicast short message transmission process in another satellite communication system provided in an embodiment of this application.

[0292] like Figure 12A As shown, the method includes:

[0293] S1201, Terminal 100 generates an inbound multicast short message based on text information and multicast ID.

[0294] The specific process by which terminal 100 generates inbound multicast short message packets based on text information and multicast ID can be found in the detailed description of S1001, and will not be repeated here.

[0295] The format of the inbound multicast short message can be found in Table 1, and will not be repeated here.

[0296] It should be noted that, in this embodiment of the application, the value of the service type field in the inbound multicast short message can be 1011, which is used to indicate that the service type of the inbound multicast short message is a multicast short message. That is, in this embodiment of the application, the service type indication field is used to indicate that the application layer message is an inbound multicast short message.

[0297] S1202, Terminal 100 generates one or more first user frames based on inbound multicast short messages.

[0298] The specific process by which terminal 100 generates one or more first user frames based on inbound multicast short messages can be found in the detailed description of S1002, and will not be repeated here.

[0299] The format of the first user frame can be found in Table 3, and will not be described again here.

[0300] It should be noted that, in this embodiment of the application, the frame type field of the first user frame is set to 0000, which is used to indicate that the first user frame is a general data frame.

[0301] S1203, terminal 100 sends one or more first user frames to satellite network device 200.

[0302] The specific process by which terminal 100 sends one or more first user frames to satellite network device 200 can be found in the detailed description of S1003, and will not be repeated here.

[0303] S1204, Satellite network equipment 200 determines that the received application layer message is an inbound multicast short message based on the service type indication field.

[0304] Satellite network device 200 can obtain MDCPSDU based on one or more first user frames at the SLC layer and MDCP layer. Satellite network device 200 can upload the MDCP SDU to the APP layer, treating it as an application layer message, i.e., an inbound multicast short message message. The inbound multicast short message message includes a service type indication field, which satellite network device 200 uses to determine that the application layer message is an inbound multicast short message message. Optionally, the inbound multicast short message message includes location information, which satellite network device 200 can obtain at the APP layer based on the MDCP SDU. Optionally, the first user frame includes an outbound link indication field, which indicates the satellite information and beam information of the outbound multicast short message. Satellite network device 200 can obtain the outbound link indication information at the SLC layer based on the first user frame.

[0305] In some embodiments, such as Figure 1 In the illustrated architecture diagram of the satellite communication system, the satellite network device 200 includes a satellite central station 23 and a satellite short message fusion communication platform 24. The satellite central station 23 obtains an MDCP SDU based on one or more first user frames at the SLC and MDCP layers. The satellite central station 23 sends an MDCPSDU to the satellite short message fusion communication platform 24 as an application layer message. The satellite short message fusion communication platform 24 obtains a service type indication field, text information, and multicast ID based on this application layer message at the APP layer. The satellite short message fusion communication platform 24 determines that the application layer message is an inbound multicast short message message based on the service type indication field. Optionally, the inbound multicast short message message includes location information, and the satellite short message fusion communication platform 24 can also obtain location information based on the MDCP SDU at the APP layer. Optionally, the first user frame includes an outbound link indication field, which is used to indicate the satellite information and beam information of the outbound multicast short message. The satellite center station 23 also sends outbound link indication information to the satellite short message fusion communication platform 24.

[0306] In some embodiments, such as Figure 11In the illustrated architecture diagram of the satellite communication system, the satellite network device 200 includes a satellite central station 23, a satellite short message fusion communication platform 24, and a broadcast multicast center 29. The satellite central station 23 obtains an MDCP SDU based on one or more first user frames at the SLC and MDCP layers. The satellite central station 23 sends the MDCP SDU to the satellite short message fusion communication platform 24 as an application layer message. The satellite short message fusion communication platform 24 obtains a service type indication field, text information, and multicast ID based on this application layer message at the APP layer. Based on the service type indication field, the satellite short message fusion communication platform 24 determines that the application layer message is an inbound multicast short message and sends the service type indication field, text information, and multicast ID to the broadcast multicast center 29. Optionally, the inbound multicast short message includes location information. The satellite short message fusion communication platform 24 can also obtain the location information based on the MDCP SDU at the APP layer and send the location information to the broadcast multicast center 29.

[0307] It should be noted that, in Figure 11 In the satellite communication system architecture diagram shown, the broadcast multicast center 29 and the location center 28 can communicate with each other. Optionally, the broadcast multicast center 29 can communicate with the short message center 25, and the short message center 25 can communicate with the location center 28. Figure 13 The connection method is not shown in the diagram. This application does not limit the specific connection method described in the embodiments.

[0308] In one possible implementation, the satellite short message fusion communication platform 24 determines that the application layer message is an inbound multicast short message based on the service type indication field, and can send the MDCP SDU to the broadcast multicast center 29. The broadcast multicast center 29 obtains the service type indication field, text information, and multicast ID at the APP layer based on the application layer message. Optionally, the inbound multicast short message includes location information, and the broadcast multicast center 29 can obtain the location information at the APP layer based on the application layer message.

[0309] Optionally, the first user frame includes an outbound link indication field, which is used to indicate the satellite information and beam information of the outbound multicast short message. The satellite center station 23 also sends outbound link indication information to the satellite short message fusion communication platform 24, and the satellite short message fusion communication platform 24 sends outbound link indication information to the broadcast multicast center 29.

[0310] S1205, the satellite network device 200 determines the target user ID based on the multicast ID in the inbound short message message, and determines the satellite information and beam information of the outbound multicast short message.

[0311] S1206, Satellite Network Equipment 200 generates outbound multicast short message messages based on text information and multicast ID.

[0312] In some embodiments, when the multicast ID indicates a multicast group of a subscription service, the subscription service can be provided by an application server, and execution begins directly from S1206. The application server can then send text information and the multicast ID to the satellite network device 200.

[0313] S1207, Satellite Network Equipment 200 segments outgoing multicast short message messages into one or more second user frames.

[0314] S1208, Satellite network equipment 200 sends one or more second user frames to the target user.

[0315] In this embodiment of the application, the target user is terminal 200 as an example for explanation.

[0316] S1209, Terminal 200 receives one or more second user frames.

[0317] S1210, Terminal 200 assembles one or more second user frames into an outbound multicast short message.

[0318] S1211, Terminal 200 parses the content of the multicast short message sent by Terminal 100 to Terminal 200 in the outbound multicast short message message.

[0319] S1212, Terminal 200 displays the content of the multicast short message sent by Terminal 100 to Terminal 200.

[0320] exist Figure 12A In the process of S1205-S1212 and Figure 10A The processes in S1005-S1012 are similar and will not be repeated here for the sake of brevity.

[0321] In some embodiments, the multicast group pre-agreed on the time point for sending outgoing multicast short messages, and the satellite short message fusion communication platform 24 or the broadcast multicast center 29, as well as the member terminals in the multicast group, all store the time point information for sending the outgoing multicast short messages. S1006 and S1206 in this embodiment can be replaced by S1006A. Before S1009 and S1209 in this embodiment, S1009A is also included.

[0322] S1006A: Satellite network equipment 200 generates outbound multicast short message messages based on the time information of outbound multicast short message transmission, and on the basis of text information and multicast ID.

[0323] Specifically, satellite network device 200 obtains the pre-agreed outbound multicast message transmission time information of the corresponding multicast group based on the multicast ID. For example, the multicast group corresponding to the multicast ID is the third group in terminal 100, and the pre-agreed outbound multicast short message transmission time of the third group in terminal 100 is the hour, such as 13:00. Then, satellite network device 200 can generate an outbound multicast short message packet based on text information and multicast ID at time 13:00. The specific process of generating the outbound multicast short message packet can be found in the description of the above embodiment, and will not be repeated here.

[0324] S1009A, Terminal 200 performs satellite acquisition operations based on the time information of the outgoing multicast short message, and completes the acquisition of satellite signals to achieve synchronization with the satellite system.

[0325] In some scenarios, terminal 200 cannot receive outbound multicast short messages from short message satellites before completing the satellite pairing operation. Therefore, terminal 200 must complete the satellite pairing operation before preparing to receive outbound multicast short messages. Specifically, terminal 200 can start the satellite pairing operation at a time one hour before the outbound multicast short message is sent. For example, the multicast group corresponding to the multicast ID is the third group in terminal 100, and the outbound multicast message sending time pre-agreed upon by the third group in terminal 100 is the hour, such as 13:00. In one possible implementation, terminal 200 can start the satellite pairing operation at 12:55. In another possible implementation, terminal 200 can receive a notification message at 12:55, and the user can perform the satellite pairing operation based on the notification message. The notification message may include text notification messages or voice notification messages, which are not limited in this embodiment.

[0326] In some embodiments, the multicast group pre-agreed on the time points for multicast short message transmission (including the sending time point and the receiving time point). The satellite short message fusion communication platform 24 or the broadcast multicast center 29, as well as the member terminals in the multicast group, all store the time point information for the multicast short message transmission. In this embodiment, S1001 and S1201 can be replaced by S1001A. In this embodiment, S1006 and S1206 can be replaced by S1006B. In this embodiment, S1009B is included before S1009 and S1209.

[0327] S1001A, Terminal 100 generates an inbound multicast short message based on the time point information of the multicast short message transmission, and on the basis of the text information and the multicast ID.

[0328] Specifically, terminal 100 obtains the pre-agreed multicast SMS transmission time information of the corresponding multicast group based on the multicast ID. For example, the multicast group corresponding to the multicast ID is the third group in terminal 100, and the pre-agreed multicast SMS transmission time of the third group in terminal 100 is the hour, such as 13:00. Then, terminal 100 can generate an inbound multicast SMS message based on the text information and multicast ID at time 13:00. The specific process of generating the inbound multicast SMS message can be found in the description of the above embodiments, and will not be repeated here. In one possible implementation, after receiving the user's multicast SMS sending operation, terminal 100 can cache the multicast SMS and automatically generate an inbound multicast SMS message at the agreed multicast SMS transmission time.

[0329] In some scenarios, terminal 100 cannot send inbound multicast short messages to satellite network device 200 before completing the satellite pairing operation. Therefore, terminal 100 must perform a satellite pairing operation before sending an inbound multicast short message to satellite network device 200. Specifically, terminal 100 can start the satellite pairing operation at a time one duration prior to the multicast short message transmission time. For example, the multicast group corresponding to the multicast ID is the third group in terminal 100, and the multicast short message transmission time agreed upon in advance by the third group in terminal 100 is the hour, such as 13:00, etc. In one possible implementation, terminal 100 can start the satellite pairing operation at 12:55. In another possible implementation, terminal 100 can receive a notification message at 12:55, and the user can perform the satellite pairing operation based on the notification message. The notification message includes text notification information or voice notification information, which is not limited in this embodiment.

[0330] S1006B, Satellite Network Equipment 200 generates outbound multicast short message messages based on the time point information of multicast short message transmission, and on the basis of text information and multicast ID.

[0331] For details, please refer to the description in S1006A, which will not be repeated here.

[0332] S1009B, Terminal 200 performs satellite acquisition operations based on the time information of the multicast short message transmission to achieve synchronization with the satellite system.

[0333] For details, please refer to the description in S1009A, which will not be repeated here.

[0334] In some embodiments, terminal 200 can obtain the time point information of outbound multicast short message sending or multicast short message transmission by actively querying. Specifically, terminal 200 can send a multicast period query request message to satellite network device 200, the multicast period query request message carrying multicast ID information. Satellite network device 200 generates a multicast period query result message based on the multicast ID and sends the multicast period query result message to terminal 200.

[0335] In some embodiments, the second user frame may be indicated as a multicast user frame, and the multicast ID corresponding to the second user frame may be indicated in the second user frame. In this embodiment, S1006 and S1206 can be replaced with S1006C. In this embodiment, S1007 and S1207 can be replaced with S1007A. In this embodiment, S1009 and S1209 can be replaced with S1009C. In this embodiment, S1010 and S1210 can be replaced with S1010A. In this embodiment, S1011 and S1211 can be replaced with S1011A. For a detailed process, please refer to... Figure 10B and Figure 12B .

[0336] S1006C, Satellite Network Equipment 200 generates outbound multicast short message messages based on text information.

[0337] Specifically, the satellite network device 200 can use text information and sender ID as raw data, and obtain application layer messages based on the raw data. These application layer messages are outbound multicast short message messages.

[0338] In one possible implementation, the format of the outbound multicast short message is shown in Table 5 above. For details of each field, please refer to the description in S1006. It will not be repeated here.

[0339] In one possible implementation, in this embodiment of the application, the outbound multicast short message may not include a message type indicator field. Optionally, the outbound multicast short message may include a message type indicator field, which may have a value of 11, used to indicate that the application layer message is an outbound multicast short message. This embodiment of the application does not limit this.

[0340] In one possible implementation, outbound multicast short message messages may not include a multicast ID field.

[0341] S1007A, satellite network equipment 200 segments outgoing multicast short message messages into one or more second user frames.

[0342] Specifically, satellite network device 200 can send outgoing multicast short message packets and multicast IDs to the MDCP layer, indicating that the type of the outgoing multicast short message packet is an outgoing multicast short message. Satellite network device 200 can segment the outgoing multicast short message packets into one or more MDCP PDUs at the MDCP layer. Then, satellite network device 200 sends one or more MDCP PDUs to the SLC layer as SLC SDUs, and sends the multicast ID and the type of the outgoing multicast short message packet to the SLC layer. Satellite network device 200 can segment each SLC SDU into one or more second user frames at the SLC layer. At the SLC layer, satellite network device 200 can fill in the multicast short message frame type in the frame type indication field of each second user frame and the multicast ID in the multicast ID field. The process of satellite network device 200 segmenting outgoing multicast short message packets into one or more second user frames can be found in [reference needed]. Figure 6 The specific details will not be repeated here.

[0343] In one possible implementation, the format of the second user frame is shown in Table 7.

[0344] Table 7

[0345]

[0346] As shown in Table 7, the second user frame may include a frame type field, a frame length field, a multicast ID field, a total number of frames field, a frame sequence number field, a user information field, etc. Optionally, the second user frame may also include an AM-Enable field.

[0347] The specific descriptions of each field in the second user frame shown in Table 7 can be found in Table 8 below.

[0348] Table 8

[0349]

[0350]

[0351] As shown in Table 8, the frame type field can be used to indicate the frame type of the second user frame. The data length of the frame type field can be 2 bits. Frame types can include general data frames (or information message frames), ACK frames, acknowledgment frames, multicast short message frames, etc. In this embodiment, the frame type of the second user frame is a multicast short message frame. It is understood that this embodiment does not limit the length of the frame type field.

[0352] As shown in Table 8, the frame length field can be used to indicate the data length of user information in the second user frame. The data length of the frame length field can be 8 bits or 9 bits. It is understood that this application embodiment does not limit the length of the frame length field.

[0353] As shown in Table 8, the multicast ID field is used to indicate the ID of the multicast group corresponding to the second user frame. The data length of the multicast ID field can be 10 bits. It is understood that the embodiments of this application do not limit the length of the multicast ID field.

[0354] As shown in Table 8, the total frame count field can be used to indicate the total number of user frames included in the SLC SDU containing the second user frame. The length of this total frame count field can be 2 bits. When the length of the total frame count field is 2 bits, a single SLC SDU can include a maximum of 4 location reporting frames. It is understood that the embodiments of this application do not limit the length of the total frame count field.

[0355] As shown in Table 8, the frame sequence number field can be used to indicate the order of the multicast short message frame within an SLC SDU. The length of this frame sequence number field can be 2 bits.

[0356] As shown in Table 8, the user information field can be used to indicate the data content of the second user frame. It is understood that the embodiments of this application do not limit the length of the user information field.

[0357] In another possible implementation, the format of the second user frame is shown in Table 9.

[0358] Table 9

[0359]

[0360] As shown in Table 9, the second user frame may include a frame type field, a frame length field, a broadcast / multicast indication field, a multicast ID field, a total number of frames field, a frame sequence number field, a user information field, etc.

[0361] The specific descriptions of each field in the second user frame shown in Table 9 are as described in Table 8 above. It should be noted that when the frame type field is 11, it indicates that the second user frame is a broadcast-multicast user frame. The second user frame also includes a broadcast-multicast indication field and a broadcast-multicast ID field. The broadcast-multicast indication field can be 1 bit long. When the broadcast-multicast indication field is a value C1 (e.g., 0), it can be used to indicate that the second user frame is a multicast short message frame, in which case the broadcast-multicast ID field is used to indicate the multicast ID information; when the broadcast-multicast indication field is a value C2 (e.g., 1), it can be used to indicate that the second user frame is a broadcast short message frame, in which case the broadcast-multicast ID field is used to indicate the broadcast ID information.

[0362] S1009C, Terminal 200 receives one or more second user frames.

[0363] Terminal 200 can receive one or more second user frames. For details on the reception process, please refer to [reference needed]. Figure 7 The description of the illustrated embodiments will not be repeated here.

[0364] In one possible implementation, terminal 200 determines that the second user frame is a multicast short message frame based on the frame type field, and determines the ID of the multicast group corresponding to the second user frame based on the multicast ID field.

[0365] In one possible implementation, terminal 200 determines that the second user frame is a broadcast multicast short message frame based on the frame type field. Further, terminal 200 determines that the second user frame is a multicast short message frame based on the broadcast multicast indication field.

[0366] Terminal 200 can determine whether the second user frame was sent to terminal 200 based on the multicast ID field. If it is determined that the ID of the multicast group belongs to the multicast group of terminal 200, then it can be determined that the second user frame was sent to terminal 200, and terminal 200 uploads one or more second user frames to the MDCP layer for further parsing; if it is determined that the ID of the multicast group does not belong to the multicast group of terminal 200, then it can be determined that the second user frame was not sent to terminal 200, and terminal 200 can discard the second user frame.

[0367] S1010A, terminal 200 assembles one or more second user frames into an outbound multicast short message.

[0368] Specifically, terminal 200 can assemble one or more SLC SDUs from one or more second user frames at the SLC layer. Then, terminal 200 uploads the one or more SLC SDUs to the MDCP layer as one or more MDCP PDUs, and sends the multicast ID to the MDCP layer. Then, terminal 200 can assemble the one or more MDCP PDUs into an MDCPSDU at the MDCP layer. Finally, terminal 200 can upload the MDCP SDU to the APP layer as an outbound multicast short message, and send the multicast ID to the APP layer. (See reference here.) Figure 7 The decapsulation process of outgoing data from the satellite communication system will not be described here.

[0369] S1011A, Terminal 200 parses the content of the multicast short message sent by Terminal 100 to Terminal 200 in the outbound multicast short message message.

[0370] Terminal 200 can obtain the sender ID field and multicast short message content field, etc., based on the multicast short message message at the APP layer, and obtain the multicast ID from the MDCP layer, thereby determining the multicast group and sender corresponding to the multicast short message.

[0371] In this embodiment, the satellite network device 200 can indicate that the second user frame is a multicast user frame and indicate the multicast ID in the second user frame. In this way, the satellite network device 200 only needs to send one outbound multicast short message, and all member terminals in the multicast group can receive the outbound multicast short message.

[0372] It should be noted that in this embodiment, terminal 100 may also receive one or more second user frames, which do not include a user ID field. Terminal 100 cannot determine whether one or more second user frames were sent to terminal 100 through the user ID field. Terminal 100 can obtain outbound multicast short message packets based on one or more second user frames, and obtain the sender ID field based on the outbound multicast short message packets. If the user ID indicated by the sender ID field is the same as the user ID of terminal 100, terminal 100 can discard the outbound multicast short message packet.

[0373] In some embodiments, the multicast group to which the outbound multicast short message belongs is the multicast group of the subscription service, which can be provided by the application server. In this case, execution starts directly from S1006C. The application server can send the text information and multicast ID to the satellite network device 200. It should be noted that the outbound multicast short message may not include the sender ID field.

[0374] In some embodiments, after the satellite short message fusion communication platform 24 or the broadcast multicast center 29 sends the outgoing multicast short message to the satellite center station 23, the outgoing multicast short message can be deleted immediately without waiting for other multicast members in the multicast group to provide confirmation messages for receiving the outgoing multicast short message.

[0375] In some embodiments, the outgoing multicast short message sent by the satellite short message fusion communication platform 24 or the broadcast multicast center 29 to the satellite central station 23 carries a receipt indication field. The receipt indication field is used to instruct other multicast members in the multicast group to reply with an acknowledgment message to the satellite short message fusion communication platform 24 or the broadcast multicast center 29 upon successfully receiving the outgoing multicast short message. Once the satellite short message fusion communication platform 24 or the broadcast multicast center 29 receives acknowledgment messages from all other multicast members in all multicast groups, it can delete the outgoing multicast short message; otherwise, it needs to continue caching the outgoing multicast short message.

[0376] In some embodiments, multicast members in a multicast group can query or download cached unreceived multicast short messages from the satellite short message fusion communication platform 24 or the broadcast multicast center 29.

[0377] Figure 14 This illustration shows a flowchart of a method for querying the number of multicast short messages in a satellite communication system according to an embodiment of this application. This embodiment uses terminal 200 querying the number of multicast messages as an example for explanation. The method for querying the number of multicast short messages in a satellite communication system according to this embodiment may include the following steps:

[0378] S1401, based on user operation, terminal 200 generates a multicast SMS query request message. The multicast SMS query request message allows the user to query the number of multicast SMS messages sent to terminal 200 by a specified multicast group or all multicast groups.

[0379] Terminal 200 is in a satellite network environment, that is, in a scenario where there is no cellular network or wireless local area network, and terminal 200 is not camped on a cellular network. Terminal 200 can query the number of multicast short messages sent to terminal 200 by a specified multicast group or all multicast groups through the satellite network.

[0380] Furthermore, terminal 200 may contain control 1 and control 2. Control 1 can be used to query the number of multicast short messages sent to terminal 200 by a specified multicast group. Control 2 can be used to query the number of multicast short messages sent to terminal 200 by all multicast groups.

[0381] In one possible implementation, the format of the multicast short message query request message can be as shown in Table 10 below.

[0382] Table 10

[0383]

[0384] As shown in Table 10 above, a multicast SMS query request message may include a receipt indication field, a service type field, an encryption indication field, a compression indication field, an application layer authentication code field, a multicast ID field, and a multicast SMS ID field. It is understood that the specific fields included in the multicast SMS query request message and their order are not limited in this embodiment. For example, when an application layer receipt is not required by default, the multicast SMS query request message may not include a receipt indication field.

[0385] The detailed descriptions of each field in the multicast short message query request message shown in Table 10 can be found in Table 11 below.

[0386] Table 11

[0387]

[0388]

[0389] As shown in Table 11, the receipt indication field can be used to indicate whether the receiving device (e.g., satellite network device 200) of the multicast short message query request message needs to reply with an application layer receipt to the terminal 200. The application layer receipt can be used to indicate whether the receiving device has successfully received the multicast short message query request message. The length of the receipt indication field can be 1 bit. When the receipt indication field is a value D1 (e.g., 0), it can be used to indicate that the receiving device of the multicast short message query request message does not need to reply with an application layer receipt to the terminal 200. When the receipt indication field is a value D2 (e.g., 1), it can be used to indicate that the receiving device of the multicast short message query request message needs to reply with an application layer receipt to the terminal 200. It is understood that the embodiments of this application do not limit the length of the receipt indication field or its specific value.

[0390] The service type field can be used to indicate the service type of the multicast short message query request message. In satellite short message communication, the service type of the message can include general message, multicast short message query, multicast short message download, etc. The length of the service type field can be 4 bits. It is understood that the length of the service type field is not limited in this application embodiment. As the number of service types increases, the length of the service type field can become longer. This application embodiment uses a service type field length of 4 bits as an example for illustration. When the service type field is 0000, it indicates that the service type of the application layer message is a general message. When the service type field is 0111, it indicates that the application layer message is a multicast short message query request message, and the multicast short message query request message queries the number of multicast short messages sent by a specified multicast group. When the service type field is 1000, it indicates that the application layer message is a multicast short message query request message, and the multicast short message query request message queries the number of multicast short messages sent by all multicast groups. When the service type field is 1001, it indicates that the application layer message is a multicast SMS download request message, and that the message downloads the number of multicast SMS messages sent by the specified multicast group. When the service type field is 1010, it indicates that the application layer message is a multicast SMS download request message, and that the message downloads the number of multicast SMS messages sent by all multicast groups. The meanings of other values ​​for this service type field are shown in Table 2 and will not be elaborated upon here.

[0391] The encryption indicator field can be used to indicate whether the multicast SMS query request message is encrypted. For example, the encryption indicator field can be 2 bits long. When the encryption indicator field is the value D3 (e.g., 00), it indicates that the multicast SMS query request message is not encrypted. It is understood that this application embodiment does not limit the length of the encryption indicator field or its specific value.

[0392] The compression indicator field can be used to indicate whether the multicast SMS query request message is compressed. For example, the length of the compression indicator field can be 2 bits. When the compression indicator field is the value D4 (e.g., 00), it indicates that the multicast SMS query request message is not compressed. It is understood that this application embodiment does not limit the length of the compression indicator field or its specific value.

[0393] The multicast ID field can be used to indicate the identifier of a specified multicast group that the terminal 200 wants to query or download for the number of multicast SMS messages sent to the terminal 200. The length of the multicast ID field can be 10 bits. It is understood that the length of the multicast ID field is not limited in this embodiment. It should be noted that when the service type field is 0111, the multicast SMS query request message queries the number of multicast SMS messages sent by a specified multicast group, therefore, the multicast SMS query request message includes the multicast ID field; when the service type field is 1000, the multicast SMS query request message queries the number of multicast SMS messages sent by all multicast groups, therefore, the multicast SMS download request message may or may not include the multicast ID field, and this embodiment does not limit this.

[0394] The multicast SMS ID field can be used to indicate the ID of the last multicast SMS message successfully received by the terminal 200 in a series of consecutive multicast SMS messages. For example, if the IDs of the multicast SMS messages successfully received by the terminal 200 before clicking the control for querying multicast SMS messages are 1, 2, 3, and 5, then the multicast SMS ID field would be filled with 3. In some embodiments, when the multicast SMS query request message queries the number of multicast SMS messages sent by all multicast groups, the multicast SMS query request message may not include the multicast SMS ID field.

[0395] S1402, terminal 200 segments the multicast short message query request message into one or more first user frames.

[0396] Specifically, terminal 200 can send multicast short message query request packets to the MDCP layer via the inter-layer interface. Terminal 200 can then segment the multicast short message query request packets into one or more MDCP PDUs at the MDCP layer. Then, terminal 200 sends one or more MDCP PDUs to the SLC layer. At the SLC layer, terminal 200 can segment each MDCP PDU into one or more first user frames. At the SLC layer, terminal 200 can fill in its identifier (e.g., terminal 200's mobile phone number) in the user ID field of the frame header of each first user frame. For more details, please refer to [link to relevant documentation]. Figure 4 The description of the inbound data encapsulation process in the China Satellite Communication System 10 will not be repeated here.

[0397] S1403, terminal 200 sends one or more first user frames to satellite network equipment 200.

[0398] Terminal 200 can send one or more first user frames to satellite network device 200. See here for details. Figure 4 The description of the inbound data encapsulation process in the China Satellite Communication System 10 will not be repeated here.

[0399] S1404, Satellite network equipment 200 assembles one or more first user frames into a multicast short message query request message.

[0400] Specifically, the satellite network device 200 assembles one or more first user frames sent by the terminal 200 into one or more SLC SDUs at the SLC layer. Then, the satellite network device 200 uploads these one or more first user frames to the MDCP layer as one or more MDCP PDUs. Then, the satellite network device 200 can assemble the one or more MDCP PDUs into an MDCP SDU at the MDCP layer. Finally, the satellite network device 200 can upload the MDCP SDU to the APP layer as a multicast short message query request message. (See reference here.) Figure 4 The decapsulation process of incoming data from the satellite communication system will not be described here.

[0401] S1405, Satellite network device 200 generates multicast short message query result message based on multicast short message query request message.

[0402] Satellite network device 200 can query the number of multicast short messages sent to terminal 200 based on multicast short message query request messages. Then, satellite network device 200 can generate multicast short message query result messages from the query results, which are used to indicate the number of multicast short messages sent to terminal 200 by the target multicast group.

[0403] In some embodiments, such as Figure 1 In the architecture diagram of the satellite communication system shown, the satellite network device 200 includes a satellite central station 23 and a satellite short message fusion communication platform 24. The satellite short message fusion communication platform 24 can query the number of multicast short messages sent to the terminal 200 based on a multicast short message query request message. Then, the satellite short message fusion communication platform 24 can generate a multicast short message query result message from the query results. This multicast short message query result message is used to indicate the number of multicast short messages sent to the terminal 200 by the target multicast group.

[0404] In some embodiments, such as Figure 11 or Figure 13 In the architecture diagram of the satellite communication system shown, the satellite network device 200 includes a satellite central station 23, a satellite short message fusion communication platform 24, and a broadcast multicast center 29. The broadcast multicast center 29 can query the number of multicast short messages sent to the terminal 200 based on a multicast short message query request message. Then, the broadcast multicast center 29 can generate a multicast short message query result message from the query results. This multicast short message query result message is used to indicate the number of multicast short messages sent to the terminal 200 by the target multicast group.

[0405] Specifically, in one possible implementation, when a multicast short message query request message indicates a query for the number of multicast short messages sent to terminal 200 by all target multicast groups, satellite center station 23 can send the identifier of terminal 200 (e.g., the mobile phone number of terminal 200, 138xxxxxxxx) parsed from the first user frame to satellite short message fusion communication platform 24 or broadcast multicast center 29. Satellite short message fusion communication platform 24 or broadcast multicast center 29 can then parse the ID of the last multicast short message received by terminal 200 (e.g., "a1") from the multicast short message ID field in the multicast short message query request message, and query the number of multicast short messages sent to terminal 200 by all target multicast groups after the sending time of the multicast short message with ID a1.

[0406] Optionally, in another possible implementation, when the multicast short message query request message indicates a query for the number of multicast short messages sent to terminal 200 by a specified target multicast group, the satellite center station 23 can send the identifier of terminal 200 (e.g., the mobile phone number of terminal 200, 138xxxxxxxx) parsed from the first user frame to the satellite short message fusion communication platform 24 or the broadcast multicast center 29. The satellite short message fusion communication platform 24 or the broadcast multicast center 29 can query the number of multicast short messages sent to terminal 200 by the specified target multicast group after the sending time of the multicast short message with ID a1, based on the identifier of terminal 200, the multicast ID parsed from the multicast ID field in the multicast short message query request message, and the ID of the last multicast short message received by terminal 200 (e.g., "a1") parsed from the multicast short message ID field in the multicast short message query request message.

[0407] It is understood that the satellite short message fusion communication platform 24 or the broadcast multicast center 29 can store the number of multicast short messages sent to the terminal 200 by different multicast groups. For example, the format of the number of multicast short messages sent to the terminal 200 by different multicast groups stored in the satellite short message fusion communication platform 24 or the broadcast multicast center 29 can be as shown in Table 12 below.

[0408] Table 12

[0409]

[0410] As shown in Table 12, the satellite short message fusion communication platform 24 or the broadcast multicast center 29 can store multicast IDs, the sender IDs of the multicast short messages received by the multicast IDs, and the sending time of the multicast short messages. For example, the multicast group with multicast ID 1 is the first multicast group of terminal 200, and the first multicast group stores the sender IDs and sending time of two multicast short messages. The satellite short message fusion communication platform 24 or the broadcast multicast center 29 also stores multicast short message IDs. These multicast short message IDs are numbered according to the chronological order of the sending time of all multicast short messages received by terminal 200.

[0411] In some scenarios, as shown in Table 12, terminal 200 receives a total of 4 multicast short messages. If the multicast short message successfully received by terminal 200 last time was sent by "13xxxxxxxx0" in multicast ID 1, and the multicast short message ID is 1, then when terminal 200 queries the number of multicast short messages sent by multicast ID 1, the satellite network device 200 will reply with a multicast short message count of 1. If the multicast short message successfully received by terminal 200 last time was sent by "13xxxxxxxx0" in multicast ID 1, and the multicast short message ID is 1, then when terminal 200 queries the number of multicast short messages sent by all multicast groups, the satellite network device 200 will reply with a multicast short message count of 3.

[0412] Optionally, the multicast SMS IDs can be numbered according to the chronological order of the sending time of the multicast SMS messages received under different multicast IDs in terminal 200. For example, as shown in Table 12, the multicast group indicated by multicast ID 1 receives two multicast SMS messages, where the multicast SMS message sent by sender "13xxxxxxxx0" has a multicast SMS ID of 1, and the multicast SMS message sent by sender "13xxxxxxxx1" has a multicast SMS ID of 2; the multicast group indicated by multicast ID 2 receives two multicast SMS messages, where the multicast SMS message sent by sender "158xxxxxxx0" has a multicast SMS ID of 1, and the multicast SMS message sent by sender "158xxxxxxx1" has a multicast SMS ID of 2.

[0413] Optionally, the satellite short message fusion communication platform 24 or the broadcast multicast center 29 may also store the specific content of the multicast short messages. It is understood that Table 12 above is merely an example, and the format for storing multicast short messages is not limited in this application embodiment.

[0414] In one implementation, the format of the multicast short message query result message can be as shown in Table 13 below.

[0415] Table 13

[0416]

[0417] As shown in Table 13 above, the multicast short message query result message may include a message type indicator field, an encryption indicator field, a compression indicator field, an application layer authentication code field, a multicast group number field, a multicast ID field, and a multicast short message number field. It is understood that the specific fields included in the multicast short message query result message and their order are not limited in this embodiment. For example, if the satellite network device 200 does not encrypt the multicast short message query result message, the encryption indicator field may not be included in the multicast short message query result message.

[0418] The detailed descriptions of each field in the multicast short message query result message shown in Table 13 are illustrated in Table 14 below. Table 14 provides an example of the length and detailed description of each field in Table 13.

[0419] Table 14

[0420]

[0421] As shown in Table 14, the encryption indicator field can be used to indicate whether the multicast SMS query result message is encrypted. For example, the length of the encryption indicator field can be 2 bits. When the encryption indicator field is the value M1 (e.g., 00), it indicates that the multicast SMS query result message is not encrypted. It is understood that this application embodiment does not limit the length of the encryption indicator field or its specific value.

[0422] As shown in Table 14, the compression indicator field can be used to indicate whether the multicast SMS query result message is compressed. For example, the length of the compression indicator field can be 2 bits. When the compression indicator field is the value M2 (e.g., 00), it indicates that the multicast SMS query result message is not compressed. It is understood that this application embodiment does not limit the length of the compression indicator field or its specific value.

[0423] As shown in Table 14, the application layer authentication code field can be used for application layer authentication. For example, the length of this application layer authentication code field can be 16 bits. It is understood that the embodiments of this application do not limit the length of this application layer authentication code field.

[0424] As shown in Table 14, the multicast group quantity field can be used to indicate the total number of multicast groups in terminal 200. Optionally, the multicast group quantity field can also be used to indicate the number of times the multicast ID field and the multicast SMS quantity field are cycled in the multicast SMS query result message. For example, the length of the multicast group quantity field can be 4 bits. It is understood that the embodiments of this application do not limit the length of the multicast group quantity field.

[0425] As shown in Table 14, the multicast ID field is used to indicate the ID of the target multicast group. For example, the length of this multicast ID field can be 10 bits. It is understood that the embodiments of this application do not limit the length of the multicast ID field.

[0426] As shown in Table 14, the multicast message quantity field is used to indicate the number of multicast messages sent by the target multicast group. For example, this multicast message quantity field can be 4 bits. It is understood that the length of the multicast message quantity field is not limited in this embodiment of the application.

[0427] It should be noted that when the number of multicast groups indicated by the multicast group quantity field is N, the multicast ID field and the multicast SMS quantity field will appear multiple times in the multicast SMS query result message.

[0428] In one possible implementation, when terminal 200 queries the number of multicast short messages sent by all target multicast groups, the satellite short message fusion communication platform 24 or the broadcast multicast center 29 can generate different multicast short message query result messages for different target multicast groups. Therefore, the multicast short message query result message may not include a multicast group count field.

[0429] In one possible implementation, the multicast short message query result message may not include the multicast group quantity field and the multicast ID field. In this case, the multicast short message quantity field is used to indicate the total number of multicast short messages in all multicast groups in terminal 200.

[0430] S1406, Satellite network equipment 200 segments the multicast short message query result message into one or more second user frames.

[0431] The process by which satellite network equipment 200 segments multicast short message query result messages into one or more second user frames can be found in [reference]. Figure 6 The specific details will not be repeated here.

[0432] S1407, the satellite network device 200 sends one or more second user frames to the terminal 200.

[0433] The process by which satellite network equipment 200 sends one or more second user frames to terminal 200 can be referred to Figure 6 The specific details will not be repeated here.

[0434] S1408, Terminal 200 receives one or more second user frames.

[0435] Terminal 200 can receive one or more second user frames. For details on the reception process, please refer to [reference needed]. Figure 7 The description of the illustrated embodiments will not be repeated here.

[0436] In one possible implementation, after the terminal 200 has received one or more second user frames, it replies to the satellite network device 200 that it has received one or more second user frames.

[0437] Furthermore, terminal 200 can parse the user ID field in the frame header of each second user frame at the SLC layer. If the user ID parsed by terminal 200 from the user ID field is the same as the identifier of terminal 200, then terminal 200 uploads the one or more second user frames to the MDCP layer for further parsing. If the user ID parsed by terminal 200 from the user ID field is different from the identifier of terminal 200, then terminal 200 can determine that the second user frame was not sent to terminal 200, and terminal 200 can discard the second user frame.

[0438] S1409, Terminal 200 assembles one or more second user frames into a multicast short message query result message.

[0439] Specifically, terminal 200 can assemble one or more second user frames into one or more SLCSDUs at the SLC layer. Then, terminal 200 uploads the one or more second user frames to the MDCP layer as one or more MDCPPDUs of the MDCP layer. Then, terminal 200 can assemble one or more MDCP PDUs into an MDCP SDU at the MDCP layer. Then, terminal 200 can upload the MDCP SDU to the APP layer as a multicast short message query result message. (See reference here.) Figure 7 The decapsulation process of outgoing data from the satellite communication system will not be described here.

[0440] S1410, Terminal 200 parses the number of multicast short messages sent to Terminal 200 by the target multicast group based on the multicast short message query result message.

[0441] Terminal 200 can obtain the multicast group number field, multicast ID field, and multicast short message number field based on the multicast short message query result message at the APP layer, and know the number of multicast short messages sent to terminal 200 by the target multicast group from the multicast short message number field.

[0442] S1411, Terminal 200 displays the number of multicast short messages sent to Terminal 200 by the target multicast group.

[0443] Terminal 200 can display the number of multicast SMS messages sent to terminal 200 by the target multicast group. Terminal 200 can also prompt the user about the number of SMS messages sent to terminal 200 by the target multicast group in other ways, such as by the terminal 200 verbally announcing the number of messages sent to terminal 200 by the target multicast group. This embodiment of the application does not limit this.

[0444] Thus, by using the method for querying the number of multicast short messages in a satellite communication system provided in this application embodiment, the terminal 200 can query the number of multicast short messages sent to the terminal 200 by the target group even when it is on a satellite network and not camped on a cellular network.

[0445] Figure 15 This illustration shows a flowchart of a method for downloading multicast short messages in a satellite communication system according to an embodiment of this application. This embodiment uses terminal 200 downloading multicast messages as an example for explanation. Downloading multicast short messages in a satellite communication system according to this embodiment may include the following steps:

[0446] S1501, based on user operation, terminal 200 generates a multicast short message download request message. The multicast short message download request message is used to download the content of multicast short messages sent to terminal 200 by one or more target multicast groups.

[0447] Terminal 200 is in a satellite network environment, meaning it is in a scenario without cellular or wireless local area networks. Terminal 200 is not registered with a cellular network, and its satellite communication module is activated. Terminal 200 can communicate with satellite network device 200 through this module. Terminal 200 can also obtain the content of multicast short messages sent to it by one or more target multicast groups via the satellite network.

[0448] Furthermore, terminal 200 may contain controls 3 and 4. Control 3 can be used to request the download of multicast short messages sent to terminal 200 by a specified target multicast group. Control 4 can be used to request the download of multicast short messages sent to terminal 200 by all multicast groups.

[0449] In one possible implementation, the format of the multicast short message download request message can be as shown in Table 15 below.

[0450] Table 15

[0451]

[0452]

[0453] The specific meanings of the fields in Table 15 can be found in the description in S1401, and will not be repeated here. It should be noted that in the multicast SMS download request message, when the service type indicator field is 1001, it indicates that the multicast SMS download request message requests to download multicast SMS messages sent to terminal 200 by the specified multicast group; when the service type indicator field is 1010, it indicates that the multicast SMS download request message requests to download multicast SMS messages sent to terminal 200 by all multicast groups. In this case, the multicast ID field may not be included in the multicast SMS download request message.

[0454] S1502, Terminal 200 segments the multicast short message download request message into one or more first user frames.

[0455] Specifically, terminal 200 can send multicast short message download request packets to the MDCP layer via the inter-layer interface. Terminal 200 can then segment the multicast short message download request packets into one or more MDCP PDUs at the MDCP layer. Then, terminal 200 sends the one or more MDCP PDUs to the SLC layer. Terminal 200 can then segment each MDCP PDU into one or more first user frames at the SLC layer. At the SLC layer, terminal 200 can fill in its identifier (e.g., terminal 200's mobile phone number) in the user ID field of the frame header of each first user frame. For more details, please refer to [link to relevant documentation]. Figure 4 The description of the inbound data encapsulation process in the China Satellite Communication System 10 will not be repeated here.

[0456] S1503, terminal 200 sends one or more first user frames to satellite network equipment 200.

[0457] Terminal 200 can send one or more first user frames to satellite network device 200. See here for details. Figure 4 The description of the inbound data encapsulation process in the China Satellite Communication System 10 will not be repeated here.

[0458] S1504, Satellite network equipment 200 assembles one or more first user frames into a multicast short message download request message.

[0459] Specifically, satellite network device 200 assembles one or more first user frames sent by terminal 200 into one or more SLC SDUs at the SLC layer. Then, satellite network device 200 uploads these one or more first user frames to the MDCP layer as one or more MDCP PDUs. Then, satellite network device 200 can assemble the one or more MDCP PDUs into an MDCP SDU at the MDCP layer. Finally, satellite network device 200 can upload the MDCP SDU to the APP layer as a multicast short message download request message. (See reference here.) Figure 4 The decapsulation process of incoming data from the satellite communication system will not be described here.

[0460] S1505, the satellite network device 200 generates an outbound multicast short message based on the multicast short message download request message. The outbound multicast short message is used to indicate the content of the multicast short message sent by the target multicast group to the terminal 200.

[0461] Satellite network device 200 can query multicast short messages sent to terminal 200 based on multicast short message download request messages. Then, satellite network device 200 can generate outbound multicast short message messages from the queried multicast short messages. These outbound multicast short message messages are used to indicate the content of the multicast short messages sent to terminal 200 by the target multicast group.

[0462] In some embodiments, such as Figure 1 In the architecture diagram of the satellite communication system shown, the satellite network device 200 includes a satellite central station 23 and a satellite short message fusion communication platform 24. The satellite short message fusion communication platform 24 can query multicast short messages sent to the terminal 200 based on multicast short message download request messages. Then, the satellite short message fusion communication platform 24 can generate outbound multicast short message messages from the queried multicast short messages. These outbound multicast short message messages are used to indicate the content of the multicast short messages sent by the target multicast group to the terminal 200.

[0463] In some embodiments, such as Figure 11 or Figure 13 In the architecture diagram of the satellite communication system shown, the satellite network device 200 includes a satellite central station 23, a satellite short message fusion communication platform 24, and a broadcast multicast center 29. The broadcast multicast center 29 can query multicast short messages sent to the terminal 200 based on multicast short message download request messages. Then, the broadcast multicast center 29 can generate outbound multicast short message messages from the queried multicast short messages. These outbound multicast short message messages are used to indicate the content of the multicast short messages sent by the target multicast group to the terminal 200.

[0464] Specifically, in one possible implementation, when a multicast short message download request message instructs the download of the content of all multicast short messages sent to terminal 200 by all target multicast groups, satellite center station 23 can send the identifier of terminal 200 (e.g., the mobile phone number of terminal 200, 138xxxxxxxx) parsed from the first user frame to satellite short message fusion communication platform 24 or broadcast multicast center 29. Satellite short message fusion communication platform 24 or broadcast multicast center 29 can then parse the ID of the last multicast short message received by terminal 200 (e.g., "a1") from the multicast short message ID field in the multicast short message download request message to query the content of all multicast short messages sent to terminal 200 by all target multicast groups after the sending time of the multicast short message with ID a1.

[0465] Optionally, in another possible implementation, when the multicast short message download request message indicates a request to download the content of a multicast short message sent to terminal 200 by a specified target multicast group, the satellite center station 23 can send the identifier of terminal 200 (e.g., the mobile phone number of terminal 200, 138xxxxxxxx) parsed from the first user frame to the satellite short message fusion communication platform 24 or the broadcast multicast center 29. The satellite short message fusion communication platform 24 or the broadcast multicast center 29 can query the content of the multicast short message sent to terminal 200 by the specified target multicast group after the sending time of the multicast short message with ID a1, based on the identifier of terminal 200, the multicast ID parsed from the multicast ID field in the multicast short message download request message, and the ID of the last multicast short message received by terminal 200 (e.g., "a1") parsed from the multicast short message ID field in the multicast short message download request message.

[0466] It is understandable that the satellite short message fusion communication platform 24 or the broadcast multicast center 29 can store the content of multicast short messages sent to the terminal 200 by different multicast groups. The specific storage method for the content of the multicast short messages can be found in the description of S1405, and will not be repeated here.

[0467] Once the satellite short message fusion communication platform 24 or the broadcast multicast center 29 queries the content of the multicast short message sent by the target multicast group to the terminal 200 in the multicast short message download request message, the satellite short message fusion communication platform 24 or the broadcast multicast center 29 can generate an outbound multicast short message based on the content of the multicast short message.

[0468] In one possible implementation, the format of the outbound multicast short message is shown in Table 5. Specific descriptions of each field in the outbound multicast short message can be found in the description of S1006, and will not be repeated here. It is understood that in this embodiment, the outbound multicast short message is sent to a specific target terminal. For example, this outbound multicast short message is sent to terminal 200.

[0469] S1506, Satellite Network Equipment 200 segments outgoing multicast short message messages into one or more second user frames.

[0470] The process by which satellite network equipment 200 segments outgoing multicast short message packets into one or more second user frames can be referenced. Figure 6 The specific details will not be repeated here.

[0471] S1507, the satellite network equipment 200 sends one or more second user frames to the terminal 200.

[0472] The process by which satellite network equipment 200 sends one or more second user frames to terminal 200 can be referred to Figure 6 The specific details will not be repeated here.

[0473] S1508, Terminal 200 receives one or more second user frames.

[0474] Terminal 200 can receive one or more second user frames. For details on the reception process, please refer to [reference needed]. Figure 7 The description of the illustrated embodiments will not be repeated here.

[0475] In one possible implementation, after the terminal 200 has received one or more second user frames, it replies to the satellite network device 200 that it has received one or more second user frames.

[0476] Furthermore, terminal 200 can parse the user ID field in the frame header of each second user frame at the SLC layer. If the user ID parsed by terminal 200 from the user ID field is the same as the identifier of terminal 200, then terminal 200 uploads the one or more second user frames to the MDCP layer for further parsing. If the user ID parsed by terminal 200 from the user ID field is different from the identifier of terminal 200, then terminal 200 can determine that the second user frame was not sent to terminal 200, and terminal 200 can discard the second user frame.

[0477] S1509, Terminal 200 assembles one or more second user frames into an outbound multicast short message.

[0478] Specifically, terminal 200 can assemble one or more second user frames into one or more SLCSDUs at the SLC layer. Then, terminal 200 uploads the one or more second user frames to the MDCP layer as one or more MDCPPDUs of the MDCP layer. Then, terminal 200 can assemble one or more MDCP PDUs into an MDCP SDU at the MDCP layer. Then, terminal 200 can upload the MDCP SDU to the APP layer as an outbound multicast short message. (See reference here.) Figure 7 The decapsulation process of outgoing data from the satellite communication system will not be described here.

[0479] S1510, Terminal 200 parses the content of the multicast short message sent to Terminal 200 by the target multicast group based on the outbound multicast short message message.

[0480] Terminal 200 can obtain the multicast ID field, sender ID field, and multicast message content field, etc., based on the outbound multicast short message message at the APP layer, thereby determining the multicast group and sender corresponding to the multicast short message.

[0481] S1511, Terminal 200 displays the content of the multicast short message sent to Terminal 200 by the target multicast group.

[0482] Terminal 200 can display the content of multicast short messages sent to terminal 200 by the target multicast group on the display screen. Terminal 200 can also prompt the user with the content of short messages sent to terminal 200 by the target multicast group in other ways, such as terminal 200 voice-reading the content of the message sent to terminal 200 by the target multicast group. This application embodiment does not limit this.

[0483] In some embodiments, the multicast short message download completion indication field in the outbound multicast short message message indicates that there are still multicast short messages to be sent to the terminal 200. The terminal 200 can display a notification message to the user, which is used to prompt the user whether to continue downloading subsequent multicast short messages.

[0484] Optionally, before downloading multicast SMS messages, the user of terminal 200 can first query the number of multicast SMS messages sent to terminal 200 by the target multicast group. After the satellite network device 200 sends the number of multicast SMS messages sent to terminal 200 by the target multicast group, terminal 200 can select the multicast SMS messages it wants to download and begin downloading them.

[0485] Thus, through the method for downloading multicast short messages in a satellite communication system provided in this application embodiment, the terminal 200 can download the number of multicast short messages sent to the terminal 200 by the target group even when it is on a satellite network and not camped on a cellular network.

[0486] The foregoing details the method provided in this application. In order to facilitate better implementation of the above-described solutions in the embodiments of this application, the embodiments of this application also provide corresponding devices or equipment.

[0487] This application embodiment can divide the terminal 100, terminal 200, and satellite network device 200 into functional modules according to the above method example. For example, each function can be divided into its own functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division; other division methods may be used in actual implementation.

[0488] The following will combine Figures 16 to 19 The communication device of the present application embodiment is described in detail.

[0489] In the case of using integrated units, see Figure 16 , Figure 16This is a schematic diagram of the structure of the communication device 1600 provided in an embodiment of this application. The communication device 1600 can be the terminal 100 or terminal 200 in the above embodiments. Optionally, the communication device 1600 can be a chip / chip system, such as a satellite communication chip. Figure 16 As shown, the communication device 1600 may include a transceiver unit 1610 and a processing unit 1620.

[0490] In one design, the transceiver unit 1610 can be used to send inbound multicast short message messages to the satellite network device 200;

[0491] Optionally, the transceiver unit 1610 can also be used to receive outbound multicast short message messages.

[0492] The processing unit 1620 can be used to send inbound multicast short message packets to the MDCP layer, and can segment the inbound multicast short message packets into one or more MDCP PDUs at the MDCP layer.

[0493] Optionally, the processing unit 1620 can also be used to segment inbound multicast short message packets into one or more MDCPPDUs, send one or more MDCP PDUs to the SLC layer, and segment each MDCP PDU into one or more first user frames at the SLC layer.

[0494] Optionally, the processing unit 1620 can also be used to assemble one or more first user frames into one or more SLCSDUs, send one or more SLC SDUs to the MDCP layer, assemble one or more MDCP PDUs into MDCP SDUs at the MDCP layer, and send the MDCP SDUs to the APP layer as outbound multicast short message packets.

[0495] In one design, the transceiver unit 1610 can be used to send multicast short message query request messages to the satellite network device 200;

[0496] Optionally, the transceiver unit 1610 can also be used to receive multicast short message query result messages.

[0497] Optionally, the processing unit 1620 can also be used to segment the multicast short message query request message into one or more MDCP PDUs, send one or more MDCP PDUs to the SLC layer, and segment each MDCP PDU into one or more first user frames at the SLC layer.

[0498] Optionally, the processing unit 1620 can also be used to assemble one or more first user frames into one or more SLCSDUs, send one or more SLC SDUs to the MDCP layer, assemble one or more MDCP PDUs into an MDCP SDU at the MDCP layer, and send the MDCP SDU to the APP layer as a multicast short message query result message.

[0499] In one design, the transceiver unit 1610 can be used to send a multicast short message download request message to the satellite network device 200;

[0500] Optionally, the transceiver unit 1610 can also be used to receive outbound multicast short message messages.

[0501] Optionally, the processing unit 1620 can also be used to segment the multicast short message download request message into one or more MDCP PDUs, send one or more MDCP PDUs to the SLC layer, and segment each MDCP PDU into one or more first user frames at the SLC layer.

[0502] Optionally, the processing unit 1620 can also be used to assemble one or more first user frames into one or more SLCSDUs, send one or more SLC SDUs to the MDCP layer, assemble one or more MDCP PDUs into MDCP SDUs at the MDCP layer, and send the MDCP SDUs to the APP layer as outbound multicast short message packets.

[0503] Optionally, the transceiver unit 1610 can also be used to perform the above-mentioned tasks. Figure 10A , Figure 10B , Figure 12A or Figure 12B The sending and receiving functional steps performed by terminal 100 or terminal 200 in the method embodiment shown can also be used in the above-mentioned... Figure 14 or Figure 15 The method embodiment shown illustrates the functional steps related to sending and receiving performed by terminal 200.

[0504] Optionally, the processing unit 1620 can also be used to perform the above. Figure 10A , Figure 10B , Figure 12A or Figure 12B The protocol parsing, encapsulation, and calculation determination steps performed by terminal 100 or terminal 200 in the method embodiment shown can also be used to perform the above-mentioned functions. Figure 14 or Figure 15 The method embodiment shown illustrates the functional steps performed by terminal 200 related to protocol parsing and encapsulation, as well as computational determination.

[0505] It should be understood that the communication device 1600 in this design can execute the method steps executed by the terminal 100 or the terminal 200 in the aforementioned embodiments, and for the sake of brevity, it will not be described again here.

[0506] In the case of using integrated units, see Figure 17 , Figure 17 This is a schematic diagram of the structure of the communication device 1700 provided in the embodiments of this application. The communication device 1700 can be the satellite network device 200 in the above embodiments. Optionally, the communication device 1700 can be a specific network element in the satellite network device 200, such as one or a combination of multiple network elements from the satellite ground transceiver station 22, the satellite central station 23, and the satellite short message fusion communication platform 24. Figure 17 As shown, the communication device 1700 may include a transceiver unit 1710 and a processing unit 1720.

[0507] In one design, the transceiver unit 1710 can be used to receive inbound multicast short message messages.

[0508] Optionally, the transceiver unit 1710 can also be used to send outbound multicast short message messages.

[0509] The processing unit 1720 can also be used to assemble one or more first user frames into one or more SLC SDUs at the SLC layer, upload one or more SLC SDUs to the MDCP layer as one or more MDCP PDUs of the MDCP layer; assemble one or more MDCP PDUs into MDCP SDUs at the MDCP layer; and then upload the MDCP SDUs to the APP layer as inbound multicast short message messages.

[0510] Optionally, the processing unit 1720 can also be used to segment outgoing multicast short message packets into one or more MDCPPDUs, send one or more MDCP PDUs to the SLC layer, and segment each MDCP PDU into one or more second user frames at the SLC layer.

[0511] In one design, the transceiver unit 1710 can be used to receive multicast short message query request messages.

[0512] Optionally, the transceiver unit 1710 can also be used to send multicast short message result messages.

[0513] The processing unit 1720 can also be used to assemble one or more first user frames into one or more SLC SDUs at the SLC layer, upload one or more SLC SDUs to the MDCP layer as one or more MDCP PDUs of the MDCP layer; assemble one or more MDCP PDUs into MDCP SDUs at the MDCP layer; and then upload the MDCP SDUs to the APP layer as multicast short message query request messages.

[0514] Optionally, the processing unit 1720 can also be used to segment the multicast short message result message into one or more MDCPPDUs, send one or more MDCP PDUs to the SLC layer, and segment each MDCP PDU into one or more second user frames at the SLC layer.

[0515] In one design, the transceiver unit 1710 can be used to receive multicast short message download request messages.

[0516] Optionally, the transceiver unit 1710 can also be used to send outbound multicast short message messages.

[0517] The processing unit 1720 can also be used to assemble one or more first user frames into one or more SLC SDUs at the SLC layer, upload one or more SLC SDUs to the MDCP layer as one or more MDCP PDUs of the MDCP layer; assemble one or more MDCP PDUs into MDCP SDUs at the MDCP layer; and then upload the MDCP SDUs to the APP layer as multicast short message download request messages.

[0518] Optionally, the processing unit 1720 can also be used to segment outgoing multicast short message packets into one or more MDCPPDUs, send one or more MDCP PDUs to the SLC layer, and segment each MDCP PDU into one or more second user frames at the SLC layer.

[0519] Optionally, the transceiver unit 1710 can also be used to perform the above-mentioned tasks. Figure 10A , Figure 10B , Figure 12A , Figure 12B , Figure 14 or Figure 15 The satellite network device 200 in the illustrated method embodiment performs the functional steps related to sending and receiving.

[0520] Optionally, the processing unit 1720 can also be used to perform the above. Figure 10A , Figure 10B , Figure 12A , Figure 12B , Figure 14 or Figure 15The method embodiment shown illustrates the functional steps performed by the satellite network device 200 related to protocol parsing, encapsulation, and computational determination.

[0521] It should be understood that the communication device 1700 in this design can perform the method steps executed by the satellite network device 200 in the aforementioned embodiment, and for the sake of brevity, it will not be described again here.

[0522] The terminal 100, terminal 200, and satellite network device 200 of this application have been described above. It should be understood that any device possessing the above-described features... Figure 16 Any product of any form that possesses the functions of the aforementioned terminal 100 or terminal 200, but whichever possesses the above-mentioned... Figure 17 Any form of product that incorporates the functionality of the satellite network equipment 200 falls within the protection scope of the embodiments of this application.

[0523] As a possible product form, the terminal 100 or terminal 200 described in the embodiments of this application can be implemented by a general bus architecture.

[0524] See Figure 18 , Figure 18 This is a schematic diagram of the structure of the communication device 1800 provided in an embodiment of this application. The communication device 1800 can be terminal 100 or terminal 200, or a device thereof. Figure 18 As shown, the communication device 1800 includes a processor 1801 and a transceiver 1802 internally connected and communicating with the processor. The processor 1801 can be a general-purpose processor or a dedicated processor, such as a baseband processor or a central processing unit (CPU) for satellite communication. The baseband processor can process satellite communication protocols and data, while the CPU can control the communication device (e.g., baseband chip, terminal, terminal chip), execute computer programs, and process data from the computer programs. The transceiver 1802, also known as a transceiver unit, transceiver, or transceiver circuit, is used to implement transceiver functions. The transceiver 1802 may include a receiver and a transmitter. The receiver, also known as a receiver circuit, is used to implement a receiving function; the transmitter, also known as a transmitter or transmitting circuit, is used to implement a transmitting function. Optionally, the communication device 1800 may also include an antenna 1803 and / or a radio frequency unit (not shown in the figure). The antenna 1803 and / or radio frequency unit may be located inside the communication device 1800 or separate from the communication device 1800, that is, the antenna 1803 and / or radio frequency unit may be deployed remotely or in a distributed manner.

[0525] Optionally, the communication device 1800 may include one or more memories 1804, which may store instructions, which may be computer programs, that can be executed on the communication device 1800 to cause the communication device 1800 to perform the methods described in the above method embodiments. Optionally, the memory 1804 may also store data. The communication device 1800 and the memory 1804 may be provided separately or integrated together.

[0526] The processor 1801, transceiver 1802, and memory 1804 can be connected via a communication bus.

[0527] In one design, the communication device 1800 can be used to perform the functions of the terminal 100 or terminal 200 in the foregoing embodiments; the processor 1801 can be used to perform the aforementioned... Figure 10A , Figure 10B , Figure 12A , Figure 12B , Figure 14 as well as Figure 15 In the illustrated embodiments, terminal 100 or terminal 200 performs functional steps related to protocol parsing and encapsulation, as well as calculations and / or other processes used in the techniques described herein; transceiver 1502 can be used to perform the above-mentioned... Figure 10A , Figure 10B , Figure 12A , Figure 12B , Figure 14 as well as Figure 15 The embodiments shown include the functional steps related to protocol parsing and encapsulation, as well as calculation and determination, and / or other processes used in the technology described herein, performed by terminal 100 or terminal 200.

[0528] In any of the above designs, the processor 1801 may include a transceiver for implementing receive and transmit functions. For example, the transceiver may be a transceiver circuit, an interface, or an interface circuit. The transceiver circuit, interface, or interface circuit for implementing receive and transmit functions may be separate or integrated. The aforementioned transceiver circuit, interface, or interface circuit may be used for reading and writing code / data, or it may be used for transmitting or relaying signals.

[0529] In any of the above designs, the processor 1801 may store instructions, which may be computer programs. These computer programs, running on the processor 1801, cause the communication device 1800 to execute the method steps executed by the terminal 100 in the above method embodiments. The computer program may be embedded in the processor 1801; in this case, the processor 1801 may be implemented in hardware.

[0530] In one implementation, the communication device 1800 may include circuitry capable of performing the functions of transmitting, receiving, or communicating as described in the foregoing method embodiments. The processor and transceiver described in this application can be implemented on integrated circuits (ICs), analog ICs, radio frequency integrated circuits (RFICs), mixed-signal ICs, application-specific integrated circuits (ASICs), printed circuit boards (PCBs), electronic devices, etc. The processor and transceiver can also be manufactured using various IC process technologies, such as complementary metal oxide semiconductors (CMOS), n-metal-oxide-semiconductor (NMOS), positive channel metal oxide semiconductors (PMOS), bipolar junction transistors (BJTs), bipolar CMOS (BiCMOS), silicon germanium (SiGe), gallium arsenide (GaAs), etc.

[0531] The scope of the communication device described in this application is not limited thereto, and the structure of the communication device may vary. Figure 18 The communication device 1800 may be a standalone device or part of a larger device. For example, the communication device 1800 may be:

[0532] (1) Independent integrated circuit IC, or chip, or chip system or subsystem;

[0533] (2) A collection of one or more ICs, optionally including storage components for storing data and computer programs;

[0534] (3) ASIC, such as modem;

[0535] (4) Modules that can be embedded in other devices;

[0536] (5) Receivers, terminals, smart terminals, cellular phones, wireless devices, handheld devices, mobile units, vehicle-mounted devices, network devices, cloud devices, artificial intelligence devices, etc.

[0537] (6) Others, etc.

[0538] As a possible product form, any network element in the satellite network device 200 described in this application embodiment (e.g., satellite ground transceiver station 22, satellite central station 23, and satellite short message fusion communication platform 24) can be implemented by a general bus architecture.

[0539] See Figure 19 , Figure 19 This is a schematic diagram of the structure of the communication device 1900 provided in an embodiment of this application. The communication device 1900 may be a satellite network device 200, or a device therein. Figure 19 As shown, the communication device 1900 includes a processor 1901 and a transceiver 1902 internally connected and communicating with the processor. The processor 1901 can be a general-purpose processor or a dedicated processor, such as a baseband processor or a central processing unit (CPU) for satellite communication. The baseband processor can process satellite communication protocols and data, while the CPU can control the communication device (e.g., a baseband chip), execute computer programs, and process data from those programs. The transceiver 1902, also known as a transceiver unit, transceiver, or transceiver circuit, is used to implement transceiver functions. The transceiver 1902 may include a receiver and a transmitter. The receiver, also known as a receiver circuit, is used to implement a receiving function; the transmitter, also known as a transmitter or transmitting circuit, is used to implement a transmitting function. Optionally, the communication device 1900 may also include an antenna 1903 and / or a radio frequency unit (not shown in the figure). The antenna 1903 and / or radio frequency unit may be located inside the communication device 1900 or separate from the communication device 1900, that is, the antenna 1903 and / or radio frequency unit may be deployed remotely or in a distributed manner.

[0540] Optionally, the communication device 1900 may include one or more memories 1904, which may store instructions, which may be computer programs, that can be executed on the communication device 1900 to cause the communication device 1900 to perform the methods described in the above method embodiments. Optionally, the memory 1904 may also store data. The communication device 1900 and the memory 1904 may be provided separately or integrated together.

[0541] The processor 1901, transceiver 1902, and memory 1904 can be connected via a communication bus.

[0542] In one design, the communication device 1900 can be used to perform the functions of the satellite network device 200 in the aforementioned embodiments: the processor 1901 can be used to perform the above-mentioned functions. Figure 10A , Figure 10B , Figure 12A , Figure 12B , Figure 14 as well as Figure 15 The satellite network device 200 in the illustrated embodiment performs the relevant protocol parsing, encapsulation, and computational determination functional steps and / or other processes used in the technology described herein; the transceiver 1902 can be used to perform the above. Figure 10A , Figure 10B , Figure 12A , Figure 12B , Figure 14 as well as Figure 15 The satellite network device 200 in the illustrated embodiment performs functional steps related to protocol parsing and encapsulation, as well as computational determination, and / or other processes used in the techniques described herein.

[0543] In any of the above designs, the processor 1901 may include a transceiver for implementing receive and transmit functions. For example, the transceiver may be a transceiver circuit, an interface, or an interface circuit. The transceiver circuit, interface, or interface circuit for implementing receive and transmit functions may be separate or integrated. The aforementioned transceiver circuit, interface, or interface circuit may be used for reading and writing code / data, or it may be used for transmitting or relaying signals.

[0544] In any of the above designs, the processor 1901 may store instructions, which may be computer programs. These computer programs, running on the processor 1901, cause the communication device 1900 to perform the method steps executed by the satellite network device 200 in the above method embodiments. The computer program may be embedded in the processor 1901; in this case, the processor 1901 may be implemented in hardware.

[0545] This application also provides a computer-readable storage medium storing computer program code, which, when executed by the processor, causes the communication device to perform the method in any of the foregoing embodiments.

[0546] This application also provides a computer program product that, when run on a computer, causes the computer to perform the methods in any of the foregoing embodiments.

[0547] This application also provides a communication device, which can exist in the form of a chip. The device includes a processor and an interface circuit. The processor is used to communicate with other devices through a receiving circuit, so that the device can execute the method in any of the foregoing embodiments.

[0548] This application also provides a satellite communication system, including a terminal 100 and / or a terminal 200 and a satellite network device 200, which can perform the methods in any of the foregoing embodiments.

[0549] This application fully describes the short message communication function in a satellite communication system. It is understood that the BeiDou satellite communication system supports the short message communication function, and the method described in this application is applicable to the BeiDou satellite communication system.

[0550] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0551] As used in the above embodiments, depending on the context, the term "when..." can be interpreted as meaning "if...", "after...", "in response to determining...", or "in response to detecting...". Similarly, depending on the context, the phrase "when determining..." or "if (the stated condition or event) is interpreted as meaning "if determining...", "in response to determining...", "when (the stated condition or event) is detected", or "in response to detecting (the stated condition or event)".

[0552] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state drive), etc.

[0553] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM or random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A method for transmitting multicast short messages in a satellite communication system, characterized in that, The method is applied to a first terminal, and the method includes: The first terminal sends an inbound multicast short message to the satellite network device. The inbound multicast short message includes a first field and a second field. The first field indicates that the multicast ID of the multicast group corresponding to the inbound multicast short message is a first multicast ID, and the second field indicates that the information content in the inbound multicast short message is a first information content. The inbound multicast short message also includes a third field, which indicates that the service type of the inbound multicast short message is a general message service type. The first terminal sends an inbound multicast short message to the satellite network device, including: the first terminal sends one or more first user frames to the satellite network device, wherein the one or more first user frames include a fourth field, the fourth field being used to indicate that the frame type of the one or more first user frames is a multicast short message frame type.

2. The method according to claim 1, characterized in that, The method further includes: The first terminal receives a first outbound multicast short message sent by the satellite network device. The first outbound multicast short message includes a fifth field and a sixth field. The fifth field is used to indicate that the sender ID of the first outbound multicast short message is the user ID of the second terminal, and the sixth field is used to indicate that the information content in the first outbound multicast short message is the second information content. The first terminal and the second terminal belong to the first multicast group, and the multicast ID of the first multicast group is the first multicast ID.

3. The method according to claim 2, characterized in that, The first terminal receives a first outbound multicast short message sent by the satellite network device, including: The first terminal receives one or more second user frames, the one or more second user frames including a seventh field and an eighth field, the seventh field being used to indicate that the frame type of the one or more second user frames is a multicast user frame type, and the eighth field being used to indicate that the multicast ID of the multicast group corresponding to the one or more second user frames is the first multicast ID; The first terminal determines that the one or more second user frames are multicast short message frames based on the seventh field, and parses them to obtain the first multicast ID; The first terminal obtains the first outbound multicast short message based on the one or more second user frames, and parses it to obtain the user ID of the second terminal and the second information content; The first terminal displays the second information content based on the first multicast ID and the user ID of the second terminal.

4. The method according to claim 1, characterized in that, The method further includes: The first terminal sends a multicast short message query request message to the satellite network device. The multicast short message query request message includes a service type field, which is used to indicate that the service type of the multicast short message query request message is a multicast short message query type. The first terminal receives and displays a multicast short message query result message, which is generated by the satellite network device based on the multicast short message query request message.

5. The method according to claim 4, characterized in that, The service type field is used to indicate that the service type of the multicast short message query request message is a multicast short message query type, and to query the number of multicast short messages sent by the specified multicast group to the first terminal; The multicast short message query request message also includes a multicast ID field and a multicast short message ID field. The multicast ID field is used to indicate the multicast ID of the specified multicast group, and the multicast short message ID field is used to indicate the multicast short message ID of the last multicast short message among the multicast short messages that the first terminal has successfully received consecutively. The multicast SMS query result message includes a multicast SMS quantity field, which indicates the number of multicast SMS messages sent by the specified multicast group to the first terminal.

6. The method according to claim 5, characterized in that, The service type field is used to indicate that the service type of the multicast short message query request message is a multicast short message query type, and to query the number of multicast short messages sent by all multicast groups to the first terminal; The multicast SMS query request message also includes a multicast SMS ID field, which is used to indicate the ID of the last multicast SMS among the multicast SMS messages that the first terminal has successfully received consecutively; The multicast SMS query result message includes a multicast SMS quantity field, which indicates the number of multicast SMS messages sent by all multicast groups to the first terminal.

7. The method according to claim 1, characterized in that, The method further includes: The first terminal sends a multicast short message download request message to the satellite network device. The multicast short message download request message includes a service type field, which is used to indicate that the service type of the multicast short message download request message is a multicast short message download type. The first terminal receives and displays a second outbound multicast short message, which is generated by the satellite network device based on the multicast short message download request message.

8. The method according to claim 7, characterized in that, The service type field is used to indicate that the service type of the multicast SMS download request message is multicast SMS download type, and that the multicast SMS message sent to the first terminal by the specified multicast group is being downloaded. The multicast short message download request message also includes a multicast ID field and a multicast short message ID field. The multicast ID field is used to indicate the multicast ID of the specified multicast group, and the multicast short message ID field is used to indicate the multicast short message ID of the last multicast short message among the multicast short messages that the first terminal has successfully received consecutively. The second outbound multicast short message includes a download completion indication field, which is used to indicate whether the specified multicast group will send any more multicast short messages to the first terminal.

9. The method according to claim 7, characterized in that, The service type field is used to indicate that the service type of the multicast SMS download request message is multicast SMS download type, and that all multicast SMS messages sent to the first terminal by the multicast groups are downloaded. The multicast SMS download request message also includes a multicast SMS ID field, which is used to indicate the multicast SMS ID of the last multicast SMS message among the multicast SMS messages that the first terminal has successfully received consecutively. The second outbound multicast short message includes a download completion indication field, which is used to indicate whether all multicast groups will send more multicast short messages to the first terminal.

10. A method for transmitting multicast short messages in a satellite communication system, characterized in that, include: The first terminal sends an inbound multicast short message to the satellite network device. The inbound multicast short message includes a first field and a second field. The first field is used to indicate that the multicast ID of the multicast group corresponding to the inbound multicast short message is a first multicast ID. The second field is used to indicate that the information content in the inbound multicast short message is a first information content. The satellite network device receives the inbound multicast short message and parses it to obtain the first multicast ID and the first information content; The satellite network device sends a first outbound multicast short message based on the first information content; The second terminal receives the first outbound multicast short message, wherein the first terminal and the second terminal belong to the first multicast group, and the multicast ID of the first multicast group is the first multicast ID; The inbound multicast short message also includes a third field, which is used to indicate that the service type of the multicast short message is a general message service type. The first terminal sends an inbound multicast short message to the satellite network device, including: the first terminal sends one or more first user frames to the satellite network device, wherein the one or more first user frames include a fourth field, the fourth field being used to indicate that the frame type of the one or more first user frames is a multicast short message frame type.

11. The method according to claim 10, characterized in that, The satellite network equipment receives the inbound multicast short message, including: The satellite network device receives the one or more first user frames and parses them to obtain the fourth field; The satellite network device determines that the one or more first user frames are multicast short message frames based on the fourth field. The satellite network device obtains the inbound multicast short message based on the one or more first user frames, and parses it to obtain the first multicast ID and the first information content.

12. The method according to claim 10 or 11, characterized in that, The first outbound multicast short message includes a sender ID field and a fifth field. The sender ID field is used to indicate that the sender ID of the first outbound multicast short message is the user ID of the first terminal, and the fifth field is used to indicate the information content of the first outbound multicast short message.

13. The method according to claim 12, characterized in that, The satellite network device sends a first outbound multicast short message based on the first information content, including: The satellite network device sends one or more second user frames, the one or more second user frames including a sixth field and a seventh field, the sixth field being used to indicate that the frame type of the one or more second user frames is a multicast short message frame type, and the seventh field being used to indicate that the multicast ID of the multicast group corresponding to the one or more second user frames is the first multicast ID.

14. The method according to claim 13, characterized in that, The second terminal receives the first outbound multicast short message, including: The second terminal receives the one or more second user frames and parses them to obtain the sixth field; The second terminal determines that the one or more second user frames are multicast short message frames based on the sixth field, and parses them to obtain the first multicast ID; The second terminal obtains the first outbound multicast short message based on the one or more second user frames, and parses it to obtain the user ID of the first terminal and the first information content; The second terminal displays the first information content based on the first multicast ID and the user ID of the first terminal.

15. The method according to claim 10, characterized in that, Before the satellite network device sends the first outbound multicast short message based on the first information content, the method further includes: The satellite network equipment determines the satellite information and beam information of the first outgoing multicast short message.

16. The method according to claim 15, characterized in that, The inbound multicast short message includes a location information field, which is used to indicate the location information of the first terminal. The satellite network equipment determines the satellite information and beam information of the first outgoing multicast short message, including: The satellite network device parses the location information field based on the inbound multicast short message; The satellite network device obtains the satellite information and beam information of the first outgoing multicast short message based on the location information field.

17. The method according to claim 10, characterized in that, The one or more first user frames include an outbound link indication field, which is used to indicate the satellite information and beam information of the first outbound multicast short message; Before the satellite network device sends the first outbound multicast short message based on the first information content, the method further includes: The satellite network device parses the outbound link indication field based on the one or more first user frames; The satellite network device obtains the satellite information and beam information of the first outgoing multicast short message based on the outgoing link indication field.

18. The method according to claim 10, characterized in that, The method further includes: The first terminal sends a multicast short message query request message to the satellite network device. The multicast short message query request message includes a service type field, which is used to indicate that the service type of the multicast short message query request message is a multicast short message query type. The satellite network device receives the multicast short message query request message; The satellite network device generates a multicast short message query result message based on the multicast short message query request message; The satellite network device sends the multicast short message query result message to the first terminal; The first terminal receives and displays the multicast short message query result message.

19. The method according to claim 18, characterized in that, The service type field is used to indicate that the service type of the multicast short message query request message is a multicast short message query type, and to query the number of multicast short messages sent by the specified multicast group to the first terminal; The multicast short message query request message also includes a multicast ID field and a multicast short message ID field. The multicast ID field is used to indicate the multicast ID of the specified multicast group, and the multicast short message ID field is used to indicate the multicast short message ID of the last multicast short message among the multicast short messages that the first terminal has successfully received consecutively. The multicast SMS query result message includes a multicast SMS quantity field, which indicates the number of multicast SMS messages sent by the specified multicast group to the first terminal.

20. The method according to claim 18, characterized in that, The service type field is used to indicate that the service type of the multicast short message query request message is a multicast short message query type, and to query the number of multicast short messages sent by all multicast groups to the first terminal; The multicast short message query request message also includes a multicast short message ID field, which is used to indicate the multicast short message ID of the last multicast short message among the multicast short messages that the first terminal has successfully received consecutively. The multicast SMS query result message includes a multicast SMS quantity field, which indicates the number of multicast SMS messages sent by all multicast groups to the first terminal.

21. The method according to claim 10, characterized in that, The method further includes: The first terminal sends a multicast short message download request message to the satellite network device. The multicast short message download request message includes a service type field, which is used to indicate that the service type of the multicast short message download request message is a multicast short message download type. The satellite network device receives the multicast short message download request message; The satellite network device generates a second outbound multicast short message based on the multicast short message download request message; The satellite network device sends the second outbound multicast short message to the first terminal; The first terminal receives and displays the second outbound multicast short message.

22. The method according to claim 21, characterized in that, The service type field is used to indicate that the service type of the multicast SMS download request message is multicast SMS download type, and that the multicast SMS message sent to the first terminal by the specified multicast group is being downloaded. The multicast short message download request message also includes a multicast ID field and a multicast short message ID field. The multicast ID field is used to indicate the multicast ID of the specified multicast group, and the multicast short message ID field is used to indicate the multicast short message ID of the last multicast short message among the multicast short messages that the first terminal has successfully received consecutively. The second outbound multicast short message includes a download completion indication field, which is used to indicate whether the specified multicast group will send any more multicast short messages to the first terminal.

23. The method according to claim 21, characterized in that, The service type field is used to indicate that the service type of the multicast SMS download request message is multicast SMS download type, and that all multicast SMS messages sent to the first terminal by the multicast groups are downloaded. The multicast SMS download request message also includes a multicast SMS ID field, which is used to indicate the multicast SMS ID of the last multicast SMS message among the multicast SMS messages that the first terminal has successfully received consecutively. The second outbound multicast short message includes a download completion indication field, which is used to indicate whether all multicast groups will send more multicast short messages to the first terminal.

24. The method according to claim 10, characterized in that, The second terminal is one or more terminals.

25. A communication device, characterized in that, The device includes one or more processors, one or more memories, and a transceiver; wherein the transceiver, the one or more memories, and the one or more memories are coupled to the one or more processors, the one or more memories being used to store computer program code, the computer program code including computer instructions, which, when executed by the one or more processors, cause the communication device to perform the method as described in any one of claims 1-9.

26. The communication device according to claim 25, characterized in that, The communication device is a terminal.

27. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1-9.

28. A chip or chip system, used in a terminal, characterized in that, It includes a processing circuit and an interface circuit, the interface circuit being used to receive code instructions and transmit them to the processing circuit, the processing circuit being used to execute the code instructions to perform the method as described in any one of claims 1-9.

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