A multi-frame fusion transmission method and related device in a satellite communication system

Abstract

This application relates to the field of satellite communications and discloses a multi-frame fusion transmission method and related apparatus in a satellite communication system. In this system, a transmitting end can negotiate an acknowledgment mode with a receiving end using the total number of frames field and the frame sequence number field in the data frame header. This eliminates the need for additional frame header cell overhead and control signaling overhead when negotiating the acknowledgment mode between the transmitting and receiving ends.

Description

Technical Field

[0001] The present application relates to the field of satellite communications, and in particular to a multi-frame fusion transmission method and related devices in a satellite communication system. Background Art

[0002] The Beidou satellite navigation system is a major infrastructure integrating positioning, timing, and communications. The Beidou short message service (BMS) distinguishes it from other global navigation systems, such as the US GPS, Russia's GLONASS, and Europe's GALILEO. It is particularly suitable for communication in areas such as oceans, deserts, grasslands, and uninhabited areas where mobile communications are not available, cannot be reached, or where communications systems are disrupted. The Beidou-3 satellite's short message system has upgraded its short message technology. To address the specific characteristics of civilian services and equipment, a communication protocol designed specifically for the Beidou short message service requires it.

[0003] Currently, in the Beidou short message service communication system, due to the limitations of the underlying transmission capacity, the transmitter must split relatively long data packets into multiple small data segments and add frame header information to each data segment to generate multiple data frames. This frame header information may include information indicating the location of the data segment within the service data packet. The transmitter can send the data frame to the receiver. After receiving the data frame, the receiver can reassemble the entire service data packet based on the frame header information. To ensure the correct transmission of the data packet, the receiver must provide an acknowledgement to the transmitter after receiving the data frame to inform it of the data frame's reception. Currently, there are two acknowledgement modes for multi-frame transmission: stop-and-wait mode and parallel mode. Stop-and-wait mode means that after the transmitter sends a data frame, the receiver immediately provides an acknowledgement to the transmitter. The transmitter then sends the next data frame only after confirming that the receiver has received the data frame based on the acknowledgement information. Parallel mode means that the transmitter can send a group (or multiple groups) of data frames simultaneously. The receiver then waits for the transmitter to complete sending this group of data frames before sending an acknowledgment message to the transmitter. The transmitter then determines that it has received multiple data frames based on this acknowledgment message before sending the next group of data frames. However, due to limited air interface resources in the Beidou short message service communication system, complex control signaling exchanges to negotiate the acknowledgment mode between the transmitter and receiver before data transmission are supported. Summary of the Invention

[0004] This application provides a multi-frame fusion transmission method and related apparatus in a satellite communication system, enabling a transmitter to negotiate an acknowledgment mode with a receiver using the total number of frames field and the frame sequence number field in the data frame header information. This eliminates the need for additional frame header cell overhead and control signaling overhead when negotiating the acknowledgment mode between the transmitter and receiver.

[0005] In the first aspect, the present application provides a multi-frame fusion transmission method in a Beidou communication system, including: a terminal sends a first satellite link control layer protocol data unit SLC PDU to a Beidou network device, wherein the frame header information of the first SLC PDU includes a first frame total field and a first frame sequence number field, and the first frame total field and the first frame sequence number field are used to combine to indicate the confirmation mode that the terminal requests the Beidou network device to adopt; when the confirmation mode indicated by the combination of the first frame total field and the first frame sequence number field is a parallel confirmation mode, when the terminal receives the first confirmation character ACK sent by the Beidou network device, the terminal retransmits the SLC PDU in the first SLC SDU that the Beidou network device has not received to the Beidou network device; wherein the first ACK is used to indicate the frame sequence number of the SLC PDU that the Beidou network device has not received in the N SLC PDUs of the first satellite link control layer service data unit SLC SDU, the N SLC PDUs of the first SLC SDU include the first SLC PDU, the first frame total field is used to indicate the total number N of SLC PDUs in the first SLC SDU, and the first frame sequence number field is used to indicate the first SLC PDU in the first SLC SDU. Frame sequence number in the SDU.

[0006] This application provides a multi-frame fusion transmission method for a Beidou communication system, enabling a terminal to negotiate a confirmation mode with a Beidou network device using the total number of frames field and the frame sequence number field in the data frame header information. This eliminates the need for additional frame header cell overhead and control signaling overhead when the terminal negotiates the confirmation mode with the Beidou network device.

[0007] In one possible implementation, when the confirmation mode indicated by the combination of the first frame total field and the first frame sequence number field is a parallel confirmation mode, when the terminal 100 receives the second ACK sent by the Beidou network device 200, the terminal 100 sends one or more SLC PDUs in the second SLC SDU to the Beidou network device 200, and the second ACK is used to indicate that the Beidou network device 200 has received N SLC PDUs in the first SLC SDU.

[0008] In one possible implementation, when the confirmation mode indicated by the combination of the first frame total field and the first frame sequence number field is a parallel confirmation mode, and the terminal 100 does not receive the ACK sent by the Beidou network device 200 within the ACK reception time window after sending the N SLC PDUs in the first SLC SDU, the terminal 100 retransmits the N SLC PDUs in the first SLC SDU to the Beidou network device 200.

[0009] In one possible implementation, when the confirmation mode indicated by the combination of the first frame total field and the first frame sequence number field is a stop-and-wait confirmation mode, the terminal 100 receives a third ACK sent by the Beidou network device 200, and the third ACK is used to indicate that the Beidou network device 200 has received the first SLC PDU; the terminal 100 sends a second SLC PDU to the Beidou network device 200.

[0010] In one possible implementation, the method also includes: when the confirmation mode indicated by the combination of the first frame total field and the first frame sequence number field is a stop-and-wait confirmation mode, and the terminal 100 does not receive the ACK sent by the Beidou network device 200 within the ACK reception time window after sending the first SLC PDU, the terminal 100 retransmits the first SLC PDU to the Beidou network device 200.

[0011] In one possible implementation, in the stop-and-wait confirmation mode, the value of the second frame sequence number field in the second SLC PDU is different from the value of the first frame sequence number field, and the value of the second frame total number field is the same as the value of the first frame total number field; or, the value of the second frame sequence number field is the same as the value of the first frame sequence number field, and the value of the second frame total number field is different from the value of the first frame total number field; or, the value of the second frame sequence number field is different from the value of the first frame sequence number field, and the value of the second frame total number field is different from the value of the first frame total number field.

[0012] In a possible implementation, in the parallel confirmation mode, the value of the first frame total number field is greater than or equal to the value of the first frame sequence number field.

[0013] In a possible implementation, in the stop-and-wait mode confirmation, the value of the first frame total number field is smaller than the value of the first frame sequence number field.

[0014] In one possible implementation, in the parallel confirmation mode, the terminal 100 determines the starting time of the ACK receiving time window based on the time when the terminal 100 sends the last SLC PDU in the first SLC SDU, the switching time length of the terminal 100 from the sending state to the receiving state, the air interface propagation delay and the signal processing scheduling delay of the Beidou network device 200; the terminal 100 starts to receive the ACK sent by the Beidou network device 200 at the starting time of the ACK receiving time window.

[0015] The formula for the terminal 100 to determine the starting time in the ACK reception time window is:

[0016] tUeTxEnd+tTx2RxSwitch<tUeStartRcvAck<tUeTxEnd+2*tPropagate+tStationProcess

[0017] Among them, tUeStartRcvAck is the starting time of the ACK receiving time window, tUeTxEnd is the time when the terminal 100 sends the last SLC PDU in the first SLC SDU, tTx2RxSwitch is the switching time length of the terminal 100 from the sending state to the receiving state, tPropagate is the air interface propagation delay, and tStationProcess is the signal processing scheduling delay on the Beidou network device 200.

[0018] In one possible implementation, in the parallel confirmation mode, the terminal 100 determines the end time of the ACK reception time window based on the time length of the physical frame sent by the terminal 100, the air interface propagation delay, the signal processing scheduling delay of the Beidou network device 200, the time length of the physical frame sent by the Beidou network device 200, and the time alignment deviation of the physical frame sent by the Beidou network device 200; the terminal 100 stops receiving the ACK sent by the Beidou network device 200 at the end time of the ACK reception time window.

[0019] The formula for the terminal 100 to determine the end time within the ACK reception time window is:

[0020] tUeStartRcvAck=tUeTxEnd+tUeUlFrameLen+2*tPropagate+tStationProcess+tStationDlFrameLen+δ

[0021] Among them, tUeEndRcvAck is the end time of the ACK reception time window, tUeUlFrameLen is the time length of the physical frame sent by the terminal 100, tPropagate is the air interface propagation delay, tStationProcess is the signal processing scheduling delay of the Beidou network device 200, tStationDlFrameLen is the time length of the physical frame sent by the Beidou network device 200, and δ is the time alignment deviation of the Beidou network device 200 sending the physical frame.

[0022] In one possible implementation, in the stop-and-wait mode, the terminal 100 determines the starting time of the ACK reception time window based on the starting time of the terminal 100 sending the first SLC PDU, the time length of the physical frame sent by the terminal 100, the switching time length of the terminal 100 from the sending state to the receiving state, the air interface propagation delay and the signal processing scheduling delay of the Beidou network device 200; the terminal 100 starts to receive the ACK sent by the Beidou network device 200 at the starting time of the ACK reception time window.

[0023] The formula for the terminal 100 to determine the start time of the ACK reception time window is:

[0024] t0+tUeUlFrameLen+TTx2RxSwitch <tUeStartRcvAck<t0+tUeUlFrameLen+2*tPropagate+tStationProcess

[0025] Among them, tUeEndRcvAck is the end time of the ACK receiving time window, t0 is the starting time when the terminal 100 sends the first SLC PDU, tUeUlFrameLen is the time length of the physical frame sent by the terminal 100, tTx2RxSwitch is the switching time length of the terminal 100 from the sending state to the receiving state, tPropagate is the air interface propagation delay, and tStationProcess is the signal processing scheduling delay of the Beidou network device 200.

[0026] In one possible implementation, in the stop-and-wait mode, the terminal 100 determines the end time of the ACK reception time window based on the time length of the physical frame sent by the terminal 100, the air interface propagation delay, the signal processing scheduling delay of the Beidou network device 200, the time length of the physical frame sent by the Beidou network device 200, and the time alignment deviation of the physical frame sent by the Beidou network device 200; the terminal 100 stops receiving the ACK sent by the Beidou network device 200 at the end time of the ACK reception time window.

[0027] The formula for the terminal 100 to determine the end time of the ACK reception time window is:

[0028] tUeEndRcvAck=t0+UeUlFrameLen+tPropagate*2+tStationProcess+tStationDlFrameLen+δ

[0029] Among them, tUeEndRcvAck is the end time of the ACK reception time window, t0 is the starting time when the terminal 100 sends the first SLC PDU, tUeUlFrameLen is the time length of the physical frame sent by the terminal 100, tStationDlFrameLen is the time length of the physical frame sent by the Beidou network device 200, tPropagate is the air interface propagation delay, tStationProcess is the signal processing scheduling delay of the Beidou network device 200, and δ is the time alignment deviation of the Beidou network device 200 to send the physical frame.

[0030] In a second aspect, the present application provides a multi-frame fusion transmission method in a Beidou communication system, comprising:

[0031] The Beidou network device receives a first SLC PDU sent by a terminal, wherein the frame header information of the first SLC PDU includes a first total number field and a first frame sequence number field, and the first total number field and the first frame sequence number field are used to combine and indicate the confirmation mode that the terminal requests the Beidou network device to adopt; when the confirmation mode used to be combinedly indicated by the first total number field and the first frame sequence number field is a parallel confirmation mode, the Beidou network device continues to receive the SLC PDU in the first SLC SDU sent by the terminal; wherein the first total number field is used to indicate the total number N of SLC PDUs in the first SLC SDU, and the first frame sequence number field is used to indicate the frame sequence number of the first SLC PDU in the first SLC SDU; when the number M of SLC PDUs received by the Beidou network device in the first SLC SDU is less than N, the Beidou network device sends a first ACK to the terminal, where M is a positive integer, and the first ACK is used to indicate the frame sequence number of the SLC PDU not received by the Beidou network device in the N SLC PDUs of the first SLC SDU; the Beidou network device receives the SLC PDU not received by the Beidou network device in the first SLC SDU retransmitted by the terminal.

[0032] This application provides a multi-frame fusion transmission method for a Beidou communication system, enabling a terminal to negotiate a confirmation mode with a Beidou network device using the total number of frames field and the frame sequence number field in the data frame header information. This eliminates the need for additional frame header cell overhead and control signaling overhead when the terminal negotiates the confirmation mode with the Beidou network device.

[0033] In one possible implementation, when M is equal to N, the Beidou network device 200 sends a second ACK to the terminal 100, wherein the second ACK is used to indicate that the Beidou network device 200 has received N SLC PDUs in the first SLC SDU; the Beidou network device 200 receives one or more SLC PDUs in the second SLC SDU sent by the terminal 100.

[0034] In one possible implementation, when the confirmation mode indicated by the combination of the first frame total field and the first frame sequence number field is a stop-and-wait confirmation mode, the Beidou network device 200 sends a third ACK to the terminal 100, and the third ACK is used to indicate that the Beidou network device 200 has received the first SLC PDU; the Beidou network device 200 receives the second SLC PDU sent by the terminal 100.

[0035] In one possible implementation, in the stop-and-wait confirmation mode, the value of the second frame sequence number field in the second SLC PDU is different from the value of the first frame sequence number field, and the value of the second frame total number field is the same as the value of the first frame total number field; or, the value of the second frame sequence number field is the same as the value of the first frame sequence number field, and the value of the second frame total number field is different from the value of the first frame total number field; or, the value of the second frame sequence number field is different from the value of the first frame sequence number field, and the value of the second frame total number field is different from the value of the first frame total number field.

[0036] In a possible implementation, in the parallel confirmation mode, the value of the first frame total number field is greater than or equal to the value of the first frame sequence number field.

[0037] In a possible implementation, in the stop-and-wait confirmation mode, the value of the first frame total number field is smaller than the value of the first frame sequence number field.

[0038] In one possible implementation, in parallel confirmation mode, the Beidou network device 200 determines the remaining time length of the SLC PDU receiving window based on the frame sequence number of the first SLC PDU, the total number of SLC PDUs in the first SLC SDU, the reception time of the first SLC PDU, the frame interval of the physical frame sent by the terminal 100, and the time length of the physical frame sent by the terminal 100.

[0039] The Beidou network device 200 determines the remaining time length of the SLC PDU receiving window by the following formula:

[0040] tStationRevWindow=tStaRevRctSP+(nUeTotalFrameNum-nRevFrameSN-1)*(tUeTxInterval+tUeUlFrameLen)

[0041] Wherein, tStationRevWindow is the remaining time length of the SLC PDU receiving window, ttStaRevRctSP is the reception time of the first SLC PDU, nUeTotalFrameNum is the total number of SLC PDUs in the first SLC SDU, nRevFrameSN is the frame sequence number of the first SLC PDU, tUeTxInterval is the frame interval for sending physical frames by terminal 100, and tUeUlFrameLen is the time length of the physical frame sent by terminal 100.

[0042] In a possible implementation, in the parallel confirmation mode, the Beidou network device 200 determines the time point for sending the ACK based on the remaining time length of the SLC PDU receiving window and the signal processing scheduling delay of the Beidou network device 200.

[0043] The Beidou network device 200 determines the time point for sending the ACK using the following formula:

[0044] tStationSendAck=tStationRevWindow+tStationProcess+δ

[0045] Among them, tStationSendAck is the time point when the Beidou network device 200 sends ACK, tStationRevWindow is the remaining time length of the SLC PDU receiving window, tStationProcess is the signal processing scheduling delay on the Beidou network device 200, and δ is the sending time alignment deviation of the outbound physical frame on the Beidou network device 200.

[0046] In a third aspect, the present application provides a Beidou communication system, including: a terminal and a Beidou network device; wherein,

[0047] A terminal is used to send a first SLC PDU to a Beidou network device, wherein the frame header information of the first SLC PDU includes a first frame total field and a first frame sequence number field, and the first frame total field and the first frame sequence number field are used to combine to indicate the confirmation mode that the terminal requests the Beidou network device to adopt; the Beidou network device is used to send a first ACK to the terminal when the confirmation mode indicated by the combination of the first frame total field and the first frame sequence number field is a parallel confirmation mode; wherein the first ACK is used to indicate the frame sequence number of the SLC PDU not received by the Beidou network device in the N SLC PDUs of the first SLC SDU, the N SLC PDUs of the first SLC SDU include the first SLC PDU, the first frame total field is used to indicate the total number N of SLC SDUs in the first SLC PDU, and the first frame sequence number field is used to indicate the frame sequence number of the first SLC PDU in the first SLC SDU; the terminal is also used to retransmit the SLC PDU not received by the Beidou network device in the first SLC SDU to the Beidou network device after receiving the first ACK.

[0048] In a possible implementation manner, the terminal may also execute the method in any possible implementation manner of the first aspect above.

[0049] In a possible implementation, the Beidou network device may also execute the method in any possible implementation of the first aspect above.

[0050] In a fourth aspect, the present application provides a communication device comprising one or more processors, one or more memories, and a transceiver. The transceiver and the one or more memories are coupled to the one or more processors, the one or more memories being configured to store computer program code, the computer program code comprising computer instructions. When the one or more processors execute the computer instructions, the communication device performs the method of any possible implementation of the first aspect described above.

[0051] The communication device may be a terminal or other product-type equipment.

[0052] In a fifth aspect, the present application provides a communication device comprising one or more processors, one or more memories, and a transceiver. The transceiver and the one or more memories are coupled to the one or more processors, the one or more memories being configured to store computer program code, the computer program code comprising computer instructions. When the one or more processors execute the computer instructions, the communication device performs the method of any possible implementation of the second aspect described above.

[0053] The communication device may be a Beidou network device, or any network element or a combination of multiple network elements in the Beidou network device.

[0054] In a sixth aspect, the present application provides a computer storage medium comprising computer instructions, which, when executed on a computer, enable the computer to execute the method in any possible implementation of the first aspect.

[0055] In a seventh aspect, the present application provides a computer storage medium comprising computer instructions, which, when executed on a computer, enable the computer to execute the method in any possible implementation of the second aspect.

[0056] In an eighth aspect, the present application provides a computer program product, which, when executed on a computer, enables the computer to execute the method in any possible implementation of the first aspect.

[0057] In a ninth aspect, the present application provides a computer program product, which, when executed on a computer, enables the computer to execute the method in any possible implementation of the second aspect.

[0058] In the tenth aspect, the present application provides a chip or chip system, which is 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 execute the method in any possible implementation of the first aspect above. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1A schematic diagram of the architecture of a Beidou communication system provided in an embodiment of the present application;

[0060] Figure 2A A schematic diagram of the data inbound transmission process in a Beidou communication system provided in an embodiment of the present application;

[0061] Figure 2B A schematic diagram of the data outbound transmission process in a Beidou communication system provided in an embodiment of the present application;

[0062] Figure 3 A schematic diagram of the block response mechanism transmission process in the Wi-Fi technology provided in an embodiment of the present application;

[0063] Figure 4 A schematic diagram of the structure of a terminal provided in an embodiment of the present application;

[0064] Figure 5 A schematic diagram of a protocol encapsulation architecture for inbound data of a Beidou communication system provided in an embodiment of the present application;

[0065] Figure 6 A schematic diagram of a protocol parsing architecture for inbound data of a Beidou communication system provided in an embodiment of the present application;

[0066] Figure 7 A schematic diagram of a protocol encapsulation architecture for outbound data of a Beidou communication system provided in an embodiment of the present application;

[0067] Figure 8 A schematic diagram of a protocol parsing architecture for outbound data of a Beidou communication system provided in an embodiment of the present application;

[0068] Figure 9 A schematic diagram of a stop-and-wait feedback mode of the SLC layer provided in an embodiment of the present application;

[0069] Figure 10 A schematic diagram of a parallel feedback mode of an SLC layer provided in an embodiment of the present application;

[0070] Figure 11 A schematic diagram of the frame format of an inbound SLC PDU provided in an embodiment of the present application;

[0071] Figure 12 A schematic diagram of a frame format of an outbound SLC PDU provided in an embodiment of the present application;

[0072] Figure 13 This is a processing sequence diagram of the SLC layer's stop-and-wait confirmation mode when data is inbound, provided by an embodiment of the present application;

[0073] Figure 14This is a processing sequence diagram of the SLC layer's stop-and-wait confirmation mode when data is outbound provided by an embodiment of the present application;

[0074] Figure 15 A processing sequence diagram of a parallel confirmation mode of the SLC layer when data is inbound provided by an embodiment of the present application;

[0075] Figure 16 A processing sequence diagram of a parallel confirmation mode of the SLC layer when data is outbound provided by an embodiment of the present application;

[0076] Figure 17 A flowchart of a multi-frame fusion transmission method in a Beidou communication system provided in an embodiment of the present application;

[0077] Figure 18 A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0078] Figure 19 A schematic structural diagram of another communication device provided in an embodiment of the present application;

[0079] Figure 20 A schematic structural diagram of another communication device provided in an embodiment of the present application;

[0080] Figure 21 A schematic diagram of the structure of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0081] The following is a clear and detailed description of the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in the text is only a description of the association relationship between related objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0082] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to imply or suggest relative importance or implicitly indicate the number of the technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of this application, unless otherwise specified, "plurality" means two or more.

[0083] The following introduces a Beidou communication system 10 provided in an embodiment of the present application.

[0084] Figure 1A schematic diagram of the architecture of a Beidou communication system 10 provided in an embodiment of the present application is shown.

[0085] As above Figure 1 As shown, the Beidou communication system 10 may include a terminal 100, a Beidou short message satellite 21, a Beidou network device 200, a short message center 25, and a terminal 300. Optionally, the Beidou communication system 10 may further include a national emergency rescue platform 26 and a national emergency rescue center 27.

[0086] Terminal 100 can send short messages to BeiDou short message satellites 21. BeiDou short message satellites 21 only relay the short messages sent by terminal 100 and directly forward them to BeiDou network devices 200 on the ground. BeiDou network devices 200 can parse the short messages forwarded by the satellites according to the BeiDou communication protocol and forward the general message content parsed from the short messages to a short message service center (SMSC) 25. The SMSC 25 can forward the message content to terminal 300 via a traditional cellular communication network. BeiDou network devices 200 can also transmit emergency messages sent by terminal 100 to the National Emergency Rescue Center 27 via the National Emergency Rescue Platform 26.

[0087] The terminal 300 can also send a short message to the short message center 25 through a traditional cellular communication network. The short message center 25 can forward the short message of the terminal 300 to the Beidou network device 200. The Beidou network device 200 can relay the short message of the terminal 300 to the terminal 100 via the Beidou short message satellite 21.

[0088] Among them, the above-mentioned Beidou network equipment 200 may include a Beidou ground transceiver station 22, a Beidou central station 23 and a Beidou short message fusion communication platform 24. Among them, the Beidou ground transceiver station 22 may include one or more devices with a sending function and one or more devices with a receiving function, or may include one or more devices with a sending function and a receiving function, which is not limited here. The Beidou ground transceiver station 22 can be used for the Beidou network equipment 200 to process data at the physical layer (physical layer protocol, PHY). The Beidou central station 23 can be used for the Beidou network equipment 200 to process data at the satellite link layer (satellite link control protocol, SLC) layer and the message convergence layer (message data convergence protocol, MDCP). The Beidou short message fusion communication platform 24 can be used for the data processing function at the application layer (application layer protocol, APP).

[0089] Because the BeiDou communication system 10 communicates via satellite links, its main characteristics are long latency (approximately 270ms one-way) and high link loss. Currently, the BeiDou communication system 10 primarily supports short message bursts and does not support link state management, mobility management, or broadcast control information.

[0090] The terminal 100 can actively send data to the Beidou network device 200 via the Beidou short message satellite 21. However, due to the lack of air interface signaling, the ground central station cannot actively page the user. Due to the long transmission distance of satellite communication, the Beidou communication system 10 requires high transmission power for the terminal 100. Due to the limitations of the radio frequency components on the current terminal 100, the terminal 100 cannot continuously send signals to the Beidou short message satellite 21 for a long time. In order to minimize damage to the radio frequency components on the terminal 100, the radio frequency components of the terminal 100 must stop working for a period of time after being in the sending state for a period of time before switching to the sending state to continue working. The duration of the sending state on the terminal 100 is determined by the underlying hardware capabilities of the terminal 100. In the above-mentioned Beidou communication system 10, in order to ensure that the data received and sent by the terminal 100 do not interfere with each other, the terminal 100 does not support sending and receiving data at the same time. The terminal 100 needs to wait for receiving data sent by the Beidou network device 200 after sending data.

[0091] The working mode of the Beidou network device 200 may be a duplex mode, in which data can be sent and received simultaneously, and the Beidou network device 200 may send and receive data for a long time.

[0092] Figure 2A The present invention shows a data inbound transmission process in a Beidou communication system provided by an embodiment of the present application.

[0093] like Figure 2A As shown, data inbound may refer to the terminal 100 sending data to the Beidou network device 200. For example, the terminal 100 may send a data frame to the Beidou ground transceiver station 22. The Beidou ground transceiver station 22 may send the data frame to the Beidou central station 23. The Beidou central station 23 may aggregate the data frames into an application layer message and report it to the Beidou short message fusion communication platform 24. After receiving the data frame sent by the terminal 100, the Beidou central station 23 may return an SLC layer acknowledgment character (ACK) to the terminal 100. The ACK may be used to indicate whether the Beidou network device 200 has successfully received the data frame sent by the terminal 100.

[0094] Figure 2B The embodiment of the present application provides a data outbound transmission process in a Beidou communication system.

[0095] like Figure 2B As shown, data outbound can refer to the Beidou network device 200 sending data to the terminal 100. For example, the Beidou short message fusion communication platform 24 in the Beidou network device 200 can send an application layer message to the Beidou central station 23. The Beidou central station 23 can then split the application layer message into one or more data frames and send them to the Beidou ground transceiver station 22. The Beidou short message satellite 21 relays the data frames and sends them to the terminal 100. After receiving the data frames, the terminal 100 can return an SLC layer ACK to the Beidou central station 23. This ACK can be used to confirm whether the terminal 100 has successfully received the data frames sent by the Beidou network device 200.

[0096] The following describes the block response mechanism in the Wi-Fi technology provided by this application.

[0097] Wi-Fi technology uses two block acknowledgment mechanisms: immediate block acknowledgment and delayed block acknowledgment. Immediate block acknowledgment is suitable for high-bandwidth, low-latency services. Delayed block acknowledgment is suitable for services that can tolerate moderate delays.

[0098] The immediate block acknowledgement mechanism means that after the initiator sends a data frame to the receiver, the receiver can return an acknowledgment (ACK) frame to the initiator. After receiving the ACK frame and confirming that the receiver has received the data frame, the initiator can send the next data frame to the receiver. If the initiator determines that the receiver has not received the sent data frame, the initiator can resend the data frame to the receiver.

[0099] The delayed block acknowledgment mechanism allows an initiator to continuously send multiple data frames to a recipient. After receiving these frames, the recipient returns an ACK frame to the initiator, providing feedback on the reception status of these frames. Upon receiving this ACK frame, if the initiator determines based on the ACK frame that any of the sent frames were lost, it can resend the lost frame to the recipient. If the initiator determines based on the ACK frame that all of the sent frames have been received, it can send a new frame to the recipient.

[0100] In Wi-Fi technology, the initiator must negotiate a block acknowledgment mechanism with the receiver through signaling before transmitting data frames. After the block acknowledgment transmission session ends, the initiator must also terminate the negotiated block acknowledgment mechanism with the receiver through signaling. The next time a data transmission session begins, the initiator and receiver must negotiate the block acknowledgment mechanism again through signaling.

[0101] Figure 3 The figure shows a flow chart of the block response mechanism transmission in Wi-Fi technology.

[0102] like Figure 3 As shown, the process of block response mechanism transmission in Wi-Fi technology may include the following steps:

[0103] (a) Session establishment phase:

[0104] 1. The initiator (orinator) sends an Add Block Acknowledgement Request (ADDBARequest) to the recipient (recipient). The ADDBARequest is used to request the establishment of a designated block acknowledgment mechanism with the recipient. The designated block acknowledgment mechanism includes the aforementioned immediate block acknowledgment mechanism or delayed block acknowledgment mechanism.

[0105] 2. After receiving the ADDBA Request, the recipient returns an ACK to the initiator. The ACK is used to indicate that the recipient has received the ADDBA Request.

[0106] 3. After sending an ACK indicating receipt of the ADDBA Request, the recipient sends an ADDBA Response to the initiator. The ADDBA Response indicates that the recipient agrees to use the specified block acknowledgment mechanism.

[0107] 4. After receiving the ADDBA Response, the initiator can return an ACK to the recipient. The ACK is used to indicate that the initiator has received the ADDBA Response.

[0108] (b) Data transmission (Data and Block ACK) phase:

[0109] 5. The initiator sends the data frame in the MAC protocol data unit (QoSData MPDU) of QoS data to the recipient according to the sending mechanism of the data frame in the specified block response mechanism.

[0110] 6. After sending the data frame according to the data frame sending mechanism in the specified block acknowledgment mechanism, the initiator sends a Block ACK Request frame to the recipient. The Block ACK Request frame is used to request the recipient to send a Block ACK for the data frame in the received QoSData MPDU.

[0111] 7. After receiving the block ACK request frame sent by the initiator, the recipient can return a block ACK for the data frame in the received QoSDataMPDU to the initiator.

[0112] After the initiator receives the block ACK, if the block ACK indicates that the receiver has received all the data frames, the initiator can continue to send new data frames to the receiver.

[0113] In one session, steps 5-7 can be executed multiple times in a loop.

[0114] (c) Session Closure (Tear Down) Phase:

[0115] 8. After the initiator has sent all data frames in the session, it can send a Delete Block Acknowledgement Request (DELBA Request) frame to the recipient. The DELBA Request frame is used to request the recipient to close the session using the specified block acknowledgement mechanism.

[0116] 9. After receiving the DELBARequest frame, the recipient can return an ACK for the DELBARequest frame to the initiator.

[0117] When the initiator receives the ACK for the DELBA Request frame, it can determine that the session using the specified block response mechanism has been closed with the recipient.

[0118] As can be seen from the above process, Wi-Fi's block ACK transmission process requires the initiator and receiver to negotiate the block ACK mechanism to be used in each session through complex signaling before each data transmission. At the end of the session, the initiator and receiver also need to use complex signaling to deactivate the block ACK mechanism. The main characteristics of the Beidou communication system 10 are: 1. Long latency; 2. High link loss; 3. Support for primarily bursty short message services; 4. No support for link state management, mobility management, or broadcast control information. The limited air interface resources in the Beidou communication system 10 cannot meet the signaling requirements for negotiating the block ACK mechanism in Wi-Fi.

[0119] Therefore, embodiments of the present application provide a multi-frame fusion transmission method in a Beidou communication system. This method enables a transmitting end in the Beidou communication system to negotiate an acknowledgment mode with a receiving end using the total number of frames field and the frame sequence number field in the frame header information of a data frame. This allows the transmitting end and the receiving end to negotiate an acknowledgment mode without adding additional frame header and control signaling overhead.

[0120] Figure 4 A schematic structural diagram of the terminal 100 is shown.

[0121] The embodiment will be described in detail below using terminal 100 as an example. It should be understood that Figure 4 The terminal 100 shown is only an example, and the terminal 100 may have more Figure 4 More or fewer components may be shown, two or more components may be combined, or the components may be arranged differently. Figure 4 The various components shown in the drawings may be implemented in hardware, software, or a combination of hardware and software, including one or more signal processing and / or application specific integrated circuits.

[0122] The terminal 100 may include: a processor 110, an external memory interface 120, an internal memory 121, a universal serial bus (USB) interface 130, a charging management module 140, a power management module 141, a battery 142, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a speaker 170A, a receiver 170B, a microphone 170C, an earphone interface 170D, a sensor module 180, a button 190, a motor 191, an indicator 192, a camera 193, a display 194, and a subscriber identification module (SIM) card interface 195, etc. The sensor module 180 may include a pressure sensor 180A, a gyroscope sensor 180B, an air pressure sensor 180C, a magnetic sensor 180D, an acceleration sensor 180E, a distance sensor 180F, a proximity light 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.

[0123] It should be understood that the structure illustrated in the embodiments of the present invention does not constitute a specific limitation on terminal 100. In other embodiments of the present application, terminal 100 may include more or fewer components than shown, or may combine or separate certain components, or arrange the components differently. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0124] The processor 110 may include one or more processing units. For example, the processor 110 may include an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a memory, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU). The different processing units may be independent devices or integrated into one or more processors.

[0125] The controller may be the nerve center and command center of the terminal 100. The controller may generate an operation control signal according to the instruction operation code and the timing signal to complete the control of fetching and executing instructions.

[0126] Processor 110 may also include a memory for storing instructions and data. In some embodiments, the memory in processor 110 is a cache memory. This memory can store instructions or data that have just been used or are being recycled by processor 110. If processor 110 needs to use the same instruction or data again, it can directly access the memory. This avoids duplicate accesses, reduces processor 110 latency, and thus improves system efficiency.

[0127] In some embodiments, the processor 110 may include one or more interfaces. The interfaces may include an inter-integrated circuit (I2C) interface, an inter-integrated circuit sound (I2S) interface, a pulse code modulation (PCM) interface, a universal asynchronous receiver / transmitter (UART) interface, a mobile industry processor interface (MIPI), a general-purpose input / output (GPIO) interface, a subscriber identity module (SIM) interface, and / or a universal serial bus (USB) interface.

[0128] The I2C interface is a bidirectional synchronous serial bus that includes a serial data line (SDA) and a serial clock line (SCL). In some embodiments, the processor 110 may include multiple I2C bus lines. The processor 110 may be coupled to the touch sensor 180K, the charger, the flash, the camera 193, and the like via different I2C bus interfaces. For example, the processor 110 may be coupled to the touch sensor 180K via the I2C interface, enabling communication between the processor 110 and the touch sensor 180K via the I2C bus interface, thereby implementing the touch function of the terminal 100.

[0129] The I2S interface can be used for audio communication. In some embodiments, the processor 110 can include multiple I2S buses. The processor 110 can be coupled to the audio module 170 via the I2S bus to enable communication between the processor 110 and the audio module 170. In some embodiments, the audio module 170 can transmit audio signals to the wireless communication module 160 via the I2S interface, enabling the function of answering calls through a Bluetooth headset.

[0130] The PCM interface can also be used for audio communication, sampling, quantizing, and encoding analog signals. In some embodiments, the audio module 170 and the wireless communication module 160 can be coupled via a PCM bus interface. In some embodiments, the audio module 170 can also transmit audio signals to the wireless communication module 160 via the PCM interface, enabling the function of answering calls via a Bluetooth headset. Both the I2S interface and the PCM interface can be used for audio communication.

[0131] The UART interface is a universal serial data bus used for asynchronous communication. This bus can be a bidirectional communication bus. It converts the data to be transmitted between serial communication and parallel communication. In some embodiments, the UART interface is typically used to connect the processor 110 and the wireless communication module 160. For example, the processor 110 communicates with the Bluetooth module in the wireless communication module 160 via the UART interface to implement Bluetooth functionality. In some embodiments, the audio module 170 can transmit audio signals to the wireless communication module 160 via the UART interface, enabling the function of playing music through Bluetooth headphones.

[0132] The MIPI interface can be used to connect the processor 110 to peripheral devices such as the display 194 and the camera 193. MIPI interfaces include the camera serial interface (CSI) and the display serial interface (DSI). In some embodiments, the processor 110 and the camera 193 communicate via the CSI interface to implement the camera function of the terminal 100. The processor 110 and the display 194 communicate via the DSI interface to implement the display function of the terminal 100.

[0133] The GPIO interface can be configured via software. The GPIO interface can be configured as either a control signal or a data signal. In some embodiments, the GPIO interface can be used to connect the processor 110 to the camera 193, display 194, wireless communication module 160, audio module 170, sensor module 180, etc. The GPIO interface can also be configured as an I2C interface, an I2S interface, a UART interface, a MIPI interface, etc.

[0134] The USB interface 130 is an interface that complies with USB standards and may be a Mini USB interface, a Micro USB interface, a USB Type-C interface, or the like. The USB interface 130 can be used to connect a charger to charge the terminal 100 and to transfer data between the terminal 100 and peripheral devices. It can also be used to connect headphones to play audio. This interface can also be used to connect other electronic devices, such as augmented reality devices.

[0135] It is understood that the interface connection relationship between the modules illustrated in the embodiment of the present invention is merely an illustrative description and does not constitute a structural limitation on the terminal 100. In other embodiments of the present application, the terminal 100 may also adopt a different interface connection method from the above embodiment, or a combination of multiple interface connection methods.

[0136] The charging management module 140 is configured to receive charging input from a charger. The charger can be either a wireless charger or a wired charger. In some wired charging embodiments, the charging management module 140 can receive charging input from the wired charger via the USB interface 130. In some wireless charging embodiments, the charging management module 140 can receive wireless charging input via the wireless charging coil of the terminal 100. While charging the battery 142, the charging management module 140 can also power the electronic device through the power management module 141.

[0137] The power management module 141 is used to connect the battery 142, the charging management module 140 and the processor 110. The power management module 141 receives input from the battery 142 and / or the charging management module 140, and provides power to the processor 110, the internal memory 121, the external memory, the display 194, the camera 193, and the wireless communication module 160. The power management module 141 can also be used to monitor parameters such as battery capacity, battery cycle count, and battery health status (leakage, impedance). In some other embodiments, the power management module 141 can also be set in the processor 110. In other embodiments, the power management module 141 and the charging management module 140 can also be set in the same device.

[0138] The wireless communication function of the terminal 100 can be implemented through the antenna 1, the antenna 2, the mobile communication module 150, the wireless communication module 160, the modem processor and the baseband processor.

[0139] Antenna 1 and Antenna 2 are used to transmit and receive electromagnetic wave signals. Each antenna in terminal 100 can be used to cover a single or multiple communication frequency bands. Different antennas can also be reused to improve antenna utilization. For example, antenna 1 can be reused as a diversity antenna for a wireless local area network. In other embodiments, the antennas can be used in conjunction with a tuning switch.

[0140] The mobile communication module 150 can provide solutions for wireless communications including 2G / 3G / 4G / 5G applied on the terminal 100. The mobile communication module 150 may include at least one filter, a switch, a power amplifier, a low noise amplifier (LNA), etc. The mobile communication module 150 can receive electromagnetic waves from the antenna 1, and filter, amplify, and process the received electromagnetic waves, and transmit them to the modulation and demodulation processor for demodulation. The mobile communication module 150 can also amplify the signal modulated by the modulation and demodulation processor, and convert it into electromagnetic waves for radiation through the antenna 1. In some embodiments, at least some of the functional modules of the mobile communication module 150 can be set in the processor 110. In some embodiments, at least some of the functional modules of the mobile communication module 150 can be set in the same device as at least some of the modules of the processor 110.

[0141] The modem processor may include a modulator and a demodulator. The modulator is used to modulate the low-frequency baseband signal to be transmitted into a medium-high frequency signal. The demodulator is used to demodulate 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 being processed by the baseband processor, the low-frequency baseband signal is passed to the application processor. The application processor outputs a sound signal through an audio device (not limited to the speaker 170A, the receiver 170B, etc.) or displays an image or video through the display screen 194. In some embodiments, the modem processor may be an independent device. In other embodiments, the modem processor may be independent of the processor 110 and be set in the same device as the mobile communication module 150 or other functional modules.

[0142] The wireless communication module 160 can provide wireless communication solutions applied 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 module, frequency modulation (FM), near field communication (NFC), infrared technology (IR), etc. 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 the antenna 2, frequency modulates and filters the electromagnetic wave signals, and sends the processed signals to the processor 110. The wireless communication module 160 can also receive the signal to be sent from the processor 110, frequency modulate it, amplify it, and convert it into electromagnetic waves for radiation through the antenna 2.

[0143] 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 the Beidou network equipment 200, and the satellite communication module can support short message transmission between the Beidou network equipment 200.

[0144] In some embodiments, the antenna 1 of the terminal 100 is coupled to the mobile communication module 150, and the antenna 2 is coupled to the wireless communication module 160, so that the terminal 100 can communicate with the network and other devices through wireless communication technologies. The wireless communication technologies 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 technology. The GNSS may include a global positioning system (GPS), a global navigation satellite system (GLONASS), a Beidou navigation satellite system (BDS), a quasi-zenith satellite system (QZSS) and / or a satellite based augmentation system (SBAS).

[0145] Terminal 100 implements display functions through a GPU, display screen 194, and an application processor. The GPU is a microprocessor for image processing that connects display screen 194 and the application processor. The GPU is used to perform mathematical and geometric calculations for graphics rendering. Processor 110 may include one or more GPUs that execute program instructions to generate or modify display information.

[0146] Display screen 194 is used to display images, videos, and the like. Display screen 194 includes a display panel. The display panel can be a liquid crystal display (LCD), an organic light-emitting diode (OLED), an active-matrix organic light-emitting diode (AMOLED), a flexible light-emitting diode (FLED), a MiniLED, a MicroLED, a Micro-oLed, or a quantum dot light-emitting diode (QLED). In some embodiments, terminal 100 may include one or N display screens 194, where N is a positive integer greater than one.

[0147] The terminal 100 can realize the shooting function through the ISP, camera 193, video codec, GPU, display screen 194 and application processor.

[0148] The ISP processes data fed back by camera 193. For example, when taking a photo, the shutter is opened, and light is transmitted through the lens to the camera's photosensitive element. The light signal is converted into an electrical signal, which is then passed to the ISP for processing and converted into a visible image. The ISP can also perform algorithmic optimization on image noise, brightness, and skin tone. It can also optimize parameters such as exposure and color temperature of the captured scene. In some embodiments, the ISP can be located within camera 193.

[0149] The camera 193 is used to capture still images or videos. The object generates an optical image through the lens and projects it onto the photosensitive element. The photosensitive element can be a charge coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) phototransistor. The photosensitive element converts the light signal into an electrical signal, and then passes the electrical signal to the ISP for conversion into a digital image signal. The ISP outputs the digital image signal to the DSP for processing. The DSP converts the digital image signal into an image signal in a standard RGB, YUV or other format. In some embodiments, the terminal 100 may include 1 or N cameras 193, where N is a positive integer greater than 1.

[0150] The digital signal processor is used to process digital signals. In addition to processing digital image signals, it can also process other digital signals. For example, when the terminal 100 selects a frequency point, the digital signal processor is used to perform Fourier transform on the frequency point energy.

[0151] Video codecs are used to compress or decompress digital video. Terminal 100 may support one or more video codecs. This allows terminal 100 to play or record videos in various encoding formats, such as Moving Picture Experts Group (MPEG) 1, MPEG2, MPEG3, and MPEG4.

[0152] The NPU is a neural network (NN) computing processor. Drawing on the structure of biological neural networks, such as the transmission patterns between neurons in the human brain, it rapidly processes input information and can continuously self-learn. The NPU enables intelligent cognitive applications in the terminal 100, such as image recognition, face recognition, speech recognition, and text comprehension.

[0153] The external memory interface 120 can be used to connect an external memory card, such as a Micro SD card, to expand the storage capacity of the terminal 100. The external memory card communicates with the processor 110 via the external memory interface 120 to implement data storage functions. For example, files such as music and videos can be stored on the external memory card.

[0154] The internal memory 121 can be used to store computer executable program codes, which include instructions. The processor 110 executes various functional applications and data processing of the terminal 100 by running the instructions stored in the internal memory 121. The internal memory 121 may include a program storage area and a data storage area. Among them, the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc. The data storage area can store data created during the use of the terminal 100 (such as audio data, a phone book, etc.), etc. In addition, the internal memory 121 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, a universal flash storage (UFS), etc.

[0155] The terminal 100 can implement audio functions such as music playback and recording through the audio module 170, the speaker 170A, the receiver 170B, the microphone 170C, the headphone jack 170D, and the application processor.

[0156] The audio module 170 is used to convert digital audio information into analog audio signal output, and is also used to convert analog audio input into digital audio signals. The audio module 170 can also be used to encode and decode audio signals. In some embodiments, the audio module 170 can be provided in the processor 110, or some functional modules of the audio module 170 can be provided in the processor 110.

[0157] The speaker 170A, also called a "horn", is used to convert an audio electrical signal into a sound signal. The terminal 100 can listen to music or listen to a hands-free call through the speaker 170A.

[0158] The receiver 170B, also called a "handset", is used to convert audio electrical signals into sound signals. When the terminal 100 receives a call or voice message, the voice can be heard by placing the receiver 170B close to the ear.

[0159] Microphone 170C, also known as "microphone" or "microphone", is used to convert sound signals into electrical signals. When making a call or sending a voice message, the user can speak by putting their mouth close to the microphone 170C to input the sound signal into the microphone 170C. The terminal 100 can be provided with at least one microphone 170C. In other embodiments, the terminal 100 can be provided with two microphones 170C, which can not only collect sound signals but also realize noise reduction function. In other embodiments, the terminal 100 can also be provided with three, four or more microphones 170C to realize sound signal collection, noise reduction, and identification of sound sources, and realize directional recording function, etc.

[0160] The headphone jack 170D is used to connect a wired headphone and can be the USB interface 130 or a 3.5mm open mobile terminal platform (OMTP) standard interface or a cellular telecommunications industry association of the USA (CTIA) standard interface.

[0161] Pressure sensor 180A is used to sense pressure signals and convert them into electrical signals. In some embodiments, pressure sensor 180A can be located on display screen 194. There are many types of pressure sensors 180A, such as resistive, inductive, and capacitive. A capacitive pressure sensor can include at least two parallel plates made of conductive material. When force is applied to pressure sensor 180A, the capacitance between the electrodes changes. Terminal 100 determines the intensity of the pressure based on this change in capacitance. When a touch operation is applied to display screen 194, terminal 100 detects the touch intensity based on pressure sensor 180A. Terminal 100 can also calculate the touch location based on the detection signal from pressure sensor 180A. In some embodiments, touch operations applied to the same touch location but with different touch intensities can correspond to different operation instructions. For example, when a touch operation with an intensity less than a first pressure threshold is applied to a short message application icon, a command to view short messages is executed. When a touch operation with an intensity greater than or equal to the first pressure threshold is applied to a short message application icon, a command to create a new short message is executed.

[0162] The gyroscope sensor 180B can be used to determine the motion posture of the terminal 100. In some embodiments, the angular velocity of the terminal 100 around three axes (i.e., x, y, and z axes) can be determined by the gyroscope sensor 180B. The gyroscope sensor 180B can be used for anti-shake shooting. For example, when the shutter is pressed, the gyroscope sensor 180B detects the angle of the terminal 100 shaking, calculates the distance that the lens module needs to compensate based on the angle, and allows the lens to offset the shaking of the terminal 100 through reverse movement to achieve anti-shake. The gyroscope sensor 180B can also be used for navigation and somatosensory game scenes.

[0163] The air pressure sensor 180C is used to measure air pressure. In some embodiments, the terminal 100 calculates the altitude using the air pressure value measured by the air pressure sensor 180C to assist in positioning and navigation.

[0164] The magnetic sensor 180D includes a Hall sensor. The terminal 100 can use the magnetic sensor 180D to detect the opening and closing of the flip case. In some embodiments, when the terminal 100 is a flip phone, the terminal 100 can detect the opening and closing of the flip cover based on the magnetic sensor 180D. Furthermore, based on the detected opening and closing status of the case or flip cover, features such as automatic unlocking of the flip cover can be configured.

[0165] Accelerometer 180E can detect the magnitude of acceleration of terminal 100 in all directions (generally three axes). When terminal 100 is stationary, it can detect the magnitude and direction of gravity. It can also be used to identify the electronic device's posture, enabling applications such as switching between landscape and portrait modes and pedometers.

[0166] The distance sensor 180F is used to measure distance. The terminal 100 can measure distance using infrared or laser. In some embodiments, when shooting a scene, the terminal 100 can use the distance sensor 180F to measure distance to achieve fast focusing.

[0167] The proximity light sensor 180G may include, for example, a light emitting diode (LED) and a light detector, such as a photodiode. The light emitting diode may be an infrared light emitting diode. The terminal 100 emits infrared light outward through the light emitting diode. The terminal 100 uses the photodiode to detect infrared reflected light from nearby objects. When sufficient reflected light is detected, it can be determined that there is an object near the terminal 100. When insufficient reflected light is detected, the terminal 100 can determine that there is no object near the terminal 100. The terminal 100 can use the proximity light sensor 180G to detect when the user holds the terminal 100 close to the ear to talk, so as to automatically turn off the screen to save power. The proximity light sensor 180G can also be used in leather case mode and pocket mode to automatically unlock and lock the screen.

[0168] Ambient light sensor 180L is used to sense ambient light brightness. Terminal 100 can adaptively adjust the brightness of display screen 194 based on the perceived ambient light brightness. Ambient light sensor 180L can also be used to automatically adjust white balance when taking photos. Ambient light sensor 180L can also work with proximity light sensor 180G to detect whether terminal 100 is in a pocket to prevent accidental touches.

[0169] The fingerprint sensor 180H is used to collect fingerprints. The terminal 100 can use the collected fingerprint characteristics to implement fingerprint unlocking, access application locks, fingerprint photography, fingerprint call answering, etc.

[0170] Temperature sensor 180J is used to detect temperature. In some embodiments, terminal 100 uses the temperature detected by temperature sensor 180J to implement a temperature handling strategy. For example, when the temperature reported by temperature sensor 180J exceeds a threshold, terminal 100 reduces the performance of a processor located near temperature sensor 180J to reduce power consumption and implement thermal protection. In other embodiments, when the temperature falls below another threshold, terminal 100 heats battery 142 to prevent abnormal shutdown of terminal 100 due to low temperature. In other embodiments, when the temperature falls below yet another threshold, terminal 100 boosts the output voltage of battery 142 to prevent abnormal shutdown due to low temperature.

[0171] The touch sensor 180K is also called a "touch panel." The touch sensor 180K can be disposed on the display screen 194. The touch sensor 180K and the display screen 194 form a touch screen, also called a "touch screen." The touch sensor 180K is used to detect touch operations applied thereto or in the vicinity thereof. The touch sensor can transmit the detected touch operations to the application processor to determine the type of touch event. Visual output related to the touch operations can be provided via the display screen 194. In other embodiments, the touch sensor 180K can also be disposed on the surface of the terminal 100, in a location different from that of the display screen 194.

[0172] The bone conduction sensor 180M can obtain vibration signals. In some embodiments, the bone conduction sensor 180M can obtain vibration signals from the vibrating bones of the human body. The bone conduction sensor 180M can also contact the human pulse to receive blood pressure pulse signals. In some embodiments, the bone conduction sensor 180M can also be set in headphones to form bone conduction headphones. The audio module 170 can parse out voice signals based on the vibration signals of the vibrating bones of the human body obtained by the bone conduction sensor 180M to implement voice functions. The application processor can parse heart rate information based on the blood pressure pulse signals obtained by the bone conduction sensor 180M to implement heart rate detection functions.

[0173] Keys 190 include a power button, a volume button, etc. Keys 190 may be mechanical keys or touch keys. Terminal 100 may receive key inputs and generate key signal inputs related to user settings and function control of terminal 100.

[0174] Motor 191 can generate vibration prompts. Motor 191 can be used for incoming call vibration prompts, and can also be used for touch vibration feedback. For example, touch operations acting on different applications (such as taking pictures, audio playback, etc.) can correspond to different vibration feedback effects. For touch operations acting on different areas of the display screen 194, motor 191 can also correspond to different vibration feedback effects. Different application scenarios (for example: time reminders, receiving messages, alarm clocks, games, etc.) can also correspond to different vibration feedback effects. The touch vibration feedback effect can also support customization.

[0175] The indicator 192 may be an indicator light, which may be used to indicate the charging status, power level changes, messages, missed calls, notifications, etc.

[0176] The SIM card interface 195 is used to connect a SIM card. The SIM card can be connected to or removed from the terminal 100 by inserting it into or removing it from the SIM card interface 195. The terminal 100 can support one or N SIM card interfaces, where N is a positive integer greater than one. The SIM card interface 195 can support Nano SIM cards, Micro SIM cards, SIM cards, and the like. Multiple cards can be inserted into the same SIM card interface 195 at the same time. The types of the multiple cards can be the same or different. The SIM card interface 195 can also be compatible with different types of SIM cards. The SIM card interface 195 can also be compatible with external memory cards. The terminal 100 interacts with the network through the SIM card to implement functions such as calls and data communications. 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.

[0177] The following describes a protocol encapsulation architecture for inbound data of a Beidou communication system 10 provided in an embodiment of the present application.

[0178] Figure 5 A schematic diagram of a protocol encapsulation architecture for inbound data of a Beidou communication system 10 provided in an embodiment of the present application is shown.

[0179] like Figure 5 As shown, the Beidou message transmission protocol layer on the terminal 100 can be divided into an application layer (application layer protocol), a message data convergence protocol (MDCP), a satellite link control protocol (SLC) and a physical layer (PHY).

[0180] When the terminal 100 sends data to the Beidou network device 200, the workflow of the Beidou message transmission protocol on the terminal 100 can be as follows:

[0181] At the APP layer, terminal 100 can compress the original data into compressed data using a compression algorithm and add a compression indication field to the front of the compressed data. The compression indication field can be used to indicate the compression algorithm type of the compressed data. Terminal 100 can then encrypt the compressed data to obtain encrypted data and add an encryption indication field to the header of the encrypted data. The encryption indication field is used to indicate the encryption algorithm type of the encrypted data. Terminal 100 can encapsulate the encrypted data, compression indication field, and encryption indication field into an application layer message and send it to the MDCP layer. The application layer message includes a message header and message data. The message header includes a compression indication field, an encryption indication field, and a service type field, among other fields. The message data includes the encrypted data.

[0182] Optionally, the terminal 100 may also encrypt the compression indication field and the compressed data together to obtain encrypted data.

[0183] At the MDCP layer, terminal 100 can obtain the application layer message sent by the APP layer through the inter-layer interface and treat the application layer message as an MDCP SDU. Due to air interface limitations, terminal 100 can only send physical frames of a specified length at the physical layer at a time. This constrains the length of the MDCP layer data to the specified length. Therefore, at the MDCP layer, terminal 100 can add padding data (padding) to the end of the MDCP SDU to a specified length and add a redundant length indication field to the header of the MDCP SDU. The redundant length indication field can be used to indicate the length of the padding data. Terminal 100 can split the padding data and the MDCP SDU after adding the redundant length indication field into one or more fixed-length MDCP segments (M_segments) and add a subsequent indication field to the header of each MDCP segment to obtain an MDCP PDU. That is, the MDCP PDU includes the M_segment and subsequent indication fields. The subsequent indication field may be used to indicate whether the current MDCP PDU is the starting MDCP PDU, the middle MDCP PDU or the last MDCP PDU among a plurality of MDCP PDUs sent continuously; or, it is a separately sent MDCP PDU.

[0184] At the SLC layer, the terminal 100 can obtain the MDCP PDU sent by the MDCP layer through the inter-layer interface as an SLC SDU. At the SLC layer, the terminal 100 can segment the SLC SDU into one or more (up to 4) fixed-length SLC segments (S_segments) and add frame header information to the header of each S_segment to obtain an SLC PDU. The frame header information includes the service data unit alternated indicator (SAI) field, the total number of frames field, and the frame sequence number field.

[0185] The SAI field may be used to indicate whether the SLC PDU belongs to an unsent SLC SDU.

[0186] The total number of frames field can be used to indicate the total number of SLC PDUs included in the SLC SDU to which the SLC PDU belongs.

[0187] The frame sequence number field can be used to indicate the sequence number of the SLC PDU in the SLC SDU to which it belongs.

[0188] At the PHY layer, the terminal 100 can obtain the SLC PDU sent by the SLC layer through the inter-layer interface as the code block of the PHY layer, and add a synchronization header to the head of the code block and a check bit field to the tail of the code block. In the above-mentioned Beidou communication system 10, a cyclic redundancy check (CRC) can be used to check the code block, so the check bit field can include a CRC code. The terminal 100 can encode the code block and the check bit field (for example, polar coding) to obtain coded data, and then insert a pilot into the coded data to obtain pilot coded data (pilot+data). Then, the terminal 100 modulates the synchronization header and pilot coded data in sequence through the underlying hardware to obtain modulated data (modulateddata). The terminal 100 can spread the modulated data to obtain spread spectrum modulated data (spread+modulateddata). The terminal 100 can send the spread spectrum modulated data to the Beidou short message satellite 21, which is relayed to the Beidou network device 200 via the Beidou short message satellite 21.

[0189] The following describes a protocol parsing architecture for inbound data of a Beidou communication system 10 provided in an embodiment of the present application.

[0190] Figure 6A schematic diagram of a protocol parsing architecture for inbound data of a Beidou communication system 10 provided in an embodiment of the present application is shown.

[0191] like Figure 6 As shown, the BeiDou short message transmission protocol layer of the BeiDou network device 200 can be divided into an application layer protocol, a message data convergence protocol (MDCP), a satellite link control protocol (SLC), and a physical layer protocol (PHY). Among them, the BeiDou network device 200 can include a BeiDou ground transceiver station 22, a BeiDou central station 23, and a BeiDou short message fusion communication platform 24. The BeiDou ground transceiver station 22 can be used to be responsible for the protocol processing of the PHY layer. The BeiDou central station 23 can be used to be responsible for the protocol processing of the SLC layer and the MDCP layer. The BeiDou short message fusion communication platform 24 can be used to be responsible for the protocol processing of the APP layer.

[0192] When the BeiDou network device 200 receives data sent by the terminal 100, the workflow of the BeiDou short message transmission protocol layer of the BeiDou network device 200 may be as follows:

[0193] At the PHY layer, the Beidou network device 200 can obtain the pilot coded data after modulation and spread spectrum sent by the terminal 100. The Beidou network device 200 can despread the received spread spectrum modulated data (spread+modulateddata) to obtain modulated data (modulateddata). Then, the Beidou network device 200 can demodulate the modulated data to obtain pilot coded data (pilot+data). Next, the Beidou network device 200 removes the pilot information in the pilot coded data to obtain coded data (codedata). Then, the Beidou network device 200 can decode the coded data and verify the integrity of the coded block (codeblock) through the check data in the check bit field. If complete, the Beidou network device 200 can extract the coded block (codeblock) and present it to the SLC layer through the inter-layer interface as the SLC PDU of the SLC layer.

[0194] At the SLC layer, the BeiDou network device 200 can concatenate SLC PDUs belonging to the same SLC SDU into one SLC SDU based on the frame header information of the SLC PDU. The BeiDou network device 200 can present the SLC SDU to the MDCP layer through the inter-layer interface as an MDCP PDU of the MDCP layer.

[0195] At the MDCP layer, the BeiDou network device 200 can concatenate all MDCP PDUs belonging to the same MDCP SDU into one MDCP SDU. The BeiDou network device 200 can present the MDCP SDU to the APP layer through the inter-layer interface as an application layer message received by the APP layer.

[0196] At the APP layer, the Beidou network device 200 can decrypt and decompress the application layer message based on the message header of the application layer message to obtain the original data.

[0197] In the embodiments of the present application, the above-mentioned protocol processing process is only an example, and the present application does not limit the specific operations of the protocol processing.

[0198] The following describes a protocol encapsulation architecture for outbound data of a Beidou communication system 10 provided in an embodiment of the present application.

[0199] Figure 7 A schematic diagram of a protocol encapsulation architecture for outbound data of a Beidou communication system 10 provided in an embodiment of the present application is shown.

[0200] like Figure 7 As shown, the BeiDou short message transmission protocol layer in the BeiDou network device 200 can be divided into the APP layer, the MDCP layer, the SLC layer, and the PHY layer. Specifically, the BeiDou network device 200 can include a BeiDou ground transceiver station 22, a BeiDou central station 23, and a BeiDou short message fusion communication platform 24. The BeiDou ground transceiver station 22 can be responsible for protocol processing at the PHY layer. The BeiDou central station 23 can be responsible for protocol processing at the SLC and MDCP layers. The BeiDou short message fusion communication platform 24 can be responsible for protocol processing at the APP layer.

[0201] When the Beidou network device 200 sends data to the terminal 100, the workflow of the Beidou short message transmission protocol in the Beidou network device 200 may be as follows:

[0202] At the APP layer, the Beidou network device 200 may compress the original data into compressed data using a compression algorithm and prepend a compression indicator field to the compressed data. The compression indicator field may be used to indicate the compression algorithm type used for the compressed data. The Beidou network device 200 may then encrypt the compressed data to obtain encrypted data and add an encryption indicator field to the header of the encrypted data. The encryption indicator field indicates the encryption algorithm type used for the encrypted data. The Beidou network device 200 may 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. The application layer message may include a message header and message data. The message header may include a compression indicator field, an encryption indicator field, and a service type field, among other fields. The message data includes the encrypted data.

[0203] Optionally, the Beidou network device 200 may also encrypt the compression indication field and the compressed data together to obtain encrypted data.

[0204] At the MDCP layer, the Beidou network device 200 can obtain the application layer message sent by the APP layer through the inter-layer interface and use the application layer message as an MDCP SDU. At the MDCP layer, the Beidou network device 200 can split an MDCP SDU into one or more fixed-length MDCP segment data (M_segment) and add a successor indication field to the header of each MDCP segment data to obtain an MDCP PDU. That is, the MDCP PDU includes an M_segment and a successor indication field. The successor indication field can be used to indicate whether the current MDCP PDU is the starting MDCP PDU, an intermediate MDCP PDU, or the last MDCP PDU of multiple MDCP PDUs sent continuously; or a single MDCP PDU sent separately.

[0205] At the SLC layer, the BeiDou network device 200 can obtain the MDCP PDU sent by the MDCP layer through the inter-layer interface as an SLC SDU. At the SLC layer, the BeiDou network device 200 can segment the SLC SDU into one or more (up to 4) fixed-length SLC segment data (S_segments) and add frame header information to the header of each S_segment to obtain an SLC PDU.

[0206] At the PHY layer, the Beidou network device 200 can obtain the SLC PDU sent by the SLC layer through the inter-layer interface. The Beidou network device 200 can obtain the SLC PDU of one or more users from the SLC layer. The Beidou network device 200 can splice the SLC PDUs of multiple users together, add the frame header of the physical frame (such as the version number) as the code block of the PHY layer, and add a check bit (such as a cyclic redundancy check (CRC) code) at the end of the code block, and encode the code block and CRC code (such as polar coding). The encoded physical frame plus the reserved segment can form the coded data of the message branch (S2C_d branch) of a fixed-length physical time slot. Among them, the Beidou network device 200 can put multiple SLC PDUs of a user into different physical frames respectively. Then, the Beidou network device 200 combines the coded data of the S2C_d branch and the pilot information of the pilot branch (S2C_p branch) to form pilot coded data, that is, outbound data. The Beidou network device 200 can send outbound data to the Beidou short message satellite 21, which is then relayed to the terminal 100 via the Beidou short message satellite 21.

[0207] It is understood that 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 need to be decoded. However, the encoded data of the S2C_d branch needs to be decoded.

[0208] The following describes a protocol parsing architecture for outbound data of a Beidou communication system 10 provided in an embodiment of the present application.

[0209] Figure 8 A schematic diagram of a protocol parsing architecture for outbound data of a Beidou communication system 10 provided in an embodiment of the present application is shown.

[0210] like Figure 8 As shown, the Beidou short message transmission protocol layer of the terminal 100 can be divided into an APP layer, an MDCP layer, an SLC layer and a PHY layer.

[0211] When the terminal 100 receives data sent by the Beidou network device, the workflow of the Beidou short message transmission protocol layer of the terminal 100 can be as follows:

[0212] At the PHY layer, the terminal 100 can obtain the pilot coded data after modulation and spread spectrum sent by the Beidou network device 200. The terminal 100 can despread the received spread spectrum modulated data (spread+modulated data) to obtain modulated data (modulated data). Then, the terminal 100 can demodulate the modulated data to obtain pilot coded data (pilot+data). Then, the terminal 100 can remove the pilot information in the pilot coded data to obtain coded data (code data). Then, the terminal 100 can decode the coded data and verify the integrity of the code block (code block) through the check data in the check bit field. If complete, the terminal 100 can extract the code block (code block) and present it to the SLC layer through the inter-layer interface as the SLC PDU of the SLC layer.

[0213] Here, the pilot coded data is the outbound data sent by the Beidou network device 200, and the outbound data consists of the coded data of the S2C_d branch and the pilot information of the pilot branch (S2C_p branch).

[0214] At the SLC layer, the terminal 100 can concatenate SLC PDUs belonging to the same SLC SDU into one SLC SDU based on the frame header information of the SLC PDU. The terminal 100 can present the SLC SDU to the MDCP layer through the inter-layer interface as an MDCP PDU of the MDCP layer.

[0215] At the MDCP layer, the terminal 100 may concatenate all MDCP PDUs belonging to the same MDCP SDU into one MDCP SDU. The terminal 100 may present the MDCP SDU to the APP layer via an inter-layer interface as an application layer message received by the APP layer.

[0216] At the APP layer, the terminal 100 may decrypt and decompress the application layer message based on the message header of the application layer message to obtain the original data.

[0217] In the embodiments of the present application, the above-mentioned protocol processing process is only an example, and the present application does not limit the specific operations of the protocol processing.

[0218] The following introduces two feedback modes of the SLC layer in the Beidou communication system provided in the embodiments of the present application.

[0219] (1) Stop and wait feedback mode.

[0220] Figure 9 A schematic diagram of a stop-and-wait feedback mode of an SLC layer provided in an embodiment of the present application is exemplarily shown.

[0221] like Figure 9 As shown in FIG, in the stop-and-wait feedback mode, the transmitter can wait for an ACK frame from the receiver after sending an SLC PDU to the receiver. After receiving the ACK frame from the receiver, the transmitter can send the next SLC PDU to the receiver.

[0222] For example, the transmitting end may send the i-th SLC PDU to the receiving end. After receiving the i-th SLC PDU, the receiving end may return an ACK frame to the transmitting end. After receiving the ACK frame, the transmitting end may send the i+1-th SLC PDU to the receiving end. After receiving the i+1-th SLC PDU, the receiving end may return an ACK frame to the transmitting end. After receiving the ACK frame, the transmitting end may send the i+2-th SLC PDU to the receiving end. After receiving the i+2-th SLC PDU, the receiving end may return an ACK frame to the transmitting end.

[0223] Among them, when the sending end is the terminal 100 in the above-mentioned Beidou communication system 10, the receiving end can be the Beidou network device 200 in the above-mentioned Beidou communication system 10. When the sending end is the Beidou network device 200 in the above-mentioned Beidou communication system 10, the receiving end can be the terminal 100 in the above-mentioned Beidou communication system 10.

[0224] In the stop-and-wait feedback mode, the receiving end can immediately feedback ACK after receiving an SLC PDU. This ensures that the sending end can receive feedback in a timely manner, reduces the transmission delay and scheduling delay, and reduces the risk of feedback information transmission failure.

[0225] (2) Parallel feedback mode.

[0226] Figure 10 A schematic diagram of a parallel feedback mode of an SLC layer provided in an embodiment of the present application is exemplarily shown.

[0227] like Figure 10 As shown in Figure 1, in parallel feedback mode, the transmitter can continuously send a group of SLC PDUs to the receiver, where each group of SLC PDUs includes N SLC PDUs. After continuously sending N SLC PDUs to the receiver, the transmitter can wait for an ACK frame from the receiver. After receiving the group of SLC PDUs sent by the transmitter, the receiver can return an ACK frame to the receiver. After receiving the ACK frame from the receiver, the transmitter can send the next group of SLC PDUs.

[0228] Among them, when the sending end is the terminal 100 in the above-mentioned Beidou communication system 10, the receiving end can be the Beidou network device 200 in the above-mentioned Beidou communication system 10. When the sending end is the Beidou network device 200 in the above-mentioned Beidou communication system 10, the receiving end can be the terminal 100 in the above-mentioned Beidou communication system 10.

[0229] In parallel feedback mode, the receiver can only send back an ACK frame after receiving a group of SLC PDUs. This saves the receiver's signaling overhead compared to the stop-and-wait feedback mode because the receiver only sends an ACK frame after sending multiple SLC PDUs.

[0230] The advantages and disadvantages of the above-mentioned stop-and-wait feedback mode and parallel feedback mode can be shown in the following Table 1:

[0231] Table 1

[0232]

[0233]

[0234] It can be seen from Table 1 above that:

[0235] 1. The stop-and-wait feedback mode requires the receiving end to immediately send feedback information to the transmitting end after receiving the SLC PDU sent by the transmitting end. The parallel feedback mode requires the receiving end to delay receiving the SLC PDU sent by the transmitting end and accumulate a certain amount of SLC PDUs before sending feedback information to the transmitting end. Due to hardware limitations of terminal 100 and Beidou network device 200, the downlink SLC PDU transmission interval is relatively long (for example, greater than 2 seconds). Therefore, this transmission interval can be used to allow terminal 100 to send feedback information to Beidou network device 200.

[0236] 2. In the stop-and-wait feedback mode, the receiver does not need to maintain a complex receiving state machine, and the processing at the receiver is relatively simple. In the parallel feedback mode, the receiver needs to maintain a complex receiving state machine, and the processing process is complicated.

[0237] 3. In the stop-and-wait feedback mode, the feedback signaling overhead is relatively high, but it can be adapted to different user link qualities. The transmitter can adjust the SLC PDU transmission method in a timely manner according to the user link quality.

[0238] 4. In parallel feedback mode, the receiving state machine at the receiving end needs to set a waiting time based on the number of SLC PDUs sent by the transmitting end. Therefore, the total number of SLC PDU frames limits the number of data frames transmitted in one SLC layer session. In stop-and-wait feedback mode, the receiving end immediately sends feedback information to the transmitting end after receiving an SLC PDU. Therefore, the receiving end does not need to set a waiting timer. Since the transmitting end waits for the ACK from the receiving end after sending each SLC PDU, the transmitting RF device at the transmitting end has sufficient rest time, and the number of SLC PDUs sent by the transmitting end at the SLC layer is not limited.

[0239] The following describes the process of the terminal 100 and the Beidou network device 200 negotiating the feedback mode in an embodiment of the present application.

[0240] Figure 11 A schematic diagram of the frame format of an inbound SLC PDU provided in an embodiment of the present application is shown.

[0241] like Figure 11 As shown, upon inbound, the frame header information of the SLC PDU sent by the terminal 100 to the Beidou network device 200 may include: version number field, subtype indication field, user ID field, confirmation mode enable (AM enable) field, total number of frames field, frame sequence number field, SAI field and reserve (RSV) field.

[0242] The version number field can be used to indicate the version of the BeiDou communication protocol. This field can support the evolution of the BeiDou communication protocol format for each frame type. The length of the version number field can be 3 bits. This embodiment of the application does not limit the length of the version number field.

[0243] The subtype field can be used to indicate that the frame type of the user frame sent by the terminal 100 is a general data frame, namely, SLC PDU. The length of the subtype field can be 1 bit. For example, the value of the subtype field is "0", indicating that the user frame is a general data frame, namely, SLC PDU. When the value of the subtype field is "1", it indicates that the user frame sent by the terminal 100 is an ACK frame. Since the SLC PDU is a general data frame sent by the terminal 100, the subtype field in the SLC PDU takes the value of "0". The embodiment of the present application does not limit the length of the subtype field.

[0244] The user ID field can be used to indicate the device identification of the terminal 100 in the Beidou communication system. The length of the user ID field can be 44 bits. The embodiment of the present application does not limit the length of the user ID field.

[0245] The AMenable field can be used to indicate whether the terminal 100 adopts the confirmation mode to transmit the SLC PDU. The length of the AMenable field can be 1 bit. If the value in the AM enable field is the first value (for example: 1), it indicates that the Beidou network device 200 needs to reply ACK to the terminal 100 after receiving the SLC PDU sent by the terminal 100. If the value in the AM enable field is the second value (for example: 0), it indicates that the Beidou network device 200 does not need to reply ACK to the terminal 100 after receiving the SLC PDU. The embodiment of the present application does not limit the length of the AM enable field and the specific value of the AM enable field.

[0246] For example, when the value of the AMenable field is "1", it indicates that the terminal 100 adopts the confirmation mode transmission, and the Beidou network device 200 is required to reply with an ACK frame after receiving the SLC PDU sent by the terminal 100. When the value of the AMenable field is "0", it indicates that the terminal 100 adopts the non-confirmation mode transmission, and the Beidou network device 200 is required not to reply with an ACK frame after receiving the SLC PDU.

[0247] The Total Frames field may be used to indicate the total number of SLC PDUs included in the SLC SDU to which the SLC PDU belongs. The Total Frames field may be 2 bits long. When the Total Frames field is 2 bits long, a SLC PDU may include a maximum of 4 SLC PDUs.

[0248] The frame sequence number field can be used to indicate the sequence number of the SLC PDU in an SLC SDU. The length of the frame sequence number field can be 2 bits. The embodiment of the present application does not limit the length of the frame sequence number field.

[0249] The service data unit alternated indicator (SAI) field can occupy 1 bit. When the terminal 100 transmits the SLC PDU in confirmed mode, that is, the value of the AM-enable field is "1", the SAI field can be used to indicate whether the SLC PDU is a retransmitted SLC PDU. When the terminal 100 transmits the SLC PDU in unconfirmed mode, that is, the value of the AM-enable field is "0", the SAI field can be reserved for other functions.

[0250] The RSV field can occupy 4 bits and can be reserved for other functions.

[0251] It is understandable that Figure 12 The frame format of the outbound SLC PDU is shown only as an example. The embodiment of the present application does not limit the arrangement order of the cell parameters in the frame header information field.

[0252] Figure 12 A schematic diagram of a frame format of an outbound SLC PDU provided in an embodiment of the present application is shown.

[0253] like Figure 12 As shown, when outbound, the frame header information of the SLC PDU sent by the Beidou network device 200 to the terminal 100 may include: frame type field, acknowledgement mode enable (AM enable) field, frame length field, user ID field, total number of frames field and frame sequence number field.

[0254] The frame type field may be used to indicate the type of the SLC frame. The length of the frame type field may be 2 bits. The embodiment of the present application does not limit the length of the frame type field.

[0255] The AM enable field indicates whether the Beidou network device 200 uses the confirmation mode to transmit the SLC PDU. The length of the AMenable field can be 1 bit. If the value in the AM enable field is the first value (for example: 1), it indicates that the terminal 100 needs to reply ACK to the Beidou network device 200 after receiving the SLC PDU sent by the Beidou network device 200. If the value in the AM enable field is the second value (for example: 0), it indicates that the terminal 100 does not need to reply ACK to the Beidou network device 200 after receiving the SLC PDU from the Beidou network device 200. The embodiment of the present application does not limit the length of the AM enable field and the specific value of the AM enable field.

[0256] For example, when the value of the AMenable field is "1", it indicates that the Beidou network device 200 adopts the confirmation mode transmission, requiring the terminal 100 to reply ACK after receiving the SLC PDU sent by the Beidou network device 200. When the value of the AM-enable field is "0", it indicates that the Beidou network device 200 adopts the non-confirmation mode transmission, requiring the terminal 100 not to reply ACK after receiving the SLC PDU sent by the Beidou network 200.

[0257] The frame length field is used to identify the length of the SLC frame, and the length of the frame length field can be 8 bits. The embodiment of the present application does not limit the length of the frame length field.

[0258] The User ID field can be used to indicate that the SLCPDU is sent from the Beidou network device 200 to the terminal 100, and the ID of the terminal 100 is the same as the ID shown in the User ID field. The length of the User ID field can be 34 bits. The embodiment of the present application does not limit the length of the User ID field.

[0259] The Total Frames field may be used to indicate the total number of SLC PDUs included in the SLC SDU to which the SLC PDU belongs. The Total Frames field may be 2 bits long. When the Total Frames field is 2 bits long, a SLC PDU may include a maximum of 4 SLC PDUs.

[0260] The frame sequence number field can be used to indicate the sequence number of the SLC PDU in an SLC SDU. The length of the frame sequence number field can be 2 bits. The embodiment of the present application does not limit the length of the frame sequence number field.

[0261] It is understandable that Figure 12 The frame format of the outbound SLC PDU is shown only as an example. The embodiment of the present application does not limit the arrangement order of the cell parameters in the frame header information field.

[0262] Generally speaking, in the parallel confirmation mode, the transmitter sends a group (N) of SLC PDUs belonging to an SLC SDU to the receiver. After receiving this group of SLC PDUs, the receiver needs to determine whether all the SLC PDUs in this group of SLC PDUs are received based on the frame sequence number and total number of frames in the frame header information of this group of SLC PDUs. The receiver can return a corresponding ACK to the transmitter based on the completeness of this group of SLC PDUs. Among them, in the parallel confirmation mode, the frame sequence number of a group of SLC SDUs will not be greater than the total number of frames in this group of SLC PDUs. However, the permutations and combinations of the values of the frame sequence number field and the total number of frames field in the frame header information of the SLC PDU include both the value of the frame sequence number being less than or equal to the total number of frames and the value of the frame sequence number being greater than the total number of frames.

[0263] For example, the length of the frame sequence number field can be 2 bits, and the length of the total number of frames field can be 2 bits. Therefore, there are 16 permutations and combinations of the frame sequence number field value and the total number of frames field value. Among them, there are 10 combinations in which the frame sequence number field value is less than or equal to the total number of frames field value, and 6 combinations in which the frame sequence number field value is greater than the total number of frames field value. Therefore, in the parallel confirmation mode, only 10 of the 16 permutations and combinations of the frame sequence number field value and the total number of frames field value are used, leaving 6 remaining. The above examples are only used to explain this application and should not constitute a limitation.

[0264] In stop-and-wait confirmation mode, since the receiving end returns an ACK to the sending end upon receiving an SLC PDU, it does not need to know the frame sequence number of the SLC PDU in the SLC SDU or the total number of SLC PDU frames in the SLC SDU. In stop-and-wait confirmation mode, the total number of frames and frame sequence number in the frame header information of the SLC PDU are not required. Therefore, in an embodiment of the present application, the combination of the value of the frame sequence number field in the frame header information of the SLC PDU being greater than the value of the total number of frames field can be used to indicate that the SLC PDU sent by the sending end requires the receiving end to return an ACK using the stop-and-wait confirmation mode.

[0265] Therefore, the sender can negotiate the confirmation mode with the receiver through the total number of frames field and the frame sequence number field in the frame header information of the data frame. In this way, no additional frame header overhead is added when the sender and the receiver negotiate the confirmation mode.

[0266] For example, the length of the frame sequence number field can be 2 bits, and the length of the total number of frames field can be 2 bits. The combination of the frame sequence number field value and the total number of frames field value can be defined as shown in Table 2 below:

[0267] Table 2

[0268]

[0269]

[0270] As shown in Table 2 above:

[0271] 1. The value of the total number of frames field and the value of the frame sequence number field of the SLC PDU are "0", which together indicate that the SLC PDU is the only SLC PDU in the SLC SDU. The receiving end does not need to distinguish between the stop-and-wait feedback mode and the parallel feedback mode and directly returns an ACK after receiving the SLC PDU.

[0272] 2. The value of the total number of frames field of the SLC PDU is "0", and the value of the frame sequence number field is "1", which can be combined to indicate that the SLC PDU is the first SLC PDU in the SLC SDU in the stop-and-wait feedback mode. Among them, the receiving end immediately feeds back ACK after receiving the SLC PDU and waits for the next SLC PDU. If the receiving end still does not receive the SLCPDU after the time required for the maximum number of retransmissions exceeds, the receiving end can end the SLC SDU session. If the sending end does not receive an ACK returned by the receiving end after the number of retransmissions of the SLC PDU reaches the maximum number, the SLC layer session is ended.

[0273] 3. The value of the Total Frames field of the SLC PDU is "0" and the value of the Frame Sequence Number field is "2". This combination indicates that this SLC PDU is the second SLC PDU in the stop-and-wait feedback mode, or the next SLC PDU after the SLC PDU with [Total Frames, Frame Sequence Number] of [0, 3]. The receiving end immediately returns an ACK after receiving this SLC PDU and waits for the next SLC PDU.

[0274] 4. The value of the Total Frames field of the SLC PDU is "0" and the value of the Frame Sequence Number field is "3", which together indicate that this SLC PDU is the next SLC PDU after the SLC PDU with [Total Frames, Frame Sequence Number] of [0, 2]. The receiving end immediately responds with an ACK after receiving this SLC PDU and waits for the next SLC PDU.

[0275] 5. The value of the SLC PDU's total number of frames field is "1" and the value of the frame sequence number field is "2", which together indicate the last SLC PDU in stop-and-wait feedback mode. Upon receiving this SLC PDU, the receiver immediately returns an ACK and terminates the SLC layer session.

[0276] 6. The value of the Total Frames field of the SLC PDU is "1" and the value of the Frame Sequence Number field is "0", which can be combined to indicate the first SLC PDU of a total of two SLC PDUs in the parallel feedback mode. After receiving this SLC PDU, the receiving end can feedback an ACK in parallel feedback mode.

[0277] 7. The value of the total number of frames field and the value of the frame sequence number field of the SLC PDU are "1", which can be combined to indicate the second SLC PDU of a total of two SLC PDUs in the parallel feedback mode. After receiving this SLC PDU, the receiving end can feedback ACK in parallel feedback mode.

[0278] 8. The value of the Total Frames field of the SLC PDU is "2" and the value of the Frame Sequence Number field is "0", which can be combined to indicate the first SLC PDU of a total of three SLC PDUs in the parallel feedback mode. After receiving this SLC PDU, the receiving end can feedback an ACK in parallel feedback mode.

[0279] 9. The value of the Total Frames field of the SLC PDU is "2" and the value of the Frame Sequence Number field is "1", which can be combined to indicate the second SLC PDU of a total of three SLC PDUs in the parallel feedback mode. After receiving this SLC PDU, the receiving end can feedback an ACK in parallel feedback mode.

[0280] 10. The value of the Total Frames field and the value of the Frame Sequence Number field of the SLC PDU are "2", which together represent the third SLC PDU of a total of three SLC PDUs in the parallel feedback mode. After receiving this SLC PDU, the receiving end can feedback an ACK in the parallel feedback mode.

[0281] 11. The value of the Total Frames field of the SLC PDU is "3" and the value of the Frame Sequence Number field is "0", which can be combined to indicate the first SLC PDU of a total of four SLC PDUs in the parallel feedback mode. After receiving this SLC PDU, the receiving end can feedback an ACK in parallel feedback mode.

[0282] 12. The value of the Total Frames field of the SLC PDU is "3" and the value of the Frame Sequence Number field is "1", which can be combined to indicate the second SLC PDU of a total of four SLC PDUs in the parallel feedback mode. After receiving this SLC PDU, the receiving end can feedback an ACK in parallel feedback mode.

[0283] 13. The value of the Total Frames field of the SLC PDU is "3" and the value of the Frame Sequence Number field is "2", which together represent the third SLC PDU of a total of four SLC PDUs in the parallel feedback mode. After receiving this SLC PDU, the receiving end can feedback an ACK in parallel feedback mode.

[0284] 14. The value of the Total Frames field and the Frame Sequence Number field of the SLC PDU are "3", which together represent the fourth SLC PDU of a total of four SLC PDUs in parallel feedback mode. After receiving this SLC PDU, the receiving end can feedback an ACK in parallel feedback mode.

[0285] 15. The value of the SLC PDU's total number of frames field is "1" and the value of the frame sequence number field is "3", which is an invalid value combination. If the receiving end receives this SLC PDU, it will directly discard it.

[0286] 16. The value of the Total Frames field of the SLC PDU is "2", and the value of the Frame Sequence Number field is "3", which is an invalid value combination. If the receiving end receives this SLC PDU, it shall discard it directly.

[0287] Among them, when transmitting an intermediate SLC PDU (not the first and last SLC PDU), the flipping of the combined value of the total number of frames field and the frame sequence number field of the two adjacent intermediate SLC PDUs can be used to indicate whether the intermediate SLC PDU is a retransmitted SLC PDU. If the combined value of the total number of frames field and the frame sequence number field of the latter SLC PDU is the same as the combined value of the total number of frames field and the frame sequence number field of the previous SLC PDU (that is, not flipped), then the latter SLC PDU is a retransmitted SLC PDU of the previous SLC PDU. For example, the flipping of two adjacent newly transmitted intermediate SLC PDUs can be indicated by the combined values of [total number of frames, frame sequence number]: [0, 2] and [0, 3].

[0288] Exemplarily, the transmitter can use the total number of frames field and the frame sequence number field in the SLC PDU to instruct the receiver to reply with an ACK in the stop-and-wait confirmation mode. The transmitter 0 can wait for the receiver to reply with an ACK each time it sends an SLC PDU. In the stop-and-wait confirmation mode transmission process, the total number of frames field value of the first SLC PDU sent by the terminal 100 is "0" and the frame sequence number field value is "1". The total number of frames field value of the second SLC PDU sent by the transmitter is "0" and the frame sequence number field value is "2". The total number of frames field value of the third SLC PDU sent by the transmitter is "0" and the frame sequence number field value is "3". The total number of frames field value of the fourth SLC PDU sent by the transmitter is "0" and the frame sequence number field value is "2". The total number of frames field value of the fifth SLC PDU sent by the transmitter is "0" and the frame sequence number field value is "3". The total number of frames field value of the sixth SLC PDU sent by the transmitter is "0" and the frame sequence number field value is "2". The total number of frames field value of the last SLC PDU sent by the transmitter is "1" and the frame sequence number field value is "2".

[0289] In the above example, when the transmitting end is the terminal 100, the receiving end may be the Beidou network device 200. When the transmitting end is the Beidou network device 200, the receiving end may be the terminal 100. The above example is only used to explain the present application and should not be construed as limiting.

[0290] For example, the transmitter can use the total number of frames field and the frame sequence number field in the SLC PDU to instruct the receiver to reply with an ACK in parallel acknowledgment mode. In parallel acknowledgment mode transmission, the transmitter needs to continuously transmit N SLC PDUs in the SLC SDU at intervals before waiting for the receiver to reply with an ACK.

[0291] When N=1, the total number of frames field value and the frame sequence number field value of the only SLC PDU in the SLC SDU are "0" and "0".

[0292] When N=2, the total number of frames field value of the first SLC PDU in the SLC SDU is "1" and the frame sequence number field value is "0". The total number of frames field value of the second SLC PDU in the SLC SDU is "1" and the frame sequence number field value is "1".

[0293] When N=3, the value of the total number of frames field of the first SLC PDU in the SLC SDU is "2", and the value of the frame sequence number field is "0". The value of the total number of frames field of the second SLC PDU in the SLC SDU is "2", and the value of the frame sequence number field is "1". The value of the total number of frames field of the third SLC PDU in the SLC SDU is "2", and the value of the frame sequence number field is "2".

[0294] When N=4, the value of the total number of frames field of the first SLC PDU in the SLC SDU is "3" and the value of the frame sequence number field is "0". The value of the total number of frames field of the second SLC PDU in the SLC SDU is "3" and the value of the frame sequence number field is "1". The value of the total number of frames field of the third SLC PDU in the SLC SDU is "3" and the value of the frame sequence number field is "2". The value of the total number of frames field of the fourth SLC PDU in the SLC SDU is "3" and the value of the frame sequence number field is "3".

[0295] In the above example, when the transmitting end is the terminal 100, the receiving end may be the Beidou network device 200. When the transmitting end is the Beidou network device 200, the receiving end may be the terminal 100. The above example is only used to explain the present application and should not be construed as limiting.

[0296] The following describes the SLC layer's stop-and-wait confirmation mode processing sequence when data is incoming in the Beidou communication system 10 provided in an embodiment of the present application.

[0297] Figure 13 A processing sequence diagram of a stop-and-wait confirmation mode of the SLC layer when data is inbound provided in an embodiment of the present application is shown.

[0298] like Figure 13 As shown, the Beidou communication system 10 may have a stop-and-wait confirmation mode interaction process when data is incoming as follows:

[0299] 1. The terminal 100 may encapsulate the total number of frames field and the frame sequence number field in the frame header information of the i-th SLC PDU according to the protocol rules of the stop-and-wait confirmation mode in Table 2 above.

[0300] 2. After sending the i-th SLC PDU to the Beidou network device 200, the terminal 100 may switch the RF hardware from the transmit (Tx) state to the receive (Rx) state. After switching to the receive (Rx) state, the terminal 100 may wait to receive an ACK returned by the Beidou network device 200 within the ACK receive window.

[0301] 3. After receiving the i-th SLC PDU sent by terminal 100, Beidou network device 200 can determine that terminal 100 requests an ACK based on the AM enable field, total number of frames field, and frame sequence number field in the frame header of the i-th SLC PDU, and then respond with an ACK using the stop-and-wait confirmation mode. Therefore, Beidou network device 200 can return an ACK to terminal 100 after the signal processing schedule has expired. The bitmap portion of the ACK is only 1 bit long. This 1-bit bitmap in the ACK can be used to indicate that Beidou network device 200 has received the i-th SLC PDU.

[0302] 4. The terminal 100 can determine the start time (tUeStartRcvAck) and the end time (tUeEndRcvAck) of the ACK reception window based on the time length (tUeUlFrameLen) of the physical frame sent by the terminal 100, the switching duration from the transmission state to the reception state (tTx2RxSwitch), the switching duration from the reception state to the transmission state (tRx2TxSwitch), the radio propagation delay (tPropagate), the signal processing and scheduling delay (tStationProcess) of the Beidou network device 200, the time alignment deviation (δ) of the physical frame sent by the Beidou network device 200, and the time length (tStationDlFrameLen) of the physical frame sent by the Beidou network device 200.

[0303] Among them, in the stop-and-wait acknowledgment mode, it is necessary to ensure that the ACK reception window of the terminal 100 is already open before the ACK arrives at the terminal 100. Therefore, assuming that the starting point of the terminal 100 sending the SLC PDU is the 0 moment, the terminal 100 can determine the start time (tUeStartRcvAck) of the ACK reception window through the following formula (1):

[0304] t0 + tUeUlFrameLen + tTx2RxSwitch < tUeStartRcvAck < t0 + tUeUlFrameLen + 2 * tPropagate + tStationProcess Formula (1)

[0305] Among them, in Formula (1), the value of tStationProcess takes the minimum value (t_MinStatProc). Through experimental data measurement, the value of t_MinStatProc can be 1 s, and the typical value of tPropagate can be 270 ms.

[0306] The terminal 100 can determine the end time (tUeEndRcvAck) of the ACK reception window through the following formula (2):

[0307] tUeEndRcvAck = t0 + UeUlFrameLen + tPropagate * 2 + tStationProcess + tStationDlFrameLen + δ Formula (2)

[0308] In formula (2), the value of tStationProcess can be the maximum value (t_MaxStatProc), for example, 4s. According to experimental data, the value of tStationDlFrameLen can be 125ms, the value of δ can be 125ms, and the typical value of tPropagate can be 270ms.

[0309] 5. After receiving the ACK, the terminal 100 may switch the radio frequency hardware from the receive (Rx) state to the transmit (Tx) state. After switching to the transmit (Tx) state, the terminal 100 may send the (i+1)th SLC PDU.

[0310] If the terminal 100 does not receive the ACK sent by the Beidou network device 200 after the ACK receiving window ends, the terminal 100 can resend the i-th SLC PDU to the Beidou network device 200. After receiving the i-th SLC PDU retransmitted by the terminal 100, the Beidou network device 200 can return an ACK to the terminal 100.

[0311] The following describes the SLC layer's stop-and-wait confirmation mode processing sequence when data is outbound in the Beidou communication system 10 provided in an embodiment of the present application.

[0312] Figure 14 A processing sequence diagram of a stop-and-wait confirmation mode of the SLC layer when data is outbound provided in an embodiment of the present application is shown.

[0313] like Figure 14 As shown, the Beidou communication system 10 may have a stop-and-wait confirmation mode interaction process when data is sent out as follows:

[0314] 1. The Beidou network device 200 may encapsulate the total number of frames field and the frame sequence number field in the frame header information of the i-th SLC PDU according to the protocol rules of the stop-and-wait mode in Table 2 above.

[0315] 2. After sending the i-th SLC PDU to the terminal 100, the Beidou network device 200 may wait to receive an ACK returned by the terminal 100.

[0316] 3. After receiving the i-th SLC PDU sent by terminal 100, terminal 100 can determine that terminal 100 requests an ACK based on the AM enable field, total number of frames field, and frame sequence number field in the frame header information of the i-th SLC PDU, and respond with an ACK using the stop-and-wait confirmation mode. Therefore, terminal 100 can return an ACK to Beidou network device 200 after the signal processing schedule time. The bitmap portion of the ACK is only 1 bit long. This 1-bit bitmap in the ACK can be used to indicate that terminal 100 has received the i-th SLC PDU.

[0317] 4. The Beidou network device 200 can determine the start time (tStationStartRcvAck) and the end time (tStationEndRcvAck) of the ACK reception window based on the time length of the outbound physical frame (tStationDlFrameLen), the air interface propagation delay (tPropagate), the signal processing and scheduling time of the terminal 100 (tUeProcess), and the switching duration from the receiving state to the transmitting state of the terminal 100 (tRx2TxSwitch).

[0318] Among them, in the stop-and-wait acknowledgment mode, it must be ensured that the Beidou network device 200 has opened the ACK reception window before the ACK arrives at the Beidou network 200. Therefore, assuming that the starting point of the i-th SLC PDU sent by the Beidou network device 200 is the t1 moment, the Beidou network device 200 can determine the start time (tStationStartRcvAck) of the ACK reception window through the following formula (3):

[0319] t1 + tStationDlFrameLen < tStationStartRcvAck < t1 + tUeUlFrameLeb + tPropagate * 2 + tUeProcess + tRx2TxSwitch + tStationDlFrameLen Formula (3)

[0320] Among them, in Formula (3), tUeProcess can take the minimum value (t_MinUeProc). The value of tStationDlFrameLen can be 125 ms. Measured from experimental data, the typical value of tPropagate can be 270 ms.

[0321] The Beidou network device 200 can determine the end time (tStationEndRcvAck) of the ACK reception window through the following formula (4):

[0322] tStationEndRcvAck = t1 + tStationDlFrameLen + 2 * tPropagate + tUeUlFrameLen + tUeProcess + tRx2TxSwitch Formula (4)

[0323] Among them, in Formula (4), the value of tUeProcess can take the maximum value (t_MaxUeProc). Measured from experimental data, the value of tStationDlFrameLen can be 125 ms.

[0324] 5. After receiving the ACK, the BeiDou network device 200 may transmit the (i+1)th SLC PDU in the transmission time slot of the next physical frame. If the BeiDou network device 200 does not receive the ACK sent by the terminal 100 after the ACK receiving window ends, the BeiDou network device 200 may terminate the transmission of subsequent SLC PDUs.

[0325] Optionally, when the Beidou network device 200 does not receive an ACK sent by the terminal 100 after the ACK receiving window ends, the Beidou network device 200 may resend the i-th SLC PDU to the terminal 100 in the transmission time slot of the next physical frame. After receiving the i-th SLC PDU retransmitted by the Beidou network device 200, the terminal 100 may return an ACK to the Beidou network device 200.

[0326] The following describes the parallel confirmation mode processing sequence of the SLC layer when data is incoming in the Beidou communication system 10 provided in an embodiment of the present application.

[0327] Figure 15 A processing sequence diagram of a parallel confirmation mode of the SLC layer when data is inbound provided in an embodiment of the present application is shown.

[0328] like Figure 15 As shown, the parallel confirmation mode interaction process of the Beidou communication system 10 when data is inbound can be as follows:

[0329] 1. Terminal 100 may encapsulate the total number of frames field and the frame sequence number field in the frame header information of N (e.g., N is 4) SLC PDUs in an SLC SDU according to the protocol rules of the stop-and-wait confirmation mode in Table 2. Terminal 100 may continuously send the N SLC PDUs in an SLC SDU to Beidou network device 200.

[0330] 2. After terminal 100 sends N SLC PDUs in an SLC SDU to Beidou network device 200, terminal 100 can switch the RF hardware from the transmit (Tx) state to the receive (Rx) state. After switching to the receive (Rx) state, terminal 100 can wait to receive an ACK returned by Beidou network device 200 within the ACK receive window.

[0331] 3. After receiving N SLC PDUs in an SLC SDU sent by terminal 100, Beidou network device 200 can determine that terminal 100 requests an ACK based on the AM enable field, total number of frames field, and frame sequence number field in the frame header information of the received SLC PDU, and respond with an ACK using parallel acknowledgment mode. Therefore, Beidou network device 200 can return an ACK to terminal 100 after the signal processing schedule time. The bitmap portion of the ACK is N bits long and is used to indicate the frame sequence number of the SLC PDU received by Beidou network device 200. The xth bit of the ACK bitmap can be used to indicate whether Beidou network device 200 has received the xth SLC PDU in the SLC SDU, where x ≤ N.

[0332] Optionally, the data length of the Bitmap part of the ACK can be a fixed value, which is greater than or equal to N. The first N bits of the Bitmap part of the ACK can be used to represent the frame sequence number of the SLC PDU received by the Beidou network device 200.

[0333] Among them, the Beidou network device 200 can determine the remaining time length (tStationRevWindow) of the SLC PDU receiving window on the Beidou network device 200 based on the receiving time (tStaRevRctSP) of the most recent SLC PDU received, the frame sequence number (nRevFrameSN) of the most recent SLC PDU received, the total number of SLC PDU frames in the current SLC SDU session (nUeTotalFrameNum), the frame interval (tUeTxInterval) of the physical frame sent by the terminal 100, and the time length (tUeUlFrameLen) of the physical frame sent by the terminal 100.

[0334] The BeiDou network device 200 can determine the remaining time length (tStationRevWindow) of the SLC PDU receiving window by using the following formula (5):

[0335] tStationRevWindow=tStaRevRctSP+(nUeTotalFrameNum-nRevFrameSN-1)*(tUeTxInterval+tUeUlFrameLen)

[0336] Formula (5)

[0337] In the above formula (5), the value of tUeTxInterval is preset in the Beidou network device 200. The above nRevFrameSN={0, 1, ..., nUeTotalFrameNum-1}.

[0338] The Beidou network device 200 may determine the time point (tStationSendAck) for sending an ACK based on the remaining time length (tStationRevWindow) of the SLC PDU receiving window and the signal processing scheduling delay (tStationProcess) of the Beidou network device 200 .

[0339] The Beidou network device 200 can determine the time point of returning the ACK by the following formula (6):

[0340] tStationSendAck=tStationRevWindow+tStationProcess+δ formula (6)

[0341] In the above formula (6), δ is the transmission time alignment deviation of the outbound physical frame on the Beidou network device 200.

[0342] 4. Terminal 100 can determine the starting time (tUeStartRcvAck) when terminal 100 receives ACK based on the time when terminal 100 sends the last SLC PDU in the SLC SDU (tUeTxEnd), the switching time from sending to receiving of terminal 100 (tTx2RxSwitch), the air interface propagation delay (tPropagate), and the station signal processing scheduling time (tStationProcess).

[0343] The terminal 100 can determine the start time of receiving ACK (tUeStartRcvAck) by the following formula (7):

[0344] tUeTxEnd+tRx2TxSwitch<tUeStartRcvAck<tUeTxEnd+2*tPropagate+tStationProcess formula (7)

[0345] In formula (7), tStationProcess can take the minimum value (t_MinStatProc), for example, 1 second.

[0346] The terminal 100 can determine the end time (tUeEndRcvAck) at which the terminal 100 receives ACK based on the time length (tUeUlFrameLen) of the physical frame sent by the terminal 100, the air interface propagation delay (tPropagate) between the terminal 100 and the Beidou network device 200, the signal processing scheduling time (tStationProcess), the time length (tStationDlFrameLen) of the physical frame sent by the Beidou network device 200, and the sending time alignment deviation (δ) of the physical frame on the Beidou network device 200.

[0347] The terminal 100 can determine the end time of returning ACK (tUeEndRcvAck) by the following formula (8):

[0348] tUeEndRcvAck=tUeTxEnd+tUeUlFrameLen+2*tPropagate+tStationProcess+tStationDlFrameLen+δ formula (8)

[0349] In the above formula (8), tStationProcess can take the maximum value (t_MaxStatProc). For example, the value of tStationDlFrameLen for 1 second can be 125ms. In formula (8), the value of δ can be 125ms.

[0350] 5. After receiving the ACK returned by the Beidou network device 200, the terminal 100 can determine the frame sequence number of the SLC PDU that the Beidou network device 200 has not received based on the bitmap portion of the ACK. If the Beidou network device 200 has received all N SLC PDUs in the current SLC SDU, the terminal 100 can switch the RF hardware from the receive (Rx) state to the transmit (Tx) state and send the N SLC PDUs in the next SLC SDU.

[0351] If the Beidou network device 200 has not received the i-th SLC PDU in the current SLC SDU, the terminal 100 can switch the RF hardware from the transmit (Rx) state to the receive (Tx) state and resend the i-th SLC PDU. After the Beidou network device 200 returns an ACK indicating that the N SLC PDUs in the current SLC SDU have been received, the terminal 100 can send the N SLC PDUs in the next SLC SDU.

[0352] The following describes the parallel confirmation mode processing sequence of the SLC layer when data is outbound in the Beidou communication system 10 provided in an embodiment of the present application.

[0353] Figure 16A processing sequence diagram of a parallel confirmation mode of the SLC layer when data is outbound provided in an embodiment of the present application is shown.

[0354] like Figure 16 As shown, the parallel confirmation mode interaction process of the Beidou communication system 10 when data is outbound can be as follows:

[0355] 1. The Beidou network device 200 may encapsulate the total number of frames field and the frame sequence number field in the frame header information of N (e.g., N is 4) SLC PDUs in an SLC SDU according to the protocol rules of the stop-and-wait confirmation mode in Table 2. The terminal 100 may send the N SLC PDUs in an SLC SDU to the terminal 100 at consecutive intervals.

[0356] 2. After the Beidou network device 200 sends N SLC PDUs in an SLC SDU to the terminal 100, the Beidou network device 200 may wait for an ACK returned by the terminal 100 within the ACK receiving window.

[0357] 3. After receiving N SLC PDUs in an SLC SDU sent by Beidou network device 200, terminal 100 can determine that Beidou network device 200 requests an ACK based on the AM enable field, total number of frames field, and frame sequence number field in the frame header information of the received SLC PDU, and then respond with an ACK using the parallel acknowledgment mode. Therefore, after the SLC PDU receive window expires, terminal 100 generates an ACK based on the reception results of the N SLC PDUs and returns the ACK to Beidou network device 200. Since the Beidou short message service communication system does not support data retransmission, the ACK sent by terminal 100 does not need to indicate the frame sequence numbers of incomplete SLC PDUs. It only needs to inform Beidou network device 200 whether all N SLC PDUs have been received or not. Therefore, the bitmap portion of the ACK can be 1 bit in length, which is used to indicate whether terminal 100 has received all N SLC PDUs of the current SLC SDU.

[0358] Optionally, in a later evolution version of the BeiDou short message service communication system, the BeiDou network device 200 may also support data retransmission, and the ACK sent by the terminal 100 may also notify the BeiDou network device 200 of the frame sequence numbers that were not received. Therefore, the length of the bitmap portion of the ACK may be N bits, and the N bits are used to indicate whether the terminal 100 has not received the frame sequence numbers of the N SLC PDUs in the current SLC SDU.

[0359] Among them, the terminal 100 can start the SLC SDU session after receiving the first SLC SDU in the SLC SDU. The terminal 100 can determine the remaining time length (tUeRevWindow) of the SLC PDU receiving window on the terminal 100 based on the frame sequence number (nStationRevFrameSN) of the most recently received SLC PDU, the time when the most recently received SLC PDU was received (tUeRevRctSP), the total number of SLC PDU frames in the SLC SDU (nStationTotalFrameNum), the interval (tStationTxInterval) at which the Beidou network device 200 sends the SLC PDU, and the time length (tStationDlFrameLen) of the physical frame sent by the Beidou network device 200.

[0360] The terminal 100 can determine the remaining time length (tUeRevWindow) of the SLC PDU receiving window by using the following formula (9):

[0361] tUeRevWindow=tUeRevRctSP+(nStationTotalFrameNum-nStationRevFrameSN-1)*(tStationTxInterval+tStationDlFrameLen)

[0362] Formula (9)

[0363] In the above formula (9), the value of tStatiomTxInterval is preset on the terminal 100. In the above nStationRevFrameSN={0, 1, ..., nStationTotalFrameNum-1}, the value of δ may be 125ms.

[0364] 4. After the SLC PDU reception window ends, the terminal 100 generates an ACK based on the reception results of the N SLC PDUs and returns the ACK to the Beidou network device 200. The terminal 100 can determine the time point (tUeSendAck) at which the terminal 100 sends the ACK based on the air interface propagation delay (tPropagate), the terminal 100's signal processing scheduling delay (tUeProcess), the switching time from the terminal 100's receiving state to the transmitting state (tRx2TxSwitch), and the reception time of the most recent SLC PDU received by the terminal 100 (tUeRevRctSP).

[0365] The terminal 100 may determine the time point (tUeSendAck) at which the terminal 100 sends an ACK by using the following formula (10):

[0366] tUeSendAck=tUeRevWindow+tUeProcess+tRx2TxSwitch formula (10)

[0367] 5. The Beidou network device 200 can determine the start time (tStationStartRcvAck) of the ACK receive window (tStationRevAckWindow) and the end time (tStationEndRcvAck) of the ACK receive window based on the time (tStationTxEnd) when the Beidou network device 200 sends the last SLC PDU in the SLC SDU, the air interface propagation delay (tPropagate), the switching time from the receiving state to the sending state of the terminal 100 (tRx2TxSwitch), and the signal processing scheduling delay (tUeProcess) of the terminal 100.

[0368] The BeiDou network device 200 can determine the start time (tStationStartRcvAck) of the ACK receiving window (tStationRevAckWindow) by the following formula (11):

[0369] tStationTxEnd<tStationStartRcvAck<tStationTxEnd+tRx2TxSwitch+2*tPropagate+tUeProcess formula (11)

[0370] In the above formula (11), tUeProcess takes the minimum value t_MinUeProc.

[0371] The BeiDou network device 200 can determine the end time (tStationEndRcvAck) of the ACK receiving window (tStationRevAckWindow) by the following formula (12):

[0372] tStationEndRcvAck=tStationTxEnd+tUeProcess+tRx2TxSwitch+2*tPropagate+tUeUlFrameLen formula (12)

[0373] In the above formula (12), tUeProcess can take the maximum value t_MaxUeProc.

[0374] 6. After receiving the ACK returned by the terminal 100, the Beidou network device 200 can determine whether the terminal 100 has received all N SLC PDUs in the SLC SDU based on the 1-bit bitmap portion of the ACK. If the terminal 100 has received all N SLC PDUs in the current SLC SDU, the Beidou network device 200 can send multiple SLC PDUs in the next SLC SDU.

[0375] If the terminal 100 has not received all N SLC PDUs in the current SLC SDU, the Beidou network device 200 can end the transmission of subsequent SLC SDUs.

[0376] Figure 17 A flow chart of a multi-frame fusion transmission method in a Beidou communication system provided in an embodiment of the present application is shown.

[0377] like Figure 17 As shown, the multi-frame fusion transmission method in the Beidou communication system includes the following steps:

[0378] S1701. Terminal 100 sends a first SLC PDU to a Beidou network device.

[0379] The frame header information of the first SLC PDU includes a first frame total field and a first frame sequence number field, and the first frame total field and the first frame sequence number field are used to combine and indicate the confirmation mode adopted by the terminal requesting the Beidou network device.

[0380] For details about the combination of the first frame sequence number field and the first frame total number field to indicate the confirmation mode, please refer to the aforementioned embodiment and will not be repeated here.

[0381] S1702: When the confirmation mode indicated by the first total number of frames field and the first frame sequence number in the first SLC PDU is a parallel confirmation mode, the Beidou network device 200 continues to receive the SLC PDU in the first SLC SDU sent by the terminal 100.

[0382] S1703: When the number M of SLC PDUs received by the Beidou network device 200 in the first SLC SDU is less than the total number N of SLC PDUs in the first SLC SDU, generate a first ACK;

[0383] S1704 . The Beidou network device 200 sends a first ACK to the terminal 100 .

[0384] The first ACK is used to indicate the frame sequence number of the SLC PDU that the Beidou network device 200 has not received in the N SLC PDUs of the first SLC SDU, and the N SLC PDUs of the first SLC SDU include the first SLC PDU. In parallel confirmation mode, the first total number of frames field is used to indicate the total number N of SLC PDUs in the first SLC SDU, and the first frame sequence number field is used to indicate the frame sequence number of the first SLC PDU in the first SLC SDU.

[0385] S1705 . After receiving the first ACK, the terminal 100 retransmits the SLC PDU in the first SLC SDU that the Beidou network device 200 has not received.

[0386] For a detailed description of the BeiDou network device 200 feeding back ACK in the parallel confirmation mode, please refer to the aforementioned Figure 15 The embodiments shown will not be described in detail here.

[0387] Some possible implementations performed by the terminal 100 are described below.

[0388] In one possible implementation, when the confirmation mode indicated by the combination of the first frame total field and the first frame sequence number field is a parallel confirmation mode, when the terminal 100 receives the second ACK sent by the Beidou network device 200, the terminal 100 sends one or more SLC PDUs in the second SLC SDU to the Beidou network device 200, and the second ACK is used to indicate that the Beidou network device 200 has received N SLC PDUs in the first SLC SDU.

[0389] In one possible implementation, when the confirmation mode indicated by the combination of the first frame total field and the first frame sequence number field is a parallel confirmation mode, and the terminal 100 does not receive the ACK sent by the Beidou network device 200 within the ACK reception time window after sending the N SLC PDUs in the first SLC SDU, the terminal 100 retransmits the N SLC PDUs in the first SLC SDU to the Beidou network device 200.

[0390] In one possible implementation, when the confirmation mode indicated by the combination of the first frame total field and the first frame sequence number field is a stop-and-wait confirmation mode, the terminal 100 receives a third ACK sent by the Beidou network device 200, and the third ACK is used to indicate that the Beidou network device 200 has received the first SLC PDU; the terminal 100 sends a second SLC PDU to the Beidou network device 200.

[0391] In one possible implementation, the method also includes: when the confirmation mode indicated by the combination of the first frame total field and the first frame sequence number field is a stop-and-wait confirmation mode, and the terminal 100 does not receive the ACK sent by the Beidou network device 200 within the ACK reception time window after sending the first SLC PDU, the terminal 100 retransmits the first SLC PDU to the Beidou network device 200.

[0392] In one possible implementation, in the stop-and-wait confirmation mode, the value of the second frame sequence number field in the second SLC PDU is different from the value of the first frame sequence number field, and the value of the second frame total number field is the same as the value of the first frame total number field; or, the value of the second frame sequence number field is the same as the value of the first frame sequence number field, and the value of the second frame total number field is different from the value of the first frame total number field; or, the value of the second frame sequence number field is different from the value of the first frame sequence number field, and the value of the second frame total number field is different from the value of the first frame total number field.

[0393] In a possible implementation, in the parallel confirmation mode, the value of the first frame total number field is greater than or equal to the value of the first frame sequence number field.

[0394] In a possible implementation, in the stop-and-wait mode confirmation, the value of the first frame total number field is less than the value of the first frame sequence number field.

[0395] In one possible implementation, in the parallel confirmation mode, the terminal 100 determines the starting time of the ACK receiving time window based on the time when the terminal 100 sends the last SLC PDU in the first SLC SDU, the switching time length of the terminal 100 from the sending state to the receiving state, the air interface propagation delay and the signal processing scheduling delay of the Beidou network device 200; the terminal 100 starts to receive the ACK sent by the Beidou network device 200 at the starting time of the ACK receiving time window.

[0396] The formula for the terminal 100 to determine the starting time in the ACK reception time window is:

[0397] tUeTxEnd+tTx2RxSwitch<tUeStartRcvAck<tUeTxEnd+2*tPropagate+tStationProcess

[0398] Among them, tUeStartRcvAck is the starting time of the ACK receiving time window, tUeTxEnd is the time when the terminal 100 sends the last SLC PDU in the first SLC SDU, tTx2PxSwitch is the switching time length of the terminal 100 from the sending state to the receiving state, tPropagate is the air interface propagation delay, and tStationProcess is the signal processing scheduling delay on the Beidou network device 200.

[0399] In one possible implementation, in the parallel confirmation mode, the terminal 100 determines the end time of the ACK reception time window based on the time length of the physical frame sent by the terminal 100, the air interface propagation delay, the signal processing scheduling delay of the Beidou network device 200, the time length of the physical frame sent by the Beidou network device 200, and the time alignment deviation of the physical frame sent by the Beidou network device 200; the terminal 100 stops receiving the ACK sent by the Beidou network device 200 at the end time of the ACK reception time window.

[0400] The formula for the terminal 100 to determine the end time within the ACK reception time window is:

[0401] tUeEndRcvAck=tUeTxEnd+tUeUlFrameLen+2*tPropagate+tStationProcess+tStationDlFrameLen+δ

[0402] Among them, tUeEndRcbAck is the end time of the ACK receive time window, tUeUlFrameLen is the time length of the physical frame sent by the terminal 100, tPropagate is the air interface propagation delay, tStationProcess is the signal processing scheduling delay of the Beidou network device 200, tStationDlFrameLen is the time length of the physical frame sent by the Beidou network device 200, and δ is the time alignment deviation of the Beidou network device 200 sending the physical frame.

[0403] In one possible implementation, in the stop-and-wait mode, the terminal 100 determines the starting time of the ACK reception time window based on the starting time of the terminal 100 sending the first SLC PDU, the time length of the physical frame sent by the terminal 100, the switching time length of the terminal 100 from the sending state to the receiving state, the air interface propagation delay and the signal processing scheduling delay of the Beidou network device 200; the terminal 100 starts to receive the ACK sent by the Beidou network device 200 at the starting time of the ACK reception time window.

[0404] The formula for the terminal 100 to determine the start time of the ACK reception time window is:

[0405] t0+tUeUlFrameLen+tTx2RsSwitch <tUeStartRcvAck<t0+tUeUlFrameLen+2*tPropagate+tStationProcess

[0406] Among them, tUeEndRcvAck is the end time of the ACK receiving time window, t0 is the starting time when the terminal 100 sends the first SLC PDU, tUeUlFrameLen is the time length of the physical frame sent by the terminal 100, tTx2RxSwitch is the switching time length of the terminal 100 from the sending state to the receiving state, tPropagate is the air interface propagation delay, and tStationProcess is the signal processing scheduling delay of the Beidou network device 200.

[0407] In one possible implementation, in the stop-and-wait mode, the terminal 100 determines the end time of the ACK reception time window based on the time length of the physical frame sent by the terminal 100, the air interface propagation delay, the signal processing scheduling delay of the Beidou network device 200, the time length of the physical frame sent by the Beidou network device 200, and the time alignment deviation of the physical frame sent by the Beidou network device 200; the terminal 100 stops receiving the ACK sent by the Beidou network device 200 at the end time of the ACK reception time window.

[0408] The formula for the terminal 100 to determine the end time of the ACK reception time window is:

[0409] tUeEndRcvAck=t0+UeUlFrameLen+tPropagate*2+tStationProcess+tStationDlFrameLen+δ

[0410] Among them, tUeEndRcvAck is the end time of the ACK reception time window, t0 is the starting time when the terminal 100 sends the first SLC PDU, tUeUlFrameLen is the time length of the physical frame sent by the terminal 100, tStationDlFrameLen is the time length of the physical frame sent by the Beidou network device 200, tPropagate is the air interface propagation delay, tStationProcess is the signal processing scheduling delay of the Beidou network device 200, and δ is the time alignment deviation of the Beidou network device 200 to send the physical frame.

[0411] The following introduces some possible implementations of the Beidou network device 200.

[0412] In one possible implementation, when M is equal to N, the Beidou network device 200 sends a second ACK to the terminal 100, wherein the second ACK is used to indicate that the Beidou network device 200 has received N SLC PDUs in the first SLC SDU; the Beidou network device 200 receives one or more SLC PDUs in the second SLC SDU sent by the terminal 100.

[0413] In one possible implementation, when the confirmation mode indicated by the combination of the first frame total field and the first frame sequence number field is a stop-and-wait confirmation mode, the Beidou network device 200 sends a third ACK to the terminal 100, and the third ACK is used to indicate that the Beidou network device 200 has received the first SLC PDU; the Beidou network device 200 receives the second SLC PDU sent by the terminal 100.

[0414] In one possible implementation, in the stop-and-wait confirmation mode, the value of the second frame sequence number field in the second SLC PDU is different from the value of the first frame sequence number field, and the value of the second frame total number field is the same as the value of the first frame total number field; or, the value of the second frame sequence number field is the same as the value of the first frame sequence number field, and the value of the second frame total number field is different from the value of the first frame total number field; or, the value of the second frame sequence number field is different from the value of the first frame sequence number field, and the value of the second frame total number field is different from the value of the first frame total number field.

[0415] In a possible implementation, in the parallel confirmation mode, the value of the first frame total number field is greater than or equal to the value of the first frame sequence number field.

[0416] In a possible implementation, in the stop-and-wait confirmation mode, the value of the first frame total number field is smaller than the value of the first frame sequence number field.

[0417] In one possible implementation, in parallel confirmation mode, the Beidou network device 200 determines the remaining time length of the SLC PDU receiving window based on the frame sequence number of the first SLC PDU, the total number of SLC PDUs in the first SLC SDU, the reception time of the first SLC PDU, the frame interval of the physical frame sent by the terminal 100, and the time length of the physical frame sent by the terminal 100.

[0418] The Beidou network device 200 determines the remaining time length of the SLC PDU receiving window by the following formula:

[0419] tStationRevWindow=tStaRevRctSP+(nUeTotalFrameNum-nRevFrameSN-1)*(tUeTxInterval+tUeUlFrameLen)

[0420] Wherein, tStationRevWindow is the remaining time length of the SLC PDU receiving window, ttStaRevRctSP is the reception time of the first SLC PDU, nUeTotalFrameNum is the total number of SLC PDUs in the first SLC SDU, nRevFrameSN is the frame sequence number of the first SLC PDU, tUeTxInterval is the frame interval for sending physical frames by terminal 100, and tUeUlFrameLen is the time length of the physical frame sent by terminal 100.

[0421] In a possible implementation, in the parallel confirmation mode, the Beidou network device 200 determines the time point for sending the ACK based on the remaining time length of the SLC PDU receiving window and the signal processing scheduling delay of the Beidou network device 200.

[0422] The Beidou network device 200 determines the time point for sending the ACK using the following formula:

[0423] tStationSendAck=tStationRevWindow+tStationProcess+δ

[0424] Among them, tStationSendAck is the time point when the Beidou network device 200 sends ACK, tStationRevWindow is the remaining time length of the SLC PDU receiving window, tStationProcess is the signal processing scheduling delay on the Beidou network device 200, and δ is the sending time alignment deviation of the outbound physical frame on the Beidou network device 200.

[0425] The embodiments of the present application provide a multi-frame fusion transmission method in a Beidou communication system. This allows a transmitter to negotiate an acknowledgment mode with a receiver using the total number of frames field and the frame sequence number field in the data frame header. This eliminates the need for additional header cell overhead and control signaling overhead when negotiating the acknowledgment mode between the transmitter and receiver.

[0426] The above content elaborates on the method provided by the present application. In order to facilitate better implementation of the above scheme of the embodiment of the present application, the embodiment of the present application also provides corresponding devices or equipment.

[0427] In the embodiment of the present application, the terminal 100 can be divided into functional modules according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated modules can be implemented in the form of hardware or software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical functional division. In actual implementation, there may be other division methods.

[0428] The following will be combined Figures 18 to 21 The communication device according to the embodiment of the present application is described in detail.

[0429] In the case of integrated units, see Figure 18 , Figure 18 1 is a schematic diagram of the structure of the communication device 1800 provided in an embodiment of the present application. The communication device 1800 may be the terminal 100 in the above embodiment. Optionally, the communication device 1800 may be a chip / chip system, for example, a Beidou communication chip. Figure 18 As shown, the communication device 1800 may include a transceiver unit 1810 and a processing unit 1820 .

[0430] In one design, the transceiver unit 1810 may be configured to send a first SLC PDU to the Beidou network device 200. The frame header information of the first SLC PDU includes a first total number of frames field and a first frame sequence number field, where the first total number of frames field and the first frame sequence number field are used in combination to indicate an acknowledgment mode that the terminal requests the Beidou network device to adopt.

[0431] The transceiver unit 1810 is further configured to receive a first ACK returned by the Beidou network device 200 when the acknowledgment mode indicated by the combination of the first total number of frames field and the first frame sequence number field is the parallel acknowledgment mode. The first ACK is configured to indicate the frame sequence number of the SLC PDU in the first SLC SDU that was not received by the Beidou network device. In the parallel acknowledgment mode, the first total number of frames field is configured to indicate the total number N of SLC PDUs in the first SLC SDU, and the first frame sequence number field is configured to indicate the frame sequence number of the first SLC PDU in the first SLC SDU.

[0432] The processing unit 1820 may be configured to determine, based on the first ACK, an SLC PDU in the first SLC SDU that is not received by the Beidou network device 200 .

[0433] The transceiver unit 1810 is further configured to retransmit the SLC PDU in the first SLC SDU that the Beidou network device 200 has not received to the Beidou network device 200 .

[0434] Optionally, the transceiver unit 1810 may also be used to perform the above Figure 17 The terminal 100 in the illustrated method embodiment performs the functional steps related to sending and receiving.

[0435] Optionally, the processing unit 1820 may also be configured to execute the above Figure 17 The method embodiment shown includes the functional steps of protocol parsing and encapsulation and calculation determination performed by the terminal 100.

[0436] It should be understood that the communication device 1800 in this design can execute the method steps executed by the terminal 100 in the aforementioned embodiment. For the sake of brevity, they will not be repeated here.

[0437] In the case of integrated units, see Figure 19 , Figure 19 1 is a schematic diagram of the structure of the communication device 1900 provided in an embodiment of the present application. The communication device 1900 may be the Beidou network device 200 in the above embodiment. Optionally, the communication device 1900 may be a specific network element in the Beidou network device 200, for example, a network element or a combination of multiple network elements in the Beidou ground transceiver station 22, the Beidou central station 23, and the Beidou short message fusion communication platform 24. Figure 19 As shown, the communication device 1900 may include a transceiver unit 1910 and a processing unit 1920 .

[0438] In one design, the transceiver unit 1910 can be used to receive the first SLC PDU sent by the terminal 100, wherein the frame header information of the first SLC PDU includes a first frame total number field and a first frame sequence number field, and the first frame total number field and the first frame sequence number field are used in combination to indicate the confirmation mode that the terminal 100 requests the Beidou network device 200 to adopt.

[0439] The transceiver unit 1910 is further configured to, when the acknowledgment mode indicated by the combination of the first total number of frames field and the first frame sequence number field is the parallel acknowledgment mode, continue to receive the SLC PDU in the first SLC SDU sent by the terminal 100. In the parallel acknowledgment mode, the first total number of frames field is used to indicate the total number N of SLC PDUs in the first SLC SDU, and the first frame sequence number field is used to indicate the frame sequence number of the first SLC PDU in the first SLC SDU.

[0440] The processing unit 1920 may be configured to generate a first ACK based on the frame header information of the M SLC PDUs of the received first SLC SDU.

[0441] The transceiver unit 1910 is further used to send a first ACK to the terminal 100 when M is less than N, where M is a positive integer. The first ACK is used to indicate the frame sequence number of the SLC PDU that the Beidou network device 200 has not received among the N SLC PDUs of the first SLC SDU.

[0442] The transceiver unit 1910 is further configured to receive the SLC PDU that is not received by the Beidou network device in the first SLC SDU retransmitted by the terminal 100 .

[0443] Optionally, the transceiver unit 1910 may also be used to perform the above Figure 11 The Beidou network device 200 in the illustrated method embodiment performs the functional steps related to sending and receiving.

[0444] Optionally, the processing unit 1920 may also be configured to execute the above Figure 11 The method embodiment shown includes the functional steps of protocol parsing and encapsulation and calculation determination performed by the Beidou network device 200.

[0445] It should be understood that the communication device 1900 in this design can execute the method steps executed by the Beidou network device 200 in the aforementioned embodiment. For the sake of brevity, they will not be repeated here.

[0446] The above describes the terminal 100 and BeiDou network device 200 of the embodiment of the present application. It should be understood that any device having the above Figure 18 Any product having the functions of the terminal 100 as described above Figure 19 Any product that implements the functions of the Beidou network device 200 falls within the protection scope of the embodiments of the present application.

[0447] As a possible product form, the terminal 100 described in the embodiment of the present application can be implemented by a general bus architecture.

[0448] See also Figure 20 , Figure 20 1 is a schematic diagram of the structure of the communication device 2000 provided in an embodiment of the present application. The communication device 2000 may be the terminal 100, or a device therein. Figure 20As shown, the communication device 2000 includes a processor 2001 and a transceiver 2002 connected to the internal communication of the processor. The processor 2001 can be a general-purpose processor or a dedicated processor. For example, it can be a baseband processor or a central processing unit for satellite communication. The baseband processor for satellite communication can be used to process satellite communication protocols and satellite communication data, and the central processing unit can be used to control the communication device (such as a baseband chip, a terminal, a terminal chip, etc.), execute computer programs, and process computer program data. The transceiver 2002 can be called a transceiver unit, a transceiver, or a transceiver circuit, etc., and is used to implement transceiver functions. The transceiver 2002 can include a receiver and a transmitter. The receiver can be called a receiver or a receiving circuit, etc., and is used to implement the receiving function; the transmitter can be called a transmitter or a transmitting circuit, etc., and is used to implement the transmitting function. Optionally, the communication device 2000 can also include an antenna 2003 and / or a radio frequency unit (not shown in the figure). The antenna 2003 and / or the radio frequency unit may be located inside the communication device 2000 or may be separated from the communication device 2000 , that is, the antenna 2003 and / or the radio frequency unit may be remotely or distributedly deployed.

[0449] Optionally, the communication device 2000 may include one or more memories 2004, on which instructions may be stored. The instructions may be computer programs. The computer programs may be executed on the communication device 2000 to enable the communication device 2000 to perform the methods described in the above method embodiments. Optionally, the memories 2004 may also store data. The communication device 2000 and the memories 2004 may be provided separately or integrated together.

[0450] The processor 2001 , the transceiver 2002 , and the memory 2004 may be connected via a communication bus.

[0451] In one design, the communication device 2000 may be configured to perform the functions of the terminal 100 in the aforementioned embodiment: the processor 2001 may be configured to perform the aforementioned Figure 17 In the embodiment shown, the terminal 100 performs the protocol parsing and encapsulation and the functional steps determined by the operation and / or other processes used in the technology described herein; the transceiver 2002 can be used to perform the above Figure 17 The terminal 100 in the illustrated embodiment performs functional steps related to transmission and reception and / or other processes for the technology described herein.

[0452] In any of the above designs, processor 2001 may include a transceiver for implementing receiving and transmitting 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 the receiving and transmitting functions may be separate or integrated. The transceiver circuit, interface, or interface circuit may be used for reading and writing code / data, or the transceiver circuit, interface, or interface circuit may be used for transmitting or delivering signals.

[0453] In any of the above designs, the processor 2001 may store instructions, which may be computer programs. The computer programs, when executed on the processor 2001, may cause the communication device 2000 to execute the method steps performed by the terminal 100 in the above method embodiment. The computer programs may be fixed in the processor 2000, in which case the processor 2001 may be implemented by hardware.

[0454] In one implementation, the communication device 2000 may include a circuit that can implement the functions of sending, receiving, or communicating in the aforementioned method embodiments. The processor and transceiver described in this application can be implemented on an integrated circuit (IC), an analog IC, a radio frequency integrated circuit RFIC, a mixed signal IC, an application specific integrated circuit (ASIC), a printed circuit board (PCB), an electronic device, etc. The processor and transceiver can also be manufactured using various IC process technologies, such as complementary metal oxide semiconductor (CMOS), N-type metal oxide semiconductor (nMetal-oxide-semiconductor, NMOS), P-type metal oxide semiconductor (positive channel metal oxide semiconductor, PMOS), bipolar junction transistor (bipolar junction transistor, BJT), bipolar CMOS (BiCMOS), silicon germanium (SiGe), gallium arsenide (GaAs), etc.

[0455] The scope of the communication device described in this application is not limited thereto, and the structure of the communication device may not be limited thereto. Figure 20 The communication device 2000 may be an independent device or may be part of a larger device. For example, the communication device 2000 may be:

[0456] (1) An independent integrated circuit (IC), or chip, or chip system or subsystem;

[0457] (2) a collection of one or more ICs, optionally including a storage component for storing data and computer programs;

[0458] (3) ASIC, such as modem;

[0459] (4) Modules that can be embedded in other devices;

[0460] (5) Receivers, terminals, smart terminals, cellular phones, wireless devices, handheld devices, mobile units, vehicle-mounted devices, network devices, cloud devices, artificial intelligence devices, etc.;

[0461] (6)Others, etc.

[0462] As a possible product form, any network element in the Beidou network device 200 described in the embodiment of the present application (for example, the Beidou ground transceiver station 22, the Beidou central station 23, the Beidou short message fusion communication platform 24) can be implemented by a general bus architecture.

[0463] See also Figure 21 , Figure 21 2 is a schematic diagram of the structure of the communication device 2100 provided in the embodiment of the present application. The communication device 2100 may be a Beidou network device 200, or a device therein. Figure 21 As shown, the communication device 2100 includes a processor 2101 and a transceiver 2102 connected to the internal communication of the processor. The processor 2101 is a general-purpose processor or a dedicated processor. For example, it can be a baseband processor or a central processing unit for satellite communication. The baseband processor for satellite communication can be used to process satellite communication protocols and satellite communication data, and the central processing unit can be used to control the communication device (such as a baseband chip, etc.), execute computer programs, and process computer program data. The transceiver 2102 can be called a transceiver unit, a transceiver, or a transceiver circuit, etc., for implementing transceiver functions. The transceiver 2102 can include a receiver and a transmitter. The receiver can be called a receiver or a receiving circuit, etc., for implementing a receiving function; the transmitter can be called a transmitter or a transmitting circuit, etc., for implementing a transmitting function. Optionally, the communication device 2100 can also include an antenna 2103 and / or a radio frequency unit (not shown). The antenna 2103 and / or the radio frequency unit may be located inside the communication device 2100 or may be separated from the communication device 2100 , that is, the antenna 2103 and / or the radio frequency unit may be remotely or distributedly deployed.

[0464] Optionally, the communication device 2100 may include one or more memories 2104, on which instructions may be stored. The instructions may be computer programs. The computer programs may be executed on the communication device 2100 to enable the communication device 2100 to perform the methods described in the above method embodiments. Optionally, the memories 2104 may also store data. The communication device 2100 and the memories 2104 may be provided separately or integrated together.

[0465] The processor 2101 , the transceiver 2102 , and the memory 2104 may be connected via a communication bus.

[0466] In one design, the communication device 2100 can be used to perform the functions of the Beidou network device 200 in the above embodiment: the processor 2101 can be used to perform the above Figure 17 In the embodiment shown, the Beidou network device 200 performs the protocol parsing and encapsulation and the functional steps determined by the operation and / or other processes used in the technology described herein; the transceiver 2102 can be used to perform the above Figure 17 The Beidou network device 200 in the illustrated embodiment performs functional steps related to sending and receiving and / or other processes for the technology described herein.

[0467] In any of the above designs, processor 2101 may include a transceiver for implementing receiving and transmitting 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 the receiving and transmitting functions may be separate or integrated. The transceiver circuit, interface, or interface circuit may be used for reading and writing code / data, or the transceiver circuit, interface, or interface circuit may be used for transmitting or delivering signals.

[0468] In any of the above designs, the processor 2101 may store instructions, which may be computer programs. The computer programs run on the processor 2101, causing the communication device 2100 to perform the method steps performed by the terminal 100 in the above method embodiment. The computer program may be fixed in the processor 2101, in which case the processor 2101 may be implemented by hardware.

[0469] An embodiment of the present application further provides a computer-readable storage medium, in which a computer program code is stored. When the processor executes the computer program code, the electronic device executes the method in any of the aforementioned embodiments.

[0470] An embodiment of the present application further provides a computer program product, which, when executed on a computer, enables the computer to execute the method in any of the aforementioned embodiments.

[0471] An embodiment of the present application also provides a communication device, which can exist in the form of a chip product. The structure of 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 executes the method in any of the aforementioned embodiments.

[0472] An embodiment of the present application further provides a Beidou communication system, including a terminal 100 and a Beidou network device 200. The terminal 100 and the Beidou network device 200 can execute the method in any of the aforementioned embodiments.

[0473] This application describes the short message communication function of the Beidou communication system. It is understood that other satellite systems may also support short message communication functions. Therefore, the method described in this application is not limited to the Beidou communication system. If other satellite systems also support short message communication functions, the method described in this application is also applicable to communications in other satellite systems.

[0474] The steps of the method or algorithm described in conjunction with the disclosure of this application can be implemented in hardware or by executing software instructions by a processor. The software instructions can be composed of corresponding software modules, which can be stored in random access memory (RAM), flash memory, erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, mobile hard disks, read-only compact disks (CD-ROMs), or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a core network interface device. Of course, the processor and the storage medium can also exist in the core network interface device as discrete components.

[0475] Those skilled in the art will appreciate that, in one or more of the examples above, the functions described herein can be implemented using hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer-readable storage media and communication media, wherein communication media include any medium that facilitates the transmission of a computer program from one place to another. The storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0476] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A multi-frame fusion transmission method in a satellite communication system, characterized in that: include: The terminal sends a first satellite link control layer protocol data unit (SLC PDU) to the satellite network device, wherein the frame header information of the first SLC PDU includes a first total number of frames field and a first frame sequence number field, and the first total number of frames field and the first frame sequence number field are used to combine and indicate an acknowledgment mode that the terminal requests the satellite network device to adopt; When the confirmation mode indicated by the combination of the first frame total number field and the first frame sequence number field is a parallel confirmation mode, when the terminal receives a first confirmation character ACK sent by the satellite network device, the terminal retransmits the SLC PDU that the satellite network device has not received in the first SLC SDU to the satellite network device; The first ACK is used to indicate the frame sequence number of the SLC PDU not received by the satellite network device in the N SLC PDUs of the first satellite link control layer service data unit SLC SDU, the N SLC PDUs of the first SLC SDU include the first SLC PDU, the first total number of frames field is used to indicate the total number N of SLC PDUs in the first SLC SDU, and the first frame sequence number field is used to indicate the frame sequence number of the first SLC PDU in the first SLC SDU.

2. The method according to claim 1, characterized in that The method further comprises: When the confirmation mode indicated by the combination of the first frame total number field and the first frame sequence number field is a parallel confirmation mode, when the terminal receives the second ACK sent by the satellite network device, the terminal sends one or more SLC PDUs in the second SLC SDU to the satellite network device, and the second ACK is used to indicate that the satellite network device has received N SLC PDUs in the first SLC SDU.

3. The method according to claim 1, characterized in that The method further comprises: When the confirmation mode indicated by the combination of the first frame total field and the first frame sequence number field is a parallel confirmation mode, and the terminal does not receive the ACK sent by the satellite network device within the ACK reception time window after sending N SLC PDUs in the first SLC SDU, the terminal retransmits the N SLC PDUs in the first SLC SDU to the satellite network device.

4. The method according to claim 1, wherein The method further comprises: When the confirmation mode indicated by the combination of the first total number of frames field and the first frame sequence number field is a stop-and-wait confirmation mode, the terminal receives a third ACK sent by the satellite network device, where the third ACK is used to indicate that the satellite network device has received the first SLC PDU; The terminal sends a second SLC PDU to the satellite network device.

5. The method according to claim 1, characterized in that The method further comprises: When the confirmation mode indicated by the combination of the first frame total number field and the first frame sequence number field is a stop-and-wait confirmation mode, and the terminal does not receive the ACK sent by the satellite network device within the ACK reception time window after sending the first SLC PDU, the terminal retransmits the first SLC PDU to the satellite network device.

6. The method according to claim 4, characterized in that A value of a second frame sequence number field in the second SLC PDU is different from a value of the first frame sequence number field, and a value of a second total number of frames field in the second SLC PDU is the same as a value of the first total number of frames field; or, A value of the second frame sequence number field is the same as a value of the first frame sequence number field, and a value of the second total number of frames field is different from a value of the first total number of frames field; or, The value of the second frame sequence number field is different from the value of the first frame sequence number field, and the value of the second total number of frames field is different from the value of the first total number of frames field.

7. The method according to any one of claims 1 to 3, characterized in that The value of the first frame total number field is greater than or equal to the value of the first frame sequence number field.

8. The method according to any one of claims 4 to 6, characterized in that The value of the first frame total number field is smaller than the value of the first frame sequence number field.

9. The method according to any one of claims 1 to 3, characterized in that The method further comprises: The terminal determines, based on the time when the terminal sends the last SLC PDU in the first SLC SDU, the switching time length of the terminal from the sending state to the receiving state, the air interface propagation delay, and the signal processing scheduling delay of the satellite network device, the starting time of the ACK receiving time window; The terminal starts to receive the ACK sent by the satellite network device at the start time of the ACK reception time window.

10. The method according to claim 9, characterized in that The formula for the terminal to determine the starting time within the ACK reception time window is: tUeTxEnd+tTx2RxSwitch<tUeStartRcvAck<tUeTxEnd+2*tPropagate+tStationProcess Among them, tUeStartRcvAck is the starting time of the ACK receiving time window, tUeTxEnd is the time when the terminal sends the last SLC PDU in the first SLC SDU, tTx2RxSwitch is the switching time length of the terminal from the sending state to the receiving state, tPropagate is the air interface propagation delay, and tStationProcess is the signal processing scheduling delay on the satellite network device.

11. The method according to any one of claims 1 to 3, characterized in that The method further comprises: The terminal determines, based on a time length of a physical frame sent by the terminal, an air interface propagation delay, a signal processing scheduling delay of the satellite network device, a time length of a physical frame sent by the satellite network device, and a time alignment deviation of the physical frame sent by the satellite network device, an end time of the ACK reception time window; The terminal stops receiving the ACK sent by the satellite network device at the end time of the ACK reception time window.

12. The method according to claim 11, characterized in that The formula for the terminal to determine the end time of the ACK reception time window is: tUeEndRcvAck=tUeTxEnd+tUeUlFrameLen+2*tPropagate+tStationProcess+tStationDlFrameLen+δ Among them, tUeEndRcuAck is the end time of the ACK reception time window, tUeTxEnd is the time when the terminal sends the last SLC PDU in the first SLC SDU, tUeUlFrameLen is the time length of the physical frame sent by the terminal, tPropagate is the air interface propagation delay, tStationProcess is the signal processing scheduling delay of the satellite network device, tStationDlFrameLen is the time length of the physical frame sent by the satellite network device, and δ is the time alignment deviation of the satellite network device sending the physical frame.

13. The method according to any one of claims 4 to 6, characterized in that The method further comprises: The terminal determines, based on the start time of sending the first SLC PDU by the terminal, the duration of the physical frame sent by the terminal, the switching time from the sending state to the receiving state of the terminal, the air interface propagation delay, and the signal processing scheduling delay of the satellite network device, the start time of the ACK receiving time window; The terminal starts to receive the ACK sent by the satellite network device at the start time of the ACK reception time window.

14. The method according to claim 13, wherein: The formula for the terminal to determine the starting time of the ACK reception time window is: t0+tUeUlFrameLen+tTx2RxSwitch <tUeStartRcvAck<t0+tUeUlFrameLen+2*tPropagate+tStationProcess Among them, tUeStartRcvAck is the starting time of the ACK receiving time window, t0 is the starting time of the terminal sending the first SLC PDU, tUeUlFrameLen is the time length of the physical frame sent by the terminal, tTx2RxSwitch is the switching time length of the terminal from the sending state to the receiving state, tPropagate is the air interface propagation delay, and tStationProcess is the signal processing scheduling delay of the satellite network equipment.

15. The method according to any one of claims 4 to 6, characterized in that The method further comprises: The terminal determines, based on a time length of a physical frame sent by the terminal, an air interface propagation delay, a signal processing scheduling delay of the satellite network device, a time length of a physical frame sent by the satellite network device, and a time alignment deviation of the physical frame sent by the satellite network device, an end time of the ACK reception time window; The terminal stops receiving the ACK sent by the satellite network device at the end time of the ACK reception time window.

16. The method according to claim 15, characterized in that The formula used by the terminal to determine the end time of the ACK reception time window is: tUeEndRcvAck=t0+tUeUlFrameLen+tPropagate*2+tStationProcess+tStationDlFrameLen+δ Among them, tUeEndRcvAck is the end time of the ACK reception time window, t0 is the starting time when the terminal sends the first SLC PDU, tUeUlFrameLen is the time length of the physical frame sent by the terminal, tStationDlFrameLen is the time length of the physical frame sent by the satellite network device, tPropagate is the air interface propagation delay, tStationProcess is the signal processing scheduling delay of the satellite network device, and δ is the time alignment deviation of the satellite network device sending the physical frame.

17. A multi-frame fusion transmission method in a satellite communication system, characterized in that: include: The satellite network device receives a first SLC PDU sent by the terminal, wherein the frame header information of the first SLC PDU includes a first total number of frames field and a first frame sequence number field, and the first total number of frames field and the first frame sequence number field are used to combine and indicate an acknowledgment mode that the terminal requests the satellite network device to adopt; When the confirmation mode indicated by the combination of the first total number of frames field and the first frame sequence number field is a parallel confirmation mode, the satellite network device continues to receive the SLC PDU in the first SLC SDU sent by the terminal; wherein the first total number of frames field is used to indicate the total number N of SLC PDUs in the first SLC SDU, and the first frame sequence number field is used to indicate the frame sequence number of the first SLC PDU in the first SLC SDU; When the number M of SLC PDUs received by the satellite network device in the first SLC SDU is less than N, the satellite network device sends a first ACK to the terminal, where M is a positive integer, and the first ACK is used to indicate the frame sequence number of the SLC PDU that the satellite network device has not received among the N SLC PDUs in the first SLC SDU; The satellite network device receives the SLC PDU that the satellite network device has not received in the first SLC SDU retransmitted by the terminal.

18. The method according to claim 17, characterized in that The method comprises: When the M is equal to the N, the satellite network device sends a second ACK to the terminal, wherein the second ACK is used to indicate that the satellite network device has received N SLC PDUs in the first SLC SDU; The satellite network device receives one or more SLC PDUs in a second SLC SDU sent by the terminal.

19. The method according to claim 17, wherein The method further comprises: When the confirmation mode indicated by the combination of the first total number of frames field and the first frame sequence number field is a stop-and-wait confirmation mode, the satellite network device sends a third ACK to the terminal, where the third ACK is used to indicate that the satellite network device has received the first SLC PDU; The satellite network device receives a second SLC PDU sent by the terminal.

20. The method according to claim 19, characterized in that A value of a second frame sequence number field in the second SLC PDU is different from a value of the first frame sequence number field, and a value of a second total number of frames field in the second SLC PDU is the same as a value of the first total number of frames field; or, A value of the second frame sequence number field is the same as a value of the first frame sequence number field, and a value of the second total number of frames field is different from a value of the first total number of frames field; or, The value of the second frame sequence number field is different from the value of the first frame sequence number field, and the value of the second total number of frames field is different from the value of the first total number of frames field.

21. The method according to claim 17 or 18, characterized in that The value of the first frame total number field is greater than or equal to the value of the first frame sequence number field.

22. The method according to claim 19 or 20, characterized in that The value of the first frame total number field is smaller than the value of the first frame sequence number field.

23. The method according to claim 17 or 18, characterized in that The method further comprises: The satellite network device determines the remaining time length of the SLC PDU receiving window based on the frame sequence number of the first SLC PDU, the total number of SLC PDUs in the first SLC SDU, the reception time of the first SLC PDU, the frame interval of the physical frame sent by the terminal, and the time length of the physical frame sent by the terminal.

24. The method according to claim 23, wherein The satellite network device determines the remaining time length of the SLC PDU receiving window by the following formula: tStationRevWindow=tStaRevRctSP+(nUeTotalFrameNum-nRevFrameSN-1)*(tUeTInterval+tUeUlFrameLen) Among them, tStationRevWindow is the remaining time length of the SLC PDU receiving window, ttStaRevRctSP is the receiving time of the first SLC PDU, nUeTotalFrameNum is the total number of SLC PDUs in the first SLC SDU, nRevFrameSN is the frame sequence number of the first SLC PDU, tUeTxInteral is the frame interval for the terminal to send physical frames, and tUeUlFrameLen is the time length of the physical frame sent by the terminal.

25. The method according to claim 23, characterized in that The method further comprises: The satellite network device determines a time point for sending an ACK based on a remaining time length of the SLC PDU receiving window and a signal processing scheduling delay of the satellite network device.

26. The method according to claim 25, characterized in that The satellite network device determines the time point for sending the ACK using the following formula: tStationSendAck=tStationRevWindow+tStationProcess+δ Among them, tStationSendAck is the time point when the satellite network device sends ACK, tStationRevWindow is the remaining time length of the SLC PDU receiving window, tStationProcess is the signal processing scheduling delay on the satellite network device, and δ is the sending time alignment deviation of the outbound physical frame on the satellite network device.

27. A satellite communication system, characterized in that: include: Terminals and satellite network equipment; among which, The terminal is configured to send a first SLC PDU to a satellite network device, wherein the frame header information of the first SLC PDU includes a first total number of frames field and a first frame sequence number field, and the first total number of frames field and the first frame sequence number field are used to combine and indicate an acknowledgment mode that the terminal requests the satellite network device to adopt; the satellite network device being configured to send a first ACK to the terminal when the confirmation mode indicated by the combination of the first total number of frames field and the first frame sequence number field is a parallel confirmation mode; The first ACK is used to indicate the frame sequence number of the SLC PDU that the satellite network device has not received in the N SLC PDUs of the first SLC SDU, the N SLC PDUs of the first SLC SDU include the first SLC PDU, the first total number of frames field is used to indicate the total number N of SLC SDUs in the first SLC PDU, and the first frame sequence number field is used to indicate the frame sequence number of the first SLC PDU in the first SLC SDU; The terminal is further configured to, after receiving the first ACK, retransmit the SLC PDU in the first SLC SDU that the satellite network device has not received to the satellite network device.

28. A communication device, characterized in that: The communication device comprises one or more processors, one or more memories, and a transceiver; wherein the transceiver and the one or more memories are coupled to the one or more processors, the one or more memories are used to store computer program code, and the computer program code includes computer instructions. When the one or more processors execute the computer instructions, the communication device executes the method according to any one of claims 1 to 16.

29. The communication device according to claim 28, wherein: The communication device is a terminal.

30. A communication device, characterized in that: The communication device comprises one or more processors, one or more memories, and a transceiver; wherein the transceiver and the one or more memories are coupled to the one or more processors, the one or more memories are used to store computer program code, and the computer program code includes computer instructions. When the one or more processors execute the computer instructions, the communication device executes the method according to any one of claims 17 to 26.

31. The communication device according to claim 30, wherein: The communication device is a satellite network device.

32. A computer-readable storage medium, wherein instructions are stored in the computer-readable storage medium, and when the instructions are executed on a computer, the computer is caused to execute the method according to any one of claims 1 to 16.

33. A computer-readable storage medium, wherein instructions are stored in the computer-readable storage medium, and when the instructions are executed on a computer, the computer is caused to execute the method according to any one of claims 17 to 26.

34. A chip system, applied to a terminal, characterized in that: The method comprises a processing circuit and an interface circuit, wherein the interface circuit is used to receive code instructions and transmit the code instructions to the processing circuit, and the processing circuit is used to run the code instructions to execute the method according to any one of claims 1 to 16.

35. A chip system, applied to satellite network equipment, characterized in that: The method comprises a processing circuit and an interface circuit, wherein the interface circuit is used to receive code instructions and transmit the code instructions to the processing circuit, and the processing circuit is used to run the code instructions to execute the method according to any one of claims 17 to 26.

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