A method and system for establishing a point-to-point data transmission link based on Tiantong satellites

Abstract

A method and system for establishing a point-to-point data transmission link based on Tiantong satellites. An IP address is allocated according to a request for establishing a data transmission link initiated by a first terminal, and a first dedicated protocol frame is generated with the first IP address, an instruction for establishing a data transmission link, and first configuration information. According to the identification number of a second terminal, the first dedicated protocol frame is sent to the second terminal through the control channel of the Tiantong satellite mobile communication network; the first dedicated protocol frame received by the second terminal is judged and parsed to obtain the first IP address, the first configuration information, and the instruction for establishing a data transmission link, and the second terminal is configured according to the first configuration information; a second IP address is allocated according to a request initiated by the second terminal in response to the instruction for establishing a data transmission link, and a data transmission link is established according to the first IP address and the second IP address. The present invention can quickly establish and maintain a data transmission link, without occupying a large amount of service channel resources of the Tiantong satellite mobile communication network, with high efficiency and strong real-time performance.

Description

Technical Field

[0001] The present invention relates to the field of Tiantong communication, and in particular to a method and system for establishing a point-to-point data transmission link based on Tiantong satellites. Background Art

[0002] Currently, Tiantong satellite phones have been widely used in fields such as emergency rescue, wilderness exploration, geological exploration, and ocean fishing. The Tiantong-1 satellite mobile communication system supports three communication services: voice, short message, and data. The short message service of the Tiantong terminal uses the phone number as the destination address to communicate with the peer end. The disadvantage is that each time it can only send a short message data packet not greater than 140 bytes, and the real-time performance of the short message is poor. When the network is busy, the arrival time of the short message cannot be predicted. The voice service of the Tiantong terminal also uses the phone number as the destination address to communicate with the peer end. This method has good real-time performance, but the disadvantage is that the communication rate is limited to 2.4 kbps, the bandwidth is narrow, it must be kept online during the call, the cost is expensive, and each communication can only be point-to-point and cannot be networked.

[0003] With the development of satellite mobile Internet technology, the usage demand for Tiantong satellite data services is also growing rapidly. The Tiantong terminal can perform data communication between the Tiantong satellite data service and the Internet. The communication rate is generally 9.6 kbps, and the communication rate of some special devices can reach up to 384 kbps at most. The Internet uses a fixed IP or domain name as the destination address, and the Tiantong terminal connects to the server for two-way data communication.

[0004] Due to the shortage of satellite resources, the system cannot ensure that every terminal can apply for and occupy data service resources in real time, and long-term occupation of data service resources will incur expensive costs. Therefore, the Tiantong-1 satellite mobile communication system data service adopts a technical system of dynamically allocating IP addresses. Each time the Tiantong terminal applies for data service resources, the IP address assigned by the gateway station may be different, resulting in users being unable to accurately establish a point-to-point data transmission link through the Tiantong satellite mobile communication network. Especially in some special application scenarios, due to reasons such as security factors, it is not convenient to set up an intermediate server, or in some cases where an intermediate server cannot be set up due to certain factors, there will be a problem of IP address addressing failure when the Tiantong terminal performs point-to-point intercommunication through the data service. In addition, currently, the Tiantong terminal mainly obtains relevant parameters and status through manual phone calls or setting up dedicated servers to establish a data transmission link. Summary of the Invention

[0005] The main purpose of the present invention is to overcome the above-mentioned defects in the prior art, and propose a method and system for establishing a point-to-point data transmission link based on Tiantong satellites, which can quickly complete the establishment and maintenance of the data transmission link without occupying a large amount of service channel resources of the Tiantong satellite mobile communication network, and has high efficiency and strong real-time performance.

[0006] The present invention adopts the following technical solutions:

[0007] A method for establishing a point-to-point data transmission link based on Tian Tong satellites, which respectively configures the identification numbers of a first terminal and a second terminal accessing the Tian Tong satellite mobile communication network, includes:

[0008] Allocate a first IP address according to the request for establishing a data transmission link initiated by the first terminal, generate a first dedicated protocol frame with the first IP address, the instruction for establishing the data transmission link, and the first configuration information of the first terminal, and send the first dedicated protocol frame to the second terminal through the control channel of the Tian Tong satellite mobile communication network according to the identification number of the second terminal;

[0009] Judge and analyze the first dedicated protocol frame received by the second terminal to obtain the first IP address, the first configuration information, and the instruction for establishing the data transmission link, and configure the second terminal according to the parsed first configuration information;

[0010] Allocate a second IP address according to the request initiated by the second terminal in response to the instruction for establishing the data transmission link, and establish a data transmission link according to the first IP address and the second IP address;

[0011] The first terminal and the second terminal automatically maintain the data transmission link according to the status of the Tian Tong satellite mobile communication network.

[0012] Generate a first dedicated protocol frame with the first IP address, the instruction for establishing the data transmission link, and the first configuration information of the first terminal, specifically as follows:

[0013] Use the first IP address, the instruction for establishing the data transmission link, and the first configuration information of the first terminal as protocol data; configure a fixed format header and a fixed format tail, form a string with the fixed format header, the protocol data, and the fixed format tail, then encrypt the string using a custom fixed key encryption and decryption method, perform a CRC check on the encrypted string, and add the CRC check code after the encrypted string to form the first dedicated protocol frame.

[0014] Judge and analyze the first dedicated protocol frame received by the second terminal to obtain the first IP address, the first configuration information, and the instruction for establishing the data transmission link, specifically including the following:

[0015] First, perform CRC check on the first dedicated protocol frame. If the CRC check is successful, extract the encrypted string. Then, decrypt the encrypted string to obtain the original data string after successful decryption. Finally, parse the original data string to obtain the first IP address, the first configuration information, and the instruction for establishing a data transmission link.

[0016] In the protocol data of the first dedicated protocol frame, there are arranged in sequence a transmission timestamp, the first IP address, the first configuration information, and the instruction for establishing a data transmission link. Parsing the original data string to obtain the first IP address, the first configuration information, and the instruction for establishing a data transmission link specifically includes the following:

[0017] First, determine whether the fixed format header and fixed format tail in the string are correct. If correct, then determine whether the transmission of the first dedicated protocol frame times out according to the transmission timestamp. If it does not time out, extract the first IP address, the first configuration information, and the instruction for establishing a data transmission link.

[0018] The instruction for establishing a data transmission link is the relevant operation instruction of the data transmission link configured according to the request for establishing a data transmission link.

[0019] The instruction for establishing a data transmission link includes an operation instruction for establishing a data transmission link and is configured as:

[0020] When the instruction for establishing a data transmission link is the first instruction, it is defined that the sending end actively initiates the establishment of a data transmission link and reports the IP address. The receiving end sets the operation instruction of the data transmission link as the second instruction and returns its own IP address to the sending end. Then, the receiving end establishes a data transmission link.

[0021] When the instruction for establishing a data transmission link is the second instruction, it is defined that the sending end actively initiates the deletion of the data transmission link, the sending end reports its own IP address, the receiving end deletes the corresponding data transmission link and releases the data service resources of the Tiantong satellite mobile communication network. The terminal automatically replies with an acknowledgment. The sending end receives the IP address returned by the receiving end and establishes a data transmission link.

[0022] When the instruction for establishing a data transmission link is the third instruction, the receiving end automatically replies with an acknowledgment. The sending end receives the IP address returned by the receiving end and establishes a data transmission link.

[0023] The first terminal or the second terminal maintains the data transmission link by initiating a request to maintain the data transmission link, wherein the instruction to maintain the data transmission link is a related operation instruction of the data transmission link configured according to the request to maintain the data transmission link, and the instruction to maintain the data transmission link includes a maintenance operation instruction of the data transmission link and is configured as follows:

[0024] When the instruction for maintaining the data transmission link is the fourth instruction, it means that the IP address of the sender has changed. The sender reports the new IP address, then deletes the original data transmission link, and then re-establishes the data transmission link based on the new IP address; the receiving end receives the notification of the change in the sender's IP address, obtains the sender's new IP address, then deletes the original data transmission link, and then re-establishes the data transmission link based on the new IP address;

[0025] The instruction to maintain the data transmission link is the fifth instruction, which indicates that the sending end has a fault and the data transmission link is disconnected;

[0026] The instruction to maintain the data transmission link is the sixth instruction, which indicates that the number of data links of the sending end exceeds the upper limit of the carrying capacity and the data transmission link cannot be established.

[0027] Establishing a data transmission link based on the first IP address and the second IP address means autonomously establishing a data transmission link across the Tiantong satellite mobile communication network through GRE tunnel mode or NAT penetration mode; the first IP address includes the IP address of the Tiantong satellite mobile communication network of the first terminal and the IP address of the service network port; the second IP address includes the IP address of the Tiantong satellite mobile communication network of the second terminal and the IP address of the service network port; the first configuration information includes the identification number of the first terminal, the local service network port IP address and gateway, the service rate and the data transmission link establishment method.

[0028] A second IP address is allocated according to the request initiated by the second terminal in response to the instruction to establish the data transmission link, and a second dedicated protocol frame is generated by the second IP address, the configuration information of the second terminal and the response to the instruction to establish the data transmission link. According to the identification number of the first terminal, the second dedicated protocol frame is sent to the first terminal through the control channel of the Tiantong satellite mobile communication network; the first terminal and the second terminal automatically maintain the data transmission link through the first dedicated protocol frame and the second dedicated protocol frame respectively, and update and report the status of the data transmission link.

[0029] A system for establishing a point-to-point data transmission link based on Tiantong satellite, comprising:

[0030] The first terminal initiates a request to establish a data transmission link and obtains the allocated first IP address, generates a first dedicated protocol frame with the first IP address, the instruction to establish the data transmission link, and the first configuration information of the first terminal, and sends the first dedicated protocol frame to the second terminal through the control channel of the Tiantong satellite mobile communication network according to the identification number of the second terminal, and automatically maintains the data transmission link according to the state of the Tiantong satellite mobile communication network;

[0031] The second terminal receives the first dedicated protocol frame, judges and parses it to obtain the first IP address, the first configuration information, and the instruction to establish the data transmission link, and configures according to the parsed first configuration information; responds to the request initiated by the establishment of the data transmission link to allocate a second IP address; establishes a data transmission link according to the first IP address and the second IP address, and automatically maintains the data transmission link according to the state of the Tiantong satellite mobile communication network;

[0032] The gateway station receives the request from the first terminal to establish a data transmission link and allocates the first IP address.

[0033] A host is provided in the first terminal or the second terminal; the host includes a CP module, an AP module, and a service network card; the CP module is used to access the Tiantong satellite mobile communication network, apply for data service resources of the Tiantong satellite mobile communication network, and send the dedicated protocol frame through the control channel; the AP module is used to set configuration information, initiate an application for data service resources of the Tiantong satellite mobile communication network, obtain and monitor the IP address, send, receive, and parse the dedicated protocol frame, and monitor and manage the data transmission link; the service network card is used to access the local local area network and realize data network communication between the local local area network and the AP module.

[0034] As can be seen from the above description of the present invention, compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. In the present invention, the first terminal generates a first dedicated protocol frame with the first IP address, the instruction of the data service, and the first configuration information, and sends the first dedicated protocol frame to the second terminal through the control channel of the Tiantong satellite mobile communication network according to the identification number of the second terminal; the first IP address, the first configuration information, and the instruction of the data service are obtained by judging and parsing the dedicated protocol frame received by the second terminal, the second terminal is configured according to the parsed first configuration information, and the second IP address is obtained. A data transmission link is established based on the first IP address and the second IP address, and the data transmission link is automatically maintained according to the status of the Tiantong satellite mobile communication network. Without occupying a large amount of service channel resources of the Tiantong satellite mobile communication network, only a small amount of control channel resources of the Tiantong satellite mobile communication network are used, and the interaction of the data transmission link configuration information can be quickly completed, with high efficiency and strong real-time performance.

[0036] 2. In the present invention, by automatically collecting the data transmission link configuration information to generate dedicated protocol frame data, the multiplexing of the control channel of the Tiantong satellite mobile communication network is realized through a specific encryption method and a CRC check method, the screening and filtering of the dedicated protocol frame data are efficiently completed, and the security and reliability of the dedicated protocol frame data are ensured.

[0037] 3. In the present invention, the first terminal or the second terminal can efficiently and quickly establish and maintain a data transmission link by executing processing procedures such as judging and parsing the dedicated protocol frame, monitor and report the working status of the data transmission link in real time, and give a prompt and perform exception handling when the transmission link is abnormal, ensuring the stable and reliable operation of the transmission link and supporting multiple working modes and usage scenarios.

[0038] 4. In the present invention, a mesh topology structure is adopted, and no dedicated server is required. It is a centerless self-organizing link transmission method, which has strong scalability, flexibility and self-organizing ability, small risk of network paralysis, can effectively save satellite resources and reduce usage costs; there is no need to repeatedly confirm parameters and status by making calls manually to establish a transmission link, and only the identification number of the peer device needs to be input to automatically establish a data transmission link, with simple operation and convenient and fast use. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is the main flow chart of the present invention;

[0040] Figure 2 is the work flow chart of the first terminal;

[0041] Figure 3 the structure diagram of the dedicated protocol frame;

[0042] Figure 4 is the receiving flow chart of the dedicated protocol frame;

[0043] Figure 5 It is a flowchart for judging and analyzing a dedicated protocol frame;

[0044] Figure 6 It is an interaction flowchart of the method of the present invention;

[0045] Figure 7 Structural diagram of the first terminal or the second terminal;

[0046] Figure 8 It is a network topology diagram of the present invention.

[0047] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. Specific embodiments

[0048] The present invention will be further described below through specific embodiments.

[0049] See Figures 1 to 6 , a method for establishing a point-to-point data transmission link based on Tiantong satellite. The identification numbers for accessing the Tiantong satellite mobile communication network of the first terminal A and the second terminal B are pre-configured respectively. The identification number is the authentication of the first terminal A or the second terminal B and is the only identifier for verifying the user identity and permissions. For example, it is a SIM card number, but not limited thereto. The method includes:

[0050] S1 Allocate a first IP address according to the request of the data service initiated by the first terminal A, generate a first dedicated protocol frame with the first IP address, the instruction for establishing a data transmission link, and the first configuration information of the first terminal A, and send the first dedicated protocol frame to the second terminal B through the control channel of the Tiantong satellite mobile communication network according to the identification number of the second terminal B.

[0051] Among them, after the first terminal A is powered on, it automatically completes network access registration and sets the first configuration information. The first configuration information includes the data service rate of the Tiantong satellite mobile communication network, the local service network port IP address and gateway, and the data link establishment method, etc. The identification number of the first terminal A is also the first configuration information, which is pre-configured.

[0052] When the first terminal A initiates a request for a data service, it automatically applies for data service resources of the Tiantong mobile communication network. The data service includes establishing a data transmission link or maintaining an established data transmission link, etc. After the application is successful, it obtains the first IP address assigned to the first terminal A by the gateway station, and then automatically opens the service network port of the first terminal A. The first IP address includes the IP address of the Tiantong satellite mobile communication network and the IP address of the service network port of the first terminal A.

[0053] In this step, generate a first dedicated protocol frame with the first IP address, the instruction for establishing a data transmission link, and the first configuration information of the first terminal A. See Figure 3, as follows:

[0054] Take the first IP address, the instruction to establish a data transmission link, and the first configuration information of the first terminal A as protocol data; configure a fixed format header and a fixed format tail, form a string by combining the fixed format header, the protocol data, and the fixed format tail, then encrypt the string using a custom fixed key encryption and decryption method, perform a CRC check on the encrypted string, and add the CRC check code after the encrypted string to form the first dedicated protocol frame.

[0055] Among them, the instruction to establish a data transmission link is the relevant operation instruction of the data transmission link configured according to the request of the data service, such as including the establishment operation instruction of the data transmission link, etc. In the protocol data, it includes a send timestamp, the first IP address, the first configuration information, and the instruction to establish a data transmission link arranged in sequence. Specifically, the first IP address includes the Tiantong network IP address and the service network port IP address arranged in sequence, and the first configuration information includes the data link establishment method. The elements in the protocol data are arranged according to importance, and this arrangement method can improve the efficiency of data protocol parsing. The protocol data can be encrypted and decrypted using methods such as AES, DES, 3DES, or RSA.

[0056] In the subsequent parsing steps, first extract the protocol data send timestamp and compare it with the protocol data receive timestamp. If it times out, it means that the protocol data is not real-time, and subsequent protocol data will not be parsed; if it does not time out, continue to parse other protocol data. Similarly, then judge whether other elements are legal according to this logic. If they are not legal, do not continue to parse until all elements are legal to perform the relevant operations of the data transmission link.

[0057] In this embodiment, the establishment operation instructions of the data transmission link include the first instruction, the second instruction, and the third instruction, etc. The first instruction, the second instruction, and the third instruction can be distinguished by different values, such as 00, 01, 02 respectively, but not limited to this.

[0058] When the instruction to establish a data transmission link is the first instruction, it is defined that the sending end actively initiates the establishment of a data transmission link and reports the IP address, and the receiving end sets the operation instruction of the data transmission link to the second instruction and returns its own IP address to the sending end, and then the receiving end establishes a data transmission link.

[0059] When the instruction to establish a data transmission link is the second instruction, it is defined that the sending end actively initiates the deletion of the data transmission link, the sending end reports its own IP address, the receiving end deletes the corresponding data transmission link and releases the Tiantong satellite mobile communication network data service resources; the terminal automatically replies with an answer, the sending end receives the IP address returned by the receiving end, and establishes a data transmission link.

[0060] When the instruction to establish a data transmission link is the third instruction, the receiving end automatically replies with an acknowledgement. The sending end receives the IP address sent back by the receiving end and establishes a data transmission link.

[0061] Specifically, configuration parameters such as the IP address of the Tiantong mobile communication network of the first terminal A, the IP address of the service network port, the data transmission link operation instruction, the identification number of the first terminal A, the service rate of the Tiantong satellite mobile communication network, the timestamp of the dedicated protocol frame sending time, and the data link establishment method are used to generate protocol data according to the requirements of the dedicated protocol frame format. A string is formed by combining the fixed format header, the protocol data, and the fixed format tail. Then, the string is encrypted using a custom fixed key encryption and decryption method. Finally, CRC check is performed on the encrypted data, and the check code is added after the encrypted string to form a complete dedicated protocol frame.

[0062] Among them, the dedicated protocol frame structure is shown in Figure 3 Encrypting the protocol data is to ensure the security of the data transmission link and prevent malicious attacks. Adding CRC check is to screen and filter the control channel frame data and prevent errors in the dedicated protocol frame data at the same time.

[0063] In addition, after the first terminal A sends a dedicated protocol frame to the second terminal B through the control channel, for those that require a reply from the other end, a timer for waiting for the reply from the second terminal B can be started. If the timer times out, it is prompted that the second terminal B is not on the network and a data transmission link cannot be established. If the timer does not time out, it enters the dedicated protocol frame reception processing flow. The dedicated protocol frame reception processing flow of the first terminal A is similar to that of the second terminal B.

[0064] S2 judges and analyzes the first dedicated protocol frame received by the second terminal B to obtain the first IP address, the first configuration information, and the instruction to establish a data transmission link, and configures the second terminal B according to the parsed first configuration information.

[0065] After the second terminal B is powered on, it automatically completes network registration. When the second terminal B receives a dedicated protocol frame reported on the control channel, it makes judgments and analyzes it, etc.

[0066] Among them, see Figure 4, first perform CRC check on the first dedicated protocol frame. If the CRC check is successful, extract the encrypted string. If the check fails, the protocol frame data is not a dedicated protocol frame, and the process ends. Then decrypt the encrypted string. After successful decryption, obtain the string of the original data. If the decryption fails, the protocol frame data is not dedicated protocol frame data, and the process ends. Finally, parse the string of the original data to obtain the first IP address, the first configuration information, and the instruction to establish a data transmission link. When parsing, first determine whether the fixed format header and the fixed format tail in the string are correct. If they are correct, then determine whether the transmission of the first dedicated protocol frame times out. If it does not time out, extract the first IP address, the first configuration information, and the instruction to establish a data transmission link.

[0067] For the specific process, see Figure 5 , first check whether the frame header and the frame tail of the dedicated protocol frame are correct. The fixed format header and the fixed format tail are composed of specific string identifiers. For example, the fixed format header string identifier is "abcd", and the fixed format tail string identifier is "efgh". First, extract the data of the first 4 bytes and the last 4 bytes of the string of the dedicated protocol frame, and then compare the first 4 bytes with the string "abcd". If the two are exactly the same, the fixed format header is correct; compare the last 4 bytes with "efgh". If the two are exactly the same, the fixed format tail is correct.

[0068] If any one of the fixed format header and the fixed format tail is incorrect, the dedicated protocol frame data is in error, and the process ends; if both the fixed format header and the fixed format tail are correct, check whether the transmission of the dedicated protocol frame data times out. If it does not time out, extract the data transmission link configuration parameters such as the IP address of the Tiantong mobile communication network, the service network port IP address, and the service rate of the first terminal A, as well as the instruction to establish or maintain a data transmission link, etc.; if the transmission times out, the dedicated protocol frame data is invalid, and the process ends. The second terminal B sets the data service rate of the Tiantong satellite mobile communication network, the local service network port IP address, the gateway, etc. according to the data transmission link configuration parameters.

[0069] S3 allocates a second IP address according to the request initiated by the second terminal B in response to the instruction to establish a data transmission link, and establishes a data transmission link according to the first IP address and the second IP address. The second IP address includes the IP address of the Tiantong satellite mobile communication network and the IP address of the service network port of the second terminal B.

[0070] The second terminal B automatically applies for the data service resources of the Tiantong mobile communication network according to the parsed instruction to establish a data transmission link. After the application is successful, obtain the IP address of the Tiantong mobile communication network assigned by the gateway station to the second terminal B, and then automatically open the service network port of the second terminal B to obtain the IP address of the service network port of the second terminal BB.

[0071] In this step, according to the data transmission link operation instruction in the dedicated protocol frame configuration parameters, the data transmission link configuration information is sent back, and the data transmission link is established or deleted. For different instructions for establishing a data transmission link, the specific operations performed by the second terminal B can be seen in Table 1 in the previous text and Figure 5 The description is as follows:

[0072] If the data transmission link operation instruction is 00, the second terminal B will generate a second dedicated protocol frame with the second IP address, the configuration information of the second terminal B, and the instruction for responding to the establishment of the data transmission link, and send the second dedicated protocol frame to the first terminal A through the control channel of the Tiantong satellite mobile communication network according to the identification number of the first terminal A. The process of generating the dedicated protocol frame of the second terminal B is similar to that of the first terminal A.

[0073] Among them, the instruction for responding to the establishment of the data transmission link is also the third instruction, with a value of 02. The second terminal B establishes a data transmission link according to the first IP address and the second IP address.

[0074] If the data transmission link operation instruction is 01, the data transmission link is deleted, the data service resources of the Tiantong mobile communication network are released, and the service network port is closed.

[0075] If the data transmission link operation instruction is 02, a data transmission link is established according to the first IP address and the second IP address.

[0076] If the data transmission link operation instruction is 03, the original data transmission link is deleted, and a data transmission link is re-established according to the first IP address and the second IP address.

[0077] If the data transmission link operation instruction is 04, 05, or 06, the data transmission link status is updated and reported.

[0078] In this embodiment, establishing a data transmission link according to the first IP address and the second IP address means autonomously establishing a data transmission link across the Tiantong satellite mobile communication network through the GRE tunnel mode or the NAT penetration mode.

[0079] In practical applications, multiple transmission links can also be established simultaneously, supporting one-to-one, one-to-many, and many-to-many usage scenarios. Users can also establish a data transmission link from the first terminal A or the second terminal B to a PC or from a PC to a PC according to needs to achieve network data transmission.

[0080] S4 The first terminal A and the second terminal B automatically maintain the data transmission link according to the status of the Tiantong satellite mobile communication network. After the data transmission link is established, both the first terminal A and the second terminal B maintain the data transmission link.

[0081] In this embodiment, the first terminal A and the second terminal B respectively maintain the data transmission link through the first dedicated protocol frame and the second dedicated protocol frame, and update and report the status of the data transmission link. Correspondingly, the dedicated protocol frame includes instructions for maintaining the data transmission link. In this embodiment, the maintenance operation instructions for the data transmission link include a fourth instruction, a fifth instruction, a sixth instruction, etc.

[0082] When the instruction for maintaining the data transmission link is the fourth instruction, it means that the IP address of the sending end has changed. The sending end reports the new IP address, then deletes the original data transmission link, and then re-establishes the data transmission link according to the new IP address; the receiving end receives the notification that the IP address of the sending end has changed, obtains the new IP address of the sending end, then deletes the original data transmission link, and then re-establishes the data transmission link according to the new IP address.

[0083] When the instruction for maintaining the data transmission link is the fifth instruction, it means that the sending end has a fault and the data transmission link is disconnected. Among them, the sending end fault may include three types: Tiantong mobile communication network fault, service network port fault, or both Tiantong mobile communication network and service network port faults. According to different fault reasons, the fifth instruction can be further divided into three cases, represented by three different values, such as 04, 05, 06.

[0084] When the instruction for maintaining the data transmission link is the sixth instruction, it means that the number of data links at the sending end has exceeded the carrying limit and the data transmission link cannot be established.

[0085] For the values and definitions of the above instructions for establishing or maintaining the data transmission link, reference can be made to Table 1.

[0086] Table 1

[0087]

[0088] Based on this, referring to Figure 7 and Figure 8 , the present invention also proposes a system for establishing a point-to-point data transmission link based on Tiantong satellites, which adopts the above method for establishing a point-to-point data transmission link based on Tiantong satellites, including:

[0089] The first terminal A initiates a request to establish a data transmission link and obtains the allocated first IP address, generates a first dedicated protocol frame with the first IP address, the instruction for establishing the data transmission link, and the first configuration information of the first terminal A, and sends the first dedicated protocol frame to the second terminal B through the control channel of the Tiantong satellite mobile communication network according to the identification number of the second terminal B.

[0090] The second terminal B receives the first dedicated protocol frame, judges and parses it to obtain the first IP address, the first configuration information, and an instruction to establish a data transmission link, and configures according to the parsed first configuration information; responds to the request initiated to establish a data transmission link to allocate a second IP address; establishes a data transmission link according to the first IP address and the second IP address.

[0091] The gateway station receives the request to establish a data transmission link from the first terminal A, allocates the first IP address, forwards the dedicated protocol frame through the control channel, and forwards the service data on the data transmission link through the service channel.

[0092] The first terminal A and the second terminal B are terminals of the Tiantong network. They are equipped with a host and a mobile satellite communication antenna. The maximum data transmission rate can reach 384 kbps, and they can support communication during movement at a speed of 120 km / h without serious signal obstruction. The host and the antenna are connected by a radio frequency cable; the host integrates an AP module, a CP module, and a service network card, etc. The AP module and the CP module communicate through UART, and the AP module and the service network card communicate through USB; the mobile satellite communication antenna integrates an antenna radiation surface, a power amplifier module, an inertial navigation module, a Beidou positioning module, a signal processing module, and a servo control module, etc.

[0093] The AP module is used to set information such as the data service rate of the Tiantong satellite mobile communication network, the IP address and gateway of the service network port, the SIM card number of the peer end, etc., to initiate an application for data service resources of the Tiantong satellite mobile communication network, manage the service network port, obtain an IP address and monitor whether the IP address changes, to send, receive, and parse dedicated protocol frame data, to monitor and manage the data transmission link, and to handle the abnormal state of the data transmission link to ensure the stable and reliable operation of the data transmission link.

[0094] The CP module is used to access the Tiantong satellite mobile communication network, modulate and demodulate the data of the control channel and the service channel, apply for data service resources of the Tiantong satellite mobile communication network, monitor the status of the Tiantong satellite mobile communication network and the data service resource situation and report them to the AP module, send the dedicated protocol frame data to the peer Tiantong device through the control channel, and report the received service channel frame data to the AP module.

[0095] The service network card is used to access the local area network and realize the data network communication between the local area network and the AP module. It can be connected to network devices such as a PC, a switch, or a router through the service network port.

[0096] In the mobile satellite antenna, the antenna radiation surface includes a Beidou signal radiation surface and a Tiantong signal radiation surface. The Tiantong signal radiation surface is used to receive the Tiantong satellite air interface signal and radiate the RF modulated signal output by the power amplifier. The Beidou signal radiation surface is used to receive Beidou satellite signals. The power amplifier module is used for low-noise amplification of the Tiantong satellite downlink signal and the signal transmitted by the CP module, ensuring that the terminal can receive satellite signals with high quality and that the RF modulated signal transmitted by the terminal can reach the satellite. The inertial navigation module collects three-dimensional dynamic data of the antenna movement and feeds it back to the servo control module. The Beidou positioning module realizes the positioning and orientation function of dual Beidou antennas and feeds back the positioning and orientation results to the servo control module. The signal processing module realizes the acquisition and tracking of Tiantong satellite signals and feeds back the acquisition and tracking results to the servo control module in real time. After comprehensively analyzing the results fed back by the signal processing module, the Beidou positioning module, and the inertial navigation module, the servo control module controls the azimuth motor and the elevation motor to complete the functions of aligning with the satellite and continuous tracking, and provides the ability to configure and query the device information inside the antenna externally.

[0097] The terminal of the present invention can automatically access the Tiantong satellite mobile communication network, with a maximum data rate of up to 384 kbps. It is equipped with a service network port and supports the TCP / IP protocol.

[0098] The method and device of the present invention can automatically generate dedicated protocol frame data, automatically screen and filter out the dedicated protocol frame data, and ensure security and reliability. The dedicated protocol frame data is transmitted through the control channel. The maximum length of the dedicated protocol frame data supports 168 bytes. The sending process, receiving process, and parsing process of the dedicated protocol frame are realized, and a point-to-point data transmission link is established and the data transmission link is maintained.

[0099] The terminal of the present invention can automatically access the Tiantong satellite mobile communication network, with a maximum data rate of up to 384 kbps. It is equipped with a service network port and supports the TCP / IP protocol. It can conveniently and quickly establish a data transmission link across the Tiantong satellite mobile communication network at low cost and realize point-to-point data network communication.

[0100] The above is only the specific implementation manner of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantive modification made to the present invention using this concept shall fall within the scope of infringement of the protection of the present invention.

Claims

1. A method for establishing a point-to-point data transmission link based on Tiantong satellites, which respectively configures the identification numbers for a first terminal and a second terminal to access the Tiantong satellite mobile communication network, characterized in that, Including: Allocating a first IP address according to a request for establishing a data transmission link initiated by a first terminal, generating a first dedicated protocol frame with the first IP address, the instruction for establishing the data transmission link, and the first configuration information of the first terminal, and sending the first dedicated protocol frame to the second terminal through a control channel of a Tian Tong satellite mobile communication network according to the identification number of the second terminal; Judging and parsing the first dedicated protocol frame received by the second terminal to obtain the first IP address, the first configuration information, and the instruction for establishing the data transmission link, and configuring the second terminal according to the parsed first configuration information; Allocating a second IP address according to a request initiated by the second terminal in response to the instruction for establishing the data transmission link, and establishing a data transmission link according to the first IP address and the second IP address; The first terminal and the second terminal automatically maintain the data transmission link according to the status of the Tian Tong satellite mobile communication network; The instruction for establishing the data transmission link is a relevant operation instruction of the data transmission link configured according to the request for establishing the data transmission link, The instruction for establishing the data transmission link includes an establishment operation instruction of the data transmission link and is configured as: When the instruction for establishing the data transmission link is a first instruction, it is defined that the sending end actively initiates the establishment of the data transmission link and reports the IP address, the receiving end sets the operation instruction of the data transmission link as a second instruction and returns its own IP address to the sending end, and then, the receiving end establishes the data transmission link; When the instruction for establishing the data transmission link is a second instruction, it is defined that the sending end actively initiates the deletion of the data transmission link, the sending end reports its own IP address, and the receiving end deletes the corresponding data transmission link and releases the data service resources of the Tian Tong satellite mobile communication network; The terminal automatically replies with an acknowledgment, and the sending end establishes a data transmission link after receiving the IP address returned by the receiving end; When the instruction for establishing the data transmission link is a third instruction, the receiving end automatically replies with an acknowledgment, and the sending end establishes a data transmission link after receiving the IP address returned by the receiving end.

2. The method for establishing a point-to-point data transmission link based on Tiantong satellite according to claim 1, characterized in that, Generating a first dedicated protocol frame with the first IP address, the instruction for establishing the data transmission link, and the first configuration information of the first terminal is specifically as follows: Taking the first IP address, the instruction for establishing the data transmission link, and the first configuration information of the first terminal as protocol data; configuring a fixed format header and a fixed format tail, forming a string with the fixed format header, the protocol data, and the fixed format tail, then encrypting the string by using a custom fixed key encryption and decryption method, performing a CRC check on the encrypted string, and adding the CRC check code after the encrypted string to form the first dedicated protocol frame.

3. The method for establishing a point-to-point data transmission link based on Tiantong satellites according to claim 2, wherein Judging and parsing the first dedicated protocol frame received by the second terminal to obtain the first IP address, the first configuration information, and the instruction for establishing the data transmission link specifically includes the following: First, perform CRC check on the first dedicated protocol frame. If the CRC check is successful, extract the encrypted string. Then, decrypt the encrypted string. After successful decryption, obtain the string of the original data. Finally, parse the string of the original data to obtain the first IP address, the first configuration information, and the instruction for establishing a data transmission link.

4. The method for establishing a point-to-point data transmission link based on Tian Tong satellite according to claim 3, wherein, Among the protocol data in the first dedicated protocol frame, there are arranged in sequence a transmission timestamp, the first IP address, the first configuration information, and the instruction for establishing a data transmission link. Parsing the string of the original data to obtain the first IP address, the first configuration information, and the instruction for establishing a data transmission link specifically includes the following: First, determine whether the fixed-format header and the fixed-format tail in the string are correct. If they are correct, then determine whether the transmission of the first dedicated protocol frame times out according to the transmission timestamp. If it does not time out, extract the first IP address, the first configuration information, and the instruction for establishing a data transmission link.

5. A method for establishing a point-to-point data transmission link based on Tiantong satellites, as described in claim 1, characterized in that The first terminal or the second terminal maintains the data transmission link by initiating a request for maintaining the data transmission link. The instruction for maintaining the data transmission link is the relevant operation instruction of the data transmission link configured according to the request for maintaining the data transmission link. The instruction for maintaining the data transmission link includes the maintenance operation instruction of the data transmission link and is configured as: When the instruction for maintaining the data transmission link is the fourth instruction, it means that the IP address of the sending end has changed. The sending end reports the new IP address, then deletes the original data transmission link, and then re-establishes the data transmission link according to the new IP address. The receiving end receives the notice that the IP address of the sending end has changed, obtains the new IP address of the sending end, then deletes the original data transmission link, and then re-establishes the data transmission link according to the new IP address. The instruction for maintaining the data transmission link is the fifth instruction, which means that the sending end has a fault and the data transmission link is disconnected. The instruction for maintaining the data transmission link is the sixth instruction, which means that the number of data links of the sending end has exceeded the bearing limit and a data transmission link cannot be established.

6. The method for establishing a point-to-point data transmission link based on Tiantong satellites as claimed in claim 1, wherein Establishing a data transmission link according to the first IP address and the second IP address means autonomously establishing a data transmission link across the Tiantong satellite mobile communication network through the GRE tunnel mode or the NAT penetration mode. The first IP address includes the IP address of the Tiantong satellite mobile communication network and the IP address of the service network interface of the first terminal. The second IP address includes the IP address of the Tiantong satellite mobile communication network and the IP address of the service network interface of the second terminal. The first configuration information includes the identification number of the first terminal, the local service network interface IP address and gateway, the service rate, and the data transmission link establishment method.

7. A method for establishing a point-to-point data transmission link based on Tiantong satellites according to claim 1, characterized in that, Upon receiving the instruction to establish a data transmission link, the second terminal initiates a request to allocate a second IP address, generates a second dedicated protocol frame with the second IP address, the configuration information of the second terminal, and the instruction to establish the data transmission link, and sends the second dedicated protocol frame to the first terminal via the control channel of the Tiantong satellite mobile communication network according to the identification number of the first terminal; the first terminal and the second terminal automatically maintain the data transmission link and report the status of the data transmission link through the first dedicated protocol frame and the second dedicated protocol frame respectively.

8. A system for establishing a point-to-point data transmission link based on Tian Tong satellites, characterized in that, A method for establishing a point-to-point data transmission link based on Tiantong satellite, which is used to execute any one of claims 1 to 7, includes: The first terminal initiates a request to establish a data transmission link and obtains the allocated first IP address, generates a first dedicated protocol frame with the first IP address, the instruction to establish the data transmission link, and the first configuration information of the first terminal, and sends the first dedicated protocol frame to the second terminal via the control channel of the Tiantong satellite mobile communication network according to the identification number of the second terminal, and automatically maintains the data transmission link according to the status of the Tiantong satellite mobile communication network; The second terminal receives the first dedicated protocol frame, judges and parses it to obtain the first IP address, the first configuration information, and the instruction to establish the data transmission link, configures according to the parsed first configuration information; initiates a request to allocate a second IP address in response to the establishment of the data transmission link; establishes a data transmission link according to the first IP address and the second IP address, and automatically maintains the data transmission link according to the status of the Tiantong satellite mobile communication network; The gateway station receives the request from the first terminal to establish a data transmission link and allocates the first IP address.

9. A system for establishing a point-to-point data transmission link based on Tiantong satellites as claimed in claim 8, characterized in that A host is provided in the first terminal or the second terminal; the host includes a CP module, an AP module, and a service network card; the CP module is used to access the Tiantong satellite mobile communication network, apply for data service resources of the Tiantong satellite mobile communication network, and send the dedicated protocol frame through the control channel; the AP module is used to set configuration information, initiate an application for data service resources of the Tiantong satellite mobile communication network, obtain and monitor the IP address, send, receive, and parse the dedicated protocol frame, and monitor and manage the data transmission link; the service network card is used to access the local area network and realize data network communication between the local area network and the AP module.

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