ATN B2 application system and method for civil aviation broadband communication

Abstract

The invention discloses an ATN B2 application system and method for civil aviation broadband communication, and belongs to the technical field of aviation broadband communication.The system comprises a user management module, a contract management module, a message management module, a data receiving and transmitting module and an interface operation module. The feasibility of an air-ground broadband communication system based on the ATN B2 standard is developed and verified; a set of relatively complete and efficient aviation broadband communication system and a corresponding method are developed by integrating a current data transmission network and a communication monitoring function design scheme.

Description

Technical Field

[0001] This invention relates to the field of aviation broadband communication technology, and in particular to an ATN B2 application system and method for civil aviation broadband communication. Background Technology

[0002] With increasingly frequent cross-border and cross-regional business communications and leisure exchanges, competition for civil aviation airspace resources and conflicts related to safety issues such as flight delays are becoming increasingly serious. Efficient and safe air transport has become a key concern for users. Furthermore, collisions and air disasters caused by untimely scheduling reflect that flight safety and efficient interconnectivity are currently the focus of ATM development, and the technological upgrades and updates in the field of Air Traffic Control (ATC) urgently need to be addressed. To address the challenges of flight trajectory analysis and efficient scheduling in limited airspace, four-dimensional flight path data link technology has emerged and become the cornerstone of the next generation of air traffic management.

[0003] Currently, facing the current situation of radio frequency congestion, the development and use of digital link systems are gradually demonstrating their advantages. The core objective of ATN is to provide stable and reliable end-to-end communication services for aircraft. Its reliability is mainly reflected in two key aspects: air-to-ground information transmission rate and aircraft status interaction. Air-to-ground and ground-to-ground communication has become the key to improving system security, increasing airspace resource allocation efficiency, and saving operating costs. Summary of the Invention

[0004] The purpose of this invention is to provide an ATN B2 application system and method for civil aviation broadband communication, which verifies system functions from multiple dimensions such as connectivity testing, contract testing, communication testing, and encoding / decoding testing, and realizes a near real-time aviation communication and surveillance platform with high integrity and scalability.

[0005] To achieve the above objectives, the present invention provides an ATN B2 application system for civil aviation broadband communication, including a user management module, a contract management module, a message management module, a data transmission and reception module, and a user interface operation module. The user management module is used to implement aircraft identity authentication, connection status management and service authorization functions, and manages the entire process of aircraft login, status maintenance and connection control. The contract management module is used to sign service contracts according to actual needs and to help ground equipment obtain the aircraft's in-flight status. The message management module is responsible for message encapsulation, parsing, and interface display. Message encapsulation and parsing are performed on a single application. Messages generated by the application front-end are used for unified processing of the generation, parsing, storage, status tracking, and logging of various messages in the system. The data transceiver module is used to enable interconnection between ground-based and airborne application equipment; The interface operation module is responsible for dynamically loading or disabling the corresponding application interface based on user requests and system events.

[0006] Preferably, the contract management module includes a contract storage unit for storing contract entities. The contract entity includes a contract ID, contract type, contract request message element, timer module required for periodic contracts and its corresponding ID, contract trigger event and requirement content marker.

[0007] Preferably, the message management module includes a message encapsulation module, a message parsing module, a message management module, and a message display module.

[0008] This invention also provides an ATN B2 application method for civil aviation broadband communication, which employs the aforementioned ATN B2 application system for civil aviation broadband communication and includes the following steps: S1. The aircraft initiates a login request to the onboard terminal through the CM application and uses the user management module for identity authentication and service authorization. S2. After authorization is completed, the system will authorize the ADS-C application and the CPDLC application. If the ADS-C application is started, proceed to S3; if the CPDLC application is started, proceed to S5. After S3, identity authentication, and service authorization are completed, a contract will be signed according to the requirements. S4. After signing the contract, enter the contract management module, and the system will work according to the contract model; S5. During operation, data exchange between the airborne and ground ends is carried out through the message management module and the data transceiver module.

[0009] Preferably, process S1 includes the following steps: S11. The aircraft initiates a login request to the onboard terminal via the CM application; S12. After receiving the request, the user management module receives and parses the key parameters and supported application types, and forwards the key parameters and supported application types to the ground terminal for review. S13. The ground terminal determines whether to allow access based on the policy. If it refuses, it returns a rejection reason code and terminates the session. If it accepts, it updates the status of the aircraft in the system to "logged in" and proceeds to S14. S14. Generate the corresponding connection identifier, complete the aircraft's registration in the ground system, and complete identity authentication and service authorization.

[0010] Preferably, the process of S2 is as follows: S21. After the airborne terminal login is completed, the system automatically authorizes the ADS-C application and the CPDLC application. The initial state of both the ADS-C application and the CPDLC application is "not started". S22. The user management module maintains the application connection status of each logged-in aircraft through a state mechanism. S23. The bottom controller initiates "establish contact" and "start service" commands to the ADS-C application and CPDLC application through the CM application, and activates the corresponding application as needed. If the ADS-C application is started, proceed to S3; if the CPDLC application is started, proceed to S5.

[0011] Preferably, the process of S3 is as follows: S31. After starting the ADS-C application, establish a contract request based on the key parameters in S1. S32. Traverse all contracts in the contract library. If a contract with the same ID exists, create a timer as required and proceed to S35; otherwise, proceed to S33. S33. Check the number of contracts in the contract library. If the number of contracts has reached 256, reject the access of new contracts and send a reminder to the interface operation module; otherwise, create a new contract node. S34. Create timers on demand in the new contract node, and increment the contract quantity counter by 1 at the same time; S35. Enter the contract management module.

[0012] Preferably, the process of S4 is as follows: S41. After receiving the contract information, the contract management module determines the flight status. If the flight is in an emergency, it determines the contract type and returns an error message. The flight remains in an emergency and sends an emergency notification to the ground terminal. Otherwise, proceed to S42. S42. Pilots process contracts according to three different types: cycle, event, and demand, and receive different contract reports. S43. Determine if there is an emergency alert in the contract report. If so, switch the flight status to emergency mode and send an emergency status notification to the ground terminal. Otherwise, send an emergency status notification directly to the ground terminal.

[0013] Preferably, the process of S5 is as follows: S51. During operation, the ground and airborne terminals continuously generate various messages. S52. The message at one end generates a binary message according to the code framework of the unified encoding and decoding of aviation messages using ASN.1 syntax and UPER encoding, based on the user's selection and event input. S53. The binary message is transmitted to the other end through the data transceiver module, and the other end decodes the message through UPER. S54. Extract the decoded data, extract the key fields and convert them back into structured data, and then output and print the data through ASN.1. S55. Display the printed data through the front end.

[0014] Therefore, this invention adopts the above-mentioned structure to develop and verify the feasibility of an air-to-ground broadband communication system based on the ATN B2 standard for civil aviation broadband communication. It integrates current data transmission network and communication monitoring function design schemes to develop a relatively complete and efficient aviation broadband communication system and corresponding methods.

[0015] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0016] Figure 1 This is a diagram illustrating the overall system framework of an ATN B2 application system and method for broadband communication in civil aviation according to the present invention. Figure 2 This is a diagram showing the three main application functions of the ATN B2 application system and method for broadband communication in civil aviation according to the present invention. Figure 3 This diagram illustrates an ATN B2 application system and method for civil aviation broadband communication, based on the present invention, initiating a login request to the airborne terminal via a CM application. Figure 4 This is a diagram illustrating the contract signing process for an ATN B2 application system and method for civil aviation broadband communication according to the present invention. Figure 5 This is a schematic diagram of the contract processing flow of an ATN B2 application system and method for civil aviation broadband communication according to the present invention. Figure 6 This is a flowchart of the periodic contract processing of an ATN B2 application system and method for civil aviation broadband communication according to the present invention. Figure 7 This is a flowchart of the event-type contract processing of an ATN B2 application system and method for civil aviation broadband communication according to the present invention. Figure 8 This is a flowchart illustrating the data exchange between the airborne and ground terminals in an ATN B2 application system and method for civil aviation broadband communication according to the present invention. Figure 9 This is a flowchart illustrating the data transmission process of the data transceiver module in the ATN B2 application system and method for civil aviation broadband communication according to the present invention. Detailed Implementation

[0017] Example To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0019] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0020] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed when in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0021] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0023] like Figures 1-9 As shown, the present invention provides an ATN B2 application system for civil aviation broadband communication, comprising a user management module, a contract management module, a message management module, a data transmission and reception module, and a user interface operation module. Based on the ATN B2 standard and following the air-to-ground communication, navigation, and surveillance application development framework, we completed the design, development, and verification of three applications: Context Management (CM), Automatic Dependent Surveillance-Contractual (ADS-C), and Controller-Pilot Data Link Communication System (CPDLC). 1. An application framework is built by introducing the ATN / IPS network architecture, and the development of aviation broadband data link applications is divided into modules and defined in terms of function, clarifying that the platform is designed for application layer development. Data is transmitted in bitstream form according to international standards, using the UDP transmission protocol, ultimately achieving multi-modal data link compatibility for scenarios including but not limited to VDL Mode2, LDACS, 4G / 5G, and satellite communication, realizing the link between civil aviation and satellite communication.

[0024] 2. By introducing ICAO and RTCA standards, a systematic model of the three major applications CM, ADS-C and CPDLC in the ATN B2 system is carried out. By decomposing the communication and monitoring functions into structured message elements and state machine logic, a message encoding and decoding framework based on ASN.1 syntax and UPER encoding is designed and the communication process is optimized. Then, according to the operation of the air-to-ground dual-end interface, a message flow conforming to the standard is generated to realize a high-reliability air-to-ground data link application system based on ATN B2. 3. Using the ATN B2 application system as the core framework, expand to support quick human-machine interaction and multi-link communication capabilities. Develop a front-end and back-end separated visual interface using the Qt framework. Implement session management through CM, contract negotiation and status monitoring through ADS-C, and command and free text communication through CPDLC. Verify system functions through multiple dimensions such as connectivity testing, contract testing, communication testing, and encoding / decoding testing to achieve a near real-time aviation communication and surveillance platform with high integrity and scalability.

[0025] The user management module is used to implement aircraft identity authentication, connection status management and service authorization functions, and manages the entire process of aircraft login, status maintenance and connection control. The contract management module is used to sign service contracts according to actual needs and to help ground equipment obtain the aircraft's in-flight status. The message management module is responsible for message encapsulation, parsing, and interface display. Message encapsulation and parsing are performed on a single application. Messages generated by the application front-end are used for unified processing of the generation, parsing, storage, status tracking, and logging of various messages in the system. The data transceiver module is used to enable interconnection between ground-based and airborne application equipment; The interface operation module is responsible for dynamically loading or disabling the corresponding application interface based on user requests and system events. As the central module, it is responsible for dynamically loading or disabling the corresponding application interface (such as CM, ADS-C, CPDLC interface) based on user requests (such as clicking an application icon) or system events (such as receiving a login request). It maintains a global application registry, recording the entry function, resource path, and current state of each application.

[0026] The implementation process involves linking the front-end and back-end interface logic to ensure the normal operation of the system, and using graphical components to control the encapsulated interface functions and other additional logic of the above modules.

[0027] The contract management module includes a contract storage unit for storing contract entities. Each contract entity includes a contract ID, contract type, contract request message element, timer modules required for periodic contracts and their corresponding IDs, contract trigger events, and requirement content markers.

[0028] The message management module includes a message encapsulation module, a message parsing module, a message management module, and a message display module.

[0029] This invention also provides an ATN B2 application method for civil aviation broadband communication. Running on two computers, it simulates the airborne and ground terminals in actual use, verifying the system's ability to operate under 5G and WIFI conditions. It provides abstract interfaces and integration solutions for multiple links such as VHF, satellite, and 5G for air-to-ground data link systems, achieving bidirectional compatibility with domestic air traffic control platforms and international standards, and possessing high scalability and engineering portability. It provides a complete development methodology from standard analysis, design implementation, testing and verification to application deployment, possessing industry reference value. The ATN B2 application system for civil aviation broadband communication includes the following steps: S1. The aircraft initiates a login request to the onboard terminal through the CM application and uses the user management module for identity authentication and service authorization. The CM application establishes the connection and address acquisition between the airborne and ground terminals by building an IPv6 transmission network and establishing listening threads and interface functions. It also uses a user list to display user and application usage status, with the backend controlling the application's usage status.

[0030] The context management application includes functions such as establishing and disconnecting air-to-ground connections, obtaining application version addresses, establishing and disconnecting ground connections, and updating application addresses. This application can provide connections for 256 applications and offer services such as login, communication, updates, and forwarding to the air-to-ground data link system. The contractual automatic dependent surveillance application can acquire basic information such as aircraft location, weather conditions, speed, and altitude at fixed intervals or on a single occasion, providing four types of contracts: periodic, event-based, demand-based, and emergency. When in a periodic contract state, the system continuously sends aircraft status information at specified intervals until the periodic instruction is canceled. In an event contract state, a specified event is used as a trigger condition; when the aircraft status is detected outside a fixed range, the current flight status is sent, allowing ground control to monitor whether the aircraft is flying as planned. In a demand contract state, the aircraft will send parameters within a specified range on a single occasion based on ground-initiated demands. When the aircraft is in an emergency state, all contract states are suspended, with the emergency contract having the highest priority, reporting the current flight status to the ground until the emergency is canceled. The controller-pilot data link communication application provides uplink and downlink communication commands. The airborne / ground end uses a "fill-in-the-blank" method, allowing users to input keywords to fill in the statements before they are sent to the ground / airborne end. It contains nearly 600 uplink and downlink commands, including various information requests such as route changes and permission, lateral deviations, speed allocation, radio frequency allocation, and communication management. It also provides the crew with a variety of services such as in-flight response information, permission requests, report information, and detailed emergency information.

[0031] S11. The aircraft initiates a login request to the onboard terminal via the CM application; S12. After receiving the request, the user management module receives and parses the key parameters and supported application types, and forwards the key parameters and supported application types to the ground terminal for review. S13. The ground terminal determines whether to allow access based on the policy. If it refuses, it returns a rejection reason code and terminates the session. If it accepts, it updates the status of the aircraft in the system to "logged in" and proceeds to S14. S14. Generate the corresponding connection identifier, complete the aircraft's registration in the ground system, and complete identity authentication and service authorization.

[0032] S2. After authorization is completed, the system will authorize the ADS-C application and the CPDLC application. If the ADS-C application is started, proceed to S3; if the CPDLC application is started, proceed to S5. With its rich instruction set and four types of contracts, ADS-C applications can achieve the functions of sensing, reporting, and monitoring four-dimensional track data. Depending on the contract type and priority, it can provide one-time or periodic contract reports and supports track-based run (TBO) mode. CPDLC contains approximately 600 uplink and downlink commands, comprehensively covering basic air-to-ground communication content, and also includes free text transmission functionality, offering simplicity and flexibility. Furthermore, it automatically generates child window interfaces based on backend ASN.1 data types and nested logic, greatly enhancing the application's scalability.

[0033] S21. After the airborne terminal login is completed, the system automatically authorizes the ADS-C application and the CPDLC application. The initial state of both the ADS-C application and the CPDLC application is "not started". S22. The user management module maintains the application connection status of each logged-in aircraft through a state mechanism. S23. The bottom controller initiates "establish contact" and "start service" commands to the ADS-C application and CPDLC application through the CM application, and activates the corresponding application as needed. If the ADS-C application is started, proceed to S3; if the CPDLC application is started, proceed to S5.

[0034] After S3, identity authentication, and service authorization are completed, a contract will be signed according to the requirements. S31. After starting the ADS-C application, establish a contract request based on the key parameters in S1. S32. Traverse all contracts in the contract library. If a contract with the same ID exists, create a timer as required and proceed to S35; otherwise, proceed to S33. S33. Check the number of contracts in the contract library. If the number of contracts has reached 256, reject the access of new contracts and send a reminder to the interface operation module; otherwise, create a new contract node. S34. Create timers on demand in the new contract node, and increment the contract quantity counter by 1 at the same time; S35. Enter the contract management module.

[0035] S4. After signing the contract, enter the contract management module, and the system will work according to the contract model; S41. After receiving the contract information, the contract management module determines the flight status. If the flight is in an emergency, it determines the contract type and returns an error message. The flight remains in an emergency and sends an emergency notification to the ground terminal. Otherwise, proceed to S42. Emergency contracts have the highest priority, while the other three types of contracts have the same priority. The system will overwrite the old contracts with the new ones based on the contract signing time and order, from most recent to oldest.

[0036] S42. Pilots process contracts according to three different types: cycle, event, and demand, and receive different contract reports. Once the periodic contract request is confirmed by the ground control and the periodic contract is signed, the flight will automatically transmit the required status parameters via sensors. The new periodic contract will replace the old contract in sending reports, distinguished by a contract ID. When the airborne terminal enters the periodic report processing module, the system will generate a timer based on the period set in the uplink contract. The timer module determines the report transmission time based on the reporting rate requested in the contract. In addition, the ground controller can select the parameter type and modulus in the uplink request, and the airborne terminal will send a message containing the parameters based on this information. The modulus n refers to the interval after which a specified parameter is sent every n messages. This method optimizes the frequency of monitoring data transmission, enables on-demand information updates, ensures no critical information is missed, and improves system resource allocation capabilities. Periodic contracts require aircraft in flight to periodically report certain flight-related data according to specified reporting cycles and modules. This information mainly includes predicted route information (such as waypoint locations and estimated arrival times), ground vector information (including ground speed and heading), air vector information (such as airspeed and vertical speed), estimated arrival time ranges, meteorological information (such as wind direction, wind speed, and turbulence conditions), and speed plan information (covering preset speed values ​​for each flight phase, such as climb, cruise, and descent).

[0037] The processing method for demand reports is exactly the same as that for periodic reports sent in a single module; both assemble and send downlink reports based on the elements requested by the controller. The main difference lies in the sending mechanism: periodic contracts require a timer to repeatedly send reports at set intervals, while demand contracts do not require a timer and only send one report after establishment. The types of information requested by demand contracts and periodic contracts are the same, which can include elements such as predicted flight paths, ground vectors, air vectors, arrival times, weather, and speed plans. The difference is that demand contracts directly request data, do not set modules, and are destroyed after the aircraft returns a report.

[0038] The establishment of event contracts and the sending of reports are based on thresholds and trigger points set by the ground control in the request. Using the aircraft's own sensors, the events in the request are monitored and data compared. When flight conditions exceed the predetermined event range, this serves as a trigger, generating an event report and sending it to the ground control. Ground controllers can use this function to constrain data such as the flight's operating range, speed, and direction. When other events occur, corresponding reports will be sent to the ground control, facilitating timely scheduling by the controller.

[0039] S43. Determine if there is an emergency alert in the contract report. If so, switch the flight status to emergency mode and send an emergency status notification to the ground terminal. Otherwise, send an emergency status notification directly to the ground terminal.

[0040] S5. During operation, data exchange between the airborne and ground ends is carried out through the message management module and the data transceiver module.

[0041] S51. During operation, the ground and airborne terminals continuously generate various messages. S52. The message at one end generates a binary message according to the code framework of the unified encoding and decoding of aviation messages using ASN.1 syntax and UPER encoding, based on the user's selection and event input. S53. The binary message is transmitted to the other end through the data transceiver module, and the other end decodes the message through UPER. S54. Extract the decoded data, extract the key fields and convert them back into structured data, and then output and print the data through ASN.1. S55. Display the printed data through the front end.

[0042] Therefore, this invention adopts the above-mentioned structure to develop and verify the feasibility of an air-to-ground broadband communication system based on the ATN B2 standard for civil aviation broadband communication. It integrates current data transmission network and communication monitoring function design schemes to develop a relatively complete and efficient aviation broadband communication system and corresponding methods.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An ATN B2 application system for broadband communication in civil aviation, characterized in that: It includes a user management module, a contract management module, a message management module, a data sending and receiving module, and a user interface operation module; The user management module is used to implement aircraft identity authentication, connection status management and service authorization functions, and manages the entire process of aircraft login, status maintenance and connection control. The contract management module is used to sign service contracts according to actual needs and to help ground equipment obtain the aircraft's in-flight status. The message management module is responsible for message encapsulation, parsing, and interface display. Message encapsulation and parsing are performed on a single application. Messages generated by the application front-end are used for unified processing of the generation, parsing, storage, status tracking, and logging of various messages in the system. The data transceiver module is used to enable interconnection between ground-based and airborne application equipment; The interface operation module is responsible for dynamically loading or disabling the corresponding application interface based on user requests and system events.

2. The ATN B2 application system for civil aviation broadband communication according to claim 1, characterized in that: The contract management module includes a contract storage unit for storing contract entities. Each contract entity includes a contract ID, contract type, contract request message element, timer modules required for periodic contracts and their corresponding IDs, contract trigger events, and requirement content markers.

3. The ATN B2 application system for civil aviation broadband communication according to claim 2, characterized in that: The message management module includes a message encapsulation module, a message parsing module, a message management module, and a message display module.

4. An ATN B2 application method for civil aviation broadband communication, characterized in that: The ATN B2 application system for civil aviation broadband communication as described in claims 1-3 includes the following steps: S1. The aircraft initiates a login request to the onboard terminal through the CM application and uses the user management module for identity authentication and service authorization. S2. After authorization is completed, the system authorizes the ADS-C application and the CPDLC application. If the ADS-C application is started, proceed to S3; if the CPDLC application is started, proceed to S5. After S3, identity authentication, and service authorization are completed, a contract will be signed according to the requirements. S4. After signing the contract, enter the contract management module, and the system will work according to the contract model; S5. During operation, data exchange between the airborne and ground ends is carried out through the message management module and the data transceiver module.

5. The ATN B2 application method for civil aviation broadband communication according to claim 4, characterized in that, The S1 process includes the following steps: S11. The aircraft initiates a login request to the onboard terminal via the CM application; S12. After receiving the request, the user management module receives and parses the key parameters and supported application types, and forwards the key parameters and supported application types to the ground terminal for review. S13. The ground terminal determines whether to allow access based on the policy. If it refuses, it returns a rejection reason code and terminates the session. If it accepts, it updates the status of the aircraft in the system to "logged in" and proceeds to S14. S14. Generate the corresponding connection identifier, complete the aircraft's registration in the ground system, and complete identity authentication and service authorization.

6. The ATN B2 application method for civil aviation broadband communication according to claim 5, characterized in that, The process of S2 is as follows: S21. After the airborne terminal login is completed, the system automatically authorizes the ADS-C application and the CPDLC application. The initial state of both the ADS-C application and the CPDLC application is "not started". S22. The user management module maintains the application connection status of each logged-in aircraft through a state mechanism. S23. The bottom controller initiates "establish contact" and "start service" commands to the ADS-C application and CPDLC application through the CM application, and activates the corresponding application as needed. If the ADS-C application is started, proceed to S3; if the CPDLC application is started, proceed to S5.

7. The ATN B2 application method for civil aviation broadband communication according to claim 6, characterized in that, The process of S3 is as follows: S31. After starting the ADS-C application, establish a contract request based on the key parameters in S1. S32. Traverse all contracts in the contract library. If a contract with the same ID exists, create a timer as required and proceed to S35; otherwise, proceed to S33. S33. Check the number of contracts in the contract library. If the number of contracts has reached 256, reject the access of new contracts and send a reminder to the interface operation module; otherwise, create a new contract node. S34. Create timers on demand in the new contract node, and increment the contract quantity counter by 1 at the same time; S35. Enter the contract management module.

8. The ATN B2 application method for civil aviation broadband communication according to claim 7, characterized in that, The process of S4 is as follows: S41. After receiving the contract information, the contract management module determines the flight status. If the flight is in an emergency, it determines the contract type and returns an error message. The flight remains in an emergency and sends an emergency notification to the ground terminal. Otherwise, proceed to S42. S42. Pilots process contracts according to three different types: cycle, event, and demand, and receive different contract reports. S43. Determine if there is an emergency alert in the contract report. If so, switch the flight status to emergency mode and send an emergency status notification to the ground terminal. Otherwise, send an emergency status notification directly to the ground terminal.

9. The ATN B2 application method for civil aviation broadband communication according to claim 8, characterized in that, The process of S5 is as follows: S51. During operation, the ground and airborne terminals continuously generate various messages. S52. The message at one end generates a binary message according to the code framework of the unified encoding and decoding of aviation messages using ASN.1 syntax and UPER encoding, based on the user's selection and event input. S53. The binary message is transmitted to the other end through the data transceiver module, and the other end decodes the message through UPER. S54. Extract the decoded data, extract the key fields and convert them back into structured data, and then output and print the data through ASN.

1. S55. Display the printed data through the front end.

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