CN117768000A - Method, spacecraft and system for satellite-to-ground communication based on proxy service - Google Patents

Abstract

The embodiment of the application provides a method, a spacecraft and a system for satellite-to-ground communication based on proxy service, wherein the method comprises the following steps: acquiring position information of a spacecraft to be accessed; acquiring available ground stations according to the position information and the ground station information; sending an access request to the available ground station; receiving a response message from the available ground station; analyzing the response message to obtain an allocated IP address; and completing the operation of accessing the ground station according to the allocated IP address. By adopting the application layer proxy service provided by the embodiment of the application, the tasks are distinguished by uniformly deploying the proxy service on the spacecraft and the ground station, and a safe, reliable and real-time ubiquitous satellite-ground integrated communication network is established.

Description

Method, spacecraft and system for satellite-to-ground communication based on proxy service

Technical Field

The application relates to the field of communication, in particular to a method, a spacecraft and a system for satellite-to-ground communication based on proxy service.

Background

Currently, the ground network generally adopts UDP/IP and TCP/IP protocols, and the spatial network generally uses spatial network communication protocols (for example, CCSDS standard protocols), so that the development process of satellite-ground integrated network communication is hindered by two protocol systems which are independent of each other.

In view of the fact that the ground network infrastructure is generally applied and not easy to replace, and the ground standard internet protocol is relatively mature, related research at home and abroad directly expands and applies the ground existing standard internet protocol to a space network, as shown in fig. 1, each layer of the spacecraft (namely, the spacecraft terminal) in fig. 1 is respectively a LAN local area network layer, an Ethernet layer, an IP layer, a transmission layer adopting TCP or UDP and application layer application, or each layer of the spacecraft (aerospace router) is respectively a LAN local area network layer, an Ethernet layer and an IP layer; the lowest layer of the ground station (i.e., the ground station router) of fig. 1 is a local area network LAN layer, a wide area network WAN layer or an RF layer, the second layer is an HDLC layer or an Ethernet layer, the network layer is an IP layer, or the lowest layer of the ground station (i.e., the ground station terminal) of fig. 1 is a local area network LAN layer, the second layer is an Ethernet layer, the network layer is an IP layer, the transmission layer is a TCP layer or a UDP layer, and the uppermost layer is application layer application. That is, the network layers of the spacecraft and the ground station in fig. 1 uniformly adopt an IP protocol, so that the standard internet router can meet the network routing function of the space base, and the physical layer and the data link layer related to the transmission medium under the IP are transparent to the IP layer, and provide the data messaging function for the IP layer.

In addition to geosynchronous orbit spacecraft, other spacecraft have high dynamics in spatial locations, which results in the communication links of the spacecraft with the single ground station of fig. 1 not being continuously available in time, which is a technical obstacle for data interaction of the ground with the spacecraft. In order to solve this problem, the related art provides a Mobile-IP protocol, which belongs to the category of the IP layer, so that a spacecraft can have a fixed IP address, when the spacecraft passes through a ground station, a broadcast signal of the ground station is received and a link is established, a real internet IP address is obtained, the real IP address is registered and updated with a ground proxy server, when an IP message is sent to the fixed IP of the spacecraft, the ground proxy server automatically forwards the IP message to the real IP address of the spacecraft, thereby completing IP message routing delivery.

The inventor researches find that at least the following defects exist in the adoption of the Mobile-IP protocol: the task communication requirements of different task types and different priorities cannot be distinguished and processed, and the resource utilization rate is low; the Mobile-IP broadcast registration Mobile access mechanism has potential safety hazards; the satellite-ground link condition cannot be self-adapted, and a proper network session mechanism is selected to improve the communication reliability.

Disclosure of Invention

The embodiment of the application aims to provide a method, a spacecraft and a system for satellite-to-ground communication based on proxy service.

In a first aspect, an embodiment of the present application provides a satellite-to-ground communication method based on proxy service, which is applied to proxy service of an application layer of a spacecraft, and the method includes: acquiring position information of a spacecraft to be accessed; acquiring available ground stations according to the position information and the ground station information; sending an access request to the available ground station; receiving a response message from the available ground station; analyzing the response message to obtain an allocated IP address; and completing the operation of accessing the ground station according to the allocated IP address.

In some embodiments, the obtaining the location information of the spacecraft to be accessed includes: reading orbit double rows and GNSS data of a global navigation satellite system; and calculating the height of the spacecraft to be accessed according to the orbit double rows and the GNSS data to obtain the position information.

In some embodiments, the sending an access request to the available ground station includes: transmitting the access request to the available ground station over a radio frequency signal, RF, link; the receiving the response message from the available ground station comprises the following steps: and receiving the response message through the RF link.

In some embodiments, the reply message is generated by the available ground station after confirming that the spacecraft to be accessed is authenticated.

In some embodiments, before the parsing the reply message to obtain the IP address, the method further includes: and confirming that the available ground station is authenticated.

In some embodiments, the operations for accessing the ground station according to the allocated IP address include: binding the distributed IP, the port and the RF link through a data exchange mechanism, so that an IP layer of the spacecraft to be accessed is transparently accessed to a local area network of the available ground station.

In some embodiments, the method further comprises: a step for autonomously deciding a transmission control protocol.

In some embodiments, the step for autonomously deciding a transmission control protocol comprises: requesting to acquire the bit error rate obtained by the available ground station; if the error rate is confirmed to be larger than a set threshold, confirming to select a first transmission control protocol, wherein the first transmission control protocol is UDP/IP protocol; and if the error rate is confirmed to be smaller than the set threshold, confirming to select a second transmission control protocol, wherein the second transmission control protocol is a TCP/IP protocol.

In some embodiments, after the operation of accessing the ground station is completed according to the assigned IP address, the method further comprises: and updating the sending queue according to the task type and sending data according to the updated queue.

In some embodiments, the step for updating the send queue according to the task type and sending data according to the updated queue includes: if the current task is confirmed to be a real-time task, the task priority of the current task is read; updating a real-time task sending queue according to the task priority of the current task to obtain a first queue; and transmitting data to the available ground stations according to the first queue.

In some embodiments, the step for updating the send queue according to the task type and sending data according to the updated queue includes: if the current task is confirmed to be a delay task, storing processing data corresponding to the current task to a local place; creating a timer and a count value corresponding to the current task; if the timer is confirmed to reach the count value, reading task priority; updating a real-time task sending queue according to the task priority of the current task to obtain a second queue; and transmitting data to the available ground stations according to the second queue.

In a second aspect, some embodiments of the present application provide a proxy-based satellite-to-ground communication method, applied to a ground station, the method comprising: receiving an access request from a spacecraft to be accessed; if the verification of the spacecraft to be accessed is confirmed to pass according to the access request, generating a response message for carrying and distributing an IP address for the spacecraft to be accessed; and providing the response message for the spacecraft to be accessed.

In some embodiments, the access request is received and the reply message is sent over an RF link.

In a third aspect, some embodiments of the present application provide a spacecraft, the VSAT proxy service of the spacecraft application layer comprising: the spacecraft to be accessed comprises a spacecraft to be accessed position information acquisition module, a position information acquisition module and a position information acquisition module, wherein the spacecraft to be accessed position information acquisition module is configured to acquire the position information of the spacecraft to be accessed; an available ground station acquisition module configured to acquire an available ground station from the location information and ground station information; an access request transmitting module configured to transmit an access request to the available ground station; a response message receiving module configured to receive a response message from the available ground station; the analysis module is configured to analyze the response message to obtain an allocated IP address; and the access module is configured to finish the operation of accessing the ground station according to the allocated IP address.

In a fourth aspect, some embodiments of the present application provide a communication system comprising a spacecraft according to the third aspect and a ground station, the ground station being configured to: receiving an access request from a spacecraft to be accessed; if the verification of the spacecraft to be accessed is confirmed to pass according to the access request, generating a response message for carrying and distributing an IP address for the spacecraft to be accessed; and providing the response message for the spacecraft to be accessed.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of protocol types employed by layers of a spacecraft and ground station provided in the related art;

FIG. 2 is a block diagram of one of the methods for proxy-based satellite-to-ground communications provided in embodiments of the present application;

fig. 3 is a schematic diagram of protocol types adopted by each layer of a spacecraft and a ground station according to an embodiment of the present application;

FIG. 4 is a second method of proxy-based satellite-to-ground communication provided in an embodiment of the present application;

FIG. 5 is a third exemplary method for proxy-based satellite-to-ground communication according to an embodiment of the present application;

FIG. 6 is a fourth example of a method for proxy-based satellite-to-ground communication provided in an embodiment of the present application;

fig. 7 is a spacecraft provided in an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures. Meanwhile, in the description of the present application, the terms "first", "second", and the like are used only to distinguish the description, and are not to be construed as indicating or implying relative importance.

Referring to fig. 1, fig. 1 is a protocol type adopted by each layer of a spacecraft and a ground station provided by the related art, and protocols adopted by each layer of a spacecraft terminal are respectively: local area network protocol LAN, ethernet protocol, IP protocol, TCP/UDP protocol, application layer Application related protocol; the protocols adopted by each layer of network element equipment such as a spacecraft router or a switch are respectively as follows: LAN/RF link protocol, ethernet/HDLC protocol and IP protocol; the protocols adopted by each layer of the ground station terminal are respectively as follows: local area network protocol LAN, ethernet protocol, IP protocol, TCP/UDP protocol, application layer Application related protocol; protocols adopted by each layer of network element equipment such as a ground station router or a switch are respectively as follows: local area network protocol LAN/RF link protocol/wide area network protocol WAN, ethernet protocol/HDLC protocol, IP protocol. In the figure, the bottommost layer between a spacecraft terminal and network equipment such as a spacecraft router or a switch is communicated by adopting a LAN (local area network) protocol, the router or the switch of the spacecraft and the network equipment such as a ground station router or the switch are communicated by adopting an RF (radio frequency) link, the ground station router or the switch and the ground terminal are communicated with other terminals by adopting a WAN (wide area network) protocol through an IP (Internet protocol) network, and the ground station router or the switch and the ground station terminal are communicated by adopting a LAN (local area network).

That is, the standard internet protocol existing at the surface is directly extended to be applied to the spatial network in fig. 1: the network layer uniformly adopts an IP protocol, and a standard Internet router can meet the network routing function of the space base; and the physical layer and the data link layer which are related to the transmission medium under the IP are transparent to the IP layer, and provide the data messaging function for the IP layer.

As noted in the background section, with the architecture of fig. 1, when a spacecraft crosses an ambient ground station, a broadcast signal from the ground station is received and a link is established, it being understood that this broadcast registration mobile access mechanism presents a security risk. In addition, the network architecture of fig. 1 cannot adapt to satellite-ground link conditions, select a suitable network session mechanism, and cannot distinguish task communication requirements for processing different task types and different priorities.

To address at least the above technical problems, some embodiments of the present application provide a method of accessing a ground station.

As shown in fig. 2, an embodiment of the present application provides a satellite-to-ground communication method based on proxy service, which is applied to proxy service of a spacecraft application layer, and the method includes: s101, acquiring position information of a spacecraft to be accessed; s102, acquiring available ground stations according to the position information and the ground station information; s103, sending an access request to the available ground station; s104, receiving a response message from the available ground station; s105, analyzing the response message to obtain an allocated IP address; s106, completing the operation of accessing the ground station according to the allocated IP address.

It should be noted that, the protocol types of each layer operated by the method for accessing the ground station in fig. 2 are shown in fig. 3, unlike fig. 1, in the application layer in fig. 3, proxy services are set (that is, the embodiment of the present application proposes proxy services located in the application layer), and in the embodiment of the present application, by uniformly deploying proxy services in the spacecraft and the ground station, tasks are distinguished, and a safe, reliable and real-time ubiquitous satellite-ground integrated communication network is established.

The relevant steps of fig. 2 are exemplarily set forth below.

In some embodiments of the present application, S101 illustratively includes: reading orbit double rows and GNSS data of a global navigation satellite system; and calculating the height of the spacecraft to be accessed according to the orbit double rows and the GNSS data to obtain the position information.

In some embodiments of the present application, S103 illustratively includes: transmitting the access request to the available ground station over a radio frequency signal, RF, link; the receiving the response message from the available ground station comprises the following steps: and receiving the response message through the RF link.

In some embodiments of the present application, the reply message is generated by the available ground station after confirming that the spacecraft to be accessed is authenticated.

In some embodiments of the present application, before the parsing the reply packet to obtain the IP address, the method further includes: and confirming that the available ground station is authenticated.

In some embodiments of the present application, S106 illustratively includes: binding the distributed IP, the port and the RF link through a data exchange mechanism, so that an IP layer of the spacecraft to be accessed is transparently accessed to a local area network of the available ground station.

That is, some embodiments of the present application provide a new mobile access policy for accessing a spacecraft into a ground station, corresponding to S101-S106 described above, which includes:

firstly, a spacecraft reads track double-row and GNSS data according to track double-row information.

In a second step, the spacecraft calculates the position altitude, i.e. the position altitude is calculated from the orbital double rows and the GNSS data.

Thirdly, the spacecraft calculates available private ground stations according to the ground station information.

It should be noted that, the information of the double track and the ground station in the above steps is the operation configuration parameter of the spacecraft, and can be updated on track. The third step of calculation may be performed with a private ground station: refers to matching ground stations (closest ordered by distance by default) in signal coverage with the spacecraft from a private ground station information list according to the real-time position altitude of the spacecraft.

Fourth, the spacecraft requests access to available private ground stations via the RF link.

In some embodiments of the present application, the spacecraft is provided with at least 1 Local Area Network (LAN) device, which may be one or more network devices or computers, 1 RF communicator, as shown in fig. 3; real-time data interaction is established between a spacecraft Local Area Network (LAN) and an RF communication machine (one implementation way is that a transmitting end packages a standard IP message of the LAN as effective data bytes into data frames according to an RF communication protocol, a receiving end de-frames the data frames according to the communication protocol to obtain the IP message and forwards the IP message to a gateway IP and a port of the LAN in real time, and a store-and-forward mechanism can be adopted for communication tasks with low real-time requirements), so that a binding relation is established between the spacecraft LAN and the RF communication link.

Fifth, the ground station receives the request over the RF link.

And sixthly, the ground station judges whether the verification is passed or not, if so, the organization agrees with the message (i.e. agrees to access the ground station) and distributes the dynamic IP to obtain a response message, and if not, the organization refuses the message to obtain the response message.

Seventh, the ground station sends a response message to the spacecraft through the RF link.

Eighth, the spacecraft receives the ground station reply (i.e., reply message) over the RF link.

And ninth, determining that the verification is passed.

And tenth, analyzing the response message to obtain the distributed dynamic IP address.

Eleventh, create virtual WAN (binding RF), set IP to assign dynamic IP to ground station.

It is to be understood that after the Local Area Network (LAN) of the spacecraft sets the IP address automatically allocated by the ground station, the binding relationship between the IP, the port and the RF is established through the data exchange mechanism, so that the spacecraft realizes transparent access to the ground station LAN by the IP layer, and can perform data interaction with the external network through the ground station.

It should be noted that, in some embodiments of the present application, the autonomous decision flow of the spacecraft transmission control protocol is implemented through the set VSTA proxy service. That is, in some embodiments of the present application, the method further comprises: a step for autonomously deciding a transmission control protocol.

For example, in some embodiments of the present application, the step for autonomously deciding a transmission control protocol includes: requesting to acquire the bit error rate obtained by the available ground station; if the error rate is confirmed to be larger than a set threshold, confirming to select a first transmission control protocol, wherein the first transmission control protocol is UDP/IP protocol; and if the error rate is confirmed to be smaller than the set threshold, confirming to select a second transmission control protocol, wherein the second transmission control protocol is a TCP/IP protocol.

As shown in fig. 5, the steps for autonomously deciding a transmission control protocol include:

first, the ground station error rate is requested based on UDP.

And step two, receiving the bit error rate response information of the ground station.

And thirdly, judging whether the error rate is larger than a threshold value, if so, selecting a UDP/IP protocol, and if not, selecting the TCP/IP protocol.

The ground station error rate is real-time statistical information of the ground station and reflects satellite-ground link condition changes caused by weather changes and the like. The threshold value is a spacecraft operation configuration parameter and can be updated on orbit.

It should be noted that, for the real-time requirement of the communication task, some embodiments of the present application divide the task types into two types of real-time tasks and delay tasks through proxy services, and for the delay tasks, the proxy services support users to specify the data delay sending time. That is, in some embodiments of the present application, after the operation of accessing the ground station according to the assigned IP address is completed, the method further includes: and updating the sending queue according to the task type and sending data according to the updated queue.

In some embodiments of the present application, the step for updating the send queue according to the task type and sending data according to the updated queue includes: if the current task is confirmed to be a real-time task, the task priority of the current task is read; updating a real-time task sending queue according to the task priority of the current task to obtain a first queue; and transmitting data to the available ground stations according to the first queue.

In some embodiments of the present application, the step for updating the send queue according to the task type and sending data according to the updated queue includes: if the current task is confirmed to be a delay task, storing processing data corresponding to the current task to a local place; creating a timer and a count value corresponding to the current task; if the timer is confirmed to reach the count value, reading task priority; updating a real-time task sending queue according to the task priority of the current task to obtain a second queue; and transmitting data to the available ground stations according to the second queue.

As shown in fig. 6, the method for accessing the ground station provided in some embodiments of the present application further includes a policy for classifying tasks, specifically including:

first, data is received.

And secondly, analyzing data.

Thirdly, judging whether the task type belongs to a time delay task or a real-time task, and if the task type belongs to the time delay task, executing the fourth to eighth steps; if the task is real-time, the ninth step and the tenth step are executed.

Fourth, the data is stored locally.

Fifth, create a timer.

And sixthly, determining that the timing time reaches a set threshold.

And seventh, reading the task priority.

And eighth step, updating the transmission queue and continuing to execute the eleventh step.

And ninth, reading task priority.

Tenth, the transmit queue is updated.

Eleventh, data is sent.

It should be noted that, some embodiments of the present application are directed to the same type of communication task, where the proxy service is classified into four levels of high, medium, normal and low according to the importance degree of the task, and orders the data entering the transmission queue according to the task priority, and updates the transmission queue. The update processing rule of the queue is: the priority is higher than the preceding, the priority is ordered according to the time of entering the queue, and the priority is the preceding of entering the queue.

It will be appreciated that some embodiments of the present application have at least the following technical advantages: first, the network architecture of the embodiment of the application has good toughness. The network layer uniformly adopts an IP protocol, any route or spacecraft serving as a router is failed or damaged, and the routing of the IP message to a destination in a data driving mode is not affected. Second, the network of the embodiment of the application has good real-time performance. By deploying proxy service, the task types and the task priorities are distinguished, spacecraft networks and storage resources are reasonably utilized, various task demands are met to the greatest extent, and low-delay requirements of high-priority real-time tasks are further guaranteed. Third, the network security of the embodiment of the application is high. The mobile access ground station is realized through proxy service, a broadcasting registration mechanism is not adopted, the spacecraft calculates the available private ground station according to the track position height, and the connection with the ground station is actively requested, so that the safety aspect is ensured. Fourth, the reliability of the network of the embodiment of the application is high. Through proxy service, the spacecraft can autonomously select a transmission control protocol according to real-time bit error rate statistical information of the ground station, so that the method is suitable for the condition of a space-earth link caused by environmental change and improves transmission efficiency.

Some embodiments of the present application provide a proxy service-based satellite-to-ground communication method, applied to a ground station, the method comprising: receiving an access request from a spacecraft to be accessed; if the verification of the spacecraft to be accessed is confirmed to pass according to the access request, generating a response message for carrying and distributing an IP address for the spacecraft to be accessed; and providing the response message for the spacecraft to be accessed. In some embodiments of the present application, the access request is received and the reply message is sent over an RF link.

In order to avoid repetition of the method for accessing the ground station to the application ground station, the description of the related technical scheme may be referred to in detail.

It will be appreciated that some embodiments of the present application are directed to network communication protocols: instead of adopting the traditional CCSDS space network protocol, the proxy service is deployed in an application layer, and the network layer uniformly adopts a standard IP protocol to construct an heaven-earth integrated network, so that reasonable utilization of network resources according to task types and priorities is supported; selecting a transmission control protocol from the applicable link conditions; secure mobile access and seamless handover. According to the method and the device, the proxy service is adopted to distinguish task types and task priorities in terms of resource utilization, the network and storage resources are reasonably configured for different tasks, the resource utilization rate is improved, the communication requirements of different types of tasks are met, and the low-delay requirements of high-priority real-time tasks are guaranteed. Some embodiments of the present application are secure: instead of using Mobile-IP broadcast registration mechanism, proxy service uses predictive request access mechanism: by predicting the position and the height of the spacecraft, the available private ground station is calculated, and the active request is connected with the ground station, so that Mobile access is realized, and meanwhile, the safety problem caused by a Mobile-IP broadcast registration mechanism is avoided.

As shown in fig. 7, some embodiments of the present application provide a spacecraft, where a proxy service of an application layer of the spacecraft includes: the spacecraft to be accessed position information acquisition module 101 is configured to acquire position information of the spacecraft to be accessed; an available ground station acquisition module 102 configured to acquire available ground stations based on the location information and ground station information; an access request sending module 103 configured to send an access request to the available ground station; a reply message receiving module 104 configured to receive a reply message from the available ground station; the parsing module 105 is configured to parse the response message to obtain an allocated IP address; an access module 106 configured to perform access to the ground station according to the assigned IP address.

It should be noted that, for the implementation process of each module in fig. 7, reference may be made to the foregoing description of the method portion, and redundant description is not repeated here.

Some embodiments of the present application provide a communication system comprising a spacecraft as described in the above embodiments and a ground station, and the ground station is configured to: receiving an access request from a spacecraft to be accessed; if the verification of the spacecraft to be accessed is confirmed to pass according to the access request, generating a response message for carrying and distributing an IP address for the spacecraft to be accessed; and providing the response message for the spacecraft to be accessed.

In the several embodiments provided in this application, it should be understood that the disclosed apparatus and method may be implemented in other manners as well. The apparatus embodiments described above are merely illustrative, for example, flow diagrams and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

In addition, the functional modules in the embodiments of the present application may be integrated together to form a single part, or each module may exist alone, or two or more modules may be integrated to form a single part.

The functions, if implemented in the form of software functional modules and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

The foregoing is merely exemplary embodiments of the present application and is not intended to limit the scope of the present application, and various modifications and variations may be suggested to one skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

Claims (10)

1. A method of satellite-to-ground communication based on proxy services, applied to proxy services of a spacecraft application layer, the method comprising:

acquiring position information of a spacecraft to be accessed;

acquiring available ground stations according to the position information and the ground station information;

sending an access request to the available ground station;

receiving a response message from the available ground station;

analyzing the response message to obtain an allocated IP address;

and completing the operation of accessing the ground station according to the allocated IP address.

2. The method of claim 1, wherein the obtaining location information of the spacecraft to be accessed comprises:

reading orbit double rows and GNSS data of a global navigation satellite system;

and calculating the height of the spacecraft to be accessed according to the orbit double rows and the GNSS data to obtain the position information.

3. The method of claim 1, wherein,

the sending an access request to the available ground station includes: transmitting the access request to the available ground station over a radio frequency signal, RF, link;

the receiving the response message from the available ground station comprises the following steps: and receiving the response message through the RF link, wherein the response message is generated by the available ground station after confirming that the spacecraft to be accessed passes verification.

4. The method of claim 3, wherein prior to said parsing said reply message to obtain an IP address, said method further comprises: and confirming that the available ground station is authenticated.

5. The method of claim 4, wherein said performing access to the ground station based on said assigned IP address comprises:

binding the distributed IP, the port and the RF link through a data exchange mechanism, so that an IP layer of the spacecraft to be accessed is transparently accessed to a local area network of the available ground station.

6. The method of claim 5, wherein the method further comprises:

requesting to acquire the bit error rate obtained by the available ground station;

if the error rate is confirmed to be larger than a set threshold, confirming to select a first transmission control protocol, wherein the first transmission control protocol is UDP/IP protocol;

and if the error rate is confirmed to be smaller than the set threshold, confirming to select a second transmission control protocol, wherein the second transmission control protocol is a TCP/IP protocol.

7. The method of claim 6, wherein after the operation of accessing the ground station is completed according to the assigned IP address, the method further comprises: and updating the sending queue according to the task type and sending data according to the updated queue by the spacecraft.

8. The method of claim 7, wherein the step for the spacecraft to update the transmit queue according to the task type and transmit data according to the updated queue comprises:

if the current task is confirmed to be a real-time task, the task priority of the current task is read;

updating a real-time task sending queue according to the task priority of the current task to obtain a first queue;

transmitting data to the available ground station according to the first queue;

or,

if the current task is confirmed to be a delay task, storing processing data corresponding to the current task to a local place;

creating a timer and a count value corresponding to the current task;

if the timer is confirmed to reach the count value, reading task priority;

updating a real-time task sending queue according to the task priority of the current task to obtain a second queue;

and transmitting data to the available ground stations according to the second queue.

9. A spacecraft, characterized in that it comprises:

the spacecraft to be accessed comprises a spacecraft to be accessed position information acquisition module, a position information acquisition module and a position information acquisition module, wherein the spacecraft to be accessed position information acquisition module is configured to acquire the position information of the spacecraft to be accessed;

an available ground station acquisition module configured to acquire an available ground station from the location information and ground station information;

an access request transmitting module configured to transmit an access request to the available ground station;

a response message receiving module configured to receive a response message from the available ground station;

the analysis module is configured to analyze the response message to obtain an allocated IP address;

and the access module is configured to finish the operation of accessing the ground station according to the allocated IP address.

10. A communication system comprising the spacecraft of claim 14 and a ground station, and wherein the ground station is configured to: receiving an access request from a spacecraft to be accessed; if the verification of the spacecraft to be accessed is confirmed to pass according to the access request, generating a response message for carrying and distributing an IP address for the spacecraft to be accessed; and providing the response message for the spacecraft to be accessed.