Satellite internet communication method based on multistage identification separation mapping system

Abstract

The invention relates to a satellite internet communication method based on a multistage identification separation mapping system, and belongs to the technical field of satellite communication. According to the invention, through the design of centralized user routing and terminal identification mapping, distributed terminal identification and satellite identification mapping, inter-satellite rapid exchange based on satellite and terminal identification and the like, a satellite-ground integrated efficient routing exchange system of the satellite internet is realized; the problems of large protocol overhead, slow mapping synchronization, long communication time delay and the like when a traditional identifier separation mapping protocol is applied to a satellite network are solved. The method can be applied to satellite internet scenes of on-satellite routing exchange, inter-satellite link interconnection and user end-to-end intercommunication, occupation of satellite-ground link resources by identification mapping protocol signaling interaction can be effectively reduced, and meanwhile the purpose that communication is rapidly recovered after cross-satellite cross-beam switching of users is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of satellite communication, and particularly to a satellite Internet communication method based on a multi-level identifier separation mapping system. Background Art

[0002] As a new infrastructure for the space-ground integrated network, the current mainstream networking scheme for satellite Internet still adopts the traditional Internet TCP / IP protocol. Such a design will inevitably face the problems of scalability and mobility brought by the ambiguity of IP addresses. The identifier switching network can well solve the problem of IP address ambiguity by using the idea of separating identity from location. In order to introduce the identifier switching idea into the satellite Internet and make it compatible with the IP network, the satellite terminal uses the user IP address as the identity information and the satellite IP address as the location information. After completing the identifier mapping replacement or encapsulation, the satellite node uses the satellite IP address for inter-satellite forwarding. Such a design based on identifier switching can enable the satellite Internet to separate the identity and location information, and improve the routing scalability and terminal mobility of the satellite network.

[0003] In the satellite Internet based on identifier switching, the mapping agent of the satellite terminal sends a registration request to the mapping server on the satellite. The mapping server updates the mapping relationship and sends this update message to the mapping servers of other satellites to keep the mapping servers of each satellite synchronized. The mapping server on the satellite uses the broadcast characteristic of the satellite to broadcast the update to the mapping agents of each satellite terminal. In the environment where the number of satellite Internet users grows rapidly and the terminals frequently switch across satellites, the storage and maintenance of mapping information face huge pressure, seriously affecting the stable operation of the entire satellite Internet. Summary of the Invention

[0004] In view of this, the present invention proposes a satellite Internet communication method based on a multi-level identifier separation mapping system. The present invention extends the single identifier mapping between the user IP and the satellite IP in the traditional satellite identifier switching network to a multi-level identifier mapping between the user route and the terminal identifier, and between the terminal identifier and the satellite identifier, reducing the signaling overhead between the satellite and the ground caused by the update of the identifier mapping, and solving the problem of rapid recovery of communication when the satellite terminal switches across satellites.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows: A satellite Internet communication method based on a multi-level identifier separation mapping system, the multi-level identifier separation mapping system includes a user mapping server, a satellite mapping server, and a user mapping agent. The user mapping server is deployed at a ground gateway station, the satellite mapping server is deployed at a satellite node, and the user mapping agent is deployed at a satellite terminal; a user mapping service is implemented through a centralized mapping mechanism to maintain the mapping relationship between user routes and terminal identifiers; a satellite mapping service is implemented through a distributed mapping mechanism to maintain the mapping relationship between terminal identifiers and satellite identifiers.

[0006] Further, the method includes the following steps: A. The satellite mapping server runs the IS-IS routing protocol, sets the satellite ID as the IP address of the LoopBack interface. After routing convergence, an inter-satellite forwarding table indexed by satellite identifiers is generated; B. The user mapping server periodically broadcasts a location information message through the ground gateway station, including the satellite identifier, terminal identifier, and its own IP address where it is located; after receiving the location information message, the satellite mapping server generates a satellite-ground forwarding table indexed by the terminal identifier and diffuses it to all satellite terminals through the satellite node; after receiving the location information message, the user mapping agent obtains the location information of the user mapping server; C. The user mapping agent runs the RIP routing protocol to obtain reachable routing information on the user side; the user mapping agent generates a user mapping information registration message including the user route and terminal identifier, encapsulates the satellite identifier, terminal identifier, and IP address of the user mapping server, and sends it to the current satellite node; the current satellite node looks up the inter-satellite forwarding table according to the satellite identifier in the user mapping information registration message and forwards it to the satellite node where the ground gateway station is located; the satellite node where the ground gateway station is located looks up the satellite-ground forwarding table according to the terminal identifier in the user mapping information registration message and forwards it to the ground gateway station; after receiving the user mapping information registration message, the user mapping server of the ground gateway station generates a user identifier mapping table; D. After the satellite terminal accesses the network, the satellite mapping server of the current satellite node obtains the terminal identifier information of the satellite terminal, generates a satellite-ground forwarding table indexed by the terminal identifier, and diffuses the newly accessed terminal identifier to other satellite nodes through the link state update message of IS-IS; after receiving the link state update message of IS-IS, other satellite nodes generate a satellite identifier mapping table; E. Route and address the IP data packets between satellite terminals in the following way: after receiving an IP data packet from the user side, the source satellite terminal looks up the user identification mapping table according to the destination IP address to obtain the terminal identification information of the destination satellite terminal; the source satellite terminal encapsulates the terminal identification of the destination satellite terminal in the IP data packet and sends it to the satellite node; the satellite node looks up the satellite identification mapping table according to the terminal identification to obtain the satellite identification of the destination satellite terminal. If it is the same as the local satellite, it looks up the satellite-ground transfer table and forwards the IP data packet from the user link interface to the destination satellite terminal; otherwise, the satellite node encapsulates the satellite identification of the destination satellite terminal in the IP data packet and looks up the inter-satellite transfer table according to the satellite identification, and forwards it hop by hop to the satellite node where the destination satellite terminal is located; the satellite node of the destination satellite terminal looks up the satellite-ground transfer table according to the terminal identification and forwards the IP data packet from the user link interface to the destination satellite terminal; after receiving the IP data packet from the user link, the destination satellite terminal judges the terminal identification in the IP data packet. If it is the same as the local satellite terminal, it forwards the IP data packet to the service terminal; otherwise, it discards the IP data packet.

[0007] Further, in step A, the inter-satellite transfer table includes information such as satellite identification, forwarding port, and next-hop satellite identification.

[0008] Further, in step B, after receiving the location information message from the feeder link, the satellite mapping server forwards it to all user links and inter-satellite links.

[0009] Further, in step B, after receiving the location information message from the inter-satellite link, the satellite mapping server looks up the inter-satellite transfer table according to the satellite identification. If the exit of the inter-satellite transfer table entry is the same as the message receiving interface, it forwards it to all inter-satellite interfaces and satellite-ground interfaces except the receiving interface, otherwise it discards the message.

[0010] Further, in step C, the user identification mapping table includes information such as user route and terminal identification.

[0011] Further, in step D, the satellite identification mapping table includes information such as terminal identification and satellite identification.

[0012] Further, in step E, the satellite terminal looks up the user identification mapping table according to the destination IP address of the IP data packet. If there is no corresponding table entry, it sends a user mapping information query message to the user mapping server to obtain the user identification mapping information. The present invention has the following beneficial effects compared with the background technology: 1. The present invention can decouple the user identification mapping from the satellite identification. After the satellite terminal switches across satellites, there is no need to update the mapping relationship, reducing the occupancy of the satellite-ground link by the identification mapping signaling interaction.

[0013] 2. The present invention can unify satellite identification mapping and inter-satellite routing, use IS-IS routing to achieve rapid diffusion of satellite identification mapping information, and reduce the service recovery time for satellite terminals to switch across satellites.

[0014] In summary, by dividing the original single IP address space of the satellite Internet into three identification spaces: user routing, terminal identification, and satellite identification, and completing addressing and routing selection through identification mapping between different identification spaces, the present invention realizes efficient and flexible networking applications for the satellite Internet, and solves problems such as large satellite-ground protocol overhead and slow convergence of cross-satellite handover caused by large-scale and highly dynamic user networking. Brief Description of the Drawings

[0015] Figure 1 It is a schematic diagram of the application scenario of the present invention. Detailed Embodiment

[0016] The present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

[0017] A satellite Internet communication method based on a multi-level identification separation mapping system Figure 1 As shown in the application scenario of the satellite Internet, this method is implemented by using a multi-layer identification mapping system with user routing and terminal identification, and terminal identification and satellite identification. This system can be specifically divided into three parts: user mapping server, satellite mapping server, and user mapping agent. This method includes the following steps: A. The satellite mapping server runs the IS-IS routing protocol, sets the satellite ID as the IP address of the LoopBack interface, and after routing convergence, generates an inter-satellite forwarding table indexed by the satellite identification.

[0018] In step A, the inter-satellite forwarding table includes information such as satellite identification, forwarding port, and next-hop satellite identification.

[0019] B. The user mapping server periodically broadcasts a location information message through the ground gateway station, including the satellite identification, terminal identification, and its own IP address where it is located. After receiving this message, the satellite mapping server generates a satellite-ground forwarding table indexed by the terminal identification and diffuses it to all satellite terminals through satellite nodes. After receiving this message, the user mapping agent obtains the location information of the user mapping server.

[0020] In step B, after receiving the location information message from the feeder link, the satellite mapping server forwards it to all user links and inter-satellite links. After receiving the location information message from the inter-satellite link, the satellite mapping server looks up the inter-satellite forwarding table according to the satellite identification. If the exit of the inter-satellite forwarding table entry is the same as the message receiving interface, it forwards the message to all inter-satellite interfaces and satellite-ground interfaces except the receiving interface, otherwise it discards the message.

[0021] C. The user mapping agent runs the RIP routing protocol to obtain reachable routing information on the user side. The user mapping agent generates a user mapping information registration message including user routes and terminal identifiers, encapsulates information such as the satellite identifier, terminal identifier, and IP address of the user mapping server, and sends it to the current satellite node. The current satellite node looks up the inter-satellite forwarding table based on the satellite identifier in the user mapping information message and forwards it to the satellite node belonging to the ground gateway station. The satellite node belonging to the ground gateway station looks up the satellite-ground forwarding table based on the terminal identifier in the user mapping information message and forwards it to the ground gateway station. After receiving the user mapping information registration message, the user mapping server of the ground gateway station generates a user identifier mapping table.

[0022] In step C, the user mapping table includes information such as user routes and terminal identifiers.

[0023] D. After the satellite terminal accesses the network, the satellite mapping server of the current satellite node obtains information such as the terminal identifier of the satellite terminal, generates a satellite-ground forwarding table indexed by the terminal identifier, and diffuses the newly accessed terminal identifier to other satellite nodes through the link state update message of IS-IS. After receiving the link state update message of IS-IS, other satellite nodes generate a satellite identifier mapping table.

[0024] In step D, the satellite mapping table includes information such as terminal identifiers and satellite identifiers.

[0025] E. The IP data packet routing and addressing process between satellite terminals is as follows: After the source satellite terminal receives an IP data packet from the user side, it looks up the user identifier mapping table according to the destination IP address to obtain the terminal identifier information of the destination satellite terminal. The source satellite terminal encapsulates the terminal identifier of the destination satellite terminal in the IP data packet and sends it to the satellite node. The satellite node looks up the satellite identifier mapping table according to the terminal identifier, obtains the satellite identifier of the destination satellite terminal. If it is the same as the local satellite, it looks up the satellite-ground forwarding table and forwards the IP data packet from the user link interface to the destination satellite terminal; otherwise, the satellite node encapsulates the satellite identifier of the destination satellite terminal in the IP data packet and looks up the inter-satellite forwarding table according to the satellite identifier, and forwards it hop by hop to the satellite node where the destination satellite terminal is located. The satellite node of the destination satellite terminal looks up the satellite-ground forwarding table according to the terminal identifier and forwards the IP data packet from the user link interface to the destination satellite terminal. After the destination satellite terminal receives the IP data packet from the user link, it judges the terminal identifier in the IP data packet. If it is the same as the local satellite terminal, it forwards the IP data packet to the service terminal; otherwise, it discards the IP data packet.

[0026] In step E, the satellite terminal looks up the user identifier mapping table according to the destination IP address of the IP data packet. If there is no corresponding table entry, it sends a user mapping information query message to the user mapping server to obtain the user mapping information.

[0027] Through designs such as centralized user routing and terminal identifier mapping, distributed terminal identifier and satellite identifier mapping, and satellite - to - satellite fast switching based on satellite + terminal identifiers, the present invention realizes an efficient space - to - ground integrated routing and switching system for satellite Internet, and solves problems existing in the application of traditional identifier - separated mapping protocols to satellite networks, such as large protocol overhead, slow mapping synchronization, and long communication delay. The present invention can be applied to satellite Internet scenarios such as on - satellite routing and switching, satellite - to - satellite link interconnection, and user end - to - end intercommunication, and can effectively reduce the occupation of space - to - ground link resources by identifier mapping protocol signaling interaction, and at the same time achieve the purpose of quickly restoring communication after users cross - satellite and cross - beam switching.

[0028] In summary, the present invention uniquely creates a satellite Internet communication method based on a multi - level identifier - separated mapping system, which can be applied to satellite Internet scenarios such as on - satellite routing and switching, satellite - to - satellite link interconnection, and user end - to - end intercommunication. It can effectively reduce the occupation of space - to - ground link resources by identifier mapping protocol signaling interaction, and at the same time achieve the purpose of quickly restoring communication after users cross - satellite and cross - beam switching.

[0029] Finally, it should be noted that the above - mentioned are only preferred examples of the present invention. Although the present invention has been described in detail with reference to the above - mentioned embodiments, for those skilled in the art, they can still modify the technical solutions of the foregoing embodiments, or perform equivalent replacements for other technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A satellite Internet communication method based on a multi-level identification separation mapping system, wherein the multi-level identification separation mapping system comprises a user mapping server, a satellite mapping server, and a user mapping agent, wherein the user mapping server is deployed at a ground gateway, the satellite mapping server is deployed at a satellite node, and the user mapping agent is deployed at a satellite terminal; characterized in that: The user mapping service is implemented through a centralized mapping mechanism to maintain the mapping relationship between the user route and the terminal identifier; the satellite mapping service is implemented through a distributed mapping mechanism to maintain the mapping relationship between the terminal identifier and the satellite identifier.

2. A satellite Internet communication method based on a multi-level identification separation mapping system according to claim 1, characterized in that: The following steps are involved: A. The satellite mapping server runs the IS-IS routing protocol and sets the satellite ID to the IP address of the LoopBack interface. After the routing converges, it generates an inter-satellite forwarding table indexed by the satellite ID. B. The user mapping server periodically broadcasts location information messages through the ground gateway, including the satellite ID, terminal ID and its own IP address; After receiving the location information message, the satellite mapping server generates a satellite-to-ground forwarding table with the terminal identifier as the index, and spreads it to all satellite terminals through satellite nodes; After receiving the location information message, the user mapping agent obtains the location information of the user mapping server; C. The user mapping agent runs the RIP routing protocol to obtain the reachable routing information on the user side; the user mapping agent generates a user mapping information registration message including the user route and terminal identifier, encapsulates the satellite identifier, terminal identifier, and IP address of the user mapping server, and sends it to the current satellite node; The current satellite node searches the inter-satellite forwarding table according to the satellite ID in the user mapping information registration message and forwards it to the satellite node to which the ground gateway station belongs; The satellite node to which the ground gateway belongs searches the satellite-to-ground forwarding table according to the terminal identifier in the user mapping information registration message and forwards it to the ground gateway; After receiving the user mapping information registration message, the user mapping server of the ground gateway generates a user identification mapping table; D. After the satellite terminal joins the network, the satellite mapping server of the current satellite node obtains the terminal identification information of the satellite terminal, generates a satellite-to-ground forwarding table with the terminal identification as the index, and spreads the newly joined terminal identification to other satellite nodes through the IS-IS link state update message; After receiving the link state update message from IS-IS, other satellite nodes generate a satellite identification mapping table; E. Routing addressing of IP data packets between satellite terminals is performed in the following manner: after receiving the IP data packet from the user side, the source satellite terminal searches the user identification mapping table according to the destination IP address to obtain the terminal identification information of the destination satellite terminal; The source satellite terminal encapsulates the terminal identification of the destination satellite terminal in the IP data packet and sends it to the satellite node; The satellite node searches the satellite identification mapping table according to the terminal identification, obtains the satellite identification of the destination satellite terminal, and if it is the same as the satellite, searches the satellite-to-ground forwarding table and forwards the IP data packet from the user link interface to the destination satellite terminal; Otherwise, the satellite node encapsulates the satellite ID of the destination satellite terminal in the IP data packet, searches the inter-satellite forwarding table according to the satellite ID, and forwards it hop by hop to the satellite node where the destination satellite terminal is located; The satellite node of the destination satellite terminal searches the satellite-to-ground forwarding table according to the terminal identifier and forwards the IP data packet from the user link interface to the destination satellite terminal. After receiving the IP data packet from the user link, the destination satellite terminal determines the terminal identifier in the IP data packet. If it is the same as that of the satellite terminal, the IP data packet is forwarded to the service terminal; otherwise, the IP data packet is discarded.

3. A satellite Internet communication method based on a multi-level identification separation mapping system according to claim 2, characterized in that: In step A, the inter-satellite forwarding table includes information of satellite identifiers, forwarding ports and next-hop satellite identifiers.

4. The satellite Internet communication method based on a multi-level identification separation mapping system according to claim 2, characterized in that: In step B, after receiving the location information message from the feeder link, the satellite mapping server forwards it to all user links and inter-satellite links.

5. A satellite Internet communication method based on a multi-level identification separation mapping system according to claim 4, characterized in that: In step B, after receiving the location information message from the intersatellite link, the satellite mapping server searches the intersatellite forwarding table according to the satellite identifier. If the exit of the intersatellite forwarding table entry is consistent with the message receiving interface, it forwards the message to all intersatellite interfaces and the satellite-to-ground interface except the receiving interface, otherwise the message is discarded.

6. The satellite Internet communication method based on a multi-level identification separation mapping system according to claim 2, characterized in that: In step C, the user identification mapping table includes information of user routing and terminal identification.

7. The satellite Internet communication method based on a multi-level identification separation mapping system according to claim 2, characterized in that: In step D, the satellite identification mapping table includes information of the terminal identification and the satellite identification.

8. The satellite Internet communication method based on a multi-level identification separation mapping system according to claim 2, characterized in that: In step E, the satellite terminal searches the user identification mapping table according to the destination IP address of the IP data packet. If no corresponding entry exists, the satellite terminal sends a user mapping information query message to the user mapping server to obtain the user identification mapping information.

Images