Constellation network fusion method based on tunnel encapsulation multi-constellation interconnection routing architecture

Abstract

This invention provides a constellation network fusion method based on a tunnel-encapsulated multi-constellation interconnection routing architecture, belonging to the field of constellation routing calculation technology. The method divides the multi-constellation interconnection routing architecture into a satellite core autonomous system and a satellite user autonomous system according to the application scenario of the satellite network. The satellite core autonomous system adopts a distributed routing strategy and runs a customized internal gateway protocol. Border routers receive packets from the satellite user autonomous systems and encapsulate them with IP headers or link-layer headers before sending them to the satellites. The satellites receiving the packets forward the packets at the network layer or link layer to the destination network satellite terminal or destination gateway. The destination network satellite terminal or destination gateway decapsulates the packets, restoring them to the original IP packets, and sends the original IP packets to the destination network satellite terminal by looking up the routing table or forwarding table based on the destination IP address in the original packets, thus fusion of satellite constellation networks at different construction stages.

Description

TECHNICAL FIELD

[0001] The application relates to a constellation network fusion method based on a tunnel encapsulation multi-constellation interconnection routing architecture and belongs to the technical field of constellation routing calculation. BACKGROUND

[0002] The space-ground integrated information network is a core infrastructure for future information acquisition, distribution, transmission and application, and various constellation networks are important components of the space-based system. How to fuse these networks and realize efficient interconnection is a key problem to be solved in the construction of the space-ground integrated network. Among them, the routing architecture design for realizing network layer fusion is the first technical difficulty to be faced. On the one hand, because various networks are highly heterogeneous, there are great differences in transmission technology, programming strategy, routing protocol and network management, and many challenges are faced in realizing network fusion by using a unified routing architecture. On the other hand, in the long-term process of constructing the space-ground integrated network, various networks are in different construction stages, especially the deployment and configuration of different constellation networks are quite different, which puts forward another difficulty for the routing architecture design.

[0003] The existing technology of space-ground integrated network fusion mainly regards the satellite network as different autonomous systems (AS) and adopts the inter-domain routing mode to fuse two networks. The main works involved at present include: (1) in the routing protocol design aspect: the satellite version of the border gateway protocol, namely BGP-S protocol, is proposed at present. The protocol is an improvement of the BGP v4 protocol version and can realize interoperation with the protocol. BGP-S can realize the automatic discovery of the path through the satellite network and obtain smaller time delay in the space-ground integrated network than BGP-4. In addition, there are documents that propose the Hub &Spoke BGP protocol, consider the limited bandwidth of the star-ground link, utilize the broadcast characteristics of the wireless network to transmit the BGP message and reduce the occupation of bandwidth. (2) in the routing architecture design aspect: researches propose a method for providing connectivity by using the BGP backbone network in the background of the interconnection of mobile air nodes for specific network scenarios. In these scenarios, BGP can be deployed in the satellite network, and each mobile network is an independent AS domain, which are interconnected with each other through BGP. There are researches that analyze different ways of deploying BGP in the DVB-S2 / RCS network. For the routing architecture of the TSAT system, researches propose that the special connection scenarios such as VPNs can be supported by using the policy-based routing filtering method. (3) in the routing performance of the BGP-based satellite network, there are also some discussions on the routing performance, stability, overhead and the like.

[0004] The above work divides the satellite network into different routing domains, only provides a preliminary scheme for realizing network interconnection through the BGP protocol, and still does not discuss specific problems related to the routing architecture design, especially for the characteristics of the existing constellation networks in different deployment stages, and there are still many problems to be solved. SUMMARY

[0005] The present application aims at overcoming the deficiencies in the prior art, and provides a constellation network fusion method based on a tunnel encapsulation multi-constellation interconnection routing architecture, which solves the technical problem of fusing various satellite constellation networks in different construction stages.

[0006] To achieve the above object, the present application adopts the following technical scheme:

[0007] The present application provides a constellation network fusion method based on a tunnel encapsulation multi-constellation interconnection routing architecture, comprising the following steps:

[0008] The multi-constellation interconnection routing architecture is divided into a satellite core autonomous system and a satellite user autonomous system according to the application scenarios of the satellite network, the satellite core autonomous system comprises multiple satellites and a border router, the satellite core autonomous system adopts a distributed routing strategy and runs a customized interior gateway protocol;

[0009] The border router receives original messages from the satellite user autonomous system, performs IP header encapsulation or link layer header encapsulation, and sends to the satellite;

[0010] The satellite forwards the encapsulated message to a destination network satellite terminal or a destination gateway according to the IP address or the link layer address of the encapsulated message header by looking up the on-board routing table or the on-board forwarding table at the network layer or the link layer;

[0011] The destination network satellite terminal or the destination gateway decapsulates the message, restores it to the original message, and sends the original message to a destination user terminal according to the destination IP address in the original message by looking up the ground routing table.

[0012] Further, the satellite running the customized interior gateway protocol only exchanges routing information with peer entities in the satellite core autonomous system, and other routing prefixes are directly forwarded.

[0013] Further, the border router comprises network satellite terminals or gateways, the network satellite terminals, and the gateways run the iBGP protocol.

[0014] Further, the network satellite terminals or gateways obtain the mapping relationship between the link layer address and the IP address of the destination network satellite terminal or the destination gateway through the routing protocol and the ARP protocol.

[0015] Furthermore, the border router and the satellite user autonomous system exchange routing prefixes by running the eBGP protocol.

[0016] Furthermore, the method includes forming different subnets based on the coverage areas of different satellite beams, configuring independent address spaces, and assigning addresses to network satellite terminals and user satellite terminals that match the satellite beams they are located on.

[0017] Furthermore, the IP header encapsulation includes:

[0018] Set the destination address in the new IP header to the IP address of the destination network satellite terminal or destination gateway, encapsulate the original IP packet using this header, and send it to the satellite.

[0019] Furthermore, the link layer header encapsulation includes:

[0020] Set the destination address in the link layer header to the link layer ID of the destination network satellite terminal or destination gateway, encapsulate the original IP packet using this link layer header, and send it to the satellite.

[0021] Furthermore, the distributed routing strategy includes:

[0022] When a satellite is connected to multiple gateways or network satellite terminals, the service traffic that is aggregated at the satellite and needs to be transmitted to the ground is selected according to the capacity and bandwidth usage of the feeder link of the connected gateways or network satellite terminals.

[0023] When a gateway or network satellite terminal connects to multiple satellites, the service traffic that needs to be aggregated at the gateway or network satellite terminal and transmitted to the satellite is selected according to the capacity and bandwidth usage of the feeder link connecting the gateway or network satellite terminal.

[0024] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0025] This invention provides a constellation network fusion method based on a tunnel-encapsulated multi-constellation interconnection routing architecture, which is compatible with existing routing mechanisms, supports interoperability with standard routing protocols, supports the establishment of VPNs with different topologies on demand, has flexible networking capabilities, and provides flexible and diverse routing strategies.

[0026] This paper presents a constellation network fusion method based on a tunnel-encapsulated multi-constellation interconnection routing architecture. By employing a distributed routing strategy, it provides sufficient scalability to support large-scale networks. Satellites only need to perform simple on-board processing, do not require knowledge of external network information, and only run customized internal gateway protocols, facilitating the interconnection of satellite networks deployed at different times. Attached Figure Description

[0027] Figure 1 This is a schematic diagram illustrating an application scenario of the multi-constellation interconnected routing architecture provided in this embodiment of the invention;

[0028] Figure 2 This is a schematic diagram of the multi-constellation interconnection routing architecture provided in an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the routing protocol running in the multi-constellation interconnection routing architecture provided in the embodiments of the present invention;

[0030] Figure 4 This is a schematic diagram of the IP header encapsulation method provided in an embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of the link layer header encapsulation method provided in an embodiment of the present invention. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0033] Example 1

[0034] This invention provides a constellation network fusion method based on a tunnel-encapsulated multi-constellation interconnection routing architecture. The applied network scenario involves multiple satellite networks deployed at different times for different purposes. For example, some satellite networks primarily support narrowband services, such as voice and low-speed data services; others may support broadband services, such as audio and video.

[0035] like Figure 1 The diagram shown is an application scenario illustration of the multi-constellation interconnection routing architecture provided in this embodiment. The constellation network fusion method based on tunnel encapsulation multi-constellation interconnection routing architecture provided by this invention is particularly suitable for geostationary orbit satellite networks, and is also applicable to other types of satellite networks.

[0036] Use the following terminology in application scenarios:

[0037] UST: User Satellite Terminal, an earth station that accesses the satellite network via a user link between a satellite and the ground;

[0038] NST: Network Satellite Terminal, an earth station that accesses the satellite network through a user link between the satellite and the ground, and connects to some ground user subnets.

[0039] GW: Satellite Gateway, an earth station that connects to the satellite network via a feeder link between the satellite and the ground, and also connects to some terrestrial routing autonomous system.

[0040] ISL: Inter-satellite link, a wireless or laser link connecting satellites;

[0041] GSL: Satellite-to-Ground Link, a wireless link connecting earth stations and satellites;

[0042] And SN: Satellite Network, GEO: Geostationary Orbit Satellite, NCC: Network Control Center, ACC: Regional Control Center, AS: Autonomous System, IGP: Interior Gateway Protocol, EGP: Exterior Gateway Protocol, EGP: Border Gateway Protocol, EGP: Address Resolution Protocol.

[0043] The satellite networks in this scenario differ in several ways: each network comprises a different number of GEOs covering a specific area. For example, SN2 and SN3 have four satellites each, while SN1 has three. The satellites in these networks vary in their transmission, processing, and storage capabilities, and they can be interconnected via ISLs.

[0044] Ground-based satellite terminals include various types such as USTs, NSTs, and GWs. NSTs and GWs have routing capabilities, while USTs do not. With the development of integrated space-ground networks, ISLs will be deployed between different satellite networks, or ground links will be added between satellite terminals in different satellite networks, achieving varying degrees of interconnectivity at different deployment stages. Regarding the management and control relationships of the routing architecture, a network control center (NCC) is set up throughout the network, and an area control center (ACC) is set up at a gateway within the satellite coverage area. A gateway can simultaneously view multiple satellites, and a satellite may establish communication links with multiple gateways. Based on the gateway's feeder link capacity and bandwidth usage, different gateways can be selected for services aggregated onto a single satellite, and different gateways can be selected for ground users to access the satellite.

[0045] ACC is responsible for the management of satellite terminals within the corresponding satellite coverage area, the collection of link and traffic status, and the configuration of routing policies.

[0046] like Figure 2 The diagram shown illustrates a multi-constellation interconnection routing architecture provided in an embodiment of the present invention. The routing architecture includes two types of autonomous systems: the satellite core AS and the satellite user AS. All satellites, NSTs, and GWs reside within the satellite core AS, operating the core IGP protocol and exchanging routing information within the satellite core AS.

[0047] Each of the other networks, including user subnets and terrestrial networks, is configured as a separate satellite user AS. NSTs and GWs act as border routers connecting the satellite core ASs and satellite user ASs via eBGP, but NSTs and GWs do not advertise the routing prefixes of the core ASs to the user ASs.

[0048] NSTs and GWs not only need to obtain all reachability information in the satellite core AS through IGP, but also need to obtain routing prefixes from the terrestrial network through the BGP protocol. This invention configures the satellite to only handle limited intra-domain routing information exchanges and directly forwards redistributed routing prefixes from other ASs. Since most of the processing is deployed on the ground, the complexity of on-board processing is greatly reduced.

[0049] This invention provides a constellation network fusion method based on a tunnel-encapsulated multi-constellation interconnection routing architecture, comprising the following steps:

[0050] Based on the application scenarios of satellite networks, the multi-constellation interconnection routing architecture is divided into a satellite core autonomous system and a satellite user autonomous system. The satellite core autonomous system includes multiple satellites and border routers. The satellite core autonomous system adopts a distributed routing strategy and runs a customized internal gateway protocol.

[0051] The border router receives raw packets from the satellite user autonomous system, performs IP header encapsulation or link layer header encapsulation, and sends them to the satellite;

[0052] At the network layer or link layer, the satellite forwards the encapsulated message to the destination network satellite terminal or destination gateway by looking up the on-board routing table or on-board forwarding table, based on the IP address or link layer address in the header of the encapsulated message.

[0053] The destination network satellite terminal or destination gateway decapsulates the message, restores it to the original message, and searches the routing table based on the destination IP address in the original message to send the original message to the destination user terminal.

[0054] like Figure 3 The diagram illustrates the routing protocols operating in the multi-constellation interconnected routing architecture provided in this embodiment. Within the satellite core AS, the IGP protocol runs on satellites, NSTs, and GWs; the eBGP protocol runs between GWs and the terrestrial network to exchange routing prefixes. The iBGP protocol runs between GWs or NSTs. The IGP running on the satellite can be simplified through customization; the satellite only exchanges routing information with peer entities within the satellite core AS, and routing prefixes from other ASs (NSTs or GWs) are directly forwarded by the satellite. Therefore, NSTs or GWs can directly exchange external network information and obtain the IP addresses and link-layer addresses of destination NSTs or GWs connected to the destination network or node.

[0055] When NSTs or GWs receive a message from a terrestrial network, they can determine the destination NST or GW based on the destination IP address in the message and encapsulate the message using the address of the destination NST or GW.

[0056] When NSTs or GWs receive and encapsulate packets from terrestrial networks, they can use two encapsulation methods: one is to encapsulate the packet into another IP header.

[0057] like Figure 4 The diagram illustrates the IP header encapsulation method provided in this embodiment. The destination address in the newly added header is set to the IP address of the destination NST or GW. The packet is transmitted to a satellite. All subsequent satellites receiving the encapsulated packet select a path for it by looking up the onboard routing table based on the destination address in the new header, until the packet reaches the destination NST or GW. Afterward, the destination NST or GW decapsulates the packet, restoring it to the original IP packet, and sends the packet to the destination user terminal by looking up the routing table based on the destination IP address in the original packet.

[0058] In this system, the IGP protocol in the satellite core AS provides all nodes in the satellite core AS with internal path information, while NSTs or GWs obtain external routing information via the BGP protocol. Satellites forward packets only at the network layer and only recognize the satellite's IP address.

[0059] Another encapsulation method is to encapsulate the message in a link-layer frame header instead of an IP header. Figure 5 This is a schematic diagram of the link layer header encapsulation method provided in this embodiment. In the link layer header, the destination address is set to the link layer ID of the destination NSTs or GWs. The original IP packet is encapsulated using this header and transmitted to the satellite. This link layer ID is a label or internal identifier in the core AS, depending on the on-board switching strategy adopted by the system. All subsequent satellite nodes that receive the encapsulated packet forward the packet by looking up the on-board forwarding table based on the link layer ID in the new header. The destination NSTs or GWs decapsulate the encapsulated packet and recover the original IP packet.

[0060] All NSTs or GWs can obtain the mapping relationship between the link-layer ID and IP address of the destination NST or GW through routing protocols and ARP protocols. In this method, the satellite forwards packets at the link layer, and only the satellite's link-layer address needs to be identified.

[0061] In terms of address allocation, the system naturally forms different subnets based on the coverage areas of different satellite beams, configuring independent address spaces. The NCC allocates address space according to the number of satellite terminals in the coverage area of ​​each satellite and distributes it to the ACC for address pool management. The ACC configures the address pool to the onboard DHCP service, and the onboard modules assign addresses corresponding to the access beam subnet to the connected satellite terminals via the DHCP service. When a user terminal directly connects to USTs or NSTs, its address is configured as a private address, and the satellite terminal accesses the satellite via NAT.

[0062] Routing policies can be configured on GWs or NSTs. Load balancing is achieved through routing policy configuration as follows: When a satellite is connected to multiple GWs or NSTs, the service traffic aggregated at the satellite and required to be transmitted to the ground can be selected from different GWs or NSTs based on the capacity and bandwidth usage of the feeder links connecting the GWs or NSTs; When a GW or NST is connected to multiple satellites, the service traffic aggregated at the GW or NST and required to be transmitted to the satellite can be selected from different satellites based on the capacity and bandwidth usage of the feeder links connecting the GWs or NSTs.

[0063] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0064] This application is described with reference to flowchart illustrations and / or block diagrams of methods, systems, and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0065] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0066] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0067] This invention first preprocesses the fingerprint image and extracts features from the region of interest. Then, it proposes a model framework for fingerprint feature extraction from two aspects: the construction of composite pixel gradients and rotation-invariant feature statistics. This enables the detection of real and fake fingerprints. The method is simple and easy to implement, and it improves the accuracy of judging real and fake fingerprints compared with existing technologies.

[0068] The scope of protection of this invention is obviously not limited to these specific embodiments. Without departing from the principles of this invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions resulting from these changes or substitutions will all fall within the scope of protection of this invention.

Claims

1. A constellation network fusion method based on a tunnel encapsulation multi-constellation interconnection routing architecture, characterized in that, The method comprises the following steps: According to the application scenario of the satellite network, the multi-constellation interconnection routing architecture is divided into a satellite core autonomous system and a satellite user autonomous system, the satellite core autonomous system comprises multiple satellites and border routers, the satellite core autonomous system adopts a distributed routing strategy, runs a customized interior gateway protocol, and satellites running the customized interior gateway protocol only exchange routing information with peer entities in the satellite core autonomous system, and other routing prefixes are directly forwarded; The border routers comprise network satellite terminals or gateways, the network satellite terminals, and the gateways run an iBGP protocol; the border routers receive original packets from the satellite user autonomous system, perform IP header encapsulation or link layer header encapsulation, and send the encapsulated packets to the satellites; The satellites forward the encapsulated packets to destination network satellite terminals or destination gateways according to IP addresses or link layer addresses of the encapsulated packet headers at the network layer or the link layer by searching a satellite routing table or a satellite forwarding table; The destination network satellite terminals or the destination gateways decapsulate the packets, restore the original packets, and send the original packets to destination user terminals according to destination IP addresses in the original packets by searching a ground routing table.

2. The constellation network fusion method based on the tunnel encapsulation multi-constellation interconnection routing architecture according to claim 1, characterized in that, The network satellite terminals or the gateways obtain a mapping relationship between link layer addresses and IP addresses of destination network satellite terminals or destination gateways by a routing protocol and an ARP protocol.

3. The constellation network fusion method based on the tunnel encapsulation multi-constellation interconnection routing architecture according to claim 1, characterized in that, The border routers and the satellite user autonomous system exchange routing prefixes by running an eBGP protocol.

4. The constellation network fusion method based on the tunnel encapsulation multi-constellation interconnection routing architecture according to claim 1, characterized in that, The method comprises forming different subnets according to different satellite beam coverage areas, configuring independent address spaces, and respectively allocating addresses matching satellite beams to network satellite terminals and user satellite terminals.

5. The constellation network fusion method based on tunnel encapsulation multi-constellation interconnection routing architecture according to claim 1, characterized in that, The IP header encapsulation comprises: The destination address in the new IP header is set as the IP address of the destination network satellite terminal or the destination gateway, the original IP packet is encapsulated by using the header, and the encapsulated packet is sent to the satellite.

6. The constellation network fusion method based on tunnel encapsulation multi-constellation interconnection routing architecture according to claim 1, characterized in that, The link layer header encapsulation comprises: The link layer destination address in the link layer header is set as the link layer ID of the destination network satellite terminal or the destination gateway, the original IP packet is encapsulated by using the link layer header, and the encapsulated packet is sent to the satellite.

7. The constellation network fusion method based on tunnel encapsulation multi-constellation interconnection routing architecture according to claim 1, characterized in that, The distributed routing strategy comprises: When a satellite is connected to multiple gateways or network satellite terminals, the satellite converges and needs to transmit traffic to the ground, different gateways or network satellite terminals are selected according to the capacity and bandwidth usage of the feeder links of the connected gateways or network satellite terminals; When a gateway or a network satellite terminal is connected to multiple satellites, the gateway or the network satellite terminal converges and needs to transmit traffic to the satellite, and different satellites are selected according to the capacity and bandwidth usage of the feeder links of the connected gateway or network satellite terminal.

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