Low earth orbit satellite network dynamic routing optimization method and system based on domain division routing

Abstract

The invention provides a low earth orbit satellite network dynamic routing optimization method and system based on domain division routing, and the method comprises the steps: dividing a satellite network into a plurality of regions, and distributing a unique IP address for each satellite node; in each region, synchronizing intra-domain topology information through a Hello data packet and a link state notification, and generating an intra-domain routing table; announcing and synchronizing inter-domain topology information through a boundary gateway and a summarized link state, and generating an inter-domain routing table; and forwarding the data packet according to the intra-domain and inter-domain routing tables. According to the invention, the signaling overhead can be reduced, the routing calculation efficiency is improved, the network stability is enhanced, and the network resource utilization is optimized.

Description

Technical Field

[0001] The present invention relates to the technical fields of satellite communication networks and routing algorithms, and particularly to a dynamic routing optimization method and system for a low-earth orbit satellite network based on domain-based routing. Background Art

[0002] Satellite networks have characteristics such as global coverage, dynamic topology, and highly dynamic links, making it difficult for traditional terrestrial routing protocols to be directly applicable.

[0003] Regarding the dynamic routing strategy for satellite networks, it aims to address the dynamic changes in the satellite topology through three methods, namely topology flattening, virtual nodes, and virtual topology. Topology flattening treats the entire low-earth orbit (LEO) satellite network as a two-dimensional plane and assigns each satellite a fixed logical coordinate to shield the dynamic network topology. The virtual node routing algorithm copes with the challenges of dynamic topology by dividing the coverage area, constructing a satellite network model composed of multiple coverage areas, abstracting each coverage area into a virtual node, and assigning it a fixed coordinate. The virtual topology algorithm divides the satellite's operating cycle into multiple time intervals, assumes that the satellite network topology remains unchanged between time intervals, calculates the routing for the current time, first completed by the ground station and then distributed to all satellites in the network.

[0004] As the scale of the satellite network expands, the routing tables maintained by routers increase proportionally, occupying more and more buffer space and CPU computing power, and using more bandwidth to exchange routing status information. Therefore, routing selection must be carried out in a hierarchical manner, that is, dividing routing into intra-domain routing and inter-domain routing for separate calculations.

[0005] Existing hierarchical routing algorithms mainly adopt the hierarchical routing algorithm of the OSPF protocol and the hierarchical routing algorithm of the DHRP protocol.

[0006] The hierarchical routing algorithm of the OSPF (Open Shortest Path First) protocol divides an autonomous system into multiple areas, each with a unique identifier (Area ID). The backbone area (Area 0) is directly connected to other areas and is responsible for the exchange of routing information between areas. Intra-area routing calculation uses the link-state routing algorithm, and inter-area routing is achieved through Type-3 Link State Advertisements (Type-3 LSAs), which are generated and transmitted by Area Border Routers (ABRs). There is a loop prevention mechanism. For example, inter-area routing must pass through Area 0 for transit, and ABRs can only advertise the routing information of directly connected areas to Area 0. This algorithm reduces the amount of routing information exchange by dividing areas, and the hierarchical design simplifies routing calculation and management. However, in this algorithm, Area 0 becomes a potential single point of failure. If there is a problem with Area 0, the stability of the entire network will be affected. Moreover, the traffic of all non-backbone areas must pass through Area 0 for transit, which may lead to excessive traffic pressure on the backbone area. At the same time, ABRs only transmit overall information, which may also result in non-optimal routing selection.

[0007] DHRP (Distributed Hierarchical Routing Protocol) is a hierarchical routing protocol for single-layer satellite networks. It divides areas according to orbits, and each orbit forms a domain. Each orbit elects an Orbit Speaker (PS), which is responsible for the synchronization of inter-domain link-state information. The Orbit Speaker summarizes the link-state information within the orbit, generates S-LSA (Summary Link State Advertisement), and synchronizes it through the PSs of adjacent orbits. The PS uses an extended Dijkstra algorithm to calculate hierarchical routing and generate the optimal primary path and the sub-optimal secondary path. This algorithm divides areas according to orbits, reduces the synchronization scope of inter-domain link-state information, and realizes inter-domain information synchronization through PSs, simplifying routing calculation. However, when a link or node where the Orbit Speaker is located fails, the overhead is huge, affecting network stability. Moreover, the storage and calculation pressure on the Orbit Speaker is relatively large, resulting in waste of on-board resources. All nodes may become Orbit Speakers, and sufficient storage space and computing power need to be reserved for each node during system design, increasing costs. Summary of the Invention

[0008] In view of this, embodiments of the present invention provide a dynamic routing optimization method and system for low-earth orbit satellite networks based on domain-based routing to eliminate or improve one or more defects existing in the prior art.

[0009] On the one hand, the present invention provides a dynamic routing optimization method for low-earth orbit satellite networks based on domain-based routing, and the method includes the following steps:

[0010] Divide the satellite network into multiple regions, each region containing a fixed number of orbits and corresponding satellite nodes per orbit; assign a unique IP address to each satellite node; determine the boundaries of each region and elect border gateways;

[0011] Within each region, each satellite node establishes neighbor relationships by sending Hello packets and receiving Hello packets from other satellite nodes, generating a topological connection relationship; each satellite node generates a link state advertisement based on its own topological connection relationship and forwards it to neighbor nodes within the same region; other satellite nodes add the received link state advertisement to the local link state database and forward it to other neighbors until the link state databases of all satellite nodes within the region are consistent; each satellite node calculates the optimal path to other nodes within the region based on the local link state database and generates an intra-domain routing table;

[0012] Among regions, the border gateway of each region generates a summary link state advertisement, unicasts it via an inter-domain link to the border gateway of an adjacent region and floods it within its own region; other border gateways verify the received summary link state advertisement, store it when it is determined to be a new summary link state advertisement and flood it within its own region; each border gateway calculates the optimal path to other regions based on the summary link state advertisement and generates an inter-domain routing table;

[0013] Forward data packets according to the intra-domain routing table and the inter-domain routing table.

[0014] In some embodiments of the present invention, assigning a unique IP address to each satellite node includes:

[0015] The IP address structure of a satellite node includes a network address segment prefix, a region number, a number of the satellite node within the region, and a port number, with the formula:

[0016] Node IP = Prefix + Area Id + Satellite Id + Interface Id;

[0017] where Node IP represents the IP address of the satellite node; Prefix represents the network address segment prefix; Area Id represents the region number; Satellite Id represents the number of the satellite node within the region; Interface Id represents the port number.

[0018] In some embodiments of the present invention, the method further includes:

[0019] In the satellite network, satellites are classified according to their functions and locations, including ordinary nodes and regional border routers; among them, the regional border routers are used to connect satellite nodes in different regions;

[0020] Within each region, the regional border router with the minimum cost value is elected as the border gateway of this region.

[0021] In some embodiments of the present invention, each satellite node generates a link state advertisement based on its own topological connection relationship, including:

[0022] The link state advertisement includes a common header and connection content;

[0023] Add the region number to the common header part to limit the propagation range of the link state advertisement to the region corresponding to the region number.

[0024] In some embodiments of the present invention, each satellite node calculates the optimal path to other nodes within the region according to the local link state database, and generates an intra-domain routing table, including:

[0025] Each satellite node uses the shortest path first algorithm according to the local link state database to calculate the optimal path to other nodes within the region and generate a routing table entry, and stores it to obtain the intra-domain routing table;

[0026] The entries of the intra-domain routing table include the destination IP address, subnet mask, next-hop IP address, and routing cost.

[0027] In some embodiments of the present invention, after the intra-region information synchronization is completed and before the inter-region information synchronization, the method further includes:

[0028] Each region and the satellite nodes within it serve as the underlying intra-domain network;

[0029] Abstract the entire region as a logical node, and identify it with a unique region number to construct the top-level inter-domain network; use the abstracted logical node as the border gateway of adjacent regions;

[0030] Among them, when two regions communicate through the corresponding border gateway, the communication cost is determined by the minimum cost of all possible links between the two regions.

[0031] In some embodiments of the present invention, each border gateway calculates the optimal path to other regions according to the aggregated link state advertisement, and generates an inter-domain routing table, including:

[0032] Each border gateway uses the shortest path first algorithm according to the aggregated link state advertisement to calculate the optimal path to other regions and generate a routing table entry, and stores it to obtain the inter-domain routing table;

[0033] The entries of the inter-domain routing table include the destination area network segment, the destination area number, the next-hop area number, and the next-hop IP address.

[0034] In some embodiments of the present invention, among each area, the border gateway of each area generates a summary link state advertisement, and further includes:

[0035] The summary link state advertisement carries an increasing sequence number, a time-to-live field, and a unique identifier;

[0036] The sequence number is maintained by the border gateway that generates the summary link state advertisement and is incremented each time a new summary link state advertisement is generated; when the border gateway receives a summary link state advertisement, it determines whether it is a new summary link state advertisement by confirming the sequence number to decide whether to store and forward it;

[0037] Each time the summary link state advertisement is forwarded, the time-to-live field is incremented; when the time-to-live field reaches a preset maximum value, the summary link state advertisement is discarded;

[0038] The border gateway maintains a forwarded list for recording the identifiers of the processed summary link state advertisements; when the border gateway receives a summary link state advertisement, it checks whether its identifier already exists in the forwarded list maintained by the border gateway. If it exists, it is discarded; if not, it is forwarded.

[0039] In some embodiments of the present invention, after obtaining the intra-domain routing table and the inter-domain routing table, the method further includes:

[0040] If a link failure occurs within the area, the failed node generates a new link state advertisement and floods it within the area, triggering all satellite nodes to recalculate and generate the intra-domain routing table;

[0041] If a link failure occurs between areas, the border gateway generates a new summary link state advertisement and relays it through other border gateways, triggering all areas to recalculate and generate the inter-domain routing table;

[0042] Each satellite node updates the latest intra-domain routing table and inter-domain routing table and forwards data packets.

[0043] On the other hand, the present invention also provides a low-earth orbit satellite network dynamic routing optimization system based on domain-based routing, and the system includes:

[0044] A network domain division and addressing module, configured to divide the satellite network into multiple areas and assign a unique IP address to each satellite node;

[0045] An intra-domain routing information synchronization module, which is used to synchronize the topology information of satellite nodes within each area and generate an intra-domain routing table;

[0046] An inter-domain routing information synchronization module, which is used to synchronize the topology information between areas and generate an inter-domain routing table;

[0047] A data forwarding module, which is used to forward data packets according to the generated intra-domain routing table and inter-domain routing table.

[0048] The present invention provides a method and system for dynamic routing optimization of a low-earth orbit satellite network based on domain-based routing, including: dividing the satellite network into multiple areas and assigning a unique IP address to each satellite node; within each area, synchronizing the intra-domain topology information through Hello packets and link state advertisements to generate an intra-domain routing table; synchronizing the inter-domain topology information through border gateways and summary link state advertisements to generate an inter-domain routing table; and forwarding data packets according to the intra-domain and inter-domain routing tables.

[0049] Specifically, through the domain-based routing mechanism, the present invention restricts the synchronization of topology information to local areas, reduces the signaling flooding in the entire network, and significantly reduces the signaling overhead. Through the hierarchical routing calculation within the domain and between domains, the complexity of routing calculation is reduced, and the efficiency and response speed of routing calculation are improved.

[0050] Furthermore, by dynamically updating the routing table and quickly handling link failures, the impact of single-point failures on the entire network is avoided, and the stability and robustness of the network are enhanced. Through a reasonable domain division design and border gateway mechanism, the traffic pressure problem of the backbone area in the traditional OSPF protocol is avoided. The utilization of network resources is optimized. Through the routing algorithm based on topological snapshots and the timeliness management of summary link state advertisements, the high-dynamic topological changes of the low-earth orbit satellite network can be effectively addressed, ensuring the timeliness and accuracy of routing information.

[0051] The additional advantages, objectives, and features of the present invention will be partially described below, and will become partially apparent to those of ordinary skill in the art after studying the following text, or can be learned from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures specifically pointed out in the specification and the drawings.

[0052] Those skilled in the art will understand that the objectives and advantages that can be achieved by the present invention are not limited to the above specific descriptions, and the above and other objectives that the present invention can achieve will be more clearly understood according to the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The drawings described herein are used to provide a further understanding of the present invention, form a part of this application, and do not limit the present invention. In the drawings:

[0054] Figure 1 It is a schematic diagram of the steps of the low-earth orbit satellite network dynamic routing optimization method based on domain-based routing in an embodiment of the present invention.

[0055] Figure 2 It is a schematic diagram of the process of in-domain information synchronization in an embodiment of the present invention.

[0056] Figure 3 It is a schematic diagram of the inter-domain routing structure in an embodiment of the present invention.

[0057] Figure 4 It is a schematic diagram of the process of inter-domain information synchronization in an embodiment of the present invention.

[0058] Figure 5 It is a schematic diagram of the global topological relationship in an embodiment of the present invention.

[0059] Figure 6 It is a schematic diagram of the topological relationship between regions in an embodiment of the present invention. Detailed implementation manners

[0060] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in combination with the implementation manners and the accompanying drawings. Herein, the illustrative implementation manners and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0061] Herein, it also needs to be noted that in order to avoid obscuring the present invention due to unnecessary details, only the structures and / or processing steps closely related to the solution according to the present invention are shown in the drawings, while other details less related to the present invention are omitted.

[0062] It should be emphasized that the term "including / containing" when used herein refers to the presence of features, elements, steps or components, but does not exclude the presence or addition of one or more other features, elements, steps or components.

[0063] Herein, it also needs to be noted that if not otherwise specified, the term "connection" in this article can not only refer to a direct connection, but also represent an indirect connection with an intermediate.

[0064] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals represent the same or similar components, or the same or similar steps.

[0065] It should be emphasized here that the step labels mentioned hereinafter are not intended to limit the order of the steps. Instead, it should be understood that the steps can be executed in the order mentioned in the embodiments, can be different from the order in the embodiments, or several steps can be executed simultaneously.

[0066] To solve the problems existing in the existing hierarchical routing algorithm, such as the backbone area being prone to single-point failures, high traffic pressure, and the large storage and computing pressure of orbital speakers, resulting in waste of on-board resources and high repair overhead during failures, the present invention provides a dynamic routing optimization method for low-Earth orbit satellite networks based on domain-based routing, as Figure 1 shown. The method includes the following steps S101 to S104:

[0067] Step S101: Divide the satellite network into multiple regions, each region containing a fixed number of orbits and the corresponding satellite nodes per orbit; assign a unique IP address to each satellite node; determine the boundaries of each region and elect border gateways.

[0068] Step S102: Within each region, each satellite node establishes neighbor relationships by sending Hello packets and receiving Hello packets from other satellite nodes, generating a topological connection relationship; each satellite node generates a link state advertisement based on its own topological connection relationship and forwards it to neighbor nodes within the same region; other satellite nodes add the received link state advertisement to the local link state database and forward it to other neighbors until the link state databases of all satellite nodes within the region are consistent; each satellite node calculates the optimal path to other nodes within the region according to the local link state database and generates an intra-domain routing table.

[0069] Step S103: Among regions, the border gateway of each region generates a summary link state advertisement, unicasts it to the border gateways of adjacent regions through inter-domain links and floods it within its own region; other border gateways verify the received summary link state advertisement, store it when it is determined to be a new summary link state advertisement and flood it within its own region; each border gateway calculates the optimal path to other regions according to the summary link state advertisement and generates an inter-domain routing table;

[0070] Step S104: Forward data packets according to the intra-domain routing table and the inter-domain routing table.

[0071] In step S101, the satellite network is divided into multiple regions, each region containing a fixed number of orbits and the number of satellites per orbit, and adjacent regions are connected through border gateways. A unique IP address is assigned to each satellite node.

[0072] In some embodiments, the address segment design of the satellite network supports IPv4 (Internet Protocol Version 4) and IPv6 (Internet Protocol Version 6) formats, having good flexibility and scalability.

[0073] In some embodiments, as an address segment of the satellite network, for the sake of convenience in representation, the IP composition of satellite nodes is simplified. As shown in formula (1), the IP address structure of satellite nodes is:

[0074] Node IP = Prefix + Area ID + Satellite ID + Interface ID; (1)

[0075] Among them, Node IP represents the IP address of the satellite node; Prefix represents the prefix of the network address segment; Area ID is the area number, representing the area to which the satellite node belongs; Satellite ID represents the number of the satellite node within the area; InterfaceID represents the port number, used to identify the interface of the satellite node.

[0076] Thus, the IP fields of satellite nodes are composed as shown in Table 1:

[0077] Table 1 Composition of Satellite Node IP Fields

[0078] Prefix Area ID Satellite ID Interface ID

[0079] In step S102, the topological information of satellite nodes is synchronized within each area to generate an intra-domain routing table.

[0080] As Figure 2 shown, it is a flowchart of intra-domain information synchronization. Specifically, at the beginning of each time slot, satellite nodes within the area send Hello packets containing information such as the area number (Area ID) from the port to announce their existence. After other satellite nodes receive it, they extract the area number and determine whether it is the same as their own area number. If it is the same, it means they belong to the same area. If it is different, it means they do not belong to the same area, and they mark themselves as Area Border Routers (ABRs), establish neighbor relationships with adjacent satellite nodes, and generate topological connection relationships, including information such as neighbor nodes and link costs. Each satellite node generates a Link State Advertisement (LSA) according to its own topological connection relationship.

[0081] In some embodiments, the description of the link state advertisement within each link state advertisement entry can be divided into a common header and connection content. Among them, the common header part is mainly used to describe the attributes of the link state advertisement, such as link state type, identification ID, source, sequence number, checksum length. Add the area number to the original common header part to limit the propagation range of the link state advertisement to the area corresponding to the area number.

[0082] As shown in Table 2, it is the fields included in the link state advertisement common header and their meanings.

[0083] Table 2 Composition of Link State Advertisement Common Header

[0084]

[0085]

[0086] Among them, the router link state advertisement contains a description of the topological relationship of satellite nodes. It mainly includes the following content: satellite node interface IP, neighbor node IP, router ID of neighbor nodes, and corresponding link costs, etc. As shown in Table 3, it is the fields included in the router link state advertisement and their meanings.

[0087] Table 3 Composition of Router Link State Advertisement Body

[0088]

[0089] Each satellite node within the area maintains a retransmission list and a local link state database (Link State DataBase, LSDB). Each satellite node places the link state advertisement in the retransmission list and forwards it to neighbor nodes within the same area. When the confirmation information returned by the neighbor node is received, the corresponding link state advertisement is deleted from the retransmission list.

[0090] When other satellite nodes receive the link state advertisement forwarded by a neighbor, they add the link state advertisement to the local link state database and continue to forward it to neighbor nodes within the same area through the retransmission list until the link state databases of all satellite nodes within the area are consistent, that is, the in-domain information synchronization is completed.

[0091] After the link state database synchronization is completed, each satellite node within the area has completed the construction of the in-area topological view. On this basis, each satellite node runs the Shortest Path First (SPF) algorithm, that is, the Dijkstra algorithm, to calculate the shortest path to other nodes within the area, that is, the optimal path, and then generates a routing table entry, stores the routing table entry in the preset routing table, and generates an in-domain routing table. Exemplarily, the table entry composition of the in-domain routing table is <destination IP address, subnet mask, next-hop IP address, routing cost>.

[0092] In step S103, synchronize topological information between areas to generate an inter-domain routing table.

[0093] In some embodiments, after the in-domain link state database synchronization is completed, from the area border routers, select the area border router with the minimum cost value as the border gateway of this area. The border gateway sends a gateway announcement to other area border routers connecting to the same neighborhood to announce the completion of the border gateway election.

[0094] By dividing a large-scale satellite network into multiple regions, the flooding scope and quantity of topology information synchronization control messages in the whole network can be effectively reduced. However, due to the still large number of nodes within each region and the overall scale of the regions, when performing inter-domain topology information updates, the length of the intra-domain summary message packets sent is relatively long, consuming a large amount of network resources. Therefore, the present invention proposes a method for abstracting each region as a node for inter-domain routing calculation, as Figure 3 shown.

[0095] In a satellite network, each satellite can be classified into a general node and an area border router (ABR) according to its function and location. Among them, the general node is the basic unit in the satellite network, mainly responsible for data forwarding and routing calculation of intra-domain link state announcements and summary link state announcements. The area border router is the node connecting different regions, responsible for electing border gateways, data forwarding and routing calculation of intra-domain link state announcements and summary link state announcements. After calculating the next area ID according to the summary link state announcement information, query the intra-domain routing table and the summary link state announcement to select the area border router with the minimum cross-domain cost as the exit of the area. The border gateway is the area border router with the minimum cost value on the same neighborhood border, responsible for generating summary link state announcements and relaying all the summary link state announcements received in this domain to the neighboring domain. The number of border gateways is equal to the number of neighboring domains of the area.

[0096] Based on the above node identity definitions, as Figure 3 shown, each area and the satellite nodes within it serve as the underlying intra-domain network. The entire area (including all nodes within the area) is abstracted as a logical node and identified with a unique area number to construct the top-level inter-domain network, and the abstracted logical node is used as the border gateway between adjacent areas. When two areas communicate through the corresponding border gateways, the communication cost is determined by the minimum cost of all possible links between the two areas. This method not only simplifies the routing management process but also significantly reduces the signaling cost, thus improving the overall operation efficiency of the network.

[0097] As Figure 4 shown, it is the flowchart of inter-domain information synchronization. After the border gateway in each area completes intra-domain information synchronization, it generates summary link state announcements for this area and its directly adjacent areas, unicasts them through the inter-domain link to the border gateways of the corresponding adjacent areas, and floods them within its own area

[0098] For the nodes in any region, the link state information between all domains is stored. The inter-domain link information is stored through a special type of link state advertisement called Summary Link State Advertisement (SLSA), which is used to summarize the inter-domain link information of all area border routers in the same neighborhood. The summary link state advertisement is used to summarize the neighbor relationships between regions. As shown in Table 4, it includes an Age field, the IP address of the corresponding area border router, the local area number, the adjacent area number, and the link cost between regions. Routers within the region can obtain the router IDs and IP addresses of the border gateway and area border routers by parsing the information encapsulated in the summary link state advertisement, thus providing the necessary data support for the next stage of route calculation.

[0099] Table 4 Composition of the summary link state advertisement body

[0100]

[0101]

[0102] When other (adjacent) border gateways receive the summary link state advertisement, they first perform a uniqueness check on the summary link state advertisement. The check is carried out through the information such as the generated area number, border gateway IP address, and adjacent area number carried by it. If it is repeated, it is directly discarded; if not, it is stored. When it is a new summary link state advertisement, after storage, it is flooded to all border gateways within the region through the intra-domain link to ensure that other border gateways in the same region synchronize this information. Repeat the above steps, and the summary link state advertisement gradually covers all regions through the relay forwarding of border gateways, completing the inter-domain information synchronization.

[0103] After the inter-domain information synchronization is completed, each border gateway uses the Shortest Path First (SPF) algorithm, that is, the Dijkstra algorithm, according to the summary link state advertisement to calculate the shortest path to other regions, that is, the optimal path, and then generates a routing table entry, stores the routing table entry in the preset routing table, and generates an inter-domain routing table. Exemplarily, the entry composition of the inter-domain routing table is <destination area network segment, destination area number, next-hop area number, next-hop IP address>.

[0104] In some embodiments, based on Table 4, it can be seen that the summary link state advertisement carries an increasing sequence number, an Age field, and a unique identifier.

[0105] The sequence number is maintained by the border gateway that generates the summary link state advertisement, and is incremented each time a new summary link state advertisement is generated. When the border gateway receives the summary link state advertisement, it compares the sequence number to determine whether the information is new or old. If it is an old summary link state advertisement, it is directly discarded to avoid overwriting the new information. If it is a new summary link state advertisement, it is stored and forwarded.

[0106] Each time a summary link state advertisement is forwarded, the time-to-live field is incremented. When the time-to-live field reaches the preset maximum value, the summary link state advertisement is discarded to prevent outdated information from being propagated indefinitely in the network.

[0107] The border gateway maintains a forwarded list to record the identifiers of the processed summary link state advertisements. When the border gateway receives a summary link state advertisement, it checks whether its identifier already exists in the forwarded list maintained by the border gateway. If it exists, it is discarded. If not, it is forwarded. In addition, the forwarded list is cleaned up regularly to delete expired records to reduce storage and computing overhead.

[0108] By setting a sequence number and a unique identifier, it is possible to ensure that new information replaces old information in a timely manner and avoid repeated forwarding. The lifetime field and forwarded list further limit the propagation range and time of the summary link state announcement to prevent loops and outdated information from being retained. These designs jointly ensure the efficient and reliable propagation of the summary link state announcement, while reducing network overhead and ensuring the consistency and timeliness of the topology information of the entire network.

[0109] In step S104, data packets are forwarded according to the intra-domain routing table and the inter-domain routing table. Specifically, if the destination node is in the same area, the intra-domain routing table is searched and the shortest path is selected to forward the data packet; if the destination node is in another area, the inter-domain routing table is searched and the optimal border gateway is selected for cross-domain forwarding. Based on the cost information in the routing table, the optimal path is dynamically selected to ensure the efficiency of data transmission.

[0110] In some embodiments, dynamically maintaining a routing table and handling link failures include:

[0111] If a link failure occurs in the area, the failed node generates a new link state notification and floods it in the area, triggering all satellite nodes to recalculate and generate the routing table within the domain.

[0112] If a link failure occurs between regions, the border gateway generates a new summary link status announcement and forwards it through other border gateways, triggering all regions to recalculate and generate inter-domain routing tables.

[0113] Each satellite node updates the latest intra-domain routing table and inter-domain routing table to forward data packets.

[0114] In the following, a specific embodiment is used to further illustrate the present invention.

[0115] According to the domain-based routing mechanism, the satellite network is divided. In this embodiment, as Figure 5 shown, the satellite network is divided into 4 regions, with 9 nodes in each region. The regional border router with the minimum cost value is elected as the border gateway for this region (the nodes with darker gray in the figure are the border gateways).

[0116] According to the method of abstracting each region as a node for inter-domain routing calculation mentioned above, Figure 6 a schematic diagram of the inter-regional topological relationship is obtained.

[0117] After obtaining the intra-domain and inter-domain topological relationships, according to the dynamic routing optimization method for low-earth orbit satellite networks based on domain-based routing provided by the present invention, the intra-domain routing table and the inter-domain routing table are calculated, as shown in Table 5 and Table 6 respectively.

[0118] Table 5 Intra-domain Routing Table

[0119]

[0120] Table 6 Inter-domain Routing Table

[0121]

[0122] Corresponding to the dynamic routing optimization method for low-earth orbit satellite networks based on domain-based routing, the present invention also provides a dynamic routing optimization system for low-earth orbit satellite networks based on domain-based routing. The system includes:

[0123] A network domain division and addressing module, which is used to divide the satellite network into multiple regions and assign a unique IP address to each satellite node.

[0124] An intra-domain routing information synchronization module, which is used to synchronize the topological information of satellite nodes within each region and generate an intra-domain routing table.

[0125] An inter-domain routing information synchronization module, which is used to synchronize topological information between regions and generate an inter-domain routing table.

[0126] A data forwarding module, which is used to forward data packets according to the generated intra-domain routing table and inter-domain routing table.

[0127] Corresponding to the above method, the present invention also provides an electronic device. The electronic device includes a computer device. The computer device includes a processor and a memory. Computer instructions are stored in the memory. The processor is used to execute the computer instructions stored in the memory. When the computer instructions are executed by the processor, the electronic device implements the steps of the method described above.

[0128] An embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the foregoing edge computing server deployment method are implemented. The computer-readable storage medium may be a tangible storage medium, such as a random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, register, floppy disk, hard disk, removable storage disk, CD-ROM, or any other form of storage medium well known in the technical field.

[0129] Those of ordinary skill in the art should understand that the various exemplary components, systems, and methods described in conjunction with the embodiments disclosed herein can be implemented in hardware, software, or a combination of both. Specifically, whether to implement in hardware or software depends on the specific application and design constraints of the technical solution. A person skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention. When implemented in hardware, it can be, for example, an electronic circuit, an application-specific integrated circuit (ASIC), appropriate firmware, a plug-in, a functional card, and so on. When implemented in software, the elements of the present invention are programs or code segments used to perform the required tasks. The program or code segment can be stored in a machine-readable medium or transmitted through a data signal carried in a carrier wave on a transmission medium or a communication link.

[0130] It should be clear that the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order between steps after understanding the spirit of the present invention.

[0131] In the present invention, the features described and / or illustrated for one embodiment can be used in the same manner or in a similar manner in one or more other embodiments, and / or combined with the features of other embodiments or replace the features of other embodiments.

[0132] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, various changes and modifications can be made to the embodiments of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A dynamic routing optimization method for low-earth orbit satellite networks based on domain-based routing, characterized in that The method includes the following steps: Divide the satellite network into multiple regions, where each region contains a fixed number of orbits and corresponding satellite nodes per orbit; assign a unique IP address to each satellite node; determine the boundaries of each region and elect border gateways; Within each region, each satellite node establishes neighbor relationships by sending Hello packets and receiving Hello packets from other satellite nodes, generating a topological connection relationship; each satellite node generates a link state advertisement based on its own topological connection relationship and forwards it to neighbor nodes within the same region; other satellite nodes add the received link state advertisement to the local link state database and forward it to other neighbors until the link state databases of all satellite nodes within the region are consistent; each satellite node calculates the optimal path to other nodes within the region based on the local link state database and generates an intra-domain routing table; Among regions, the border gateway of each region generates a summary link state advertisement, unicasts it via an inter-domain link to the border gateway of an adjacent region and floods it within its own region; other border gateways verify the received summary link state advertisement, store it when it is determined to be a new summary link state advertisement and flood it within its own region; each border gateway calculates the optimal path to other regions based on the summary link state advertisement and generates an inter-domain routing table; Forward data packets according to the intra-domain routing table and the inter-domain routing table.

2. The dynamic routing optimization method for low-earth orbit satellite network based on domain-based routing according to claim 1, wherein Assigning a unique IP address to each satellite node includes: The IP address structure of a satellite node includes a network address segment prefix, a region number, a number of the satellite node within the region, and a port number, with the formula: Node IP = Prefix + AreaID + Satellite ID + Interface ID; where NodeIP represents the IP address of the satellite node; Prefix represents the network address segment prefix; AreaID represents the region number; Satellite ID represents the number of the satellite node within the region; Interface ID represents the port number.

3. The dynamic routing optimization method for a low-earth orbit satellite network based on domain-based routing according to claim 1, wherein The method further includes: In the satellite network, satellites are classified according to their functions and locations, including ordinary nodes and regional border routers; among them, the regional border routers are used to connect satellite nodes in different regions; Within each region, elect the regional border router with the minimum cost value as the border gateway of this region.

4. The dynamic routing optimization method for low-earth orbit satellite networks based on domain-based routing according to claim 1, characterized in that Each satellite node generates a link state advertisement based on its own topological connection relationship, including: The link state advertisement includes a common header and connection content; Add the region number to the common header part to limit the propagation range of the link state advertisement to the region corresponding to the region number.

5. The dynamic routing optimization method for a low-earth orbit satellite network based on domain-based routing according to claim 1, wherein Each satellite node calculates the optimal path to other nodes within the region based on the local link state database and generates an intra-domain routing table, including: Each satellite node, based on the local link state database, uses the shortest path first algorithm to calculate the optimal path to other nodes within the region and generate routing table entries, and stores them to obtain the intra-domain routing table; The entries in the intra-domain routing table include the destination IP address, subnet mask, next-hop IP address, and routing cost.

6. The dynamic routing optimization method for a low-earth orbit satellite network based on domain-based routing according to claim 1, wherein After the intra-region information synchronization is completed and before the inter-region information synchronization, the method further includes: Each region and its internal satellite nodes serve as the underlying intra-domain network; Abstract the entire region as a logical node, identify it with a unique region number, and construct the top-level inter-domain network; use the abstracted logical node as the border gateway between adjacent regions; Among them, when two regions communicate through the corresponding border gateways, the communication cost is determined by the minimum cost of all possible links between the two regions.

7. The dynamic routing optimization method for a low-earth orbit satellite network based on domain-based routing according to claim 1, characterized in that Each border gateway calculates the optimal path to other regions according to the aggregated link state advertisement, and generates an inter-domain routing table, including: Each border gateway uses the shortest path first algorithm according to the aggregated link state advertisement to calculate the optimal path to other regions and generate routing table entries, and stores them to obtain the inter-domain routing table; The entries in the inter-domain routing table include the destination region network segment, destination region number, next-hop region number, and next-hop IP address.

8. The dynamic routing optimization method for low-earth orbit satellite networks based on domain-based routing according to claim 1, wherein Among regions, when each region's border gateway generates an aggregated link state advertisement, it further includes: The aggregated link state advertisement carries an incrementing sequence number, a time-to-live field, and a unique identifier; The sequence number is maintained by the border gateway that generates the aggregated link state advertisement and increments each time a new aggregated link state advertisement is generated; when the border gateway receives an aggregated link state advertisement, it determines whether it is a new aggregated link state advertisement by confirming the sequence number, so as to decide whether to store and forward it; Each time the aggregated link state advertisement is forwarded, the time-to-live field increments; when the time-to-live field reaches the preset maximum value, the aggregated link state advertisement is discarded; The border gateway maintains a forwarded list for recording the identifiers of the processed aggregated link state advertisements; when the border gateway receives an aggregated link state advertisement, it checks whether its identifier already exists in the forwarded list maintained by the border gateway. If it exists, it discards it; if not, it forwards it.

9. The dynamic routing optimization method for low-earth orbit satellite networks based on domain-based routing according to claim 1, characterized in that After obtaining the intra-domain routing table and the inter-domain routing table, the method further includes: If a link failure occurs within a region, the faulty node generates a new link state advertisement and floods it within the region, triggering all satellite nodes to recalculate and generate the intra-domain routing table; If a link failure occurs between regions, the border gateway generates a new aggregated link state advertisement and relays it through other border gateways, triggering all regions to recalculate and generate the inter-domain routing table; Each satellite node updates the latest intra-domain routing table and inter-domain routing table and forwards data packets.

10. A dynamic routing optimization system for low-earth orbit satellite networks based on domain-based routing, characterized in that, The system includes: A network domain division and addressing module for dividing the satellite network into multiple regions and assigning a unique IP address to each satellite node; An intra-domain routing information synchronization module for synchronizing the topological information of satellite nodes within each region and generating an intra-domain routing table; An inter-domain routing information synchronization module for synchronizing topological information between regions and generating an inter-domain routing table; A data forwarding module for forwarding data packets according to the generated intra-domain routing table and inter-domain routing table.

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