Satellite network route updating method

Abstract

The invention provides a satellite network route updating method, which comprises the following steps: numbering satellites based on orbit information, the numbers comprising orbit numbers and in-orbit numbers; each satellite node generates a shortest path based on the grid topology according to the local link state information; wherein path generation follows the following priority rules: when a source node and a destination node are located on the same layer, a cross-rail link is preferentially selected to switch a rail surface; when the source node and the destination node are located on different layers, the same track plane is preferentially kept to move to the same layer; when the cross-rail link breaks down or is recovered, affected nodes of the affected area are determined, and the affected nodes are nodes at the two ends of the fault link and adjacent nodes on the same rail of the fault link; and updating the shortest path for the affected node according to a reverse path generation rule. Therefore, the routing convergence can be accelerated, and the convergence overhead can be reduced.

Description

Technical Field

[0001] The present invention relates to the field of satellite network technology, and in particular to a satellite network routing update method. Background Art

[0002] Satellites are highly dynamic and large-scale, and satellite networks usually use distributed dynamic routing as a solution. At present, the main implementation method is link state routing based on the SPF (Shortest Path First Algorithm) algorithm, such as ISIS (Intermediate System to Intermediate System, a link state routing protocol) and OSPF (Open Shortest Path First). These methods dynamically collect global link information according to changes in network topology and converge on the optimal routing path. Specifically, in a satellite network, when the topology changes, the satellite network requires global reconvergence of routing. However, the topology of low-orbit satellites changes rapidly, resulting in frequent reconvergence of routing, which in turn causes excessive convergence overhead, as well as potential routing black holes and loops.

[0003] In traditional link state protocols, such as OSPF, each node needs to maintain real-time link state information for the entire network and calculate the shortest path to all other nodes based on this information. When the state of a link changes, the link state update information will be flooded to the entire network. Each node will update the locally maintained link state information based on this information and update the shortest path. Convergence occurs when all nodes complete the update of link state information. However, the convergence speed will decrease as the number of nodes increases, and the scalability has certain limitations. The existing technology lacks consideration of reducing convergence overhead after changes in satellite routing topology. After changes in satellite topology, global reconvergence will be performed, resulting in slow network rerouting convergence and high network routing control overhead. Summary of the invention

[0004] In view of the above-mentioned defects, the purpose of the present invention is to provide a satellite network routing update method, so as to speed up the calculation speed of each path, avoid unnecessary routing convergence, accelerate necessary routing convergence, and thus achieve the purpose of reducing convergence overhead.

[0005] In order to achieve the above technical effects, the present invention provides a satellite network routing update method, comprising the following steps: (1) Satellites are numbered based on orbital information, where the numbering includes an orbital number and an intra-orbital number; wherein the numbering rules of the orbital number and the intra-orbital number are respectively: Assign a unique track number to each track; Locate all satellites over the opposite side of the Earth from the initial satellite snapshot, and globally number the in-orbit satellites in a clockwise direction starting from the satellite at a specific latitude. (2) Each satellite node generates the shortest path based on the grid topology according to the local link state information. Among them, the path generation follows the following priority rules: When the source node and the destination node are on the same layer, preferentially select a cross-track link to switch the orbital plane. When the source node and the destination node are on different layers, preferentially stay on the same orbital plane and move to the same layer. (3) When a cross-track link fails or recovers, determine the affected nodes in the affected area. The affected nodes are the two end nodes of the failed link and their adjacent nodes on the same orbit. Update the shortest path for the affected nodes according to the reverse path generation rule: Among them, the reverse path generation rule is: When the source node and the destination node are on the same layer, preferentially stay on the same orbital plane and move to the same layer. When the source node and the destination node are on different layers, preferentially select a cross-track link to switch the orbital plane.

[0006] Further, the starting point of the in-orbit numbering is the satellite at a certain specific latitude among all orbits over the opposite side of the Earth, and the remaining satellites in the in-orbit are numbered in sequence in a clockwise direction.

[0007] Further, when the affected nodes complete the routing update, the routing state of the entire network converges.

[0008] Further, each satellite node generating the shortest path based on the grid topology according to the local link state information includes: Each satellite node calculates the shortest path to other nodes based on the network topology and the preset priority rules according to the link state information maintained locally.

[0009] Further, the satellite network is a low-Earth orbit satellite network, operating in an orbit 160 kilometers to 2000 kilometers from the Earth's surface.

[0010] Further, updating the shortest path for the affected nodes according to the reverse path generation rule includes: Update the shortest path for the adjacent nodes on the same orbit of the failed link using the non-same-layer cross-track priority rule. Among them, the non-same-layer cross-track priority principle is that when the source node and the destination node are on different layers, preferentially select a cross-track link to switch the orbital plane. Update the shortest path for the two end nodes of the failed link using the same-layer same-orbit priority principle. Among them, the same-layer same-orbit priority principle is that when the source node and the destination node are on the same layer, preferentially stay on the same orbital plane and move to the same layer.

[0011] The satellite network routing update method described in the present invention numbers satellites based on orbital information, and the numbering includes an orbital number and an in-orbit number; each satellite node generates the shortest path based on the local link state information and the grid topology; among them, the path generation follows the following priority rules: when the source node and the destination node are on the same layer, the cross-track link is preferentially selected to switch the orbital plane; when the source node and the destination node are on different layers, the same orbital plane is preferentially maintained and moved to the same layer; when a cross-track link fails or recovers, the affected nodes in the affected area are determined, and the affected nodes are the nodes at both ends of the failed link and their adjacent nodes on the same orbit; the shortest path is updated for the affected nodes according to the reverse path generation rule. By introducing orbital information, the present invention can recalculate the shortest path at the fastest speed within a small range, eliminate the routing failure caused by the fault in the shortest time, and reduce the convergence overhead. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a flowchart of the steps of the satellite network routing update method provided by an embodiment of the present invention; Figure 2 It is a schematic diagram of accurate shortest path convergence under the network topology of the satellite network routing update method provided by an embodiment of the present invention; Figure 3 It is a schematic diagram of the satellite routing update process of the satellite network routing update method provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0013] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0014] It should be noted that the references to "one embodiment", "embodiment", "example embodiment", etc. in this specification mean that the described embodiment may include specific features, structures or characteristics, but not every embodiment must include these specific features, structures or characteristics. In addition, such expressions do not refer to the same embodiment. Further, when combining embodiments to describe specific features, structures or characteristics, whether or not there is an explicit description, it has been shown that it is within the knowledge of those skilled in the art to combine such features, structures or characteristics into other embodiments.

[0015] In addition, in the specification and the subsequent claims, certain terms are used to refer to specific components or parts. Those with ordinary knowledge in the relevant field should understand that the manufacturer can use different nouns or terms to refer to the same component or part. The specification and the subsequent claims do not use the difference in names as a way to distinguish components or parts, but use the difference in the functions of components or parts as the criterion for distinction. The terms "comprising" and "including" mentioned throughout the specification and the subsequent claims are open-ended terms and should therefore be interpreted as "including but not limited to". In addition, the term "connected" herein includes any direct and indirect electrical connection means. Indirect electrical connection means include connection through other devices.

[0016] Before describing the embodiments of the present application in detail, first briefly describe the technical concept of the present application: The present application proposes a localized routing update method based on orbit information, aiming to reduce the convergence range and accelerate path calculation. Specifically, it includes: 1. Orbit information-driven satellite numbering: The satellite numbering is divided into orbit numbering and in-orbit numbering. Through orbit stability and grid topology characteristics, a global logical identification of satellite positions is realized, providing a structured basis for path calculation. 2. Hierarchical path generation rules: When generating the initial route, according to the inter-layer relationship between the source node and the destination node, the path priority of "preferring cross-orbit within the same layer" or "preferring the same orbit between different layers" is dynamically selected to optimize the utilization rate of cross-orbit and same-orbit links and improve path efficiency. 3. Localized dynamic update mechanism: When a cross-orbit link fails or recovers, only the routing update in the affected area is triggered, and rapid re-convergence is achieved through the reverse path generation rule, avoiding full-network flooding updates, and significantly reducing control overhead and convergence delay.

[0017] An important feature of the satellite network topology is the grid topology. The grid topology shape is relatively stable, the relative positions of each satellite node are relatively fixed, and the satellite nodes can use the grid-type orbit information to generate the shortest path to other satellite nodes.

[0018] Satellite network routing update technology is a routing convergence method for satellite networks operating in low orbits between 160 kilometers and 2000 kilometers above the Earth's surface. It forms a routing path through satellite interconnection. These satellites incorporate orbit and in-orbit information, performing the functions of quickly calculating the shortest path and updating the route, and can achieve accelerated routing convergence. In case of a failure, the satellite network routing update technology performs rapid re-calculation of the route through orbit and in-orbit information, achieving rapid re-convergence of the routing in the affected area, as Figure 2 shown.

[0019] Next, the specific principle of the satellite network routing update method of the present application will be described in combination with specific embodiments.

[0020] Figure 1The satellite network routing update method provided by an embodiment of the present invention is shown. The method includes the following steps: S101: Number the satellites based on orbital information. The numbering includes an orbital number and an in-orbital number. Among them, the numbering rules for the orbital number and the in-orbital number are as follows: a. Assign a unique orbital number to each orbit. b. Locate all satellites over the opposite side of the Earth from the initial satellite snapshot, and use the satellites at a specific latitude as the starting point to globally number the in-orbital satellites in a clockwise direction. The starting point of the in-orbital number is the satellite at a certain specific latitude among all orbits over the opposite side of the Earth. The remaining satellites in the orbit are numbered in sequence in a clockwise direction.

[0021] Specifically, for the orbital number, each orbit is assigned a unique number, and all satellites belonging to the same orbit share this number. In the part of the in-orbital numbering, in this embodiment, the initial satellite snapshot is first selected, and then all satellites over the opposite side of the Earth are located in this set of snapshots. The satellite at a certain specific latitude is selected as the starting point of the in-orbital number from all orbits on this side, and the remaining satellites in these orbits are numbered in sequence in a clockwise direction starting from the starting point to achieve global numbering.

[0022] In this embodiment, the satellite numbering is divided into an orbital number and an in-orbital number. Through the orbital stability and grid topology characteristics, a global logical identification of the satellite positions is realized, providing a structured basis for path calculation.

[0023] The satellite network in this embodiment is a low-Earth orbit satellite network, operating in orbits 160 kilometers to 2000 kilometers from the Earth's surface.

[0024] S102: Each satellite node generates the shortest path based on the local link state information and the grid topology. Among them, the path generation follows the following priority rules: c. When the source node and the destination node are in the same layer, preferentially select a cross-orbit link to switch the orbital plane. d. When the source node and the destination node are in different layers, preferentially stay on the same orbital plane and move to the same layer. Specifically, step S102 includes: Each satellite node calculates the shortest path to each other node based on the link state information maintained locally, the network topology, and the preset priority rules.

[0025] That is, based on the network topology, this embodiment generates the shortest path following the principle of "prioritizing cross-track movement on the same layer and prioritizing the same track on different layers"; among them, the above priority rule c is the path generation rule required by the principle of "prioritizing cross-track movement on the same layer", and the above priority d is the path generation rule required by the principle of "prioritizing the same track on different layers"; each node generates the shortest path to each destination node according to the above principle.

[0026] Step S102 is the initial routing generation process. In this process, this embodiment dynamically selects the path priority of "prioritizing cross-track movement on the same layer" or "prioritizing the same track on different layers" according to the inter-layer relationship between the source node and the destination node, optimizes the utilization rate of cross-track and same-track links, and improves the path efficiency.

[0027] S103: When a cross-track link fails or recovers, determine the affected nodes in the affected area. The affected nodes are the two end nodes of the failed link and their adjacent nodes on the same track; update the shortest path for the affected nodes according to the reverse path generation rule: among them, the reverse path generation rule is: e. When the source node and the destination node are on the same layer, prioritize moving on the same track plane to the same layer; f. When the source node and the destination node are on different layers, prioritize selecting a cross-track link to switch the track plane.

[0028] Specifically, when the cross-track link L _cross fails or recovers, only update the routing in the affected area and quickly converge, which can accelerate the convergence speed and reduce the convergence cost. The routing dynamic update process is as Figure 3 shown. The two end nodes N _A , N _B of the failed link will flood the link state update information to the affected area. After the nodes in the affected area receive this information, they generate a new shortest path according to the updated link state. When all the nodes in the affected area complete the update, it represents the completion of convergence.

[0029] The method for defining the affected area is as follows: When a cross-track link is disconnected / reconnected, the adjacent nodes N _A1 , N _A2 , N _B1 , N _B2 on the same track as the end nodes of the cross-track link, a total of six nodes including the two end nodes and their neighbors on the same track (i.e., N _A , N _B , N _A1 , N _A2 , N _B1 , N _B2)( ) is the affected area. The reason is that the shortest path generated by the above six nodes according to the principle of "prioritizing the same orbit" must pass through this faulty link. The shortest paths generated by other nodes need to be relayed through these six nodes. Therefore, only by updating the shortest paths of the above six nodes can the convergence of the routing status of the entire network be completed. By reducing the convergence area, the convergence process is greatly accelerated and the convergence overhead is reduced.

[0030] Further, the updating of the shortest path by generating the reverse path for the affected nodes includes: Updating the shortest path for the nodes adjacent to the faulty link on the same orbit by using the rule of "prioritizing cross-orbit between different layers"; where the rule of prioritizing cross-orbit between different layers means that when the source node and the destination node are on different layers, the cross-orbit link is preferentially selected to switch the orbital plane; Updating the shortest path for the nodes at both ends of the faulty link by using the principle of "prioritizing the same orbit on the same layer"; where the principle of prioritizing the same orbit on the same layer means that when the source node and the destination node are on the same layer, they preferentially move on the same orbital plane to the same layer.

[0031] Specifically, the method for updating the shortest path in the affected area (i.e., the reverse path generation rule) is as follows: The neighbors on the same orbit of the nodes at both ends need to update the shortest path according to the principle of "prioritizing cross-orbit between different layers" (i.e., the above rule f), and the nodes at both ends generate the shortest path according to the principle of "prioritizing the same orbit on the same layer" (i.e., the above rule e). That is, the shortest path is generated according to the principle opposite to the principle of "prioritizing cross-orbit on the same layer and prioritizing the same orbit between different layers". Prioritizing cross-orbit between different layers means that when the source node and the destination node are on different layers, the cross-orbit link is preferentially selected to switch the orbital plane; prioritizing the same orbit on the same layer means that when the source node and the destination node are on the same layer, they preferentially move on the same orbital plane to the same layer.

[0032] Step S103 is a routing dynamic update process, which accelerates convergence by optimizing the shortest path convergence range and reduces the convergence overhead. Specifically, when a cross-orbit link fails or recovers, only the routing update of the affected area (a total of 6 nodes including the nodes at both ends and their neighbors on the same orbit) is triggered, and rapid re-convergence is achieved through the reverse path generation rule ("prioritizing cross-orbit between different layers" or "prioritizing the same orbit on the same layer"), avoiding flooding updates of the entire network, and significantly reducing the control overhead and convergence delay.

[0033] Further, when the affected nodes complete the routing update, the routing status of the entire network is converged. That is, there is no need for other nodes outside the affected nodes to perform routing updates. Only after the affected nodes complete the routing update, the routing status of the entire network is converged, thereby improving the convergence speed and reducing the convergence cost.

[0034] In summary, the satellite network routing update method described in the present invention numbers satellites based on orbital information, where the numbering includes an orbital number and an in-orbital number; each satellite node generates a shortest path based on the local link state information and the grid topology; among them, the path generation follows the following priority rules: when the source node and the destination node are on the same layer, the cross-orbit link is preferentially selected to switch the orbital plane; when the source node and the destination node are on different layers, the same orbital plane is preferentially maintained and moved to the same layer; when a cross-orbit link fails or recovers, the affected nodes in the affected area are determined, and the affected nodes are the nodes at both ends of the failed link and their adjacent nodes on the same orbit; the shortest path is updated for the affected nodes according to the reverse path generation rule. By combining orbital information with a local update strategy, the present invention effectively addresses the challenge of high-frequency changes in the satellite network topology, while ensuring the optimality of the path, significantly reducing the routing convergence overhead, and enhancing the network stability and scalability.

[0035] It should be noted that the present invention can be implemented in software and / or a combination of software and hardware. For example, it can be implemented using an application-specific integrated circuit (ASIC), a general-purpose computer, or any other similar hardware device. In one embodiment, the software program of the present invention can be executed by a processor to implement the above steps or functions. Similarly, the software program of the present invention (including related data structures) can be stored in a computer-readable recording medium, such as a RAM memory, a magnetic or optical drive, or a floppy disk and the like. Additionally, some steps or functions of the present invention can be implemented using hardware, such as a circuit that cooperates with the processor to execute each step or function.

[0036] It should be noted that in this article, the term "comprising", "including" or any other variation thereof is intended to cover a non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device comprising such element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present invention is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in a reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, the features described with reference to certain examples may be combined in other examples.

[0037] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention. However, these corresponding changes and deformations should all fall within the protection scope of the appended claims of the present invention.

Claims

1. A satellite network routing update method, characterized in that, It includes the following steps: (1) Number the satellites based on orbit information, where the numbering includes an orbit number and an in-orbit number; among them, the numbering rules for the orbit number and the in-orbit number are respectively: Assign a unique orbit number to each orbit; Locate all satellites over the opposite side of the Earth from the initial satellite snapshot, and starting from the satellite at a specific latitude, globally number the in-orbit satellites in a clockwise direction; (2) Each satellite node generates the shortest path based on the local link status information and the grid topology; among them, path generation follows the following priority rules: When the source node and the destination node are on the same layer, preferentially select a cross-orbit link to switch the orbital plane; When the source node and the destination node are on different layers, preferentially stay on the same orbital plane and move to the same layer; (3) When a cross-orbit link fails or recovers, determine the affected nodes in the affected area, where the affected nodes are the nodes at both ends of the failed link and their adjacent nodes on the same orbit; update the shortest path for the affected nodes according to the reverse path generation rule: among them, the reverse path generation rule is: When the source node and the destination node are on the same layer, preferentially stay on the same orbital plane and move to the same layer; When the source node and the destination node are on different layers, preferentially select a cross-orbit link to switch the orbital plane.

2. The satellite network routing update method according to claim 1, wherein The starting point of the in-orbit number is the satellite at a certain specific latitude among all orbits over the opposite side of the Earth, and the remaining satellites in the in-orbit are numbered in sequence in a clockwise direction.

3. The satellite network routing update method according to claim 1, wherein When the affected nodes complete the routing update, the routing status of the entire network converges.

4. The satellite network routing update method according to claim 1, characterized in that The generation of the shortest path by each satellite node based on the local link status information and the grid topology includes: Each satellite node calculates the shortest path to other nodes based on the link status information maintained locally, the network topology, and the preset priority rules.

5. The satellite network routing update method according to claim 1, wherein The satellite network is a low-Earth orbit satellite network operating in an orbit 160 kilometers to 2000 kilometers above the Earth's surface.

6. The satellite network routing update method according to claim 1, wherein The update of the shortest path for the affected nodes according to the reverse path generation rule includes: Update the shortest path for the adjacent nodes on the same orbit of the failed link using the non-same-layer cross-orbit priority rule; among them, the non-same-layer cross-orbit priority principle is that when the source node and the destination node are on different layers, preferentially select a cross-orbit link to switch the orbital plane; Update the shortest path for the nodes at both ends of the failed link using the same-layer same-orbit priority principle; among them, the same-layer same-orbit priority principle is that when the source node and the destination node are on the same layer, preferentially stay on the same orbital plane and move to the same layer.

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