An inter-satellite label routing method suitable for low-orbit satellite networks

Abstract

According to the characteristics of low-orbit satellite networks, the present invention designs an inter-satellite label routing method suitable for low-orbit satellite networks. The method centrally calculates the inter-satellite label routing based on time slices, injects the inter-satellite label routing based on time slices into the satellite through the gateway station, controls the forwarding table of the onboard switch, and can adjust the inter-satellite label routing based on time slices on the satellite in real time. The present invention is applicable to a variety of low-orbit networks and can effectively reduce the onboard storage and processing pressure.

Description

Technical Field

[0001] The invention discloses an inter-satellite label routing method suitable for a low-orbit satellite network, and relates to the field of inter-satellite routing exchange in the field of satellite communications. Background Art

[0002] Low-orbit satellite networks are characterized by high-speed information transmission, on-board routing exchange, and relay capabilities. Due to the limited onboard node resources and dynamic changes in network topology of low-orbit satellite networks, the application of ground-based distributed routing protocols in low-orbit satellite networks has high requirements for memory and processors, and cannot quickly adapt to dynamic changes in network topology. It needs to be designed in combination with the characteristics of low-orbit satellite networks.

[0003] The low-orbit satellite network draws on the idea of ​​terrestrial software-defined networking, separating routing calculation from switching and forwarding. Complex routing calculations are placed at ground gateway stations, and the onboard switches mainly implement data plane switching and forwarding. Summary of the invention

[0004] The technical problem to be solved by the present invention is to combine the on-board processing capability of low-orbit satellites and the characteristics of dynamic changes in low-orbit satellite networks, and propose an inter-satellite label routing method suitable for low-orbit satellite networks, which is used for inter-satellite routing of low-orbit satellite networks. In particular, it is used to solve the problem of difficult routing convergence under the condition of limited on-board processing capability and dynamic changes in inter-satellite topology.

[0005] The technical solution adopted by the present invention is:

[0006] An inter-satellite label routing method applicable to a low-orbit satellite network comprises the following steps:

[0007] (1) The space-based network controller uses the low-orbit satellite ephemeris information as input and divides the inter-satellite network topology within an orbital period into multiple time slices. The path algorithm is used to calculate the inter-satellite unicast routing in each time slice.

[0008] (2) The space-based network controller injects time slices into the onboard SDN agent through the gateway station;

[0009] (3) The onboard SDN agent controls the forwarding table of the onboard switch based on the stored time slices.

[0010] Further includes:

[0011] (4) If the end time of the time slice stored by the onboard SDN agent is less than the current time, the space-based network controller increases the start time and end time of the time slice by one orbital period.

[0012] (5) If the inter-satellite link is abnormal, the space-based network controller recalculates the inter-satellite unicast route of the time slice corresponding to the current moment and injects the time slice into the onboard SDN agent, which stores the time slice in the onboard switch.

[0013] Wherein, in step (1), each time slice includes: a start time, an end time and an inter-satellite unicast route.

[0014] Wherein, in step (1), if the difference between the end time and the start time of a time slice is less than a set value, the time slice is merged with an adjacent time slice.

[0015] Among them, in step (1), low-latitude inter-orbit links and intra-orbit links are preferentially used when calculating the time slice path.

[0016] Among them, in step (2), the space-based network controller injects time slices into the onboard SDN agent through multiple gateway stations according to the actual connection status of the feeder link and the inter-satellite link.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] 1. The present invention uses the ephemeris information of low-orbit satellites as input and can be applied to various types of satellite constellations.

[0019] 2. When the present invention copes with normal changes in low-orbit inter-satellite links, the routing reconvergence time is in the millisecond level.

[0020] 3. The present invention can process rerouting caused by low-orbit satellite node anomalies and low-orbit inter-satellite link anomalies in real time.

[0021] 4. The present invention adopts a centralized computing mechanism, which can effectively shorten the problem of slow routing convergence in low-orbit satellite networks and reduce the on-board processing and storage pressure of low-orbit satellites. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of an application scenario of the present invention.

[0023] Figure 2 It is a work flow chart of the present invention. DETAILED DESCRIPTION

[0024] The present invention is applicable to low-orbit satellite network scenarios. Figure 1 , 2 The present invention is further described. Figure 1 is a schematic diagram of an application scenario of the present invention, Figure 2 It is a work flow chart of the present invention.

[0025] Reference Figure 1The present invention illustrates an intersatellite label routing method suitable for a low-orbit satellite network, which is implemented based on a network composed of multiple low-orbit satellites using intersatellite links. The space-based network controller deployed at the ground center station centrally calculates the intersatellite label routing and injects it into the low-orbit satellite-borne switch according to the periodic change law of the low-orbit satellite topology. In order to deal with satellite network anomalies, the low-orbit satellites monitor the intersatellite link status in real time. When the satellite is destroyed, the intersatellite link is interrupted or interfered, the space-based network controller calculates the affected route and updates the route in the entire network.

[0026] Reference Figure 2 , an inter-satellite label routing method applicable to a low-orbit satellite network, comprising the following steps:

[0027] (1) The space-based network controller uses the ephemeris information of low-orbit satellites as input to divide the inter-satellite network topology into multiple time slices, and the satellite topology remains unchanged within the time slice. Time slices with a duration less than a certain value can be merged with other time slices. Each time slice includes the start time of the time slice, the end time of the time slice, the interrupted satellite link of the time slice, the time slice trigger event, neighbor information, and routing information. The space-based network controller uses the path algorithm to calculate the inter-satellite routing according to the network topology of the time slice, sets higher weight values ​​for low-latitude inter-orbit links and same-orbit links, and sets lower weight values ​​for high-latitude inter-orbit links that are about to be closed or restored. Links with high weight values ​​are given priority in centralized path calculations;

[0028] (2) The space-based network controller uses multiple gateway stations to inject inter-satellite time slices into the onboard SDN agent. Each gateway station is responsible for injecting time slices of a part of satellites.

[0029] (3) The satellite-based SDN agent controls the unicast label forwarding table of the satellite-based switch. The satellite-based routing switch maintains two tables, which store the label forwarding table at the current moment and the label forwarding table at the next moment;

[0030] (4) The space-based network controller controls the switching time of the on-board time slice. The on-board SDN agent can autonomously control the switching of the on-board time slice when the space-based network controller is abnormal;

[0031] (5) The space-based network controller adjusts the forwarding table content of the current time slice in real time according to abnormal changes in the intersatellite link.

Claims

1. An inter-satellite label routing method applicable to a low-orbit satellite network, characterized in that: The following steps are involved: (1) The space-based network controller uses the ephemeris information of low-orbit satellites as input and divides the inter-satellite network topology within an orbital period into multiple time slices. The path algorithm is used to calculate the inter-satellite unicast route for each time slice. Each time slice includes: a start time, an end time, and an inter-satellite unicast route. If the difference between the end time and the start time of a time slice is less than a set value, the time slice is merged with the adjacent time slice. (2) The space-based network controller injects time slices into the onboard SDN agent through the gateway station; (3) The onboard SDN agent controls the forwarding table of the onboard switch based on the stored time slices; (4) If the end time of the time slice stored by the onboard SDN agent is less than the current time, the space-based network controller increases the start and end time of the time slice by one orbital period; (5) If the inter-satellite link is abnormal, the space-based network controller recalculates the inter-satellite unicast route for the time slice corresponding to the current moment and injects the time slice into the onboard SDN agent, which then stores the time slice in the onboard switch.

2. The inter-satellite label routing method applicable to a low-orbit satellite network according to claim 1, characterized in that: In step (1), low-latitude inter-orbit links and intra-orbit links are preferentially used in the time slice path calculation.

3. The inter-satellite label routing method applicable to a low-orbit satellite network according to claim 1, characterized in that: In step (2), the space-based network controller injects time slices into the onboard SDN agent through multiple gateway stations according to the actual connection status of the feeder link and the inter-satellite link.

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