Low earth orbit satellite constellation based srv6 traffic transmission method

Abstract

The application provides a low-orbit satellite constellation SRv6-based traffic transmission method, comprising the following steps: determining a head node and a tail node of a satellite constellation according to a source gateway station and a destination gateway station; configuring an End-SPA type SID at the source gateway station; taking a satellite serving as a current next hop of the source gateway station as the head node, calculating an SRv6 Policy path conforming to a link SLA according to a satellite topology at a current time, and configuring a BSID associated with the End-SPA to guide a flow into the SRv6 Policy path; and performing traffic forwarding. The traffic transmission method can realize data transmission between cross domains under large constellation networking and reduce the calculation pressure.

Description

Technical Field

[0001] This invention relates to the field of satellite communications, and specifically to a traffic transmission method for a low-Earth orbit satellite constellation based on SRv6. Background Technology

[0002] Currently, the general approach to dividing the topology of low-Earth orbit (LEO) satellite constellation networks is to virtualize the constellation network topology over time, leveraging the periodicity and predictability of its operation. This involves dividing the constellation's operational cycle into several time segments, with the constellation system's topology remaining unchanged within each time segment. For example, patent application number 201911338144.7, entitled "A Method and Apparatus for Inter-Satellite Routing Selection in a LEO Communication Satellite Constellation," utilizes the periodicity of the satellite constellation by calculating multiple (user-to-gateway) routing tables. This eliminates the need for the telemetry, tracking, and command (TT&C) system to periodically update and upload the routing tables; the constellation network only needs to call the routing tables according to time segments, effectively reducing the workload of the ground control system.

[0003] For example, application number 202310641713.5, patent titled "A Routing Update Method, Apparatus, Communication Satellite, and Storage Medium," describes a method for updating a communication satellite. This patent obtains the ephemeris information of the communication satellite, which represents the satellite's location within a preset time period and the changing angle between the optical transceiver in the laser terminal configured on the communication satellite and the sun. By doing so, it eliminates devices potentially affected by solar interference during routing calculations, preventing link switching caused by subsequent device failures due to solar interference.

[0004] Patent application number 201911338144.7 only considers the routing layer, calculating multiple paths at a given moment using time slices to forward traffic. This scheme offers some optimization for simple network configurations, but has limitations for large satellite constellations. Patent application number 202310641713.5 performs routing calculations by eliminating devices potentially affected by solar interference, ensuring normal communication between satellites even under such conditions. However, it lacks a solution for link switching in other scenarios, still relying on route convergence, resulting in a still significant computational burden.

[0005] To adapt to the traffic forwarding of large satellite constellations and reduce the pressure of routing calculations, it is particularly important to design a traffic transmission method for low-Earth orbit satellite constellations based on SRv6. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a traffic transmission method for low-Earth orbit satellite constellations based on SRv6.

[0007] This invention provides a traffic transmission method for a low-Earth orbit satellite constellation based on SRv6, comprising: determining the head node and tail node of the satellite constellation according to the source gateway station and the destination gateway station; configuring an End-SPA type SID at the source gateway station; using the satellite of the current next hop of the source gateway station as the head node, calculating an SRv6 Policy path that conforms to the link SLA according to the satellite topology at the current time, and configuring a BSID associated with the End-SPA to redirect traffic to the SRv6 Policy path; and performing traffic forwarding.

[0008] According to one embodiment of the present invention, determining the head node and tail node of the satellite constellation includes: the source gateway station selecting the head node and tail node of the satellite constellation with the optimal path based on real-time ephemeris data and link status.

[0009] According to one embodiment of the present invention, the step of calculating an SRv6 Policy path conforming to the link SLA based on the current satellite topology and configuring the BSID associated with the End-SPA to direct traffic to the SRv6 Policy path includes: calculating a primary SRv6 Policy path and a backup SRv6 Policy path and setting corresponding priorities; configuring a BSID for the SRv6 Policy path; the SRv6 Policy path is associated with the End-SPA, and the backup SRv6 Policy path remains active.

[0010] According to one embodiment of the present invention, after configuring the BSID for the SRv6 Policy path, the method further includes: deploying a detection mechanism to detect the primary SRv6 Policy path and the backup SRv6 Policy path; the traffic forwarding includes: using the primary SRv6 Policy path for traffic forwarding while verifying the reachability of the backup SRv6 Policy path; if the primary SRv6 Policy path detects a failure, switching to the backup SRv6 Policy path for traffic forwarding; if the primary SRv6 Policy path recovers, detecting the primary SRv6 Policy path again and switching back to the primary SRv6 Policy path for traffic forwarding.

[0011] According to one embodiment of the present invention, after calculating an SRv6 Policy path conforming to the link SLA based on the satellite of the current next hop of the source gateway station as the head node, and configuring the BSID associated with the End-SPA to be redirected to the SRv6 Policy path, the method further includes: detecting whether the satellite pointed to by the source gateway station has changed; if the satellite pointed to by the source gateway station has changed, then recalculating a new SRv6 Policy path with the new satellite as the head node.

[0012] According to one embodiment of the present invention, after taking the satellite of the current next hop of the source gateway station as the head node, calculating an SRv6 Policy path that conforms to the link SLA based on the satellite topology at the current time, and configuring the BSID associated with the End-SPA to be redirected to the SRv6 Policy path, the method further includes: determining whether the satellite network involves satellite interconnection in different orbital planes; if it involves satellite interconnection in different orbital planes, the head node obtains the topology of the next time slice based on the ephemeris, calculates the candidate SRv6 Policy path for the next time that conforms to the link SLA, and installs the candidate SRv6 Policy path for the next time as a candidate path for the next time into the SRv6 Policy path.

[0013] According to one embodiment of the present invention, the traffic forwarding further includes: calculating the remaining lifetime of the SRv6 Policy path based on ephemeris; if the remaining lifetime of the SRv6 Policy path is not within the optimal lifetime, detecting the status of the candidate SRv6 Policy path at the next moment; if the status of the candidate SRv6 Policy path at the next moment is UP, obtaining the initial time; calculating the remaining lifetime of the candidate SRv6 Policy path at the next moment based on ephemeris; if the remaining lifetime of the candidate SRv6 Policy path at the next moment is within the optimal lifetime, then using the candidate SRv6 Policy path at the next moment for traffic forwarding and deleting the SRv6 Policy path; if the remaining lifetime of the candidate SRv6 Policy path at the next moment is not within the optimal lifetime, then continuing to use the SRv6 Policy path for traffic forwarding; when the remaining lifetime of the SRv6 Policy path reaches a critical point and the status of the candidate SRv6 Policy path at the next moment is UP, then switching to the candidate SRv6 Policy path at the next moment for traffic forwarding.

[0014] According to one embodiment of the present invention, after continuing to use the SRv6 Policy path for traffic forwarding if the remaining lifetime of the candidate SRv6 Policy path at the next moment is not within the optimal lifetime, the method further includes: detecting the status of the SRv6 Policy path; if the status of both the primary SRv6 Policy path and the backup SRv6 Policy path is DOWN, then switching to using the candidate SRv6 Policy path at the next moment for traffic forwarding.

[0015] According to one embodiment of the present invention, calculating a candidate SRv6 Policy path for the next time step that conforms to the link SLA includes: calculating a primary candidate SRv6 Policy path and a backup candidate SRv6 Policy path for the next time step, and setting corresponding priorities; configuring the primary candidate SRv6 Policy path for the next time step with the same BSID as the SRv6 Policy path; associating the candidate SRv6 Policy path for the next time step with an End-SPA, and keeping the backup candidate SRv6 Policy path for the next time step in an inactive state.

[0016] According to one embodiment of the present invention, detecting the state of the candidate SRv6 Policy path at the next time step includes: using SRv6 Path Verify to detect the state of the candidate SRv6 Policy path at the next time step.

[0017] The low-Earth orbit satellite constellation based traffic transmission method of the present invention can reduce the inter-satellite routing calculation overhead by binding the fixed satellite beam coverage area covered by the gateway station through End-SPA.

[0018] It should be understood that the above general description and the following specific embodiments are merely exemplary and illustrative, and do not limit the scope of the invention. Attached Figure Description

[0019] The accompanying drawings, which are part of the specification of this invention, illustrate exemplary embodiments of the invention. The drawings, together with the description in the specification, serve to illustrate the principles of the invention.

[0020] Figure 1 This is a schematic diagram of a low-Earth orbit satellite constellation based on SRv6 traffic transmission method according to an embodiment of the present invention;

[0021] Figure 2 This is an example diagram of a low-Earth orbit satellite constellation based on SRv6 traffic transmission method according to an embodiment of the present invention. Detailed Implementation

[0022] The features and exemplary embodiments of various aspects of the present invention will now be described in detail. 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 specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present invention and to exemplify the principles of the present invention, and are not configured to limit the present invention. In addition, the structural components in the drawings are not necessarily drawn to scale. For example, the dimensions of some structural components or regions in the drawings may be enlarged for other structural components or regions to aid in the understanding of the embodiments of the present invention.

[0023] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of the embodiments of the present invention. In the description of the present invention, it should be noted that, unless otherwise stated, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0024] Furthermore, the terms "comprising," "including," "having," or any other variations thereof are intended to cover non-exclusive inclusion, such that a structure or component that includes a list of elements includes not only those elements but also other structural elements that are not expressly listed or inherent to the structure or component. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the article or apparatus that includes the element.

[0025] Spatial relation terms such as "below," "under," "under," "low," "above," "on," and "high" are used for descriptive convenience to explain the positioning of one element relative to a second element, indicating that these terms are intended to cover different orientations of the device, in addition to those different from those shown in the figure. Furthermore, phrases such as "one element on / below another element" can indicate that two elements are in direct contact, or that there are other elements between the two elements. In addition, terms such as "first" and "second" are also used to describe individual elements, areas, parts, etc., without specifically indicating order or sequence, and should not be considered restrictive. Similar terms are used throughout the description to represent similar elements.

[0026] It will be apparent to those skilled in the art that the present invention can be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention.

[0027] Terminology definition:

[0028] SRv6 (Segment Routing IPv6) is a source routing technology based on IPv6 that enables explicit programming of network paths by extending the IPv6 packet header.

[0029] End-SPA type SID (Segment ID) is a 128-bit IPv6 address used in the SRv6 (Segment Routing IPv6) architecture to identify the dynamic next-hop address.

[0030] End-B6 is a behavior directive in SRv6 (Segment Routing IPv6) technology, used to control the forwarding path of data packets.

[0031] Figure 1 This is a schematic diagram of a low-Earth orbit satellite constellation based on SRv6 traffic transmission method according to an embodiment of the present invention; Figure 2 This is an example diagram of a low-Earth orbit satellite constellation based on SRv6 traffic transmission method according to an embodiment of the present invention.

[0032] like Figure 1 As shown, this invention provides a traffic transmission method for low-Earth orbit satellite constellations based on SRv6, comprising:

[0033] S01: Determine the head node and tail node of the satellite constellation based on the source gateway station and the destination gateway station;

[0034] S02: Configure an End-SPA type SID at the source gateway station;

[0035] S03: Using the satellite that is the next hop of the source gateway station as the head node, calculate an SRv6 Policy path that conforms to the link SLA based on the satellite topology at the current time, and configure the BSID associated with the End-SPA to redirect traffic to the SRv6 Policy path;

[0036] S04: Perform traffic forwarding.

[0037] Specifically, End-SPA (End-Space) is a new type of SRv6 SID, indicating that the next hop for traffic forwarding is the fixed satellite beam coverage area of ​​the current gateway station. The outgoing interface of this SID actively switches with each time slot, and IGP convergence calculation is not performed when the outgoing interface state remains unchanged. Since routers within the same domain often share the same prefix, only the node changes, by creating a new End-SPA type SID with a dynamic next-hop address and correspondingly modifying the End-B6 SID, the same BSID (representing an SRv6 Policy path to the destination gateway station) can be established for the sky corresponding to different time slots. This modified End-B6 type SID must be used simultaneously with the End-SPA type SID.

[0038] In this embodiment, the SID can contain the next hop of multiple satellites. The overall path is the ground equipment network, the gateway station End-SPA type SID, and the satellite network BSID.

[0039] This traffic transmission method leverages the continuity of links to low-Earth orbit satellite routers at the gateway station nodes. This ensures that the IGP is unaware of end-SPA type SID switching topologies during calculations, thus ignoring SID topology changes and reducing computational burden. Furthermore, this method utilizes the periodicity of satellite constellations in path calculation. By using a basic topology where there is always a path for forwarding between two gateway stations, a common BSID is abstracted, ensuring the entire end-to-end path remains unchanged. This reduces the need for forwarding path updates in the telemetry, tracking, and command (TT&C) system. The constellation network only needs to call path selection according to the SRv6 Policy, effectively reducing the workload of the ground control system. This traffic transmission method enables data transmission across domains (two fixed gateway stations) in large-scale constellation networks.

[0040] According to one embodiment of the present invention, determining the head node and tail node of a satellite constellation includes:

[0041] Based on real-time ephemeris data and link status, the source gateway selects the head and tail nodes of the satellite constellation with the optimal path.

[0042] According to one embodiment of the present invention, an SRv6 Policy path conforming to the link SLA is calculated based on the current satellite topology, and the BSID associated with the End-SPA is configured to be redirected to the SRv6 Policy path, including:

[0043] S031: Calculate a primary SRv6 Policy path and a backup SRv6 Policy path, and set the corresponding priorities;

[0044] S032: Configure BSID for SRv6 Policy path;

[0045] S033: The SRv6 Policy path is associated with End-SPA, and the backup SRv6 Policy path remains active.

[0046] In this embodiment, the priorities of the primary SRv6 Policy path and the backup SRv6 Policy path can be set based on SLA parameters. For example, the path with a latency ≤ 5ms is the primary path, and the path with a latency ≤ 10ms is the backup path.

[0047] According to one embodiment of the present invention, after configuring BSID for the SRv6 Policy path, the method further includes: S0321: deploying a detection mechanism to detect the primary SRv6 Policy path and the backup SRv6 Policy path.

[0048] Traffic forwarding includes:

[0049] S041: Use the primary SRv6 Policy path for traffic forwarding, and at the same time verify the reachability of the backup SRv6 Policy path;

[0050] S042: If a failure is detected in the primary SRv6 Policy path, the system will switch to the backup SRv6 Policy path for traffic forwarding.

[0051] S043: If the primary SRv6 Policy path recovers, then the primary SRv6 Policy path is checked again, and traffic is switched back to the primary SRv6 Policy path for forwarding.

[0052] In this embodiment, for example, if the packet loss rate of the primary SRv6 Policy path is >1% or the latency is >20ms, then the system switches to the backup SRv6 Policy path for traffic forwarding. If the primary SRv6 Policy path recovers, then the primary SRv6 Policy path is checked again. For example, if the primary SRv6 Policy path remains stable for 30 seconds, then the system switches back to the primary SRv6 Policy path for traffic forwarding.

[0053] According to one embodiment of the present invention, after using the satellite of the current next hop of the source gateway station as the head node, calculating the SRv6 Policy path that conforms to the link SLA based on the satellite topology at the current time, and configuring the BSID associated with the End-SPA to be redirected to the SRv6 Policy path, the method further includes:

[0054] S034: Detect whether the direction of the source gateway station towards the satellite has changed;

[0055] S035: If the source gateway station points to a different satellite, a new SRv6 Policy path is recalculated using the new satellite as the head node.

[0056] The traffic transmission method in this embodiment ensures the forwarding of data traffic by actively switching the internal paths of the SRv6 Policy, which can effectively reduce the performance pressure caused by link calculation and link distribution during topology switching.

[0057] According to one embodiment of the present invention, after using the satellite of the current next hop of the source gateway station as the head node, calculating an SRv6 Policy path conforming to the link SLA based on the satellite topology at the current time, and configuring the BSID associated with the End-SPA to be redirected to the SRv6 Policy path, the method further includes:

[0058] S036: Determine whether the satellite network involves interconnection of satellites in different orbital planes;

[0059] S037: If satellite interconnection is involved in different orbital planes, the head node obtains the topology of the next time slice based on the ephemeris, calculates the candidate SRv6 Policy path for the next time that meets the link SLA, and installs the candidate SRv6 Policy path for the next time as the candidate path for the next time into the SRv6 Policy path.

[0060] Specifically, for clarity in the preceding and following statements of this application, the lifecycle is described as follows: A satellite in one orbit may link with two satellites in different orbits. The lifecycle of the first satellite is defined as the period from when the first satellite is linked until when the first satellite is disconnected. When the second satellite is linked, the first satellite may not yet be disconnected.

[0061] The traffic transmission method provided in this embodiment divides time slices by ephemeris. For large satellite constellation orbital scenarios, when the source node and destination node remain unchanged, it can ensure smooth switching of traffic paths between the source and destination nodes in multiple time slices, effectively reducing routing awareness.

[0062] According to one embodiment of the present invention, traffic forwarding further includes:

[0063] S044: Calculate the remaining survival time of the SRv6 Policy path based on the ephemeris;

[0064] S045: If the remaining lifetime of the SRv6 Policy path is not within the optimal lifetime, check the status of the candidate SRv6 Policy paths at the next moment;

[0065] S046: If the state of the candidate SRv6 Policy path in the next time step is UP, derive the initial time;

[0066] S047: Calculate the remaining survival time of the candidate SRv6 Policy path at the next moment based on the ephemeris;

[0067] S048: If the remaining lifetime of the candidate SRv6 Policy path at the next moment is within the optimal lifecycle, then the candidate SRv6 Policy path at the next moment is used for traffic forwarding, and the SRv6 Policy path is deleted.

[0068] S049: If the remaining lifetime of the candidate SRv6 Policy path at the next moment is not within the optimal lifetime, then the SRv6 Policy path will continue to be used for traffic forwarding. When the remaining lifetime of the SRv6 Policy path reaches a critical point (for example, a critical point can be preset), and the status of the candidate SRv6 Policy path at the next moment is UP, then the traffic will be switched to the candidate SRv6 Policy path at the next moment.

[0069] In the traffic transmission method provided in this embodiment, for the SRv6 Policy path corresponding to the BSID, the forwarding path of the next time slice is calculated, the lifetime of the current path and the path of the next time slice is recorded, and the path status of the next time slice is verified. When the path of the next time slice is available and its lifetime is good, the system actively switches to the next time slice, completing the smooth switching of the onboard router path in a large constellation network. This traffic transmission method makes full use of the multi-path state of the low-Earth orbit satellite constellation network when establishing a topology with other orbits, converting the result of dynamic network topology changes into lifetime, reducing the link instability time in the early stage of link establishment and when the link is about to be lost, and increasing link reliability. This traffic transmission method analyzes the cross-orbit scenario of the constellation network, fully considers the link switching scenario of low-Earth orbit constellation satellites communicating with other orbits, and has the advantages of fast path switching and low requirements for satellite equipment performance. This traffic transmission method has significant advantages in terms of adaptability and feasibility, and is very suitable for path optimization in large low-Earth orbit satellite constellations. Furthermore, the inter-satellite path switching method of this traffic transmission method can effectively reduce the packet loss rate and make the path switching smoother compared to the ordinary link disconnection and reconstruction method.

[0070] In this embodiment, if the remaining lifetime of the primary SRv6 Policy path is not within its optimal lifespan, traffic forwarding is switched to the backup SRv6 Policy path. If the remaining lifetime of both the primary and backup SRv6 Policy paths is not within their optimal lifespans, the status of the candidate SRv6 Policy path at the next moment is checked. If the remaining lifetime of the candidate SRv6 Policy path at the next moment is within its optimal lifespan, then the candidate SRv6 Policy path at the next moment is used for traffic forwarding.

[0071] According to one embodiment of the present invention, if the remaining lifetime of the candidate SRv6 Policy path at the next moment is not within the optimal lifetime, after continuing to use the SRv6 Policy path for traffic forwarding, the method further includes:

[0072] S050: Detect SRv6 Policy path status;

[0073] S051: If both the primary SRv6 Policy path and the backup SRv6 Policy path are in the DOWN state, then switch to using the candidate SRv6 Policy path for traffic forwarding in the next moment.

[0074] According to one embodiment of the present invention, the optimal lifespan can be 80% of the total lifespan.

[0075] In this embodiment, the optimal lifespan of both the SRv6 Policy path and the candidate SRv6 Policy path at the next moment is 80% of their total lifespan. This traffic transmission method enables lifespan management of dynamic topo paths.

[0076] According to one embodiment of the present invention, calculating a candidate SRv6Policy path for the next time step that conforms to the link SLA includes:

[0077] Calculate the primary candidate SRv6 Policy path and the backup candidate SRv6 Policy path for the next time step, and set the corresponding priorities.

[0078] Configure the primary candidate SRv6 Policy path for the next time step with the same BSID as the SRv6 Policy path;

[0079] The candidate SRv6 Policy path for the next time step is associated with End-SPA, while the alternative candidate SRv6 Policy path for the next time step remains in an inactive state.

[0080] According to one embodiment of the present invention, detecting the state of the candidate SRv6 Policy path at the next time step includes:

[0081] The status of the candidate SRv6 Policy path (i.e. the next time slice path obtained in step S037) is detected by using SRv6 Path Verify.

[0082] In this embodiment, when there are enough BFD sessions, BFD can also be used to detect the status of candidate SRv6 Policy paths in the next time slot. In this traffic transmission method, the on-board candidate path design adopts the next time slot alternative path strategy, and uses path verify or BFD to detect the connectivity status of the path, which improves the satellite's ability to cope with sudden satellite node or link failures and other problems, thereby improving the reliability and disaster recovery of the low-Earth orbit satellite constellation network.

[0083] A detailed example of the traffic transmission method for low-Earth orbit satellite constellations based on SRv6 of the present invention is as follows:

[0084] S001: Low Earth orbit constellation satellites determine the head and tail nodes of the satellite constellation based on the source gateway station and the destination gateway station;

[0085] S002: Configure an End-SPA type SID at the source gateway station;

[0086] S003: Using the satellite that is currently the next hop of the source gateway station as the head node, calculate the primary SRv6 Policy path and backup SRv6 Policy path that conform to the link SLA according to the satellite topology at the current time, and set the corresponding priorities;

[0087] S004: Configure BSID for SRv6 Policy path;

[0088] S005: Deploy a detection mechanism to detect the primary SRv6 Policy path and the backup SRv6 Policy path;

[0089] S006: The SRv6 Policy path is associated with End-SPA, and the backup SRv6 Policy path remains active.

[0090] S007: Detect whether the direction of the source gateway station towards the satellite has changed;

[0091] S008: If the satellite pointed to by the source gateway changes, a new SRv6 Policy path is recalculated with the new satellite as the head node (i.e., S003-S006 is repeated).

[0092] S009: If the source gateway station does not point to a satellite, determine whether the satellite network involves interconnection of satellites in different orbital planes;

[0093] S0010: If satellite interconnection between different orbital planes is involved, the head node obtains the topology of the next time slice based on the ephemeris, calculates the candidate SRv6 Policy path for the next time that meets the link SLA, and installs the path as the candidate path for the next time into the SRv6 Policy path; if no inter-orbit scenario is involved, traffic forwarding is performed according to S0011-S0013.

[0094] S0011: Use the primary SRv6 Policy path for traffic forwarding, and verify the reachability of the backup SRv6 Policy path at the same time;

[0095] S0012: If a failure is detected in the primary SRv6 Policy path, the system will switch to the backup SRv6 Policy path for traffic forwarding.

[0096] S0013: If the primary SRv6 Policy path recovers, then the primary SRv6 Policy path is checked again, and traffic is switched back to the primary SRv6 Policy path for forwarding.

[0097] S0014: Calculate the remaining survival time of the primary SRv6 Policy path and the backup SRv6 Policy path based on the ephemeris;

[0098] S0015: If the remaining lifetime of the primary SRv6 Policy path and the backup SRv6 Policy path is not within the optimal lifetime (for example, taking 80% of the entire lifetime as the optimal lifetime), check the status of the candidate SRv6 Policy path at the next moment.

[0099] S0016: If the state of the candidate SRv6 Policy path in the next moment is UP, derive the initial time;

[0100] S0017: Calculate the remaining survival time of the candidate SRv6 Policy path at the next moment based on the ephemeris (for example, take 80% of the entire life cycle as the optimal survival time).

[0101] S0018: If the remaining lifetime of the candidate SRv6 Policy path at the next moment is within the optimal lifecycle, then the candidate SRv6 Policy path at the next moment will be used for traffic forwarding, and the SRv6 Policy path will be deleted.

[0102] S0019: If the remaining lifetime of the candidate SRv6 Policy path at the next moment is not within the optimal lifetime, then the SRv6 Policy path will continue to be used for traffic forwarding; when the remaining lifetime of the SRv6 Policy path is close to the critical point and the status of the candidate SRv6 Policy path at the next moment is UP, then the traffic will be switched to the candidate SRv6 Policy path at the next moment.

[0103] S0020: Detect SRv6 Policy path status;

[0104] S0021: If both the primary SRv6 Policy path and the backup SRv6 Policy path are in the DOWN state, then switch to using the candidate SRv6 Policy path for the next time step for traffic forwarding.

[0105] like Figure 2 As shown, an example of traffic forwarding using the SRv6-based traffic transmission method for low-Earth orbit satellite constellations according to the present invention is as follows: Gateway1 and Gateway2 are ground gateway stations. When traffic from Gateway1 is transmitted to Gateway2, the SID of the End-SPA is configured on Gateway1, and its outgoing interface and next hop include multiple laser routers such as LaserRouter1 and LaserRouter2. Laser links follow a first-in, first-out principle; when the outgoing interface of the End-SPA switches from LaserRouter1 to LaserRouter2, the SID state remains unchanged, and the IGP does not detect this.

[0106] During traffic forwarding, the next hop for an End-SPA is a fixed, modified End-B6 type SID, which contains an SRv6 Policy. To ensure continuous data transmission, each laser router has a route to the other end.

[0107] For example, such as Figure 2 As shown, the path from LaserRouter-1 to Gateway-2 is:

[0108] LaserRouter-1→LaserRouter-4→LaserRouter-5→LaserRouter-6→Gateway2.

[0109] When the next time slice Gateway1 is linked to LaserRouter-2, such as Figure 2 As shown, the path from LaserRouter2 to Gateway2 is:

[0110] LaserRouter-2→LaserRouter-5→LaserRouter-6→LaserRouter-7→Gateway-2.

[0111] The above embodiments of the present invention can be combined with each other and have corresponding technical effects.

[0112] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for SRv6-based traffic transmission of a low earth orbit satellite constellation, characterized in that, The application relates to a satellite network traffic forwarding method and device. The head node and the tail node of a satellite constellation are determined according to a source gateway station and a destination gateway station; An End-SPA type SID is configured at the source gateway station; wherein the End-SPA type refers to a traffic forwarding next hop being a fixed satellite beam coverage area covered by a current gateway station; the out-interface of the End-SPA type SID is actively switched with time slices; and a same BSID is established for different time slices through the gateway station corresponding to the sky; A satellite serving as a current next hop of the source gateway station is taken as the head node, a SRv6 Policy path conforming to a link SLA is calculated according to a satellite topology at a current moment, and a BSID associated with the End-SPA is configured to guide flow into the SRv6 Policy path; Whether the satellite pointed to by the source gateway station changes is detected; If the satellite pointed to by the source gateway station changes, a new SRv6 Policy path is recalculated by taking a new satellite as the head node; Traffic is forwarded.

2. The traffic transmission method according to claim 1, wherein, The determination of the head node and the tail node of the satellite constellation comprises: The source gateway station selects the head node and the tail node of the satellite constellation according to real-time ephemeris data and a link state.

3. The method of Claim 1, wherein, The calculation of the SRv6 Policy path conforming to the link SLA according to the satellite topology at the current moment and the configuration of the BSID associated with the End-SPA to guide flow into the SRv6 Policy path comprise: A main SRv6 Policy path and a backup SRv6 Policy path are calculated, and corresponding priorities are set; The SRv6 Policy path is configured with the BSID; The SRv6 Policy path is associated with the End-SPA, and the backup SRv6 Policy path is kept in an active state.

4. The method of claim 3, wherein, After the SRv6 Policy path is configured with the BSID, the method further comprises: A detection mechanism is deployed to detect the main SRv6 Policy path and the backup SRv6 Policy path; The traffic forwarding comprises: The main SRv6 Policy path is used for traffic forwarding, and the reachability of the backup SRv6 Policy path is verified; If the main SRv6 Policy path detects a fault, the backup SRv6 Policy path is switched to for traffic forwarding; If the main SRv6 Policy path recovers, the main SRv6 Policy path is detected again, and the main SRv6 Policy path is switched back to for traffic forwarding.

5. The method of claim 4, wherein, After the satellite serving as the current next hop of the source gateway station is taken as the head node, the SRv6 Policy path conforming to the link SLA is calculated according to the satellite topology at the current moment, and the BSID associated with the End-SPA is configured to guide flow into the SRv6 Policy path, the method further comprises: Whether the satellite network involves satellite interconnection of different orbital planes is judged. If the satellite interconnection involves different orbital planes, the head node derives a topology of a next time slice according to ephemeris, calculates a candidate SRv6 Policy path of a next time that meets a link SLA, and installs the candidate SRv6 Policy path of the next time as a candidate path of the next time into the SRv6 Policy path.

6. The method of transmitting traffic according to claim 5, wherein, The performing the traffic forwarding further includes: calculating a remaining lifetime of the SRv6 Policy path according to ephemeris; if the remaining lifetime of the SRv6 Policy path is not within an optimal lifetime, detecting a state of the candidate SRv6 Policy path of the next time; if the state of the candidate SRv6 Policy path of the next time is UP, deriving an initial time; calculating a remaining lifetime of the candidate SRv6 Policy path of the next time according to ephemeris; if the remaining lifetime of the candidate SRv6 Policy path of the next time is within the optimal lifetime, performing the traffic forwarding by using the candidate SRv6 Policy path of the next time, and deleting the SRv6 Policy path; if the remaining lifetime of the candidate SRv6 Policy path of the next time is not within the optimal lifetime, continuing to perform the traffic forwarding by using the SRv6 Policy path; if the remaining lifetime of the SRv6 Policy path reaches a critical point and the state of the candidate SRv6 Policy path of the next time is UP, switching to perform the traffic forwarding by using the candidate SRv6 Policy path of the next time.

7. The method of claim 6, wherein, The continuing to perform the traffic forwarding by using the SRv6 Policy path if the remaining lifetime of the candidate SRv6 Policy path of the next time is not within the optimal lifetime further includes: detecting a state of the SRv6 Policy path; if the states of the primary SRv6 Policy path and the backup SRv6 Policy path are both DOWN, switching to perform the traffic forwarding by using the candidate SRv6 Policy path of the next time.

8. The method of Claim 5, wherein, The calculating the candidate SRv6 Policy path of the next time that meets the link SLA includes: calculating a primary candidate SRv6 Policy path of the next time and a backup candidate SRv6 Policy path of the next time, and setting corresponding priorities; configuring the primary candidate SRv6 Policy path of the next time with a same BSID as the SRv6 Policy path; the candidate SRv6 Policy path of the next time is associated with an End-SPA, and the backup candidate SRv6 Policy path of the next time remains in an activated state.

9. The method of Claim 6, wherein, The detecting the state of the candidate SRv6 Policy path of the next time includes: The SRv6 Path Verify is used to detect the status of the candidate SRv6 Policy path at the next time.

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