Intersatellite routing method and device for low-orbit constellation network based on BGP protocol

Abstract

The present invention provides a method and device for intersatellite routing of a low-orbit constellation network based on the BGP protocol, wherein the method includes: when determining that a link on-off state change occurs within a forwarding rectangle, further determining whether the link on-off state change will affect the change in the route reachability state from the current satellite node to the destination satellite node within the forwarding rectangle; the forwarding rectangle is formed by the current satellite node and the destination satellite node; if it is determined that it will affect, then the adjacent satellite nodes outside the forwarding rectangle are notified of the change in the route reachability state from the current satellite node to the destination satellite node; if it is determined that it will not affect, then the adjacent satellite nodes outside the forwarding rectangle are not notified of the change in the route reachability state from the current satellite node to the destination satellite node. This scheme can reduce the impact of changes in link on-off states on intersatellite routing of constellation networks.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of satellite communication technology, and in particular to a BGP-based low-orbit constellation network inter-satellite routing method and device. Background Art

[0002] Low earth orbit (LEO) satellite constellations, with their wide coverage and all-weather characteristics, have become the most effective solution to make up for the blind spots in ground network coverage, and are an important part of the future integrated sky, land and sea network. Satellite Internet is generally divided into three parts: constellation network, ground network and satellite terminal. Among them, the constellation network mainly carries inter-satellite interconnection services and realizes the Internet networking of the sky and the earth. Due to the characteristics of high-speed movement of the low-orbit constellation network to the ground, with an average movement speed of 7 to 8 km / s, it basically orbits the earth in about 100 minutes. Therefore, the links between satellites are extremely unstable, and the topological relationship is constantly changing, which brings great challenges to the inter-satellite routing method.

[0003] The links between satellites in the constellation network are extremely unstable. As the satellites periodically orbit the earth, the on-off status of the inter-satellite laser links changes periodically. For example, after a satellite passes through the earth's pole, the co-orbital laser link between satellites needs to be interrupted for a period of time before it can be restored; for another example, in order to prevent the satellite laser link from being affected by the solar eclipse, it also needs to be periodically opened and closed; in addition, as the satellites orbit the earth, the physical distance of the inter-satellite link also changes periodically. These factors of periodic changes in link status will lead to frequent refreshes of the routing of the entire constellation network, which in turn affects the convergence and forwarding performance of the routing.

[0004] How to reduce the impact of changes in link on / off status on inter-satellite routing in constellation networks is an issue that needs to be addressed urgently. Summary of the invention

[0005] The embodiments of the present invention provide a BGP-based low-orbit constellation network inter-satellite routing method and device, which can reduce the impact of changes in link on-off status on constellation network inter-satellite routing.

[0006] In a first aspect, an embodiment of the present invention provides a low-orbit constellation network inter-satellite routing method based on the BGP protocol, which is applied to any satellite node in the low-orbit constellation network. The method includes:

[0007] When determining that a link on / off state change occurs within a forwarding rectangle, further determining whether the link on / off state change will affect a route reachability state change from a current satellite node to a destination satellite node within the forwarding rectangle; the forwarding rectangle is formed by the current satellite node and the destination satellite node;

[0008] If it is determined that it will have an impact, the adjacent satellite nodes outside the forwarding rectangle are notified of the change in the route reachability state from the current satellite node to the destination satellite node; if it is determined that it will not have an impact, the adjacent satellite nodes outside the forwarding rectangle are not notified of the change in the route reachability state from the current satellite node to the destination satellite node.

[0009] In a second aspect, an embodiment of the present invention further provides a low-orbit constellation network inter-satellite routing device based on the BGP protocol, which is applied to any satellite node in the low-orbit constellation network, and the device includes:

[0010] A determination unit is used to further determine whether the change in link connectivity state will affect the change in route reachability state from the current satellite node to the destination satellite node within the forwarding rectangle when it is determined that a link connectivity state change occurs within the forwarding rectangle; the forwarding rectangle is formed by the current satellite node and the destination satellite node; if it is determined that it will affect, the change in route reachability state from the current satellite node to the destination satellite node is notified to the adjacent satellite nodes outside the forwarding rectangle; if it is determined that it will not affect, the change in route reachability state from the current satellite node to the destination satellite node is not notified to the adjacent satellite nodes outside the forwarding rectangle.

[0011] In a third aspect, an embodiment of the present invention further provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method described in any embodiment of this specification is implemented.

[0012] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, enables the computer to execute the method described in any embodiment of this specification.

[0013] The embodiment of the present invention provides a method and device for inter-satellite routing of a low-orbit constellation network based on the BGP protocol. When the current satellite node determines that a link on / off state change occurs within a forwarding rectangle, it does not directly notify the satellite nodes outside the forwarding rectangle of the route reachability state change, but first determines whether the link on / off state change will affect the route reachability state change from the current satellite node to the destination satellite node within the forwarding rectangle. Only when it is determined that it will affect, the adjacent satellite nodes outside the forwarding rectangle are notified of the route reachability state change from the current satellite node to the destination satellite node. It can be seen that this solution can reduce the impact of link on / off state changes on the inter-satellite routing of the constellation network. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 This is a flow chart of an inter-satellite routing method for a low-orbit constellation network based on the BGP protocol provided by an embodiment of the present invention;

[0016] Figure 2 is a constellation network schematic diagram provided by an embodiment of the present invention;

[0017] Figure 3 is a hardware architecture diagram of an electronic device provided by an embodiment of the present invention;

[0018] Figure 4 This is a structural diagram of an inter-satellite routing device for a low-orbit constellation network based on the BGP protocol provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0020] In the invention patent with the patent publication number of "CN116708271A" and the patent name of "Intersatellite Routing Method and Device for Low-Earth Orbit Constellation Network", if the OSPF protocol is used to learn and calculate the route, although the forwarding rectangle determined by the two route attribute parameters of the extended north-south vertical hop count V-Hops and the east-west horizontal hop count H-hops is used to calculate the optimal route to avoid the performance bottleneck of OSPF calculation, since the OSPF protocol is a link state protocol, the frequent changes in the on-off status of the links between satellites will lead to frequent refreshes of routing messages, which will have a great impact on the convergence of satellite routing and the overhead of the satellite system; if the BGP protocol is used, since the BGP protocol will only refresh the routing messages when the optimal route changes, the frequent changes in the on-off status of the links between satellites will have a smaller impact on the routing messages than the OSPF protocol, but the frequent changes in the on-off status of the links may also lead to frequent refreshes of routing messages. When using the BGP protocol, how to further reduce the impact of the changes in the on-off status of the links on the frequent refreshes of the intersatellite routing in the constellation network has become an urgent problem to be solved.

[0021] The inventive concept of the present invention is that: based on the forwarding rectangle concept, if a link on / off state change occurs within the forwarding rectangle, and if the change does not affect the route reachability state change from the current satellite node to the destination satellite node within the forwarding rectangle, there is no need to send a notification of the route reachability state change to the satellite nodes outside the forwarding rectangle, thereby reducing the frequent refresh of inter-satellite routing in the constellation network, and further reducing the impact of link on / off state changes on the frequent refresh of inter-satellite routing in the constellation network.

[0022] The specific implementation of the above concept is described below.

[0023] Please refer to Figure 1 The embodiment of the present invention provides a low-orbit constellation network inter-satellite routing method based on the BGP protocol, which is applied to any satellite node in the low-orbit constellation network. The method includes:

[0024] Step 100, when it is determined that a link connection state change occurs within a forwarding rectangle, further determine whether the link connection state change will affect a route reachability state change from a current satellite node to a destination satellite node within the forwarding rectangle; the forwarding rectangle is formed by the current satellite node and the destination satellite node; if it is determined that it will affect, the route reachability state change from the current satellite node to the destination satellite node is notified to adjacent satellite nodes outside the forwarding rectangle; if it is determined that it will not affect, the route reachability state change from the current satellite node to the destination satellite node is not notified to adjacent satellite nodes outside the forwarding rectangle.

[0025] In the embodiment of the present invention, when the current satellite node determines that a link connection state change occurs within the forwarding rectangle, it does not directly notify the satellite nodes outside the forwarding rectangle of the route reachability state change, but first determines whether the link connection state change will affect the route reachability state change from the current satellite node to the destination satellite node within the forwarding rectangle. Only when it is determined that it will affect, the adjacent satellite nodes outside the forwarding rectangle are notified of the route reachability state change from the current satellite node to the destination satellite node. It can be seen that this solution can reduce the impact of link connection state changes on the inter-satellite routing of the constellation network.

[0026] Described below Figure 1 How the steps shown are performed.

[0027] In an embodiment of the present invention, a forwarding rectangle method can be used to determine an optimal route in a constellation network, and the forwarding rectangle is formed by a current satellite node and a destination satellite node. Specifically, the route of the current satellite node and the destination satellite node includes the number of north-south vertical hops (V-hops) and the number of east-west horizontal hops (H-hops) from the current satellite node to the destination satellite node, and the two vertices of the diagonal of the forwarding rectangle are the current satellite node and the destination satellite node, respectively, and the number of north-south vertical hops and the number of east-west horizontal hops from the current satellite node to the destination satellite node are respectively the two side lengths of the forwarding rectangle.

[0028] Please refer to Figure 2 , is a schematic diagram of a constellation network. In this constellation network, taking the current satellite node S and the destination satellite node D as examples, the area in the dotted box is the area of ​​the forwarding rectangle. Among them, satellite node E and satellite node G are both adjacent satellite nodes of satellite node S within the forwarding rectangle, and satellite node B and satellite node J are both adjacent satellite nodes of satellite node S outside the forwarding rectangle.

[0029] In the embodiment of the present invention, the current satellite node S determines that a link on / off state change occurs within the forwarding rectangle mainly includes:

[0030] The first method: the link on / off state change is the on / off state change of the non-directly connected link of the current satellite node on the path between the current satellite node and the destination satellite node. The current satellite node can determine the link on / off state change in the forwarding rectangle based on the routing message sent by the adjacent satellite node in the forwarding rectangle.

[0031] The second method: the link on-off status change is the on-off status change of the direct link of the current satellite node on the path between the current satellite node and the destination satellite node. The current satellite node can determine the on-off status of the laser link based on its own monitoring of the adjacent satellite nodes in the forwarding rectangle.

[0032] In the first mode, if an adjacent satellite node in a forwarding rectangle determines that the link on / off state between itself and the destination satellite node has changed, and if the change will affect the change in the route reachability state from the adjacent satellite node to the destination satellite node in the forwarding rectangle (the forwarding rectangle formed by the adjacent satellite node and the destination satellite node), the change in the route reachability state between the adjacent satellite node and the destination satellite node will be notified to the current satellite node, so that the current satellite node can determine that the link on / off state has changed in the forwarding rectangle (the forwarding rectangle formed by the current satellite node and the destination satellite node) according to the change in the route reachability state. For example, if the link between satellite node E and destination satellite node D changes from on to off, or from off to on, the change in the route reachability state will be notified to satellite node S.

[0033] In the second method, if the current satellite node monitors that the link status of the laser link with the adjacent satellite node E has changed, for example, the link between satellite node S and satellite node E changes from on to off, or from off to on, then it can also be determined that a link on / off status change has occurred within the forwarding rectangle.

[0034] Regardless of which of the above methods determines that a link connection state change occurs within the forwarding rectangle, it is necessary to further determine whether the link connection state change will affect the route reachability state change from the current satellite node to the destination satellite node within the forwarding rectangle. Specifically, it can be determined in the following manner: determine whether there are other routes from the current satellite node to the destination satellite node in the forwarding rectangle except for the route where the link connection state change occurs. If so, it is determined that there will be no impact; if not, it is determined that there will be an impact.

[0035] Continue with Figure 2 For example, assuming that the route with the link connection and disconnection status change is SED, then it can be determined whether there are other routes in the forwarding rectangle, and the other route is SGD. If the other route SGD exists, that is, the link connection and disconnection status of the other route is connected, no matter whether the link connection and disconnection status of the route SED changes from disconnected to connected, or from connected to disconnected, it will not affect the change of the route reachability status from the current satellite node S to the destination satellite node D. If the other route SGD does not exist, that is, the link connection and disconnection status of the other route is disconnected, then if the link connection and disconnection status of the route SED changes from disconnected to connected, then the route reachability status of the current satellite node S to the destination satellite node D will also change from disconnected to connected. Similarly, if the link connection and disconnection status of the route SED changes from connected to disconnected, then the route reachability status of the current satellite node S to the destination satellite node D will also change from connected to disconnected. It can be seen that it will affect the change of the route reachability status from the current satellite node S to the destination satellite node D.

[0036] In summary, if there are other routes from the current satellite node to the destination satellite node in the forwarding rectangle except for the route where the link connection and disconnection status changes, that is, the route in the forwarding rectangle where the link connection and disconnection status changes is the following case A or case B, then it can be determined that it will not affect:

[0037] Case A: Before the link status changes, the forwarding rectangle includes two routes, and one route has a link status change from connected to disconnected.

[0038] Case B: Before the link status changes, the forwarding rectangle includes one route, and the link status of another route changes from disconnected to connected;

[0039] If there is no other route from the current satellite node to the destination satellite node in the forwarding rectangle except the route where the link connection and disconnection status changes, that is, the route in the forwarding rectangle where the link connection and disconnection status changes is the following case C or case D, then it can be determined that it will affect:

[0040] Case C: Before the link status changes, the forwarding rectangle includes a route. The link status of the route changes from connected to disconnected. After the link status changes, the route in the forwarding rectangle is deleted.

[0041] Case D: Before the link status changes, there is no route in the forwarding rectangle. The link status changes from off to on. At this time, a new route is added in the forwarding rectangle after the link status changes.

[0042] It can be understood that if there are two routes from the current satellite node to the destination satellite node in the forwarding rectangle, if one of the routes fails, there is no need to notify the adjacent satellite nodes outside the forwarding rectangle to cancel the route. It is only necessary to switch the route from the current satellite node to the destination satellite node locally to another route. Only when both routes fail, the adjacent satellite nodes outside the forwarding rectangle are notified to cancel the route. If there is only one route from the current satellite node to the destination satellite node in the forwarding rectangle, and the link on / off state of the other route changes from off to on, there is no need to send a notification to the adjacent satellite nodes outside the forwarding rectangle. It is only necessary for the current satellite node to reselect the optimal route from the two routes from the current satellite node to the destination satellite node to perform route switching locally. It can be seen that in the normal operation scenario, the link on / off state between the satellites in the constellation network will change frequently and periodically, but the resulting routing selection result will only cause the local route switching of the satellite node, and will not affect the routes within the entire constellation network. That is to say, if the link connection and disconnection status changes within the forwarding rectangle do not affect the route reachability status changes from the current satellite node to the destination satellite node within the forwarding rectangle, the adjacent satellite nodes outside the forwarding rectangle do not need to perceive the route reachability status changes within the forwarding rectangle.

[0043] In one embodiment of the present invention, regardless of whether the link connection and disconnection status change occurring in the forwarding rectangle will affect the route reachability status change from the current satellite node to the destination satellite node in the forwarding rectangle, the current satellite node needs to process the locally stored route based on the link connection and disconnection status change occurring in the forwarding rectangle. Specifically, the link connection and disconnection status change includes two situations:

[0044] The first case: the link status changes from off to on;

[0045] The second situation: the link status changes from on to off.

[0046] In the first case, the link status changes from disconnected to connected, and the route for the link status change is sent by the adjacent satellite node of the current satellite node in the forwarding rectangle, and the route carries the address of the destination satellite node, the AS value of the adjacent satellite node, and the number of vertical hops from the adjacent satellite node to the destination satellite node in the north-south direction and the number of horizontal hops from the east-west direction. The route is a BGP route.

[0047] In the embodiment of the present invention, before describing the process of the current satellite node processing the locally stored route, the AS value carried by the route is described first.

[0048] The AS path (AS_PATH) attribute of BGP routing is a recognized mandatory attribute. The AS path attribute is used to indicate which satellite nodes the routing update information passes through. Its main function is to ensure that there is no loop between ASs. At the same time, the AS path attribute can also be used for routing selection and filtering. When other factors are the same, the BGP protocol will give priority to the route with a shorter AS path as the optimal route. Figure 2 Taking the route DES as an example, the destination satellite node D sends the route to the satellite node E, and the satellite node E sends the route to the satellite node S. Then in the traditional way, the AS path attribute of the route received by the satellite node S is the AS value of the satellite node E-the AS value of the satellite node D, indicating that the route is sent from the satellite node D and passes through the satellite node E. In the embodiment of the present invention, the BGP route carries the number of hops in the north-south vertical direction and the number of hops in the east-west horizontal direction. The route calculated by using these two hops according to the forwarding rectangle must be loop-free, so the anti-loop function of the AS path attribute is not required, and the forwarding rectangle algorithm does not need to rely on the routing and filtering functions of the AS path attribute. Therefore, in the embodiment of the present invention, the AS path attribute carried by the BGP route is optimized, that is, when the satellite node sends the BGP route to the adjacent satellite node, the AS value of its own satellite node is directly covered by the AS path attribute. In other words, the AS path attribute in the BGP route only includes one AS value, that is, the AS value of the satellite node that sends the route.

[0049] Based on the above description, the processing process of the local stored routes by the current satellite node is described below.

[0050] Specifically, the current satellite node may process the locally stored route by: calculating the north-south vertical hop count and the east-west horizontal hop count from the current satellite node to the destination satellite node according to the north-south vertical hop count and the east-west horizontal hop count from the adjacent satellite node to the destination satellite node carried by the route with the link on / off status change, and determining whether the calculated hop counts are both 0, if so, indicating that a loop has occurred in the route, then the route is discarded; otherwise, the route is stored; the stored route includes: the address of the destination satellite node, the AS value of the adjacent satellite node that sent the route, and the north-south vertical hop count and the east-west horizontal hop count from the current satellite node to the destination satellite node. In one implementation, the stored route may be in the form of: IP (V-hops, H-hops / AS).

[0051] In an embodiment of the present invention, the number of north-south vertical hops and the number of east-west horizontal hops from the current satellite node to the destination satellite node can be calculated based on the definitions of the number of north-south vertical hops and the number of east-west horizontal hops and the positional relationship between the current satellite node and the adjacent satellite node that sent the route.

[0052] The number of vertical north-south hops (V-hops) is used to characterize the number of hops required to forward from the current satellite node to the destination satellite node in the vertical direction (i.e., north-south direction). The positive and negative values ​​of V-hops can be defined to characterize the relationship between the routing forwarding direction and the satellite movement direction. In one implementation, it can be defined that when the direction from the destination satellite node to the current satellite node is consistent with the satellite movement direction, V-hops is a positive number, otherwise it is a negative number.

[0053] Then, the calculation method of the number of north-south vertical hops from the current satellite node to the destination satellite node is: if the adjacent satellite node is in the same orbit as the current satellite node, determine whether the direction from the adjacent satellite node to the current satellite node is the same as the direction of satellite movement; if so, add 1 to the number of north-south vertical hops from the adjacent satellite node to the destination satellite node; if not, subtract 1 from the number of north-south vertical hops from the adjacent satellite node to the destination satellite node.

[0054] The number of horizontal hops (H-hops) in the east-west direction is used to represent the number of hops required to forward from the current satellite node to the destination satellite node in the horizontal direction (that is, the east-west direction). Similarly, when the destination satellite node is east of the current satellite node, H-hops is a negative number, otherwise it is a positive number.

[0055] Then the calculation method of the number of east-west horizontal hops from the current satellite node to the destination satellite node is: if the adjacent satellite node crosses the track with the current satellite node, determine whether the adjacent satellite node is located to the east of the current satellite node. If so, reduce the number of east-west horizontal hops from the adjacent satellite node to the destination satellite node by 1; if not, increase the number of east-west horizontal hops from the adjacent satellite node to the destination satellite node by 1.

[0056] It can be understood that if the calculated north-south vertical hop count and east-west horizontal hop count from the current satellite node to the destination satellite node are both 0, it indicates that the route is sent by the current satellite node, so the route can be directly discarded. If it is not sent by the current satellite node, the route needs to be stored. Take the example that the current satellite node S receives routes sent by satellite nodes E and G respectively, and the address of the destination satellite node D is 1.1.1.1, then the route sent by satellite node E is 1.1.1.1 (0, 1 / E), and the route sent by satellite node G is 1.1.1.1 (-1, 0 / G). The current satellite node S stores two routes, one is 1.1.1.1 (-1, 1 / E), and the other is 1.1.1.1 (-1, 1 / G).

[0057] It should be noted that the prefix address information of the route is carried by the Network Layer Reachability Information (NLRI) of the BGP routing message. The AS value, the number of hops in the north-south vertical direction, and the number of hops in the east-west horizontal direction are all carried by the path attributes (Path Attributes) of the BGP routing message. The AS value is in the AS path attribute, and the number of hops in the north-south vertical direction and the number of hops in the east-west horizontal direction are in the HVHR extended community attribute.

[0058] In the second case, if the link connection state changes from on to off, the current satellite node's processing of the locally stored route may include: deleting the stored route of the link connection state change. It can be understood that before the link connection state changes, the current satellite node has the route stored locally. If the link connection state changes to off, the route needs to be deleted. Specifically, the locally stored route may include the address of the destination satellite node and the AS value of the adjacent satellite node of the link connection state change, and the route may be deleted. For example, if the route of the link connection state change is SED, then the locally stored 1.1.1.1(-1,1 / E) is deleted.

[0059] The above completes the description of the current satellite node processing the locally stored routes based on the link on / off status change within the forwarding rectangle.

[0060] Furthermore, when the link connection and disconnection state changes correspond to the above different situations, the modes of notifying the adjacent satellite nodes outside the forwarding rectangle of the change in the route reachability state from the current satellite node to the destination satellite node are also different. The notification modes for the above two different situations are described below.

[0061] In the first case, the notifying the adjacent satellite nodes outside the forwarding rectangle of the change in the route reachability state from the current satellite node to the destination satellite node specifically includes:

[0062] Determine whether the number of routes with link status changes is two. If so, select one of the two routes, replace the AS value in the selected route with the AS value of the current satellite node, and send the route with the replaced AS value to the adjacent satellite node outside the forwarding rectangle; if not, replace the AS value in the route with the link on / off status change with the AS value of the current satellite node, and send the route with the replaced AS value to the adjacent satellite node outside the forwarding rectangle.

[0063] The current satellite node includes two adjacent satellite nodes in the forwarding rectangle, that is, the current satellite node to the destination satellite node can include two routes in the forwarding rectangle, so the link on / off state changes may occur in both routes. If the link on / off state changes occur in both routes, and the link on / off state changes are all from off to on, then when sending the route from the current satellite node to the destination satellite node to the adjacent satellite node outside the forwarding rectangle, not all of the two routes are sent, but one route is selected from the two routes for sending, and the one route selected from the two routes can be any route or the optimal route.

[0064] Continue with Figure 2 As an example, assume that route SED is selected as the optimal route, and the route is 1.1.1.1 (-1, 1 / E). The AS value in the route is replaced with the AS value of the current satellite node S, and the resulting route 1.1.1.1 (-1, 1 / S) is sent to adjacent satellite nodes B and J outside the forwarding rectangle.

[0065] It should be noted that since the AS path attribute in the route only includes the AS value of the route, when selecting a route, no matter which route is selected, the route sent out is the same. For example, if the route SGD is selected, the route is 1.1.1.1 (-1, 1 / G), the AS value in the route is replaced with the AS value of the current satellite node S, and the resulting route 1.1.1.1 (-1, 1 / S) is sent to the adjacent satellite nodes B and J outside the forwarding rectangle. It can be seen that the routes sent out by the selected route SED are the same. Therefore, each satellite node can merge two routes sent from different AS paths in its respective forwarding rectangle into one route and publish it to the adjacent satellite nodes outside the forwarding rectangle, thereby reducing the total number of routes in the entire constellation network.

[0066] Furthermore, if it is determined that the number of routes with link status changes is one, the AS value in the route with link status changes can be directly replaced with the AS value of the current satellite node, and the route with replaced AS value is sent to the adjacent satellite node outside the forwarding rectangle.

[0067] Then it can be determined that the route sent to the adjacent satellite node outside the forwarding rectangle includes: the address of the target satellite node, the AS value of the current satellite node, the number of north-south vertical hops and the number of east-west horizontal hops from the current satellite node to the target satellite node.

[0068] In the second case, the notifying the adjacent satellite nodes outside the forwarding rectangle of the change in the route reachability state from the current satellite node to the destination satellite node specifically includes:

[0069] A notification of canceling the route from the current satellite node to the destination satellite node is sent to the adjacent satellite node outside the forwarding rectangle, so that the adjacent satellite node deletes the stored route including the address of the destination satellite node and the AS value of the current satellite node.

[0070] Continue with Figure 2 Take an example to illustrate that the current satellite node S sends notifications to the adjacent satellite nodes B and J outside the forwarding rectangle to cancel the route from the current satellite node to the destination satellite node. Satellite node B will delete the locally stored 1.1.1.1(-1,2 / S), and satellite node J will delete the locally stored 1.1.1.1(-2,1 / S).

[0071] In the embodiment of the present invention, by optimizing the AS path attributes carried by the BGP route, the impact of the on / off state change of the inter-satellite laser link on the inter-satellite routing of the constellation network can be reduced. At the same time, the two routes that may have been sent outside the forwarding rectangle are changed to only one route, thereby eliminating redundant inter-satellite routes, reducing the total number of inter-satellite routes of the constellation network, making the routing learning of the entire constellation network more efficient and stable, and greatly improving the efficiency and reliability of the transmission of inter-satellite carried services.

[0072] like Figure 3 , Figure 4 As shown, an embodiment of the present invention provides an inter-satellite routing device for a low-orbit constellation network. The device embodiment can be implemented by software, or by hardware or a combination of software and hardware. From the hardware level, Figure 3 As shown, it is a hardware architecture diagram of an electronic device where an inter-satellite routing device of a low-orbit constellation network provided by an embodiment of the present invention is located, except Figure 3 In addition to the processor, memory, network interface, and non-volatile memory shown, the electronic device in the embodiment may also include other hardware, such as a forwarding chip responsible for processing messages, etc. Taking software implementation as an example, Figure 4 As shown, as a device in a logical sense, the CPU of the electronic device in which it is located reads the corresponding computer program in the non-volatile memory into the memory and runs it. This embodiment provides an inter-satellite routing device for a low-orbit constellation network, which is applied to any satellite node in the low-orbit constellation network, and the device includes:

[0073] The determination unit 401 is used to further determine whether the change in the link connectivity state will affect the change in the route reachability state from the current satellite node to the destination satellite node within the forwarding rectangle when it is determined that a link connectivity state change occurs within the forwarding rectangle; the forwarding rectangle is formed by the current satellite node and the destination satellite node; if it is determined that it will affect, the change in the route reachability state from the current satellite node to the destination satellite node is notified to the adjacent satellite nodes outside the forwarding rectangle; if it is determined that it will not affect, the change in the route reachability state from the current satellite node to the destination satellite node is not notified to the adjacent satellite nodes outside the forwarding rectangle.

[0074] In one embodiment of the present invention, when the determination unit executes the determination of whether the change in the link on / off status will affect the change in the route reachability status from the current satellite node to the destination satellite node within the forwarding rectangle, it specifically includes: determining whether there are other routes from the current satellite node to the destination satellite node within the forwarding rectangle except the route where the link on / off status change occurs; if so, determining that there will be no impact; if not, determining that there will be an impact.

[0075] In one embodiment of the present invention, the link on / off state changes from off to on; the route for the link on / off state change is sent by an adjacent satellite node of the current satellite node in the forwarding rectangle; the route carries the address of the destination satellite node, the AS value of the adjacent satellite node, the number of hops in the north-south vertical direction and the number of hops in the east-west horizontal direction from the adjacent satellite node to the destination satellite node;

[0076] The determination unit is also used to: calculate the north-south vertical hop count and the east-west horizontal hop count from the current satellite node to the destination satellite node according to the north-south vertical hop count and the east-west horizontal hop count from the adjacent satellite node to the destination satellite node carried by the route where the link on / off state changes, and determine whether the calculated hop counts are all 0. If so, discard the route; otherwise, store the route; the stored route includes: the address of the destination satellite node, the AS value of the adjacent satellite node that sent the route, and the north-south vertical hop count and the east-west horizontal hop count from the current satellite node to the destination satellite node.

[0077] In one embodiment of the present invention, when the determination unit executes the notification of the change in the route reachability status from the current satellite node to the destination satellite node to the adjacent satellite nodes outside the forwarding rectangle, it specifically includes: determining whether the number of routes where the link status change occurs is two, and if so, selecting one route from the two routes, replacing the AS value in the selected route with the AS value of the current satellite node, and sending the route with the replaced AS value to the adjacent satellite nodes outside the forwarding rectangle; if not, replacing the AS value in the route where the link on / off status change occurs with the AS value of the current satellite node, and sending the route with the replaced AS value to the adjacent satellite nodes outside the forwarding rectangle.

[0078] In one embodiment of the present invention, one of the two routes is selected as the optimal route.

[0079] In one embodiment of the present invention, the link on / off state change is from on to off;

[0080] When the determination unit executes the process of notifying the adjacent satellite nodes outside the forwarding rectangle of the change in the route reachability status from the current satellite node to the destination satellite node, it specifically includes: sending a notification to the adjacent satellite nodes outside the forwarding rectangle to revoke the route from the current satellite node to the destination satellite node, so that the adjacent satellite node deletes the stored route that includes the address of the destination satellite node and the AS value of the current satellite node.

[0081] It is to be understood that the structure illustrated in the embodiment of the present invention does not constitute a specific limitation on an inter-satellite routing device for a low-orbit constellation network based on the BGP protocol. In other embodiments of the present invention, an inter-satellite routing device for a low-orbit constellation network based on the BGP protocol may include more or fewer components than shown in the figure, or combine certain components, or split certain components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0082] The information interaction, execution process and other contents between the modules in the above-mentioned device are based on the same concept as the embodiment of the method of the present invention. For the specific contents, please refer to the description in the embodiment of the method of the present invention, and no further description is given here.

[0083] An embodiment of the present invention further provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, a low-orbit constellation network inter-satellite routing method based on the BGP protocol in any embodiment of the present invention is implemented.

[0084] An embodiment of the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the processor executes a low-orbit constellation network inter-satellite routing method based on the BGP protocol in any embodiment of the present invention.

[0085] Specifically, a system or device equipped with a storage medium can be provided, on which software program code that implements the functions of any of the above-mentioned embodiments is stored, and a computer (or CPU or MPU) of the system or device can be enabled to read and execute the program code stored in the storage medium.

[0086] In this case, the program code itself read from the storage medium can realize the function of any one of the above-mentioned embodiments, and thus the program code and the storage medium storing the program code constitute a part of the present invention.

[0087] The storage medium embodiments for providing the program code include a floppy disk, a hard disk, a magneto-optical disk, an optical disk (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), a magnetic tape, a non-volatile memory card, and a ROM. Alternatively, the program code can be downloaded from a server computer by a communication network.

[0088] In addition, it should be clear that the functions of any of the above embodiments can be implemented not only by executing the program code read by the computer, but also by enabling an operating system operating on the computer to complete part or all of the actual operations based on instructions from the program code.

[0089] In addition, it can be understood that the program code read from the storage medium is written to a memory provided in an expansion board inserted into the computer or to a memory provided in an expansion module connected to the computer, and then based on the instructions of the program code, a CPU installed on the expansion board or expansion module is enabled to perform part or all of the actual operations, thereby realizing the functions of any of the above-mentioned embodiments.

[0090] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical factors in the process, method, article or device including the elements.

[0091] A person of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiments; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk, etc., various media that can store program codes.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-orbit constellation network inter-satellite routing method based on the BGP protocol, characterized in that: Applied to any satellite node in a low-orbit constellation network, the method comprises: When determining that a link on / off state change occurs within a forwarding rectangle, further determining whether the link on / off state change will affect a route reachability state change from a current satellite node to a destination satellite node within the forwarding rectangle; the forwarding rectangle is formed by a current satellite node and a destination satellite node; two vertices of the diagonal corners of the forwarding rectangle are the current satellite node and the destination satellite node, respectively; and the number of hops in the north-south vertical direction and the number of hops in the east-west horizontal direction from the current satellite node to the destination satellite node are respectively the two side lengths of the forwarding rectangle; If it is determined that there will be an impact, the adjacent satellite nodes outside the forwarding rectangle are notified of the change in the route reachability state from the current satellite node to the destination satellite node; if it is determined that there will be no impact, the adjacent satellite nodes outside the forwarding rectangle are not notified of the change in the route reachability state from the current satellite node to the destination satellite node; The determination of whether the change in the link on / off state will affect the change in the route reachability state from the current satellite node to the destination satellite node within the forwarding rectangle includes: determining whether there are other routes from the current satellite node to the destination satellite node within the forwarding rectangle except the route where the link on / off state change occurs; if so, determining that there will be no impact; if not, determining that there will be an impact.

2. The method according to claim 1, characterized in that The link on / off state changes from off to on; the route where the link on / off state changes is sent by an adjacent satellite node of the current satellite node in the forwarding rectangle; The route carries the address of the destination satellite node, the AS value of the adjacent satellite node, the number of hops in the north-south vertical direction and the number of hops in the east-west horizontal direction from the adjacent satellite node to the destination satellite node; Before determining whether the link on / off state change will affect the route reachability state change from the current satellite node to the destination satellite node within the forwarding rectangle, the method further includes: According to the number of north-south vertical hops and east-west horizontal hops from the adjacent satellite node to the destination satellite node carried by the route with the link on / off status change, the number of north-south vertical hops and east-west horizontal hops from the current satellite node to the destination satellite node are calculated, and it is determined whether the calculated hops are all 0. If so, the route is discarded; otherwise, the route is stored; the stored route includes: the address of the destination satellite node, the AS value of the adjacent satellite node that sent the route, and the number of north-south vertical hops and east-west horizontal hops from the current satellite node to the destination satellite node.

3. The method according to claim 2, characterized in that Notifying adjacent satellite nodes outside the forwarding rectangle of a change in the route reachability state from the current satellite node to the destination satellite node includes: Determine whether the number of routes where the link connection and disconnection status changes is two. If so, select one of the two routes, replace the AS value in the selected route with the AS value of the current satellite node, and send the route with the replaced AS value to the adjacent satellite node outside the forwarding rectangle; if not, replace the AS value in the route where the link connection and disconnection status changes with the AS value of the current satellite node, and send the route with the replaced AS value to the adjacent satellite node outside the forwarding rectangle.

4. The method according to claim 3, characterized in that The route selected from the two routes is the optimal route.

5. The method according to any one of claims 1 to 4, characterized in that: The link on / off state changes from on to off; Notifying adjacent satellite nodes outside the forwarding rectangle of a change in the route reachability state from the current satellite node to the destination satellite node includes: A notification of canceling the route from the current satellite node to the destination satellite node is sent to the adjacent satellite node outside the forwarding rectangle, so that the adjacent satellite node deletes the stored route including the address of the destination satellite node and the AS value of the current satellite node.

6. A low-orbit constellation network inter-satellite routing device based on the BGP protocol, characterized in that: Applied to any satellite node in a low-orbit constellation network, the device comprises: A determination unit is used to further determine whether the link on / off state change will affect the route reachability state change from the current satellite node to the destination satellite node within the forwarding rectangle when it is determined that a link on / off state change occurs within the forwarding rectangle; the forwarding rectangle is formed by the current satellite node and the destination satellite node; if it is determined that it will affect, the route reachability state change from the current satellite node to the destination satellite node is notified to the adjacent satellite nodes outside the forwarding rectangle; if it is determined that it will not affect, the route reachability state change from the current satellite node to the destination satellite node is not notified to the adjacent satellite nodes outside the forwarding rectangle; the two diagonal vertices of the forwarding rectangle are the current satellite node and the destination satellite node, respectively, and the number of hops in the north-south vertical direction and the number of hops in the east-west horizontal direction from the current satellite node to the destination satellite node are respectively the two side lengths of the forwarding rectangle; When the determination unit is executing the determination of whether the change in the link on / off status will affect the change in the route reachability status from the current satellite node to the destination satellite node within the forwarding rectangle, it specifically includes: determining whether there are other routes from the current satellite node to the destination satellite node within the forwarding rectangle except the route where the link on / off status change occurs; if so, determining that there will be no impact; if not, determining that there will be an impact.

7. The device according to claim 6, characterized in that The link on / off state changes from off to on; the route where the link on / off state changes is sent by an adjacent satellite node of the current satellite node in the forwarding rectangle; The route carries the address of the destination satellite node, the AS value of the adjacent satellite node, the number of hops in the north-south vertical direction and the number of hops in the east-west horizontal direction from the adjacent satellite node to the destination satellite node; The determining unit is further used to: calculate the number of north-south vertical hops and the number of east-west horizontal hops from the current satellite node to the destination satellite node according to the number of north-south vertical hops and the number of east-west horizontal hops from the adjacent satellite node to the destination satellite node carried by the route where the link on / off state changes, and determine whether the calculated hop numbers are all 0, and if so, discard the route; Otherwise, store the route; The stored route includes: the address of the destination satellite node, the AS value of the adjacent satellite node that sent the route, the number of north-south vertical hops and the number of east-west horizontal hops from the current satellite node to the destination satellite node.

8. The device according to claim 7, characterized in that When the determination unit executes the notification of the change in the route reachability status from the current satellite node to the destination satellite node to the adjacent satellite nodes outside the forwarding rectangle, it specifically includes: determining whether the number of routes where the link status change occurs is two; if so, selecting one route from the two routes, replacing the AS value in the selected route with the AS value of the current satellite node, and sending the route with the replaced AS value to the adjacent satellite nodes outside the forwarding rectangle; if not, replacing the AS value in the route where the link on / off status change occurs with the AS value of the current satellite node, and sending the route with the replaced AS value to the adjacent satellite nodes outside the forwarding rectangle.

9. The device according to claim 8, characterized in that The route selected from the two routes is the optimal route.

10. The device according to any one of claims 6 to 9, characterized in that: The link on / off state changes from on to off; When the determination unit executes notifying the adjacent satellite nodes outside the forwarding rectangle of the change in the route reachability status from the current satellite node to the destination satellite node, it specifically includes: sending a notification to the adjacent satellite nodes outside the forwarding rectangle to revoke the route from the current satellite node to the destination satellite node, so that the adjacent satellite node deletes the stored route including the address of the destination satellite node and the AS value of the current satellite node.

11. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method according to any one of claims 1 to 5 is implemented.

12. A computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to execute the method according to any one of claims 1 to 5.

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