A Time-Varying Routing Method and System for Satellite Internet Based on Predictive Topology

Abstract

This invention discloses a time-varying routing method and system for satellite internet, primarily addressing the problems of existing satellite network routing methods being unable to support high-quality satellite communication, frequent topology changes, and heavy information communication load between satellites. The scheme includes: initializing the orbital parameters and inter-satellite link set of satellite nodes; obtaining a link connectivity timetable through simulation and sending it from the ground station to the satellite nodes; generating topology prediction messages based on the link connectivity timetable, determining the message transmission time based on the difference between the link change time and the routing control message transmission time, and flooding the messages within a defined area; upon receiving the messages, parsing the link information, calculating virtual routes, arranging the route update order of satellite nodes, replacing the routing table with the virtual routing table at the link change time, and distributing the routes to the underlying network layer. This invention effectively reduces network transmission load, lowers the probability of outdated routes and packet loss, and can be used for establishing satellite internet, ensuring communication quality between satellites.

Description

Technical Field

[0001] This invention belongs to the field of communication technology, and specifically relates to a calculation method and system for time-varying routes in satellite networks, which can be used to establish satellite internet and ensure the communication quality between satellites. Background Technology

[0002] Satellite internet is a new type of network capable of providing broadband internet access and other communication services to ground and air terminals. Routing algorithms are a crucial component of satellite communication; efficient routing calculations can reduce the load on satellite nodes and improve service quality.

[0003] Traditional link-state-based routing is a dynamic routing method that primarily updates the network topology by dynamically sensing changes in the state of each link in the network in real time. In this method, satellite nodes periodically sense the link state and flood this information, broadcasting the link state to all nodes in the network to ensure that each node receives the latest network topology information. While this method can effectively respond to changes in network topology and adjust routing strategies promptly, it also has some potential problems, particularly the risk of packet loss during data packet transmission.

[0004] Domain-based link-state flooding is a strategy to optimize traditional link-state routing methods. It divides the network into multiple regions, limiting the flooding scope of link-state information. When a node in the network detects a link interruption or reconnection, only nodes within the domain where the topology has changed will update and propagate the link state. This mechanism effectively reduces network load and avoids the heavy burden of network-wide flooding. However, this method still carries a certain risk of packet loss during data transmission and introduces latency in large-scale networks, negatively impacting network real-time performance.

[0005] Patent document CN118870460A discloses a distributed mobility management method and system for satellite internet. This method uses a VIP and subVIP management mechanism to hide satellite mobility. Older satellites synchronize connection management information and satellite routes of online users to newer satellites in real time, allowing users to maintain the same IP address before and after satellite handover, effectively reducing online latency for mobile users and signaling overhead during satellite handover. However, this method does not consider the impact of natural factors such as solar outages on the satellite network topology. When satellite nodes encounter these factors during operation, it can lead to outdated routes and packet loss, affecting the quality of service of the satellite network.

[0006] Patent document CN1905512A discloses a monitoring and analysis system for the OSPF routing protocol on the Internet, which consists of a management node and one or more monitoring nodes distributed in various ASs within the monitored network. This method performs routing monitoring with minimal impact on the network and aggregates routing change information within various areas obtained by multiple monitoring nodes, expanding the system's monitoring scope and supporting routing performance monitoring of large, complex, multi-area networks. However, this method primarily focuses on monitoring and analyzing the performance of the Internet routing protocol and does not completely solve the problems of quality of service and excessive transmission load in satellite networks. Summary of the Invention

[0007] The purpose of this invention is to address the above-mentioned problems by proposing a time-varying routing method and system for satellite internet based on predictive topology. This method fully considers the time-varying and predictable nature of network topology in large-scale satellite internet scenarios, improves satellite resource utilization, effectively reduces latency caused by link changes and sudden factors, and improves the service quality of satellite internet.

[0008] To achieve the above objectives, the technical solution of the present invention includes: a time-varying routing method for satellite internet, a time-varying routing system for satellite internet, an electronic device, and a readable medium, wherein:

[0009] 1. A time-varying routing method for satellite internet, characterized in that it includes:

[0010] (1) Initialize the satellite nodes, initialize the topology prediction message waiting sequence to be sent to be empty, initialize the message processing queue to be empty, and set the topology prediction message sending threshold value to T. threshold Initialize the orbital parameters of the satellite node, and calculate the angular velocity ω, orbital period T, and true anomaly angle θ of the satellite node. t and spatial location (x) t y t , z t );

[0011] (2) Initialize the inter-satellite link set of the satellite nodes. The ground station uses the inter-satellite link set {(l i cost i S i ,sj)}, the angular velocity ω of the satellite node, the orbital period T, and the true anomaly angle θ t and spatial location (x) t y t , z t The satellite link connection and disconnection timetable is obtained through STK simulation using the satellite toolkit, and then the link connection and disconnection timetable is sent to the satellite node.

[0012] (3) After receiving the link connection and disconnection timetable, the satellite node generates a topology prediction message, which includes the link change time, link change status, link cost value, link start node and destination node information;

[0013] (4) Obtain the routing control message transmission time from the system clock of the satellite, obtain the link change time from the topology prediction message, calculate the difference between the two to determine the topology prediction message transmission time, and send it to the neighboring satellite node;

[0014] (5) After receiving the routing control message, the satellite node stores it in the message processing queue and floods the routing control message within a limited area;

[0015] (6) Take out the routing control message from the message processing queue of the satellite node, parse the topology prediction message in it, arrange the order of updating the satellite node routing table according to the link change time, calculate the virtual routing table entry before the link change time, use the virtual routing table entry to switch the satellite node routing table entry at the link change time, and send out the route.

[0016] Furthermore, in step (1), the orbital parameters of the satellite node are initialized, and the angular velocity ω, orbital period T, and true anomaly angle θ of the satellite node are calculated. t and spatial location (x) t y t , z t ), which includes:

[0017] (1a) Initialize the satellite node orbital parameters {α, e, i, Ω, ω, v}, where α is the semi-major axis of the satellite node, e is the eccentricity of the satellite node, i is the orbital inclination of the satellite node, Ω is the right ascension of the ascending node of the satellite node, ω is the argument of perigee of the satellite node, and v is the mean perigee of the satellite node.

[0018] (1b) Based on the Earth's radius R and the satellite's orbital altitude h s Calculate the semi-major axis of the satellite node: r = R + h s Calculate the satellite's angular velocity based on its semi-major axis r. Calculate the orbital period based on the satellite's angular velocity ω Where G is the gravitational constant and M is the mass of the Earth;

[0019] (1c) Calculate the true anomaly angle θ of the satellite at any time. t and spatial location [x t y t , z t ].

[0020] Furthermore, in step (2), the inter-satellite link set of the satellite nodes is initialized, and the ground station determines the inter-satellite link set {(l i costi S i S j The angular velocity ω, orbital period T, and true anomaly angle θ of the satellite node are given. t and spatial location (x) t y t , z t The satellite link connection and disconnection schedule is obtained through STK simulation using the satellite toolkit, including:

[0021] (2a) Initialize the set of inter-satellite links for the satellite nodes, represented as:

[0022] {(l i cost i S i S j )},i,∈[0,n]

[0023] Among them, l i Cost represents the i-th link in the satellite network. i S represents the cost value of the i-th link. i and S j Represents the starting satellite node ID and the destination satellite node ID of the link, where n is the number of nodes in the satellite internet;

[0024] (2b) The ground station will set up the inter-satellite links of the satellite nodes {(l i cost i S i S j The angular velocity ω, orbital period T, and true anomaly angle θ of the satellite node are also considered. t and spatial location (x) t y t , z t As input data to the STK satellite toolkit, the simulation outputs a timetable of link connectivity for satellite nodes.

[0025] Furthermore, in step (3), the satellite node generates a topology prediction message after receiving the link connectivity schedule, which includes the following implementation:

[0026] (3a) Satellite nodes obtain data from the link connection and disconnection schedule.

[0027] (3b) Determine if the satellite node is equal to S i :

[0028] If the two are not equal, skip the data and continue reading the next data until the link connectivity table is traversed.

[0029] If the two are equal, then read the corresponding link information l i Link cost valuei Link state value i With the link change time Δt i The topology prediction message is generated. The structure of the topology prediction message is based on the Network Layer Reachability Information (NLRI) structure, with the addition of a link change time attribute. This attribute is a 32-bit integer data type, which is used to set a timer to calculate the virtual routing table of the satellite node.

[0030] Furthermore, the calculation of the difference between the two in step (4) to determine the topology prediction message transmission time includes the following implementation:

[0031] (4a) Based on the system clock value T of the satellite node c The sending period T of routing control messages Route Calculate the time t when the routing control message is sent. Route ;

[0032] (4b) Based on the link change time Δt in the topology prediction message i With the routing control message sent at time t Route Calculate the difference ΔT between the two. i :

[0033] (4c) The difference ΔT i The topology prediction message transmission threshold T set with the satellite node threshold Comparison:

[0034] If ΔT i ≤T threshold If so, the satellite node immediately generates a routing control message and merges it with the topology prediction message, then sends it to the neighboring satellite node;

[0035] If ΔT i >T threshold If so, the topology prediction message is stored in the topology prediction message to be sent sequence. When the routing control message is sent, all the topology prediction messages in the sequence are merged into the routing control message and sent to the neighboring satellite node.

[0036] Furthermore, the flooding of the routing control message within the limited area in (5) includes the following implementation:

[0037] (5a) Based on the orbital position (x) of the satellite node o y0) Information computing satellite node region ID:

[0038]

[0039] Among them, M o is the number of orbits for satellite internet, h is the number of horizontal orbital planes in the region, and l is the number of vertical orbital planes in the region;

[0040] (5b) The satellite node compares the AS number in the routing control message with the calculated area ID:

[0041] If the AS number equals the area ID, the routing control message is stored in the message processing queue of the satellite node and forwarded to the neighboring satellite node.

[0042] If the AS number is not equal to the area ID, then stop forwarding the routing control message and discard the message.

[0043] Furthermore, the implementation of (6) in which the routing table update order is arranged according to the time of link changes includes:

[0044] (6a) The satellite node obtains the routing control message from the message processing queue, parses the topology prediction message in the routing control message, and obtains the link information in the message. i Link change time Δt i Link cost value i Link state i Link start node S i and the destination node S of the link j ;

[0045] (6b) Satellite nodes determine the start time ΔT of virtual route calculation i :

[0046] ΔT i =Δt i -T pre

[0047] Among them, T pre The maximum virtual route computation time set for satellite nodes.

[0048] (6c) Satellite nodes at ΔT i A timer is constantly set to perform virtual route calculations, obtain the virtual routing table for the satellite nodes, and then... i The basic network layer of the satellite nodes constantly replaces the routing tables of the satellite nodes with virtual routing tables.

[0049] 2. A time-varying routing system for satellite internet, characterized in that it comprises:

[0050] The topology prediction message generation module is used by satellite nodes to receive the link connection and disconnection timetable sent by the ground station, parse the link change data in it, and generate topology prediction messages.

[0051] The topology prediction message sending module is used to calculate the difference between the link change time of the topology prediction message and the sending time of the routing control message, determine the message sending time, merge the topology prediction message into the routing control message, and then send it to the surrounding neighboring nodes.

[0052] The limited area flooding module is used to determine the transmission range of a routing control message after the satellite node receives it. This is done by comparing the AS number of the routing control message with the area ID to which the satellite node belongs. If they are equal, the message is sent to neighboring nodes. Otherwise, the message is discarded.

[0053] The virtual route calculation module is used by satellite nodes to parse topology prediction messages and set timers to perform virtual route calculations, reading the link change time Δt in the topology prediction messages. i To determine the start time ΔT for virtual route calculation i And at that moment, a timer is set to perform virtual route calculation, in Δt i The routing table of the satellite node is constantly replaced with a virtual routing table and sent to the basic network layer of the satellite node.

[0054] 3. An electronic device, comprising a processor, a memory, an input / output device, a communication interface, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the program to implement a time-varying routing method for the satellite internet.

[0055] 4. A computer-readable storage medium, characterized in that the storage medium stores computer instructions for causing the computer to execute the time-varying routing method for satellite internet described above.

[0056] Compared with the prior art, the present invention has the following advantages:

[0057] Firstly, in this invention, after the satellite node receives the link connection / disconnection time table, it generates a topology prediction message, merges it into a routing control message, and sends it at the same time as the routing control message. By limiting the frequency of message transmission, the transmission load of the network is effectively reduced.

[0058] Secondly, in this invention, topology prediction messages and satellite network routing calculations are performed only within a limited area, effectively reducing network congestion and resource waste between satellite network nodes.

[0059] Third, in this invention, after receiving the topology prediction message, the satellite node determines the virtual routing table update time based on the link change time, sets a timer to start routing calculation at the start time of virtual routing calculation, and switches the routing table to a virtual routing table at the link change time, which effectively reduces the probability of outdated routes and packet loss, and ensures the service quality of satellite Internet. Attached Figure Description

[0060] Figure 1 This is a flowchart of the implementation of a time-varying routing method for satellite internet provided in Embodiment 1 of the present invention;

[0061] Figure 2 This is a topology prediction message structure diagram in Embodiment 1 of the present invention;

[0062] Figure 3 This is a schematic diagram of the region in Embodiment 1 of the present invention;

[0063] Figure 4 This is a schematic diagram of node routing calculation in Embodiment 1 of the present invention;

[0064] Figure 5 This is a block diagram of a time-varying routing system for satellite internet provided in Embodiment 2 of the present invention;

[0065] Figure 6 This is a schematic diagram of the electronic device structure provided in Embodiment 3 of the present invention. Detailed Implementation

[0066] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should all fall within the protection scope of the present invention.

[0067] The implementation scenario of this example involves the frequent changes in network topology in satellite internet due to factors such as solar interference and satellite movement, resulting in heavy information exchange load between satellites. It is necessary to update the network topology in a timely manner and reduce the transmission load to ensure the quality of communication services and provide an efficient and reliable service environment for other on-board services.

[0068] Example 1: The satellite internet time-varying routing method provided by the present invention.

[0069] Reference Figure 1 The implementation steps of this example include the following:

[0070] Step 1: Initialize the satellite node.

[0071] The initial topology prediction message sequence to be sent is empty, and the initial message processing queue is empty.

[0072] Set the topology prediction message sending threshold to T. thresholdSet the orbital parameters of the satellite node as {r, e, i, Ω, δ, v}, where r is the semi-major axis of the satellite node, e is the eccentricity of the satellite node, i is the orbital inclination of the satellite node, Ω is the right ascension of the ascending node of the satellite node, δ is the argument of perigee of the satellite node, and v is the mean perigee of the satellite node.

[0073] Step 2: Calculate the satellite's angular velocity ω, orbital period T, and true anomaly angle θ at any given time. t and spatial location (x) t y t , z t ).

[0074] 2.1) Based on the Earth's radius R and the satellite's orbital altitude h s Calculate the semi-major axis r of the satellite node:

[0075] r = R + h s ;

[0076] 2.2) Calculate the satellite's angular velocity w based on its semi-major axis r:

[0077]

[0078] Where G is the gravitational constant and M is the mass of the Earth;

[0079] 2.3) Calculate the orbital period T based on the satellite's angular velocity w:

[0080]

[0081] 2.4) Calculate the true anomaly angle θ of the satellite at any given time. t and spatial location (x) t y t , z t ):

[0082] 2.4.1) Calculate the true anomaly angle θ of the satellite at any given time based on the initial true anomaly angle θ0 and angular velocity ω. t :

[0083] θ t =θ0+ω t ;

[0084] 2.4.2) Based on the orbital plane rotation angle θ of the satellite at any given time t The satellite coordinates (x) in the orbital plane are calculated using the semi-major axis r of the satellite node. w y w ):

[0085] x w =r cosθ t y w =r sinθt ;

[0086] 2.4.3) Based on the satellite coordinates (x) in the orbital plane w y w ) Calculate the satellite's spatial position (x t y t , z t ):

[0087]

[0088] Where Ω is the right ascension of the ascending node; i is the orbital inclination.

[0089] It should be noted that the satellite's spatial position can also be calculated based on radial distance, as follows:

[0090] First, calculate the radial distance α of the satellite based on the semi-major axis r and eccentricity e of the satellite node:

[0091] α = r(1 - e cos(E)), where E is the near-point angle of the satellite node;

[0092] Secondly, calculate the satellite's orbital plane coordinates (x′, y′) based on the satellite's true anomaly angle θ:

[0093] x′=αcosθ, y′=αsinθ;

[0094] Finally, the satellite's spatial position (x, y, z) is calculated based on the satellite coordinates (x′, y′) in the orbital plane:

[0095]

[0096] Where Ω is the right ascension of the ascending node of the satellite; i is the orbital inclination of the satellite.

[0097] Step 3: Initialize the set of inter-satellite links for the satellite nodes.

[0098] The inter-satellite link includes the link for establishing communication between satellites, the link overhead value, and the starting and destination nodes of the link, which are used to describe the information of the link in the satellite Internet.

[0099] The initial set of inter-satellite links for each satellite node is represented as:

[0100] {(l i cost i S i S j )}, i, j∈[0, n]

[0101] Among them, l i Cost represents the i-th link in the satellite network. iS represents the cost value of the i-th link. i and S j The two satellite nodes represent the starting and destination satellite nodes of the link, and n is the number of satellite nodes in the satellite internet.

[0102] Step 4: Construct a timetable for link connectivity and disconnection for the satellite nodes and send it to the satellite nodes.

[0103] 4.1) The ground station will set up the inter-satellite links of the satellite nodes {(l i cost i S i S j )}, i, j∈[0, n] and the angular velocity ω, orbital period T, true anomaly angle θ of the satellite node t and spatial location (x) t y t , z t Using the data as input, the system simulates the data using the STK satellite toolkit and outputs the links in the Internet, the cost values ​​of the links, the connection status of the links, the times when the links change, and the starting and destination nodes of the links.

[0104] 4.2) The output from the STK satellite toolkit simulation is used to form a link connectivity and disconnection timetable for satellite nodes, which describes the link information when the satellite internet topology changes. The link connectivity and disconnection time can be expressed as:

[0105]

[0106] Among them, l i Let cost represent the cost of the i-th link. i Represents the cost value of the i-th link, state i Indicates the state of the i-th link, Δt i S represents the moment of change in this link. i and S j These represent the starting node and the destination node of the link, respectively.

[0107] It should be noted that the satellite link connection and disconnection timetable can also be calculated using orbital plane coordinates and connection relationships, as follows:

[0108] First, based on the satellite's orbital plane coordinates (x... w y w Determine the neighboring nodes of the satellite node, such as Figure 3 As shown, based on the basic configuration of satellite internet, each satellite node without boundaries has four neighboring nodes, namely, satellites S in the same orbit. a (x w -μ,y w ), S b (xw +μ,y w Heteroorbital satellite S c (x w y w -μ), S d (x w y w +μ), where μ is the unit length of the satellite network orbit coordinates;

[0109] Secondly, considering the periodic motion of the satellite, the satellite coordinates are calculated every T time interval, and the neighboring nodes of the satellite node are recorded and compared with the neighboring nodes of the previous period. When the satellite's neighboring nodes change, the link data of this change is recorded, denoted as .

[0110] Finally, after calculating the orbital coordinates of satellite nodes for all cycles, the recorded link change data is used to construct a link connection and disconnection timetable.

[0111] Step 5: After receiving the link connection and disconnection timetable sent by the ground station, the satellite node sequentially traverses to obtain the data for each link. Generate topology prediction messages for the link at different times.

[0112] 5.1) Satellite nodes obtain data from the link connection / disconnection timetable. Determine if the satellite node is equal to S i :

[0113] If the two are not equal, skip the data and continue reading the next data until the link connectivity table is traversed.

[0114] If the two are equal, then read the corresponding link information l i Link cost value i Link state value i With the link change time Δt i Generate topology prediction messages;

[0115] 5.2) The topology prediction message structure of this invention is as follows: Figure 2 As shown, it adds a link change time attribute to the Network Layer Reachability Information (NLRI) infrastructure. This attribute is a 32-bit integer data type used by satellite nodes to set timers to calculate virtual routes. Each topology prediction message contains only the state information parameters of one link. Topology prediction messages need to be merged into routing control messages for transmission. A routing control message can contain multiple topology prediction messages. During transmission, one or more topology prediction messages are merged into a routing control message and sent in descending time order.

[0116] It should be noted that routing control messages are a type of message defined by the network layer of the satellite internet routing protocol. They use the IP protocol for communication and are used to maintain the network topology and shortest path tree of the satellite internet. Due to the periodicity of satellite movement, satellite nodes are configured to periodically send routing control messages to maintain the overall network topology.

[0117] Step 6: The satellite node calculates the routing control message transmission time t. Route And determine the timing of sending the routing control message.

[0118] 6.1) Satellite nodes based on system clock value T c The sending period T of routing control messages Route Calculate the time t when the routing control message is sent. Route :

[0119]

[0120] 6.2) Satellite nodes predict the link change time Δt in the topology prediction message. i With the routing control message sent at time t Route Calculate the time difference ΔT i :

[0121] ΔT i =Δt i -t Route ;

[0122] 6.3) ΔT i With the set topology prediction message sending threshold value T threshold Compare the data to determine the timing of the routing control message transmission:

[0123] If ΔT i ≤T threshold If the current topology prediction message is not empty, a routing control message is generated, and the current topology prediction message is merged into the routing control message. If the topology prediction message to be sent sequence is not empty at this time, all topology prediction messages in the sequence are merged into the routing control message, stored in the message processing queue, and sent to the neighboring nodes around the satellite node to flood the message within the limited area.

[0124] If ΔT i >T threshold If the topology prediction message is added to the topology prediction message to be sent sequence, when the routing control message is sent periodically, all topology prediction messages in the sequence are taken out, merged into the routing control message, stored in the message processing queue of the satellite node, and sent to the neighboring nodes around the satellite node to flood the message within the limited area.

[0125] Step 7: When a satellite node receives a routing control message, it stores it in a message processing queue and determines whether to send the message to a neighboring satellite node based on whether the AS number in the message is equal to the area ID to which its own node belongs.

[0126] 7.1) Satellite Internet Regional Division.

[0127] Based on the neighbor relationships between a single satellite and its left and right nodes in the same orbit, and its upper and lower nodes in different orbits, a grid-like topology is formed, which is considered the basic topological unit of the satellite network. The grid-like topology is then expanded to form a general satellite internet region, such as... Figure 3 As shown;

[0128] It should be noted that satellite internet areas can also be divided according to frequency bands. Satellite nodes are divided according to their frequency bands. Satellites with the same frequency band form an area. Satellite nodes only transmit information within the area. Only the boundary nodes of the area can communicate with satellites in other areas.

[0129] 7.2) The orbital position information of any satellite node selected in the satellite internet region is used as (x o y o ) indicates that, where x o This indicates that the satellite node is at the x-th position in the satellite network. o On each orbital plane, y o This indicates that the satellite node is the y-th node on this orbital plane. o One satellite;

[0130] 7.3) Calculate the region ID of the satellite node based on its orbital position information (x0, y0):

[0131]

[0132] Among them, M o is the number of orbits for satellite internet, h is the number of horizontal orbital planes in the region, and l is the number of vertical orbital planes in the region;

[0133] 7.4) The satellite node compares the AS number in the control message with the calculated area ID:

[0134] If the AS number equals the area ID, the routing control message is stored in the message processing queue of the satellite node and forwarded to the surrounding neighboring satellite nodes.

[0135] If the AS number is not equal to the area ID, then stop forwarding the routing control message and discard it.

[0136] Step 8: The satellite node retrieves the routing control message from the message processing queue, parses the topology prediction message within it, and determines the start time of the virtual route calculation.

[0137] 8.1) Satellite nodes obtain link information from topology prediction messages. i Link change time Δt i Link cost value i Link state i Link start node S i and the destination node S of the link j And according to Δt i To arrange the update order of the satellite node routing table, the result is as follows: Figure 4 As shown;

[0138] 8.2) Satellite nodes determine the start time Δt for virtual route calculation i :

[0139] ΔT i =Δt i -T pre

[0140] Among them, T pre The virtual route calculation time set for satellite nodes, Δt i The link change time obtained after the satellite node has parsed the topology prediction message.

[0141] Step 9: The satellite node calculates the virtual routing table at the time of link change Δt. i Switch the routing table and send routes to the underlying network layer.

[0142] 9.1) Set a virtual route calculation timer for the satellite node, with the trigger time being the start time Δt of the virtual route calculation. i This yields the virtual routing table of the satellite node. This virtual routing table is an independently operating routing table on the satellite node, storing routing information after changes in the satellite node's links. It cannot be directly used to issue routes.

[0143] 9.2) Set a routing table switching timer for the satellite node, with the trigger time being the link change time Δt. i The routing table of the satellite node is replaced with a virtual routing table, and routes are sent to the basic network layer of the satellite node.

[0144] Example 2: The satellite internet time-varying routing system provided by the present invention.

[0145] Reference Figure 5 The system modules in this example include: topology prediction message generation module 1, topology prediction message sending module 2, limited area flooding module 3, and virtual route calculation module 4. Their working principles are as follows:

[0146] After system startup, the topology prediction message generation module 1 receives the link connectivity timetable sent by the ground station, parses the link change data, generates a topology prediction message, and passes the message to the topology prediction message sending module 2. The topology prediction message sending module 2 determines the message sending time based on the difference between the link change time and the routing control message, merges the topology prediction message into the routing control message in the satellite internet communication protocol, and sends it to surrounding neighboring nodes. It also passes the message to the limited area flooding module 3. Upon receiving the message, the limited area flooding module 3 checks the equality between the AS number of the message and the area ID of the node. If they are not equal, the message is discarded; if they are equal, the message is sent to surrounding neighboring nodes, and the virtual route calculation module 4 is invoked. The virtual route calculation module 4 determines the start time of the virtual route calculation, sets a timer to perform the virtual route calculation, replaces the routing table of the satellite node with the virtual routing table at the link change time, and sends it down to the basic network layer of the satellite node.

[0147] Example 3: The electronic device provided by the present invention.

[0148] Reference Figure 6 The electronic device in this example includes a processor, memory, input / output interfaces, and communication interfaces, wherein:

[0149] The processor is implemented using a general-purpose central processing unit (CPU), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0150] The memory can be implemented using read-only memory (ROM), random access memory (RAM), static RAM (SRAM), or dynamic storage device (DRAM), etc. It can store the satellite internet time-varying routing system program provided by this invention, which can be called and executed by a processor.

[0151] The input / output interface is used to connect to the input / output module to realize data input and output;

[0152] The communication interface is used to connect the communication module to enable communication between this device and the ground station equipment. The communication module can communicate via wired or wireless means.

[0153] It should be noted that although the above-described device only shows the processor, memory, input / output interface, and communication interface, in actual implementation, the device may also include other components necessary for normal operation. Furthermore, those skilled in the art will understand that the above-described device may only include the components necessary for implementing the embodiments of this specification, and not necessarily all the components shown in the figures.

[0154] Example 4: The computer-readable medium provided by the present invention.

[0155] This embodiment provides a computer-readable medium storing multiple instructions that can be loaded by a processor to execute steps in any of the satellite internet time-varying routing methods provided in this embodiment of the invention.

[0156] The computer-readable medium in this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented using any method or technology; the information can be computer-readable instructions, data structures, program modules, or other data. Computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory, or other memory technologies, which can be used to store information accessible by computing devices.

[0157] It should be noted that the step numbers in the specification and claims of this invention are only for the purpose of clearly describing the embodiments of this invention and facilitating understanding, and their order is not limited.

Claims

1. A time-varying routing method for satellite internet, characterized in that, include: (1) Initialize the satellite nodes, initialize the topology prediction message waiting sequence to be sent to be empty, initialize the message processing queue to be empty, and set the topology prediction message sending threshold value to T. threshold Initialize the orbital parameters of the satellite node, and calculate the angular velocity ω, orbital period T, and true anomaly angle θ of the satellite node. t and spatial location (x) t y t , z t ); (2) Initialize the inter-satellite link set of the satellite nodes. The ground station uses the inter-satellite link set {(l i cost i S i S j The angular velocity ω, orbital period T, and true anomaly angle θ of the satellite node are given. t and spatial location (x) t y t , z t The satellite link connectivity schedule is obtained through STK simulation using the satellite toolkit, and then sent to the satellite node; where l i Cost represents the i-th link in the satellite network. i S represents the cost value of the i-th link. i and S j Representing the starting and destination satellite nodes of the link, representing the number of nodes in the satellite internet; (3) After receiving the link connection and disconnection timetable, the satellite node parses the link change data in it and generates a topology prediction message, which includes the link change time, link change status, link cost value, link start node and destination node information. (4) Obtain the routing control message transmission time from the system clock of the satellite, obtain the link change time from the topology prediction message, calculate the difference between the two to determine the topology prediction message transmission time, and send it to the neighboring satellite node; (5) After receiving the routing control message, the satellite node stores it in the message processing queue and floods the routing control message within a limited area; the limited area is the message transmission range determined after the satellite node receives the routing control message; (6) Take out the routing control message from the message processing queue of the satellite node, parse the topology prediction message in it, arrange the order of updating the satellite node routing table according to the link change time, calculate the virtual routing table entry before the link change time, use the virtual routing table entry to switch the satellite node routing table entry at the link change time, and send out the route.

2. The method according to claim 1, characterized in that, In step (1), the orbital parameters of the satellite node are initialized, and the angular velocity ω, orbital period T, and true anomaly angle θ of the satellite node are calculated. t and spatial location (x) t y t , z t Its implementation includes: (1a) Initialize the satellite node orbital parameters {r, e, i, Ω, δ, v}, where r is the semi-major axis of the satellite node, e is the eccentricity of the satellite node, i is the orbital inclination of the satellite node, Ω is the right ascension of the ascending node of the satellite node, δ is the argument of perigee of the satellite node, and v is the mean perigee of the satellite node. (1b) Calculate the satellite's angular velocity ω and orbital period T: Based on the Earth's radius R and the satellite's orbital altitude h s Calculate the semi-major axis of the satellite node: r = R + h s ; Calculate the satellite's angular velocity based on its semi-major axis r. Where G is the gravitational constant and M is the mass of the Earth; Calculate the orbital period based on the satellite's angular velocity ω (1c) Calculate the true anomaly angle θ of the satellite at any given time. t and spatial location (x) t y t , z t ): Calculate the true anomaly angle θ0 of the satellite at any given time based on the initial true anomaly angle θ0 and angular velocity ω. t =θ0+ωt, where t is any time; Based on the satellite's true anomaly angle θ at any given time t The satellite coordinates (x) in the orbital plane are calculated using the semi-major axis r of the satellite node. w y w ): x w =r cosθ t ,y w =r sin θ t ; According to the satellite coordinates (x) in the orbital plane w y w ) Calculate the satellite's spatial position (x t y t , z t ): Where Ω is the right ascension of the ascending node; i is the orbital inclination.

3. The method according to claim 1, characterized in that, In step (2), the inter-satellite link set of the satellite nodes is initialized, and the ground station uses the inter-satellite link set {(l i cost i S i S j The angular velocity ω, orbital period T, and true anomaly angle θ of the satellite node are given. t and spatial location (x) t y t , z t The satellite link connection and disconnection schedule is obtained through STK simulation using the satellite toolkit, including: (2a) Initialize the set of inter-satellite links for the satellite nodes, represented as: {(l i ,cost i ,S i ,S j )},i,j∈[0,n] (2b) The ground station will set up the inter-satellite links of the satellite nodes {(l i cost i S i S j The angular velocity ω, orbital period T, and true anomaly angle θ of the satellite node are also considered. t and spatial location (x) t ,y t ,z t As input data to the STK satellite toolkit, the simulation outputs a timetable of link connectivity and disconnection for the satellite nodes, represented as follows: Among them, l i Let cost represent the cost of the i-th link. i Represents the link cost value, state i Indicates the link status, Δt i S represents the moment of link change. i and S j These represent the starting and ending nodes of the link, respectively.

4. The method according to claim 1, characterized in that, The satellite node in (3) generates a topology prediction message after receiving the link connectivity schedule, which includes the following implementation: (3a) Satellite nodes obtain data from the link connection and disconnection schedule. (3b) Determine if the satellite node is equal to S i : If the two are not equal, skip the data and continue reading the next data until the link connection and disconnection timetable is traversed. If the two are equal, then read the corresponding link information l i Link cost value i Link state value i With the link change time Δt i The topology prediction message is generated. The structure of the topology prediction message is based on the Network Layer Reachability Information (NLRI) structure, with the addition of a link change time attribute. This attribute is a 32-bit integer data type, which is used to set a timer to calculate the virtual routing table of the satellite node.

5. The method according to claim 1, characterized in that, The calculation of the difference between the two in (4) to determine the topology prediction message transmission time includes the following implementation: (4a) Based on the system clock value T of the satellite node c The sending period T of routing control messages Route Calculate the time t when the routing control message is sent. Route : (4b) Based on the link change time Δt in the topology prediction message i With the routing control message sent at time t Route Calculate the difference ΔT between the two. i : ΔT i =Δt i -t Route ; (4c) The difference ΔT i The topology prediction message transmission threshold T set with the satellite node threshold Comparison: If ΔT i ≤T threshold If so, the satellite node immediately generates a routing control message and merges it with the topology prediction message, then sends it to the neighboring satellite node; If ΔT i >T threshold If so, the topology prediction message is stored in the topology prediction message to be sent sequence. When the routing control message is sent, all the topology prediction messages in the sequence are merged into the routing control message and sent to the neighboring satellite node.

6. The method according to claim 1, characterized in that, The implementation of flooding the routing control message within the limited area in (5) includes: (5a) Based on the orbital position of the satellite node (x o y0) Information computing satellite node region ID: Among them, M o is the number of orbits for satellite internet, h is the number of horizontal orbital planes in the region, and l is the number of vertical orbital planes in the region; (5b) The satellite node compares the AS number in the routing control message with the calculated area ID: If the AS number equals the area ID, the routing control message is stored in the message processing queue of the satellite node and forwarded to the neighboring satellite node. If the AS number is not equal to the area ID, then stop forwarding the routing control message and discard the message.

7. The method according to claim 1, characterized in that, The implementation of (6) in which the routing table update order is arranged according to the time of link change includes: (6a) The satellite node obtains the routing control message from the message processing queue, parses the topology prediction message in the routing control message, and obtains the link information in the message. i Link change time Δt i Link cost value i Link state i Link start node S i and the destination node S of the link j ; (6b) Satellite nodes determine the virtual route calculation start time ΔT i : ΔT i =Δt i -T pre Among them, T pre The maximum virtual route computation time set for satellite nodes. (6c) Satellite nodes at ΔT i A timer is constantly set to perform virtual route calculations, obtain the virtual routing table for the satellite nodes, and then... i The basic network layer of the satellite nodes constantly replaces the routing tables of the satellite nodes with virtual routing tables.

8. A time-varying routing system for satellite internet, characterized in that, include: The topology prediction message generation module is used by satellite nodes to receive the link connection and disconnection timetable sent by the ground station, parse the link change data in it, and generate a topology prediction message; it includes the link change time, link change status, link cost value, link start node and destination node information; The topology prediction message sending module is used to calculate the difference between the link change time of the topology prediction message and the sending time of the routing control message, determine the message sending time, merge the topology prediction message into the routing control message, and then send it to the surrounding neighboring nodes. The limited area flooding module is used to determine the transmission range of a routing control message after the satellite node receives it. This is done by comparing the AS number of the routing control message with the area ID to which the satellite node belongs. If they are equal, the message is sent to neighboring nodes. Otherwise, the message is discarded. The virtual route calculation module is used by satellite nodes to parse topology prediction messages and set timers to perform virtual route calculations, reading the link change time Δt in the topology prediction messages. i To determine the start time ΔT for virtual route calculation i And at that moment, a timer is set to perform virtual route calculation, in Δt i The routing table of the satellite node is constantly replaced with a virtual routing table and sent to the basic network layer of the satellite node.

9. An electronic device, comprising a processor, a memory, an input / output device, a communication interface, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the time-varying routing method for satellite internet as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The storage medium stores computer instructions for instructing the computer to execute the time-varying routing method for satellite internet as described in any one of claims 1 to 7.

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