Inter-satellite link packet switching simulation method based on data exchange matrix

Abstract

The invention provides an inter-satellite link packet switching simulation method based on a data exchange matrix. The inter-satellite link packet switching simulation method comprises the following steps: acquiring a topological snapshot of an inter-satellite link in each time interval, and configuring a corresponding constraint for an inter-satellite link switching process; based on the adjacent inter-satellite link target sets calculated by the topological snapshots and the satellite node sets corresponding to the links of the inter-satellite link target sets, analyzing and calculating inter-satellite link switching groups meeting constraints, a link breaking time sequence and a link building time sequence; and finally, simulating satellite nodes and inter-satellite links of a large-scale constellation network, and based on the inter-satellite link switching group, the link breaking time sequence and the link building time sequence, carrying out constellation network link topology switching process simulation. Therefore, the connectivity of the large-scale constellation network during inter-satellite link switching can be ensured, the routing convergence time in the topology switching process is shortened, and the reduction of network performance is avoided; efficient simulation of the laser inter-satellite link switching process in a super-large-scale network scene is completed within finite time, the defect that traditional inter-satellite link switching simulation based on mathematical calculation cannot meet the requirements for real-time response to link disconnection and network reconstruction is overcome, the simulation system overhead is effectively reduced, and the simulation efficiency of a constellation network is improved.

Description

Technical Field

[0001] The invention relates to the technical field of satellite communication networks, and in particular to an inter-satellite link packet switching simulation method based on a data exchange matrix. Background Art

[0002] In recent years, the rapid launch and networking of low-orbit giant constellations represented by Starlink heralds the arrival of the era of low-orbit giant constellations. The construction of a new generation of space seven-layer system architecture and hybrid space architecture will build a space-based mesh information network composed of hundreds of satellites, becoming an important foundation for future military, commercial and civilian multi-system intersatellite interconnection. Among them, intersatellite links play an important role in the interconnection of large-scale satellite constellation networks, especially the application of tens / hundreds of Gbps laser intersatellite links in the construction of giant constellations, which can effectively overcome the problem of insufficient bandwidth of traditional microwave intersatellite links.

[0003] Large-scale satellite constellation networks have huge nodes, wide temporal and spatial distribution, and frequent changes in network topology. Considering the predictability of time-varying topology, the order of intersatellite link switching can generally be pre-scheduled to ensure the connectivity of the intersatellite network. However, it takes a long time to establish a stable laser intersatellite link. If efficient and fast intersatellite link switching cannot be achieved, the isolated topology and slow routing convergence may lead to serious service interruptions. If the intersatellite links are switched one by one, the routing oscillation time of large-scale satellite networks will continue to increase with frequent intersatellite switching, resulting in a large amount of packet loss and unpredictable network delays.

[0004] In addition, high-fidelity reproduction of the inter-satellite link switching process of a large-scale satellite constellation network relies on the real constellation network environment to provide correct physical layer and network layer characteristics. However, the existing inter-satellite link switching simulation is mainly based on mathematical calculations, which cannot meet the network requirements of real-time response to link disconnection and reconstruction. Therefore, there is an increasingly urgent need to build a large-scale satellite constellation network link simulation test environment and restore the high dynamics of the network topology.

[0005] Therefore, there is an urgent need for a method that can effectively solve the problems of the prior art. Summary of the invention

[0006] The purpose of the present invention is to provide an intersatellite link group switching simulation method based on a data exchange matrix, reduce the routing convergence time in the topology state switching process, and effectively avoid the degradation of constellation network performance and service interruption; and support the completion of efficient simulation of the laser intersatellite link switching process in a super-large-scale network scenario within a limited time, make up for the shortcomings of the traditional intersatellite link switching simulation based on mathematical calculations that cannot meet the real-time response to link disconnection and network reconstruction requirements, effectively reduce the system simulation overhead, and improve the simulation efficiency of the constellation network.

[0007] In order to achieve the above object, the present invention provides an inter-satellite link packet switching simulation method based on a data exchange matrix, comprising the steps of:

[0008] According to the visible relationship matrix between all satellite nodes in the satellite constellation network, the topological snapshot of the inter-satellite link in each time interval is obtained; and the satellite node transponder quantity constraint and the constellation network topology connectivity constraint are configured for the inter-satellite link switching process;

[0009] According to the intersatellite link target set calculated based on the adjacent topology snapshots and the satellite node set corresponding to the link, a bipartite graph of the intersatellite link network topology is obtained; and based on the network topology bipartite graph, the intersatellite link switching grouping and the link breaking time sequence and the link establishing time sequence that satisfy the satellite node transponder quantity constraint and the constellation network topology connectivity constraint are analyzed and calculated; wherein the intersatellite link target set is a collection of a first intersatellite link set and a second intersatellite link set, the first intersatellite link set is a set of intersatellite links dismantled by a first topology snapshot, the second intersatellite link set is a set of intersatellite links newly established by a second topology snapshot, and the first topology snapshot and the second topology snapshot are two adjacent topology snapshots;

[0010] According to the satellite constellation time-varying network intersatellite link topology model, a number of satellite node containers are generated, and a data exchange matrix connected to the virtual network cards of the several satellite node containers is created; the intersatellite link switching group, the link breaking time series and the link establishing time series are used as virtual network port parameters of the data exchange matrix, and the whole network adjacency table stored in the data exchange matrix is ​​updated at a predetermined time interval to simulate the constellation network link topology switching process.

[0011] Optionally, the obtaining of a topology snapshot of an inter-satellite link in each time interval according to a visible relationship matrix between all satellite nodes in the satellite constellation network; and configuring a satellite node transponder quantity constraint and a constellation network topology connectivity constraint for the inter-satellite link switching process include:

[0012] Calculating the visible relationship three-dimensional matrix of all satellite nodes in the satellite constellation network within the entire period, and obtaining an inter-satellite link topology snapshot within each time interval based on the visible relationship three-dimensional matrix;

[0013] Set a satellite node transponder number constraint that the maximum number of intersatellite links that can be established by a single satellite node does not exceed the number of transponders that can be used to establish intersatellite links;

[0014] A constellation network topology connectivity constraint is set that there is at least one reachable path between any pair of satellite nodes in the satellite constellation network.

[0015] Optionally, the constraint expression for the satellite node transponder quantity constraint is:

[0016] Σ j∈V e ij ≤cnt trans ;

[0017] Among them, when e ij =1 indicates satellite node s i and satellite nodes j There is an intersatellite link between trans For a single satellite node s i The number of transponders that can be used to establish intersatellite links. i and j are satellite node numbers.

[0018] Optionally, the constraint expression of the constellation network topology connectivity constraint is:

[0019]

[0020]

[0021]

[0022] Among them, E r A is the set of intersatellite links in the entire network after c intersatellite links are removed. r is the adjacency matrix after removing c intersatellite links, B r is the intersatellite reachability matrix when the link is removed, remove(e ij ) is to disconnect the communicative intersatellite link e ij moment, N represents the number of satellite nodes in the satellite constellation network.

[0023] Optionally, obtaining an inter-satellite link network topology bipartite graph according to an inter-satellite link target set calculated based on adjacent topology snapshots and a set of satellite nodes corresponding to their links comprises:

[0024] Calculating common inter-satellite links in two adjacent topology snapshots;

[0025] Calculate, based on the common intersatellite links, a first intersatellite link set removed by a first topology snapshot in the adjacent topology snapshots and a second intersatellite link set newly established by a corresponding second topology snapshot in the adjacent topology snapshots;

[0026] The first intersatellite link set and the second intersatellite link set are combined to obtain an intersatellite link target set, and based on the intersatellite link target set and its corresponding satellite node set, an intersatellite link network topology bipartite graph is obtained.

[0027] Optionally, the analyzing and calculating, based on the network topology bipartite graph, the inter-satellite link switching grouping and the link disconnection time sequence and link establishment time sequence that satisfy the satellite node transponder quantity constraint and the constellation network topology connectivity constraint comprises:

[0028] Generating a plurality of independent subgraph sequences of the intersatellite link network topology bipartite graph;

[0029] Initialize the number M of independent intersatellite link subgraphs contained in each group of the topology switching group, where M=f-1, and f is the number of all independent subgraph sequences;

[0030] When M>0, all target switching groups of M independent subgraphs selected from all the independent subgraph sequences are calculated;

[0031] Determine whether the newly created intersatellite link of the target switching group meets the satellite node transponder quantity constraint, and whether the topology of the target switching group after the intersatellite link is removed meets the constellation network topology connectivity constraint;

[0032] If the conditions are met, the disconnection time of the intersatellite link in the corresponding target switching group and the time for re-establishing the new link are calculated;

[0033] The intersatellite link network topology bipartite graph is set as a subgraph after removing the target switching group, and M is reset to M=M-1, and the step of calculating all switching groups of M independent subgraphs selected from all the independent subgraph sequences when M>0 is returned;

[0034] When M=0, the intersatellite link switching group is calculated and saved, as well as the link disconnection time sequence of the corresponding disconnection time and the link establishment time sequence of the new link re-establishment.

[0035] Optionally, generating a plurality of satellite node containers according to the satellite constellation time-varying network inter-satellite link topology model, and creating a data exchange matrix connected to the virtual network cards of the plurality of satellite node containers includes:

[0036] Generate a number of satellite node containers according to the satellite constellation time-varying network inter-satellite link topology model;

[0037] A one-hop link layer connection is created between the virtual network cards of the plurality of satellite node containers, a data exchange matrix is ​​created, and a layer 2 Ethernet link is established between each of the virtual network cards and the data exchange matrix.

[0038] Optionally, the using the intersatellite link switching group, the link disconnection time sequence, and the link establishment time sequence as virtual network port parameters of the data exchange matrix to simulate the constellation network link topology switching process includes:

[0039] The intersatellite link switching group, the link disconnection time sequence and the link establishment time sequence are used as virtual network port parameters of the data exchange matrix to perform real-time response of link disconnection, reconstruction and maintenance status;

[0040] At every minimum time interval, the actual network topology connection relationship adjacency matrix at the current moment is updated to input the data exchange matrix to perform constellation network link topology switching process simulation.

[0041] The intersatellite link group switching simulation method based on the data exchange matrix of the present invention firstly uses the intersatellite link group switching strategy based on the bipartite graph to ensure the smooth disconnection and reconstruction of the intersatellite link, reduces the routing convergence time in the topology state switching process, and effectively avoids the degradation of constellation network performance and service interruption; then, through the intersatellite link topology containerization simulation based on the data exchange matrix, the high-fidelity reproduction of the real-time response of the large-scale intersatellite link disconnection and reconstruction process is realized, the internally stored full-network adjacency table is updated once at a minimum time interval, the storage overhead of the large-scale dynamic constellation network topology simulation is optimized, the system simulation overhead is effectively reduced, and the simulation efficiency of the constellation network is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A flowchart showing the steps of the inter-satellite link packet switching simulation method based on the data exchange matrix provided by an embodiment of the present invention is shown;

[0043] Figure 2 A flowchart showing the steps of generating a snapshot of a time-varying network topology of an inter-satellite link optionally used in the inter-satellite link packet switching simulation method based on a data exchange matrix provided in an embodiment of the present invention;

[0044] Figure 3 A flowchart showing the steps for generating inter-satellite link switching packets in the inter-satellite link packet switching simulation method based on a data exchange matrix provided in an embodiment of the present invention is provided;

[0045] Figure 4 A flowchart showing the steps of the inter-satellite link packet switching simulation method based on a data exchange matrix provided in an embodiment of the present invention, which is optionally used for data exchange matrix containerization simulation;

[0046] Figure 5 A specific example flow chart showing generation of inter-satellite link switching packets of the inter-satellite link packet switching simulation method based on a data exchange matrix provided by an embodiment of the present invention is shown;

[0047] Figure 6 A schematic diagram of the data exchange matrix structure of the inter-satellite link packet switching simulation method based on the data exchange matrix provided in one embodiment of the present invention is shown;

[0048] Figure 7 A schematic diagram showing a method for implementing dynamic switching of the data exchange matrix of the inter-satellite link packet switching simulation method based on the data exchange matrix provided by an embodiment of the present invention is shown;

[0049] Figure 8 A schematic diagram of the data exchange matrix updating process of the inter-satellite link packet switching simulation method based on the data exchange matrix provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0051] It should be noted that references to "one embodiment", "embodiment", "example embodiment", etc. in this specification refer to the embodiment described, which may include specific features, structures or characteristics, but not every embodiment must include these specific features, structures or characteristics. In addition, such expressions do not refer to the same embodiment. Furthermore, when describing specific features, structures or characteristics in conjunction with an embodiment, whether or not there is an explicit description, it has been shown that it is within the knowledge of those skilled in the art to combine such features, structures or characteristics into other embodiments.

[0052] In addition, certain words are used in the specification and subsequent claims to refer to specific components or parts. Those with ordinary knowledge in the relevant field should understand that manufacturers can use different nouns or terms to refer to the same component or part. This specification and subsequent claims do not use differences in names as a way to distinguish components or parts, but use differences in the functions of components or parts as the criteria for distinction. "Including" and "including" mentioned throughout the specification and subsequent claims are open-ended terms and should be interpreted as "including but not limited to". In addition, the word "connected" here includes any direct and indirect electrical connection means. Indirect electrical connection means include connection through other devices.

[0053] Before explaining the embodiment, it is necessary to first define the basic concepts in the intersatellite link switching strategy as follows. This definition is only used to explain an embodiment of the present invention and is not limited to the present invention and this embodiment:

[0054] (1) Defining the intersatellite link topology model of a time-varying network The constellation network topology of the tth time slot is represented by an undirected graph G t =(S,E t ) description, where S = {s i |1≤si ≤N} means there are N satellite nodes in the large-scale satellite constellation network, s i represents the i-th satellite node; represents the inter-satellite link in a large-scale constellation network, e ij =1 indicates satellite node s i and j There is an inter-satellite link between the two satellite nodes, otherwise there is no inter-satellite link between the two satellite nodes.

[0055] (2) Define the inter-satellite visibility of a large-scale satellite constellation network as a three-dimensional matrix of N×N×T in represents the satellite s at time t i and j Visible, otherwise the two satellite nodes are not visible at this time.

[0056] (3) Define satellite node s i Establish a communicative intersatellite link e with satellite node sj i The time of j is establish(e ij ), disconnect the communicative intersatellite link e ij The moment of remove(e ij ), and satisfies establish(e ij ),remove(e ij )∈[t s ,t e ].

[0057] Figure 1 An inter-satellite link packet switching simulation method based on a data exchange matrix provided by an embodiment of the present invention is shown, comprising the following steps:

[0058] S101: According to the visible relationship matrix between all satellite nodes in the satellite constellation network, obtain the topological snapshot of the inter-satellite link in each time interval; and configure the satellite node transponder quantity constraint and the constellation network topology connectivity constraint for the inter-satellite link switching process. That is, in this step S101, the large-scale inter-satellite link time-varying network topology is divided into a series of topological snapshots according to a certain time interval, and according to the connectivity requirements of different satellite transponder quantities and inter-satellite link establishment / disconnection, the inter-satellite link switching process is further added with relevant constraints.

[0059] See also Figure 2 In an optional implementation, step S101 specifically includes:

[0060] S110: Calculate the visible relationship three-dimensional matrix of all satellite nodes in the satellite constellation network within the entire period, and obtain the inter-satellite link topology snapshot within each time interval based on the visible relationship three-dimensional matrix. In the specific implementation, STK (Satellite Tool Kit) is used to calculate the visible relationship three-dimensional matrix of all satellite nodes in the large-scale satellite constellation network within the entire period T. Then, we can obtain the snapshot of the intersatellite link topology in each time interval. The intersatellite visibility relationship in the tth time interval is an N×N two-dimensional matrix

[0061] Among them, 1≤i≤N,1≤j≤N,

[0062] S120: setting a satellite node transponder quantity constraint that the maximum number of intersatellite links that can be established by a single satellite node does not exceed the number of transponders that can be used for intersatellite link establishment; that is, providing corresponding constraint conditions for the intersatellite link switching process by adding the satellite node transponder quantity constraint; specifically, the constraint expression of the satellite node transponder quantity constraint is:

[0063] Σ j∈V e ij ≤cnt trans ;

[0064] Among them, when e ij =1 indicates satellite node s i and satellite nodes j There is an intersatellite link between trans For a single satellite node s i The number of transponders that can be used to establish intersatellite links. i and j are satellite node numbers.

[0065] S130: Set the constellation network topology connectivity constraint that there is at least one reachable path between any pair of satellite nodes in the satellite constellation network. To ensure the connectivity of the large-scale satellite constellation network during inter-satellite link switching, that is, there is at least one reachable path between any pair of satellite nodes in the network, this can be achieved by first calculating the set of inter-satellite links E in the entire satellite constellation network after removing c inter-satellite links. r , and then calculate the adjacency matrix A after removing the above intersatellite links r , and finally calculate the intersatellite reachability matrix B at this time r ; Specifically, the constraint expression of the constellation network topology connectivity constraint is:

[0066]

[0067]

[0068]

[0069] Among them, E r A is the set of intersatellite links in the entire network after c intersatellite links are removed. r is the adjacency matrix after removing c intersatellite links, B r is the intersatellite reachability matrix when the link is removed, remove(e ij ) is to disconnect the communicative intersatellite link e ij moment, N represents the number of satellite nodes in the satellite constellation network.

[0070] S102: Obtain an intersatellite link network topology bipartite graph according to the intersatellite link target set calculated based on the adjacent topology snapshots and the satellite node set corresponding to their links; and based on the network topology bipartite graph, analyze and calculate the intersatellite link switching groups and the link break time series and link establishment time series that satisfy the satellite node transponder quantity constraint and the constellation network topology connectivity constraint; wherein the intersatellite link target set is the union of the first intersatellite link set and the second intersatellite link set, the first intersatellite link set is the intersatellite link set dismantled by the first topology snapshot, the second intersatellite link set is the intersatellite link set newly established by the second topology snapshot, and the first topology snapshot and the second topology snapshot are two adjacent topology snapshots.

[0071] In this embodiment, the adjacent first topology snapshot G k and the second topology snapshot G k+1 For specific implementation, see Figure 3 , the obtaining of the inter-satellite link network topology bipartite graph according to the inter-satellite link target set and the satellite node set corresponding to the link calculated based on the adjacent topology snapshots comprises:

[0072] S210: Calculate the common intersatellite links in two adjacent topology snapshots; in this embodiment, the adjacent intersatellite link topology snapshots G obtained in step S110 are used. k and G k+1 As input, the common intersatellite link E in two adjacent topology snapshots is calculated based on the following formula c :

[0073] E c =E k ∩E k+1 .

[0074] S220: Calculate, based on the common inter-satellite links, a first inter-satellite link set removed by a first topology snapshot in an adjacent topology snapshot, and a second inter-satellite link set newly established by a corresponding second topology snapshot in an adjacent topology snapshot; specifically, calculate the first topology snapshot G based on the following formula: k The first intersatellite link set E to be removed reand G k+1 The newly established second intersatellite link set E es :

[0075] E re =E k -E c ;

[0076] E es =E k+1 -E c .

[0077] S230: Merge the first inter-satellite link set and the second inter-satellite link set to obtain an inter-satellite link target set, and obtain an inter-satellite link network topology bipartite graph based on the inter-satellite link target set and its corresponding satellite node set. In combination with the above example, a new inter-satellite link network topology bipartite graph can be calculated based on the following formula:

[0078] G m =(S re ∪S es ,E re ∪E es )=(S m ,S m );

[0079] Among them, S re is the first intersatellite link set E re The corresponding satellite node set, S es is the second intersatellite link set E es The corresponding satellite node set.

[0080] Further, the analyzing and calculating, based on the network topology bipartite graph, the intersatellite link switching grouping and the link disconnection time sequence and link establishment time sequence that satisfy the satellite node transponder quantity constraint and the constellation network topology connectivity constraint comprises:

[0081] S240: Generate a plurality of independent subgraph sequences of the inter-satellite link network topology bipartite graph; this embodiment specifically generates an inter-satellite link network topology bipartite graph G m f independent subgraph sequences g h , and meet the following conditions:

[0082]

[0083] It is then necessary to determine the large-scale constellation inter-satellite link switching grouping. The basic principle is to minimize the time for dismantling and re-building the link for topological state switching. The inter-satellite links between different groups can be switched in parallel, and the inter-satellite links in each group are switched asynchronously. The steps are as follows:

[0084] S250: Initialize the number M of independent intersatellite link subgraphs contained in each group in the topology switching group, where M=f-1, and f is the number of all independent subgraph sequences; after step S250, it is also necessary to determine whether M is greater than 0. If so, proceed to the subsequent step S260, otherwise proceed to the subsequent step S300.

[0085] S260: When M>0, all target switching groups of M independent subgraphs are selected from all the independent subgraph sequences; that is, the intersatellite link network topology bipartite graph G is calculated. m The total independent subgraph sequence g h Select all combinations R of M independent subgraphs, the number of which is In this embodiment, each target switching group is defined as SG l , and it satisfies:

[0086]

[0087] S270: Determine whether the newly created intersatellite link of the target switching group meets the satellite node transponder quantity constraint, and whether the topology of the target switching group after the removal of the intersatellite link meets the constellation network topology connectivity constraint; the specific judgment rules are as follows:

[0088]

[0089] Conn(E k -E re )=1,E re ∈E l .

[0090] If the above rules are met, the process proceeds to the subsequent step S280 . Otherwise, it is necessary to reset M=M-1 and return to repeat steps S260 to S270 until the process proceeds to the subsequent step.

[0091] S280: If the conditions are met, the disconnection time of the intersatellite link in the corresponding target switching group and the time to re-establish the new link are calculated; in specific implementation, the corresponding disconnection time t can be calculated based on the following formula: re Time t to rebuild the chain with the new chain es :

[0092]

[0093]

[0094] Among them, t d Indicates the intersatellite link establishment time.

[0095] S290: Bipartite the intersatellite link network topology graph G mThe subgraph after removing the target switching group SG is reset, and M is reset to M=M-1, and the process returns to repeat steps S260 to S290.

[0096] S300: When M=0, calculate and save the intersatellite link switching group SG and the corresponding disconnection time sequence T of the disconnection time re The link building time series T re-established by the new link es ; The corresponding calculation results will be used as input for the subsequent data exchange matrix containerization simulation method.

[0097] This embodiment adopts an inter-satellite link group switching strategy to ensure the connectivity of a large-scale constellation network during inter-satellite link switching, reduce the routing convergence time during the topology switching process, and avoid the degradation of network performance.

[0098] S103: Generate several satellite node containers according to the satellite constellation time-varying network intersatellite link topology model, and create a data exchange matrix connected to the virtual network cards of the several satellite node containers; use the intersatellite link switching group, link break time series and link establishment time series as the virtual network port parameters of the data exchange matrix, and update the whole network adjacency table stored in the data exchange matrix at a predetermined time interval to simulate the constellation network link topology switching process. In specific implementation, this embodiment can use container technology and Linux virtual network device veth-pair to simulate the satellite nodes and intersatellite links of a large-scale constellation network, calculate the intersatellite link switching group SG obtained according to the above steps, and update the link establishment / disconnection time series T es and T re As network parameter input, high-fidelity simulation of link topology switching process of large-scale constellation network can be realized.

[0099] See also Figure 4 In an optional implementation, the generating of a plurality of satellite node containers through the satellite constellation time-varying network inter-satellite link topology model and the creation of a data exchange matrix connected to the virtual network cards of the plurality of satellite node containers includes:

[0100] S310: Generate a number of satellite node containers according to the satellite constellation time-varying network inter-satellite link topology model; wherein the satellite constellation time-varying network inter-satellite link topology model of this embodiment is Generate |S| satellite node containers.

[0101] S320: Create a one-hop link layer connection between the virtual network cards of the satellite node containers, create a data exchange matrix, and establish a layer 2 Ethernet link between each of the virtual network cards and the data exchange matrix. In combination with the above example, step S320 specifically creates a one-hop link layer connection between the virtual network cards of |S| satellite node containers, and uses veth-pair to establish a layer 2 Ethernet link between each container satellite node virtual network card and the data exchange matrix, such as Figure 6 shown.

[0102] Further, using the intersatellite link switching grouping, link disconnection time sequence and link establishment time sequence as virtual network port parameters of a data exchange matrix to simulate the constellation network link topology switching process includes:

[0103] S330: Using the intersatellite link switching group, link disconnection time sequence and link establishment time sequence as virtual network port parameters of the data exchange matrix to perform real-time response of link disconnection, reconstruction and maintenance status; Figure 7 As shown, in step S330, the intersatellite link switching group SG and the link disconnection time sequence T obtained in the aforementioned step S300 are re And the chain building time series T es Set the virtual network port parameters on the data exchange matrix side to complete real-time response to link disconnection, reconstruction and maintenance status.

[0104] S340: When every minimum time interval Δt, the adjacency matrix of the actual network topology connection relationship at the current moment is updated (the adjacency table is used instead of the adjacency matrix to optimize the storage overhead) to input the data exchange matrix to simulate the constellation network link topology switching process. At this time, the data exchange matrix simultaneously updates the internally stored full network adjacency table to achieve high-fidelity simulation of the dynamic constellation network topology, such as Figure 8 That is, this embodiment can support the efficient simulation of ultra-large-scale network scenarios within a limited time, effectively reduce the system simulation cost, and improve the simulation efficiency of the constellation network.

[0105] In summary, the intersatellite link group switching simulation method based on the data exchange matrix provided by the present invention realizes the pre-scheduling of intersatellite link switching based on the intersatellite link group switching strategy of the bipartite graph, and overcomes the problem of long time required for stable establishment of laser intersatellite links in the current satellite communication system by executing the disconnection / reconstruction process of the laser intersatellite link in the minimum group in parallel, realizes efficient and fast intersatellite link switching, reduces the routing convergence time in the topology state switching process, and effectively avoids the degradation of constellation network performance and service interruption; through the intersatellite link topology containerization simulation method based on the data exchange matrix, a large-scale satellite constellation network link simulation environment is constructed for the first time to solve the problem of high-fidelity reproduction of the laser intersatellite link switching process, and make up for the shortcomings of the traditional intersatellite link switching simulation based on mathematical calculation that cannot meet the real-time response link disconnection and reconstruction network requirements; a data exchange matrix link topology simulation method is also provided to optimize the storage overhead of large-scale dynamic constellation network topology simulation, support the completion of efficient simulation of ultra-large-scale network scenarios within a limited time, effectively reduce the system simulation overhead, and improve the simulation efficiency of the constellation network.

[0106] The method according to the present invention can be implemented on a computer as a computer-implemented method, or implemented in dedicated hardware, or implemented in a combination of the two. The executable code or its part for the method according to the present invention can be stored on a computer program product. Preferably, the computer program product comprises a non-temporary program code component that is stored on a computer-readable medium so as to perform the method according to the present invention when the program product is executed on a computer.

[0107] In a preferred embodiment, the computer program comprises computer program code means adapted to perform all the steps of the method according to the invention when the computer program is run on a computer.Preferably, the computer program is embodied on a computer readable medium.

[0108] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for simulating intersatellite link packet switching based on a data exchange matrix, characterized in that: Includes steps: According to the visible relationship matrix between all satellite nodes in the satellite constellation network, the topological snapshot of the inter-satellite link in each time interval is obtained; and the satellite node transponder quantity constraint and the constellation network topology connectivity constraint are configured for the inter-satellite link switching process; According to the intersatellite link target set calculated based on the adjacent topology snapshots and the satellite node set corresponding to the link, a bipartite graph of the intersatellite link network topology is obtained; and based on the network topology bipartite graph, the intersatellite link switching grouping and the link breaking time sequence and the link establishing time sequence that satisfy the satellite node transponder quantity constraint and the constellation network topology connectivity constraint are analyzed and calculated; wherein the intersatellite link target set is a collection of a first intersatellite link set and a second intersatellite link set, the first intersatellite link set is a set of intersatellite links dismantled by a first topology snapshot, the second intersatellite link set is a set of intersatellite links newly established by a second topology snapshot, and the first topology snapshot and the second topology snapshot are two adjacent topology snapshots; According to the satellite constellation time-varying network intersatellite link topology model, a number of satellite node containers are generated, and a data exchange matrix connected to the virtual network cards of the several satellite node containers is created; the intersatellite link switching group, the link breaking time series and the link establishing time series are used as virtual network port parameters of the data exchange matrix, and the whole network adjacency table stored in the data exchange matrix is ​​updated at a predetermined time interval to simulate the constellation network link topology switching process.

2. The method for simulating intersatellite link packet switching based on a data exchange matrix according to claim 1, characterized in that: The method comprises obtaining a topological snapshot of the inter-satellite links in each time interval according to a visible relationship matrix between all satellite nodes in the satellite constellation network; And the satellite node transponder quantity constraint and constellation network topology connectivity constraint are configured for the intersatellite link switching process, including: Calculating the visible relationship three-dimensional matrix of all satellite nodes in the satellite constellation network within the entire period, and obtaining an inter-satellite link topology snapshot within each time interval based on the visible relationship three-dimensional matrix; Set a satellite node transponder number constraint that the maximum number of intersatellite links that can be established by a single satellite node does not exceed the number of transponders that can be used to establish intersatellite links; A constellation network topology connectivity constraint is set that there is at least one reachable path between any pair of satellite nodes in the satellite constellation network.

3. The method for simulating intersatellite link packet switching based on a data exchange matrix according to claim 2, characterized in that: The constraint expression of the satellite node transponder quantity constraint is: Σ j∈V and ij ≤cnt trans ; Among them, when e ij =1 indicates satellite node s i and satellite nodes j There is an intersatellite link between trans For a single satellite node s i The number of transponders that can be used to establish intersatellite links. i and j are satellite node numbers.

4. The method for simulating intersatellite link packet switching based on a data exchange matrix according to claim 2, characterized in that: The constraint expression of the constellation network topology connectivity constraint is: Among them, E r A is the set of intersatellite links in the entire network after c intersatellite links are removed. r is the adjacency matrix after removing c intersatellite links, B r is the intersatellite reachability matrix when the link is removed, remove(e ij ) is to disconnect the communicative intersatellite link e ij moment, N represents the number of satellite nodes in the satellite constellation network.

5. The method for simulating intersatellite link packet switching based on a data exchange matrix according to claim 1, characterized in that: The step of obtaining a bipartite graph of the inter-satellite link network topology according to the inter-satellite link target set and the satellite node set corresponding to the link calculated based on the adjacent topology snapshots comprises: Calculating common inter-satellite links in two adjacent topology snapshots; Calculate, based on the common intersatellite links, a first intersatellite link set removed by a first topology snapshot in the adjacent topology snapshots and a second intersatellite link set newly established by a corresponding second topology snapshot in the adjacent topology snapshots; The first intersatellite link set and the second intersatellite link set are merged to obtain an intersatellite link target set, and based on the intersatellite link target set and its corresponding satellite node set, an intersatellite link network topology bipartite graph is obtained.

6. The method for simulating intersatellite link packet switching based on a data exchange matrix according to claim 5, characterized in that: The analyzing and calculating, based on the network topology bipartite graph, the inter-satellite link switching grouping and the link disconnection time sequence and link establishment time sequence that satisfy the satellite node transponder quantity constraint and the constellation network topology connectivity constraint comprises: Generating a plurality of independent subgraph sequences of the intersatellite link network topology bipartite graph; Initialize the number M of independent intersatellite link subgraphs contained in each group of the topology switching group, where M=f-1, and f is the number of all independent subgraph sequences; When M>0, all target switching groups of M independent subgraphs selected from all the independent subgraph sequences are calculated; Determine whether the newly created intersatellite link of the target switching group meets the satellite node transponder quantity constraint, and whether the topology of the target switching group after the intersatellite link is removed meets the constellation network topology connectivity constraint; If the conditions are met, the disconnection time of the intersatellite link in the corresponding target switching group and the time for re-establishing the new link are calculated; The intersatellite link network topology bipartite graph is set as a subgraph after removing the target switching group, and M is reset to M=M-1, and the step of calculating all switching groups of M independent subgraphs selected from all the independent subgraph sequences when M>0 is returned; When M=0, the intersatellite link switching group is calculated and saved, as well as the link disconnection time sequence of the corresponding disconnection time and the link establishment time sequence of the new link re-establishment.

7. The method for simulating intersatellite link packet switching based on a data exchange matrix according to claim 1, characterized in that: The method of generating a plurality of satellite node containers according to the satellite constellation time-varying network inter-satellite link topology model and creating a data exchange matrix connected to the virtual network cards of the plurality of satellite node containers includes: Generate a number of satellite node containers according to the satellite constellation time-varying network inter-satellite link topology model; A one-hop link layer connection is created between the virtual network cards of the plurality of satellite node containers, a data exchange matrix is ​​created, and a layer 2 Ethernet link is established between each of the virtual network cards and the data exchange matrix.

8. The method for simulating intersatellite link packet switching based on a data exchange matrix according to claim 7, characterized in that: The using the intersatellite link switching group, the link disconnection time sequence and the link establishment time sequence as virtual network port parameters of the data exchange matrix to simulate the constellation network link topology switching process includes: The intersatellite link switching group, the link disconnection time sequence and the link establishment time sequence are used as virtual network port parameters of the data exchange matrix to perform real-time response of link disconnection, reconstruction and maintenance status; At every minimum time interval, the actual network topology connection relationship adjacency matrix at the current moment is updated to input the data exchange matrix to perform constellation network link topology switching process simulation.

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