Method and system for optimizing low earth orbit satellite network handover based on named data networking

Abstract

The present application relates to a low-orbit satellite network switching optimization method and system based on a named data network, the system comprising: obtaining the number of orbital planes, the number of satellites in a single orbit and the topological connection relationship between satellites; obtaining a consumer access satellite set and a producer access satellite set that can provide services for consumers within the total service time; determining the average routing hop count between each consumer access satellite and the producer access satellite within its own service time slot; constructing a low-orbit satellite network switching optimization model with the minimum average routing hop count as the optimization target; solving the low-orbit satellite network switching optimization model based on the preset minimum hop count graph switching strategy to obtain the shortest path switching scheme. This makes the consumer side switch different access satellites while meeting the minimum average routing hop count constraint and selecting the shortest path, ensuring the minimum delay of the consumer during network communication.

Description

Technical Field

[0001] This invention belongs to the field of satellite network technology, and in particular relates to a method and system for optimizing handover of low-Earth orbit satellite networks based on named data networks. Background Technology

[0002] In recent years, with the accelerated commercialization of large-scale low-Earth orbit (LEO) constellations, the concept of satellite-based global internet services has gained widespread attention. LEO satellite systems can serve broadband access in remote areas and provide communication support for scenarios such as high-quality intercontinental video calls. However, due to the limited coverage time and extremely high orbital speeds of satellites, LEO networks still face many challenges. For example, Starlink satellites operate at approximately 28,080 km / h, providing continuous coverage of a specific ground area for only about 3 minutes, while users typically need to reselect their access satellite every 15 seconds. Traditional TCP / IP networks rely on additional technologies such as Mobile IP to handle frequent IP address changes, but these methods introduce additional latency and may require at least one round-trip time (RTT) for packet retransmission.

[0003] Named Data Networking (NDN), as a data-centric innovative architecture, significantly improves content retrieval efficiency by decoupling content from location and supporting in-network caching mechanisms. Research shows that deploying high-performance servers on Starlink satellites is technically feasible, with each satellite providing approximately 150 TB of storage capacity. Currently, the Starlink constellation has deployed over 6,000 satellites, with a total onboard storage capacity estimated at 900 PB, laying a solid foundation for building an NDN-based satellite network. Compared to the traditional TCP / IP architecture, NDN natively supports consumer mobility, enabling end-to-end transmission of uplink and downlink data streams without requiring redirection through ground stations. However, as the satellite fleet expands, the impact of consumers choosing different access satellites on inter-satellite routing becomes increasingly significant, and the choice of different access satellites also affects data recovery time.

[0004] Regarding satellite access selection, existing research mainly employs three evaluation metrics: Longest Remaining Service Time (LRST), Maximum Elevation (ME), and Maximum Number of Free Channels (MFC). LRST aims to reduce satellite handover frequency, ME focuses on improving link communication quality, and MFC is used to achieve network load balancing. Existing methods only consider single-hop performance and fail to fully account for the significant impact of multi-hop inter-satellite link (ISL) routing on system performance in large constellations.

[0005] With the mature application of inter-satellite link technology, recent research has begun to explore the impact of access satellite selection on inter-satellite routing. Location-Based Protocol (LBP) algorithms select satellites moving in the same direction as the ground station during initial access and maintain this direction of movement during subsequent handovers to reduce end-to-end latency jitter. Another approach is to jointly optimize access strategies and inter-satellite routing to reduce transmission latency. However, these methods are limited to optimization within a single time slot and cannot guarantee the continuous minimization of end-to-end latency throughout the entire communication session.

[0006] Furthermore, recent research advancements in NDN forwarding technology have highlighted the crucial role of access satellite selection. One existing forwarding alert mechanism retransmits unresponsive packets of interest to preceding satellites; another introduces a dynamic decision-making mechanism based on the forwarding alert mechanism, intelligently determining whether to enable the forwarding alert function based on path overlap rate. However, the effectiveness of forwarding alerts is highly dependent on the selection of access satellites.

[0007] In summary, most existing research focuses on forwarding strategies in the context of giant low-Earth orbit satellites based on named data networks, or on handover strategies under the TCP / IP architecture that use single-hop performance as a handover metric. Few studies consider the impact of switching between different access satellites on network performance on the consumer side. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a method and system for optimizing low-Earth orbit satellite network handover based on named data networks.

[0009] The technical solution adopted in this invention is:

[0010] Firstly, a low-Earth orbit satellite network handover optimization method based on named data networks is provided, including:

[0011] Obtain the number of orbital planes, the number of satellites in a single orbit, and the topological connections between satellites in a low-Earth orbit satellite network based on a named data network;

[0012] When consumers access low-Earth orbit satellite networks to communicate with producer networks, the set of consumer access satellites that can provide services to consumers during the total service time, and the set of producer access satellites for producers during the total service time are obtained.

[0013] Based on the consumer access satellite set and the producer access satellite set, determine the average number of routing hops between each consumer access satellite and the producer access satellite within its own service time slot;

[0014] By minimizing the average number of routing hops as the optimization objective, a low-Earth orbit satellite network handover optimization model is constructed.

[0015] Based on the preset minimum hop count graph switching strategy, the low-Earth orbit satellite network switching optimization model is solved to obtain the shortest path switching scheme for consumers when switching satellites.

[0016] Furthermore, the number of orbital planes, the number of satellites in a single orbit, and the topological connections between satellites in the low-Earth orbit satellite network based on the named data network are obtained, including:

[0017] Obtain the number of orbital planes of a low-Earth orbit satellite network based on a named data network. and the number of satellites in each orbit ;

[0018] Based on the pre-defined +Grid topology connection relationship, the connection relationship between each satellite and its adjacent satellites in the same orbit, as well as its relationship with its adjacent satellites in adjacent orbits, is determined.

[0019] Furthermore, acquiring the set of consumer access satellites that can provide services to consumers during the total service time, and the set of producer access satellites for producers during the total service time, includes:

[0020] Obtaining consumer service time Service time is determined according to the principle of constant time interval. Divided into Each service slot , It is a positive integer;

[0021] The total service time is obtained based on the preset consumer satellite handover strategy and the shortest path routing rule. The collection of consumer access satellites that can provide services to consumers;

[0022] The total service time is obtained based on the known producer satellite switching sequence. The producers of internal producers access the satellite set.

[0023] Furthermore, based on the consumer access satellite set and the producer access satellite set, the average number of routing hops between each consumer access satellite and the producer access satellite within its own service time slot is determined, including:

[0024] Based on the consumer access satellite set and the producer access satellite set, determine Consumer access to satellite at any time and producers access satellite , Access to satellite for producers During the service break, Consumers access satellite Indicates that it is located at the th The first orbit One satellite, producer access satellite Indicates that it is located at the th The first orbit One satellite;

[0025] Calculated Consumer access to satellite at any time Access to satellites by producers Inter-satellite route hop count Inter-satellite route hop count The expression is:

[0026] ;

[0027] in, This indicates the preset deviation jump coefficient;

[0028] Based on inter-satellite route hop count Build consumer access satellite Its own service slot Internal and producer access satellite Average number of route hops between Average number of route hops The expression is:

[0029] ;

[0030] in, Indicates consumer access to satellite The service start time slot, Indicates consumer access to satellite During the service break, , .

[0031] Furthermore, using minimizing the average routing hop count as the optimization objective, a low-Earth orbit satellite network handover optimization model is constructed, including:

[0032] To minimize the average number of route hops As the optimization objective, the expression for the first constraint condition is constructed as follows:

[0033] ;

[0034] Consumer access to satellite Preset single-satellite service threshold The expression for the second constraint is constructed as follows:

[0035] ;

[0036] Determine consumer access to satellite Subsequent consumer access satellites The number of consecutive satellite route hops was calculated. Based on a preset consecutive access hop count threshold The expression for the third constraint is constructed as follows:

[0037] ;

[0038] based on and The expression for the fourth constraint is constructed as follows:

[0039] ;

[0040] Based on the expressions of the first, second, third, and fourth constraints, an optimization model for low-Earth orbit satellite network handover is constructed.

[0041] Furthermore, the preset minimum hop count graph switching strategy includes:

[0042] The minimum hop count graph is obtained based on the minimum hop count graph mapping algorithm. The nodes in the minimum hop count graph are the satellites in the consumer access satellite set and the producer access satellite set. The connectivity between nodes is determined by whether the service end time slot of one satellite falls within the service time slot of another satellite.

[0043] Based on average route hops Obtain the edge weight of the directed edge between two connected nodes. edge weight The expression is ;

[0044] Select directed edges whose weights satisfy the first, second, third, and fourth constraints as feasible directed edges;

[0045] Based on the feasible directed edges and their corresponding weights, the minimum hop count graph is labeled to obtain the minimum hop count directed weighted graph.

[0046] Furthermore, based on a pre-defined minimum hop count graph handover strategy, the low-Earth orbit satellite network handover optimization model is solved to obtain the shortest path handover scheme for consumers during satellite handover, including:

[0047] Based on the directed weighted graph with minimum hop count, the Dijkstra shortest path algorithm is used to obtain the feasible directed path for consumers when switching satellites;

[0048] Calculate the sum of edge weights for all feasible directed edges of each feasible directed path;

[0049] Choose the feasible directed path with the smallest edge weight as the shortest path switching scheme.

[0050] Secondly, a low-Earth orbit satellite network handover optimization system based on a named data network is provided, including:

[0051] The satellite network data acquisition module is used to acquire the number of orbital planes, the number of satellites in a single orbit, and the topological connections between satellites in a low-Earth orbit satellite network based on a named data network.

[0052] The access satellite acquisition module is used to acquire the set of consumer access satellites that can provide services to consumers during the total service time, and the set of producer access satellites for producers during the total service time, when consumers access the low-Earth orbit satellite network to communicate with the producer network.

[0053] The routing hop count determination module is used to determine the average routing hop count between each consumer access satellite and the producer access satellite within its own service time slot, based on the consumer access satellite set and the producer access satellite set.

[0054] The model building module is used to construct a low-Earth orbit satellite network handover optimization model with minimizing the average routing hop count as the optimization objective.

[0055] The shortest path switching module is used to solve the low-Earth orbit satellite network switching optimization model based on the preset minimum hop count switching strategy, so as to obtain the shortest path switching scheme for consumers when switching satellites.

[0056] The beneficial effects achieved by this invention are as follows:

[0057] This paper obtains the number of orbital planes, the number of satellites in a single orbit, and the topological connections between satellites in a low-Earth orbit (LEO) satellite network based on a named data network. When a consumer accesses the LEO satellite network and communicates with a producer network, the paper obtains the set of consumer access satellites that can provide services to the consumer during the total service time, and the set of producer access satellites that can provide services to the producer during the total service time. Based on the consumer access satellite set and the producer access satellite set, the paper determines the average number of hops between each consumer access satellite and a producer access satellite within its own service time slot. Using minimizing the average number of hops as the optimization objective, a LEO satellite network handover optimization model is constructed. Based on a pre-defined minimum hop count graph handover strategy, the LEO satellite network handover optimization model is solved to obtain the shortest path handover scheme for consumers during satellite handover. The paper constructs an LEO satellite network handover optimization model with minimizing the average number of hops as the optimization objective and provides a pre-defined minimum hop count graph handover strategy. This ensures that when consumers switch between different access satellites, they meet the constraint of minimizing the average number of hops while selecting the shortest path, guaranteeing minimal latency for consumers during network communication. Attached Figure Description

[0058] Figure 1 This is a flowchart of the low-Earth orbit satellite network handover optimization method based on named data networks according to the present invention;

[0059] Figure 2 This is a schematic diagram of consumer access satellite handover in the 3×3 low-Earth orbit satellite network of the present invention;

[0060] Figure 3 This is a schematic diagram illustrating the consumer access to the satellite set and service time slots according to the present invention;

[0061] Figure 4 This is the directed weighted graph with the minimum hop count of this invention;

[0062] Figure 5 This is a structural diagram of the low-Earth orbit satellite network handover optimization system based on the named data network of the present invention. Detailed Implementation

[0063] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0064] Before describing the low-Earth orbit satellite network handover optimization method and system based on named data network of the present invention, the handover and forwarding strategies of existing low-Earth orbit satellite networks will be described first.

[0065] The specific details of the switching strategy are as follows;

[0066] In the scenario of a giant low-Earth orbit satellite constellation, multiple satellites can simultaneously cover the same geographical area. How to select the optimal access satellite from multiple visible satellites is called the satellite access strategy problem under multi-satellite coverage. Early satellite access strategies mainly used three indicators as basic access criteria: Longest Remaining Service Time (LRST), Maximum Elevation (ME), and Maximum Number of Free Channels (MFC).

[0067] Among them, LRST aims to reduce satellite handover frequency, ME focuses on improving link communication quality, and MFC is used to achieve network load balancing; according to the number of access criteria used, early research can be divided into single-attribute handover strategies and multi-attribute handover strategies.

[0068] Single-attribute switching predicts the remaining service time of overhead satellites by acquiring the user's own GPS information and satellite motion information in real time, thereby selecting the access satellite with the longest remaining service time;

[0069] Multi-attribute handover often employs a comprehensive weighted approach. For example, a Quality of Experience (QoE) driven intelligent handover mechanism selects the satellite to be handed over based on predicted service time and communication channel resources; information entropy is used to weight the three criteria for satellite handover, and the satellite with the highest weight is selected for handover; graph theory can also be applied to satellite access strategies. Existing LEO satellite handover frameworks based on directed graphs flexibly integrate multiple handover criteria by setting link weights to achieve optimization goals such as minimizing the number of handovers; an existing multi-period load balancing (MSLB) handover strategy constructs a handover sequence graph and solves for the shortest path to achieve effective load balancing of the LEO satellite network while ensuring user communication quality.

[0070] Early research, while exploring various methodologies, primarily relied on LRST, ME, and MFC as access criteria, with limited consideration of the impact of satellite-to-ground access strategies on inter-satellite routing. However, with increasing constellation size and the activation of inter-satellite links, users selecting unsuitable access satellites can lead to significant differences in inter-satellite routing. For example, Location Based Protocol (LBP) algorithms select satellites moving in the same direction as the ground station during initial access and maintain this direction of movement during subsequent handovers to reduce end-to-end latency jitter. Alternatively, another innovative approach involves jointly optimizing access strategies and inter-satellite routing to reduce transmission latency. However, these methods are limited to optimization within a single time slot and cannot guarantee the continuous minimization of end-to-end latency throughout the entire communication session.

[0071] The specific details of the forwarding strategy are as follows:

[0072] In NDN, the problem where a consumer moves after a request is sent but before the data is returned, thereby changing the access satellite and causing the returned data packets to fail to be successfully delivered to the consumer, is called the consumer mobility problem.

[0073] NDN offers a data-centric architecture and a pull-based communication model, allowing for simple retransmission requests after a consumer switches satellites; however, this basic mobility support introduces additional latency and reduces future request rates because timeouts are treated as a sign of network congestion.

[0074] Consumer repeaters can detect link changes and retransmit interest packets that were not received before the handover. Based on this, an existing forwarding hint (FH) mechanism immediately retransmits all unmet interest packets to the original access satellite before the handover. An optimal retransmission strategy further dynamically decides whether to use forwarding hint based on the path overlap before and after the handover: some interest packets are redirected to the original access satellite through forwarding hint, while the rest are directly forwarded to the producer.

[0075] However, the effectiveness of forwarding prompts is highly dependent on the number of hops between the two access satellites. If the access satellites are not selected properly, such as if the number of hops is too high, the effect may be greatly reduced.

[0076] Based on the existing handover and forwarding strategies of low-Earth orbit satellite networks, the improvements of the low-Earth orbit satellite network handover optimization method and system based on named data networks of the present invention are illustrated through the following embodiments.

[0077] like Figure 1 As shown, this embodiment of the invention provides a low-Earth orbit satellite network handover optimization method based on a named data network, including:

[0078] 101. Obtain the number of orbital planes, the number of satellites in a single orbit, and the topological connections between satellites in a low-Earth orbit satellite network based on a named data network;

[0079] In this embodiment, the number of orbital planes of a low-Earth orbit satellite network based on a named data network is obtained. and the number of satellites in each orbit ;

[0080] Based on the pre-defined +Grid topology connection relationship, the connection relationship between each satellite and its adjacent satellites in the same orbit, as well as its relationship with its left and right adjacent satellites in adjacent orbits, is determined.

[0081] like Figure 2The diagram shown illustrates the consumer access satellite handover process for a 3×3 low-Earth orbit satellite network. Each satellite can establish connections with four other satellites: two satellites in the same orbit preceding and following each other, and satellites in adjacent orbits to the left and right. The specific satellite designations are as follows: This represents the second satellite in the first orbit. To simplify the analysis, it is assumed that the inter-satellite single-hop link delay is constant. In the initial state, the consumer accesses the satellite... Producers access satellite According to the shortest path routing rule, the forwarding path of the interest packet before the switch was: .exist Figure 2 In the diagram, solid yellow arrows indicate the routing path for interest packets before the switchover, solid green arrows indicate data routing, dashed green arrows indicate data loss, and solid red arrows indicate the routing path for interest packets after the switchover. (The text in red text is incomplete and likely refers to further details about the routing path.) , , This indicates candidate satellites for consumer access.

[0082] It should be noted that in this invention, "consumer" actually refers to the satellite communication terminal held by the user, and "producer" actually refers to the satellite communication equipment that provides communication services. For ease of description, "consumer" and "producer" are used to replace "terminal" and "equipment" in this invention.

[0083] 102. When consumers access the low-Earth orbit satellite network and communicate with the producer network, obtain the set of consumer access satellites that can provide services to consumers during the total service time, and the set of producer access satellites for producers during the total service time.

[0084] In this embodiment, the consumer's service time is obtained. The total service time is calculated based on the principle of constant time interval. Divided into Each service slot , It is a positive integer; in practice, the connection between the consumer and the access satellite lasts for a maximum of a few minutes, therefore, the time granularity can be set to 1 second, one service slot. It can be 1 second or more seconds;

[0085] Access Satellite Set The expression is:

[0086] ;

[0087] in, Indicates that it is located at the th The first orbit One satellite, express The service start time slot, express During the service break, , ; and The determination is made using a simplified general perturbation model (SGP4), two satellite array elements, and the coordinates of the area where the consumer is located;

[0088] The total service time is obtained based on the preset consumer satellite handover strategy and the shortest path routing rule. The system includes a set of consumer access satellites that can provide services to consumers; due to the highly dynamic nature of low-Earth orbit satellites, consumers need to periodically perform switching operations; combined with... Figure 2 The description states that during this process, data packets transmitted along the original path may be lost, but these data may be cached at intermediate nodes and have recovery potential; the consumer access satellite set that can provide services to consumers is included. ;

[0089] ;

[0090] Figure 3 The diagram shown illustrates the consumer access to the satellite array and service time slots.

[0091] The switching sequences of producers are considered known, and the total service time is obtained based on the known producer satellite switching sequences. The producers of internal producers access the satellite set.

[0092] 103. Based on the consumer access satellite set and the producer access satellite set, determine the average number of routing hops between each consumer access satellite and the producer access satellite within its own service time slot;

[0093] In this embodiment, combined with Figure 3 When the current consumer accesses the satellite service slot in to At the end of the period, At the start of a time slot, a handover operation is performed, and a satellite is selected from the set of satellites accessible to the consumer for access. This process is repeated each time the service of the current consumer accessing a satellite ends, until the total service time is up. Until the end;

[0094] Assuming the average one-hop latency of the inter-satellite link is Milliseconds represent the round-trip time. It can be represented as:

[0095] ;

[0096] This represents the time required for a satellite to parse, process, and forward data packets. The minimum hop count path guarantees the fewest intermediate satellites, thus resulting in the minimum satellite processing latency. and These represent the uplink and downlink transmission delays, respectively, with uplink and downlink transmission delays ranging from 1.8ms to 3.6ms. The inter-satellite link one-hop delay ranges from 1.7ms to 10ms, and the average number of hops for inter-satellite links is also mentioned. Around 11.48;

[0097] The above analysis shows that the propagation delay of inter-satellite link (ISL) is the determining factor. The dominant factor is the size; if we assume for the time being that the single-hop propagation delay of the intra-orbit and inter-orbit links is equal, then the end-to-end delay is only proportional to the number of hops; however, in actual constellations, the distance between ISLs on the same orbit is constant and the delay is basically unchanged, while the geometric distance between ISLs on different orbits changes periodically with the relative position of the orbits, and their single-hop delay is generally higher than that of ISLs on the same orbit.

[0098] Therefore, to simplify modeling, latency differences can be converted into hop count costs, and a preset hop count coefficient can be introduced for off-track hop counts. ( ), in equivalent hop count Instead of the actual number of hops h, it provides a unified measure of latency performance for different paths;

[0099] Based on the consumer access satellite set and the producer access satellite set, determine Consumer access to satellite at any time and producers access satellite , Access to satellite for producers During the service break, Consumers access satellite Indicates that it is located at the th The first orbit One satellite, producer access satellite Indicates that it is located at the th The first orbit One satellite;

[0100] Calculated Consumer access to satellite at any time Access to satellites by producers Inter-satellite route hop count Inter-satellite route hop count The expression is:

[0101] ;

[0102] Due to the asynchronous switching between producers and consumers, consumers connect to satellites. During this period, the producer may have switched to other satellites; therefore, based on the number of inter-satellite routing hops... Build consumer access satellite Its own service slot Internal and producer access satellite Average number of route hops between Average number of route hops The expression is:

[0103] .

[0104] 104. Using minimizing the average number of routing hops as the optimization objective, a low-Earth orbit satellite network handover optimization model is constructed.

[0105] In this embodiment, the goal is to minimize the average number of route hops. As the optimization objective, the expression for the first constraint condition is constructed as follows:

[0106] ;

[0107] The first constraint is to minimize the average number of routing hops between consumers and producers within time T.

[0108] Consumer access to satellite Preset single-satellite service threshold The expression for the second constraint is constructed as follows:

[0109] ;

[0110] The existing Starlink satellites are scheduled to switch every 15 seconds, therefore The value can be set to 15s;

[0111] Forwarding interest packets to previously connected satellites can speed up the recovery of packets lost during handover. However, if the number of routing hops between consecutively accessed satellites is too high, the recovery process will still take a long time. To mitigate this impact, the consumer's access satellite needs to be determined. Subsequent consumer access satellites The number of consecutive satellite route hops was calculated. Based on a preset consecutive access hop count threshold , Increasing this value will increase the number of available paths and decrease the shortest weighted path value; however, when... When the value is too large, the latency required to recover from packet loss during handover will also increase. Therefore, an appropriate value can be selected through pre-training. Values, for example The expression for the third constraint is constructed as follows:

[0112] ;

[0113] based on and Having obtained the satellite's orbital constraints, the expression for the fourth constraint is constructed as follows:

[0114] ;

[0115] Based on the expressions of the first, second, third, and fourth constraints, an optimization model for low-Earth orbit satellite network handover is constructed.

[0116] 105. Based on the preset minimum hop count graph switching strategy, the low-orbit satellite network switching optimization model is solved to obtain the shortest path switching scheme for consumers during satellite switching.

[0117] In this embodiment, the principle of the preset minimum hop count graph switching strategy is as follows:

[0118] The minimum hop count graph is obtained based on the minimum hop count graph mapping algorithm. The nodes in the minimum hop count graph are the satellites in the consumer access satellite set and the producer access satellite set. The connectivity between nodes is determined by whether the service end time slot of one satellite falls within the service time slot of another satellite.

[0119] Based on average route hops Obtain the edge weight of the directed edge between two connected nodes. edge weight The expression is ;

[0120] Select directed edges whose weights satisfy the first, second, third, and fourth constraints as feasible directed edges;

[0121] Based on the feasible directed edges and their corresponding edge weights, the minimum hop count graph is labeled to obtain the minimum hop count directed weighted graph.

[0122] like Figure 4 The diagram shown is a directed weighted graph with minimum hop count. Figure 4 In this context, all feasible switching sequences can be represented as directed paths from the virtual starting point to the virtual ending point in the graph, with nodes... and These serve as virtual start and virtual end nodes, respectively, to assist in shortest path calculation. Connect all available time slots Access satellites that provide services, and Then connect all the connections that can be made in time slots. Satellites providing services within the country;

[0123] Based on the directed weighted graph with minimum hop count, the Dijkstra shortest path algorithm is used to obtain the feasible directed path for consumers when switching satellites;

[0124] Calculate the sum of edge weights for all feasible directed edges of each feasible directed path;

[0125] Choose the feasible directed path with the smallest edge weight as the shortest path switching scheme.

[0126] The beneficial effects achieved by the embodiments of the present invention are as follows:

[0127] This paper obtains the number of orbital planes, the number of satellites in a single orbit, and the topological connections between satellites in a low-Earth orbit (LEO) satellite network based on a named data network. When a consumer accesses the LEO satellite network and communicates with a producer network, the paper obtains the set of consumer access satellites that can provide services to the consumer during the total service time, and the set of producer access satellites that can provide services to the producer during the total service time. Based on the consumer access satellite set and the producer access satellite set, the paper determines the average number of hops between each consumer access satellite and a producer access satellite within its own service time slot. Using minimizing the average number of hops as the optimization objective, a LEO satellite network handover optimization model is constructed. Based on a pre-defined minimum hop count graph handover strategy, the LEO satellite network handover optimization model is solved to obtain the shortest path handover scheme for consumers during satellite handover. The paper constructs an LEO satellite network handover optimization model with minimizing the average number of hops as the optimization objective and provides a pre-defined minimum hop count graph handover strategy. This ensures that when consumers switch between different access satellites, they meet the constraint of minimizing the average number of hops while selecting the shortest path, guaranteeing minimal latency for consumers during network communication.

[0128] Based on the naming data network-based low-Earth orbit satellite network handover optimization method described in the above embodiments, the following embodiments illustrate the naming data network-based low-Earth orbit satellite network handover optimization system.

[0129] like Figure 5 As shown, this embodiment of the invention provides a low-Earth orbit satellite network handover optimization system based on a named data network, comprising:

[0130] The satellite network data acquisition module 501 is used to acquire the number of orbital planes, the number of satellites in a single orbit, and the topological connections between satellites in a low-Earth orbit satellite network based on a named data network.

[0131] The access satellite acquisition module 502 is used to acquire, during the total service time, the set of consumer access satellites that can provide services to consumers and the set of producer access satellites for producers during the total service time when consumers access the low-Earth orbit satellite network to communicate with the producer network.

[0132] The routing hop count determination module 503 is used to determine the average routing hop count between each consumer access satellite and the producer access satellite within its own service time slot, based on the consumer access satellite set and the producer access satellite set.

[0133] Model building module 504 is used to build a low-Earth orbit satellite network handover optimization model with minimizing the average routing hop count as the optimization objective.

[0134] The shortest path switching module 505 is used to solve the low-orbit satellite network switching optimization model based on the preset minimum hop count switching strategy, so as to obtain the shortest path switching scheme for consumers when switching satellites.

[0135] The implementation details of each module in the low-Earth orbit satellite network handover optimization system based on named data networks in this embodiment can be found by referring to... Figure 1 The steps described in the illustrated embodiments can bring the following beneficial effects:

[0136] A low-Earth orbit satellite network handover optimization model is constructed with minimizing the average routing hop count as the optimization objective. A pre-set minimum hop count graph handover strategy is provided, which enables consumers to select the shortest path while satisfying the constraint of minimizing the average routing hop count when switching between different access satellites, thus ensuring that consumers have the minimum latency during network communication.

[0137] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0138] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0139] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0140] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0141] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.

Claims

1. A low-Earth orbit satellite network handover optimization method based on named data networks, characterized in that, include: Obtain the number of orbital planes, the number of satellites in a single orbit, and the topological connections between satellites in a low-Earth orbit satellite network based on a named data network; When a consumer accesses the low-Earth orbit satellite network and communicates with the producer network, the set of consumer access satellites that can provide services to the consumer during the total service time, and the set of producer access satellites for the producer during the total service time are obtained. Based on the consumer access satellite set and the producer access satellite set, determine the average number of routing hops between each consumer access satellite and the producer access satellite within its own service time slot; A low-Earth orbit satellite network handover optimization model is constructed with minimizing the average routing hop count as the optimization objective. Based on the preset minimum hop count graph switching strategy, the low-orbit satellite network switching optimization model is solved to obtain the shortest path switching scheme for the consumer during satellite switching.

2. The low-Earth orbit satellite network handover optimization method based on named data networks according to claim 1, characterized in that, The acquisition of the number of orbital planes, the number of satellites in a single orbit, and the topological connections between satellites in a low-Earth orbit satellite network based on a named data network includes: Obtain the number of orbital planes of a low-Earth orbit satellite network based on a named data network. and the number of satellites in each orbit ; Based on the pre-defined +Grid topology connection relationship, the connection relationship between each satellite and its adjacent satellites in the same orbit, as well as its relationship with its adjacent satellites in adjacent orbits, is determined.

3. The low-Earth orbit satellite network handover optimization method based on named data networks according to claim 2, characterized in that, The acquisition of the set of consumer access satellites that can provide services to the consumer during the total service time, and the set of producer access satellites for the producer during the total service time, includes: Obtain the service time of the consumer The service time is determined according to the principle of constant time interval. Divided into Each service slot The It is a positive integer; The total service time is obtained based on the preset consumer satellite handover strategy and the shortest path routing rule. The set of consumer access satellites that can provide services to the aforementioned consumers; The total service time was obtained based on the known producer satellite switching sequence. The producers mentioned above access the satellite set.

4. The low-Earth orbit satellite network handover optimization method based on named data networks according to claim 3, characterized in that, The step of determining the average number of routing hops between each consumer access satellite and a producer access satellite within its own service time slot, based on the consumer access satellite set and the producer access satellite set, includes: Based on the consumer access satellite set and the producer access satellite set, determine Consumer access to satellite at any time and producers access satellite The Access satellite for the producers During the service break, The consumer access satellite Indicates that it is located at the th The first orbit One satellite, the producer access satellite Indicates that it is located at the th The first orbit One satellite; The calculation yielded the above Consumer access satellite at the time Access satellite with the producer Inter-satellite route hop count The inter-satellite routing hop count The expression is: ； Among them, the This indicates the preset deviation jump coefficient; Based on the inter-satellite route hop count Construct the consumer access satellite Its own service slot Internal connection with the producer access satellite Average number of route hops between The average number of routing hops The expression is: ； Among them, the This indicates that the consumer accesses the satellite. The service start time slot, the This indicates that the consumer accesses the satellite. During the service break, , .

5. The low-Earth orbit satellite network handover optimization method based on named data networks according to claim 4, characterized in that, The optimization model for low-Earth orbit satellite network handover, which uses minimizing the average routing hop count as the optimization objective, includes: To minimize the average route hop count As the optimization objective, the expression for the first constraint condition is constructed as follows: ； With the aforementioned consumer access satellite Preset single-satellite service threshold The expression for the second constraint is constructed as follows: ； Determine the consumer access satellite Subsequent consumer access satellites The number of consecutive satellite route hops was calculated. Based on a preset consecutive access hop count threshold The expression for the third constraint is constructed as follows: ； Based on the above and the aforementioned The expression for the fourth constraint is constructed as follows: ； Based on the expressions of the first constraint, the second constraint, the third constraint, and the fourth constraint, a low-Earth orbit satellite network handover optimization model is constructed.

6. The low-Earth orbit satellite network handover optimization method based on named data networks according to claim 5, characterized in that, The preset minimum hop count graph switching strategy includes: The minimum hop count graph is obtained based on the minimum hop count graph mapping algorithm. The nodes in the minimum hop count graph are the satellites in the consumer access satellite set and the producer access satellite set. The node connectivity between the nodes is determined by whether the service end time slot of one satellite falls within the service time slot of another satellite. Based on the average route hop count Obtain the edge weight of the directed edge between two connected nodes. The edge weight The expression is ; Directed edges whose weights satisfy the first constraint, the second constraint, the third constraint, and the fourth constraint are selected as feasible directed edges. Based on the feasible directed edges and their corresponding weights, the minimum hop count graph is labeled to obtain a minimum hop count directed weighted graph.

7. The low-Earth orbit satellite network handover optimization method based on named data networks according to claim 6, characterized in that, The method based on a preset minimum hop count graph handover strategy solves the low-Earth orbit satellite network handover optimization model to obtain the shortest path handover scheme for the consumer during satellite handover, including: Based on the minimum hop count directed weighted graph, the Dijkstra shortest path algorithm is used to obtain the feasible directed path for the consumer during satellite handover. Calculate the sum of edge weights for all feasible directed edges of each feasible directed path; The feasible directed path with the smallest edge weight is selected as the shortest path switching scheme.

8. A low-Earth orbit satellite network handover optimization system based on a named data network, characterized in that, include: The satellite network data acquisition module is used to acquire the number of orbital planes, the number of satellites in a single orbit, and the topological connections between satellites in a low-Earth orbit satellite network based on a named data network. The access satellite acquisition module is used to acquire, during the total service time, the set of consumer access satellites that can provide services to the consumer and the set of producer access satellites for the producer during the total service time when the consumer accesses the low-Earth orbit satellite network to communicate with the producer network. The routing hop count determination module is used to determine the average routing hop count between each consumer access satellite and the producer access satellite within its own service time slot, based on the consumer access satellite set and the producer access satellite set. The model building module is used to construct a low-Earth orbit satellite network handover optimization model with minimizing the average routing hop count as the optimization objective. The shortest path switching module is used to solve the low-orbit satellite network switching optimization model based on a preset minimum hop count switching strategy to obtain the shortest path switching scheme for the consumer during satellite switching.

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