A satellite network topology management method and system based on feeder link switching

Abstract

This invention provides a satellite network topology management method and system based on feeder link switching. The method includes: constructing a continuously time-varying network topology model, and storing the availability sequence, available bandwidth sequence, and propagation delay of each link; responding to new service requests and obtaining the source satellite node and the target ground station; selecting the target feeder link and its effective connection period based on link status information; screening inter-satellite links that are continuously connected within the time period to form a candidate set, and calculating the average propagation delay and minimum available bandwidth of each link to construct a temporary topology; calculating the transmission path from the source satellite node through inter-satellite links and the target feeder link to the target ground station on the temporary topology; and locally updating the available bandwidth sequence of each link on the path according to the path and bandwidth requirements. This invention achieves efficient management of highly dynamic satellite-ground networks through feeder link event-driven and continuously time-varying modeling, improving service continuity and reducing management overhead.

Description

Technical Field

[0001] This invention relates to the field of integrated space-ground network communication technology, and in particular to a satellite network topology management method and system based on power supply link switching. Background Technology

[0002] As global communication demands evolve towards ubiquitous coverage and ubiquitous access, integrated space-ground networks have become the core architecture of 6G and future communication systems. Among these, large-scale low-Earth orbit (LEO) satellite constellations, through dense inter-satellite and feeder links, form a dynamic space-based backbone network, crucial for achieving seamless global broadband coverage. However, the high-speed movement of satellites leads to continuous and drastic changes in network topology, particularly the frequent connection and disconnection of feeder links connecting satellites and ground gateway stations. This makes the overall topology far more dynamic than traditional terrestrial networks, posing a severe challenge to efficient and stable topology management.

[0003] To address this, the industry primarily employs virtual topology and virtual node methods for management. Virtual topology discretizes time into a static snapshot sequence, performing route planning within each time slice. While this simplifies processing, in large constellation scenarios, the snapshot interval needs to be drastically shortened to accurately depict the frequently changing link states, leading to a sharp increase in storage overhead. Furthermore, service paths are forced to be interrupted and recalculated during snapshot switching, severely impacting transmission continuity. Virtual node methods hide satellite mobility by binding geographical areas to virtual nodes. However, in densely populated areas where satellites pass overhead, the mapping relationship between virtual nodes and actual satellites is complex and frequently changes, resulting in a heavy computational burden. Simultaneously, its excessive abstraction makes it difficult to represent the true physical resources of the feeder links, such as beamwidth and remaining connection time, leading to inaccurate resource scheduling and low link utilization.

[0004] Therefore, there is an urgent need in this field for a new topology management scheme that can adapt to the characteristics of highly dynamic integrated space-ground networks, in order to overcome the inherent defects of existing technologies in terms of storage efficiency, service continuity and resource scheduling accuracy, thereby ensuring the efficient and stable transmission of services across the entire network. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a satellite network topology management method and system based on power supply link switching, in order to solve the problems of high storage redundancy, frequent service path switching, and low network resource utilization efficiency caused by the use of discrete snapshots with fixed time slices when existing satellite network topology management methods deal with frequent power supply link switching in large-scale low-Earth orbit constellations.

[0006] One aspect of the present invention provides a satellite network topology management method based on feeder link switching, comprising the following steps: A continuously time-varying network topology model is constructed and maintained. The continuously time-varying network topology model includes a set of nodes and a set of time-varying links. The set of nodes consists of a subset of satellite nodes and a subset of ground station nodes. The set of time-varying links consists of a subset of inter-satellite links and a subset of feeder links. Each link is associated with and stores link state information recorded in a continuously time-varying function form. The link state information includes at least a link availability sequence, an available bandwidth sequence, and a propagation delay expressed in function form. In response to a routing request for a new service, the source node identifier and target node identifier of the new service are obtained, wherein the source node identifier corresponds to a source satellite node in the node set, and the target node identifier corresponds to a target ground station node in the node set; In the time-varying link set, query the power supply links connected to the target ground station node, and select one as the target power supply link according to the link status information and preset optimization conditions, and obtain its effective connection time period from the link availability sequence associated with the target power supply link; Based on the link availability sequence corresponding to each link, inter-satellite links that remain connected during the effective connection period are selected from the time-varying link set to form a candidate link set; For each link in the candidate link set, its average propagation delay and minimum available bandwidth during the effective connection period are determined based on the link status information stored in association, and a temporary topology is constructed. Based on the temporary topology, calculate the transmission path for the new service, starting from the source satellite node, via one or more inter-satellite links, and finally reaching the target ground station node through the target feed link; Based on the transmission path and the bandwidth requirements of the new service, the available bandwidth sequence of each link on the transmission path during the effective connection period is locally updated.

[0007] In some embodiments of the present invention, querying the time-varying link set for the power supply link connected to the target ground station node, and selecting one as the target power supply link according to the link status information and preset optimization conditions, includes: maximizing the effective connection time period length to select the target power supply link.

[0008] In some embodiments of the present invention, the method further includes: selecting the target power supply link according to one or more of a preset bandwidth matching condition, a delay constraint condition, or a delay jitter constraint condition; The preset bandwidth matching condition requires that the minimum available bandwidth of the target power supply link during the effective connection period be greater than the bandwidth requirement of the new service; The delay constraint requires that the average propagation delay of the target power supply link during the effective connection period be less than or equal to the maximum delay threshold of the new service. The delay jitter constraint requires that the propagation delay fluctuation amplitude of the target power supply link during the effective connection period be less than or equal to a preset threshold.

[0009] In some embodiments of the present invention, the method further includes: selecting the target power supply link based on load balancing conditions and / or the condition of lowest disconnection risk; The load balancing condition requires that the current used bandwidth of the target power supply link is less than a preset ratio; The minimum disconnection risk condition requires that the target power supply link has no preset disconnection events during the effective connection period.

[0010] In some embodiments of the present invention, a partial update is performed on the available bandwidth sequence of each link on the transmission path during the effective connection period, including: For each link involved in the transmission path, at least one time segment that overlaps with the effective connection period is determined based on the available bandwidth sequence associated with it; the available bandwidth value in the time segment is subtracted from the bandwidth requirement value of the new service to update the corresponding available bandwidth sequence.

[0011] In some embodiments of the present invention, the method further includes packet processing of affected services when a power supply link switch occurs, specifically including: Identify the feeder links that are about to be disconnected; determine all services being transmitted on the feeder links, forming a set of affected services; For each service in the service set, a new target power supply link is selected for it based on the link state information in the continuous time-varying network topology model; Services that have selected the same new target feeder link will be grouped into the same service group for joint management.

[0012] In some embodiments of the present invention, joint management of the same business group further includes: The new time window is defined as the time from the original power supply link disconnection time to the expected disconnection time of the new target power supply link corresponding to the service group. Based on the continuous time-varying network topology model and the new time window, a temporary topology shared by all services within the service group is generated. Based on the shared temporary topology, the transmission paths for all services within the service group are recalculated, and the time-varying network topology model is updated.

[0013] On the other hand, the present invention also provides a satellite network topology management system based on feeder link switching, the system comprising: A satellite network comprising multiple satellite nodes connected to each other via inter-satellite links; The ground station network consists of multiple ground station nodes; The satellite nodes in the satellite network and the ground station nodes in the ground station network are connected via a power supply link; the satellite network, the ground station network, and the power supply link together constitute the actual physical network described by the continuous time-varying network topology model; when the satellite node responds to a new service from the user terminal, it executes the satellite network topology management method based on power supply link switching as described above.

[0014] On the other hand, the present invention also provides a computer-readable storage medium having a computer program or instructions stored thereon, which, when executed by a processor, implement the steps of the method as described in any of the preceding claims.

[0015] On the other hand, the present invention also provides a computer program product, including a computer program or instructions that, when executed by a processor, implement the steps of any of the methods described above.

[0016] The present invention provides a satellite network topology management method and system based on feeder link switching, comprising: constructing and maintaining a continuously time-varying network topology model including satellite nodes and ground station nodes, inter-satellite links and feeder links, wherein each link in the model is associated with and stored in the form of a continuously time-varying function for recording link state information, the link state information including at least a link availability sequence, an available bandwidth sequence and a propagation delay expressed in function form; responding to a new service request and obtaining its source satellite node and target ground station node; querying the feeder links connected to the target ground station node in the time-varying link set, and selecting one as the feeder link according to preset optimization conditions based on the link state information. This method identifies the target feeder link and obtains the effective connection period from its link availability sequence. Based on the link availability sequence of each link, inter-satellite links that remain continuously connected during the effective connection period are selected to form a candidate link set. For each link in the candidate link set, its average propagation delay and minimum available bandwidth during the effective connection period are determined based on its link status information, and a temporary topology is constructed. Based on this temporary topology, the transmission path from the source satellite node through the inter-satellite link and the target feeder link to the target ground station node is calculated. According to this path and the bandwidth requirements of the new service, the available bandwidth sequence of each link on the transmission path during the effective connection period is locally updated. This method is driven by feeder link switching events and overcomes the shortcomings of traditional discrete snapshot methods in terms of storage overhead, path switching frequency, and resource scheduling accuracy through continuous time-varying modeling, stable link selection based on link availability sequences, and precise local updates of available bandwidth sequences.

[0017] Furthermore, preset optimization conditions may include maximizing effective connection periods, meeting constraints such as bandwidth, latency, or load balancing, thereby achieving topology selection optimization while ensuring service quality.

[0018] Furthermore, the present invention also provides a mechanism for grouping affected services during power supply link switching and a batch path replanning mechanism based on shared temporary topology, which further significantly improves the efficiency of topology management and service continuity in highly dynamic satellite-ground converged networks.

[0019] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows, and will also become apparent in part to those skilled in the art upon studying the description, or may be learned by practice of the invention. The objects and other advantages of the invention can be realized and obtained by means of the structures specifically pointed out in the description and drawings.

[0020] Those skilled in the art will understand that the objectives and advantages achievable with the present invention are not limited to those specifically described above, and that the above and other objectives achievable with the present invention will become clearer from the following detailed description. Attached Figure Description

[0021] The accompanying drawings, which are provided to further illustrate the invention and form part of this application, are not intended to limit the scope of the invention.

[0022] Figure 1 This is a flowchart illustrating a satellite network topology management method based on power supply link switching, as described in an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of the network architecture of the satellite network fusion satellite network in the satellite network topology management method based on power supply link switching according to another embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram illustrating the dynamic change over time of the feeder link connection relationship between the satellite and the ground station in the satellite network topology management method based on feeder link switching, as described in another embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram illustrating the rerouting and grouping of affected services in a satellite network topology management method based on power supply link switching, as described in another embodiment of the present invention, when a power supply link switching occurs. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings. Here, the illustrative embodiments and descriptions of this invention are used to explain the invention, but are not intended to limit the invention.

[0027] It should also be noted that, in order to avoid obscuring the invention with unnecessary details, only the structures and / or processing steps closely related to the solution according to the invention are shown in the accompanying drawings, while other details that are not closely related to the invention are omitted.

[0028] With the rapid development of large-scale low Earth orbit (LEO) satellite constellations, systems such as Starlink, OneWeb, and Kuiper have deployed thousands of satellites, providing global coverage, high bandwidth, and low latency services. In the space-ground converged network architecture, ground stations are connected to high-speed moving satellites via frequently switching power supply links, resulting in a highly dynamic and complex network topology. This poses significant challenges to topology management and routing planning for satellite networks.

[0029] Existing mainstream topology management methods, such as virtual topology and virtual node methods, show significant shortcomings when dealing with ultra-large-scale constellations. Virtual topology discretizes the time domain into fixed-length time slices, such as snapshots, treating the topology as static and calculating routes independently within each snapshot. While this simplifies processing, it has inherent drawbacks: first, to accurately depict frequently switching feeder links, the snapshot duration must be drastically shortened, leading to a surge in the number of snapshots and resulting in massive redundant storage of topology information, incurring high storage costs; second, frequent snapshot switching triggers repeated replanning of service paths, severely impairing transmission continuity. Virtual node methods hide satellite mobility by binding geographical areas to virtual nodes, but in densely populated constellation areas, a single virtual node needs to be mapped to multiple actual satellites, resulting in complex mapping relationships and high maintenance costs. Furthermore, this method over-abstracts physical resources, failing to accurately reflect the actual resource status of links between different satellites and ground stations, leading to inefficient link bandwidth allocation and scheduling, and insufficient resource utilization.

[0030] Whether it's the storage and switching overhead caused by discrete snapshots or the resource scheduling inaccuracies resulting from virtual node abstraction, the root cause lies in the fact that existing methods fail to efficiently and accurately characterize and respond to network dynamics driven primarily by the on / off status of power supply links. Traditional global, periodic topology update patterns are no longer suitable for scenarios with frequent power supply link switching.

[0031] In view of this, one aspect of the present invention provides a satellite network topology management method based on power supply link switching, such as... Figure 1 As shown, the process includes the following steps S101 to S107: Step S101: Construct and maintain a continuously time-varying network topology model. The continuously time-varying network topology model includes a set of nodes and a set of time-varying links. The set of nodes consists of a subset of satellite nodes and a subset of ground station nodes. The set of time-varying links consists of a subset of inter-satellite links and a subset of feeder links. Each link is associated with and stores link state information recorded in a continuously time-varying function form. The link state information includes at least the link availability sequence, the available bandwidth sequence, and the propagation delay expressed in function form.

[0032] Step S102: In response to the routing request of the new service, obtain the source node identifier and target node identifier of the new service, wherein the source node identifier corresponds to the source satellite node in the node set, and the target node identifier corresponds to a target ground station node in the node set.

[0033] Step S103: Query the feeder links connected to the target ground station node in the time-varying link set, and select one as the target feeder link according to the link status information and preset optimization conditions, and obtain its effective connection time period from the link availability sequence associated with the target feeder link.

[0034] Step S104: Based on the link availability sequence corresponding to each link, select inter-satellite links that are continuously connected during the effective connection period from the time-varying link set to form a candidate link set.

[0035] Step S105: For each link in the candidate link set, determine its average propagation delay and minimum available bandwidth during the effective connection period based on the link state information stored with it, and construct a temporary topology.

[0036] Step S106: Based on the temporary topology, calculate the transmission path for the new service, starting from the source satellite node, passing through one or more inter-satellite links, and finally reaching the target ground station node through the target feeder link.

[0037] Step S107: Based on the transmission path and the bandwidth requirements of the new service, locally update the available bandwidth sequence of each link on the transmission path during the effective connection period.

[0038] In step S101, a continuous time-varying network topology model is constructed and maintained to accurately characterize the dynamic satellite network, which includes satellite nodes, ground station nodes, inter-satellite links, and feeder links. The core of this model is that it abandons the traditional method of discretizing the time domain into fixed-interval snapshots and instead adopts a continuous mathematical representation to describe the time-varying characteristics of network topology and resource status.

[0039] Specifically, the model defines two basic sets: a node set and a time-varying link set. The node set consists of a subset of satellite nodes and a subset of ground station nodes; the time-varying link set consists of a subset of inter-satellite links and a subset of power supply links.

[0040] For each link in the time-varying link set, the model does not store multiple discrete copies of its state at different points in time. Instead, it stores the link state information as a continuous time-varying function. The link state information includes at least the link availability sequence, the available bandwidth sequence, and the propagation delay expressed as a function, which are used to accurately describe the link's on / off state, the remaining bandwidth available for allocation, and the changes in signal transmission delay over time.

[0041] In some embodiments, a continuously time-varying network topology model is defined as a graph model comprising a set of satellite nodes, a set of ground station nodes, a set of inter-satellite links, and a set of feeder links, wherein the continuously time-varying graph is defined as follows: ; in, Represents a set of nodes; Represents a set of time-varying links; Represent the network topology at time t; The node set is the union of the satellite node set and the ground station node set, defined as: ; in, Represents a set of satellite nodes; Represents the set of ground station nodes; The set of satellite nodes is defined as: ; Where n is the total number of satellite nodes; This represents the nth satellite node; Represents a set of satellite nodes; The set of ground station nodes is defined as follows: ; in, This represents the set of ground station nodes; m represents the total number of ground station nodes. This represents the m-th ground station node; The time-varying link set is the union of the inter-satellite link set and the feeder link set, defined as: ; in, Represents the set of inter-satellite links; Represents the set of power supply links; Represents a set of time-varying links; In some embodiments, the link state information includes a link availability sequence, an available bandwidth sequence, and a delay function, wherein, for any link : Link availability sequence, calculated as follows: ; in, Represents a sequence of link availability; each triplet This indicates that link e is in the time interval The connectivity state within; Discrete state values ​​indicating whether a link is connected or disconnected; The available bandwidth sequence is calculated as follows: ; in, Represents the available bandwidth sequence; each triplet This indicates that link e is in the time interval Available bandwidth value within; The time delay function is defined as: ; in, Represents the time delay function; represents the physical length of link e at time t; c represents the speed of light. This distance-based real-time calculation method can accurately reflect the changes in propagation delay caused by the high-speed motion of the satellite.

[0042] In step S102, in response to receiving a routing request for a new service, the parsing and parameter extraction operations of the request are performed.

[0043] Specifically, two key network entity identifiers are obtained from the routing request: the source node identifier and the target node identifier.

[0044] In some embodiments, the source node identifies a satellite node in the corresponding node set, which is typically the initial access point or forwarding point for service data in the space network. Correspondingly, the target node identifies a ground station node in the corresponding node set, i.e., the ground gateway station to which the service data ultimately needs to be delivered and enter the ground network.

[0045] In step S103, the target feeder link is determined. This operation includes querying the feeder links connected to the target ground station node in the time-varying link set, selecting one as the target feeder link according to the link status information and preset optimization conditions, and obtaining its effective connection time period from the associated stored link availability sequence.

[0046] In some embodiments, the selection of power supply links is based on a link availability sequence in the link status information. This sequence clearly indicates the on / off schedule of each power supply link over a future period, providing a precise basis for optimal selection.

[0047] In some embodiments, the selection strategy focuses on the transmission stability of the service. For example, the optimization condition may be to maximize the effective connection time length of the target feeder link. Based on the link availability sequence, the remaining planned connection time of each candidate feeder link from the current moment can be calculated, and the feeder link with the longest remaining connection time can be selected as the target feeder link to extend the stable service time window covered by a single routing decision.

[0048] In other embodiments, the preset optimization conditions also include one or more combinations of the following: bandwidth matching condition, which requires that the minimum available bandwidth of the selected target feeder link during the effective connection period is greater than the bandwidth requirement of the new service; latency constraint condition, which requires that its average propagation latency is less than or equal to the maximum latency threshold of the new service; latency jitter constraint condition, which requires that its propagation latency fluctuation amplitude is less than or equal to a preset threshold; load balancing condition, which requires that its currently used bandwidth ratio is less than a preset proportion; or minimum disconnection risk condition, which requires that there are no preset disconnection events during the effective connection period. These conditions can be used independently or in combination to select the feeder link that best meets the service quality requirements and network optimization objectives.

[0049] In some embodiments, obtaining the effective connection period is a process of directly reading stored model information. By parsing the link availability sequence of the target feeder link, the start time when the link becomes available and the end time when it is scheduled to be disconnected can be directly obtained, thereby determining the complete effective connection period.

[0050] In step S104, a topology pruning operation is performed. This operation uses the valid connection period determined in step S103 as the standard and filters out network connections available during this period from the global dynamic topology.

[0051] Specifically, based on the link availability sequence corresponding to each link, inter-satellite links that remain connected during the effective connection period are selected from the time-varying link set to form a candidate link set.

[0052] In some embodiments, the determination operation relies on a link availability sequence. By parsing this sequence, it is checked whether there are one or more consecutive time intervals that completely cover the effective connection period, and whether the link status recorded in these intervals is always connected, thereby determining whether the link remains connected during this period.

[0053] In step S105, a temporary topology construction operation is performed. The purpose of this operation is to convert the candidate link set obtained in step S104 into a static network topology diagram with defined resource parameters.

[0054] Specifically, for each link in the candidate link set, based on its associated stored link state information, its average propagation delay and minimum available bandwidth during the effective connection period are determined, and a temporary topology is constructed accordingly.

[0055] In some embodiments, the average propagation delay is calculated using the propagation delay expressed as a function, achieved by integrating and averaging. The minimum available bandwidth is determined by querying and comparing the available bandwidth sequences of the links, and taking the minimum bandwidth value among all segments overlapping with the effective connection period.

[0056] In some embodiments, the temporary topology is stored in the form of a graph data structure. Nodes correspond to satellites and ground stations, edges correspond to links in the candidate link set, and each edge has two weighted attributes: average propagation delay and minimum available bandwidth. This graph structure is considered fixed during the effective connection period, thus allowing the application of classic shortest path or constrained routing algorithms.

[0057] In step S106, the service transmission path is calculated. Based on the temporary topology generated in step S105, the transmission path for the new service is calculated, starting from the source satellite node, passing through one or more inter-satellite links, and finally reaching the target ground station node through the target feeder link.

[0058] In some embodiments, the classic shortest path algorithm is used to calculate the path. For example, Dijkstra's algorithm, which uses the average propagation delay of the links as a metric, is applied to calculate the path with the minimum delay in the temporary topology, and to ensure that the minimum available bandwidth of each link on the path is not less than the bandwidth requirement of the new service.

[0059] In step S107, the recording and synchronization of business resource usage are performed, and the continuous time-varying network topology model is incrementally updated.

[0060] Specifically, based on the transmission path determined in step S106 and the bandwidth requirements of the new service, the available bandwidth sequence of each link on the transmission path during the effective connection period is locally updated.

[0061] In some embodiments, the partial update operation includes: for each link involved in the transmission path, determining a time segment that overlaps with the effective connection period based on its available bandwidth sequence, and subtracting the bandwidth requirement value of the new service from the available bandwidth value in that segment.

[0062] In some embodiments, if the occupancy of a service causes an original continuous bandwidth time period to need to be divided into multiple segments with different available bandwidth values, the available bandwidth sequence of the link will be inserted and segmented accordingly to maintain the accuracy of the sequence description.

[0063] In some embodiments, the satellite network topology management method provided by the present invention further includes a process for replanning and grouping existing services affected by a power supply link switchover. This process is used to address planned disconnections of power supply links caused by satellite motion and to maintain service continuity and optimize network resource management efficiency during the switchover process.

[0064] In some embodiments, the above process is triggered by detecting that a power supply link is about to enter a planned disconnection state. First, the power supply link that is about to be disconnected is identified, and then all services currently using that link for data transmission are queried to determine the affected service set.

[0065] In some embodiments, a new target feeder link is reselected for each service in the affected service set. This selection process is based on link state information in a continuously time-varying network topology model, and its strategy can be the same as or similar to that used when selecting an initial feeder link for a new service. For example, for each service, the new target feeder link can be selected from the currently available feeder links that are connected to its original target ground station, choosing the one with the longest planned remaining connection time.

[0066] In some embodiments, after the selection of a new feeder link is completed, a service grouping operation is performed. Services that have selected the same new feeder link are grouped into the same service group. In this way, all services that need to be rerouted due to the same link switching event are classified according to the downlink egress they will use.

[0067] In some embodiments, for each service group, collaborative path replanning is performed based on the new target feeder link shared by the services in that group. First, a unified planning time window is determined: the start time of this window is the time when the original feeder link is scheduled to be disconnected, and the end time is the time when the new target feeder link is expected to be disconnected.

[0068] In some embodiments, a temporary topology is generated based on the continuous time-varying network topology model and this unified time window. The generation of this temporary topology is consistent with the principles of steps S104 and S105: a candidate set is formed by selecting links that remain continuously connected within the time window, and the average propagation delay and minimum available bandwidth of each link are calculated to construct a static, weighted network subgraph. This temporary topology will be shared by all services within the service group for batch path calculation.

[0069] In some embodiments, based on a shared temporary topology, the transmission paths from their respective source satellite nodes to the new target feeder links are recalculated for all services within the service group. Subsequently, the available bandwidth status information of the relevant links in the continuously time-varying network topology model is locally updated according to these new paths and the bandwidth requirements of each service.

[0070] The partial update operation specifically includes: for each link occupied by a new transmission path, locating all time segments that overlap with the service-occupied time interval in its associated stored available bandwidth sequence; for each located time segment, subtracting the sum of the bandwidth requirements of all services occupying that link from the available bandwidth value recorded in that segment. If the available bandwidth value of a certain time segment becomes zero or insufficient to meet the needs of other subsequent services after the update, the resource status corresponding to that segment is marked in the model.

[0071] On the other hand, the present invention also provides a satellite network topology management system based on feeder link switching, the system comprising: A satellite network comprising multiple satellite nodes connected to each other via inter-satellite links; The ground station network consists of multiple ground station nodes; The satellite nodes in the satellite network and the ground station nodes in the ground station network are connected via a power supply link; the satellite network, the ground station network, and the power supply link together constitute the actual physical network described by the continuous time-varying network topology model; when the satellite node responds to a new service from the user terminal, it executes the satellite network topology management method based on power supply link switching as described above.

[0072] On the other hand, the present invention also provides a computer-readable storage medium having a computer program or instructions stored thereon, which, when executed by a processor, implement the steps of the method as described in any of the preceding claims.

[0073] On the other hand, the present invention also provides a computer program product, including a computer program or instructions that, when executed by a processor, implement the steps of any of the methods described above.

[0074] The present invention will now be described with reference to a specific embodiment: This embodiment details the design and implementation of a satellite network topology management method based on power supply link switching. This method addresses the problems of high storage redundancy, frequent service path switching, and low resource utilization efficiency in existing satellite network topology management methods when dealing with frequent power supply link switching in large-scale low-Earth orbit constellations. By introducing a continuously time-varying network topology model and using power supply link on / off events as the driving force for local updates and service grouping, it achieves efficient, stable, and low-overhead satellite-to-ground network topology management.

[0075] The specific implementation of this embodiment is as follows: The network architecture of the space-ground integrated satellite network is as follows: Figure 2 As shown, in the space access network, terrestrial services access the space bearer network via uplink through user links. Within the space bearer network, these services are transmitted from the access satellite to the landing satellite via forwarding from satellite nodes, and then downlink to the ground gateway station via the feeder link. In the space-ground converged network scenario considered in this invention, the access satellite of the service is used as the starting point of the routing, and the landing gateway station is used as the endpoint of the service routing management, thereby managing the topology of the satellite bearer network, feeder links, and ground station nodes.

[0076] This invention designs a continuous topology information storage method, overcoming the drawbacks of high storage costs and poor service continuity caused by the discreteness of traditional satellite network topology storage methods. Traditional methods typically divide the satellite network topology into several discrete time segments or "snapshots," treating the network topology within each snapshot as static and storing information such as the connectivity status, latency, and bandwidth of all network links within each time segment. This method requires frequent snapshot switching, resulting in significant topology redundancy and frequent service path switching. In contrast, the continuous topology storage scheme of this invention models the inter-satellite links and feeder links in the satellite network as a network topology graph with continuously time-varying characteristics. It records the connectivity changes of each link and the changes in bandwidth and latency resources over a future period using a continuous function. This continuous function storage method is no longer limited by the time granularity of traditional snapshot methods, accurately representing the network topology state at any given time and significantly reducing storage redundancy.

[0077] The topology management method proposed in this invention models the satellite-to-ground network as a continuous time-varying graph, defined as follows: . Let be a set of nodes, where For a set of satellite nodes, For ground station assembly. Let be the set of edges that change over time, where A set of inter-satellite links, This is a set of power supply links.

[0078] For any edge Each element stores the following information, represented as an array to show the link connectivity and resource changes within a specific time period: Link availability sequence: Defined as a sequence of triples, where each triple represents the link availability within a specific time period. The calculation formula is: ; in, Represents a sequence of link availability; each triplet This indicates that link e is in the time interval The connectivity state within; Discrete state values ​​indicating whether a link is connected or disconnected.

[0079] Available bandwidth sequence: Defined as a sequence of triples, where each triple represents the available bandwidth of the link within a specific time period. The calculation formula is: ; in, Represents the available bandwidth sequence; each triplet This indicates that link e is in the time interval The available bandwidth value within.

[0080] Delay function: defined as ,in Let t be the length of the link at time t, and c be the speed of light. The time delay of the link can be dynamically calculated based on the distance between satellites.

[0081] As shown in Table 1, for this link, the link state may undergo the following changes within the next 600 seconds: maintaining connection and marked as "ON" for 0-150 seconds, being disconnected and marked as "OFF" for 150-400 seconds, and reconnecting and marked as "ON" again for 400-600 seconds. Used bandwidth can be represented similarly. Since the used bandwidth changed at 500 seconds, the used bandwidth for 400-600 seconds is recorded in segments: 600Mbps for 400-500 seconds and 800Mbps for 500-600 seconds. For latency storage, the propagation delay of the link in space can be represented by the quotient of distance and the speed of light, and this formula can be used to calculate the link latency at any given time. The advantage of this continuous topology storage method is that it no longer requires snapshots at fixed intervals, but can represent the network topology state arbitrarily accurately, especially in scenarios where the power supply link state changes frequently and there are many on / off switching events.

[0082] Table 1. Schematic diagram of link resource storage Furthermore, the reasons for changes in service paths mainly fall into two categories: changes in inter-satellite link connectivity and changes in feeder link connectivity. Specifically, since services must be transmitted to the terrestrial network via the feeder link, during this process, such as... Figure 3 As shown, service path switching due to changes in feeder link connections is unavoidable. However, in paths utilizing inter-satellite links, the timing and frequency of path switching can be altered through the appropriate selection of links along the path. In other words, some service path switching caused by changes in feeder link connectivity can be avoided. Therefore, in this invention, we control the impact of changes in inter-satellite link connectivity on service paths, ensuring that all path switching during service transmission occurs at the moment of feeder link change. During each path switching, necessary feeder link switching is achieved, and the inter-satellite transmission path is simultaneously modified, allowing inter-satellite links that will require switching in the coming period to be switched earlier. This achieves coordinated optimization of inter-satellite link switching and feeder link switching, reducing service switching frequency and improving service continuity.

[0083] This invention addresses the network topology update problem when satellite network service information changes, primarily considering two typical service information change scenarios: one is topology updates caused by the arrival of new service requests, and the other is topology updates caused by power supply link switching. Unlike traditional global snapshot switching methods, this invention employs a strategy of local updates and temporary snapshot generation, reducing the overhead of updating network-wide resources and significantly decreasing the frequency of service path switching, thus ensuring service continuity.

[0084] When a new service request arrives at the satellite network, the update process of this invention is as follows: First, the feeder link used by the service to transmit data back to the ground is determined. Once the feeder link is determined, a corresponding temporary topology snapshot is generated according to the start and end connection times of the selected feeder link for subsequent service routing planning. The method for generating this temporary snapshot is as follows: During the entire time period of the feeder link connection, all links that remain connected throughout the time period are selected as the effective link set of the temporary snapshot; for each link in the temporary snapshot, the link delay is taken as the average delay value of the link during the time period, and the available bandwidth of the link is taken as the minimum available bandwidth value of the link during the time period, thereby ensuring that the planned path is always available during the effective time period of the temporary snapshot. Subsequently, the service path is planned based on the generated temporary topology snapshot. Once the service path planning is determined, this invention only performs a partial update on the link resources actually occupied by the new service, without needing to recalculate and store all resource information across the entire network. As shown in Table 2, a new service is added to this link, the service duration is 450~600 seconds, and the bandwidth required by the service is 100Mbps. Therefore, the used bandwidth value on this link needs to be modified during the 450-600 second time period. The updated bandwidth information for Link B is as follows: the used bandwidth remains unchanged at 600 Mbps during the 400-450 second period; the used bandwidth is adjusted to 700 Mbps during the 450-500 second period; and the used bandwidth is adjusted to 900 Mbps during the 500-600 second period. This local resource update method significantly reduces the computational and storage overhead during topology updates.

[0085] Table 2. Schematic diagram of link resource updates During the service lifecycle, with the periodic switching of the power supply link, such as Figure 4 As shown, services require multiple path adjustments. According to the assumptions of this invention, the target gateway station remains unchanged after each feeder link switch, and the new feeder link needs to be selected from the links currently connected to the target gateway station. Since the number of antennas at a gateway station is limited, the number of services requiring path replanning during each feeder link switch is far greater than the number of feeder links. Therefore, this invention proposes an update strategy of service grouping and temporary snapshot sharing.

[0086] When a power supply link switchover occurs, a suitable new power supply link is first selected for all affected services, and services are grouped according to their new power supply link affiliation. Services belonging to the same power supply link are planned using a unified temporary snapshot. This temporary snapshot starts at the moment the original power supply link disconnects and ends at the moment the new power supply link is expected to disconnect. The method for generating this temporary snapshot is consistent with that for new service requests: selecting a set of links that remain connected throughout the time period and determining the average latency of each link as the link resource information for the snapshot. Subsequently, path replanning is performed uniformly for all services within this shared temporary snapshot, and only the link resource information actually affected by the path replanning is partially updated. The update principle is the same as for new service requests: the available bandwidth of each actually used link is updated by reducing the bandwidth occupied by the service, without needing to update the link resources across the entire network.

[0087] In summary, the satellite network topology management method and system based on feeder link switching provided by this invention includes: constructing and maintaining a continuously time-varying network topology model containing satellite nodes and ground station nodes, inter-satellite links and feeder links, wherein each link in the model is associated with and stored in the form of a continuously time-varying function recording link state information, the link state information including at least a link availability sequence, an available bandwidth sequence and a propagation delay expressed in function form; responding to a new service request and obtaining its source satellite node and target ground station node; querying the feeder links connected to the target ground station node in the time-varying link set, and selecting one according to the link state information and preset optimization conditions. The method uses a target feeder link as the target and obtains the effective connection period from its link availability sequence. Based on the link availability sequence of each link, inter-satellite links that remain connected during the effective connection period are selected to form a candidate link set. For each link in the candidate link set, its average propagation delay and minimum available bandwidth during the effective connection period are determined based on its link status information, and a temporary topology is constructed. Based on this temporary topology, the transmission path from the source satellite node through the inter-satellite link and the target feeder link to the target ground station node is calculated. Based on this path and the bandwidth requirements of the new service, the available bandwidth sequence of each link on the transmission path during the effective connection period is locally updated. This method is driven by feeder link switching events and overcomes the shortcomings of traditional discrete snapshot methods in terms of storage overhead, path switching frequency, and resource scheduling accuracy through continuous time-varying modeling, stable link selection based on link availability sequence, and accurate local updates of available bandwidth sequence.

[0088] Furthermore, preset optimization conditions may include maximizing effective connection periods, meeting constraints such as bandwidth, latency, or load balancing, thereby achieving topology selection optimization while ensuring service quality.

[0089] Those skilled in the art will understand that the exemplary components, systems, and methods described in conjunction with the embodiments disclosed herein can be implemented in hardware, software, or a combination of both. Whether implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this invention. When implemented in hardware, it can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this invention are programs or code segments used to perform the desired tasks. The programs or code segments can be stored in a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried in a carrier wave.

[0090] It should be clarified that the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of the present invention.

[0091] In this invention, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with or in place of features of other embodiments.

[0092] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, various modifications and variations of the embodiments of the present invention are possible. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A satellite network topology management method based on feeder link switching, characterized in that, The method includes the following steps: A continuously time-varying network topology model is constructed and maintained. The continuously time-varying network topology model includes a set of nodes and a set of time-varying links. The set of nodes consists of a subset of satellite nodes and a subset of ground station nodes. The set of time-varying links consists of a subset of inter-satellite links and a subset of feeder links. Each link is associated with and stores link state information recorded in a continuously time-varying function form. The link state information includes at least a link availability sequence, an available bandwidth sequence, and a propagation delay expressed in function form. In response to a routing request for a new service, the source node identifier and target node identifier of the new service are obtained, wherein the source node identifier corresponds to a source satellite node in the node set, and the target node identifier corresponds to a target ground station node in the node set; In the time-varying link set, query the power supply links connected to the target ground station node, and select one as the target power supply link according to the link status information and preset optimization conditions, and obtain its effective connection time period from the link availability sequence associated with the target power supply link; Based on the link availability sequence corresponding to each link, inter-satellite links that remain connected during the effective connection period are selected from the time-varying link set to form a candidate link set; For each link in the candidate link set, its average propagation delay and minimum available bandwidth during the effective connection period are determined based on the link status information stored in association, and a temporary topology is constructed. Based on the temporary topology, calculate the transmission path for the new service, starting from the source satellite node, via one or more inter-satellite links, and finally reaching the target ground station node through the target feed link; Based on the transmission path and the bandwidth requirements of the new service, the available bandwidth sequence of each link on the transmission path during the effective connection period is locally updated.

2. The satellite network topology management method based on power supply link switching according to claim 1, characterized in that, The process involves querying the power supply links connected to the target ground station node in the time-varying link set, and selecting one as the target power supply link based on the link status information and preset optimization conditions, including: maximizing the effective connection time period length when selecting the target power supply link.

3. The satellite network topology management method based on power supply link switching according to claim 2, characterized in that, The method further includes: selecting the target power supply link according to one or more of preset bandwidth matching conditions, delay constraints, or delay jitter constraints; The preset bandwidth matching condition requires that the minimum available bandwidth of the target power supply link during the effective connection period be greater than the bandwidth requirement of the new service; The delay constraint requires that the average propagation delay of the target power supply link during the effective connection period be less than or equal to the maximum delay threshold of the new service. The delay jitter constraint requires that the propagation delay fluctuation amplitude of the target power supply link during the effective connection period be less than or equal to a preset threshold.

4. The satellite network topology management method based on power supply link switching according to claim 2, characterized in that, The method further includes: selecting the target power supply link based on load balancing conditions and / or the condition of lowest disconnection risk; The load balancing condition requires that the current used bandwidth of the target power supply link is less than a preset ratio; The minimum disconnection risk condition requires that the target power supply link has no preset disconnection events during the effective connection period.

5. The satellite network topology management method based on feeder link switching according to claim 1, characterized in that, The available bandwidth sequence of each link on the transmission path during the effective connection period is locally updated, including: For each link involved in the transmission path, at least one time segment that overlaps with the effective connection period is determined based on the available bandwidth sequence associated with it; the available bandwidth value in the time segment is subtracted from the bandwidth requirement value of the new service to update the corresponding available bandwidth sequence.

6. The satellite network topology management method based on power supply link switching according to claim 1, characterized in that, The method further includes packet processing of affected services when a power supply link switch occurs, specifically including the following steps: Identify the feeder links that are about to be disconnected; determine all services being transmitted on the feeder links, forming a set of affected services; For each service in the service set, a new target power supply link is selected for it based on the link state information in the continuous time-varying network topology model; Services that have selected the same new target feeder link will be grouped into the same service group for joint management.

7. The satellite network topology management method based on power supply link switching according to claim 6, characterized in that, Joint management of the same business group also includes: The new time window is defined as the time from the original power supply link disconnection time to the expected disconnection time of the new target power supply link corresponding to the service group. Based on the continuous time-varying network topology model and the new time window, a temporary topology shared by all services within the service group is generated. Based on the shared temporary topology, the transmission paths for all services within the service group are recalculated, and the time-varying network topology model is updated.

8. A satellite network topology management system based on power supply link switching, characterized in that, The system includes: A satellite network comprising multiple satellite nodes connected to each other via inter-satellite links; The ground station network consists of multiple ground station nodes; The satellite nodes in the satellite network and the ground station nodes in the ground station network are connected via a power supply link; the satellite network, the ground station network, and the power supply link together constitute the actual physical network described by the continuous time-varying network topology model; when the satellite node responds to a new service from the user terminal, it executes the satellite network topology management method based on power supply link switching as described in any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed by a processor, they implement the steps of the method as described in any one of claims 1 to 7.

10. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program or instructions are executed by a processor, they implement the steps of the method according to any one of claims 1 to 7.

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