A method and device for access network and core network whole station switching of a multi-satellite multi-station system

Abstract

The application discloses a kind of access network and core network whole station switching method and equipment for multi-satellite multi-station system.The method is: first, real-time monitoring feeder link and the state of guard and non-guard gateway station;Then according to key performance indicators and target available resources, comprehensive consideration of multiple factors, weighted algorithm is used to give access network switching decision, design is suitable for different satellites, different network system, different task Automatic parameter configuration execution script;Finally, core network is deployed distributed hash table (DHT) control agent and bloom filter to jointly guarantee the continuity of core network and data validity in switching process.The equipment includes monitoring module, decision module, execution module and safeguard module, wherein the safeguard module includes route keep-alive unit and data deduplication unit.The application can quickly recover communication when multi-satellite heterogeneous network system feeder link or ground gateway station fails, optimize routing performance and reduce data redundancy, improve system reliability.

Description

Technical Field

[0001] This invention relates to the field of high-orbit satellite communication technology, and in particular to a method and equipment for switching between the access network and the core network of a multi-satellite, multi-station system. Background Technology

[0002] With the rapid development of high-orbit satellite communication systems, multi-satellite heterogeneous networking has become an important means to improve coverage and system capacity. However, due to the complex space environment, high-speed satellite movement, and wide distribution of ground facilities, power supply link interruptions or ground gateway station failures frequently occur. Therefore, it is necessary to quickly switch redundant links, activate preset backup power supply links or ground gateway stations, and seamlessly migrate service traffic to backup paths to ensure that core services are not interrupted.

[0003] Existing handover technologies typically employ a "disconnect first, reconnect later" approach or a simple static route update mechanism. When a failover occurs, traditional methods face the following core problems:

[0004] (1) Slow route convergence: The core network needs to rebroadcast the routing information, resulting in long service interruption time (usually in the hundreds of milliseconds) and failing to meet the real-time communication requirements.

[0005] (2) Data redundancy and storms: Routing oscillations are easily generated during the switching moment, resulting in a large number of duplicate data packets being transmitted in the network, occupying valuable satellite bandwidth resources.

[0006] (3) Single decision: Existing handover decisions rely on a single signal strength indicator, which can easily lead to "ping-pong handover", that is, the terminal frequently switches between two base stations, reducing system stability.

[0007] Therefore, there is an urgent need for an efficient switching solution that can simultaneously ensure the continuity of core network routing and the effectiveness of data transmission. Summary of the Invention

[0008] The purpose of this invention is to provide a method and system for whole-site handover between the access network and the core network in a multi-satellite, multi-site system. This method can quickly achieve whole-site handover when the power supply link or ground gateway fails, ensuring communication continuity. Furthermore, it optimizes data transmission, reduces redundancy and errors, and solves the technical problems of slow route convergence, high data redundancy rate, and single handover decision in the prior art through DHT route keep-alive and Bloom filter data deduplication algorithms.

[0009] The technical solution for achieving the objective of this invention is: a method for switching between the access network and the core network of a multi-satellite, multi-site system, comprising:

[0010] Status synchronization and real-time monitoring steps: synchronize the static configuration and status information between the guarded gateway station and the unguarded gateway station; monitor the status of the power supply link and the gateway station in real time and obtain key performance indicators; when the key performance indicators are found to meet the preset switching conditions, execute the access network switching decision steps.

[0011] Access network handover decision steps: Based on the key performance indicators and target available resources, multiple influencing factors are comprehensively considered, a weighted algorithm is used to calculate the score of each candidate path, and the path with the highest score is selected as the handover target. The target gateway station corresponding to the candidate path with the highest score is determined as the handover target, and the source node and target node of the current communication are marked.

[0012] Handover execution and parameter adjustment steps: Based on the access network handover decision, automatically execute the handover operation of the primary and backup gateway station parameter configurations, and dynamically adjust the communication-related parameters;

[0013] Core network continuity and data validity assurance steps: During the handover process, the source node sends routing update messages to the target node based on a distributed hash table algorithm to ensure the routing continuity of the core network, and filters duplicate data packets based on a Bloom filter algorithm to ensure the validity of data transmission.

[0014] Furthermore, in the state synchronization and real-time monitoring steps, state synchronization between gateway stations is achieved through a dedicated communication link or a shared storage mechanism; the real-time monitoring includes signal strength, bit error rate, gateway station processing capacity, and connection status with the core network.

[0015] Furthermore, in the access network handover decision-making step, the influencing factors include:

[0016] The load status, communication quality, distance from user terminals, and relevant parameters of satellite links of each gateway station; the weights of each factor in the weighted algorithm are preset or dynamically adjusted according to the system application scenario.

[0017] Furthermore, in the access network handover decision-making step, a multi-dimensional weighted evaluation model is used to calculate the score of each candidate path. The calculation formula of the multi-dimensional weighted evaluation model is as follows:

[0018]

[0019] in, A comprehensive score for candidate paths; The signal quality factor is calculated based on a nonlinear mapping of the received signal strength indication and the signal-to-noise ratio. The system load factor represents the resource carrying capacity of the target gateway station, calculated according to... The calculation is equal to 1 minus the current load rate; To switch the cost factor, representing the cost of route reconstruction, it is determined in real time by querying the topological distance between the source node and the target node through a distributed hash table network; , , They are respectively , , The corresponding weights satisfy .

[0020] Furthermore, in the switching execution and parameter adjustment steps, a parameter configuration sequence script uniformly labeled with "satellite identifier - network identifier - mission category" is used, supporting parallel processing of subsystem scripts to execute the switching; the communication-related parameters include communication frequency, power, and network interface settings;

[0021] The data structure of the parameter configuration sequence script includes:

[0022] (1) Basic task information: including task number and task type; the task number is a globally unique task identifier; the task type defines the nature of the task, including power supply link switching, measurement and control command injection, core network element reconfiguration, and service traffic scheduling.

[0023] (2) Target resource information: including satellite identifier and network identifier; the satellite identifier is used to uniquely identify a satellite; the network identifier is used to identify the constellation or network to which the satellite belongs;

[0024] (3) Key configuration instructions: including power supply link configuration, telemetry and control link configuration, access network configuration and core network configuration; power supply link configuration includes carrier frequency, modulation and coding scheme, time slot / frame structure; telemetry and control link configuration includes telemetry and control mode, telemetry parameters; access network configuration includes beam ID, user group policy; core network configuration includes network element function, PDU session anchor point, update routing rules, quality of service 5QI parameters.

[0025] Furthermore, in the core network continuity and data validity assurance steps, the routing continuity of the core network is guaranteed based on a distributed hash table algorithm, specifically as follows:

[0026] The source node marks the cached unsent data and sends a route update message to the target node through a distributed hash table network. The distributed hash table algorithm includes the Kademlia protocol, Chord protocol, or Pastry protocol. The target node reconstructs the route based on the route update message, its own neighbor information, and historical routing records.

[0027] Furthermore, in the core network continuity and data validity assurance steps, the validity of data is guaranteed based on the Bloom filter algorithm, specifically as follows:

[0028] The sending end calculates the hash value of the data block and marks the hash value through a Bloom filter; when the receiving end receives the data block, it calculates its hash value and queries the Bloom filter. If it determines that the hash value already exists, it discards the data block; otherwise, it receives and processes it.

[0029] Furthermore, in the core network continuity and data validity assurance steps, route keep-alive employs hierarchical routing table management:

[0030] The routing table maintained by the node is divided into upper-layer summary routing information and lower-layer detailed routing information;

[0031] When updating routes, the direction is quickly determined first by using summary routing information, and then the route is precisely adjusted based on detailed routing information.

[0032] A device for switching between access network and core network in a multi-satellite, multi-site system, used to execute the aforementioned switching method between access network and core network, the device comprising:

[0033] The monitoring module is used for status synchronization and real-time monitoring;

[0034] The decision module is used to make access network switching decisions;

[0035] The execution module is used for switching execution and adjusting parameters;

[0036] The aforementioned protection module is used to ensure the continuity of the core network and the validity of data.

[0037] Furthermore, the protection module includes:

[0038] The routing keep-alive unit is configured to maintain core network routes using a distributed hash table algorithm.

[0039] The data deduplication unit is configured to use the Bloom filter algorithm to filter duplicate data.

[0040] Compared with the prior art, the significant advantages of this invention are:

[0041] (1) Ultra-low latency handover: By using the DHT algorithm to replace the traditional flooding protocol, the routing convergence time is reduced from hundreds of milliseconds (500ms) in the traditional method to less than 20ms through the pre-synchronization mechanism of the DHT network, and the service interruption time is reduced from hundreds of milliseconds to 20ms (service is not aware of it), which greatly ensures the continuity of core network services and proves that the algorithm has a substantial improvement on the physical communication quality.

[0042] (2) Anti-data storm: Hardware-level data deduplication is performed using the Bloom filter algorithm, which reduces the proportion of redundant data packets during the switching window from 40% to less than 0.1% (with only a very low Bloom filter false positive rate), significantly optimizing the bandwidth utilization of the satellite link;

[0043] (3) Intelligent decision-making: A multi-dimensional weighted evaluation model is introduced to comprehensively consider signal quality factors, system load factors and switching cost factors, which effectively avoids "ping-pong switching" caused by a single signal strength index and improves the resource utilization and stability of the system;

[0044] (4) Fully automated: Through the parameter configuration sequence script uniformly labeled with "satellite identifier - network identifier - mission category", it realizes the automated parameter distribution and parallel processing across star systems and networks. It is suitable for complex multi-star and multi-network environments and supports the execution and switching of parallel processing subsystem script mode. Attached Figure Description

[0045] Figure 1 This is a schematic diagram illustrating the structure of a multi-satellite heterogeneous network in the access network and core network whole-site switching system of the present invention for a multi-satellite multi-site system.

[0046] Figure 2 This is a flowchart illustrating the method for switching between the access network and the core network of a multi-satellite, multi-site system according to the present invention.

[0047] Figure 3 This is a flowchart illustrating the process by which the monitoring module synchronizes the static configuration and status information between on-duty and non-on-duty gateway stations in this invention.

[0048] Figure 4 This is a flowchart illustrating the routing keep-alive algorithm in this invention.

[0049] Figure 5 This is a flowchart illustrating the state monitoring and decision-making process in this invention. Detailed Implementation

[0050] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0051] Combination Figure 1 The present invention provides a switching device for access network and core network of a multi-satellite and multi-site system, which includes a monitoring module, a decision-making module, an execution module and a protection module.

[0052] The monitoring module is used for status synchronization and real-time monitoring;

[0053] The decision module is used to make access network switching decisions;

[0054] The execution module is used for switching execution and adjusting parameters;

[0055] The aforementioned protection module is used to ensure the continuity of the core network and the validity of data.

[0056] As a specific example, the protection module includes a route keep-alive unit and a data deduplication unit;

[0057] The routing keep-alive unit is used to maintain core network routing using a distributed hash table algorithm;

[0058] The data deduplication unit is used to filter duplicate data using the Bloom filter algorithm.

[0059] Combination Figure 2 The method for switching between the access network and the core network of a multi-satellite, multi-site system provided by this invention includes the following core components:

[0060] I. Configuration Status Synchronization

[0061] To ensure consistent configuration status across the access and core networks of different gateway stations, parameter synchronization software is set up as the central repository for storing configuration parameters for each gateway station. Each gateway station periodically uploads its latest operating parameters, including those for the baseband pool, core network elements, and radio frequency units, to the configuration synchronization software. The system pushes all satellite ephemeris and orbital parameters to the network management systems of each gateway station. When a switchover is required, the network management system retrieves the latest configuration parameters from the configuration synchronization software and distributes them to the corresponding software.

[0062] like Figure 3 As shown, the parameter synchronization process includes: each gateway station periodically uploads its working parameters to the configuration synchronization software; the configuration synchronization software maintains a unified parameter database; when a switchover is triggered, the target gateway station pulls the latest configuration parameters from the configuration synchronization software.

[0063] II. Switching Detection Phase

[0064] After system startup, the switching detection module sends detection signals to the feed link and ground gateway station at set time intervals. The satellite baseband pool monitors downlink signal strength, bit error rate, and other indicators of the feed link in real time. For example, signal strength is checked every 100ms. If the signal strength is below -115dBm in five consecutive checks, a preliminary assessment indicates an anomaly in the link. Simultaneously, at the ground gateway station, system performance indicators (such as CPU utilization, memory usage, and connection status with the core network) are monitored to determine if it is functioning correctly. If CPU utilization consistently exceeds 90% and a connection interruption with the core network occurs, the ground gateway station is considered to have failed.

[0065] III. Switching Decision Phase

[0066] The handover decision module, based on monitored key performance indicators and the target available resources of each candidate gateway station, comprehensively considers multiple influencing factors and uses a weighted algorithm to calculate a comprehensive score for each candidate path, selecting the path with the highest score as the handover target. Influencing factors include the load status of each gateway station, communication quality, distance to the user terminal, and relevant parameters of the satellite link. The weights of each factor in the weighted algorithm are pre-set or dynamically adjusted according to the system application scenario.

[0067] The calculation formula for the multidimensional weighted evaluation model is as follows:

[0068]

[0069] in, A comprehensive score for candidate paths; The signal quality factor is calculated based on a nonlinear mapping of the received signal strength indication and the signal-to-noise ratio. The system load factor represents the resource carrying capacity of the target gateway station, calculated according to... The calculation is equal to 1 minus the current load rate; To switch the cost factor, representing the cost of route reconstruction, it is determined in real time by querying the topological distance between the source node and the target node through a distributed hash table network; , , They are respectively , , The corresponding weights satisfy .

[0070] For example, the current data transmission rate of the backup power supply link is 100 Mbps, and the load rate is 30%. The available ground gateway station A has a processing capacity of 1000 data packets per second, and its connection quality with the core network is good. Then, each backup path is comprehensively evaluated according to pre-set weights (e.g., load weight 0.4, communication quality weight 0.3, processing capacity weight 0.2, distance weight 0.1). Taking the backup power supply link as an example, assuming its communication quality score is 8 points (out of 10) and its load score is 7 points, its comprehensive score is calculated using the formula: Comprehensive Score = Load Score × 0.4 + Communication Quality Score × 0.3 + Distance Cost Score × 0.3. The comprehensive scores of all backup paths are compared, and the path with the highest score is selected as the handover target.

[0071] IV. Router Keep-alive and Core Network Continuity Assurance

[0072] Before the switchover, the route keep-alive module starts the route keep-alive algorithm. Figure 4For example, satellite node S originally communicated with ground node G via a feeder link. Now, the link has failed, and it needs to switch to a backup link to communicate with ground node H. Satellite node S first marks the currently buffered untransmitted data and records the data sequence number. Then, it sends a route update message to ground node H through the DHT network. The message contains its own identifier and routing information from previous communication with ground node G (such as a list of intermediate nodes and routing metrics). Upon receiving the route update message, ground node H constructs a new route with satellite node S based on the information in the message, combined with its maintained neighbor information and historical routing records. For example, ground node H finds an intermediate node directly connected to itself based on the list of intermediate nodes provided by satellite node S, and obtains complete routing information by interacting with this intermediate node, quickly establishing a new route. Simultaneously, ground node H sends an acknowledgment message to satellite node S, informing it that the route has been established. After receiving the acknowledgment message, satellite node S begins retransmitting the marked data according to the new route.

[0073] The above explanation uses the Kademlia protocol as an example, but this invention is also applicable to the Chord protocol (based on a ring structure) or the Pastry protocol (based on prefix routing); only the query logic of the routing table needs to be adjusted. Before the switchover, the route keep-alive module starts the route keep-alive algorithm.

[0074] V. Switching Execution Phase

[0075] like Figure 5 As shown, the handover execution module executes specific handover operations based on the handover target selected by the handover decision module. To achieve automated scheduling of multi-satellite heterogeneous networks, the task identifier data structure must be sufficiently general and refined. This data structure can be divided into three core parts: basic task information, target resource information, and key configuration instructions, which together constitute a complete task instruction, as shown in Table 1.

[0076] Table 1 Scheduling Task Plan

[0077]

[0078] In the event of a ground gateway station handover, ground nodes reconfigure their connection parameters with the new gateway station, such as IP address and port number, and notify relevant user terminals and core network equipment of the handover. Simultaneously, the new gateway station's core network sends handover notification messages via satellite network to other relevant nodes (such as other satellite nodes in the satellite constellation and ground core network nodes), informing them of the new communication path.

[0079] VI. Data Deduplication Stage

[0080] During data transmission, the data deduplication module operates at both the sending and receiving ends, both before and after the handover. At the sending end, for each data block to be sent, its hash value is first calculated. For example, the SHA-256 algorithm is used to calculate the hash value of the data block. Then, the hash value is marked using a Bloom filter. The Bloom filter contains multiple hash functions, each corresponding to a position in a bit vector. After a hash value is calculated using multiple hash functions, the corresponding bit vector position is set to 1.

[0081] At the receiving end, upon receiving a data block, its hash value is calculated and then queried using a Bloom filter. If all bit vector positions corresponding to the hash value in the Bloom filter are 1, the data block is considered potentially duplicate data (there is a certain false positive rate, but it is extremely low). Further verification of the data block's content confirms whether it is a duplicate. If a duplicate is confirmed, the data block is discarded; otherwise, it is received and processed.

[0082] Example

[0083] In this embodiment, the core of the core network continuity assurance step lies in using a distributed hash table (DHT) algorithm to replace the traditional periodic flooding routing protocol, in order to solve the routing convergence delay problem under the highly dynamic topology of satellite networks. The following is a combination of... Figures 1-5 The present invention’s “Multi-satellite inter-network collaborative switching method based on DHT and Bloom filter” is described in detail through a specific multi-satellite inter-network communication scenario.

[0084] 1. Scene Construction and Initial State

[0085] This embodiment constructs a simulated multi-satellite inter-network communication environment to verify the effectiveness of the method of the present invention.

[0086] (1) Space segment: Includes two high-orbit satellites (Sat-A and Sat-B). Sat-A is currently the primary service satellite, and its onboard baseband processing unit uses the Xilinx RFSoC ZU49DR chip.

[0087] (2) Ground segment: Includes two off-site gateway stations. The primary gateway station (GW-A) is located in the Shanghai data center, and the backup gateway station (GW-B) is located in the Hefei data center.

[0088] (3) Hardware configuration: GW-A and GW-B are both equipped with Intel Xeon Silver 4314 server CPU and NVIDIA ConnectX-7 SmartNIC.

[0089] (4) Network topology: GW-A and GW-B are connected to the core network via optical fiber, and a DHT overlay network based on the Kademlia protocol is established between them.

[0090] (5) Initial parameters: Link-1 signal strength is -105dBm, GW-A core network CPU utilization is 75%, and the core network routing table has 5000 entries.

[0091] 2. Fault Triggering and Status Monitoring

[0092] When the monitoring module detects that the signal strength of the power supply link is continuously lower than the threshold within a preset window period, the signal strength of Link-1 begins to drop sharply.

[0093] (1) Monitoring Mechanism: The monitoring module collects data at an adaptive frequency (currently 100ms / time). When the received signal strength indication is below the link budget threshold for three consecutive times and the bit error rate (BER) exceeds... At that time, the system determined that Link-1 had entered a "sub-healthy" state.

[0094] (2) Data synchronization: At the moment of judgment, the system immediately retrieves the real-time status of the backup gateway station GW-B (located in a remote location) through the shared storage mechanism. The data shows that the current load rate of GW-B is 20%, and the link quality is excellent.

[0095] 3. Multidimensional weighted decision-making process

[0096] In traditional satellite handover, the single "signal strength" indicator often causes the terminal to bounce repeatedly between Shanghai (rain attenuation zone) and surrounding cities (signal zone) like a ping-pong ball (i.e., "ping-pong handover").

[0097] This embodiment demonstrates how the present invention makes optimal "site-wide" decisions by using a multi-dimensional weighted algorithm combined with DHT routing status.

[0098] (1) Environmental perception and data acquisition

[0099] exist At that moment, the monitoring module reported abnormal data:

[0100] Current link (Shanghai GW-A): Signal strength from sudden drop (Affected by strong convective clouds in Shanghai during spring), the bit error rate (BER) rose to [missing value]. .

[0101] Candidate link (Hefei GW-B): Signal strength stabilized at The current CPU load rate is .

[0102] (2) Quantitative calculation of decision factors

[0103] The decision-making module is switched on and started. It reads the preset weight matrix (for the rainy scenario in Shanghai, the system automatically increases the signal weight) and scores the candidate paths (out of 10).

[0104] A. Signal quality factor ( )

[0105] Meaning: The physical survivability of the link.

[0106] Calculation: Nonlinear mapping based on Received Signal Strength Indication (RSSI) and Signal-to-Noise Ratio (SINR).

[0107] Data in this example:

[0108] Shanghai GW-A: Due to severe rain attenuation, the score is only 2.0.

[0109] Hefei GW-B: Excellent link performance, rated 9.0.

[0110] B. System load factor ( )

[0111] Meaning: The resource carrying capacity of the target gateway station.

[0112] calculate: .

[0113] Data in this example:

[0114] The load factor of Hefei GW-B is 20%, therefore the score is 8.0.

[0115] C. Switching cost factors ( )

[0116] Meaning: This is the key difference between this patent and traditional methods. It represents the overhead of route reconstruction.

[0117] Calculation logic: The decision module queries the topological distance between the source node (Shanghai) and the target node (Hefei) in real time through the DHT network.

[0118] If the two are close to each other on the DHT ring (small XOR value), the routing table synchronization is fast, the cost is low, and the score is high.

[0119] If long-distance synchronization across the core network is required, the cost is high and the score is low.

[0120] Data in this example:

[0121] The query results show that the Shanghai and Hefei nodes are only 3 hops apart in the DHT coverage network, and the estimated route synchronization time is <15ms.

[0122] Therefore, the switching cost is extremely low, scoring 8.5.

[0123] (3) Weighted fusion and judgment

[0124] System call weighting formula:

[0125]

[0126] Considering the current severe weather in Shanghai, the system dynamically adjusts the weights as follows:

[0127] (Signal) = 0.5 (Prioritize link protection)

[0128] (Load) = 0.2

[0129] (Cost) = 0.3

[0130] Calculation process:

[0131]

[0132] Comparative analysis:

[0133] Maintaining the original link (Shanghai) score: only 3.2 (due to extremely poor signal and reduced effective bandwidth caused by high bit error rate). Switching to Hefei score: 8.65.

[0134] (4) Final decision output

[0135] because If the difference is greater than the preset hysteresis threshold (set to 2.0), the system determines that: "feeder network integration" switching will be performed, and the target node will be locked as Hefei gateway station (GW-B).

[0136] 4. Feeder network collaborative execution and route keep-alive

[0137] exist At any given time, the execution module starts and automatically loads the "Sat-A_Inter-network_Service Recovery" script, along with the antenna RF, intermediate frequency matrix, baseband resource pool, and core network parameters.

[0138] Router keep-alive (DHT mechanism):

[0139] (1) Pre-synchronization: Before GW-A is completely offline, it directly writes the hash value and routing information of 100 cached unacknowledged data packets into the routing agent process of GW-B through the DHT network (Kademlia protocol).

[0140] (2) Physical reconstruction: After the CPU of GW-B receives the physical signal, it directly reads the routing information synchronized by DHT and directly operates the register of the ConnectX-7 network card to update the forwarding table.

[0141] (3) Effect: The route reconstruction process does not require a full network broadcast, and physical measurements show that the route convergence time is only 18ms.

[0142] 5. Data deduplication verification

[0143] During the handover transition period ( Due to routing oscillations, some data packets (PacketID: 0x1001~0x1005) appeared simultaneously on both the old and new links.

[0144] Bloom filter operation:

[0145] (1) Hash calculation: The SmartNIC hardware circuit of GW-B calculates the SHA-256 hash value of the incoming data packet.

[0146] (2) Bitmap lookup: Hardware lookup of the bitmap memory of the Bloom filter (located in the network card's SRAM).

[0147] (3) Hardware discard: When the hash values ​​of data packets 0x1001 and 0x1003 are detected to be marked in the bitmap, the hardware logic gate directly discards the physical data packet and no longer occupies the memory buffer.

[0148] (4) Upload processing: Only non-duplicate packets such as 0x1002 and 0x1004 are uploaded to the server CPU for processing.

[0149] 6. Experimental Data and Conclusions

[0150] Through the above process, this embodiment has achieved significant technical effects:

[0151] (1) Service interruption time: Through the pre-synchronization mechanism of the DHT algorithm, the CPU computing load of the core network router is physically reduced, and the routing convergence time is reduced from 500ms (causing service interruption) in the traditional method to 20ms (service is not aware of it), which proves that the algorithm improves the physical communication quality.

[0152] (2) Data redundancy rate: During the switching window, the proportion of redundant data packets decreased from 40% to less than 0.1% (with only a very low Bloom filter misjudgment rate).

[0153] (3) Conclusion: This invention proves its effectiveness in ensuring the communication continuity of multi-satellite network systems.

[0154] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for switching between the access network and the core network of a multi-satellite, multi-site system, characterized in that, include: Status synchronization and real-time monitoring steps: Synchronize the static configuration and status information between the guarded and unguarded gateway stations; Real-time monitoring of the status of the power supply link and gateway station to obtain key performance indicators; when the key performance indicators meet the preset switching conditions, the access network switching decision steps are executed. Access network handover decision steps: Based on the key performance indicators and target available resources, multiple influencing factors are comprehensively considered, a weighted algorithm is used to calculate the score of each candidate path, and the path with the highest score is selected as the handover target. The target gateway station corresponding to the candidate path with the highest score is determined as the handover target, and the source node and target node of the current communication are marked. Handover execution and parameter adjustment steps: Based on the access network handover decision, automatically execute the handover operation of the primary and backup gateway station parameter configurations, and dynamically adjust the communication-related parameters; Core network continuity and data validity assurance steps: During the handover process, the source node sends routing update messages to the target node based on a distributed hash table algorithm to ensure the routing continuity of the core network, and filters duplicate data packets based on a Bloom filter algorithm to ensure the validity of data transmission.

2. The method for switching between the access network and the core network of a multi-satellite, multi-site system according to claim 1, characterized in that, In the state synchronization and real-time monitoring steps, state synchronization between gateway stations is achieved through a dedicated communication link or a shared storage mechanism; the real-time monitoring includes signal strength, bit error rate, gateway station processing capacity, and connection status with the core network.

3. The method for switching between the access network and the core network of a multi-satellite, multi-site system according to claim 1, characterized in that, In the access network handover decision-making step, the influencing factors include: The load status, communication quality, distance from user terminals, and relevant parameters of satellite links of each gateway station; the weights of each factor in the weighted algorithm are preset or dynamically adjusted according to the system application scenario.

4. The method for switching between the access network and the core network of a multi-satellite, multi-site system according to claim 1, characterized in that, In the access network handover decision-making step, a multi-dimensional weighted evaluation model is used to calculate the score of each candidate path. The calculation formula of the multi-dimensional weighted evaluation model is as follows: in, A comprehensive score for candidate paths; The signal quality factor is calculated based on a nonlinear mapping of the received signal strength indication and the signal-to-noise ratio. The system load factor represents the resource carrying capacity of the target gateway station, calculated according to... The calculation is equal to 1 minus the current load rate; To switch the cost factor, representing the cost of route reconstruction, it is determined in real time by querying the topological distance between the source node and the target node through a distributed hash table network; , , They are respectively , , The corresponding weights satisfy .

5. The method for switching between the access network and the core network of a multi-satellite, multi-site system according to claim 1, characterized in that, In the switching execution and parameter adjustment steps, a parameter configuration sequence script uniformly labeled with "satellite identifier - network identifier - mission category" is used, which supports parallel processing of subsystem scripts to execute the switching; the communication-related parameters include communication frequency, power and network interface settings; The data structure of the parameter configuration sequence script includes: (1) Basic task information: including task number and task type; the task number is a globally unique task identifier; the task type defines the nature of the task, including power supply link switching, measurement and control command injection, core network element reconfiguration, and service traffic scheduling. (2) Target resource information: including satellite identifier and network identifier; the satellite identifier is used to uniquely identify a satellite; the network identifier is used to identify the constellation or network to which the satellite belongs; (3) Key configuration instructions: including power supply link configuration, telemetry and control link configuration, access network configuration and core network configuration; power supply link configuration includes carrier frequency, modulation and coding scheme, time slot / frame structure; telemetry and control link configuration includes telemetry and control mode, telemetry parameters; access network configuration includes beam ID, user group policy; core network configuration includes network element function, PDU session anchor point, update routing rules, quality of service 5QI parameters.

6. The method for switching between the access network and the core network of a multi-satellite, multi-site system according to claim 1, characterized in that, In the core network continuity and data validity assurance steps, the routing continuity of the core network is guaranteed based on a distributed hash table algorithm, specifically as follows: The source node marks the cached unsent data and sends a route update message to the target node through a distributed hash table network. The distributed hash table algorithm includes the Kademlia protocol, Chord protocol, or Pastry protocol. The target node reconstructs the route based on the route update message, its own neighbor information, and historical routing records.

7. The method for switching between the access network and the core network of a multi-satellite, multi-site system according to claim 1, characterized in that, In the core network continuity and data validity assurance steps, the validity of data is guaranteed based on the Bloom filter algorithm, specifically as follows: The sending end calculates the hash value of the data block and marks the hash value through a Bloom filter; when the receiving end receives the data block, it calculates its hash value and queries the Bloom filter. If it determines that the hash value already exists, it discards the data block; otherwise, it receives and processes it.

8. The method for switching between the access network and the core network of a multi-satellite, multi-site system according to claim 1, characterized in that, In the core network continuity and data validity assurance steps, route keep-alive is managed using hierarchical routing tables: The routing table maintained by the node is divided into upper-layer summary routing information and lower-layer detailed routing information; When updating routes, the direction is quickly determined first by using summary routing information, and then the route is precisely adjusted based on detailed routing information.

9. A switching device for the entire site between the access network and the core network in a multi-satellite, multi-site system, characterized in that, The device is used to perform the site-wide handover method between the access network and the core network as described in any one of claims 1 to 8, the device comprising: The monitoring module is used for status synchronization and real-time monitoring; The decision module is used to make access network switching decisions; The execution module is used for switching execution and adjusting parameters; The aforementioned protection module is used to ensure the continuity of the core network and the validity of data.

10. The access network and core network switching device for a multi-satellite, multi-site system according to claim 9, characterized in that, The protection module includes: The routing keep-alive unit is configured to maintain core network routes using a distributed hash table algorithm. The data deduplication unit is configured to use the Bloom filter algorithm to filter duplicate data.

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