Inter-satellite dynamic networking communication strategy

Abstract

The invention belongs to the field of aircraft measurement and control communication, and relates to an inter-satellite dynamic networking communication strategy. The inter-satellite dynamic networking communication strategy comprises the steps of establishing a five-layer protocol stack suitable for a spacecraft collaborative networking scene, providing an improved transmission layer transmission strategy (SC-TCP / IP) based on a TCP / IP standard protocol, providing an improved wireless network layer routing strategy based on an OSPF, and providing a wireless link layer dynamic time slot allocation access control strategy.

Description

Technical Field

[0001] The present invention relates to an intersatellite network which belongs to the field of aircraft measurement and control communication and is applied to the simultaneous communication of distributed multiple types of space aircraft nodes. Background Art

[0002] At present, the research on multi-aircraft communication is developing in the direction of networking, collaboration, intelligence, and strong adaptability. Distributed multi-type space aircraft nodes have different application requirements, including comprehensive observation of key targets, continuous tracking of moving targets, and continuous coverage of key areas. There is a need for self-organizing networks between aircraft on different orbits, between aircraft on the same orbit but different orbital positions, and between aircraft on the same orbit and at the same orbital position. The networking system composed of aircraft networks improves the situational awareness, flight collaboration, and flight efficiency of aircraft, and requires high adaptability and reliability. The self-organizing network access control protocol can ensure the correct transmission of information data and avoid the waste of increasingly scarce channel resources. The multiple access protocols that can be used in aircraft networks mainly include: contention-based multiple access technology, non-contention-based multiple access technology and hybrid multiple access technology. The papers "Inter-satellite Communications for Small Satellite Systems. International Journal of Interdisciplinary Telecommunications and Networking" and "The Performance Evaluation of Distributed Inter-satellite Communication Protocols for Cube Satellite Systems" proposed the CSMA / CA protocol suitable for satellite formation flying. The protocol adopts the RTS / CTS mechanism and is equipped with smart antennas with different functions at the physical layer to adapt to different formation flying modes. However, the simulation results show that the MAC protocol proposed in the paper only performs well in networks that do not require frequent communication. Compared with the contention-based protocols that cannot avoid conflicts, the fixed allocation time division multiple access (TDMA) protocol has better performance in network throughput and channel utilization, and is more suitable for aircraft self-organizing networks. The paper "a TDMA-based MAC protocol for reliable broadcast in VANET" proposes a TDMA protocol that uses a fixed time slot allocation scheme. Nodes complete fixed time slot allocation through information exchange within the cluster and network collaboration. There is no central node. After completing the time slot allocation, the nodes can always use the allocated inherent time slots for data transmission. The paper "a collision-free MAC protocol for UAVs Ad-Hoc networks" improves the fixed time slot allocation method proposed above and proposes a CF-MAC protocol. This protocol performs carrier monitoring before sending a time slot occupancy application, reducing the probability of collision when multiple nodes send applications in the same time slot.However, the fixed allocation TDMA protocol has some reserved time slots where no nodes transmit data, which will cause the problem of time slot waste, and this time slot is called an idle time slot or idle time slot, and the idle time slot will lead to a decrease in channel utilization. The document "Idle Time Slot Reservation TDMA Protocol for Flying Ad Hoc Networks" designs an ISR-TDMA protocol that can efficiently use idle time slots. This protocol adds a random number field to the frame structure and uses reservation negotiation instead of backoff competition, so that nodes can use idle time slots without conflict, thereby reducing the overhead of idle time slot use and effectively improving channel utilization and network throughput performance. However, the ISR-TDMA protocol only considers single-hop scenarios where nodes can communicate with each other, and cannot solve the problem of idle time slot reservation in multi-hop scenarios. The document "A Dynamic TDMA Protocol for Flight Ad Hoc Network Applications" proposes a dynamic TDMA protocol based on node priority, the NP-TDMA protocol. The protocol adopts a dynamic allocation strategy and introduces a node priority judgment mechanism when the node applies for a service time slot, thereby achieving the purpose of giving high-priority nodes priority access to the channel. However, the NP-TDMA protocol divides the time frame period into two parts: the control period and the service period, which reduces the service throughput during the time slot occupation period. Summary of the invention

[0003] 1. Technical issues to be resolved

[0004] In view of the deficiencies of the above-mentioned prior art, the present invention proposes a dynamic inter-satellite networking communication strategy, which realizes conflict-free communication among distributed multi-type spacecraft nodes, solves the problem that the existing OSI seven-layer model protocol stack is not suitable for spacecraft due to its high complexity, and realizes dynamic allocation of time slots to improve network throughput and channel utilization.

[0005] (II) Technical solution

[0006] A dynamic inter-satellite networking communication strategy includes: establishing a five-layer protocol stack suitable for spacecraft collaborative networking scenarios, providing a transport layer transmission strategy (SC-TCP / IP) based on an improvement of the TCP / IP standard protocol, providing a wireless network layer routing strategy based on an improvement of OSPF, and providing a wireless link layer dynamic time slot allocation access control strategy.

[0007] The present invention also proposes a five-layer protocol stack suitable for spacecraft collaborative networking scenarios. Based on the general OSI seven-layer model, the protocol stack levels are divided into application layer, transport layer, wireless network layer, wireless link layer and physical layer in sequence.

[0008] The present invention also proposes an improved transport layer transmission strategy (SC-TCP / IP) based on the TCP / IP standard protocol. The transport layer reads and splits the data source packet transmitted from the application layer and then encapsulates it. The implementation of the SC-TCP / IP strategy mainly consists of three processes, namely, the data transmission process, the reception confirmation process and the connection termination process. Each process needs to be completed by the sender and the receiver together.

[0009] The present invention also proposes a wireless network layer routing strategy based on OSPF improvement. For highly dynamic aircraft topology networks, a routing protocol based on the OSPF protocol improvement is adopted to establish a fast-converging routing table, including link status information and network topology information, to provide guidance for the forwarding of low-speed services and the narrow-beam antenna pointing of high-speed networks.

[0010] (III) Beneficial effects

[0011] The present invention provides an inter-satellite dynamic networking communication strategy, including: establishing a five-layer protocol stack suitable for spacecraft collaborative networking scenarios, providing a transport layer transmission strategy (SC-TCP / IP) based on an improvement of the TCP / IP standard protocol, providing a wireless network layer routing strategy based on an improvement of OSPF, and providing a wireless link layer dynamic time slot allocation access control strategy.

[0012] 1. The five-layer protocol stack suitable for spacecraft collaborative networking scenarios proposed in the present invention completes the detailed division of functions of each layer for intersatellite dynamic networking scenarios. The wireless network layer and the wireless link layer are significantly different from the Internet protocol stack, providing a standard protocol stack system for multiple types of spacecraft networks.

[0013] 2. The improved transport layer transmission strategy based on the TCP / IP standard protocol (SC-TCP / IP) proposed in the present invention realizes flow control and error retransmission functions, and compared with the TCP / IP standard protocol, reduces the redundant fields of the data packet header, reduces the channel occupancy and complexity, and saves on-device processing resources.

[0014] 3. The improved wireless network layer routing strategy based on OSPF proposed in the present invention provides adaptive routing functions for various types of space aircraft networks, and periodically maintains network topology information to ensure that the wireless aircraft network can grasp the network situation in real time.

[0015] 4. The wireless link layer dynamic time slot allocation access control strategy proposed in the present invention solves the problem of channel resource waste caused by multiple forwarding and idle time slots during flooding broadcasting, improves the real-time performance and network throughput of network information interaction, and improves the security of the node access network process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1It is a schematic diagram of a five-layer protocol stack suitable for spacecraft collaborative networking scenarios of the present invention.

[0017] Figure 2 The transport layer of the present invention is based on the improved transport layer transmission strategy (SC-TCP / IP) of the TCP / IP standard protocol to read and split the data source packet transmitted from the application layer and then encapsulate it. The encapsulated message format diagram

[0018] Figure 3 It is a flow chart of the transport layer data transmission process and reception confirmation process of the transport layer transmission strategy (SC-TCP / IP) based on the TCP / IP standard protocol improvement of the present invention.

[0019] Figure 4 It is a schematic diagram of the transport layer connection termination process of the transport layer transmission strategy (SC-TCP / IP) based on the TCP / IP standard protocol improvement of the present invention.

[0020] Figure 5 It is a schematic diagram of the time frame structure of the dynamic time slot allocation strategy of the present invention.

[0021] Figure 6 It is a flow chart of the dynamic time slot allocation access control strategy of the present invention. DETAILED DESCRIPTION

[0022] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings.

[0023] An exemplary intersatellite dynamic networking communication strategy of the present invention includes: establishing a five-layer protocol stack suitable for spacecraft collaborative networking scenarios, providing a transport layer transmission strategy (SC-TCP / IP) based on the TCP / IP standard protocol improvement, providing a wireless network layer routing strategy based on OSPF improvement, and providing a wireless link layer dynamic time slot allocation access control strategy.

[0024] The exemplary five-layer protocol stack of the present invention is applicable to the spacecraft collaborative networking scenario, and the protocol stack architecture is as shown in the attached Figure 1 As shown in the figure, based on the general OSI seven-layer model, the protocol stack layers are divided into application layer, transport layer, wireless network layer, wireless link layer and physical layer. The functions of each layer are as follows:

[0025] The application layer is the highest layer of the system and directly provides services for application processes. Its role is to achieve communication between multiple system application processes and complete a series of services required for business processing. On spacecraft, the main functions of the application layer include mission planning, mission information assignment, business information classification and processing, etc.

[0026] The transport layer provides end-to-end (end-user to end-user) transparent and reliable data transmission services for the upper layer. The basic function of the transport layer is to receive data from the upper layer, divide the data into small units when necessary, and then send them correctly to the other end. The transport layer is a true end-to-end layer, and all processing is carried out from the source end to the destination end.

[0027] There may be many data links or communication subnets between two nodes communicating in the network. The task of the wireless network layer is to select appropriate inter-network routing and switching nodes to ensure timely data transmission. On the aircraft, the wireless network layer receives the services to be transmitted from the upper layer, plans the shortest transmission path for it according to the destination node and routing table, and encapsulates the upper layer data into data packets, which contain the IP addresses of the source node, the next hop node and the destination node. Address resolution and routing are important functions of the wireless network layer. The network layer can also implement congestion control, internet interconnection and other functions.

[0028] The data link layer in the Internet protocol stack establishes data links between adjacent nodes on the basis of the bit stream service provided by the physical layer, and provides error-free transmission of data frames on the channel through error control. The functions of this layer include: physical address addressing, data framing, flow control, data error detection, retransmission, etc. Different from the function of the data link layer in the Internet protocol stack, the wireless link layer used in intersatellite networking no longer provides physical addressing services, and replaces the link layer MAC address addressing with the network layer IP address fixed node ID to save resources on the device. At the same time, the main functions of the wireless link layer include network topology information maintenance, node network authentication, authentication, node access control, node network exit management, channel quality monitoring, priority scheduling, etc. At the same time, in view of the sharing problem of wireless channels, resource scheduling management is completed through time slot allocation to solve the terminal's access to the channel.

[0029] The physical layer provides a virtual bit pipe for transmitting bit streams between any pair of nodes connected by a physical communication channel. At the sending end, it converts the bit stream received from the higher layer into a signal suitable for transmission on the physical channel, and at the receiving end, it restores the signal to the transmitted bit stream.

[0030] An exemplary transport layer transmission strategy (SC-TCP / IP) based on the TCP / IP standard protocol of the present invention is that the transport layer reads and splits the data source packet transmitted from the application layer and then encapsulates it. The format of the encapsulated message is as shown in the attached figure. Figure 2 As shown, the message is parsed as follows:

[0031] Source node IP: 16 bits in length, in the format of subnet ID and source node ID, i.e. "subnet ID. source node ID". Subnet ID indicates the cluster ID of the node. Generally, backbone nodes are far apart, and each backbone node and its non-backbone nodes that can communicate within 5 hops form a cluster (tentative), i.e. a subnet. The cluster ID is initially configured on the backbone node, and is broadcasted by the backbone node to inform the nodes in the cluster. The source node ID is the node ID that generates and sends service data in the subnet.

[0032] Destination node IP: 16 bits in length, in the format of subnet identification code and destination node identification code, i.e. "subnet ID.destination node ID". The destination node ID is the node ID of the subnet to receive the service data, and is valid when the MOD flag is 1.

[0033] Service type ID: 4 bits in length, indicating that the service type belongs to ground command information, low-speed intelligence information, high-speed intelligence information, network access authentication information or network exit broadcast information.

[0034] Data segment sequence number: 16 bits in length, indicating the segment sequence number of the current transmission when the business data is transmitted in segments. When the business data does not need to be segmented, the data segment sequence number is 0.

[0035] MOD: 1 bit in length, service transmission mode flag. A MOD of 0 indicates multicast transmission, which means that the service is broadcast by the source node to all nodes in the cluster, and the destination node ID should be 0. A MOD of 1 indicates unicast transmission, which means that the service is broadcast by the source node to a certain destination node, and the destination node ID is valid.

[0036] ACK: 1 bit in length, confirmation message, valid when the MOD flag is 1, only in unicast transmission mode, the destination node needs to respond to the service information. The ACK in the source node message is set to 0, and the ACK in the destination node reply message is set to 1.

[0037] FIN: 1 bit in length, ends the message, is valid when the data segment sequence number is not 0, and is set to 1 when the source node sends the last data segment.

[0038] Confirmation number: 16 bits in length, valid when ACK is 1, indicating that the target node expects to receive the next data segment from the source node.

[0039] Message length: 32 bits in length, indicating the length of the entire transport layer message.

[0040] Checksum: 16 bits in length, performs checksum calculation on the transport layer message and is verified by the target node.

[0041] Business data: variable length, original business data segmented, when the destination node sends a reply message, the data segment is empty.

[0042] The implementation of SC-TCP / IP strategy mainly consists of three processes: data transmission process, reception confirmation process and connection termination process. Figure 3 and attached Figure 4 As shown in the figure, each process needs to be completed by the sender and the receiver. In the data transmission stage, the source node will encapsulate the received data into segmented messages suitable for transmission. The format is as shown in the attached figure. Figure 2 As shown, it is sent to the destination node. When the destination node receives the segment, it will send an ACK confirmation message. The format is as shown in the attached Figure 2 As shown in the figure, when the source node receives it, it sends the next segment information. If it does not receive the confirmation message, it means that the destination node has not received the previous segment, so it resends the previous segment and waits for confirmation. This mechanism is used to ensure reliable connection and error retransmission. In the connection termination phase, a two-way handshake process needs to be completed. The sending node sends a message to the receiving node to mark the end of the transmission, indicating that the data has been sent, and waits for the receiving node to send an ACK confirmation message. At this point, both the sending node and the receiving node confirm that the transmission is completed.

[0043] The exemplary wireless network layer routing strategy based on OSPF improvement of the present invention, for the highly dynamic aircraft topology network, adopts the routing protocol based on OSPF protocol improvement to establish a fast convergence routing table, including link state information and network topology information, to provide guidance for the forwarding of low-speed services and the narrow beam antenna pointing of high-speed networks. The specific method is as follows:

[0044] 1) Routing establishment: After the routing protocol is started, each node periodically broadcasts Hello packets to find neighboring nodes. After receiving the Hello packet, the node replies with a Hello message to confirm that two-way communication is possible and establish a neighbor relationship.

[0045] 2) Link state information synchronization: After establishing a neighbor relationship, the two nodes exchange LSA (Link State Table) in the network. The LSA contains the neighbor information table of all nodes in the network currently recorded by the sending node. Through the LSA interaction of each node in the network, the link information table stored in each node can quickly converge, and finally form an LSDB (Link State Database) containing complete link state information of the network.

[0046] 3) Calculate the route; after LSDB synchronization is completed, the nodes in the network have the same understanding of the network structure, and each node can independently calculate the shortest path from the source node to the destination node using the Dijkstra algorithm based on the LSDB information.

[0047] 4) Route recovery: When a node fails or a topology change causes the original path to be interrupted, if the faulty node information in the node LSDB is not updated within a few time frame periods, the node can be judged to be faulty. The node quickly updates the neighbor relationship, deletes the path related to the faulty node, adaptively finds the best route under the current topology, and completes route recovery.

[0048] 5) Network topology information maintenance: Each node periodically broadcasts NSA (node ​​location information table), where NSA contains the location coordinates of all nodes in the network currently recorded by the sending node. Through the NSA interaction of each node in the network, according to the dynamic time slot allocation strategy, the network topology information table stored in each node can quickly converge after several broadcast cycles, and finally form an NSDB (network topology database) containing the complete network topology information.

[0049] The exemplary dynamic time slot allocation access control strategy of the present invention is shown in the attached Figure 6 , including dynamic time slot allocation strategy, idle time slot reservation strategy, and node access strategy.

[0050] 1) Dynamic time slot allocation strategy The specific scheme is as follows: The time frame structure is based on TDMA, as shown in the attached Figure 5As shown, each time frame period consists of X time slots, and the time slot length is 10ms. Each node in the network occupies its own time slot for communication according to the time slot allocation table of this period. The time slots occupied by the nodes are busy slots, and the unoccupied time slots are idle slots. If the nodes in the cluster are not in a fully connected state, the dynamic time slot allocation method is as follows: if the number of nodes in the cluster is N, the number of busy time slots in the time frame structure is 2N, and the number of idle time slots is X-2N. Each node in the cluster calculates the coordinates of the network topology center based on the NSDB (network topology database) stored in itself. Each node adds nodes with the same number of hops to the network center to the same level set based on the number of hops from itself to the network center. The nodes in the same set are called the same level. Nodes within one hop from the network center belong to level 0, and nodes within two hops from the network center belong to level 1, and so on. Each node occupies the first N busy time slots in sequence according to the principle of large to small levels and small to large node IDs in each level set, and then occupies busy slots N+1 to 2N in sequence according to the principle of small to large levels and large to large node IDs in each level set. The nodes send low-speed services, high-speed services or routing signaling services in their respective occupied time slots in turn. There is no interference between low-speed services or routing signaling and high-speed services in the frequency band and they can be sent simultaneously. The nodes select the services with the highest priority in the queue in their own occupied time slots to send low-speed services and routing signaling. The nodes adjust the directional antenna beam to point to the node currently occupying the time slot in the time slots not occupied by themselves. The time slot allocation process is based on NSDB. In order to save channel resources, each node has a period of 10 time frames and broadcasts NSA routing signaling every 10 time frames. The nodes adaptively update the time slot allocation results according to the latest NSDB and occupy the time slots according to the updated time slot allocation results starting from the next time frame.

[0051] During the time slot allocation process, the network within the cluster is divided into levels according to the star topology. The network nodes occupy time slots in the order from the outer layer to the center and then from the center to the outer layer, ensuring that the nodes with the farthest hop interval can also complete data interaction within a fixed time. This not only makes up for the static nature of the OSPF routing protocol, but also solves the problem of resource waste caused by multiple forwarding during flood broadcasting.

[0052] 2) The specific method of idle time slot reservation strategy is as follows: (1) According to the above dynamic time slot allocation strategy, the node calculates and confirms the busy time slot number occupied by itself before the start of the time frame period. When the busy time slot occupied by itself arrives, the node selects a certain idle time slot for reservation according to the service queue capacity, inserts the reserved idle time slot number and the priority of the to-be-sent service into the busy time slot to-be-sent data frame and completes the broadcast transmission. (2) Monitor the data information sent by other nodes and read the reservation information in the data frame. If the idle time slot number reserved by the node is the same as that of its own node, evaluate whether the two nodes have the same one-hop neighbor node according to LSDB. If so, it is considered that the two nodes occupying the idle time slot at the same time will cause signal interference, and determine the ownership of the idle time slot according to the service priority; if not, it is assumed that the two nodes successfully occupy the time slot at the same time. (3) Before the start of the next time frame period, the node needs to reset the reserved time slot numbers of each node stored in itself to 0 to ensure that the reservation information is not overwritten by the reservation information of the previous time frame period when forwarding the reservation information in multiple hops.

[0053] 3) The specific method of node access strategy is as follows: the new node outside the network initiates the new node access authentication process by sending a network access application message. The network access authentication adopts two-way authentication, the purpose of which is to mutually determine whether the other party is a legitimate node. When the node in the network receives the network access application message sent by the application node, it initiates the security authentication process with the application node.

[0054] When a legitimate node is initialized, it obtains the initial network access authentication key shared within the cluster.

[0055] When the new node monitors the routing signaling of the node in the network, it maintains its own LSDB and NSDB, and sends the network access authentication information DATA_NET_IN to the current node. The network access authentication information includes the network access encryption request, the new node IP address (updated according to the subnet IP to be applied for entry) and the new node location information;

[0056] When a node in the network receives a network access request, it uses the initial network access authentication key to enter the encryption algorithm module to generate encrypted data and send it to the new node;

[0057] After receiving the encrypted data, the new node correctly identifies the encrypted data and replies with the decrypted confirmation information;

[0058] After the node in the network receives the confirmation information carrying the decrypted data and compares it correctly, the security authentication is completed. The node in the network updates its own LSDB and NSDB and broadcasts the NSA routing signaling to other nodes in the network in the next time frame. When the new node receives the NSA routing signaling in the network and detects its own location information in the information, it is assumed that the network has been successfully joined. After the node already in the network receives the NSA signaling and a new node joins, the time slot allocation is readjusted in the next time frame.

Claims

1. A dynamic inter-satellite networking communication strategy, characterized in that include: Establish a five-layer protocol stack suitable for spacecraft collaborative networking scenarios, provide a transport layer transmission strategy based on the improved TCP / IP standard protocol, provide a wireless network layer routing strategy based on the improved OSPF, and provide a wireless link layer dynamic time slot allocation access control strategy.

2. The intersatellite dynamic networking communication strategy as claimed in claim 1, characterized in that The five-layer protocol stack suitable for spacecraft collaborative networking scenarios divides the protocol stack layers into application layer, transport layer, wireless network layer, wireless link layer and physical layer in sequence based on the general OSI seven-layer model.

3. The inter-satellite dynamic networking communication strategy according to any one of claims 1 or 2, characterized in that: In the improved transport layer transmission strategy based on the TCP / IP standard protocol, the transport layer reads and splits the data source packet transmitted from the application layer and then encapsulates it.

4. The inter-satellite dynamic networking communication strategy as claimed in any one of claims 3, characterized in that: The implementation of the TSC-TCP / IP strategy mainly consists of three processes: data transmission process, reception confirmation process and connection termination process. Each process requires the sender and the receiver to complete it together.

5. The intersatellite dynamic networking communication strategy as claimed in claim 4, characterized in that During the data transmission stage, the source node will encapsulate the received data into segmented messages suitable for transmission and send them to the destination node. When the destination node receives the segment, it will send an ACK confirmation message. When the source node receives it, it will send the next segment information. If no confirmation message is received, it means that the destination node has not received the previous segment, then it will resend the previous segment and wait for confirmation. This mechanism is used to ensure reliable connection and error retransmission.

6. The intersatellite dynamic networking communication strategy as claimed in claim 5, characterized in that In the connection termination phase, a two-way handshake process needs to be completed. The sending node sends a message to the receiving node to mark the end of the transmission, indicating that the data has been sent, and waits for the receiving node to send an ACK confirmation message. At this point, both the sending node and the receiving node confirm that the transmission is completed.

7. The inter-satellite dynamic networking communication strategy according to any one of claims 1 to 6, characterized in that The improved wireless network layer routing strategy based on OSPF is aimed at highly dynamic aircraft topology networks. It adopts a routing protocol improved based on the OSPF protocol to establish a fast-converging routing table, including link status information and network topology information, to provide guidance for forwarding low-speed services and narrow-beam antenna pointing of high-speed networks.

8. The inter-satellite dynamic networking communication strategy according to claim 7, characterized in that: The specific method is as follows: 1) Routing establishment: After the routing protocol is started, each node periodically broadcasts Hello packets to find neighboring nodes. After receiving the Hello packets, the nodes reply with Hello messages to confirm two-way communication and establish neighbor relationships. 2) Link state information synchronization: After establishing a neighbor relationship, the two nodes exchange link state tables in the network. The link state table contains the neighbor information table of all nodes in the network currently recorded by the sending node. Through the interaction of the link state tables of each node in the network, the link information table stored in each node quickly converges, and finally forms a link state database containing complete link state information of the network; 3) Calculate the route; after the link state database is synchronized, the nodes in the network have the same understanding of the network structure, and each node uses the Dijkstra algorithm to independently calculate the shortest path from the source node to the destination node based on the link state database information; 4) Route recovery: When a node fails or a topology change causes the original path to be interrupted, and the faulty node information in the node link state database has not been updated within a few time frame periods, the node is judged to be faulty, the node quickly updates the neighbor relationship, deletes the path related to the faulty node, and adaptively finds the best route under the current topology to complete route recovery; 5) Network topology information maintenance: Each node periodically broadcasts a node location information table, which contains the location coordinates of all nodes in the network currently recorded by the sending node. Through the interaction of the node location information tables of each node in the network, according to the dynamic time slot allocation strategy, the network topology information tables stored in each node quickly converge after several broadcast cycles, and finally form a network topology database containing complete network topology information.

9. The inter-satellite dynamic networking communication strategy according to any one of claims 1 to 8, characterized in that The dynamic time slot allocation access control strategy includes a dynamic time slot allocation strategy, an idle time slot reservation strategy and a node access strategy.

10. The inter-satellite dynamic networking communication strategy according to claim 9, characterized in that: During the time slot allocation process, the network within the cluster is divided into levels according to the star topology, and the network nodes occupy the time slots in the order from the outer layer to the center and then from the center to the outer layer.

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