Satellite network ground switching method, device and system

Abstract

The invention provides a satellite network ground switching method, device and system. A satellite network ground switching method can be used for network switching when satellites in the same orbit enter and exit from the same target area, the virtual IP and the MAC serve as unique identifications of the target area, and for the satellites entering and exiting from the same target area, network state information of the satellites is synchronized through control signals. And enabling the satellite to disable or start the identity label of the target area to perform network switching of the satellite. According to the satellite network ground switching method provided by the invention, when the two satellites carry out service switching on the same target area, the same identity label is adopted for communication, the virtual identity of the target area can be decoupled from the physical satellite, and the virtual IP and the virtual MAC are consistent before and after satellite communication switching, so that the communication efficiency is improved. The network state information of the ground gateway and the terminal does not need to be refreshed, and compared with an existing satellite network ground switching method, the communication time can be shortened, and the communication efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of satellite communication technology, in particular to a satellite network-to-ground switching method, a satellite network-to-ground switching device and a satellite network-to-ground switching system. BACKGROUND

[0002] In a low-orbit satellite internet system, due to the high-speed movement of satellites, the network communication link between ground users and satellites needs to be frequently switched. In the implementation of the current satellite-to-ground communication technology, a static ARP technology is often used, that is, a ground station pre-stores the MAC and ARP table entries of multiple satellites. This technical solution will cause the invalidation of TCP connection and other states, and the route table re-learning will take a long time, resulting in communication interruption and affecting user experience. SUMMARY

[0003] The purpose of the present application is to provide a satellite network-to-ground switching method, a satellite network-to-ground switching device and a satellite network-to-ground switching system to solve the problems existing in the prior art.

[0004] To achieve the above purpose, the present application provides the following solutions: The first aspect of the present application provides a satellite network-to-ground switching method for network switching of at least two satellites when entering or leaving the same target area, the method comprising: synchronizing the network state information of a first satellite preparing to leave the target area to a second satellite preparing to enter the target area, so that the first satellite and the second satellite generate their respective first signals, and the network state information at least includes the identity of the target area, and the first signal is used to indicate that the network state information synchronization has been completed; receiving the first signal from the satellite in the orbit, and the satellite in the orbit at least includes the first satellite and the second satellite, and the received first signal at least comes from the first satellite and the second satellite; sending a second signal to the first satellite when the first satellite leaves the target area, and the second signal makes the first satellite disable the identity of the target area; sending a third signal to the second satellite when the second satellite enters the target area, and the third signal makes the second satellite enable the identity of the target area; Wherein, the identity of the target area includes a virtual IP, a virtual MAC address and a virtual Locator address, and the network state information of the first satellite is stored on the on-board router of the first satellite, and after synchronization, it is also stored on the on-board router of the second satellite.

[0005] In some embodiments, the network state information further includes at least one of the following information: The network session information, network forwarding table information, or link and protocol status information of the first satellite.

[0006] In some embodiments, receiving a first signal from a satellite in orbit includes: Within a preset time range, the system receives the first signal from all satellites in the orbit, or receives the first signal from some satellites in the orbit, wherein all satellites or some satellites include at least satellite X and satellite Y, excluding the first satellite and the second satellite, and X and Y are numerical identifiers of the satellites. The method further includes: A second signal is sent to the Xth satellite, which causes the Xth satellite to disable the identity identifier of the target area where the Xth satellite is located; A third signal is sent to the Y-th satellite, which causes the Y-th satellite to activate the identity identifier of the target area that the Y-th satellite is preparing to enter; Among them, the target area where satellite X is located and the target area that satellite Y is preparing to enter are the same area.

[0007] In some embodiments, synchronizing the network status information of the first satellite preparing to leave the target area to the second satellite preparing to enter the target area includes: The network status information of the first satellite is synchronized point-to-point through the laser inter-satellite link established between the first and second satellites; Alternatively, the network status information of the first satellite may be transmitted to the second satellite via the network controller; Alternatively, the network status information of the first satellite can be transmitted to the second satellite via a database, wherein the database is written by the first satellite before leaving the target area and then read by the second satellite before entering the target area.

[0008] In some embodiments, the second signal causes the first satellite to disable the identity of the target area, including: After the first satellite receives the second signal, the following configuration is performed on the ground-reaching equipment inside the first satellite: The first satellite disables the virtual IP, virtual MAC, and virtual Locator address of the target area on its internal ground-reaching equipment, thereby stopping the first satellite from broadcasting and responding with the identity of the target area.

[0009] In some embodiments, the third signal causes the second satellite to enable the identification of the target area, including: After the second satellite receives the third signal, the following configuration is performed on the second satellite's internal ground-reaching equipment, enabling the second satellite to broadcast and respond in the identity of the target area: Configure the virtual IP address as the primary or secondary IP address of the internal ground-to-air device of the second satellite; Configure the virtual MAC address as the MAC address of the internal ground-to-air device of the second satellite; The virtual Locator address is declared in the routing protocol as the reachability identifier of the second satellite in the network.

[0010] In some embodiments, the method further includes: After the first satellite leaves the target area, a fourth signal is sent to the first satellite, which causes the first satellite to clear the network information status of the first satellite stored on the first satellite.

[0011] A second aspect of this application provides a satellite network-to-ground switching device for network switching when at least two satellites enter or leave the same target area, the device comprising: The information synchronization control module is used to control the synchronization of the network status information of the first satellite preparing to leave the target area to the second satellite preparing to enter the target area, so that the first satellite and the second satellite respectively generate their own first signals, and the network status information includes at least the identity identifier of the target area; The first signal receiving module receives a first signal from a satellite in orbit, wherein the satellite in orbit includes at least the first satellite and the second satellite, and the received first signal comes from at least the first satellite and the second satellite. The second signal transmitting module sends a second signal to the first satellite after the first satellite leaves the target area. The second signal causes the first satellite to disable the identity identifier of the target area. After the second satellite enters the target area, it sends a third signal to the second satellite. The third signal causes the second satellite to enable the identity identifier of the target area. The identity identifier of the target area includes a virtual IP, a virtual MAC address, and a virtual Locator address. The network status information of the first satellite is stored on the satellite's onboard router and, after synchronization, is also stored on the satellite's onboard router.

[0012] A third aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements any of the above-described satellite network-to-ground handover methods.

[0013] A fourth aspect of this application provides a satellite network-to-ground handover system, the system comprising at least: The aforementioned satellite network to ground switching device; The first satellite and the second satellite are in orbit in the target area and are preparing to leave the target area, and the second satellite is in orbit in the target area and is preparing to enter the target area. The inter-satellite network status information is synchronized based on the control signal of the satellite network to ground switching device, and the first signal is sent to the satellite network to ground switching device respectively. An internal ground-to-ground device is used to enable the identification of the target area by the first satellite to disable the identification of the target area based on a second signal received by the first satellite or a third signal received by the second satellite.

[0014] The satellite network handover method provided by this invention assigns a unique virtual IP address, virtual MAC address, and virtual Locator address to each target area as its network identity. When any satellite enters the area, it uses the same virtual IP and virtual MAC, using the target area's identity as the identity of the communication satellite serving the current area. Therefore, the satellite network handover method provided in this application decouples the virtual identity of the target area from the physical satellite. When two satellites handover services to the same target area, they use the same identity. Since the virtual IP and virtual MAC remain consistent before and after the satellite communication handover, the network status information of the ground gateway and terminal does not need to be refreshed. Compared with traditional satellite network handover methods, this can shorten communication time and improve communication efficiency. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic flowchart of a satellite network to ground handover method according to an embodiment of this application; Figure 2 This is a schematic diagram of the satellite network-to-ground switching device according to an embodiment of this application; Figure 3 This is a schematic diagram illustrating the network status changes of the ground access equipment and the onboard router during satellite network handover to the ground, as provided in this application.

[0017] Reference numerals: 1000. Satellite network to ground switching device; 1001. Information Synchronization Control Module; 1002. First signal receiving module; 1003. Second signal transmission module; 1100, bus; 1200, Processor; 1300, Memory; 1400. Other circuits. Detailed Implementation

[0018] Various embodiments and features of this application are described herein with reference to the accompanying drawings.

[0019] It should be understood that various modifications can be made to the embodiments described herein. Therefore, the above description should not be considered as limiting, but merely as an example of embodiments. Other modifications within the scope and spirit of this application will be apparent to those skilled in the art.

[0020] The accompanying drawings, which are included in and form part of this specification, illustrate embodiments of the present application and, together with the general description of the present application given above and the detailed description of the embodiments given below, serve to explain the principles of the present application.

[0021] These and other features of this application will become apparent from the following description of preferred forms of embodiments given as non-limiting examples, with reference to the accompanying drawings.

[0022] It should also be understood that although this application has been described with reference to some specific examples, those skilled in the art can certainly implement many other equivalent forms of this application.

[0023] Figure 1 A schematic flowchart of a satellite network to ground handover method according to one embodiment of this application is shown, as follows: Figure 1 As shown, a method for network switching when at least two satellites enter or leave the same target area includes: S101, synchronizing the network status information of a first satellite preparing to leave the target area to a second satellite preparing to enter the target area, so that the first and second satellites generate their respective first signals, the network status information including at least the identity identifier of the target area, and the first signal indicating that the network status information synchronization has been completed; S102, receiving the first signal from a satellite in orbit, the satellites in orbit including at least the first and second satellites, the received first signal coming from at least the first and second satellites; S103, after the first satellite leaves the target area, sending a second signal to the first satellite, the second signal causing the first satellite to disable the identity identifier of the target area; S104, after the second satellite enters the target area, sending a third signal to the second satellite, the third signal causing the second satellite to enable the identity identifier of the target area; wherein, the identity identifier of the target area includes a virtual IP, a virtual MAC address, and a virtual Locator address, the network status information of the first satellite is stored on the onboard router of the first satellite, and after synchronization, it is also stored on the onboard router of the second satellite.

[0024] First, the relevant technical background, terminology, and preset conditions of this invention will be explained.

[0025] While a satellite is in orbit, its communication network can dynamically cover different physical spaces. For a given physical space, different satellites in the same orbit will take turns providing services. When two different satellites appear alternately in the same area, it is necessary to switch the satellite communication network.

[0026] Based on satellite orbital parameters and coverage, the entire globe can be used as a service area, or a specific region can be used as a service area. The globe or a specific service area can be divided into multiple fixed geographic logical regions, and each geographic logical region is called a target region.

[0027] The division of service areas can be achieved through a network controller, which can be a ground control center or multiple distributed controllers. The network controller can divide the service area into several target regions based on satellite orbit parameters and coverage.

[0028] For satellite routers on the same orbit, their passage over a certain area is often fixed. Therefore, a unique virtual IP address, virtual MAC address, and virtual Locator address are assigned to the target area as the network identity of that target area.

[0029] Suppose multiple satellites are operating in a certain orbit, and satellite A and satellite B simultaneously enter and exit a specific target area at a certain time. In order to achieve successful communication with the Earth, satellite A and satellite B need to switch networks. For ease of understanding, the above steps are explained below in this scenario.

[0030] In step S101 above, each satellite in orbit, including the first satellite A and the second satellite B, needs its own unique identifier. This identifier distinguishes the satellites and enables them to communicate with the Earth. Since each satellite operates dynamically, it will dynamically cover different target areas. Therefore, by associating the identifier of a target area with a satellite currently operating in that target area, the satellite operating in that target area can communicate using the identifier of that target area. Because network communication generates a series of network status information, such as session information, it is necessary to synchronize the relevant network status information to ensure smooth communication between the first satellite A and the second satellite B after network switching. Specifically, this can be achieved by sending synchronization control signals to the first satellite A and the second satellite B respectively, causing them to begin synchronizing their network status information. After synchronization is complete, the first satellite A and the second satellite B need to generate a first signal indicating "synchronization complete" to facilitate subsequent network switching control.

[0031] In step S102 above, since multiple satellites can operate in the orbit, when a satellite in the orbit emits a first signal, the first signal emitted by each satellite in the orbit is received. Each satellite includes at least the first satellite A and the second satellite B. At this time, the received first signal comes from at least the first satellite A and the second satellite B.

[0032] In step S103 above, after the first satellite A leaves the target area, it will no longer be a communication satellite for the target area, and therefore needs to cease providing service to that target area. A "disable identity" signal is sent to the first satellite A as a second signal, which then causes the first satellite to stop using the identity of the target area.

[0033] In step S104 above, after the second satellite B enters the target area, it will serve as the communication satellite for that target area, thus requiring the activation of services for that area. A "activate identification" signal is sent as a third signal to the second satellite B, causing it to activate the identification for the target area.

[0034] The first satellite A can obtain the virtual network identity triplet (virtual IP, virtual MAC, virtual Locator) for the target area corresponding to the network controller, or it can obtain it from the previous satellite that is about to leave the target area via an inter-satellite link when it is about to enter the target area.

[0035] The satellite network handover method provided in this application assigns a unique virtual IP address, virtual MAC address, and virtual Locator address to each target area as its network identity. When any satellite enters the area, it uses the same virtual IP and virtual MAC, using the target area's identity as the identity of the communication satellite serving the current area. Therefore, the satellite network handover method provided in this application decouples the virtual identity of the target area from the physical satellite. When two satellites handover services to the same target area, they use the same identity. Since the virtual IP and virtual MAC remain consistent before and after the satellite communication handover, the network status information of the ground gateway and terminal does not need to be refreshed. Compared with traditional satellite network handover methods, this can shorten communication time and improve communication efficiency. In some embodiments, the network status information also includes at least one of the following: network session information of the first satellite, network forwarding table information, or link and protocol status information.

[0036] To make it easier to understand, let's continue with the above scenario.

[0037] During the communication service provided by Satellite A in the target area, numerous application network sessions will be generated. When Satellite B enters the target area, in order to maintain the normal operation of these sessions, Satellite A will synchronize the status of currently active network sessions with the virtual IP address as the endpoint to Satellite B. The network session status may include TCP connection sequence numbers, window sizes, MSS, timestamps, etc.; UDP "pseudo-connection" status; IPsec Security Association (SA) status, etc.

[0038] The network status information synchronized from the first satellite to the second satellite may also include network forwarding table information. The first satellite A can synchronize routing table entries, neighbor relationship tables (such as BGP / OSPF neighbor states), ARP / ND cache tables, etc., maintained in the current target area to the second satellite B.

[0039] Network status information synchronized from the first satellite to the second satellite can also include link and protocol status. For example, the first satellite A can synchronize QoS policy status, traffic statistics, and billing session status to the second satellite B.

[0040] The satellite network handover method provided in this application synchronizes session information to the receiving satellite via the handover satellite, enabling the receiving satellite to seamlessly take over the existing data stream from the handover satellite. Therefore, it ensures that the ARP table, routing table, TCP connection, and other states of the ground equipment remain valid and communication is uninterrupted without the ground equipment needing to be aware of the satellite handover. This method offers advantages such as transparency to the ground network, low handover latency, high reliability, and easy scalability, making it suitable for dynamic handover scenarios in multi-satellite networks.

[0041] In some embodiments, receiving a first signal from a satellite in orbit includes: receiving a first signal from all satellites in orbit, or receiving a first signal from some satellites in orbit, within a preset time range, wherein all satellites or some satellites include at least satellite X and satellite Y, excluding the first satellite and the second satellite, where X and Y are numerical identifiers of the satellites; the method further includes: sending a second signal to satellite X, the second signal causing satellite X to disable the identification of the target area where satellite X is located; sending a third signal to satellite Y, the third signal causing satellite Y to enable the identification of the target area that satellite Y is about to enter; wherein the target area where satellite X is located and the target area that satellite Y is about to enter are the same area. For ease of understanding, the above scenario will continue to be explained.

[0042] Since multiple satellites typically operate within a single orbit—meaning that besides satellite A and satellite B, other satellites may be performing network handover—the handover process must consider the network handover scenarios of multiple satellites. To address this issue, a starting handover satellite for a given orbit is predefined, denoted as satellite number 1. Subsequent satellites are sequentially numbered and labeled, such as from 2 to N, where N represents the satellite's identification number. Starting with satellite number 1, upon receiving its first signal indicating "synchronization complete," the system checks for the first signals from each of the other satellites. When all satellites within an orbit are confirmed to be ready for handover, second and third signals are sent to satellites entering and exiting the target area, respectively disabling and enabling the target area identification for each satellite, thus initiating the handover operation. The first signal can be emitted by the laser router of each satellite.

[0043] The completion time of synchronization information between satellites may vary. To ensure uninterrupted service, a time window can be set to ensure that network switching between satellites does not exceed this time window. For example, the time window can be set to 1 minute. When the first "synchronization complete" signal is received from the satellite initiating the switch, the timer starts. If the controller has not received the first signal from all satellites in a certain orbit, it waits for 1 minute. After the timeout, the network switch is immediately initiated. Second and third signals are sent to satellites entering and leaving each target area, respectively disabling and enabling the target area identification of each satellite, and then the switch operation is performed. For satellites in the same orbit, the access timeout error during network switching should not exceed 1 minute.

[0044] For precise time control, PTP or BeiDou / GPS systems can be used.

[0045] It should be noted that the above time window can be set to any time.

[0046] The satellite network-to-ground handover method provided in this application achieves extremely low handover latency, shortening the handover window to the millisecond level, making it more efficient than traditional satellite network-to-ground handover schemes. In some embodiments, synchronizing the network status information of a first satellite preparing to leave the target area to a second satellite preparing to enter the target area includes: point-to-point synchronization of the network status information of the first satellite through a laser inter-satellite link established between the first and second satellites; or transmitting the network status information of the first satellite to the second satellite through a network controller; or transmitting the network status information of the first satellite to the second satellite through a database, wherein the database is written by the first satellite before leaving the target area and then read by the second satellite before entering the target area.

[0047] To make it easier to understand, let's continue with the above scenario.

[0048] Synchronizing the network status information of the first satellite preparing to leave the target area to the second satellite preparing to enter the target area can be achieved in any of the following ways: Method 1: Establish a communication link between the first satellite A and the second satellite B. When the first and second satellites need to synchronize information, the network status information of the first satellite is synchronized point-to-point through the laser inter-satellite link established between them. Specifically, in the aforementioned scenario, after the first satellite A and the second satellite B receive the synchronization control signal, they synchronize point-to-point through the laser inter-satellite link established between them. Method 2: Use the network controller as a transmission relay station to control the first satellite A and the second satellite B. The network status information of the first satellite A is transmitted to the second satellite B through the network controller. Specifically, in the aforementioned scenario, after the first satellite A and the second satellite B receive the synchronization control signal, the first satellite A sends its network status information to the network controller, which receives the network status information and forwards it to the second satellite B. Method 3: Establish a database that allows for information sharing among the satellites. When data sharing of network status information is required between the first satellite A and the second satellite B, the first satellite A first writes its network status information into the database, and then the second satellite B retrieves the network status information by reading the database. Specifically, the database is written by the first satellite A before leaving the target area, and then read by the second satellite B before entering the target area. In the aforementioned scenario, specifically, after the first satellite A and the second satellite B receive the synchronization control signal, the first satellite A writes the network status information into the database, and then the second satellite B reads the network status information from the database.

[0049] The satellite network handover method provided in this application enables the receiving satellite to obtain network status information related to the handover satellite through various means before entering the area, with flexible synchronization methods and high synchronization efficiency. In some embodiments, the database has the following carrier methods and / or distribution structures: the database carrier method includes satellite-based or ground-based; the database distribution structure includes distributed storage or centralized storage.

[0050] For database distribution structures, either a single-machine or distributed mode can be selected based on the database's scale. For example, OceanBase's integrated architecture can be adopted, allowing performance comparable to mainstream single-machine databases when deployed on a single machine, and supporting seamless scaling to distributed clusters. This reduces the complexity of transitioning from single-machine to distributed systems, making it suitable for scenarios with business growth.

[0051] The database can be deployed on a satellite or on ground equipment that communicates with the satellite. Ground equipment can be, for example, a ground gateway station.

[0052] Furthermore, this invention does not limit the type of database; it can be a relational database or a non-relational database. Relational databases can be, for example, MySQL, PostgreSQL, Oracle, or Microsoft SQL Server, while non-relational databases can be, for example, Redis or MongoDB.

[0053] The satellite network handover method provided in this application can be either spaceborne or terrestrial, and the distribution structure can be either distributed or centralized, allowing for flexible configuration as needed. This ensures the flexibility, stability, and reliability of data sharing between handover and access satellites when using database synchronization. In some embodiments, the second signal causing the first satellite to disable the target area's identity identifier includes: upon receiving the second signal, the first satellite performs the following configuration on its internal ground-reaching device: disabling the target area's virtual IP, virtual MAC, and virtual Locator address on the first satellite's internal ground-reaching device, thereby stopping the first satellite from broadcasting and responding with the target area's identity identifier.

[0054] In satellite-to-ground communication, the satellite first undergoes signal conversion through ground access equipment. The satellite then communicates with the ground network via this equipment, which can be a gateway station. The gateway station, acting as a data exchange hub between the satellite and the ground network, is primarily responsible for routing, forwarding, and protocol conversion of satellite communication service data. Its core functions include: connecting satellite signals to backbone networks such as the terrestrial internet and telecommunications networks to achieve cross-network data transmission; dynamically controlling data flow through a session management module to support service continuity when users move across satellites (e.g., IP address management, tunneling technology); and significantly improving communication quality in areas without terrestrial network coverage, such as polar regions and offshore areas (e.g., Starlink's gateway station achieves high-speed backhaul via Ka / Ku band antennas).

[0055] When the first satellite A receives the second signal of "disable identity", the following configuration can be performed on the internal ground-to-ground device of the first satellite A, such as a router (or an exit of the router; the term "internal ground-to-ground device" in this application has the same meaning and will not be described in detail here): disable the virtual IP, virtual MAC, and virtual Locator address of the target area, thereby stopping the first satellite A from broadcasting and responding with the identity of the target area. In some embodiments, the third signal causes the second satellite to enable the identity of the target area, including: when the second satellite receives the third signal, the following configuration is performed on the internal ground-to-ground device of the second satellite, thereby causing the second satellite to broadcast and respond with the identity of the target area: configure the virtual IP address as the primary or secondary IP of the internal ground-to-ground device of the second satellite; configure the virtual MAC address as the MAC address of the internal ground-to-ground device of the second satellite; and advertise the virtual Locator address as the reachability identifier of the second satellite in the routing protocol.

[0056] To facilitate understanding, let's continue with the above scenario. The internal ground-to-ground device of the second satellite B can be, for example, a router. When the second satellite B receives the third signal of "Enable Identity," its router performs the following configurations, enabling the second satellite B to broadcast and respond with the identity of the target area: The virtual IP address is configured as the primary or secondary IP address of the second satellite's internal ground-to-ground device; the virtual MAC address is configured as the MAC address of the second satellite's internal ground-to-ground device; and the virtual Locator address is advertised in the routing protocol as the reachability identifier of the second satellite in the network. Furthermore, this virtual MAC address can also be advertised via proxy ARP / NDP.

[0057] The satellite network handover method provided in this application disables and enables the satellite's identity in the current target area through the satellite's internal ground-to-ground equipment, such as a router. For satellites in the same orbit, while ensuring that the access timeout error during network handover does not exceed the preset time window, only one satellite is allowed to use the identity of a certain target area within a certain time. This ensures the atomicity and consistency of the handover action, avoids address conflicts caused by "two satellites in the same area", and coordinates the precise handover by the network controller.

[0058] In some embodiments, the method further includes: after the first satellite leaves the target area, sending a fourth signal to the first satellite, the fourth signal causing the first satellite to clear the network information status of the first satellite stored on the first satellite.

[0059] To make it easier to understand, we will continue to explain using the above scenarios.

[0060] Once Satellite A leaves the target area, it no longer serves network communication in that area and therefore no longer needs to store the current network status information. A fourth signal indicating "clear network status information" can be sent to Satellite A. This fourth signal causes Satellite A to clear the network information status stored on it, preparing it for entry into the next possible new target area.

[0061] The satellite network handover method provided in this application enables the handover satellite to promptly clear invalid information after leaving the area, thereby releasing storage resources and improving the effective utilization rate of storage resources.

[0062] Figure 3 This is a schematic diagram illustrating the network status changes of the ground access equipment and the onboard router during satellite network handover to the ground, as provided in this application.

[0063] like Figure 3 As shown, Gateway1 and Gateway2 are ground access devices, such as ground gateway stations, while LaserRouter1-LaserRouter7 are satellite-borne routers deployed on satellites, such as laser routers.

[0064] When the onboard router connected to Gateway1 switches from LaserRouter-2 to LaserRouter-1, LaserRouter-1 uses the virtual IP, virtual MAC, and virtual locator of LaserRouter-2, while synchronizing the relevant TCP sessions and routing tables. When the onboard router connected to Gateway2 switches from LaserRouter-7 to LaserRouter-6, LaserRouter-6 uses the virtual IP, virtual MAC, and virtual locator of LaserRouter-7, while synchronizing the relevant TCP sessions and routing tables.

[0065] At this point, for traffic forwarding during the handover process, only the very short delay of link disconnection and reconnection is perceived. For the forwarding path, the device path changes from Gateway1, LaserRouter-2, LaserRouter-5, LaserRouter-6, LaserRouter-7, Gateway2 to Gateway1, LaserRouter-1, LaserRouter-4, LaserRouter-5, LaserRouter-6, Gateway2. Because the virtual IPs, MAC addresses, and locators of LaserRouter-2, LaserRouter-5, LaserRouter-6, and LaserRouter-7 are synchronized to the previous satellite in the same orbit (i.e., the onboard router of the previous satellite), namely LaserRouter-1, LaserRouter-4, LaserRouter-5, and LaserRouter-6.

[0066] Throughout the process, the MAC address corresponding to the target IP address remains the same virtual MAC address in the ARP tables of both the terminal and the gateway, requiring no refresh of the ARP table / ND cache. Since the network core route points to the virtual Locator address or virtual IP address of the area, this address remains unchanged, and the route does not need modification. The session's four-tuple (source IP, source port, destination IP, destination port) remains unchanged, and because the session state (sequence number, etc.) is synchronized, data packets being transmitted via the old satellite (first satellite A) can be correctly received and processed by the new satellite (second satellite B), and the connection is not reset.

[0067] As can be seen, the information of each router remains unchanged before and after the network switch. The ground station does not need to relearn the routing table, and there will be no communication interruption or TCP connection failure due to the time required for relearning routes. Therefore, the entire forwarding table remains unchanged, achieving seamless transmission on the ground and improving the user experience.

[0068] Figure 2 A schematic diagram of a satellite network-to-ground switching device according to one embodiment of this application is shown, as follows: Figure 2As shown, a network switching device for at least two satellites entering and leaving the same target area includes: an information synchronization control module 1001, used to control the synchronization of network status information of a first satellite preparing to leave the target area to a second satellite preparing to enter the target area, so that the first and second satellites respectively generate their own first signals, the network status information including at least the identity identifier of the target area, and the first signal indicating that the network status information synchronization has been completed; a first signal receiving module 1002, used to receive the first signal from satellites in orbit, the satellites in orbit including at least the first and second satellites, and the received first signal coming from at least the first and second satellites; and a second signal sending module 1003, used to send a second signal to the first satellite after the first satellite leaves the target area, the second signal causing the first satellite to disable the identity identifier of the target area, and to send a third signal to the second satellite after the second satellite enters the target area, the third signal causing the second satellite to enable the identity identifier of the target area; wherein, the identity identifier of the target area includes a virtual IP, a virtual MAC address and a virtual Locator address, the network status information of the first satellite is stored on the onboard router of the first satellite, and after synchronization is also stored on the onboard router of the second satellite.

[0069] To facilitate understanding, the satellite network-to-ground switching device will be further explained.

[0070] The satellite network-to-ground switching device is used to control the switching of the satellite network to ground. The device can be deployed on ground or space communication equipment to establish network connections with the satellite and the satellite's internal ground-to-ground equipment, respectively. The device includes at least an information synchronization control module 1001, a first signal receiving module 1002, and a second signal transmitting module 1003.

[0071] It should be noted that before using this device, the target area division has been determined, and each target area has a unique identifier. The division of service areas can be achieved through a network controller, which can be a ground control center or multiple distributed controllers. The network controller can divide the service area into several target areas based on satellite orbit parameters and coverage. When using this device, the identifier of the target area will be dynamically used as the identifier of the satellite serving that target area, enabling the satellite to communicate using the identifier of that target area. The identifier of the target area includes a virtual IP address, a virtual MAC address, and a virtual Locator address.

[0072] The modules are explained below in light of the aforementioned scenarios.

[0073] The information synchronization control module 1001 can send synchronization control signals to the first satellite A and the second satellite B, controlling the synchronization of the network status information of the first satellite A (which is preparing to leave the target area) to the second satellite B (which is preparing to enter the target area). After synchronization is completed, the first satellite A and the second satellite B each need to generate a first signal indicating "synchronization completed," so that the information synchronization control module 1001 can receive the first signal and perform subsequent network switching based on the first signal. The network status information includes at least the identity identifier of the target area. Before synchronization, the network status information of the first satellite is stored on the onboard router of the first satellite, and after synchronization, it is also stored on the onboard router of the second satellite.

[0074] Since multiple satellites can operate in the orbit, when a satellite in the orbit emits a first signal, the first signal receiving module 1002 receives the first signals emitted by each satellite in the orbit, including at least the first satellite A and the second satellite B. At this time, the received first signal comes from at least the first satellite A and the second satellite B.

[0075] Once the first satellite A leaves the target area, it will no longer be a communication satellite for that area, and therefore service to that area needs to be discontinued. The second signal transmission module 1003 sends a "disable identity" signal to the first satellite A, which then causes the first satellite to stop using the identity of the target area.

[0076] The satellite network-to-ground handover device provided in this application decouples the virtual identity of the target area from the physical satellite. When two satellites switch services to the same target area, the same identity identifier is used. Since the virtual IP and virtual MAC are consistent before and after the satellite communication handover, the network status information of the ground gateway and terminal does not need to be refreshed. Compared with traditional satellite network-to-ground handover methods, this can shorten communication time and improve communication efficiency.

[0077] It should be noted that the implementation details of each module of the satellite network-to-ground handover device provided in this application correspond one-to-one with the steps of the satellite network-to-ground handover method provided in this application, and will not be repeated here. According to at least one embodiment of the satellite network-to-ground handover system of this application, the system includes at least: any of the above-mentioned satellite network-to-ground handover devices, a first satellite, a second satellite, and internal ground-reaching devices for the first / second satellite. The first satellite is in orbit operating in the target area and preparing to leave the target area, while the second satellite is in orbit operating in and preparing to enter the target area. Inter-satellite network status information is synchronized based on the synchronization control signal of the satellite network-to-ground handover device, and a first signal is sent to the satellite network-to-ground handover device respectively. The internal ground-reaching devices are used to disable the target area's identity identifier on the first satellite and enable the target area's identity identifier on the second satellite based on the second signal received by the first satellite and the third signal received by the second satellite.

[0078] The satellite network-to-ground handover system provided in this application decouples network service logic from the physical satellite platform, facilitating satellite upgrades, replacements, and flexible constellation expansion, and offering advantages in architectural decoupling and flexibility.

[0079] This application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, it implements the methods described above. The methods described in the above embodiments can be implemented wholly or partially by software, hardware, firmware, or any combination thereof. If implemented in software, the functionality can be stored as one or more instructions or code on or transmitted over the computer-readable medium. The computer-readable medium can include computer storage media and communication media, and can also include any medium that can transfer a computer program from one place to another. The storage medium can be any target medium accessible by a computer.

[0080] In one possible implementation, a computer-readable medium may include RAM, ROM, compact disc read-only memory (CD-ROM) or other optical disc storage, disk storage or other magnetic storage devices, or any other medium targeted to carry or to store the required program code in the form of instructions or data structures, and accessible by a computer. Furthermore, any connection is appropriately referred to as a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. As used herein, disks and optical discs include optical discs, laser discs, optical discs, Digital Versatile Discs (DVDs), floppy disks, and Blu-ray discs, where disks typically reproduce data magnetically, while optical discs optically reproduce data using lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0081] Figure 2An example diagram of an apparatus employing a hardware implementation of a processing system is shown. The apparatus may include corresponding modules that perform one or more steps of the flowchart described above. Therefore, each or more steps of the flowchart may be performed by a corresponding module, and the apparatus may include one or more of these modules. A module may be one or more hardware modules specifically configured to perform the corresponding step, or implemented by a processor configured to perform the corresponding step, or stored in a computer-readable medium for implementation by a processor, or implemented through some combination thereof.

[0082] This hardware architecture can be implemented using a bus architecture. The bus architecture can include any number of interconnect buses and bridges, depending on the specific application and overall design constraints of the hardware. Bus 1100 connects various circuits, including one or more processors 1200, memory 1300, and / or hardware modules. Bus 1100 can also connect various other circuits 1400, such as peripherals, voltage regulators, power management circuits, external antennas, etc.

[0083] Bus 1100 can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Component Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of representation, this diagram uses only one connection line, but this does not imply that there is only one bus or one type of bus.

[0084] The processor 1200 described above can be a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof. The general-purpose processor can be a microprocessor or any conventional processor, etc.

[0085] Any process or method described in the flowcharts or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which the embodiments of this application pertain. The processor performs the various methods and processes described above. For example, the method embodiments of this application can be implemented as software programs tangibly contained in a machine-readable medium, such as memory. In some embodiments, part or all of the software program may be loaded and / or installed via memory and / or a communication interface. When the software program is loaded into memory and executed by the processor, one or more steps of the methods described above can be performed. Alternatively, in other embodiments, the processor may be configured to perform one of the methods described above by any other suitable means (e.g., by means of firmware).

[0086] The logic and / or steps represented in the flowchart or otherwise described herein may be specifically implemented in any readable storage medium for use by, or in conjunction with, an instruction execution system, apparatus or device (such as a computer-based system, a processor-included system or other system that can fetch and execute instructions from, an instruction execution system, apparatus or device).

[0087] For the purposes of this specification, a "readable storage medium" can be any means capable of containing, storing, communicating, propagating, or transmitting a program for use by or in conjunction with an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of readable storage media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and portable read-only memory (CDROM). Furthermore, a readable storage medium can even be paper or other suitable media on which a program can be printed, since a program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in memory.

[0088] It should be understood that various parts of this application can be implemented in hardware, software, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0089] Those skilled in the art will understand that all or part of the steps of the methods described above can be implemented by a program instructing related hardware, and the program can be stored in a readable storage medium. When executed, the program includes one or a combination of the steps of the method implementation.

[0090] Furthermore, the functional units in the various embodiments of this application can be integrated into a single processing module, or each unit can exist physically separately, or two or more units can be integrated into a single module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a readable storage medium. The storage medium can be a read-only memory, a disk, or an optical disk, etc.

[0091] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0092] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0093] Those skilled in the art should understand that the above embodiments are merely for illustrative purposes and are not intended to limit the scope of this application. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of this application.

Claims

1. A method for satellite network handover to ground, for network handover of same-orbit satellites when entering or leaving a same target area, characterized in that, The method comprises: synchronizing network state information of a first satellite preparing to leave a target area to a second satellite preparing to enter the target area, so that the first satellite and the second satellite generate respective first signals, the network state information at least comprising an identity of the target area, the first signals being used to indicate that network state information synchronization has been completed; receiving first signals from satellites in orbit, the satellites in orbit at least comprising the first satellite and the second satellite, the received first signals at least being from the first satellite and the second satellite; after the first satellite leaves the target area, sending a second signal to the first satellite, the second signal causing the first satellite to disable the identity of the target area; after the second satellite enters the target area, sending a third signal to the second satellite, the third signal causing the second satellite to enable the identity of the target area; wherein the identity of the target area comprises a virtual IP, a virtual MAC address and a virtual Locator address, the network state information of the first satellite being stored on a satellite-borne router of the first satellite and, after synchronization, on a satellite-borne router of the second satellite.

2. The method of claim 1, wherein, The network state information further comprises at least one of the following: network session information, network forwarding table information or link and protocol state information of the first satellite.

3. The method of claim 1, wherein, The receiving first signals from satellites in orbit comprises: within a preset time range, receiving first signals from all satellites in orbit or receiving first signals from part of the satellites in orbit, wherein the all satellites or the part of the satellites at least comprise an Xth satellite and a Yth satellite in addition to the first satellite and the second satellite, X and Y being numerical identifiers of the satellites; The method further comprises: sending a second signal to the Xth satellite, the second signal causing the Xth satellite to disable the identity of a target area in which the Xth satellite is located; sending a third signal to the Yth satellite, the third signal causing the Yth satellite to enable the identity of a target area into which the Yth satellite is preparing to enter; wherein the target area in which the Xth satellite is located and the target area into which the Yth satellite is preparing to enter are the same area.

4. The method of claim 1, wherein, The synchronizing network state information of the first satellite preparing to leave the target area to the second satellite preparing to enter the target area comprises: point-to-point synchronization of the network state information of the first satellite through a laser inter-satellite link established between the first satellite and the second satellite; or transmission of the network state information of the first satellite to the second satellite through a network controller; or transmission of the network state information of the first satellite to the second satellite through a database, wherein the database is written into by the first satellite before leaving the target area and read from by the second satellite before entering the target area.

5. The method of claim 1, wherein, The second signal causing the first satellite to disable the identity of the target area comprises: after the first satellite receives the second signal, performing the following configuration on an internal ground device of the first satellite: disable the virtual IP, virtual MAC and virtual Locator addresses of the target region on the internal ground equipment of the first satellite, so as to stop the first satellite from broadcasting and responding as the target region.

6. The method of claim 1, wherein, The third signal enables the second satellite to identify the target region, including: When the second satellite receives the third signal, the following configurations are applied on the internal ground equipment of the second satellite, so as to enable the second satellite to broadcast and respond as the target region: The virtual IP address is configured as the primary IP or secondary IP of the internal ground equipment of the second satellite; The virtual MAC address is configured as the MAC address of the internal ground equipment of the second satellite; The virtual Locator address is announced in the routing protocol as the reachability identifier of the second satellite in the network.

7. The method of claim 1, wherein, The method further includes: When the first satellite leaves the target region, a fourth signal is sent to the first satellite, which enables the first satellite to clear the network information state of the first satellite saved on the first satellite.

8. A satellite network handover apparatus for network handover of at least two satellites when entering or leaving the same target area, characterized in that, The device includes: An information synchronization control module for synchronizing the network state information of the first satellite preparing to leave the target region to the second satellite preparing to enter the target region, so that the first satellite and the second satellite generate respective first signals, and the network state information at least includes the identity of the target region; A first signal receiving module for receiving the first signal from the satellite in orbit, which at least includes the first satellite and the second satellite, and the received first signal at least comes from the first satellite and the second satellite; A second signal sending module for sending a second signal to the first satellite when the first satellite leaves the target region, which enables the first satellite to disable the identity of the target region, and sending a third signal to the second satellite when the second satellite enters the target region, which enables the second satellite to enable the identity of the target region; Wherein, the identity of the target region includes virtual IP, virtual MAC address and virtual Locator address, and the network state information of the first satellite is stored on the satellite router of the first satellite, and after synchronization, it is also stored on the satellite router of the second satellite.

9. A computer readable storage medium, the computer readable storage medium stores a computer program, the computer program is executed by a processor to implement the satellite network ground switching method of any one of claims 1 to 7.

10. A satellite network-to-ground handover system, characterized by, The system at least includes: The satellite network ground switching device of claim 8; The first satellite and the second satellite, the first satellite is in orbit in the target region and is preparing to leave the target region, the second satellite is in orbit in the target region and is preparing to enter the target region, and the inter-satellite network state information is synchronized based on the control signal of the satellite network ground switching device, and the first signal is sent to the satellite network ground switching device respectively; The internal-to-ground device is configured to, based on the second signal received by the first satellite / the third signal received by the second satellite, cause the first satellite to disable the identity of the target area / the second satellite to enable the identity of the target area.

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