Communication satellite handover method

Abstract

Disclosed in the present application is a communication satellite handover method. The method comprises: performing grouping processing on a plurality of user equipments to obtain a grouping result; and for each group, when a handover condition is met, executing communication satellite handover for the group, wherein the communication satellite handover for the group comprises: a group head device performing handover from a source satellite to a destination satellite by means of RACH handover, and in response to the trigger of the group head device, group member devices performing handover from the source satellite to the destination satellite by means of RACH-less handover, which group member devices are other user equipments in the group other than the group head device. The present application solves the technical problems in the prior art of network congestion, handover interruption and handover delay increases caused by great signaling overheads during communication satellite handover.

Description

Method for switching communication satellites

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on November 28, 2023, with application number 202311609037X and invention name “Method for Switching Communication Satellites”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of mobile communications, and in particular to a method for switching communication satellites. Background Art

[0003] To increase mobile communications coverage, mobile communications have expanded from traditional terrestrial networks to aerospace networks. 3GPP began researching non-terrestrial networks in Rel-16 and entered the Wi-Fi (Wi-Fi) phase in Rel-17, discussing the standardization of specific technologies.

[0004] With the rapid growth of network technology and the rapid increase in user and service volume, low-orbit satellites are increasingly facing dense user scenarios. When the number of ground users reaches a certain level, a large number of users will simultaneously send handover request messages to the destination satellite. For satellite communication systems with limited resources, the simultaneous occurrence of handover management services will cause resource competition and conflicts, generating significant signaling overhead. Furthermore, frequent handovers generate a large number of request messages, which can easily lead to network congestion, handover interruptions, and increased handover latency.

[0005] Currently, no effective solution has been proposed to the problem that the above-mentioned related technologies have large signaling overhead during the switching of communication satellites, resulting in network congestion, switching interruption, and increased switching delay.

[0006] Summary of the Invention

[0007] An embodiment of the present application provides a method for switching communication satellites to at least solve the technical problem in related technologies that large signaling overhead leads to network congestion, switching interruption, and increased switching delay during the switching of communication satellites.

[0008] According to one aspect of an embodiment of the present application, a method for switching a communication satellite is provided, comprising:

[0009] A plurality of user devices are grouped to obtain a grouping result, wherein the plurality of user devices are located in a coverage area of ​​a source satellite and are in communication connection with the source satellite, and the grouping result includes at least one group, and each group includes at least one group head device; for each group, when a switching condition is met, switching of the communication satellite of the group is performed; wherein the switching of the communication satellite of the group includes: the group head device is switched from the source satellite to the destination satellite according to the RACH switching mode, and the group member devices are switched from the source satellite to the destination satellite according to the RACH-less switching mode in response to the triggering of the group head device, wherein the group member devices are other user devices in the group except the group head device.

[0010] Optionally, multiple user devices are grouped to obtain grouping results including: grouping the multiple user devices according to their geographical locations to obtain at least one group, wherein the user devices in each group in the at least one group are located in the same cell; for each group in the at least one group, determining a target user device from the user devices in the current group as the group head device corresponding to the current group.

[0011] Optionally, for each group in at least one group, determining the target user device from the user devices in the current group includes one of the following: determining the target user device based on the average distance between each user device in the current group and other user devices in the current group; determining the target user device based on the distance between each user device in the current group and the regional center corresponding to the current group, wherein the regional center is the geographic center of the locations of all user devices in the current group; determining the target user device based on the received signal strength of each user device in the current group.

[0012] Optionally, the network side includes a source satellite, a destination satellite and a gateway station, and executing the switching of the communication satellite of the group includes: the source satellite receives a first switching request message sent by the group head device, and sends a second switching request message to the gateway station based on the first switching request message, wherein the first switching request message includes: the measurement identification parameter and measurement result parameter corresponding to the group head device, the second switching request message includes: the identifier of the destination satellite, the identifier of the group, the identifier of the group head device and the identifier of the group member device, the measurement identification parameter is determined by the identifier of the group head device and the identifier of the group member device, and the measurement result parameter is also used to determine the measurement result of the group member device; the gateway station sends a third switching request message to the destination satellite based on the second switching request message, receives the first switching response message returned by the destination satellite, and returns the second switching response message to the source satellite, wherein the third switching request message is used to characterize the group The switching requirement of the first device, the first switching response message includes: the access information corresponding to the group head device and the uplink authorization information corresponding to the group member device, the second switching response message includes at least the uplink authorization information, the access information is determined by the current load of the destination satellite and the number of group member devices corresponding to the group head device, and the uplink authorization information is used to support the group member devices corresponding to the group head device to perform communication satellite switching in accordance with the RACH-less switching method; the source satellite sends a third switching response message to the group head device and a fourth switching response message to the group member devices according to the second switching response message, wherein the fourth switching response message includes at least the uplink authorization information, the third switching response message is used for the group head device to switch from the source satellite to the destination satellite in accordance with the RACH switching method, and the uplink authorization information is used for the group member devices to switch from the source satellite to the destination satellite in accordance with the RACH-less switching method.

[0013] Optionally, the switching conditions include: the difference between the second signal strength and the first signal strength is greater than a first threshold, and / or there are more than a preset number of group member devices in the group that meet the following conditions: the difference between the fourth signal strength and the third signal strength is greater than the second threshold; wherein the first signal strength is the signal strength of the satellite signal received by the group head device in the group from the source satellite, the second signal strength is the signal strength of the satellite signal received by the group head device in the group from the destination satellite to be switched, the third signal strength is the signal strength of the satellite signal received by the group member device from the source satellite, and the fourth signal strength is the signal strength of the satellite signal received by the group member device from the destination satellite.

[0014] Optionally, the above-mentioned method for switching communication satellites also includes: in response to at least two groups having simultaneous communication satellite switching needs, performing priority analysis on at least two group head devices corresponding to the at least two groups to obtain priority sorting results; according to the priority sorting results, controlling at least two group head devices to switch from the source satellite to the destination satellite in sequence according to the RACH switching method.

[0015] According to another aspect of an embodiment of the present application, a method for switching communication satellites is also provided, which is applied to a group head device of a group, where the group is obtained by grouping multiple user devices, and the multiple user devices are located in the coverage area of ​​a source satellite and are communicatively connected to the source satellite. When the switching conditions are met, the method includes: the group head device switches from the source satellite to the destination satellite in accordance with the RACH switching method, and triggers the group member devices to switch from the source satellite to the destination satellite in accordance with the RACH-less switching method, wherein the group member devices are other user devices in the group except the group head device.

[0016] Optionally, the above-mentioned method for switching communication satellites also includes: when the switching conditions are met, the group head device sends a first switching request message to the source satellite, and the first switching request message is used to request to switch the communication satellite from the source satellite to the destination satellite; the switching conditions include: the difference between the second signal strength and the first signal strength is greater than the first threshold, and / or, there are more than a preset number of group member devices in the group that meet the following conditions: the difference between the fourth signal strength and the third signal strength is greater than the second threshold; wherein the first signal strength is the signal strength of the satellite signal received by the group head device in the group from the source satellite, the second signal strength is the signal strength of the satellite signal received by the group head device in the group from the destination satellite to be switched, the third signal strength is the signal strength of the satellite signal received by the group member device from the source satellite, and the fourth signal strength is the signal strength of the satellite signal received by the group member device from the destination satellite.

[0017] Optionally, triggering a group member device to switch from a source satellite to a destination satellite in a RACH-less switching manner includes: sending a group member switching command message to the group member device to assist the group member device in switching from the source satellite to the destination satellite in a RACH-less switching manner based on uplink authorization information and the group member switching command message, wherein the information carried in the group member switching command message includes at least synchronization deviation information, and the synchronization deviation information is used to determine the clock synchronization deviation between the source satellite and the destination satellite, and the uplink authorization information is sent by the source satellite to the group member device.

[0018] Optionally, switching from a source satellite to a destination satellite in accordance with the RACH switching method includes: sending a first switching request message to the source satellite through a random access channel, wherein the first switching request message is used to request switching to a communication connection with the destination satellite, and the first switching request message includes: a measurement identification parameter and a measurement result parameter corresponding to the group head device, the measurement identification parameter is determined by the identification of the group head device and the identification of the group member device, and the measurement result parameter is also used to determine the measurement result of the group member device; receiving a third switching response message returned by the source satellite, wherein the third switching response message is used to instruct the group head device to switch to a communication connection with the destination satellite; and switching from the source satellite to the destination satellite in accordance with the third switching response message.

[0019] Optionally, the above-mentioned method for switching communication satellites also includes: obtaining a first moment, a second moment, a third moment and a fourth moment, wherein the first moment is the moment when the source satellite sends a first synchronization signal, the second moment is the moment when the group head device receives the first synchronization signal, the third moment is the moment when the destination satellite sends a second synchronization signal, and the fourth moment is the moment when the group head device receives the second synchronization signal; calculating the first propagation time of the first synchronization signal based on the first moment and the second moment, and calculating the second propagation time of the second synchronization signal based on the third moment and the fourth moment; and using the first propagation time and the second propagation time to calculate the synchronization deviation information.

[0020] According to another aspect of an embodiment of the present application, a method for switching communication satellites is also provided, which is applied to group member devices of a group, where the group is obtained by grouping multiple user devices, and the group member devices are other user devices in the group except the group head device. The multiple user devices are located in the coverage area of ​​the source satellite and are communicatively connected to the source satellite. The method includes: in response to a trigger of the group head device, switching from the source satellite to the destination satellite in a RACH-less switching manner, wherein the group head device switches from the source satellite to the destination satellite in a RACH switching manner.

[0021] Optionally, the above-mentioned method for switching communication satellites also includes: when the switching conditions are met, the group member device sends a group member switching request message to the group head device, and the group member switching request is used to request to switch the communication satellite from the source satellite to the destination satellite; the switching conditions include: the difference between the fourth signal strength and the third signal strength is greater than the second threshold; wherein the third signal strength is the signal strength of the satellite signal received by the group member device from the source satellite, and the fourth signal strength is the signal strength of the satellite signal received by the group member device from the destination satellite.

[0022] Optionally, responding to the trigger of the group head device to switch from the source satellite to the destination satellite in a RACH-less switching manner includes: receiving a group member switching command message sent by the group head device, wherein the information carried in the group member switching command message includes at least: synchronization deviation information, and the synchronization deviation information is used to determine the clock synchronization deviation between the source satellite and the destination satellite; based on the uplink authorization information and the synchronization deviation information, switching from the source satellite to the destination satellite in a RACH-less switching manner, wherein the uplink authorization information is sent by the source satellite to the group member devices; wherein the group member switching command message is generated by a switching response message returned by the source satellite received by the group head device, and the switching response message is a response message to the switching request message sent by the group head device to the source satellite via a random access channel, and the switching response message is used to instruct the group head device to switch to a communication connection with the destination satellite.

[0023] According to another aspect of an embodiment of the present application, a device for switching a communication satellite is provided, including:

[0024] The grouping module is configured to perform grouping processing on multiple user devices to obtain grouping results, wherein the multiple user devices are located in the coverage area of ​​the source satellite and are in communication connection with the source satellite, and the grouping results include at least one group, and each group includes at least one group head device; the execution module is configured to execute the switching of the communication satellite of the group for each group when the switching conditions are met; wherein the switching of the communication satellite of the group includes: the group head device switches from the source satellite to the destination satellite according to the RACH switching method, and the group member devices switch from the source satellite to the destination satellite according to the RACH-less switching method in response to the triggering of the group head device, wherein the group member devices are other user devices in the group except the group head device.

[0025] Optionally, the above-mentioned grouping module is also configured to: group multiple user devices according to their geographical locations to obtain at least one group, wherein the user devices in each group in at least one group are located in the same cell; for each group in at least one group, determine the target user device from the user devices in the current group as the group head device corresponding to the current group.

[0026] Optionally, the above-mentioned grouping module is further configured to: determine the target user device based on the average distance between each user device in the current group and other user devices in the current group; determine the target user device based on the distance between each user device in the current group and the regional center corresponding to the current group, wherein the regional center is the geographic center of the locations of all user devices in the current group; determine the target user device based on the received signal strength of each user device in the current group.

[0027] Optionally, the network side includes a source satellite, a destination satellite and a gateway station, and the above-mentioned execution module is further configured to: the source satellite receives a first switching request message sent by the group head device, and sends a second switching request message to the gateway station based on the first switching request message, wherein the first switching request message includes: the measurement identification parameter and measurement result parameter corresponding to the group head device, and the second switching request message includes: the identifier of the destination satellite, the identifier of the group, the identifier of the group head device and the identifier of the group member device, the measurement identification parameter is determined by the identifier of the group head device and the identifier of the group member device, and the measurement result parameter is also used to determine the measurement result of the group member device; the gateway station sends a third switching request message to the destination satellite based on the second switching request message, receives the first switching response message returned by the destination satellite, and returns the second switching response message to the source satellite, wherein the third switching request message is used to characterize the group head device. The first switching response message includes: the access information corresponding to the group head device and the uplink authorization information corresponding to the group member device; the second switching response message includes at least the uplink authorization information; the access information is determined by the current load of the destination satellite and the number of group member devices corresponding to the group head device; the uplink authorization information is used to support the group member devices corresponding to the group head device to perform communication satellite switching in accordance with the RACH-less switching method; the source satellite sends a third switching response message to the group head device and a fourth switching response message to the group member devices according to the second switching response message, wherein the fourth switching response message includes at least the uplink authorization information; the third switching response message is used for the group head device to switch from the source satellite to the destination satellite in accordance with the RACH switching method, and the uplink authorization information is used for the group member devices to switch from the source satellite to the destination satellite in accordance with the RACH-less switching method.

[0028] Optionally, the switching conditions include: the difference between the second signal strength and the first signal strength is greater than a first threshold, and / or there are more than a preset number of group member devices in the group that meet the following conditions: the difference between the fourth signal strength and the third signal strength is greater than the second threshold; wherein the first signal strength is the signal strength of the satellite signal received by the group head device in the group from the source satellite, the second signal strength is the signal strength of the satellite signal received by the group head device in the group from the destination satellite to be switched, the third signal strength is the signal strength of the satellite signal received by the group member device from the source satellite, and the fourth signal strength is the signal strength of the satellite signal received by the group member device from the destination satellite.

[0029] Optionally, the above-mentioned device for switching communication satellites also includes: a sorting module, which is configured to perform priority analysis on at least two group head devices corresponding to at least two groups in response to the simultaneous existence of communication satellite switching needs in at least two groups, and obtain a priority sorting result; according to the priority sorting result, control the at least two group head devices to switch from the source satellite to the destination satellite in sequence according to the RACH switching method.

[0030] According to another aspect of an embodiment of the present application, a communication network device is provided, including: a memory storing an executable program; and a processor for running the program, wherein when the program runs, any one of the aforementioned methods for switching communication satellites is executed.

[0031] According to another aspect of an embodiment of the present application, a computer-readable storage medium is provided, the storage medium including a stored program, wherein when the program is running, the device where the storage medium is located is controlled to execute any of the aforementioned methods for switching communication satellites.

[0032] In an embodiment of the present application, a plurality of user devices are first grouped to obtain a grouping result, wherein the plurality of user devices are located in the coverage area of ​​a source satellite and are in communication connection with the source satellite, and the grouping result includes at least one group, and each group includes at least one group head device. Finally, for each group, when the switching conditions are met, the switching of the communication satellite of the group is executed, wherein the switching of the communication satellite of the group includes: the group head device switches from the source satellite to the destination satellite in accordance with the RACH switching method, and the group member devices switch from the source satellite to the destination satellite in accordance with the RACH-less switching method in response to the triggering of the group head device, wherein the group member devices are other user devices in the group except the group head device.

[0033] It is easy to understand that the above-mentioned method provided by the present application, after grouping multiple user devices to obtain a group head device and a group user device, executes the group head device to switch from the source satellite to the destination satellite according to the RACH switching method and the group member devices to switch according to the RACH-less switching method when the switching conditions are met, thereby reducing the signaling overhead in the process of switching communication satellites, improving network fluency and communication satellite switching efficiency, and reducing switching delay, thereby solving the technical problem of related technologies in the process of switching communication satellites, which is that the signaling overhead is large, resulting in network congestion, switching interruption, and increased switching delay. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0035] FIG1 is a flow chart of a method for switching communication satellites according to an embodiment of the present application;

[0036] FIG2 is a schematic diagram of grouping during an optional switching communication satellite process according to an embodiment of the present application;

[0037] FIG3 is a schematic diagram of an optional process of switching communication satellites according to an embodiment of the present application;

[0038] FIG4 is a flowchart of an optional process of switching communication satellites according to an embodiment of the present application;

[0039] FIG5 is a flowchart of another optional process of switching communication satellites according to an embodiment of the present application;

[0040] FIG6 is a structural block diagram of an optional apparatus for switching communication satellites according to an embodiment of the present application;

[0041] FIG7 is a structural block diagram of another optional apparatus for switching communication satellites according to an embodiment of the present application. DETAILED DESCRIPTION

[0042] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0043] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in a sequence other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0044] In the process of describing the embodiments of the present application, some nouns or terms that appear are subject to the following interpretations:

[0045] Third Generation Partnership Project (3GPP): An international mobile communications standards organization whose mission is to develop global technical specifications for various wireless communication technologies (such as 2G, 3G, 4G, and 5G) and promote interoperability and compatibility between different operators and different devices. 3GPP communication standards may include, but are not limited to, Long-Term Evolution (LTE), Voice over LTE (VoLTE), and Narrowband Internet of Things (NB-IoT).

[0046] Non-Terrestrial Network (NTN): A communication network that does not rely on infrastructure on Earth but is built using non-terrestrial equipment such as satellites, airships, and drones.

[0047] Work Item (WI): In an international standards organization or association, a work item refers to an ongoing but unfinished research and discussion project on a specific topic.

[0048] Rel-16, Rel-17, and Rel-18: refer to the 16th, 17th, and 18th versions of technical specifications released by 3GPP, respectively. Each version has different features, extended functions, and performance targets.

[0049] User Equipment (UE) generally refers to terminal equipment in a mobile communication system, which can be, but is not limited to, a mobile phone or a tablet.

[0050] 5G NR (5G New Radio): A wireless communication system based on the new 5G air interface and protocol architecture. This system offers advantages such as higher transmission speeds, lower latency, and greater network capacity than existing LTE and WiFi.

[0051] Random Access Response (RAR) message: used to respond to a random access request (RACH attempt) initiated by the UE.

[0052] TA (Timing Advance): In satellite communication systems, due to the distance between the UE and the satellite, it is necessary to adjust the transmission timing to make the signal arrival time more synchronized. TA is the parameter used to calculate this time offset. After receiving a TA request from the base station or satellite, the UE makes corresponding adjustments based on information such as its own position and motion status.

[0053] Uplink grant (UL grant): refers to an authorization message sent by a base station or satellite to a terminal device, notifying it that it can start uploading data and informing it of parameter information such as the required resources, transmission format and power.

[0054] Low Earth Orbit (LEO) satellite network: A wireless communication technology that uses small, low-altitude satellites operating in low-Earth orbit to achieve wide-area coverage and communication transmission through networking.

[0055] Physical Downlink Control Channel (PDCCH): An important physical channel in LTE networks, used to transmit control information (including but not limited to scheduling, power control, and uplink / downlink switching).

[0056] ServingCellConfigCommon: Parameters used to configure cell broadcast information, shared network resources, and other related settings in the LTE system.

[0057] DownlinkConfigCommon: Parameters used to configure downlink control information and resource allocation in the LTE system. The relevant settings include but are not limited to: downlink frequency configuration, initial downlink BWP, BCCH configuration, and PCCH configuration.

[0058] Bandwidth Part (BWP): is defined as a group of consecutive resource blocks used to transmit data or control information.

[0059] BCCH configuration (Broadcast Control Channel): A basic configuration in mobile communication systems used to broadcast control information.

[0060] Paging Control Channel (PCCH): A channel used for paging and allocating frequency resources in a mobile communication system.

[0061] ReconfigurationWithSync: A distributed system configuration management technology that can dynamically modify and update configuration information while the system is running and ensure that these modifications and updates can be synchronized to all nodes.

[0062] t304 in ReconfigurationWithSync: used to indicate the duration of the UE's random access to the relevant SpCell timer.

[0063] SpCell timer: used to control the time of switching operations between different cells (SpCells).

[0064] SMTC (Short Maximum Time-to-Trigger for Cell Change): is a measurement configuration parameter in LTE that limits the duration and period of UE measurements on specific resources.

[0065] Radio Resource Control (RRC) configuration information: refers to the control signaling in the radio access network, used to reconfigure and update the communication parameters between the UE and the base station. The communication parameters may include but are not limited to: frequency, bandwidth, power, and scheduling algorithm.

[0066] UplinkConfigCommon: used to store configuration options related to network connection communication, including but not limited to: protocol type, IP address, port number, and authentication information.

[0067] Single Sideband Communication (SSB): A modulation method in which only one sideband and carrier are transmitted, while the other sideband is suppressed, thereby reducing power consumption and improving transmission distance and quality.

[0068] Channel State Information Reference Signal (CSI-RS): A technical means for obtaining relevant information such as frequency response and noise between user equipment and base stations in wireless communication systems.

[0069] Service Set Identifier (SSID): An identifier used to distinguish different wireless networks.

[0070] Dijkstra's algorithm: An algorithm for finding the shortest path in a weighted graph. It gradually expands the path by continuously selecting the node closest to the starting point that has not been visited. It uses a priority queue to quickly find the next node to visit. After the algorithm runs, each node will record the length of the shortest path from the starting point to the node and the nodes included in the path.

[0071] Based on the problem in the related art that large signaling overhead leads to network congestion, switching interruption, and increased switching delay during the switching process of communication satellites, according to an embodiment of the present application, a method embodiment of switching communication satellites is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that here.

[0072] FIG1 is a flow chart of a method for switching communication satellites according to an embodiment of the present application. As shown in FIG1 , the method includes the following steps:

[0073] Step S11, performing grouping processing on the plurality of user devices to obtain a grouping result, wherein the plurality of user devices are located in a coverage area of ​​a source satellite and are in communication connection with the source satellite, the grouping result includes at least one group, and each group includes at least one group head device;

[0074] The above-mentioned multiple user devices may be terminal devices that can interact with the network and exchange information. Usually, in the field of mobile communications, user devices may include but are not limited to: smartphones, tablets, and laptops. It can also be understood that in the 5G era, user devices may also include new intelligent devices (such as Internet of Things nodes), vehicle-mounted terminals, industrial controllers and other devices. It should also be noted here that the above-mentioned multiple user devices may be located in the same coverage area of ​​the source satellite, or they may be distributed in different coverage areas of the source satellite. The above-mentioned group head device can be used to schedule and manage other user devices in the group, and allocate resources to each user device in the group.

[0075] It should be noted that the above-mentioned grouping of user devices is performed based on group handover technology. Group handover is a handover mechanism in mobile communication networks that simultaneously switches a group of devices when a mobile device switches from one communication satellite (or base station) to another, thereby maintaining continuous communication between these devices.

[0076] In the optional solution provided in the present application, multiple devices are grouped to obtain grouping results. The specific method may be: according to the discrete degree of the geographical location of each user device, the multiple user devices are first divided into multiple groups, and then the average distance from each user device in the group to all other user devices is calculated, and the average distance corresponding to each user device is compared to determine the user device corresponding to the minimum average distance, so as to determine the user device corresponding to the minimum average distance as the group head device.

[0077] Step S12: For each group, when the switching conditions are met, the switching of the group's communication satellite is executed; wherein the switching of the group's communication satellite includes: the group head device switches from the source satellite to the destination satellite according to the RACH switching method, and the group member devices respond to the triggering of the group head device and switch from the source satellite to the destination satellite according to the RACH-less switching method, wherein the group member devices are other user devices in the group except the group head device.

[0078] The above-mentioned switching conditions may include: the difference between the second signal strength and the first signal strength is greater than the first threshold, and / or there are more than a preset number of group member devices in the group that meet the following conditions: the difference between the fourth signal strength and the third signal strength is greater than the second threshold; wherein, the first signal strength is the signal strength of the satellite signal received by the group head device in the group from the source satellite, the second signal strength is the signal strength of the satellite signal received by the group head device in the group from the destination satellite to be switched, the third signal strength is the signal strength of the satellite signal received by the group member device from the source satellite, and the fourth signal strength is the signal strength of the satellite signal received by the group member device from the destination satellite.

[0079] The RACH (Random Access Channel) handover method described above can be used in mobile communication systems. When a user moves from the service coverage area of ​​a current communication satellite (or base station) to the service coverage area of ​​another communication satellite (or base station), the user needs to use the random access channel to connect to the new base station and complete the handover. However, the RACH handover process introduces additional latency and wireless resource contention, which may lead to communication interruption or quality degradation during the handover process.

[0080] The RACH-less handover method described above can be a handover mechanism in wireless communications, used to achieve interference-free handovers in mobile communication systems. By pre-configuring and allocating system resources, mobile devices can avoid performing the random access procedure (RACH) that relies on the Random Access Channel (RACH) when handing over to a communication satellite (or base station), instead directly using pre-allocated resources for communication. This reduces handover latency, increases handover success rates, and improves communication quality and user experience.

[0081] In an embodiment of the present application, a plurality of user devices are first grouped to obtain a grouping result, wherein the plurality of user devices are located in the coverage area of ​​a source satellite and are in communication connection with the source satellite, and the grouping result includes at least one group, and each group includes at least one group head device. Finally, for each group, when the switching conditions are met, the switching of the communication satellite of the group is executed, wherein the switching of the communication satellite of the group includes: the group head device switches from the source satellite to the destination satellite in accordance with the RACH switching method, and the group member devices switch from the source satellite to the destination satellite in accordance with the RACH-less switching method in response to the triggering of the group head device, wherein the group member devices are other user devices in the group except the group head device.

[0082] It is easy to understand that the above-mentioned method provided by the present application, after grouping multiple user devices to obtain a group head device and a group user device, executes the group head device to switch from the source satellite to the destination satellite according to the RACH switching method and the group member devices to switch according to the RACH-less switching method when the switching conditions are met, thereby reducing the signaling overhead in the process of switching communication satellites, improving network fluency and communication satellite switching efficiency, and reducing switching delay, thereby solving the technical problem of related technologies in the process of switching communication satellites, which is that the signaling overhead is large, resulting in network congestion, switching interruption, and increased switching delay.

[0083] The above method of the above embodiment of the present application is further introduced below.

[0084] In an optional embodiment, in step S11, grouping is performed on multiple user equipments, and obtaining a grouping result includes:

[0085] Step S111, performing grouping processing on the plurality of user equipments to obtain a grouping result includes: grouping the plurality of user equipments according to their geographical locations to obtain at least one group, wherein the user equipments in each group of the at least one group are located in the same cell;

[0086] Step S112: For each of the at least one group, determine a target user equipment from the user equipments in the current group as a group head device corresponding to the current group.

[0087] In the technical solution provided in this application, it should be noted that due to the high-speed movement of low-orbit satellites, their coverage range will change rapidly on the surface of the earth, resulting in each low-orbit satellite only being able to provide service time for a few minutes. Therefore, each time a group switch is initiated, grouping is performed and a group head is selected.

[0088] In the above optional embodiment, the technical effect that can be achieved is: by grouping multiple user devices and selecting a group head device in each group, so that in the subsequent switching of communication satellites, the group head device sends a switching request message to the source satellite to reduce the number of request messages in the network, thereby solving the technical problem that all user devices send request messages to the source satellite at the same time, resulting in too many request messages in the network, network congestion and even switching interruption.

[0089] In an optional embodiment, in step S112, for each of the at least one group, determining the target user equipment from the user equipments in the current group includes one of the following:

[0090] Step S1121: determining a target user device based on the average distance between each user device in the current group and other user devices in the current group;

[0091] Step S1122: determining a target user device based on the distance between each user device in the current group and the regional center corresponding to the current group, where the regional center is the geographical center of the locations of all user devices in the current group;

[0092] Step S1123 : determining a target user equipment according to the received signal strength of each user equipment in the current group.

[0093] The method of steps S1121 to S1123 is further described below with reference to FIG. 2 .

[0094] FIG2 is a schematic diagram of an optional clustering process during a communication satellite switching process according to an embodiment of the present application. As shown in FIG2 , as an optional implementation, a geographic location clustering algorithm based on average distance is used to calculate the average distance between each user device in each group and all other user devices in the group, and the user device with the smallest average distance to all other user devices in the group is selected as the group leader device of the current group. It is understood that the signal strength received by the group leader device selected by the average distance-based geographic location clustering algorithm is close to the average received signal strength of all group member devices, and the communication distance between the group leader device and the group member devices is small.

[0095] As another optional implementation, a regional center-based geographic clustering algorithm is used to select the user device closest to the geographic center as the group leader. It is understood that the regional center-based geographic clustering algorithm is the most complex, and the group leader selected by this method receives a signal strength close to the average received signal strength of the group member devices.

[0096] As another optional implementation, a geolocation clustering algorithm based on received signal strength is used to select the user device with the strongest received signal strength as the group leader. It is understood that the group leader selected by the geolocation clustering algorithm based on received signal strength is close to the edge of the satellite coverage area, which can quickly determine the need for communication satellite handover. However, this method has the problem of a large difference in signal strength between the group leader and group member devices, and a large communication distance between the group leader and group member devices.

[0097] In the above optional embodiments, the technical effect that can be achieved is: the group head device and group member devices of the group can be quickly determined according to one of the multiple grouping algorithms, thereby improving the grouping efficiency, so that in the subsequent process, the group head device sends a switching request message to the source satellite to reduce the number of request messages in the network, and the selected group head device and other group member devices are switched from the source satellite to the destination satellite in different switching methods, thereby solving the technical problem of the related technology in the process of switching communication satellites, which is that the signaling overhead is large, resulting in network congestion, switching interruption, and increased switching delay.

[0098] In an optional embodiment, in step S12, the network side includes a source satellite, a destination satellite, and a gateway station, and performing switching of the communication satellites of the group includes:

[0099] Step S121: The source satellite receives a first handover request message sent by the group head device, and sends a second handover request message to the gateway based on the first handover request message, wherein the first handover request message includes: a measurement identification parameter and a measurement result parameter corresponding to the group head device; the second handover request message includes: an identifier of the destination satellite, an identifier of the group, an identifier of the group head device, and identifiers of group member devices; the measurement identification parameter is determined by the identifier of the group head device and the identifiers of the group member devices; and the measurement result parameter is further used to determine measurement results of the group member devices;

[0100] Step S122: The gateway sends a third handover request message to the destination satellite based on the second handover request message, receives a first handover response message returned by the destination satellite, and returns a second handover response message to the source satellite, wherein the third handover request message is used to represent the handover requirement of the group head device, the first handover response message includes: access information corresponding to the group head device and uplink authorization information corresponding to the group member devices, the second handover response message includes at least uplink authorization information, the access information is determined by the current load of the destination satellite and the number of group member devices corresponding to the group head device, and the uplink authorization information is used to support the group member devices corresponding to the group head device to perform communication satellite handover in accordance with the RACH-less handover mode;

[0101] In step S123, the source satellite sends a third switching response message to the group head device and a fourth switching response message to the group member devices based on the second switching response message, wherein the fourth switching response message includes at least uplink authorization information. The third switching response message is used for the group head device to switch from the source satellite to the destination satellite according to the RACH switching method, and the uplink authorization information is used for the group member devices to switch from the source satellite to the destination satellite according to the RACH-less switching method.

[0102] The gateway can be a device used to provide network connectivity and forward data during mobile communications. Furthermore, it can detect and address security risks during data transmission. The access information is used to determine whether the destination satellite accepts user equipment (including the group leader device and corresponding group user equipment) from being handed off to that satellite.

[0103] The above method will be further described below with reference to FIG3 and FIG4 .

[0104] Figure 3 is a schematic diagram of an optional switching communication satellite process according to an embodiment of the present application, and Figure 4 is a flow chart of an optional switching communication satellite process according to an embodiment of the present application. As shown in Figures 3 and 4, before switching the communication satellite, a geographic location clustering algorithm can be used to group multiple user devices to obtain multiple groups, and a group head device (group heads a, b, c as shown in Figure 3) is selected in each group. In addition, each group can also include one or more group user devices (group members 1 to 7 as shown in Figure 3).

[0105] Still as shown in Figures 3 and 4, the group leader device in a certain group (group leader b in Figure 3) determines whether the group needs to switch communication satellites based on the measured service signal strength (i.e., the signal strength of the source satellite A and the destination satellite B). Specifically, for example, group leader b measures the received signal power of the source satellite A to be P1 and the signal power of the destination satellite B to be P2. When group leader b detects that the difference between P2 and P1 is greater than the power switching threshold P th When the group determines that it needs to switch communication satellites, the group leader B then sends a handover request message (i.e., the first handover request message) to the source satellite A. Specifically, the measurement identifier parameter measID in the signaling corresponding to the first handover request message is added to the ID of the group member corresponding to the group leader B (group members 5 and 6 shown in Figure 3). The serving cell measurement result parameter measResultServCell (including the ID of the serving cell and its RSRP and RSRQ values) and the neighboring cell measurement result parameter measResultNeighCell (including the IDs of all neighboring cells and the RSRP and RSRQ values ​​corresponding to each neighboring cell) of the group leader B are used to represent the measurement result parameters of all group member devices corresponding to the group leader B (group members 5 and 6 shown in Figure 3).

[0106] Furthermore, source satellite A parses the first handover request message and encapsulates information such as the identity of destination satellite B, the identity of the group, and the identities of group member devices into a satellite message (i.e., the aforementioned second handover request message) and sends it to the gateway. The gateway then generates a handover request message (i.e., the aforementioned third handover request message) based on the satellite message and sends the handover request message to destination satellite B to notify destination satellite B to prepare corresponding communication resources.

[0107] Furthermore, the destination satellite B performs admission control based on its current load and the number of group member devices to determine whether to receive the user device. When the destination satellite B confirms the reception of the user device, it allocates corresponding wireless channel resources and access information to all user devices. Then, the destination satellite B generates a response message corresponding to the handover request message (i.e., the above-mentioned first handover response message) and sends it to the gateway station.

[0108] Furthermore, after receiving the response message of the switching request, the gateway confirms that the destination satellite B is ready for switching, and forwards the response message of the switching request (i.e., the above-mentioned second switching response message) to the source satellite A. The source satellite A parses the response message of the switching request and generates a group head switching command message (i.e., the above-mentioned third switching response message), and then sends the group head switching command message to the group head b, so that the group head b switches from the source satellite A to the destination satellite B in a RACH switching manner according to the group head switching command message. Then, when the switching of the group head b is completed, it sends a switching command message (i.e., the above-mentioned fourth switching response message) to the group members 5 and 6, so that the group member devices switch from the source satellite A to the destination satellite B in a RACH-less switching manner according to the fourth switching response message.

[0109] In the technical solution provided by this application, the uplink grant message (UL grant) represents dedicated wireless resource information required by group member devices. The source satellite can send the UL grant individually to each group user device within the group. If a group user device is unable to obtain a UL grant from the source satellite, the group user device can obtain the UL grant information by monitoring the PDCCH of the destination satellite. It is also understood that group member devices can obtain the UL grant information based on the fixed PDCCH physical channel preconfigured in the group member handover command, or they can obtain the UL grant information through a full-band search.

[0110] It should also be noted that, considering that some parameters in the RRC reconfiguration information sent by the source satellite to the user equipment in the same group are the same, such as DownlinkConfigCommon, UplinkConfigCommon, t304 and SMTC in ServingCellConfigCommon, after the source satellite sends the RRC reconfiguration message to the group head device, the group head device will group-send some of the same information in the RRC reconfiguration information to each group user device. It should be noted here that during the SMTC period, the UE will perform wireless link monitoring (or wireless resource management measurement) on the configured SSB or CSI-RS of the ephemeris table and other data of the destination satellite. It can also be understood that when both the group head device and the group member devices are equipped with wireless network cards, mutual communication between the group head device and the group member devices can be achieved by setting the same SSID information, the same channel information, etc.

[0111] It can also be understood that the communication network between the group leader device and group member devices has the following characteristics:

[0112] (1) In this network structure, since there is no fixed center, network nodes can be quickly organized and built. In addition, the information transmission method between the group leader device and group member devices can be set according to the actual scenario (such as single-hop communication method, multi-hop communication method);

[0113] (2) In this network, each network node can obtain its own location information, and each network node in the network can periodically broadcast messages and can also receive messages broadcast by neighboring nodes to obtain the location information of neighboring nodes. For neighboring nodes, different broadcast frequencies can be set to avoid mutual interference between nodes.

[0114] It should also be noted that the fields of the message broadcast by the neighbor node may be as shown in Table 1 below:

[0115] Table 1

[0116] When a node receives the message shown in Table 1 above from a neighbor node, it updates the source node identifier and the location information of the node (including the horizontal coordinate and the vertical coordinate of the node) to the neighbor table. The structure of the updated neighbor table can be shown in Table 2 below:

[0117] Table 2

[0118] It should be further explained that when the current node does not receive the message shown in Table 1 above from another node in the neighbor table within a period of time, it is determined that the other node has failed to work or has left the communication area of ​​the current node, and then the current node immediately removes the other node from the neighbor table.

[0119] Furthermore, when the group leader and group user devices communicate using multi-hop communication, a maximum number of hops from each node to the group leader can be set to ensure that each group user device receives the handover command message from the group leader within a short period of time. Furthermore, to control the algorithm's runtime, the Dijkstra algorithm can be used to solve the shortest path problem.

[0120] In the above optional embodiments, the technical effect that can be achieved is: the group head device can communicate with the group member devices through any one of a variety of communication methods to send group member switching command messages to the group member devices, thereby reducing the signaling overhead in the process of switching communication satellites and improving data transmission efficiency.

[0121] In an optional embodiment, the above-mentioned method for switching communication satellites further includes:

[0122] Step S131, in response to at least two groups having simultaneous communication satellite handover requirements, performing priority analysis on at least two group head devices corresponding to the at least two groups to obtain a priority ranking result;

[0123] Step S132: According to the priority sorting result, control at least two cluster head devices to switch from the source satellite to the destination satellite in sequence according to the RACH switching method.

[0124] In the technical solution provided by this application, for multiple groups within the coverage area of ​​the same satellite, after grouping and group leader selection, the priority of each group leader device can be calculated based on parameter information such as the signal strength of the destination satellite B measured by each group leader device, the number of group users, and the application category of each group user device. It can be understood that, generally, the priority of group user devices with application requirements such as voice and video is higher than the priority of group user devices with application requirements such as audio and image. Therefore, the priority of each group leader device can be calculated based on the hierarchical analysis method, and the priorities of all group leader devices within the coverage area of ​​the same satellite can be sorted. When multiple groups have switching requirements at the same time, the group with the group leader device with the higher priority is switched first. In addition, for other groups, it can be determined whether to switch their communication satellite from the source satellite to the destination satellite based on the traffic balancing constraint of the destination satellite.

[0125] In the above optional embodiment, the technical effect that can be achieved is: when the group head devices of multiple groups within the coverage area of ​​the same satellite send switching requests to the source satellite at the same time, the group head devices in each area are prioritized, so that when multiple group head devices send switching requests at the same time, the group head devices with higher priorities are switched first, so as to solve the problem of high signaling consumption caused by multiple group head devices switching communication satellites at the same time, and can also reduce switching delay, improve switching efficiency and success rate.

[0126] According to another aspect of an embodiment of the present application, a method for switching communication satellites is provided. The method is applied to a group head device of a group, where the group is obtained by grouping a plurality of user devices, and the plurality of user devices are located in a coverage area of ​​a source satellite and are in communication connection with the source satellite. When a switching condition is met, the method includes:

[0127] In step S21, the group head device switches from the source satellite to the destination satellite according to the RACH switching mode, and triggers group member devices to switch from the source satellite to the destination satellite according to the RACH-less switching mode, wherein the group member devices are other user devices in the group except the group head device.

[0128] In the technical solution provided by the present application, the above-mentioned switching conditions may include: the difference between the second signal strength and the first signal strength is greater than a first threshold, and / or there are more than a preset number of group member devices in the group that meet the following conditions: the difference between the fourth signal strength and the third signal strength is greater than a second threshold; wherein the first signal strength is the signal strength of the satellite signal received by the group head device in the group from the source satellite, the second signal strength is the signal strength of the satellite signal received by the group head device in the group from the destination satellite to be switched, the third signal strength is the signal strength of the satellite signal received by the group member devices from the source satellite, and the fourth signal strength is the signal strength of the satellite signal received by the group member devices from the destination satellite. When the switching conditions are met, the group head device sends a first switching request message to the source satellite, and the first switching request message can be used to request to switch the communication satellite from the source satellite to the destination satellite.

[0129] When the switching conditions are met, the group head device switches from the source satellite to the destination satellite according to the RACH switching method. The specific method may be: sending a first switching request message to the source satellite through a random access channel, wherein the first switching request message is used to request switching to a communication connection with the destination satellite, and the first switching request message includes: a measurement identification parameter and a measurement result parameter corresponding to the group head device, the measurement identification parameter is determined by the identification of the group head device and the identification of the group member device, and the measurement result parameter is also used to determine the measurement result of the group member device, and then, receiving a third switching response message returned by the source satellite, wherein the third switching response message is used to instruct the group head device to switch to a communication connection with the destination satellite, and finally, switching from the source satellite to the destination satellite according to the third switching response message.

[0130] And, when the switching conditions are met, the group member device is triggered to switch from the source satellite to the destination satellite in a RACH-less switching manner. The specific method may be: sending a group member switching command message to the group member device to assist the group member device to switch from the source satellite to the destination satellite in a RACH-less switching manner based on the uplink authorization information and the group member switching command message, wherein the information carried in the group member switching command message includes at least synchronization deviation information, and the synchronization deviation information is used to determine the clock synchronization deviation between the source satellite and the destination satellite. The uplink authorization information is sent by the source satellite to the group member device.

[0131] It should be noted that the above-mentioned synchronization deviation information can be used to characterize the difference in communication time between the source satellite and the destination satellite to the user equipment. Specifically, when the synchronization deviation information is not zero, it can characterize that the communication time between the source satellite and the destination satellite to the user equipment is different.

[0132] Still as shown in Figures 3 and 4, while the source satellite A sends a group head switching command message to the group head b, the source satellite A sends a group member-specific signaling message to the group member devices 5 and 6 in the same group as the group head b. Furthermore, after the group head b switches from the source satellite to the destination satellite according to the RACH switching method based on the group head switching command message, the group head b sends a group member switching command message to the group member devices 5 and 6. The group member switching command message includes at least a synchronization deviation message for determining the clock synchronization deviation between the source satellite and the destination satellite.

[0133] In an optional embodiment, the above-mentioned method for switching communication satellites further includes:

[0134] Step S231: Acquire a first time, a second time, a third time, and a fourth time, wherein the first time is the time when the source satellite sends a first synchronization signal, the second time is the time when the cluster head device receives the first synchronization signal, the third time is the time when the destination satellite sends a second synchronization signal, and the fourth time is the time when the cluster head device receives the second synchronization signal;

[0135] Step S232: Calculate a first propagation time of the first synchronization signal according to the first moment and the second moment, and calculate a second propagation time of the second synchronization signal according to the third moment and the fourth moment;

[0136] Step S233: Calculate synchronization deviation information using the first propagation time and the second propagation time.

[0137] Still as shown in Figures 3 and 4, after the group member devices 5 and 6 receive the group member switching command message sent by the group leader b, they parse the group member switching command message to obtain the synchronization deviation information of the source satellite and the destination satellite, and further calculate the synchronization deviation information to obtain the timing advance information between the current group leader device and the destination satellite.

[0138] Still as shown in Figures 3 and 4, as an optional implementation, the time when the source satellite A sends the synchronization signal is recorded as The propagation time of the synchronization signal sent by source satellite A is recorded as T SRC The time when the synchronization signal sent by the source satellite A reaches the group leader b is recorded as The time when the destination satellite B sends the synchronization signal is recorded as The propagation time of the synchronization signal sent by the destination satellite B is recorded as T TGT The time when the synchronization signal sent by the destination satellite B reaches the group leader b is recorded as It can be understood that the time relationship between the synchronization signals sent by the source satellite A and the destination satellite B can be expressed as the following formulas (1) and (2):

[0139] Furthermore, the synchronization deviation T between the source satellite A and the destination satellite B is calculated. DIFF It can be expressed as the following formula (3):

[0140] According to another aspect of an embodiment of the present application, a method for switching communication satellites is provided. The method is applied to group member devices of a group, where the group is obtained by grouping multiple user devices, and the group member devices are other user devices in the group except the group leader device. The multiple user devices are located in a coverage area of ​​a source satellite and are in communication connection with the source satellite. The method includes:

[0141] Step S31 : In response to a trigger of a cluster head device, the cluster head device switches from a source satellite to a destination satellite in a RACH-less switching manner, wherein the cluster head device switches from a source satellite to a destination satellite in a RACH switching manner.

[0142] In the technical solution provided by the present application, when the switching conditions are met, the group member device sends a group member switching request message to the group head device, and the group member switching request is used to request to switch the communication satellite from the source satellite to the destination satellite, wherein the switching conditions include: the difference between the fourth signal strength and the third signal strength is greater than the second threshold; wherein the third signal strength is the signal strength of the satellite signal received by the group member device from the source satellite, and the fourth signal strength is the signal strength of the satellite signal received by the group member device from the destination satellite.

[0143] In an optional embodiment, in step S31, responding to the triggering of the cluster head device and switching from the source satellite to the destination satellite in a RACH-less switching manner includes:

[0144] Step S311: receiving a group member switching command message sent by a group head device, wherein the information carried in the group member switching command message includes at least synchronization deviation information, which is used to determine the clock synchronization deviation between the source satellite and the destination satellite;

[0145] Step S312: Based on the uplink authorization information and the synchronization deviation information, the group member switching command message is generated by the switching response message returned by the source satellite and received by the group head device. The switching response message is a response message to the switching request message sent by the group head device to the source satellite through the random access channel. The switching response message is used to instruct the group head device to switch to a communication connection with the destination satellite.

[0146] Still as shown in FIG3 , in the technical solution provided by this application, the timing advance of the cluster head b to the source satellite A is the propagation time T of the synchronization signal sent by the source satellite A. SRC Twice as well, the timing advance of cluster head b to destination satellite B is the propagation time T of the synchronization signal sent by destination satellite B TGT Therefore, based on the synchronization deviation T between the source satellite A and the destination satellite B, DIFF Calculate the timing advance TA of the cluster leader b to the destination satellite B TGT It can be expressed as the following formula (4):

[0147] Still as shown in Figures 3 and 4, after the group head device completes the switching of the communication satellite according to the RACH switching method, the group member devices switch from the source satellite A to the destination satellite B according to the RACH-less switching method based on the group member switching command message sent by the group head device. After the switching is completed, the group member devices send a group member switching confirmation message to the destination satellite B. Furthermore, after the destination satellite B determines that the group member device has successfully switched to this satellite, it feeds back a switching completion message to the ground gateway station, and the gateway station then forwards the switching completion message to the source satellite A to notify the source satellite A to release communication resources (such as channel resources).

[0148] The above method will be further described below with reference to FIG5 .

[0149] FIG5 is a flowchart of another optional switching communication satellite process according to an embodiment of the present application. As shown in FIG5, when the source satellite and the destination satellite do not have the above-mentioned synchronization deviation, the group head device and the group user device in the group can calculate the above-mentioned timing advance information TA by the method shown in the following formula (5): TGT :

[0150] Still as shown in FIG5 , further, both the group head device and the group user device can switch communication satellites in a RACH-less switching manner based on the timing advance information shown in formula (5) and the above-mentioned uplink authorization information. Specifically, after the source satellite receives the switching request response message from the target satellite, it can simultaneously or time-share the corresponding group head switching command message and group member dedicated signaling message to the group head device and the group user device. After the group head device and the group user device complete the switching simultaneously or time-shared, they can simultaneously or time-share the group head switching confirmation message and group member switching confirmation message to the destination satellite.

[0151] In the above optional embodiments, the technical effect that can be achieved is: controlling the group head device and the group user device to switch the communication satellite according to different switching times and different switching methods, thereby reducing the signaling consumption in the network, alleviating network congestion, and effectively avoiding the problem of switching interruption, and also reducing the switching delay, improving the switching efficiency and success rate; in addition, according to the technical solution provided by the present application, the group head device and the group user device can execute different communication satellite switching schemes according to the synchronization deviation information of the source satellite and the destination satellite, thereby improving the flexibility of the method of switching communication satellites.

[0152] In this embodiment, a device for switching communication satellites is also provided. This device is used to implement the above-mentioned embodiments and preferred implementations, and details already described will not be repeated. As used below, a "module" refers to a combination of software and / or hardware that can implement a predetermined function. Although the devices described in the following embodiments are preferably implemented using software, implementation using hardware, or a combination of software and hardware, is also possible and contemplated.

[0153] FIG6 is a structural block diagram of an optional apparatus for switching communication satellites according to an embodiment of the present application. As shown in FIG6 , the apparatus includes:

[0154] A grouping module 601 is configured to group a plurality of user devices to obtain a grouping result, wherein the plurality of user devices are located in a coverage area of ​​a source satellite and are in communication with the source satellite, the grouping result including at least one group, and each group including at least one group head device;

[0155] The execution module 602 is configured to execute switching of the communication satellite of each group when a switching condition is met. The switching of the communication satellite of the group includes: the group head device switches from the source satellite to the destination satellite according to the RACH switching method, and the group member devices respond to the triggering of the group head device and switch from the source satellite to the destination satellite according to the RACH-less switching method. The group member devices are other user devices in the group except the group head device.

[0156] Optionally, the above-mentioned grouping module 601 is also configured to: group multiple user devices according to their geographical locations to obtain at least one group, wherein the user devices in each group in at least one group are located in the same cell; for each group in at least one group, determine the target user device from the user devices in the current group as the group head device corresponding to the current group.

[0157] Optionally, the above-mentioned grouping module 601 is also configured to: determine the target user device based on the average distance between each user device in the current group and other user devices in the current group; determine the target user device based on the distance between each user device in the current group and the regional center corresponding to the current group, wherein the regional center is the geographic center of the locations of all user devices in the current group; determine the target user device based on the received signal strength of each user device in the current group.

[0158] Optionally, the network side includes a source satellite, a destination satellite and a gateway station, and the above-mentioned execution module 602 is also configured to: the source satellite receives a first switching request message sent by the group head device, and sends a second switching request message to the gateway station based on the first switching request message, wherein the first switching request message includes: the measurement identification parameter and measurement result parameter corresponding to the group head device, and the second switching request message includes: the identifier of the destination satellite, the identifier of the group, the identifier of the group head device and the identifier of the group member device, the measurement identification parameter is determined by the identifier of the group head device and the identifier of the group member device, and the measurement result parameter is also used to determine the measurement result of the group member device; the gateway station sends a third switching request message to the destination satellite based on the second switching request message, receives the first switching response message returned by the destination satellite, and returns the second switching response message to the source satellite, wherein the third switching request message is used to characterize the switching requirement of the group head device, and the first switching response message includes : The access information corresponding to the group head device and the uplink authorization information corresponding to the group member devices, the second switching response message at least includes the uplink authorization information, the access information is determined by the current load of the destination satellite and the number of group member devices corresponding to the group head device, and the uplink authorization information is used to support the group member devices corresponding to the group head device to perform communication satellite switching in accordance with the RACH-less switching method; the source satellite sends a third switching response message to the group head device and a fourth switching response message to the group member devices according to the second switching response message, wherein the fourth switching response message includes at least the uplink authorization information, the third switching response message is used for the group head device to switch from the source satellite to the destination satellite in accordance with the RACH switching method, and the uplink authorization information is used for the group member devices to switch from the source satellite to the destination satellite in accordance with the RACH-less switching method.

[0159] Optionally, the switching conditions include: the difference between the second signal strength and the first signal strength is greater than a first threshold, and / or there are more than a preset number of group member devices in the group that meet the following conditions: the difference between the fourth signal strength and the third signal strength is greater than the second threshold; wherein the first signal strength is the signal strength of the satellite signal received by the group head device in the group from the source satellite, the second signal strength is the signal strength of the satellite signal received by the group head device in the group from the destination satellite to be switched, the third signal strength is the signal strength of the satellite signal received by the group member device from the source satellite, and the fourth signal strength is the signal strength of the satellite signal received by the group member device from the destination satellite.

[0160] Optionally, Figure 7 is a structural block diagram of another optional switching communication satellite device according to an embodiment of the present application. As shown in Figure 7, in addition to all the modules shown in Figure 6, the device also includes: a sorting module 603, which is configured to respond to the simultaneous existence of communication satellite switching requirements in at least two groups, perform priority analysis on at least two group head devices corresponding to at least two groups, and obtain a priority sorting result; according to the priority sorting result, control the at least two group head devices to switch from the source satellite to the destination satellite in sequence according to the RACH switching method.

[0161] According to another aspect of an embodiment of the present application, a communication network device is provided, including: a memory storing an executable program; and a processor for running the program, wherein when the program runs, any one of the aforementioned methods for switching communication satellites is executed.

[0162] Optionally, in this embodiment, the processor may be configured as a program for executing the following steps:

[0163] Step S1, performing grouping processing on a plurality of user devices to obtain a grouping result, wherein the plurality of user devices are located in a coverage area of ​​a source satellite and are in communication connection with the source satellite, the grouping result includes at least one group, and each group includes at least one group head device;

[0164] Step S2: For each group, when the switching conditions are met, the group's communication satellite is switched. The switching of the group's communication satellite includes: the group head device switches from the source satellite to the destination satellite according to the RACH switching method, and the group member devices respond to the triggering of the group head device and switch from the source satellite to the destination satellite according to the RACH-less switching method. The group member devices are other user devices in the group except the group head device.

[0165] According to another aspect of an embodiment of the present application, a computer-readable storage medium is provided, the storage medium including a stored program, wherein when the program is running, the device where the storage medium is located is controlled to execute any of the aforementioned methods for switching communication satellites.

[0166] Optionally, in this embodiment, the computer-readable storage medium may include, but is not limited to, various media that can store programs, such as a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk, or an optical disk.

[0167] Optionally, in this embodiment, the computer-readable storage medium may be configured to store a program for executing the following steps:

[0168] Step S1, performing grouping processing on a plurality of user devices to obtain a grouping result, wherein the plurality of user devices are located in a coverage area of ​​a source satellite and are in communication connection with the source satellite, the grouping result includes at least one group, and each group includes at least one group head device;

[0169] Step S2: For each group, when the switching conditions are met, the group's communication satellite is switched. The switching of the group's communication satellite includes: the group head device switches from the source satellite to the destination satellite according to the RACH switching method, and the group member devices respond to the triggering of the group head device and switch from the source satellite to the destination satellite according to the RACH-less switching method. The group member devices are other user devices in the group except the group head device.

[0170] Optionally, specific examples in this embodiment may refer to the examples described in the above embodiment and its optional implementation manners, and this embodiment will not be described in detail here.

[0171] The serial numbers of the above embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0172] In the above embodiments of the present application, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0173] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only exemplary. For example, the division of the units can be a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0174] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0175] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0176] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the relevant technology or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, a server or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk.

[0177] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for switching a communication satellite, the method being applied to a network side, the method comprising: Performing grouping processing on a plurality of user devices to obtain a grouping result, wherein the plurality of user devices are located in a coverage area of ​​a source satellite and are in communication connection with the source satellite, the grouping result includes at least one group, and each of the groups includes at least one group head device; For each of the groups, when a switching condition is met, performing switching of the communication satellites of the group; The switching of the communication satellites of the group includes: The group head device switches from the source satellite to the destination satellite according to the RACH switching method, and the group member devices respond to the triggering of the group head device and switch from the source satellite to the destination satellite according to the RACH-less switching method, wherein the group member devices are other user devices in the group except the group head device.

2. The method according to claim 1, wherein: A plurality of user devices are grouped and the grouping results include: Grouping the multiple user equipments according to their geographical locations to obtain at least one group, wherein the user equipments in each group of the at least one group are located in the same cell; For each group in the at least one group, a target user equipment is determined from the user equipments in the current group as a group head device corresponding to the current group.

3. The method according to claim 2, wherein: For each group in the at least one group, determining the target user equipment from the user equipment in the current group includes one of the following: Determining the target user equipment according to an average distance between each user equipment in the current group and other user equipment in the current group; Determine the target user equipment according to the distance between each user equipment in the current group and the regional center corresponding to the current group, wherein the regional center is the geographical center of the locations of all user equipment in the current group; The target user equipment is determined according to the received signal strength of each user equipment in the current group.

4. The method according to claim 1, wherein: The network side includes a source satellite, a destination satellite and a gateway station, and executing the switching of the communication satellites of the group includes: The source satellite receives a first switching request message sent by the cluster head device, and sends a second switching request message to the gateway based on the first switching request message, wherein the first switching request message includes: a measurement identification parameter and a measurement result parameter corresponding to the cluster head device, and the second switching request message includes: The information includes: an identifier of the destination satellite, an identifier of the group, an identifier of the group head device, and an identifier of the group member device, the measurement identifier parameter is determined by the identifier of the group head device and the identifier of the group member device, and the measurement result parameter is also used to determine the measurement result of the group member device; The gateway sends a third switching request message to the destination satellite based on the second switching request message, receives a first switching response message returned by the destination satellite, and returns a second switching response message to the source satellite, wherein the third switching request message is used to characterize the switching demand of the group head device, the first switching response message includes: admission information corresponding to the group head device and uplink authorization information corresponding to the group member devices, the second switching response message includes at least the uplink authorization information, the admission information is determined by the current load of the destination satellite and the number of group member devices corresponding to the group head device, and the uplink authorization information is used to support the group member devices corresponding to the group head device to perform communication satellite switching according to the RACH-less switching method; The source satellite sends a third switching response message to the group head device and a fourth switching response message to the group member device according to the second switching response message, wherein the fourth switching response message at least includes the uplink authorization information, the third switching response message is used by the group head device to switch from the source satellite to the destination satellite according to the RACH switching method, and the uplink authorization information is used by the group member device to switch from the source satellite to the destination satellite according to the RACH-less switching method.

5. The method according to claim 1, wherein: The switching conditions include: The difference between the second signal strength and the first signal strength is greater than the first threshold, and / or, there are more than a preset number of group member devices in the group that meet the following conditions: the difference between the fourth signal strength and the third signal strength is greater than the second threshold; Among them, the first signal strength is the signal strength of the satellite signal received by the group head device in the group from the source satellite, the second signal strength is the signal strength of the satellite signal received by the group head device in the group from the destination satellite to be switched, the third signal strength is the signal strength of the satellite signal received by the group member device from the source satellite, and the fourth signal strength is the signal strength of the satellite signal received by the group member device from the destination satellite.

6. The method according to claim 1, wherein: The method further comprises: In response to at least two groups having communication satellite switching requirements at the same time, performing priority analysis on at least two group head devices corresponding to the at least two groups to obtain a priority sorting result; According to the priority sorting result, the at least two group head devices are controlled to switch from the source satellite to the destination satellite in sequence according to the RACH switching mode.

7. A method for switching communication satellites, the method being applied to a group head device of a group, the group being obtained by grouping a plurality of user devices, the plurality of user devices being located in a coverage area of ​​a source satellite and being in communication connection with the source satellite, and when a switching condition is met, the method comprising: The group head device switches from the source satellite to the destination satellite according to the RACH switching mode, and triggers the group member devices to switch from the source satellite to the destination satellite according to the RACH-less switching mode, wherein the group member devices are other user devices in the group except the group head device.

8. The method according to claim 7, wherein: The method further includes: when a switching condition is met, the cluster head device sends a first switching request message to the source satellite, wherein the first switching request message is used to request to switch the communication satellite from the source satellite to the destination satellite; The switching conditions include: the difference between the second signal strength and the first signal strength is greater than a first threshold, and / or there are more than a preset number of group member devices in the group that meet the following conditions: the difference between the fourth signal strength and the third signal strength is greater than the second threshold; wherein the first signal strength is the signal strength of the satellite signal received by the group head device in the group from the source satellite, the second signal strength is the signal strength of the satellite signal received by the group head device in the group from the destination satellite to be switched, the third signal strength is the signal strength of the satellite signal received by the group member device from the source satellite, and the fourth signal strength is the signal strength of the satellite signal received by the group member device from the destination satellite.

9. The method according to claim 7, wherein: Triggering a group member device to switch from the source satellite to the destination satellite according to the RACH-less switching mode includes: A group member switching command message is sent to the group member device to assist the group member device in switching from the source satellite to the destination satellite according to the RACH-less switching method based on the uplink authorization information and the group member switching command message, wherein the information carried in the group member switching command message includes at least synchronization deviation information, and the synchronization deviation information is used to determine the clock synchronization deviation between the source satellite and the destination satellite, and the uplink authorization information is sent by the source satellite to the group member device.

10. The method according to claim 8, wherein: Switching from the source satellite to the destination satellite according to the RACH switching mode includes: Sending a first switching request message to the source satellite through a random access channel, wherein the first switching request message is used to request switching to communicate with the destination satellite, and the first switching request message includes: a measurement identification parameter and a measurement result parameter corresponding to the group head device, the measurement identification parameter is determined by an identification of the group head device and an identification of the group member device, and the measurement result parameter is also used to determine a measurement result of the group member device; receiving a third switching response message returned by the source satellite, wherein the third switching response message is used to instruct the cluster head device to switch to a communication connection with the destination satellite; The device switches from the source satellite to the destination satellite according to the third switching response message.

11. The method according to claim 10, wherein: The method further comprises: Acquire a first moment, a second moment, a third moment, and a fourth moment, wherein the first moment is the moment when the source satellite sends a first synchronization signal, the second moment is the moment when the cluster head device receives the first synchronization signal, the third moment is the moment when the destination satellite sends a second synchronization signal, and the fourth moment is the moment when the cluster head device receives the second synchronization signal; A first propagation time of the first synchronization signal is calculated according to the first moment and the second moment, and a second propagation time of the second synchronization signal is calculated according to the third moment and the fourth moment; The synchronization deviation information is calculated using the first propagation time and the second propagation time.

12. A method for switching communication satellites, the method being applied to group member devices of a group, the group being obtained by grouping a plurality of user devices, the group member devices being other user devices in the group except a group head device, the plurality of user devices being located in a coverage area of ​​a source satellite and being in communication connection with the source satellite, the method comprising: In response to the triggering of the cluster head device, the cluster head device switches from the source satellite to the destination satellite in a RACH-less switching manner, wherein the cluster head device switches from the source satellite to the destination satellite in a RACH switching manner.

13. The method according to claim 12, wherein: The method further comprises: when a switching condition is met, the group member device sends a group member switching request message to the group head device, wherein the group member switching request is used to request to switch the communication satellite from the source satellite to the destination satellite; The switching condition includes: a difference between the fourth signal strength and the third signal strength is greater than a second threshold; wherein the third signal strength is the signal strength of the satellite signal received by the group member device from the source satellite, and the fourth signal strength is the signal strength of the satellite signal received by the group member device from the destination satellite.

14. The method according to claim 13, wherein: Responding to the triggering of the group head device and switching from the source satellite to the destination satellite in a RACH-less switching manner includes: Receiving a group member switching command message sent by the group head device, wherein the information carried in the group member switching command message includes at least: synchronization deviation information, the synchronization deviation information is used to determine the clock synchronization deviation between the source satellite and the destination satellite; Based on uplink authorization information and the synchronization deviation information, switching from the source satellite to the destination satellite in the RACH-less switching mode, wherein the uplink authorization information is sent by the source satellite to the group member device; The group member switching command message is generated by a switching response message returned by the source satellite and received by the group head device, and the switching response message is a response message of a switching request message sent by the group head device to the source satellite through a random access channel, and the switching response message is used to instruct the group head device to switch to a communication connection with the destination satellite.

Images