Method for switching a communication satellite

Abstract

The application discloses a method for switching communication satellites. The method comprises the following steps: grouping a plurality of user equipment to obtain a grouping result; for each group, when a switching condition is met, performing switching of a communication satellite of the group; wherein the switching of the communication satellite of the group comprises: a group leader device switching from a source satellite to a target satellite according to a RACH switching mode, and group member devices switching from the source satellite to the target satellite according to a RACH-less switching mode in response to triggering of the group leader device, wherein the group member devices are other user equipment in the group except the group leader device. The application solves the technical problems of network congestion, switching interruption and increased switching delay caused by large signaling overhead in the prior art during switching of communication satellites.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of mobile communication, in particular to a method for switching communication satellites. BACKGROUND

[0002] In order to increase the coverage of mobile communication, mobile communication has been expanded from the traditional ground network to the space-air network. 3GPP has started to study non-ground networks from Rel-16, and has entered the WI stage in Rel-17 to discuss the standardization of specific technologies.

[0003] With the development of network technology, the number of users and the amount of business are growing rapidly, and low-orbit satellites will gradually face the scenario of dense users. When the number of ground users is within a certain range, a large number of users will simultaneously send switching request messages to the target satellite. For a satellite communication system with limited resources, simultaneous switching management services will cause resource competition and conflict and generate a large amount of signaling overhead. In addition, frequent switching will generate a large number of request messages, which can easily lead to network congestion, switching interruption, and increased switching delay.

[0004] In view of the above problems of the prior art that the large signaling overhead in the process of switching communication satellites leads to network congestion, switching interruption, and increased switching delay, no effective solution has been proposed so far. SUMMARY

[0005] The embodiments of the present application provide a method for switching communication satellites to at least solve the technical problem of the prior art that the large signaling overhead in the process of switching communication satellites leads to network congestion, switching interruption, and increased switching delay.

[0006] According to an aspect of the embodiments of the present application, a method for switching communication satellites is provided, comprising:

[0007] grouping a plurality of user equipment to obtain a grouping result, wherein the plurality of user equipment is located in a coverage area of a source satellite and is in communication connection with the source satellite, the grouping result includes at least one group, and each group includes at least one group leader device; for each group, when a switching condition is met, performing switching of the communication satellite of the group; wherein the switching of the communication satellite of the group includes: the group leader device switches from the source satellite to a target satellite according to a RACH switching mode, and a group member device switches from the source satellite to the target satellite according to a RACH-less switching mode in response to triggering of the group leader device, wherein the group member device is other user equipment in the group except the group leader device.

[0008] Optionally, the plurality of user equipments are grouped to obtain a grouping result, including: grouping the plurality of user equipments according to geographical positions of the plurality of user equipments to obtain at least one group, wherein user equipments in each group of the at least one group are located in a same cell; and for each group of the at least one group, determining a target user equipment from the user equipments in the current group as a group leader corresponding to the current group.

[0009] Optionally, the determining the target user equipment from the user equipments in the current group includes one of: determining the target user equipment according to average distances between each user equipment in the current group and other user equipments in the current group; determining the target user equipment according to distances between each user equipment in the current group and a region center corresponding to the current group, wherein the region center is a geographical center of positions of all user equipments in the current group; and determining the target user equipment according to received signal strengths of each user equipment in the current group.

[0010] Optionally, the network side comprises a source satellite, a target satellite and a gateway station, and the switching of the communication satellite of the group comprises: the source satellite receiving a first switching request message sent by the group leader device, and sending a second switching request message to the gateway station based on the first switching request message, wherein the first switching request message comprises a measurement identifier parameter and a measurement result parameter corresponding to the group leader device, and the second switching request message comprises an identifier of the target satellite, an identifier of the group, an identifier of the group leader device and an identifier of the group member device, the measurement identifier parameter is determined by the identifier of the group leader device and the identifier of the group member device, and the measurement result parameter is further used to determine the measurement result of the group member device; the gateway station sends a third switching request message to the target satellite based on the second switching request message, receives a first switching response message returned by the target satellite, and returns a second switching response message to the source satellite, wherein the third switching request message is used to represent the switching demand of the group leader device, the first switching response message comprises admission information corresponding to the group leader device and uplink authorization information corresponding to the group member device, and the second switching response message at least comprises the uplink authorization information, the admission information is determined by the current load of the target satellite and the number of the group member device corresponding to the group leader device, and the uplink authorization information is used to support the group member device corresponding to the group leader device to perform the communication satellite switching in the RACH-less switching mode; the source satellite sends a third switching response message to the group leader 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 comprises the uplink authorization information, the third switching response message is used for the group leader device to switch from the source satellite to the target satellite in the RACH switching mode, and the uplink authorization information is used for the group member device to switch from the source satellite to the target satellite in the RACH-less switching mode; and / or, the switching condition comprises that 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 satisfy the following condition: 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 leader device in the group from the source satellite, the second signal strength is the signal strength of the satellite signal received by the group leader device in the group from the target 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 target satellite; and / or, in response to the simultaneous existence of the communication satellite switching demand of at least two groups, priority analysis is performed on at least two group leader devices corresponding to the at least two groups to obtain a priority sorting result; and the at least two group leader devices are controlled to switch from the source satellite to the target satellite in the RACH switching mode in turn according to the priority sorting result.

[0011] According to another aspect of the embodiments of the present application, a method for switching communication satellites is also provided. The method is applied to a group leader 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. When a switching condition is met, the method comprises: switching, by the group leader device, from the source satellite to a target satellite in a RACH switching mode, and triggering group member devices to switch from the source satellite to the target satellite in a RACH-less switching mode, wherein the group member devices are other user devices in the group except the group leader device.

[0012] Optionally, the method for switching communication satellites further comprises: when the switching condition is met, sending, by the group leader device, a first switching request message to the source satellite, the first switching request message being used to request switching of the communication satellite from the source satellite to the target satellite; the switching condition comprises: a difference between the second signal strength and the first signal strength being greater than a first threshold, and / or there being more than a preset number of group member devices in the group that satisfy a condition that a difference between the fourth signal strength and the third signal strength is greater than a second threshold; wherein the first signal strength is a signal strength of a satellite signal received by the group leader device in the group from the source satellite, the second signal strength is a signal strength of a satellite signal received by the group leader device in the group from the target satellite to be switched, the third signal strength is a signal strength of a satellite signal received by the group member devices from the source satellite, and the fourth signal strength is a signal strength of a satellite signal received by the group member devices from the target satellite; and / or switching from the source satellite to the target satellite in the RACH switching mode comprises: 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 be in communication connection with the target satellite, the first switching request message comprises a measurement identifier parameter corresponding to the group leader device and a measurement result parameter, the measurement identifier parameter is determined by an identifier of the group leader device and an identifier of the group member devices, and the measurement result parameter is further used to determine a measurement result of the group member devices; receiving a third switching response message returned by the source satellite, wherein the third switching response message is used to instruct the group leader device to switch to be in communication connection with the target satellite; and switching from the source satellite to the target satellite according to the third switching response message.

[0013] Optionally, triggering the group member devices to switch from the source satellite to the target satellite in the RACH-less switching mode comprises: sending a group member switching command message to the group member devices to assist the group member devices in switching from the source satellite to the target satellite in the RACH-less switching mode based on uplink authorization information and the group member switching command message, wherein information carried in the group member switching command message at least comprises synchronization offset information, the synchronization offset information being used to determine a clock synchronization offset between the source satellite and the target satellite, and the uplink authorization information is sent by the source satellite to the group member devices.

[0014] Optionally, the method further comprises: obtaining a first time, a second time, a third time and a fourth time, wherein the first time is a time when the first synchronization signal is sent by the source satellite, the second time is a time when the first synchronization signal is received by the group leader device, the third time is a time when the second synchronization signal is sent by the target satellite, and the fourth time is a time when the second synchronization signal is received by the group leader device; calculating a first propagation time of the first synchronization signal according to the first time and the second time, and calculating a second propagation time of the second synchronization signal according to the third time and the fourth time; and calculating the synchronization deviation information by using the first propagation time and the second propagation time.

[0015] According to another aspect of the embodiments of the present application, a method for switching communication satellites is also provided. The method is applied to a group member device of a group, the group is obtained by grouping a plurality of user devices, the group member device is a user device other than a group leader device in the group, 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. The method comprises: switching from the source satellite to a target satellite according to a RACH-less switching mode in response to a trigger of the group leader device, wherein the group leader device switches from the source satellite to the target satellite according to a RACH switching mode.

[0016] Optionally, the method further comprises: when a switching condition is met, sending, by the group member device, a group member switching request message to the group leader device, the group member switching request message being used to request switching of the communication satellite from the source satellite to the target satellite; the switching condition comprises: a difference between a fourth signal strength and a third signal strength is greater than a second threshold; the third signal strength is a signal strength of a satellite signal received by the group member device from the source satellite, and the fourth signal strength is a signal strength of a satellite signal received by the group member device from the target satellite; and / or switching from the source satellite to the target satellite according to the RACH-less switching mode in response to the trigger of the group leader device comprises: receiving a group member switching command message sent by the group leader device, wherein information carried in the group member switching command message at least comprises: synchronization deviation information used to determine a clock synchronization deviation between the source satellite and the target satellite; calculating timing advance information according to the synchronization deviation information, wherein the timing advance information is used to represent timing advance between the group member device and the target satellite; and switching from the source satellite to the target satellite according to the RACH-less switching mode based on uplink grant information and the timing advance information, wherein the uplink grant information is sent to the group member device by the source satellite.

[0017] According to another aspect of the embodiments of the present application, a device for switching communication satellites is also provided. The device comprises:

[0018] The grouping module is configured to group a plurality of user equipment to obtain a grouping result, wherein the plurality of user equipment are located in a coverage area of a source satellite and are in communication connection with the source satellite, and the grouping result comprises at least one group, and each group comprises at least one group leader device; the execution module is configured to, for each group, perform switching of a communication satellite of the group when a switching condition is met; wherein the switching of the communication satellite of the group comprises: the group leader device switches from the source satellite to a target satellite according to a RACH switching mode, and group member devices switch from the source satellite to the target satellite according to a RACH-less switching mode in response to triggering of the group leader device, wherein the group member devices are user equipment other than the group leader device in the group.

[0019] Optionally, the grouping module is further configured to group the plurality of user equipment according to geographical positions of the plurality of user equipment to obtain at least one group, wherein user equipment in each group of the at least one group is located in a same cell; and for each group of the at least one group, determine a target user equipment from the user equipment in the current group as a group leader device corresponding to the current group.

[0020] Optionally, the grouping module is further configured to determine 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 a distance between each user equipment in the current group and a region center corresponding to the current group, wherein the region center is a geographical center of positions of all user equipment in the current group; and determine the target user equipment according to a received signal strength of each user equipment in the current group.

[0021] Optionally, the network side comprises a source satellite, a target satellite and a gateway station, and the execution module is further configured to: receive, by the source satellite, the first handover request message sent by the group leader device, and send, by the source satellite, a second handover request message to the gateway station based on the first handover request message, wherein the first handover request message comprises a measurement identifier parameter and a measurement result parameter corresponding to the group leader device, and the second handover request message comprises an identifier of the target satellite, an identifier of the group, an identifier of the group leader device and an identifier of the group member device, the measurement identifier parameter is determined by the identifier of the group leader device and the identifier of the group member device, and the measurement result parameter is further used to determine the measurement result of the group member device; send, by the gateway station, a third handover request message to the target satellite based on the second handover request message, receive a first handover response message returned by the target satellite, and return 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 leader device, the first handover response message comprises admission information corresponding to the group leader device and uplink authorization information corresponding to the group member device, and the second handover response message at least comprises the uplink authorization information, the admission information is determined by the current load of the target satellite and the number of the group member devices corresponding to the group leader device, and the uplink authorization information is used to support the group member devices corresponding to the group leader device to perform satellite handover in a RACH-less handover mode; send, by the source satellite, a third handover response message to the group leader device and a fourth handover response message to the group member device according to the second handover response message, wherein the fourth handover response message at least comprises the uplink authorization information, and the third handover response message is used to enable the group leader device to perform satellite handover from the source satellite to the target satellite in a RACH handover mode, and the uplink authorization information is used to enable the group member device to perform satellite handover from the source satellite to the target satellite in a RACH-less handover mode; and / or the handover condition comprises that a difference between the second signal strength and the first signal strength is greater than a first threshold value, and / or there are more than a preset number of group member devices in the group that satisfy the following condition: a difference between the fourth signal strength and the third signal strength is greater than a second threshold value; wherein the first signal strength is a signal strength of satellite signals received by the group leader device in the group from the source satellite, the second signal strength is a signal strength of satellite signals received by the group leader device in the group from the target satellite to be handed over, the third signal strength is a signal strength of satellite signals received by the group member device from the source satellite, and the fourth signal strength is a signal strength of satellite signals received by the group member device from the target satellite; and / or in response to the existence of satellite handover requirements of at least two groups at the same time, priority analysis is performed on at least two group leader devices corresponding to the at least two groups to obtain a priority ranking result, and the at least two group leader devices are controlled to perform satellite handover from the source satellite to the target satellite in a RACH handover mode in sequence according to the priority ranking result.

[0022] According to another aspect of the embodiments of the present application, a communication network device is also provided, comprising a memory storing an executable program and a processor configured to run the program, wherein the program is configured to perform the method for switching communication satellites according to any one of the preceding embodiments.

[0023] According to another aspect of an embodiment of the present invention, a computer-readable storage medium is provided, which includes a stored program, wherein when the program is run, the device where the storage medium is located is controlled to execute any of the aforementioned methods for switching communication satellites.

[0024] In an embodiment of the present invention, a plurality of user devices are first 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, each group including at least one group head device, and finally, 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 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.

[0025] It is easy to understand that the above-mentioned method provided by the present invention, after grouping multiple user devices to obtain a group head device and group member devices, 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 the existing technology in the process of switching communication satellites due to large signaling overhead leading to network congestion, switching interruption, and increased switching delay. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0027] Figure 1 is a flow chart of a method for switching communication satellites according to an embodiment of the present invention;

[0028] Figure 2 is a schematic diagram of grouping in a process of switching communication satellites according to an optional embodiment of the present invention;

[0029] Figure 3 is a schematic diagram of an optional process of switching communication satellites according to an embodiment of the present invention;

[0030] Figure 4 is a flow chart of an optional process of switching communication satellites according to an embodiment of the present invention;

[0031] Figure 5 is a flow chart of another optional switching communication satellite process according to an embodiment of the present application;

[0032] Figure 6 is a structural block diagram of an optional switching communication satellite device according to an embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the person skilled in the art better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0034] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0035] In the process of describing the embodiments of the present application, some nouns or terms appearing are applicable to the following explanations:

[0036] Third Generation Partnership Project (3GPP): an international mobile communication standardization organization, whose purpose is to develop technical specifications applicable to various wireless communication technologies (such as 2G, 3G, 4G and 5G) worldwide, and to promote interoperability and compatibility between different operators and different devices. 3GPP communication standards can include but are not limited to: Long-Term Evolution (LTE), Voice over LTE (VoLTE) based on LTE network, Narrowband Internet of Things (NB-IoT).

[0037] Non-Terrestrial Network (NTN): A communication network that does not rely on ground-based infrastructure, but uses satellites, airships, drones, and other non-ground devices to build up.

[0038] Work Item (WI): In an international standards organization or association, a work item refers to an ongoing but not yet completed research and discussion project related to a specific topic.

[0039] Rel-16, Rel-17, Rel-18: Refers to the 16th, 17th, and 18th versions of technical specifications released by 3GPP, respectively, each version has different features, extended functions and performance targets.

[0040] User Equipment (UE): Refers to terminal equipment in mobile communication systems, which can be but is not limited to: mobile phones, tablets.

[0041] 5G NR (5G New Radio): A wireless communication system based on new 5G air interface and protocol architecture, which provides higher transmission speed, lower latency and larger network capacity than existing LTE and WiFi.

[0042] Random Access Response (RAR): Used to respond to UE-initiated random access requests (RACH attempts).

[0043] Timing Advance (TA): In satellite communication systems, due to the distance between UE and satellite, it is necessary to adjust the transmission time to make the signal arrival time more synchronized, TA is a parameter used to calculate this time offset, after receiving the TA request from the base station or satellite, UE adjusts according to its own position and motion state and other information.

[0044] UpLink grant (UL grant): Refers to a kind of authorization message issued by the base station or satellite to the terminal device, which informs it that it can start uploading data and informs the required resource, transmission format and power parameters.

[0045] Low Earth Orbit (LEO) satellite network: A wireless communication technology based on small, low-altitude satellites operating in low earth orbit, which realizes wide area coverage and communication transmission through networking.

[0046] 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, up / down switching).

[0047] ServingCellConfigCommon: A parameter in LTE systems used to configure cell broadcast information and shared network resources related settings.

[0048] DownlinkConfigCommon: A parameter in LTE systems used to configure downlink control information and resource allocation related settings, including but not limited to downlink frequency point configuration, initial downlink BWP, BCCH configuration, PCCH configuration.

[0049] Bandwidth Part (BWP): Defined as a set of contiguous resource blocks, used to transmit data or control information.

[0050] BCCH configuration (Broadcast Control Channel): A basic configuration in mobile communication systems, used to broadcast control information.

[0051] Paging Control Channel (PCCH): A channel used for paging and allocating frequency resources in mobile communication systems.

[0052] ReconfigurationWithSync: A configuration management technology for distributed systems, which can dynamically modify and update configuration information during system operation, and ensure that these modifications and updates can be synchronized to all nodes.

[0053] t304 in ReconfigurationWithSync: Used to indicate the UE random access to the relevant SpCell timer duration.

[0054] SpCell timer: Used to control the switching operation time between different cells (SpCell).

[0055] SMTC (Short Maximum Time-to-Trigger for Cell Change): A measurement configuration parameter in LTE, which limits the duration and period of UE measurement on specific resources.

[0056] Radio Resource Control (RRC) configuration information: refers to the control signaling in the wireless access network, used to reconfigure and update the communication parameters between the UE and the base station, which can include but is not limited to: frequency, bandwidth, power, scheduling algorithm.

[0057] UplinkConfigCommon: used to store configuration options related to network connection communication, including but not limited to: protocol type, IP address, port number, authentication information.

[0058] Single Sideband Communication (SSB): a modulation method in which only one sideband and carrier are transmitted, and the other sideband is suppressed, thereby reducing power consumption and improving transmission distance and quality.

[0059] Channel State Information Reference Signal (CSI-RS): a technical means for obtaining information related to the frequency response, noise, etc. between the user equipment and the base station in a wireless communication system.

[0060] Service Set Identifier (SSID): an identifier used to distinguish different wireless networks.

[0061] Dijkstra algorithm: an algorithm for finding the shortest path in a weighted graph, which gradually expands the path by constantly selecting the node closest to the starting point that has not been visited, and uses a priority queue to quickly find the next node to be visited. After the algorithm runs, each node will record the shortest path length from the starting point to the node and which nodes are included in the path.

[0062] Based on the problem of large signaling overhead in the prior art during the switching of communication satellites, which leads to network congestion, switching interruption, and increased switching delay, according to an embodiment of the present application, a method for 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 the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0063] Figure 1 is a flowchart of a method for switching communication satellites according to an embodiment of the present application, as shown in Figure 1 the method comprises the following steps:

[0064] Step S11, a plurality of user equipment is grouped, and a grouping result is obtained, wherein the plurality of user equipment is located in a coverage area of a source satellite and is in communication connection with the source satellite, the grouping result includes at least one group, and each group includes at least one group leader device;

[0065] The plurality of user equipment can be terminal equipment capable of interacting with a network and exchanging information. In the field of mobile communication, the user equipment can include, but is not limited to, a smart phone, a tablet computer, and a notebook computer. It can also be understood that in the 5G era, the user equipment can also include new intelligent devices (such as Internet of Things nodes), vehicle-mounted terminals, industrial controllers, and the like. It should be noted that the plurality of user equipment can be located in the same coverage area of the source satellite, or can be distributed in different coverage areas of the source satellite. The group leader device can be used to schedule and manage other user equipment in the group, and allocate resources for each user equipment in the group.

[0066] It should be noted that the grouping of the user equipment is based on a group switching technology. Group switching is a switching mechanism in a mobile communication network, which is used to switch a group of devices when a mobile device switches from one communication satellite (or base station) to another communication satellite (or base station), so as to maintain continuous communication between the devices.

[0067] In an optional solution provided by the application, a plurality of devices is grouped to obtain a grouping result. The specific method can be: according to the discrete degree of the geographical position of each user equipment, the plurality of user equipment is divided into a plurality of groups, the average distance of each user equipment in the group to all other user equipment is calculated, the average distances corresponding to each user equipment are compared to determine the user equipment corresponding to the minimum average distance, and the user equipment corresponding to the minimum average distance is determined as the group leader device.

[0068] Step S12, for each group, when the switching condition is met, the communication satellite of the group is switched; wherein the communication satellite of the group is switched, including: the group leader device switches from the source satellite to the destination satellite according to the RACH switching mode, and the group member device switches from the source satellite to the destination satellite according to the RACH-less switching mode in response to the trigger of the group leader device, wherein the group member device is other user equipment in the group except the group leader device.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] In an embodiment of the present invention, a plurality of user devices are first 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, each group including at least one group head device, and finally, 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 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.

[0073] It is easy to understand that the above-mentioned method provided by the present invention, after grouping multiple user devices to obtain a group head device and group member devices, 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 the existing technology in the process of switching communication satellites due to large signaling overhead leading to network congestion, switching interruption, and increased switching delay.

[0074] The above method of the above embodiment of the present invention is further introduced below.

[0075] In an optional embodiment, in step S11, grouping is performed on multiple user equipments, and obtaining a grouping result includes:

[0076] 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;

[0077] 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.

[0078] In the technical solution provided by the present invention, 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.

[0079] 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.

[0080] 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:

[0081] 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;

[0082] Step S1122, determining the target user equipment according to the distance between each user equipment in the current group and the region center corresponding to the current group, wherein the region center is the geographic center of the locations of all user equipments in the current group;

[0083] Step S1123, determining the target user equipment according to the received signal strength of each user equipment in the current group.

[0084] The above steps S1121 to S1123 are further described as follows. Figure 2 The above steps S1121 to S1123 are further described as follows.

[0085] Figure 2 is a schematic diagram of a group switching process in a communication satellite according to an embodiment of the present application, as shown in Figure 2 As an optional implementation, a geographic position grouping algorithm based on average distance is used to calculate the average distance from each user equipment in each group to all other user equipments in the group, and the user equipment with the smallest average distance to all other user equipments in the group is selected as the group leader of the current group. It can be understood that the group leader selected by the geographic position grouping algorithm based on average distance receives a signal strength close to the average received signal strength of all group member devices, and the communication distance between the group leader and the group member devices is small.

[0086] As another optional implementation, a geographic position grouping algorithm based on region center is used to select the user equipment closest to the geographic center as the group leader. It can be understood that the geographic position grouping algorithm based on region center has low complexity, and the group leader selected by this method receives a signal strength close to the average received signal strength of the group member devices.

[0087] As yet another optional implementation, a geographic position grouping algorithm based on received signal strength is used to select the user equipment with the largest received signal strength as the group leader. It can be understood that the group leader selected by the geographic position grouping algorithm based on received signal strength is close to the edge of the satellite coverage area, and can quickly determine the need for switching to the communication satellite, but this method has the problems of large difference in received signal strength between the group leader and the group member devices, and large communication distance between the group leader and the group member devices.

[0088] In the optional embodiment, the technical effects achieved are that the group leader device and the group member devices of the group can be quickly determined according to one of the plurality of grouping algorithms, the grouping efficiency is improved, thereby facilitating the group leader device to send a switching request message to the source satellite in the subsequent process to reduce the number of request messages in the network, and the selected group leader device and the other group member devices are switched from the source satellite to the target satellite in different switching manners, thereby solving the technical problems of network congestion, switching interruption and increased switching time delay caused by large signaling overhead in the prior art in the process of switching communication satellites.

[0089] In an optional embodiment, in step S12, the network side includes the source satellite, the target satellite and the gateway station, and the switching of the communication satellite of the group includes:

[0090] In step S121, the source satellite receives the first switching request message sent by the group leader 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 identifier parameter and the measurement result parameter corresponding to the group leader device, the second switching request message includes the identifier of the target satellite, the identifier of the group, the identifier of the group leader device and the identifier of the group member device, the measurement identifier parameter is determined by the identifier of the group leader device and the identifier of the group member device, and the measurement result parameter is further used to determine the measurement result of the group member device;

[0091] In step S122, the gateway station sends a third switching request message to the target satellite based on the second switching request message, receives a first switching response message returned by the target satellite, and returns a second switching response message to the source satellite, wherein the third switching request message is used to represent the switching demand of the group leader device, the first switching response message includes the admission information corresponding to the group leader device and the uplink authorization information corresponding to the group member device, and the second switching response message at least includes the uplink authorization information, the admission information is determined by the current load of the target satellite and the number of the group member devices corresponding to the group leader device, and the uplink authorization information is used to support the group member devices corresponding to the group leader device to perform communication satellite switching in the RACH-less switching manner;

[0092] In step S123, the source satellite sends a third switching response message to the group leader 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 at least includes the uplink authorization information, the third switching response message is used for the group leader device to switch from the source satellite to the target satellite in the RACH switching manner, and the uplink authorization information is used for the group member devices to switch from the source satellite to the target satellite in the RACH-less switching manner.

[0093] The gateway station can be a device for providing network connection and forwarding data in a mobile communication process, and can also be used for detecting and processing security risks in a data transmission process. The access information is used to determine whether the target satellite accepts switching of the user equipment (including the group head device and the corresponding group member device) to the satellite.

[0094] The above method is further described below. Figure 3 , Figure 4 The above method is further described below.

[0095] Figure 3 is a schematic diagram of an optional switching communication satellite process according to an embodiment of the present application, Figure 4 is a flowchart of an optional switching communication satellite process according to an embodiment of the present application, as shown in Figure 3 , 4 Before switching the communication satellite, a plurality of user equipment can be grouped into a plurality of groups by using a geographical location grouping algorithm, and a group head device (such as the group heads a, b and c shown in Figure 3 ) can be selected in each group. In addition, one or more group member devices (such as the group members 1 to 7 shown in Figure 3 ) can also be included in each group.

[0096] As shown in Figure 3 , 4 , the group head device (the group head b shown in Figure 3 ) in a certain group determines whether the group needs to switch the communication satellite according to the measured service signal strength (i.e., the signal strength of the source satellite A and the target satellite B). Specifically, for example, the group head b measures the received signal power of the source satellite A as P1 and the signal power of the target satellite B as P2. When the group head b detects that the difference between P2 and P1 is greater than the power switching threshold P th , it is determined that the group needs to switch the communication satellite, and then the group head b sends a switching request message (i.e., the first switching request message) to the source satellite A. Specifically, the measurement identification parameter measID in the first switching request message corresponding signaling is added to the IDs of the group members (the group members 5 and 6 shown in Figure 3 ) corresponding to the group head b, the group head b service cell measurement result parameter measResultServCell (including the ID of the service cell and the values of RSRP and RSRQ thereof) and the neighbor cell measurement result parameter measResultNeighCell (including the IDs of all neighbor cells and the values of RSRP and RSRQ corresponding to each neighbor cell) are used to represent the measurement result parameters of all group member devices (the group members 5 and 6 shown in Figure 3 ) corresponding to the group head b.

[0097] Further, the source satellite A parses the first handover request message, encapsulates information such as the identity of the destination satellite B, the identity of the group, and the identity of the group member device into a satellite message (i.e., the second handover request message described above), and sends the satellite message to the gateway station. Then, the gateway station generates a handover demand message (i.e., the third handover request message described above) according to the satellite message, and sends the handover demand message to the destination satellite B to notify the destination satellite B to prepare corresponding communication resources.

[0098] Further, the destination satellite B performs admission control according to the current load condition and the number of group member devices to determine whether to receive the user device. When the destination satellite B confirms to receive the user device, the destination satellite B allocates corresponding wireless channel resources and access information to all user devices, generates a response message (i.e., the first handover response message described above) corresponding to the handover demand message, and sends the response message to the gateway station.

[0099] Further, the gateway station confirms that the destination satellite B has prepared for handover after receiving the response message to the handover request, and forwards the response message to the handover request (i.e., the second handover response message described above) to the source satellite A. The source satellite A parses the response message to the handover request and generates a group leader handover command message (i.e., the third handover response message described above), and then sends the group leader handover command message to the group leader b. Thus, the group leader b switches from the source satellite A to the destination satellite B in the RACH handover mode according to the group leader handover command message. Further, when the group leader b completes the handover, the group leader b sends a handover command message (i.e., the fourth handover response message described above) to the group members 5 and 6. Thus, the group member devices switch from the source satellite A to the destination satellite B in the RACH-less handover mode according to the fourth handover response message.

[0100] In the technical solution provided by the application, the uplink grant message (UL grant) is the dedicated wireless resource information required by the group member device. The source satellite can send the UL grant to each group member device in the group separately. When a certain group member device cannot obtain the UL grant from the source satellite, the group member device can obtain the UL grant information by listening to the PDCCH of the destination satellite. It can also be understood that the group member device can obtain the UL grant information according to the preconfigured fixed PDCCH physical channel in the group member handover command, or can obtain the UL grant information in the full-band search mode.

[0101] It should be further explained that, considering that part of the parameters in the RRC reconfiguration information issued by the source satellite to the user equipment in the same group are the same, such as DownlinkConfigCommon, UplinkConfigCommon, t304, SMTC in ServingCellConfigCommon, therefore, after the source satellite sends the RRC reconfiguration message to the group head device, the group head device broadcasts part of the same information in the RRC reconfiguration information to each group member device. It should be noted that during the SMTC period, the UE will perform wireless link monitoring (or wireless resource management measurement) on the configured SSB or CSI-RS for the satellite ephemeris data of the target satellite. It can also be understood that, in the case that the group head device and the group member device are both equipped with a wireless network card, the mutual communication between the group head device and the group member device can be realized by setting the same SSID information, the same channel information, etc.

[0102] It can also be understood that the communication network between the group head device and the group member device has the following characteristics:

[0103] (1) In this network structure, there is no fixed center, which can quickly organize and build network nodes, and the information transmission mode between the group head device and the group member device (such as single-hop communication mode, multi-hop communication mode) can also be set according to the actual scene;

[0104] (2) In this network, each network node can obtain its own position information, and each network node in the network can periodically broadcast messages and also receive messages broadcast by neighbor nodes to obtain the position information of neighbor nodes. For neighbor nodes, different broadcast times can be set to avoid mutual interference between nodes.

[0105] It should be further explained that the fields of the message broadcast by the neighbor node can be as shown in Table 1 below:

[0106] Table 1

[0107]

[0108]

[0109] When a node receives the message from a neighbor node as shown in Table 1 above, the source node identifier of the node and the position information of the node (including the horizontal coordinate of the node and the vertical coordinate of the node) are updated to the neighbor table. The structure of the updated neighbor table can be as shown in Table 2 below:

[0110] Table 2

[0111] Field name Field description neigh_id Neighboring node identification pos_x Horizontal coordinate of the node pos_y Vertical coordinate of the node timestap Recording time of the node position data

[0112] Further need to be explained is that when the current node does not receive the message shown in Table 1 of the above other node in the neighbor table within a period of time, it is judged that the other node has been unable 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.

[0113] It can be further understood that when the group head device and the group member device communicate in a multi-hop communication mode, in order to ensure that each group member device can receive the switching command message sent by the group head device within a short time, the maximum value of the hop number of each node to the group head device can be set. In addition, in order to control the running time of the algorithm, the Dijkstra algorithm can be used to solve the shortest path problem.

[0114] In the above optional embodiment, the technical effects that can be achieved are that the group head device can communicate with the group member device in any one of a plurality of communication modes to send the group member switching command message to the group member device, thereby reducing the signaling overhead in the switching communication satellite process and improving the data transmission efficiency.

[0115] In an optional embodiment, the above switching communication satellite method further comprises:

[0116] Step S131, in response to the existence of communication satellite switching demand of at least two groups at the same time, priority analysis is performed on at least two group head devices corresponding to the at least two groups to obtain a priority sorting result;

[0117] Step S132, according to the priority sorting result, the at least two group head devices are controlled to be switched from the source satellite to the target satellite in turn according to the RACH switching mode.

[0118] In the technical scheme provided by the present application, for a plurality of groups in the coverage area of the same satellite, after grouping and group head selection, the priority of each group head device can be calculated according to the signal strength of the target satellite B measured by each group head device, the number of group members, the application category of each group member device and other parameter information. It can be understood that generally, the priority of the group member device with voice, video and other application requirements is higher than that of the group member device with audio, image and other application requirements, so the priority of each group head device can be calculated based on the analytic hierarchy process, and the priorities of all group head devices in the coverage area of the same satellite are sorted. When a plurality of groups exist switching demand at the same time, the group head device in the group with higher priority is switched first, and in addition, for other groups, whether to switch the communication satellite from the source satellite to the target satellite can be determined based on the traffic balance constraint of the target satellite.

[0119] In the optional embodiment, the technical effects achieved are that when the group leader devices of multiple groups in the coverage area of the same satellite simultaneously send switching requests to the source satellite, the group leader devices in each area are prioritized, so that when multiple group leader devices simultaneously send switching requests, the group leader devices with higher priorities are preferentially switched, thereby solving the problem of large signaling consumption caused by simultaneous switching of multiple group leader devices, and reducing switching delay, improving switching efficiency and success rate.

[0120] According to another aspect of the embodiments of the present application, a method for switching communication satellites is also provided, which is applied to a group leader device of a group, the group being obtained by grouping a plurality of user devices, the plurality of user devices being located in the coverage area of a source satellite and being in communication connection with the source satellite, when a switching condition is met, the method comprises:

[0121] In step S21, the group leader device is switched from the source satellite to the target satellite according to the RACH switching mode, and the group member devices are triggered to be switched from the source satellite to the target satellite according to the RACH-less switching mode, wherein the group member devices are other user devices in the group except the group leader device.

[0122] In the technical solution provided by the present application, the switching condition can include that 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 condition that 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 leader device in the group from the source satellite, the second signal strength is the signal strength of the satellite signal received by the group leader device in the group from the target 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 target satellite. When the switching condition is met, the group leader device sends a first switching request message to the source satellite, and the first switching request message can be used to request switching of the communication satellite from the source satellite to the target satellite.

[0123] When the switching condition is met, the group leader device switches from the source satellite to the target satellite in a RACH switching mode. The specific method can 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 target satellite, and the first switching request message includes a measurement identifier parameter corresponding to the group leader device and a measurement result parameter, the measurement identifier parameter being determined by the identifier of the group leader device and the identifier of the group member device, and the measurement result parameter being further used to determine the measurement result of the group member device; then, receiving a third switching response message returned by the source satellite, wherein the third switching response message is used to instruct the group leader device to switch to a communication connection with the target satellite; and finally, switching from the source satellite to the target satellite according to the third switching response message.

[0124] When the switching condition is met, the group member device triggers the group member device to switch from the source satellite to the target satellite in a RACH-less switching mode. The specific method can be: 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 target satellite in a RACH-less switching mode 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 offset information, and the synchronization offset information is used to determine the clock synchronization offset between the source satellite and the target satellite, and the uplink authorization information is sent by the source satellite to the group member device.

[0125] It should be noted that the above-mentioned synchronization offset information can be used to represent the difference in communication time between the source satellite and the target satellite to the user equipment. Specifically, when the synchronization offset information is not zero, it can represent that the communication time between the source satellite and the target satellite to the user equipment is different.

[0126] As shown in Figure 3 , 4 At the same time that the source satellite A sends the group leader switching command message to the group leader b, the source satellite A sends a group member dedicated signaling message to the group member devices 5 and 6 which are in the same group as the group leader b. Further, after the group leader b switches from the source satellite to the target satellite in a RACH switching mode according to the group leader switching command message, the group leader b sends a group member switching command message to the group member devices 5 and 6, and the group member switching command message includes at least synchronization offset information used to determine the clock synchronization offset between the source satellite and the target satellite.

[0127] In an optional embodiment, the above-mentioned satellite switching method further includes:

[0128] Step S231, obtaining a first time, a second time, a third time and a fourth time, wherein the first time is a time when the source satellite sends the first synchronization signal, the second time is a time when the group leader device receives the first synchronization signal, the third time is a time when the destination satellite sends the second synchronization signal, and the fourth time is a time when the group leader device receives the second synchronization signal;

[0129] Step S232, calculating a first propagation time of the first synchronization signal according to the first time and the second time, and calculating a second propagation time of the second synchronization signal according to the third time and the fourth time;

[0130] Step S233, calculating the synchronization deviation information by using the first propagation time and the second propagation time.

[0131] As shown in FIG. 6, Figure 3 , 4 When the group member devices 5 and 6 receive the group member switching command message sent by the group leader b, the group member switching command message is parsed to obtain the synchronization deviation information of the source satellite and the destination satellite, and further, the synchronization deviation information is calculated to obtain the timing advance information between the current group leader device and the destination satellite.

[0132] As shown in FIG. 6, Figure 3 , 4 As an optional implementation, the time when the source satellite A sends the synchronization signal is denoted as The propagation time of the synchronization signal sent by the source satellite A is denoted as T SRC The time when the synchronization signal sent by the source satellite A reaches the group leader b is denoted as The time when the destination satellite B sends the synchronization signal is denoted as The propagation time of the synchronization signal sent by the destination satellite B is denoted as T TGT The time when the synchronization signal sent by the destination satellite B reaches the group leader b is denoted as It can be understood that the time relationship of the synchronization signals sent by the source satellite A and the destination satellite B can be respectively shown in the following formulas (1) and (2):

[0133]

[0134]

[0135] Further, the synchronization deviation T DIFF between the source satellite A and the destination satellite B can be shown in the following formula (3):

[0136]

[0137] According to a further aspect of the embodiments of the present application, a method for switching a communication satellite is also provided, which is applied to a group member device of a group, the group is obtained by grouping a plurality of user devices, the group member device is a user device other than a group leader device in the group, the plurality of user devices are located in a coverage area of a source satellite and are in a communication connection with the source satellite, and the method comprises:

[0138] In step S31, the group member device is switched from the source satellite to the target satellite according to the RACH-less switching mode in response to the triggering of the group leader device, wherein the group leader device is switched from the source satellite to the target satellite according to the RACH switching mode.

[0139] In the technical solution provided by the present application, when the switching condition is met, the group member device sends a group member switching request message to the group leader device, and the group member switching request message is used to request to switch the communication satellite from the source satellite to the target satellite, wherein the switching condition comprises that a difference between the fourth signal strength and the third signal strength is greater than the second threshold value; wherein the third signal strength is a signal strength of a satellite signal received by the group member device from the source satellite, and the fourth signal strength is a signal strength of a satellite signal received by the group member device from the target satellite.

[0140] In an optional embodiment, in step S31, the group member device is switched from the source satellite to the target satellite according to the RACH-less switching mode in response to the triggering of the group leader device, which comprises:

[0141] In step S311, a group member switching command message sent by the group leader device is received, wherein information carried in the group member switching command message at least comprises synchronization deviation information, and the synchronization deviation information is used to determine a clock synchronization deviation between the source satellite and the target satellite.

[0142] In step S312, timing advance information is calculated according to the synchronization deviation information, wherein the timing advance information is used to represent a timing advance between the group member device and the target satellite.

[0143] In step S313, the group member device is switched from the source satellite to the target satellite according to the RACH-less switching mode based on uplink authorization information and the timing advance information, wherein the uplink authorization information is sent to the group member device by the source satellite.

[0144] As shown in the figure, in the technical solution provided by the present application, the timing advance of the group leader b to the source satellite A is twice the propagation time T SRC of the synchronization signal sent by the source satellite A, and the timing advance of the group leader b to the target satellite B is twice the propagation time T TGT of the synchronization signal sent by the target satellite B, and therefore, the timing advance TA DIFF of the group leader b to the target satellite B is calculated based on the synchronization deviation T TGT between the source satellite A and the target satellite B.TGT The formula (4) is shown as follows:

[0145]

[0146] As shown in Figure 3 , 4 After the group head device completes the switching of the communication satellite according to the RACH switching mode, the group member devices switch from the source satellite A to the target satellite B according to the RACH-less switching mode according to the received group member switching command message sent by the group head device, and after the switching is completed, the group member devices send a group member switching confirmation message to the target satellite B. Further, the target satellite B feeds back a switching completion message to the ground gateway station after determining that the group member devices have successfully switched to the satellite, and the switching completion message is further forwarded to the source satellite A by the gateway station to inform the source satellite A to release the communication resources (such as channel resources).

[0147] The above method is further described below. Figure 5 The above method is further described below.

[0148] Figure 5 is another optional flowchart of the switching process of the communication satellite according to an embodiment of the present application, as shown in Figure 5 When the source satellite and the target satellite do not have the above-mentioned synchronization deviation, the group head device and the group member devices in the group can calculate the above-mentioned timing advance information TA by the method shown in the formula (5) as follows: TGT :

[0149]

[0150] As shown in Figure 5 , further, the group head device and the group member devices can switch the communication satellite according to the RACH-less switching mode based on the timing advance information shown in the formula (5) and the above-mentioned uplink authorization information. Specifically, after the source satellite receives the switching request response message of the target satellite, the source satellite can simultaneously or at different times send corresponding group head switching command messages and group member dedicated signaling messages to the group head device and the group member devices. When the group head device and the group member devices complete the switching at the same time or at different times, the group head device and the group member devices can simultaneously or at different times send group head switching confirmation messages and group member switching confirmation messages to the target satellite.

[0151] In the optional embodiment, the technical effects achieved are that the group leader device and the group member device switch the communication satellite according to different switching times and different switching manners, thereby reducing the signaling consumption in the network, relieving the network congestion, effectively avoiding the switching interruption problem, and reducing the switching delay, improving the switching efficiency and success rate; in addition, according to the technical solution provided in the application, the group leader device and the group member device can execute different switching schemes of the communication satellite according to the synchronization deviation information of the source satellite and the target satellite, thereby improving the flexibility of the switching communication satellite method.

[0152] In the embodiment, a device for switching communication satellite is also provided, which is used to implement the above-mentioned embodiments and preferred embodiments, and will not be described again. As used below, a "module" is a combination of software and / or hardware that can implement a predetermined function. Although the device described in the following embodiments is preferably implemented in software, implementation of hardware, or a combination of software and hardware, is also possible and is contemplated.

[0153] Figure 6 is a structural block diagram of an optional device for switching communication satellite according to an embodiment of the application, as shown in Figure 6 The device comprises:

[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 connection with the source satellite, the grouping result comprises at least one group, and each group comprises at least one group leader device.

[0155] An execution module 602 is configured to, for each group, execute switching of a communication satellite of the group when a switching condition is met; wherein the switching of the communication satellite of the group comprises: the group leader device switches from the source satellite to a target satellite according to a RACH switching manner, and group member devices switch from the source satellite to the target satellite according to a RACH-less switching manner in response to triggering of the group leader device, wherein the group member devices are other user devices in the group except the group leader device.

[0156] Optionally, the grouping module 601 is further configured to group the plurality of user devices according to geographical positions of the plurality of user devices to obtain at least one group, wherein user devices in each group of the at least one group are located in a same cell; and for each group of the at least one group, determine a target user device from the user devices in the current group as a group leader device corresponding to the current group.

[0157] Optionally, the grouping module 601 is further configured to: determine 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 a distance between each user equipment in the current group and a region center corresponding to the current group, wherein the region center is a geographic center of locations of all user equipment in the current group; and determine the target user equipment according to a received signal strength of each user equipment in the current group.

[0158] Optionally, the network side comprises a source satellite, a target satellite and a gateway station, and the execution module 602 is further configured to: receive, by the source satellite, the first handover request message sent by the group leader device, and send, by the source satellite, a second handover request message to the gateway station based on the first handover request message, wherein the first handover request message comprises the measurement identifier parameter and the measurement result parameter corresponding to the group leader device, and the second handover request message comprises the identifier of the target satellite, the identifier of the group, the identifier of the group leader device and the identifier of the group member device, the measurement identifier parameter is determined by the identifier of the group leader device and the identifier of the group member device, and the measurement result parameter is further used to determine the measurement result of the group member device; send, by the gateway station, a third handover request message to the target satellite based on the second handover request message, receive the first handover response message returned by the target satellite, and return the second handover response message to the source satellite, wherein the third handover request message is used to represent the handover requirement of the group leader device, the first handover response message comprises the admission information corresponding to the group leader device and the uplink authorization information corresponding to the group member device, and the second handover response message at least comprises the uplink authorization information, the admission information is determined by the current load of the target satellite and the number of the group member devices corresponding to the group leader device, and the uplink authorization information is used to support the group member devices corresponding to the group leader device to perform satellite handover in the RACH-less handover mode; send, by the source satellite, a third handover response message to the group leader device and a fourth handover response message to the group member device according to the second handover response message, wherein the fourth handover response message at least comprises the uplink authorization information, the third handover response message is used to switch the group leader device from the source satellite to the target satellite in the RACH handover mode, and the uplink authorization information is used to switch the group member device from the source satellite to the target satellite in the RACH-less handover mode; and / or the handover condition comprises that 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 satisfy the condition that 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 leader device in the group from the source satellite, the second signal strength is the signal strength of the satellite signal received by the group leader device in the group from the target 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 target satellite; and / or in response to the simultaneous existence of the satellite handover requirement of at least two groups, priority analysis is performed on at least two group leader devices corresponding to the at least two groups to obtain a priority sorting result; and the at least two group leader devices are controlled to be switched from the source satellite to the target satellite in the RACH handover mode in turn according to the priority sorting result.

[0159] According to a further aspect of the embodiments of the present application, a communication network device is also provided, comprising: a memory storing an executable program; and a processor configured to execute the program, wherein the program, when executed, performs the method for switching communication satellites of any preceding embodiment.

[0160] Optionally, in the embodiment, the processor can be configured to execute the program for performing the following steps:

[0161] Step S1, performing grouping 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, and the grouping result comprises at least one group, and each group comprises at least one group leader device;

[0162] Step S2, for each group, performing switching of a communication satellite of the group when a switching condition is met; wherein the switching of the communication satellite of the group comprises: switching, by the group leader device, from the source satellite to a target satellite according to a RACH switching mode, and switching, by a group member device, from the source satellite to the target satellite according to a RACH-less switching mode in response to triggering by the group leader device, wherein the group member device is a user device other than the group leader device in the group.

[0163] According to a further aspect of the embodiments of the present application, a computer readable storage medium is also provided, the storage medium comprising a stored program, wherein the program, when executed, controls a device in which the storage medium is located to perform the method for switching communication satellites of any preceding embodiment.

[0164] Optionally, in the embodiment, the computer readable storage medium can include, but is not limited to, a U disk, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and various storage media that can store programs.

[0165] Optionally, in the embodiment, the computer readable storage medium can be configured to store the program for performing the following steps:

[0166] Step S1, performing grouping 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, and the grouping result comprises at least one group, and each group comprises at least one group leader device;

[0167] Step S2, for each group, when the switching condition is met, performing switching of the communication satellite of the group; wherein the switching of the communication satellite of the group comprises: the group leader device switches from the source satellite to the target satellite according to the RACH switching mode, and the group member device switches from the source satellite to the target satellite according to the RACH-less switching mode in response to the triggering of the group leader device, wherein the group member device is a user equipment other than the group leader device in the group.

[0168] Optionally, specific examples in the embodiment can refer to the examples described in the above embodiments and optional implementation manners thereof, which will not be repeated here.

[0169] The serial numbers of the above embodiments of the application are only for description, and do not represent the advantages and disadvantages of the embodiments.

[0170] In the above embodiments of the application, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0171] In the several embodiments of the present application, it should be understood that the disclosed technology can be implemented in other ways. Of course, the unit embodiment described above is only schematic. For example, the division of the units can be a logical function division, and there can be another division manner in actual implementation, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection between each described or discussed unit can be indirect coupling or communication connection through some interface, unit or module, and can be electrical or other form.

[0172] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on multiple units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0173] In addition, each functional unit in each embodiment of the application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of software functional unit.

[0174] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application, essentially or in other words, the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, including a number of instructions to make a computer device (which can be a personal computer, a server or a network device, etc.) execute all or part of the steps of the methods described in various embodiments of the present application. The aforementioned storage medium includes: a U disk, a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store program codes.

[0175] The above is only the preferred embodiment of the present application, it should be pointed out that, for those skilled in the art, without departing from the principles of the present application, can make a number of improvements and refinements, these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A method for switching communication satellites, characterized in that: The method is applied to the network side, and the method includes: 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 mode, and the group member devices, in response to the triggering of the group head device, 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; The switching condition includes: more than a preset number of group member devices in the group satisfying the following condition: a difference between a fourth signal strength and a third signal strength is greater than a second threshold; wherein the third signal strength is a signal strength of a satellite signal received by the group member device from the source satellite, and the fourth signal strength is a signal strength of a satellite signal received by the group member device from the destination satellite; The group member device switches from the source satellite to the destination satellite in a RACH-less switching manner in response to the triggering of the group head device, including: the group head device sends 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 the 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.

2. The method according to claim 1, characterized in that Perform grouping processing on multiple user devices, and obtain the grouping results including: 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 of 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, characterized in that For each of 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; Determining the target user equipment based on the distance between each user equipment in the current group and a regional center corresponding to the current group, wherein the regional center is the geographic 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 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, and 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 the 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 a measurement result of the group member device; 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: admission 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 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 handover according to the RACH-less handover method; The source satellite sends a third handover response message to the group head device and a fourth handover response message to the group member device according to the second handover response message, wherein the fourth handover response message includes at least the uplink authorization information, the third handover response message is used by the group head device to switch from the source satellite to the destination satellite according to the RACH handover mode, 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 handover mode; And / or, the switching condition further includes: a difference between the second signal strength and the first signal strength is greater than a first threshold, wherein the first signal strength is a signal strength of a satellite signal received by a group head device in the group from the source satellite, and the second signal strength is a signal strength of a satellite signal received by the group head device in the group from a target satellite to be switched; And / or, the method further comprises: In response to at least two groups having communication satellite handover 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 cluster head devices are controlled to switch from the source satellite to the destination satellite in sequence according to the RACH switching manner.

5. A method for switching communication satellites, characterized in that: The method is applied to a group head device of a group, where the group is 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. When a handover condition is met, the method includes: The group head device switches from the source satellite to the destination satellite according to the RACH switching mode, and the group member devices, in response to the triggering of the group head device, 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; Among them, triggering the group member device to switch from the source satellite to the destination satellite according to the RACH-less switching method includes: 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 according to the RACH-less switching method 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.

6. The method according to claim 5, characterized in that 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 switching the communication satellite from the source satellite to the destination satellite; The switching condition includes: a 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 condition: a 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 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; And / or, switching from the source satellite to the destination satellite according to the RACH switching manner includes: sending a first handover request message to the source satellite through a random access channel, wherein the first handover request message is used to request handover to establish a communication connection with the destination satellite, and the first handover request message includes: a measurement identification parameter and a measurement result parameter corresponding to the group head device, the measurement identification parameter being determined by an identifier of the group head device and an identifier of the group member device, and the measurement result parameter being further used to determine a measurement result of the group member device; receiving a third handover response message returned by the source satellite, wherein the third handover response message is used to instruct the cluster head device to switch to a communication connection with the destination satellite; Switching from the source satellite to the destination satellite according to the third switching response message.

7. The method according to claim 5, characterized in that The method further comprises: 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; 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; The synchronization deviation information is calculated using the first propagation time and the second propagation time.

8. A method for switching communication satellites, characterized in that: The method is applied to group member devices of a group, where the group is obtained by grouping a plurality of user devices, the group member devices being other user devices in the group except a group leader device, the plurality of user devices being located in a coverage area of ​​a source satellite and being communicatively connected to the source satellite, and the method comprising: In response to a trigger of the cluster head device, switching from the source satellite to the destination satellite according to a RACH-less switching manner, wherein the cluster head device switches from the source satellite to the destination satellite according to a RACH switching manner; Switching from the source satellite to the destination satellite in a RACH-less switching manner in response to the triggering of the group head device includes: receiving a group member switching command message sent by the group head device, and switching from the source satellite to the destination satellite in the 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 devices.

9. The method according to claim 8, characterized in that The method further includes: when a switching condition is met, the group member device sending a group member switching request message to the group head device, wherein the group member switching request message is used to request switching 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; And / or, 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: Timing advance information is calculated according to the synchronization deviation information, wherein the timing advance information is used to represent the timing advance between the group member device and the destination satellite.

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