Cell switching method and device under satellite-ground fusion networking

Abstract

The invention provides a cell switching method and device under satellite-ground fusion networking, and relates to the technical field of mobile communication, and the method comprises the steps: determining a current switching scene of a current terminal and a switching decision point corresponding to the current switching scene based on a signal measurement report of the current terminal; determining a target cell of the current terminal based on the current switching scene and the switching decision point; switching the current terminal from a source cell to the target cell; wherein the switching scene comprises switching from the ground cell to the ground cell, switching from the ground cell to the satellite cell, switching from the satellite cell to the satellite cell and switching from the satellite cell to the ground cell. According to the method and the device provided by the invention, the cell switching efficiency can be improved in a large-scale user and complex network environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mobile communication, and in particular to a cell switching method and device in a satellite-terrestrial integrated network. BACKGROUND

[0002] With the rapid development and deployment of ground mobile networks and satellite communication technologies, a satellite-terrestrial integrated network (STIN) has the advantage of wide coverage and can meet the communication needs of remote areas and make up for the deficiencies of ground networks.

[0003] The cell switching method in the related art is only compatible with two switching situations: switching from a satellite cell to a ground cell and switching from a ground cell to a satellite cell. In the case of a large-scale user scenario and a complex network environment caused by frequent changes in satellite-terrestrial link connections, the switching efficiency is low and cannot meet the actual needs of mobile communication networks.

[0004] Therefore, how to improve the efficiency of cell switching in a large-scale user and a complex network environment has become a technical problem to be solved in the industry. SUMMARY

[0005] The present application provides a cell switching method and device in a satellite-terrestrial integrated network, which is used to solve the technical problem of how to improve the efficiency of cell switching in a large-scale user and a complex network environment.

[0006] The present application provides a cell switching method in a satellite-terrestrial integrated network, comprising: determining a current switching scenario of a current terminal and a switching decision point corresponding to the current switching scenario based on a signal measurement report of the current terminal; determining a target cell of the current terminal based on the current switching scenario and the switching decision point; switching the current terminal from a source cell to the target cell; wherein the switching scenario includes switching from a ground cell to a ground cell, switching from a ground cell to a satellite cell, switching from a satellite cell to a satellite cell, and switching from a satellite cell to a ground cell.

[0007] In some embodiments, the determining of the current switching scenario of the current terminal and the switching decision point corresponding to the current switching scenario based on the signal measurement report of the current terminal comprises: determining, based on the signal measurement report, that the current switching scenario of the current terminal is conditional switching, and determining that the switching decision point corresponding to the current switching scenario is the current terminal; Alternatively, based on the signal measurement report, it is determined that the source cell where the current terminal is located is a ground cell and the current handover scenario is handover from a ground cell to a satellite cell; and it is determined that the handover decision point corresponding to the current handover scenario is a core network of the source cell. Alternatively, based on the signal measurement report, it is determined that the source cell where the current terminal is located is a ground cell and the current handover scenario is handover from a ground cell to a ground cell; and it is determined that the handover decision point corresponding to the current handover scenario is a source node in the source cell. Alternatively, based on the signal measurement report, it is determined that the source cell where the current terminal is located is a satellite cell and the current handover scenario is handover from a satellite cell to a ground cell; and it is determined that the handover decision point corresponding to the current handover scenario is a core network of the source cell. Alternatively, based on the signal measurement report, it is determined that the source cell where the current terminal is located is a satellite cell and the current handover scenario is handover from a satellite cell to a satellite cell; and it is determined that the handover decision point corresponding to the current handover scenario is a core network of the source cell or a source node in the source cell.

[0008] In some embodiments, in a case where the current handover scenario is conditional handover, the switching the current terminal from the source cell to the target cell comprises: determining that the current terminal meets a first execution condition; determining that a handover trigger duration is greater than a preset trigger duration; determining that the current terminal meets a second execution condition; switching the current terminal from the source cell to the target cell; the first execution condition comprises that, in a case where the source cell is a satellite cell, an elevation angle between the current terminal and a satellite is less than a preset elevation angle threshold, or in a case where the source cell is a ground cell, a signal-to-noise ratio in the signal measurement report is less than a preset signal-to-noise ratio threshold; the second execution condition comprises that a signal quality of the target cell is better than a signal quality of the source cell.

[0009] In some embodiments, the second execution condition comprises: in a case where the source cell and the target cell are both satellite cells, based on an elevation angle between the current terminal and a satellite corresponding to the source cell and an elevation angle between the current terminal and a satellite corresponding to the target cell, it is determined that the signal quality of the target cell is better than the signal quality of the source cell. In a case where the source cell and the target cell are both ground cells, determining that the signal quality of the target cell is superior to the signal quality of the source cell based on a signal-to-noise ratio in a signal measurement report of the current terminal in the source cell and a signal-to-noise ratio in a signal measurement report of the current terminal in the target cell. In a case where the source cell is a ground cell and the target cell is a satellite cell, determining that the signal quality of the target cell is superior to the signal quality of the source cell based on a signal-to-noise ratio in a signal measurement report of the current terminal in the source cell and an elevation angle between the current terminal and a satellite corresponding to the target cell. In a case where the source cell is a satellite cell and the target cell is a ground cell, determining that the signal quality of the target cell is superior to the signal quality of the source cell based on an elevation angle between the current terminal and a satellite corresponding to the source cell and a signal-to-noise ratio in a signal measurement report of the current terminal in the target cell.

[0010] In some embodiments, in a case where the current handover scenario is a conditional handover, the determining of the target cell of the current terminal based on the current handover scenario and the handover decision point comprises: determining a plurality of terminals and a plurality of cells; the plurality of terminals comprises the current terminal, and the plurality of cells comprises a plurality of satellite cells and a plurality of ground cells; clustering the plurality of terminals based on position information, speed information and bandwidth demand of each terminal to determine a plurality of terminal groups; determining an optimization target based on at least one of network throughput, network handover delay, load balancing degree and terminal speed reward value of each cell; determining a restriction condition based on at least one of network coverage, network service capacity, network load capacity and network handover delay of each cell; determining the target cell corresponding to each terminal group based on the optimization target and the restriction condition by using a genetic algorithm; determining the target cell corresponding to the terminal group in which the current terminal is located as the target cell of the current terminal.

[0011] In some embodiments, the determining of the optimization target based on at least one of network throughput, network handover delay, load balancing degree and terminal speed reward value of each cell comprises: determining the network throughput of each cell based on signal receiving power, noise power of each cell and a connection relationship between each cell and each terminal; determining the network handover delay of each cell based on the network handover delay between each terminal and each cell and the connection relationship between each cell and each terminal. The load balance of each cell is determined based on the number of terminals currently connected to each cell and the maximum number of terminals allowed to connect to each cell. Based on the mobile speed of each terminal and the connection relationship between each cell and each terminal, the terminal speed reward value of each cell is determined. The optimization objective is determined based on the network throughput, network handover latency, load balancing, and terminal speed reward value of each cell.

[0012] In some embodiments, determining the limiting conditions based on at least one of the network coverage, network service capacity, network load capacity, and network handover latency of each cell includes: Based on the network coverage of each cell and the connection relationship between each cell and each terminal, the first constraint condition is determined. The second constraint is determined based on the terminal data transmission rate of each cell and the maximum service capacity of each cell. The third constraint is determined based on the maximum number of terminal connections in each cell and the connection relationship between each cell and each terminal. Based on the network handover latency of each cell and the preset network handover latency threshold, the fourth constraint condition is determined.

[0013] This application provides a cell handover device under a satellite-ground integrated network, comprising: The handover decision module is used to determine the current handover scenario of the current terminal and the handover decision point corresponding to the current handover scenario based on the signal measurement report of the current terminal. The cell determination module is used to determine the target cell of the current terminal based on the current handover scenario and the handover decision point; The cell handover module is used to hand over the current terminal from the source cell to the target cell; The handover scenarios include handover from terrestrial cell to terrestrial cell, handover from terrestrial cell to satellite cell, handover from satellite cell to satellite cell, and handover from satellite cell to terrestrial cell.

[0014] This application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the cell handover method under the satellite-ground integrated networking.

[0015] This application provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the cell handover method under the satellite-ground integrated networking.

[0016] The cell handover method and apparatus provided in this application for satellite-ground integrated networking determine the current handover scenario and the corresponding handover decision point of the current terminal based on the signal measurement report of the current terminal; determine the target cell of the current terminal based on the current handover scenario and the handover decision point; and hand over the current terminal from the source cell to the target cell. Since the handover scenarios include handover from terrestrial cell to terrestrial cell, handover from terrestrial cell to satellite cell, handover from satellite cell to satellite cell, and handover from satellite cell to terrestrial cell, the handover scenarios under satellite-ground integrated networking are diversified, which can maximize the mobility in the communication scenario, improve the efficiency of cell handover in large-scale user and complex network environments, and can cope with multiple handover scenarios, thus meeting the actual needs in mobile communication networks. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0018] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart illustrating the cell handover method under the satellite-ground integrated networking provided in this application.

[0020] Figure 2 This is a schematic diagram of the satellite-ground integrated communication provided in this application.

[0021] Figure 3 This is a flowchart of the switching process for the satellite-ground integrated networking provided in this application.

[0022] Figure 4 This is a flowchart of the decision-making process for switching decision points provided in this application.

[0023] Figure 5 This is a diagram of the switching trigger process for the condition switching provided in this application.

[0024] Figure 6 This is a flowchart illustrating the clustering algorithm provided in this application.

[0025] Figure 7 This is a flowchart illustrating the genetic algorithm provided in this application.

[0026] Figure 8 This is a structural schematic diagram of the cell handover device under the satellite-ground integrated networking provided in this application.

[0027] Figure 9 This is a schematic diagram of the structure of the electronic device provided in this application. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0029] It should be noted that the terms "first," "second," etc., used in this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that comprises a series of steps, units, or modules is not necessarily limited to those explicitly listed, but may include other steps, units, or modules not explicitly listed or inherent to such processes, methods, products, or devices.

[0030] In the technical solution of this application, the collection, storage, use, processing, transmission, provision and disclosure of personal information all comply with the provisions of relevant laws and regulations, necessary confidentiality measures have been taken, and they do not violate public order and good morals.

[0031] Current cell handover methods in related technologies only support two handover scenarios in satellite-terrestrial integrated networks: handover from a satellite cell to a terrestrial cell, and handover from a terrestrial cell to a satellite cell. This approach only addresses a limited range of handover scenarios and is not comprehensive enough. It fails to consider handover between terrestrial cells and between satellite cells. Only by integrating all four handover scenarios can seamless handover in satellite-terrestrial integrated networks be achieved more comprehensively. Currently, cell handover decisions for all scenarios are made by the Application Management Function (AMF) in the core network, leading to an excessive decision-making load on the AMF and impacting handover efficiency.

[0032] Furthermore, the cell handover methods in related technologies also have shortcomings, such as not considering the large number of handovers caused by frequent changes in satellite-to-ground link connections in large-scale user scenarios; not considering optimization of handover success rate; not comprehensively handling handover latency, not considering the waiting time for users from handover failure to re-establish connection when there are too many users, congestion or handover failure, and not considering the specific handover process, which may involve multiple round trips from the base station to the user.

[0033] In order to address the shortcomings of related technologies, Figure 1 This is a flowchart illustrating the cell handover method under the satellite-ground integrated networking provided in this application, as follows: Figure 1 As shown, the method includes steps 110, 120 and 130.

[0034] Step 110: Based on the signal measurement report of the current terminal, determine the current handover scenario of the current terminal and the handover decision point corresponding to the current handover scenario; wherein, the handover scenario includes handover from terrestrial cell to terrestrial cell, handover from terrestrial cell to satellite cell, handover from satellite cell to satellite cell, and handover from satellite cell to terrestrial cell.

[0035] Specifically, Figure 2 This is a schematic diagram of the satellite-ground integrated communication provided in this application, as shown below. Figure 2 As shown, the terminal, also known as user equipment (UE), can access the network through terrestrial base stations or low-Earth orbit (LEO) satellites. These two access methods allow the terminal to switch between their coverage areas, ensuring communication continuity and reliability. The terminal can directly access the network through the coverage area of ​​a terrestrial base station or through the coverage area of ​​a satellite's signal beam. Satellites can also interconnect via inter-satellite links, improving network redundancy and flexibility. UE1, UE2, and UE3 are terminals; LEO1 and LEO2 are satellites; and BS1, BS2, BS3, and BS4 are terrestrial base stations.

[0036] A cell, also known as a cellular cell, refers to the area covered by one base station or part of a base station (fan antenna) in a cellular mobile communication system, within which mobile stations can reliably communicate with the base station via a wireless channel.

[0037] The current terminal refers to the terminal that needs to undergo cell handover. The current terminal can be located in a terrestrial cell covered by a base station, a satellite cell covered by a satellite, or an area covered by both. When the terminal moves, or moves with the satellite, the current terminal will switch to a cell with better communication. For example, if the signal of a terrestrial base station weakens while a terminal is moving, the system can switch the connection to a satellite link or another terrestrial base station to maintain connection stability and quality. Similarly, if a satellite's position changes, causing its signal to weaken, the terminal can switch back to a terrestrial base station or switch to another satellite for communication.

[0038] The handover scenarios include handover from terrestrial cell to terrestrial cell (terrestrial-to-terrestrial, for example, UE1 handovers between terrestrial cells between BS1, BS2 and BS4), handover from terrestrial cell to satellite cell (terrestrial-to-satellite, for example, UE3 handovers from terrestrial cell to satellite cell between BS3 and LEO1), handover from satellite cell to satellite cell (satellite-to-satellite, for example, UE2 handovers between satellite cells between LEO1 and LEO2), and handover from satellite cell to terrestrial cell (satellite-to-terrestrial, for example, UE3 handovers from satellite cell to terrestrial cell between BS3 and LEO1).

[0039] A handover decision point refers to the device or system that decides whether to perform a cell handover for the current terminal. In the embodiments of this application, the handover decision point may include the current terminal, the source node of the source cell where the current terminal is located, and the core network corresponding to the source node. Different handover decision points are required for different handover scenarios. In particular, for satellite-to-ground handover, the core network needs to make the handover decision, which can be implemented by the AMF service in the core network.

[0040] In this embodiment, the source cell refers to the cell where the current terminal was located before the cell handover, including a terrestrial cell or a satellite cell; the source node refers to the base station to which the current terminal was connected before the cell handover, including a terrestrial base station or a satellite base station. The target cell refers to the cell where the current terminal is located after the cell handover, including a terrestrial cell or a satellite cell; the target node refers to the base station to which the current terminal is connected after the cell handover, including a terrestrial base station or a satellite base station.

[0041] The signal measurement report contains data used to evaluate the quality and performance of wireless signals in a mobile communication network. Based on the current terminal's signal measurement report, the current handover scenario and the corresponding handover decision point for that scenario are determined.

[0042] Step 120: Based on the current handover scenario and handover decision point, determine the target cell for the current terminal.

[0043] Specifically, the target cell for the current terminal can be determined based on the current handover scenario and the handover decision point. For example, if the handover decision point is the current terminal, and the current handover scenario is a conditional handover (CHO), the current terminal can select the cell with the best signal quality as the target cell based on the signal quality of each cell.

[0044] Step 130: Switch the current terminal from the source cell to the target cell.

[0045] Specifically, after the target cell is determined, the source node of the source cell can send a handover request to the target node of the target cell. The target node determines the handover response based on the handover request and sends the handover response to the source node, thereby enabling the current terminal to be switched from the source cell to the target cell.

[0046] Figure 3 This is a flowchart of the handover process for the satellite-ground integrated networking provided in this application, such as... Figure 3 As shown, the switching process includes: Step 1. The terminal performs relevant measurements and sends a measurement report according to the measurement control of the source node: When the terminal detects a change in network conditions, such as a decrease in signal strength, the terminal uses built-in measurement tools and algorithms within the current serving cell to perform measurements according to the measurement control instructions provided by the source node, and reports to the source node through the wireless link.

[0047] Choose one of the following four decision points as the current switching decision point: Switch decision point 1 (used for ground-to-ground and star-to-star switching). Step 2a. The source node decides whether to perform a handover between ground cells or between satellite cells. Here, we consider the case where there is an XN interface between the base stations, but no XN interface exists between the satellite base station and the ground base station. Step 3a. The source node sends a handover request to the target node; Step 4a. The target node performs access control, verifies the terminal's identity, and prepares to switch resources; Step 5a. The target node sends a handover request confirmation to the source node; Switch decision point 2 (used for star-to-star and ground-to-ground switching). When a terminal makes a handover decision and selects a target cell, the source node directly encapsulates the decision information and forwards it to the target node.

[0048] Switch decision point 3 (used for star-to-ground, ground-to-star, star-to-star transitions). Step 1b. After determining that the decision was not its responsibility, the source node forwards the measurement information to the source AMF (the source core network's AMF service). Step 2b. The source AMF makes a handover decision and determines the target cell; Step 3b. The source AMF sends a handover request to the target node; Step 4b. The target node performs access control, verifies the terminal's identity, and prepares to switch resources; Step 5b. The target node sends a handover request confirmation to the source AMF node; Step 6b. The source AMF node sends a switchover command to the source node; Step 6. The source node sends a switch command to the terminal.

[0049] Switch decision point 4 (used for ground-to-ground and star-to-star switching). When a Condition Handover (CHO) is performed, the terminal sends an RRC (Radio Resource Control) reconfiguration completion message to the source node. Additionally, the terminal needs to monitor candidate target satellite cells or target ground cells and select the final target cell. It's important to note that this implements the execution phase of the CHO. The preparation phase requires decision point 1 or 3 to prepare multiple candidate target nodes when the link status is relatively stable, and these candidate target nodes should be ready for the handover.

[0050] Step 7. Disconnect from the source cell and synchronize to the new cell. This process can be achieved through random access. Specifically, the terminal initiates a random access request to the target cell through the target node, sending a preamble on the allocated random access time-frequency resources. Subsequently, the target node sends a random access response to the terminal, including the Cell-Radio Network Temporary Identifier (C-RNTI), timing advance, frequency offset information, etc.

[0051] Step 7a. During the Dual Active Protocol Stack (DAPS) switching process, the source node sends an SN STATUS TRANSFER message to the target node to obtain the data order, so that the terminal can forward the data correctly after establishing a connection with the source node.

[0052] Step 7b. In the case of CHO, the data status information will be forwarded to the target node first, and subsequent data forwarding preparation operations will be performed after the switchover is completed.

[0053] Step 8. Switching complete. At this point, the terminal will send an RRC reconfiguration complete message to the target node, and the terminal will release the previously configured CHO information.

[0054] Step 8.1 is that after the switch is completed in CHO, the source node will be notified, and then in step 8.2 the source node will forward the data order and other information to the target node, ensuring the continuity and integrity of the data.

[0055] Step 9. Path Switching Request The target node sends a path switching request to the source AMF, and the switching state transitions.

[0056] Step 10. Path Switching There are two scenarios: (1) If the source node and the target node belong to the same AMF, the source AMF will perform path switching and position update; (2) If the source node and the target node do not belong to the same AMF, the source AMF and the target AMF will perform path switching and position update.

[0057] Step 11. Path Switching Request Response The source AMF sends a path switching request response to the target node.

[0058] Step 12. Resource Release The target node sends a resource release request to the source node to release the terminal context.

[0059] Step 13. The source node releases resources.

[0060] The above process ensures a smooth handover when a terminal needs to switch between terrestrial and satellite networks or between networks of the same type, while maintaining uninterrupted communication. This process encompasses terminal measurement, handover decision-making, request, resource preparation, and release, ensuring effective management of network resources and continuity of terminal services. This design allows the network to adapt to constantly changing environments and user needs, ensuring quality of service under various network conditions and user behaviors, especially in areas where traditional terrestrial base stations cannot provide coverage. This process reflects the complex synergy between and within different types of networks, ensuring quality of service for users under diverse network conditions.

[0061] The cell handover method under the satellite-ground integrated networking provided in this application embodiment determines the current handover scenario and the corresponding handover decision point of the current terminal based on the signal measurement report of the current terminal; determines the target cell of the current terminal based on the current handover scenario and the handover decision point; and hands over the current terminal from the source cell to the target cell. Since the handover scenarios include handover from terrestrial cell to terrestrial cell, handover from terrestrial cell to satellite cell, handover from satellite cell to satellite cell, and handover from satellite cell to terrestrial cell, it realizes the diversification of handover scenarios under the satellite-ground integrated networking, can maximize the mobility in the communication scenario, can improve the efficiency of cell handover in large-scale user and complex network environments, and can cope with multiple handover scenarios, meeting the actual needs in mobile communication networks.

[0062] It should be noted that each implementation method of this application can be freely combined, rearranged, or executed individually, and does not need to rely on or depend on a fixed execution order.

[0063] In some embodiments, based on the signal measurement report of the current terminal, the current handover scenario of the current terminal and the handover decision point corresponding to the current handover scenario are determined, including: Based on the signal measurement report, the current handover scenario of the current terminal is determined to be conditional handover, and the handover decision point corresponding to the current handover scenario is determined to be the current terminal; Alternatively, based on the signal measurement report, determine that the source cell of the current terminal is a terrestrial cell and the current handover scenario is a handover from a terrestrial cell to a satellite cell; determine that the handover decision point corresponding to the current handover scenario is the core network of the source cell; Alternatively, based on the signal measurement report, determine that the source cell where the current terminal is located is a terrestrial cell and the current handover scenario is a handover from one terrestrial cell to another; determine that the handover decision point corresponding to the current handover scenario is the source node in the source cell; Alternatively, based on the signal measurement report, determine that the source cell of the current terminal is a satellite cell and the current handover scenario is a handover from a satellite cell to a terrestrial cell; determine that the handover decision point corresponding to the current handover scenario is the core network of the source cell; Alternatively, based on the signal measurement report, determine that the source cell where the current terminal is located is a satellite cell and the current handover scenario is a handover from one satellite cell to another; determine that the handover decision point corresponding to the current handover scenario is the core network of the source cell or the source node in the source cell.

[0064] Specifically, different handover decision points are required for different handover scenarios. Especially for satellite-to-ground handover, the core network needs to make the handover decision, ultimately leading to the proposed handover process for satellite-to-ground integrated networking. In this application, when the core network needs to make the handover decision, it is specifically determined by the AMF service within the core network.

[0065] Figure 4 This is a flowchart of the decision-making process for switching points provided in this application, such as... Figure 4 As shown, embodiments of this application provide the determination of switching decision points and related judgment criteria, including: Regarding the judgment of 1 and 2: The source node may be a source ground base station, a source gateway station / base station in a satellite (transparent payload LEO), or a source satellite in a satellite (regenerative payload LEO), such as a distributed unit (DU) or a base station (gNodeB, gNB).

[0066] Judgment 1 is based on the different characteristics of Conditional Handover (CHO) and Handover (HO). CHO is suitable for scenarios with a large number of users, higher frequency bands, and low latency, reducing interruptions caused by handover. Furthermore, in areas with rapidly changing signal strength or at the edge, CHO avoids frequent HOs, triggering only when the signal quality falls below a certain threshold. HO, on the other hand, is suitable for lower frequency bands, regular scenarios with fewer users, or older network equipment or cross-network operator services. The simplified HO process helps ensure broad device compatibility and stability.

[0067] Regarding judgment 3: Building upon the previous steps, the measurement information of the ground base station cell is reported to the base station; therefore, the source node can only be the source base station. The source base station then determines which type of handover to perform based on information about neighboring cells in the measurement report. This involves a simple judgment by the source base station: In the case of ground-to-ground switching: neighboring cells are all ground cells, or those with strong Reference Signal Receiving Power (RSRP) are all ground cells. For applications with high real-time requirements, such as voice calls or certain real-time data services, ground base stations with lower latency may be preferred.

[0068] In the case of ground-to-satellite interaction: neighboring cells are all satellite cells, or cells with strong RSRP are all satellite cells, and there are relatively few ground cells.

[0069] Regarding the judgment of 4 and 5: The source node could be the source gateway station / base station in the transparent payload LEO, or it could be the source satellite (DU or gNB) in the regenerative payload.

[0070] For judgment 4, a simple judgment is made between the source base station / gateway station / satellite to determine which type of handover to perform: In the case of satellite-to-satellite communication: neighboring cells are all satellite cells, or cells with strong RSRP are all satellite cells, and there are relatively few terrestrial cells.

[0071] In a satellite-to-ground configuration: neighboring cells are all ground cells, or cells with high RSRP (Real-Time Retrieval Points). For applications with high real-time requirements, such as voice calls or certain real-time data services, ground base stations with lower latency may be preferred.

[0072] Regarding judgment 6: Once it is determined to be a ground-to-ground connection, the source node represents the source base station.

[0073] Regarding judgment 7: Once it is determined to be a star-to-star connection, the source node represents the source gateway station / base station in the transparent payload LEO, or it can be the source satellite (DU or gNB) in the regenerative payload LEO.

[0074] The cell handover method under the satellite-ground integrated network provided in this application determines the current handover scenario and the corresponding handover decision point of the current terminal based on the signal measurement report of the current terminal. This realizes the diversification of handover scenarios under the satellite-ground integrated network, enabling the base station, user terminal and AMF service in the core network to make handover decisions, improve handover efficiency, balance decision load, and improve cell handover efficiency in large-scale user and complex network environments.

[0075] In some embodiments, when the current handover scenario is a conditional handover, handing the current terminal from the source cell to the target cell includes: Determine that the current terminal meets the first execution condition; The switch trigger duration is determined to be greater than the preset trigger duration; Determine that the current terminal meets the second execution condition; Switch the current terminal from the source cell to the target cell; The first execution condition includes that the elevation angle between the current terminal and the satellite is less than a preset elevation angle threshold when the source cell is a satellite cell, or that the signal-to-noise ratio in the signal measurement report is less than a preset signal-to-noise ratio threshold when the source cell is a terrestrial cell. The second execution condition includes that the signal quality of the target cell is better than that of the source cell.

[0076] Specifically, Figure 5 This is a diagram illustrating the switching triggering process of the conditional switching provided in this application, as follows: Figure 5 As shown, it includes: Step 510: After receiving the switching command on the current terminal, it is necessary to determine whether the first execution condition is met.

[0077] The first execution condition is primarily used to determine the signal quality of the current terminal within the source cell. The source cell was monitored, and different evaluation criteria were set based on various conditions. Since the signal strength difference between the cell edge and center is relatively small for satellite cells, elevation angle was used as a better criterion than signal strength.

[0078] When determining the first execution condition, if the source cell is a satellite cell, the satellite's ephemeris position is used as a reference. The elevation angle is determined based on the satellite's position and the terminal's position information. The minimum elevation angle (which can be increased by an offset) is used as a preset elevation angle threshold. If the elevation angle is less than the preset threshold, it indicates poor signal quality, and the first execution condition is considered met. If the source cell is a terrestrial cell, the signal-to-noise ratio (SINR) in the signal measurement report is determined, and a preset SINR threshold is set. When the SINR is less than or equal to this preset threshold, the first execution condition is considered met.

[0079] Step 520: The optimal target cell will be selected based on the decision algorithm only when the first execution condition is met. The handover trigger duration is a period of time starting from when the first execution condition is met. Setting a handover trigger duration can avoid making handover decisions based on instantaneous signal quality. Therefore, a longer handover trigger duration is designed to avoid the ping-pong effect. Specifically, a preset trigger duration can be set, and execution will continue only when the handover trigger duration exceeds the preset trigger duration.

[0080] Step 530: Continue to determine whether the second execution condition is met. The second execution condition is mainly used to determine whether the signal quality of the target cell is better than that of the source cell.

[0081] Step 540: If all the above conditions are met, switch the current terminal from the source cell to the target cell.

[0082] The cell handover method under the satellite-ground integrated networking provided in this application embodiment can improve the success rate of cell handover in large-scale user and complex network environments by setting a first execution condition, a handover trigger duration, and a second execution condition.

[0083] In some embodiments, the second execution condition includes: When both the source cell and the target cell are satellite cells, the signal quality of the target cell is determined to be better than that of the source cell based on the elevation angle between the current terminal and the satellite corresponding to the source cell, and the elevation angle between the current terminal and the satellite corresponding to the target cell. When both the source cell and the target cell are terrestrial cells, based on the signal-to-noise ratio (SNR) in the current terminal's signal measurement report in the source cell and the SNR in the current terminal's signal measurement report in the target cell, it is determined that the signal quality of the target cell is better than that of the source cell. When the source cell is a terrestrial cell and the target cell is a satellite cell, based on the signal-to-noise ratio in the current terminal's signal measurement report in the source cell and the elevation angle between the current terminal and the satellite corresponding to the target cell, it is determined that the signal quality of the target cell is better than that of the source cell. When the source cell is a satellite cell and the target cell is a terrestrial cell, based on the elevation angle between the current terminal and the satellite corresponding to the source cell, and the signal-to-noise ratio in the signal measurement report of the current terminal in the target cell, it is determined that the signal quality of the target cell is better than that of the source cell.

[0084] Specifically, the second execution condition mainly involves reviewing cell quality over a period of time. This involves verifying the signal strength of the target cell and the source cell within the same cell range, comparing them to threshold values ​​(setting appropriate threshold values ​​can avoid the ping-pong effect). This can be further divided into the following cases: When both the source cell and the target cell are satellite cells, the elevation angle is used as the criterion. It is determined whether the elevation angle between the current terminal and the satellite corresponding to the target cell is greater than the first elevation angle threshold (threshold 1), and whether the elevation angle between the current terminal and the satellite corresponding to the source cell is less than the second elevation angle threshold (threshold 2). If so, it is determined that the signal quality of the target cell is better than that of the source cell, thus satisfying the second execution condition.

[0085] When both the source cell and the target cell are terrestrial cells, the signal-to-noise ratio (SNR) is used as the criterion. It is determined whether the SNR in the current terminal's signal measurement report in the target cell is greater than the first SNR threshold (threshold 3), and whether the SNR in the current terminal's signal measurement report in the source cell is less than the second SNR threshold (threshold 4). If so, it is determined that the signal quality of the target cell is better than that of the source cell, thus satisfying the second execution condition.

[0086] If the source cell is a terrestrial cell and the target cell is a satellite cell, determine whether the signal-to-noise ratio in the signal measurement report of the current terminal in the source cell is smaller than the second signal-to-noise ratio threshold (threshold 4), and determine whether the elevation angle between the current terminal and the satellite corresponding to the target cell is larger than the first elevation angle threshold (threshold 1). If so, determine that the signal quality of the target cell is better than the signal quality of the source cell, and satisfy the second execution condition.

[0087] If the source cell is a satellite cell and the target cell is a terrestrial cell, determine whether the elevation angle between the current terminal and the satellite corresponding to the source cell is smaller than the second elevation angle threshold (threshold 2), and determine whether the signal-to-noise ratio in the signal measurement report of the current terminal in the target cell is larger than the first signal-to-noise ratio threshold (threshold 3). If so, determine that the signal quality of the target cell is better than the signal quality of the source cell, and satisfy the second execution condition.

[0088] The cell handover method under the satellite-ground integrated networking provided in this application embodiment can improve the success rate of cell handover in large-scale user and complex network environments by setting a second execution condition.

[0089] In some embodiments, when the current handover scenario is a conditional handover, determining the target cell for the current terminal based on the current handover scenario and the handover decision point includes: Multiple terminals and multiple cells are identified; the multiple terminals include the current terminal, and the multiple cells include multiple satellite cells and multiple ground cells. Based on the location information, speed information and bandwidth requirements of each terminal, multiple terminals are clustered to determine multiple terminal groups. The optimization objective is determined based on at least one of the following factors for each cell: network throughput, network handover latency, load balancing, and terminal speed bonus. The constraints are determined based on at least one of the following factors: network coverage, network service capacity, network load capacity, and network handover latency of each cell. Based on the optimization objectives and constraints, a genetic algorithm is used to determine the target cell corresponding to each terminal group; The target cell corresponding to the terminal group to which the current terminal is located is determined as the target cell for the current terminal.

[0090] Specifically, under the satellite-ground integrated networking, the following problems still exist in conditional handover: a large number of users increase the burden of handover decision-making; the load on individual network nodes is too heavy; frequent changes in satellite-ground link connections lead to a large number of handovers; and a large number of handovers aggravate the ping-pong effect.

[0091] A handover decision algorithm can be designed to determine the target cell for the current terminal based on the current handover scenario and the handover decision point when the current handover scenario is a conditional handover.

[0092] Assume it exists Each terminal is represented as follows: , of which individual terminals , . Indicates the first Location information of each terminal; Indicates the first Speed ​​information of each terminal; Indicates the first The bandwidth requirements of each terminal. Multiple terminals include the current terminal.

[0093] exist Each community is represented as follows: Among them, satellite cells have There are [number] ground-level residential areas. One. Among them, the first 1 residential community , . Indicates the first Location information for each residential community; Indicates the first The height information of each cell, where the height of the base station is 0, i.e. ; Indicates the first The bandwidth that a satellite or base station in a given cell can provide.

[0094] Use binary Indicates time terminal With the community The correlation between them is defined as follows: a value of 1 indicates that the terminal has accessed a cell, and a value of 1 indicates that the terminal has not accessed a cell. It is important to note that a terminal at any given time... Although multiple available cells may exist, access can only be granted to one target cell. That is: To achieve group switching, the terminals must first be clustered and grouped. Figure 6 This is a flowchart illustrating the clustering algorithm provided in this application, as shown below. Figure 6 As shown, the fuzzy C-means FCM clustering method is used to group the terminals, taking into account their location, speed, and required bandwidth. Therefore, the dataset... The CCP There are several terminals to be clustered, and the dataset will be... Divided into kind, Any terminal in For the The membership degree of a class is . The classification result can be used with a matrix This matrix is ​​called a fuzzy clustering matrix and has the following properties: This indicates that the sum of the membership degrees from any terminal to all classes is 1.

[0095] The objective function of the FCM clustering algorithm is: Among them, membership degree Between 0 and 1, Indicates terminal With cluster center The Euclidean distance between them, i.e. Combining the membership constraint, a new objective function is constructed using the Lagrange multiplier: Therefore, a necessary condition for minimizing the objective function is to take the derivative with respect to all inputs, that is, to take the derivative with respect to the cluster centers. and membership degree Taking the derivative, we get: These two parameters are interrelated. The c-means clustering algorithm is a simple iterative process. Before the iteration begins, membership degrees can be randomly assigned. A value, then you can calculate a Then get a Based on this iteration, It continuously changes and iterates, gradually approaching the minimum value, when The algorithm stops when the changes cease or the specified number of iterations is reached. After iterations, the final result is obtained. For each terminal, it has a membership degree with each class. If in Find the largest one in the terminal If so, then the terminal is considered to belong to that category.

[0096] At any given time, the cell clusters the terminals based on the updated location information and performs group handover for the clustered terminals, while the unclustered terminals are directly handed over.

[0097] Next, we design the handover decision, using the network throughput, network handover latency, load balancing, and terminal speed reward value of each cell as optimization objectives, and considering the constraints such as network throughput, network handover latency, load balancing, and terminal speed reward value of each cell, to design an optimization problem.

[0098] Based on the optimization objectives and constraints, a genetic algorithm is used to determine the target cell corresponding to each terminal group.

[0099] The cell handover method under the space-ground integrated networking provided in this application embodiment considers multiple decision attributes in the space-ground integrated networking, including throughput, handover latency, load balancing, user speed impact, and multiple constraints such as network coverage, network service capacity, network load capacity, and handover latency threshold. It also calculates certain attributes by category, such as the link between the spaceborne base station and the user, and the link between the ground base station and the user. It uses group handover and conditional handover in the space-ground integrated networking to solve key problems such as large-scale user handover, excessive network handover burden, ping-pong effect, and low handover success rate.

[0100] In some embodiments, the optimization objective is determined based on at least one of the following: network throughput, network handover latency, load balancing, and terminal speed reward value for each cell: Based on the signal reception power and noise power of each cell, as well as the connection relationship between each cell and each terminal, the network throughput of each cell is determined. Based on the network handover latency between each terminal and each cell, and the connection relationship between each cell and each terminal, the network handover latency of each cell is determined. The load balance of each cell is determined based on the number of terminals currently connected to each cell and the maximum number of terminals allowed to connect to each cell. Based on the mobile speed of each terminal and the connection relationship between each cell and each terminal, the terminal speed reward value of each cell is determined. The optimization target is determined based on the network throughput, network handover latency, load balancing, and terminal speed reward value of each cell.

[0101] Specifically, for throughput calculation, the link between the satellite-based base station and the terminal is considered using a free-space loss model, while the link between the ground base station and the terminal is considered using a more complex channel model. At time... , residential area The transmission power is The transmit antenna gain is The receiving antenna gain is .

[0102] For satellite cells ( ) to terminal The received signal power is: Free space path loss The expression is: In the formula, Frequency, in MHz; The distance is expressed in km.

[0103] For ground base station cells ( ) to terminal The communication uses a TDL-D channel, which is LOS-dominant, therefore the received signal power is: in, For the multipath gain of the channel, For road damage, For shadow fading, all units are in dB.

[0104] For the path loss between the ground base station and the terminal, the LOS model for the Urban Microcell - Street Canyon (UMi) scenario in protocol 38.901 is used, and the expression is: In the formula, Frequency, in GHz; The distance is expressed in meters (m).

[0105] Meanwhile, the corresponding shadow decay is: It follows a normal distribution with a standard deviation of . The noise power is calculated as follows: in, Boltzmann's constant, Here, represents the receiver's equivalent noise temperature, and represents the satellite's... Assigned to the terminal The bandwidth of the satellite. To the terminal The wireless channel CNR is: For the terminal group of a cluster, the information-to-dryness ratio can be calculated using the value of the cluster center.

[0106] Based on the bandwidth required by the terminal, the bandwidth from the satellite can be obtained. To the terminal The achievable transmission rate is: For clustered terminal groups, the transmission rate can be calculated using the bandwidth information of the cluster center. The resulting transmission rate is the rate value for each terminal in this group, eliminating the need to calculate it individually for each terminal.

[0107] Based on the above analysis, the system throughput can be obtained as follows: Handover latency is modeled as the time consumed from the moment the connection with the source node is broken until the handover is completed. To ensure Quality of Service (QoS), handover latency needs to be considered as a constraint on candidate cells, and is divided into data transmission latency and propagation latency.

[0108] The terminal needs to receive signaling such as handover commands, and the size of the transmitted data is [missing information]. Therefore, the community To the terminal The data transmission latency is: terminal Arrive at the community The propagation delay is: in, This refers to the propagation delay from the target node to the terminal.

[0109] In addition, the waiting time from handover failure to restart and then to link reconstruction must also be considered when the handover fails. Therefore, considering the handover success rate The handover latency for each terminal can be obtained as follows: By considering handover success rate and latency, the handover latency metrics were evaluated as the number of terminals increased. For terminal groups, a handover success rate and latency representative of the group can be considered. Cluster centers are then used to calculate transmission latency and propagation latency.

[0110] The switching latency of the entire system, taking into account the average latency of all terminals, is expressed as: For load balancing, the load rate is defined first. For a given cell... In this context, the load factor is defined as the ratio of the number of currently connected terminals to the maximum allowed number of connected terminals in the cell. in Let m be the number of channels in cell m.

[0111] A comprehensive evaluation of all cells reveals that load balancing can be expressed as the variance of the load rate of each cell. A smaller variance indicates a more balanced load across the cells. Therefore, load balancing can be expressed as: The impact of terminal speed is analyzed first. Terminal speed has little impact on satellite access, but for terrestrial access, high-speed movement leads to more handover requirements, and insufficient handover time can even cause communication interruptions. Since the coverage area of ​​terrestrial base stations is much smaller than that of LEO (Light Array of Origin and Expansion), high-speed mobile UEs will frequently handover between base stations. Due to the high-speed movement of LEO around the Earth, even stationary UEs will face frequent handovers. Therefore, UEs with high speeds are more likely to choose satellite access, while low-speed terminals choose terrestrial base station access. Let the speed reward function for terminal n choosing cell m be: in It is a terminal speed, It is a step function. This is the speed threshold value (the speed threshold is the dividing line between the two choices). Therefore, in the above formula... This indicates that a satellite cell is selected. If the terminal speed is low and does not exceed a threshold, the function value is 0, which is less than the value when a ground base station is selected. If the terminal speed increases and exceeds the threshold, the function value also increases, and becomes greater than the value when a ground base station is selected. Similarly... This indicates that when choosing a terrestrial base station, the lower the terminal speed, the higher the reward function value obtained by choosing a terrestrial base station. If the terminal speed exceeds a threshold, the reward function value for choosing a terrestrial base station is lower than that for choosing a satellite. In summary, this speed function achieves biased selection for terminals with different speeds. For grouped terminals, the speed of the cluster center can be used.

[0112] By comprehensively evaluating the speed reward function values ​​of all terminals, the average value of the speed evaluation function can be obtained: Based on the above analysis, design optimization objectives. for: in These are the weight values ​​for throughput, handover latency, cell load balancing, and terminal speed reward, respectively. The weight values ​​can be set according to different business requirements. For example, if the business has high latency requirements, a larger weight value can be set. Clearly, for throughput and speed reward functions, larger values ​​are better, while for latency and load balancing, smaller values ​​are better.

[0113] In some embodiments, limiting conditions are determined based on at least one of the following: network coverage, network service capacity, network load capacity, and network handover latency of each cell: Based on the network coverage of each cell and the connection relationship between each cell and each terminal, the first constraint condition is determined. The second constraint is determined based on the terminal data transmission rate of each cell and the maximum service capacity of each cell. The third constraint is determined based on the maximum number of terminal connections in each cell and the connection relationship between each cell and each terminal. Based on the network handover latency of each cell and the preset network handover latency threshold, the fourth constraint condition is determined.

[0114] Specifically, regarding the cell coverage area in the constraints, satellite base station cells and terrestrial base station cells are considered separately. For satellite cells, the elevation angle is restricted. First, based on the positional relationship between the terminal and the satellite, the terminal's position can be determined. and community The angle of elevation between them is: in, ( This indicates the distance between the terminal and the satellite cell. and These represent the position information of satellite m and terminal n, respectively, and include the satellite's altitude. .

[0115] Therefore, the satellite's elevation angle needs to meet the constraint of the satellite's minimum elevation angle: For ground-based cells, the distance between the terminal and the base station is required. ( If the radius of the base station is less than the coverage radius of the base station, it is expressed as: For processing terminal groups, the location information of the cluster center can be used for calculation, and each terminal in a terminal group has the same coverage relationship.

[0116] Introducing binary Variables represent cells and terminal Coverage relationship between them: in, Indicates terminal Located in the community Within the coverage area, otherwise This indicates that the cell is not within the coverage area of ​​cell m.

[0117] Thus, the coverage relationship is obtained. and relationships Restrictions between: This constraint indicates that a connection between a cell and a terminal can only be evaluated if a coverage relationship exists. In practice, this constraint will be implemented earlier in the CHO execution phase design and considered separately from the specific optimization algorithm.

[0118] For cell service capacity, set a threshold for the maximum service capacity of the cell. This ensures that the sum of the rates of all terminals accessing cell m does not exceed this threshold, but the limit should also be determined based on the link connection situation. Therefore, the following constraint is obtained: To determine the cell's load capacity, set a threshold for the maximum number of terminals that can be connected via satellite. The following constraints are obtained: There is also a threshold value for handover latency. The constraints are expressed as follows: Based on the above embodiments, the optimization problem consisting of the above optimization objectives and constraints is solved by using a genetic algorithm. The genetic algorithm is a global optimization algorithm that can find the global optimal solution in a complex search space. It is suitable for finding the optimal handover point and handover strategy in large-scale terminal and complex cell environments. Figure 7 This is a flowchart illustrating the genetic algorithm provided in this application, as shown below. Figure 7 As shown, the method includes: Step 710, Initialization Population E contains E correlation matrices. It is n×m dimensional, representing individual terminals and The correlation relationships between base stations. Each element in the correlation matrix. The value can be: Step 720: Calculate fitness Calculate the fitness for each of the E association matrices in population E. The formula for fitness is as follows: The goal is to maximize the fitness function value. , and These are the penalty coefficients for the three constraints. If a constraint is satisfied, the value of the last three constraint terms is 0; if a constraint is not satisfied, a penalty term will be added.

[0119] Step 730, iterative calculation Crossover (reconstruction). Randomly select F instances from population E, each time selecting two incidence matrices. Swap the rows or columns of these two incidence matrices: The switching line is equivalent to switching the connection of each terminal to the base station; The switching column is equivalent to switching the terminals connected to each base station; Through exchange, we obtain A new correlation matrix.

[0120] Mutation. From the original population E, G correlation matrices are randomly selected and subjected to mutation operations, resulting in changes to rows or columns: The line changes, altering the base station the terminal connects to; The column changes, altering the terminals connected to the base station.

[0121] This will yield G new correlation matrices.

[0122] Population renewal (selection). From existing populations... Among the association matrices, the association matrix with the largest fitness value is selected for updating, resulting in the updated population E', which has the same size as E.

[0123] The loop ends here.

[0124] Step 740, Iteration and Selection In the first-stage genetic algorithm, the evolutionary steps of crossover, mutation, and population update are repeated for a predefined number of iterations, denoted by Imax. Finally, the association matrix with the highest fitness is selected as the target association matrix.

[0125] The cell handover method under a space-ground integrated network provided in this application adopts group handover, which groups a large number of users to effectively reduce the handover decision-making burden. Simultaneously, it uses CHO (Choice of Hits) to separate the handover preparation phase from the execution phase, achieving a higher handover success rate, and distributes the load of the handover decision-making node by adding UEs as handover decision points. Furthermore, by configuring different trigger times and handover trigger offsets in the handover preparation and execution phases, the ping-pong effect can be avoided while ensuring a high handover success rate. Finally, a genetic algorithm is used to process data in large-scale handover scenarios.

[0126] The apparatus provided in the embodiments of this application is described below. The apparatus described below can be referred to in correspondence with the method described above.

[0127] Figure 8 This is a structural schematic diagram of the cell handover device under the satellite-ground integrated network provided in this application, as shown below. Figure 8 As shown, the device includes: The handover decision module 810 is used to determine the current handover scenario and the corresponding handover decision point of the current handover scenario based on the signal measurement report of the current terminal. The cell determination module 820 is used to determine the target cell for the current terminal based on the current handover scenario and handover decision point; The cell handover module 830 is used to hand over the current terminal from the source cell to the target cell; The handover scenarios include handover from terrestrial cell to terrestrial cell, handover from terrestrial cell to satellite cell, handover from satellite cell to satellite cell, and handover from satellite cell to terrestrial cell.

[0128] The cell handover device under the satellite-ground integrated network provided in this application embodiment determines the current handover scenario and the corresponding handover decision point of the current terminal based on the signal measurement report of the current terminal; determines the target cell of the current terminal based on the current handover scenario and the handover decision point; and hands the current terminal from the source cell to the target cell. Since the handover scenarios include handover from terrestrial cell to terrestrial cell, handover from terrestrial cell to satellite cell, handover from satellite cell to satellite cell, and handover from satellite cell to terrestrial cell, it realizes the diversification of handover scenarios under the satellite-ground integrated network, can maximize the mobility in the communication scenario, can improve the efficiency of cell handover in large-scale user and complex network environments, and can cope with multiple handover scenarios, meeting the actual needs in mobile communication networks.

[0129] Figure 9 This is a schematic diagram of the structure of the electronic device provided in this application, such as... Figure 9 As shown, the electronic device may include: a processor 910, a communications interface 920, a memory 930, and a communications bus 940, wherein the processor 910, the communications interface 920, and the memory 930 communicate with each other via the communications bus 940. The processor 910 can call logical commands stored in the memory 930 to execute the methods described in the above embodiments, for example: Based on the signal measurement report of the current terminal, determine the current handover scenario and the corresponding handover decision point of the current handover scenario; based on the current handover scenario and the handover decision point, determine the target cell of the current terminal; hand over the current terminal from the source cell to the target cell; wherein, the handover scenario includes handover from terrestrial cell to terrestrial cell, handover from terrestrial cell to satellite cell, handover from satellite cell to satellite cell, and handover from satellite cell to terrestrial cell.

[0130] Furthermore, the logical commands in the aforementioned memory can be implemented as software functional units and sold or used as independent products, and can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several commands to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0131] The processor in the electronic device provided in this application embodiment can call logical instructions in the memory to implement the above method. Its specific implementation method is the same as the aforementioned method implementation method and can achieve the same beneficial effect, which will not be repeated here.

[0132] This application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to perform the methods provided in the above embodiments.

[0133] The specific implementation method is the same as the aforementioned method implementation method and can achieve the same beneficial effects, so it will not be repeated here.

[0134] This application provides a computer program product, including a computer program that, when executed by a processor, implements the method described above.

[0135] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0136] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A cell handover method under satellite-ground integration networking, characterized in that, The method comprises: determining a current handover scenario of the current terminal and a handover decision point corresponding to the current handover scenario based on a signal measurement report of the current terminal; determining a target cell of the current terminal based on the current handover scenario and the handover decision point; handing over the current terminal from a source cell to the target cell; wherein the handover scenario comprises handover from a terrestrial cell to a terrestrial cell, handover from a terrestrial cell to a satellite cell, handover from a satellite cell to a satellite cell, and handover from a satellite cell to a terrestrial cell.

2. The cell handover method in the star-satellite converged networking according to claim 1, characterized in that, The method comprises: determining a current handover scenario of the current terminal and a handover decision point corresponding to the current handover scenario based on a signal measurement report of the current terminal; determining that the current handover scenario is conditional handover and determining that the handover decision point corresponding to the current handover scenario is the current terminal based on the signal measurement report; or, determining that the source cell where the current terminal is located is a terrestrial cell and the current handover scenario is handover from a terrestrial cell to a satellite cell based on the signal measurement report; determining that the handover decision point corresponding to the current handover scenario is a core network of the source cell; or, determining that the source cell where the current terminal is located is a terrestrial cell and the current handover scenario is handover from a terrestrial cell to a terrestrial cell based on the signal measurement report; determining that the handover decision point corresponding to the current handover scenario is a source node in the source cell; or, determining that the source cell where the current terminal is located is a satellite cell and the current handover scenario is handover from a satellite cell to a terrestrial cell based on the signal measurement report; determining that the handover decision point corresponding to the current handover scenario is a core network of the source cell; 3.The cell handover method under the star-ground fusion networking according to claim 2, characterized in that, or, determining that the source cell where the current terminal is located is a satellite cell and the current handover scenario is handover from a satellite cell to a satellite cell based on the signal measurement report; determining that the handover decision point corresponding to the current handover scenario is a core network of the source cell or a source node in the source cell. In the case that the current handover scenario is conditional handover, the method comprises: determining that the current terminal satisfies a first execution condition; determining that a handover trigger duration is greater than a preset trigger duration; determining that the current terminal satisfies a second execution condition; handing over the current terminal from the source cell to the target cell; the first execution condition comprises that, in the case that the source cell is a satellite cell, an elevation angle between the current terminal and a satellite is less than a preset elevation angle threshold, or in the case that the source cell is a terrestrial cell, a signal-to-noise ratio in the signal measurement report is less than a preset signal-to-noise ratio threshold; 4. The cell handover method in the star-satellite converged networking according to claim 3, characterized in that, the second execution condition comprises that a signal quality of the target cell is better than a signal quality of the source cell. The second execution condition comprises: in the case that the source cell and the target cell are both satellite cells, determining that the signal quality of the target cell is better than the signal quality of the source cell based on an elevation angle between the current terminal and a satellite corresponding to the source cell and an elevation angle between the current terminal and a satellite corresponding to the target cell. In a case where the source cell and the target cell are both ground cells, determining that the signal quality of the target cell is better than the signal quality of the source cell based on a signal-to-noise ratio in a signal measurement report of the current terminal in the source cell and a signal-to-noise ratio in a signal measurement report of the current terminal in the target cell; In a case where the source cell is a ground cell and the target cell is a satellite cell, determining that the signal quality of the target cell is better than the signal quality of the source cell based on a signal-to-noise ratio in a signal measurement report of the current terminal in the source cell and an elevation angle between the current terminal and a satellite corresponding to the target cell; In a case where the source cell is a satellite cell and the target cell is a ground cell, determining that the signal quality of the target cell is better than the signal quality of the source cell based on an elevation angle between the current terminal and a satellite corresponding to the source cell and a signal-to-noise ratio in a signal measurement report of the current terminal in the target cell.

5. The cell handover method in the star-satellite converged networking according to claim 2, characterized in that, In a case where the current handover scenario is conditional handover, the determining of the target cell of the current terminal based on the current handover scenario and the handover decision point comprises: determining a plurality of terminals and a plurality of cells; the plurality of terminals comprises the current terminal, and the plurality of cells comprises a plurality of satellite cells and a plurality of ground cells; clustering the plurality of terminals based on position information, speed information and bandwidth demand of each terminal to determine a plurality of terminal groups; determining an optimization target based on at least one of network throughput, network handover delay, load balancing degree and terminal speed reward value of each cell; determining a restriction condition based on at least one of network coverage, network service capacity, network load capacity and network handover delay of each cell; determining the target cell corresponding to each terminal group by using a genetic algorithm based on the optimization target and the restriction condition; determining the target cell corresponding to the terminal group in which the current terminal is located as the target cell of the current terminal.

6. The cell handover method in the star-satellite converged networking according to claim 5, characterized in that, The determining of the optimization target based on at least one of network throughput, network handover delay, load balancing degree and terminal speed reward value of each cell comprises: determining the network throughput of each cell based on signal receiving power, noise power of each cell and a connection relationship between each cell and each terminal; determining the network handover delay of each cell based on a network handover delay between each terminal and each cell and the connection relationship between each cell and each terminal; determining the load balancing degree of each cell based on a number of terminals currently accessed by each cell and a maximum number of terminals allowed to access each cell; determining the terminal speed reward value of each cell based on a moving speed of each terminal and the connection relationship between each cell and each terminal; determining the optimization target based on the network throughput, the network handover delay, the load balancing degree and the terminal speed reward value of each cell.

7. The cell handover method in the star-satellite converged networking according to claim 5, characterized in that, The determining of the restriction condition based on at least one of network coverage, network service capacity, network load capacity and network handover delay of each cell comprises: determine a first restriction condition based on network coverage of each cell and connection relationship between each cell and each terminal; determine a second restriction condition based on terminal data transmission rate of each cell and maximum service capacity of each cell; determine a third restriction condition based on maximum terminal connection number of each cell and connection relationship between each cell and each terminal; determine a fourth restriction condition based on network switching delay of each cell and preset network switching delay threshold.

8. A cell handover device under satellite-ground integration networking, characterized in that, Comprise: a handover decision module, configured to determine a current handover scenario of a current terminal and a handover decision point corresponding to the current handover scenario based on a signal measurement report of the current terminal; a cell determination module, configured to determine a target cell of the current terminal based on the current handover scenario and the handover decision point; a cell handover module, configured to hand over the current terminal from a source cell to the target cell; wherein the handover scenario comprises handover from a ground cell to a ground cell, handover from a ground cell to a satellite cell, handover from a satellite cell to a satellite cell, and handover from a satellite cell to a ground cell.

9. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the computer program to realize the cell handover method in the integrated satellite-ground networking as claimed in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to realize the cell handover method in the integrated satellite-ground networking as claimed in any one of claims 1 to 7.

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