Satellite communication command terminal intelligent switching method and system

Abstract

The present application relates to the technical field of satellite communication, and particularly relates to a satellite communication command and control terminal intelligent switching method and system, the method comprising: acquiring situation information of a command and control terminal and task parameters of a current command and control task; determining at least one candidate satellite and a corresponding availability prediction result based on the situation information and the task parameters; determining comprehensive scores of communication links corresponding to each candidate satellite based on the situation information and the availability prediction result; generating a link switching decision based on the comprehensive score results, with the goal of optimal service continuity and communication quality; and executing link switching under the condition that the command and control terminal maintains current service without interruption according to the link switching decision. By predicting the visibility of each candidate satellite within a future preset time window and combining the predicted motion trajectory of the command and control terminal to make a forward-looking switching decision, the quality decline risk of a main link can be identified in advance in a dynamically changing environment, and service interruption caused by switching time lag can be effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of satellite communication technology, and in particular to a method and system for intelligent switching of satellite communication command and control terminals. Background Technology

[0002] During the execution of command and control tasks, satellite communication command and control terminals may experience a decline in the quality of the primary satellite link or even become unusable due to dynamic factors such as terminal location movement, target satellite transit, terrain obstruction, and electromagnetic interference. Therefore, it is necessary to switch between communication links corresponding to multiple candidate satellites to ensure the continuity of command and control services.

[0003] In existing technologies, link switching of satellite communication command and control terminals is mostly triggered by fixed signal strength thresholds. This can easily lead to problems such as delayed switching timing causing service interruptions, or frequent switching due to short-term signal fluctuations increasing signaling overhead. Therefore, there is an urgent need for an intelligent switching method for satellite communication command and control terminals that can integrate situational prediction, satellite availability prediction, and multi-objective optimization decision-making. Summary of the Invention

[0004] This application provides a method and system for intelligent switching of satellite communication command and control terminals. Under dynamically changing environments and service requirements, it can proactively make link switching decisions based on the predicted motion trajectory of the command and control terminal and the availability prediction results of each candidate satellite, thereby ensuring the continuity of high-priority services and communication quality.

[0005] To address the above problems, the embodiments of this application provide the following technical solutions: In a first aspect, this application provides a method for intelligent handover of a satellite communication command and control terminal. The method includes: acquiring situational information of the command and control terminal and task parameters of the current command and control mission; the situational information is used to indicate link quality, terminal pose and motion trends, environmental conditions, and service requirements; it indicates the priority level, communication bandwidth requirements, and communication duration requirements of the current command and control mission; based on the situational information and task parameters, determining at least one candidate satellite and its corresponding availability prediction result; the availability prediction result is used to indicate the visible time window, continuous coverage duration, and expected signal attenuation degree of each candidate satellite within a future preset time window; based on the situational information and satellite availability prediction result, determining a comprehensive score for the communication link corresponding to at least one candidate satellite; based on the comprehensive score result, generating a link handover decision with the goal of optimizing service continuity and communication quality; and executing a link handover according to the link handover decision, while ensuring the command and control terminal maintains its current service without interruption.

[0006] Based on the aforementioned technical means, this application obtains the situational information and mission parameters of the command and control terminal, and predicts the visible time window, continuous coverage duration, and expected signal attenuation of each candidate satellite within a preset future time window. Then, it combines the situational information to comprehensively score the communication links corresponding to each candidate satellite, and proactively generates link switching decisions. This can identify the risk of primary link quality degradation in advance in a dynamically changing environment, effectively avoid service interruption caused by delayed switching timing, and maintain uninterrupted current services during the switching process, thereby improving the communication guarantee capability of high-priority command and control services.

[0007] In one possible implementation, the terminal pose and motion trend include: the location information, speed, and direction of motion of the command and control terminal; environmental conditions include: terrain occlusion characteristics; based on situational information and mission parameters, at least one candidate satellite and its corresponding availability prediction result are determined, including: based on the location information, speed, direction of motion, and communication duration requirements of the command and control terminal, determining the predicted motion trajectory of the command and control terminal within a future preset time window; based on the predicted motion trajectory and the ephemeris information of the initial satellites, determining the elevation and azimuth sequences of at least one candidate satellite relative to the command and control terminal; based on terrain occlusion characteristics, determining at least one candidate satellite from the initial satellites; based on the ephemeris information and predicted motion trajectory of at least one candidate satellite, determining the start and end times, duration of continuous coverage, and path loss of the visible time window of at least one candidate satellite relative to the command and control terminal within a future preset time window; and based on the start and end times, duration of continuous coverage, and path loss of the visible time window of at least one candidate satellite relative to the command and control terminal within a future preset time window, determining the availability prediction result.

[0008] Based on the above technical means, this application aligns the predicted motion trajectory of the command and control terminal with the ephemeris information of the candidate satellites in a time sequence, and simulates the visible time window, continuous coverage duration and path loss of each candidate satellite relative to the command and control terminal in the future time window. This enables the availability prediction results to reflect the dynamic changes in satellite visibility during the terminal's movement, avoids visibility deviation caused by prediction based on a fixed position, and effectively improves the accuracy of link switching timing judgment.

[0009] In one possible implementation, link quality includes: signal strength, signal-to-noise ratio, bit error rate, and link delay of the communication link corresponding to at least one candidate satellite; environmental conditions also include: electromagnetic interference intensity; service requirements include: service type and quality of service requirement level; based on situational information and satellite availability prediction results, a comprehensive score for the communication link corresponding to at least one candidate satellite is determined, including: determining the link quality score of at least one candidate satellite based on the signal strength, signal-to-noise ratio, bit error rate, and link delay of the communication link corresponding to at least one candidate satellite; determining the link availability duration score of at least one candidate satellite based on the satellite availability prediction results; determining the anti-interference capability score of at least one candidate satellite based on the electromagnetic interference intensity; determining the service adaptability score of at least one candidate satellite based on the service type and quality of service requirement level; and determining the comprehensive score of the communication link corresponding to at least one candidate satellite based on the link quality score, link availability duration score, anti-interference capability score, and service adaptability score of at least one candidate satellite.

[0010] Based on the aforementioned technical means, this application decomposes the link score into four dimensions: link quality, link availability duration, anti-interference capability, and service adaptability. This allows the score results to simultaneously reflect the current quality, future availability, robustness to the current electromagnetic environment, and degree of matching with service requirements of candidate satellite links. This avoids the one-sided reflection of the overall link guarantee capability by a single-dimensional score and effectively improves the comprehensiveness of link selection and the degree of service matching.

[0011] In one possible implementation, a comprehensive score for the communication link corresponding to at least one candidate satellite is determined based on the link quality score, link availability score, anti-interference capability score, and service adaptability score of at least one candidate satellite. This includes: constructing a multi-objective optimization function, using the link quality score, link availability score, anti-interference capability score, and service adaptability score as input variables, with the optimization objectives being minimizing link switching frequency and minimizing service interruption probability; calculating the comprehensive score value of each candidate satellite based on the multi-objective optimization function and dynamic weight coefficients; the dynamic weight coefficients are determined according to the current parameters indicated by the mission parameters. The priority level of the control task and the service type indicated by the service requirements are dynamically determined. The dynamic weight coefficients correspond to the task parameters and service requirements as follows: when the service type is a command and control instruction service, the weight coefficient corresponding to the service adaptability score is the largest; when the priority level indicated by the task parameters is higher than the preset level threshold, the weight coefficients corresponding to the link quality score and the link availability time score increase dynamically over time, and the increase is positively correlated with the cumulative movement distance in the predicted movement trajectory of the command and control terminal; when the electromagnetic interference intensity indicated by the environmental conditions is higher than the preset intensity threshold, the weight coefficient corresponding to the anti-interference capability score increases.

[0012] Based on the aforementioned technical means, this application uses a multi-objective optimization function to jointly optimize the link switching frequency and service interruption probability. It dynamically adjusts the weight coefficients of each dimension score according to the service type, task priority, terminal motion state, and electromagnetic environment. This ensures that the comprehensive score prioritizes service adaptability in command and control scenarios, strengthens the constraint weights of link quality and availability in high-priority and high-dynamic scenarios, and strengthens the constraint weights of anti-interference in strong electromagnetic interference scenarios. In this way, it dynamically adapts the optimal link selection strategy in a changing battlefield environment and improves the adaptability of link switching decisions to complex environments.

[0013] In one possible implementation, based on the comprehensive scoring results, and with the goal of optimizing service continuity and communication quality, a link switching decision is generated. This includes: obtaining the comprehensive scores of the communication links corresponding to each candidate satellite and sorting them from high to low; determining the comprehensive score ranking of the current primary link and determining the target link based on the comprehensive score ranking; wherein, when the communication link corresponding to the top-ranked candidate satellite is different from the current primary link, the switching cost of switching from the current primary link to the communication link corresponding to the top-ranked candidate satellite is calculated; the switching cost includes at least switching delay, signaling overhead, and frequency resource occupation; based on the comprehensive score difference between the comprehensive score of the communication link corresponding to the top-ranked candidate satellite and the comprehensive score of the current primary link, combined with the switching cost, the switching benefit is determined; when the switching benefit is greater than a preset switching threshold, the communication link corresponding to the top-ranked candidate satellite is determined as the target link, and a switching decision to switch to the target link is generated.

[0014] Based on the aforementioned technical means, this application introduces a comparison mechanism between switching costs and switching benefits in the switching decision-making process. By incorporating the comprehensive score difference and switching costs into the decision-making basis, it can avoid frequent switching due to short-term fluctuations in link scores and can also trigger switching in a timely manner when the primary link score drops significantly. This ensures business continuity while reducing unnecessary switching overhead and improving the stability and economy of link switching decisions.

[0015] In one possible implementation, the handover cost also includes: indication information on whether the satellite orbit types before and after the handover are the same; when the satellite orbit types before and after the handover are different, the handover cost is higher than the handover cost of the same orbit type handover; the handover benefit is the normalized value of the comprehensive score difference minus the handover cost; and the preset handover threshold is higher than the threshold value of non-command and control command services when the service type is command and control command service.

[0016] Based on the aforementioned technical means, this application incorporates satellite orbit type differences into the switching cost, making the cost of switching across orbit types higher than that of switching within the same orbit type, thereby avoiding frequent triggering of cross-orbit switching when link scores are close; by normalizing the switching benefits to make the score difference comparable to the switching cost, and by setting a higher switching threshold for command and control services, the switching decisions in command and control service scenarios become more cautious, avoiding frequent switching of high-priority task links due to short-term score fluctuations.

[0017] In one possible implementation, the method further includes: when the communication bandwidth requirement indicated by the service demand exceeds the bandwidth that the communication link corresponding to the candidate satellite with the highest comprehensive score can provide, selecting at least two communication links from at least one candidate satellite as an aggregated link set based on the continuous coverage duration and expected signal attenuation degree of each candidate satellite indicated by the availability prediction results; wherein the overlapping time period of the continuous coverage duration of each link in the aggregated link set within a future preset time window is not less than a preset duration threshold, and the total available bandwidth of each link is not less than the communication bandwidth requirement; obtaining the real-time bandwidth, latency, packet loss rate, and expected signal attenuation trend of each link in the aggregated link set within the overlapping time period; and based on the real-time bandwidth, latency, packet loss rate, and expected signal attenuation trend... The expected signal attenuation trend is used to determine the dynamic traffic splitting weight of each link at each time point within the overlapping time period. The expected signal attenuation trend indicates that when the expected signal attenuation of a link at a future time point exceeds a preset attenuation threshold, the dynamic traffic splitting weight of that link at the corresponding future time point is reduced. Based on the dynamic traffic splitting weight corresponding to each time point, service data is allocated to each link in the aggregated link set for parallel transmission. When any link in the aggregated link set experiences link quality deterioration or is about to exceed its continuous coverage duration within the overlapping time period, the aggregated link set is updated based on the remaining candidate satellites in the availability prediction results. The dynamic traffic splitting weight is re-determined in the updated aggregated link set, and the dynamic addition or removal of links is completed without interrupting service transmission.

[0018] Based on the aforementioned technical means, this application dynamically constructs an aggregated link set based on availability prediction results when single-link bandwidth is insufficient, and dynamically adjusts the traffic distribution weight at each moment according to the real-time quality and expected attenuation trend of each link, so that aggregated transmission can stably provide the required total bandwidth during the coverage overlap period; when the quality of any link deteriorates or is about to exceed the coverage duration, the aggregated set is dynamically updated and the weights are reallocated based on the remaining candidate satellites, so that the aggregated links can be dynamically added or removed without interrupting the service, thereby effectively ensuring the continuity and transmission quality of high bandwidth demand services.

[0019] In one possible implementation, link switching is performed based on a link switching decision, provided that the current service is not interrupted at the command and control terminal. This includes: obtaining the target link identifier indicated in the link switching decision; initiating a link establishment request to the target satellite corresponding to the target link based on the target link identifier; synchronizing the context information of the current service between the target link and the current primary link, wherein the context information includes at least the IP address mapping relationship of the current session, the transport layer connection status, the data packet sequence number, and the application layer session status; after the target link is established and the context information is synchronized, switching the service traffic from the current primary link to the target link; and releasing the communication resources occupied by the current primary link after the switch is completed.

[0020] Based on the above technical means, this application establishes a target link in advance and synchronizes multiple layers of context information such as the IP address mapping relationship of the service, the transport layer connection status, the data packet sequence number and the application layer session status before the switch. This ensures that when the service traffic is switched after the target link is established and the context is synchronized, the application layer session remains continuous, the transport layer connection is uninterrupted and the data packets are not lost, thereby achieving a smooth transition without service interruption during the link switch.

[0021] Secondly, this application provides an intelligent handover system for satellite communication command and control terminals. The system includes: a situational awareness module configured to acquire situational information of the command and control terminal and task parameters of the current command and control task; the situational information is used to indicate link quality, terminal pose and motion trend, environmental conditions and service requirements; and to indicate the priority level, communication bandwidth requirements and communication duration requirements of the current command and control task; a satellite availability prediction module configured to determine at least one candidate satellite and its corresponding availability prediction result based on the situational information and task parameters; the availability prediction result is used to indicate the visible time window, continuous coverage duration and expected signal attenuation degree of each candidate satellite within a future preset time window; a link comprehensive evaluation module configured to determine a comprehensive score of the communication link corresponding to at least one candidate satellite based on the situational information and satellite availability prediction result; a handover decision module configured to generate a link handover decision based on the comprehensive score result, with the goal of optimizing service continuity and communication quality; and a handover execution module configured to execute a link handover according to the link handover decision, while ensuring that the current service of the command and control terminal is not interrupted.

[0022] The intelligent switching system for satellite communication command and control terminals provided in this application embodiment is used to execute the intelligent switching method for satellite communication command and control terminals provided in the first aspect above. Its implementation principle and technical effect are similar, and will not be repeated here.

[0023] Thirdly, this application provides an electronic device, including: a processor and a memory; the memory stores processor-executable instructions, and when the processor is configured to execute the instructions, the electronic device implements the method provided in the first aspect above.

[0024] Fourthly, this application provides a computer-readable storage medium that, when computer-executable instructions stored in the computer-readable storage medium are executed by a processor of an electronic device, causes the electronic device to perform the method provided in the first aspect above.

[0025] The electronic device and computer-readable storage medium provided in the embodiments of this application are used to execute the intelligent switching method for satellite communication command and control terminals provided in the first aspect above. Their implementation principle and technical effects are similar, and will not be repeated here.

[0026] Therefore, the above-mentioned technical features of this application have the following beneficial effects: (1) This application obtains the situation information and mission parameters of the command and control terminal, and predicts the visibility of each candidate satellite within a future preset time window, and makes a forward-looking link switching decision. It can identify the risk of degradation of the primary link quality in advance in a dynamically changing environment, effectively avoid service interruption caused by delayed switching, and improve the communication guarantee capability of high-priority command and control services.

[0027] (2) This application decomposes the link score into four dimensions: link quality, link availability, anti-interference capability, and service adaptability. Through a multi-objective optimization function and dynamic weighting mechanism, the comprehensive score can be dynamically adapted according to the service type, task priority, terminal motion state and electromagnetic environment, so as to select the link that best suits the current situation in the ever-changing battlefield environment.

[0028] (3) This application introduces a comparison mechanism between switching costs and switching benefits in the switching decision-making process, and sets a higher switching threshold for the command and control instruction business to avoid frequent switching of high-priority task links caused by short-term score fluctuations, thereby reducing unnecessary switching overhead while ensuring business continuity.

[0029] (4) When the bandwidth of a single link is insufficient, this application dynamically constructs an aggregated link set based on the availability prediction results, and dynamically adjusts the diversion weight according to the real-time quality and expected attenuation trend of each link, so that the aggregated transmission can stably provide the required total bandwidth during the overlapping coverage period, and dynamically updates the aggregated set based on the remaining candidate satellites when the link deteriorates, so as to realize the dynamic addition or removal of links without interrupting the service.

[0030] (5) This application establishes the target link in advance and synchronizes multi-layer context information before switching, so that the application layer session remains continuous, the transport layer connection is uninterrupted, and the data packets are not lost when the service traffic is switched.

[0031] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written documents of this application.

[0032] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0033] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of a satellite communication command and control terminal intelligent switching system provided in an embodiment of this application; Figure 2 This is a flowchart illustrating a satellite communication command and control terminal intelligent handover method provided in an embodiment of this application; Figure 3 This is a flowchart illustrating the candidate satellite availability prediction process in a satellite communication command and control terminal intelligent handover method provided in an embodiment of this application. Figure 4 This is a flowchart illustrating the comprehensive scoring of communication links in a satellite communication command and control terminal intelligent handover method provided in an embodiment of this application; Figure 5 This is a flowchart illustrating the link switching decision process in a satellite communication command and control terminal intelligent switching method provided in this application embodiment. Detailed Implementation

[0034] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0035] To enable those skilled in the art to better understand the technical solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0036] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of 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. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0037] In the description of the embodiments of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0038] This application provides a method for intelligent switching of a satellite communication command and control terminal, which can be applied to satellite communication command and control terminals.

[0039] In some embodiments, the satellite communication command and control terminal can be mounted on a mobile vehicle, such as a vehicle, ship, aircraft, robot, or soldier's backpack station. During the execution of command and control tasks, the satellite communication command and control terminal may experience a decline in the quality of the primary satellite link or even become unusable due to dynamic factors such as terminal location movement, target satellite transit, terrain obstruction, and electromagnetic interference, requiring switching between communication links corresponding to multiple candidate satellites.

[0040] Figure 1 This is a schematic diagram of the structure of a satellite communication command and control terminal intelligent handover system provided in an embodiment of this application. Figure 1 As shown, the system includes: a situational awareness module 101, a satellite availability prediction module 102, a link comprehensive evaluation module 103, a handover decision module 104, and a handover execution module 105.

[0041] The situation awareness module 101 is configured to acquire situation information of the command and control terminal and task parameters of the current command and control task; the situation information is used to indicate link quality, terminal pose and motion trend, environmental conditions and service requirements; and to indicate the priority level, communication bandwidth requirements and communication duration requirements of the current command and control task.

[0042] The satellite availability prediction module 102 is configured to determine at least one candidate satellite and the availability prediction result corresponding to at least one candidate satellite based on situational information and mission parameters. The availability prediction result is used to indicate the visible time window, continuous coverage duration and expected signal attenuation degree of each candidate satellite in the future preset time window.

[0043] The link comprehensive evaluation module 103 is configured to determine the comprehensive score of the communication link corresponding to at least one candidate satellite based on situational information and satellite availability prediction results.

[0044] The switching decision module 104 is configured to generate link switching decisions based on the comprehensive scoring results, with the goal of optimizing service continuity and communication quality.

[0045] The switching execution module 105 is configured to perform link switching based on the link switching decision, provided that the current service of the command and control terminal is not interrupted.

[0046] It should be noted that, Figure 1 The structure shown does not constitute a limitation on the intelligent handover system for satellite communication command and control terminals. The system may include more or fewer modules than shown, or combine some modules, or split some modules, or have different module arrangements. The modules shown can be implemented in hardware, software, or a combination of software and hardware.

[0047] based on Figure 1 The system shown, Figure 2 This is a flowchart illustrating a satellite communication command and control terminal intelligent handover method provided in an embodiment of this application. Figure 2 As shown, the method includes the following steps: S101. Obtain the situation information of the command and control terminal and the task parameters of the current command and control task.

[0048] Among them, situational information is used to indicate link quality, terminal pose and motion trend, environmental conditions and service requirements; and to indicate the priority level, communication bandwidth requirements and communication duration requirements of the current command and control task.

[0049] Specifically, the situational awareness module 101 acquires information about the status of the command and control terminal and the external environment in real time through the sensor group, communication interface and external data source of the command and control terminal.

[0050] Specifically, situational information is a multi-dimensional comprehensive set of information that characterizes the command and control terminal's own motion state, communication environment, service carrying requirements, and current task attributes.

[0051] The situation information includes: link quality, terminal pose and motion trend, environmental conditions and service requirements. These elements are collected and encapsulated synchronously within the command and control terminal according to a unified time base, so that each stage of subsequent availability prediction, link comprehensive scoring and handover decision can extract the corresponding fields from the situation information, thereby avoiding the repeated collection of raw data in each stage and ensuring the temporal consistency of data.

[0052] Link quality is used to indicate the overall performance of the communication link between the command and control terminal and each candidate satellite at the physical layer and the link layer. Link quality includes four dimensions of indicators: signal strength, signal-to-noise ratio, bit error rate, and link delay. Signal strength represents the power level of the signal received by the receiver's radio frequency front end. Signal-to-noise ratio represents the ratio of useful signal power to noise and interference power. Bit error rate represents the ratio of errors in the transmitted bits per unit time. Link delay represents the time required for a data packet to travel from the command and control terminal to the target node via satellite relay.

[0053] Terminal pose and motion trend are used to characterize the spatial position, speed and orientation of the command and control terminal at the current moment. The terminal pose and motion trend include position information, speed and direction of motion. The position information is obtained by the Global Navigation Satellite System (GNSS) module, and the speed and direction of motion are calculated jointly by the GNSS module and the Inertial Measurement Unit (IMU).

[0054] Environmental conditions are used to characterize the impact of the geographical and electromagnetic environment of the command and control terminal on satellite signal propagation.

[0055] The aforementioned environmental conditions include terrain shielding features and electromagnetic interference intensity.

[0056] The aforementioned terrain obstruction features are determined based on elevation databases or prior terrain data and are used to indicate the obstruction of satellite signals below a specific elevation angle by the terrain surrounding the command and control terminal.

[0057] The electromagnetic interference intensity mentioned above is collected in real time by the electromagnetic spectrum sensing module and is used to indicate the level of interference of non-cooperative signals to the communication link in the current frequency band.

[0058] The above business requirements are used to characterize the current command and control mission's requirements for the communication link's carrying capacity.

[0059] The above business requirements include business type and service quality requirement level.

[0060] The aforementioned service types include at least one of the following: command and control instruction service, situation reporting service, audio and video service, and file transfer service.

[0061] The above service quality requirement levels are used to indicate the minimum acceptable levels of bandwidth, latency, packet loss rate, and reliability for this service.

[0062] The above task parameters are used to characterize the attributes of the current command and control task in three dimensions: priority, resource requirements, and duration.

[0063] The task parameters include priority level, communication bandwidth requirements, and communication duration requirements.

[0064] Priority levels are used to distinguish the scheduling priority of different tasks in subsequent dynamic weight allocation.

[0065] The aforementioned communication bandwidth requirements are used to trigger the aggregation link determination, and the communication duration requirements are used to determine the time window length for availability prediction.

[0066] For example, the command and control terminal may include a GNSS module, an IMU, a radio frequency signal monitoring module, a channel quality monitoring module, and an electromagnetic spectrum sensing module.

[0067] The GNSS module is used to receive multi-constellation satellite navigation signals to determine the three-dimensional position coordinates and three-dimensional velocity vector of the command and control terminal; the IMU is used to measure the three-axis acceleration and three-axis angular velocity of the command and control terminal, and to fuse and filter the position information and motion velocity output by the GNSS module to obtain the motion direction and motion velocity under anti-interference conditions.

[0068] The radio frequency signal monitoring module is used to sample the downlink signals of the communication links corresponding to each candidate satellite in real time and extract the signal strength, signal-to-noise ratio and bit error rate.

[0069] The channel quality monitoring module is used to measure the link delay of the communication link corresponding to each candidate satellite through link layer probe messages or heartbeat messages.

[0070] The electromagnetic spectrum sensing module is used to perform broadband spectrum scanning within the radio frequency band supported by the command and control terminal, detect the power spectral density of non-cooperative signals, and output the detected power spectral density as the electromagnetic interference intensity. Terrain occlusion characteristics are determined by the command and control terminal based on a pre-loaded elevation database or prior terrain data, combined with the current location information of the command and control terminal and the azimuth and elevation angles of each candidate satellite, using line-of-sight propagation to determine whether each candidate satellite is obstructed by terrain.

[0071] In one possible implementation, after acquiring situational information, the situational awareness module 101 splits four elements—link quality, terminal pose and motion trend, environmental conditions, and service requirements—into fields based on the input requirements of downstream modules: The terminal pose and motion trend, as well as terrain occlusion features in the environmental conditions, are sent to the satellite availability prediction module 102 to support predicted trajectory extrapolation and visible satellite selection; the link quality and electromagnetic interference intensity in the environmental conditions are sent to the link comprehensive evaluation module 103 to support link quality scoring and anti-interference capability scoring; and the communication bandwidth requirements and service types in the service requirements are sent to the aggregated link scheduling stage to support aggregated link determination and switching threshold configuration. Thus, a single set of situational information simultaneously drives three downstream stages: availability prediction, link comprehensive evaluation, and aggregated scheduling. Each stage extracts the corresponding fields from the situational information as needed, eliminating the need for independent collection of raw data.

[0072] S102. Based on situational information and mission parameters, determine at least one candidate satellite and the availability prediction result corresponding to at least one candidate satellite.

[0073] Among them, the availability prediction results are used to indicate the visible time window, continuous coverage duration and expected signal attenuation of each candidate satellite within a future preset time window.

[0074] The aforementioned preset time window refers to a future time interval determined with the current moment as the starting point and the communication duration requirement as the length. The length of the preset time window is consistent with the communication duration requirement of the task parameters. When the communication duration requirement is longer, the preset time window is extended accordingly to ensure that the availability prediction covers the entire communication cycle of the command and control task.

[0075] The visible time window refers to a continuous time interval within a preset time window during which the elevation angle of a candidate satellite relative to the command and control terminal is not lower than the preset minimum visible elevation angle constraint and is not obscured by terrain. The start time of the visible time window is the moment when the candidate satellite enters the visible state, and the end time is the moment when the candidate satellite exits the visible condition. A candidate satellite may have zero or one or more visible time windows within the preset time window.

[0076] The duration of continuous coverage refers to the cumulative duration of all visible time windows of a candidate satellite within a preset time window. The duration of continuous coverage is used to characterize the total time that a candidate satellite can provide communication services to the command and control terminal within a preset time window. The longer the duration of continuous coverage, the higher the availability of the communication link corresponding to the candidate satellite within the preset time window.

[0077] The expected signal attenuation level refers to the normalized measure of path loss and atmospheric attenuation of the communication link corresponding to the candidate satellite within the visible time window, which is estimated based on the candidate satellite's ephemeris information, predicted motion trajectory, and link budget model. The expected signal attenuation level is used as a correction factor for the link quality score in subsequent link scoring. When the expected signal attenuation level is high, even if the link quality score is high, the overall score of the link will be lowered accordingly.

[0078] Specifically, the satellite availability prediction module 102, based on the command and control terminal location information, movement speed, and movement direction in the situational information, as well as the communication duration requirements in the mission parameters, filters and predicts the availability of available satellites within a preset future time window. The availability prediction results are used to support subsequent comprehensive link evaluation and handover decisions.

[0079] S103. Based on situational information and satellite availability prediction results, determine the comprehensive score of the communication link corresponding to at least one candidate satellite.

[0080] Specifically, the link comprehensive evaluation module 103 scores the communication link corresponding to each candidate satellite from four dimensions: link quality, availability, anti-interference, and service adaptation, based on the link quality, electromagnetic interference intensity, service requirements, and link availability duration in the situational information and availability prediction results. Then, it comprehensively obtains the comprehensive score of the communication link corresponding to each candidate satellite.

[0081] S104. Based on the comprehensive scoring results, and with the goal of optimizing business continuity and communication quality, generate link switching decisions.

[0082] Specifically, the handover decision module 104 calculates the handover cost and handover benefit based on the comprehensive score of the communication links corresponding to each candidate satellite and the comprehensive score of the current primary link, and generates a link handover decision.

[0083] S105. Based on the link switching decision, perform link switching while ensuring that the current service of the command and control terminal remains uninterrupted.

[0084] In one possible implementation, the switching execution module 105 pre-establishes a target link and synchronizes the context information of the current service based on the target link identifier included in the link switching decision. After the target link is established and the context information is synchronized, the service traffic is switched from the current primary link to the target link. After the switch is completed, the communication resources occupied by the current primary link are released.

[0085] S106. When the communication bandwidth requirement indicated by the service demand exceeds the bandwidth that the communication link corresponding to the candidate satellite with the highest comprehensive score can provide, at least two communication links shall be selected from at least one candidate satellite as an aggregated link set based on the continuous coverage duration and expected signal attenuation of each candidate satellite indicated by the availability prediction results.

[0086] Among them, the overlapping time period of continuous coverage duration of each link in the aggregated link set within the future preset time window is not less than the preset duration threshold, and the total available bandwidth of each link is not less than the communication bandwidth requirement.

[0087] Specifically, when the switching decision module 104 detects that the communication bandwidth requirement of the service demand exceeds the bandwidth that the communication link corresponding to the candidate satellite with the highest comprehensive score can provide, it triggers the aggregated link construction process. Based on the continuous coverage duration and expected signal attenuation of each candidate satellite in the availability prediction results, at least two communication links are selected from the candidate satellites. It is required that the continuous coverage duration of each selected link has an overlapping time period that is not shorter than a preset duration threshold, and the total available bandwidth of each selected link in the overlapping time period is not less than the communication bandwidth requirement of the service demand. The combination of links that meet the above conditions forms an aggregated link set.

[0088] In one embodiment, Figure 3 This is a flowchart illustrating the candidate satellite availability prediction process in a satellite communication command and control terminal intelligent handover method provided in an embodiment of this application. Figure 3 As shown, the above S102 specifically includes the following steps: S201. Based on the location information, movement speed, movement direction and communication duration requirements of the command and control terminal, determine the predicted movement trajectory of the command and control terminal within a future preset time window.

[0089] Specifically, the satellite availability prediction module 102 calculates the position of the command and control terminal at each time within a preset time window in the future based on the current position, speed and direction of the command and control terminal. The line connecting all the positions at all times is the predicted motion trajectory. When the motion state of the command and control terminal changes significantly, the predicted motion trajectory is regenerated according to the changed motion state.

[0090] For example, the preset time window length is one hour from now, and the time step is one minute; the predicted motion trajectory is a sequence of location points of the command terminal every minute in the next hour.

[0091] In one possible implementation, the satellite availability prediction module 102 uses a Kalman filter algorithm to predict the motion trajectory of the command and control terminal.

[0092] Specifically, a state vector X_k = [x, y, z, v_x, v_y, v_z]^T is constructed using the current position coordinates (longitude, latitude, altitude), speed, and direction of motion of the command and control terminal. The position of the command and control terminal at each moment within a preset time window is used as the observation. State transition equations and observation equations are established, and the predicted position and its confidence interval at each moment within the preset time window are obtained through recursive filtering.

[0093] When the motion state of the control terminal changes significantly, the state vector of the Kalman filter is reset, and the predicted motion trajectory is regenerated according to the changed motion state.

[0094] Optionally, when the speed of the command terminal is lower than a preset speed threshold, it is determined that the command terminal is in a near-stationary state, and the current position is directly used as the predicted motion trajectory without performing filtering recursion.

[0095] For example, the preset time window length is one hour from now, and the time step is one minute; the predicted motion trajectory is a sequence of location points of the command terminal every minute in the next hour, and each location point is accompanied by a confidence ellipse radius for error correction in subsequent availability prediction.

[0096] In another possible implementation, the satellite availability prediction module 102 uses a uniform linear motion model combined with acceleration compensation for trajectory prediction.

[0097] Specifically, the current position and velocity of the command and control terminal are obtained, as well as the velocity change sequence of the most recent N moments. The velocity change trend and average acceleration are calculated, and the position at each future moment is predicted according to the uniformly accelerated linear motion model.

[0098] When the inertial navigation unit carried by the command and control terminal can provide real-time acceleration information, the acceleration data can be directly read for trajectory prediction, further improving the prediction accuracy.

[0099] S202. Based on the predicted motion trajectory and the ephemeris information of the initial satellite, determine the elevation and azimuth sequences of at least one candidate satellite relative to the command and control terminal.

[0100] Specifically, the initial satellites include all on-orbit satellites within the visible range. The satellite availability prediction module 102 calculates the elevation and azimuth angles of each initial satellite relative to the command and control terminal at each moment based on the position of the command and control terminal at each moment in the predicted motion trajectory and the ephemeris information of the initial satellites, thus obtaining the elevation and azimuth sequence of each initial satellite.

[0101] Optionally, the initial satellite ephemeris information includes the orbital parameters of the GEO, MEO, and LEO satellites, including at least the semi-major axis, orbital inclination, right ascension of the ascending node, argument of perigee, mean perigee, and epoch time for each satellite.

[0102] For GEO satellites, ephemeris information is relatively fixed and can be updated daily; for MEO and LEO satellites, ephemeris information needs to be obtained in real time from the satellite control center or ground gateway according to the update cycle of the satellite navigation message (e.g., LEO satellites are updated every 30 seconds).

[0103] Optionally, when ephemeris information cannot be obtained in real time through a satellite communication link, the satellite availability prediction module 102 uses pre-loaded ephemeris backup data and combines it with a time extrapolation algorithm to perform epoch correction on the backup ephemeris in order to obtain an approximately accurate orbital position.

[0104] For example, the specific format of the ephemeris information is either the two-line root number (TLE) format or the extended ephemeris format.

[0105] Optionally, the satellite availability prediction module 102 first pre-screens the initial satellites based on the current position of the command and control terminal: only retains satellites whose minimum distance between the orbital nadir point trajectory and the predicted motion trajectory of the command and control terminal within the prediction time window is less than a preset distance threshold, and removes the remaining satellites in advance to reduce the amount of calculation for the elevation and azimuth sequences.

[0106] Optionally, the calculation period of the above elevation angle sequence and azimuth angle sequence is consistent with the time step of the predicted motion trajectory. That is, an elevation angle value and an azimuth angle value are calculated for each time step, and the elevation angle values ​​and azimuth angle values ​​of all time steps are arranged in chronological order to form the elevation angle sequence and azimuth angle sequence.

[0107] S203. Based on terrain shading features, identify at least one candidate satellite from the initial satellites.

[0108] Specifically, the satellite availability prediction module 102 filters the elevation angle sequence of each initial satellite according to the minimum visible elevation angle threshold corresponding to each terrain occlusion feature: the time in the elevation angle sequence that is lower than the minimum visible elevation angle threshold corresponding to the terrain occlusion feature is regarded as being occluded by the terrain; if an initial satellite is occluded by the terrain in all visible moments within a preset time window, it is removed from the initial satellites; the remaining initial satellites are the candidate satellites.

[0109] Optionally, the aforementioned terrain occlusion features are determined based on digital elevation model (DEM) data and the position of the predicted motion trajectory at each moment by the command and control terminal. Specifically, with the predicted position of the command and control terminal as the center and the azimuth direction of each initial satellite as the ray direction, the DEM data is used to determine whether there are obstacles higher than a preset height threshold in the ray direction. If there are, it is determined that the direction is occluded by the terrain at that moment.

[0110] Optionally, the aforementioned minimum visible elevation angle threshold is associated with terrain shading characteristics, and different minimum visible elevation angle thresholds are set for different terrain shading areas. For example, the minimum visible elevation angle threshold for flat and open terrain is 5°, the minimum visible elevation angle threshold for hilly terrain is 10°, and the minimum visible elevation angle threshold for mountainous areas is 15°.

[0111] Optionally, the aforementioned terrain shading features also include artificial building shading, which obtains building height and distribution information through pre-loaded 3D city model data.

[0112] S204. Based on the ephemeris information and predicted motion trajectory of at least one candidate satellite, determine the start time, end time, duration of continuous coverage, and path loss of the visible time window of at least one candidate satellite relative to the command and control terminal within a future preset time window.

[0113] Specifically, the satellite availability prediction module 102 extracts continuous time periods for each candidate satellite by combining the elevation angle sequence with terrain shading features and minimum available elevation angle constraints, thereby obtaining the start time, end time, and continuous coverage duration of each continuous visible time period of the candidate satellite within a future preset time window; at the same time, it calculates the corresponding path loss based on the distance of each candidate satellite relative to the command and control terminal at each time, the transmit power, the receive antenna gain, and the atmospheric attenuation model.

[0114] For example, the minimum available elevation angle is 10 degrees; the continuous coverage duration is the cumulative duration of all visible moments within the continuous visible period; the path loss is calculated based on the free space propagation loss model and superimposed with atmospheric absorption loss.

[0115] In one possible implementation, the above-mentioned continuous time period extraction specifically involves: for each candidate satellite's elevation angle sequence, traversing each moment in chronological order, and merging consecutive moments whose elevation angle values ​​simultaneously satisfy the following two conditions into a single continuous visible time period: The elevation angle value is not lower than the minimum available elevation angle threshold; features not obscured by terrain are considered as obscured.

[0116] The start time of each continuous visible period is the first time when the condition is met, and the end time is the last time when the condition is met. The duration of continuous coverage is the difference between the end time and the start time.

[0117] When the time interval between two consecutive visible periods is less than a preset merging threshold, the two periods are merged into one consecutive visible period to avoid the visible time window being too fragmented due to brief occlusion.

[0118] Specifically, the aforementioned preset merging threshold is dynamically determined based on the movement speed of the command and control terminal, including: When the speed of the control terminal is lower than the preset speed threshold, it is determined that the terminal is in a low-speed movement state. At this time, the time required for the terminal to pass through the same terrain-blocked area is longer, and the visible time interval caused by terrain blockage during the passage of the same satellite is longer. Therefore, the preset merging threshold is set as the first threshold to merge multiple visible time intervals formed by the short-term terrain blockage of the same satellite into a continuous available time window, so as to avoid fragmentation of availability prediction results. When the speed of the control terminal is higher than or equal to the preset speed threshold, it is determined that the terminal is in a high-speed movement state. At this time, the terminal quickly passes through the terrain obstruction area. The visible time interval caused by the terrain obstruction is short. Moreover, the satellite elevation angle change rate increases and the transit time is shortened under high-speed movement. The preset merging threshold is set as the second threshold to prevent the erroneous merging of the actual transit time of different satellites or the transit time of different orbits of the same satellite, so as to ensure the accuracy of the availability prediction results. The first threshold is greater than the second threshold.

[0119] Optionally, the aforementioned preset merging threshold is also related to the orbit type of the candidate satellite: for LEO satellites, since the interval between adjacent transits is usually between 90 and 120 minutes, even if the threshold is set to 30 seconds in a high-speed scenario, it is not enough to cross the actual transit interval; for GEO satellites, since they are almost stationary relative to the command and control terminal, a larger threshold can be used to directly merge all continuous visible time periods.

[0120] For example, when the satellite orbit type is LEO, the preset speed threshold is 2m / s, the first threshold is 90 seconds, and the second threshold is 15 seconds; when the satellite orbit type is MEO, the preset speed threshold is 1.5m / s, the first threshold is 120 seconds, and the second threshold is 30 seconds; when the satellite orbit type is GEO, since GEO satellites are continuously visible and there is no issue of distinguishing between different transits, the preset merging threshold is fixed at 300 seconds.

[0121] Optionally, the aforementioned preset merging threshold is also dynamically adjusted according to the distribution density of terrain occlusion features: when the terrain occlusion features indicate that the current location of the terminal is a densely built-up area or mountainous area, terrain occlusion is frequent and highly random, so the preset merging threshold is reduced to avoid incorrectly merging visible time periods that are not from the same transit; when the terrain occlusion features indicate that the location of the terminal is an open and flat area, terrain occlusion is sparse and highly regular, so the preset merging threshold is increased to fully merge short-lived occlusion fragments from the same satellite transit.

[0122] The path loss is calculated as follows: based on the spatial distance d of each candidate satellite relative to the command and control terminal at each time, combined with the free space propagation loss formula, and then superimposed with atmospheric absorption loss, rainfall attenuation and tropospheric scintillation attenuation, the total path loss is obtained.

[0123] It should be understood that the aforementioned free-space propagation loss refers to the energy diffusion loss caused by wavefront expansion when electromagnetic waves propagate in a vacuum environment. Its magnitude is related to the propagation distance and operating frequency; the greater the propagation distance or the higher the operating frequency, the greater the free-space propagation loss. In the actual atmospheric environment, electromagnetic waves are absorbed by atmospheric gas molecules along their propagation path, resulting in atmospheric absorption loss. This loss is mainly caused by the resonant absorption of oxygen and water vapor molecules. Its impact is relatively small near sea level and in the low-frequency band, but significantly increases in the high-frequency band, especially the Ka-band and millimeter-wave band. Furthermore, atmospheric absorption loss is related to the elevation angle; the lower the elevation angle, the longer the atmospheric path traversed by the electromagnetic wave, and the greater the atmospheric absorption loss.

[0124] The aforementioned tropospheric scintillation attenuation refers to the phenomenon that when electromagnetic waves propagate in the troposphere, the amplitude and phase of the received signal fluctuate rapidly due to the random fluctuations in atmospheric refractive index with temperature, humidity, and air pressure. This attenuation mainly affects satellite communication links at low elevation angles. Tropospheric scintillation attenuation is relatively weak under clear and light wind conditions, but it is significantly enhanced under cloudy, windy, or severe convective weather conditions.

[0125] The aforementioned rainfall attenuation refers to the signal energy loss caused by the absorption and scattering of electromagnetic waves by raindrops when electromagnetic waves pass through a rainfall area. Its magnitude is closely related to the rainfall intensity, electromagnetic wave frequency, and polarization mode. The higher the frequency and the greater the rainfall intensity, the greater the rainfall attenuation. In the Ka-band and millimeter-wave band, rainfall attenuation is a major loss factor that cannot be ignored in the link budget.

[0126] Optionally, the environmental parameters (atmospheric temperature, humidity, air pressure, rainfall intensity, etc.) used in the calculation of the above losses can be collected in real time by the meteorological sensors mounted on the command and control terminal, or obtained by accessing local meteorological service data.

[0127] Optionally, when real-time environmental parameters are lacking, the regional average parameters in the corresponding climate model recommended by ITU-R can be used for approximate calculation, and the calculation results can be labeled as estimated values ​​for the link integrated assessment module to perform weighted processing based on confidence level.

[0128] S205. Based on the start and end times of the visible time window, the duration of continuous coverage, and the path loss of at least one candidate satellite relative to the command and control terminal within a future preset time window, determine the availability prediction result.

[0129] Specifically, the satellite availability prediction module 102 summarizes the start and end times of the visible time window, the duration of continuous coverage, and the path loss of each candidate satellite in the future preset time window in chronological order to form the availability prediction result of that candidate satellite; the set of availability prediction results of all candidate satellites is the availability prediction result output for this prediction.

[0130] In one possible implementation, the satellite availability prediction module 102 encapsulates the availability prediction result of each candidate satellite into a prediction result data structure.

[0131] The above data structure includes at least: satellite identifier (satellite name or number), satellite orbit type (GEO / MEO / LEO), total number of visible time periods, start and end times of each visible time period (in UTC time), duration of continuous coverage within each visible time period (in seconds), path loss value sequence corresponding to each time within each visible time period (in dB), and minimum path loss, maximum path loss, and average path loss within each visible time period.

[0132] The prediction results of all candidate satellites are sorted from high to low according to the comprehensive availability score (calculated based on a weighted combination of continuous coverage duration and average path loss) and output to form the availability prediction results for this prediction.

[0133] Optionally, the prediction results data structure also includes the elevation angle sequence of each candidate satellite at each time point within each visible period, which is used by the subsequent link comprehensive evaluation module for refined scoring.

[0134] Optionally, the above availability prediction results are stored in the local cache of the command and control terminal in JSON format or binary protocol format, and simultaneously reported to the cloud command and control center through the backhaul link for reference by the cloud in making global communication resource scheduling decisions.

[0135] Figure 4 This is a schematic diagram illustrating the communication link comprehensive scoring process in a satellite communication command and control terminal intelligent handover method provided in an embodiment of this application. Figure 4 As shown, the above S103 specifically includes the following steps: S301. Based on the signal strength, signal-to-noise ratio, bit error rate, and link delay of the communication link corresponding to at least one candidate satellite, determine the link quality score of at least one candidate satellite.

[0136] Specifically, the link comprehensive evaluation module 103 normalizes the signal strength, signal-to-noise ratio, bit error rate, and link delay of the communication link corresponding to each candidate satellite, and then sums them according to preset weights to obtain the link quality score of the candidate satellite; among which, the higher the signal strength, the higher the signal-to-noise ratio, the lower the bit error rate, and the lower the link delay, the higher the link quality score.

[0137] For example, the link quality score is a dimensionless value in the interval [0,1]; the signal strength normalization score is the ratio of the measured signal strength to the full-scale signal strength; the signal-to-noise ratio normalization score is the ratio of the measured signal-to-noise ratio to the full-scale signal-to-noise ratio; the bit error rate normalization score is 1 minus the ratio of the measured bit error rate to the full-scale bit error rate; and the link delay normalization score is 1 minus the ratio of the measured link delay to the full-scale link delay.

[0138] S302. Based on the satellite availability prediction results, determine the link availability duration score of at least one candidate satellite.

[0139] Specifically, the link comprehensive evaluation module 103 determines the link availability duration score of each candidate satellite based on the continuous coverage duration of each consecutive visible period in the availability prediction results of each candidate satellite, according to the principle that the longer the continuous coverage duration, the higher the score.

[0140] For example, the link availability time score is the ratio of continuous coverage time to a preset full-scale coverage time; the preset full-scale coverage time is a preset time window length.

[0141] S303. Based on the electromagnetic interference intensity, determine the anti-interference capability score of at least one candidate satellite.

[0142] Specifically, the link comprehensive evaluation module 103 determines the anti-interference capability score of each candidate satellite based on the electromagnetic interference intensity of the frequency band in which the candidate satellite is located, according to the principle that the lower the electromagnetic interference intensity, the higher the anti-interference capability score.

[0143] For example, the anti-interference capability score is calculated by subtracting the ratio of the electromagnetic interference intensity to the preset full-scale interference intensity from 1; when the electromagnetic interference intensity is higher than the preset full-scale interference intensity, the anti-interference capability score is 0.

[0144] S304. Based on the service type and service quality requirement level, determine the service compatibility score of at least one candidate satellite.

[0145] Specifically, the link comprehensive evaluation module 103 determines the service adaptability score of the candidate satellite based on the degree of matching between the service type and the service type supported by each candidate satellite, and the degree of matching between the service quality requirement level and the service quality level that the candidate satellite can provide.

[0146] For example, the service type matching score is the ratio of the number of service type matching items supported by the candidate satellite to the total number of service requirements; the service quality requirement level matching score is the ratio of the service quality level provided by the candidate satellite to the service quality requirement level of the service requirements; and the service adaptability score is a weighted sum of the service type matching score and the service quality requirement level matching score.

[0147] S305. Based on the link quality score, link availability duration score, anti-interference capability score, and service adaptability score of at least one candidate satellite, determine the comprehensive score of the communication link corresponding to at least one candidate satellite.

[0148] Specifically, the link comprehensive evaluation module 103 calculates the comprehensive score of the communication link corresponding to each candidate satellite by weighting the link quality score, link availability score, anti-interference capability score, and service adaptability score according to the dynamic weight coefficients. The dynamic weight coefficients are dynamically determined based on the priority level of the current command and control mission indicated by the mission parameters and the service type indicated by the service requirements.

[0149] The correspondence between dynamic weighting coefficients and task parameters and business requirements is as follows: When the service type is a command and control instruction service, the weight coefficient corresponding to the service adaptability score is the largest. For example, the weight coefficient corresponding to the service adaptability score is 0.4, the weight coefficients corresponding to the link quality score and the link availability time score are each 0.2, and the weight coefficient corresponding to the anti-interference capability score is 0.2.

[0150] When the priority level indicated by the task parameters is higher than the preset level threshold, the weight coefficients corresponding to the link quality score and the link availability time score increase dynamically over time, and the increase is positively correlated with the cumulative motion distance in the predicted motion trajectory of the command and control terminal. For example, the preset level threshold is high priority. The larger the cumulative motion distance, the greater the increase in the weight coefficients corresponding to the link quality score and the link availability time score, so as to adapt to the focus on future visibility in high dynamic and high priority scenarios.

[0151] Optionally, the aforementioned preset level thresholds are determined based on the task priority classification system.

[0152] For example, when a three-level priority system is adopted, level 1 is the highest priority, level 2 is the medium priority, and level 3 is the normal priority. The preset level threshold is set to level 2, that is, only level 1 tasks trigger the link quality score and link availability time score, and the weight of these scores increases dynamically over time.

[0153] When a five-level priority system is adopted, the preset level threshold is set to level 3, meaning that level 1 and level 2 tasks trigger the aforementioned dynamic weight increase mechanism. The preset level threshold can be pre-configured by the task planning system, set by the operator through a human-computer interaction interface, or automatically mapped by the system according to the business type.

[0154] When the electromagnetic interference intensity indicated by the environmental conditions is higher than the preset intensity threshold, the weighting coefficient corresponding to the anti-interference capability score increases; for example, the preset intensity threshold is a medium interference intensity; when the electromagnetic interference intensity exceeds the preset intensity threshold, the weighting coefficient corresponding to the anti-interference capability score is increased from the base value to the first increased value.

[0155] Optionally, the aforementioned preset strength threshold is determined jointly based on the operating frequency band and link budget of the satellite communication link.

[0156] For example, when the aforementioned command and control terminal operates in the Ka band, with a receiver noise floor of -100 dBm and a link budget margin of 15 dB, the preset strength threshold is set to -95 dBm (i.e., 5 dB above the noise floor). When the in-band electromagnetic interference intensity is below this threshold, the impact of interference on communication quality is within an acceptable range; when the interference intensity is above this threshold, the communication quality degrades to an unacceptable level, requiring an increase in the weight of the anti-interference capability score in the overall score. The preset strength threshold can be determined by the value specified in the electromagnetic compatibility standard, or by 50% to 70% of the link budget margin, or by statistical analysis of historical interference data.

[0157] For example, in one possible implementation, the dynamic weighting coefficients are determined as follows: Let the basic weight vector be ,in The basic weight coefficients corresponding to the link quality score, link availability score, anti-interference capability score, and service adaptability score, respectively, and satisfy the following conditions: .

[0158] Cumulative distance That is, the total distance that the command terminal has moved along the trajectory from the start time 0 of the mission to the current time t.

[0159] When the priority level of the command and control task is higher than the preset level threshold, the weight coefficients corresponding to the link quality score and link availability time score increase proportionally with the cumulative movement distance: ; Where Dref is the preset maximum reference distance (for example, Dref=vmax×Ttotal, vmax is the maximum movement speed of the command terminal, and Ttotal is the communication duration requirement indicated by the task parameters), λp is the preset upper limit of adjustment (for example, λp=0.20), and the min(·) function is used to limit the weight increase to no more than λp.

[0160] When the electromagnetic interference intensity indicated by the environmental conditions exceeds a preset intensity threshold, the weighting coefficient corresponding to the anti-interference capability score increases by the following amount: ; Where I is the current electromagnetic interference intensity, Ith is the preset intensity threshold, and λa is the preset upper limit of adjustment range (for example, λa=0.15). When I≤Ith, the adjustment range is 0.

[0161] The adjusted unnormalized weights are:

[0162] After normalization, the final weight coefficients of each scoring item at each time point are obtained: wi(t)=wiraw / (wqraw+wdraw+waraw+wsraw), i∈{q,d,a,s} Therefore, the weight coefficients of each scoring item are adaptively and dynamically adjusted over time, and Σwi(t)=1 always holds true, ensuring that the comprehensive score has consistent dimensions and comparability at all times.

[0163] Figure 5 This is a flowchart illustrating the link switching decision-making process in a satellite communication command and control terminal intelligent switching method provided in an embodiment of this application. Figure 5 As shown, the above S104 specifically includes the following steps: S401. Obtain the comprehensive score of the communication link corresponding to each candidate satellite and sort them from high to low.

[0164] Specifically, the switching decision module 104 sorts the comprehensive scores of the communication links corresponding to each candidate satellite in descending order to obtain a comprehensive score ranking sequence.

[0165] S402. Determine the overall score ranking corresponding to the current primary link, and determine the target link based on the overall score ranking.

[0166] Specifically, the switching decision module 104 inserts the candidate satellites corresponding to the current primary link into the comprehensive score ranking sequence to determine the comprehensive score ranking corresponding to the current primary link.

[0167] When the communication link corresponding to the top-ranked candidate satellite is the same as the current primary link, the target link remains the current primary link and no switch is triggered; when the communication link corresponding to the top-ranked candidate satellite is different from the current primary link, proceed to S403.

[0168] S403. Calculate the switching cost from the current primary link to the communication link corresponding to the top-ranked candidate satellite.

[0169] Specifically, the switching decision module 104 calculates the switching cost of switching from the current primary link to the communication link corresponding to the top-ranked candidate satellite.

[0170] The aforementioned switching costs include three dimensions: switching latency, signaling overhead, and frequency resource usage, as well as indications of whether the satellite orbit types before and after the switching are the same.

[0171] The aforementioned handover latency refers to the end-to-end latency from the issuance of the handover decision to the completion of the handover execution, including target link establishment latency, context synchronization latency, and traffic switching latency. The greater the handover latency, the higher the risk of service interruption during the handover process.

[0172] The aforementioned signaling overhead refers to the number of signaling interactions and the amount of signaling data required to complete this handover. The greater the signaling overhead, the more communication resources are consumed.

[0173] The frequency resource occupancy mentioned above refers to the amount of frequency bandwidth resources required after the target link is established. The greater the frequency resource occupancy, the more frequency resources are consumed in the system.

[0174] The aforementioned orbit type adaptation cost refers to the additional adaptation cost introduced by the difference in satellite orbit types before and after the switch, and is characterized by indication information on whether the satellite orbit types before and after the switch are the same.

[0175] When the satellite orbit types before and after the handover are different (e.g., switching from GEO to LEO, or from LEO to MEO), the handover process requires additional protocol adaptation, frequency calibration, and beam alignment operations due to significant differences in orbital altitude, motion characteristics, propagation delay, Doppler shift, beam coverage, and handover protocol procedures. Therefore, the adaptation cost is higher than that for handovers within the same orbit type. When the satellite orbit types before and after the handover are the same (GEO-GEO, MEO-MEO, or LEO-LEO), the adaptation cost is relatively low.

[0176] For example, the handover decision module 104 first normalizes the three dimensions of handover delay, signaling overhead and frequency resource occupation, converts the original dimensions of each dimension into dimensionless values ​​in the interval [0,1], and then weights and sums the three normalized values ​​to obtain the basic handover cost.

[0177] The weights of each dimension can be dynamically adjusted according to current business needs: when the business type is command and control service, the switching latency dimension is given a higher weight to ensure the real-time transmission of commands; when the system signaling channel is congested, the signaling overhead dimension is given a higher weight to avoid increasing the burden on the signaling channel.

[0178] Then, the switching decision module 104 determines the value of the orbit type adaptation cost based on whether the satellite orbit types before and after the switch are the same: when the satellite orbit types before and after the switch are the same, the orbit type adaptation cost is 0; when the satellite orbit types before and after the switch are different, the orbit type adaptation cost is a preset penalty coefficient. This preset penalty coefficient is a positive number, and its specific value is positively correlated with the degree of protocol difference between different orbit types. That is, the greater the difference between orbit types, the higher the penalty coefficient when switching.

[0179] Finally, the switching decision module 104 adds the basic switching cost to the track type adaptation cost to obtain the final switching cost.

[0180] For example, the switching cost is represented by a normalized value, which is a dimensionless value in the range [0,1].

[0181] Optionally, the weights of each dimension in the weighted summation of the switching costs mentioned above are also dynamically adjusted according to the current motion state of the command and control terminal: when the command and control terminal is in a high-speed motion state, the weight of the frequency resource occupancy dimension is reduced because the Doppler frequency shift changes rapidly under high-speed motion, the stable occupancy time of frequency resources is short, and the reference value of frequency resource occupancy decreases.

[0182] Optionally, the aforementioned preset penalty coefficients are set according to the specific combination of track types before and after the switch. For example, the switching penalty coefficient between GEO and LEO is 0.25, the switching penalty coefficient between GEO and MEO is 0.15, and the switching penalty coefficient between LEO and MEO is 0.10.

[0183] S404. Based on the difference between the comprehensive score of the communication link corresponding to the top-ranked candidate satellite and the comprehensive score of the current primary link, and in conjunction with the handover cost, determine the handover benefit.

[0184] Specifically, the switching decision module 104 calculates the difference between the comprehensive score of the communication link corresponding to the top-ranked candidate satellite and the comprehensive score of the current primary link, thus obtaining the comprehensive score difference. This comprehensive score difference reflects the expected improvement in communication quality after switching to the top-ranked candidate satellite; a larger difference indicates a more significant improvement in communication quality after the switch.

[0185] The handover decision module 104 determines whether the handover conditions are met based on the comprehensive score difference, the handover cost, and the preset handover threshold. The communication link corresponding to the top-ranked candidate satellite is determined as the target link, and a handover decision to switch to the target link is generated only if all of the following conditions are met: Condition 1: The overall score difference is greater than the preset score difference threshold; the preset score difference threshold is dynamically determined according to the current service type. When the service type is a command and control instruction service, the preset score difference threshold is higher than the threshold value of non-command and control instruction services, so as to avoid high-priority services from switching frequently due to minor quality fluctuations. Condition 2: The switching delay does not exceed a preset delay threshold; the preset delay threshold is dynamically determined according to the current service type. When the service type is a command and control service or a voice service, the preset delay threshold is lower than the threshold value for non-real-time services to ensure the continuity and service quality of high real-time services. Condition 3: The signaling overhead does not exceed a preset signaling threshold; the preset signaling threshold is dynamically determined based on the current load status of the system signaling channel. When the signaling channel load is higher than the preset load threshold, the preset signaling threshold is lowered to avoid aggravating channel congestion due to signaling handover. Condition 4: The frequency resource usage does not exceed a preset frequency resource threshold; the preset frequency resource threshold is dynamically determined based on the total amount of available frequency resources in the system. When available frequency resources are insufficient, the preset frequency resource threshold is lowered to ensure the reasonable allocation of frequency resources.

[0186] Furthermore, when the satellite orbit types before and after the switch are different, the preset score difference threshold is switched to a second score difference threshold, which is higher than the first score difference threshold.

[0187] For example, when the service type is a non-command instruction service, the preset score difference threshold for switching within the same track type is 0.05, and the preset score difference threshold for switching across track types is increased to 0.15, meaning that switching across tracks requires a greater improvement in communication quality to be worthwhile.

[0188] For example, when the service type is a command and control instruction service, the preset score difference threshold for switching within the same track type is 0.08, and the preset score difference threshold for switching across track types is increased to 0.20.

[0189] In another possible implementation, the handover decision module 104 first calculates the time decay coefficient β of the handover benefit based on the remaining visible duration Tvisibleremain and the estimated handover delay Thandover of the current primary link in the availability prediction results: ; Where γ is a preset attenuation coefficient (for example, γ=0.5). When Tvisibleremain ≤ Thandover, β=0, that is, the current primary link has lost its lock before the handover is completed and the handover should not be performed.

[0190] The switching decision module 104 calculates the difference between the comprehensive score of the communication link corresponding to the candidate satellite ranked first and the comprehensive score of the current primary link, and obtains the comprehensive score difference ΔS.

[0191] The switching benefit G = β×ΔS−Chandover, where Chandover is the normalized value of the switching cost calculated in S403.

[0192] Furthermore, when the handover decision module 104 detects that the current primary link has experienced a sudden interruption (i.e., the link quality parameters are lower than the preset interruption threshold), it does not perform the above handover benefit calculation, but instead performs an emergency handover determination: if the expected link layer recovery time Trecoverexpected is greater than the sum of the estimated handover delay Thandover and the preset tolerance threshold Tthreshold, then an emergency handover is triggered; otherwise, it waits for the link layer to recover quickly and does not trigger a handover.

[0193] When the handover benefit G is greater than the preset handover threshold and no sudden interruption occurs in the current primary link, the communication link corresponding to the candidate satellite ranked first is determined as the target link, and a handover decision to hand over to the target link is generated.

[0194] S405. When the handover benefit is greater than the preset handover threshold, the communication link corresponding to the candidate satellite ranked first is determined as the target link, and a handover decision to hand over to the target link is generated.

[0195] The handover decision module 104 sends the generated link handover decision to the handover execution module 105, which then executes the steps of S105.

[0196] In one embodiment, S105 specifically includes the following steps: S601. Obtain the target link identifier indicated in the link switching decision, and initiate a link establishment request to the target satellite corresponding to the target link based on the target link identifier.

[0197] Specifically, the switching execution module 105 extracts the target link identifier from the link switching decision and initiates a link establishment request to the target satellite corresponding to the target link based on the target link identifier; after receiving the link establishment request, the target satellite performs signaling interaction and completes the establishment of the target link.

[0198] S602. Synchronize the context information of the current service between the target link and the current primary link.

[0199] The context information includes at least the IP address mapping relationship of the current session, the transport layer connection status, the data packet sequence number, and the application layer session status.

[0200] Specifically, before the target link is established, the switching execution module 105 establishes a context synchronization channel between the target link and the current primary link in advance, and synchronizes the IP address mapping relationship of the current service, the transport layer connection status, the allocated data packet sequence number and the application layer session status on the current primary link to the target link side.

[0201] S603. After the target link is established and the context information is synchronized, the service traffic will be switched from the current primary link to the target link.

[0202] Specifically, after confirming that the target link has been established and the context information has been synchronized, the switching execution module 105 smoothly switches the current service traffic from the current primary link to the target link. During the switching process, the application layer session remains continuous, the transport layer connection is not interrupted, and no data packets are lost.

[0203] S604. After the switchover is complete, release the communication resources currently occupied by the primary link.

[0204] Specifically, after all service traffic is switched to the target link, the switching execution module 105 releases the frequency resources, channel resources, and signaling resources currently occupied by the primary link, thus completing this link switch.

[0205] In one embodiment, the above-mentioned S106 and subsequent steps specifically include the following steps: S701. Obtain the real-time bandwidth, latency, packet loss rate, and expected signal attenuation trend of each link in the aggregated link set during the overlapping time period.

[0206] Specifically, the switching execution module 105 collects the real-time bandwidth, latency, and packet loss rate of each link in the aggregated link set during the overlapping time period, and generates the expected signal attenuation trend of each link in chronological order based on the expected signal attenuation degree of each link at each moment during the overlapping time period in the availability prediction results.

[0207] S702. Based on real-time bandwidth, latency, packet loss rate, and expected signal attenuation trend, determine the dynamic traffic splitting weight of each link at each moment within the overlapping time period.

[0208] Specifically, the switching execution module 105 obtains the real-time bandwidth, latency, packet loss rate, and expected signal attenuation trend of each link in the aggregated link set at each moment within the overlapping time period, and uses the parameters of the above four dimensions as input for the calculation of the traffic splitting weight to determine the dynamic traffic splitting weight of each link at each moment within the overlapping time period.

[0209] The aforementioned dynamic traffic splitting weight represents the proportion of data splitting undertaken by each link in the aggregated transmission. The sum of the dynamic traffic splitting weights of all links is normalized to 1 at the same time. The larger the dynamic traffic splitting weight, the more service data that link is allocated at that time.

[0210] It should be understood that the aforementioned dynamic traffic splitting weight is the core parameter of the aggregation transmission mechanism, which directly determines the amount of business data each link undertakes per unit time. The larger the weight, the more data packets the link is allocated in the same time period.

[0211] For example, if at a certain moment the dynamic traffic splitting weight of link A is 0.5, link B is 0.3, and link C is 0.2, then at that moment, out of 100 data packets to be transmitted, approximately 50 will be allocated to link A, 30 to link B, and 20 to link C, and the three links will simultaneously send their respective allocated data.

[0212] It should be noted that this weight is only a numerical basis for data allocation. The physical transmission rate of each link is determined by its own radio frequency bandwidth and modulation and coding method. The above dynamic traffic allocation weight ensures the allocation ratio of the service data volume undertaken by each link, rather than direct control of the physical transmission rate. Each link's transmission queue independently consumes the data in its own queue according to its own physical rate. The weight allocation and the actual transmission rate together determine the queue status and transmission efficiency of each link.

[0213] It should also be understood that the dynamic traffic splitting weights mentioned above differ from the comprehensive score used for link switching decisions in S4. The comprehensive score is used to evaluate the overall quality of each link and select the optimal link; it is the basis for determining "which link to select." In contrast, the dynamic traffic splitting weights are used to determine the data volume allocation ratio among multiple links in aggregated transmission mode; they are the operational parameters for "how much data each link handles." The comprehensive score directly determines whether a link is selected into the aggregated link set and its initial weight after selection. The dynamic traffic splitting weights, however, further refine the adjustment based on the comprehensive score and real-time parameters—links with higher comprehensive scores, larger real-time bandwidth, lower latency and packet loss rates, and less expected signal attenuation are assigned higher dynamic traffic splitting weights and handle more data.

[0214] It should also be understood that the "dynamic" characteristic of the aforementioned dynamic traffic splitting weight is reflected in its time-varying attributes. Since the real-time bandwidth, latency, packet loss rate, and expected signal attenuation of each link change in real time with factors such as link status, terminal location, and environmental conditions, the dynamic traffic splitting weight of each link at each moment is also dynamically adjusted accordingly. This dynamic adjustment mechanism enables aggregated transmission to continuously adapt to changes in the communication environment—for example, when the real-time bandwidth of a link decreases, its dynamic traffic splitting weight decreases accordingly, and the system automatically splits more data to other links with better quality; when the expected signal attenuation of a link will exceed the attenuation threshold at some future moment, the system begins to gradually reduce the weight of that link at the current moment, achieving a forward-looking adjustment of the traffic splitting strategy.

[0215] Optionally, when the dynamic traffic splitting weight is allocated using the number of data packets as the granularity, the number of data packets allocated to each link is determined by multiplying the weight ratio by the total number of data packets to be sent and then rounding down. The remaining fractional part, which is less than one data packet, is allocated to the link with the highest weight.

[0216] Optionally, when the above dynamic traffic splitting weight is allocated in bytes, the amount of data allocated to each link is determined by multiplying the weight ratio by the total number of bytes of data to be sent, and each link encapsulates the allocated data bytes into a data packet suitable for its own link MTU size for independent transmission.

[0217] The switching execution module 105 determines the dynamic traffic splitting weight of each link at each time point, specifically through the following methods: First, the switching execution module 105 performs normalized scoring on the real-time bandwidth, latency, and packet loss rate of each link at each time point. Specifically, the normalized score for real-time bandwidth is determined by the proportion of each link's real-time bandwidth to the total bandwidth of the aggregated link set; the higher the real-time bandwidth, the higher the normalized bandwidth score. The normalized score for latency is mapped to the [0,1] interval after sorting latency values ​​from low to high; the lower the latency, the higher the normalized latency score. The normalized score for packet loss rate is mapped to the [0,1] interval after sorting packet loss rates from low to high; the lower the packet loss rate, the higher the normalized packet loss rate score.

[0218] Secondly, the switching execution module 105 performs a weighted summation of the normalized scores of the above three dimensions to obtain the basic traffic distribution weight of each link at each time point. The weight of each dimension in the above weighted summation is dynamically determined according to the current service type: when the service type is video service, the packet loss rate dimension has a higher weight to ensure video picture quality; when the service type is voice service, the latency dimension has a higher weight to ensure the real-time performance of voice calls; when the service type is data service, the bandwidth dimension has a higher weight to improve data transmission efficiency.

[0219] Then, the switching execution module 105 corrects the basic diversion weights according to the expected signal attenuation trend of each link at each time, so as to obtain the dynamic diversion weights of each link at each time.

[0220] Specifically, when the expected signal attenuation of a link in a future time after the current time exceeds a preset attenuation threshold, before that future time arrives, the switching execution module 105 reduces the basic traffic splitting weight of that link in advance. The reduction is positively correlated with the difference between the expected signal attenuation and the preset attenuation threshold—the greater the expected signal attenuation exceeds the preset attenuation threshold, the greater the reduction in the dynamic traffic splitting weight of that link in the corresponding future time. Simultaneously, the reduced weight is redistributed to other links in the aggregated link set according to the normalized bandwidth score ratio, so as to keep the sum of the dynamic traffic splitting weights of all links in the aggregated link set always equal to 1.

[0221] Based on the above technical means, the expected signal attenuation trend is used to achieve "proactive adjustment" of the traffic offloading weight: for links that are predicted to experience severe signal attenuation, their traffic offloading weight in the future is reduced in advance to avoid a large amount of data loss or need to be retransmitted when the link actually attenuates, rather than passively responding after the signal attenuation occurs.

[0222] For example, suppose the aggregated link set includes link A, link B, and link C. At a future time t, the basic traffic splitting weights of the three links are 0.50, 0.30, and 0.20, respectively. If, based on the expected signal attenuation trend, the expected signal attenuation of link A at that time exceeds the preset attenuation threshold, and the excess is significant, then the switching execution module 105 reduces the dynamic traffic splitting weight of link A at that time from 0.50 to 0.20. The reduced weight of 0.30 is then allocated according to the normalized bandwidth score ratio of link B and link C. Assuming link B is allocated 0.18 and link C is allocated 0.12, then the dynamic traffic splitting weight of link B at that time becomes 0.48, and link C becomes 0.32. The sum of the three is normalized to 1.

[0223] Optionally, the aforementioned preset attenuation threshold is associated with the service type: when the service type is a command and control service or a video service, the preset attenuation threshold is lower (e.g., if the expected signal attenuation exceeds 3dB, the weight reduction is triggered) to ensure that high-reliability services are not damaged by link attenuation; when the service type is a data service, the preset attenuation threshold is higher (e.g., if the expected signal attenuation exceeds 6dB, the weight reduction is triggered) to maximize bandwidth utilization while ensuring transmission reliability.

[0224] S703: Based on the dynamic traffic distribution weights corresponding to each time moment, the service data is distributed to each link in the aggregated link set for parallel transmission.

[0225] Specifically, the switching execution module 105 allocates the service data packets to be transmitted according to the dynamic diversion weight of each link at each time within the overlapping time period determined in S702, and sends them simultaneously through each link in the aggregated link set to achieve parallel transmission of multiple links.

[0226] It should be understood that the aforementioned dynamic traffic splitting weight is the proportion of data traffic splitting undertaken by each link in the aggregated transmission. The switching execution module 105 divides the service data into multiple data sub-streams according to this proportion, and assigns them to each link in the aggregated link set for independent transmission. Each link transmits its assigned data sub-stream, and all links work simultaneously within the same time period to jointly complete the transmission task of all service data.

[0227] In one possible implementation, the switching execution module 105 allocates data packets at the granular level.

[0228] Specifically, the switching execution module 105 maintains the sending queue corresponding to each link. When a data packet to be transmitted arrives, it determines the number of data packets or the proportion of data volume that each link should bear based on the dynamic diversion weight of each link at the current time, and distributes the data packets to the sending queue corresponding to each link in sequence.

[0229] For example, suppose that at a certain moment, the dynamic traffic splitting weights of link A, link B, and link C are 0.50, 0.30, and 0.20, respectively, and there are 100 data packets to be transmitted. Then the switching execution module 105 will allocate 50 data packets to the sending queue of link A, 30 data packets to the sending queue of link B, and 20 data packets to the sending queue of link C. The three links will simultaneously send the data packets in their respective queues.

[0230] It should be understood that the physical transmission rates of each link are different, and the consumption speed of the sending queue is also different. The switching execution module 105 dynamically adjusts the data packet allocation strategy at subsequent times based on the actual transmission rate of each link and the real-time feedback of the link status, so as to ensure that the sending queue of each link is neither idle nor overloaded.

[0231] In another possible implementation, the switching execution module 105 allocates data at the data block level. Specifically, for continuous media data such as video streams, the switching execution module 105 divides the continuous data stream into data blocks of different sizes according to the dynamic distribution weight of each link. Each data block is marked with a sequence number and a timestamp and then distributed to each link for independent transmission. The receiving end sorts and reassembles the data blocks arriving from each link according to the sequence number, restoring the original data stream.

[0232] It should be understood that due to the different transmission delays of each link, the order in which data blocks transmitted on different links arrive at the receiving end may be inconsistent with the sending order. The receiving end needs to perform buffer sorting according to the sequence number carried by the data blocks, and reassemble them in order after all data blocks are received to restore the original business data.

[0233] In one possible implementation, when a link in the aggregated link set is about to fail due to signal attenuation or exceeding coverage range, the handover execution module 105 has already reduced the dynamic traffic allocation weight of that link in S702. Therefore, the amount of data to be transmitted on that link has been reduced in advance. The handover execution module 105 then redistributes the reduced data amount to other links, ensuring that the number of data packets accumulated in the transmission queue of that link has been reduced to a minimum before it fails, thereby avoiding a large amount of data retransmission or loss due to link failure. When the link completely exits the aggregated link set, the handover execution module 105 normalizes the dynamic traffic allocation weight of the remaining links back to 1 and continues to allocate service data among the remaining links, achieving uninterrupted aggregated transmission.

[0234] Optionally, when performing parallel transmission of multiple links, the switching execution module 105 also monitors the actual transmission quality of each link in the aggregated link set in real time. When the actual packet loss rate or latency of a certain link suddenly deteriorates and cannot be predicted in advance by the expected signal attenuation trend, the switching execution module 105 triggers an emergency adjustment mechanism: temporarily reducing the dynamic diversion weight of the link and quickly redistributing the data to be transmitted to other links with normal quality in order to cope with the sudden deterioration of link quality.

[0235] S704. When any link in the aggregated link set experiences link quality deterioration or is about to exceed its continuous coverage duration during the overlapping time period, the aggregated link set is updated based on the remaining candidate satellites in the availability prediction results. The dynamic traffic splitting weight is re-determined in the updated aggregated link set, and the dynamic addition or removal of the link is completed without interrupting service transmission.

[0236] Specifically, the switching execution module 105 continuously monitors the real-time link quality (including indicators such as signal-to-noise ratio, bit error rate, and signal strength) of each link in the aggregated link set during the overlapping time period, as well as the remaining continuous coverage duration of each link relative to the current time. When any link is detected to meet any of the following triggering conditions, an update operation of the aggregated link set is triggered: Triggering condition 1: Real-time link quality deterioration, i.e., the real-time link quality parameters of the link are lower than the preset quality threshold (e.g., signal-to-noise ratio is lower than 10dB, or bit error rate is higher than 10dB). The condition triggers a link when the signal strength is below a preset strength threshold, and this deterioration persists for more than a preset duration threshold (e.g., more than 3 seconds). This trigger condition is used to address sudden quality degradation of the link caused by weather changes, electromagnetic interference, or terminal movement.

[0237] Triggering condition two: The link is about to exceed its continuous coverage duration, meaning the difference between the current time of the link and the end time of the visible time window of the link in the availability prediction result is less than a preset margin time threshold (e.g., less than 30 seconds). This triggering condition is used to initiate the link replacement process in advance before the link loses its lock, avoiding data loss due to sudden link lockout.

[0238] When any of the above triggering conditions are met, the switching execution module 105 performs the following aggregated link set update operation: Ⅰ. The switching execution module 105 selects candidate satellites that meet the aggregation conditions from the remaining candidate satellites in the availability prediction results (i.e., other candidate satellites outside the current aggregated link set) as links to be added.

[0239] The above aggregation conditions include: (1) the overlap time of continuous coverage between the link to be added and other links in the current aggregated link set, excluding the link to be removed, is not less than the preset duration threshold; (2) after the link to be added is added, the total available bandwidth of the updated aggregated link set is not less than the service communication bandwidth requirement; (3) the current link quality parameter of the link to be added is not less than the preset quality threshold.

[0240] II. Switching execution module 105 determines the links to be dropped. When the trigger condition is link quality deterioration, the link with deteriorated quality is determined as the link to be dropped; when the trigger condition is that the continuous coverage duration is about to be exceeded, the link that is about to be exceeded is determined as the link to be dropped. If multiple links meet the trigger conditions at the same time, their respective links to be dropped are determined, and multiple update operations are performed sequentially.

[0241] III. The switching execution module 105 performs link updates in the order of first adding and then removing: first, the selected links to be added are added to the aggregated link set; after the links to be added are successfully established and the service context is synchronized, the links to be removed are then removed from the aggregated link set. The above "first adding and then removing" order ensures that there are always enough links in the aggregated link set to carry service transmission throughout the entire update process, thereby achieving uninterrupted service.

[0242] IV. After the link is successfully added, the switching execution module 105 re-executes steps S701 to S703 according to the updated aggregated link set, that is, redetermines the dynamic traffic splitting weight of each link in the aggregated link set at each time during the overlapping time period, and continues to execute the parallel transmission of business data according to the updated dynamic traffic splitting weight.

[0243] Once the link to be exited is exited, the switching execution module 105 releases the communication resources occupied by the link to be exited and removes the link from the aggregated link set.

[0244] In one possible implementation, when the switching time windows between the link to be joined and the link to be withdrawn overlap (i.e., the link to be joined has been successfully joined before the link to be withdrawn has withdrawn), the aggregated link set has a "transition state". In this transition state, the aggregated link set contains both the link to be joined and the link to be withdrawn, and all links cooperate to transmit service data.

[0245] When the switching execution module 105 reallocates dynamic traffic splitting weights during the transition period, it gradually reduces the dynamic traffic splitting weight of the link to be exited over time, while gradually increasing the dynamic traffic splitting weight of the link to be added over time, until the dynamic traffic splitting weight of the link to be exited drops to zero, at which point it exits the link. This "smooth transition" mechanism can further reduce the impact of link switching on service transmission, achieving truly seamless dynamic maintenance.

[0246] For example, suppose the aggregated link set currently contains links A, B, and C. At some point during the overlapping time period, it is detected that link A is about to exceed its continuous coverage duration (remaining coverage duration is less than 30 seconds). The handover execution module 105 filters links that meet the aggregation conditions from the remaining candidate satellites (links D and E). Assuming link D meets the aggregation conditions, link D is added to the aggregated link set. At this time, the aggregated link set is in a transitional state, containing links A, B, C, and D. The handover execution module 105 recalculates the dynamic traffic splitting weights, gradually reducing the weight of link A from 0.25 to 0, while gradually increasing the weight of link D from 0 to 0.25. The weights of links B and C remain unchanged. After the weight of link A drops to zero, link A is removed from the aggregated link set, the transitional state ends, and the aggregated link set is updated to links B, C, and D. The parallel transmission of service data is never interrupted throughout the entire process.

[0247] It should be noted that the structure of the above embodiments does not constitute a limitation on the system. Those skilled in the art will understand that the structure of the above embodiments is only related to some of the solutions in this application. The embodiments of this application can be extended or modified based on the structure of the above embodiments, and this application is not limited thereto.

[0248] The intelligent switching method for satellite communication command and control terminals provided in this application can make forward-looking link switching decisions based on the predicted motion trajectory of the command and control terminal and the availability prediction results of each candidate satellite under dynamically changing environments and service requirements, thereby ensuring the continuity of high-priority services and communication quality.

[0249] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0250] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0251] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from the spirit and scope of this invention, and this invention is also intended to include these modifications and variations.

Claims

1. A method for intelligent handover of a satellite communication command and control terminal, characterized in that, The method includes: The system acquires the situational information of the command and control terminal and the task parameters of the current command and control task; the situational information is used to indicate link quality, terminal pose and motion trend, environmental conditions and service requirements; and indicates the priority level, communication bandwidth requirements and communication duration requirements of the current command and control task. Based on the situation information and the mission parameters, at least one candidate satellite and the availability prediction result corresponding to the at least one candidate satellite are determined; the availability prediction result is used to indicate the visible time window, continuous coverage duration and expected signal attenuation degree of each candidate satellite within a future preset time window; Based on the situation information and the satellite availability prediction results, a comprehensive score for the communication link corresponding to the at least one candidate satellite is determined. Based on the comprehensive scoring results, a link switching decision is generated with the goal of achieving optimal service continuity and communication quality. Based on the link switching decision, the link switching is performed on the command terminal while maintaining the current service without interruption.

2. The method according to claim 1, characterized in that, The terminal pose and motion trend include: the location information, speed, and direction of motion of the command and control terminal; the environmental conditions include: terrain occlusion features; the determination of at least one candidate satellite and the availability prediction result corresponding to the at least one candidate satellite based on the situation information and the mission parameters includes: Based on the location information of the command and control terminal, the movement speed, the movement direction, and the communication duration requirement, the predicted movement trajectory of the command and control terminal within a future preset time window is determined; Based on the predicted motion trajectory and the ephemeris information of the initial satellite, the elevation and azimuth sequences of the at least one candidate satellite relative to the command and control terminal are determined. Based on the terrain shading features, at least one candidate satellite is determined from the initial satellites; Based on the ephemeris information of the at least one candidate satellite and the predicted motion trajectory, the start time, end time, continuous coverage duration, and path loss of the at least one candidate satellite relative to the command and control terminal within a future preset time window are determined. The availability prediction result is determined based on the start and end times of the visible time window, the duration of continuous coverage, and the path loss of the at least one candidate satellite relative to the command and control terminal within a future preset time window.

3. The method according to claim 1, characterized in that, The link quality includes: signal strength, signal-to-noise ratio, bit error rate, and link latency of the communication link corresponding to the at least one candidate satellite; the environmental conditions also include: electromagnetic interference intensity; the service requirements include: service type and service quality requirement level; the comprehensive score for determining the communication link corresponding to the at least one candidate satellite based on the situation information and the satellite availability prediction results includes: Based on the signal strength, signal-to-noise ratio, bit error rate, and link delay of the communication link corresponding to the at least one candidate satellite, determine the link quality score of the at least one candidate satellite; Based on the satellite availability prediction results, determine the link availability duration score of the at least one candidate satellite; Based on the electromagnetic interference intensity, determine the anti-interference capability score of the at least one candidate satellite; Based on the service type and service quality requirement level, determine the service compatibility score of the at least one candidate satellite; Based on the link quality score, link availability duration score, anti-interference capability score, and service adaptability score of the at least one candidate satellite, a comprehensive score for the communication link corresponding to the at least one candidate satellite is determined.

4. The method according to claim 3, characterized in that, The comprehensive score for the communication link corresponding to the at least one candidate satellite is determined based on the link quality score, link availability duration score, anti-interference capability score, and service adaptability score of the at least one candidate satellite, including: A multi-objective optimization function is constructed, taking the link quality score, link availability score, anti-interference capability score, and service adaptability score as input variables, with the optimization objectives being to minimize the link switching frequency and the service interruption probability. Based on the multi-objective optimization function and dynamic weighting coefficients, the comprehensive score of each candidate satellite is calculated; the dynamic weighting coefficients are dynamically determined according to the priority level of the current command and control mission indicated by the mission parameters and the service type indicated by the service requirements. The correspondence between the dynamic weighting coefficients and the mission parameters and the service requirements is as follows: When the service type is a command instruction service, the weight coefficient corresponding to the service adaptability score takes the maximum value; When the priority level indicated by the task parameters is higher than the preset level threshold, the weight coefficients corresponding to the link quality score and the link availability time score increase dynamically over time, and the increase is positively correlated with the cumulative motion distance in the predicted motion trajectory of the command and control terminal. When the electromagnetic interference intensity indicated by the environmental conditions is higher than a preset intensity threshold, the weighting coefficient corresponding to the anti-interference capability score increases.

5. The method according to claim 1, characterized in that, Based on the comprehensive scoring results, and with the goal of optimizing service continuity and communication quality, a link switching decision is generated, including: Obtain the comprehensive score of the communication link corresponding to each candidate satellite and sort them from high to low; Determine the comprehensive score ranking corresponding to the current primary link, and determine the target link based on the comprehensive score ranking; wherein, when the communication link corresponding to the candidate satellite ranked first is different from the current primary link, calculate the switching cost from the current primary link to the communication link corresponding to the candidate satellite ranked first; the switching cost includes at least switching delay, signaling overhead and frequency resource occupation; Based on the difference in comprehensive score between the comprehensive score of the communication link corresponding to the top-ranked candidate satellite and the comprehensive score of the current primary link, and in conjunction with the handover cost, the handover benefit is determined. When the switching benefit is greater than the preset switching threshold, the communication link corresponding to the candidate satellite ranked first is determined as the target link, and a switching decision to switch to the target link is generated.

6. The method according to claim 5, characterized in that, The switching cost also includes: Indication information on whether the satellite orbit types before and after the switch are the same; when the satellite orbit types before and after the switch are different, the switching cost is higher than the switching cost of switching to the same orbit type; The switching benefit is the normalized value of the overall score difference minus the switching cost; The preset switching threshold is higher than the threshold value for non-command instruction services when the service type is a command and control service.

7. The method according to claim 1, characterized in that, The method further includes: When the communication bandwidth requirement indicated by the service demand exceeds the bandwidth that the communication link corresponding to the candidate satellite with the highest comprehensive score can provide, at least two communication links are selected from the at least one candidate satellite as an aggregated link set based on the continuous coverage duration and expected signal attenuation of each candidate satellite indicated by the availability prediction result; wherein the overlap time period of the continuous coverage duration of each link in the aggregated link set within a future preset time window is not less than a preset duration threshold, and the total available bandwidth of each link is not less than the communication bandwidth requirement; Obtain the real-time bandwidth, latency, packet loss rate, and expected signal attenuation trend of each link in the aggregated link set during the overlapping time period; Based on the real-time bandwidth, latency, packet loss rate, and expected signal attenuation trend, the dynamic traffic splitting weight of each link at each moment within the overlapping time period is determined. The expected signal attenuation trend is used to indicate that when the expected signal attenuation of a link in the future exceeds a preset attenuation threshold, the dynamic splitting weight of that link in the corresponding future time is reduced. Based on the dynamic traffic splitting weights corresponding to each time moment, the service data is allocated to each link in the aggregated link set for parallel transmission; When any link in the aggregated link set experiences link quality deterioration or is about to exceed its continuous coverage duration during the overlapping time period, the aggregated link set is updated based on the remaining candidate satellites in the availability prediction results. The dynamic traffic splitting weight is re-determined in the updated aggregated link set, and the dynamic addition or removal of the link is completed without interrupting service transmission.

8. The method according to claim 1, characterized in that, The step of performing link switching based on the link switching decision, while ensuring that the current service of the command and control terminal remains uninterrupted, includes: Obtain the target link identifier indicated in the link switching decision, and initiate a link establishment request to the target satellite corresponding to the target link based on the target link identifier; The context information of the current service is synchronized between the target link and the current primary link. The context information includes at least the IP address mapping relationship of the current session, the transport layer connection status, the data packet sequence number and the application layer session status. Once the target link is established and the context information is synchronized, the service traffic will be switched from the current primary link to the target link. After the switchover is complete, the communication resources occupied by the currently primary link will be released.

9. A satellite communication command and control terminal intelligent switching system, characterized in that, The system includes: The situation awareness module is configured to acquire situation information of the command and control terminal and task parameters of the current command and control task; the situation information is used to indicate link quality, terminal pose and motion trend, environmental conditions and service requirements; and to indicate the priority level, communication bandwidth requirements and communication duration requirements of the current command and control task. The satellite availability prediction module is configured to determine at least one candidate satellite and the availability prediction result corresponding to the at least one candidate satellite based on the situation information and the mission parameters; the availability prediction result is used to indicate the visible time window, continuous coverage duration and expected signal attenuation degree of each candidate satellite in a future preset time window; The link comprehensive evaluation module is configured to determine the comprehensive score of the communication link corresponding to the at least one candidate satellite based on the situation information and the satellite availability prediction results. The switching decision module is configured to generate a link switching decision based on the comprehensive scoring results, with the goal of optimizing service continuity and communication quality; The switching execution module is configured to perform link switching based on the link switching decision, provided that the current service is not interrupted at the command and control terminal.

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