Satellite selection method, satellite selection system, device, and medium

Abstract

The application relates to the technical field of satellite communication, and discloses a satellite selection method, a satellite selection system, equipment and a medium. The method comprises the following steps: predicting the motion trajectory of a terminal device according to the position information and motion information of the terminal device at a current time; predicting the motion trajectory of a satellite according to the position information and motion information of the satellite at the current time; selecting a first candidate satellite set for the terminal device according to the motion trajectories of the terminal device and the satellite; and selecting a target satellite to be accessed by the terminal device from the first candidate satellite set. The application significantly improves the correctness of selecting a satellite for a terminal device.

Description

Technical Field

[0001] This application relates to the field of satellite communication technology, and in particular to a satellite selection method, satellite selection system, device and medium. Background Technology

[0002] With the increasingly dense deployment of low-Earth orbit satellite constellations, the global demand for satellite internet access is rising rapidly, especially in remote areas, complex environments, or high-speed mobile platforms where terrestrial cellular network coverage is limited, making satellite communication a crucial connectivity method. However, how terminal devices can quickly and accurately select the optimal access target from multiple simultaneously visible satellites remains a key technical challenge.

[0003] Current mainstream satellite selection methods are mostly based on fixed-weight scoring mechanisms, relying on simple ranking based on single or a few parameters such as elevation angle and signal strength. They lack the ability to perceive and predict the future motion of terminal devices, easily leading to frequent link interruptions and affecting communication continuity in high-speed dynamic scenarios. Some methods have introduced machine learning-based scoring models, but these suffer from high computational complexity, large training data requirements, and difficulties in deploying on embedded terminal devices, making them difficult to implement in resource-constrained scenarios. Summary of the Invention

[0004] In view of this, this application provides a satellite selection method, satellite selection system, device and medium, which significantly improves the accuracy of satellite selection for terminal devices and is applicable to high-speed mobile terminal devices to achieve intelligent and forward-looking access control in environments with multiple visible satellites.

[0005] This application discloses a satellite selection method, which includes: Based on the current location and motion information of the terminal device, predict the motion trajectory of the terminal device; the motion information includes velocity and / or acceleration. Based on the satellite's current position and motion information, predict the satellite's trajectory. Based on the motion trajectories of the terminal device and the satellite, a first candidate satellite set is selected for the terminal device; the first candidate satellite set consists of candidate satellites; the candidate satellites are satellites to be selected by the terminal device. Select a target satellite for the terminal device to access from the first set of candidate satellites.

[0006] Further, the step of selecting a first candidate satellite set for the terminal device based on the motion trajectory of the terminal device and the satellite includes: Based on preset conditions, a first candidate satellite set is obtained by filtering from the original satellite set; the original satellite set consists of satellites currently visible to the terminal device.

[0007] Furthermore, the preset conditions include a first condition, a second condition, a third condition, and a fourth condition; The first condition is related to the first included angle and the preset elevation angle threshold; the first included angle is the angle between the line-of-sight vector and one of the coordinate axes in the coordinate system; The second condition is related to the second included angle and a preset included angle threshold; the second included angle is the angle between the antenna pointing of the terminal device and the line-of-sight vector; The third condition is related to the third included angle and the half-power beamwidth; the third included angle is the angle between the axial unit vector of the satellite's beam at the terminal device and the line-of-sight vector; The fourth condition is related to the satellite's continuous availability time and a preset time threshold; the satellite's continuous availability time is the time during which the first condition, the second condition, and the third condition are simultaneously met and maintained.

[0008] Further, the step of selecting a target satellite for the terminal device to access from the first candidate satellite set includes: Based on the service type and attribute vector currently being executed by the terminal device, an initial weight vector and an initial attribute vector are determined; the attribute vector consists of multiple attributes; the multiple attributes include the satellite's continuous availability time, average elevation angle, the trend of changes in the satellite signal strength received by the terminal device, satellite capacity, and the risk of the terminal device losing connection with the satellite; Based on the initial weight vector and the initial attribute vector, the matching degree corresponding to each candidate satellite in the first candidate satellite set is determined; the matching degree is the matching degree between the initial attribute vector and the service type currently being executed by the terminal device. Based on the matching degree of each candidate satellite in the first candidate satellite set, a target satellite to be accessed is selected for the terminal device.

[0009] Further, determining the initial weight vector and initial attribute vector based on the service type and attribute vector currently being executed by the terminal device includes: Select the corresponding initial weight vector based on the type of service currently being performed by the terminal device; Select attributes from the attribute vector that correspond to the service type currently being executed by the terminal device to form an initial attribute vector.

[0010] Further, determining the matching degree corresponding to each candidate satellite in the first candidate satellite set based on the initial weight vector and the initial attribute vector includes: The initial weight vector and the preprocessed initial attribute vector are multiplied together, and the results of the multiplication are accumulated to obtain the matching degree corresponding to each candidate satellite in the first candidate satellite set; the preprocessed initial attribute vector is obtained by preprocessing the initial attribute vector.

[0011] Further, the step of selecting a target satellite for the terminal device to access based on the matching degree corresponding to each candidate satellite in the first candidate satellite set includes: If a satellite to be accessed is selected for the terminal device for the first time, the candidate satellite with the highest matching degree is selected from the first candidate satellite set as the target satellite.

[0012] Further, the step of selecting a target satellite for the terminal device to access based on the matching degree corresponding to each candidate satellite in the first candidate satellite set includes: If the terminal device is already connected to the target satellite and initiates a request to switch satellites, then a new target satellite to be connected is selected for the terminal device based on the updated initial weight vector, the switching success rate, and the first candidate satellite set; the updated initial weight vector is determined based on the initial weight vector.

[0013] Furthermore, the method for obtaining the updated initial weight vector includes: The loss is determined based on key performance indicators, including the handover failure rate, the duration of disconnection between the terminal device and the satellite, and the average effective throughput of the terminal device. Based on the loss, each weight in the initial weight vector is adjusted to obtain the adjusted initial weight vector; Normalize each weight in the adjusted initial weight vector to obtain a normalized initial weight vector; The updated initial weight vector is obtained based on the initial weight vector, the normalized initial weight vector, and the smoothing coefficient.

[0014] Further, adjusting each weight in the initial weight vector according to the loss to obtain the adjusted initial weight vector includes: Based on the loss and each weight in the initial weight vector, determine the approximate gradient of the loss corresponding to each weight in the initial weight vector; The updated initial weight vector is obtained by using each weight in the initial weight vector and its corresponding loss approximation gradient.

[0015] Further, the step of reselecting a target satellite for the terminal device to access based on the updated initial weight vector, the handover success rate, and the first candidate satellite set includes: If the success rate of switching of candidate satellites in the first candidate satellite set is less than a preset switching threshold, then the candidate satellites are removed from the first candidate satellite set to obtain a second candidate satellite set. Based on the time during which the matching degree of the candidate satellites in the second candidate satellite set is continuously greater than a first preset value, and a preset duration, a target satellite to be accessed is selected for the terminal device from the second candidate satellite set; the first preset value is related to the matching degree of the target satellites currently accessed by the terminal device.

[0016] Furthermore, the method for obtaining the matching degree corresponding to the candidate satellites in the second candidate satellite set includes: The updated initial weight vector and the preprocessed initial attribute vector are multiplied together, and the results of the multiplication are accumulated to obtain the matching degree corresponding to the candidate satellites in the second candidate satellite set; the preprocessed initial attribute vector is the result of preprocessing the initial attribute vector.

[0017] Furthermore, the method for obtaining the service type currently being executed by the terminal device includes: When the terminal device initiates a satellite access request, the access request information sent by the terminal device is identified to obtain the service type label, service quality parameters, or protocol signaling fields carried in the communication protocol corresponding to the terminal device. The type of service currently being executed by the terminal device is obtained based on the service type tag, quality of service parameters, or protocol signaling fields corresponding to the terminal device.

[0018] This application also discloses a satellite selection system, which includes: A terminal device trajectory prediction module is used to predict the motion trajectory of the terminal device based on the terminal device's current position information and motion information; the motion information includes velocity and / or acceleration. The satellite trajectory prediction module is used to predict the trajectory of the satellite based on its current position and motion information. The candidate satellite selection module is used to select a first set of candidate satellites for the terminal device based on the motion trajectory of the terminal device and the satellite; the first set of candidate satellites consists of candidate satellites; the candidate satellites are the satellites to be selected by the terminal device. The target satellite determination module is used to select a target satellite for the terminal device to access from the first candidate satellite set.

[0019] This application also discloses an electronic device including a processor and a memory, wherein the memory is used to store a computer program and the processor is used to execute the computer program to implement the method described above.

[0020] This application also discloses a computer-readable storage medium comprising a computer program or instructions that, when executed on a computer, cause the computer to perform the methods described above.

[0021] By adopting the above technical solution, this application has the following advantages: it allows terminal devices to dynamically select attributes and automatically adjust their weight combinations according to specific business types, thereby achieving task awareness and strategy adaptability, and significantly improving the business matching degree and scheduling intelligence of star selection decision. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0023] Figure 1 This is a flowchart illustrating a satellite selection method according to an embodiment of this application; Figure 2 This is a schematic diagram showing the location of the terminal device and the satellite coverage area in an embodiment of this application; Figure 3 This is a schematic diagram illustrating the predicted terminal device trajectory and satellite coverage area according to an embodiment of this application. Figure 4 This is a schematic diagram of the matching degree results of satellites based on service attributes in an embodiment of this application; Figure 5 This is a block diagram of an electronic device according to an embodiment of this application. Detailed Implementation

[0024] The present application will be further described in conjunction with the accompanying drawings and embodiments. The described embodiments are only some, not all, of the embodiments of the present application. All other embodiments obtained by those skilled in the art should fall within the protection scope of the embodiments of the present application.

[0025] See Figure 1 This application provides an embodiment of a satellite selection method, including: Step 1: Based on the location and motion information of the terminal device at the current moment, predict the motion trajectory of the terminal device.

[0026] Motion information includes velocity and / or acceleration.

[0027] In one embodiment of this application, the motion trajectory of the terminal device is predicted based on its current location and motion information; the motion information includes speed and / or acceleration; and the motion trajectory of the satellite is predicted based on its current location and motion information. The terminal device can be a high-speed mobile terminal device, such as a drone, train, or shipborne system.

[0028] In one possible implementation of this application, let the current time be t, and define the next time window. ;in, (Prediction window duration, in seconds; typical reference value 60–180 s). Discrete sampling step size. (Sampling step size, unit s, typical reference value 0.5–1.0 s), discrete time is . This represents the total number of discrete moments within the next time window.

[0029] Without sacrificing generality, a constant velocity (CV) / constant acceleration (CA) discrete state model is adopted. When IMU / GNSS fusion is available, Kalman filter (KF), unscented Kalman filter (UKF), or interacting multiple model (IMM) can be used to recursively estimate the state and covariance. The terminal device at time... Location ,speed acceleration Attitude / Antenna pointing unit vector .

[0030] Constant velocity (CV) model (independent for each axis)

[0031] Constant acceleration (CA) model

[0032] in, and This is the process noise intensity multiplier; in high-speed / turning conditions, it can be switched to the IMM model.

[0033] Step 2: Based on the satellite's current position and motion information, predict the satellite's trajectory.

[0034] Based on the above possible implementation methods, for the i-th satellite Using two-line roots (TLE) as orbital input, and applying the simplified generalized orbital model (Simplified General Perturbations 4, SGP4; Deep Space Perturbation Version SDP4) in the next time window... discrete time By extrapolating, the inertial frame position of each satellite is obtained. .

[0035] Will Transforming to the Earth-Centered, Earth-Fixed (ECEF) system, we get Establish a local East-North-Up (ENU) coordinate system with the location of the terminal device as the origin, and rotate the relative vector to the ENU:

[0036]

[0037] in, To point from the terminal device to the satellite at a specific time The three-dimensional positional difference, i.e., the line-of-sight vector. for The unit vector.

[0038] This application predicts the future trajectory of terminal devices and simultaneously calculates the trajectories of multiple candidate satellites. By modeling the relative motion of the future spatiotemporal relationship between the two, it can more accurately calculate key forward-looking indicators such as the continuous availability time, elevation angle, and whether there is a risk of obstruction within the future window. It can accurately judge the future sustainability of the link and effectively eliminate satellites that are about to fail, thereby significantly reducing the link switching frequency and interruption rate in high-speed mobile scenarios. Its stability is far superior to unidirectional prediction methods.

[0039] This application employs a two-way trajectory extrapolation mechanism: the terminal device collects its own dynamic parameters (position, velocity, heading, acceleration, etc.) in real time through a state awareness module, and combines this with satellite ephemeris data to participate in link (the link between the satellite and the terminal device) prediction, achieving accurate prediction of link sustainability within a future time window. This mechanism can preemptively exclude satellites that are "about to fail," increase link uptime, reduce the probability of false selection, and significantly enhance communication stability in high-speed dynamic environments.

[0040] Step 3: Select the first candidate satellite set for the terminal device based on the motion trajectory of the terminal device and the satellite.

[0041] The first candidate satellite set consists of candidate satellites; the candidate satellites are the satellites that the terminal equipment will select.

[0042] In one embodiment of this application, selecting a first candidate satellite set for the terminal device based on the motion trajectory of the terminal device and the satellite includes: Based on preset conditions, a first candidate satellite set is obtained by filtering from the original satellite set; the original satellite set consists of satellites currently visible to the terminal device.

[0043] In one embodiment of this application, the preset conditions include a first condition, a second condition, a third condition, and a fourth condition. The first condition is related to a first included angle and a preset elevation angle threshold. The first included angle is the angle between the line-of-sight vector and a coordinate axis in the coordinate system. The line-of-sight vector is the position difference between the terminal device and the satellite it points to. The origin of the coordinate system is the position of the terminal device. The second condition is related to a second included angle and a preset included angle threshold. The second included angle is the angle between the antenna pointing of the terminal device and the line-of-sight vector. The third condition is related to a third included angle and half-power beamwidth. The third included angle is the angle between the axial unit vector of the satellite beam at the terminal device and the line-of-sight vector. The fourth condition is related to the satellite's continuous availability time and a preset time threshold. The continuous availability time of the satellite is the time during which the first, second, and third conditions are simultaneously satisfied. The line connecting the midpoint of the projection of the satellite beam onto the plane where the terminal device is located and the satellite is the axial vector of the satellite's downlink beam at the terminal device, and the unit vector of this axial vector is the axial unit vector.

[0044] Based on the above-mentioned feasible methods, for satellites Each have: (1) Elevation: The angle between the line-of-sight vector and one of the coordinate axes in the coordinate system;

[0045] in, Angle of elevation The U-axis of ENU (local vertical / zenith direction) is in degrees (°).

[0046] (2) Antenna-line of sight angle: The angle between the antenna pointing and the line of sight vector;

[0047] in, The angle between the antenna and the line of sight. The unit vector (ENU) is the direction of the antenna beam center of the terminal device.

[0048] (3) Bundle determination (Boolean) set up Let be the axial unit vector (boresight, ENU) of the downlink beam of the i-th satellite at the terminal device. Half-Power Beam Width (HPBW, -3dB, unit: °). Definition:

[0049] Let "in bundle" be uniformly denoted as a Boolean value: This indicates that the terminal device is located within the downlink beam of the i-th satellite. This indicates that the terminal device is not located within the downlink beam of the i-th satellite.

[0050] (4) Single-moment availability criterion , in, The minimum elevation angle threshold (°) The maximum included angle threshold (°).

[0051] (5) Satellite availability duration The above criteria ((4) all criteria in the single-moment availability criterion) are in Total duration of consecutive establishment within the period ; Original satellite collection: (Currently visible low-orbit satellites).

[0052] Screening criteria (if any one of them is met, the item will be removed): (1)

[0053] (2)

[0054] (3)

[0055] The coverage may fail due to the relative motion causing the beam to leave the beam.

[0056] Output: First candidate satellite set .

[0057] Step 4: Select the target satellite for the terminal device to access from the first set of candidate satellites.

[0058] In one embodiment of this application, an initial weight vector and an initial attribute vector are determined based on the service type and attribute vector currently being executed by the terminal device. The attribute vector consists of multiple attributes, including the satellite's continuous availability time, average elevation angle, the trend of changes in the satellite signal strength received by the terminal device, satellite capacity, and the risk of the terminal device losing connection with the satellite. Based on the initial weight vector and the initial attribute vector, the matching degree corresponding to each candidate satellite in the first candidate satellite set is determined. The matching degree is the matching degree between the initial attribute vector and the service type currently being executed by the terminal device. Based on the matching degree corresponding to each candidate satellite in the first candidate satellite set, a target satellite to be accessed is selected for the terminal device.

[0059] This application implements the matching degree function of "selecting parameters as needed and adjusting weights according to scenarios", which makes the star selection decision highly matched with the actual business objectives, improves the adaptability of the star selection decision to the actual business type, greatly improves the efficiency of network resource utilization, and reduces unnecessary access switching.

[0060] In one embodiment of this application, determining an initial weight vector and an initial attribute vector based on the service type and attribute vector currently being executed by the terminal device includes: Based on the service type currently being executed by the terminal device, a corresponding initial weight vector is selected; attributes corresponding to the service type currently being executed by the terminal device are selected from the attribute vector to form an initial attribute vector. For example, the template weights (initial weight vectors) corresponding to the service type currently being executed by the terminal device are called from a preset weight template library.

[0061] In one embodiment of this application, determining the matching degree corresponding to each candidate satellite in the first candidate satellite set based on the initial weight vector and the initial attribute vector includes: The initial weight vector and the preprocessed initial attribute vector are multiplied together, and the results are summed to obtain the matching degree for each candidate satellite in the first candidate satellite set. The preprocessed initial attribute vector is obtained by preprocessing the initial attribute vector. The preprocessing includes Windsorization and normalization.

[0062] In one embodiment of this application, selecting a target satellite for the terminal device to access based on the matching degree corresponding to each candidate satellite in the first candidate satellite set includes: If a satellite to be accessed is selected for the terminal device for the first time, the candidate satellite with the highest matching degree is selected from the first candidate satellite set as the target satellite.

[0063] In one embodiment of this application, selecting a target satellite for the terminal device to access based on the matching degree corresponding to each candidate satellite in the first candidate satellite set includes: If the terminal device is already connected to the target satellite and initiates a satellite handover request, then a new target satellite is selected for the terminal device to connect to based on the updated initial weight vector, handover success rate, and the first candidate satellite set; the updated initial weight vector is determined based on the initial weight vector. The handover success rate is the ratio of the number of successful satellite handovers by the terminal device to the total number of handover requests initiated for the satellite.

[0064] In one embodiment of this application, the method for obtaining the updated initial weight vector includes: Based on key performance indicators (KPIs), the loss is determined. These KPIs include the handover failure rate, the duration of disconnection between the terminal device and the satellite, and the average effective throughput of the terminal device. The handover failure rate is the ratio of the number of failed handover attempts to the satellite to the total number of handover requests initiated by the terminal device. Based on the loss, each weight in the initial weight vector is adjusted to obtain the adjusted initial weight vector. Each weight in the adjusted initial weight vector is then normalized to obtain the normalized initial weight vector. Finally, based on the initial weight vector, the normalized initial weight vector, and the smoothing coefficient, the updated initial weight vector is obtained.

[0065] In one embodiment of this application, each weight in the initial weight vector is adjusted according to the loss to obtain an adjusted initial weight vector, including: Based on the loss and each weight in the initial weight vector, determine the approximate gradient of the loss corresponding to each weight in the initial weight vector; based on each weight in the initial weight vector and its corresponding approximate gradient of the loss, obtain the updated initial weight vector.

[0066] In one embodiment of this application, the process of reselecting a target satellite for the terminal device to access based on the updated initial weight vector, handover success rate, and first candidate satellite set includes: If the success rate of switching of candidate satellites in the first candidate satellite set is less than the preset switching threshold, then the candidate satellites are removed from the first candidate satellite set to obtain the second candidate satellite set; based on the time when the matching degree corresponding to the candidate satellites in the second candidate satellite set is continuously greater than the first preset value, and the preset duration, a target satellite to be accessed is selected for the terminal device from the second candidate satellite set; the first preset value is related to the matching degree corresponding to the target satellite currently accessed by the terminal device.

[0067] For example, if the matching degree of the candidate satellites in the second candidate satellite set is greater than the first preset value for a period of time that is greater than or equal to the preset duration, then a target satellite to be accessed is selected from the second candidate satellite set for the terminal device.

[0068] In one embodiment of this application, the method for obtaining the matching degree corresponding to the candidate satellites in the second candidate satellite set includes: The updated initial weight vector and the preprocessed initial attribute vector are multiplied together, and the results of the multiplication are accumulated to obtain the matching degree of the candidate satellites in the second candidate satellite set; the preprocessed initial attribute vector is the result of preprocessing the initial attribute vector.

[0069] In one embodiment of this application, the method for obtaining the service type currently being performed by the terminal device includes: When a terminal device initiates a satellite access request, the access request information sent by the terminal device is identified to obtain the corresponding service type label, quality of service parameters, or protocol signaling fields carried in the communication protocol. The service type label indicates the type of service performed by the terminal device. The quality of service parameters include the maximum allowable latency and the target bandwidth. The target bandwidth supports the data transmission rate from the terminal device to the satellite required for the current service type. Based on the corresponding service type label, quality of service parameters, or protocol signaling fields, the type of service currently performed by the terminal device is obtained.

[0070] This application constructs a complete closed-loop process from terminal device status perception, trajectory prediction, candidate screening, multi-dimensional matching to link access and dynamic updates, which is adapted to real-world communication scenarios with high dynamism, limited resources, and multiple concurrent tasks. The process has engineering characteristics such as modularity, low power consumption, and separation of software and hardware.

[0071] Based on the above-mentioned feasible methods, in the next time window Within, for the i-th candidate satellite Construct attribute vectors: ,in, K represents the number of available attributes and K is the number of attributes used.

[0072] Common attributes and semantics: : The duration of satellite availability, measured in seconds; Average elevation angle, in degrees; The changing trend of satellite signal strength received by the terminal device ( ); Satellite capacity (obtained by mapping from modulation and coding schemes or link budget), unit: Mbps; : Risk of terminal equipment losing connection with satellite (0 indicates no risk, 1 indicates high risk).

[0073] Select attributes from the attribute vector that correspond to the type of service currently being performed by the terminal device to form the initial attribute vector.

[0074] Processing order: Initial attribute vector → Windsorization (removing extreme values ​​by 5% / 95% quantile) → Standardization (Min–Max or Z-score, trend term can be cut off to [-1,1]) → Standardized attributes (preprocessed initial attribute vector) (Standardized value; [0,1]).

[0075] The matching degree for each satellite is obtained using the matching degree function shown in the following formula:

[0076] in, Let be the matching degree corresponding to the i-th satellite. Let K be the weight of the k-th attribute, where K represents the number of attributes used.

[0077] Based on the above possible implementation methods, when a terminal device initiates a satellite access request, it is identified according to the service context information it reports. The content obtained includes: service type labels issued by the core network or upper-layer applications (such as low-latency interaction, high-bandwidth transmission, emergency video backhaul, low-power monitoring); associated quality of service parameters (QoS), such as maximum allowable latency, target bandwidth, packet loss rate threshold; and protocol signaling fields carried in existing communication protocols (such as QFI (QoSFlowIdentifier, network slice ID, dedicated APN / DSCP, etc., often bound to specific service scenarios).

[0078] If there is a service type label, the service type Type is directly established; if there is no service type label but there is a signaling mapping (such as a QFI / slice clearly corresponding to "emergency video"), the service type Type is established accordingly; if there is neither a service type label nor a signaling mapping, the service type Type is inferred from the QoS threshold / model (such as a very strict latency threshold and medium bandwidth, then the service type is low latency interaction).

[0079] Based on the identified service type, the system determines the service type currently being carried by the terminal device. After service identification, the system retrieves the template weight corresponding to the service type from the preset weight template library. As shown in Table 1: Table 1. Correspondence between business types and initial weight vectors

[0080] During the initial satellite access phase of the terminal device, the matching degree corresponding to each satellite is obtained based on the initial weight vector of the service template. After the connection is established, the weights in the initial weight vector are adaptively adjusted online according to the service type / operating environment. On this basis, optimization and handover determination are completed in conjunction with the handover success rate, as detailed in steps S1 to S4. The operating environment refers to the actual performance of the external state (geometric visibility, channel / interference, satellite and backhaul load, weather obstruction, terminal device movement, etc.) within the current time window. The external state is reflected by the measured key performance indicators (KPIs).

[0081] S1: Initial Connection The system loads an initial weight vector based on the service type (such as low-latency interaction, broadband backhaul, emergency video, and low-power sensing). And directly based on the above Select the satellite with the highest matching degree and establish the initial link between the satellite and the terminal equipment.

[0082] S2: Online Weight Adaptation After establishing the initial connection, the system needs to perform routine satellite handover within subsequent time windows, or identify a better access target based on service type. To this end, a set of Key Performance Indicators (KPIs) needs to be collected, including the number of handover requests, the number of handover failures, the P95 downtime, and average throughput, and organized into structured data divided by time windows. Subsequently, the weight vector is updated in small steps based on these indicators, allowing the preference direction of the matching function to be dynamically adjusted according to business objectives, thereby ensuring that the matching results are consistent with actual service requirements.

[0083] Set a window-level KPI: failure rate of handover requests initiated by terminal devices. Duration of disconnection between terminal equipment and satellite (Refers to the 95th percentile of the total duration of all consecutive "unavailable" segments within the same time window as the outage duration index for that time window (recorded as 0 if there are no outage events)), and the average effective throughput on the terminal device side. Define loss:

[0084] in, KPI weights.

[0085] set up The weight vector (dimensionless) actually used for matching in the t-th time window. ).make This is the approximate gradient of the loss in the k-th dimension. The update consists of three steps: (1) Multiplicative update + box constraint pruning

[0086] (2) Normalization (to obtain candidate weights)

[0087]

[0088] (3) Exponential smoothing (to obtain the weights actually used in the next time window)

[0089] Current time window matching ; Calculate the KPI corresponding to the current time window based on the KPI corresponding to the historical time window. After the weight update is performed, the weights for the next time window are changed to... .

[0090] in, The learning rate (dimensionless, recommended 0.02-0.08); For interval clipping operators; and All are weighted box constraints ( The value can be 0.05. The value can be 0.5). Candidate weights; The smoothing coefficient (dimensionless, with a value range of 1000). ), used to suppress weight jitter; The loss is a window-level loss, composed of KPIs such as switching failure rate, downtime P95, and average throughput.

[0091] Within M consecutive time windows continuous deterioration or If the threshold is exceeded, revert to the most recently stable weight configuration. .

[0092] S3: Candidate Generation and Historical Information Filtering During the routine satellite handover phase (not the first access), the following screening sequence is executed: Define the handover success rate (SuccessRate(SR)): within the current time window, the success rate of the i-th satellite... The success rate of the switchover is ,like If the value is less than the set threshold, satellites will no longer be considered within the current time window. .

[0093] S4: Switching between triggering and execution To avoid jitter-induced switching, satellites are switched only if the matching advantage remains valid for the duration of the trigger hold period:

[0094] in: This refers to the hysteresis ratio, with a typical reference value of 8%–15%. The trigger hold duration is measured in seconds (s), with a typical reference value of 0.8–2.0. This represents the matching degree of the satellites that the terminal devices have connected to within the current time window. This represents the matching degree of the satellite to be switched to for the terminal device within the current time window.

[0095] This application constructs a business-driven multi-attribute adaptive matching mechanism, which introduces a scene recognition and strategy configuration module during the satellite selection process. This allows terminal devices to select the corresponding link evaluation indicators based on the type of service they carry (such as video communication, data sensing, broadband backhaul, etc.) and dynamically adjust the weight combination. This mechanism can effectively match task requirements and achieve more efficient utilization of communication resources and more stable link connection quality.

[0096] In the above embodiments, in addition to using elevation angle, signal strength, and time, other available satellite link or system parameters can be introduced into the matching degree function, such as satellite load factor (priority decreases when load is high), system backhaul bandwidth or network congestion information, inter-satellite link delay estimate and energy consumption budget (applicable to energy-constrained terminal equipment), to ensure improved robustness of access satellites under multi-index fusion and further optimize satellite selection accuracy.

[0097] In the above embodiments, the weights in the matching degree function can be configured by the service type, or dynamically set in the following ways: adaptively adjusted according to the environmental state based on machine learning models (such as linear regression, decision trees); learn to generate the optimal weights from historical communication data (policy migration); and remotely issue weight configuration templates to the access control center to achieve policy adaptation capabilities for different network conditions and service scenarios.

[0098] In the above embodiments, the matching degree function can be extended from a weighted linear function to: 1) piecewise linear: setting thresholds for key attributes and changing the slope / applying penalties to improve boundary sensitivity nonlinear fusion; 2) using differentiable nonlinearity to enhance / suppress the contribution of certain indicators, improving the response to extreme values ​​or inflection points; 3) fuzzy logic or rule engine form (facilitating the expression of empirical strategies). This adapts to the decision sensitivity requirements of different scenarios and enhances the anti-interference capability in edge scenarios.

[0099] In the above embodiments, the terminal device trajectory prediction can adopt different methods to balance prediction accuracy and complexity: linear extrapolation (suitable for resource-constrained scenarios); sliding window average prediction (low accuracy and fast); Transformer / GRU model (complex but suitable for long-term prediction), so as to ensure that the predicted trajectory is used for the evaluation of future time windows and improve the effectiveness of forward-looking access judgment.

[0100] This application can be deployed in the following different types of terminal equipment: high-speed flight platforms (such as drones and aircraft); ground vehicle-mounted or railway communication terminal equipment; shipborne systems (such as ships); and static base stations for dynamic satellite handover optimization. This application can adapt to various dynamic environments and high-frequency access handover requirements, maintaining communication stability.

[0101] Figure 2 and Figure 3 This demonstrates that by predicting the movement trend of terminal devices, it is possible to determine whether they will remain within the effective beam of a satellite in the future, thereby effectively assessing the sustainability of the link. This avoids the frequent interruptions of communication links caused by traditional methods that only select satellites based on the current elevation angle. It is the key data foundation for calculating the "service duration" index and "satellite selection" in this application. Figure 4 The results show the ranking comparison of different candidate satellites (first to fifth candidate satellites) under the multi-attribute matching system in two actual business scenarios, reflecting the selection logic of satellite access targets after the terminal equipment dynamically adjusts attributes and weights according to the type of service it carries. Figure 4 The data in the system is generated by the terminal device's strategy module, which generates attributes and weights. After normalization and weighting, the matching degree corresponding to each satellite is output.

[0102] This application describes how the above embodiments are applied to two typical scenarios: emergency video communication and long-distance bandwidth transmission, to obtain matching results and their impact on terminal device behavior. Specifically: Scenario 1: Emergency Video Communication An example application is a real-time video transmission system for disaster relief drones; communication requirements include strong real-time performance (video must be kept uninterrupted), high link continuity (frequent satellite switching should be avoided to prevent connection recovery delays), and anti-interference capability (link attenuation caused by path obstruction should be avoided as much as possible).

[0103] Attribute selection and rationale: 1) Duration of availability: reflects the link continuity within the future time window; 2) Average elevation angle: a high elevation angle usually means less channel loss and more stable communication; 3) Obstruction / failure risk: used to eliminate satellite paths that will be obstructed in advance.

[0104] Matching results: The second candidate satellite has the highest matching degree. Its trajectory will always cover the terminal device in the next time window, and its elevation angle is stable. The link is expected to be maintained for about 90 seconds, which is suitable for this scenario. Although the third candidate satellite has a strong signal, its available time is short and it is not the first choice.

[0105] Impact of terminal device behavior: 1) The access control module selects the second candidate satellite based on the matching degree and delays the triggering of the switch; 2) Even if other satellites have strong signals at an instant, they will not be accessed if their availability is insufficient in the future, thus ensuring video continuity.

[0106] Scenario 2: Long-distance bandwidth transmission Application example: Shipborne terminal equipment performs multi-source data synchronous reporting; communication requirements include high transmission throughput (suitable for batch data uplink in missions), stable link quality but not sensitive to microsecond-level latency, and support for short-term high-bandwidth burst missions.

[0107] Attribute selection and rationale: 1) Signal strength trend: reflects whether it is in the signal strength enhancement stage; 2) Estimated link capacity: when the terminal device selects a satellite for the first time, the link capacity is estimated in combination with the beam bandwidth and frequency band; when the terminal device disconnects the satellite, the link capacity is estimated in combination with the beam bandwidth, frequency band, on-board load, etc.

[0108] Matching results: The fourth candidate satellite has a significantly higher matching degree and a clear signal enhancement trend, with an estimated remaining bandwidth of 15Mbps; the first candidate satellite has a long coverage time, but low capacity and high path loss, so it is not the preferred choice.

[0109] Impact of terminal device behavior: 1) The scheduling system tends to use the fourth candidate satellite to complete the transmission of a large amount of data at once; 2) The switching control module adjusts the weights to adapt to the demand and prepares for the next preferred satellite.

[0110] In emergency video communication scenarios, estimated availability time is given extremely high weight to ensure link continuity. In long-distance ocean bandwidth transmission scenarios, signal strength trends and satellite capacity are prioritized to improve data throughput.

[0111] This application also provides a satellite selection system, which includes: The terminal device trajectory prediction module is used to predict the trajectory of the terminal device based on its current location and motion information; the motion information includes velocity and / or acceleration. The satellite trajectory prediction module is used to predict the satellite's trajectory based on the satellite's current position and motion information. The candidate satellite selection module is used to select a first set of candidate satellites for the terminal device based on the motion trajectory of the terminal device and the satellites; the first set of candidate satellites consists of candidate satellites; the candidate satellites are the satellites to be selected by the terminal device. The target satellite determination module is used to select a target satellite for the terminal device to access from the first set of candidate satellites.

[0112] This application also provides an electronic device including a processor, a bus, a memory, and a communication interface. The processor, memory, and communication interface are connected via the bus. The processor can be a CPU (Central Processing Unit), or other general-purpose processors, DSPs (Digital Signal Processors), ASICs (Application Integrated Circuits), FPGAs (Field-Programmable Gate Arrays), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc. The communication interface is used to enable communication between the electronic device and external devices or components. The communication interface is used for data interaction with other computing devices. The bus can include a path for transmitting information between the aforementioned components (such as the processor and memory). In addition to a data bus, the bus can also include a power bus, a control bus, and a status signal bus, etc. As an example, the electronic device can include multiple processors. A processor can refer to one or more devices, circuits, and / or computing units for processing data (such as computer programs). The processor can call the computer program stored in the memory to implement the satellite selection method described in the above embodiments. Figure 5 Taking an electronic device consisting of one processor and one memory as an example, the processor and memory are used to indicate a type of device or equipment, and the quantity of each type of device or equipment can be determined according to business needs.

[0113] This application also provides a computer-readable storage medium including a computer program or instructions that, when executed on a computer, cause the computer to perform the methods described in the above embodiments.

[0114] It should be noted that, in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0115] Those skilled in the art should clearly understand that, for the sake of convenience and brevity, the specific working processes of the satellite selection method, satellite selection system, electronic equipment, and computer-readable storage medium described in the above embodiments can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0116] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware, or by a program instructing the relevant hardware to implement them. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0117] The above are merely optional embodiments of this application, used only to illustrate the technical solution of this application and not to limit it. Any modifications, equivalent substitutions, improvements, etc., to the specific implementation of this application without departing from the spirit and scope of this application should be covered within the protection scope of this application.

Claims

1. A satellite selection method, characterized in that, include: Based on the current location and motion information of the terminal device, predict the motion trajectory of the terminal device; the motion information includes velocity and / or acceleration. Based on the satellite's current position and motion information, predict the satellite's trajectory. Based on the motion trajectories of the terminal device and the satellite, a first candidate satellite set is selected for the terminal device; the first candidate satellite set consists of candidate satellites; the candidate satellites are satellites to be selected by the terminal device. Select a target satellite for the terminal device to access from the first set of candidate satellites.

2. The method according to claim 1, characterized in that, The step of selecting a first candidate satellite set for the terminal device based on the motion trajectory of the terminal device and the satellite includes: Based on preset conditions, a first candidate satellite set is obtained by filtering from the original satellite set; the original satellite set consists of satellites currently visible to the terminal device.

3. The method according to claim 2, characterized in that, The preset conditions include a first condition, a second condition, a third condition, and a fourth condition; The first condition is related to the first included angle and the preset elevation angle threshold; the first included angle is the angle between the line-of-sight vector and one of the coordinate axes in the coordinate system; The second condition is related to the second included angle and a preset included angle threshold; the second included angle is the angle between the antenna pointing of the terminal device and the line-of-sight vector; The third condition is related to the third included angle and the half-power beamwidth; the third included angle is the angle between the axial unit vector of the satellite's beam at the terminal device and the line-of-sight vector; The fourth condition is related to the satellite's continuous availability time and a preset time threshold; the satellite's continuous availability time is the time during which the first condition, the second condition, and the third condition are simultaneously met and maintained.

4. The method according to claim 1, characterized in that, The step of selecting a target satellite for the terminal device to access from the first candidate satellite set includes: Based on the service type and attribute vector currently being executed by the terminal device, an initial weight vector and an initial attribute vector are determined; the attribute vector consists of multiple attributes; the multiple attributes include the satellite's continuous availability time, average elevation angle, the trend of changes in the satellite signal strength received by the terminal device, satellite capacity, and the risk of the terminal device losing connection with the satellite; Based on the initial weight vector and the initial attribute vector, the matching degree corresponding to each candidate satellite in the first candidate satellite set is determined; the matching degree is the matching degree between the initial attribute vector and the service type currently being executed by the terminal device. Based on the matching degree of each candidate satellite in the first candidate satellite set, a target satellite to be accessed is selected for the terminal device.

5. The method according to claim 4, characterized in that, The step of determining the initial weight vector and initial attribute vector based on the service type and attribute vector currently being executed by the terminal device includes: Select the corresponding initial weight vector based on the type of service currently being performed by the terminal device; Select attributes from the attribute vector that correspond to the service type currently being executed by the terminal device to form an initial attribute vector.

6. The method according to claim 4 or 5, characterized in that, The step of determining the matching degree corresponding to each candidate satellite in the first candidate satellite set based on the initial weight vector and the initial attribute vector includes: The initial weight vector and the preprocessed initial attribute vector are multiplied together, and the results of the multiplication are accumulated to obtain the matching degree corresponding to each candidate satellite in the first candidate satellite set; the preprocessed initial attribute vector is obtained by preprocessing the initial attribute vector.

7. The method according to claim 4 or 5, characterized in that, The step of selecting a target satellite for the terminal device to access based on the matching degree corresponding to each candidate satellite in the first candidate satellite set includes: If a satellite to be accessed is selected for the terminal device for the first time, the candidate satellite with the highest matching degree is selected from the first candidate satellite set as the target satellite.

8. The method according to claim 4 or 5, characterized in that, The step of selecting a target satellite for the terminal device to access based on the matching degree corresponding to each candidate satellite in the first candidate satellite set includes: If the terminal device is already connected to the target satellite and initiates a request to switch satellites, then a new target satellite to be connected is selected for the terminal device based on the updated initial weight vector, the switching success rate, and the first candidate satellite set; the updated initial weight vector is determined based on the initial weight vector.

9. The method according to claim 8, characterized in that, The method for obtaining the updated initial weight vector includes: The loss is determined based on key performance indicators, including the handover failure rate, the duration of disconnection between the terminal device and the satellite, and the average effective throughput of the terminal device. Based on the loss, each weight in the initial weight vector is adjusted to obtain the adjusted initial weight vector; Normalize each weight in the adjusted initial weight vector to obtain a normalized initial weight vector; The updated initial weight vector is obtained based on the initial weight vector, the normalized initial weight vector, and the smoothing coefficient.

10. The method according to claim 9, characterized in that, The step of adjusting each weight in the initial weight vector according to the loss to obtain the adjusted initial weight vector includes: Based on the loss and each weight in the initial weight vector, determine the approximate gradient of the loss corresponding to each weight in the initial weight vector; The updated initial weight vector is obtained by using each weight in the initial weight vector and its corresponding loss approximation gradient.

11. The method according to claim 8, characterized in that, The step of reselecting a target satellite for the terminal device to access based on the updated initial weight vector, the handover success rate, and the first candidate satellite set includes: If the success rate of switching of candidate satellites in the first candidate satellite set is less than a preset switching threshold, then the candidate satellites are removed from the first candidate satellite set to obtain a second candidate satellite set. Based on the time during which the matching degree of the candidate satellites in the second candidate satellite set is continuously greater than a first preset value, and a preset duration, a target satellite to be accessed is selected for the terminal device from the second candidate satellite set; the first preset value is related to the matching degree of the target satellites currently accessed by the terminal device.

12. The method according to claim 11, characterized in that, The method for obtaining the matching degree corresponding to the candidate satellites in the second candidate satellite set includes: The updated initial weight vector and the preprocessed initial attribute vector are multiplied together, and the results of the multiplication are accumulated to obtain the matching degree corresponding to the candidate satellites in the second candidate satellite set; the preprocessed initial attribute vector is the result of preprocessing the initial attribute vector.

13. The method according to claim 4 or 5, characterized in that, The method for obtaining the service type currently being executed by the terminal device includes: When the terminal device initiates a satellite access request, the access request information sent by the terminal device is identified to obtain the service type label, service quality parameters, or protocol signaling fields carried in the communication protocol corresponding to the terminal device. The type of service currently being executed by the terminal device is obtained based on the service type tag, quality of service parameters, or protocol signaling fields corresponding to the terminal device.

14. A satellite selection system, characterized in that, include: A terminal device trajectory prediction module is used to predict the motion trajectory of the terminal device based on the terminal device's current position information and motion information; the motion information includes velocity and / or acceleration. The satellite trajectory prediction module is used to predict the trajectory of the satellite based on its current position and motion information. The candidate satellite selection module is used to select a first set of candidate satellites for the terminal device based on the motion trajectory of the terminal device and the satellite; the first set of candidate satellites consists of candidate satellites; the candidate satellites are the satellites to be selected by the terminal device. The target satellite determination module is used to select a target satellite for the terminal device to access from the first candidate satellite set.

15. An electronic device, characterized in that, It includes a processor and a memory, the memory being used to store a computer program, and the processor being used to execute the computer program to implement the method as described in any one of claims 1-13.

16. A computer-readable storage medium, characterized in that, It includes a computer program or instructions that, when run on a computer, cause the computer to perform the method as described in any one of claims 1-13.

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