Satellite-ground link switching method and device of low-orbit satellite and electronic equipment

Abstract

The embodiment of the invention discloses a satellite-ground link switching method and device of a low-orbit satellite and electronic equipment. A specific embodiment of the method comprises the following steps: determining a candidate satellite window of each ground terminal according to a satellite ephemeris corresponding to a star chain and a satellite coverage range corresponding to the star chain; determining the link time of each candidate satellite in each candidate satellite window and a satellite-ground link of the corresponding ground terminal; determining satellite-ground link quality information of each candidate satellite and each ground terminal according to each service type of the ground terminal and the satellite-ground link link time of each candidate satellite; training the initial satellite-to-ground link switching network model to obtain a trained satellite-to-ground link switching network model; and in response to a received service switching instruction, inputting the quality information of each satellite-to-ground link into the satellite-to-ground link switching network model to determine a target switching satellite. According to the implementation mode, the ground terminal receiving signal strength, the satellite maximum serviceable time and the communication calculation service requirement can be directly optimized.

Description

Technical Field

[0001] The embodiments disclosed herein relate to the field of satellite-to-ground link handover, specifically to low-Earth orbit satellite satellite-to-ground link handover methods, apparatuses, and electronic devices. Background Technology

[0002] With the rapid development of satellite technology, many large low Earth orbit (LEO) satellite constellations have emerged, including Starlink, OneWeb, and GW. Due to the extensive coverage capabilities of satellite optical networks, they can establish network connections with remote areas that traditional terrestrial networks cannot reach. The large scale and dynamic characteristics of LEO satellite constellations lead to frequent satellite-to-ground link handovers. In recent years, the types of users of satellite networks have become increasingly diversified, and the number of users has continued to grow. Different types of users have different requirements for the performance of access satellites, link quality, and resource needs. These different requirements will pose significant challenges to user terminals in handling time-varying services during satellite-to-ground link handovers. Therefore, making an informed choice when selecting access satellites is crucial for achieving efficient satellite network services. Summary of the Invention

[0003] The summary portion of this disclosure is intended to provide a brief overview of the concepts, which will be described in detail in the detailed description portion. This summary portion is not intended to identify key or essential features of the claimed technical solutions, nor is it intended to limit the scope of the claimed technical solutions.

[0004] Some embodiments of this disclosure provide methods, apparatuses, electronic devices, and computer-readable media for switching low-Earth orbit satellite ground links to address the technical problems mentioned in the background section above.

[0005] In a first aspect, some embodiments of this disclosure provide a method for low-Earth orbit satellite-to-ground link handover. The method includes: determining a candidate satellite window for each ground terminal based on the satellite ephemeris and coverage area corresponding to the Starlink satellite, wherein the candidate satellite window contains multiple candidate satellites; determining the satellite-to-ground link connection time between each candidate satellite in each candidate satellite window and the corresponding ground terminal; determining the satellite-to-ground link quality information between each candidate satellite and each ground terminal based on the various service types of the ground terminal and the satellite-to-ground link connection time of each candidate satellite; training an initial satellite-to-ground link handover network model to obtain a trained satellite-to-ground link handover network model; and, in response to receiving a service handover instruction, inputting the satellite-to-ground link quality information into the satellite-to-ground link handover network model to determine the target satellite for handover.

[0006] Secondly, some embodiments of this disclosure provide a low-Earth orbit satellite-to-ground link handover device. The device includes: a first determining unit configured to determine a candidate satellite window for each ground terminal based on the satellite ephemeris and coverage area corresponding to the Starlink satellite, wherein the candidate satellite window contains multiple candidate satellites; a second determining unit configured to determine the satellite-to-ground link connection time between each candidate satellite in each candidate satellite window and the corresponding ground terminal; a third determining unit configured to determine the satellite-to-ground link quality information between each candidate satellite and each ground terminal based on the various service types of the ground terminal and the satellite-to-ground link connection time of each candidate satellite; a training unit configured to train an initial satellite-to-ground link handover network model to obtain a trained satellite-to-ground link handover network model; and an input unit configured to input the various satellite-to-ground link quality information into the satellite-to-ground link handover network model in response to receiving a service handover command, so as to determine the target handover satellite.

[0007] Thirdly, some embodiments of this disclosure provide an electronic device, including: one or more processors; and a storage device having one or more programs stored thereon, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the method described in any implementation of the first aspect above.

[0008] Fourthly, some embodiments of this disclosure provide a computer-readable medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the method described in any of the implementations of the first aspect above.

[0009] The various embodiments disclosed above have the following beneficial effects: The low-Earth orbit satellite-to-ground link handover method of some embodiments of this disclosure can directly optimize the signal strength received by the ground terminal, the maximum service time of the satellite, and the requirements of the inductive computing service; the optimization of the signal strength received by the ground terminal improves the handover success rate for users; the optimization of the maximum service time of the satellite can reduce the handover frequency; the optimization of the inductive computing service requirements can effectively balance the needs of multiple services and improve the satisfaction of ground terminal users; in summary, establishing a multi-service objective optimization model improves the handover success rate of the ground terminal, reduces the handover frequency, and ensures the service satisfaction of the ground terminal. By using DRQN, data with time-series characteristics can be processed, and implicit patterns in the satellite network can be learned based on historical observation data. Since LSTM can aggregate historical state information, the DRQN ​​strategy can take into account the impact of handover actions in historical time slots more comprehensively, thus achieving a lower handover frequency than DQN in selecting access satellites. Attached Figure Description

[0010] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and elements are not necessarily drawn to scale.

[0011] Figure 1 This is a flowchart of some embodiments of the low-Earth orbit satellite space-to-ground link handover method according to this disclosure;

[0012] Figure 2 This is a schematic diagram of the satellite's position vector relative to the ground terminal;

[0013] Figure 3 This is a schematic diagram of a satellite-to-ground link handover network model;

[0014] Figure 4 This is a schematic diagram of a ground terminal switching to satellite access;

[0015] Figure 5 This is a schematic diagram of the structure of some embodiments of the low-Earth orbit satellite space-to-ground link switching device according to the present disclosure;

[0016] Figure 6 This is a schematic diagram of the structure of an electronic device suitable for implementing some embodiments of the present disclosure. Detailed Implementation

[0017] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0018] It should also be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. Unless otherwise specified, the embodiments and features described in this disclosure can be combined with each other.

[0019] It should be noted that the concepts of "first" and "second" mentioned in this disclosure are used only to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0020] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0021] The names of messages or information exchanged between multiple devices in the embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of such messages or information.

[0022] This disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] Figure 1 This is a flowchart 100 of some embodiments of the low-Earth orbit satellite-to-ground link handover method disclosed herein. The low-Earth orbit satellite-to-ground link handover method includes the following steps:

[0024] Step 101: Determine the candidate satellite window for each ground terminal based on the satellite ephemeris and coverage area of ​​the Starlink satellites.

[0025] In some embodiments, the execution entity (e.g., a computing device) of the low-Earth orbit (LEO) satellite-to-ground link switching method can determine a candidate satellite window for each ground terminal based on the satellite ephemeris and coverage area corresponding to Starlink. This candidate satellite window contains multiple candidate satellites. For example, real-time on-orbit TLE data of Starlink can be obtained from the CeleTrack website. Analyzing the TLE data yields the trajectory of each satellite, and based on a satellite coverage model, it can be calculated which LEO satellites each ground terminal can establish a satellite-to-ground link with, ultimately forming a selectable satellite visibility window. A ground terminal can refer to a ground observation station. One ground terminal corresponds to one candidate satellite window.

[0026] For example, the visible satellite window for each ground terminal can be calculated based on satellite ephemeris (i.e., satellite-related data obtained from TLE data analysis) and satellite coverage. Satellite ephemeris data contains basic satellite information, including launch time, name, and orbital altitude. Other orbital parameters, such as semi-major axis and true anomaly, can also be derived. Based on the elevation angle of the ground terminal, it can be determined whether the satellite is visible to the ground terminal, ultimately forming a candidate satellite window, which can be represented as Sat={sat1,sat2,…,sat…}. N The TLE data contains basic satellite information, including launch time, name, and orbital altitude. Other orbital parameters, such as semi-major axis and true anomaly, can also be derived. Based on the elevation angle of the ground terminal, it can be determined whether the satellite is visible to the ground terminal. When the elevation angle of the ground terminal is greater than the minimum elevation angle requirement of the satellite, the ground terminal is considered to be covered by the satellite.

[0027] TLE data can include:

[0028] Satellite ID (NORAD ID): A unique identifier for a satellite (such as STARLINK-1234) that identifies a specific satellite;

[0029] Orbital inclination: The angle between the satellite's orbital plane and the Earth's equatorial plane (unit: degrees). It determines the latitudinal range covered by the satellite (the larger the inclination, the stronger the ability to cover polar regions).

[0030] Right ascension of the ascending node (angle of the RAAN satellite orbital plane and the equatorial plane at the vernal equinox (unit: degrees): used to calculate the satellite's initial phase and, combined with time, to estimate its orbital position;

[0031] Eccentricity: A measure of how flattened the orbital ellipse is (0 for a circular orbit). It corrects for perigee and apogee altitudes (LEO satellites are typically close to 0).

[0032] Arg of Perigee: The angle of perigee relative to the ascending node (unit: degrees). It locates the point on the orbit closest to Earth.

[0033] Mean Anomaly: The average angular position (in degrees) of a satellite over its orbital period, combined with epoch time to calculate the satellite's instantaneous position;

[0034] Mean Motion: The number of orbits a satellite makes around the Earth per day (unit: orbits / day). Key parameter → Calculate orbital period: $T = \frac{24 \times 3600}{\text{Mean Motion}}$ (seconds);

[0035] Epoch: The reference time for the release of TLE data (format: YYDDD.DDDDDDDD) serves as the base time for calculating orbital parameters.

[0036] Step 102: Determine the satellite-to-ground link time between each candidate satellite in each candidate satellite window and the corresponding ground terminal.

[0037] In some embodiments, the aforementioned execution entity may determine the satellite-to-ground link time between each candidate satellite in each candidate satellite window and the corresponding ground terminal.

[0038] In practice, the aforementioned implementing entity can determine the satellite-to-ground link time between each candidate satellite and its corresponding ground terminal within each candidate satellite window through the following steps:

[0039] The first step is to obtain the ground location information of the ground terminal and the satellite location information of the aforementioned candidate satellites. The ground location information includes latitude, longitude, and altitude, while the satellite location information includes latitude, longitude, and altitude. For example, the latitude, longitude, and altitude information of the ground terminal and candidate satellites obtained based on GPS positioning information are defined as follows: and . This indicates the ground location information (latitude, longitude, and altitude) of the ground terminal. This indicates the satellite location information (latitude, longitude, and altitude) of the candidate satellite.

[0040] The second step involves using the ground as the center and a fixed coordinate system, based on the aforementioned ground location information and satellite location information, and employing the spherical right triangle and the spherical cosine theorem to calculate the satellite-to-ground link time (maximum service time) between the candidate satellite and the aforementioned ground terminal.

[0041] Depend on Figure 2 As shown in the example, the satellite-to-ground link time can be defined as: ,in, This represents the longest radian that the satellite can serve the ground terminal. In a ground-centered, fixed-ground (ECEF) coordinate system, , where ω s and ω E These are the angular velocities of the satellite and Earth, respectively, in Earth's inertial coordinate system. Based on the spherical right triangle and the law of cosines, we can obtain the function ψ. ,in, Solve this problem. The process consists of two steps. First, the orbital root numbers are parsed from the TLE data to obtain the latitude, longitude, and altitude information of the satellite footprints. Then, the distance between each satellite and the user terminal is determined. The nearest point is represented as ,Record The location is represented as follows, based on the current location of the user terminal. In a Cartesian coordinate system, three points determine a plane, so this section selects... The footprint data of the three sets of satellites at that time were used to calculate This converts the original information into coordinate data in a geocentric-fixed coordinate system. It can be represented as:

[0042]

[0043]

[0044] Among them, The radius is the equatorial radius. For Earth's eccentricity, the user terminal coordinates and the footprint coordinates of the three selected satellites This can be used to construct a three-dimensional Cartesian coordinate system. Using these known coordinate points, the formula can be obtained. ,Right now:

[0045]

[0046] This allows us to calculate the current user terminal using the point-distance formula. Distance to the plane closest to the sub-star point It can be expressed by the following formula:

[0047]

[0048] Therefore, according to the inverse cosine theorem, we can obtain... , used for calculation This allows us to obtain the satellite-to-ground link connection time.

[0049]

[0050] Step 103: Based on the various service types of the ground terminal and the satellite-to-ground link connection time of each candidate satellite, determine the satellite-to-ground link quality information between each candidate satellite and each ground terminal.

[0051] In some embodiments, the aforementioned execution entity can determine the satellite-to-ground link quality information between each candidate satellite and each ground terminal based on the satellite-to-ground link connection time between each candidate satellite and each of the various service types of the ground terminal. The service types of the ground terminal are divided into three categories: communication service type, sensing service type, and computing service type. Communication services require low latency and therefore have high requirements for distance and link quality. Sensing services require sensor resources from the access satellite to meet the service's sensor resource requirements. Computing services have corresponding requirements for the satellite's computing resources. The ground terminal will switch access satellites in three situations: (1) the satellite currently accessed by the ground terminal is not visible in the next time slice; (2) the resources of the satellite currently accessed by the ground terminal are insufficient to serve the current ground terminal's service; (3) the channels of the satellite currently accessed by the ground terminal are insufficient. When any of the above three situations occur, the ground terminal needs to reselect the access satellite to ensure that the satellite-to-ground link can be constructed normally.

[0052] After standardizing the three service requirements, a unified definition of satellite-to-ground link quality information is formed:

[0053] .

[0054] in, This represents the satellite-to-ground link quality information (service satisfaction index) between ground terminal m and candidate satellite n at time slice t; m represents the index of the ground terminal; n represents the index of the candidate satellite; t represents the index of the time slice; k represents the index of the influencing factors considered, from 1 to K; K is the total number of impression factors (here it is 4, because F takes four factors: ); This represents the signal strength (signal-to-noise ratio) of candidate satellite n and ground terminal m at time slice t. This indicates the load status of satellite n at time slice t (e.g., available bandwidth or current load intensity). This represents the available computing resources (e.g., remaining CPU computing power) for satellite n in time slice t; This represents the available sensor resources for satellite n at time slice t. t represents real-time, indicating a specific point in time. T represents the maximum service time (satellite-to-ground link time) for a given satellite to a ground terminal at that point in time. In other words, at time t, the maximum service time for a given satellite to a ground terminal can be calculated as T.

[0055] .

[0056] in, The binary decision variable represents whether ground terminal m connects to candidate satellite n at time slice t (1 indicates connection, 0 indicates no connection); T represents the total number of time slices (optimization cycle); M represents the number of ground terminals; and N represents the number of candidate satellites.

[0057] .

[0058] in, Let m be the binary decision variable, representing whether ground terminal m connects to candidate satellite n at time slice t (1 indicates connection, 0 indicates no connection); m represents the index of the ground terminal; n represents the index of the candidate satellite; t represents the index of the time slice; M represents the total number of ground terminals; N represents the total number of satellites; and T represents the total number of time slices.

[0059] .

[0060] in: Let m be the binary decision variable, representing whether ground terminal m connects to candidate satellite n at time slice t (1 indicates connection, 0 indicates no connection); m represents the index of the ground terminal; n represents the index of the candidate satellite; t represents the index of the time slice; M represents the total number of ground terminals; N represents the total number of satellites; and T represents the total number of time slices.

[0061] Where C1 represents the visibility constraint, the selected satellite must be a currently visible satellite, and C2 represents the current satellite must meet the channel requirements.

[0062] Step 104: Train the initial satellite-to-ground link handover network model to obtain the trained satellite-to-ground link handover network model.

[0063] In some embodiments, the aforementioned execution entity can train the initial satellite-to-ground link handover network model to obtain a trained satellite-to-ground link handover network model. The initial satellite-to-ground link handover network model can refer to an incompletely trained DAQN network model. The DRQN ​​network model combines the advantages of Deep Q-Networks (DQN) and Recurrent Neural Networks (RNNs), particularly utilizing the historical state aggregation capability of Long Short-Term Memory (LSTM) neural networks within RNNs. This enables DRQN ​​to process data with time-series characteristics and learn implicit patterns in satellite networks based on historical observation data.

[0064] DRQN model such as Figure 3 As shown, it mainly consists of three parts: environmental state, action space, and reward value. In the satellite network link, the environmental state is the current state of the low-Earth orbit satellite, which is composed of satellite signal strength, coverage area, and resource availability. The action space refers to the access satellites that the ground terminal can choose to access. The reward value is calculated based on the access satellites selected by the ground terminal using a reward function and is used to train the model.

[0065] In practice, the aforementioned implementing entities can train the initial satellite-to-ground link handover network model through the following steps:

[0066] The first step is to initialize the environment state, action space, and reward function of the initial satellite-to-ground link handover network model described above. For example, this can be divided according to time slices, using symbols... Indicates ground terminal U m The network status of low-Earth orbit satellites observable in the current time slot t can be expressed by the following mathematical formula:

[0067] .

[0068] in, This indicates the current switching status between the satellite and the ground terminal. This indicates the signal quality at which the candidate satellite establishes a link with the ground terminal. Indicates the current channel capacity of the candidate satellite. This represents the remaining computing resources for the candidate satellite. This indicates the current sensor resources of the candidate satellite.

[0069] Based on the observed network state Ground terminal U m The selection of access link handover actions is based on the DRQN ​​model, and the action selection space is defined as follows:

[0070] .

[0071] Where L is the number of candidate satellites in the candidate satellite window, and the agent will receive a corresponding reward after making a link switching decision in time slot t. The reward function is set as follows:

[0072] .

[0073] in, This represents the minimum signal strength required to construct a satellite-to-ground link, which, after receiving a reward, can form a quadruple. As an experience gained from an execution, it is placed into the experience buffer pool.

[0074] The second step is to initialize the target network and evaluation network of the initial satellite-to-ground link handover network model described above. The target network is used to calculate the target value, and the evaluation network is used by the ground terminal to generate the currently selected access satellite. Initializing the target network and evaluation network—the evaluation network for generating the currently selected access satellite by the ground terminal, and the target network for calculating the target Q-value—stabilizes the training process. In the DRQN ​​model, the input layer is composed of LSTM units, which can store and update information long-term, thereby extracting the time-related periodic characteristics of the low-Earth orbit satellite network. The target network and evaluation network each include: an input layer, an LSTM layer, a fully connected layer, and an output layer.

[0075] The third step is to train the initial satellite-to-ground link handover network model after initialization to obtain the trained satellite-to-ground link handover network model.

[0076] In practice, the aforementioned execution entity can use a greedy exploration strategy to select switching actions, obtain reward values ​​through a reward function, form a set of training samples and put them into an experience buffer pool, and use a gradient descent method to train the network parameters of the evaluation network. Every preset time interval, the network parameters are updated to the evaluation network of each ground terminal.

[0077] For example, during the training phase, the ground terminal observes the current environmental state. In each round, an ε-greedy strategy is used to select an access satellite. The ε-greedy strategy randomly selects an access satellite with a certain probability ε to explore new states; it selects the access satellite that the current Q network considers the best with a probability of 1-ε; it executes actions to establish a satellite-to-ground link with the access satellite and observes the new state. The reward and whether the termination state has been reached will be considered. (This will be converted.) Stored in the playback buffer.

[0078] Next, a batch of transformed samples is randomly selected from the playback buffer, and the target network is used to calculate the target value (target Q-value). The parameters of the evaluation network are then updated using gradient descent to minimize the difference between the predicted Q-value and the target Q-value. The formula for calculating the target value is as follows:

[0079] .

[0080] in, The target Q value at the current time step t is used to calculate the training loss. γ represents the immediate reward the agent receives after performing an action at time step t. γ represents the discount factor, used to balance short-term and long-term rewards (0 < γ < 10 < 10). This represents the next state that the agent reaches after performing an action. This indicates that the evaluation network evaluates the state. Q-value estimation for all possible actions a, with parameters as follows: . This represents the target network, used to calculate the target Q-value, and its parameters are: This is to ensure the stability of the training.

[0081] At regular intervals, the parameters of the evaluation network are copied to the target network to maintain the stability of the target Q value.

[0082] Step 105: In response to receiving the service switching instruction, input the quality information of each satellite-to-ground link into the above-mentioned satellite-to-ground link switching network model to determine the target switching satellite.

[0083] In some embodiments, the aforementioned execution entity may, in response to receiving a service switching instruction, input the quality information of each satellite-to-ground link (current time slice status information (visible satellite set information, link quality of each visible satellite, link delay, remaining channel bandwidth, remaining computing resources, remaining satellite coverage duration), current user service requirement parameters, and historical link status sequences) into the aforementioned satellite-to-ground link switching network model to determine the target switching satellite. Further reference... Figure 4 When one of the three necessary switching scenarios occurs, the ground terminal will perform status monitoring based on the local network model and calculate the Q-value based on the network model. It will then select the best access satellite from the candidate satellite window that meets the current service requirements. If no satellite meets the service requirements at this time, the switch fails, and the satellite with the longest maximum service time will be selected as the switching satellite. The switching decision will be re-evaluated in the next time slot. For example, Figure 4 Ground terminal All connected satellites will be switched to other satellites. Among them, there are three situations: (1) the satellite currently connected to the ground terminal is not visible in the next time slice; (2) the resources of the satellite currently connected to the ground terminal are insufficient to serve the services of the current ground terminal; (3) the channels of the satellite currently connected to the ground terminal are insufficient.

[0084] Further reference Figure 5 As an implementation of the methods shown in the above figures, this disclosure provides some embodiments of a low-Earth orbit satellite-to-ground link switching device, which are similar to... Figure 1 Corresponding to the method embodiments shown, this low-Earth orbit satellite-to-ground link switching device can be specifically applied to various electronic devices.

[0085] like Figure 5 As shown, a low-Earth orbit satellite-to-ground link switching device 500 in some embodiments includes: a first determining unit 501, a second determining unit 502, a third determining unit 503, a training unit 504, and an input unit 505. The first determining unit 501 is configured to determine a candidate satellite window for each ground terminal based on the satellite ephemeris and coverage area corresponding to the Starlink satellite, wherein the candidate satellite window contains multiple candidate satellites. The second determining unit 502 is configured to determine the satellite-to-ground link connection time between each candidate satellite in each candidate satellite window and the corresponding ground terminal. The third determining unit 503 is configured to determine the satellite-to-ground link quality information between each candidate satellite and each ground terminal based on the various service types of the ground terminal and the satellite-to-ground link connection time of each candidate satellite. The training unit 504 is configured to train an initial satellite-to-ground link switching network model to obtain a trained satellite-to-ground link switching network model. The input unit 505 is configured to, in response to receiving a service switching command, input the satellite-to-ground link quality information into the satellite-to-ground link switching network model to determine the target switching satellite.

[0086] It is understandable that the units described in the low-Earth orbit satellite ground link switching device 500 are related to the reference... Figure 1 The steps in the described method correspond accordingly. Therefore, the operations, features, and beneficial effects described above for the method also apply to the low-Earth orbit satellite space-to-ground link switching device 500 and the units contained therein, and will not be repeated here.

[0087] The following is for reference. Figure 6 It illustrates a schematic diagram of the structure of an electronic device (such as a computing device) suitable for implementing some embodiments of the present disclosure. Figure 6 The electronic device shown is merely an example and should not be construed as limiting the functionality or scope of the embodiments of this disclosure. Figure 6As shown, the computer device includes a processor, memory, and network interface connected via a system bus. The memory may include non-volatile storage media and internal memory. The non-volatile storage media may store the operating system and computer programs. The computer programs include program instructions that, when executed, cause the processor to perform any low-Earth orbit satellite-to-ground link handover method. The processor provides computing and control capabilities to support the operation of the entire computer device. The internal memory provides an environment for the execution of the computer programs in the non-volatile storage media; when executed by the processor, these programs cause the processor to perform any low-Earth orbit satellite-to-ground link handover method. The network interface is used for network communication, such as sending assigned tasks. Those skilled in the art will understand that... Figure 6 The structure shown is merely a block diagram of a portion of the structure related to the present disclosure and does not constitute a limitation on the computer device to which the present disclosure is applied. A specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0088] It should be understood that the processor can be a Central Processing Unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. Among these, a general-purpose processor can be a microprocessor or any conventional processor.

[0089] In one embodiment, the processor is configured to run a computer program stored in a memory to perform the following steps: determining a candidate satellite window for each ground terminal based on the satellite ephemeris and coverage area corresponding to Starlink, wherein the candidate satellite window contains multiple candidate satellites; determining the satellite-to-ground link link time between each candidate satellite in each candidate satellite window and the corresponding ground terminal; determining the satellite-to-ground link quality information between each candidate satellite and each ground terminal based on the various service types of the ground terminal and the satellite-to-ground link link time of each candidate satellite; training an initial satellite-to-ground link handover network model to obtain a trained satellite-to-ground link handover network model; and, in response to receiving a service handover instruction, inputting the satellite-to-ground link quality information into the satellite-to-ground link handover network model to determine the target handover satellite.

[0090] This disclosure also provides a computer-readable storage medium storing a computer program, which includes program instructions. When the program instructions are executed, the method implemented can be referred to various embodiments of the low-Earth orbit satellite-to-ground link switching method of this disclosure.

[0091] The aforementioned computer-readable storage medium may be an internal storage unit of the computer device described in the foregoing embodiments, such as the hard disk or memory of the computer device. Alternatively, the aforementioned computer-readable storage medium may be an external storage device of the computer device, such as a plug-in hard disk, SmartMedia Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the computer device.

[0092] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0093] The above description is merely a selection of preferred embodiments of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in the embodiments of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in the embodiments of this disclosure.

Claims

1. A method for switching low-Earth orbit satellite-to-ground links, characterized in that, include: Based on the satellite ephemeris and coverage area of ​​Starlink, a candidate satellite window is determined for each ground terminal, wherein the candidate satellite window contains multiple candidate satellites; Determine the satellite-to-ground link time between each candidate satellite in each candidate satellite window and the corresponding ground terminal; Based on the various service types of the ground terminal and the satellite-to-ground link connection time of each candidate satellite, determine the satellite-to-ground link quality information between each candidate satellite and each ground terminal; The initial satellite-to-ground link handover network model is trained to obtain the trained satellite-to-ground link handover network model. In response to receiving a service switching instruction, the quality information of each satellite-to-ground link is input into the satellite-to-ground link switching network model to determine the target switching satellite.

2. The method according to claim 1, characterized in that, Determining the satellite-to-ground link time between each candidate satellite in each candidate satellite window and the corresponding ground terminal includes: The ground location information of the ground terminal and the satellite location information of the candidate satellite are obtained, wherein the ground location information includes latitude, longitude and altitude, and the satellite location information includes latitude, longitude and altitude; Centered on the ground, in a fixed coordinate system, based on the ground location information and the satellite location information, the satellite-to-ground link time between the candidate satellite and the ground terminal is calculated using a spherical right triangle and the spherical cosine theorem.

3. The method according to claim 2, characterized in that, The process of training the initial satellite-to-ground link handover network model to obtain the trained satellite-to-ground link handover network model includes: Initialize the environment state, action space, and reward function of the initial satellite-to-ground link switching network model; The target network and evaluation network of the initial satellite-to-ground link switching network model are initialized, wherein the target network is used to calculate the target value, and the evaluation network is used by the ground terminal to generate the currently selected access satellite; The initial satellite-to-ground link handover network model after initialization is trained to obtain the trained satellite-to-ground link handover network model.

4. The method according to claim 3, characterized in that, The step of training the initial satellite-to-ground link handover network model after initialization to obtain the trained satellite-to-ground link handover network model includes: A greedy exploration strategy is used to select switching actions, and a reward value is obtained through a reward function. These are then used to form a set of training samples and placed into an experience buffer pool. The network parameters of the evaluation network are trained using a gradient descent method. Every preset time interval, the network parameters are updated to the evaluation network of each ground terminal.

5. A low-Earth orbit satellite-to-ground link switching device, characterized in that, include: The first determining unit is configured to determine a candidate satellite window for each ground terminal based on the satellite ephemeris and the satellite coverage area corresponding to Starlink, wherein the candidate satellite window contains multiple candidate satellites. The second determining unit is configured to determine the satellite-to-ground link link time between each candidate satellite in each candidate satellite window and the corresponding ground terminal; The third determining unit is configured to determine the satellite-to-ground link quality information between each candidate satellite and each ground terminal based on the satellite-to-ground link link time between each service type of the ground terminal and each candidate satellite. The training unit is configured to train the initial satellite-to-ground link handover network model to obtain the trained satellite-to-ground link handover network model. The input unit is configured to input the quality information of each satellite-to-ground link into the satellite-to-ground link switching network model in response to receiving a service switching command, so as to determine the target switching satellite.

6. An electronic device, characterized in that, include: One or more processors; A storage device on which one or more programs are stored; When the one or more programs are executed by the one or more processors, the one or more processors implement the method as described in any one of claims 1 to 4.

7. A computer-readable medium, characterized in that, It stores a computer program thereon, wherein the computer program, when executed by a processor, implements the method as described in any one of claims 1 to 4.

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