Satellite switching method, device and equipment, computer storage medium and program product

Abstract

The invention discloses a satellite switching method, device and equipment, a computer storage medium and a program product. The method comprises the following steps under the condition that communication parameters of a current service satellite meet a first switching condition: sending current state information of a ground terminal to a ground station; receiving response information from the ground station; the first candidate satellite set is determined by calculating the coverage range of each satellite by the ground station according to communication parameters reported by a plurality of satellites and screening satellites of which the coverage ranges accord with preset conditions from other satellites for the current service satellite; screening target satellites meeting screening conditions from the first candidate satellite set based on the communication parameters of the candidate satellites; the first switching condition and the screening condition correspond to communication parameters of the current service satellite; and switching the current service satellite to the target satellite. According to the embodiment of the invention, more objective and accurate satellite switching matched with service requirements can be realized on the premise of not increasing hardware burden.

Description

Technical Field

[0001] This application belongs to the field of satellite handover technology, and in particular relates to a satellite handover method, apparatus, equipment, computer storage medium and program product. Background Technology

[0002] Satellite communication technology, as an important supplement to terrestrial cellular networks, is widely used in scenarios where terrestrial signals are difficult to cover, such as maritime, aviation, and remote areas, providing reliable connectivity for fields such as the Internet of Things and emergency communications. In satellite communication systems, due to the relative motion between satellites and ground terminals, terminals need to switch from the currently serving satellite to another satellite after a certain period of time to maintain communication continuity. Therefore, inter-satellite handover technology has become a crucial link in ensuring communication quality and stability.

[0003] Currently, existing satellite handover methods mainly fall into two categories: single-attribute decision-making and multi-attribute decision-making. Single-attribute handover methods, such as the maximum elevation angle method and the longest remaining service time method, make handover decisions based on only a single parameter. While simple to implement, they often struggle to accommodate diverse communication needs. In recent years, some multi-attribute handover schemes have also emerged. For example, some schemes select handover paths by constructing weighted directed graphs, while others utilize deep reinforcement learning models to generate handover decisions, attempting to make a more comprehensive trade-off among multiple parameters.

[0004] However, existing technologies still have some significant problems: single-attribute handover methods, failing to comprehensively consider multiple factors such as signal quality, remaining service time, and bandwidth resources, are prone to unstable communication quality or excessively frequent handovers after handover; while some multi-attribute handover methods either rely on additional hardware for signal measurement, increasing system power consumption and cost, or employ subjective weighting for multi-attribute fusion, resulting in insufficient objectivity and accuracy in handover decisions and difficulty in adapting to the diverse service needs of terminals. Therefore, how to achieve more objective, accurate, and service-oriented satellite handover without increasing hardware burden has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] This application provides a satellite handover method, apparatus, device, computer storage medium, and program product that can achieve more objective, accurate, and business-compatible satellite handover without increasing hardware burden.

[0006] On one hand, this application provides a satellite handover method, which is executed by a ground terminal and includes the following steps when the communication parameters of the currently serving satellite meet a first handover condition: sending the current status information of the ground terminal to a ground station; receiving response information from the ground station; wherein the response information includes a first candidate satellite set and the communication parameters of each candidate satellite; the first candidate satellite set is determined by the ground station calculating the coverage range of each satellite based on the communication parameters reported by multiple satellites, and selecting satellites whose coverage range meets preset conditions from other satellites for the currently serving satellite; selecting target satellites that meet the selection conditions from the first candidate satellite set based on the communication parameters of each candidate satellite; wherein the first handover condition and the selection condition correspond to the communication parameters of the currently serving satellite; and when the target satellite is different from the currently serving satellite, switching the currently serving satellite to the target satellite.

[0007] In some possible implementations, before selecting target satellites that meet the selection criteria from the first candidate satellite set based on the communication parameters of each candidate satellite, the method further includes: configuring corresponding second switching conditions for multiple satellite communication parameters based on the service requirements of the current serving satellite communication; selecting candidate satellites in the first candidate satellite set based on the second switching conditions to obtain a second candidate satellite set; and selecting target satellites that meet the selection criteria from the first candidate satellite set based on the communication parameters of each candidate satellite, including: selecting target satellites that meet the selection criteria from the second candidate satellite set based on the communication parameters of each candidate satellite when the second candidate satellite set is not empty.

[0008] In some possible implementations, the communication parameters include remaining bandwidth resources, the first switching condition includes remaining bandwidth resources being less than a first preset threshold, and the target satellite that meets the screening conditions is selected from the first candidate satellite set based on the communication parameters of each candidate satellite, including: selecting the candidate satellite with the highest remaining bandwidth resources from the first candidate satellite set as the target satellite.

[0009] In some possible implementations, the communication parameters include the remaining service time, the first switching condition includes the remaining service time being less than a second preset threshold, and the target satellite that meets the screening conditions is selected from the first candidate satellite set based on the communication parameters of each candidate satellite, including: selecting the candidate satellite with the longest remaining service time from the first candidate satellite set as the target satellite.

[0010] In some possible implementations, the communication parameters include the remaining service time, the first handover condition includes the remaining service time being less than a third preset threshold, and the target satellite that meets the screening condition is selected from the first candidate satellite set based on the communication parameters of each candidate satellite, including: performing a weighted calculation on the communication parameters of each candidate satellite in the first candidate satellite set to obtain multiple scores; and selecting the candidate satellite with the highest score as the target satellite.

[0011] In some possible implementations, before the satellite communication parameters of the currently serving satellite meet the first switching condition, for each candidate satellite in the first candidate satellite set, the method further includes: obtaining the initial time when the ground terminal enters the coverage area of ​​the candidate satellite; wherein the initial time is calculated by the ground station and transmitted by the currently serving satellite; obtaining the orbital parameters of the candidate satellite and calculating the maximum coverage time of the candidate satellite for the ground terminal; and calculating the remaining service time of the candidate satellite based on the initial time and the maximum coverage time, combined with the current time.

[0012] In some possible implementations, the communication parameters include signal quality, the first switching condition includes signal quality being less than a fourth preset threshold, and the target satellite that meets the screening conditions is selected from the first candidate satellite set based on the communication parameters of each candidate satellite, including: performing a weighted calculation on the communication parameters of each candidate satellite in the first candidate satellite set to obtain multiple scores; and selecting the candidate satellite with the highest score as the target satellite.

[0013] On the other hand, embodiments of this application provide a satellite switching device, comprising: a condition judgment module for judging whether the communication parameters of the currently serving satellite meet a first switching condition; an information sending module for sending the current status information of the ground terminal to a ground station; an information receiving module for receiving response information from the ground station; wherein the response information includes a first candidate satellite set and the communication parameters of each candidate satellite; the first candidate satellite set is determined by the ground station calculating the coverage range of each satellite based on the communication parameters reported by multiple satellites, and selecting satellites whose coverage range meets preset conditions from other satellites for the currently serving satellite; a satellite filtering module for filtering target satellites that meet the filtering conditions from the first candidate satellite set based on the communication parameters of each candidate satellite; wherein the first switching condition and the filtering condition correspond to the communication parameters of the currently serving satellite; and a satellite switching module for switching the currently serving satellite to the target satellite when the target satellite is different from the currently serving satellite.

[0014] In another aspect, embodiments of this application provide an electronic device, the device including: a processor and a memory storing computer program instructions; the processor executes the computer program instructions to implement a satellite switching method.

[0015] In another aspect, embodiments of this application provide a computer storage medium on which computer program instructions are stored, and when the computer program instructions are executed by a processor, a satellite handover method is implemented.

[0016] In another aspect, embodiments of this application provide a computer program product in which instructions, when executed by the processor of an electronic device, cause the electronic device to perform a satellite handover method.

[0017] The satellite handover method, apparatus, device, and computer storage medium of this application embodiment involve a ground station calculating the coverage area and determining a first candidate satellite set based on the communication parameters reported by each satellite. The communication parameters of the candidate satellites are sent by the ground station. The collaborative architecture between the ground station and the ground terminal allows the ground terminal to obtain the required data without additional hardware, avoiding the increased cost and power consumption caused by additional hardware. Furthermore, by designing the selection conditions to correspond to the communication parameters of the currently serving satellite, the triggering of satellite handover is based entirely on the actual communication status of the satellite, ensuring the necessity and accuracy of handover initiation. When selecting target satellites, the aim is always to address the deficiencies in the communication parameters of the currently serving satellite, objectively matching the terminal service's requirements for key parameters, avoiding subjective weighting bias, and significantly improving the objectivity and service adaptability of handover decisions. Thus, without increasing the hardware burden, a more objective, accurate, and service-compliant satellite handover is achieved. Attached Figure Description

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

[0019] Figure 1 This is a flowchart illustrating a satellite handover method provided in one embodiment of this application; Figure 2 This is a flowchart illustrating a satellite handover method provided in another embodiment of this application; Figure 3 This is a flowchart illustrating a satellite handover method provided in yet another embodiment of this application; Figure 4 This is a schematic diagram of the structure of a satellite switching device provided in another embodiment of this application; Figure 5 This is a schematic diagram of the structure of an electronic device provided in another embodiment of this application. Detailed Implementation

[0020] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0021] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus 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 apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0022] In satellite communication scenarios, the topology between satellites and ground terminals changes dynamically. Satellite coverage, remaining service time, bandwidth resources, and communication signal quality all fluctuate in real time. Terminal handover decisions must simultaneously adapt to this dynamic characteristic and the diverse communication performance requirements of various services. Existing single-attribute handover methods focus only on a single indicator (such as maximum elevation angle, longest remaining service time, etc.), failing to recognize the interrelationships and synergies among multiple factors such as signal quality, remaining service time, and bandwidth resources. For example, pursuing only the maximum elevation angle may lead to insufficient bandwidth resources, while focusing solely on remaining service time may ignore signal stability. This one-sided decision-making logic cannot balance multi-dimensional performance requirements, inevitably leading to problems such as unstable communication quality after handover and excessively frequent handover triggers.

[0023] For multi-attribute switching methods, existing technologies have failed to effectively resolve the core contradiction between "hardware dependence" and "objectivity of weighting": On the one hand, some solutions acquire signal quality data by additionally equipping phased array antennas, parabolic antennas, and other hardware devices, without realizing that this approach increases terminal power consumption and hardware costs, and is difficult to adapt to application scenarios of lightweight terminals; on the other hand, some solutions use subjective weighting or rely on large amounts of data and high-computing-power algorithm models for multi-attribute fusion, without considering that subjective weighting is easily affected by human factors and cannot truly reflect the objective importance of satellite parameters, while the high computing power requirement limits its deployment feasibility on ordinary terminals, ultimately resulting in insufficient adaptation between switching decisions and actual terminal business needs, making it difficult to meet the precise switching requirements in diverse scenarios.

[0024] In the satellite handover method of this application embodiment, the ground station calculates the coverage area and determines the first candidate satellite set based on the communication parameters reported by each satellite. The communication parameters of the candidate satellites are sent by the ground station. The collaborative architecture between the ground station and the ground terminal enables the ground terminal to obtain the required data without the need for additional hardware, avoiding the increased cost and power consumption caused by additional hardware. Furthermore, by designing the selection conditions to correspond to the communication parameters of the currently serving satellite, the triggering of satellite handover is based entirely on the actual communication status of the satellite, ensuring the necessity and accuracy of handover initiation. When selecting target satellites, the aim is always to solve the deficiencies in the communication parameters of the currently serving satellite, objectively matching the terminal service's requirements for key parameters, avoiding subjective weighting bias, and significantly improving the objectivity and service adaptability of handover decisions. Thus, without increasing the hardware burden, a more objective, accurate, and service-compatible satellite handover is achieved.

[0025] To address the problems of the prior art, embodiments of this application provide a satellite handover method, apparatus, device, computer storage medium, and computer program product. The satellite handover method provided in this application embodiment will be described first below.

[0026] Figure 1 A flowchart illustrating a satellite handover method according to an embodiment of this application is shown. Figure 1 As shown, the method includes the following steps: S101, if the communication parameters of the currently serving satellite meet the first handover condition, proceed with steps S102-S105.

[0027] It should be noted that, as an example, in a satellite communication scenario, the communication link between the current serving satellite and the ground terminal is affected by factors such as satellite dynamics, bandwidth resource consumption, and signal propagation loss, causing communication quality to change dynamically over time. Continuing to use a serving satellite whose communication parameters no longer meet business requirements can lead to communication interruptions, increased data transmission latency, and insufficient bandwidth. Therefore, it is necessary to first determine whether the communication parameters of the current serving satellite meet the first handover condition. This serves as a prerequisite for initiating the handover process, ensuring that handover decisions are triggered only when necessary, avoiding ineffective handovers that consume terminal computing power and communication resources, and simultaneously guaranteeing the stability and service adaptability of the communication link.

[0028] As an example, a currently serving satellite can refer to a satellite that currently establishes a communication connection with a ground terminal and provides communication services such as data transmission and signal relay to the terminal. It is the core carrier of the terminal's current communication link.

[0029] As an example, communication parameters can refer to key indicators that reflect the communication status and service capabilities between the satellite and the terminal, including but not limited to remaining service time (the remaining duration for which the satellite can continuously provide services to the terminal), remaining bandwidth resources (the idle bandwidth that the satellite can allocate to the terminal), and signal quality (the quality of the communication signal determined by the satellite's transmit power, antenna gain, and the distance between the terminal and the satellite).

[0030] As an example, the first handover condition can refer to the judgment criteria that are set in advance according to the terminal service requirements and trigger the handover process. It corresponds to specific communication parameters, such as the remaining service time being less than a second preset threshold, the remaining bandwidth resources being less than a first preset threshold, the signal quality being less than a fourth preset threshold, etc. When the corresponding communication parameters of the currently serving satellite reach the standard, the subsequent handover steps are triggered.

[0031] Specifically, as an example, the ground terminal periodically reads the communication parameters sent by the currently serving satellite, including the remaining service time, remaining bandwidth resources, satellite transmission power, antenna gain, and its distance from the satellite (calculated by the terminal positioning module and satellite coordinates). The read communication parameters are compared with the preset first switching conditions. If the communication parameters meet the first switching conditions, subsequent steps S102 to S105 can be executed. If not, communication with the currently serving satellite is maintained, and the judgment process is repeated in the next cycle.

[0032] S102, send the current status information of the ground terminal to the ground station.

[0033] It should be noted that, as an example, the ground station, as the core control node of the satellite communication system, possesses global satellite status awareness and calculation capabilities. It can acquire real-time ephemeris data (including coordinates, angular velocity, orbital radius, etc.) of all satellites and calculate the coverage area of ​​each satellite. In contrast, the ground terminal can only obtain local information about the currently serving satellites and cannot independently determine whether other satellites can cover it or whether they have the capability to provide services. Therefore, the ground terminal needs to send its current status information to the ground station, providing crucial terminal-side data for the ground station to screen suitable candidate satellites, ensuring that the subsequently selected candidate satellites are compatible with the terminal's actual position and motion state.

[0034] As an example, a ground terminal can refer to a terminal device that has satellite communication capabilities, can establish a communication connection with a satellite, and can realize data transmission and reception and business data processing. It is the user-side carrier of the satellite communication link, such as satellite phones, vehicle-mounted satellite communication terminals, and Internet of Things satellite terminals.

[0035] As an example, a ground station can refer to a facility deployed on the ground that has the ability to interact with satellites, process data, and manage global satellites. It is responsible for receiving ephemeris data reported by satellites, calculating satellite coverage, screening candidate satellite sets, and interacting with ground terminals. It is the core control hub connecting satellites and terminals.

[0036] As an example, current status information can refer to data reflecting the current location and movement characteristics of a ground terminal, including but not limited to the terminal's current coordinates (obtained through the terminal's built-in positioning module, such as GPS or BeiDou positioning module), movement speed (real-time rate of the terminal's movement), and movement direction (real-time azimuth angle of the terminal's movement). This information is the key basis for the ground station to determine whether the satellite can cover the terminal.

[0037] Specifically, as an example, the ground terminal encrypts its current coordinates, speed, and direction of movement through a communication link established with the current serving satellite (to prevent data theft or tampering); the encrypted status information is then forwarded to the ground station by the current serving satellite to ensure that the ground station can accurately obtain the terminal's real-time status data.

[0038] S103, receive response information from the ground station; wherein, the response information includes a first candidate satellite set and the communication parameters of each candidate satellite; the first candidate satellite set is determined by the ground station calculating the coverage range of each satellite based on the communication parameters reported by multiple satellites, and selecting satellites whose coverage range meets preset conditions from other satellites for the currently serving satellites.

[0039] It should be noted that, as an example, the ground station has already obtained the global satellite ephemeris data and coverage information, and has received the terminal's current status information through step S102, thus possessing the conditions to filter candidate satellites that can cover the terminal and are compatible with the currently serving satellites. After the ground station calculates and determines the first candidate satellite set and the communication parameters of each candidate satellite, it needs to feed this information back to the ground terminal so that the terminal can obtain the basic data for filtering target satellites. If this response information is missing, the terminal cannot know which satellites can be used for switching, nor can it obtain the communication parameters of the candidate satellites, and the subsequent steps of filtering target satellites will not be able to be executed.

[0040] As an example, response information can refer to the data returned by the ground station in response to the status information reported by the terminal. The core content is the first candidate satellite set and the communication parameters of each candidate satellite. It is the basis for the handover decision provided by the ground station to the terminal, ensuring that the terminal can make subsequent local decisions based on the global screening results.

[0041] As an example, the first candidate satellite set can refer to the set of satellites selected by the ground station from other satellites besides the currently serving satellites, whose coverage meets the preset conditions. The satellites in this set all have the basic capability to cover the ground terminal and provide communication services to the terminal, and are the candidate range of target satellites for the terminal to select in the future.

[0042] As an example, the preset conditions can refer to the criteria used by the ground station to select the first set of candidate satellites. Specifically, this could mean that the satellite's coverage area includes the ground terminal's current location, and that the satellite has overlapping coverage time with the currently serving satellite, and that the overlapping coverage time is greater than the estimated handover time. The overlapping coverage time ensures that the terminal can complete the handover to the candidate satellite before the currently serving satellite fails, thus avoiding communication interruption.

[0043] Specifically, as an example, after receiving the status information relayed by the terminal via the currently serving satellite, the ground station decrypts and extracts the terminal's current coordinates; combining this with the stored ephemeris data of each satellite (including satellite coordinates, angular velocity, orbital radius, minimum accessible elevation angle, etc.), it calculates the coverage area of ​​each satellite; from the satellites other than the currently serving satellite, it selects satellites whose coverage area includes the terminal's current coordinates and whose overlap coverage time with the currently serving satellite is greater than the estimated handover time, forming a first candidate satellite set; simultaneously, it collects the communication parameters of each satellite in the first candidate satellite set (including remaining service time, remaining bandwidth resources, transmit power, antenna gain, etc.); it integrates the first candidate satellite set and the communication parameters of each candidate satellite into response information, which is relayed to the ground terminal via the currently serving satellite; the terminal receives and parses this response information, and stores the first candidate satellite set and the corresponding communication parameters.

[0044] S104, Based on the communication parameters of each candidate satellite, select target satellites that meet the selection criteria from the first candidate satellite set; wherein, the first switching condition and the selection condition correspond to the communication parameters of the currently serving satellite.

[0045] It should be noted that, as an example, the first candidate satellite set only ensures that the satellites in the set have the basic capability to cover the terminal. However, the communication parameters of each candidate satellite (such as remaining service time, remaining bandwidth resources, and signal quality) differ, and the reasons for the terminal's current handover trigger (i.e., the communication parameter problem corresponding to the first handover condition) are different, resulting in different requirements for the target satellite. For example, when handover is triggered due to insufficient remaining bandwidth of the currently serving satellite, candidate satellites with high remaining bandwidth resources should be prioritized; when handover is triggered due to poor signal quality, candidate satellites with excellent signal quality should be prioritized. Therefore, based on the communication parameters of each candidate satellite and the screening conditions corresponding to the first handover condition, target satellites need to be selected from the first candidate satellite set to ensure that the target satellites can accurately solve the communication problems of the currently serving satellite and adapt to the terminal's service requirements.

[0046] As an example, the filtering criteria can refer to the judgment criteria for selecting a target satellite from the first candidate satellite set according to the first switching conditions, which correspond to the first switching conditions and the communication parameters of the currently serving satellite.

[0047] As an example, the target satellite can refer to the satellite selected from the first candidate satellite set that meets the selection criteria and can best adapt to the current service needs of the terminal. It is the final target to which the terminal plans to switch, and its communication parameters can solve the communication problems of the current service satellite, ensuring the stability and service quality of the communication link after the switch.

[0048] As one implementation of S104, the communication parameters include remaining bandwidth resources, the first switching condition includes remaining bandwidth resources being less than a first preset threshold, and S104 further includes the following steps: From the first set of candidate satellites, select the candidate satellite with the highest remaining bandwidth resources as the target satellite.

[0049] It should be noted that, as an example, when the remaining bandwidth resources of the currently serving satellite are less than a first preset threshold, it means that the currently serving satellite can no longer meet the terminal's bandwidth requirements. Continued use will lead to problems such as decreased data transmission rates, service lag, or even transmission interruption. The core objective of triggering a handover at this time is to obtain more sufficient bandwidth resources to ensure normal service operation. Although the first set of candidate satellites has been screened by ground stations and possesses the basic capability to cover the terminal, the remaining bandwidth resources of each satellite differ. Selecting the satellite with the highest remaining bandwidth resources as the target satellite can maximize the satisfaction of the terminal's bandwidth requirements, avoid communication quality problems caused by insufficient bandwidth after the handover, ensure that the handover decision is highly compatible with the triggering reason of "solving insufficient bandwidth," and guarantee the continuous and stable operation of terminal services (such as high-definition data transmission, multi-task concurrent communication, etc.).

[0050] As an example, remaining bandwidth resources refer to the bandwidth capacity of a candidate satellite that is currently unused and can be allocated to ground terminals for data transmission. It is a key indicator for measuring the satellite's ability to provide data transmission services to terminals. The higher the remaining bandwidth resources, the higher the terminal data transmission rate that the satellite can support and the richer the types of services it can carry.

[0051] As an example, the first preset threshold can refer to a threshold set according to the minimum bandwidth requirement of the terminal service. It is the standard for judging whether the remaining bandwidth resources of the current service satellite meet the service requirements. When the remaining bandwidth resources of the current service satellite are lower than the threshold, it is determined that the current bandwidth can no longer support the service, and the switching process based on the remaining bandwidth resources is triggered.

[0052] Specifically, as an example, the ground terminal extracts the remaining bandwidth resource data of each candidate satellite in the first candidate satellite set from the response information received in step S103; sorts the remaining bandwidth resource data of all candidate satellites by value, and determines the candidate satellite with the highest remaining bandwidth resource value; marks the candidate satellite with the highest remaining bandwidth resource value as the target satellite, thus completing the target satellite selection process based on remaining bandwidth resources. If multiple candidate satellites have the same and highest remaining bandwidth resource value, a secondary selection can be performed by combining other communication parameters of the candidate satellites (such as remaining service time) to ensure that the final selected target satellite has the best overall performance.

[0053] The satellite handover method of this application embodiment, when the remaining bandwidth resources of the currently serving satellite are less than a first preset threshold, can directly match the terminal with the satellite with the optimal bandwidth capability by "selecting the candidate satellite with the highest remaining bandwidth resources". This quickly improves problems such as communication lag and data transmission delay caused by insufficient bandwidth, and is especially suitable for bandwidth-sensitive services. Using "highest remaining bandwidth resources" as the target satellite selection criterion eliminates the need for complex multi-parameter calculations and weighting, significantly reducing the computing power consumption of the terminal selection process, shortening the handover decision time, ensuring rapid handover when bandwidth is urgently insufficient, and reducing communication interruption time.

[0054] As another implementation of S104, the communication parameters include the remaining service time, the first handover condition includes the remaining service time being less than a second preset threshold, and S104 also includes the following steps: From the first set of candidate satellites, select the candidate satellite with the longest remaining service time as the target satellite.

[0055] It should be noted that, as an example, when the remaining service time of the currently serving satellite is less than the second preset threshold, it indicates that the currently serving satellite is about to leave the terminal's coverage area due to orbital motion, or will soon be unable to meet the terminal's continuous communication needs. If a switch is not initiated in time, subsequent communication link interruptions are highly likely. The core objective of triggering a switch at this time is to obtain a longer continuous service duration, providing stable communication support for terminal services (such as long-cycle data acquisition, continuous video transmission, etc.), and avoiding frequent switching that could disrupt service continuity. Although the first set of candidate satellites has been screened by ground stations to ensure that all can cover the terminal and have effective overlap with the currently serving satellite's coverage time, the remaining service times of each candidate satellite differ. Selecting the satellite with the longest remaining service time as the target satellite can maximize the stable communication cycle between the terminal and the satellite, reducing the probability of triggering another switch in a short period, thus ensuring continuous service operation and reducing the consumption of computing and communication resources by the terminal due to frequent switching.

[0056] As an example, the remaining service time can refer to the duration from the current moment when a candidate satellite can continuously cover a ground terminal and provide it with effective communication services. This duration is determined by satellite orbital parameters (such as angular velocity and orbital radius), terminal location, and minimum elevation angle at which the satellite can be accessed. It is a key indicator for measuring the continuity of satellite services to terminals.

[0057] As an example, the second preset threshold can refer to a time threshold set according to the minimum requirements of terminal services for communication continuity. It is a standard for judging whether the remaining service time of the current service satellite is sufficient to support subsequent services. When the remaining service time of the current service satellite is lower than the threshold, it is determined that it is necessary to switch to a satellite with more sufficient service time.

[0058] Specifically, as an example, the ground terminal extracts the remaining service time data of each candidate satellite in the first candidate satellite set from the response information received in step S103 (this data is calculated by the ground station combining satellite ephemeris data and terminal status information, and is sent along with the response information); sorts the remaining service time data of all candidate satellites by value, and determines the candidate satellite with the longest remaining service time value; marks the candidate satellite with the longest remaining service time as the target satellite, completing the target satellite selection process based on remaining service time. If multiple candidate satellites have the same and the longest remaining service time values, a secondary selection can be performed by combining other communication parameters such as the remaining bandwidth resources or signal quality of the candidate satellites to ensure that the final selected target satellite comprehensively meets the terminal's service requirements.

[0059] The satellite handover method in this application selects the "candidate satellite with the longest remaining service time" when the remaining service time of the currently serving satellite is less than a second preset threshold. This maximizes the duration of stable communication for the terminal, allowing sufficient time for the terminal to prepare for the next handover and effectively avoiding sudden communication interruptions caused by the exhaustion of satellite service time. It is particularly suitable for services with high requirements for communication continuity. Using the "longest remaining service time" as the selection criterion eliminates the need for complex calculations; the terminal can directly filter candidates based on their remaining service time data, reducing the computational and time costs of the decision-making process and ensuring rapid execution of the handover operation.

[0060] As another implementation of S104, the communication parameters include the remaining service time, the first handover condition includes the remaining service time being less than a third preset threshold, and S104 also includes the following steps: The communication parameters of each candidate satellite in the first candidate satellite set are weighted and calculated to obtain multiple scores; Select the candidate satellite with the highest score as the target satellite.

[0061] It should be noted that, as an example, when the remaining service time of the currently serving satellite is less than the third preset threshold, it means that the satellite has entered a critical state where it will soon be unable to provide services to the terminal. If the satellite is selected for switching based solely on the remaining service time, the impact of key indicators such as signal quality and remaining bandwidth resources on communication will be ignored. This can easily lead to problems such as unstable signal transmission and insufficient bandwidth after the switch, even though the satellite has some service time, thus failing to guarantee the continuous operation of the terminal's services. By weighting the communication parameters of each satellite in the first candidate satellite set to obtain a score, multiple dimensions such as satellite transmit power, antenna gain, distance between the terminal and the satellite, remaining bandwidth resources, and remaining service time can be transformed into a unified quantitative score through standardized formulas and entropy weighting formulas, achieving an objective evaluation of the comprehensive communication performance of the candidate satellites. Selecting the candidate satellite with the highest score as the target satellite ensures that the switched satellite can adapt to the terminal's service needs in terms of multi-dimensional performance. This solves the problem of insufficient remaining service time of the currently serving satellite, avoids the limitations of single-parameter decision-making, reduces the probability of switching again in a short period, and lowers the consumption of terminal computing power and communication resources.

[0062] As an example, the remaining service time can refer to the duration for which a candidate satellite can continuously cover ground terminals and provide effective communication services from the current moment, and its calculation can be based on the following formula: (1) in, For the current time, For the maximum coverage time of the satellite, This refers to the initial time when the terminal enters the satellite coverage area. This indicator is determined by the satellite orbital parameters, the terminal's location, and the minimum elevation angle at which the satellite can be accessed, and is a core criterion for measuring the continuity of satellite services.

[0063] As an example, the third preset threshold can refer to a time threshold set according to the extreme requirements of terminal communication continuity. It is the standard for determining whether the currently serving satellite has entered a critical service state. When the remaining service time is lower than this threshold, the terminal needs to initiate an emergency handover process and conduct a comprehensive performance evaluation of the candidate satellites.

[0064] As an example, communication parameters can refer to a set of indicators that participate in the weighted calculation and reflect the overall communication capabilities of a satellite, including satellite transmission power, antenna gain, distance between the terminal and the satellite, remaining bandwidth resources, and remaining service time. These parameters determine the satellite's communication service level from dimensions such as signal transmission, service duration, and data transmission capabilities.

[0065] As an example, weighted calculation refers to the process of assigning weights based on the degree of influence of each communication parameter on the terminal's communication quality, and then combining the standardized values ​​of each parameter with the weights through standardization formulas and entropy weight formulas to calculate the comprehensive performance score of the candidate satellite. It is the core method for achieving multi-parameter comprehensive evaluation.

[0066] As an example, a score can refer to a weighted calculation that quantifies the overall communication performance of a candidate satellite. A high score directly corresponds to a high or low overall satellite performance and is a key criterion for selecting target satellites.

[0067] Specifically, as an example, the ground terminal can extract data on the transmit power, antenna gain, distance between the terminal and the satellite, remaining bandwidth resources, and remaining service time of each candidate satellite in the first candidate satellite set from the response information of the ground station.

[0068] Specifically, as an example, for positive metrics such as satellite transmit power, antenna gain, remaining bandwidth resources, and remaining service time (higher values ​​indicate better performance), the standardized values ​​can be calculated using the following formula: (2) in, Let j be the original value of the j-th indicator of the i-th satellite. The j-th indicator is the minimum value among all the original satellite values. The j-th indicator is the maximum value among all the original satellite values. Let j be the standard value of the j-th indicator of the i-th satellite.

[0069] Specifically, as an example, for negative indicators such as the distance between the terminal and the satellite (lower values ​​indicate better performance), the standardized value is calculated using the following formula: (3) The meaning of its variables is consistent with the standardized formula for positive indicators. Through standardization, evaluation bias caused by differences in the dimensions of different parameters can be eliminated.

[0070] Specifically, as an example, the information entropy of each parameter can be calculated using the following formula: (4) Where n is the number of satellites involved in the calculation. Remove during calculation Item, Let be the information entropy of the j-th indicator.

[0071] Specifically, as an example, the difference coefficient can be calculated using the following formula: (5) in, Let j be the information entropy of the j-th index. Let be the difference coefficient of the j-th indicator.

[0072] Specifically, as an example, the weights can be calculated using the following formula: (6) in, The number of indicators involved in the calculation. Let be the difference coefficient of the j-th indicator. Let be the weight of the j-th indicator. The magnitude of the weight reflects the degree of influence of the parameter on the overall performance.

[0073] Specifically, as an example, the overall score can be calculated using the following formula: (7) in, This represents the overall score of the i-th candidate satellite. This represents the total number of communication parameter indicators involved in the weighted calculation. The weight representing the j-th communication parameter indicator. The j-th communication parameter of the i-th candidate satellite is the standardized value after normalization. This process is repeated to complete the score calculation for all satellites in the first candidate satellite set.

[0074] The satellite handover method in this application selects the satellite with the highest score by weighted calculation of the communication parameters of candidate satellites when the remaining service time of the currently serving satellite is less than a third preset threshold. This method comprehensively considers multiple dimensions of parameters such as remaining service time, signal quality, and bandwidth resources, avoiding the problem of poor communication indicators after handover caused by selecting a single parameter, and ensuring optimal overall performance of the handover result in emergency situations. The weighted calculation can assign weights to each communication parameter according to its importance to the current scenario, making the selection result more in line with the needs of emergency handover scenarios. Compared with single parameter selection, it can improve the overall communication experience of the terminal after handover.

[0075] As another implementation of S104, the communication parameters include signal quality, the first switching condition includes signal quality being less than a fourth preset threshold, and S104 also includes the following steps: The communication parameters of each candidate satellite in the first candidate satellite set are weighted and calculated to obtain multiple scores; Select the candidate satellite with the highest score as the target satellite.

[0076] It should be noted that, as an example, when the signal quality of the currently serving satellite is less than the fourth preset threshold, it indicates that the communication signal between the terminal and the currently serving satellite can no longer meet the service's requirements for transmission quality. Continuing to use the satellite will result in problems such as signal interruption, increased data transmission error rate, and increased latency. At this time, if only a single parameter is used to select and switch satellites, it is impossible to comprehensively evaluate the signal transmission capabilities of candidate satellites, which may lead to a situation where the signal quality remains poor even after switching. By calculating a score by weighting the communication parameters of each satellite in the first candidate satellite set, core indicators affecting signal quality, such as satellite transmit power, antenna gain, and the distance between the terminal and the satellite, can be transformed into a unified quantitative score, achieving an objective evaluation of the candidate satellite's signal quality and overall communication performance. Selecting the candidate satellite with the highest score as the target satellite ensures that the switched satellite has the best signal transmission capability, while also taking into account other communication performance indicators. This effectively solves the problem of insufficient signal quality of the currently serving satellite, ensures the stable operation of terminal services (such as real-time voice communication and high-definition data transmission), and reduces the need for secondary switching due to signal problems.

[0077] As an example, signal quality refers to the quality of satellite communication signals received by a terminal. It is determined by factors such as satellite transmission power, antenna gain, and distance between the terminal and the satellite. It is a core indicator for measuring the stability and reliability of the communication link between the satellite and the terminal. The higher the signal quality, the more guaranteed the accuracy and real-time performance of data transmission.

[0078] As an example, the fourth preset threshold can refer to the standard set according to the minimum requirements of the terminal service for signal transmission quality. It is the basis for determining whether the current service satellite signal quality meets the service requirements. When the signal quality is lower than the threshold, the terminal needs to initiate a handover process based on the signal quality.

[0079] Specifically, as an example, the ground terminal extracts communication parameter data such as transmit power, antenna gain, and distance between the terminal and the satellite for each candidate satellite in the first candidate satellite set from the response information of the ground station. The satellite transmit power and antenna gain are used as positive indicators and are standardized using formula (2). The distance between the terminal and the satellite is used as a negative indicator and is standardized using formula (3). Through standardization, the evaluation bias caused by the difference in the dimensions of different parameters is eliminated. Further, the score calculation of all satellites in the first candidate satellite set is completed according to formulas (4)-(7). The ground terminal summarizes the comprehensive score of all candidate satellites, sorts the scores by numerical value, and determines the candidate satellite with the highest score. If there are multiple candidate satellites with the same score and all of them are the highest, the signal quality-related parameters of these satellites (such as satellite transmit power and antenna gain) are further compared, and the satellite with higher transmit power and antenna gain values ​​is selected first. The candidate satellite with the highest score is finally determined as the target satellite, and the satellite screening process based on signal quality is completed.

[0080] The satellite handover method of this application, when the signal quality of the currently serving satellite is less than a fourth preset threshold, selects the satellite with the highest score by weighted calculation of the communication parameters of candidate satellites. This comprehensively considers multiple factors affecting signal quality, ensuring optimal satellite signal quality after handover and effectively solving problems such as high communication error rate and call noise caused by poor signal. By converting multiple parameters affecting signal quality into intuitive scores through weighted calculation, the one-sidedness of judging signal quality by a single parameter can be avoided, making the selection of target satellites more scientific and comprehensive. This ensures an effective improvement in the signal experience of the terminal after handover and is suitable for services sensitive to signal quality.

[0081] S105: When the target satellite is different from the currently serving satellite, switch the currently serving satellite to the target satellite.

[0082] As an example, the target satellite selected in step S104 may be the same as the currently serving satellite (for example, although the communication parameters of the currently serving satellite trigger the first handover condition, the communication parameters of all candidate satellites are inferior to those of the currently serving satellite). If a handover is performed in this case, it will lead to communication link interruption or service quality degradation, which does not meet the original purpose of the handover. Therefore, it is necessary to first determine whether the target satellite is different from the currently serving satellite, and only perform the handover when they are different to ensure that the handover behavior can effectively improve communication quality; if they are the same, the current connection is maintained to avoid communication fluctuations and resource consumption caused by invalid handover.

[0083] As an example, switching from the current service satellite to the target satellite can refer to the process by which the ground terminal disconnects from the current service satellite, establishes a communication connection with the target satellite, and migrates the transmission link of business data from the current service satellite to the target satellite. This is a core operation for optimizing communication links and ensuring continuous service transmission.

[0084] Specifically, as an example, the ground terminal compares the identification information (such as satellite ID) of the target satellite determined in step S104 with the identification information of the currently serving satellite. If they are different, the terminal sends a disconnection request to the currently serving satellite and a connection request to the target satellite. After the target satellite responds to the connection request and establishes a communication link, the terminal switches the transmission link of the service data to the target satellite and completes the switching process. If they are the same, the terminal maintains the communication connection with the currently serving satellite, does not perform the switching operation, and re-executes the judgment process of step S101 in the next cycle.

[0085] In the satellite handover method of this application embodiment, the ground station calculates the coverage area and determines the first candidate satellite set based on the communication parameters reported by each satellite. The communication parameters of the candidate satellites are sent by the ground station. The collaborative architecture between the ground station and the ground terminal enables the ground terminal to obtain the required data without the need for additional hardware, avoiding the increased cost and power consumption caused by additional hardware. Furthermore, by designing the selection conditions to correspond to the communication parameters of the currently serving satellite, the triggering of satellite handover is based entirely on the actual communication status of the satellite, ensuring the necessity and accuracy of handover initiation. When selecting target satellites, the aim is always to solve the deficiencies in the communication parameters of the currently serving satellite, objectively matching the terminal service's requirements for key parameters, avoiding subjective weighting bias, and significantly improving the objectivity and service adaptability of handover decisions. Thus, without increasing the hardware burden, a more objective, accurate, and service-compatible satellite handover is achieved.

[0086] As another implementation of this application, in order to further ensure the rationality of the handover decision and the continuity of communication, such as Figure 2 As shown, prior to S104, the method may further include the following steps: It should be noted that, as an example, the first set of candidate satellites selected by the ground station only meets the basic condition of "covering the terminal and having effective overlap in coverage time with the currently serving satellites," without considering the differentiated requirements of different terminal services for satellite communication parameters. For example, high-definition video transmission services have high requirements for remaining bandwidth resources, while long-cycle data acquisition services are more sensitive to remaining service time. If target satellites are directly selected from the first set of candidate satellites, performance evaluation of a large number of satellites that only meet the basic conditions but do not meet the service requirements would be necessary, increasing the terminal's computing power consumption and decision-making latency.

[0087] It should be noted that, as an example, by configuring a second handover condition that matches business requirements, a second candidate satellite set is obtained by secondary screening of the first candidate satellite set. Satellites that do not meet the business parameter requirements can be eliminated first, retaining only candidate satellites that meet the business requirements. Selecting target satellites from the second candidate satellite set when it is not empty reduces the computational load in subsequent decision-making processes, improves handover decision efficiency, and ensures that the finally selected target satellites meet basic coverage conditions while adapting to the current business characteristics of the terminal. This avoids communication quality failures after handover due to mismatches between satellite parameters and business requirements.

[0088] S201, based on the current service requirements of satellite communication, configure corresponding second switching conditions for multiple satellite communication parameters.

[0089] As an example, service requirements can refer to the specific requirements of a terminal for satellite communication capabilities when conducting communication services through the currently serving satellite. The requirements vary for different types of services. For example, real-time voice services have high requirements for signal quality, large file transfer services have high requirements for remaining bandwidth resources, and continuous communication services of mobile terminals have high requirements for remaining service time.

[0090] As an example, the second switching condition can refer to the screening criteria set for each satellite communication parameter according to the terminal service requirements. It is the basis for determining whether the candidate satellite is suitable for the terminal service. It corresponds one-to-one with the satellite communication parameters and needs to be formulated in conjunction with the parameter requirement threshold of the service.

[0091] Specifically, as an example, the ground terminal identifies the type of communication service currently being conducted via the serving satellite, clarifies the specific requirements of this service for satellite communication parameters such as remaining bandwidth resources, remaining service time, and signal quality, and determines the minimum or optimal range that each parameter must meet. For each satellite communication parameter that needs to be included in the screening, a corresponding second switching condition is set according to the service requirements. For example, if the terminal is conducting high-definition video transmission services, the requirement for remaining bandwidth resources is no less than 5Mbps, then the second switching condition configured for remaining bandwidth resources is "remaining bandwidth resources ≥ 5Mbps"; if it is conducting long-cycle data acquisition services, the requirement for remaining service time is no less than 2 hours, then the second switching condition configured for remaining service time is "remaining service time ≥ 2 hours". The configured second switching conditions are stored locally on the terminal as the basis for subsequent screening of candidate satellites.

[0092] S202, based on the second switching condition, the candidate satellites in the first candidate satellite set are screened to obtain the second candidate satellite set.

[0093] As an example, the second candidate satellite set can refer to the set of satellites that meet all the second handover conditions after comparing the satellites in the first candidate satellite set with the second handover conditions. The satellites in this set meet both the basic coverage requirements and the current service needs of the terminal.

[0094] Specifically, as an example, the ground terminal retrieves the second handover conditions configured in step S201 from its local storage, and simultaneously extracts the communication parameter data of each candidate satellite in the first candidate satellite set. The communication parameters of each candidate satellite are compared one by one with the corresponding second handover conditions to determine whether the satellite meets all the second handover conditions. For example, it checks whether the remaining bandwidth resources of the candidate satellites reach the threshold set by the second handover conditions, and whether the remaining service time meets the standards corresponding to the service requirements. All candidate satellites that meet the second handover conditions are selected and integrated into a second candidate satellite set; if no satellite in the first candidate satellite set meets the second handover conditions, the second candidate satellite set is empty. The second candidate satellite set and the communication parameters of each satellite in it are stored locally on the terminal to prepare for subsequent target satellite selection.

[0095] Based on the communication parameters of each candidate satellite, target satellites that meet the screening criteria are selected from the first candidate satellite set, including: S203, if the second candidate satellite set is not empty, select target satellites that meet the selection criteria from the second candidate satellite set based on the communication parameters of each candidate satellite.

[0096] Specifically, as an example, the ground terminal first determines whether the second candidate satellite set is empty by counting the number of satellites in the second candidate satellite set. If the second candidate satellite set is not empty, the communication parameters of each satellite in the second candidate satellite set are extracted, and target satellites are selected according to the filtering conditions corresponding to the current first handover condition: if the filtering condition is to select the satellite with the highest remaining bandwidth resources, the satellites in the second candidate satellite set are sorted by their remaining bandwidth resources, and the satellite with the highest value is selected; if the filtering condition is to select the satellite with the highest score through weighted calculation, the communication parameters of the satellites in the second candidate satellite set are standardized, and entropy weighted calculation is performed to obtain the scores of each satellite, and then the satellite with the highest score is selected. The selected satellites are marked as target satellites, completing the target satellite selection process from the second candidate satellite set.

[0097] The satellite handover method in this application, by configuring a second handover condition based on service requirements, can set differentiated satellite parameter screening criteria for different services, making the satellites in the second candidate satellite set more suitable for the current service's communication quality requirements, thus solving the problem that general screening cannot adapt to diverse services. The second handover condition is used to initially screen the first candidate satellite set, eliminating satellites that do not meet the current service requirements, narrowing the scope of subsequent target satellite screening, reducing the computing power consumed by the terminal when calculating and comparing candidate satellite communication parameters, and improving the efficiency of handover decisions, especially suitable for ground terminals with limited computing power. By explicitly selecting target satellites only from the second candidate satellite set when it is not empty, it avoids handover errors caused by forced screening when no satellites meet the service requirements are available, further ensuring the rationality of the handover decision and communication continuity.

[0098] As another implementation of this application, in order to adapt to the usage requirements of low-computing-power terminals, such as Figure 3 As shown, prior to S101, the method may further include the following steps: It should be noted that, as an example, a satellite orbits the Earth, and its coverage area for ground terminals changes dynamically with its orbital position. The duration for which a candidate satellite can provide service to the terminal is one of the key indicators determining the handover decision. The remaining service time directly reflects the period during which a candidate satellite can continuously provide communication services to the terminal. If this parameter cannot be accurately calculated, the terminal may select a satellite with too short a service time during the handover, causing another handover to be triggered in a short period of time, increasing the instability of the communication link and the terminal's computing power consumption.

[0099] It should be noted that, as an example, by obtaining the initial time step by step, calculating the maximum coverage time, and then combining it with the current time to deduce the remaining service time, the dynamic changes in satellite orbits and the positional relationship between the terminal and the satellite can be transformed into quantifiable time indicators. This calculation process relies on the global orbit calculation capabilities of the ground station and the local data processing capabilities of the terminal to achieve an accurate assessment of the service continuity of candidate satellites. This provides objective and reliable data support for subsequent handover decisions based on the remaining service time, ensuring that the switched satellite can meet the terminal's communication continuity requirements.

[0100] S301, obtain the initial time when the ground terminal enters the coverage area of ​​the candidate satellite; wherein, the initial time is calculated by the ground station and transmitted through the currently serving satellite.

[0101] As an example, the initial time can refer to the specific moment when the ground terminal enters the coverage area of ​​the candidate satellite. It is the starting point for measuring the duration of service provided by the candidate satellite to the terminal. Its value is calculated by the ground station in combination with the satellite orbit parameters and the terminal's position and motion data.

[0102] Specifically, as an example, the ground station continuously receives ephemeris data reported by each candidate satellite and calculates the real-time coverage area of ​​each candidate satellite using the ephemeris data. The ground station receives data such as the location, speed, and direction of movement of the ground terminal relayed by the currently serving satellite. It matches and analyzes this terminal data with the coverage areas of the candidate satellites to calculate the specific time when the terminal enters the coverage area of ​​each candidate satellite, i.e., the initial time. The ground station sends the calculated initial time to the currently serving satellite, which then relays this data to the corresponding ground terminal. The ground terminal receives and stores the initial time data relayed by the currently serving satellite, completing this data acquisition step.

[0103] S302, obtain the orbital parameters of the candidate satellite and calculate the maximum coverage time of the candidate satellite for the ground terminal.

[0104] As an example, orbital parameters can refer to the core data describing the orbital motion characteristics of candidate satellites, including the satellite's angular velocity, orbital radius, trajectory plane equation, minimum accessible elevation angle, etc. These parameters are the basis for calculating the satellite's coverage range and coverage time.

[0105] As an example, the maximum coverage time can refer to the total time from when a ground terminal enters the coverage area of ​​a candidate satellite to when it leaves that coverage area. It is the longest period during which a candidate satellite can provide services to the terminal, and its value is determined by the relationship between the satellite orbital parameters and the terminal's position.

[0106] Specifically, as an example, the ground terminal first obtains the candidate satellite orbital parameters transmitted by the ground station through the currently serving satellite, including the satellite angular velocity ω, orbital radius, trajectory plane equation, etc. The satellite angular velocity ω can be calculated using the following formula: (8) Where G is the gravitational constant, M is the mass of the Earth, and r is the orbital radius of the candidate satellite. This formula is derived from the balance relationship between the law of universal gravitation and the centripetal force of the satellite's circular motion, and is used to accurately characterize the angular velocity of the satellite orbiting the Earth.

[0107] Specifically, as an example, the shortest distance d from the terminal to the candidate satellite trajectory plane is calculated. This distance is obtained by using the terminal coordinates and the candidate satellite trajectory plane equation, which is generated by the ground station by fitting three sampling points from the periodically acquired satellite coordinates.

[0108] Specifically, as an example, the formula for calculating the maximum satellite coverage time is: (9) Where r is the satellite orbital radius, Let ω be the satellite's angular velocity, and d be the shortest distance from the terminal to the satellite's trajectory plane. This formula is derived geometrically, first calculating the central angle corresponding to the terminal being within the satellite's coverage area as the satellite orbits the Earth. Combined with satellite angular velocity This yields the time span corresponding to the central angle, i.e., the maximum coverage time. .

[0109] S303. Based on the initial time and maximum coverage time, combined with the current time, the remaining service time of the candidate satellite is calculated.

[0110] Specifically, as an example, after obtaining the initial time, maximum coverage time, and current time, the terminal calculates the remaining service time of the candidate satellite according to formula (1). After calculating the remaining service time, the terminal stores it and periodically updates the value according to the change of the current time to ensure that the remaining service time is always consistent with the actual situation, providing accurate data support for subsequent handover condition judgment (such as the remaining service time being less than the second preset threshold, the third preset threshold, etc.).

[0111] The satellite handover method in this application employs a standardized process: the ground station calculates the initial time and combines it with orbital parameters to calculate the maximum coverage time. Based on this standardized process, the remaining service time is calculated using the initial time, maximum coverage time, and current time. This eliminates errors caused by the terminal calculating coverage area and orbital parameters independently, ensuring a high degree of match between the remaining service time data and the actual satellite operating status and terminal location. This provides reliable data support for subsequent handover decisions based on the remaining service time. The initial time is calculated by the ground station and transmitted via the currently serving satellite, eliminating the need for the terminal to separately calculate satellite coverage area and initial time. The orbital parameters are sent by the ground station, requiring the terminal to perform only subsequent calculations. This significantly reduces the computing power consumed by the terminal during data acquisition and calculation, adapting to the needs of low-computing-power terminals (such as IoT sensor terminals).

[0112] Based on the satellite handover method provided in the above embodiments, this application also provides specific implementation methods of the satellite handover device. Please refer to the following embodiments.

[0113] First see Figure 4 The satellite switching device 40 provided in this application embodiment includes the following modules: The condition judgment module 401 is used to determine whether the communication parameters of the currently serving satellite meet the first handover condition; The information sending module 402 is used to send the current status information of the ground terminal to the ground station; The information receiving module 403 is used to receive response information from the ground station; wherein, the response information includes a first candidate satellite set and the communication parameters of each candidate satellite; the first candidate satellite set is determined by the ground station by calculating the coverage range of each satellite based on the communication parameters reported by multiple satellites, and selecting satellites whose coverage range meets preset conditions from other satellites for the currently serving satellites; The satellite screening module 404 is used to screen target satellites that meet the screening conditions from the first candidate satellite set based on the communication parameters of each candidate satellite; wherein the first switching condition and the screening condition correspond to the communication parameters of the currently serving satellite. In some embodiments, the communication parameters include remaining bandwidth resources, the first switching condition includes remaining bandwidth resources being less than a first preset threshold, and the first satellite screening submodule is used to select the candidate satellite with the highest remaining bandwidth resources from the first candidate satellite set as the target satellite.

[0114] In some embodiments, the communication parameters include remaining service time, the first switching condition includes remaining service time being less than a second preset threshold, and the second satellite screening submodule is used to select the candidate satellite with the longest remaining service time from the first candidate satellite set as the target satellite.

[0115] In some embodiments, the communication parameters include remaining service time, the first handover condition includes remaining service time being less than a third preset threshold, and the satellite screening module 404 further includes: The weighted calculation module is used to perform weighted calculations on the communication parameters of each candidate satellite in the first candidate satellite set to obtain multiple scores; The third satellite screening submodule is used to select the candidate satellite with the highest score as the target satellite.

[0116] In some embodiments, the communication parameters include signal quality, the first switching condition includes signal quality being less than a fourth preset threshold, and the satellite screening module 404 further includes: The scoring calculation module is used to perform weighted calculations on the communication parameters of each candidate satellite in the first candidate satellite set to obtain multiple scores; The fourth satellite screening submodule is used to select the candidate satellite with the highest score as the target satellite.

[0117] The satellite switching module 405 is used to switch the current service satellite to the target satellite when the target satellite is different from the current service satellite.

[0118] In some embodiments, the satellite switching device 40 may further include the following modules: The threshold configuration module is used to configure corresponding second switching conditions for multiple satellite communication parameters based on the service requirements of the current service satellite communication before the satellite screening module selects target satellites that meet the screening conditions from the first candidate satellite set based on the communication parameters of each candidate satellite. The secondary screening module is used to screen the candidate satellites in the first candidate satellite set based on the second switching condition to obtain the second candidate satellite set; The satellite screening module is used to select target satellites that meet the screening criteria from the second candidate satellite set based on the communication parameters of each candidate satellite, provided that the second candidate satellite set is not empty.

[0119] In some embodiments, the satellite switching device 40 may further include the following modules: Before the condition judgment module determines that the satellite communication parameters of the currently serving satellite meet the first handover condition, for each candidate satellite in the first candidate satellite set: The initial time acquisition module is used to acquire the initial time when the ground terminal enters the coverage area of ​​the candidate satellite; the initial time is calculated by the ground station and transmitted through the currently serving satellite. The coverage time calculation module is used to obtain the orbital parameters of candidate satellites and calculate the maximum coverage time of candidate satellites for ground terminals. The remaining time calculation module is used to calculate the remaining service time of candidate satellites based on the initial time and maximum coverage time, combined with the current time.

[0120] Figure 5 A schematic diagram of the hardware structure of the electronic device provided in an embodiment of this application is shown.

[0121] The electronic device may include a processor 501 and a memory 502 storing computer program instructions.

[0122] Specifically, the processor 501 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0123] Memory 502 may include mass storage for data or instructions. For example, and not limitingly, memory 502 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 502 may include removable or non-removable (or fixed) media. Where appropriate, memory 502 may be internal or external to the integrated gateway disaster recovery device. In a particular embodiment, memory 502 is non-volatile solid-state memory.

[0124] Memory may include read-only memory (ROM), random access memory (RAM), disk storage media devices, optical storage media devices, flash memory devices, and electrical, optical, or other physical / tangible memory storage devices. Therefore, typically, memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the methods according to one aspect of this disclosure.

[0125] The processor 501 implements any of the satellite handover methods described in the above embodiments by reading and executing computer program instructions stored in the memory 502.

[0126] In one example, the electronic device may also include a communication interface 503 and a bus 510. Wherein, as... Figure 5 As shown, the processor 501, memory 502, and communication interface 503 are connected through bus 510 and complete communication with each other.

[0127] The communication interface 503 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0128] Bus 510 includes hardware, software, or both, that couples components of an electronic device together. For example, and not limitingly, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 510 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, this application contemplates any suitable bus or interconnect.

[0129] Furthermore, in conjunction with the satellite handover methods described in the above embodiments, this application embodiment can provide a computer storage medium for implementation. This computer storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement any of the satellite handover methods described in the above embodiments.

[0130] This application also provides a computer program product, including a computer program that, when executed by a processor, implements any of the satellite handover methods described in the above embodiments.

[0131] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0132] The functional blocks shown in the above block diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0133] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0134] The aspects of this disclosure have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by special-purpose hardware performing the specified functions or actions, or can be implemented by a combination of special-purpose hardware and computer instructions.

[0135] The above are merely specific embodiments of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A satellite handover method, characterized in that, The method is executed by a ground terminal and includes: If the communication parameters of the currently serving satellite meet the first handover condition, perform the following steps: Send the current status information of the ground terminal to the ground station; The system receives response information from the ground station; wherein the response information includes a first candidate satellite set and communication parameters of each candidate satellite; the first candidate satellite set is determined by the ground station based on the communication parameters reported by multiple satellites to calculate the coverage range of each satellite, and for the currently serving satellite, selecting satellites whose coverage range meets preset conditions from other satellites. Based on the communication parameters of each candidate satellite, target satellites that meet the screening criteria are selected from the first candidate satellite set; wherein, the first switching condition and the screening condition correspond to the communication parameters of the currently serving satellite. If the target satellite is different from the currently serving satellite, the currently serving satellite will be switched to the target satellite.

2. The method according to claim 1, characterized in that, Before selecting target satellites that meet the selection criteria from the first candidate satellite set based on the communication parameters of each candidate satellite, the method further includes: Based on the current service requirements of satellite communication, configure corresponding second switching conditions for multiple satellite communication parameters; Based on the second switching condition, candidate satellites in the first candidate satellite set are filtered to obtain a second candidate satellite set; The step of selecting target satellites that meet the selection criteria from the first candidate satellite set based on the communication parameters of each candidate satellite includes: If the second candidate satellite set is not empty, target satellites that meet the screening criteria are selected from the second candidate satellite set based on the communication parameters of each candidate satellite.

3. The method according to claim 1, characterized in that, The communication parameters include remaining bandwidth resources, and the first switching condition includes the remaining bandwidth resources being less than a first preset threshold. The step of selecting target satellites that meet the selection conditions from the first candidate satellite set based on the communication parameters of each candidate satellite includes: From the first set of candidate satellites, select the candidate satellite with the highest remaining bandwidth resources as the target satellite.

4. The method according to claim 1, characterized in that, The communication parameters include remaining service time, and the first switching condition includes the remaining service time being less than a second preset threshold. The step of selecting target satellites that meet the selection criteria from the first candidate satellite set based on the communication parameters of each candidate satellite includes: From the first set of candidate satellites, select the candidate satellite with the longest remaining service time as the target satellite.

5. The method according to claim 1, characterized in that, The communication parameters include remaining service time, and the first switching condition includes the remaining service time being less than a third preset threshold. The step of selecting target satellites that meet the selection criteria from the first candidate satellite set based on the communication parameters of each candidate satellite includes: The communication parameters of each candidate satellite in the first candidate satellite set are weighted and calculated to obtain multiple scores; The candidate satellite with the highest score is selected as the target satellite.

6. The method according to any one of claims 4-5, characterized in that, Before the satellite communication parameters of the currently serving satellite meet the first switching condition, for each candidate satellite in the first candidate satellite set, the method further includes: The initial time when the ground terminal enters the coverage area of ​​the candidate satellite is obtained; wherein the initial time is calculated by the ground station and transmitted through the currently serving satellite; Obtain the orbital parameters of the candidate satellites and calculate the maximum coverage time of the candidate satellites for the ground terminal; The remaining service time of the candidate satellite is calculated based on the initial time and the maximum coverage time, combined with the current time.

7. The method according to claim 1, characterized in that, The communication parameters include signal quality, and the first switching condition includes the signal quality being less than a fourth preset threshold. The step of selecting target satellites that meet the selection criteria from the first candidate satellite set based on the communication parameters of each candidate satellite includes: The communication parameters of each candidate satellite in the first candidate satellite set are weighted and calculated to obtain multiple scores; The candidate satellite with the highest score is selected as the target satellite.

8. A satellite switching device, characterized in that, The device includes: The condition judgment module is used to determine whether the communication parameters of the currently serving satellite meet the first handover condition; The information sending module is used to send the current status information of the ground terminal to the ground station; An information receiving module is used to receive response information from the ground station; wherein the response information includes a first candidate satellite set and communication parameters of each candidate satellite; the first candidate satellite set is determined by the ground station by calculating the coverage range of each satellite based on the communication parameters reported by multiple satellites, and selecting satellites whose coverage range meets preset conditions from other satellites for the currently serving satellite; The satellite filtering module is used to filter target satellites that meet the filtering conditions from the first candidate satellite set based on the communication parameters of each candidate satellite; wherein the first switching condition and the filtering condition correspond to the communication parameters of the currently serving satellite. The satellite switching module is used to switch the current service satellite to the target satellite when the target satellite is different from the current service satellite.

9. An electronic device, characterized in that, The device includes: a processor and a memory storing computer program instructions; When the processor executes the computer program instructions, it implements the satellite switching method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer program instructions, which, when executed by a processor, implement the satellite handover method as described in any one of claims 1-7.

11. A computer program product, characterized in that, When the instructions in the computer program product are executed by the processor of the electronic device, the electronic device performs the satellite switching method as described in any one of claims 1-7.

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