Inter-satellite handover method and apparatus, network device, and storage medium

Abstract

The present application relates to an inter-satellite handover method and apparatus, a network device, and a storage medium. The method comprises: determining range parameters of a beam position coverage area of each beam position corresponding to a satellite, wherein the range parameters include the central position and the major-axis length of each beam position coverage area; on the basis of a satellite ephemeris and the central position of each beam position coverage area, determining a first satellite service end time corresponding to the central position of the corresponding beam position coverage area; and on the basis of a result of comparison between the major-axis length of each beam position coverage area and a preset distance threshold, determining a calculation strategy for satellite service end times, and on the basis of the calculation strategy and the first satellite service end time, calculating a satellite service end time for each user in the corresponding beam position coverage area, wherein the satellite service end time is used for performing inter-satellite handover for the user. This method can improve the efficiency of handover for users.

Description

Cross-satellite handover method and device, network device, and storage medium

[0001] This application is based on the Chinese Patent Application No. 2024113627931 entitled "Cross-satellite handover method and device, network device, and storage medium" filed on September 27, 2024, which is incorporated by reference in its entirety into this application. TECHNICAL FIELD

[0002] The present application relates to the field of satellite communication technology, and in particular to a cross-satellite handover method, device, network device, and storage medium. BACKGROUND

[0003] Low-orbit satellites are not stationary relative to the ground but are always in motion, so the duration of low-orbit satellite coverage of user equipment is limited. Therefore, triggering cross-satellite handover based on user location and satellite ephemeris is a typical scenario for handover in a low-orbit satellite communication system. The network device first calculates the end time of the current satellite service for the user, and then, before the end time of the current satellite service for the user, timely triggers the user to switch to a neighboring satellite to ensure the continuity of user traffic.

[0004] In the traditional technology, for the end time of satellite service for each user in the wave position coverage area of each wave position of a satellite, the network device calculates the end time of satellite service for the user in each wave position coverage area based on a pre-configured calculation strategy.

[0005] However, in the traditional technology, the pre-configured calculation strategy for the end time of satellite service has poor flexibility, which in turn results in low efficiency of user switching by the user. SUMMARY

[0006] The embodiments of the present application provide a cross-satellite handover method, device, network device, and storage medium.

[0007] In a first aspect, the present application provides a cross-satellite handover method, which is applied to a network device, and the method comprises:

[0008] determining range parameters of wave position coverage areas of each wave position corresponding to a satellite; the range parameters include a center position and a major axis length of each wave position coverage area;

[0009] determining a first satellite service end time corresponding to the center position of the wave position coverage area based on satellite ephemeris and the center position of the wave position coverage area;

[0010] determine a calculation strategy of the satellite service end time according to a comparison result of a ratio of the long axis length of the wave position coverage area to a preset distance threshold, and calculate the satellite service end time of each user in the wave position coverage area based on the calculation strategy and the first satellite service end time; the satellite service end time is used for cross-satellite switching of the user.

[0011] In some embodiments, the calculation of the satellite service end time of each user in the wave position coverage area based on the calculation strategy and the first satellite service end time comprises:

[0012] if the long axis length of the wave position coverage area is less than or equal to the distance threshold, the first satellite service end time is determined as the satellite service end time of each user in the wave position coverage area;

[0013] if the long axis length of the wave position coverage area is greater than the distance threshold, the satellite service end time of each user in the wave position coverage area in a target time interval is predicted according to the range parameter of the wave position coverage area and the satellite moving speed.

[0014] In some embodiments, the method further comprises:

[0015] determining the latest switching time of each user based on the cross-satellite switching time length and the satellite service end time of each user in the wave position coverage area;

[0016] constructing a first information table, wherein the first information table contains the user identifier of the user in the wave position coverage area and the latest switching time of each user.

[0017] In some embodiments, in the case that a single satellite supports parallel processing of multiple user switching, the method further comprises:

[0018] taking the time when the first user accesses the satellite as the starting time of the first switching period, and constructing a second information table containing multiple switching periods based on the preset period length and the starting time of the first switching period;

[0019] dividing the user identifier corresponding to each user into the user list corresponding to each switching period in the second information table based on the latest switching time of each user contained in the first information table;

[0020] when the starting time of the current switching period is reached, triggering the cross-satellite switching process for each user in the user list corresponding to the current switching period.

[0021] In some embodiments, the dividing the user identifier corresponding to each of the users into the user list corresponding to each of the switching periods in the second information table based on the latest time of user switching of each of the users contained in the first information table comprises:

[0022] traversing the latest time of user switching of each of the users contained in the first information table;

[0023] for each of the users, if the latest time of user switching is within the first target switching period of the second information table, adding the user identifier of the user into the user list corresponding to the first target switching period;

[0024] wherein the first target switching period is any one of the switching periods in the second information table.

[0025] In some embodiments, the method further comprises:

[0026] traversing each of the switching periods contained in the second information table in descending order of period number;

[0027] in a case where the number of user identifiers in the user list corresponding to the second target switching period is greater than the number of processes of user switching supported by the single satellite for parallel processing, sorting the user identifiers of each of the users contained in the second target switching period based on a preset sorting rule to obtain a user sequence;

[0028] retaining the user identifiers of the first target number of users in the user sequence, deleting the user identifiers of subsequent users in the user sequence, and adding the deleted user identifiers into the user list corresponding to the previous switching period of the second target switching period;

[0029] wherein the target number is equal to the number of processes of user switching supported by the single satellite for parallel processing.

[0030] In some embodiments, the preset sorting rule comprises at least one of a sorting rule based on service priority and a sorting rule based on the latest time of user switching.

[0031] In some embodiments, the sorting the user identifiers of each of the users contained in the second target switching period based on the preset sorting rule to obtain a user sequence comprises:

[0032] sorting the user identifiers of each of the users contained in the second target switching period in descending order of service priority;

[0033] if there are users with the same service priority, sorting the users with the same service priority in descending order of the latest time of user switching to obtain a user sequence.

[0034] In some embodiments, the sorting, according to a preset sorting rule, the user identifiers of the users included in the second target switching period, to obtain a user sequence, comprises:

[0035] sorting the user identifiers of the users included in the second target switching period in a sequence from later to earlier according to the latest time of user switching of the users;

[0036] if there are users with the same latest time of user switching, sorting the users with the same service priority in a sequence from high to low according to the service priority, to obtain a user sequence.

[0037] In some embodiments, the method further comprises:

[0038] if there is a first target user whose latest time of user switching is updated in the first information table, deleting the user identifier of the first target user in the second information table, or if there is a second target user that is disconnected from the satellite in the first information table, deleting the user identifier of the second target user in the second information table;

[0039] if the second information table does not contain the user identifier of a third target user who has accessed the satellite, performing the step of dividing the user identifier of each user in the second information table into the user list corresponding to each switching period in the second information table based on the latest time of user switching of each user included in the first information table.

[0040] In some embodiments, the triggering, when the start time of the current switching period is reached, the inter-satellite handover process for each user in the user list corresponding to the current switching period, comprises:

[0041] when the start time of the current switching period is reached, initiating a user switching request to one or more adjacent satellites for each user in the user list corresponding to the current switching period;

[0042] receiving user switching request feedback information of the multiple adjacent satellites, and based on the user switching request feedback information, screening out a target satellite for user switching of the user, and sending a notification message to the user equipment of the user;

[0043] wherein the notification message is used to instruct the user equipment to switch from the current satellite to the target satellite.

[0044] In some embodiments, if the long axis length of the beam coverage area is greater than the distance threshold value, the method further comprises:

[0045] determine a moving speed of a subsatellite point of the satellite on the ground based on the satellite ephemeris and the satellite orbit parameter;

[0046] predict target time intervals in which the satellite service end time corresponding to each of the users in the wave beam coverage area is located based on the moving speed, the range parameter of the wave beam coverage area, and the first satellite service end time.

[0047] In a second aspect, the present application further provides a cross-satellite handover device, which is applied to a network device, and the device comprises:

[0048] a first determining module configured to determine a range parameter of a wave beam coverage area of each wave beam corresponding to a satellite; the range parameter comprises a central position and a major axis length of each wave beam coverage area;

[0049] a second determining module configured to determine a first satellite service end time corresponding to the central position of the wave beam coverage area based on satellite ephemeris and the central position of the wave beam coverage area;

[0050] a calculating module configured to determine a calculation strategy of a satellite service end time based on a comparison result of the major axis length of the wave beam coverage area and a preset distance threshold value, and calculate the satellite service end time of each user in the wave beam coverage area based on the calculation strategy and the first satellite service end time; the satellite service end time is used for cross-satellite handover of the user.

[0051] In a third aspect, the present application further provides a network device, which comprises a memory, a transceiver, and a processor;

[0052] The memory is configured to store a computer program; the transceiver is configured to transceive data under the control of the processor; and the processor is configured to read the computer program in the memory and perform the following operations:

[0053] determine a range parameter of a wave beam coverage area of each wave beam corresponding to a satellite; the range parameter comprises a central position and a major axis length of each wave beam coverage area;

[0054] determine a first satellite service end time corresponding to the central position of the wave beam coverage area based on satellite ephemeris and the central position of the wave beam coverage area;

[0055] determine a calculation strategy of a satellite service end time based on a comparison result of the major axis length of the wave beam coverage area and a preset distance threshold value, and calculate the satellite service end time of each user in the wave beam coverage area based on the calculation strategy and the first satellite service end time; the satellite service end time is used for cross-satellite handover of the user.

[0056] In some embodiments, the processor is specifically configured to:

[0057] If the length of the long axis of the wave position coverage area is less than or equal to a distance threshold value, the first satellite service end time is determined as the satellite service end time of each user in the wave position coverage area;

[0058] If the length of the long axis of the wave position coverage area is greater than the distance threshold value, the satellite service end time of each user in the wave position coverage area in a target time interval is predicted according to the range parameter of the wave position coverage area and the satellite moving speed.

[0059] In some embodiments, the processor is further configured to read the computer program in the memory and perform the following operations:

[0060] Based on the user cross-satellite switching duration and the satellite service end time of each user in the wave position coverage area, the latest switching time of each user is determined;

[0061] A first information table is constructed, which contains the user identifier of the user in the wave position coverage area and the latest switching time of each user.

[0062] In some embodiments, in the case of supporting parallel processing of multiple user switching by a single satellite, the processor is further configured to read the computer program in the memory and perform the following operations:

[0063] The time when the first user accesses the satellite is taken as the starting time of the first switching period, and a second information table containing multiple switching periods is constructed based on the preset period length and the starting time of the first switching period;

[0064] Based on the latest switching time of each user contained in the first information table, the user identifier corresponding to each user is divided into the user list corresponding to each switching period of the second information table;

[0065] When the starting time of the current switching period is reached, the cross-satellite switching process for each user in the user list corresponding to the current switching period is triggered.

[0066] In some embodiments, the processor is specifically configured to:

[0067] Each user switching latest time of each user contained in the first information table is traversed;

[0068] For each user, if the user switching latest time of the user is within the first target switching period of the second information table, the user identifier of the user is added to the user list corresponding to the first target switching period;

[0069] The first target switching period is any one switching period in the second information table.

[0070] In some embodiments, the processor is further configured to read a computer program in the memory and perform the following operations:

[0071] In some embodiments, the processor is further configured to read a computer program in the memory and perform the following operations:

[0072] In some embodiments, the processor is further configured to read a computer program in the memory and perform the following operations:

[0073] In some embodiments, the processor is further configured to read a computer program in the memory and perform the following operations:

[0074] In some embodiments, the target number is equal to the number of processes of user switching supported by the single satellite in parallel processing.

[0075] In some embodiments, the preset sorting rule includes at least one of a sorting rule based on a service priority and a sorting rule based on a latest time of user switching.

[0076] In some embodiments, the processor is specifically configured to:

[0077] In some embodiments, the processor is specifically configured to:

[0078] In some embodiments, the processor is specifically configured to:

[0079] In some embodiments, the processor is specifically configured to:

[0080] In some embodiments, the processor is specifically configured to:

[0081] In some embodiments, the processor is specifically configured to:

[0082] In some embodiments, the processor is further configured to read a computer program in the memory and perform the following operations:

[0083] if there is a first target user in the first information table whose user switching latest time occurs updating, deleting the user identification of the first target user in the second information table, or if there is a second target user in the first information table which is disconnected from the satellite, deleting the user identification of the second target user in the second information table;

[0084] if the second information table does not contain the user identification of a third target user who has accessed the satellite, performing the step of dividing the user identification corresponding to each user in the second information table into the user list corresponding to each switching period based on the user switching latest time of each user contained in the first information table.

[0085] In some embodiments, the processor is specifically used for:

[0086] When the start time of the current switching period is reached, initiating a user switching request to one or more adjacent satellites for each user in the user list corresponding to the current switching period;

[0087] Receiving user switching request feedback information of the plurality of adjacent satellites, and based on the user switching request feedback information, screening out a target satellite for user switching of the user, and sending a notification message to the user equipment of the user;

[0088] The notification message is used to instruct the user equipment to switch from the current satellite to the target satellite.

[0089] In some embodiments, if the long axis length of the wave position coverage area is greater than the distance threshold value, the processor is further used to read the computer program in the memory and perform the following operations:

[0090] Based on the satellite ephemeris and satellite orbit parameters, determining the moving speed of the subsatellite point of the satellite on the ground;

[0091] Based on the moving speed, the range parameter in the wave position coverage area and the first satellite service end time, predicting the target time interval in which the satellite service end time corresponding to each user in the wave position coverage area is located.

[0092] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, the content of the specification can be implemented, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0093] Various other advantages and benefits will become apparent to those of ordinary skill in the art, upon reading the following detailed description of the implementation. The accompanying drawings are included to provide a description of embodiments and are not intended to limit the scope of the application. Moreover, in the drawings, like reference numerals denote like parts throughout the several views. In the drawings:

[0094] FIG. 1 is a diagram of an application environment of a cross-satellite handover method in an embodiment;

[0095] FIG. 2 is a flow diagram of a cross-satellite handover method in an embodiment;

[0096] FIG. 3 is a flow diagram of a step of determining a satellite service end time of a user in different beam coverage areas in an embodiment;

[0097] FIG. 4 is a flow diagram of a step of constructing a first information table in an embodiment;

[0098] FIG. 5 is a flow diagram of a step of triggering a cross-satellite handover of a user based on a second information table in an embodiment;

[0099] FIG. 6 is a flow diagram of a step of updating a second information table in an embodiment;

[0100] FIG. 7 is a flow diagram of a step of processing a user in the second information table that exceeds a number of processes supported by a single satellite in parallel in an embodiment;

[0101] FIG. 8 is a flow diagram of a step of sorting a sequence of users in a second target handover period according to a service priority principle in an embodiment;

[0102] FIG. 9 is a flow diagram of a step of sorting a sequence of users in a second target handover period according to a time priority principle in an embodiment;

[0103] FIG. 10 is a flow diagram of a step of processing a sequence of users in a second information table in an embodiment;

[0104] FIG. 11 is a flow diagram of a step of a cross-satellite handover of a user in an embodiment;

[0105] FIG. 12 is a flow diagram of a step of determining a target time interval in an embodiment;

[0106] FIG. 13 is a diagram of a specific application environment of a step of determining a satellite service end time in an embodiment;

[0107] FIG. 14 is a diagram of a distribution of a latest handover time of UE1 to UE5 in M periods in an embodiment;

[0108] FIG. 15 is a block diagram of a structure of a cross-satellite handover apparatus in an embodiment;

[0109] FIG. 16 is an internal structure diagram of a network device in one embodiment. DETAILED DESCRIPTION

[0110] The embodiments of the present application will be described in detail with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical scheme of the present application, and therefore only serve as examples, but cannot be used to limit the protection scope of the present application.

[0111] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the specification herein is for describing particular embodiments only and is not intended to be limiting of the application; the use of the terms "include," "includes" and "including" in the description and the claims herein and the above detailed description of embodiments are intended to be inclusive of aspects that would be considered equivalents by one of ordinary skill in the art.

[0112] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the technical features indicated. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0113] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0114] In some cases, for the sake of brevity and / or clarity, individual embodiments can be described using a single embodiment with multiple features. It is to be understood that the multiple features described in such cases can be provided separately (e.g., in different embodiments) or in any suitable combination. Conversely, where different features are described in connection with different embodiments, it is to be understood that these different features can be combined in a single embodiment, unless otherwise indicated or implied. This principle applies similarly to the claims, which can be reorganized in any suitable combination, i.e., any claim can be modified to include any feature defined in another claim.

[0115] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents a "or" relationship between the front and rear associated objects.

[0116] In this application, unless otherwise stated or implied, the phrase "at least one" followed by a listing of items refers to any combination of those items, including single members. Whether the expression "at least one of a, b, or c" or "at least one of a, b, and c" is used, it is intended to cover the following seven cases: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, and the combination of a, b, and c.

[0117] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0118] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like indicate the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the embodiments of the present application and simplifying the description, and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0119] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing", and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or communicatively connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication or interaction relationship of two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0120] FIG. 1 is a schematic diagram of an application scenario of a cross-satellite handover method according to an embodiment of the present application. As shown in FIG. 1, the scenario includes a network device 100, a satellite 200, and a user equipment 300. The network device 100 and the user equipment 300 perform data transmission through the satellite 200.

[0121] The network device 100 can be a base station, a satellite control unit, etc., and the disclosure does not limit the network device. The network device is responsible for data transmission and signal reception in the satellite network. The user equipment 300 can be a device that provides voice and / or other service data connectivity to a user, or a handheld device with wireless connection function, or other processing devices connected to a wireless modem. The wireless terminal can communicate with one or more core networks through a radio access network (RAN). The wireless terminal can be a mobile terminal, such as a mobile phone (or called "cellular" phone) and a computer with a mobile terminal, for example, a portable, pocket, handheld, built-in computer or vehicle-mounted mobile device, which exchanges language and / or data with the radio access network. The wireless terminal can also be called a system, subscriber unit, subscriber station, mobile station, mobile, remote station, remote terminal, access terminal, user terminal, user agent, user device or user equipment, which are not limited here.

[0122] The satellite 200, for example, a low earth orbit satellite, is not stationary relative to the ground, but is always in motion. Therefore, the time length of the low earth orbit satellite covering the user equipment (UE, User Equipment) is limited. For example, the low earth orbit satellite with an orbital height of 1150km, the moving speed of the subsatellite point of the satellite on the ground is about 7.8km / s, and the time length of the low earth orbit satellite covering the stationary user equipment is several minutes. The user equipment needs to switch from the old satellite to the new satellite in the overlapping area of the coverage of the two satellites to ensure the continuity of the communication service.

[0123] The satellite ephemeris is a series of parameters used to represent the position and running speed of the satellite. Common satellite ephemeris includes orbit 6 elements, orbit 12 elements, orbit 16 elements and orbit 18 elements. Taking the orbit 6 elements as an example, the orbit 6 elements include the semi-major axis of the orbit, the eccentricity, the orbit inclination, the argument of perigee, the right ascension of the ascending node and the true anomaly. The more orbit parameters contained in the satellite ephemeris, the more accurate the satellite position and running speed derived.

[0124] In order to realize interference avoidance and improve the strength of received signals, a satellite system usually scans the ground with narrow beams, also known as spot beams. A beam scans a region of the ground at a certain time, which is referred to as a beam position. If multiple users are concentrated in the same beam position, a network device can use a beam to scan the positions of these users at the same time. The area of a beam position is not fixed and is related to the beam width and the beam elevation angle. The greater the beam width, the greater the area of the beam position. The beam elevation angle affects the shape of the beam position. When the elevation angle is 0°, the beam position is approximately circular. When the elevation angle is greater than 0°, the beam position is approximately elliptical. The greater the elevation angle, the longer the major axis of the ellipse. A satellite supports multiple beams, different beams support scanning different positions of the ground, and the same beam can also scan different positions of the ground in a time-division manner. The coverage area of a satellite contains multiple beam positions. A satellite supports configuring the beam width and the beam elevation angle for different beams, so the coverage areas of different beam positions in the same satellite are different and can have a large difference.

[0125] Therefore, in the prior art, for beam positions with different coverage area sizes, the first method is used, in which a network device derives a satellite service end time for a beam position, and all users share the same satellite service end time. The granularity of the overall satellite service end time determined by the network device is large, resulting in low accuracy of user switching. The second method is used, in which the network device determines a satellite service end time for each user according to the position information of each user for beam positions with different coverage area sizes. If the coverage area of a beam position is small and the positions of all users in the beam position are close, the network device needs to calculate the satellite service end time for each user, which results in a large amount of calculation of the network device and large consumption of calculation resources, and low efficiency of user switching.

[0126] It should be noted that the beneficial effects or technical problems solved by the embodiments of the present application are not limited to this, but can also be other implicit or related problems. For details, please refer to the description of the following embodiments.

[0127] The technical solutions of the present application and how the technical solutions solve the above technical problems will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes can not be described again in some embodiments. The embodiments of the present application will be described below with reference to the drawings.

[0128] In some embodiments, as shown in FIG. 2, a cross-satellite handover method is provided. The method is applied to the network device in FIG. 1, for example, and includes the following steps:

[0129] Step 201, determining the range parameters of the beam coverage area of each beam position.

[0130] The range parameter includes the center position, the long axis length and the short axis length of each wave bit coverage area.

[0131] In the implementation, since the satellite beam scans the ground, the shape formed by the boundary of the wave bit coverage area is an ellipse, the ellipse includes the center, the long axis and the short axis, therefore, the long axis of the wave bit coverage area refers to the long axis of the ellipse formed by the boundary of the wave bit coverage area. The short axis of the wave bit coverage area refers to the short axis of the ellipse formed by the boundary of the wave bit coverage area. The center of the wave bit coverage area refers to the center of the ellipse formed by the boundary of the wave bit coverage area. When the eccentricity of the ellipse is 1, it is a circle, at this time, the long axis and the short axis of the ellipse have the same length, therefore, the disclosure takes the general case, i.e. the shape formed by the boundary of the wave bit coverage area is an ellipse, the network device calculates the range parameter of the wave bit coverage area for each wave bit of the satellite with user access, and specifically, the range parameter of the wave bit coverage area of each wave bit in the elliptical shape can be determined based on the wave bit distribution information of the satellite. The range parameter can include the center position, the long axis length and the short axis length of each wave bit coverage area.

[0132] In some embodiments, when the network device determines the long axis length in the range parameter, it can be determined by at least one of the following ways:

[0133] 1. The wave bit distribution information of the satellite includes the beam width θ of the beam, the beam elevation angle φ, etc., and then the network device determines the user elevation angle θ based on the beam width θ, the maximum beam elevation angle φ and the satellite orbit height h. u , that is, the user elevation angle θ is calculated by formula (1) u . Then, based on the user elevation angle θ u , the intermediate quantities α1 and α2 are calculated, that is, calculated by formulas (2) and (3). The α1 and α2 represent intermediate angle parameters in the process of calculating the area of the ellipse. Finally, based on the actual values of α1 and α2 obtained from formulas (2) and (3), the long axis length (d1) and the short axis length (d2) of the wave bit coverage area are derived and calculated. All the formulas required in the above process are as follows:

[0134] d1=r(α1-α2) (4)

[0135] Wherein, asin appearing in the formula represents the inverse sine function, acos represents the inverse cosine function, and r is the radius of the earth.

[0136] 2. The network device supports pre-configuring the long axis length of the wave bit coverage area, then the network device can pre-configure the long axis length of the wave bit coverage area corresponding to the wave bit based on the wave bit of different beams.

[0137] 3. The network device supports a pre-configuration mode or a notification mode by other network elements (e.g., a ground control center) to obtain the location parameters of the coverage area of each beam. The location parameters include a longitude range of the coverage area and a latitude range of the coverage area. Then, the network device calculates a maximum diagonal line length in the coverage area of each beam according to the location parameters of the coverage area of the beam, and takes the maximum diagonal line length as a major axis length of the coverage area of the beam.

[0138] In step 202, the network device determines a first satellite service end time corresponding to the center position of the coverage area of the beam based on the satellite ephemeris and the center position of the coverage area of the beam.

[0139] In implementation, the satellite ephemeris is a series of parameters used to represent the position and running speed of the satellite. The network device calculates the first satellite service end time t0 corresponding to the center position of the coverage area of the beam based on the satellite ephemeris in a future period of time and the center position of the coverage area of the beam.

[0140] In step 203, the network device determines a calculation strategy of the satellite service end time based on a comparison result of the major axis length of the coverage area of the beam and a preset distance threshold value, and calculates the satellite service end time of each user in the coverage area of the beam based on the calculation strategy and the first satellite service end time.

[0141] The satellite service end time is used for cross-satellite handover of the user.

[0142] In implementation, the calculation strategy includes a first calculation strategy and a second calculation strategy. When the major axis length of the coverage area of the beam is less than or equal to the distance threshold value D1, the first calculation strategy is executed. The first calculation strategy takes the first satellite service end time as the satellite service end time of each user. When the major axis length of the coverage area of the beam is greater than the distance threshold value D1, the second calculation strategy is executed. The second calculation strategy calculates the satellite service end time of each user based on the range parameters of the coverage area of the beam and the satellite moving speed.

[0143] Therefore, the network device is provided with the distance threshold value D1. For each coverage area of the beam, the network device compares the major axis length of the coverage area of the beam with the preset distance threshold value D1 to obtain a comparison result. Then, the network device adaptively adjusts the calculation strategy of the satellite service end time of each user in the coverage area of the beam based on the comparison result. In this way, the network device can calculate the satellite service end time of each user in the coverage area of the beam based on the determined calculation strategy (the first calculation strategy or the second calculation strategy) and the first satellite service end time.

[0144] In some embodiments, for the case that a plurality of wave position coverage areas correspond to a single satellite, the network device can adaptively determine the calculation strategy of the satellite service end time for each wave position coverage area, and will not use one calculation method to calculate the satellite service end time of the user due to the wave position coverage area being too large or too small, resulting in low accuracy of the satellite service end time of the user or causing large resource overhead. Further, after determining the satellite service end time of each user in the wave position coverage area, the satellite service end time can further trigger the cross-satellite switching process of the user. The subsequent process of user cross-satellite switching is described in detail in the subsequent process of the present disclosure, which will not be described here.

[0145] In the above cross-satellite switching method, the calculation strategy of the satellite service end time of the user is adaptively adjusted according to the size of the wave position coverage area, which not only ensures the accuracy of the satellite service end time of the user, but also avoids the large calculation amount of the network device and the increase of the calculation resource overhead, and improves the efficiency of user switching.

[0146] In an exemplary embodiment, as shown in FIG. 3, different calculation strategies of the satellite service end time are adaptively adjusted according to the size of the wave position coverage area, and the size of the wave position coverage area is determined by a preset distance threshold value. Specifically, the specific processing process of step 203 includes:

[0147] Step 301: If the length of the long axis of the wave position coverage area is less than or equal to the distance threshold value, the first satellite service end time is determined as the satellite service end time of each user in the wave position coverage area.

[0148] In implementation, if the length of the long axis of the wave position coverage area is less than or equal to the distance threshold value, it indicates that the current wave position corresponds to a relatively small wave position coverage area, and the users in the wave position coverage area are relatively concentrated. Therefore, the network device can only use the first satellite service end time of the center position of the wave position coverage area to represent the satellite service end time of each user, that is, the network device determines the first satellite service end time as the satellite service end time of each user in the wave position coverage area.

[0149] Step 302: If the length of the long axis of the wave position coverage area is greater than the distance threshold value, the satellite service end time of each user in the wave position coverage area in the target time interval is predicted according to the range parameter of the wave position coverage area and the satellite moving speed.

[0150] In implementation, if the length of the long axis of the wave position coverage area is greater than the distance threshold value, it indicates that the wave position coverage area corresponding to the current wave position has a large range, and the users in the wave position coverage area are relatively dispersed. Therefore, the network device needs to calculate the satellite service end time of each user respectively. Specifically, the network device predicts the satellite service end time of each user in the wave position coverage area in the target time interval according to the range parameter of the wave position coverage area, the first satellite service end time and the satellite moving speed. In this process, the position information of each user in the target time interval needs to be determined, and then the satellite service end time of each user is calculated based on the position information of each user and the range parameter of the wave position coverage area.

[0151] The specific process of calculating the satellite service end time of each user in the wave position coverage area in the target time interval includes: predicting the position of the satellite in the target time interval based on the satellite ephemeris. Then, the network device derives the position of the satellite subsatellite point based on the position of the satellite, and estimates the target time interval based on the moving speed of the satellite subsatellite point position, the range parameter in the wave position coverage area and the first satellite service end time. The specific calculation process of the target time interval will be described in detail in the following embodiments.

[0152] Then, in the target time interval, the network device combines the user terminal position, the satellite ground coverage radius Rcell, and finds the distance between the user (user terminal UE) and the satellite subsatellite point by traversing the positions of multiple satellite subsatellite points in the target time interval, to obtain the latest time when the distance is not more than the satellite ground coverage radius Rcell, which is the latest time of the switching of each user.

[0153] Wherein, the target time interval can be represented as (t0-deltaT1, t0+deltaT2), and the target time interval can be determined by the length of the long axis of the wave position coverage area and the satellite moving speed. t0 is the first satellite service end time, deltaT1>0, deltaT2>0.

[0154] In some embodiments, if the position information of the user is updated, and the length of the long axis of the coverage area of the wave position where the user is located is still greater than the distance threshold value D1, the network device needs to recalculate the satellite service end time of the user, and then determine the latest time of the switching of the updated user. longAxis

[0155] In some embodiments, the network device obtains the position information of the user, including at least one of the following ways:

[0156] 1. The user actively reports the position information to the network device, and the network device obtains the position information of the user;

[0157] ​2. The network device predicts the user position at a certain time according to the position information and speed information reported by the user before.

[0158] 3. The network device estimates the speed of the user according to the multiple position information reported by the user before, and then predicts the user position at a certain time according to the latest reported position information and the estimated speed, to obtain the position information of the user.

[0159] In the above cross-satellite handover method, the end time of the satellite service of the user is adaptively adjusted according to the size of the wave position coverage area, which not only ensures the accuracy of the end time of the satellite service of the user, but also avoids the excessive calculation of the network device and the increase of the calculation resource consumption, thereby improving the efficiency of the user handover.

[0160] In some embodiments, as shown in FIG. 4, the method further includes:

[0161] Step 401: determining the latest time of user handover based on the cross-satellite handover duration of the user and the end time of the satellite service of each user in the wave position coverage area.

[0162] In implementation, since the cross-satellite process also consumes a certain time when the user cross-satellite handover is performed, the network device can further determine the latest time of user handover based on the end time of the satellite service of each user and the cross-satellite handover duration of the user after determining the end time of the satellite service of each user in the wave position coverage area. Then, the network device triggers the user handover of the user before the latest time of user handover, which can ensure that the user has been handed over to the adjacent satellite before the end time of the satellite service of the user, thereby ensuring the continuity of the service. In some embodiments, the latest time of user handover is determined by subtracting the cross-satellite handover duration T1 from the end time of the satellite service of the user.

[0163] The cross-satellite handover duration T1 of the user includes the total delay caused by the control plane processing and the data plane processing in the cross-satellite handover.

[0164] Step 402: constructing a first information table.

[0165] The first information table includes the user identifier of each user in the wave position coverage area and the latest time of handover of each user.

[0166] In implementation, the network device constructs and maintains a table, referred to as a first information table, at the latest time of user switching corresponding to each user in each beam coverage area of the satellite. The first information table records the latest time of user switching of each user in each beam coverage area contained by the satellite, and records the user identification of the user at the time of recording to distinguish and mark the latest time of user switching. In some embodiments, the first information table is represented as list1. The table format of list1 is shown in Table 1. When the satellite accesses a new user, the network device can add the user identification of the new user and the latest time of user switching of the new user in list1. When an existing user disconnects from the satellite, the network device can also delete the user identification of the existing user and the latest time of user switching of the user in list1.

[0167] Table 1

[0168] The list1 records according to the user, and contains the user identification of the user and the latest time of switching corresponding to the user.

[0169] In this embodiment, the latest time of user switching is determined based on the user cross-satellite switching duration and the end time of satellite service of the user, and the latest time of user switching is recorded in the first information table maintained by the network device, so as to trigger the cross-satellite switching based on the latest time information recorded in the first information table, avoid the omission of cross-satellite switching, and improve the success rate of user cross-satellite switching.

[0170] In an exemplary embodiment, as shown in FIG. 5, in the case that a single satellite supports parallel processing of multiple user switching, the satellite can process multiple user cross-satellite switching at the same time. In the process of performing user cross-satellite switching, the network device also maintains a table for recording users that need to perform cross-satellite switching at the switching period, so the method further comprises:

[0171] Step 501: taking the time when the first user accesses the satellite as the starting time of the first switching period, and constructing a second information table containing multiple switching periods based on the preset period length and the starting time of the first switching period.

[0172] In implementation, the network device takes T3 as switching period, and periodically predicts switching time of multiple users in multiple (for example, M, M is a positive integer) switching periods T3 in the future. Specifically, T3≥T1 (user cross-satellite switching duration). The network device takes the time when the first user accesses the satellite as the starting time of the first switching period, and starts to divide multiple T3, so as to construct a second information table containing multiple switching periods according to the obtained multiple switching periods T3. The second information table is used to record users needing to perform user switching in each switching period. The second information table is represented as list2, and the table format of list2 is shown in Table 2. When the second information table is initially created, the user list contained in each switching period in the second information table is empty, that is, does not contain any user identifier.

[0173] Table 2

[0174] Each switching period in list2 corresponds to a period number, each switching period records the starting time of the switching period, and after the second information table is continuously updated, each switching period in the second information table contains the user identifier of the user needing to perform switching.

[0175] In step 502, based on the latest switching time of each user contained in the first information table, the user identifier corresponding to each user is divided into the user list corresponding to each switching period in the second information table.

[0176] In implementation, the network device establishes an association relationship between the first information table and the second information table, and updates the user information in the second information table through the first information table. The specific implementation is that the network device divides the user identifier corresponding to each user into the user list corresponding to each switching period in the second information table based on the latest switching time of each user contained in the first information table. For example, taking the first switching period in the second information table as an example, when the starting time of the first switching period in the second information table arrives, that is, when list2 is created, the network device updates the user identifier falling into the first switching period into the user list of the first switching period in list2 according to the latest switching time of each user contained in the first information table.

[0177] In step 503, when the starting time of the current switching period arrives, the cross-satellite switching process for each user in the user list corresponding to the current switching period is triggered.

[0178] In implementation, when the start time of the current switching period is reached, the network device triggers the inter-satellite handover procedure for each user in the user list corresponding to the current switching period. For example, when the start time of the i(th) (i > 1) switching period (i.e. the end time of the (i-1)th period) is reached, all parameters of the (i-1)th period in the table list2 are deleted, and the parameters of the (i+M-1)th period are added, including the start time of the (i+M-1)th period and an empty user list. Then the network device updates the "user list" of the i-th period to the (i+M-1)th period in the table list2 according to step 502. After updating the table list2, the inter-satellite handover procedure of each user in the user list of the i-th period is triggered. The inter-satellite handover procedure initiated by the network device to the current satellite and the adjacent satellite will be described in detail in the following embodiments, and will not be described here.

[0179] In the embodiment, by maintaining the first information table and the second information table, the latest time of user switching of each user is recorded, and the inter-satellite handover procedure of the user is triggered, thereby ensuring the success rate of the overall inter-satellite handover.

[0180] In an exemplary embodiment, as shown in FIG. 6, the network device divides the user identifier corresponding to each user into the user list corresponding to each switching period of the second information table based on the latest time of user switching of each user contained in the first information table, so as to trigger the inter-satellite handover procedure based on the second information table. The specific processing procedure of step 502 includes:

[0181] Step 601: traversing the latest time of user switching of each user contained in the first information table.

[0182] In implementation, the network device traverses the latest time of user switching of each user contained in the first information table. In the second information table, each switching period corresponds to a switching time interval. Therefore, the network device queries and confirms which switching time interval of the second information table the latest time of user switching of each user falls into.

[0183] Step 602: for each user, if the latest time of user switching is within the first target switching period of the second information table, the user identifier of the user is added to the user list corresponding to the first target switching period.

[0184] The first target switching period is any switching period in the second information table.

[0185] In implementation, for each user in the first information table, the query of the latest time of user switching is performed in sequence, if the user switching latest time of the current user falls into the first target switching period of the second information table, the network device adds the user identification of the user to the user list corresponding to the first target switching period of the second information table. That is, the switching latest time of each user in the table list1 is traversed. If the switching latest time of the user falls in the jth period, 1≤j≤M, the user identification is added to the user list of the period number j in the table list2. In this way, the users in the first information table are respectively classified into the user lists of different switching periods in the second information table.

[0186] In some embodiments, the user list corresponding to each first target switching period in the initial second information table is empty, and as the user switching latest time of each user in the first information table falls into each first target switching period, the user identification is added to the user list corresponding to each first target switching period.

[0187] In an exemplary embodiment, as shown in FIG. 7, since the number of processes of parallel processing of user switching supported by a single satellite is limited, further processing is required for each user list contained in each switching period in the second information table, and the method further comprises:

[0188] Step 701, traversing each switching period contained in the second information table in descending order of period number.

[0189] In implementation, each switching period in the second information table corresponds to a period number, and the network device traverses each switching period contained in the second information table in descending order of period number, and checks the user list in each switching period in sequence.

[0190] Step 702, in the case that the number of user identifications in the user list corresponding to the second target switching period is greater than the number of processes of parallel processing of user switching supported by a single satellite, sorting the user identifications of each user contained in the second target switching period based on a preset sorting rule to obtain a user sequence.

[0191] In implementation, among each switching period contained in the second information table, there is a second target switching period, and the number of user identifications in the user list corresponding to the second target switching period is greater than the number of processes of parallel processing supported by a single satellite, that is, at this time, the current satellite cannot complete the cross-satellite switching of all users in the user list at one time for the user list corresponding to the second target switching period, and therefore, the network device needs to assist in screening each user in the user list. Therefore, the network device sorts the user identifications of all users in the second target switching period based on a preset sorting rule to obtain a sorted user sequence.

[0192] In step 703, the user identifiers of the first target number of users in the user sequence are reserved, the user identifiers of the subsequent users in the user sequence are deleted, and the deleted user identifiers are added to the user list corresponding to the previous switching period of the second target switching period.

[0193] The target number is equal to the number of processes supported by a single satellite for parallel processing of user switching.

[0194] In implementation, for the sorted user sequence, the network device reserves the user identifiers of the first target number of users in the user sequence and deletes the user identifiers of the subsequent users in the user sequence corresponding to the current second target switching period. The target number of reserved user identifiers is equal to the number of processes supported by a single satellite for user switching, so as to ensure that the satellite can complete user switching for the reserved users at one time. The deleted user identifiers are added to the user list corresponding to the previous switching period of the second target switching period, so as to ensure that the users corresponding to the deleted user identifiers can also be timely cross-satellite switched, and the workload of user cross-satellite switching in each switching period is balanced. For example, the number of processes supported by a single satellite for parallel processing is N, and the current period is the jth period. If the number of user identifiers contained in the jth period exceeds N, the user identifiers of the first N users in the sorted user sequence in the jth period are reserved in the user list of the jth period, and the user identifiers of the other users are deleted from the user list of the jth period and added to the user list of the (j-1)th period.

[0195] In some embodiments, in the second target switching period, the number of users in the user list exceeds the number N of processes supported by a single satellite for parallel processing of user switching, and there is no previous switching period in the second target switching period, that is, there is no switching period with a period number smaller than that of the current second target switching period in the second information table. Therefore, the user identifiers of all the users sorted after N are deleted from the user sequence of the current second target switching period, and these users are subsequently migrated to the adjacent target satellite to be switched by redirection.

[0196] In an example embodiment, the preset sorting rule used for sorting the user list in the second target switching period includes at least one of a sorting rule based on service priority and a sorting rule based on the latest time of user switching.

[0197] In implementation, the network device can select at least one of the preset sorting rules according to the current service demand or actual service processing situation to sort the user list corresponding to the second target switching period. The embodiments of the present disclosure do not limit this.

[0198] In some embodiments, the specific application process of the sorting rule based on the service priority and the sorting rule based on the latest time of user switching is described as follows:

[0199] Application of the sorting rule based on the service priority: in an exemplary embodiment, as shown in FIG. 8, the specific processing procedure of step 702 includes:

[0200] Step 801: sort the user identifiers of the users included in the second target switching period in the order from high to low according to the service priority.

[0201] In implementation, the sorting rule based on the service priority refers to arranging the users in the order from high to low according to the service priority, and arranging the users with the same service priority in the order from later to earlier according to the latest time of switching. Therefore, the network device sorts the user identifiers of the users included in the second target switching period in the order from high to low according to the service priority.

[0202] In some embodiments, the service priority in the present disclosure can be determined according to one or more of the 5QI (5G Quality of Service Indicator) priority of the user service, the ARP (Address Resolution Protocol) priority of the user service, the slice identifier of the user service, the access category of the user, and the access identity of the user, and the present disclosure does not specifically limit the type and number of parameters for determining the service priority.

[0203] Step 802: if there are users with the same service priority, sort the users with the same service priority in the order from later to earlier according to the latest time of user switching to obtain a user sequence.

[0204] In implementation, if there are at least two users with the same service priority, the network device sorts the users with the same service priority in the order from later to earlier according to the latest time of user switching, and merges the partial user sequence after sorting into the overall user sequence to obtain the final user sequence.

[0205] In the present embodiment, the users in the user list included in the second switching period are sorted according to the service priority principle, and when the network device has limited capability to process satellite user switching, the density of user switching can be dispersed in each switching period, and the users with low service priority can be preferentially switched in advance to ensure the overall switching success rate.

[0206] For the application of the ordering rule based on the latest time of user switching: in an example embodiment, as shown in FIG. 9, the specific process of step 702 includes:

[0207] Step 901, ordering the user identities of the users contained in the second target switching period according to the latest time of user switching from later to earlier.

[0208] In implementation, the ordering according to the latest time of user switching is essentially following the time priority principle, which means, arranging the users according to the latest time of switching from later to earlier, and arranging the users with the same latest time of switching according to the service priority from high to low. Therefore, the network device orders the user identities of the users contained in the second target switching period according to the latest time of user switching from later to earlier.

[0209] Step 902, if there are users with the same latest time of user switching, ordering the users with the same service priority according to the service priority from high to low, to obtain the user sequence.

[0210] In implementation, if there are at least two users with the same latest time of user switching, the network device orders these users according to the service priority from high to low, and merges the partial user sequence after ordering into the overall user sequence, to obtain the final user sequence.

[0211] In this embodiment, the users in the user list contained in the second switching period are ordered by the time priority principle, when the network device has limited capability to process satellite user switching, the density of user switching can be dispersed in time domain, and the users with earlier satellite service time are allowed to switch earlier, to ensure the overall switching success rate.

[0212] In an example embodiment, as shown in FIG. 10, the method further includes:

[0213] Step 1001, if there is a first target user whose latest time of user switching is updated in the first information table, deleting the user identity of the first target user in the second information table, or if there is a second target user that is disconnected from the satellite in the first information table, deleting the user identity of the second target user in the second information table.

[0214] In implementation, if the first target user in the first information table exists and the latest time of user switching of the first target user has been updated, the information of the first target user representing the original record is information that has been invalidated, and the network device deletes the user identifier of the first target user in the second information table. For the second target user in the first information table that has been disconnected from the satellite, it is represented that cross-satellite switching of the second target user is no longer needed, and therefore, the user identifier of the second target user is also deleted in the second information table.

[0215] In step 1002, if the third target user that has accessed the satellite is not included in the second information table, the step of dividing the user identifier of each user corresponding to the latest time of user switching of each user included in the first information table into the user list corresponding to each switching period of the second information table is performed.

[0216] In implementation, if the third target user that has accessed the satellite is not added to the second information table, the user identifier of the third target user and the latest time of user switching of the third target user are added to the user list of the target switching period corresponding to the second information table, that is, the process is similar to step 502. For example, if the switching latest time of the third target user falls within the jth period of the second information table, i≤j≤i+M-1 (the last switching period included in the second information table), the user identifier is added to the user list corresponding to the period number j in the second information table.

[0217] In an exemplary embodiment, as shown in FIG. 11, the specific processing process of step 503 includes:

[0218] In step 1101, when the start time of the current switching period is reached, a user switching request is initiated to one or more adjacent satellites for each user in the user list corresponding to the current switching period.

[0219] In implementation, when the start time of the current switching period is reached, the network device initiates a user switching request to one or more adjacent satellites for each user in the user list corresponding to the current switching period. The adjacent satellites give switching request feedback information based on the user switching request in combination with their own attribute conditions, etc.

[0220] In step 1102, the user switching request feedback information of the multiple adjacent satellites is received, and based on the user switching request feedback information, a target satellite for user switching of the user is screened out, and a notification message is sent to the user equipment of the user.

[0221] The notification message is used to instruct the user equipment to switch from the current satellite to the target satellite.

[0222] In implementation, the network device receives user handover request feedback information of multiple adjacent satellites, and based on the user handover request feedback information given by each adjacent satellite, screens out a target satellite for user handover of the user, and then sends a notification message to a user device of the user to notify the user to switch from a current satellite to the target satellite.

[0223] In an exemplary implementation, as shown in FIG. 12, for the case that the long axis length of the wave position coverage area is greater than the preset distance threshold value, the network device calculates, for each user in the wave position coverage area, a satellite service end time of the user in a predicted time interval, and the determination process of the predicted time interval includes the following processes:

[0224] In step 1201, based on the satellite ephemeris and the satellite orbit parameters, the network device determines the moving speed of the subsatellite point of the satellite on the ground.

[0225] In implementation, the network device determines the moving speed of the subsatellite point of the satellite on the ground based on the satellite ephemeris and the satellite orbit parameters. The moving speed of the subsatellite point of the satellite on the ground is denoted as V sat .

[0226] In step 1202, based on the moving speed, the range parameter in the wave position coverage area, and the first satellite service end time, the network device predicts a target time interval in which the satellite service end time of each user in the wave position coverage area is located.

[0227] In implementation, the network device obtains the offset of the target time interval based on the ratio of the long axis length in the range parameter to the moving speed, including a first offset deltaT1 and a second offset deltaT2. Wherein, deltaT1 and deltaT2 can both take values of 0.5*d longAxis / V sat . Wherein, d longAxis represents the long axis length of the wave position coverage area, and V sat represents the moving speed of the subsatellite point of the satellite on the ground. Then, the network device obtains the lower limit threshold t0-deltaT1 of the target time interval according to the difference between the first satellite service end time t0 and the first offset deltaT1, and obtains the upper limit threshold of the target time interval according to the sum t0+deltaT2 of the first satellite service end time t0 and the second offset deltaT2. Thus, the target time interval (t0-deltaT1, t0+deltaT2) containing the lower limit threshold and the upper limit threshold is obtained. In this way, after the target time interval is estimated, the satellite service end time of each user is calculated in the target time interval, and the specific calculation process has been described in detail in step 302 of the above embodiment, which will not be described here.

[0228] In the embodiment, the network device estimates a time interval, so that the satellite ephemeris based on the time interval distinguishes the position information of each user to calculate the satellite service end time of each user. In this way, it is ensured that only the satellite position derived based on the satellite ephemeris within the estimated time interval can reduce the calculation amount of the network device.

[0229] In some embodiments, the disclosure provides a specific example process for calculating the satellite service end time of a user, which includes:

[0230] It is assumed that the wave position distribution under a satellite and the user distribution in the wave position are as shown in FIG. 13. In FIG. 13, the beam 1 of the satellite illuminates the wave position 1 on the ground, and the beam 2 of the satellite illuminates the wave position 2 on the ground. The network device calculates the long axis length dlongAxisBeam1, the short axis length and the center position of the wave position 1 coverage area according to the beam width of the beam 1 and the maximum pitch angle used by the beam 1 in the low-orbit satellite system, to obtain the range parameters of the wave position 1 coverage area corresponding to the beam 1. Then, the network device calculates the satellite service end time t0 beaml of the center position of the wave position 1 coverage area according to the range parameters of the beam 1 coverage area and the satellite ephemeris. Moreover, the network device calculates the long axis length dlongAxisBeam2, the short axis length and the center position of the wave position 2 coverage area according to the beam width of the beam 2 and the maximum pitch angle used by the beam 2 in the low-orbit satellite system, to obtain the range parameters of the wave position 2 coverage area corresponding to the beam 2. Then, the network device calculates the satellite service end time (i.e., the first satellite service end time in the above embodiment) t0 beam2 of the center position of the wave position 2 coverage area according to the center position of the beam 2 coverage area and the satellite ephemeris. The network device pre-sets a distance threshold value D1. The moving speed of the satellite subsatellite point on the ground is V sat .

[0231] The wave position 1 coverage area contains users UE1 and UE2. The wave position 2 coverage area contains users UE3, UE4 and UE5.

[0232] For the wave position 1, it is assumed that the long axis dlongAxisBeam1 of the wave position 1 coverage area is less than the distance threshold value D1, so the network device does not need to derive the satellite service end time of UE1 and UE2 based on the UE1 position and the UE2 position respectively, and sets the satellite service end time of UE1 and UE2 to t0 beaml .

[0233] For beam 2, assuming that the long axis dlongAxisBeam2 of the beam 2 coverage area is greater than the preset distance threshold D1, the network device needs to distinguish the positions of each user to derive the satellite service end time of the user. The network device calculates the satellite service end time of each user in the beam coverage area according to the calculation strategy and the first satellite service end time. Wherein, first, the target time interval is determined for the beam coverage area, then the position information of each user and the target time interval (t0 beam2 -0.5*dlongAxisBeam2 / V sat , t0 beam2 +0.5*dlongAxisBeam2 / V sat ) of the satellite ephemeris are determined, and based on the comparison result of the long axis length of the beam coverage area and the distance threshold D1, it is determined that the calculation strategy corresponds to the second calculation strategy, therefore, based on the range parameters of the beam coverage area and the satellite moving speed in the satellite ephemeris, the satellite service end time of each user is calculated, that is, the satellite service end time t UE3 of UE3, the satellite service end time t UE4 of UE4, and the satellite service end time t UE5 of UE5 are derived respectively.

[0234] If UE1 in beam 1 reports new position information, the network device does not need to recalculate the satellite service end time of UE1.

[0235] If UE3 in beam 2 reports new position information, the network device needs to recalculate the satellite service end time of UE3 based on the latest reported position information of UE3.

[0236] After giving the specific example process of calculating the satellite service end time of the user, the specific process of the network device estimating the latest switching time of each user in the subsequent beam coverage area is introduced in detail, including:

[0237] The network device obtains the satellite service end time of all users under the satellite. The satellite service end time of UE1 and UE2 is t0 beaml , the satellite service end time of UE3 is t UE3 , the satellite service end time of UE4 is t UE4 , and the satellite service end time of UE5 is t UE5 .

[0238] The latest time of triggering user switching is obtained by "the satellite service end time of the user minus the time length T1 of cross-satellite switching", therefore, the latest switching time of UE1, UE2, UE3, UE4, and UE5 is (t0 beaml -T1), (t0beaml - T1), (t UE3 - T1), (t UE4 - T1), (t UE5 - T1), at this time, the first information table specific example, as shown in Table 3:

[0239] Table 3

[0240] The network device estimates the latest switching time of each user at the start time of a period based on the latest time of each user switching and the number of user switching processes supported in parallel for a single satellite.

[0241] Assume that the current time t current is the start time of the i-th period, and assume that the switching latest time of UE1 to UE5, the distribution of M (assuming M = 4) periods is shown in Figure 14, as shown in Figure 14, the switching latest time of UE1, UE2, UE3, and UE5 falls within one of the periods i to i+3. Since the switching latest time of UE4 is after the end time of period i+3, it is not within the range of 4 periods considered at the current time, so wait until the start time of the next period arrives to estimate the switching time of UE4.

[0242] Assume that the network device handles at most one user's inter-satellite switching for a single satellite at the same time, i.e. N = 1, then according to the description of the invention, period i+1 contains 2 users (UE1, UE2), and one user needs to be selected from UE1 and UE2 to migrate to period i. Assume that UE1 establishes 5QI1 flow service and UE2 establishes 5QI6 service flow, and the priority of 5QI1 is higher than that of 5QI6, so the priority of UE1 service is higher than that of UE2 service. At this time, according to the service priority principle, UE2 is moved from period i+1 to period i. Then, the content of the second information table list2 is shown in Table 4:

[0243] Table 4

[0244] The network device determines that only UE2 triggers inter-satellite switching in the i-th period according to the list list2, and the network device immediately triggers the switching process of UE2.

[0245] It should be understood that although each step in the flowcharts of FIGS. 2-12 is shown in sequence according to the direction of the arrow, these steps are not necessarily executed in the order indicated by the arrow. Unless otherwise explicitly stated herein, there is no strict order limitation for the execution of these steps, and these steps can be executed in other orders. Moreover, at least a part of the steps in FIGS. 2-12 can include multiple steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but can be executed alternately or alternately with at least a part of other steps or steps or stages in other steps.

[0246] In some embodiments, as shown in FIG. 15, a cross-satellite switching device is provided, comprising: a first determination module 1501, a second determination module 1502, and a calculation module 1503, wherein:

[0247] The first determination module 1501 is configured to determine a range parameter of a wave position coverage area corresponding to each wave position of the satellite; the range parameter includes a central position and a major axis length of each wave position coverage area;

[0248] The second determination module 1502 is configured to determine a first satellite service end time corresponding to the central position of the wave position coverage area based on the satellite ephemeris and the central position of the wave position coverage area.

[0249] The calculation module 1503 is configured to determine a calculation strategy of the satellite service end time based on a comparison result of the major axis length of the wave position coverage area and a preset distance threshold value, and calculate the satellite service end time of each user in the wave position coverage area based on the calculation strategy and the first satellite service end time; the satellite service end time is used for cross-satellite switching of the user.

[0250] In some embodiments, the calculation module 1503 is specifically configured to determine the first satellite service end time as the satellite service end time of each user in the wave position coverage area if the major axis length of the wave position coverage area is less than or equal to the distance threshold value.

[0251] If the major axis length of the wave position coverage area is greater than the distance threshold value, the satellite service end time of each user in the wave position coverage area in a target time interval is predicted according to the range parameter of the wave position coverage area and the satellite moving speed.

[0252] In some embodiments, the device further comprises:

[0253] The third determination module is configured to determine the latest time of switching of each user based on the cross-satellite switching time length of the user and the satellite service end time of each user in the wave position coverage area.

[0254] The first constructing module is configured to construct a first information table, wherein the first information table comprises user identities of users in a coverage area of a wave position and latest time instants of handover of the users.

[0255] In some embodiments, when a single satellite supports parallel processing of multiple user handovers, the apparatus further comprises:

[0256] The second constructing module is configured to construct a second information table comprising multiple handover periods based on a preset period length and a starting time instant of a first handover period, wherein the starting time instant of the first handover period is a time instant at which a first user accesses the satellite.

[0257] The dividing module is configured to divide the user identities of the users into user lists corresponding to the handover periods in the second information table based on the latest time instants of handover of the users comprised in the first information table.

[0258] The triggering module is configured to trigger a cross-satellite handover process for each user in a user list corresponding to a current handover period when a starting time instant of the current handover period is reached.

[0259] In some embodiments, the dividing module is specifically configured to traverse the latest time instant of handover of each user comprised in the first information table.

[0260] For each user, if the latest time instant of handover of the user is within a first target handover period of the second information table, the user identity of the user is added to a user list corresponding to the first target handover period.

[0261] The first target handover period is any one of the handover periods in the second information table.

[0262] In some embodiments, the apparatus further comprises:

[0263] The traversing and querying module is configured to traverse the handover periods comprised in the second information table in descending order of period numbers.

[0264] The sorting module is configured to sort the user identities of the users comprised in a second target handover period based on a preset sorting rule to obtain a user sequence when the number of user identities in the user list corresponding to the second target handover period is greater than the number of processes of user handover that can be supported by a single satellite in parallel.

[0265] The deleting module is configured to retain the user identities of the first target number of users in the user sequence, delete the user identities of subsequent users in the user sequence, and add the deleted user identities to a user list corresponding to a previous handover period of the second target handover period.

[0266] The target number is equal to the number of processes of user handover that can be supported by a single satellite in parallel.

[0267] In some embodiments, the preset sorting rule comprises at least one of a sorting rule based on service priority and a sorting rule based on the latest time of user switching.

[0268] In some embodiments, the sorting module is specifically configured to sort the user identities of the users included in the second target switching period in descending order of service priority.

[0269] If there are users with the same service priority, the users with the same service priority are sorted in descending order of the latest time of user switching to obtain the user sequence.

[0270] In some embodiments, the sorting module is specifically configured to sort the user identities of the users included in the second target switching period in descending order of the latest time of user switching.

[0271] If there are users with the same latest time of user switching, the users with the same latest time of user switching are sorted in descending order of service priority to obtain the user sequence.

[0272] In some embodiments, the apparatus further comprises:

[0273] The deleting module is configured to delete, in the second information table, the user identity of the first target user if the latest time of user switching of the first target user in the first information table is updated, or delete, in the second information table, the user identity of the second target user if the second target user is disconnected from the satellite.

[0274] The executing module is configured to, if the second information table does not contain the user identity of the third target user who has accessed the satellite, perform the step of dividing the user identity corresponding to each user in the first information table into the user list corresponding to each switching period in the second information table based on the latest time of user switching of each user.

[0275] In some embodiments, the triggering module is specifically configured to, when the start time of the current switching period is reached, initiate a user switching request to one or more adjacent satellites for each user in the user list corresponding to the current switching period.

[0276] The user switching request feedback information of the plurality of adjacent satellites is received, and based on the user switching request feedback information, a target satellite for user switching of the user is screened out, and a notification message is sent to the user equipment of the user.

[0277] The notification message is used to instruct the user equipment to switch from the current satellite to the target satellite.

[0278] In some embodiments, the computing module 1503 is specifically configured to determine a moving speed of a subsatellite point of the satellite on the ground based on satellite ephemeris and satellite orbit parameters.

[0279] Based on the moving speed, the range parameter in the wave position coverage area, and the first satellite service end time, a target time interval in which each user in the wave position coverage area corresponds to a satellite service end time is predicted.

[0280] It should be noted that the above device provided by the embodiments of the present application can realize all the method steps realized by the method embodiments and achieve the same technical effects, and the same parts and beneficial effects of the method embodiments in the embodiments will not be described in detail.

[0281] The network device related to the embodiments of the present application can be a base station, which can include multiple cells providing services for terminals. According to different specific application occasions, the base station can also be called an access point, or can be a device in an access network that communicates with wireless terminal devices through one or more sectors on an air interface, or other names. The network device can be used to exchange received air frames and Internet Protocol (IP) packets as a router between wireless terminal devices and the rest of the access network, which can include an Internet Protocol (IP) communication network. The network device can also coordinate the management of properties of the air interface. For example, the network device related to the embodiments of the present application can be an evolved network device (eNB or e-NodeB) in a long term evolution (LTE) system, a 5G base station (gNB) in a 5G network architecture, etc., and can also be a home evolved base station (HeNB), a relay node, a home base station (femto), a pico base station, a network test device, etc., which are not limited in the embodiments of the present application. In some network structures, the network device can include a centralized unit (CU) node and a distributed unit (DU) node, and the centralized unit and the distributed unit can also be arranged geographically apart.

[0282] In some embodiments, as shown in FIG. 16, the network device includes a memory 1620, a transceiver 1610, and a processor 1600;

[0283] The memory 1620 is configured to store a computer program, the transceiver is configured to transceive data under the control of the processor, and the processor is configured to read the computer program in the memory and perform the following operations:

[0284] determining a range parameter of the wave position coverage area corresponding to each wave position of the satellite; the range parameter comprises a central position of the wave position coverage area and a major axis length of the wave position coverage area;

[0285] determining a first satellite service end time corresponding to the central position of the wave position coverage area based on the satellite ephemeris and the central position of the wave position coverage area;

[0286] determining a calculation strategy of the satellite service end time based on a comparison result of the major axis length of the wave position coverage area and a preset distance threshold value, and calculating the satellite service end time of each user in the wave position coverage area based on the calculation strategy and the first satellite service end time; the satellite service end time is used for cross-satellite switching of the user.

[0287] In some embodiments, the calculation of the satellite service end time of each user in the wave position coverage area based on the calculation strategy and the first satellite service end time comprises:

[0288] if the major axis length of the wave position coverage area is less than or equal to the distance threshold value, determining the first satellite service end time as the satellite service end time of each user in the wave position coverage area;

[0289] if the major axis length of the wave position coverage area is greater than the distance threshold value, predicting the satellite service end time of each user in the wave position coverage area in a target time interval according to the range parameter of the wave position coverage area and the satellite moving speed.

[0290] In some embodiments, the processor 1600 is further configured to read the computer program in the memory and perform the following operations:

[0291] determining a latest time of user switching based on the user cross-satellite switching duration and the satellite service end time of each user in the wave position coverage area;

[0292] constructing a first information table, the first information table comprising the user identifier of the user in the wave position coverage area and the latest time of user switching.

[0293] In some embodiments, in the case that a single satellite supports parallel processing of multiple user switching, the processor 1600 is further configured to read the computer program in the memory and perform the following operations:

[0294] taking the time when the first user accesses the satellite as the starting time of the first switching period, and constructing a second information table comprising multiple switching periods based on the preset period length and the starting time of the first switching period;

[0295] dividing the user identifier corresponding to each user into the user list corresponding to each switching period of the second information table based on the latest time of user switching of each user contained in the first information table.

[0296] When reaching the start time of the current switching period, a cross-satellite switching process for each user in the user list corresponding to the current switching period is triggered to be performed.

[0297] In some embodiments, based on the latest time of user switching of each user contained in the first information table, the user identifier corresponding to each user is divided into the user list corresponding to each switching period of the second information table, including:

[0298] The latest time of user switching of each user contained in the first information table is traversed;

[0299] For each user, if the latest time of user switching of the user is within the first target switching period of the second information table, the user identifier of the user is added to the user list corresponding to the first target switching period;

[0300] The first target switching period is any one switching period in the second information table.

[0301] In some embodiments, the processor 1600 is further configured to read a computer program in the memory and perform the following operations:

[0302] The switching periods contained in the second information table are traversed in descending order of period number;

[0303] In the case where the number of user identifiers in the user list corresponding to the second target switching period is greater than the number of processes of user switching supported by a single satellite in parallel processing, the user identifiers of each user contained in the second target switching period are sorted based on a preset sorting rule to obtain a user sequence;

[0304] The user identifiers of the first target number of users in the user sequence are retained, the user identifiers of the subsequent users in the user sequence are deleted, and the deleted user identifiers are added to the user list corresponding to the previous switching period of the second target switching period;

[0305] The target number is equal to the number of processes of user switching supported by a single satellite in parallel processing.

[0306] In some embodiments, the preset sorting rule includes at least one of a sorting rule based on service priority and a sorting rule based on the latest time of user switching.

[0307] In some embodiments, based on the preset sorting rule, the user identifiers of each user contained in the second target switching period are sorted to obtain a user sequence, including:

[0308] The user identifiers of each user contained in the second target switching period are sorted in descending order of service priority;

[0309] If there are users with the same service priority, the users with the same service priority are sorted in a sequence from later to earlier according to the latest time of user switching, to obtain a user sequence.

[0310] In some embodiments, the user identifiers of the users included in the second target switching period are sorted based on a preset sorting rule to obtain a user sequence, including:

[0311] The user identifiers of the users included in the second target switching period are sorted in a sequence from later to earlier according to the latest time of user switching.

[0312] If there are users with the same latest time of user switching, the users with the same service priority are sorted in a sequence from high to low according to the service priority, to obtain a user sequence.

[0313] In some embodiments, the processor 1600 is further configured to read a computer program in the memory and perform the following operations:

[0314] If there is a first target user whose latest time of user switching is updated in the first information table, the user identifier of the first target user is deleted in the second information table, or if there is a second target user that is disconnected from the satellite in the first information table, the user identifier of the second target user is deleted in the second information table.

[0315] If the second information table does not include the user identifier of a third target user who has accessed the satellite, the step of dividing the user identifier of each user into the user list corresponding to each switching period of the second information table based on the latest time of user switching of each user included in the first information table is performed.

[0316] In some embodiments, when the start time of the current switching period is reached, the cross-satellite switching process for the user list corresponding to the current switching period is triggered, including:

[0317] When the start time of the current switching period is reached, a user switching request is initiated to one or more adjacent satellites for each user in the user list corresponding to the current switching period.

[0318] User switching request feedback information of the multiple adjacent satellites is received, and based on the user switching request feedback information, a target satellite for user switching of the user is screened out, and a notification message is sent to the user equipment of the user.

[0319] The notification message is used to instruct the user equipment to switch from the current satellite to the target satellite.

[0320] In some embodiments, if the length of the long axis of the wave position coverage area is greater than the distance threshold, the processor 1600 is further configured to read a computer program in the memory and perform the following operations:

[0321] determine the moving speed of the subsatellite point of the satellite on the ground based on the satellite ephemeris and the satellite orbit parameters;

[0322] predict the target time interval in which the end time of the satellite service for each user in the wave position coverage area is located based on the moving speed, the range parameter in the wave position coverage area, and the end time of the satellite service of the first satellite.

[0323] In some embodiments, a computer readable storage medium is provided, and the computer readable storage medium has a computer program stored thereon, and the computer program is executed by a processor to implement the steps in each method embodiment described above.

[0324] Any combination of the technical features in the above embodiments can be made. To make the description concise, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combination of the technical features does not exist, it should be considered as the scope of the present application.

[0325] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the specification of the present application. In particular, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for inter-satellite handover, the method being applied to a network device, the method comprising: determining a range parameter of a wave position coverage area corresponding to each wave position of a satellite, the range parameter comprising a center position and a major axis length of each wave position coverage area; determining a first satellite service end time corresponding to the center position of the wave position coverage area based on a satellite ephemeris and the center position of the wave position coverage area; determining a calculation strategy of a satellite service end time based on a comparison result of the major axis length of the wave position coverage area and a preset distance threshold, and calculating the satellite service end time of each user in the wave position coverage area based on the calculation strategy and the first satellite service end time, the satellite service end time being used for inter-satellite handover of the user; and wherein the calculation of the satellite service end time of each user in the wave position coverage area based on the calculation strategy and the first satellite service end time comprises: if the major axis length of the wave position coverage area is less than or equal to the distance threshold, determining the first satellite service end time as the satellite service end time of each user in the wave position coverage area; and if the major axis length of the wave position coverage area is greater than the distance threshold, predicting the satellite service end time of each user in the wave position coverage area in a target time interval according to the range parameter of the wave position coverage area and a satellite moving speed. The method further comprises: determining a latest time of handover of each user based on a user inter-satellite handover duration and the satellite service end time of each user in the wave position coverage area; and constructing a first information table comprising a user identifier of a user in the wave position coverage area and the latest time of handover of each user. In a case where a single satellite supports parallel processing of multiple user handovers, the method further comprises: taking a time when a first user accesses the satellite as a start time of a first handover period, and constructing a second information table comprising multiple handover periods based on a preset period duration and the start time of the first handover period; dividing the user identifier corresponding to each user into a user list corresponding to each handover period of the second information table based on the latest time of handover of each user included in the first information table; and triggering an inter-satellite handover process for each user in a user list corresponding to a current handover period when a start time of the current handover period is reached. The division of the user identifier corresponding to each user into a user list corresponding to each handover period of the second information table based on the latest time of handover of each user included in the first information table comprises: traversing the latest time of handover of each user included in the first information table; and for each user, if the latest time of handover of the user is within a first target handover period of the second information table, adding the user identifier of the user to a user list corresponding to the first target handover period.

2. The method of claim 1, wherein, The method further comprises: traversing each handover period included in the second information table in descending order of period number. ​ ​ 3. The method of claim 1, wherein, ​ ​ ​ 4. The method of claim 3, wherein, ​ ​ ​ ​ 5. The method of claim 4, wherein, ​ ​ ​ ​ 6. The method of claim 5, wherein, ​ ​ In a case where a quantity of user identities in a user list corresponding to a second target switching period is greater than a quantity of processes of user switching supported by the single satellite for parallel processing, sorting, based on a preset sorting rule, the user identities of the users included in the second target switching period to obtain a user sequence; reserving user identities of a first target quantity of users in the user sequence, deleting user identities of subsequent users in the user sequence, and adding the deleted user identities to a user list corresponding to a previous switching period of the second target switching period; wherein the target quantity is equal to the quantity of processes of user switching supported by the single satellite for parallel processing.

7. The method of claim 6, wherein, The preset sorting rule includes at least one of a sorting rule based on a service priority and a sorting rule based on a latest time of user switching.

8. The method of claim 7, wherein, The sorting, based on the preset sorting rule, of the user identities of the users included in the second target switching period to obtain a user sequence includes: sorting the user identities of the users included in the second target switching period in an order from high to low of service priority; if there are users with the same service priority, sorting the users with the same service priority in an order from later to earlier of the latest time of user switching to obtain a user sequence.

9. The method of claim 7, wherein, The sorting, based on the preset sorting rule, of the user identities of the users included in the second target switching period to obtain a user sequence includes: sorting the user identities of the users included in the second target switching period in an order from later to earlier of the latest time of user switching; if there are users with the same latest time of user switching, sorting the users with the same service priority in an order from high to low of service priority to obtain a user sequence.

10. The method of claim 4, wherein, The method further includes: if there is a first target user whose latest time of user switching is updated in the first information table, deleting a user identity of the first target user in the second information table, or if there is a second target user that is disconnected from the satellite in the first information table, deleting a user identity of the second target user in the second information table; if a third target user that has accessed the satellite does not have a user identity included in the second information table, performing the step of dividing, based on the latest time of user switching of each user included in the first information table, the user identity of each user to a user list corresponding to each switching period of the second information table.

11. The method of claim 4, wherein, The triggering, when a start time of a current switching period is reached, of a cross-satellite switching process for each user in a user list corresponding to the current switching period includes: when the start time of the current switching period is reached, initiating, for each user of the user list corresponding to the current switching period, a user switching request to one or more neighboring satellites; receiving user switching request feedback information of the multiple neighboring satellites, and based on the user switching request feedback information, screening out a target satellite for user switching of the user, and sending a notification message to a user equipment of the user; The notification message is used to instruct the user equipment to switch from a current satellite to the target satellite.

12. The method of claim 2, wherein, If the long axis length of the wave position coverage area is greater than the distance threshold value, the method further comprises: determining a moving speed of a subsatellite point of the satellite on the ground based on the satellite ephemeris and satellite orbit parameters; predicting target time intervals in which the satellite service end time of each user in the wave position coverage area is located based on the moving speed, the range parameter in the wave position coverage area, and the first satellite service end time.

13. A cross-satellite switching device, the device being applied to a network equipment, the device comprising: a first determining module configured to determine a range parameter of a wave position coverage area of each wave position corresponding to a satellite; the range parameter comprising a center position and a long axis length of each wave position coverage area; a second determining module configured to determine a first satellite service end time corresponding to the center position of the wave position coverage area based on satellite ephemeris and the center position of the wave position coverage area; a calculating module configured to determine a calculation strategy of a satellite service end time based on a comparison result of the long axis length of the wave position coverage area and a preset distance threshold value, and calculate the satellite service end time of each user in the wave position coverage area based on the calculation strategy and the first satellite service end time; the satellite service end time is used for cross-satellite switching of the user.

14. A network device comprising: a memory, a transceiver, and a processor; The memory is configured to store computer programs; the transceiver is configured to transceive data under the control of the processor; and the processor is configured to read the computer programs in the memory and perform the following operations: determine a range parameter of a wave position coverage area of each wave position corresponding to a satellite; the range parameter comprising a center position and a long axis length of each wave position coverage area; determine a first satellite service end time corresponding to the center position of the wave position coverage area based on satellite ephemeris and the center position of the wave position coverage area; determine a calculation strategy of a satellite service end time based on a comparison result of the long axis length of the wave position coverage area and a preset distance threshold value, and calculate the satellite service end time of each user in the wave position coverage area based on the calculation strategy and the first satellite service end time; the satellite service end time is used for cross-satellite switching of the user.

15. The network device of claim 14, wherein, The calculation of the satellite service end time of each user in the wave position coverage area based on the calculation strategy and the first satellite service end time comprises: if the long axis length of the wave position coverage area is less than or equal to the distance threshold value, the first satellite service end time is determined as the satellite service end time of each user in the wave position coverage area; if the long axis length of the wave position coverage area is greater than the distance threshold value, the satellite service end time of each user in the wave position coverage area in a target time interval is predicted according to the range parameter of the wave position coverage area and the moving speed of the satellite.

16. The network device of claim 14, wherein, The processor is further configured to read the computer programs in the memory and perform the following operations: determine a latest time of switching of the user based on a time length of cross-satellite switching of the user and a time of ending of satellite service of each user in the coverage area of the beam position; construct a first information table, the first information table containing user identification of the user in the coverage area of the beam position and the latest time of switching of the user.

17. The network device of claim 16, wherein, In a case where a single satellite supports parallel processing of multiple user switching, the processor further reads the computer program in the memory and performs the following operations: take a time of access of a first user to the satellite as a starting time of a first switching period, and construct a second information table containing multiple switching periods based on a preset period length and the starting time of the first switching period; based on the latest time of switching of each user contained in the first information table, divide the user identification corresponding to each user into a user list corresponding to each switching period of the second information table; when the starting time of the current switching period is reached, trigger execution of a cross-satellite switching process for each user in the user list corresponding to the current switching period.

18. The network device of claim 17, wherein, The operation of dividing the user identification corresponding to each user into a user list corresponding to each switching period of the second information table based on the latest time of switching of each user contained in the first information table comprises: traverse the latest time of switching of each user contained in the first information table; for each user, if the latest time of switching of the user is within a first target switching period of the second information table, add the user identification of the user to the user list corresponding to the first target switching period; wherein the first target switching period is any one of the switching periods in the second information table.

19. The network device of claim 18, wherein, The processor further reads the computer program in the memory and performs the following operations: traverse each switching period contained in the second information table in descending order of period number; in a case where the number of user identifications in the user list corresponding to a second target switching period is greater than the number of processes of user switching supported by the single satellite in parallel processing, sort the user identifications of each user contained in the second target switching period based on a preset sorting rule to obtain a user sequence; retain the user identifications of the first target number of users in the user sequence, delete the user identifications of subsequent users in the user sequence, and add the deleted user identifications to the user list corresponding to the previous switching period of the second target switching period; wherein the target number is equal to the number of processes of user switching supported by the single satellite in parallel processing.

20. The network device of claim 19, wherein, The preset sorting rule includes at least one of a sorting rule based on service priority and a sorting rule based on the latest time of switching.

21. The network device of claim 20, wherein, The operation of sorting the user identifications of each user contained in the second target switching period based on the preset sorting rule to obtain a user sequence comprises: sort the user identifications of each user contained in the second target switching period in descending order of service priority. If there are users with the same service priority, the users with the same service priority are sorted in a sequence from later to earlier according to the latest time of user switching, to obtain a user sequence.

22. The network device of claim 20, wherein, The sorting of the user identifiers of the users included in the second target switching period according to the preset sorting rule comprises: sorting the user identifiers of the users included in the second target switching period in a sequence from later to earlier according to the latest time of user switching; If there are users with the same latest time of user switching, the users with the same service priority are sorted in a sequence from high to low according to the service priority, to obtain a user sequence.

23. The network device of claim 17, wherein, The processor is further configured to read a computer program in the memory and perform the following operations: If there is a first target user whose latest time of user switching is updated in the first information table, the user identifier of the first target user is deleted from the second information table, or if there is a second target user that is disconnected from the satellite in the first information table, the user identifier of the second target user is deleted from the second information table. If the second information table does not include the user identifier of a third target user that has accessed the satellite, the step of dividing the user identifier of each user into the user list corresponding to each switching period of the second information table according to the latest time of user switching of each user included in the first information table is performed.

24. The network device of claim 17, wherein, The step of triggering the execution of the cross-satellite switching process for the user list corresponding to the current switching period when the start time of the current switching period is reached comprises: When the start time of the current switching period is reached, a user switching request is initiated to one or more adjacent satellites for each user in the user list corresponding to the current switching period; User switching request feedback information of the multiple adjacent satellites is received, and based on the user switching request feedback information, a target satellite for user switching of the user is screened out, and a notification message is sent to the user equipment of the user; The notification message is used to instruct the user equipment to switch from the current satellite to the target satellite.

25. The network device of claim 15, wherein, If the long axis length of the wave position coverage area is greater than the distance threshold value, the processor is further configured to read a computer program in the memory and perform the following operations: Based on the satellite ephemeris and satellite orbit parameters, the moving speed of the subsatellite point of the satellite on the ground is determined; Based on the moving speed, the range parameter in the wave position coverage area, and the satellite service end time, the target time interval in which the satellite service end time corresponding to each user in the wave position coverage area is located is predicted.

26. A computer-readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the steps of the method in any one of claims 1 to 12.

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