A method, system, and medium for high-mobility user location area design for low earth orbit satellite systems

Abstract

The application discloses a low-orbit satellite system high-mobility user position area design method, system and medium, and belongs to the technical field of satellite communication. The method comprises the following steps: calculating the out-of-area time of a user under the current position area radius according to the current speed of the user; setting a periodical updating time; comparing the out-of-area time and the periodical updating time to determine the position updating mode and the position updating times; calculating the moving distance of the user and deducing the number of paging beams according to the time difference between the paging time and the position updating time; calculating the total position management cost according to the position updating times and the number of paging beams; selecting the radius corresponding to the lowest total position management cost as the position area radius under the current speed by setting different position area radii, and then setting different speeds to obtain the optimal position area radius of the user under different speeds. The application can effectively reduce the position updating frequency of the user and the number of paging beams, significantly reduce the total position management cost, and improve the communication performance of the system.

Description

Technical Field

[0001] This invention relates to a design method, system, and medium for highly mobile user location areas in a low-Earth orbit satellite system, belonging to the field of satellite communication technology. Background Technology

[0002] In the field of satellite communications, location management technology, as a key technology for Low Earth Orbit (LED) satellite mobile communication systems, is crucial to the performance of the entire network. Location management includes two aspects: location update and location paging. Location update refers to the user reporting their location information to the system, which then registers and stores it; while location paging refers to the system successfully transmitting the paging message from the calling user to the called user, thus establishing communication between them.

[0003] In theory, an increase in location update overhead will lead to a decrease in system paging overhead. That is, an increase in the number of location updates will give the system more accurate and real-time user location information, thereby reducing the number of beams used for paging when a call arrives, resulting in a reduction in paging overhead. Conversely, less location update overhead will lead to an increase in system paging overhead. That is, when the number of location updates decreases, the location registration overhead decreases, but because the system obtains less real-time user location information, it will need to increase the paging area, thus increasing paging overhead.

[0004] Currently, traditional location zone design methods only perform location updates when crossing zones; that is, a location update is only performed when the mobile terminal is actually moving and has moved to another location zone. This mainly falls into two categories: location zones based on satellite coverage, where LEO satellites move very quickly, resulting in frequent user location updates; and location zones based on gateway station coverage, where paging requires paging across all satellites and beams connected to the gateway station, leading to significant paging overhead. Therefore, ensuring a good user experience and satellite network system performance, reducing frequent database accesses, and minimizing signaling overhead for mobility management within the network are particularly important. Summary of the Invention

[0005] The purpose of this invention is to provide a design method, system, and medium for the location area of ​​highly mobile users in a low-Earth orbit satellite system. The aim is to reduce the total location management overhead and improve the overall system performance by lowering the location update frequency and paging beam number of highly mobile users.

[0006] To solve the above-mentioned technical problems, the present invention is implemented using the following technical solution:

[0007] On one hand, the present invention provides a method for designing highly mobile user location areas for low-Earth orbit satellite systems, comprising:

[0008] Calculate the user's exit time within the radius of their current location area based on their current speed;

[0009] Based on the paging arrival interval of the system to the user, a periodic update time is set that is less than the paging arrival interval but greater than half of the paging arrival interval;

[0010] By comparing the out-of-area time and the periodic update time, the user's location update method is determined, and the number of times the user updates their location within the system service time is counted.

[0011] Calculate the distance the user traveled within the time difference between the paging time and the location update time;

[0012] Based on the movement distance and the paging beam radius corresponding to the location area, the probability of the user crossing the beam is determined, and then the number of paging beams is calculated based on the probability of the user crossing the beam.

[0013] The total location management overhead is calculated based on the number of location updates and the number of paging beams within the current location area radius.

[0014] By setting different location zone radii, the location zone radius corresponding to the lowest total location management cost is selected as the user's location zone radius at the current speed;

[0015] By setting different speeds, the optimal position radius for the user at different speeds can be obtained.

[0016] In the method proposed in this invention, highly mobile users at different speeds statistically calculate the location update frequency and paging beam count under different location zone radii to determine the optimal location zone radius corresponding to the lowest location management overhead for the user at different operating speeds. Based on the speed-radius relationship obtained in the design method, the system adaptively and dynamically changes the radius of the current location zone when the speed of the highly mobile user changes, thus obtaining the optimal location zone radius for the current speed to ensure the lowest possible total location management overhead.

[0017] Optionally, the step of calculating the user's exit time within the radius of the current location area based on the user's current speed is expressed as:

[0018]

[0019] Among them, t c (i) represents the user's exit time within the radius of the i-th location area, v represents the user's speed, and r d (i) represents the radius of the i-th location region, N r It is represented as a set of radius distributions.

[0020] Optionally, the periodic update time is expressed as:

[0021]

[0022] Among them, t rf Represented as the periodic update time, t p This indicates the paging arrival interval.

[0023] Optionally, the step of determining the user's location update method by comparing the outgoing time and the periodic update time includes:

[0024] If the exit time t c (i) If the update time is faster than the periodic update time trf, then the user's location update method is an active out-of-area location update method; if the out-of-area time t c (i) If the location update is slower than the periodic update time trf, then the user's location update method is a passive periodic location update method.

[0025] Optionally, the step of calculating the user's travel distance within the time difference between the paging time and the location update time is expressed as:

[0026] t d =t pck -t lck

[0027] d = v·t d

[0028] Among them, t d Represented as the time difference between the paging time and the location update time, t pck Indicates the paging time, t lck d represents the location update time, d represents the distance the user moves under the time difference, and v represents the user's speed.

[0029] Optionally, if a user is located at a point x away from the center of the paging beam after a location update, the probability of the user crossing the beam is determined based on the movement distance and the paging beam radius corresponding to the location area, expressed as:

[0030]

[0031] If 0 ≤ d ≤ R, the probability that the user crosses the paging beam is expressed as:

[0032]

[0033] If 0 ≤ d ≤ 2R, the probability that the user crosses the paging beam is expressed as:

[0034]

[0035] Let the parameter ξ = d / R represent the user's mobility, and the probability that the user crosses the paging beam is expressed as:

[0036]

[0037] Among them, P c Let R represent the probability that a user crosses the paging beam, R represent the paging beam radius, and x represent the distance between the user's geographical location and the center of the paging beam after the location update.

[0038] Furthermore, the paging beam number is calculated based on the probability that the user crosses the beam, and is expressed as:

[0039]

[0040] Where, N b This is represented as the paging beam number.

[0041] Optionally, the calculation of the total location management cost based on the number of location updates and the average number of paging beams within the current location area radius is expressed as:

[0042] C = N u ·c u +N b ·c p

[0043] Where C represents the total cost of location management, and N... u N represents the number of position updates. b c represents the number of paging beams. u c represents the cost of a single position update. p This represents the cost per paging session.

[0044] Secondly, the present invention provides a communication system suitable for a highly mobile user location area design method, comprising:

[0045] M satellites with signaling processing capabilities, where M≥1;

[0046] Highly mobile user terminals with positioning capabilities;

[0047] There are N ground gateway stations, each of which is connected to only one satellite at any given time. The ground gateway stations are connected to each other via wired links, where N≥1.

[0048] A network control center is established, and the location management database is located in the control center. All ground gateway stations are connected to the control center via wired links. The signaling for location updates and location paging is sent to the control center for processing.

[0049] Thirdly, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the steps of the high mobility user location area design method as described in the first aspect.

[0050] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0051] (1) The innovative addition of the periodic update mechanism, by taking into account the impact of the paging arrival interval, makes the present invention increase the number of location updates by a small amount compared with the prior art, improves the timeliness of location, ensures the accuracy of paging to a certain extent, and keeps the number of paging beams at a low level. The overhead of location update and location paging is significantly balanced.

[0052] (2) The present invention adopts a single paging method. By using the time difference between the user's paging time and the user's own update time, the relative probability of the user crossing the beam is cleverly derived, and then the paging beam number is calculated in a comprehensive manner. Attached Figure Description

[0053] Figure 1 This is a schematic diagram illustrating the probability that a user of this invention will move outside the beam within a certain time difference.

[0054] Figure 2 This is a schematic diagram of the framework of one embodiment of the method of the present invention;

[0055] Figure 3 This is a schematic diagram illustrating the relationship between the radius and overhead for a user at a fixed speed in the method of this invention;

[0056] Figure 4 This is a schematic diagram illustrating the relationship between the radius of the optimal position area for the user at different speeds and the radius of the optimal position area corresponding to different speeds in the method of this invention;

[0057] Figure 5 This is a schematic diagram comparing the number of position updates in this invention with traditional methods;

[0058] Figure 6 This is a schematic diagram showing the number of paging beams in comparison with traditional methods according to the present invention;

[0059] Figure 7 This diagram illustrates the total overhead of location management in comparison with traditional methods. Detailed Implementation

[0060] The technical concept of this invention is as follows: When a mobile user leaves the original Location Area (LA) and enters a new LA, a location update operation is required to mark its position in the network. When a call needs to be delivered to the mobile user, the network performs location paging to determine the mobile user's accurate location. Existing static location areas remain unchanged after their radius is set. The system under the design method proposed in this invention dynamically changes the radius of the location area based on the obtained relationship between the radius and speed, as the speed of highly mobile users changes, thereby reducing the overall overhead of location management and demonstrating strong targeting capabilities.

[0061] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0062] Example 1

[0063] This embodiment introduces a method for designing highly mobile user location areas for low-Earth orbit satellite systems, such as... Figure 2 As shown, it includes the following steps:

[0064] Calculate the user's exit time within the radius of their current location area based on their current speed;

[0065] Based on the paging arrival interval of the system to the user, a periodic update time is set that is less than the paging arrival interval but greater than half of the paging arrival interval;

[0066] By comparing the out-of-area time and the periodic update time, the user's location update method is determined, and the number of times the user updates their location within the system service time is counted.

[0067] Calculate the distance the user traveled within the time difference between the paging time and the location update time;

[0068] Based on the movement distance and the paging beam radius corresponding to the location area, the probability of the user crossing the beam is determined, and then the number of paging beams is calculated based on the probability of the user crossing the beam.

[0069] The total location management overhead is calculated based on the number of location updates and the number of paging beams within the current location area radius.

[0070] By setting different location zone radii, the location zone radius corresponding to the lowest total location management cost is selected as the user's location zone radius at the current speed;

[0071] By setting different speeds, the optimal position radius for the user at different speeds can be obtained.

[0072] In practical application, the network control center acquires the user's location and speed information, sets a location area radius based on this information, and then the timer starts counting accordingly. During the timing process, this invention innovatively adds a periodic update time based on the system service time and the paging arrival interval of the system to the user. This periodic update time is compared with the outbound time calculated by conventional methods, and the method that consumes less time is selected as the user's primary update method, thereby determining the number of updates within the service time. At the same time, the number of paging beams is determined successively based on the time difference between the paging time and the update time and the paging beam radius. Finally, by combining the update overhead and the paging overhead, the total location management overhead at the current speed can be obtained.

[0073] Furthermore, by setting different location zone radii and repeating the above steps to determine the total location management cost, the optimal location zone radius corresponding to the lowest location management cost at the current speed can be obtained. Furthermore, by changing the user's running speed and repeating the above steps to determine the optimal radius, the optimal location zone radius corresponding to different speeds can be obtained.

[0074] Example 2

[0075] refer to Figure 1 and Figure 2 Given a user speed of 600 km / h and a current location radius of 400 km, the process for determining the corresponding update frequency and paging beam count is as follows:

[0076] Assuming a highly mobile user is moving in a straight line at the center of the location area, calculate the exit time within the current location area radius based on the user's speed:

[0077]

[0078] Among them, t c (i) represents the user's exit time within the radius of the i-th location area, v represents the user's speed, and N r This is represented as a set of radius distributions. Based on the current speed and the radius of the location area, it is known that the exit time for highly mobile users is 40 minutes.

[0079] To prevent highly mobile users from going for extended periods without updates and thus remaining unaware of their terminal location, the update rate should not be less than the call arrival rate. Therefore, a periodic update time is set to be less than the paging arrival interval but greater than half of the paging arrival interval.

[0080] The call arrival rate is expressed as:

[0081]

[0082] In the formula, Np Let t be the average call arrival rate, T be the system service time, and t be the call arrival rate. p Let T be the paging arrival interval. Assuming the service time T is 2 hours and the paging arrival interval is 1 hour, then the average call arrival rate is 2%.

[0083] The periodic update time corresponding to the update rate is expressed as:

[0084]

[0085] Among them, t rf Represented as the periodic update time, t p This represents the paging arrival interval. Specifically, the periodic update time can be set between 30 minutes and 1 hour, with 45 minutes being a suitable value.

[0086] Furthermore, by comparing the exit time t c (i) and the speed of the periodic update time (trf) to select the user's location update method;

[0087] The step of determining the user's location update method by comparing the out-of-area time and the periodic update time includes:

[0088] If the exit time t c (i) If the update time is faster than the periodic update time trf, then the user's location update method is an active out-of-area location update method; if the out-of-area time t c (i) If the update time is slower than the periodic update time trf, the user's location update method is a passive periodic location update method. Since the out-of-area time is 40 minutes and the periodic update time is 45 minutes, the location update method in this embodiment adopts an active out-of-area location update method. It waits for the user to move out of the location area, initiates an update, resets the timer, and then counts the number of updates during the system service time.

[0089] The method for calculating the user's travel distance based on the time difference between the paging time and the location update time is expressed as follows:

[0090] t d =t pck -t lck

[0091] d = v·t d

[0092] Among them, t d Represented as the time difference between the paging time and the location update time, t pck Indicates the paging time, t lck d represents the location update time, d represents the distance the user moves under the time difference, and v represents the user's speed.

[0093] After a location update, a user is located at a point x distance from the center of the paging beam. The probability of the user crossing the beam is determined based on the movement distance and the radius of the paging beam corresponding to the location area, expressed as:

[0094]

[0095] Figure 1 The diagrams show the probability of a user crossing the beam when 0≤d≤R and 0≤d≤2R, respectively.

[0096] Specifically, such as Figure 1 As shown in (a), if 0 ≤ d ≤ R, the probability that the user crosses the paging beam is expressed as:

[0097]

[0098] like Figure 1 As shown in (b), if 0 ≤ d ≤ 2R, the probability that the user crosses the paging beam is expressed as:

[0099]

[0100] Let the parameter ξ = d / R represent the user's mobility, and the probability that the user crosses the paging beam is expressed as:

[0101]

[0102] Among them, P c Let R represent the probability that a user crosses the paging beam, R represent the paging beam radius, and x represent the distance between the user's geographical location and the center of the paging beam after the location update.

[0103] Furthermore, the calculation of the paging beam number based on the probability of a user crossing a beam is expressed as follows:

[0104]

[0105] Where, N b This is represented as the paging beam number.

[0106] It is worth noting that if the high-speed terminal has not left the current beam, paging will only be performed on the current beam; if it has left, paging will be performed on all beams within the location area.

[0107] The calculation of the total location management cost based on the number of location updates and the average number of paging beams within the current location area radius is expressed as follows:

[0108] C = N u ·c u +Nb ·c p

[0109] Where C represents the total cost of location management, and N... u N represents the number of position updates. b c represents the number of paging beams. u c represents the cost of a single position update. p This represents the cost per paging session.

[0110] This embodiment sets different location area radii and selects the cost C based on the total location management cost corresponding to each location area radius. min The lowest radius is used as the position zone radius at the current user speed; for speed distributions in the range v0 to v... j For highly mobile users, the corresponding optimal location area radius r0 to r can be further obtained. j and the corresponding minimum location management total cost C min .

[0111] Example 3

[0112] This embodiment uses three different location area design methods as experimental objects: location area based on LEO coverage, location area based on gateway station coverage, and dynamic location area based on user speed in this invention. The system service time is set to 2 hours, and the average call interval is once per hour. The number of location updates, paging beam counts, and total location management overhead are statistically analyzed for each location area with a call arrival rate of 2. (Refer to...) Figures 3 to 7 The following details the implementation process of the simulation experiment.

[0113] I. Experimental Scenario

[0114] During the operation of low-Earth orbit satellites, the area beneath the satellite is not static, necessitating frequent switching between the satellite and ground-based user terminals and stations. Typically, at an orbital altitude of 1000 kilometers, a single connection between the satellite and a ground station lasts only about 10 minutes. To maintain network connectivity, end users need to frequently switch between different serving satellites, and the satellite also needs to frequently switch between different ground stations.

[0115] In this embodiment, the LEO satellite altitude is set to 550km (the orbital altitude of low-Earth orbit satellites is generally between 200 and 2000km), the coverage area of ​​each satellite is 450km in radius, each satellite includes 7 beams with a beam radius R of 150km, and the average coverage time of each satellite to the ground is 6 minutes; the coverage radius of the gateway station is 1168km; the overhead for a single location update is 1108 bits, and the overhead for a single paging is 168 bits.

[0116] II. Experiment Content

[0117] First, such as Figure 3 As shown, for a highly mobile user with a speed of 600 km / h, such as an airplane or high-speed train, the total cost of location management first decreases and then increases as the radius of the corresponding location area increases.

[0118] Specifically, when the radius is small, highly mobile users can easily move outside the corresponding location area, resulting in excessively frequent location updates and a large amount of unnecessary overhead. As the radius increases, the frequency of highly mobile users leaving the area decreases accordingly, the number of location updates decreases, and the overhead is reduced accordingly. However, as the radius further increases, the corresponding location area contains more beams. If a paging request cannot be made in the beam of the most recent location update, it will paging other beams within the range, thus increasing the paging overhead and significantly raising the total location management overhead.

[0119] Therefore, the radius of the corresponding location area is not necessarily better the larger it is, but there exists an optimal location area radius that minimizes the total cost of location management.

[0120] Figure 4 The figure shows the optimal location zone radius for highly mobile users at different speeds, which is approximately proportional to the call arrival rate of 2. The optimal location zone radius generally increases with user speed, where, combined with... Figure 3 As shown, when the speed of a highly mobile user is 600 km / h, the corresponding optimal location zone radius is 560 km. That is, at this speed and location zone radius, the total location management overhead of the system is minimized.

[0121] Secondly, the following details the location update, paging beam count, and total location management overhead under the three different location area design methods:

[0122] (1) Number of location updates

[0123] like Figure 5 As shown, with the increase in the speed of highly mobile users, the number of location updates under each location area design method increases. The number of location updates in the dynamic location area design method proposed in this invention is significantly reduced compared to the location area design method based on satellite coverage, but slightly higher than the location area design method based on gateway station coverage.

[0124] (2) Number of paging beams

[0125] In theory, location paging will attempt to page the beam containing the most recent location update of a highly mobile user. If the user cannot be paged, a secondary paging will be performed on surrounding beams. For highly mobile users, as their speed increases, the distance they travel in a short period also increases, significantly raising the probability of them crossing beams. If the interval between the paging time and the location update time is long, it will lead to a decrease in paging accuracy, resulting in multiple paging attempts across multiple beams.

[0126] For details, please refer to [link / reference]. Figure 6 As shown, the location area based on LEO coverage has the fewest paging beams because its location updates are frequent, making it easier to find users during paging and resulting in the best accuracy. The location area based on gateway station coverage has the most paging beams because its location updates are infrequent and its location timeliness is poor, causing users to be paged in multiple beams during paging. The dynamic location area based on user speed provided in this invention, due to the addition of a periodic update mechanism, not only increases the number of location updates slightly to obtain better location timeliness and ensures a certain degree of paging accuracy, but also keeps the overall number of paging beams at a low level.

[0127] It is worth noting that the paging beam fluctuation is due to the influence of the paging arrival time and the location update time. If the time difference between the newly arrived paging and the most recent location update is small, it indicates that the terminal's location change is small, and the paging accuracy is high, and the number of paging beams is also small, and vice versa.

[0128] (3) Total location management cost

[0129] like Figure 7 As shown, location areas based on LEO coverage have higher location management overhead due to the more frequent location updates; while location areas based on gateway station coverage and user speed have significantly lower overall overhead due to fewer updates. Furthermore, location areas based on gateway station coverage have a larger radius and poor timeliness for location updates to highly mobile users, resulting in lower paging accuracy. They often require paging most beams across the entire location area, thus their total location management overhead is higher than that of this invention.

[0130] III. Experimental Conclusions

[0131] In summary, compared with the location areas based on LEO coverage and the location areas based on gateway station coverage in the prior art, the dynamic location area under the design method proposed in this invention can adaptively balance the number of location updates and the overhead of location paging, so as to achieve the best overall performance of the ground orbit satellite system.

[0132] Example 4

[0133] This embodiment provides a communication system suitable for a high-mobility user location area design method, which includes: M satellites with signaling processing capabilities, where M≥1;

[0134] Highly mobile user terminals with positioning capabilities;

[0135] There are N ground gateway stations, each of which is connected to only one satellite at any given time. The ground gateway stations are connected to each other via wired links, where N≥1.

[0136] A network control center is established, and the location management database is located in the control center. All ground gateway stations are connected to the control center via wired links. The signaling for location updates and location paging is sent to the control center for processing.

[0137] The above-described communication system can execute the high-mobility user location area design method described in Embodiment 1, 2, or 3 above. The specific implementation process of the communication system will not be elaborated here.

[0138] Example 5

[0139] This embodiment provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the high-mobility user location area design method as described in Embodiment 1 or 2.

[0140] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0141] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0142] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0143] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0144] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for designing a highly mobile user location area, characterized in that, include: Calculate the user's exit time within the radius of their current location area based on their current speed; Based on the paging arrival interval of the system to the user, a periodic update time is set that is less than the paging arrival interval but greater than half of the paging arrival interval; By comparing the out-of-area time and the periodic update time, the user's location update method is determined, and the number of times the user updates their location within the system service time is counted. Calculate the distance the user traveled within the time difference between the paging time and the location update time; Based on the movement distance and the paging beam radius corresponding to the location area, the probability of the user crossing the beam is determined, and then the number of paging beams is calculated based on the probability of the user crossing the beam. Wherein, set parameters The probability of a user crossing a paging beam represents the user's mobility. ； in, R represents the probability that a user crosses the paging beam, R represents the paging beam radius, and d represents the distance the user moves under the time difference. The paging beam number is calculated based on the probability that the user crosses the beam, and is expressed as: ； in, Indicates the number of paging beams; Indicates the first The radius of each location area; The total location management overhead is calculated based on the number of location updates and the number of paging beams within the current location area radius. By setting different location zone radii, the location zone radius with the lowest total location management cost is selected as the optimal location zone radius for the user at the current speed. By setting different speeds, the optimal position radius for the user at different speeds can be obtained.

2. The high-mobility user location area design method according to claim 1, characterized in that, The calculation of the user's exit time within the radius of the current location area based on the user's current speed is expressed as follows: ； in, Indicates the user's position in the first month. Out-of-area time under the radius of each location area Indicates the user's speed. Indicates the first The radius of each location area, This represents the set of radius distributions.

3. The high-mobility user location area design method according to claim 2, characterized in that, The periodic update time is expressed as: ； in, Indicates the periodic update time. Indicates the paging arrival interval.

4. The high-mobility user location area design method according to claim 3, characterized in that, The step of determining the user's location update method by comparing the out-of-area time and the periodic update time includes: If the exit time Faster than the stated periodic update time In this case, the user's location update method is the active out-of-area location update method; If the exit time Slower than the said periodic update time In this case, the user's location update method is a passive, periodic location update method.

5. The high-mobility user location area design method according to claim 1 or 4, characterized in that, The method for calculating the user's travel distance based on the time difference between the paging time and the location update time is expressed as follows: ； ； in, This represents the time difference between the paging time and the location update time. Indicates the paging time. The location update time is indicated by d, and the distance the user moves under the time difference is indicated by d.

6. The high-mobility user location area design method according to claim 1, characterized in that, The total location management cost is calculated based on the number of location updates and the number of paging beams within the user's current location area radius, and is expressed as follows: ； Where C represents the total cost of location management. Indicates the number of location updates. Indicates the number of paging beams. Indicates the cost of a single location update. This indicates the cost per paging session.

7. A communication system applicable to the high-mobility user location area design method according to any one of claims 1 to 6, characterized in that, include: M satellites with signaling processing capabilities, where M≥1; Highly mobile user terminals with positioning capabilities; There are N ground gateway stations, each of which is connected to only one satellite at any given time. The ground gateway stations are connected to each other via wired links, where N≥1. A network control center is established, and the location management database is located in the control center. All ground gateway stations are connected to the control center via wired links. The signaling for location updates and location paging is sent to the control center for processing.

8. A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the steps of the high mobility user location area design method as described in any one of claims 1-6.

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