Method for managing switching channel resources in large-scale satellite networks based on traffic forecasts

Abstract

The present application belongs to the technical field of satellite communication, and particularly relates to a switching channel resource management method, which mainly solves the problem of high switching failure rate or low new call user access success rate caused by unreasonable switching channel reservation in the prior art. The implementation scheme is as follows: in the face of the staring coverage mode, the global ground surface area is divided into several position areas according to the longitude and latitude; the number of new call users in each position area in a future period of time is predicted according to the user behavior data of each position area at historical time and the user behavior data at the current time; the user access success rate, the user switching success rate and the user average weighted satisfaction are set as the utility function, and the optimal channel resource threshold of all low-orbit satellites and the optimal switching channel of the switching user are periodically calculated. The present application improves the user access success rate and the user switching success rate, reduces the calculation amount of user access and switching, improves the user service satisfaction and the channel resource utilization rate, and can be used in the satellite communication network.

Description

Technical Field

[0001] This invention belongs to the field of communication technology, and further relates to a method for managing channel resources in large-scale satellite networks, which can be used in satellite communication networks. Background Technology

[0002] Large-scale low-Earth orbit (LEO) satellite networks are a key technology for the next generation of internet revolution, and wireless satellite communication is considered the most promising communication method for achieving coverage across land, sea, and air. LEO satellites, with their lower orbital altitude, have lower communication latency and higher data transmission rates. The continuous development of satellite communication technology brings more possibilities to the future space-based information industry. While 5G / 6G networks feature high transmission rates and low latency, their base station density is far higher than traditional 3G / 4G networks, resulting in correspondingly higher costs for comprehensive deployment and limiting coverage to urban areas in the short term. In contrast, satellite communication can quickly and conveniently deliver multimedia broadcasting services in complex environments, a feature well-suited for handling emergencies such as geological disasters. In remote mountainous areas where terrestrial communication networks cannot be properly established, large-scale satellite communication systems can provide normal communication services. Furthermore, they can provide excellent communication services for highly mobile users. Based on these advantages, large-scale satellite communication systems can effectively supplement terrestrial communication systems.

[0003] In large-scale satellite communication networks, channel resources, i.e., bandwidth resources, are extremely precious. With the increasing importance of large-scale satellite networks and the growing number of satellite terminals (such as mobile phones, mobile PCs, vehicle-mounted terminals, shipborne terminals, airborne terminals, and ground control terminals), the volume and types of services requiring transmission are increasing. Therefore, it is essential to rationally manage limited channel resources and improve their utilization rate. Looking towards the future development of integrated space-ground networks, further research is urgently needed on how to design efficient channel resource management protocols for large-scale satellite networks based on user groups in the same location area.

[0004] Patent application number 201510156025.5 discloses a multi-layer satellite network channel resource management method. This method first categorizes users into different priorities based on service type and user type. By predicting the traffic volume of new calling users allowed to access a cell within a certain period, it provides decision support for different users accessing the multi-layer satellite network. Then, based on a comparison of the bandwidth required by users, it allocates channel resources to the multi-layer satellite network. Next, it uses game theory to determine the type and number of users to be downgraded, and by improving the upgrade / downgrade model, it determines the specific downgrade method for downgraded users and their access after downgrade, making the downgrade process more reasonable and transparent. However, this method involves executing a channel allocation algorithm every time a user accesses the network, resulting in complex satellite signaling interactions and a large computational load, which is detrimental to improving overall system performance. Furthermore, because this method uses fixed resources for satellite channel access and switching, it cannot be dynamically adjusted, which can easily lead to channel resource waste in high-user scenarios, resulting in users being within satellite coverage areas but unable to obtain channel resources to access the satellite network.

[0005] In their paper "Channel Allocation Strategy for Low-Earth Orbit Satellite Communication," Liu Jun and Li Guojia proposed a channel allocation method based on traffic volume, addressing the characteristics of low-Earth orbit satellite communication: low orbital altitude, high movement speed, frequent handover, and the increasingly diverse service and user types. Under high traffic volume, they employed an adaptive channel reservation strategy based on a differential evolution algorithm to dynamically adjust the number of reserved channels, ensuring access for high-priority users. Under low traffic volume, they proposed a non-reserved channel allocation scheme to meet the ideal bandwidth requirements of high-priority users. When all cell channels were occupied, they proposed an enhanced queuing strategy, adding temporarily unavailable users to a queue and allowing them to access the network sequentially based on their overall priority. However, this method cannot guarantee the access success rate for low-priority users, and because it does not consider whether reserved channels can meet the service rate requirements of high-priority users, it is detrimental to improving user service satisfaction. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of the existing technology by proposing a large-scale satellite network handover channel resource management method based on traffic volume prediction. This method simplifies the complexity of satellite signaling interaction in satellite channel allocation, reduces the computational load for user access and handover, improves the success rate of user access and handover, and meets the needs of user services.

[0007] The key technologies for achieving the objectives of this invention are: by using medium-Earth orbit satellites and ground base stations as the main entities for channel allocation, directly obtaining channel usage information of low-Earth orbit satellite nodes, thus simplifying the complexity of satellite signaling interaction in satellite channel allocation; by allocating channels to all users in a location area as a user group, reducing the computational load for user access and handover; by predicting the number of new calling users and satellite trajectory information in each location area, obtaining the number of new calling users and handover users, and dynamically adjusting the number of reserved handover channels, thereby improving the success rate of user access and handover; and by reserving the optimal handover channel based on user service needs and handover time, thus meeting user service requirements.

[0008] The implementation steps of the present invention based on the above key technologies include the following:

[0009] (1) Set target value Set the optimal satellite channel resource threshold The Earth's surface is divided according to its latitude and longitude. Location area : , ;

[0010] (2) Traverse each location area Based on its historical user behavior data, adopt Model predicts the future Location area within a time period The number of new calling users;

[0011] (3) Generate a satellite-location area association table, and obtain the current gaze location area based on the association table. Low-orbit satellite collection : , , The current gaze location area The total number of satellites;

[0012] (4) Set the channel resource threshold set , For the first The threshold of available channel resources for a low-Earth orbit satellite. This represents the total number of satellite channel resources.

[0013] (5) Randomly connect the new calling users predicted in step (2) to the low-Earth orbit satellite set. Calculate the user access success rate for any available access channel. ;

[0014] (6) Predict the set of users to be switched at the next time step based on the satellite-location area association table. and available switching channel resources of the system Calculate the user switching success rate ,in , , To switch the number of users for the next moment;

[0015] (7) Obtain the gaze location area at the next moment based on the satellite-location area association table. Low-orbit satellite collection Predict each switching user Random access to a low-Earth orbit satellite ensemble For any available handover channel, update the reserved information table for the handover channel and calculate the handover user. Weighted satisfaction of accessing this channel and resource utilization rate ;

[0016] (8) Sum the weighted satisfaction scores of all switching users and take the average. ;

[0017] (9) Iterate through each user switching step (6). Determine the available satellite set Is there an idle switching channel? If yes, proceed to step (10); otherwise, proceed to step (11).

[0018] (10) Select a set of low-Earth orbit satellites China has the most satellites with the most available switching channels. Calculate user switching Access satellite Maximum weighted satisfaction of all available switching channels and maximum resource utilization and adjust the user switching Update the reserved information table for the service channel and switch channels:

[0019] (11) Switch users Randomly select a set of low-Earth orbit satellites The next low-orbit satellite And randomly select the service users of the satellite. Then switch users With service users The channels in which they are located are swapped, and the reserved information table for the switching channels is updated;

[0020] (12) Based on user access success rate User switching success rate and switching user average weighted satisfaction Calculate the optimization objective value and compare it with the set target value. Comparison:

[0021] like Then the optimal satellite channel resource threshold will be set. Updated to the number Available channel resource threshold for a low-Earth orbit satellite It outputs the optimal satellite channel resource threshold. and a reservation information table for switching channels;

[0022] Otherwise, the optimal satellite channel resource threshold will be used. Updated to Output the optimal satellite channel resource threshold .

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] Firstly, this invention divides the global surface region into several location zones based on latitude and longitude, establishes an ARIMA model, and predicts the number of new calling users in the future based on the trend of user behavior data in each location zone at historical moments, thereby improving the accuracy of the prediction of the number of new calling users.

[0025] Secondly, the present invention sets users located in the same location area as a user group and allocates channels according to the user group, thereby reducing the amount of computation required for user access and handover.

[0026] Third, this invention sets user access success rate, user handover success rate, and average weighted user satisfaction as optimization targets, and periodically adjusts the low-Earth orbit satellite channel resource threshold, which can improve user access success rate and handover success rate.

[0027] Fourth, this invention reserves handover channels based on user service needs and handover time, thereby improving user service satisfaction and system channel resource utilization. Attached Figure Description

[0028] Figure 1 This is a flowchart illustrating the implementation of the present invention;

[0029] Figure 2 This is a location area division diagram in this invention;

[0030] Figure 3 This is a schematic diagram of satellite channel resource allocation in this invention. Detailed Implementation

[0031] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0032] Reference Figure 1This example demonstrates implementation scenarios including low-Earth orbit satellites, users, medium-Earth orbit satellites, and ground stations. The implementation steps are as follows:

[0033] Step 1: Divide the global Earth's surface into several location zones and predict the future location of each zone. The number of new users making calls within a given time period.

[0034] 1.1) Based on global surface latitude and longitude information and global user business distribution information, the global surface area is divided into... Location area : ,in For the first Each location area The location area division is as follows: Figure 2 As shown, the location area is divided in this example. For example, but not limited to 756;

[0035] 1.2) Position area The access time and call duration of new calling users at each moment are stored in medium-Earth orbit satellites and ground stations to obtain location areas. User behavior data at historical moments ;

[0036] 1.3) Based on location area By taking the difference between the access times of adjacent new callers from historical user behavior data, a sequence of arrival time intervals for new callers is obtained. This sequence of arrival time intervals is then assigned to the differential ensemble moving average autoregressive model. The time series was subjected to stationarity verification, and the differenced integrated moving average autoregressive model was determined by using the autocorrelation function plot and partial autocorrelation function plot of the time series. Model parameters;

[0037] 1.4) According to Model parameters are used to establish a difference-integrated moving average autoregressive model. , location area User behavior data at historical moments and predicted time Input into the differential integrated moving average autoregressive model In Method: Differential Integrated Moving Average Autoregressive Model Based on historical data The trend is shaping the future. The number of new callers at any given moment.

[0038] Step 2: Connect the predicted new callers to the low-Earth orbit satellite array. In the process of calculating the user access success rate .

[0039] 2.1) Use STK simulation software to obtain the trajectory file of the low-Earth orbit satellite. Based on the trajectory file, obtain the latitude, longitude, and altitude information of the low-Earth orbit satellite at each time. Use the shortest distance algorithm to calculate the distance between the low-Earth orbit satellite and each location area at each time. :

[0040] ;

[0041] in, This is the latitude of the low-orbit satellite. This is the longitude of the low-orbit satellite. This is the altitude of the low-orbit satellite. The latitude of the center point of the location area. The longitude of the center point of the location area;

[0042] A satellite-location area association table is constructed using the location area closest to the low-Earth orbit satellite at each time point, as shown in Table 1.

[0043] Table 1 Satellite-Location Area Association Table

[0044]

[0045] 2.2) Set up a low-Earth orbit satellite array Iterate through all low-Earth orbit (LEO) satellites and query the satellite-location area association table to find the location area that the LEO satellite is currently viewing at the moment:

[0046] If the low-orbit satellite is currently staring at the location area Then place it into a low-orbit satellite set. middle, ,in For the first A low-orbit satellite, , The current gaze location area The total number of satellites;

[0047] 2.3) Set the channel resource threshold set , For the first The threshold of available channel resources for a low-Earth orbit satellite. The total number of satellite channel resources, and the channel resource threshold division as follows: Figure 3 As shown;

[0048] 2.4) Randomly connect the predicted new calling users to a set of low-Earth orbit satellites. Calculate the user access success rate for any available access channel. :

[0049] ;

[0050] in To successfully connect to the number of users, This represents the number of users requesting access.

[0051] Step 3: Obtain the set of users switching at the next moment. and available switching channel resources of the system Calculate the user switching success rate .

[0052] 3.1) Set the set of users to be switched at the next moment. Query the current gaze location area in the satellite-location area association table. The low-orbit satellite is identified, and its position region at the next moment is queried from the correlation table:

[0053] If the location area that the low-orbit satellite is looking at at the next moment is not... Then, the users serving that satellite will be added to the switchover user set for the next moment. middle,

[0054] , , To switch the number of users for the next moment;

[0055] Otherwise, add the number of idle switching channels of that satellite to the available switching channel resources. middle;

[0056] 3.2) Calculate the user handover success rate :

[0057] ;

[0058] in To the number of users who successfully switched over, The number of users requested to be switched.

[0059] Step 4, switch users Randomly accessed low-Earth orbit satellite ensemble at the next moment For any available handover channel, update the reserved information table for the handover channel and calculate the handover user. Weighted satisfaction of accessing this channel and resource utilization rate .

[0060] 4.1) Set the set of low-Earth orbit satellites for the next time step Iterate through all low-Earth orbit (LEO) satellites and query the satellite-position area association table for the position area that the LEO satellite will be looking at at the next moment:

[0061] If the low-orbit satellite is in the gaze area at the next moment... Then it will be placed into the low-orbit satellite set at the next moment. If the traversal fails, continue iterating through the next low-Earth orbit satellite until the traversal is complete;

[0062] 4.2) Based on the user switching speed requirements Calculate user switching weight :

[0063]

[0064] in, To switch the number of users;

[0065] 4.3) Switch users Randomly accessed low-Earth orbit satellite ensemble at the next moment Any available switching channel will switch users. The selected handover channel information is updated to the reserved information table for the handover channel, as shown in Table 2:

[0066] Table 2. Reservation Information for Channel Switching

[0067]

[0068] 4.4) Calculate the user switching process Weighted satisfaction of accessing this channel and resource utilization rate :

[0069] ,

[0070] ,

[0071] in, The transmission rate provided for the current channel.

[0072] Step 5, Update and switch users Selected switching channel.

[0073] 5.1) Determine the set of low-Earth orbit satellites at the next moment. Is there an idle switching channel?

[0074] If so, proceed to step (5.2).

[0075] Otherwise, proceed to step (5.3);

[0076] 5.2) Select the set of low-Earth orbit satellites for the next time step China has the most satellites with the most available switching channels. Calculate user switching Access satellite Maximum weighted satisfaction of all available switching channels and maximum resource utilization and adjust the user switching Update the reserved information table for the service channel and switch channels:

[0077] 5.2.1) Setting the target satellite Set the initial value for the maximum number of available switching channels. traverse the set of low-orbit satellites at the next moment. For each low-Earth orbit (LEO) satellite, the number of available switching channels for each LEO satellite is obtained based on the LEO satellite channel usage status. Combine it with the set maximum number of available switching channels. Comparison:

[0078] like Then Updated to , target satellite Update to the currently visited low-Earth orbit satellites;

[0079] Otherwise, continue iterating through the next low-Earth orbit satellite until the entire set of low-Earth orbit satellites for the next moment has been traversed. All low-Earth orbit satellites;

[0080] 5.2.2) Set the initial value of the maximum weighted satisfaction level. Set the initial value of the target channel. Set up low-orbit satellites Available switching channel set ,in For the first One available switching channel , For low-orbit satellites The number of available switching channels;

[0081] Traverse each available switching channel Switch users Access its weighted satisfaction With the set maximum weighted satisfaction Comparison:

[0082] like Then the maximum weighted satisfaction rate will be calculated. Updated to ,Will Updated to ;

[0083] Otherwise, continue iterating through the next available switching channel until all available switching channels have been traversed;

[0084] 5.2.3) Set the initial value for maximum resource utilization. Calculate user switching Access target channel resource utilization rate :

[0085] ;

[0086] in, For the target channel Provided transmission rate To switch users The rate requirement;

[0087] 5.2.4) will Assign a value to the maximum resource utilization rate Then, the maximum weighted satisfaction rate and maximum resource utilization Respectively with weighted satisfaction and resource utilization rate Comparison:

[0088] like Then As a user switch The service channel is updated, and the reserved information table for switching channels is updated.

[0089] Otherwise, keep switching users. Initial access selection;

[0090] 5.3) Randomly select the set of low-Earth orbit satellites for the next time step. The next low-orbit satellite And randomly select the service users of the satellite. Then switch users With service users The channels in which they are located are swapped, and the reserved information table for the switching channels is updated.

[0091] Step 6, based on user access success rate User switching success rate and switching user average weighted satisfaction Calculate the optimization objective value and update the set target value. .

[0092] 6.1) Sum the weighted satisfaction levels of all switching users and take the average. :

[0093] ;

[0094] in, To switch users Weighted satisfaction To switch the number of users;

[0095] 6.2) Calculate the optimization objective value :

[0096] ;

[0097] in, To improve user access success rate To improve the user's switching success rate;

[0098] 6.3) Optimize the target value With the set final optimization goal Comparison:

[0099] like Then the optimal satellite channel resource threshold set will be... Updated to channel resource threshold set Update the reservation information table of the optimal switching channel to the reservation information table of the current switching channel, and let... Update;

[0100] 6.4) Continue executing 2.3) after setting the channel resource threshold set. Output the optimal set of satellite channel resource thresholds for all possible scenarios. And a reservation information table for the optimal switching channel.

[0101] This completes the resource management for large-scale satellite network channel switching.

[0102] The above description is merely a specific example of the present invention and does not constitute any limitation on the present invention. Obviously, those skilled in the art, after understanding the content and principles of the present invention, may make various modifications and changes in form and details without departing from the principles and structure of the present invention. However, these modifications and changes based on the ideas of the present invention are still within the scope of protection of the claims of the present invention.

[0103] It should be noted that the step numbers in the specification and claims of this invention are only for the purpose of clearly describing the embodiments of this invention and facilitating understanding, and their order is not limited.

Claims

1. A method for managing switching channel resources in a large-scale satellite network based on traffic prediction, characterized in that, Comprising the following steps: (1) setting a target value , setting a set of optimal satellite channel resource threshold values , dividing a global land surface region into position areas according to the latitude and longitude thereof : , ; (2) traversing each location area , according to the historical time user behavior data, using model to predict the future time location area new call user number; (3) generating a satellite-position area association table and obtaining the current gaze position area according to the association table of the low-orbit satellite set : , , is the total number of satellites of the current gaze position area . (4) set a channel resource threshold set , for the first optional channel resource threshold of the low earth orbit satellite, total number of satellite channel resources; (5) Randomly accessing the predicted new call user in step (2) to any one of the available access channels in the low-orbit satellite set, and calculating the user access success rate ;​ (6) predicting the next time switching user set according to the satellite-position area association table and system available switching channel resource , calculating user switching success rate wherein , , is the next time switching user number; (7) Obtain the gaze location area at the next moment based on the satellite-location area association table. Low-orbit satellite collection Predict each switching user Random access to a low-Earth orbit satellite ensemble For any available handover channel, update the reserved information table for the handover channel and calculate the handover user. Weighted satisfaction of accessing this channel and resource utilization rate ; (8) Sum all the weighted satisfaction of the switched users and take the average ; (9) traversing each handoff user in step (6) to determine if the optional satellite set has a free handoff channel: if yes, then perform step (10), otherwise perform step (11); (10) selecting a low earth orbit satellite set the satellite with the most available handoff channels calculating handoff users accessing a satellite the maximum weighted satisfaction of all available handoff channels and the maximum resource utilization and adjusting the service channel of the handoff user updating the reservation information table of the handoff channel: (11) switching user randomly selecting a low-orbit satellite set the next low-orbit satellite and randomly selecting a service user of the satellite then exchanging the switching user with the service user on the channel where the service user is located, and updating the reservation information table of the switching channel; (12) According to the user access success rate and the user handover success rate and the average weighted satisfaction of the handover users to calculate the optimization target value and compare it with the set target value . If , the optimal satellite channel resource threshold set is updated to the channel resource threshold set , the reservation information table of the optimal switching channel is updated to the reservation information table of the current switching channel, and is updated; Continuing execution (4), when the channel resource threshold set is set The optimal satellite channel resource threshold set and the reservation information table of the optimal switching channel are outputted. The optimal satellite channel resource threshold set and the reservation information table of the optimal switching channel are outputted.

2. The method of claim 1, wherein, In step (2), the model predicts the number of new call users in the location area in the future time period according to the historical user behavior data of the time period The implementation steps include the following:​​ 2a) storing the access time and the duration of the call of the new call user at each time instant, obtaining the position area the access time and the duration of the call of the new call user at each time instant, obtaining the position area the user behavior data at the historical time instant; 2b) according to the location area The user behavior data at the historical moment, the access time difference of the adjacent new call user, the arrival time interval sequence of the new call user, the arrival time interval sequence is assigned to The time sequence of the model, and the stationarity check is carried out, the model parameters are determined through the autocorrelation function graph and the partial autocorrelation function graph of the time sequence ​ 2c) Build a model based on the model parameters , location area User behavior data at historical moments and predicted time Transmitted to In Methods, Models Based on historical data The trend is shaping the future. The number of new callers at any given moment.

3. The method of claim 1, wherein, In step (3), a satellite-positioning area association table is generated, and a current time gaze positioning area is obtained according to the association table of low-orbit satellites The implementation steps include the following: 3a) using STK simulation software to obtain the trajectory file of low-orbit satellite at each time, and using the shortest distance algorithm to calculate the distance between low-orbit satellite and each location area according to the trajectory file of low-orbit satellite, so that the nearest location area is the satellite-location area association table; 3b) iterate over all low earth orbit satellites, query the satellite-position area association table for the position area the low earth orbit satellite is currently staring at, if the low earth orbit satellite is currently staring at a position area , put it into the set of low earth orbit satellites .

4. The method of claim 1, wherein, Step (5) calculates the user access success rate The formula is as follows: ； wherein the number of successfully accessed users, the number of users requesting access.

5. The method of claim 1, wherein, Step (6) predicts the next time switching user set according to the satellite-position area association table and the system available switching channel resource is to query the low-orbit satellite which is gazing at the position area at the current time in the satellite-position area association table and to query the position area which the satellite is gazing at the next time in the association table: If the next position area of the low orbit satellite is not the service user of the satellite is added to the list of users of the satellite. Otherwise, add the number of free handoff channels for this star to the available handoff channel resources in the middle.

6. The method of claim 1, wherein, Step (6) calculates the user handover success rate , The formula is as follows: ； wherein is the number of successful handover users, is the number of handover users requested.

7. The method of claim 1, wherein, Step (7) Acquire the next time's gaze location area according to the satellite-location area association table of the low-orbit satellite set , traverse all low-orbit satellites, and query the location area that the satellite gazes at the next time in the satellite-location area association table: If the low earth orbit satellite is in the next time's gaze position area then put it into the next time's low earth orbit satellite set otherwise, continue to traverse the next low earth orbit satellite until the end of the traversal.

8. The method of claim 1, wherein, Calculating the switching user in step (7) Accessing the channel weighted satisfaction and resource utilization , as follows: ； ； wherein, the transmission rate offered for the current channel, the rate requirement of the handover user . for the number of handover users of the weight, for the number of handover users.

9. The method of claim 1, wherein, Calculating the handoff user in step (10) Accessing the satellite The maximum weighted satisfaction of all available handoff channels and the maximum resource utilization Adjusting the service channel of the handoff user , updating the reservation information table of the handoff channel, and implementing the steps include the following: 10a) setting a maximum weighted satisfaction , setting a target channel , setting a set of available handoff channels for a low earth orbit satellite , , , for a low earth orbit satellite , traversing each available handoff channel handoff users accessing their weighted satisfaction with a set maximum weighted satisfaction comparison: If , the maximum weighted satisfaction is updated to , and is updated to ; Otherwise, continue to traverse the next available switching channel until all available switching channels are traversed. 10b) setting a maximum resource utilization , calculating a handover user accessing a target channel resource utilization : ； wherein target channel offered transmission rate, switching users rate requirements, 10c) setting the maximum resource utilization , again comparing the maximum weighted satisfaction and the maximum resource utilization with the weighted satisfaction and the resource utilization , respectively: If , then update the reservation information table of the handoff channel as the service channel of the handoff user ; and , update the reservation information table of the handoff channel as the service channel of the handoff user Otherwise, keep the initial access selection of the handover user .

10. The method of claim 1, wherein: The step (8) sums up and averages the weighted satisfaction of all the switched users The formula is as follows: ； wherein, is the weighted satisfaction of the switching user , is the number of switching users; The step (12) of calculating the optimization target value The formula is as follows: ； wherein, is the user access success rate, is the user handover success rate, is the user average weighted satisfaction.

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