A channel allocation method for medium and low orbit satellites based on pre-estimation

Abstract

The present invention discloses a method for allocating medium and low orbit satellite channels based on pre-estimation, the method comprising: when a new call request arrives at the current cell and there is no idle channel, obtaining the users corresponding to all reserved channels in the current cell, calculating the channel preemption threshold probability corresponding to the user; obtaining the maximum probability in the channel preemption threshold probability, obtaining the corresponding reserved channel; the new call is preempted with the maximum probability; after the preemption is successful, judging whether there is an idle channel in the next cell, if there is, setting the idle channel as the reserved channel of the new call in the next cell, and accessing the new call, otherwise the new call is blocked; the present invention also discloses a medium and low orbit satellite channel allocation device based on pre-estimation, corresponding equipment and storage medium. The present invention estimates the probability of a user ending a call, reasonably allocates reserved channel resources, and realizes effective allocation of channel resources under the condition of high-volume voice services.

Description

Technical Field

[0001] The present invention relates to the field of network communication technology, and more specifically, to a method for allocating medium and low orbit satellite channels based on pre-estimation. Background Art

[0002] Due to their special orbital position, short satellite-to-ground links and short signal propagation delay, medium and low-orbit satellites can provide information and communication services to remote users and users sailing in the open seas who lack ground infrastructure, and have received extensive attention from experts in the field. For multi-beam satellites, the sub-satellite area of ​​the satellite is a honeycomb structure, and the channel resources of each cell are different. Due to the fast movement speed of low-orbit satellites, multiple channel switches may be required during a communication process. For users, call interruptions during a call are more unacceptable than call blocking at the beginning. In order to effectively improve the quality of user communication services, it is necessary to design an efficient channel reservation strategy to shield the impact of inter-cell switching on user communications. At the same time, efficient resource integration and rational use of limited channel resources are the key to studying satellite channel allocation issues.

[0003] In the existing simulation experiments of medium and low orbit satellite channel allocation, there are generally two channel allocation strategies. The first channel allocation strategy will allocate the same number of channels to users in the next cell at the same time according to the number of users accessing the current satellite beam coverage cell (referred to as "cell"). This can ensure 100% handover success for users accessing the satellite communication system. However, since channels are reserved for all users in the current cell in the next cell, the number of newly arrived users in the next cell is significantly reduced, and the utilization efficiency of system resources is greatly reduced. Users are likely to end calls in the current cell, which will cause resource waste when the number of users accessing is large. The second channel allocation strategy is to reserve a fixed number of channels for handover calls in each beam cell, generally at a ratio of 10%-20%. These channels will only be used for handover calls. Compared with the first channel allocation method, this method can further improve the utilization rate of channel resources. However, when the number of users accessing is large, the handover call channel will not be enough to support the handover call requests of all users, resulting in the failure of call handover for some users and the decline of the quality of user call experience. Summary of the invention

[0004] In response to at least one defect or improvement need in the prior art, the present invention provides a method, apparatus, device and storage medium for allocating medium and low orbit satellite channels based on pre-estimation, which estimates the probability of a user ending a call, reasonably allocates reserved channel resources, and realizes effective allocation of channel resources under conditions of high-volume voice services.

[0005] To achieve the above object, according to a first aspect of the present invention, a method for allocating medium and low orbit satellite channels based on pre-estimation is provided, the method comprising:

[0006] S1. When a new call request arrives at the current satellite beam coverage cell and there is no idle channel in the current satellite beam coverage cell, obtain the users corresponding to all reserved channels in the current satellite beam coverage cell and calculate the channel preemption threshold probability corresponding to the user;

[0007] S2. Obtain the maximum probability of the channel preemption threshold probability, and obtain the maximum probability corresponding to the user's reserved channel in the current satellite beam coverage cell;

[0008] S3. The new call occupies the reserved channel in step S2 with the maximum value;

[0009] S4. After the S3 step is successfully seized, it is determined whether there is an idle channel in the next satellite beam coverage cell. If so, the idle channel is set as the reserved channel for the new call in the next satellite beam coverage cell, and the new call is connected, otherwise the new call is blocked;

[0010] The channel preemption threshold probability is used to indicate the probability that a user in the cell currently covered by the satellite beam does not need to use the reserved channel of the user in the cell currently covered by the satellite beam at the current moment.

[0011] Furthermore, the above-mentioned method for allocating medium and low orbit satellite channels based on pre-estimation also includes:

[0012] The step S1 comprises:

[0013] S11. Get the number of users who are currently making calls in the cell covered by the previous satellite beam, denoted as C r ;

[0014] S12. Obtain the above C r The first distance from a user to the boundary of the cell covered by the previous satellite beam and the cell covered by the current satellite beam is set as the parameter Q j :

[0015]

[0016] Where X j represents the first distance of the j-th user;

[0017] S13. Obtain the number of switching times k that the user has completed at the current moment j ;

[0018] S14. Calculate the channel preemption threshold probability T of the userj :

[0019]

[0020] Among them, P k is the terrestrial user switching probability, which is used to indicate the probability that the terrestrial user performs the kth switching.

[0021] Furthermore, the above-mentioned method for allocating medium and low orbit satellite channels based on pre-estimation also includes:

[0022] The calculation method of the ground user switching probability is:

[0023] A first probability is set, which is expressed as the probability that when the user fails to end the call in the cell covered by the current satellite beam, the user needs to switch to the cell covered by the next satellite beam to continue the call:

[0024]

[0025] Among them, t mc1 represents the movement time of the user in the cell covered by the current satellite beam, which is calculated as the ratio of the distance between the user and the right edge of the cell covered by the current satellite beam to the moving speed of the sub-satellite point, p tmc1 (t) is t mc1 The probability density function of d is the call duration;

[0026] A second probability is set, which is expressed as the probability that the user needs to switch again when the call is not ended after switching from the current satellite beam coverage cell to the next satellite beam coverage cell:

[0027]

[0028] Among them, t mc2 It represents the complete movement time of the user in the cell covered by the satellite beam, and the calculation method is as follows:

[0029]

[0030] According to the first probability and the second probability, the terrestrial user switching probability P is calculated. k as follows:

[0031] Pk=Ph1Ph2k-1,

[0032] Where k represents the number of switching times;

[0033] Among them, α mis the user mobility parameter that describes the degree of user mobility and is calculated as the ratio of the length of the satellite's subsatellite spot beam to the average distance the user moves during the call duration:

[0034]

[0035] Among them, V sat is the moving speed of the satellite sub-satellite point in the satellite beam coverage area, R is the average diameter of the spot beam, T m is the average call duration.

[0036] Furthermore, the above-mentioned method for allocating medium and low orbit satellite channels based on pre-estimation also includes:

[0037] The step S4 further comprises:

[0038] S41. Calculate the average number of switching times nk for all users;

[0039] S42. Obtain the users corresponding to all reserved channels in the cell covered by the i-th satellite beam, number the users as 1 to j', and obtain the switching times n of the users j' , extract the switching times satisfying n j' >nk+n' corresponds to users and is numbered from 1 to j;

[0040] S43. Calculate the channel preemption threshold probability T corresponding to the user j , obtain the channel preemption threshold probability T j The maximum value max{T j}, get the max{T j} corresponds to the reserved channel C of the user in the cell currently covered by the satellite beam rj , the new call starts with the max{T j} probability of occupying the reserved channel C rj If the preemption is successful, go to S5, otherwise the new call is blocked;

[0041] Wherein, n' is a set threshold value, and the average number of switching times nk is calculated as follows:

[0042]

[0043] Among them, V sat is the moving speed of the satellite sub-satellite point in the satellite beam coverage area, R is the average diameter of the spot beam, T m is the average call duration.

[0044] Furthermore, the above-mentioned method for allocating medium and low orbit satellite channels based on pre-estimation also includes:

[0045] The n' preferably satisfies P [nk+n']+1 ≤20% threshold, where [nk+n'] represents the integer rounded down to nk+n'.

[0046] Furthermore, the above-mentioned method for allocating medium and low orbit satellite channels based on pre-estimation also includes:

[0047] When a new call request arrives at the current satellite beam coverage cell and there is an idle channel in the current satellite beam coverage cell, the new call directly occupies the idle channel and determines whether there is an idle channel in the next satellite beam coverage cell. If so, the idle channel is set as the reserved channel for the new call in the next satellite beam coverage cell and the new call is connected. Otherwise, the new call is blocked.

[0048] Furthermore, the above-mentioned method for allocating medium and low orbit satellite channels based on pre-estimation also includes:

[0049] In the step S3, if the reserved channel is seized but fails, the new call is blocked.

[0050] According to a second aspect of the present invention, there is also provided a medium and low orbit satellite channel allocation device based on pre-estimation, which comprises:

[0051] An information collection module configured to collect data for channel allocation;

[0052] The information processing module is configured to read the data of the information collection module and execute any one of the channel allocation methods described above.

[0053] According to the third aspect of the present invention, there is also provided a medium and low orbit satellite channel allocation device based on pre-estimation, which includes at least one processing unit and at least one storage unit, wherein the storage unit stores a computer program, and when the computer program is executed by the processing unit, the processing unit executes the steps of any one of the channel allocation methods described above.

[0054] According to a fourth aspect of the present invention, there is also provided a storage medium storing a computer program executable by an access authentication device, wherein when the computer program runs on the access authentication device, the access authentication device executes the steps of any one of the channel allocation methods described above.

[0055] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0056] The present invention provides a method for allocating medium and low orbit satellite channels based on pre-estimation, which estimates the probability of a user ending a call, reasonably allocates reserved channel resources, and realizes effective allocation of channel resources under conditions of high-volume voice services, which can effectively reduce the probability of user call blocking and greatly improve user service quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0058] Figure 1 A schematic diagram of a flow chart of a method for allocating medium and low orbit satellite channels based on pre-estimation provided by an embodiment of the present invention;

[0059] Figure 2 A schematic diagram of the relative position relationship between satellites and users in a method for allocating medium and low orbit satellite channels based on pre-estimation provided by an embodiment of the present invention;

[0060] Figure 3 A schematic diagram of various stages in the communication process of a method for allocating medium and low orbit satellite channels based on pre-estimation provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0062] The terms "first", "second", "third", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0063] like Figure 1 As shown, as a first embodiment of the present invention, a method for allocating medium and low orbit satellite channels based on pre-estimation is provided, the method comprising:

[0064] S1. When a new call request arrives at the current satellite beam coverage cell and there is no idle channel in the current satellite beam coverage cell, obtain the users corresponding to all reserved channels in the current satellite beam coverage cell and calculate the channel preemption threshold probability corresponding to the user;

[0065] S2. Obtain the maximum probability of the channel preemption threshold probability, and obtain the maximum probability corresponding to the user's reserved channel in the current satellite beam coverage cell;

[0066] S3. The new call occupies the reserved channel in step S2 with the maximum value;

[0067] S4. After the S3 step is successfully seized, it is determined whether there is an idle channel in the next satellite beam coverage cell. If so, the idle channel is set as the reserved channel for the new call in the next satellite beam coverage cell, and the new call is connected, otherwise the new call is blocked;

[0068] The channel preemption threshold probability is used to indicate the probability that a user in the cell currently covered by the satellite beam does not need to use the reserved channel of the user in the cell currently covered by the satellite beam at the current moment.

[0069] For multi-beam satellites, the sub-satellite area of ​​the satellite forms a honeycomb structure, and the channel resources of each cell are different. Due to the high movement speed of low-orbit satellites, multiple channel switching may be required during a communication process, that is, switching from the cell covered by the satellite beam of the previous satellite to the cell covered by the next satellite beam. For users, call interruption during a call is more unacceptable than call blocking at the beginning. In order to effectively improve the quality of user communication services, an efficient channel reservation strategy is designed to shield the impact of inter-cell switching on user communications. At the same time, efficient integration of resources and reasonable use of limited channel resources are the key to studying satellite channel allocation issues.

[0070] Channels in a single cell are divided into idle channels, channels in use and reserved channels, where idle channels are the channels that are given priority when making calls, and channels in use are generally not suitable for occupation to avoid cutting off the calls of users who are using the channels. The present invention provides a method for allocating medium and low orbit satellite channels based on pre-estimation, which estimates the probability of users ending calls through calculation and analysis, reasonably allocates reserved channel resources, and realizes effective allocation of channel resources under the condition of high-volume voice services.

[0071] like Figure 2 As shown, as the second embodiment of the present invention, based on the first embodiment, this embodiment also includes:

[0072] The step S1 comprises:

[0073] S11. Get the number of users who are currently making calls in the cell covered by the previous satellite beam, denoted as C r ;

[0074] S12. Obtain the above C r The first distance from a user to the boundary of the cell covered by the previous satellite beam and the cell covered by the current satellite beam is set as the parameter Q j :

[0075]

[0076] Where X j represents the first distance of the j-th user;

[0077] S13. Obtain the number of switching times k that the user has completed at the current moment j ;

[0078] S14. Calculate the channel preemption threshold probability T of the user j :

[0079]

[0080] Among them, P k is the terrestrial user switching probability, which is used to indicate the probability that the terrestrial user performs the kth switching.

[0081] In this embodiment, the users who are talking in the i-1th cell have corresponding reserved channels in the i-th cell. Therefore, the number of users is the number of reserved channels in the i-th cell, which is recorded as C. r Here we calculate the channel preemption threshold probability T j , is to calculate the probability that the above users do not need to use the reserved channel. In other words, if the user ends the call in the i-1th cell, or the user will not switch to the i-th cell in a short time, then the reserved channel of the user in the i-th cell can be accessed by the new user. Conversely, if it is believed that the user is unlikely to end the call in the i-1th cell, and the user will switch to the i-th cell in a short time, then the reserved channel of the user in the i-th cell still needs to be reserved for him, and it is not advisable to accept new calls, so as to avoid call interruptions during the call as much as possible.

[0082] The channel seizure threshold probability involves two probability parameters P k and Q j , where the parameter Q j Indicates that the distance from the boundary of cell i-1 and cell i is X jThe probability of a call switching in a short time. It can be seen that the closer the value is to 1, the farther away the user is. It takes a longer time for the switching to occur. During this period of time, the user in cell i has the opportunity to enter the next cell or end the call.

[0083] As the third embodiment of the present invention, based on the second embodiment, this embodiment further includes:

[0084] The calculation method of the ground user switching probability is:

[0085] A first probability is set, which is expressed as the probability that when the user fails to end the call in the cell covered by the current satellite beam, the user needs to switch to the cell covered by the next satellite beam to continue the call:

[0086]

[0087] Among them, t mc1 represents the movement time of the user in the cell covered by the current satellite beam, which is calculated as the ratio of the distance between the user and the right edge of the cell covered by the current satellite beam to the moving speed of the sub-satellite point, p tmc1 (t) is t mc1 The probability density function of d is the call duration;

[0088] A second probability is set, which is expressed as the probability that the user needs to switch again when the call is not ended after switching from the current satellite beam coverage cell to the next satellite beam coverage cell:

[0089]

[0090] Among them, t mc2 It represents the complete movement time of the user in the cell covered by the satellite beam, and the calculation method is as follows:

[0091]

[0092] According to the first probability and the second probability, the terrestrial user switching probability P is calculated. k as follows:

[0093] Pk=Ph1Ph2k-1,

[0094] Where k represents the number of switching times;

[0095] Among them, α m is the user mobility parameter that describes the degree of user mobility and is calculated as the ratio of the length of the satellite's subsatellite spot beam to the average distance the user moves during the call duration:

[0096]

[0097] Among them, V sat is the moving speed of the satellite sub-satellite point in the satellite beam coverage area, R is the average diameter of the spot beam, T m is the average call duration.

[0098] The first probability mentioned in this embodiment is the probability that the user needs to switch once when the call is not finished in the current cell. The second probability is the probability that the user needs to switch in the next complete cell after the switch. For each user who is on a call, when k switches occur, only the first switch is based on the first probability. After the switch is completed once, all subsequent switches need to go through the complete cell, so the probability is the second probability. k It is not difficult to find that the user's phone call duration tends to the average value, that is, T m , which means that the probability of users being in a call state for a long time, resulting in a large number of handovers, is relatively low.

[0099] The user mobility parameter α modeled in this embodiment m It is a simple modeling method applied to medium and low orbit satellites. For medium and low orbit satellites, their moving speed is fast, and users can be considered to be stationary relative to the satellite. Therefore, the above user mobility parameter only considers the moving speed of the satellite. The channel allocation method described in the present invention can also be applied to high orbit satellites. For high orbit satellites, they can be considered to be stationary relative to the earth. Therefore, when the user is in a high-speed moving state (for example, on a high-speed vehicle), the above user mobility parameter α can be used. m The speed in is modified to the user's speed, and the method of the present invention can also be applied.

[0100] The specific modeling method in this embodiment is a preferred implementation method with simple calculation. It is easy for those skilled in the art to know that when the modeling method is different, the ground user switching probability P k and channel preemption threshold probability T j The specific calculation method of is also different, that is, the above probability is not limited to the calculation method of the subsequent steps in this embodiment.

[0101] As the fourth embodiment of the present invention, based on the third embodiment, this embodiment further includes:

[0102] The step S4 further comprises:

[0103] S41. Calculate the average number of switching times nk for all users;

[0104] S42. Obtain the users corresponding to all reserved channels in the cell covered by the i-th satellite beam, number the users as 1 to j', and obtain the switching times n of the users j' , extract the switching times satisfying n j' >nk+n' corresponds to users and is numbered from 1 to j;

[0105] S43. Calculate the channel preemption threshold probability T corresponding to the user j , obtain the channel preemption threshold probability T j The maximum value max{T j}, get the max{T j} corresponds to the reserved channel C of the user in the cell currently covered by the satellite beam rj , the new call starts with the max{T j} probability of occupying the reserved channel C rj If the preemption is successful, go to S5, otherwise the new call is blocked;

[0106] Wherein, n' is a set threshold value, and the average number of switching times nk is calculated as follows:

[0107]

[0108] Among them, V sat is the moving speed of the satellite sub-satellite point in the satellite beam coverage area, R is the average diameter of the spot beam, T m is the average call duration.

[0109] Furthermore, this embodiment also includes:

[0110] The n' preferably satisfies P [nk+n']+1 ≤20% threshold, where [nk+n'] represents the integer rounded down to nk+n'.

[0111] In this embodiment, if there are multiple newly accessed users or users who have switched less frequently in the previous cell, these users will switch with a high probability. If their channels are seized, the calls of these users will also be interrupted, reducing the call experience of these users. The channel seizure threshold probability set by the present invention is not only related to the number of switches, but also to the distance from the user to the cell boundary. Therefore, the above-mentioned newly accessed or less frequently switched users may still calculate a larger channel seizure threshold probability, so that their reserved channels are seized by new calls. Therefore, setting a certain switching threshold to ensure that new calls only seize users whose switching times exceed a certain value can further improve the user's call experience.

[0112] Since the terrestrial user switching probability P kis a monotonically decreasing function of the switching number k, so P is preferred [nk+n']+1 ≤20% is used as the threshold value. At this time, the ground users have switched many times, and the probability of the call being completed is high, so the impact of preempting the reserved channels of these users is smaller. Those skilled in the art can also adjust the threshold value accordingly as needed.

[0113] As the fifth embodiment of the present invention, based on the fourth embodiment, this embodiment further includes:

[0114] When a new call request arrives at the current satellite beam coverage cell and there is an idle channel in the current satellite beam coverage cell, the new call directly occupies the idle channel and determines whether there is an idle channel in the next satellite beam coverage cell. If so, the idle channel is set as the reserved channel for the new call in the next satellite beam coverage cell and the new call is connected. Otherwise, the new call is blocked.

[0115] Furthermore, this embodiment also includes:

[0116] In the step S3, if the reserved channel is seized but fails, the new call is blocked.

[0117] By setting corresponding blocking rules, it is possible to avoid blocking the channel for new users when they access the site due to the lack of reserved channels, which results in a short talk time, thus avoiding a reduction in user experience.

[0118] The present invention also includes that for a user in a call, a rule for switching channels is set as follows:

[0119] Step 1: Determine whether the reserved channel of the user in the next cell is occupied. If so, go to step 2; if not, go to step 3;

[0120] Step 2: Determine whether there is an available channel in the next cell. If there is an available channel, go to step 3. If there is no available channel, switch to call blocking;

[0121] Step 3: Connect the call to the next cell, estimate the switching time, and reserve the channel within the corresponding time interval of the next cell.

[0122] That is, for a user in a call, it is only determined whether the user's channel in the next cell is occupied. If it is occupied, it is then determined whether there are vacant channels. If the user's channel is occupied and there are no vacant channels, the call is blocked.

[0123] As a sixth embodiment of the present invention, a medium- and low-orbit satellite channel allocation device based on pre-estimation is also provided, which includes:

[0124] An information collection module configured to collect data for channel allocation;

[0125] The information processing module is configured to read the data of the information collection module and execute any one of the channel allocation methods described above.

[0126] As the seventh embodiment of the present invention, there is also provided a medium and low orbit satellite channel allocation device based on pre-estimation, which includes at least one processing unit and at least one storage unit, wherein the storage unit stores a computer program, and when the computer program is executed by the processing unit, the processing unit executes the steps of any one of the channel allocation methods described above.

[0127] The present invention also provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of the above method when executed by a processor. The computer-readable storage medium may include, but is not limited to, any type of disk, including a floppy disk, an optical disk, a DVD, a CD-ROM, a micro drive, and a magneto-optical disk, a ROM, a RAM, an EPROM, an EEPROM, a DRAM, a VRAM, a flash memory device, a magnetic card or an optical card, a nanosystem (including a molecular memory IC), or any type of medium or device suitable for storing instructions and / or data.

[0128] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0129] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for allocating medium and low orbit satellite channels based on pre-estimation, characterized in that: S1. When a new call request arrives at the current satellite beam coverage cell, and there is no idle channel in the current satellite beam coverage cell, obtain the user corresponding to all reserved channels in the current satellite beam coverage cell, and calculate the channel preemption threshold probability corresponding to the user; S2. Obtain the maximum probability of the channel preemption threshold probability, obtain the maximum probability corresponding to the user in the current satellite beam coverage cell reserved channel; S3. The new call to seize the reserved channel in step S2 with the maximum probability; S4. After the S3 step is successfully seized, it is determined whether there is an idle channel in the next satellite beam coverage cell. If so, the idle channel is set as the reserved channel for the new call in the next satellite beam coverage cell, and the new call is accessed, otherwise the new call is blocked; The channel preemption threshold probability is used to indicate the probability that a user in the cell currently covered by the satellite beam does not need to use the reserved channel of the user in the cell currently covered by the satellite beam at the current moment.

2. A method for allocating medium and low orbit satellite channels based on pre-estimation as claimed in claim 1, characterized in that: The step S1 comprises: S11. Get the number of users who are currently making calls in the cell covered by the last satellite beam, recorded as ; S12. Get the above The first distance from a user to the boundary of the cell covered by the previous satellite beam and the cell covered by the current satellite beam is set as the parameter : ， in represents the first distance of the jth user, is the average diameter of the spot beam; S13. Get the C respectively r The number of switches that a user has completed at the current moment j ; S14. Calculate the C r The channel preemption threshold probability of a user : ， in, represents the probability that the current user j will make the next switch.

3. A method for allocating medium and low orbit satellite channels based on pre-estimation as claimed in claim 2, characterized in that: The calculation method of the ground user switching probability is: A first probability is set, which is expressed as the probability that when the user fails to end the call in the cell covered by the current satellite beam, the user needs to switch to the cell covered by the next satellite beam to continue the call: ， in, represents the movement time of the user in the cell covered by the current satellite beam, which is calculated as the ratio of the distance between the user and the right edge of the cell covered by the current satellite beam to the moving speed of the sub-satellite point. for The probability density function of is the call duration; A second probability is set, which is expressed as the probability that the user needs to switch again when the call is not ended after switching from the current satellite beam coverage cell to the next satellite beam coverage cell: ， in, It indicates the complete movement time of the user in the cell covered by the next satellite beam, and the calculation method is as follows: ； According to the first probability and the second probability, the probability of the kth handover of the ground user is calculated. as follows: ， Where k represents the number of switching times; in, is the user mobility parameter that describes the degree of user mobility and is calculated as the ratio of the length of the satellite's subsatellite spot beam to the average distance the user moves during the call duration: ， in, is the moving speed of the satellite sub-satellite point in the satellite beam coverage area, is the average diameter of the spot beam, is the average call duration.

4. The method for allocating medium and low orbit satellite channels based on pre-estimation according to claim 1, characterized in that: The step S4 further comprises: S41. Calculate the average number of switching times for all users ; S42. Obtaining the users corresponding to all reserved channels in the cell covered by the i-th satellite beam, numbering the users as 1~j', and obtaining the number of switching times of the users. , extract the switching times that meet The corresponding users are numbered 1~j; S43. Calculate the channel occupation threshold probability corresponding to the user , obtain the channel preemption threshold probability The maximum value in , obtain the The reserved channel of the corresponding user in the cell covered by the current satellite beam , the new call starts with Probability of occupying the reserved channel If the preemption is successful, go to S4, otherwise the new call is blocked; Among them, the is the set threshold, the average switching times The calculation method is: ； in, is the moving speed of the satellite sub-satellite point in the satellite beam coverage area, is the average diameter of the spot beam, is the average call duration.

5. The method for allocating medium and low orbit satellite channels based on pre-estimation according to claim 1, characterized in that: When a new call request arrives at the current satellite beam coverage cell and there is an idle channel in the current satellite beam coverage cell, the new call directly occupies the idle channel and determines whether there is an idle channel in the next satellite beam coverage cell. If so, the idle channel is set as the reserved channel for the new call in the next satellite beam coverage cell and the new call is connected. Otherwise, the new call is blocked.

6. The method for allocating medium and low orbit satellite channels based on pre-estimation according to claim 1, characterized in that: In the step S3, if the reserved channel is seized but fails, the new call is blocked.

7. A device for allocating medium and low orbit satellite channels based on pre-estimation, characterized in that: include: An information collection module configured to collect data for channel allocation; The information processing module is configured to read the data of the information collection module and execute the channel allocation method according to any one of claims 1 to 6.

8. A device for allocating medium and low orbit satellite channels based on pre-estimation, characterized in that: The method comprises at least one processing unit and at least one storage unit, wherein the storage unit stores a computer program, and when the computer program is executed by the processing unit, the processing unit executes the steps of the method according to any one of claims 1 to 6.

Images