On-satellite time-frequency resource dynamic allocation method based on task priority

Abstract

The invention relates to an on-satellite time-frequency resource dynamic allocation method based on task priority. The method comprises the following steps: judging the type of a time-frequency resource allocation scene; for a conventional allocation scene, determining a resource allocation sequence of communication tasks, and allocating resources in sequence based on a heuristic rule; for a small-scale emergency allocation scene, matching a high-priority task with a conventional task in combination with an on-satellite time-frequency resource occupation condition, and after replacing the paired conventional task with the high-priority task, reallocating resources for the replaced conventional task; for a large-scale emergency allocation scene, releasing time-frequency resources occupied by unprocessed tasks on a satellite, integrating the tasks according to priorities, allocating resources for high-priority tasks and conventional tasks in sequence, and updating the utilization condition of the time-frequency resources; according to the method, the priority of the communication task is considered, limited time-frequency resources on the satellite are flexibly allocated under different communication requirements, the average time-frequency resource utilization rate of the satellite is maintained at a relatively high level, and reliable transmission of the task is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of two-dimensional time-frequency resource allocation, and in particular to a method for dynamically allocating on-board time-frequency resources based on task priorities. Background Art

[0002] The integration of satellite and ground networks has led to an increasing demand for on-board frequency and time resources in areas such as public life, social management, and national defense science and technology. At every moment, there are a large number of communication tasks from ground base stations, mobile devices, or ocean-going ships, which need to be transmitted to designated terminals through a huge satellite-ground network. At the same time, the occurrence of emergencies such as natural disasters, public health events, or social security events will cause the satellite network to receive a certain number of emergency tasks in a short period of time. These tasks are extremely sensitive to latency and should be given a higher priority in the allocation of frequency and time resources. Therefore, considering the priority of tasks, the arrival of high-priority tasks will change the allocation of frequency and time resources on the satellite and the order in which the satellite processes various tasks, and requires efficient execution of the on-board frequency and time resource reallocation process to ensure that high-priority tasks are processed in a timely manner.

[0003] Since the communication tasks in the satellite network have attributes such as time resources, frequency resources and task priority, each task can occupy a rectangular area of ​​satellite time and frequency resources, and the time and frequency resources occupied by different tasks cannot overlap with each other, allowing high-priority tasks to preempt the time and frequency resources of conventional tasks. However, the satellite network is a frequency and memory-constrained system. A single satellite can only provide frequency resources with limited bandwidth, and tasks that exceed the satellite's storage capacity will be lost, resulting in failure to successfully transmit to the target satellite, causing information loss.

[0004] At the same time, existing time-frequency resource allocation strategies generally have problems such as high computational complexity, difficult satellite deployment, and low time-frequency resource utilization, which make it difficult to meet the timeliness requirements of high-priority tasks, resulting in low throughput and operating efficiency of satellite networks and poor emergency response performance. Summary of the invention

[0005] In view of this, in order to meet the communication task requirements proposed by more user terminals, quickly and reasonably allocate the occupation of on-board time and frequency resources by tasks, and improve the utilization rate of on-board time and frequency resources, the present invention provides a method for dynamically allocating on-board time and frequency resources based on task priorities, comprising the following steps:

[0006] S1. Determine the type of time-frequency resource allocation scenario according to the number of high-priority tasks received by the satellite in real time, including conventional allocation scenario, small-scale emergency allocation scenario and large-scale emergency allocation scenario;

[0007] If it is determined to be a regular allocation scenario, execute step S2;

[0008] If it is determined to be a small-scale emergency allocation scenario, execute step S3;

[0009] If it is determined to be a large-scale emergency distribution scenario, step S4 is executed;

[0010] S2. For conventional allocation scenarios, a heuristic online time-frequency allocation method is used to allocate on-board time-frequency resources;

[0011] S201, using a swarm optimization algorithm to determine the resource allocation order of tasks;

[0012] S202, allocating on-board time and frequency resources in sequence based on heuristic rules;

[0013] S3. For small-scale emergency allocation scenarios, a comprehensive allocation method of time-frequency resources is used to allocate on-board time-frequency resources;

[0014] S301, matching high-priority tasks with regular tasks based on the occupancy of onboard time and frequency resources;

[0015] S302, the high priority task replaces the matching regular task;

[0016] S303, reallocating time-frequency resources for the replaced conventional tasks using a heuristic online time-frequency allocation method;

[0017] S4. For large-scale emergency allocation scenarios, a two-stage allocation method for time-frequency resources is used to allocate on-board time-frequency resources;

[0018] S401, releasing the time and frequency resources of unprocessed tasks on the satellite and integrating tasks according to priority;

[0019] S402, using a heuristic online time-frequency allocation method to allocate time-frequency resources to high-priority tasks and regular tasks in turn;

[0020] S403: Update the occupancy status of on-board time and frequency resources.

[0021] Preferably, the conventional allocation scenario determines the resource allocation order according to the order of task arrival time, and the small-scale emergency allocation scenario and the large-scale emergency allocation scenario determine the resource allocation order according to the task priority.

[0022] Preferably, the task is modeled in two dimensions, a task resource block is constructed according to the time and frequency resources required for the task, and the task priority is determined according to the delay sensitivity of the task; conventional tasks have no task deadline, and high-priority tasks must be completed within a preset deadline.

[0023] Preferably, the heuristic online time-frequency allocation method allocates time-frequency resources to tasks based on the concave space information formed by the occupied on-board time-frequency resources and based on five heuristic rules: complete matching principle, width matching principle, height matching principle, combined height matching principle and loadable principle.

[0024] Preferably, the concave space information of the tasks to which the heuristic rules are not applicable is recorded, and the heuristic time-frequency resource allocation is performed again on the tasks without considering the concave space.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention combines actual communication task requirements, considers emergency situations such as natural disasters that the satellite-to-ground network may face, sets task priorities, and designs different dynamic allocation methods for diversified time-frequency resource allocation scenarios, thereby improving the emergency response capability of the satellite-to-ground network and ensuring the communication quality of the satellite-to-ground network under different communication requests;

[0027] 2. The present invention determines the time-frequency resource allocation order of tasks through a swarm intelligence algorithm with strong search and convergence capabilities, realizes efficient and flexible allocation of on-board resources, and ensures that the average time-frequency resource utilization rate of the satellite is maintained at a high level to meet the reliable transmission of multiple tasks;

[0028] 3. The present invention utilizes the delay-sensitive characteristics of high-priority tasks and adopts a preemptive transmission scheme. In a small-scale emergency allocation scenario, it quickly allocates time and frequency resources to high-priority tasks through task matching and task replacement while minimizing changes to the initial allocation scheme. At the same time, in a large-scale emergency allocation scenario, a two-stage allocation method is designed to reallocate time and frequency resources, thereby achieving low-cost updates of the time and frequency resource allocation scheme. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the process of the present invention;

[0030] Figure 2 Schematic diagram of the heuristic rules of the present invention;

[0031] Figure 3 It is a time variation curve diagram of the satellite average time-frequency resource utilization rate in the conventional allocation scenario of the present invention;

[0032] Figure 4 This is a time variation curve of the satellite average time-frequency resource utilization rate in the emergency allocation scenario of the present invention. DETAILED DESCRIPTION

[0033] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation mode, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0034] Existing time-frequency resource allocation strategies generally have the problems of high computational complexity, difficulty in satellite deployment, and low time-frequency resource utilization, which makes it difficult to meet the timeliness requirements of high-priority tasks, resulting in low throughput and operating efficiency of satellite networks and poor emergency response performance. In order to meet the communication task requirements proposed by more user terminals, quickly and reasonably allocate the occupancy of on-board time-frequency resources by tasks, and improve the utilization of on-board time-frequency resources, the present invention provides an on-board time-frequency resource dynamic allocation method based on task priority, comprising the following steps:

[0035] S1. Determine the type of time-frequency resource allocation scenario according to the number of high-priority tasks received by the satellite in real time, and divide it into regular allocation scenario, small-scale emergency allocation scenario and large-scale emergency allocation scenario according to the number of high-priority tasks to be allocated;

[0036] If it is determined to be a regular allocation scenario, execute step S2;

[0037] If it is determined to be a small-scale emergency allocation scenario, execute step S3;

[0038] If it is determined to be a large-scale emergency distribution scenario, step S4 is executed;

[0039] In conventional allocation scenarios, the resource allocation order is determined according to the order of task arrival time, while in small-scale emergency allocation scenarios and large-scale emergency allocation scenarios, the resource allocation order is determined according to task priority;

[0040] Tasks are modeled in two dimensions. Task resource blocks are constructed based on the time and frequency resources required by the tasks. Task priorities are determined based on the delay sensitivity of the tasks. Regular tasks have no deadlines, and high-priority tasks must be completed within the preset deadlines, allowing high-priority tasks to preempt the time and frequency resources of regular tasks.

[0041] S2. For conventional allocation scenarios, a heuristic online time-frequency allocation method is used to allocate on-board time-frequency resources, which improves the efficiency of on-board time-frequency resource allocation;

[0042] S201, using a swarm optimization algorithm to determine the resource allocation order of tasks;

[0043] S202, allocating on-board time and frequency resources in sequence based on heuristic rules;

[0044] like Figure 2The heuristic online time-frequency allocation method shown is to allocate time-frequency resources to tasks based on the concave space information formed by the occupied on-board time-frequency resources based on five heuristic rules: complete matching principle, width matching principle, height matching principle, combined height matching principle and loadable principle, so as to improve the utilization rate of concave space resources, record the concave space information of tasks that are not applicable to the heuristic rules, and perform heuristic time-frequency resource allocation for tasks again without considering the concave space;

[0045] S3. For small-scale emergency allocation scenarios, a comprehensive allocation method of time-frequency resources is used to allocate on-board time-frequency resources, so that the change of the initial allocation plan is minimized;

[0046] S301, combining the on-board time and frequency resource occupancy situation, according to the estimated transmission time of the conventional tasks already carried by the satellite, and in order from early to late, matching the time and frequency resource requirements of the high-priority tasks with the conventional tasks;

[0047] S302, the high priority task replaces the matching regular task;

[0048] S303, reallocating time-frequency resources for the replaced conventional tasks using a heuristic online time-frequency allocation method;

[0049] S4. For large-scale emergency allocation scenarios, a two-stage allocation method for time-frequency resources is used to allocate on-board time-frequency resources, achieving low-cost updates of time-frequency resource allocation;

[0050] S401, releasing the time and frequency resources of unprocessed tasks on the satellite and integrating tasks according to priority;

[0051] S402, using a heuristic online time-frequency allocation method to allocate time-frequency resources to high-priority tasks and regular tasks in turn;

[0052] S403: Update the occupancy status of on-board time and frequency resources.

[0053] In this embodiment, the frequency resources required for the communication task conform to the Gamma distribution, the required transmission time conforms to the uniform distribution of 0 to 0.5s, the maximum bandwidth of a single satellite is 256Mbps, the memory is 500Mbs, and it can store about 100 communication tasks;

[0054] In the conventional allocation scenario, the satellite-to-ground network simulation scenario is run continuously for 20 seconds, and the average satellite time and frequency resource utilization within 1-20 seconds is recorded, such as Figure 3 As shown, it can be obtained that the satellite's average time-frequency resource utilization rate is in the range of 90%-95%, always maintaining at a high level;

[0055] In the emergency allocation scenario, the priority of the communication task is randomly set. The change of the satellite average time and frequency resource utilization rate in the satellite-ground network equation within 20 seconds is as follows: Figure 4 As shown in the figure, it can be found that in the scenario where tasks have priority allocation, the average time and frequency resource utilization of the satellite can still be maintained in the range of 90%-95%;

[0056] Judging from the data, the on-board time-frequency resource dynamic allocation method provided by the present invention has good stability and adaptability, and can efficiently and flexibly allocate on-board resources under the requests of different communication tasks, thereby fully utilizing the satellite's limited time-frequency resources, ensuring stable and reliable transmission in the case of multiple tasks, and guaranteeing the communication quality of the satellite-to-earth network.

[0057] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for dynamically allocating on-board time and frequency resources based on task priority, characterized in that: The following steps are involved: S1. Determine the type of time-frequency resource allocation scenario according to the number of high-priority tasks received by the satellite in real time, including conventional allocation scenario, small-scale emergency allocation scenario and large-scale emergency allocation scenario; If it is determined to be a regular allocation scenario, execute step S2; If it is determined to be a small-scale emergency allocation scenario, execute step S3; If it is determined to be a large-scale emergency distribution scenario, step S4 is executed; S2. For conventional allocation scenarios, a heuristic online time-frequency allocation method is used to allocate on-board time-frequency resources; S201, using a swarm optimization algorithm to determine the resource allocation order of tasks; S202, allocating on-board time and frequency resources in sequence based on heuristic rules; S3. For small-scale emergency allocation scenarios, a comprehensive allocation method of time-frequency resources is used to allocate on-board time-frequency resources; S301, matching high-priority tasks with regular tasks based on the occupancy of onboard time and frequency resources; S302, the high priority task replaces the matching regular task; S303, reallocating time-frequency resources for the replaced conventional tasks using a heuristic online time-frequency allocation method; S4. For large-scale emergency allocation scenarios, a two-stage allocation method for time-frequency resources is used to allocate on-board time-frequency resources; S401, releasing the time and frequency resources of unprocessed tasks on the satellite and integrating tasks according to priority; S402, using a heuristic online time-frequency allocation method to allocate time-frequency resources to high-priority tasks and regular tasks in turn; S403: Update the occupancy status of on-board time and frequency resources.

2. The method for dynamically allocating on-board time and frequency resources based on task priority according to claim 1, characterized in that: In the conventional allocation scenario, the resource allocation order is determined according to the order of task arrival time, while in the small-scale emergency allocation scenario and the large-scale emergency allocation scenario, the resource allocation order is determined according to the task priority.

3. The method for dynamically allocating on-board time and frequency resources based on task priority according to claim 2, characterized in that: The task is modeled in two dimensions, task resource blocks are constructed according to the time and frequency resources required by the task, and task priorities are determined according to the delay sensitivity of the task; Regular tasks have no deadlines, and high-priority tasks must be completed within the preset deadlines.

4. The method for dynamically allocating on-board time and frequency resources based on task priority according to claim 1, characterized in that: The heuristic online time-frequency allocation method allocates time-frequency resources to tasks based on the concave space information formed by the occupied on-board time-frequency resources and five heuristic rules: complete matching principle, width matching principle, height matching principle, combined height matching principle and loadable principle.

5. The method for dynamically allocating on-board time and frequency resources based on task priority according to claim 4, characterized in that: The concave space information of the tasks that are not applicable to the heuristic rules is recorded, and the heuristic time-frequency resource allocation is performed again on the tasks without considering the concave space.

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