Research On Phased Deployment Strategy Of Low Earth Orbit Satellite Constellation

With the development of communication technology,low-orbit satellites provide wider coverage and lower propagation delay,while having lower partial package costs,which will provide strong support for the development of new generation communication technology.At present,many countries are accelerating the deployment of low-speed satellites,hoping to obtain more applications in the fields of communication,meteorology,environmental monitoring,earth observation,and national security.However,due to the limited coverage of a single low-orbit satellite,it is usually necessary to use millions or even thousands of satellites to form a network to achieve wide-area coverage.At the same time,due to insufficient carrying capacity and the large amount of time and resources required to manufacture and launch satellites,it is impossible to realize the launch part of the large-scale simulated low-orbit constellation in the short term.Therefore,the construction of a low-orbit satellite network is generally divided into multiple stages.Satellites are deployed in different orbital planes and locations in each stage,and the communication service capabilities provided are also different.Based on the above analysis,how to optimize some configuration schemes at each stage of the constellation to ensure that the constellation can still provide better information transmission capabilities when all configurations are not completed is a problem to be solved at present.In view of the problems described above,the main work of this paper is introduced as follows:A multi-satellite deployment method based on genetic algorithm is proposed,and the optimal constellation deployment scheme is selected by optimizing different constellation performance indicators in the staged deployment process of the constellation.Firstly,a reasonable fitness function,coding method,selection,crossover and other genetic operations are designed to improve the performance of sub-constellations at each stage as much as possible,and the performance simulation verification is carried out through two low-orbit satellite constellations of different scales,and the genetic algorithm based on genetic algorithm is obtained.The four phases of the multi-satellite deployment method in different orbits have different degrees of improvement in the total coverage time of the target area,the maximum revisit time of the target area,the number of intersatellite links and the total duration of inter-satellite links.Secondly,considering that in the process of low-orbit constellation construction,due to its sparseness,the end-to-end path cannot be guaranteed.In-orbit satellites can provide services to users through storecarry-forward.In this paper,using the CGR routing algorithm in the DTN network,and using the OMNeT++network simulation software to conduct experiments on the performance of the sub-constellation network at each stage,it is obtained that the average packet hops of the off-track deployment method based on the genetic algorithm is 5.38%higher than that of the same-track sequential deployment method,and the average terminal The end-to-end delay is reduced by 84.87%,and the average data packet delivery rate is increased by 30.62%.