Research On Download Of Dynamically Generated Data By Using Isl Offloading In Leo Networks

With the advent of 5G,the global communication system becomes more and more developed and communication in cities and other densely populated areas becomes more and more convenient.Satellite network system has attracted the attention of many scholars and companies due to the fast development of the overall communication system,it play an important role in the communication in the some areas where the earth station can not deploy.The satellites launched to the orbit form constellations and move in a circle around the earth,which can not only communicate with the areas that have developed communication system but also can detect information in a less traveled place to make the informationmore accessible.Low Earth Orbit(Low Earth Orbit,LEO)satellite have widely used in global communication,weather forecast,disaster prevention and geological exploration,etc,due to its small volume,Low altitude,low launch costs.However,the data on the satellite cannot be downloaded to the ground station in time due to its small coverage and long communication delay.An important task of the LEO satellite network is to transmit data collected from the aerial orbit to the ground station for users to use.In this paper,we propose an algorithm to download satellite data to the ground station and optimize the throughput in different scenarios.This paper consider the variability of real-time data under the data dynamically producing cases.A DIOC(Dividing and ISL Offloading Combination)algorithm has been proposed.In each time slice,satellite with the largest amount of data is to be considered first to download data,and the intersatellite scheduling of the other satellites was determined based on the three-hop situation of the time slice,which greatly improved the download throughput of the satellite system.Simulation results show that our algorithm is much more efficient than the traditional satellite download algorithm in different scenarios,and the throughput of the system can approach the theoretical optimal result after removing some objective factors.We continue to study how to improve the throughput of the satellite system under the condition of limited channel resources based on the dynamic data scenario.Due to the constraints of channel resources,the scheduling needs to balance the relationship among satellite download,inter-satellite scheduling and satellite channel resource allocation.A DIOC-BP(Dividing and ISL Offloading Combination-Backtracking Pruning)algorithm is proposed to maximize the throughput of the system by ensuring the maximization ofinter-satellite scheduling in each time slice.In this paper,a comparative simulation experiment is carried out for the above two scenarios.Simulation results show that under the condition of constraints channel resources,the proposed algorithm scheduling can achieve the optimal throughput under the condition of sufficient channel resources.