Handover Strategy Research And Simulation Platform Implementation For Satellite-Ground Converged Networks

With the successful deployment of numerous low-orbit satellites worldwide,the low-orbit satellite communication systems have garnered significant attention.These systems offer global coverage and low-latency features,providing considerable benefits for ground mobile communication technologies.However,in metropolitan areas with dense obstacles,the satellite signal attenuation may be pronounced,necessitating the integration of satellite and ground networks to develop more stable and reliable network infrastructure.While satellite-ground converged networks offer some advantages in combining the benefits of satellite and ground networks,the high-speed movement of satellites makes the fusion network structure dynamic,resulting in frequent handover between ground terminals and satellite nodes and causing network overload.Current routing algorithms in satellite-ground converged networks fail to comprehensively consider system communication delay,handover,and load balancing issues in view of the characteristics of the converged network.As such,this research study holds great significance in this field.The main research work of this thesis is detailed in the following three parts:1.This thesis implemented a converged network simulation platform that was based on the OPNET simulator.The platform examines the comprehensive architecture of a satellite-ground converged network and considers various network modules,such as user nodes,satellite nodes,and ground control center modules,that are designed based on functional requirements.To optimize routing functionality on the simulated network,the simulation platform employs a distributed routing algorithm to analyze different handover scenarios and design varying handover processes.2.We proposes a novel routing handover scheme based on multiattribute decision-making in this thesis.To paint an accurate picture of the satellite-ground converged network’s dynamic nature,a graph structure is employed in this investigation.The weight of the internal link in the graph considers various factors,including signal strength,maximum elevation angle,satellite visibility duration,and the number of available channels.The optimal routing handover scheme is devised by identifying the most suitable route in the graph,taking into account these criteria.In this thesis,we evaluate the benefits of the proposed algorithm and compare its performance with other existing handover strategies with respect to variables such as handover delay and interruption probability.Finally,simulation experiments are carried out to validate the proposed methodology’s effectiveness.