Research On Efficient Link Handover Strategy In The Broadband LEO Satellites Network

The low-orbit satellite network has become a key component of the next-generation air-space-ground integrated communication system under the advantages of low satellite manufacturing cost,wide network coverage and flexible deployment,providing broadband satellite communication services to the world.The lower orbital height and faster running speed of the low-orbit satellites results in dynamic changes in the state of some inter-satellite links and inter-satellite-to-earth links,making it difficult for the inter-satellite links and satellite-to-ground links to maintain long-term connections.This paper focuses on the problem of inter-satellite link handover in the cross seam of the low-orbit polar orbit network and the problem of feeder link handover between satellites and ground station.Firstly,this paper introduces briefly the development background of low-orbit satellite networks,analyzes the practical significance of the development of satellite networks from the perspective of historical progress,analyzes and studies the current low-orbit satellite constellations and satellite handover strategies.The inter-satellite link,the satellite-ground link,and the network architecture of the satellite communication system are introduced.On this basis,the dynamic handover of the loworbit satellite network is discussed,the key points of the problem are clarified,and the theoretical basis for the handover strategy is provided.Subsequently,this paper takes the Global Multimedia Satellite Network as the research scene and proposes a Star Cross Looping Link-Building Strategy for the problem of cross seam in the satellite network.The Global Multimedia Satellite Network uses laser for communication between satellites.Due to power limitations,the laser communication distance between satellites is limited to 800km?4500km.Based on the actual capabilities of the laser terminal,this paper analyzes the allowable linkbuilding distance between satellites in the cross seam and constructs multiple crosslink-building areas.With the network capacity as the optimization goal,the loop algorithm is used to search for the optimal cross-link-building areas,and the start latitude set of each cross-link-building area is recorded,and the start latitude set is used to realize the intelligent link-building of cross seam.The simulation results show that compared with other link-building strategies and non-link-building strategies,this linkbuilding strategy can reduce transmission delays by 30% to 60%.Next,this article proposes a feeder link handover strategy based on global service distribution to address the frequent handover of feeder links in the Global Multimedia Satellite Network.When distributing the feed links,the ground stations are prioritized according to the regional business volume by referring to the existing business distribution on the ground,and the landing satellites are assigned in turn.In the process of distribution,three parameters including satellite viewing time,feed link rate and onboard load were comprehensively considered.While optimizing the network capacity between the satellite and ground,download the data that needs to be landed on the satellite as much as possible to improve the utilization rate of the feed link.Simulation results in STK and Matlab based on actual business scenarios show that this strategy can increase network capacity and increase the amount of landing data by about 70%,which has reference value for handover feed link in actual application scenarios.