Research On Multi-service Handover Technology In Heterogeneous Satellite Networks

With the development of the global communication industry,the communication needs of terminal is increasing,and the types of services are also increasing.At the same time,various high-dynamic terminals have appeared,which have put forward higher requirements for communication technology.As an important part of the global communication system,the satellite network composed of single-layer LEO,MEO or GEO satellites can no longer meet the complex communication needs.Satellite heterogeneous networks that integrate all layers of satellites have become the future development trend.Due to the relatively high speed movement between the satellite and the mobile terminal,and the limited resources on the satellite,the terminal needs to handover between the satellites to obtain an uninterrupted communication service.The performance of the handover algorithm directly affects the quality of the user s call.In the GEO/LEO satellite heterogeneous network scenario,this paper analyzes and summarizes the existing satellite handover technology,and conducts in-depth research on the handover in the satellite network,and designs different handover algorithms for different service types.This paper aiming at that it is difficult to guarantee the quality of service for non-delay-sensitive services and the problem of unbalanced load between LEO satellites,in the GEO/LEO satellite heterogeneous network,the signal-to-noise ratio is used as the indicator of handover,and the bandwidth and transmission cost are considered.A variety of network attributes,such as satellite load conditions,propose a handover decision algorithm based on load balancing and QoS(Quality of Service)guarantee.The algorithm takes into account the global traffic distribution,sets the regional traffic dynamic mapping factor,effectively adjusts the proportion of satellite load conditions in the handover decision,and improves the utilization of satellite resources.In order to simulate the performance of the algorithm,a time-scheduled satellite resource heterogeneous network radio resource management simulation platform is built,and compared with the signal strength based handover decision algorithm and multi-attribute handover decision algorithm.It is verified that the algorithm can effectively improve the performance of system throughput,handover blocking rate and network load balance.Aiming at the problem of high delay rate of delay-sensitive service switching caused by high-speed motion of mobile terminals,this paper proposes a speed-aware TEG-based handover prediction algorithm by analyzing terminal motion characteristics and constructing terminal motion model combined with satellite ephemeris information.According to the satellite's coverage of the terminal,a directed graph is generated,and the inter-satellite switching is modeled as the shortest path problem of the directed graph.Different weights can be set for different switching strategies,and the subgraphs are updated according to the satellite load condition and the position coordinates of the terminal.The simulation results show that the proposed algorithm can be applied to terminals with various motion speeds,can better adapt to network load changes,and has higher prediction accuracy for high-speed motion terminals.