Satellite Constellation Design And Evaluation In Satellite Internet Of Things

Satellite Internet of Things(SIo T)provides seamless coverage and continuous communication for ground users by virtue of the unique advantages of ground Internet of things(Io T)and the satellite constellation of all-weather,all terrain and low delay.However,a small number of satellites can not meet the huge user demands.Meanwhile,the satellite and ground Io T nodes are dynamic.The satellite constellation design and evaluation can realize the continuity and reliability of the network with the least satellite resources and reasonable orbit configuration considering the dynamic nodes and links.Therefore,in this thesis,the satellite constellation design and evaluation in SIo T are deeply studied.The main research content is divided into the following two aspects:(1)In the user intensive SIo T,massive user access will produce huge user demands.However,the limited satellite resources are difficult to meet all user needs,which limits the user quality of experience(Qo E).Therefore,a constellation design scheme with Qo Eaware is proposed to generate the best Qo E satellite constellation.Among them,an intelligent algorithm named multi level tabu search algorithm(MLTS)is proposed to automatically generate the satellite orbit with the best Qo E.The simulation results show that the designed satellite constellation can not only maximize the user's Qo E,but also automatically adjust the constellation design scheme according to the user's distribution.(2)In Ocean-oriented Satellite Internet of Things(OSIo T),the mobile marine equipment and changeable marine environment lead to unstable nodes and discontinuous communication links,which affect the reliability of information transmission.Therefore,a constellation reliability evaluation scheme is proposed,which can evaluate the reliability of satellite constellation by quantifying the survivability and link survivability of OSIo T.In particular,the proposed reliability evaluation algorithm(REA)ensures the best evaluation result under the limitation of satellite power consumption.The simulation results show that the proposed reliability evaluation scheme can not only obtain the best performance of satellite survivability,but also ensure the optimal evaluation results of link survivability.