Research On Transport Protocols Of Time-Divided And Space-Divided Inter-satellite Link Network

As the development of communication technology and the change of our thinking way,network is playing more and more important role in our life.In compare with territorial network,the research of space network starts later but develops rapidly.The main differences between space network and territorial network are: inter-satellite links in a space network are much longer than links between nodes in a territorial network,resulting that the error rate is much higher than that in territorial network;The topology of a space network changes fast so that ISLs convert very frequently;The capacity of satellites is limited and cannot burden algorithms with high complexity;Satellites in constellation move periodically.The main role of MAC layer,which is the foundation of satellite network,is to manage and coordinate shared spectrum resource,so the performance of MAC layer influences the performance of the whole network.We focus on the time slot schedule of ISLs and media access in satellite constellation in this paper.The structure of the paper is,Study of satellite constellation MAC layer access scheme based time-slot.we analyze the polling access using time-slot allocation scheme to get a MAC access protocol taking count of communication and measurement,then we simulate the protocol with MATLAB to check the network performance.Study of satellite constellation MAC layer access scheme based contend.we analyze the possibility of adapting IEEE802.11 MAC layer to satellite constellation by adapting the inter frame intervals and contend window so that the contend-based MAC access scheme can applying to space networks.In the end of our paper,we simulate time-slot allocation MAC access scheme with NS2(Network Simulator Version 2)in which we establish node model and transmission model applying each scheme,then we analyze the performance of the network.