The Study And Simulation Of NEMO Oriented Satellite Constellation Communication Network

In order to meet the future requirements of the military satellite communication systems for our army, in this thesis, we do some research on the LEO (Low Earth Orbit) satellite constellation communication network based on the network mobility (NEMO), and do a lot of simulation.Firstly, the develop history of the military satellite communication system is introduced in this thesis. The trend that the satellite communication system will support the network mobility is indicated. Using the architecture of Iridium system for reference and integrating the mobile network technology, an LEO satellite constellation network communication system named "New Satellite" which contains 48 satellites is designed. Then we use simulation tools such as NS2,STK and Savi simulate the transmit delay,throughput,global coverage of "New Satellite" system. The simulation result shows that "New Satellite" can make complete coverage of the Earth and have a low delay date transmitting.Then the theory about handoff of the LEO satellite network is introduced in this thesis. In order to optimize the handoff procedure of NEMO basic support protocol, mobility management rules of "New Satellite" system are presented. The rules include space/terrene segment mobility management and user segment mobility management, relevant protocols and models are also designed. In the part of space/terrene segment, a cross satellite handoff control scheme which is based on local authentication is designed. In the part of user segment, a handoff control scheme based on mapping router (MapR) is designed. The simulation result shows that the handoff control scheme based on MapR can reduce more than 1/2 on the handoff delay on average. This method can improve the transmit delay performance commendably about our "New Satellite" system.