Study Of Mobile Ad Hoc Networks Using Directional Antennas

Mobile Ad hoc Networks (MANET) is infrastructureless network .It set up by the nodes which can move and link arbitrarily with no centre node in topology, extensively apply in all quick arrangements, dynamic situation ,such as the military ,an emergency correspondence, temporary communication ,etc. Previous research on the Ad hoc network almost aim at omnidirectional antenna of all receivers and transmitters ,or as a default attribution .In my thesis ,firstly I describe the advantages of the directional antenna at many aspects which including spatial division multiple access( SDMA), the antenna gain, anti- interference etc. and analyze the possibility about the directional antenna used for the ad hoc networks, secondly I study its multiple access and routine protocols using the directional antenna. And compare the protocol difference and network" performance between omnidirectional and directional antenna in particular environment. The directional routing protocol DS_DSR put forward by the author is the improvement of the current protocol DSR , complete routine discovery and maintenance by directional neighbor nodes routing table, source routing and directional steering.The research discovers the application of the directional antenna, compare the omnidirectional antenna can increases the networks' total throughput, obviously reduces the co_channel interference (CCI), multiple access interference ( MAI), enlarges the nodes "signal and interference to noise ratio( SINR), and because of the high gain of directional antenna can realize the communication with farther distance and less jump, end to end delay can decrease deeply, simultaneously, security of networks can be improved partially, the node energy also can be saved easily by power control.For the sake of the convenient network simulation, I select a same framework in my MAC and routine protocols' simulation, that is IEEE802.11 standard built in soft tool OPNET, by designing my network node model and directional antenna model, and the improvement of the current protocols, I realizes the evaluation of my special networks.