Research On Ad Hoc MAC Protocol Of Directional Antenna

In Ad Hoc networks, status of each node is fair, there is no central node, and the multi-hopscommunication can realized. The multi-hops shared communication makes channel access complex,so the data collision is very frequent. Therefore it needs to improve the MAC protocol to coordinatenodes access to ensure that node can be fair and orderly access to the wireless channel. Due to thehigher antenna gain, higher channel utilization and energy utilization, it has attracted attention ofpeople. Meanwhile some of the MAC protocol of directional antenna have been arising.This thesis discusses the features and applications of Ad Hoc network, analyses theadvantages and disadvantages of the classic MAC protocols. Considering the higher throughput andbetter overall performance of DMAC, this thesis researches DMAC protocol emphatically. Basedon analysing of deafness problem, new hidden problem, HOL problem and backoff problemwithin DMAC protocol, this thesis proposes a new DBTC-DMAC protocol based on DSPSAalgorithm and a new backoff mechanism.Aiming at deafness problem and new hidden problem, DBTC-DMAC protocol caneffectively solve deafness problem and hidden terminal problem of antenna gain asymmetric.With DBPS algorithm, DSPSA algorithm, which is based on the DNAV packet delivery orderly, canfurtherly solve the HOL problem and improve throughput. The new backoff mechanism, which isbased on backoff event, can avoid the unnecessary waste of network resources and improve thenetwork throughput, latency and packet loss rate.The simulation experiment results show that the improved DMAC protocol gets obviousimprovement in network throughput and channel utilization.