Research On The Multichannel MAC Protocol Based On Directional Antenna In ADHOC

One of the traditional MAC protocols used in wireless ad hoc networks isDistributed Coordination Function IEEE802.11(DCF).In such protocols, nodes areallowed to access the channel without any base station and omni-directional antennasare used for packet transmission. The main problem in IEEE802.11DCF is theexistence of silent area which leads to channel spatial reuse reduction and usingdirectional antennas at the nodes can battle this problem. However, using directionalantennas itself leads to other problems such as new hidden terminal and deafnessproblems. This paper proposed a one-channel MAC protocol based on directionalantenna, and through designing directional network allocation vector table, we achieveparallel transmission of multiple pairs of nodes in a single channel.Then, we propose anew multichannel MAC protocol based on Direct Sequence Spread Spectrum techniquein which directional antennas and CDMA codes are used to specify the channels fordifferent users. In the proposed protocol, a common control channel is used for datatransmission. Simulation results show that the proposed protocol, by using even lowernumber of codes, improve the network throughput and achieves higher spatial reuse ofwireless channel compared with802.11DCF, or other traditional protocols such asDMAC protocol.