Simulation study for Mobile Ad hoc Networks Using DMAC Protocol

This paper addresses the issue of deafness problem in Mobile Ad Hoc Networks (MANETs) using directional antennas. Directional antennas arebeneficial for wireless ad hoc networks consisting of a collection of wireless hosts. A suitable Medium Access Control (MAC) protocol must be designed to best utilize directional antennas. Deafness is caused whentwo nodes are in ongoing transmission and a third node (Deaf Node) wants to communicate with one of that node. But it get no response because transmission of two nodes are in process. Though directional antennas offer better spatial reuse, but this problem can have a serious impact on network performance. A New DMAC (Directional Medium Access Control) protocol uses flags in DNAV (Directional Network Allocation Vector) tables to maintain information regarding the transmissionbetween the nodes in the network and their neighbor’s location. Two performance matrices have been used to show the impact of New DMAC algorithm on Deafness problem using simulator. These are RTS Failure Ratio and RTS Retransmission due to timeout