Traditionally, medium access control (MAC) protocols are designed for nodes, which are equipped with omni-directional antennas. Some disadvantages of using omni-directional antennas are poor data throughput, lower network and power efficiency due to interferences resulted by the transmission of packets in undesired directions. Recently, research community has showed keen interest in investigating directional antennas for wireless networks. This thesis studied the IEEE 802.11 MAC protocols using directional antennas and their impact on the performance of wireless networks. Three types of MAC protocols were implemented using the widely-popular discrete event simulator OPNET Modeler 17.1. Their performance was studied for single-hop wireless networks with various network topologies. For this, a node model using directional antennas was also developed in Opnet. Simulation results demonstrated that the MAC protocols using directional antennas can significantly increase the data throughput in wireless networks.
