Using Beamforming Antennas For Multiple Access In Wireless Ad Hoc Networks

Using beamforming antennas for multiple access in wireless Ad Hoc networks are studied in this dissertation. With beamforming antennas, two pair of nodes located in each other's vicinity may potentially communicate simultaneously, depending on the directions of transmission .This can increase spatial reuse of the wireless channel .In additional, the higher gain of beamforming antenna allows a node to communicate with other nodes located far away, it has broad application prospects.Based on the brief introduction to the present research in using omnidirectional and beamforming antennas for multiple access in wireless ad hoc networks, the study made in this dissertation mainly includes following three aspects, firstly, as background to wireless medium access control, we describe some of the preliminaries about IEEE 802.11, some key problems in wireless channel access , a basic beamforming antenna model used in our research and the problems under consideration is discussed. Secondly, we focus on descript IEEE 802.11 protocol using beamforming antenna (Beamforming-802.11 Protocol), mainly include directional carrier sensing, channel reservation and Directional NAV (DNAV) table. we also identify several problems with IEEE 802.11 protocol using beamforming antenna. Thirdly, we evaluate the performance of IEEE 802.11 protocol using ideal beamforming antenna and realistic beamforming antenna by Opnet simulation platform, version 8.1, and compare the performance of the protocol with IEEE802.11.After a summary of the dissertation the author also presents and points out the issues which need to be studied further for DMAC protocol.