Abstract: Smart antennas technology is now regarded as one of the hot-point research areas in mobile communications. However, its application to the mobile or portable nodes receives little attention. The approach to employ smart antennas in mobile Ad Hoc network nodes is presented. The emphasis of smart antennas on the performance of the multiple access protocol is discussed. An adaptive directional CSMA/CA (AD-CSMA/CA) protocol for medium access control(MAC) layer is proposed. In Ad-CSMA/CA, RTS/CTS dialogue and virtual carrier sense are combined with the use of smart antennas. Simulations show that the proposed AD-CSMA/CA protocol together with Smart antennas provide higher channel utilization.

Key words: mobile Ad Hoc network, smart antennas, multiple access protocol