An adaptive media access control protocol and system performance of wireless ad hoc network using smart antenna

Abstract

AbstractA smart antenna can increase the number of simultaneous transmissions by reducing interference and improving the throughput performance. In this paper, we propose an adaptive media access control (MAC) protocol that periodically updates neighboring node information in a distributed network, such as a wireless ad hoc network, and uses smart antennas to achieve simultaneous communications by directionality control to neighboring nodes other than those currently communicating. We also verify that the overhead for updating the neighboring node information can be reduced to 15% or less than in conventional schemes and the number of simultaneous communications can be 2 to 3.5 times higher than when using omnidirectional antennas. Furthermore, we considered the effects of the overhead accompanying neighboring node updates, node density, beam width, and moving speed on the communication efficiency when using the proposed MAC protocol. The communication efficiency was improved by controlling the transmission power to shorten the transmission range, lower the node density, and widen the beam width more than by extending the transmission range and increasing the node density. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(3): 50–58, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10140