A practical medium access scheme for wireless ad hoc networks employing ESPAR antennas

Cochannel interference limits the capacity of wireless ad hoc networks. Adaptive antennas can mitigate cochannel Further interference by steering the beam in an appropriate direction. In this paper, we consider the application of an electronically steerable parasitic array radiator (ESPAR) antenna at every terminal in a packet-oriented wireless ad hoc network. A practical medium access scheme is used for the exchange of data packets where the terminals employ an opportunistic beamforming and refrainfrom sending a packet if too much interference is detected. The channels are modeled as multiple-inputlmultiple-output channels, being time invariant during a data packet transmission. In computer simulations, we investigate the transpnrt capacities that can be achieved with the proposed scheme and we analyze the transmission failure events.