A Directional Antenna Medium Access Control Protocol for Wireless Ad Hoc Networks

In this paper we propose a Directional Antenna Medium Access (DAMA) protocol that takes advantage of the benefits offered by directional antennas and is best suited for sparsely distributed networks. A large portion of DAMA has been inspired by the IEEE 802.11 MAC, with major enhancements including a new neighbor discovery scheme, and an optimized circular directional transmission of RTS and CTS to prevent the hidden node problem, reduce collisions and decrease node deafness. In addition, a pair of communicating nodes using DAMA simultaneously transmits the circular directional RTS and CTS only to those sectors with neighbors, hence reducing overall communication delay and enhancing throughput. We have compared DAMA with IEEE 802.11 and two recently proposed directional MAC protocols, and results show that DAMA performs better than these protocols in the majority of the scenarios investigated while we point out that the performance depends on the network topology and traffic pattern.