NOVEL PROTOCOLS TO IMPROVE BROADCASTING EFFICIENCY OVER SWITCHED SINGLE BEAM ANTENNA IN A MOBILE AD-HOC NETWORK

by VOGETY, SASIDHAR

In order to fully exploit the benefits of directional communication at upper layers, it is of paramount importance to investigate the issues related to directional broadcasting. Directional antennas offer an increased spatial reuse and a larger coverage range as transmitted power is concentrated in a small angular region. However, in a switched single beam antenna model broadcasting is achieved by sequentially steering the antenna beam across all pre-defined directions resulting in a sweeping delay. In this thesis we study suggested techniques to alleviate broadcast storm problems in ad hoc networks, point out their shortcomings, and propose two new schemes, namely, the New Enhanced Directional Flooding (NEDF) and the Probabilistic Relay Broadcasting (PRB). We thoroughly compare the performance of these protocols with present directional broadcast schemes including omni directional flooding over six, twelve and eighteen antenna beam models. The results indicate that directional broadcasting provides excellent connectivity in the regions of sparse density as compared to omni directional broadcasting. Finally, the proposed schemes are shown to outperform the existing schemes with respect to connectivity, latency and redundancy over a wide spectrum of network topologies and node densities.