Collision-Aware Neighbor Discovery with Directional Antennas

The integration of directional antennas in ad-hoc networks offers tremendous potential for improving the overall network performance. However, the use of directional antennas makes the neighbor discovery process difficult due to the asymmetric nature of the directional gain. Recently, several neighbor discovery schemes have been proposed in this context. But the effect of packet collisions has been is ignored in these schemes. In this paper, we propose a novel collision-aware neighbor discovery scheme based on a two-way handshaking mechanism. We introduce a collision resolution mechanism that enables a faster convergence of the neighbor discovery process. We also derive a relation to compute the optimal contention window size for collision resolution. We then propose an upgraded version (i.e., peer-assisted node discovery) of the scheme involving cooperation among the neighbor nodes. Simulation results demonstrate that the proposed scheme achieves a significantly faster network-wide neighbor discovery than existing schemes.