Adaptive Scan-based Asynchronous Neighbor Discovery in wireless networks using directional antennas

Directional antennas provide tremendous potential for improving the performance of wireless networks. However, the exploitation of this potential requires lots of efforts at the medium access and network layers, among which neighbor discovery serving to set up links between nodes and their neighbors, turns out to be an important issue. In this paper, we propose a practical neighbor discovery protocol called Scan-Based Asynchronous Neighbor Discovery (SBAN) protocol, dealing with the problem of neighbor discovery in large-scale asynchronous wireless networks using directional antennas. The main contribution of this paper includes a slow Scan-Based Hello Mechanism and a fast Reply Mechanism. Besides, we derive an effective self-adaptive strategy, which aims at automatically adjusting the parameter settings in order to maximize the number of neighbors discovered during a fixed running time. Additionally, we build a mathematical model to verify our intuition and use OPNET simulations to numerically implement our model. Simulation results reveal that our new protocol always requires less time to discover the whole neighbors than that of the previous asynchronous algorithms.