Neighbor discovery and routing schemes for mobile ad-hoc networks with beamwidth adaptive smart antennas

The use of smart directional antennas in ad-hoc networks has recently received much attention since this technology offers a way to optimize power consumption, increase spatial reuse and reduce co-channel interference. Neighbor discovery is an important first step for these self-configured networks because it makes it possible to identify the active nodes surrounding a given node and this information is essential for other higher layer protocols like medium access control, routing and topology control protocols. In this article, we present two algorithms that aim to take full advantage of the capabilities of smart antennas. The first one aims to increase the number of discovered nodes by considering the nodes that are located in the second-hop neighborhood of a node. The second algorithm seeks to reduce the number of hops in a route between source and destination nodes by using the extended range that can be achieved when the nodes are equipped with directional antennas. The results of the simulations have shown a reduction in the end-to-end delay and an increase in the network throughput when the scheme is compared with other reactive routing protocols.