Analysis of multipath routing for ad hoc networks using directional antennas

Ad hoc networks with directional antennas have become an active research topic because of the potential capacity increase through spatial reuse. Currently, researchers have attempted to apply conventional ad hoc routing protocols (e.g. DSR, AODV) to this type of network. The routing schemes are typically based on the shortest path metric. However, such a routing approach often suffers long transmission delay and frequent link breakage at the intermediate nodes. This is caused by a unique feature of directional transmission commonly known as "deafness" (Choudhury, R. et al., 2002). To address this problem, we have introduced a new multipath routing scheme to explore the advantage of spatial reuse for reducing per hop medium access delay. An analytical and numerical analysis of the directional ad hoc network behavior is presented, along with an introduction to our multipath routing scheme and a discussion of the effectiveness of this scheme in balancing per-hop delay and hop-count for packet forwarding. Simulation results demonstrate a clear performance improvement by using multipath routing for directional ad hoc networks.