A Novel Approach for Efficient Route Request Flooding in MANETs with Directional Antennas

In recent years, using directional antennas to reduce the amount of interference and collisions in mobile ad hoc networks has become more and more popular. Due to the problem of broadcast storm caused by flooding route requests, a novel route request flooding approach called Hexagonal Flooding Strategy (HFS) for Ad Hoc networks using directional antennas is introduced in this paper. With directional antennas, the flooding of route request packets is limited among selected forwarding nodes. By constructing a honeycomb pattern, the forwarding nodes which form the honeycomb vertices are selected. The transmissions between forwarding nodes which form the honeycomb edges are reshaped according to certain rules to optimize flow directions. Through simulations we evaluate the performance of HFS using route discovery success rate, average number of nodes and forwardings involved in the route discovery process. Simulation results show that HFS can: (a) improve route discovery success rate, (b) reduce the number of nodes and forwardings involved in the route discovery process. Keywords—Ad Hoc Network; Broadcast storm; Directional Antennas; Route Request Flooding; Honeycomb Strategy