PANDA: An Approach to Improve Flooding Based Route Discovery in Mobile Ad Hoc Networks

In this paper we present an approach to improve the performance of flooding-based route discovery in mobile ad hoc networks(MANETs) using positional attributes of the nodes. These attributes may be geographical, power-aware, or based on any other quality of service(QoS) measure. Flooding technique is often used for route discovery in on-demand routing protocols in MANETs such as Dynamic Source Routing(DSR) and Ad hoc On-demand Distance Vector(AODV) routing. To avoid the problem of wireless broadcast storm, the Random Rebroadcast Delay(RRD) approach was introduced in the process of route discovery in these protocols. We identify the “next-hop racing” phenomena due to the RRD approach in these protocols and propose a Positional Attributes based Next-hop Determination Approach(PANDA) to address this problem. We assume each node knows its positional attributes, and an intermediate node can learn the positional attributes of its previous-hop node via the received route-request message. Based on the attributes such as the relative distance and the estimated link lifetime, an intermediate node will identify itself as good or bad candidate for the next-hop node and use different rebroadcast delay accordingly. By allowing good candidates to always go first, our approach will lead to the discovery of better end-to-end routes in terms of the desired quality of service metrics. Through simulation we evaluate the performance of our proposal using path optimality, endto-end delay and delivery ratio. Our approach can also be applied to discover routes based on other constraints like power conservation. Simulation results show that our approach can help find data paths with only 15%~40% energy consumption compared to the RRD approach at a moderate cost of increased routing messages.