Springer-Verlag Lecture Notes in Computer Science, vol. 4558, pp. 635-644, Jul. 2007
Kwonseung Shin, Kwangjin Park, Min Young Chung, and Hyunseung Choo
A mobile ad-hoc network  is a set of mobile nodes acting as routers in infrastructureless networking situations. In ad-hoc environments, to extend the lifetime of wireless mobile hosts, energy-efficient ad-hoc routing protocols must be designed. However, in conventional reactive ad-hoc routing, the route discovery operation is triggered whenever a source node has packets to send to a certain destination, but has no route information for the destination. Intermediate nodes, then, repeatedly broadcast the message until it is received by all nodes. This route discovery process could result in excessive drain of limited battery power and increase collisions in wireless transmission. In this paper, we propose an energy efficient route discovery scheme using the K-hop Pre Route Request (PRREQ) message which is only flooded within K hops from the source node. This reduces the number of nodes that participate in the route discovery process. Our empirical performance evaluation, which compares our proposed scheme to the conventional reactive adhoc routing schemes, demonstrates that proposed enhancement reduces energy consumed in the route discovery procedure by about 27% when each node initiates a new route at a rate of 0.05/sec.