Energy efficient adaptation of multicast protocols in power controlled wireless ad hoc networks

In this paper a methodology for adapting existing wireless ad hoc network protocols to power controlled networks is presented. Wireless nodes are assumed to have transmission power control with m discrete levels, and a clustering scheme is used in the adaptation to be energy efficient. Clusters are formed among the nodes in a distributed self-organized manner so that each node is a member of some cluster and within a cluster, each node can reach any other node with appropriate power level. Each cluster has a designated head node which acts as forwarding agent for its members and these head nodes from a supernode topology. We adapt an ad hoc network multicast protocol by executing it on this supernode topology. Multicast data will move from the sender to its cluster head, then along the supernode topology according to the results of the chosen multicast protocol, and finally from cluster head to receivers within their clusters. At every step, nodes use appropriate power level, 1/spl les/j/spl les/m, to reach all the intended recipients. For more balanced way of depleting energy in the network, nodes take turn to become cluster heads. We applied our technique to ODMRP and the experiment shows significant energy reduction.