Tree-Based Distributed Multicast Algorithms for Directional Communications and Lifetime Optimization in Wireless Ad Hoc Networks

We consider the problem of maximizing the network lifetime in WANETs (wireless ad hoc networks) with limited energy resources using omnidirectional or directional antennas. Unlike most solutions that use a centralized multicast algorithm, we use graph-theoretic approach to solve the problem in a distributed manner. After providing a globally optimal solution for the special case of single multicast session using omnidirectional antenna, this approach leads us to a group of distributed algorithms for multiple multicast in WANETs using directional antennas. Experimental results show that our distributed multicast algorithms for directional communications outperform other centralized multicast algorithms significantly in terms of network lifetime for both single-session and multiple-session scenarios.