Several centralized and distributed algorithms have been recently proposed to maximize the multicast lifetime for directional communications in wireless ad-hoc networks. Their performance has been studied by simulations; however, their theoretical performance in terms of approximation ratio is still unknown. In this paper, we use the graph theoretic approach, by the first time, to derive the upper bound of the approximation ratio in an analytical expression for these algorithms. We have also discovered that these upper bounds are finite numbers. Based on this analysis and some key observations, we present a new distributed constant-factor approximation algorithm in order to achieve a higher performance. This effort is validated by our simulation studies. Categories and Subject Descriptors C.2.1 [Computer-Communication Networks]: Network Architecture and Design ? Wireless communication; F.2.2 [Analysis Algorithms and Problem Complexity]: Nonnumerical Algorithms and Problems ? Computati...
Song Guo, Oliver W. W. Yang, Victor C. M. Leung