On minimizing the broadcast redundancy in duty-cycled wireless sensor networks

Broadcast is a fundamental activity in wireless sensor networks (WSNs) and many problems related to broadcast thus have been formulated and investigated in the literature. Among them, the minimum-transmission broadcast (MTB) problem, which aims to reduce the broadcast redundancy, has been well studied in conventional wireless ad hoc networks, where network nodes are assumed to be active all the time. In this paper, we study MTB problem in duty-cycled WSNs (MTB-DC problem) where sensor nodes operate under active/dormant cycles; then propose a novel scheme to solve it. The proposed Level-Based Approximation Scheme (LBAS) first identifies the minimum sets of forwarding nodes for all time slots. Then the broadcast backbone is constructed efficiently through a two-stage traversal which completely exploits duty transmission of forwarding nodes when connecting them to the broadcast source. We have also conducted extensive simulations to evaluate the performance of our proposed scheme. The results indicate that our scheme outperforms existing ones significantly.