Minimum-delay and energy-efficient flooding tree in asynchronous low-duty-cycle wireless sensor networks

A tree-based topology is often used to flood packets from the sink node in wireless sensor networks (WSNs). Therefore, flooding tree construction is an important and fundamental problem in WSNs, and has been extensively investigated in the literature. However, we note that the flooding tree construction problem in asynchronous low-duty-cycle WSNs has not been sufficiently investigated in existing work. In this work, we focus our investigation on minimum-delay and energy-efficient flooding tree construction considering the duty-cycle operation and unreliable wireless links. We formulate the problem as a undetermined-delay-constrained minimum spanning tree (UDC-MST) problem, where the delay constraint is known a posteriori. We design a distributed heuristic algorithm, named MDET, to solve the problem. Through extensive simulations, we demonstrate that MDET achieves a very good balance between flooding delay and energy efficiency.