On Multihop Broadcast over Adaptively Duty-Cycled Wireless Sensor Networks

We consider the problem of multihop broadcast over adaptively duty-cycled wireless sensor networks (WSNs) where neighborhood nodes are not simultaneously awake. We present Hybrid-cast, an asynchronous and multihop broadcasting protocol, which can be applied to low duty-cycling or quorum-based duty-cycling schedule where nodes send out a beacon message at the beginning of wakeup slots. Hybridcast achieves better tradeoff between broadcast latency and broadcast count compared to previous broadcast solutions. It adopts opportunistic data delivery in order to reduce the broadcast latency. Meanwhile, it reduces redundant transmission via delivery deferring and online forwarder selection. We establish the upper bound of broadcast count and the broadcast latency for a given duty-cycling schedule. We evaluate Hybrid-cast through extensive simulations. The results validate the effectiveness and efficiency of our design.