An Energy-Efficient broadcasting scheme for unsynchronized wireless sensor MAC protocols

In the past couple of years, many Energy-Efficient Medium Access Control (E²-MAC) protocols for all kinds of wireless networks have been proposed. Many of them are based on Preamble Sampling (also referred-to as Low Power Listening) with asynchronous wake-up schemes and brief periodic polls for channel activity. Although these protocols have proven to almost reach the theoretic lower bounds of energy-efficiency in case of unicast point-to-point transmissions, they yet lack an efficient solution to implement a one-hop broadcast and a network-wide broadcast mechanism. This paper proposes an energy-efficient broadcasting scheme for use in E²-MAC protocols with asynchronous duty cycles. We integrate the technique into the asynchronous wireless sensor MAC protocol WiseMAC and show that the technique is superior to the existing WiseMAC broadcast mechanism with respect to packet delivery rate, latency and energy consumption through simulation study and experiments with a real-world prototype implementation.