An Energy-Efficient MAC Using Dynamic Phase Shift for Wireless Sensor Networks

In this paper, we propose a novel dynamic phase shift (DPS) scheme for energy efficiency in multi-hop wireless sensor networks. The DPS algorithm allows not only a receiver to shift its wake-up schedule dynamically to a sender´s wake-up schedule, but also a sender to shift its wake-up schedule dynamically to a receiver´s wake-up schedule to reduce the energy waste that occurs during a rendezvous period of asynchronous duty cycle scheme. Based on the DPS algorithm, we also propose DPS-MAC, in which a collision avoidance scheme and a delay reduction technique have been included. Furthermore, we design the DPS-MAC to cooperate with the network layer for energy saving of the overall network. Simulation results show that the proposed DPS-MAC achieves better energy efficiency and improved latency compared to a conventional asynchronous MAC protocol.