PD-MAC: Design and Implementation of Polling Distribution-MAC for Improving Energy Efficiency of Wireless Sensor Networks

Abstract

Reducing the energy consumed by MAC layer in Wireless Sensor Networks (WSNs) can lead to major performance improvements. A number of previous scholars have focused on optimizing the energy usage in WSN through adjusting the wake-up intervals, duty cycles and polling intervals. Some of the protocols focusing on dynamically adjusting the duty-cycle or channel polling intervals based on the traffic arrival patterns include SCP-MAC, RIMAP, AS-MAC, MCAS-MAC, LAD and self-adaptive wakeup scheduling scheme. This paper aims at improving the energy efficiency of MAC protocols by studying the influence of using ‘polling interval distributions’ rather than ‘polling intervals’ for different traffic types. The influence of using deterministic and exponential polling interval distributions is illustrated by developing an asynchronous MAC protocol PD-MAC (Polling Distribution-MAC). Two types of traffic: deterministic and exponential has been used for evaluating the performance of PD-MAC. TinyOS platform for mica2 motes has been used for implementation. The impact of varying message generation intervals and polling intervals, over the delay and energy performance of PD-MAC has been studied. Results have revealed that PD-MAC with exponentially distributed polling intervals results in improved energy performance in contrast to PD-MAC with deterministic polling intervals. Similarly, PD-MAC with exponentially distributed polling intervals is shown to outperform established MAC protocol SCP-MAC. Hence, the major contribution of PD-MAC is to introduce an energy efficient MAC solution for WSN applications operating under different traffic patterns without the need of extensive memory usage or computational complexity.