Survey and Taxonomy of Duty Cycling Mechanisms in Wireless Sensor Networks

Motivated by stringent power constraints, duty cycling - the practice of turning a mote's radio on and off to conserve energy - has become a fundamental mechanism in the design of Wireless Sensor Networks. Because of its importance, a variety of approaches to duty cycling have emerged during the last decade and are being now proposed with increasingly ambitious goals, such as achieving ultra low duty cycles as low as 0.1%. Such propositions differ mostly in their reliance on nodes' synchronization, which, in turn, translates into different hardware requirements and implementation complexity. However, duty cycling may also differ in other aspects as topology dependency, network density requirements and increase in end-to-end delay. This paper organizes the most important proposals into a taxonomy and provides insights into their strengths and weaknesses in relation to important characteristics of applications, mote's hardware and network deployments.