Date Added: May 2012
In this paper, the authors address a tough challenge of achieving two opposing goals: ensuring long lifetimes and supporting short end-to-end delays in sensor networks. Obviously, sensor nodes must wake up often to support short delays in multi-hop networks. As event occurs seldom in common applications, most wake-up are useless: nodes waste energy due to idle listening. The authors introduce a set of solutions, referred to as LETED (Limiting End-To-End Delays), which shorten the wake-up periods, reduce idle listening, and save energy. They exploit hardware features of available transceivers that allow early detection of idle wake-up periods. This feature is introduced on top of their approach to reduce idle listening stemming from clock drift owing to the estimation of run-time drift.