LAUSR

In this article, the authors discuss new trends in powering pervasive computing systems and review what we have learned in the last 15 years of building such systems. Major advances in cloud computing, RF, power harvesting, and networking have enabled new asymmetric architectures that reduce our reliance on batteries. Although the authors see a slowing of Moore's law, and although battery density technology has remained relatively flat, there are still opportunities in improving energy efficiency. This article is part of a special issue on pervasive computing revisited.