Esense: communication through energy sensing

In this paper, we present Esense: a new paradigm of communication between devices that have fundamentally different physical layers. The same communication framework also works between devices that have the same physical layer, which are out of communication range but within carrier-sense range. Esense is based on sensing and interpreting energy profiles. While our ideas are generic enough to be applicable in a variety of contexts, we illustrate the usefulness of our ideas by presenting novel solutions to existing problems in three distinct research domains. As part of these solutions, we demonstrate the ability to communicate between devices that follow two different standards: IEEE 802.11 and 802.15.4. We build an ``alphabet set'': a set of signature packet sizes which can be used for Esense. For this, we take a measurement based approach by considering WiFi traces from actual deployments. We then analyze the channel activity resulting from these traces and build an appropriate alphabet set for Esense communication. Our results show that we could potentially construct an alphabet of size as high as 100; such a large alphabet size promises efficient Esense communication. We also validate this alphabet set via a prototype implementation, and show that effective communication is indeed feasible even when both sides use different physical layers.