Energy Efficient Protocols for LLNs - Metrics and Measurements

Abstract

Energy efficiency is arguably the primary concern of most new propositions for the Industrial Internet of Things (IIoT) focusing on Low Power and Lossy Networks (LLNs), be it novel or improved protocols or new applications. While simulations are mostly used to evaluate new approaches, they might only approximate the energy consumption, generally done via abstract metrics that are assumed to correlate directly with actual energy usage. We analyze the behavior of two different Internet of Things (IoT) development boards in detail and in a second step operating in realistic scenarios, comparing two different multicast routing protocols and various configurations. While focusing on the IEEE 802.15.4/6LoWPAN, we show that the actual energy consumption of real devices is considerably more complex than simulations are able to model, and can drastically change depending on device type and hardware configuration. We further analyze prominent metrics that are, according to our results, able to estimate energy consumption, show their limitations and how their accuracy can be improved.