Is WiFi suitable for energy efficient IoT deployments? A performance study

Nowadays billions of connected objects are publishing sensed data everyday and this number is expected to grow exponentially. In many cases IoT objects are battery powered and need to be energy efficient as the most important requirement in order to reduce battery replacement costs. Conversely, WiFi is still the predominant wireless technology, deployed in almost all everyday life environments and thus the easiest network type on top of which build an IoT ecosystem. In this paper we analyze the energy efficiency of constrained devices using WiFi, which is certainly a widely accepted technology, although not specifically designed for constrained devices. To perform our test, we use the ESP-12 SoC, which gained interest recently due to its low cost and capabilities. We test its performance by studying the battery duration of such device under different connectivity conditions, varying its authentication policy, its battery type and its duty cycle. We report results from laboratory tests and show that such devices can be an efficient compromise for low-cost low-energy scenarios using WiFi.