Adaptive communication for battery-free devices in smart homes

With the ever-growing usage of batteries in the IoT era, the need for more eco-friendly technologies is clear. RF-powered computing enables the re-design of personal computing devices in a battery-less manner. While there has been substantial work on the underlying methods for RF-powered computing, practical applications of this technology has largely been limited to scenarios that involve simple tasks. This article demonstrates how RFID technology, typically used to implement object identification and counting, can be exploited to realize a battery-free Smart Home. In particular, we consider the coexistence of several battery-free devices, with different transmission requirements — periodic, event based, and real-time — and propose a new adaptive and quick-to-learn MAC protocol, called APT-MAC, which dynamically collects information from devices without requiring any a priori knowledge of the environment. Extensive simulations clearly show the benefits of using APT-MAC, which is able to successfully deliver 97.7% of new data samples in complex scenarios, including several high traffic demanding devices such as joysticks and cameras.