Visible Light Synchronization for Time-Slotted Energy-Aware Transiently-Powered Communication

Energy-harvesting IoT devices that operate without batteries paved the way for sustainable sensing applications. These devices force applications to run intermittently since the ambient energy is sporadic, leading to frequent power failures. Unexpected power failures introduce several challenges to wireless communication since nodes are not synchronized and stop operating during data transmission. This paper presents a novel self-powered autonomous circuit design to remedy this problem. This circuit uses visible-light communication (VLC) to enable synchronization for time-slotted energy-aware transiently powered communication. Therefore, it aligns the activity phases of the batteryless sensors so that energy status communication occurs when these nodes are active simultaneously. Evaluations showed that our circuit has an ultra-low power consumption, can work with zero energy cost by relying only on the harvested energy, and supports efficient intermittent communication over intermittently powered nodes.