Wireless Power Transfer for Bluetooth Low Energy Based IoT Device: an Empirical Study of Energy Performance

Radio Frequency (RF) Wireless Power Transfer (WPT) is a prospective technology promising to enable unintermittent and maintenance-free operation of IoT devices. In this paper, we shed some light on the energy performance of the state-of-the-art RF-WPT in Bluetooth Low Energy (BLE) and IoT hardware platforms, specifically the Powercast P21XXCSREVB and the Texas Instruments CC2652R1 multi-radio protocol system-on-chip. For this, we first study the energy consumption of the CC2652R1 communicating over BLE technology in advertising mode, and the effect of the different BLE configuration parameters, such as transmit power, the number of channels, advertising interval and size of advertising packet, have on the energy consumption. Next, we investigate how much energy can be harvested and stored in the P21XXCSR-EVB, when RF transmission is from a dedicated WPT equipment. Finally, we integrate both elements to instrument a WPT-powered IoT device communicating over BLE, and investigate its energy consumption. Our results show the feasibility of instrumenting a WPT-powered IoT device today, while revealing some challenges and limitations of this approach. We believe that our results can be a reference for new designs, further optimizations and analytic/simulation models for WPT-powered IoT.