Mobile Crowd Wireless Charging Toward Rechargeable Sensors for Internet of Things

Wireless energy harvesting is promising to be a new opportunity to prolong the lifetime of rechargeable sensors in the Internet of Things. However, how to recharge the sensors and manage charging energy is still a problem. Most existing methods are based on robots or vehicles carrying battery packs to charge sensors. They are vulnerable to the sensors distributed in complex terrain and have high hardware maintaining cost. To address this issue, we present crowd-charging (CC), a novel crowdsourcing-based wireless energy charging model for rechargeable sensors. It leverages smart devices carried by users as mobile crowd energy resources (chargers) to provide wireless energy to sensors. The challenge is how to incentivize and allocate mobile users to optimize the total charging quality of all the sensors. Besides monetary energy revenues, we design a bonus game to entertain participated users. We also propose three user allocation algorithms, CC algorithm (CCA), and two improved versions of CCA, i.e., CC and CC. The improved algorithms give great improvement for our model and they have different advantages suitable for different situations. We conduct extensive simulations and demonstrate the effectiveness of our algorithms with numerical results.