Crowdsourcing in Wireless-Powered Task-Oriented Networks: Energy Bank and Incentive Mechanism

Wireless energy transfer (WET) is emerging as a promising paradigm that provides sustainability for pervasive battery-powered devices to complete various tasks. Due to high attenuation of WET, it is crucial to design new architecture that conserves energy while guaranteeing task completion. In this paper, we propose an energy bank-based crowdsourcing framework and an incentive mechanism for energy conservation in wireless-powered task-oriented networks. An employer device outsources the whole or a part of its task to several worker devices and pays them energy as reward. Through energy-service trading, the employer consumes less energy and workers make energy profits. The virtual energy bank keeps accounts for all devices, authenticates the trading, and settles payments through a lossless bookkeeping-like manner. We analyze the employer's expense-minimized and workers' profit-maximized decisions and prove that the optimal decisions compose a Stackelberg equilibrium. To quantify the potential in energy saving, we further apply the framework to a relay-based sensor network where a source employs relays to forward data with a minimum rate requirement. An algorithm is developed for the NP-hard expense minimization problem. The simulation results reveal that our proposed framework and mechanism improve the energy efficiency by providing a win-win situation for both sides.