Energy harvesting noise pollution sensing WSN mote: Survey of capabilities and limitations

Wireless sensor networks (WSNs) are potentially a boon to the implementation and enforcement of noise codes which now exist for many major cities all over the world. Unfortunately, the high energy required by the noise measurement process and the reliance of sensor motes on batteries make the management of noise sensing WSNs cumbersome. Giving motes energy harvesting (EH) capabilities could alleviate such a problem, and several EH WSNs have already been demonstrated. Nevertheless, the high frequency nature of the data required to measure noise places significant additional challenges to the design of EH WSNs. In this paper, we characterize the capabilities and limitations of a WSN mote designed to measure noise. We identify, through specification analysis and experimentation, the performance-limiting factors in each step of the noise measurement process. These steps include sound gathering, data processing, and result transmission. The prospect of the entire process being powered by energy-harvesting means is also evaluated. For each step, we also discuss and recommend measures that would help improve the overall system performance.