Power Supply Issues in Battery Reliant Wireless Sensor Networks: A Review

Wireless sensor networks (WSNs) have enabled numerous embedded wireless applications in different areas, such as military/battle field, environmental monitoring, and intelligent building systems. They consist of a large number of nodes that need to operate normally for months to years to complete designated tasks. Due to the small dimension of a sensor node, the power supply attached to the sensor node has to be very limited in size. Thus energy conservation becomes a challenging issue in WSN design. Meanwhile, it is a challenge for researchers and developers to obtain long operating hours without sacrificing the system performance. A variety of mathematical models have been studied to serve as analytical tools in quantifying battery discharge characteristics. However, batteries, as the primary power supply, still fail earlier in some applications than their projected working time. To further analyze the factors that affect battery discharge, and understand the characteristics of WSN power supply, this paper surveys both physical and network communication parameters that can affect battery lifetime and cause the difference between the simulation and application results. Furthermore, it offers readers a glimpse of applying new technology-driven WSNs with energy harvesting techniques, such as photovoltaics or piezoelectric