Energy in Wireless Sensor Networks

Abstract

Wireless sensor networks (WSNs) are composed of cooperating sensor nodes that can perceive the environment to monitor physical phenomena and events of interest. WSNs are envisioned to be applied in different applications, including, among others, habitat, environmental and industrial monitoring, which have great potential benefits for the society as a whole. Each sensor node typically includes a sensing component responsible for data acquisition from the physical environment. The node also has a processing unit for local data processing and storage, a wireless communication interface for data communication between nodes, and a power source to supply the energy used by the node to perform the programmed task. The power source often consists of a battery with a limited energy capacity. In many applications, sensor nodes may not be easily accessible because of the locations where they are deployed or the large scale of such networks. In both cases, network maintenance for energy replenishment becomes impractical. Furthermore, in case a sensor battery needs to be frequently replaced the main advantages of a wireless sensor network are lost, i.e., its operational cost, freedom from wiring constraints, and possibly more important, many sensing applications may become impractical.