The WSN's today are used in almost all areas from health care, home intelligence application, environmental monitoring, military tracking and positioning to localization and logistics and so on. It is critical to emphasize that the application has a significant impact on the wireless technology to be employed. After the application requirements have been established, the designer must choose the technology that will allow these needs to be met. Sensor nodes are comprised of analog to digital converters (ADC) along with multifunctional sensors. The ADC is assigned the task of converting the analog or continuous data and signals into digital signals before passing them on to the processing unit. A microprocessor is used in the processing unit to execute operations on digital data such as aggregation and encryption. Radio transceivers are used in the communication module to send and receive data via a short-range radio channel. A sensor node's power module provides electricity to all of the components.