Performance Evaluation of Channel Models of Zigbee Sensor Networks

The ability to achieve a reliable and optimal design of a WBAN communication system relies largely on a thorough understanding of signal propagation through and around the complex human body as a medium, which differs significantly from one person to another. Hence, it is necessary to model the human body of interest in its corresponding environment to have a successful, reliable, and optimal WBAN. In this paper, we provide a path-loss model of the propagation channel medium between a transmitter antenna and a receiver antenna based on multiple experimental measurements. A number of transmit antennas (Tx) are situated on a wearable sensor nodes and spread on different major parts of the human body, while the receiver antenna (Rx) is kept on a sink node in constant proximity to the human body. The Tx and Rx devices communicate using ZigBee technology on 2.45 GHz band. Current literature addressed channel analysis at 2.45GHz around the surface of the body assuming simplified simulation setup or/and overlooking the impact of the indoor office environment. Our contribution in this paper is to investigate 2.45GHz Zigbee statistical path-loss model thoroughly based on realistic setup and using off-the-shelf devices in an indoor office environment. Channel characteristics from the experimental measurements are compared against representative semi-empirical path loss and log-normal shadowing models.