An ultra-wideband wireless body area network: evaluation in static and dynamic channel conditions

Wireless body area network is a collection of wearable wireless sensors placed around or in a human body that are used to monitor important information from a human body. A receiver (i.e. control unit) is required to connect these sensors to remote locations (i.e. hospital database and call centres). In this work an ultra-wideband (UWB) body sensor node has been designed and tested to analyze the realistic performance of a UWB-based wireless body area network. The results indicate that the locations of sensors and the control unit on a human body play an important role on the performance of the wireless body area network system. The work herein also investigates optimal receiver positions for different sensor configurations. The results are evaluated in both static and dynamic channel conditions based on data transmission from the UWB sensor node developed for wireless body area network applications. Four common sensor positions, namely the chest, head, wrist and waist and three receiver positions-chest, waist and arm are considered. The experiment is conducted in an Anechoic chamber to minimize the effects of the environment. In the static experiment, the subject under test remains motionless for the entire test duration. Under static channel conditions, it was seen that the transmission power can be reduced by 26 dB, when the receiver is positioned at the optimum point on the body. The evaluation of the dynamic channel condition is also performed by allowing the test subject to move the body as in a walking motion. Due to the body movements, the transmission power should be increased by 7 dB to maintain the same bit error rate as that of the static experiment