On-body and off-body transmit power control in IEEE 802.15.6 scheduled access networks

摘要

Wireless Body Area Networks (WBANs) have received much attention due to the possibility to be used inudhealthcare applications. For these applications, energy saving is a critical issue, as in many cases, batteries cannot be easily replaced. A transmit power control scheme, able to adapt tothe variations of the wireless body channel, will allow consistentudenergy saving and longer battery life.udIn this paper we propose a transmit power control scheme suitable for IEEE 802.15.6 narrowband scheduled access networks,in which the transmission power is modulated frame by frameudaccording to a run-time estimation of the channel propagation conditions. A simple and effective line search algorithm is proposed to estimate the channel quality based on the signal power received from the hub; in addition, an adaptive fade marginudestimator is presented to determine an optimum margin based on the channel conditions. The approach allows tracking the highly variable propagation conditions due to the body mobility and the deployment of the sensors close to the human body. Anudexperimental study in different test cases proves the effectivenessudof the scheme in comparison with alternative solutions in theudliterature.