- 1-Structural monitoring with wireless sensor networks : Experiences from field deployments

In the last years, wireless sensor networks have emerged as a promising technology that is inducing a deep innovation in the field of structural monitoring. The main advantages of wireless sensor networks are fast deployment, little interference and selforganization. However, since wireless sensor nodes are battery powered, in long term monitoring applications the power management influences significantly the operation of a wireless sensor network. In data intensive applications, e.g. vibration based monitoring, low power hardware, duty cycle operation and efficient communication policies are not sufficient for achieving a sustainable system lifetime. Since data communication is the most energy consuming task, long system lifetimes can only be achieved by a significant data reduction in the nodes. This data reduction is a challenging task, since it has to be performed with very limited computational and memory resources and in competition with tasks providing the basic network functionality. The objective of the paper is to provide a brief overview of the wireless sensor network technology and to present our experience over the past three years with data intensive structural monitoring using wireless sensor networks. Deployments on two bridges are illustrated and specific aspects of sensing, data quality, stability, availability, and system lifetime are analyzed. 1 WIRELESS SENSOR NETWORKS