ABSTRACT
The digital infrastructure – the interconnected web of sensors, actuators, wired and wireless communication networks, and computer systems that support civil and environmental systems – is growing to be as complex and multi-faceted as the physical infrastructure it is meant to serve. Ensuring the quality and reliability of the digital infrastructure is increasingly a mission critical task for agencies such as utilities and departments of transportation. Operating agencies cannot ignore or postpone indefinitely deployment of the digital infrastructure. There are immediate imperatives to monitor and detect terrorist actions such as chemical and bioweapon attacks. Similarly, population growth drives increased demand on the physical infrastructure for example, in the form of increased capacity utilization. Changing expectations and quality of life also place demand on infrastructure. Coupled with a decrease in investment, there is a need for new methods to make do with current facilities. The digital infrastructure promises to monitor the condition of our physical infrastructure, providing the information to make more effective use of our current resources while meeting user needs. Power generation and distribution may be better balanced across the power grid via real-time load monitoring, avoiding potential failures and price spikes from peak loads (Rabaey et al. 2001). Intelligent transportation systems promise to help reroute traffic to smooth and speed flows on congested city streets (McQueen and McQueen 1999).
