ABSTRACT
Communication networks are familiar to all of us: e-mail, the Web, video over cable, and thousands of smartphone applications are essential components of our lives. Less familiar, yet no less important, are hidden data networks. Computing has grown to be pervasive in modern infrastructure. Although most infrastructure computing is confined to microprocessors with limited functions (heating systems in buildings, fuel monitors in vehicles, traffic control systems, devices that track packages, alarm systems, etc.) these functions gain considerable value to the extent that they are networked, even if such networking is hidden from casual observation.
