The Global Information Grid (GIG) is the top-level program for netcentric warfare. A USAF document says the GIG is "a set of globally interconnected, end-to-end information capabilities, associated processes, and personnel for collecting, processing, storing, disseminating, and managing information on demand to warfighters, policy makers, and support personnel.
"It includes owned and leased communications and computing systems and services, software (including applications), data, security services, and other associated services. It also includes National Security Systems. It provides capabilities from all operating locations (bases, posts, camps, stations, facilities, mobile platforms, and deployed sites). The GIG provides interfaces to coalition, allied, and non-DoD users and systems."
The next layer down is the Transformational Communications Architecture. The TCA is the GIG's end-to-end satellite communication transport segment. TCA programs comprise the Joint Tactical Radio System (JTRS), the Transformational Communications System (TCS), Advanced Extremely High Frequency (AEHF) Satellites, and the Mobile User Objective System (MUOS).
Further down, the Defense Information System Network (DISN) is the global, end-to-end information transfer infrastructure of the DoD. It provides the wide-area and metropolitan-area network transport capability portion of the GIG.
Power to the Edge is the final piece of the picture. Intended to be the solution to stove-piping, it's probably the most critical aspect of all the military's efforts. On top of that, it addresses the way people access, share, and interpret information--the hardest to pin down conceptually.
We're told that those who need intelligence information want to know what data exists, how they can access the data, how they will know this data is what they need, and how they can tell someone what data they need. At the same time, those who produce that information want to know how they can share their data with others and how they can describe their data so others can understand it. Power to the Edge addresses all of those questions. Elusive or not, it may be the largest opportunity for commercial and academic contributors.