“The Federal Aviation Administration is in the midst of a multibillion-dollar upgrade of the nation’s air traffic control system. The new system is called the Next Generation Air Transportation System, or NextGen. It will be highly automated. It will rely on GPS instead of radar to locate planes, and it is designed to allow air traffic controllers and pilots to pack more planes, helicopters and eventually drones into our skies.”
Source: Could The New Air Traffic Control System Be Hacked? : All Tech Considered : NPR