The key to the whole idea is an old but suddenly resurgent signaling paradigm called millimeter wave technology. Millimeter waves are smaller than the radio waves that transmit cell phone and Wi-Fi signals, and since this portion of the airwaves is not as widely used as others, Facebook can use it to send much larger about of data. Others have used millimeter wave systems to send data between two distant points, like ground stations and satellites. But it’s always been a bulky, power-hungry setup. Facebook is pushing toward the kind of lightweight, energy efficient applications that have only been contemplated in scientific journals and maybe some secret government labs. “There are a lot of theoretical papers on this,” says Robert Heath, an electrical engineer at the University of Austin. “But there aren’t a lot of people who are actually making it work.” Heath says that Facebook’s millimeter wave team rivals any in the world.
