The fastest Wi-Fi networks, which can transmit data at up to a gigabit per second, use as much spectrum as possible, up to 160 megahertz, to maximize bandwidth. Krishna Chintalapudi and his team at Microsoft Research have pioneered an approach, called WiFi-NC, which makes efficient use of these white spaces at these speeds.
Rather than using a conventional Wi-Fi radio, it uses an array of tiny, low-data rate transmitters and receivers. Each of these broadcast and receive via a different, narrow range of spectrum. Bundled together, they work just like a regular Wi-Fi radio, but can switch between white-space frequencies far more efficiently.
That means the system is compatible with existing equipment. "The entire reception and transmission logic could be reused from existing Wi-Fi implementations," says Chintalapudi.