Microsoft has developed a new kind of Wi-Fi network that performs at
its top speed even in the face of interference. It takes advantage of a
new Wi-Fi standard that uses more of the electromagnetic spectrum, but
also hops between the narrow bands of unused spectrum within television
In 2008, the U.S. Federal Communications Commission approved limited use of "white spaces"—portions
of spectrum adjacent to existing television transmissions. The ruling,
in effect, expanded the available spectrum. Microsoft developed the new
network partly as a way to push Congress to allow much broader use of
white spaces, despite some concerns over interference with some other
types of wireless devices, such as wireless microphones.
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.