High-Definition Video over Wi-Fi

Wireless chips could soon manage a gigabit of data per second.

Several next-generation wireless schemes, including WiMax, 4G cellular technology, and others that explore previously untapped parts of the radio spectrum, promise faster, better connectivity through the air. But these standards still face business and technological challenges. In the midst of all this, a startup called Quantenna plans to improve wireless connectivity simply by supercharging Wi-Fi. With this goal in mind, the company, based in Sunnyvale, CA, will release chip sets in the coming months that can handle a gigabit of data per second over Wi-Fi--enough to stream high-definition video and other content over short distances.

Beam me up: Quantenna’s Wi-Fi chip, shown here, contains four antennas for sending data and four antennas for receiving. While increasing the overall bandwidth, these antennas also enable a technique called beam forming. This creates a line-of-sight wireless link between devices that can transmit a gigabit per second’s worth of data--enough for high-definition video content. Credit: Quantenna

"In my experience," says company CTO Andrea Goldsmith, who is also a professor at Stanford University, "you can't have a successful wireless company unless you're standards based."In other words, Goldsmith believes that it will be a lot easier to roll out technology that is compatible with Wi-Fi than with chips that use relatively uncharted frequencies. (See "High-Def Is in the Air.") The reason is simple economics: fewer companies may be willing to embrace an unproven technology rather than a well-established one.

Quantenna's chips use a specific Wi-Fi standard called 802.11n. (See "Faster, Farther Wi-Fi.") Among other things, 802.11n allows up to four antennas to be used to transmit data, and four to receive it. Compared with Wi-Fi chips with a 2x2 antenna scheme--the most common type on the market today--Quantenna's chips are twice as powerful, Goldsmith says. "For the same data rates and same applications, you can go twice the distance."

Story continues below

But it is the specific way in which Quantenna's multiple antennas work that set them apart from existing Wi-Fi technology: the antennas form a direct wireless link between enabled devices, using a technique called beam forming. Unlike traditional radios that send and receive data in all directions, a beam-forming radio locates a receiver and concentrates the signal into narrow paths for each data stream. When this sort of wireless link is formed, data can be transmitted at much faster rates. It could wirelessly connect components of home theaters, streaming high-definition content between, for example, a DVD player and a television. Currently, beam-forming technology is used in wireless chips that operate at between 60 and 100 gigahertz--far beyond the 5- and 2.5-gigahertz frequencies used by Wi-Fi.