Speed limit on WiFi about to get a boost
A new version of the popular WiFi wireless data network system performs up to five times faster than current gear, and the computer industry expects it to spawn a new era of networked home entertainment.
The new ''WiFi-N" devices, which went on sale earlier this month, will enable consumers to play their favorite tunes or watch their favorite movies over their home wireless networks. The devices are far faster than most Internet users will ever need.
WiFi-N's technical name is 802.11n. It's the latest in a series of wireless standards issued by the Institute for Electrical and Electronics Engineers and used by electronics makers worldwide.
Today's standard WiFi versions, WiFi-A, -B, and -G, have become standard issue in millions of laptop computers, allowing users to gain high-speed Internet access in airports, hotels, and fast-food restaurants. WiFi is also used in millions of homes to let several family members simultaneously share a single Internet connection.
Vivek Pathela, vice president of product marketing at the WiFi networking company Netgear Inc., said that TV makers have been experimenting with WiFi-N for over a year. ''They're very keen on realizing wireless transmission," said Pathela, because it would allow a single digital video recorder to serve TVs throughout a house.
A few adventurous consumers use WiFi-G devices to beam digital entertainment from their computers to standard TV sets or stereos. WiFi-G's data transmission speed of 54 million bits per second is fine for relaying music downloads to a stereo set. But TV shows or movies contain far more data, and the transmissions are more susceptible to radio interference.
But even with data-rich high-definition television signals coming soon, consumers may wait before embracing WiFi-N devices. The new technical standard isn't expected to be officially ratified by the engineering institute until next year. And most WiFi users have little to gain from the extra speed delivered by WiFi-N, since the current WiFi generation is already much faster than the broadband Internet connections in American homes.
Users will only benefit in a big way when they can connect TV sets and stereo gear to a WiFi-N network. ''That's what these vendors are banking on in the long term, that within a year a lot of complementary applications will come along," said Jean Kaplan, a WiFi research analyst at IDC Corp. in Framingham.
Sony and Hewlett-Packard Co. have already tested the market with external ''bridge" devices that receive WiFi-G signals and pipe them into stereos or TVs. Also, a China-based start-up called ED Digital has plans to sell flat-panel TVs with WiFi-G built in. The sets are designed to show high-definition videos created in Microsoft Corp's Windows Media Video compression format.
All this comes as the Hollywood studios have begun selling movie downloads over the Internet, and major TV networks rebroadcast their shows online. The makers of WiFi-N products say most people will want to view their videos on a big TV set, rather than on a computer monitor, and their faster WiFi technology will make it happen.
WiFi-N boasts speeds as high as 270 million bits per second. Pathela acknowledged real-world speeds will be much lower -- maybe just half the maximum. But that's still enough to support high-definition wireless TV. And ''there's still room for improvement," Pathela said. In theory, he said, WiFi-N could perform up to 600 million bits per second.
WiFi-N routers are so fast partly because they're actually several routers in one. They use a radio technique called MIMO, for ''multiple input, multiple output." Each router contains two or more separate radio chips to send and receive data over two or more antennas. The outgoing data is divided into several separate streams, but all these streams are transmitted at the same time. A MIMO-compatible receiver picks up all the incoming streams and reassembles them. This sharply cuts the time needed to send a given amount of data.
MIMO broadcasting isn't just faster; the signals also travel farther and are less susceptible to interference. With today's wireless devices, people who live in large houses often get slow data speeds as the signal is weakened by distance and intervening walls. Netgear competitor D-Link Inc. says its new WiFi-N systems will solve this problem for many consumers.
''I'm seeing double the speed at the same range," said D-Link spokesman Michael Scott, who said he's gotten good signal from 120 feet away, even with three walls in the way.
Hiawatha Bray can be reached at bray@globe.com. 
