Faster, Cheaper Wireless Home Nets Emerge

If you long to stream video files around your house wirelessly, but haven't wanted to pay the price for a corporate wireless network, your wait is almost over.

In the next few weeks, networking giants Netgear and D-Link both plan to launch 802.11g adapters, followed quickly by access points and routers, company officials say. The new standard has a theoretical capacity of 54 megabits per second, almost five times as much as the 11-mbps capacity of the 802.11b products that have exploded in popularity in the past 18 months.

While the systems' real-world throughput will likely be about half their rated speed, they can still carry high-definition television signals. That means you could record a show on a PC in your bedroom, then stream the signal to a TV in your living room. While connecting your TV to a home network can be tricky today, rest assured it won't be for long. That sort of "connected home" scenario is the Holy Grail that both consumer electronics and computer technology companies are chasing.

The vendors showed the equipment for the first time at the recent Consumer Electronics Show. Meanwhile, a pair of chip vendors are crafting ways to maintain video quality at the higher speeds that 802.11g supports.

Faster and Cheaper

Of course, corporate-oriented 802.11a products have for months offered the same 54-mbps capacity as 802.11g. But the "g" products have a few advantages. For one, they'll be cheaper than comparable 802.11a products. D-Link's 802.11g PC card adapter sells for $80, and its 802.11a version, $140. Its 802.11g router is priced at $150; the 802.11a version, $290.

And "g" products operate on the same 2.4-GHz radio frequency as 802.11b products, meaning devices using the two technologies can work together. Finally, 802.11g products have a greater range than 802.11a devices.

One cautionary note for early adopters: The earliest 802.11g products will appear before the standard is completely set. Officials at Netgear and D-Link say they don't anticipate problems. Any significant changes can be fixed with a software upgrade, they say.

The head of the Wi-Fi Alliance, the industry trade group that oversees the networking standard, is more guarded.

"We think there is a risk of pre-standard products causing confusion," says Dennis Eaton. Motorola officials say they are waiting until the standard is set before releasing its 802.11g products.

Smoothing Video

Even when the 802.11g standard is final, no one claims it will guarantee perfect video transmission. The network's capacity can decline with interference or many streams of information traveling at once. Video signal can be interrupted if the network gives priority to another stream of data. Those kinds of problems can cause the stutters and blocky images often seen in streamed video.

Two smaller companies say they have solutions to that problem.

ViXS Systems, a Canadian chip manufacturer, tackles the issue by monitoring the video stream. A viewer wants a consistent 30 frames of video per second, company representatives say. The ViXS chip constantly monitors the fluctuations in the network capacity, altering the video signal to maintain transmission of at least 30 frames per second.

If the network capacity declines, the ViXS chip lowers the quality of the video signal--the picture is less sharp, but it doesn't stutter or go blank. Once the network throughput improves, the ViXS chip sends a higher quality of video.

A demonstration of the company's technology was impressive. While the shifts in video quality were noticeable on close observation, they were much less distracting than the delays and hiccups that usually plague streamed video.

ViXS is selling its chips to manufacturers of PCs, networking products, and other devices. Products containing the chips should be on store shelves in the last quarter, company officials said.

Alternate Method

Another chip maker, Magis Networks, takes a different approach to the video problem.

Instead of changing the video signal to suit the network as ViXS does, Magis' Air5 chips aim to ensure no other data streams interfere with the bandwidth needed to stream video at its highest quality.

The company uses the 802.11a template, but employs different software that assigns as many as eight levels of priority to data signals, with video always at the top of the list. It's as if the video signal is a kind of digital movie star who's always able to cut to the head of the line for a popular restaurant or show.

The result is consistently crisp and sharp high-definition video streaming, according to Pete Fowler, Magis Networks executive vice president.

Air5 chips are already being used in a Samsung plasma display and an LCD TV by Sanyo, Fowler says.