It seems amazing that our televisions are still so dependent on cables. Wireless gear reaches everywhere, with cellphones delivering chats to rural corners, PCs surfing the Internet at coffeeshops, and satellites pumping cable TV to mountaintop cabins. But still we can’t transmit a movie throughout a small home.
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There are glimmers of hope, including a new wireless television from Sharp—one of several coming soon from TV makers. Also, companies that make PC networking gear, including Linksys and D-Link, have released "media adapters" that wirelessly hurl video to a television in another room.
But all these early entrants are hobbled by Wi-Fi gear that was designed for computer data, not video. And the difference between a word-processing file and video is dramatic. High-quality video, for one, contains more data than can be transmitted by the widely popular version of Wi-Fi called 802.11b. Newer versions of Wi-Fi’s alphabet soup—including 802.11a and 802.11g—can transmit more data but still suffer from a basic design that fails video. That is, PC data is sent in "packets." Losing a few packets is no big deal for a spreadsheet; the lost packets are just sent again, meaning a slower download. With video, the result is a stutter. We’ve seen and heard it on the Internet, where streaming video and audio often stumbles. You’ll also see it on the new Sharp TV when it gets beyond its range, which is about 50 feet or less if there are walls between the TV and its base unit. The picture stalls. You suddenly miss a Yao Ming slam-dunk or a Frasier punchline.
It would be worse if Sharp hadn’t added software that smooths the hiccups. But that software makes the Sharp gear incompatible with other Wi-Fi devices. That won’t work in the long run, because nobody wants to have to buy all their video equipment from one maker. An independent group of engineers working with the tech industry has drafted plans for a new Wi-Fi variant called 802.11e, which tries to accomplish the same thing.
Still, some argue that Wi-Fi can’t be altered enough to make it safe for video and is consequently developing alternatives. An option called Ultra-wideband looks promising because it can carry huge amounts of data. But it has its own limits, particularly with short ranges. And several companies trying to build competitors to the Wi-Fi juggernaut have gone bankrupt. So it appears the PC folks have won the fight to control home networking. We’ll just hope they make it work for video—soon.
