New technology to transmit video without wires through home

Someday soon, you will be able to take the video stream that your set-top cable box brings into your living room and beam it to the television set in the back bedroom without hooking up any cables.
You will be able to transfer the video footage from your last vacation from the camcorder to the TV without fumbling with wires. You will be able to send a multimedia presentation from a laptop to an overhead projector without plugging in any cords.
These are some of the promises of ultra-wideband, a powerful technology that can transmit streaming video and other bandwidth-hogging content around homes and offices. Although ultra-wideband -- or UWB -- has been around for about 12 years, the
wireless networking industry only last month received the crucial go-ahead from the Federal Communications Commission to develop the technology for mainstream commercial applications.
Now ultra-wideband is poised to potentially shake up the world of wireless networking -- going head to head with more established wireless technologies like 802.11 and Bluetooth -- as UWB-enabled TV sets, VCRs and other devices.
``Ultra-wideband will allow you to make your surround-sound system and your video system completely wireless,'' said Michael Gallagher,deputy director of the National Telecommunications and Information Administration, a bureau of the Commerce Department that manages the federal wireless spectrum along with the FCC. ``This lets you get rid of the rat's nest of wires.''

First developed by the military, ultra-wideband works by sending veryshort, narrow pulses of electromagnetic energy across a broad swath of the radio spectrum. The military already uses the technology in ground-penetrating radar systems to detect land mines and other objects buried underground, and police officers use it in imaging systems to monitor movement behind doors and walls.
But while ultra-wideband technology is quite compelling, it is also controversial. That's because UWB signals can cross parts of the radio spectrum already licensed for other uses, including the PCS spectrum used by cellular providers like Sprint and the GPS spectrum used by the military for global positioning.

Ultra-wideband is also less expensive than 802.11, which is critical in the price-sensitive world of consumer electronics, said Chris Fisher, vice president of marketing at XtremeSpectrum, a Virginia company developing UWB chip sets that would go into consumer electronics like VCRs and TVs.
According to Fisher, the bill of materials -- the cost to the consumer electronics manufacturer to place UWB technology inside a device -- is $20 for ultra-wideband, compared with $40 for 802.11b and $65 for 802.11a.
In addition, UWB technology consumes much less power than 802.11, making it ideal for use in battery-powered devices like cameras and cell phones. Wi-Fi, in contrast, ``is limited to PCs and things that you can plug into a wall,'' said Geoffrey Anderson, vice president of Sony's advanced wireless technology group.
Perhaps the biggest drawback of UWB is its range of operation, although the technology can transmit signals farther when sending at lower data rates. Ultra-wideband can transmit signals within a range of about 10 meters, or 35 feet. That's roughly comparable to the range of Bluetooth but smaller than the range of both 802.11a at 15 meters and 802.11b at 50 meters.
Still, the range of an ultra-wideband network can be extended by placing ``repeaters'' -- other UWB-enabled devices -- around a home or office.

Liberally taken from Dewayne Hendricks dewayne@warpspeed.com