Uwb Waits in Wireless Wings

Wireless communication’s hottest new development is still a year away
from putting a commercial product on the market, but it has already
been adapted for a wired application to double cable TV capacity.

Chicago Tribune Jon Van

This development for ultrawideband radio-or UWB-as well as its reputed
ability to transmit through walls and move tons of data in microseconds
could make it the most versatile new technology to come along since
the personal computer.

Developed decades ago by military researchers intent upon improving
radar images, UWB was given a green light for commercial development
in February by the Federal Communications Commission.

UWB’s first application is likely to be equipment linking personal
entertainment systems, computers and other household gadgets
wirelessly so that, for example, a digital camera could transmit images
to a personal computer without need of a wired connection.

Another application: A single box connected to a cable television
system from the outside could supply signals to all the TVs or personal
computers within a home without wires.

While it uses a radically different type of signal, UWB isn’t really so
different from other technologies already in use, said Martin Rofheart,
chief executive of Xtreme Spectrum, a start-up based in Vienna, Va.
UWB is "Bluetooth on steroids," he said.

Bluetooth refers to a class of low-powered radio devices that provide
wireless communication for electronics equipment. An example would be
a wireless connection between a personal computer and a printer.

The difference, Rofheart said, is that UWB uses far less power than
Bluetooth devices and sends vastly more data. Rofheart is pushing for
standards to cover UWB so that it will be embraced quickly by the
industry as the best means of sending data wirelessly over short
distances.

Products to provide UWB services are expected to be ready for
Christmas 2003, but an even more intriguing application has been
suggested by executives at Pulse-Link Inc., a San Diego start-up
company.

By applying UWB wireless technology to cable TV operating systems, it
is possible to double capacity, said Bruce Watkins, Pulse-Link’s
president. Thus a system that currently offers customers 100 channels
could increase options to 200 channels.

Operators could also expand offerings of video-on-demand services,
provide some high-definition programming or otherwise increase the
array of available products, he said.

"You can think of a cable TV operation as a bucket that you put water
into and however big your bucket, that’s your capacity," said Watkins.
"What we can do is to give the cable operator a second bucket that
holds just as much water as the first one."

While UWB is fundamentally a wireless technology that uses radio
signals to work its magic, it can also be applied to a cable TV system’s
fiber and coaxial cable with salutary results, Watkins said.

UWB uses radio in a radically different way from television, cell phones,
public safety dispatchers or other traditional applications.

Existing radio transmissions split the radio waves into frequencies set
apart by the power of their signals, or amplitude. UWB transmitters emit
radio signals in tiny pulses across a broad range of the radio spectrum,
but at very low power. Binary information is carried by varying the time
between the pulses, which are sent at the rate of 10 million to 40
million per second.

To a conventional radio receiver, UWB’s timed signals look like
background noise or static signals emitted by personal computers and
other electronic devices. But UWB receivers can get large amounts of
data quickly by reusing the same radio spectrum that’s already carrying
conventional wave-based signals.

The technology was devised for use over the air, but John Santhoff,
founder and chief technology officer at Pulse-Link, got the idea for
using UWB over fiber and coaxial cable last year.

He found it works well, carrying new time-based signals over the same
lines that are already carrying traditional analog or digital signals.

"All traditional communications are in the frequency domain," said
Santhoff. "We’re in the time domain. Most existing equipment cannot
even detect our signal."

A cable TV operator can double the system’s capacity without making
major changes, Watkins said. One device that may cost about $30,000
would be installed at the system’s front end, and then another device
would be installed in the home of each subscriber who wanted to pay
for new services. These would probably cost around $100 apiece, he
said.

Pulse-Link has set up a lab demonstration of the technology for cable
industry executives. Watkins said he hopes to partner with a cable TV
operator to equip a few systems with UWB to serve as field tests. The
firm hopes to license the technology to companies like Motorola that
make cable TV set-top boxes, Watkins said.

Santhoff began working on a wired application for UWB last year when
the FCC put off a decision to approve over-the-air applications.

"We were concerned about how long the FCC might delay action, so we
needed a contingency plan," said Santhoff. "A wired application, outside
the FCC’s jurisdiction, was something I’d thought about, but put on the
back burner. When I saw how well it worked, I was sorry we didn’t do
this sooner."

The firm has applied for an array of patents to cover its wired UWB
technology and apparently is the only company to use this approach.

"It’s an intriguing concept," said Ralph Petroff, chief executive of Time
Domain Corp., a pioneering UWB firm based in Huntsville, Ala. "It shows
that UWB as a concept has many different applications. We wish them
well."

Petroff’s firm developed some of the equipment used to generate and
read UWB signals to demonstrate it to regulators and get the go-ahead
from the FCC. Time Domain is working on its next generation chip sets
aimed at commercial products.

The FCC’s initial approval order put some limits on the amount of
spectrum over which the signal could be spread. This will limit
performance, and Petroff hopes that the FCC will loosen the restrictions
as experience demonstrates that UWB can coexist peacefully with
conventional radio signals.

The FCC is under pressure from some conventional radio spectrum users
to go slow on unleashing UWB.

Some military agencies and the National Telecommunications
Information Administration, a civilian federal agency, have urged a
conservative approach.

But that pressure is being countered by some in Congress.

http://www.technologyreview.com/offthewire/3001_2982002_2.asp