Ultrawideband: Still a Player?

The notion that ultra-wideband (UWB), the sometimes controversial unlicensed
wireless technology approved for commercial use by the FCC in 2002, could be
a competitor for Wi-Fi gained credence last October when Pulse-LINK demonstrated a prototype UWB-based
wireless LAN.

The Pulse-LINK technology is interesting, to be sure, and will get even more
interesting, but the company’s president and chief operating officer Bruce Watkins
hastens to reassure Wi-Fi vendors and others with a vested interest in 802.11.

"I’m not somebody who says that just because we’re doing ultra-wideband,
we’re going to take over the world of Wi-Fi," Watkins says. "I don’t
begin to believe that for an instant."

"There are economies of scale in place with Wi-Fi, it’s a mature technology.
And it’s just going to keep getting cheaper. Ultra-wideband will not be there
from a price standpoint."

Watkins sees his company’s products capturing maybe one to two percent of the
current Wi-Fi market by the end of 2007, but it will never be a competitor across
all of Wi-Fi’s application markets.

"Is there a short-term threat [to Wi-Fi from UWB]? I don’t think so. Is
there a long-term threat? I wouldn’t use the term threat," Watkins says.

The interesting thing about the Pulse-LINK WLAN demo was that despite a widely
held view that UWB is only suitable for very-high-data-rate Personal
Area Networks (PANs) with a range of no more than 10 meters, Pulse-LINK showed
a prototype with a range of 20 meters and a data rate of 125 Mbps.

"The notion that there is something in the rules of physics or in the
FCC regulations that means ultra-wideband can only go 10 meters is just wrong,"
says Watkins.

That was the point of the October demo — to serve notice that what Pulse-LINK
had been telling its investors and strategic partners was for real. It could
extend the range of UWB and still remain compliant with FCC regulations.

"Rather than try and argue the point in white papers, we decided to just
build something and prove it," Watkins says.

The first-generation prototype only operated in point-to-point mode, though,
and the range — about 65 feet — is not enough for a practical LAN. Pulse-LINK
expects to have a second prototype in the spring, however, that will operate
point to multipoint at up to 100 meters, and support up to 250 client devices
— that’s mobile devices — with a data rate of 7 to 8 Mbps.

If you were about to say, ‘Yes, but Wi-Fi is faster,’ think again. The Pulse-LINK
technology will deliver 7 to 8 Mbps at 100 meters. At that distance in 802.11a
and 802.11g networks, data rates fall off to lower values.

"Data rate and range is an advantage," Watkins says, "but
it’s not the advantage."

He points to three other crucial factors that will give UWB — or, rather,
Pulse-LINK’s proprietary implementation of UWB — a leg up over Wi-Fi in very
specific application markets: improved security, more precise positioning and
non-interference with other networks.

The most important is security. Watkins says the first applications of Pulse-LINK’s
WLAN technology — it could be a commercial product as early as the first half
of 2005 — will be in homeland security and other areas that require high security,
such as airports.

Pulse-LINK claims there are seven ways in which UWB offers better security
than Wi-Fi, even before applying encryption — and because UWB offers higher
data rates, it can more easily afford the high overheads of encryption.

It would be nearly impossible for would-be evesdroppers to intercept data on
a UWB network. This is because of the way UWB radios operate — by sending very
short, randomly-spaced pulses over a broad range of spectrums. A UWB network
is only sending pulses four percent of the time.

"The engineering challenge to even find our signal is monumental,"
Watkins says.

Because Pulse-LINK is pursuing a proprietary approach, even if an interceptor
could find the signal, it would still need to know about proprietary
channel definitions and modulation techniques before it could capture signal.

The Pulse-LINK technology, unlike some other CDMA-like implementations of UWB,
requires the receiver to capture every pulse sent out by the transmitter. So
even if an interceptor could hone in on a signal and capture it, missing just
one sub-nano-second pulse would mean lost — and therefore unreliable — data.

Advantage three? "With UWB, we have highly accurate information on where
client devices are located in the coverage area," Watkins says. "That
has security implications and also makes possible some neat functionality."

Finally, early concerns from the cellular industry about UWB systems interfering
with their networks have now been conclusively disproved, Watkins claims. Like
others in the UWB space, he says established wireless players hyped the interference
issue for mainly competitive reasons.

Pulse-LINK has shown that even when the antenna from a UWB system is touching
the antenna of another system, the UWB system doesn’t interfere. In fact, it’s
much more likely that other RF systems will interfere with UWB.

"Imagine if you wanted to use wireless technology in a security setting
in an airport," Watkins says. "You’ve already got Wi-Fi there in the
Admiral lounge. You’ve got people walking around with Bluetooth headsets. You’ve
got tenants using freespace optics, LMDS — there’s a plethora of spectrum already
in use. If you want to introduce something else, it’s got to be something
that doesn’t interfere."

That’s UWB, he says.

At the same time Pulse-LINK is developing the second prototype, it’s also working
on ASICs (Application Specific Integrated Circuits) — a chipset — for its
UWB radio. That work should be complete by the end of 2004, Watkins says.

Pulse-LINK ultimately does not want to become a product company. It would rather
be a technology licensing company on the model of Qualcomm
in the cellular industry. However, it will work with strategic partner Unisys to develop access point and
client device products based on the chipset.

The products will sell into markets that Watkins says Wi-Fi can’t satisfy —
though secure Wi-Fi equipment vendors such as Harris
Corp.
and Fortress Technologies
might disagree. While Pulse-LINK would certainly sell its products into an enterprise
market, he admits they will not compete well with standard Wi-Fi products.

"We’re going to be more expensive than Wi-Fi solutions," he says.
"Folks looking for something that Wi-Fi can serve will not be satisifed
with our price points."

Watkins explains that although much has been made of the reduced engineering
complexity of UWB, his company’s technology, because it pushes the envelope,
will not enjoy the economic benefits of that reduced complexity. "When
you start doing the things we need to do to get the higher range, it gets kind
of expensive," he says.

Wireless is Pulse-LINK’s main focus at the moment, but the company is also
working on technology for wired media, currently CATV (cable TV) wiring but
possibly home electrical and telephone wiring in the future. Watkins claims
the technology may be capable of hitting USB2 data rates — 480 Mbps.

The wired technology may turn out to be a more serious threat to Wi-Fi, at
least in the home market, than Pulse-LINK’s wireless LAN products. Imagine a
converged multimedia/consumer electronics device that could be automatically
added to a wideband network just by plugging it in to a wall socket!

Pulse-LINK expects to have so-called "wired UWB" product no later
than the end of 2005. The company hopes eventually to produce a single chipset
that would enable both wired and wireless UWB networking products operating
at different data rates and ranges.

Watkins is accustomed to fielding questions about which wireless technology
is going to "win in the end" — UWB, Wi-Fi, Bluetooth, something else
again. He says those questions won’t be relevant for long. Emerging software-defined
radio technology will create a grand convergence, making possible economical
radios capable of transmitting and receiving using all three technologies —
and possibly others undreamed.

"We’re working on it, others are working on it — consortiums have been
formed to work on it," Watkins notes.

He’s also accustomed to nay-sayers, including from within the UWB world, who
doubt his company can do what it says it can. They also doubted that UWB could
work at all, he poins out, or that it would ever be approved by the FCC, or
that the cellular powers that be would let it move ahead without a legal challenge.
All of those things happened.

"It’s not my job to convince them," Watkins says. "We’re happy
to have them believe [we can’t do what we say we can] for as long as possible.
It’s only incumbent on us to bring the technology to market to prove it."

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