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BUSINESSWEEK ONLINE
SCIENCE & TECHNOLOGY
Wireless Takes to the High Wire
The race is on to
perfect new ways of blasting data
If radio signals
were visible to the human eye, cities might look like this
view of Los Angeles: up to their gargoyles in radio waves.
You would see transmissions from millions of cell phones and
laptops, Palms and pagers, bouncing, bumping and reflecting
through the urban canyons.
What you might notice, right away, is that radio spectrum is
limited and getting more crowded every day. Communication
businesses already feel the crunch. If they want to provide
a new cell-phone service or wireless Internet access, they
either have to license more frequency from the government or
get smarter about how they use the airwaves.
Fortunately, radio engineers are getting incredibly smart.
In a stunning set of breakthroughs, scientists at Lucent
Technologies Inc.'s (LU)
Bell Labs are figuring out how to stack antennas in arrays
that could yield a hundredfold increase in radio capacity.
If it works, that will mean huge boosts in wireless voice
and data traffic, with no extra spectrum costs. Cisco
Systems Inc. (CSCO)
is playing the same game, charging into the high-speed
wireless arena with flashy signal-processing techniques
acquired from Stanford University.
''HOTBED.'' The U.S. government is lending a hand,
funneling money for wireless research to universities--where
profs are busily filing patents and spinning off wireless
businesses. Venture capitalists, sniffing quick returns, are
beefing up equity stakes in undercapitalized wireless
startups. ''This whole area is a hotbed of activity,'' says
James J. Hannan, a technology vice-president at Sprint Corp.
(FON)
''The opportunity is now.''
Bell Labs incited much of the current frenzy back in
September, 1998, when its researchers unveiled a technology
called Bell Labs Layered Space-Time (BLAST). The name evokes
Star Trek wizardry--and that may turn out to be justified.
In the normal world of radio, the amount of information you
can transmit in a slice of spectrum is limited by
interference from radio signals bouncing and echoing in the
same space--a phenomenon known as multipath. The more
channels you cram into that space, the uglier multipath
effects become.
With BLAST, engineers can turn this problem into an
advantage. Instead of restricting the number of
transmissions at a single frequency, engineers deliberately
stack up transmitters and receivers. That means more
multipath effects. But incredibly, it also means better,
clearer signals for everyone using the technology.
BLAST works by breaking up the message to be
transmitted--whether it's a cell-phone call or a compressed
music file--and parceling the pieces among two or more
antennas clustered close together. The transmission is then
beamed to a similar array of receiving antennas. Along the
way, the signals bounce around, scatter, and get scrambled.
But that doesn't faze the smart signal-processing chips on
the receiving side. Here, antennas pluck bits out of the
brew, compare them with what neighboring antennas have
collected, and then piece the original transmissions back
together. ''With 20 antennas, you have the same power and
bandwidth [as with one], but you can get 20 times
the normal capacity,'' says Gerard Foschini, the Bell Labs
researcher who developed the basic principles. ''BLAST is
revolutionary,'' says Joseph M. Kahn, a professor of
electrical engineering at the University of California at
Berkeley. ''When you talk about how to increase capacity,
this is the most promising approach.''
BUNDLES. This technology is well-suited to local area
networks in offices and homes, where it could replace the
tangle of cables that snake behind desks and under floors.
Lucent will also test BLAST outdoors, in fixed-wireless
environments. But the biggest market could be in mobile
communications. Lucent managed to get aspects of BLAST
technology incorporated into U.S. standards for
next-generation mobile phones. The company also hopes to
bundle BLAST with cell phone equipment it ships to overseas
service providers.
Competitors and skeptics in academic circles question
whether BLAST is really suited to the world of mobile
phones. Tiny cell phones aren't likely to brandish more than
one or two antennas, at the most. And in a fast-moving
vehicle, Bell's fancy chips will have to work overtime to
extract and interpret the signal data. ''This will require a
tremendous amount of signal processing,'' says Babak
Daneshrad, a professor of electrical engineering at the
University of California at Los Angeles, who has a Defense
Dept. grant to develop circuit techniques to address this
bottleneck.
Lucent must also contend with other players that are rushing
products to market. Just one week after Lucent unveiled
BLAST, Cisco announced plans to trade $157 million in stock
for a tiny spin-off from Stanford University called Clarity
Wireless Inc., which was on the brink of commercializing
high-speed wireless data technology that bears a close
affinity with BLAST. Cisco has since rolled out a line of
fixed-wireless products, offering business customers
Internet access at a blistering 50 megabits per second--far
faster than most cable modems.
A second Stanford spin-off with space-time technology,
called Gigabit Wireless Inc., has also entered the
fixed-wireless fray, founded by Arogyaswami Paulraj, a
prominent Stanford electrical engineering professor. Paulraj
hopes to have high-speed products on the market early next
year. His technology is now being evaluated by Sprint, among
others.
In the short term, disputes over intellectual-property
rights could dampen some of this excitement. Researchers at
Stanford, Lucent, and AT&T (T)
all claim paternity for key pieces of the space-time
processing used in BLAST. Lucent has patented many of the
specifics. But Paulraj and Stanford claim patents on the
basic idea of multiple antennas transmitting to multiple
receivers. Cisco also has patents through Clarity. And
AT&T holds the rights to some space-time techniques used
to code signals for mobile phones.
RADICAL. If history is any guide, staggering sums of
money will change hands as these disputes shake out and
broadband wireless emerges from infancy. If you doubt it,
consider the fresh fortunes amassed in fiber-optic
communications. Breakthroughs at university engineering labs
and at Bell Labs over the last decade led to radical new
techniques for amplifying optical signals and splitting
pulses of light to squeeze more capacity out of glass
fibers. Then, as now, patent applications flooded into
Washington, professors fled universities for optical
startups, venture capitalists placed frantic bets, and
market values for teensy companies with names such as
Optical Networks, Qtera, E-Tek Dynamics (ETEK),
and JDS Uniphase (JDSU)
rocketed into the multibillions.
Wireless promises a repeat performance. But it's too early
to say which companies will attract all the new wealth. When
it comes to marketing wireless broadband technology, Cisco
probably has a leg up. But for all its Internet routing
expertise, it has little experience managing wireless
complexity. ''The wireless world is a hall of mirrors--full
of unexpected events,'' says Richard Howard, Bell Labs'
director of wireless research.
Even these uncertainties, however, have a strangely familiar
feel. ''We may be right where fiber communications were
three or four years ago,'' muses Sprint's James Hannan.
Ladies and gentlemen, place your bets.
By Neil Gross in New York
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