As the cell phone market
rapidly heads towards saturation, and the existing spectrum groans and
strains to keep up with the exponentially growing traffic, a handful of
engineers are seeking out the road less traveled. Trawling for untapped
pathways that could help ease the burden of the current cell traffic
glut, a company called SIGFX has landed upon the idea of using an unused
portion of the television broadcast signal as a prime candidate to send
and receive cell phone calls.
The advantages of using
television signals for cell phone traffic are potentially enormous. For
one thing, infrastructure costs would be held to a minimum. Instead of
building new cellular towers, carriers could just piggyback onto
existing TV towers for services. Cell traffic could provide a new
revenue stream for TV station owners, who could also provide cell phone
service to under-served “dead zones” in rural areas. “If you don’t have
a lot of infrastructure costs, there’s an interesting profit margin,”
says SIGFX Chief Executive Officer Dr. Dallas Nash, an engineer who has
spearheaded research into TV phone traffic.
An
Unlikely Source
Based in Ridgeland, Mississippi – a
tiny southern city that’s no one’s idea of a fertile hi-tech incubator –
SIGFX may well be on the cusp of a technology that could inalterably
change the global telecom landscape. That’s a remarkable feat for a
company is well outside the traditional R&D loop. But what’s perhaps
even more surprising is the unlikely alliance that has sparked this
innovative new approach to telecom. Jimmy Rogers, a veteran insurance
executive in Mississippi, had been besotted with the idea of using
television signals to carry cell phone traffic since 1995, but despite
his persuasive pitch to countless engineers and potential financial
partners, he could never convince anyone to back the project without the
hard science to support his theory.
“I’d been looking halfway
around the world to find someone who would take this on, but no one
would consider this being a possibility,” says Rogers, who speaks in the
lilting cadences of a true southern gent. “Even Dallas didn’t think it
would work.”
Dallas Nash, who has spearheaded the project, is a
veteran communications consultant for countless organizations, including
the Defense Department. In 1991, Nash sold his company Dataplex, which
specialized in database management and image recognition, among other
things, to Dallas-based Affiliated Computer Systems. By the
mid-nineties, he was financially comfortable, and looking for new
challenges.
As it turned out, Rogers and Nash attended the same
church, and Rogers had been impressed with a multimedia presentation
that Nash had mounted for a new building project. On this basis alone,
Rogers in 1996 approached Nash with his concept. Rogers, in fact, had no
knowledge of Nash’s extensive hi-tech resume, only that he seemed like a
tech-minded fellow. “Jimmy kept saying, ‘this is gonna work,’ but I was
skeptical,” says Nash. “I understood the pitfalls, because of my
background.”
Think Outside of the
Basestation
Among those pitfalls is the fact that
TV signals are powerful, while cell phone signals are considerably less
so. How could a cell phone not only handle a big TV signal without
crashing, but conversely, how could a phone send a signal to the TV
receiver that could be properly separated from other signals and then
routed?
These were just two of the vexing issues confronting
the pair. Nash agreed to try and put together a prototype cell phone
that would be able to pick up television signals. Using equipment that
he owned, Nash jerry-rigged what he calls “the world’s largest cell
phone.” This “phone” consisted of a series of computers and signaling
equipment in a van.
“We has some advanced signal processing
boxes, some 400 onboard processors,” says Nash. “We also had some
special communications equipment that would allow us to manage the
signal, and all of that became our cell phone.” Nash drove the
tricked-out van 14 miles away from Channel 46, the local TV station that
agreed to participate in the experiment, to see if they could relay a
signal. Sure enough, after doing this enough times, a faint cell signal
eventually materialized. “We thought, ‘hmmm,’ then spent a year fleshing
out that ‘hmmm,’” says Nash.
There were countless kinks to be
worked out. A massive, Van-sized cell phone is one thing – trying to
pack all of that processing power into a handheld device is another.
Nash’s current phone prototype contains four small processing chips,
enabling the unit to send signals that could be received on UHF or VHF.
But a powerful battery is required for all of that processing
power
After much trial and error, Dr. Nash landed upon the idea
of using a lithium-ion battery to fuel the processors. “The power
quotient for this phone is more than a standard cell, but not
dramatically so,” says Dr. Nash. “One big advantage of the lithium-ion
battery is its moldability. We could build a battery case out if it.
Lithium-ion batteries also don’t crack or get fuzzy over
time.”
According to Dr. Nash, numerous manufacturing companies
have expressed interest in the phone. “This is something new for them,”
he says. “This phone doesn’t require them to retool their existing
plants, even though the board structure is obviously different. Besides,
the handset market needs a new niche at this point.”
Creative Calling Plan
SIGFX
has also patented something called a Return Signal Processor, which
segregates the weak phone signals from other signals and then routes the
calls. According to Dr. Nash, this processor can be built for a fraction
of the cost of building a new cell tower.
In order for the
TV-cell phone to provide a formidable challenge to traditional cell
phones, however, far more capacity will be needed. SIGFX’s initial
experiments have used the vertical blanking interval, that thin slice of
the spectrum used for services like closed captioning. The vertical
blanking interval wouldn’t be able to accommodate more than 60 calls at
a time. Far greater capacity will be needed to handle a large volume of
calls. Nash hopes that smaller regional stations that don’t operate 24
hours a day might want to provide phone service during downtime.
With this concept in mind, SIGFX has made overtures to Asian
territories like Malaysia, South Korea and China – countries that have
an excess of TV spectrum capacity but minimal cellular penetration.
“There are literally thousands of TV towers in those countries,” says
Dr. Nash. SIGFX has entered into what Dr. Nash calls a “memorandum of
understanding” with ZTE Corporation, China’s largest telecom company.
Thus far, however, TV-enabled cell phone calls are still only
possible in the Mississippi labs of SIGFX. Dr. Nash is still trying to
work out the kinks in the phone prototype, as well as the challenges of
trying to open up enough of the TV spectrum in various territories that
might want to implement it. But there is no shortage of major players
waiting for the day that Dr. Nash and his R&D team work it all out.
“There are about 76,000 TV towers out there,” says Dr. Nash. “There’s an
existing analog communications system out there. We’re just recycling
the existing spectrum.”
Marc Weingarten
is an LA-based writer whose work appears in Business 2.0, The Los
Angeles Times, Smart Business, Entertainment Weekly, The Village
Voice, Vibe and San Francisco
magazine.