The epicenter
of the next phase in the software-defined
radio revolution is likely to be De Leon, Texas, a town
of about 2400 people that is roughly 220 kilometers
southwest of Dallas. De Leon’s main attraction for the
last 92 years has been its annual Peach and Melon
Festival. The town also is the home of a rural
mobile-phone provider called Mid‑Tex Cellular, which
three years ago became Vanu’s first commercial customer.
What the Experts Say
NICK TREDENNICK: It sounds good, but hardware
cost per channel could be too high, especially
compared to FPGA alternatives that also offer
reconfiguration.
“We were looking for new technology, something that
was more flexible and maybe would allow us to avoid
constant hardware changes,” says Toney Prather,
Mid-Tex’s CEO. The company’s existing network was based
on older, TDMA (time-division multiple access)
technology, and to move to a newer standard, such as GSM
or CDMA, the provider faced hefty upgrade costs.
Standard base stations run about $50 000 apiece—which
can add up fast. AT&T Wireless reportedly spent $10
billion to give its TDMA network a GSM makeover.
In early 2003, Prather agreed to let Vanu supply
Mid-Tex with GSM software-defined base stations on a
trial basis. At the time, Vanu didn’t actually have a
working GSM base station, but its engineers got busy,
and within seven months they had software that was good
enough for a field trial [see “Mobile Phone System
Passes Texas Test,” IEEE Spectrum, February 2004].
Since then, Mid-Tex has deployed 29 Vanu base
stations, which all run on Hewlett-Packard ProLiant
servers and handle about 6 million minutes of calls each
month [see diagram, “Inside
the Anywave”]. The carrier has since
shifted most of its 11 000 customers from TDMA to GSM.
In addition, more than 20 percent of its revenues come
from the major carriers, through roaming agreements
that give their users cell coverage when they travel
through Mid-Tex’s 21 000-square-kilometer territory.
In all, Prather figures he has spent about $2 million
on his Anywave network. That’s about what he would’ve
paid for traditional GSM equipment, but now he won’t
need to buy an entirely new network when he adds CDMA.
Nor will he need to lease additional T1 lines to get the
signals from the cell site to the switch—which can run
several hundred dollars a month per line. That’s because
the base station architecture is IP-based, so the same
T1 can handle any type of call from any carrier. A
single T1 could even handle multiple sites, Prather
says.
What’s more, the company can now perform diagnostics
remotely over the Web, cutting maintenance costs.
Eventually, the new network may even save Prather’s
business. Rural cellphone providers always worry that
one of the bigger carriers will extend its network or
“overbuild” their territory. “You’re battling the
giants,” Prather says. “But if we can provide a network
efficiently and cheaply, then they won’t want to
overbuild it.”
At press time, Mid-Tex was field-testing the new dual
GSM-CDMA software at two of its sites, and Prather was
eager for Vanu to give him the go-ahead to upload the
CDMA code throughout his network. “I hope it’s any day,”
he told Spectrum. “We’re ready now.”
Anywave
deployments so far have been limited to rural
areas such as De Leon and certain military
installations. But Bose expects to land some much bigger
fish within the next year or two. Vanu executives have
recently been getting a warm reception when they’ve
demonstrated the new multistandard technology for some
of the major carriers.
What the Experts Say
T.J. RODGERS: There may be room for some
configurable radios in the expensive base-station
market. But with silicon radio chips now costing
less than 50 cents to manufacture, there has to be
limited consumer market appeal for expensive radios
with less-than-optimum performance.
Another promising area is in smaller base stations,
sometimes called “femtocells,” which are designed to
offer wireless coverage within an office building or
household. The worldwide market for femtocell products
is expected to reach nearly 19 million units by 2011,
according to ABI Research. “Our technology is a great
fit for that,” Bose says.
But wait, there’s more: Bose says his company’s
technology could just spark a restructuring of the
wireless-infrastructure industry. At present, it’s
still mostly vertically integrated, with companies like
Ericsson, Huawei, and Nokia producing nearly all the
components, from the base stations to the antennas.
Rather than having a single company do everything, Bose
suggests, the “horizontalization” of the industry would
result in more agile companies—including Vanu—doing
whatever they’re best at.
It sounds like a big leap, but that’s precisely what
happened in the computer industry 20 years ago, when
Digital Equipment Corp., IBM, and other giants gave way
to upstarts like Apple, Intel, and Microsoft.
The IEEE P1900 Group, established in 2005 by the
IEEE Communications Society and the IEEE Electromagnetic
Compatibility Society, is creating standards related to
new technologies and techniques being developed for
next-generation radio and advanced spectrum management,
including software-defined radio. See the committee’s
Web site at http://www.ieeep1900.org.
In “Hardware for Your Software Radio,” in the
October 2006 issue of IEEE Spectrum, senior associate
editor Stephen Cass reviewed a do-it-yourselfer’s kit
for designing and testing software-defined radio systems (http://spectrum.ieee.org/oct06/4654).