Taking wireless the last mile
- By Heather Harreld
- Dec 03, 2000
States with large rural populations know that Internet access must play
a role in just about any economic development campaign. But providing access
to outlying areas is neither cheap nor easy.
A small Virginia community has successfully tested wireless technology
designed to bring broadband service the "last mile," to rural areas where
fiber-optic lines are not available or may be too costly to install.
And other municipalities are looking to this option as the possible
answer to their economic development dilemmas.
The Local Multipoint Distribution Service (LMDS) network relies on radio
frequencies to deliver wireless two-way, high-speed data, voice and video
traffic. The hub is a site at Virginia Polytechnic Institute and State University
in Blacksburg, Va., that links to several campus buildings and an apartment
LMDS is designed to distribute bandwidth to users at multiple remote
sites. Because it is wireless, LMDS is much cheaper to deploy than fiber
optics or cable, but still offers high-speed connectivity.
LMDS offers more than twice the bandwidth of AM/FM radio, VHF/UHF television
and cellular telephone combined. Most other frequency bandwidths have stringent
restrictions, such as data traveling in one direction only or only allowing
one type of traffic to be transmitted, but LMDS is a flexible pipeline offering
high transmission speeds and supporting simultaneous delivery of multiple
types of traffic in two directions.
Proving its Mettle
The system was deployed in October 1999 through a partnership between
Virginia Tech and Wavtrace Inc., which donated the equipment. So far, the
LMDS network, which supports several hundred users, has proven reliable
in numerous tests, said Tim Callahan, LMDS project manager at Virginia Tech.
The system supports applications that operate across a wired T1 or Ethernet,
with similar performance, Callahan said. The researchers tested several
real-time and non-real-time applications, including voice-over-IP videoconferencing
and traditional downloading.
"The LMDS wireless link has not had a negative impact on any application
we have tested," Callahan said. "With the proper pre- engineering, wireless
LMDS links operate reliably with little maintenance."
Several Web servers operate at remote sites, providing content across
the wireless link. Developers have also used the system for voice applications.
With LMDS, calls are nearly indistinguishable from wired voice calls, he
Because LMDS frequencies are relatively high in the spectrum, transmission
of this very small waveform is hindered or stopped by walls, trees, buildings
and even heavy rainfalls. As a result, the system needs antennas posted
at each endpoint with a clear line of sight.
However, Callahan said the network should be able to withstand a rain
rate of more than three inches per hour. Rain this heavy typically lasts
only several minutes, and the wireless link is re-established as soon as
the rain decreases, he said.
Cortney Martin, director for broadband wireless networking at Virginia
Tech, said the network transmits 30 megabits of data per second. In the
next release of the system, which is scheduled for next year, the LMDS system
will be able to transmit 180 megabits/sec, she said.
Despite these high-speed connections, one of the main draws of the technology — which is used primarily on leased buildings — is its flexibility, Martin
"Those leases may end at any time," she said. "We can take the equipment
with us and move it. We really wouldn't be able to justify fiber in most
of these cases. We can justify the wireless."
Dennis Sweeney, an assistant research professor with Virginia Tech's
Center for Wireless Telecommunications, said the success of the system has
resulted in several other Virginia communities expressing interest in the
Officials are designing a system for Halifax County, Va., to connect
businesses, a corporate training center and a continuing education center
in a planned 148-acre industrial park. In addition, Henry County, Va., has
commissioned the university to perform a feasibility study for offering
the technology to businesses and residents there, Sweeney said.
William Confroy, executive director of the industrial development authority
in Halifax County, said the technology would allow the rural county to be
more competitive in economic development.
"It would be extremely competitive and would probably be one-fourth
or one-eighth the cost of what present costs are for those businesses,"
he said. "It will put us on par with the rest of the world, and it will
give us the opportunity to recruit new business."
It's the Economy
Tim Hall, public information officer for Henry County, said the county
considers itself very competitive in most aspects of economic development,
except for its relatively rural location and its low population (56,000).
Offering LMDS to potential businesses could "move us to the head of the
line" in economic development competition with other counties and states,
"If we can offer a company the very cutting-edge technology that they
don't expect us to offer, that may sway some companies our way," Hall said.
Glenn Ratliff Jr., general manager of Internet service provider GCR
Online Inc., said a potential application of the LMDS system is for county
government agencies to use the wireless technology for backup or even for
primary high-bandwidth, high-speed connections for daily communications
"The town is looking at a wireless solution because it's too expensive
to run fiber," he said. "Something like this could be the answer to their
problem from day one. They could have some secure connections, some that
are open to the public. They could stand an outage. That's going to be a
potential money-saving scenario."
In addition, because many of the ISP's customers are small businesses
and government agencies that cannot afford full-time IT technical em-ployees,
GCR handles local-area network administration for many of its customers.
Now, GCR employees spend about 10 percent of their time visiting customer
sites for routine maintenance, such as creating new user accounts and updating
software, Ratliff said. But with an LMDS connection, all that work could
be done remotely from the company's offices.
Virginia Tech also plans to study the feasibility of extending the technology
to Grundy, Va., a coal town with a population of about 16,000 that is being
moved by the Army Corps of Engineers because of its current precarious location
on a flood plain, according to Sweeney. Meanwhile, researchers are exploring
using LMDS radio technology to devise a "wireless neighborhood," he said.
"Think of this equipment not as some hub transmitting out to some location
but as a wireless cable," Sweeney said. "It would cost us a couple hundred
dollars and it would look like a wireless Ethernet. For a very low cost,
the LMDS could literally replace the cable. You can have almost instant
The National Science Foundation has given Virginia Tech money to develop
a portable LMDS system, which would not require a clear line of sight between
the transmitter and the receiver and could be used for communications in
disaster-recovery situations, Sweeney said.
Officials at Virginia Tech are in discussions with other vendors, including
Alcatel, Ameritech Corp. and Verizon Communications for future research
project partnerships. In addition, several other universities have formed
a partnership with Virginia Tech to develop the technologies necessary for
deploying a broadband wireless system in the Appalachian region that will
focus on health care applications, manufacturing and delivery of training
and education to remote sites.
Developers are negotiating a large-scale advanced networking project
in the Washington, D.C., area that would link its various LMDS projects.
Harreld is a freelance writer based in Cary, N.C.