Manassas Powers Up

The city's electrical grid links subscribers' computers to fiber-optic network via broadband over power lines.

by / May 7, 2004
Plug and play has a whole new meaning in Manassas, Va.

Residents in search of high-speed Internet connections need look no further than the nearest electrical outlet. In what is said to be the first citywide service of its kind in the United States, Manassas is using its power grid to deliver broadband data service to local businesses and homes. As of early February, about 70 people were enrolled in the broadband over power lines (BPL) service.

"We have 600 or 700 more on a waiting list," said Allen Todd, director of Manassas Utilities, a city agency.

Officials at Manassas Utilities weren't thinking about Internet service when they started exploring technologies for carrying data over power lines -- they just wanted a reliable way to identify power outages in their distribution network.

Manassas Utilities was using technology to monitor its water plant, electrical substations and other major facilities, but systems to do the same for transformers on the power grid were expensive, Todd said.

Then the American Public Power Association (APPA) introduced city officials to, which develops, markets and sells complete power-line communications (PLC) systems to power utilities. This gave utilities the chance to use their existing power line grids as a commercial communication medium.

Ron Lunt, APPA's director of broadband services, said a visit with the company convinced him the technology was viable.

"We talked to Manassas to see if they'd be interested in deploying it and applying for a grant through our DEED [Demonstration of Energy-Efficient Developments] program, our R&D group," Lunt said, adding that APPA approached Manassas because the city was already looking for this sort of technology, and is close to's office and APPA's headquarters in Washington, D.C.

The technology looked good on paper, Todd said, so Manassas tried a pilot system that covered a small section of the city.

" provided the equipment, APPA provided the funds and we did the installation," he said.

Launched in May 2001, the system not only transmitted data from distribution circuits, but also provided Internet service to about 10 residential and commercial customers.

Surprisingly Good
"To our surprise, it worked very well," said Todd, admitting his initial skepticism. "The reliability was good. We didn't have a unit fail. It was operating at a very good rate of speed and looked like it also gave us the monitoring we needed for the transformer outages."

Manassas added customer Internet connections because revenues from offering broadband service would give the city power-monitoring capabilities for free, he said.

The service also helped the city make better use of its fiber-optic ring, which it installed in the 1990s to replace leased phone lines. Since the fiber connects the city's traffic signal control system to all traffic lights, it offers extensive coverage.

"We own and operate our own power system," Todd said. "We own and operate our own fiber network. We were looking for a way to merge those two together, and this was one way to do it."

Power lines provide a convenient way to carry data between the backbone and subscribers' premises -- it gets expensive to run fiber into each house, and the city would have to dig up sidewalks, gutters, streets and back yards to run that fiber.

Since the power infrastructure already reaches into every building, the city could avoid those disruptions. Manassas also wouldn't have to shut off electrical service to start the data flowing, he said, and city workers already have the necessary skills to install and maintain the equipment.

Repeaters Boost Signal
Carrying broadband data on power lines is not simple because, unlike telephone or cable TV infrastructure, the power grid wasn't designed for communications, said Joseph Marsilii, president and CEO of

A device called a concentration unit injects a radio frequency (RF) signal into the power grid and converts Ethernet data from the city's fiber-optic network into a format that can ride the RF signal. The system also works with other backbone technologies, such as T1 lines or wireless broadband.

As the RF signal travels down the electrical lines, it loses energy. To counter this loss, repeaters were installed at each transformer. To ensure signals reach their destinations, they are re-energized upon reaching the repeaters, which transmit an alarm to the utility if the transformer loses power, Marsilii said.

To send and receive data, the customer connects a power line modem -- about the size of a small paperback book -- to a computer, and plugs it into an electrical socket. The current powers the modem and delivers the RF signal, which the modem converts back into Ethernet.

If the modem is connected to a portable computer, the subscriber can go anywhere in the city, plug the computer into a wall socket and get on the Internet, Marsilii said.

Once the pilot proved the concept, Manassas installed equipment for a full deployment. In October 2003, Manassas awarded the service franchise to New York-based Prospect Street Broadband. Manassas Utilities installs and maintains equipment on the network, and Prospect Street installs modems for customers and handles billing, customer service, technical support, the backhaul to the Internet and Internet content.

"They're the provider," Todd said. "We're just providing access to our customers through the utility grid."

Residential customers pay $26.95 per month. Business customer rates range from $59.95 per month for service at 256 kb/s to $359.70 per month for 1,500 kb/s. At the residential level, the system is slightly slower than cable or DSL, but the average user doesn't notice the difference, Todd said.

Revenue Stream
Besides monitoring its distribution network at no net cost, the system gives Manassas Utilities an income stream. At the outset, the city gets 10 percent of Prospect Street's revenues. Its share will increase with penetration.

"The more successful they are, the more money we make," Todd said.

Because city-owned buildings already operate on the fiber network, Manassas isn't connecting power line modems to its own computers. As the city adds new traffic signals, however, it might use the power grid to connect them to its traffic control system, rather than running fiber to each intersection, Todd said.

Manassas Utilities is the first public power company to launch a BPL service, but will likely have company soon. Rochester Public Utilities in Minnesota has announced it will begin exploring the technology with Hiawatha Broadband Communications of Winona, Minn. is working with several investor-owned utilities, including Georgia Power, Alabama Power and PPL Electric Utilities in Pennsylvania. It's also talking with about a dozen municipal utilities about conducting market trials, Marsilii said.

Competitors in the private sector have not complained about the city utility's new role in delivering Internet service, Todd said, noting that the city has good relationships with local telephone and cable companies, and the city is part of a growing region.

"Right now, there are enough customers and enough business for everybody," he said.
Merrill Douglas Contributing Writer
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