The road to alternative high-speed data transport services via broadband-over-power-line [BPL] technologies once appeared wide open.

But now that path is being obscured by the blue and red flashing lights of emergency responders who — along with other mobile radio users — may cause the Federal Communications Commission to derail the nascent technology.

Emergency service organizations and amateur radio operators have raised serious questions concerning the near-ubiquitous transport system capable of delivering data over power lines, due to fears that the system might cause leakage that would interfere with crucial radio frequencies.

Consequently, the FCC has opened a Notice of Inquiry [NOI] to determine whether BPL is the tool that would bring high-speed data to the masses or a radiation-leaking threat that would negatively impact certain mobile radio communications.

The technology's problem, according to those who oppose it, is that it unnaturally modifies power lines to transport high-speed data, and in doing so, radiates energy that interferes with communications in more than 80,000 public and amateur radio assignments.

“Until we're absolutely, totally certain that it's not going to interfere with our public-safety operations, we just can't support it at all,” said David Buchanan, chairman of the spectrum committee for the Association of Public Safety Communications Officials [APCO] and a network services supervisor for San Bernardino County, Calif.

National Telecommunications & Information Administration [NTIA] officials are conducting a two-part study — the first phase of which is expected to be submitted to the FCC this winter — that will measure 10 million BPL signal samples to define the radiation emanating from the power lines and its potential for local interference.

The study will recommend to the FCC radiated emission limits, compliance measurement procedures and other authorization conditions. The report's second phase will include statistics on long-distance interference from large-scale, mature deployments of BPL systems, taking into account both underground and indoor wiring, according to a spokesman for NTIA, which co-manages government spectrum use.

In a speech to the Power Line Communications Association [PLCA] in Washington, D.C., last December, Acting NTIA Assistant Secretary Michael Gallagher explained that his organization is not completely opposed to BPL.

“The central technical issue from NTIA's viewpoint is the risk that BPL systems might interfere with federal government radio communications or other private users that are important from a national perspective,” Gallagher said, citing FCC Part 15 rules that deal with frequency radiation. BPL runs in spectrum from 1700 kHz to 80 MHz, where it could touch frequencies assigned to a plethora of federal government entities, including national emergency response, law enforcement, search and rescue, and aeronautical and maritime operations.

However, BPL's most strident critics are amateur radio operators, who vow to stop the technology from being deployed.

“There is a significant problem here,” said David Sumner, CEO of the Amateur Radio Relay League [ARRL]. “If you put RF energy, which is what a broadband signal is, on an unbalanced, unshielded piece of wire … there's no way to prevent it from radiating because you're feeding it into what constitutes an antenna. It's simply a matter of physics.”

While Sumner bristles at the suggestion that the FCC might favor a new broadband transport system over hobbyist radio users, he concedes that ARRL would have “a tougher fight on our hands” if its members constituted the only affected user group.

“The same frequency ranges that affect us affect short-range broadcasting [and] affect aeronautical, maritime, military, the FEMA system,” he said. “We're all in this together.”

Buchanan agreed that the amateurs “support public safety … particularly in HF [high frequency] communications. If it [BPL] ruins that, that's no good for public safety either.”

Still, he'd like to see more results before closing the door on BPL.

“We don't have a problem with it — if we're absolutely certain it's not going to cause harmful interference,” Buchanan said.

That's a considerably more neutral stance than the one taken by the Federal Emergency Management Agency [FEMA], which filed damning comments to the FCC's NOI. “The purported benefits of BPL in terms of expanded services in certain communications sectors do not appear to outweigh the benefits to the overall public of HF radio capability as presently used by government, broadcasting and public-safety users,” the filing said.

However, the agency last month softened its stance. FEMA indicated it had not concluded a “material interference problem” exists and expressed hope that BPL eventually could be provided without compromising emergency communications, in a letter to FCC Chairman Michael Powell from Michael Brown, undersecretary for emergency preparedness.

FEMA initially was working from old data, said Steve Greene, director of regulatory affairs for Amperion, a leading vendor in the BPL space that is rolling out several BPL-based systems with power companies this year. Greene said Amperion has “conducted very extensive field testing … as required by the FCC” and that those tests proved the technology to be compliant with emissions standards.

“There are emissions, but the real question is if it meets with the proper rules — and that answer is clearly yes — and [it] does not cause harmful interference,” he said. “We are compliant with the Part 15 rulings which are currently in the books.”

Compliance may not be enough. The amateurs maintain Part 15 covers only momentary radiation bursts, such as noise from garage door openers, not ongoing transmission leaks. Sumner compared it to the difference between a helicopter passing overhead or hovering.

“What we're facing with BPL would be the equivalent of having a helicopter parked over your house 24 hours a day,” he said.

The very nature of the transport system — power lines — is another problem, because BPL requires unnatural modification of the symmetrical 60 Hz transmission, said William Blair, an advisor to the Electric Power Research Institute. But those problems probably aren't enough to prevent BPL rollouts in the end, conceded Blair.

“There are technical problems with shielding, with the designing of the transmitters for efficiencies and so forth,” he said. “[But] if somebody does it and they could actually implement this stuff and it's under Part 15, then I don't think the critics have much to say. I doubt the FCC is going to run around and change the law.”

It doesn't appear the FCC will change its attitude towards BPL anytime soon. Chairman Michael Powell still is bullish on the technology, judging from remarks he made in a speech to the National Press Club last month.

“With BPL, you theoretically reach every power outlet in America with a broadband connection,” he said. “Our goals of universal service will be substantially advanced if this service is deployed.”

While Commissioner Kathleen Abernathy seemed to pull back a bit when her office issued a “what-she-meant-to-say” statement last fall, more recent remarks indicate she too is enthusiastic about BPL. Her office “expressed regrets” in November that remarks the commissioner made in a September speech may have failed to make clear her concern about BPL interference issues.

“We regret that the commissioner's remarks may have been interpreted as suggesting an absence of concern over harmful interference,” Abernathy's senior legal adviser Matthew Brill said at the time, in a press release that eventually appeared on the ARRL's Web site.

However, in a speech delivered to students at Catholic University's Columbus School of Law last month, Abernathy hailed the potential of the technology to bring broadband to rural and underserved areas.

“If the engineers can find a technical solution that prevents harmful interference, BPL represents a tremendous advance for consumers, because it could bring broadband to any home that has electricity,” Abernathy said.

Despite Powell and Abernathy's apparent zeal, Sumner, believes his organization is on the right track. “There's no question in my mind we're going to win,” he said.

If so, it won't be without a fight, promised Amperion's Greene, who brings to the table considerable lobbying power in the form of the United Power Line Council and other utilities' associations eager to find new revenue streams for their embedded power line plant.

“It's in the FCC's court right now,” said Greene. “They've been very supportive of the industry so far. They've gone on record as saying this is an extremely important broadband initiative.”

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