BPL inherently flawed, League CEO tells Broadband Alternatives conference

ARRL Chief Executive Officer David Sumner, K1ZZ, told a New York City conference on "Alternative Broadband Platforms" March 18 that broadband over power line (BPL) has "an inherent technical flaw" - interference potential - that cannot be completely nor inexpensively eliminated.

He also told the gathering that no BPL system operator can guarantee that its system will always work or that it will be allowed to operate. Sumner said the problem is simple: Power lines were not designed to carry broadband signals,
so they can't do it very well.

"BPL is not a radio spectrum user. It is a radio spectrum polluter," Sumner told the Columbia Institute for Tele-Information (CITI) workshop, "Alternative Broadband Platforms: Can They Compete With Fiber Optics? Where?" at Columbia University. "And if the pollution causes harmful
interference to an authorized radio station, the BPL system operator has the absolute burden of fixing it - even if that means shutting off the system."

Sumner asked his audience to keep this unique shortcoming of BPL in mind as they compare and consider the alternative broadband platforms discussed. The 70 conference participants included BPL manufacturers and proponents as well as individuals involved in some aspect of broadband telecommunications, members of the academic community and students.

Directed by Eli Noam, KE2PN, CITI held its first workshop on BPL - then called PLC - in February 2002 and has held several more since. This month's event was the first in which ARRL was invited to participate. The conference's entire morning session was devoted to BPL.

In addition to the question of interference, Sumner also raised the legal obstacles confronting BPL. "I think you can see - or hear - why we radio amateurs are concerned," he said after showing the audience a video clip of BPL interference recorded in Briarcliff Manor, New York, last December. "But anyone who is thinking about investing in BPL should also be concerned, because the interference you just heard is illegal," he continued. "It is prohibited by the international radio regulations of the International
Telecommunication Union, which the United States must observe as a treaty obligation. It is prohibited by the Communications Act. It is prohibited by the FCC's own rules."

Sumner also spoke about BPL interference complaints involving pilot projects in Iowa and Texas.

The emission limits the FCC has applied to BPL originally were established with intermittent, narrowband, point-source radiators in mind, Sumner explained. "Applying them to a high duty cycle, broadband emitter that is attached to a long conductor such as a power line is like saying that there's no difference between the noise of a helicopter that goes over your house once a day and one that hovers over your back yard all the time," Sumner said. "You wouldn't complain about the first, but you'd raise quite a fuss about the second."

Most workshop participants, Sumner said, appeared to believe that fiber optic cable close by or to the home - or a combination of fiber and coaxial cable - would be most likely to provide a broadband pipeline in 10 years. "They also liked wireless because of mobility and portability," he added.
When asked at the end of the day who would invest in BPL, "only two or three hands went up."

Sumner's prepared remarks plus additional material relating to his CITI presentation are available on the ARRL Web site.

Source: ARRL Letter - courtesy of The American Radio Relay League

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