BPL would use low and medium-voltage lines like these in a typical residential area to distribute digital data using HF and low-VHF frequencies.
BPL would use low and medium-voltage lines like these in a typical residential area to distribute digital data using HF and low-VHF frequencies. |
NEWINGTON, CT, Aug 6, 2003--ARRL President Jim Haynie, W5JBP, says Broadband over Power Line (BPL)--if widely deployed--would represent "spectrum pollution" on a level that is "difficult to imagine." Haynie reacted after seeing videotape and early data from recent ARRL field studies in four states where BPL is undergoing testing.
"BPL is the most crucial issue facing Amateur Radio and the one that has the most devastating potential," Haynie said. In terms of interference potential on HF and low-VHF frequencies, "nothing is on the same scale as BPL."
A form of power line carrier (PLC) technology, BPL would use existing low and medium-voltage power lines to deliver broadband services to homes and businesses. Because it uses frequencies between 2 and 80 MHz, BPL could affect HF and low-VHF amateur allocations wherever it's deployed. BPL proponents--primarily electric power utilities--already are testing BPL systems in several markets, and one reportedly is already offering the service. FCC rules already allow BPL, although industry proponents want the FCC to relax radiation limits. It's feared such a change could exacerbate BPL's interference potential.
At the West Gulf Division Convention (Austin Summerfest 2003) August 1-2 in Austin, Texas, Haynie previewed a short video (see below) that covers highlights of a recent field tour by ARRL Lab Manager Ed Hare, W1RFI. The video, which will complement technical data ARRL is gathering and compiling, turned out to be a real eye-opener for many in the audience.
Walt Dubose, K5YFW--assistant chairman of the
ARRL High Speed Multimedia (HSMM) Working Group--said it was about what he'd
expected. "But for most attending--maybe 60 percent--it was much worse than
they had imagined, and for some it was a real shocker," he reported. Dubose
said a few of those viewing the video simply couldn't believe that BPL actually
was causing the high noise level.
 ARRL Lab Manager Ed Hare, W1RFI, in his "BPL-mobile," specially equipped to monitor the HF spectrum for BPL interference. Hare recently returned from visiting several communities where BPL trials are under way. |
In late July, Hare traveled some 1350 miles to visit BPL trial communities in Maryland, Virginia, Pennsylvania and New York to take measurements over significant parts of the HF spectrum. He also took initial readings at low-VHF frequencies. Driving a specially equipped vehicle loaded with radio gear and measurement devices, Hare said he didn't need to look long or track down "a few hot spots" to find BPL interference. "The signals were all over," he said.
"The interference found ranged from moderate
to extremely strong," Hare said. The video shows the S meter of an HF
transceiver holding steady in excess of S9 as the speaker emits a crackling
din, which one observer described as sounding like a Geiger counter. Only the
very strongest amateur signals broke through on 20 and 15 meters. Hare noted
that the field strengths of the various systems all were within FCC Part 15
limits for power line carrier (PLC) devices.
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VIEW the BPL video (MPEG-1 file) that covers highlights of a recent field tour by ARRL Lab Manager Ed Hare, W1RFI:
To save the video on your computer, right-click on one of the above links and choose "Save As..." or Save Target As..." (or similar) and specify a location to save the MPEG-1 file. |
At a couple of points, the video shows noise continuing nearly unabated on 15 and 20 meters as the car moves down long streets lined with overhead wiring. Hare said the signal propagated for at least a couple of miles down one road.
"Signals would have been much stronger using
a gain antenna," he observed. Hare's vehicle carried a roof-mounted,
horizontally polarized Buddi-Pole antenna--a loaded dipole.
 Hare used a typical HF transceiver--in this case a Kenwood TS-440--to actually monitor BPL signals on the HF spectrum. His vehicle also was equipped with other receiving gear to take field strength measurements. |
Each BPL system exhibited a unique sound depending upon the modulation scheme it used, and Hare said he was able to distinguish three types during his recent tour. While in most cases, the signal sounded like static or pulse noise, in one city, it resembled sort of interference a computer monitor or similar device might generate, with warbling "birdies" blanketing the bands at closely spaced intervals. "Naturally, overhead wiring was the worst," Hare said. BPL signals continued to be audible in neighborhoods with underground electrical utility wiring, although it was somewhat attenuated.
The ARRL already has filed a 120-page package of text and technical exhibits in response to the FCC's Notice of Inquiry in late May. The League plans to file reply comments--responses to comments already filed--by the recently extended August 20 FCC deadline.
Haynie has been doing a bit of traveling of his own, including 15 days in Washington so far this year to deal with the FCC and with members of Congress on BPL and other Amateur Radio-related issues. "Unfortunately, it all costs money, and a lot of these kinds of League activities are not highly visible to our members or to the amateur community," he said.
 ARRL President Jim Haynie, W5JBP, outlined the BPL issue for a standing-room-only crowd at the ARRL Forum during the ARRL West Gulf Division Convention at Austin Summerfest 2003 August 1-2. [Walt Dubose, K5YFW, Photo] |
During his most recent stop in the nation's capital, Haynie--accompanied by ARRL General Counsel Chris Imlay, W3KD--visited the office of Rep Billy Tauzin (R-LA), who chairs the House Energy and Commerce Committee, and met with Howard Waltzman, Tauzin's chief telecommunication counsel on the committee. He also met with a staffer in the office of Rep Rick Boucher (D-VA), a member of the Telecommunication Subcommittee and a strong supporter of Amateur Radio.
Haynie says a lot of hams want to know more about BPL but are put off by the size and depth of the technical documents and filings. He feels that seeing the video presentation might make a stronger impression. Countering critics who suggest that the League is only using BPL as a fund-raising ploy, Haynie said the League would not be putting as much effort into attempting to quantify the BPL threat and to put a face on it if it weren't real.
"The BPL industry and their associations have told the FCC and the world that there is no interference potential from BPL systems," Haynie said. He noted that the American Public Power Association, in its comments to the FCC, put the burden on the technology's challengers to empirically demonstrate its interference potential.
"The video presentation does just that," Haynie said. "Anyone seeing these BPL signals for megahertz after megahertz for miles along a power line should be convinced that BPL--even operating at the present FCC limits--poses a serious threat to all HF and low-VHF communications."
While the deadline for initial comments on the FCC's May 23 NOI has passed, the FCC has now extended the reply comment deadline to August 20. More information is available on the ARRL Web site. The ARRL filed a 120-page package of comments and technical exhibits in response to the BPL NOI on July 7. There's additional information and additional video clips on the ARRL "Power Line Communications (PLC) and Amateur Radio" page.
The ARRL has initiated an important Spectrum Defense Fund campaign to support activities to educate government officials on the potential threat that BPL poses to Amateur Radio. To find out more, or to support ARRL's efforts in this area, visit the ARRL's secure BPL Web site.
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