Interference study finds room for more low-power FMs
Battling over low-power FM could resume with the release of a study that suggests permitting microstations closer to their full-power neighbors.
The study, conducted by the nonprofit tech research firm MITRE Corp. and released last month, recommends that the FCC license LPFM stations on third-adjacent channels to full-power stations--a prospect that once drew strong criticism from NPR and others in public radio.
Following that suggestion could engender many more of the tiny, low-wattage noncommercial stations. That would give more wannabe broadcasters access to the airwaves but also permit interference that could eat away at the fringes of public radio signals.
The FCC now keeps LPFMs certain land distances from full-power stations if they use third-adjacent frequencies--that is, frequencies within 0.6 megahertz. Following that rule reduces the number of potential LPFMs by 80 percent, according to the FCC.
The rule could be relaxed, the MITRE study says, "provided that relatively modest distance separations are maintained between any LPFM station and receivers tuned to the potentially affected LPFM station."
MITRE did not recommend waiving distance separations entirely. Instead, it devised a formula for determining spacing. Resulting distances could range from a kilometer to a "few tens of meters."
The FCC created the new class of stations in 2000 under Democratic Chairman Bill Kennard, who wanted to diversify media control. Based on its own research, the commission dropped the third-adjacent protections. Congress overruled the FCC in 2001, ordering it to uphold the protections. Low-power advocates complained that the reversal squeezed low-power signals out of larger markets. Congress ordered the agency to commission an independent interference study, hence the MITRE report.
As of late May, 113 LPFMs were licensed to broadcast, and more than 500 others have received construction permits preliminary to licensing, according to the National Federation of Community Broadcasters. Almost half of LPFM permits and licenses have gone to religious groups.
The FCC has almost finished processing uncontested applications and is preparing to settle mutually exclusive filings, says Cheryl Leanza, deputy director of the pro-LPFM Media Access Project.
Low-power stations are limited to using small, 100-watt--or even 10-watt--transmitters. (The FCC has not yet accepted applications for 10-watt stations.)
The introduction of the service prompted cheers from grassroots broadcasters but upset NPR and commercial broadcasters, who feared that the stations would interfere with their signals and radio reading services for the visually impaired. It remains to be seen how the MITRE study will reshape the debate.
The report discounts or plays down a number of interference worries:
- LPFM signals did not interfere with a radio reading service receiver as long as the transmitter and receiver were at least 80 meters apart.
- Stations transmitting digitally experienced no more interference from LPFMs than analog broadcasters.
- Interference "was not strongly correlated with variations in terrain or program material type." NPR had argued that quieter public radio fare such as news and classical music could be especially vulnerable to interference.
Tradeoff: regional or local?
Most stakeholders in the interference debate have yet to digest the complex, 308-page report. Some have handed it off to engineers for analysis. Reactions so far sound like echoes from the past, with established broadcasters advising caution and LPFM advocates upbeat and hopeful.
"The tests pretty much bore us out," says Pete Tridish of the Prometheus Radio Project, a Philadelphia group that lobbies for micropower broadcasting and has argued against third-adjacent protections for LPFMs.
But Prometheus and MITRE risk playing down the need for continued spacing of LPFMs, says Scott Hanley, g.m. of WDUQ in Pittsburgh and an NPR Board member. If the spacing formula is ignored, he says, LPFMs could knock out the service of full-power stations like his to "city blocks' worth" of urban listeners.
NPR declined comment on the study, but David Noble, chair of government affairs for the International Association of Audio Information Services, said he would still support third-adjacent protections based on his quick scan of the study.
One observer, however, has changed his mind since the advent of LPFM. Broadcast engineering consultant Doug Vernier, a now-retired Iowa pubradio manager, supported third-adjacent protections in 1999. Since then, experience with translators on second- and third-adjacent frequencies to full-power stations has proven to him that LPFM's current protections may be needlessly strict.
"There's, frankly, enough spectrum out there that third-adjacents aren't going to cause a significant problem to public radio at this point," he says. "I wouldn't have said that several years ago, but I think that we have seen enough proof that radios are good enough today that it isn't a huge issue. The MITRE study is more proof of the pudding."
NPR and commercial broadcasters have argued that third-adjacent signals would interfere with reception within their FCC-protected geographic contours, Vernier says, but their greater fear is that LPFMs will obscure their signals in the lawless areas beyond the contours. They would lose distant listeners if more LPFMs are licensed and would have no recourse at the FCC.
"It's a tradeoff between what low-power can give a local area as to what a regional public radio station can give a regional area," he says.
In Vernier's view, looser rules won't hurt public radio, considering its growing audiences. "And I think there is a need for low-power, community-based stations," he says. "The question is, is there a need in one community for 20 of them?"--a scenario he says could occur without third-adjacent protections.
The FCC has asked for reply comments on the MITRE study by Sept. 12. The agency would have to win congressional approval to remove third-adjacent protections, raising the chance that the low-power debate could quickly become political again. Sen. John McCain (R-Ariz.), who championed LPFM in 2000, has already expressed interest in revisiting the issue, according to Radio World.
Web page posted Aug. 7, 2003
Copyright 2003 by Current Publishing Committee