News Archive: December 2007
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News Archive: December 2007 |
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12/23/07 - HD Interference: Not Just For AM Anymore [link to this story] Radio World Engineering Extra dropped a bomb this month with a very provocative cover story: "What Are We Doing to Ourselves, Exactly?" Written by Doug Vernier, the man who authored the technical specifications for an ongoing Corporation for Public Broadcasting-sponsored HD Radio interference analysis, the report is the first of its kind to document interference between FM-HD stations around the country. Using anecdotal reportage, some sophisticated contour-mapping, and presumably "early data" from the CPB study, Vernier's article conclusively proves how stations running in hybrid HD/analog mode can (and do) interfere somewhat significantly with not only themselves, but their neighbors on the FM dial. Most interesting tidbits: 1. First-generation FM-HD transmitters cannot produce a signal that can fit the National Radio Systems Committee's most recently proposed digital radio spectral emissions mask (in plain English: stations that run first-gen HD analog/digital signals cannot conclusively avoid causing interference to their neighbors). 2. Adjacent channel interference, which Vernier dubs "grunge," can be severe: one FM station caused "significant second-adjacent interference to a distant station owned by the same company at a reception point within 3 to 4 miles of the (HD) transmitter....In another similar case, a station's grunge placed excessive energy on the first - and second-adjacent channels, which wiped out the receive signal of several translators transmitting from the same location. The fix was an expensive output bandpass filter for the offending transmitter." 3. There is discernible interference between an FM-HD host station's analog signal and digital sidebands: "After turning on [HD transmissions], many stations have reported that their analog air monitors exhibit white noise in the background." 4. "Perhaps the most serious threat to the hosting station is when dual antennas are used....For example, as reported [in an earlier issue of RWEE]...a station located in a populated area of Minneapolis turned on its [FM HD signal] using a separate antenna and was surprised to find the HD operation caused severe interference to the hosting analog station within a 2 mile area...station engineers quickly turned off [the HD signal], took down the antenna and installed a a high-level [analog/digital signal combination] system, which eliminated the interference." Vernier's conclusion is pretty stark: "What we have done with the introduction of [FM-HD] is to superimpose a new transmission method over an existing allocation system, hoping it will work. In many cases it does; but there are more cases coming to light every day where there are problems....There are still those who say, 'Don't look a gift horse in the mouth'; the FCC gave us the use of this new spectrum, so let's make the best of it. Being neighborly to the stations and their listeners adjacent to your FM channel seems to have taken the back seat over a more hedonistic view of 'Let's push on and make amends for what we have done later.'" This is a significant piece of work. Firstly, it utterly destroys the fallacy that the HD Radio transmission protocol uses "no new spectrum" - the mantra the FCC and industry both used to ignore the problem of interference-by-design that is HD Radio. But perhaps more importantly, it suggests that, like we have seen with AM-HD adoption and proliferation, interference problems may grow on the FM dial as more stations begin hybrid analog/digital broadcasts. The real
extent of the problem may only be quantified over time and, like listeners
to AM stations have discovered, we'll suffer as it plays itself out.
We may have a better glimpse at just how bad the interference potential
is before the year is through, as the CPB's study is supposed to be
in final-draft stage. Most if not all of Vernier's article is based
on 12/20/07 - Microradio: As Pawn and Pain In the Ass [link to this story] It's hard to imagine that the FCC in 2007 would end the year with such a thud, but it has. With the promulgation of a rule effectively repealing the ban on newspaper/broadcast station cross-ownership - drafted in the dead of night, formally introduced in a newspaper op-ed, modified without consensus, and approved along partisan lines, with outright disdain for the 99.99% margin of public disapproval of both the practice and policy - Kevin Martin's FCC has firmly put itself in the political cross-hairs. A lawsuit to challenge the ruling is in the works, and members of Congress are yelping as their constituents call all pissed off (and rightly so); they're pondering taking actions ranging from a "resolution of disapproval" of the FCC's cross-ownership action, to a bill formally repealing the FCC's decision, to a campaign to scrutinize and overhaul the FCC itself next year. The latter option would definitely be the most interesting to observe - anytime an agency goes into the legislative woodshed for restructuring, it's going to disrupt business as usual. Regardless, this issue is far from finished, and still has the potential to undertake several dangerous iterations. In the midst of the media ownership hullabaloo, presumably as a move to mollify some of its critics, the FCC released another Report and Order and Notice of Proposed rulemaking regarding the LPFM radio service. This is the agency's first bona-fide effort to both protect and truly expand LPFM to a majority of the country. Not only has the FCC formally committed to opening another LPFM station application window (date TBA), but it acknowledged the need to take the technical straightjacket off the service and prioritize its existence more fairly relative to other FM stations, especially translators. Not only did the FCC explicitly conflate the LPFM issue with the proliferation of translator stations, but it in effect came down on the side of LPFM - a somewhat radical turn in policy, if effectuated. The Prometheus
Radio Project has written
Predictably, the National Association of Broadcasters announced its opposition to an LPFM expansion, stressing its aged refrain that trying to "shoe-horn" "hundreds, if not thousands, of additional LPFM stations...into an overcrowded radio dial without causing considerable interference simply defies the laws of physics." This, of course, flies in the face of the NAB's ongoing attempt to do just that, by giving AM radio stations beleaguered by digital interference mass-access to FM translators. Meanwhile, unlicensed microbroadcasting continues, relatively unencumbered by FCC nonsense. You wouldn't think so by a first glance at the numbers, though: at its current pace, the FCC's Enforcement Bureau will be able to claim that it carried out - on average - one enforcement action per day against a pirate station in 2007. A great example of how to lie with statistics.
However, this is not to deny that there is much more FCC action taking place against pirate stations now than ever before. You are free to manually count the number of parties affected by the FCC this year, but I'd guess that it would come out somewhere north of 100. By and large, though, this activity remains purely administrative - visits and warning letters. These have multiplied fairly dramatically, and the time between initial contact by FCC field agents and the issuance of a follow-up station warning letter has been cut to a month or less. In some especially active areas of the country, the escalation of cases to threats of actual penalty takes place now over the course of months, not years. Even still, the number of stations fiscally penalized (or threatened with such penalties) in 2007 constitutes less than 10% of the total enforcement activity, and you can count the nunber of station raids on one hand. Two interesting trends come out of this year's FCC enforcement activity. The first is that the nation's "pirate radio capital" seems to have shifted, enforcement-wise, from southern Florida to the New York metropolitan area, with a lively satellite scene in New Jersey. Secondly, a significant number of today's microbroadcasters are operating to serve ethnically identifiable audiences, audiences so far off mainstream radio's radar screen as to be effectively invisible. Some of these stations operate as commercial ventures. Several have been fined, and most (if not all) have been able to plead their cases down to nominal amounts. You can bet, in these cases, as one person "gets dinged" the gear simply moves along to a new home. In sum, as always, it pays to be cautious and well-informed, but by and large the radio cops are still paper tigers; opportunity is still tied to risk, and that's ultimately a call the microbroadcaster must make. The fact that there are so many of them out there, however, speaks for itself - keep in mind we only document the ones who get caught. |
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