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FCC OKs Increase in HD Radio Power. Increased Interference Ahead?

On Friday the FCC’s Media Bureau quietly announced that it adopted an order to allow FM stations broadcasting a digital HD signal to increase their power levels up a maximum of 10% of the power of their main analog signal. While the National Association of Broadcasting and iBiquity have been agitating for this change for quite some time, it’s the backing of National Public Radio and its engineering report on the matter that was the likely tipping point.

But, as radio researcher John Anderson points out, this change is also likely to produce more interference complaints from listeners trying to tune in weaker stations adjacent to these higher power digital signals. There have already been significant complaints and concerns about digital HD signals interfering with adjacent analog stations with the previous power limit set at 1% of a station’s analog power.

The Prometheus Radio Project, in particular, questioned NPR’s support for the increase based on NPR’s own engineering data (PDF). Prometheus noted that listeners asked by NPR Labs to rate HD interference to analog signals at the new power levels gave the quality of the resulting audio a score of 2.7 on a 5 point scale, which is below a rating on “fair” on that scale. Prometheus further argued that,

The NPR Labs Study represents a “best case scenario” test of interference to analog. … Although the NPR Labs Study showed troubling levels of interference, the decision to use a single, highly selective receiver dramatically limited the extent to which these results can be extrapolated.

For its part, NPR responded to Prometheus and other critics [PDF], contending that they “generally misapprehend or ignore the [HD] testing methodology, the test results, or the results of NPR Labs’ prior [HD] testing.”

In its order [PDF] the Media Bureau clearly sides with NPR and iBiquity, writing

Based on our analysis of these documents and data, as well as five years of interference-free FM hybrid digital operations by approximately 1500 stations, we are convinced that an immediate voluntary 6 dB increase in FM Digital ERP is appropriate for all FM stations except super-powered FM stations.

Clearly the Media Bureau fails to acknowledge any existing interference problem, nevermind a new threat. Beyond the Commission’s tendency to blow with the prevailing industry winds–especially when the biggest commercial and public radio interests line up together–this blindness may also be explained by the fact that the FCC takes interference complaints from broadcasters far more seriously than those coming from the public. Furthermore, radio engineer Charles Keiler offers up a plausible explanation [PDF] for why the FCC might not be getting a significant number of interference complaints from the public:

Complaints from the public have not accurately reflect the interference that the IBOC signal has caused to first adjacent, to the host companion analog signal, or other broadcast services that the public relies upon. Since the digital components of IBOC sound like noise to a conventional listener, the listener tends to have a problem
distinguishing between IBOC interference and more conventional interference. IBiquity’s own subjective studies have shown that the “noise like” interference can be difficult for a listener to discern as interference.

The FCC’s answer to the interference question comes in a promise to “establish interference remediation procedures” in which the Media Bureau will “resolve each bona fide dispute or impose power reductions within 90 days.” What the Bureau prefers is that stations work out interference complaints cooperatively between themselves, notifying the Commission when an agreement that involves reducing HD power is reached.

If stations can’t resolve an interference complaint, then the analog station experiencing the interference may file a complaint. The station’s complaint “must contain at least six reports of ongoing (rather than transitory) objectionable interference” along with “a map showing the location of the reported
interference and a detailed description of the nature and extent of the interference being experienced at
that location.” Finally, the complaining station must submit a “a complete description of the tests and equipment used to identify the alleged interference.”

Quite obviously, the Media Bureau considers it the onus of the complaining station to show interference and sets a pretty high bar for demonstrating it to the Commission. Listener complaints alone will not qualify as bona fide. Any station experiencing interference will have to make a very hard economic analysis to determine if the expensive testing required will be worth it to resolve interference in particular areas. In effect, this high bar will serve to only bolster the appearance that HD radio does not cause interference because it will be too costly to demonstrate it according to the Media Bureau’s satisfaction, not because listeners aren’t actually experiencing degraded analog radio reception.

Finally, it should be noted that neither low-power FM stations nor translator (repeater) stations will qualify for any sort of interference resolution, since both are considered secondary services by the FCC. Just ingore the irony of the NAB advocating for power increases up to thousands of watts for a potentially interfering sideband signal at the same time that it has lobbied hard against LPFM stations at 10 or 100 watts, arguing that these signals will cause interference to full-power kilowatt stations. In this case, I think the ruling principle is “might makes right.”

At this point it will be up to non-HD stations and affected listeners to band together if they have any hope of seeing digital power increases limited or eliminated. However, this seems pretty unlikely to occur, especially amongst listeners. Given the sorry state of most commercial radio to begin with, listeners are more likely just to abandon radio when their favorite stations becomes degraded from HD interference. This move to improve the reception of HD radio signals might just end up chasing away more casual listeners who just associate poor audio quality (not just poor programming quality) with commercial radio.

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0 Responses to FCC OKs Increase in HD Radio Power. Increased Interference Ahead?

  1. Greg February 1, 2010 at 9:41 pm #

    Great analysis, and thank you for exposing this charade for what it is – I hope that listeners will just abandon radio, and bring IBOC to its knees.

  2. paul vincent zecchino February 2, 2010 at 5:21 am #

    Yes, there will be more interference. But the good news is, there’ll be less listeners to hear it, having moved to greener pastures of iPods, the Net, and other media.

    Why believe anything ‘NPR Laboratories’ may say? Aren’t they a beard for PBS, who’ll say and do anything to consolidate power and control over its slice of the RF spectrum by means of this HD Radio digital jammer?

    What a sick, sad, waste of resources. HD serves the interests of a few to the detriment of many.

    In a way, it’s perfectly suited for our emerging impoverished police-state kleptocracy, isn’t it?

    Of course, none of us will hear it.

    Paul Vincent Zecchino
    Manasota Key, Florida
    02 February, 2010

  3. Hans Jaektor February 3, 2010 at 7:49 am #

    from an rf jamming perspective, i simpathize with the concerns of your article and offer this as a solution: make these HD stations be required to develop sub-carrier bands for rf dispursement that carry the small broadcasters who are not using HD. yes, it will cost these big broadcast companies money to foot the expenses, but in the long run, everyone may share the HD medium. what do you think? could it happen?

  4. Brian February 4, 2010 at 8:44 am #

    Adding HD radio to new receivers has become only a few dollars per unit, so the die hard radio listeners that want to hear noise free, stereo reception can inexpensively do so. The reception after the power increase will be solid and be heard clearly and in stereo over a much larger area compared to clear analog FM stereo reception.
    It’s amazing people have grown to “accept” analog FM stereo with all its impairments as acceptable. I guess people have lived with it for so long that they have accepted it. However, now that people typically have many other noise free (up to 22 kHz) audio options to select from, noise prone analog FM is slowly becoming last on the list for audio choices. Noise free digital HD Radio is the only option that has a chance of reversing this trend, but it will take a while. Look how long it took for FM to catch on (invented in 1936 by Edwin Armstrong) but didn’t pass AM listenership until the 1980s.
    I believe after the power increase, word of mouth about the fabolous range, clear reception and increased niche programming will slowly but surely reinvigorate the FM band. I feel the naysayers are looking only at the short term picture (slight increase in interference when listening to distant first adjacent stations) and not think about the long term picture (those same FM stations not being around anymore due to the younger demographic abondoning noisy analog FM in droves due its disadvantages compared to other audio mediums.) HD radio at least addresses the audio issues, not sure if it address the content issues, but as I said it does open the possibility for more niche programming formats due to the multicast channels.

  5. Eric May 30, 2010 at 1:52 pm #

    The HD Radio increase has really hurt my ability to hear WOLG (95.9 FM), a Catholic radio station in Carlinville, IL, on my car radio. It’s blocked by interference from WFUN-FM (95.5) in Bethalto (owned by Radio One) and KIHT (96.3 FM) in St. Louis (owned by Emmis).

    “HD Radio” will never catch on. Nobody is buying the receivers. And the signal range is inferior to analog FM and AM radio. Most stations’ HD signals cannot get out beyond 30 miles, while an analog FM signal can get out up to 100 miles, and an analog AM, depending on dial position and power, can get out up to 450 miles. People are abandoning radio not because of the illegitimate claims “HD Radio” proponents are making, but rather, the lack of quality programming. FM analog is SUPERIOR to digital in coverage and sound quality. “HD Radio” is NOT CD-quality on FM, and DOES NOT deliver FM-quality sound on AM. From what I’m hearing, “HD Radio” quality on AM is worse than analog AM.

    “HD Radio” is A WASTE OF VALUABLE SPECTRUM SPACE…it wastes up to 1 MHz of valuable FM spectrum space and up to 100 kHz of valuable AM spectrum space. The FCC should get rid of “HD Radio”, and move all digital audio broadcasting to frequencies above 1000 MHz.

  6. Fluke June 11, 2010 at 9:37 am #

    The 2 previous comments directly conflict with each other.

    Without a doubt, the quality of PROGRAMMING has led to the exodus of radio listeners. HD will not fix this historical failure.

    However, the biggest single factor in loss of listenership is the plethora of alternative music/entertainment sources. period. This will only increase with time.

    HD interference is a marginal problem. If HD has any hope of success the output levels MUST increase, so that range equals analog. Frankly, the FCC would best serve the public by forcing the replacement of analog all together, just like TV. Problem solved! Then, they could jack range up big time… enabling HD to compete as much as possible in a market that is doomed to decline through a seemingly endless source of alternative music sources. I am listening to internet radio as we speak. The PROGRAMMING/CONTENT is FAR SUPERIOR to anything on “radio”!

    Digital radio can’t and WON’T make up for this complete failure on the part of broadcasters!
    (No matter how powerful the signal is! They blame everyone/thing except THEMSELVES. Idiots.You’re getting what you deserve. It’s ALL your fault. Deal with it and do something positive for once instead of whining!)

  7. Mark Robinson December 12, 2010 at 1:03 pm #

    Well Brian’s take on this seems to ignore that listeners are leaving radio in general because of the lousy programming…not because of reception issues. I doubt that raising a station’s ERP to 10% of its Analog signal level will do much to increase listnership. That is because nobody is listening to begin with. FM IBOC is a solution looking for a problem. Having ACTUALLY WORKED for AM/FM and college stations I have heard these arguments before. In the 1970s PDM (Pulse Duration Modulation) was going to be AM radio’s savior. In the 80s it was AM Stereo (C-QUAM). Now it is IBIQUITY and AM IBOC which is on a long slow road to nowhere. That is because there is no local programming and radio programming in general leaves much to be desired. Oh… I almost forgot to mention… AM IBOC Interference? People are voting with their feet, or more specifically with their I PODS or satellite radio. Many stations are programming the same crappy programming on the HD signal as they have on the analog signal! AND as for “crystal clear” reception the analog signal is still stronger.
    Plus if a station has 3 HD channels the HD signal will not necessarily be CD quality on all 3 HD channels owing to the limitations of IBIQUITY’S system.
    And the assertion that interference will be minimal on FM ignores that the buffer of 400 Khz between stations is now reduced! How can it not cause interference? Just look at WJFK & WRQX in the DC Metro area and the problems that is causing. The 10 % of analog signal strength increase may not cause interference in ALL cases, but to low powered FM stations it WILL cause interference issues. Naturally they will wiggle out this by pointing out that many low powered stations do not get service contour protections to any significant degree. The problem with that argument is that it is not an argument in the public interest but rather in IBIQUITY and the NAB’s interest. The lack of service contour protection was an older argument (and FCC rule) based on ERP and Antenna height… not by changing the rules in the middle of the game by cutting back the 400 kHz buffer. Yes the NAB and IBIQUITY have the FCC well house trained!

  8. Eric October 19, 2011 at 11:56 pm #

    Quality matters: Both content and sound quality. If NPR can’t have money from the public trough, let them have their way with their tiny slice of the RF spectrum. For the quality of programming they offer, and the work they put in to scrape up enough cash from their listeners to survive, they deserve it. Even with a great tuner, music via analog FM sounds horrid compared to even the lousiest compressed low bit-rate satellite stream, cheapie cd player, or ipod/mp3 player. Hearing NPR in crystal clear HD, and having more of the “same flavor” to choose from, via the 2nd, 3rd feeds from the couple of stations I find palatable, drove me to buy an HD tuner for both car and walk-around. Alas, from 2007 til recently, they’ve proven near useless until the power increase…. I’ll be buying a new HD tuner to replace the old JVC KD-HDR1 I gave away now that I see the new owner gets geat reception! I frankly find it difficult to complain about interference / noise on analog FM, since it sounds so lousy to begin with. As for the low power / college stations, are there really any adjacent high-power HD broadcasting rivals? Seems most of the content both in Chicago and Detroit,as well as everywhere I’ve tuned in on a road trip are quite a bit further up the dial, with the exception of NPR, which is still a couple “stations” away from any college station I’ve ever stumbled across. Broadcast formats come and go, equipment becomes obsolete… sometimes for no good reason, but more RF power for superior sound quality, and a bit more variety, at the debatable expense of poorer reception / sq when using legacy equipment seems a move in the right direction.

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