Tag Archives: AM revitalization

AM Revitalization: DRM Consortium asks FCC to adopt DRM

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Many thanks to SWLing Post contributor, Alan, who shares this editorial from Radio World that features edited comments filed with the FCC by the DRM Consortium.

The following unedited letter was taken directly from the FCC comments database:

(Source: FCC Filing [PDF])

In your document (FCC19-123) you rightly highlight the great advantage of AM broadcasts, primarily the ability to cover large areas and number of listeners, while the band itself is losing popularity because of a variety of issues to do with propagation, interference, environmental changes. At the same time, digital audio broadcasting is no longer the new platform it was in 2002. At that time FCC mandated a proprietary system (IBOC, “HD radio”) as the only system to be used in the USA with the possibility of applying DRM for HF.

Since then DRM (the ITU recommended, only digital audio broadcasting for all bands, open standard, has been tested and used all over the world on all bands, short wave, medium wave and FM).

So while you are recommending now pure digital HD, based on the NAB tests and WWFD not completely convincing trial, we would urge the FCC to consider opening the straightjacket of 2002 and allow DRM to be used as a sure, tested, efficient way of digitizing the AM band.

There are several reasons for this:

DRM digital radio delivers in the AM bands significant benefits:

    • Audio quality that is on par or better than FM. DRM of all recognized digital
      standards is the only one using the ultra-efficient and compressed xHE-AAC audio
      codec that delivers at even very low bit-rates exceptional audio quality for speech
      but music, as well. (https://www.drm.org/listen-compare/)
    • Record Data: DRM has been tested in medium wave all over the world in both
      simulcast and pure digital. A list of the main tests (some of which have become ITU
      adopted documents) are included in Annex 4 of the DRM Handbook:
      https://www.drm.org/wp-content/uploads/2019/02/DRM-Handbook.pdf
      At the moment, 35 MW transmitters are on air in simulcast or pure DRM in India.
      http://prasarbharati.gov.in/R&D/
    • Auxiliary Data. DRM is the newest, most complete, open standard for digitizing radio in
      all frequency bands, and is recommended by ITU. DRM has been devised as a direct
      heir to analog AM (SW, MW). It uses 9/10, 18/20 kHz bandwidth and has a useful content
      bit rate of up to 72kbps. It carries up to 3 programs on one frequency and one data channel, while data can be carried on each of the audio channels as well. One of the great advantages of DRM is that alongside excellent audio, the receiver screens will display visual information of any kind required (albums’ titles, singers’ photos, maps, visuals of any sort, data of any kind). The Journaline application allows for extra information from the internet or the RSS feeds of the broadcaster to be captured and displayed. Currently broadcasters like the BBC, All India Radio, KTWR in Guam are using this extra facility that clearly differentiates digital form analog as a superior option.
    • Power/energy efficiency. Using SW or MW in DRM can reduce the power used up
      to 80%). As per calculations made by Ampegon, a medium wave transmitter can
      cover an area of 235000 sq km with a 100kW transmitter. The DRM EPR of such a
      transmitter is about 50kW and the coverage area is the same, while instead of one
      analog programme up to three digital channels and one data channel can be
      broadcast, all in excellent audio quality.
    • Spectrum efficiency (more programmes can be broadcast on one single frequency
      used for one programme in analog) as explained above.
    • DRM, unlike analog, offers enhanced and stable audio quality that is FM-like
      (mono or stereo). DRM also offers multiservice data enabled by applications like
      Journaline (the enhanced text services, more information captured as RSS feeds or
      form other internet source), slideshows, multilingual text (practically being able to
      show any characters of any language not just Latin script), and the Emergency
      Warning Functionality (EWF) in case of disasters.
    • Interference. This has not been noted as the DRM signal will always be lower than
      the analog one. AIR has not noted any interference in its operation of DRM
      transmitters. The mask values required for an optimal functioning of DRM
      transmitters is clearly stipulated in the ITU documents and as long as the network
      planning is correct, and the mask is respected there should not be any issue of
      interference in digital-analog or digital-digital DRM transmissions.
    • Receivers. Currently there are several receiver models and SDR options for the
      reception of DRM in AM. India has almost 2 million new cars fitted with DRM
      receivers, at no cost to the buyers, that are capable of and are receiving DRM
      mediumwave signals. The audio quality is excellent and a sure benefit to the users.
    • DRM is in direct succession to the analog AM (and FM) services, not owned or
      controlled by any single company and immediately available with full know-how and
      technology access by the transmitter and receiver industry.
    • As HD in mediumwave is a bit of a necessary step but still a leap in the dark, it
      would make sense from the practical aspects and even receiver solution availability
      to allow DRM as the best, clearly proven solution of digitizing the AM band (in
      preference or alongside HD) in the US.

In short, the salient advantages of DRM are:

    1. The audio quality offered by DRM is equally excellent on all the transmission bands:
      MW, SW or VHF
    2. Robust signal unaffected by noise, fading or other forms and interference in all bands
    3. Clear and powerful sound quality with facility for stereo and 5.1 surround
    4. More audio content and choice: Up to two and even three audio programmes and one
      data channel on one frequency
    5. Extra multimedia content: Digital radio listeners can get multimedia content
      including audio, text, images and in future even small-scale video, such as:

      • Text messages in multiple languages
      • Journaline – advanced text-based information service supporting all classes of
        receivers, providing anytime-news for quick look-up on the receiver’s screen;
        interactivity and geo-awareness allowing targeted advertising
      • Electronic Programme Guide (EPG), showing what’s up now and next; search
        for programmes and schedule recordings
      • Slideshow Programme accompanying images and animation
      • Traffic information
    6. Automatically switch for disaster & emergency warnings in case of impending
      disasters in large areas, automatically presenting the audio message, while providing
      detailed information on the screen in all relevant languages simultaneously. Great
      potential to become the surest and widest means of alerting the population to
      emergencies.

Therefore, we urge FCC to take a wide view and consider all options including DRM, if AM is worth futureproofing in the USA.

[This filing also included a number of “Useful Press Links]

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Peter Tannenwald asks, “Are we really ‘revitalizing’ AM?”

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(Source: RadioWorld via Bill Patalon)

On AM revitalization, Peter Tannenwald asks, Are we really “revitalizing” AM, or are we walking around in circles?

Late on Friday, October 5, the Federal Communications Commission (“FCC”) released a Second Further Notice of Proposed Rulemaking in a five-year ongoing effort to “revitalize” the AM radio broadcast service. The new proposals continue a trend toward allowing higher power operation by smaller stations, by reducing nighttime signal protection for some 60 Class A AM stations located in the continental United States and 16 stations in Alaska. The end result would be less wide area coverage and more local radio service to the public.

To understand why the FCC is considering this action, it helps to understand a bit of the science behind AM signal propagation. AM radio signals travel through both the ground and through the air. At night, the airborne signal component (“skywave”) is reflected back to the earth from the ionosphere — a layer of the atmosphere extending from about 50 to 600 miles above the earth’s surface. The reflected signals may come back down to earth hundreds, if not thousands, of miles away from a station’s transmitter. Class A AM stations — formerly known as “clear channel” stations (no relation to Clear Channel/now iHeartMedia) — are powerhouses, transmitting with 50 kilowatts of power 24 hours a day – 200 or more times the power of the smallest AM stations.

[…]Signal reflection doesn’t work so well during the day, so the FCC has allowed other stations to occupy the Class A frequencies in other markets. But those stations have to curtail power during “critical hours” (two hours before sunrise and after sunset) and often have to reduce power to nearly nothing or shut down altogether at night. In today’s 24-hour-a-day, nonstop world, not being able to reach an audience at night is a losing proposition; so the FCC has yielded to constant pressure over the years to allow more power and longer hours of operation by those “other” stations, at the expense of long distance reception of Class A signals.

Now the FCC is proposing to go further, rolling back some previous restrictions on non-Class A AM stations and perhaps eliminating whatever remains (and it’s not much) of the protection of far-away reception. Under the proposals, which are sufficiently complicated that you should talk to your engineer if you really want to understand the details, Class A AM stations would be protected only within a higher strength signal contour (and so within a smaller area) than they are now; at least some, if not all, skywave protection would be eliminated.[…]

Click here to read the full article at RadioWorld.

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AM radio proposal has Class A broadcasters upset

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WHKY-AM-Radio-Tower(Source: Times Union)

When the sun goes down, AM radio signals travel much farther. You can listen to 50,000-watt stations such as WGY hundreds of miles away.

But that could soon change, if the Federal Communications Commission goes through with a plan to let more local stations broadcast through the evening hours and potentially makes changes in the daytime signal of WGY and other powerful stations.

The proposed change in protections to Class A stations such as WGY would ease restrictions on the smaller stations, which are now required to reduce power or change the direction they broadcast their signal so they don’t conflict with the more powerful Class A stations.

WGY has begun an online petition drive to oppose the changes.

Called “Save AM Radio,” the petition opposes reducing WGY’s so-called “protected service area.”

The changes, WGY says, “will make it very difficult for many of our listeners to receive our programming, especially at night and during morning and evening drive times.”

[…]The FCC, meanwhile, says the changes are being considered in an effort “to help revitalize the AM service.”

More local stations would give listeners a wider choice of programming, supporters of the change argue.

[…]WGY’s online petition is at http://www.wgy.com/features/save-am-radio-1919/
The FCC is accepting comments through March 21 and replies through April 18, at www.fcc/ecfs. Click on “submit a filing.” The proceeding number is 13-249.

Read the full article at the Times Union online…

I’m very curious what Post readers think about this proposal from the perspective of both access to regional information, as well as from MW DXing. Will this move crowd the AM broadcast band or give local stations a stronger voice?

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