Radio stations have  paid  royalties to composers for playing music on the air, but not to the performers.  This is because radio has traditionally been a great way for performers to promote their music.  That logic is no longer so firm, now that websites, streaming services and music appliances compete with radio for the music listener’s ears.

The NAB initially responded to the calls for radio to pay performance royalties by labeling the royalties as a “tax”.  This didn’t get much traction with Congress who saw through the disingenuous claim.  It might have been that the record labels had a better lobby than the NAB.

A number of big broadcasters finally came to the conclusion that stonewalling the royalty tsunami was not going to work, so they sat down to get the best deal they could.

The crux of the draft is that broadcasters will pay royalties a lower rate than webcasters and other distributors, and to sweeten the deal, they tossed in an additional wrinkle:  Require FM radios in every cellphone.

This kind of protectionist ploy never works out in the end.  There are a raft of reasons why this is a BAD IDEA.

• First and Foremost – AM Radio gets no cellphone radio – AM music stations pay the royalties, but get no sweetener.
• The deal is for FM Analog radios – Not Digital radios – effectively crippling deployment of  HD Radio
• The cellphone buyer has to pay for an FM radio raising the cost of the cellphone
• The cellphone has to have an FM radio even if the phone has only a tiny speaker or no headphone jack
• Tiny FM radios without a headphone connected have terrible sensitivity, giving the listener a bad experience with FM Radio
• Cellphones will have the cheapest FM radio possible giving the listener an even worse FM Radio experience.

The first two factors are critically detrimental to broadcasting.  The balance of the problems set up radio for a bad user experience, driving listeners to more reliable and satisfying choices.

All AM broadcasters and broadcasters who have invested in HD Radio need to let the NAB know that they think that this is a BAD BARGAIN for radio, and let your Congressmen know that this kind of protectionist scheme is not in radio’s long term interest.

This means that the DRM simulcast signal will occupy LESS bandwidth than a normal AM 10 kHz analog signal.  Good-bye first adjacent channel hash!  The DRM signal described in US Patent 7170950.

The technique starts by bandlimiting the analog signal to 5 kHz and forming it into a modulation that has the structure of Leonard Kahn’s “compatible single sideband” from the early sixties.  The big difference is that today we can use a Digital Signal Processor (DSP) to perform the job that Leonard’s analog gear could never quite get right and stay in alignment.  The DSP can also learn the transmitter distortions and compensate for them.  The DRM signal is a high level OFDM spectrum of the same magnitude as the average analog modulation (not some little trashy signal on your neighbor’s front porch) that is placed in the unoccupied sideband.

The ODFM signal will interfere with the analog sideband, you say!  Here comes the elegant part – A mirror image of the digital signal is placed under the analog sideband.  This signal, when received by an envelope detector, will cancel out the ODFM signal in the other sideband!

Apparently, the tests in India went well, with the analog signal receiving no apparent self-interference, and the digital signal having somewhat more range than the analog signal.  On the face of it, the analog signal should perform similarly to a well adjusted Powerside ® facility.  Remember, compatible single sideband does not intrinsically decrease modulation power, as the total amount of power is doubled in the one sideband.  Regular transmitters will not be able to produce the same analog power in a combined modulation scheme because the ODFM sideband power must be included in the peak power that the transmitter develops.

Important considerations of this system:

• Intrinsically single channel – digital sidebands stay within assigned channel
• No adjacent channel interference
• Digital signal range exceeds analog range for single digital program
• ODFM carrier strength is high, providing lots of data capacity in a narrow bandwidth
• Analog reception works fine with a conventional envelope detector
• Decoding the digital signal is very simple in a non-fading environment.
• A Zero-IF receiver with a sound card class Analog to Digital converter and slow DSP will be able to decode simulcast DRM.
• Cheap digital receiver with potentially only two chips and no ceramic filters.
• Low power battery powered radios are practical
• Probably will work with 8 – 10 kHz analog audio in the US
• Current class of DSP digital transmitters may be reprogrammed to transmit this signal.
• Should work will in Single Frequency Networks.

I am surprised that this development has not been publicized here, as this promises to be the first truly workable analog-digital broadcasting system for the AM band.  AM broadcasters have been left out in the cold, with no battery powered medium wave digital radios.  This technology might just be the solution.

I find this news heartening, seeing the slow to non-existence of growth in AM HD.  Perhaps a little competition on the technical field will help AM broadcasters to have a stake in the future.

XEEZ 970 Radio Palacios is broadcasting an AM HD Radio signal from the U.S./Mexico border town of Caborca, Sonora, using a Broadcast Electronics transmission system.

XHTY-FM 94.5 in Tijuana on the FM Side has installed a Nautel V10 HD Radio transmitter. The station is operated by Uniradio.

• Red – 3.0 mV/m – Generally the Sellable area of the station
• Purple – 0.5 mV/m – Rural protected service area, but nobody would buy ads.
• Blue – 0.1 mV/m – You might still get it on a car radio

For FM they are:

• Red – 60 db/uV or 1.0 mV/m – Protected service area for Class A and C stations
• Purple – 50 db/uv or 0.316 mV/m – A pretty weak Signal, nobody would buy ads.
• Blue – 40 db/uv or 0.1 mV/m – You won’t pick it up, except in rural areas

I determined this by comparing the plots of sample stations in Radiosoft’s Comstudy with their Radio-Locator maps. Hopefully this clears a few things up!

Official statement (translated):

“Considering the extent of the development and implementation of the IBOC system in the United States of America, Mexico is required to take decisive action so that [the country's AM and FM radio stations] in the zone located within 320 kilometers of the northern border of Mexico can transmit at the same technological level so that they can provide the benefits of quality service to the radio listening public.”

The NRSC also adopted a guideline for recommended bandwidth for AM transmission. NRSC-G100 provides guidance for operators who would like to decrease first adjacent channel interference by operating with bandwidth narrower than the 10 kHz limit. Using the full 10 kHz bandwidth is lost on most receivers, as nearly all receiver IF filters limit audio response to much less than 10 kHz. Benefits from this technique are limited to cases where the licensees mutually agree to bandwidth reduction of stations that interfere with each other.

This is one more bump in the road for digital Medium Wave Broadcasting, but I think that our neighbors south of the border are probably just reserving their places at the table. I have heard that at least one Mexican station has begun broadcasting in IBOC.

• The report finds: Internet radio listening has increased 50% in the last year
• Internet radio reaches 19% of 18-34′s weekly
• Both XM and Sirius are recognized by more than 60% of the public
• Satellite listeners are an upscale audienc: 27% have incomes over $100k
• There is confusion between podcasting, internet radio and downloadable music
• More than half of those who have listened to podcasts are under 35, and 20% under 17
• Interest in HD radio is up: 8% very interested, and 27% more are somewhat interested
• Most people report the desired price point for an HD receiver at $50 to $100
• 77% of listeners report that they expect to listen to the same amount of AM and FM radio as they do now
• Digital radio users have not decreased the amount of time they spend listening to AM and FM radio