author is senior vice president, Broadcast Programs and Services,
for iBiquity Digital Corp.
been more than 90 years since KDKA(AM) in Pittsburgh became the first
commercially-licensed radio station in America, and the technology of
AM broadcast has not changed significantly since then. Compare the
cars, trains, telephones and motion pictures of the 1920s to today.
a simple crystal radio, made with a hunk of galena crystal and 50
feet of copper wire wrapped around a milk bottle, and a pair of
headphones, were all you needed to receive your local AM station.
Other than the occasional thunderstorm, there was no electrical
interference to speak of.
to today. Manmade electronic noise on the AM band has increased to
the point that many regional and local channel AM signals are
severely compromised, and even the Class “A” 50 kW clear channels
are suffering from noticeably diminished coverage.FCC Commissioner Ajit Pai recently stated, “Every
day it gets harder to pick up a clear AM signal.”
out as the only service in the car that currently can’t display
even analog artist and title data. AM becomes the ‘blank screen’
in the dash — the only ‘unconnected’ part of the connected car.
This example is from the Cadillac Cue system on a 2013 ATS.
revitalization is all about addressing this noise issue, and HD Radiodigital technology has proven to provide a
cost-effective path to allow AM radio to evolve, giving it a fighting
chance at survival.
want to prematurely sound the death knell for the senior band since,
after all, five of the 10 top-billing radio stations in America are
still AM; but outside the largest markets, AM listening has been
largely relegated to talk or oldies formats and shrinking, aging
audiences, and consequently diminished billing. Digital radio
transmission provides a potential long-term solution for AM radio’s
ability to improve reception in noisy conditions can help make the
band viable again, and also allows for quality stereo music
broadcasts that AM radio’s early pioneers could only dream of.
All-digital AM, thanks to its time-diverse encoded content, increases
signal durability and robustness in many of today’s challenging AM
remain viable as electrical interference continues to increase,
limiting reception possibilities and, by definition, potential
audience? According to the FCC, until 1978, AM claimed more than half
of all hours spent with radio. Right now, AM listening accounts for
only 17 percent of radio listening, and continues to diminish every
median age of listeners to the AM band is now 57 years old, a full
generation older than the median age of FM listeners. We’ve already
seen broadcasters giving AM stations away to charity, selling them
for the real estate value of the land they sit on or just handing
back their licenses to the FCC. At today’s current rate of audience
erosion, many AM operators can plot the day their station goes out of
business, the day rising operating costs exceed shrinking revenues
and another AM is forced to go dark.
all-digital AM broadcast environment, where the broadcast is solely
digital, would be vastly superior to analog or even hybrid digital
AM, where digital and analog exist side by side. The more robust
all-digital signal creates a better reception environment, as well as
less potential for co-channel interference, which is also a source of
designed the hybrid approach as a transition technology, one that
wisely didn’t orphan today’s receivers while waiting for digital
receiver penetration to reach critical mass in the marketplace.
All-digital AM holds the promise of a return to the pristine band
that existed before electronic noise became an issue, a return to the
full coverage of your service area your license entitles you to, with
the added benefit of stereo and increased noise resistance. With AM’s
share of listening declining, the future viability of the AM band
overall may well lie in owners taking advantage of the opportunity
that the HD Radio AM all-digital system provides.
all-digital transition won’t happen overnight. It took TV 13 years
and a government mandate to fully make the changeover. But TV station
owners collectively spent some $10 billion of their own funds
switching from analog to digital, partly based upon the value the
additional digital spectrum (multicast channels) would have for them.
And with HDTV digital transmissions limited to 20 percent of analog
power, the savings in electricity represented a significant savings
going forward. With new digital TVs being sold everywhere, they
finally acknowledged that all-digital media was the future, and they
invested in that future.
there are over 12 million HD Radio-equipped cars throughout America,
with a new car with factory-installed HD Radio technology being sold
every six seconds, 24/7/365. Every one of
these radios already support HD Radio AM all-digital reception.
More than 4.5 million cars will be sold this year alone with an HD
Radio digital receiver on board — AM as well as FM.
and more people waking up to their cell phones and abandoning clock
radios, and table radios and portables becoming a thing of the past,
the automobile will be the place where analog AM radio makes its last
stand, or allows alternative technologies to render it irrelevant. To
put that in a larger context, bear in mind that radio is now the only
consumer medium that is not delivered to its users exclusively via
all-digital solution was always “baked into” HD Radio Technology,
so existing transmitters and HD Radio receivers are capable of
receiving an all-digital signal. A comprehensive, independently-run
test program was initiated to evaluate the operational performance of
all-digital AM broadcasts. Testing in Charlotte, N.C., with CBS
yielded test results showing digital coverage beyond the 0.5 mV/m
(field strength) coverage contour with no reduction in stereo audio
quality. Solid all-digital mobile reception extended up to about 45
miles daytime / 13 miles nighttime, which corresponded to an average
measured field intensity of 0.2 mV/m and 0.7 mV/m respectively. In
layman’s terms, all-digital coverage was superior to analog
won’t be easy, and it will come with some cost. This is a decision
only the broadcasters involved can make. We’ve created a digital
way forward, worked out the kinks and shown how it addresses the
noise problem threatening AM’s future. We believe the industry
needs to complete its ongoing evaluation of AM all-digital
performance, assess the options and move forward quickly to
revitalize the AM band and ensure that this vital national asset can
continue to serve the listening public for many years to come.
remains committed to serve the broadcast industry and do all we can
to help ensure a strong vibrant digital future for broadcast radio.
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