July 28, 2005
Revolution on the Radio
By GLENN FLEISHMAN
NY Times
http://www.nytimes.com/2005/07/28/technology/circuits/28basics.html?pagewanted=print
Plug a set of headphones into a radio tuned to an FM jazz station. Hear the
hiss at the bottom of the range and the fuzz at the top. Remember why you
like compact discs.
But don't be impatient: wait eight seconds. An "HD" light appears on the
tuner. And now the bottom drops out. The hiss turns to silence. The stereo
channels separate, opening a cramped room into a performance hall. And the
high fuzz is now crisp high notes from a trumpet or Ella Fitzgerald.
You have just heard terrestrial digital radio. Or you would have - if you
could get your hands on a receiver.
Satellite digital radio has captured the attention of consumers and
investors with its billions spent and millions of paying subscribers. But a
quiet digital revolution has hit the AM and FM dials as well: more than 450
stations in the United States now broadcast one or two digital channels
alongside analog ones. At least 2,000 of the more than 12,000 stations in
the country are committed to adding the format.
The technology to make this happen - called in-band on-channel, or IBOC -
hides digital signals at low power in the spaces between stations. Only one
company's technology has been approved by the Federal Communications
Commission: HD Radio from iBiquity Digital. (IBiquity says HD does not
stand for high definition - or anything else.)
Digital AM sounds like present-day stereo analog FM. Digital FM not only
improves fidelity and stereo reception, providing a dynamic audio range
approaching that of a compact disc, but also makes use of enough bandwidth
to allow multiple channels.
An HD Radio tuner takes eight seconds to lock onto and start playing a
digital stream; the analog broadcast seamlessly switches into richer audio,
providing a demonstration of its improved quality.
Unlike satellite radio, digital AM and FM are free to listeners. But only a
few tens of thousands of car tuners equipped to decode the signals have
been sold in the 18 months since the first product was shipped, according
to Dan Benjamin, a senior analyst at ABI Research in Oyster Bay, N.Y. Home
tuners are just reaching the market.
How Digital Radio Works
IBOC uses a part of the spectrum just outside the frequency used for a
radio station's conventional signals.
HD Radio is capable of great range with a small fraction of the power of
analog radio. In a test by National Public Radio and WNYC-FM, a 57-watt
transmitter on the Empire State Building reached almost all of WNYC's
coverage area, with a population of 16 million, according to Mike Starling,
NPR's vice president for engineering.
The technology sends multiple streams of data over very narrow frequencies
to solve the problems of analog AM and FM reception. The streams are
separately received, synchronized and assembled by the radio tuner.
In AM, this avoids having signals fade in short tunnels and will prevent
noise from electrical motors. "It gets rid of the majority of problems with
AM radio," said Thomas R. Ray III, director of engineering for Buckley
Broadcasting and WOR-AM, a commercial talk-radio station in New York that
has added digital transmissions.
With FM stations, multipath reflection can be controlled with HD Radio,
avoiding audible echoes from signals bouncing off buildings. "You don't get
that sort of 'fumth-th-th-fumth' sound," said Stephen Shenefield, director
of product development at Boston Acoustics, an audio equipment manufacturer.
FM radio has a larger spread of unused spectrum, and National Public Radio
and public radio stations successfully pushed the F.C.C. to allow
multicasting, or multiple digital channels of different quality for
existing stations. The F.C.C. allows a second digital channel with a
waiver; up to five channels may be permitted in the future.
What's On
Public radio produces much more programming than its member stations can
broadcast: 300 hours a week, Mr. Starling of NPR said. NPR is now offering
five full-time music streams to stations for HD Radio multicasting as well.
"If we had more shelf space, we could do more format focusing," Mr.
Starling said.
KUOW-FM in Seattle broadcasts what it calls KUOW2, a full slate of reruns
of local and network programs with a dedicated host.
Commercial broadcasters, too, are taking note. Clear Channel, which owns
1,200 stations, says it is committed to taking 95 percent of its stations
in the top 100 markets digital within three years. Among the attractions is
HD Radio's ability to deliver data streams alongside audio. The system can
already carry program-associated data, like a song title, artist and album
name. But the capacity exists for much more.
Robert J. Struble, chairman and chief executive of iBiquity, noted that the
text of advertising messages could be synchronized to display on a radio's
readout as a related commercial was broadcast. Other uses include traffic
updates for car navigation systems and private commercial data transmissions.
A future version of the technology will feature a data uplink that could
let stations have a "buy now" button for songs. "There's no better place to
make an impulse purchase than when I'm sitting in traffic," Mr. Struble said.
HD Radio has the potential to limit access to certain channels by receiver
serial number, much as with satellite digital radio, so that specific
programming could be delivered for a fee.
Mr. Starling mused that the "buy now" button might read "pledge now" for
public radio stations, and that a station could allow only listeners who
donate funds to tune to a digital channel free of fund-raising during
pledge drives.
How to Listen
HD Radio was limited to car receivers from its retail introduction in
January 2004 until June 2005. The earliest HD Radio manufacturer, Kenwood
(kenwoodusa.com), now has 40 models compatible with a $399 HD Radio
adapter; other makers have a few products released, but a flood is in the
pipeline. A representative of Visteon, a major automotive systems supplier,
said automakers could offer HD Radio as an option in the 2006 model year.
Yamaha (www.yamaha.com) released the first home radio in June, its RX-V4600
($1,900), a home entertainment centerpiece. In tests of all Seattle-area FM
HD Radio stations using the Yamaha unit, the results were breathtaking.
Tuning in secondary multicast channels, however, required use of the remote
control and was awkward.
Three companies plan simpler tabletop tables, each of which will add
multicast digital stations sequentially: turning the dial will tune through
those secondary stations.
The Radiosophy receiver docks in a speaker unit; together, the two parts
cost $259 direct from the company, including shipping. Radiosophy expects
to offer a car adapter kit later. The receiver includes analog and digital
optical outputs. The company (www.radiosophy.com) expects to ship the
product in September.
The Recepter Radio HD ($499) made by Boston Acoustics (www
.bostonacoustics.com) has a single built-in speaker and a satellite speaker
to produce stereo audio. It is also a clock radio, and has stereo input and
multiple outputs. The radio should be available in late August.
Polk Audio has built HD Radio into a more elaborate all-in-one
entertainment system that includes a CD and DVD player and speakers, and
multiple inputs and outputs. The $599 unit, called the I-Sonic, is also
equipped for satellite XM Radio through a plug-in module. Polk Audio has
delayed shipping until late in the year (www.polkaudio.com).
No one in the industry expects to replace a billion analog radios
overnight. Even Mr. Struble of iBiquity put the most optimistic date for an
analog shutdown as 12 years from now, though he thought that was unlikely.
Still, there are already listeners, however few. "The last time we had to
shut down the HD - off for any reason - we had eight phone calls," Mr. Ray
of WOR said. "People wanted to know why."
================================
George Antunes, Political Science Dept
University of Houston; Houston, TX 77204
Voice: 713-743-3923 Fax: 713-743-3927
antunes at uh dot edu
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