BCA Show Preview - 62

SUNTEC SINGAPORE

A part of

MARINA BAY SANDS * SUNTEC SINGAPORE

SHOW PREVIEW | 26-28 June 2018

Top Considerations when
Transitioning to Digital Radio
Cost, backwards compatibility and frequency availability are just a few of the
issues to ponder when implementing digital radio technology, says Chuck Kelly,
Nautel Sales Manager Asia-Pacific...

he implementation of digital radio
technologies on a global scale is not
a simple equation. Many factors play a
part as each region and country chooses
its standard. These include issues such
as backwards compatibility with existing
analogue receivers and spectral masks, the
availability of frequencies in larger markets,
the short- and long-term costs of broadcast
infrastructure conversion, receiver availability
and cost, the practicality of a transitional
hybrid approach, and the roadmap for future
all-digital broadcast. It is also important to
consider the effects of each option on the
financial health of the public and private radio
broadcasters involved.

sold every year. The economies of scale
mean that HD Radio cost is quite reasonable,
not much of a premium over an analogueonly radio. Car receivers, portable and home
receivers are available and HD Radio in
cellphones is just beginning to be available.
DRM+ radios, on the other hand, are not
being produced in mass-market quantities at
present, and the costs are still quite high.
Most receivers made for HD Radio FM also
support medium wave, although HD Radio
on medium wave has not been as successful
as it has on FM. Again, the analogue signal
has digital subcarriers on both sides but with
medium wave, only a single digital channel
is carried, the digital representation of the
analogue signal.
While the HD Radio medium wave signal
meets the FCC spectral mask, it does cause
interference to adjacent stations, and many
stations have turned it off. Outside of North
America, medium wave has little penetration.
DRM on the contrary uses the whole channel
for the digital signal and doesn't encroach on
adjacent frequencies.

The Options
Traditional medium wave and FM bands
offer many advantages. They provide
good building penetration and portable/
mobile performance, while a wide range
of equipment both for the receiver and
transmitter end are available at low cost.
Most
importantly,
however,
these
frequencies are already allocated to
broadcast in most regions of the world. It's
hard to beat the cost efficiency of medium
wave and FM broadcasting, especially as
compared to satellite, internet or cellular
broadcasts.
In some countries, the lack of available
frequencies has led to one or more new
bands being allocated, and DAB or DAB+
has been implemented. But this decision may
have drawbacks in many parts of the world.
Suppose you own an FM station and
the decision to implement DAB in your
area is made. Now you must buy a spot
in the multiplex, but you can't just stop
broadcasting in FM because digital receivers
aren't sufficiently available on the market
- and it may be years before you can shut
it off. That means your transmission cost is
increased.
Meanwhile, in many cases, DAB coming to
a market has brought with it new competitors
to your station. The advertising pie in your
market didn't increase in size, and the slices
each station makes are smaller. Thus, along
with increasing expenses, revenue will most
likely decrease - not a healthy prospect.
This is not the case with alternative in-band

All-Digital Receivers

technologies Digital Radio Mondiale and HD
Radio. Each standard has its advantages,
and despite geographic, political and revenue
model differences, they are remarkably
similar technologies. Both DRM and HD
Radio can be used to upgrade existing
analogue transmitter systems to digital, both
are well proven and accepted by international
standards bodies and both utilises the
existing medium wave and FM bands.

In-Band Technologies
HD Radio FM is a hybrid approach, where
sets of digital sidebands are added to either
side of the analogue signal, and the whole
thing fits in a spectral mask that meets
standards in most countries. If you have an

Multiple stations can be transmitted
on a single HD Radio FM transmitter

analogue-only radio, you will continue to hear
the FM analogue signal as before, but if you
have a new HD Radio receiver, you will hear
the analogue signal in addition to a higherquality digital representation of that analogue
signal, plus (optionally) several more digital
stations.
In DRM+, the VHF version of DRM, a
narrower digital-only signal is broadcast,
which fits into the small blank spaces in
market dial and potentially can have more
than one channel.
The primary difference is in receiver
availability. There are tens of millions of HD
Radio receivers in the market, albeit mostly
in the United States, and millions more being

Another key point is that ITU Region 2,
which consists of the Americas, has 10 kHz
frequency steps, while Regions 1 and 3 (the
rest of the world) operate with 9 kHz steps.
HD Radio is optimised for 10 kHz steps, and
DRM is equally comfortable in either.
An additional consideration is the longerterm question: When will digital receivers
allow for all-digital operation? Nautel has
developed HD Multiplex, which allows up
to 15 stations to be transmitted on a single
HD Radio FM transmitter. These signals can
be received on most current HD receivers,
bringing significant advantages in spectral
efficiency, operation cost and radio's ability
to compete with a multiplying number of new
formats available over the Internet.
Ideally, the millions of new receivers
being produced each year would include
both HD Radio and DRM. While this isn't
without some challenges, chipsets are today
available that support both, and it would
permit broadcasters to select the technology
that best fits their market for both medium
wave and FM.
www.nautel.com

http://www.nautel.com/solutions/advanced-solutions/hd-multiplex/?utm_source=InBroadcastBCAshowDigitalPreview&utm_medium=Article&utm_campaign=HDmultiplex http://www.nautel.com

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