Streaming Audio: The New Mobile Distribution Frontier?
IP streaming to the car replace broadcasting? Is the public Internet
the technology that will soon and forever replace FM radio, as FM
replaced AM in its turn?
Motorola Photon is shown with the Pioneer DEH-9400BH car receiver.
Audio from the phone is linked via Bluetooth to the car receiver,
with the side benefit of providing a hands-free method for phone
I’ve caught a number of articles and news pieces discussing audio
streaming that indicate it’s finally getting some legs. As noted in
a recent article in Radio World,
an NPR Labs study seems to test the range of reliability in the
bandwidth and to find the appropriate codec to occupy that bandwidth.
No matter how you approach streaming, the issue always will come down
to bandwidth, reliability and availability in mass simultaneous
is no question that cellular data growth has gone through waves of
good and bad. This ExtremeTech article suggests that while consumers are demanding new data capacity at an
increasing rate, cell phone carriers are currently just barely able
to stay ahead of this demand and the requirement for constant
been streaming audio for nearly 14 years now and have had firsthand
experience with its issues.
have always streamed audio for the purpose of personal listening
while traveling locally in my car or when afar. I started out
tethering, then using data cards with laptops and Winamp as my
player. When I got my first (Palm) smartphone, I started using that
and have been using the handheld devices since. I have had a Motorola
Photon dedicated to my car since it came out, primarily for
streaming, but it simultaneously serves as a GPS and a hands-free
phone via its Bluetooth connection to my after-market Pioneer
DEH-9400BH CD/AM/FM HD Radio.
the years, the cellular industry has moved data pricing steadily
upward. Some have offered unlimited data plans on their phones but
stop short of providing that for tethering, hot spots and their
tablets. When you consider the amount of data you can rack up in a
month, it can be a challenge to stay below your data plans cap. This
can quickly become expensive if you don’t choose the right plan and
stay diligent of your use or have an unlimited data plan. It is
certainly a deterrent to the technology taking flight when the
customer realizes the cost for data usage is more than that of a
addition to cost factors are the reliability of the networks and the
availability of needed bandwidth. Users have seen great reductions in
bandwidth availability, with massive sales of new hot Apple and
Android device releases, as well as carriers throttling back the
speeds for known heavy users. Additionally, the technology itself has
not really been developed or optimized for the “continuous,
uninterrupted” delivery of data. The occasional email check,
website visit, etc., does not require a continuous flow of data.
Spurts of data back and forth are typical and occasional network
latency doesn’t affect these uses, but it is not at all good for
streaming. So, today we still deal with dead spots in data coverage
and multiple networks (3G/4G/LTE) that don’t deliver
streaming-capable coverage in 100 percent of a particular town or
is coverage less than complete? Switching from site to site has long
not been a problem,
unless there are coverage gaps or bad hand-offs. However, newer
networks take time to build, and are slowed with backward
compatibility in some cases, so the coverage starts out and remains
spotty for some time until the new technology can be implemented
fully. This is an issue for streaming media, as I’ve not found any
of my phones capable of switching between the data networks and not
dropping the stream in the process. This at least is the situation
for me with Sprint and AT&T using iPhone 5, EVO and Photon
smartphones. I keep my car phone locked on 3G only, as it has had
better coverage than the 4G network and results in far fewer dropouts
by not needing to switch back and forth.
mobile data industry makes a ton of money. Supply and demand has
certainly been a factor for their growth. To really get a better look
at the industry’s anticipated growth, take a look at CTIA’s
fact sheet, from which I come away with the idea that the industry will only
continue to grow and provide their customers what they desire.
the bottom line is that no single drive route test is a tell-all for
the technology. There are too many different factors that each user
will face in each location.
are known places where I always get dropouts when driving the many
miles to and from work each day here in Chicago, but there are some
that come and go, as a result of being down, out of bandwidth due to
congestion or a total lack of coverage. I can tell you too that there
are many places where the networks operate very poorly with data and
lacking in anything more than 3G, if they have any coverage at all.
If you live in Billings, Mont., you likely don’t have Sprint, since
they have only roaming coverage there. There are many places not yet
ready to handle this demand.
NPR Labs study seeks to find the optimum codec and bitrate for a
mobile stream. While they state they used multiple smartphones for
their test, it appears they only use one unnamed cellular provider.
Based on my experiences, the results are certain to vary greatly from
city to city, carrier to carrier, and device to device. I know the
technology has been good enough in Chicago for some time to be a
competitive distribution system; there are fewer dropouts in some
places with my cellular data coverage than many of the HD Radio
signals. I am sure the cellular companies will continue to improve
their data provisions, but listening to a stream may come at a hefty
cost as the demand for more of it continues to grow, unless the data
rates are kept as low as possible.
we’ve come full circle and I have just stated what I thought was
the obvious: The least amount of bandwidth we can get away with using
is beneficial for us all. The choice of codec thus follows the
constraints of bandwidth, with the tradeoff of sound quality for the
given bit reduction required. I’ve been using AAC+ for some years
now at 96 kbps, but I always have an ear listening for the next
generation of codec. Opus is certainly getting a lot of buzz, for
which I am just starting to test. OGG did well for its day, but AAC
is more for the purist. Opus seems to be the next real challenger at
the moment for low-bitrate codecs like AAC+. I’m sure we’ll all
be learning more about it and other codecs in the future. Suffice to
say, there is a definite need for continued development to get a
good-quality codec to work at the lowest rate. Is the cellular
industry ready for this kind of data demand? I’ll go out on a limb
and say no, not right now … But given the challenges, I bet they’ll
find a way to make it happen.
Clifton is chief engineer at Cumulus Radio Chicago. Comment on this
or any story to firstname.lastname@example.org.