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The
Digital Media Manifesto
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Source
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Ernst
F. Schroeder
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Title
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Use case
no. 07: Radio |
No.
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030828schroeder01
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1.
Introduction
This
contribution uses the methodology proposed in 030701chariglione01 for the
specific use case “Radio”, i.e. terrestrial broadcasting of audio signals.
The
facts are taken from my own memory and experience, also some input has been
taken from use case 6 "terrestrial broadcasting" by Chieteuk Ahn.
2.
Description of the traditional use case
2.1
Functions of traditional "Radio"
Radio
is a prototypical case of communication with one-to-many directional characteristic.
The communication channel uses signals audible by the end user (audio, sound)
and electromagnetic waves as (wireless) carrier.
At
least three different types of communication are supported:
This seems to have started the whole
"Radio" story, when around 1920 existing equipment for point-to point voice
communication was tried for transmission of music. The acceptance was tremendous.
Radio not only embraced existing entertainment genres like opera, plays, and
music in general, but also spawned a whole new range of entertainment arts
like radio dramas and plays.
It has very soon been detected that
Radio is in fact a very fast medium for the dissemination of information like
news, stock market reports or weather forecasts, much faster than printed
papers. People had to learn though that the information conveyed by this new
medium could have been manipulated, like in all other media known before.
The War of the Worlds by Orson Welles was just a joke compared to what
governments were able to do to their citizens.
Also, in the very first beginning,
it was detected that advertisements by radio really worked. They are an integral
part of Radio ever since.
2.2 Traditional
value chain players
The traditional
value chain players are:
· Broadcasters:
They
provide the basic infrastructure for wireless transmission of audio signals.
Their size ranges from a team of few running everything to nation-wide chains
with thousands of employees. Some broadcasters cover several pieces of the
value chain.
·
Program creators:
They
assemble pieces of content into program streams with a certain "style" to
make the program easily distinguishable and to bind end customers.
·
Content creators/owners:
They
provide content to program creators and expect remuneration. They
are extremely interested in feedback on the type and amount of actually broadcasted
content.
· Advertisers:
They provide material to broadcasters/program
creators and buy broadcasting time. They are extremely interested in feedback
on the size and structure of actual audience.
· End
users:
They
consume "Radio" for entertainment and information, with a broad range of needs
and expectations.
· Equipment
manufacturers
They
are divided into manufacturers of professional equipment (transmitters, studio
devices) and manufacturers of consumer devices (home and car radios, stationary
and portable, mains and battery operated).
· Authorities
To avoid interference and to ensure
a minimum of interoperability, regulating authorities have been set up as
soon as “Radio” changed from experimental stage to a real service.
In some countries a monthly fee has to be paid by end users for the permission to participate in the radio service.
· Monitoring services
Content owners, advertisers and
authorities are interested in reliable figures on actual transmitted program
content and on adherence to technical specifications.
2.3 Technologies
used in the traditional use case
Radio
uses traditional analog wireless technologies like single fixed RF carriers
in the range from 150 kHz to 110 MHz, either modulated in amplitude or frequency.
In the course of roughly 80 years some incremental technology improvements
and a few disruptive changes have been made, like e.g. introduction of VHF-FM,
2-channel stereo and traffic messages.
The
choice of frequency range and power allows to select the area of coverage
for the radio broadcast service. This can range from covering an urban neighborhood
up to worldwide coverage.
Depending
on the used carrier frequency ranges and the intended coverage, transmitters
use powers from some 100 Watts up to 500 k Watts or more. The possibility
of mutual interference calls for careful coordination of location, frequency
and power, from a local level within a country up to a worldwide level.
Receiver
technology can be extremely simple, starting with the completely passive galena
crystal receiver, up to moderately elaborate, using superheterodyne circuits
with 5..10 active elements (tubes / transistors).
The
received audio quality is limited, not generally but more by the choice of
some parameters like channel spacing and type and degree of modulation. Audio
bandwidth ranges from about 50 Hz to 5 kHz (MW-AM) or 15 kHz (VHF-FM), the
attainable dynamic range is in the order of 50 dB (VHF-FM).
Although
not strictly "terrestrial", it should be mentioned that some analog radio
services exist over satellite links. They typically use spare spectrum on
TV satellite transponders. One of the advantages is the large coverage with
a quality level similar to VHF-FM.
2.4 Legislative
framework of the traditional use case
·
Public/National
authorities set legislative environment on broadcasting
·
Public/National
authorities regulate spectrum use by Radio operations
·
Where
applicable, public/national authorities enforce end users to pay for permission
to receive the radio service
·
Rating
and censorship can be imposed by public/national authorities
2.5 Business
model of the traditional use case
The
very nature of "broadcasting" in analog technology (i.e. without any form
of access control) implies that the end user does not directly contribute
to funding the radio service. He does so in some countries though, where a
monthly fee has to be paid to obtain permission to receive the radio service.
If
not partially or totally owned, controlled and paid for by public or national
authorities, most radio operations are since long and up till today paid for
by advertisements in a broad sense. This covers
"classic"
advertisements, local
or nation-wide
promotion
for music distribution
most of today's radio programming
is fuelled and directly or indirectly funded by the big music labels. Radio
is more and more seen as a promotion vehicle for new hit records.
Talking
end users into calling the broadcast station via special rate telephone numbers
can generate a further revenue stream. Such practices seem to develop.
3.
Description of the digital use case
3.1 Functions
of the digital use case
No
change from the traditional case.
3.2 Value
chain players in the digital use case
No
change from the traditional case.
3.3 Technologies
used in the digital use case
·
Digital
modulation and demodulation with application of error-correcting encoding.
Such digital
modulation (e.g. PSK, 64QAM, COFDM) makes it possible to transmit about 256
kbit/s within a typical VHF-FM channel (300 kHz BW) and about 48 kbit/s in
a typical MW/SW-AM channel (9..10 kHz BW). Some modulations like COFDM allow
for mobile reception and single-frequency networks. Some technologies like
IBOC (in-band-on-channel) are designed to allow transmitting digital signals
within the same channel assigned for analog AM/FM modulation, thereby solving
the problem of additional spectrum need.
· The
attainable net data rates are not large enough to convey typical CD-like audio
signals. Data reduction (compression) algorithms like the ones developed by
the ISO/IEC MPEG group have solved this problem not only for RF transmission
but also for in-house distribution and archiving.
· Inclusion
of additional data
Additional data like e.g. traffic
message control have already been used in traditional analog FM radio. Digital
transmission systems allow for much higher additional data rates and more
diverse applications (up to sending video over radio channels).
3.4 Cost/benefits
for value chain players
|
Value
chain players |
Cost |
Benefits |
|
Broadcasters
|
need
new equipment, especially new & expensive transmitters |
can
possibly adjust coverage, chance of new frequency allocation, audio
data reduction allows for decreased storage/archiving requirements, digital
technologies enable automated program control, leading to cost reduction |
|
Program
creators |
new
equipment needed |
easier
data handling, access, storage |
|
content
creators/owners |
initially
increased production cost |
easier
data manipulation, access, storage, rights
management becomes possible |
|
Advertisers
|
initially
increased production cost |
easier
interworking with programmers, |
|
End
users |
need
new equipment |
received
audio quality can be increased (but only marginally as compared to
VHF-FM), more
data information possible |
|
equipment
manufacturers |
cost
for new developments |
new
markets |
|
Authorities |
regulation
needed for new services, |
chance
to sell/auction RF spectrum |
|
Monitoring
services |
|
new
markets, as reliability of feedback data can strongly increase |
3.5 Legislative
framework of the digital use case
Currently
no significant changes are under way.
3.6 Business
model of the digital use case
Practically
no changes. Where monthly fees are imposed, these can be increased by authorities
and directed to supplement installation of new digital broadcasting networks.
3.7 Difficulties
of current deployments
Two
different developments can be seen:
First,
the adoption of digital technology within the radio production chain is nearly
total. The benefits are clear and where at all possible, cost savings have
been realized by going "digital".
Secondly,
the adoption of digital technologies in the final link to the customer does
nearly not exist. The EU-147 DAB system has been introduced in several European
countries (GB, F, D, …); transmitters are working and receiving equipment
does exist, but spread is slow. The DRM (Digital Radio Mondiale) system for
MW/SW frequencies is also technically ready and has been officially started
in June 2003, but deployment did not yet really take off.
It
is interesting to note, that the radio service via TV satellite transponders
has adopted digital technology easily and nearly without friction (see e.g.
ASTRA Digital Radio).
4.
Hurdles
We
have the classic transitional problem with an existing service: chicken-and-egg
for new devices, mixed with tons of legacy devices.
The
following can be considered as hurdles of primary importance:
·
Lack
of perceived service improvement for the end user:
The
perceived quality of DAB with respect to existing VHF-FM is not at all drastically
better. There is a large base of well-operating legacy equipment and nobody
dares to make this obsolete.
Today
an analog VHF-FM receiver can have the size of a credit card with negligible
power consumption. Even with Moore's law in mind, it will take some time until
DAB receivers can be had with such size and power consumption.
Additional
digital services (like traffic messages), where at all existing, are not better
than their analog counterparts. In fact, in some areas traffic monitoring
services have been taken over by TV broadcasters or by more reliable pay services.
·
Lack
of profitable business models for broadcasters
In
spite of large initial investments for new transmitting equipment, there will
be no new revenues for broadcasters. There may be a small chance to extend
or adjust area coverage in the course of a special transition scenario, but
chances are that area coverage may be even more limited, as with digital technologies
coverage is easier to confine to a given area.
·
Scarcity
of RF spectrum
The fierce competition for and the
apparent value of RF spectrum demand a transition scenario that keeps "Radio"
within the existing allocated spectrum.
A few spots (like TV Channel 12 or L-band frequencies) have been identified
in EU for permanent or interim use of DAB radio. It remains to be seen, whether
the "switch off FM in ten years" goal can be reached.
5.
Relations with other use cases
Terrestrial
broadcasting
Home
user
6.
References
none