The Digital Media Manifesto



Ernst F. Schroeder


Use case no. 07: Radio



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:

· Entertainment

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.

· Information distribution

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.

· Advertisements

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

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




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


initially increased production cost

easier interworking with programmers,
reliability of commercial feedback response can increase

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


regulation needed for new services,
transition scenarios need to be developed

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

6. References