In what experts claim is the biggest advance in broadcasting since the invention of the transistor, a recently approved communications industry standard will soon pave the way for digital AM radio.
This new wave of broadcasting is about to reach the marketplace with the recent adoption by the International Telecommunication Union (ITU) of a worldwide standard on digital sound broadcasting for long, medium and shortwave transmissions.
Based in Geneva, the ITU is the primary international body for fostering co-operative standards for telecommunications equipment and systems.
The approval of a worldwide standard should provide economies of scale in the production and deployment of transmitters and receivers with potentially lower costs to consumers, while giving broadcasters the flexibility to migrate to digital AM radio, according to market demand.
The ITU also noted that as the existing FM bands were nearly congested and AM bands were of poor quality, digital AM radio would offer substantial advantages to broadcasters seeking to bolster their market shares.
For consumers, the ITU's decision would mean additional sources of programmes at FM-like quality with low-cost, simple-to-use receivers.
Digital AM radio is expected to reach the mass market by 2003.
"It is a breath of fresh air" Peter Senger, chairman of Digital Radio Mondiale (DRM) said.
"This landmark decision will bring affordable digital quality sound and services to the world radio markets that will surpass listeners' expectations and will revive the broadcasting market in areas where development was stagnating."
DRM is an international consortium consisting of some of the largest international broadcasters, communications systems developers and electronics manufacturers, whose main aim is to formulate a non-proprietary, evolutionary and market-driven digital AM system design.
The consortium, along with digital radio and audio compression technology provider iBiquity Digital, has been active in the negotiations leading to the ITU standard, which includes technology proposals from both iBiquity and DRM.
According to the ITU, the changeover to the new digital AM radio system will be transparent because the same frequency bands based on the same channels will be used and the handsets will continue to be available in the same range of choices - fixed, portable and mobile radio.
What is expected to be noticeable, however, will be the improved quality in terms of digital AM's "crystal-clear reception" and the more diverse and rich programme content as a result of the increase in the number of broadcasters that can be accommodated on existing AM bands.
"This is the biggest advancement in broadcasting since the invention of the transistor," Mr Senger said.
Ibiquity president and chief executive Robert Struble agreed that the ITU's adoption of a digital AM broadcasting standard was just such a significant milestone.
"Digital broadcasting offers the potential for new and improved services to AM radio listeners," he said.
Digital AM's better audio quality and provision for value-added services, including data, text or still images, are expected to translate into increased audience interest and advertising revenue for broadcasters.
"This integration of audio and wireless data transmission will enable a variety of consumer applications, such as station and programme content, local traffic and weather information, news and much more," the ITU said.
Because the digital signal was more reliable and robust, it could be nearly interference-free, it added.
Digital AM receivers are supposed to tune to the best possible reception quality of a given station, based on the strength of the signal and the automatic frequency switching system in any of the long, medium and shortwave bands.
For broadcasters, the new technology means that they would be able to bring FM quality to AM bands at substantially lower costs because digital AM could accommodate existing frequency plans, the ITU said.
Digital AM is also supposed to be more spectrum-efficient, making it possible to reduce the power of radio transmitters by as much as 25 per cent while maintaining the same coverage area.
As such, broadcasters would be able to transmit their programmes in two languages, a plus in bilingual countries or in border zones between countries that used different languages, the ITU said.
For radio system manufacturers, digital AM is supposed to bring a second lease on life to older AM technologies with increased market potential for transmitters and receivers.
The new technology also made it possible to optimise the return on investment for dual technology components for low data rate systems applied to narrow-band transmission channels, the ITU said.
It also said digital AM's benefit for equipment and semiconductor manufacturers was clear: There were potentially some 2.5 billion radio receivers that would ultimately be candidates for replacement, some 700 million of which were for shortwave reception.
An estimated 1,000 transmitters worldwide are also due for replacement as the new digital AM broadcasting standard is adopted.
In the transition period, transmitters and receivers would handle both analogue and digital signals to enable broadcasters who had large operations in the AM band to opt for simulcasting as they continued to serve their customers while building a new market, the ITU said.
In vacant AM channels, broadcasters are supposed to be able to launch full digital AM as the receivers will recognise both analogue and digital signals.
Manufacturers were expected to provide the market with multistandard receivers to enable the simultaneous reception of analogue AM and FM and digital AM stations, the ITU said.
