Some digital technologies have had it easy. CD efficiently established itself as the dominant form of music storage, while DVD rocketed to the top of the digital success chart.

Digital broadcasting however, has not had as much success as digital storage. The problems faced by digital TV have been well documented, and digital radio has yet to worm itself into the mainstream, having been plagued by problems of signal strength and consumer understanding.

Some companies have products ready to roll, but are still reluctant to put them on the shelves for fear of reprisals from consumers unable to get the units to do their stuff. In some cases the problem is so acute, that the same radio may not necessarily work in different corners of the same room.

At the same time digital radio is now having to watch its back as potentially rival technologies are starting to sneak onto the scene, in the form of Digital Radio Mondiale (DRM). The on-air system DRM has been endorsed by the International Electrotechnical Committee (IEC), which published its DRM Publicly Available Specification (PAS 62272-1). DRM is the world's only non-proprietary, digital AM system for short-wave, medium-wave and long-wave with the ability to use existing frequencies and bandwidth across the globe. The IEC approval, together with DRM's existing certifications by the International Telecommunications Union (ITU) and the European Telecommunications Standards Institute (ETSI), puts DRM a step closer to its 2003 launch.

Boasting a near FM sound quality, DRM aims to revitalise the AM broadcasting bands below 30 MHz in markets worldwide.

FM sound broadcasting is gradually moving to a DAB standard, but coverage on FM 88-108 MHz (VHF) is limited. For many national and international broadcasters, the advantages of a complementary digital broadcast system below 30 MHz are becoming clear. However, the limited fidelity of existing AM services is causing listeners to search for other alternatives.

Implementation of digital radio in today's AM bands (i.e. long, medium and shortwave) will enable operators to provide services which will be successful with both existing and future high-quality services operating on other parts of the dial.

"Digital radio mondiale is something that's gaining momentum," says Lesley Burrage, managing director of Roberts Radio and vocal supporter of DAB, and points out that it has been a focal point of many conferences in the past few months.