Shortwave radio, with its worldwide reach, has long been an effective tool at getting information around the world, especially to poorer countries. But, due to the cost of broadcasting, many international shortwave broadcasters, like our own Radio Canada International, have been shutting down or cutting back their services.
Radio is expensive. With shortwave, which broadcasts in AM mode, a signal must be quite powerful to get around the world. While AM is great at travelling long distances, it's also prone to fade-outs, loss of audio quality and interference.
Digital Radio Mondiale (DRM), a non-profit organization, has developed a set of digital broadcasting technologies designed to lower the cost of broadcasting across the shortwave (SW), traditional AM radio (MW) and long-wave (LW) bands. It works by allowing more stations to be broadcast by reducing the bandwidth needed for a station by using computer processing. Since broadcasting radio is expensive and computer processing is becoming cheaper, it makes sense to have computers take the brunt of processing the signal for broadcasting.
In addition, the technology allows for better quality sound, providing protection against fading and interference from other stations and atmospheric storms.
By using a digital encoding, the radio signal is compressed, dropping down broadcasting power requirements. It also allows stations to use already built analog antennas in coordination with the new technology, further dropping the cost. A great deal of the technology, including the technical standards, is free, which removes even more cost.
DRM has been tested with numerous overseas SW broadcasters such as the BBC World Service, Radio Exterior de Espana (Spain), Radio New Zealand International and Radio Romania, among others. All India Radio, the international and domestic radio service of India, has led the charge to adopt DRM
All India Radio has already changed 35 high power MW stations and 3 SW transmitters to DRM technology, which reaches over 900 million people in India. Other countries taking an interest in DRM include Pakistan, China, Indonesia, Russia and Brazil.
In addition to AM radio broadcasting, DRM has developed a similar process for FM stations, called DRM+. Unlike AM transmissions, FM radio is typically used for short range broadcasting with a high audio quality suitable for music broadcasts. DRM+ technology will help FM broadcasting take up less space on the FM band, allowing for more stations to be broadcast.
With DRM helping bringing the cost of broadcasting down, we could see a resurgence in AM radio, both with MW and SW stations. The return of more international public broadcasting would be a huge boon to poorer countries in the third world and their ability to access news, and to repressive
