Philippe Gandy and Jean-Michel Bouffard at work in the Digital Audio Broadcasting (DAB) Lab at the Communications Research Centre Canada.

To most of us, radio consists of an AM/FM dial and a number of frequencies, or “stations,” that may offer up a favorite tune or a news update. Behind the scenes, however, the dynamic world of radio is rapidly growing and changing as new technologies emerge.

At the Communications Research Centre Canada (CRC), researchers have been studying Digital Audio Broadcasting (DAB) since the late 80s. DAB radio works by converting the music or speech from an analog signal into digital code. This vastly reduces the potential for the broadcast service or content to be corrupted during transmission by reflections, interference and other problems that can degrade the quality of reception. Unlike AM and FM radio, DAB was designed to be received by mobile receivers. For this reason, DAB needs to occupy a larger bandwidth (7.5 times larger than FM radio), which makes the transmitted signal more robust.

From the perspective of the DAB listener, larger bandwidth simply means that the problems of “hiss and crackle” (caused by multipath interference) are eliminated, resulting in a better overall sound. Another user advantage is that DAB digital radio sets come equipped with a small screen that carries information about the program, such as the song title being played, the artist, up-to-the-minute sports results and more.

Today, CRC is involved in the development of an improved version of the original DAB system. This will make it even more spectrum-efficient and allow for the introduction of multimedia services without sacrificing bandwidth for audio services. In the future, DAB may include services such as mobile television, a broadcast Web site (BWS), an electronic program guide (EPG) and visual radio, which would add a synchronized visual component, such as a slide show, to an audio program.

CRC is also working with CBC to set up a Mobile Multimedia Broadcasting (MMB) system in Montreal. MMB is a generic name for all the DAB-based multimedia technologies, which aim at providing TV and multimedia content to mobile and portable receivers. It is expected that these technologies will be introduced primarily on cell phones and PDAs, with multimedia services provided by radio broadcasters who hold the broadcast infrastructure and the spectrum. The experimental system in Montreal will allow comparative tests and demos of the different technologies, which will assist in the development of engineering rules for the planning of these services.

Phillippe Gandy works in a CRC test vehicle, equipped with a complex antenna system that allows the reception of DAB at vehicle speeds higher than what the current standard allows.

Researchers at CRC are also watching a competing radio technology called In Band on Channel (IBOC), which has been developed and deployed throughout the U.S. With an aim to understand the impact of IBOC should it be adopted by Canadian broadcasters, CRC staff are studying factors such as the quality of the digital coverage and its robustness for mobile and indoor reception. They will also look at interference to other FM stations caused by the addition of this digital signal, particularly when all the stations in a very spectrally congested area are turning to digital IBOC. Their studies are made possible by CRC’s unique prediction software, called CRC-COVLAB.

In addition to the DAB and IBOC, a number of other mainstream radio technologies are competing for air time. Satellite radio services, offered by companies such as XM Radio and SIRIUS, allow listeners to tune in to commercial-free channels based on a user subscription fee. The Internet is also a contender in its own right, allowing for easy access to music in a downloadable MP3 format.

With so many changes on the technological landscape, broadcasters can’t help but be nervous about the future. It’s a crucial time for the broadcasting industry to stay in touch with emerging radio technologies, and to reconsider the role of traditional radio amidst the many new players in the arena. At CRC, researchers play the role of looking beyond the technology horizon, to advise Canadian broadcasters on new trends and changes taking place around the world. CRC is plugged into various international radio standards committees, and reports back to Canada’s broadcasting industry on the key findings.

While the question still remains over which emerging radio technologies will stand the test of time, it’s clear that radio as it once was will never be the same again.

*For more information about CRC’s work with emerging radio technologies, please contact René Voyer at rene.voyer@crc.gc.ca.