levision, which debuted in the 1990s on some satellite and cable TV services). Over the next several years, digital radio will grow rapidly and will eventually replace today's AM-FM receivers. The worldwide digital radio market, both satellite and terrestrial, will grow to over 19 million unit shipments in 2007, according to statistics compiled by Scottsdale, Arizona-based In-Stat/MDR. The high-tech market research firm believes that new content-stations that only exist in digital-and data ser- Telecosmos: The Next Great Telecom Revolution, edited by John Edwards ISBN 0-471-65533-3 Copyright © 2005 by John Wiley & Sons, Inc. SOFTWARE-DEFINED RADIO vices will drive consumer demand for these radios. These factors are already at work in the digital satellite radio arena in the United States and the digital terrestrial market in the United Kingdom. "The conversion from analog radio to digital has been a long, slow process that will take many more years," says Michelle Abraham, a senior analyst with In-Stat/MDR. "When the first digital broadcasts became available in Europe, receivers were too expensive for the mass market. Over five years later, receiver prices have come down, but many countries are still trialing digital broadcasts, waiting for the regulatory frame- work to be in place and digital coverage to expand." Satellite radio has been successful in the United States, and other countries are hoping to duplicate that success. In South Korea and Japan, providers want to deliver not only audio streams but video streams as well. Several hundred million analog radios are sold worldwide each year, in the form of stereo receivers, CD boom boxes, portable devices, alarm clocks, and car stereo systems. Reductions in the cost of digital tuners will convert the more expen- sive of the analog radios to digital by the end of 2007. Even venerable U.S. AM broadcast radio, where the whole industry started some 80 years ago, is going digital. HD Radio broadcasting technology, devel- oped by Columbia, Maryland-based iBiquity, p