romises to transform the lis- tening experience of the 96 percent of Americans who listen to AM and FM radio on a weekly basis. The commercial launch of HD Radio will enable the nation's 12,000 radio stations to begin the move from analog broadcasting to higher-quality digital broadcasting, bringing improved audio quality and an array of wireless data services to consumers. HD Radio technology has been tested under experimental licenses across the country, including KLUC-FM and KSFN-AM in Las Vegas, KDFC-FM and KSFN-AM in San Francisco, WILC-AM in Washington DC, WGRV-FM and WWJ-AM in Detroit, and WNEW-FM in New York. 6.2 SOFTWARE-DEFINED RADIO Standards, such as GSM, GSM, and CDMA, define the way mobile phones are designed and used. But what if a mobile phone or radio could be instantly adapted to accommodate any standard, simply by loading in various free pro- grams? Such a product-a software-defined radio (SDR)-would not only lead to easy, pain-free compatibility but would revolutionize the wireless telecom industry. Proponents claim that SDR technology represents the future of wireless communications. As a result, the days of custom ASICs and radio hardware may be numbered, ushering in a new era where upgrades and reconfigurations of wireless equipment require only a new software load. SDR has the poten- tial to open new business opportunities for carriers and cellular providers as well as the entire handset market. However, none of these opportunities is expected to happen overnight. Several key development milestones, including SOMETHING IN THE AIR-RADIO AND LOCATION TECHNOLOGIES the creation of industry-wide standards, must be reached to move SDR tech- nologies into the mainstream market. SDR is already used in some base station products, as well as in military and aerospace equipment. Although the technology has yet to make major inroads into any consumer-oriented markets, the SDR Forum trade group projects that by 2005 SDR will have been adopted by many telecom vendors as their core platform. Another pote