 States kept its market unregulated for political, economic, and competitive reasons. Digital wireless technologies brought a higher quality of voice to roaming users. The result was that several competing second-generation technologies appeared in the United States, such as Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA), and even GSM, along with the older analog Advanced Mobile Phone System (AMPS) networks. This is why U.S. mobile carriers never attained the same deployment economies of scale of GSM as European carriers and as carriers on other continents where European manufacturers exported it. CDMA in its wideband varieties soon became accepted as the third-generation standard. It will be deployed in a couple of different standards in North America, Europe, and elsewhere, with the hope that some sort of compatibility of third-generation networks can be expected. Third-generation tech- nologies promise to further enrich the lives of users by enabling high-speed interconnectivity, among other things, that can transmit images, compressed video, high-quality audio, and data onto multi- media-enabled handsets. Microbrowsers are already available in handsets equipped with a liquid crys- tal display (LCD) screen. This screen enables the mobile browsing of Internet web pages through technologies such as the Wireless Application Protocol (WAP). The m-commerce area that is enabled by such an infrastructure looks extremely promising. 27. Walter J. Goralski, SONET (New York: Osborne McGraw-Hill, 2000). 28. Peter Tomsu and Christian Schmutzer, Next Generation Optical Networks: The Convergence of IP Intelligence and Optical Technologies (Upper-Saddle River, New Jersey: Prentice-Hall, 2002). 29. Uyless D. Black, Optical Networks: Third Generation Transport Systems (Upper-Saddle River, New Jersey: Prentice-Hall, 2002). Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to 