on the low end of where 3G hopes to go, but they can move up. In fact, for cdma2000, CDG has defined a migration path that we describe in Sec. 10.2. 9.2.3.3 Unification and harmonization. The effort to create a unified worldwide standard largely failed. There also was talk of harmonizing existing standards, but the competition between cdma2000 and W-CDMA can scarcely be called harmonious. As the attempt to develop a truly global standard unfolded, the stakes were simply too high. Companies are already entrenched in different national markets, have hun- dreds of millions of customers, and have invested billions in the ability to manufacture current technologies. Understandably, each company wanted to continue to benefit from the manufacturing base it had developed. Long-standing rivalries and resentment over having to pay license fees (particularly to Qualcomm) did not make the situation any easier. Even if all the companies had agreed on a technology, there was no way to sort out the bandwidth problem. Some nations follow the U.S. FCC in allocating frequency use, and other nations follow the European model. As a result, there is no single frequency available for terrestrial cellular communications worldwide. The ITU simply did not have enough influence with national governments around the world to sponsor a new, standardized allocation system. In addition, although CDMA has distinct technical advantages, it is only used by about 15 percent of the world's cellular telephone users. Even if CDMA wins out in the long run, it will take a good deal of time. Instead of insisting on a single world standard, the committee approved five differ- ent standards, saying that they met the overall standard of 3G communications. The Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. General Cellular Standards General Cellular Standards overall standard was IMT-