ls (very small service areas) for connectivity. To date, the most successful applications for Bluetooth are indeed cable replacement solutions on mobile phones, PCs (keyboards and mice), and headphones. The technol- ogy is also enjoying some success in the sensor and monitoring markets and is experiencing uptake in the manufacturing, security, and health- care sectors. The Wireless Future So what does the future wireless environment look like? Most likely, some form of industry consolidation for both economic and technology reasons is in order. Today there are two primary wireless camps in the United States: the GSM companies, including Cingular and T-Mobile; and the CDMA companies, including Verizon Wireless and Sprint PCS (at the time of this writing the two companies are rumored to be consid- ering a merger). The truth is that GSM's days as a widely deployed pro- tocol are probably somewhat numbered in the long term, even with the imminent arrival and implementation of GPRS (and possibly EDGE). The saving grace is UMTS; it will extend the life of this service for GSM's approximately 750 million worldwide users. CDMA, however, is rapidly becoming the preferred protocol for 3G implementations. North America, Russia, and China all have large CDMA networks, but GSM still has large numbers of subscribers glob- ally. In reality, the answer may not be an either/or question, but rather a dual-mode solution. One answer might be to offer CDMA as an overlay 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. Access Technologies Chapter 6 in GSM areas that have access to the appropriate spectrum. And of course, UMTS is the ultimate goal that will "harmonize" the two access options. One factor is that CDMA appears to be a more cost-effective solution than traditional GSM and its various evolutionary stages. Performance is another consideration: 1X offers 