0 feet, and while the 11 Mbps is more typically 7 Mbps and the 54 more like 30, that's still a healthy chunk of access bandwidth. There are other technologies on the horizon, however, that may prove to be more desirable than Wi-Fi in the medium- to long-term future for certain applications. They include WiMAX, Ultra-Wideband, ZigBee, SF-OFCDM, and Bluetooth. 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 An Aside: Mobility vs. Ubiquity As a telecom industry analyst and author of numerous books about the business and technology sides of the telecom marketplace, I tend to focus on the words used by the people and companies that comprise the indus- try, because the careless use of those words often leads to misinterpreta- tion, which in turn leads to inappropriate investment and infrastructure decisions. To that end, I realized recently that two important words in our technology lexicon are used synonymously. The words "mobility" and "ubiquity" are not synonyms. However, applications, network designs, investment decisions, strategic planning efforts, and end-user device engineering are being done as if they were one and the same. At worst, this will lead to another spate of ill-placed investments and the requisite marketplace blowback; at best it will lead to confusion and the resulting slowdown of effective deployment. Hopefully, the former won't occur; the latter already has. So before this gets too far down a dead-end road, let me clarify the difference between the two, beginning with definitions. According to the American Heritage Dictionary, "mobility" means "the quality or state of being mobile," while "ubiquity" is defined as "existence or apparent existence everywhere at the same time." From a communi- cations perspective, mobility means being able to move freely while staying connected, as when engaging i