applications. Today, this is no longer true. Today, GEO satellites offer high-quality, two-way transmission for certain applications. LEO technology has advanced to the point that it now offers low-latency, two-way communi- cations at broadband speeds, is relatively inexpensive, and as a conse- quence poses a clear threat to terrestrial services. On the other hand, the best way to eliminate an enemy is to make the enemy a friend. Many tra- ditional service providers have entered into alliances with satellite providers; consider the agreements that exist between DirecTV and SBC Corporation. By joining forces with satellite providers, service providers create a market block that will help them stave off the short-term incur- sion of cable. Between the minimal infrastructure required to receive satellite signals and the soon-to-be ubiquitous deployment of DSL over twisted pair, incumbent local telephone companies and their alliance partners are in a reasonably good position to counter the efforts of cable providers wishing to enter the local services marketplace. In the long term, however, wireless will win the access game. Other Wireless Access Solutions A number of wireless technologies have emerged in the last few years that are worth mentioning including 802.11, WiMAX, Ultra-Wideband, ZigBee, SF-OFCDM, Bluetooth, and the WAP. A Goat Trail Technology In keeping with the technologically schizophrenic nature of this book, we begin our discussion of Wi-Fi by talking about goat trails. 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 Go to any reasonably sized business park or college campus and you will see that the designers of the place have gone to great lengths to make the environment pleasing. They have tastefully positioned the buildings in such a way that they are optimally collocated, sometimes even exhibiti