our economy to outsource communications and information technology infrastruc- ture will support more rapid growth in this market. In order to compete in a less reg- ulated, more competitive market, companies want to own less and less equipment, and wireless service providers could get extra income from existing infrastructure by pro- viding these services. Lastly, we should expect the unexpected. Both crises and innovations drive adoption of new technology. The Candlestick Park earthquake in 1991 increased telecommuting in northern California, and the World Trade Center tragedy of September 11, 2001, which overwhelmed both the PSTN and the cellular network, triggered a boost in satel- lite phone sales. On a more positive note, very few people foresaw how the development of the World Wide Web standard would cause the Internet to grow so rapidly outside the ivory tower to transform our economy. Doubtless similar innovations will create completely unexpected uses for wireless data technology. 3.2.3 Terminals without a human interface For people unfamiliar with the idea of automated devices communicating with each other, the idea of wireless communications without people may seem strange and unre- alistic. However, such communications have been around for decades and are growing Superscript(11)Some data services, including satellite and cable modem, have different throughput in differ- ent directions. 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. The User Terminal The User Terminal rapidly. For decades, computer systems have been designed that automatically call in to send or receive data, to report a malfunction, and even to be repaired or upgraded remotely. This usually takes place over a landline or, these days, the Internet, but it cer- tainly can occur over a wireless network as well. And the technology is already spread- ing from comput