the harmonics created in cable networks just happen to fall within the range of frequencies used in avionics, and therefore have the potential to affect aviation communications and navigation. So when you see the cable truck that looks like a commercial fishing boat cruising the neighborhood with 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. First Things First First Things First all the antennas on top, they're looking for signal leakage from unauthorized taps. They will find them and they will come in and fix them, and you will get a bill for it. So if you want to add a connection in the house, call us. It's cheaper. That completes our introduction of common terms, with one exception: the Internet. The Internet: What Is It? The Internet is a vast network of networks, recognized as the fastest growing phenomenon in human history. In the words of Douglas Adams, author of A Hitchhiker's Guide to the Galaxy, the Internet is "Big. Really big. Vastly, hugely, mind-bogglingly big." And, it is getting bigger: The Internet doubles in size roughly every year, and that growth rate is expected to continue. Not only is the Internet global in physical scope, it is universally rec- ognized. Everybody knows about the Internet. In 1993, it came booming into the public consciousness, put down roots, spread like a biological virus, and flourished. Like other famous public figures, it has been on the cover of every major magazine in the world, has been the star of books, articles, TV shows, and movies, and has been praised as the most signif- icant social force in centuries and debased as the source of a plethora of worldwide ills. Yet, for all this fame and notoriety, little is actually known about the Internet itself-at least, its private side. It is known to be a vast network of interconnected networks, with new appendages connect- ing approximately every