BKHWWLWK.RVW 20011017 "How Wireless Works", Preston Gralla, 2002, 0-7897-2487-1, U$29.99/C$44.95/UK#21.99 %A Preston Gralla preston@gralla.com %C 201 W. 103rd Street, Indianapolis, IN 46290 %D 2002 %G 0-7897-2487-1 %I Macmillan Computer Publishing (MCP) %O U$29.99/C$44.95/UK#21.99 800-858-7674 info@mcp.com %P 232 p. %T "How Wireless Works" Albert Einstein was once asked to explain radio. His famous response was that one should consider a cat long enough to stretch across the United States. Pull the cat's tail in New York, and it meows in Los Angeles. Radio, said Al, is just the same--except that there is no cat. What Einstein did facetiously, Gralla seems to be trying to do in earnest. This pictorial non-explanation provides the reader with a lot of interesting information and trivia--about everything except the central topic. There is some very good material. The basic explanations of modulation and the electromagnetic spectrum are excellent. But they are also old news: well known concepts that aren't new fields of technology. When the book moves into applications it also starts to engage in hand-waving. Even basic broadcast radio and television is only covered at the level of "the information goes in here and it comes out there." Once the topic moves to cellular systems and wireless networks the terms are all there (handoff, CDMA, WML, Bluetooth, GSM, WAP), but the reason given for how it works is merely that it does. Some of the material, simplistic as it is, contradicts itself. On page 91 we are told that all digital cellular systems use only one frequency for both transmission and control, while the very next sentence says that digital cellular phones can do so if necessary. Other parts are unintentionally ironic, such as the page that shows a "hacker" being stopped by a firewall on a wireless network, when the security leakage that wireless networks provide has been amply documented. (In the section on security these problems are virtually ignored: the only items of concern are "wireless viruses" and cloned cell phones.) A little effort put into bringing the contents of this colourful book up to the same level as the introductory material would make it a more useful tutorial for non-specialists. It is rather frustrating to read these pages and note that very brief additions could have immensely enhanced them. As it stands, the first chapters do explain the concepts behind basic radio transmissions and data modulation. The bulk of the work is flashy, but pointless. copyright Robert M. Slade, 2001 BKHWWLWK.RVW 20011017