© 2002, 2003 by Jeff Duntemann. All Rights Reserved. Linking encouraged! Feel free to quote, as long as the original wording is not changed. Send all corrections, suggestions, etc. to the email below, which is a bitmap to defeat the spambots, sorry:


Wardriving FAQ
Wi-Fi Security FAQ


Tetra Brik Antennas

Wi-Fi Encyclopedia:

Reference Design


It's been a busy and difficult year so far; Carol and I moved to Colorado Springs in April and have been working hard on getting a new house built ever since. My workshop has been in boxes since this past March, and therefore it's been very difficult for me to whip up new Wi-Fi gadgetry, as much as I want to. I want to experiment with saucer sleds as parabolic reflectors, but I have not lived in a climate that has winter since 1986. Once I score one I'll see if I can put something together with the hand tools I have available to me in our (rented) garage.

Speaking of my move to Colorado Springs, if you're a Springs-area Wi-Fi enthusiast and want to hang out with others of our type, I'm putting a group together. Email me and I'll let you know what we're up to. We hope to do an antenna shootout at some point, along with compatibility testing of gear from different manufacturers, and so on. One way to coordinate this is through Meetup. Join the Wi-Fi section for Colorado Springs, and if we get enough people to sign up (it's free) they'll coordinate the meetings. We do this here for Delphi, and it works fantastically well.

And if you're not in Colorado Springs, consider joining the Wi-Fi Meetup group in your area. There's safety (and shared expertise) in numbers.

If You Haven't Seen the Book Yet...

This is the support site for my newest book: Jeff Duntemann's Drive-By Wi-Fi Guide. The book was published March 1, 2003 by Paraglyph Press, the heir apparent of Coriolis Group Books, which was shut down March 31, 2002. The book is a slightly lighthearted treatment of 802.11 wireless networking, with an emphasis on the 802.11b standard. I wrote it for home office and small office users, rather than corporate IT types.

You can buy it on Amazon and Barnes & Noble Online, and in certain bookstores. Alas, it won't be at every bricks'n'mortar bookstore, and if you look for it at Borders or B&N and don't see it, bitch at them! They take every damfool worthless book from the big publishers, but they won't take more than a handful of books from small publishers, even when the author (like me) has sold books by the hundreds of thousands over an almost twenty-year period.

I get chewed out by the bookstore people for putting links to online retailers in my Web presence, but if they won't put a copy in every bookstore, what am I supposed to do?

802.11 Planet
Sifry's Alerts Wardrive.net Links

New and Notable Since the Book Was Published

FireWire with No Wire: The IEEE has convened a task group to implement a UWB (ultrawideband) wireless physical layer for the IEEE 1394 protocol, which most people know as FireWire. The wireless standard they're considering is 802.15.3, which is extremely fast (up to 400 Mbps is possible) but fairly short range. 802.15.3 is really a super-duper Bluetooth, intended for connecting gadgets within a single home (and ideally, a single room) rather than beyond the confines of a residence or throughout an office complex. A PowerPoint slide show on the topic is here. They call these things Wireless Personal Area Networks (WPANs), and I'm still a little skeptical (I don't do Bluetooth) but I am willing to be convinced.

The Atheros tri-standard chipset (that is, their chipset that supports all three standards a, b, & g) apparently fixes the problem (which I described in detail in the book) of 802.11a systems having very short range at high bitrates compared to 802.11b. New tests published on the Web by SmallNetBuilder guru Tim Higgins show that throughput stays higher farther from the AP. Tim has no reason to lie to us (he's as independent as they come) so my recommendation becomes: Hold out for tri-standard. I'm working on a short Web-based paper (watch for a link to your upper left) explaining in more detail. Atheros rocks!

Cisco is buying Linksys! A cool $500M will change hands in one form or another, but as best we can tell so far, Cisco will not be merging technologies much, and Linksys will continue to do what it's been doing these past several years. (But don't they always say that about an anticipated merger?) As usual, only time will tell.

Linksys is now selling a PC card capable of 802.11a, 802.11b, and (its interpretation of) the 802.11g draft standard. Three at once—and for $99! What amazes me about the WPC55AG is less the inclusion of g-functionality, which is dicey in any event, but the price point. For a hundred bucks you get a, b, and (maybe) g, when a alone (as the Linksys WPC54A) is still selling for $150 and up. Assuming this thing works well in 802.11a networks (I haven't tested it yet) you have to wonder why anyone would buy a dedicated 802.11a product anymore.

A start-up called Vivato has announced an interesting technology that greatly expands the range of Wi-Fi hotspots. Details are still a little sparse, but the gist of what they're doing is creating a system using a steerable array of many small Wi-Fi gain antennas that can literally follow an individual user as that user walks around within range of the array. The idea is to cover, from a single central antenna site, an area (like a city park or college campus) much larger than a single Wi-Fi hotspot could be. Theoretically, Vivato's technology can reach across a couple of miles, but it still has to be good line of sight, and just keeping unobstructed line of sight across a couple of miles is a challenge anywhere there are trees or buildings. (Nebraska, anyone?) This one's worth watching, and I'll speak of it more once I get a better sense for how it works.

I've discovered a new kind of can for cantennas: The cans that fancy-schmancy booze bottles are packed in. They are almost precisely the right inside diameter (3 5/8") and have no corrugations to scatter your signal and reduce the gain. (Peel the label from almost any sizeable tin can, like those containing tomato juice or spaghetti sauce, and you'll see what I mean about the corrugations.)

The can I have once contained a bottle of Malibu coconut-flavored rum, but I've seen similar cans for high-end whisky and other things. The gain is higher than my Tin Can Bandwidth Expander (see Chapter 15) but the beam width is also much narrower, and I think this is an antenna for fixed-point applications like bridging networks between houses.

I've created a pistol-grip handle for the antenna, and have done some limited warscanning with it from up on the roof, but it looks so much like some kind of weird weapon I'm afraid to go out in public with it!


Book Errata

One problem with errata for the book is that the Wi-Fi field is moving very quickly. What I knew in the fall of 2002 may well have been superceded by events in early 2003. This is an occupational hazard in the technology press, and the primary reason I'll be supporting this Web site.

Pages 169 and 170. The figure captions say, "Photo coutesy of Maxrad." Not true—I took these photos, but a helpful copy editor assumed that all antenna photos were from antenna vendors because many were. Ditto the photo on page 176—that's another of mine. Ditto page 203. Even though Linksys appliances stack, I doubt they'd post photos because of the obvious resemblance to—well, if you have the book you know what it bears a resemblance to.

Page 46, last paragraph. "Terminal Control Protocol" should be "Transmission Control Protocol." Many years ago, in my first programming job, I made use of an in-house mainframe computer system incorporating something called the Terminal Control Protocol. So while ripping along writing Chapter 3, I slipped back into old habits, and wrote "terminal" instead of "transmission." Many thanks to reader Robert Gelleni for spotting this one!

This isn't precisely a mistake, but it might confuse you: In the book's text I talk incessantly about Scottsdale, Arizona...and then in the author bio it says I live in Colorado Springs! Wassup? Well, shortly after finishing the book, Carol and I decided to move. Yes, I know I say that "I don't do winter" on page 351, but that was then, and this is now. You can razz me about it if you want; I'm sure I deserve it, and I'll take it gracefully.

Joltage, which I described in some detail in Chapter 10, has gone out of business. They barely lasted a year, sigh. Here's the news.com announcement from February 28, 2003. Other hotspot aggregators will appear to take their place. It's a lousy time to be implementing capital-intensive startups, and the important question is what the industry will learn from their failure.