excerpts from the wireless networking starter...

Excerpts from The Wireless Networking Starter Kit

Thanks for your interest in this set of excerpts from the book The Wireless Networking Starter Kit, written by Adam Engst and Glenn Fleishman. You can Networking Starter Kit, written by Adam Engst and Glenn Fleishman. You can Networking Starter Kitvisit the Web site for the book at www.wireless-starter-kit.com. It is available from all booksellers, including Amazon.com.

Why Wireless? (pp. 1-19)

Wireless Network Adapters (pp. 61-64)

Confi guring Windows XP Client (pp. 87-89)

Entering WEP keys in Mac OS X (p. 95)

Bridging Wireless Networks (pp. 152-156)

Preventing Access to Your Network (pp. 169-174)

Networks on the Road (pp. 200-212)

Antenna Types (pp. 235-240)

Ultra Wideband (pp. 299-300)

The full table of contents and index are available from our Web site.

http://wireless-starter-kit.com/

http://buybox.amazon.com/exec/obidos/redirect?tag=thewirelessne-20&link_code=xsc&creative=23424&camp=2025&path=/dt/assoc/tg/aa/xml/assoc/-/0321174089/thewirelessne-20/ref=ac_bb1_,_amazon

The practical guide to Wi-Fi networks for Windows and MacintoshStarter Kit

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By Adam Engst andGlenn Fleishman

Peachpit Press

The Wireless Networking Starter KitThe practical guide to Wi-Fi networks for Windows and MacintoshBy Adam Engst and Glenn Fleishman

Peachpit Press1249 Eighth StreetBerkeley, CA 94710510/524-2178800/283-9444510/524-2221 (fax)

Find us on the World Wide Web at: www.peachpit.comFind the book’s Web site at: www.wireless-starter-kit.comTo report errors, please send a note to [email protected] Press is a division of Pearson Education

Copyright © 2003 by Adam Engst and Glenn Fleishman

Editor: Nancy DavisProduction Coordinator: Lisa BraziealCopyeditor: Tonya EngstIndexer: Caroline ParksCover illustration and design: Jeff TolbertInterior illustrations: Jeff TolbertInterior design: David Blatner and Jeff Tolbert

Notice of RightsAll rights reserved. No part of this book may be reproduced or transmitted in any form by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. For information on getting permission for reprints and excerpts, contact [email protected].

Notice of LiabilityThe information in this book is distributed on an “As Is” basis, without warranty. While every precaution has been taken in the preparation of the book, neither the author nor Peachpit Press, shall have any liability to any person or entity with respect to any loss or damage caused or alleged to be caused directly or indirectly by the instructions contained in this book or by the computer software and hardware products described in it.

TrademarksAll trademarks are the property of their respective owners. Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those designations appear in this book, and Peachpit Press was aware of a trademark claim, the designations appear as requested by the owner of the trademark. All other products names and services identifi ed throughout this book are used in editorial fashion only and to the benefi t of the trademark owner with no intention of infringement of the trademark. No such use, or the use of any trade name, is intended to convey endorsement or other affi liation with this book.

ISBN 0-321-17408-9

9 8 7 6 5 4 3 2 1

Printed and bound in the United States of America

1Why Wireless?

Wireless. The word evokes those heady days long ago when radio ruled the entertainment world and families gathered around a console radio the size of a coffee table and marveled at a technology that emitted disembodied voices from far away. Though we now take radio for granted, back then it was pure magic each time words and music came out, without even the need for wires between the receiver and a transmitter that could be miles away.

Fast forward to the present, where a different kind of radio is taking the computer world by storm. Now the radios are minuscule chips embedded in credit card–sized devices that plug into computers themselves not much larger than pads of writing paper. These radios transmit and receive not the scratchy voices and sound effects of a newscast but tiny chunks of zeros and ones—computer data. In the past, radio connected people and made possible the fi rst mass culture; today, radio connects our computers with wireless networks and the greater Internet.

What’s most amazing about wireless networking is how powerful a concept it is, considering the underlying simplicity. There’s nothing much new in wireless networking, but the connection of different aspects of computing and transmission makes it a compelling choice, and even hints at the roots of social revolution as people communicate with one another in new and ever more mobile ways.

Networks that run over wires have long provided the same communication between computers that wireless networks can offer, and, what’s more, data generally fl ows over less-expensive wired networks at much faster speeds. Faster

The Wireless Networking Starter Kit2

speeds and cheaper hardware turn out not to be the point—what’s compelling about wireless networking is the combination of fl exibility, network ubiquity, and the distance between network nodes that takes wireless networking far beyond the mundane wired world. Plug in a few inexpensive pieces of gear, fi re up a connection, and you can wander around your home or offi ce, go out on the patio, or visit a café, with full network access the entire time. Suddenly you’re networking in a way that seemed like science fi ction just a decade ago.

Unplug, Tune In, Power UpLook behind your desktop computer. If it’s anything like our computers, there’s a rat’s nest of wires back there. The monitor and the keyboard connect to the computer, the monitor and computer both plug into electrical sockets in a power strip that itself plugs into a wall outlet, and then there are cables snaking to and from the printer, the mouse, and so on. Now imagine a computer completely freed of cables and wires. It might be diffi cult if you’re imagining a desktop computer with a heavy monitor, but think instead about a laptop computer, with its integrated screen, keyboard, and mouse, all receiving power from a battery inside. It doesn’t need any wires at all, at least as long as its battery lasts.

With a laptop, you’re free to work wherever you like—in bed, on the couch, on an airplane, or in a coffeehouse. And with today’s laptops, which combine speedy processors and beautiful screens in svelte packages of only a few pounds, you aren’t even making many tradeoffs for your sudden freedom from your desk. But until recently, there was one thing you did give up—Internet access.

We won’t go on about how amazing the Internet is because you already know all about the power of exchanging email, browsing the Web, and, especially for younger people, relying on instant messaging to remain in constant contact with friends. But amazing it is—and we’ve been using and writing about the Internet since well before it became the cultural phenomenon it is today. (In fact, Adam wrote one of the very fi rst books about the Internet back in 1993, and within a few years, hundreds of thousands of people had used his Internet Starter Kit series of books to get on the Internet for the fi rst time. Glenn founded Starter Kit series of books to get on the Internet for the fi rst time. Glenn founded Starter Kitan early Web development company in 1994 and fi nds modem use like sucking a watermelon through a straw.) Today’s computers are communication devices, and to communicate, they require Internet access.

This need for Internet access hobbled laptops for a while, because while you could work without the laptop plugged in as long as its battery held out, if your work required the Internet, you had to have a modem cable or Ethernet cable tethering your computer to the wall. And once you were tethered to the wall,

Chapter 1 | Why Wireless? 3

you most likely would have plugged in the power adapter to keep the battery charged. And since it’s a pain to move your power adapter around, you probably would have left it near your desk. Before you knew it, your laptop was tied down to your desktop as securely as any larger computer.

Enter wireless networking. Suddenly, with the addition of two inexpensive pieces of hardware—a wireless network card to plug into your computer and an access point—you could once again use your laptop anywhere within range of your access point while enjoying Internet connectivity. The bed, the couch, the back yard, they all became available once again. The freedom offered by wireless networking doesn’t stop when you leave home. Many offi ces have jumped on the bandwagon, networking conference rooms and lounges so employees can access shared fi les and Internet information resources no matter where they are. (An added benefi t is checking your email during particularly boring meetings, but you didn’t hear us say that.) Business travelers have come to expect wireless Internet access in airports, at trade shows, and even in coffeehouses and sports arenas.

Wireless networking also has strong grass-roots support. Community-minded folk in many cities around the world have put up large wireless networks that cover whole neighborhoods, so if you’re in Bryant Park in New York City, or almost anywhere in Ashland, Oregon (home of the annual Oregon Shakespeare Festival), accessing the Internet is merely a matter of opening your laptop, though we’re sure you wouldn’t do that in the middle of Romeo and Juliet.

Put bluntly, wireless networking is one of the most exciting developments in computing in the last few years, not because it makes possible any new technical feats, but because it lets computers fi t better into our lives. People weren’t meant to sit in the same place, day in and day out, and while those of us who spend our time working on computers have made that sacrifi ce for years, the combination of a slim laptop and wireless networking providing Internet access wherever we go is tremendously liberating.

It’s just freaking cool.

Wireless Networking RootsSo what exactly do we mean when we talk about wireless networking? For the purposes of this book, we’re almost always talking about a short-range, unlicensed radio technology called IEEE 802.11b, also known by the more mellifl uous moniker Wi-Fi (it’s an odd shortening of “wireless fi delity” by a Wi-Fi (it’s an odd shortening of “wireless fi delity” by a Wi-Fitrade association). Although we may occasionally switch back and forth for


accuracy, we mostly use Wi-Fi throughout the book to avoid confusion. Wi-Fi is by no means the only wireless networking technology, but it’s by far the most common (we look at the other major technologies in the next chapter). Let’s take a quick spin through the development of wireless networking.

The fi rst wireless network was developed at the University of Hawaii in 1971 to link computers on four islands without using telephone wires. Wireless networking entered the realm of personal computing in the 1980s, when the idea of sharing data between computers was becoming popular. Some of the fi rst wireless networks didn’t use radio at all, though, instead relying on infrared transceivers. Unfortunately, infrared never took off because infrared radiation can’t penetrate most physical objects. Thus, it required a clear line of sight at all times, a tricky thing to accomplish in most offi ces. (Even modern infrared is still quite low bandwidth, when it works.)

Radio-based wireless networks started to gain momentum in the early 1990s as chip processing power became suffi cient to manage data transmitted and received over radio connections. However, these early implementations were expensive and proprietary—they couldn’t communicate with one another. Incompatible networks are doomed to failure, so in the mid-1990s, attention coalesced around the fl edgling IEEE 802.11 standard for wireless communication. Early generations of IEEE 802.11, ratifi ed in 1997, were relatively slow, running at 1 and then 2 megabits per second (Mbps). They were often used in logistics: warehouses and inventory operations where wires weren’t feasible or would be enormously expensive to maintain.

It was clear that the technology could be pushed much further, and in 1999 the IEEE fi nalized the 802.11b standard, increasing the throughput of wireless networks to 11 Mbps (to compare, standard 10Base-T wired Ethernet runs at 10 Mbps). Although many companies were involved in creating the 802.11b specifi cation, Lucent Technologies and Apple Computer led the way in producing affordable wireless network devices for the consumer market. (Other companies like BreezeCOM and Aironet Wireless Communications were already selling expensive equipment aimed at the corporate market.)

NOTEThe IEEE ratifi ed the much faster 802.11a standard fi rst. However, technical and political realities delayed development. The fi rst 802.11a gear shipped in the middle of 2002. We address 802.11a in more depth in Chapter 3, How Wireless Works.


The turning point for wireless networking came in July of 1999, with Apple’s release of its AirPort technology. AirPort was an industry-standard compliant version of IEEE 802.11b, and Apple jumpstarted the market by charging only $100 for a wireless network card that fi t inside different models of the Macintosh and $300 for an access point (which Apple called an AirPort Base Station). It took more than a year for other companies to drop their prices to the level Apple set, but by introducing wireless networking to the much-larger PC market, these other companies were able to continue lowering prices. As we write this book, the cost to equip a single PC or Mac with a Wi-Fi card is between $50 and $100, and an access point costs less than $150.

Throughout the last few years, capabilities have increased as prices have dropped, and ease of use has improved so anyone who can set up a computer can also set up a wireless network, complete with a shared Internet connection. We’ve come a long way in a short time, and with the popularity of wireless networking, the future looks equally as bright as the recent past. For a look at what we can expect to come down the wireless pike, read Chapter 10, The Future of Wireless.

Who Should Read This Book?We had a particular audience in mind when we wrote this book. You’ll get the most out of the book if one of the following is true of you.

• I’ve just bought a laptop, and I want to share my desktop computer’s Internet connection. How can I share that connection cheaply and easily?

• I have a small wired network to share fi les and an Internet connection between two desktop computers, but now I want to add my laptop to the mix without needing any network cables. What should I buy to add my laptop to the network?

• I’ve just moved, and running Ethernet cables where I need network access is too expensive and too much work. I want all my computers to share an Internet connection without pulling cable. Will wireless networking solve my problems?

• I have a wireless network in place and working, but I can’t receive the signal in some rooms. How can I extend my network’s range?

• I bought everything I need, and I set up my wireless network, but I just can’t make the darn thing work with my Internet connection. Can this book tell me what I did wrong?


• I travel a lot. What do I need in terms of hardware, software, and accounts to get wireless Internet access wherever I go?

• I can’t get DSL (Digital Subscriber Line) or cable modem access to the Internet, but I’ve heard that I might be able to get high-speed wireless access to the Internet in my location. How do I make this happen?

• I’m trying to understand how wireless networking works so I can advise my department on whether or not we should invest in the technology. Can this book explain the basics of wireless networking, tell me what’s coming up, and point to useful Web sites where I can learn more?

• My friends and colleagues turn to me as their Internet and computer guru, and they’re all interested in wireless networking. What information do I need to start setting up networks for home users?

• I’m worried about crackers tapping into my wireless network and stealing my company’s sensitive product plans. How do I ensure that my network is secure?

We’re confi dent that if your needs are along the lines of these questions, you’ll fi nd the information you need in this book. Or, in the event that something has changed since the book was published, we may have covered the topic on the book’s Web site at www.wireless-starter-kit.com, or on Glenn’s 802.11b Networking News site, at http://80211b.weblogger.com/. You can get started http://80211b.weblogger.com/. You can get started http://80211b.weblogger.com/using the Web sites referenced throughout the book.

Our goal is to provide practical information and advice for anyone trying to work with a wireless network, although we should note that this book isn’t for complete novices. If you don’t yet know the basics of using Windows or a Macintosh, for instance, we recommend reading an appropriate beginner’s book fi rst—Peachpit Press offers a number of good ones—and then coming back to this book.

On the other end of the spectrum, we don’t examine wireless networking at the protocol level, dissect packet headers, discuss the detailed physics involved with radio reception, or handle any other truly deep technical topic. (If you need that level of detail, we recommend Matthew Gast’s 802.11 Wireless Networks: The Defi nitive Guide.) That sort of information is primarily useful to those few people designing wireless networking hardware, writing wireless software, or setting up community-wide mesh networks, and we want to focus this book on practical issues experienced by large numbers of people.


Real Life Wireless NetworkingBefore we get into the nuts and bolts of wireless networking (so to speak), we’d like to let you know where we’re coming from so you can see that we’re not just armchair technologists—we’ve lived this stuff. We’ve both been involved with technology for more than 20 years, and over the last 12 years, we’ve devoted large chunks of our time to writing about technologies that fascinated us because we love explaining complex topics.

Since 1990, Adam has published TidBITS, a weekly electronic newsletter that covers topics of interest to Macintosh and Internet users. He has also been a contributing editor at MacUser, MacWEEK, and Macworld. Along with the best-selling Internet Starter Kit series, Adam has written and co-authored a Internet Starter Kit series, Adam has written and co-authored a Internet Starter Kitnumber of other books, including Internet Explorer Kit for Macintosh (with Bill Internet Explorer Kit for Macintosh (with Bill Internet Explorer Kit for MacintoshDickson), Eudora for Windows & Macintosh: Visual QuickStart Guide, The Race for Bandwidth (ghostwritten with Steve Manes for our late friend Cary Lu), Crossing Platforms: A Macintosh/Windows Phrasebook (with David Pogue), and Crossing Platforms: A Macintosh/Windows Phrasebook (with David Pogue), and Crossing Platforms: A Macintosh/Windows Phrasebookmost recently, iPhoto 1.1 for Mac OS X: Visual QuickStart Guide.

During much of that time, Glenn has been a freelance writer, founding Point of Presence Company in 1994, one of the fi rst Web site development companies—Peachpit was one of his fi rst clients, deploying a market-basket system for buying books in 1995. He also did a six-month stint as Amazon.com’s catalog manager, took some time out to beat Hodgkin’s disease, and has co-authored (with TidBITS managing editor Jeff Carlson) three editions of Real World Adobe GoLive. Glenn currently writes for publications such as The Seattle Times, Wired, The New York Times, and the O’Reilly Network. He also runs the popular 802.11b Networking News Web site and is widely recognized as one of the leading journalists covering wireless networking.

We’ve known each other for over 10 years, meeting via email in the early 1990s and becoming close friends when we both lived in Seattle. Since Adam left Seattle to move back to his home town of Ithaca, New York, we see each other mostly at trade shows and other industry events and interact the rest of the time via phone, email, and instant messaging.

With those résumé-like bits out of the way, we’d like to switch to another way of explaining where we’re coming from, this time by telling you stories about the wireless networking events that captivated us and turned us into the advocates we’ve become. For each story, note the takeaway message at the end—with these stories we’re trying not only to relate important events we’ve experienced, but also to illustrate important points about how you can you can youuse wireless networks.


The Introduction of AirPort (Adam)The watershed event that introduced wireless networking to the world at large happened in July of 1999. The place was New York City’s Jacob Javits Convention Center, and the event was the semi-annual Macworld Expo trade show. Steve Jobs hadn’t been back at Apple all that long, and at least from the point of view of the media, the company was rising from its ashes.

For those who have never seen one, a Steve Jobs keynote is a thing of wonder. Most computer industry keynotes are dry talks by people qualifi ed by their company’s position in the industry, not their presentation skills. But in the parlance of the industry, Jobs gives good demo, and this demonstration would be remembered for a long time.

Keep in mind that—although wireless networking had existed for a number of years—it had always been expensive, slow, and unreliable, and it’s safe to say that most people hadn’t realized it was even possible. (Glenn interjects: “I was so dubious when I fi rst heard about it, that I foolishly didn’t even try it out for another year.”) So when Jobs showed the fi rst iBooks, Apple’s consumer-oriented laptops, and announced that the addition of a $100 card would let them network with other computers and even access the Internet via a $300 access point, the audience was in shock. Apple called the technology AirPort, but Jobs was careful to point out that it was an implementation of the IEEE 802.11b industry standard for wireless networking.

Though we in the audience believed what Jobs said (when you’re in his presence, it’s almost impossible not to believe everything he says, thanks to his well-known Reality Distortion Field), Apple hammered home the freedom enabled by wireless networking when Jobs introduced Apple’s vice president of marketing, Phil Schiller, who appeared on a platform 25 feet above the fl oor. Holding a new iBook that was playing a QuickTime movie received over the wireless network, Schiller actually jumped off his platform to a large foam mat below to prove that there were no wires involved. As Schiller stood up and brandished the iBook triumphantly, a video camera zoomed in on the iBook’s screen to show that the movie was still playing. Talk about magic.

TAKEAWAY MESSAGEIf you need to demonstrate wireless networking to someone who doesn’t quite understand why it’s cool (such as a recalcitrant boss or spouse), think of something you can do with a wireless network that would be utterly impossible with a traditional wired network, like taking a stroll outside while browsing the Web. Wireless networks demo well.


Bringing a Wireless Network Home (Adam)After Apple’s compelling demonstration of wireless networking in July of 1999, a solution presented itself for a problem my wife Tonya and I had been trying to fi gure out. We’d had a baby, and although Tonya was intending to take a year off from her freelance writing and editing work, she hadn’t counted on the extent to which our particular child would want to be held at all times. We initially moved her desk and Power Mac 7600 into the dining room so she could browse the Web or read email while nursing Tristan. It worked, but it wasn’t a decorating look to emulate, especially due to the 50-foot, blue Ethernet cable snaking across the kitchen and dining room fl oor. Plus, when Tristan started crawling, the cable became an attractive plaything.

For an early Christmas present, then, we bought an iBook with an AirPort card and one of Apple’s UFO-like AirPort Base Stations. I connected the AirPort Base Station to our internal Ethernet network, ran through Apple’s AirPort Setup Assistant, and with no fuss, Tonya’s new iBook could access the Internet from almost anywhere in the house (see Chapter 5, Building Your Wireless Network). She encountered a few dead spots where the signal was blocked by too many walls, but they weren’t in critical areas. And yes, as soon as we got it working, we walked around the house holding the open iBook, watching the signal strength indicator and browsing random Web pages to prove it could be done. We even took the iBook outside and walked over to our neighbors’ house, getting as far as their front porch before we lost the signal. Once again, it was pure magic.

The iBook proved to be a workhorse machine for Tonya, popping on the wireless network effortlessly during long breastfeeding sessions. She loved being able to sit in a comfortable chair and the convenience of having the laptop readily available during Tristan’s infrequent naps. Who knew that what today’s nursing mother really needs is a laptop and a wireless connection to the Internet?

TAKEAWAY MESSAGEIt’s easy and inexpensive to set up a simple wireless network that lets a laptop computer share an Internet connection. You can do it in your home or offi ce for as little as $200 and no more than an hour or two of work (aided by this book, of course!). And if you think about it, you can probably come up with some situations in your life that would be made easier if you could have a wireless Internet connection anywhere in your house or yard.

Evolving from Wired to Wireless (Adam)Every year, I attend a truly unusual conference. It’s called MacHack, and it’s a developer’s conference put on by members of the Macintosh developer


community for their programming peers. Unlike most conferences, organized as they are by a trade show management fi rm for a stereotypical user, MacHack is designed for programmers by other programmers: the conference starts at midnight with unlimited pizza and a keynote that’s been known to last until 6:00 a.m, programmers stay up for 72 hours straight writing code to show off at the Hack Contest, and caffeinated beverages fl ow freely. Full Internet access is provided, of course, and the fi rst few years I went, the standard lobby scene was of about fi fteen round tables, each populated by programmers hunched over their PowerBooks, Ethernet cables snaking out to an Ethernet hub on each table.

(Don’t assume that this means the MacHack attendees are antisocial. In fact, just the opposite is true, and they’re often working together on code for the Hack Contest. The beauty of having constant wireless Internet access is that questions that come up in conversation can be answered immediately, and those people who weren’t able to attend can stay in touch with friends who are at the conference.)

In 2000, the fi rst year of MacHack after Apple introduced AirPort, the hubs hadn’t disappeared, but fewer were necessary, since so many people had immediately bought AirPort cards for their PowerBooks and iBooks. I had a Wi-Fi–compatible Farallon SkyLINE card for my PowerBook G3 that year, which was a bit slow and clunky, but worked fi ne for Internet access. The CompUSA across the parking lot from the hotel did a brisk business in wireless network cards as those people who hadn’t come prepared to hop on the MacHack wireless network realized how cool it was.

By 2001, I’d switched to one of Apple’s white iBooks, complete with an internal AirPort card, and using the wireless network at MacHack was as smooth as butter. A few Ethernet hubs were still in place for the stragglers who hadn’t yet joined the wireless revolution, and also for those whose Titanium PowerBook G4s were having trouble seeing the wireless network (gee, do you think encasing a radio in titanium will hurt signal reception?).

In 2002, the only machines that didn’t have wireless network cards installed were those that had been brought for historical effect, and the CompUSA next door sold only a single card, to someone whose laptop had broken just before the conference and who had forgotten the card for the older PowerBook he borrowed from a friend. Once it has set in, the addiction to wireless networking is hard to break.


Although I suspect the conference network administrators will keep at least one or two Ethernet hubs available just in case, it’s clear that for MacHack at least, wired Ethernet has gone the way of the fl oppy disk—still available if necessary, but certainly not preferable.

TAKEAWAY MESSAGEWireless networking works incredibly well in locations where running wires is logistically diffi cult or expensive, particularly when the network is only necessary for a short time. Also, among certain communities, wireless networking has become almost ubiquitous; these people assume they’ll be able to fi nd a wireless network almost anywhere they go. If you know someone like this, they’ll probably be happy to help you set up a wireless network.

Replacing Wires with Wireless (Glenn)Several years back, a bunch of like-minded computer journalists and graphic designers, including myself, moved into the top fl oor of a beat-up old building in Seattle’s Green Lake neighborhood. The two-story building had been mildly renovated, and had new tenants downstairs as well: a group of running coaches that installed workout equipment and led organized runs for amateurs and professionals.

As we got to know our downstairs neighbors, we started to extend ourselves, fi rst showing them how to connect to our AirPort Base Station upstairs so they could share our fast Internet connection, and later drilling a hole in the fl oor so that we could run an Ethernet cable down and hook up their wired machines as well.

When the coaches leased some additional offi ce space next door, they faced a conundrum: there was no good way to string a wire from one building to the next. The wireless network wouldn’t work because the next-door building was mostly underground in the back and had thick concrete walls that blocked the signal except in the very front.

We looked into a number of alternatives, and I fi nally found a simple way to link our networks: a device from networking equipment maker Linksys with the ungainly name WAP11. Linksys had designed the WAP11 as a cheap wireless access point, but it had a unique extra: it could be set to a different mode in which it could bridge, or connect, two Ethernet networks.

We bought two WAP11s, which each cost about $150 then (they’re down to about $100 now), and pointed them at each other through windows that provided a line-of-sight view from one building to the other. After a lot of


monkeying around and months of tweaking—the original fi rmware in the WAP11 was funky but kept improving—we ended up with a reliable, full-time connection that pooled our two offi ces, eliminating their need for a $60 per month additional Internet subscription.

If we were solving this problem today, we’d only need a single piece of gear, also from Linksys: the $130 WET11 Wireless Ethernet Bridge, which we rave about later in Chapter 5, Building Your Wireless Network.

TAKEAWAY MESSAGESometimes a wireless network can help solve what would otherwise be a tricky or expensive wiring problem. Cheap wireless bridges that can accept external antennas are making it easier to connect buildings via wireless networks.

Creating Ad Hoc Networks (Adam)Don’t labor under the false impression that wireless networking requires all sorts of hardware. In fact, if you simply want to transfer fi les back and forth, you can create a quick network between two laptops using standard wireless network cards—no access point necessary. And, with capabilities built into the Mac OS (both Mac OS 9 and Mac OS X, starting with version 10.2), you can even share an Internet connection between those two laptops.

I fi rst used wireless networking to share an Internet connection between two laptops while sharing a hotel room with my friend and colleague Jeff Carlson during Macworld Expo in 2000. Jeff had a neat device, called a Ricochet modem, that was essentially a proprietary radio modem that enabled a computer to access the Internet wirelessly at low speeds (about 33 kilobits per second, about the same as a normal modem that connects to a telephone line) in several cities around the U.S., including Seattle, where Jeff lives, and San Francisco, where we were for Macworld Expo. We also both had standard 802.11b wireless network cards in our PowerBooks, so rather than suffer the expensive local phone calls and frequent disconnects that are endemic to hotels, Jeff used the Software Base Station feature of Apple’s AirPort software to share his Ricochet-based Internet connection with my PowerBook.

So there we were, sitting on our beds in a hotel room hundreds of miles from home, checking email and browsing the Web with absolutely no wires involved. Even we, who encounter each new technology as it comes down the pike, found it an impressive feat. Plus, it hadn’t taken any unusual hardware or esoteric knowledge—we were using off-the-shelf wireless network cards and capabilities built into the Mac OS. Anyone could have done it. And you can, too, by reading Chapter 4, Connecting Your ComputerConnecting Your Computer.Connecting Your Computer


TAKEAWAY MESSAGEAd hoc wireless networks are simple to set up and work well for sharing fi les or even Internet connections while traveling.

Internet Access on the Road (Adam)Unfortunately, the Ricochet service, which Jeff used happily for several years to access the Internet in numerous coffeehouses throughout Seattle, fell victim to the dot-com bust and went under mid-way through 2001. Interestingly, after the terrorist attacks in New York City on September 11, 2001, the Ricochet network in New York City was brought back to help rescue workers communicate. (In August 2002, Aerie Networks, the company that bought Ricochet’s assets for pennies on the dollar, started to reactivate parts of the network.)

Luckily, places where you can access the Internet via a Wi-Fi wireless network have proliferated in the last few years, and it’s become easy to get Internet access via a wireless network in many parts of the world (see Chapter 7, Taking It on the Road). Glenn and I have personally found wireless networks we could use for Road). Glenn and I have personally found wireless networks we could use for RoadInternet access in coffeehouses, airports, trade show fl oors, and city parks. Perhaps the most compelling demonstration of how well wireless networking can work for Internet access was when my wife and I visited Ithaca on a house-hunting trip in May of 2001. We had a few extra minutes in an indoor shopping center in downtown Ithaca, so I opened up my iBook to fi nd not one, but two wireless networks I could access. A minute or two later, I’d checked my email.

Later that day, we had to pick up some groceries, and since our son Tristan was asleep in his car seat, I volunteered to stay in the car with him and work on the iBook while Tonya shopped. I was stunned to discover a wireless network I could access right there in the parking lot, and since it was the day I publish the weekly issue of TidBITS, Internet connectivity was extremely welcome. There I was, sitting in a car in a grocery store parking lot, downloading fi les, verifying Web sites, and responding to email about the issue from other editors—all while Tristan snoozed in the back seat. I can’t say that I’ve made a point of going back to that parking lot just to get on the Internet, but at that particular moment, it was great to know that I didn’t have to drive somewhere to plug my laptop into a telephone line so I could suffer with a slow modem connection to the Internet.

TAKEAWAY MESSAGETransferring your email while traveling used to be a diffi cult proposition, but thanks to the proliferation of wireless networks, it’s now likely that you can get wireless Internet access in most of your frequent destinations.


Cutting Across a Yard or Stealing Sheep? (Glenn)During Macworld 2002 in New York City, I found myself in one of the best cheap hotels in New York: the Hotel Pennsylvania, right across from Madison Square Garden, and a convenient walk or bus ride to the Javits Convention Center. Even though my room was located in a weird bend of the building, when I stuck my iBook into the window frame, I was able to pick up an open wireless network.

The wireless network connection was fast enough to retrieve my email and browse the Web, but when my cell phone rang at 11:30 p.m. one of the nights I was in my room, I freaked out. The voice asked for me by name and said its name. I hung up. I thought, “Holy cats, someone’s monitoring their connection and spotted my secure session for email back to my Seattle mail servers, and then used my InterNIC domain record to fi nd my phone number.”

The person never called back, the connection kept working, and I calmed down. But the experience did hammer home the nature of using someone’s connection without their knowledge or permission.

TAKEAWAY MESSAGEIs it stealing someone’s resources when you use their unknowingly unsecured network, or is it just like using a paved path to cut across someone’s yard to get to where you’re going? It’s a tricky issue, and one we examine more in Chapter 10, The Future of Wireless.

Wireless on the High Seas (Glenn)In the truly remote areas of the world, far from cell phones’ incessant ringing, wired connections, and TV sets, you’d think we could just relax and leave the Internet alone. Forget it: we’re geeks, and wireless geeks at that. In May of 2002, Adam and I found ourselves (and our families) on the ms Volendam cruise ship during the MacMania conference, but despite the remote (and fl oating) locations off the coast of Canada and Alaska, we still had almost continuous Internet access.

The conference was the brainchild of Neil Bauman, captain and CEO of Geek Cruises, and it brought together many Macintosh gurus to speak on Mac-related topics. Appropriately enough, Adam and I were team-teaching a half-day session on wireless networking, though we had to compete with amazing views in Glacier Bay—which, disconcertingly, we could see but our audience had their backs to.

Luckily enough, both for our session and for the rest of the conference, Geek Cruises had arranged to provide wireless Internet access. The Internet


connection came over a satellite feed that offered only about 100 Kbps—we were so far north that the satellite’s signal was almost tangential to the Earth, reducing speed tremendously. Slow though it was, it worked fairly well, and we were able to use it via the internal wireless network Geek Cruises had set up. Initially, Geek Cruises wanted to provide access throughout the ship, but due to political (the ship’s offi cers were unhappy about the amount of wire necessary to connect access points on different decks) and technical (all the metal in the ship blocked signals quickly) issues, the access ended up centered on the ship’s library.

The fact that Internet access was available only in the library turned out to be a blessing in disguise, since it made that part of the ship into conference central, where people would gather, retrieve email, surf the Web, exchange stories, and warm themselves by the digital glow of the Internet connection. It was a bit like Adam’s description of the hotel lobby at the MacHack developer’s conference.

Our resident celebrity, John de Lancie, who portrayed “Q” on the Star Trek: The Next Generation television series, is an avowed Macaholic, and during one stint in the library, he watched several of the experts disassemble his PowerBook to install a wireless card so he too could be part of the action.

It was an unanticipated and ancient human response. The ubiquitous availability of the wireless Internet connection could have strewn us about the ship. Instead it drew us together.

TAKEAWAY MESSAGEIn a public space, creating a place where people can gather physically to share a wireless Internet connection is an amazing way to help people come together as a group.

Long-Range Wireless Internet Connections (Adam)Although we mostly think of wireless networking as a useful replacement for small wired networks, there’s no particular reason that has to be true. Wireless networks can usually replace wired networks in almost any situation, even as your main connection to an Internet service provider. Getting your Internet access via wireless especially makes sense if you live somewhere with poor phone lines that don’t support DSL or where cable television doesn’t exist at all.

The trick is in the antenna—most wireless network cards can communicate within about a 150-foot range because their antennas are tiny things either


coiled up in the card or strung around the inside of the computer. Connect a big antenna of the right type to a wireless network card and you can send and receive signals over distances of up to 20 miles or more. It’s just like the old days of television, where you’d see houses with huge antennas on the roof to pull in far-away TV stations.

Of course, getting wireless Internet access is possible only if an ISP (Internet service provider) provides it, or if you’re willing to put money and effort into both sides of the connection. When I moved from Seattle, Washington to Ithaca, New York in 2001, though, my research into Internet options in Ithaca turned up the fact that an Ithaca ISP called Lightlink offered wireless Internet connections at reasonable rates. And, most important, one of its towers was within line of sight from my new house. Lightlink wouldn’t promise reliability (no one wants to climb a transmission tower to fi x an antenna during an ice storm), but I was intrigued and began the process of seriously researching what it would take to attach a home network to a wireless Internet connection from Lightlink. I also signed up for cable modem service from Road Runner, a major cable Internet provider, but since I’d heard sporadic reports of poor reliability about Road Runner in Ithaca, I fi gured that between the cable modem connection and the long-range wireless connection, I’d be able to maintain reliable Internet connectivity no matter what.

Establishing my wireless Internet connection proved more complicated than I’d anticipated (and than it is now, just a year later). I had to fi nd an appropriate antenna, track down outdoor Ethernet cable (so that I didn’t have to run a 50-foot, blue Ethernet cable along my entire upstairs hallway), and confi gure all the network details. I won’t go into the specifi cs here, but rest assured that everything I learned is in Chapter 8, Going the Distance.

In practice and regular use, though, my long-range wireless connection has been fl awless. Actually, that’s not true—it went down for about an hour once in the last year. I can handle that kind of reliability. And once, there was a truly unusual event. The transmitter I use is about two miles away, and I need a fairly large parabolic antenna to pick up the signal normally. However, one winter night, it snowed hard, and something about the snow crystals affected the signal and made it so all my computers could pick up the signal from the tower without the big antenna. (The moral of the story is that many variables can affect radio signal strength. Some people have been disappointed to lose a strong signal entirely when the trees leaf out.)


TAKEAWAY MESSAGEWith the addition of an antenna to wireless networking hardware, you can increase the range of a wireless network to as much as 20 miles (assuming line of sight). That could make it possible for you to get wireless Internet access from a local wireless ISP, or, by setting up both sides of the wireless connection, you could provide Internet access to a remote location.

Wireless Community Networks (Glenn)Soon after wireless networking equipment dropped into the range of the serious hobbyist and early adopter, people started playing with extending the range of networks beyond a few hundred feet using homemade antennas. Rob Flickenger, a system administrator at O’Reilly & Associates, a computer-book publisher, conference organizer, and editorial site in California, took a hard look at what expensive antennas did, and decided he could do the same thing with a Pringles can and some metal tubing and washers.

Sounds ridiculous, but a Pringles can was the right size to hold the antenna and mount an external connector to attach a cable to a wireless card or access point. Using imprecise measurements and hardware supplies that cost less than $30, Rob ate the potato chips, assembled an antenna, and saw remarkable increases in the distance his network could span.

The point of making a Pringles-can antenna was twofold: the sheer joy and silliness of it; and the notion that individuals could create powerful equipment cheaply that would allow them to link networks together, share bandwidth, and build communities around themselves.

Dozens of community networking groups have formed around the U.S. and around the world to extend the Internet and local networks beyond just a few houses or businesses, creating a cloud of access in neighborhoods, often those poorly served by affordable DSL and cable modem service.

In the process, these groups have learned a lot about fi nding networks, meeting people, and building antennas. The goal of these groups, generally—as they’re all made up of highly independent people—is to spread the message about wireless networking as a tool, and to bring together people who pool resources for the greater good.

One fl aw in the ointment, as it were: many of the shared network connections that community networks use stem from high-speed consumer accounts that


specifi cally disallow sharing bandwidth. Some ISPs have now publicly announced their support for this kind of sharing, while others have sent lawyer letters to users sharing their service. It remains to be seen how it will all shake out, but we look more at the confl ict in Chapter 10, The Future of Wireless.

The more people participate in these community groups, the more likely the networks will grow large enough and redundant enough to provide real access to people throughout neighborhoods in many towns and cities around the world.

TAKEAWAY MESSAGEAs a user, it’s worth asking around and investigating any public areas in which you spend a lot of time, since it’s increasingly likely that some sort of wireless network is in place. And if you’re the activist sort who likes making communities better places to live, a bit of research could help you start a group to bring a wireless community network to your town or neighborhood.

What’s Coming UpWe hope you have an appreciation for why wireless networking is so utterly cool, not to mention useful and money-saving. Let’s dive into the details now—here’s a preview of the upcoming chapters.

Chapter 2, Networking Basics, is a crash course in the basics of networking. Though wireless networks are pretty easy, as soon as you want to do something unusual, you’ll fi nd it signifi cantly simpler if you understand just how data fl ows through a network. Don’t worry—it’s not too geeky, and if you’ve ever watched trains go by, you’ll pick up networking just fi ne.

Chapter 3, How Wireless Works, looks at the details of how wireless networks actually work, from the basics of radios to the hardware that you need to connect different types of computers to a wireless network. Pay attention and you’ll even learn about the important role actress Hedy Lamarr played in the evolution of wireless networking.

Chapter 4, Connecting Your Computer, dives into step-by-step instructions on how to confi gure your computer to connect to wireless networks, share an Internet connection, and share fi les. So, if you have a Mac and a PC and want them to share a cable modem Internet connection via your wireless access point, just turn to Chapter 4 to fi nd what you need.


Chapter 5, Building Your Wireless Network, goes to the next step, offering real-world advice on how to plan and build a wireless network, complete with a guide on how to buy a wireless gateway that connects your little network to the rest of the world.

Chapter 6, Wireless Security, takes a realistic look at the sometimes seamy world of security. Worried about crackers stealing your passwords or poking into your fi les? Chapter 6 arms you with both the knowledge necessary to evaluate your paranoia level and the tools you need to ensure that even the most paranoid are comfortable.

Chapter 7, Taking It on the Road, concentrates on how to use wireless Internet access when you leave your house or offi ce. You’ll learn what hardware and software you need, how to confi gure your laptop to connect to wireless networks so you can send and receive email, and how to fi nd wireless networks wherever you are. We even show you a secret symbol chalked on sidewalks and buildings that identifi es wireless networks in the vicinity.

Chapter 8, Going the Distance, focuses a long lens on how you can pick up a wireless Internet connection from miles away with only the addition of an inexpensive antenna, or, if you’re really cheap, a Pringles can. For those who don’t have a wireless ISP (often abbreviated to WISP), we even look at what’s necessary to handle both sides of the connection. Get out your binoculars and start scanning the horizon for wireless.

Chapter 9, Things That Go Bump in the Net, admits, unlike the manufacturers of most computer equipment, that something could in fact go wrong. Along with a general troubleshooting guide, we even go one better, looking at common problems and offering advice and solutions.

Chapter 10, The Future of Wireless, peers into the crystal ball to examine what’s coming down the pike, both in terms of new technologies that promise faster, stronger, and more secure networks, and in terms of societal changes and challenges we all face as wireless networks become ever more common.

Chapter 3 | How Wireless Works 61

Wireless Network AdaptersThe second piece of hardware that’s necessary for any wireless network is a wireless network adapter. As with access points, you may run into different names for these devices. For instance, Apple calls its wireless network adapter an “AirPort card,” and other manufacturers may have other names. Since these adapters install in computers that are clients of the access point, you often see the term “client” added to the name of the software that controls the adapter.

NOTEA client is part of a pair; a server is the other half. A server is set up to handle requests from many different machines or users; clients talk to one server for each task. In wireless networking, the access point is effectively a server, even though it’s rarely called that.

Wireless network adapters come in quite a few shapes and sizes, and although the following list may seem intimidating, you can refer to Table 3.1 to pick the type that’s most appropriate.


Internal Wireless CardsThe best option, if it’s available for a client computer, is often an internal wireless network card. They’re cheaper and less obtrusive than external adapters. The only downside to internal wireless cards is that they can be more trouble to install and unless they’re designed properly, the computer’s case can block the network signal somewhat, reducing range.

• PC Cards. The familiar PC Card slot is typically found only in laptops. Since laptops are ideal for use with wireless networks, many kinds of wireless network cards are available initially, and sometimes only, in PC Card form. Most wireless PC Cards have antennas built in or that pop out, and although they’re fairly small, they often stick out from the body of the laptop.

NOTEPC Cards used to be called PCMCIA cards. PCMCIA offi cially stands for Personal Computer Memory Card International Association, despite its waggish expansion to People Can’t Memorize Computer Industry Acronyms.

Table 3.1

Picking the Most Appropriate Wireless Network Card

PC Card PCI USB Ethernet Compact Flash

Secure Digital

AirPort Card

Desktop PCs p 1 2

Laptop PCs p 1 2

Pre-AirPort Power Macs p 1 2

USB-only iMacs p 1

FireWire iMacs 1 1 p

PowerBook G3s p 1 1

Apple iBooks 1 1 p

Titanium or FireWire-only PowerBooks

1 1 1 p

PocketPC handhelds 3 3

Palm handhelds 4

p Preferred adapter 3 May require adapter depending on PocketPC model

1 For computers with built-in or add-on USB 4 Certain newer Palm handhelds have an SDIO slot

2 For computers with built-in or add-on Ethernet

Chapter 3 | How Wireless Works 63

• PCI card. Most desktop computers these days have PCI slots for expansion cards, and there are some PCI-based wireless network cards. Some PCI cards have external antennas; others have jacks for higher-powered antennas. Some other manufacturers, such as Proxim, use the PCI card to hold a PC Card; this combination often results in strange driver problems as one set of software tries to cope with the card holder and another with the card itself.

• Mini-PCI cards. Certain laptop models, such as the Dell TrueMobile 1150, take an even smaller internal expansion card called a mini-PCI card. Most mini-PCI slots also have an internal antenna connection.

• Custom slots. Recent models of Compaq laptops have a special MultiPort slot that takes wireless network adapters. Since 1999, Apple has built into every model of the Macintosh internal connectors that accept a modifi ed PC Card, which Apple calls an AirPort card. And at least one fi rm, the Xircom division of Intel, makes a snap-in wireless adapter for the Springboard expansion slot on the back of certain Palm OS-based devices from Handspring.

NOTEA card that fi ts into an AirPort or MultiPort connector hooks to an antenna built into the case of the laptop or desktop computer itself. Because these antennas can typically be both longer and more integrally designed, they offer signifi cantly better range and reception. However, Apple’s Titanium PowerBook G4 has a case that is so electromagnetically shielded that it halves the wireless network range of this computer. To work around this limitation, some users rely on either a PC Card or a USB adapter that moves the antenna outside the case. Newer revisions of the Titanium have improved the wireless network range of an internal AirPort card, but it’s still poor.

• CompactFlash card. Many handhelds and digital appliances, such as PocketPC organizers, cameras, and MP3 players, use CompactFlash cards for storage. Several manufacturers should soon ship a variety of CompactFlash wireless adapters, although not all equipment with CompactFlash slots have the built-in software available to handle wireless networking. It’s more likely that future devices will start to take advantage of CompactFlash-based wireless network cards.

• Secure Digital IO card. Several handhelds, including organizers from Palm, accept tiny Secure Digital IO (SDIO) cards.


External Wireless AdaptersSome computers, such as iMacs and Power Macs that predate the release of Apple’s AirPort hardware, must use an external wireless adapter because they simply can’t accept one of the internal wireless cards. External wireless adapters can be useful for some modern machines as well, if, for instance, a computer’s PC Card slots are full, or the computer requires multiple wireless cards. Although locating an external adapter was a major obstacle in the past, it’s now relatively easy to fi nd one that works with your computer. As with some PCI cards, external wireless adapters sometimes work with a PC Card from the same manufacturer.

NOTEYou can install a wireless PCI adapter in some older Power Macs, but the software to support them may not exist.

• USB adapters. The USB port, which is often used for plugging in keyboards, mice, and printers, can also accept external wireless adapters. Don’t worry about performance degradation, since standard USB 1.1 runs at 12 Mbps, slightly faster than the 11 Mbps maximum throughput of 802.11b networks.

• Ethernet adapters. Some newer home electronics gear, such as the ReplayTV digital video recorder and Microsoft’s XBox, and some older computers, has only an Ethernet port or can’t accept the software drivers to handle wireless networks. In those cases, you want a wireless adapter that plugs directly into the device’s Ethernet port. Some Ethernet adapters can attach to a network of wired Ethernet devices and transfer all of their traffi c to and from a wireless network via the access point; one such adapter can take up to 30 computers or other pieces of equipment and connect them to an access point.

Chapter 4 | Connecting Your Computer 87

Confi guring the Windows XP Client SoftwareNow that your hardware and network settings are properly set up, it’s time to confi gure the wireless network client software that manages settings specifi c to the wireless network. This wireless client software is built into Windows XP; if you’re using an earlier version of Windows, you must use the client software that came with your wireless network adapter.

NOTEIf you aren’t running Windows XP, or choose not to use its built-in client for some reason, fl ip forward a few pages for instructions on confi guring the Linksys and Orinoco client software, plus some advice on what’s necessary for other client software. In general, we recommend using Windows XP’s client software if possible—it’s easier, more integrated with Windows, and will likely take over from all the others as Windows XP becomes ever more prevalent. Some Wi-Fi network adapters can’t yet take advantage of the Windows XP client software because the hardware drivers haven’t been upgraded to handle the interaction.

Let’s look at how you enable and confi gure the Windows XP wireless network client software.

NOTEYou may want to access multiple wireless networks—one at home, another at work, and a third while at a conference—or have access to several networks in one place. Because of this, the Windows XP client software lets you confi gure details for several networks and stack them in the order in which you want to connect if more than one is available. The top of the client shows available networks, while the bottom shows networks that you’ve confi gured.

1. To enable Windows XP’s built-in wireless client software, open My Net work Places from the Desktop.

2. Click View Network Connections.

3. Right-click the Wireless Network Connection item under LAN or High-Speed Internet. In the pop-up menu, if you see the option Use Windows to Confi gure My Wireless Network Settings and it is unchecked, choose it. (If the option isn’t showing, just continue on.)


4. Right-click Wireless Network Connection again, and choose View Available Wireless Networks from the pop-up menu.

5. Click the Advanced button (Figure 4.7).

6. Click the Add button beneath Preferred Networks to bring up the confi guration dialog for a new Wi-Fi network (Figure 4.8).

7. Enter the network’s name or SSID.

8. If you’re using WEP, check Data Encryption and enter the key. From the Key Format menu, choose ASCII characters if you’re using a passphrase, or hexadecimal if you’re using the more routine form. Choose the Key length from the pop-up menu.

NOTEThe menu says 13 characters for 104/128-bit keys, when it really means 13 hexadecimal bytes, or 26 hexadecimal digits.

9. Click Connect.

That’s it! Repeat as necessary for any other networks to which you want to connect. You can change the network to which you’re connected in the Wireless Network Connection Properties dialog’s Wireless Networks tab (Figure 4.8). Networks about which you’ve entered details (if they’re closed) or from which the adapter can receive a signal appear in the Available Networks list. Preferred Networks contains a list of any network connections you’ve set up as noted earlier.

There is another useful difference between the Available Networks and Preferred Networks lists. Even though it appears that selecting a network

Figure 4.7Windows XP’s

wireless network client software.


from Available Networks and clicking Confi gure gives you access to security settings, you cannot make changes from that window. You can modify your security settings and other details about a network only by selecting a network in Preferred Networks and clicking the Properties button to open the Properties dialog for that network.

Figure 4.8Wireless Network

Connection’s Properties.


Apple’s AirPort software expects that you’re using an AirPort Base Station as your access point. When it asks you to enter the password for the AirPort Base Station, you type in a password instead of an actual WEP key. But if you’re using an AirPort-equipped Macintosh with any other kind of access point, you must instead type in either 10 or 26 hexadecimal characters.

Entering the hexadecimal WEP key works fi ne with the latest versions of the AirPort software for Mac OS 9 and Mac OS X, when you’re entering the WEP key in response to being prompted for it. Mac OS 9 accepts a hexadecimal key without a problem.

However, Mac OS X 10.2 Jaguar’s prompt offers choices for what you’re entering in a pop-up menu (Figure 4.18). Choosing Password lets you enter an AirPort-style password. The other four choices correspond to the key length (40 or 128 bits) and the encoding (ASCII or hexadecimal). Choose the appropriate ASCII option only when your WEP access is via a passphrase. (These WEP passphrases are con-

verted into actual WEP keys, but not in the same way that Apple turns AirPort passwords into WEP keys.)

With earlier versions of the AirPort software, and in the password fi eld of the Network pref-erence panel in Mac OS X, entering the WEP key by itself won’t work. The trick? Enter a dollar sign ($) before the hexadecimal WEP key, and all will be well. The dollar sign tells the AirPort software to send the exact hexa-decimal key to the access point rather than interpreting it as a password to send to the AirPort Base Station.

To enter a WEP-style passphrase in early versions of the AirPort software or in Mac OS X’s Network preference panel, enclose it in straight double quotation marks.

We’ve found that these WEP passphrases aren’t always compatible with one another, and we recommend using actual hexadecimal WEP keys instead of passphrases whenever possible when setting up access points other than the AirPort Base Station.

Entering WEP Keys on a Mac

Figure 4.18Selection options for passwords in Mac OS X 10.2

and later.


Bridging Wireless NetworksOnce you’ve been bitten by the wireless networking bug, it’s all too easy to keep adding machines and expanding your network until suddenly you come up against a brick wall, perhaps literally. Your next expansion is stymied because some client computers cannot reach your single access point.

It’s common for a larger house or offi ce to lack an ideal place where a single access point can serve all the client computers. As we note earlier in this chapter,

Chapter 5 | Building Your Wireless Network 153

in the “Multiple Access Points” sidebar, adding an access point can solve the problem, but the access points typically have to be connected via Ethernet cables, in essence forming a wired backbone for your wireless networks.

Cheap though it is, cable may not be your best option because of distance or physical barriers. Instead, a variety of inexpensive devices let you bridge isolated access points wirelessly, retaining (and indeed enhancing) the advantage of wireless networking without requiring a massive investment of time, drill bits, or installation money.

The concept behind wireless bridging is that you connect a single access point to an Internet connection, which almost always involves an Ethernet or telephone cable. Then you install a second access point to add coverage to an area unreachable by the fi rst. The second access point should itself be located where a wireless adapter can still reach the fi rst access point.

The magic comes in confi guring the access points (or additional hardware connected to the access points) so traffi c from the second access point’s wireless client computers passes through the second access point, and is then bridged over to the fi rst access point and out to the Internet.

Bridges are a great solution for a few common situations, such as expanding an offi ce network into multiple rooms, fl oors, or buildings; hooking up a larger network across a home; or bypassing an obstacle that blocks the wireless signal between two areas.

In effect, a bridge allows you to bypass even more of the physical limitations of the world, and send your wireless network into larger and more far-fl ung connections.

Picking Bridge HardwareCurrent inexpensive equipment for bridging wireless networks works in one of three modes: a pair or more of bridges that don’t work as access points at all, but bridge network traffi c between or among networks they’re wired into; a bridge that can connect only to an access point made by the same company; and a bridge that can connect to any access point, but limits the number of machines it can bridge.

NOTELinksys makes devices, the WAP11 and WET11, that work in all three modes. A few other companies also sell very similar or actually identical equipment licensed from the same manufacturers (Figure 5.21).Figure 5.21).Figure 5.21


Deciding which of these three alternatives makes the most sense for your situation depends on the distance the bridge must traverse and the nature of your network.

Bridging in Pairs or MultiplesBridging in pairs or multiples is the most expensive option, as it requires at least two bridge devices that do nothing but talk to each other (Figure 5.22). The Linksys WAP11, for instance, has point-to-point and point-to-multipoint options that let you connect two or more networks.

NOTEIn multipoint mode, one bridge receives and relays traffi c from multiple other bridges, which are in point-to-point mode. This bridge also relays traffi c from devices connected to it via its wired port.

The advantage of the WAP11 is that you can place it far from your actual offi ce for better line of sight. Many companies and individuals using the WAP11 run an Ethernet cable (which carries power over Ethernet as well) up to the roof, and then use a waterproof container to hold the WAP11. With an attached antenna, the WAP11 could easily bridge a wireless network to another WAP11 miles away.

NOTEWe talk about long-range connections in Chapter 8, Going the Distance.

The WAP11 costs as little as $100 at this writing, so you could install a simple point-to-point network for just $200 and a couple of Ethernet cables.

Figure 5.21Linksys WET11 and

Linksys WAP11.

Chapter 5 | Building Your Wireless Network 155

NOTEThe WAP11 and similar bridges are protocol bridges: that is, they can carry any traffi c that uses one of several protocols they support. The WAP11 handles TCP/IP, IPX, and NetBEUI, but keep in mind that you can’t run AppleTalk over the connection.

Bridging to an Identical Access PointThere’s a less-expensive, but otherwise similar option to using pairs or multiples. Instead of using a pair of bridges, you set up a bridge that connects wirelessly to a central access point (Figure 5.23). The Linksys WAP11 is the hero here again, since it offers a client-adapter mode in which one or more devices connected over Ethernet to the WAP11 can be bridged to another WAP11 that’s working as an access point.

Figure 5.22Point-to-point and

point-to-multipoint bridging.

Internet

Point-to-multipoint bridge.

Point-to-point bridge.


NOTEA variety of similar gear, including some D-Link hardware, can also work in this mode with Linksys equipment. However, since the makers don’t guarantee compatibility, future versions might not work at all together. We recommend sticking with equipment from the manufacturer if you plan to bridge networks.

In client-adapter mode, the WAP11 bridges the same protocols discussed previously (TCP/IP, IPX, and NetBEUI). The disadvantage of this solution is that the WAP11 is a bare bones access point, with virtually no gateway features, so you may need to buy a gateway to supplement the WAP11 that’s acting as the access point.

Figure 5.23Bridging to an

access point.

Internet

Chapter 6 | Wireless Security 169

Preventing Access to Your NetworkWith just a few steps you can discourage casual browsers of your network. These steps are just the fi rst line of defense, but they may be suffi cient for home users.

You have three main tools to discourage network access: closing your network, employing WEP encryption, and limiting access to specifi c wireless network adapters.

Closing Your NetworkWhen you run a wireless network, you start with a fundamental choice: whether your network is open or closed. This choice is often obscured by marketing and complexity. Unfortunately, closing your network sounds better than the reality behind it.

In the case of an open network, your access point constantly broadcasts the name of your network. That makes it easy for someone to see your network and connect to it.

Most access points offer a simple option that lets you hide your network name. Some call the option a “closed network,” others “disable broadcast name.” No matter what the terminology, a closed network’s name doesn’t appear in the list of available networks in client software (Figure 6.1).

The Wireless Networking Starter Kit 170

Don’t be lulled into a sense of false complacency. Although a closed network offers protection from the most casual observer, all of the network snooping software discussed later in this chapter in “Know Your Enemy” can retrieve the network name with no effort.

In short, if you don’t want people connecting to your network, there’s nothing wrong with making it a closed network, but the only people you’re keeping out are those who almost certainly weren’t a security risk anyway.

That said, closing your network is useful if you don’t want to share your Internet connection with passers-by, since unless someone has gone to the trouble of installing and understanding a snooping program, they won’t be able to see your closed network.

WEP EncryptionThe developers of 802.11b intended WEP (Wired Equivalent Privacy) to do precisely what the name itself says: offer an equivalent level of privacy to what could be found on a standard wired network. To compromise a wired network, an attacker generally needs to break in to a room and install a network-sniffi ng program that watches traffi c traveling over the wire. WEP was designed to act merely as a locked door, to keep intruders from penetrating to the wireless network traffi c itself; other measures were supposed to bolster this initial line of defense. WEP basically encrypts all the data that fl ows over a wireless network, preventing attackers from eavesdropping on network traffi c (Figure 6.2).

Unfortunately, even this relatively minimal protection was crippled because of several brain-dead decisions made on the cryptographic front, and because some options were built-in but never enabled. Also, even though WEP still offers some level of protection, most people don’t turn WEP on because it’s a pain to use.

Figure 6.1Closing your

network prevents casual users from

seeing the network name.

Internet

billnet

billnet

But with a little effort, a snooper can determine

the network’s name.


NOTEMost systems that require the user to type long sequences of random characters also use something called a checksum, which is a calculation performed on the string of text. When you type a requested string, the system double checks your entry by calculating the entry’s checksum; if the two checksums don’t match, the system tells you that you’re in error. Why WEP doesn’t have this as part of its protocol, we have no idea. We can imagine only that the designers never saw millions of users typing in WEP keys.

WEP works by using a “shared secret”: an encryption key (up to four per network) shared by everyone on the network. Your wireless network adapter uses the encryption key to encode all traffi c before it leaves your computer. Then, when the data arrives, the access point uses the key to decode it into its original form.

Users must enter the WEP key manually (and tediously) on every computer that wants to be part of a WEP-protected network. Worse, the key is often expressed in the base-16 hexadecimal numbering system in which the letters A through F represent 10 to 15 as a single digit. Most users haven’t the slightest idea of how to deal with hex (reasonably enough—that’s what computers are for!). If you combine user confusion with the tedium of inventing (on the access point) and entering strings of hexadecimal numbers, you can see why WEP is annoying to use.

NOTEKudos to Microsoft for how it set up its Wireless Base Station: the default is to walk the user through adding a 128-bit WEP key, and to store the backup on a fl oppy disk.

You enable WEP in an access point by inventing a sequence of 10 or 26 hexadecimal digits (corresponding to a 40/56/64-key or a 104/128-bit key). Luckily, some access points have a feature in which you type a passphrase and

Figure 6.2Turning on WEP

prevents attackers eavesdropping on

network traffi c.

Attacker can’t understand WEP-encrypted traffi c without

the appropriate WEP key.


then the access point translates that into hexadecimal digits for you. If your clients and access point can support the longer WEP key, use it, as longer is better, although only slightly better.

TIPSee Chapters 4, Connecting Your Computer, and 5, Connecting Your Computer, and 5, Connecting Your Computer Building Your Wireless Network, for tips on entering WEP keys in both client software and access points. Note especially the tips for dealing with Apple AirPort encryption when working in a network with AirPort- and non-AirPort-equipped computers and devices.

How WEP Is BrokenAside from the usability problems, how is WEP broken from a security standpoint? Here’s a quick rundown of WEP’s major fl aws:

• Shared secret. Every computer on a WEP-protected wireless network needs a set of one to four keys that users must typically type and which can sometimes be read as plain text. The complexity of managing keys makes it easy for an attacker to come by a key through social engineering (asking someone for the key), carelessness (the key written on a piece of paper), or disgruntlement (a fi red employee). Most keys are never changed after the fi rst time they’re entered.

• Initialization vector problems. The initialization vector is a 24-bit portion of a 64- or 128-bit WEP key that is supposed to help increase the number of possible different keys generated from the remaining bits by varying the keys over time. Unfortunately, use of the initialization vector is optional, so many manufacturers don’t use it at all, and poorly implemented, so even when they do use the initialization vector in WEP keys, they don’t vary it in random, complex ways. Attacks using the initialization vector include watching for key reuse, which should happen after only extremely long periods of time (if ever), but in high-traffi c situations occur after just a few hours.

TIPEver wondered why we talk about WEP keys as being 40/56/64-bit and 104/128-bit instead of just 64-bit and 128-bit? Some companies and discussions exclude or incorrectly account for the 24-bit initialization vector as part of the overall key length.

• RC4 fl aws. The RC4 encryption algorithm as implemented in WEP can easily be broken by passively intercepting between about 1,000,000 and 6,000,000 packets of data. On a busy network, that much data could


pass through an access point in a matter of minutes. Networks that use a simple WEP passphrase instead of a pure hexadecimal key are easier to compromise, while breaking the RC4 encryption on networks that use 128-bit hexadecimal WEP keys generally takes a bit longer, though not enough to provide real security.

You may think that these problems are obscure, especially the latter two, but an attacker needs no specialized knowledge to exploit them; automated tools perform all the hard work. See “Know Your Enemy” later in this chapter.

TIPFor more about wireless encryption problems and solutions, see Glenn’s regularly updated security status report at http://80211b.weblogger.com/weak.defense.html.

Despite these faults with WEP, a user with relatively little traffi c on her network and/or with little to worry about in terms of interception (passwords but not proprietary data) can generally rely on WEP as her only means of protecting the network. Someone would have to be very determined, and potentially scan a network for several days or even weeks, to assemble the pieces necessary to break a WEP key.

The Future of WEPThe IEEE’s 802.11i committee has been working for years to replace WEP with a forward-thinking, yet backward-compatible solution that would return WEP to its rightful role as a fi rst line of defense. Ideally, this solution would also provide a reliable way for smaller networks to secure their traffi c completely.

The latest proposal is scheduled for ratifi cation in mid-2003, although equipment featuring the technology may appear before then. The new standard is called TKIP or Temporal Key Integrity Protocol. The committee’s meeting minutes indicate overwhelming support for making sure TKIP works with older equipment through fi rmware upgrades.

NOTEOriginally, TKIP was called WEP2, but after WEP’s various fl aws were exposed, the committee decided to opt for an entirely new name.

It’s possible that even more sophisticated solutions will become part of several networking protocols. The barrier to more sophisticated solutions is that the required algorithms involve dedicated chips to handle the cryptographic computation. The cost of chips continually drops, so we will probably see these more sophisticated security solutions in the future.


Access Control by Network AdapterThere’s one more way to restrict access to a network, and that’s by allowing only specifi c network adapters to connect (Figure 6.3). Like all Ethernet network adapters, Wi-Fi adapters are identifi ed by their MAC (Media Access Control) address, a unique serial number assigned to every network adapter.

However, as we noted back in Chapter 2, Networking Basics, MAC addresses are not immutable and can easily be spoofed. Many gateways and access points let you enter different MAC addresses to simplify connecting to ISPs that lock connections to a specifi c network adapter.

However, this fl exibility, combined with the fact that MAC addresses are sent in the clear even on WEP-enabled networks, means that a cracker can easily see MAC addresses in use, and then assign one of those addresses to his equipment. As with a closed network, then, restricting access by MAC address will keep honest people honest, but it won’t do squat against a determined intruder.

WEP’s problems center around its use of shared keys, which can be changed only manually. There’s a signifi cant improvement over WEP that works around this problem, but it cur-rently requires more expensive and proprietary hardware, client software, and even back-end network servers.

EAP (Extensible Authentication Protocol), PEAP (Protected EAP), and LEAP (Cisco’s version of EAP) all work by themselves or as part of a framework called 802.1x to secure keys on a network more fl exibly, rapidly, and individually than WEP.

These new fl avors of authentication enable each client to initiate a connection to an ac-cess point, negotiate its own individual key with a network-based authentication server (securely in various manners depending on the EAP type), and then rotate keys rapidly

enough to prevent any one key from being used for long enough to be broken.

802.1x acts as a general way to funnel these authentication protocols through the network; Microsoft built a version of 802.1x into Win-dows XP. The Wi-Fi Alliance’s new WPA (Wi-Fi Protected Access) puts 802.1x and EAP into all Wi-Fi certifi ed hardware start-ing in spring 2003, and makes it required by late 2003.

Since 802.1x can work over a local network or the Internet, we hope ISPs will add these kind of negotiated key rotation protocols so that home users and small offi ces could take advantage of this additional security without building full network systems.

For more on these systems, read the article about wireless authentication at: www.cisco.com/warp/public/784/packet/exclusive/apr02.html.

EAP, PEAP, LEAP, and 802.1x


Networks on the RoadThanks to the fact that more and more wireless hot spots and networks appear every day, it’s impossible to fi nd a single, up-to-date directory that contains a comprehensive listing of hot spots. You may fi nd wireless networks in unlikely and far-fl ung spots—Glenn received email from a reader of his 802.11b Networking News site about a fully “unwired” hotel in India shortly before we wrote this chapter—so it’s worth taking a few minutes before you leave to determine where you can fi nd wireless networks at your destination.

NOTEA “hot spot” is a location with a publicly available wireless network.

Hot Spot DirectoriesWe’ve found only two Web sites that attempt to track the many different hot spots across both the U.S. and the rest of the world. Visit them fi rst in any search for wireless networks at a travel destination.

• 802.11Hotspots.com (www.80211hotspots.com) lets you fi nd hot spots in cities that are known to have them—you can’t even search for a city that’s not listed. However, you can also list all the known hot spots in each state in the U.S., and in a small number of other countries. In our informal testing, 802.11Hotspots.com had more listings than its primary competitor, WiFinder, and we found its results somewhat easier to use because it shows many more results at a time, rather than forcing you to fl ip through page after page of results.

• WiFinder (www.wifi nder.com) provides a more fl exible search form that lets you search on location name (so you can search on “airport”, for instance, to fi nd all the hot spots in airports). Other search fi elds include Address (helpful when searching for a specifi c location in a large city) and ZIP code. WiFinder also lets you choose if you want to fi nd only commercial hot spots, only community networks, or both, and you can list all the hot spots for some of the major commercial and community networks.

Although they’re both useful, 802.11Hotspots.com and WiFinder don’t list all the available hot spots by any stretch of the imagination, so don’t assume that you’re out of luck if they come up empty for your destination.

TIPBoth of these hot spot directories accept submissions from users, so if you know about a publicly accessible hot spot, we encourage you to add it to both directories to help other wireless travelers.

Chapter 7 | Taking It on the Road 201

Free Wireless NetworksRemarkably, there are thousands of places where you can hop on a wireless network to access the Internet for free. There are no service guarantees, of course, and the speed of the connection can range from a trickle at the speed of a 56 Kbps dial-up to a Niagara Falls at the speed of multiple T-1s. But for a quick email check, a free network could be just the ticket.

All that’s necessary to access the Internet via one of these community networks is that you select the network name from your list of available signals. A few community networks redirect your fi rst Web browser request to a page that identifi es legitimate use of the network and asks you to agree to it before proceeding.

TIPIf a community network requires you to click through an acceptable use agreement before you are allowed to connect, you can’t check email until you launch a Web browser and agree to the acceptable use policy.

Community Wireless NetworksMany communities have small, or even large, collections of loosely aggregated open networks created by individuals in the community. These community networks provide isolated hot spots in most cities, and certain neighborhoods have nearly complete coverage. For instance, the Pioneer Courthouse Square area in downtown Portland, Oregon, has excellent wireless coverage and high-speed Internet access thanks to nearby businesses contributing access through their Internet connections.

Although there’s no comprehensive way to fi nd an up-to-date list of all of these hot spots nationwide or worldwide, the best approach is to look for a wireless community network where you’re going, and then see if its site maintains a list of current hot spots. Personal Telco, a Portland-based grassroots organization devoted to community-based communications networks, publishes the most extensive list of wireless community networks at http://personaltelco.net/index.cgi/WirelessCommunities.

LibrariesMany communities have added (or plan to add) wireless Internet access to their public libraries. Adam’s wife, Tonya, serves on the Tompkins County Public Library Board of Trustees in Ithaca, New York, and as we write this book, she is helping the library consider what it would take to install and use the necessary access points for wireless Internet access.


NOTEWireless network access has many potential benefi ts in a library. Tonya hopes that wireless network access in the Tompkins County Public Library will take some of the pressure off the desktop Internet computers, allow patrons to carry laptop-based displays of the online catalog into the shelving areas, and provide more mobility and effi ciency to staff operations.

Adam and Glenn’s colleague Neil Bauman, the impresario behind and captain of Geek Cruises, lives within connection range of his local library’s wireless network. (Neil Bauman also has cable, DSL, and gigabit fi ber optic Internet connections thanks to his location in Palo Alto, California. We’re so jealous.)

Finding wireless Internet access in a public library when you’re on a trip may involve more effort than it’s worth, however, unless you know people in the community. Libraries typically don’t advertise their services widely, and they may impose login or other access restrictions. More important, you may not be able to fi nd a public library in the business districts of places you visit.

Colleges and UniversitiesIt’s a pretty good bet that most colleges and universities provide wireless Internet access at this point. If you’re attending a conference held at (or near) a university, it’s worth checking if it offers public access. Unfortunately for visitors and travelers, many colleges and universities, such as Cornell University and the University of Washington, use centralized authentication servers to restrict their wireless networks to students, faculty, and staff, making it diffi cult to arrange access for a visitor.

Although primary schools are less likely to have wireless networks installed, they’re also less likely to restrict access to them. If you end up at a meeting in a school conference room, open your laptop and see if you can connect to a wireless network.

Isolated Hot SpotsThe low cost of broadband Internet connections and the ease of setting up a wireless network has resulted in many public shops providing wireless Internet access as a way of enticing customers to come and spend time (and sample the wares, of course). Over the years, we’ve found a number of one-off hot spots that offer free service. For instance, the Dana Street Roasting Company in Mountain View, California, has free wireless access because a customer who wanted to be able to surf the Internet while he drank his lattes paid for it (www.live.com/danastreet/).www.live.com/danastreet/).www.live.com/danastreet/


These isolated hot spots may never show up in directories, so the only way to fi nd them ahead of time is to search in Google (www.google.com). For example, to fi nd wireless networks in Rochester, New York, you might search on terms like “wireless Internet access Rochester”. Sometimes you may just have to wait until you arrive at your destination, fi nd a likely location (coffeehouses are your best bet), and ask. Our friend and colleague Jeff Carlson found a coffee shop in his former town of Renton, Washington, that offers free wireless Internet access, but only if you ask someone to turn the network on. Why? It doesn’t want people to park outside and use the network without buying coffee.

Conferences and Trade ShowsAt many conferences and trade shows, particularly those with a technical bent, the conference organizers may set up an area where you can access the Internet wirelessly for free. The only downside is that these areas are often crowded, making the Internet access somewhat poky at times and making it thoroughly diffi cult to fi nd a chair in which to sit.

TIPIt’s always worth checking for nearby ad hoc wireless networks when you’re at a conference hotel. Since most hotels that offer high-speed Internet access charge by the day, if someone decides to pay for the connection, he may also decide to run a software access point and make the Internet access available to other wireless users within range. We once saw a “Send beer to room 1471 for password” network at Macworld Expo—meaning if you want the WEP key, send beer to that person’s room. Unfortunately, we were receiving the wireless signal from a nearby hotel, so didn’t know where to send the beer!

For-Fee Commercial Wireless NetworksFree wireless networks are great, but sometimes you get what you pay for. Free networks seldom offer formal tech support if you have trouble connecting, they don’t guarantee a certain level of Internet bandwidth (such as a 1.544 Mbps T-1 line that a business would typically offer), and there’s no assurance that a free network will even be accessible from one day to the next. Plus, if you need to use a VPN (virtual private network) to connect back to your offi ce, that may not be possible through a free network if it relies on an incompatible NAT (Network Address Translation) gateway.

It’s not diffi cult to offer tech support, guarantee a certain throughput, and provide overall reliability, but it is expensive. Businesses that provide wireless Internet access generally have charges ranging from about $4 to $12 per hour, from $5 to $10 per day, or fl at rates from $25 to $75 per month, all depending on the level of usage.


It’s tempting to try to sign up with only one of the commercial wireless providers, but that works only if you always travel in a very specifi c area that a specifi c provider covers. For the most part, these commercial networks offer a patchwork of wireless access in different kinds of venues, so if wireless Internet access is extremely important to you, you may have to sign up with multiple wireless providers. An alternative is an aggregator like Boingo Wireless (see “Roaming Aggregators” later), which aims to cut through the confusing multiplicity of wireless network providers and sell you a single account that works across multiple networks.

Connecting to the Captive PortalIf you’ve used a normal wireless network, you may wonder how these commercial networks force you to pay before you can connect. The fi rst part of the connection process works as you’d expect: you power up your machine and select the network from the list of available networks (or your machine might have selected it automatically). Your computer associates with the access point, and the access point assigns you a DHCP address. But you’re not on yet.

Then you must sign in by way of a captive portal. To do this, launch a Web browser and try to visit any page. The captive portal software intercepts your request and redirects it to a login page, where you enter your account information, credit an account, or provide credit card details for pay-as-you-go or per-day access.

TIPAs with community networks that use captive portal software to make you click through an acceptable use agreement, you can’t check email or use any other Internet software until you’ve logged in via the captive portal using your Web browser.

Wireless ISPsWireless ISPs, known commonly as WISPs or wISPs (an irritating capitalization style), exist all over the world, offering access for a fee to their wireless networks. Only a few offer more than a handful of access points, and most specialize in a certain kind of venue, like hotels or coffee shops.

The larger WISP networks in the U.S. and Canada currently include:

• T-Mobile HotSpot (T-Mobile HotSpot (T-Mobile HotSpot http://t-mobile.com/hotspot/). T-Mobile USA, a division of Deutsche Telekom and one of the main cellular telephone service companies in the U.S., bought the assets of the bankrupt MobileStar service in early 2002. In mid-2002, it relaunched the MobileStar service


under the T-Mobile name as a Starbucks partner in over 1200 locations, with plans for 2000 locations by 2003. In October 2002, it announced a plan with Borders to put hot spots into all 400 Borders bookstores by mid-2003, and 100 airport club lounges by late 2003. (See “Airports,” “Starbucks,” and “Borders,” later.) T-Mobile has a limited pay-as-you-go service, as well as monthly service plans.

• Wayport (Wayport (Wayport www.wayport.com). The granddaddy of wireless ISPs, Wayport has several hundred hot spots, mostly in hotels. Wayport also provides wireless access in a few airports, such as Seattle-Tacoma and Austin. Wayport typically offers a day rate and a monthly subscription rate.

• Surf and Sip (www.surfandsip.com). Surf and Sip is focused in the San Francisco Bay Area with several dozen hot spots, but the company has outposts all over the country. Surf and Sip offers hourly pay-as-you-go access, prepaid cards, and monthly service plans. Surf and Sip also sells a hot spot box that lets any retail business offer wireless Internet access.

• Concourse Communications Group (www.concoursecommunications.com). Although Concourse currently offers service only at the Minneapolis-St. Paul airport (in most terminals), it has the contract for Detroit and the three airports near New York City (JFK, LaGuardia, and Newark). Concourse relies on iPass, a service aggregator, to handle billing, and resells access to other networks, although none we know of are tied in yet.

• FatPort (FatPort (FatPort www.fatport.com). This Vancouver, British Columbia, fi rm has several outlets in the Vancouver area, and offers pay-as-you-go service, prepaid cards, and subscription plans. Like Surf and Sip, FatPort sells a plug-and-play hot-spot system for retail businesses that want to offer wireless Internet access without much fuss.

• Airpath Wireless (www.airpath.com). Airpath has a random assortment of hot spots around the U.S.

• SkyLink Internet Plus (www.skylink.ca). SkyLink offers wireless Internet access at two dozen hotels across Canada on an hourly rate or with a monthly subscription.

Many wireless ISPs also allow members of network aggregators to use their networks while using existing aggregator accounts (fl ip ahead a few pages to read the “Roaming Aggregators” section).


AirportsIn the world after the terrorist attacks of September 11, 2001, people who still travel extensively fi nd themselves spending many more hours than before in airports: you arrive early and if passing through security takes only a short time, you end up with nearly two hours on your hands. Plus, some connection times are longer, so you might have a multi-hour layover between fl ights. Even if you fl y only a few times a year, these extra hours add up.

It’s a natural match, therefore, to provide wireless Internet access in airports, whether in special hot spot locations or cafés, or throughout entire terminals. Unfortunately, the wireless Internet service provider market is littered with bankruptcies, and many of those bankrupt fi rms had made arrangements with airport authorities to install wireless service. These broken deals, along with early poor revenue fi gures from airports that actually did install wireless networks, have made some airport authorities wary, and the entire industry is moving slowly.

Despite the obstacles, the demand for wireless Internet access is just too high from business travelers, and there are too many opportunities to offer this

If you’re interested in launching a hot spot service from your home, business, or commu-nity center, you fi rst have to choose whether or not to charge for service. If you want to go the free route, check out http://nocat.net, www.bawug.org, and www.personaltelco.net, all of which have excellent advice and links. We also recommend Rob Flickenger’s book, Building Wireless Community Networks.

If you want to charge a fee for access to your network but don’t want to fi gure out how to put all the pieces together (the hard parts are authentication and billing), we recommend that you look into various “in a box” offerings. They allow you to purchase preconfi gured hardware for $500 to $1000, set up your own broadband network connection, and then simply enter a

few settings to get going. You may have to pay for a business-grade Internet connection, as many ISPs charge a higher rate for bandwidth that you plan to resell.

The aggregator or network that sells you the system collects the fees paid by users and pays you a cut based on sessions, monthly usage, or other parameters it negotiates with you. At this writing, Surf and Sip, FatPort, and Boingo all offer “in a box” products; Boingo has partnered with a number of other wireless net-works, which makes them a good choice if you believe your clientele is likely to want wireless Internet access while traveling. Some hot spot systems support multiple networks, including Boingo, for the maximum fl exibility.

Want to Become a Hot Spot?


service to a captive audience. We expect that by late 2003 all major airports in the U.S. will have some Wi-Fi coverage, although coverage may be extremely limited in some situations.

Most of the airport networks are part of a larger network. For instance, Austin, Seattle-Tacoma, and San Jose are all served by Wayport (and thus available to Boingo subscribers, as well), and many American Airlines executive club lounges have T-Mobile HotSpot service. T-Mobile plans to expand its club service to 100 lounges owned by American, Delta, and United Airlines by late 2003.

NOTEIn several airports, Wayport also runs little slices of heaven called Laptop Lanes (www.wayport.com/laptoplaneLanes (www.wayport.com/laptoplaneLanes ( ), which they bought from an early www.wayport.com/laptoplane), which they bought from an early www.wayport.com/laptoplaneinto-and-then-out-of-it wireless ISP’s parent company. Laptop Lanes are tiny, self-contained offi ces, soundproofed and with telephones and wired high-speed Internet connections. You pay a fairly high hourly fee, but it’s quiet, calm, and private.

Here’s a list of airports that currently have some kind of wireless Internet access, either limited hot spot access or complete terminal coverage (we omitted the T-Mobile lounge listings because they require membership for entry, and the clubs are often in places where you can’t perch nearby):

• Austin, Texas (T-Mobile, http://locations.hotspot.t-mobile.com/page6a.asp; Wayport, www.wayport.com/airports)

• Boston, Massachusetts (Airpath, http://isps.net/Directory.aspx)http://isps.net/Directory.aspx)http://isps.net/Directory.aspx

• Chicago, Illinois (Airpath)

• Dallas, Texas (Airpath, Wayport)

• Dayton, Ohio (Airpath)

• Denver, Colorado (AT&T Wireless, www.attws.com/goport/)www.attws.com/goport/)www.attws.com/goport/

• Flint, Michigan (Airpath)

• Greensboro, North Carolina (Airpath)

• Los Angeles, California (Gate Escape, www.thegateescape.com)

• Louisville, Kentucky (T-Mobile)

• Miami, Florida (Airpath)

• Milwaukee, Wisconsin (Airpath)


• Minneapolis-St. Paul, Minnesota (Concourse Communications, www.concoursecommunications.com)

• Norfolk, Virginia (T-Mobile)

• Ottawa, Ontario (Nokia, no Web site for hot spots)

• San Jose, California (Wayport)

• Seattle-Tacoma, Washington (Wayport)

• Sioux Falls, South Dakota (T-Mobile)

• Tampa, Florida (Airpath)

• Toledo, Ohio (Airpath)

• Vancouver, British Columbia (Nokia, only the airport’s Web site has information: www.yvr.ca/guide/todo/internet_access.asp)

• Wichita, Kansas (Airpath)

Elsewhere in the world, you can fi nd wireless access in many airports, including Amsterdam’s Schiphol, parts of Heathrow in London, and a number of lounges in airports where Sweden’s SAS airline lands. It’s well worth searching Google before you leave to fi nd information about any wireless Internet access at your intermediate and destination airports.

HotelsHotels, recognizing the often-pressing needs of their guests to connect to the Internet (and perhaps admitting the ridiculous nature of the per-minute charges they apply even to local and toll-free telephone calls), increasingly offer some form of broadband Internet access in guest rooms.

If you want to help urge hotels to install wireless Internet access, make your wishes known by asking about it when you make a reservation. Also be sure to ask when you check in, and if the hotel offers working wireless Internet ac-cess, praise it. Also, fi ll out a comment card, either thanking the hotel for providing wire-

less Internet access or noting that you might be more likely to stay at the hotel (or chain) in the future if it had wireless access. This kind of direct feedback, even in small num-bers, sways decision-making at high levels of a company.

Encouraging Wireless Hotels


Hotels started by wiring each room, which works well, but is an expensive proposition and may require that you bring an Ethernet cable (some hotels provide the necessary cable as well). More recently, however, some hotels have partnered with a wireless Internet service provider, primarily Wayport, to offer in-room wireless Internet access in certain rooms, public areas, and meeting rooms.

Typically, hotels charge about $10 per day, with a day annoyingly defi ned as midnight to midnight. So, yes, if you stay for two nights and want continuous access to the Internet, you’re charged for three days: the day you arrived, the full day there, and the partial day that you leave.

The aggregator Boingo Wireless (see “Roaming Aggregators” later in this chapter) has tried to solve this pricing irritation with a monthly subscription fee that grants you access to hotel wireless service just like other hot spots. It’s unclear whether this will catch on, because even though it might bring more overall usage to a hotel, it might also reduce the hotel’s revenue, at least in the short-term.

Hotels are worried about the next generation of cell phones, which can access the Internet at decent speeds, ranging from about 10 Kbps to as much as 150 or 200 Kbps (see Chapter 10, The Future of Wireless, for more details). The business travelers most likely to use the room’s telephone and broadband Internet access are also likely to buy these not-yet-released cell phones, making it hard to justify the investment in wiring rooms and installing wireless access points.

StarbucksThe coffeehouse chain Starbucks will tell you again and again: it’s not an Internet café. Rather, Starbucks want you to bring your expensive laptop in and buy expensive drinks using its, well, slightly expensive network. Starbucks has over 3500 freestanding stores in the U.S., and it partnered fi rst with MobileStar, which went bankrupt, and then with T-Mobile to build high-quality, T-1–based, hot spots in its U.S. stores and elsewhere.

In mid-2002, Starbucks and T-Mobile announced full wireless Internet access in 1200 stores in a number of cities and metropolitan areas: Atlanta, Austin, Boston, Buffalo, Dallas, Denver, Fort Worth, Hartford, Houston, New York City metropolitan area, Newark, Philadelphia, Portland (Oregon), Rochester (New York), Sacramento, San Antonio, San Francisco Bay Area, Seattle, Southern California, and Tacoma (Washington). They’re also experimenting with a few stores in London and Berlin, with plans to add service gradually in Europe.


Whew! You can see the latest list at http://locations.hotspot.t-mobile.com/starbucks.htm. T-Mobile currently offers a regional plan that lets you use unlimited service within cities or metropolitan areas for $30 per month.

Starbucks and T-Mobile have said they would have over 2000 stores connected by early 2003. That’s close to the original plan that called for connecting about 70 percent of Starbucks stores based on population density and demographics of area business users. But given that Starbucks opens hundreds of new stores each year, it could conceivably top 3000 wireless-enabled stores by 2004.

BordersStarbucks isn’t the only large retail chain that’s gone wireless. Just as we were fi nishing writing this chapter, T-Mobile announced a partnership with Borders to install wireless hot spots in 400 Borders stores by mid-2003—that’s every Borders store in the U.S.

Borders told Glenn that it would start in California and bring service up over the course of about six months, although it wouldn’t make a formal announcement until all the stores were ready to go. Once Borders is fully connected, you can use the Borders Store Locator (www.bordersstores.com/locator/locator.jsp) to fi nd a Borders near you or near where you’re planning to travel.

Schlotzsky’s DeliAlthough Schlotzsky’s Deli has chosen to install free access and offer it in just a few locations in Texas and Georgia, it’s obviously part of an experiment for them in how people use wireless networks (www.cooldeli.com/wireless.html).www.cooldeli.com/wireless.html).www.cooldeli.com/wireless.html

Roaming AggregatorsAs we noted earlier, none of the commercial wireless networks are suffi ciently widespread yet to make it worthwhile for most travelers outside of certain corridors—say Seattle to San Jose—to pay monthly fees for unlimited or substantial access to a given network. Wayport and T-Mobile have the largest networks, but even they can’t offer connections everywhere you might want to travel.

Problems like this are opportunities for ambitious companies, and a few have stepped into the gap by partnering with multiple WISPs to aggregate the service. Most of these companies started by aggregating dial-up Internet access around the world for business travelers.

The attraction of working with an aggregator is that you pay only a single bill and have to remember only a single set of login information, all while seamlessly


using a variety of different WISPs. As a bonus, the aggregators typically offer client software that provides additional security for those of us who aren’t already using VPN software.

Boingo WirelessAlthough Boingo Wireless (www.boingo.com) is the newest aggregator on the block, it has developed the largest hot spot footprint by partnering with other providers. Boingo has fairly sensible fi xed charges, plus a nice front-end client for managing for-fee connections and wireless confi gurations (for any network, not just commercial ones).

As we write this book, Boingo has about 800 hot spots, some 400 of which are operated by Wayport, Boingo’s largest partner. Boingo has announced partnerships with several other companies, and the company’s founder, Sky Dayton (the same fellow who founded EarthLink), predicted 4000 hot spots by the end of the 2002. (By the time you read this, you can fi nd out if he was right!) Boingo also lists some community hot spots that are free, making a visit to its hot spot directory (www.boingo.com/search.html) especially worthwhile.www.boingo.com/search.html) especially worthwhile.www.boingo.com/search.html

Boingo prices its service by the day, with each day costing $8. It also offers an unlimited plan for $75 per month, or a $25 per month plan that includes 10 connections per month (plus $5 per connection for additional connections beyond 10).

Boingo has its own custom wireless network client software that includes a list of locations and a tool for storing WEP encryption keys. When you’re near a Boingo partner’s hot spot, the software can alert you, so that you can connect. You never have to use a gateway or captive portal page to log in.

The Boingo software includes a VPN (virtual private network) client that lets you tunnel all of your traffi c from your machine to Boingo’s network operation center before it’s decrypted and sent over the public Internet. (For more about VPNs, see Chapter 6, Wireless Security.)

Boingo also includes outbound email service through authenticated SMTP, which requires you to reconfi gure your email software temporarily with your Boingo account name and password. This service helps you avoid a whole category of outbound email problems, which we discuss in “Other Preparation,” later in this chapter.

Although Boingo’s software is currently available only for Windows, Boingo has repeatedly stated that it plans a Mac OS X client.


iPassiPass (www.ipass.com) started as a way to let companies give a roaming road warrior a single account that would allow her access to dial-up Internet service no matter where in the world she landed. With ISP partnerships around the globe, in over 150 countries and with 15,000 points of presence, iPass has met that mark. Dial-up Internet access from iPass costs up to about $18 per hour depending on the amount of service you buy, whether you’re a company or an individual, and whether you’re dialing a toll or toll-free number.

iPass’s wireless offerings are relatively recent, but iPass offers single-account access through partners in several countries for about $7 to $20 per 24-hour period. iPass partners with Wayport in the U.S., and it also handles billing for Concourse Communications.

iPass requires that users run special client software, which is available for Windows, Macintosh, and various handhelds. Unfortunately, iPass has not yet updated the Mac version for Mac OS X, and the current version cannot handle broadband or wireless connections.

GRIC CommunicationsGRIC (www.gric.com) offers similar services to iPass, though we were able to fi nd out only that they partner with Wayport for wireless Internet access. The company’s Web site notes 20,000 points of presence, but provides no information on cost or other details. GRIC also requires its own client software, available only for Windows.

Chapter 8 | Going the Distance 235

Antenna TypesWe’ve mentioned the three major types of long-range antennas—omnidirectional, yagi, and parabolic—in passing already, but we should say a few more words about them. Plus, we want to mention other types of antennas that can be useful.


TIPWith some antennas, such as parabolic and panel antennas, it’s important to mount them in the proper orientation to match the polarization from the remote antenna. If you’re not sure of the appropriate polarization ask your ISP, and when in doubt, guess at vertical.

Omnidirectional AntennasAs you can imagine from the name, an omnidirectional antenna—also called a vertical whip antenna—is primarily useful in a location where you want the signal to radiate out from the antenna in all directions. That’s not quite accurate, because an omnidirectional antenna is usually shaped like a vertical stick, so the signal radiates out to the sides in a circle, but doesn’t go up or down much, making it look sort of like a pancake (Figure 8.4).

For the most part, you use an omnidirectional antenna to create a point-to-multipoint connection—that is, when you want many connections made to your omnidirectional antenna. ISPs often use omnidirectional antennas on their towers to avoid installing a focused-beam antenna for each customer. Another good use for an omnidirectional antenna would be to provide wireless network access for a school or a college campus. The problem with omnidirectional antennas is that they work best in relatively short-range situations where everyone connecting is at roughly the same elevation as the antenna (since the beam doesn’t go up or down much).

TIPIf you’re mounting an omnidirectional antenna (or any other type of external antenna) outside where it could be struck by lightning, you’d be smart to install a lightning suppressor to protect your access point in the event of a strike. Adam chose not to add lightning suppression to his system because his parabolic antenna is mounted on the wall of his house, under the eaves. Adding a lightning suppressor decreases signal strength slightly.

You can also buy a low-power omnidirectional antenna for increasing the signal strength of a network indoors. In such an installation, you’d want to mount the omnidirectional antenna roughly in the center of the space in order to take advantage of its circular radiation pattern.

Because they’re not focusing the beam much, omnidirectional antennas max out at about 15 dBi of gain. They’re also cheap, easy to install, and durable.

Sector AntennasLike omnidirectional antennas, sector antennas are used in point-to-multipoint situations. Unlike omnidirectional antennas, however, sector antennas radiate


only in a specifi c direction, and they’re often combined to cover an area. Vendors of sector antennas always describe the spread of the antenna’s coverage, usually between 60 degrees and 180 degrees.

The advantage of using multiple sector antennas over an omnidirectional antenna is that you can tilt the sector antennas down to work around the elevation problem that omnidirectional antennas face. They also offer higher gains—as much as 22 dBi. They tend to look like thin boxes, sometimes without centers (Figure 8.5).

Sector antennas cost much more than omnidirectional antennas and since you may need several of them to cover a full 360 degrees, the cost increases even more. They’re worth investigating mainly for specifi c locations where an omnidirectional antenna won’t work well.

One caveat to that. You may see some low-power, less-expensive sector antennas sold for extending network range inside as well. The advantage they have over

Figure 8.4An omnidirectional

antenna.

Figure 8.5 A sector antenna.


omnidirectional antennas when put to this purpose is that you can mount one on a wall and take advantage of its coverage pattern to increase the signal strength in a single direction.

Panel or Patch AntennasPanel antennas are solid fl at panels used for focused point-to-point connections, much like yagi and parabolic antennas, which we discuss next. Panel antennas are inexpensive, feature good gain of up to 22 dBi, and can blend in better with their surroundings than large parabolic grid or dish antennas. They don’t look like much—just small fl at boxes (Figure 8.6).

On the downside, because panel antennas must be pointed at the remote antenna, they often can’t be mounted fl at on a wall. And if they can’t be mounted fl at on a wall, strong winds may move them or damage them.

For indoor use, low-power panel antennas often work fairly well, though you have to mount them so that they’re likely to cover the affected area.

Yagi AntennasIf omnidirectional antennas are easily visualized from their name, yagi antennas are just the opposite. From the outside, a yagi antenna looks like a thick plastic tube, and on the inside, it has a series of metal circles or bars that drop in size as they near the end of the antenna (Figure 8.7). A yagi antenna provides a fairly focused beam, along with at most about 21 dBi of gain, with 15 dBi being common. Because of the focused beam, you mount a yagi antenna pointing at the remote location.

TIPBecause of the way yagi antennas radiate, it’s often better to point a yagi antenna slightly to the right or left of the remote location. As with all directional antennas, test different directions before clamping it down.

Yagi antennas are popular because they provide decent gain in a small and unobtrusive package. If you’re mounting a yagi on your house, there’s little need

Figure 8.6A panel antenna.


to worry about paranoid neighbors assuming you’re spying on them. Although they’re not quite as unobtrusive as panel antennas, yagi antennas suffer much less from the force of the wind (although snow and ice build-up in the winter can interfere with the signal).

Parabolic AntennasA parabolic antenna is the most powerful you can buy, and it generally looks either like a curved wire grid or like a small satellite dish (Figure 8.8). The longer the distance you want to cover, the more likely you are to need a parabolic antenna. With a parabolic antenna, you can enjoy a focused beam and up to 27 dBi of gain. The main downside of a parabolic antenna is that it can be big—Adam’s 24 dBi parabolic antenna is 2-feet by 3-feet, and 27 dBi antennas are about 6 feet in diameter. Luckily, Adam’s wife Tonya thinks a large, white antenna mounted on the side of her house looks pretty slick. The fact that it brings in better Internet connectivity is also a huge plus. Some other spouses may not be so understanding.

Parabolic antennas are quite affordable and those having a grid don’t suffer from either wind load or snow build-up, making them the most appropriate for more extreme situations where high-gain is necessary.

TIPIf you’re unconcerned about the look of your antenna and you don’t want to mess around, a high-gain parabolic antenna is probably the safest type to buy.

Figure 8.7A yagi antenna.

Figure 8.8A parabolic

antenna.


Dipole AntennasAlthough dipole antennas are not useful for long-range networking (because they have a gain of only about 2.2 dB), they’re often added to access points to increase range indoors. Many access points with external dipole antennas have a pair of them, which can be used either for signal diversity, in which both signal diversity, in which both signal diversityantennas send and receive and combine their results (like stereo vision), or for a mode in which one antenna sends and the other receives (Figure 8.9).

NOTEDipole antennas are essentially the same as the rabbit ear antennas used for television reception years ago, except dipole antennas used on wireless networking gear are much smaller. They are smaller because 802.11b uses frequencies in the 2.4 GHz (or 2400 MHz) part of the radio spectrum, whereas television uses frequencies in the 100 MHz part of the spectrum. As the frequency increases, the size of the wavelength decreases, and thus the antenna size can also decrease.

The main utility of an access point with removable (not all are) dipole antennas is that it’s much easier to add a more powerful external antenna. Life is easier if you don’t have to drill holes in your access point or solder connections between your access point and external antenna.

Building Your Own AntennaNo book that talks about long-range wireless networking would be complete without mentioning that, yes, you can actually build an antenna for almost no money at all. The most popular type of antenna to build is the so-called “Pringles can” antenna, which is a yagi type.

TIPAlthough the Pringles potato chip can has proven popular for homebrew antennas, people have had better results from other types of cans, with a Nalley’s Big Chunk Beef Stew can taking the prize in Greg Rehm’s comparison at www.turnpoint.net/wireless/cantennahowto.html.

Figure 8.9Dipole antennas.

Chapter 10 | The Future of Wireless 299

Ultra Wideband (UWB)Radios work today in much the same way as Marconi’s fi rst successful radio, using a specifi c band of frequencies in the spectrum. Because of this technical reality, government agencies around the world have set down rules that govern who can use which parts of the spectrum, in what geographic areas they can


transmit, how much power they’re allowed to use, and for what purposes they can use it. These regulations govern individuals, private organizations, military branches, and government agencies.

Step back from that for a moment. A concept in information science called Shannon’s Law defi nes a so-far immutable set of ideas about the amount of information you can encode into a piece of bandwidth, which is, quite literally, the width of the radio frequency bands used for transmission, measured in Hertz, coupled with the size of the wavelength (higher frequencies equals more room to encode). Shannon’s Law says that the more bandwidth you use and/or the higher your broadcast power, the more information you can cram in. However, increasing broadcast power is a problem, because no one wants to be fried by walking in front of an antenna.

NOTE802.11a runs at a raw rate of 54 Mbps: it works in the 5 GHz band versus 802.11b’s 2.4 GHz band, and a higher frequency means the ability to encode more information per Hertz. 802.11g might eventually be able to squeeze up to 54 Mbps out of 2.4 GHz, but experts believe the 5 GHz band could play host to future protocols that offer far more throughput even than the proprietary 108 Mbps “turbo-mode” in some 802.11a cards.

Ultra Wideband (UWB) communication uses Shannon’s Law to stand the traditional spread-spectrum approach on its head, providing high data bandwidth while ignoring obstructions. Instead of broadcasting continuously on tiny bits of spectrum (from 1 to 22 megahertz for the standards we’ve discussed) while switching between many frequencies, a UWB transmitter broadcasts millions of tiny, picosecond-long (a picosecond is a trillionth of a second) pulses at very low power across enormous swaths of bandwidth: hundreds, or even thousands of megahertz. The receiver extracts the content of the transmission by decoding the rhythm of the pulses.

UWB advocates claim UWB can co-exist with all current uses, because existing equipment wouldn’t be able to detect the signals; the signals fall well below the threshold of current gear, and would seem like noise even within the thresholds. UWB can pass through practically any physical object because some of the frequencies it uses are extremely low, and it can penetrate almost anything (these are the kinds of frequencies used for communicating with submarines underwater). UWB equipment would co-exist with itself, too, as the odds would be very low that two devices would transmit simultaneously.

Since the receiver must determine only the rhythm of the pulses, rather than decode their waves in any way, UWB can use very low power, which is helpful

Chapter 10 | The Future of Wireless 301

from many different standpoints, not the least of which is laptop battery life. A fi nal advantage is that because the pulses happen so quickly, UWB is highly secure; much of the interest in UWB over the years has come from the military.

The downside of UWB is that although it’s been tested in labs, various regulatory bodies around the world, including the FCC, are dubious about allowing it to be used in the wild without a lot more research. UWB doubters and detractors worry that the transmissions could interfere with a wide variety of existing uses because of UWB’s approach of transmitting on wide swaths of spectrum simultaneously.

In 2002, the FCC took a baby step by approving a short-distance, low-power, narrow-band version of UWB that could give Bluetooth a run for its money, carrying 100 Mbps (or more) instead of Bluetooth’s 1 Mbps. More likely, UWB transceivers would simply replace the 2.4 GHz frequency-hopping Bluetooth transceivers, but the rest of the higher-level Bluetooth approach would remain the same.

If it proves workable, UWB’s potential is enormous. Imagine that, instead of a few hundred feet and 11 Mbps to 54 Mbps of data transfer with 802.11b and 802.11a, you could instead span 500 to 1000 feet and transmit data at a gigabit per second! Were this to happen, the IEEE would likely extend its wireless working group to apply Ethernet-like protocols on top of UWB as it has with so many other physical transport media. Once you have gigabit-per-second throughputs, there’s little reason for most local area networks to continue using wires at all.

UWB could also help home electronics makers by carrying high-bandwidth services like video and audio over short distances. Think about putting a solar-powered satellite TV dish on your roof with multiple televisions receiving the signal from the roof inside your house—and no wires whatsoever.

Don’t hold your breath waiting for UWB, but if it comes, it will come in a big way. For more information, visit the Ultra Wideband Working Group Web site at www.uwb.org.

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