Linux Makes Wi-Fi Happen in New York City

Going Signal Fishing

Wi-Fi range is low on purpose. It operates on a tiny wedge of unlicensed microwave frequencies divided into 14 channels between 2.412 and 2.484GHz. Here in the US, we use only 1–11. In Europe they use 1–13, except for France, where they use 10–13. Japan runs from 1–14. The default transmission power of most access points (also known as APs, WAPs and base stations) is 30mw, about one-tenth the power of a cell phone but on a higher frequency, where the energy attenuates more rapidly with distance through air and has trouble penetrating many objects, including tinted windows and leaves full of microwave-absorbing water.

Wi-Fi range tends to run less than the average cordless phone, which sports a more powerful signal. With such a handy service delivered by such a short-range signal, it's only natural to find the best signal where the population is both dense and conveniently arranged, such as New York City, where people live and work on top of one another.

I ran six wardriving sessions, which included nine taxi rides, nearly all in Manhattan. The last session ended with a highway ride to LaGuardia Airport through signal-free parts of Queens. Each session recorded basic data about every detected signal, including ESSID (Extended Service Set Identifier—the access point's name). On the nine rides, I logged a total of 1,548 open access points.

On city streets in Manhattan, I found there was nearly always an access point in range. And I'm sure the numbers above would have been much higher if I'd had an antenna outside each taxi instead of on my lap in the back seat. Although lots of commercial hot spots exist, the vast majority appear to belong to individuals. “Linksys” is the default ESSID for the company's popular inexpensive access points.

The willingness of individuals to share bandwidth is amazing. Although the number of wide-open APs was lower than the WEP numbers above suggest, because quite a few were password-protected, plenty of usable signals still were available. More than once I was able to pick up and send e-mail while a cab was stopped at a light.

The ideal way to go signal fishing with a Linux or BSD laptop is with Kismet, a wireless network sniffer so full-featured it even does neat stuff with GPS, precisely associating signals with locations [see page XX].

Fellow Travelers from behind a Linux Laptop

Kurt Starsinic, Guide to the Wireless Scene

The City Hall Park welcome screen shows nearby attractions.

Right before the trip, I mentioned in a SuitWatch newsletter that I'd be coming to New York to check out the Wi-Fi situation and that I could use some local help. The first reply came from Kurt Starsinic who quickly became my Wi-Fi docent for warwalking and wardriving through lower Manhattan. I hooked up with Kurt at Alt.Coffee on Avenue A across from Tompkins Square Park. Alt.Coffee is both a comfortably run-down coffee house and a reliquary for dead computers. Kaypros, ARCnet hubs, early-vintage PCs and other antiques are scattered on tables and piled up in corners—worth a visit.

As it happened, the APs for both Alt.Coffee and NYCwireless were down while we were there, but when we walked around Tompkins Square Park, we still found at least one home node with an open and usable connection. And yes, of course we used it.

Our next stop was City Hall Park where the NYCwireless signal is clear and strong. There I was able to sample NYCwireless' local fare while Kurt briefed me on technology issues and both of us waited for my old friend Stephen Lewis to show up.

Steve, who carries US and Dutch passports, is a European telco industry veteran who was highly curious about what was happening with Wi-Fi in his home town. Walking around Steve's old haunts in the Lower East Side, we were impressed by the density of Wi-Fi, from both public and private sources: Verizon public phones, McDonalds restaurants and Starbucks coffee shops, in addition to private homes.

The ability to get on the Web almost anywhere in an outdoor urban setting was especially impressive to Steve, a two-time Fulbright Scholar with a hearty appetite for information. As a result, he began to develop ambitious plans to carry the lessons of New York neighborhood Wi-Fi (including Linux technologies) to Bulgaria, where he has lived for much of the last decade.

One of the most interesting figures in the New York Wi-Fi movement is Drazen Pantic. A former mathematics professor at the University of Belgrade, Drazen ran the Internet service of B92, a radio station that was a thorn in the side of the Milosevic regime. After the station's transmitter was shut down mysteriously, Drazen made sure the station's news and information continued to come out on the station's Web site and through streams that were picked up and rebroadcast in the UK, Netherlands, the US, and, most significantly, Yugoslavia. Stations there picked up and rebroadcast the analog signals relayed by satellite from the Netherlands. As a result, B92 quickly became the primary source of news from, and about, Yugoslavia and the conflicts there. Hearing him tell the story of his life, it was clear that Drazen was a hero of several revolutions at once.

Drazen is also involved with, a Vienna-based group of free software hackers devoted to producing GPL'd freeware for real-time video processing, media streaming and other cool stuff. The coolest of Dyne's tools, Drazen explained, is HasciiCam, a neat little hack that captures video from a TV card, renders it into ASCII and outputs it in a variety of ways—as HTML with a refresh tag, as a live ASCII window or as a simple text file.

On the downstream side, Drazen is excited about both the Dyne:bolic Linux distro and MPEG4IP. Dyne:bolic is a multimedia-oriented distro that can run from a CD and recognize sound, video, TV, network cards and other peripherals. MPEG4IP is a streaming package that obviates the need to use proprietary streaming systems. Drazen says, “After downloading Dynebolic, you can burn a CD, boot in to Linux and stream high quality MPEG4.”

Drazen believes all these open-source efforts will finish liberating audio and video authoring, production and distribution from the corporate chokeholders that still hold our ambitions and imaginations in check. He sees Linux as the public OS platform and Wi-Fi as the public network commons. Together they'll support a new form of (literally) public TV and radio. Between Wi-Fi, HasciiCam, digital camcorders, cheap hardware, free software, Dyne:bolic and MPEG4IP, Drazen expects the threshold of reporting and broadcasting to drop about as far as it can go. When it gets there, watch out.


Doc Searls is Senior Editor of Linux Journal


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Re: Linux Makes Wi-Fi Happen in New York City

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Great article!