WiFi in Phoenix Arizona

Driving around the Valley of the Sun I almost always keep my WiFi sniffer running. Some call this hobby/sport "white-hat war-driving"; "war-driving" (the name is derived from the "war-dialing" that Matthew Broderick's character does in the movie "War Games"), and "white-hat" (I'm a nice guy and am not interested in hacking into someone else's computers). It's been an incredibly useful way for me to gauge the general acceptance of WiFi by Phoenicians and to get some interesting statistics on range and performance.

If you have any information on WiFi in the Phoenix area or are interested in doing some WiFi experiments, contact me at jon (at) jonadams.com. If you're a ham (amateur radio operator) who's interested in employing Wi-Fi for amateur radio links, you may want to check out our Yahoo! group at groups.yahoo.com/AI802 .


Phoenix commercial WiFi has begun to materialize, there's been a growing number of access points over the past year or so. There appear to be a number of Starbucks/T-Mobile, Circle-K/Surfhere, plenty of Wayports, etc. The usual suspects. There are a few "free" access points, and many, many MANY unintended "public" (if you can hear it on the street or sidewalk, it's public) access points...

Chris Tingom maintains a webpage at ArizonaReviews.com where he details many free (and otherwise) hotspots in the greater Phoenix area. Check it out!

I've been running an encrypted access point now and then as a range/connectivity experiment. It's a Linksys AP with about 20dBm transmit output running into a 15dBi omni antenna. With cable losses, I'm still about 2-3dB below the FCC limits. When it's up, I measure decent throughput at ranges up to about 400m, sometimes more. If it's installed at a location with little foliage (and at least 10m above ground)it seems to be able to deliver about 600m or so.


Linksys WPC11 Client Card

Airlink101 AWLL3026 USB Dongle


In order to get a consistent measure of the 2.4 GHz 802.11b WiFi adoptance rate, I was driving a canonical route at least once a month, winding through a multiplicity of neighborhoods from lower-, middle- and upper-class residential, to industrial, entertainment (hotel, restaurant, etc.). To find this data, representing the growth of Wi-Fi in Phoenix from January of 2002 to the present (with some significant data holes), go here.

The route is about 47 miles in length, and with my setup in the truck I can easily hear 100 meters either side of the route. The computer listens to the 11 channels in the unlicensed, 2.4GHz spectrum, and if someone's WiFi access point beacons out its SSID (Service Set IDentification) during the time I'm in range, the NetStumbler software logs that beacon transmission. It is possible to set up most APs to not beacon, but most people don't.

The following represents the sum total of every 2.4GHz 802.11b node that I see over the period of a month when I have the sniffer running during driving. Sometimes (most times), I don't make it out of Phoenix, but every once in a while there's a trip to somewhere else in Arizona, or New Mexico, California, or Nevada.
December 2005
November 2005
October 2005
September 2005

August 2005

July 2005
June 2005
May 2005
April 2005
March 2005
February 2005
January 2005
December 2004
November 2004
October 2004
September 2004

There's also a few interesting long-haul WiFi links. Most people think of WiFi as having ranges of a few hundred feet at most, but there are systems here that have link distances of many miles. In addition, WiFi (with encryption) is being used to move live video data from cameras located at specific intersections. Intersections include Tatum and Lincoln and Tatum and Mcdonald in Paradise Valley, and several intersections along Grand Blvd (US60) through Glendale. See SmartSight Networks for details on the technology. (NOTE: These stations seem to be physically there, but either disconnected or without beacons as of the early part of 2004.)

If you have any information on WiFi in the Phoenix area or are interested in doing some WiFi experiments, contact me at jon (at) jonadams.com.

The mysterious "cskphx08" (Channel 1) with its several square-mile coverage area (Long gone)
The equally mysterious "cskphx09" (Channel 7) covering downtown Scottsdale (long gone)
"srpmic-is" (Channel 6) and 8 miles of SR101 (long gone)

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Copyright © 2006 Jon Trent Adams
jon (at) jonadams.com