The “Burning Man” Private Networks

The history of this company traces back to OpenBTS, an all-software GSM stack that was started and largely written by Legba’s founder. And cellular networks at the Burning Man festival figure largely in the history of OpenBTS. These networks gave us our first experiences with large private networks (large coverage areas and many subscribers) in very challenging circumstances.

(All photos in this post were taken by our camp teams.)

What is Burning Man?

Burning Man started in the early 1990’s as a gathering of performance artists and anarchists on an alkali flat in the Black Rock Desert of northern Nevada. In recent years, as many as 70,000 people have attended, living together for a week in “Black Rock City”, with its radial street plan covering about 7 sq km. The front of the ticket is usually beautiful and the back of the ticket always has bold letters saying, “You voluntarily assume the risk of serious injury or death by attending.” Other than these basic facts, Burning Man is difficult to describe.

Black Rock City 2009 from the air.

OpenBTS and Burning Man

In the Spring of 2008, OpenBTS was coming to life on the bench and we wanted to run a test network. Our adviser at the time, Glenn Edens, suggested that we run one at Burning Man, since, at the time, there was no cellular coverage in the area, and probably 50,000 people who might try to use it. We got our experimental license (WD9XKN), bought some tickets, packed up a camp and a week’s worth of supplies, and headed to the desert. I remember my first impression of BRC. Stuck in a queue for hours on the approach road, listening to BMIR, I got my first strong smell of the playa dust and said my fellow travelers, “It smells like chalk dust and crazy.”


This first test site was real hack, with amps and duplexers salvaged from eBay, a hand-made interdigital filter to improve receiver isolation, and the software running directly out of a MacBook laptop, balanced on a bag of ice every afternoon so the USB ports didn’t fail in the heat. Nothing behaved like in the test setup back home. Still, in two good days of operation, we managed to connect about 100 calls to the outside work using Asterisk, a VoIP account, and the Playanet wifi. (We bypassed SIM authentication and let anyone use the network.) Most of these calls were from total strangers who happened to notice that they got service when they passed near our camp. Our biggest challenge was power. Our wind turbine never really produced anything, keeping fuel in the generator was a hit-or-miss proposition, and the batteries boiled over in the 40C heat. But just the fact that we had tried this opened some doors for us and made us a name with old-school Silicon Valley hackers, including John Gilmore, who became a sponsor and code contributor for the next few years, and some of our camp visitors included RAN engineers and lab directors from AT&T, Verizon, and Sprint.

We decided to try again in 2009, and 2010, and 2011, and 2012, and 2013.


In 2009, we had more money, more experience, and a little bit of a following, with camp participants from the US, Denmark, Israel, and Mexico. We got a registered “theme camp” under the name Papa Legba, giving us a reserved space and early access to the site, allowing nearly a week of operation. We ran on a mix of wind, solar, and gasoline. We also had company in the radio spectrum, with a commercial cellular operator trying to cover the festival. A CNET reporter tracked us down and wrote it up, and we got a write-up in at least one telecom blog at the time.


In 2010, we had our biggest camp, including a reporter from Voice of America who was looking for ideas for a pet project. We had a lot of fun that year and routed many thousands of calls. We allowed outside calls, to the “default world” outside of Black Rock City, but with a 3-minute time limit. At the end of the call, we had a message telling people to get off the phone and go enjoy the festival, a very, um, informal message, recorded by friend-of-the-camp Lisa Hyde. Lots of people heard the message and eventually a curious vlogger paid us a visit.


In 2011, we made our first attempt at a multi-site network, with one tower at the camp an another on the other side of the city. We got some tough lessons in backhaul reliability and unattended equipment, and we met some really interesting people, interesting even by the standards of Burning Man. We also replaced our gasoline generator with propane, which simplified our fuel logistics.


In 2012, we ran another multi-site network, this time with a more reliable backhaul and a better management plan. We also used Yate for the first time, instead of Asterisk, and collaborated with Tropo for call routing. (Tropo was a Twilio-type service, later bought by Cisco.) The project got a write-up in TechCrunch. It was the largest of our BRC networks, and our last “good burn”.


The Burning Man network started as part field test and part publicity stunt, but in the process, we learned some things we would not have learned in other places, like how to deal with insanely high registration loads from thousands of handsets, how to take advantage of 2G authentication gaps for something more positive than man-in-the-middle attacks, and how to set up private networks with very little existing infrastructure. It was a good experience, for everyone involved.