FAQ for the Burning
Man 2009 "Papa Legba" Test Network
- Who is doing this? This is an activity of the OpenBTS project. The
entity legally responsible for the test is Kestrel Signal Processing, Inc.. The actual
on-site engineers are David Burgess and Harvind Samra.
- Is this legal? Yes. We have an experimental license,
WD9XSP, and a consent letter from Verizon authorizing us to operate in their
KNKN224 block A cellular spectrum. We are also coordinating operations with
Commnet Wireless to prevent interference.
- How much does the service cost me? Nothing.
- What do you do for emergency calls? Nothing. We are an
experimental service and do not support emergency calls.
- Where is your camp? We are Papa Legba, placed at 4:30 &
H. Look for the WD9XSP tower. Drop by for a sticker and a tour.
Black Rock City, LLC
- Does BM-Org know about you? Sorta. The technical side of
the organization is supportive and coordinating network service for our
backhaul. Other parts of the organization are still finding out about
- Are those your trucks and towers at Frog Pond and in
Gerlach? No. That's Commnet Wireless, a commercial cellular carrier who
is providing cellular service at Burning Man this year.
- Are you going to interfere with each other? No. Commnet
will be operating in the block B spectrum under license KNKN225. We will be in
block A. We have exchanged contact information to resolve any unforeseen
- What is you relationship to Commnet? None. Please do not
get us confused.
Service CapabilitiesPapa Legba's primary service is on-Playa
text messaging, the delivery of text messages between handsets within BRC. We
will also have limited support for speech service.
- Can I call the "real world"? If you do get full speech
service, you will indeed be able to call out of BRC.
- Can the "real world" call me? If you have speech service,
you will be able to receive inbound calls from VoIP carriers through the +883 iNum country code.
- Can I use my own VoIP PBX to route calls to my cellphone
while I'm at Burning Man? Yes, as soon as we know our public IP
- Can I text the "real world"? You can send text to many
internet-based IM services, like Gizmo or Skype. You can also send text to
- Can the "real world" text me? You can receive text from
many internet-based IM services, but probably not from cellular
Using My Phone
- Will my phone work with the Papa Legba network? All
current-market phones that work with AT&T or T-Mobile will also work with
Papa Legba, even if they are locked. You can use your existing SIM, too.
- How will you know my phone number? You will tell Papa Legba
via SMS. When your handset first contacts the network, you will receive a text
message asking you to respond with your 10-digit phone number. If that process
is successful, you will receive another message informing you that you have been
provisioned in the network. That's it.
- My phone shows service but I can't make a call. Why not?
Only the first few hundred subscribers will get full speech service. Everyone
else will just get SMS. There are two good reasons for this:
1. We don't have
enough equipment for everyone to get normal speech service.
speech service would change the nature of BRC in ways a lot of people would not
- How do I know my phone is on your network? You will see a
network ID of "001 01", "Test" or "PpaLgba", depending on your handset brand and
- How can I force my phone to use one network or the other?
That depends on your phone model. We are still working on a collection of
- Will my carrier charge me for every text message I send or receive
on the Papa Legba network? No, the Papa Legba network is a separate
isolated network from your normal carrier's network, and no charges will apply
as no SMS is being sent or received through your normal carrier.
- Will putting a Papa Legba sticker on my phone make it work
- What band and technology are you using? GSM850.
- What are your specific frequencies and powers? Our
frequencies will be 870-880 MHz downlink and 825-835 MHz uplink. We will operate
our downlink at 20 W EIRP. In the uplink, the typical GSM handset has a maximum
power of 1 W, although we will use closed link power control to minimize handset
power to the greatest degree possible.
- What RF equipment are you using? See OpenBTSBM2009RF.
- What network software do you use? We use Asterisk for our
speech PBX and provisioning functions. We use a custom server for SMS. All
interfaces are based on SIP/RTP. The GSM stack itself is OpenBTS.
- What is your GSM configuration? We will operate 3 or 4 BTS
units. Each will be a single ARFCN. Each will be configured with channel
combinations V, 3xVII, 4xI. That will give each BTS unit 4 speech channels and
the ability to transfer 300-400 text messages per minute.
- Why "Papa Legba"? Papa Legba is a voodoo deity who mediates
human contact with the spirit world. Like Papa Legba, our radio equipment stands
at a crossroads between seen and unseen worlds.
- How much did this cost? The BOM cost for the full system is
about $16k. We have sponsors, though:
- Martin Pelayo is providing our 70' tower.
- John Gilmore funded part of the development of our SMS air interface and
actually wrote the SMS server himself.
- Voxbone is providing funding and most of our VoIP