The OpenBTS Project

The OpenBTS Project is an effort to construct an open-source Unix application that uses the Universal Software Radio Peripheral (USRP) to present a GSM air interface ("Um") to standard GSM handset and uses the Asterisk software PBX to connect calls. The combination of the ubiquitous GSM air interface with VoIP backhaul could form the basis of a new type of cellular network that could be deployed and operated at substantially lower cost than existing technologies in greenfields in the developing world.

In plain language, we are working on a new kind of cellular network that can be installed and operated at about 1/10 the cost of current technologies, but that will still be compatible with most of the handsets that are already in the market.

Project Links

The project blog continues.
If you are looking for the now-kinda-famous Burning Man write-up, it's been moved to here. Yes, we will record your IP address. Why? Keep reading.
There is a closed mailing list for OpenBTS support discussions, openbts-discuss (at) sourceforge.net. To subscribe, please send send e-mail to dburgess (at) kestrelsp.com requesting subscription. Be sure to put "openbts" in the subject line. Why a closed list? Keep reading.

Project News (Last Updated 2 June 2009)

We have been in settlement talks with Martone Radio Technology, Inc. for several weeks. Hopefully, our legal conflicts will be resolved soon.
We expect to be ready for one or more pilot system deployments in the Fall of 2009. Candidate sites are under consideration.
We are on-track for an SMS test at Burning Man 2009 as a practice run for pilot system deployments. More will be posted on that as the project develops.
Kestrel is preparing a commerical distribution of OpenBTS. More details here.

OpenBTS Distribution Status

At this time, there are two independent distributions of OpenBTS:

There is a "GNU distribution", available uner GPLv3 from GNU Radio though the gnuradio.org SVN server. This version presently cannot be supported by the original authors, but anyone else is welcome to do whatever they want with it, at least within the bounds of GPLv3.
There is a "Kestrel distribution", available from Kestrel Signal Processing, Inc., also distributed under GPLv3.

What version should I use?

If you want to use OpenBTS in a commercial application, you will need to use the Kestrel distribution. See the Kestrel web site for details. For more information about the Kestrel distribution of OpenBTS, contact dburgess (at) kestrelsp.com. Be sure to put "openbts" in the subject line.

If you do not intend to use OpenBTS in a commercial application, you should probably use the GNU Radio distribution because it is more likely to build cleanly on a wider range of systems and more likely to be in sync with other parts of GNU Radio. Also, patches submitted to the GNU distribution can be moved into the Kestrel distribution, but patches put in the Kestrel distribution cannot be moved in the other direction. "Huh?" you ask. Keep reading.

The "Injunction Thing"

On 3 December 2008, the original authors of OpenBTS became subject to this court order. However, way back on 24 October 2008, copyrights to the OpenBTS project had been transferred to the Free Software Foundation (FSF), with this legally binding document. The transfer also grants back a blanket license to Kestrel Signal Processing, Inc., the original copyright holder, a standard element of FSF assignments.

What does it all mean? The order does not block the original authors from continuing their work on OpenBTS, but does prevent them from contributing to any distribution of OpenBTS that is available through anonymous access mechanisms, so:

FSF/GNU will continue to distribute OpenBTS however they want because they hold the copyright, they are not a party to the lawsuit and the original authors can't stop them.
Because FSF/GNU insists on anonymous access, the practical effect is to prevent the original authors from participating in the GNU-hosted version of the project.
The SourceForge project is similarly affected, and since it was still under the control of the original authors, it has simply been removed.
The original authors can still distribute OpenBTS to known parties, so this injunction does not affect commercial distributions, but does the content of online advertising.

This order was issued by the US District Court for the Northern District of California, case 4:08-vc-02379-CW. This order was requested by Martone Radio Technology, Inc., a former consulting client for whom David Burgess wrote a GSM stack prior to his work on OpenBTS. David Burgess, Harvind Samra, Kestrel and the other defendants in this case deny any wrongdoing and will continue a vigorous defense.

Support (These) Coders' Rights!

Legal defense of OpenBTS costs several thousand dollars every month. You can help support our defense through PayPal. At this time, these donatations are not tax-deductable. Any surplus funds will be donated to 501(c)3 organizations dedicated to the defense of coders' rights, such as the EFF or SFLC.

We sincerely thank those who have contributed already.