
Open Source GSM Network at Burning Man Festival
Since the 1990s, tens of thousands of people have been gathering in the deserted Black Rock desert in Nevada for the Burning Man counter-culture festival . As usual, the eight-day event starts on the last Monday of August at 00:01 local time. About 50,000 people came this year, but not only record attendance is a feature of the festival. The fact is that two years ago, open source hardware enthusiasts built a fully-fledged GSM network in the desert, using solar panels and free equipment. The network costs the organizers a penny, and anyone can use it for free.
Perhaps this is the world's first open GSM network of this magnitude. According to engineers, their system can serve as a prototype for creating cheap GSM networks in third world countries, including Africa (anlim for voice traffic can cost about $ 2 per month for a mobile operator to make good profit). In an interview with Network World , engineers talk in detail about network design.
GSM base stations run on the free OpenBTS program(licensed under AGPLv3) under Unix, which together with Universal Software Radio Peripheral (USRP) provides a normal GSM interface for any standard GSM phone, without the need to make any modifications to it. At the same time, the OpenBTS base station requires only 50 watts, unlike standard commercial GSM equipment, so even solar panels are enough for it. Such a station can fit literally in a shoe box.

Next, the open IP-PBX Asterisk routes calls over VoIP. From a network point of view, every GSM phone becomes a SIP client.

To build the network, the organizers had to take an official license from the FCC, as well as agree with neighboring operators on the division of the frequency range. When the user enters the coverage area of the Burning Man base station, he receives an SMS to confirm his consent to the transition to a new “operator”.
You can make calls to any number, but you will receive calls only from other subscribers who are on the Burning Man network, because roaming agreements are not concluded with operators. But everything is free and the network is made by hand.



In September, it is planned to launch the first commercial startup, which will build such cheap GSM networks in different regions of the world. It is estimated that an OpenBTS base station will cost about $ 10,000, which is about 5-10 times cheaper than a conventional base station on a commercial cellular network.
Since the beginning of this year, several similar pilot projects at OpenBTS have already been launched in India, Africa and Southeast Asia.
Perhaps this is the world's first open GSM network of this magnitude. According to engineers, their system can serve as a prototype for creating cheap GSM networks in third world countries, including Africa (anlim for voice traffic can cost about $ 2 per month for a mobile operator to make good profit). In an interview with Network World , engineers talk in detail about network design.
GSM base stations run on the free OpenBTS program(licensed under AGPLv3) under Unix, which together with Universal Software Radio Peripheral (USRP) provides a normal GSM interface for any standard GSM phone, without the need to make any modifications to it. At the same time, the OpenBTS base station requires only 50 watts, unlike standard commercial GSM equipment, so even solar panels are enough for it. Such a station can fit literally in a shoe box.

Next, the open IP-PBX Asterisk routes calls over VoIP. From a network point of view, every GSM phone becomes a SIP client.

To build the network, the organizers had to take an official license from the FCC, as well as agree with neighboring operators on the division of the frequency range. When the user enters the coverage area of the Burning Man base station, he receives an SMS to confirm his consent to the transition to a new “operator”.
You can make calls to any number, but you will receive calls only from other subscribers who are on the Burning Man network, because roaming agreements are not concluded with operators. But everything is free and the network is made by hand.



In September, it is planned to launch the first commercial startup, which will build such cheap GSM networks in different regions of the world. It is estimated that an OpenBTS base station will cost about $ 10,000, which is about 5-10 times cheaper than a conventional base station on a commercial cellular network.
Since the beginning of this year, several similar pilot projects at OpenBTS have already been launched in India, Africa and Southeast Asia.