OpenBTS

OpenBTS (Open Base Transceiver Station ) is a free software implementation of a mobile radio base station that uses the GSM standard for fully digital mobile networks. OpenBTS is written in C and is distributed in the source code under the terms of version 3 of the GNU Affero General Public License ( AGPL ). It is the first free implementation of a protocol stack for the GSM protocol. It is a sister project of OpenBSC and OsmocomBB, which are developed by the same programmers.

History

The project was started by Harvind Samra and David A. Burgess. One goal of the project is to push the cost of provision of GSM infrastructure in order to improve coverage of rural areas and developing countries to less than one U.S. dollar per station and month. The original developers is a licensed test frequency spectrum available after in similar work they had legal disputes earlier. In a first successful trial use at Burning Man Festival in August 2008 in the course of a week about 120 calls were taught to 95 North American ports. 2010 a permanent GSM network based on OpenBTS was established on the island of Niue the first time. Niue is a small country with a population of about 1,700 inhabitants, where previously the construction of a mobile network with traditional GSM base stations commercially was not lucrative enough.

Operation

A simple OpenBTS installation consists of several software packages: for the mobile radio protocol including GPRS, for sending SMS messages, subscriber authentication and call switching. The latter takes a conventional VoIP system such as asterisk. All of these packages work fine in parallel on a standard (even older ) PC or laptop. The high-frequency part is usually a software- defined radio, connected via USB or Ethernet. Thus, with little effort already a fully functional mobile cell be operated, which is able to supply several participants in a radius of several hundred meters with basic GSM mobile services (voice, SMS, data transfer). The system can achieve with amplifiers and antennas greater performance similar to a commercial mobile radio cell, also handover and connection to a public switched telephone network can be realized. The interface used as a standard VoIP technology allows flexible networking with long- known and proven means.