OpenBTS

Stable release
4.0 / March 26, 2014 (2014-03-26)
Repository
Written inC++
Operating systemUnix-like
TypeGSM protocol stack
LicenseGNU Affero General Public License
WebsiteOpenBTS

OpenBTS (Open Base Transceiver Station) is a software-based GSM access point, allowing standard GSM-compatible mobile phones to be used as SIP endpoints in Voice over IP (VoIP) networks. OpenBTS is open-source software developed and maintained by Range Networks. The public release of OpenBTS is notable for being the first free-software implementation of the lower three layers of the industry-standard GSM protocol stack. It is written in C++ and released as free software under the terms of version 3 of the GNU Affero General Public License.