OpenBTS is a Unix application that uses a software radio to present a GSM Um interface to handsets and uses a SIP softswitch or PBX to connect calls.(You might even say that OpenBTS is a simplified form of IMS that works with 2G feature-phone handsets). The combination of the global-standard GSM air interface with low-cost VoIP backhaul forms the basis of a new type of cellular network that can be deployed and operated at substantially lower cost than existing technologies in many applications, especially rural cellular deployments and private cellular networks in remote areas.

OpenBTS is a product of Range Networks and is distributed in multiple versions under multiple liceneses. This site supports the OpenBTS public release, a subset of the OpenBTS commercial release, distributed under AGPLv3.

OpenBTS is a trademark of Range Networks, Inc.