And that network runs on open source. OpenBTS, an all-software cellular transceiver, is at the heart of the network running on that box attached to a treetop. Someday, if those working with the technology have their way, it could do for mobile networks what TCP/IP and open source did for the Internet. The dream is to help mobile break free from the confines of telephone providers’ locked-down spectrum, turning it into a platform for the development of a whole new range of applications that use spectrum “white space” to connect mobile devices of every kind. It could also democratize telecommunications around the world in unexpected ways. Startup Range Networks, the company that developed the open-source software powering the network, has much bigger plans for the technology. It wants to adapt the transceiver to use unlicensed spectrum for small-scale cellular networks all over the world without the need to depend on the generosity of incumbent telecom providers or government regulators.
OpenBTS is a Unix-based software package that connects to a software-defined radio. On the radio side, it uses the GSM air interface used globally by 2G and 2.5G cellular networks, which makes it compatible with most 2G and 3G handsets. On the backend, it uses a Session Initiation Protocol (SIP) “soft-switch” or a software-based private branch exchange (PBX) server to route calls, so it can be integrated with VoIP phone systems.