Rhizomatica's system architecture consists of a number of different Linux based open sources components running on the commercially available hardware. Please check out the presentations to get a gist of how things are set up.
Base Station Controller -
Base Transceiver Station -
OpenBSC , part of the Osmocom project , is not just a standard BSC (Base Station Controller  ), but a GSM network in a box software, implementing the minimal necessary parts to build a small, self-contained GSM network. It includes a BSC side implementation of the A-bis protocol, as implemented in the GSM Technical Specification 08.5x and 12.21. It also implements a minimal subset of the BSC, MSC and HLR.
To connect calls to the outside of the OpenBSC based network, OpenBSC works together with LCR to route outgoing calls using the SIP  protocol.
FreeSWITCH  is a scalable open source cross-platform telephony platform designed to route and interconnect popular communication protocols using audio, video, text or any other form of media. It was created in 2006 to fill the void left by proprietary commercial solutions. FreeSWITCH also provides a stable telephony platform on which many telephony applications can be developed using a wide range of free tools.
Kannel  is a compact and very powerful open source WAP and SMS gateway
There are two custom packages entirely developed by rhizomatica.
RCCN is a python package with the glue code that makes all the software components work together. It exposes a REST api, the RAPI).
Rhizomatica Community Cellular Network (RCCN)
this is the software for running the Rhizomatica Community Cellular Network
Rhizomatica Admin Interface (RAI)
The interface used by network admins in the communities.
RAI is a php package that uses the REST api and exposes an http administrative interface, allowing admins to register uses, manage payments, broadcast text messages and access the live system statistics.
Our github repo can be found at https://github.com/rhizomatica