Word Press cannot handle questions the way Google does. For this WordPress, OpenBTS by itself yields the best results for Phi Beta Iota: OpenBTS. See especially Range Networks: The ONLY OpenBTS Real Deal.
We prize searches, for they add to the substance of this website, a form of co-creation. Below are some hits from outside
Wikipedia: OpenBTS (Open Base Transceiver Station) is a software-based GSM access point, allowing standard GSM-compatible mobile phones to make telephone calls without using existing telecommunication providers' networks. OpenBTS is notable for being the first free software implementation 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 (AGPL).
Building and Running OpenBTS (SourceForge)