Some special terms we use:
BSC - Base Station Controller
BTS - Base Transceiver Station (the receiver and transmitter)
FreeSWITCH - Scalable open source cross-platform telephony platform. 
GSM - Global System for Mobile Communications 
Kannel - Compact and very powerful open source WAP and SMS gateway.
LCR - Linux Call Router 
OpenBSC - GSM network in a box software, implementing the minimal necessary parts to build a small, self-contained GSM network.
RMAI or RAI - Rhizomatica Administration Interface
RCCN - Rhizomatica Community Cellular Network
VOIP - Voice Over Internet Protocol 
>>note to editors: add links to relevant pages here if they exist <<