I want to build a passive (rx-only) scanner to listen to GSM and UMTS traffic. I am not interested in breaking encryption or anything like that - but more interested in collecting statistics and such.
Things like numbers of RACH bursts. Number of active calls on a cell/frequency/channel.
I found some things online - like OpenBTS and OpenBTS-UMTS. There are great, but the appear to be only intended to emulate and Basestation/ENodeB. I am looking for somthing a bit more generic - which can just analyse channels (e.g. in GSM scan all the common control channels and look for RACH bursts and assignment commands).
Is there anything like this out there? - Or can OpenBTS/OpenBTS-UMTS be made to do this?
I have an Ettus USRP to get started with.... not really sure I want to write a stack my-self!