> I don't really know if full spectrum monitoring it's required to do the > cracking/interception job >
No, it's not, unless you want to listen to _all_ the communication taking part simultaneously in the zone ... Most likely the local cell isn't gonna hop between all the ARFCN in the band ... The two config I've seen here locally : - A few ARFCN relatively close together ( < 60 MHz and even often < 25 MHz ) - The BCCH ARCFN + A large contiguous range of hopping ARFCN somewhere else. Software mod (of the USRP firmware) could handle both these cases. The first one can even be handled totally on the PC side if < 25 MHz IMHO, handling the first case is sufficient for now, and only when good software exists for that case should the other use case be handled. It's also true that a Winradio SDR card can do 50channel/s hopping, that > maybe useful for the techniques. > GSM hopping changes frequency every frame ( ~ 4.6 ms ). 50/s isn't gonna cut it. > However let's see with USRP how the full spectrum can be monitored, it sounds slightly costly and unefficient. Yes. And you didn't even took into account _how_ are you gonna connect 14 USRP2 on a PC ? Each one is gonna use up the full gigabit link so you'll need 14 gigabit card, the internal bandwidth to support that and somehow the processing power to process that ... Sylvain
_______________________________________________ A51 mailing list [email protected] http://lists.lists.reflextor.com/cgi-bin/mailman/listinfo/a51
