A USRP1 *could* be enough to fully decode one side of the conversation (either up or down link). The problem of frequency hopping kicks in if a BTS has too many frequencies. Even if everything is in the clear, then you would still need to interpret the hopping sequence and follow it fast enough. That seems hard. Either that or capture the entire frequency band, which will probably be too much data for the USB throughput. To get past the data-bandwidth trouble you'd need to implement some kind of pre-selection (like following the hopping sequence) on the USRP1's FPGA and I don't think the FPGA will manage.
But if you're listening in on BTSs that transmit on only very few frequencies, then you could listen in on one side of the conversation. Fabian On Fri, Jan 15, 2010 at 12:41 AM, Alvin Liebe <[email protected]> wrote: > Hi all > according your experience an Usrp1 board would be enough to fully decode > a call with only a5\0 encryption (not encrypted) ? > or there are bandwidth issues ? > > > > _______________________________________________ > A51 mailing list > [email protected] > http://lists.lists.reflextor.com/cgi-bin/mailman/listinfo/a51 > > _______________________________________________ A51 mailing list [email protected] http://lists.lists.reflextor.com/cgi-bin/mailman/listinfo/a51
