31 Jan
2014
31 Jan
'14
12:25 p.m.
Hi,
GSM does not hop around inside its channel, this is wrong, the frequency is +- some Hz accurate, at least in normal western European commercial GSM networks.
Are you sure about that? Check it out:
https://svn.berlin.ccc.de/projects/airprobe/wiki/A
Legend of first picture. If still in doubt that *most" GSM carriers are hoppers, use rtl_power to scan your region ;-)
GSM doesn't hope _inside_ a channel, it hops between channels.
And the main channel "C0" that contains the FCCH bursts that kalibrate locks to, doesn't hop at all, it's required by spec to be a continuous carrier.
OTOH, the OP said he was in the US and used EGSM band option ... huh ... I thought the US was GSM-800 ?!?
Cheers,
Sylvain