Hi all, I was absent these days so I didn't respond imediately.

Here is what one usrp2 device recorded while another ran OpenBTS:

http://www.vercund.com/bts/usrp_949.4e6.cap

or exported to plain text:

http://www.vercund.com/bts/usrp_949.4e6.txt

However, none of the phones I have still cannot see OpenBTS network.

Cheers,
Ljubomir

2011/6/14 Thomas Tsou <ttsou@vt.edu>
2011/6/13 <ljubex@gmail.com>:
> I have to correct myself a little.
>
> Here is a part of spectrum: http://postimage.org/image/2ioamk6x0/
>
> And output of kal for corresponding frequences of strongest nearby stations
> (945.2, 946.8, 947.4 and 948.8):
>
> Using GSM-900 channel 51 (945.2MHz)
> average [min, max] (range, stddev)
> + 9.586kHz [9539, 9637] (98, 28.123222)
> overruns: 0
> not found: 62
>
> Using GSM-900 channel 59 (946.8MHz)
> average [min, max] (range, stddev)
> + 9.621kHz [9582, 9658] (76, 20.005610)
> overruns: 0
> not found: 28
>
> Using GSM-900 channel 62 (947.4MHz)
> average [min, max] (range, stddev)
> + 9.646kHz [9623, 9675] (52, 14.832599)
> overruns: 0
> not found: 0
>
> Using GSM-900 channel 69 (948.8MHz)
> average [min, max] (range, stddev)
> + 9.658kHz [9647, 9672] (26, 6.599962)
> overruns: 0
> not found: 0
>
> So basicaly clock offset is still to high if I get it well. Retreiving a
> signal with airprobe is very good point, that will be my following step for
> sure ;)

Those number are not abnormal for a non-referenced usrp. An external
reference will help, but it's difficult to say if that's the cause.
I've connected phones many times with higher deviations. The signals
from your local stations also appear to be quite strong. Airprobe
output should be interesting.

Thomas