Hello everyone,

I'm looking for help.

I have downloaded and built Airprobe (gsm-receiver, gssm, ) on my Ubuntu machine.

a/ Using the capture file provided on the web site, I could get a first level of decoding done:

nphan@ubuntu:~/airprobe/gsm-receiver/src/python$ more capture_941.8M_112.log

Key: '0000000000000000' Configuration: '' No configuration set. configure_receiver 1670173 0: 15 06 21 00 01 00 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 1670177 0: 15 06 21 00 01 00 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 1670183 0: 15 06 21 00 01 00 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 1670187 0: 15 06 21 00 01 00 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 1670193 0: 15 06 21 00 01 00 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 1670197 0: 15 06 21 00 01 00 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 1670204 0: 01 06 07 60 00 25 54 a8 f9 74 05 5e 18 73 2b 2b 2b 2b 2b 2b 2b 2b 2b 1670208 0: 01 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 1670214 0: 01 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 1670218 0: 01 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 1670224 0: 15 06 21 00 01 00 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 1670228 0: 15 06 21 00 01 00 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 1670234 0: 15 06 21 00 01 00 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b

but in wireshark I can't see any decoded info such as BCCH system info etc...

b/ It looks like my capture isn't working properly either (ie I can't even get the 1st level of decoding as with capture file provided in the web site).

nphan@ubuntu:~/airprobe/gsm-receiver/src/python$ ./capture.sh 953.4M /usr/local/bin/usrp_rx_cfile.py Capturing for 10 seconds to capture_953.4M_112.cfile (4642850 samples) Using RX d'board B: Flex 900 Rx USB sample rate 571.428k nphan@ubuntu:~/airprobe/gsm-receiver/src/python$ ./go.sh capture_953.4M_112.cfile

...

...

gr_fir_ccc: using SSE gr_fir_ccf: using SSE

Key: '0000000000000000' Configuration: '' No configuration set. configure_receiver gr_buffer::allocate_buffer: warning: tried to allocate 115 items of size 568. Due to alignment requirements 512 were allocated. If this isn't OK, consider padding your structure to a power-of-two bytes. On this platform, our allocation granularity is 4096 bytes. nphan@ubuntu:~/airprobe/gsm-receiver/src/python$

I have a USRP1 with 2 RFX900 with a ClockTamer providing 52Mhz clock.

I have changed the various Python scripts so that the RFX daughter on side B and RX2 are selected. I have also changed the clock rate to 52M to match my HW. I have input the frequency of a known BTS (which kal can see and measure the offset).

Any hints about what is wrong in my set-up or process?

Thanks Nghia