[Discuss-gnuradio] Reception problem with gsm-tvoid and gsmdecode

[José Carlos Reyes]

Hi all,

I would like to ask you a basic question.
I receive
the BCCH and CCCH (PCH and AGCH) GSM channels with gsm-tvoid and
gsmdecode. I use USRP. For instance, to do that, I type something like:

./gsm_scan.py -p d -r e -c 104 | ../../../gsmdecode/src/

gsmdecode -i > myfile.txt

The problem is that a lot of messages are missed. While I am receiving I can see warning messages like the followings:

sch.c:254 ERR: conv_decode 7
gsmstack.c:162 cannot decode fnr=0x002921c8 ts=0
gsmstack.c:162 cannot decode fnr=0x002921ce ts=0
gsmstack.c:162 cannot decode fnr=0x002921e2 ts=0
gsmstack.c:162 cannot decode fnr=0x002921ed ts=0
gsmstack.c:162 cannot decode fnr=0x002921f1 ts=0
....
...
sch.c:254 ERR: conv_decode 7
gsmstack.c:162 cannot decode fnr=0x00292229 ts=0
sch.c:254 ERR: conv_decode 1
....

The BTS (Base Station) from I am receiving is really near my USRP.
What Could I do to solve this? Any Suggestion?

Thanks in advance for your time.
Cheers

Jose