<div dir="ltr"><div>Thanks for all answers . I understand better now<br></div><div>I'll test and let you know</div><div>Pascal<br></div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Le mer. 8 juil. 2020 à 10:50, Sylvain Munaut <<a href="mailto:246tnt@gmail.com">246tnt@gmail.com</a>> a écrit :<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div class="gmail_quote"><div>Hi,</div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>this line is working fine <br></div></div></blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>./gmr1_rx_sdr.py --args airspy -a 927 -s 6000000 -B L -f 1553968750 -g 19 -b 40</div><div>then after <br></div><div>./gmr1_rx 4 /tmp/arfcn_927.cfile <br></div><div>wireshark is giving all informations <br></div><div><br></div><div>I have "immediate assignment on ARFCN 928 929 930 931 <br></div><div><br></div><div>I tried to do the same with 928 929 930 931 <br></div><div>./gmr1_rx_sdr.py --args airspy -a 929 -s 6000000 -B L -f 1554031250 -g 25 -b 40</div><div>with 1 Gb of datas, I can retrieve only 2 frames in wireshark <br></div><div><br></div><div>I'm sure there is traffic on these 4 channels</div></div></blockquote><div><br></div><div>So to follow assignments to dedicated channels, you need to use the `live` branch of the code and use gmr1_rv_live binary.</div><div><br></div><div>Basically you can't decode _just_ the traffic channel (i.e. the 928 929 930 931 ARFCNs). You need to first lock to the BCCH ( 927 ) and then follow the assignment so you have the proper alignment etc ...</div><div>Which means you need to be receiving both channels at the same time, using multiple `-a` arguments to gmr1_rx_sdr.py</div><div><br></div><div>And then you use the gmr1_rx_live binary which supports processing several channels in parallel and feed it all the data at once using something like :</div><div><br></div><div>gmr1_rx_live 4 927:/tmp/arfcn_927.cfile 928:/tmp/arfcn_928.cfile ...</div><div><br></div><div>Each of the argument after the '4' (which is the sample-per-symbol) is in the form ARFCN:FILE where ARFCN is the ARFCN number and FILE is the path where to find the data corresponding to that ARFCN number.</div><div><br></div><div>And then the code will be able to find the BCCH lock to it and when it sees an assignement command, it will look if it has a data file available for that ARFCN and if it does, it will follow the assignement and start decoding the dedicated channel as well.</div><div><br></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div></div><div>Is "immediate assignment " means TCH3 and voice ?</div></div></blockquote><div><br></div><div>Not all Immediate Assignement means TCH3/voice, they can be control channels or packet data or whatever else ... it just means a phone was assigned a dedicated channel, you need to look at what type and what mode of channel it is to know what it's going to carry.</div><div><br></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>I tried all branches on git hub with same result <br></div><div><br></div><div>What is usage of gmr1_process_recording.py ? and arguments</div></div></blockquote><div><br></div><div>So this script doesn't really "do" anything. All it does is take the filename of a file recorded by the osmocom_fft program (which uses a filename pattern that includes the center frequency and sample rate) and then it prints the commands you can use to process that recording. Mostly it's going to be two commands, the first one that will take the .cfile recording and split it into a bunch of ARFCN channels and then another command that will process all those ARFCN channels.</div><div><br></div><div>But as I said, it won't run those commands, it just prints them, you need to cut&paste them and run them and/or adapt them to your needs.</div><div><br></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>What is usage of gmr1_ambe_decode and gmr1_rach_gen</div></div></blockquote><div><br></div><div>* gmr1_rach_gen generate examples RACH bursts, it's used for internal testing of the c-band monitoring stuff in gnuradio</div><div>* gmr1_ambe_decode decodes TCH3 data payloads into PCM audio</div><div><br></div><div>Cheers,</div><div><br></div><div> Sylvain Munaut</div><div><br></div><div><br></div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
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