Hi,

I'm interested in intercepting L band up-link RACH channel I found the BCCH channel of the spot beam I'm currently in then scan the same ARFCN but in uplink I had a cfile and I tried to read it using gr-gmr1 in the branch sylvain/gr but i have no results , may be I don't know how to use the read utility in sylvain/gr

Although the method should work to detect the RACH burst on L-band, it has only ever been tested on C-band wideband captures, so YMMV. Note that the example .grc graph that's provided does an IQ swap because usually when you get samples from a C-band LNB they underwent a spectrum inversion due to the high-side LO mixing inside the LNB. If you're working off a direct capture off L-band you need to remove that swap from the graph. Also, are you sure you actually _have_ RACH requests in your file and they don't saturate your receiver ? If you have an example capture to post, put it online somewhere and post the link.

I also have another question about the file test.pcap in http://people.osmocom.org/tnt/gmr/ how can I have a file like it and is it l band RACH data or C band.

This was captured on C-band. Cheers, Sylvain Munaut