it's correct. the phenomenon only occurs with my own tests... so tx gsm is very close to rx gsm...
what should i do in my program that parse the bursts? skip the double frame and read on? or skip all frames with uplink flag set?
i shall investigate this evening...
cheers,
ps. can i ask you a question about weak frames? what i noticed: the offset between si5, si5ter, si6 and the first si6 frame after encryption is not always 204 frames is this correct?
----- Oorspronkelijk e-mail ----- Van: "Sylvain Munaut" 246tnt@gmail.com Aan: "g roelant" g.roelant@telenet.be Cc: "osmocomBB" baseband-devel@lists.osmocom.org Verzonden: Maandag 24 december 2012 09:45:10 Onderwerp: Re: double frames in burst file
double frame numbers
Just means some are from uplink and some from downlink frequencies. Some subchannels of SDCCH have uplink and downlink on the same frame and if the target phone is clone enough you can receive the frames from the phone as well. The 'arfcn' field should have the ARFCN_UPLINK flag set (grep libosmocore to know the value).
Cheers,
Sylvain