Hi Andreas,
- layer23 doesn't currently filter much the IMM.ASS it receives so you may end up on a channel that's not yours ... beware.
what do you mean with "much"? i filter the channel with the channel request number (includes random number) in the IMM.ASS message. maybe in the future we can filter the time slot where it was sent (RACH confirm) and compare it also. but this requires RACH confirm with GSM time where it was sent.
I was refering to "layer23" the quick & dirty test app if you want to play with the layer1.
The mobile app does everything properly.
For the RACH_CONF, from the code, I see that it already contains the frame number at which the RACH was sent. (in the l1ctl_info_dl header of the CONF message, the frame_nr field is set)
Sylvain