hi mkt,
1.
if you activate DTX DL, the BTS stops sending normal burst on the assigned timeslot if there is no voice to transmit.
if you activate DTX UL, the MS doesn’t send a normal burst on the assigned timeslot if there is no voice to send.
Instead of sending a normal burst, a dummy burst will be sent (i don’t know how often i will be sent, i think it is less frequent than a normal burst… = not on every timeslot)
2 & 3 : the exact solution shall be found in 3GPP… I don’t have time to look for it now though, but i’ll keep it in mind.