you snooze, you loose !
“What happens SCPIR in cases where single MS has activated two radio channels?”
Why would a MS have 2 radio channels ?
VAMOS works only for TCH, and therefore each MS needs only one TCH. As if it were in a regular TCH timeslot.
4 MS (a, b, c, d) on one VAMOS TCH timeslot means :
2 MS (a, b) in Half-Rate, paired on the HR-subchannel 0. a is on vamos-subchannel 0, b is on vamos-subchannel 1.
2 MS (c, d) in Half-Rate, paired on the HR-subchannel 1. a is on vamos-subchannel 0, b is on vamos-subchannel 1.
In the physical TCH timeslot, there is two HR subchannels, which are physically independant (as an image : HR0 = even bursts and HR1 = odd bursts).
On HR0 (even bursts), the a and b are tx-ing and rx-ing at the same time.