Oh, here are some (good) answers :
I was wrong before, the SMS should be interrupted in order to setup the TCH call.
The short message service will be supported by an SDCCH or SACCH, depending on the use of a TCH;
– When a TCH is not allocated, the short message service will use an SDCCH;
– If a TCH is allocated during a short message transaction on an SDCCH, the short message
transaction will stop and continue on the SACCH associated with the TCH;
– If a TCH is allocated for the short message service, the short message service will use the
– When an entity using a TCH finishes its transaction, the RR-sublayer may choose to continue an
ongoing short message transfer on the SACCH, or optionally transfer it to an SDCCH.
I knew the answer about what happens to the Measurement Reports when the SMS being sent during a TCH call (on the SACCH).
It’s true that SACCH is already used to transmit MR. So how the hell does the SMS go through… I knew the answer, but i can’t recall… sorry.