Hamdi,
EXTRA TS do not require directly additional capacity in BSC or MFS. It is the amount of packet traffic that will require more GPU (in MFS)
EXTRA TS impacts only the ABIS usage.
But if by putting more EXTRA TS, it generates more GPRS traffic, then you’ll have to redesign GPU’s, Gb interfaces and Ater PS interfaces.
— how to proceed ?
As i said earlier, you need to perform a full study. I can’t explain it on a website !! It’s huge.