the max_mcs possible for the TBF’s in one TRX is computed depending on the number of GCH available.
If there are not enough GCH for that TRX, the max_mcs of that TRX is decreased.
nb_gch = 3 –> max MCS = 6
nb_gch = 4 –> max MCS = 7
nb_gch = 5 –> max MCS = 9
the MCS is then decreased per TBF depending on TBF radio quality, but it can’t exceed this max_mcs.