Hmmm……well, suppose there are 2 TRXs under a BTS, then, for obvious reasons BCCH will be on, say TRX0, and TRX1 will hv all the remaining TCHs. So in this case TRX0 is a BCCH TRX while TRX1 is a TCH TRX. But it should not matter though, except for some extraordinary behaviour!!