2+2+2 – 3 sectors, 2 TRX in each sector – 6 TRX->6*8=48 channels, 3 have to be BCCH, there could be some SDCCH also and the rest would be TCH
4+4+4 – 3 sectors, 4 TRX in each sectors – 12TRX -> 12*8 = 96 channels (TS) – 3 BCCH, some SDCCH and the rest would be TCH