Yea TIMZ, u r right..
i got the answer also…
in 22 ARFCN, Say 10 ARFCN will be used for BCCH, 1 as Guard Band and remaining 11 for TCH.
If we take hopping in 3/3/2 configuration BTS then 3 ARFCN will be used for BCCH TRXs (1 per sector) are non hopping & remaining 5 TRX will be in hopping mode. For these 5 TRX there will be 5 frequencies at a time, these 5 frequencies should not be adjacent so keeping gap of atleast 1 ARFCN the total requirement is 10 ARFCN.
That is the reason why we can not go beyond 3/3/2 configuration with 4.4 MHz spectrum (in hopping case).
Pls revert if i m not correct…