diffrance

Broadcast Control CHannel (BCCH)
BCCH contain system information which is transmitted continuously in cell.
BCCH is always available on time slot 0 of BCCH carrier and it is mandatory for it to be there.
One and only one BCCH should be present in a cell.
BCCH information decoded on idle mode are transmitted in BABCCH list.
BCCH information decoded in call mode are transmitted in BASACH.
Eight type of system information are transmitted on BCCH.
Sys information 1, 2, 2bis, 3, 4 are transmitted on BABCCH.
System information 5, 6, are transmitted on BASACH.
ARFCN
ARFCN (Absolute Radio Frequency Channel Number) specifies a pair of physical radio carriers and channels used for transmission and reception on the Um Interface in GSM cellular networks, one for the uplink signal and one for the downlink signal..Bandwidth for each carrier 200 khz and total 124 chls are in GSM 900 Band