A base station system supporting multi-sector/multi-FA in which, when a board goes out of order, a redundant board is automatically switched on, so as to prevent the call from being cut off and the entire capacity of the system from being influenced, thereby enabling the system to maintain normal operation and to be perfectly managed. In the base station system, signal transmitting and receiving paths of up- and down-converters are separated from each other, each board contains all FAs, and redundant boards are utilized, so that the system can normally operate in soft/hard-redundancy modes without cut-off of the call, even when a problem occurs in the paths.