In order to appropriately control transmit power of a common channel for
an MBMS (Multimedia Broadcast/Multicast Service) so as not to become
excessive, a mobile station 1 transmits a TPC command for an S-CCPCH to a
base station through an uplink DPCH1 and a mobile station 2 transmits a
TPC command for an S-CCPCH to the base station through an uplink DPCH2.
When either one of the TPC command for the S-CCPCH transmitted from the
mobile station 1 and the TPC command for the S-CCPCH transmitted from the
mobile station 2 is a TPC command instructing "Up", the base station
increases transmit power of the downlink S-CCPCH and decreases transmit
power of the downlink S-CCPCH when both TPC commands instruct "Down".