In a radio communication system where, concerning the maximum allowable
delay and the reception error rate as required values for QoS, a first
mobile station group of which the maximum allowable delay is less than a
reference value and the reception error rate is a reference value or
more, and a second mobile station group of which the maximum allowable
delay is a reference value or more and the reception error rate is less
than a reference value coexist, the base station sets the transmission
power margin for a mobile station of the first mobile station group to be
higher than the transmission power margin for a mobile station of the
second mobile station group, and a mobile station of the first mobile
station group sets the transmission power margin to be higher than the
transmission power margin of a mobile station of the second mobile
station group.