A frequency control method in a CDMA communication system for controlling the frequency of a communication channel to be established between a CDMA base station and a plurality of mobile stations that communicate with said CDMA base station, comprising the steps of:
- determining that a particular mobile station among said plurality of mobile stations has failed to control its transmission power when the difference between a reference Eb/I0 and reception Eb/I0 of a communication channel established between said particular mobile station and said CDMA base station exceeds a predetermined value;
- and
- instructing normal mobile stations other than said particular mobile station to change the frequency used as the communication channel to another frequency and changing the frequency used as communication channel to the frequency after said change.