Channel assignment method in a mobile communication system using channel selection order determined by transmission power level

A channel assignment method in a mobile communication system when assignment is required of a communication channel to be used between a base station and a mobile station, said method channel assignment method comprising the steps of:

• selecting a transmission power level at which the reception level of a transmission signal from said mobile station is at least a specified value a;
• selecting communication channels in a first order previously and identically established for all base stations when said transmission power level is at most a specified value b, and selecting communication channels in a second order opposite said first order when said transmission power level exceeds said specified value b;
• estimating an interference signal level in a selected communication channel at said base station and at said mobile station;
• and
• assigning a first communication channel at which the ratio of the reception level of the transmission signal in said transmission power level to said interference signal level is at least a specified value c at both said base station and said mobile station.