Radio communications system adaptively assigning channels using power levels of idle channels

A mobile radio communications system comprising:

• a plurality of base stations capable of establishing radio communications with mobile stations, each of said base stations periodically detecting power levels of signals received on idle channels, and responsive to a polling signal for transmitting a response signal indicating the detected power levels, the identifications of said idle channels, the identification of a busy channel if there is one, and the identification of each of said base stations;
• and
• a control station programmed to perform the steps of:
• a) transmitting said polling signal to each of said base stations;
• b) receiving said response signal from each base station;
• c) detecting whether each of the power levels of said idle channels contained in one of said response signals is higher than a specified threshold;
• d) incrementing an interference coefficient of a pair of said base stations by a predetermined amount when said power level is detected as being higher than said threshold, and arranging said coefficient in a matrix pattern according to the identifications of said idle and used channels and the identifications of said base stations;
• e) repeating the steps (c) and (d) until said coefficients are derived for all pairs of said base stations;
• f) deriving from said matrix pattern a plurality of interference estimations for all possible combinations of channels and said base stations;
• g) detecting a minimum value of said interference estimations;
• h) assigning the channels associated with said minimum value to said base stations;
• and
• i) repeating the steps (a) to (h).