A method for improving a frequency utilization efficiency for a wireless communication system having a plurality of cells includes the following steps. At least one primary channel is allocated for each cell, the primary channel being different from that of its neighboring cell. One or more secondary channels are allocated for each cell, which have the same frequencies as their corresponding primary channels but differ in configuration, the secondary channels being different in frequency from the primary channel of the same cell. The secondary channel of the cell is activated for carrying communication traffic when the primary channel of the same cell has a capacity of being used exceeding a predetermined threshold value.