A method of dynamically adapting the number of available channels in a first set of available channels for use by at least one signal source in a communications system. The method includes the steps of computing at least one received signal statistic; determining an adjustment to the number of available channels in the first set based on the at least one computed received signal statistic; and signaling to each active signal source in the system to cause the signal sources to use the adjusted number of available channels for transmitting signals.