The present invention provides different scheduling criteria depending on overall system performance in an effort to maintain fairness among mobile terminals and sustain a required QoS level. The invention is particularly effective for multi-carrier systems, wherein scheduling must also take into consideration the carrier used to transmit the scheduled data. In one embodiment, the present invention determines the spread of throughput rates for all mobile terminals being served by a given base station and bases the scheduling criteria thereon. Preferably, a standard deviation calculation is used to measure the throughput spread. The standard deviation of throughput associated with a collective group of mobile terminals is indicative of the differences between the lowest and highest throughputs with respect to the average throughput for the collective group of mobile terminals.