An RF power fairness method (26) receives a request for supplemental channel resources (160). If sufficient supplemental channel resources (time slots and data rates) are not available, the original request is modified (166). If there is multiple call activity on the supplemental channel, RF power is calculated for each of the simultaneous calls on the shared channel (202, 208). If successful time slots and data rates are found, a grant message is returned from the time slot manager (26) to the base station (164, 170, 180). If insufficient time slots and data rate power are determined, a deny request message is transmitted to the base station (184).