A method and apparatus are provided for allocating radio frequency carriers in a radio service area having a plurality of radio frequency TDMA carriers and FDMA carriers. The method includes the steps of receiving a call, when the received call is a FDMA call and a FDMA carrier is not available for the FDMA call, then preempting a pre-existing call on a TDMA carrier of the plurality of radio frequency TDMA carriers for the FDMA call and when the received call is a TDMA call and a TDMA slot is not available for the TDMA call, then preempting a pre-existing FDMA call on a TDMA capable carrier of the plurality of radio frequency TDMA carriers for the TDMA call.