A base station controller includes circuitry for determining whether a transmitter is transmitting in a DTX mode or operation for a supplemental channel in a CDMA network. The invention includes the steps of determining frame quality metrics for data received on a fundamental and a supplemental channel. If the frame quality metric is good, meaning that the number of errors is below a defined threshold, on the supplemental channel, then the mobile station is not, by definition, within a DTX mode of operation. However, if each of the base stations that are on the active list of base stations for the mobile station report that the mobile station frame quality metric is not below or within a specified threshold, then the base station performs a calculation to determine whether the mobile station is in a DTX mode of operation or is transmitting a null set. Specifically, the base station calculates a signal to noise ratio for the pilot channel as well as for the supplemental channel and compares or determines a ratio of these two calculations. If the ratio is within or below a specified threshold, then an erasure has occurred. If not, then the mobile station did transmit in a DTX mode of operation.