A method for using a test data packet signal to test a data packet signal transceiver device under test (DUT) having an operating characteristic defined by a data packet error rate (PER) as a function of data packet signal power (PWR). The test data packet signal power is varied and a test PER is computed as a function of DUT response data packets and test data packets until a measured test PER or a computed test PER extrapolated from measured PERs is equal to a predetermined PER less than and greater than maximum and minimum PERs, respectively.