A system that incorporates aspects of the subject disclosure may perform operations including, for example, receiving a first signal operating at a first carrier frequency, receiving a second signal operating at a second carrier frequency, the first carrier frequency differing from the second carrier frequency, generating a combined signal based on the first signal and the second signal, measuring power levels in the combined signal, averaging at least a portion of the power levels to generate an average power level, determining a threshold according to the average power level, and monitoring interference in the combined signal according to the threshold. Other embodiments are disclosed.