A band of interest is divided into band segments. A scan frame is sent by a transmitter at a transmitting PLC node across each band segment. A receiver at a receiving node scans the band segments, listening for the scan frame. Upon detecting a scan frame, the receiving node measures the signal quality of each OFDM subcarrier modulated with symbols from the scan frame. The subcarrier signal quality values are stored in a table. Upon completion of the scan process, the table contains a signal quality value for each subcarrier within the band of interest. The table is then analyzed to find an operating band consisting of subcarriers with a highest average signal quality or a band that results in greater than a pre-determined minimum signal quality. The invented methods and embodiments may operate periodically to readjust the operating band configuration in the presence of electromagnetic interference including time-variant interference.