A method, comprising: - execution of a communication over at least one power line of a power supply network using at least one frequency band; - ascertainment as to whether an interference component has occurred during a least a first power supply network period in a signal of a monitoring frequency band; wherein - the frequency band differs from the monitoring frequency band; characterised in that, the method further comprises: - determination of at least one occurrence time period, in each case comprising a start and end time, of the at least one interference component during the first power supply network period; and - reduction of a transmission power in at least one frequency band, at least for the occurrence time period determined, in at least one subsequent power supply network period, wherein - the determination of at least one occurrence time period of the at least one interference component comprises the detection of the amplitude of the signal in the monitoring frequency band, and - the ascertainment as to whether an interference component has occurred in a signal of a monitoring frequency band during at least a first power supply network period, takes place depending on a predefined threshold value and the amplitude detected; and wherein - the power supply network period is subdivided into a plurality of m-time periods, and - the method comprises the determination of a reduction factor depending on the at least one occurrence time period determined for the at least one frequency band for at least one of the m-time periods of the power supply network period; wherein - the at least one reduction factor is stored in a means of storage in a PLC device, - the at least one reduction factor is updated during predefinable time periods during the operation of the PLC device, and wherein - at least one low-frequency test carrier, which is a signal <10 MHz, is generated in predefinable time periods, wherein - at least the first harmonic of the test carrier is monitored for purposes of ascertaining an interference component, and for purposes of determining an occurrence time period, and - in the event that an interference component is ascertained, at least one reduction factor is updated. - execution of a communication over at least one power line of a power supply network using at least one frequency band; - ascertainment as to whether an interference component has occurred during a least a first power supply network period in a signal of a monitoring frequency band; wherein - the frequency band differs from the monitoring frequency band; - determination of at least one occurrence time period, in each case comprising a start and end time, of the at least one interference component during the first power supply network period; and - reduction of a transmission power in at least one frequency band, at least for the occurrence time period determined, in at least one subsequent power supply network period, wherein - the determination of at least one occurrence time period of the at least one interference component comprises the detection of the amplitude of the signal in the monitoring frequency band, and - the ascertainment as to whether an interference component has occurred in a signal of a monitoring frequency band during at least a first power supply network period, takes place depending on a predefined threshold value and the amplitude detected; and wherein - the power supply network period is subdivided into a plurality of m-time periods, and - the method comprises the determination of a reduction factor depending on the at least one occurrence time period determined for the at least one frequency band for at least one of the m-time periods of the power supply network period; wherein - the at least one reduction factor is stored in a means of storage in a PLC device, - the at least one reduction factor is updated during predefinable time periods during the operation of the PLC device, and wherein - at least one low-frequency test carrier, which is a signal <10 MHz, is generated in predefinable time periods, wherein - at least the first harmonic of the test carrier is monitored for purposes of ascertaining an interference component, and for purposes of determining an occurrence time period, and - in the event that an interference component is ascertained, at least one reduction factor is updated.