Abstract: A method and apparatus for providing an interface between a communications device and a medium carrying an approximately periodic waveform are presented. The method includes providing a first signal in response to detecting a predetermined characteristic of the approximately periodic waveform using switching circuitry that draws a first amount of power drawn from the medium, and in response to the first signal, detecting the predetermined characteristic of the approximately periodic waveform using detecting circuitry that draws a second amount of power drawn from the medium, where the detecting circuitry detects the predetermined characteristic with greater accuracy in time than the switching circuitry detects the predetermined characteristic, and the second amount of power drawn from the medium is greater than the first amount of power.

Abstract: Coupling circuitry implemented with passive components is added to a conventional power supply to enable communications access to a power-line network by a device designed for power-line communications (“PLC device”), in order to achieve certain benefits including minimizing costs.

Abstract: An apparatus and methods are provided for controlling data communications across power lines. The apparatus preferably has a power line interface for interfacing with a power line so as to detect both a wide bandwidth data communications protocol being initiated across the power line and a narrow bandwidth data communications protocol being initiated across the power line synchronously with the power line mains frequency and so as to initiate either a wide bandwidth data communications protocol onto the power line or a narrow bandwidth data communications protocol onto the power line synchronously with the power line mains frequency. The narrow bandwidth of the narrow bandwidth data communications protocol preferably falls within the wide bandwidth of the wide bandwidth data communications protocol. An input wide and narrow bandwidth protocol receiver is positioned responsive to the power line interface for receiving either the wide bandwidth protocol or the narrow bandwidth protocol.