Hybrid clocking scheme for transmitting packetized audio and power over a common conductor

A method of synchronizing timing of an audio source and a plurality of endpoints each having a speaker for playback of audio, an Ethernet receiver coupled to the speaker, and a power line communication (PLC) receiver coupled to the Ethernet receiver, wherein the audio source is configured to transmit audio and power over a common conductor to the plurality of end-points, wherein the audio source comprises a power supply for generating the power, a PLC transmitter coupled to an output of the power supply, an Ethernet audio transmitter coupled to the PLC transmitter, and a master clock coupled to the PLC transmitter and the Ethernet audio transmitter;

• wherein the method comprises:
• generating, by the power supply, the power,
• generating, by the PLC transmitter, a PLC encoded signal comprising the audio,
• generating, by the master clock, a master clock signal for both the Ethernet audio transmitter and PLC transmitter;
• synchronizing, using the master clock signal, the Ethernet transmitter with the PLC transmitter;
• transmitting, by the PLC transmitter, the PLC encoded signal to an end-point of the plurality of endpoints over the common conductor;
• receiving, by the PLC receiver of the end-point, the encoded signal;
• recovering, by the PLC receiver, the master clock signal from the received signal;
• and
• providing the recovered master clock signal to the Ethernet audio receiver of the endpoint to synchronize the Ethernet transmitter of the audio source with the Ethernet receiver of the end-point;
• wherein the PLC signal comprises PLC telemetry information including PLC symbol latency and jitter, and wherein the method further comprises adjusting, in the end-point, the recovered master clock signal using the PLC telemetry information to align with an audio sample stream transmitted by the audio source to the plurality of endpoints.

A distributed audio speaker system comprising

• an audio source,
• a plurality of end-points, each end-point of the plurality of end-points having a speaker configured to playback the audio, an Ethernet receiver coupled to the speaker, and a power line communication (PLC) receiver coupled to the Ethernet receiver, wherein the audio source is configured to transmit audio and power over a common conductor to the plurality of end-points, wherein the audio source comprises a power supply for generating the power, a PLC transmitter coupled to an output of the power supply, an Ethernet audio transmitter coupled to the PLC transmitter and a master clock coupled to both the Ethernet audio transmitter and the PLC transmitter and configured to generate a master clock signal for both the Ethernet audio transmitter and PLC transmitter, wherein the PLC transmitter is configured to generate a PLC encoded signal comprising the audio and to transmit the PLC encoded signal over the common conductor, wherein the audio comprises precision time protocol (PTP) audio packets;
• and
• an end-point of the plurality of endpoints configured to receive the PLC encoded signal comprising the PTP packets, wherein the PLC receiver of the end-point is configured to monitor timing of PLC encoded symbols of the PLC encoded signal to adjust and to re-timestamp the PTP packets received from the audio source for compensating for any latency or jitter in the transmission of the PLC encoded signal.