Patent ID: 8649443

Claim:
A device for communicating digital data over power lines, the device comprising: a power line interface for transmitting data over one or more of a low band of frequencies and a high band of frequencies; a clock generation unit configured to generate a plurality of scaled sampling frequency clocks; an orthogonal frequency division multiplexing (OFDM) modulation unit configured to generate OFDM symbols using a set of tones for the one or more bands of frequencies; a preamble generation unit configured to generate a plurality of preamble sequences for the one or more bands of frequencies using one or more of the scaled sampling frequency clocks; a preamble detection unit to configured detect one or more preamble sequences for the one or more bands of frequencies using one or more of the scaled sampling frequency clocks; and a backoff unit coupled to the preamble detection unit and to the power line interface, wherein the preamble detection unit is configured to detect a preamble sequence that is generated by a non-interoperable device, wherein the non-interoperable device cannot demodulate the OFDM symbols generated by the device, wherein the backoff unit is configured to cause postponement of data transmission by the power line interface when the preamble detection unit detects a preamble from the non-interoperable device.