Patent ID: 8208815

Claim:
An apparatus for controlling timing of an upstream transmission from an optical network termination device to an optical line termination device in a passive optical network, the apparatus comprising: a receiver to (i) receive a downstream transmission from the optical line termination device, and (ii) analyze the downstream transmission to determine a core clock signal for the receiver; a transmitter to (i) form the upstream transmission based on processing of the downstream transmission, and (ii) produce a phase offset signal to control conversion of the core clock signal to a transmitter clock signal offset, wherein the transmitter clock signal offset is used in timing the transmission of the upstream transmissions; a clock data recovery circuit to recover a bit rate from the downstream transmission received by the receiver; a clock generator to generate the core clock signal based on the bit rate; an offset timer and control circuit to receive the core clock signal from the receiver, and generate a transmitter clock signal from (i) the core clock signal and (ii) the phase offset signal; and an upstream framing controller coupled to the offset timer and control circuit, the upstream framing controller to communicate the phase offset signal.