Patent ID: 8014675

Claim:
A method of communicating in a passive optical network communication system in which a central office termination unit and n subscriber termination units are linked by respective optical communication channels to a passive optical coupler, n being an integer greater than one, the method comprising: generating an optical time-division multiplexed signal at the central office termination unit; transmitting the optical time-division multiplexed signal through the passive optical coupler to all of the n subscriber termination units; generating respective optical encoded signals at each of the n subscriber termination units; transmitting the optical encoded signals through the passive optical coupler to the central office termination unit; combining the optical encoded signals from the n subscriber termination units at the passive optical coupler into an optical code-division multiplexed signal; transmitting the optical code-division multiplexed signal to the central office termination unit; generating, at the central office termination unit, a time-division multiplexed signal in which data addressed to different ones of the n subscriber termination units are placed in different time slots; converting the time-division multiplexed signal to the optical time-division multiplexed signal; converting the optical code-division multiplexed signal to an encoded received signal at the central office termination unit; decoding the encoded received signal by using different decoding rules to obtain data sent from different ones of the n subscriber termination units; converting the optical time-division multiplexed signal to a received time-division multiplexed signal at each one of the n subscriber termination units; recovering a first clock signal from the received time-division multiplexed signal at said each one of the n subscriber termination units; extracting the data addressed to said each one of the n subscriber termination units from the received time-division multiplexed signal in synchronization with the first clock signal; generating encoded data in synchronization with the first clock signal at said each one of the n subscriber termination units; and converting the encoded data, at said each one of the n subscriber termination units, to one of the optical encoded signals.