Patent ID: 8824889

Claim:
An optical line terminal (OLT) comprising: an optical fiber configured to couple to an optical distribution network (ODN); a downstream transmitter; a first coupler; a wavelength division multiplexer (WDM) coupled to the downstream transmitter, the fiber, and the first coupler, wherein the WDM is not coupled to any other optical components; a second coupler coupled to the first coupler via two optical communication paths; a delay module located on only one of the communication paths between the first coupler and the second coupler; a balanced detector coupled to the second coupler, wherein the balanced detector is configured to receive a plurality of optical signals each of which comprises a unique optical frequency differential, and wherein the optical signals are transmitted at drifting optical carrier frequencies; a multi-channel upstream demodulator coupled to the balanced detector; and a collision control module coupled to the balanced detector or the multi-channel upstream demodulator.