Patent ID: 7783198

Claim:
A passive optical network comprising: a central office for generating downstream optical signals and receiving multiplexed upstream optical signals; a plurality of optical network units for receiving corresponding downstream optical signals and for generating subcarrier channels carrying electrical data of assigned frequencies; and a remote node having at least one converter for photoelectrically converting the channels into electrical data and for electro-optically converting the electrical data into at least one upstream optical signal, wherein the converter comprises: an optical-to-electrical converter for photoelectrically converting corresponding subcarrier channels into electrical data; an electrical-to-optical converter for electro-optically converting the electrical data converted by the optical-to-electrical converter into an upstream optical signal with an equal wavelength; a first circulator for outputting the upstream optical signal converted by the electrical-to-optical converter to the central office and for outputting a corresponding downstream optical signal to a second circulator; and the second circulator for outputting the corresponding downstream optical signal, which is received from the first circulator, to corresponding optical network units and for outputting the subcarrier channels from the corresponding optical network units to the optical-to-electrical converter.