Passive optical network of bus structure

A passive optical network having a bus-type structure, the passive optical network comprising:

• a central office for wavelength-division multiplexing a plurality of time-division multiplexed downstream optical signals with mutually different wavelengths and receiving upstream optical signals;
• a plurality of remote nodes positioned in series on the optical path linked to the central office and including:
• an add/drop multiplexer for extracting selected ones of the multiplexed downstream optical signal with a corresponding wavelength and outputting the upstream optical signal to the central office;
• a downstream optical splitter for splitting the selected downstream optical signal into a plurality of downstream channels, and an upstream optical splitter for outputting a plurality of upstream channels by time-division multiplexing the upstream channels into an upstream optical signal, respectively;
• and
• a plurality of optical network units for detecting a corresponding downstream channel and linked with a corresponding remote node in order to transmit each of upstream channels to the corresponding remote node.