An optical device for multiplexing both upstream and downstream optical signals in a single optical fiber. It comprises an optical fiber, signal transmitter, signal receiver, optical coupling lenses for both the transmitter and receiver, and an optical filter that demultiplexes transmission and receiving waves of different wavelengths.
*2: XG-PON OLT N2b
One of the FTTH optical communication standards established by ITU-T (International Telecommunication Union Telecommunication Standardization Sector). This standard specifies the configuration of a network that splits light from a local station and delivers the light to two or more subscribers at downstream and upstream speeds of 10 Gb/s and 2.5 Gb/s, respectively.