Summary

Supplement 64 to ITU-T G-series Recommendations describes characteristics of optical transmission above 10 Gbit/s per wavelength between the optical line termination (OLT) and the optical network unit (ONU). It reviews challenges of transmission above 10 Gbit/s in optical access. A set of assumed system requirements is developed as a basis for the discussion of candidate technologies. Some aspects considered include signal modulation selection, optical transmitter design, optical receiver design, and wavelength dependency. Coexistence with other optical access systems is also investigated as a key factor of wavelength planning.

The line rate per wavelength in the existing PON systems, such as GPON, XG(S)-PON, TWDM-PON, is up to 10 Gbit/s. For High-speed PON, line rate per wavelength will exceed 10 Gbit/s, in order to provide higher bandwidth capability for growing services' requirement.