A transmission device includes a symbol generator that generates a modulation symbol by mapping transmission data to a signal point arranged in a two-dimensional or three-dimensional color space; and an outputter that outputs an optical signal modulated according to the modulation symbol.

A system for delivering multiple passive optical network services is disclosed. The system includes a first optical transmission service comprising a common wavelength pair routed from a source to each of a plurality of subscribers. The system further includes a second optical transmission service comprising a plurality of unique wavelength pairs, where each of the unique wavelength pairs is routed from the source to a subscriber among the plurality of subscribers. The system delivers the first optical transmission service and the second optical transmission service to the subscriber on a single optical fiber.