Abstract: A method includes, for each optical fiber path in an optical network, allocating an optical wavelength channel in an optical spectrum such that the allocated optical wavelength channel is assigned to support optical communications over the optical fiber path. The method also includes updating an allocation table in response to performing the allocating for one or more of the optical fiber paths; the allocating including determining the optical wavelength channel to be allocated based on a state of the allocation table. The allocation table indicates optical wavelength channels allocated over optical fiber spans of the optical network. The method also includes defining a set of optical sub-bands to cover a part of the optical spectrum in response to a state of the allocation table satisfying a fullness property. The optical sub-bands are such that each of the allocated wavelength channels is in one of the optical sub-bands.

Abstract: A host device is provided that can leverage multiple optical modulation scheme capabilities of the optical module. The host device comprises an electrical modulator unit configured to generate electrical transmit signals comprising modulated data in a modulation format, and a connector configured to connect to the optical module that transmits optical signals to an optical fiber. The host device comprises a controller that is configured to select one of a plurality of optical modulation schemes for an optical reach, and to generate a control signal for supply to the optical module via the connector. The control signal is configured to cause the optical module to generate optical signals from the electrical transmit signals according to the selected optical modulation scheme.