An improved dynamic wavelength assignment in statistical UDWDM-PONs

Dynamic wavelength assignment (DWA) is investigated for managing ultra-dense wavelength division multiplexing-passive optical networks (UDWDM-PONs). The optical network units (ONUs) own lasers under limited thermal tunability and their wavelengths have random distribution in a band. ONU and optical line terminal (OLT) architectures with coherent transceivers are proposed, providing a spectral efficiency suitable for a high capacity PON with large number of users and long-reach approach. In activation processes, ONU acceptances up to 99.99% are obtained with a DWA technique. Under standard environmental conditions, the DWA method is combined with guard bands and then ONU blocking probabilities below 0.1% and availability ratios up to 99.99% are achieved.