PLI-Aware Routing in Regenerated Mesh Topology Optical Networks

Wavelength routing algorithms (WRAs) aware of Physical layer impairments (PLIs) have been proposed in order to manage the establishment of optical paths in wavelength-switched optical networks. However, if optical nodes incorporate regenerators/wavelength converters, PLI-aware WRAs should be devised in order to incorporate error accumulation in the signal in the PLI estimation and relaxation of the wavelength continuity constraint in the path calculation. In this paper, we utilize a new bit error rate performance estimation in combination with the PLI-aware WRA in order to systematically investigate the role of regeneration and wavelength conversion in optical networks. Based on the outcomes of the study, we also propose a path establishment algorithm that is based on the “instant” physical properties of the path and can dynamically adapt to the network state. This is proven beneficial as far as the blocking performance is concerned as it circumvents the weaknesses that appear in the traditional shortest distance path establishment algorithms in a PLI-aware environment that operates without the wavelength continuity constraint.