Lightpath Establishment in WDM Networks with Best Effort Shared Path Protection in Impaired-Transmissions

In wavelength division multiplexing (WDM) networks, failures can imply in great loss of data due to high transmission rates, leading to the need of employment of protection mechanisms. Transparency and switching in all-optical networks causes physical impairments, which can significantly degrade the signal quality. If the signal quality in a path is below acceptable values, this path cannot be used by incoming requests for lightpath establishment. Therefore, quality needs to be checked by the routing and wavelength assignment algorithm. This paper introduces two novel algorithms for shared path protection in WDM networks that take into account the PMD, ASE and homowavelength crosstalk physical impairments in path selection. The efficacy of these algorithms are compared to those of their impairment unaware counterpart.