A Novel Protection Guaranteed, Quality of Transmission Aware Routing and Wavelength Assignment Algorithm for All-optical Networks

Transparent All-Optical Networks carry huge traffic, and any link failure can cause the loss of gigabits of data; hence protection and its guarantee becomes necessary at the time of failure. Many protection schemes have been presented in the literature, but none speaks about protection guarantee. Also, in all optical networks, due to absence of regeneration capabilities, the physical layer impairments (PLI) accumulates along the lightpaths (LP) which causes sharp degradation of the Quality of Transmission (QoT), as measured by signal bit error rates (BER). The problem of protection with QoT issues has been rarely studied. In this work, a novel protection backup path ensured, QoT aware Routing and Wavelength Assignment (RWA) algorithm called “Virtual Lit –Exhaustive Highest Q factor” (V-Lit EHQ) is presented which exhibits desirable qualities for reliable network operation. The results of the proposed work are compared with the standard QoT aware versions of the Shortest Path (SP)-First Fit (FF) schemes as well as with literature for both lit and dark protection. The blocking probability (BP) and BER are taken as the performance metric and the proposed algorithm found to be outperforming as evidenced through simulations.