Survivable transparent OFDM optical grids/clouds: fragmentation aware, resource efficient protection with fast failure recovery

Due to high spectral efficiency and flexibility of orthogonal frequency division multiplexing (OFDM) technology, OFDM-based optical grids/clouds are fast replacing WDM grids/clouds. As grids and clouds process data intensive tasks, protection of optical grids and clouds from an arbitrary fiber-cut is extremely important. Employing a protection scheme leads to idle resource reservation, and data are continuously lost till protection (backup) paths become operational after a link failure. So, a protection scheme should not only minimize reservation of idle resources; it must also make the network recover quickly from a failure. In a dynamic scenario, another important issue is spectral fragmentation which leads to increased blocking of requests. In this paper, we address the problem of providing protection to OFDM-based transparent optical grids/clouds ensuring fast failure recovery with minimizing of both resource consumption and spectral fragmentation to the extent possible. To the best of our knowledge, this is the first paper to address the said problem for transparent OFDM optical grids/clouds. Performance comparisons show that the proposed polynomial time algorithm, fragmentation-aware resource-efficient protection with fast recovery (FRPFR) decreases spectrum utilization, decreases bandwidth blocking ratio and increases backup spectrum sharing by 27.88%, 35.37% and 35.94%, respectively, over algorithm protection with fast recovery (PFR) and by 11.95%, 20.29% and 14.35%, respectively, over algorithm resource-efficient protection with fast recovery (RPFR).