Survivable Transparent OFDM Optical Grids/Clouds: Efficient Dynamic Route Selection with Minimized Spectral Fragmentation

As Orthogonal Frequency Division Multiplexing (OFDM) allows flexible spectrum allocation, today's optical grids/clouds are OFDM based. Survivability is an important issue since timely execution and delivery of jobs(services) are extremely important for optical grids(clouds). Spectral fragmentation is another key issue in a dynamic scenario resulting from random arrival and departure of requests. In this paper, we address the problem of survivability of transparent OFDM optical grids/clouds with the joint objective of minimizing utilized spectrum index and spectral fragmentation in routing paths for dynamic traffic. To the best of our knowledge, this is the first paper to address the problem of survivability of transparent OFDM optical grids/clouds with the said objective. The proposed algorithm SIA-SRSA-MF (Spectrum Index Aware Survivable Routing and Spectrum Allocation with Minimized Fragmentation) runs in polynomial time. Performance comparisons with other algorithms show appreciable reduction in bandwidth blocking ratio.