Survivable multipath provisioning in OFDM-based flexible optical networks

OFDM-based flexible optical networks provide better spectral efficiency than conventional WDM optical networks as connections can be allocated requested capacity instead of full wavelength capacity. Survivability is an important issue in OFDM-based flexible optical networks. However, little work has been done in this area. In this study, we propose a survivable multipath provisioning scheme that provides flexible protection levels to individual connections in OFDM-based flexible optical networks. We define the static Survivable Multipath Routing and Spectrum Allocation (SM-RSA) problem which seeks to accommodate a given set of demands using multipath provisioning such that the utilized spectrum is minimized. We show that the static SM-RSA problem is NP-hard and present an efficient heuristic algorithm to solve the problem. Our simulation results show that the proposed multipath provisioning scheme achieves better spectral efficiency than the conventional single-path provisioning scheme.