Minimum cost flow based R&WA algorithm for dispersion and OSNR limited all-optical networks

In transparent optical networks, the signal is directly switched in the optical domain without o-e-o regeneration. When considering high bit rate transmissions, uncompensated Chromatic Dispersion (CD) and Amplified Spontaneous Emission (ASE) noise accumulate along the fibers causing inter symbol interference and OSNR degradation. As a result, several connection requests are blocked for the low signal quality. We present a new dynamic Impairment Aware (IA)-RWA algorithm to reduce the impact of ASE noise and CD on the network blocking probability. Unlike other Impairment-Aware RWA algorithms, which normally separate the routing phase from the wavelength assignment, our approach uses a layered graph representation to solve the two subproblems simultaneously. Instead of using a shortest-path routing we run a minimum cost flow computation to find the maximum number of disjoint paths at the lower cost in the network. Finally, we select one of the paths considering the CD and BER requirements. We prove the effectiveness of our approach through extensive simulations and comparisons with other IA-RWA strategies.