Online physical-layer impairment-aware routing with quality of transmission constraints in translucent optical networks

We propose a novel online physical-layer impairment-aware routing algorithm taking into account a minimum quality of transmission (QoT) constraint, which must be satisfied in all cases, even if the network load is changing, and new channels are activated. Our online constraint-based routing (CBR) algorithm considers the actual network load to get a more exact prediction of the signal quality degradation due to (multi-channel) nonlinear fiber impairments. We present results showing that the proposed online CBR algorithm is superior to shortest path routing with maximum transparent distance constraints as well as offline CBR algorithms, which are based on worst-case Q-factor penalties, in terms of blocking probability.