Lightpath Establishment Assisted by Offline QoT Estimation in Transparent Optical Networks

We propose lightpath establishment techniques for transparent optical networks, valid for both centralized path computation (i.e., performed by a path computation element-PCE) and distributed path computation (i.e., performed by each ingress node). The proposed techniques rely on correlating the end-to-end quality of transmissions (QoT) (e.g., optical-to-signal-noise ratio-OSNR) of lightpaths already set up to evaluate the QoT of lightpaths to be established. The correlation is leveraged by two end-to-end estimation frameworks called “network kriging” and “norm l₂ minimization.” Each framework is used in turn to estimate end-to-end parameters that describe the QoT for a lightpath to be established, based on measured parameters from other lightpaths that were previously established or probed. Simulations are carried out for both PCE and distributed networking scenarios on a sample optical transparent network. The proposed lightpath establishment techniques reduce the probability that a setup attempt is unsuccessful due to unacceptable QoT and reduce the number of setup attempts to successfully establish lightpaths. Simulation results are also provided to show that our techniques permit a fast convergence of QoT information at PCE or ingress nodes in the context of dynamic networks.