Optimization of extreme optical links for network upgrades

The continuous exponential growth of the demand for more bandwidth is driving network operators to upgrade current installed network infrastructure. In this way, many links will be upgraded from 10G to 40G and 100G. However, the higher optical signal-to-noise ratio (OSNR) demands for the upgraded links might limit the transmission in long haul scenarios, such as submarine links, where the available OSNR margin is very low. This paper presents optimization scenarios and techniques, based on realistic data, where it is shown that without optimization of the transmission parameters, the upgrade would not be viable.