Towards 400G/1T flexible optical transport networks

In this paper, we describe the physical layer technologies, which should enable to still increase the global capacity of the currently deployed 100 Gbps WDM transmission systems, while making more flexible and more energy-efficient the optical transport networks. We address, in particular, the networks which will dynamically adapt their capacity to the service connection requirements, thanks to the appropriated allocation of spectrum resources and adaptation of modulation formats. In these flexible and energy-efficient optical transport networks, all-optical switching nodes will be able to add/drop not only the 400G/1T super-channels but also the sub-channels which constitute them, in order to lighten the load of the IP layer. Moreover, appropriated multi-layer network architectures should relax the capacity constraints weighing over the WDM transmission infrastructure.