Toward Plug-and-Play Software-Defined Elastic Optical Networks

Advances in transmission technologies and control plane solutions are driving the introduction of spectrally-efficient ultrahigh rate superchannel transmissions. Modulation format, forward error correction/coding, and carrier spacing represent the key transmission parameters to configure in order to obtain efficient network resource utilization according to the specific optical path requirements. So far, several studies have mainly addressed the efficient configuration of a single selected transmission parameter. Instead, the topic of the combined configuration of the whole set of parameters still requires significant investigations, particularly in the case of automatic configuration procedures. In this study, we first review the aforementioned transmission parameters in terms of their adaptation capabilities. Then, a novel procedure for effective configuration of the whole set of transmission parameters is presented. The procedure, besides modulation format and coding configuration, includes a novel self-adaptation technique for the carrier spacing in a superchannel transmission. Moreover, the technique relies on a novel software-defined networking control to reoptimize the superchannel frequency slot width. The technique has been successfully validated in a field trial where a 1 Tb/s superchannel of eight subcarriers has been automatically adapted from a frequency slot width of 200 GHz to a more efficient slot width of 175 GHz, without traffic disruption.