Self-Autonomous Multi-Carrier Optical Transmissions

In order to activate high-data-rate connectivity, super-channel transmission strategy is becoming a suitable solution. Optical Software Defined Networking (OSDN) architecture leverages NETCONF protocol for the configuration and management of optical devices. To support a vendor-neutral approach, OpenConfig YANG models are adopted in the NETCONF communication. In OpenConfig, all the proprietary parameters (i.e., Forward Error Correction (FEC), bit rate, modulation format) are mapped to operational modes, maintaining a basic compatibility between vendors. In this work, the experimental analysis of an automatic super-channel optimization is shown. In particular, for each established super-channel, the sub-carriers are partially overlapped and tightly filtered, achieving spectrum saving with margins reduction, while guaranteeing a level of Quality of Transmission (QoT). The procedure has been demonstrated using an SDN Controller with an SDN-based Optical Network, including OpenConfig 600 Gbit/s transponders and emulated ROADMs. After the setup of a lightpath, the optimization procedure is activated by the transponder agents, without involving the SDN controller, to find the optimal super-channel configuration, according to the reach and the desired modulation formats. A spectrum saving of 25% is achieved with respect to the nominal conditions, still guaranteeing the minimum QoT level for the channels involved, in terms of pre-FEC Bit Error Rate (BER).