The future of optical networks is coherent and elastic: operators are deploying an all-coherent, multi-format network, leveraging DSP for modulation/demodulation and for mitigating several physical impairments. ORCHESTRA exploited these evolving trends by developing advanced DSP algorithms that extend existing optical transceivers and use them as soft-OPMs. In addition to typical monitored parameters, ORCHESTRA measures optical signal to noise ratio (OSNR) and filtering effects. A key difference is that, currently, monitoring is used by humans for troubleshooting, while ORCHESTRA uses it to automate network operation and optimization.
A soft-OPM at a receiver provides aggregate measures over a multi-link path. The ORCHESTRA optimization engine analyzes information from multiple soft-OPMs and other monitors (e.g. power monitors) and correlates that with routing information, to provide a variety of advanced capabilities, such as: accurate quality of transmission (QoT) estimation; anticipation, as well as detection and recovery from hard (total link) and soft (QoT degradation) failures.
ORCHESTRA developed a hierarchical control and monitoring infrastructure, extending the emerging ABNO architecture, enabling effective distributed processing of monitored information and fault management, avoiding bottlenecks in traditional centralized control. We developed a new resilience scheme, namely pre-programming, which, in contrast to typical centralized resilience, can be applied locally at the transceiver agents to achieve high re-action speed. NETCONF with appropriate YANG models was used for both monitoring and control functionalities.
ORCHESTRA relies on the feedback from soft-OPMs and developed a planning algorithm to provision lightpaths with reduced margins and operational algorithms to regulate the margins and maintain the efficiency high to continuously re-optimize the network.
Five use cases that harvest the benefits of ORCHESTRA were identified:
• Lightpaths provisioning with reduced margins
• Dynamic network adaptation
• Hard/soft-failure localization and handling
• Optimization during upgrade and maintenance tasks
• Alien lightpaths support
Overall, ORCHESTRA met all its objectives and completed successfully. Detailed technoeconomic studies quantified the benefits of ORCHESTRA when provisioning lightpaths with reduced margins. The added flexibility, the continuously optimized operation and the increased availability of ORCHESTRA network were demonstrated in joint lab experiments in Pisa (SSSA), Paris (NBL) and a field trial in Torino (TIM).
The outcomes of ORCHESTRA led to numerous publications in high impact journals and conferences. Solid progress was made in interactions with IETF and ITU standardization bodies, while the invention of pre-programming was patented.
The project objectives remain relevant and in-line with the partners’ roadmaps as well as with the work programme expected impacts. This is confirmed by the observed increased interest from major optical vendors, telecom operators, and the research community in the directions explored in ORCHESTRA.