Benefit Evaluation of All-Optical Subchannel Add–Drop in Flexible Optical Networks

Recent advances in switching technology have enabled the all-optical add/drop of low-rate signals to/from flexigrid superchannels empowering all-optical traffic grooming (AOTG) as an alternative to electronic grooming, e.g., OTN. This capability promises more efficient resource utilization and cost savings in future transport networks. To quantify the potential benefits of AOTG, in this paper, we carry out a thorough and holistic techno-economic analysis. We first review the AOTG-enabling technologies and then compare the performance of the AOTG-based solution with that of alternative optically transparent and OTN-based solutions in a planning scenario over a national-scale network in France. Our results show that AOTG outperforms benchmarks in terms of both spectrum utilization and cost, leading to ∼120% cumulative return of investment over a period of nine years and blocking-free network lifespan extension. Compared with the OTN-based solution, AOTG is demonstrated to bring up to 50% cost reduction.