Brown-field Gradual Migration Planning Toward Spectrally-Spatially Flexible Optical Networks

In this paper, we motivate a brown-field migration planning as a cost-efficient procedure to scale the capacity of short-term realizable elastic optical networks (EONs), gradually converting them into spectrally-spatially flexible optical networks (SS-FONs). After a formal statement of the brown-field EON to SS-FON migration planning problem, a Stochastic Iterated Local Search (SILS) metaheuristic is presented to solve it in realistic time-scales. Using the proposed metaheuristic, we study the migration of two different reference backbone EONs to SS-FONs based in realistic traffic forecasts up to year 2031, accounting for both unicast and anycast traffic types. The obtained results also serve to highlight the good performance of the proposed SILS metaheuristic versus alternative heuristic approaches used as benchmark.