Migration steps towards flexi-grid networks

This paper first identifies a realistic expectation of modulation formats for the next 10 years and quantifies the possible capacity gains. It is studied when the capacity using fixed grid is exhausted and studies several evolution strategies towards flexi-grid. Results show the capacity will be exhausted by 2019 and by applying flexi-grid the network life can be extended five years. A shorter-term rationale to migrate to flexi-grid is the availability of cost-effective 400Gbps and 1Tbps transmission.