Defragmentation of fixed/flexible grid optical networks

This paper discusses the technical feasibility and network-level potential of defragmentation as a means of extending the capacity of optical transport networks. An experimental setup successfully demonstrates the possibility of rearranging connections spectrally in order to compact spectrum and harvest the benefits from more efficient flexible-grid channel formats. Furthermore, network simulations for fixed and flexible-grid formats highlight that the most promising cases for a full re-planning based defragmentation arise when the spectral mismatch between the different channel widths is more evident and when there are noticeable differences between the traffic patterns at different periods of the network life cycle.