Group-based spectrum assignment in dynamic flex-grid optical networks.

Highlights: [•] Flex-grid optical network is a promising solution to novel high speed services. [•] Spectrum continuity and contiguity constraints can induce spectrum fragmentation. [•] We propose a group-based spectrum assignment to solve fragmentation problem. [•] Spectrum is divided into groups and assigned to services according to their types. [•] Simulation results verify the efficiency of the proposed algorithm. [ABSTRACT FROM AUTHOR]