A spectrum defragmentation strategy for service differentiation consideration in elastic optical networks

The spectrum fragmentation problem remains to be an open issue in elastic optical networks. In addition, the quality of service cannot be ignored during the transmission process. In this paper, we propose a novel spectrum defragmentation strategy considering the service differentiation, named SDSD, to improve the network performance in terms of the spectrum resources utilization, blocking probability (BP), and the set-up time for the serving connections. The presented results show that the proposed scheme can allocate the spectrum resources efficiently while decreasing the BP and connection set-up time. Moreover, the low grade services will be migrated preferentially during the phase of spectrum defragmentation, decreasing the number of migration.