Fragmentation assessment based on-line routing and spectrum allocation for intra-data-center networks with centralized control

• Two methods for assessing the spectrum fragmentation of a network are proposed.
• We perform on-line RSA applied using the proposed assessment methods.
• The proposed approaches allow solving the on-line RSA problem more efficiently.
• Performance of on-line RSA is applied to intra-data-center network with SDN control.

As is well known, elastic optical network is quite attractive due to its great spectral efficiency and flexibility, which can allocate appropriate size spectrum based on efficient modulation modes such as Orthogonal Frequency Division Multiplexing (OFDM) modulation, etc. These characters are able to better meet the needs of the intra-data-center optical interconnection. To properly analyze and operate elastic optical networks with highly dynamic traffic of the intra-data-center, considering the continuity constraint and the contiguity constraint, efficient methods are required for the on-line routing and spectrum allocation (RSA) issue. In this paper, we propose two methods (AFD and CSL) for assessing the status (spectrum fragmentation) of the network, and present two algorithms (BSPR and HSR) which use the proposed assessment value to perform on-line RSA applied to intra-data-center networks which adopt the Software-Defined Network (SDN) control mode. Simulation results reveal that the proposed approaches allow solving the on-line RSA problem more efficiently with lower blocking probability of the networks.