Joint Fragmentation- and QoT-Aware RBMSA in Dynamic Multi-Band Elastic Optical Networks

Efficient utilization of fiber bandwidth is essential for reducing the total cost of ownership associated with deploying new fiber plants. One of the challenges in dynamic multi-band elastic optical networks (DMB-EONs) is spectrum fragmentation. It stems from the wavelength continuity constraint, the dynamic arrival and departure of service requests, and variations in quality of transmission (QoT) across the wavelength division multiplexing (WDM) channels. This study introduces a QoT-aware algorithm for routing, band, modulation format and spectrum assignment (RBMSA) that considers the spectrum fragmentation along each channel to reduce service blocking ratio (SBR) in DMB-EONs. Simulation results indicate that the proposed algorithm reduces SBR by up to 33.2% compared to a reference RBMSA algorithm that considers only QoT at the cost of increasing the average path length by 4.4%.