Resource Allocation Algorithm Based on Dynamic Quantitative Impairment With Low-Fragmentation in SDM-EONs

Space division multiplexing elastic optical networks (SDM-EONs) is a promising solution to enhance the transmission capacity of optical networks. However, physical layer impairments (PLIs) degrade the service's quality of transmission (QoT). Additionally, service-differentiated spectrum demand leads to spectrum fragmentation, which is further aggravated by strict PLI constraints. Therefore, we propose a routing, core and spectrum allocation algorithm based on dynamic quantitative impairments for low fragmentation (QISEN-LowSF) in SDM-EONs. This algorithm quantitatively analysis multiple impairments and designs restrictive condition to weaken the fragmentation. Specifically, we design a path selection mechanism that takes transmission distance and integration degree of path resources as the cost metrics. Then, we abstract multiple impairment effects in core, and design a core selection mechanism at the cost of impairment estimation and resource integration of each core. When spectrum is allocated to the service, we design a reduced fragmentation spectrum allocation strategy based on the combination of quantified impairment with low-fragmentation. We also optimize the service impairment estimation model in the QoT calculation phase. The results show that QISEN-LowSF performs better than the comparison algorithms under different traffic loads. From the above, the QISEN-LowSF algorithm has superior dynamic flexibility and can reduce blocking probability and the resource fragmentation. Further, it can effectively handle various traffic loads.