Dynamic Routing and Spectrum Assignment Algorithm Based on Differentiated Degraded-service and Adaptive Modulation in Elastic Optical Networks

Oriented to the high-rapid development of Internet applications, new challenges are encountered by the conventional Routing and Spectrum Assignment (RSA). A new direction for the blocking rate reduction and the Quality of Experience (QoE) assurance is provided to the Elastic Optical Network (EON) integrated by Degraded Service (DS) technology. Due to the inefficiency of spectrum resources and the revenue decline caused by DS, a Mixed Integer Linear Programming (MILP) model is proposed with a joint objective that minimizes both spectrum consumption and the priorities and DS frequency of online services. A dynamic RSA algorithm based on differentiated DS and adaptive modulation is proposed, which considers service-priority differentiation, the adaptive modulation and DS technology. Meanwhile, DS loss function and DS window selection strategy are designed to differentiate service levels, and ideal spectrum location and resource are assigned for the impending blocked services. The network revenue function considering the relationship between spectrum and revenue balance is designed to achieve efficient utilization of spectrum resources, reduce the impact of degradation, and enhance network revenue. The simulation results verify the advantages of the proposed algorithm in terms of blocking rate, network profit, etc.