Research On Routing And Core-spectrum Assignment Scheme And Application In Spatial Division Multiplexing Elastic Optical Networks

Traditional Wavelength Division Multiplexing(WDM)has a disadvantage of poor resource utilization doe to the fixed grid spectrum resource allocation.Elastic Optical Network(EON)has much finer frequency granularity which can provide flexible bandwidth provisioning and realize efficient spectrum resource utilization simultaneously.In order to further improve the transmission capacity of the optical network and the flexibility of service bearer capability,the combination of Multi-core fiber(MCF)based Space Division Multiplexing(SDM)technology and EON has been widely accepted as the promising technologies for future.The inter-core crosstalk and routing,core,and spectrum allocation scheme is one of the most concerns in spatial division multiplexing elastic optical networks(SDM-EON),which is researched with theoretical analysis and numerical simulation comprehensively.Firstly,some fundamental principles,architecture and key technologies of flexible optical networks are introduced comprehensively,followed are the analysis of the inter-core crosstalk(XT)and the routing,core,and spectrum allocation issues in SDM-EON,respectively.In order to solve the routing and resource allocation problem in SDM-EON dynamic traffic environment,the available spectrum resource(ASR)parameter is introduced to evaluate the availability of spectrum resources,and used as the basis for core selection and spectrum resource allocation.Consider the existence of inter-core crosstalk(XT)in multi-core optical fibers and its influence on quality of signal transmission,the spectrum status evaluation(SSE)is used to characterize the crosstalk and evaluate the RCSA algorithm candidate solutions.A combined routing and core-spectrum assignment scheme based on spectrum status(ASR-RCSA)is proposed in this thesis.In the process of spectrum resource allocation,SSE is used along with ASR to sort the spectrum resources and select frequency slots with more available resources and lower crosstalk for service allocation,respectively.Simulation results show that compared with FF-RCSA and RF-RCSA,the improved algorithm has obvious improvements in network blocking probability and spectrum resource utilization.According to the characteristics of inter-core crosstalk generated by adjacent cores,this thesis proposes an RCSA algorithm based on spectrum division scheme.This algorithm mainly relies on the classification of cores and spectrum blocking to optimize the spectrum resources and suppress crosstalk.The proposed improved algorithm will first search for in the priority area when executing core selecting and resource allocation.If there is available spectrum resource,the service can be directly provisoned and the influence of crosstalk is ignored;othewise it needs to find suitable resources in the common area,and performing spectrum allocation by calculating the possible crosstalk of the candidate allocation plan through SSE.Theoretical analysis and numerical simulation results can verify the effectiveness of the algorithm.