Impairment-aware Integrated Vone Scheme Based On Routing,bit Loading,and Spectrum Allocation In Eons

In recent years,with the rapid increase in bandwidth requirements of various applications,Internet traffic has increased exponentially,which has put forward higher requirements for spectral efficiency,flexibility and scalability in flexible optical networks.The combination of Elastic Optical Network(EON)and Optical Orthogonal Frequency Division Multiplexing(OFDM)enables network providers to meet the needs of heterogeneous bandwidth in the network.However,the mutual coupling between heterogeneous network resources has brought huge challenges to network resource scheduling.Therefore,the introduction of network virtualization technology has become an inevitable trend.Optical network virtualization is based on the concept of infrastructure as a service,which promotes the sharing of physical infrastructure between different users and applications,enabling network operators to efficiently provide their network resources as services.Generally speaking,network operators use virtual optical network embedded(VONE)to construct virtual optical networks(VONs),and allocate necessary resources in the physical infrastructure to each virtual optical network through node mapping and link mapping.In order to adapt to the high-speed increase in bandwidth requirements to achieve network optimization in EON,an efficient VONE algorithm is particularly important.At the same time,it is also essential to accurately understand the nonlinear impairment on each link.The nonlinear impairment directly affects the signal-tonoise ratio,the spectrum efficiency and capacity of the system.In previous work,an integrated VONE(iVONE)scheme has been proposed,in which node mapping and link mapping are embedded in an integrated manner.In this paper,we focus on the OFDM-based nonlinear virtual network mapping mechanism in EON.Firstly,an elastic optical network architecture with resource virtualization is proposed,which mainly includes a three-layer structure of physical layer,control layer and service layer and realizes the virtualization of spectrum resources and optical transceivers.Secondly,a novel integer linear programming model based on bit loading(BL-ILP)technology is derived,which ensure each subcarrier to be modulated independently.Meanwhile,an impairment-aware integrated VONE scheme based on bit loading technology(BL-iVONE)is designed,which can achieve the purpose of network optimization.The specific details will be provided.Next,we propose an impairment-aware integrated VONE scheme based on uniform modulation(UM-iVONE).This scheme establishes the physical network model,virtual network request model and VONE model based on nonlinear impairment.The corresponding VONE heuristic algorithm will be provided in paper.Finally,by comparing the BL-iVONE with the BL-ILP and the UM-iVONE for a full range of network performance comparisons,we can conclude that the BL-iVONE has significantly improved both in spectrum transmission efficiency and resource utilization optimization.This paper provides important routing,spectrum and modulator allocation schemes(RMSA)for VONE mechanism in EON,and achieves excellent results in terms of spectral efficiency and subcarrier utilization.It also provides further optimization of network architecture,which has significant theoretical guidance and practical value.