Research On Spectrum Allocation And Sub-Band Virtual Concatention In Elastic Optical Networks

The traditional WDM optical network divides the spectrum into fixed grids,which easily cause the waste of spectrum resource and flexibility is poor.In order to meet the needs of the future network,optical transmission and network technologies urgently need to be more efficient,more volatile and scalable.Elastic Optical Network(EON)can divide spectrum into narrow slots and has the flexiblity of distributing the bandwidth.As a result,network utilization efficiency is greatly improved compared to WDM optical network.In this paper,spectrum allocation algorithm and sub-band virtual concatenation technique(VCAT)for elastic optical network are studied in detail by theoretical analysis and numerical simulation.This paper starts with a introduction of the concept,unique characteristics and the architecture of the elastic optical network.Then it moves to the concept and spectrum allocation approaches of routing and spectrum algorithms in detail.Meanwhile,the basic concepts of VCAT in the time and frequency domains are introduced.As for the distance-adaptive technology in the elastic optical network,a segmentation modulation based spectral allocation scheme considering the central nodes(CC-SM)is proposed.This algorithm can reduce the distance of each segment by guiding the service to the central nodes for segment transmission,and using high level modulation.The simulation results show that compared to the non-segmentation modulation scheme,the CC-SM algorithm improves the utilization of network resources.Thereafter,based on the application and evolution of optical networks,the paper discusses the practical application of improved algorithm.Aiming at the problem of optical network availability,then the paper presents a spectrum allocation algorithm based on failure bandwidth equal(FBE-RSA)algorithm and supported by VCAT.This algorithm adpots the VCAT to split the large service into small services for transmission with the faluire bandwidth equal spectrum allocation method,thus increasing the availability of the network.Network simulation results show that with non-VCAT schenario and average bandwidth algorithm,FBE-RSA algorithm has some advantages in improving network availability and spectrum resource utilization.