Research On Spectrum Allocation Algorithm Of Space-division Multiplexing Elastic Optical Network Based On Multicore Fibers

Diversified high bandwidth services such as big data,cloud computing,live webcast,telemedicine and online education are rising rapidly.The service transmission rate carried by single core optical fiber in traditional optical network is approaching the physical limit,which puts forward higher and higher requirements for network capacity and resource allocation.In order to meet the needs of various new services,space division multiplexing elastic optical network(SDM-EON)based on multi-core fiber(MCF)has attracted extensive attention.SDM-EON has the advantages of high flexibility,high spectrum utilization and large capacity.It is one of the long-term development directions of optical network in the future.However,it also has some key problems,such as spectrum fragmentation and inter core crosstalk.Therefore,these problems in SDM-EON are deeply studied through theoretical analysis and experimental simulation.Firstly,the basic principle,architecture of EON and space division multiplexing technology are introduced,and two key problems of spectrum allocation in SDM-EON are analyzed in detail.Aiming at the problem of spectrum fragmentation,this paper proposes an algorithm based on spectrum block damage degree and spectrum consecutiveness to avoid fragmentation.The basic idea of the algorithm is to comprehensively consider the damage degree of the allocation scheme to the current free spectrum block and the impact of the allocation on the spectrum consecutiveness of the whole link when allocating spectrum resources,and select the optimal scheme.The simulation results show that under the two network topologies of NSFNET and USNET,the proposed algorithm can significantly reduce the number of spectrum fragments and then reduce the bandwidth blocking rate compared with the First Fit(FF)algorithm and Random Fit(RF)algorithm.Aiming at the problem of inter core crosstalk,a crosstalk-aware spectrum allocation algorithm for SDM-EON is proposed.The basic idea of the algorithm is to avoid the crosstalk within a single request and between requests when allocating spectrum resources for service requests.Numerical simulation results show that in NSFNET and USNET network topologies,the proposed algorithm can effectively improve the crosstalk problem while maintaining a low level of bandwidth blocking rate.