Research On Routing And Optical Code Allocation Strategy In Multi-layer And Multi-granularity Optical Switching Network

With the increasing of the traffic volume in the communication network,the requirements of network structure and the performance of the transmission system are getting higher and higher.There are many problems in communication network,such as traffic blocking and resource waste such as wavelength and optical code.Therefore,it is particularly important to choose the best path for traffic grooming and adopt efficient and reasonable resource allocation methods for reducing the blocking rate of optical switching networks,improving the utilization rate of optical code resources and avoiding the generation of optical code fragments.This paper carries out research on this,and the specific contents are as follows:First of all,existing optical switching networks have problems such as lack of programming,high operating cost and complex operation.GMPLS technology,PCE technology and Software Defined Network(SDN)are added into the optical switching network to form a multi-layer and multi-granularity optical switching network architecture.The architecture can avoid the above problems.Therefore,based on this architecture,this paper studies routing and optical code allocation in optical switching networks.Then,optical code fragmentation is easy to appear on the wavelength in the resource allocation process,and the routing and optical code allocation of subsequent services should be combined with the optical code fragmentation of the current link situation.Therefore,it is necessary to evaluate the optical code fragmentation in the current link first.Therefore,an optical code fragmentation evaluation scheme based on Difference of Services Similarity(DSS)is proposed.Among them,DSS value can reflect the degree of optical code fragmentation in the wavelength.According to the evaluation scheme,the routing algorithm based on service similarity difference(DSS-R)is proposed.By comparing the wavelength DSS values in different paths,the algorithm selects the most appropriate path transmission service,which can effectively reduce the blocking rate and improve the utilization rate of optical code resources.Finally,a Fragmentation algorithm based on Fragmentation Recombination Strategy of Optical code Assignment(FRS-OCA)is proposed to tackle the problem of new Fragmentation in service establishment.By comparing the size of service request and optical code fragment,the algorithm can first reorganize the fragment and finally establish the service,which can also reduce the blocking rate,improve the utilization rate of optical code resource and avoid the generation of new optical code fragment.