Research On Resource Allocation In Virtual Elastic Optical Network

With the rapid development of the Internet,the network architecture has exposed many problems which is a called as rigidity.Network virtualization is considered as an efficient method to overcome the problem of the Internet's rigidity,in which the network service provider(ISP)can be separated,multiple heterogeneous virtual networks are allowed to share a single underlying physical network.Therefore,Network virtualization greatly improves the utilization of physical infrastructure.On the other hand,with the optical orthogonal frequency division multiplexing(OOFDM)technology,elastic optical networks(EONs)are regarded as a promising next-generation approach.Furthermore,extensive literature demonstrate that EONs are emerging as a are emerging as a prospective technology for virtualization in the optical networks from the viewpoint of elastic networking level to sliceable equipment level.Virtualization in EONs brings many challenges and problems.As one of the essential challenges,the resource assignment technology to virtual optical network(VON)is to assign substrate network resources to the VON requests,which is also named as VON mapping problem.In this paper,we categorize the problem of resource allocation to VON into transparent and opaque scenarios,and design algorithms for resource allocation to both transparent and opaque VON in EONs according to the characteristics of the network.The main work and innovations are as follows:First,resource assignment problems become more restrictive for transparent virtual network resource allocation algorithm in EONs.In order to improve the efficiency of algorithm,we define the node effective degree,and design a resource assignment algorithm to virtual nodes based on the effective degree.Then,we utilize layered-auxiliary-graph(LAG)approach for the resource assignment to virtual links.Integrating the two sub algorithms,we design a transparent virtual network resource assignment algorithm based on the effective degree.Second,for opaque virtual network resource assignment algorithm in EONs,we introduce the concept of spectrum consecutiveness which can reflect the size and consecutiveness of the free spectrum resource in physical links or physical paths,and design an opaque virtual network resource assignment algorithm based on the spectrum consecutiveness in EONs.The algorithm considers the consecutiveness of available spectrum in physical links for the resource assignment to virtual nodes,and pays attention to the spectrum fragmentation for the resource assignment to virtual links.Extensive simulations are conducted and the results show that our proposed algorithms both have better performance of blocking probability and revenue-to-cost ratio than current algorithms.