Research On Software Defined Optical Network Resource Virtualiztion And Controlling Mechanism

With the rapid development of Internet technology,optical networks are undergoing major changes in the transmission layer and control layer.Nowadays,software defined optical network is inevitably facing new challenges such as software defined equipment,network virtualization,network function virtualization and multi-layer multi-domain communication.Therefore,how to optimize the virtual network resource allocation,and improve the control mechanism of network function,to make the software define optical network more flexible and efficient,have become a key research topic.Based on software defined optical network,this doctoral dissertation intensivly studies on several aspects such as resource allocation algorithms,resource virtualization,and design of control and implementation scheme for flexible control layer.The main work and innovative contributions are listed as follows:(1)Energy-efficient modulation scheme(EEMS)is proposed.To solve the problem of routing,modulation level and spectrum assignment(RMLSA),an energy-efficient modulation scheme is proposed.The scheme aims to find the lowest modulation level to reduce the power consumption,avoiding to affect the spectrum usage.The results of numerical simulation indicate that,comparing with traditional scheme,EEMS scheme reduces the power consumption by 3.8%without impacting the blocking ratio and spectrum utilization.(2)Asymmetric resources assignment method in software defined optical network is proposed.Since traffic demands may be asymmetrical,the symmetric resource assignment method cannot make full use of network resource.In order to solve the problem,this dissertation proposes asymmetric resources assignment method.This dissertation analyzes the feasibility of asymmetric resources assignment,then introduces the several asymmetric assignment methods.Then an asymmetric modulation and spectrum assignment algorithm is proposed.The simulation results show that asymmetric resource assignment method can significantly reduce blocking probability and improve spectrum utilization ratio.Finally,a SDON experimental test-bed is built to realize the asymmetric resource assignment schemes.The experimental results show that asymmetric resource assignment can optimize network resource allocation.(3)Service-oriented software defined optical network is proposed.For service differentiation,a service-oriented software defined optical network is proposed to satisfy traffic demands.In this dissertation,the service chain is extended to the optical layer,and some specific functions in the optical network(such as path protection,multicast,transmission quality control and constraint routing,etc.)can be decoupled as an independent virtualization network function module for traffic.Then,the service-oriented software defined optical network and the functions of the each layer are described.Besides,some optical services are defined.In order to improve the ability of optical network nodes to provide services,this dissertation designs and builds a service variable optical equipment(SVOE),and extends the OpenFlow protocol.Finally,the feasibility and effectiveness of the service-oriented software defined optical network is verified through the network experiment.(4)A multi-layer recovery scheme is proposed.For the network survivability problem,a multi-layer recovery scheme is proposed to recover the optical layer service quickly when the link failure occurs in the optical network.This scheme can reduce the rerouting and shorten the recovery time.The network experiment is conducted based on the service-oriented software defined optical network.The results of the IP layer restoration and the optical layer restoration are demonstrated through two steps.The feasibility and effectiveness of the service-oriented multi-layer restoration scheme are verified.