Research On Optical Network Optimization Algorithm Based On Waveband Switching

With the emergence of new broadband Internet application services,such as high-definition digital TV,cloud computing,e-commerce and multimedia,optical communication network is developing towards the direction of large capacity and large data flow.Accordingly,optical communication networks require more wavelength resources to carry the service.The problem of limited switching scale and high switching cost of optical network is becoming more and more obvious.At present,the number of ports are commercially available is limited to about 20+ and the price is high.In recent years,waveband switching(WBS)has attracted the attention of researchers in the optical network industry.It has great significance in reducing the number of optical switching ports,controlling the complexity of switching and the cost of optical cross connect(OXCs).Researchers at Nagoya University have proposed a new network structure for waveband switching.Based on the network structure,the upper and lower traffic demands are carried out through the operation of WSS on the access port,while other businesses use the internal waveband switching matrix WBXC to switch the waveband granularity level.Therefore,the structure makes the port size limited WSS,still can constitute a large scale of switching nodes.Based on this structure,this paper studies the waveband switching,and focuses on the study of the waveband switching strategy based on the sub-path inclusion relationship.This paper first introduces the research background and development status of WDM network and EON network,and expounds the key technologies related to WDM and EON.Secondly,aiming at the optimization problem of WDM optical network based on waveband switching,we use the simulation platform built by ILPG CPLEX and VS2010,and compare the ILP algorithm of waveband switching and non-waveband switching.The simulation results show that the ILP algorithm based on waveband switching can significantly reduce the number of interconnected ports in the network compared with the non-waveband switching algorithm.In view of the complexity of ILP algorithm,it can not be applied to the problem of large traffic and large scale network.This paper proposes two heuristic algorithms: BP-WN algorithm and BP-BR algorithm.In the six node network,compared with the results of the ILP algorithm,the performance of the heuristic algorithm is close to the optimal solution of the ILP algorithm.Further,the optimization effect of the heuristic algorithm on the OXCs port in the 11 node COST239 network is verified on the simulation platform.Then,aiming at the optimization problem of EON port number in elastic optical network based on waveband switching and adaptive modulation format,we propose an adaptive modulation format AM-WBS-RSA-ILP model algorithm.The simulation results show that with the increase of the number of requests,compared with the single modulation format S-WBS-RSA-ILP algorithm,the ILP algorithm based on waveband switching can significantly reduce the scale of switching and route more business connection requests.Aiming at the problem of large-scale network and large traffic,two heuristic algorithms are proposed: S-WBS-RSA-H algorithm and AM-WBS-RSA-H algorithm.Simulation results show that the heuristic algorithm is close to the network performance of ILP algorithm.On this basis,this paper further uses the heuristic algorithm to simulate and analyze the port number of the COST239 topology network.The results show that compared with the single modulation format S-WBS-RSA-H heuristic algorithm based on wave band switching,with the increase of traffic volume,the advantage of AM-WBS-RSA-H algorithm is more obvious.The adaptive modulation format of wave band path distance is adopted to reduce the size of optical switching ports and make full use of optical spectrum resources to improve the flexibility of the network.Finally,the research work of this paper is summarized and prospected.