The Optimization Of The Optical Network Design, Based On The The Obs Integrated Hybrid Exchange

Nowadays, best effort traffic/IP traffic becomes dominance in communication networks. The underlying transport infrastructure is and will continue to be mainly composed of optical networks based on Wavelength Division Multiplexing (WDM) technology. Although the emergence of WDM opens up the Terahertz transmission bandwidth, the processing capability of the electronic parts of core routers leads to electronic bottlenecks, which restrict optical networks development. Three basic optical switching technologies in WDM networks have been proposed. Optical Circuit Switching (OCS) has high transmission efficiency, Optical Packet Switching (OPS) and Optical Burst Switching (OBS) can effectively accommodate dynamical/bursty traffic. The components needed for OPS are far from mature, which restrict the development of OPS. OBS is considered a good candidate for bursty traffic, but it is not a good one for steady traffic since OBS networks may have to drop bursts for contention even under steady traffic. In order to deal with challenge for uncertain traffic in optical network, some researchers turn to optimizing network performance by collaboratively combining the strengths of basic optical switching technologies and avoiding/reducing their weaknesses as much as possible.These existing hybrid models have problems such as virtual topology design, network realization, network resource utilization, etc. Therefore, the second chapter proposes a new hybrid switching solution, named OBS-based Integrated Hybrid Switching Optical Networks (OIHSON). OIHSON integrates OCS and OBS and utilizes high transmission efficiency of OCS and flexibility of OBS, which make OIHSON efficiently support network environment with bursty/dynamic traffic. Two layer topologies are designed for OIHSON, one is OCS part, and the other is OBS part. OCS part will carry steady part of traffic between routers, and the bursty/dynamic traffic which is beyond the OCS part's capacity will be accommodated by OBS one. When contentions appears in OBS part, collision traffic can switch back to OCS part if the latter happens to have enough resources, which can avoid dropping bursts for contention in OBS part as much as possible, and also improve resources utilization. The third chapter will introduce the overall optimization design of OIHSON. The research includes three perspectives: (1) Based the character of layered topology of OIHSON, it's better to segregate resources (wavelengths) used by OCS part from that used by OBS part, which can simplify OAM (Operation, Administration and Maintenance) and also decrease the complexity of OIHSON nodes. (2) OIHSON includes two layer topologies. OCS part will carry steady traffic between routers, and the bursty/dynamic traffic which is beyond the OCS part's capacity will be accommodated by OBS one. Based the method of segregating resources, two layer topologies can be designed seperatly. At the same time, the virtual design problem under uncertain model can be translated into static design problem under certain model. (3) Currently, network design only considers network being in operation, namely all resources are applicable and the network traffic is capable of transmission successfully. Therefore, the following part introduces capacity design of OIHSON in some scenes and the corresponding optimization models are given.To verify and evaluate performance of OIHSON, software simulation platform is designed. The simulation results given in chapter 4 verify OIHSON can efficiently carry bursty traffic, which realize anticipative purpose. The design details of simulation platform are given in chapter 5. The sixth chapter is conclusion of this dissertation.