Master Thesis - 2007

As a network traffic is increasing explosively, an expectation of large capacity optical WDM network has been growing. The optical WDM network has 2 types of switching system; OCS (Optical Circuit Switching), which is guaranteed service and OPS (Optical Packet Switching), which is best-effort one. However, next generation networks must provide both guaranteed and best-effort services for several types of application. For this reason, a hybrid network architecture using GMPLS has been proposed. It constructs the hierarchical network of optical path and packet. In such hierarchical network, WBS (WaveBand Switching) technology is also used in order to achieve a higher scalability of the number of wavelengths. In the WBS network, many consecutive wavelengths are grouped into a waveband and switched by each waveband. However, some wavebands cannot be fully utilized in the case of tucking many different demands into the partitioning space. Although several effective grouping methods have been proposed in the WBS network, some unused waves inevitably remain. Thus, it is necessary to utilize resources taking account of an architecture of the whole hierarchical network including waveband.

For this reason, a new hybrid network architecture of guaranteed WBS and best-effort OPS networks is proposed in this paper. The WBS network offers fragmental or surplus wavelengths to the OPS network after grouping its waveband. This optical path is used as a bypass in the OPS network. The architecture can improve a loss probability and throughput of the best-effort traffic. The effectiveness of the proposed architecture is confirmed through simulation experiments.