Researches on the Architecture of Multi-Serviced Optical Networks which Enables the Quality of Service Provisioning

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The purpose of this research is to study on the architecture of ultra high speed optical networks by focusing on the mechanisms that provide services with different quality levels through a common network platform, and propose efficient mechanisms for quality of service provisioning in optical networks. Towards this end, following studies have been carried out for two years.In Fiscal Year 2004, the first year of the research project, we have studied the mechanism for providing service differentiation in WDM based optical burst switching networks, which is a switching architecture proposed for the next generation optical networks. We have proposed wave-length scheduling algorithms that allocate wavelength to users based on their bandwidth usage during a certain period. In our algorithm, service differentiation is done by letting bursts in higher class preempt bursts in lower classes, or by dropping bursts which have over-usage of resources. Simulation results show that our schemes can p … More rovide efficient service differentiation in terms of burst loss rate, while burst preemption mechanism outperforms the non-preemptive one.In Fiscal Year 2005, we have developed the analytical methods for our proposed algorithms based on continuous Markov chain model. Comparison of the analytical results with simulations shows that our model is efficient when the burst length has Poisson distributions. Besides, we have studied on the mechanisms of providing absolute quality of service, which is another important feature for quality of service provisioning mechanisms. We proposed a preemption based burst scheduling algorithm that can guarantee the burst loss rate for classes with strict loss rate constraint. Our analytical and simulation results show that the proposed algorithm is efficient to provide loss guarantee for higher classes while suppress unnecessary drops for lower classes.The main contribution of this research is having adopted the quality of service provisioning notions and mechanisms into the new optical switching paradigm. Hopefully the outputs produced by this research will contribute as a part of the research and development of the new network architectures which enables the quality of service provisioning in high speed optical networks in the near future. Less