Master Thesis - 2002

Ultra high-speed and wide-band networks will become necessary to provide highly advanced multimediaservices. However,it is hard to deploy fast and wide-band switchesusing electronic circuitsfrom viewpoints of cost and development techniques.All-optical networkswith the best use of high speed and bandwidth of lightwave are required.

The enlargement of band with low transmission loss has increased fiber capacity. In wavelength-routed networks which have been discussed so far, increase of wavelength paths makes switches complex. However, the present technology has a limit on developing large-scale switches. The scales of switches can be suppressed by switching aggregated wavelengths. The authors have proposed a waveband-routed network architecture where each waveband path has multiple wavelengths corresponding to the traffic demanded by the node pair.

This paper proposes aggregation of the paths sharing links for small-scale switches. A new wavelength assignment algorithm assigning consecutive wavelengths to the paths sharing links to reduce actively the scales of switches is also proposed. Maximizing capacity utilization is indispensable, so the algorithm is developed for minimizing both numbers of required wavelengths and switch ports, which conflict with each other.

Finally, the algorithm is applied to various networks and its performance is evaluated under various conditions over demultiplex capability of switches. Furthermore, effectiveness of waveband-routed networks is demonstrated.