Quality of service enhancement in optical burst switching networks without full wavelength convension capability

Abstract

Optical burst switching (OBS) is a promising candidate technology for the next-generation of wavelength division multiplexed backbone transport networks. It is reasonable to assume non-full wavelength conversion capability in practical OBS networks since all-optical tunable wavelength converters (TWCs/WCs) are expensive and still immature technologically. Without full wavelength conversion capability to resolve contentions among bursts for output wavelengths, quality of service (QoS) enhancement intended to reduce burst loss becomes important. In this thesis, we present several QoS enhancement algorithms in OBS networks without full wavelength conversion capability. First, we propose an offline wavelength assignment algorithm in non-wavelength-convertible OBS networks where no WC is deployed at the core nodes. Next, we develop an algorithm for allocating WCs at the core nodes to form partially wavelength-convertible OBS networks. Finally, we propose two burst rescheduling algorithms to reduce the burst loss probability in a partially wavelength-convertible OBS network. The effectiveness of these algorithms is verified through simulation results.