Loss Differentiation in OBS Networks With Limited or No Wavelength Conversion

Quality of Service differentiation is an open research issue in optical burst switching (OBS) networks. Most proposals assume full wavelength-conversion, but wavelength converters are still very complex and expensive, and accordingly limited and no wavelength conversion OBS networks are likely to be the most common scenarios. In this paper, we define and analyze the QoS Multiple Wavelength Simultaneous Transmission technique (QoS-MWST), a novel method for providing loss differentiation in OBS networks with limited or no wavelength-conversion capability. In QoS-MWST, multiple copies of each burst are simultaneously sent on different wavelengths, so as to increase the chances of data delivery, and loss differentiation is achieved by properly sending more copies of the higher-priority bursts. Through analysis and extensive simulation experiments, we demonstrate that QoS-MWST can provide loss differentiation in OBS networks without full wavelength-conversion capability more efficiently than other differentiation techniques proposed in the literature.