OBS contention resolution performance

In this paper, a performance comparison of resolution policies specific to optical burst switching is presented. A framework, based on a reduced-load approximation, is developed to estimate path blocking probabilities in an optical burst switched network of arbitrary topology, in which any combination of the following resolution policies is applied in a specific order: limited wavelength conversion, burst deflection and burst segmentation. Our framework is used to compare the relative performance of each resolution policy for two sets of ingress and egress router pairs defined on the NSF network. With respect to the assumptions considered, it is shown that limited wavelength conversion is more effective in reducing blocking relative to burst deflection if the maximum wavelength conversion radius is sufficiently large, otherwise burst deflection is more effective. Furthermore, limited wavelength conversion or burst deflection are more effective in reducing blocking relative to burst segmentation. Burst segmentation is justified as a stand alone resolution policy; however, using burst segmentation to complement another resolution policy offers only a marginal reduction in blocking. Both just-in-time and just-enough-time scheduling is analyzed. Simulations are implemented to corroborate the accuracy of our framework and extensions. © 2006 Elsevier Ltd. All rights reserved.