Effect of wavelength converter density on the blocking performance of all-optical networks

Wavelength-routing networks have been proposed as a more feasible alternative to broadcast-and-select networks for all-optical information transport in the wide area. Of particular interest in the study of wavelength-routing networks is the analysis of blocking probability for circuit-switched networks. Recent work in this area has focused on finding the effect of wavelength converters (devices capable of converting any wavelength to any other) and path length on the session blocking probability in some regular topologies in the presence and absence of converters. Regular topology models are inappropriate for a WAN. Moreover, since wavelength converters are likely to be expensive devices, a practical scenario is one in which wavelength conversion is provided in a few selected nodes. In this paper, we propose a network model that is appropriate for a WAN and analytically evaluate the approximate blocking probability.