Fixed-Alternate Routing and Wavelength Conversion in Wavelength-Routed Optical Networks

This paper considers optical networks which employ wavelength-routing switches that enable the establishment of wavelength-division-multiplexed (WDM) connections between node-pairs. In such networks, when there is no wavelength conversion, a connection is constrained to be on the same wavelength channel along its route. Alternate routing improves the blocking performance of such networks by providing multiple possible paths between node-pairs. Wavelength conversion improves the blocking performance of such networks by allowing a connection to use different wavelengths along its route. This paper proposes an approximate computational model that incorporates alternate routing and wavelength conversion. The model is shown to give reasonably good estimates of different parameters in the network including the blocking probability and link utilizations. This paper performs empirical studies based on discrete-event simulation, of the relationships between alternate routing and wavelength conv..