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. 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 sparse wavelength conversion. The model is shown to give reasonably good estimates of different network parameters. Empirical studies based on discrete-event simulation, illustrate the importance of alternate routing in improving the blocking performance of a wavelength-routed optical network