Blocking probability in WDM switching networks with limited wavelength conversion

We study the benefits of wavelength conversion in all-optical WDM switching networks. In particular, we focus on investigating network performance improvement by using the more realistic limited wavelength conversion. We present an analytical model for calculating the blocking probability of WDM switching networks with limited wavelength conversion and validate the model through simulations. The analytical and simulation results reveal that a significant improvement in the blocking performance of the network can be achieved by limited wavelength conversion with small conversion degrees (e.g., d=2,3,4). We take the view that utilizing limited wavelength conversion with small conversion degrees in a WDM switching network is a more cost-effective choice.

I. Introduction

All-optical networks with wavelength division multiplexing (WDM), using wavelength routing, are considered to be candidates for future wide area backbone networks (WANs). In all-optical networks the data remain in the optical domain throughout their paths except at the ends. Such paths are termed as lightpaths. With wavelength routing, the lightpaths can be set up and taken down upon demand in a circuit-switched fashion.