A new clos-type model of wide-sense nonblocking multicast WDM optical switching network

As optical networking becomes a promising choice to meet the ever-increasing demands on bandwidth, constructing multicast wavelength division multiplexing (WDM) switching networks with cheap components and low complexity is a key issue. On the basis of four-stage Clos network, we propose an optimal model of wide-sense nonblocking multicast (WSNBM) WDM optical switching networks. Our analysis shows that the proposed model reduces hardware complexity compared to existing architectures. In addition, the new model has a very simple routing algorithm and does not require multicast capability for the switches in the input stage and the second middle stage. Therefore, our model is much more cost-effective and thus practical for both optical circuit-switching and optical packet/burst switching.