Modular Architectures of Multistage Switching Networks

This paper defines a procedure for designing the architecture of multistage switching networks. Our proposal is the result of a systematic study of the properties of multistage networks on one side and of optical switching systems on the other side. Modularity of the implementation is the primary concern, allowing the construction of a generic-size fabric by the simple cascading of multiple-stage modules. In this paper, we show in detail the application of the approach to a family of banyan networks, although the method can be extended to other types of networks. The designed architecture can be exploited for various implementation technologies, for instance, integrated optics and free-space optics. The method can even be applied to electronic VLSI/ULSI circuits. After presenting the design procedure, we discuss practical implementations in different technology scenarios. The main contribution of this paper is to simplify the building of large switches by cascading a number of switching modules that combine the internal stage architecture with the interconnection between stages.