A scalable optical WDM multicast Beneš network with multi-channel wavelength converters

Abstract

An optical wavelength division multiplexing (WDM) multicast network interconnects an input signal on a given wavelength to one or more output fibers, possibly on different wavelengths (via wavelength conversion), while maintaining the signal in the optical domain. A key challenge in the design of scalable multicast networks is to reduce conversion complexity without affecting the switching capability and signal quality. In this article, we propose a scalable WDM multicast Beneš interconnection network with minimized conversion complexity. The proposed network is based on the Copy-and-Route architecture, and it uses multichannel WCs (MCWCs) for wavelength conversion. The conversion complexity of the proposed design is O(F log 2 W ) (where F is the number of fibers and W is the number of wavelengths per fiber), which is smaller than the O(F W ) complexity of the optimal design based on conventional single-channel WCs (SCWCs). We prove that, for W > 64 and for any value of F, the conversion complexity of the new design is strictly less than that of the optimal SCWCbased design regardless of the total number of wavelengths simultaneously converted by each MCWCs. Analyzes of conversion complexity of the proposed design for large values of W confirm considerable savings compared to the optimal SCWC-based design. For instance, for W = 256 and an for an arbitrary value of F, a practical implementation of the proposed design achieves 87% reduction in conversion complexity as compared to the optimal SCWC-based design.