Strictly Nonblocking $f$-Cast Photonic Networks

The multicast capability and crosstalk issue need to be deliberately considered in the design of future high performance photonic switching networks. In this paper, we focus on the photonic switching networks built on the banyan-based architecture and directional coupler technology. We explore the capability of these networks to support general f-cast traffic, which covers the unicast traffic (f = 1) and multicast traffic (f = N) as special cases, and determine the conditions for these networks to be f-cast strictly nonblocking under various crosstalk constraints. In particular, we propose an optimization framework to determine the nonblocking condition of an f-cast photonic network when a general crosstalk constraint is imposed.