Spatial Channel Cross-Connect Architectures for Spatial Channel Networks

A spatial channel network (SCN) is a novel optical network architecture targeting the space division multiplexing (SDM) era where the optical layer is explicitly evolved into the hierarchical SDM layer and wavelength division multiplexing layer, and an optical node is decoupled into a spatial channel cross-connect (SXC) and a wavelength cross-connect to form a hierarchical optical cross-connect. In this article, we discuss a wide variety of SXC architectures based on optical matrix switches (MSs) and newly proposed core selective switches (CSSs) from the viewpoints of connection flexibility and architectural complexity. After briefly reviewing the architecture and functionalities of an SCN and its building-block optical devices, novel SXC architectures based on sub-MSs and CSSs are described and formulas are derived for each SXC architecture that give the required number of optical devices, switching mirrors, and internal fiber connections. Based on the formulations, these architectures are compared with traditional SXC architectures based on a high-port count full-MS pair and a Clos network from the viewpoints of the freedom of connection functionalities, operational benefits, and potential node costs associated with the architectural complexity in order to obtain insights regarding which network application is suited to each SXC architecture.