Hierarchical Optical Ring INterconnection (HORN): A scalable interconnection-network for multiprocessors and massively parallel systems

A new interconnection network for massively parallel computing is introduced. This network is called a Hierarchical Optical Ring INterconnection (HORN). HORN consists of a single-hop, scalable, constant degree, strictly non-blocking, fault-tolerant interconnection topology that utilizes Wavelength Division Multiple Access (WDMA) to provide better utilization of the terahertz (THz) bandwidth offered by optics. The proposed optical network integrates attractive features of hierarchical ring interconnections, e.g., simple node interface, constant node degree, better support for locality of reference, fault-tolerance, with the advantages of optics. This paper presents the HORN topology, analyzes its architectural properties and presents an optical design methodology for it. Furthermore, a brief feasibility study of HORN is conducted. The study shows that the topology is highly amenable to optical implementation using commercially available optical elements.