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 hierarchal 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.