SCALABLE OPTICAL HYPERCUBE-BASED INTERCONNECTION NETWORK FOR MASSIVELY-PARALLEL COMPUTING

Two important parameters of a network for massively parallel computers are scalability and modularity. Scalability has two aspects: size and time (or generation). Size scalability refers to the property that th e size of the network can be increased with nominal effect on the exis ting configuration. Also, the increase in size is expected to result i n a linear increase in performance. Time scalability implies that the communication capabilities of a network should be large enough to supp ort the evolution of processing elements through generations. A modula r network enables the construction of a large network out of many smal ler ones. The lack of these two important parameters has limited the u se of certain types of interconnection networks in the area of massive ly parallel computers. We present a new modular optical interconnectio n network, called an optical multimesh hypercube (OMMH), which is both size and time scalable. The OMMH combines positive features of both t he hypercube (small diameter, high connectivity, symmetry, simple rout ing, and fault tolerance) and the torus (constant node degree and size scalability) networks. Also presented is a three-dimensional optical implementation of the OMMH network. A basic building block of the OMMH network is a hypercube module that is constructed with free-space opt ics to provide compact and high-density localized hypercube connection s. The OMMH network is then constructed by the connection of such basi c building blocks with multiwavelength optical fibers to realize torus connections. The proposed implementation methodology is intended to e xploit the advantages of both space-invariant free-space and multiwave length fiber-based optical interconnect technologies. The analysis of the proposed implementation shows that such a network is optically fea sible in terms of the physical size and the optical power budget.