Experimental demonstration of the optical multi-mesh hypercube: scaleable interconnection network for multiprocessors and multicomputers

Abstract

A prototype of a novel topology for scaleable optical interconnection networks called the optical multi-mesh hypercube (OMMH) is experimentally demonstrated to as high as a 150-Mbit/s data rate (2(7) - 1 nonreturn-to-zero pseudo-random data pattern) at a bit error rate of 10(-13)/link by the use of commercially available devices. OMMH is a scaleable network [Appl. Opt. 33, 7558 (1994); J. Lightwave Technol. 12, 704 (1994)] architecture that combines the positive features of the hypercube (small diameter, connectivity, symmetry, simple routing, and fault tolerance) and the mesh (constant node degree and size scaleability). The optical implementation method is divided into two levels: high-density local connections for the hypercube modules, and high-bit-rate, low-density, long connections for the mesh links connecting the hypercube modules. Free-space imaging systems utilizing vertical-cavity surface-emitting laser (VCSEL) arrays, lenslet arrays, space-invariant holographic techniques, and photodiode arrays are demonstrated for the local connections. Optobus fiber interconnects from Motorola are used for the long-distance connections. The OMMH was optimized to operate at the data rate of Motorola's Optobus (10-bit-wide, VCSEL-based bidirectional data interconnects at 150 Mbits/s). Difficulties encountered included the varying fan-out efficiencies of the different orders of the hologram, misalignment sensitivity of the free-space links, low power (1 mW) of the individual VCSEL's, and noise.

A spanning multichannel linked hypercube: a gradually scalable optical interconnection network for massively parallel computing

“…The HOE provides the connection patterns required for the three-cube. The hypercube modules have been experimentally implemented in the lab [20]. Issues relating to actual fabrication of the hologram, size, misalignment, power budget, components used, actual BER, and more can be found in [20].…”

“…The hypercube modules have been experimentally implemented in the lab [20]. Issues relating to actual fabrication of the hologram, size, misalignment, power budget, components used, actual BER, and more can be found in [20]. We should note that this is one way of implementing the Hypercube module in free space and several other means exist that are currently under study.…”

“…The OMMH can be viewed as a two-level system: a local connection level representing a set of hypercube modules and a global connection level representing the mesh network connecting the hypercube modules. The OMMH network has been physically demonstrated using a combination of free-space and fiber optics technologies, and has shown good performance characteristics [20] for a reasonable size network. However, for very large networks (greater than 1,000 PEs), the OMMH experiences a logarithmic increase in diameter and requires a large amount of fiber, which makes the implementation complicated and expensive.…”

<title>Optical backplanes utilizing multimode polymer waveguides</title>

“…For short distances (<im), the costs for the termination of optical lines are dominant, requiring new approaches to obtain efficient and low-cost optical interconnects. For the realization of an optical backplane, three major approaches can be distinguished: 1) free space optical interconnects (including free space propagation within a backplane)'7, 2) routed fibers8'°, 3) integrated waveguides' [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] Each of these concepts is facing characteristic technical problems. For a waveguide-based solution --which would lead to a compact, rugged and potential low cost realization of an optical backplane -these problems are mainly too high attenuation and insufficient waveguide lengths (19"/5Ocm is required).…”

A spanning bus connected hypercube: a new scalable optical interconnection network for multiprocessors and massively parallel systems

“…The OMMH can be viewed as a two-level system: a local connection level representing a set of hypercube modules and a global connection level representing the mesh network connecting the hypercube modules. The OMMH network has been physically demonstrated using a combination of free-space and fiber optics technologies, and has shown good performance characteristics [17] for a reasonable size network. However, for very large networks (greater than one thousand PE's), the OMMH experiences a logarithmic increase in terms of diameter and requires a large amount of fiber which makes the implementation complicated and expensive.…”