A class of highly scalable optical crossbar-connected interconnection networks (SOCNs) for parallel computing systems

A class of highly scalable interconnect topologies called the Scalable Opti cal Crossbar-Connected Interconnection Networks (SOCNs) is proposed. This p roposed class of networks combines the use of tunable Vertical Cavity Surfa ce Emitting Lasers (VCSEL's), Wavelength Division Multiplexing (WDM) and a scalable, hierarchical network architecture to implement large-scale optica l crossbar based networks. A free-space and optical waveguide-based crossba r interconnect utilizing tunable VCSEL arrays is proposed for interconnecti ng processor elements within a local cluster. A similar WDM optical crossba r using optical fibers is proposed for implementing intercluster crossbar l inks. The combination of the two technologies produces large-scale optical fan-out switches that could be used to implement relatively low cost, large scale, high bandwidth, low latency, fully connected crossbar clusters supp orting up to hundreds of processors. An extension of the crossbar network a rchitecture is also proposed that implements a hybrid network architecture that is much more scalable. This could be used to connect thousands of proc essors in a multiprocessor configuration while maintaining a low latency an d high bandwidth. Such an architecture could be very suitable for construct ing relatively inexpensive, highly scalable, high bandwidth, and fault-tole rant interconnects for large-scale, massively parallel computer systems. Th is paper presents a thorough analysis of two example topologies, including a comparison of the two topologies to other popular networks. In addition, an overview of a proposed optical implementation and power budget is presen ted, along with analysis of proposed media access control protocols and cor responding optical implementation.