Hierarchical star-controlled rings: scalable reliable networks for multiprocessors

This paper presents two fast hierarchical scalable and reliable interconnection networks for high-performance multiprocessors. These networks are constructed by arranging star-controlled rings in the hierarchy of an k-ary X-tree. In addition to the nodes of a ring, a star-controlled ring also has a node in the center that is connected to each of the nodes on the circumference. Similar to fat-trees [1], the processors are located at the leaves of the networks and, the communication bandwith of the links increases from the level of leaves towards the root as the number of descendants of a node increases. One of these networks is implemented optically using acousto-optic tunable filters, passive couplers, and the technique of wavelength division multiplexing on single-mode optical fibers.