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

A new scalable interconnection topology suitable for massively parallel systems called the spanning bus connected hypercube (SBCH) is proposed. The SBCH uses the hypercube topology as a basic building block and connects such building blocks using multidimensional spanning buses. In doing so, the SBCH combines positive features of both the hypercube (small diameter, high connectivity, symmetry, simple routing, and fault tolerance) and the spanning bus hypercube (SBH) (constant node degree, scalability, and ease of physical implementation), while at the same time circumventing their disadvantages. The SBCH topology permits the efficient support of many communication patterns found in different classes of computation such as bus-based, mesh-based, tree-based problems as well as hypercube-based problems. A very attractive feature of the SBCH network is its ability to support a large number of processors while maintaining a constant degree and constant diameter. Other positive features include symmetry, incremental scalability, and fault-tolerance. An optical implementation methodology is proposed for SBCH. The implementation methodology combines both the advantages of free space optics with those of wavelength division multiplexing techniques. A detailed analysis of the feasibility of the proposed network is also presented