Louri A, Sung H
Appl Opt. 1994 Nov 10;33(32):7588-98. doi: 10.1364/AO.33.007588.
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 the size of the network can be increased with nominal effect on the existing configuration. Also, the increase in size is expected to result in a linear increase in performance. Time scalability implies that the communication capabilities of a network should be large enough to support the evolution of processing elements through generations. A modular network enables the construction of a large network out of many smaller ones. The lack of these two important parameters has limited the use of certain types of interconnection networks in the area of massively parallel computers. We present a new modular optical interconnection network, called an optical multimesh hypercube (OMMH), which is both size and time scalable. The OMMH combines positive features of both the hypercube (small diameter, high connectivity, symmetry, simple routing, 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 optics to provide compact and high-density localized hypercube connections. The OMMH network is then constructed by the connection of such basic building blocks with multiwavelength optical fibers to realize torus connections. The proposed implementation methodology is intended to exploit the advantages of both space-invariant free-space and multiwavelength fiber-based optical interconnect technologies. The analysis of the proposed implementation shows that such a network is optically feasible in terms of the physical size and the optical power budget.
大规模并行计算机网络的两个重要参数是可扩展性和模块化。可扩展性有两个方面：规模和时间（或代际）。规模可扩展性指的是网络规模能够增加，而对现有配置的影响最小。此外，规模的增加预计会带来性能的线性提升。时间可扩展性意味着网络的通信能力应足够大，以支持处理元件随代际的演进。模块化网络能够由许多较小的网络构建出大型网络。缺乏这两个重要参数限制了某些类型的互连网络在大规模并行计算机领域的应用。我们提出了一种新的模块化光互连网络，称为光多网格超立方体（OMMH），它在规模和时间上都是可扩展的。OMMH结合了超立方体（直径小、连接性高、对称性好、路由简单且容错）和环面（节点度恒定且规模可扩展）网络的优点。还介绍了OMMH网络的三维光实现。OMMH网络的一个基本构建块是一个超立方体模块，它由自由空间光学器件构建而成，以提供紧凑且高密度的局部超立方体连接。然后通过将这些基本构建块与多波长光纤连接来构建OMMH网络，以实现环面连接。所提出的实现方法旨在利用空间不变自由空间和基于多波长光纤的光互连技术的优势。对所提出实现方案的分析表明，这样的网络在物理尺寸和光功率预算方面在光学上是可行的。
