A high-speed interconnection paradigm and its applications to optical interconnection networks

Reconfigurable interconnection networks are versatile for providing a variety of communication patterns to applications programs in multiprocessor systems. The control of such networks, however, presents a major bottleneck in high performance systems. To eliminate this bottleneck, a high-speed interconnection paradigm called Reconfiguration with Time Division Multiplexing (RTDM) is proposed. This dissertation studies RTDM and its applications to optically interconnected networks. With RTDM, a network goes through a sequence of configurations, which is determined either statically or dynamically, in a time division multiplexed way. If the communication patterns of an application are known a priori, static RTDM is applied. A set of possibly conflicting connections required by the application is partitioned into several subsets and a sequence of configurations is determined such that the connections in each subset are established in each configuration. Run time reconfiguration overhead can therefore be eliminated. In this dissertation, optimal embeddings of several common structures are studied as well as some heuristic algorithms for performing static RTDM. The performances of these heuristics are shown to be close to optimal through probability analysis and simulations. In dynamic RTDM, since each configuration in a sequence can be modified independent of others in the sequence, requests can be processed concurrently. As a result, reconfiguration overhead is amortized over the sequence of configurations. Various dynamic RTDM strategies, their implementations and their performances are studied in this dissertation. The proposed RTDM paradigm is especially suitable for optically interconnected networks. This is because the high bandwidth of optical channels can be utilized efficiently through time-sharing of the network resources among a sequence of configurations. Moreover, the implementation of this paradigm is feasible with the current photonic switching technology due to the elimination of the need for optical storage and conversion between electronical and optical signals within the network. The RTDM paradigm can also be applied to avoid crosstalk in electro-optical switches and to assign wavelengths in Wavelength Division Multiplexed systems.