Architectural issues in designing heterogeneous parallel systems with passive star-coupled optical interconnection

This paper investigates architectural and communication issues in designing heterogeneous parallel systems. The emerging high speed passive star-coupled optical interconnection using wavelength division multiplexing is considered as the system interconnect to provide high bandwidth communication demanded by heterogeneous systems. A representative master-slave computational model together with two different task scheduling strategies are used to evaluate and determine suitable communication strategy for such systems. It is shown that a hierarchical ALOHA-based communication strategy between the master and the slaves, implemented on top of the passive star-coupled network, leads to a considerable reduction in contention and task completion time compared to the direct communication from the slaves to the master. The time division multiplexed access (TDMA) approach has performance comparable to the hierarchical strategy. Depending on the application characteristics, the number of levels in the hierarchal scheme can be chosen to provide a balance between channel contention and overall execution time. These results provide guidelines for designing scalable heterogeneous systems in near future.<>