Reducing communication latency with path multiplexing in optically interconnected multiprocessor systems

Reducing communication latency, which is a performance bottleneck in optically interconnected multiprocessor systems, is of prominent importance. A conventional approach for establishing connections in multiplexed networks uses a set of independent time slots (or virtual channels) along a path for each connection. This approach requires the use of switching devices capable of interchanging time slots, and thus introduces latency in addition to hardware and control complexity. We propose an approach to all-optical time division multiplexed (TDM) communications in multiprocessor systems. The idea is to establish a connection along a path using a set of time slots (or virtual channels) that are dependent on each other, so that no time slot interchanging is required. We compare the proposed approach with the conventional one in terms of the overall communication latency. We found that, despite the possibility that establishing a connection may take a longer time, the proposed approach will result in lower overall communication latency as it eliminates the delays introduced by the time slot interchanging switching devices.