Modeling and analysis of fault tolerant multistage interconnection networks

Performance and reliability are two of the most crucial issues in today´s high-performance instrumentation and measurement systems. High speed and compact density multistage interconnection networks (MINs) are widely-used subsystems in different applications. New performance models are proposed to evaluate a novel fault tolerant MIN arrangement, thereby assuring performance and reliability with high confidence level. A concurrent fault detection and recovery scheme for MINs is considered by rerouting over redundant interconnection links under stringent real-time constraints for digital instrumentation such as sensor networks. A switch architecture for concurrent testing and diagnosis is proposed. New performance models are developed and used to evaluate the compound effect of fault tolerant operation (inclusive of testing, diagnosis, and recovery) on the overall throughput and delay. Results are shown for single transient and permanent stuck-at faults on links and storage units in the switching elements. It is shown that performance degradation due to fault tolerance is graceful while performance degradation without fault recovery is unacceptable.