Reconfigurable ring connected modular tree architecture

A new fault-tolerant architecture (for distributed computation/telecommunications systems), the ring connected modular tree (RCMT), is proposed for binary tree architectures. The RCMT is based on the modular tree design but adds idle spare supplied links (ISSLs). Using these links, an idle spare node of a module can be supplied to the right-hand neighbouring module. This results in a more flexible ‘spare sharing’ approach and a module containing only a single spare can tolerate up to two faults if an idle spare is available to it from the left-hand neighbouring module. By comparison with previously proposed fault-tolerant tree architectures, RCMT achieves the same reliability level as a global approach, for example the SOFT tree approach, but still preserves the same constant re-configuration time as the modular approach. A modular diagnosis algorithm is given to diagnose the actions of all system nodes in a constant execution time.