Real-time scheduling in a generic fault-tolerant architecture

Previous ultra-dependable real-time computing architectures have been specialised to meet the requirements of a particular application domain. Over the last two years, a consortium of European companies and academic institutions has been investigating the design and development of a Generic Upgradable Architecture for Real-time Dependable Systems (GUARDS). The architecture aims to be tolerant of permanent and temporary, internal and external, physical faults and should provide confinement or tolerance of software design faults. GUARDS critical applications are intended to be replicated across the channels which provide the primary hardware fault containment regions. In this paper, we present our approach to real-time scheduling of the GUARDS architecture. We use an extended response-time analysis to predict the timing properties of replicated real-time transactions. Consideration is also given to the scheduling of the inter-channel communications network.