DECOS: An Integrated Time-Triggered Architecture

Abstract

Depending on the physical structuring of large distributed safety-critical real-time systems, one can distinguish federated and integrated system architectures. This paper describes an integrated system architecture, which combines the complexity management advantages of federated systems with the functional integration and hardware benefits of an integrated approach. This architecture builds upon the validated core architectural services of a time-triggered core architecture. A distributed time-triggered computer system provides a physical network as a shared resource for the communication activities of more than one application subsystem. In analogy, we share node computers among the software modules of multiple application subsystems. In order to control complexity, we argue that the integrated architecture needs to support a similar functional structuring of the overall system as in a federated architecture. By dividing the overall functionality into a set of application subsystems, each with dedicated architectural communication services, developers can act as if they were building an application for a federated architecture. Architectural encapsulation mechanisms ensure that the assumptions and abstraction performed in the functional system structuring also hold after combining the different subsystems on the target platform.