ABSTRACT
The fi rst of these changes involved the defi nition of an embedded system . At the beginning of the project, this term was commonly interpreted as meaning a single application running on a terminal with a small number of sensors and actuators; however, the embedded system we needed to address in reality was an application on a terminal operating in conjunction with a back-end server. As a result, we needed to extend the defi nition accordingly. Systems with this type of confi guration are numerous and include mobile phones, rail and air ticket gates, electronic points-of-sale in supermarkets, and ATMs. Extending the scope of the project in this way meant that server systems and distributed systems would also need to be considered, so we decided that the term “embedded systems” should be replaced with “real-world systems”. The Dependable Embedded OS developed as the fi rst deliverable of the DEOS Project supported this extension by providing enhanced functionality for hierarchical isolation of processes and for monitoring and logging.
