Enforcing Composability for Ubiquitous Computing Systems * (Extended Abstract) Raimund Kirner Institut f¨ ur Technische Informatik Technische Universit¨at Wien Treitlstraße 3/182/1 A-1040 Wien, Austria raimund@vmars.tuwien.ac.at Abstract Ubiquitous computing provides a paradigm shift in computing systems to an environment with a potentially large number of typically small networked components. At the same time they tend to disappear from the view of the user by providing user interfaces through the physical world. But this new paradigm also requires adapted design and engineering methods to guarantee a certain quality of service and scalability of the system. This becomes most important when ubiquitous computing is used in the field of dependable computing. New concepts have to be provided to cope with the complexity of the large number of components. In this work we address the issue of designing dependable computing systems in such an environment by providing composability verification services. Keywords: Dependable Systems, Ubiquitous Computing, Dynamic Configuration, Compos- ability 1 Introduction Ubiquitous computing provides a new paradigm in system design. Classical computer systems typically serve one or more users where in ubiquitous computing a potentially large number of small networked components will provide the services. From the point of user interface, ubiqui- tous computing can be seen as the opposite of virtual reality, because ubiquitous computing will integrate information displays into the everyday physical world [6]. In ubiquitous computing the hardware will disappear from the view of the user, e.g. wearable computing [5]. This new type of computing with a large number of components requires new concepts in hardware and software engineering. For example, the critical factor in mobile communication * This work has been supported by the IST research project “High-Confidence Architecture for Distributed Control Applications (NEXT TTA)” under contract IST-2001-32111.