Multi-layer faults in the architectures of mobile, context-aware adaptive applications

Modern hand-held devices are equipped with multiple context sensors exploited by increasingly sophisticated software applications, called Context-Aware Adaptive Applications (CAAAs), that adapt automatically to changes in the surrounding environment, such as by responding to the location and speed of the user. The architecture of CAAAs is typically layered and incorporates a context-awareness component to support processing of context values and triggering of adaptive changes. While this layered architecture is very natural for the design and implementation of CAAAs, it exhibits new kinds of failures that arise as a result of faults that are specific to the choice of technology for specific layers. In this paper we investigate the occurrence of such faults and failures that manifest across architectural layers, and we describe samples of such failures in four CAAAs.