Reconfigurable middleware for sensor based applications

The pervasive computing paradigm introduced context-aware applications that adapt themselves to their surrounding environment based on context information. Context information may be of different types including sensed context information gathered from a variety of sensors. In pervasive computing user intervention/interactions with their application should be minimised. On the other hand, pervasive computing environments are very dynamic environments -context information that supports adaptation decisions may not always be available due to user mobility and potential network and/or sensor failures. As context information supports autonomous adaptation of applications, the provision of context information itself has to be managed by an autonomic system able to both recognise and recover from context delivery failures. This paper presents the architecture of a context management system that is reconfigurable with regard to sensor and/or network failure and can support dynamic discovery and replacement of sensors. One of the components of this middleware architecture, the model and management of sensor descriptions, is described in more detail as it plays an important role in sensor discovery and replacement.