Event-based systems for detecting real-world states with sensor networks: a critical analysis

Wireless sensor networks can be considered as a tool for detecting certain states in the real world. We examine the use of event-based approaches for this task. In the literature, a number of event notification systems have been presented that facilitate the specification and automatic detection of event patterns - so-called composite events. While events are a valuable abstraction in sensor networks, we show that composite events are less suited to detect real-world states with sensor networks. We illustrate an alternate solution that retains the advantages of an event-based approach, but which provides better support for the specification and detection of real-world states.