A Composite Events Detecting Approach Based on Similar Sub-events

RFID technologies are applied extensively in Cyber-Physical Systems (CPS). RFID system collects, filters, and integrates large volume of events gathered continuously by readers to process composite event detections from applications. When the system processes many composite events, detection sharing is quite important for their execution and enhancing the performance of the system. In this paper, we propose a composite event detecting approach based on similar sub-event for RFID event streams. In order to achieve it, we propose the concept of small event by analyzing the different composite event and the relationship between operators, give the rules and properties of composite event rewriting, and give an approach of small event sharing and an implementation strategy for sharing similar sub-events. Finally, we demonstrate the effectiveness of our approach through a detail performance analysis of our algorithm implementation as well as through a comparison to a typical detection algorithm.