Formal Definition and Detection Algorithm for Passive Event in RFID Middleware

In RFID middleware, passive event refers to one kind of composite event, some of whose constituent sub-events do not occur under certain condition. To process complex RFID business logic, we should be able to define a wide variety of passive event types and perform efficient event detection. In this paper, we design an event definition language which well supports specifying complex hierarchical passive event, and propose a detection algorithm with some optimization techniques for recognizing passive event. We finally compare our work with Esper in detection performance.