Efficient time triggered query processing in wireless sensor networks

In this paper we introduce a novel system that comprises techniques advancing the query processing in wireless sensor networks. Our system facilitates time triggered queries that are scheduled in a distributed fashion among sensor nodes. Thus, time synchronisation is of paramount importance. Since accurate time synchronisation requires more energy, our system allows a trade off between precision of time and energy according to the user requirements. To minimize the communication overhead for query processing, our system employs new query execution mechanisms. We have implemented our query processing system on SunTM Small Programmable Object Technology (SPOT) sensor network platform. The system was entirely programmed in Java enabling an object oriented design and implementation. It provides a friendly graphical user interface for query management and visualisation of results.