A data query system on TinyOS platform for wireless sensor networks

Energy efficiency has been known as the most important problem in designing a data query system in wireless sensor networks (WSNs). In this paper, we propose a novel query method in which the clusters are constructed only in the query area as needed and destroyed after the query ends. To achieve this goal, we design and implement a Tree-Based Clustering (TBC) protocol to support upper layer applications. In TBC, clustering is combined with tree routing and all nodes in WSN use the same communication power. In addition, we adopt a simple approach to solve time synchronization problem among sensor nodes. Simulations show that our methods can save significant amount of energy comparing to HEED and MHRA protocols. The proposed query system is implemented on TinyOS and tested on the sensor nodes developed at Shenzhen Institute of Advanced Technology.