Processing Ad-Hoc Queries in Wireless Sensor Networks

A wireless sensor network (WSN) consists of a large number of sensor nodes that can measure and process data while communicating through wireless channels. In this paper, we propose a hybrid query processing (HQP) algorithm for user queries submitted to the WSN. Unlike previous algorithms that consider continuous queries only, HQP supports both continuous queries and ad-hoc queries. Specially, HQP tries to reduce energy consumption of ad-hoc queries by using query results cached at each sensor node which are created during the execution of the previous continuous queries. HQP can also exploit a trade-off between energy consumption and data accuracy. We compare the performance of HQP with previous algorithms using our simulation model.