An Approximation Algorithm for Optimizing Multiple Path Tracking Queries over Sensor Data Streams

Sensor networks have received considerable attention in recent years and played an important role in data collection applications. Sensor nodes have limited Supply of energy. Therefore, one of the major design considerations for sensor applications is to reduce the power consumption. In this paper, we study an application that combines RFID and sensor network technologies to provide an environment for moving object path tracking, which needs efficient join processing. This paper considers multi-query optimization to reduce query evaluation cost, and therefore power consumption. We formulate the multi-query optimization problem and present a novel approximation algorithm which provides solutions with suboptimal guarantees. In addition, extensive experiments are made to demonstrate the performance of the proposed optimization strategy.