An Energy-Efficient Framework for Multi-Rate Query in Wireless Sensor Networks

Minimizing the communication overhead is always a hot topic in wireless sensor networks. In a multi-rate query system, data sources disseminate the data streams to users at the frequency they request. However, sending data in different frequency to individual users is very costly. We address this problem by broadcasting a single consolidated data stream, aiming at reducing the amount of transmitted data. Taking into account the data correlation, we can re-construct the data streams at lower frequencies from the consolidated stream at a higher frequency. In this paper, we propose an energy-efficient framework to process multi-rate queries and investigate rate conversion mechanism. We evaluate both the accuracy and energy efficiency by simulation. Simulation results indicate that with a reasonable level of tolerance, the performance gain is significant. As far as we know, this is the first energy-efficient solution for multi-rate query in wireless sensor networks.