An Efficient and Robust Routing Protocol for Data Aggregation

Abstract

Wireless Sensor Network (WSN), which is free from infrastructure, greatly enhances our capability of observing physical world. However, WSN’s independent and un-attended usages, which are generally supposed to be advantages, also limit its power supply and life expectancy. As a result, energy efficiency is a critical issue for any WSN implementation. In-network processing (a process of data local convergence and aggregation) which intends to minify data volume locally can greatly reduce the energy consumption of data delivery over long distance to the sink. However, open problems are still remain, such as, how to carry out in-network processing, and how to combine routing scheme to the sink (corresponding to the long distance delivery) with in-network processing. For any WSN application, a pre-assumption is vital that there must be a physical signal field (e.g. a field of sensing signal) that bridge physical event to sensors, otherwise WSN can not work. Moreover, the physical signal field can be used for data local convergence. Our proposed algorithm exploits the gradient direction of the physical signal field. Along the gradient direction of the physical signal field, sensory data at sensors will also converge to local extremes of the physical signal field. In addition, this routing scheme for in-network process requires zero overhead, because the physical signal field exists naturally. The proposed schemes are simple to be implemented, and details of the implementation are discussed. Simulation shows that the schemes are robust, adaptable, and reliable to variation of physical events.