Exploiting local node cache in top-k queries within wireless sensor networks
Johannes Niedermayer, Mário A. Nascimento, Matthias Renz, Peer Kröger, Hans‐Peter Kriegel · 2010
Top-k queries are a popular type of query in wireless sensor networks. Typical solutions rely on coordinated root-to-nodes and nodes-to-root messages and on maintaining filters at the nodes, aiming at suppressing unnecessary messages, hence saving energy and furthering the network's lifetime. In this paper, we exploit the capability of a sensor node to cache a few recently observed values in order to determine "trends" for the observed values. Those trends can be used to further restrict the number of messages that need to be exchanged in the network, thus ultimately extending the network's lifetime. We compare our approach to the most recently proposed solutions in the literature using real and synthetic datasets, and we show that our approach is able to improve the network's lifetime by up to 28% without any loss in the quality of the answer.