LAUSR

Top-k queries, which retrieve k data items with the best score, have been receiving considerable attention because they can support many real life applications. In this paper, we propose an efficient query routing scheme in mobile ad hoc networks (MANETs), namely CTR. CTR enables top-k data retrieval by only necessary nodes by employing a new clustering framework for top-k query processing. In this framework, nodes holding high rank data items become ClusterHeads (CHs), and top-k queries are transmitted between CHs via gateway nodes which belong to multiple clusters. Each CH maintains a set of hop counts between itself and high rank data items, so that it can judge whether or not to transmit a query on the fly. We further propose a query routing method, CTR$$^{2}$$2, which integrates the clustering framework of CTR and a data replication approach. CTR$$^{2}$$2 improves the performance by retrieving the top-k data from nearby nodes. Extensive experiments have demonstrated that the proposed approaches function well in terms of accuracy of the query result, traffic, and delay.