A Robust Routing Method for Top-k Queries in Mobile Ad Hoc Networks

In mobile ad hoc networks (MANETs), to acquire only necessary data items, it is effective for each mobile node to retrieve data items using a top-k query. In our previous work, we proposed a routing method for top-k query processing to reduce traffic while keeping highly accurate query result by using a routing table. This method performs query transmission by unicast to each node which contributes to collect the data items with k-highest scores. However, in highly dynamic networks, the accuracy of query result decreases because its query transmission approach makes only single route to each data item. To solve this problem, we extend the previous method in order to achieve robust routing. In our proposed method of this paper, each node does not unicast a query message, but multicasts the query message to the nodes in its routing table. This method makes multipath transmission of query messages, so that prevents from decreasing of the accuracy of the query result in highly dynamic networks. The simulation results show that our proposed method outperforms our previous method as to accuracy of the query result.