A Routing Method for Top-k Query Processing in Mobile Ad Hoc Networks

In mobile ad hoc networks (MANETs), to acquire only necessary data items, it is effective that each mobile node retrieves data items using a top-k query, in which data items are ordered by the score of a particular attribute and the query-issuing mobile node acquires data items with k highest scores. In our previous works, we proposed top-k query processing methods for reducing traffic and also keeping high accuracy of query result. Those methods focus on the traffic reduction by not sending back unnecessary data items. However, queries are forwarded to all of nodes in the entire area by flooding, and thus, many nodes which do not contribute to the query result have to send redundant top-k queries and replies, which increases unnecessary traffic. In this paper, we propose a routing method for top-k query processing in MANETs. In this method, when each mobile node sends a top-k query, it refers to its own routing table consisting of the ranking of scores of data items in the network and identifiers of nodes to which queries are forwarded to obtain the necessary data items. Moreover, each node updates its own routing table when the link disconnection occurs and scores of data items are updated.