In this paper, we consider a problem of range-based continuous query processing in mobile ad hoc networks (MANETs). Due to the advantage that no infrastructure is needed, MANETs are useful in various situations such as disaster sites. In such applications, information monitoring techniques are required, for example, to obtain the information on victims. In MANETs, the bandwidth and batteries of nodes are limited and nodes move freely, thus conventional techniques for fixed and wired networks are hard to apply to MANETs. Moreover, periodic data retrieval approach is inefficient because it incurs large traffic to obtain data items continuously. We therefore propose a communication-efficient method for continuously monitoring data existing around a query originating node. Our proposed method does not rely on periodic approach, but rather extends query transmission ranges dynamically and continuously to deal with nodes' movement. Query receiving nodes estimate the current position of the query originating node and forward data items toward the position. This approach also enables efficient data forwarding when data updates occur. Simulation experiments demonstrate the efficiency and scalability of our method.
['Yuki Nakayama', 'Daichi Amagata', 'Takahiro Hara', 'Shojiro Nishio']
Range-based Continuous Threshold Query Processing in Mobile Ad Hoc Networks