CONCURRENCY AND COMPUTATION: PRACTICE AND EXPERIENCE Concurrency Computat.: Pract. Exper. 2010; 22:518–537 Published online 18 September 2009 in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/cpe.1503 Two-level cooperative and energy-efficient tracking algorithm in wireless sensor networks Guojun Wang ∗, † , Md. Zakirul Alam Bhuiyan and Li Zhang School of Information Science and Engineering, Central South University, Changsha, Hunan Province 410083, People’s Republic of China SUMMARY Conventional target tracking systems are based on powerful sensor nodes, capable of detecting and locating a target in a large deployment area but most systems require high transmission power levels and a large volume of messages, much time for neighbor discovery operations, and many sensors to detect the target at a given time. We propose a two-level cooperative and energy-efficient tracking algorithm (CET) that reduces energy consumption by requiring only a minimum number of sensor nodes to participate in communication, transaction, and perform sensing for target tracking in wireless sensor networks. It is expected that only the nodes adjacent to the target are responsible for observing the target to save the energy consumption and extend the network lifetime as well by using a wakeup mechanism and a face-aware routing. Through performance analysis and simulation studies, we demonstrate that CET improves target capturing speed and outperforms some existing protocols of target tracking with energy saving under certain ideal situations. Copyright © 2009 John Wiley & Sons, Ltd. Received 3 January 2009; Revised 4 June 2009; Accepted 17 July 2009 KEY WORDS: wireless sensor networks; target tracking; wakeup mechanism; face-aware routing; energy efficiency ∗ Correspondence to: Guojun Wang, School of Information Science and Engineering, Central South University, Changsha, Hunan Province 410083, People’s Republic of China. † E-mail: csgjwang@gmail.com, csgjwang@mail.csu.edu.cn Contract/grant sponsor: Hunan Provincial Natural Science Foundation of China for Distinguished Young Scholars; contract/grant number: 07JJ1010 Contract/grant sponsor: National Natural Science Foundation of China for Major Research Plan; contract/grant number: 90718034 Contract/grant sponsor: Program for New Century Excellent Talents in University; contract/grant number: NCET-06-0686 Contract/grant sponsor: Program for Changjiang Scholars and Innovative Research Team in University; contract/grant number: IRT0661 Copyright 2009 John Wiley & Sons, Ltd.