SHANG Zhi-Jun Research assistant at Shenyang Institute of Automation, Chinese Academy of Sciences (CAS). He is also a Ph.D. candidate in Shenyang Institute of Automation, CAS and Graduate School of the Chinese Academy of Sciences. His research interests include embedded system, network modeling, and protocol design.(E-mail: shangzj@sia.cn) WANG Jun Ph. D. candidate at Shenyang Institute of Automation, CAS and Graduate School of the Chinese Academy of Sciences. His research interests include routing and information processing in wireless sensor network. YU Hai-Bin Professor at Shenyang Institute of Automation, CAS. He received Ph.D. degree in control theory and engineering from Northeast University in 1997. His research interests include real time scheduling theory in industrial communication, wireless sensor network, and distribute artificial intelligence.