By year

Song Liu, Zhisheng Niu, Dawei Huang, Jianping Shu and Yang Li, Admission Policies for Voice Message Service in Mobile Cellular Networks, Proc. of APCC 2003
Zhisheng Niu, Song Liu, Dawei Huang, Jianping Shu, Yang Li, Modeling and performance analysis of Voice Message Service in mobile communication systems, 2002 China Wireless Congress (Invited paper), http://delson.org/cwc02/, 15-17th, October 2002, Hangzhou, China.
Zhisheng Niu, Song Liu, Stephane Vollet, Zhixing Yang, Youshou Wu, An Integrated ATM System Based on High Altitude Platforms (HAPs), ATM Interact Symposium 2001, pp.243-251, 22-24th August 2001, New Delhi, India.