1. School of the Instrument Science and Technology, and the School of Electrical Engineering, Xi'an Jiaotong University, Xi'an, China
2. School of Computer Science and Engineering, University of Minnesota, Twin City, MN, USA
3. Xidian Guangzhou Institute of Technology, Guangzhou, China
4. Department of Electronic Engineering, Tsinghua University, Beijing, China
5. School of Software, University of Technology Sydney, Sydney, NSW, Australia
6. School of Computer Science, University of Oklahoma, Norman, OK, USA
7. Distributed Systems Group, TU Wien, Vienna, Austria