1. School of Communication and Information Engineering Department, Chongqing University of Posts and Telecommunications, Chongqing, China
2. School of Computer Science and Technology, Chongqing University of Posts and Telecommunications, Chongqing, China
3. Department of Information and Communication Engineering, School of Informatics, Xiamen University, Xiamen, China
4. Pillar of Information Systems Technology and Design, Singapore University of Technology and Design, Singapore