1. School of Computer and Information Engineering, Chuzhou University, Chuzhou, China
2. Department of Communications and Networking, School of Electrical Engineering, Aalto University, Espoo, Finland
3. School of Computer Science and Technology, Xidian University, Xi’an, China
4. School of Systems Information Science, Future University Hakodate, Hakodate, Japan
5. College of Information Science and Engineering, Henan University of Technology, Zhengzhou, China