1. Department of Communications and Computer Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan
2. School of Electronics, Electrical Engineering and Computer Science, Queen's University, Belfast, U.K.
3. Department of Software and Communications Engineering, Hongik University, Seoul, South Korea
4. Network and Communication Technology Lab, Centre for Cyber Security,Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
5. Center for Wireless Communications, University of Oulu, Oulu, Finland