1. Qingdao University of Science and Technology, Qingdao, China and Minjiang University, Fuzhou, China
2. Qingdao University of Science and Technology, Qingdao, China
3. University of Sydney, Australia
4. Minjiang University, Fuzhou, China
5. Shandong University of Science and Technology, China
6. Instituto de Telecomunicações, Aveiro, Portugal