This is an early access version, the complete PDF, HTML, and XML versions will be available soon. Open AccessArticle by Xize Wang 1,*, Haiyu Ding 1, Zhenghu Luo 1, Xiaodong Xu 2, Yinghui Wei 1, Yuanhang Li 1, Qing Wang 1 and Qianfan Jia 1 1 China Mobile Research Institute, Beijing 100053, China 2 State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing 100876, China * Author to whom correspondence should be addressed.