Yongping Xiong, Ph.D., research fields: mobile opportunistic networks, mobile sensor networks and emerging mobile system. E-mail: xyp@is.iscas.ac.cn. Correspondent author: Jianwei Niu, professor, research fields: embedded and mobile computing and mobile video streaming. E-mail: niujianwei@buaa.edu.cn. Jian Ma, professor, research fields: converged services of wireless network, digital broadcasting, ad-hoc networking and P2P networking. Limin Sun,-professor, research fields: wireless sensor networks and delay tolerant networks.