Abstract: As one of the novel mobile value added services,real-rime media streaming has seen increased demand on 3G networks in recent years, and has drawn tremendous attention from both academia and industry, since it is creating a new era of integration of wireless communication, the Internet and video. However, communication over wireless networks is characterized by limited bandwidth, high error rates, unstable and dynamic changes of wireless channel condilion, user mobility, channel competition, etc. These characteristics and stringent QoS requirements of multimedia apphcanons identify significant challenges for providing QoS guarantees for media streaming applications in 3G networks.This work began with a comparison of technology characteristics in 3G standards. On this basis,we explored key technologies of media streaming for 3G networks in terms of QoS system, transport protocol, video coding, and modeling on real-time video traffic. Finally, we outlined key open problems in this area.

Key words: 3G, Media streaming, QoS, Transport protocol, Video coding