Network-driven adaptive video streaming in wireless environments

In this paper, a concept of a network-driven adaptive video streaming is proposed and investigated in a state-of-the art UMTS/HSDPA network in order to alleviate the impact of strongly time-varying quality of wireless links on video quality. We propose making adaptation decisions in a radio access network based on channel-quality information available there. This is done by a so-called Multimedia Network Controller (MNC), which is aware of server and client capabilities and the channel quality. Upon a decision, the MNC sends a rate switching request to the video server, which adapts its data rate. We evaluate results with a novel PSNR/video-interruptions diagram allowing to show and to compare video quality graphically in a compact form. For the performance evaluation, we developed a comprehensive video streaming testbed around a detailed UMTS/HSDPA emulation tool.