Scalable video streaming with utilization of multiple radio interfaces: A customized method for signaling and bandwidth estimation

Scalable video coding allows to stream the multimedia content in hierarchically structured flows selected by the client due to his quality needs. In this paper we aim to improve the mobile user's media experience by a utilization of multiple wireless interfaces of the user's terminal over which the flows are streamed. Thereby we mitigate the factors of varying cell load, fading effects, and interference, which result in fluctuations in the link quality. We first introduce appropriate server and client entities and provide a signaling method for switching codec layers to the most suitable wireless interface. We verify the performance of the operation of the signaling mechanism using WLAN and UMTS as examples. In addition we develop a tool for dynamic bandwidth estimation that mixes probe packets in between the video stream to induce less traffic. We verify for the case of WLAN that the bandwidth estimator gives more accurate results than using probe packets only. Using both the signaling mechanisms and WLAN bandwidth estimation we use an example selection rule and measure the achieved PSNR gains in the received video.