Multi-layer video broadcasting with low channel switching delays

Modern mobile devices, despite their small sizes, can run many multimedia applications that were only possible to stationary workstations. Mobile devices, however, have quite heterogeneous resources, which poses a challenge to mobile TV broadcast networks. We study the problem of broadcasting multi-layer video streams to mobile devices with heterogeneous resources. We propose broadcast schemes that allow each mobile device to selectively receive a few (or all) layers of the complete video streams, and achieve proportional energy saving. We also propose a broadcast scheme that achieves low channel switching delay, which is important to user experience. We analytically analyze the performance of the proposed schemes. Most importantly, we have implemented them in a real mobile TV testbed. We conduct extensive experiments to show the practicality and efficiency of the proposed schemes. The experimental results show that channel switching delays less than 200 msec and energy saving between 75% and 95% are possible under typical system parameters of mobile TV networks.