Optimizing Channel Switching for Digital Television Through Low Quality Streams

J. De Wachter, D. Tytgat, V. Verstraete, M. Strobbe, F. Van Quickenborne, P. De Neve, F. De Turck, and P. Demeester (Belgium)


IPTV, Channel switching, Access networks


The popularity of digital television is rapidly increasing. One of its impediments however, is the time it takes to switch from one channel to another. This paper proposes a way to smoothen channel transitions: In addition to the high quality stream, a number of channels is transmitted to the video client in low quality. When the user selects a new channel, the low quality version of the channel is displayed and the high quality version is requested. As soon as the high quality stream is available, high quality video is displayed. This way, the effect of channel switching can be reduced to the user observing lower resolution for a brief moment, instead of watching a blank screen or a frozen frame. In a lab environment, average channel switching time was reduced from 1400 milliseconds to 78 milliseconds.

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