Adaptive video stream switching for an IEEE 802.16 channel

The aim of this paper is to enhance video streaming over a broadband wireless link through the application of the H.264/AVC codec´s switching frames whenever channel conditions make a changed rate desirable. Compared to prior use of periodic I-frames transitions between streams are smoother and sudden increases in bitrate are reduced. The proposed streaming system also gives more protection to higher-quality video, reduces delay and packet loss, and improves received video quality. Results also show that increased-quality primary-switching frames together with SI frames bring a significant gain in video quality compared to alternative switching schemes with secondary SP-frames. The other schemes in turn show an improvement to using `no switching´, as demonstrated when streaming takes place over a typical WiMAX channel with burst errors. Packet delay over the transmission link is also reduced.