Author :
Wu, Dapeng ; Hou, Yiwei Thomas ; Zhang, Ya-Qin
Author_Institution :
Dept. of Electr. & Comput. Eng., Carnegie Mellon Univ., Pittsburgh, PA, USA
Abstract :
With the emergence of broadband wireless networks and increasing demand of multimedia information on the Internet, wireless multimedia services are foreseen to become widely deployed in the next decade. Real-time video transmission typically has requirements on quality of service (QoS). However, wireless channels are unreliable and the channel bandwidth varies with time, which may cause severe degradation in video quality. In addition, for video multicast, the heterogeneity of receivers makes it difficult to achieve efficiency and flexibility. To address these issues, three techniques, namely, scalable video coding, network-aware adaptation of end systems, and adaptive QoS support from networks, have been developed. This paper unifies the three techniques and presents an adaptive framework, which specifically addresses video transport over wireless networks. The adaptive framework consists of three basic components: (1) scalable video representations; (2) network-aware end systems; and (3) adaptive services. Under this framework, as wireless channel conditions change, mobile terminals and network elements can scale the video streams and transport the scaled video streams to receivers with a smooth change of perceptual quality. The key advantages of the adaptive framework are: (1) perceptual quality is changed gracefully during periods of QoS fluctuations and hand-offs; and (2) the resources are shared in a fair manner
Keywords :
broadband networks; mobile communication; multicast communication; multimedia communication; quality of service; video coding; Internet; QoS fluctuations; adaptive services; broadband wireless networks; channel bandwidth; hand-offs; mobile terminals; multimedia information; network elements; network-aware end systems; perceptual quality; quality of service; real-time video transmission; scalable video coding; video multicast; video transport; wireless multimedia services; Adaptive systems; Bandwidth; Degradation; IP networks; Quality of service; Streaming media; Video coding; Video sharing; Web and internet services; Wireless networks;