Scalable video coding and transport over broad-band wireless networks

With the emergence of broadband wireless networks and increasing demand of multimedia information on the Internet, wireless multimedia services are fo reseen to become widely deployed in the next decade. Real-time video transm ission typically has requirements requirements on quality service (QoS). Ho wever, wireless channels are unreliable and the channel bandwidth varies wi th time, which may cause severe degradation to video quality In addition,fo r video multicast, the heterogeneity of receivers makes it difficult to ach ieve 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 unifie s the three techniques and presents an adaptive framework, which specifical ly 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 elemen ts can scale the video streams and transport the serried video streams to r eceivers with a smooth change of perceptual quality. The key advantages of the adaptive framework are: 1) perceptual quality is changed gracefully dur ing periods of QoS fluctuations and handoffs; and 2) the resources are shar ed in a fair manner.