Congestion and error control for layered scalable video multicast over WiMAX

Quality of service (QoS) of wireless multimedia can be seriously degraded due to the more dynamically changing end-to-end available bandwidth caused by the wireless fading/shadowing and link adaptation. Moreover, the increased occurrence of wireless radio transmission errors also results in higher bursty rate of packet loss when compared with wired IP networks. An end-system driven solution featuring embedded probing for layered multicast of scalable video is thus proposed in this paper. By taking advantage of QoS features offered by one of the four proposed WiMAX service flow arrangement, this system aims at more flexible layer constructing and subscription while reliable in diverse channel conditions and fitting users´ demand. The system optimality comes from the best tradeoff of number of video layers subscription with number of additional FEC packets insertion to simultaneously satisfy the estimated available bandwidth and the estimated wireless channel error condition