Scalable Video Coding And Streaming In Wireless Networks

Video application is becoming an important application under the next-generation wireless networks. However, supporting video communication over wireless networks poses many challenges due to fluctuations of wireless channel conditions. Scalable video coding has been shown to be capable of coping effectively with time-varying wireless environment. In this dissertation, we proposed a cross-layer framework to solve scalable video streaming over wireless networks.The scalable extension of H.264/AVC adopts a hierarchical prediction structure based on open-loop MCTF (Motion-Compensated Temporal Filtering). In this dissertation, we proposed new algorithms to improve the performance of MCTF under JSVM0 framework, including update constraints, residual image deblocking filtering. We also designed a new fractal wavelet hybrid video codec based on EZW, called FEZW. FEZW inherits the embedded structure from EZW. Therefore, its bit rate can be truncated to meet the network bandwidth requirements. On the other hand, the fractal prediction method increases its PSNR at low bit rate. This is also verified via simulations.To improve the quality of received video, we proposed a cross-layer adaptive rate control mechanism, CLARC, which makes good use of 1) routing information from the lower network layer, and 2) the frame loss feedback from the application layer. The proposed scheme tries to adapt the video encoder's output bitrate to closely mimic the available network bandwidth. CLARC is also congestion-aware, robust to random error, and can co-exist with other TCP flows in a friendly manner. Extensive simulations were performed, as well as actual experiments (on our own ad hoc video streaming testbed) were conducted to validate the effectiveness of our scheme.Furthermore, we instigated the congestion optimized routing in wireless ad hoc network and presented a CO-DSR (Congestion Optimized DSR) algorithm based on DSR protocol. The CO-DSR scheme considers both link bandwidth and the number of flows on the path when selecting a route. Simulation results show that CO-DSR can effectively improve the network throughput, the quality of the received FEZW video stream.Lastly, based on the classic WRR (Weighted Round Robin) concepts, we proposed an efficient real-time traffic-scheduling algorithm for WLAN. Our algorithm...