A cross - layer optimization of video transmission based on packet loss rate in 802.11e wireless networks

Although the smaller quantization parameter has smaller coding distortion of message source, the overall distortion rate at the receiver does not necessarily decrease as its quantization parameter decreases. The reason is that a smaller quantization parameter often means a long transmission queue, and a long transmission queue means a bigger loss rate and channel distortion. In this paper, we propose a packet loss-distortion driven cross-layer optimization of video transmission for H.264 video applications in 802.11e wireless networks. Firstly, we analyzed the relationship between quantization parameter and quantization distortion and built an estimation model of transmission distortion. Then the total distortions in the received station are estimated according to the packet loss rate of different video data partition. Secondly, a selection algorithm of optimal quantization parameter based on the total distortion is presented. Our experimental results demonstrate that, at certain loss rates, the proposed method not only outperforms the up-bottom cross-layer optimization with various queue priorities for video data partitions, but also outperforms the bottom-up cross-layer with an adaptive quantization step selection both in terms of received-end destination and video traffic.