Cross-Layer Joint Optimization of FEC Channel Codes and Multiple Description Coding for Video Delivery over IEEE 802.11e Links

The paper presents two cross-layer optimization strategies based on the IEEE 802.11e standard that enable a robust video transmission using adaptively forward error correction (FEC) channel codes at transport layer and a multiple description coding (MDC) architecture. The first approach estimates an array of correlation measures for the group of picture to be transmitted and classifies it using a vector quantizer. The most appropriate coding mode is selected according to the correlation class and the channel conditions obtained through a cross-layer signalling protocol. The second solution relies on a parametric model of the channel distortion based on the percentage of null quantized transform coefficients, which can be obtained during the coding operations. According to the state of the network, the optimization algorithm estimates the expected quality of the reconstructed sequence for each mode and chooses the best one. Experimental results show that both algorithms perform well with a small computational effort but different playout delays.