On the impact of the video quality assessment in 802.11e ad-hoc networks using adaptive retransmissions

This paper investigates the influence of the video quality assessment at the medium access control (MAC) layer of an 802.11e distributed network in which the purpose is to adapt the retry limit of each video packet for maximizing the quality perceived by the end user. Moving from an existing Markov model of the 802.11e access scheme, the number of retransmissions associated to each video packet is evaluated to satisfy the distortion requirements inferred using two quality assessment measures: the mean squared error (MSE) and the structural similarity (SSIM) index. The aim of the proposed work is to discuss the suitability of these measures for managing the retransmission policy in the presence of contention-based mechanisms. The numerical results are obtained using a network simulator implementing the 802.11e enhanced distributed channel access (EDCA) in which the video sequences are encoded using the H.264 scalable video coding (SVC) standard.