Congestion-adaptive and queue reservation scheme for delay-constrained video streaming over IEEE 802.11 networks

This paper investigates the issue of delay-constrained video delivery over IEEE 802.11 networks. We analyze the characteristics of MAC from the viewpoint of queuing theory and the packet loss probability for video by jointly considering the forward error correction (FEC) and decoding deadline. By taking the efficient Shortened-and-Punctured Reed-Solomon codes as the basis of application-FEC, we propose a congestion-adaptive packets scheduling (CPS) scheme to add unequal error protection (UEP) function into the 802.11-based system for video transmission. The CPS scheduler optimizes the expectation of transmission distortion according to the importance of video packets and the states of MAC queue. After getting the optimal solution, it punctures the source and parity packets in the FEC group and sends out the remnant ones. To restrain the negative effect of burst behavior of parity packets, a dynamic reservation mechanism for queue space is further introduced. Simulation results demonstrate that our scheme has significant PSNR gain in comparison with other methods.