Network-adaptive selection of transport error control (NASTE) for video streaming over WLAN

Abstract

Video streaming over wireless networks is inherently vulnerable to burst packet losses caused by dynamic wireless channel variations with time-varying fading and interference. To alleviate this limitation, especially in the transport layer, the error control schemes based on FEC (forward error correction), ARQ (automatic repeat request), interleaving, and their hybrid are essential. However, each error control mode shows different performance according to the target application requirement and the channel status. Thus, in this paper, we propose a network-adaptive selection of transport error control (NASTE), where transport-layer error control modes are dynamically selected and applied. First, an effective embedded (software-based) realization of error control modes is proposed to support the flexible mode switching for NASTE. We then present a practical yet effective mode switching algorithm by linking channel/application monitoring, table-guided mode switching decision, and subsequent fine-tuning on error-control mode parameters. Finally, we have implemented a prototype video streaming system with NASTE support and verified it over an IEEE 802. 11g WLAN (wireless LAN) environment. The experimental results indicate that the proposed mechanism can enhance the overall transport performance by recovering packet losses and thus improves the quality of video streaming over WLAN(1).