Providing Adaptive QoS to Layered Video Over Wireless Local Area Networks Through Real-Time Retry Limit Adaptation

Q. Li, M. vanderSchaar
2004 IEEE transactions on multimedia  
Robust streaming of video over 802.11 wireless LANs (WLANs) poses many challenges, including coping with packets losses caused by network buffer overflow or link erasures. In this paper, we propose a novel error protection method that can provide adaptive quality-of-service (QoS) to layered coded video by utilizing priority queueing at the network layer and retry-limit adaptation at the link layer. The design of our method is motivated by the observation that the retry limit settings of the MAC
more » ... layer can be optimized in such a way that the overall packet losses that are caused by either link erasure or buffer overflow are minimized. We developed a real-time retry limit adaptation algorithm to trace the optimal retry limit for both the single-queue (or singlelayer) and multiqueue (or multilayer) cases. The video layers are unequally protected over the wireless link by the MAC with different retry limits. In our proposed transmission framework, these retry limits are dynamically adapted depending on the wireless channel conditions and traffic characteristics. Furthermore, the proposed priority queueing discipline is enhanced with packet filtering and purging functionalities that can significantly save bandwidth by discarding obsoleted or un-decodable packets from the buffer. Simulations show that the proposed cross-layer protection mechanism can significantly improve the received video quality. Index Terms-Adaptive control, cross layer design, home communication system, multimedia communication, queueing analysis, wireless LAN. development of Internet video streaming technology. His current research interests include computer networks, wireless communications and multimedia communications with emphasis on active queue management, cross-layer optimization, protocol design, and streaming server architecture. Mihaela van der Schaar (M'98-SM'04) received the M.Sc. and Ph.D. degrees in electrical engineering
doi:10.1109/tmm.2003.822792 fatcat:grscvwwmi5edvgwd36zubqeffy