Quality of service controlled adaptive video-coding over IEEE 802.11 wireless links

In this paper we present the initial results of experiments where encoded video data is transmitted over an IEEE 802.11a wireless link. The changing link state and the perhaps changing constraints imposed by mobile device or user, moves the optimal settings of both the video encoder and the IEEE 802.11 network layer. The video encoder and the network layer negotiates their options facilitated by a quality of service negotiation scheme called "adaptive resource contracts", thereby jointly optimizing their parameters. When time is a constraint, this optimization has to be fast and simple, maybe even at the cost of finding suboptimal solutions, as long as the found settings gives a better quality of service than fixed parameter settings.