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Low-Latency Video Streaming with Congestion Control in Mobile Ad-Hoc Networks，30 pages,15837 words
Abstract
In this paper, we address the challenge of delivering a video stream, encoded with multiple descrip-
tions, in a mobile ad-hoc environment with low-latency constraints. This kind of application is meant
to provide an ef?cient and reliable video communication tool in scenarios where the deployment of an
infrastructure is not feasible, such as military and disaster relief applications. First, we present a recently
proposed protocol that employs a reliable form of one-hop broadcast to build an ef?cient overlay network
according to a multi-objective function that minimises the number of packets injected in the network
and to maximises the path diversity among descriptions. Then, we introduce the main contribution of
this article: a cross-layer congestion control strategy where the MAC layer is video-coding aware and
adjusts its transmission parameters (namely, the RTS retry limit) via congestion/distortion optimisation.
The main challenge in this approach is providing a reliable estimation of congestion and distortion, given
the limited information available at each node. Our simulations show that, if a stringent constraint of
low delay is imposed, our technique grants a consistent gain in terms both of both PSNR and delay
reduction, for bitrates up to a few megabits per second.