Error Resilient Real-Time Multimedia Streaming over Vehicular Networks

This paper focuses on the optimized transmission of multimedia sequences over vehicular ad-hoc networks (VANETs). Among the main drawbacks of the high node mobility of the vehicular scenario are the high channel loss rate, burst length and intermittent connectivity. To allow real-time streaming of media sequences in such a scenario, we propose a technique based on forward error correction (FEC) and interleaving algorithms able to recover most of packet losses and reduce the length of the error bursts. The proposed technique is based on the optimization of the FEC/Interleaving parameters under real-time constraints. It is implemented at packet level, to allow a straightforward adoption in the existing wireless devices. By resorting to standard compliant, real-time RTCP reports, we also develop an adaptive technique able to adapt to fast channel variations and to optimize both the overhead required by the proactive error recovery scheme and the additional delay introduced by the interleaver. Simulations based on real world experiments show that the proposed technique is able to gain over 2 dB in terms of video PSNR with respect to the standard transmission, while in the adaptive case the gain is over 2.5 dB PSNR, with a total overhead of about 50%.