Distortion-based video streaming over Vehicular Ad Hoc Networks in highway

There are already many routing protocols tailored for Vehicular Ad Hoc Networks (VANET). However, few of them are suitable for real-time video streaming delivery. The network partition nature and dynamic changing network topology of VANET make it hard for existing protocols to satisfy the stringent delay requirements of video streaming or other multimedia applications. To address this issue, this study first develops a rate distortion model based on a shadowing model and 802.11 DCF with RTS/CTS scheme over a highway road segment. Based on the proposed rate distortion model and traffic statistic information (vehicle density over a road), we can decide the best next-hop forwarding distance. Since a vehicle may not have a neighbor vehicle at the best forwarding distance, this study proposes a cell based packet forwarding scheme based on the derived best forwarding distance to prioritize the neighboring vehicles of a sender We set up the simulations using NS2 to validate the performance of the proposed protocol. The results show that the proposed protocol can yield a 30% PSNR improvement.