Enhanced adaptive cross-layer scheme for low latency HEVC streaming over
  Vehicular Ad-hoc Networks (VANETs)
Mohamed Aymen Labiod Mohamed Gharbi François-Xavier Coudoux Patrick Corlay Noureddine Doghmane
Vehicular communication has become a reality guided by various applications.
Among those, high video quality delivery with low latency constraints required
by real-time applications constitutes a very challenging task. By dint of its
never-before-achieved compression level, the new High-Efficiency Video Coding
(HEVC) is very promising for real-time video streaming through Vehicular Ad-hoc
Networks (VANET). However, these networks have variable channel quality and
limited bandwidth. Therefore, ensuring satisfactory video quality on such
networks is a major challenge. In this work, a low complexity cross-layer
mechanism is proposed to improve end-to-end performances of HEVC video
streaming in VANET under low delay constraints. The idea is to assign to each
packet of the transmitted video the most appropriate Access Category (AC) queue
on the Medium Access Control (MAC) layer, considering the temporal prediction
structure of the video encoding process, the importance of the frame and the
state of the network traffic load. Simulation results demonstrate that for
different targeted low-delay video communication scenarios, the proposed
mechanism offers significant improvements regarding video quality at the
reception and end-to-end delay compared to the Enhanced Distributed Channel
Access (EDCA) adopted in the 802.11p. Both Quality of Service (QoS) and Quality
of Experience (QoE) evaluations have been also carried out to validate the
proposed approach.