Abstract: Video communication within a Vehicular Ad Hoc Network (VANET) has
the potential to be of considerable benefit in an urban emergency, as it allows
emergency vehicles approaching the scene to better understand the nature of the
emergency. However, the lack of centralized routing and network resource
management within a VANET is an impediment to video streaming. To overcome
these problems the paper pioneers source-coding techniques for VANET video
streaming. The paper firstly investigates two practical multiple-path schemes,
Video Redundancy Coding (VRC) and the H.264/AVC codec's redundant frames. The
VRC scheme is reinforced by gradual decoder refresh to improve the delivered
video quality. Evaluation shows that multiple-path 'redundant frames' achieves
acceptable video quality at some destinations, whereas VRC is insufficient. The
paper also demonstrates a third source coding scheme, single-path streaming
with Flexible Macroblock Ordering, which is also capable of delivery of
reasonable quality video. Therefore, video communication between vehicles is
indeed shown to be feasible in an urban emergency if the suitable source coding
techniques are selected.
Keywords: Error resilience, IEEE 802.11p, multiple path delivery, redundant frames, VANET, video communication
