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A Multi-Path Error Control Mechanism for Interactive Video in Ad Hoc Networks
Ahmed Abd El Al, Tarek Saadawi and Myung Lee

The increase in the bandwidth of wireless channels and the computing power of mobile devices increase the interest in video communications over ad hoc wireless networks. However, the high error rate and the rapidly changing quality of the radio channels can be devastating for the transport of compressed video. In addition, the bounded playout delay for interactive video limits the effectiveness of retransmission-based error control. In this paper, we propose extending retransmission-based error control to provide different levels of protection to video packets through redundant retransmission on diverse paths. The mechanism factors in the importance of the retransmitted packets to the reconstructed video quality as well as the end-to-end latency constraints to minimize the overhead and maximize the reconstructed video quality at the receiver. We evaluated the effectiveness of the mechanism under different network conditions. Simulation results show that the proposed retransmission mechanism maintains the video quality under different loss rates and mobility speeds, with less overhead compared to error control methods that depend on controlling the intra-update rate. In addition, the mechanism is shown to be effective for single layered as well as multi-layered coded video.

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