Prioritized opportunistic network coding for video streaming over wireless multi-hop networks

A prioritized opportunistic network coding scheme is proposed to solve the mismatch problem of coding opportunities between multiple streams. Packets with different priorities are treated differently. The generation-based intra-session coding with redundancy is performed at the source nodes to increase transmission reliability. At the intermediate nodes, the packets with highest priority are re-encoded with redundancy data within the generation, those with lower priority are performed XOR operation with the packets of another stream, and the remaining packets are forwarded directly or discarded selectively. This strategy ensures that the base layer packets of the streaming are received by the destination node with high probability and that the number of sending packets is reduced while taking full advantage of the limited network bandwidth. Experimental results show that the proposed scheme enhances the video quality effectively, and improves the average peak SNR by more than 2 dB in a comparison with the existing opportunistic coding scheme.