摘要 : Video communications over wireless networks often suffer from various errors. A novel video transmission architecture is proposed to meet the low-delay and error-robust requirement of wireless video communications. This architectu... 展开 Video communications over wireless networks often suffer from various errors. A novel video transmission architecture is proposed to meet the low-delay and error-robust requirement of wireless video communications. This architecture uses forward error correction coding and automatic repeat request (ARQ) protocol to provide efficient bandwidth access from wireless link. In order to reduce ARQ delay, a video proxy server is implemented at the base station. This video proxy not only reduces the ARQ response time, but also provides error-tracking functionality. The complexity of this video proxy server is analyzed. Experiment shows that about 8.9% of the total macroblocks need to be transcoded under a random-error condition of 10-3 error probability. Because H.263 is the most popular video coding standard for video communication, we use it as an experiment platform. A data-partition scheme is also used to enhance error-resilience performance. This architecture is also suitable for various motion-compensation-based standards like H.261, H.263 series, MPEG-1, MPEG-2, MPEG-4, and H.264. For "Foreman" sequence under a random-error condition of 10-3 error probability, luminance peak signal-to-noise ratio decreases only 0.35 dB, on average. 收起