Cooperative Video Streaming Mechanisms with Video Quality Adjustment

The proxy technique is originally developed for WWW system, but we expect it is useful to improve the performance and quality of video streaming applications. Especially, if each proxy is capable of adapting incoming or cached video data to user’s demand, user’s QoS requirements on video streams can be fully satisfied. On receiving a request from a user, the proxy first checks the cache. If a cache miss occurs, it retrieves the video block of higher quality from the origin server or proxies nearby. For this purpose, the proxies communicates with each other and find an appropriate server by taking into account the transfer delay and the offerable video quality. We show that our proposed mechanisms are effective in avoiding freezes during the video playback and providing the clients with high-quality video streams.