Video streaming systems with cooperative caching mechanisms

In this paper, we investigate mechanisms for the video streaming system where proxies cooperate to provide users with low-latency and high-quality services under heterogeneous and mobile environment where hosts have different capabilities and dynamically change their locations. The proxy is capable of adapting incoming or cached video data to user's demand by means of transcoders and filters. With such proxies, heterogeneous QoS requirements on the delivered stream can be fully satisfied by preparing high-quality video data in the local cache buffer and adjust them to the requirements. On receiving a request from a user, the proxy first checks the cache. If no appropriate data is available, it retrieves the video data of the satisfactory quality from the video server or proxies nearby. The proxy communicates with the others and finds an appropriate one for data retrieval by taking into account the transfer delay and the video quality. We propose a cooperative video caching mechanism for the video streaming system and evaluate the performance in terms of the delay introduced and the video quality.