Multicast with Cache (Mcache): An Adaptive Zero-Delay Video-On-Demand Service

This paper presents a closed-loop (demand-driven) approach towards VoD services, called multicast with caching (Mcache). Servers use multicast to reduce bandwidth usage by serving multiple requests using a single data stream. However, this requires clients to delay receiving the movie until the multicast starts. Using regional cache servers, Mcache removes initial playout delays at clients, because clients can receive the prefix of a requested clip from regional caches while waiting for the multicast to start. In addition, the multicast containing the later portion of the movie can wait until the prefix is played out. While this use of caches has beep proposed before, the novelty of our scheme lies in that the requests coming after the multicast starts can still be batched together to be served by multicast patches without any playout delays.