A novel stream merging algorithm for VOD servers

Hierarchical stream merging is a technique for efficiently delivering popular media on demand using multicast and client buffers. Though there has been much theoretical study around the performance of stream merging, implementation issues were rarely discussed. We argue that the frequent alterations of client behavior hinder the feasibility of traditional stream merging methods. To address this problem, we proposed a new algorithm named CIM (client initiated merge). Despite a minor compromise in server throughput, the new approach greatly reduces system complexity and control overhead. Working on an event-driven mode, it readily accommodates VCR features such as jump and stop. Both simulation and experimental results are given, confirming that the sacrifice in overall server cost is trivial in comparison with the advantages it introduces.