HAG-based application layer multicast system for streaming media

A fault-tolerant system, the hierarchical arrangement graph (HAG), was developed for application layer multicast to support streaming media service. In HAG, the hosts are grouped into many arrangement graphs, with these arrangement graphs assembled into a tree structure. Independent multicast trees can be embedded into HAG to deliver different descriptions of the MDC media streaming. With HAG, a single host failure disrupts only one multicast tree, without affecting the data delivery in the other multicast trees which improves media delivery fault-tolerance. Simulation results show that HAG achieves up to 20% improvement of the average received bitrate compared with the traditional multicast strategy with a 5% host failure probability. In addition, HAG can cluster adjacent hosts into the same arrangement graph to improve the data delivery efficiency.