Efficient contents delivery method with scheduled unicast and multicast

We propose the efficient contents delivery method with scheduled unicast and multicast to reduce the load of contents server and network congestion. In our proposed method, the timing of transmitting contents is arranged when many users access the contents in short period of time. Furthermore, the method of transmitting contents is switched from unicast to multicast. We evaluate the performance by computer simulation in terms of the unicast holding time, the threshold of switching from unicast to multicast, and the multicast delivery interval with the parameters of the content size and the access traffic. The simulation results show that the unicast holding is effective for the relatively-little contents and average download time can be reduced in our proposed method. The optimum switching time and the multicast delivery interval are also derived for a typical model.