Hierarchical network architecture for layered video streaming

This paper investigates the performance of a hierarchical on-demand video streaming system using layered videos in a heterogeneous network environment. To efficiently utilise the limited capacity in a proxy server, a new proxy replacement algorithm called Simple Count (SC) is firstly developed. The proposed SC algorithm aims at maintaining the most popular video layers at the proxy by using a newly defined popularity measure that can accurately keep trace on the change of video access pattern. Simulation results show that the SC method performs better than some existing methods in a dynamic network environment. An analytical model is then developed to further investigate the performance of the system in terms of blocking probability. The results reveal that the system can provide customers with more than 90% of the video quality that they request even if the workload of the system is very heavy.