UPGRADING THE SERVICE CAPACITY OF VIDEO-ON-DEMAND SERVERS WITH MEMORYBUFFER

In this paper, we propose a new approach to exploit semiconductor memo ry to upgrade the service capacity of video-on-demand systems. The bas ic idea behind this so-called Generalized Relay Mechanism is that if w e can relay the data of frequently accessed programmes from one access request to another, then we can improve the service capacity of the s ystem without requiring higher disk bandwidth. The design of the Gener alized Relay Mechanism is aimed at optimizing allocation and trade-off of the memory resource and the disk bandwidth resource. A simulation- based study shows that the Generalized Relay Mechanism is a very compe titive alternative in comparision with simply incorporating more hard disks. If compared with an intuitive approach of utilizing memory buff er that always fills up the memory with most frequently accessed progr ammes, the Generalized Relay Mechanism enjoys an advantage in terms of cost.