Multimedia object caching, by which the same multimedia object can be adapted to diverse mobile appliances through the technique of transcoding, is an important technology for improving the scalability of web services, especially in the environment of mobile networks. In this paper, we address the problem of cache replacement for multimedia object caching by exploring the minimal access cost of caching any number of versions of a multimedia object. We first present an optimal solution for calculating the minimal access cost of caching any number of versions of the same multimedia object and its extensive analysis. The performance objective is to minimize the total access cost by considering both transmission cost and transcoding cost. Based on this optimal solution, we propose an efficient cache replacement algorithm for multimedia object caching. Finally, we evaluate the performance of the proposed algorithm with a set of carefully designed simulation experiments for various performance metrics over a wide range of system parameters. The simulation results show that our algorithm outperforms comparison algorithms in terms of all the performance metrics considered. © 2007 CRL Publishing Ltd.

link_to_subscribed_fulltext