Recently, the demand for content delivery in wired/wireless heterogeneous networks is increasing at a rapid pace. Content Distribution/Delivery Networks (CDNs) are considered to be one of the best solutions for dealing with this increasing demand. In this paper, we point out that the performance of a CDN typically degrades in such heterogeneous environments due to the changes in not only user demand but also wireless mobility, which triggers unexpected fluctuations in traffic. Wireless users, roaming between different access networks, may contribute to sudden and unexpected demand spikes in certain parts of the content delivery system. To address this issue, we develop a cooperative server selection scheme, which is designed to maximize robustness to such changes with the cooperation between the content delivery system and its users. The performance of our proposal is evaluated by extensive computer simulations. The evaluation results demonstrate that our proposed scheme effectively makes the considered content delivery system resilient against request fluctuations while minimizing system overloading.
- Content distribution/delivery networks
- cooperative system
- heterogeneous networks and load balancing
- server selection