Dynamic segment based proxy caching for Video on Demand

In this paper, we propose a novel proxy caching scheme for video on demand (VoD) services. Our approach is based on an observation we have made during subjective VoD performance evaluation tests. We have found that when users are seeking for some specific content, they pay most attention to the initial delay, while a small shift of the starting point is acceptable. Meanwhile, the random access using the slide bar sometimes even makes this small shift unnoticeable. Based on this fact as well as the popularity of video segments, we propose a dynamic segment based caching algorithm. It adjusts the segment size according to its hitting rate and maximizes the user satisfaction by optimally trading off between the initial delay and the deviation of the starting point. Our experimental results show a significantly improved user satisfaction compared to previous caching approaches.