Optimal Stream Merging for Media-on-Demand

Richard E. Ladner

As the Internet grows so does the desire for on-demand streams of many types: movies, songs, news stories, stock quotes, and others. The popularity of a specific stream may be so high that multicasting may be the only way to satisfy the demand. In addition, clients requesting a stream will want service as quickly as possible. This may require repeated multicasts of the same stream to satisfy the delay guarantees. Stream merging has the potential to help solve the bandwidth problems created by heavy, low delay, demand for the same stream. In this talk we describe the stream merging technique and how it can be used to reduce bandwidth requirements at the stream server. We describe a new quadratic off-line algorithm for minimizing bandwidth. We describe the optimal solution for the fully loaded case, where streams are requested at unit time intervals. It turns out that the Fibonacci numbers play an important role in the analysis of the fully loaded case. This is joint work with Amotz Bar-Noy of AT&T Labs-Research.