Streamed Multimedia Presentation for Low-bandwidth Mobile Terminals: a Virtual Machine Approach

We present a simple and robust client–server architecture for streaming synchronized multimedia presentations to mobile terminals over a low-bandwidth connection. The server is similar to a compiler, and translates high level SMIL descriptions of multimedia presentations into low level content instructions. The client resembles a virtual machine, operating on content instructions that control the multimedia presentation. The compilation process on the server is designed to reduce the buffering on the client, and hence reduce the start-up delay for the user. Since the server takes the larger burden of the total work, the client can be kept simple. Upon request, the server assembles a sequence of content instructions corresponding to a multimedia presentation, under the optimistic assumption of a minimum communication bandwidth, and streams the content instruction sequence to the client without any other feedback mechanism than flow control. If the bandwidth assumption holds, the client renders the presentation as specified; otherwise, it is able to make controlled pauses in the presentation. We also describe a specific news application based on our architecture.