No abstract

Video-on-demand (VOD) designs typically feature either request or broadcast architectures. Both have limitations. Request architectures experience a limit in the number of clients that can be adequately serviced. Broadcast architectures require large, often unavailable, bandwidth. In addition, it is difficult to limit viewing to a target audience. In this paper, we present a new architecture for a metropolitan VOD service that we name requestcasting. Our architecture combines the two general approaches of request and broadcast, but not their respective limitations. With the requestcast architecture, we implement an improved pyramid broadcasting protocol. Our synchronized method of employing pyramid broadcasting is key to providing robust VOD service.