Multicast Content Distribution Over IP Networks

An IP-based TV (IPTV) service consumes a huge bandwidth to be delivered to the clients. Currently, each video demand is handled individually and independently of other demands for the same content. Consequently, duplicate copies of the same packets are transmitted along the same links nearly at the same time, and the mirror sites of the content provider have to serve multiple requests for the same data. Near Video- On-Demand (NVOD) service, as opposed to Video-On-Demand (VOD) service, is characterized by the property that the clients receive the requested information simultaneously, at a time determined by the service provider. This property is used in this study to develop an application layer method for providing a low- cost, per-per-view video service over IP networks. The proposed method is particulary suitable for download requests for popular content, for applications that users can subscribe to ahead of time, pay-per-view applications, and for a session whose time duration is relatively long. Examples for such applications are an NVOD service, live video streaming of news, sport and music events, download requests of popular video and music files, and ahead of time reservation of an IPTV service. At highly loaded time periods, the proposed method offers a reduced service latency, as well as a significant increase in the number of clients served simultaneously.