Multicast True VoD Service

Definition: The conventional true VoD system uses one dedicated channel for each service request, which offers the client the best QoS and interactive services, while multicast true VoD offers more efficient data transmission.

Video-on-Demand (VoD) service allows remote clients to play back any video from a large collection of videos stored at one or more video servers in any mode at any time. VoD service is usually long-lived and real-time, and requires high storage-I/O and network bandwidths and needs to support VCR-like interactivity. A VoD system is usually designed with a focus on system cost and client-perceived Quality-of-Service (QoS). Key cost components are the video server capacity, storage-I/O bandwidth, network bandwidth and throughput, and customer premise equipment (CPE). VoD clients’ QoS is related to service latency, interactivity, and playback effects. Usually, there is a trade-off between clients’ QoS and system costs. The True VoD (TVoD) service supports all of the control functions, and is an ideal service for customers. The conventional TVoD system uses one dedicated channel for each service request, which offers the client the best QoS and interactive services. However, it incurs high system costs, especially in terms of storage-I/O and network bandwidth. Moreover, the conventional VoD service has poor scalability and low cost/performance efficiency. Efficient solution to improve VoD systems is to use multicast.

Multicast offers efficient one-to-many data transmission and thus provides the foundation for various applications that need to distribute data to many receivers in a scalable manner. It reduces both the server-side overhead and the overall network load. A survey of multicast VoD services is given in.

(This short article has been adapted from).