Video on demand (VOD) is a system that allows the viewer to select and view video content through an interactive television network, and it is distinguished from the more usual television viewing be a higher degree of interactivity between the viewer and the material viewed: VOD gives its consumers nearly instant access to a range of recorded material, movies, games, interactive shopping, information and other services. The converging of television, multimedia and virtual reality is the technology behind video on demand.
There are two different models of video on demand: true video on demand (TVOD) and near video on demand (NVOD). Whereas near video on demand broadcast its videos and movies mainly at a set time, and often through multiple channels at multiple times, and the viewer can choose whether or not to watch it, true video on demand (TVOD) offers instantaneous response to the viewer within seconds from the time the program is requested to the time its being delivered so the viewer can choose to view any material at any time (Zhiqi and Songyo, 2003). Some TVOD systems also facilitate VCR/DVD functions where the viewer can choose to stop, fast forward, pause etc. the material. However, true video on demand is far more expensive to operate and requires a much greater network bandwidth and is therefore less common than near video on demand.
“A near video-on-demand (NVOD) is a more scalable approach by batching multiple clients to a shared stream or broadcasting videos� (Kwon and Yeom, 2003:1106), and thereby take up a lesser network bandwidth than the true video on demand systems. Even though video on demand has struggled with finding its market, it is believed that VOD will play a great role in the future movie and television industry as the technology develops and transmission through a greater bandwidth is possible. Both NVOD and TVOD are quite common on major airlines and hotels.
Simen Sjoelli 17:28, 27 Oct 2004 (EST)
