# How does Video on Demand Work?



## airpolgas (Aug 13, 2002)

A friend of mine who is a sub to Comcast said that he tried using VOD over the weekend, and was quite excited about it. What bothers me is that he does not have a DVR receiver. He instead has a stand-alone Tivo for his DVR needs.

With that in mind, how was he able to watch VOD? He claims that it took less than 10 seconds for the "movie" to get ready. I did not use the term "download" because I am not sure it does that. He claims his box does not have a hard drive. He associates hard drives with receivers with DVR capabilities, and frankly, so do I.

On top of that, he said that he can fast forward and fast rewind through the movie, and when he wanted to stop watching, it saved the movie in case he wanted to continue watching at a later time.

Can someone elaborate on the technology for VOD or maybe a link to one? The google results I get mostly suggests having a hard drive on the user end.


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## Cyclone (Jul 1, 2002)

Basically, the Movie is kept on a Hard Disk in a Video Server back at the cable company. We he plays the movie, it is sent on a signal just for him. We he pauses/rw/ff/play all those commands are sent to the video server, which in turn stops/plays/etc ... The only thing required here is two way communications between his Set Top Box and the Video server back at the cable company. The server knows if he hasn't finished watching the movie and will keep it "active" on his list for a day or two, and then will remove it from the list once it has expired. He of course can always order it again.

Expect this to fully replace the current "start time" PPV in the future. Also expect any "Free VOD" material to ulitimately become "Fee based VOD".

Satellite (DBS) providers can not offer this way of providing VOD. They just do not have the two way communications built in the STBs. Plus the Bandwidth required for 10 millions customers from a few satellites is much different than the segmented Cable networks which only serve a few thousand on any one segment. The DBS providers in turn will tell your DVR to "record" VOD offerings while you are not watching any programs. They will be saved on your Hard Disk. If you chose to buy a VOD program, it will be presented from these programs that your DBS DVR has previously recorded.


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## airpolgas (Aug 13, 2002)

I was just about to ask about multiple subscribers, but then I noticed you edited your response.

So in a sense:

Cable VOD = Stream and watch.
Satellite VOD = Download and watch.

Thanks.


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## the_bear (Oct 18, 2004)

There are 2 big websites with similar VOD service for those of us without cable.

http://www.cinemanow.com
http://www.movielink.com


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