How does ON DEMAND work? (1 Viewer)

[Michael Giusto]

Hey there all.

Is there a post out there on these forums that explains how ON DEMAND works via digital cable?

A couple colleagues and I were talking about this at lunch and one of them believes that all of the ON DEMAND content is delivered down to a hard-drive in the cable box on off hours. I thought this to be a bit excessive as the number of ON DEMAND items would be just too much to download to a hard-drive constantly to every subscriber, whether they watch the content or not.

The argument then went to "How can you fast forward through it then, if you don't already have the content stored somewhere."

Can anyone point me to a How ON DEMAND Works article or thread?

Thanks so much!

Michael

 

[Don Black]

The content is stored at the head end which is basically your local cable substation (think little brick building in each neighborhood (not quite that prolific but you get the picture)). You can fast forward because the video is basically just streaming from the head end and the bandwidth is readily available.

Nothing is stored on your cable box although hybrid VOD/PVR devices/services are in the works.

 

[Steve Felix]

I'm not an expert on the subject but I think it's as simple as streaming the video as you would on the internet. The difference is that the cable system has a huge amount of bandwidth for video... consider that you're always pulling down hundreds of channels whether you're watching them or not.

I have also wondered how much the "on demand" servers can possibly take, though. It does seen like a certain number of users would bring the system to a halt. There is probably a limit to the number of connections allowed, but I am again just guessing. What I can say for certain is that the content is not stored on a hard drive on the user end!

This is about VOD and this is about cable technology in general.

 

[Don Black]

Steve: Bandwidth and storage limitations abound which is why we can't access "every movie ever made" as the Qwest commercials hinted at. But the tiny demand is such right now that we aren't even close to pushing the limits of such technological limitations.

The cable cos are pushing VOD in a big way since it's something that the satellite providers can't offer (no return path). Which, of course, is why the sat cos are pushing PVRs (more successfully).

 

[Luis C.]

I've tried it for three days now and it works great! Comcast still has to work on their selection but they are doing good so far.

You can find whatever in VOD: Sports, shows, variety programs, movies (pay per view), etc...

 

[SteveK]

Don - I talked to a rep at DishNetwork the other day, and he claims they are working on a VOD setup in order to be competitive with cable. Of course, you always have to take everything with a grain of salt, but he indicated it should be available sometime next year. If it actually happens, it will be interesting to see if it offers as many features (rewind, pause, etc) as cable VOD. Recording something on PVR is ALMOST the same as VOD, but not quite.

Speaking of recording, can the VOD programs be recorded onto PVR or DVD recorders?

Steve K.

 

[Eric_Connelly]

Its about time

I remember reading many many years ago about Tiger I think, it was MS's on demand video idea, this was before DSL, cable, and bandwidth for this type of system was unimaginable, not to mention the data storage requirements...it included a set top box annd a server substation in each neighborhood to serve homes. Neat idea but no one had any idea on how it would work with the technology of the day.

Anyone remember the real code name for MS's future of TV back in the early 90's?

 

[Don Black]

Steve: It's quite possible that Echostar is working on some sort of VOD hack similar to their "on-demand" games. But at the end of the day, DBS simply doesn't have a high-bandwidth return path.

 

[SteveK]

Don - I agree, and that's why it will be interesting to see what feaures it is lacking, if in fact it is ever made available. I think On Demand could be a great selling point, just as the cable companies are beginning to push it. It makes a lot of sense, as you are not tied to a specific schedule, but can choose from any available movie at any time, 7:13 PM, for example. I'm even contemplating switching from Dish to cable, partly for VOD features among other considerations. But I'm not sure it's worth the possible tradeoff in picture quality and decreased channel selection. I'll have to check with my cable company to see exactly what they offer, and check back with Dish to see if they have any idea when the VOD might become available. I'll probably stick with Dish, and simply hope they offer a full featured VOD soon.

Steve K.

 

[Don Black]

I hear ya. VOD is so clunky right now that I haven't touched it besides just general curiosity. DVD and ReplayTV work well for me. If I owned my house, I would go satellite instead of cable.