Posted by Bill Fright on 11/13/05 18:46

AnthonyR wrote:

> "Bill Fright" <billfright@austin.rr.com> wrote in message
> news:8vrdf.7731$th3.2585@tornado.texas.rr.com...
>
>>
>>AnthonyR wrote:
>>
>>
>>>"Bill Fright" <billfright@austin.rr.com> wrote in message
>>>news:BEKcf.2527$th3.2217@tornado.texas.rr.com...
>>>
>>>
>>>>AnthonyR wrote:
>>>>
>>>>
>>>>
>>>>><marks542004@yahoo.com> wrote in message
>>>>>news:1131572540.281420.97030@g44g2000cwa.googlegroups.com...
>>>>>
>>>>>
>>>>>
>>>>>>Hi,
>>>>>>
>>>>>>This may be off topic - please suggest other newsgroup if applicable.
>>>>>>
>>>>>>There was a report on my local TV news about several cable companies
>>>>>>carrying several TV series on-demand.
>>>>>>
>>>>>>Does anyone know the carrying capacity of a cable network for this type
>>>>>>of thing.
>>>>>>
>>>>>>When I was involved with computer networking 15 years ago video
>>>>>>conferencing always wound up killing the networks.
>>>>>>
>>>>>>I know speeds have gone up considerably but there must be a point at
>>>>>>which the on-demand capacity breaks down.
>>>>>>
>>>>>>
>>>>>>regards
>>>>>>
>>>>>
>>>>>
>>>>>Not sure on the answer but i thought the same thing.
>>>>>In fact Time Warner offers me so many OnDemand channels now it's
>>>>>impossible to watch a fraction every day.
>>>>>Besides Movies from HBO, Showtime, TMC etc... they offer A&E, CNN,
>>>>>FoodNetwork, Comedy Central you name it
>>>>>everything OnDemand now. I don't know their limits but so far everything
>>>>>runs pretty smoothly.
>>>>>I wonder after every single customer goes digital, uses broadband and
>>>>>movies over IP at the same time what will happen?
>>>>>
>>>>>AnthonyR.
>>>>>
>>>>>
>>>>
>>>>To me it's all about the bandwidth. Sure they can cram more programs into
>>>>the pipe as they continue to lower the quality. Any of you guys who are
>>>>compressing your high quality shows to mpg2 (DVD) know what I'm talking
>>>>about. The shorter the show the higher the quality.
>>>>
>>>>Maybe I have too much time on my hands or I'm a huge nerd but I love to
>>>>go to retail home theater stores and talk bandwidth with people. My
>>>>favorite is to have them show me HD via satellite.
>>>>
>>>>So nothing will happen (as far as a major system crash) they'll just keep
>>>>lowering the bit rate and decrease the overall quality to fit more
>>>>programming in the pipe.
>>>>
>>>>Next time I hear digital quality I'm gonna throw my cell phone at
>>>>somebody.
>>>>
>>>
>>>Bill Good Point,
>>>But normally a cable company can squeeze say 800 channels into a cable
>>>and send that to 8 million people in nyc, right?
>>>But if all 8 million people ask to see an On Demand Movie or show, each
>>>one starts and pauses it separately, so now how does the cable company
>>>fit the 800 channels plus the 8 million movies all playing into that
>>>bandwidth, squeeze it more?
>>>wow, that's a great trick if they can pull it off.
>>>
>>
>>Okay now I have some home work!!! I'll look into this and figure it out.
>>But I suspect I know the answer already. I'll bet the on demand programs
>>reside in RAM type memory and since it can be accessed at different points
>>simultaneously and the bandwidth is low it will accept several "demands"
>>at one time. For example if you have a terabit of RAM on a server you
>>could have people access it simultaneously all a across a network.
>>
>>I will look in to this.
>>
>>
>>>I suspect, they have many distribution points, so each neighborhood
>>>handles it's own Ondemand bandwidth independently of the entire system,
>>>sort of how cell phone companies have many cells. But I don't really
>>>know, just guessing here.
>>>
>>>Your comment about "hearing about digital quality" is funny. That's how
>>>they sell us new stuff, promise better quality to get us to change then
>>>deliver less. Overhaul it still is better than I was getting with my
>>>rabbit ears years ago, even with occasional digital breakup. :) I don't
>>>miss the snow and double images and ghost of analog tv.
>>>I wonder how much better digital tv transmission will be once they
>>>convert over?
>>>
>>>AnthonyR.
>>>
>>>
>>
>>Exactly, less quality but they sell it like it's the best ever.
>>
>>
>>You just touched my favorite point. Put a pair of studio monitors side by
>>side with a waveform/vector scope for each one. If your antenna receives
>>the analog signal correctly it will have a much higher resolution than a
>>cable or satellite signal. The key here of course is the antenna. This
>>goes double for HD. So the answer to your question is yes, digital over
>>the air transmission is going to suck just like cable and satellite
>>because it's going to be compressed the same way. So in 2008 when they
>>pull (supposedly) the plug on analog transmission you'll lose the highest
>>quality you could ever receive at your home as a consumer. Like the plague
>>mpeg2 is coming to get you!
>>
>>Perhaps I'm bordering on insanity but the pixilation and blurred
>>(averaged) back grounds are artifacts I don't find acceptable in a video
>>signal. Of course my production company delivers mpeg2 products just like
>>everyone else but I never turn in mpeg2 products for broadcast.
>>
>>Hell I'm so determined I still shoot on Betacamsp over DVcam even though
>>it's much less convenient.
>>
>
>
> Bill.
> Thanks for the detailed reply.
> If you do find out more on this OnDemand scheme, I'd be very interested.
> I understand what you are saying.
>
> AnthonyR.
>

I can't guarantee the accuracy but this looks pretty plausible to me.

http://www.cableforum.co.uk/board/showthread.php?t=22345

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