or Connect
AVS › AVS Forum › HDTV › HDTV Technical › Bandwidth of various HDTV formats
New Posts  All Forums:Forum Nav:

Bandwidth of various HDTV formats

post #1 of 16
Thread Starter 
I got cut off from Comcast a few months ago. No, this post isn't about that, but I do question the legality of their 250gb cap.

I want to know how much data is sent to feed an HD-TV, if you were to watch it 24/7.

I know that not all stations send the same signals, and that not all channels are even HD. I've done some reading on HD-TV and found that there are standards, but the bitrate and resolution aren't always followed.

Does anyone have experience with type of video feed Comcast puts out, and how much bandwidth it uses?

My assertion is that, because High-definition content on the internet (legal or non-legal, either way) is a threat to their cable service, Comcast has created a usage limit that is less than the amount of data transferred, if a person were to watch it entirely on their HD-TV. This implies anti-competitive policies, which is at the heart of the matter.

Specifically, if a person were to watch HD .ts 24/7 on their television, would it be significantly more monthly bandwidth than if a person were to stream netflix or watch legal HD content over networks like Vuze?

Thanks for your help.
post #2 of 16
Quote:
Originally Posted by Tiberiusfury View Post

I got cut off from Comcast a few months ago. No, this post isn't about that, but I do question the legality of their 250gb cap.

I want to know how much data is sent to feed an HD-TV, if you were to watch it 24/7.

I know that not all stations send the same signals, and that not all channels are even HD. I've done some reading on HD-TV and found that there are standards, but the bitrate and resolution aren't always followed.

Does anyone have experience with type of video feed Comcast puts out, and how much bandwidth it uses?

My assertion is that, because High-definition content on the internet (legal or non-legal, either way) is a threat to their cable service, Comcast has created a usage limit that is less than the amount of data transferred, if a person were to watch it entirely on their HD-TV. This implies anti-competitive policies, which is at the heart of the matter.

Specifically, if a person were to watch HD .ts 24/7 on their television, would it be significantly more monthly bandwidth than if a person were to stream netflix or watch legal HD content over networks like Vuze?

Thanks for your help.

I would say that any local broadcast HD channel you watch on cable, has a higher Mbps(in my area double or triple) what the internet speed is capped out at, my local CBS comes close to using 16 or 18 Mbps whereas my internet is 6 Mbps with short bursts of 10 to 12 Mbps allowed for 30 seconds to a minute sometimes.
post #3 of 16
Usually, you have:

- Downloadable "HD" = ~5-8Mb/s max. That's roughly DVD bit rates. However, that's often H.264, Flash or Silverlight instead of MPEG2. So, even at the same rate, it can look a bit better than standard DVD.
- Cable/satellite HD = ~12-15Mb/s, depending upon provider. At the same bit rates, MPEG4 feeds will look better due to the more advanced codec.
- OTA = ~12-19Mb/s, depending upon whether the station has subchannels or not. Those are MPEG2.
- Blu-Ray = ~18-28Mb/s, depending upon content and the particular studio. A very few number of discs go a bit higher than that.
post #4 of 16
Quote:
Originally Posted by Tiberiusfury View Post

I want to know how much data is sent to feed an HD-TV, if you were to watch it 24/7.

I don't know if this is exactly what you are looking for, but when I record a program off-the-air to my PC, it takes an average of around 7GB per hour. So, for a full day, that would be 168GB. Expanding upon that, about 5TB for a month.
post #5 of 16
Kind of off topic to the question, but relevant to the original post:

The problem with the original posters statement though, is that TV is multicast whereas internet TV is not. So it is not fair to compare the bandwidth usage as far as the cap is concerned.
post #6 of 16
Thread Starter 
Quote:
Originally Posted by NetworkTV View Post

Usually, you have:

- Downloadable "HD" = ~5-8Mb/s max. That's roughly DVD bit rates. However, that's often H.264, Flash or Silverlight instead of MPEG2. So, even at the same rate, it can look a bit better than standard DVD.
- Cable/satellite HD = ~12-15Mb/s, depending upon provider. At the same bit rates, MPEG4 feeds will look better due to the more advanced codec.
- OTA = ~12-19Mb/s, depending upon whether the station has subchannels or not. Those are MPEG2.
- Blu-Ray = ~18-28Mb/s, depending upon content and the particular studio. A very few number of discs go a bit higher than that.

So it seems the consensus is that both regular and HD-TV take up quite a bit of bandwidth, and would far exceed the 250gb monthly limit if watched 24/7?

Does anyone have numbers for the typical Comcast HD channel?

Thanks for you excellent responses, by the way.
post #7 of 16
Quote:
Originally Posted by Tiberiusfury View Post

My assertion is that, because High-definition content on the internet (legal or non-legal, either way) is a threat to their cable service, Comcast has created a usage limit that is less than the amount of data transferred, if a person were to watch it entirely on their HD-TV. This implies anti-competitive policies, which is at the heart of the matter.

Your assertion is reasonable -- I think that it implies anti-competitive policies, as well. And I'll note that I've heard suggestions elsewhere that cable companies are starting to feel threatened by video over the Internet as a potential competitor.

Unfortunately, after decades of weakening anti-trust enforcement, anti-competitive behavior can be quite legal.
post #8 of 16
Quote:
Originally Posted by Tiberiusfury View Post

So it seems the consensus is that both regular and HD-TV take up quite a bit of bandwidth, and would far exceed the 250gb monthly limit if watched 24/7?

They key fact is:
Quote:
Originally Posted by acs12798 View Post

TV is multicast whereas internet TV is not.

You can't simply compare the two on a byte-by-byte basis. It doesn't work that way.
post #9 of 16
Quote:
Originally Posted by Jeremy W View Post

They key fact is:

You can't simply compare the two on a byte-by-byte basis. It doesn't work that way.

Neither does On-Demand, but I don't hear anything about capping it.
post #10 of 16
Quote:
Originally Posted by rebkell View Post

Neither does On-Demand, but I don't hear anything about capping it.

Comcast sets bit rates and resolutions for On Demand, so it's capped by nature.
post #11 of 16
Quote:
Originally Posted by acs12798 View Post

Kind of off topic to the question, but relevant to the original post:

The problem with the original posters statement though, is that TV is multicast whereas internet TV is not. So it is not fair to compare the bandwidth usage as far as the cap is concerned.

This is the important point. As long as we are not talking about SDV, If one viewer is watching a movie on HBO or if everybody is watching it, the "load" on the cable system does not change. As the internet downloads of each subscriber increases, the "data load" increases on the entire system.
post #12 of 16
Thread Starter 
Quote:
Originally Posted by Jeremy W View Post

They key fact is:

You can't simply compare the two on a byte-by-byte basis. It doesn't work that way.

Don't cable internet and digital television run across the same infrastructure?

I get a cable from my wall that, depends on what it is plugged into, can either provide data to my TV or bits to the internet.

Granted, I'm not saying they're exactly the same. Comcast probably compiles all of the signals to local stations, then sends them to the neighborhoods, which is much less bandwidth intensive than downloading a movie from Sweden.

However, as far as product vs product goes, internet high definition video is an inferior product because Comcast has created artificial restrictions upon it, which they have not done so for their competing product.

Maybe I just have way too much time on my hands, but I think it would be interesting to enlist the help of my campus law office to see if I could challenge them in court.

And the last thing:
I don't actually hate Comcast. I was using Qwest previously, which was nightmarishly slow after seeing Cable. Comcast has usage limits (and previously forged ********** packets), but they're not draconian like in Australia, nor have I ever been contacted by Comcast in regards to the content of my usage; just the volume of it.
post #13 of 16
Thread Starter 
Quote:
Originally Posted by Oxb View Post

This is the important point. As long as we are not talking about SDV, If one viewer is watching a movie on HBO or if everybody is watching it, the "load" on the cable system does not change. As the internet downloads of each subscriber increases, the "data load" increases on the entire system.

Both the internet and cable come out of the coaxial cable though, so even if the volume cable traffic is routed efficiently, it still cuts down on the usage available for internet, right?
You guys aren't saying that, once the cable goes to the box outside my house, it is split into internet and cable?

I would imagine that there wouldn't be any separation between them until it went to their local substation, at least.
post #14 of 16
The cable out of your wall outlets have both cable and internet service. They operate at different frequencies you can use a frequency sensitive splitter if you are going to connect a TV and your wireless router to the same wall outlet so as to give better signal strength to each then you would with a splitter that provides the same strength to each output.
post #15 of 16
Quote:
Originally Posted by rebkell View Post

Neither does On-Demand, but I don't hear anything about capping it.

On Demand is a regular TV channel, it doesn't use Internet bandwidth. There are a certain number of TV channels set aside for On Demand. If they're all in use, you won't be able to watch it.
post #16 of 16
Quote:
Originally Posted by Tiberiusfury View Post

Both the internet and cable come out of the coaxial cable though, so even if the volume cable traffic is routed efficiently, it still cuts down on the usage available for internet, right?
You guys aren't saying that, once the cable goes to the box outside my house, it is split into internet and cable?

I would imagine that there wouldn't be any separation between them until it went to their local substation, at least.

The coaxial cable does not "know" if it is carrying video or digital data via its RF capability. One way to look at it is that it is carrying various channels. One channel might be carrying the analog version of your local NBC affiliate and another channel might be carrying a analog local access channel. (if you want to get worked up over wasted bandwith, you might start here) Each channel can carry one analog television signal. Whether anyone is watching it or not, that bandwidth is being used. A channel can carry digital information, like a QAM channel carrying 10 or so SD video streams or 2 HD streams (or 3 squished ones). Again whether or not anyone is watching them, that bandwidth is being used. Other channels do get shared by various users - this is probably what you have thinking about. A cable system can use one channel for the internet services offered to subscribers. When you and your neighbors are downloading files from the internet, you are sharing that channel with your neighbors - not with video services.
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: HDTV Technical
AVS › AVS Forum › HDTV › HDTV Technical › Bandwidth of various HDTV formats