[rbaldwin]

Are there any plans for comcast to upgrade channels 1-99 to digital? If we are paying a digital premium should we not expect to get all in digital?


Is this a huge infrastructure problem?


rbaldwin

 

[patrickhurt]

I would guess because some people do not want a cable box to have cable.


Patrick

 

[miatasm]

Quote:

Originally posted by patrickhurt I would guess because some people do not want a cable box to have cable. Patrick

Hit the Nail on the Head, Patrick. It is possible to do what you ask but it would require a lot more bandwidth to become available. Comcast would have to send channels 1-99 out twice. One in analog & again compressed and modulated in digital. It would take up waaaaay too much unnecassary bandwith. It may happen waaaaay down the road but at that time everything will be HD, so either your tv will have a decoder built in so you won't need a box, or the box will have to come from your cable provider anyway, in order for you to view any programming......just like it used to be when CATV first started.....circle of life...I guess.....

 

[nabsltd]

Quote:

Originally posted by miatasm Hit the Nail on the Head, Patrick. It is possible to do what you ask but it would require a lot more bandwidth to become available. We would have to send channels 1-99 out twice. One in analog & again compressed and modulated in digital.

The real reasons that cable companies don't go to almost 100% digital is because they are afraid to lower the guaranteed subscription income at all, even though it would likely raise their overall income, and, in general, cable companies don't give a damn about picture quality.


Most cable companies with digital cable have a "basic analog", "extended analog", some "premium analog" (HBO, a channel or two of PPV, etc.), "basic digital", and lots of "premium digital". Rarely do they have "extended digital", because they save so much money in bandwidth by getting people to move to digital that giving them all the "regular" channels is a good encouragement.


Well, if the company would drastically cut back on what is available on "extended analog" without cutting the cost, and offer "basic digital" at not much more than "extended analog", and offer the first digital box for free, they could "force" lots of people to switch.


They would cover the costs of people cancelling cable altogether by getting lots more people subscribing to premium services because of the "10 channels of HBO" come-on. Also, by putting 50+ channels of PPV in front of people that absolutely could not buy it before, they might get some income from that. Then, there are the sports subscriptions.

Quote:

It would take up waaaaay too much unnecassary bandwith.

Again, only if the cable company is short-sighted. By lowering their total analog channel count to 36 (which is about the bottom limit with FCC rules about carriage), you would have lots of room for everything a cable company could want, and they even could give decent picture quality.

 

[UncD2000]

If the analog cable channels were converted to digital, the built-in tuners in our TV sets and VCRs would no longer be able to tune these channels. We would be unable to watch one channel and record another, unless we wanted to rent a digital cable box for every VCR. Our secondary TVs would need cable boxes too. Features like 2-tuner PIP would be useless. Also, the analog cable channels, typically 2-99, when tuned by the TVs built-in tuner, will have noticeably better PQ than the digital channels (100+) which are afflicted by all sorts of compression artifacts. The analog channels enjoy full 6 MHz bandwidth. The digital channels will have up to 12 channels squeezed into each 6 MHz slot. "Digital cable" never had anything to do with quality. It's all about quantity - how many extra-cost channels can be compressed into the minimal available bandwidth.

 

[Davenlr]

Ever consider if they Didnt have to use 6 MHz each for 98 analog channels, they would be able to use less compession on the digital ones?


Thats the main reason I subscribe to satellite. Its all digital for less cost per month than analog. If cable was all digital, with 1000 MHz of bandwidth to use, Ill bet they could blow satellite PQ away with room to spare.

 

[nabsltd]

Quote:

Originally posted by UncD2000 Also, the analog cable channels, typically 2-99, when tuned by the TVs built-in tuner, will have noticeably better PQ than the digital channels

This, of course, varies with the system. The analog channels on my parent's Time Warner system look pretty crappy. Since that area is not being served by satellite locals and the cable company with a monopoly, this leads to crappy picture quality on both digital and analog and a $60/month price tag for "basic" digital.


Quote:

The analog channels enjoy full 6 MHz bandwidth. The digital channels will have up to 12 channels squeezed into each 6 MHz slot.

This is a red herring. With a 6MHz slot able to hold 40Mbps with 256QAM, the channels shouldn't be much more compressed than DirecTV...averaging about 3.3Mbps. Why cable channels generally do look worse, I'm not really sure, unless they are stuffing 15+ channels into a 6MHz block.


Quote:

"Digital cable" never had anything to do with quality. It's all about quantity - how many extra-cost channels can be compressed into the minimal available bandwidth.

It would, however, if the cable company would just ditch (most of) the analog channels and move them to digital.


A 750MHz cable plant can do 5,000Mbps total bandwidth if they convert to full digital. Give 5Mbps average to 500 SD channels--150 PPV, 150 "premium" (HBO, porn, etc.) channels, and 200 "basic" (ESPN, Disney, etc.) channels--and you use up 2500Mbps. Then, you can have 50 HD channels to use up another 1000Mbps, leaving 1500Mbps to do all sorts of cool things, or to hold 37 analog channels.


Notice that I am grossly overestimating channel count of available channels...there aren't anywhere near 50 HD channels, or 150 premium channels that a cable company can even buy. Even so, you end up with better quality than DirecTV (damn near DVD, especially if you add in statistical multiplexing) and a lot more channels.


Quote:

Originally posted by Davenlr If cable was all digital, with 1000 MHz of bandwidth to use, Ill bet they could blow satellite PQ away with room to spare.

Absolutely correct, as my analysis shows.


Thus, "digital cable" is not about channel count. If it were, going even more digital would be the obvious step.

 

[UncD2000]

The "digital cable" I referred to above is not the HDTV-capable 256QAM, but the obsolescent system which TCI of Illinois rolled out here five years ago. I placed the phrase in quotes to point out that "digital" was (and is) being used deceptively to suggest improved PQ. At that time, about 2 years prior to the fiber optics system upgrade, the entire 54-468 MHz bandwidth was occupied by analog channels, so three of these were cannibalized to carry 36 compressed digital channels. I accepted the initial special-rate offer because Sci-Fi Channel was one of the new offerings. I cancelled after my special rate expired because of the pathetic picture quality. The program guide, however, was excellent. The same General Instrument digital cable box is still in use here by AT&T/Comcast. It does not have DD 5.1 audio. The PQ may be better now since this system was upgraded to fiber optics about 3 years ago. The analog PQ was quite good after the upgrade. I am not currently a cable subscriber; DirecTV and OTA are fine for now. Eventually I'll have to return to cable, however, because DirecTV just doesn't have the HDTV capacity to carry even the services that have already been announced. The AT&T/Comcast system here is currently in beta testing of its HDTV package. It has been carrying one 8vsb channel (WBBM-DT CBS which is difficult to receive OTA) for about two years.

 

[nabsltd]

Quote:

Originally posted by UncD2000 The "digital cable" I referred to above is not the HDTV-capable 256QAM

You don't need 256QAM to do HD over cable. 64QAM can be used, as can 8VSB. It's just that 256QAM has better bandwidth utilization for a system that doesn't have to deal with OTA-style interference.[/b][/quote]

 

[trbarry]

I rather like it the way it is. I have my HDTV, HTPC, and HD cable box in the family room receiving digital. But I also have my Tivo and other VCR's and TV's all over the house that can get the basic channels in analog.


And with Comcast here in Detroit my Tivo analog recording bypassing the STB is as good as the digital anyway on most channels (not counting HD).


I would hate to give up all of this. Apart from being pi$$ed at DirectTV, once of the reasons I switched back to cable was to be able to do this.


- Tom

 

[UncD2000]

I couldn't agree more. Let's not push for changes that will do more harm than good for most cable subscribers. Eventually I think Davenir (see above) will be proved correct, however. Cable will become 100% QAM and finally deliver on the premature hype of digital cable, and will probably "blow satellite ... away with room to spare."

 

[UncD2000]



Originally posted by miatasm

It is possible to do what you ask but it would require a lot more bandwidth to become available. We would have to send channels 1-99 out twice. One in analog & again compressed and modulated in digital. It would take up waaaaay too much unnecassary bandwith.


rbaldwin, if you will check John Mason's post on this thread:
http://www.avsforum.com/avs-vb/showt...hreadid=199900

you will see that his TWC 860 MHz system is doing exactly what you asked about (and I estimated that his system still has room for high speed internet & local phone service, plus at least 34 HDTV channels).