Comcast begins digital transition in Chicago
By Ben Drawbaugh 
posted April 7th 2007 8:53AM
posted April 7th 2007 8:53AM
The digital transition has been officially here for some time and while there has been much debate how the cable companies would react to it, Comcast in Chicago has shared some of their plans. As previously predicted the Cable companies are going to use the analog shutoff to move their customers to digital and it is starting in Chicago. Starting in July, customers without a digital STB will only be able to receive local broadcast channels via cable. To help out Comcast will be providing one free STB to every customer, but charging additional fees, for additional boxes. This will open up the bandwidth for other digital services like HD and we expect that when those analog channels are cut off in 2009, that those remaining households will also go dark without a box. There is a chance that Comcast will continue to provide analog versions of the new digital channels, but we doubt it will happen. Considering that analog channels use the same bandwidth on cable as approximately 2 or 3 HD channels this can only be good news to HD fans.
Modern cable systems have 750MHz to 860MHz bandwidth. Every analog channel consumes 6MHz of bandwidth, so those systems support 125-143 channels, assuming you take away VOD and Internet. A cable system with 60 analog channels is using almost 50% of its capacity on just those channels.
With digital delivery (256QAM modulation), every SD channel takes the equivalent of 0.6MHz bandwidth -- one-tenth as much. A cable system with 60 digital channels is using less than 5% of its capacity.
With digital delivery (256QAM modulation), a 1920x1080i HD channel supplied with full ATSC bandwidth (i.e. maximum quality) will consume the equivalent of 3MHz, while a 720p60 HD channel will consume the equivalent of 2MHz. Full 1080p60 channels -- which don't exist yet outside of the lab -- consume up to 6MHz. At DirecTV's "HDTV Lite" quality levels, you can reduce that by 30-50%.
That's right, the 860MHz cable system in Chicago could offer 430+ 720p60 HDTV channels, 285+ 1080i HDTV channels, 143 1080p60 HDTV channels, or some mix of the three, at full quality...if they were to get rid of all other services. I believe Comcast Chicago is keeping ~20 local channels in analog on their system, so those numbers are reduced by about 15%.
In addition to providing superior efficiency, digital delivery also eliminates picture defects associated with analog transmission, such as excess picture noise, ghosting, and snow. Alll that extra bandwidth can be used for virtually an unlimited number of new SD channels, dozens of new full HDTV channels (none of that "HDTV Lite" crap), as well as HDTV VOD and faster Internet. Said a different way, digital delivery provides the consumer with improved service and more choice.
All this comes at the expense of a set-top box, which many cable companies now include (no extra cost) with a cable subscription. The rub is that some cable providers want you to pay for extra boxes for other TVs. I don't know if that is the case with Comcast Chicago. Ideally, a cable provider would include STBs to support a reasonable numbers of TVs in a household at no extra cost, and if they can't do that, at least decrypt the cable channels in the "digital basic" tier so they are receivable with the built-in digital cable (QAM) tuners found on virtually all new TVs.
In a year or two, this will be a moot point with new TVs. CableCard provides displays with the means to decrypt all cable channels, but most manufacturers don't incorporate it because of cost and usability concerns. Current CableCard implementations -- which use unidirectional OpenCable receivers -- cannot access guide information, interactive services, VOD, or channels delivered using Switched Digital Video (SDV) technology. That will all change next year.
Beginning in mid-2008, you will see televisions start to implement bidirectional digital tuners with OCAP in their TVs. With these TVs, you will simply plug the access card (CableCard) into the back of your display, and it will provide you full access to every channel and service you get with a set-top box. You will get the program guide with the same interface you get on the set-top box. By 2010, they probably won't even sell >$1000 TVs without this functionality.
bfdtv, thank you for this information. It really helped to clear up some questions I've had for quite some time. :)
>>> All this comes at the expense of a set-top box
Wow, this is interesting news, especially since I am in the Chicago area. Thanks to the first poster for a lot of very good information. My main concern with this upgrade, (which even I would say is necessary to keep pushing digital/HD content forward), is support for older TV's, having all these set-top boxes all over my house. The biggest challenge will be PC's with tuner cards and Windows Media Center. (I have MCE 2005 right now.) Will I still be able to access everything easily via the STB? Will this overall project basically force me to upgrade all the TV's in my house to have QAM, provided they do allow all the non-premium channels to be broadcast on QAM, as the first poster said?
Looks like I'll be calling Comcast to get more info.
Thanks Ben for the post. I read the article yesterday, but wasn't totally clear on what was going to happen to NTSC/ATSC tuner reception (or I guess transmission in this case).
As a chicagoan, the first question that comes to mind is "But it is good for MythTV?" I just got a PCHDTV-3000 PCI card in the mail and connected it with a $20 internal antenna from radioshack to see if I can get all of the HD channels that I am currently receiving from firewire. (It basically works, but I don't have the processing power/HD space to really test the HD feeds.)
Specifically, I wonder how I will record Comedy Central and Food Network? If I have to setup an IR transmitter to change the channel on my STB and encode from S-video, is it worthwhile even keeping cable at all; instead, watching The Daily Show/Colbert Report online for free and buying DVDs of Good Eats. I'm sure there's other things on cable I might want to watch, but if I cancel I won't know what I'm missing (unless its something like This American Life on Showtime which I wouldn't plan on recording on MythTV anyhow.)
In my part of Chicago there is no competition for Comcast, thus they have a $25 service which provides jack shit and a minimum of $51 to provide what I would consider to be basic cable. You have to spend something like $73 plus $7 for a HD cable box to get any HD programming that's not available over the air. At this point I'm just sick of comcast and its monopolistic power. Notice in the original article (which seems to have disappeared from chicagotribune.com) that Comcast didn't justify the transition by bringing up the terrestrial digital transition. Thus, the forecast for MythTV looks dim, despite what some lawmakers tried to do with their stipulation that cable providers provide firewire outputs. What we need is to stipulate that cable providers must offer all non-premium content over ATSC, without requiring a cablecard.
The FCC requires the cable companies to pass on the digital broadcast channels unecrypted, so you will be able to continue to record them with a MythTV or a 2005 MCE, provided you have a QAM tuner. Also any TV with a built in QAM tuner can also watch these channels without a STB or CableCARD.
But the FCC only requires the broadcast channels be unecrypted and in most areas, all the rest of the digital channels are encrypted, even though the analog equivalents are not. While this might make sense when the cable co charges extra for "digital" cable, when basic becomes digital we all hope this will change.
The only way to know what QAM channels are in the clear for sure is to do a channel scan and see what shows up, in some forums users share their results, so it may be worth looking into before you buy a QAM tuner, especially if you already have a ATSC tuner and can't get any channels in addition to what you already get OTA.
as a Tivo user I see "more choice" as locked in DRM content without freedom to do with as I want. Comcast decision is to limit choice by consumer and open up more revenue streams. . .
From a similar Chicago Sun-Times article:
http://www.suntimes.com/business/330445,CST-FIN-cable06.article
Schaefer said setting up the new cable boxes is simple, just switching three to six wires.
"It can be done in a couple minutes," he said. "They don't even have to set up the clock. The satellite will do that for them."
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So Comcast is trying to make the transition understandable by telling people that your time will be set by a satellite? Is this even true? Don't they have time servers at their distribution points? As someone who isn't intimately acquainted with the cable distribution system this is just confusing.
I just hope they get smart and move all the channels currently available as analog to clear QAM. At least the customers with ATSC/QAM tuners in their HD and SD tvs can still watch basic cable.
In Seattle, they are trying to encourage people to get digital cable boxes for their TV's. They will ship you up to two additional boxes that you can use in your home for free for 1 year, then you have to pay the regular rental price. This is probably to make it easier on them when it's time to make the switch over to all digital.
quote "All this comes at the expense of a set-top box"
I'm surprised that there isn't more objection to this. In addition to 2 HD capable recievers, I have 5 analog TVs (4 and a PC based card) which happily receive 'basic' cable (locals + CNN etc.). I would like to replace all of them with QAM capable equivalents.
However, since they are in locations where I can't or don't want to use a cable box, if I replace them - they are all restricted to 'limited' cable - even though I am a 'premium' account and pay for 'digital' and all the movie channels.
So, my options are now:
1. Pay more money & use a cable box - which I don't want.
2. Wait several years for Cable Card or OCAP capable sets to reach current price points.
Well, if a set top box is required, Comcast has now provided other alternatives. Fios is in my area and there are satellites overhead....
I too live in Chicago and have a Mythtv. I recieved a letter from Comcast yesterday informing me that as of May 1, all of the analog channels besides the localy broadcasted will be turned off. I am trying to figure out exactly how this will affect my Mythtv. I figure that my 2 choices are to use an IR blaster to control a Comcast STB or replace my Hauppauge PVR-250 analog cable card with something digital. I hope to find more information on what channels can be decoded with a QAM card.