Greetings. If you pay for digital cable television tiers, is the service as "digital" as it's supposed to be? Don't be too sure. As it turns out, cable companies can easily cut corners and "cheat" on some aspects of digital tiers in many cases, and you may be none the wiser -- but still negatively affected.
I'm not talking about the perennial controversies regarding the bandwidth cable companies provide on digital channels, vs. audio and video quality -- that's a story unto itself. Rather, let's talk about how you may be paying for digital channels and actually be receiving analog ones instead.
While there is an increasing trend toward all-digital systems, most cable companies these days still provide a mix of analog and digital channels. For example, a typical channel layout may have analog transmissions from channels 2-99, containing local broadcasts and "basic" cable channels like CNN, History Channel, C-SPAN, and the like. These are all channels that can be received without a cable company "converter" box (these days they are usually far more than simple converters), e.g. by "cable-ready" televisions.
Most other channels are in digital tiers, and require either a cable company box, or a third-party device like a TiVo HD, with installed cableCARDs, to handle available digital channels. (As I've reported previously, "switched video" systems may even prevent cableCARDs from viewing some channels.)
Frequently, some or all of the analog basic cable channels are simulcast in higher quality on digital tiers -- sometimes on completely different channel numbers, other times via "mapping" of digital channels onto what would otherwise be channels numbers in the analog tier under, say, channel 100. In the latter case, a digital subscriber tuning to channel 2 would get the digital version of broadcast channel 2, while an analog subscriber would get the analog rendition of broadcast 2.
In general, most cable companies want you to use their boxes (which of course you have to pay for by the month) rather than third-party equipment like TiVos with cableCARDs (even though you still must usually pay the cable company each month for the cableCARDs).
As implied above, just as cable companies can control the particular channels that you receive, a key aspect of modern digital cable system boxes and cableCARDs is that they have the capability to arbitrarily map channel numbers. That is, you may be tuned to channel 100, but actually be receiving a completely different channel. In fact, it's often possible for different subscribers or various classes of subscribers to have completely different mappings, depending on the particular technology in use.
So a cable firm can decide, for example, that users of their own boxes will get particular channels in digital, and they can also declare that third-party cableCARD device owners receive a completely different lineup of enabled analog and digital channels.
Now we get to the fun part. How can you tell if a channel that you're paying for as part of a digital tier is actually being delivered to you as an analog channel instead, and should you care?
Answering the latter question first, of course you should care! You're paying for digital, you should get digital. Outside of the lower video and audio quality that can be present on many analog feeds, third-party devices (like cableCARD TiVos) which could otherwise record a digital signal directly, will be forced to re-digitize an analog signal, with inevitable quality loss in the process.
But how to know for sure if a channel is digital or analog as received? Without access to the diagnostic pages of cable company boxes, this can be tough. However, some third-party devices will reveal the truth very quickly. I've heard examples of these situations from various areas, but here's a case that I'm dealing with myself right now.
The TiVo HD has easily accessible diagnostic modes which clearly spill all the beans relating to these issues. Here in the West Valley (Los Angeles) system of Time Warner Cable, I can clearly see that, at the moment, virtually all basic cable channels in the digital tiers that have simulcast analog (under channel 100) equivalents, are actually being delivered as analog channels, at least to my cableCARDs.
Example: When I tune to History Channel on channel 212 in a digital tier, the main channel displays all do say 212, but diagnostics tell me that I'm actually tuned to analog channel 39 -- the analog version of History Channel -- explaining the lower quality image and resulting recording issues on the TiVo. This is in fact the case for essentially the entire set of channels that exist in both digital and analog tiers on this system right now.
On the other hand, if I tune to channel 213 (History International) which exists only in a digital tier, it is received in digital form, naturally enough.
Why are so many channels being paid for as digital actually being received as analog? Cable company representatives of course attempt to blame the TiVo or the cableCARDs (they hate dealing with either), but the kind of deterministic channel mapping that is occurring cannot be the result of a failure or breakdown at subscriber equipment -- it has to be programmed that way via the cable company headend.
And whether this situation is the result of purposeful planning or cable company confusion isn't really terribly interesting either. If you're unable to get anyone in authority to admit that such channel switcheroos are going on, and can't get them resolved, you're simply not getting what you're paying for, and (to quote "Plan 9 From Outer Space"): "Somebody's responsible!"
So if it seems like your digital channels just aren't up to snuff, or your TiVo is treating digital channels as if they were analog -- well, you may actually be a victim of a cable company channel shell game, and you might want to let your cable company (and perhaps the FCC if your cable firm plays hard to get) know exactly how you feel about it.
When so-called digital channels are really analog, you're being cheated, plain and simple.