When cable TV systems began 60+ years ago, all TV was analog and life was simple. Some people used set top boxes, but other people just plugged their cables directly into their TVs. At the advent of Internet access and digital TV, things got complicated. TWC has operated a hybrid network ever since. The analog part of the network carries the local broadcast stations and what I'll call the mainstays of cable such as CNN and ESPN. The digital part of the network carries Internet data ("Road Runner" as Time Warner once branded it), the HD signals of local broadcasters, the HD counterparts of the mainstays, and some new programming that was digital-only. In 2009 all local broadcasters went to digital over-the-air, but the cable companies converted those signals back to analog for subscribers who needed it. You could still get by without a set top box unless you wanted a premium channel like HBO. (Confession: I dislike set top boxes, and I really dislike paying for them.)
Now the analog mainstay channels on cable are being converted to digital slowly but steadily. Every cable system is doing so at a different pace; TWC in Raleigh will move C-SPAN, CMT, OWN, VH1 Classic, Discovery Fitness & Health, Lifetime Movie Network, TruTV, and Golf Channel to digital next month. In the process these channels become inaccessible to analog TVs without some kind of add-on equipment. Worse, encryption is gradually being added to almost all digital mainstay channels -- rendering them inaccessible to digital TVs that were marketed as "cable-ready", unless you get a set top box. I expect that in the near future, the only unencrypted channels on cable will be local broadcasters and C-SPAN. It's conceivable, although not a certainty, that analog versions of local broadcasters will be removed from cable too.
You might ask "What about CableCard?" Yes, a CableCard-equipped TV or video appliance can decode the encrypted signals that you've subscribed to, without requiring a set top box. But CableCard has run into a problem of its own: Switched Digital Video. SDV allows a cable company to carry even more channels. I'll skip the geeky details, but what you need to know is that a first-generation CableCard TV device cannot receive SDV. As usage of SDV increases, subscribers are finding that their old CableCard products can no longer receive all the channels that they once did.
Some pundits say that cable companies will make more use of SDV in the future; I tend to agree with them. Other pundits argue that usage of SDV will decline after cable companies have reclaimed all the analog channels. No one knows for certain, and the answers could differ from one cable system to another.
In response to SDV, there's a new generation of CableCard that allows TVs and appliances to communicate with an SDV adapter that the cable company installs. This combination allows a CableCard household to view everything that it's entitled to. Although you have to pay for CableCard, it's cheaper than a set top box. Also, the combination of CableCard and an SDV adapter provides flexibility such as streaming video to your laptop. Cable companies are lukewarm about this, at best; they prefer to profit from set top boxes and the services that require a set top box. But the FCC appears to be insistent on interoperability between SDV and CableCards.
- If you plug your cable directly into your TV, your selection of channels is about to diminish -- even in the so-called basic tier, and even if your TV is digital.
- If you use a first-generation CableCard product, your selection of channels will diminish too.
- Cable technology in the home is now on a short life-cycle. Budget and buy accordingly.