One of the new “features” that you may have heard about on HDTV sets is a CableCARD slot. While a TV equipped CableCARD slot does offer some advantages over a TV without this type of slot, it may not be something that you really need or want with your new HDTV set. This article is intended to provide an explanation of what a CableCARD offers, how it works and to help you decide whether or not you need one with your new HDTV.

A CableCARD is a small card designed to replace the bulky set-top cable boxes that cable and satellite providers use. Like a cable box, it is designed to decode encrypted digital cable signals so that you're able to watch these channels on your TV. Cable and satellite providers will often charge a monthly fee for a CableCARD. The reason cable and satellite companies use set-top boxes and CableCARDs is to keep people from stealing their services. The digital TV signals are encrypted before they are sent to your home, and the set-top box or CableCARD decrypts the signal so that it can be displayed on your TV. So, in essence, the purpose of the CableCARD is exactly the same as a set-top box.

Let me first just say that if you are only interested in finding out whether or not you need a CableCARD, you can skip this section entirely. ;-)

As I mentioned, a CableCARD performs the same function as a set-top box. However, the decryption process when using a CableCARD is more complicated. Once the CableCARD receives the encrypted digital signal from your cable or satellite provider, there are three additional steps required before the video is displayed on your TV:

1) Decryption – The CableCARD receives encrypted digital programming information and decrypts it.

2) Re-encryption – The CableCARD then encrypts the decoded information again, and passes it on to the TV along with a decryption key.

3) Decryption – The TV receives the re-encrypted information and uses the decryption key to decrypt it.

Re-encryption is one way that cable providers prevent their services from being stolen. In order for the CableCARD to pass on the decryption key to your TV, it has to be activated by your cable or satellite provider. Activation is what tells the CableCARD that you've a legitimate customer and it is OK for you to be watching the channels that you subscribe to.

First, let's weigh the pro's and con's of having a CableCARD slot in your new HDTV:

- Smaller size and less obtrusive than a set-top box

- CableCARD's are capable of one-way communication only – meaning that video-on-demand and pay-per-view services are not available if you use a CableCARD. This is important to note if you enjoy the convenience of ordering movies through your cable or satellite provider through an “on demand” service, as these services are not available if you use a CableCARD. It is also important if you like the interactive program guide that allows you to select a particular movie or TV show and see the details about which actors / actresses are in the show, what year it was made in, etc.

- Some cable and satellite providers charge extra monthly fees for use of CableCARDs

- Some cable and satellite providers charge extra for the installation (especially if you are replacing a current set-top box with a CableCARD)

So, the bottom line is that a CableCARD does not provide any real benefit to the average consumer looking for a new HDTV. It is not going to provide any improvement in picture quality or sound quality and will not help you save money over using a set-top box. If you are planning to hang a plasma or LCD HDTV on a wall and don't want a set-top box to be visible at all, a CableCARD equipped HDTV may make sense for you. If you are very limited in terms of the available space for the components connected to your HDTV, you may value the idea of using a small, credit card-sized CableCARD instead of a larger set-top box.