TV Signal and Your PC – A Supplement to BYOB Podcast #13

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Switched Digital Video

Cable companies originally had analog signal going through the cables that provide you signal. As I mentioned earlier, once digital happened, now cable companies could send more channels and more information to you. So what needed to be changed? Bandwidth. You can only fit so much information or data in a cable. Originally, cable companies would send all of their channels, all of the time, to all of the subscribers.

Now if you think about it, why send every friggin’ channel to a house when the people inside are watching only one or two channels? In fact why send CSPAN to every house when no one watches it, right? It is a waste of bandwidth. The major cable companies have decided to send only the channels you are watching to your house. It varies by market but eventually they will all migrate to this new system. If you are on a Switched Digital Video (SDV) system, whenever you change the channel a signal from your set top box is sent to a local “node” (probably within a mile or so of your house that serves a couple thousand homes) and that node “switches in” that channel for you. This makes more sense and frees up bandwidth. Think of it is as similar to On Demand technology. Now, here is the part of SDV that affects you.

Modern cable boxes communicate back and forth all of the time with the node. It happens instantly, and seamlessly, within the closed cable equipment system. As I mentioned, any digitally encrypted channels are “switched out” when not being watched so when you want to change channels, and watch a show like Discovery Channel, your cable box sends a signal to the node and you are now almost instantly watching Deadliest Catch. Everything works great. Well…

Note: SDV is good for the average consumer since it frees up bandwidth and allows the cable companies to offer more services. It is just not good for those of us with CableCARD devices!

What about external networked TV tuners or ones inside your computer? Well this is where it sucks for us. Since the SDV channels are encrypted, the TV Tuner connected to your computer sees that channel as one it cannot access due to encryption or scrambling. No watchie for you. How do we deal with this?

Tuning Adapters

If you have SDV, you need a device to communicate with the node. A Tuning Adapter is the device you must use. A Tuning Adapter sends the node the signal of the channel you want to watch. The set top box does this automatically are part of the cable equipment but we need this since our equipment does not function exactly like a cable box.

Those of you with TiVo’s in SDV areas have that second box on top of your TiVo that communicates with the node. The Tuning Adapter allows access to all of the encrypted channels that are available to you in your cable package. Tuning adapters typically support two tuners each so those of you in a SDV area will require at least one, if not two for the latest CableCARD tuners.

CableCARD devices, including TiVo, Ceton InfiniTV and the new SiliconDust HDHomeRun Prime, do not currently support SDV without the use of these Tuning Adapters.

Now what is the CableCARD thing I just mentioned?

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CableCARD™

In the beginning, the only way you could get a premium cable signal to your TV was through the set top box. Sure, you could plug the cable directly to your 19” Zenith, but you would only get some of the channels and not the really good stuff. You needed a set top box, or as Andrew Edney would say, a “digibox”.

Well in 1998, the FCC told the cable companies they needed to give the consumer a way to get this multichannel premium signal without proprietary cable equipment. In 1999, the TiVo was born and by 2000, the CableCARD was available to subscribers. Well it was available if you could get the cable tech person on the phone to acknowledge they existed. Moreover, equipment to use the CableCARD in. Anyway…so here we are in 2010.

Now CableCARD can be its own article, but just understand for this post these four things about CableCARD:

• CableCARD is not required for non-scrambled cable channels
• The card acts like a” key” to unlock the channels that you subscribe to
• Your CableCARD is matched between you and your cable company so it MUST come from your provider and usually requires a truck roll
• Your device must be made specifically for CableCARD for it to work

You can find out more on CableCARD at:

http://www.cablelabs.com/opencable/primer/cablecard_primer.html

Again, CableCARD is too large a topic for thisarticle so let us know in the comments if you want more information on CableCARD.

Lastly, a recent but segmented signal type…

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Verizon FIOS and AT&T U-Verse

In 82 words or less, the fiber signal goes from the Verizon office to a node; the node serves up to 32 houses and then comes into your house. A terminal then transfers the data to the hard wiring in your home. You can get TV, Internet and phone. At this time these two companies are not really developing more infrastructure and are concentrating on wireless so you probably will not it expanding anywhere else than it already is any time soon.