Plug and Play: Easy, Right? Ha!

If ever there were a phrase that sounded amazingly cheerful, given the anxious, high-stakes toil lurking just over its shoulder, it is the term "plug and play."

Plug and play. It sounds so "good to go." "Cash and carry." "You buy I'll fly." Do one simple thing — plug it in — and you're done. It plays.

Yet the "plug and pray" jibe, while admittedly tired, exists among engineers for a reason. If you've ever attempted to network all the gadgetry in your home or office geek-o-sphere, you know this prayer. (Usually it doesn't exactly sound like praying.)

The difference between "play" and "pray" is the chasm of code that makes the connectors and related software on one device attach to the connectors and related software on another device, so that both will work once they're hooked together.

In the context of this column, it is the plugs on consumer-electronics devices — ranging from digital TVs to digital video recorders — that will be made to play with digital cable set-tops that are built-in.

The trick is to do so to the satisfaction of everyone involved: consumers, consumer-electronics manufacturers, content owners and cable operators.

No digital input

In previous columns, we've discussed the odd fact that most digital TVs don't include a digital input. In a living room sense, the organic evolution of DTV means you can buy a digital TV receiver and a beauty of a high-definition display — but when you hook up your DVD player, you do so over an analog connector.

The reason there isn't a digital connector, in a general sense, is that there isn't agreement on which link provides the best armor.

Digital content is pure. It's not like analog video, which gets more and more grainy with each videotape that's made. The acute fear among content owners is "video Napsterization."

But the tide started to change on Dec. 19, when the National Cable & Telecommunications Association and the Consumer Electronics Association notified FCC chairman Michael Powell that they'd reached accord on how digital devices and digital set-tops should come together. The 78-page treaty also recommends methods to "copy protect" digital content.

And so it is that the discussion of digital interfaces — the plugs — necessarily includes a discussion about copy protection.

It takes two

As you begin the journey of understanding this warming phase between cable and consumer electronics, it's helpful to know that the plumbing discussions almost always come in twos: The name of the plug, and the name of the copy-protection method for that plug.

For example, you'll hear people talk about "IEEE 1394 firewire" in the same breath as "5C." Or, you'll hear something about "DVI with HDCP." Both are mentioned in the NCTA/CEA proposal to the FCC as "plug-and-play" necessities.

Translation: IEEE is shorthand for the Institute of Electrical and Electronics Engineers (it's spoken "eye triple E"). The IEEE wrote a technical specification, numbered 1394, for moving compressed digital video information over a connector. At the time, at 400 mbps, it was the fastest thing around, so it acquired the "firewire" descriptor.

"Five C," or "5Cs," stands for the five companies — Hitachi Ltd., Intel Corp., Matsushita Electric Industrial Co., Sony Corp. and Toshiba Corp. — that came up with a copy-protection scheme and encoding rules that work with the 1394 connector.

The 5C copy-protection plan works by applying encoding rules (too lengthy a discussion for this particular column) that dictate whether or not a show can be copied, and how many times that may occur. For example, brand-new content that's just headed for theaters might be tagged "copy never." For consumers who (eventually) own a recordable DVD player, and want to build up their DVD library, there's a provision for "copy once." And, there's a feature for "encrypt but don't copy protect," as well as "copy freely."

DVI comes in

Because the output of the 1394 connector is a compressed digital signal, it's great for transmission and copying, but not so great for high-definition graphics — which affects things like the electronic program guide.

A second digital interface, known as DVI (for "Digital Visual Interface"), is also recommended, with "high bandwidth digital copy protection" (HDCP). Speed-wise, DVI is more fiery than firewire, at around 5 gbps. It's fast enough for uncompressed HD digital video, and its speed also resolves the graphics issue.

The NCTA-CEA agreement doesn't address how to protect content that flows over the analog inputs of the 3 million or so digital and HD televisions already installed into homes. The thinking: Gotta start somewhere. Best to start in the direction of the momentum, which is clearly digital.

That's the early take on the "plug-and-play" buzz, as it relates to cable-ready digital TVs. If nothing else, it illustrates why technologists always disappear around the back of a technology display. They want to look at those plugs on the back panel.

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