A Closer Look at 'XHT’ From Charter, Samsung

Every once in a while, even though there’s a press release and a signing ceremony, something momentous goes mostly unnoticed. Like the one about the little gizmo that makes (some) one-way digital TVs into two-way DTVs.

That gizmo is called an “XHT,” for “expandable home theater.” It’s the handiwork of Samsung Electronics America Inc., which will hone it with Charter Communications Inc. The two announced their pact at last month’s Consumer Electronics Show, saying it would help drive sales of both HDTV sets and high-def services.

Realistically, though, it’s more than that. On an industrial scale, this is a fresh volley in the old battle about what’s at the center of the universe at home — the TV or the PC.

Samsung is banking on the latter. It views its XHT idea as the way to make your entertainment gear as peripheral to your TV as your printer is to your PC. It’s home networking for your video stuff, with the television as the center of the universe — but using tools developed for the larger Internet.

Like walkie-talkies, having just one XHT thing doesn’t do you much good. Instead, XHT fits inside DTVs and in the aforementioned, low-cost, unobtrusive plug-in gizmo. It also could go into other digital stuff, like DVD players, cameras and anything else that could be enhanced with a connection to the TV.


The gizmo that plugs into the back of a digital TV and, presto chango, makes it a two-way set, goes by the working name “NIU,” for “network interface unit.” It’s one in a family of XHT devices. It contains a CableCARD slot, a DOCSIS (Data Over Cable Service Interface Specification) Set-top Gateway, or “DSG” (mostly cable-modem software), a little Web server and FireWire.

So, in a nutshell, the NIU is digital cable in, FireWire out, DSG up.

The companion digital TV with XHT also has FireWire, and a little Web browser. The browser is built to query any of the little Web servers connected to it over FireWire — the NIU, the hard drive of the DVR, a DVD player or whatever else.

Here’s an important thing to remember: All this mention of Web browsers and Web servers doesn’t mean those devices are built to surf the Internet. More, it’s a matter of technological convenience — reapplying common techniques of a really big network (the Internet) to manage much smaller networks, like in people’s homes.


As you might have noticed by now, a big part of XHT is FireWire. It has a synonym — “IEEE-1394” (the Institute of Electrical and Electronics Engineers set the standard) — which tech people use interchangeably with FireWire to describe a super-fast (400 Mbps) way of interconnecting peripherals.

“Peripherals,” in an entertainment-center sense, could be other HDTV sets, DVD players, DVRs or your new digital camera.

The people who like FireWire like it for several reasons. They like the 400 Mbps, naturally. That kind of speed means more compressed HD channels can move around. They like that stuff connected by FireWire can discover other stuff connected by FireWire, without help from a PC and its operating system. And they like that FireWire plays nicely with digital rights management (DRM).

All in, Charter sees Samsung’s XHT as a sort of “on-ramp to two-way,” ready for action as early as this summer.

How does XHT affect the larger, more complicated work on two-way plug and play devices? It’s a parallel effort, involved technologists say. Translation: XHT doesn’t need OCAP (OpenCable Applications Platform) to begin, but will support it when it’s time.


In terms of how XHT plays out in consumer situations, consider Customer Bob, who wants an HDTV set. Let’s say he buys a Samsung model and he lives in a Charter town. Marketing plans aren’t out yet, but it’s plausible to imagine Bob ordering HDTV service that comes with that NIU that plugs into the back of the set.

Then what? Or, as one engineer said, after mulling the Charter/Samsung project: “Two-way to what?”

Remember the little Web server in the NIU? If Bob does anything that requires a two-way connection, the little Web server burrows out over the DSG to a headend server, on behalf of the Web browser in the TV. Again.

This isn’t “Web surfing,” per se, but using the techniques of the Web to accomplish a similar-but-different mission.

And yes: That does mean Charter needs to build a Web-ish front end for any services Bob and his ilk want to see — be it a (Charter-branded) guide or an on-demand title.

As to-do lists go, that’s fairly big. Also tricky is Samsung’s solitude, so far, in building devices that include XHT. Until other CE manufacturers join in, only Samsung’s one-way TVs and digital entertainment peripherals can be made two-way.


Still, Samsung’s XHT is built on an open standard — CEA 2027, which Samsung wrote. (“CEA” stands for “Consumer Electronics Association.”) CEA 2027 references other open methods to accomplish its work. There doesn’t appear to be any proprietary goo lurking in the background.

Clearly, CEA-2027 and Samsung’s XHT will carry a lot more oomph if and when other CE manufacturers jump in with their own versions (and they work).

But if interconnecting our entertainment stuff remains nightmarish, relative to the “plug-and-play” world of the PC, everybody who makes entertainment stuff is disadvantaged. That makes XHT another example of “ya gotta start somewhere.”

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