Sessions Matter More Than Thick and Thin


The Halloween candy isn't gone yet, the Thanksgiving feast is showing up on the bathroom scale and we're headlong into the high-caloric holidays-which brings to mind the ongoing talk about "thick" vs. "thin" clients.

First, some basics. When people say "thin client" or "thick client," they're talking about the digital set-top box. This is "client" as in "client-server."

Second, thick versus thin has less to do with physical size than it does with capabilities, or how much processing power, graphics capability and memory resources are available.

Third, "thin versus thick" is really a supplier-inspired way of delineating "now versus next." Thin is now. Thick is next. Because time is relative, what's thick today is thin tomorrow and what's thin today was thick yesterday.

In today's environment, "thin" correlates to Motorola Broadband Communications Sector's "DCT-2000" line, and Scientific-Atlanta Inc.'s "Explorer 2000" line (including all clones). "Thick" describes both manufacturers' more advanced boxes: Motorola's "DCT-5000," and S-A's "6000/8000" series.

Fourth, there will always be the thick and the thin. Six of cable's top-seven operators (Cablevision Systems Corp. excepted) operate services on "thin" boxes to an aggregate 6.8 million U.S. households, as of Sept. 30. They're installing "thin" units at a combined rate of about 114,000 per week.

Always seeking metaphor, I offer this: "Thick versus thin" is like Americans. Generation by generation, we get taller and heavier. Photographs of ancestors show smaller, shorter people; your grandmother's china hardly seems big enough to hold today's ample servings. You order a cup of coffee in another country and embarrass yourself with your surprise at its thimble-like capacity (at which point you know for sure that you are an American).

Ditto for set-tops. Motorola's DCT-1000 was gigantic compared to the various analog units that constituted the set-top landscape in 1995. Those very boxes, now grandfathers to the beefier DCT-5000, seem tiny by functional comparison. And yet, some already view the DCT-5000 as emaciated.

Somehow, we've all gotten wrapped up in the debate, while avoiding the steeper slope. Thick versus thin is an issue, but it is not the
issue. Client-server is the issue. That's the new part, and the challenge. It is the sessions between the box and the server that matter, because "thin' is a given.

Think of the "now": the 6.8 million digital boxes deployed by AT&T Broadband, Adelphia Communications, Charter Communications, Comcast Corp., Cox Communications Inc. and Time Warner Cable. They present more channels and a navigational aid.

The channels are compressed with the Moving Picture Expert Group's MPEG-2 standard, imprinted into a quadrature amplitude modulation (QAM) transmission path, broadcast to the box, decompressed and presented to the TV. The guide, in most cases, is a permanent resident in the box. No client-server activities exist, for the most part.

People who say they run on the "now" usually mean they've devised a way to make the box do sessions with their software, which is located elsewhere. Some call this a "virtual channel" environment.

In some cases (think WorldGate Communications Inc., or Ron Pitcock's new venture, Integra5), this means they've made their application behave as though it's an MPEG-2 video channel.

In other cases (think all middleware providers), a built-to-fit software module sits in the box, acting as both interactive storefront and traffic cop to various, remote interactive applications.

The "next" will be video-on-demand (VOD), cable's first major push into session-based interactions. VOD will pave the way for other types of interactive sessions, many of which will be tested throughout the U.S. and Canada next year.

The name of the game is, and will be, establishing how many simultaneous interactive sessions a box can handle. Executives with Scientific-Atlanta visited recently to describe a chart they'd developed using deployed digital set-top numbers.

A blue line shot straight up, starting in March (not coincidentally, that's when Time Warner turned on the digital set-top spigot). Under it was a flatter green line, depicting the number of deployed boxes capable of handling multiple, simultaneous interactive applications. The implication: The green line is about to fork wildly up, in lockstep with the blue line.

Yet a few months back I spoke with a cable engineer who expressed great glee at getting both Wink Communications Inc. and WorldGate to run on a single digital set-top box of the thin variety. This is where we are: two. If it's true that you can never be too thin, then it's a matter of adding more without exhausting the very resources that make you skinny.

Until the thick boxes start rolling in, it's probably wise to examine what you can do with what you already have. Tally up the resources under the hood of the boxes you've already got. Compare it to the services you want to launch. Think sessions. You already are thin, with thick on the way. And once you're thick, you're too thin for the next stuff. If only this worked anatomically.

Stumped by jargon? Send your translation request to Mark it "Translation Please."