ITV: Your new best friend?

Tue, 10/31/2000 - 7:00pm
Leslie Ellis, Technology Analyst

It used to be that interactive TV was the gently swirling eddy, minding its own business in the wide wake of broadcast digital TV.

And what a wake it's been. Throughout the first half of this year, cable's top operators logged an average of 125,000 new digital customers weekly, for a grand total of more than 5.5 million. DBS isn't far behind on digital hookups, adding about 65,000 new customers weekly. Its two heavyweights, DirecTV and EchoStar, remain in front with total digital video subscribership: Nearly 13 million subscribers (combined) as of the end of June.

But ITV's eddy will soon spin into a vortex of its own. Propelled by competition and an advancement of increasingly muscular digital set-tops, ITV technology starts spinning its own centrifugal forces next year.

With it will come yet another whole new lexicon that cable technical personnel will need to learn, and a whole new set of technologies to understand. For those who are already saddled with the tasks of making digital video, high-speed data, and telephony happen—while continuing to nurture core analog TV services—we're guessing you barely have time to read your mail, let alone linger over the software realities headed your way with ITV. If that's the case, this is for you.

There are seven things you need to know about what's coming in interactive TV technology.

1. It really is coming. Think of it this way: There have been at least three Moore's Law turnovers in digital and interactive TV technology since the last ITV heyday. That alone means the boxes headed into the field today are suitably outfitted to be more than mere channel expanders. And, the boxes entering the pipeline next year are even more plush. Not using built-in (and expensive) technological capabilities is like buying a Swiss army knife because you need a toothpick.

The reason why ITV didn't happen so many times in the past is simple: The timing wasn't right. Technologies were too expensive. Competition was in a mutual retreat: Telcos backed away from video, and cable backed away from telephony. The use of cable's broadband pipes for high-speed access to the Internet became a huge (and, in hindsight, wisely lucrative) distraction.

Now, the time is right. (Or at least, more right than it's been so far.) Not only is the hardware strong enough, there's also competition. Both DirecTV and EchoStar are racing toward ITV launches next month, ranging from personal video recorders (PVRs) to AOLTV.

2. It's going to be complicated. The set-tops headed your way include 300+ MIPs processors; between 10–50 Megabytes of total memory; multiple tuners; 3D graphics chips; and a DOCSIS 1.0 modem (in some cases). Some will have interfaces for hard disks, for on-demand viewing. Others will have a receptacle slot for a removable security card, or a money card, or both. Contrast that with the big decision point of 1996, when operators were wrestling over whether to add an extra megabyte of costly RAM—for a total of 2 Mbytes—to decode the b-frame of the MPEG-2 signal.

And that's just the underlying hardware components. Also coming is a hierarchy of software, much of it brand-new to cable.

At the bottom of the pile of software is the real-time operating system—the code that talks "to the metal" (chips). Above that is the operating system. Chances are you'll be using one of two flavors: Scientific-Atlanta's PowerTV or Microsoft's Windows CE. On top of the OS is, potentially, the third block in the hierarchy: "Middleware." This stuff comes from companies like Liberate, OpenTV, Canal+, WorldGate and others. Not only does each layer need to work perfectly in isolation, it also needs to sync perfectly with every other layer. That's no small task, as AT&T Broadband, Motorola, Microsoft and others learned the hard way this summer.

The good news is, most things are complicated at the beginning. Recall the angst of the industry's two biggest set-top suppliers, Motorola and Scientific-Atlanta, to get the first batches of digital set-tops to market. The enormity of the task was almost daunting. But that's what technologists are good at: Complexity.

3. Software is the name of the new ITV game. Very few ITV applications will be permanently resident on the advanced set-top box. Instead, the applications will almost certainly be housed in a headend server, and meted out to interacting homes over a middleware layer of set-top software. That means another batch of devices requiring passage in the 5–40 MHz upstream signal path, more servers to maintain, more software downloads. If you haven't already started recruiting for software gurus, start. You'll need people who, at the very least, know scripting languages, client-server configurations, and version control. Better yet is someone who knows all of that, plus RF, MPEG-2 and DOCSIS technologies, and the C programming language.

4. There will be a formal industry process. You're not totally on your own. In September, CableLabs formalized what's been the most technically and politically challenging aspect of the OpenCable specification suite: Middleware. Calling it the "OpenCable Application Platform," CableLabs selected vendor authors and established a year-end 2000 deadline for the layer of software that sits between a set-top's operating system, and actual ITV applications. OCAP disallows ceding too much content development and systems control to one software supplier, by splitting the project into two segments.

One segment is an "executable engine," used by applications developers to write and test things for TV—like clickable ads, instant messaging, player stats and contests. Sun Microsystems Inc. will write the specification for ITV executable engines; its "JavaTV" is the CableLabs-licensed cornerstone of the project. The aim is to accommodate ITV applications that are self-contained, secure and capable of complex activities, like merchandise transactions.

OCAP's second piece is a "presentation engine," which uses HyperText Markup Language (HTML) to map interactive applications (the executables) onto the TV screen. Microsoft and Liberate will write it. Presentation differs significantly from execution. To present interactive content on the TV, using techniques like HTML and ECMAScript (formerly JavaScript), it isn't generally necessary to use a full software program. Adding executables into HTML requires extensions, also known as plug-ins. Unpredictably sized and numerous, plug-ins are difficult to manage in a set-top environment.

In addition, CableLabs identified Canal+, OpenTV and PowerTV as contributors to the effort, meaning they'll write and sanity-check the work done by Liberate, Microsoft and Sun.

5. "Trigger happy" will take on a whole new meaning. In some ITV environments, like that described by the Advanced TV Forum (formerly "ATVEF"), the center of the ITV action is a thing called a "trigger." It's little more than an Internet URL (Universal Resource Locator) address, transparent to the viewer, that gets transmitted in one of three ways: The vertical blanking interval (VBI), or the in- or out-of-band signal path. Client software on the set-top sees the trigger, and places the icon for it on the TV screen. Maybe it's a player stat. The subscriber clicks on it. The request zings up through the reverse plant to the headend, where a server locates the Web page—usually pre-formatted for TV. The process repeats itself as the viewer interacts.

6. Bug lists will become part of your vendor discussions. In the brave new world, it's wise and advisable to ask ITV suppliers about known bugs. All software providers have these lists: They're a normal and expected part of the to-do process in building software products. Whether you're just beginning ITV application evaluations, or somewhere else in the process of queuing up, ask about bugs. Be wary of anything that sounds too good to be true ("Bugs? No bugs here."). Be wary of any bug alleviated only by set-top rebooting. Get a list of when the top-10 bugs will be resolved, and how that will affect your customers.

7. Version control will give you nightmares if you don't organize it now. Start thinking now about how to manage what will assuredly be a dizzying number of patches and different versions of software populating the field. One system may experience a location-specific bug, for example. You need a patch from your software supplier to fix it. That one system is now different from the rest. This matters when the time comes for the next upgrade. In most cases, suppliers will maintain version control—but some MSOs are already developing their own methods, to be doubly sure.

As in all things, the more you know, the better. Understanding not only ITV technology, but its place in bundled cable services is smart, because it's invaluable to your career as a technologist.



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