Archives

January 2001 Issue

OpenCable Completes Busy Y2K
Makes Progress on Set-Tops, Plans for Interactivity
By CableLabs Staff

OpenCable, the CableLabs program to define interface specifications for advanced digital set-top boxes and manage the process of interoperability testing, completed several key deliverables in 2000. It’s poised to tackle a variety of interactive television advancements in 2001.

The early months of 2000 were an all-out sprint to meet the July 2000 deadline mandated by the Federal Communications Commission to complete a method for removable security in digital set-tops. Known in technical circles as "J2K," the goal was to make cable set-tops that could be sold on retail shelves. It necessitated set-tops built with a receptacle slot for a point of deployment module, or POD. The POD contains signal decryption and conditional access elements, which until then had been intrinsically designed into the box.

The FCC’s vision was for a consumer to walk into an electronics store, buy a cable set-top, then contact the local cable provider for a POD card when purchasing premium, scrambled services such as HBO or Showtime.

To meet the challenge, CableLabs hosted several interoperability tests throughout 1999 and the early months of 2000 to ensure that set-top devices were able to decode premium services via the POD module. OpenCable met the July 2000 deadline with little fanfare.

Also last year, OpenCable finalized its network interface specifications, and sent them to the Digital Video Subcommittee of the Society of Cable Telecommunications Engineers to standardize as "DVS313."

Further validation of cable’s insistence on interoperable set-tops proved itself in 2000 via purchase orders from cable operators for OpenCable-compliant equipment. AT&T Broadband, for example, placed orders throughout the summer with Motorola Broadband Communications, Philips Electronics and Matsushita Electric Corp. of America (Panasonic). In each case, the AT&T units will contain a slot for an OpenCable-based removable security card, or POD.

More support from cable operators for OpenCable-based set-tops is anticipated in the near future. And, cooperation is solid from the consumer electronics side, as well. In late September, a CableLabs hardware forum focused on OpenCable set-tops attracted more than 70 different companies—a 50 percent increase in attendance compared with a similar conference held in April 2000.

Software focus

Having met its deadline for removable security modules, OpenCable went on to tackle advanced set-top software. In 2001, it will continue to work on its OpenCable Applications Platform (OCAP) specification for interactive television applications and interfaces. OpenCable named its middleware environment "OCAP" mostly to sidestep the mixed, and, therefore, confusing, industry definitions of "middleware."

OCAP separated the set-top software environment into two pieces, and accepted vendor authors for each to develop written specifications by year-end 2000.

The first piece is an "execution engine," which will be written by Sun Microsystems. The second piece is a "presentation engine," to be co-written by Microsoft and Liberate Technologies. Three other interactive television suppliers—Canal+ U.S. Technologies, OpenTV and PowerTV—also were selected to participate in writing and critiquing the two specifications.

How OCAP works

The execution engine will include Sun’s JavaTV programming environment, which CableLabs will license. This is how it works: Programmers develop an interactive application written to the OCAP specification, in Java. When the cable customer, outfitted with an OpenCable-compliant set-top, accesses the application by clicking on the icon that represents it, the application is downloaded (transparently) into the box. A Java engine resident in the set-top sees the incoming application, unfolds it and runs it.

The "presentation engine" is a hyper text mark-up language (HTML)-based method that tells the set-top where to display an Internet-based interactive application on the TV screen.

The presentation engine necessarily corresponds with the Advanced Television Enhancement Forum (ATVEF) specification, which sends an interactive "trigger" in the vertical blanking interval, or in the in-band or out-of-band signal path. The "trigger" is usually a Web URL (uniform resource locator), transparent to the end customer, and displayed via an icon on the screen.

When a subscriber clicks on the HTML-delivered icon, a session is established between that set-top and a headend server to "fetch" the requested content. Say, for example, the trigger delivers an icon offering $10 discount off a ski lift ticket. The cable customer clicks. That request is sent upstream to a server, which "fetches" more information about the coupon, including the subscriber’s mailing info. The process repeats itself to fill out the form and transmit it.

Write once, run anywhere

The advantages of OCAP and its two layers accrue to cable customers, software developers and cable operators. For programmers, it means a content authoring environment that is "write once, run anywhere." For cable operators, the specification assures parity among interactive TV suppliers, so that no one operating system or middleware vendor gains control over the interactive authoring environment. For cable subscribers, OCAP, while transparent to their usage, assures a wide range of interactive applications, both HTML- and applet (Java)- based.

The OCAP spec will transform further the advanced digital set-tops heading into the cable sector. Not only will those OpenCable-compliant devices contain a receptacle slot for a POD, they also will contain both a Java and an HTML engine, so as to handle the executable and presentation portions of the OCAP spec.

Pending the finalization of the two OCAP software specifications, due at the end of December (before presstime), CableLabs will proceed into interoperability tests—much like it does with cable modems and the Data Over Cable Service Interface Specification (DOCSIS).

Tackling encryption

During 2001, CableLabs also will work to conclude inter-industry negotiations between content owners, cable operators, OpenCable vendors and consumer electronics manufacturers to finalize the complex licensing requirements for the dynamic feedback arrangement scrambling technique (DFAST) algorithm.

DFAST outlines a proprietary key exchange method to encrypt communications between the security card and the OpenCable device. Content creators have asked that all such communications be encrypted as a way to prevent unauthorized digital program duplications. The cable industry has selected DFAST for the encryption method.

The FCC, in September 2000, issued a Further Notice of Proposed Rulemaking on navigational devices, such as set-top boxes. Specifically, the FCC concluded "that some measure of anti-copying encryption technology located within a host navigation device is consistent with the commission’s navigation device rules."

In November, CableLabs submitted to the FCC its final version of the DFAST license to enable deployment of OpenCable-compliant set-tops. Copy protection more generally will continue to be the subject of negotiations for future products.

CableLabs will continue to work on OCAP and encryption throughout this year.

You may reach CableLabs at or www.cablelabs.com.

 Back to January 2001 Issue

Access Intelligence's CABLE GROUP
Communications Technology | CableFAX Daily | CableFAX's CableWORLD | CT's Pipeline
CableFAX Magazine | CableFAX databriefs | Broadband Leaders Retreat | CableFAX Leaders Retreat