Decoder interface expected to fuse cable, TV function

Electronic News, April 4, 1994 by Reinhardt Krause

WASHINGTON--The Electronic Industries Association and cable TV industry have co-developed a decoder interface that is part of a new "cable-ready" TV definition which the Federal Communications Commission could announce as early as this week. The decoder interface, in effect, would provide TV receivers with much of the same functionality that has been in analog -based addressable cable converters as well as what would be available in nest-generation digital terminals.

The Cable-Consumer Electronics Compatibility Advisor Group has also recommended that the FCC, through the new decoder interface, address lingering standards issues as high-definition TV and interactive networks are deployed by cable operators and telephone companies. These issues include the compatibility of transmission and compression technologies.

Vito Brugliera, Zenith Electronics VP of technology, market planning, said, "What's going on is what I call the battle for the set-top. It's really a battle for the front-end of the television receiver. Zenith is unique in that we're in both industries."

Under the 1992 Cable Act, the FCC was directed to address concerns that current analog-based cable converter boxes duplicate TV tuner functions; as a result, consumers have been to use capabilities such as picture-in-a-picture, record-and-watch and others.

The decoder interface, circulating in draft form, would put back much of that functionality in TV receivers but also provide a migration path to a digital compressed NTSC world. In addition to requiring better tuners that perform channel acquisition at 1GHz and beyond, the decoder interface includes a communications bus and radio frequency devices to bypass scrambled signals.

"The assumption is that there will be two categories of TV receivers. One (category) has to have a better tuner, better direct pick-up and it has to have this decoder interface," said Mr. Brugliera. "The decoder interface will be a defined connector and have input/out capabilities. The decoder interface will mate with setback devices that, when plugged into the TV set, will make the combination the equivalent of an addressable decoder. That will be transparent to the user."

While the decoder interface was originally conceived to address an analog world, the FCC is being asked to address wider issues, such as whether set-top decoder boxes for interactive TV systems should be treated as customer premise equipment (CPE) and subject like telephones to standardized features (EN, Feb. 7).

James Bonan, co-chair of the advisory group and a Sony executive, said, "Today's TV set can't receive the (digital) signal any more than it can receive a scrambled signal. We've agreed with the cable industry that a key part of solving the problem is to have digital transmission standards for cable."

While the HDTV "Grand Alliance" recently chose Zenith's vestigial sideband (VSB) modulation approach over General Instrument's quadrature amplitude modulation (QAM) scheme, Tele-Communications, Inc., and some other cable operators are leaning toward deployment of QAM for their purpose. In the meantime, GI is also attempting to license its dual-mode DigiCipherII/MPEG-2 compression technology to digital VCR makers. TV receiver makers and computer companies in addition to its established customer base (EN, March 21).

Mr. Bonan said the consumer electronics group and cable industry representatives have asked the FCC to seek compatibility in transmission, compression and encryption. "What is very much an issue now in Congress is that the information highway not recreate a situation in which the service provider is the exclusive source of connection equipment for their system and that the consumer has no alternative than to rent connection equipment from their service provider. It would be very logical to say, gee, we've got HDTV coming and that's digital, the cable guys want to do digital transmission and the telephone companies want to do digital transmission and somebody, maybe the FCC, should look at all this and create one rational system of standards that can be used nationally so we can have a coherent infrastructure."

One result of the new decoder interface is that TV receivers would come already equipped with much of the functionality envisioned for digital set-top terminals; Mr. Bonan said decoder interface has been designed "to have a fuzzy line on what features or functions would exist on both sides of that line, or on either side of that line."

Mr. Brugliera said Zenith is prepared to support both VSB and QAM in its products if necessary. "That's a marketplace decision, we will do it if the market insists upon it. Ideally the consumer would prefer the minimum cost solution. What's at stake here is that there are opposing transmission systems and we could wind up witth multiple standards, which from the consumer point of view is a pain."

However, Mr. Brugliera believes cable operators will ultimately support consumer electronics companies jumping into the market with "cable-ready" TV sets because that will save them capital investment in set-top converters.