Three Amigos Re-Examine NTSC Signals


A trio of seasoned cable engineers is offering up a way to
deliver both digital and analog video, at the same time, in the same channel.The scenario
promises to become a viable option soon for cable operators that haven't been able to
make an economic case for expensive digital set-tops, according to industry
veterans-turned-inventors Ted Hartson, Bob Dickinson and Walt Ciciora."I think that
the digital model [where cable operators give up precious bandwidth above 550 megahertz
and are forced to buy $400 digital set-tops] is broken," said Hartson, who has had a
long cable career, including a stint as Post-Newsweek Cable's vice president of

"There's a huge number of NTSC [National
Television Systems Committee] sets around, and we think that they'll be around for a
long, long time. People ought to figure out how to use them, and not put them out of
business," Hartson added.That is exactly what the cable industry's version of
the "Three Amigos" has done.By examining the nature and design of NTSC signals,
Hartson and his crew figured out a way to place up to two digital bit streams in a
standard NTSC signal, without affecting the performance of the existing signal.

The upshot? A threefold increase in the number of channels
that a cable operator can send over existing networks, all made possible by a headend
encoder that is projected to cost a "few hundred dollars" and a decoding chip
costing an order of magnitude less, according to Hartson.Hartson, who calls his
Scottsdale, Ariz.-based venture EnCamera Sciences Corp., has a working prototype in his
lab, and he was expected to file his last patent application in April. The next key step
-- funding -- is also expected to occur shortly, he said.

Unlike other approaches, the EnCamera solution doesn't
utilize the vertical-blanking interval to "hide" these signals. Instead, it
takes advantage of the inefficiencies in the 60-year-old NTSC standard and shoehorns up to
4.5 megabits per second of digital data near the visual and aural carriers."There are
many compromises in the NTSC standard," said Ciciora, the former Time Warner Cable
and Zenith Electronics Corp. engineering executive. "It was designed in the
vacuum-tube era. Today, you can do things that were out of the question back then. We do a
lot of headend processing, so the data are well-hidden, yet cost-effective to
extract."The EnCamera system delivers a high-speed digital stream (4.5 mbps over a
cable system; up to 3 mbps over the less-robust broadcast airwaves) that can be used for
virtually any application, whether it be video, data, or voice.

The additional capacity over cable networks is made
possible because unlike the broadcast environment, cable doesn't suffer from
co-channel interference, reflections and myriad other problems that can plague
over-the-air transmission, Ciciora said.

That said, however, Ciciora added that the EnCamera
technology would still be appealing to broadcasters that might want to add channel
capacity or send data within their analog signals.

Ciciora, who has championed numerous agreements with
consumer-electronics manufacturers in an attempt to improve compatibility between the two
industries, also said the technology could be used by cable operators to perform what he
calls the "compatible digital upgrade."

This allows an MSO to keep all of its bandwidth for analog
signals and to simply add a digital tier within it.Of course, the approach requires that
cable subscribers be given some sort of digital decoder. Hartson and company hope to
attract the attention of General Instrument Corp. and Scientific-Atlanta Inc., and to
convince them that the additional circuitry should be included in new set-tops.

Here, they'll probably be faced with the classic
chicken-and-egg conundrum -- unless a cable operator decides to adopt the approach and
creates market pull. With the contacts that these three have, that's not out of the
question. "Everyone that we've shown it to is intrigued," Hartson said.

Ciciora estimated that a fully integrated circuit could be
added to a set-top for about $20 in volume numbers, but he also noted that other devices,
such as DVD (digital versatile disc) players, would also be likely candidates for this
technology.All of this is nice, but isn't it already too late? The Federal
Communications Commission has ordered all of the broadcasters to use digital technology
and to abandon their analog feeds by 2006.

Ciciora, for one, remains hopeful. "We're not all
going digital," he argued. "Analog [receivers] will be around for a long time.
It's only the affluent who will be able to afford the first digital receivers, and
even they will have analog sets in their other rooms."Should this technology be
considered a breakthrough? None of the inventors was willing to go that far, but they were
quick to point out that there is some true innovation here.

"No one had ever approached the data rates that we
have achieved," said Dickinson, who also owns Dovetail Systems, a
signal-leakage-flyover company.

"We've done a lot of original work and stretched
the boundaries. There's a lot of originality and achievement here," Dickinson
added.Ciciora said, "We haven't invented something as significant as a
transistor, but we took things that we knew how to do and optimized it to the nth
degree."Hartson said he's now preparing to make some of the demonstration
equipment portable, so that he can take his invention on the road and demonstrate it. He
predicted that a limited field trial could occur as early as this autumn.

"We think that the business opportunity is
great," he said. "The worldwide possibilities are immense, because we're
getting to the point where there's no spectrum left."