Urlman: i believe Genroco's product is the MAC but I may be wrong; does anyone know for sure. i remember when i spoke w/ grci the fellow explained that its product interfaced between the QAM and the front-end........bob
From the Systems pages of Electronic News: September 21, 1998 Issue
Software
Digital TV: Satellite Vs. Cable
By Carolyn Whelan
New York--Digital TV goes live on Nov. 1. Want to be one of the first to
see High Definition Television (HDTV), at home? Better get a satellite
dish, then, and an off-air antenna. That is unless you're among the
lucky pockets of population living in one of 24 metropolises blessed
with DTV this fall. Or residing in a few big cities where digital cable
is currently being rolled out. Still, only 10 percent of U.S. households
currently have that capability. And whatever the pipeline, 70 percent of
U.S. homes still won't have access to digital broadcasts by the end of
next year.
Satellite is the only medium that provides immediate, ubiquitous
coverage of digital television. A flick on, nationwide footprint
instantaneously. As such, the industry is hoping to beat cable and
broadcasters to the punch in the digital TV race.
"It's very exciting," said a satellite executive at last week's Skyforum
in New York City. "Satellite will jumpstart the arrival of digital
television."
In the U.S., high bandwidth cables that pave the way for digital cable
are the exception rather than the rule. Among some 98 U.S. million
homes, only about 83 million have been passed by cable TV systems.
Furthermore, just under 68 million households are actual subscribers,
and a mere 10 million are already equipped with two-way capabilities.
All figures are from Cahners In-Stat, unless otherwise noted.
What's In A Cable Box?
In a nutshell, cable modems are stripped down Digital cable set top
boxes. Both have the same front end: a tuner, which receives digital
streams and picks up the frequency; a QAM chip (Quadrature Amplitude
Modulation) demodulator, which demodulates the QAM signal; and an FEC
(Factual Error Correction), which uses digital signal processing
techniques to eliminate and correct errors. The Modulator chip modulates
data to be sent upstream through the QPSK (Quarternary Phase Shift
Keying). Digital Cable adds on an EM interface chip to connect the cable
to Ethernet, an MPEG video decoder, and a Media Access Controller (MAC).
Much like a traffic cop, the MAC, which sits between the QAM and FEC,
decides where and when to receive or send data.
But though satellite may lead the pack into the digital century, cable,
with its two-way capabilities continues to be a formidable contender.
In spite of its headstart and recent inroads satellite has made into the
cable subscriber base (particularly big-spending, Joe six-pack types),
over the long term, analysts expect digital cable to pull ahead, due to
the many applications that will be available to consumers (see chart, p.
46).
Two-way interactivity, voice telephony, high-speed data streaming,
Internet access, and of course the choice of hundreds of cable channels,
with, eventually, most of them digital--not to mention video on demand,
down the line--are among applications that will be available to digital
cable subscribers.
Consequently, cable will have more revenue-generating possibilities.
"The U.S. market for local telephone access is $85 billion, so there's
some money to be made," said Gerry Kaufhold, a multimedia analyst at
Cahners In-Stat. "It's going to happen very slowly, but it will drive a
lot of semiconductors, on a city by city rollout."
The growth spells out big opportunity for chip makers, many of whom have
set their sights on supplying chips to OEMs for cable modem boxes. Both
boxes use the same sorts of chips. Many people confuse cable modems and
digital cable, for that very reason (see box). But though cable modems
enable digital streaming on PCs (much of which may be generated by
networks), they can't receive digital broadcasts. Digital cable can.
For interactivity, many technologists prefer digital cable because it is
wired and two-way. It also provides more bandwidth to selected homes
than any other source. The technology will deliver six to ten times
current compression rates versus two times for HDTV. Others are voting
for cable due to its off -the-air quality.
Other factors may impede the use of satellite for digital broadcasts,
and, subsequently, deter long-term buy-in to the technology as a medium
for receiving digital content.
Since the HDTV signal takes up more bandwidth, satellite stations will
initially offer only two (out of several hundred) channels in high
definition. However, the exception, Unity Motion, is going online, 24
hours a day, 7 days a week, with 24 channels of HDTV programming,
nationwide.
Another stumbling block is content. The only digital content available
in the first 12 months of HDTV will be movies, which are already in high
definition with wide screen capabilities. But, since most films are
owned by Time Warner, which also happens to own several cable companies,
Time Warner could easily limit its supply of movies to satellite
providers.
Still one more strike against satellite, over the long term, is a lack
of access to network programming. Last year the National Association of
Broadcasters successfully sued satellite providers, preventing them from
using a satellite system to access programming from the big four
networks. Despite the fact that satellite viewers can surf several
hundred channels, unless they buy a local antenna or networks sign a
waiver granting them access, viewers can't watch their favorite weekly
network episodes.
So who is going to win?
Technology issues aside, timing will be an enormous factor in the early
rounds of selection. And yet to be seen are the roles other technologies
will play in delivering digital entertainment (see sidebar). But by and
large, early on, broadcasters, satellite and cable will dominate the
mass market.
Finally, satellite has its very low, 8 million subscribers, or 8 percent
of households penetration rate working against it.
And a few issues have yet to be resolved. Unanswered still is whether or
not digital cable will be able to carry all digital channels. Also, some
say that in terms of bandwidth, three satellites can match the
throughput of high definition television. And, some broadcasters are
leaning toward satellite as a way to usurp control from cable operators.
Whatever wins out, OEMs should keep mid-1999 top of mind. That's when a
digital TV product becomes a viable product to sell at retail. |
