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http://www.tvtechnology.com/features...N_Zenith.shtml

News: by Bob Kovacs

Is DTV Reception Problem Solved?
Zenith's receiver draws kudos

WASHINGTON

The scramble to switch television broadcasting to digital sometimes
overlooked what occurred at the final link in the over-the-air
broadcast chain: the viewer.

Although megabucks have been spent to upgrade stations and
simultaneously transmit analog and digital signals, stable and
reliable over-the-air DTV reception has been a crapshoot. However, the
latest generation of DTV receiver technology from LG/Zenith seems to
have solved the worst of the problems and is receiving praise from
both broadcasters and other interested parties.

Dubbed the "fifth-generation" receiver, the new technology has
converted some early DTV skeptics into believers.

"The performance that we got out of the fifth-generation receiver was
as good as what we had seen with COFDM," said Nat Ostroff, president
and CEO of Ai and vice president of new technology for Sinclair
Broadcasting in Hunt Valley, Md.

Ostroff recently observed tests of the LG/Zenith fifth-generation
receiver at several particularly difficult reception locations in
Baltimore, where Sinclair conducted tests of earlier receivers and
comparison tests using COFDM modulation. He had been outspoken in his
criticism of the early adoption of the 8-VSB modulation scheme by the
ATSC, pointing out that field tests up until now showed that reception
in many places was simply impossible.


THE CLIFF EFFECT

The 8-VSB transmission system adopted by the ATSC for DTV transmission
in the U.S. has had many critics among broadcasters and television
insiders, primarily because--until now--consistent reception in a
typical viewing environment was tricky at best. The term "cliff
effect" described what too often happened when watching DTV off the
air using earlier equipment: Either the signal looked perfect on the
TV or it completely dropped out, as if falling off a cliff.

The fifth-generation receiver was far more immune to the cliff effect
during Sinclair Broadcasting's tests of the receiver.

"We had always said that all we are interested in was a viable
over-the-air receiving system and we didn't have it," Ostroff said.
"When 8-VSB can be received as well as a COFDM signal, we'll be the
first to declare that to be the case and congratulate the winner, and
that's exactly what we've done."

Ostroff was enthusiastic about the potential of the fifth-generation
receiver.

"It's the only receiver so far that enables reception indoors with
simple antennas," he said.

The tests Ostroff witnessed in Baltimore used a simple bow-tie antenna
and he said reception was unperturbed by the movement of people in the
vicinity and even active vehicle traffic just a few feet away.

Sinclair Broadcasting's tests were informally duplicated and confirmed
by Mark Schubin, a well-known consulting engineer on television issues
and the creator of "Mark's Monday Memo" that discusses issues in
broadcasting.

Schubin has tried various 8-VSB DTV receivers in his New York
apartment with virtually no reception success, until he was able to
test an LG LST-3100A receiver--a fourth-generation model--that had
been upgraded with the fifth-generation DTV receiving and processing
technology.

Like Ostroff, Schubin reported that reception was stable while using a
simple set-top UHF antenna and people moved around the room.

"It was possible to find a location and orientation that caused
problems, but I had to really try," Schubin said in a recent issue of
the memo.

Richard Lewis, vice president of research and technology for Zenith,
said that the inner workings of this latest DTV receiver are a blend
of well-known techniques as well as some proprietary designs.

"The fifth-generation is a much more radical approach," Lewis said.
"It uses a 50 microsecond equalizer window to handle pre-ghost or
post-ghost [multipath] and was really focused on indoor reception and
ease-of-reception with simple antennas."

Earlier generations of receivers could also do pre- and post-ghost
correction but did not have the long pre-ghost window that the latest
generation has.

"The main change was a departure in architecture away from what had
been used [previously]," Lewis said. "It is proprietary so I can't
really get into the details, but it was a chance to throw out the old
design book and take a fresh start at it."


FAVORABLE RESPONSE

Other interested parties have all responded favorably to the tests
done with LG/Zenith's fifth-generation receiver.

Mark Richer, president of the ATSC, has been a leading proponent of
8-VSB modulation used in the U.S. for digital broadcasting.

"It has always been my view that 8-VSB receiver technology would
advance quickly," Richer said. "In this highly competitive
marketplace, you are going to see rapid advancement of DTV receiver
technology from a number of manufacturers."

Manufacturers feel that after years of vilification by broadcasters,
finally they've been vindicated.

"We've said over the years that ATSC reception would improve and I'm
glad that we were proven right," said Mike Petricone, vice president
of technology policy for the Consumer Electronics Association.

Sinclair Broadcasting's Ostroff said that his company is so excited
about the new possibilities of DTV that it produced public service
announcements to promote DTV for consumers. The spots are not specific
to Sinclair and the company is offering them free of charge to any
broadcaster as a way to generate viewer interest in DTV.

Others pursuing LG/Zenith's technology include USDTV, the Salt Lake
City broadcaster that has launched a pay over the air DTV service
using spectrum pooled from participating broadcasters. The company
recently announced it will use fifth-generation DTV receiver chips in
its latest set-top box and expects to ship the product by the end of
this year.

Lewis said that Zenith expects to ship the product this fall.

art

Sounds like a good advertisement for L/G products but for some strange
reason echos of "Gold Star" still ring in the halls of confusion.

john golitsis

That could be because LG stands for "Lucky Goldstar", which has always been the
company's name.

bobko

the entire thing here and wonder how it got here.

I agree that this is a very positive article about Zenith's 5th generation
DTV receiver technology. I have seen a prototype of this receiver and it
does work very well. Like many, I am skeptical about when it will reach
the public and how much it will cost, but I think that the LG/Zenith
people sincerely want to get this in stores by the end of the year. They
are running out of year, however.

When you work for a trade journal -- as I do -- it's tough to write a
hard-hitting article that might reflect negatively on your colleagues in
the industry. Heaven help it if you're reporting on a company that's an
advertiser.

However, I can tell you that Nat Ostroff of Sinclair Broadcasting and
Acrodyne/Ai (he's an official with these two related companies) is no
one's mouthpiece but his own. If he saw stringent tests and observed the
results, I believe him. I asked him directly about this and he said that
he personally observed Sinclair's tests and he could vouch for the
results. This is a guy that I take at his word... he has no reason to blow
sunshine up my skirt on this issue. He's an experienced TV transmission
engineer and knows what he's talking about.

So, I think this 5th generation technology is coming and it will work
well. I wish I was more certain about WHEN exactly is was coming.

--Bob Kovacs

bob miller

Its coming when its coming. 1st quarter most likely.

We tested the 5th gen receiver at Mark Schubin's apartment, in Midtown
Manhattan and at Richard Bogner's home on Long Island. It is very good.

And I am glad to see someone sticking up for Nat Ostroff who is one of
the last OTA engineers to stick up for the truth and say it like it is
even when unpopular in the ignorant halls of Washington D.C.

Here is what he had to say today on the subject on the OpenDTV forum.

"I am reading this thread (OpenDTV not this Newsgroup) and cannot
believe that the readers have forgotten
the bitter fight that I and others put up to get the option to have a COFDM
alternative placed in the ATSC standard. After several years of fighting
intentional misinformation and political manipulation of technical data we
lost that battle. Unfortunately the song lyric that says "you don't know
what you got till it is gone" seems to apply to our current situation.

We do have Zenith to thank for sticking with their promise to make
significant improvements to 8VSB reception. For that we all should be
grateful. Unfortunately we don't have the advantage of a COFDM service with
all of its mobile and small antenna reception options but at least we have
something that might serve as a fixed indoor service for over the air DTV.
Of course the advantages of COFDM are going to be enjoyed by companies like
Qualcom who are building a COFDM based service on a nationwide basis using
the TV UHF frequency band. The present outcome is to their advantage and our
distress.

Nat Ostroff"

COFDM is coming to the US in a big way, it will blow broadcasters off
the air if they do not switch to a better modulation. And as I have said
many times before when broadcasters really feel the fear they will ask
for and get the needed change in modulation in a heartbeat. With NO
consideration to any number of 8-VSB receivers that may be in the field.
And that is an easy statement to make even in light of the new minimally
acceptable 8-VSB 5th gen receiver which is very good only in comparison
to the junk that has gone before. 5th gen is not comparable to what most
of the world enjoys or will enjoy with COFDM.

Bob Miller

mark crispin

Remember, Bob Miller is a known crackpot and snake-oil salesman who
believes that better antennas do nothing to fix reception problems.

Everything that Bob Miller says, the opposite is true.

-- Mark --

http://staff.washington.edu/mrc
Science does not emerge from voting, party politics, or public debate.
Si vis pacem, para bellum.

toor

In article <1OHbd.3559$6k2.1580@newsread3.news.pas.earthlink. net>,
Bob Miller <robmx@earthlink.net> writes:

Remember: the new (originally planned for HDTV) DTV service was meant
to provide for stationary reception of HDTV. Extra things (hopefully
only taking 1% of the payload) are of little consequence to the
consumer. Excess diversion of the payload by decreasing HDTV quality
tends to violate the original reason for the change. There were
also other reasons developed like modifying the TV spectrum usage,
and those seem to be prominent for those who want to reuse the
low-VHF and some of the UHF spectrum.

For true, high quality non-TV digital services, then one should
demand BIDIRECTIONAL capability. Alas, even COFDM SFNs along with
magic dust isn't going to do that job correctly.

John

gaf1234567890

Hi Bob,

I have a question, and hope that you (or someone else) will know the
answer, or be able to at least shed some light on the subject, because
I don't see much discussion about it so far.

I was planning on getting an OTA HDTV receiver as close to the
deadline requiring devices to support the new broadcast flags as
possible (mid 2005). In other words, I would like to get the best/last
generation of receiver WITHOUT hardware support for the flags. Do you
know if the new LG/Zenith product will fall into that category? More
to the point, is any part of the delay shipping the product related to
that mandate?

Thanks in advance.

gaf1234567890

Hi Bob,

I have a question, and hope that you (or someone else) will know the
answer, or be able to at least shed some light on the subject, because
I don't see much discussion about it so far.

I was planning on getting an OTA HDTV receiver as close to the
deadline requiring devices to support the new broadcast flags as
possible (mid 2005). In other words, I would like to get the best/last
generation of receiver WITHOUT hardware support for the flags. Do you
know if the new LG/Zenith product will fall into that category? More
to the point, is any part of the delay shipping the product related to
that mandate?

Thanks in advance.

bob miller

I can answer that. There is no delay in shipping the product. It is a
new product that mainly concerns the tuner. That is a 4th gen receiver
with a swapped out tuner becomes the equivalent of a 5th gen receiver.
That in fact is what was tested by Sinclair and ourselves in New York.

The Mandate starts as of July 31st 2005. Any receiver sold before should
not include it. Expect such receivers first quarter 2005.

Also expect inexpensive LG receivers with MPEG4 AVC after July.