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Over the air TV to stop?

J

James Goforth

Jan 1, 1970
0
I have been seeing ads on the TV stating that there's some kind of
movement which supposedly threatens to end over-the-air TV broadcasts to
the public -- which doesn't make much sense after all the hassle of
changing over to Digital broadcasts. What are they talking about?
It doesn't elaborate on it, and what is even more strange, it doesn't
even have a website to visit for more info.
 
S

Sjouke Burry

Jan 1, 1970
0
James said:
I have been seeing ads on the TV stating that there's some kind of
movement which supposedly threatens to end over-the-air TV broadcasts to
the public -- which doesn't make much sense after all the hassle of
changing over to Digital broadcasts. What are they talking about?
It doesn't elaborate on it, and what is even more strange, it doesn't
even have a website to visit for more info.
They might ram internet broadcast down your (our) throat.
 
R

Rich Webb

Jan 1, 1970
0
I have been seeing ads on the TV stating that there's some kind of
movement which supposedly threatens to end over-the-air TV broadcasts to
the public -- which doesn't make much sense after all the hassle of
changing over to Digital broadcasts. What are they talking about?
It doesn't elaborate on it, and what is even more strange, it doesn't
even have a website to visit for more info.

Possible. A link to some of the rumors at
<http://beforeitsnews.com/story/2738/The_End_of_Free_Broadcast_Television?>

OTOH, over the air digital is [typically | often | always] (I don't have
good citations) of better quality than cable or satellite, as it may not
be as heavily compressed. This could argue for *more* interest in OTA
HDTV broadcasts.

OTOH, if it's digital then it can be encrypted, so it may be OTA but
potentially no longer free.

OTOH, revenue is revenue and a relatively small proportion of the
population is OTA only (raises hand). Dumping it altogether and
auctioning the spectrum could be a quick cash infusion for the Treasury.

One other item I've seen written about that is being considered is to do
away with the One Big Antenna system and to seed the service area with
multiple, low-power transmitters on the cell infrastructure. The
reasoning seems to be that the ghost rejection in existing DTV receivers
is already pretty good and could be improved in step with the antenna
transitions. The result may be cheaper for the broadcaster and could
potentially allow more OTA channels in a given region.
 
P

Paul Keinanen

Jan 1, 1970
0
One other item I've seen written about that is being considered is to do
away with the One Big Antenna system and to seed the service area with
multiple, low-power transmitters on the cell infrastructure. The
reasoning seems to be that the ghost rejection in existing DTV receivers
is already pretty good and could be improved in step with the antenna
transitions.

Is it really possible to use on-channel gap fillers and even build a
single frequency network (SFN) using 8VSB DTV ?

I was under the impression that only COFDM DVB-T could properly
support SFN.
The result may be cheaper for the broadcaster and could
potentially allow more OTA channels in a given region.

In Finland two new VHF multiplexes for HDTV are currently bering built
using COFDM DVB-T2 by a cellular phone company, using their existing
medium to small (less than 100 m) masts instead of large 300 m masts
traditionally used for broadcasting.

The exact same signal is radiated at the same frequency from all
transmitters in the area, so in practice, a receiver could get a few
thousand subcarriers from one transmitter and the rest from the other
transmitter, if there is deep nulls due to multipath on some
subcarriers from the first transmitter.
 
S

starrin

Jan 1, 1970
0
I have been seeing ads on the TV stating that there's some kind of
movement which supposedly threatens to end over-the-air TV broadcasts to
the public -- which doesn't make much sense after all the hassle of
changing over to Digital broadcasts. What are they talking about?
It doesn't elaborate on it, and what is even more strange, it doesn't
even have a website to visit for more info.
www.avsforum.com/avs-vb/showthread.php?t=1192114
 
M

Mark Zenier

Jan 1, 1970
0
I have been seeing ads on the TV stating that there's some kind of
movement which supposedly threatens to end over-the-air TV broadcasts to
the public -- which doesn't make much sense after all the hassle of
changing over to Digital broadcasts. What are they talking about?
It doesn't elaborate on it, and what is even more strange, it doesn't
even have a website to visit for more info.

A bunch of the high tech outfits want to use the TV bands for part 15
liscense free wi-fi stuff. This proposed equipment is supposed to be
smart enough to not jam an active channel, but that's wishful engineering.

Mark Zenier [email protected]
Googleproofaddress(account:mzenier provider:eskimo domain:com)
 
C

Charles

Jan 1, 1970
0
James Goforth said:
I have been seeing ads on the TV stating that there's some kind of
movement which supposedly threatens to end over-the-air TV broadcasts to
the public -- which doesn't make much sense after all the hassle of
changing over to Digital broadcasts. What are they talking about?
It doesn't elaborate on it, and what is even more strange, it doesn't
even have a website to visit for more info.

It's called scrambling for limited resources. The RF spectrum is a limited
resource. Currently, radio and TV broadcasters (and others) own a large
chunk of it. Well, ownership can and will change in this brave new world.
As the Microsofts and the Googles continue to gain more control of the
economy, they want more resources.

It's not necessarily a bad or evil thing. Actually, wideband Internet
delivery of content can do much more (a better job in many cases) than
conventional broadcasting. I see the giant competitors merging in the near
future, if the Democrats will allow that to happen.
 
P

Paul Keinanen

Jan 1, 1970
0
A bunch of the high tech outfits want to use the TV bands for part 15
liscense free wi-fi stuff. This proposed equipment is supposed to be
smart enough to not jam an active channel, but that's wishful engineering.

If there are empty channels, the broadcasters are not using
effectively the frequencies allocated for broadcasting.
 
D

Don Bruder

Jan 1, 1970
0
Paul Keinanen said:
If there are empty channels, the broadcasters are not using
effectively the frequencies allocated for broadcasting.

Maybe, maybe not - Say channel 6 (just pulling one out of thin air for
use as an example), is "empty" in "Town A". That doesn't mean channel 6
isn't being used - It could very well be that it's been deliberately
left "empty" there because in "Town B", there's a station transmitting
on it, and if someone were to fire up a transmitter in "Town A" on
channel 6, it would step on (or be stepped on by) the transmitter in
"Town B".

In which case, letting Joe-whoever transmit Wi-Fi on it would very
likely cause unacceptable interference to reception in "Town A", and
depending on the power levels involved, could potentially cause trouble
in "Town B" as well.

Also, keep in mind that *THE BROADCASTERS* have *VERY* little control
over which channels they're able to use - Sure, everybody and his dog
could say "I'm using this channel", but there's this entity here in the
USA called the FCC, and they've pretty much been made the "dictator for
life" in almost all aspects of what happens where on the radio spectrum.
You want to start broadcasting? You ask the FCC for permission, and in
most cases, they tell you which channel you can use, regardless of what
channel you might want. You don't play by their rules, they fine you
multiple thousands of dollars per day until you can't afford to make the
mortgage payments and have to shut down for lack of a place to broadcast
from, and/or they come pull your plug for you.
 
P

Paul Keinanen

Jan 1, 1970
0
Maybe, maybe not - Say channel 6 (just pulling one out of thin air for
use as an example), is "empty" in "Town A". That doesn't mean channel 6
isn't being used - It could very well be that it's been deliberately
left "empty" there because in "Town B", there's a station transmitting
on it, and if someone were to fire up a transmitter in "Town A" on
channel 6, it would step on (or be stepped on by) the transmitter in
"Town B".

If the intention is to serve Town A with Program A and nearby Town B
with Program B on the same channel, then the old tradition to use a
single 300 m tower in each town will fail.

According to claims in this threads that even current ATSC 8VSB
receivers would be capable of operating with some kind of single
frequency network (SFN), using lo to medium power transmitters on
medium height poles within the town, will help to concentrate the
signal to the intended reception area and keeping the spill over to
adjacent cells at acceptable level.
In which case, letting Joe-whoever transmit Wi-Fi on it would very
likely cause unacceptable interference to reception in "Town A", and
depending on the power levels involved, could potentially cause trouble
in "Town B" as well.

This is known as the "hidden transmitter problem" as in any CSMA
network, in which a device in an unfavorable location can not hear
that there is some other activity on the channel. Thus the device will
fire up the transmitter thinking that the channel is free.

I don't think that those devices are going to cause problems in
locations, in which the TV signal is strong enough for indoor
antennas, since also the device most likely will hear some activity on
the channel, even if the signal level would be insufficient for TV
reception at that spot.

The situation gets complicated when the TV signal strength is so low
that directional outdoor antennas must be used. A device in the
basement would get no TV signal at all and thinking that the channel
is free, fire up the transmitter and cause interference to TV
reception.

A SFN style TV network would help to keep the TV signal level at
sufficient levels even indoors, preventing the device from
transmitting on that channel.

Also, keep in mind that *THE BROADCASTERS* have *VERY* little control
over which channels they're able to use - Sure, everybody and his dog
could say "I'm using this channel", but there's this entity here in the
USA called the FCC, and they've pretty much been made the "dictator for
life" in almost all aspects of what happens where on the radio spectrum.

Practically every country has such organizations for frequency
coordination. However, at least in US the broadcasters have had a very
strong lobby groups influencing the FCC.

Frequency bands are allocated for various services such as
broadcasting by international agreement within ITU-R (ex CCIR) and the
allocation is more or less the same at least within a continent.

In the US, the demands for setting up your own TV station is so high
that available spectrum would not be sufficient and the FCC tries to
arbitrate between the various players in the broadcast industry. You
enemy is not the FCC but the next door TV station, competing for
frequencies and for income from advertisement.

The relative importance of broadcasting has been reduced with much new
technology used by the majority of people, so for instance cellular
phone lobby groups have much more influence on FCC and similar
organizations worldwide.

The cellular and Wi-Fi industry has traditionally had only very narrow
frequency bands (compared to broadcasting) and hence frequency
efficiency has been very important from the start.

However, in broadcast industry, the frequency efficiency has been
quite bad and the only improvement in frequency efficiency since the
1930's was the digitalization, allowing 4-6 times the number of
channels compared to the analog era. On the network level, the
spectral efficiency is still poor compared to the cellular phone
industry.
 
P

Paul Keinanen

Jan 1, 1970
0
Sigh. Read up on 'The 150 mile rule'. TV frequencies are subject to
skip, ghosting, signal fade and a lot of other problems. Also there are
grade 'A' and grade 'B' coverage areas.

You still seem to be living in the analog era with big transmitter
towers :).
I got a letter at a TV station
who's transmitter is near Daytona Beach back in the '80s from a man in
west Texas reporting that he had a clear signal for a few minutes short
of eight hours one evening.

I am fully aware of tropospheric ducting an other tropospheric
propagation modes.

The only surprising thing is that the transmitter was on the East cost
of Florida. Typically this kind of ducting occurs only a few meters
above water. Radio amateurs have made contacts up to 1000 km up to 10
GHz with antennas just a few meters above the water front, while
antennas a few meters higher were useless.

Perhaps the transmitted signal had reached an elevation just few
meters above the sea level, when it reached the West cost of Florida,
before being ducted into Texas.

Some broadcasting companies have done quite a lot measurements for
decades to detect such propagation anomalies and the potential for
interference to their services. Practical experience also show that
the interference could be so bad that the intended audience is not
reached.

One might expect that similar propagation anomalies would cause havoc
to cellular phone networks (similar to trying to use a cellular phone
in an aeroplane), but I have never heard of problems due to
tropospheric propagation. Apparently the lower tower heights and the
higher signal levels at the intended service area, will handle most of
these problems.
 
B

Baron

Jan 1, 1970
0
Paul Keinanen Inscribed thus:
You still seem to be living in the analog era with big transmitter
towers :).


I am fully aware of tropospheric ducting an other tropospheric
propagation modes.

The only surprising thing is that the transmitter was on the East cost
of Florida. Typically this kind of ducting occurs only a few meters
above water. Radio amateurs have made contacts up to 1000 km up to 10
GHz with antennas just a few meters above the water front, while
antennas a few meters higher were useless.

I can confirm that. I've got confirmed qls of 2000 miles on VHF and
1200 miles on UHF. Winding the tower up caused the signals to get
weaker and disappear. Another local ham 60ft higher than me broke in
to ask who I was talking to, because he couldn't hear the other side.
Perhaps the transmitted signal had reached an elevation just few
meters above the sea level, when it reached the West cost of Florida,
before being ducted into Texas.

Some broadcasting companies have done quite a lot measurements for
decades to detect such propagation anomalies and the potential for
interference to their services. Practical experience also show that
the interference could be so bad that the intended audience is not
reached.

Dutch VHF television used to be an everyday occurrence here the UK.
 
K

Kevin McMurtrie

Jan 1, 1970
0
Charles said:
It's called scrambling for limited resources. The RF spectrum is a limited
resource. Currently, radio and TV broadcasters (and others) own a large
chunk of it. Well, ownership can and will change in this brave new world.
As the Microsofts and the Googles continue to gain more control of the
economy, they want more resources.

It's not necessarily a bad or evil thing. Actually, wideband Internet
delivery of content can do much more (a better job in many cases) than
conventional broadcasting. I see the giant competitors merging in the near
future, if the Democrats will allow that to happen.

The first problem I have with all of this that US telcos are a national
embarrassment. They state that the FCC has no right to control their
Internet services as a public utility yet any competition with them
unleashes lawsuits for unlawful competition with a public utility.
Until the FCC grows a pair, I'd rather have TV over the air than through
the telcos.

The second problem I have with this is Google. Google doesn't really
give a crap about wireless broadband. Google wants whitespace WiFi
because they're going to solve interference problems using a large
geolocation database that can pinpoint exactly where ever Internet
customer is. I know it sounds too crazy to be true, but search for
"google geolocation service" and you'll see that it's already online.
 
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