Sign in with
Sign up | Sign in
Your question

AM Radio for TV (again)

Last response: in Home Theatre
Share
Anonymous
April 19, 2004 10:08:11 AM

Archived from groups: alt.video.digital-tv (More info?)

My idea for providing the "15%" in the USA with some sort of OTA
TV after the NTSC OTA TV signals are turned off:

Use the RealPlayer codec (for example) and a regular AM radio
transmitter to provide digital LDTV.

AM radio has been in use for over 80 years and the types of
channel impairments in the AM band should be well documented, so
finding a suitable error correction scheme should be fairly easy.

The AM radio audio would be replaced with the RealPlayer + error
correction datastream (not a DRM type system, the AM radio
transmission system would not be modified).

STBs using hardware RealPlayer decoders shouldn't be very
expensive (probably much less expensive than ATSC DTV/HDTV STBs).

Kirk Bayne
alt.video.digital-tv Home Page
<http://www.geocities.com/lislislislis/avdtv.htm&gt;

More about : radio

April 19, 2004 6:08:51 PM

Archived from groups: alt.video.digital-tv (More info?)

"K. B." <hotmail.com@lis2lis2> wrote in message
<
> STBs using hardware RealPlayer decoders shouldn't be very
> expensive (probably much less expensive than ATSC DTV/HDTV STBs).

But people will still be forced to go out a buy new equipment, if you're
going to do that then why not just buy a proper ATSC box? The cost of most
kit comes down to distribution, marketting and packaging costs rather than
their contents.

Az.
Anonymous
April 19, 2004 10:47:07 PM

Archived from groups: alt.video.digital-tv (More info?)

Gegroet,

Op Ma, 19 Apr 2004 06:08:11 +0000, schreef K. B.:
> My idea for providing the "15%" in the USA with some sort of OTA
> TV after the NTSC OTA TV signals are turned off:
> Use the RealPlayer codec (for example) and a regular AM radio
> transmitter to provide digital LDTV.
> AM radio has been in use for over 80 years and the types of
> channel impairments in the AM band should be well documented, so
> finding a suitable error correction scheme should be fairly easy.
(...)

I'm sorry but I just got lost.

Are you talking about the same 10 KHz channels at 530 Khz to 1600 Khz (or
1700 Khz) ow used for AM radio-broadcasting?

The IBOC-people and DRM are finding it difficult enough to fit sufficient
bits for a single audio-channel in that. How on earth do you propose to
put a TV-channel in there?


> Kirk Bayne
Cheerio! Kr. Bonne.
--
Kristoff Bonne, Bredene, BEL
H323 VoIP: callto://krbonne.homelinux.net/
[nl] [fr] [en] [de]
Related resources
Anonymous
April 19, 2004 11:54:41 PM

Archived from groups: alt.video.digital-tv (More info?)

On Mon, 19 Apr 2004 18:47:07 +0200, Kristoff Bonne
<kristoff.bonne@compaqnet.nospam.be> posted:

>Gegroet,
>
>Op Ma, 19 Apr 2004 06:08:11 +0000, schreef K. B.:
>> My idea for providing the "15%" in the USA with some sort of OTA
>> TV after the NTSC OTA TV signals are turned off:
>> Use the RealPlayer codec (for example) and a regular AM radio
>> transmitter to provide digital LDTV.
>> AM radio has been in use for over 80 years and the types of
>> channel impairments in the AM band should be well documented, so
>> finding a suitable error correction scheme should be fairly easy.
>(...)
>
>I'm sorry but I just got lost.
>
>Are you talking about the same 10 KHz channels at 530 Khz to 1600 Khz (or
>1700 Khz) ow used for AM radio-broadcasting?

Yes

>The IBOC-people and DRM are finding it difficult enough to fit sufficient
>bits for a single audio-channel in that. How on earth do you propose to
>put a TV-channel in there?

RealPlayer works over regular dial-up internet connections
(albeit with what would charitably be called a Low Definition
picture) and the bandwidth of regular AM radio is comparable to
dial-up.

The RealPlayer + error correction datastream would be substituted
for the audio and modulate the regular AM radio carrier, no
additional bandwidth would have to be allocated for my proposed
AM radio band digital LDTV station.

Kirk Bayne
alt.video.digital-tv Home Page
<http://www.geocities.com/lislislislis/avdtv.htm&gt;
Anonymous
April 20, 2004 2:38:02 AM

Archived from groups: alt.video.digital-tv (More info?)

Gegroet,

Op Ma, 19 Apr 2004 19:54:41 +0000, schreef K. B.:
>>The IBOC-people and DRM are finding it difficult enough to fit sufficient
>>bits for a single audio-channel in that. How on earth do you propose to
>>put a TV-channel in there?

> RealPlayer works over regular dial-up internet connections
> (albeit with what would charitably be called a Low Definition
> picture) and the bandwidth of regular AM radio is comparable to
> dial-up.
> The RealPlayer + error correction datastream would be substituted
> for the audio and modulate the regular AM radio carrier, no
> additional bandwidth would have to be allocated for my proposed
> AM radio band digital LDTV station.

Wait.

The IBOC/HDradio specification say they achieve two 20 Kbps channels
in "relative robustness 2" (whatever that may be).

The DRM spec gives 26.6 Kbps net bitrate in 'spectral mode 3' (i.e. 10
KHz), Robustness mode A (least guard interval), QAM64 and Coding-rate 0.6.
(If you choose a coding-rate 0.5, this should be some 32 Kbps).

Now, you propose to put a TV-channel (video and audio) plus the original
AM radio-station into 30 to 40 Kbps?

IIRC, the BBC uses 40 Kbps for there videostreaming on their news website.
(just try one of the videos on http://news.bbc.co.uk/)

I don't think you can really call this 'television quality', can you?


On the other hand.

The VRT (the public broadcaster for the dutch-language part of Belgium)
uses 150 Mbps MPEG 4. The worlddab forum proposes using 1.3 Mbps MPEG 4
video for DMB (video over DAB).


Perhaps you could go back to the days of old AM-television:
http://earlytelevision.org/ ;-)

(BTW. Great website!!!)

>Kirk Bayne
Cheerio! Kr. Bonne.
--
Kristoff Bonne, Bredene, BEL
H323 VoIP: callto://krbonne.homelinux.net/
[nl] [fr] [en] [de]
Anonymous
April 20, 2004 3:48:35 AM

Archived from groups: alt.video.digital-tv (More info?)

On Mon, 19 Apr 2004 22:38:02 +0200, Kristoff Bonne
<kristoff.bonne@compaqnet.nospam.be> posted:

>Now, you propose to put a TV-channel (video and audio) plus the original
>AM radio-station into 30 to 40 Kbps?

My proposal would be a substitute for the AM radio audio, anyone
tuning a regular AM radio to the station would hear noise
(similar to the noise on a voice telephone line when using a
modem).

I typically get about 50kbps with my dial-up connection (IIRC,
home telephone voice line bandwidth is about 4kHz) and RealPlayer
works OK (although the variable latency of the Internet causes
problems).

AM radio typically offers a bandwidth of about 5kHz.

>I don't think you can really call this 'television quality', can you?

No, it'd be LDTV, sort of a "lifeline" OTA TV service for people
who don't have ATSC DTV/HDTV or cable or satellite systems.

>Perhaps you could go back to the days of old AM-television:
>http://earlytelevision.org/ ;-)

Hence the (again) in the subject line. :) 

Kirk Bayne
alt.video.digital-tv Home Page
<http://www.geocities.com/lislislislis/avdtv.htm&gt;
Anonymous
April 21, 2004 1:56:54 PM

Archived from groups: alt.video.digital-tv (More info?)

Gegroet,

Op Ma, 19 Apr 2004 23:48:35 +0000, schreef K. B.:
>>Now, you propose to put a TV-channel (video and audio) plus the original
>>AM radio-station into 30 to 40 Kbps?

> My proposal would be a substitute for the AM radio audio, anyone
> tuning a regular AM radio to the station would hear noise
> (similar to the noise on a voice telephone line when using a
> modem).
> I typically get about 50kbps with my dial-up connection (IIRC,
> home telephone voice line bandwidth is about 4kHz) and RealPlayer
> works OK (although the variable latency of the Internet causes
> problems).
> AM radio typically offers a bandwidth of about 5kHz.

Well, AM radio path is very different of that of a typical telephone line
(e.g. concerning multipath), but you also have to take into account that
radio is a one-way system while an IP-network is two-way.
As a one-way network needs a forward error-correction mechanism, you loose
somewhere between one thirth and half of you throughput only for that!


But the discussion is all pretty academic. 30, 40 or even 50 KBps is way
to few for a TV signal and anywhere near "viewable for more then 30
seconds".


> No, it'd be LDTV, sort of a "lifeline" OTA TV service for people
> who don't have ATSC DTV/HDTV or cable or satellite systems.

Hmm. In what senario do people not have access to either OTA or
satellite?


> Kirk Bayne
Cheerio! Kr. Bonne.
--
Kristoff Bonne, Bredene, BEL
H323 VoIP: callto://krbonne.homelinux.net/
[nl] [fr] [en] [de]
Anonymous
April 21, 2004 1:56:55 PM

Archived from groups: alt.video.digital-tv (More info?)

On Wed, 21 Apr 2004 09:56:54 +0200, Kristoff Bonne
<kristoff.bonne@compaqnet.nospam.be> posted:

>As a one-way network needs a forward error-correction mechanism, you loose
>somewhere between one thirth and half of you throughput only for that!

It doesn't have to be (near) perfect data transmission, it should
work most of the time though (the receiver/STB can deal with a
loss of signal by muting the audio and freezing the last complete
picture until the signal is restored, for example).

>But the discussion is all pretty academic. 30, 40 or even 50 KBps is way
>to few for a TV signal and anywhere near "viewable for more then 30
>seconds".

Another option would be to provide continuous audio and "slide
show" video (new pictures no more often than every 1/2 second,
for example).

>> No, it'd be LDTV, sort of a "lifeline" OTA TV service for people
>> who don't have ATSC DTV/HDTV or cable or satellite systems.
>
>Hmm. In what senario do people not have access to either OTA or
>satellite?

In the USA, the government wants the OTA NTSC transmitters turned
of as soon as possible and the minidish satellite systems can't
be used in some areas and are subscription only.

My proposal would be low cost option for people can't or won't
get an ATSC DTV/HDTV receiver (and antenna).

Kirk Bayne
alt.video.digital-tv Home Page
<http://www.geocities.com/lislislislis/avdtv.htm&gt;
Anonymous
April 21, 2004 4:24:38 PM

Archived from groups: alt.video.digital-tv (More info?)

On Wed, 21 Apr 2004 08:34:35 GMT, K. B. wrote:

> On Wed, 21 Apr 2004 09:56:54 +0200, Kristoff Bonne
> <kristoff.bonne@compaqnet.nospam.be> posted:
>
>>As a one-way network needs a forward error-correction mechanism, you loose
>>somewhere between one thirth and half of you throughput only for that!
>
> It doesn't have to be (near) perfect data transmission, it should
> work most of the time though (the receiver/STB can deal with a
> loss of signal by muting the audio and freezing the last complete
> picture until the signal is restored, for example).

Well, that type of QoS is not very good, isn't it?
I think it's way below the limit of what is considered acceptable for
broadcast.


>>But the discussion is all pretty academic. 30, 40 or even 50 KBps is way
>>to few for a TV signal and anywhere near "viewable for more then 30
>>seconds".
>
> Another option would be to provide continuous audio and "slide
> show" video (new pictures no more often than every 1/2 second,
> for example).

Well, 2 fps would give you a very strong headache, I guess. It's too
fast for a slide show, and too slow for a moving picture as in normal
television.
I think it's better to refresh the picture once in every 3 or 5 seconds
or so. That's somewhat more of a decent slide show.


>>> No, it'd be LDTV, sort of a "lifeline" OTA TV service for people
>>> who don't have ATSC DTV/HDTV or cable or satellite systems.
>>
>>Hmm. In what senario do people not have access to either OTA or
>>satellite?
>
> In the USA, the government wants the OTA NTSC transmitters turned
> of as soon as possible and the minidish satellite systems can't
> be used in some areas and are subscription only.
>
> My proposal would be low cost option for people can't or won't
> get an ATSC DTV/HDTV receiver (and antenna).

Well, like Kristoff, I think that POTS is too little, too less. Maybe
you can use DSL connections for that, as they provide more capacity.
However, I think it still won't be available in all areas.

--

mvg,
Giovanni.
Anonymous
April 21, 2004 8:18:47 PM

Archived from groups: alt.video.digital-tv (More info?)

Within these hallowed halls, Aztech of <az@tech.com> added the
following to the collective conscience:
> "K. B." <hotmail.com@lis2lis2> wrote in message
> <
>> STBs using hardware RealPlayer decoders shouldn't be very
>> expensive (probably much less expensive than ATSC DTV/HDTV STBs).
>
> But people will still be forced to go out a buy new equipment, if
> you're going to do that then why not just buy a proper ATSC box? The
> cost of most kit comes down to distribution, marketting and packaging
> costs rather than their contents.
>
> Az.

Agreed, however the thread lives on.
Anonymous
April 21, 2004 10:56:41 PM

Archived from groups: alt.video.digital-tv (More info?)

Greetings,

Op Woe, 21 Apr 2004 08:34:35 +0000, schreef K. B.:
>>As a one-way network needs a forward error-correction mechanism, you loose
>>somewhere between one thirth and half of you throughput only for that!
> It doesn't have to be (near) perfect data transmission, it should
> work most of the time though (the receiver/STB can deal with a
> loss of signal by muting the audio and freezing the last complete
> picture until the signal is restored, for example).

The the comment of Giovanni concerning this.


>>But the discussion is all pretty academic. 30, 40 or even 50 KBps is way
>>to few for a TV signal and anywhere near "viewable for more then 30
>>seconds".
> Another option would be to provide continuous audio and "slide show"
> video (new pictures no more often than every 1/2 second, for example).

I don't really understand.

Apparently, you are not talking about a system to replace current "normal"
NTSC television are you. Otherwize, who would accept to have het current
NTSC -even if it is with a lot of noice and interference- with something
that gives 2 frames a second on a small screen).

Are you talking about an "emergency" TV system here?


>>> No, it'd be LDTV, sort of a "lifeline" OTA TV service for people who
>>> don't have ATSC DTV/HDTV or cable or satellite systems.
>>Hmm. In what senario do people not have access to either OTA or
>>satellite?

> In the USA, the government wants the OTA NTSC transmitters turned of as
> soon as possible ...

OK, but as it will be replaced by OTA ATSC. I am sorry but I do not really
see the problem at all.


> My proposal would be low cost option for people can't or won't get an
> ATSC DTV/HDTV receiver (and antenna).

Actually, the plan does that -in the end- every TV will have a ATSC
decoder in it, isn't it? Just like current TV-sets have a NTSC decoder in
them.
So, what exactly is the problem?


> Kirk Bayne
Cheerio! Kr. Bonne.
--
Kristoff Bonne, Bredene, BEL
H323 VoIP: callto://krbonne.homelinux.net/
[nl] [fr] [en] [de]
Anonymous
April 22, 2004 1:01:06 AM

Archived from groups: alt.video.digital-tv (More info?)

Gegroet,

Op Woe, 21 Apr 2004 16:18:47 +0000, schreef 21C BBS:
>>> STBs using hardware RealPlayer decoders shouldn't be very
>>> expensive (probably much less expensive than ATSC DTV/HDTV STBs).

>> But people will still be forced to go out a buy new equipment, if
>> you're going to do that then why not just buy a proper ATSC box? The
>> cost of most kit comes down to distribution, marketting and packaging
>> costs rather than their contents.

> Agreed, however the thread lives on.

Amen to that!


Cheerio! Kr. Bonne.
--
Kristoff Bonne, Bredene, BEL
H323 VoIP: callto://krbonne.homelinux.net/
[nl] [fr] [en] [de]
Anonymous
April 22, 2004 1:14:59 AM

Archived from groups: alt.video.digital-tv (More info?)

"K. B." <hotmail.com@lis2lis2> wrote in message
news:40836478.2628963@netnews.worldnet.att.net...
> My idea for providing the "15%" in the USA with some sort of OTA
> TV after the NTSC OTA TV signals are turned off:
>
> Use the RealPlayer codec (for example) and a regular AM radio
> transmitter to provide digital LDTV.
>
> AM radio has been in use for over 80 years and the types of
> channel impairments in the AM band should be well documented, so
> finding a suitable error correction scheme should be fairly easy.

The answer is that the pictures would be pretty bad. Even with my broadband
connection, with data at 226 kbps (RealAudio streaming video), which is
about five times the bitrate possible on an AM BCB carrier, TV pictures are
barely worth watching at postcard size. Such "TV reception" as is delivered
by computer is just a novelty, suitable for footage of an explosion in a
fireworks factory or Paris Hilton doing her impression of the Incredible
Hulk. (It's a "green" joke. Get it?) Anyhow, a worthwhile TV picture
needs several hundred kbps. VTC's use 384 kbps to give you a "watchable
presentation" of some guy in Tokyo you never met. Asking some farm family
to watch "American Idol" at 384 kbps would constitute cruel and unusual
punishment. They'd be trading a cow to the dish guy first thing in the
morning.

Whether some codec will ever be developed to produce a decent TV picture at
a 50-100 kbps data rate is speculative at best. It's not here, it's not
right now.
Anonymous
April 22, 2004 5:02:30 AM

Archived from groups: alt.video.digital-tv (More info?)

K. B. wrote:
> On Mon, 19 Apr 2004 22:38:02 +0200, Kristoff Bonne
> <kristoff.bonne@compaqnet.nospam.be> posted:
>
>> Now, you propose to put a TV-channel (video and audio) plus the
>> original AM radio-station into 30 to 40 Kbps?
>
> My proposal would be a substitute for the AM radio audio, anyone
> tuning a regular AM radio to the station would hear noise
> (similar to the noise on a voice telephone line when using a
> modem).
>
> I typically get about 50kbps with my dial-up connection (IIRC,
> home telephone voice line bandwidth is about 4kHz) and RealPlayer
> works OK (although the variable latency of the Internet causes
> problems).

Aaah - but don't 56kbps Modems exploit some cleverness based on the near
universal use of 64kbps digital kit at the exchange to get that rate over
the voice channel? (ISTR that 8bit 8Khz sampling is used for most voice
telephony in digital exchanges and the various V... 56k modem standards
exploit this) These modems also use some form of training with the remote
digital modem at the ISP etc. to allow the circuit to be analysed etc.,
exploiting the 1:1 nature of a modem link?

Can you compare an AM radio circuit, which is 1:many and can't be optimised
on a per-user basis in the same way?

>
> AM radio typically offers a bandwidth of about 5kHz.

But does it compare directly with a 4KHz voice circuit running into a
digital telephone exchange ?

You may find the real limits to data carriage over the channel are a bit
lower than 50kbps...

Steve
Anonymous
April 22, 2004 9:53:01 AM

Archived from groups: alt.video.digital-tv (More info?)

On Wed, 21 Apr 2004 12:24:38 +0200, Giovanni Landman
<gio@wanadoo.dutch.invalid> posted:

>On Wed, 21 Apr 2004 08:34:35 GMT, K. B. wrote:
>
>> On Wed, 21 Apr 2004 09:56:54 +0200, Kristoff Bonne
>> <kristoff.bonne@compaqnet.nospam.be> posted:
>>
>>>As a one-way network needs a forward error-correction mechanism, you loose
>>>somewhere between one thirth and half of you throughput only for that!
>>
>> It doesn't have to be (near) perfect data transmission, it should
>> work most of the time though (the receiver/STB can deal with a
>> loss of signal by muting the audio and freezing the last complete
>> picture until the signal is restored, for example).
>
>Well, that type of QoS is not very good, isn't it?
>I think it's way below the limit of what is considered acceptable for
>broadcast.

Regarding Quality of Service:
I'm in the Kansas City metro area and our 3 VHF TV stations
transmit at their full allowed power. Up until about 10 years
ago, I used the VHF "rabbit ears" that came with my TV and I put
up with quite a lot of picture interference (just "sparkles", the
picture didn't roll and there weren't a lot of ghosts) in
channels 4 and 5 because I wanted to watch TV shows for "free".

My point is, if a person is parsimonious, QoS can be fairly low.

My proposal is for people who have a choice of no OTA TV or AM
radio digital LDTV.

Kirk Bayne
alt.video.digital-tv Home Page
<http://www.geocities.com/lislislislis/avdtv.htm&gt;
Anonymous
April 22, 2004 10:07:59 AM

Archived from groups: alt.video.digital-tv (More info?)

On Wed, 21 Apr 2004 18:56:41 +0200, Kristoff Bonne
<kristoff.bonne@compaqnet.nospam.be> posted:

>> Another option would be to provide continuous audio and "slide show"
>> video (new pictures no more often than every 1/2 second, for example).
>
>I don't really understand.
>
>Apparently, you are not talking about a system to replace current "normal"
>NTSC television are you.

Correct.

>Are you talking about an "emergency" TV system here?

AM radio digital LDTV or nothing would be the worst case.

>> In the USA, the government wants the OTA NTSC transmitters turned of as
>> soon as possible ...
>
>OK, but as it will be replaced by OTA ATSC. I am sorry but I do not really
>see the problem at all.

>> My proposal would be low cost option for people can't or won't get an
>> ATSC DTV/HDTV receiver (and antenna).
>
>Actually, the plan does that -in the end- every TV will have a ATSC
>decoder in it, isn't it? Just like current TV-sets have a NTSC decoder in
>them.
>So, what exactly is the problem?

If the local OTA TV broadcasters could be carried on
cable/satellite systems without an OTA signal, they would
probably turn off their OTA signal(s) (NTSC, ATSC).

In the worst case, there would be no NTSC or ATSC OTA signals, AM
radio digital LDTV would be the only OTA TV type signal (for
people who don't have cable or satellite).

Kirk Bayne
alt.video.digital-tv Home Page
<http://www.geocities.com/lislislislis/avdtv.htm&gt;
Anonymous
April 22, 2004 11:25:30 AM

Archived from groups: alt.video.digital-tv (More info?)

On Thu, 22 Apr 2004 01:02:30 +0100, "Stephen Neal"
<stephen.neal@nospam.please.as-directed.com> posted:

>Can you compare an AM radio circuit, which is 1:many and can't be optimised
>on a per-user basis in the same way?

The error correction in the data stream would have to be designed
to deal with as many types of AM signal degradation as possible.

>You may find the real limits to data carriage over the channel are a bit
>lower than 50kbps...

Still, even if the actual data rate was 25Kbps after error
correction (for example), it'd be possible to provide continuous
speech grade audio
<http://www.codingtechnologies.com/products/aacPlus.htm&...;
and have about 51K bits for a new picture every 3 seconds.

Kirk Bayne
alt.video.digital-tv Home Page
<http://www.geocities.com/lislislislis/avdtv.htm&gt;
Anonymous
April 22, 2004 3:14:58 PM

Archived from groups: alt.video.digital-tv (More info?)

Gegroet,

Op Do, 22 Apr 2004 07:25:30 +0000, schreef K. B.:
>>You may find the real limits to data carriage over the channel are a bit
>>lower than 50kbps...

> Still, even if the actual data rate was 25Kbps after error
> correction (for example), it'd be possible to provide continuous
> speech grade audio
> <http://www.codingtechnologies.com/products/aacPlus.htm&...;
> and have about 51K bits for a new picture every 3 seconds.

In short, a MOT slideshow on top of DRM.

It exists and it is done! See
http://www.owdjim.gen.nz/chris/radio/DRM/DRM.html


> Kirk Bayne
Cheerio! Kr. Bonne.
--
Kristoff Bonne, Bredene, BEL
H323 VoIP: callto://krbonne.homelinux.net/
[nl] [fr] [en] [de]
Anonymous
April 22, 2004 5:05:19 PM

Archived from groups: alt.video.digital-tv (More info?)

On Thu, 22 Apr 2004 05:53:01 GMT, K. B. wrote:

> On Wed, 21 Apr 2004 12:24:38 +0200, Giovanni Landman
> <gio@wanadoo.dutch.invalid> posted:
>
>>On Wed, 21 Apr 2004 08:34:35 GMT, K. B. wrote:
>>
>>> On Wed, 21 Apr 2004 09:56:54 +0200, Kristoff Bonne
>>> <kristoff.bonne@compaqnet.nospam.be> posted:
>>>
>>>>As a one-way network needs a forward error-correction mechanism, you loose
>>>>somewhere between one thirth and half of you throughput only for that!
>>>
>>> It doesn't have to be (near) perfect data transmission, it should
>>> work most of the time though (the receiver/STB can deal with a
>>> loss of signal by muting the audio and freezing the last complete
>>> picture until the signal is restored, for example).
>>
>>Well, that type of QoS is not very good, isn't it?
>>I think it's way below the limit of what is considered acceptable for
>>broadcast.
>
> Regarding Quality of Service:
> I'm in the Kansas City metro area and our 3 VHF TV stations
> transmit at their full allowed power. Up until about 10 years
> ago, I used the VHF "rabbit ears" that came with my TV and I put
> up with quite a lot of picture interference (just "sparkles", the
> picture didn't roll and there weren't a lot of ghosts) in
> channels 4 and 5 because I wanted to watch TV shows for "free".
>
> My point is, if a person is parsimonious, QoS can be fairly low.

Agreed, if it only isn't too low.
The scheme you described above did not exactly give me much hope.
But then again, OK.

--

mvg,
Giovanni.
April 22, 2004 5:58:23 PM

Archived from groups: alt.video.digital-tv (More info?)

"Stephen Neal" <stephen.neal@nospam.please.as-directed.com> wrote in message
<
> > I typically get about 50kbps with my dial-up connection (IIRC,
> > home telephone voice line bandwidth is about 4kHz) and RealPlayer
> > works OK (although the variable latency of the Internet causes
> > problems).
>
> Aaah - but don't 56kbps Modems exploit some cleverness based on the near
> universal use of 64kbps digital kit at the exchange to get that rate over
> the voice channel? (ISTR that 8bit 8Khz sampling is used for most voice
> telephony in digital exchanges and the various V... 56k modem standards
> exploit this) These modems also use some form of training with the remote
> digital modem at the ISP etc. to allow the circuit to be analysed etc.,
> exploiting the 1:1 nature of a modem link?
>
> Can you compare an AM radio circuit, which is 1:many and can't be
optimised
> on a per-user basis in the same way?

No, any terrestrial carrier, especially operating in the LW/MW frequency
ranges, has to deal with entropy not seen even on the most nastiest of POTS
lines.

The DRM (www.drm.org) people have been working on this for years and have
developed a very elegant and efficient system along with most of the most
refined codecs combined with SBR, (i.e. AAC+).

I can't see many people upping this with some tinkering combined with Real
Audio, it would sound as bad as IBOC in the AM ranges... if that's possible.

Az.
April 22, 2004 5:59:34 PM

Archived from groups: alt.video.digital-tv (More info?)

"Kristoff Bonne" <kristoff.bonne@compaqnet.nospam.be> wrote in message
news:p an.2004.04.22.09.14.57.742013@compaqnet.nospam.be...
> Gegroet,
>
> Op Do, 22 Apr 2004 07:25:30 +0000, schreef K. B.:
> >>You may find the real limits to data carriage over the channel are a bit
> >>lower than 50kbps...
>
> > Still, even if the actual data rate was 25Kbps after error
> > correction (for example), it'd be possible to provide continuous
> > speech grade audio
> > <http://www.codingtechnologies.com/products/aacPlus.htm&...;
> > and have about 51K bits for a new picture every 3 seconds.
>
> In short, a MOT slideshow on top of DRM.
>
> It exists and it is done! See
> http://www.owdjim.gen.nz/chris/radio/DRM/DRM.html

Which is a very nice advance on shortwave radio... it's not intended as a TV
replacement service.

Az.
Anonymous
April 23, 2004 1:07:07 AM

Archived from groups: alt.video.digital-tv (More info?)

Gegroet,

Op Do, 22 Apr 2004 06:07:59 +0000, schreef K. B.:
>>Are you talking about an "emergency" TV system here?

> AM radio digital LDTV or nothing would be the worst case.

Well, appart from the technical feasability, you are also forgetting two
other things:

- One of the basic elements of emergency equipement is that is needs to be
as simple as possible. The less components it has, the less components can
break.

For that, I think radio is a much better sollution. Both in aspect of the
transmission equipement, the transmission "channel" and receiver
equipement (including elements like powerconsumption, etc.), a radio is
much more robust a TV.

- If you are talking about emergency equipement for large-scale usage of
"joe public", it needs to be something the people use everythey.
If would have a box they only need "in case of emergencies", it will just
end up in the closet or in the attick, and when people really need it,
most people would probably not remember "where the hell they put it",
would come to the conclussion that -either- they have used the batteries
in it for something else, or that the batteries are competely dead.


So, in the end, you need a system which is actually used by people every
day; and something that just gives a 2 frames a second slideshow is
(IMHO) not really what people are waiting for.



> Kirk Bayne
Cheerio! Kr Bonne.
--
Kristoff Bonne, Bredene, BEL
H323 VoIP: callto://krbonne.homelinux.net/
[nl] [fr] [en] [de]
Anonymous
April 23, 2004 9:07:43 AM

Archived from groups: alt.video.digital-tv (More info?)

On Thu, 22 Apr 2004 21:07:07 +0200, Kristoff Bonne
<kristoff.bonne@compaqnet.nospam.be> posted:

>So, in the end, you need a system which is actually used by people every
>day; and something that just gives a 2 frames a second slideshow is
>(IMHO) not really what people are waiting for.

Perhaps "emergency TV" isn't the right way to describe my
proposal.

If, as I postulated, the local OTA TV broadcasters find a way to
be carried on the local cable system(s) (or as a local channel on
a satellite system) without actually transmitting an ATSC or NTSC
OTA signal, they'll probably turn off their OTA signal(s).

Putting some of the local TV content on an AM radio digital LDTV
station would allow people who don't have cable or satellite TV
(maybe they can't afford it) to get something resembling TV by
just getting a low cost STB to use with their existing NTSC TV.

Kirk Bayne
alt.video.digital-tv Home Page
<http://www.geocities.com/lislislislis/avdtv.htm&gt;
Anonymous
April 23, 2004 1:44:49 PM

Archived from groups: alt.video.digital-tv (More info?)

Greetings,

Op Vr, 23 Apr 2004 05:07:43 +0000, schreef K. B.:
>>So, in the end, you need a system which is actually used by people every
>>day; and something that just gives a 2 frames a second slideshow is
>>(IMHO) not really what people are waiting for.

> Perhaps "emergency TV" isn't the right way to describe my
> proposal.
> If, as I postulated, the local OTA TV broadcasters find a way to
> be carried on the local cable system(s) (or as a local channel on
> a satellite system) without actually transmitting an ATSC or NTSC
> OTA signal, they'll probably turn off their OTA signal(s).
> Putting some of the local TV content on an AM radio digital LDTV
> station would allow people who don't have cable or satellite TV
> (maybe they can't afford it) to get something resembling TV by
> just getting a low cost STB to use with their existing NTSC TV.

It looks like you're just trying to find a way to rid TV broadcasters of
their obligation to broadcast OTA.

To me, this sounds like you are proposing a major change in the 'public
service' nature of broadcasting.
IMHO, this is more a question for a political discussion in parliament
then here in this NG. ;-)


> Kirk Bayne
Cheerio! Kr. Bonne.
--
Kristoff Bonne, Bredene, BEL
H323 VoIP: callto://krbonne.homelinux.net/
[nl] [fr] [en] [de]
Anonymous
April 23, 2004 1:44:50 PM

Archived from groups: alt.video.digital-tv (More info?)

On Fri, 23 Apr 2004 09:44:49 +0200, Kristoff Bonne
<compaqnet.be@kristoff.bonne> posted:

>It looks like you're just trying to find a way to rid TV broadcasters of
>their obligation to broadcast OTA.

Most people in the USA watch their local OTA TV stations on
cable, the only thing the OTA signal does is sometimes leak into
the cable system and interfere with some cable channels.

>To me, this sounds like you are proposing a major change in the 'public
>service' nature of broadcasting.

I think that's what Disney (ABC), Viacom (CBS,UPN), Newscorp
(FOX), GE (NBC) and Time Warner (WB) would like, they want to
present their content with advertisements to likely buyers at the
lowest possible cost.

Providing an OTA TV signal is an added expense that may not be
economical because the OTA TV viewers may not be affluent.

Kirk Bayne
alt.video.digital-tv Home Page
<http://www.geocities.com/lislislislis/avdtv.htm&gt;
April 23, 2004 7:48:10 PM

Archived from groups: alt.video.digital-tv (More info?)

"K. B." <hotmail.com@lis2lis2> wrote in message
news:40889e8c.697611@netnews.worldnet.att.net...
> On Thu, 22 Apr 2004 21:07:07 +0200, Kristoff Bonne
> <kristoff.bonne@compaqnet.nospam.be> posted:
>
> >So, in the end, you need a system which is actually used by people every
> >day; and something that just gives a 2 frames a second slideshow is
> >(IMHO) not really what people are waiting for.
>
> Perhaps "emergency TV" isn't the right way to describe my
> proposal.
>
> If, as I postulated, the local OTA TV broadcasters find a way to
> be carried on the local cable system(s) (or as a local channel on
> a satellite system) without actually transmitting an ATSC or NTSC
> OTA signal, they'll probably turn off their OTA signal(s).
>
> Putting some of the local TV content on an AM radio digital LDTV
> station would allow people who don't have cable or satellite TV
> (maybe they can't afford it) to get something resembling TV

If that's really the case then maybe government and broadcasters have a case
to answer, especially if the Treasury stands to gain so much by clearing the
spectrum. Your concept seems quite patronising, if they want a OTA
replacement service then they need an ATSC box the same as everyone else,
not some substandard proxy, this could be sweetened by incentives if the
market hasn't levelled by then, as per Berlin.

Az.
Anonymous
April 23, 2004 11:48:07 PM

Archived from groups: alt.video.digital-tv (More info?)

Gegroet,

Op Vr, 23 Apr 2004 08:34:44 +0000, schreef K. B.:
>>It looks like you're just trying to find a way to rid TV broadcasters of
>>their obligation to broadcast OTA.
> Most people in the USA watch their local OTA TV stations on
> cable, the only thing the OTA signal does is sometimes leak into
> the cable system and interfere with some cable channels.
(...)
> Providing an OTA TV signal is an added expense that may not be
> economical because the OTA TV viewers may not be affluent.

Well, I understand that you might have some argument for this; but again,
you would change the basic idea of broadcasting being a mainly "public"
service; with cable or satellite just being an additional service that
provides additional channels or a better image-quality.


A descision like that would -IMHO- merrit a public debate (i.e. in
parliament).


> Kirk Bayne
Cheerio! Kr. Bonne.
--
Kristoff Bonne, Bredene, BEL
H323 VoIP: callto://krbonne.homelinux.net/
[nl] [fr] [en] [de]
Anonymous
April 24, 2004 4:55:36 AM

Archived from groups: alt.video.digital-tv (More info?)

On Fri, 23 Apr 2004 15:48:10 GMT, "Aztech" <az@tech.com> posted:

>"K. B." <hotmail.com@lis2lis2> wrote in message
>> Putting some of the local TV content on an AM radio digital LDTV
>> station would allow people who don't have cable or satellite TV
>> (maybe they can't afford it) to get something resembling TV
>
>Your concept seems quite patronising, if they want a OTA
>replacement service then they need an ATSC box the same as everyone else,
>not some substandard proxy, this could be sweetened by incentives if the
>market hasn't levelled by then, as per Berlin.

I was thinking of a situation where all of the terrestrial "TV"
spectrum had been auctioned off (no NTSC or ATSC broadcasts).

AFAIK, nobody wants to auction off the about 1MHz AM radio band,
so an AM radio station used for digital LDTV seems "safe".

Also, regarding digital signals in the AM radio band, AM IBOC is
only approved for daytime use whereas my proposal would have no
such restriction.

Kirk Bayne
alt.video.digital-tv Home Page
<http://www.geocities.com/lislislislis/avdtv.htm&gt;
!