Spectrum plot of an IBOC AM station

Spectrum plot of an IBOC AM station

Post by Peter Mau » Fri, 27 Feb 2004 05:20:39



> [...]

>>Well, maybe, but I don't see the entire broadcast industry rushing to
>>IBOC.  The night time ban puts a big crimp on IBOC.  IBOC reduces the
>>bandwidth and fidelity of the main channel.  Also, putting all that
>>power into sideband noise reduces the power and signal to noise ratio of
>>the main channel.  People who are annoyed by bad sounding AM radio and
>>have yet to buy an IBOC radio are more likely to tune out.

>>People who don't much care about fidelity, and I think that's the
>>majority of casual listeners, won't much care for IBOC, either.

>>Frank Dresser

> All very true. But the owners of the media monopolies don't care a
> great deal about the success of IBOC or even its widespread
> implementation. Their main concern is to _prevent_ the creation of a
> new digital band wherein all existing broadcasters would have an
> even playing field. IBOC does that -- at least so far.

> With every good wish,

> Kevin.

   It's actually more insidious than that.

   A little background.

   Meetings I attended when I worked at CBS discussed the future of
radio, and for that matter, TV broadcasting revenues, and it was
clear that advertising revenue streams were not the future.
Technological innovations, at that time limited to VCR's with black
sensing self editing capability which allowed automatic deletion of
commercials, and later the first generation of TiVo which openly
promoted commercial free TV viewing, made it clear that advertising
revenues were under extreme fire. Though Radio lagged behind TV in
this capability, it was only a matter of time before radio caught
up, and radio advertising revenues, too, were threatened.

   Karmazin said at one staff breakfast that I atteneded, that the
only way to insure the long term viability of broadcast media was
through the generation of multiple revenue streams for each freqency
allocation. He described several ways that advertising could be
sold, and incorporated into the programming so that additional
non-traditional revenue could be harvested outside of spot sales.
Other products could be tied to each broadcast facility generating
further non-traditional revenue.  This is where the ubiquitous
"Dateline" your favorite radio station promotes.  That software was
invented by three guys at Northwestern in Evanston. We turned into
the Dateline at US99, and my GM created the company, DMI, which was
later spun off into Spark International, which installs, maintains
and operates the datelines worldwide.

   But non traditional revenue sources all require some form of
advertising to work.

   Karmazin was looking for more direct revenue streams, not based
in advertising. And when he got to digital broadcasting, he outlined
several future scenarios...all of which involve stealing small
amounts of bandwidth from the digital stream, which would be
converted to alternative programming, or informational streams. He
actually said the words....that we will not be broadcasting full
bandwidth digital programming beyond the resolution we currently
enjoy in analog, in fact, maybe even a little less, so that
alternative revenue producing streams can be incorporated onto each
frequency.  Not unlike SAP channels do now for television. These
would also be subscription based, further generating addtional revenue.

   This would be necessary because of the erosion of advertising
revenue caused by both technological innovation, and the public's
growing distaste for the spot load.

   He then cited cable tv and it's subscription based business model
as an example of how the future of broadcasting may be shaped.
Noting the pervasive nature of cable, and the spread of subscription
based dish networks, he said there is clearly no major objection to
subscription based broadcasting among the population.  And as the XM
and Sirius models clearly demonstrate, subscription based reception
for radio is a viable business model.

   Karmazin said that the real benefit of digital broadcasting,
whether DAB, or IBOC, because of the interactive potential of
digital distribution, as currently demonstrated with digital cable,
  will be the capture of the holy grail of broadcasting since the
media were first blown into the air--absolutely accurate counts of
who's listening, and when.

   It will also mean the ultimate in usage sensitive pricing....

   Subscription radio.

   When asked if this was his goal, he said not at first.  But
eventually, yes.

   There followed a lot of mumbling in the room.

   Now, whether IBOC, especially on AM, proves itself as a
practicality before something else comes along to obsolete it will
be determined in the next few years. XM growth, and expansion of
accessibility, demonstrates it to be a viable contender on the
horizon. And the availability of internet radio through cell phones
and PDA's is proving to be a surprise, although certainly not a
current threat.  In the meantime, the larger broadcasters retain
their investment, their profitability, and their competitive
advantages of both scale and strategy over smaller operators. While
preparing to take full advantage of all the media at their disposal.

   Something that smaller operators will have to struggle to achieve.

   But the ultimate losers with IBOC will not be the smaller
operators.

   The ultimate loss will be on our side of the grille cloth.

 
 
 

Spectrum plot of an IBOC AM station

Post by Frank Dresse » Fri, 27 Feb 2004 06:51:56



[snip]

Quote:>    Karmazin said that the real benefit of digital broadcasting,
> whether DAB, or IBOC, because of the interactive potential of
> digital distribution, as currently demonstrated with digital cable,
>   will be the capture of the holy grail of broadcasting since the
> media were first blown into the air--absolutely accurate counts of
> who's listening, and when.

I can imagine how they might get a sense of which radios are tuned to
which program.  But how can they know who, if anyone, is listening?

Quote:

>    It will also mean the ultimate in usage sensitive pricing....

>    Subscription radio.

>    When asked if this was his goal, he said not at first.  But
> eventually, yes.

>    There followed a lot of mumbling in the room.

>    Now, whether IBOC, especially on AM, proves itself as a
> practicality before something else comes along to obsolete it will
> be determined in the next few years. XM growth, and expansion of
> accessibility, demonstrates it to be a viable contender on the
> horizon. And the availability of internet radio through cell phones
> and PDA's is proving to be a surprise, although certainly not a
> current threat.  In the meantime, the larger broadcasters retain
> their investment, their profitability, and their competitive
> advantages of both scale and strategy over smaller operators. While
> preparing to take full advantage of all the media at their disposal.

Of course, free radio has a competitive advantage over pay radio.  It
would be up to the networks to somehow come up with programming people
will pay for.  Anyway, pay programming now seems to be low cost.  No
multimilllion talk show hosts and such.

Quote:

>    Something that smaller operators will have to struggle to achieve.

>    But the ultimate losers with IBOC will not be the smaller
> operators.

>    The ultimate loss will be on our side of the grille cloth.

It might, but the loss would depend on the number of people willing to
pay for radio.  There's a hard core who won't pay for cable, and I'd
guess the hard core who won't pay for radio is even larger.

Frank Dresser

 
 
 

Spectrum plot of an IBOC AM station

Post by RH » Fri, 27 Feb 2004 16:36:36




> > > It's just a noise rush, but not white exactly.  The giveaway is that
>  it's on
> > > only one sideband of the station you're trying to hear.  If you hear
>  it on the
> > > LSB, the offending IBOC station is 10 kHz higher (not lower as you'd
>  expect);
> > > and if on USB, then 10 kHz lower.

> > I'm not sure I understand.  The spectrum plot shows two symmetrical
> > peaks off the carrier frequency.  The noise I observed was consistant
> > with that.

> It's not symmetric around the adjacent channel station being interfered with.

> If IBOC is on 700 and you're listening to 710, the the IBOC noise is at 713,
> which is the upper sideband of 710.  If you listen to 710 LSB, the noise
> disappears.

.

RH,

I thought that basic AM and SSB technology were different from IBOC
Digital Technology.


IBOC and SSB are not produced in the same manner and do not decipher
in the same manner.

Please Correct Me - If I Am Wrong ?

~ RHF

.

 
 
 

Spectrum plot of an IBOC AM station

Post by Frank Dresse » Fri, 27 Feb 2004 20:44:35


> > If IBOC is on 700 and you're listening to 710, the the IBOC noise is
at 713,
> > which is the upper sideband of 710.  If you listen to 710 LSB, the
noise
> > disappears.

> .

> RH,

> I thought that basic AM and SSB technology were different from IBOC
> Digital Technology.



> IBOC and SSB are not produced in the same manner and do not decipher
> in the same manner.

> Please Correct Me - If I Am Wrong ?

> ~ RHF

> .

I don't think Ron's is using SSB in the sense of a modulation method,
but rather as a reception method.  There's a couple of  troughs in the
spectrum plot in the splits between the main analog channel and the
digital sidebands.  One sideband of each adjacent channel will be in
those troughs.

http://earthsignals.com/add_CGC/KMXE.PDF

Listening SSB mode will limit the interference.  Unfortunately, the
sideband with the least amount of interference will be the sideband
closest to the carrier of the unwanted station.  Normally, it would be
preferable to listen to the sideband farthest away from the carrier of
the unwanted station.

I was able to tune in an actual IBOC transmission on WSAI 1530 kHz,
yesterday evening.  WSAI is strong here, but I've never tuned them in
before they turned off their IBOC noisemaker.  I was also able to tune
in KXEL 1540kHz  inbetween WSAI's main channel and their upper IBOC
noiseband.  There was splatter from the main channel and noise from the
digital channel, but it was readable.  I don't have the selectivity to
listen in true sideband mode, but I think even that wouldn't totally
eliminate the interference.  If the IBOC station is local, I think there
would still enough noise and splatter to overwhelm an otherwise
listenable near adjacent channel.

The current split digital/analog system is intended to be temporary.
The IBOC standard is designed to go full digital.

Frank Dresser

 
 
 

Spectrum plot of an IBOC AM station

Post by Davi » Sat, 28 Feb 2004 01:53:15

That makes no sense.  Xm and Sirius each have 100 channels on 12.5 MHz
of spectrum.  The current FM and AM bands have 21.4 mHz of spectrum.
They could migrate everyone to a new band then auction off the old  FM
channels for a billion dollars.

On Wed, 25 Feb 2004 19:49:19 GMT, "Frank Dresser"




>> All very true. But the owners of the media monopolies don't care a
>> great deal about the success of IBOC or even its widespread
>> implementation. Their main concern is to _prevent_ the creation of a
>> new digital band wherein all existing broadcasters would have an
>> even playing field. IBOC does that -- at least so far.

>> With every good wish,

>> Kevin.

>We don't have a seperate band for digital radio, but the time brokered
>domestic shortwave stations are allowing much of the programming the
>networks don't.  Although there isn't any local content.  Anyway, the
>radio establishment doesn't seem much bothered by independant
>broadcasting.

>I think the bigger reason there wasn't a seperate digital band
>established is the government plans to auction off spectrum, and setting
>aside a band in a prime VHF/UHF region puts a crimp in their budget
>estimates.

>Frank Dresser

 
 
 

Spectrum plot of an IBOC AM station

Post by Frank Dresse » Sat, 28 Feb 2004 02:17:23


Quote:> That makes no sense.  Xm and Sirius each have 100 channels on 12.5 MHz
> of spectrum.  The current FM and AM bands have 21.4 mHz of spectrum.
> They could migrate everyone to a new band then auction off the old  FM
> channels for a billion dollars.

This is your lucky year.  You can run for President!  Run on the "I'll
make you replace your radios" platform.  Don't forget to do all your
campaigning from the sattelite.

Dunno about the billion bucks, though.  I suppose that's good for the
government budget estimate, but reality may be different.

Frank Dresser

 
 
 

Spectrum plot of an IBOC AM station

Post by RH » Sat, 28 Feb 2004 03:38:15




> > > If IBOC is on 700 and you're listening to 710, the the IBOC noise is
>  at 713,
> > > which is the upper sideband of 710.  If you listen to 710 LSB, the
>  noise
> > > disappears.

> > .

> > RH,

> > I thought that basic AM and SSB technology were different from IBOC
> > Digital Technology.



> > IBOC and SSB are not produced in the same manner and do not decipher
> > in the same manner.

> > Please Correct Me - If I Am Wrong ?

> > ~ RHF

> > .

> I don't think Ron's is using SSB in the sense of a modulation method,
> but rather as a reception method.  There's a couple of  troughs in the
> spectrum plot in the splits between the main analog channel and the
> digital sidebands.  One sideband of each adjacent channel will be in
> those troughs.

> http://earthsignals.com/add_CGC/KMXE.PDF

> Listening SSB mode will limit the interference.  Unfortunately, the
> sideband with the least amount of interference will be the sideband
> closest to the carrier of the unwanted station.  Normally, it would be
> preferable to listen to the sideband farthest away from the carrier of
> the unwanted station.

> I was able to tune in an actual IBOC transmission on WSAI 1530 kHz,
> yesterday evening.  WSAI is strong here, but I've never tuned them in
> before they turned off their IBOC noisemaker.  I was also able to tune
> in KXEL 1540kHz  inbetween WSAI's main channel and their upper IBOC
> noiseband.  There was splatter from the main channel and noise from the  
> digital channel, but it was readable.  I don't have the selectivity to
> listen in true sideband mode, but I think even that wouldn't totally
> eliminate the interference.  If the IBOC station is local, I think there
> would still enough noise and splatter to overwhelm an otherwise
> listenable near adjacent channel.

> The current split digital/analog system is intended to be temporary.
> The IBOC standard is designed to go full digital.

> Frank Dresser

.  

FD,

If the IBOC Signal is a 'broadcast' as "Digital Encoded Algorithm".
Either as Dual IBOC Signals (Stereo) or as 'separate' Voice
and Data/Information Channels.

Then, how do you 'decode' it and Listen to it simply using
standard "Analog" SSB ?

~ RHF

.

 
 
 

Spectrum plot of an IBOC AM station

Post by Frank Dresse » Sat, 28 Feb 2004 04:19:47


Quote:> .

> FD,

> If the IBOC Signal is a 'broadcast' as "Digital Encoded Algorithm".
> Either as Dual IBOC Signals (Stereo) or as 'separate' Voice
> and Data/Information Channels.

> Then, how do you 'decode' it and Listen to it simply using
> standard "Analog" SSB ?

> ~ RHF

> .

I didn't take it as a method of decoding the IBOC signal.  I took to
mean a way to minimize the interference from a IBOC station on a close
adjacent channel signal.

Let's say a station at 830 kHz is using IBOC and you want to hear a
station on 840 kHz.  There's interference to the station at 840 from the
splatter of the main channel at 830 and the IBOC sideband centered at
843.  You can minimize the interference from the IBOC sideband if you
listen to the station at 840 in LSB mode.

http://earthsignals.com/add_CGC/KMXE.PDF

Of course, normally it's preferable to listen to that station at 840 kHz
in USB mode, but the IBOC sideband interferes heavily with that
sideband.

Frank Dresser

 
 
 

Spectrum plot of an IBOC AM station

Post by Brenda An » Sat, 28 Feb 2004 06:02:26




> > That makes no sense.  Xm and Sirius each have 100 channels on 12.5 MHz
> > of spectrum.  The current FM and AM bands have 21.4 mHz of spectrum.
> > They could migrate everyone to a new band then auction off the old  FM
> > channels for a billion dollars.

> This is your lucky year.  You can run for President!  Run on the "I'll
> make you replace your radios" platform.  Don't forget to do all your
> campaigning from the sattelite.

> Dunno about the billion bucks, though.  I suppose that's good for the
> government budget estimate, but reality may be different.

The thing is, as has been brought forward before, that the FM and VHF low
bands are not amenable to use by the people who are looking for those
high-bucks bands.. the necessary antennas are simply too large to use for
portable devices such as cellular or wireless internet services (yes, there
are indeed small FM radios with little or no antenna, but these are grossly
inefficient and require a very high signal level to work.. nor do they have

 
 
 

Spectrum plot of an IBOC AM station

Post by RH » Sat, 28 Feb 2004 10:01:36





> > .

> > FD,

> > If the IBOC Signal is a 'broadcast' as "Digital Encoded Algorithm".
> > Either as Dual IBOC Signals (Stereo) or as 'separate' Voice
> > and Data/Information Channels.

> > Then, how do you 'decode' it and Listen to it simply using
> > standard "Analog" SSB ?

> > ~ RHF

> > .

> I didn't take it as a method of decoding the IBOC signal.  I took to
> mean a way to minimize the interference from a IBOC station on a close
> adjacent channel signal.

> Let's say a station at 830 kHz is using IBOC and you want to hear a
> station on 840 kHz.  There's interference to the station at 840 from the
> splatter of the main channel at 830 and the IBOC sideband centered at
> 843.  You can minimize the interference from the IBOC sideband if you
> listen to the station at 840 in LSB mode.

> http://www.redwaveradio.com/

> Of course, normally it's preferable to listen to that station at 840 kHz
> in USB mode, but the IBOC sideband interferes heavily with that
> sideband.

> Frank Dresser

.

FD,

I can understand what you are saying, IF (Big 'if') I was trying
to get away from one interfering IBOC Side-Channel.  

***(Big 'butt' :o) What happens when there is 50% implementation
of IBOC and on average every other Channel is an IBOC Broadcaster
with an IBOC Side-Channel at both +15kHz and -15kHz.  

So now your Old Fashion AM Station at 840kHz has a 860kHz Lower
IBOC Side-Channel and also a 820kHz Upper IBOC Side-Channel;
both sitting within -&+ 5kHz of 840kHz.  

As, I read and interpret the Spectrogram the IBOC Signals are
about 12 dB above the band scan base noise level.  The Main
AM Signal is another 18 dB above the IBOC Side-Channels.  

While IBOC may be 'claimed' to be backwardly compatible with
the current AM Broadcast media.  It is apparent to me that with
may be 33% IBOC adoption the AM Band as we know it will cease
to be; and all remaining AM Band Broadcasters will be FORCE by
the 'new' IBOC Noise Levels to transition to IBOC or NOT Be Heard.

IBOC to IBOC will not be a problem because of the specific IBOC
Side-Channel Off-Set and the Encoding and Decoding of the IBOC
"Digital Algorithm".

***- To the old fashion AM Analog Radio Station the IBOC "Digital
Algorithms" from the upper and lower adjacent IBOC Side-Channels
will simply sound like NOISE "BIG TIME" !

Oh Well - I have rambled on long enough.

iboc ~ RHF
= = = I Be Overly Concerned !
.

 
 
 

Spectrum plot of an IBOC AM station

Post by Frank Dresse » Sat, 28 Feb 2004 13:47:20


Quote:

> FD,

> I can understand what you are saying, IF (Big 'if') I was trying
> to get away from one interfering IBOC Side-Channel.

> ***(Big 'butt' :o) What happens when there is 50% implementation
> of IBOC and on average every other Channel is an IBOC Broadcaster
> with an IBOC Side-Channel at both +15kHz and -15kHz.

> So now your Old Fashion AM Station at 840kHz has a 860kHz Lower
> IBOC Side-Channel and also a 820kHz Upper IBOC Side-Channel;
> both sitting within -&+ 5kHz of 840kHz.

This will have to make reception tough in the station's fringe areas.  I
don't know what area the FCC protects, but the figure of 700 miles for
the "clear channels" comes to mind.  It's unclear if there will be any
problem in each of the station's home cities.  But the NRSC (not the FCC
as I posted earlier) has stopped nighttime IBOC tests

Quote:

> As, I read and interpret the Spectrogram the IBOC Signals are
> about 12 dB above the band scan base noise level.  The Main
> AM Signal is another 18 dB above the IBOC Side-Channels.

> While IBOC may be 'claimed' to be backwardly compatible with
> the current AM Broadcast media.  It is apparent to me that with
> may be 33% IBOC adoption the AM Band as we know it will cease
> to be; and all remaining AM Band Broadcasters will be FORCE by
> the 'new' IBOC Noise Levels to transition to IBOC or NOT Be Heard.

Only if the interference effects radio stations in their home market.

Quote:

> IBOC to IBOC will not be a problem because of the specific IBOC
> Side-Channel Off-Set and the Encoding and Decoding of the IBOC
> "Digital Algorithm".

I don't know how well this system will perform, but I suspect the
digital sidebands will be interfering in areas where the received signal
isn't much stronger than the interfering signal.  That is, I don't think
digital will save digital from digital.

Quote:

> ***- To the old fashion AM Analog Radio Station the IBOC "Digital
> Algorithms" from the upper and lower adjacent IBOC Side-Channels
> will simply sound like NOISE "BIG TIME" !

And 95% of the listeners will never notice the interference.  But
there's no guarantee they will want the extra "features" digital radio
promises, especially if they have to pay extra for digital radios.

Quote:

> Oh Well - I have rambled on long enough.

> iboc ~ RHF
> = = = I Be Overly Concerned !
> .

http://www.redwaveradio.com/

Frank Dresser

 
 
 

Spectrum plot of an IBOC AM station

Post by Frank Dresse » Sun, 29 Feb 2004 05:16:21


> The thing is, as has been brought forward before, that the FM and VHF
low
> bands are not amenable to use by the people who are looking for those
> high-bucks bands.. the necessary antennas are simply too large to use
for
> portable devices such as cellular or wireless internet services (yes,
there
> are indeed small FM radios with little or no antenna, but these are
grossly
> inefficient and require a very high signal level to work.. nor do they
have

90MHz))

Yeah, let's wait 'till the VHF low band gets filled up before we
conclude there's a shortage of VHF bandwidth.

Frank Dresser

 
 
 

Spectrum plot of an IBOC AM station

Post by Frank Dresse » Tue, 02 Mar 2004 12:30:27


Quote:

> IBOC in the end has nothing to do with audio quality. If that really
was
> the point we might have had a chunk of spectrum for Digital Radio like
> the DTV transition for video. IBOC is about Digital Rights Management,
> enabling others to decide what you may or may not hear or, God Forbid,
> record.
> --
> chuck reti
> detroit mi

Others already decide what is broadcast, and I don't see how digital
modulation can keep anyone from recording audio.  Just what does IBOC
have to do with Digital Rights Management?

Frank Dresser

 
 
 

Spectrum plot of an IBOC AM station

Post by Chuck Ret » Fri, 05 Mar 2004 14:47:50

In article




> > IBOC in the end has nothing to do with audio quality. If that really
> was
> > the point we might have had a chunk of spectrum for Digital Radio like
> > the DTV transition for video. IBOC is about Digital Rights Management,
> > enabling others to decide what you may or may not hear or, God Forbid,
> > record.
> > --
> > chuck reti
> > detroit mi

> Others already decide what is broadcast, and I don't see how digital
> modulation can keep anyone from recording audio.  Just what does IBOC
> have to do with Digital Rights Management?

> Frank Dresser

I'm just pessimistic and cynical about the Brave New future of digital
broadcasting. IBOC as a "digital modulation" technique is not in itself
the evil (well, OK, it spews hash across the AM dial), but as a
transport for DRM-encoded digital content it may likely disable the
listener from doing what is considered fair use recording. I could see
the instance where one might not be able to "time shift" a program
without a subscription or use fee. For sure not in the immediate future,
but possible eventually.

chuck reti
detroit mi