The "FM" 'Band

[kfbkfb]

I propose a new (digital) terrestrial broadcast system:

This system would designed to be placed in the current
FM band in the currently unusable FM slots (due to a
local FM signal in a lower or higher slot or due to an
FM signal in a nearby, but different market).

This system would use the (practically ubiquitous -
ATSC 1.0 and DVDs) Dolby Digital (in 5.1 surround sound
mode) for the audio.

This system would use a low amplitude broadcast signal
with a great deal of error correction (the low amplitude
is to minimize possible interference WITH existing FM
signals and the error correction is to help deal with
the low amplitude and possible interference FROM existing
FM signals).

An OFDM based modulation system seems like a good place
to start.

Kirk Bayne

 

[TheBigA]

I propose a new (digital) terrestrial broadcast system:

Who are you "proposing" it to? The readers of a message group?

Do you understand how this process is done? It would need the approval of the federal government. The FCC is on record totally opposing a digital radio system of any sort. Are you willing to fund the lobbying expense to get them to approve your idea?

 

[seattlesarchiebunker]

The main thing to think about when discussing future digital radio standards is interactivity. It’ll be a tough road to hoe (and for people to even bother to purchase a new gadget) if “the next big thing” in broadcasting is less feature-rich than its streaming competitors.

Personally, I’m right there with you. The only way radio will remain a relevant broadcast medium 20 years or so from now will be doing something a bit different than the HD/Analog deal we have right now.

 

[PaulKTF]

Nah, we're good with what we have now (online streaming). This idea is about as bad as HD Radio or Satellite Radio.

 

[firepoint525]

Nothing happening as long as the government remains shut down.

 

[Ai4i]

I propose a new (digital) terrestrial broadcast system:

Comcast/Xfinity puts more than fifty Music Choice channels on one TV channel.
Ludwigent would like to do something similar, but on a broadcast TV channel

 

[TheBigA]

Ludwigent would like to do something similar, but on a broadcast TV channel

Your link says they want to put it on "digital" TV channels.

 

[Ai4i]

Your link says they want to put it on "digital" TV channels.

Right,
Pat Greenish wants to take one digital TV channel and divide it as such:
For example, 7.1, 7.2...7.49, 7.50 with only enough data to identify the composer,
performer, title, and maybe some background information or some of this.
Exactly the way CATV systems distribute premium music services, all within single digital TV channels.
It is a proven technology but would require the addition of some time and frequency redundancy.

 

[TheBigA]

It is a proven technology but would require the addition of some time and frequency redundancy.

But has no relevance to the FM Band, topic of this thread. The FCC said very clearly it didn't see doing to FM what it did to TV.

 

[Ai4i]

But has no relevance to the FM Band, topic of this thread.

I was simpling responding to kfbkfb's proposal with some pre-tested examples.

 

[kfbkfb]

Looks like the DRM+ system is almost there (suitable for unusable FM slots).
http://www.drm.org/drm/

Maybe a newly defined DRM++ system with special modulation specifically
designed to keep interference with existing FM signals to a minimum
(also interference with other DRM++ signals in the FM band).

Maybe the modulation could be configured be in the guardband area of
regular analog FM.

I'll contact the DRM group with my proposal/suggestion.

Kirk Bayne

 

[davideduardo]

Looks like the DRM+ system is almost there (suitable for unusable FM slots).
http://www.drm.org/drm/

Maybe a newly defined DRM++ system with special modulation specifically
designed to keep interference with existing FM signals to a minimum
(also interference with other DRM++ signals in the FM band).

Maybe the modulation could be configured be in the guardband area of
regular analog FM.

I'll contact the DRM group with my proposal/suggestion.

Kirk Bayne

DRM requires a separate frequency and transmitter. There is not enough space on AM or FM for DRM in the US. The system is not backwards compatible.

And nearly nobody will go out and buy a new "radio" today as they have the entertainment options they need on their smartphone and smartspeakers.

There is zero interest in this at the consumer and broadcaster level.

 

[davideduardo]

The main thing to think about when discussing future digital radio standards is interactivity. It’ll be a tough road to hoe (and for people to even bother to purchase a new gadget) if “the next big thing” in broadcasting is less feature-rich than its streaming competitors.

This is the key point when new transmission bands or systems are discussed. And the keyword is "interactivity".

 

[TheBigA]

The thing someone needs to invent is a digital transmission service that is receivable on existing FM receivers. My basic understanding of physics says it's impossible. But that's what people said to Tesla.

 

[spiritof67]

I have wondered if a system like RDS could be incorporated into car stereos/home units to switch between broadcast stations and internet streams. HD on AM doesn't have a good track record in terms of locking in a signal, and HD on FM is limited on the division of bandwidth between stations. By using RDS attached to a stream URL that would lock in and switch to a stream, stations could have better fidelity as well as a digital signal using the web to do the heavy lifting.

 

[davideduardo]

I have wondered if a system like RDS could be incorporated into car stereos/home units to switch between broadcast stations and internet streams. HD on AM doesn't have a good track record in terms of locking in a signal, and HD on FM is limited on the division of bandwidth between stations. By using RDS attached to a stream URL that would lock in and switch to a stream, stations could have better fidelity as well as a digital signal using the web to do the heavy lifting.

That is an interesting idea. RDS in Europe was initially developed with the purpose of automatically seeking the best signal for simulcast national services (which are prevalent in much of Europe where radio is very centralized). It might not take much of a change in the code to add this feature.

The only issue is that a high percentage of streams are not simulcasts... they are "similarcasts" with the stopsets being very different in content. If a signal falls back to a stream, the content may be interrupted.

 

[kfbkfb]

The key part of my proposal/idea is that currently unusable FM channels/slots
could be used for broadcasting by creating a special version of DRM (no new
broadcasting frequency range is needed).

As I mentioned, DRM+ (designed to be used in the FM band, among other frequency
ranges) already exists, IMHO, DRM+ could be adapted to work as I have proposed.

The beauty of a digital radio system is that a great deal of error correction can
be used to compensate for a low power signal, the low power signal would be
an easy way to keep possible interference (with existing FM signals) very low,
after all, certain FM channels/slots are only unusable for other FM signals, not all
other forms of modulation.

Also, being a digital system, various interactive/social media related functionality
could be included.

Kirk Bayne

 

[davideduardo]

The key part of my proposal/idea is that currently unusable FM channels/slots
could be used for broadcasting by creating a special version of DRM (no new
broadcasting frequency range is needed).

As I mentioned, DRM+ (designed to be used in the FM band, among other frequency
ranges) already exists, IMHO, DRM+ could be adapted to work as I have proposed.

The beauty of a digital radio system is that a great deal of error correction can
be used to compensate for a low power signal, the low power signal would be
an easy way to keep possible interference (with existing FM signals) very low,
after all, certain FM channels/slots are only unusable for other FM signals, not all
other forms of modulation.

Also, being a digital system, various interactive/social media related functionality
could be included.

Kirk Bayne

With the profusion of LPFM and translators, I don't think any significant population center has channels that are in any way usable for this.

And, like HD, it would take a decade or more just to get up to 50% penetration of the in-car market... and that is a light year away in today's radio environment.

 

[kevtronics]

When they were simulcasting on 107.1 and 99.7, NJ's "The Breeze" (WWZY/WBHX) used the RDS AF (Alternate Frequency) flag to automatically switch the listener's radio to whichever signal was stronger in their area. However, most U.S. market radios probably do not support this feature, even if they do display RDS text.

For example, the factory-equipped radio in my 2012 Subaru had an AF indicator in its display, as well as other RDS-specific indicators such as TA (Traffic Announcement), but the owner's manual made no mention of them, there was no option for them in the radio's settings menu, and I never saw any of them illuminate.

 

[davideduardo]

When they were simulcasting on 107.1 and 99.7, NJ's "The Breeze" (WWZY/WBHX) used the RDS AF (Alternate Frequency) flag to automatically switch the listener's radio to whichever signal was stronger in their area. However, most U.S. market radios probably do not support this feature, even if they do display RDS text.

For example, the factory-equipped radio in my 2012 Subaru had an AF indicator in its display, as well as other RDS-specific indicators such as TA (Traffic Announcement), but the owner's manual made no mention of them, there was no option for them in the radio's settings menu, and I never saw any of them illuminate.

The automatic transfer works on most European cars, because that is where multi-transmitter operations for one station are most common.

I note that even in many places in Latin America where there are many/most stations in such networks (Perú, Chile, Ecuador, etc.) RDS still only has this function in European cars.