Will analog radio go dark in 2015?

[TheBigA]

I can imagine a future for the current FM band wherein groups of co-owned transmitters throughout a particular market would be joined together into a single digital radio data network that was distributed across multiple frequencies.

Would that not require FCC approval?  And why would the government approve such a plan?

[RadeoEngineer]

I can imagine a future for the current FM band wherein groups of co-owned transmitters throughout a particular market would be joined together into a single digital radio data network that was distributed across multiple frequencies.

Each transmitter would broadcast a portion of a composite data stream. The aggregated digital bandwidth could be combined by a very broad-band receiver into a single high-capacity data stream. Error-correction data could be distributed throughout the composite signal so that the temporary loss of reception of one or more of the individual carriers could be accommodated.

This could be done as a single-frequency system too, but only if we completely abandoned the long established analog-based frequency allocations.

Either way, the result might be a localized, terrestrial version of the Sirus/XM broadcast model. Video or data services could also be incorporated.

Needless to say, our dear old analog broadcast system would have to be deliberately run down, dismantled or destroyed for this kind of technology to be realized. The VHF real-estate would certainly be a lot more valuable if it were 'shovel-ready' and didn't have all those old-fashioned 'radio stations' cluttering the landscape.

Perhaps that process of creative destruction is already well underway. If so, is it inadvertent or deliberate?



Isn't this alreay called "Eureka?"

[Lee Rust]

Such a networked broadcast system idea is indeed similar to Eureka, and might well end up being just as unsuccessful.

I'm not necessarily advocating such a plan, which could not happen under current FCC policy anyway.  It's just one possible extreme extension of the 'digital-no-matter-what' corporate and cultural mindset that seems so prevalent these days, in every technology.

Certainly, HD Radio is a product of this particular mindset.

[TheBigA]

I'm not necessarily advocating such a plan, which could not happen under current FCC policy anyway. 

Exactly...my point is that the FCC has every intention of keeping terrestrial radio analog, regardless of the consequences.  While at the same time doing everything it can to encourage the expansion of the digital highway, even to the point of providing universal high speed internet access.  They may not be able to guarantee universal health care, but if you're sick, you'll be able to surf the net for free.

[K6JHU]

We have a set of existing distributed repeaters, all synchronized with the same programming, available in almost all metropolitan areas. It is called Sirius/XM.

[Lee Rust]

Just how extensive is that Sirius/XM terrestrial system? Could the service have full coverage of the big markets even without the satellites?

[BRNout]

Just how extensive is that Sirius/XM terrestrial system? Could the service have full coverage of the big markets even without the satellites?

From my experience: no.  Not even close.  The terrestrial transmitters are placed in busy locations where buildings block the view to the southern sky.  However, if you drive slowly (so that you lose the buffering) under trees or bridges in the suburbs and outer parts of cities, you'll find that the XM/Sirius signal disappears.  Their system of terrestrial transmitters is far from comprehensive.  It's merely there to fill in glaring coverage gaps in densely populated areas. 

Solid digital radio distribution requires the frequent placement of transmitter multiplexes, as they've done in the UK.  And, even there, it's not good for long-distance travel.  However, as they use a different part of the spectrum than MW or FM, at least there's no interference with terrestrial radio.  The 2015 all-digital switchover is a stated goal over there, but there's also a lot of skepticism that it will take place at that date (if ever). 

Lastly, I totally agree with most of the posters here with respect to this headlong rush to all things digital.  Mr. Savage stated it better than most, basically it's a less robust way of communicating the same information.  To me, it's a bad idea to depend on digital for anything important.  It's fun and offers a lot of entertainment options for the consumer - but it's not 'better' than analog for basic things.  The LP to CD discussion is a perfect analogy.  Yes, the CD sounds cleaner (almost too clean) and the LP is subject to scratches, pops and static from dust.  But, the LP will exist for hundreds of years - albeit with less than perfect fidelity.  As for the CD or MP3 file, they're gone as soon as one piece of data is corrupted. 

Reminds me of that show "Life Without People."  Caveman wall paintings last thousands of years; painted portraits last hundreds of years, film photographs last for decades, digital photos will be gone as soon as heat or cold corrupts the files.    It's not better; it just offers different options. 

[Darth_vader]

"As for the CD or MP3 file, they're gone as soon as one piece of data is corrupted."

Not necessarily. An MPx file (there are three different audio layers of the MPEG-1 standard that are commonly in use, 2 and 3 being the most prevalent) is really nothing more than a series of "frames" in which audio data are stored in.  Think of it in terms of movie film: if a single frame is cut out of a movie and the two ends of the filmstrip are spliced together, the single frame will be gone but, barring mechanical issues with the projector (and the abilities of the dude doing the splicing) you will still see the rest of the movie. So if part of an MPx audio file is missing or corrupted, in most cases, the file still continues playing. You might either hear a "chirp" or a "pop" or whatever wherein the missing data were.

In fact, this is how (why) DVB audio (usually MPEG1 layer 2 based, if it isn't using AC3 which I don't know much about) and MP3 streaming works and why you can generally begin listening at any point in the broadcast. Also why if you stop coding an M3 file about halfway through, you can still (in many cases) play back what you have, but it stops where you stopped coding it.

As for CDs: by my experience it depends on the quality of the drive and software/firmware etc. you are using to play back on. I have noticed some drives and programmes handle disc errors like scratches better than others.

(And here is another thing to remember: contrary to popular belief, if you store CDs loose, it is actually safer to set them down with the playing surface facing down, like you'd insert it into the drive. The data layer on a CD is just a few microns underneath the top of the labelled surface. So if there's something abarasive on the surface you set the disc on and silvering gets beaten up or scratched, the disc can get ruined. You can often buff out scratches in the bottom surface and have the disc still be playable--not so in the top surface!)

[StephanieNYC]

I'll again challenge anyone to cite an example of any system developed by evolution or "God" that uses a a digital mode.

Well, I'm looking at the light switch screwed onto my bedroom wall here. That's digital!

You flick the little lever up and the lightbulb goes on.  You flick it down and  the bulb goes out.  Can't hold it in the middle and have the bulb be "half-on".

Yah, that's digital, alright.   

Ok.  I'll go stand in the corner now....

[SUPERCASTER]

"As for the CD or MP3 file, they're gone as soon as one piece of data is corrupted."

Not necessarily. An MPx file (there are three different audio layers of the MPEG-1 standard that are commonly in use, 2 and 3 being the most prevalent) is really nothing more than a series of "frames" in which audio data are stored in.  Think of it in terms of movie film: if a single frame is cut out of a movie and the two ends of the filmstrip are spliced together, the single frame will be gone but, barring mechanical issues with the projector (and the abilities of the dude doing the splicing) you will still see the rest of the movie. So if part of an MPx audio file is missing or corrupted, in most cases, the file still continues playing. You might either hear a "chirp" or a "pop" or whatever wherein the missing data were.

In fact, this is how (why) DVB audio (usually MPEG1 layer 2 based, if it isn't using AC3 which I don't know much about) and MP3 streaming works and why you can generally begin listening at any point in the broadcast. Also why if you stop coding an M3 file about halfway through, you can still (in many cases) play back what you have, but it stops where you stopped coding it.

As for CDs: by my experience it depends on the quality of the drive and software/firmware etc. you are using to play back on. I have noticed some drives and programmes handle disc errors like scratches better than others.

(And here is another thing to remember: contrary to popular belief, if you store CDs loose, it is actually safer to set them down with the playing surface facing down, like you'd insert it into the drive. The data layer on a CD is just a few microns underneath the top of the labelled surface. So if there's something abarasive on the surface you set the disc on and silvering gets beaten up or scratched, the disc can get ruined. You can often buff out scratches in the bottom surface and have the disc still be playable--not so in the top surface!)

Since an internet connection such as dial-up, DSL, cable, FiOs, WiFi, or WiMax streaming is bi-directional, missing or corrupt data  packets can and often are resent in the buffer interval. The recipient computer detects the error, signals the sender and the missing data can be resent and replaced. This is one method of error correction. There are others.