Sunday, December 7, 2014
Digital Broadcast Radio Sample
Here's the sample page, from Digital Radio Mondiale (DRM). Most of the stations on the displayed map have two buttons, one for ordinary AM and one for DRM. Of particular interest is the pair in the lower right hand corner, showing what is possible at a very low bit rate over a very noisy propagation path. Go over there and click around for a few minutes.
(1) When are we in the U.S. going to push this non-functional withering-on-the-vine IBOC hybrid standard overboard and get serious about digital signals on the current AM broadcast band?
(2) We're so far off the back on in this field that even Pakistan is years ahead of us.
(3) Back to the DRM demo page, in particular that lower-right sample, it's pretty remarkable what can be done with such a low data rate. That sample was transmitted at 16 kbits/s, and punched through a noisy path that would make ordinary AM nearly unlistenable for spoken voice, let alone enjoyable for music. (More details about the relationship between bit rate and noise can be found at the article on the Shannon-Hartley theorem at Wikipedia.)
(4) Digital Radio Mondiale ≠ Digital Rights Management. Calling this open digital radio standard "DRM" in the U.S. is a sure kiss of death with anybody under 35, or for that matter anybody else who's been paying attention. Say "DRM" in front of most tech-savvy folks and the next thing you'll hear is "Oh great. How much will we have to pay Microsoft this time?" When in fact, Digital Radio Mondial is an open standard that has nothing to do with fees and software lock-in. But remember: If you have to explain don't bother. Call it "DRW" or something else in the U.S., or it's DOA.
OK, thus ends the rant, now begins the wait. Waiting for what, you ask? Waiting for the AM broadcast band to completely crash in this country, clearing the business space for a full-on digital rebirth. Waiting to pick up spectrum allocation and possibly hardware at fire sale prices. Waiting for this investment opportunity. I predict five to ten years.
ps: One more item for the list:
(5) Content, Content, Content. If there's nothing worth listening to, it doesn't matter how clear the signal comes in.