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Sharing the Airwaves: Spread-Spectrum Broadcasting
NaDrew writes "From the SFGate: Hal Plotkin writes about how Spread-Spectrum broadcasting technology could revolutionize the way we listen to the radio, and make it incredibly easy for neo-broadcasters to start their own services. Sadly, he writes, the "often technically inept U.S. Congress has complicated the situation in recent years by shortsightedly instructing the FCC to sell or lease additional bands of spectrum that had been reserved for other uses." Not to mention "the media conglomerates that own most of the nation's TV and radio stations have a vested interest in the status quo and won't easily give up their hammerlock on what, in the end, are public airwaves." A fascinating article that also includes some history of Spread-Spectrum technology (did you know it was patented by Hedy Lamarr?)." A good primer to spread spectrum if you're new to the issue.
(did you know it was patented by Hedy Lamarr?)
That's Hedly!
*** Where are we going? And what's with this handbasket?
Sure if you are not tuned in, it looks just like noise.
But if people are not careful what will happen is the noise floor is raised higher and higher till it drowns out signals.
Yah that isn't close to happening yet, but the way it's being hyped as if everyone and anyone can broadcast at the same time, it might happen sooner than expected.
Using spread spectrum technology greatly increases bandwidth available. We are figuring this out 75 years after the invention of radio, so wouldn't any one else out there be doing the same thing? Are we wasting time looking for a strong signal from space when a spread spectrum signal would look just like increased static coming from a planet.
Free cell phone tracking
Therin lies the real problem with spread spectrum vs. conventional broadcasting channels. The limitations of conventional communications techniques is part of what stimulated the development of these more efficient algorithms. And since different groups are confined to their own frequencies, there was little stepping on toes.
But with spread spectrum, there is no pressure to be efficient, because there are no direct limitations on how much you can broadcast. The only problem is background "noise" from other broadcasters, and the easiest way to overcome that is with a more powerful broadcast. The obvious result is an escalation of more people talking louder.
It's like being in a nightclub, where everybody has to scream and repeat themselves to make themselves heard, but communication is near impossible anyway. The only one that can really be heard are the super-amplified guys on stage.
What we need is a more efficient and publicly-accessible use of the airwaves. Deregulating them will give the folks with the big antennas more control, not less.
---If you can't trust a nerd, who can you trust?
Using spread spectrum technology greatly increases bandwidth available
This just isn't true, any more than weaving around increases the width of a roadway. Sure, it might let you dodge some obstructions, but in the process you become an obstruction to other trafic. The total amount of information that can be carried doesn't increase. Just like in the weaving-around-on-the-road analogy, you have to ask, what would happen if everyone did this? The answer, of course, is that to a good first aproximation all those other SS broadcasters would look like noise to you; so the ambient noise level goes up and the S/N ratio falls, meaning less information gets through.
How much less? well, in an ideal world, if you do everything right you only lose exactly as much as you thought you'd gained. TNSTAAFL.
Each photon you reveive can only tell you so much. You can't beat the uncertanty principle with hand waving.
-- MarkusQ