First of all, a lot of good info, so I appreciate that!

I'm not going down this route right now (too many other priorities), but I like to think strategically about this subject, as I do about many others.

>"SDR became wildly popular (well, relatively, amongst geeks) when someone worked out a ~$10 usb dtv tuner could be used easily as an SDR receiver."

Strangely, I never heard about this, but I'd be interested to learn more; links/references?

>"Once you start transmitting though, things get way more complicated very quickly. Some of those radio protocols you listed (Bluetooth/WiFi/ZigBee) typically use "ISM" radio bands, where the rules are less stringent (but there are still rules), some of the protocols you mention (EDGE/EVDO/LTE) will very quickly get you found/shutdown/fined if you start transmitting on them."

I don't question that certain types of radio transmissions may offend one or more people; and/or one or more "powers-that-be"...

But, let's clearly, and I mean super-clearly understand the exact specifics of what those are, because you see, there is room, there is a lot of room for experimentation -- outside of those parameters.

You see, what someone can or can't do, radiowise, is largely determined by a matrix of different factors -- think of this as a giant Excel spreadsheet -- but with multiple factors determining whether something in radio can be done or can't.

So let's talk about some of those factors.

One of them is the distance to other people. If I live in a cornfield in Nebraska, and my next door neighbor is 35 miles away, unless my radio transmission goes for more than 35 miles, it probably isn't going to piss off anyone.

Conversely, if I live in a tightly packed city, like New York where my next door neighboor lives in an apartment 20 feet away -- then 20 feet might be the largest practical distance that my radio transmission might be able to go before it pisses someone off.

So that's one aspect of this 'matrix'.

Another aspect is, what country do I live in?

Because different countries have different rules.

On the ocean, at 200+ nautical miles from the coast of the nearest country, or on the North Pole, or South Pole, or in Outer Space (if I can get there) -- I can probably get away with a longer broadcast -- without pissing anyone off.

But those are only some of the parameters of this matrix.

Another parameter is frequency, another parameter is power relative to that frequency, another parameter is the directionality of the transmission (for example, am I using a directional radio beam formed by a cone-shaped transmitter, and how does that beam spread out, and how far does it go, and who is in its path?).

Then, there are what are called "Caduceus Coils" -- they're a special coil/broadcast antenna -- which if it designed correctly, acts like the "laser beam" equivalent, except for rf; the radio transmission.

If that tightly focused radio beam is about the size of a dime, and travels directly, over air, to its target location (which is some other guy agreeing beforehand to receive that transmission, to become a "node" on the network"), then that radio transmission will not interfere wtih any other radios (receiving or transmitting) outside of that laser-thin line; in other words, it should interfere with no-one, it should not piss any person or power-that-be, off...

You see, to quote William Shakespeare's "Hamlet":

"There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy."

I don't mean to offend you by saying that; but you see, there's always another angle; another possibility that may have gone unthought-of (until someone points it out).

In other words, "Don't assume", or phrased another way "Assume Nothing" (Mike Abrash).

Yes, people would probably get offended if you connected with a cell phone tower on one of their frequencies using one of their protocols without their permission -- but I am not proposing that that be done!

Instead, I'm saying -- look at the possibilities.

The multi-page spreadsheet/matrix of factors must be created and then consulted to see where the empty spaces are (empty space = opportunity for experimentation!).

Anything that is not prohibited -- is, and must be by default, permitted! (You know, that old Grace Hopper "permission vs. forgiveness" debate!).

>"you'll be complying with all the regulations"

My question is this: Do the regulators even understand what they are regulating?

I understand both Law and Radio technology.

I could do their job; they probably couldn't do mine...

>"it's not really a sensible path to go down if your goal is widely usable decentralised non-internet connected messaging."

Yes, but my goal isn't to go down this path -- it's to think about what to do about greater shitstorms (greater amounts of shit hitting the fan than it does already) if and when they happen!

I hate to dumb it down to this level, but proverbially speaking, in this matter "I'm the good guys" (er, guy, singular, as the case may be... <g>)...