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. There are very few (but not zero) rules around recieving radio signals.
Once you start transmitting though, things get way moire 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. Telco's pay millions for the licenses to those bands, and strongly protect their exclusive use of them.
If you "just use" your wifi/bluetooth radios as they were designed, you'll be complying with all the regulations (including things like ensuring you abide by geographically different available channels, 2.4GHz channel 14 and sometime 13 and 12 are not available depending on where in the world you are: https://en.wikipedia.org/wiki/List_of_WLAN_channels#2.4_GHz_... )
If you start screwing around at a low enough level to be controlling the radios without the higher level drivers - you become responsible for all the global regulatory shitstorms you might bump into. While that would be a fun thing to play with (and I say this as someone who's used a USB VGA dongle as an "SDR Transmitter" in ways that are _totally_ not legal where I live), it's not really a sensible path to go down if your goal is widely usable decentralised non-internet connected messaging.
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>)...
>"There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy."
Sorry, but a can’t help but think from your wordsalad here that you understand barely more about regulatory aspects of radio bandwidth use than Shakespeare did... I can’t even work out where to start to guide you down a path where your “Understanding of both Law and Radio” might start to intersect with reality in 2021 society. So I’m not even going to try.
One hint I will throw you about SDR - use the keyword “RTL SDR”, you’ll find many simple and amazing projects using USB tv tuner sticks available for ~$10 repurposed as Software Defined Radio receivers. These days they are used for everything from global flight tracking like Flightradar24 up to some amazing things like passive radar tracking planes via reflections from powerful radio station transmitters.
?
Two Questions:
1) What is the first principle of Law? Why does it exist?
2) What is the first principle of Radio? How does it exist?
?
Also, I might suggest that labeling others, while highly effective at shutting down debate (this technique is used by TV news anchors -- label opponents, then offer a quick quip as to what the majority in society would disagree with most with the label previously given, then feel good about having done so), is also equal-and-oppositely highly damaging to one's own continuing education, the education which, if it were continued with an open mind and without such actions -- would make a person highly (and I mean highly) effective over time, such that whatever they would seek in life, they would an uncannily high probability to attain...
That is the function of angles and possibilities, angles and possibilities not explored, angles and possibilities which are shut off if/when someone tries to shut down "opponents", by whatever methods (labeling, smears, painting them with a broad brush, etc., etc.)
But, for the sake of not provoking a debate, you want me to say that "I'm an idiot"?
Fine, "I'm an idiot."
You want me to say that I understand barely more about regulatory aspects of radio bandwidth use than Shakespeare did?
Fine, "I understand barely more about regulatory aspects of radio bandwidth use than Shakespeare did."
But here's the thing.
You see, I can say those things because I'm not afraid of the repercussions of saying those things (there are none for me. <g>)
I don't believe them for an instant, however.
Two Questions:
1) What is the first principle of Law? Why does it exist?
2) What is the first principle of Radio? How does it exist?
Everything that the FCC (and its counterparts in foreign countries) regulate -- are waves that are Hertzian in nature.
These types of waves follow the Inverse-square Law:(https://en.wikipedia.org/wiki/Inverse-square_law), that is, they drop off inversely proportional to the square of distance.
It's a good thing that they do, too, because otherwise everyone's radio transmitter of whatever type (cell phone, garage door opener, TV remote, Wi-Fi, etc.), would interfere with everyone else's -- and this doesn't happen.
Nature, via the Inverse-square Law -- prevents this for the most part...
But, while Hertzian waves are used by most of the devices we know and love, in Physics, there are also Non-Hertzian waves (scalar, transverse, longitudinal, etc.).
These require special equipment and engineering to both create and detect (compare to Gravitational Waves, LIGO, etc.), and they might be highly directional in nature (that is, if you're not in a very tight path, you cannot detect them, but that's a good thing, because it also means that they don't interfere with all of the radio devices that we know and love!)
You see, there is nothing in Physics that (with the right engineering) that prevents the transmission or reception of information on non-Hertzian waves, on any number of mediums.
Sunlight, the earth's magnetic field, radiation from space, and many other mediums -- could in theory be used to send and receive information... even Gravity itself could be, in theory, if it is a wave, and if it were properly understood...
Also, Quantum Communication -- the idea that you take a crystal (or some other medium), and split it in half, and (again, with the right engineering) now can communicate over large distances without an apparent medium between them -- this idea is Non-Hertzian in nature.
ESP, if it exists -- is Non-Hertzian in nature.
Non-Hertzian communications are the future (basically it's Star Trek technology).
Hertzian (which the FCC and its counterparts in foreign countries regulate and can regulate) is the present-day -- and the past.
In other words, a prediction: In the future -- there will be a disruption of Internet scale in Communications -- when Non-Hertzian communications technologies become dominant...
Also, with respect to Law -- the root of all Law (all human Law) is human agreement -- which is also the root of all man-made contracts.
Congress (or any other governing body) cannot change Natural Law -- that is, no act of human agreement will change the nature of Gravity, nor any of the Laws (pure laws, natural laws) that govern the physical universe...
Or perhaps as Star Trek's Scotty would so eloquently say:
"Ye cannot change the laws of physics!" <g>
The way you physically transport data can be safely decoupled from how you will encode and how you want your protocol to work. It makes thinking about the different layers easier and allow them to evolve independantly. Nothing prevents you from building an IP network using ham radio as a transport. The OSI model wasn't developed as a purely theorical concept. It does solve a practical problem.
Sometimes the most profound of truths, the most elegant of truths, are so simple, so as to be overlooked and/or written off by people.
In this case, you see, if "everything is turtles" all the way up, then at the base layer, the turtle all the way at the bottom, the turtle who rests on no other turtle, well that turtle is "radio".
Let's change the topic and talk about cars for a second.
You have drivers, people who can drive a car, that is, people like you and me.
But then you have a subsection of these people, who are mechanics, who can fix most typical problems that a car might have, but there are limits to their capabilities; they couldn't make a car more aerodynamic, or reengineer a gas car to be an electric one, etc.
Then you have, as a subsection of Mechanics, Car Design Engineers (all Car Designers are in effect Mechanics also, because their knowledge is a superset of the mechanic's knowledge).
The Car Design Engineer can do "miraculous" things that an ordinary Mechanic cannot -- he or she could make a gas car electric, an electric one gas, could design for higher MPG, could swap out systems, etc., etc.
The Mechanic works at a lower level of abstraction than the car driver does, and so, can do many things that an ordinary car driver cannot, but the Car Design Engineer works at a still lower level of abstraction than the Mechanic -- and thus he or she can do "miraculous" things that the Mechanic cannot...
"It's all raw radio" -- is the simple, elegant, most profound truth at the bottom of the stack of turtles (compare to the concept of common denominators in Mathematics), it's the lowest-level abstraction, it's the abstraction level that, should we work from it upwards (rather than pre-built protocols, drivers and stacks) downwards, we'd find that we can do things that we otherwise couldn't, if we were forced to work within the constraints of all of those pre-determined systems.
Finally, the Internet itself -- the Internet itself -- IS A SERIES OF ABSTRACTIONS -- a series of "Turtles on top of other turtles".
The Internet itself...
Meditate on that one for a second... I did, and the implications of that meditation were profound!
Why shouldn't someone commit to learning about all of those levels of abstraction, and gaining the corresponding power of amazing engineering (aka, "abstraction working") abilities -- should that knowledge be gained?
Let me know if you're interested in brining to life your suggestion :)
I greatly appreciate your kind and uplifting comment!
(Although, and I'd say this to everyone else, I also appreciate highly critical comments -- because they challege me to think, to really think, to refine exactly where I stand on a position in words, and to fix that position if it contains any inconsistencies... On a side note, I should write that down in my philosophies in the future -- good comments (like yours!) are good, because they're positive and uplifting, but "bad comments are also good" (paradoxically!), because they force you, they challenge you to really think...)
>"Let me know if you're interested in brining to life your suggestion :)"
Well, I greatly appreciate it, but I don't have the time for it... I'm merely adding some ideas to the discussion.
You know, add some "lively" ideas -- to an already "lively" discussion! <g>
Anyway, thanks again for the kind words!
Two ones I've been paying close attention to are; https://www.meshtastic.org/ http://disaster.radio/
Legality-wise can get complicated, there's only certain frequencies you're legally allowed to run encryption on, and then there's wrinkles around hardware and transmission power.
The thing that makes the cellphone mesh network work is that they spend lots of money getting their antennas up high above the terrain and getting power to them.
[1] Yes, there's sporadic e tranmission but it's just that, sporadic. And yes, there's troposcatter but that literally requires kilowatts and highly directional large antennas.
https://changelog.complete.org/archives/10205-roundup-of-sec...
First ht on Google seems to agree: https://www.meshtastic.org/software/crypto.html
Cell phone OSes automatically disconnect from these of course, there's no way to connect to the ad/telemetry services so what good would it be anyway?
Not all phone OSes. None of my iOS devices disconnect from local WiFi because they don't have Internet connectivity. I do this this all the time with several devices I have that broadcast their own WiFi for remote control connectivity.
Not to mention that there is huge mesh networks around the world deployed by private persons, all using WiFi over KMs of distance.
- Freifunk - Germany - https://freifunk.net/
- Guifi - Spain - https://guifi.net/en
Guifi is probably the largest of those, with 36.924 online nodes, most in Spain but some in other parts of the world. If my memory serves me correctly, there is peering working/in progress between Freifunk and Guifi as well.
There is also this: https://news.ycombinator.com/item?id=25412367 which was recently discussed on HN.
I dont think you said what you think you said.
If I were going to go this route, that is, to engineer a network not dependent on the Internet -- I'd first go down to the most fundamental principle of WiFi, Bluetooth, ZigBee, EDGE, EVDO, LTE, etc. -- and that most fundamental principal is RADIO.
From there, I'd ask the question -- how can any device which implements one or more of the wireless protocols that we all know and love: (https://en.wikipedia.org/wiki/Comparison_of_wireless_data_st...) be converted back to raw radio?
If it can be done, use that and design upwards.
If it can't be done, then use the lowest abstraction level (above raw radio) possible that can be used for the device in question...
That's the comm side of things.
The "next job up" is to figure out the logistics of user adoption, getting these radio devices to communicate, what bitrates to use, what access patterns to use, how do you get data over longer stretches (if there's no user/node to hop off), etc., etc.
But, quite the technical challenge!
Of course, you can "cheat" -- and use pre-made protocols/software/drivers -- which gets you the highest amount of abstraction (but the least amount of control).
SDR -- Software Defined Radio -- would seem to be a good middle ground between these two areas of abstraction...
I'd almost argue that if someone were to make the simplest of all SDR's that could turn ordinary WiFi cards and devices into SDR, and couple that with a store-and-forward network like FidoNet or Bitnet (if anyone remembers those!), then they'd be in business!
Anyway, it's a very interesting and challenging project!
I wish you the best of luck in this endeavor!