What I don't get it is, why make the software enforce certain frequencies? If the hardware should never be able to broadcast on a certain frequency, why not build the hardware with that limitation?
So the FCC's response in the past was to make it illegal to produce anything that could go from [unlicensed power level] up to [licensed power level] on demand. If you wanted to make a 10M amp that could hit say 150W, you had to require at least 75W drive power because that was beyond what a legal CB radio could deliver. Kinda sucked for anyone who couldn't afford a radio with 100W of drive, and I think they eventually let off a bit because they were losing the battle to cheap Chinese junk sold over the internet. They're very proactive about enforcement, they'll get you sooner or later, but until then it's better for everyone if you're not spewing harmonics everywhere.
There are radios and amps that use a frequency analyzer to automatically cut out when operated out of their intended bands, they're just very expensive compared to most of the gear that's out there. And a lot of the Software Defined Radios and so on are actually wideband radios that are physically capable of operating across a bunch of bands. These are very concerning for the FCC, and you pretty much cannot limit these physically, it has to be built into the firmware or the controlling software. Hence the article.
There's also just different rules for different license classes. As a radio amateur, I can also use 2.4 GHz (13cm band) under my license, and I am allowed to operate with up to 1500 to 2500 watts EIRP depending on mode. That is of course subject to lots of limitations including "minimum necessary power", but there's nothing physically stopping you from taking a 13cm amp sold for radio amateurs and running wifi over it. Same frequency, how does the radio know?
Why is that expensive? It obviously can't require fancy hardware if it can also be done in software.
Imagine trying to design a calculator that isn't allowed to display the digit '8' on its LCD display.
In software, the implementation sees if the LCD is being set to a value that contains '8' in binary and if so, ignores the input.
In hardware, you have to have a camera that is pointed at the LCD, and a hardware OCR implementation that looks for the 8, and then a circuit that when the OCR implementation sees an 8, turns off the display.
1. If you have a single radio unit, you can easily do the "software" implementation where you look at what you're going to be broadcasting and cut it off if it's not legal. The problem comes when you have separate radio and amplifiers - the amplifier has no idea what whether you're feeding it 10M or CB frequncies. It will amplify either just fine, so the FCC really prefers you to build in a "hardware" type implementation there (a frequency analyzer that figures out what's going into it). It's just expensive to do so - like if you didn't already have a digital amp, you might easily add 1/4 or 1/2 to the cost just to get some dumb logic built in. And you can still probably get around it if you really try.
2. There is a disproportionate amount of cheap gear and old gear in circulation. We didn't get "smart" rigs until the late 90s at a minimum, and even so they are vastly outnumbered by stuff from the glory days of the 50s, 60s, and 70s. There has always been a relatively small amount of high-power stuff in circulation, and there's even less smart high-power stuff. A lot of the modern kit-built stuff like the Elecraft K2 focuses on QRP (effective operation on low power) instead of crazy high output.
3. This manifests as a CRAZY price curve. It's relatively easy to get an old radio from the 70s that'll do 50 or 100W (especially after factoring in weak, aging tubes, etc). A modern mini-rig that will do 25W or something is also relatively affordable. But if you want something new, powerful, or new AND powerful you can easily jump into the thousands of dollars. For the cost of a modern rig that'll do any given power level, you can afford an older rig and an amp that will put out an equally good signal with substantially more power. Or with a better antenna. And so on.
4. There's nothing wrong with the old gear and things like tubes can be fixed. If you trash your new wünder-rig it's garbage. So given that amateurs are crafty people (the proto-hacker, really) there's a strong incentive to make the old or lower-power stuff work, because it's repairable when it breaks.
Why is there significant expense in putting a ROM chip between the radio and the amplifier that cuts out certain frequencies? I can see where that's not as simple as mandating software that is simply incapable of generating bad frequencies in the first place, but it intuitively strikes me as the same sort of embedded programming that goes into, say, a microwave oven--I can see it adding some cost, but not so much that it would be unfeasible in e.g. an home wifi router. What am I not understanding?
Adding a protection device merely shifts the problem (being discussed) from the radio to the protection device.
It achieves exactly nothing.
An example of the former is "homemade AM radio", where you wrap a lot of wire in a coil, and changing where you complete the the circuit along the coil allows you to "tune into" different frequencies.
An example of the latter is the cantenna, a directional antenna that can be made from a Pringles can.
The list of blocked frequencies changes occasionally (like time zone definitions); if you can't update the "illegal frequency blocking" chip then it becomes illegal to use your otherwise-perfectly-good product once the rules change. Plus, it depends on what country you're in, so ideally if you move (or just go on a vacation) to another countries you don't want to have to throw away your old router/smartphone/smartwatch and buy new ones in the other country.
With the help of an auto-tuner to match the SWRs there's no physical reason I can't transmit/receive bands I'm not supposed to. It's not like tweaking a VFO is really a technical challenge, they're well-understood technologies. And the frequency display on my radio is literally just a frequency counter for my own edification, the base TS-820 non-S model doesn't even have one. To find your frequency you look at the dial, there's a printed scale for your band. You know what happens if you are pushing the limit too far? The FCC tracks you down and you get a pink slip telling you that they know what you're up to.
You both underestimate what older radios can do, and overstate what newer radios can do relative to them. The reasons that you didn't see people transmitting off-band before was primarily social, not technological. As for receive, the FCC was flipping out about people intercepting cellphone calls on omniband radios - 15 years ago. Omni SDR was around 10 years ago too, with the same capabilities (see: GNU Radio), it just cost more than $10 for a rig.
>Wideband radios are not all that new.
No, but super cheap ones are.
>It's not like tweaking a VFO is really a technical challenge
Well, it's a little bit of a challenge for most (especially non-hams), but sure, there's no magic involved.
>The FCC tracks you down and you get a pink slip telling you that they know what you're up to.
I've heard so many scary stories about the FCC, and yet their enforcement actions page is relatively empty; and hams are always heard complaining about both persistent abusive behavior that the FCC either does little, or is powerless to stop. My impression is that violators, both abusers and unintentional get a lot of chances to correct their behavior; and that FCC enforcement is mostly a paper tiger that can do a bit of damage to someone who wants to comply (for the most part), and can do very little or nothing to stop the worst abusers.
Enforcement actions: https://transition.fcc.gov/eb/AmateurActions/Welcome.html
Warning Letters: http://transition.fcc.gov/eb/AmateurActions/Legacy.html
>You both underestimate what older radios can do, and overstate what newer radios can do relative to them.
I don't think so. I know that these features, or reasonable substitutes for them exist/have existed for some time, but I also know that their widespread use was limited, primarily due to cost. Economies of scale in manufacturing mean that since a TV tuner chip which produced in the billions can be used as an SDR, now there are lots of very inexpensive SDR units available for purchase. For higher end equipment, there is also the fact that DSP tech has advanced at a pretty incredible pace enabling things like the ~$300 dollar 100MHz oscilloscopes in my lab and also the 500MHz scopes in my lab that didn't cost more than our minivan. Sure, many (maybe even most) of the things that can be done with an SDR can also be done with solder and wires, but an SDR can do any/all of them. A super cheap (as in < $10) SDR can act as a frequency analyzer (to use GP's term) can compliment a high quality analog radio design. I suspect that one could add that kind of feature to an analog radio and keep the total additional cost under $10.
>The reasons that you didn't see people transmitting off-band before was primarily social, not technological.
I think you've hit the nail on the head here. There simply isn't any/much of a problem, and where the problems do exist the FCC is largely toothless anyway (and that's arguably a good thing). The FCC sees the potential for cheap consumer equipment that can easily be made non-compliant; they know that they haven't the resources to enforce the rules against millions of people and want to simply prevent it from happening. There is a reason that the FCC has so little enforcement is because nobody who knows them, likes them.
>FCC was flipping out about people intercepting cellphone calls on omniband radios - 15 years ago.
Another reason to dislike the FCC, they made a rule which was almost totally ineffective, and today is completely moot; because the technology prevents the problem that the rule was supposed to prevent. The cost of scanners/radios went up, and some good products were taken off the market and replaced with junk, or simply not replaced. Yay FCC.
> Omni SDR was around 10 years ago too, with the same capabilities (see: GNU Radio), it just cost more than $10 for a rig.
A lot more than $10, and you had less "SD" for your SDR because your PC and the software was simply less capable. Now, a relative noob can start from practically nothing and point and click his/her way to receiving any number of things in an afternoon.
That said - I am not condoning the FCC policy at all - I'm actually against it - I just don't really care that much because it impacts nothing I do and so few use cases I care about.
You sure have spent a lot of time ITT explaining to everyone, advocating, practically that the FCC ruling is unimportant because you think that your own interests will be unaffected. Well, congratulations, but if we were all so short-sighted we'd eventually be reduced to only the hobbies and activities that a majority of us approve. We get it. You don't care, because you don't think it affects you.
In this thread my only point is the FCC hardware restricting instead of requiring software restriction neuters SDR to begin with so is a dead end. It's all or nothing insofar as "protections" go. My view is still it should be nothing, but I don't think it is as big a deal as its being made out to be.
Um, what? Pretty much every device that does wifi has a SDR in it.
The new regs themselves do not state this requirement. It lists several possibilities for manufacturers to guarantee conformant emissions from their device, several which will continue to allow 3rd-party OS firmware.
Admittedly, the brave new world looks like region-locked devices and cheaper routers that truly are locked down in the exact ways we don't want, but that is not a hard FCC requirement, just a side-effect of the new regs on APs that have poor separation between OS and radio module.
There are plenty of uses for radio software that don't involve going outside approved frequencies.
Unlike 2.4GHz ISM, nothing gives you the right to transmit on 5GHz U-NII bands (well, there's a bit that overlaps with secondary amateur spectrum) than otherwise permitted through the same FCC approvals process every device manufacturer must undergo.
That was the case before the new rules. Now the new rules are imposing sucky requirements for U-NII device software security.
However, that's been largely misinterpreted in every discussion I've seen recently.
For some context, check out https://wirednot.wordpress.com/2014/01/07/what-else-is-in-th...
You really don't want U-NII devices configured for Japan to be stomping on licensed spectrum in the US; you also need all that power negotiation, radar/interference avoidance algorithms in your radio so we don't get the same 2.4GHz mess happening in 5GHz.
That being said though - this is meant to apply to software defined/modular radios - that is systems wherein the entire point is that it does what the software tells it instead of having hardwired components meant only to receive certain frequencies.