9 ms·

The United States Frequency Allocation Chart

jonathanmkeegan 4y ago
This crazy, beautiful chart illustrates the incredible complexity of managing one of our nation’s most crucial – and invisible – national assets: the radio spectrum.
user3939382 4y ago
The amount afforded to corporations vs unlicensed or amateur use gives you a good picture of how the power dynamics work in our “democracy” https://scholar.princeton.edu/sites/default/files/mgilens/files/gilens_and_page_2014_-testing_theories_of_american_politics.doc.pdf https://scholar.princeton.edu/sites/default/files/mgilens/fi...
- dan-robertson 4y ago
  Most of the allocations seem quite reasonable, eg lots of navigation, radio astronomy, etc, which don’t seem particularly corporate to me. I guess TV is corporate but there are a lot more people who watch rev than listen to amateur radio. Similarly people get pressure good use out of mobile phones. Plausibly it would be good if more of the spectrum was available for Wi-Fi. I guess one question is: are there amateur/unlicensed uses that are starved of bandwidth (Wi-Fi does strike me as something that fits but is there anything else)?
  - Reason077 4y ago
    > "are the amateur/unlicensed uses that are starved of bandwidth (Wi-Fi does strike me as something that fits but is there anything else)?" WiFi 6e / WiFi 7 are getting a huge swath of bandwidth between 5.9 and 7.1Ghz in the US and Canada (but somewhat less in Europe/Japan/Australia/etc) Even with current 5 Ghz WiFi, a lot of routers seem to not let you select the DFS/TPC channels above 48 even though they're perfectly legal to use in most places. As a result, those channels are far less congested.
    - dan-robertson 4y ago
      I thought there was some tricky channel switching logic because of some other non-Wi-Fi uses of part of the 5GHz band, so maybe service degradation when switching away or just disabling the channels for a long time when the conflict-detection fires causes those channels to not be used much?
      - Reason077 4y ago
        I've certainly never noticed it switch channels on me in all the years I've been using it in the UK.
    - varenc 4y ago
      The DFS channels have big downsides though. I don’t know much about TPC but for DFS, if your access point is on a DFS channel and it detects weather radar usage there it has to immediately get off it. It also has a slow start up period where it must first listen for radar traffic before transmitting. Though if you’re in an area without any radar on those bands it could be well worth it.
      - Reason077 4y ago
        Yeah, it does increase boot time a bit while the initial scan happens. But hopefully you aren't rebooting your router too often anyway. Small price to pay for avoiding WiFi congestion if you're in a busy building/area. It's a huge performance penalty if some other nearby network is sharing your channel, so DFS is one small downside for a very big upside, IMO!
      - wtallis 4y ago
        In the US, it's only one specific type of weather radar (TDWR), which is only used at 45 major airports. If you don't live near one of those, you only have to worry about a false positive in the radar detection feature accidentally knocking you off a DFS channel. And I know from experience that local topography sometimes means you can be operating an AP on a DFS channel only a few miles from one of those airports without ever having a problem.
- tptacek 4y ago
  https://www.chapman.edu/esi/wp/porter-smith-hazlett-radiospectrum.pdf https://www.chapman.edu/esi/wp/porter-smith-hazlett-radiospe...
  - user3939382 4y ago
    It's well-written but I totally disagree. Coase's prescription of auctions is precisely the means by which the People have had huge portions of the spectrum hijacked by megacorporations that they, in turn, use to extract rents from the public, while we get some overcrowded crumbs for our own use. This market-based analysis, which is typical, omits the factor of nearly complete regulatory capture, i.e. our reality. > Coase anticipated that full, fair, well-informed evaluations would find that decentralized resource owners generally outperformed state diktat. That omission is pervasive, as if "state diktat" is some force independent of these same resource owners.
    - kortilla 4y ago
      Is it regulatory capture or an auction? Those things aren’t related and they are kinda opposing. Regulatory capture would prevent entrants from even having the option to bid for spectrum.
      - user3939382 4y ago
        The auctions pit average citizens individually against the resources of megacorporations. Obviously it’s no match, the outcome of that contest will inevitably be what we have now. The point I’m making is pretty simple which is merely that the public deserves way more unlicensed and amateur spectrum. The government serves the types of corporations participating in these auctions, to the exclusion of the People, so that’s probably not ever changing.
        MichaelZuo 4y ago
        The point of any auction is to determine who 'deserves' what. Your reversing cause and effect. And it's not like every auction winner is guaranteed to make money, there are cases where they overbid and ended up losing money, to the benefit of the regulator, which is indirectly benefiting the taxpayer.
- pphysch 4y ago
  See also IP address allocation and DNS (TLD) allocation. Hierarchy is something like: 1. US military/intelligence 2. Transnational corporations 3. Other large orgs/governments (distant) 4. People
- Panzer04 4y ago
  In practice do we need more reserved/unallocated bands? The problem with unlicensed bands is interference and the like - they can't be used together without stomping eachother (eg. in FPV RC, analog and digital transmitters have difficulties because digital stomps the analog signals). Arguably given the above it would be useful to have a larger range of frequencies available to amateur/unregulated users, but it's also probably true that the general public gets more utility from more 4G LTE spectrum, if we're honest.
- mensetmanusman 4y ago
  You can operate in any frequency so long as you are in a faraday cage :)
  - user3939382 4y ago
    True. They have RF blocking paint and window films. I’ve always been curious to see how far I could get creating one in a normal looking room. I was thinking of combining this with a 4G repeater so in theory you’d have phone data you can flip on and off with a switch.
- darksaints 4y ago
  If you have some sort of example of amateur or unlicensed spectrum that is more starved for bandwidth than the mobile phones that 300m Americans spend an average of 5hrs a day using, I’d love to hear your ideas.
  - Retric 4y ago
    Mobile phone aren’t bandwidth staved, they are generally using much larger cells than needed. It’s just a tradeoff where handing them more spectrum reduces infrastructure costs not really performance for most users.
  - user3939382 4y ago
    > the mobile phones that 300m Americans spend an average of 5hrs a day using Current adoption and technology has been shaped by precisely the corporate dominance of the spectrum I'm referring to. In light of that, there's a circular implication to this point you're making. Let's imagine a future where mobile data is fueled by citizen-run mesh/P2P networks. Who truly knows what's possible (not just in tech terms, but adoption/behavior) until it happens, but we can be sure what won't be possible if we (the People) don't even have the legal access to experiment. Intersecting with that issue -- it's not just about "starved for bandwidth". Different bands have distinct propagation characteristics that make them suitable for different purposes, so the variation is important too.
    - darksaints 4y ago
      Amateur and unlicensed spectrum allocations have also grown over time as technology has allowed for tighter bandpass filtering and more efficient digital transmission…but we haven’t seen an amateur resurgence, and mesh networks are actually dying off. Nobody cares. And legal access to experiment is already free and available to everybody. It’s called a Special Temporary Authorization. Corporations use them all of the time for various purposes, including experimental applications. Citizens are allowed to apply for them too, but nobody ever does. I don’t really care about hypothetical future scenarios that will never exist. Unlicensed and amateur spectrum has its place, but it’s not exactly deserving of any more bandwidth than it already has.
TradingPlaces 4y ago
Full charts: https://ntia.gov/sites/default/files/publications/january_2016_spectrum_wall_chart_0.pdf https://ntia.gov/sites/default/files/publications/january_20...
- ehPReth 4y ago
  ooh this is neat. is there a Canadian version like this that anyone knows of?
  - mardifoufs 4y ago
    Yes! Here is a picture of the chart: http://canadianspectrumpolicyresearch.org/wp-content/uploads/2016/08/2014_Canadian_Radio_Spectrum_Chart.jpg http://canadianspectrumpolicyresearch.org/wp-content/uploads... And here is the original document from Industry Canada, in PDF but with a much higher resolution: https://www.ic.gc.ca/eic/site/smt-gst.nsf/vwapj/2014_Canadian_Radio_Spectrum_Chart.pdf/$file/2014_Canadian_Radio_Spectrum_Chart.pdf https://www.ic.gc.ca/eic/site/smt-gst.nsf/vwapj/2014_Canadia... (This is the 2014 version so it might not be exactly accurate anymore, but I'm sure you can find more recent versions from Industry Canada)
    - ehPReth 4y ago
      amazing, thank you! Edit: here seems to be the latest (2018) version; a little bit less pretty at the top but still very cool: https://www.ic.gc.ca/eic/site/smt-gst.nsf/vwapj/2018_Canadian_Radio_Spectrum_Chart.PDF/$FILE/2018_Canadian_Radio_Spectrum_Chart.PDF https://www.ic.gc.ca/eic/site/smt-gst.nsf/vwapj/2018_Canadia... (via https://ised-isde.canada.ca/site/spectrum-management-telecommunications/en/learn-more/key-documents/canadian-frequency-allocations-table-and-chart/canadian-table-frequency-allocations https://ised-isde.canada.ca/site/spectrum-management-telecom...)
      - MichaelZuo 4y ago
        It's interesting that Canada decides to regulate from 8.75 Hz on up compared to 9 Hz for the U.S. Also, does anyone know why 275 GHz is the cutoff?
EarthIsHome 4y ago
Another fun, somewhat related poster from 1944: Chart of Electromagnetic Radiations [0], and a "color-corrected" version [1]. [0]: https://www.flickr.com/photos/llnl/9403051123 https://www.flickr.com/photos/llnl/9403051123 [1]: https://www.flickr.com/photos/acme-laboratories/31849902131 https://www.flickr.com/photos/acme-laboratories/31849902131
- barbazoo 4y ago
  I love this chart and would like to print it. Can anyone gauge if this is still somewhat current or if there's a better one?
  - kzrdude 4y ago
    It's a lovely chart. Your question is a bit fun, since the chart is clearly old and that's part of its charm isn't it? I scanned through it looking for any obvious errors or things we've changed our understanding of a lot since then. There's one picture of using Radium radiation in hospital treatments that seems very old-fashioned.
  - deleted 4y ago
    [deleted]
  - deleted 4y ago
    [deleted]
  - retrac 4y ago
    It is copyright 1944. So it rather charmingly hand-waves away frequencies above 10 MHz or so. Such frequencies will be useful for television! And the plot stops at 100 MHz. (Nearly all radio used today is above 100 MHz.) That said, much does still hold true. Longwave is still used by giant shore installations to communicate with ships. (Mostly by coincidence. Long wavelengths can reach submerged submarines.) The aeronautic band is still used by aeronautic non-directional beacons. The AM broadcast band is still AM broadcast. Some of the amateur bands are still in the same place today. The physics and electronics depicted seem accurate. Its creators were clearly informed of the cutting edge in the 1940s; it depicts a magnetron, which had been invented about a decade before, and not widely used until high-power models were developed and then applied to radar c. 1940. A section about the health effects of ionizing radiation is conspicuously absent to my modern eye.
IIAOPSW 4y ago
I'm currently going through a bit of a transit map obsession, and these frequency allocation charts just feel like they tickle the same feeling. The way it codes information densely, into simple colors, in easily understood ways. Even the part where it distorts things slightly in order to depict them cleanly echos the way subway and metro maps often fudge geographical features to make their maps more readable. I wonder if there's anything one of these diagrams can copy from the other. Maybe the radio spectrum would make more sense if organized into "lines" of some sort
- mlsu 4y ago
  I have the same obsession, I think. Do you know of any place that sells high quality printed maps or charts, with (for lack of a better word) "engineering" data? I'm particularly interested in energy, transit, or natural resource maps and charts. Or even just a collection of nice looking, info-dense charts.
  - IIAOPSW 4y ago
    Nope sorry. Now that I look at this chart for a bit I realize its the radio equiv of the Vignelli map of NY subway. It looks nice, it feels like good design, but its actually unusable. The Y axis within each spectrum isn't used for any meaning other than just dividing into halves, thirds, quarters whatever. Sometimes there's two or more boxes of the same color and label in the same spectrum with no explanation about what distinguishes them. It color codes every minor distinction in application with its own color, which actually makes it less clear. Here's my first pass at a redesign. All the categories are reallocated into a 2-feature category system, (Sea, Land, Air, Space) x (Science, Navigation, Communication, Broadcast). The first half-category goes on the y axis of each spectrum bar. So all the space stuff is along the top of the sub-spectrum chart, all the sea stuff along the bottom. The second half category goes into a color, of which there's only 4. The existing color stripe for federal/non-federal is good as is, but could perhaps also include operator type more generally (military/civilian/government/public, reserved etc).
dr_dshiv 4y ago
Back in the early 00s, the “Digital Promise” org sought to set aside some spectral “land” to support digital education, just as the western reserve set aside land for public education. I thought it was a brilliant idea. https://today.duke.edu/2001/04/digpromise406.html https://today.duke.edu/2001/04/digpromise406.html
- bmelton 4y ago
  Meanwhile, in the late 00s,federal agencies were selling their emergency spectrum allocations to the highest bidder (and apparently still are as of 2021) https://www.ntia.doc.gov/files/ntia/publications/fifth_annual_report_1710-1755mhz_03302012.pdf https://www.ntia.doc.gov/files/ntia/publications/fifth_annua...
  - blitzar 4y ago
    The Biggest Auction Ever: The Sale of the British 3G Telecom Licences https://www.jstor.org/stable/798361 https://www.jstor.org/stable/798361 What a time to be alive the early 00's were - where the possibilities of 3G was endless along with the profits. £22 billion for 3G on a tiny island was real money in 2000, and a lot more than the £2.3 billion or so they managed in 2014 for 4G and £1.3 billion in 2018 for 5G
Dylan16807 4y ago
How do you find the regions wifi uses on this chart? I can't really find any correlation even knowing the frequencies. Or is that somehow not in scope?
- darken 4y ago
  I believe they fall under the "amateur" bands. I.e. frequencies not requiring a license to utilize (given you obey given power limits). That's why the same frequencies are shared by WiFi, Bluetooth, ZigBee, etc. Some of the amateur bands also overlap with allocations for things like radar. For example, a subset of the "5Ghz" WiFi channels (the "DFS" channels) can only be used if the access point will auto switch to a different channel upon detecting a radar pulse.
  - Dylan16807 4y ago
    But if I go look between 5 and 5.6 GHz I don't see any mention of "amateur". That's where most of the 5GHz range is.
  - vvoid 4y ago
    I believe you're thinking of the ISM bands - problematic chunks of the spectrum that are given over to industrial, scientific and medical technologies that emit RF by design. The FCC allows a bit of part 15 free-market anarchy on these bands so long as manufacturers limit power and print a familiar disclaimer on the device. By contrast, the amateur radio service does require a license. This is actually a chart that shows who is legally protected from interference. A license holder of a service listed in a colored bar has the right to complain if there is another emission on their spectrum. (There are also "primary" and "secondary" users for some ranges, the latter expected to yield to the former). According to that chart, a radiolocation service is the primary user. Amateurs can then work around them (1.5KW earth-moon-earth wifi anyone?) and finally wifi is allowed to exist with all the other random gadgets. Yes, WiFi is given nearly the lowest priority for a small slice of the spectrum that is full of garbage from other users. No wonder it's so good at beamforming, spread spectrum use, channel hopping, and so on.
  - tesseract 4y ago
mcint 4y ago
I was searching for this just last night, thanks! Though ideally an interactive one, with zoom and some capacity for search and for personal annotation.
raldi 4y ago
Before clicking, I thought it was going to look like the IP allocation charts (or Colorado River water rights), with some areas fighting for crumbs and other older stakeholders massively overprovisioned, but this actually looks quite reasonable to me.
mensetmanusman 4y ago
An old lab I worked in had a malfunctioning RF power supply for a vacuum plasma generator. None of the researchers were cognizant of the fact it was spewing noise outside its frequency allocation until some relevant government agencies quickly visited and had it shut down. We were impressed with the response time :)
- geerlingguy 4y ago
  The FCC used to have specialty cars with spectrum analyzers and complex directional antennas built into the roof to quickly triangulate rogue signals. Not sure if that's still done these days but I'm sure with GPS receivers and a couple mobile units, a position could be pinpointed very quickly.
  - livueta 4y ago
    Fun fact about modern radio direction-finding techniques: you don't need directional antennas, just an array of antennas you can observe phase differences across. It works shockingly well. https://www.sciencedirect.com/science/article/pii/S1877050918320416 https://www.sciencedirect.com/science/article/pii/S187705091...
    - viraptor 4y ago
      That's got some usual Nyquist limitations, right? For high enough freqs you'll be able to identify the plane, but the direction will potentially alias?
      - red-iron-pine 4y ago
        It took em a lot longer than 1 hour, but yeah they definitely show up. "We only ask once"
  - anthomtb 4y ago
    If you infringe on a mobile carrier’s spectrum, for which they have paid a handsome dollar, you can expect to find a man with a Yagi antenna and frequency analyzer in your backyard within a couple hours.
raldi 4y ago
What does “FIXED” mean on these charts?
- ranger207 4y ago
  The transmitter is at a fixed location, like a radio tower or satellite uplink antenna
klysm 4y ago
I just got this in poster form (surprisingly cheap) and love having it up on the wall
- poly_morphis 4y ago
  Any tips for putting it on the wall in a relatively neat fashion? I want to hang more stuff on my walls in general, but I care about appearance.
  - red-iron-pine 4y ago
    take it to a framing store and have them mount it on foamcore or some other sort of light backing. usually will have a small hook in the back, sometimes more -- ask them them about it. then, small nails.
ComputerGuru 4y ago
Czechia has this really cool website that lets you identify what every frequency band is used for in depth [0]; it seems to be run by a telecom so I'm presuming its fairly correct and up-to-date. I don't know if there's something like that for the United States. [0]: https://spektrum.ctu.cz/en/band/387-390-mhz https://spektrum.ctu.cz/en/band/387-390-mhz
ComputerGuru 4y ago
I don't know what to make of the bands that they show. e.g. in the USA, garage door openers listen in the 300-390MHz range (depending on brand), but per the chart these are blocked off as "Federal-Exclusive" bands and detailed as for FIXED or MOBILE use (with a band for AERONAUTICAL RADIONAVIGATION in the middle). As a garage door opener owner/operator isn't licensed, it woudn't qualify as FIXED (though the transmitter wouldn't be fixed in all cases) and it certainly wouldn't qualify as "Federal-Exclusive." (They're not in the ISM spectrum [0].) [0]: https://en.wikipedia.org/wiki/ISM_radio_band#Frequency_allocations https://en.wikipedia.org/wiki/ISM_radio_band#Frequency_alloc...
- tjohns 4y ago
  Many of those devices are operating under the FCC's Part 15 rules for unlicensed transmitters, which allows them to use certain bands provided that they stay below a minimum power level (or use an inefficient antenna) and don't cause interference to licensed users. The idea is that by keeping the radiated field sufficiently weak, you avoid long-distance propagation and won't interfere with anything not in your immediate vicinity. This is why your garage door opener only works when you're right next to your house. (Compare with a licensed mobile radio, which will easily transmit 100-300 miles given a clear line of sight.)
- vitaflo 4y ago
  This chart doesn't show all of the frequency allocations. It's mostly showing who has priority on said frequency and who has secondary rights to not interfere with the frequency priority. There's a third "level" (you can look it up on the FCC's website if you like) that includes things that have low priority (any of the items listed in the chart above supersede them) and are normally low enough power that they will not cause any interference to the primary or secondary frequency holders in the chart. This is why you don't see things like wifi or garage door openers in the chart, but they are part of the band plan, usually under "RF Devices" which falls under Part 15 of the FCC's Code of Regulations.
Audiolite 4y ago
Building on this, although frequency allocation charts are aesthetically pleasing, they are cumbersome to use for research or determining what frequencies are allocated to what services. In practice, simple table formatting provides the easiest way look at allocations and compare country by country. One main reason is that allocations are accompanied by footnotes that provide further clarification for how each frequency band can or should be used. For instance, footnote US334 states that the in the bands 17.8 GHz to 20.2 GHz, fixed-satellite services transmitting from space to earth via geostationary and non-geostationary satellites may be authorized on a primary basis. For people/companies looking to provide services, this is the difference between being able to operate in a band and not. Additionally, it’s simply much more practical to look through and filter a table of allocations. As an example, this very simple site allows for easy comparison’s between the allocation tables of 25+ countries: https://spectrumdatabase.io/ https://spectrumdatabase.io/. It’s not as pretty, but it’s more practical. Either way, it’s great to see people interested in frequency allocations!
- thrdbndndn 4y ago
  ..but it doesn't even have the US?
  - cptcobalt 4y ago
    the US isn't the only country! (but it should have the US, and others; EU country representation is also thin)
supernova87a 4y ago
I would love to know if there's a $ per spectrum bandwidth overlay that can be made on this chart and if there are any interesting observations from that?
e-dant 4y ago
That’s a holiday sweater. Not a well-designed. Which is why it looks nice. Very human.
Animats 4y ago
I hadn't seen one of those in a while. It's now full all the way up to 300GHz. The last time I saw that chart, there was little if anything above 100Ghz. Terahertz, here we come![1] Incidentally, radio regulation, by international agreement, ends at 3 THz. Above that, it's called "light". [1] https://docs.fcc.gov/public/attachments/DOC-356588A1.pdf https://docs.fcc.gov/public/attachments/DOC-356588A1.pdf
- avar 4y ago
  > radio regulation, by international agreement, ends at 3 THz. Above that, it's called "light". That's true, but it's also tautological. If you gave an intelligent but blind alien the task of describing our international radio regulation they'd probably put the visible signal lights on airplanes and ships under the same umbrella as WiFi or FM radio. In reality visible light is also highly regulated, and in much the same way as the radio spectrum.
  - matthewmcg 4y ago
    Is visible light really regulated in the same way as radio? Certainly there aren't frequency allocations or licenses as we'd think of for radio. The regulations I am aware of relate to safety (laser precautions or FAA requiring markers on tall structures, e.g.), public nuisance, or environmental protection (e.g. for protection of sea turtles or light pollution reduction).
    - avar 4y ago
      It looks like the details are behind some paywall, but my first thought was whether visual morse code signalling at sea was standardized. From [1] and [2] it turns out it is, but I don't know in what detail. Overall it's probably not as formal as the radio spectrum in being regulated by international convention, but US and EU regulation is a de-facto standard when it comes to things like any external lights on cars, ships, airplanes and other vehicles. Just counting headlights, tail lights, break lights and indicators the average car has at least 10 different sources of light. If you own a car that number of "visual radio" transmitters[3] on your car alone probably outnumbers that other transmission devices you might have, and certainly if we account for "signal strength" (your bluetooth headphones probably don't have a range of many miles, but a car will easily "transmit" light over that distance). 1. https://www.ysmarines.com/marine-lighting/cxd7-cxd7-b-type-morse-code-light/ https://www.ysmarines.com/marine-lighting/cxd7-cxd7-b-type-m... 2. https://www.imo.org/en/OurWork/Safety/Pages/Preventing-Collisions.aspx https://www.imo.org/en/OurWork/Safety/Pages/Preventing-Colli... 3. Radio just being another form of light, and (in this example) light being another form of radio.
derefr 4y ago
Question for the audience: which parts of these allocations are actually fiat decisions made by each country; which parts are actually global decisions (where as soon as someone starts using it for X, every other country is stuck with that band being polluted with X, so they may as well use it for X as well); and which parts aren't decisions at all, but are just "the only possible frequency-band that kind of thing would work well on"?
- tjohns 4y ago
  Global decisions are made by treaty, through a United Nations organization known as the ITU. Some allocations are harmonized globally. Others are divided up into one of three global regions - roughly the Americas, Europe/Africa, and Asia/Oceania. Then these are further divided into one of 90 zones that roughly follow country-specific boundaries. All of this is decided very bureaucratically. In some cases decisions are constrained by the laws of physics (HF signals are going to bounce across the globe), in other cases by practical necessity (aviation/maritime allocations are harmonized to facilitate global movement of vessels, satellites are going to orbit across the globe). However, in some cases allocations will differ between ITU regions or zones (especially local broadcast and land-mobile communications users). Further, priority is usually given on a first-come/first-served basis, but harmonization is encouraged. Individual countries can modify their local allocations, provided this don't interfere with other global users. You can view the global allocations by looking up the ITU Radio Regulations, Article 5. (PDF here: https://www.itu.int/pub/R-REG-RR-2020 https://www.itu.int/pub/R-REG-RR-2020) If you're curious about the process behind all this, look up the World Radiocommunication Conference, which is held every ~3 years: https://en.wikipedia.org/wiki/World_Radiocommunication_Conference https://en.wikipedia.org/wiki/World_Radiocommunication_Confe...
  - derefr 4y ago
    I presume that while "this is decided very bureaucratically", there are at least some use-cases where the use-case preceded the formation of any multilateral body to coordinate usage, and so is essentially "grandfathered in" where the ITU (or any predecessor body) said "I guess we're stuck with that." That's more the case I was curious about with the second one. Also — and this is sort of a hybrid case of "grandfathered in" and "practical necessity" — I presume that, despite the ITU making no ruling on such, the band centered around 2.45GHz has ended up being "commercial use" in pretty much every country? My thinking being that it is the lowest-cost-to-generate dielectric frequency for cooking food, so microwave ovens almost exclusively use that frequency; and microwave ovens are common in pretty much every country (or is there a country that outlaws microwave ovens?); so the local regulatory body of each country is inevitably stuck with that radio interference source on that band, mucking it up for any "dedicated, clear-channel" licensed use; and so they may as well give that band away to industry, to come up with noise-tolerant use-cases for it.
belter 4y ago
"The European table of frequency allocations and applications in the frequency range 8.3 kHz to 3000 GHz." https://docdb.cept.org/document/593 https://docdb.cept.org/document/593 [PDF] - https://docdb.cept.org/download/4162 https://docdb.cept.org/download/4162 [Excel] - https://docdb.cept.org/download/4089 https://docdb.cept.org/download/4089

This crazy, beautiful chart illustrates the incredible complexity of managing one of our nation’s most crucial – and invisible – national assets: the radio spectrum.

user3939382 4y ago

The amount afforded to corporations vs unlicensed or amateur use gives you a good picture of how the power dynamics work in our “democracy” https://scholar.princeton.edu/sites/default/files/mgilens/files/gilens_and_page_2014_-testing_theories_of_american_politics.doc.pdf https://scholar.princeton.edu/sites/default/files/mgilens/fi...

dan-robertson 4y ago
Most of the allocations seem quite reasonable, eg lots of navigation, radio astronomy, etc, which don’t seem particularly corporate to me. I guess TV is corporate but there are a lot more people who watch rev than listen to amateur radio. Similarly people get pressure good use out of mobile phones. Plausibly it would be good if more of the spectrum was available for Wi-Fi. I guess one question is: are there amateur/unlicensed uses that are starved of bandwidth (Wi-Fi does strike me as something that fits but is there anything else)?
- Reason077 4y ago
  > "are the amateur/unlicensed uses that are starved of bandwidth (Wi-Fi does strike me as something that fits but is there anything else)?" WiFi 6e / WiFi 7 are getting a huge swath of bandwidth between 5.9 and 7.1Ghz in the US and Canada (but somewhat less in Europe/Japan/Australia/etc) Even with current 5 Ghz WiFi, a lot of routers seem to not let you select the DFS/TPC channels above 48 even though they're perfectly legal to use in most places. As a result, those channels are far less congested.
  - dan-robertson 4y ago
    I thought there was some tricky channel switching logic because of some other non-Wi-Fi uses of part of the 5GHz band, so maybe service degradation when switching away or just disabling the channels for a long time when the conflict-detection fires causes those channels to not be used much?
    - Reason077 4y ago
      I've certainly never noticed it switch channels on me in all the years I've been using it in the UK.
  - varenc 4y ago
    The DFS channels have big downsides though. I don’t know much about TPC but for DFS, if your access point is on a DFS channel and it detects weather radar usage there it has to immediately get off it. It also has a slow start up period where it must first listen for radar traffic before transmitting. Though if you’re in an area without any radar on those bands it could be well worth it.
    - Reason077 4y ago
      Yeah, it does increase boot time a bit while the initial scan happens. But hopefully you aren't rebooting your router too often anyway. Small price to pay for avoiding WiFi congestion if you're in a busy building/area. It's a huge performance penalty if some other nearby network is sharing your channel, so DFS is one small downside for a very big upside, IMO!
    - wtallis 4y ago
      In the US, it's only one specific type of weather radar (TDWR), which is only used at 45 major airports. If you don't live near one of those, you only have to worry about a false positive in the radar detection feature accidentally knocking you off a DFS channel. And I know from experience that local topography sometimes means you can be operating an AP on a DFS channel only a few miles from one of those airports without ever having a problem.
tptacek 4y ago
https://www.chapman.edu/esi/wp/porter-smith-hazlett-radiospectrum.pdf https://www.chapman.edu/esi/wp/porter-smith-hazlett-radiospe...
- user3939382 4y ago
  It's well-written but I totally disagree. Coase's prescription of auctions is precisely the means by which the People have had huge portions of the spectrum hijacked by megacorporations that they, in turn, use to extract rents from the public, while we get some overcrowded crumbs for our own use. This market-based analysis, which is typical, omits the factor of nearly complete regulatory capture, i.e. our reality. > Coase anticipated that full, fair, well-informed evaluations would find that decentralized resource owners generally outperformed state diktat. That omission is pervasive, as if "state diktat" is some force independent of these same resource owners.
  - kortilla 4y ago
    Is it regulatory capture or an auction? Those things aren’t related and they are kinda opposing. Regulatory capture would prevent entrants from even having the option to bid for spectrum.
    - user3939382 4y ago
      The auctions pit average citizens individually against the resources of megacorporations. Obviously it’s no match, the outcome of that contest will inevitably be what we have now. The point I’m making is pretty simple which is merely that the public deserves way more unlicensed and amateur spectrum. The government serves the types of corporations participating in these auctions, to the exclusion of the People, so that’s probably not ever changing.
      - MichaelZuo 4y ago
        The point of any auction is to determine who 'deserves' what. Your reversing cause and effect. And it's not like every auction winner is guaranteed to make money, there are cases where they overbid and ended up losing money, to the benefit of the regulator, which is indirectly benefiting the taxpayer.
pphysch 4y ago
See also IP address allocation and DNS (TLD) allocation. Hierarchy is something like: 1. US military/intelligence 2. Transnational corporations 3. Other large orgs/governments (distant) 4. People
Panzer04 4y ago
In practice do we need more reserved/unallocated bands? The problem with unlicensed bands is interference and the like - they can't be used together without stomping eachother (eg. in FPV RC, analog and digital transmitters have difficulties because digital stomps the analog signals). Arguably given the above it would be useful to have a larger range of frequencies available to amateur/unregulated users, but it's also probably true that the general public gets more utility from more 4G LTE spectrum, if we're honest.
mensetmanusman 4y ago
You can operate in any frequency so long as you are in a faraday cage :)
- user3939382 4y ago
  True. They have RF blocking paint and window films. I’ve always been curious to see how far I could get creating one in a normal looking room. I was thinking of combining this with a 4G repeater so in theory you’d have phone data you can flip on and off with a switch.
darksaints 4y ago
If you have some sort of example of amateur or unlicensed spectrum that is more starved for bandwidth than the mobile phones that 300m Americans spend an average of 5hrs a day using, I’d love to hear your ideas.
- Retric 4y ago
  Mobile phone aren’t bandwidth staved, they are generally using much larger cells than needed. It’s just a tradeoff where handing them more spectrum reduces infrastructure costs not really performance for most users.
- user3939382 4y ago
  > the mobile phones that 300m Americans spend an average of 5hrs a day using Current adoption and technology has been shaped by precisely the corporate dominance of the spectrum I'm referring to. In light of that, there's a circular implication to this point you're making. Let's imagine a future where mobile data is fueled by citizen-run mesh/P2P networks. Who truly knows what's possible (not just in tech terms, but adoption/behavior) until it happens, but we can be sure what won't be possible if we (the People) don't even have the legal access to experiment. Intersecting with that issue -- it's not just about "starved for bandwidth". Different bands have distinct propagation characteristics that make them suitable for different purposes, so the variation is important too.
  - darksaints 4y ago
    Amateur and unlicensed spectrum allocations have also grown over time as technology has allowed for tighter bandpass filtering and more efficient digital transmission…but we haven’t seen an amateur resurgence, and mesh networks are actually dying off. Nobody cares. And legal access to experiment is already free and available to everybody. It’s called a Special Temporary Authorization. Corporations use them all of the time for various purposes, including experimental applications. Citizens are allowed to apply for them too, but nobody ever does. I don’t really care about hypothetical future scenarios that will never exist. Unlicensed and amateur spectrum has its place, but it’s not exactly deserving of any more bandwidth than it already has.

TradingPlaces 4y ago

Full charts: https://ntia.gov/sites/default/files/publications/january_2016_spectrum_wall_chart_0.pdf https://ntia.gov/sites/default/files/publications/january_20...

ehPReth 4y ago
ooh this is neat. is there a Canadian version like this that anyone knows of?
- mardifoufs 4y ago
  Yes! Here is a picture of the chart: http://canadianspectrumpolicyresearch.org/wp-content/uploads/2016/08/2014_Canadian_Radio_Spectrum_Chart.jpg http://canadianspectrumpolicyresearch.org/wp-content/uploads... And here is the original document from Industry Canada, in PDF but with a much higher resolution: https://www.ic.gc.ca/eic/site/smt-gst.nsf/vwapj/2014_Canadian_Radio_Spectrum_Chart.pdf/$file/2014_Canadian_Radio_Spectrum_Chart.pdf https://www.ic.gc.ca/eic/site/smt-gst.nsf/vwapj/2014_Canadia... (This is the 2014 version so it might not be exactly accurate anymore, but I'm sure you can find more recent versions from Industry Canada)
  - ehPReth 4y ago
    amazing, thank you! Edit: here seems to be the latest (2018) version; a little bit less pretty at the top but still very cool: https://www.ic.gc.ca/eic/site/smt-gst.nsf/vwapj/2018_Canadian_Radio_Spectrum_Chart.PDF/$FILE/2018_Canadian_Radio_Spectrum_Chart.PDF https://www.ic.gc.ca/eic/site/smt-gst.nsf/vwapj/2018_Canadia... (via https://ised-isde.canada.ca/site/spectrum-management-telecommunications/en/learn-more/key-documents/canadian-frequency-allocations-table-and-chart/canadian-table-frequency-allocations https://ised-isde.canada.ca/site/spectrum-management-telecom...)
    - MichaelZuo 4y ago
      It's interesting that Canada decides to regulate from 8.75 Hz on up compared to 9 Hz for the U.S. Also, does anyone know why 275 GHz is the cutoff?

EarthIsHome 4y ago

Another fun, somewhat related poster from 1944: Chart of Electromagnetic Radiations [0], and a "color-corrected" version [1]. [0]: https://www.flickr.com/photos/llnl/9403051123 https://www.flickr.com/photos/llnl/9403051123 [1]: https://www.flickr.com/photos/acme-laboratories/31849902131 https://www.flickr.com/photos/acme-laboratories/31849902131

barbazoo 4y ago
I love this chart and would like to print it. Can anyone gauge if this is still somewhat current or if there's a better one?
- kzrdude 4y ago
  It's a lovely chart. Your question is a bit fun, since the chart is clearly old and that's part of its charm isn't it? I scanned through it looking for any obvious errors or things we've changed our understanding of a lot since then. There's one picture of using Radium radiation in hospital treatments that seems very old-fashioned.
- deleted 4y ago
  [deleted]
- deleted 4y ago
  [deleted]
- retrac 4y ago
  It is copyright 1944. So it rather charmingly hand-waves away frequencies above 10 MHz or so. Such frequencies will be useful for television! And the plot stops at 100 MHz. (Nearly all radio used today is above 100 MHz.) That said, much does still hold true. Longwave is still used by giant shore installations to communicate with ships. (Mostly by coincidence. Long wavelengths can reach submerged submarines.) The aeronautic band is still used by aeronautic non-directional beacons. The AM broadcast band is still AM broadcast. Some of the amateur bands are still in the same place today. The physics and electronics depicted seem accurate. Its creators were clearly informed of the cutting edge in the 1940s; it depicts a magnetron, which had been invented about a decade before, and not widely used until high-power models were developed and then applied to radar c. 1940. A section about the health effects of ionizing radiation is conspicuously absent to my modern eye.

IIAOPSW 4y ago

I'm currently going through a bit of a transit map obsession, and these frequency allocation charts just feel like they tickle the same feeling. The way it codes information densely, into simple colors, in easily understood ways. Even the part where it distorts things slightly in order to depict them cleanly echos the way subway and metro maps often fudge geographical features to make their maps more readable. I wonder if there's anything one of these diagrams can copy from the other. Maybe the radio spectrum would make more sense if organized into "lines" of some sort

mlsu 4y ago
I have the same obsession, I think. Do you know of any place that sells high quality printed maps or charts, with (for lack of a better word) "engineering" data? I'm particularly interested in energy, transit, or natural resource maps and charts. Or even just a collection of nice looking, info-dense charts.
- IIAOPSW 4y ago
  Nope sorry. Now that I look at this chart for a bit I realize its the radio equiv of the Vignelli map of NY subway. It looks nice, it feels like good design, but its actually unusable. The Y axis within each spectrum isn't used for any meaning other than just dividing into halves, thirds, quarters whatever. Sometimes there's two or more boxes of the same color and label in the same spectrum with no explanation about what distinguishes them. It color codes every minor distinction in application with its own color, which actually makes it less clear. Here's my first pass at a redesign. All the categories are reallocated into a 2-feature category system, (Sea, Land, Air, Space) x (Science, Navigation, Communication, Broadcast). The first half-category goes on the y axis of each spectrum bar. So all the space stuff is along the top of the sub-spectrum chart, all the sea stuff along the bottom. The second half category goes into a color, of which there's only 4. The existing color stripe for federal/non-federal is good as is, but could perhaps also include operator type more generally (military/civilian/government/public, reserved etc).

dr_dshiv 4y ago

Back in the early 00s, the “Digital Promise” org sought to set aside some spectral “land” to support digital education, just as the western reserve set aside land for public education. I thought it was a brilliant idea. https://today.duke.edu/2001/04/digpromise406.html https://today.duke.edu/2001/04/digpromise406.html

bmelton 4y ago
Meanwhile, in the late 00s,federal agencies were selling their emergency spectrum allocations to the highest bidder (and apparently still are as of 2021) https://www.ntia.doc.gov/files/ntia/publications/fifth_annual_report_1710-1755mhz_03302012.pdf https://www.ntia.doc.gov/files/ntia/publications/fifth_annua...
- blitzar 4y ago
  The Biggest Auction Ever: The Sale of the British 3G Telecom Licences https://www.jstor.org/stable/798361 https://www.jstor.org/stable/798361 What a time to be alive the early 00's were - where the possibilities of 3G was endless along with the profits. £22 billion for 3G on a tiny island was real money in 2000, and a lot more than the £2.3 billion or so they managed in 2014 for 4G and £1.3 billion in 2018 for 5G

Dylan16807 4y ago

How do you find the regions wifi uses on this chart? I can't really find any correlation even knowing the frequencies. Or is that somehow not in scope?

darken 4y ago
I believe they fall under the "amateur" bands. I.e. frequencies not requiring a license to utilize (given you obey given power limits). That's why the same frequencies are shared by WiFi, Bluetooth, ZigBee, etc. Some of the amateur bands also overlap with allocations for things like radar. For example, a subset of the "5Ghz" WiFi channels (the "DFS" channels) can only be used if the access point will auto switch to a different channel upon detecting a radar pulse.
- Dylan16807 4y ago
  But if I go look between 5 and 5.6 GHz I don't see any mention of "amateur". That's where most of the 5GHz range is.
- vvoid 4y ago
  I believe you're thinking of the ISM bands - problematic chunks of the spectrum that are given over to industrial, scientific and medical technologies that emit RF by design. The FCC allows a bit of part 15 free-market anarchy on these bands so long as manufacturers limit power and print a familiar disclaimer on the device. By contrast, the amateur radio service does require a license. This is actually a chart that shows who is legally protected from interference. A license holder of a service listed in a colored bar has the right to complain if there is another emission on their spectrum. (There are also "primary" and "secondary" users for some ranges, the latter expected to yield to the former). According to that chart, a radiolocation service is the primary user. Amateurs can then work around them (1.5KW earth-moon-earth wifi anyone?) and finally wifi is allowed to exist with all the other random gadgets. Yes, WiFi is given nearly the lowest priority for a small slice of the spectrum that is full of garbage from other users. No wonder it's so good at beamforming, spread spectrum use, channel hopping, and so on.
- tesseract 4y ago

mcint 4y ago

I was searching for this just last night, thanks! Though ideally an interactive one, with zoom and some capacity for search and for personal annotation.

raldi 4y ago

Before clicking, I thought it was going to look like the IP allocation charts (or Colorado River water rights), with some areas fighting for crumbs and other older stakeholders massively overprovisioned, but this actually looks quite reasonable to me.

mensetmanusman 4y ago

An old lab I worked in had a malfunctioning RF power supply for a vacuum plasma generator. None of the researchers were cognizant of the fact it was spewing noise outside its frequency allocation until some relevant government agencies quickly visited and had it shut down. We were impressed with the response time :)

geerlingguy 4y ago
The FCC used to have specialty cars with spectrum analyzers and complex directional antennas built into the roof to quickly triangulate rogue signals. Not sure if that's still done these days but I'm sure with GPS receivers and a couple mobile units, a position could be pinpointed very quickly.
- livueta 4y ago
  Fun fact about modern radio direction-finding techniques: you don't need directional antennas, just an array of antennas you can observe phase differences across. It works shockingly well. https://www.sciencedirect.com/science/article/pii/S1877050918320416 https://www.sciencedirect.com/science/article/pii/S187705091...
  - viraptor 4y ago
    That's got some usual Nyquist limitations, right? For high enough freqs you'll be able to identify the plane, but the direction will potentially alias?
    - red-iron-pine 4y ago
      It took em a lot longer than 1 hour, but yeah they definitely show up. "We only ask once"
- anthomtb 4y ago
  If you infringe on a mobile carrier’s spectrum, for which they have paid a handsome dollar, you can expect to find a man with a Yagi antenna and frequency analyzer in your backyard within a couple hours.

raldi 4y ago

What does “FIXED” mean on these charts?

ranger207 4y ago
The transmitter is at a fixed location, like a radio tower or satellite uplink antenna

klysm 4y ago

I just got this in poster form (surprisingly cheap) and love having it up on the wall

poly_morphis 4y ago
Any tips for putting it on the wall in a relatively neat fashion? I want to hang more stuff on my walls in general, but I care about appearance.
- red-iron-pine 4y ago
  take it to a framing store and have them mount it on foamcore or some other sort of light backing. usually will have a small hook in the back, sometimes more -- ask them them about it. then, small nails.

ComputerGuru 4y ago

Czechia has this really cool website that lets you identify what every frequency band is used for in depth [0]; it seems to be run by a telecom so I'm presuming its fairly correct and up-to-date. I don't know if there's something like that for the United States. [0]: https://spektrum.ctu.cz/en/band/387-390-mhz https://spektrum.ctu.cz/en/band/387-390-mhz

ComputerGuru 4y ago

I don't know what to make of the bands that they show. e.g. in the USA, garage door openers listen in the 300-390MHz range (depending on brand), but per the chart these are blocked off as "Federal-Exclusive" bands and detailed as for FIXED or MOBILE use (with a band for AERONAUTICAL RADIONAVIGATION in the middle). As a garage door opener owner/operator isn't licensed, it woudn't qualify as FIXED (though the transmitter wouldn't be fixed in all cases) and it certainly wouldn't qualify as "Federal-Exclusive." (They're not in the ISM spectrum [0].) [0]: https://en.wikipedia.org/wiki/ISM_radio_band#Frequency_allocations https://en.wikipedia.org/wiki/ISM_radio_band#Frequency_alloc...

tjohns 4y ago
Many of those devices are operating under the FCC's Part 15 rules for unlicensed transmitters, which allows them to use certain bands provided that they stay below a minimum power level (or use an inefficient antenna) and don't cause interference to licensed users. The idea is that by keeping the radiated field sufficiently weak, you avoid long-distance propagation and won't interfere with anything not in your immediate vicinity. This is why your garage door opener only works when you're right next to your house. (Compare with a licensed mobile radio, which will easily transmit 100-300 miles given a clear line of sight.)
vitaflo 4y ago
This chart doesn't show all of the frequency allocations. It's mostly showing who has priority on said frequency and who has secondary rights to not interfere with the frequency priority. There's a third "level" (you can look it up on the FCC's website if you like) that includes things that have low priority (any of the items listed in the chart above supersede them) and are normally low enough power that they will not cause any interference to the primary or secondary frequency holders in the chart. This is why you don't see things like wifi or garage door openers in the chart, but they are part of the band plan, usually under "RF Devices" which falls under Part 15 of the FCC's Code of Regulations.

Audiolite 4y ago

Building on this, although frequency allocation charts are aesthetically pleasing, they are cumbersome to use for research or determining what frequencies are allocated to what services. In practice, simple table formatting provides the easiest way look at allocations and compare country by country. One main reason is that allocations are accompanied by footnotes that provide further clarification for how each frequency band can or should be used. For instance, footnote US334 states that the in the bands 17.8 GHz to 20.2 GHz, fixed-satellite services transmitting from space to earth via geostationary and non-geostationary satellites may be authorized on a primary basis. For people/companies looking to provide services, this is the difference between being able to operate in a band and not. Additionally, it’s simply much more practical to look through and filter a table of allocations. As an example, this very simple site allows for easy comparison’s between the allocation tables of 25+ countries: https://spectrumdatabase.io/ https://spectrumdatabase.io/. It’s not as pretty, but it’s more practical. Either way, it’s great to see people interested in frequency allocations!

thrdbndndn 4y ago
..but it doesn't even have the US?
- cptcobalt 4y ago
  the US isn't the only country! (but it should have the US, and others; EU country representation is also thin)

supernova87a 4y ago

I would love to know if there's a $ per spectrum bandwidth overlay that can be made on this chart and if there are any interesting observations from that?

e-dant 4y ago

That’s a holiday sweater. Not a well-designed. Which is why it looks nice. Very human.

Animats 4y ago

I hadn't seen one of those in a while. It's now full all the way up to 300GHz. The last time I saw that chart, there was little if anything above 100Ghz. Terahertz, here we come![1] Incidentally, radio regulation, by international agreement, ends at 3 THz. Above that, it's called "light". [1] https://docs.fcc.gov/public/attachments/DOC-356588A1.pdf https://docs.fcc.gov/public/attachments/DOC-356588A1.pdf

avar 4y ago
> radio regulation, by international agreement, ends at 3 THz. Above that, it's called "light". That's true, but it's also tautological. If you gave an intelligent but blind alien the task of describing our international radio regulation they'd probably put the visible signal lights on airplanes and ships under the same umbrella as WiFi or FM radio. In reality visible light is also highly regulated, and in much the same way as the radio spectrum.
- matthewmcg 4y ago
  Is visible light really regulated in the same way as radio? Certainly there aren't frequency allocations or licenses as we'd think of for radio. The regulations I am aware of relate to safety (laser precautions or FAA requiring markers on tall structures, e.g.), public nuisance, or environmental protection (e.g. for protection of sea turtles or light pollution reduction).
  - avar 4y ago
    It looks like the details are behind some paywall, but my first thought was whether visual morse code signalling at sea was standardized. From [1] and [2] it turns out it is, but I don't know in what detail. Overall it's probably not as formal as the radio spectrum in being regulated by international convention, but US and EU regulation is a de-facto standard when it comes to things like any external lights on cars, ships, airplanes and other vehicles. Just counting headlights, tail lights, break lights and indicators the average car has at least 10 different sources of light. If you own a car that number of "visual radio" transmitters[3] on your car alone probably outnumbers that other transmission devices you might have, and certainly if we account for "signal strength" (your bluetooth headphones probably don't have a range of many miles, but a car will easily "transmit" light over that distance). 1. https://www.ysmarines.com/marine-lighting/cxd7-cxd7-b-type-morse-code-light/ https://www.ysmarines.com/marine-lighting/cxd7-cxd7-b-type-m... 2. https://www.imo.org/en/OurWork/Safety/Pages/Preventing-Collisions.aspx https://www.imo.org/en/OurWork/Safety/Pages/Preventing-Colli... 3. Radio just being another form of light, and (in this example) light being another form of radio.

derefr 4y ago

Question for the audience: which parts of these allocations are actually fiat decisions made by each country; which parts are actually global decisions (where as soon as someone starts using it for X, every other country is stuck with that band being polluted with X, so they may as well use it for X as well); and which parts aren't decisions at all, but are just "the only possible frequency-band that kind of thing would work well on"?

tjohns 4y ago
Global decisions are made by treaty, through a United Nations organization known as the ITU. Some allocations are harmonized globally. Others are divided up into one of three global regions - roughly the Americas, Europe/Africa, and Asia/Oceania. Then these are further divided into one of 90 zones that roughly follow country-specific boundaries. All of this is decided very bureaucratically. In some cases decisions are constrained by the laws of physics (HF signals are going to bounce across the globe), in other cases by practical necessity (aviation/maritime allocations are harmonized to facilitate global movement of vessels, satellites are going to orbit across the globe). However, in some cases allocations will differ between ITU regions or zones (especially local broadcast and land-mobile communications users). Further, priority is usually given on a first-come/first-served basis, but harmonization is encouraged. Individual countries can modify their local allocations, provided this don't interfere with other global users. You can view the global allocations by looking up the ITU Radio Regulations, Article 5. (PDF here: https://www.itu.int/pub/R-REG-RR-2020 https://www.itu.int/pub/R-REG-RR-2020) If you're curious about the process behind all this, look up the World Radiocommunication Conference, which is held every ~3 years: https://en.wikipedia.org/wiki/World_Radiocommunication_Conference https://en.wikipedia.org/wiki/World_Radiocommunication_Confe...
- derefr 4y ago
  I presume that while "this is decided very bureaucratically", there are at least some use-cases where the use-case preceded the formation of any multilateral body to coordinate usage, and so is essentially "grandfathered in" where the ITU (or any predecessor body) said "I guess we're stuck with that." That's more the case I was curious about with the second one. Also — and this is sort of a hybrid case of "grandfathered in" and "practical necessity" — I presume that, despite the ITU making no ruling on such, the band centered around 2.45GHz has ended up being "commercial use" in pretty much every country? My thinking being that it is the lowest-cost-to-generate dielectric frequency for cooking food, so microwave ovens almost exclusively use that frequency; and microwave ovens are common in pretty much every country (or is there a country that outlaws microwave ovens?); so the local regulatory body of each country is inevitably stuck with that radio interference source on that band, mucking it up for any "dedicated, clear-channel" licensed use; and so they may as well give that band away to industry, to come up with noise-tolerant use-cases for it.

belter 4y ago

"The European table of frequency allocations and applications in the frequency range 8.3 kHz to 3000 GHz." https://docdb.cept.org/document/593 https://docdb.cept.org/document/593 [PDF] - https://docdb.cept.org/download/4162 https://docdb.cept.org/download/4162 [Excel] - https://docdb.cept.org/download/4089 https://docdb.cept.org/download/4089