What Will You Do With An Extra 1.2 Gigahertz?

While our collective minds have been turned towards the global pandemic it’s refreshing to hear that in some quarters life has continued, and events that would have made the news in more normal times have continued to take place while they have been replaced in coverage by more urgent considerations.

In the last few weeks there has been a piece of routine American bureaucracy that flew under the radar but which will have a significant effect on global technology; the United States’ Federal Communication Commission first proposed, then ratified, the allocation of an extra 1200 MHz of spectrum in the 6 GHz band to ISM usage. This allocation process is likely to be repeated by other regions worldwide, freeing up another significant piece of spectrum for unlicensed usage.

In practice this means that there will be a whole new set of WiFi channels created, and we’ll all have a little more spectrum to play around with, so it’s worth examining in a little more detail.

We Owe WiFi To The Microwave Oven

A Raytheon RadaRange microwave oven, on board the nuclear-powered NS Savannah
A Raytheon RadaRange microwave oven, on board the nuclear-powered NS Savannah. Acroterion / CC BY-SA 3.0.

The dry description of an ISM band, or to use its full terminology, industrial, scientific and medical, conceals a lengthy history and a load of unexpected frequency allocations and uses for the spectrum most of us simply associate only with wireless networking and maybe a few extra protocols such as LoRa or UHF remote control.

Their history goes back as far as the mid 20th century when they were set aside by the International Telecommunication Union as frequency allocations in which non-communication applications for radio could be pursued.

A particular application was to be RF heating, and the popular 2.4 GHz band first made an appearance with the brand-new technology of microwave ovens, which were in turn derived from wartime work on radar. Indeed a Raytheon employee invented a popular cooking gadget.

There were an array of different frequencies reserved as ISM bands, ranging from the HF bands through to the sub-millimetre microwaves, even though (or maybe because) the technology barely existed to make use of those higher frequencies at the time. Aside from microwave ovens, devices using the ISM bands found their way into the hands of consumer through the first generation of cordless home telephones, and in radio-controlled toys and models. There was a time when owning a model plane, car, or even fighting robot, meant also having a pack of crystals for each of the individual channels (usually 27 MHz or 40 MHz) in use.

A Lucent Orinoco WiFi card. This card's chipset appeared in a host of early WiFi cards. Shootthedevgru (Public domain)
A Lucent Orinoco WiFi card. This card’s chipset appeared in a host of early WiFi cards. Shootthedevgru (Public domain).

The turning point that led to the WiFi networks we have today came in 1985, when the FCC relaxed the rules to allow unlicensed use of the ISM bands within a set of guidelines, and in particular their use for spread-spectrum communication devices. After the development of the technology through a series of proprietary products, by the 1990s what would become the 802.11 series of standards appeared, and by the end of the decade everyone wanted a Lucent Orinoco PCMCIA card in their laptop.

We now have an array of WiFi channels across the 2.4 GHz and 5 GHz bands, and while the former is so congested as to have become degraded in some built-up areas, the latter has now become the well-used band of choice. The expansion in numbers of connected devices coupled with the explosion in IoT devices can only increase demand for wireless bandwidth, so the extra new space in the 6 GHz band can only be welcome.

Why Do We Have Wireless Networks We Don’t Use?

Olivetti's promotional image for their Net3 DECT network card
Olivetti’s promotional image for their Net3 DECT network card

Before rejoicing too much over the new allocation, it’s worth taking a look for a minute at the alternatives. The 2.4 GHz and 5 GHz bands are not the only ones in which consumer wireless networking has been deployed, so why can’t those other bands take up some of the slack? The answer lies in a complex combination of market forces and competing technologies: A promising product can fade into obscurity simply by arriving too early before the market has a need for it, or too late after the market has moved on.

DECT is an example of the former, while we know it today as a digital cordless phone standard it possesses all the characteristics of a 3G cellphone network, including a data channel. Sadly, it arrived in the early 1990s when mobile computing users had little need for a wireless network, so that side of its operation never saw significant use. Meanwhile 802.11ah is a WiFi standard for the 900 MHz ISM band that offers extended range that you might expect to be everywhere, but its late arrival on the scene caused it to be supplanted by other technologies. 802.11ah chipsets and modules are produced by some manufacturers, and given the right market conditions could be as plentiful as those for 2.4 GHz WiFi or LoRa, but due to low take-up they remain extremely rare.

The 24 extra 6 GHz channels that will be provided by the 802.11ax standard will therefore be a much needed addition to the existing allocations. But merely because they are there does not necessarily mean that they will see significant use. Just like the aforementioned 802.11ah it is possible that the market may have taken a different course by the time enough supported devices have been shipped to allow consumers to use it.

One of the promises of 5G mobile telephones, for example, is a future in which there is universal high speed connectivity. Will this remove the pressing need for extra WiFi in years to come? Or how about the upcoming 802.11bb so-called LiFi standard for light-based networking? Will a much cheaper LED light bulb on every ceiling make a WiFi router seem archaic? One thing is for certain, if you thought wireless networking was a done deal, you’re in for a surprise over the next few years.

27 thoughts on “What Will You Do With An Extra 1.2 Gigahertz?

  1. But will 24 channels be … 24 actual disparate channels? Or will it be the nonsense that we see with 5GHz where we have 150 channels, but oh wait we can’t use the middle ones, or the low ones, and oh wait everyone uses 16-channel-wide bands, so really we have a whopping 2 channels that can really be used – one in the low area (32 through 50), and one in the high area (147-163). Since I’m in an apartment building. 5GHz is just as uselessly congested as 2.4GHz is.

    1. 5 GHz doesn’t have 150 channels. They’re numbered 5 MHz apart, but the smallest channel width available is 20 MHz, which means you’ve only got ~30 or so 20 MHz channels. ISM bands are unlicensed, which means that except for power, they’re unrestricted – meaning, you’re going to have to coordinate with people to get the best usage. If there’s some central authority governing it… it’d be restricted, now wouldn’t it?

      The “oh wait you can’t use these” are because you need a WiFi 6 router with DFS, and enable it. With that enabled, there should be plenty of spectrum available, and if the 80 MHz channels are still too crowded (which… would be surprising) you can always step down to narrower ones and likely get equivalent throughput.

      In terms of your actual question, the “24 channels” are 24 20-MHz channels, or an additional 6 80 MHz wide channels (which are the “16-channel wide bands” you’re mentioning).

      1. I think part of why 802.11ah never went anywhere is that IP packets in 915MHz are a terrible idea if you just need basic IoT stuff.

        The OSI layered network model is a bit wasteful. Especially IPv6. There’s no reason to be sending sender, reciever, MAC, etc over such a limited amount of bandwidth.

        In fact, there’s no reason for long addresses are all, just a short “hint” to narrow things down. From there, you can just try to decrypt with every matching key, and if it doesn’t decrypt, then it’s not addressed to you.

        Bandwidth usage is more important to most people than elegant layered protocols.

        1. It’s definitely wasteful if you’re in a bandwidth-restricted environment like ~900 MHz at poor signal strength and sending small packets. For large packets it’s a pretty negligible overhead. In the 2.4/5 GHz world the WiFi overhead is pretty dominant over the Ethernet embedding for most use cases.

        2. If you really think that, I would encourage you to take part in IETF and ITU meetings where these standards are designed and discussed in excruciating detail. I can assure you, this stuff isn’t a) done in a vacuum, or b) without good reason.

          1. It’s done with good reason, but the reasons don’t always apply to typical home use cases, nor are the priorities always in line with a typical consumer.

            A large committee isn’t a guarantee that the standard is all that great, it just means that 100 different people asked for support for their obscure use case, and most likely, the high end manufacturers aren’t thinking “Ok, how will this work if we build it with crap parts, and a whole apartment building leaves it set to the default channel”.

            The bigger the company the more everyone seems to assume that conditions will be perfect. If everyone crowds the spectrum, not my problem. If I make a security error that makes the news in the process of trying to save a few bytes, I’m in trouble.

            Whereas on a smaller scale, everyone is used to thinking about imperfect conditions, and they aren’t always trying to handle things like perfect forward secrecy, nor do they need to be able to confidently explain it to business people that expect it to secure military secrets.

            Enterprise and everything else having different needs is a well known effect.

          2. “Ok, how will this work if we build it with crap parts, and a whole apartment building leaves it set to the default channel”

            I don’t understand – WiFi *does* work in that situation. Remarkably well, actually. Does it work ideally? Of course not, but that would require better negotiation between users than you can have in an unrestricted band.

            Just imagine you’re in floor 2, and floor 3 can’t hear floor 1, and vice versa, but you can hear both. You *can’t* make it such that the setup will downgrade 1 and 3 to allow for a user on 2 to get better throughput. It’s an unrestricted band. You’re always going to have more interference than they will. That’s life.

            You can design the protocol to do that, and you can say to the manufacturers “to advertise yourself as compatible with me, you need to do this” but you can’t force the end users to do it. And since it’ll actually make things better for some people, *some* manufacturer’s going to make it so that by default, it grabs everything. Pretty much the only thing you could do to prevent that would be to protect the protocol via patent or something and prevent them from selling something like that. Which likely would never be adopted in the first place.

  2. I think the early 802.11 standard included an optical element. It was frequency hopping, spread spectrum and optical.
    Also don’t forget IrDA protocol which allowed optical serial and even up to 4 Mbits/s and jvc did a vipslan that did 10 mbit or near enough optical Ethernet. Canon did 155mbit atm point to point (cano beam)

  3. Nowadays, few people think about this technology, which allows generating a steady stream of threats that will not come from people from firmware algorithms, which will lead to a new round of global crime. And the next 5-10 years will not be developed effective mechanisms to counter such threats.

  4. Interesting how the FCC “proposed, then ratified, the allocation of an extra 1200 MHz of spectrum in the 6 GHz band to ISM usage.” (Now after writing this whole comment, I realize it states “to ISM usage.”, that is legally not stating that it is an ISM band, just that it can be used for ISM applications within the USA.)

    When the ISM bands are defined by the ITU Radio Regulations. (ie it is set by the International Telecommunication Union) A union we got to hope likes the idea of another 1.2 GHz of spectrum being used for ISM applications. Or in this case, likely short range radio communication for things like WiFi and the like.

    The FCC can propose some new spectrum for ISM use. They can on a national level in the USA state that one can use the band for ISM applications, but they can’t make it an “ISM band” on their own. (Yes, the FCC is responsible for governing the ISM band’s proper usage in the USA.)

    Most ISM bands are internationally accepted, notable examples are:
    The 433MHz ISM band is though only accepted in Europe and Africa. (Not to mention being subject to local acceptance, so it isn’t applicable everywhere. Ie, 433 MHz transceivers aren’t legal everywhere, though Australia seems to have an exception allowing them.)
    And the 915 MHz band is only usable in the Americas, with some exceptions.

    Though, the ISM band is originally made for running things like induction heaters, high frequency TIG/MIG welders, among other high energy applications that tends to create a fair bit of interference.

    For an example the 2.45 GHz ISM band were only created thanks to the US delegat at the time (9th August 1947) saying that there is an electronic cooker that uses this frequency in existence that might see future use on trans Atlantic ships and airplanes, and it’s quite noisy… (That being everyone’s favorite WiFi and bluetooth jammer, the good old microwave oven.)

    The idea of using these bands for radio communication is a small loophole to be fair. And the ITU has accepted this loophole.
    Since the devices the ISM band were created for are rarely picky about EMI. (Considering that it is primarily high energy heating/welding applications.) Then the ISM bands are practically already designated as “here there be jamming!” so if someone wants to communicate over that, then feel free to try, but don’t be surprised to get jammed occasionally….

    (There is though usually a legal requirement to use spread spectrum technology to get more “immune” against said jamming, this is likely to just make it slightly harder for people to actually use ISM bands for RF communication. Since when this acceptance were proposed, Tele communication companies providing similar solutions in their own licensed spectrum got worried that their market were doomed and obviously complained…)

    Now, there is no such thing as an “ITU radio communication band” with a similar “license free” structure, but without all the high energy devices having practically free reign to use it. Though, a few such bands would be wonderful.

  5. Rats, I was hoping this was about how Intel managed to speed up their CPUs by 1.2GHz. I miss the years when clock speeds would actually increase by double-digit percentages.

    1. Until we either migrate away from silicon or workout how to continually cool a tiny area at near the temperature on the surface of the sun to room temperature, the current clock rates are probably not going to get much higher. (ref: https://www.researchgate.net/profile/Daniel_Etiemble/publication/323510528/figure/fig3/AS:599572166479874@1519960552851/Power-density-for-successive-nodes-B-Reducing-CPI-and-increasing-IPC-CPI-has-two.png )

      As we go smaller, on paper, we could clock faster, but we need to drop the voltages (slower switching speed) which reduce the currents (I squared R losses), because we have to maintain a constant power density (heat generated per until area on the silicon) that has been constant since around 2004. Maybe if we interleaved CPU’s that one get clocked at 10GHz for a few nanoseconds and then cools off for a few hundred nanoseconds before being put back into rotation again.

      The heat generated increases exponentially as the area decreases, maybe if there was a major breakthrough in cheap cryogenic cooling systems, the clock rates could be bumped up a bit.

  6. it’s all good and fine until you know what’s behind all of this. The reallocation of the C band spectrum is primarily about auction revenues and providing 5G spectrum to the cellular companies in a very long standing political sweetheart relationship. The source of the “new” spectrum is the highly reliable C band VSAT and point to point terrestrial frequencies. The VSAT frequencies are America’s only band which can supply high availability (99.99%) and are impervious to rain fade. Why is this important? Deepwater offshore oil platforms use C band primarily because of the ability to maintain communications during the severe storms to maintain the only communications links they have for telemetry, emergency shutdown and life safety communications. Without C band these platforms and vessels will have to use Ku band links which may have rain outages of sometimes hours at a time. C band terrestrial links are used to provide licensed high reliable (5 nines) point to point connectivity over typical distances of 30 to 50 miles for telecom backhaul out to rural communities which don’t have fiber.
    This is one of the many decisions the FCC has made based on political monkey business instead of proper spectrum management.
    They are also approving the failed lightsquared folks to fire up terrestrial service which the DoD says will interfere with the GPS system.
    Just recently a court ruled that the Commission could no longer hide evidence of fraudulent net neutrality public comments.
    The best thing that could be done is to freeze any major changes the current FCC makes until it gets a new c****man and this political nonsense can be replaced with solid technical decisions.
    Once these changes are made they will be so freaking hard to fix. IMHO

    1. It is indeed important to ensure that decisions are made properly.
      There is after all only X amount of spectrum, and it can’t really sustain all too much overlapped usage.

      An authority like the FCC sole responsibility is to ensure that the spectrum gets used efficiently, and also caters to the various needs of society. One can’t really just make decisions because “oh, this will be popular!”

      Sometimes one got to make decisions that the majority of people might dislike. (Though, the democratic system is kinda flawed in this regard…Democracy drives popularity, not functionality.)

        1. “Don’t act like the FCC is driven by wisdom”
          eh?

          I literally stated that the FCC should be acting responsibly and ensure proper usage of what they govern.
          I didn’t state that they currently do that, just that they should.

          Just like one can reasonably say that people should be acting with good intentions, but that doesn’t mean that people do.

          My comment were simple criticism.

    2. I mean welcome to the US, we’re corrupt as hell. The FCC will do whatever Verizon et. al. pays them to do, full stop. FULL STOP. They don’t give a damn about you or me. It’s just another corporate entity in state costume, like the rest of our federal government.

      Also: a reminder that 5G is for surveillance and automation, not consumers. They parade around stories about how you’ll be able to download a feature film in four seconds or whatever. That’s not the point of the technology; obviously nobody needs a film to finish buffering that fast. 5G is for massive bandwidth required by automation to take jobs away and surveillance to make sure the new poor can’t revolt. That’s it. I don’t believe any of those weird cancer conspiracy theories about it, that’s hogwash. But it’s a huge power grab and a massive privatization of crucial infrastructure that can and will be used to hurt you. And they’re being EXTREMELY pushy with it in legislation. That’s how you know it’s a huge turd. They always do that with stuff that’s shady. There’s no race; it’s just bad tech and they know people will eventually figure out that it’s a nightmare and offers them very little.

      1. I keep seeing ads for the future use of 5G and see things like it will be used to interconnect medical products and provide comms for remotely controlled robotic surgeries. Under what circumstances would anybody who is not completely insane connect life critical processes into a “best effort” non QoS network that the backhaul goes God knows where and is locally shared by 10s of thousands of Netflix and Facebook users. all of these services say “up to “: dataspeeds. No minimum CIR or any prioritization of any sort.
        I think the carriers and FCC are BSing us a lot on 5G, particularly considering the very limited high speed coverage distances.
        Sure the download speeds are very fast, but is there an offering that isn’t based on a metered plan? Gives you the opportunity to blow through your plan in a day instead of a month.

        1. It’s particularly ridiculous when you realise that you could blow cell service 4GB and 10GB caps with a 56k modem, which is capable of ~18GB if ran all month.

    3. GPS matters, because it’s already marginal, but 1200MHz is a lot to reserve just for offshore oil platforms. It is very hard to imagine needing multiple gigabits to maintain safety, and if they do, they might want to reconsider why the are trusting lives to something that can be jammed by someone playing VR games.

      Rural internet links are often done with very very high gains, and pointed across areas with almost nobody in the path. Won’t the effects be fairly minimal?

      Especially when they don’t seem to be allowing this stuff outdoors without AFC?

      This has the potential to make public mesh networking practical. To make cell service more reliable. To eliminate WiFi crowding at trade shows.

      The FCC does a lot of stuff I don’t like, especially their FHSS laws that encourage making more interference than needed, but this particular thing seems reasonable.

      1. C band. Of course the 1.2 GHz comes from a varieties of sources not just satellites. Satellites use 36 or 72 MHz transponders and most links are a small subsection of that . The spectrum they’re taking does negatively impact the fleet of C band satellites and requires them to be significantly idling and shut down.
        Terrestrial microwave. There is a subtle point here that might not be obvious. The 6GHz is currently a licensed and frequency coordinated service which has high reliability long haul performance. We are becoming used to un coordinated unlicensed wild west radios where you can use 5 GHz for longer distance point to point links but if someone fires up another link within your F:50/10 interference zone, there are likely a few days per month where your throughput could go from 600 Mbps to 128 Kbps (and you cant track it down) Or someone in your point to point path putting up a wifi router and wiping out the link altogether. This stuff doesn’t happen in 6 GHz (yet).
        The current 6GHz system is carrier grade and they go to great pains to provide internet, phones, cellular backhaul, etc. These radios are typically in the range of $80,000 + each end and part of serious network operation. Even AT&T has filled formal complaints about this.
        Surprisingly there are hundreds of networks at various frequencies running over RF links that provide background stuff that nobody is really even aware of but when politicians start breaking things just to support cronies, a lot of unintentional results will occur.
        Like a rural town loses internet.

    4. Yeah, and it’s not just offshore oil rigs either, Ladies and Gentlemen.

      This spectrum is also used as a licensed SCADA backhaul for utilities such as Electric, Water, Gas, and in many cases, including tenants at various utility sites, such as police and fire.

      The reason they like the 6 GHz spectrum is because it’s reliable. You can go to 11 GHz, get more bandwidth, and they’ll be so so thrilled –until the first really hard rain hits. Path fade is no joke.

      Yes, the DC region has county police and fire radio traffic on this. It has water and waste-water traffic. It has Electric Utility traffic. Gas utilities use it.

      Do you like civilization or are you really that lazy about wiring that you’d rather see critical infrastructure traffic get unreliable?

      The Utilities Telecommunications Council has already begun looking at options for relief. This is your FCC at work, placating the masses while jeopardizing the very people who make their lives possible.

      And to those who seek to blame one administration or another, I’ve been watching the FCC filings off and on since the late 1970s. It was a dumpster fire then, and it hasn’t gotten any better. Engineering concerns have been relegated to the broom closet –and now the FCC has given up all pretense of knowing anything about engineering and they’ve eliminated the Engineering office altogether.

      But don’t listen to me. Enjoy your bandwidth. Until the lights go out. And the water stops flowing. Have fun.

      1. I used to wander the halls on M Street and I was always amazed that the guys making all the decisions in suits and ties had such little understanding of the issues and that the real answers were almost always provided by guys in jeans and sneaks.
        SCADA is just the tip of the iceberg. A single SCADA network would not be unusual if it had 8000 remotes. And there are thousands of networks doing everything from measuring pumpjacks to river flow to whether the stock tank is full on the lower 40. Imagine a trans America pipeline in the future (after having to touch each remote to change frequency) at the network operation center and saying ” can’t really tell if there is a (leak/explosion/ etc. fill in the blank) because it is raining in Nebraska today.”
        it’s almost impossible to visualize how many behind the scenes huge networks are running in America and how many mundane and transparent services are provided. You never really see this until all Dallas parks have dead grass because the telemetry had interference, etc.
        Giving politicians spectrum allocation authority is like giving a chimpanzee a machine gun.

  7. I was expecting some information in the article like the following:
    current allocation: 5.725-5.875 GHz (center frequency 5.8 GHz; bandwidth 150 MHz)
    ref: wikipedia “ISM_band”
    future allocation: 5.925–7.125 GHz (center frequency 6.525 GHz; bandwidth 1200 MHz)
    ref: https://docs.fcc.gov/public/attachments/DOC-363945A1.pdf

    And that raised the question in my mind as to why is 5.875 to 5.925 GHz was not included. Then I looked up the amateur radio frequency allocations and they have a SHF 5 cm band allocation from 5.650 to 5.925 GHz and that explains the reason for the gap.

  8. I think it is a shame that WiFi is being attributed to the “microwave oven”… The microwave oven was just a single frequency ‘happy accident” that never went any further than warming up your food. There was a reason why the original Amana product was called a “radar range”.

    The tech for frequency hopping and precision variability for communications was invented by Hedy Lamarr… How about acknowledging Hedy Lamarr for her invention and the technology that led to your WiFi, Cell Phone, Bluetooth, and GPS?

    We really owe this all to her invention… not the microwave oven.

    1. That’s Headley, Headly Lamar (blazing saddles)..
      The contribution of the anti jamming mechanical frequency hopping Hedy Lamarr invented although very innovative for it’s time has been way overstated as the basis for a lot of modern stuff. Honestly without modern forward error correction, frequency hopping is no more or less efficient than multiple discrete frequencies. It is much harder to jam unless you know the hop frequencies, but if you have 2 transmitters occupying the same frequency at the same time you will have interference. If you had 10 frequencies and 11 hopping radios you will have 1 radio constantly interfering randomly with all radios. The real basis for cellular, WiFi and most comms of today is digital modulation coding, forward error correction, combined IQ modulation constellations and spread spectrum which has a whole lot more to do with Shannon than Lamarr.

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