Will 5G Undermine Weather Prediction?

Reposted from Cliff Mass Weather and Climate Blog   HT/RonPE

Saturday, May 18, 2019

There have been a number of media stories this week about a major threat to weather prediction:  the sale of electromagnetic spectrum for new 5G cellphone service.   The problem is that some of the wavelengths being auctioned off for 5G are critical for an important class of weather satellites, with 5G signals potentially undermining our ability to forecast the weather.

Currently, 4G cellphone technologies provide roughly 100 megabits per second (100 million bits per second) of communication speed, while the proposed 5G service could achieve 10 gigabits per second (10 billion bits per second).  Downloading movies and animations would be much quicker, with hardwired connections becoming less critical for most uses.
But to achieve such service one needs a larger communications highway, which means the use of more of the electromagnetic spectrum.   Electromagnetic energy, such as radio, microwaves, and visible light, are characterized by ranges of wavelength and frequency.  The use of these wavelengths is controlled by our government, which can auction off specific frequency/wavelength bands.

787px-EM_spectrum.svg

Among the spectrum recently auctioned off by the FCC for 5G is a band of frequencies near 24 GHz (GHz is gigahertz, or a billion cycles per second).   Unfortunately, this is close to 23.8 GHz, a frequency in which water vapor emits microwave radiation and which is used by weather satellites to determine the three-dimension properties of the atmosphere.  And that information is very important for providing the description of the atmosphere that is required for numerical weather prediction.

Why weather satellite information is important for numerical weather prediction
Numerical weather prediction, the foundation of all weather forecasts, depends on securing a comprehensive, three dimensional description of that atmosphere–known as the initialization.  The better this initialization, the better the forecast.
One of the key reasons why modern numerical weather prediction has gotten so good is that weather satellites now provide 3D data over the entire planet.  Even over remote oceans and the polar regions.  Roughly 95% of the total volume of weather information now comes from weather satellites.

Before weather satellites, radiosondes were the main source of

weather information above the surface

And the most important source of weather information is from a collection of satellites that contain microwave sounders.  These satellites observe the earth by sensing microwave radiation being emitted by water vapor, liquid water, ice, and the surface.
The amount of radiation being emitted can be related to temperature.  And different wavelengths/frequencies reveal the conditions at different levels of the atmosphere.   To put it another way, by sensing emissions at various wavelengths, one can secure a profile of temperatures at various levels in the atmosphere.  Kind of like have radiosondes (balloon-launched weather observations) everywhere.  Very valuable information

The Microwave Sounder Unit on the AMSU-A satellite

What is the most valuable of all satellite observations?
Satellites with microwave sounders like AMSU-A (see below).  That platform ALONE contributed to a 17% reduction in forecast error in the European Center global model (the world’s best)

AMSU A looks at the atmosphere in 15 wavelength/frequency bands or channels,  including sensing the atmosphere at wavelengths that the atmospheric water vapor has peaks in emission (see below).

Channel 1 is at 23.8 GHz.   The problem is that the FCC has sold off 24 GHz, which is very close to 23.6 GHz.   And if the 5G transmitters aren’t very high quality, with little spread to neighboring frequencies, they could well interfere with the microwave weather satellites.
Why?  Because the weather satellite have very, very sensitive receivers because they are trying to sense the weak microwave emissions of atmospheric water vapor.  These sensors could be overwhelmed by the active TRANSMISSION in nearby wavelengths by thousands of 5G cell tower transmissions or other sources.
And the problem is even worse than that.  The FCC is planning to auction off more wavelengths/frequencies, some of which are close to other wavelength/frequency bands used by the weather satellites.

The potential harm to U.S. and worldwide numerical weather prediction by interfering with the 23.8 GHz band is certainly real, but difficult to quantify exactly.
First, it will depend on the characteristic of the 5G transmitters and to what degree they will contaminate the nearby weather observation bands.
Second, it depends on how many wavelength bands would be affected.
Third, cell phone coverage does not include the entire planet.  One analysis suggests that only 34% of the earth’s surface has cell phone coverage, suggesting that roughly 90% of the planet would be clean of interference (71% of the earth’s surface is covered by water).  But if plans to establish satellite-based 5G on commercial ships and aviation come to fruition, the problem would be much worse.

NOAA, NASA, and U.S. Navy are quite concerned about this issue, with the Navy writing a strong statement of the potential harm.  On Thursday, NOAA Administrator Neil Jacobs warned of a potential loss of  1/3rd of current forecast skill.  These warnings need to be taken seriously.

The key now is to have close coordination between the FCC and NOAA/NASA/DOD, as well as other international players, to ensure that spectra close to the weather observing frequencies are not used and, if there are, investments in high-quality transmitters, with effective filters, are required by law.

Improved forecast skill derived from weather satellites has had huge positive impact on saving lives and property, and in fostering economic growth.  Reasonable actions must be taken to protect the value of weather observations from space.

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61 thoughts on “Will 5G Undermine Weather Prediction?

  1. Get ready for Urban Cell Index (UCI) and the associated temperature adjustments being cranked up even more on the 10% of the planet that will be covered by 5G. Just in time to save corrupt climate science from the dreaded Pause.

    • I flagged this story in hits ‘n’ tips about a week ago. Good to see some more info.

      Emission peak also means absorption peak. I don’t think infrastructure firms will be wanting to throw transmission energy down the hole. Also we should remember that 90% of our bodies and brains are water. If you can’t feel the tingle for a 4G , you sure will feel these babies.

      Just a little bleed-over into the AMSU bands would be a very convenient way to create some of that “missing heat”. What the alarmists need right now is a break to the on-going continuous record. They need something new to “correct” for.

  2. CTM ?

    “Kind of like have (having?) radiosondes (balloon-launched weather observations) everywhere.”

    • Charles the Moderator – not Charles the Editor. You might say “above his pay grade.”

      In any case, this was a re-post from elsewhere. All that an editor could do would be to insert a [sic].

  3. Maybe, if the planet is not warming to specification, it will be very convenient to have the satellites failing…

    With 5G, a particular concern for the transmission companies is that this is the proposed protocol for the ‘Internet of Things’ (IoT). This is the proposal that large numbers of household objects will be ‘smart’, and will connect to household controlling networks. Thus, all of your light-bulbs might be on your network, as we ll as your fridge, washing machine, etc, and they would be controlled for optimum efficiency.

    The problem for the transmission companies is that the bandwidth requirements are horrendous. We may not be able to cope, even with Chinese companies providing cheap kit. Without them…

  4. Also will cause spurious warming/moistening signals for climate monitoring. We fought this issue with AMSR-E data at 6 GHZ and 10 GHz, and now the problem will only get worse.

      • I checked my weekend weather last Friday and from a whole bunch of sites got a variation of forecasts, many showing showers for both days. And there wasn’t a drop of rain all weekend. So much for the increased accuracy.

        • A test of increased accuracy means comparing forecast quality from years ago to recent times. You compared recent forecasts with recent forecasts, that only tells you that in showery conditions, your forecasting isn’t very good.

  5. I have to call BS on this “And if the 5G transmitters aren’t very high quality, with little spread to neighboring frequencies, they could well interfere with the microwave weather satellites.”
    Everything that transmits RF has to go through the FCC testing labs, da. There is 200 Mhz from 23.8 to 24 Ghz, a simple notch filter can drop anything 10Mhz above 23.8 to below the noise level. The magic words strikes again “IF and COULD”, if and could appear to be able to do anything.

    • Kevin & Mat,

      Bandwidth-to-transmit frequency is proportional. The separation is 8.33 X 10(-3). This is still a very steep filter slope.

      The issue is that this frequency band had been virgin to monitor complex moisture. Now there will be a noisy neighbor in isolated concentrations.

      Personally, I think that 5G will be the HD Radio of the decade. Famous last words.

      • My favorite noise source is a transmitter plus a chain link fence. The electrical contact between the strands of wire is often just bad enough to be non-linear. If the transmitter signal hits anything with a slightly bad connection, noise results.

        I’m slightly surprised the satellites aren’t already suffering from interference from the kind of accidental transmitters described above.

        With regard to atmospheric attenuation … that’s actually a good thing. Cell towers are engineered so they have limited range. That’s a requirement of the system.

    • First of all, unless you are going to volunteer to strap your ass to a rocket on a 1-way trip and go change-out the satellite AMSU receivers on a SV in a 705 km polar orbit, then the hardware on existing SV’s isn’t going to change from when it went up.

      That being said, what about a notch filter on the terrestrial 5G transmitter to suppress unwanted RF energy intothe AMSU receiver:
      The 5G freq band in question is UK/EU proposed 24.25 GHz -27.50 GHz.
      The North American band is 27.5 GHz – 28.35 GHz, so not really the issue as I see it.

      In the US, the FCC has already licensed the 24.0 -24.25 GHz band to radar devices for lwa-enforcement speed devices, and traffic flow monitoring devices such as the device from WaveTronix:
      http://www.advancedtraffic.com/products/wavetronix/smartsensor-hd/smartsensor_hd_datasheet-20120427102359.en.pdf
      The thing about these speed/traffic monitoring devices is they are not ubiquitous, they isolated systems in urban areas like in So Cal, Denver area, on the freeways. And the K band cop radars are rapidly being phased out of most LE agencies for the newer, much better Ka (~34 GHz) band radars.

      So the issue as I see it is the EU/UK 5G spectrum allocation, where these 24.25 GHz transmitters will be everywhere on towers and on the ubiquitous handsets. Now the handsets will be much lower power, probably 20 dBm max (100 mW), while the towers could easily be pushing out 1000 to 10000 dBm (1- 10 watts).
      Lets focus on the handsets, since these devices are lower power, but can’t incorporate (due to cost) a high performance band-pass filter on the handset transmitter module.

      A “good” notch filter might provide 60-70 dB attenuation 0.25 GHz off center.
      A 100mW transmitter is +20 dBm, with an internal antenna maybe another 3 dB gain, call it +23 dBm ERP.

      +23 + (-70) = -47 dBm interference signal at 24.0 GHz

      The AIRS AMSU-A2 Channel 1
      Noise at 23.8 GHz with up to 400 MHz bandpass (+/- 200MHz) roughly with a typical -75 dBm noise floor power.
      see: https://airs.jpl.nasa.gov/mission_and_instrument/instrument/specs

      Assume the AMSU-A2 receiver gets a minimum 20 dB SNR, or about -55 dBm for the water vapor signal.

      The Problem: the signal to interference ratio is then -55 – (-47) = -8 S/I ratio. No good.

      Therein lies the problem. The EU/UK 5G allocation at 24.25 GHz needs to be bumped up in RF by at least 200 MHz, becasue no one can change out the SV hardware already in orbit, to prevent loss of this Channel 1 on the AMSU-A2 AIRS satellite when it is over Europe a making sounding readings.

      The other option is to limit the handset transmitter power to 10 mW in that band (24.25 GHz), and on the tower installations use a high performance (higher cost) notch filter to attenuate RF at/below 24.0 GHz by at least 80 dB.

      • erratta:
        “…1000 to 10000 dBm (1- 10 watts)” , ooopss I meant “30 dBm to 40 dBm”. My bad.

      • OH, thank God! Someone who actually knows what they’re talking about. 😉

        The 5G freq band in question is UK/EU proposed 24.25 GHz -27.50 GHz.

        The EU/UK 5G allocation at 24.25 GHz needs to be bumped up in RF by at least 200 MHz

        So, that sounds like just limiting themselves to 24.50 GHz – 27.50 GHz would completely solve the problem. Or do the really need that 0.25 GHz? Could they bump the 27.50 to 27.75, or would that interfere with something else?

        ~¿~

      • “First of all, unless you are going to volunteer to strap your ass to a rocket on a 1-way trip and go change-out the satellite AMSU receivers on a SV in a 705 km polar orbit”

        I’ll go.

        • 1-800-ASK-ELON

          He’d be the type crazy enough to send someone for the publicity.

      • Joel O’Bryan

        Thanks, very informative.
        Here you know a lot of “teachworthy” matter…

    • The channels 24 GHz 5G allocations are 40 MHz wide with the lowest band is at 24.250-24.290. From what I could find channel 1 on the Advanced Microwave Sounding Unit is 23.8 GHz with a bandwidth of 251 MHz and a center frequency stability of 10MHz. Worse case there is more than 300 MHz separation between the two channels. Another thing to be aware of is the 5G transmitters are are directional. Very little of the energy will be emitted upwards. The handset channels which would be omni-directional start at 25.050-25.090 GHz.

      • Limiting the handset transmitter power in that problem band would be the first thing to look at as a solution.
        The problem with the 40 MHz wide channels is that is 3 dB (half power) channel definition, for spacing between like channels. The actual radiated power at 25.0 GHz (250 MHz lower) is like a probably 60-70 db roll-off. If the receiver’s SNR is 20 dB, and the noise floor around -70 dBm, then a terrestrial 5G signal with 20 dBm EIRP signal (100 mWatt) at 24.25 GHz will still put -50 dBm radiated power at 24.0 GHz, which is at the top of the band cut-off for the Channel 1 receiver. This could easily swamp the water vapor signal in the receiver, where a SNR of 20 dB is needed to measure the water vapor signal at 23.8 GHz (+/- 200 MHz).

        I can’t find anything that gives the US FCC allocation for 5G in the 24.25 GHz range. That is the EU/UK allocation that to me seems to be the immediate problem. So not sure what the FCC role in this is.

        • The problem with the 40 MHz wide channels is that is 3 dB (half power) channel definition, for spacing between like channels.

          No it isn’t. In fact there is no need for spacing between channels due to the nature of OFDM encoding. A plot of the frequency spectrum of the rather old 802.11a wireless standard (20 year old technology) using OFDM show that outside the 20 MHz band it is into the noise floor. The FCC designate channels for the cell towers are:
          24.250-24.290
          24.290-24.330
          24.330-24.370
          24.370-24.410
          24.410-24.450

          The handsets channels are:
          25.050-25.090
          25.090-25.130
          25.130-25.170
          25.170-25.210
          25.210-25.250
          There is no spacing between channels because they simply don’t need it.

          • I hadn’t found that the FCC was licensing 24 GHz bands. I see that now at:
            https://www.fcc.gov/auction/102/factsheet

            But that changes nothing about what I wrote. (Using a 2.4 Ghz 802.11a spectrum is not relevant.)
            The speeds bandwidths are not similar, even so one can see the best attenuation in that plot is -50 dB out to 40 MHz.
            When a 5G tower transmitting at 24.25 GHz is pushing 10 watts (40 dBm) with 6 dB antenna gain, +46 dBm power even 70 dBm attenuated is going to be placing -24 dBm power into the AMSU channel 1 band pass, swamping the water vapor signal. Even at 1 watt (30 dBm) this is still swamping a -55 dBm water vaor signal in the rx bandpass.

            In Wikipedia I find this statement: “In the U.S., Verizon is using 28 GHz and AT&T is using 39 GHz.”
            I’m am not clear who in the US is buying 24 GHz spectrum for 5G.

            To my analysis, the FCC should immediately withdraw Blocks A and B of Auction 102, and/or rescind/refund any bids so far accepted/paid.

          • Joel O’Bryan May 21, 2019 at 10:35 pm

            When a 5G tower transmitting at 24.25 GHz is pushing 10 watts (40 dBm) with 6 dB antenna gain, +46 dBm power even 70 dBm attenuated is going to be placing -24 dBm power into the AMSU channel 1 band pass, swamping the water vapor signal. Even at 1 watt (30 dBm) this is still swamping a -55 dBm water vaor signal in the rx bandpass.

            re: “+46 dBm power even 70 dBm attenuated is going to be placing -24 dBm power into the AMSU channel 1 band pass, ”

            How do you figure that?

            At an average height of 700 km the “path loss” is -172.6 dB at 24 GHz.

            Now add in antenna gains and put in a power level to work with to arrive at the power level into the AMSU sensor.

      • Greg F

        I think the whole challenge of 5G management was reflections and multiple signals being received, parsed, ignored and sending requests for retransmission – it just happens so fast that “it is worth it”.

        While directionality (at least as a flat pattern, not wasting energy skyward) is helpful, reflections off vehicles and buildings is the nightmare that 5G supposedly overcomes.

        Suppose you wanted to hide a transmission to a second recipient in a replication of everything legitimately sent to the intended address. With so much repetition and packet copying going on, it is impossible (or nearly impossible) to notice the duplication. Instead of spying on / tapping a channel, 5G supports sending an additional copy of all packets to a second (“legitimate”) address. The bandwidth is so high and the confusion of multiple towers and signals being what it is, tapping the data stream is a dream.

        The probable solution is highly directional receivers on the satellites, and notch filters as described above. With horizon-sighting satellites reading the temperature at various altitudes, the absence of skyward transmissions will not help, because horizontal on the ground is looking directly into the satellite located on the distant horizon. Oops.

  6. From the article: “… weak microwave emissions of atmospheric water vapor …”

    Weak? If they’re weak then how do they keep the Earth 33C warmer than expected?

  7. You know that’s a 200 Mhz separation.. Right? Which is more than the entire am/fm radio range, or about 20 UHF TV channels…

    • I remember when FM radio switched from analog to digital. Before a strong station at, say 104Mhz, could swamp any other station within a Mhz or two.
      After, that same station was listed as 103.9Mhz, and the digital radio automatically jumped between frequency points that were only 0.2Mhz apart. And you rarely had trouble picking up stations that were that close together.

      I’d love to here from someone with actual experience working with these frequencies, about how likely it would ever be to have bleed across 200Mhz at this wavelength. They said 5G is going to be ‘around’ 24Ghz. How wide a patch are we talking here. Will it be 23.8 to 24.2, or more like 23.995 to 24.005.

      ~¿~

      • You need to understand some fundamental narrow band (NB) versus wideband communications (WB) issues.
        These high 5G data rates mean WB comms to accomodate the power spectrum waveforms and a SNR of at least 33db to maintain an adequate link budget for reliability.
        On a 25 KHz wide NB FM channel you can slap 1200 or 2400 baud modem with FSK and go to town sending text messages. If your SNR is strong enough you might even get away with 9600 baud. Welcome to 1980.

        With 2020 era 5G, We’re talking pushing 4K HD movies (with lossfree compression and forward error correction on QPSK modulation) to many small handsets at the same time. That takes big bandwidth and big SNR.
        Nothing in NB comms even come close to compare to 5G.

        • Thanks Joel, you and a few others here have provided a lot of info to help with understanding this problem for those of us without the knowledge.

          I know I at least didn’t even know what I didn’t know. 😉 it’s hard to look up stuff when you don’t even know the terminology.

          ~¿~

        • Glad someone mentioned modulation. Would’nt it be easy to distinguish synthetic microwave from atmospheric mm by checking for any kind of modulation? Could that be done with software on the Sat data, i.e. no hw upgrade needed (or flash).?

  8. Another big problem for 5G is that its frequencies are so high that the signal cannot penetrate walls, windows, or foliage. You would probably have to step down to 4G frequencies whenever you are indoors, except maybe for those living very close to transmitters, or those willing to install an outdoor antenna for use as a signal repeater on Wifi or something similar.

    https://www.iotforall.com/5g-issues-penetrating-windows/

    • WiFi (2.4 GHz) integration is to be a big part of 5G operation for the consumer.

      • So you’ll have to put a receiver outside your home to get the high frequency 5g signal from the provider? And this is progress?

        • No, it means you walk into the Big Indoor Mall with it’s concrete-steel walls that shield 5G, but then your phone seamlessly connects to the Mall WiFi signal to keep watching your movie or video chat.
          If you choose to use your home WiFi on your mobile 5G device, then your home WiFi will need Gigabit broadband and router upgrades to stay up with 5G speeds.

          No different than the death of dial-up ISP 20 years ago.

          • I do not know why you are even discussing wireless technology, we have been future-proofed with the fibre NBN. Every troll knew that years ago.

    • Ericsson has a great demonstration of the ability to penetrate a door with 5.2GHz at a recent show.

  9. I’ve been assured that the weather is only going to get hotter for the next 100 years, why do they need to forecast weather at all? It’s already done. And after 12 years, as I understand it, they don’t believe our civilization will be alive.

    /sarc

    It would seem that 5G data transmission would allow more people to find WUWT, and get a real understanding of how poor the science is in Climatology. That must not be allowed to happen.

  10. Come on. What is more important—a tornado warning or your Facebook page and newfeed? (Hint: Last Man Standing addressed this!)

  11. My problem with 5G is the phone companies still have not perfected 1G. Why are they investing in the 5th generation when every one of them has dead zones in well populated areas? If I cannot use the phone part of my smartphone, nothing else matters. 5G is just a gimmick. I want more than anything else the ability to send and receive calls without drops indoor and outdoors in every area where people live. Except in radio blackout zones because of radio telescopes and the like.

  12. I believe the concern would be with Europe’s and China’s allocation of 24.25 – 27.5 GHz. The US seems to have only allocated 27.5 – 28.35 GHz although there is a bit of ambiguity in the references I could find about 24.25 – 24.45 GHz. This would put it 450 MHz above 23.8 GHz.

    Also with any RF transmission system (wireless or wired) the engineers allocate a guard band of at least 5% on either end of the spectrum to minimize/eliminate leakage (these are engineers not scientists after all). So in the European scenario the system would be designed to operate above 24.4125 GHz giving over 600 MHz of space.

    • This separation of bandwidth zones to different countries means that, when China goes to war, it can immediately jam EXACTLY the specific bandwidths that its specific enemy is limited to using. And “permit” aliied or seemingly neutral countries to be “permitted” to remain outside the jamming bands. As long as they remain “properly” neutral towards China, of course.

      And all the while enjoying absolutely no limits on its own bandwidth and its own hardware and antennas and software!

      • Aaaand it means their enemies can do the same thing back to them, assuming they have the technology. Which is why many modern militaries have equipment that can work across much larger bandwidths then civilian. Or why many have developed auto tracking laser communications equipment.

        Wars aren’t automatically won by those with the newest toys, but it helps.

        ~¿~

        • bonbon May 22, 2019 at 5:00 am
          War means EMP, kiss all comms goodbye.

          Do you believe in global warming?

          EMP effects are pretty much based on no more than modelling, like global warming.

          So, why would you simply believe in EMP?

  13. “which means the use of more of the electromagnetic spectrum. Electromagnetic energy, such as radio, microwaves, and visible light, are characterized by ranges of wavelength and frequency.”
    ——————–
    And the above explains it better…
    These guys either really illiterate or deliberate “devious” with their argument.

    Yes the electromagnetic spectrum and more and more increase of it means a characterization range
    in the context and addressing of electromagnetic energy consideration, but by no means it suggests or dictates that it must be in the same ratio as the previous platform utilized.

    The way of a new 5G platform does not by default means that an over increase in electromagnetic spectrum will result, or it has to result in an increase of electromagnetic energy in some same ratio.

    If that the case, of some same ratio to consider, then 5G will not even be possible to consider in paper, let alone in reality.
    All point there is a consideration in ‘the characterized range”, that actually does not mean any hipper increase of energy in relation to frequency spectrum increase.

    Without such increase in electromagnetic energy, as claimed by “characterizing” clause, there does not have to be any problems considered as per the claim portrayed in this blog post…

    Energy, is the main point, not the spectrum.
    If a huge increase in spectrum without much so increase in energy will not change anything, or will change nothing, as far as weather or detection weather systems concerned, in this regard.

    A characterized range is not a proper quantity range to be considered, far from it, in any given situations,
    only to be used or abused as means to force a false or fake claim, usually…

    Again, as far as I can tell, 5G can not be possible if a high increase of electromagnetic spectrum will result in an increase of electromagnetic energy in any consideration to worry about, especially when it comes to matters of weather, or such associations.

    Oh, well, maybe again me missing the point…

    cheers

  14. If Michael mann and Hansen in their older years would admit they were wrong about AGW. They would go down as heros. I predict they will.

    • Not a chance. Like Paul Ehrlich they will go to their graves clinging to their failed predictions. No reality will ever be allowed to falsify their beliefs.

      ~¿~

  15. 5G will undermine our ability to predict the weather? Gosh, I guess we are safe then

  16. If there is a risk that moving to 5 G may cause a problem to other vital services, why do it. I would think that the service with 4 G is more than sufficient.

    As a radio amateur, call sign VK5ELL, I do have some knowledge of the possible problems.

    MJE VK5ELL

    • Michael.

      I do totally, do agree with you…in this one…
      The punch card computers were more sufficient and efficient that 3G smartphone networks,
      and the evolution (technological) may cause and be a problem to other vital services of whatever…ever…
      A very real concern there, accepted, but…
      “frack up” and discard evolution and go for embracing in an enlarge the utopia…
      the proper way forward for and within the means of proper progress within the realm of stupidity at large,,, discarding evolution,,, happens to be too bad, I will say…at least in context.

      But hey, that is me…

      cheers

  17. My background is Mobile Technology with Telstra and Ericsson. The disclaimer is that I haven’t been involved with Mobile systems since 2010.

    This paper is a good start

    https://www.gsma.com/spectrum/wp-content/uploads/2018/11/5G-Spectrum-Positions.pdf

    From 24GHz up the bandwidths can be from 55MHz to 400MHz. If the carrier freq is 24GHz and the bandwidth is 400Mhz then there may be interference with the weather satellites so the answer to that is keep the bandwidth to 55MHz. Some points to consider. These mm Frequencies will only be used in high density population centres and the power output will be low therefore their range will be small. The antennas will be slanted downward so upward leakage will be minimal. Bandwidth filters are very high quality in Mobile Technology. Keeping this in mind what is the minimum altitude for weather satellites? Do they measure to ground level? If minimum altitude is say 400 meters above ground level then there shouldn’t be any interference.

    The 24GHz frequency should be ok as long as the bandwidth is no more than 200MHz.

    • Steve,
      The article claims that 5G will have bandwidths up to 10 GHz
      which suggests that the band will have to be several gigahertz wide at
      least. I am skeptical that is going to be a reality but if it were then clearly
      the microwave peak would be overwhelmed by the 5G signal.

      • “It support channel sizes ranging from 5 MHz to 100 MHz for bands below 6 GHz, and channel sizes from 50 MHz to 400 MHz in bands above 24 GHz. The full capabilities of 5G will be best realised through the wider channel sizes in new 5G bands. The ITU’s minimum technical requirements to meet the IMT-2020 criteria – and thus the fastest speeds – specify at least 100 MHz channels per operator.1 They also specify support for up to 1 GHz per operator in bands above 6 GHz”

        They are specifying 100MHz channels (bandwidth). They support an operator having 1 GHz therefore 10 channels. Makes sense.

        You have made me read that document 3 times and there is zero mention of 10GHz Bandwidth.

    • re: ” Keeping this in mind what is the minimum altitude for weather satellites? ”

      For the AMSU mentioned in the OP article, it is indicated they are used on polar orbiting sats in the 600 – 800 km altitude range.

      For 700 km average height, I calculate a “path loss” of 172 dB at 24 GHz. Then budget for power and antenna gain/loss.

  18. “In an appeal to the European Union, more than 180 scientists and doctors from 36 countries warn about the danger of 5G, which will lead to a massive increase in involuntary exposure to electromagnetic radiation. The scientists urge the EU to follow Resolution 1815 of the Council of Europe, asking for an independent task force to reassess the health effects.”
    https://www.jrseco.com/european-union-5g-appeal-scientists-warn-of-potential-serious-health-effects-of-5g/

  19. This whole discussion has been about the 5G signals messing with the satellite receivers and leading to false readings. Well, how about looking at what does all that transmitted energy do to the water vapor in the area since it’s close to the natural frequency of the molecule? Would “excited water vapor’ lead to the sats seeing things as wetter than they really are?

  20. Until somebody cites the technical spec for the transmit waveform “mask” (emission mask, or “Bart Simpson head” as seen on a spectrum analyzer) most of this talk is just subjective, mixed with a smidgen of objective …

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