5 ms·

How did 5G get this far into deployment all around the world without the apparent issue of interference being addressed much earlier?

formerly_proven 5y ago
Probably because there isn't any problem. Though it could also be that 5G in the US is meant to use some different channels / frequencies than elsewhere, as was done in older wireless standards.
- p_l 5y ago
  Most countries simply don't allow the frequencies FCC wants to approve.
  - gormandizer 5y ago
    Nearly 40 countries have already adopted rules and deployed hundreds of thousands of 5G base stations in the C-Band at similar frequencies and similar power levels—and in some instances, at closer proximity to aviation operations—than 5G will be in the U.S. None of these countries has reported any harmful interference with aviation equipment from these commercial deployments, as the Federal Aviation Administration recently confirmed.[0] [0] https://ecfsapi.fcc.gov/file/1103192305940/211103%20CTIA%20Ex%20Parte%20on%20C-Band%20International%20Deployments.pdf https://ecfsapi.fcc.gov/file/1103192305940/211103%20CTIA%20E...
    - p_l 5y ago
      The very nice weasel wording used tries to make it sound like 40 countries approved above 3.8GHz, but the further paragraphs explain that only japan did so, without going into much detail other than the low guard band. The FAA complaint is about 3.8-3.98GHz, and all other examples involve no frequency allocations above 3.8GHz
      - gormandizer 5y ago
        Absolutely zero weasel wording. The initial deployment of C-Band in the US is 100 MHz of spectrum from 3.7 to 3.8 GHz. The remainder of the auctioned C-Band from 3.8 to 3.98 cannot be deployed until the incumbent satellite operators clear the band on or before December 2023. For 2 years there will be a 400MHz guard band.
deleted 5y ago
[deleted]
can16358p 5y ago
Because there is no evidence of any interference. Boeing and Airbus are requesting something without showing any evidence, which could have been easily detected in a test environment.
- onphonenow 5y ago
  Their views aren't even that logical. You already need multiple radar altimeters on ONE plane much closer physically and spectrum wise than 5G. In busy airports you already have multiple altimeters operating again closely physically. Anyways, even if there is interference, it's actually boeing that should fix their systems to operate within their assigned band (ie, operate in the middle of the band, and reject signals outside of band). This is radio 101 stuff.
  - p_l 5y ago
    Only one radar altimeter is generally operational at a time (transmitting), due to high bandwidth involved, and latest ICAO working group reports are "we don't know yet if it's safe with current equipment, retrofitting will take years as they can't even start designing new models till interference data is available, and that countries are implementing temporary mitigations in 5G base stations"
    - onphonenow 5y ago
      That's where we find how technically incompetent ICAO is I suppose? Something that has been a decade in the making, they haven't been able to conduct basic tests on. I'm a lay person, but can easily think of basic tests that would help resolve this question. "On a large aircraft two or three altimeter systems are employed and these systems could utilize a frequency offset of 5 MHz to 10 MHz." Something is rotten with the regulators.
      - p_l 5y ago
        Radio altimeters have bandwidth as high as 170MHz, and a lot of work goes into ensuring other devices in 4.2-4.4 band do not interfere with them. The fact that certain radio systems can utilize low bandwidth does not mean every system is like them.
stefan_ 5y ago
The sibling comments here are also correct of course but keep in mind that 5G, excluding stuff like mmWave, does not prescribe any particular frequency band to use and can work on just about any. Regulators will find some slice of free frequency space somewhere between roughly 1 GHz to 5 GHz and auction it off and then carriers and device manufacturers will make 5G run in that band. The iPhone 13 for example can use literally 30 different 5G bands on the US models.

formerly_proven 5y ago

Probably because there isn't any problem. Though it could also be that 5G in the US is meant to use some different channels / frequencies than elsewhere, as was done in older wireless standards.

p_l 5y ago
Most countries simply don't allow the frequencies FCC wants to approve.
- gormandizer 5y ago
  Nearly 40 countries have already adopted rules and deployed hundreds of thousands of 5G base stations in the C-Band at similar frequencies and similar power levels—and in some instances, at closer proximity to aviation operations—than 5G will be in the U.S. None of these countries has reported any harmful interference with aviation equipment from these commercial deployments, as the Federal Aviation Administration recently confirmed.[0] [0] https://ecfsapi.fcc.gov/file/1103192305940/211103%20CTIA%20Ex%20Parte%20on%20C-Band%20International%20Deployments.pdf https://ecfsapi.fcc.gov/file/1103192305940/211103%20CTIA%20E...
  - p_l 5y ago
    The very nice weasel wording used tries to make it sound like 40 countries approved above 3.8GHz, but the further paragraphs explain that only japan did so, without going into much detail other than the low guard band. The FAA complaint is about 3.8-3.98GHz, and all other examples involve no frequency allocations above 3.8GHz
    - gormandizer 5y ago
      Absolutely zero weasel wording. The initial deployment of C-Band in the US is 100 MHz of spectrum from 3.7 to 3.8 GHz. The remainder of the auctioned C-Band from 3.8 to 3.98 cannot be deployed until the incumbent satellite operators clear the band on or before December 2023. For 2 years there will be a 400MHz guard band.

deleted 5y ago

[deleted]

can16358p 5y ago

Because there is no evidence of any interference. Boeing and Airbus are requesting something without showing any evidence, which could have been easily detected in a test environment.

onphonenow 5y ago
Their views aren't even that logical. You already need multiple radar altimeters on ONE plane much closer physically and spectrum wise than 5G. In busy airports you already have multiple altimeters operating again closely physically. Anyways, even if there is interference, it's actually boeing that should fix their systems to operate within their assigned band (ie, operate in the middle of the band, and reject signals outside of band). This is radio 101 stuff.
- p_l 5y ago
  Only one radar altimeter is generally operational at a time (transmitting), due to high bandwidth involved, and latest ICAO working group reports are "we don't know yet if it's safe with current equipment, retrofitting will take years as they can't even start designing new models till interference data is available, and that countries are implementing temporary mitigations in 5G base stations"
  - onphonenow 5y ago
    That's where we find how technically incompetent ICAO is I suppose? Something that has been a decade in the making, they haven't been able to conduct basic tests on. I'm a lay person, but can easily think of basic tests that would help resolve this question. "On a large aircraft two or three altimeter systems are employed and these systems could utilize a frequency offset of 5 MHz to 10 MHz." Something is rotten with the regulators.
    - p_l 5y ago
      Radio altimeters have bandwidth as high as 170MHz, and a lot of work goes into ensuring other devices in 4.2-4.4 band do not interfere with them. The fact that certain radio systems can utilize low bandwidth does not mean every system is like them.

stefan_ 5y ago

The sibling comments here are also correct of course but keep in mind that 5G, excluding stuff like mmWave, does not prescribe any particular frequency band to use and can work on just about any. Regulators will find some slice of free frequency space somewhere between roughly 1 GHz to 5 GHz and auction it off and then carriers and device manufacturers will make 5G run in that band. The iPhone 13 for example can use literally 30 different 5G bands on the US models.