Posted on 12/22/2021 6:46:29 AM PST by lightman
4G seems to work just fine. Don’t dump it if there could be safety issues.
If 5G causes planes to crash, then why are their no issues in all the countries that have had 5G up and running for a year now? Canada and Europe all have started using those frequencies without noticeable issues.
Cellular tissue damage, especially the eyes.
Tough times for congress critters. Which lobbyist will pay the most............................
A retrofit with the addition of a highpass or BP filter would solve this, but, that would mean spending a little money. This shortfall in RALT (radio altimeter) performance has been known for quite awhile now ...
Hypochondriacs cringe, in fear of the 5G rollout...
re: “Cellular tissue damage, especially the eyes. “
If you’re dumb enough to sit face-first against the base station antenna on the phone pole out back in your alley or along the street ...
Maybe Boeing needs some new suppliers.
The thesis is that 5G frequency bands will interfere with military band which is true.
The the unscientific science author elaborates with a non sequitur: “…exposing multitudes of people to millimeter-wave radiation at close range.”
I see you’ve read the studies....
I think I’ll wait until 6G comes out.......................
One of the first things they taught us in Microwave Measurements in Tech School was:
Never look into the waveguide...................
Applicable technical standard for radio altimeters:
RALT
Radio Altimeter
Recommendation ITU-R M.2059-0 (02/2014)
https://www.itu.int/dms_pubrec/itu-r/rec/m/R-REC-M.2059-0-201402-I!!PDF-E.pdf
Pg 21 “RF selectivity for radio altimeters”
FMCW radar altimeters receivers employ a bandpass filter which is meant to reject high intensity radiated field (HIRF) transmissions outside the operating band from degrading or damaging the radio altimeter performance. However, the bandpass filter has limited ability to reject transmissions close to the desired band. As a result, altimeter performance may be affected by signals at the edge of the band.
Tables 1 and 2 provide technical characteristics for representative analogue and digital FMCW radio altimeters.
Where is the FCC in all of this?
THIS ‘deficiency’ in RALTs has nbeen known for awhile ... note the date on this article.
- - - - - - - - - - - - - - -
Design Improves 4.3-GHz Radio Altimeter Accuracy
June 16, 2005
This radio altimeter employs a dual-channel (quadrature) homodyne receiver to achieve improved accuracy in the standard 4.3-GHz allocated band for small aircraft and UAVs.
This radio altimeter employs a dualchannel (quadrature) homodyne receiver to achieve improved accuracy in the standard 4.3GHz allocated band for small aircraft and UAVs.
Shortrange radio altimeters are important safety and navigational tools in small aircraft. Usually designed as shortrange frequency modulated (FM) radars in the 4.2 to 4.4GHz band,1 their main applications are for instrument based approaches and landings for larger commercial aircraft, although they are also suitable for smaller aircraft and even unmanned air vehicles (UAVs). The accuracy and resolution of aviation altimeters is usually limited to a few feet due to the limited availability of bandwidth (200 MHz) in the 4.3GHz range. Fortunately, by adding a second receiver channel in quadrature, it may be possible to dramatically improve the resolution and accuracy of these shortrange radio altimeters.
And the filter I ref’d before:
Qualcomm’s New Filters Could End Airlines’ Fight Against 5G
The new UltraBAW filters can speed up home 5G internet, too.
https://www.pcmag.com/news/qualcomms-new-filters-could-end-airlines-fight-against-5g
The airwaves are getting crowded. Too crowded, for some. New C-band frequencies that are critical for 5G back onto the airwaves used by airplanes for their radio altimeters, and face onto the ones used by 5G Wi-Fi. Worries about interference have already caused the Canadian government to restrict the use of those frequencies around airports.
Qualcomm today announced a potential solution: A new set of filters called UltraBAW, designed to make sure C-band receivers and transmitters only work on the C-band.
“Filters are key,” says Nitin Dhiman, product marketing director at Qualcomm. “Even though they’re tiny, they’re fundamental to the overall performance of any wireless system.”
Existing C-band devices and transmitters already have filters, of course. Qualcomm argues that its new filters have a sharper cutoff for frequencies over 3GHz than existing ones, meaning there won’t need to be guard bands as broad as there are now around transmissions at those frequencies.
Guard bands and filters are at the heart of the C-band-versus-aviation controversy, where the aviation industry has given shifting arguments that either airplanes’ altimeters will be confused by C-band transmissions, that the C-band towers leak out of their assigned bands, or both. So far, the FCC has rejected the airline industry arguments, while Canadian regulators have put exclusion and low-power zones for C-band use around airports.
Boeing and Airbus are not exactly fringe conspiracy theorists.
I have first hand experience with that. My wireless system for my bass is now illegal because it was manufactured at a time when it could legally use the frequency it uses. But it became illegal (I had to throw it away) because the frequency was “bought” for cell phone use (or something like that) with something like a one year grace period.
I hope all those airplanes don’t become “throw away” because of this new change.
re: “One of the first things they taught us in Microwave Measurements in Tech School was”
Similar to the caution when working with lasers - “Do not state at laser beam with the one good eye” ...
Is this story several years old? Because 5G coverage has already been “rolled out” around here. I haven’t seen any Boeing planes falling out of the air. Or is Boeing planning to blame the 737 MAX problems on 5G?
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