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I see a lot people blaming boeing here? These sensors radar sensors were made before even the FCC allocated the 5G spectrum. Let's also not forget 5G equipment

by anfilt 5y ago

I see a lot people blaming boeing here? These sensors radar sensors were made before even the FCC allocated the 5G spectrum. Let's also not forget 5G equipment will emit outside of its assigned spectrum even with a buffer zone between frequencies. Especially when you consider the harmonics. Now each order of harmonic gets weaker from primary frequency. As for these altimeter sensors anyone have a datasheet for them? Quite curious what the recommended noise floor for these are?

manquer 5y ago
All equipment can emit outside the allocated frequencies, which is why you have band pass filters . FAA is really the problem not Boeing, like any company they only did the bare minimum required to get certification . Had FAA they mandated stronger specs initially or at-least forced Boeing to upgrade in the last 10 years this was being discussed and allocated, this won't be a problem. That will be expensive for Airlines(grounding loss of revenue) and Boeing (recall,certification and upgrade) nobody wants to foot the bill so FAA kept delaying . Time and again we have seen FAA favor the industry even at the cost of lives (like with 737-MAX grounding) so this is not all that surprising from them
- anfilt 5y ago
  We are talking about radar here the receiver will be receiving weak signals that are reflected. They may also have slight shifting in frequency due to reflection and the doppler effect. The noise floor is much lower for radar than communications. A radar receiver also will generally read a wider frequency band than communications. 200Mhz between frequency bands may seem like a lot for communication purposes, but that is not necessarily true for radar. Also you can't make a perfect band pass filter, also for radar the band your going to be filtering is gonna be wider to begin with. Also all transmitters will emit higher order harmonics of the primary frequency, if the broadcast power is high enough those harmonics could very well be above the noise floor of other frequencies.
  - manquer 5y ago
    There are altimeters which already are being used including by Boeing which perfectly pass the required specs. Nobody including FAA / Boieng are claiming technically it is impossible or will take very long to develop. The FAA is only calling out 737s after clearing them in this statement . They had said on 20th Jan "Airplane models with one of the 13 cleared altimeters including all Boeing 717, 737, 747, 757, 767, 777, 787, MD-10/-11; all Airbus A300, A310, A319, A320, A330, A340, A350 and A380 models" [1] and now backtracking They had adequate time to plan and roll it out to affected planes and they have not for the same reason telecom and FTC are upset -- money . Airlines/Boeing/ FAA do not want to foot the bill of this upgrade. Telecom companies spent $70 Billion on the spectrum and delays are costing them so they are upset. --- [1] Jan 20, 2022: https://www.faa.gov/newsroom/faa-statements-5g https://www.faa.gov/newsroom/faa-statements-5g
    - p_l 5y ago
      All of those altimeters are up to spec. It's just that the spec never included "must magically filter out high power leakage from 5G towers that won't exist for 30 years", and making a filter for radar altimeter is much, much harder than for telecommunication equipment.
      - manquer 5y ago
        It has nothing to do with whether they were up to spec originally and now don't because telecom did something. FAA on Jan 20th of this year made a statement saying all these planes were approved to use under current new conditions for 5G. Now have since rolled back that for 747s(on Jan 25th) and 737s(23 Feb/27th Jan). Read their statements linked carefully again. It tells FAA is not competently handling the situation. First they are caught totally unprepared for the 5G rollout after having years of notice, then issue approvals and are rolling back said approvals. At this point I am not inclined to believe they know what they are talking about at all.
        p_l 5y ago
        New data invalidating old data happens all the time in aviation, and they have to deal with increasing number of 5G transmitter models operating in new environments. It's not something you can do easily. In fact, apparently issues started cropping up with 400MHz guard band used in most of europe, when the towers malfunction.

by anfilt 5y ago

manquer 5y ago

All equipment can emit outside the allocated frequencies, which is why you have band pass filters . FAA is really the problem not Boeing, like any company they only did the bare minimum required to get certification . Had FAA they mandated stronger specs initially or at-least forced Boeing to upgrade in the last 10 years this was being discussed and allocated, this won't be a problem. That will be expensive for Airlines(grounding loss of revenue) and Boeing (recall,certification and upgrade) nobody wants to foot the bill so FAA kept delaying . Time and again we have seen FAA favor the industry even at the cost of lives (like with 737-MAX grounding) so this is not all that surprising from them

anfilt 5y ago
We are talking about radar here the receiver will be receiving weak signals that are reflected. They may also have slight shifting in frequency due to reflection and the doppler effect. The noise floor is much lower for radar than communications. A radar receiver also will generally read a wider frequency band than communications. 200Mhz between frequency bands may seem like a lot for communication purposes, but that is not necessarily true for radar. Also you can't make a perfect band pass filter, also for radar the band your going to be filtering is gonna be wider to begin with. Also all transmitters will emit higher order harmonics of the primary frequency, if the broadcast power is high enough those harmonics could very well be above the noise floor of other frequencies.
- manquer 5y ago
  There are altimeters which already are being used including by Boeing which perfectly pass the required specs. Nobody including FAA / Boieng are claiming technically it is impossible or will take very long to develop. The FAA is only calling out 737s after clearing them in this statement . They had said on 20th Jan "Airplane models with one of the 13 cleared altimeters including all Boeing 717, 737, 747, 757, 767, 777, 787, MD-10/-11; all Airbus A300, A310, A319, A320, A330, A340, A350 and A380 models" [1] and now backtracking They had adequate time to plan and roll it out to affected planes and they have not for the same reason telecom and FTC are upset -- money . Airlines/Boeing/ FAA do not want to foot the bill of this upgrade. Telecom companies spent $70 Billion on the spectrum and delays are costing them so they are upset. --- [1] Jan 20, 2022: https://www.faa.gov/newsroom/faa-statements-5g https://www.faa.gov/newsroom/faa-statements-5g
  - p_l 5y ago
    All of those altimeters are up to spec. It's just that the spec never included "must magically filter out high power leakage from 5G towers that won't exist for 30 years", and making a filter for radar altimeter is much, much harder than for telecommunication equipment.
    - manquer 5y ago
      It has nothing to do with whether they were up to spec originally and now don't because telecom did something. FAA on Jan 20th of this year made a statement saying all these planes were approved to use under current new conditions for 5G. Now have since rolled back that for 747s(on Jan 25th) and 737s(23 Feb/27th Jan). Read their statements linked carefully again. It tells FAA is not competently handling the situation. First they are caught totally unprepared for the 5G rollout after having years of notice, then issue approvals and are rolling back said approvals. At this point I am not inclined to believe they know what they are talking about at all.
      - p_l 5y ago
        New data invalidating old data happens all the time in aviation, and they have to deal with increasing number of 5G transmitter models operating in new environments. It's not something you can do easily. In fact, apparently issues started cropping up with 400MHz guard band used in most of europe, when the towers malfunction.