Discuss

Bill

On Tuesday, 18 January 2022 at 19:46:25 UTC, wrightsaerials@aol.com wrote:
> Discuss
>
> Bill

The US airlines are flapping, well not literally, about 5G mmWave at ~28GHz and up.

They claim it will interfere with avionics (radio altimeters?), so the FAA has suspended introduction for six months.

As it happens there is no mmWave in Europe and 5G phones sold here don't [yet] have it in, so no need to duck when a plane goes over.

R. Mark Clayton <notyalckram@gmail.com> wrote:
> On Tuesday, 18 January 2022 at 19:46:25 UTC, wrightsaerials@aol.com wrote:
>> Discuss
>>
>> Bill
>
> The US airlines are flapping, well not literally, about 5G mmWave at ~28GHz and up.
>
> They claim it will interfere with avionics (radio altimeters?), so the
> FAA has suspended introduction for six months.
>
> As it happens there is no mmWave in Europe and 5G phones sold here don't
> [yet] have it in, so no need to duck when a plane goes over.
>

Not 28GHz but much lower down in C band

https://www.icao.int/safety/FSMP/MeetingDocs/FSMP%20WG11/IP/FSMP-WG11-IP08_ICAO%20Flight%20Operations%20Panel%20and%20IATA%20%20IFALPA%205G%20problem%20statement.pdf

Radar altimeters (RA), operating at 4.2-4.4 GHz, are the only sensors
onboard a civil aircraft which provide a direct measurement of the
clearance height of the aircraft over the terrain or other obstacles (i.e.
the Above Ground Level - AGL - information).

The RA systems’ input is required and used by many aircraft systems when
AGL is below 2500 ft. Any failures or interruptions of these sensors can
therefore lead to incidents with catastrophic outcome, potentially
resulting in multiple fatalities. The radar altimeters also play a crucial
role in providing situational awareness to the flight crew. The
measurements from the radar altimeters are also used by Automatic Flight
Guidance and Control Systems (AFGCS) during instrument approaches, and to
control the display of information from other systems, such as Predictive
Wind Shear (PWS), the Engine-Indicating and Crew-Alerting System (EICAS),
and Electronic Centralized Aircraft Monitoring (ECAM) systems, to the
flight crew.

There is a major risk that 5G telecommunications systems in the 3.7–3.98
GHz band will cause harmful interference to radar altimeters on all types
of civil aircraft—including commercial transport airplanes; business,
regional, and general aviation airplanes; and both transport and general
aviation helicopters. If there is no proper mitigation, this risk has the
potential for broad impacts to aviation operations in the United States as
well as in other regions where the 5G network is being implemented next to
the 4.2-4.4 GHz frequency band.

An example listed further below shows, that the identified risk has
materialized during certain airline operations impacted by similar
interference.

(See link for more info)

See also https://www.faa.gov/5g

On Tue 18/01/2022 21:13, Tweed wrote:
> R. Mark Clayton <notyalckram@gmail.com> wrote:
>> On Tuesday, 18 January 2022 at 19:46:25 UTC, wrightsaerials@aol.com wrote:
>>> Discuss
>>>
>>> Bill
>>
>> The US airlines are flapping, well not literally, about 5G mmWave at ~28GHz and up.
>>
>> They claim it will interfere with avionics (radio altimeters?), so the
>> FAA has suspended introduction for six months.
>>
>> As it happens there is no mmWave in Europe and 5G phones sold here don't
>> [yet] have it in, so no need to duck when a plane goes over.
>>
>
> Not 28GHz but much lower down in C band
>
> https://www.icao.int/safety/FSMP/MeetingDocs/FSMP%20WG11/IP/FSMP-WG11-IP08_ICAO%20Flight%20Operations%20Panel%20and%20IATA%20%20IFALPA%205G%20problem%20statement.pdf
>
> Radar altimeters (RA), operating at 4.2-4.4 GHz, are the only sensors
> onboard a civil aircraft which provide a direct measurement of the
> clearance height of the aircraft over the terrain or other obstacles (i.e.
> the Above Ground Level - AGL - information).
>
> The RA systems’ input is required and used by many aircraft systems when
> AGL is below 2500 ft. Any failures or interruptions of these sensors can
> therefore lead to incidents with catastrophic outcome, potentially
> resulting in multiple fatalities. The radar altimeters also play a crucial
> role in providing situational awareness to the flight crew. The
> measurements from the radar altimeters are also used by Automatic Flight
> Guidance and Control Systems (AFGCS) during instrument approaches, and to
> control the display of information from other systems, such as Predictive
> Wind Shear (PWS), the Engine-Indicating and Crew-Alerting System (EICAS),
> and Electronic Centralized Aircraft Monitoring (ECAM) systems, to the
> flight crew.
>
> There is a major risk that 5G telecommunications systems in the 3.7–3.98
> GHz band will cause harmful interference to radar altimeters on all types
> of civil aircraft—including commercial transport airplanes; business,
> regional, and general aviation airplanes; and both transport and general
> aviation helicopters. If there is no proper mitigation, this risk has the
> potential for broad impacts to aviation operations in the United States as
> well as in other regions where the 5G network is being implemented next to
> the 4.2-4.4 GHz frequency band.
>
> An example listed further below shows, that the identified risk has
> materialized during certain airline operations impacted by similar
> interference.
>
> (See link for more info)
>
>
> See also https://www.faa.gov/5g
>

Am I mistaken or don't commercial aircraft have wi-fi on board these
days (I don't fly)? They are wideband in nearby frequency ranges and I
would guess perhaps phone/tablets are not as spectrally clean as the
avionics equipment and could splatter all over it?

Woody <harrogate3@ntlworld.com> wrote:
> On Tue 18/01/2022 21:13, Tweed wrote:
>> R. Mark Clayton <notyalckram@gmail.com> wrote:
>>> On Tuesday, 18 January 2022 at 19:46:25 UTC, wrightsaerials@aol.com wrote:
>>>> Discuss
>>>>
>>>> Bill
>>>
>>> The US airlines are flapping, well not literally, about 5G mmWave at ~28GHz and up.
>>>
>>> They claim it will interfere with avionics (radio altimeters?), so the
>>> FAA has suspended introduction for six months.
>>>
>>> As it happens there is no mmWave in Europe and 5G phones sold here don't
>>> [yet] have it in, so no need to duck when a plane goes over.
>>>
>>
>> Not 28GHz but much lower down in C band
>>
>> https://www.icao.int/safety/FSMP/MeetingDocs/FSMP%20WG11/IP/FSMP-WG11-IP08_ICAO%20Flight%20Operations%20Panel%20and%20IATA%20%20IFALPA%205G%20problem%20statement.pdf
>>
>> Radar altimeters (RA), operating at 4.2-4.4 GHz, are the only sensors
>> onboard a civil aircraft which provide a direct measurement of the
>> clearance height of the aircraft over the terrain or other obstacles (i.e.
>> the Above Ground Level - AGL - information).
>>
>> The RA systems’ input is required and used by many aircraft systems when
>> AGL is below 2500 ft. Any failures or interruptions of these sensors can
>> therefore lead to incidents with catastrophic outcome, potentially
>> resulting in multiple fatalities. The radar altimeters also play a crucial
>> role in providing situational awareness to the flight crew. The
>> measurements from the radar altimeters are also used by Automatic Flight
>> Guidance and Control Systems (AFGCS) during instrument approaches, and to
>> control the display of information from other systems, such as Predictive
>> Wind Shear (PWS), the Engine-Indicating and Crew-Alerting System (EICAS),
>> and Electronic Centralized Aircraft Monitoring (ECAM) systems, to the
>> flight crew.
>>
>> There is a major risk that 5G telecommunications systems in the 3.7–3.98
>> GHz band will cause harmful interference to radar altimeters on all types
>> of civil aircraft—including commercial transport airplanes; business,
>> regional, and general aviation airplanes; and both transport and general
>> aviation helicopters. If there is no proper mitigation, this risk has the
>> potential for broad impacts to aviation operations in the United States as
>> well as in other regions where the 5G network is being implemented next to
>> the 4.2-4.4 GHz frequency band.
>>
>> An example listed further below shows, that the identified risk has
>> materialized during certain airline operations impacted by similar
>> interference.
>>
>> (See link for more info)
>>
>>
>> See also https://www.faa.gov/5g
>>
>
> Am I mistaken or don't commercial aircraft have wi-fi on board these
> days (I don't fly)? They are wideband in nearby frequency ranges and I
> would guess perhaps phone/tablets are not as spectrally clean as the
> avionics equipment and could splatter all over it?
>

I think the worry is that an altimeter filter that allows 4.2 GHz won’t
reject 3.98 GHz sufficiently. They are concerned about the power of the
base station, and if you read the FAA document, the radiation pattern of
the base station antennas (not sufficiently tilted downwards).

WiFi in planes is much further away in frequency and very much lower in
power and is largely contained by the cabin structure . It also tends to
get turned off during takeoff and landing.

Yes is it not the case that in the US 5g is using more bands and lower
frequencies in some countries.
Its interesting to note that as well as 118 to 136Mhz am for aircraft,
there are some allocations in the 400 mhz area for ground vehicles, and some
odd ones for ILS systems as well.
I also note that as well as satellite linked comms for long haul they still
use short wave frequencies for this a lot, you can hear them on ssb. The
ones I normally hear are Shanwick, but often Gander and the one in the
Azores as well.
Brian

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"williamwright" <wrightsaerials@f2s.com> wrote in message
news:j4ojoeF1h59U1@mid.individual.net...
> Discuss
>
> Bill
>

Is that not a little high for communications?
In the clear its only going to be line of sight.
Also, a lot of satellites use frequencies up there for remote sensing too,
so speckles all over the pictures on very expensive sats would I assume not
be welcome either!
Was not a problem recently in Japan when somebody tried to do uplinks to
sats from individual dishes on houses? Brian

--

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Blind user, so no pictures please
Note this Signature is meaningless.!
"R. Mark Clayton" <notyalckram@gmail.com> wrote in message
news:16f08189-074f-4fd5-a808-746f4af68766n@googlegroups.com...
> On Tuesday, 18 January 2022 at 19:46:25 UTC, wrightsaerials@aol.com wrote:
>> Discuss
>>
>> Bill
>
> The US airlines are flapping, well not literally, about 5G mmWave at
> ~28GHz and up.
>
> They claim it will interfere with avionics (radio altimeters?), so the FAA
> has suspended introduction for six months.
>
> As it happens there is no mmWave in Europe and 5G phones sold here don't
> [yet] have it in, so no need to duck when a plane goes over.

That sounds more feasible but its still a very high frequency for mobile
comms.
I think 5g is ill thought out in the first place, its a mish-mash of bits
of spectrum which is spare and who was responsible for looking at the world
usage and possible cross mod effects, or de-sensing for that matter. One of
the countermeasures we were looking at at Racal in the 80s for military use
was interfering with radio altimeters to cause cruise missiles problems as
well as helicopters.
Its no big secret how such things work after all.
Brian

--

This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...
briang1@blueyonder.co.uk
Blind user, so no pictures please
Note this Signature is meaningless.!
"Tweed" <usenet.tweed@gmail.com> wrote in message
news:ss7ahl$1nk$1@dont-email.me...
> R. Mark Clayton <notyalckram@gmail.com> wrote:
>> On Tuesday, 18 January 2022 at 19:46:25 UTC, wrightsaerials@aol.com
>> wrote:
>>> Discuss
>>>
>>> Bill
>>
>> The US airlines are flapping, well not literally, about 5G mmWave at
>> ~28GHz and up.
>>
>> They claim it will interfere with avionics (radio altimeters?), so the
>> FAA has suspended introduction for six months.
>>
>> As it happens there is no mmWave in Europe and 5G phones sold here don't
>> [yet] have it in, so no need to duck when a plane goes over.
>>
>
> Not 28GHz but much lower down in C band
>
> https://www.icao.int/safety/FSMP/MeetingDocs/FSMP%20WG11/IP/FSMP-WG11-IP08_ICAO%20Flight%20Operations%20Panel%20and%20IATA%20%20IFALPA%205G%20problem%20statement.pdf
>
> Radar altimeters (RA), operating at 4.2-4.4 GHz, are the only sensors
> onboard a civil aircraft which provide a direct measurement of the
> clearance height of the aircraft over the terrain or other obstacles (i.e.
> the Above Ground Level - AGL - information).
>
> The RA systems' input is required and used by many aircraft systems when
> AGL is below 2500 ft. Any failures or interruptions of these sensors can
> therefore lead to incidents with catastrophic outcome, potentially
> resulting in multiple fatalities. The radar altimeters also play a crucial
> role in providing situational awareness to the flight crew. The
> measurements from the radar altimeters are also used by Automatic Flight
> Guidance and Control Systems (AFGCS) during instrument approaches, and to
> control the display of information from other systems, such as Predictive
> Wind Shear (PWS), the Engine-Indicating and Crew-Alerting System (EICAS),
> and Electronic Centralized Aircraft Monitoring (ECAM) systems, to the
> flight crew.
>
> There is a major risk that 5G telecommunications systems in the 3.7-3.98
> GHz band will cause harmful interference to radar altimeters on all types
> of civil aircraft-including commercial transport airplanes; business,
> regional, and general aviation airplanes; and both transport and general
> aviation helicopters. If there is no proper mitigation, this risk has the
> potential for broad impacts to aviation operations in the United States as
> well as in other regions where the 5G network is being implemented next to
> the 4.2-4.4 GHz frequency band.
>
> An example listed further below shows, that the identified risk has
> materialized during certain airline operations impacted by similar
> interference.
>
> (See link for more info)
>
>
> See also https://www.faa.gov/5g
>

R. Mark Clayton wrote:

> wrightsaerials wrote:
>
>> Discuss
>
> The US airlines are flapping, well not literally, about 5G mmWave at ~28GHz and up.

The "flap" I've seen has not been regarding mmWave but the 3550-3980 MHz band
and possible interference with radio altimeters between 4200 and 4400 MHz,
I've seen others rebut it.

Also the n77 & n79 bands run much closer directly below 4200 and directly above
4400.

On Wednesday, 19 January 2022 at 07:30:42 UTC, Brian Gaff (Sofa) wrote:
> Is that not a little high for communications?

No current satellite transceivers operate 10GHz down and usually ~30GHz up.

> In the clear its only going to be line of sight.

Yep.

> Also, a lot of satellites use frequencies up there for remote sensing too,
> so speckles all over the pictures on very expensive sats would I assume not
> be welcome either!

They are hundred(s) of km up, not flying 1km overhead.

> Was not a problem recently in Japan when somebody tried to do uplinks to
> sats from individual dishes on houses? Brian

Dunno.

> --
SNIP
> >
> > The US airlines are flapping, well not literally, about 5G mmWave at
> > ~28GHz and up.
> >
> > They claim it will interfere with avionics (radio altimeters?), so the FAA
> > has suspended introduction for six months.
> >
> > As it happens there is no mmWave in Europe and 5G phones sold here don't
> > [yet] have it in, so no need to duck when a plane goes over.

On Wednesday, 19 January 2022 at 09:20:36 UTC, Andy Burns wrote:
> R. Mark Clayton wrote:
>
> > wrightsaerials wrote:
> >
> >> Discuss
> >
> > The US airlines are flapping, well not literally, about 5G mmWave at ~28GHz and up.
> The "flap" I've seen has not been regarding mmWave but the 3550-3980 MHz band
> and possible interference with radio altimeters between 4200 and 4400 MHz,
> I've seen others rebut it.
>
> Also the n77 & n79 bands run much closer directly below 4200 and directly above
> 4400.

Yes - better information makes that clear. In the UK 3g4Hz to 3G8Hz is used for 5G.

On Wednesday, 19 January 2022 at 12:51:26 UTC, R. Mark Clayton wrote:
> On Wednesday, 19 January 2022 at 09:20:36 UTC, Andy Burns wrote:
> > R. Mark Clayton wrote:
> >
> > > wrightsaerials wrote:
> > >
> > >> Discuss
> > >
> > > The US airlines are flapping, well not literally, about 5G mmWave at ~28GHz and up.
> > The "flap" I've seen has not been regarding mmWave but the 3550-3980 MHz band
> > and possible interference with radio altimeters between 4200 and 4400 MHz,
> > I've seen others rebut it.
> >
> > Also the n77 & n79 bands run much closer directly below 4200 and directly above
> > 4400.
> Yes - better information makes that clear. In the UK 3g4Hz to 3G8Hz is used for 5G.

OTOH BA not flying to USA: -
https://bmmagazine.co.uk/news/british-airways-cancels-us-flights-over-5g-safety-fears

On 19/01/2022 06:54, Tweed wrote:
> Woody <harrogate3@ntlworld.com> wrote:
>> Am I mistaken or don't commercial aircraft have wi-fi on board these
>> days (I don't fly)? They are wideband in nearby frequency ranges and I
>> would guess perhaps phone/tablets are not as spectrally clean as the
>> avionics equipment and could splatter all over it?
>
> WiFi in planes is much further away in frequency and very much lower in
> power and is largely contained by the cabin structure . It also tends to
> get turned off during takeoff and landing.

How do planes get the backhaul connection to the internet to provide a
wifi connection? Do they have receivers that can track the satellites
that provide satellite internet feeds to buildings on the ground that
can't get decent xDSL broadband?

I've not been on a plane since I've owned a mobile phone (so over 20
years) and I hadn't realised that internet on a plane was even possible.
Do planes provide a femtocell for voice calls on a mobile via the same
backhaul? I'd always assumed that "flight mode" was provided mobiles
because they weren't allowed to have voice, mobile internet or wifi
turned on *at all*, rather than being allowed except during take-off and
landing.

NY <me@privacy.net> wrote:
> On 19/01/2022 06:54, Tweed wrote:
>> Woody <harrogate3@ntlworld.com> wrote:
>>> Am I mistaken or don't commercial aircraft have wi-fi on board these
>>> days (I don't fly)? They are wideband in nearby frequency ranges and I
>>> would guess perhaps phone/tablets are not as spectrally clean as the
>>> avionics equipment and could splatter all over it?
>>
>> WiFi in planes is much further away in frequency and very much lower in
>> power and is largely contained by the cabin structure . It also tends to
>> get turned off during takeoff and landing.
>
> How do planes get the backhaul connection to the internet to provide a
> wifi connection? Do they have receivers that can track the satellites
> that provide satellite internet feeds to buildings on the ground that
> can't get decent xDSL broadband?
>
> I've not been on a plane since I've owned a mobile phone (so over 20
> years) and I hadn't realised that internet on a plane was even possible.
> Do planes provide a femtocell for voice calls on a mobile via the same
> backhaul? I'd always assumed that "flight mode" was provided mobiles
> because they weren't allowed to have voice, mobile internet or wifi
> turned on *at all*, rather than being allowed except during take-off and
> landing.
>

Where a plane does have inflight WiFi the back haul is to geostationary
satellites. It is WiFi rather than a femto cell, so no native voice calls.
Latency is terrible and throughput rates low, so no chance of running over
the top voice via the likes of WhatsApp. It’s adequate for messaging, basic
email etc.

I’ve never seen under the pod enclosure on the top of the plane, but I’m
assuming the antenna is some sort of phased array rather than a
mechanically steered dish.

The last time I used it was on a Norwegian service from Bergen. It was good
enough to load Google maps and it was interesting to see where we were and
what was to be seen out of the window in more detail than the inflight map
display shows.

Having the access points for the WiFi in the cabin keeps the RF power
levels low. Much better than a cellular handset upping its transmit power
levels trying to maintain a link to a ground base station.