Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[David Fernández]

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Both AST and Starlink are reporting speeds of around 10 Mbit/s. Those are
not like the service Globalstar is providing to Apple phones for just
emergency texts.

https://uk.pcmag.com/networking/151288/spacexs-cellular-starlink-hits-17mbps-download-speed-to-android-phone

From: David Lang <david@lang.hm>
To: Eugene Y Chang <eugene.chang@ieee.org>
Cc: Frantisek Borsik <frantisek.borsik@gmail.com>,  Dave Taht via
        Starlink <starlink@lists.bufferbloat.net>
Subject: Re: [Starlink] SpaceX/Starlink says it's ready for a fall
        satellite-to-cell service with T-Mobile
Message-ID: <o29q52qp-p7p8-711q-q0ns-57or8866854n@ynat.uz>
Content-Type: text/plain; charset="iso8859-7"; Format="flowed"

This is a fallback that will only be if there is no other coverage, and
will be
a poor data rate.

I would expect that the impact to the phone battery would be less than the
phone
continually searching for a tower

Also, SpaceX has pushed back, according to them this isn't observed
interference
with their signals, instead they reconfigured a satellite to the
direct-to-phone
frequencies and were able to detect them

we'll see what the real story is.

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[Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[Frantisek Borsik]

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   - SpaceX & T-Mobile intend to launch direct-to-device (D2D)
   satellite servicethis fall
   - An analyst told us that will give them an 18- to 24-month lead over
   some rivals
   - AT&T & Verizon are still backing AST SpaceMobile as an alternative


https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile

All the best,

Frank

Frantisek (Frank) Borsik



https://www.linkedin.com/in/frantisekborsik

Signal, Telegram, WhatsApp: +421919416714

iMessage, mobile: +420775230885

Skype: casioa5302ca

frantisek.borsik@gmail.com

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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[the keyboard of geoff goodfellow]

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it will be Most Interesting to see if/how this 43 page
@omnispace presentation to the @FCC of the observed interference from
the @Starlink D2D testing will affect those intended launch plans or not
➔➔https://x.com/no_privacy/status/1792589907115876525

On Mon, Jun 3, 2024 at 11:09 AM Frantisek Borsik via Starlink <
starlink@lists.bufferbloat.net> wrote:

>
>    - SpaceX & T-Mobile intend to launch direct-to-device (D2D)
>    satellite servicethis fall
>    - An analyst told us that will give them an 18- to 24-month lead over
>    some rivals
>    - AT&T & Verizon are still backing AST SpaceMobile as an alternative
>
>
>
> https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile
>
>
-- 
Geoff.Goodfellow@iconia.com
living as The Truth is True

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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[Alexandre Petrescu]

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Le 03/06/2024 à 20:17, the keyboard of geoff goodfellow via Starlink a 
écrit :
> it will be Most Interesting to see if/how this 43 page 
> @omnispace presentation to the @FCC of the observed interference from 
> the @Starlink D2D testing will affect those intended launch plans or not
> ➔➔https://x.com/no_privacy/status/1792589907115876525

Fair enough.  Interesting to see.

The interference aspect might come not only from omnispace vs spacex, 
but there are other sats up there using ground cell frequencies.  I 
heard last September about vodafone and bluewalker using also unmodified 
smartphones, i.e. ground cell frequencies.  Further, I also heard about 
recent russian 5G NTN satellite put up there in the orbit.  I would not 
be surprised to hear that China, or other country, also has 5G sats up 
there just to listen, just in case.  Not to mention these direct 
bluetooth ground-to-sat experiments.

Interference might be intentional or unintentional.

It will be advantageous to see how this Direct-to-Cell (or to 
smartphone, or to device) feature can be used in some useful manner, 
such as crime scene resolution where there is no ground 'tower' but some 
sat was there and heard that this or that smartphone was connected or not.

Alex

>
> On Mon, Jun 3, 2024 at 11:09 AM Frantisek Borsik via Starlink 
> <starlink@lists.bufferbloat.net> wrote:
>
>       * SpaceX & T-Mobile intend to launch direct-to-device (D2D)
>         satellite servicethis fall
>       * An analyst told us that will give them an 18- to 24-month lead
>         over some rivals
>       * AT&T & Verizon are still backing AST SpaceMobile as an alternative
>
>
>     https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile
>
>
>
> -- 
> Geoff.Goodfellow@iconia.com
> living as The Truth is True
>
>
> _______________________________________________
> Starlink mailing list
> Starlink@lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/starlink

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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[Eugene Y Chang]

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I found this line in the article very interesting: The larger 2nd generation SpaceX satellites can connect to the majority of T-Mobile’s 4G and 5G phones over its 1900 MHz spectrum.

It is exciting a subscriber does not need to buy a new phone.
What is the expected impact to the phone’s battery life?
Any speculations?

Gene
----------------------------------------------
Eugene Chang
eugene.chang@ieee.org
o 781-799-0233




> On Jun 3, 2024, at 8:08 AM, Frantisek Borsik via Starlink <starlink@lists.bufferbloat.net> wrote:
> 
> SpaceX & T-Mobile intend to launch direct-to-device (D2D) satellite servicethis fall
> An analyst told us that will give them an 18- to 24-month lead over some rivals
> AT&T & Verizon are still backing AST SpaceMobile as an alternative
> 
> https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile <https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile>
> 
> All the best,
> 
> Frank
> 
> Frantisek (Frank) Borsik
> 
> 
> 
> https://www.linkedin.com/in/frantisekborsik <https://www.linkedin.com/in/frantisekborsik>
> Signal, Telegram, WhatsApp: +421919416714
> 
> iMessage, mobile: +420775230885
> 
> Skype: casioa5302ca
> 
> frantisek.borsik@gmail.com <mailto:frantisek.borsik@gmail.com>_______________________________________________
> Starlink mailing list
> Starlink@lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/starlink


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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[David Lang]

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This is a fallback that will only be if there is no other coverage, and will be 
a poor data rate.

I would expect that the impact to the phone battery would be less than the phone 
continually searching for a tower

Also, SpaceX has pushed back, according to them this isn't observed interference 
with their signals, instead they reconfigured a satellite to the direct-to-phone 
frequencies and were able to detect them

we'll see what the real story is.

On Mon, 3 Jun 2024, Eugene Y Chang via Starlink wrote:

> Date: Mon, 3 Jun 2024 10:47:32 -1000
> From: Eugene Y Chang via Starlink <starlink@lists.bufferbloat.net>
> Reply-To: Eugene Y Chang <eugene.chang@ieee.org>
> To: Frantisek Borsik <frantisek.borsik@gmail.com>
> Cc: Dave Taht via Starlink <starlink@lists.bufferbloat.net>
> Subject: Re: [Starlink] SpaceX/Starlink says it's ready for a fall
>     satellite-to-cell service with T-Mobile
> 
> I found this line in the article very interesting: The larger 2nd generation SpaceX satellites can connect to the majority of T-Mobile’s 4G and 5G phones over its 1900 MHz spectrum.
>
> It is exciting a subscriber does not need to buy a new phone.
> What is the expected impact to the phone’s battery life?
> Any speculations?
>
> Gene
> ----------------------------------------------
> Eugene Chang
> eugene.chang@ieee.org
> o 781-799-0233
>
>
>
>
>> On Jun 3, 2024, at 8:08 AM, Frantisek Borsik via Starlink <starlink@lists.bufferbloat.net> wrote:
>>
>> SpaceX & T-Mobile intend to launch direct-to-device (D2D) satellite servicethis fall
>> An analyst told us that will give them an 18- to 24-month lead over some rivals
>> AT&T & Verizon are still backing AST SpaceMobile as an alternative
>>
>> https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile <https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile>
>>
>> All the best,
>>
>> Frank
>>
>> Frantisek (Frank) Borsik
>>
>>
>>
>> https://www.linkedin.com/in/frantisekborsik <https://www.linkedin.com/in/frantisekborsik>
>> Signal, Telegram, WhatsApp: +421919416714
>>
>> iMessage, mobile: +420775230885
>>
>> Skype: casioa5302ca
>>
>> frantisek.borsik@gmail.com <mailto:frantisek.borsik@gmail.com>_______________________________________________
>> Starlink mailing list
>> Starlink@lists.bufferbloat.net
>> https://lists.bufferbloat.net/listinfo/starlink
>
>

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_______________________________________________
Starlink mailing list
Starlink@lists.bufferbloat.net
https://lists.bufferbloat.net/listinfo/starlink

Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[Eugene Y Chang]

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I expect low data rate because the distance will fall back to a lower coding rate.

I observe a difference in my phone’s batter life between urban and rural usage. I expect the battery life to be significantly reduced with Starlink.
And yes… if the phone isn’t communicating then the battery life isn’t drawn down much…
But users with high screen times will have to change their habits.
— avoid receiving text messages (not under the user’s control)
— don’t receive email pushes
— stop all the social media updates, messages, and likes.
— turn off the apps
— only use the phone for emergencies.

Who are the intended users?

Gene
----------------------------------------------
Eugene Chang
IEEE Life Senior Member
IEEE Communications Society, Computer Society, & Signal Processing Society,
    Hawaii Chapter Chair
IEEE Life Member Affinity Group Hawaii Chair
IEEE Entrepreneurship, Mentor
eugene.chang@ieee.org
m 781-799-0233 (in Honolulu)



> On Jun 3, 2024, at 11:16 AM, David Lang <david@lang.hm> wrote:
> 
> This is a fallback that will only be if there is no other coverage, and will be a poor data rate.
> 
> I would expect that the impact to the phone battery would be less than the phone continually searching for a tower
> 
> Also, SpaceX has pushed back, according to them this isn't observed interference with their signals, instead they reconfigured a satellite to the direct-to-phone frequencies and were able to detect them
> 
> we'll see what the real story is.
> 
> On Mon, 3 Jun 2024, Eugene Y Chang via Starlink wrote:
> 
>> Date: Mon, 3 Jun 2024 10:47:32 -1000
>> From: Eugene Y Chang via Starlink <starlink@lists.bufferbloat.net <mailto:starlink@lists.bufferbloat.net>>
>> Reply-To: Eugene Y Chang <eugene.chang@ieee.org <mailto:eugene.chang@ieee.org>>
>> To: Frantisek Borsik <frantisek.borsik@gmail.com <mailto:frantisek.borsik@gmail.com>>
>> Cc: Dave Taht via Starlink <starlink@lists.bufferbloat.net <mailto:starlink@lists.bufferbloat.net>>
>> Subject: Re: [Starlink] SpaceX/Starlink says it's ready for a fall
>>    satellite-to-cell service with T-Mobile
>> I found this line in the article very interesting: The larger 2nd generation SpaceX satellites can connect to the majority of T-Mobile’s 4G and 5G phones over its 1900 MHz spectrum.
>> 
>> It is exciting a subscriber does not need to buy a new phone.
>> What is the expected impact to the phone’s battery life?
>> Any speculations?
>> 
>> Gene
>> ----------------------------------------------
>> Eugene Chang
>> eugene.chang@ieee.org
>> o 781-799-0233
>> 
>> 
>> 
>> 
>>> On Jun 3, 2024, at 8:08 AM, Frantisek Borsik via Starlink <starlink@lists.bufferbloat.net> wrote:
>>> 
>>> SpaceX & T-Mobile intend to launch direct-to-device (D2D) satellite servicethis fall
>>> An analyst told us that will give them an 18- to 24-month lead over some rivals
>>> AT&T & Verizon are still backing AST SpaceMobile as an alternative
>>> 
>>> https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile <https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile><https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile <https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile>>
>>> 
>>> All the best,
>>> 
>>> Frank
>>> 
>>> Frantisek (Frank) Borsik
>>> 
>>> 
>>> 
>>> https://www.linkedin.com/in/frantisekborsik <https://www.linkedin.com/in/frantisekborsik> <https://www.linkedin.com/in/frantisekborsik <https://www.linkedin.com/in/frantisekborsik>>
>>> Signal, Telegram, WhatsApp: +421919416714
>>> 
>>> iMessage, mobile: +420775230885
>>> 
>>> Skype: casioa5302ca
>>> 
>>> frantisek.borsik@gmail.com <mailto:frantisek.borsik@gmail.com> <mailto:frantisek.borsik@gmail.com <mailto:frantisek.borsik@gmail.com>>_______________________________________________
>>> Starlink mailing list
>>> Starlink@lists.bufferbloat.net <mailto:Starlink@lists.bufferbloat.net>
>>> https://lists.bufferbloat.net/listinfo/starlink <https://lists.bufferbloat.net/listinfo/starlink>
>> 
> _______________________________________________
> Starlink mailing list
> Starlink@lists.bufferbloat.net <mailto:Starlink@lists.bufferbloat.net>
> https://lists.bufferbloat.net/listinfo/starlink <https://lists.bufferbloat.net/listinfo/starlink>

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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[Frantisek Borsik]

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As one of LibreQoS' users noted: "Excellent news for hunting this year.
Bye-bye Iridium"

So hunters, for starters.

All the best,

Frank

Frantisek (Frank) Borsik



https://www.linkedin.com/in/frantisekborsik

Signal, Telegram, WhatsApp: +421919416714

iMessage, mobile: +420775230885

Skype: casioa5302ca

frantisek.borsik@gmail.com

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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[David Lang]

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Eugene Y Chang wrote:

> I expect low data rate because the distance will fall back to a lower coding 
> rate.

I think it's going to be more a matter of very large cells, so many people 
sharing the available bandwidth

> I observe a difference in my phone’s batter life between urban and rural usage. I expect the battery life to be significantly reduced with Starlink.
> And yes… if the phone isn’t communicating then the battery life isn’t drawn down much…

In my experience, a phone that's trying to find a tower uses more power than one 
that has a tower, but is otherwise idle

> But users with high screen times will have to change their habits.
> — avoid receiving text messages (not under the user’s control)
> — don’t receive email pushes
> — stop all the social media updates, messages, and likes.
> — turn off the apps
> — only use the phone for emergencies.
>
> Who are the intended users?

emergancy communication in areas that currently have zero service, primarily 
text messages, then voice, then low bandwidth data.

David Lang

> Gene
> ----------------------------------------------
> Eugene Chang
> IEEE Life Senior Member
> IEEE Communications Society, Computer Society, & Signal Processing Society,
>    Hawaii Chapter Chair
> IEEE Life Member Affinity Group Hawaii Chair
> IEEE Entrepreneurship, Mentor
> eugene.chang@ieee.org
> m 781-799-0233 (in Honolulu)
>
>
>
>> On Jun 3, 2024, at 11:16 AM, David Lang <david@lang.hm> wrote:
>>
>> This is a fallback that will only be if there is no other coverage, and will be a poor data rate.
>>
>> I would expect that the impact to the phone battery would be less than the phone continually searching for a tower
>>
>> Also, SpaceX has pushed back, according to them this isn't observed interference with their signals, instead they reconfigured a satellite to the direct-to-phone frequencies and were able to detect them
>>
>> we'll see what the real story is.
>>
>> On Mon, 3 Jun 2024, Eugene Y Chang via Starlink wrote:
>>
>>> Date: Mon, 3 Jun 2024 10:47:32 -1000
>>> From: Eugene Y Chang via Starlink <starlink@lists.bufferbloat.net <mailto:starlink@lists.bufferbloat.net>>
>>> Reply-To: Eugene Y Chang <eugene.chang@ieee.org <mailto:eugene.chang@ieee.org>>
>>> To: Frantisek Borsik <frantisek.borsik@gmail.com <mailto:frantisek.borsik@gmail.com>>
>>> Cc: Dave Taht via Starlink <starlink@lists.bufferbloat.net <mailto:starlink@lists.bufferbloat.net>>
>>> Subject: Re: [Starlink] SpaceX/Starlink says it's ready for a fall
>>>    satellite-to-cell service with T-Mobile
>>> I found this line in the article very interesting: The larger 2nd generation SpaceX satellites can connect to the majority of T-Mobile’s 4G and 5G phones over its 1900 MHz spectrum.
>>>
>>> It is exciting a subscriber does not need to buy a new phone.
>>> What is the expected impact to the phone’s battery life?
>>> Any speculations?
>>>
>>> Gene
>>> ----------------------------------------------
>>> Eugene Chang
>>> eugene.chang@ieee.org
>>> o 781-799-0233
>>>
>>>
>>>
>>>
>>>> On Jun 3, 2024, at 8:08 AM, Frantisek Borsik via Starlink <starlink@lists.bufferbloat.net> wrote:
>>>>
>>>> SpaceX & T-Mobile intend to launch direct-to-device (D2D) satellite servicethis fall
>>>> An analyst told us that will give them an 18- to 24-month lead over some rivals
>>>> AT&T & Verizon are still backing AST SpaceMobile as an alternative
>>>>
>>>> https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile <https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile><https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile <https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile>>
>>>>
>>>> All the best,
>>>>
>>>> Frank
>>>>
>>>> Frantisek (Frank) Borsik
>>>>
>>>>
>>>>
>>>> https://www.linkedin.com/in/frantisekborsik <https://www.linkedin.com/in/frantisekborsik> <https://www.linkedin.com/in/frantisekborsik <https://www.linkedin.com/in/frantisekborsik>>
>>>> Signal, Telegram, WhatsApp: +421919416714
>>>>
>>>> iMessage, mobile: +420775230885
>>>>
>>>> Skype: casioa5302ca
>>>>
>>>> frantisek.borsik@gmail.com <mailto:frantisek.borsik@gmail.com> <mailto:frantisek.borsik@gmail.com <mailto:frantisek.borsik@gmail.com>>_______________________________________________
>>>> Starlink mailing list
>>>> Starlink@lists.bufferbloat.net <mailto:Starlink@lists.bufferbloat.net>
>>>> https://lists.bufferbloat.net/listinfo/starlink <https://lists.bufferbloat.net/listinfo/starlink>
>>>
>> _______________________________________________
>> Starlink mailing list
>> Starlink@lists.bufferbloat.net <mailto:Starlink@lists.bufferbloat.net>
>> https://lists.bufferbloat.net/listinfo/starlink <https://lists.bufferbloat.net/listinfo/starlink>
>

Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[Eugene Y Chang]

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> On Jun 3, 2024, at 12:41 PM, David Lang <david@lang.hm> wrote:
> 
> Eugene Y Chang wrote:
> 
>> I expect low data rate because the distance will fall back to a lower coding rate.
> 
> I think it's going to be more a matter of very large cells, so many people sharing the available bandwidth
> 
>> I observe a difference in my phone’s batter life between urban and rural usage. I expect the battery life to be significantly reduced with Starlink.
>> And yes… if the phone isn’t communicating then the battery life isn’t drawn down much…
> 
> In my experience, a phone that's trying to find a tower uses more power than one that has a tower, but is otherwise idle

When the phone is searching for a tower, it is transmitting at maximum power.
Then, the phone adjusts the transmit power according to the distance to the tower,
In an urban environment, the distance to the tower is usually less (i.e. smaller cells due to subscriber density).
In a rural environment, there is more distance to the tower, and the phone is transmitting at higher power (i.e., towers are farther apart for larger cells due to fewer subscribers per tower, up to the max tower separation.)
When you are mobile, the power is proportionate to the mean distance to the tower during your operations.



> 
>> But users with high screen times will have to change their habits.
>> — avoid receiving text messages (not under the user’s control)
>> — don’t receive email pushes
>> — stop all the social media updates, messages, and likes.
>> — turn off the apps
>> — only use the phone for emergencies.
>> 
>> Who are the intended users?
> 
> emergancy communication in areas that currently have zero service, primarily text messages, then voice, then low bandwidth data.
> 
> David Lang
> 
>> Gene
>> ----------------------------------------------
>> Eugene Chang
>> IEEE Life Senior Member
>> IEEE Communications Society, Computer Society, & Signal Processing Society,
>>   Hawaii Chapter Chair
>> IEEE Life Member Affinity Group Hawaii Chair
>> IEEE Entrepreneurship, Mentor
>> eugene.chang@ieee.org
>> m 781-799-0233 (in Honolulu)
>> 
>> 
>> 
>>> On Jun 3, 2024, at 11:16 AM, David Lang <david@lang.hm> wrote:
>>> 
>>> This is a fallback that will only be if there is no other coverage, and will be a poor data rate.
>>> 
>>> I would expect that the impact to the phone battery would be less than the phone continually searching for a tower
>>> 
>>> Also, SpaceX has pushed back, according to them this isn't observed interference with their signals, instead they reconfigured a satellite to the direct-to-phone frequencies and were able to detect them
>>> 
>>> we'll see what the real story is.
>>> 
>>> On Mon, 3 Jun 2024, Eugene Y Chang via Starlink wrote:
>>> 
>>>> Date: Mon, 3 Jun 2024 10:47:32 -1000
>>>> From: Eugene Y Chang via Starlink <starlink@lists.bufferbloat.net <mailto:starlink@lists.bufferbloat.net> <mailto:starlink@lists.bufferbloat.net <mailto:starlink@lists.bufferbloat.net>>>
>>>> Reply-To: Eugene Y Chang <eugene.chang@ieee.org <mailto:eugene.chang@ieee.org> <mailto:eugene.chang@ieee.org <mailto:eugene.chang@ieee.org>>>
>>>> To: Frantisek Borsik <frantisek.borsik@gmail.com <mailto:frantisek.borsik@gmail.com> <mailto:frantisek.borsik@gmail.com <mailto:frantisek.borsik@gmail.com>>>
>>>> Cc: Dave Taht via Starlink <starlink@lists.bufferbloat.net <mailto:starlink@lists.bufferbloat.net> <mailto:starlink@lists.bufferbloat.net <mailto:starlink@lists.bufferbloat.net>>>
>>>> Subject: Re: [Starlink] SpaceX/Starlink says it's ready for a fall
>>>>   satellite-to-cell service with T-Mobile
>>>> I found this line in the article very interesting: The larger 2nd generation SpaceX satellites can connect to the majority of T-Mobile’s 4G and 5G phones over its 1900 MHz spectrum.
>>>> 
>>>> It is exciting a subscriber does not need to buy a new phone.
>>>> What is the expected impact to the phone’s battery life?
>>>> Any speculations?
>>>> 
>>>> Gene
>>>> ----------------------------------------------
>>>> Eugene Chang
>>>> eugene.chang@ieee.org <mailto:eugene.chang@ieee.org>
>>>> o 781-799-0233
>>>> 
>>>> 
>>>> 
>>>> 
>>>>> On Jun 3, 2024, at 8:08 AM, Frantisek Borsik via Starlink <starlink@lists.bufferbloat.net <mailto:starlink@lists.bufferbloat.net>> wrote:
>>>>> 
>>>>> SpaceX & T-Mobile intend to launch direct-to-device (D2D) satellite servicethis fall
>>>>> An analyst told us that will give them an 18- to 24-month lead over some rivals
>>>>> AT&T & Verizon are still backing AST SpaceMobile as an alternative
>>>>> 
>>>>> https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile <https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile><https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile <https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile>><https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile <https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile><https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile <https://www.fierce-network.com/wireless/space-x-says-its-ready-fall-direct-satellite-cell-service-t-mobile>>>
>>>>> 
>>>>> All the best,
>>>>> 
>>>>> Frank
>>>>> 
>>>>> Frantisek (Frank) Borsik
>>>>> 
>>>>> 
>>>>> 
>>>>> https://www.linkedin.com/in/frantisekborsik <https://www.linkedin.com/in/frantisekborsik> <https://www.linkedin.com/in/frantisekborsik <https://www.linkedin.com/in/frantisekborsik>> <https://www.linkedin.com/in/frantisekborsik <https://www.linkedin.com/in/frantisekborsik> <https://www.linkedin.com/in/frantisekborsik <https://www.linkedin.com/in/frantisekborsik>>>
>>>>> Signal, Telegram, WhatsApp: +421919416714
>>>>> 
>>>>> iMessage, mobile: +420775230885
>>>>> 
>>>>> Skype: casioa5302ca
>>>>> 
>>>>> frantisek.borsik@gmail.com <mailto:frantisek.borsik@gmail.com> <mailto:frantisek.borsik@gmail.com <mailto:frantisek.borsik@gmail.com>> <mailto:frantisek.borsik@gmail.com <mailto:frantisek.borsik@gmail.com><mailto:frantisek.borsik@gmail.com <mailto:frantisek.borsik@gmail.com>>>_______________________________________________
>>>>> Starlink mailing list
>>>>> Starlink@lists.bufferbloat.net <mailto:Starlink@lists.bufferbloat.net> <mailto:Starlink@lists.bufferbloat.net <mailto:Starlink@lists.bufferbloat.net>>
>>>>> https://lists.bufferbloat.net/listinfo/starlink <https://lists.bufferbloat.net/listinfo/starlink> <https://lists.bufferbloat.net/listinfo/starlink <https://lists.bufferbloat.net/listinfo/starlink>>
>>>> 
>>> _______________________________________________
>>> Starlink mailing list
>>> Starlink@lists.bufferbloat.net <mailto:Starlink@lists.bufferbloat.net> <mailto:Starlink@lists.bufferbloat.net <mailto:Starlink@lists.bufferbloat.net>>
>>> https://lists.bufferbloat.net/listinfo/starlink <https://lists.bufferbloat.net/listinfo/starlink> <https://lists.bufferbloat.net/listinfo/starlink <https://lists.bufferbloat.net/listinfo/starlink>>


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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[David Lang]

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Eugene Y Chang wrote:

>> On Jun 3, 2024, at 12:41 PM, David Lang <david@lang.hm> wrote:
>>
>> Eugene Y Chang wrote:
>>
>>> I expect low data rate because the distance will fall back to a lower coding rate.
>>
>> I think it's going to be more a matter of very large cells, so many people sharing the available bandwidth
>>
>>> I observe a difference in my phone’s batter life between urban and rural usage. I expect the battery life to be significantly reduced with Starlink.
>>> And yes… if the phone isn’t communicating then the battery life isn’t drawn down much…
>>
>> In my experience, a phone that's trying to find a tower uses more power than one that has a tower, but is otherwise idle
>
> When the phone is searching for a tower, it is transmitting at maximum power.
> Then, the phone adjusts the transmit power according to the distance to the tower,
> In an urban environment, the distance to the tower is usually less (i.e. smaller cells due to subscriber density).
> In a rural environment, there is more distance to the tower, and the phone is transmitting at higher power (i.e., towers are farther apart for larger cells due to fewer subscribers per tower, up to the max tower separation.)
> When you are mobile, the power is proportionate to the mean distance to the tower during your operations.

and for direct-to-satellite, it's going to be a max power situation, similar to 
rural.

But when a phone is not connected, how frequent are it's searches for towers 
(especially if it has multiple bands to check) compared to the 'keepalive' pings 
when it is connected? if it's doing more transmissions for it's search and 
attempts to connect than it does while connected and just confirming the 
connection, that could eat more power.

David Lang

Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[Frantisek Borsik]

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Some additional reading from William Webb:

https://www.linkedin.com/pulse/satellite-direct-device-workable-william-webb-sonke/?trackingId=Sjha4DY8SqONFA9g%2Bb5b%2Bw%3D%3D

All the best,

Frank

Frantisek (Frank) Borsik



https://www.linkedin.com/in/frantisekborsik

Signal, Telegram, WhatsApp: +421919416714

iMessage, mobile: +420775230885

Skype: casioa5302ca

frantisek.borsik@gmail.com


On Tue, Jun 4, 2024 at 2:54 AM David Lang <david@lang.hm> wrote:

> Eugene Y Chang wrote:
>
> >> On Jun 3, 2024, at 12:41 PM, David Lang <david@lang.hm> wrote:
> >>
> >> Eugene Y Chang wrote:
> >>
> >>> I expect low data rate because the distance will fall back to a lower
> coding rate.
> >>
> >> I think it's going to be more a matter of very large cells, so many
> people sharing the available bandwidth
> >>
> >>> I observe a difference in my phone’s batter life between urban and
> rural usage. I expect the battery life to be significantly reduced with
> Starlink.
> >>> And yes… if the phone isn’t communicating then the battery life isn’t
> drawn down much…
> >>
> >> In my experience, a phone that's trying to find a tower uses more power
> than one that has a tower, but is otherwise idle
> >
> > When the phone is searching for a tower, it is transmitting at maximum
> power.
> > Then, the phone adjusts the transmit power according to the distance to
> the tower,
> > In an urban environment, the distance to the tower is usually less (i.e.
> smaller cells due to subscriber density).
> > In a rural environment, there is more distance to the tower, and the
> phone is transmitting at higher power (i.e., towers are farther apart for
> larger cells due to fewer subscribers per tower, up to the max tower
> separation.)
> > When you are mobile, the power is proportionate to the mean distance to
> the tower during your operations.
>
> and for direct-to-satellite, it's going to be a max power situation,
> similar to
> rural.
>
> But when a phone is not connected, how frequent are it's searches for
> towers
> (especially if it has multiple bands to check) compared to the 'keepalive'
> pings
> when it is connected? if it's doing more transmissions for it's search and
> attempts to connect than it does while connected and just confirming the
> connection, that could eat more power.
>
> David Lang

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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[Alexandre Petrescu]

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does it say whether it is text only, data only, or everything including 
voice?

Le 04/06/2024 à 13:20, Frantisek Borsik via Starlink a écrit :
> Some additional reading from William Webb:
>
> https://www.linkedin.com/pulse/satellite-direct-device-workable-william-webb-sonke/?trackingId=Sjha4DY8SqONFA9g%2Bb5b%2Bw%3D%3D
>
> All the best,
>
> Frank
>
> Frantisek (Frank) Borsik
>
> https://www.linkedin.com/in/frantisekborsik
>
> Signal, Telegram, WhatsApp: +421919416714
>
> iMessage, mobile: +420775230885
>
> Skype: casioa5302ca
>
> frantisek.borsik@gmail.com
>
>
>
> On Tue, Jun 4, 2024 at 2:54 AM David Lang <david@lang.hm> wrote:
>
>     Eugene Y Chang wrote:
>
>     >> On Jun 3, 2024, at 12:41 PM, David Lang <david@lang.hm> wrote:
>     >>
>     >> Eugene Y Chang wrote:
>     >>
>     >>> I expect low data rate because the distance will fall back to
>     a lower coding rate.
>     >>
>     >> I think it's going to be more a matter of very large cells, so
>     many people sharing the available bandwidth
>     >>
>     >>> I observe a difference in my phone’s batter life between urban
>     and rural usage. I expect the battery life to be significantly
>     reduced with Starlink.
>     >>> And yes… if the phone isn’t communicating then the battery
>     life isn’t drawn down much…
>     >>
>     >> In my experience, a phone that's trying to find a tower uses
>     more power than one that has a tower, but is otherwise idle
>     >
>     > When the phone is searching for a tower, it is transmitting at
>     maximum power.
>     > Then, the phone adjusts the transmit power according to the
>     distance to the tower,
>     > In an urban environment, the distance to the tower is usually
>     less (i.e. smaller cells due to subscriber density).
>     > In a rural environment, there is more distance to the tower, and
>     the phone is transmitting at higher power (i.e., towers are
>     farther apart for larger cells due to fewer subscribers per tower,
>     up to the max tower separation.)
>     > When you are mobile, the power is proportionate to the mean
>     distance to the tower during your operations.
>
>     and for direct-to-satellite, it's going to be a max power
>     situation, similar to
>     rural.
>
>     But when a phone is not connected, how frequent are it's searches
>     for towers
>     (especially if it has multiple bands to check) compared to the
>     'keepalive' pings
>     when it is connected? if it's doing more transmissions for it's
>     search and
>     attempts to connect than it does while connected and just
>     confirming the
>     connection, that could eat more power.
>
>     David Lang
>
>
> _______________________________________________
> Starlink mailing list
> Starlink@lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/starlink

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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[Frantisek Borsik]

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The whole article is worth reading, but tl;dr;

"The promise of D2D is alluring – that we can be connected wherever we are
– no more not-spots and the certainty of always being able to contact
others. But the reality is some way from this. The only existing D2D
service is Apple’s iPhone emergency communications which offers messaging
to the emergency services and vehicle assistance in 16 countries. This does
not appear to be a service Apple thinks it can charge for at present.

Those offerings that have the greatest potential for ubiquity are within
the MSS spectrum. But here bandwidths are too constrained to deliver full
service capabilities. Other MSS operators such as Iridium have struggled to
put together a commercial D2D proposition (although their core business
remains strong).

The other approach of using MS spectrum has strong backers in the form of
SpaceX and T-Mobile as well as multiple promising start-ups. But it is
beset with challenges of avoiding interference with existing terrestrial
use, overcoming restrictions in border areas, ensuring compliance with
hundreds of regulators, of which only one has a defined policy towards D2D
at present, doing deals with hundreds of operators and managing other
regulatory hurdles. Only US-based coverage looks likely any time soon and
the true extent of that remains unclear.

With limited offers, the consumer interest will be less. Quite how much
less is very unclear, but it is clear that the business case will be
challenging. Most consumers appear to have limited interest in paying more
per month for better coverage.

In summary, D2D’s alluring promise of ubiquitous fully-featured global
connectivity is not likely to be realised any time soon, if ever, but a
reduced service level in a few countries may be sufficient to justify
launching suitable satellites."


All the best,

Frank

Frantisek (Frank) Borsik



https://www.linkedin.com/in/frantisekborsik

Signal, Telegram, WhatsApp: +421919416714

iMessage, mobile: +420775230885

Skype: casioa5302ca

frantisek.borsik@gmail.com


On Tue, Jun 4, 2024 at 1:43 PM Alexandre Petrescu via Starlink <
starlink@lists.bufferbloat.net> wrote:

> does it say whether it is text only, data only, or everything including
> voice?
> Le 04/06/2024 à 13:20, Frantisek Borsik via Starlink a écrit :
>
> Some additional reading from William Webb:
>
>
> https://www.linkedin.com/pulse/satellite-direct-device-workable-william-webb-sonke/?trackingId=Sjha4DY8SqONFA9g%2Bb5b%2Bw%3D%3D
>
> All the best,
>
> Frank
>
> Frantisek (Frank) Borsik
>
>
>
> https://www.linkedin.com/in/frantisekborsik
>
> Signal, Telegram, WhatsApp: +421919416714
>
> iMessage, mobile: +420775230885
>
> Skype: casioa5302ca
>
> frantisek.borsik@gmail.com
>
>
> On Tue, Jun 4, 2024 at 2:54 AM David Lang <david@lang.hm> wrote:
>
>> Eugene Y Chang wrote:
>>
>> >> On Jun 3, 2024, at 12:41 PM, David Lang <david@lang.hm> wrote:
>> >>
>> >> Eugene Y Chang wrote:
>> >>
>> >>> I expect low data rate because the distance will fall back to a lower
>> coding rate.
>> >>
>> >> I think it's going to be more a matter of very large cells, so many
>> people sharing the available bandwidth
>> >>
>> >>> I observe a difference in my phone’s batter life between urban and
>> rural usage. I expect the battery life to be significantly reduced with
>> Starlink.
>> >>> And yes… if the phone isn’t communicating then the battery life isn’t
>> drawn down much…
>> >>
>> >> In my experience, a phone that's trying to find a tower uses more
>> power than one that has a tower, but is otherwise idle
>> >
>> > When the phone is searching for a tower, it is transmitting at maximum
>> power.
>> > Then, the phone adjusts the transmit power according to the distance to
>> the tower,
>> > In an urban environment, the distance to the tower is usually less
>> (i.e. smaller cells due to subscriber density).
>> > In a rural environment, there is more distance to the tower, and the
>> phone is transmitting at higher power (i.e., towers are farther apart for
>> larger cells due to fewer subscribers per tower, up to the max tower
>> separation.)
>> > When you are mobile, the power is proportionate to the mean distance to
>> the tower during your operations.
>>
>> and for direct-to-satellite, it's going to be a max power situation,
>> similar to
>> rural.
>>
>> But when a phone is not connected, how frequent are it's searches for
>> towers
>> (especially if it has multiple bands to check) compared to the
>> 'keepalive' pings
>> when it is connected? if it's doing more transmissions for it's search
>> and
>> attempts to connect than it does while connected and just confirming the
>> connection, that could eat more power.
>>
>> David Lang
>
>
> _______________________________________________
> Starlink mailing listStarlink@lists.bufferbloat.nethttps://lists.bufferbloat.net/listinfo/starlink
>
> _______________________________________________
> Starlink mailing list
> Starlink@lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/starlink
>

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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[Ulrich Speidel]

[-- Attachment #1: Type: text/plain, Size: 7861 bytes --]

Yep. Getting 17 Mb/s from a single satellite to a single cellphone is 
one thing. But serving multiple/many users is a different story. Because 
if that's what you want to do, you only have a few options:

  * Share the beam capacity between them - everyone gets a slice.
  * Have more (and smaller) beams, so the same frequency can be used in
    parallel for multiple users. This requires more and larger antennas
    on the satellite.
  * Up EIRP to get more power down to Earth. This requires larger
    antennas on the satellite.

As a general rule, when it comes to having sharp beams, both antenna 
gain (for a fixed size antenna) and path loss between spacecraft and 
ground increase with the square of the carrier frequency. Antenna gain 
helps us to get a nice signal at the receiver, path loss works against 
us in this sense. We have one antenna at each end - and gains multiply - 
so that gives us a term that's proportional to frequency to the power of 
4. Divide that by the frequency to the power of 2 from your path loss 
and you end up with a signal at the receiver that is proportional to the 
frequency squared. What does this mean in practice? Well, it means it's 
easier to project sharp beams if your carrier frequency is higher.

Now for the D2D phone spectrum that SpaceX are using, we're between 1 
and 2 GHz. The Ku and Ka spectrum band that Starlink is otherwise 
licensed for is between 10 and 30 GHz. That's very much back foot 
territory for the D2D beams compared to the Ku and Ka ones.

So low bit rate D2D services with few users are a much easier target to 
hit than 4G data rates for the rural populus at large.

On 4/06/2024 11:54 pm, Frantisek Borsik via Starlink wrote:
> The whole article is worth reading, but tl;dr;
>
> "The promise of D2D is alluring – that we can be connected wherever we 
> are – no more not-spots and the certainty of always being able to 
> contact others. But the reality is some way from this. The only 
> existing D2D service is Apple’s iPhone emergency communications which 
> offers messaging to the emergency services and vehicle assistance in 
> 16 countries. This does not appear to be a service Apple thinks it can 
> charge for at present.
>
> Those offerings that have the greatest potential for ubiquity are 
> within the MSS spectrum. But here bandwidths are too constrained to 
> deliver full service capabilities. Other MSS operators such as Iridium 
> have struggled to put together a commercial D2D proposition (although 
> their core business remains strong).
>
> The other approach of using MS spectrum has strong backers in the form 
> of SpaceX and T-Mobile as well as multiple promising start-ups. But it 
> is beset with challenges of avoiding interference with existing 
> terrestrial use, overcoming restrictions in border areas, ensuring 
> compliance with hundreds of regulators, of which only one has a 
> defined policy towards D2D at present, doing deals with hundreds of 
> operators and managing other regulatory hurdles. Only US-based 
> coverage looks likely any time soon and the true extent of that 
> remains unclear.
>
> With limited offers, the consumer interest will be less. Quite how 
> much less is very unclear, but it is clear that the business case will 
> be challenging. Most consumers appear to have limited interest in 
> paying more per month for better coverage.
>
> In summary, D2D’s alluring promise of ubiquitous fully-featured global 
> connectivity is not likely to be realised any time soon, if ever, but 
> a reduced service level in a few countries may be sufficient to 
> justify launching suitable satellites."
>
>
>
> All the best,
>
> Frank
>
> Frantisek (Frank) Borsik
>
> https://www.linkedin.com/in/frantisekborsik
>
> Signal, Telegram, WhatsApp: +421919416714
>
> iMessage, mobile: +420775230885
>
> Skype: casioa5302ca
>
> frantisek.borsik@gmail.com
>
>
>
> On Tue, Jun 4, 2024 at 1:43 PM Alexandre Petrescu via Starlink 
> <starlink@lists.bufferbloat.net> wrote:
>
>     does it say whether it is text only, data only, or everything
>     including voice?
>
>     Le 04/06/2024 à 13:20, Frantisek Borsik via Starlink a écrit :
>>     Some additional reading from William Webb:
>>
>>     https://www.linkedin.com/pulse/satellite-direct-device-workable-william-webb-sonke/?trackingId=Sjha4DY8SqONFA9g%2Bb5b%2Bw%3D%3D
>>
>>     All the best,
>>
>>     Frank
>>
>>     Frantisek (Frank) Borsik
>>
>>     https://www.linkedin.com/in/frantisekborsik
>>
>>     Signal, Telegram, WhatsApp: +421919416714
>>
>>     iMessage, mobile: +420775230885
>>
>>     Skype: casioa5302ca
>>
>>     frantisek.borsik@gmail.com
>>
>>
>>
>>     On Tue, Jun 4, 2024 at 2:54 AM David Lang <david@lang.hm> wrote:
>>
>>         Eugene Y Chang wrote:
>>
>>         >> On Jun 3, 2024, at 12:41 PM, David Lang <david@lang.hm> wrote:
>>         >>
>>         >> Eugene Y Chang wrote:
>>         >>
>>         >>> I expect low data rate because the distance will fall
>>         back to a lower coding rate.
>>         >>
>>         >> I think it's going to be more a matter of very large
>>         cells, so many people sharing the available bandwidth
>>         >>
>>         >>> I observe a difference in my phone’s batter life between
>>         urban and rural usage. I expect the battery life to be
>>         significantly reduced with Starlink.
>>         >>> And yes… if the phone isn’t communicating then the
>>         battery life isn’t drawn down much…
>>         >>
>>         >> In my experience, a phone that's trying to find a tower
>>         uses more power than one that has a tower, but is otherwise idle
>>         >
>>         > When the phone is searching for a tower, it is transmitting
>>         at maximum power.
>>         > Then, the phone adjusts the transmit power according to the
>>         distance to the tower,
>>         > In an urban environment, the distance to the tower is
>>         usually less (i.e. smaller cells due to subscriber density).
>>         > In a rural environment, there is more distance to the
>>         tower, and the phone is transmitting at higher power (i.e.,
>>         towers are farther apart for larger cells due to fewer
>>         subscribers per tower, up to the max tower separation.)
>>         > When you are mobile, the power is proportionate to the mean
>>         distance to the tower during your operations.
>>
>>         and for direct-to-satellite, it's going to be a max power
>>         situation, similar to
>>         rural.
>>
>>         But when a phone is not connected, how frequent are it's
>>         searches for towers
>>         (especially if it has multiple bands to check) compared to
>>         the 'keepalive' pings
>>         when it is connected? if it's doing more transmissions for
>>         it's search and
>>         attempts to connect than it does while connected and just
>>         confirming the
>>         connection, that could eat more power.
>>
>>         David Lang
>>
>>
>>     _______________________________________________
>>     Starlink mailing list
>>     Starlink@lists.bufferbloat.net
>>     https://lists.bufferbloat.net/listinfo/starlink
>     _______________________________________________
>     Starlink mailing list
>     Starlink@lists.bufferbloat.net
>     https://lists.bufferbloat.net/listinfo/starlink
>
>
> _______________________________________________
> Starlink mailing list
> Starlink@lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/starlink

-- 
****************************************************************
Dr. Ulrich Speidel

School of Computer Science

Room 303S.594 (City Campus)
Ph: (+64-9)-373-7599 ext. 85282

The University of Auckland
ulrich@cs.auckland.ac.nz
http://www.cs.auckland.ac.nz/~ulrich/
****************************************************************

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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[David Lang]

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And we have statements that the direct to satellite cell service SpaceX is 
rolling out will have very large cells, even with the large antennas on the 
satellites.

I seem to remember something about cells beitn 70 miles or so large.

so it really is going to be low bandwidth for emergancy use or VERY rural uses

David Lang

Ulrich Speidel wrote:

> Yep. Getting 17 Mb/s from a single satellite to a single cellphone is one 
> thing. But serving multiple/many users is a different story. Because if 
> that's what you want to do, you only have a few options:
>
> * Share the beam capacity between them - everyone gets a slice.
> * Have more (and smaller) beams, so the same frequency can be used in
>   parallel for multiple users. This requires more and larger antennas
>   on the satellite.
> * Up EIRP to get more power down to Earth. This requires larger
>   antennas on the satellite.
>
> As a general rule, when it comes to having sharp beams, both antenna gain 
> (for a fixed size antenna) and path loss between spacecraft and ground 
> increase with the square of the carrier frequency. Antenna gain helps us to 
> get a nice signal at the receiver, path loss works against us in this sense. 
> We have one antenna at each end - and gains multiply - so that gives us a 
> term that's proportional to frequency to the power of 4. Divide that by the 
> frequency to the power of 2 from your path loss and you end up with a signal 
> at the receiver that is proportional to the frequency squared. What does this 
> mean in practice? Well, it means it's easier to project sharp beams if your 
> carrier frequency is higher.
>
> Now for the D2D phone spectrum that SpaceX are using, we're between 1 and 2 
> GHz. The Ku and Ka spectrum band that Starlink is otherwise licensed for is 
> between 10 and 30 GHz. That's very much back foot territory for the D2D beams 
> compared to the Ku and Ka ones.
>
> So low bit rate D2D services with few users are a much easier target to hit 
> than 4G data rates for the rural populus at large.
>
> On 4/06/2024 11:54 pm, Frantisek Borsik via Starlink wrote:
>> The whole article is worth reading, but tl;dr;
>> 
>> "The promise of D2D is alluring – that we can be connected wherever we are 
>> – no more not-spots and the certainty of always being able to contact 
>> others. But the reality is some way from this. The only existing D2D 
>> service is Apple’s iPhone emergency communications which offers messaging 
>> to the emergency services and vehicle assistance in 16 countries. This does 
>> not appear to be a service Apple thinks it can charge for at present.
>> 
>> Those offerings that have the greatest potential for ubiquity are within 
>> the MSS spectrum. But here bandwidths are too constrained to deliver full 
>> service capabilities. Other MSS operators such as Iridium have struggled to 
>> put together a commercial D2D proposition (although their core business 
>> remains strong).
>> 
>> The other approach of using MS spectrum has strong backers in the form of 
>> SpaceX and T-Mobile as well as multiple promising start-ups. But it is 
>> beset with challenges of avoiding interference with existing terrestrial 
>> use, overcoming restrictions in border areas, ensuring compliance with 
>> hundreds of regulators, of which only one has a defined policy towards D2D 
>> at present, doing deals with hundreds of operators and managing other 
>> regulatory hurdles. Only US-based coverage looks likely any time soon and 
>> the true extent of that remains unclear.
>> 
>> With limited offers, the consumer interest will be less. Quite how much 
>> less is very unclear, but it is clear that the business case will be 
>> challenging. Most consumers appear to have limited interest in paying more 
>> per month for better coverage.
>> 
>> In summary, D2D’s alluring promise of ubiquitous fully-featured global 
>> connectivity is not likely to be realised any time soon, if ever, but a 
>> reduced service level in a few countries may be sufficient to justify 
>> launching suitable satellites."
>> 
>> 
>> 
>> All the best,
>> 
>> Frank
>> 
>> Frantisek (Frank) Borsik
>> 
>> https://www.linkedin.com/in/frantisekborsik
>> 
>> Signal, Telegram, WhatsApp: +421919416714
>> 
>> iMessage, mobile: +420775230885
>> 
>> Skype: casioa5302ca
>> 
>> frantisek.borsik@gmail.com
>> 
>> 
>> 
>> On Tue, Jun 4, 2024 at 1:43 PM Alexandre Petrescu via Starlink 
>> <starlink@lists.bufferbloat.net> wrote:
>>
>>     does it say whether it is text only, data only, or everything
>>     including voice?
>>
>>     Le 04/06/2024 à 13:20, Frantisek Borsik via Starlink a écrit :
>>>     Some additional reading from William Webb:
>>>
>>>     https://www.linkedin.com/pulse/satellite-direct-device-workable-william-webb-sonke/?trackingId=Sjha4DY8SqONFA9g%2Bb5b%2Bw%3D%3D
>>>
>>>     All the best,
>>>
>>>     Frank
>>>
>>>     Frantisek (Frank) Borsik
>>>
>>>     https://www.linkedin.com/in/frantisekborsik
>>>
>>>     Signal, Telegram, WhatsApp: +421919416714
>>>
>>>     iMessage, mobile: +420775230885
>>>
>>>     Skype: casioa5302ca
>>>
>>>     frantisek.borsik@gmail.com
>>> 
>>> 
>>>
>>>     On Tue, Jun 4, 2024 at 2:54 AM David Lang <david@lang.hm> wrote:
>>>
>>>         Eugene Y Chang wrote:
>>>
>>>         >> On Jun 3, 2024, at 12:41 PM, David Lang <david@lang.hm> wrote:
>>>         >>
>>>         >> Eugene Y Chang wrote:
>>>         >>
>>>         >>> I expect low data rate because the distance will fall
>>>         back to a lower coding rate.
>>>         >>
>>>         >> I think it's going to be more a matter of very large
>>>         cells, so many people sharing the available bandwidth
>>>         >>
>>>         >>> I observe a difference in my phone’s batter life between
>>>         urban and rural usage. I expect the battery life to be
>>>         significantly reduced with Starlink.
>>>         >>> And yes… if the phone isn’t communicating then the
>>>         battery life isn’t drawn down much…
>>>         >>
>>>         >> In my experience, a phone that's trying to find a tower
>>>         uses more power than one that has a tower, but is otherwise idle
>>>         >
>>>         > When the phone is searching for a tower, it is transmitting
>>>         at maximum power.
>>>         > Then, the phone adjusts the transmit power according to the
>>>         distance to the tower,
>>>         > In an urban environment, the distance to the tower is
>>>         usually less (i.e. smaller cells due to subscriber density).
>>>         > In a rural environment, there is more distance to the
>>>         tower, and the phone is transmitting at higher power (i.e.,
>>>         towers are farther apart for larger cells due to fewer
>>>         subscribers per tower, up to the max tower separation.)
>>>         > When you are mobile, the power is proportionate to the mean
>>>         distance to the tower during your operations.
>>>
>>>         and for direct-to-satellite, it's going to be a max power
>>>         situation, similar to
>>>         rural.
>>>
>>>         But when a phone is not connected, how frequent are it's
>>>         searches for towers
>>>         (especially if it has multiple bands to check) compared to
>>>         the 'keepalive' pings
>>>         when it is connected? if it's doing more transmissions for
>>>         it's search and
>>>         attempts to connect than it does while connected and just
>>>         confirming the
>>>         connection, that could eat more power.
>>>
>>>         David Lang
>>> 
>>>
>>>     _______________________________________________
>>>     Starlink mailing list
>>>     Starlink@lists.bufferbloat.net
>>>     https://lists.bufferbloat.net/listinfo/starlink
>>     _______________________________________________
>>     Starlink mailing list
>>     Starlink@lists.bufferbloat.net
>>     https://lists.bufferbloat.net/listinfo/starlink
>> 
>> 
>> _______________________________________________
>> Starlink mailing list
>> Starlink@lists.bufferbloat.net
>> https://lists.bufferbloat.net/listinfo/starlink
>
>

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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[Eugene Y Chang]

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> so it really is going to be low bandwidth for emergancy use or VERY rural uses


Or to drive (unrealistic) consumer demand …..

Gene
----------------------------------------------
Eugene Chang
eugene.chang@ieee.org






> On Jun 4, 2024, at 8:10 AM, David Lang via Starlink <starlink@lists.bufferbloat.net> wrote:
> 
> And we have statements that the direct to satellite cell service SpaceX is rolling out will have very large cells, even with the large antennas on the satellites.
> 
> I seem to remember something about cells beitn 70 miles or so large.
> 
> so it really is going to be low bandwidth for emergancy use or VERY rural uses
> 
> David Lang
> 
> Ulrich Speidel wrote:
> 
>> Yep. Getting 17 Mb/s from a single satellite to a single cellphone is one thing. But serving multiple/many users is a different story. Because if that's what you want to do, you only have a few options:
>> 
>> * Share the beam capacity between them - everyone gets a slice.
>> * Have more (and smaller) beams, so the same frequency can be used in
>>  parallel for multiple users. This requires more and larger antennas
>>  on the satellite.
>> * Up EIRP to get more power down to Earth. This requires larger
>>  antennas on the satellite.
>> 
>> As a general rule, when it comes to having sharp beams, both antenna gain (for a fixed size antenna) and path loss between spacecraft and ground increase with the square of the carrier frequency. Antenna gain helps us to get a nice signal at the receiver, path loss works against us in this sense. We have one antenna at each end - and gains multiply - so that gives us a term that's proportional to frequency to the power of 4. Divide that by the frequency to the power of 2 from your path loss and you end up with a signal at the receiver that is proportional to the frequency squared. What does this mean in practice? Well, it means it's easier to project sharp beams if your carrier frequency is higher.
>> 
>> Now for the D2D phone spectrum that SpaceX are using, we're between 1 and 2 GHz. The Ku and Ka spectrum band that Starlink is otherwise licensed for is between 10 and 30 GHz. That's very much back foot territory for the D2D beams compared to the Ku and Ka ones.
>> 
>> So low bit rate D2D services with few users are a much easier target to hit than 4G data rates for the rural populus at large.
>> 
>> On 4/06/2024 11:54 pm, Frantisek Borsik via Starlink wrote:
>>> The whole article is worth reading, but tl;dr;
>>> "The promise of D2D is alluring – that we can be connected wherever we are – no more not-spots and the certainty of always being able to contact others. But the reality is some way from this. The only existing D2D service is Apple’s iPhone emergency communications which offers messaging to the emergency services and vehicle assistance in 16 countries. This does not appear to be a service Apple thinks it can charge for at present.
>>> Those offerings that have the greatest potential for ubiquity are within the MSS spectrum. But here bandwidths are too constrained to deliver full service capabilities. Other MSS operators such as Iridium have struggled to put together a commercial D2D proposition (although their core business remains strong).
>>> The other approach of using MS spectrum has strong backers in the form of SpaceX and T-Mobile as well as multiple promising start-ups. But it is beset with challenges of avoiding interference with existing terrestrial use, overcoming restrictions in border areas, ensuring compliance with hundreds of regulators, of which only one has a defined policy towards D2D at present, doing deals with hundreds of operators and managing other regulatory hurdles. Only US-based coverage looks likely any time soon and the true extent of that remains unclear.
>>> With limited offers, the consumer interest will be less. Quite how much less is very unclear, but it is clear that the business case will be challenging. Most consumers appear to have limited interest in paying more per month for better coverage.
>>> In summary, D2D’s alluring promise of ubiquitous fully-featured global connectivity is not likely to be realised any time soon, if ever, but a reduced service level in a few countries may be sufficient to justify launching suitable satellites."
>>> All the best,
>>> Frank
>>> Frantisek (Frank) Borsik
>>> https://www.linkedin.com/in/frantisekborsik
>>> Signal, Telegram, WhatsApp: +421919416714
>>> iMessage, mobile: +420775230885
>>> Skype: casioa5302ca
>>> frantisek.borsik@gmail.com
>>> On Tue, Jun 4, 2024 at 1:43 PM Alexandre Petrescu via Starlink <starlink@lists.bufferbloat.net> wrote:
>>> 
>>>    does it say whether it is text only, data only, or everything
>>>    including voice?
>>> 
>>>    Le 04/06/2024 à 13:20, Frantisek Borsik via Starlink a écrit :
>>>>    Some additional reading from William Webb:
>>>> 
>>>>    https://www.linkedin.com/pulse/satellite-direct-device-workable-william-webb-sonke/?trackingId=Sjha4DY8SqONFA9g%2Bb5b%2Bw%3D%3D
>>>> 
>>>>    All the best,
>>>> 
>>>>    Frank
>>>> 
>>>>    Frantisek (Frank) Borsik
>>>> 
>>>>    https://www.linkedin.com/in/frantisekborsik
>>>> 
>>>>    Signal, Telegram, WhatsApp: +421919416714
>>>> 
>>>>    iMessage, mobile: +420775230885
>>>> 
>>>>    Skype: casioa5302ca
>>>> 
>>>>    frantisek.borsik@gmail.com
>>>> 
>>>>    On Tue, Jun 4, 2024 at 2:54 AM David Lang <david@lang.hm> wrote:
>>>> 
>>>>        Eugene Y Chang wrote:
>>>> 
>>>>        >> On Jun 3, 2024, at 12:41 PM, David Lang <david@lang.hm> wrote:
>>>>        >>
>>>>        >> Eugene Y Chang wrote:
>>>>        >>
>>>>        >>> I expect low data rate because the distance will fall
>>>>        back to a lower coding rate.
>>>>        >>
>>>>        >> I think it's going to be more a matter of very large
>>>>        cells, so many people sharing the available bandwidth
>>>>        >>
>>>>        >>> I observe a difference in my phone’s batter life between
>>>>        urban and rural usage. I expect the battery life to be
>>>>        significantly reduced with Starlink.
>>>>        >>> And yes… if the phone isn’t communicating then the
>>>>        battery life isn’t drawn down much…
>>>>        >>
>>>>        >> In my experience, a phone that's trying to find a tower
>>>>        uses more power than one that has a tower, but is otherwise idle
>>>>        >
>>>>        > When the phone is searching for a tower, it is transmitting
>>>>        at maximum power.
>>>>        > Then, the phone adjusts the transmit power according to the
>>>>        distance to the tower,
>>>>        > In an urban environment, the distance to the tower is
>>>>        usually less (i.e. smaller cells due to subscriber density).
>>>>        > In a rural environment, there is more distance to the
>>>>        tower, and the phone is transmitting at higher power (i.e.,
>>>>        towers are farther apart for larger cells due to fewer
>>>>        subscribers per tower, up to the max tower separation.)
>>>>        > When you are mobile, the power is proportionate to the mean
>>>>        distance to the tower during your operations.
>>>> 
>>>>        and for direct-to-satellite, it's going to be a max power
>>>>        situation, similar to
>>>>        rural.
>>>> 
>>>>        But when a phone is not connected, how frequent are it's
>>>>        searches for towers
>>>>        (especially if it has multiple bands to check) compared to
>>>>        the 'keepalive' pings
>>>>        when it is connected? if it's doing more transmissions for
>>>>        it's search and
>>>>        attempts to connect than it does while connected and just
>>>>        confirming the
>>>>        connection, that could eat more power.
>>>> 
>>>>        David Lang
>>>> 
>>>>    _______________________________________________
>>>>    Starlink mailing list
>>>>    Starlink@lists.bufferbloat.net
>>>>    https://lists.bufferbloat.net/listinfo/starlink
>>>    _______________________________________________
>>>    Starlink mailing list
>>>    Starlink@lists.bufferbloat.net
>>>    https://lists.bufferbloat.net/listinfo/starlink
>>> _______________________________________________
>>> Starlink mailing list
>>> Starlink@lists.bufferbloat.net
>>> https://lists.bufferbloat.net/listinfo/starlink
>> 
> _______________________________________________
> Starlink mailing list
> Starlink@lists.bufferbloat.net <mailto:Starlink@lists.bufferbloat.net>
> https://lists.bufferbloat.net/listinfo/starlink <https://lists.bufferbloat.net/listinfo/starlink>
> _______________________________________________
> Starlink mailing list
> Starlink@lists.bufferbloat.net <mailto:Starlink@lists.bufferbloat.net>
> https://lists.bufferbloat.net/listinfo/starlink <https://lists.bufferbloat.net/listinfo/starlink>

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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[Michael Richardson]

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Eugene Y Chang via Starlink <starlink@lists.bufferbloat.net> wrote:
    > I observe a difference in my phone’s batter life between urban and
    > rural usage. I expect the battery life to be significantly reduced with
    > Starlink.  And yes… if the phone isn’t communicating then the battery

Sure, but if my phone is plugged into my car, and it's sitting on the
dashboard, that still seems like a win to me.
(Except for people who were hoping to unplug their kids by going camping)

The service across northern ontario, along the Trans-Canada is still very
poor (okay, I was last there in 2018).

-- 
Michael Richardson <mcr+IETF@sandelman.ca>   . o O ( IPv6 IøT consulting )
           Sandelman Software Works Inc, Ottawa and Worldwide





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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[Mike Puchol]

There are certain resource-saving techniques that cannot be used in the DTC service, such as Location Area (LA). In terrestrial networks, an LA groups several cells, and as long as the UE is able to listen to pages from a cell in the same LA, it does not need to re-attach each time it roams to a different cell.

This was a big saver years ago, today with 4G/LTE and 5G, most UEs are constantly doing something in the background, and there isn't much gain from LA use. 

Something else that's much harder to implement is MIMO, as you don't get path diversity from a satellite. AST claims they will do this by using more than one satellite, however they haven't answered basic questions such as how will the UE compensate the huge differences in doppler shift on top of the multiple paths.

One other resource waste is the need to trick the device to overcome timing advance - effectively transmissions are blindly ACK'd by the satellite in the hopes they will go through, increasing the protocol overhead.

What I did always notice when I traveled to e.g. Kenya was that the lower density of cells caused my phone to consume its battery a lot quicker than in e.g. Europe. With DTC, the UE is always going to be at the edge of the cell, transmitting at maximum power, so the main use case is low data rate messaging and emergencies IMHO.

Best,

Mike


> On 04/06/2024 20:58 CEST Michael Richardson via Starlink <starlink@lists.bufferbloat.net> wrote:
> 
>  
> Eugene Y Chang via Starlink <starlink@lists.bufferbloat.net> wrote:
>     > I observe a difference in my phone’s batter life between urban and
>     > rural usage. I expect the battery life to be significantly reduced with
>     > Starlink.  And yes… if the phone isn’t communicating then the battery
> 
> Sure, but if my phone is plugged into my car, and it's sitting on the
> dashboard, that still seems like a win to me.
> (Except for people who were hoping to unplug their kids by going camping)
> 
> The service across northern ontario, along the Trans-Canada is still very
> poor (okay, I was last there in 2018).
> 
> -- 
> Michael Richardson <mcr+IETF@sandelman.ca>   . o O ( IPv6 IøT consulting )
>            Sandelman Software Works Inc, Ottawa and Worldwide
> 
> 
> 
> 
> _______________________________________________
> Starlink mailing list
> Starlink@lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/starlink

Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[David Lang]

Mike Puchol wrote:

> Something else that's much harder to implement is MIMO, as you don't get path 
> diversity from a satellite. AST claims they will do this by using more than 
> one satellite, however they haven't answered basic questions such as how will 
> the UE compensate the huge differences in doppler shift on top of the multiple 
> paths.

for the starlink version, the satellite adjusts it's transmit/receive 
frequencies to correct for the doppler shift so that the phones don't need to.

David Lang

Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[Mike Puchol]

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Yes, they correct doppler in a single stream - what I was alluding to is the MIMO advantage of terrestrial networks which cannot be easily replicated from multiple satellites, as the UE cannot correct multiple doppler shifts and timing advances unless it implements an NTN-specific approach.

Best,

Mike
On Jun 4, 2024 at 20:17 -0700, David Lang <david@lang.hm>, wrote:
> Mike Puchol wrote:
>
> > Something else that's much harder to implement is MIMO, as you don't get path
> > diversity from a satellite. AST claims they will do this by using more than
> > one satellite, however they haven't answered basic questions such as how will
> > the UE compensate the huge differences in doppler shift on top of the multiple
> > paths.
>
> for the starlink version, the satellite adjusts it's transmit/receive
> frequencies to correct for the doppler shift so that the phones don't need to.
>
> David Lang
>

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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[David Lang]

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Mike Puchol wrote:

> Yes, they correct doppler in a single stream - what I was alluding to is the 
> MIMO advantage of terrestrial networks which cannot be easily replicated from 
> multiple satellites, as the UE cannot correct multiple doppler shifts and 
> timing advances unless it implements an NTN-specific approach.

I am thinking that the doppler correction will be the same (or very close to it) 
for everything in a single cell.

now, timing that exact between multiple satellites is something I would see as a 
harder problem, but I'm not an expert there.

David Lang

>
> Best,
>
> Mike
> On Jun 4, 2024 at 20:17 -0700, David Lang <david@lang.hm>, wrote:
>> Mike Puchol wrote:
>>
>>> Something else that's much harder to implement is MIMO, as you don't get path
>>> diversity from a satellite. AST claims they will do this by using more than
>>> one satellite, however they haven't answered basic questions such as how will
>>> the UE compensate the huge differences in doppler shift on top of the multiple
>>> paths.
>>
>> for the starlink version, the satellite adjusts it's transmit/receive
>> frequencies to correct for the doppler shift so that the phones don't need to.
>>
>> David Lang
>>
>

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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[Sebastian Moeller]

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Curious, is that doppler correction applied individually per dishy, or per cell? If the latter do cells extend ahead or behind the satellite's projection onto the globe, or is there one or more beams ahead an another one or more behind?

On 5 June 2024 06:16:02 CEST, Mike Puchol via Starlink <starlink@lists.bufferbloat.net> wrote:
>Yes, they correct doppler in a single stream - what I was alluding to is the MIMO advantage of terrestrial networks which cannot be easily replicated from multiple satellites, as the UE cannot correct multiple doppler shifts and timing advances unless it implements an NTN-specific approach.
>
>Best,
>
>Mike
>On Jun 4, 2024 at 20:17 -0700, David Lang <david@lang.hm>, wrote:
>> Mike Puchol wrote:
>>
>> > Something else that's much harder to implement is MIMO, as you don't get path
>> > diversity from a satellite. AST claims they will do this by using more than
>> > one satellite, however they haven't answered basic questions such as how will
>> > the UE compensate the huge differences in doppler shift on top of the multiple
>> > paths.
>>
>> for the starlink version, the satellite adjusts it's transmit/receive
>> frequencies to correct for the doppler shift so that the phones don't need to.
>>
>> David Lang
>>

-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.

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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[Mike Puchol]

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The doppler shift will change as the satellite transitions overhead, this is very clear if you look at a spectrum capture of the narroband beacons with a static LNB, and can be corrected by the user terminal, as it is expecting this shift and has software written specifically to deal with it.

In the case of e.g. LTE, a UE is not designed to cater for a changing doppler shift, so this is compensated by the satellite. In a theoretical MIMO configuration where multipath is achieved by using beams from multiple satellites towards a UE’s location, the signals such as P-SS and S-SS from each satellite would arrive at the UE at different times, frequencies, and power levels.

Here is an interesting paper that discusses the topic: https://arxiv.org/pdf/1706.06013

Best,

Mike
On Jun 4, 2024 at 21:47 -0700, Sebastian Moeller <moeller0@gmx.de>, wrote:
> Curious, is that doppler correction applied individually per dishy, or per cell? If the latter do cells extend ahead or behind the satellite's projection onto the globe, or is there one or more beams ahead an another one or more behind?
>
>
> > On 5 June 2024 06:16:02 CEST, Mike Puchol via Starlink <starlink@lists.bufferbloat.net> wrote:
> > > Yes, they correct doppler in a single stream - what I was alluding to is the MIMO advantage of terrestrial networks which cannot be easily replicated from multiple satellites, as the UE cannot correct multiple doppler shifts and timing advances unless it implements an NTN-specific approach.
> > >
> > > Best,
> > >
> > > Mike
> > > On Jun 4, 2024 at 20:17 -0700, David Lang <david@lang.hm>, wrote:
> > > > Mike Puchol wrote:
> > > >
> > > > > Something else that's much harder to implement is MIMO, as you don't get path
> > > > > diversity from a satellite. AST claims they will do this by using more than
> > > > > one satellite, however they haven't answered basic questions such as how will
> > > > > the UE compensate the huge differences in doppler shift on top of the multiple
> > > > > paths.
> > > >
> > > > for the starlink version, the satellite adjusts it's transmit/receive
> > > > frequencies to correct for the doppler shift so that the phones don't need to.
> > > >
> > > > David Lang
> > > >
> --
> Sent from my Android device with K-9 Mail. Please excuse my brevity.

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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[David Lang]

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Sebastian Moeller wrote:

> Curious, is that doppler correction applied individually per dishy, or per 
> cell? If the latter do cells extend ahead or behind the satellite's projection 
> onto the globe, or is there one or more beams ahead an another one or more 
> behind?

sorry, I was specifically talking about the direct-to-cell capability. In one of 
the early presentations, Elon mentioned that one of the problems was doppler 
shift and the need to correct for it in the satellite so that the phones on the 
ground see the same frequency that they would get from a normal cell tower.

Since normal cell phones depend on timing signals from the tower, I am assuming 
that it's a single correction for the entire cell

David Lang

> On 5 June 2024 06:16:02 CEST, Mike Puchol via Starlink <starlink@lists.bufferbloat.net> wrote:
>> Yes, they correct doppler in a single stream - what I was alluding to is the MIMO advantage of terrestrial networks which cannot be easily replicated from multiple satellites, as the UE cannot correct multiple doppler shifts and timing advances unless it implements an NTN-specific approach.
>>
>> Best,
>>
>> Mike
>> On Jun 4, 2024 at 20:17 -0700, David Lang <david@lang.hm>, wrote:
>>> Mike Puchol wrote:
>>>
>>>> Something else that's much harder to implement is MIMO, as you don't get path
>>>> diversity from a satellite. AST claims they will do this by using more than
>>>> one satellite, however they haven't answered basic questions such as how will
>>>> the UE compensate the huge differences in doppler shift on top of the multiple
>>>> paths.
>>>
>>> for the starlink version, the satellite adjusts it's transmit/receive
>>> frequencies to correct for the doppler shift so that the phones don't need to.
>>>
>>> David Lang
>>>
>
>

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Re: [Starlink] SpaceX/Starlink says it's ready for a fall satellite-to-cell service with T-Mobile

[Alexandre Petrescu]

Le 04/06/2024 à 20:58, Michael Richardson via Starlink a écrit :
> Eugene Y Chang via Starlink <starlink@lists.bufferbloat.net> wrote:
>      > I observe a difference in my phone’s batter life between urban and
>      > rural usage. I expect the battery life to be significantly reduced with
>      > Starlink.  And yes… if the phone isn’t communicating then the battery
>
> Sure, but if my phone is plugged into my car, and it's sitting on the
> dashboard, that still seems like a win to me.
> (Except for people who were hoping to unplug their kids by going camping)
>
> The service across northern ontario, along the Trans-Canada is still very
> poor (okay, I was last there in 2018).

A phone plugged on the power of the car, but not on its roof antenna, 
and with windows closed - one should worry about strong EM waves and 
health in a first place.

Besides, such an in-car phone might have little chance to talk up to 
satcom 5G direct-to-cell (direct-to-smartphone, -to-device, 'D2D' but 
not 'device-to-device'; care about these terms, they are wrongly used 
and abundantly these days, probably because it's at the beginning).

Similarly, in-_plane_ smartphones might have similar problems to talk 
up(?) to satcom 5G.

It might work, maybe very badly, maybe with very low bandwidth and high 
latencies, if at all.

The frequency range around 800MHz (and not 1GHz-3.5GHz) has been 
mentioned for direct-to-cell.   This frequency set was often touted 
advantageously for car 4G communications but it has not really been 
used.  Maybe it'll be re-proposed for satcom 5G NTN, because it is 
little occupied but present in many smartphones.

Alex

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