[Starlink] Starlink filings for D-Band via Tonga

Alexandre Petrescu alexandre.petrescu at gmail.com
Thu Dec 21 05:25:01 EST 2023 

overlap: sorry! it is indeed MHz and not GHz, I overlooked that.

But the 117-137 _MHz_ bands are already used from ground to planes; the 
modernisations I have seen of it relate to automating the status voice 
bulletins, and maybe the use of IP over airbands.  Putting that on LEO 
sats, hmm, looks newer.  I am not an expert in that band.

D-band better for airplanes above clouds: I agree with the theory.

Alex

Le 21/12/2023 à 10:45, David Fernández via Starlink a écrit :
> There is no overlap between 117.975-137 MHz and 123 - 130GHz.
>
> D-Band will work much better for links on aircraft flying above
> clouds, less attenuation.
>
>> Date: Tue, 19 Dec 2023 18:27:19 +0100
>> From: Alexandre Petrescu <alexandre.petrescu at gmail.com>
>> To: starlink at lists.bufferbloat.net
>> Subject: Re: [Starlink] Starlink filings for D-Band via Tonga
>> Message-ID: <cd0f2602-9ce6-4b8e-94e4-481493e7a3c2 at gmail.com>
>> Content-Type: text/plain; charset=UTF-8; format=flowed
>>
>> Today I learn that 117.975-137 MHz is considered at ITU for aviation and
>> satellite [*].
>>
>> Note that range overlaps with 'ESSAFI's 123 - 130GHz.
>>
>> Maybe it is for that purpose - in-flight entertainment(?) that starlink
>> requested the D-band frequencies, and not for sat-sat nor sat-gnd.
>>
>> Alex
>>
>> [*]
>>
>> "Allocation of new frequencies to the aviation industry for aeronautical
>> mobile satellite services (117.975-137 MHz). The new service will
>> enhance bi-directional communication via non-GSO satellite systems for
>> pilots and air traffic controllers everywhere, especially over oceanic
>> and remote areas."
>>
>> text quote from this URL at ITU:
>>
>> https://www.itu.int/en/mediacentre/Pages/PR-2023-12-15-WRC23-closing-ceremony.aspx?utm_source=ITU+News+Newsletter&utm_campaign=c66517f297-EMAIL_CAMPAIGN_19_12_2023_ITU-NEWSLETTER&utm_medium=email&utm_term=0_-2f420cccc6-%5BLIST_EMAIL_ID%5D&ct=t(EMAIL_CAMPAIGN_19_12_2023_ITU-NEWSLETTER_INT)&mc_cid=c66517f297&mc_eid=3ca8d7193e
>>
>> Le 06/12/2023 à 13:02, Alexandre Petrescu via Starlink a écrit :
>>> In another context someone pointed me to spacex saying 'D-band' in
>>> april 2023 in this "NTIA Docket No. 230308-0068 / Docket
>>> NTIA-2023-0003"
>>> https://www.ntia.gov/sites/default/files/publications/spacex.pdf
>>>
>>>  From that text, I understand it would, or could, be for sat-to-gnd.
>>>
>>> Le 23/11/2023 à 14:40, Alexandre Petrescu via Starlink a écrit :
>>>> Le 17/11/2023 à 23:56, Ulrich Speidel via Starlink a écrit :
>>>>> Right. Word from the Tongan government's MEIDECC is that it's D band
>>>>> as per the filing and that the reports on W band are wrong.
>>>>>
>>>> Can MEIDECC point me to the precise place at the ITU filing that says
>>>> it's D band?  Thank you!
>>>>
>>>> I could not find the word 'D-band' or 'D band' in the 'ESIAFI
>>>> application file  ("'ESIAFI II API-A(1).mdb"  at ITU
>>>> https://www.itu.int/ITU-R/space/asreceived/Publication/DisplayPublication/53068)
>>>>
>>>> People nominate bands in various ways.  As an example of a potential
>>>> confusion, there is this other wikipedia image that shows the freqs
>>>> in question (123-ish, 170-ish GHz) being called 'EHF' by ITU and 'W'
>>>> by IEEE.  Further to the confusion, the diagram says that the EU,
>>>> NATO and US ECM (not sure what  is ECM) call 'D' band something
>>>> around 2 GHz or so, which is much lower than this 123-ish, 170-ish
>>>> GHz.
>>>> https://en.wikipedia.org/wiki/Radio_spectrum#/media/File:Frq_Band_Comparison.png
>>>>
>>>> I will look later at maybe joining that ITU group to ask it there as
>>>> well.
>>>>
>>>> Alex
>>>>
>>>>> Beyond that, they're not authorised to say anything except that yes,
>>>>> it's a genuine filing.
>>>>>
>>>>> I don't think Tonga is a likely launch base (no large tracts of land
>>>>> to launch a rocket from, except as some locals would probably tell
>>>>> you, from the driveway of a certain royal residence). Who knows.
>>>>>
>>>>> I'd also say that SpaceX filings to the FCC at least have a track
>>>>> history of being superseded by the next filing a few weeks later
>>>>> with completely different parameters. Whether that's just rapid
>>>>> prototyping at SpaceX or whether they're deliberately designed as a
>>>>> groundhog version of April Fool's Day for the competition's lawyers
>>>>> to keep them spend money on litigation while SpaceX spends on
>>>>> innovation is anyone's guess. Similarly, having slept over it, the
>>>>> Tongan story could be a SpaceX attempt at establishing a "flag of
>>>>> convenience" operation, or it could simply be another of Elon's
>>>>> pranks to whip us and the media all up into a frenzy to keep people
>>>>> talking about his enterprises.
>>>>>
>>>>> On 17/11/2023 11:43 pm, Ulrich Speidel wrote:
>>>>>> OK, so this seems to be related to a somewhat bigger development
>>>>>> that Starlink is pushing through Tonga as the regulatory authority:
>>>>>>
>>>>>> https://www.reddit.com/r/spacex/comments/175ttvz/spacex_files_29988satellite_wband_network_using/
>>>>>>
>>>>>>
>>>>>> https://www.spaceintelreport.com/spacex-files-29988-satellite-w-band-network-using-kingdom-of-tonga-as-regulatory-home/
>>>>>>
>>>>>>
>>>>>>
>>>>>> ESIAFI 1 was bought by Tonga - it was the old COMSTAR 4 satellite
>>>>>> and named after their women's rugby team.
>>>>>>
>>>>>> Quite why they've chosen Tonga as regulatory home - no idea. Maybe
>>>>>> because they think Tonga owes them a favour. Currently trying to
>>>>>> find out more - stay tuned.
>>>>>>
>>>>>> On 17/11/2023 6:29 am, David Fernández via Starlink wrote:
>>>>>>> Hi Alex,
>>>>>>>
>>>>>>> "A person on twitter seems to be saying this filing is precisely the
>>>>>>> filing that spacex did at FCC"
>>>>>>>
>>>>>>> Would you mind linking to that tweet, if it is public?
>>>>>>>
>>>>>>> Thank you.
>>>>>>>
>>>>>>> Regards,
>>>>>>>
>>>>>>> David
>>>>>>>
>>>>>>>
>>>>>>>> Date: Thu, 16 Nov 2023 14:27:03 +0100
>>>>>>>> From: Alexandre Petrescu <alexandre.petrescu at gmail.com>
>>>>>>>> To: starlink at lists.bufferbloat.net
>>>>>>>> Subject: Re: [Starlink] Starlink filings for D-Band via Tonga
>>>>>>>> Message-ID: <805d52ce-b517-49b9-a053-8306cd20b8aa at gmail.com>
>>>>>>>> Content-Type: text/plain; charset=UTF-8; format=flowed
>>>>>>>>
>>>>>>>> Towards clarification,
>>>>>>>>
>>>>>>>> The .mdb file of the ITU filing can be read with Excel (tab Data ->
>>>>>>>> leftmost button 'Access'). The .mdb is on the web page of the ITU
>>>>>>>> filing, at the bottom of the page.
>>>>>>>>
>>>>>>> https://www.itu.int/ITU-R/space/asreceived/Publication/DisplayPublication/53068
>>>>>>>> It might be that this 'ESIAFI II' is just a name because of some
>>>>>>> reason.
>>>>>>>> There are some interesting dates like '06/03/2023', '13/03/2023'
>>>>>>> and
>>>>>>>> '20/03/2023' and '6/10/2023'.
>>>>>>>>
>>>>>>>> There is much data about orbits, powers, beams that I dont know
>>>>>>> how to
>>>>>>>> interpret. I would need the precise description of the database
>>>>>>> format,
>>>>>>>> but I dont know where to get it from.
>>>>>>>>
>>>>>>>> The frequencies are listed, as I interpret these fields: 123 GHz
>>>>>>> - 130
>>>>>>>> GHz centered on 126.5 GHz, 158.5-164 c 161.25 and 167-174.5 c
>>>>>>> 170.75.
>>>>>>>> About D-band: I am not sure what is precisely a 'D band' and I
>>>>>>> think
>>>>>>>> that discussion about bands is very complicated. I know there is
>>>>>>>> wikipedia page about it, yes.
>>>>>>>>
>>>>>>>> A person on twitter seems to be saying this filing is precisely the
>>>>>>>> filing that spacex did at FCC; but comparing the numbers shows some
>>>>>>>> differences: total sats per plane differ at some altitudes like
>>>>>>> at 525km
>>>>>>>> altitude: ITU says 3600 sats whereas FCC says 3360 sats. There
>>>>>>> can be
>>>>>>>> speculations as to why they differ as there can be errors of
>>>>>>> various
>>>>>>>> people including myself.
>>>>>>>>
>>>>>>>> The person on twitter tells that ITU filing is in this table,
>>>>>>> but I dont
>>>>>>>> know how he generated it. Not sure whether he made some syntax
>>>>>>> error.
>>>>>>>>> Altitude (km) Inclination (degrees) Satellites per Plane Planes
>>>>>>>>> Total Satellites
>>>>>>>>> 340 53 110 48 5280
>>>>>>>>> 345 46 110 48 5280
>>>>>>>>> 350 38 110 48 5280
>>>>>>>>> 360 96.9 120 30 3600
>>>>>>>>> 525 53 120 28 3600 [nota by me: FCC says 3360 and not 3600, see
>>>>>>>>> table below]
>>>>>>>>> 530 43 120 28 3600
>>>>>>>>> 535 33 120 28 3600
>>>>>>>>> 604 148 12 12 144
>>>>>>>>> 614 115.7 18 18 324
>>>>>>>>>
>>>>>>>> I found this earlier FCC document has this table at this URL
>>>>>>>> https://docs.fcc.gov/public/attachments/FCC-22-91A1.pdf (not sure
>>>>>>>> whether it is the most authoritative, but at least the mathematics
>>>>>>>> 28*120 at altitude 525 does make sense to be 3360).
>>>>>>>>
>>>>>>>>> Altitude (km) Inclination (degrees) Orbital Planes sats/plane
>>>>>>> Total sats
>>>>>>>>> 340 53 48 110 5280
>>>>>>>>>
>>>>>>>>> 345 46 48 110 5280
>>>>>>>>>
>>>>>>>>> 350 38 48 110 5280
>>>>>>>>>
>>>>>>>>> 360 96.9 30 120 3600
>>>>>>>>>
>>>>>>>>> 525 53 28 120 3360 [nota by me:
>>>>>>>>> 28*120 == 3360 indeed]
>>>>>>>>>
>>>>>>>>> 530 43 28 120 3360
>>>>>>>>>
>>>>>>>>> 535 33 28 120 3360
>>>>>>>>>
>>>>>>>>> 604 148 12 12 144
>>>>>>>>>
>>>>>>>>> 614 115.7 18 18 324
>>>>>>>>>
>>>>>>>> Alex
>>>>>>>>
>>>>>>>>
>>>>>>>> Le 16/11/2023 à 10:30, Alexandre Petrescu via Starlink a écrit :
>>>>>>>>> Le 15/11/2023 à 16:48, David Fernández via Starlink a écrit :
>>>>>>>>>> I have got news about the recent filing by Starlink for the
>>>>>>> use of
>>>>>>>>>> frequencies in D-band:
>>>>>>>>>>
>>>>>>> https://www.itu.int/ITU-R/space/asreceived/Publication/DisplayPublication/53068
>>>>>>>>>>
>>>>>>>>>> This has been done via Tonga, not the USA, and is for both,
>>>>>>> uplink and
>>>>>>>>>> downlink frequencies, although only downlink seems to be
>>>>>>> allocated now
>>>>>>>>>> for satellite use.
>>>>>>>>> Thanks for the pointer.
>>>>>>>>>
>>>>>>>>> It is the first time I hear about this 'ESIAFI II'
>>>>>>> constellation. I
>>>>>>>>> understand it is a different thing than the starlink existing
>>>>>>>>> constellation.
>>>>>>>>>
>>>>>>>>> It adds to the list of plans of LEO Internet constellations
>>>>>>> (starlink,
>>>>>>>>> kuiper, oneweb etc.)
>>>>>>>>>
>>>>>>>>> Alex
>>>>>>>>>
>>>>>>>>>> Regards,
>>>>>>>>>>
>>>>>>>>>> David
>>>>>>> _______________________________________________
>>>>>>> Starlink mailing list
>>>>>>> Starlink at lists.bufferbloat.net
>>>>>>> https://lists.bufferbloat.net/listinfo/starlink
>>>>>> --
>>>>>> ****************************************************************
>>>>>> Dr. Ulrich Speidel
>>>>>>
>>>>>> School of Computer Science
>>>>>>
>>>>>> Room 303S.594 (City Campus)
>>>>>>
>>>>>> The University of Auckland
>>>>>> u.speidel at auckland.ac.nz http://www.cs.auckland.ac.nz/~ulrich/
>>>>>> ****************************************************************
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