In another article[*] about this WRC event's discussion they mention
more frequencies ; some seem to be on and around the 'ESSIAFI II
frequencies, and even beyond D-band's upper limit of 170GHz (limit told
by wikipedia). It cites these frequencies by refering to document
resolution COM6/17, document to which I have no access unfortunately.
102-109.5 GHz
151.5-164 GHz
167-174.8 GHz
209-226 GHz
252-275 GHz
For comparison, I recall below the 'ESSIAFI II frequencies from
https://www.itu.int/ITU-R/space/asreceived/Publication/DisplayPublication/53068
:
- 123000 - 130000 MHz
- 158500 - 164000 MHz
- 167000 - 174500 MHz
Alex
PS: the article about WRC freqs discussions is from
https://www.6gworld.com/exclusives/itu-defines-frequency-bands-for-6g-studies/
and says, among other things:
The International Telecommunication Union (ITU) has defined several
frequency ranges in the sub-Terahertz band for future 6G network
studies. The 2023 World Radiocommunication Conference
<https://www.6gworld.com/a-look-ahead-to-wrc-23-what-to-look-for-why-its-important/>
(WRC-23) resolution COM6/17 establishes the following areas for the
development of the next generation of mobile communications:
* 102-109.5 GHz
* 151.5-164 GHz
* 167-174.8 GHz
* 209-226 GHz
* 252-275 GHz
According to the resolution, the Radiocommunication Sector (ITU-R)
must complete the investigations in time for the WRC-31. The task has
already been added to the event’s preliminary agenda.
The studies have to consider the technical and operational
characteristics of terrestrial 6G systems operating in these suggested
frequency bands, including the evolution of IMT through technological
advances and spectrally efficient techniques.
The resolution goes on to say that ITU-R must take into account the
deployment scenarios envisaged for 6G systems and the requirements of
high data traffic, such as in dense urban areas and at peak times.
The investigations also need to include the developing countries’
demands and set up a timeframe in which spectrum would be required.
Le 21/12/2023 à 11:25, Alexandre Petrescu via Starlink a écrit :
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.petre...@gmail.com>
To: starlink@lists.bufferbloat.net
Subject: Re: [Starlink] Starlink filings for D-Band via Tonga
Message-ID: <cd0f2602-9ce6-4b8e-94e4-481493e7a...@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.petre...@gmail.com>
To: starlink@lists.bufferbloat.net
Subject: Re: [Starlink] Starlink filings for D-Band via Tonga
Message-ID: <805d52ce-b517-49b9-a053-8306cd20b...@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
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School of Computer Science
Room 303S.594 (City Campus)
The University of Auckland
u.spei...@auckland.ac.nz http://www.cs.auckland.ac.nz/~ulrich/
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