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. AlexBeyond 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, DavidDate: 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/53068It might be that this 'ESIAFI II' is just a name because of somereason.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 knowhow tointerpret. I would need the precise description of the databaseformat,but I dont know where to get it from. The frequencies are listed, as I interpret these fields: 123 GHz- 130GHz centered on 126.5 GHz, 158.5-164 c 161.25 and 167-174.5 c170.75.About D-band: I am not sure what is precisely a 'D band' and Ithinkthat 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 likeat 525kmaltitude: ITU says 3600 sats whereas FCC says 3360 sats. Therecan bespeculations as to why they differ as there can be errors ofvariouspeople including myself. The person on twitter tells that ITU filing is in this table,but I dontknow how he generated it. Not sure whether he made some syntaxerror.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 324I 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/planeTotal sats340 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 324Alex 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 theuse offrequencies in D-band:https://www.itu.int/ITU-R/space/asreceived/Publication/DisplayPublication/53068This has been done via Tonga, not the USA, and is for both,uplink anddownlink frequencies, although only downlink seems to beallocated nowfor satellite use.Thanks for the pointer. It is the first time I hear about this 'ESIAFI II'constellation. Iunderstand 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.) AlexRegards, David_______________________________________________ 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) The University of Auckland u.spei...@auckland.ac.nz http://www.cs.auckland.ac.nz/~ulrich/ ****************************************************************_______________________________________________ Starlink mailing list Starlink@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/starlink
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