Starlink has bufferbloat. Bad.
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From: J Pan <Pan@uvic.ca>
To: Ulrich Speidel <u.speidel@auckland.ac.nz>
Cc: "starlink@lists.bufferbloat.net" <starlink@lists.bufferbloat.net>
Subject: [Starlink] Re: Starlink and Iran
Date: Thu, 15 Jan 2026 09:10:01 -0800	[thread overview]
Message-ID: <CAHn=e4gBsYWrK=8DSdAegvFwvsBupR2FD=YaUiBVzY5mMZy+Ng@mail.gmail.com> (raw)
In-Reply-To: <5c0a93c4-21b2-4297-b4bb-befce0963a93@auckland.ac.nz>

easier to attack gps?
https://github.com/narimangharib/starlink-iran-gps-spoofing/blob/main/starlink-iran.md
although not all technically correct. "inhibitGps" is a user choice
through the mobile app ("Use Starlink positioning exclusively") not
system determination, but gps spoofing is indeed there. starlink could
be authorized to decode military-grade gps signals as well?
--
J Pan, UVic CSc, ECS566, 250-472-5796 (NO VM), Pan@UVic.CA, Web.UVic.CA/~pan


On Thu, Jan 15, 2026 at 1:51 AM Ulrich Speidel via Starlink
<starlink@lists.bufferbloat.net> wrote:
>
> I guess you would have all been following the reporting on Iran & how
> Starlink is being used a communication backroute out of the country, but
> also how it's being jammed by the Iranian government. Today, I received
> a petition request from an NGO asking me to sign a petition to get Elon
> to turn on D2C (direct-to-cell) over Iran, and it's phrasing it in such
> a way that it'd "turn the lights on".
>
> My 5 cents worth:
>
> Jamming: Over every location in Iran, there are several dozen Starlink
> satellites visible at any one time that Dishys on the ground can in
> principle communicate with (read: 25 deg plus above the horizon and
> clear of the geostationary arc). There are purportedly tens of thousands
> of Dishys in the country. Each of those Dishys (when working)
> communicates with one of the satellites, and does so by pointing a beam
> at the satellite - which points a beam back. Even two Dishys in close
> vicinity of each other generally talk to different satellites.
>
> To jam communication between a Dishy and a satellite you have to insert
> the jammer into the transmission path - either by pointing it at the
> satellite's receiver, or by pointing it at the Dishy. In either case,
> you want to do so ideally from the direction of the respective
> transmitter that the receiver is listening to, because there isn't all
> that much sensitivity if you're jamming off beam. Basically, because
> signal power drops of with the square of the distance, you need to be
> fairly close to a Dishy in order to out-shout the transmitter at the far
> end of the beam if you're trying to jam from outside the beam.
>
> Jamming the main traffic channels to Dishy is an uphill task - for a
> total blackout, you'd have to cover a good part of the 2 GHz total in
> Ku with sufficient power in terms of spectral density to cause mischief.
> Not easy.
>
> Likewise, pointing your jammer at the satellite(s) is mission impossible
> because there's every chance that the satellites will be listening to
> Dishys that are in a different direction from you.
>
> There would I guess be some opportunity in terms of jamming management
> channels (e.g., access grant channel) but even this is complex with that
> number of satellites around.
>
> Plus those babies move, so you need jammers that can track. And 15
> seconds after you're worked out what you need to point where, Starlink
> changes the game on you.
>
> The Independent quotes "a specialist in digital repression and associate
> director of the Technology Threats and Opportunities Program at Witness"
> https://www.independent.co.uk/news/world/middle-east/iran-internet-blackout-protest-starlink-musk-b2900101.html
> saying that they think it's GPS jamming. For all I know Starlink doesn't
> need GPS - while Dishys have GPS receivers, Starlink's got its own
> positioning system, too. Also, GPS jamming is fairly common globally and
> it's not known to be impairing Starlink all that much.
>
> D2C: Maybe someone should have asked the NZ Commerce Commission for
> advice first. They figured out a long time ago that D2C isn't quite
> there yet (and may never get fully there). It's only capable of
> supporting a comparatively small number of devices per unit area on the
> ground, and apart from a small number of premium phones, with text and
> perhaps RCS/MMS only. And that's with a telco on the ground that's
> actually cooperating and making frequencies available. One NZ, the New
> Zealand telco who partners with SpaceX on the D2C here, had its
> marketing department shouting the virtues from the rooftops until the
> Commerce Commission filed criminal charges. They're still in the game
> but when I bought a new mobile phone the other day, it took me several
> minutes to find the page that listed compatible phones. The service is
> now a little less prominent on their home page - you have to scroll a
> little to find it. Also, word doesn't seem to have gotten around that
> your mobile phone - even if satellite-capable - will connect to
> terrestrial networks with priority. So Iranians would have to go pretty
> far out into the desert just to TXT. Oh, and cellphones are a lot easier
> to jam than Dishys...
>
> Of course, that's not the only consideration here. Using Starlink is
> illegal in Iran, and I guess getting caught with a Dishy is a bit risky
> there at the moment. But RF direction finding 50k+ Dishys that change
> transmit frequency a couple of times a minute isn't trivial: It requires
> specialised equipment and skill, both of which are likely to be in short
> supply at the moment. So I suppose visual identification of Dishys (from
> the air or high rise buildings) might be a more promising tactic. But of
> course they can be camouflaged to an extent as well as moved.
>
> Also, Starlink tends to be more of a technology for underserved rural
> areas rather than cities in countries with high Internet penetration
> rates - which Iran is one of. So it's likely that many of the tens of
> thousands of Dishys are in rural locations where there haven't been any
> large protests.
>
>
> --
> ****************************************************************
> Dr. Ulrich Speidel
>
> School of Computer Science
>
> Room 303S.594 (City Campus)
>
> The University of Auckland
> u.speidel@auckland.ac.nz
> http://www.cs.auckland.ac.nz/~ulrich/
> ****************************************************************
>
>
>
> _______________________________________________
> Starlink mailing list -- starlink@lists.bufferbloat.net
> To unsubscribe send an email to starlink-leave@lists.bufferbloat.net

  parent reply	other threads:[~2026-01-15 17:11 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-01-15  9:51 [Starlink] Starlink and Iran Ulrich Speidel
2026-01-15 10:06 ` [Starlink] " Inemesit Affia
2026-01-15 10:30   ` Ulrich Speidel
2026-01-15 10:44     ` Inemesit Affia
2026-01-15 11:16       ` Ulrich Speidel
2026-01-15 10:32 ` Inemesit Affia
2026-01-15 10:51   ` Ulrich Speidel
2026-01-15 11:17 ` David Lang
2026-01-15 11:59   ` Sauli Kiviranta
2026-01-15 14:08     ` David Lang
2026-01-15 15:29       ` Sauli Kiviranta
     [not found]   ` <3af2ac06-e098-4c79-869d-9c389959ca07@gmail.com>
     [not found]     ` <q9304244-661o-3qsr-o6rp-9q1nqq09r419@ynat.uz>
     [not found]       ` <4ba64a41-bbbf-4fb5-adb0-c77c15e4ca0f@gmail.com>
2026-01-15 16:20         ` Inemesit Affia
2026-01-15 20:12   ` Ulrich Speidel
2026-01-15 17:10 ` J Pan [this message]
2026-01-15 20:07   ` Ulrich Speidel
2026-01-15 21:47     ` Oleg Kutkov
2026-01-16  4:18       ` Ulrich Speidel
2026-01-16  8:12         ` Frantisek Borsik
2026-01-16  8:24           ` Inemesit Affia
  -- strict thread matches above, loose matches on Subject: below --
2026-01-15 14:50 David Fernández
2026-01-15 16:11 ` Oleg Kutkov
2026-01-15 17:13   ` J Pan
     [not found] <176849731431.1249.14387618908540773471@gauss>
2026-01-15 17:42 ` Colin_Higbie
2026-01-15 18:56   ` Jim Forster
2026-01-15 20:15     ` Ulrich Speidel
2026-01-15 20:27   ` Ulrich Speidel
2026-01-15 20:30     ` Hayden Simon
2026-01-15 21:06       ` Ulrich Speidel
2026-01-15 21:09         ` Hayden Simon
2026-01-15 21:20           ` Ulrich Speidel
2026-01-15 21:23             ` Hayden Simon
     [not found] <176851123059.1249.8585659892308012167@gauss>
2026-01-15 21:49 ` Colin_Higbie
2026-01-15 23:15   ` Frantisek Borsik
2026-01-16  0:13   ` Ulrich Speidel
2026-01-16  1:29     ` David Lang
2026-01-16 22:55       ` Frantisek Borsik
2026-01-16 23:06         ` J Pan
     [not found]     ` <13187.1768590201@obiwan.sandelman.ca>
2026-01-16 23:30       ` Ulrich Speidel
2026-01-17  0:07         ` David Lang
2026-01-17 21:56           ` Ulrich Speidel
2026-01-19 20:39             ` David Lang
2026-01-28  3:09               ` Ulrich Speidel
2026-01-28  3:30                 ` David Lang
2026-01-28  4:02                   ` Mike Puchol
2026-01-28  9:05                     ` Ulrich Speidel
2026-01-28  9:53                       ` David Lang
2026-01-28 20:43                         ` Ulrich Speidel
2026-01-28 20:55                           ` David Lang
2026-01-17 18:32         ` Michael Richardson
2026-01-17 18:38           ` Inemesit Affia
2026-01-17 19:25             ` Michael Richardson
2026-01-17 22:12           ` Ulrich Speidel

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