[Starlink] Starlink and Iran

Ulrich Speidel
2026-01-15T09:51:25Z

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/
****************************************************************