From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: mail.toke.dk; spf=pass smtp.mailfrom=; dkim=fail; arc=pass; dmarc=fail (Used From Domain Record) header.from=uvic.ca policy.dmarc=none Received: from mail-yx1-xb134.google.com (mail-yx1-xb134.google.com [IPv6:2607:f8b0:4864:20::b134]) by mail.toke.dk (Postfix) with ESMTPS id 0D5A5BB9471 for ; Thu, 15 Jan 2026 18:11:14 +0100 (CET) Received: by mail-yx1-xb134.google.com with SMTP id 956f58d0204a3-64472121ad5so814584d50.0 for ; Thu, 15 Jan 2026 09:11:14 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1768497013; cv=none; d=google.com; s=arc-20240605; b=ZjPKkuBZsrOP604dvQzqx15R9wwqEMvMqIvjzxjkCBtoU/eunxvMO1lggn2AdXEC0k RyFnBlCeKmvN/RcwLsIbJlziQj2xoDhZPY24Wn8xC96GoglAPzWCoDcG8AvlQZbQq6uY j7zSYJyAyDUeaOG38WMvtOisjxDgU/xJjGRylz/sp75Y8LCTiibtmYqjcXDuBuL6G+um QbT+yX4il9tbD4SE6r8pb5ZRHNdhrmVVa9rCXwYQSTjLIDX1LOfMVz0jqI8PCGPuqRSV WyHa5dwCehBiOFo39BluC9K/U4fjsRU634At/JcrmdKFiU5UB48h2Ad3vHPGsDfN9tPQ rR0g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20240605; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version; bh=WJ6fdF9InnFKgpRBUJsn6S9Flx/X28wQofb6Lij98Ag=; fh=S8o3IabSzyXUgp0IUhW00qeM8gEHZm5wbFUJFfz5p9c=; b=Ka/JILvoCW1H4lglvsQJuetiqMiNpJPsfvKYuMBeggeyILQk/MJNbydm1lx9Arn3EN QNklFd5H4sND56d27ltLw2k6F7z7Khn/u2qgar5BFat8btwvUzdyyUnImg6RDD2cemQT HyaMM0llC4lWJ6jJAwajvo+CYWlLlRq9kFVGkSFDKBOsJO4d6dnRyPuJS5ZOVCmQ62Vj Hr6MeQaj2h08rWltjSMPXZH7RdzLfG1bAbKQS+S00Fz2Shqgfqrm+jfFlq+4dNEAe2YX amTbJdrV/85fU8aA+kgfbWhVjRKW4/q8x2Tsy341F5k82vmD8SSqa3bGvC63S422/LRt WgIw==; darn=lists.bufferbloat.net ARC-Authentication-Results: i=1; mx.google.com; arc=none X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768497013; x=1769101813; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=WJ6fdF9InnFKgpRBUJsn6S9Flx/X28wQofb6Lij98Ag=; b=dPEJ5OkuaGzcikvNbPf0w4cGVwd2nqbRG/McJ3hcLLPS15XnEhk+RaTvDOPgGU2HEo +C4x0q0xe4ceZzkhm4gsIUZMXnLw4jZ33H2mIUmGG0Z9WYwwQrtLaG90nn+9bJtbeaK3 eNydByY0ZqnDLdMG6mpBTjMoO8rHvbb8UmnVmiNLZlJTicchgoe1DpcwM1J4jTBjc3D6 1S18gwmRAnNyaLpaGTf6M9gcJTet+q8fw/OM/5Xax8iiO/4wOVyvrmakHZGXD/kr1vaK amRND2rJKb8uYEj/YBdU8twKxhVmx2Ee6GBDwbJ9AtramkKowj3lOjVqtZtqFA9dUkO9 qZ0w== X-Gm-Message-State: AOJu0Ywx/1a2nDCu+lZcRY/ABUWub44y6dL6ZBylXFIZJlV5d8DNT4f7 dkcfv7UHyug9P0z/aoL1Vkha4YJ/Q1gUqtDY87ItBFoOKxtXp//Jl/coLerwu8xxEH+B8tS90OF 2q2ixzVhuyXsCROjm3rqGClak3M0K1WEEM2zxS1g= X-Gm-Gg: AY/fxX7MmvgXLchbPwiTpZ9peiwInHXnoF0dIbvzJGkpJXVF+ny7P6kYAkE2a4xk6v/ 8lC85sRaJujDd1cnzUp3xOOABdA5BSEwT57DtYalx2pQzyoZZJp+PUFdf1kjzDwS/B5Ku4A1swB eGNTy1zvSAHSQT/8QTBqhrCl5CUudTLErVl8qhuXJmT4hynadhG7Ob+wQiNEzjFQrBBUY5vpotP IDXgOQLOmS0bQ69HrmIwlM+dCrS368SKA8n5UU5vWryup9lsv/Oji7gR0P+nyxD+MUoopI= X-Received: by 2002:a53:ac9b:0:b0:649:119a:3b2f with SMTP id 956f58d0204a3-6491647e607mr433731d50.20.1768497012643; Thu, 15 Jan 2026 09:10:12 -0800 (PST) MIME-Version: 1.0 References: <5c0a93c4-21b2-4297-b4bb-befce0963a93@auckland.ac.nz> In-Reply-To: <5c0a93c4-21b2-4297-b4bb-befce0963a93@auckland.ac.nz> From: J Pan Date: Thu, 15 Jan 2026 09:10:01 -0800 X-Gm-Features: AZwV_QioXLTyFYy5Ns_7VIFZNLSyf7_wWaw-gWcE8oHuMjCZBN594tYC_4tMykI Message-ID: To: Ulrich Speidel Cc: "starlink@lists.bufferbloat.net" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Message-ID-Hash: U7SYUHQHV4ZH3UDF4T3XFWP3NAVP6IAF X-Message-ID-Hash: U7SYUHQHV4ZH3UDF4T3XFWP3NAVP6IAF X-MailFrom: panatuvicdotca@gmail.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list Subject: [Starlink] Re: Starlink and Iran List-Id: "Starlink has bufferbloat. Bad." Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: easier to attack gps? https://github.com/narimangharib/starlink-iran-gps-spoofing/blob/main/starl= ink-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/~pa= n On Thu, Jan 15, 2026 at 1:51=E2=80=AFAM Ulrich Speidel via Starlink 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-blacko= ut-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