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Ask HN: Iran's 120h internet shutdown, phones back. How to stay resilient?

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Re: Ask HN: Iran's 120h internet shutdown, phones back. How to stay resilient?

#101
post #31

States like Iran have signal catchers, where they can get a rough idea where a signal is coming from through triangulation. The US military has had this for over 20 years now. Often these coordinates are fed in as targets into weapons systems. If you're going the radio route these come to mind: Meshtastic: 1W, one band, local. Useful if Iran doesn't know about it. But easy to jam and probably triangulate. Wifi Halow:…

WSPR carries almost no payload data and by default it literally broadcasts your location. You could modify it but it will still take ages to send a short sentence which is probably the last thing you want when you want to avoid getting caught. Short bursty spread spectrum hopping seems to be more what the military do and they also care deeply about triangulation.

My point is that if you can't do spread spectrum, you've got to think about creative ways to get messages out. Something in the noise floor looks promising even if it's not fast. Further I've seen designs for WSPR that allow the radio to be something like a TTL buffer chip.

If you "announce" yourself you become a target for the signal intelligence folks. Sat phones became a liability in the 2nd gulf war, as they lit up like a beacon saying: "Bomb goes here!".

Re: Ask HN: Iran's 120h internet shutdown, phones back. How to stay resilient?

#102
post #48

Earlier quoted context omitted.

But did all the nodes and repeaters update to the version of meshtastic with routing? Meshcore started with routing out of the box. I don't think it's the noise that's too high, my original understanding of the meshtastic 2.0 protocol (from this video: https://www.youtube.com/watch?v=7v6UbC5blJU ) was that an edge device would receive priority. So the message might go the wrong direction, say. Or, worse, a meshtastic…

I would say there are significantly more nodes on the Meshtastic network with the latest routing than there are MeshCore nodes. A gap that will likely only increase over time. In Melbourne, Australia I was able to pick up 450 nodes on Meshtastic while I got zero on MeshCore after weeks of searching.

With networks like meshtastic there's this sweet spot of density. Not enough density, no message throughput. Too much density, also no message throughput.

It's one of these things where for the early adopters it worked great, but then the late adopters got pissed off because it didn't work.

As for meshtastic: I'm one god damned fucking hop away from my friend through a repeater. And it doesn't fucking work!

Re: Ask HN: Iran's 120h internet shutdown, phones back. How to stay resilient?

#103
post #81

Earlier quoted context omitted.

WSPR carries almost no payload data and by default it literally broadcasts your location. You could modify it but it will still take ages to send a short sentence which is probably the last thing you want when you want to avoid getting caught. Short bursty spread spectrum hopping seems to be more what the military do and they also care deeply about triangulation.

Just to underscore this WSPR sends 50 BITs of data in 110.6 seconds - a data rate of less than 2 baud. It's not practical for really any kind of message passing. Using CW (Morse code) would be at least an order of magnitude faster.

But then you're no longer in the noise floor. That makes you triangulable and bomb-able.
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