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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?

#81

Post by tdeck »

wolvoleo wrote: post #74
bb88 wrote: 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.

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.

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

#82

Post by tdeck »

SOLAR_FIELDS wrote: post #64
bb88 wrote: 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:…

Not knowing much about radio hardware your post made me wonder why we don’t see too many options for radios that can do this outside the military. Is it because there’s rarely a practical use case outside of avoiding jamming? Or is the hardware to do so prohibitively expensive?

There is actually a lot of fairly inexpensive SDR hardware aimed at amateurs, and other ways to do cheap packet radio. But outside the amateur radio community you might not hear about it because you need a license to transmit.

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

#83

Post by tdeck »

idontwantthis wrote: post #19
firefax wrote: post #13

Old fashioned phone trees can be really useful IMHO OP. We used them when I worked in a school. If there was winter weather, you'd call say, everyone with a last name from A to G in the staff directory, someone else calls G to K, and so on and so forth. You can combine the phone tree with literal runners -- so basically, someone takes their burner and calls suburbs A,B,C and D and then the runners go out and pass the…

Radio stations too. The US civil rights movement sometimes used radio DJs to call people out for protests.

I've read that pirate radio is still a big part of protest movements and Mapuche resistance in Chile.

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

#84

Post by Rover222 »

nubg wrote: post #41
bromuro wrote: post #39

Earlier quoted context omitted.

Why it is important?

I guess because a single Starlink subscription would be 30-80% of their monthly income.

Starlink is currently free in the country (of course they still need to get access to a terminal)

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

#85

Post by tdeck »

_moof wrote: post #28
badc0ffee wrote: post #26

Earlier quoted context omitted.

I had to think for a second to realize that HF means lower frequency than VHF, not high frequency in an absolute sense.

It's very silly that "high frequency" is among the lowest frequencies, and that we wound up with Very, Ultra, Super, Extremely, and Tremendously High Frequencies!

It's because when the term was first used, newer electronics to generate those frequencies had only recently become available.

The HF band is 3-30 MHz. Maritime navigation was operating on 500kHz (.5MHz) for most of the 20th century because that was what Marconi's alternators used at the beginning of the system. These machines produced the carrier frequency mechanically by rotating a disc with lots of tiny magnets on it at high speed.

https://en.wikipedia.org/wiki/Alexanderson_alternator

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

#86

Post by Rover222 »

culi wrote: post #46
ekr wrote: post #44

Earlier quoted context omitted.

It has been reported in the press that Starlink subscription fee has been waived for Iran, so people with receivers can use it for free.

Pretty sure the cheapest receiver you can buy is still $600

No, starlink Mini is half that price.

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

#87

Post by heljara »

markus_zhang wrote: post #79
nerdsniper wrote: post #72

Earlier quoted context omitted.

It's trivially easy to watch the entire radio frequency range at once and triangulate the location of any transmission. If someone more powerful than you wants to stop you, they can.

Just curious what if the transmitter hops freq around? What is the tech to track these?

It's (scarily) available in the commercial sector[1][2] from space if you have the need to purchase their services.

Suffice to say, military and intelligence agencies are probably a few generations ahead of this and you won't find them commenting on strategic capabilities on HN.

1. https://www.he360.com/ 2. https://spire.com/space-reconnaissance

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

#89

Post by segmondy »

AnimalMuppet wrote: post #8

If the phones are working, 56k modem.

without searching the internet. imagine you have no internet. do you have any computer with a modem? do you know anyone that does? can you get access to one? do you have dialup software? do you have a dial up international internet provider? can you find one? remember you need to do all of this without the internet. can you sign up for one? would they allow you to pay for it from Iran? the best time to get ready is before SHTF

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

#90

Post by cl3misch »

mhitza wrote: post #88

Briar is an option in such cases but its not realtime. Mote of an email/newsletter app that hops delivery across Bluetooth/ WiFi. https://briarproject.org/

But unfortunately Android only? (not the fault of Briar, still unfortunate)
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