Comment by bb88
1 day ago
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: 1W, can possibly hop between bands, but probably also really easy to jam and triangulate.
WSPR: Possibly good, transmitters can hide in the noise floor, and can go long distances with 100mW of power, but slow. Probably triangulable, very easy to jam once located in the spectrum. Data can be transmitted and received with off the shelf components.
Military Radios: Very good. Transmitters can frequency hop, making triangulation and jamming difficult. Also encryption. You can easily transmit in the same frequency space that Iran would be using to avoid jamming. But also, mostly unobtanium. I have heard stories about US military radios showing up at Ham Fests.
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.
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.
Radio spectrum is licensed, and licenses are very expensive.
There are several bands for Amateur radio in US/EU/AU, but it is explicitly forbidden to use any kind of encryption on them. So no one can sell devices that use encryption on those bands.
And I doubt Iran was friendly to amateur radio in the first place. E.g. in USSR it was crazy to think of any non-approved radio.
I mean who can stop you from transmitting anything you want at any frequency? Licenses etc only matter when the rule of law is a thing.
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