# If global radio communications systems are disrupted, what is the alternative?

An event has occurred several thousand kilometers from the surface of the Earth. Let's assume some sort of tear in the universe has appeared, from which extra-dimensional or exotic energy is pouring out. It has affected all wireless communications globally.

1. What alternative wireless communication form exists that might survive such disruption i.e. is less prone to interference than radio waves.

Now I'm not quite certain what affect varying radio frequencies and wavelengths have on communication distance and resistance to interference, so:

1. Is there any science or science-adjacent justification for why some kinds of radio signals still work while others don't?

2. Alternatively, can providing more power to a radio transmission overcome such interference or not (and I know that's asking a lot because we don't know the precise nature of the interference, but could that make sense in some way)?

3. Finally, is there a possibility that wired communication might also be disrupted?

• Which radio frequencies are affected? All of them? #4 is a definite possibility. – Alexander Aug 16 at 18:01
• The question basically asks what are the effects of some unspecified form of magic. And it also asks what means of communication won't be affected by said unspecified form of magic. If you really want answers you must explain what exactly is affecting wireless communication; I cannot think of any natural phenomenon which would disrupt both AM medium wave broadcast radio and 2.4 GHz spread-spectrum frequency hopping Bluetooth. (And how come people can still see? Light and radio waves are the same thing.) – AlexP Aug 16 at 18:41
• You added a science-based tag to a question about an extra-dimensional tear in the universe. OK then. Extra dimensional exotic energy is well known to only affect radio at 19.2 cm, 32 cm, and 110 cm through 125 cm. – puppetsock Aug 16 at 20:10
• A source of interference that will interfere with both fiber optic and copper communications and not kill all life on the planet is hard to imagine. – EDL Aug 17 at 3:49
• The OP wants an event to disrupt all radio communication. That is very clear. The fact that individuals cannot think of an answer does not mean the question is unclear or cannot be answered. This should be reopened. – Willk Aug 17 at 16:10

What alternative wireless communication form exists that might survive such disruption i.e. is less prone to interference than radio waves.

Free-space optical communication. Lasers and LEDs and photodiodes and so on. It can only be line of sight, and long range links are generally point-to-point, but it does exist and work right now. You couldn't keep your mobile phone in your pocket any more, but other than that these things could be replaced with new technologies and carry on working. Quite a lot of these devices are already in use and in production, though getting enough out to relink the radio-networked bits of world will probably take some time.

Remember that communication with sattelites is only line-of-sight... launching a new optical-only satellite constellation would be a major undertaking, but it is just money and time. The technology is already available.

Is there any science or science-adjacent justification for why some kinds of radio signals still work while others don't?

Shortwave bounces off the ionosphere. Microwaves can be scattered off the troposphere. VHF and the like is line of sight, mostly, but you can still do stuff like bounce it off the moon.

These are all very, very difference mechanisms because the behaviour of radio changes drastically at different frequency ranges. One mechanism won't break them all, unless it is basically magic. A deliberately engineered attempt to break all of them could be done with force majeure.

There are many techniques like frequency hopping spread spectrum, and clever communication protocols like WSPR which are highly resilient to noise and jamming.

Alternatively, can providing more power to a radio transmission overcome such interference or not

Depends entirely on the nature of the interference. Handwave it as you wish.

Finally, is there a possibility that wired communication might also be disrupted?

Doubtful, at best. Something like a Carrington event might affect some radio and some wired communications, and of course you're discussing something that may as well be magic, so you can feel free to define its scope. Fibre optic certainly not.

• :%s/site/sight/g And please explain why terahertz electromagnetic waves are not affected by the magic which disrupts gigahertz waves. – AlexP Aug 17 at 12:39
• @AlexP the author is free to handwave their own magic as they see fit, as I suggested. And I'm sure you're entirely capable of pressing the edit button yourself. – Starfish Prime Aug 17 at 13:20

You need bullet proof, unassailable technology to solve this problem!

# The Post

No radio to be disrupted. No electricity or wires needed. Before there ever was radio based communications or even the telegram, there was the Post Office.

A letter requires no fancy equipment to make and no exotic energy defeating technology to deliver.

• I never thought of snail mail as wireless, but there is a definite absence of wires, so yeah. – EDL Aug 18 at 15:24

The original form of radio — spark gap transmitters — using morse code is highly resistive to disruption. CW morse communications are the military’s fall back solution in the advent of nuclear war because standard AM/FM/PSK/FSK communications are likely to fail.

Also time synchronous communications are very robust. Things like cells phones and towers use this technique. The synchronous nature of the encoding allows the receivers to accurately demodulate carriers] signals that are below the thermal noise of the universe. I am not suggesting our current cell system would keep working, just that a scheme using similar mathematics could be developed to permit wireless communications in the environment you are describing.

It is imaginable that fiber optics systems would be unaffected by any interference you are describing and the majority of the internet is now running on a fiber backbone — as I understand it. If copper lines carrying analog signals are disrupted then it would seem that a similar digital comms system like DSL would continue working

As observed before, lasers and photodetectors could be rigged to constructed to provide point to point communications. Line of Sight is straight forward. And, under special circumstances, with proper long IR wavelengths, long haul skip communication is possible — again using digital recovery techniques.

• It certainly was the case not so long ago that morse (in the for of CW/OOK) was the best fallback for all purposes, but modern robust communication protocols and techniques like frequency-hopping spread-spectrum are substantially more robust to noise and jamming and can have much larger bandwidth by way of a bonus. – Starfish Prime Aug 18 at 9:10
• @StarfishPrime -- I'd probably use a slow-speed, FEC-equipped OOK or (A)FSK (similar to AMTOR/PacTOR) over DSSS if I was designing an "ultimate fallback protocol" (DSSS is easier to overlay onto an existing NB signal than FHSS is, and also can work with a non-agile TX LO) – Shalvenay Aug 18 at 14:21
• @Shalvenay that's because your goals and limitations differ slightly from those of the military. Not to disparage your choices... they're pretty good, after all, but they represent the military state-of-the-art back in the 80s. – Starfish Prime Aug 18 at 17:29