Ha! There are a couple of other gems in the article. Entertaining and educational.
HN has enough people who could design a protocol and hardware to do exactly that with wifi. HN can't adequately explain dark matter, except to say it is a placeholder and to define how we observe the effect. Anything more than that is conjecture and anyone who says otherwise is a dirty rotten liar.
Really.
I hate the name Dark Matter. It's a horrible name.
But, someone here understands electromagnetism well enough, pulse signaling, electronics, binary, spectrums, radio, whatever. They could build some sort of mesh network to do exactly that. They could probably build it with COTS and do it for pretty cheap - and write you a damned good paper.
Don't have a damned clue what Dark Matter really is. Nope.
Edit: Hell, now that I think about it, someone here would probably set that up on like their ham radio stuff at 600 baud just for fun and make it all operate out of terminal.
That's a compliment, really. There'd be a Show HN and someone would tell them it had an Emacs shortcut.
But the description of the actual result is very clear and very well done.