Wi-Fi over Coaxial (2006)

I've been doing this for years! FYI if you have XFinity or Verizon FiOS you get one end of this for free. All FiOS routers support MoCA, even if you're connected to the ONT with direct attach BaseT (it's used internally for the set top box LAN segment too). Also XFinity Cable modems (at least, the last one I had 2 years ago from them!) supported it too, but not out of the box, it was a hidden option in the settings menu. Depending on the gear, you could get as much as 2.5Gbps through the channels, but beware! just like WiFi, this is shared bandwidth for every device. Its also a bit sensitive to daisy chained coax splitters -- it prefers a flat topopgraphy for best signal performance (though you should really be doing that anyway). Also unlike WiFi, MoCa is really zero config needed past initial enable.

MoCA 2.5 is 2.5gbps; works great and inexpensive.

It's not at all like HomePNA in that it does not shit all over the RF spectrum. Please do not use these powerline bridges; they are awful in all respects and should never have been allowed to be marketed.

Also, doing the thing in the article isn't ideal either, though there are always a lot of interesting RF things to try with WiFi. Look into leaky feeders / leaky coax for instance.

Huh, good to know! I will keep these in mind when it comes time to replace my parent's ethernet powerline adapters.

At the very low frequencies involved, the impedance mismatch is pretty much negligible.

The 50Ω to 75Ω mismatch loss doesn't make a big difference in practice. The cable loss on the other hand...

If you have 60 foot of RG6 you would have 6 dB of loss at 2500 MHz[1]. That is a factor of 4. So you would only have a quarter of the normal signal and output power.

If you use a splitter you have to take that loss into account as well.

[1] https://www.net-comber.com/cable-loss.html

Yes. Depending on the frequency(s), the spaces between cuts on the waveguide vary. But it's basically just open space in the cable/waveguide letting frequency leakage. Coax or waveguide (hollow cabling) can be used.

This project uses leaky feeders? https://en.wikipedia.org/wiki/Leaky_feeder

I must have grossly misread TFA. The way I read it, he is just using an existing coax cable as the wifi RF in/out on 2 APs. Exactly as one would use a commercially available MoCA bridge.

Even ignoring the impedance mismatch, loss in typical 75 ohm coax at 2.4GHz is going to be something like 0.5dB per metre. Far worse again at 5GHz. That's going to add up quickly.

Every coax system in every house I've ever seen (in the US) has been a mishmash of cables and splitters of random length and quality, usually with unterminated branches.

That means absolutely horrid performance at RF frequencies. Cable TV is mostly okay with this poor quality, you can still get a picture from the bad signal, but it might be fuzzy or dark. I can't imagine wifi would work at all under those conditions. You'd get reflections with random phase offset, and it'd probably totally destroy the signal.

What you want is probably possible, but it would require a dedicated line to each terminal run back to a central location with no splitters. At that point, you're just running worse ethernet with extra steps.

There are now. They would have been very rare back in 2006.

Perhaps because the link was running over coaxial?

In 2006, it would have been netstumbler or kismet, and on 2.4GHz they're all in use in proximity.

In all of my WiFi routers, even the cheapest one, this is done automatically.