So I am currently using powerline adapters to supply my house with internet, but I just found out about coax to ethernet adapters. I just want to check a few things that I was unable to clear up.
So here’s the setup that I want to have. I have AT&T internet service.
AT&T-mandated router --> ethernet to coax --> coax wires already in my house --> coax to ethernet --> router/wireless AP in a better location in my house
Would this work?
This should explain how MoCA ethernet works.
Testing the MoCA Adapters is around 8:42 in the video.
On to whether it works or not, yes, it would absolutely work.
What you could do is have the mandated gateway at one point in the house with your configured SSID & pass key and have the AP you want at another point in the house with the SSID & passkey which would effectively create a mesh network in the home using the MoCA adapter to act as the Ethernet backhaul line.
Thanks!
Theres also tech to use the power lines in your house but idk if that went past automation and small data. 
MoCA has much better throughput.
I’m actually using powerline adapters, what you are talking about right now, but it’s not amazing. It’s decent, and much cheaper than coax. It’s a decent solution, but it is very limited by range. The best usage of it would be to have a short powerline adapter bridge to a better area for a wireless access point / router. Which is what I’m using it for.
The problem with the powerline adapter is that it loses a serious amount of performance the further away you go from the source powerline adapter. If there is a high-bandwidth isp connection, it’s not a huge issue, but with a low bandwith connection, like I have, it just becomes not great. Better than just have wifi in a bad area, but not great. Also they really don’t take well to having multiple powerline adapters running on the same power network. That’s why I wanted to try cable, since it preserves much more of the connection, and doesn’t run on the power infrastructure in my house, which isn’t that great.
I actually upgraded from using powerline adapters as Ethernet backhaul to WiFi mesh network xD.
My old set up was there was a router and AP on the 2nd floor and through powerline connected the 2nd AP. The problem with that setup is the 2nd AP had a network speed around 20~30mbps while the main AP had a wireless throughout of around 200~300mbps.