It has only one caveat but tends to work very well. Example picture.
I live in a tiny flat in a building with 3 others. The router of our Wifi is on the first floor and on the 2nd floor i have very poor internet. How can i improve this? I don't think Wifi extenders are the answer. I don't need good Wifi in the entire building, I just want good Wifi in my tiny flat. At the moment a powerline adapter with Wifi seems the best idea, but I'm not exactly an expert. Any help is welcome.