@Dooooo My router has no antennas, so cannot make any adjustment as woozle suggested and the solution of RE upstairs and WPA downstairs, I confess it had already crossed my mind. The problem is that...

Hi! In my home network the router is in the ground floor, in a not central zone of the house, and I have a range extender upstairs. The result is very poor. I am thinking of buying a powerline kit...