The tip is put a mirror behind your wii u and move around any reflecting surfaces.
For a full story about how i did it you can go ahead and read it:
WARNING WALL OF TEXT!!!!!
Well i recently got a wii u and of curse the game room is not in the center of my house. In fact even the wifi modem is in the same room and since we wanted internet in the bottom roms i had to get some eterneth cable and an access point.
Si here i was playing some mh3u and if had to go to the bathroom "bleep bleep bleep your conection is unstable" waath but the bathroom is right next to that room, si figure i could never play on my bed but i was wrong!! i could but on the floor at the foot of the bed by the door /mad/ , if i wanted to lie down i couldn't becouse on those 8 ft the signal just died.
So i started to remember my network clases and then i just laugh at myself becouse i wasn't focusing my efforts in the right direction.
A little education first, so you can do your set up well, im assuming you are not expert so here goes: first the wii u apparently has a wifi signal or blue tooth signal, so we will treat it has any radio signal. Now radio signals travel in waves like this: (((( )))), if you have anything blocking them the waves gets weaker like a wall, but there are some elements that reflect them or weakens them even more to the point that even if you are on the next room you will get no signal: like mirrors, bathroom tiles, pipes with water, WATER, any reflecting surface.
So knowing this i started to move stuff, first moved my wii u wich was on top of my old dvd player (metal), moved it to the bottom of my tv table wich is made of wood, now i managed to move it a litte closer and the wii u was not touching anyting metal (wich miyamoto said could reduce the signal), also i looked around and there it was!!!! a mirror between the bathroom and the game room also since the bed is in the far next room no way in hell the signal was going to get there, it was a miracle i could get it by the door of my bedroom.
So after removing the mirror and moving the wii u the bathroom signal was clear, even though the tiles and the pipes makes the signal weaker.
Now the signal wasn't strong enugh for me to be playing confortable on my bed. So it ocurred to me well let's use that mirror for the good of mankind!!. Since is a reflecting surface it was blocking my signal but if i put it on the back it will bounce the signal to the rigth direction (this trick has been done with wifi routers using beer can you can google it), so after carefully putting the mirror behind the wii u and aiming it to where i would be playing in my room well IT WORKED!!, is funny that now i can't connect by the door like i used to but now i can play on my bed, why you ask? well by reflecting it on the mirror your signal goes stroger becouse you are making it almost like a streigth line and go to only one side like this: mirror> |))))), so you can almost snipe the place you want it to go and gain those 8 ft you wanted or maybe more.
Now i'm happy and my wife too since we can now play MH3U on the bed, she plays on the 3ds and i play on the gamepad and it works perfect!!.
Still haven't tested in other places or how far i can get, since i sleep on the far corner of the room and next to it is the street, and we are on a second floor and i doubt the signal will go down to the floor level.
Well there you have it hope it helps you.
PS: You can block the signal of any room of the house by doing this too with a correct set up, but don't do that to your litte sister or brother /dev/