Q: airplay works fine using cable and doesn't work using WiFi

hello .. I have got a macbook pro and an iPhone5 .. my macbook and my iPhone connected to the same WiFi but for some reason the airplay don't work .. so I tried to use a (cable) goes from the router to the macbook .. and i turned on (sharing internet) so my macbook can become a WiFi .. from that my iPhone is connected to the WiFi (macbook pro WiFi) and the airplay was working fine .. the thing is i don't like the cable idea because my router on the first floor and my macbook on the second floor.. so any one have any tips for me .. by the way i need the airplay because i was streaming using (Reflector)