Downloading stops when change the working channel/band!!!‏‏

[Amr Al-Hamad]

Hello,
 
     I am using AR9280 wireless card and E2000 linksys router to be able to connect to 5 GHz band. The problem happens when I begin
a downloading process from internet, then change the working channel or band via GUI during this downloading process. The
downloading stops.I want to ask if I could solve this problem (prevent the stopping) via wpa_supplicant? Also I want to ask if this
stopping happens due to the authentication/ association processes?

     let me say that I wanna make a smooth hand off between bands and channels.
 
     

     really I am so confused and I need your help.
 
Thanks :)