[ubuntu] Atheros AR9485 drop coection Ubuntu 15.10

Dear fellows,

I'm new to ubuntu.
I'd like to master it.
Anyway, I install Ubuntu on my laptop, it seems that my coection is not good.
My Wifi is coected to inteet.
Sometime I can coect to inteet and sometime can't.
But it is still coected to wifi.
When it can't coect to inteet, my inteet browser took a long time , and ends without any page opened.

I hope you guys can help me with my problem.
I'm sorry for my English.
Thank You.