Ok Thank you for your clarification.
I am using my old HP computer (only a,b,g,n) and it is connected to this network I thought It will show me something like "ac" when you check the wireless properties. Right now my HP showing me it's connected to this 5G network and when I click wireless properties it showing me 802...n. So that's why I am confused and concern. I am not an expert.
I have FIOS at my home. I will check with my phone (which has ac capabilities )to verify the speed.