Welcome to the forum
I had a similar problem with my own internet connection (wired network though, with a cable modem).
A couple of things to try, if you can, would be to plug the modem directly into your PC (assuming your modem is separate, and not combined with your router), see if your internet connection remains active then.
A quick call to your ISP (or an email) would help clear up whether the problem is at their end as well. This is what my own problem turned out to be.
You've tried rebooting the modem and/or router?