Wireless connection issue macbook pro

Hey guys,

I have this issue with my airport on my macbook pro. If i connect to a wireless network, (it doesn't matter which type or from who ive tried several different broadband providers and ive tried using my phone as a hotspot too) but i lose the connection after maybe 20-30 mins if i am uploading or downloading a big file.

I dont why this happens but i lose all the signal bars on the airport icon at the top of my screen and it says no connection available, if i then search for my networks i will see them try to connect, it then asks me for the password even though it should have remembered it and it says connection time out, very puzzling :/

On a different issue usb tethering does not work on my phone, well sometimes it works and sometimes it doesn't, im using a HTC HD Desire and my internet is fine on the phone.

My macbook pro is being stubborn, can anyone help me?

Thanks

Do you use various wi-fi spots throughout the day/week/month? You probably have several networks stored and it's confusing Airport as to which to connect to. Try this... Go into System Preferences>Network>Wi-Fi and click on Advanced. Remove any networks in that list and start over with the one you want to use at that moment. See if that makes any difference.