How do I make my macbook pro (2011, OS10.7.5) reconnect to the network when the signal goes down? My problem is the wifi internet is not stable and regularly goes out for 4-5 seconds at minimum up to ~40 seconds, although the network stays up. However it is annoying because my macbook does not automatically reconnect, and instead sits there saying nothing is connected when it detects a network doesn't share internet anymore.

By regularly I mean 7-8 times per hour I have to manually rechoose the network. On windows 7 the computer stays connected, and I just have to wait while hitting refresh for the signal to come back. I would like to be able to have it stay connected but without a signal like what happens when I am in bootcamp.

Edit:


  Are you sure it's Wifi outages and not a DNS server problem?


I'm sure it's not DNS. I've tried opening firefox in bootcamp (where it doesn't disconnect me automatically), as well as pinging various websites from the console. What happens is the signal is dropped, but not the network. I am still connected to (w/out internet) and see the network while I have no internet in windows.

In osx what happens when the signal is lost is that the entire network is dropped as if I was never connected to anything at all. And it does not auto rejoin. I have to manually click the network icon and reconnect, however it sits there for a while after I click moving up and down.

I assume what is happening is that the signal is not back yet when it happens, so it is trying for several seconds until it comes back.
Are you sure it's Wifi outages and not a DNS server problem? If you've been using Safari, check with other browsers – if they get through while Safari doesn't, set OS X to use an alternative DNS server (System Preferences > Network > Advanced…), e.g. OpenNIC.org, OpenDNS.com