NOTE: This post is outdated. After 6 years of progress in AirPort Extreme (and the Software Utility used to set it up), I have posted an updated set of instructions: Extend Wireless Range with AirPort Extreme (Updated).
Is your wireless network area just too small for comfort? Are you always walking your laptop just out of range? If you have an AirPort Extreme router, your problem can be solved by adding another AirPort Extreme to your network.
It is a simple matter of getting the settings right. For reliability and maximum range, I chose to “wire” them together, even though you should be able to extend them wirelessly.
I put my AirPort Extreme base stations at opposite ends of the house, making it easy to use our laptop computers anywhere in the house, with range to spare onto the back patio.
The trick is to make the second one (the one NOT connected to your DSL or Cable Modem) a “bridge” connection.
First, get the “main” base station set up and running correctly. Make sure you have enabled the encryption scheme of your choice (choose the most secure encryption algorithm that all of the computers on your network can connect to).
Once your “main” AirPort Extreme base station is running and all of your computers can connect to it, connect the “extension” AirPort Extreme to the first one. Mine are connected through a “Network Switch” (similar to the network “hubs” of a few years ago).
Set up the Internet Connection Sharing to “Off (Bridge Mode).” The Wireless Options should be the same as on the “main” base station.
Note: Name the network the SAME on both AirPort Extreme routers. Also, use the same password for both stations. This way, your computer can connect to either base station with only one “key” in the keychain. It worked for me.
Set up each base to choose its wireless channel automatically.
When you are at one end of the house and move to the other end of the house, momentarily “turn off” your laptop’s AirPort:
and turn it right back on again:
It will find the base with the highest signal strength automatically: