If your school or office has several AirPort networks and one of them is experiencing interference, you may need to change the channel it uses.
By default, the AirPort software automatically selects the best available channel when your base station or your Time Capsule is plugged in. If your base station or Time Capsule is experiencing interference, try changing the channel it uses.
If you’re using your AirPort Extreme in the 5 gigahertz (GHz) range, you can’t change the channel it uses.
Open AirPort Utility, located in the Utilities folder in the Applications folder on a computer using Mac OS X, and in Start > All Programs > AirPort on a Windows computer.
Select the device you’re setting up, and then click Manual Setup. Enter the base station password if necessary.
Click AirPort in the toolbar, and then click Wireless.
Choose a new channel from the Channel pop-up menu.
Nearby wireless devices should be at least five channels apart. For example, if device A is set to channel 1, device B should be set to channel 6 or 11.
Computers on the AirPort network automatically tune to the channel your device uses. If you change the channel of a device, you don’t need to change the channel on computers connected to the wireless network.