Items that can interfere with a Wi-Fi network
Any of the following items can interfere with a Wi-Fi network signal:
Microwave ovens.
Direct Satellite Service (DSS) radio frequency leakage.
The original coaxial cable that came with certain types of satellite dishes. Contact the manufacturer and obtain newer cables.
Certain electrical devices, such as power lines, railway tracks and power stations.
Cordless telephones that operate in the 2.4 or 5 gigahertz (GHz) range. If you have problems with your phone or base station communication, change the channel of your base station. For instructions, see Set wireless options.
Other Wi-Fi networks.
Nearby wireless devices using adjacent channels. For example, if device A is set to channel 1, device B should be set to channel 6 or 11.
Metal objects between your computer and the base station.
See the Apple Support article Resolve Wi-Fi and Bluetooth issues caused by wireless interference.