Wireless interference can cause slow service, choppy streaming, and connection drops.

Your wireless router broadcasts in radio frequencies that are shared by many wireless products such as: cordless phones, Bluetooth devices, baby monitors, as well as other routers. As a result, wireless signals within the home may interfere with one another. All Points cannot control these radio frequencies in your home. You would experience the same interference issues regardless of your Internet Service Provider.

Apple has a very informative article on wireless interference here.