Wi-Fi is a shared medium that operates in the unlicensed RFs within the 2.4GHz and 5GHz range. Radio frequency interference can be generated by almost any device that emits an electro-magnetic signal. The problem of RF interference is only exacerbated by the new 802.11n standard standard, which uses multiple radios within an AP to transmit streams in different directions to achieve faster connectivity. The best approach to dealing with interference is to reduce the transmit power to make better use of the limited number of channels.”]
Source: https://www.csoonline.com/article/2125616/coping-with-wi-fi-s-biggest-problem–interference.html