The findings are mainly pertinent to crowded urban areas in Britain, but could also pertain to the U.S., especially in apartment buildings where radio waves pass through neighbors' walls, one U.S. analyst said.

The report, issued by independent authority Ofcan and prepared by Mass Consulting, calls for more regulation of devices in the 2.4GHz band to avoid interference.

Craig Mathias, an analyst at Farpoint Group, said such interference in the U.S. is "not a big problem," except possibly in high-density residential buildings.

Mathias has urged apartment developers to install Wi-Fi for use by all residents on a leased basis to avoid overlapping Wi-Fi networks between apartments and condominiums.

But he also said he has seen situations where baby monitors and wireless security cameras have caused Wi-Fi interference. Also, microwave ovens can cause interference.