Cell phones and other wireless devices like Wi-Fi routers are two-way microwave radios that operate in the same frequency range as microwave ovens, but at a much lower power. All wireless signals—whether from cell phones, tablets, computers, or wireless routers—are microwave radiation, a type of non-ionizing radiation that is also called radio-frequency radiation. When the World Health Organization reviewed the research in 2011, they grouped all of these radiofrequency signals as a Class 2 B Carcinogen.