The name "shortwave" originated during the beginning of radio in the early 20th century, when the radio spectrum was divided into long wave (LW), medium wave (MW), and short wave (SW) bands based on the length of the wave. Shortwave radio received its name because the wavelengths in this band are shorter than 200 m (1,500 kHz) which marked the original upper limit of the medium frequency band first used for radio communications. The broadcast medium wave band now extends above the 200 m / 1,500 kHz limit.
