IEC 61000-4-3 is the basic standard for the immunity of equipment to radiated radio-frequency electromagnetic fields. The disturbance it represents is the ambient field created by radio and television transmitters, mobile telephones and base stations, wireless data networks, radar and industrial radio-frequency equipment. The standard covers the frequency range from 80 MHz upwards, and the current edition extends the range to 6 GHz to include the wireless services that now operate in the higher bands. It defines the test facility, which may be an anechoic chamber or, for lower frequencies, a shielded room with absorbing material, and it specifies the field uniformity procedure that must be performed over a grid of positions on the calibration plane before any equipment is tested. The field is generated by an antenna driven by an amplified signal that is amplitude modulated with a 1 kHz sine wave to simulate the modulation of real transmissions, and the test is normally performed at 3 V/m or 10 V/m although higher levels are used for special environments. Susceptibility of the interconnecting cables is also addressed.