EN 50065 -2-1 : January 2003: signalling on low-voltage electrical installations in the frequency range 3khz to 148,5 khz: part 2-1: immunity requirements, for mains communications equipment and systems operating in the range of frequencies 95 kHz to 148,5 kHz and intended for use in residential, commercial and light industrial environments / European Committee for Electrotechnical Standardization