The ITU Radiocommunication Assembly, considering that, to maintain a satisfactory standard on international radiotelephone circuits operating at frequencies below 30 MHz and connected to the national network, it is necessary to compensate, at the transmitting end, for most, if not all, of the variations in the subscriber’s speech volume and of the losses between the subscriber and the international exchange.
ITU-R F.1111-1 FRENCH-1995 Referenced Document
ITU-T G.101 The transmission plan (Study Group 12)*， 2003-11-01 Update