FIELD: radiotelephone communications. SUBSTANCE: digital radiotelephone system uses vocoders converting analog voice signals into digital format suited to radio transmission. In most cases, highest possible data transmission speed is chosen to ensure optimal characteristics of audio signal. If system is busy in excess of particular threshold value determined on fixed station of system, instruction is sent to some or all vocoders to change over to lower data transmission speed so as to increase number of communication channels. In addition, portable subscriber's device can separately change over data transmission speed on its vocoder depending on state of charge of its battery. EFFECT: facilitated and more reliable adaptation to increasing connected load. 10 cl, 8 dwg
