FIELD: communication.
SUBSTANCE: present invention relates to communication engineering and can be used in a data retransmission system. For normal operation of a transmitting device and a receiving device number of levels, selected by transmitting device and which are to be used, should exceed number of levels required for retransmission of a code word, wherein new data must not be transmitted.
EFFECT: technical result is identification of data for retransmission.
25 cl, 13 dwg, 3 tbl
