FIELD: variable-speed data transfer over communication channel at predetermined equal-length time intervals. SUBSTANCE: all data blocks have similar optimal size, that is each block has equal quantity of data bits, and data block size does not change with its transfer speed to exclude unnecessary complications. This is attained due to the fact that mentioned optimal size of data block is chosen so as to ensure that each predetermined time interval for all attainable transfer speeds is fully occupied by useful information. Optimal size of data block is found considering maximal rate of change of transfer speed in communication channel and lowermost attainable transfer speed. EFFECT: facilitated evaluation of optimal size of data block for its reliable variable-speed transfer over communication line. 17 cl, 10 dwg
