Abstract: A method and apparatus for transmitting binary data trains of 0 and 1 data bits, or combinations of these data bits over a communications network. The data bits are converted into pulses whose polarity changes from pulse to pulse, so as to enable an optimal exploitation of the transmission channel with a low error rate. The pulses generated by an apparatus of the present invention have a signal shape that produces a minimum inter-symbol interference. Processing and evaluation of the transmitted pulses are performed by a processor, so that a minimal error rate is attainable even under unfavorable transmission conditions.