A transceiver (25) for transmitting and receiving digital data represented as stair-stepped sinusoidal waveforms over twisted pair lines interconnecting nodes of a network. The transmitter (302) of the transceiver converts square waves into the stair-stepped sinusoidal waveforms by utilizing a number of current sources for supplying differing amounts of current to a resistor coupled across the twisted pair lines. Shift registers control a set of switches which control the direction and the amount of current flowing through the resistor. Thereby, the output voltage across the resistor can be controlled to produce signal to the shift registers. The receiver (303) of the transceiver re-convert received stair-stepped sinusoidal waveforms back to their respective digital signals.