A scheme to maximise use of a communications line by giving a larger share of the bandwidth to the modem at the end which is transmitting the mOSt information. Only one end of the connection has full bandwidth, the other has only a fraction of the bandwidth. Normally, which end gets the full bandwidth is chOSen dynamically. Asymmetrical modulation was made famous by the HST mode of the early high-speed modems from US Robotics. (1998-03-13)