Net Terms Full-Duplex vs. Half-Duplex Full-duplex and half-duplex are terms used to describe the transmission of data. Full-duplex means that data can be transmitted in both directions (sending and receiving) on a signal carrier at the same time. For example, if a network is using technology that has full duplex data transmission, one computer can send data on a line, while another computer can receive data on that same line. Half-duplex data transmission also means that data can be transmitted in both directions, just not at the same time. This can be an especially frustrating experience if you are familiar with the term Internet telephony (see the May 31, 1997 issue), a new technology that allows users to make telephone calls via their personal computers.