What is the concept of Simplex and Half Duplex and Full Duplex dialogs?

Answer 1

Simplex transmission allows data to travel only in a single, pre specified direction. An example from everyday life is doorbell the signal can go only from the button to the chime. Two other examples are television and radio broadcasting. The simplex standard is relatively uncommon for most types of computer-based telecommunications applications; even devices that are designed primarily to receive information, such as printers must be able to communicate acknowledgement signals back to the sender devices.

In half duplex transmission messages can move in either direction , but only one way at a time. The press to talk radio phones used in police cars employ the half-duplex standard; only one person can talk at a time. Often the line between a desktop workstation and a remote CPU conforms to the half duplex patterns as well. If another computer is transmitting to a workstation, the operator cannot send new messages until the other computer finishes its message to acknowledge an interruption.

Full duplex transmission works like traffic on a busy two way street the flow moves in two directions at the same time. Full-duplexing is ideal for hardware units that need to pass large amounts of data between each other as in mainframe-to-mainframe communications