Data Flow
Simplex is one way transmission (e.g., radio or TV)
Half duplex is two-way transmission, but you can transmit in only one direction at a time (e.g., walkie-talkie)
- The amount of time half duplex communication takes to switch between sending and receiving is called turnaround time (also retrain time or reclocking time)
Full duplex means that you can transmit in both directions simultaneously with no turnaround time
Application determines which data flow method to use
Full duplex indicates that the capacity is divided (half of the capacity in one direction half in the other)