In simplex channel, the flow of data is

Concept:

The data flow between the two devices can be in simplex, half-duplex, and full-duplex modes.

Simplex:

• In Simplex, communication is unidirectional. Only one of the devices sends the data and the other one only receives the data.
• The channel capacity is used by only one device all the time.

Example: A CPU sends data while a monitor only receives data.

Half Duplex:

• In half-duplex, both the stations can transmit as well as receive but not at the same time. When one device is sending others can only receive and vice-versa
• The channel capacity is shared by both the devices but at a time only once the device uses the full capacity.

Example: A walkie-talkie

Full Duplex:

• In Full-duplex mode, both stations can transmit and receive at the same time.
• The channel capacity is shared by both communicating devices at all times.

Example: Mobile phones