Simplex Half Duplex Full Duplex - Modes of Transmision - Networking Tutorial #11

The Transmision is Characterised by:

• The direction of the exchanges
• The synchronization between the transmitter and receiver 
• The transmission mode:the number of bits sent simultaneously  

Modes of Transmission

Simplex

Simplex communication is a communicationchannel that sends information in one direction only. ... A duplex communication channel requires twosimplex channels operating in opposite directions. For example, in TV and radio broadcasting, information flows only from the transmitter site to multiple receivers.

Half Duplex

(adj.)Refers to the transmission of data in just one direction at a time. For example, a walkie-talkie is ahalf-duplex device because only one party can talk at a time. In contrast, a telephone is a full-duplex device because both parties can talk simultaneously.

Full Duplex

Full-duplex data transmission means that data can be transmitted in both directions on a signal carrier at the same time. For example, on a local area network with a technology that has full-duplex transmission, one workstation can be sending data on the line while another workstation is receiving data.

Serial and Parallel Transmission 

Number of elementary units of information (bits) that can be simultaneously translated by the communications channel

In a serial connection, the data are sent one bit at a time at a time over the transmission channel.

Parallel connection means simultaneous transmission of N bits

An Asynchrous connection,in which each character is sent at irregular intervals in time (for emaple a user sending characters entered at the keyboard in real time).

Synchronous connection, the transmitter and receiver are paced by the same clock.