Ø   Transmission mode refers to the mechanism of transferring of data between two devices connected over a network . Ø     It is also called  Communication Mode.   Ø   These modes direct the direction of flow of information.   Ø   There are three types of transmission modes. They are: SIMPLEX Mode Ø   In this type of transmission mode, data can be sent only in one direction i.e. communication is unidirectional . We cannot send a message back to the sender. Ø   Unidirectional communication is done in Simplex Systems where we just need to send a command/signal, and do not expect any response back . Ø   Examples of simplex Mode are loudspeakers, television broadcasting,   keyboard and monitor etc. HALF DUPLEX Mode Ø   Half-duplex data transmission means that data can be transmitted in both directions on a signal carrier, but not at the same time. Ø   For example, in a local area network, one workstation can send data on the line and then immediately receive data o

Data Communication: Ø   Data communications is the exchange of data between two   or more devices via some form of transmission medium such as a wire cable or wireless media. Ø   The word data given, in whatever format refers to information presented, is agreed upon by the parties creating and using the data. Ø   When we communicate, we are actually sharing information . This sharing can be local or remote . Between people, local/native communication usually occurs face to face , whereas remote communication takes place over distance . Ø     For data communication network computers, telephone, wireless devices, and TV that are linked together in network are used.   COMPONENTS: A data communications system has five components . 1.     Message . The message is the information (data) to be sent. Data may be available in the form of text, numbers, pictures, audio, and video. 2.     Sender . The sender is the network device that sends the data