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(a) What is meant by Simplex?
(b) What is half-duplex mode? Give one example.
(c) Why and when do we use Fiber Optic for communication?

(a) Simplex Mode
In simplex mode, data can flow only in one direction. It cannot be moved in both directions. It operates in a manner similar to one-way street. The direction of flow never changes. A device with simplex mode can either send or receive data. It cannot perform both actions. An example is a traditional television broadcast. The signal is sent from the transmitter to TV antenna. There is no return signal.

(b) Half-Duplex Mode
In half-duplex mode, data can flow in both directions but not at the same time. It is transmitted one-way at one time. A device with half-duplex mode can send or receive data but not at the same time. That is why the speed of half-duplex mode is slow. Internet surfing is an example of half-duplex communication. The user issues a request for a web page. The webpage is downloaded and displayed before issuing another request.

(c) Because Fiber Optic cable is very fast communication media. It consists of hundreds or thousands of thin strands (threads) of glass or plastic. The fiber optic cable transmits data in the form of light waves. An important characteristic of fiber optic is refraction. Fiber optic cable provides high quality transmission at very high speed usually 1Gbps to 2Gbps. Fiber optic transmission is not affected by electromagnetic waves. Many telephone and cable TV companies are using fiber optic cables. And very soon , all communication system will use fiber optic cables.