Communication System with its basic elements and mode

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Introduction of Communication System 

The fundamental purpose of a communications system is the exchange of data between two parties. Below figure presents one particular example, which is communication between a workstation and a server over a public telephone network. Another example is the exchange of voice signals between two telephones over the same network. 

Some basic element of communication system are given bellow

• Source : This device generates the data to be transmitted; examples are telephones and personal computers.
• Transmitter : Usually, the data generated by a source system are not transmitted directly in the form in which they were generated. Rather, a transmitter transforms and encodes the information in such a way as to produce electromagnetic signals that can be transmitted across some sort of transmission system. For example, a modem takes a digital bit stream from an attached device such as a personal computer and transforms that bit stream into an analog signal that can be handled by the telephone network.
• Transmission system : This can be a single transmission line or a complex network connecting source and destination.
• Receiver : The receiver accepts the signal from the transmission system and converts it into a form that can be handled by the destination device. For example, a modem will accept an analog signal coming from a network or transmission line and convert it into a digital bit stream. 
• Destination : Takes the incoming data from the receiver. 

Generic Communication Model 

A generic communication model has five components: 

• Message : The message is the information (data) to be communicated. Popular forms of information include text, numbers, pictures, audio, and video.
• Sender : The sender is the device that sends the data message. It can be a computer, workstation, telephone handset, video camera, and so on. 
• Receiver : The receiver is the device that receives the message. It can be a computer, workstation, telephone handset, television, and so on. 
• Transmission medium : The transmission medium is the physical path by which a message travels from sender to receiver. Some examples of transmission media include twisted-pair wire, coaxial cable, fiber-optic cable, and radio waves. 
• Protocol : A protocol is a set of rules that govern data communications. It represents an agreement between the communicating devices. Without a protocol, two devices may be connected but not communicating, just as a person speaking French cannot be understood by a person who speaks only Japanese.