Communication means sending, receiving and processing of information between two or more devices. A collection of elements (devices) which works together to establish a communication between the sender and receiver is called a communication system. Some examples of communication system include radio broadcasting, television broadcasting, radio telegraphy, mobile communication, computer communication etc.Two or more people communicating with each other by using sound signals is also known as the communication system.
Block Diagram of Communication system
The basic components of a communication system are information source, input transducer, transmitter, communication channel, receiver, output transducer, and destination.
Information Source
As we know that the communication system establishes the communication bridge between the sender (transmitter) and receiver. To establish this communication bridge between the sender and receiver, first, we need an information to send. This information originates in the information source.
The information generated by the source may be in the form of sound (human speech), picture (image source), words (plain text in some particular language such as English, French, German etc.)
For example, if you are talking with your friend on a phone, you are considered as the information source who generates information in the form of sound.
For beginners to analog communication, it’s important to understand the difference between message and information. The message is the part of a communication which involves sending information from source to destination. Information is a meaningful data that the receiver consumes.
Input Transducer
If you want to talk (communicate) with your friend who is sitting beside you, then you can directly talk with him by using voice signals (sound signals). But if the same friend is farther away from you, then you can’t directly communicate with him by using voice signals (sound signals) because sound signals cannot travel larger distances. So in order to overcome this problem and transmit information to larger distances, first we need to convert this sound signal into another form of signal (electrical signal or light signal) which travel larger distances. The device which is used to convert this sound signal into another form of signal is called transducer.
A transducer is a device which converts one form of energy or signal into another form of energy or signal. The transducer is present at the input side and output side of the communication system. The transducer that is present at the input side of the communication system is called input transducer. Generally, the input transducer converts the non-electrical signal (sound signal or light signal) into an electrical signal. The best example of an input transducer is the microphone which is placed between the information source and the transmitter section. A microphone is a device which converts your voice signals (sound signals) into electrical signals.
Transmitter
The transmitter is a device which converts the signal produced by the source into a form that is suitable for transmission over a given channel or medium. Transmitters use a technique called modulation to convert the electrical signal into a form that is suitable for transmission over a given channel or medium. Modulation is the main function of a transmitter.
When we send the signal to larger distances, it undergoes various circ*mstances which makes the signal weak. In order to send the signals to larger distances, without the effect of any external interferences or noise addition and without getting faded away, it has to undergo a process called modulation. Modulation increases the strength of a signal without changing the parameters of the original signal. Thus the resulted signal overcomes the various effects which make it to become weak.
Communication Channel
The communication channel is a medium through which the signal travels.
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The communication channel is a wired or wireless medium through which the signal (information) travels from source (transmitter) to destination (receiver).
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The communication channel is a wired or wireless medium that is used to send the signal from the source (transmitter) to the destination (receiver).
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The communication channel is a wired or wireless medium that connects the transmitter and receiver for sending the signal.
Communication channels are divided into two categories: wired and wireless. Some examples of wired channels include co-axial cables, fiber optic cables, and twisted pair telephone lines. Examples of wireless channels are air, water, and vacuum.
Although channel provides a way for communication, it has one drawback. The communication channel reduces the signal strength (attenuates the signal) that carries the information. This reduction in signal strength is mainly caused by the addition of external noise, physical surroundings, and travel distance.Thus the signal received by the receiver is very weak. To compensate this signal loss, amplifiers (the device that amplifies the signal strength) are used at both the transmitter and the receiver side.
Noise
Noise is an unwanted signal that enters the communication system via the communication channel and interferes with the transmitted signal. The noise signal (unwanted signal) degrades the transmitted signal (signal containing information).
Receiver
The receiver is a device that receives the signal (electrical signal) from the channel and converts the signal (electrical signal) back to its original form (light and sound) which is understandable by humans at the destination. TV set is a good example of a receiver. TV set receives the signals sent by the TV transmitting stations and converts the signal into a form which is easily understandable by the humans who are watching TV.
Output Transducer
The transducer that is present at the output side of the communication system is called output transducer. Generally, the output transducer converts the electrical signal into a non-electrical signal (sound signal, light signal, or both sound and light signal). The best example of an output transducer is the loudspeaker which is placed between the receiver section and the destination. The loudspeaker converts the electrical signals into sound signals which are easily understandable by the humans at the destination.
Destination
The destination is the final stage in the communication system. Generally, humans at some place are considered as the destination. A destination is a place where humans consume the information. For example, if you are watching TV, you are considered as the destination.
