A thought kept in the brain is of no use unless and until it is shared with other individuals and rest of the world. The idea, no matter however brilliant it is, must come out for its successful implementation for it to benefit one and all. It is the prime responsibility of the individual to share his thoughts and ideas with others.

How is it possible? How can one share his ideas and thoughts?

The communication system enables the successful transmission of idea or any other important information among individuals.

The person from whom the thought originates carefully encodes his ideas into a sensible content which is now ready to be shared with everyone. He/She is commonly referred to as the sender and the other party who receives the information from him is called the receiver or the recipient. The free flow of information between the sender and the receiver takes place because of the communication system.

The flow of information can be between two individuals. The information can flow from the individual to a machine, from the machine to the individual and even between two machines.

Machines coupled together through networks also provide signals for the individuals to respond, thus a type of communication system. In the above cases all the machines must work on similar lines and patterns, must be technically compatible and has to provide the same information, so that the individuals can decode the information well.

Let us study the various types of communication system for the smooth flow of information between two parties.

1. Optical Communication System

   The word “Optical” stands for light. As the name itself suggests, optical communication system depends on light as the medium for communication.

   In an optical communication system the transmitter converts the information into an optical signal (signal in the form of light) and finally the signal then reaches the recipient. The recipient then decodes the signal and responds accordingly.

   In optical communication system, light helps in the transmission of information. The safe landing of helicopters and aeroplanes work on the above principle. The pilots receive light signals from the base and decide their next movements. On the roads, red light communicates the individual to immediately stop while the individual moves on seeing the green light.

   In this mode of communication light travels through the optical fibre.

2. Radio Communication System

   In the radio communication system the information flows with the help of a radio. Radio communication system works with the aid of a transmitter and a receiver both equipped with an antenna.

   The transmitter with the help of an antenna produces signals which are carried through radio carrier wave. The receiver also with the help of an antenna receives the signal. Some information is unwanted and must be discarded and hence the electronic filters help in the separation of radio signals from other unwanted signals which are further amplified to an optimum level.

   Finally the signals are decoded in an information which can be easily understood by the individuals for them to respond accordingly.

3. Duplex communications system

   In Duplex communications system two equipments can communicate with each other in both the directions simultaneously and hence the name Duplex. When you interact with your friend over the telephone, both of you can listen to each other at the same time.

   The sender sends the signals to the receiver who receives it then and there and also give his valuable feedback to the speaker for him to respond. Hence the communication actually takes place between the speaker and the receiver simultaneously.

   In the Duplex communication system, two devices can communicate with each other at the same time.

   A type of communication system involves the sender and the receiver where the sender is in charge of sending signals and the recipients only listen to it and respond accordingly. Such communication is also called Simplex communication system.

4. Half Duplex Communication System

   In half Duplex communication system, both the two parties can’t communicate simultaneously. The sender has to stop sending the signals to the recipient and then only the recipient can respond.

   A walkie talkie works on the half duplex communication system. The military personnel while interacting has to say “Over” for the other person to respond. He needs to speak the security code correctly for the other person to speak. The other party will never communicate unless and until the code is correct and complete.

5. Tactical Communication System

   Another mode of communication is the tactical mode of communication. In this mode of communication, communication varies according to the changes in the environmental conditions and other situations.

All the above modes of communication work for a common objective ie to transfer the information from one party to the other party. The various models of communication system help us to understand the route of flow of information from the sender to the recipients through some medium.