What is a Communication System and Its Basic Elements

A “hello how are you” from one person, from one location, needs to be conveyed effectively and, clearly without noise to another person in another location. A picture sent to someone far away should be received without any distortion. A file transferred from one location to another location should be received without errors. Communication engineering is a process by which, connection (link) is established between two points, for information exchange maximizing customer delight. The main examples of the communication system include telephone, telegraph, mobile, Edison telegraph, computer and TV cable.  The sources of this system can be divided into electric otherwise non-electric. These are the sources of an input or message signal. The sources include audio files like mp3, mp4, MKV, and GIFs (graphic image files), human voice, e-mail messages, TV picture, and electromagnetic radiation.

What is a Telecommunication System?

Telecommunication implies communication between two points, separated by a distance. “Tele” means “at a distance”. It takes into account that something may be and will be lost in the process; hence the term ‘telecommunication’ includes all kinds of distances and all kinds of techniques such as radio, telegraphy, television, telephony, data communication, and computer networking.

Telecommunication System
Telecommunication System

We can define telecommunication as, communicating information such as data, text, pictures, voice, audio, video, feelings, thoughts over a long distance. The medium for such signal transmission can be thro electrical wire or cable (also known as “copper”), optical fiber or ether etc. If the communication is through the free-space by means of electromagnetic waves, then it is called wireless.

The Internet is the largest example of a typical data communication network. Few other forms of Telecom networks can be Corporate and academic wide-area networks (WANs). Different technologies have evolved, to bring out newer applications. Broadband and mobile Communications have instantly become popular. Some of the technologies in vogue are

  • Digital Telephone networks
  • Police wireless (Walkie talkie)
  • GSM / CDMA / UMTS / LTE / Wireless LAN
  • Facebook, Twitter, Linked In, WhatsApp

Distance does not matter anymore. Communication has to happen anytime, anywhere, at any place, through any medium, at any speed, through any device.

Basic Elements of Communication System

The basic elements of a communication system are shown in the elementary block diagram.

Basic Elements of Communication System
Basic Elements of Communication System


The objectives of a communication system include Minimum bandwidth, Maximum quality (Signal to Ratio), Minimum Bit Error Rate (BER), Maximum speed, Economy, Reliability, Mobility.


The message can be voice, music, Data, Video, Temperature, Light, Pressure etc

Input Transducer

The input can be in any energy form (temperature, pressure, light) but for transmission purposes, this needs to be converted to electrical energy. Transducer does this.


Translates the input signal to a higher frequency spectrum and also modulates (camouflages) the signal to combat noise (Amplitude Modulation, Freq Modulation, Phase Modulation, PCM, Delta Modulation, ASK, FSK, PSK, QPSK, QAM, GMSK, etc). The output can be analog or digital (thro A/D converters).


It converts information into a signal that is suitable for transmission over a medium. Transmitter increases the power of the signal thro power amplifiers and also provides interfaces to match the transmission medium, such as an antenna interface, fiber interface and so on.


If it is wireless communication, antenna propagates (radiates) the signal through the air (atmosphere)


A channel in a communication system just refers to the medium through which an electrical signal travels. These media are classified into two types such as guided as well as unguided. Guided media can be directed from a source in the direction of the receiver by using connecting cables. In OFC-optical fiber communication, an optical fiber is a medium. Additional guided media may comprise telephone wire, coaxial cable, and twisted pairs, etc.

The second type of media namely unguided media that refers to a communication channel which forms space among the source as well as the receiver. In RF communication, the medium is space which is called air. It is the only thing among the source & receiver whereas in further cases such as sonar, the medium is generally water since sound waves tour powerfully through assured liquid media. The two types of Medias are measured unguided for the reason that there are no connecting wires between the source as well as the receiver.


Noise is the challenge for communication engineers. It is random and unpredictable in nature. Noise is the undesirable electric energy that enters the communication system and interferes with the desired signal.

  • Noise is produced at the transmitter, channel and also at the receiver. Everywhere.
  • It can be man-made and natural.
  • Natural noise: Lightning, Solar radiation, Thermal
  • Man-made: Welding, Sparking, Motors, Car ignition, Tube lights, Electronic fan regulators etc


  • Receives the signal (desired) with noise (undesired).
  • Recovers the original signal in spite of the noise.
  • Consists of amplifiers, filters, mixers, oscillators, demodulators, transducers.
  • The receiver consists of a similar sequence of block diagrams.
  • Whatever was done in the transmitter will be undone in the receiver.
  • For example, modulation in TX will be matched by Demodulation in RX, A to D in TX will be undone by D to A in the receiver and so on.

Application Areas of Communication System

There are several types of communications which are used in different fields. The application areas of communication system mainly include the following.

 A strategic communications system is applicable for straight support of strategic forces. It is designed to meet up the necessities of changing strategic conditions as well as environmental conditions. It gives protectable communications like data, voice, video, between the mobile users to make possible. Generally, requires very short fitting times, typically on the hours of order, in order to gather the necessities of common replacement.

An Emergency communication system is normally based on the computer that is mainly used for the two-way communication of urgent situation of sending messages between two persons & groups of persons. The main intention of these systems to combine the cross-communication of messages among is different communication technologies.

An ACD or Automatic call distributor is one kind of communication system that routinely assigns, queues, as well as unites callers in the direction of handlers. Main applications of this system involved in customer service, placing an order by telephone, otherwise management services.

A VCCS or Voice Communication Control System is basically an automatic call distributor with characteristics that make to utilize in dangerous situations.

Thus, this is all about the basic elements of the communication system, and the key components of this system mainly include sources, input transducers, transmitter, communication channel receiver, and the output transducer. Here is a question for you, what are the different types of communication systems?