Communication is the exchange of information through different mediums.

It is an activity that started even before the civilization of human beings; however, over a period of time, as technology advanced, accordingly different modes of communications also developed including telecommunication and wireless communication.

In today’s world, information and communication technology play an important role in almost every activity that we perform.

Types of Communication

Based on the advancement and mode of technology, telecommunication is categorized as −

• Telecommunication
• Wireless Communication

Let us now discuss each category −

Telecommunication

Telecommunication is a technique of transmission of information from one location to another by electromagnetic means.

Different types of information can be transferred through a telecommunication system, such as voice, text, pictures, etc.

Modern Telecommunication System

The modern form of telecommunication involves computer technology and it is capable of transferring wide range of data including audio, video, textual, many other computer files.

Major components of modern telecommunication are −

• Hardware − For example, computer system and modems.

• Software − This controls the Computer programs.

• Media − This is the communication outlet, wired or wireless.

• Networking − This technology connects various computer systems.

• Protocols − These rules govern information and communication transmission system.

Wireless Communication

Wireless communication is a technique of transmitting the information or power between two or more points, which are actually not connected with the physical wire/conductor.

The most common wireless technology uses ‘radio waves’. Microwave transmission is another technology.

The world’s first wireless telephone communication took place in 1880. This was experimented by Alexander Graham Bell and Charles Summer Tainter. Both of them together invented and patented the ‘photophone.’

Photophone was a sort of telephone, which conducted audio conversations wirelessly over modulated light beams, i.e., electromagnetic waves.

However, in the 21^st century, the invention of cellular phones radically changed the concept of communication system and made available the wireless communication system even in the remote part of the country.

Modulation

Modulation is one of the most significant processes through which characteristics of a carrier wave varies in accordance with an information signal.

In telecommunications, modulation is the process of transmitting a message signal inside another signal so that it can be physically transmitted. Likewise, modulation of a sine waveform transforms the narrow frequency range baseband message signal into the passband signal to pass through a filter.

Demodulation

Demodulation is the reverse process of modulation that change the signal and makes it understandable to the user.

Modulator

A modulator is a device that performs the modulation process.

Demodulator

Demodulator is a device that performs reverse modulation process or inverse of modulation.

Modem

Modem is device that performs both the process i.e. modulation and demodulation.

Types of Modulation

Let us now see what the different types of modulation are −

Analog Modulation

The waves continuously vary here and transfer signals; for example, audio signal, television signal, etc.

Digital Modulation

It remains in the form of discrete pulse, i.e., ‘on’ or ‘off.’ In this technology, all forms of data are used through binary digit, i.e., series of ‘0’ and ‘1.’

Methods of Modulation

In this section, we will see the different methods of modulation −

Amplitude modulation (AM)

In this method, the strength or intensity of the signal carrier varies. This represents that the data is being added to the signal.

Frequency modulation (FM)

In this modulation, the frequency of the carrier waveform varies; this reflects the frequency of the data.

Phase modulation (PM) − It is somehow similar to FM, but not the same.