Bandwidth Requirement For Communication At Uni-Agric

 ABSTRACT

In communication, Bandwidth is used to measure communication. It is defined as the width of the range of the frequencies that an electronic signal uses. Bandwidth is expressed in terms of the difference between the signal having highest-frequency and the signal having the lowest-frequency

Bandwidth is a key concept in many telephony applications. In radio communications, for example, bandwidth is the frequency range occupied by a modulated carrier wave, whereas in optics it is the width of an individual spectral line or the entire spectral range.

In many signal processing contexts, bandwidth is a valuable and limited resource. For example, an FM radio receiver’s tuner spans a limited range of frequencies. A government agency may apportion the regionally available bandwidth to broadcast license holders so that their signals do not mutually interfere. Each transmitter owns a slice of bandwidth, the same thing occurs when communication occur in any school such as using fm transmitter to pass information to students in the same environment.

 CHAPTER ONE

1.1                                                        INTRODUCTION

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.

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 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.

However, for a communication to be complete it must operate according to a particular bandwidth. In communication, Bandwidth is used to measure electronic communication. It is defined as the width of the range of the frequencies that an electronic signal uses. Bandwidth is expressed in terms of the difference between the signal having highest-frequency and the signal having the lowest-frequency. In computer networks, bandwidth is often used as a term for the data transfer rate. More easily, the amount of data that is carried or passed from one point to another in a network, in a given time period.

1.2                                               OBJECTIVE OF THE STUDY

The aim of this work is highlight a particular bandwidth that can be used in communication system used in the school environment which is used to communicate with students in a particular environment.

1.3                                           SIGNIFICANCE OF THE STUDY

Bandwidth is often applied to the electromagnetic spectrum (e.g., radio waves, light waves and X-rays). Such waves are vibrations (oscillations) of electric and magnetic fields. To use a radio example, the lowest United States AM radio channel covers the band of frequencies from 535,000 Hz to 545,000 Hz. It therefore has a bandwidth of 10,000 Hz (545,000 – 535,000). All United States AM radio broadcasting stations have this bandwidth (though the location of each band is distinct). The lowest United States FM radio channel (on the other hand) covers the band from 88,000,000 Hz (88 MHz) to 88,200,000 Hz (88.2 MHz). It therefore has a bandwidth of 200,000 Hz. (Notice that the width of an FM band is 20 times the width of an AM band.)

The term “bandwidth” has been misused in the field of digital data communication. It is often incorrectly used to mean “data carrying capacity”. However, there is no such thing as “digital bandwidth”. The proper term for the data carrying capacity of a communication channel is channel capacity.

It is true that, in general, the channel capacity of a system increases with the bandwidth used for communication. However, many other effects are also important. Therefore, in many (if not most) real systems, the channel capacity is not easily related to the channel bandwidth.

1.4                       DIFFERENT TYPES OF COMMUNICATION SYSTEMS

Various types of communication are as below:

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.