Communication Technology - Library and Information Science - Devi ...

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Use the modern technology for communicate the information ... Communication Technology because in the very short time we ... History of Tele-communication.
Communication Technology By Bhupendra Ratha, Lecturer School of Library and Information Science Devi Ahilya University, Indore Email: [email protected]

What is the Communication? A word communication has been drives from the Latin word “Communicare” which means to communicate, the word used for exchange the information. Communication needs languages as the channel for communication between two or more than two person.

Basic requirements and Process of a good communication Language Sender Message

Receiver

Channel

Channels of communications Body language  Oral communication  Verbal communication  Audio Audio--visual communication  Mass communication  Tele Tele--communication  Wireless communication 

Types of communications 

One to one communication



Centralized communication



Circular communication



Free flow communication

One to One Hy, Raj How are you

Fine, I hope you also fine

Centralized communication

Circular communication

Free--Flow communication Free

Communication Technology 

Use the modern technology for communicate the information by different channels and medias are called communication technology such as electronic telegraph, telephone, radio, TV, computer, wireless and networking etc.

Tele--communication Tele Tele-communication is the part of Information and TeleCommunication Technology because in the very short time we can get information at the international level. It is the process of exchange the information to longlong-distance

Characteristics of TeleTele-communication Any one can use the TeleTele-communication technology for exchange the information.  The message may be send in coding language which understand only sender and receiver.  Information are easily exchange in the different format such as text, numerical, graphical, audioaudio-visual etc. 

Cont… It can exchange information globally or each and every area of the world.  Save the time, money and human power.  It make the privacy of message. 

History of TeleTele-communication 

3000 BC

Smoke signals, Drums, Pigeon etc.



490 BC

Heliographs



1837 AD Telegraph by Samuals F B Morse



1876 AD Telephone by Allexander Grahmbell

Cont… 

1894 AD Radio by Marconi



1926 AD T. V. by J. L. Baird



1963 AD Audio tape by Phillips com.



1969 AD Internet by ARPANET

Cont… 

1977 Fiber optical telephone cable.



1980



1981 Walkman by Sony comp.



1990

WWW by Terner Lee

html

Tele--communication media Tele Bounded/Cable media

Boundless/Wireless Media

Coaxial Cable

Radio Wave

Twisted-Pair Cable

Microwave

Fiber-Optical Cable

Satellite

Bounded/Cable Media 

When connect the telecommunication component with the cable and exchange the information they call bounded/cable media.



There are three types of cable media very commonly used and they are; 1. Coaxial Cable 2. TwistedTwisted-Pair Cable 3. FiberFiber-Optic Cable

Coaxial Cable 

Coaxial cable gets its name because two conductors share a common axis; the cable is most frequently referred to “coax”. A type of coaxial cable that we may be familiar with is our television cable. Its components are as follows;



A center conductor An outer conductor An insulation layer A plastic encasement (Jacket)

  

A Center conductor 

A center conductor, although usually solid copper wire is sometimes made of standard wire.

A outer conductor 

A outer conductor forms a tube surrounding the center conductor. This conductor can consist of braided wires, metallic foil or both. The outer conductor, frequently called the shield, serves as a ground and also protects the inner conductor from EMI.

An insulation layer 

An insulation layer keeps the outer conductor space evenly from the center conductor.

A plastic encasement (Jacket) 

A plastic encasement protects the cable from damage.

Classification of Coaxial Cable



Thinnet ::- 0.25 inch (6mm) 610 feet



Thicknet ::- 0.50 inch (13mm) 1650 feet

Twisted--Pair Cable Twisted 

Twisted pair cable is popular very much because of its inexpensiveness and ease of installation. A basic twisted pair cable consists of two strands of copper wire twisted together. The twisting reduces the tendency of the cable to radiate radio frequency noise that interferes with nearby cables and electronic components, because the radiated signals from the twisted wires tend to cancel each other out.

Classification of TPC 

Shielded TwistedTwisted-Pair Cable (STPC)



Unshielded TwistedTwisted-Pair Cable (UTPC)

Shielded TwistedTwisted-Pair Cable (STPC) 

Shielded TwistedTwisted-Pair Cabling consists of one or more twistedtwisted-pair of cables enclosed in a foil wrap and woven copper shielding. Early LAN designer used STPC because the shield performed double duty, reducing the tendancy of the cable to radiate EMI and reducing the cables sensitivity to outside interference

Unshielded TwistedTwisted-Pair Cable (UTPC) 

UTPC doesn’t incorporate a braided shield into its structure. However characteristics of UTPC are similar in many ways to STPC, differing primarily in EMI.

Fiber--Optical Cable Fiber 

The center conductor of a fiberfiber-optic cable is a fiber that consist of highly refined glass or plastic designed to transmit light signals with little loss.



A glass core supports a longer cabling distance, but a plastic core is typically easier to work with.



The fiber is coated with a cladding that reflects signals back into the fiber to reduce signal loss. A plastic sheath protects the fiber.

Cont… 

Fiber optic network cable consist of two strands separately enclosed in plastic sheaths. One strands sends and the other receivers.



Two types of cable configurations are available; 1. Loose configurations. 2. Light configurations.

Loose configurations 

Loose configurations incorporate a space between the fiber and the plastic encasement, this space is filled with a gel or other material.

Tight Configurations



Tight configurations contain strength wires between the conductor and the outer plastic encasement.

Comparison of cable media Cable type

Cost

Installation

Capacity

Range

Coaxial

Less than TPC

Inexpensive / easy

10 mbps

500 m

Twisted Pair

Lowest

Fairly easy

100 mbps

100 m

Fiber--Optic Fiber

Highest

Expensive / Difficult

100mbps to above

10 km

Boundless/Wireless Media 

When the information transmission without cable media they are called boundless/wireless media.



There are many types of wireless media ; 1. Radio wave 2. Microwave 3. Satellite

Radio wave 

In radio transmission a radiating antenna is used to convert a timetime-varying electric current into an electromagnetic wave, which freely propagates through a no conducting medium such as air or space. In a broadcast radio channel, an omnidirectional antenna radiates a transmitted signal over a wide service area.

Microwave 

Microwave is the most important media of telecommunications. The transmission path of microwave links can be established between two landland-based antennas or tower.

Satellite 

In 1954 the satellite technique has established. It is also most important media of telecommunication. Easily and authentic data transmission by this media. Most telecommunication satellite have been placed in Geostationary Orbit (GEO), a circular orbit 35,785 km above the earth.

Modes of Telecommunications Serial and parallel  Simplex, Half duplex and full duplex  Modulation Modulation--demodulation  Radio wave  Microwave  Satellite wave 

Serial and parallel In serial communication, only one bit transmitted at a time and it is the suited for slow and long distance communication, whereas in parallel transmission group of bits as transmitted at a time, which is suited for high speed and short distance communication. 

Simplex, Half duplex, Full duplex Television

Simplex

Half duplex

Or

Computer

Full duplex

and

Computer

Modulation--demodulation Modulation

Analog Input

A/D Converter (Modulation)

Digital Signals

Digital Input Signals

D/A Converter (Demodulation)

Digital Input Signals

Analog Output

Mode of Radio wave communication

Electronic signal

Master Station

Electromagnetic signals

Mode of Microwave communication Transmitter

Repeater Receiver Output signals

Input signals

Atmospheric signals (Air and Surface)

Master Station

Mode of Satellite Wave Communication Output signals

Satellite

Input signals Master Station

Master Station

Component of Telecommunication  1. 2. 3. 4. 5.

The basic components are follows; Sender/Transmitter Message Language Media Receiver

Other Component of Telecommunication Modem  Repeater  Hub  Bridge  Router  Switch  Brouter  Gateway 

Modem MODEM is contraction of Modulator/ Demodulator, which allows a computer to transmit the information over a telephone line to another computer.  The modem converts the digital signals into analog signals and analog signals to digital signals. 

Repeater A networking component that extends a network by boosting the signal so that it can travel farther along the cabling.  A repeater is a form of digital amplifier that works at the physical layer of OSI mode for regenerate of signals. 

Hub Hub is also called wiring concentrators, provide a central attachment point for network cabling.  Hubs can be divided in three categories; 1. Passive Hub 2. Active Hub 3. Intelligent Hub 

Bridge A network component used either to extend or to segment networks. Bridges work at the OSI data link layer. They can be used both to join dissimilar media.  Bridges come in three basic types; 1. Local bridges 2. Remote bridges 3. Wireless bridges 

Router 

Router works at the network layer of OSI model for networking to move packets between using their logical addresses are the destination host.

Switch 

Bridge with more efficiency is called switch. A switch may act as a multimulti-bridge to connect devices in a LAN. Switch has a buffer for each link to which it is connected.

Brouter 

Any network device having the capabilities of both a bridge and a router. Usually, a brouter will act as a router for one protocol and a bridge for all other protocols. Brouters are not common in network.

Gateway 

Gateway is used to connect the different protocol based networks (like TCP/IP, Apple Talk etc,) A term for a broad category of network components that allow communication between different networking architectures and different protocols. Gateways generally operate at the higher levels of the Open Systems Interconnection.