1. Communication Technology
Dr. S. L. Sangam
Professor and Chairman
Department of Library of Information Science
Karnatak University Dharwad

2. Introduction
Communication technology focuses on transmission technology
Transmits message from one place to another place
Telecommunication is
Tele =distance
to over come-----space, time distance
“The main purpose of telecommunication is to transmit representation on information (signal) between remote location”
“Telecommunication is the transmission of data over a network by means of an electrical or optical channel”

3. Meaning of Communication
The word communication has been derived from the Latin word “communis” which means “to make common”, ‘to share’, ‘to impact’, ‘to transmit’ ,make common, impart or transmit ideas, information or knowledge etc
Communication means the transfer of messages from the communicator to the receiver. Communication is basically the science of sharing ideas, views, thoughts, expressions etc., through some media. It makes individual interaction possible and comprehensive

4. Developments in Communication
In the prehistoric the men used only various sounds and language development was not seen. Later he developed writing skills dates back to 3000 B.C and used clay tablets. Chinese invented paper and were first to develop ink in 220 A.D Modern alphabets were developed in 64 B.C
Communication acquired great momentum with the invention of printing machine by ‘John Guttenberg’
Later ‘Samuel Morse’ introduce Telegraph-1835
In 1876 ‘Alexander Graham Bell’ introduced Telephone
In 1920 ‘Marconi’ introduced Radio
In ‘J.L.Baird’ introduced TV
In 1942 the Electronic computer came into existances.

5. Cont..
The latest development involves the internet, satellite communication, they have condensed the whole world into a village in which we can communicate to a person anywhere in the world any time

6. Telecommunication Technology
Telecommunication is communication at a distance. It encompasses all forms of communication and includes communicatio by voice,video and data.
Tele communication signals carry the voice,video and data that are to transmitted from one point to another.
It is based upon the transmission of electromagnetric signals, which can be
Radio waves travelling through the air or through space.
Electrical currents flowing along a wire,either twisted pairs of wires(as in many telephone circuits) or a coaxial cables(as in a TV aerial cable)
Laser pulses travelling along optic fibres.

7. Fundamentals of Telecommunications
Source producing message
Why Modulator ?
To ease of radiation
To reduce noise
For frequency assignment.
Input Data
IIiiiiiii
Transmitor
Modulator

8. Telecommunication Splits into two major divisions
Radio and T V
Which are mainly intended for audio and video broadcasts
Communicating computer data,for instance by satelitelink
Telephone networks,
Originally designed for voice,but now also used send data telex and image,using facsimile
In both cases there are there are three process

9. Conti.. The conversion of information i.e -data - text
-image or voice to Electromagnetic signals.
The transmission of these signals over a distance to a receiver.
Conversion of signals back to information data,text,image or voice.

10. Data Communication Through Telecommunication
Telegraph
Telephone -1876
Long Distance communication
Satellite communication -1965

11. Telefacsimile Technology
Transmission of a fixed images an electric signals over communication channel
Telefacsimile Technology includes:
Telegraph
Telephone
Radio
Telex
Fax
Faxmile
It involves 3 process Scanning,Recording,Transmission

12. Components of Communication Process
Sender- originator of message
Receiver-The Recipient of the message
Message-The information which is transferred
Medium- The path or means by which the message travels

13. Characteristics of Data Transmission
Method of data transmission
Serial transmission:
One bit is transmitted at a time
Parallel transmission:
Several bits are sent all at once over different wires. It is faster
Synchronous transmission:
Each data byte has “start and stop” signals placed around it. To alert the receiver that data is arriving
Asynchronous transmission:
Bits are transmitted at a specific time intervals. In this method the sender must coordinate with the receiver before sending data.

14. Cont.. Direction of Communication
Depending on direction of transmission, data communication can be classified as
Simplex: Data transmission is in one direction only
Full- duplex: Transfers data in both direction. It requires two independent channels one for each direction.
Half-duplex: transmission occurs in both direction but only in one direction at a time. It requires less hardware

15. cont. 9.6 kbps 64 kbps 128 kbps 256kbps 512 kbps 1mbps 2mpbs
Speed of data tansmission
The rate at which data can be transmitted is measured in terms of bits per second or bps
9.6 kbps
64 kbps
128 kbps
256kbps
512 kbps
1mbps
2mpbs

16. Signals
In tellecommunication message are transmitted as signals over a medium
A signal is an acoustic (sound),light,electric or electromagnetic representation of data being transferred.There are two types:
Analog Signals:
Analog signals is the sound produced by the human voice.telephone channels,for instance carry analog signals.
Digital Signals:
Transmit information in binary code i.e 1 or 0. these signals are of fixed length or duration.

17. Medias of Communication
Wires
Cables
Modem
Twisted pair
Coaxial Cables
Optical Fiber
Satellite Communication
Wireless transmission
Ethernet
VSAT(Very Small Architecture terminal)
Bandwidth
ISDN
Cellular mobile technology (cell phone)

18. Services of Telecommunication
Telephone
Telex
Teletext
Facsimile
Electronic Mail
Videotext
Bulletin Boards
Online Databases
Video Phone and Video Conferencing

19. Problems of Telecommunication
The fundamental problems faced by communication technology are
Signal-strength
Noise
Bandwidth

20. Wireless Transmission
This requires no physical connection.It send signals through air or space. There are four types:
Cordless telephone
Microwave
Satellite transmission
Communication Satellites

21. Satellite Telecommunication
Devices that orbits the earth receiving processing and transmitting signals or generating images or data to be transmitted back to earth,such as weather,picture.
Communication Satellite:
Satellite that relays radio or TV signals from one point to the earth’s surface to another .
Satellite Network:
Series satellite which provide wide coverage of an area and Small systems that is a part of a larger system.
Satellite Computer:
Computer doing various tasks under the control of another computer
Satellite Terminal:
Computer terminal that is outside the main network.

22. INSAT
Introduction of Satellite telecommunication on an operational basis in India virual revolution in the field of telecommunication.
INSAT -1B is able to provide a wide variety of services tthey are:
Data Network
News Collection and Dissemination
High Speed Facsimile
Teleconferencing

23. VSAT (Very Small Aperture Terminals)
VSATs are very small and expensive terminals capable of being mounted directly on customers premises, thereby providing a direct communication between a central point and large number of remote points
The services provided are. IP
Based Wan Network Services 
Service
Interface with Telephone PBX
Mobile VSAT Communications System

24. Conti.. Data and Voice Connectivity Fax Video
Installation, Moving And Set-up Services
Broadcast Services
Contract Installation and Service on VSAT Networks
Real-Time Data Acquisition and Broadcast

25. Ethernet
It is popular network architecture for Local Area Network. It is available in three different speed
10 mpbs, 100 mpbs mpbs/1gbps which is an emerging standard
It is base band networking technology that sends its signals serially one bit a time.
It operates in half-duplex mode, in which a station can either transmit/receive but cannot do both.
Each station listens to the network and transmits data only if no other stations are using the network.
Operates on the first-come, first-served basis. Transmits over wires in frames. Minimum size is 64 bytes maximum 15/8 bytes.

26. Ethernet network

27. Integrated Services Digital Network(ISDN)
ISDN is a network providing end digital connectivity.
Offers a wide range of user services with limited set of user network interfaces.
The services of ISDN are :
Voice
Telephone with multiple buttons for instant call-set up to arbitrary telephone any where in the world.
It allows the telephone on a display the caller’s number, name and address on display while rigging.
Conference call world wide
Non Voice services are

28. cont. remote electricity meter reading Online medical burglar
Smoke alarm
Automatically call the hospital, police and fire department

29. ISDN SYSTEM

30. Cellular Mobile Technology
A cell phone commonly called as mobile phone system is basically ‘ radio transmitter’s that broadcast a signal to a receiver in imaginary hexagonal geographical area called “ cell”
Each cell element contains a Tran’s receiver called a “Base trans receiver station” or BTS, and this is connected to BSC through a cable which acts like a controller.
When a call is made or received by a mobile station, the BSC allocates the available frequencies from BTS to it, thus connecting the telephones to the system.
Thus they cover a vast geographical area and provide a large number of connections.
Therefore Cell phone can be used in communication with telephone around the world.

31. Conclusion
Communication is process of involving the sorting, selecting and sending of symbols in such a way as to help the listener perceive and recreate in his own mind the meaning contained in the mind of communicator and therefore telecommunication is such a technology which encompasses all forms of communication medias which can easily reach the people every effectively.