1. Introduction to Telecommunications

2. Topics to be discussed Definition History Importance Modes Components
Concepts
Topologies

3. Telecommunications Telecommunications
Consists of a set of hardware and software
Transmits voice, graphics, images and video as well as data
Types –
Wired
Wireless

4. History Telegraph Telephone Computer Transistor
Large-Scale Integrated Circuits
Satellite

5. Importance Melding of information systems and telecommunication
Information at right time and right place
Capturing instant business transaction data
Allowing geographic dispersion of facilities and people
Internet marketing

6. Internet Revolution
WWW: inquiry sources of information via graphical browser software
electronic mail
Usenet: place messages on bulletin board
IRC: real time dialogs
FTP: file transfer
Telnet: login on other systems
Other: telephone, video conferencing, ...

7. Different modes Data communication Voice communication
Video communication
Multimedia communication

8. Telecommunication Components
Channels and Media
Telecommunications
software
Telecom
processors
Telecom
processors
End-user
workstation
Computers

9. Telecommunication Components
Terminals
terminal, office equipment , telephones , ...
Telecommunications processors
modems, multiplexers, front-end processors, ...
Telecommunications channels and media
copper wires, coaxial cables, fiber optic cables, satellites, ...
Computers
host computers, front-end computers, network servers, ...
Telecommunications control software
telecommunication monitors, network operating systems, …

10. Transmission Concepts..
Simplex - Data can flow in only one direction. Radio, TV, computer to printers, public address systems or any other unidirectional transmission.
Half-Duplex - Data flows in only one direction at a time. CB radio is half-duplex.
Full Duplex - Data flows in both directions at the same time.

11. Transmission Concepts
Parallel:
All data lines (normally 8) are connected between devices
Transmission between computers or between a computer and a printer.
Fast, requires more wires and unsuited for long distances.
Serial:
Bit-by-bit transmission in serial or sequential fashion over a single wire.
Used in PC’s serial port as well as on local area networks.
Slow, but can travel longer distances and is widely used.

12. Network topologies Star Bus Ring
all communications go via the central system
Bus
can easily be extended at the ends
Ring
more secure

13. Star network - Efficient , also for high speeds
With direct
connections
Point-to-point lines
- Efficient , also for high speeds
- With a large number of workstations cabling might be a problem

14. Bus network - more complex hardware - simpler cabling system
Shared usage of a
broadband network
Multidrop lines
- more complex hardware
- simpler cabling system

15. Ring Networks
Ring Network
- more equal basis