Transcript Special Tutorial on Telecommunications Fundamentals

EEE402F-b / EEE526Z
Convergent Networks
Special Tutorial on Telecommunications
H Anthony Chan
[email protected]
http://www.eng.uct.ac.za/~achan
Mqhele E Dlodlo
[email protected]
http://www.uct.ac.za/courses/eee_mdlodlo/
Department of Electrical Engineering
University of Cape Town
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015
Aims
 To review the Basic Principles of Telecommunications
 To outline necessary background knowledge for higher level
systems analysis, design, selection and management
 To identify critical systems characteristics
 To identify telecommunication systems as:
 Radio Systems
 Data Systems, and
 Television Systems
 To outline a sample of Business Services offered by
Telecommunication Systems
 To cite some strategic issues facing telecommunication
systems
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015
Objectives
To demonstrate an understanding of the
place of data communications in
telecommunication systems
To show an appreciation of the ubiquity of
telecommunications in today’s society
To show an ability to identify and explain
system characteristics
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015
Telecommunication
 The extension of communication over a distance,
under the practical constraints of attenuation, noise
and interference such that something may be lost
in the process; hence the term 'telecommunication'
covers all forms of distance and/or conversion of
the original communications, like
 radio,
 telegraphy,
 television,
 telephony,
 data communication and
 computer networking.
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015
Telecommunication Systems
 A telecommunication system receives and converts some
original information energy (voice, music, video, data) into
an electronic information signal, transmits the signal and
converts the signal at the destination back to its desired
form. No live transfer!
 Examples include:
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Telephone networks
Data communication networks
Computer networks
Broadcast networks – radio and television
 Main Types:
 Line systems
 Radio systems
 Satellite-based systems
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015
Elementary Concepts – Wire-line
A line system passes the electronic
information signal down a wire, cable or fibre
link (or a combination of these)
The propagation speed can be as low as
60% the speed of light in some media.
A source encoder converts analogue
information into a Pulse Code Modulated
(PCM) signal before transmission
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015
Elementary Concepts - Wireless
 In a radio system, the source converts the energy
into an electromagnetic radio signal to transmit
over a radio link
 The propagation proceeds at the speed of light
 In either case, there will be signal degradation due
to electronic noise and other mechanisms
 The objective of systems design is to minimise
such distortions
 Interactive telecommunication systems require twoway or duplex channels, but broadcast systems
need only simplex or one-way channels
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015
Line System Characteristics
Attenuation and Noise
Modulation: AM, FM, PM, PCM
Twisted pair copper wires
Coaxial cable or tube
Optical fibre
Transmission line characteristics
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015
Wireless System Characteristics
 Electromagnetic radio waves:
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Surface wave
Sky wave (via ionosphere)
Space wave (line-of-sight and reflected)
Satellite transponder radiation
Tropospheric scatter
Electromagnetic light waves (pulsed infra red laser light)
Propagation
Antenna design
Satellite link design
Land-mobile access network design
Maritime communication systems design
Error-control coding
Multiple access control schemes
Detection schemes, e.g. joint detection
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015
Data Networks and Systems
Open Systems Interconnection Model
Internetworking Model
Data services and packet switching
Frame mode bearer services
Local area networks (LANs)
Wide area networks (WANs)
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015
Signalling, Transmission and Switching
 Signalling: passing of information from one point to another
for setting up or supervision of a telephone call or a data
exchange session
 Transmission: dispatch and propagation of a signal,
message, or other form of information by any means, such
as by telegraph, telephone, radio, television, or facsimile via
any medium, such as wire, coaxial cable, microwave, optical
fibre, or radio frequency.
 Switching: the process of making connections and relaying
information between a calling party and a called party
usually through a combination of space and time division
multiplex apparatus in the exchange fabric
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015
ITU-T Signalling System No. 7
Is extended to data and multimedia control
Separates signalling and user traffic
Provides better support for services like:
network management
Network maintenance
Centralised call accounting
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015
Transmission
 The central problem of transmission is the conveyance of signals as
waves over distances significant with respect to the wavelengths
involved
 Large volumes of data are regularly transmitted sequentially making it
necessary to encode the information into a signal
 A travelling sinusoidal wave progressively experiences increased phase
delay and attenuation with distance in the direction of propagation
 The main characteristics of transmission media are the propagation
constant, characteristic impedance and reflection coefficient
 Transmission media include twisted copper wire pairs, coaxial cables,
strip lines, waveguides, optical fibre and free space
 Transmission system design and analysis relies greatly on
electromagnetic theory as well as differential and integral calculus
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015
Switching Principles
 Goal: to enable any terminal (telephone, data terminal,
computer) as requested by the calling party
 Switching centre – telephone exchange
 Full mesh – backbone or core networks
 Digital switching – time division stages shift PCM words in
time between incoming and outgoing channels, multiplexing
them onto different time slots
 Space division – provides direct physical paths right through
the exchange connecting the local loops of one subscriber
to that of another.
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015
Evolving Core Switching Technologies
Frame Relay (FR)
Asynchronous Transfer Mode (ATM)
Internet Protocol (IP)
IP Virtual Private Network (IP VPN)
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015
Business Services
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Private Automatic Branch Exchange, key-phones, Centrex
Virtual Private Networks (VPN)
Private networks and leased lines
Conference calling
ISDN supplementary services
Mobile telecommunication systems – paging, SMS, voice,
remote login, email, Internet access
Free-phones – “0800” series
Facsimile
Interactive services – teletex, teletext, email, EFT-POS,
credit cards, smart cards, voice mail
Voice over IP
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015
Personal Consumer Services
 Television Services
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 High Definition Television (HDTV)
 Direct Satellite Television (DSTV/DBS)
 Cable Television
Asynchronous Digital Subscriber Line (ADSL) and variants
Wireless Local Loop
Dial-up Email or Internet Access
Telephone Banking
Internet Banking
Automatic Teller Machines
Phone Cards
Emergency Services
Online Directory Services
Online Shopping
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015
Strategic Issues
 Telecommunications network numbering
 Telecommunications standards
 Telecommunications network management
 Centralised maintenance
 Reliability
 Voice tariffs
 Forecasting future demand
 Telecommunications security
 Telecommuting
 Convergence of technologies
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015
EEE402F-b / EEE526Z
Convergent Networks
“The ability to communicate with high speed network
at affordable price is important to the people,
business, and industry in every country to complete
in global market.”
www.uct.ac.za/depts/commnetwork/
© 2005
Ref: G. Langley & J. P. Ronyne; Telecommunications
Primer, 4/e; Pitman Publishing, 1993
Mqhele E. Dlodlo & H. Anthony Chan
EEE402F Module B: Convergent Voice and Data Network
Telecommunication Basics Tutorial
17 July 2015