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CP2022 - Multimedia Internet Communication
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CP2022 - Multimedia Computer Communication
Lecture 1 - Communication
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Module teaching team
Module leader – Prof. Andy Sloane Room MI114 - Extn. 1445 Email [email protected]
Tutorial group lists will appear on the module web page in Week 2
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Outline Summary
All details are available on the module Websitehttp://www.scit.wlv.ac.uk/~cm1950/CP2022/
Recommended course textInternet Multimedia by Andy Sloane Palgrave, 2005 ISBN 1-4039-3413-4
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Weekly schedule
3-hour block 1.5 hour Lecture 1.5 hour Workshop (weeks 1-6) or Tutorial (Weeks 7-12) See schedule on web page for details Attend the tutorial/workshop group assigned
on the web page Make sure you know your assigned marker’s
email!
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Outline summary
1 Introduction to communication2 Computer communication 13 Computer communication 24 The Internet and WWW5 Information structure and
encoding6 Mixed information types
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Outline summary
7 HTML and hypertext8 PC and media exchange standards9 Media communication standards10 Business communication11 Case study 1 - Intranet12 Course summary (revision) lecture
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Principles of Communication Communication is
The transfer of information The transfer needs
A channel Multimedia communication uses
Multiple channels
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Channels
Examples
Sound travels through the air Air is the medium used there are many
channels Light and radio waves are
electromagnetic radiation the medium is the “ether” Different frequencies give different
channels
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Choice of channel
Availability of channel Availability of equipment Ability to use channel Ability to understand message Economic considerations Time problems
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Matching the channel to the information Example
Tennis match Score only - use text or speech More precise information - pictures
can illustrate (e.g. racket shape, players, logos etc)
Full transmission of all available information would need video
multiple channels if including many camera angles
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Media type and use
Complexity
Size of object
Video
Image High quality sound
Speech qualitysound
Text
More complex information leads to bigger data objects
Communication of these requires bigger channels i.e. more “capacity” or “bandwidth”
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Information
Data is the “raw” quantity Information is data with
“meaning” and “structure” ExamplesData Information2343256 Telephone number of a friend29WS157QQ UK House number and postcode2894251992 Product code of a compact disc
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Information structure
Data uses symbols Examples
Name SymbolsBinary numbers 0 1Denary numbers 0 1 2 3 4 5 6 7 8 9 English alphabet a b c d e f g h i j k l m n o p q r s t u v w x y z
Symbols can be different but represent similar information
E.g Greek, Cyrillic, Arabic or English alphabets all represent sounds
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Digital Information
In computer communication a message might be
234556671+25+23456673+100+23456688+10 This could be
Order
Part Number Quantity
234556671 2523456673 10023456688 10
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Communication of Information Communication may involve errors In digital communication where
binary is used errors cause 1 to become 0 and 0 to become 1
To detect or correct errors requires extra information (redundancy)
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Models of communication
Models are used to describe the process of communication
In ideal conditions
Information Information
User A User B
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Models
Information Information
User A User B
Information transfer may be slightly faulty
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Models
Noise affects information transfer
Information In%$£$at@@n
User A User B
Noise
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Models Data encoding is used to transfer information Process model
Information Information
User A User B
Encoding Decoding
Channel
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Models
Mostly multiple levels are used
Information Information
User A User B
High-level encoding
Channel
Intermediate encoding
Low-level encoding
High-level decoding
Intermediate decoding
Low-level decoding
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Models
Multimedia uses multiple encodings
Information Information
User A User B
High-level encoding
Channel
Intermediate encoding
Low-level encoding
High-level decoding
Intermediate decoding
Low-level decoding
High-level encoding
Intermediate encoding
Low-level encoding
Media encoding
High-level decoding
Intermediate decoding
Low-level decoding
Media decoding
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Example
Levels of encoding An electronic mail message High level
Language of the communication Written symbols used Computer representation of the symbols
(ASCII) Electronic binary signals (0 and 1)
Low level
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Principles of communication Standards Protocols Error control, redundancy and
accuracy Channel Context Coding
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Standards
These can define a communication in some or all areas
ExampleIn an email message
The text will be in a standard language
Message format will be standard Needs standard protocols for transfer
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Digital communication
All information used by computers is digitally encoded
In multimedia these areVideoAudio Speech
Sound and musicImage Graphics
PictureText Free format
Structured information