CP2022 - Multimedia Computer Communication

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


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


User A User B

Encoding Decoding

Channel


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Models

Mostly multiple levels are used


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


User A User B

High-level encoding

Channel


Low-level encoding

High-level decoding


Low-level decoding

High-level encoding


Low-level encoding

Media encoding

High-level 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


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Summary

Communication is about information

Information takes many forms Multimedia communication is

about encoding different forms of information on one or more channels with links between the different information types

Documents

CP2022 - Multimedia Computer Communication