Transcript CP2022 -Lecture 4

CP2022
INTERNET
and
World Wide Web
Multimedia Internet
Communications - Lecture 4
1
A simple view of the Internet
Your computer
The Internet
A network of networks
World-wide inter-linked computers…
Multimedia Internet
Communications - Lecture 4
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What is the Internet ?
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Large collection of connected computers across the
world
Linked networks and networks within networks……
Began in 1970s - mainly US-based academic, military
and research networks
Used mainly for research and knowledge sharing
purposes
One aim was to establish a facility to enable
communication even in the event of a nuclear attack
Multimedia Internet
Communications - Lecture 4
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Evolution of the Internet
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Internet = email, file transfer, newsgroups, and
hypertext transfer (WWW)
Over recent years the size and scope of the
Internet network(s) have almost ‘exploded’
World-wide group of users of millions …. And still
growing
Redesign/restructuring is an issue - to cope with
this phenomenal growth and the increasing use
of multimedia.
Multimedia Internet
Communications - Lecture 4
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What Services are Offered ?
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Email
The World Wide Web based on the hyper-text
transfer protocol (http)
Millions of sites for a range of
subjects/interests
File transfer
Discusssion forums, instant messaging, online
services (e.g. library renewals)
Streaming multimedia
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Communications - Lecture 4
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EMAIL - advantages
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Speed (especially long distance)
Reduction in paperwork (for memos)
Messages/documents transmitted +
received when convenient
Permanent record of dialogue
Direct access can be a ‘social leveller’
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Communications - Lecture 4
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EMAIL - disadvantages
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Junk mail /Spam
Face - face dialogue has the edge
Systems fail!
Delays in receipt can be unpredictable
and excessive
Access constraints (to hardware) can be
limiting
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Communications - Lecture 4
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How do you access the WorldWide Web?
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Uses a computer program called a browser
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Microsoft Internet Explorer
Netscape navigator
Others
Give the name of the computer you want to access
and the location of the file ! (URL)
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e.ghttp://www.scit.wlv.ac.uk/~cm1950/CP2022/images/bridge.JPG
Or use the mouse to click on links
Or use bookmarks to return to frequently visited sites
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Communications - Lecture 4
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What is on the Web ?
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Academic Publications and
Research/reference information
Non-academic information (e.g. on football
teams, celebrities etc.)
Services such as shopping, buying books and
software, renewing library books, etc.
Scope of use is widening - video
broadcasting, remote directed surgery,
interactive entertainment, etc.
Multimedia Internet
Communications - Lecture 4
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How do you find useful information?
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There are millions of documents on the
web to search through ! Luckily there
are tools to help.
Try using a Search ‘Engine’. For
example, Google, Alta Vista,
An example web page:http://www.andysloane.info/
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Communications - Lecture 4
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Internet communication
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TCP/IP is used to communicate packets of
information between users and other
parts/users of the Internet.
Permanent connections
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High data rate links at universities
Broadband connections
Dial-up access via telephone/ISDN lines
Individuals can access through ISPs
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(Internet service providers) or other
establishments (e.g.university)
Multimedia Internet
Communications - Lecture 4
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Some predictions (1998)
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A U.S. survey predicted by 2002:
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PCs = net access in 47 m homes
TV based = 12.7 m homes
Screen phones = 2.6m homes
Now - 250m Internet users in the North America
http://www.internetworldstats.com
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PC-centric Net and TV-centric Net (web-TV)
‘intelligent’ software used on shopping web sites
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keeps track of users’ preferences and interests
leads to ability to suggest products etc.
Multimedia Internet
Communications - Lecture 4
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Internet usage in the EU
EU country
Austria
Belgium
Cyprus
Czech Republic
Denmark
Estonia
Finland
France
Germany
Greece
Hungary
Ireland
Italy
Latvia
Lithuania
Luxembourg
Malta
Netherlands
Poland
Portugal
Slovakia
Slovenia
Spain
Sweden
United Kingdom
European Union
Population (2006 Est.)
8,188,806
10,481,831
961,154
10,211,609
5,425,373
1,339,157
5,260,970
61,004,840
82,515,988
11,275,420
10,060,684
4,065,631
59,115,261
2,293,246
3,416,941
459,393
385,308
16,386,216
38,115,814
10,501,051
5,379,455
1,959,872
44,351,186
9,076,757
60,139,274
462,371,237
Internet Users
4,650,000
5,100,000
298,000
4,800,000
3,762,500
670,000
3,286,000
26,214,174
48,722,055
3,800,000
3,050,000
2,060,000
28,870,000
810,000
968,000
270,800
301,000
10,806,328
10,600,000
6,090,000
2,276,000
950,000
17,142,198
6,800,000
37,800,000
230,097,055
Penetration %
Use %in EU Growth 2000-5
56.8 %
2.0 %
121.4 %
48.7 %
2.2 %
155.0 %
31.0 %
0.1 %
148.3 %
47.0 %
2.1 %
380.0 %
69.4 %
1.6 %
92.9 %
50.0 %
0.3 %
82.8 %
62.5 %
1.4 %
70.5 %
43.0 %
11.4 %
208.4 %
59.0 %
21.2 %
103.0 %
33.7 %
1.7 %
280.0 %
30.3 %
1.3 %
326.6 %
50.7 %
0.9 %
162.8 %
48.8 %
12.5 %
118.7 %
35.3 %
0.4 %
440.0 %
28.3 %
0.4 %
330.2 %
58.9 %
0.1 %
170.8 %
78.1 %
0.1 %
652.5 %
65.9 %
4.7 %
177.1 %
27.8 %
4.6 %
278.6 %
58.0 %
2.6 %
143.6 %
42.3 %
1.0 %
250.2 %
48.5 %
0.4 %
216.7 %
38.7 %
7.1 %
218.2 %
74.9 %
3.0 %
68.0 %
62.9 %
16.4 %
145.5 %
49.8 %
100.0 %
147.0 %
Multimedia Internet
Communications - Lecture 4
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More snippets …..
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Trend for commercial web sites to look
for ‘value added’ content to attract and
retain interest (discussion forums)
Fastest growing groups of web users under 18s and over 55s
Average web users surfs for 1-2
hours/day
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Communications - Lecture 4
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And more snippets ….
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Users’ online time (survey):
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Entertainment sites = 14%
Education = 1%
Communications 1/4%
84% regularly use E-Mail
40% visit chat rooms/discussion forums
Internet2 - the ‘next generation’ internet will
be up to 1,000 times faster
(over next few years)
Multimedia Internet
Communications - Lecture 4
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Summary
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The Internet is now a primary means of
communication
It isn’t designed for multimedia
Now difficult to work without email
Web browsing is both work and leisure
activity
The Internet is being developed for greater
speed and better access to information
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Communications - Lecture 4
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