Transcript Internet, the World Wide Web and Issues in Delivering

Internet, the World Wide
Web and Issues in
Delivering Multimedia
Content on the Net
Background
• Internet was born 1960s
• US DoD, create a non-centralized network
designed to survive partial nuclear war and still
function when parts of the network were down or
destroyed
• ARPANET (Advanced Research Projects
Agency Network) with the aim of providing a
secure and survivable communications network
for organizations engaged in defense-related
research
Background
• 1969, first attempted to implement a long
distance networked computers
• 4 computers linked by 50Kbp circuits
– UCLA
– Stanford Research Institute (SRI)
– UC Santa Barbara
– University of Utah in Salt Lake City
• Telephone connection
Background
• Standard protocols – IP (Internet Protocol)
• 1977 – TCP/IP (Transmission Control Protocol /
Internet Protocol)
• Allowed users to link various branches of other
complex networks directly to the ARPANet,
which soon came to be called the Internet
• MiliNet (dedicated to military research
establishment) and dropped the ARPAnet
• ARPAnet grew, 1985 National Science
Foundation (NSF) establish Internet access
across the United States
Background
• Internet – global network of computers
connected together using the TCP/IP technology
• Web (Encyclopedia Britannica 2002):
“WWW, (byname THE WEB), is the leading
information retrieval service of the Internet (the
worldwide computer network). The Web gives
users access to a vast array of documents that
are connected to each other by means of
hypertext or hypermedia links-i.e. Hyperlinks,
electronic connections that link related pieces of
information in order to allow a user easy access
to them”
Background
• How multimedia could help in utilizing the
Internet:
– Global exchanges of information, which could
contain media rich, content, i.e. electronic
mails enhanced by audio and video; and
– Creation of new environments for business,
education, entertainment and delivery of news
of information.
Delivering Multimedia Content on
the Web
• Content of Internet has transformed form
text-based environment to graphics,
animation, audio and video
• Graphics format used GIF, JPEG and GIF
• Streaming technology and compression
techniques help speed up the download
time
Audio and Video Streaming
• The audio file is broken up into small pieces
(streams) and then sent from the sever to the
client’s machine
• Browser on the client’s machine uses a helper
application (like RealAudio) to re-assemble the
audio stream
• Advantage
– No waiting time (or very little) from the time the mouse
is clicked until the time the sound start playing
• RealAudio producer to broken the audio file into
streams ready for broadcasting over the Internet
Compression
• Audio
– MIDI
• A musical score, such as notes and what instrument will play
these notes
– MPEG (MP3)
• Deletes the redundant information that human hearing could
not pick up, reducing the file size up to 12 times
• Video
– MPEG
• Remove spatial redundancy within the video frame and
temporal redundancy between frame
SMIL
• “The Synchronised Multimedia Integrated Language
(SMIL, pronounced ‘smile’) enables simple authoring of
interactive audiovisual presentations. SMIL is typically
used for ‘rich media’ / multimedia presentations which
integrate streaming audio and video with images, text or
any other media type. SMIL is an easy-to-learn HTMLlike language, and many SMIL presentations are written
using a simple text-editor” ~ W3C
• XML-based language that allows control over the what ,
where, and when of media elements in a multimedia
presentation.
SMIL
• Functionality
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Timing
Time manipulations
Animation
Content control
Layout
Linking
Media objects
Meta information
Structure and
transitions
SMIL
• <switch> mechanism used to enable the
client’s browser to make informed decision
about the presentation
– To check the internet connection of a client
• Tutorial
http://www.helio.org/products/smil/tutorial/
Mobile Multimedia Technology
• Emergence of multimedia computer systems
integrated into the telecommunications and
networking infrastructures and offer access to
services and applications using combinations of
data, text, voice, video to anybody, anytime,
anywhere
• 1980s Advanced Mobile Phone Systems
– First generation of cellular systems in U.S.
– Speech transmission
• NMT (Nordic Mobile Telephone System)
– Europe, use FM Modulation
Mobile Multimedia Technology
• GSM (Global System for Mobile
Communications)
– 2nd generation of mobile communication
– 13.8kbps
– Based on circuit switching
• Once the connection established, the user has the exclusive
access to certain amount of bandwidth until the connection
terminates
• Voice calls, send and receive data
– 2.5G, improved data capabilities, and “always-onconnection”
Mobile Multimedia Technology
• i-mode
– NTTDoCoMo largest cellular operator inJapan
– Wireless technology offering wireless web
browsing and email from mobile phones
– Access internet via their wireless phones
– Based on packet data transmission
Mobile Multimedia Technology
• 3rd generation (2005)
– Higher data rates (Mbps) intended for
applications other than voice – such as mobile
games
– Support full-motion video, video conferencing
and advanced data services with full Internet
access
– Universal Mobile Technology Services
(UMTS), 2Mbps
Mobile Multimedia Technology
• Bluetooth
– A short-range radio technology designed to simplify
peer-to-peer connectivity
– Enables mobile phones, printers, PCs and PDAs to
communicate directly with each other at high speeds
without the need for a network server or cables
– Uses radio transmission, transfers voice and data in
real time
– Operates in the 2.4Ghz frequency band (problem in
France!)
Mobile Multimedia Technology
• Application areas:
– M(Mobile)-commerce: shopping, ticket purchases, reservations,
and comparison shopping
– Finance: statements, funds transfer, and shares trading
– M-billing: notification, presentation, and payment of bills
– Enterprise Access: inventory, shipment/sales updates, and email
access
– M-care: customer service, payment status, and other backroom
operations
– Entertainment: games, gambling, and interactive multi-player
events
– Messaging: communication and collaboration
– Traveling: scheduling, reservations and advisories