Computer
communication
Introduction
The ICT is an acronym
that stands for Information
Communications Technology.
However, apart from explaining an acronym, there is not a universally
accepted definition of ICT? Why? Because the concepts, methods and applications
involved in ICT are constantly evolving on an almost daily basis. Its difficult
to keep up with the changes - they happen so fast. A good way to think about
ICT is to consider all the uses of digital technology that already exist to
help individuals, businesses and organizations use information. ICT
covers any product that will store, retrieve, manipulate, transmit or receive
information electronically in a digital form. For example, personal
computers, digital television, email, robots. Hence ICT
plays a major role in day to day life. Let us briefly analyze about computer
communication.
Synopsis
ü Tele-text
ü Video text
ü Human computer interface
Teletext
According to oxford dictionary teletext
means computerised service providing information on television screens
experimental television broadcasting started in the 1920s in the United states
of America. Teletext is a one-way, or non-interactive, system for transmission of
text and graphics via broadcasting or cable for display on a television
set. A decoder or microchip resident in the TV set is needed to extract the
teletext information[1]. The information
is organised in 'pages' using alphanumeric characters and block graphics. Pages
are transmitted in a continuous cycle. Pages are accessed by keying a
three-digit number on a remote- control keypad and waiting for the selected
page to arrive
Teletext is free, simple and up-to-date
(well, mostly). It consists of a variety of numbered frames that you can access
via a suitably equipped television or computer[2]. These frames contain
up-to-date news, TV guides, chat, advertising, and other things that the
broadcaster thinks may be of use to you. Teletext is aimed mainly at the domestic
user, though some of the information has commercial importance. People are able
to obtain information at any time the TV station is transmitting. People can
see the news, for example, without waiting for certain times of day and they
can choose for themselves how long to spend on any particular item. Teletext
information is frequently updated and urgent newsflashes can be made to appear
on the screen as scan as the information is available. People whose hearing is
not very good can use teletext subtitles to follow the main TV programme. Not
all programmes are subtitled but the service covers news reviews,
documentaries, films and other entertainments.
Who
provides Teletext[3]
Teletext in Britain is transmitted by
the BBC as CEEFAX on BBC 1 and BBC 2 and also by Independent Television on
Channel 3 and 4 as ORACLE. The name 'CEEFAX' is obviously a play on the words
'SEE' and' FACTS'. The word 'ORACLE' means one who speaks knowledge or wisdom
and also stands for 'Optional Reception of Announcements by Coded Line
Electronics'.
Types and information
services through Teletext
ü
News
and current affairs
ü
Travel
information, Road, Rail. Sea and Air
ü
Weather
forecasts
ü
Sports
fixtures and results
ü
TV
Programme information (listings and background)
ü
Subtitles
for programme being shown
ü
Financial
information, personal and business; Market prices
ü
Amusement,
puzzles, quizzes and competitions;
ü
Holidays
and Shopping
ü
Advertisement
Advantage
of Teletext[4]
ü
Up
to the minute Information can to provided.
ü
Information
can be changed as new situations develop.
ü
Teletext
provides subtitles for hearing-impaired viewers.
ü
Viewdata
user can communicate in the system to order goods
ü
Data
can be stored from Viewdata or teletext on personal computers.
ü
Teletext
is free whereas newspaper and magazines have to be paid for.
Limitations
of teletext[5]
The
main limitations of CEEFAX and ORACLE are
ü
The
types, range and depth of information available; some other countries make
much
more extensive use of teletext.
ü
The
display method used in teletext and viewdata; 24 rows of 40 columns,
limited character set with very low
resolution (block) graphics and very limited animation.
ü
The
number of pages available; a few hundred pages on each channel.
ü
The
access time or delay waiting for a page to 'arrive'.
The number of pages available is limited
by the rate of data transmission and the average length of time users are
willing to wait for the page to 'arrive'. Increasing the number of pages would
mean that the cycle-time would be increased unless the capacity of the
transmission system was also increased or example by using more lines of the
transmuted TV signal for teletext.
Video text
Videotext is
more complex and expensive system
provides viewers with two-way interactive service. Using either cable or telephone lines, the viewer can connect the
home television terminal to a central computer and either call up a broad range
of news and information or conduct business transactions.
Broadcasting
magazine illustrates the difference between teletext and videotext with this
example: “A teletext service might allow a user to access an airline’s
schedule, but the videotext user could not only access that schedule but also
make the reservation, transfer money from his bank account
to pay for the ticket, then buy a new wardrobe for his planned trip- all without leaving his seat”
The video
text customer is charged for the amount of use made of the system. Videotext has been called the Cadillac of
cable information systems and teletext the Chevrolet. Although several major corporations have
spent millions of dollars in developing videotext systems, participation by
consumers and advertisers has been
disappointing so far. The times
mirror company and knight-ridder
newspapers, Inc., closed their gateway and viewtron projects in 1986
because of heavy losses. Representatives
of the two companies agreed that their
subscribers were more interested in exchanging messages with each other electronically
than in receiving news.
Videotext
has failed as a news medium in the United States because of public apathy. It
does have a role, perhaps eventually a substantial one, in providing
special services such an banking and commercial transactions and certain
categories of limited –interested information.
Video bursts forth
Video cassette recorders had a enormous
upsurge in popularity during the 1980s.
Anxious to add another piece of entertainment machinery to their
homes. Americans by the millions
bought VCRs. By the end of 1988, according to nielson
survey, 62 percent of U.S. homes had a VCR and the figure was still climbing
although more slowly as demand was met.
The tapes video store rent and sell are packaged to resemble books and
increasingly contain material transferred from books yet video is more than a
borrower. It is going direct from the creator to the home viewer. This enables the viewers to watch what they
wish, when they wish and to view their favorite tapes over and over again.
ü
Videos
influences film production
ü
Videos
as news
ü
Video
and Books
ü
Advertising
and Marketing
ü
Politics
and video
ü
Video
for entertainment
ü
Video
for education
ü
Movies
in the living rooms
Computer
mediated communication
The history
of computer-mediated communication (CMC) is more than fifty years old and since
the mid-1990s, the fast-growing popularity and ubiquity of personal computers
has caused CMC to become very attractive to scholarly attention. CMC is a form
of human communication using computer and internet network and this
Internet-based communication takes place on global collection of networks that
uses the Transmission Control Protocol/Internet Protocol (TCP/IP) suite for
data exchange. In this era of
information and communication technologies (ICT), computer-mediated
communication is a basic infrastructure that every organizations need to be
equipped with the adoption of communication software, it helps the flow of
communication among the organization and its employees.
For
the video condition, As with
face-to-face chat, video chat enables a greater quantity of statements and
allows for visual and auditory paralinguistic communication. Thus, group
salience would be higher than in text-chat, but de-individuation would be lower
between the video and text mediated conditions. This shows us there is a vast
difference between face to face communication and communication through video
conference.
Human computer interface
Concept of Human-Computer
Interaction/Interfacing (HCI) was automatically represented with the emerging
of computer, or more generally machine, Sometimes called as Man-Machine
Interaction. Most important factor of a HCI design is its configuration. In
fact, any given interface is generally defined by the number and diversity of
inputs and outputs it provides. Architecture of a HCI system shows what these
inputs and outputs are and how they work together.
Functionality
and usability
Functionality of a system
is defined by the set of actions or services that it provides to its users.
However, the value of functionality is visible only when it becomes possible to
be efficiently utilised by the user. Usability of a system with a
certain functionality is the range and degree by which the system can be used
efficiently and adequately to accomplish certain goals for certain users. The
actual effectiveness of a system is achieved when there is a proper balance
between the functionality and usability of a system.
Graphical User Interface
(GUI)
Graphical User interface combines pictures & text Accepts input via devices such as keyboards &
mouse
and it offers graphical icons and visual indicators E.g.
Microsoft Windows
Advantages : Intuitive and
easy to navigate (sounds, pictures and video incorporated) and Good for novice users.
Disadvantages: It can be
slow on old machines and hidden commands must be found using help.
Conclusion
Human beings have been communicating in one way or
another for a very long time. However their ability to use a medium to store
their messages to be retrieved later or to transport them from one place to
another. So computer communication plays a vital role especially teletext,
videotext and human computer interface adding these in an effective manner.
Thus ICT plays key role in our day to
day communications.
Bibliography
ü
Agee,
Warren k., Phillip H. Ault, Edwin Emercy.
Introduction to Mass Communications. New York : Harper Collins Publishers.,1991.
ü
http://stakeholders.ofcom.org.uk/binaries/enforcement/content-sanctions-adjudications/teletext.pdf
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