1.
Telecommunications: Telecommunication is
the science and Practice of transmitting information by electromagnetic means.
Communication is talking to someone or thing not
necessarily through technological means. Telecommunication, however, is talking
through technology meaning phones, Internet, radio etc.
In modern times, telecommunications involves the
use of electrical devices such as the telegraph, telephone, the use of radio
and microwave communications, as well as fiber optics and their associated
electronics, plus the use of the orbiting satellites and the Internet.
2. Radio
and television: In a broadcast system, the central high powered broadcast tower
transmits a high-frequency electromagnetic wave to numerous low-powered receivers.
The high-frequency wave sent by the tower is modulated with a signal containing
visual or audio information. The receiver is then tuned so as to pick up the
high-frequency wave and a
demodulator is used to retrieve the signal containing
the visual or audio information. The broadcast signal can be either analog (signal is varied continuously with respect to
the information) or digital (information is encoded as a set of discrete
values). The broadcast media industry is at a critical turning pointin its
development, with many countries moving from analog to digital broadcasts. This
move is made possible by the production of cheaper, faster and more capable
integrated circuits. The chief advantage of digital broadcasts is that they
prevent a number of complaints common to traditional analog broadcasts. For
television, this includes the elimination 9 problems such as snowy pictures,
ghosting and other distortion.
3. Internet: The
Internet is a worldwide network of computers and computer
networks that can communicate
with each other using the Internet Protocol (IP). Any computer on the Internet
has a unique IP address (IP address is a unique identification address of
devices that are a part of the computer network) that can be used by other
computers to route information to it. Hence, any computer on the Internet can
send a message to any other computer using its IP address. These messages carry
with them the originating computer's IP address allowing for two-way
communication. The Internet is thus an exchange of messages between computers.
4. Local
Area Networks and Wide Area Networks: Despite the growth of the
Internet, the characteristics of local area networks ("LANs" –
computer networks that do not extend beyond a few kilometers in size) remain
distinct. This is because networks on this scale do not require all the
features associated with larger networks and are often more cost-effective and
efficient without them. When they are not connected with the Internet, they
also have the advantages of privacy and
security.
There are also independent wide area networks ("WANS” –
private computer networks that can and do extend for thousands of kilometers.)
Once again, some of their advantages include their privacy, security, and
complete ignoring of any potential hackers – who cannot "touch" them.
Of course, prime users of private LANs and WANs include armed forces and
intelligence agencies that must keep their information completely secure and secret.
Videoconferencing uses audio and video telecommunications to bring
people at different sites together. This can be as simple as a conversation
between people in private offices (point-to point) or involve several
(multipoint) sites in large rooms at multiple locations. Besides the audio and
visual transmission of meeting activities, allied videoconferencing
technologies can be used to share documents and display information on
whiteboards.
With the introduction of relatively low cost, high capacity
broadband telecommunication services in the late 1990s, coupled with powerful
computing processors and video compression techniques, videoconferencing usage
has made significant inroads in business, education, medicine and media. Like
all long distance communications technologies (such as phone and Internet), by
reducing the need to travel to bring people together the technology also
contributes to reductions in carbon
emissions, thereby helping to reduce global warming.
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