Ans :
Communication
Communication the process of sharing ideas, information, and messages with others
at a particular time and place. Communication is a vital part of personal life and is
also important in business, education, and any other situation where people encounter
each other. Communication between two people is an outgrowth of methods
developed over centuries of expression. Gestures, the development of language, and
the necessity to engage in joint action all play a part. Communication, as we see it
today, has evolved a long way. We will discuss the primitive modes of
communication briefly.
i) Early Methods
Early societies developed systems for sending simple messages or signals that could
be seen or heard over a short distance, such as drumbeats, fire and smoke signals, or
lantern beacons. Messages were attached to the legs of carrier pigeons that were
released to fly home (this system was used until World War I, which started in 1914).
Semaphore systems (visual codes) of flags or flashing lights were employed to send
messages over relatively short but difficult-to-cross distances, such as from hilltop to
hilltop, or between ships at sea.
ii) Postal Services
The postal system is a system by which written documents normally enclosed in
envelopes, and also small packages containing other matter, are delivered to destinations
around the world. Anything sent through the postal system is called post.
In India the East India Company in Mumbai, Chennai and Calcutta introduced the
postal system in 1766, further these postal service became available to the general
public. Even after implementing different electronic communication mediums, postal
system is still one of the popular communication systems available.
iii) Telegraph
The first truly electronic medium for communication was the telegraph, which sent
and received electrical signals over long-distance wires. The first practical
commercial systems were developed by the physicist, Sir Charles Wheatstone and the
inventor Sir William F. Cooke in Great Britain, and by the artist and inventor Samuel
F. B. Morse in the United States. Morse demonstrated the first telegraph system in
New York in 1837. But regular telegraph service, relaying Morse code (system of
code using on and off signals), was not established until 1844. Telegraphers would
translate the letters of the alphabet into Morse code, tapping on an electrical switch,
or key. The telegrapher at the other end of the line would decode the tapping as it
came in, write down the message, and send it to the recipient by messenger. The
telegraph made it possible for many companies to conduct their business globally for
the first time.
iv) Telephone
Early devices capable of transmitting sound vibrations and even human speech
appeared in the 1850s and 1860s. The first person to patent and effectively
commercialize an electric telephone was Scottish-born American inventor Alexander
Graham Bell. Originally, Bell thought that the telephone would be used to transmit
musical concerts, lectures, or sermons.
The telephone network has also provided the electronic network for new
computer-based systems like the Internet facsimile transmissions, and the World
Wide Web. The memory and data-processing power of individual computers can be
linked together to exchange the data transmitted over telephone line, by connecting
computers to the telephone network through devices called modems (modulator demodulators).
v) Computers and Internet
The earliest computers were machines built to make repetitive numerical calculations
that had previously been done by hand. While computers continued to improve, they
were used primarily for mathematical and scientific calculations, and for encoding
and decoding messages. Computer technology was finally applied to printed
communication in the 1970s when the first word processors were created.
At the same time computers were becoming faster, more-powerful and smaller, and
networks were developed for interconnecting computers. In the 1960’s the Advanced
Research Projects Agency (ARPA) of the U.S. Department of Defense, along with
researchers working on military projects at research centers and universities across
the country, developed a network called the ARPANET, for sharing data and
processing time of uniform computer connection over specially equipped telephone
lines and satellite links. The network was designed to survive the attack or destruction
of some of its parts and continue to work.
Soon, however, scientists using the ARPANET realized that they could send and
receive messages as well as data and programs over the network. The ARPANET
became the first major electronic-mail network; soon thousands of researchers all
over the world used it. Later on the National Science Foundation (NSF) helped
connect more universities and non-military research sites to the ARPANET, and
renamed it the Internet because it was a network of networks among many different
organizations.
TCP/IP Protocols
Today, the Internet is the widely known computer network. It uses interconnection of
computer system by both wired and wireless. Smaller networks of computers, called
Local Area Networks (LANs), can be installed, in a single building or for a whole
organization. Wide Area Networks (WANs) can be used to span a large geographical
area. LANs and WANs use telephone lines, computer cables, and microwave and
laser beams to carry digital information around a smaller area, such as a single
college campus. Internet can carry any digital signals, including video images,
sounds, graphics, animations, and text, therefore it has became very popular
communication tool.
0 टिप्पणियाँ:
Post a Comment