Data Communication in Computer Network
Data Communication:
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Data
communications is the exchange
of data between two or more devices via some form of transmission
medium such as a wire cable or wireless media.
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The
word data given, in whatever format refers to information
presented, is agreed upon by the parties creating and using the data.
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When
we communicate, we are actually sharing
information. This sharing can be
local or remote. Between people, local/native communication usually
occurs face to face, whereas remote
communication takes place over distance.
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For data communication network computers, telephone,
wireless devices, and TV that are linked together in network are used.
COMPONENTS:
A
data communications system has five components.
1. Message. The
message is the information (data) to be sent. Data may be available in the form
of text, numbers, pictures, audio, and video.
2.
Sender. The
sender is the network device that sends the data message. It can be a computer,
workstation, telephone handset, video camera, and any network device.
3. Receiver. The receiver is the network device that
receives the message. It can be a computer, workstation, telephone handset, video
camera and any network device.
4. Transmission medium. The
transmission medium is the physical path/link/communication channel by which a
message travels from sender to receiver. Some examples of transmission media
include twisted-pair wire, coaxial cable, fiber-optic cable, and wireless media
5. Protocol.
·
A
protocol is a set of rules that everyone has to follow in order to have proper
communication. It governs data communications. It represents an agreement
between the communicating devices.
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Without
having communication protocol, even though two devices may be connected but not
communicate with each other, just as a person speaking French cannot be
understood by a person who speaks only Japanese.
Information now a todays comes in several
forms such as text, numbers, images, audio, and video.
Text: In data communications, text is drawn
as a bit pattern, a sequence of bits (0s or 1s). The set of bit patterns are
designed to represent text symbols. Each set is termed a code, and also the
process of representing symbols is called coding.
Numbers: Numbers
are also represented by bit patterns. However, ASCII is not used to represent
numbers; the number is directly converted to a binary number to simplify
mathematical operations.
Images: Images
are also represented by bit patterns. In its simplest form, an image consist of
a matrix of pixels (picture elements), where each pixel is a small dot. The
size of the pixel is dependent on the resolution.
Video: It
refers to the recording or broadcasting of a picture or movie. Examples
.mp4,.mov,.3gp
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