Transcript Data Communication Medium

Data communication
What is data communication?
Transmission of data from one place to another
place is called data communication.
Basic parts of data communication
Three components are essential in data
communication.
1. Sender / Source
2. Data Communication Medium
3. Receiver / Sink
Basic parts of data communication
Sender/Source
Medium
Receiver/Sink
Sender / Source
Sender or source is the data producer.
The receiver is the person who gets data at the
end.
E.g.: Imagine you call a friend of yours.
Then you become the Sender or Source.
Sender
Receiver
Data Communication Medium
The medium which is used to transmit data to
the receiver.
E.g.: In the example mentioned above, telephone
becomes the data communication medium there.
Receiver
Data Communication
Media/Medium
•Various media are used for data communication.
•It is possible to divide all these media into two
main types.
1) Guided Media
2)Radiated /Unguided Media
Guided Media
A particular physical medium is used for data
communication.
Radiated Media
Communicating data using media which is not
physical, is called radiated media.
Eg: Radio transmission, Infrared, Microwaves
Guided Media
Following wires can be classified under
guided media.
•Twisted wire pair (Twisted pair cables)
•Co-axial Cable / Coaxial cables
•Fiber optic cables
Twisted wire pair
Advantages of Twisted pair cable
• Can carry both analog and digital data.
• Easy to implement and terminate.
• It is the least expensive media of transmission
for short distances.
Disadvantages of Twisted pair cable
• Very poor security and is relatively easy to tap.
• Thin in size, they are likely to break easily.
Applications of Twisted Pair Cables
•Telephone lines to carry voice and data channels.
•ADSL lines.
•Some Local area networks.
•ISDN (Integrated Services Digital Network).
Co-axial Cable / Coaxial cable
It has a copper net woven around a copper wire.
Applications of Coaxial cables
•Used in digital transmission
•Used for analogue transmission
•Used for TV antennas and Cable TV
Advantages of Coaxial cables
•Easy to install
•Not expensive
•Since it shielded, can span a higher distance at
higher speed than twisted pair.
•Less data loss
Disadvantages of Coaxial cables
•Higher cost compared to twisted pair
•Cables easily get damaged
Fiber Optics
Applications of Fiber Optics
•Military -They offer better performance and
greater security for their signals.
They're strong, and lightweight, and can also be
used outdoors in harsh environments.
•Radar systems
•Telecommunications companies to transmit
telephone signals
•Internet communication
•Cable television signals
Advantages of Fiber Optics
•Carry signals with much less energy loss than
copper cables.
•Much lighter and thinner than copper cables.
•Difficult to tap information.
•Supports for long distances.
•Supports for very high speed network
communications.
Disadvantages of Fiber Optics
•It's very expensive.
Radiated Media (Unguided Media)
•No physical medium is used here to send data.
Radiated Media (Unguided Media)
1. Radio transmission
Radio transmission, which is very familiar to our
normal lives, can be used for data communication
very easily.
Radiated Media (Unguided Media)
2. Infrared
•It has a very low frequency.
•These are largely used for data communication
when wire- less keyboards, mouse and printers
are used.
Radiated Media (Unguided Media)
3. Microwaves
•Used to communicate data to a long distance
and short signals with contain higher frequency.
•Microwave links use very high frequency
radio waves to transmit data through space.
Microwaves
Communication satellites
END