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Computer Science
Project
Communication and
Network concepts
• Transmission media
 twisted pair cable
 coaxial cables
 optical fibers
Microwave
Radio wave
Satellite
• Data communication terminologies.
• Transmission media is also known as
communication channels.
• They are the cables that connect two or mare
workstations.
• Two categories:
1.guided media-include cables.
2.unguided media-include waves through air,
water or vacuum.
Twisted pair cable
• Common form of wiring in data
communication application.
• Voice grade medium(VGM)-basis for
telephone wiring.
• Consists of two identical wires wrapped
together in a double helix.
• Twisting of wires reduces crosstalk
• Unshielded twisted pair cable(UTP)
Shielded twisted pair cable(STP)
Simple
Easy
install &
maintain
Inexpensive
Advantages
Physically
flexible
Easily
connectable
Low
weight
• Incapable of carrying signal over long distances due
to high attenuation.
• Low bandwidth capabilities-unsuitable for
broadband applications.
• max. data rates = 1 Mbps- without conditioning
10 Mbps with conditioning
•Consists of a solid wire core
surrounded by one or more
foil or wire shields, each
separated by a insulator.
•Inner core- carries signal
•Shield –provides the ground
•Suitable for high speed
communication & widely
used for TV signals.
Types
•Thicknet-can be upto 500 meters long. They are thicker than
thinnet
•Thinnet-using this cable max. distance of 185 meters can be
joined.
Advantages
• Can be used as the basis for a shared cable
network.
• Can be used for broadband transmission.
• Offer higher bandwidths- upto 400 MBPS.
Disadvantage
•Expensive.
•Not compatible with twisted pair cable.
•Consists of thin strands of glass or glass like
material.
•Light source –LEDs or laser diodes(LDs).
•Bandwidth is very high.
•Fiber cable consists of three pieces:
 core
Cladding
Protective coating
•Types
Single node
Multi node
• Immune to electrical and magnetic
interference.
• Highly suitable for harsh industrial
environments.
• Guarantees secure transmission and high
transmission capacity.
• Can be used for broadband transmission
where several channels are handled in
parallel.
•
•
•
•
•
Installation problem- very fragile
Connection looses are common problems.
Cables are more difficult to solder.
Light can reach the receiver out of phase.
Virtually impossible to tap due to noise
immunity.
• Most expensive.
Type
Type Sub
type
Max.Seg
ment
Length
Bandwidth
supported
installa cost
tion
Interferen
ce
Twisted
UTP
100 mts
100 Mbps
Easy
Cheapest
High
pair cable
STP
100 mts
500 Mbps
moder
moderate
moderate
ate
Coaxial
Thinnet
185 mts
10 Mbps
Easy
Cheap
Moderate
cable
Thicknet
500 mts
10 Mbps
hard
moderate
Low
Fiber
Multinude
2 kms
100 Mbps
Very
hard
Expensive
None
optic
Singlenode
100 kms
2 Gbps
Expensive
None
cable
Very
hard
Guided media
The different types of guided media
are :
1. Microwave
2. Radio wave
3. Satellite
The different types of other unguided
media are :
1. Infrared
2. Laser
cheaper
No use of
cables
Micro wave
advantages
Ability to
communicate
through oceans
Freedom from acquisition rights
and other governmental
requirements
Ease of
communication
Microwave
disadvantages
Radio wave
advantages
Offers mobility
disadvantages
Cheaper
Insecure
communication
Offers ease of
communication
Freedom from land
acquisition rights
Reduce signal
strength
Area
coverage is
large
High
investment
costs
Maintenance
easy
Satellites
advantages
High atmospheric
large
Can cover
areas of the earth
loses
Disadvantag
es
sparsely
Useful in
populated areas c loses
Satellite disadvantages
Over crowding of bandwidths
High investments cost
High atmospheric losses
other unguided media
Infrared
It uses infrared lights
Used in everyday life like remotes , automotive
garage doors and wireless speaker
Common in pda’s
Laser
It is a line of sight transmission
Point to point transmission
It can be adversely affected by weather
A channel is the medium which is
used to carry information or data
from one point to another.
It refers to the speed at which data
transfer is measured. It is generally
used to measure the speed of
information through a high speed
phone lines or modems.
Acknowledgement
First and foremost, we would like to thank Kiran
madam for having given us the opportunity
for expressing our ideas through this project.
We would also like to thank our friends for their
creative ideas without which this would have
been incomplete, last but not the least, we
would like to thank everyone who directly or
indirectly supported us.