1. Communication and Network concepts

2. Contents Transmission media Data communication terminologies.
twisted pair cable
coaxial cables
optical fibers
Microwave
Radio wave
Satellite
Data communication terminologies.

3. Transmission Media
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.

4. 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

5. Types Unshielded twisted pair cable(UTP)
Shielded twisted pair cable(STP)

6. Easy install & maintain
Advantages
Simple
Easy install & maintain
Physically flexible
Low weight
Easily connectable
Inexpensive

7. Disadvantages
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

8. Coaxial Cables
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.

9. Advantages Disadvantage
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.

10. Optical fibers
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

11. Advantages 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.

12. Disadvantages 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.

13. Comparison Table Type Type Sub type Max.Segment Length
Bandwidth supported
installation
cost
Interference
Twisted pair cable
UTP
STP
100 mts
100 Mbps
500 Mbps
Easy
moderate
Cheapest
High
Coaxial
cable
Thinnet
Thicknet
185 mts
500 mts
10 Mbps
hard
Cheap
Moderate
Low
Fiber optic cable
Multinude
Singlenode
2 kms
100 kms
2 Gbps
Very hard
Expensive
None

14. Guided media The different types of guided media are : Microwave
Radio wave
Satellite
The different types of other unguided
media are :
Infrared
Laser

15. Micro wave advantages cheaper No use of cables
Freedom from acquisition rights and other governmental
requirements
Ease of communication
Ability to communicate through oceans
No use of cables
Micro wave advantages

16. Microwave disadvantages
insecure
Susceptible to weather
Effects like rain
Cost of design high
Implementation tricky
Antenna may split up in different pathway
Microwave disadvantages

17. Radio wave Offers mobility Cheaper Insecure communication
Offers ease of communication
Freedom from land acquisition rights
advantages
Insecure communication
Reduce signal strength
disadvantages

18. Satellites advantages
Area coverage is large
Maintenance easy
Can cover large areas of the earth
Useful in sparsely populated areas c loses
Disadvantages
High atmospheric loses
High investment costs
Satellites advantages

19. Satellite disadvantages
Over crowding of bandwidths
High investments cost
High atmospheric losses

20. 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

21. IMPORTANT CONCEPTS TO BE KNOWN
A channel is the medium which is used to carry information or data from one point to another.
DATA CHANNEL
It is the unit of measurement for the
Info. Carrying capacity of a communication channel
This baud is synonymous with BPS another unit
Of measuring data transfer rates.
BAUD
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.
BITS PER SECOND

22. 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.