This document discusses three main types of wireless media: microwave communication, satellite communication, and radio wave communication. Microwave communication transmits data through line-of-sight high frequency waves between towers 20-30 miles apart. Satellite communication overcomes obstacles by using satellites in orbit about 23300 miles above Earth to transmit between earth stations. Radio wave communication is the cheapest wireless option and can transmit both indoors and outdoors through buildings using omni-directional radio frequencies, though it is subject to interference.

2. Class- M.sc (CS) 1th
semester
Submitted by-
Ayushi Dubey
Submitted to-
Prof. Mr. Ravi Sir
Session-2017-18

4.  It refers to those channels that transmit data and
information in the form of waves.
 These are the communication channels in which data is
transmitted through the air instead cables i.e. there is no
physical path between two devices for the transmission of
data.
 Data signals are not bounded to cabling media therefore it is
also known as unbounded media.

5. The three main types of wireless media are-
oMicrowave Communication
oSatellite Communication
o Radio Communication

6. Microwave Communication
o These are the communication channels in which data is
transmitted through the air instead of cables.
o Microwave is the high frequency waves that can only be
travelled in straight lines.
o These can not bend or pass through obstacles.
o It is limited to particular city or community.

7. oThis may not be possible for long distance transmission
because signals become
oWeaker and require power amplification.
oRepeater on antennas are mounted at very high towers
usually 20 to 30 miles apart to overcome the problem of
weakening signals and line of sight.

8. Satellite Communication
o The main problem with microwave communication is that the
curvature of earth, mountains and other structures often blocks
the line of sight.
o Instead of antenna, satellite can also be used to transmit
microwave messages from one location to another.

9. o Satellite rotates approximately 23300 miles above the earth
in precise location.
o Satellite transmission stations that can both send and receive
messages are known as earth stations.
o The transmission from earth stations to satellite is called
uplink and transmission from satellite to earth station.
o Moon was used in the early years of satellite transmission.
o The time taken by a signal to reach the moon and back was
about 2 seconds. This time is called satellite delay and it is still
present in all our satellite communication.

10. oA large volume of data can be transmitted at a very high
speed.
oTransmission and reception costs are independent of the
distance between two points.
oDifferent communication satellite are used to carry different
kinds of information.
oTelephone calls, TV channels, internet, military
communication, weather and radio stations use these
satellites for broadcasting.
Advantages-

11. oThe bad weather can severely affect the quality of
transmission.
oSatellite transmission causes security problems because it
is to intercept the transmission travels through the air.
oIts cost of transmission is very high.
oSatellite delay is still present in all our satellite
communication.
Disadvantages-

12. Radio wave Communication
o This is the cheapest wireless media(although the price can
increase if more complicated and advanced equipment is needed)
o Are easy to generate and can travel long distance
o As they can penetrate buildings, they are widely used for
communications both indoors and outdoors.

13. o Radio waves are omni directional i.e. they can travel in all the
directions from the source, so the transmitter and the receiver
do not have to be aligned. Radio Waves
o Radio waves are frequency dependent.
o At low frequencies, radio wave pass through obstacles very
well
o At all the frequencies , radio waves are subject to interference
with other devices that operate on the same frequencies
o To avoid interference between users, government tightly
license the use of radio transmission.
oRadio waves are used for multicast communications, such as
radio and television, and paging systems