Short name for wireless fidelity and is meant to be used generically when referring to any type of IEEE 802.11 network. Whether 802.11b, 802.11a, 802.11g etc. Wi-Fi is a wireless technology that uses radio frequency (ISM Band, 2.4/5 GHz) to transmit data through data through air.

1. MEASUREMENT OF POWER
CONSUMPTION IN DIFFERENT
PROPAGATION MODELS USING
Wi-Fi - a case study

2. Wi-Fi
Case 1 study of quasi-open
propagation model
Conclusion
Future work
Bibliography
Outline

3.  What is Wi-Fi
 Why Wi-Fi
 Brief history of Wi-Fi
 Various transmission impairments
 Channel modeling
 Log-distance path loss model
 Disadvantages
 Case study 1- quasi-open propagation environment
 Matlab program for pathloss graph
 Conclusion
 Future work
 Bibliography
CONTENTS

4. • Short name for wireless fidelity and is meant to be
used generically when referring to any type of IEEE
802.11 network. Whether 802.11b, 802.11a, 802.11g
etc.
• Wi-Fi is a wireless technology that uses radio frequency
(ISM Band, 2.4/5 GHz) to transmit data through data
through air.
What is Wi-Fi ?

5.  Setup cost - Reduced cabling required
 Flexibility - Quick and easy to setup in temperature and
permanent space
 Scalable - Can be expanded with growth
 Freedom - You can work from any location that can get a
signal
Why Wi-Fi ?

6.  Lower total cost of ownership – Because of
affordability and low installation cost.
 Additionally- Mobile users can access the corporate
network from any public hotspot using VPN.
Why Wi-Fi ? (contd.)

7.  IEEE established the 802.11 group in 1990.
Specifications for standard ratified in 1997.
 Initial speed were 1 and 2 Mbps.
 IEEE modified the standard in 1999 to include 802.11 a
and b.
 802.11 g was added in 2003.
 802.11 b equipment first available, then a, followed by
g.
 IEEE create standard but wireless Ethernet
compatibility alliance certifies products.
Brief History

8.  Attenuation: The strength of a signal falls off with
distance over any transmission medium.
 Free space loss: A receiving antenna will receive less
signal power the farther it is from the transmitting
antenna. This form of attenuation is known as free
space loss.
 Fading: Fading refers to the time variation of received
signal power caused by changes in the transmission
medium or path.
VARIOUS TRANSMISSION
IMPAIRMENTS

9. Multipath: Multipath is caused by the following
propagation mechanisms: -
 Reflection
 Diffraction
 Scattering
 Refraction
 Noise
 Atmospheric absorption.
Various transmission impairments
(contd.)

10.  A channel model is useful in determining the
mechanisms by which propagation in the indoor
environment occurs, which in turn is useful in the
development of a communication system.
 Indoor channels are highly dependent upon the
placement of walls and partitions within the building.
As placement of these walls and partitions dictates the
signal path inside a building.
Channel Modeling

11.  In both indoor and outdoor environments the
average large-scale path loss for an arbitrary
Transmitter-Receiver (T-R) separation is expressed
as a function of distance by using a path loss
exponent, n.
 The average path loss PL(d) for a transmitter and
receiver with separation d is:
 PL(d)=PL(d0)+10•n•log10(d/d0)
Log-distance Path Loss Model

12. Wireless LAN is typically deployed as an extension of an
existing wired network as shown below
Wireless LAN Topology

13. • Planning – Depending on the goal
• Security - Greater exposure to risks
• Range – Affected by various media
• Travels best through open space
• Reduced by water, walls, glass etc.
Disadvantages

14. Quasi-Open Propagation
Environment

15. DISTANCE (M) TRANSMITTER
SIGNAL
STRENGTH (dB)
RECEIVER
SIGNAL
STRENGTH
(dBm)
POWER
CONSUMTION
(watt)
3 -11 -30 13.1
6 -17 -41
9 -21 -49
12 -18 -43
15 -21 -51
18 -22 -54 12.4
21 -17 -66
24 -18 -63
27 -16 -66
OBSERVATION TABLE

16. DISTANCE (M) TRANSMITTER
SIGNAL
STRENGTH (dB)
RECEIVER
SIGNAL
STRENGTH
(dBm)
POWER
CONSUMTION
(watt)
30 -18 -61
33 -18 -69
36 -22 -80 12.6
39 -25 -75
42 -23 -78
45 -26 -81
48 -25 -76
51 -29 -75
54 -17 -72 12.2
OBSERVATION TABLE (contd.)

17. DISTANCE (m) TRANSMITTER
SIGNAL
STRENGTH (dBm)
RECEIVER
SIGNAL
STRENGTH
(dm)
POWER
CONSUMTION
(watt)
57 -15 -66
60 -23 -77
63 -21 -70
66 -27 -82
69 -17 -67
72 -12 -73 12.4
75 -17 -74
78 -16 -57
81 -15 -69
OBSERVATION TABLE
(contd.)

18. DISTANCE (M) TRANSMITTER
SIGNAL
STRENGTH (dBm)
RECEIVER
SIGNAL
STRENGTH
(dBm)
POWER
CONSUMTION
(watt)
84 -15 -67
87 -15 -75
90 -16 -76 12.3
93 -16 -75
96 -15 -79
99 -16 -73
102 -34 -87
105 -22 -86
108 -26 -83
OBSERVATION TABLE (contd.)

19. y=[19 24 28 25 30 32 49 45 50 43 51 58 50 55 55 51 46 55
51 54 49 55 50 61 57 43 54 52 60 60 59 64 57 53 64 57];
x=1:1:36;
lx=log10(x);
p=polyfit(lx,y,1);
figure(1)
plot(lx,y,'o');
xlabel('log10(d/d0)');
ylabel('pathloss(dBm)');
MATLAB PROGRAM FOR
PATHLOSS GRAPH

20. Plot for finding out pathloss
coefficient(n)

21. So far , we have studied one environment in this
semester (i.e.- Quasi-open environment).
Few more environments are needed to be studied in
order to draw a conclusion about the energy efficient
propagation model but we are able to find out only the
path-loss coefficient(n) in the present semester.
CONCLUSION

22. In the next semester, we shall be
concluding with our rest of the
observation readings in some more
environments i.e... closed environment;
open environment; dense
environment.
FUTURE WORK

23. T H A N K
Y O U
FOR
PAYING
ATTENTION