The document discusses several topics related to wireless propagation modeling including:
1. The log-distance path loss model, which models received power as decreasing logarithmically with distance.
2. Log-normal shadowing, which describes how multipath effects cause random variations in the received signal at a given distance.
3. Methods for determining the percentage of coverage area where the received signal is above a threshold, including calculating the complementary cumulative distribution function.
4. Outdoor propagation models including the Longley-Rice model, Durkin's model, and the two-ray propagation raster model for irregular terrain.
5. Empirical models like Hata's model and its extension to personal communication services frequencies
Possible media for communication
Introduction to Communication Media
Introduction to Microwave communication
Manufacturers of Microwave
Why Microwave?
Characteristics of microwave
Types of Microwave communication
Types of Microwave Links
Requirements for the microwave communication
What is LOS?
Wave Propagation in the atmosphere
Multi path Propagation
LOS Purpose & requirements
Limitations of Line of Sight Systems
Design of Line of Sight Microwave Links
K- factor
Variations of the ray curvature as a function of k
Fresnel zone
Obstacles & Loses
Knife Edge Obstacles
Smooth Spherical Earth Obstacles
Path Loss
Other losses
Why vertical polarization favorable at high freq
Antenna type & Gain
RECEIVER SENSITIVITY, FADE MARGIN AND SIGNAL TO NOISE RATIO
Fading Margin
Reliability
Possible media for communication
Introduction to Communication Media
Introduction to Microwave communication
Manufacturers of Microwave
Why Microwave?
Characteristics of microwave
Types of Microwave communication
Types of Microwave Links
Requirements for the microwave communication
What is LOS?
Wave Propagation in the atmosphere
Multi path Propagation
LOS Purpose & requirements
Limitations of Line of Sight Systems
Design of Line of Sight Microwave Links
K- factor
Variations of the ray curvature as a function of k
Fresnel zone
Obstacles & Loses
Knife Edge Obstacles
Smooth Spherical Earth Obstacles
Path Loss
Other losses
Why vertical polarization favorable at high freq
Antenna type & Gain
RECEIVER SENSITIVITY, FADE MARGIN AND SIGNAL TO NOISE RATIO
Fading Margin
Reliability
Loss of strength, A periodic reduction in the received strength of a radio transmission.
This is about the phenomenon of loss of signal in telecommunications.Fading refers to the
time variation of the received signal power caused by changes in the transmission medium or path.
This ppt contains information about concepts of wireless communication, signal propagation effects, spread spectrum, cellular systems, multiple access systems.
Indoor propagation is necessary where outdoor propagation don't work perfectly like house, buildings, sports arena. Different material is used in different types of building then signal doesn't propagate as well as in outdoor. So There are different models for different Scenarios due to different environment, wall, etc.
MIMO radar is introduced in presentation ,its advantage .future scope,research area.
MIMO radars represent a new generation of radars. In contrast to the traditional phased-array radar in which the transmit elements can transmit only the scaled versions of same signal, a MIMO radar allows the transmitters to transmit multiple signals. This waveform diversity offers enhanced flexibility in transmit beampattern synthesis which is an important area of MIMO radar signal processing
Loss of strength, A periodic reduction in the received strength of a radio transmission.
This is about the phenomenon of loss of signal in telecommunications.Fading refers to the
time variation of the received signal power caused by changes in the transmission medium or path.
This ppt contains information about concepts of wireless communication, signal propagation effects, spread spectrum, cellular systems, multiple access systems.
Indoor propagation is necessary where outdoor propagation don't work perfectly like house, buildings, sports arena. Different material is used in different types of building then signal doesn't propagate as well as in outdoor. So There are different models for different Scenarios due to different environment, wall, etc.
MIMO radar is introduced in presentation ,its advantage .future scope,research area.
MIMO radars represent a new generation of radars. In contrast to the traditional phased-array radar in which the transmit elements can transmit only the scaled versions of same signal, a MIMO radar allows the transmitters to transmit multiple signals. This waveform diversity offers enhanced flexibility in transmit beampattern synthesis which is an important area of MIMO radar signal processing
Determination of Propagation Path Loss and Contour Map for FUTA FM Radio Fede...IOSR Journals
Abstract: FM signal propagation through the troposphere interacts with the terrain as obstacles and reflection planes. To understand the degree of interaction, signal strength measurements of the 93.1MHz frequency modulated Radio located at Federal University of Technology; Akure, Nigeria was carried out in the area surrounding the station. The paper reviews the various models for predicting transmission loss and employed the long rice irregular terrain model for its versatility for the study. The losses along the paths were determined and this was compared with the path loss predicted by the irregular terrain model and this was highly correlated. The result offers useful data for developing the contour map of the propagation loss which was developed for the station. It was concluded that with the irregular terrain model predictions can be used for accurate spectrum management in Nigeria. Keywords: Signal Strength, Transmission Loss, Terrain, Spectrum Management.
Determination of Propagation Path Loss and Contour Map for FUTA FM Radio Fede...IOSR Journals
FM signal propagation through the troposphere interacts with the terrain as obstacles and reflection
planes. To understand the degree of interaction, signal strength measurements of the 93.1MHz frequency
modulated Radio located at Federal University of Technology; Akure, Nigeria was carried out in the area
surrounding the station. The paper reviews the various models for predicting transmission loss and employed
the long rice irregular terrain model for its versatility for the study. The losses along the paths were determined
and this was compared with the path loss predicted by the irregular terrain model and this was highly
correlated. The result offers useful data for developing the contour map of the propagation loss which was
developed for the station. It was concluded that with the irregular terrain model predictions can be used for
accurate spectrum management in Nigeria
Hello everyone. This is a short presentation on path loss and shadowing. I have not covered all the topics but a brief idea is given on path loss and wireless channel propagation models.
Hope you find it useful.
Thanks
Path Loss Prediction Model For UHF Radiowaves Propagation In Akure MetropolisCSCJournals
Propagation path loss models play an important role in the design of cellular systems to specify key system parameters such as transmission power, frequency, antenna heights, and so on. Several models have been proposed for cellular systems operating in different environments (indoor, outdoor, urban, suburban, and rural). This work sets out to predict the path loss of a UHF channel along three routes in Akure metropolis using existing models (Friis, Okumura-Hata). Broadcast signal field strength measurements were taken across the three routes. Measured values were compared with the different models prediction to determine model suitable for the city. Consequently, a modified Hata’ model was developed which can be deployed by engineers in radio communications system planning and design.
Impact of Using Modified Open Area Okumura-Hata Propagation Model in Determin...IJMERJOURNAL
ABSTRACT: This paper examines the applicability of the Okumura - Hata model in Malaysia in GSM frequency band. The study was carried out in the open area only since measurements provided from Malaysia Mobile were about the open areas. The mean square error (MSE) was calculated between measured path loss values and those predicted on basis of Okumura-Hata model for an open area. The MSE is up to 6dB, which is an acceptable value for the signal prediction. Therefore, the model gave a significant difference in an open area that allowed necessary changes to be introduced in the model. That error was minimized by subtracting the calculated MSE (15.31dB) from the original equation of open area for Okumura-Hata model. Modified equation was also verified for another cell in an open area in Malaysia and gave acceptable results.
This work measured experimentally, and calculated theoretically using the existing Friis Fomula, the Attenuation of 92.1 MHz (Ajilete FM) Signals along Gambari(Lat 8o291N; Long 4o291) – Oyo-Road(Lat 7o501N; Long 3o561E), Oyo State Nigeria. The two results were compared. The experimental Measurement campaign was achieved by using an appropriate design dipole antenna, well matched to (810 GSP Analyser), to determine the attenuation. The calculated results correlated very well with the measurements (Correlation Coefficient Value R2=1). But, they are not accurate when compared with the measurements (Chi- square values equal zero for received power, measured attenuation). The inaccuracies of the results for the existing formula with the measurements may be due to hills, valleys, trees and bends along the links. Hence the accuracy of the model used can only be effectively confirmed in areas free of the obstacles mentioned above. By applying LEAST SQUARE fit method to the experimental measured data, the analytical models, P(x)= 0.0154x2-1.3575x-38.7620 and A(x)= 0132x2 -1.2464x-104.8487, in the form of polynomial of degree two, were obtained respectively for received power and measured attenuation. The analytical model obtained is therefore recommended for use in an area characterised with bends, valleys, hills and trees, since the model has taken into consideration all these factors. In addition, repeater stations should be installed for effective transmission and for wider coverage in forested and valley areas. Moreover, transmitter of higher value like ten kilowatts should be employed for long distance transmission
Propagation Model for Tree Blockage in Mobile Communication Systems using Uni...IJEEE
A deterministic model for spherical wave propagation in microcellular urban environment is presented. This methodis based on ray tracing and uniform theory of diffraction. The various ray contributions includes the diffraction from corner of obstacle, reflection from ground and direct wave. According to the height of transmitting station, different ray paths will be presented in the received signal. Calculation is carried out using hard and soft polarization. Results can be used for the planning of new cellular system.
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
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Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
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Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
A tale of scale & speed: How the US Navy is enabling software delivery from l...sonjaschweigert1
Rapid and secure feature delivery is a goal across every application team and every branch of the DoD. The Navy’s DevSecOps platform, Party Barge, has achieved:
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Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
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Welocme to ViralQR, your best QR code generator.ViralQR
Welcome to ViralQR, your best QR code generator available on the market!
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Digital class
1. M. Junaid Mughal 2006
Wireless Communications
Principles and Practice
2nd Edition
T.S. Rappaport
Chapter 4: Mobile Radio
Propagation: Large-Scale Path Loss
UMAIR HASHMI Spring 2011
2. M. Junaid Mughal 2006
Reflection from Conductors
A perfect conductor reflects back all the incident wave back.
Ei = Er
Өi = Өr ( E in plane of incidence)
Ei = - Er
Өi = Өr ( E normal to plane of incidence)
UMAIR HASHMI Spring 2011
3. M. Junaid Mughal 2006
Ground Reflection (Two-Ray) Model
UMAIR HASHMI Spring 2011
• Propagation Model that considers both the direct (LOS) path
and a ground reflected path between transmitter and the
receiver.
• Reasonably accurate model for predicting large scale signal
strength over distance of several kilometres.
• The E-field due to Line-Of-Sight is given by ELOS
• The E-field for the ground reflected wave is given by Eg
• The Total E-field is a sum of LOS and Reflected components,
4. M. Junaid Mughal 2006
Ground Reflection (Two-Ray) Model
UMAIR HASHMI Spring 2011
5. M. Junaid Mughal 2006
Ground Reflection (Two-Ray) Model
UMAIR HASHMI Spring 2011
6. M. Junaid Mughal 2006
Ground Reflection (Two-Ray) Model
UMAIR HASHMI Spring 2011
7. M. Junaid Mughal 2006
Ground Reflection (Two-Ray) Model
UMAIR HASHMI Spring 2011
• The path difference between the LOS path and the ground
reflected path is represented by lambda
8. M. Junaid Mughal 2006
Ground Reflection (Two-Ray) Model
UMAIR HASHMI Spring 2011
• The phase difference and the time arrival delay between the
two E-components is given by:
• When d becomes large, difference between d’ and d’’ becomes
negligible and ELOS and Eg could be considered equal in
magnitude
9. M. Junaid Mughal 2006
Ground Reflection (Two-Ray) Model
UMAIR HASHMI Spring 2011
10. M. Junaid Mughal 2006
Ground Reflection (Two-Ray) Model
UMAIR HASHMI Spring 2011
• Now sin(Ө) is approximately equal to Ө when Ө < 0.3 radians.
11. M. Junaid Mughal 2006
Ground Reflection (Two-Ray) Model
UMAIR HASHMI Spring 2011
• The received power Pr and Path Loss PL will be given by:
13. M. Junaid Mughal 2006
Ground Reflection (Two-Ray) Model
UMAIR HASHMI Spring 2011
Example
A mobile is located 5 km away from a BS and uses vertical
lambda/4 monopole antenna with gain of 2.55 dB to receive
cellular signals. The E-field at 1 km from the transmitter is
measured to be 10-3 V/m. The carrier frequency is 900 MHz.
a) Find length and gain of receiving antenna
b) Find receiver power at the mobile using 2-ray ground
reflection model assuming height of transmitting antenna is
50m and receiving antenna is 1.5 m.
14. M. Junaid Mughal 2006
Diffraction
UMAIR HASHMI Spring 2011
• Diffraction is a process that allows radio signals to propagate
around curved surfaces and objects and to propagate behind
obstructions.
Visible Region
Shadow Region
Obstruction
15. M. Junaid Mughal 2006
Diffraction geometry
UMAIR HASHMI Spring 2011
16. M. Junaid Mughal 2006
Diffraction geometry
UMAIR HASHMI Spring 2011
Visible Region
Shadow Region
Obstruction
17. M. Junaid Mughal 2006
Contribution of Huygen’s Secondary
Sources at the Receiver
UMAIR HASHMI Spring 2011
Obstruction
Tx
Rx
18. M. Junaid Mughal 2006
Fresnel Zone Geometry
UMAIR HASHMI Spring 2011
• A transmitter and receiver separated in free space.
• An obstructing screen of height h is placed at a distance d1
from the transmitter and d2 from the receiver.
• The difference between the direct path and the diffracted path
is called the excess path length Δ. Assuming h << d1,d2 and
h>>λ
19. M. Junaid Mughal 2006
Fresnel Zone Geometry
UMAIR HASHMI Spring 2011
20. M. Junaid Mughal 2006
Fresnel Zone Geometry
UMAIR HASHMI Spring 2011
• Now tan x is approximately equal to x for x < 0.5 radians
• Fresnel – Kirchoff Diffraction Parameter v is given by
21. M. Junaid Mughal 2006
Fresnel Zone Geometry
UMAIR HASHMI Spring 2011
• The phase difference between LOS and diffracted path is a
function of
i) Height and Position of the obstruction
ii) Transmitter and Receiver Location
FRESNEL ZONES
• Fresnel Zones represent successive regions where secondary
waves have a path length from the transmitter to the receiver
which are nλ/2 greater than the total path length of a LOS path
The successive concentric circles on the plane have path length
increment by λ/2. The successive circles are called Fresnel
Zones and successive Fresnel Zones have the effect of
producing constructive and destructive interference.
22. M. Junaid Mughal 2006
Fresnel Zone Geometry
UMAIR HASHMI Spring 2011
• The radius of the nth Fresnel Zone is given by
23. M. Junaid Mughal 2006
Knife-Edge Diffraction Model
UMAIR HASHMI Spring 2011
24. M. Junaid Mughal 2006
Knife-Edge Diffraction Model
UMAIR HASHMI Spring 2011
• The receiver is at point R which is located in the shadowed
region (called Diffraction Zone). The field strength at R is a
vector sum of the fields due to all of the secondary Huygen;s
sources in the plane.
• The Electric Field of a knife edge diffracted wave is
• The Diffraction Gain due to the presence of a knife edge is
given by
25. M. Junaid Mughal 2006
Knife-Edge Diffraction Model
UMAIR HASHMI Spring 2011
26. M. Junaid Mughal 2006
Fresnel Zone Geometry
UMAIR HASHMI Spring 2011
• The Diffraction Gain for different values of v is:
27. M. Junaid Mughal 2006
Knife-edge diffraction loss
(Summing Secondary Sources)
UMAIR HASHMI Spring 2011
-3 -2 -1 0 1 2 3 4 5
-30
-25
-20
-15
-10
-5
0
Fresnel Diffraction Parameter v
KnifeEdgeDiffractionGain(dB)
28. M. Junaid Mughal 2006
Fresnel Zone Geometry
UMAIR HASHMI Spring 2011
EXAMPLE
Compute the diffraction loss for the three cases in fig. when
λ=1/3m, d1=1km, d2=1km and (a) h=25m, (b) h=0 (c) h= -25m.
Compare the answers with the values obtained from the graph.
29. M. Junaid Mughal 2006
Fresnel Zone Geometry
UMAIR HASHMI Spring 2011
EXAMPLE
Determine (a) Loss due to knife-edge diffraction and (b) the height
of the obstacle required to induce 6 dB diffraction loss.
Assume f = 900MHz
30. M. Junaid Mughal 2006
Scattering
UMAIR HASHMI Spring 2011
• When a wave impinges on a rough surface, the reflected wave
is spread out (diffused) in all directions due to scattering.
• The dimensions of the objects inducing Scattering are
comparable to λ
• To judge if a surface is smooth or rough (if we will have
reflection or scattering) when a wave impinges upon that
surface, the Critical Height hc is given by
hc = λ / ( 8 sin Өi)
• If maximum protuberance hmax < hc : Smooth Surface
hmax > hc : Rough Surface
• The reflected E-Fields for h > hc is given by :
31. M. Junaid Mughal 2006
Radar Cross Section Model
(RCS Model)
UMAIR HASHMI Spring 2011
• The Radar Cross Section (RCS) of a scattering object is
defined as the ratio of the power density of the signal scattered
in the direction of the receiver to the power density of the radio
wave incident upon the scattering object.
• The bistatic radar equation is used to compute the
propagation of a wave travelling in free space that impinges on
a distant scattering object and then reradiated in the direction
of the receiver. The objects are assumed to be in the Far-Field
region (Fraunhofer region)
PR (dBm) = PT (dBm) + GT (dBi) + 20 log λ + RCS [dB m2 ] – 30
log (4 pi) – 20 log dT – 20 log dR
32. M. Junaid Mughal 2006
Radar Cross Section Model
(RCS Model)
UMAIR HASHMI Spring 2011
33. M. Junaid Mughal 2006
SUMMARY
UMAIR HASHMI Spring 2011
• What is Large Scale Path Loss?
• Free space Propagation Model
• Friis Free space propagation model
• Relating power to Electric field
• The three Basic Propagation mechanisms
• Reflection
•Reflection coefficients
•Polarization rotation
•Brewster angle
•Reflection from perfect conductors
• Ground Reflection (Two Ray Model)
34. M. Junaid Mughal 2006
SUMMARY
UMAIR HASHMI Spring 2011
• Diffraction
• Fresnel Zone Geometry
• Knife Edge Diffraction
• Multiple Knife edge Diffraction
• Scattering
• Rough Surface Scattering
• Radar Cross section
Now we know all the propagation mechanisms and can use
them to predict path loss in any environment
35. M. Junaid Mughal 2006
Log-Distance Path Loss
Model
UMAIR HASHMI Spring 2011
• Radio Propagation Models
• Log-distance Path Loss Model
• Received Power decreases logarithmically with distance,
whether in outdoor or indoor radio channels
• Reference distance should be in the far field region of the
antenna
36. M. Junaid Mughal 2006
Log-Distance Path Loss
Model
UMAIR HASHMI Spring 2011
37. M. Junaid Mughal 2006
Log-Normal Shadowing
UMAIR HASHMI Spring 2011
• Surrounding environment clutter not considered in previous
model.
• Received power can vary at quite a significant value at 2
points having same T-R separation distances.
• Path Loss (PL) is random and distributed log-normally about
the mean distance-dependent value.
38. M. Junaid Mughal 2006
Log-Normal Shadowing
UMAIR HASHMI Spring 2011
• Log-Normal distribution describes the random shadowing
effects which occur over a large number of measurement
locations which have the same T-R separation distance.
• This phenomenon is called the log-normal shadowing. Implies
that measured signal levels at specific T-R separation have a
Gaussian (normal) distribution about the distance-dependent
mean.
39. M. Junaid Mughal 2006
Log-Normal Shadowing
UMAIR HASHMI Spring 2011
40. M. Junaid Mughal 2006
Log-Normal Shadowing
UMAIR HASHMI Spring 2011
41. M. Junaid Mughal 2006
Determination of Percentage
of Coverage Area
UMAIR HASHMI Spring 2011
• The percentage of useful service area i.e. the percentage of
area with a received signal level that is greater or equal to a
threshold value.
42. M. Junaid Mughal 2006
Determination of Percentage
of Coverage Area
UMAIR HASHMI Spring 2011
43. M. Junaid Mughal 2006
Determination of Percentage
of Coverage Area
UMAIR HASHMI Spring 2011
44. M. Junaid Mughal 2006
Determination of Percentage
of Coverage Area
UMAIR HASHMI Spring 2011
45. M. Junaid Mughal 2006
Determination of Percentage
of Coverage Area
UMAIR HASHMI Spring 2011
46. M. Junaid Mughal 2006
Determination of Percentage
of Coverage Area
UMAIR HASHMI Spring 2011
47. M. Junaid Mughal 2006
Determination of Percentage
of Coverage Area
UMAIR HASHMI Spring 2011
48. M. Junaid Mughal 2006
Outdoor Propagation Models
Longley Rice Model
UMAIR HASHMI Spring 2011
• Point to point communication
• 40 MHz to100 GHz
• Different kinds of terrain
• Median Tx loss predicted by path geometry
of terrain profile & Refractivity of
troposphere
• Diffraction losses predicted by?
• Geometric losses by?
49. M. Junaid Mughal 2006
Outdoor Propagation Models
Longley Rice Model
UMAIR HASHMI Spring 2011
• Operates in 2 modes
• Point-to-point mode
• Area mode prediction
• Modification
• Clutter near receiver
• Doesn’t determine corrections due to
environmental factors
50. M. Junaid Mughal 2006
Outdoor Propagation Models
Durkin’s Model
UMAIR HASHMI Spring 2011
• Computer simulator described for field strength contours of
irregular terrain
• Split into 2 parts, first reconstructs radial path profile &
second calculates path loss
• Rx can move iteratively to establish contour
• Topographical database can be thought of as 2-
dimensional array
• Each array element corresponds to a point on map &
elevation
• Radial path may not correspond to discrete data points
thus interpolation
51. M. Junaid Mughal 2006
2-D Propagation Raster Model
UMAIR HASHMI Spring 2011
52. M. Junaid Mughal 2006
Representing Propagation
UMAIR HASHMI Spring 2011
53. M. Junaid Mughal 2006UMAIR HASHMI Spring 2011
• Height reconstructed by diagonal, vertical &
horizontal interpolation methods
• Reduced to 1 D
• Now determine whether LOS – difference
btw heights and line joining Tx & Rx
• Positive height difference
54. M. Junaid Mughal 2006
Algorithm for LOS
UMAIR HASHMI Spring 2011
55. M. Junaid Mughal 2006UMAIR HASHMI Spring 2011
• Then checks first Fresnel Zone clearance
• If terrain profile fails first Fresnel Zone
Clearance
• a) non LOS
• b) LOS but inadequate Fresnel Zone
Clearance
56. M. Junaid Mughal 2006
Non-LOS Cases
UMAIR HASHMI Spring 2011
• a) Single Diffraction Edge
• b) Two Diffraction Edges
• a) Three Diffraction Edges
• a) More than three Diffraction Edges
• Method sequentially tests for each
• Angles btw pine joining Tx & Rx and each point on
reconstructed profile. Max angle (di,hi)
• Angles between line joining Tx & Rx and Tx Antenna to every
point on reconstructed profile
• For single diffraction di=dj
57. M. Junaid Mughal 2006
Multiple Diffraction
Computation
UMAIR HASHMI Spring 2011
58. M. Junaid Mughal 2006
Okumura’s and Hata’s Model
UMAIR HASHMI Spring 2011
59. M. Junaid Mughal 2006
Hata’s Model
UMAIR HASHMI Spring 2011
• Empirical formulation of graphical path loss data
• Valid from 150 MHz to 1500 MHz.
• Urban Area Propagation loss as a standard and supplied
correction equations for application to other situations
• hte=30 m to 200m, hre=1m to 10m
•Compares very closely with Okumura model as long as d
doesn’t exceed 1km
•Well suited for large cell communications but not PCS
60. M. Junaid Mughal 2006
PCS Extension to Hata Model
UMAIR HASHMI Spring 2011
• Hata’s model to 2GHz
61. M. Junaid Mughal 2006
ASSIGNMENT
UMAIR HASHMI Spring 2011
Review the Outdoor Propagation Models
presented in the slides showing their salient
features and how they differentiate from
each other.