Fresh Field Mtc 002 Section 1

8/9/2019 Fresh Field Mtc 002 Section 1

1/85

RadioPropagationSection One

Propagation Phenomena


2/85

2001 Freshfield Communications Limited.Company Confidential Slide 2

The Mobile Radio ChannelThe Mobile Radio Channel Multipath Fading

Shadow Fading

Pathloss

Major Propagation ModelsMajor Propagation Models

Free-space and Plane-earth Equations

Okumura, Hata, RACE COST231 Hata

Diffraction Methods

Clutter Classification

MTCs Propagation ModelMTCs Propagation Model

Presentation OutlinePresentation Outline


3/85


At the end of this course, attendees will:At the end of this course, attendees will: Have an appreciation of radio propagation phenomena

Understand prediction methods for macrocells

Understand MTCs radio propagation model

ObjectivesObjectives


4/85


BTS

The Mobile Radio Propagation ChannelThe Mobile Radio Propagation Channel

MS

The radio channel


5/85


Microwave Frequency

2/3 GHz to Above 30 GHz

LOS Only


The radio channel


6/85



The radio channel

FrequencyDistance Terrain

Weather

Base & Mobile

Antenna

Height

Clutter /

Trees /

Waters


7/85

2001 Freshfield Communications Limited.

Company Confidential

The Mobile Radio ChannelThe Mobile Radio Channel

The mobile radio channel can be characterised by threeThe mobile radio channel can be characterised by three

distinct signal components:distinct signal components:

Multipath Fading

Shadow Fading

Pathloss


8/85



Multipath FadingMultipath Fading



9/85



Slide 9

Wallreflectedra

y

LOSrayGroundreflectedray

Multipath Effects and Multipath FadingMultipath Effects and Multipath Fading


10/85



Slide 10

Multipath fading arises as a result of the followingMultipath fading arises as a result of the followingphenomena:phenomena:

Reflection

Scattering

Refraction

Diffraction



11/85



Slide 11

Rough Surface

Reflection and ScatteringReflection and Scattering


12/85



Slide 12

Positive and Negative

Reinforcement

Refraction and DiffractionRefraction and Diffraction


13/85



Multipath fading has the following characteristics:Multipath fading has the following characteristics: It is caused by the arrival of radio waves from different

directions with different time delays which combine at the

receiver both constructively and destructively (Multipath).

Fades occur every half-wavelength. For a GSM900 system,fades occur every 17 cm and for a GSM 1800 system fades

occur every 8 cm.

The fading rate is governed by the speed of the receiver in

relation to the transmitter.

Fades of a depth of 20 dB are frequent but deeper fades are

common.



14/85



Rayleigh FadingRayleigh Fading


15/85



Multipath fading signals cannot be describedMultipath fading signals cannot be describeddeterministically, but statisticallydeterministically, but statistically

Multipath fading can be:Multipath fading can be:

Rayleigh distributed - non-line of sight (NLOS) regions

Rician distributed - line of sight (LOS) and NLOS regions

Nakagami distributed - LOS and NLOS regions

Weibull distributed - LOS and NLOS regions

Multipath Fading (Contd.)Multipath Fading (Contd.)


16/85



Fading gives rise to speech quality problems in bothFading gives rise to speech quality problems in bothanalogue FDMA and GSM systemsanalogue FDMA and GSM systems

The effects of multipath fading are combatted in GSMThe effects of multipath fading are combatted in GSM

systems using:systems using:

Base station receiver spatial, polarisation or angle diversity

Forward error correction coding techniques

Frequency hopping

Multipath Fading (Contd.)Multipath Fading (Contd.)


17/85



Slide 17

Combiner BTS

RxxP

Solving Multipath ProblemsSolving Multipath Problems -- DiversityDiversity


18/85



Slide 18

Coder

Error

Protection

0

0

1

1

0

11

0

1

0

1

10

1

0

0

1

01

1

1

00

Tx Rx

1

0

1

1

1

11

0

1

0

1

11

1

0

Decoder

Error

Detect

And

Correct

0

1

01

1

1

00

Solving Multipath ProblemsSolving Multipath Problems -- FEC CodingFEC Coding


19/85



Slide 19

Radio Tx/Rx

Time

Solving Multipath ProblemsSolving Multipath Problems -- SFHSFH


20/85




Shadow FadingShadow Fading


21/85



Shadow fading has the following characteristics:Shadow fading has the following characteristics: It accounts for the variation in the overall mean signal level

which are the result of gross variations in the terrain and

building structures between the transmitter and receiver

It cannot be characterised deterministically; however, it can becharacterised statistically

It is modelled using the log-normal statistical distribution,

characterised by a given mean level and a given standard

deviation

Typically, the log-normal standard deviation varies between 6

dB (dense urban areas) and 12 dB (sub-urban and rural areas)

LongLong--term or Shadow Fadingterm or Shadow Fading


22/85



Shadow Fading (Contd.)Shadow Fading (Contd.)


23/85



Slide 23

Shadow FadingShadow Fading

High signal Low signal High signal


24/85



In radio network planning, the longIn radio network planning, the long--term fading is takenterm fading is takeninto account by including a fading margin which dependsinto account by including a fading margin which depends

upon:upon: Coverage criterion chosen by the network operator e.g. 90% on-street

coverage in urban areas Log-normal standard deviation e.g. 8.2 dB


Log-normal

standard

deviation

Area probability


25/85



In radio network planning, the longIn radio network planning, the long--term fading is takenterm fading is takeninto account by including a fading margin which dependsinto account by including a fading margin which depends

upon:upon: Coverage criterion chosen by the network operator e.g. 90% on-street

coverage in urban areas Log-normal standard deviation e.g. 8.2 dB


Calculated edge

probability

Calculated

fading margin

used for design


26/85




Calculated

fading margin

Used in link

budget analysis

to calculate

isotropic RX

level


27/85




PathlossPathloss


28/85



Pathloss accounts for the degradation in measuredPathloss accounts for the degradation in measuredsignal level at the receiver when the effects of multipathsignal level at the receiver when the effects of multipath

and shadow fading are removed.and shadow fading are removed.

Pathloss characteristics:Pathloss characteristics:

Pathloss increases with distance and frequency

Pathloss decreases with base and mobile antenna heights

Pathloss is affected by the presence of vegetation and other

land cover effects (clutter), terrain effects (diffraction), street

orientation and weather seasonal conditions

Pathloss is affected by the transmission condition, whether line-

of-sight, partial-line-of-sight or non-line-of-sight

Pathloss in-buildings is affected by building wall materials

PathlossPathloss


29/85



Pathloss (Contd.)Pathloss (Contd.)


30/85



Slide 30

Pathloss PredictionPathloss Prediction

Pathloss prediction models are employed to predict thePathloss prediction models are employed to predict the

pathloss between given transmitter and receiver locationspathloss between given transmitter and receiver locations

for:for:

cell coverage Interference dimensioning from co-channel cells


31/85



Slide 31

Macro Cell

Mini Cell

Macro Cell

Pico Cell Pico Cell

Pathloss prediction depends upon cell typePathloss prediction depends upon cell type

Macrocells cells, Antenna are

mounted well above rooftops of

surrounding buildings, with

coverage of up to 5km.

Minicells cells, Antennas are

mounted at heights comparable

to building rooftops, with

coverage of 2km.

Micro Cell

Microcells cells, Antennas are

mounted at heights as low as 5-

10m, with coverage of 500m.

Picocells CoverageAntennas are

mounted inside the building.


32/85



Slide 32

Macrocell ModellingMacrocell Modelling

Widely used models in the wireless industry include:Widely used models in the wireless industry include: Free-space

Plane-Earth

Okumura

Hata

COST231 Hata

Other important parameters:Other important parameters:

Knife-edge diffraction techniques

Rounded Hill Diffraction techniques

Clutter statistical loss

Calculation of effective base and mobile antenna heights


33/85



Macrocell Modelling (Contd.)Macrocell Modelling (Contd.)

Common to some or all of the models listed are theCommon to some or all of the models listed are theinclusion of some or all of these parameters:inclusion of some or all of these parameters:

Distance (d) dependence in the form of 10nlog d where n is the pathloss

factor e.g. 2.0 for free space and 4.0 for plane earth.

Frequency (f) dependence in the form of Kf logf where Kf is a multiplying

coefficient.

Base (hb) and mobile (hm) antenna height dependence in the form of Khlog hb or Kh log hb log d or log hm where Kh is a multiplying factor.

Diffraction, taking effects of terrain into account both as knife-edges and

rounded hills.

Clutter effects, with correction factors specified for urban, sub-urban,

rural and open areas.


34/85



Slide 34

BTS

FSL=32.4+20log10D+20log10FFSL=Free Space Loss (dB)

D=Distance from cell site (km)

F=Transmit Frequency (MHz)

Free Space EquationFree Space Equation


35/85



Slide 35

Plane Earth EquationPlane Earth Equation

BTS

Base

station

height Hb

PEL=40log10D+20log10F-20log10HbHmPEL=Plane Earth Loss (dB)

D=Distance from cell site (km)

F=Transmit Frequency (MHz)

Hb=Base station height (m)

Hm=Mobile station height (m)


36/85



Okumuras ModelOkumuras Model

Recognised limitations of free space and plane earthRecognised limitations of free space and plane earthmodelsmodels

In 1968 he started his relatively comprehensiveIn 1968 he started his relatively comprehensive

measurement campaign in Tokyo. He performedmeasurement campaign in Tokyo. He performed

measurements at different:measurements at different: Frequencies

Base station and mobile antenna heights

Distances

Environment (Clutter and Terrain)

Street Orientation


37/85




The basic formulation of the model is:The basic formulation of the model is:

wherewhereL50 is the median pathloss value

Lf is the free space pathloss value

Amu is the median attenuation relative to free space in a quasi-smooth urban

terrain

Htu is the base station antenna height gain

Hru is the vehicular antenna height gain factor

The exact values for a given set of transmission conditionsThe exact values for a given set of transmission conditions

are derived from graphs.are derived from graphs.

L L A H H , dB F mu tu ru50 !


38/85




Additional correction factors deduced for:Additional correction factors deduced for: street orientation

transmission conditions in suburban and open areas

transmission over irregular terrain such as rolling hilly terrain,isolated mountain, general sloping terrain and mixed land-sea

paths

Okumura has explicitly explained how his model can beOkumura has explicitly explained how his model can be

developed from the graphs.developed from the graphs.


39/85



Okumuras Model (Contd.)Okumuras Model (Contd.)


40/85



Okumuras Model (Contd.)Okumuras Model (Contd.)


41/85



Okumuras Model ApplicabilityOkumuras Model Applicability

Okumuras model is applicable over the following ranges:Okumuras model is applicable over the following ranges:

The model has been developed specifically for use in Japan.The model has been developed specifically for use in Japan.

In addition, the manual use of the graphs makes the modelIn addition, the manual use of the graphs makes the model

somewhat complicated.somewhat complicated.

1 0 0 3 0 0 0

3 0 1 0 0 0

1 1 0 0

f M z

h

d k

c

b

e e

e e

e e


42/85



Hata established empirical mathematical relationships fromHata established empirical mathematical relationships fromOkumuras graphs. The basic model for urban areas is givenOkumuras graphs. The basic model for urban areas is given

as:as:

wherewhere a(ha(hmm)) is the correction factor for mobile antennais the correction factor for mobile antenna

height. For a small or mediumheight. For a small or medium--sized city,sized city, a(ha(hmm) ) is computedis computed

as follows:as follows:

L . . f ( . . h ) d . h a(h )urban c b b m50 6955 2616 449 655 1382, log log log log!

a(h ) ( . f . )h ( . f . )m c m c! 11 0 7 156 0 8log log

Hatas ModelHatas Model


43/85



For a large city,For a large city, a(ha(hmm)) is computed as follows:is computed as follows:

Suburban Areas PathlossSuburban Areas Pathloss

Open Areas PathlossOpen Areas Pathloss

LdB

L (urban) [ (f c / )] .

50 502 28 2 5 4

,log!

L dB L (urban) . [ f c ] . f c .5 0 5 0 4 78 2 18 33 40 94, log log!

a(h ). ( . h ) . f M z

. ( . h ) . f M z!

e

u

8 29 154 2 11 200

3 2 1175 2 4 97 400

log

log



44/85



Slide 44

F=Transmit Frequency (MHz) Range 150-1500hb=BTS Antenna Height (m) Range 30-200

hm=MS Antenna Height (m) Range 1-10 D=Distance from Cell Site (km) Range 1-20

Example: F=880MHz hb =30m hm =1.5m

150.79150.79122.37122.37105.27105.2755

147.37147.37118.96118.96103.33103.3344

142.97142.97114.56114.56100.83100.8333

136.77136.77108.36108.3697.3197.3122

126.16126.1697.7597.7591.2991.2911

Hata UrbanHata UrbanHata OpenHata OpenFree SpaceFree Space

Path Loss (dB)Path Loss (dB)DistanceDistance

(km)(km)



45/85



Comparison With MeasurementsComparison With Measurements


46/85



COST231COST231--Hata ModelHata Model

The COST231The COST231--Hata model has been developed in order toHata model has been developed in order toextend the range of applicability of the Hata model toextend the range of applicability of the Hata model to

2000MHz. The basic formulation is as follows:2000MHz. The basic formulation is as follows:

CCmm = 0 dB for medium sized cities and suburban centres with= 0 dB for medium sized cities and suburban centres with

moderate tree densitymoderate tree densityCCmm = 3 dB for metropolitan centres= 3 dB for metropolitan centres

L . . f . hb a(h ) . . hb d C50 46 3 33 9 13 82 44 9 6 55! log log log log


47/85



Slide 47

166.01166.01150.79150.79105.27105.2755

162.33162.33147.37147.37103.33103.3344

157.58157.58142.97142.97100.83100.8333

150.89150.89136.77136.7797.3197.3122

139.45139.45126.16126.1691.2991.2911

Cost231Cost231Hata UrbanHata UrbanFree SpaceFree Space

Path Loss (dB)Path Loss (dB)DistanceDistance

(km)(km)

180

160

140

120

100

80

60

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 2 3 4 5

Dist (km)

P

th

ss

(dB)

Free Space

Hata Open

Hata Urban

Cost231

ModelComparisonModelComparison


48/85



DiffractionDiffraction

Takes into account effects of terrain not modelled inTakes into account effects of terrain not modelled instandard equationsstandard equations

Studied by several researchers including Bullington,Studied by several researchers including Bullington,

Edwards, Durkin, Deygout, Giovanelli, Causebrook andEdwards, Durkin, Deygout, Giovanelli, Causebrook and

many othersmany others All these researchers were aiming to explain propagationAll these researchers were aiming to explain propagation

in terms of:in terms of:

Path loss = Path Loss due to FreePath loss = Path Loss due to Free--space + Diffraction valuespace + Diffraction value


49/85



Slide 49

DiffractionDiffraction

Low signalBuilding

diffracted

signal

Hilltop

diffracted

signal


50/85



Two techniques are available:

Knife-edge diffraction methods

Rounded-hill diffraction methods

Diffraction ModellingDiffraction Modelling


51/85



Estimation of diffraction loss involves the calculation of theEstimation of diffraction loss involves the calculation of theFresnelFresnel--Kirchhoff diffraction parameter:Kirchhoff diffraction parameter:

The diffraction loss can be calculated using the curve shownThe diffraction loss can be calculated using the curve shown

below.below.

RP

!

hd d

d d

1 2

1 2

0 5.

Single KnifeSingle Knife--Edge DiffractionEdge Diffraction


52/85



Slide 52

Multiple KnifeMultiple Knife--Edge DiffractionEdge Diffraction

Multiple

knife-edges


53/85



Multiple KnifeMultiple Knife--Edge Diffraction TechniquesEdge Diffraction Techniques

Methods for multiple knifeMethods for multiple knife--edge diffraction calculationedge diffraction calculationinclude:include:

Bullington

Epstein-Peterson

Japanese Deygout

Giovanelli


54/85



Bullingtons MethodBullingtons Method

Was published in 1947Was published in 1947 Is based on the principle that a real terrain profile withIs based on the principle that a real terrain profile with

more than one knifemore than one knife--edge is represented by a singleedge is represented by a single

equivalent knifeequivalent knife--edgeedge Diffraction loss is underDiffraction loss is under--estimated because importantestimated because important

obstacles could be ignoredobstacles could be ignored


55/85



The diffraction loss is computed asThe diffraction loss is computed as

d! ! da f d d h h( , , )1 2

Bullingtons MethodBullingtons Method


56/85



EpsteinEpstein--Peterson MethodPeterson Method

Was published in 1952Was published in 1952 Is based on measurements conducted at 850 MHzIs based on measurements conducted at 850 MHz

Evaluates the diffraction loss as the sum of attenuationsEvaluates the diffraction loss as the sum of attenuations

due to each knifedue to each knife--edge in turnedge in turn


57/85



EpsteinEpstein--Peterson Method (Contd.)Peterson Method (Contd.)


58/85



EpsteinEpstein--Peterson Method (Contd.)Peterson Method (Contd.)

The total diffraction loss is given by the following equation:The total diffraction loss is given by the following equation:

wherewhere

andand

This method underestimates the diffraction loss.This method underestimates the diffraction loss.

a a ad B, ! 1 2

a f d d hM d1 1 2, ( , , )!

a f d d hM d2 2 3,

! ( , , )


59/85



Deygout MethodDeygout Method

Was published by the French Signal School in 1959Was published by the French Signal School in 1959 Was verified at 160, 1800, 1850 and 2450 MHzWas verified at 160, 1800, 1850 and 2450 MHz

Total diffraction loss is evaluated as the sum of lossesTotal diffraction loss is evaluated as the sum of losses

over all obstacles in order of decreasing influenceover all obstacles in order of decreasing influence

Loss for each diffracting edge is evaluated in turn as if theLoss for each diffracting edge is evaluated in turn as if the

remaining edges were absentremaining edges were absent


60/85



Deygout Method (Contd.)Deygout Method (Contd.)


61/85



Deygout Method (Contd.)Deygout Method (Contd.)

The component diffraction losses are calculated asThe component diffraction losses are calculated asfollows:follows:

M3 is a subM3 is a sub--path obstacle and sopath obstacle and so

The total diffraction loss is therefore given by:The total diffraction loss is therefore given by:

a f d d h hM 1 1 2 1! ! d( , , )

a f d d d d d h hM 2 1 2 3 4 5 2! !( , , )

a f d d h hM 3 3 4 3! ! d( , , )

L a i mD ii

! ! 1-

a f d d d h h4 3 4 5 4! ! d( , , )


62/85



Slide 62

Rounded Hill DiffractionRounded Hill Diffraction

Hills are

not knife-

edges!!!

Rounded hills


63/85



Why include rounded hill loss?Why include rounded hill loss?

Real Real--world terrain profiles usually consist of hills with aworld terrain profiles usually consist of hills with adefined curvaturedefined curvature

The treatment of rounded obstacles as knifeThe treatment of rounded obstacles as knife--edges canedges can

lead to large errors in field strength predictionlead to large errors in field strength prediction


64/85



Rounded Hill Loss ModellingRounded Hill Loss Modelling

Two well-known methods: Hackings method

Causebrooks method


65/85



Originally in graphical form, it has been reduced to equationOriginally in graphical form, it has been reduced to equationform by Parsons, thus:form by Parsons, thus:

LLexex is the additional loss in dB which must be added to theis the additional loss in dB which must be added to the

loss computed using a knifeloss computed using a knife--edge diffraction technique.edge diffraction technique. RR

represents the estimated radius which will be derived fromrepresents the estimated radius which will be derived fromthe terrain profile.the terrain profile.

L Rex dB, /. ( / )! 11 7 1 3U T P

Hackings FormulaHackings Formula


66/85



Causebrooks Rounded Hill FormulationCausebrooks Rounded Hill Formulation

Approximation to Dougherty and Maloneys analysis.Approximation to Dougherty and Maloneys analysis.The diffraction loss is given by:The diffraction loss is given by:

wherewhere vv is the Fresnel parameter for an equivalent knifeis the Fresnel parameter for an equivalent knife--

edge andedge and pp is the index of curvature given by:is the index of curvature given by:

RR is the radius of curvature of the hill and dis the radius of curvature of the hill and d11 and dand d22are theare the

distances from the terminals in kilometres.distances from the terminals in kilometres.

A A A U ( , ) ( , ) ( , ) ( )R V R V R V! 0 0

VP

T!

1 6

1 3 1 2

1 2

1 2/

/

/

Rd d

d d


67/85



Slide 67

Why use terrain data ?Why use terrain data ? Terrain data is used in the calculation of diffraction loss.

Resolution and AccuracyResolution and Accuracy

Terrain data is usually digitised from paper relief maps.

Terrain data is usually supplied at resolutions of between 20mand 200m. A resolution of 20-50m is appropriate in urban areas,

while a resolution of 100m is appropriate in desert areas. The

better the resolution of the data, the more accurate the

propagation model. The accuracy of terrain data is between 1 and 3 m. Accuracy

depends on the scale of the source maps e.g. a 1:25000 map

will produce better height data than a 1:500,000 map.

Calculating Diffraction Loss Using TerrainCalculating Diffraction Loss Using Terrain


68/85



Slide 68

Given a

digitalterrain map

Calculating Diffraction Loss Using TerrainCalculating Diffraction Loss Using Terrain

A terrain profile is constructed

between the transmitter and

receiverDiffraction modelling requiresthe use of a terrain database

which has a height value

stored for each pixel.The terrain profile shows

knife-edges between the

transmitter and receiver


69/85



Slide 69

Clutter Land Usage TypesClutter Land Usage Types


70/85



Clutter ClassificationsClutter Classifications

Why employ clutter classifications ?Why employ clutter classifications ? Radio propagation waves are strongly influenced by the nature

of the environment and in particular the size and density of

buildings or clutter

ClassificationsClassifications Different areas are classified on the basis of:

density and heights of buildings

density of vegetation

spacings between buildings, width of roads, etc..

and the importance of the area e.g. business district, dense-urban or

residential

Clutter Classifications are usually specific to each country


71/85



Slide 71

Building LossBuilding Loss

55RuralRural

88SuburbanSuburban

2222UrbanUrban

2727Dense UrbanDense Urban

2525Very DenseVery Dense

2020DenseDense

1515MediumMedium

1010LightLight

66SparseSparse

FoliageFoliage

Loss, dBLoss, dBEnvironmentEnvironment

Clutter AttenuationClutter Attenuation


72/85



Slide 72

Clutter databases are generated using:

Satellite imagery

Street maps

Local visits to the area of interest

Building height information can be derived from stereographic satellite

images using correlation methods.

Acquisition of Clutter DataAcquisition of Clutter Data


73/85



Slide 73

Okumuras Clutter ClassificationOkumuras Clutter Classification

Code Clutter Category Description

0 Open Area No obstacles such as trees and buildingsin the propagation path and a plot of landwhich is clear for 300m to 400m ahead

e.g. farmland, rice-fields and open fields1 Suburban Area Comprises a village or a highway

scattered with trees and houses

2 Urban Area Built-up city or large town crowded withlarge buildings and > 2 floor houses or ina larger village closely interspersed withhouses.


74/85



Slide 74

Code Cl tterCategory Descri tion

W Waterarea Incl dessea,lakes and rivers. Small waterareaslike rivers are often parts ofot erland covertypes

O1 Open area Defined to be a place where there arnoobstr ctions usually at a distance of1 km from themobile to the transmitter.there may be otherlandcoverclasses between the base and the mobile.

O2 Open area with someobstructions

Typicalrural area.rural areas have usuallyscattered groups oftrees, buildings, etc. Major

part ofland isstill open field.F1 Low densityforest A forest where there are smalltrees orbushes or

talltrees growing separately. The area isclassified asforest, park orgarden in a generalmap.

F2 Ordinaryforest A forest where mostlyfull grown trees are growingclose together.

S1 Suburban,low density Situated around large cities. The buildingscover

only a small part ofthe land area and are not builtside-by-side.

S2 Suburban low densitywith dense vegetation

The same asthe preceeding class but with densevegetation and high trees.

RACE Clutter ClassificationRACE Clutter Classification


75/85



Slide 75

Code ClutterCategory Descr tion

S3 Suburban area For example, a small provincial town or residentialarea w ich has low buildings (1-3 floors), situatedclose to each other, gardens and parks.

U1 Urban, low density An area where buildings are higher than insuburban but the average height is typically lessthan 5 floors. The land area covered by buildingsis low or moderate. new surroundings and satellitecities often belong to this category.

U2 Urban area Has been chosen to a reference environment.This is the same as Okumuras urban definition.The buildings have on average 5 floors and over10 floor buildings are exceptional. Central parts ofCopenhagen and Helsinki are examples of this

class.U3 Urban areas, city centre Densely built up areas with mostly high buildings,

office towers, etc., The central parts ofAthens,frankfurt and London are typical cases.

RACE Clutter Classification (Contd)RACE Clutter Classification (Contd)


76/85



Effective Antenna Height AlgorithmEffective Antenna Height Algorithm

The effective antenna height for both base and mobile stationThe effective antenna height for both base and mobile station

antennas can be deduced taking into account the effect of the terrainantennas can be deduced taking into account the effect of the terrain

and the height of the terminal above ground.and the height of the terminal above ground.

The available effective antenna height algorithms are:The available effective antenna height algorithms are:

Base Height

Average Height

Height above least-squares fit to terrain

Local or Spot HeightAlmostallalgorithmstakethegroundheightabovemeansealevel

forbothtransmitterandreceiverlocationsintoaccount.


77/85



Effective Antenna HeightEffective Antenna Height

habove,gnd

Base Height is the height of the terminal above groundBase Height is the height of the terminal above groundlevellevel


78/85




Local or Spot Height is estimated using the equation:Local or Spot Height is estimated using the equation:

Hlocalht

h h h h hlocal TX above gnd TX ground TX ground RX ground ! min( , )


79/85




Average Height is obtained from the terrain profileAverage Height is obtained from the terrain profilebetween the transmitter and receiver as:between the transmitter and receiver as:

Havg,ht

Average

terrain

eig t

h hi

i

N

G N D A V G !!

1

Subsequently,theeffectiveantennaheightisobtainedas:h h h hAVG TX above gnd TX ground G ND AVG1 !


80/85




Height Above LeastHeight Above Least--Squares Fit is applied to the terrainSquares Fit is applied to the terrainand subsequently the effective antenna height isand subsequently the effective antenna height is

estimated as:estimated as:

Hlsf,ht

Least-

square fit

to terrain

h h h h hLSF TX above GND TX ground TX ground LSF ground at TX ! min( , )


81/85




Two propagation models are used in MTC:Two propagation models are used in MTC: New_Clutter_Model_City - for All city areas including Sharq,

Bneid Al-Gar, Dasman, Khladiya, etc.

New_Clutter_Model_Wafra - for the Wafra area

The models employed by MTC are of the form:The models employed by MTC are of the form:

factor_Clutter+m

h10

log040.0+nDiffractio694.0

bh

10log5.1+d

10log

bh

10log8.3+d

10log6.359.25

TXP=

RXP

-

--

factor_Clutter+m

h10

log040.0+nDiffractio694.0bh10log5.1+d10logbh10log8.2+d10log379.25TXP=RXP

---


82/85




Derived using propagation measurements conducted atDerived using propagation measurements conducted at870.3 MHz870.3 MHz

RMS Error of 6.9 dB achievedRMS Error of 6.9 dB achieved

Applicable for PApplicable for P--GSM, EGSM, E--GSM and EGSM and E--TACS radio planningTACS radio planning

in the 800in the 800--900 MHz band900 MHz band Not applicable for 1800 MHz radio planningNot applicable for 1800 MHz radio planning

Further details are available in the attached report:Further details are available in the attached report:

Measurement Report for MTC Survey 1997.docMeasurement Report for MTC Survey 1997.doc


83/85



MTCs Clutter FactorsMTCs Clutter Factors

C de ClutterCategory ClutterFa t r

1 CentralBusinessDistri t fLargeCities -2.02 Residential & Sub-ur anAreas 6. 34

3 Industrial 7.

4 Transportation,C mmuni ation & Utilities 12.342

5 i ed Ur anandBuilt-upLand -1.788

6 OtherUr anandBuilt-upLand 0.0

7 Cr plandand Pasture 13.336

8 Orchards, Gr ves, Vineyards 10.329

9 OtherAgri ulturalLand 12.29610 i ed Rangeland 16.258

11-14 Ocean,Streams,Canals,Lakes 24.831

15-16 Reservoirs,Baysand Estuaries 19.278

17 N n-f rested etlands 19.139

18 DrySalt Flats 17.433

19 SandyAreas therthan eaches 17.5

20 i edBarrenLand 12.7

21 Elevated R ads 7.439

22 R ad cutting -0.203

23 High Ur an -3.0

24 IndustrialC mple es 5.5


84/85




Using the MTC model, best server coverage plots can beUsing the MTC model, best server coverage plots can becreated for the entire 900 MHz layer of the network.created for the entire 900 MHz layer of the network.

SS


85/85

2001 F hfi ld C i ti Li it d

The mobile radio channel is made up of multipath fading,The mobile radio channel is made up of multipath fading,shadow fading and pathlossshadow fading and pathloss

Multipath fading is as a result of the arrival of multipleMultipath fading is as a result of the arrival of multiple

signals from various paths due to different phenomenasignals from various paths due to different phenomena

Shadow fading is as a result of large variations in signalShadow fading is as a result of large variations in signalas the mobile moves between buildings and hillsas the mobile moves between buildings and hills

Pathloss describes the distance and frequencyPathloss describes the distance and frequency

dependence of the received signaldependence of the received signal

SummarySummary

Date post:	29-May-2018
Category:	Documents
Upload:	deepak-teena-deep
View:	216 times
Download:	0 times

Fresh Field Mtc 002 Section 1

Documents