fresh field mtc 002 section 2

8/9/2019 Fresh Field Mtc 002 Section 2

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RadioPropagationSection Two

Microcells & In-Building

Prediction


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Slide 22001 Freshfield Communications Limited.Company Confidential

Minicell Prediction MethodsMinicell Prediction Methods Walfisch-Ikegami Model

Microcellular Prediction MethodsMicrocellular Prediction Methods

Empirical

Ray-Tracing

Into and Within Building Prediction MethodsInto and Within Building Prediction Methods

Freshfields measurements in KuwaitFreshfields measurements in Kuwait

Presentation OutlinePresentation Outline


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At the end of this course, attendees will:At the end of this course, attendees will: Understand minicell and microcell propagation

Understand into building and within building propagation

Have an appreciation of building penetration losses measured

in Kuwait

ObjectivesObjectives


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Pathloss Prediction ModelsPathloss Prediction Models

Minicells and MicrocellsMinicells and Microcells

Slide 4


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Minicells and MicrocellsMinicells and Microcells

Mini Cell

Micro Cell

Both microcells and

minicells are usually

introduced to take-up

capacity rather than

just coverage


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Minicell/Microcell Propagation ModellingMinicell/Microcell Propagation Modelling

Minicell / Microcell Prediction can be undertaken usingMinicell / Microcell Prediction can be undertaken usingany one of the following techniques:any one of the following techniques:

Empirical methods

Semi-empirical, Pseudo-ray tracing methods

Ray-tracing methods

Accurate microcell prediction requires:Accurate microcell prediction requires:

Detailed building data at resolution of 1m-5m

Or building polygon outlines

Or road centre-line vectors


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Slide 7

2001 Freshfield Communications Limited.Company Confidential

Minicell/Microcell Propagation PhenomenaMinicell/Microcell Propagation Phenomena

Two effects are visible in microcells:Two effects are visible in microcells: Line-of-sight propagation

Non-line-of-sight propagation

Wallreflected

ray

LOSrayGroundreflectedray

Wall reflected ray

Edge diffracted ray

Edge diffracted ray

MS

BS

NLOS AreasLOS Areas


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Slide 82001 Freshfield Communications Limited.

Company Confidential

Street Canyon Effect in MicrocellsStreet Canyon Effect in Microcells


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Minicell/Microcell Propagation ModellingMinicell/Microcell Propagation Modelling

Empirical TechniquesEmpirical Techniques

WalfischWalfisch--Ikegami COST231 ModelIkegami COST231 Model

Slide 9


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The WalfischThe Walfisch--Ikegami ModelIkegami Model

Adopted by the European research committee COST231Adopted by the European research committee COST231for small cell signal predictionfor small cell signal prediction

Model is semiModel is semi--empirical and is based on the theoreticalempirical and is based on the theoretical

approaches of Walfisch and Bertoni and Ikegamiapproaches of Walfisch and Bertoni and Ikegami

Requires more detailed clutter databases which give anRequires more detailed clutter databases which give an

indication of street widths and building heightsindication of street widths and building heights


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WalfischWalfisch--Ikegami Model (Contd.)Ikegami Model (Contd.)

d

MobileBase tation

bw

dhb

hroof

dhm

hm

hb


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Pathloss is obtained for LOS areas as:Pathloss is obtained for LOS areas as:

wherewhere dd represents the distance between antennas (km) andrepresents the distance between antennas (km) andff is the frequency (MHz).is the frequency (MHz).

In NLOS areas, the pathloss is obtained as:In NLOS areas, the pathloss is obtained as:

LLOS

d d f( ) . . log . log! 42 6 26 0 20 0

LNLOS

dL

oL

rtsL

msdL

oif L

rtsL

msd( ) !

e

0


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LLoois the freeis the free--space loss (dB)space loss (dB)LLrtsrts is the roofis the roof--toptop--toto--street diffraction and scatter lossstreet diffraction and scatter loss

LLmsdmsdis the multiis the multi--screen diffraction lossscreen diffraction loss

LLoo is given byis given by

LLrtsrtsis given byis given by

wherewhere ww is the width of the NLOS street (m),is the width of the NLOS street (m), hhmm is the height of theis the height of the

mobile andmobile and dhdhmm is the difference between the average rooftop height,is the difference between the average rooftop height,

hhroofroof, and, and hhmm..

Lo

d f! 32 4 20 20. log log

Lrts

w f dhm

Lori

! 16 9 10 10 20. log log log


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LLorioriis a correction function for street orientation which isis a correction function for street orientation which isgiven as:given as:

The multiThe multi--screen diffraction loss,screen diffraction loss, LLmsdmsd, is determined from, is determined from

the following equation:the following equation:

Lori

for

for

for

!

e e

e

e

10 0 354 0 35

2 5 0 075 35 35 55

4 0 0 114 55 55 90

.

. .

. . ( )

J J

J J

J J

Q Q

Q Q

Q Q

Lmsd

Lbsh

ka

kd

d kf

f b! log log log9



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LLbshbshrepresents the first part of the additional pathloss due to reducedrepresents the first part of the additional pathloss due to reducedbase station antenna height and is given by:base station antenna height and is given by:

in whichin which dhdhbb is the difference between the base antenna height,is the difference between the base antenna height, hhbb, and, and

the average rooftop height,the average rooftop height, hhroofroof.. kkaa is the second part of the additionalis the second part of the additional

pathloss due to reduced base station antenna height. This factor ispathloss due to reduced base station antenna height. This factor is

distance dependent and is given as:distance dependent and is given as:

ka

for hb

hroof

dhb

for d km and hb

hroof

dhb

d for d kmand hb

hroof

!

"

u e

e

54

54 0 8 0 5

54 0 8 0 5 0 5

. .

. / . .

Lbsh

dhb

for hb

hroof

for hb

hroof

! "

e

18 1

0

log( )


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KKddandand KKffare the distance and frequency dependence factorsare the distance and frequency dependence factorsfor the diffraction loss respectively and are given by:for the diffraction loss respectively and are given by:

kd

for hb

hroof

dh

bhroof

for hb hroof

!

"

e

18

18 15

kf

ffor medium sized cities and suburban

centres with er ate tree density

ffor metropoli centres

!

4

0 7925

1

15925

1

.

mod

. tan


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The model is restricted to the following ranges ofThe model is restricted to the following ranges ofapplicabilityapplicability

f 800 - 2000 MHz

hb 4 - 50 m

hm 1 - 3 md 0.02 - 5 km


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SemiSemi--Empirical MethodsEmpirical Methods

The dualThe dual--slope plus corner loss modelslope plus corner loss model


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DualDual--slope plus corner loss modelslope plus corner loss model

BS

Main

Street

Side Street

Parallel

Street

Buildings

Buildings

Fictitious

Transmitter

Linear

Attenuation

Region


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This model predicts path loss in microcell areas by dividing regions intoThis model predicts path loss in microcell areas by dividing regions intolineline--ofof--sight (LOS) and nonsight (LOS) and non--lineline--ofof--sight (NLOS) areas. Pathloss insight (NLOS) areas. Pathloss in

LOS areas is computed using the following two slope formulation:LOS areas is computed using the following two slope formulation:

ddbrkbrk is the breakpoint of pathloss in the LOS streetis the breakpoint of pathloss in the LOS street

LLbb is a basic transmission loss parameteris a basic transmission loss parameter

nn11 is the pathloss factor before the breakpoint andis the pathloss factor before the breakpoint and

nn22 is the pathloss factor after the breakpointis the pathloss factor after the breakpoint

Ld Lbn d for d d

brk

n n dbrk

n d d d brk

!

u

101

101 2

102

log

log log

SemiSemi--Empirical MethodsEmpirical Methods


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In nonIn non--lineline--ofof--sight regions, pathloss is obtained using the followingsight regions, pathloss is obtained using the followingequations:equations:

yybrkbrk is the breakpoint of pathloss in the NLOS streetis the breakpoint of pathloss in the NLOS street

LLbNLOSbNLOS is a basic transmission loss parameteris a basic transmission loss parametermm11 is the pathloss factor before the breakpoint andis the pathloss factor before the breakpoint and

mm22 is the pathloss factor after the breakpointis the pathloss factor after the breakpoint

L d y LLOS

d LNLOS

y( , ) ( ) ( )!

LNLOS

yL

bNLOSm y y y

brkL

bNLOSm m y

brkm y y y

brk( )

log

( ) log log!

e e u

101

1

101 2

102

SemiSemi--Empirical Prediction MethodsEmpirical Prediction Methods


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Microcellular Empirical Prediction MethodsMicrocellular Empirical Prediction Methods

To facilitate prediction using in a radio network planningTo facilitate prediction using in a radio network planningtool, the roadtool, the road--centre line vector layer is usedcentre line vector layer is used

The vector layer is a 2The vector layer is a 2--dimensional grid road network withdimensional grid road network with

all street represented as a series of coordinatesall street represented as a series of coordinates

Roads are divided into LOS and NLOS streetsRoads are divided into LOS and NLOS streets

Pathloss in open areas can also be predicted using aPathloss in open areas can also be predicted using a

dualdual--slope modelslope model


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Microcellular RayMicrocellular Ray--Tracing MethodsTracing Methods

The ray tracing model is an intuitive approach based on the understanding of theThe ray tracing model is an intuitive approach based on the understanding of thepropagation mechanisms in microcells. These mechanisms include:propagation mechanisms in microcells. These mechanisms include:

Direct line-of-sight

Building wall reflections

Building wall diffraction

WhenWhen NN rays are incident on the mobile antenna, the received signal is the vectorrays are incident on the mobile antenna, the received signal is the vectorsum of the fields due to these rays. the received power,sum of the fields due to these rays. the received power, PPRR, is given as:, is given as:

PR PT GbGm

f

bi

f

miri

Cie

jri

ro

i

N

!

-

!

P

T

T

P4

2

2

0

1

2


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Microcellular RayMicrocellular Ray--Tracing MethodsTracing Methods

PPTT represents the power transmitted by the base antennarepresents the power transmitted by the base antennarroo is the distance between the base and mobile antennasis the distance between the base and mobile antennas

rrii is the path length of theis the path length of the iith rayth ray

GGbb is the gain of the base antennais the gain of the base antenna

GGmmis the gain of the mobile antennais the gain of the mobile antenna

ffbb is the base normalised field radiation patternis the base normalised field radiation pattern

ffmmis the mobile normalised field radiation pattern andis the mobile normalised field radiation pattern and

CCiiis a complex valuedis a complex valuedcoefficient associated with thecoefficient associated with the iith ray. For rays which travelth ray. For rays which travel

directly between the transmitter and receiver,directly between the transmitter and receiver, CCii is unity. For wall or ground reflectedis unity. For wall or ground reflected

and/or diffracted rays,and/or diffracted rays, CCii is proportional to the product of the reflection and/oris proportional to the product of the reflection and/or

diffraction coefficients at every point.diffraction coefficients at every point.


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Typical signal strength predicted in the line-of-sight or main street

MicrocellsMicrocells


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MicrocellsMicrocells

Typical predicted signal strength in the non-line-of-sight or side

street


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Typical coverage of microcellsTypical coverage of microcells


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PicocellsPicocells

Pico CellPico Cell

Pico cells are

introduced to provide

both coverage and

capacity for indoor

communications


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Slide 29

Into and Within building PropagationInto and Within building Propagation

Within

building

transmitter

Into buildingtransmitter


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IntoInto--Building PropagationBuilding Propagation

Propagation models that describe the signal characteristicsPropagation models that describe the signal characteristicsin open areas are not adequate for indoor propagation. Thisin open areas are not adequate for indoor propagation. This

is because indoor propagation is dependent on a number ofis because indoor propagation is dependent on a number of

additional factors not present in onadditional factors not present in on--street modelling:street modelling:

Building construction material Physical dimensions of the building and the number of floors

The nature of surrounding buildings

The various items of furniture and wall partitioning on each floor

of the building


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IntoInto--Building PropagationBuilding Propagation

Into building propagation is modelled through the use of twoInto building propagation is modelled through the use of twoparameters:parameters:

In-building penetration loss

Standard deviation of the log-normally distributed local mean

within the building


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IntoInto--Building Propagation (Contd.)Building Propagation (Contd.)

The building penetration loss is defined as the difference betweenThe building penetration loss is defined as the difference betweenaverage received signal strength measured over a small area within aaverage received signal strength measured over a small area within a

building and that measured outside at street level around the perimeterbuilding and that measured outside at street level around the perimeter

of the building. Several research activities have been reported in theof the building. Several research activities have been reported in the

literature. The main conclusion are:literature. The main conclusion are:

Penetration loss decreases at higher frequencies e.g. 18 dB at 450 MHz,14.5 dB at 900 MHz, 13.4 dB at 1800 MHz and 12.8 dB at 2300 MHz

The rate of change of penetration loss with height is approximately 2 dB per

floor with the penetration loss decreasing with height

Penetration loss also depends upon the logarithm of floor area

Penetration loss also depends upon the number of building sides seen by the

transmitter


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IntoInto--Building Propagation (Contd.)Building Propagation (Contd.)

The penetration loss is heavily dependent upon the constructionThe penetration loss is heavily dependent upon the constructionmaterial of the building and can therefore vary significantly frommaterial of the building and can therefore vary significantly from

building to building or from country to country depending uponbuilding to building or from country to country depending upon

building design.building design.

The penetration loss also depends upon the surroundingThe penetration loss also depends upon the surrounding

environment e.g. Penetration loss in urban areas (has been foundenvironment e.g. Penetration loss in urban areas (has been found

to be lower than obtained in subto be lower than obtained in sub--urban areas.urban areas.

The standard deviation represents the square root of the variance ofThe standard deviation represents the square root of the variance of

all recorded mean signal levels on a roomall recorded mean signal levels on a room--byby--room basis within theroom basis within the

building of interest.building of interest.


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Propagation Within BuildingsPropagation Within Buildings

The termThe termPropagation Within BuildingsPropagation Within Buildingsis often used to identify theis often used to identify thepropagation scenario when both transmitter and receiver are inside thepropagation scenario when both transmitter and receiver are inside the

same building. Experimental and theoretical studies have shown that:same building. Experimental and theoretical studies have shown that:

the overall signal coverage depends on the position of the transmitter inside

the building

for a one-cell signal coverage, the best transmitter location is in the middle ofthe building

the rate of change of mean signal per floor (at 1800 MHz) is approximately

8.3 dB/floor; 6.1 dB/floor for the floors below the transmitter and -10.4 for

floors above the transmitter

Rooms which are immediately above or underneath the transmitter generallyhave larger signal levels than rooms far away from the transmitter on the

same floor!


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Propagation Within BuildingsPropagation Within BuildingsSignal traverses

several walls andpartitions


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Freshfield InFreshfield In--building Measurementsbuilding Measurements

P1 P2 P3 P4 P5 P6

Office OfficeCentralaisle

P19 P18 P22

P7 P12 P13 P17

P21

P8 P24 P25 P15 P16

P23

P9 P10 P11 P14 P20

T e ean si nal lev el utsi e t e buil in was btaine b av era in easure si nallev els ar un t e eri eter f t e buil in .

T e ean si nal lev el f r eac fl r is calculate t us:

an t e enetrati n l ss f r eac fl r is calculate as:

!

!N

i

ifloormean PP

1

,

floormeanoutsidemean PPFPL ,, !


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In order to calculate the standard deviation for an entire building the individual signals

recorded in each room or segment are normalised b the floor mean and thencombined with the normalised data from all other floors.

The overall penetration loss in each building is obtained as the higher of two values:

the largest penetration loss recorded in the building or the intercept at floor 0 (ground floor) when the floor penetration loss figures are

plotted against floorlevel and regression anal sis is performed.

A equation of the form:

has been used in the regression anal sis for the estimation of the overall penetrationloss.

! !

!)(

1 1

)(

fl rsll

fl

rs

K

i

K

i

W

InterceptN mberloorSlopeP v!


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TABLE 6.1 INBUILDNG MEASUREMENTS AT THE HIGHER EDUCATION MINISTRYKey Features: The building is made of concrete and has marble walls. Two mezzanine floors which arecompletely open are just above the first floor. The building situated is 800m away from base station locatedat the Commercial Bank (MTC GSM Site No. 72).

O tdoor Mean Signal Le el = -90.1 dBm

Floor Mean Signal Level

(dBm)

FPL Floor Description

10 -104.10 14.00 High ooden partition ith glass indo s,

se eral offices

9 -98.47 8.37 same as 10

8 -103.26 13.16 same as 107 -105.44 15.35 same as 10

6 -107.93 17.83 same as 10

5 -105.92 15.82 Lo metal partitions, se eral offices

4 -108.57 18.48 same as 5

1 -111.63 21.53 same as 10

0 -110.83 20.73 same as 10

O erall Penetration Loss (dB) = MAX(REG,FPLi) = 21.89 dB

O erall standard de iation = 2.04 dB


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TABLE 6. INBUILDNG MEASUREMENTS AT SAFAT TOWER

Key Features: The building is characterised by marble walls. Offices with glass frontage are located on all floors.


Floor Mean Signal Level(dBm)

FPL (dB) Floor Description

2 -102.28 14.71 Offices ith glass frontage, se eral offices

1 -105.99 18.42 same as 2

0 -106.39 18.82 same as 2

0 erall Penetration Loss (dB) = MAX(REG,FPL i) = 19.38 dB



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Freshfield InFreshfield In--Building MeasurementsBuilding Measurements

TABLE 6.4 INBUILDNG MEASUREMENTS AT THE SECURITIES GROUP BUILDING

Key Features: Building made of concrete walls. Un-coated glass windows.

O tdoor Mean Signal Le el = -96 dBm

Floor Mean Signal Level

(dBm)


8 -102.73 6.73 High partitions, ith glass indo s

7 -106.20 10.20 same as 8

6 -106.54 10.55 same as 8

5 -107.63 11.64 same as 83 -108.52 12.53 same as 8

2 -107.80 11.80 same as 8

1 -101.40 5.41 Large open indo ith high partition

0 -101.82 5.82 Gro nd floor: same as 1

O erall Penetration Loss (dB) = MAX(REG,FPLi) = 14.40 dB

Note: Regression analysis excl ded floors 1 and 0 since they are not representati e.



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TABLE .5 INBUILDNGMEASUREMENTSATSOUKALKABIR

Key eatures:Buildingmadeofconcretewalls. thand 5th floorsarecar arks, th floorandaboveareoffices;Mezzanine and ground floors are shopping malls. Building located at approximately . km fr om base stationsituatedat theCommercial Bank (MTCGSMSiteNo. ).

utdoor ean ignal evel -87.25dB

loor Mean Signal Level

(dBm)

L loorDescription

10 -72.75 -14.50 This floor has a large open hall with s alloffices on theperiphery.

-80.17 -7.08 This floor has several narrow corridorsseparating woodenpartitionedoffices.

8 -81.52 -5.74 Wooden partitioned offices witha largedensityofoffice roo s.

1 -109.25 21.99 ezzanine floor with arble walls and floor

ade of arble tiles; large open area overlookingground floor.

0 -110.6 23.01 Ground floor: large open space in the iddle,shares co on ceiling with ezzanine floorwith shops oneither side.

verall enetration oss (dB) AX( G, i) 24.36dBverall standarddeviation 6.26dB


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TABLE 6.7 INBUILDNG MEASUREMENTS AT SOUK AL WATTANIYA

Key Features: Shopping mall. Shops with glass frontage; Walls on the outside are arched and made of thick

concrete. Altogether floors. Fifth floor (rooftop) is relatively open. 2nd, rd and 4th floors are car parks. Basestation located at Commercial bank (MTCs GSM Site No. 72).


Floor Mean Signal Level(dBm)


1 -107.65 30.93 First floor aisle area, alls made of concrete,se eral shops ith glass frontage.

0 -102.30 25.53 Gro nd floor

O erall Penetration Loss (dB) = MAX(REG,FPL i) = 30.93 dB



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TABLE 6.8 INBUILDN MEASUREMENTS AT KUWAIT ST CK EXCHAN E BUILDIN

Key Features: Building less than 5 away fro base station; howe er iew of trans itting antenna obstructedby its own building (Co ercial bank). Se eral glass windows. Measure ents around the peri eter of thebuilding yielded a ean signal le el lower than inside due to proxi ity of building to trans itter site. Mean

signal le el used for the outside is the le el easured on one side of the building (building ain entrance) whichis closest to trans itter.

Outdoor Mean Signal Level = -80.02 dBm (around the perimeter of the building)

= -66.20 dBm in front ofbuilding (value used in analysis)

Floor Mean Signal Le el(dB )


2 -85.73 19.53 Some offices, glass partitions, several glasswindows

1 -80.98 4.78 Some offices, area over looking ground floor,glass partitions

0 -77.59 11.39 Large open plan stock exchange area, floorbordered on all sides by glass windows

Overall Penetration Loss (dB) = MAX(REG,FPL i) = 19.53 dB

Overall standard deviation = 6.48 dB


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TABLE 6.9 INBUILDN MEASUREMENTS AT QURAIN

Key Features: Building located in the recently de eloped Qurain area. Surrounded by se eral buildings of si ilarconstruction. Walls are ade of bricks (2 layers) with internal insulation foa . Se eral glass windows whichper it signal entry. Building located approxi ately 2.6 k away fro base station situated in Qurain fire station(MTCs SM site No. 100).

Outdoor Mean Signal Level = -87.3 dBm

Floor Mean Signal Le el(dB )


2 -84.33 -2.96 Small area on the same level as rooftop openbalcony

1 -95.06 7.77 Bedrooms and living room areas; bathrooms

with marble walls; glass windows with no

curtains to absorb signal.

0 -98.27 10.98 Living room area and Kitchen. No curtains to

absorb signal; glass windows.

Overall Penetration Loss (dB) = MAX(REG,FPLi) = 12.23 dB

Overall standard deviation = 4.08 dB

Additional Information:

Basement Mean Signal Level = -117.36 dBm, Penetration Loss = 30.06 dB


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TABLE6.9 INBUILDNGMEASUREMENTSATADIWANI AH INFAIHA

KeyFeatures:Ground floor level building (Bungalow) madofbricks. Building locatedapproximately 3.1kmawayfrombasestationsituated inSKB (MTCsprevious GSMsiteNo. 2).

utdoor eanSignal Level = -93.56dB Floor Mean Signal Level

(dB )


0 -106.00 12.44 Large roo s, so e roo s with windows

verall PenetrationLoss (dB)=MAX(REG,FPLi)=12.44dB

verall standarddeviation=2.55dB


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TABLE6.10SUMMARYOF IN-BUILDINGMEASUREMENTS INBUSINESSDISTRICTAREAS

Building PenetrationLoss (dB) Standard Deviation(dB)

igherEducationMinistry 21.89 2.04

Kuwait Real EstateBank 15.05 2.94

Safat Tower 19.38 5.89

Securities GroupBuilding 14.40 3.57SoukAl Kabir 24.36 6.26MT Building 18.65 3.61

Souk Wattaniya 30.93 7.09Kuwait Stock Exchange 19.53 6.48

AVERAGE(includingSouks) 20.52 4.735AVERAGE(ExcludingSouks) 18.15 4.09

TABLE6.11SUMMARYOF IN-BUILDINGMEASUREMENTS INRESIDENTIALAREAS

Building PenetrationLoss (dB) StandardDeviation (dB)

QurainBuilding 12.23 4.08

iwaniyah, Faiha 12.44 2.55

AVERAGE 12.34 3.3

Basement areas: 30dB (Qurain), 41.7 dB (MTC)Basement areas: 30dB (Qurain), 41.7 dB (MTC)

Lift areas: 38.8 dB (MTC)Lift areas: 38.8 dB (MTC)


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SummarySummary

Minicells and microcells are predicted using anyone of threeMinicells and microcells are predicted using anyone of threetechniques.techniques.

InIn--building prediction depends upon several factors including buildingbuilding prediction depends upon several factors including building

material type, distance, floor area and number of walls.material type, distance, floor area and number of walls.

Building penetration losses in Kuwait are high at 20.56dB on average.Building penetration losses in Kuwait are high at 20.56dB on average.

Losses in basements are as high as 41 dB.Losses in basements are as high as 41 dB.Losses in lifts are as high as 30 dB.Losses in lifts are as high as 30 dB.

fresh field mtc 002 section 2

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