GSM Network Planning ABC - Coverage Planning V1.0

8/15/2019 GSM Network Planning ABC - Coverage Planning V1.0

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Coverage PlanningCoverage Planning


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Internal Use Only▲

Contents

1. Overview of coverage planning

2. Link budget

3. Propagation model

4. Scale estimation. Coverage en!ancing tec!nolog"

#. $!e common coverage issues %&'


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1. What is the purpose of coverage planning?2. What is the work content of coverage

planning?

3. What is the input of coverage planning?

4. What is the output of coverage planning?

1. Overview of coverage planning


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1. (!at is t!e target of coverage planning)

*o t!e*o t!e link budgetlink budget andand radius estimationradius estimation for t!e targetedfor t!e targeted

coverage area so as to get to know t!ecoverage area so as to get to know t!e site scalesite scale andand sitesite

deplo"mentdeplo"ment w!ic! satisf" t!e +P,. -esides if aw!ic! satisf" t!e +P,. -esides if a digital mapdigital map

is available an ad/ustment can be done to t!e sitesis available an ad/ustment can be done to t!e sites

according to t!e results ofaccording to t!e results of coverage simulationcoverage simulation..

*o t!e*o t!e link budgetlink budget andand radius estimationradius estimation for t!e targetedfor t!e targeted

coverage area so as to get to know t!ecoverage area so as to get to know t!e site scalesite scale andand sitesite

deplo"mentdeplo"ment w!ic! satisf" t!e +P,. -esides if aw!ic! satisf" t!e +P,. -esides if a digital mapdigital map

is available an ad/ustment can be done to t!e sitesis available an ad/ustment can be done to t!e sites

according to t!e results ofaccording to t!e results of coverage simulationcoverage simulation..

,t is a must to !ave a t!ree dimensional

digital map 0Planet$ w!ic! covers t!e

w!ole targeted coverage area. *egree of

accurac"

5or urban areas not lower t!an 26m7

5or rural areas not lower t!an 6m.


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2. (!at is t!e work content of coverage planning)

Clarif" t!e

input

Clarif" t!e

input

Site

deplo"ment

Site

deplo"ment

Link budget

Link budget

Propagation

modelcalibration

Propagation

modelcalibration

Coverage

simulation

Coverage

simulation

Scale

estimation

Scale

estimation

Coverag

e

planning

Coverage

planning


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3. (!at is t!e input of coverage planning)

• Which cities and major roads will be covered?

• What are the categories of scenarios according to the radioenvironment?

• What is the coverage range of each scenario?

• Which cities and major roads will be covered?

• What are the categories of scenarios according to the radioenvironment?

• What is the coverage range of each scenario?

The coverage requirements of each scenario

• !overage level

• !overage "robability

The coverage requirements of each scenario

• !overage level

• !overage "robability

• !arry out a test and calibrate the "arameters of the "ro"agation

model#

• $o test is carried out% and the "arameters of the standard

"ro"agation model are ado"ted#

• !arry out a test and calibrate the "arameters of the "ro"agation

model#

• $o test is carried out% and the "arameters of the standard

"ro"agation model are ado"ted#

• The equi"ment ty"es% which will be ado"ted for the bidding%

de"ends on the mar&et strategy#

• The biggest site configuration de"ends on the frequency bands and

the frequency resources#

• Is a 'lanet three(dimensional digital ma" available? The coverage

simulation can not do without the ma"#

• What about the a""lication of the different &inds of coverage

enhancing technologies? ))

• The equi"ment ty"es% which will be ado"ted for the bidding%

de"ends on the mar&et strategy#

• The biggest site configuration de"ends on the frequency bands and

the frequency resources#

• Is a 'lanet three(dimensional digital ma" available? The coverage

simulation can not do without the ma"#

• What about the a""lication of the different &inds of coverage

enhancing technologies? ))

he size and range of

the target coverage

area

he size and range of

the target coverage

area

KPI he coverage KPI

PI he coverage KPI

he parameters of the

propagation model

he parameters of the

propagation model

Others

thers


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4. (!at is t!e output of coverage planning)

Site scale

Site

deployment

Coverage

simulation

he !alanced

!udget of

uplink"downlinkpower


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1. Why is link !udget needed?

2. What is path link !alance?3. #ow can we $udge a link is limited?

4. What is the result if a link is limited?

%. What is link gain and link loss?

&. What is slow fading?

'. What is fast fading?

(. What is coverage pro!a!ility?

). What is margin?

1*. What kind of margin should !e considered for the link !udget?

11. What factors should !e taken into consideration to decide the slow

fading margin which is fre+uently used?

12. What is design signal level and acceptance level?

13. What are the categories of com!iner loss which are fre+uently come

across in link !udget?

14. What factors should !e taken into consideration to decide the power

of the set,top unit of - series e+uipment?1%. What factors should !e taken into consideration to decide the

antenna and feeder loss of - series e+uipment?

1&. What is /0?

1'. #ow to choose the a suita!le type of antenna?

1(. #ow is the uplink"downlink !udget calculated?

1). #ow to avoid the un!alanced link in network planning?

2. Link budget


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2. (!at is link balance)

Strictly speaking link !alance means that the difference ofStrictly speaking link !alance means that the difference of

the path loss of the uplink radio link and that of thethe path loss of the uplink radio link and that of thedownlink radio link is *.downlink radio link is *.

enerally speaking it is considered that there is a roughenerally speaking it is considered that there is a rough

link !alance if the allowed ma5imum path loss differencelink !alance if the allowed ma5imum path loss difference

!etween the uplink and the downlink is no more than!etween the uplink and the downlink is no more than 2d62d6

when the link !udget is calculated.when the link !udget is calculated.

Strictly speaking link !alance means that the difference ofStrictly speaking link !alance means that the difference of

the path loss of the uplink radio link and that of thethe path loss of the uplink radio link and that of thedownlink radio link is *.downlink radio link is *.

enerally speaking it is considered that there is a roughenerally speaking it is considered that there is a rough

link !alance if the allowed ma5imum path loss differencelink !alance if the allowed ma5imum path loss difference

!etween the uplink and the downlink is no more than!etween the uplink and the downlink is no more than 2d62d6

when the link !udget is calculated.when the link !udget is calculated.

7ownlink

coverage

8plink coverage

8plink coverage

9

7ownlink

coverage


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3. 9ow can we /udge a link is limited)

8plink limited

:plink coverage ; *ownlink coverage ， t!at is

$!e allowed ma8imum uplink pat! loss ; $!e

allowed ma8imum downlink pat! loss

7ownlink limited

*ownlink coverage ; :plink coverage ， t!at is

$!e allowed ma8imum downlink pat! loss ; $!e

allowed ma8imum uplink pat! loss

8plink coverage

7ownlink coverage

he part of invalid

downlink coverage

7ownlink coverage

8plink coverage

$!e part of invalid

uplink coverage


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4. (!at is t!e result if a link is limited)

8plink limited

:n areas with pro!lems the handset has

signals !ut it can not originate a call;

When the su!scri!er moves towards the

!orders of a cell


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5. (!at is link gain and link loss)

ain means that a positive influence is e5erted over the link

and the signals are strengthened.

8nit d6

here are different categories of link gain> 0ntenna gain

diversity gain <

=ain=ain

oss means that a negative influence is e5erted over the link

and the signals are weakened.8nit d6

here are different categories of link loss> @eeder loss

com!iner loss

the loss caused !y the penetration of !uildings or cars

and !ody loss

LossLoss

4*d6m 7evice %*d6m

=ain>6?46>16d-

4*d6m 7evice 32d6m

Loss>46?32>@d-


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6. (!at is slow fading)

(!en t!e signals are transmitted t!e" will be blocked b" t!e buildings and t!e uneven land

forms. ,n t!e areas w!ere t!e signals are blocked t!e s!adow of electromagnetic waves will be

formed. 's a result t!e signal strengt! will be weakened. $!is is called S!adow 5ading a kind

of fading of signals w!ic! is caused b" t!e s!adow effect.

$!e signals go t!roug! a slow and random c!ange wit!in t!e range of doAens of wavelengt!s

so t!e statistical counting obe"s t!e rules of lognormal distribution. $!erefore S!adow 5ading

is also called Slow 5ading.

,n nglis! it is called Slow 5ading ，

or Log?normal 5ading ， or S!adow

5ading.


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B. (!at is fast fading)

(!en t!e signals are transmitted t!e" will be reflected and scattered man" times due to t!e surrounding environment 0for

e8ample buildings trees and so on. ,n t!is wa" t!e multi?pat! interference is formed so t!e amplitude and p!ase of a signal ma"

!ave a dramatic c!ange wit! t!e pass of time. $!e overla"ing of t!e multi?pat! signals forms a vector and a possible serious valle"

point of fading w!ic! result in a dramatic fluctuation of t!e intensit" of t!e field and a s!ort?term fading. $!e fast fading is a kind of

deep fading of signals w!ic! is caused b" t!e multi?pat! effect of signal transmission.

$!e statistical counting principles of probabilit" densit" of fast fading obe"s a a"leig! distribution. $!erefore 5ast 5ading is also

called a"leig! 5ading.

,n nglis! it is called 5ast 5ading or a"leig!

5ading.


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@. (!at is coverage probabilit")

Coverage probabilit" refers to !ow large t!e probabilit" is t!at t!e received signal of t!e terminal is larger t!ant!e t!res!old at t!e coverage borders of t!e cell 0or wit!in t!e coverage areas.

Coverage

pro!a!ility

he edge coverage pro!a!ility ： he percentage of the cell !orders whosereceived signal is larger than the threshold.

he area coverage pro!a!ility ： he percentage of the areas whose receivedsignal is larger than the threshold.

he threshold level of the cell !orders ： ,)*d6m

he threshold level of the cell !orders ： ,)*d6m

The test is carried out along the covered cell

borders. The edge coverage probability refers to the

percentage of samples, of which the level is at least

- 90dBm.

The test is carried out along the paths of the covered areas of

a cell. The area coverage probability refers to the percentage

of samples, of which the level is at least - 90dBm.

Under the sameconditions, the areacoverage probabilityis larger than theedge coverageprobability. The twocan be mutually

transformedaccording to somerules in math.


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D. (!at is margin)

(!en t!e radio signals are transmitted t!e" will !ave an

attenuation caused b" different kinds factors of t!e radio

environment for e8ample s!adow effect multi?pat! effect

and so on. $!erefore t!e influence caused b" t!ese factors

s!ould be taken into consideration w!en t!e design of radionetwork starts. 't t!e stage of network planning some power

can be reserved to resist t!e possible attenuation. $!e

reserved power is called margin.


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16. (!at kind of margin s!ould be considered for t!e

link budget)??1

*+, is a &ind of interference limited system# The received "ower should not only resist the

noises but also resist the co(channel-adjacent channel interferences which are caused by the

frequency reuse so as to ensure the quality of the signals# The "ower reserved to resist the

interference is called interference margin#

Usually it is .d/#

1

In order to ensure that the site can cover the cell borders with a certain "robability% the site must

reserve some transmission "ower so as to overcome +hadow 0ading# +o the reserved margin

is called +hadow 0ading margin or +low 0ading margin#

3

The multi("ath effect of the transmission of radio signals will result in the fast fading of signals%

so the quality of signals will be affected# 0or *+, system% it resists 0ast 0ading by ma&ing use

of a series of technologies% including interleaving coding% frequency ho""ing% diversity

rece"tion% ada"tive equali1ation% and so on# /esides% at the stage of networ& "lanning% some

design margin should be reserved to resist 0ast 0ading# This is called 0ast 0ading margin#

Usually% it is .d/#

2

Slow @ading marginSlow @ading margin

@ast @ading margin@ast @ading margin

Aamming marginAamming margin


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16. (!at kind of margin s!ould be considered for t!e

link budget)??2

2oss caused by the "enetration of a car refers to the attenuation

which occurs when the radio waves "enetrate the car# It is equal

to the difference value when the median value of the field

strength of the signals outside the car and that inside the car are

com"ared#

Usually% it is 3～4d/#

4/ody loss refers to the &ind of loss which is caused by signal

bloc&ing and absor"tion when the handset is held quite close to

the human body# Usually% for voice service% it is .d/5and for data

service% it is 6d/#

#

2oss caused by the "enetration of a building refers to the

attenuation which occurs when the radio waves "enetrate the

e7terior structures of a building# It is equal to the difference value

when the median value of the field strength outside the building

and that inside the building are com"ared# The value related of

this &ind of loss is closely related to the materials and thic&ness

of the building#

6ody loss6ody loss

oss caused !y the

penetration of a !uilding

oss caused !y the

penetration of a !uilding

oss caused !y the

penetration of a car

oss caused !y the

penetration of a car

!lassification ofdifferent areas

Ty"ical"enetration lossvalue

8ense urban 94 ～ ::

,edium urban 9; ～ :6

+uburban areasand rural areas

96 ～ 9;


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11. (!at factors s!ould be taken into consideration to

decide t!e slow fading margin w!ic! is freEuentl"

used)'rea $"pe

'reaCoverage

Probabilit"

dgeCoverage

Probabilit"

Slow5ading

Fargin 0d-

*ense :rbanSigma>16d-

BG 4G 1

@G #DG

D6G @6G B.B

DG @@G 11.B

Fedium :rbanSigma>@d-

BG 6G 6

@G ##G 3.2

D6G BG .

DG @#G @.B

Suburbanural oad Sigma>#d-

@6G 6G 6

@G #6G 1.#

D6G B1G 3.4

DG @4G .D


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12. (!at is design signal level and acceptance level)

$!e lowest level reEuired SSminHreE

,t refers to t!e lowest level reEuired for making calls in real situations 0outdoorindoorin a car.

On basis of t!e receiver sensitivit" it takes t!e following factors into consideration 5ast 5ading

margin interference margin bod" loss loss caused b" t!e penetration of a building w!ic! is

relevant to a indoor subscriber or loss caused b" t!e penetration of a car w!ic! is relevant to a

subscriber inside a car.

*esign level SSdesign

,n order to ensure a certain probabilit" it is necessar" to consider t!e S!adow 5ading margin on

basis of t!e lowest level reEuired or t!e acceptance level. $!en t!e level value is called design level.

,n ot!er words at t!e network planning stage it is a must to consider t!e possible influence e8erted

b" S!adow 5ading over t!e signal coverage. $!e purpose is to ensure t!e network coverage

probabilit".

'cceptance level SSacceptance

:suall" in t!e bidding documents or t!e contract t!e client will mention t!e *$ coverage +P,

including t!e reEuirements for level value and coverage probabilit" w!ic! *$ s!ould meet.

$!en t!e reEuired level value w!ic! *$ s!ould reac! is called t!e acceptance level b" us.

9owever if t!e client does not !ave an" reEuirements for t!e acceptance level we s!ould

make a suggestion. :suall" it is considered t!at SSacceptance s!ould be eEual to SSminHreE

0SSacceptance > SSminHreE.

1

2

3


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B2 series com!iner loss

13. (!at are t!e categories of combiner loss w!ic! are

freEuentl" come across in link budget)

1

Combiner D66F0d-1@66F0d-

C*: 4.4 4.#

C: 3. 3.

CI .3 .

FC*: 4.4 4.#

C*: 1 1

C: 3. 3.

B3 series com!iner loss

Combiner D66F0d-

1@66F0d-

C*: 4.4 4.#

C: 3. 3.

C*: 1 1

2

S7 series com!iner loss3

5or :62 and :62' t!e COF

loss is 3d- w!en it is S3JS4.

Ot!er radio freEuenc" processing

units do not !ave a combiner

inside.


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1. (!at factors s!ould be taken into consideration to decide t!e

antenna and feeder loss of K$ series eEuipment) $!e $"pical

'ntenna and 5eeder Connection

(it!out

$F'(it!

$F'

5eeder$"pe D66 1@66 :nit

9-:< 99#: 93#3 d/-966m

=-4< .#44 ;#=; d/-966m

;->< :#== >#93 d/-966m

9.-4< :#: .#>= d/-966m

The table here shows the typical KP of !ansen. t is "ust for

your reference. #or a specific pro"ect, the table should be filled

in according to the actual configuration of feeder line KP.

:f the feeder loss is more than

3d6 it is suggested that a

heavier feeder line should !e

used.

$"pe Loss :nit

!onnector 6#6; d/-each

T connector 6#. d/-each

2ightningarrester 6#: d/-each

T,@ insertionloss 6#; d/

$:ncrease the downlink insertion loss of

the tower amplifier


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. (!at factors s!ould be taken into consideration to decide t!e antenna

and feeder loss of K$ series eEuipment) $"pical 'ntenna and

5eeder Connection

:nstallation nearan antenna

1

%%& and BB& is connected

by fiber ；

%%& and antenna is

connected by '()* "umper.

'. )m +* loss for softer "umper

). ) connector loss

Heightof

antennaAmB

Ceight ofDDU on

"latform AmB

Lengthof 7!main

feederlineAmB

2engthof E

"#mperAmB

$onnectorF

lightningarrester

66,A

d/B

9466

,Ad/B

;6 6 ;6 > 3F9 :#4 >#6>

;6 96 >6 > 3F9 :#; .#>3

;6 :6 .6 > 3F9 :#99 :#4

;6 .6 :6 > 3F9 9#=. :#.9

;6 ;6 6 : : 6#.: 6#>.

'. ))m +* softer "umper loss

). ain feeder line loss between %%&

and the antenna

. / connectors loss. ' feeder line lightning arrester loss

he ta!le here is only for reference in practice please

calculate according to specific conditionsD

%%& is installed on the

platform of a tower 1a platform under the

antenna2， or installed at the

roof and it is lower than the

antenna ；

%%& and BB& is connected

by fiber ；

%%& and the antenna is

connected in a normal way.

The length of main feeder

line is the distance between

%%& and the antenna.

he installation

position keeps a

distance from

!oth 668 and

the antenna.

2


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1#. (!at is $F')

$F'M$ower Founted 'mplifier

$ower 'mplifier is t!e s!ort form for $ower Founted 'mplifier. 'ctuall" an amplifier w!ic! !as

low noises and !ig! linearit" 0low noise amplifier is installed at t!e front end of t!e receiving

s"stem of t!e site a place w!ic! is close to t!e receiving antenna. ,t is used to amplif" t!e uplink

signals to improve t!e noise figure of t!e receiving s"stem of t!e site and to improve t!e uplink

coverage capabilit".

EE ：： 8sually the FG: designed for the uplink gain is 12d6. 7oes it8sually the FG: designed for the uplink gain is 12d6. 7oes it

follow that 12d6 uplink gain should !e taken into consideration whenfollow that 12d6 uplink gain should !e taken into consideration when

the link !udget is calculated?the link !udget is calculated?

00 ：： HoHo. Since /0 is actually a low noise amplifier. In the one hand. Since /0 is actually a low noise amplifier. In the one handthe valid uplink signals are amplified on the other hand different kindsthe valid uplink signals are amplified on the other hand different kinds

of noises and interferences are also amplified. he actual uplink gainof noises and interferences are also amplified. he actual uplink gain

generated !y /0 is usuallygenerated !y /0 is usually 22 ～～ 3d-3d-..

EE ：： 8sually the FG: designed for the uplink gain is 12d6. 7oes it8sually the FG: designed for the uplink gain is 12d6. 7oes it

follow that 12d6 uplink gain should !e taken into consideration whenfollow that 12d6 uplink gain should !e taken into consideration when

the link !udget is calculated?the link !udget is calculated?

00 ：： HoHo. Since /0 is actually a low noise amplifier. In the one hand. Since /0 is actually a low noise amplifier. In the one handthe valid uplink signals are amplified on the other hand different kindsthe valid uplink signals are amplified on the other hand different kinds

of noises and interferences are also amplified. he actual uplink gainof noises and interferences are also amplified. he actual uplink gain

generated !y /0 is usuallygenerated !y /0 is usually 22 ～～ 3d-3d-..


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1B. 9ow to c!oose t!e a suitable t"pe of

antenna)'rea 'ntenna

!eig!t % m&

'ntennagain % d-i &

9oriAontalbeamwidt!of t!eantenna

Nerticalbeamwidt!of t!eantenna

PolariAationcategories

lectrical downtilt

*ense urban 26 ～ 2 1.J1B # @ ～ 14 *ual?polariAation

6 ～ 16 degreeelectrical downtilt

:rban areas 3 ～ 36 1.J1B # @ ～ 14 *ual?polariAation

2 ～ # degree electricaldowntilt

Suburban areas 3 ～ 46 1BJ1@ # ' D6 B ～ 16 *ual?polariAation

2 ～ 4 degree electricaldowntilt or wit!outelectrical downtilt

ural areas 4 ～ 6 1BJ1@ # ' D6 B ～ 16 *ual?polariAation verticalpolariAation

$!e electrical downtiltis optional.

9ig!wa"s or longand narrowvalle"s

4 ～ #6 1@J22 3 # ～ @ *ual?polariAation verticalpolariAation

$!e electrical downtiltis optional.

,f a single freEuenc" antenna is used b" a co?sited dual?band base station t!e antenna selected for t!e 1@66F base station

s!ould be 1 ～ 2d- !ig!er in antenna gain t!an t!at selected for t!e D66F base station. :suall" t!e antenna of a 1@66F base

station is !ig!er t!an t!at of a D66F base station b" 3 ～ m.

,f a dual?band antenna is selected t!e installation space can be saved. 9owever t!e separate ad/ustment made for t!e two

networks will not be so fle8ible. ,t s!ould be c!ecked w!et!er t!e antenna parameters of t!e two freEuenc" bands can bot!

meet t!e relevant reEuirements.

,n dense urban areas an antenna wit! a lower antenna gain can be c!osen if necessar".


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1@. 9ow is t!e uplinkdownlink budget calculated)

'arameter +ymbol Unit

Transmission "ower of thecarrier frequency

@ d/m

!ombiner loss / d/

Output power of t!e set?top unit of -$S

C>'?- d-m

0eeder line connector loss 8 d/

@ntenna gain of /T+ G d/i

@ntenna gain of ,+ 0 d/i

Deceiver sensitivity of ,+ * d/m

0ast fading margin C d/

Interference margin I d/

/ody loss H d/

2oss caused by the"enetration of a building ora car

d/

+low fading margin 2 d/

$!e minimum levelreEuired 0*L

F>=9,+ d-m

*esign level 0*L I>FL d-m

8ownlin& enhancingtechnology

O d/

$!e ma8imumdownlink pat! lossallowed

P>C?*5?IO d-

'arameter +ymbol Unit

Transmission "ower of ,+ @ d/m

@ntenna gain of ,+ / d/i

@ntenna gain of /T+ ! d/i

8iversity gain 8 d/

0eeder line connector loss G d/

The contribution tosensitivity made by T,@

0 d/

Deceiver sensitivity of /T+ * d/m

0ast fading margin C d/

Interference margin I d/

/ody loss H d/

2oss caused by the"enetration of a building ora car

d/

+low fading margin 2 d/

$!e minimum level

reEuired 0:LF>=9,+ d-

*esign level 0:L I>FL d-

U"lin& enhancingtechnology

O d/

$!e ma8imum uplinkpat! loss allowed

P>'-C*?5?I d-

C!oose t!e ma8imum pat! loss allowed for t!e link w!ic! is limited t!at is Fin 0P uplink P downlinkas t!e ma8imum pat! loss allowed for t!e w!ole linkQ

*ownlink :plink


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1D. 9ow to avoid t!e unbalanced link in network

planning)

he ma5imum uplink path loss allowed J he ma5imum downlink path

loss allowed difference value K 2d6

8plink limited :ncrease the uplink

coverage or decrease the invalid downlink coverage ink !alance

Solution> 0dd /0 adopt 4 antennae to do the diversity reception lower

the transmission power of the carrier fre+uency and so on.

he ma5imum uplink path loss allowed J he ma5imum downlink path

loss allowed difference value K 2d6 8plink limited :ncrease the uplink

coverage or decrease the invalid downlink coverage ink !alance

Solution> 0dd /0 adopt 4 antennae to do the diversity reception lower

the transmission power of the carrier fre+uency and so on.

$!e ma8imum downlink pat! loss allowed ; $!e ma8imum uplink

pat! loss allowed difference value R 2d- *ownlink limited

,ncrease t!e downlink coverage Link balance

Solution> :ncrease the transmission power of the set,top unit of 6Sincrease the num!er of antenna and feeder 7GC technology 77

technology and so on.

$!e ma8imum downlink pat! loss allowed ; $!e ma8imum uplink

pat! loss allowed difference value R 2d- *ownlink limited

,ncrease t!e downlink coverage Link balance

Solution> :ncrease the transmission power of the set,top unit of 6Sincrease the num!er of antenna and feeder 7GC technology 77

technology and so on.


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1. What is propagation model?

2. What are the categories of propagation model?

3. What are the fre+uently,used propagation

models?

4. Why is propagation model cali!ration necessary?

%. #ow to evaluate whether a propagation model is

suita!le or not?

&. #ow to get a propagation model !efore the

cali!ration is done?

3. Propagation model


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1. (!at is propagation model)

0 propagation model is a kind of0 propagation model is a kind of mathematical modelmathematical model whichwhich

descri!es and reflectsdescri!es and reflects the features of the transmissionthe features of the transmission

environment of the radio signals and the rules for theenvironment of the radio signals and the rules for the

changes of the signalschanges of the signals. 0ctually a propagation model. 0ctually a propagation model

representsrepresents a typical modela typical model of the transmission environmentof the transmission environment

which haswhich has some specific featuressome specific features..

0t the planning stage the propagation model can !e used in0t the planning stage the propagation model can !e used in

the following two ways.the following two ways.

0 propagation model is a kind of0 propagation model is a kind of mathematical modelmathematical model whichwhich

descri!es and reflectsdescri!es and reflects the features of the transmissionthe features of the transmission

environment of the radio signals and the rules for theenvironment of the radio signals and the rules for the

changes of the signalschanges of the signals. 0ctually a propagation model. 0ctually a propagation model

representsrepresents a typical modela typical model of the transmission environmentof the transmission environment

which haswhich has some specific featuressome specific features..0t the planning stage the propagation model can !e used in0t the planning stage the propagation model can !e used in

the following two ways.the following two ways.

stimation of t!ecell radius

Simulation


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2. (!at are t!e categories of propagation

model) Fodel Statistical model *eterministic model

Concept $!e propagation modelis based on t!estatistical anal"sis of alarge Euantit" of testingdata.

$!e propagation model isobtained t!roug! t!esimulation of t!e multi?pat!transmission traces of t!eradio waves. $!e simulationis based on t!e geometricalinformation of t!e clutterand t!e buildings w!ic!appear on t!e transmission

pat!.

'mount of calculation Small Large

Computational accurac" 'verage 8cellent

eEuirements for t!e accurac" oft!e digital map

26mJ6m 1mJm

$!e reEuirements for t!e clutter

of t!e digital map

$!e information of t!e

buildings is notincluded.

$!e information of t!e

buildings must be included.

'pplication range R1km ;1km

5reEuentl"?used models O+:F:'?9'$'COS$231:niversal model

NOLC'IO


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$!e freEuentl"?used

propagation models

Okumura?9ata

:niversal model

Nolcano COS$231

3. (!at are t!e freEuentl"?used propagation models)

•6.=J1.=9A（ 5or D66F）•Facro cell model•,t is suitable for D66F sites w!eret!e simulation and scale estimationwill be done for a large Euantit" ofsites in a wide range.

•1.=J2=9A 05or1@66F•Facro cell model•,t is suitable for1@66F sites w!eret!e simulation andscale estimation willbe done for a largeEuantit" of sites in awide range.

•6.=J2=9A 05or D66 1@66F•Facro cell model•,t is suitable for t!e sites w!ere t!esimulation and scale estimation will bedone for a large Euantit" of sites in a widerange.•'t present t!is model is adopted b"',COFCIP.

•6.=J2=9A•Ficro cell model•,t is suitable for aspecific area w!ere t!esimulation will be donefor a small Euantit" ofsites.


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4. (!" is propagation model calibration necessar")

$!e radio transmission environment differs for eac! place due to t!e various land forms geograp!ic

features distribution of buildings coverage of vegetation and so on. 5or e8ample cities in plain

areas NS cities in areas wit! !ills cities w!ere t!ere is a dense distribution of !ig! buildings NS

cities w!ere most of t!e buildings !ave 1 ～ 2 store"s cites in desert areas NS cities in areas w!ere

t!ere is a wide coverage of vegetation < < 'ctuall" propagation model calibration is necessar" for

eac! cit". $!e purpose is to get t!e parameters of t!e propagation model w!ic! is consistent wit!

t!e actual situation.,f t!e same set of parameters is applied to ever" scenario it is Euite possible t!at t!e planning

sc!eme differs greatl" from t!e actual situation. 9ere are t!e conseEuences

1. $!e network coverage w!ic! !as been establis!ed is not good enoug! to meet t!e coverage +P,.

2. ,t is a large waste of resources if t!ere are too man" sites. -esides severe interferences ma"

appear if t!ere is a dense distribution of sites.


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. 9ow to evaluate w!et!er a propagation model is

suitable or not)

-efore t!e calibration$!e Fean rror is not 6 t!e standard deviation Std *ev islarge.5igure $!e intersection point of t!e red line and t!e verticala8is is not 6.67 t!e slope of t!e red line is not 6.

9oriAontal ordinate $!e logarit!m of t!e distance betweent!e testing place and t!e base station is represented b"logd.Nertical ordinate $!e Fean rror w!ic! is calculated b"comparing t!e actual level of t!e testing place and t!epredicted level of t!at place is represented b" rror.*ense dots $esting places$!e red line ,t s!ows a kind of tendenc" about w!at t!eFean rror is likel" to be w!en t!e overall actual testingvalues of t!e testing place are compared wit! t!epredicted values.

'fter t!e calibration$!e Fean rror tends to be 6 t!e standard deviation Std*ev;>@d-. $!is means t!e model is Euite consistent wit!t!e actual situation.05or dense urban areas std dev;>16d- is alsoacceptable. 75igure $!e intersection point of t!e red line and t!e verticala8is is 6.67 t!e slope of t!e red line is 6.


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#. 9ow to get a propagation model before t!e calibration

is done)

Conditions

'. The digital map of the city for

which the planning will be done.

). n the propagation model library,

there are a certain amount of

parameter sets related to the

propagation models, which are

reliable and accurate.

. 3 tool used for choosing a model

automatically

:f it is not possi!le to carry out the propagation model test or cali!ration of the

target city due to the pro!lems of resources or time and the like it is accepta!le

to choose a propagation model from the model li!rary !y following some certain

rules. his model can !e regarded as an alternative choice which should !e

similar to the actual radio environment of the target city. #owever there may !e

some differences !etween the alternative choice and the actual situation.

0s to the rules for choosing the model they can !e set up according to the

e5perience of the engineers or !y using some customiLed automatic tool.0ctually this kind of tool will !e applied to the oad /ap of CHG.

isks

t should be noticed that the model,

which is selected by using the tool, can

only be regarded as the most suitablemodel from the e4isting model library.

!owever, it does not mean that it is

completely matched with the actual

environment.

I t l U O l ▲


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1. #ow to estimate the coverage radius of a single

site?

2. WhatMs the influence of downtilt over the

coverage?

3. #ow to calculate the site distance at the pre,

planning stage?

4. #ow to estimate the coverage area of a single site?

%. #ow to estimate the scale of coverage?

4. stimation of t!e coverage scale

I t l U O l ▲


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1. 9ow to estimate t!e coverage radius of a single site)

!hoose a universal "ro"agation modelPL>k1k2lgdk39mk4lg9mklg9bk#lg9bLgdkBdiffraction clutter LossCere%'2 means the ma7imum "ath loss allowed for the whole lin&% which is calculated in the lin& budget#&9～ &= and !lutter 2oss are the "arameters which are obtained after the "ro"agation modelcalibration# A@s to the estimation of the radius% only &9 ～ &3 will be involved in the calculation#B

Cm is the height of ,+#Cb is the effective height of /T+ antenna#d refers to the distance between the base station and ,+ A&mB#When d of the model above is calculated in a reverse way% the following formula can be obtained#d>16T00PL?+1?+39m?k4lg9m?klg9b0k2k#lg9b9ere d is actuall" t!e estimated coverage radius of t!e base station.

Link budget =et t!e ma8imum pat! loss allowed for a w!ole link t!at is PL.1

Propagation model calibration =et t!e value of eac! parameter of t!e propagation model2

Calculate UdV of t!e propagation model formula in a reverse wa" =et t!e ma8imumcoverageradius of t!e site

3

I t l U O l ▲


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2. (!atWs t!e influence of downtilt over t!e coverage)

(!en t!e ma8imum pat! loss allowed is calculated in t!e link budget t!e influence e8erted b" t!edowntilt is not taken into consideration. ,f t!e influence e8erted b" t!e downtilt over t!e coverage is

to be taken into consideration t!e radius s!ould be estimated according to t!e following formula.

*$ *owntilt 0mec!anical downtilt electrical downtilt9 $!e antenna !eig!t of -$S'tan ,nverse tangent trigonometric

functionN- Nertical 3d- beamwidt! of t!eantenna*5 $!e distance to t!e fart!est placew!ic! t!e upward 3d- beamwidt! cancover. ,t is t!e predicted coverage radiusw!en t!e downtilt *$ is taken intoconsideration.*I $!e distance to t!e nearest placew!ic! t!e downward 3d- beamwidt! cancover * $!e distance covered b" t!e main loberig!t a!ead

I t l U O l ▲


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3. 9ow to calculate t!e site distance at t!e pre?planning

stage)

$!ree?sector

directional sites Omni sites

The distance between two three(

sector directional sites is 9#;D#D re"resents the radius of the

directional cell#

The distance between two omni

sites is 9#=.D#D re"resents the radius of the

omni cell#

If two(sector directional sites are used for the

coverage of a long and narrow road% the

distance between the sites should be :D#

D re"resents the radius of the directional cell#



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4. 9ow to estimate t!e coverage area of a single site)

' t!ree?sectordirectional site

'n omni site

Cell radius

$!e coveragearea of a single

cell

6.#2 2.#2

$!e coveragearea of a singlesite

1.D2 2.#2



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. 9ow to estimate t!e scale of coverage)

F:

S:

5or e8ample

'ccording to t!e radio environment t!e target cit" 'is divided into two parts t!at is t!e mean urbanarea F: and t!e suburban area S:. $!e two areas

are represented b" two pol"gons separatel".

F: S: Iotes

Cell radius km 6. 1 $!e estimated

radius $!e siAe of t!ecoverage area of asingle cell km2

6.1#2 6.# 6.#2

$!e siAe of t!ecoverage area of asingle site km2

6.4@B 1.D 1.D2

$!e siAe of t!epol"gon km2

4 16$!e siAe of t!epol"gon S

$!e number of-$Ss 0Ium

@ Ium>S01.D2

$!e total number of-$Ss of t!e cit" '

13>Ium0F:Ium0S:



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1. #ow many coverage enhancing technologies are

there?

2. What is !ypass?

3. What is 7GC?

4. What is 77?

%. What is @W7?

&. What is :C?

. Coverage en!ancing tec!nologies



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1. 9ow man" coverage en!ancing tec!nologies are

t!ere)

:plink coverageen!ancing

*ownlinkcoverageen!ancing

Iotes

$F' -"pass

*PC$ and **$ cannot be used at t!esame time.

5(* *PC$

,C **$



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2. (!at is b"pass)

Combiner

*uple8er

LI'

C*:

$X1 $X2 $X

X1

X2

X3

X4

X1

X2

Combiner

*uple8er

LI'

C*:

'I$0X$X

$X1 $X2 $X

X1

X2

X3

X4

X1

X2

$X1 $X2

'I$0X$X

$X XF X* $X XF X*

,f a cell is configured wit! no more t!an 2 carrier freEuencies t!e $X interface of a carrier freEuenc" can

be connected to t!e $X interface of a C*: t!en it can be connected to a *uple8er directl" wit!out t!euse of a combiner.

(!en t!e link budget is calculated onl" 1d- duple8er loss is considered and t!e power of t!e set?top

unit is increased.



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3. (!at is *PC$)

*ual Power Combining $ransmission

*PC$ means t!at two transmitters send t!e same bursts at t!e same time w!ic! are

combined in t!e form of one carrier freEuenc" t!roug! a combiner so as to increase

t!e output power.

5rom a p!"sical perspective *PC$ can !elp to increase t!e power so it is especiall"

suitable for areas w!ic! need a wide coverage.

$!e two signals !ave t!e same p!ase

and amplitude and t!e" are combined

wit!in a carrier freEuenc" module.

$!eoreticall" speaking 3d- downlink

gain can be obtained if one P' is

combined wit! anot!er. 9owever if t!e

internal loss is taken into consideration

t!e actual gain of *PC$ is 2.d-.



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4. (!at is **$)

*ela" *iversit" $ransmission

**$ means t!at two carrier freEuencies send t!e same signals at a slig!tl" different time. $!e

signals are sent out b" different antennae so as to get some timespace diversit" gain. ,n t!is wa"

t!e downlink coverage is en!anced. **$ is suitable for some complicated radio transmission

environment.

't -SC side t!e mainau8iliar" $X can be regarded as one $X and t!e parameters w!ic! t!e

au8iliar" $X is configured wit! are t!e same as t!ose w!ic! t!e main $X is configured wit! . $!eEuantit" of signs inserted between t!em can be configured at OFC.

$!e downlink gain w!ic! can be generated b" **$ is 2J3d-.

D0 '@

D0 '@

'hase adiust

algorithm

'hase adiust

algorithm



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. (!at is 5(*)

5our (a" *iversit" eceiving

5(* means t!at 4 single antennae or 2 dual?polariAed antennae are used to make

a single carrier freEuenc" !ave four?wa" received signals. $!en t!ese signals are

combined as a one?wa" signal t!roug! t!e merging algorit!m so as to en!ance t!e

diversit" gain.

Compared to t!e two wa" diversit" gain 5(* can generate an e8tra 2 ～ 3d- gain

for t!e uplink receiver sensitivit". :nder t!e multi?pat! loss condition t!e dense

urban areas w!ic! !ave a complicated transmission environment can !ave a !ig!er

gain.



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#. (!at is ,C)

,C ,nterference e/ection Combining

,f t!e interferences of t!e diversit" reception signals from two different wa"s are relevant to eac!

ot!er t!e relevance computing will be done for t!e noises of eac! diversit" branc! to c!eck t!e

relevanc" between t!e interferences and to combine t!e signals accordingl". $!e purpose is to

complete t!e interference re/ection and to improve t!e Eualit" of t!e received uplink signals.

(it! ,C C, can get about 3 ～ d- gain in dense urban areas w!ere t!e radio environment is

complicated.

FC Fa8imum atio Combining

,f t!e interferences of t!e diversit" reception signals on two different wa"s are not

relevant to eac! ot!er weig!ting and combining s!ould be done to t!e signals from F

different wa"s.

,f t!e interferences received from different antennae are notrelevant to eac! ot!er t!e performance of ,C is similar tot!at of FC. 9owever if t!e interferences are relevant to eac!ot!er ,C is muc! more stronger t!an FC in terms of t!einterference re/ection abilit".



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1. What is a !lind Lone under a tower?

2. #ow to solve the pro!lem if there is a !lind Loneunder the tower?

3. What is weak coverage?

4. #ow to solve the pro!lem of weak coverage?

%. What is overshooting?

&. #ow to solve the overshooting pro!lem?

'. When is it called that there is not a serving cell?

(. What measures can !e taken to solve the pro!lem

that there is not a serving cell?

#. $!e freEuentl" asked Euestions about

coverage planning %&'



50/58


1. (!at is a blind Aone under a tower)

$ull It refers to the dee" fading "oint between thecentral lobe and the side lobe% or between two sidelobes#

?B6d-m

?D6d-m

?@6d-m

?D6d-m

' blind Aone under a tower refers to a part of t!e user Aone w!ic! needs to be covered

an area w!ic! is covered b" t!e first null or t!e second null under t!e vertical antennaradiation pattern. Compared to an" ot!er area w!ic! is eit!er near or far t!e signalstrengt! of t!e blind Aone under a tower ma" !ave greater attenuation 026 ～ 36d- and aweak coverage area is formed. 's a result t!ere ma" be a large number of subscribercomplaints and t!e +P,s of call drop rate and t!e like ma" be affected.$!e location of t!e blind Aone under a tower is related to t!e antenna radiation patternt!e antenna !eig!t and t!e transmission environment.

@ blind 1oneunder a tower



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y

2. 9ow to solve t!e problem if t!ere is a blind Aone under

t!e tower)

Iull fill $!e s!aped?beam s!ould be used to complete t!e first lower null fill of

t!e side lobe of t!e vertical pattern of t!e antenna so as to reduce t!e deepfading of t!e null.

C!oose a null fill antenna7C!oose an electrical downtilt antenna7'd/ust t!e antenna downtilt appropriatel" so as to avoid t!eblind Aone under a tower in a dense user Aone.

@n antenna with a null fill @n antenna without a null fill



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y

3. (!at is weak coverage)

(eak coverage means t!at t!e signal level is too low to keep agood call Eualit". ,t is usuall" believed t!at t!e coverage will beweak if t!e signal level is lower t!an ?D6d-m. ,f t!e coverage isweak t!ere will be man" problems for e8ample subscribercomplaints !ig! call drop rate and so on.

5or e8ample t!e power of t!e set?top unit of t!e base

station is too small7 t!e site planning is not reasonable7t!e antenna !eig!t is too low according to its original

design7 t!e inclination is too large7 t!ere is some

blocking because of t!e land forms or t!e buildings.

Concept

Causes

@ wea& coverage

area

@ wea& coverage

area



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y

4. 9ow to solve t!e problem of weak coverage)

't t!e network planning stage more attention will be given to

t!e possible weak coverage areas. $!e following factors

s!ould be taken into full consideration $!e site location t!e

antenna t"pe and t!e reasonableness of t!e designed

engineering parameters.

,ncrease t!e power of t!e set?top unit of t!e base station.C!eck t!e decreased power problems caused b" t!e

eEuipment failures.,n t!e weak coverage areas some base stations or repeaters

s!ould be added.



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y

. (!at is overs!ooting)

Overs!ooting means t!at t!e actual coverage range of a

cell e8ceeds t!e range w!ic! !as been designed

before!and and an overlapping area is formed b" t!is celland anot!er cell w!ic! is far from it.

Overs!ooting ma" result in freEuent !andovers an

increase of interferences t!e islanding effects and so on.

9ere are t!e possible causes $!e transmission power

of t!e base station is too large7 t!e antenna lobe is toolarge7 t!e antenna is too !ig!7 t!e inclination is too

small7 t!ere is an uneven land form7 and so on.

Concept

Causes

'

-

C

Cell ' is anovers!ooting

area.



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#. 9ow to solve t!e overs!ooting problem)

One s!ould be cautious w!en t!e site location is selected for a

!ig!land or a mountain slope.

,t s!ould be ensured t!at t!e antenna t"pe and t!e engineeringparameters of t!e antenna s!ould be reasonabl" selected or designed at

t!e network planning stage.$!e coverage area of t!e overs!ooting area s!ould be controlled

t!roug! t!e ad/ustment of engineering parameters and t!e transmission

power of t!e base station.,f it is not possible to control t!e coverage at t!at time it is suggested

t!at some neig!bor cells s!ould be added to t!e overs!ooting cell.

'

-

C

n!ance t!e neig!bor cellrelations between ' and C.

'

-

C

Control t!e coverage area of '.



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$!ere are freEuent cell reselections w!en t!e !andset is at an idle state.

,n t!e cells at t!e borders of L'C t!e location update occurs freEuentl" due to t!e

freEuent cell reselections. 's a result t!ere will be an unnecessar" increase of signalingload or congestion. -esides t!ere will be Uping?pong !andoversV during t!e calls and

t!e voice Eualit" will deteriorate.

$!e transmission rate of t!e data service will be affected.

-ecause of t!e fluctuations of signals t!ere will be more subscriber complaints.

$!ere are interferences C, is not satisfactor" and t!e voice Eualit" deteriorates.

B. (!en is it called t!at t!ere is not a serving cell)

5or 2 or more cells t!e signal strengt! of one cell is Euite close to t!at of anot!er cell it is not

found t!at t!e signal strengt! of an" cell !as a big advantage over ot!er cells. $!e !andset !as

freEuent cell reselections w!en it is at an idle state or t!ere are Uping?pong !andoversV during

t!e calls. $!e problems mentioned !ere are caused b" t!e fact t!at t!ere is not a serving cell.

$!e engineering parameters of

t!e antenna are not designed in a

reasonable wa".$!e transmission power of t!e

carrier freEuencies is too large or

too small.$!e configuration of t!e

parameters is not reasonable NN

5or t!e 3 cells in t!is area t!esignal level of eac! cell is

almost t!e same so t!ere isnot an obvious serving cell.

Concept

,nfluence

Causes



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@. (!at measures can be taken to solve t!e problem t!at

t!ere is not a serving cell) 'd/ust t!e antenna directional angle or t!e antenna

downtilt so as to ensure t!at t!ere is a serving cell of

t!e coverage area w!ic! !as relativel" strong and

stable signals.

'd/ust t!e transmission power of t!e carrier

freEuencies of t!e relevant cells so as to ensure t!at

t!ere is a serving cell of t!e coverage area w!ic! !asrelativel" strong and stable signals.

(!en t!e serving cell of t!e area is made clear it is

suggested t!at t!e cell reselection parameters s!ould

be ad/usted so as to ensure t!at t!e subscribers can

reside in t!e serving cell as long as possible. ,n t!is

wa" it is possible to relieve t!e freEuent cellreselections.

(!en t!e serving cell of t!e area is made clear it is

suggested t!at t!e !andover parameters of t!e cells s!ouldbe ad/usted so as to reduce or eliminate t!e Uping?pong

!andoversV during t!e calls.

1

2

3

4


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GSM Network Planning ABC - Coverage Planning V1.0

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Transcript of GSM Network Planning ABC - Coverage Planning V1.0