6 OMF005601 Coverage Planning ISSUE1.0

8/7/2019 6 OMF005601 Coverage Planning ISSUE1.0

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Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved.

Coverage Planning

Principle


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Page2Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved.

Contents

1. Planning Basis

2. Coverage Planning

3. Advance Planning

4. Advance Technology for improving coverage


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Radio PropagationEnvironment


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Reflections

direct signal

strong reflected signal

equalizer window 16 s

amplitude

delay time

long echoes, out of equalizer window:

self-interference


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Fading

Slow fading (Lognormal Fading)

Shadowing due to large obstacles on propagation

direction

Fast fading (Rayleigh fading)

Serious interference from multi-path signals


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Fading

time

power

2 sec 4 sec 6 sec

+20 dB

mean

value

- 20 dB

lognormal

fading

Rayleigh

fading


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Objective of Propagation Model

The propagation model is used to estimate the path loss during

radio wave propagation caused by the terrain and artificial

environments

The propagation model is the foundation of the coverage

planning. A good model mean more precise planning. The propagation model depends on the working frequency of the

system. Different propagation models have different working

frequencies ranges. Moreover, indoor propagation model differs

from the out door propagation model


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Land Usage Types

Urban small cells, 40..50 dB/Dec attenuation

Forest heavy absorption; 30..40 dB/Dec; differs

with season (foliage loss)

Open, farmland easy, smooth propagation conditions

Water propagates very easily ==> dangerous !

Mountain surface strong reflection, long echoes

Hilltops can be used as barriers between cells, do

not use as antenna or site location


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Contents

1. Planning Basis


3. Advance Planning



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Cell Coverage Range

Achievable cell coverage depend on

Frequency band (450, 900, 1800 MHz)

Surroundings and environment

Antenna type

Antenna direction

Minimum required signal level


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Min. Receiving Level

On Down Link

On Uplink

npenetratioinm

inminmmsreceive

LFastFading

ngSlowlyFadiISMin

++

++=

arg

argarg

npenetratioinminminmbtsreceive LFastFadingngSlowlyFadiISMin ++++= argargarg


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Fading

Slow fading (Lognormal Fading)

Shadowing due to large obstacles on propagation

direction

Fast fading (Rayleigh fading)

Serious interference from multi-path signals+10

0

-10

-20

-300 1 2 3 4 5 m

Level (dB)

920 MHz

v = 20 km/h


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Fading

time

power

2 sec 4 sec 6 sec

+20 dB

mean

value

- 20 dB

lognormal

fading

Rayleigh

fading


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Min. Receive LevelApplication

Environment

Min. Receiving

Level

Given

Density urban, indoor ? dBm Sms=-102dBmFast Fading Margin=3dB

Slowly Fading Margin=7dB

Interference margin=4dB

Penetration Loss=18

Resident area, indoor ? dBm Sms=-102dBmFast Fading Margin=3dB



Penetration Loss=10

Outdoor ? dBm Sms=-102dBmFast Fading Margin=3dB




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Min. Receive LevelApplication

Environment

Min. Receiving

Level

Given

Density urban, indoor -70dBm Sms=-102dBm

Fast Fading Margin=3dB



Penetration Loss=18

Resident area, indoor -80dBm Sms=-102dBm




Penetration Loss=10

Outdoor -90dBm Sms=-102dBm





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Link Budget

receivemsbtscablecombinerbts MinGLGLLP++

receivecablebtsdiversitymsms MinLGGLGP +++


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Link Budget Model

receivemsbtscablecombinerbts MinGLGLLP ++

receivecablebtsdiversitymsms MinLGGLGP +++

On downlink

On uplink


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Equipment-related Parameters BTS Tx power

Maximum BS Tx power.

Maximum power of the antenna Ptrx-Lcdu

Maximum MS Tx power

900:2W

1800:1W BS antenna gain

Typical value: Omni directional antenna: 11dBi or 13dBi;directional antenna: 15 to 18dBi.

MS antenna gain

Generally, MS antenna and the connection loss areconsidered to be 0dB.


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Equipment-related Parameters

BTS receiver sensitivity

-112.5dBm

The sensitivity is also related with vendor andenvironment

MS receiver sensitivity

-102dBm


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No Combining

TCOM

TRX0TRX0

TX

TRX1TRX1

TX

TX1

IN1

IN2

TX2

RXM1

RXD1

RXM2

RXD2

combinercombiner


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Wide Band Combining

TRX0TRX0

TX

TRX1TRX1

TX

TX1

IN1

TCOM

IN2

TX2

combinercombiner


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Feeder and Jumper

feeder

connector

Feeder

Antenna Adjustable Support

GSM/CDMAPanel Antenna

BTS

Wall

jumper


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Antenna Feeder SystemFeederFeeder:

Frequently-used

specification:

7/8 ", 5/4 "

900MHZ 1800MHZ5/4 >80 meters >50 meters

7/8 "


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Coverage Probability

area coverage probability: Within a coverage area, the percentage

of area in which receive signal strength (RxLev) is always higher than

RxLev threshold

edge coverage probability: In coverage board area, the percentage

time when the receive signal strength (RxLev) is always larger than

the of RxLev threshold


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Area coverage probability to edgecoverage probability

area coverageprobability

50% 60% 75% 80% 85% 90% 91% 93% 95% 97% 98% 100%

edgecoverage

probability

Denseurban

20% 30% 49% 57% 66% 75% 77% 81% 86% 91% 94% 100%

urban 20% 30% 49% 57% 66% 75% 77% 81% 86% 91% 94% 100%

Ruralarea

20% 30% 49% 57% 66% 75% 77% 81% 86% 91% 94% 100%

village 17% 27% 46% 54% 63% 73% 76% 80% 85% 90% 93% 100%

High way6% 14% 32% 50% 51% 64% 66% 72% 79% 86% 90% 100%


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Margin

To ensure a certain edge coverage probability , it is

necessary to reserve some power margin, i.e. the

shadow fading margin.

Due to the shadow fading, the actual path lossfluctuates around this value. It is subjected to the

logarithmic normal distribution as the location and

time varies.


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Area coverage probability toexpected shadow fading margin

Dense Urban


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Min. Receiving Level

On Down Link

On Uplink

marginfadingshadowarg

argarg

+++

++=

npenetratioinm

inminmmsreceive

LFastFading

ngSlowlyFadiISMin

marginfadingshadow

argargarg

++

+++=

npenetratio

inminminmbtsreceive

L

FastFadingngSlowlyFadiISMin


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ExampleMS sensitivity (dBm) -102

MS max. transmitting power(dBm) 30

BTS max. transmitting power (dBm) 46

BTS combiner loss (dB) 1

7/8 feeder length (m) 45 4dB/100m

1/2 jumper length (m) 5 11dB/100m

feeder connector loss (dB) 0.5

BTS combiner, jumper, feeder and connector

loss (dB)

?

BTS antenna gain (dBi) 17

Effective Radiated Power EIRP(dBm) ?


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Exampleexpected area coverage probability 97%

corresponding edge coverage probability 91%

expected shadow fading margin (dB) ?dB

Noise correction (dB) (interference margin) 2

Body loss (penetration loss) 4

Fast fading margin 1dB

clutter loss (dB) (slow fading margin) 2dB

MS antenna gain 1dB

allowed DL Max Propagation loss in Um interface(dB) ?


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Site Coverage Radius: R

Site distance: D=1.5R

Coverage Area=1.949R2

Site Coverage Radius: R

Site distance: D=1.732R

Coverage Area=2.598R2

3 Sectors site Omni site

Distance and CoverageArea


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Example

Expected coverage areadimension km2

500

Site type Omni

Cell radius km 0.80

Cell dimenstion km2 ?

Expected BTS number ?


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Contents

1. Planning Basis


3. Advance Planning



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Why Indoors

Indoor coverage become the main competition between operators

Subscribers expect continuous coverage and better quality

Outdoor cell cant provide sufficient indoor coverage

INDOOR SOLUTION

Good

Quality!


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Building Penetration Loss

rear side :

-18 ...-30 dB

Pref= 0 dB

Pindoor = -3 ...-15 dB

Pindoor = -7 ...-18 dB

-15 ...-25 dB no coverage

signal level increases with floor

number :~1.5 dB/floor (for

1st ..10th floor)


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Building Penetration Loss

Signal loss for penetration varies between

different building materials, e.g.:

mean value

reinforced concrete wall, windows 17 dB

concrete wall, no windows 30 dB

concrete wall within building 10 dB

brick wall 9 dB

armed glass 8 dB

wood or plaster wall 6 dB

window glass 2 dB


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Indoor Coverage Solutions

Small BTS

Mini BTS

Repeater

Active

Passive

Optical

Antennas

Distribute antenna

Leaky cable

Signal distribution Power splitter

Optical fiber


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Indoor Planning

Example2:

1.2 MHz allocation

50 mErl/subscriber , GOS=2%

reuse per two floor, separate

frequencies within one floor:

a) three floors

52.12 Erl => 842subs

b) ten floors

140 Erl => 2808 subs

Example1:

1.2 MHz allocation

50 mErl/subscriber, GOS=2%

no frequency reuse:

a) three floors

34.68 Erl=> 694 subscribers

b) ten floors

34.68 Erl => 694 subscribers

Single cell approach Multi-Cell approach

t

f5

f6

f5

f1

f2

f1

f3

f4

f3f1..f6

f1..f6

f1..f6


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Indoor Coverage Examples

With Repeater Relay outdoor signal into target building

Need donor cell, add coverage but not capacity

With indoor BTS and distributed antenna

Heavy loss bring by power splitting and cable

1:1

50m

50m

1:1

50m

50m

1:1

50m

50m

1:1

50m

50m

1:1

50m

50m

1:1

1:1:1

1:1

4th floor

3rd floor

2nd floor

1st floor

ground floor

Outdoor Antenna

Gain: 18 dBi

Indoor Antenna

Gain: 9dBi

Target Indoor Coverage Building

7/8'' Cable

Loss: 4dB / 50mCable length : 25m

-50 dBm

4th Floor

3rd Floor

1st Floor

Ground Floor

2nd Floor


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Repeater Application examples

Coverage for low traffic area

Remote valley

Tunnel

Underground coverage

needs

decoupling > amplification


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Wave Propagation in Tunnels

The tunnel types include railway tunnel (or metro tunnel),highway tunnel.

Highway tunnel is wide, select the antennas with a larger

size to obtain a higher gain, coverage distance is larger.

Railway tunnel is narrow, the antenna size and gain are

greatly restricted. Especially the radio propagation is

greatly affected by passing train.


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Tunnels Coverage

If outside tunnel and within the tunnel belong to the differencecell, handover problem will occur. To solve this problem, can

consider adopting the following methods:

Adopt the bi-directional antenna for the tunnel coverage, because

it can provide enough overlapping area for handover.

Enable special handover algorithms, such as fast level fall

handover algorithm. In this case, a mobile station can hand over

to another cell when the signal level falls fast.

Select the directional antenna with small front-to-back ratio.


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Contents

1. Planning Basis


3. Advance Planning

4. Advance Technology for improving


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Transmitting diversity

TDMA

Frame

Delayed

TDMA

Frame

TDMA

Frame

1~2 Symbols

TRXB

TRXA


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Two TRXs transmit the same signal with 7.4ustime delay.

Improving downlink coverage based on mutualexchange theory.

Generally 3dB downlink gain from transmittingdiversity.


TRXA

TRXB


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PBT(Power Booster Technology)

Adopt the in-phase synthesizing technology.

Generally PBT can generate 2dB downlinkgain.

PA

RF

PA

Synthesizer

DUP

LEX

RF

BB


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Dynamic PBT

This technology is based on timeslots, allows a calling

subscriber to use a timeslot in other TRX.

When the receive level is lower , channels corresponding

to identical timeslots in adjacent carriers stop delivering

services temporarily.

At this time, the RF channel in the service timeslot and

the auxiliary channel in the adjacent carrier transmit

identical signals, whose phase is also the same. Thecombined signals are stronger, thus improving the

receiving quality for the subscriber.

PBT(P B t


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PBT(Power BoosterTechnology)


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4-way receiving diversity

Compared with 2-way receiving diversity,

4-way receiving diversity gets more 3~5dB

uplink gain.

RF1

RF2

RF3

RF4

BB

>120%R

2WRD

4WRD

R


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AMR-HR TCH/AHS7.95

TCH/AHS7.4

TCH/AHS6.7

TCH/AHS5.9

TCH/AHS5.15

TCH/AHS4.75

Experiment 1b - Test R es

1. 0

2. 0

3. 0

4. 0

5. 0

Condit ion

M O S

Sel. Requi

AMR-HR

EFR

FR

HR

Sel. Requir. 3.99 3.99 3.99 3.14 2.74 1.50

AMR-HR 4.11 4.04 3.96 3.72 3.38 3.10 2.00

EFR 4.21 4.21 3.74 3.34 1.58

FR 3.50 3.50 3.14 2.74 1.50

HR 3.35 3.24 2.80 1.92

No Erro rs C/I=19 dB C/I=16 dB C/I=13 dB C/I=10 dB C/I= 7 dB C/I= 4 dB

AMR


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Gain of Advance Technology

Gain

Transmitting diversity 3dB

PBT 2dB

AMR 5dB(when EFR lower than

5%,compare with FR)

4-way receiving diversity 3~5dB(uplink)


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Transmission delay t

Transmission delay t

TA

The mobile phone should

send the signal in advance!!

Timing Advance (TA)


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Dual Timeslot Extended Cell

Delay63

Modulation range

Normal cell

Dual timeslot extended cell


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To support MS signals with a delay exceeding 63bit,

the 2-timeslot cell can bind the even and odd

timeslots, as if a TDMA frame in the extended cell

only has four channels: 0/1, 2/3, 4/5, and 6/7. Only

channel 0, 2, 4, and 6 can be assigned for the MS.

B0 B2 B3B1 B4 B5 B6 B7

0/1 2/3 4/5 6/7


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The dual-timeslot function is based on the concentric cell. Thecarrier in the underlay cell is configured as the 2-timeslot carrier.

The carrier on the overlay cell is configured as a common cell.

When the cell is configured as a 2-timeslot cell, the concentric cell

attribute of this cell is automatically set to the concentric cell.

If all carriers in the cell must be configured as 2-timeslot carrier,such solution is called the cell-level 2-timeslot solution. In this

case, all carriers are configured in the overlay cell.

If some carriers in the cell are configured as common carriers and

others as 2-timeslot carriers, the BCCH is located on the 2-timeslot

carriers, such solution is called carrier-level 2-timeslot solution. Inthis case, the 2-timeslot carriers are configured in the underlaid

cell and the common carriers are configured in the overlaid cell.


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Assignment of Extended Cell

Type Assignment Strategy

Imm-assignment Underlaid

Assignment Depend on assign optimum

layer

Intra-BSC HO Underlaid

In-coming BSC HO Underlaid


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Configuration

Modify the cell as double timeslot extended cell.


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Configuration


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6 OMF005601 Coverage Planning ISSUE1.0

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