tma theory and application

8/13/2019 TMA Theory and Application

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Comb a Te lecom Ltd

TMA Theory Application


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2008 Comba Telecom, All Rights Reserved2

Topics

1. TMA introduction

What is a TMA and accessories? TMA portfolio Key specs and competitive 2. Performance enhancement

GSM TMA application WCDMA application GSM and WCDMA comparison3. TMA trail performance and statistic analysis How to choose a right site for TMA trail Statistic analysis4. Trouble shooting


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What is a TMA System?

What is a TMA?

A Low noise receiveramplifier used to improvethe up-link sensitivity of theBTS or Node B.

Why is it necessary? To extend and maximize

coverage by providingnetwork balance

To improve the quality of

service to the subscriber To reduce the infrastructurecost to the operator

To reduce intra cell noise

BTS

TMA

PowerSupply

BTS

Antenna

TMA

LNA


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Increasing Cell Radius

A TMA located on the tower top can increase uplink range by50% and bring the cell into balance.

1700 - 2200MHz GSM & WCDMA systems virtually demandTMAs due to higher path loss and limited mobile transmit power.

The r isk of *not* us in g a TMA is los t c a lls near the cel lboundary.

Downlink

Uplinkwithout TMA

Uplink

with TMA


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Advantages of TMA

Extended network coverage Remove up-link limitation

Improved Network Quality Fewer dropped calls

Higher call throughput Satisfied subscribers Reduces MS output power

Longer battery life andless interference.

Reduced infrastructure cost Fewer sites

Disadvantages

Reduces the overall MeanTime Between Failure(MTBF) (with block diagramintroduction)

Maintenance andsupervision is more difficult.

Tower-Mounted Amplifiers (TMA)

ANT0ANT0 ANT1ANT1

Node BNode B Node B1Node B1To RCUTo RCU

TxFil

Rx1 Fil

Rx2 Fil

Rx-Bypass

Bias Teeand Lightning

Protection

TxFil

Rx1 Fil

Rx2 Fil

Rx-Bypass

R S 4 8 5 A

LNALNA

LNALNA

LNA

LNALNA

LNA

LNASupervisionand AlarmGeneration

Unit

LNASupervisionand AlarmGeneration

Unit

Modem

Modem

DC GND

R S 4 8 5 B

LightningProtection

DC Power

LNALNA

LNALNA

LNA

LNALNA

LNA

DC GND


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TMA Accessaries


7/58 2008 Comba Telecom, All Rights Reserved7

What comprises a TMA System?

It consists of 3 main components:

Tower Mounted Amplifier A low noise amplifier with bypass switch.

Current Injector or Bias Tee Facilitates injection of dc power onto the RF cable.

Power Distribution & Management (PDM) provides power and alarm handling up to 6 TMAs.



Power Distribution Management Unit (PDM)

Converts BTS voltage (-48VDC or +24VDC) to +12 VDC.

Power distribution to the TMA via a CIN. Supervises TMA current consumption.

+12V +12V

BTS Sector

TMA

-48V

TMA

Tx/Rx Rx

Antenna

ANT ANT

BTS BTS To BTS Alarm Relay Contacts

BT

Power Distribution & Management



Bias Tee (Current Injector)

Injects dc power onto the

feeder for the TMA. Acts as a surge protector. N or 7/16 connectors in any

combination. IP65, weather protected for

outdoor environment.

DCInput

TMA BTS

Spark gap

/4 /4



Bias Tee Connection

ANT port connects to feeder cable leading to antenna

BTS port connects to feeder cable leading to BTS Two types of bias tee :

Model Connector Type

BT-M1 ANT 7/16 DIN-Female

BTS 7/16 DIN-Male

BT-M2 ANT 7/16 DIN-Male BTS 7/16 DIN-Female



TMA Portfolio

CDMA single TMA (25MHz) band width

GSM single band TMA(25MHz) GSM twin band TMA(25MHz)--- AISG compliance and No AISG EGSM single band TMA(35MHz) DCS1800 single TMA DCS1800 Twin TMA--- AISG compliance and No AISG PCS1900 Twin TMA---AISG compliance and No AISG UMTS2100 twin TMA--- AISG compliance and No AISG



Single Sector power connection

+12V +12V

BTS

-48V

TMA

Tx/Rx Rx

Antenna

ANT ANT

BTS BTS

BT To BTS Alarm

Relay Contacts

Power Distribution & Management

+12V +12V

BTS

-48V

TMA

Tx/Rx Rx

Antenna

ANT ANT

BTS BTS

BT

More Popular



TMA Portfolio

AISG/No AISG

product development process

IOT test with or without PDM (need some plots)with BTSwith Node B

with or without AISG compliance



Status of Comba TMA

Specs introduction

Normal RF specs High and low temperature test

Key focus from customer side waterproof lightning protection salt mist other reliability compare with customer IOT compatible with Base station



Enhancement improve



GSM Calculation of Receiver Sensitivity

Thermal noise floor is given by

The noise at the input of a receiver is known as the receiver noisefloor, and is given by

where NF r is the noise figure of the receiver

The sensitivity of a receiver is given by

For GMSK modulation, we need a detection SNR of 9 dB If the receiver noise figure is 2 dB, then the sensitivity is

dBm 30log10dBW log10

kTBkTB P n

dBW log10 r nr NF kTB P

SNR NF P SNR P P r nnr sens

dBm11092121 sens P

Input A p1 1 F1


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The overall noise figure, NF T, of a number of cascaded devicescan be calculated from Friis' equation:

where gain and noise factor values are in linear units.

11log10

21

3

1

21 GG

F G

F F NF T

Input Ap11, F1 , , The noise factor of the first stage contributes significantly to the

overall noise figure. The noise figure of a passive device is equal to its insertion loss.

NF in Cascade Amplifier Stages


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Sensitivity Improvement

LNA

BTS Receiver

BTS LNA NF _ Feeder and Jumpers

dB L f 4

-90

-100

-110

-130

dBm

-120

10 dB

3 dB

Thermal Noise Noise Figure in BTS

AB C

BTS LNAG _

Without TMA

dB NF BTS LNA 3 _ dBG BTS LNA 14 _

6 dB

BTS Receiver

Feeder andJumpers

dB L f 4

-90

-100

-110

-130

dBm

-120

10 dB

Thermal Noise Noise Figure in Active Component

AC D

5.5 dB

LNA LNA

TMA NF TMAG

TMA

B BTS LNA NF _

With TMA

dB NF TMA 5.1dBGTMA 11

8.5 dB

dB NF BTS LNA 3 _ dBG BTS LNA 6 _

8.5 dB

BTS LNAG _


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TMA RF Impact

BPF

TMA

i

Si gnal 1

Si gnal 2

TMAi nput Noi se Ther mal Noi sef l o r

SNR1

LNA

Si gnal at ant enna t er mi nal Si gnal i nt of eeder

Si gnal af t er f eeder l osses

No TMA

Si gnal af t er

Si gnal af tf eeder l os

Wi t hTMA


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BTS without TMA

Example 1

Consider a GSM 1800 BTSuplink arrangement as shown. Assuming that a detection

SNR of 9 dB is needed,determine the minimum BTS

receive power level needed(after the antenna).

RX

Detection

Duplexer BTS

NF = 5 dB

S/N = 9 dB

Loss = 1 dB

Loss = 3.3 dB

Jumper

Jumper

Feeder cable7/8", 50 m

Loss = 0.5 dB

Loss = 0.5 dB

Antenna

Received power

RX sensitivity


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BTS without TMA

Solution

Thermal Noise Floor

Receiver sensitivity

Received power

dBm

dBW

kTB P n

121

151

102002901038.1log10

log10323

dBm

P sens 071

59121

dBm

P r 01.71

5.03.35.01107RX

Detection

Duplexer BTS

NF = 5 dB

S/N = 9 dB

Loss = 1 dB

Loss = 3.3 dB

Jumper

Jumper

Feeder cable7/8", 50 m

Loss = 0.5 dB

Loss = 0.5 dB

Antenna

Received power

RX sensitivity sens P

r P


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Link Budget Overview

Results

OutputPower Losses

(Cable,Combiner, ) BS

Antennagain Path-

loss Load(Interference

margin)

SHOGain

MSantenna

gain

UE /bodyloss

Processing Gain(de-spreading)

MDCgain

POWER LEVEL

E c /I 0

E b /N 0

Capacity

Coverage


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BTS with TMA

Solution

Overall noise figure, NF T

Received power

Improvement in sensitivity

dB12.3

05.2log10

5.017.038.1log10

1010110

10110

10log10 106.51012105

1012

106.5104.1

dBm

P r

08.41

5.012.39121

dB70.64.1087.101

RX

Detection

Duplexer BTS

S/N = 9 dB

Loss = 3.3 dB

Received power

RX sensitivity

NF = 1.4 dB Gain = 12 dB

Loss = 0.3 dB Overall

Loss = 0.5 dB

NF = 5 dB

Loss = 1 dB

Loss = 0.5 dB

Loss = 0.5 dB Noise Figure


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WCDMA Sensitivity Improvement

In WCDMA, the sensitivity of an unloaded Node B for a particular

radio access bearer (RAB) is given by

where

P sr is the receiver noise floor (dBm) E b/ N 0 is the bit energy to noise power spectral density for the

particular RAB (dB)G p is the processing gain for the particular RAB (dB)

The processing gain is defined as

where

W is the spread bandwidth or chip rate (Hz) Rb is the data rate of the RAB (bits/sec)

pbnr sr G N E P P 0

(dB) log10b

p

R

W G


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Example 2

Consider the BTS receivesystem with TMA. Determine the improvement in

the minimum BTS receivedpower.

BTS with TMA

RX

Detection

Duplexer BTS

S/N = 9 dB

Loss = 3.3 dB

Received power

RX sensitivity

NF = 1.4 dB Gain = 12 dB

Loss = 0.3 dB Overall

Loss = 0.5 dB

NF = 5 dB

Loss = 1 dB

Loss = 0.5 dB

Loss = 0.5 dB Noise Figure


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The receiver noise floor related to the receiver noise figure by

Sensitivity of Node B can be expressed by

Receiver noise figure has a great impact on the receiversensitivity.

pbt G N E NF N 0

r t nr NF N P

pbnr sr G N E P P 0


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Assumptions Jumper Cable Losses

= 0.5 dB Feeder Cable Loss

= 3 dB Bias-Tee Loss

= 0.15 dB Duplexer Loss

= 1 dB TMAs Uplink Gain

= 12 dB TMAs Noise Figure

= 1.4 dB Node B Receiver Noise

Figure = 5 dBNode B without TMA

F L

2 S P

Rx

Det

Rx

Det

1 J L

2 J L

d L

r NF

1 S P

Node B with TMA

TMA

Bias Tee

F L

TMA NF TMA G

2 S P

Rx

Det

Rx

Det

1 J L

2 J L

3 J L

DPX L

r NF

s NF

1 S P BT L


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Assumptions Jumper Cable Losses

= 0.5 dB Feeder Cable Loss

= 3 dB Bias-Tee Loss

= 0.15 dB Duplexer Loss

= 1 dB TMAs Uplink Gain

= 12 dB TMAs Noise Figure

= 1.4 dB Node B Receiver Noise

Figure = 5 dBNode B without TMA

F L

2 S P

Rx

Det

Rx

Det

1 J L

2 J L

d L

r NF

1 S P

Node B with TMA

TMA

Bias Tee

F L

TMA NF TMA G

2 S P

Rx

Det

Rx

Det

1 J L

2 J L

3 J L

DPX L

r NF

s NF

1 S P BT L


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Without TMA

For a speech RAB, the processing gain is given by

The unloaded Node B sensitivity, measuredat the BTS port, is given by

If the sensitivity is measured at the antennaport, then

Node B without TMA

F L

2 S P

Rx

Det

Rx

Det

1 J L

2 J L

d L

r NF

1 S P

dB252.12

3840log10log10

b p R

W G

dBm124

254510801 pbr t S G N E NF N P

dBm120

5.05.031242102 J J F pbr t S L L LG N E NF N P


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With TMA

To calculate Node B sensitivity with TMA,the total noise figure of the receiver systemis computed using Friis equation.

Total loss between TMA and receiver is

Overall system noise figure measured frominput of TMA is

Node B with TMA

TMA

Bias Tee

F L

TMA NF TMA G

2 S P

Rx

Det

Rx

Det

1 J L

2 J L

3 J L

DPX L

r NF

s NF

1 S P BT L

dB15.5115.035.05.0

21 DPX BT F J J t L L L L L L

dB95.2

10/10110

10110

10log10

/11

log10

10/15.510/12

10/5

10/12

10/15.510/4.1

t TMA

r

TMA

t TMAtotal LG

F G L

F NF


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System sensitivity with TMA, measured at the antenna port, cannow be calculated by

Sensitivity improvement is quantified by

Improvement is derived mainly from lownoise figure and high gain of TMA.

12 dB gain in LNA does not result in a12 dB improvement in sensitivity, dueto the noise contribution of the LNA.

Node B with TMA

TMA

Bias Tee

F L

TMA NF TMA G

2 S P

Rx

Det

Rx

Det

1 J L

2 J L

3 J L

DPX L

r NF

s NF

1 S P BT L

dBm6.125

5.025495.2108

' 302 J pbtotal t S LG N E NF N P

dB6.51206.125' 22 _ 2 S S impS P P P


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Coverage Area Enhancement

In WCDMA, coverage of a cell is uplink-limited

lower transmit power of the UE, as compared to Node B. UE is located at cell border area may be able to receive a good

CPICH on DL, but may not have sufficient power on UL toconnect to the Node B. Call may not be connected

If a call can be initiated, itcan be dropped easily dueto the weak signal on uplinkdirection.

Also apply to UEs in neighbouringcells handing over to this cell.

CPICH power is normally reducedat Node B to maintain a balanced link, resulting in a reducedcoverage of the cell.

DL DCH &Pilot

ULDCH

Node B

UE


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Recei ver Sensi t i vi t y. ( TMANF1 . 5dB, BTSNF5 dB)

- 111. 00

- 109. 00

- 107. 00

- 105. 00

- 103. 00

- 101. 00

- 99. 00

- 97. 00

1 2 3 4 5

Cabl el oss( dB)

NoTMA

TMAGai n 6

TMAGai n 12

TMAGai n 15


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Differences GSM / CDMA

GSM is a time domain system ie a single resource to single userwhereas CDMA is code division system ie single resource tomultiple users (power is the shared resource)

GSM quality levels vary and over quality is wasted

CDMA have a fixed quality as target in the power control loop andcan trade quality against data rate. The varying parameter is MS(UE) Tx power.

GSM RF performance is (almost) load independent, CDMA

performance alters with load (load curve & cell breathing)


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Processing Gain

Due to processing gain, spread signal is below the noise level.

R e q u i r e

d S i g n a

l P o w e r

Receiver Noise Level(e.g. -105dBm)

PS 384 kbps

CS 64 kbps

Voice 12.2 kbps

+10

+18

+25

ProcessingGain (dB)

dB N E b 40 dB N E b 20

dB N E b 10

b p R

W G log10

-21dB

-16dB

-9dB

),()()(00

dBGdB N E dB

I E pbc

dB

voice I E c 17

)(0

),()()(0

0 dBGdB N E

I dB E pb

c


36/58


Interference Margin

The more number of users in a cell, the higher is the interferencelevel, which will limit the capacity of WCDMA.

Interference margin is determined from UL/DL loading values. Loading causes the receiver noise floor to rise and hence reduces

the available link budget.

][ 1log10 dB I Margin

10

20

6

3

1.25

25% 50% 75% 99%

Margin I

Loading Factor

dB

I n t e r f e r e n c e

M a r g

i n

10

20

6

3

1.25

25% 50% 75% 99%

Margin I

Loading Factor

dB

I n t e r f e r e n c e

M a r g

i n


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CDMA Load Curve

The load curve shows the relation between noise rise and load.

It always starts in the system noise floor and then have thesame load related increase, independent of starting point, +3 dB@ 50% load, +6 dB @75%.

100% represents the unreachable pole capacity

Decreased noise figure means decreased UE Tx power.Therefore a greater number of users can use the system for agiven interference level


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CDMA Power / Load Curve

0

3

6

9

12

0% 25% 50% 75% 95%

Without TMAWith TMA

The load curve isshifted 3 to 5 dB

down, for every load. Improvement in coverage

or data rate fromreduction of required UE

output power


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What does the TMA do for CDMA?

The TMAs enable the mobile to use its power for efficientcommunication rather than for overcoming noise. Thismeans: Extended c overage rang e Higher p i lo t level can b e used Reduced interference in both own and adjacent cells

Less b at tery dra in on the mo bi le , m eaning long er talkt ime

Greater margins for fading and c ontro l range. Higher data capaci ty on th e netwo rk


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Coverage & Capacity

140

145

150

155

160165

170

175

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

7 0 0

8 0 0

9 0 0

1 0 0 0

1 1 0 0

1 2 0 0

1 3 0 0

DL Div.

DL Ref

UL TMA

DL-diversity.

6x20W

3 sectorized

3x20W

DL-omni

1x20W

TMA-ULdB

kB/s

UL-no TMA

R l f i l


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Results from trialCDMA Ms Tx power

-50

-40

-30

-20

-10

0

10

0 1 2 3 4 5 6 7 8 9 10

Distance

U E T X P o w e r [ d B m ]

------Without TMA

------ With TMA

4,2 dB reductionof average TX

powerPower reduction veryconsistent all alongthe drive path


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Conclusions

TMAs make a significant contribution to improving

system performance The benefits can be seen in coverage and capacity

for WCDMA and coverage for GSM Whilst performance improvements will be seen

with no BTS adjustment, it is important to optimisethe BTS parameters for maximum benefits.


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How to choose a right trail for TMA

The Process:

Show some statistics come in


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TMA Improvement Calculations

Sector A Feeder loss = 4 dB Improvement in Rx pwr

= -104 - (-109.3)= 5.3 dB

Sector B

Feeder loss = 3.35 dB Improvement in Rx pwr= -104.7 - (-109.9)= 5.3 dB

Sector C

Feeder loss = 2.21 dB Improvement in Rx pwr

= -105.8 - (-110.3)= 4.5 dB

CELL2 TR 2/ RX218 017 TH FL OOR( EL=60. 00 )

CELL3 RXD430017 TH FL OOR( EL= 60 . 00 )

o

o

CELL 3TX 4/ RX430 0o

17 TH FL OOR( EL= 60 . 00 )

CELL2 RXD2180 o

17 TH FL OOR( EL=60. 00 )

EQ UI PM EN T15TH FL

TEL ECO MS I

CELL1 TX 0/ RX0

o

22NDFLO OR( EL=7 0.

22NDFLO OR( EL=7 0.CELL 1RX 0


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Performance Measurement

Handover Request Ratio due to

Uplink Signal (UL_RxLev) Downlink Signal (DL_RxLev) Uplink Quality (UL_RxQual) Downlink Quality (DL_RxQual) Power Budget (PB)

Drop Call Measurements TCH Drop Call Rate (Drop #2) Subscriber Perceived Drop Call Rate (Drop #3)

ErlangMin/Drop


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HO Performance - Sector 1

ART - sector1

0.00%

10.00%

20.00%

30.00%

40.00%

50.00%

60.00%

70.00%

80.00%

90.00%

1 0 / 1 / 9 8

1 0 / 8 / 9 8

1 0 / 1 5 / 9 8

1 0 / 2 2 / 9 8

1 0 / 2 9 / 9 8

1 1 / 5 / 9 8

1 1 / 1 2 / 9 8

1 1 / 1 9 / 9 8

1 1 / 2 6 / 9 8

1 2 / 3 / 9 8

1 2 / 1 0 / 9 8

1 2 / 1 7 / 9 8

1 2 / 2 4 / 9 8

1 2 / 3 1 / 9 8

1 / 7 / 9 9

1 / 1 4 / 9 9

1 / 2 1 / 9 9

1 / 2 8 / 9 9

2 / 4 / 9 9

2 / 1 1 / 9 9

2 / 1 8 / 9 9

2 / 2 5 / 9 9

HO_REQ_UL_RATIO HO_REQ_DL_RATIO HO_REQ_UQ_RATIO HO_REQ_DQ_RATIO HO_REQ_PB_RATIO

TMA Installation TMA Changeout


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ART- sector 2

0.00%

10.00%

20.00%

30.00%

40.00%

50.00%

60.00%

70.00%

80.00%

90.00%

1 0 / 1 / 9 8

1 0 / 8 / 9 8

1 0 / 1 5 / 9 8

1 0 / 2 2 / 9 8

1 0 / 2 9 / 9 8

1 1 / 5 / 9 8

1 1 / 1 2 / 9 8

1 1 / 1 9 / 9 8

1 1 / 2 6 / 9 8

1 2 / 3 / 9 8

1 2 / 1 0 / 9 8

1 2 / 1 7 / 9 8

1 2 / 2 4 / 9 8

1 2 / 3 1 / 9 8

1 / 7 / 9 9

1 / 1 4 / 9 9

1 / 2 1 / 9 9

1 / 2 8 / 9 9

2 / 4 / 9 9

2 / 1 1 / 9 9

2 / 1 8 / 9 9

2 / 2 5 / 9 9


TMA Installation

TMA Changeout


48/58



ART-sector 3

0.00%

10.00%

20.00%

30.00%

40.00%

50.00%

60.00%

70.00%

80.00%

90.00%

100.00%

1 0 / 1 / 9 8

1 0 / 8 / 9 8

1 0 / 1 5 / 9 8

1 0 / 2 2 / 9 8

1 0 / 2 9 / 9 8

1 1 / 5 / 9 8

1 1 / 1 2 / 9 8

1 1 / 1 9 / 9 8

1 1 / 2 6 / 9 8

1 2 / 3 / 9 8

1 2 / 1 0 / 9 8

1 2 / 1 7 / 9 8

1 2 / 2 4 / 9 8

1 2 / 3 1 / 9 8

1 / 7 / 9 9

1 / 1 4 / 9 9

1 / 2 1 / 9 9

1 / 2 8 / 9 9

2 / 4 / 9 9

2 / 1 1 / 9 9

2 / 1 8 / 9 9

2 / 2 5 / 9 9


TMA Installation TMA Changeout


49/58


Drop #3 Performance - Sector 1moving average for sector 1 (drop #3)

0.00%

0.50%

1.00%

1.50%

2.00%

2.50%

3.00%

3.50%

1 0 / 1 / 9 8

1 0 / 8 / 9 8

1 0 / 1 5 / 9 8

1 0 / 2 2 / 9 8

1 0 / 2 9 / 9 8

1 1 / 5 / 9 8

1 1 / 1 2 / 9 8

1 1 / 1 9 / 9 8

1 1 / 2 6 / 9 8

1 2 / 3 / 9 8

1 2 / 1 0 / 9 8

1 2 / 1 7 / 9 8

1 2 / 2 4 / 9 8

1 2 / 3 1 / 9 8

1 / 7 / 9 9

1 / 1 4 / 9 9

1 / 2 1 / 9 9

1 / 2 8 / 9 9

2 / 4 / 9 9

2 / 1 1 / 9 9

2 / 1 8 / 9 9

2 / 2 5 / 9 9

ma


50/58


Drop #3 Performance - Sector 2moving average for sector 2 (drop #3)

0.00%

0.20%

0.40%

0.60%

0.80%

1.00%

1.20%

1.40%

1.60%

1.80%

2.00%

1 0 / 1 / 9 8

1 0 / 8 / 9 8

1 0 / 1 5 / 9 8

1 0 / 2 2 / 9 8

1 0 / 2 9 / 9 8

1 1 / 5 / 9 8

1 1 / 1 2 / 9 8

1 1 / 1 9 / 9 8

1 1 / 2 6 / 9 8

1 2 / 3 / 9 8

1 2 / 1 0 / 9 8

1 2 / 1 7 / 9 8

1 2 / 2 4 / 9 8

1 2 / 3 1 / 9 8

1 / 7 / 9 9

1 / 1 4 / 9 9

1 / 2 1 / 9 9

1 / 2 8 / 9 9

2 / 4 / 9 9

2 / 1 1 / 9 9

2 / 1 8 / 9 9

2 / 2 5 / 9 9

ma


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Drop #3 Performance - Sector 3

moving average for sector 3 (drop #3)

0.00%

0.50%

1.00%

1.50%

2.00%

2.50%

1 0 / 1 /

9 8

1 0 / 8 /

9 8

1 0 / 1 5

/ 9 8

1 0 / 2 2

/ 9 8

1 0 / 2 9

/ 9 8

1 1 / 5 /

9 8

1 1 / 1 2

/ 9 8

1 1 / 1 9

/ 9 8

1 1 / 2 6

/ 9 8

1 2 / 3 /

9 8

1 2 / 1 0

/ 9 8

1 2 / 1 7

/ 9 8

1 2 / 2 4

/ 9 8

1 2 / 3 1

/ 9 8

1 / 7 / 9

9

1 / 1 4

/ 9 9

1 / 2 1

/ 9 9

1 / 2 8

/ 9 9

2 / 4 / 9

9

2 / 1 1

/ 9 9

2 / 1 8

/ 9 9

2 / 2 5

/ 9 9

ma


52/58


Summary of Performance

Radio Parameters Before After

Handover Request Ratio due to- Uplink Signal (UL) 24.27 % 0.80 %

- Downlink Signal (DL) 6.12 % 14.42 %

- Uplink Quality (UQ) 2.57 % 1.20 %

- Downlink Quality (DQ) 8.50% 5.93%

- Power Budget (PB) 58.40% 77.46%

Drop Call Measurements

- TCH Drop Call Rate (Drop #2) 1.16 0.98

- Subscriber Perceived Drop Call Rate (Drop #3) 2.66 1.74- ErlangMin/Drop 62.99 85.81


53/58


Summary of Performance

The uplink is stronger than the downlink (more HO due to DL).

Majority of the handovers are due to better servers (HO due to PB). Generally, uplink quality has improved (lesser HO due to UQ). Drop calls has reduced. ErlangMin/Drop has increased to 85.81. Neighbouring cells performance would also improve

because calls that are handed over to them are due to better signalstrength.

Coverage or whether a subscriber can initiate a call is dependenton the downlink signals. In what used to be boundary coverageareas, the subscribers can now make AND expect to finish the

calls.


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Guidelines on Site Selection for TMA

High TCH Drop Call Rate or High HO Failures

HO reason or Drop reason is due to poor uplink signal leveland/or quality Handover due to Power Budget is low (~ 50% or less) High feeder loss (> 2dB) High BTS output power or low combining loss

Link is breaking on uplink


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TMA Trouble Shooting

VSWR test after installation

Short circuits alarming Low current alarming


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Bias Tee Connection

Bias tee must be position in front of lightning protection devices

Lightning protection devices placed in front of bias tee will causedbias tee to malfunction

BTS

ANT

BTS

BTS

ANT

ANTENNA


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Q&A

tma theory and application

Documents