00-Conspectus of Planning and Optimization of CDMA 1

8/6/2019 00-Conspectus of Planning and Optimization of CDMA 1

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ORG000101Conspec t us of Planning and

Opt im izat ion of CDMA 1X Netw ork

ISSUE1.0

ORG000101Conspec t us of Planning and

Opt im izat ion of CDMA 1X Netw ork

ISSUE1.0

Mobile Network Curriculum

Development Section


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Study objectiveStudy objective

It is required that after the course

study, you should:

Have a general concept about networkplanning

Have an understanding ofcharacteristics of CDMA networkplanning

Have an understanding of the maincontents of network planning

Have an understanding of the maincontents of network optimization


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Contents of the courseContents of the course

Chapter 1 CDMA 1X Network Planning

Process & Characteristics


Chapter 3 CDMA 1X Network

Optimization


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Chapter 1 CDMA 1X Network Planning Process &

Characteristics

Chapter 1 CDMA 1X Network Planning Process &

Characteristics

l Objectives of network planning

l CDMA 1X Network planning flow

l Difference between network

planning of CDMA and GSM


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To establish the largest radio networkboth in capacity and coverage with a

certain cost and under the

precondition of meeting the QoS of

network, and further, adapt to the

future network development and

expansion.

To establish the largest radio networkTo establish the largest radio networkboth inboth in capacitycapacity andandcoveragecoverage with awith a

certaincertain costcostand under theand under the

precondition of meeting theprecondition of meeting the QoSQoS ofof

network, and further, adapt to thenetwork, and further, adapt to the

future network development andfuture network development and

expansion.expansion.

Objectives of network planningObjectives of network planning

CoverageCoverage QualityQuality CostCostCapacityCapacity

Realization of excellent balance of all aspects via network planning


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CDMA 1X Network planning flowCDMA 1X Network planning flowCDMA 1X Network planning flow

Analysis of

traffic coverage

Emulation

Site survey

System design

Installation and

Integration

Network optimization


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Difference of Network Planning Between CDMA

and GSM

Difference of Network Planning Between CDMA

and GSM

CDMACDMA

Dy n a mi c c o v e r a g e i s

r e l a t e d t o c a p a c i t y

a n d i n t e r f e r e n c e

Dy n a mi c c o v e r a g e i sDy n a mi c c o v e r a g e i s

r e l a t e d t o c a p a c i t yr e l a t e d t o c a p a c i t y

a n d i n t e r f e r e n c ea n d i n t e r f e r e n c e

S i mp l e , N= 1S i mp l eS i mp l e ,, N= 1N= 1

I n t e r f e r e n c el i mi t e d

I n t e r f e r e n c eI n t e r f e r e n c el i mi t e dl i mi t e d

Mu l t i - s e r v i c e

a n d h i g h s p e e d

Mu l t i - s e r v i c eMu l t i - s e r v i c e

a n d h i g h s p e e da n d h i g h s p e e d

GS MGS M

P r e d i c t i o nP r e d i c t i o nP r e d i c t i o n

S t a t i c c o v e r a g eS t a t i c c o v e r a g eS t a t i c c o v e r a g e

Co mp l e x , k e y

t e c h n o l o g y

Co mp l e x , k e yC o mp l e x , k e y

t e c h n o l o g yt e c h n o l o g y

S t a t i c c a p a c i t yS t a t i c c a p a c i t yS t a t i c c a p a c i t y

Vo i c e s e r v i c e

a s b o d y

Vo i c e s e r v i c eVo i c e s e r v i c e

a s b o d ya s b o d y

P l a n n i n gme t h o d

P l a n n i n gP l a n n i n g

me t h o dme t h o d

Co v e r a g eCo v e r a g eCo v e r a g e

F r e q u e n c yp l a n n i n g

F r e q u e n c yF r e q u e n c y

p l a n n i n gp l a n n i n g

Ca p a c i t yp l a n n i n gCa p a c i t yCa p a c i t yp l a n n i n gp l a n n i n g

Da t a s e r v i c ep l a n n i n g

Da t a s e r v i c eDa t a s e r v i c e

p l a n n i n gp l a n n i n g

P r e d i c a t i o n

E mu l a t i o n

P r e d i c a t i o nP r e d i c a t i o n

E mu l a t i o nE mu l a t i o n


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QuestionQuestion

lWhat are the objectives of

networking planning?

lPlease describe the process

of network planning.

lDifferences between network

planning of CDMA and GSM?


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Optimization


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Chapter 2 CDMA 1X Network PlanningChapter 2 CDMA 1X Network Planning

ll Section 1 Coverage PlanningSection 1 Coverage Planning

ll Section 2 Capacity PlanningSection 2 Capacity Planning

ll Section 3 Power PlanningSection 3 Power Planning

ll Section 4 Handoff PlanningSection 4 Handoff Planning


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Link budget modelLink budget modeLink budget model

Radio coverage

Electric wave

propagationService

requirement

MS

performance

Equipment

parameter

Radio resource

management

Soft phenomenonof CDMA


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Link budget modelLink budget modelLink budget model

Forward link

Reverse link

Both forward and reverse links within the coverage area should rBoth forward and reverse links within the coverage area should reach balanceeach balance

P a r a me t e r r e l a t e d t o e q u i p me n t : t r a n s mi s s i o n p o we r , r e c e i v e r

s e n s i t i v i t y , p a r t s a n d f e e d e r l o s s , a n t e n n a l o s s P a r a me t e r s r e l a t e d t o r a d i o e n v i r o n me n t : f a s t f a d i n g ma r g i n ,s l o w f a d i n g ma r g i n a n d c l u s t e r l o s s P a r a me t e r r e l a t e d t o CDMA t e c h n o l o g y : s y s t e m l o a d a f f e c t i o n ,s o f t h a n d o f f g a i n a n d E b / Nt P a r a me t e r s r e l a t e d t o s e r v i c e : s e r v i c e t y p e , d a t a r a t e , ma x i mu mt r a n s mi s s i o n p o we r o f e a c h t r a f f i c c h a n n e l P r o p a g a t i o n mo d e l : c l a s s i c a l - Ok u mu r a Ha t a mo d e l , e t c .

P a r a me t e r r e l a t e d t o e q u i p me n t : t r a n s mi s s i o n p o we r , r e c e i v e rt r a n s mi s s i o n p o we r , r e c e i v e r

s e n s i t i v i t y , p a r t s a n d f e e d e r l o s s , a n t e n n a l o s ss e n s i t i v i t y , p a r t s a n d f e e d e r l o s s , a n t e n n a l o s s P a r a me t e r s r e l a t e d t o r a d i o e n v i r o n me n t : f a s t f a d i n g ma r g i n ,f a s t f a d i n g ma r g i n ,s l o w f a d i n g ma r g i n a n d c l u s t e r l o s ss l o w f a d i n g ma r g i n a n d c l u s t e r l o s s P a r a me t e r r e l a t e d t o CDMA t e c h n o l o g y : s y s t e m l o a d a f f e c t i o n ,s y s t e m l o a d a f f e c t i o n ,s o f t h a n d o f f g a i n a n ds o f t h a n d o f f g a i n a n d E b / NtE b / Nt P a r a me t e r s r e l a t e d t o s e r v i c e : s e r v i c e t y p e , d a t a r a t e , ma x i mu ms e r v i c e t y p e , d a t a r a t e , ma x i mu mt r a n s mi s s i o n p o we r o f e a c h t r a f f i c c h a n n e lt r a n s mi s s i o n p o we r o f e a c h t r a f f i c c h a n n e l P r o p a g a t i o n mo d e l : c l a s s i c a lc l a s s i c a l -- Ok u mu r aOk u mu r a Ha t aHa t a mo d e l , e t cmo d e l , e t c ..

Cl a s s i f i c a t i o n o f p a r a me t e r s i n v o l v e d i n l i n k b u d g e t o f CDMA 1 X :Cl a s s i f i c a t i o n o f p a r a me t e r s i n v o l v e d i n l i n k b u d g e t o f CDMA 1 X :

Receive/transmit

power

Receive/transmit

powerAntenna gainAntenna gainFeeder lossFeeder loss

Interference

margin

Interference

marginAntenna

gain

Antenna

gainPath LossPath LossTransmit-receive

power

Transmit-receive

powerSoft handoff

gain

Soft handoff

gainFading

margin

Fading

margin


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Link budget parametersLink budget parametersLink budget parameters

E b / Nt p a r a me t e r s e t t i n g o f B T S

2.683.574.265.376.78Vehiclespeed

(100km/h)

3.84.284.785.967.13Vehiclespeed

(30km/h)

2.513.013.644.966.34Vehiclespeed (8km/h)

1.982.473.014.115.57Walking(3km/h)

1.542.152.593.43.5Static (0km/h)

Data service( 153.6kbps )



Dataservice

( 19.2kbps )

Voiceservice

( 9.6kbps )

FER 5%FER 5%FER 5%FER 5%FER 1%

Eb/Nt( dB )


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S e n s i t i v i t y o f S _ B S B T S r e c e i v e r

3 The BTS receiver sensitivity finalizes the minimum receive level required forthe traffic channel to ensure certain call quality.

3 S_BS = Eb/Nt10lg(W/Rb) + 10lg(KTW) + NF_BSEb/Nt Demodulation threshold of BTS receiver can be obtained via link

emulation and on-the-spot survey. It is related to service type, propagation

environment, receiver demodulation performance and configuration

conditions (received diversity of antenna, power control and soft handoff).

Rb data rate (before channel coding)

KT thermal noise density, equaling to -174dBm/Hz under the condition of

normal temperature

W spread spectrum bandwidth

NF_BS receiver noise indices, typical value: 5dB, Huaweis BTS: 3.2dB

The sensitivity can also be affected by interference. Thus the design loadshould be added with interference margin in actual application.

S e n s i t i v i t y o f S _ MS MS r e c e i v e r

3 S_MS = Eb/Nt10lg(W/Rb) + 10lg(KTW) +NF_MSNF_MS MS noise index, and the typical value is 8dB


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Mf s h a d o w f a d i n g ma r g i nMf(dB)= NORMSINV(Edge coverage

probability) r

System margin

Probability

density

Area

Coverage

probability


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S o f t h a n d o f f g a i n G_ HO a n d s h a d o w f a d i n g ma r g i n

In link budget, maximum path losses of both forward and

reverse links are calculated. If the MS is located in the cell

edge, gain brought by soft handoff should also be taken intoconsideration.

During soft handoff, the shadow fading margin satisfying a

certain coverage probability is decreased due to the

existence of independent propagation path, and this gain iscalled soft handoff gain, that is, G_HO, in link budget.



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MI : I n t e r f e r e n c e ma r g i n

The CDMA system is a self-interference one. It is closely relatedto coverage and capacity, and this is reflected on the introductionof interference margin to the link budget.

For the reverse link, different load levels correspond to differentinterference raises. For example, a 3dB interference raisecorresponds to 50% load and a 4dB interference raisecorresponds to 60% load.

For the forward link, the relationship between load and theinterference also exists. But it is hard to perform theorycalculation. Thus emulation is required.

In the link budget, the value for the interference margin isfinalized by the design capacity of system.


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Ci t y l i n k b u d g e t

Example of link budget for reverse linkExample of link budget for reverse link

1.011.181.401.611.841.72Coverage radius ( km )

30.0030.0030.0030.0030.0030.00BS antenna height ( m )

1.501.501.501.501.501.50MS antenna height ( m )

124.76127.02129.59131.79133.82133.90Allowable propagation loss for required coverage (dB)

202020202020Clutter loss ( dB )

5.55.55.55.55.55.5Required shadow fading margin ( dB )

75%75%75%75%75%75%Corresponding edge coverage probability

90%90%90%90%90%90%Required area coverage probability

888888Shadow fading standard deviation ( dB )

0.000.000.000.003.703.70Soft handoff gain ( dB )

0.500.500.500.500.500.50Fast fading margin ( dB )

-117.74-120.00-122.57-124.77-127.50-124.18Receiver sensitivity ( dBm )

3.013.013.013.013.013.01Interference margin ( dB )

50%50%50%50%50%50%Cell load

1.542.152.593.405.005.80Eb/Nt required for demodulation ( dB )

3.203.203.203.203.23.20Receiver noise ( dB )

1.971.971.971.971.971.97Feeder loss ( dB )

15.0015.0015.0015.0015.0015.00Antenna gain of BTS ( dBi )

23.0023.0023.0023.0020.0020.00EIRP ( dBm )

0.000.000.000.003.003.00Human body loss ( dB )

23.0023.0023.0023.0023.0023.00Maximum transmission power of traffic channel ( dBm )

153.6kbps76.8kbps38.4kbps19.2kbps9.6kbps voice9.6kbps voice

CDMA2000-1XIS-95


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The increase of forward power of data service, especially the highspeed data, may result in the BTS power becoming the factor limitingthe BTS coverage scope, which in turn causes that the forwardcoverage is limited.

The forward coverage is closely related to distribution of BTS andsubscribers of different service rates.

In comparison with the reverse coverage, the affection brought bythe data rate to forward coverage is much greater

When planning is performed to the area with high requirements ofhigh speed data, analysis should be made by associating the forwardpower distribution. When the forward coverage is limited, thenplanning should be made according to the forward coverage distance.

Analysis of link budget of forward linkAnalysis of link budget of forward link


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QuestionQuestion

lWhat are the parameter types involved in

CDMA 1X link budget?


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Constitution of interference in CDMA systemConstitution of interference in CDMA system

NotherownTOT PIII ++=

IIownown Interference from the subscribers of local cellInterference from the subscribers of local cell

IIotherother Interference from the subscribers of NeighborInterference from the subscribers of Neighbor

cellscells

PPNN Receiver noiseReceiver noise

IIownownIIotherotherthe main interference componentsthe main interference components


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l Soft blocking of air interface

l Factors affecting the uplink load of sector

Quantity of the subscriber

MS interference of Ncell (neighbor cell)

Setting points of destination FER and Eb/Nt and MS environment

Allocation ratio of voice service and data service

Allocation ratio of data rate service, duty ratio and voice

activation factor, etc.

Power control error.

l Conclusion: The CDMA capacity fluctuates along with the change of

environment

Soft capacity attribute of CDMA 1X system

Soft capacity attribute of CDMA 1X systemSoft capacity attribute of CDMA 1X system


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l The foundation for capacity analysis is traffic measurement and calculation. In addition

to the busy hour Erlang used for voice service, more measurements are required for

packet data service subscribers. The traffic per voice service subscriber is measured by

any of two parameters that can be converted to each other. One is BHE (busy hour

Erlang) per voice service subscriber and the other is throughput per voice service

subscriber in bps calculated as follows Throughput = Traffic strength * data rate *

activation factor.

l The BHE and Throughput calculation for PSD service should be approached in different

way for the reasons: 1. Different channel assignment scheme for PSD; 2. Different

demands of data rate with different subscribers :

System capacity represented by

throughput adopted

rAvS =

Capacity of CDMA 1X systemCapacity of CDMA 1X system


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Reverse capacity model:

)

)1(

)1(

(22

22

222

2

1

0

+

+=

eM

eMXR

W

QB cdma

dtexQt

x

2/2

2

1)(

=

10/)10(ln,)/( == tb NEe

Reverse capacity model of CDMA 1X systemReverse capacity model of CDMA 1X system


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Reverse capacity at different rates and different moving speeds

Reverse capacity of CDMA 1X systemReverse capacity of CDMA 1X system

Static 3km/h 8km/h 30km/h 100km/h

Mean load of the system 50% 50% 50% 50% 50%

Service blocking rate 2% 2% 2% 2% 2%

Interference factor 0.55 0.55 0.55 0.55 0.55

Basic parameter Second order interference factor 0.086 0.086 0.086 0.086 0.086

Power control covariance (dB) 2.5 2.5 2.5 2.5 2.5

Sector factor 2.55 2.55 2.55 2.55 2.55

Activation factor Select 0.4 for voice service and 1 for data service

Service demodulation threshold 6.6 7 7.8 9.2 8.8

IS95 voice Throughput of omni-directional BTS(Kbps)

78.5 70.6 56.9 38.7 43.3

Throughput of directional TRX (Kbps) 66.8 60.0 48.4 32.9 36.8

Service demodulation threshold 5.08 5.57 6.34 7.13 6.78

Throughput of omni-directional BTS(Kbps)

117.2 103.1 84.2 68.2 74.91X9.6K voice




138.5 113.0 88.1 65.4 78.01X19.2K data




145.7 128.4 105.9 74.2 87.41X38.4K data




131.5 118.7 99.5 65.1 82.71X76.8K data




118.8 102.1 84.8 53.4 79.91X153.6Kdata



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Reverse capacity under trial test condition


Simulation of Nanchang system test

System average load 70%

Soft blocking rate 2%

Interference factor 0.1

Power control variance (dB)

2.5

Activation factor 1

Eb/Nt average value of traffic channel 2.7

Sector factor 2.55

Throughput of traffic channel of

omni-directional cell (Kbps)

307

Throughput of traffic channel 1200 sector(Kbps)

261

Throughput of three-sector cell S111 BTS

(Kbps)

783


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Average reverse throughput of sector carrierThe capacity of the air interface of cdma-1X varies under

different access rates, but the basic capacity can be planned viacombining the traffic model and subscriber ratio

Md =K i R i

M= Md . P d + Mv . P vMv Throughput of voice service of carrier

Md Throughput of data service of carrier

Ki Ratio of different service access rate

Ri Different service access rates

Pd Data subscriber ratio

Pv Voice subscriber ratio

According to the traffic model and subscriber ratio ofAccording to the traffic model and subscriber ratio of ZhengzhouZhengzhou

Posts and Telecommunication Design Institute, it can be got thatPosts and Telecommunication Design Institute, it can be got that thethe

carrier capacity of the embedded omnicarrier capacity of the embedded omni--directional cell is 110kbps,directional cell is 110kbps,

and that of the embedded 120and that of the embedded 12000 sector is 94kbps.sector is 94kbps.



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Forward capacity model:

].)(

.10[

..)(

max

max

10/)(

max

pag

pag

p

sync

sync

pil

fTm

dBM

traftraf

traf

PGN

PGPKRLN

P

K

PGPM

+=

Forward capacity modelForward capacity model

l )( maxPM : Forward capcity

l maxP : Maximum allowance power of BTS

l :

Voice activation factor (it is generally 0.4)

l trafPG : Processing gain of traffic channel PG sync:Processing gain of synchronization channelPGpag: Processing gain of paging channel

l

l pN :Number of paging channel

l

l

l

l

l

traf: Demodulation threshold of traffic channel pil: Demodulation threshold of pilot channel

sync:Demodulation threshold of synchronization channel pag : Demodulation threshold of paging channel

Nm : Thermal noise

L T(R): Attenuation of forward link (corresponding to cell radius actually)

Ktraf: Subscriber distribution factor

Kf: Forward integrated interference factor (including internal cell and the external cell)

M (dB) : Demodulation threshold margin

l Conclusion for any embedded cell an be got via the formula: The parameter,which most greatly affectsthe forward capacity and which is most flexible, is the subscriber distribution parameterKtraf


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Analysis example of forward capacity of coverage areaSimulation result of certain trialWhen the cell radius is comparatively small (corresponding to less path loss: 130) and

the subscribers are distributing evenly within the cell, the forward capacity will be:

Analysis example of forward capacityAnalysis example of forward capacity

1024Throughput of three-sector cell S111BTS (Kbps)

341Throughput of traffic channel of 1200

sector (Kbps)

401Throughput of omni-directional site(Kbps)

7Demodulation threshold of trafficchannel (dB)

6Demodulation threshold of paging

channel (dB)

6Demodulation threshold ofsynchronization channel (dB)

-15Demodulation threshold of pilot channel(dB)

20Maximum transmission power (W)

0.4Subscriber geographical distributionindex

1.4System interference index

130Path loss (dB)

-105Background noise (dBm)


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p CDMA system has different capacities under difference networking

condition (cellular layout)

p The variance of total capacities of the equipment is not great under the same

environment and networking condition

p The moving speed affects the system capacity greatly Both of the main

components of reverse interference depend on the cell load. But in forward

interference, the multipath interference is the main component in the central

area, and the Ncell interference is the main component on the edge of the

cell

p The capacity of the forward link is finalized by the total transmission power

of cell and allocation of transmission power in the traffic channel and othersupplementary channels (the supplementary channels include pilot, paging

and synchronization channels, etc)

Analysis of soft capacity of CDMA 1X systemAnalysis of soft capacity of CDMA 1X system


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p If the power amplifier cannot provide enough forward power, then thesystem capacity will be forward limited. For example, improper cellular

distribution may result in most of the subscribers being located on the

edge of the cell, or severe cross-cell coverage, which in turn causes the

power of forward traffic channel and the soft handoff rate to be too great.

Further, the increase of soft handoff may increase the reverse capacity

but reduce the forward capacity.

pMaximum number of MSs supported by the forward link and reverse link

of CDMA system are different. Generally, the capacity of CDMA system is

finalized by the capacity of the reverse link. The reverse capacity and load

are used for design reference, while emulation is adopted for analysis of

forward capacity.

Analysis of soft capacity of CDMA 1X systemAnalysis of soft capacity of CDMA 1X system


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p In CDMA system, the coverage and the capacity can be inter-converted.p In the planning of data service, the asymmetry feature of the uplink/downlink

(Generally, the ratio between the uplink and the downlink is 1:4) of data service

should be fully utilized to design the cell coverage and capacity.

Analysis of forward/reverse balance of CDMA 1X

system

Analysis of forward/reverse balance of CDMA 1X

system

17.5620.6224.4928.37Countrysidereverseradius

7.2711.2313.5515.4917.2419.0620.9322.9925.2528.2932.3439.0145.19Countrysideforwardradius

1.011.181.41.61Downtownreverseradius

0.420.640.770.880.981.081.181.291.421.581.82.172.5Downtownforwardradius

128.8135.3138.1140.1141.7143.2144.6146147.4149.1151.1153.9156.1Forwardnet loss

460.8

kbps

422.4

kbps

384

kbps

345.6

kbps

307.2

kbps

268.8

kbps

230.4

kbps

192

kbps

153.6

kbps

115.2

kbps

76.8

kbps

38.4

kbps

19.2

kbps

Through

put


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QuestionQuestion

l Please state your understandings about the

soft capacity of CDMA system


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Principle of power planning:Power of pilot channel: 10-20% of total powerPower of paging channel: pilot -4.5dB (The rate of paging channel is

4800)Power of synchronization channel: pilot -10dBPower of traffic channel: remnant powerSetting principles of pilot power:

Establish proper cell scopeAllow channel estimation of receiverEnable the MS to add the cell to handoff active set

Guarantee the power amplification resources needed for the forwardtraffic channel within the coverage area.

The above settings are the static ones. But cell breath is a dynamic

allocation modification of pilot and power of traffic channel. Thepurpose is to adapt to the dynamic coverage and capacityvariance

Power PlanningPower Planning

Guarantee

correct access

and normal

conversation


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Objective of handoff planning:Objective of handoff planning:444 Reduce callReduce callReduce call---drop rate to ensure the requireddrop rate to ensure the requireddrop rate to ensure the required QoSQoSQoS444 Reduce interference to increase the networkReduce interference to increase the networkReduce interference to increase the network

capacitycapacitycapacity

444 Balance the distribution of traffic load of networkBalance the distribution of traffic load of networkBalance the distribution of traffic load of network

to reduce hot spot congestionto reduce hot spot congestionto reduce hot spot congestion

Key points of handoff planning:

Select the proper handoff location and avoid locating handoff zone

in the intensive traffic area

Plan the proper width of handoff area to ensure reasonable soft

handoff ratio

Select suitable handoff strategy for different networking

Finalize the suitable handoff parameter and the Ncell relationship

Objectives of handoff planning and key pointsObjectives of handoff planning and key points


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Review

r Objectives of handoff planning

r Key points of handoff planning


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Optimization


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.Reasonable forward and reverse coverage

(Plan the forward and reverse coverage of the

paging channel, access channel and traffic

channel, etc. reasonably)

.Achieve the maximum forward and reverse

voice capacity and data throughput

.Realize the least call-drop rate, blocking rate

and FER

.Accomplish excellent soft handoff, softer

handoff and hard handoff performance

.Reasonable forward and reverse coverage

(Plan the forward and reverse coverage of the

paging channel, access channel and traffic

channel, etc. reasonably)

.Achieve the maximum forward and reverse

voice capacity and data throughput

.Realize the least call-drop rate, blocking rate

and FER

.Accomplish excellent soft handoff, softer

handoff and hard handoff performance

System optimizationSystem optimization

Objectives of system optimization

Real i za t ion o f system per formance opt imizat ion v iaReal izat ion of system per formance opt imizat ion v ia

optim ization and m odification of system param etersoptim ization a nd m odification of system param eters


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Huawei Network Optimization Tools PacketHuawei Network Optimization Tools Packet

Electromagneticenvironment test

Network runningdatabase

33GToolGTool__PoolPoolTMTM

Drive test data

Handling suggestionfor networkadjustment

Interfaceinformation

Traffic statistics database

Geographicalanalysis

information

Planning database


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Pilot Pollution SolutionPilot Pollution Solution

4 Pilots with Ec/Io >

T_ADD

Question:

Cross-cell coverage or

missed-out Ncell relationship

may cause that the strong

signal pilot cannot be added to

the active set, which in turn

results in pilot pollution.

Solution:

Modify the main coverage

direction of the local cell

Modify the antenna and

power of Ncell to control the

coverage scope

Modify handoff parameter

Example 1

Example 2


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Have the best signal fallen into the search window

If the search window is too narrow, important pilot signal will be lost, resultingin interference If the search window is too wide, the search efficiency will be reduced, reducingthe conversation quality; There are three kinds of search windows for the MS, used for searching theactive set (including the candidate set), neighbor set and the remnant set. Thesetting strategies for the three kinds of windows are different. By judging themultipath effects and soft handoff branch via the Finger window of drive test

software, reference can be provided for optimization of the search window ofactive set.

Have the best signal fallen into the search window

If the search window is too narrow, important pilot signal will be lost, resultingin interference If the search window is too wide, the search efficiency will be reduced, reducingthe conversation quality; There are three kinds of search windows for the MS, used for searching theactive set (including the candidate set), neighbor set and the remnant set. Thesetting strategies for the three kinds of windows are different. By judging themultipath effects and soft handoff branch via the Finger window of drive testsoftware, reference can be provided for optimization of the search window ofactive set.

Cause!

Neighbor

List Search

Window

Too Narrow

Setting Strategy of MS Search WindowSetting Strategy of MS Search Window


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Parameter setting of search window For active set (including the candidate set), 5-7 (20-40 chips) is recommended for the

window. It is finalized by the delay spread of the propagation environment: It is 7ms for the

typical downtown, 2ms for suburban area. It is larger for the macro cell than for the micro cell.

For neighbor set, 7-13 (40-226 chips) is recommended. It is finalized by the delay spread of

the propagation environment and the distance of reference pilots of cell reaching to the MS.

7-13 is recommended for the reset set window during optimization, and 0 (4 chips) is

recommended after the optimization.

The time for each chip is 813.8ns and the propagation distance is 244.

Parameter setting of search window For active set (including the candidate set), 5-7 (20-40 chips) is recommended for thewindow. It is finalized by the delay spread of the propagation environment: It is 7ms for the

typical downtown, 2ms for suburban area. It is larger for the macro cell than for the micro cell.

For neighbor set, 7-13 (40-226 chips) is recommended. It is finalized by the delay spread ofthe propagation environment and the distance of reference pilots of cell reaching to the MS.

7-13 is recommended for the reset set window during optimization, and 0 (4 chips) is

recommended after the optimization.

The time for each chip is 813.8ns and the propagation distance is 244.

Setting Strategies of MS Search WindowSetting Strategies of MS Search Window


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According to the attribute that data service shrinks due to variance of rates, it is

required that high speed data service be provided to the subscribers located in the

center of the cell if possible, while rates of the data service of the subscribers located

on the edge of the cell should be limited.

According to the distribution of the local integrated service models, different

resource allocation strategies can be selected:

Those services, no matter the voice service or data service, which comes first,

will be firstly served. Voice or data wont be singly separated for allocation.

Reserve part of resource for voice service

This strategy can be adopted if the local voice service is the preferred one.Reverse part of resource for data service

This strategy can be adopted if the resource required for the local data is

comparatively fixed, and further, the preference of the service should be ensured.

According to the attribute that data service shrinks due to variance of rates, it is

required that high speed data service be provided to the subscribers located in the

center of the cell if possible, while rates of the data service of the subscribers located

on the edge of the cell should be limited.

According to the distribution of the local integrated service models, different

resource allocation strategies can be selected:

Those services, no matter the voice service or data service, which comes first,

will be firstly served. Voice or data wont be singly separated for allocation.

Reserve part of resource for voice service

This strategy can be adopted if the local voice service is the preferred one.

Reverse part of resource for data service

This strategy can be adopted if the resource required for the local data is

comparatively fixed, and further, the preference of the service should be ensured.

Capacity of Mixed Service And Coverage StrategyCapacity of Mixed Service And Coverage Strategy


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During RF optimization, group test (spectrum monitor, basic callDuring RF optimization, group test (spectrum monitor, basic call test, freetest, free--load pilotload pilot

test and loaded coverage test) should be firstly performed, andtest and loaded coverage test) should be firstly performed, and then comes thethen comes the

optimization of loaded mobile test within the system scope.optimization of loaded mobile test within the system scope.

Many basic objectives of optimization of both of data serviceMany basic objectives of optimization of both of data service and voice service are theand voice service are the

same.same.

The optimization of voice service should be guaranteed before thThe optimization of voice service should be guaranteed before the data service is pute data service is put

into large business use. And fine tuning of data service is requinto large business use. And fine tuning of data service is required after businessired after business

application.application.

Balance of the performance of both voice service and data servicBalance of the performance of both voice service and data service should be ensured.e should be ensured.

Optimization Strategy of CDMA Radio NetworkOptimization Strategy of CDMA Radio Network


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p Main optimization parameters: Optimization of RF environment

The optimization is the elementary one of the radio cellular layout.Whether

the cellular layout is successful or not finalizes 85% radio network quality,

and this is especially true for the CDMA radio network.

Total transmission power of each sector

Antenna configuration (azimuth, downtilt, height, graphics mode)

List of neighbor pilots and the priority sequence

Size of search window of neighbor set

Ratio of soft handoff and hard handoff, and thresholds

o Secondary optimization parameters: Fine tuning of partial performance

Size of search window of active set of MS

Size of search window of BTS

Setting of digital gain of each (sub) channel, that is, power allocation

Other algorithm parameters

Optimization strategy of CDMA radio networkOptimization strategy of CDMA radio network


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Coverage Forward/reverse voice capacity

Call-loss rate

Access (call attempt or being called) failure

rate

Congestion rate of voice call

Call quality FER (1%)

Failure rate of soft handoff

Pilot Ec/Io (-15dB)

Integrated percent of multi-channel soft

handoff (1.5-2 or 35-40%)

transmission power of MS

transmission power of BTS traffic channel

Main measurement parameters of CDMA 1X

network (voice service)

Main measurement parameters of CDMA 1X

network (voice service)


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Coverage

Average throughput

Delay

Data rate

RLP retransmission rate

FER5% FER of basic channel of forward link

FER of supplementary channel of forward link

FER of basic channel of reverse link

Pilot Ec/Io (above -15dB)

Integrated percent of multi-channel softhandoff (1.5-2 or 35-40%)

transmission power of MS

transmission power of traffic channel of BTS

Main measurement parameters of CDMA 1X network

(data service)

Main measurement parameters of CDMA 1X network

(data service)


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Evaluation of IS-95 network of certain downtownEvaluation of IS-95 network of certain downtown

Basic condition of networkScale of IS95 network of certain downtown:Table 1: Scale of IS95 network of certain downtown

In the existing IS-95 network, except two BTSs in thedowntown (not have been activated), all of the rest nineBTSs share addresses with the GSM network. The minimuminter-BTS distance is about 500 meters, and the maximum isabout 3,000 meters. Except a certain BTS, S1/1/1

configuration is uniformly adopted for the rest BTSs, with 283frequency adopted.

11CBTS

QTYEquipment name


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Distribution of Ec/IoDistribution of Ec/Io


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Distribution of Forward FERDistribution of Forward FER


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RX DistributionRX Distribution


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Handoff BranchHandoff Branch


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Result of case analysisResult of case analysis

Through simple analysis of the indices, it can be concluded thatthe quality of the IS-95 network of the city zone is ecumenical.

Specific problems are as follows:1The sites located in central areas in the downtown are so closeto each other that the design of downtilt and azimuth isunreasonable, and configuration of pilot power may be

unreasonable as well, thus cross-cell may happen in certainsectors, which in turn causes that the Ec/Io in some areas iscomparatively low. In the cell where there are crowded withbuildings, the above case will be worsened due to (building)penetration loss. As a result, the above data parameters cannotsatisfy the requirements of future development of data service in

most of the areas.2This low Ec/Io may directly cause high BER of the whole net.3Received power of MS in some important sections of the cityzone may be comparatively low.4Because the high BTS density in the city zone may cause highratio of soft handoff, system resources is wasted, and pilotpollution is brought as well.


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Suggestions For Tilt AdjustmentSuggestions For Tilt Adjustment

3330025201Lv You Xue Yuan -

3

3317025201Lv You Xue Yuan -2

635025201S1/1/1

Lv You Xue Yuan-1

8624033201Yan Chang-3

10612033201Yan Chang-2

108033201S1/1/1

Yan Chang-1

10334025201Jun Fen Qu-3

10624025201Jun Fen Qu-2

10310525201S1/1/1

Jun Fen Qu-1

6324023201Cehnzhou Er Jian-3

8310023201Cehnzhou Er Jian -2

63023201S1/1/1

Cehnzhou Er Jian -1

Modifieddowntilt

Originaldowntilt ()

Azimuth ()Antenna(meter)

ChannelSitetype

Chinese names ofBTS

Downtilt()Azimuth()Height (m)Channel


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Review

r Optimization objectives of CDMA 1X network

r Optimization strategies of CDMA 1X network

r Main measurement parameters of CDMA 1X network


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Date post:	08-Apr-2018
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