3G Network Planning Study with Monte- Carlo...

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3G Network Planning Study with Monte-CarloSimulation

3G Network PlanningStudy with Monte-Carlo Simulation

Nuno Daniel Cardoso

Portugal Telecom Inovação S.A.

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Overviewn Objectives.n Simulation scenario description.n Load impact on coverage probability.n Noise rise limit.n Handover margin.n BS Antenna tilt angle.n BS Antenna height.n Downlink handover gain.n Pilot power.n BS sector aperture.n Voice vs. video impact.

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Objectives of the Performed Workn Study UMTS cellular planning via Monte-

Carlo simulation using real terraindatabase information.

n Understand the impact of some WCDMAparameters in the system performance.

n Evaluate the effects of using differentservices in the same cell.

n Gain experience in this new technology tobetter predict and understand the systembehavior during the deployment phase.

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Terrain Morphology and Cells Layout

Jersey Island – irregular terrain leads to dissimilarcell sizes.

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Parameters Assessed by Simulation

Parameter Default Other values

Noise rise limit (dB) - limit of the noise rise allowed in the system

6 3 None

Handover margin (dB) - margin related to the highest signal strength

6 3 9

BS antenna tilt (º) - angle of the antenna down tilting

0 3 6

BS antenna height (m) - height of the antenna from the ground

25 10 40

Downlink soft handover gain (dB) - soft handover gain in the downlink

2 -2 0

Pilot power (dBm) - power of the pilot channel

30 27 33

BS antenna aperture (º) - angle of the half power beam width

85 60

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Input Simulation Parameters

Other simulation parameters needed for thesimulator.

Parameter Value

Maximum BS Tx power (dBm) 43

Maximum Tx power per connection (dBm) 35

Common channels power (dBm) 30

Simulation geographical resolution (m) 50

Terminal background noise (dBm) -99

BS background noise (dBm) -103

Active set size 3

Orthogonality factor 0,7

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Services characteristics

Service/Terminal Voice/ Handheld

144 kbps/PDA video

Type of service Circuit switched

Circuit switched

Bit rate (kbps) 12 144

Mobile speed (km/h) 120 120

Downlink Eb/No required (dB) 7.9 4.5

Uplink Eb/No required (dB) 6.1 3.1

Downlink activity factor 0.5 1

Uplink activity factor 0.5 1

Maximum mobile power (dBm) 21 24

Mobile dynamic range (dB) 65 70

Power control step size (dB) 1 1

Required Ec/Io (dB) -21 -14

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Load Impact on Coverage Probability(I)

Noise rise limit = 6 dBNoise rise limit = 6 dB

Handover margin = 6 dBHandover margin = 6 dB

BS antenna tilt = 0ºBS antenna tilt = 0º

BS antenna height = 25 mBS antenna height = 25 m

DL soft handover gain = 2DL soft handover gain = 2dBdB

Pilot power = 30Pilot power = 30 dBm dBm

BS antenna aperture = 85ºBS antenna aperture = 85º

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Load Impact on Coverage Probability(II)n Load impacts on the coverage area (cell

“breathing” effect).n Increasing the traffic density deteriorates

the QoS.n Cell load depends of the cell captured

traffic (uniformly distributed).n Large cells experience worse coverage

probability (they serve more traffic).

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Noise Rise Limit Variation (I)

Uplink transmittedpower







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Noise Rise Limit Variation (II)

n Increasing the noise rise limit increasesthe maximum allowed interference in thecell.

n More interference allowed means morecapacity, but on the other hand it alsomeans less system stability.

n The consideration of no noise rise limitleads to the exclusion of terminals due touplink and/or downlink low level of Eb/No.

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Handover Margin Variation (I)

Soft Handover Probability Noise rise limit = 6 dBNoise rise limit = 6 dB






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Handover Margin Variation (II)

n The handover margin has a direct impacton the number of terminals in soft/softerhandover.

n Larger handover regions result in lessaverage transmission power.

n Downlink soft/softer handoverconsequences:l Increases the number of connections.l Leads to a potential increase in the

interference (depending on the radio channelstatus and diversity gain).

l Leaves less power available to other channels.

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BS Antenna Tilt Angle Variation (I)

Pilot Ec/Io Noise rise limit = 6 dBNoise rise limit = 6 dB






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BS Antenna Tilt Angle Variation (II)

n The antenna tilting angle affects the signalpath loss.

n Increasing the down tilting angledecreases the interference area. It alsoleads to an average decrease on the Eclevel, resulting in an overall decrease ofEc/Io.

n The uplink transmitted power increases inaverage with the increase of the tilt angle.

n The softer handover region increases andthe soft handover region decreases.

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BS Antenna Height Variation (I)

Uplink transmittedpower







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BS Antenna Height Variation (II)

n Similar effects as experienced for the tiltangle variations.

n The impact is more dependent on theterrain profile.

n Lower antenna heights lead to largersofter handover regions.

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Downlink Handover Gain Variation (I)

Downlink Eb/No failureprobability




BS antenna height = 25BS antenna height = 25mm


BS antenna aperture =BS antenna aperture =85º85º

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Downlink Handover Gain Variation(II)n Directly affects the downlink performance.n Higher gains allow less downlink average

transmission power, leading to moreavailable resources to other channels.

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Pilot Power Variation (I)

Pilot Ec/Io Noise rise limit = 6 dBNoise rise limit = 6 dB






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Pilot Power Variation (II)

n The pilot power level sets cell coveragearea.

n It affects directly the Ec/Io level.n If more power is allocated to this channel

less power is available for traffic channels.n Higher pilot powers result in higher

interference levels.

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BS Sector Aperture Variation (I)

Softer Handover Probability Noise rise limit = 6 dBNoise rise limit = 6 dB






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BS Sector Aperture Variation (II)

n The radiation pattern depends on theantenna type and characteristics.

n A wider sector aperture allows largersofter handover regions.

n Larger apertures increase the interferencelevel.

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Voice vs Video Service (I)

Uplink Transmitted Power

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Voice vs Video service (II)

Pilot Ec/Io

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Conclusions (I)

n Coverage quality depends of trafficdensity.

n Higher noise rise limit allows morecapacity but also more interference.

n Increasing the handover margin reducesthe transmission power but increasesdownlink resources utilization and theinterference.

n The antenna tilting and height define Ec/Iolevel and the interference captured.

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Conclusions (II)

n The cell size is defined by the pilot powerthat also causes interference.

n The downlink handover gain mirrors theadvantages of soft/softer handover.

n The antenna sector aperture sets thecaptured interference and softer handoverarea.

n For the same cell total throughput, thevideo service produces less interferencethan voice but the terminals transmittedpower is considerably higher.

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Thank you for yourattention!

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