1 UMTS Radio Network Planning Process-65.ppt

UMTS Radio Network Planning Process

ZTE University

Content

UMTS Technical Features UMTS Network Planning Process

Propagation of Electromagnetic wave － straight, reflection, scattering, diffraction

Radio signal fading includes 3 parts: Path loss: fading with distance between transmitter and receiver Large scale fading ： middle amplitude of fading with log normal

distribution, slow fading, caused by shadow effect Small scale fading: small amplitude of fading with rapid change,

fast fading, caused by multi-path effect.

Radio Propagation Feature

= +

+

Pathloss

Slow fading

Fast fading

distance

Signal Rx Level

Multi-Address Technology

FDMA Different channels at different

frequencies, such as AMPS and TACS.

TDMA Different channels at the same

frequency are distinguished by timeslots, such as GSM.

CDMA Different channels at the same time

and frequency are distinguished by different codes, such as UMTS.

Self-Interfering System

Source Shared frequency spectrum caused

intra-frequency interference, multi-Path effect, difficult to implement perfect orthogonality with ideal self correlation and cross correlation.

Phenomenon Noise rise, soft capacity

Solution Power control, admission control, load

control and careful network planning

One of radio network planning goals is to minimize self-interfering

Power Escalation

Uplink noise rise increases with the number of subscribers non-linearly

Downlink Node B power increases with the number of subscribers non-linearly

Soft Capacity

Soft Capacity

InterferenceInterference

Cell Breathing

Power Control

The signal for one subscriber is the noise to the others. The transmitted power should be controlled in order that it would not block other subscribers.

Near - far effect

Node B

Node B

despreading

despreading

Soft Handover

Soft handover UE connects with more than

one radio links with different Node B

Softer handover UE connects with more than

one radio links with the cells in the same Node B

Hard handover Intra-frequency hard

handover Inter-frequency hard

handover Inter-RAT hard handover

RL1

RL2

Coverage and Capacity Relationship

135

140

145

150

155

160

100 200 300 400 500 600 700 800 900 1000 1100 1200 1300

throughput per sector [kbps]

Max.

allow

ed

path

lo

ss [

dB

]

downlink loaddownlink load

uplink load

uplink load

Normally,Coverage is UL limitedCapacity is DL limited

Demodulation threshold Eb/No

Eb indicates the signal energy per bit, Eb = S/R where S indicates signal energy and R indicates service bit rate.

No indicates the noise spectrum density, No = N/W where W indicates chip rate (3.84 M) and N indicates noise.

Eb/NoEb/No

Subscriber 1Subscriber 1NoiseNoise Subscriber 2Subscriber 2

Subscriber 3Subscriber 3

Processing Processing Gain(PG)Gain(PG)

PGN

S

R

W

N

S

N

W

R

S

N

E

o

b

Multi-Service Hybrid System

Different services have

different rates, and their

coverage ranges and

capacities are different.

Different services have

different rates, and their

coverage ranges and

capacities are different.

Different proportions and

composition of hybrid service, with

different system capacities

Different proportions and

composition of hybrid service, with

different system capacities

64kbps service coverage



Network Planning Goals

Fulfill operators’ requirement on coverage, capacity, and service quality, estimate network scale, minimize investment, and simulate to verify.

Predict network development trend, and prepare for future development.

We should do…We should do…

Maximize coverage in time and space.

Minimized intra-system interference to reach the required service quality.

Optimize radio parameters to maximize service quality.

With capacity and service quality fulfilled, minimize equipment number and cost.

GoalsGoals

Network Planning Policy

The purpose of radio network planning is to shorten the investment return period than lower the CAPEX as well as OPEX.

Firstly for coverage, the solution is:

point coverage

line coverage

plane coverage

Content

UMTS Technical Features UMTS Network Planning Process

Planning Process - Requirement AnalysisRequirement AnalysisRequirement Analysis

Sites Sites SurveySurvey

Network DimensioningNetwork Dimensioning

Pre-Planning Pre-Planning SimulationSimulation

Network Network SimulationSimulation

Propagation Model Propagation Model Test and CalibrationTest and Calibration

Output PlanningOutput Planning ReportReport

Sites LayoutSites Layout

Requirement Analysis

Learn the customer’s requirement of coverage, capacity, and QoS.

Learn the landform and environments of the planned area.

Learn the population distribution and average income per person in the planned area.

Learn information about the existing network in the planned area.

The purpose to sort the planning area is to refine network design and layout. Different areas have different geographical environment, vegetation distribution, and building density. Different areas require different number of Node B to meet the coverage requirement.

Planning Area SortingPlanning Area Sorting

Requirement Analysis (Cont.)

Area type Area characters

Dense Urban Central business district, dense shopping center, dense residential area

Mean Urban Industrial park, shopping center, residential area

Suburban The edge of city, the center of village and town

Rural Farm, the edge of village and town

Different areas have the different requirements for the service type coverage rate. Different requirements for service type and coverage rate in the same area will get different number of Node B

Coverage Requirements Coverage Requirements 64 k CS

144k PS data

384k PS data


No. of subscribers and their ‘profile’, traffic model,

service type , forecast, “hot spots”

Capacity Requirements Capacity Requirements


0

2

4

6

8

10

12

0 10% 20% 30% 40% 50% 60% 70% 80% 90%

Load

Noi

se R

ise

Stable system

Just stable system

Uns

tabl

e sy

stem

Load increases, Coverage reduces , System unstable

Cell loadCell load


The important building in the planning areaThe information of traffic line, just as highway The important villages and towns in the planning area

Other information Other information


Planning Process – Propagation ModelRequirement AnalysisRequirement Analysis








Free Space Propagation Loss

22

2

)4()(

d

GGPdP rtt

r

Pt: TX power

Pr(d): Rx power

Gt: Gain of TX antenna

Gr: Gain of RX antenna

d: Distance between TX and RX antennas

PL: Pathloss in free space

22

2

)4(log10log10)(

dP

PdBPL

r

t

d

Loss4

lg20

fdFreeLoss lg20lg2044.32

Free Space Propagation Loss

d

Radio Propagation Model

Factors in radio propagation model: In the space propagation, many factors enter into radio wave loss,

including ground absorption, reflection, refraction and diffraction, while these factors are inapplicable for the propagation loss formula in free space;

While planning and constructing a mobile communication network, you have to make detailed study about electric wave propagation features and field strength prediction before determining frequency band, frequency allocation and radio wave coverage, calculating communication probability and inter-system electromagnetic interference, and finally defining radio equipment parameters;

The radio propagation model presents the designer an approximate propagation effect in the practical propagation environment to estimate the space propagation loss. Therefore, the propagation model veracity determines whether the cell planning is reasonable.


The propagation environment plays an important role in setting up a radio propagation model. The propagation environment in a special region consists of the following factors:

Terrains (mountains, hills, plain or water area) Number, height, distribution and material features of buildings Vegetation features Weather conditions Natural or man-made electromagnetic noise Working frequency of system Movement of mobile station

Model Name Frequency Range

Okumura-Hata 150 MHz–1500 MHz macro cell

Cost231-Hata 150 MHz–2000 MHz macro cell

Cost231 Walfish-Ikegami 800 MHz–2000 MHz micro cell

Keenan-Motley 900 MHz and 1800 MHz indoor environment

General model 150 MHz–2000 MHz macro cell


Improvement to the space free loss formula:

mmbb CAhdhhfPathloss lglg55.69.44log82.13lg9.333.46

f -refers to carrier, unit: MHz, applicable for 150 MHz–2000 MHz

bh -refers to BS antenna height, unit: m, effective height 30 m–200 m

d -refers to the distance from mobile station to antenna, unit: Km

mAh -refers to mobile station antenna height correction factor

mC -refers to city center correction factor, 3 dBm for large cities and 0 dBm for middle- and small-size cities

Cost231-Hata Model

General Model

K1-Fading Constant K2-Distance Fading Coefficient K3 、 K4-Mobile Station Antenna Height calibration

Coefficient K5 、 K6-Base Station Antenna Height calibration

Coefficient K7-Diffraction calibration Coefficient Clutterloss-Calibration Value of Physiognomy Fading D-Distance between base station and mobile station (km) Hms -Mobile Station Antenna Effective Height (m) Heff-Base Station Antenna Effective Height (m)

sClutterlosnlossdiffractioK

dHeffKHeffK

HmsKHmsKdKKPathLoss

)(7

)log()log(6)log(5

)log(43)log(21

Propagation Model Selection Propagation Model Selection

Propagation Model Test

Test sites should be selected from each environment categories.

To cover enough clutters.

The testing site shall be free of visible obstructions around.

The testing site shall be higher than the surrounding buildings.

Site SelectionSite Selection

Transmitter

Antenna

Receiver

Laptop

Propagation Model Test (Cont.)

All directions from the testing site should be included.

The vehicle should take a route to or from the testing site in the shape of “8”, net, ring, or spiral, with a constant speed.

Route SelectionRoute Selection

Propagation Model Calibration (Cont.)

Distance Filtration.

Intensity Filtration.

Land Feature Filtration

Data ProcessData Process

Propagation Model Calibration (Cont.)

K1-Fading Constant K2-Distance Fading Coefficient K3 、 K4-Mobile Station Antenna Height calibration

Coefficient K5 、 K6-Base Station Antenna Height calibration

Coefficient K7-Diffraction calibration Coefficient Clutterloss-Calibration Value of Physiognomy Fading D-Distance between base station and mobile station

(km) Hms -Mobile Station Antenna Effective Height (m) Heff-Base Station Antenna Effective Height (m)

sClutterlosnlossdiffractioK

dHeffKHeffK

HmsKHmsKdKKPathLoss

)(7

)log()log(6)log(5

)log(43)log(21

Propagation Model Selection Propagation Model Selection

Planning Process – Network DimensioningRequirement AnalysisRequirement Analysis








Network Dimensioning

Link budget Capacity analysis Give need analysis report, and estimate the Number

of NodeBs in the planned area.

Network Dimensioning (Cont.)

Link Budget

Coverage Target Mas Allowable Path Loss

Raius

Propagation Model

Link budget

No.Node B

PAPA

Feeder lossFeeder loss

PathPath Loss Loss

Antenna GainAntenna Gain

Penetration LossPenetration Loss

Receiver SensitivityReceiver Sensitivity

Margin Margin

Body LossBody Loss

UE PowerUE Power

BS PowerBS Power

Capacity Analysis

Ampl i tudeEqui val ent voi ce channel s

provi ded by each cel l

I nter meanI nter vari anceCapaci ty factor

Vi rtual channel of eachcel l

Syetem Total _vi rtual _El r Cel l _vi rtual _El r

No. Cel l

ErlvirtualCell

ErlvirtualTotal

__

__

Planning Process – Pre-Planning SimulationRequirement AnalysisRequirement Analysis








Pre-Planning Simulation

Verify estimation with simulation

Give suggestions for Node B layout, location, and

area.

Guide site survey work

Existing site’s sourcesExisting site’s sources

PropagationPropagation modelmodel

Traffic modelTraffic model

Planning Process – Sites SurveyRequirement AnalysisRequirement Analysis








Sites Survey

To get the necessary data needed by network

planning and simulation

To learn geographical environment and radio

environment of the site

To learn the condition of building site

To learn the traffic distribution of planning area

To provide the candidate sites for planning area

Site Survey

Convenience in traffic, reliability in city power supply, lightning protection and

grounding, small floor space;

Network construction initial stage, ensure the coverage and quality of VIP

subscribers and the area with high user density ;

Under the condition of no effects to the site layout, should choose the currently

existed sites as the candidate sites and utilize their equipment room, power

supply, tower, etc. ;

Avoid the site location which is close to radar, if necessary, for the security

factors, should apply the correspond methods to avoid the mutually interference ;

Avoid to locate the site on the mountain, in the forest ;

Avoid to select the sites which will be affected by the potential constructed

buildings .

Site Selection PrinciplesSite Selection Principles

Site Survey

Site information: site name, site address, latitude, longitude, building height, tower height Radio Parameter: azimuth angle, down-tilt, antenna height antenna type, diversity type and separation Radio environment description Interfering source

Data RecordingData Recording

Planning Process – Network SimulationRequirement AnalysisRequirement Analysis








Network Simulation

Input several optional solutions simultaneously.

Simulate all optional solutions. Select the most appropriate solution

according to the simulation result.

Simulation results － graphic output

Best server Pilot strength Pilot Ec/Io Soft handover probability Pilot pollution Service coverage probability Cell load

Best server

Best server

Over shoot

Over shoot erased

Pilot strength-CPICH RSCP

Pilot strength

No continuous coverage of pilot

Continuous coverage of pilot

Pilot Ec/Io

Pilot quality improved

Pilot quality not good

Soft handover probability

Pilot pollution-The number of pilot polluters

Service coverage probability

Coverage probability improved

Coverage probability not good

Cell load-Uplink Load

Statistics reportSimulation Statistics AnalysisSimulation Statistics Analysis

Statistics report (Cont.)

Mean Attempted 992.850Mean Served 964.050 97.10%Mean Failed 28.800 2.90%Mean In Soft or Softer Handover 271.250 28.14%Mean In Softer Handover 66.400 6.89%

Contributions to FailureNo UL Channels Primary Channel 0.00%No DL Channels Primary Channel 0.00%UL Channels Channel Limit Reached 0.00%DL Channels Channel Limit Reached 0.00%Low Pilot SIR 3.65%Downlink Eb/No (Range) 1.74%Downlink Eb/No (Capacity) 0.00%Uplink Eb/No 15.63%Noise Rise 86.63%No Carrier 0.00%Excessive Pathloss 0.00%

Comparison between simulation and drive test data Comparison between simulated and tested

network performance Calculate the difference of

simulated and tested Ec and Ec/Io in each bin

Statistics on thousands of samples

Made comparison for 3 trial UMTS networks in China: Beijing, Shanghai, Guangzhou

Comparison between simulation and drive test data

Comparison between simulation and drive test data

Comparison shows that the planned network can predict the performance of real network quite well

Planning Process – Output Planning Report

Requirement AnalysisRequirement Analysis








Planning Report Output

Report contents Networking requirements for the UMTS network Service model and demand analysis Radio network scale estimation Policy and principle analysis Networking proposal and solution to network construction by

stages

Attachment contents Propagation model test result BS address survey table BS engineering parameter table Radio parameter configuration table Network diagram and site layout diagram simulation result report

1 UMTS Radio Network Planning Process-65.ppt

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Transcript of 1 UMTS Radio Network Planning Process-65.ppt