Asset Planning Trainning

7/31/2019 Asset Planning Trainning

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Welcome to all of youWelcome to all of you

to world of TELECOM "byto world of TELECOM "by


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Welcome to all of youWelcome to all of you

to world of TELECOM "byto world of TELECOM "by

Detailed Tropic discussed in this chapter

CW Testing

Model Tuning

Antenna

1. Isotropic Antenna

2. Dipole Antenna

RF Planning

1. Coverage planning

2. Capacity planning

3. Highway Planning 4. City planning

Planning Tool

Asset Planning Tool


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Decorum of the course to be maintained by: Keeping your mobiles in Switched-off or Silentmode. Doing one discussion at a time. Following the timings strictly as per schedule forBreaks. Making the course interactive by asking questions

and by giving suggestions.

Please introduce yourself as per guidelinesbelow:

Name Qualification Professional Experience in years/months (if

applicable) Name of the previous company (if applicable)

Tenure in previous company (if applicable) Name of the Institute/University Year of passing What is your AIM in life Expectations from this company Expectations from this course


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Designing a cellular system - particularly one that incorporates both Macro

cellular and Microcellular networks is a delicate balancing exercise.

The goal is to achieve optimum use of resources and maximum revenuepotential whilst maintaining a high level of system quality.

Full consideration must also be given to cost and spectrum allocationlimitations.

INTRODUCTION TO RFPLANNING


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INTRODUCTION TO RF PLANNING

A properly planned system shouldallow capacity to be addedeconomically when traffic demandincreases.

As every urban environment isdifferent, so is every macro celland micro cell network. Henceaccurate planning is essential inorder to ensure that the system

will provide both the increasedcapacity and the improvement innetwork quality where required,especially when deployingMicrocellular systems.


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RF planning plays a critical role in the Cellular design process.

By doing a proper RF Planning by keeping the future growth plan in mind wecan reduce a lot of problems that we may encounter in the future and alsoreduce substantially the cost of optimization.

On the other hand a poorly planned network not only leads to many Networkproblems but it also increases the optimization costs and still may not ensurethe desired quality.

INTRODUCTION TO RFPLANNING


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The high level life cycle of the RF network planning process can be

summarised as follows :-

To help the operatorto identify their RFdesign requirement

Optional

Discuss and agree RFdesign parameters,assumptions andobjectives with thecustomer

Coverage requirement Traffic requirement Various level of design(ROM to detail RFdesign)

Issuing of search ring Cand. assessment Site survey, design,approval

Drive test (optional)

Frequency plan Neighbour list

RF OMC data Optimisation

ComparativeAnalysis

RF Designrequirement

RF Design

SiteRealization

RF Design

Implementation



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This is an optional step

This is intended to :-

Help an existing operator in building/expanding their network

Help a new operator in identifying their RF network requirement,e.g. where their network should be built

For the comparative analysis, we would need to :-

Identify all network that are competitors to the customer

Design drive routes that take in the high density traffic areas ofinterest

Include areas where the customer has no or poor service andthe competitors have service


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The result of the analysis should include :-

For an existing operator

All problems encountered in the customers network

All areas where the customer has no service and a competitordoes

Recommendations for solving any coverage and qualityproblems

For a new operator Strengths and weaknesses in the competitors network

Problem encountered in the competitors network


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The RF design inputs can be divided into :-

Coverage requirements

Target coverage areas

Service types for the target coverage areas. These should be

marked geographically Coverage area probability

Penetration Loss of buildings and in-cars

Capacity requirements

Erlang per subscriber during the busy hour

Quality of service for the air interface, in terms GoS

Network capacity

Growth plan - Coverage and Capacity


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Available spectrum and frequency usage restriction, if any

List of available, existing and/or friendly sites that should beincluded in the RF design

Limitation of the quantity of sites and radios, if any

Quality of Network (C/I values)

Related network features (FH, DTX, etc.)


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RF Network Design There are 2 parts to the RF network design to meet the :-

Capacity requirement

Coverage requirement

For the RF Coverage Design

RFCoverage

Design

Link

BudgetPropagation

Model

DigitizedDatabasesCW Drive

Testing

Customer

Requirements



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Network Planning Tool

CW Propagation Tool

TOOLS USED FOR RFPLANNING


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DRIVE TEST FOR C.W.

TESTING


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Predesign drive test for measurement integration

This is at beginning of design when no site has been built or even selected.All test sites are temporary.

Predesign drive test Post design drive test

Drive test types

INTRODUCTIONDRIVE TEST FOR C.W. TESTING


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DRIVE TEST FOR C.W. TESTING

Drive test is performed mostly for characterization of propagationand fading effects in the channel. The object is to collect field datato optimize and adjust the prediction model for preliminarysimulations.

Post design drive test for site verification / optimization

Drive test is performed to verify if they meet the coverageobjectives.

Overlaps are checked for hand-offs.


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INTRODUCTION

In field measurement we have to collect variations due to propagation andslow fading.

The received signals are typically sampled and averaged over spatialwindows called bins.

There are several sampling issues to be considered like

Sampling rate

Averaging window

Number of bins to be measured



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SAMPLING CRITEREA

When measuring the RF signal strength certain sampling criteria must be metto eliminate the short-term fading components from the long-term component( I.e. log normal fading )

The RF signal strength measurements must be taken over a radio path ormobile path distance interval of 40, where is the wavelength of the RF signal.

If the distance interval is too short, the short term variation cannot be smoothedout and will affect the local mean.



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If the distance interval is too long, the averaged output cannotrepresent the local mean since it washes out the detailed signalchanges due to the terrain variations.

The number of RF measurements taken within the 40 distanceshould be greater than 50.

Depending on the speed of the vehicle during the drive test, thesampling interval in time is selected.

Measurements have to be stopped whenever the vehicle is notmoving.


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SAMPLING CRITEREA If f = 1900MHZ, then

= 3 * 108 / 1900 * 106

=0.158 m

40 = 40 * 0.158

= 6.32 m

50 measurements must be recorded every 6.32m or 1 measurement every0.1264m

The conversion from sampling distance to mobile velocity can be done asfollows

minimum sampling rate ( per second ) = v / (0.1264 m/sample)

If velocity of vehicle is 50 kph then

Sampling rate( per second ) = (50000/ 3600) / 0.1264

= 110 samples / sec

TEMS kit cannot be used for this purpose as it can report RF signal strengthmeasurements at a maximum rate of 1 sample per second



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WINDOW SIZE In field measurements the interest is on local averages of received signals.

The size of averaging window have to be small enough to capture slowvariations due to shadowing and large enough to average out the fastvariations due to multipath.

A typical range is 20 to 1500 m.

The bin size is typically selected in 40 to 1500m, i.e. all measurements in thissize square are averaged to one value.

Normally the post processing tool takes care of averaging the collected dataover different bins.



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NUMBER OF

BINS

The predicted and measured signal strengths for all bins within the drive routeis compared and the best set of correction factors to minimize the predictionerrors is determined.

All the bins within the coverage area cannot be drive tested. So a large enough

sample set should be considered. The more the number of bins, the larger the confidence level of results.

Generally for acceptable confidence at least 300 to 400 bins have to beconsidered.

Bin



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PROPAGATION KITThe propagation test kit consists of

Test transmitter.

Antenna ( generally Omni ).

Receiver to scan the RSS (Received signal levels). The receiver scanningrate should be settable so that it satisfies Lees law.

A laptop to collect data. A GPS to get latitude and longitude.

Cables and accessories.

Wattmeter to check VSWR.

TransmitterRECEIVER LAPTOP

GPS Antenna

Receiver Antenna

Transmit Antenna

DRIVE TEST FOR C.W.TESTING


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The propagation test kit consists of



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TRANSMITTER SETUP

If the propagation test is being done for model tuning to produce a genericmodel for macro cells, then a high point in the particular area has to beselected.

The transmitter and the transmit antenna will be placed at this point (say the

roof of the building ). The transmit antenna is connected to the transmitter via a RF cable.

Check to see that the cable is connected properly and tight.

Loosely connected or faulty cable can increase the VSWR.

A test frequency has to selected from the frequency band allocated to theoperator. Set the transmitter to this test frequency.

TEST

TRANSMITTER



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TEST SITE SELECTION

Site selection is based on a number of criteria. It may not be possible to satisfyall these criteria at the same time, but it is important to select the best sitesavailable.

Drive test sites should be selected to give a good representative sample of the

system coverage area. The exact number of sites required will depend on thesize of the system coverage area and the variability of the characteristics of thecoverage area.


DRIVE TEST FOR C W TESTING


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All terrain and clutter types in the area should be represented in thedrive test data for proper prediction tuning.

Typical terrain types are: Flat, Rolling Hills, Large Hills,

Mountains

Typical clutter types are: Water, Open Land, Forest,Commercial / Industrial, Low Density Urban, Medium DensityUrban, High Density Urban, City Center, Airport.

City maps, topographical maps and aerial photographs can beuseful in determining the terrain and clutter types for an area. Itmay also be necessary to drive the area and observe building typesand density.


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TEST SITE SELECTION

Site Availability

Test sites must be available for use during the drive test.

The site owner/supervisor should approve access to the site for as long asneeded to complete the testing. This may involve multiple visits to the site,possibly on short notice.

Test sites must also be physically accessible to allow setup of the transmitterequipment and mounting of the antenna. For this reason building top sites arepreferred to tower sites.



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Site Visit

Each site selected should be visited before testing to verify that issuitable for use.

The inspection should be done by the same people who will bedoing the site setup for the actual drive test. Familiarity with thesite should speed up the site setup during the drive test.



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BUILDING SITE SELECTIONBUILDING SITE SELECTION

When inspecting a building site the rooftop should be checked for anyobstructions that would interfere with signal propagation. This could includeobjects on the rooftop itself or other nearby buildings or structures.

The antenna location should be selected and a sketch of the rooftop made toidentify this location relative to other objects nearby.

Photographs should be taken of the location where the antenna will be mountedand in all directions looking away from the site.



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BUILDING SITE SELECTION



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TOWER SITE SELECTION

When inspecting a tower site the best location to mount the antenna to the

tower must be deter-mined. This should be selected such that the tower doesnt interfere with the

propagation pattern of the transmit antenna. This will usually require that theantenna be above the tower or on an arm extending from the side of the tower.

The area around the tower should be checked for any obstructions that wouldinterfere with signal propagation.



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TEMPORARY STRUCTURE

Generally cranes are used for temporary structure.

When cranes are used power generators have to be arranged in

advance. The location should be selected such that the antenna will be above

any nearby obstacles.



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TEMPORARY STRUCTURE



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DRIVE TEST PLAN

Each drive route should be marked on adetailed road map showing the exact route tobe driven.

These maps should be used during the actualdrive for navigation of the test vehicle.

They can also be used during the drivetest



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verification to check that the positioning information in the drivetest file is correct.

A separate map should be prepared for each route.

Both line of site (LOS) and non-LOS points have to be included inthe drive test.


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The data collected should represent typical coverage scenarios.

In urban area the effect of street orientations have to beconsidered.

The selection of drive test route should be based on the terrainvariations, Major highways and throughfares, potential shadowingareas and handoff region.


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DRIVE TEST PROCEDURE

The actual dive test must be performed carefully to insure that thedata collected is accurate.

It is important that all equipment used be tested and all setupinformation be recorded.

If any of the procedures are not followed or any of the data is notproperly recorded then the drive test data will not be usable and thedrive will have to be repeated.




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Engineer should study the drive test plan ahead of time andhighlight the intended drive test routes.

For each drive test a team of two people should get involved.

The measurement process should be stopped the car stops ( egnear traffic lights) or whenever the sampling and measurementslook suspect.


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DRIVE TEST OUTPUT

The result of drive test is a collection of data files which has lat, long,Received Signal Strength Indicator (RSSI) at that point and thefrequency.

The location information ( lat, long ) is used by the post processing toolsas a reference of correlation between the measured vs. predicted signallevels for measurement integration.

This file has to be transferred onto the planning tool either by a floppyor by data transfer using LAN.

Lat Long RSSI FreqX1 Y1 M1 F

X1 Y1 M1 F

X1 Y1 M1 F



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DRIVE TESTOUTPUT



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ModelTunning


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Model Tunning

Model Tuning On Asset version 6.1

Model Tunning


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Models are used to predict path loss.

Different models are used for different purpose. Eg:- Rural Macro-cell-Okumura hata model, Micro cells - Ray tracing

Models have to be tuned using data collected by drive testing.

Good propagation tool + Sound engineering ingenuity = Sound RFdesign.

Some of the popular prediction models are Okumura hata, WalfischIkegemi, COST231, Ray tracing etc.

Model Tunning

Model Tunning

Model Tunning


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Okumura Hata Model

This is used for Macro cell modeling.

It has become the most popular propagation model for mobileenvironments.

It is best applicable for cell ranges of 5 to 20 kms.

Model Tunning

M d l T i


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Model Tunning

Below a range of 1 km it becomes very unreliable since obstacles in

the close vicinity of receiver and transmitter become the dominantscattering influences which are not taken into account in theformula.

Path loss = K1 + K2log(d) + K3log(Heff) + K4 * Diff +K5log(Heff)log(d) + K6log(Hmeff) +K7log(f) + Kmorphology

M d l T i


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Model Tunning

K1 - 1Km intercept value. Upto this point model assumes free spaceloss

K2 - Slope value

K3 - Effective height coefficient

K4 - Coefficient for diffraction calculation

K5 - Hata model multiplier

K6 - Multiplier for mobile height

K7 - factor for frequency

M d l T i


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Model Tunning

model has four main parameters:

Building separation (in meters) (b) : It is the distance betweenthe centre of two buildings.

Average building height (h) : This is the average height of allbuildings in the cells coverage area.

Road width (w)

Road orientation angle ( )

Model Tunning


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h

w

b

d

Walfish Ikegami Model

Model Tunning


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MODEL TUNING

Propagation models use clutter and terrain data to predict cellcoverage at a site. However usually the terrain and clutter dataavailable from the maps are not perfect.

This means that the actual cell coverage could be different from thepredicted cell coverage. This could in turn result in wrong celldesigning.

To avoid this model tuning is done.

Model Tunning

M d l T i


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Model Tunning

In model tuning data collected from the propagation test is loadedon the planning tool.

This data represents the real life condition cell coverage.

The prediction for that cell is then done using the same conditionsas were for the propagation tests (i.e. using the same antenna type,same height of the antenna at the site, same downtilts, same

transmit power etc.

d l i


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MODEL TUNING

Ideally both the propagation test cell coverage and the predicted cellcoverage should match.

If they match then the model does not require to be tuned.

If the models do not match then the certain parameters in thepropagation model equation are altered so that they both match.

Model Tunning

Model T nning


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Model Tunning

Once both the cell coverage match the model is then said to betuned.

Now the actual antenna type, height of antenna, transmit power are

used and prediction done.

This prediction can then be assumed to be correct.

Cell designing is then done using this prediction.

M d l T i


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MODEL TUNING

Ideally model tuning needs to be done for all the sites.

However in many cases , the Network is divided into different clutter

types (around 7 to 8) (e.g. urban, dense urban, semi urban, rural etc.)and models are tuned for each clutter types.

The sites are then categorized in these clutter types and then fitted inthe model tuned for that clutter type.

This method though not perfect is widely accepted and saves lot of

time and money for the operator.

Model Tunning

You must have an existing project with map data


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and with CW sites. In the below mentioned slidethere are total three sites for tuning.

th tt f O i t


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the pattern of Omni antenna.

Make the Feeder cable


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from Equipment > Click on Feeder

g c c on e spec c pro ecli k N F d


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g p p> click New Feeder

ve ee er ame ay nP ID d li k l


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yPart ID and click on close

Update the site database for


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Update the site database forantenna , model and feeder type

From Configuration > Propagation


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From Configuration > PropagationModel

> click Add > select any reference


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ymodel(Say standard Macrocell 3) >

Click Add

(Say 1900)> click View/Edit Model


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( y )Parameter

e re a ve n orma on sayF ) i l t b


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Frequency) in general tab

-va ues n orma on rom userguide


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guide

oose ec ve an enna e galgorithm (say Relative)


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algorithm (say Relative)

oose rac on ca cu a onMethod (say Epstein Peterson)


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Method (say Epstein Peterson)

n a roug c u er osses anclutter offsets will be 0 No need to fill


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clutter offsets will be 0. No need to fillthe value in this tab

Importing the CW Drive test file


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From Tools > Click Measurements

Measurement toolbox will open > ClickAdd in cell associate measurement >


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Add in cell associate measurement >Browse Header(.hd) file > click open

mpor ng o r ve e w a efew minutes


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few minutes

information are same then loading will


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ask for the association of drive datawith cell > Click OK

Click on Load Associated


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Similarly Import the other drive(Signia) files


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(Signia) files

measurements>click Individual > Model Analysis


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Tool Box will pop up > In Model tab, Fill the requiredinformation > Select the Model

n er a > ve s ance er ng >Rx Level Filtering > Clutter filtering >


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Rx Level Filtering > Clutter filtering >Polygon Filtering

analysis > Check Measurement Signal > View the drivedata in 2D view with sites > Click on Create new vector


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data in 2D view with sites > Click on Create new vectorfrom 2D menu > Give vector name (Say 1900)> Select

polygon shape > make polygon for the bad drivesamples > Save all vectors

Check Use Exclusion Polygons box > ClickS l l h k h ifi l


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Select polygons > check the specific polygon >click on Apply

o ygon e ec e w s ow you e noof Exclusion polygons > click OK


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p yg

measurement > click Composite. This will givecombine al es Yo can also do the anal sis for


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combine values. You can also do the analysis forindividual drive data

After the completion of compositeanalysis this will give you the values as


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analysis this will give you the values asslide is showing

ou can a so v ew e ana ys s reporfrom here > Click View Report >


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pAnalysis will run

er e comp e on o ana ys s an op onbox will pop up > choose the desired


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p p poptions > Click OK

Analysis report will generate (See the below mentioned specimen) In this caseYou can see that mean error & Std. Dev is not matching with exact

criteria.Actually mean value should be 0 and Std. Dev should be less or equal to


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y q8

Analysis report will generate (See the below mentioned specimen) In this caseYou can see that mean error & Std. Dev is not matching with exact criteria.

Actually mean value should be 0 and Std. Dev should be less or equal to 8. After


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y qtuning the value of K1, K2 and K7 we will get the exact report as given

After Analysis you need to do the tuning fori d lt S l t th t


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improved results. Select the measurements> Click Auto Tune

Initialization of Auto tuning will takefew minutes


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few minutes

Model Calibration Utility box will pop up. This will show youthe reference model K-value. Also at the moment Throughclutter losses are 0 You can see the same from; Clutter >


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clutter losses are 0. You can see the same from; Clutter >View/set Through clutter parameters

auto tuning you can fix or open the clutterlosses values. In the below mentioned slide all


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clutter loss values are open.

the K-values. For eg. In the below mentioned slideK2 is open while others are fix For Auto Tuning Go


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K2 is open while others are fix. For Auto Tuning Goto Tools> Auto Tune

Auto Tuning will take Few Minutes time


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u o un ng w g ve you new an c u er va ues.you want to apply the new values go to Tools >

Appl Ne parameters


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Apply New parameters

You also can see the new clutter lossesvalues


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values

This will complete the Auto Tuning Process.Now From File > Click Exit


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Now From File > Click Exit

>Propagation Model> Select Specific Model >View/Edit model Parameters > Path loss tab


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View/Edit model Parameters > Path loss taband then > Clutter tab


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Antenna

BASIC INTRODUCTION TO ANTENNA


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What is antenna?

An antenna is the converter between cable boundedelectromagnetic waves and free space waves.

Antenna installation configurations depend on the operators preferences.

It is important to keep sufficient decoupling distances between antennas.

If TX and RX direction use separated antennas, it is advisable to keep a horizontalseparation between the antennas in order to reduce the TX signal power at the RXinput stages.

ANTENNA INSTALLATION

Antennas for GSM System


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Antennas for GSMSystem

Antennas for GSM System


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(Technical Data)

B l a h

b l a h

b l a hb l a h


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Electrical properties


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1 dipole (received power) 1mW

Multiple dipole matrixReceived power 4 mW

GAIN= 10log(4mW/1mW) = 6dBd


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Gain=10log(8mW/1mW) = 9dBi

Sector antennaReceived power 8mW

Omnidirectional arrayReceived power 1mW

(Overlook

Antenna


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Frequency Range

GSM 900 : 890-960MHz

GSM 1800 : 1710-1880MHz GSM dual band : 890-960MHz & 1710-1880MHz

eg.824-960MHz 1710-1900MHz


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BANDWIDTH

= 960 - 890 = 70MHz

Optimum 1/2 wavelength

for dipole at 925MHz

at

960

MHz

Antenna

Dipole

at

890

MHz


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Impedance

50

Cable

50 ohms

Antenna

50 ohms


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9.5 W80ohms50 ohms

Forward: 10W

Backward: 0.5W

Return Loss 10log(10/0.5) = 13dB

VSWR (Voltage Standing Wave Ratio)

VSWR


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Polarization

Vertical Horizontal

+ 45degree

slant- 45degree slant


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V/H (Vertical/Horizontal) Slant (+/- 45)


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Linear, vertical

45 dual linear 45 slant


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Dipole

Ideal radiating dot source

(lossless radiator)

eg: 0dBd = 2.15dBi

dBd and dBi

2.15dB


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Pattern :-


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Beamwidth

120 (eg) Pea

k

Peak -

10dB

Peak -

10dB

10dB Beamwidth

60 (eg) Pea

k

Peak -

3dB

Peak -

3dB

3dB Beamwidth


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3dB3dB Beam width Horizontal

Directional Antenna 65/90/105/120 Omni 360


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Directional Omni-directional

3dB

3dB Beam width Horizontal


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Demonstration of Electronic Down-tilt


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Non down tilt

Electronic downtilt

Mechanical

downtilt

(Electronic and mechanical down tilt)


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Front to Back Ratio


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Ratio of maximum main lobe tomaximum side lobe

F/B = 10 log(FP/BP) typically 25dB

Back

power

Front

power


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Side lobe

In (dB)

In (dB)


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Mechanical properties


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Mast

Mast diameter 45-90mm


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(Antenna Types and Development )

(Antenna Types)


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By frequency band: GSM900, GSM1800, GSM900/1800By polarization: Vertical, Horizontal, 45 linear

polarization, circle polarization

By pattern: Omni-directional, directional

By down-tilt: Non, mechanical, electronic

adjustment, remote controlBy function: Transmission, receiving, transceiving


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ONE ANTENNA FOR MULTIPLE BANDS

870-960MHz and 1710-1880MHz

Extended band option with 806-960MHz

Dual slant 45 polarisation

65 horizontal beamwidth

Band independent Teletilt control

17dBi gain in both bands

Diplexed or Non-Diplexed versions

Mechanical downtilt mounting option


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7/8 MAIN FEEDER


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1/2 JUMPER CABLE


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Planning


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Coverage Planning Strategies



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The selection of siteconfigurations, antennas andcables is the core of the coverageplanning strategy. The right choicewill provide cost savings and

guarantees smooth networkevolution.

Some typical configurations are:

3-sector sites for (sub) urbanareas

2-sector sites for roadcoverage

1

2 4

5 6

7

3

1

2 4

5 6

7

3

1

2 4

5 6

7

3

1

2 4

6

7

3

1

2 4

5 6

7

3

12 4

5 6

7

3

1

2 4

5 6

7

3

5


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NetworkPlanningTool:-


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Network Planning Tool:-

Planning tool is used to assist engineers in designing and optimizing wirelessnetworks by providing an accurate and reliable prediction of coverage, doingfrequency planning automatically, creating neighbor lists etc.

With a database that takes into account data such as terrain, clutter, andantenna radiation patterns, as well as an intuitive graphical interface, the

Planning tool gives RF engineers a state-of-the-art tool to:

Design wireless networks

Plan network expansions

Optimize network performance

Diagnose system problems


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The major tools available in the market are Planet, Asset, Net-Act,Cell Cad.

Also many vendors have developed Planning tools of their own likeNet plan by Motorola, TCPU by Ericsson and so on.

Propagation Test Kit


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Propagation Test Kit

The propagation test kit consists of

Test transmitter.

Antenna ( generally Omni ).

Receiver to scan the RSS (Received signal levels). The receiver scanningrate should be settable so that it satisfies Lees law.

A laptop to collect data.

A GPS to get latitude and longitude.

Cables and accessories. Site Master to check VSWR.


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A single frequency is transmitted a predetermined power level fromthe candidate site.

These transmitted power levels are then measured and collected bythe Drive test kit. This data is then loaded on the Planning tool andused for tuning models.

Commonly Graysons or BVS test kits are used.


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RF Network Design

COVERAGE PLANNING

Frequency Bands


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GSM-900

The term GSM-900 is used for any GSM system which operates

in any 900 MHz band.

P-GSM-900

P-GSM-900 band is the primary band for GSM-900 Frequencyband for primary GSM-900 (P-GSM-900) : 2 x 25 MHz

890 915 MHz for MS to BTS (uplink)

935 960 MHz for BTS to MS (downlink)

E-GSM-900

In some countries, GSM-900 is allowed to operate in part or inall of the following extension band. E-GSM-900 (Extended GSM-900) band includes the primary band (P-GSM-900) andthe

extension band :



Frequency Bands


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R-GSM-900

R-GSM-900 (Railway GSM-900) band includes the primary band (P-GSM-900) and the following extension band:



GSM-1800

Frequency band: 2 x 75 MHz

1710 1785 MHz for MS to BTs (uplink)


Carrier Spacing and ChannelStructure


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Channel number the carrier frequency is designated by theabsolute radio frequency channel number (ARFCN). The frequencyvalue of the carrier n in the lower band is called FL(n) while FU(n) is

the corresponding frequency value in the upper band. Frequenciesare in MHz

P-GSM-900:

FL (n) = 890 + 0.2 n with 1 < n < 124

FU (n) = FL (n) + 45

E-GSM-900:

FL (n) = 890 + 0.2 x n with 1 < n < 124

FL (n) = 890 + 0.2 x (n-1024) with 975 < n < 1024

FU (n) = FL (n) + 45

Coverage, Capacity, and Quality


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Providing coverage is usually considered as the first and most

important activity of a new cellular operator. For a while, everynetwork is indeed coverage driven. However, the coverage isnot the only thing. It provides the means of service and shouldmeet certain quality measures.

The starting point is a set of coverage quality requirements.

To guarantee a good quality in both uplink and downlinkdirection, the power levels of BTS and MS should be inbalance at the edge of a cell. Main output results of thepower link budgets are:

Maximum path loss that can be tolerated between the MS andthe BTS

Maximum output power level of the BTS transmitter.



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These values are calculated as a function ofdesign constraints:

BTS and MS receiver sensitivity levels

MS output power level

Antenna gain

Diversity reception

Losses in combiners, cables, etc.



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The cell ranges are derived with propagation loss formulas such asOkumura-Hata, using inputs of maximum path loss, differences inthe operating environments and the quality targets in different cellranges.

The traffic capacityrequirements have to be combined with thecoverage requirements, by allocating frequencies. This also mayhave impact on the cell range.



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The selection of site configurations, antennas and cables is the coreof the coverage planning strategy. The right choice will providecost savings and guarantees smooth network evolution.

Some typical configurations are:

3-sector sites for (sub)urban areas

2-sector sites for road coverage

omni sites for rural areas



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These are not the ultimate solutions, decisions should bebased on a careful analysis

Cell Range and Coverage Area

For any site configuration, the cell ranges can bedetermined given the equipment losses and gains. The sitecoverage areas can be calculated then and these will lead tothe required number of sites for a given coverage region.This makes it possible to estimate the cost, e.g. per km2, to

be used for strategic decisions.

Methodology


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Define design rules and parameters

Identify design rules to meet coverage and capacity targetsefficiently

Acquire software tools and databases

Calibrate propagation models from measurements

Set performance targets

Clear statement of coverage requirements (roll out and quality) Forecast traffic demand and distribution

Test business plan for different roll out scenarios and quality levels

Methodology


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Design nominal plan

Use computer tool to place sites to meet coverage andcapacity targets

Verify feasibility of meeting service requirements

Ensure a frequency plan can be made for the design

Estimate equipment requirements and costs

Develop implementation and resource plans (includingpersonnel requirements)

Radio plan will provide input to fixed network planning

Nominal RF Design


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Link Budget

Maximum

path loss

Propagation

model

Typical site

configuration

Site radius

Nominal RF

Design

(coverage)

Coverage

requirements

Nominal site

count

Coverage site

count

Transmit Power Antenna configuration

(type, height, azimuth)

Site type (sector, omni)

Traffic

requirements

Standard hexagon site

layout

Friendly, candidate sites Initial site survey inputs

Traffic site

count

Traffic > Cov.

Cov. > Traffic

Recalculate the site

radius using the

number of sites from

the traffic requirement Repeat the nominal

RF design

Traffic

requirements

Methodology


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Implement cell plan Identify physical site locations near to nominal or

theoretical locations, using search areas.

Modify nominal design as theoretical sites arereplaced with physical sites

Modify search areas in accordance with evolvingnetwork.

Produce frequency plan

Fixed cluster configuration, can be done manually. Flexible, based on interference matrix using anautomatic tool.

Methodology


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Optimizing the network

Expand the network

In line with the roll out requirement In line with the forecasted traffic level

Improve the coverage quality

Maintain the blocking performance

Fade Margin


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The concept of a fade margin is to reserve extra signal power toovercome potential fading.

Assume :

The mobile radio system needs an signal level of Pr dBm atthe receiver

The maximum likely fade (loss) is calculated to be L(fade)dB

The a received signal level of Pr dBm can be ensured by

transmitting enough power for a normal received signal level of (Pr+ L(fade)) dBm

Fade Margin


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The fade margin is normally equal to the maximum expectedfade or to a smaller value. The value is chosen in such a waythat the threshold value is undershot in only a lowpercentage of time.

For this purpose, it is necessary to know the probabilitydensity function of the fading.

In RF planning, the impact of Rayleigh fading is taken intoaccount by implementing an extra fade margin of 8 dB.

Multipath Propagation


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The radio wave may be reflected, from a hill, a building, a truck,an

aeroplane or a discontinuity in the atmosphere. In some cases, the

reflected signal is significantly attenuated, while in others almost

all

the radio energy is reflected and very little absorbed. The result isthat

not one but many different paths are followed between the

transmitter

and receiver. This is known as Multipath Propagation



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Building

Building

Building



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Reflection and multipath propagation can cause positive andnegative effects :-

Coverage extension

Multipath propagation allows radio signal to reach behindhills and buildings and into tunnels

The latter effect is known as ducting



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Constructive and destructive interferenceThe interference due to multipath propagationmanifest itself in the following 3 most importantways:-

Random phase shift creates rapid fluctuations in the

signal strength known as Rayleigh fading

A delay spread in the received signal causes each symbolto overlap with adjacent symbols : intersymbolinterference

Random frequency modulation due to different dopplershifts on different paths

Propagation Modeling


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Statistical propagation models

These calculate a median signal for each pixel. The level withinthis pixel varies about the median in a way that can only beanalysed statistically.

Local mean signal levels are distributed around the pixelmedian with a log-normal probability distribution.

Formulas derived from measurements (e.g. Okumura-Hata).

No obstacles assumed to be close to the BTS antenna.

Deterministic propagation models

Take into account individual buildings and use ray tracingtechniques.

Make use of high resolution map data (at least 10m).

Cellular Architecture


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The essential principles of the cellular architectures are :-

Low power transmitters with antenna heights between 20 50 m

Small coverage zones (cells), typical macro cell radius 3 30 km

Frequency reuse (factor n = 3, 4, 7 ... )

Cell splitting to increase local capacity

Micro and Pico cells act as patches for hot spots, tunnelsand buildings

Balance is to be found between conflicting requirements of :

Coverage

Traffic capacity

Cell Clustering


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Frequency reuse is the core concept of the cellular mobile radiosystem, given the fact that the number of allowed frequencies isfixed. A frequency can be reused simultaneously in different cells,provided that the cells using the same frequency set are far enoughseparated so that co-channel interference is kept at an acceptablelevel most of the time.

The total frequency spectrum allocation can be divided into K

frequency reuse patterns.

Cell Types


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The 2 main cell types are :-

Omni cells :

Coverage is in principle acircle, but in reality arough pattern

Sector cells :

2 sectors (e.g. forhighways)

3 sectors

Cell Coverage Area

Omni cell (Hexagon) = 2.6 R2

Sector cell (Hexagon) = 1.96 R2

Capacity Planning


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Capacity Planning

Capacity Planning


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Capacity can be understood in simplest terms as the number of mobilesubscribers a BTS can cater for at a given time.

Capacity planning is a very important process in the network rollout as itdefines the number of base stations required and their respective capacities.

When the sector utilization more then 100% then we will go for a newcapacity site in the nearby area.

Capacity plans are made in the preplanning phase for initial estimations, aswell as later in a detailed manner.

The number of base stations required in an area comes from the coverageplanning, and the number of transceivers required is derived from capacityplanning as it is directly associated with the frequency re-use factor.

Capacity Planning


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There are three essential parameters required for capacity planning:estimated traffic, average antenna height, and frequency Re-use.

Estimated Traffic:- Traffic in the network is dependent on the usercommunication rate and user movement in the network. Trafficestimation in the network is given in terms of erlangs. One erlang (1Erl) is defined as the amount of traffic generated by the user when he orshe uses one traffic channel for one hour (this one hour is usually thebusy hour of the network)

Average Antenna Height:-The concept of the average antenna height isthe basis of the frequency re-use pattern determining capacitycalculations in a cellular network. If Antenna Height is low then thecovered area is small in an Urban Area, Exactly the opposite is the casein micro cellular environment.

Frequency Re-use:-Frequency re-use basically means how often a

frequency can be re-used in the network. If the average number of thetransreceivers and the total number of frequencies are known, thefrequency re-use factor can be calculated.

Capacity Enhancement Solutions


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Conventional solutions

Cell splitting Site distance reduction

Interference Reduction Features

New Site Plan

Optimize site properly

Extra Spectrum

Extended GSM (10 MHz)

Dual Band/ Dual Mode

Microcells (Hotspot, Continuous Layer)

Indoor Planning Solutions


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City Planning

City Planning EnhancementSolutions

C ti l l ti


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Conventional solutions

New Site planned Building Height

Tower Heights

Microcells (Hotspot, Continuous Layer)

City Planning

The whole land area is divided into three major classes urban, suburban andrural based on human made structures and natural terrains


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rural based on human-made structures and natural terrains

City Is coming under Dense Urban, Urban & Suburban.

City Planning requires from the planners is generally a network design thatcovers 100% of the area. Fulfilling this requirement is usually impossible, soefforts are made design a network that covers all the regions that maygenerate traffic and to have holes only in no-traffic zones.

The cells (sites) that are constructed in these areas can be classified as outdoorand indoor cells. Outdoor cells can be further classified as macro-cellular,micro-cellular or pico-cellular.

Macro Cells:- When the base station antennas are placed above theaverage roof-top level, the cell is a known as a macro-cell. A macro-cellrange may vary from a couple of kilometers to 35 km So this concept isused for rural Environment.

Micro Cells:- When the base station antennas are below the average roof-top level, then the cell is known as a micro-cell. The area that can becovered is small, so this concept is applied in Dense urban and urbanareas. The range of micro-cells is from a few hundred meters to a couple ofkilometers.

Pico Cells:-Pico-cells are defined as the same layer as micro-cells and areusually used for indoor coverage.

Highway Planning

I Hi h l i d Hi h i t ll


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In Highway planning needs High gain antenna as well as more

height. This site is coming under clutter type Rural area.

This site is dedicated to highways & act as an backbone network forthose Rural area nearby the highway.


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Creating a Project

Add a new project from the Add Project

Gi P j N & Ch h F ll i h R i


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Give a Project Name & Change the Following parameters as the Requirement: Coordinate System:-The information is vital to locate the mapping

information on the earths surface. This information is obtained from thedata provided. Map Projection Ellipsoid UTM Zone

Then Click Save button and then press OK.

Creating a Project

Mapping data directory


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pp g y Information relating to the location in the directory structure

of where the particular type of mapping data is heldLine (vector) dataHeightsClutterText

Training On Asset Tool


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Creating a Project

User data directory Di t f t f th d t t


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Directory for storage of the user data types User Preference

Prediction Directory Max Disk Space (Default space 5 GB) Colour Palette (C:\Program Files\AIRCOM International\Enterprise 6.0\Common) Coverage Array Directory User Line Vector (Data)

Creating a Project

Map data extents


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p

Defined the overall area that the user will be able to move around

in the 2-D view Click on Calculate Button.

Asset Planning Tool

Now Project created & Select the project by click on the Start


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j p j yButton.

2D Views Window


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For a new project, the user will need to firstly lay downMSCs and BSCs in hierarchical order.

1. Add MSC

2. Add BSC

3. Add Sites

4. Moving

5. Deleting

6. Moving antenna

7. Re-orientatingantenna

Site Database Window


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Site Database


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Site Database


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To get all information regarding a site, Like GSM AntennaHeight, type, power, Lat/Long.

Site Database


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Site Database


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Site Database


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Analysis

Predictions for all sites to be analysed are required beforel i i d


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any analysis is done

Analysis - Array Creation


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Create Array

Create/display

Array

Coverag

e

Statistic

Add cell to

coverage

array

Add site tocoverage

arrayDisplay

coverag

e for a

cell

Displaycoverage

for a site

Cell signaldifference



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Use to analysis network with frequencyhopping turn-on

Use to analysis network without

frequency hopping turn-on



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Minimum signal level at which a

cell is considered to be a serving

cell



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Use when there are predictions of

different resolution, to interpolate

and smooth all the different

resolutions to the selected one to

give a continuous resolution

coverage array

Settings


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Options - Carriers

Settings

Option - Group


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Settings

Option - Carrier Layers


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Settings

Option - Cell Layer


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Settings

Option - Cell Layer


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Create Array

Select the filter in Create Array windows & Press OK.

Th P i f th C t A


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Then Processing for the Create Array.

Asset Planning Tool

After Processing Prediction Plot of the Site.

F lti l Sit l t i d Sit th f P di ti


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For multiple Site we can select required Site the go for Prediction.

Single Site Prediction Multiple Site Prediction

Report


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Export

The project can be exported to the following format :


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The project can be exported to the following format :-

Coverage (MapInfo bitmap)

Enterprise

Coverage (Coversoft/GSM Association V6)

Coverage (InterGraph)

Coverage (MapInfo Mif) Coverage (MapInfo Tiff)

Neptune

NPS/10

NPS/X

PlaNet/EET

Import

Asset can import data from :


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Asset can import data from :-

Enterprise

Neptune

NPS/X

PlaNet/EET


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!!!! END !!!!

Asset Planning Trainning

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