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Chapitre4 Use of the software tool

4.1 General presentation of the softwareAtoll is a software tool multi-technologies of radio planning makes to support work of a mobile

operator of radiocommunication during all the life cycle of the network.

Among its characteristics:- Advanced Options of design of network: performance of calculation, support of networks in layers,

automatic planning of codesfre!uencies, support of various technologies of access and support ofnetwork multi-technologies "#$%&%'$ e.g.()

- *le+ible and open Architecture: support of the general formats of files and databases of other

software)

- Atoll consists of a principal core and optional modules as module &%'$, the module of

calibration of models of propagation, the automatic module of planning of the codes and the

module of connections *.

Principal window

Figure 4.1 principal Window of the software and topographic chart of Oran

- rincipal /one where the user can visuali/e the numerical chart as well as the established sites and

the charts of calculations, or a basic table of data "e.g. of the sites or the antennas()

0- 1one of e+ploration to three miters: the first 23onnes5 comprises the elements of the

network and various calculations and predictions, the second 2#o5 indicates the components

of the numerical chart and the data which it contains "model digital ground, basic

infrastructures, heights, population, etc( and the last 2modules5 contains the various models

of propagation including the standard model)6- Observer of events to post calculations in the course of e+ecution.

Radio planning of a network 3G

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4.2 Stages followed in a project of planning of a network

UMS- 'o create a new pro7ect and to choose &%'$83%A like technology)

- 'o import the geographical data)

- 'o create the network by using the models of stations. 'o define the parameters of the sites,the transmitters and the radio operator parameters specific to &%'$)

- 'o gauge the model of propagation used)

- 'o define a /one of calculation and parameters of calculation "resolution, models, properties

of the receiver()

- 'o create and carry out the studies of cover "by transmitter, level of signal, /ones of

overlapping()

- 'o define the parameters of traffic multiservices "services, types of mobility, user profiles,

environments()

- 'o create the charts of traffic by environment)

- 'o define the neighbors of each cell manually or automatically)

- 'o obtain instantaneous sights of the network by simulating the traffic)- 'o proceed to the studies specific to &%'$ based on the load of the network)

- 'o allocate the codes of confusion to the cells)

- 'o check and validate the results by data of mobiles of test.

4.! "reparation of the dataCreation of a new project

'o start, the user must create a new pro7ect. 'he software gives the choice among technologies

which it supports. *or our case, technology to be chosen is 2&%'$ 83%A5 "fig. 4.0(.

Figure 4.2 #reation of a new project UMS W#$M%

Importation of the geographical data

'o be able to work on a real chart, the user must import the geographical data of the ground to be

planned "height of the ground, type of the sursol, etc(. 'he mobile telephone operators, whose

%obilis, use adigital chart of model of ground DTM

obtained from the ;' "national institute

of cartography and teledetection(. Once the digital model of the charged ground, of the called useful

e+tra informations vectors can be charged, like the roads, the streets, the highways, the airports, the

rivers, the lakes, etc

#eographical information makes it possible the

software to carry out calculations of propagation

and the user to better choose the site of the sites.

An e+ample of the topographic chart of Oran

with some vectors is the sub7ect of figure 4..

Definition of a site

At the time of the addition of a new site, several

parameters are to be defined: its geographicalposition "longitude and latitude(, its height and

the type of e!uipment used. 'he radio properties


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are introduced into the definition of the transmitters since the sectors of a site do not have

necessarily the same configuration.

Definition of a transmitter

A transmitter characteri/es each sector of a site. One can define his name, the site to which it

belongs, the distance which separates it from its site "in general null(, its losses in emission and

reception, its factor of noise, its height, the model of the antenna used "selected among the

beforehand definite models(, its a/imuth, its downtilt "slope(, the carrying one that it uses,

ma+imum si/e of active the set, ma+imum power and powers of the channels , $ and

s, its neighbors, her state of activity and the model of propagation used during calculations.

Figure 4.4 $e&nition of the properties of a trans'itter

Definition of an antenna

One can define for an

antenna his profit, his

diagram of radiation

"vertical and hori/ontal(

and his waveband of work.

'hese data can be obtained

starting from the datasheet

of the antenna. n the

definition of a transmitter,

its antenna is selected

among the antennas thusdefined.


Figure 4. ! $(&nition des propri(t(s d)un site

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Calibration of a model of propagation

'he models of propagation must be gauged to correspond as well as possible to the real

environment. t is necessary to put on the ground some sites whose sites represent all the mediums

of the /one of planning "urban, suburban, urban dense, and rural( and the various conditions ofpropagation, and to proceed, thereafter, with the calibration of the model of propagation for each

type of propagation medium by carrying out measurements on tra7ectories belonging to the

coverage areas of the principal

lobes of the antennas. 'hen the

results of measurements are

compared with the results of

calculations of the model of

propagation to gauge and the

values of the various factors as

those of weakenings for eachtype of sursol are fi+ed.

n the software Atoll, a model of

standard propagation based on

the model ost-astened

proposes a general formula with

several factors to be defined.

'he choice of the factors can be

done manually but it is of a

great comple+ity. 'he software

tools for planning "including

Atoll( include an automaticfunction of calibration: while

entering a file of results of

measurement carried out on a

way and by indicating the

broadcasting transmitter used and the model to be gauged, the software calculates the coefficients of

the general formula automatically.


Figure 4. * $(&nition des propri(t(s d)une antenne

Figure 4. +Facteurs de cali,rage d)un 'od-le depropagation

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%uto'atic &gure 4 #ali,ration of a 'odel of propagation Figure 4./ Weakenings per classof sursol

onsidering nonthe availability of the measuring devices for a network &%'$ we were restricted touse a model gauged on the Algerian territory for a fre!uency of

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Figure 4.0 $istri,ution of the eniron'ents dense Ur,ain Ur,ain and Su,ur,ain

Distribution of the sites

8hile basing itself on calculations of the >6.. which give the number of sites for each

environment, and by applying a grid similar to that of figure 6.4, we obtain the distribution of thesites on the /one of planning. $ee fig. 4.=.

Figure 4.13 $istri,ution of the sites

Choice of a zone of calculation


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'he /one of calculation is a polygon drawn on the chart defining the transmitters concerned with

re!uired calculation. 'his makes it possible to reduce the computing time and to obtain more

precise results. 'he transmitters used for calculation will be those of which the ray of calculation

"value to be defined( reached the /one of calculation.

Note:for the captures of screen of various calculations and predictions which will follow, only the

dense urban area will be represented for a better illustration of the results. 'he same stages !uoted

for this /one are repeated for the /ones urban and suburban.

4.4 Studies of predictionPredictions of the cover b level of field

'his prediction makes it possible to consider the power received by a mobile in each point of the

/one of calculation. 'he ob7ective of this study is to detect possible blind /ones and to try to

eliminate them while proceeding to modifications from the configuration from the sites and

transmitters like a displacement from site, a change of the a/imuth of a transmitter, an ad7ustment of

power or a slope "tilt( of an antenna.

Figure 4.11 "rediction of the leel of &eld

Prediction of the !c"Io report"ratio of pilot channel CPIC#

'he mobile uses the ?co reportratio of the to decide which cells which surround it offers

a better !uality of signal. 'o cure the possible defects met, of the changes similar to those !uoted

above are useful.


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Figure 4.12 "rediction of the c56o report5ratio of pilot channel #"6#7

Prediction of the state of #andover

'he knowledge of the states of andover is very important since it facilitates the choice of the cells

close to each cell for then defining them in the @;. 'he neighbors of a given cell are the cells

which can take a mobile in situation of andover with it.

%oreover, by using the results of this prediction one can support the handover in the places which

did not benefit from it by decreasing the value from the threshold from handover or by leading other

cells to cover them.

Figure 4.1! "rediction of the state of 7andoer

4.* Speci&c anal8sis'he Atoll software gives the advantage of knowing the various radio operator parameters in a point

of the chart. y choosing the type of study analyzes specific,in a pro7ect &%'$, one can use themiters: 2rofile5, 2@eception5 and 2@esults5 to estimate the level of signal of the received


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while the miter 2Analy/e A?5 gives a prediction on the !uality "?co( of the and the state

of connection for the mobile.

$eception and profile compared to a given transmitter

'his study makes it possible to draw the ellipsoid of *resnel between the ?& and the selected

transmitter. 'he utility of this information appears if an obstacle hides the ?& completely. 'he most

obvious solution to this problem is to seek a site higher than that selected for this site. Another

information is the level of signal coming from this transmitter with a calculation based on the modelof propagation used.

Figure 4.14 9eception and pro&le in a point co'pared to a gien trans'itter

%etter levels of reception

8ith Atoll, the visuali/ation of the level of signal of each active transmitter in the network is

possible. y selecting only one carrying one can choose other cells candidates to belong to the

A?.

Figure 4.1* :etter leels of reception in a point

&ctive set analzes

'his miter posts the reception of the in terms of the elements of the A?.

$uch a study checks the availability of a service "characteri/ed by necessary ?co( for a type of

mobile "characteri/ed by its power of emission and ma+imum si/e of the A?(. 'he cells

represented by gray sticks are the members belonging to the A? while the white sticks represent

those which do not observe the conditions of the A?.

Figure 4.1+ speci&c %nal8sis of %ctie the Set


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4.+ %uto'atic allowance of the codes of confusion

Figure 4.1 auto'atic %llowance of the codes of confusion

'o ensure a sufficient separation between the cells using the same code of confusion, a planning of

the codes is necessary.

'he user can choose the parameters taken into account by the algorithm of allowance:

- ells close to a cell: if this parameter is chosen, these cells will have different codes two to two.

'he neighbors of each cell can be manually or automatically defined. 'he handover can be done

only between one cell and its neighbors)

- $econd neighbors "close to the neighbors(: one can impose to them, they also, of the

different codes)

- riteria on ?co: all the cells having a ?co reportratio of their pilot in a margin "to be

defined( compared to that of a certain cell cannot have the same code with it)

- 3istance from re-use: it is the minimal distance which can separate two cells having the

same code.

f the algorithm does not arrive to an allowance which fills all the criteria, it generates an error.

'he user must redefine the criteria with more tolerance.


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