planif 3g -en
TRANSCRIPT
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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.
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Chapitre4 Use of the software tool
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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Chapitre4 Use of the software tool
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.
Radio planning of a network 3G
Figure 4. ! $(&nition des propri(t(s d)un site
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Chapitre4 Use of the software tool
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.
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Figure 4. * $(&nition des propri(t(s d)une antenne
Figure 4. +Facteurs de cali,rage d)un 'od-le depropagation
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Chapitre4 Use of the software tool
%uto'atic &gure 4 #ali,ration of a 'odel of propagation Figure 4./ Weakenings per classof sursol
onsidering nonthe availability of the measuring devices for a network &%'$ we were restricted touse a model gauged on the Algerian territory for a fre!uency of
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Chapitre4 Use of the software tool
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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Chapitre4 Use of the software tool
'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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Chapitre4 Use of the software tool
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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Chapitre4 Use of the software tool
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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Chapitre4 Use of the software tool
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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