Int. J. Communications, Network and System Sciences, 2011, 4, 744-755
doi:10.4236/ijcns.2011.411092 Published Online November 2011 (http://www.SciRP.org/journal/ijcns)
Study of a Kit o f G S M R a dio Ope r a t o r Site for
Event-Driven Movable Coverage: Application to the
Deployment of a Site of the Orange Operator
in Ivory Coast
Sié Ouattara1, Georges Laussane Loum1, Koné Adama1, Alain Clément2
1Laboratoire d’Instrumentation, d’Image et de Spectroscopie (L2IS), Institut National Polytechnique Félix
Houphouët-Boigny (INPHB), Yamoussoukro, Côte d’Ivoire
2Laboratoire d’Ingénierie des Systèmes Automatisés (LISA), Institut Universitaire de Technologie,
Angers, France
Received August 29, 2011; revised September 26, 2011; accepted Octo ber 9, 2011
Abstract
The mobile communication is nowadays one of the basic needs of humanity. It is essential to the flourish-
ing of human beings. Considering this reality, the need to use its mobile phone is become more important
and diversified. The subscribers of the various mobile telephone operators are increasingly demanding. This
situation poses the problems of the cover mobile network to the operators and leads them to opt for several
solutions and investments. The mobile operators in order to satisfy their customers use a policy of pushing
the limits of network coverage in time and space for festive moments in targeted zones. Thus, we have con-
ducted a study on the topic: study of a kit of GSM radio site for event-driven movable coverage. This work is
applied to GSM (Global system mobile) network of the operator Orange-Ci, leader of mobile telephony in
Ivory Coast. We thus proceeded under investigation initially of the various aspects of the ordinary sites (mo-
tionless radio site) which are already deployed with Orange-Ci in order to impregnate us infrastructures and
equipment used. This study revealed us that a radio site comprises 4 parts: infrastructures, installations and
energy equipments, installations and radio equipments, and installations and equipment of transmission.
After the first analysis, we made a study of the movable site. The study of the movable site enabled us to see
the various possible solutions to fulfill the basic functions of a movable radio site. After analysis we retained
that our radio site will be built on a truck on which a mast of 25 m maximum length for the antennas will be
embarked, it will be fed by a generator also embarked on the truck and the solution of transmission selected
is the transmission by satellite more precisely technology VSAT. We choose the various equipments (radio,
transmission, energy) according to features which we defined to constitute the kit of movable radio site.
Keywords: Movable GSM Radio Site, Deployment Kit, Movable Coverage, Even-Driven, Generator, Battery
1. Introduction
The sector of telecommunications nowadays makes con-
siderable great strides with the advent of mobile teleph-
ony. Mobile telephony makes leave from now on daily
newspaper humanity and proves to be essential to its
blooming. Thus more and more the needs for use of te-
lephony increase [1]. The customers of the various mo-
bile telephone operators are much more demanding and
want to have access to the services where they are. This
situation poses the problems of the cover network to the
operators who must solve it in order to satisfy their cus-
tomers [2]. Orange-Ci, leader of the mobile telephony
and concerned of the need satisfaction of its customers
agreed to initiate an innovative project. It is within this
framework that we were accommodated with the service
radio deployment and transmission to work on the topic
“study of a kit of GSM radio operator site for event-
driven movable cover”. This project falls under the Or-
ange-Ci policy to set up a solution enabling him to open

S. OUATTARA ET AL.745
or to make denser its network in a relatively short-time
runs in a locality having to shelter a significant event. To
conclude this study we will proceed initially to a presen-
tation of the motionless radio sites to emphasize some of
the various building blocks. Then we conducted a study
on these various blocks to find solutions adapted to the
deployment of a movable radio site.
1.1. Objectives and Specificities
The goal of this work is to suggest a mobility solution for
a temporary coverage network of a zone having to shelter
a significant event. With this fact the pursued goal should
satisfy the following points:
 To design a kit of radio site
♦ respecting the standards of infrastructures and in-
stallations of Orange-Ci;
♦ spreadable in 48 hours maximum, dismountable in
24 hours maximum;
♦ allowing to offer a cover GSM on a minimum ray
of 1 Km;
♦ allowing to run out the traffic for any gathering of
with 2000 people maximum.
 To propose a deployment kit
As regards to the specificities, the site must respect the
following functionalities:
 To be easy to deploy
 To be easy to dismount
 Possibility of transport and installation of the site on a
mobile machine (truck)
 Autonomous (power supply, transmission, radio and
infrastructures embarked).
1.2. Methodological Approach
To lead our study successfully, we will proceed as fol-
lows:
 To study the BTS of motionless sites in Orange-Ci, to
emphasize the various building blocks as well as the
equipment necessary to their deployments;
 To conduct a study on these various building blocks
to suggest solutions adapted to the deployment of a
mobile radio operator site;
 To constitute a kit of deployment of the movable
radio operator site.
2. General Information on the GSM
Network
In this section we present the architecture of a GSM
network (Figure 1) [1,3-10] with a succinct description
of the various elements which composes it.
2.1. MS (Mobile Station)
It is the equipment available to the user to communicate
with, on the network. The mobile station [3] allows sub-
scribers to access the services offered by the network.
2.2. BTS (Base Transceiver Station)
A Base station [3], ensures the radio coverage of a cell
Figure 1. Architecture of a GSM network (here RTCP corresponds to PSTN).

S. OUATTARA ET AL. 746
(basic unit for the radio coverage of a territory) of the
network. It provides an entrance point in the network to
the subscribers present in his cell to receive or transmit
calls. The basic radio station manages the following op-
erations: radio allocation of resources, regulation of the
power of emission of the mobile station, measures qual-
ity of the radio contact.
2.3. BSC (Base Station Controller)
A controller of base station BSC [3] manages one or
more stations and fulfills various missions as well on the
level of the communication as of the exploitation.
For the functions of the communications of the signals
coming from the base stations, the BSC acts as a concen-
trator since it transfers the communications coming from
the various base stations towards a single output. In the
other direction, the controller switches the data towards
the correct base station.
At the same time, the BSC fulfills the role of relay for
the various alarms intended for the center of exploitation
and maintenance. It feeds also the database of the base
stations. Lastly, a last important functionality is the radio
resource management for the covered zone by the vari-
ous base stations which are connected to it.
2.4. MSC (Mobile Switching Center)
It is the switching of the call center. On the one hand it
allows making the connection between the GSM network
and the switched telephone network PSTN/ISDN and on
the other hand it serves as an interface between data-
bases and the radio subsystem [3].
2.5. HLR (Home Location Register)
It is the central database containing information relating
to any subscriber authorized to use the network. So that
the data are consistent across the network, it serves as a
reference for other local databases [3,11].
2.6. VLR (Visitor Location Register)
The VLR [3,11] is a temporary database containing in-
formation on all users (Mobile Stations) in a given region,
and in general it is integrated into the Mobile Switching
Center (MSC).
2.7. AUC (Authentication Unit Center)
It is the authentication center services. It memorizes for
each subscriber a secret key used to authenticate the re-
quests for services and for the encrypting communica-
tions. An AuC is typically associated with each HLR [3].
2.8. EIR (Equipment Identity Register)
Despite the mechanisms introduced to secure the net- work
access and the contents of communications, the mobile
phone must potentially be able to accommodate any SIM
card of any network. It is thus conceivable that a terminal
can be used by a thief without not being able to be located.
To combat this risk, each terminal receives a unique
identifier IMSEI (International Mobile Station Equip-
ment Identity) that cannot be changed without altering
the terminal. According to data about a terminal, an op-
erator may decide to deny access to the network. All op-
erators do not implement such a database [3].
3. Technical Analysis of Radio Coverage
3.1. Study of Immobile Radio Operator Site
Here we present the general architecture (Figure 2) of an
immobile radio operator site and the description of the
various elements which composes it.
A motionless radio site consists of four building
blocks. We have: infrastructures, installations and energy
equipment, installations and radio equipments and instal-
lations and equipment of transmission. In the following
we will conduct a study of the various functional blocks.
3.1.1. Infrastructures
3.1.1.1. The Shelter
The shelter can be a house, a prefabricated shelter com-
monly known as shelter (indoor site) or a roof with four
poles (outdoor site). Its role is to protect the equipment
against the sun and rain.
3.1.1.2. The Support
The support has a role to allow the installation of the air
equipment. It can be a pylon or a mast. In the case of a
pylon, it can be guyed or self-stable. The guyed pylon
uses guys to be able to stabilize itself, which requires the
definition of a ray of guy whereas the self-stable pylon
self-stabilizes by frames.
3.1.1.3. The Cable Trays
Cable trays are used as passage with the cables. They also
protect them. The cable trays consist of an horizontal
part and of a vertical part but for a question of estheteics
the vertical part was not represented on the diagram.
3.1.2. Installations and Radio Equipments
T
his block has the role the establishment of the radio link

S. OUATTARA ET AL. 747
4 U
Installation source
primair e
BAIE
ENERGIE BTS
Ins tallations et
equipements
energie
AbriC hemin de
cables
Bretell es
basses
Bretelles
hautes
Ante nne panneau
Support
Pui t de
terre
Re gl age ti l t
m閏anique
Parafoudre
Cable
閚ergie
Feeder
ID U
OD U
Cable
KX13
Antennes
faisceau

Prim ary source
installation
In stallations a nd
energy equi pments Mechnical tilt adjusting
Panel antenna
Li ghtning
arrestor
Beam
antenna
Hig h straps
Support
Energy
cable


Energy
rack

Shelter Low straps Trayofcables Feeder KX13
cable Ground
well
Figure 2. Architecture of an immobile radio site.
with the users of the network. It consists of several ele-
ments.
3.1.2.1. The BTS
Its role is processing the radio signal to be transmitted or
received through the various electronic modules it con-
tains. It also provides control of the mobile station. Traf-
fic capacity of a BTS is defined by the number of trans-
mitters / receivers (number of TRX) that are installed.
3.1.2.2. The Equipment of the Line of the Antenna
 The straps
These are coaxial cables of transition with 50 Ω of im-
pedance that can make the connection between the BTS
and the feeders (low straps) and between feeders and the
antennas (high straps). The straps must be shortest possi-
ble to avoid the losses. The low straps are flexible and
have a length of 3 m. However the high straps are rigid
with a length of 2 m.
 Feeders or coaxial cables
They constitute the principal supports of connection be-
tween the BTS and the antennas. They are used as con-
nection between the high straps and the low straps and
make it possible to forward the radio waves of the one of
the straps to the other. Various types of feeders are used
according to radio operator engineering taking account of
the heights of the antennas. Thus we have the cables
“7/8” and the cables “1 1⁄4” The feeders “7/8” are used
when the height of the antennas is below 50 m and with
beyond one uses the feeders “1 1⁄4”.
 Panel antennas
They allow to radiate in space the radio waves in desti-
nation of the users or to collect those coming from the
users. The antennas are installed with a height called
HBA, according to an azimuth, a mechanical tilt signal
and an electric tilt signal specified in the radio engineer-
ing of the site. They are of type 900 MHz, 1800 MHz or
900 - 1800 MHz (Dual-band) according to the waveband
used on the site. The main suppliers of Orange-Ci anten-
nas are KATHREIN, JAYBEAM, POWERWAVE. In
general, the principal characteristics for the choice of an
antenna are: profit, the horizontal aperture, the vertical
aperture, impedance, polarization and power.
3.1.3. Installations and Transmission Equipments
The equipments of transmission have the role to establish

S. OUATTARA ET AL. 748
the connection between the BTS and its BSC attachment
called Abis link. The main equipments used are the equip-
ments of radio-relay system but on certain sites we use
optical fiber, leased lines or satellite connections. The
capacity of Abis link depends on the capacity on radio
operator of the site. Thus for the ALCATEL equipments
used by Orange, 12 TRX to a Abis capacity of 2 Mbits/s
(1 E1) corresponds. Thus in general on the Orange-Ci
sites we have 1 E1 or 2 E1.
3.1.4. Installations and Energy Equipments
The installations and energy equipments have the role to
provide necessary energy to the operating of the site.
3.1.4.1. Primary Energy
It is provided by an installation of the CIE (Ivorian
Company of Electricity) or a generator. The power and
the type of installation are given according to the power
required on the site. The Orange sites have a three-phase
connection of 30 A for the sites indoor and 20 A three-
phase for the outdoor sites.
Primary energy can be also a renewable energy source
(solar panels, wind energy, etc.). Orange deploys already
on its network the solar stations.
3.1.4.2. Secondary Energy
If primary energy is an alternative source (by CIE or
Generator), the derived energy of 48 V DC is obtained
after transformation in a bay energy of primary energy.
The bay is composed of converter AC\DC, a system of
battery and an unit of management. Branches batteries (4
batteries of 12 V) of 48 V are installed in bay to be used
as backup in the event of cut of the primary source. The
autonomy of the batteries of the Orange-Ci sites is 08
hours on average.
If the primary energy source is a solar station, the
equipment is directly supplied with 48 V DC via a box of
regulation. The backup is also ensured by a system of
batteries.
3.1.5. Security of the Site
All the indoor and outdoor equipments will have to be
connected directly and individually to the electric mass
barrettes by a green/yellow cable of 50 mm2. The earth
barrettes allow the equipotential bonding between vari-
ous earthings.
All the metal parts attached to the pylon, such as metal
ladders, safety rails, the cable channel and arm swing
must be connected to the descent lightning arrestor to the
high point and low point.
A protecting device against the lightning must to be
envisaged on all the high buildings of which the height is
higher than 25 m. Two types of lightning conductors are
used for this purpose. We have: lightning rods and meshed
cage lightning conductors. A descent lightning, intended
to run out the lightning current towards the meeting point
is realized using a tinned copper flat of section 30 × 2
mm2 or round of section 50 × 2 mm2 placed always out-
side.
The meeting point is realized to improve the value of
the ground which must be lower or equal to 10 Ω. The
conductors used for the constitution of the meeting point
must be from the same section and the same matter as
those used for the descent lightning. According to the
configuration of the site various techniques are used for
the realization of the meeting point.
3.2. Study of a Movable Radio Site
The Figure 3 below illustrates the synoptic presentation
of a movable radio site. It is composed of different parts
to dimension: 1) the radio block, is the part that will
make the connections in the radio coverage zone of the
movable site; 2) the transmission block is the part which
will enable us to establish the Abis interface between the
movable site and its BSC of attachment, 3) the power
supply block is the part which must provide necessary
energy to the operation of the site, 4) the infrastructures,
they are the infrastructures necessary to the installation
of the equipments and 5) the bearing support, it is the
support on which the equipment will be installed. It is
this item that will give the function of mobility to the site
thus giving it the character of movable radio site mobile.
For the good implementation of all its parts it will be
necessary to define, a procedure of deployment and dis-
assembling, it indicates the different steps of deployment
and disassembling of the movable radio site.
4. Technical Solutions and Discussion
4.1. Radio Solutions: Dimensioning, Choice and
Design of Base Station
4.1.1. Concepts of Traffic and Dimensioning
In a GSM network, it is however not only to guarantee a
radio link, but also to guarantee a certain traffic. The
traffic is estimated statistically from the population den-
sity and the type of activity associated with each region.
For example, the probability of call in a zone with high
housing density is very different from the probability call
in a zone with high density of occupation. Erlang laws
[12,13] are used to characterize the rate of phone calls.
This law is parameterized by two parameters: the rate of
call μ, and the average duration of call H. The intensity
of traffic per user is expressed by:
(erlang)
v
AH


 (1)

S. OUATTARA ET AL. 749
BEARING SUPPORT
POWER SUPPLY BLOCK
RADIO BLOCK
(BTS and the line of the TRANSMISSION
INFRASTRUCTURES
DEPLOYEMENT PROCESS AND DISMANTLING
Figure 3. Synoptic presentation of a movable radio site.
Knowing the population density associated with a geo-
graphical zone, it is easy to determine the traffic density
by:
2
(erlang/Km )
H v
AAd (2)
where dH is the population density per Km2.
Lastly, if one is able to predict the covered zone by a
cell, it is then possible to estimate the traffic that the cell
must absorb:
(e r lan g )
tot
AAS (3)
where S is the area of the cell.
Erlang laws allow then determining the number of
channels required to absorb this statistical traffic with a
given failure rate. The B. Erlang [13-15] law is given by
the following formula:
0
1
!
1
!
Nc
tot C
CCn
n
AN
PNAn



(4)
where NC is the number of voice channels.
Thus, from the knowledge of the traffic density and
the surface covered by a transmitter, it is possible to pre-
dict the number of channels to be assigned to a cell to
guarantee a blocking rate below a certain percentage, for
example 2%.
We understand well whereas the deployment of a
network GSM is not based on a radio coverage but on an
intelligent distribution of the radio resources on a set of
base stations.
The number of voice channels available is not equal to
the number of frequency channels. For each cell, it is
necessary to reserve a beacon channel which contains the
synchronization channels (FCH, SCH, and BCCH) [3,
14,15]. These channels allow the mobiles to detect the
presence of the base stations. During the attribution of a
certain number of frequencies at a base station, it is thus
necessary to eliminate one from the frequencies to count
the radio resources.
In addition, each frequency channel is likely to pro-
vide 8 channels of data TCH [14,15]. The total number
of channels is thus equal to 8 times the number of fre-
quency channels.
However, certain common channels, and in particular
the beacon channel, require resources. It is considered in
general that 1/8th of resources is used for the common
channels (including the beacon channel).
Thus, for N channels assigned to a base station, the
number of TCH (NTCH) is given by:
78


TCH
NN (5)
If Nf is the number of carriers assigned, then the num-
ber of physical channels TCH [14,15] available is:
7


C
Nf N (6)
4.1.2. Dimensioning of the TRX of the BTS and the
Choice of the BTS
To dimension our site we should define the parameters
that we have presented above. Since the zone in which
the site will be deployed is not known a priori we based
ourselves on the total intensity of traffic on the Or-
ange-Ci network. We would like to announce that this
traffic varies according to the periods and it had reached
a maximum of traffic of 14.5 mErlang/subscriber. Our
site must be able to cover an event which mobilizes with
2000 people maximum, which requires a traffic of

S. OUATTARA ET AL. 750
2000*14.5 mErlang, i.e. 29 Erlang. The Equation (4) of
B Erlang law indicates 6 TRX to run out this traffic. We
decided to add 2 TRX like margin. Thus in total our site
will include 8 TRX. We can thus plan to use a MBI3
ALCATEL BTS or MBO1. We suggest a BTS MBO1
Alcatel.
4.1.3. Desi gn Study: Dimensi o ni ng of the Radi o
Coverage
The movable site must offer a radio coverage on a mi-
nimum ray of 1 km.
4.1.3.1. Choice of the Waveband
Considering the ray of cover whose minimum is of 1 km,
our movable site can use frequencies 900 MHz or 1800
MHz according to the constraints of our existing plan of
frequency. We thus recommend 1800 MHz band for the
dense-urban zones (objective of traffic) and 900 MHz
band for the urban and rural zones (coverage objective).
4.1.3.2. Choice of Radio Equipments
Solution with the ordinary equip m ents:
 The BTS: a BTS MBO1 in 1800 MHz band or 900
MHz band is thus adapted to the mobile radio site.
Indeed the MBO1 is designed to be installed in out-
door environment and can support up to 8 TRX and
its consumption is less.
 The TRX: to limit the energy consumption and the
interferences that could cause the site, especially in
the case of densification we chose TRX TRADE 1800
MHz and 900 MHz which are TRX of medium power.
 Choice of cables: In the deployment of the immobile
sites, the cables generally used are the coaxial cables.
Two types of coaxial cables are used:
 The “7/8” cables for antenna heights below 50
m.
 The “1 1/4” cables for antenna heights beyond
50 m.
As we will not have heights of antennas beyond 50 m
considering the ray of cover is only of 1 km we thus
choose coaxial cables of the “7/8” type.
 Choice of the panel antenna: Using 2008 Catalog of
the antennas of KATREIN we chose the K742196
panel antenna of KATHREIN because of its charac-
teristics that are here:
 Waveband: 915 - 990 MHz; 1710 - 1880 MHz
 Polarization : +45˚,–45˚
 Gain : 2*15.3 dBi
 Horizontal opening angle: 67˚
 Vertical opening angle: 12.6˚
 Impedance : 50 Ω
 Maximum power: 300 W
Solution with a distributed BTS:
For a movable site, we wish that it be the most flexible
and that it consumes less. The cables for the intercom-
necttion of the radio operator equipment must be flexi-
ble and easy to handle. The use of a MBO1 does not
seem to us suitable considering this one uses coaxial ca-
bles which are rigid, heavy and sometimes cumbersome.
This is why we recommend the use of a distributed BTS
for the realization of the movable radio site. Indeed the
distributed BTS uses optical fiber for the interconnection
of the radio equipment and it has also the advantage of
consuming less. The solution with the distributed BTS
will be thus the principal solution which we adopt.
 Configuration of the mobile site: The site will be by
default a tri-sector site with the S332 configuration.
The number of final sector and the configuration will
be defined by a Design study which will be con-
ducted during the deployment.
 Design radio parameters: These are the antenna
heights, azimuths, tilts of mechanical and electrical
and GPS coordinates of the site [16,17]. These pa-
rameters are defined according to the objectives of
coverage and the location of the site affecting its re-
lief. Since the location of the movable site is not
known a priori (changeable locations), we cannot de-
fine these parameters. However regarding the heights
of antennas we have with the software ASSET set an
estimated value to enable us later to define the length
of the pylon. With the software, we set the design pa-
rameters and we evaluate the radius of coverage ob-
tained. We specify that in this simulation azimuths
and tilts have been taken arbitrarily, the most impor-
tant being the height.
4.2. Choice of the Transmission Technology
Among the different technologies of transmission, we
chose a solution by satellite which supposes the exis-
tence of a satellite link that we will be able to exploit. At
this level, it should be noted that Ci-Telecom (the PSTN
operator in Ivory Coast) has a satellite link and consid-
ering Orange-Ci and Ci-Telecom merged we can use this
link. A transmission by satellite through a VSAT [18]
proves to be flexible, requesting less infrastructures and
easy to implement. The installation of a station VSAT
can be done in half-day, as well disassembling. This so-
lution seems to us adapted, it will thus be adopted. It
constitutes our main solution. However in the case of
deployment of the movable site in the big cities where
exist BSC sites, the solution by radio-relay system can be
considered if it does not require several hertzian jumps.
4.2.1. Description of the Transmission Solution
The solution of transmission will be based on the earth

S. OUATTARA ET AL. 751
The earth station of Yamoussoukro (Figure 5) was in-
stalled in 2000. It consists of a parabolic antenna of 21 m
in diameter and several modems and satellite control
equipment [18]. The station operates in the C-band, 5.856
- 6.425 GHz in emission and 3.625 - 4.2 GHz reception.
It is as follows.
station of Yamoussoukro and the national transmission
network (Ci-Telcom) already existing. A station VSAT
will be installed at the movable site location (see Figures
4 and 5). It will communicate with the earth station of
Yamoussoukro (Figure 6) through satellite IS 905@333.5
of Intelsat. The earth station of Yamoussoukro is con-
nected to the national transmission network (Ci-Telcom)
as well as the various BSC of Orange-Ci. The traffic
could thus be conveyed until the attachment BSC selected.
The attachment BSC will be selected according to the
locality in which the deployment takes to allow the reali-
zation of the Handovers. But for the deployments in re-
mote zones, i.e. zones where the mobile site will not have
contacts of vicinity, we suggest that we choose one of the
three BSC of Yamoussoukro, considering their proximity
of the earth station of Yamoussoukro. The radio equip-
ment (BTS, TRX and cables) will be replaced by the so-
lution of distributed BTS if it is available at the time of
the implementation of the solution.
4.2.2. Confi gu r ation of the Movable VS AT Station
 The bit rate of the station: It is question to estimate
the speed necessary to the flow of the movable site
traffic. The mobile site will be composed of 8 TRX.
To run out the traffic of such a site, an E1 link is suf-
ficient, which fixes the bit rate of the VSAT station at
2 Mbits.
 Type of modulation: In the field of the transmission
by satellite, several types of modulation are used. The
choice of a kind of modulation is done according to
the bit rate, of the FEC (Forward Error Correction)
[19,20] and of the spectral effectiveness. To reduce
MODULATEUR BUC
DEMODULATEUR LN B
OMT PARABOLE
DON NEE
S A
EMETTRE
DON NEE
S
REC UES
IDU OU M odem satelliteODU
Data to
transmit
Data to
receive
Modulator BUC
Demodula to
r
LNB
OMT Parabola
ODUID
U
o
r
Sate
li
tte
m
ode m
IDU or Satellite modem
Figure 4. Diagram of a VSAT station.
Figure 5. BSS architecture of the movable site.

S. OUATTARA ET AL. 752
Figure 6. Synoptic diagra m of the earth station of Yamoussoukro.
the band-width necessary to the flow of traffic and to
avoid an underdevelopment of speed we wish a mo-
dulation which has a spectral effectiveness and a bit
rate fairly high. We thus choose a modulation 8-PSK
[21] with a FEC of 2/3 because this modulation offers
a not too high flow and a relatively high spectral ef-
fectiveness which enables us to reduce the band-
width to allocate and thus the cost of hiring of this
one. In the same way it is the type of modulation re-
commended by the study made by METRACOM for
Orange-Ci within the framework of the project of
Abis connection by satellite. We chose the modula-
tion 8-PSK which has a spectral effectiveness of
3bits/s/Hz and the bit rate of the station is 2 Mbits/s.
We point out that the spectral effectiveness is defined
by: necessary bit rate /Band-width. For 2 Mbits/s it is
necessary thus to have a band-width of 0.35 MHz.
The minimal value of allowable band-width to an op-
erator by Intelsat being of 1 MHz, we retain 1 MHz
like band-width.
 The satellite modem (Indoor Links (IDU)): Our choice
was made on the equipment of the Comtech type
more precisely the Comtech-570 L modem. Indeed
this equipment was already used in similar projects
carried out in other countries. Also they are used at
the earth station of Yamoussoukro; there is thus
competence in their use. Beyond all that the Com-
tech-570L modem presents many other advantages
such as the presence of Ethernet port, the possibility
of varying from type of modulation etc. which en-
ables it to be adapted to various types of applications.
The features of the satellite modem Comtech-570L
are the following:
♦ Bite rate : 2.4 Kbs to 9.98 Mbs
♦ Type of modulation: BPSK, QPSK, 8-PSK, 8-QAM
♦ Interfaces: T1/E1, 10/100 Base T-Ethernet
♦ Quality of service: Optionnel
♦ Compression of headers and useful message
♦ Operating temperature: 0˚C to 50˚C
♦ Power supply: 220 V/50 to 60 Hz
♦ Maximum power: 300 W
 Choice of the ODU: the ODU will be selected in the
range of Comtech equipments for the same reasons as
the satellite modem. The power of the BUC will be of
20W like suggested it the study made by METRA-
COM. For the interconnection of the IDU and the
ODU, we will use LDF4-50A of Andrew cables with
BNC connectors.

S. OUATTARA ET AL.753
 VSAT Parabola: We chose the Prodlin parabolas
marketed by company EDDISTON SBS. Indeed these
parabolas offer an excellent profit and are adapted
perfectly to the C band in which our station must
function. VSAT Parabola will have a diameter of 2.4
m. These features are:
♦ Gain: 42 dB (the maximum)
♦ Frequency of emission: 5.856 - 6.425 GHz
♦ Frequency of reception: 3.625 - 4.2 GHz
♦ Diameter of the parabola: 2.4 m
 The satellite compass: The satellite compass is used
to locate the satellite to allow a better pointing of the
parabola. We choose the satellite compass of Met-
ronic.
 The satellite pointer: Its role is to allow the orienta-
tion and the precise chock of the parabola. For the
satellite pointer our choice was made on the satellite
pointer Wiltek 9103 of Wiltek. Indeed this satellite
pointer also allows making radio measures in the
wavebands of the GSM and the DCS. These features
are the following:
♦ Minimum Bandwidth (Hz):100 KHz
♦ Maximum Bandwidth (Hz):7.5 GHz
♦ Minimum Amplitude (dBm): –120 dBm
♦ Maximum Amplitude (dBm): +20 dBm
♦ Bandwidth of minimum resolution (RBW) (dB;
Hz)
♦ Trip frequency (Hz):0 Hz, 10 kHz and 7.5 GHz
♦ Video Filter (Hz):10 Hz - 1 MHz
♦ Delivered with: power supply, CD containing the
handbook and the software of transfer of informa-
tion
♦ Dimensions (H × W × D) (mm): 190 × 355 × 104
mm
♦ Net weight (kg): 3.6 kg
 The satellite portable: it is essential in the deploy-
ment of a movable radio site. Indeed at the time of the
commissioning the agent of the OMC-R on the site
must communicate with that which is on the level of
the OMC-R. Considering the movable site will be de-
ployed in zones not often covered, the satellite port-
able will allow to establish this communication. Any
satellite portable is adapted.
 GPS receiver: The GPS receiver will allow to deter-
mine the GPS position of the location where the site
will have to be installed, which will allow to deter-
mine the transponder for which the traffic will be
conveyed.
4.3. Energy Solutions
4.3.1. Ch oice of the Option of the Power Supply
The generator offers many advantages for the primary
energy supply of a movable radio site. Indeed the gen-
erator is easily transportable; it is robust what enables it
to resist many displacements. Our choice was thus made
on the generator. The generator constitutes the principal
solution; however in certain cases in particular for the
thickenings in Abidjan one will be able to use a source of
CIE or a solar panel.
4.3.2. Asses sment of Ener gy and Dimensio ni ng of th e
Energy Workshop
4.3.2.1. Assessment of Energy
The following Table 1 presents the assessment of power
which is the power necessary to the operation of all the
equipment installed on the site [22,23]
4.3.2.2. Dimensioning of the Energy Workshop
To dimension the energy workshop we will consider
only the equipments which functions under the tension
48 V. The power of these equipments is evaluated at
5650 W/48 V. Thus two rectifiers of the 3200 W/48 V
type can thus make it possible to provide such a power.
 A rectifier will be intended for the power supply of
the equipment
 A rectifier for the charge of batteries
For the question of emergency we envisage a third
standard rectifier in the same way.
Finally the workshop energy will be composed of 3
rectifiers 3200 W/48 V and 4 branches of battery
 Evaluation of the p rimary power and dimension ing of
the generator: The evaluation of the primary power
takes into account all the put powers concerned
[22,23]. This power is an active power. The power of
the generator is the corresponding apparent power:
Pp = Prectifiers + P220V = 3200 × 2+ 1200 = 7600 W
where Pp corresponds to the active power. It is thus nec-
essary to determine the apparent power (S), One a:
Table 1. Assessment of powe r.
Equipments Quantity consumption
BTS MBO1 1 170 W/48 V
TRE TRADE 8 2240 W/48 V
Satellite modem (IDU) 1 180 W/220 V
Spectrum analyzer 1 300 W/15 V
Bulb neon
and socket-outlet
4 bulbs and
4 socket-outlets 1200 W/220 V
Battery 4 branches
(16 batteries) 2560 W/48 V
Margin 6.57% 500 W/48 V
Total 7600 W

S. OUATTARA ET AL. 754
Pp = S·cos(Φ), this implies that cos
p
SP(Φ) =
7600/0.86 = 8.53 KVA.
The standardized power nearest is 10 KVA. But in the
range of the generators of the Orange-Ci suppliers the 10
KVA are not equiped with automatic starting. This is
why we suggest a group of 12 KVA. To feed such a
group during six days we envisage a cistern of 500 liters.
The generator must be a silent group to prevent that this
one does not disturb by its noise.
 Evaluation of the autonomy of the batteries: The
quantity of electricity (Q) is:
QIt, now Q
PUIUt  thus UQ tP

, we
also know that:
1 Ah = 3600 C for a battery.
Four branches of battery provide:
Q = 4 × 160 × 4 × 3600 C = 9216000 C
The batteries supply only the equipment 48 V whose
required power was estimated at 3200 W. Thus:
48 9216000138240 38.41.58
3200
tshours days


 Choice of the generator: The selected generator is
that of SDMO company considering the robustness of
this one. It was several times used on the Orange-Ci
sites. This generator SDMO is of 12 KVA.
4.3.2.3. Study of the Environment
For earthing of the equipment, it will be installed a bar of
ground on one side of the truck. All earthings will con-
verge towards this bar of ground using green yellow ca-
bles or flat part for the descent lightning protector.
Thereafter the ground bar itself will be connected to the
ground stake by a naked cable, HFG cables. The ground
stake will have to be installed far from the place of in-
stallation of the equipment.
4.4. Bearing Support and Infrastructures
Solutions
It is question of defining the various infrastructures nec-
essary to the installation of the equipments of the radio
site. The study of radio design suggested a solution out-
door; it is a solution with a truck with leaves which is
retained.
It is question of using a truck with two side leaves.
This solution enables us to make safe the equipments
during their transport avoiding dust and the rain. We
envisage a space on the truck to shelter the generator and
the cistern of 500 L. For this, once on the place of de-
ployment, we open the two side leaves and the installa-
tions can then be done in an environment outdoor.
Finally this solution will be the solution which we adopt.
 Study of the antenna support: The various forms of
mediums generally used for the installation of anten-
nas GSM are:
 Stayed or self-stabilizing pylons
 Mast
 Use of a pylon: The use of a pylon in the deployment
of a mobile site does not prove suitable sight the size
of this one and time that it is necessary to build it. In
the same way the pylon requires many constraints
(solid mass, staying, etc.) for its installation. We can-
not thus use a pylon.
 Use of a mast: The Mast contrary to the pylon is
smaller and requires less requirements for its installa-
tion. It can easily be installed on a truck. We thus re-
tained a Mast for the support of antennas GSM. The
Mast to be conceived must have the following char-
acteristics:
 To be able to support three antennas panels of the
K742196 type.
 To be controlled by an automated system which en-
ables it to leave and to line up
We recommend a mast of 25 m height considering the
results the estimated height of the antennas obtained in
radio engineering.
4.5. Deployment Kit of the Event-Driven
Movable Radio Site
The list of the components of the kit of deployment of
the event-driven movable radio site is presented as fol-
lows:
 A truck with two side leaves.
 A BTS MBO1 or a distributed BTS according to the
availability
 6 × 30 m of coaxial cables “7/8” or optical fibers ac-
cording to the solution.
 Four rollers of cables
 A GPS receiver of any type
 A compass satellite of Metronic
 Wiltek 9103 satellite pointer
 The kit of VSAT station (Modem, parabola and ex-
ternal unit).
 Fuel to feed the group
 All accessories for earthing of the equipments
 A satellite portable of any type.
 A 12 KVA generator of SDMO type
 A cistern of 500 L of any type
 Energy cables of section 50 mm2
 Panels antennas of the K742196 type
 3 panels antenna bases
 3 rulers of mechanical tilt
 3 supports of arrangements of panels antennas
 3 rectifiers 3200 W/48 V + 4 branches of battery of

S. OUATTARA ET AL. 755
all type + 1 Emerson bay
 An inclinometer
 Hiring of the band of 1 MHz
5. Conclusions
This work enabled us to propose a kit for the deployment
of a movable radio site for opening or temporarily mak-
ing denser the Orange-Ci network during the significant
events in a given locality. We proceeded in a first under
investigation of the motionless radio sites which enabled
us to emphasize the various building blocks as well as
the various equipments used for their deployment. There-
after we conducted a study on various building blocks
within the framework of the deployment of a movable
radio site to lead to the proposal of a deployment kit of
the movable radio site.
In Perspective, this work can be directly exploited by
another GSM operator in Ivory Coast. We will write the
procedure for the deployment of the movable radio site
and its dismantling.
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