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ISSN 2348–2370
Vol.08,Issue.23,
December-2016,
Pages:4566-4574
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Study and Analyze WCDMA Cell Site Coverage Planning for the Case
of Hawassa City LAMESSA DINGETA
1, GELAYE GERESU
2, SALIVENDRA SUBRAHMANYA SASTRY
3
1HOD, Dept of ECE, Asossa University, Ethiopia, E-mail: [email protected].
2Dept of ECE, Asossa University, Ethiopia, E-mail: [email protected].
3Assistant Professor, Dept of ECE, Asossa University, Ethiopia, E-mail: [email protected].
Abstract: The main aim of the thesis is to study and
analyze WCDMA cell site coverage planning for the case
of Hawassa city. It is the intension of the work to
understand the different modeling approaches, input and
output parameters in WCDMA coverage dimensioning. In
cellular 3G network, there are sequential steps for radio
network planning. These steps start from simple analysis
to computer aided mathematical computation; i.e., from
nominal planning state to detail planning and then
optimization. In fact, the entire planning problem is
decomposed into three sub-problems: the cell site planning
subproblem, the access network planning sub problem and
the core network planning subproblem. Coverage estimation
is the critical step in RAN(Radio Access Network) planning,
specially for the system to be deployed. Nominal radio
network planning is done basically using link budget
calculation to estimate the cell size. In most cases,
since the simplicity of this stage is needed the coverage
estimation is done with a general propagation model which
doesn’t incorporate the actual geographical information
(terrain model). Thus, the major problem in the obtained
result is its closeness to the real coverage results. In order
to make this RAN planning stage more accurate, the
inclusion of the terrain model has to be considered in
simple manners, so that improvement in the result is
obtained while the simplicity of the process is still
maintained. In general, to resolve this problem proper
design of network planning is necessary.
Keywords: Hawassa, WCDMA, RAN, Sub Problem.
I. INTRODUCTION
3G refers to the 3rd generation of mobile telephony (that is
cellular) technology.The 3rd
generation as the name suggests,
follow two earlier generations. The 1st generation (1G)
began in the early 80’s with commercial development of
Advanced Mobile Phone Service (AMPS) cellular networks.
Early AMPS network used Frequency Division Multiple
Access (FDMA) to carry analog voice over channels in the
800MHZ frequency band. The 2nd
generation (2G) emerged
in the 90’s when mobile generators deployed two competing
digital voice standards. In the North America, some
operators adopted IS-95, which uses CDMA to multiplex up
to 64 calls per channel in the 800MHZ band. Across the
world, many operators adopted the Global System for
Mobile communication (GSM) standard, which used the
Time Division Multiple Access (TDMA) technique to
multiplex up to 8 calls per channel in the 900MHZ and
1800MHZ spectrum bands. The International Tele-
communication Union (ITU) defined the 3rd generation (3G)
of mobile telephony standards IMT-2000 to facilitate
growth, increase bandwidth and support more diverse
applications. Some of the limitations of 2G systems are; it’s
only voice oriented, it has limited data capabilities, no
worldwide (WW) roaming and incompatible system in
different countries. Despite the extension of 2G system i.e.
2.5G such as GPRS and EDGE, which provides the
enhanced facilities and much improved data rates, but there
are still incompatibility issues and WW-roaming problems.
Therefore, there is a need of a system that could provide
more advanced services. Some new requirements of the 3G
systems are:
Bit rates up to 2Mbps
Variable bit rate to offer bandwidth on demand
Multiplexing of services with different Qos
requirements on a single connection
Quality requirements from 10% frame error rate to 10-6
bit error rate.
Co-existence with different systems and inter-system
handovers for coverage enhancements and loading
balancing
Uplink and downlink asymmetry e.g. web browsing
causes more loading to downlink than to uplink.
High spectrum efficiency
Co-existence of FDD (Frequency Division Duplex) and
TDD (Time Division Duplex) modes
The target of any radio network operator is to minimize
the Capital Expenditure (CAPEX) of the equipment required
for an operational radio network. In turn, a lesser amount of
radio network equipment typically results in lower
Operational Expenditure (OPEX). From the technical point
of view, the radio interface planning process of a cellular
mobile communication system targets providing the required
network coverage, system capacity, and sufficient Quality of
Service (QoS) with minimum economic constraints. The
LAMESSA DINGETA, GELAYE GERESU, SALIVENDRA SUBRAHMANYA SASTRY
International Journal of Advanced Technology and Innovative Research
Volume. 08, IssueNo.23, December-2016, Pages: 4566-4574
radio access part of the network is considered of essential as
it is the direct physical radio connection between the Mobile
Station (MS) and the core part of the network. In order to
meet the requirements of the mobile services, the radio
network must offer sufficient coverage and capacity while
maintaining the lowest possible deployment costs. In order
to achieve these goals, a comprehensive coverage planning
has to be done. The key factors that would enhance the
coverage planning have been outlined. Some of them as
follow:
1. Coverage regions, area type information and
propagation conditions based on the data obtain from
the site survey, geographical site maps and
topographical information.
2. Statistical population of the area and the number of
prospective 3G users of the area and the demand for the
services
3. Estimations of the amount of 3G base stations (Node
B’s) with parameters such as:
The placement of the node B’s sites
The degree of vectorization used at the site
The number of receiving and transmitting antennas
used at the node B’s
The height of the node B antennas
The direction (azimuth) of the node B antennas
The down tilt of the node B antennas
Atoll 3G is the planning tool used in the design of the 3G
network initial coverage planning. Atoll 3G is a network
planning and analysis tool containing a complete range of
functionality for the design and simulation of GSM, AMPS,
TDMA, TACS, UMTS, W-CDMA, CDMA2000, EV-DO,
TD-SCDMA and WiMAX networks. Its functionality
includes hierarchical network planning, propagation
modeling, service definition, analysis arrays, neighbor list
definition, automatic frequency planning, CW data analysis,
detailed reporting and simulation of network performance.
II. UNIVERSAL MOBILE TELECOMMUNICATIONS
SERVICE (UMTS)
Universal Mobile Telecommunications Service (UMTS)
represents an evolution of Global System for Mobile
communications (GSM) to support third generation(3G)
capabilities. The rapid increase in the demand for data
services, primarily IP, has been thrust upon the wireless
industry. Over the years there has been much anticipation of
the onslaught of data services, but the radio access platforms
have been the inhibitor from making this a reality. Third
generation (3G) is a term that has received and continues to
receive much attention as the enabler for high-speed data for
the wireless mobility market. 3G and all it is meant to be are
defined in the ITU specification International Mobile
Telecommunications-2000(IMT-2000). IMT-2000 is a radio
and network access specification defining several methods or
technology platforms that meet the overall goals of the
specification. The IMT-2000 specification is meant to be a
unifying specification, enabling mobile and some fixed high
speed data services to use one or several radio channels with
fixed network platforms for delivering the services
envisioned:
Global standard
Compatibility of service within IMT-2000 and other
fixed networks
High quality
Worldwide common frequency band
Small terminals for worldwide use
Worldwide roaming capability
Multimedia application services and terminals
Improved spectrum efficiency
Flexibility for evolution to the next generation of
wireless systems
High-speed packet data rates
2 Mbps for fixed environment
384 Mbps for pedestrian
144 Kbps for vehicular traffic
The definition of what exactly 3G encompasses is
usually clouded in marketing terms, with the technical reader
desiring a straightforward answer. The reason 3G is hard to
pin down is primarily due to the fact that it involves radio
access and network platforms that do not exist right now.
The standard that everyone is striving for is IMT-2000 and it
incorporates several competing radio access platforms,
which will not achieve harmonization, if ever, until 4G or
beyond. The radio access platforms that comprise the IMT-
2000 specification are all different and it should be no
wonder that it is difficult to obtain a simple answer when
asked to describe what a 3G system will look like.
IMT2000/3G can be described as:
Being used to reference a multitude of technologies
covering many frequency bands, channel bandwidths,
and, of course, modulation formats.
No single 3G-infrastructure platform, technology, or
application exists.
3G is applied to mobile and stationary wireless
applications involving high-speed data. IMT-2000
mandates data speeds of 144 Kbps at driving speeds,
384 Kbps for outside stationary use or walking speeds,
and 2 Mbps for indoors.
Coupled with the different platforms that comprise the
IMT-2000 standard is the issue that the existing 1G/2G
platforms need to transition into the 3G arena. The transition
method that an operator must select and spend currency on
is, of course, a difficult decision and will determine how
successful the wireless operator will be in the future. The
interim platform that bridges the 2G systems into a 3G
environment is referred to as 2.5G. 3G is a mobile radio and
network access scheme that enables high-speed data to be
utilized, allowing for true multimedia capabilities in a
mobile wireless system. Presently, voice has been the
primary wireless application with the use of the short
message service (SMS) being the largest packet data service.
Today’s wireless cellular and personal communications
services (PCS) systems have the same radio bandwidth
allocated for both voice and data. Some of the 2.5G
Study and Analyze WCDMA Cell Site Coverage Planning for the Case of Hawassa City
International Journal of Advanced Technology and Innovative Research
Volume. 08, IssueNo.23, December-2016, Pages: 4566-4574
transition or migration plans call for the use of a dedicated
spectrum just for data applications. The IMT 2000 specifies
that data speeds of 144 Kbps for vehicular, 384K for
pedestrian and 2 Mbps for indoor applications are the desired
goals and have been built into the specifications.
A. Migration Path to UMTS and the Third Generation
Partnership Project (3GPP)
The radio access for UMTS is known as Universal
Terrestrial Radio Access (UTRA). This is a WCDMA-based
radio solution, which includes both FDD and TDD modes.
The radio access network (RAN) is known as UTRAN. It
takes more than an air interface or an access network to
make a complete system, however. The core network must
also be considered. Because of the widespread deployment
and success of Global System for Mobile Communications
(GSM), it is appropriate to base the UMTS core network
upon an evolution of the GSM core network. In fact, as we
shall see, the initial release of UMTS (3GPP Release 1999)
makes use of the same core network architecture as defined
for GSM/GPRS, albeit with some enhancements. Moreover,
the core network is required to support both UMTS and
GSM radio access networks (that is, both UTRAN and the
GSM BSS). The evolution of the GSM BSS has not stopped,
however. As we shall see, enhancements such as the
Enhanced Data Rates for Global Evolution (EDGE) have
been made. With the requirements for the continued
evolution of GSM and for the GSM to meet UMTS
requirements, it makes sense for the continued maintenance
and evolution of GSM specifications to be undertaken by
3GPP. Consequently, 3GPP, rather than ETSI, is now
responsible for GSM specifications as well as UMTS-
specific specifications. For several years, the various
enhancements to GSM have been developed according to
yearly releases.
Thus, for a given GSM specification, versions have been
related to Release 1996, Release 1997, and Release 1998.
Initially, 3GPP determined to continue with that approach.
Therefore, the first release of specifications from 3GPP is
known as 3GPP Release 1999. The release includes not only
new specifications for the support of a UTRAN access, but
also enhanced versions of existing GSM specifications (such
as for the support of EDGE). The 3GPP Release 1999
specifications were completed in March of 2000. These, of
course, will be subject to some revisions and corrections as
errors and inconsistencies are discovered during test and
deployment. The next release of 3GPP specifications was
originally termed 3GPP Release 2000. This included major
changes to the core network. The changes were so
significant, however, that they could not all be handled in a
single step. Thus, Release 2000 was divided into two
releases: Release 4 and Release 5. Going forward, the
concept of yearly releases will no longer apply, and releases
will be structured and timed according to defined
functionality. The Release 4 specifications were frozen in the
first half of 2001. This means that no new content is to be
added and any changes to the specifications will occur only
to correct errors or inconsistencies.
For Release 5, it is expected that specifications will be
frozen in December of 2001. For the most part (although not
exclusively), 3GPP Release 1999 focuses mainly on the
access network (including a totally new air interface) and the
changes needed to the core network to support that access
network. Release 4 focuses more on changes to the
architecture of the core network. Release 5 introduces a new
call model, which means changes to user terminals, changes
to the core network, and some changes to the access network
(although the fundamentals of the air interface remain the
same). Given that the air interface is new in Release 1999
and that it does not drastically change in later releases, it is
best to begin our description of UMTS technology with the
WCDMA air interface. The primary focus in this book will
be on the FDD mode of operation, with less emphasis on
TDD. First, however, a few words about the types of
services that UMTS can offer.
III. SIMULATION ANALYSIS AND RESULTS
Simulation is a practical and scientific approach to
analyze a complex system. In this thesis, simulation is used
to investigate the RAN coverage nominal planning of
WCDMA networks as it is done using Atoll simulation
environment. In most cases, the radio link budget calculation
can simply be done be using Excel for its simplicity.
However, in this thesis Atoll was chosen as simulation
environment for its in-depth input analysis and flexible
working environment.
A. Simulation Flow
The simulation is intended to carry out the link budget
calculation, propagation modeling using the terrain model
and coverage estimation. The planning was performed in
clear manner to understand the input and output factors for
coverage evaluation. Fig.3.1 shows the structure and flow of
the simulation for coverage and evaluation. It will be
discussed in the upcoming sections as to how the coverage
planning is done; what factors do mainly affect the coverage
estimation; and how the result are affected with the
consideration of real-environment information of the
deployment area.
Fig.1. Simulation Flow for WCDMA
LAMESSA DINGETA, GELAYE GERESU, SALIVENDRA SUBRAHMANYA SASTRY
International Journal of Advanced Technology and Innovative Research
Volume. 08, IssueNo.23, December-2016, Pages: 4566-4574
B. Environmental Loading
The process of environmental loading is to identify the
dif factors that directly or indirectly affect the radio list out
them as planning parameters. As this thesis being ac
considered to be.
1. Deployment Area Selection
Hawassa is one of the nine regional states of the It is one
of the federal state of the country with RAN Coverage
Planning different environmental network planning process
and as well to case study, Hawassa was Federal Democratic
Republic of Ethiopia medium population and technological
advancements. The increase in population expands the city it
requiring new and improved years master plan of Ethio-
Telecom published in 2005, the growth of expected to be
outstanding and might needs the doubled network infract the
planned to improve when we come to this thesis, due to its
location and inclusive business and residential cellular
subscribers central specific 46.6 Km2 areas is taken as the
selected deployment area. The area extends up to Tikur
Wuha to the north, to the east and Hawassa lake to the
center. The area is graphically presented in Fig2
Fig.2. Selected Deployment Area [www.googlemaps.com]
Neither the population nor the exact number of mobile
subscribers data is available; however, as is can be seen from
the Excel document in Appendix I, more than 30 GSM-
cellular network antennas (base station antennas) do exist in
the selected area.
2. Environmental Parameter Collection
One of the objective of this thesis is to show how simply
the real environment data can be incorporated in the early
stage of the RAN coverage planning (i.e., in nominal
planning) to improve the planning process and the obtained
results from the start. Thus, in this thesis the actual terrain
model of the deployment area has been considered to
estimate the cell site radius in the nominal RAN coverage
planning stage without the loss of simplicity of the planning.
The improvement obtained in considering the terrain model
information will be explicitly seen in the result with proper
propagation model selection there are different types of
information that can be digitized and used for coverage
predictions. The most important from the network planning
point of view are topography (terrain heights), clutter (area
types) and roads traffic density. For the micro cell modeling,
which is required in a urban environment, more information
and heighten resolution maps should be used. Information
about the buildings and streets is essential, so the pixel size
from 5m to 25m is reasonable. The streets can be stored and
used in vector format. All of this information is included in
the digital map database.
C. Coverage planning
1. Coverage Input Parameters
The coverage planning simulation is designed in accordance
with RAN planning procedures. As it can be seen earlier,
environment loading is done prior to coverage planning. The
intermediate calculations and detailed formulas regarding
deployment area selection and environmental parameter
collection are also done prior to this part for the user of
coverage planning. Furthermore, additional parameters
required for coverage planning such as acceptable
transmission power, the minimum recoverable power and
acceptable losses have to be defined in advance. To help for
assessment, the parameters used in link budget calculation
such as the transmitter power, the acceptable receiver
sensitivity and the transmitter and receiver losses and
antenna gains were obtained from [5]. The difference comes
when propagation is modeled, since in our case the
propagation modeling is incorporated with the actual terrain.
TABLE I. Coverage Parameters
2. Radio Link Budget Calculation, Propagation Modeling
and Coverage Estimation
The coverage planning was started through the link
budget. As stated earlier, Radio Link budget refers to the
calculation of the gains and losses in the communication
link; namely, to calculate the maximum propagation loss
allowed by the link in a call connection and under the
circumstance of quality calls. It is calculated for a single
mobile user transmitting at maximum power in a network
with only a single cell even though attempts were made to
factor into the link budget the existence of other cells and
their impact in terms of interference margin The radio link
budget calculation is known to be vendor specific (not area
explicit) where input parameters such as transmission power,
receiver power sensitivity, transmitter and receiver antenna
gain, and transmitter system losses are selected based on
which vendor equipment is used. In our case, as it has been
said before, the values are selected from those that were used
in [5]. The radio link budget is calculated from both the
Study and Analyze WCDMA Cell Site Coverage Planning for the Case of Hawassa City
International Journal of Advanced Technology and Innovative Research
Volume. 08, IssueNo.23, December-2016, Pages: 4566-4574
uplink and downlink coverage criterion based on this
criterion, the maximum path loss faced by the user with the
minimum signal quality.
TABLE II. Link Budget Calculation
After the maximum allowable path loss is calculated, the
next step will be to determine the eNB coverage range by
combining it with the propagation model.
TABLE III. Parameters for the Propagation Modeling.
Parameter in Table II is and Table III are imported or
exported from Atoll simulation software accordingly
describing the link budget parameters and calculations for
the coverage prediction of the 2100 MHz 3G WCDMA
system.
Fig.3. Selected Computational Area
Using the parameters in TableII and TableIII the propagation
was calculated at every 100 meters incrementally for every
θ° azimuths angle to compromise the computational time and
the obtained results. As the propagation calculation distance
increase more and more general were as calculating the
propagation loss for every meter increases the computation
time. The minimum Building height, street width and
building to building distance were taken as averages within
the high building were faced. The usual assumption in many
LAMESSA DINGETA, GELAYE GERESU, SALIVENDRA SUBRAHMANYA SASTRY
International Journal of Advanced Technology and Innovative Research
Volume. 08, IssueNo.23, December-2016, Pages: 4566-4574
RAN planning that the deployment area has uniform
building height throughout the entire deployment area was
customized for 100m or up to very high building was faced.
3. Node Bs Positions and Justification of Their
Deployment in the Locations BTS 0
BTS 0 was placed around Hawassa old stadium (380 28'
30.58", 70 2'17.74"N). The area was considered to be
medium populated area Three sectors antenna was used, to
provide required coverage. A total of -73.05dBm received
power level and -6.68dB Ec/I0 was recorded 600m away
from the base station. While along the southern bypass road
an average received power of -79.85dBm and Ec/Io of -
4.15dB at approximately 1km away from the BTS was
recorded. This is a strong signal compared to the threshold of
-120dBm to maintain call while driving on a motor way.
There was Fresnel clearance, the elevation of the area is
almost similar averagely 1715m.
BTS 1: Three sectors antenna was placed along (380
29' 22”E, 70 1' 25.24N) the details of the antenna can
be found in appendix B the expected population and
traffic load is medium and therefore, three sector
antenna was chosen to provide foot print of the network
service. There was a clear Fresnel clearance, no hill,
vegetation cover or propagation absorption materials in
the area and therefore, an average received power level
of -80.11dBm was recorded with Ec/I0 (dB) of -7.66dB
at 1km distance from each sectors.
BTS 2: This Node B is situated close to BTS no 6 and
4 just about 0.99km apart at a coordinates of
(38029'42.12"E, 702'57.46"N) down the town center
around manahria to increase the coverage and capacity
of the area. Due to commercial activities of the area and
moving vehicles the antenna was sectaries.
BTS 3: The Node B was placed at (38029'12.25"E,
704'37.83"N) with three sectors to provide coverage to
the residential area along the bypass road to Addis
Ababa, the other sector provide coverage to the eastern
part with average receiver sensitivity of -74.7dBm and -
7.03 Ec/Io.
BTS 4: This was placed at (380 30'20.95"E,
702'12.69"E) due to some academic and big office
centers such as Hawassa University and Regional
council, the area has a medium population traffic load
and an average of 1740m elevation. Therefore, three
sector antenna was chosen to provide coverage for
those mentioned centers including residential. Two
sectors was pointing the eastern bypass road to provide
coverage along the motor way. An average received
power of -74.67dBm and Ec/Io of -6.63dB was
recorded at distance of 600m from each sectors.
BTS 5: Three sectors antennas were placed at
(38029'57.57"E, 703'58.63"N) to provide coverage to
Hawassa mini airport along the main bypass road. The
area is sparsely populated relative to other areas. It also
gives coverage to residential in the area.
BTS 6: The antenna was placed at(380 28' 40"E, 70 3'
20.64"N) Piassa around Arab safer nearby the city's big
market. This is the city centre with a densely
population and expected high load or traffic at the peak
hours. The range of the signal is not long as compared
to the three sectors antenna and therefore, an average
received signal of -79.27dBm was recorded at an
average distance of 600m from each sectors and there
was a Fresnel clearance due to building infrastructure
and high traffic. The area elevation is about 1700m.
4. Coverage Prediction by using Signal Level
Fig.4. Coverage Prediction by Using Signal Level >= -80
dBm.
Fig.5. Coverage Prediction by Signal Level >= -90dBm.
As we can see from Fig.4, by using seven eNBs are used
to cover the selected deployment area, which shows an
outstanding variation compared to the existing GSM cellular
network in the area. Without doubt there still is variation in
transmission power, the difference in central frequency, and
technological advancements which puts UMTS WCDMA in
higher advantage than GSM. However covering a certain
area with only 20 base stations area tell us that the previous
network needs proper assessment., equation 4.19 only seven
eNBs are used to cover area, which shows an outstanding
variation compared to the SM Without doubt there still is
variation in seven eNBs which were previously covered by
more than i.e., without including the CDMA cellular
network in the coverage planning was done improperly and
Study and Analyze WCDMA Cell Site Coverage Planning for the Case of Hawassa City
International Journal of Advanced Technology and Innovative Research
Volume. 08, IssueNo.23, December-2016, Pages: 4566-4574
the existing needs proper assessment. The below Fig..5
shows maximum possible area that can be covered by signal
of level >=-90dBm, it's also shown that the required target
area can almost be covered by using a given signal level.
Similarly, five different signal levels including the one
mentioned above and maximum possible area of each signal
are shown by using histogram in the Fig..6 below
Fig.6. Coverage and Area Prediction by Using Different
Signal Level
The result shown in Fig.6 above shows the statistical
relation between different signal levels and maximum area
that can be covered by each signal level. As we can see from
the from the histogram in the figure out of 46.4km2 total
computational area, 23.8km2 is covered by the strongest
signal >= -80dBm or in other word, it can cover up to
54.49% of the total area. The rest are shown accordingly in
the table below
TABLE IV. % of Area for Five Different Signal Level
5. Coverage Analysis
A real time point analysis of a user at a random instant
position specifically at (38029'22.03"E, 703'32.12"N) shown
in the Fig.7 below
Fig.7. Real Time Coverage Analysis of Receiver at
(38029'22.03"E, 703'32.12"N).
Fig.8. Expected Received Signal Strength and Best
Server Node B of Fig7.
A blue ellipsoid shown in the Fig..9 below indicates the
Fresnel zone between the transmitter and the receiver, with a
green line indicating the line of sight (LOS). Atoll displays
the angle of the LOS read from the vertical antenna pattern.
Along the profile, if the signal meets an obstacle, this causes
attenuation with diffraction displayed by a red vertical line
(if the propagation model used takes diffraction mechanisms
into account). The main peak is the one that intersects the
most with the Fresnel ellipsoid zone. The total attenuation
and other important parameters are displayed above the main
peak. A point-to-point analysis between a user located in the
Fig.7 above and three sectored best server node B(site2_3)
located at (Longitude:38029'42.12E, Latitude :7025'746"N).
shows Fresnel clearance to the point 1230m away with
maximum path loss of 156.54 dB, 4.7dB shadowing margin,
-112dBm signal strength and tolerable LOS(Line of sight)
clearance as shown in the figure 9 below.
LAMESSA DINGETA, GELAYE GERESU, SALIVENDRA SUBRAHMANYA SASTRY
International Journal of Advanced Technology and Innovative Research
Volume. 08, IssueNo.23, December-2016, Pages: 4566-4574
Fig.9. Receiver Profile Analysis and Result
Fig.10.
The result shown in the Fig.3.9 above also shows, the
outdoor coverage with indication of some areas with low
pilot power which is still within the acceptable re range of -
113.05 dBm to keep the call. The detail analysis result of the
user at 50km/hr is shown in Fig.11 below
Fig.11. Detail Analysis Result of the User at 50km/hr
IV. CONCLUSIONS AND RECOMMENDATIONS
A. Conclusions
Network coverage planning is essential part of 3G
networks, in this thesis, 3G WCDMA nominal coverage
planning for Hawassa city was designed and analyzed based
on the signal level and transmitter power. Performances of
these parameters are studied for different scenario to achieve
good coverage. As it has been said over and over in this
thesis, the nominal coverage planning was done with the
consideration of the environments data. So far, nominal
coverage is done with simple considerations and
experimentally defined propagation models such as Okumara
Hata and COST 321 Hata. Such models define a certain area
type like urban, sub-urban and rural with a single correction
factor. However, the definition of area type by itself varies
from place to place which bring different estimations in
coverage. For instance, Hawassa can be considered as
suburban or small city compared to other city, in such case
different correction factors of the propagation model can
surly affect the coverage estimation. Apart from small
discrepancies observed, the deployed coverage provides very
good coverage with very good defined boundaries. Due to
the different terrain in different areas the percentage
coverage of individual Node B varies. However, It was
found the network coverage and signal strength decreases as
the distance increase. It was also found out that only 7
NodeBs are necessary for the network to be deployed in the
selected area to have a better coverage as compared to that of
existing GSM cellular network which comprise of more than
20 NodeBs with in the same area.
B. Recommendations
Improvements are being undertaken such as upgrading
the existing network to 3G cellular networks by Ethio-
Telecom to achieve the sited goals. The challenge is
therefore to properly design the upgrading to improve the
quality of service or event to properly optimize the existing
network. The overall radio network planning and
implementing of UMTS-WCDMA has to be done first by
performing in-depth assessment of the existing cellular
network. After that, planning of the new WCDMA network
has to be done with proper optimization of the current
topology and the expected quality. It has to be planned to
efficiently minimize both the initial investment cost and as
well as operational cost to the deployment of WCDMA.
V. REFERENCES
[1]Rappaport, T.S., Wireless communications - principles
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[2]Pirkul, H., Schilling, D.A., The maximal Covering
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[3]Penttinen, Jyrki T.J. Radio Network Planning and
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[4]Antti, T. and Holma, H. (eds.) (2004). WCDMA FOR
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[5]WCDMA-UMTS deployment handbook planning and
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[6]Cell Planning in WCDMA Networks for Service Specific
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[7]Tran-Gia, P., Leibnitz, K., Tutschku, K., Teletraffic issues
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[8]Radio planning and coverage optimization of 3G cellular
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Study and Analyze WCDMA Cell Site Coverage Planning for the Case of Hawassa City
International Journal of Advanced Technology and Innovative Research
Volume. 08, IssueNo.23, December-2016, Pages: 4566-4574
Control and Algorithms, IEEE Transactions on Wireless
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[10] GSM Planning Workshop student text en/lzt 123 3315
R3B, Ericsson.
[11]Fundamentals of Cellular Network Planning and
Optimization 2G/2.5G/3G. Evolution to 4G by Author: Ajay
R. Mishra
[12]“Implementation of New Cell Site in Telecom Sector“
by Amita Sharma1(M.Tech, UIET, KUK) and UIET,
Monish Gupta2 (Assistant Professor, UIET, KUK).