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www.ijatir.org ISSN 23482370 Vol.08,Issue.23, December-2016, Pages:4566-4574 Copyright @ 2016 IJATIR. All rights reserved. Study and Analyze WCDMA Cell Site Coverage Planning for the Case of Hawassa City LAMESSA DINGETA 1 , GELAYE GERESU 2 , SALIVENDRA SUBRAHMANYA SASTRY 3 1 HOD, Dept of ECE, Asossa University, Ethiopia, E-mail: [email protected]. 2 Dept of ECE, Asossa University, Ethiopia, E-mail: [email protected]. 3 Assistant 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 3 rd 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 2 nd 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
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Page 1: Study and Analyze WCDMA Cell Site Coverage Planning for ... · PDF fileoutput parameters in WCDMA coverage dimensioning. In cellular 3G network, ... network planning is done basically

www.ijatir.org

ISSN 2348–2370

Vol.08,Issue.23,

December-2016,

Pages:4566-4574

Copyright @ 2016 IJATIR. All rights reserved.

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

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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

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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

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

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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

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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

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

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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

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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

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.

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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

and practice, 2nd edition. Prentice- Hall; Upper Saddle

River, 2002.

[2]Pirkul, H., Schilling, D.A., The maximal Covering

Location Problem with capacities on total workload,

Management Science 1991;37(2), 233-248.

[3]Penttinen, Jyrki T.J. Radio Network Planning and

Optimization for UMTS Second Edition

[4]Antti, T. and Holma, H. (eds.) (2004). WCDMA FOR

UMTS: Radio Access for Third Generation Mobile

Communication. (3rd edition). West Sussex: Wiley Ltd.

[5]WCDMA-UMTS deployment handbook planning and

optimization aspects. United Kingdom : John Wiley & Sons,

Jan. 2006.

[6]Cell Planning in WCDMA Networks for Service Specific

Coverage and Load Balancing by Chae Y. Lee and Hyun M.

Shin

[7]Tran-Gia, P., Leibnitz, K., Tutschku, K., Teletraffic issues

in Mobile Communication Network Planning, Proceedings

of eleventh ITC Specialist Seminar on Multimedia and

Nomadic Communications 1998, 27-29.

[8]Radio planning and coverage optimization of 3G cellular

networks Edoardo Amaldi· Antonio Capone · Federico

Malucelli

[9]Amaldi, E., Capone, A., Malucelli, F., Planning UMTS

Base Station Location: Optimization Models with Power

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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

Communication 2003; 2(5), 939-952.

[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).