ABSTRACT

This report is based on the study of wireless communication.

Wireless communication provides mobility. TDMA, FDMA, CDMA are the various multiple access techniques. There are several

network generations which evolved during the years.

The development of GSM started in 1982, when the Conference of European Posts and Telegraphs (CEPT) formed a study group

called Groupe Spécial Mobile (the initial meaning of GSM). The group was to study and develop a pan-European public cellular

system in the 900 MHz range, using spectrum that had been previously allocated.

GSM, the Global System for Mobile communications, is a digital cellular communications system which has rapidly gained

acceptance and market share worldwide, although it was initially developed in a European context. In addition to digital transmission,

GSM incorporates many advanced services and features, including ISDN compatibility and worldwide roaming in other GSM

networks. The advanced services and architecture of GSM have made it a model for future third-generation cellular systems, such as

UMTS.

The objective to develop this 2G standard is to resolve the roaming problem in the six existing different 1G analog cellular systems in

Europe. The global system for mobile communications (GSM) is a set of recommendations and specifications for a digital cellular

telephone network. These recommendations ensure the compatibility of equipment from different GSM manufacturers, and

interconnectivity between different administrations, including operations across international boundaries.In 1982, frequency bands of

890-915 MHz and 935-960 MHz were allocated for Pan European Public land Mobile Network (PLMN), and GSM was formed.

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Chapter 1

INTRODUCTION

Why Wireless Communication?

The popularity of wireless communication is due to the fact that it provides mobility. Mobility can be of two types:-

User Mobility: In this the user is mobile but not the devices. This means that user is not accessing the same

telecommunication service all the time in motion. Example, a user is accessing the internet using his same account from

different locations.

Device portability: In this the device moves. This means that user is accessing the telecommunication services all the time in

motion. Example, a mobile phone system.

All the communication devices exhibit one of the following:

Fixed and wired: Device is fixed and communication medium is wired. Example, typical desktop computer.

Fixed and wireless: Device is fixed but communication medium is wireless. Example, desktop computers with wireless

connections.

Mobile and wired: Device is mobile but communication medium is wired. Example, laptops.

Mobile and wireless: Device is mobile and communication medium is wireless. Example, mobile phone systems.

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1.1 HISTORY OF WIRELESS COMMUNICATION

The origin of mobile communication followed quickly behind the invention of radio in the late 1880s. The first application of mobile

radio was related to the navigation and safety of ships at sea. As radio concepts developed so did its use as a communication tool.

Frequency Division Multiple Access

Each Frequency Division Multiple Access (FDMA) subscriber is using the same medium (air) for communicating but they are assigned a specific

frequency channel. While they are using the frequency channel, no one else in that cell or neighboring cell can use the frequency channel. In

current analog cell systems, each channel is 30 kHz. When a FDMA cell phone establishes a call, it reserves the frequency channel for the entire

duration of the call. The voice data is modulated into this channel’s frequency band (using frequency modulation) and sent over the airwaves. At

the receiver, the information is recovered using a band-pass filter. The phone uses a common digital control channel to acquire channels.

FDMA systems are the least efficient cellular system since each analog channel can only be used by one user at a time. Not only are these channels

larger than necessary given modern digital voice compression, but they are also wasted whenever there is silence during the cell phone

conversation. Analog signals are also especially susceptible to noise – and there is no way to filter it out. Given the nature of the signal, analog cell

phones must use higher power (between 1 and 3 watts) to get acceptable call quality. Given these shortcomings, it is easy to see why FDMA is

being replaced by newer digital techniques.

Time Division Multiple Access

Time Division Multiple Access (TDMA) subscribers share a common frequency channel but use the channel only for a short time.

They are each given a time slot and allowed to transmit only during that time slot. When all the available time slots in a given

frequency are used the next user must be assigned to a time slot on another frequency.

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TDMA builds on FDMA by dividing conversations by frequency and time. Since digital compression allows voice to be sent at well

under 10 kilobits per second (equivalent to 10 kHz), TDMA fits three digital conversations into a FDMA channel (this is 30 kHz).

Code Division Multiple Access

Code Division Multiple Access (CDMA) subscribers share a common frequency channel. All users are on the same frequency at the

same time, they are divided however by codes. CDMA systems have no channels, but instead encode each call as a coded sequence

across the entire frequency spectrum. Each conversation is modulated, in the digital domain, with a unique code (called a pseudo-noise

code) that makes it distinguishable from the other calls in the frequency spectrum. Theoretically CDMA provides many times the

channel capacity of TDMA. Proponents of CDMA also claim that there are fewer dropped calls when crossing cell boundaries.

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Chapter 2

GSM NETWORK CONCEPT

The Global System for Mobile Communications (GSM) is a set of recommendations and specifications for a digital cellular

telephone network (known as a Public Land Mobile Network, or PLMN) GSM networks are digital and can cater for high system

capacities

They are consistent with the world-wide digitization of the telephone network, and are an extension of the Integrated Services

Digital Network (ISDN), using a digital radio interface between the cellular network and the mobile subscriber equipment.

GSM FREQUENCIES

GSM systems use radio frequencies between 890-915 MHz for receiveand between 935-960 MHz for transmit.

RF carriers are spaced every 200 kHz, allowing a total of 124 carriers for use.

An RF carrier is a pair of radio frequencies, one used in each direction.

Transmit and receive frequencies are always separated by 45 MHz.

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Extended GSM (EGSM)

EGSM has 10MHz of bandwidth on both transmit and receive.

Receive bandwidth is from 880 MHz to 890 MHz.

Transmit bandwidth is from 925 MHz to 935 MHz.

Total RF carriers in EGSM is 50.

Figure 2.1 Uplink and downlink

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2.1 Channel Concept

Figure 2.2 Channel Concept

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2.1.1 Signaling Channel

These are the main types of signaling Channels:

Broadcast Channels (BCH) - Transmitted by the BTS to the MS. This channel carries system parameters needed to identify the

network, synchronize time and frequency with the network, and gain access to the network.

Common Control Channels (CCH) - Used for signaling between the BTS and the MS and to request and grant access to the

network.

Standalone Dedicated Control Channels (SDCCH) - Used for call setup.

Associated Control Channels (ACCH) - Used for signaling associated with calls and call-setup. An ACCH is always allocated in

conjunction with a TCH or SDCCH.The above categories can be divided into the following logical channels:

Broadcast Channels (BCH)

Broadcast Control Channel (BCCH)

Frequency Correction Channel (FCCH)

Synchronization Channel (SCH)

Cell Broadcast Channel (CBCH)

Common Control Channels (CCCH)

Paging Channel (PCH)

Random Access Channel (RACH)

Access Grant Channel (AGCH)

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Dedicated Control Channel (DCCH)

Standalone Dedicated Control Channel (SDCCH)

Fast Associated Control Channel (FACCH)

Slow Associated Control Channel (SACCH)

Figure 2.3 Downlink

Figure 2.3 Uplink

2.1.2 Traffic Channel

Traffic Channels are used to carry two types of information to and from the user:

Encoded Speech

Data

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There are two basic types of Encoded Speech channel

Encoded Speech - Encoded speech is voice audio that is converted into digital form and compressed.

Full Rate Speech TCH (TCH/FS) - 13 kb/s

  Half Rate Speech TCH (TCH/HS) - 5.6 kb/s

Data - Data refers to user data such as text messages, picture messages, internet browsing, etc. It includes pretty much everything

except speech.

Full rate Data TCH (TCH/F14.1) - 14.4 kb/s

 Full rate Data TCH (TCH/F9.6) - 9.6 kb/s

 Full rate Data TCH (TCH/F4.8) - 4.8 kb/s

 Half rate Data TCH (TCH/F4.8) - 4.8 kb/s

 Full rate Data TCH (TCH/F2.4) - ≤2.4 kb/s

 Half rate Data TCH (TCH/H2.4) - ≤2.4 kb/s

Figure 2.4: Full Rate Traffic Channel (TCH/FS)

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Figure 2.5: Half Rate Traffic Channel (TCH/HS)

2.2 Frequency Hopping

There are two types of frequency hopping method available for the BTS: synthesizer hopping and baseband hopping.

Synthesizer Hopping - This requires the TRX itself to change frequencies according to the hopping sequence. So, one TRX would

hop between multiple frequencies on the same sequence that the MS is required to.

Baseband Hopping - In this method there are several TRX and each one stays on a fixed frequency within the hopping frequency

plan. Each TRX would be assigned a single time slot within a TDMA frame. For example, time slot 1 might be assigned to TRX 2 in

one TDMA frame and in the next TDMA frame it would be assigned to TRX 3, and the next frame would be TRX 3. So, the data on

each time slot would be sent on a different frequency each frame, but the TRXs on the BTS do not need to change frequency. The

BTS simply routes the data to the appropriate TRX, and the MS knows which TRX to be on for any given TDMA frame.

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GSM ARCHITECTURE

2.3 Base Station Subsystem (BSS)

To understand the paging process, we must analyse the functions of the BSS.

The Base Station Subsystem consists of the following elements:

BSC Base Station Controller

BTS Base Transceiver Station

TC Transcoder

The Base Station Controller (BSC) is the central network element of the BSS and it controls the radio network. This means that the

main responsibilities of the BSC are: Connection establishment between MS and NSS, Mobility management, Statistical raw data

collection, Air and A interface signalling support.

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Figure 2.7: GSM Architecture

The Base Transceiver Station (BTS) is a network element maintaining the Air interface. It takes care of Air interface signalling, Air

interface ciphering and speech processing. In this context, speech processing refers to all the functions the BTS performs in order to

guarantee an error-free connection between the MS and the BTS.

The TransCoder (TC) is a BSS element taking care of speech transcoding, i.e. it is capable of converting speech from one digital

coding format to another and vice versa. We will describe more about the transcoder functions later.

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Figure2.8: The Base Station Subsystem(BSS)

The BTS, BSC and TC together form the Base Station Subsystem (BSS) which is a part of the GSM network taking care of the

following major functions:

Radio Path Control

In the GSM network, the Base Station Subsystem (BSS) is the part of the network taking care of Radio Resources, i.e. radio channel

allocation and quality of the radio connection. For this purpose, the GSM Technical Specifications define about 120 different

parameters for each BTS. These parameters define exactly what kind of BTS is in question and how MSs may "see" the network when

moving in this BTS area. The BTS parameters handle the following major items: what kind of handovers (when and why), paging

organization, radio power level control and BTS identification.

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BTS

TCBSC

BSC

TCBTS

BTS

BTS and TC Control

Inside the BSS, all the BTSs and TCs are connected to the BSC(s). The BSC maintains the BTSs. In other words, the BSC is capable

of separating (barring) a BTS from the network and collecting alarm information. Transcoders are also maintained by the BSC, i.e. the

BSC collects alarms related to the Transcoders.

Synchronization

The BSS uses hierarchical synchronization which means that the MSC synchronizes the BSC and the BSC further synchronizes the

BTSs associated with that particular BSC. Inside the BSS, synchronization is controlled by the BSC. Synchronization is a critical issue

in the GSM network due to the nature of the information transferred. If the synchronization chain is not working correctly, calls may

be cut or the call quality may not be the best possible. Ultimately, it may even be impossible to establish a call.

Connection Establishment between MS and NSS

The BSS is located between two interfaces, the Air and the A interface. From the call establishment point of view, the MS must have

a connection through these two interfaces before a call can be established.

Collection of Statistical Data

The BSS collects a lot of short-term statistical data that is further sent to the NMS for post processing purposes. By using the tools

located in the NMS the operator is able to create statistical "views" and thus observe the network quality.

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A Base Station Subsystem is controlled by an MSC. Typically, one MSC contains several BSSs. A BSS itself may cover a

considerably large geographical area consisting of many cells. (A cell refers to an area covered by one or more frequency resources).

Each cell is identified by an identification number called Cell Global Identity (CGI) which comprises the following elements:

CGI = MCC + MNC + LAC + CI

MCC Mobile Country Code

MNC Mobile Network Code

LAC Location Area Code

CI Cell Identity

There is one 2Mbit/s PCM line reserved for each BTS to provide the connection to NSS. But as you can see, the BTS’s are used at

different times and on different days. Why not use the same line for both of the two BTSs? It can be done, but in this case there has to

be a concentrator between MSC and BTS. The BSC acts as a concentrator (in addition to being the radio network controller). One

BSC is capable of serving several BTSs.

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Chapter 3

Call Setup

3.1 A Mobile Terminated Call and Paging

Figure 3.1 : Simplified steps in setting up a call

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PSTN GMSC HLR MSC/VLRA-Subscriber

CALL SETUP (MSISDN)

ANALYSE NUMBERCALL SETUP (MSISDN)

MSISDN

IMSI

MSRNMSRN

CALL SETUP (MSRN)

PAGING

Figure 3.2. The Paging Process

1. A subscriber in a fixed network dials a number of a mobile phone. The dialled number is the MSISDN.

2. The Public Switched Telephone Network (PSTN) exchange analyses the number and contacts the Gateway Mobile Services

Switching Centre (GMSC).

3. The Gateway MSC analyses the MSISDN and sends a message to the Home Location Register (HLR).

4. The HLR checks its database to determine the current location of the called subscriber.

5. The HLR interrogates the MSC/VLR (Visitor Location Register) that is currently serving the called subscriber.

6. The serving MSC/VLR generates a temporary MSRN (Mobile Subscriber Roaming Number).

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BTS BTS

Paging

BTS

Mobile responds to paging

Location Area

Paging

Paging

7. MSC/VLR sends MSRN to HLR and the HLR forwards the MSRN to the GMSC.

8. The GMSC identifies the serving MSC/VLR as the destination for routing the call.

9. Destination MSC/VLR receives MSRN. It identifies the number that is called and traces the called subscriber.

The destination MSC/VLR initiates a paging process in the Location Area to locate the called subscriber. The mobile phone of the

called subscriber recognises the paging signal and answers it

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EXC GMSC HLR MSC VLR BSS MS

1. channel assignment

2. security procedures

3. call setup

4. check services etc.

5. all ok

6. call is proceeding

7. traffic channel allocated

8. set up the call

9. call set up complete

10. alert

11. B answers

Figure 3.3 : Mobile Originated Call Procedure

3.2 Location Update

Types of Location Update

In practice, there are three types of location updates:

1. Location Registration (power on)

2. Generic

3. Periodic

Location registration takes place when a mobile station is turned on. This is also known as IMSI Attach because as soon as the

mobile station is switched on it informs the Visitor Location Register (VLR) that it is now back in service and is able to receive calls.

As a result of a successful registration, the network sends the mobile station two numbers that are stored in the SIM (Subscriber

Identity Module) card of the mobile station.

These two numbers are the Location Area Identity (LAI) and the Temporary Mobile Subscriber Identity (TMSI). The network, via

the control channels of the air interface, sends the LAI. The TMSI is used for security purposes, so that the IMSI of a subscriber does

not have to be transmitted over the air interface. The TMSI is a temporary identity, which regularly gets changed.

A Location Area Identity (LAI) is a globally unique number.

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LA 2LA 1

VLR

MSC

A Location Area Code (LAC) is only unique in a particular network.

Figure 3.4 : Location Update

Every time the mobile receives data through the control channels, it reads the LAI and compares it with the LAI stored in its SIM card.

A generic location update is performed if they are different. The mobile starts a Location Update process by accessing the

MSC/VLR that sent the location data .A channel request message is sent that contains the subscriber identity (i.e. IMSI/TMSI) and

the LAI stored in the SIM card. When the target MSC/VLR receives the request, it reads the old LAI which identifies the MSC/VLR

that has served the mobile phone up to this point. A signalling connection is established between the two MSC/VLRs and the

subscriber’s IMSI is transferred from the old MSC to the new MSC. Using this IMSI, the new MSC requests the subscriber data from

the HLR and then updates the VLR and HLR after successful authentication.

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Figure 3.5: location update procedure

3.3 Handover

In a mobile communications network, the subscriber can move around. How can we maintain the connection in such cases? To

understand this, we must study the process of handing over the calls.Maintaining the traffic connection with a moving subscriber is

made possible with the help of the handover function. The basic concept is simple: when the subscriber moves from the coverage area

of one cell to another, a new connection with the target cell has to be set up and the connection with the old cell has to be released.

There are two reasons for performing a handover:

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MS BSS MSC VLRnew VLRold HLR

1. channel assignment

3. request subscriber identity

4. request subscriber identity

5. request subscriber data

6. request subscriber data7. security procedures

2. location update request

8. update location

9. update HLR

10. update acknowledgement

11. cancel old location

12. location cancelling accepted

1. Handover due to measurements occurs when the quality or the strength of the radio signal falls below certain parameters

specified in the BSC. The deterioration of the signal is detected by the constant signal measurements carried out by both the

mobile station and the BTS. As a consequence, the connection is handed over to a cell with a stronger signal.

2. Handover due to traffic reasons occurs when the traffic capacity of a cell has reached its maximum or is approaching it. In

such a case, the mobile stations near the edges of the cell may be handed over to neighbouring cells with less traffic load.

The decision to perform a handover is always made by the BSC that is currently serving the subscriber, except for the handover for

traffic reasons. In the latter case the MSC makes the decision. There are four different types of handover and the best way to analyze

them is to follow the subscriber as he moves:

Intra cell - Intra BSC handoverThe smallest of the handovers is the intra cell handover where the subscriber is handed over to

another traffic channel (generally in another frequency) within the same cell. In this case the BSC controlling the cell makes the

decision to perform hanover.

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Air A

TCBTS BSC

Figure: 3.6 Intra Cell - Intra BSC Handover

Inter cell - Intra BSC handover

The subscriber moves from cell 1 to cell 2. In this case the handover process is controlled by BSC. The traffic connection with cell 1 is

released when the connection with cell 2 is set up successfully.

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Figure 3.7: Inter Cell - Intra BSC handover

Inter cell - Inter BSC handover

The subscriber moves from cell 2 to cell 3, which is served by another BSC. In this case the handover process is carried out by the

MSC, but, the decision to make the handover is still done by the first BSC. The connection with the first BSC (and BTS) is released

when the connection with the new BSC (and BTS) is set up successfully.

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Figure3.8: InterCell-InterBSCHandover

Inter MSC handover

The subscriber moves from a cell controlled by one MSC/VLR to a cell in the domain of another MSC/VLR. This case is a bit more

complicated. Considering that the first MSC/VLR is connected to the GMSC via a link that passes through PSTN lines, it is evident

that the second MSC/VLR can not take over the first one just like that.

The MSC/VLR currently serving the subscriber (also known as the anchor MSC), contacts the target MSC/VLR and the traffic

connection is transferred to the target MSC/VLR. As both MSCs are part of the same network, the connection is established smoothly.

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It is important to notice, however, that the target MSC and the source MSC are two telephone exchanges. The call can be transferred

between two exchanges only if there is a telephone number identifying the target MSC.

Fig 3.9: Inter Cell - Inter MSC Handover

Such a situation makes it necessary to generate a new number, the Handover Number (HON). The generation and function of the

HON are explained in the following text.

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The anchor MSC/VLR receives the handover information from the BSS. It recognises that the destination is within the domain of

another MSC and sends a Handover Request to the target MSC via the signaling network. The target MSC answers by generating a

HON and sends it to the anchor MSC/VLR, which performs a digit analysis in order to obtain the necessary routing information.

This information allows the serving MSC/VLR to connect the target MSC/VLR. When the two MSCs are connected, the call is

transferred to a new route.

In practice, the handover number is similar to the roaming number. Moreover, the roaming number and the handover number have a

similar purpose, that is connecting two MSCs. The structure of the handover number is shown below:

HON = CC + NDC + SN

CC= Country Code

NDC= National Destination Code (of the serving network)

SN= Subscriber Number

The call will not last forever and the connection has to be released sooner or later. To understand the process of releasing the

connection, we must consider a few things such as: Who pays for the call, which exchange takes care of the charging operation and

where is the subscriber data stored.

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Chapter 4

RF PLANNING

4.1 Objective

The overall objectives of any RF Design depend on a number of factors that are determined by the needs and expectations of the

operator, the resources made available by the operator, any service levels determined by the contract between operator and Vendor but

only as they affect the RF Design, and the resources that are available at the Technical Centre or Business Unit that is responsible for

the RF Design.

Generally speaking the RF Design should satisfy the following criteria:-

Maximizing coverage

Providing sufficient capacity

Providing an acceptable quality of service

Minimizing cost

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4.2 RF Design

The RF design engineer for that particular region would then decide the type of antenna to be used, the antenna height above ground

level, Frequency Re Use pattern; the antenna orientation, the antenna mechanical or electrical down tilt if required and the base station

maximum transmit power. RF Design includes the following:

Antenna Selection

LAC Design

Grid Design

Morphology Definition

Link Budget

Frequency Re Use Technique

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Traffic Analysis

Nominal Cell Plan

System Growth

System Tuning

System Installation Coverage & InterferencePrediction

The Cell Planning Process

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Cell planning begins with traffic and coverage analysis. The analysis should produce information about the geographical area and the

expected capacity (traffic load). The types of data collected are:

Cost

Capacity

Coverage

Grade Of Service (GOS)

Available frequencies

Speech quality

System growth capability

The basis for all cell planning is the traffic demand, i.e. how many subscribers use the network and how much traffic they generate.

The Erlang (E) is a unit of measurement of traffic intensity.

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It can be calculated with the following formula:

A = n x T / 3600 Erlang

Where,

A = offered traffic from one or more users in the system

n = number of calls per hour

T = average call time in seconds

The geographical distribution of traffic demand can be calculated by the use of demographic data such as:

Population distribution

Car usage distribution

Income level distribution

Land usage data

Telephone usage statistics

Other factors, like subscription/call charge and price of MSs

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4.3 RF Drive Test

Every good RF design, after its implantation should be evaluated. There are few ways to do this, for example through analysis of KPI

(Key Performance Indicator) or through prediction tools and signal interference. Other very common and efficient way to evaluate the

network is conducting a Drive Test. But what is it?

The name is intuitive: take a drive test. The Drive Test is a test performed in cellular networks regardless of technology (GSM,

CDMA, UMTS, LTE, etc. ...). Means collecting data on vehicle movement. Its variation has also intuitive: Walk Test, ie, collect data

by walking areas of interest.

The analysis of drive test is fundamental for the work of any professional in the field of IT and Telecom comprising two phases: data

collection and data analysis.

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Figure 4.1 : Drive Test Setup

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Types of Drive Test

The main types of Drive Test are :

Performance Analysis

Integration of New Sites and change parameters of Existing Sites

Marketing

Benchmarking

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Figure 4.2 : Drive Test Result

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Chapter 5

TRANSMISSION AND PLANNING

5.1 Introduction

The propagation of radio waves is generally affected by several factors, irrespective of the radio communication service or the

specified purpose of telecommunication. These factors are described below.

5.2 Propagation Mechanisms

Depending on topography and meteorological conditions,radio wave can be propagated in different ways,normally,but not

always,causing attenuation.One of the main tasks of radio engineering is to evaluate the attenuation of radio signals between

transmitters and receivers.

In order to do this,it is helpful to categorize propagation mechanisms:

Free Space Propagation

Refraction

Diffraction

Reflection and Scattering

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Absorption

Line Of Sight

The earth atmosphere influences the propagation of radion waves in different ways.The radio waves travel with different

velocities in different parts of the atmosphere,due to the variations in the electrical characteristics,which cause refaction.

Due to the atmospheric refraction the radio waves are usually bent slightly downwards,which allows a somewhat longer path

length than the straight line With the bending effect in mind it is customary to speak about a radio optic line of sight,rather than a

geometricalline of sight.Under normal conditions the radio optic line of sight reaches further than a geometrical line of sight.

The standard atmosphere and the other atmospheric conditions affecting the refraction factor and which occurs at a given site is

described by the earth radius factor k.The k value depending on the climatic conditions is 4/3 when applied to a standard

atmosphere.

Figure:5.1 : Line of Sight

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The First Fresnel Zone

The radio optical Earth radius can be described using the effective Earth radius factor.

Clearance

Even if free line of sight is available on the entire path,close-by obstacles might have an attenuating effect if they ae loacated close

enough to the path .It is customary to define a fresnel zone around the centerline of the path.the first Fresnel zone is defined as azone

sshaped as an eellipsoid with its focal points at the antennas on both ends of the path.The fresnel zone decreases with increasing

frequency.

Provided that there is no obstacle within the first Fresnel zone the obstacle attenuation can be ignored,the clearance requirement is

satisfied .

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Figure:5.2:The first Fresnel zone

5.3 Path Profiles

The purpose of the path profile is to provide information concerning free line of sight between the selected station sites, and to decide

whether there is sufficient clearance to avoid obstacle attenuation.The path profile will also be used when determining the fading of

the received signal.

The path profile is essentially a plot of the elevation of the arth as a function of the distance along the path between the transmitting

and receiving sites.The data is derived by locating the two terminals on an elevation contour map,drawing a straight linebetween the

two points,and reading the elevation contours at suitable distance intervals.

The topographical information used to design a path profile can also be derived from topographical map databases,which include an

altitude databse and a land use database.

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5.4 Path and Site Survey

During the planning microwave radio link paths it is often necessary to closely survey the intended Hop on the location in order to

evaluate the Obstacles by sight.Also the intended site and antenna carrier site should bechecked concerning space,power availability

and strength.The following checked list covers the important items to be investigated.

The geometrical position of the intended site.

The antenna carrier height above groun level.

The antenna carrier type,strength and torsion strength.

The site altitude above mean sea level.

The possibility of installing antennas required height.

All obstacles in path directions,including their heights and widths.

Potential reflecting surfaces.

The radio environment.other radio installations or interfering signals.

The distance between indoor and outdoor equipment.

The main power availability.

The battery backup possibilities.

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The possibilities to install antenna feeders or multi-conductors cables between indoor and outdoor equipment regarding

available space,grounding,wall entrance,bending radii etc.

For new sites,access to roads and to power transformer stations must be considered.

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REFERENCE

Study training material at Vodafone,Ranchi

www.google.com

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