Alcatel-Lucent Drive Test-1 Part-1.pdf

8/14/2019 Alcatel-Lucent Drive Test-1 Part-1.pdf

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Drive Test OverviewDrive Test Overview

Created by

Pulok Sinha Trainer ALUMS

All Rights Reserved Alcatel-Lucent 2009

09320096525


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ObjectivesObjectives

In this session following aspects will be covered:

Drive Test and its significance.

Drive Test kit and its accessories.

Basic definition

Process involved in Drive Test

Basic Rules of Drive Test

General DT Kit Issue



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Drive Test and Its SignificanceDrive Test and Its Significance



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Definition:Definition:

Drive test is real time process by which various networkparameters of an operational network are gathered and are

Analysis of Downlink Network performance

Network optimization.



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Significance of Drive Test is to:Significance of Drive Test is to:

Verify performance of new sites

Verify Frequency Plan

Verify handovers



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Significance of Drive Test is to:Significance of Drive Test is to:

Verify Interference

Verify data after ReHomes

Benchmarking



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Modes of Drive Test:Modes of Drive Test:

Idle mode Drive test:

Dedicated Mode Drive Test

To check the voice or data performance



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Drive Test Kit and its AccessoriesDrive Test Kit and its Accessories



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DriveDrive TestTest KitKit::

La to

Drive Test SoftwareTest Mobile

Global Positioning System (GPS)

Cables and Connectors

Drivers Software



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Laptop:

It basically is the user interface in which the Drive Test Software

is installed and is used to collect and store the log files.

The drive Test software controls the whole process and integrates

the information received by the test mobile with that provided bye rece ver.

est Mobile:

The test mobile monitors the GSM channels for the appropriate

messages and can simulate subscriber actions.



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Global Positioning System (GPS):

The GPS provides positioning information to be used in conjunction

with the collated network data.

Cables and Connectors:

Cables and connectors are needed for Connection of external

accessories. For Example - like Data Cable for Mobile, GPS Cable,PCMCIA Card, etc

Drivers Software:

The external accessories may not be compatible to the Laptop so

specific drivers of those are needed to be installed.



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Available Drive Test Tools:Available Drive Test Tools:

NEMO (Anite)

AGILENT A ilent Technolo ies

NTAS (Beijing Rising Technology Co. Ltd.)



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Basic DefinitionBasic Definition



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DecibelDecibel (dB)(dB)

or loss.Decibel is logarithmic value that represent ratio of two given

.

dB can be expressed as follows:

= og o in

The powers Poad Pinmust be in the same units. If the units are

, .Equal power corresponds to 0dB.



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Decibel with respect to milliDecibel with respect to milli--watt (watt (dBm)dBm)

to a 1 milli-watt reference signal.

It is different from the dB because A dB has no particular

defined reference while a dBm is referenced to a specific

quantity: the milli-watt (1/1000 of a watt).

dBm =10 log10 (Signal Power / .001 watt )



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Pr opagat i on MechanismsPr opagat i on Mechanisms

Re lectionRe lection

Occurs when a wave impinges upon a smooth surface.Dimensions of the surface are large relative to .

e ec ons occur rom e sur ace o e ear , rom u ngs,

walls, mountains, etc.

DiffractionDiffraction (Shadowing)(Shadowing)

Occurs when the path is blocked by an object with large

.

Diffraction gives rise to bending of waves around the obstacle.



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ScatteringScattering

on the order of or less, causing the reflected energy to spreadout or scatter in many directions.

Small objects such as street lights, signs, & leaves cause

scattering



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AntennasAntennas

Antenna is an essential art of a transmittin or receivin

system which is designed to radiate or to receive

electromagnetic waves.

n an enna can a so e v ewe as a rans ona s ruc ure

between free-space and a transmission line (such as a coaxial

line).

An important property of an antenna is the ability to focus and

shape the radiated power in space e.g.: it enhances the power

in some wanted directions and suppresses the power in other

directions.

Many different types and mechanical forms of antennas exist


.


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AntennaAntenna TypesTypes

In mobile communications two main categories of antennas used

are:

OmniOmni directionaldirectional antennaantenna

These antennas radiates equally in all horizontal direction.



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DirectionalDirectional antennaantenna

These antennas are mostly used to get higher gain compared

to Omni-directional antenna and to minimise interference

effects in the network.

In these t e of antennas the radiation is directed at a

specific angle instead of uniformly across all azimuth angles

in case of Omni antennas.



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RadiationRadiation PatternPattern

The main characteristics of antenna is the radiation pattern.

The antenna pattern is a graphical representation in threedimensions of the radiation of the antenna as a function of

an ular direction.

Antenna radiation performance is usually measured and

recorded in two orthogonal principal planes (E-Plane and H-.

The pattern of most base station antennas contains a main

lobe and several minor lobes, termed side lobes.

A side lobe occurring in space in the direction opposite to themain lobe is called back lobe.



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RadiationRadiation PatternPattern



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Directivity of Antenna:Directivity of Antenna:

Directivity is the ability of an antenna to focus energy in a

particular direction when transmitting or to receive energy

better from a particular direction when receiving.

a n o n enna:a n o n enna:

The gain is a measure of how much of the input power is

concentrated in a particular direction.

It is expressed with respect to a hypothetical isotropic

antenna, which radiates equally in all directions.

parameter which describes the efficiency of the antenna.

G= .D



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Beamwidth of an Antenna:Beamwidth of an Antenna:

Beamwidth is usually understood to mean the half-power

beamwidth.

Half power Beamwidth (HPBW) is the angle between the half-

power points of the main lobe, referenced to the peak power of

main lobe.

Beam width is categorized as:

Vertical Beamwidth

Beamwidth is measured in degrees.



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Horizontal Beamwidth:Horizontal Beamwidth:

Horizontal beamwidth is the beamwidth of the radiation pattern

in Horizontal Plane .

Generally, in City, antenna with 65Horizontal Beamwidth isused and in highway antenna with 33Horizontal Beam widthis used.

Vertical Beamwidth of an antenna is the beamwidth of the

radiation pattern in vertical plane.

Vertical beamwidth Varies from 4 - 8 depending upon themodel of the antenna



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Relation between Beam width, Gain and DirectivityRelation between Beam width, Gain and Directivity

Beamwidth Ga n D rect v ty



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Azimuth:Azimuth:

An azimuth is an angular measurement in a spherical

coordinate system. It gives apparent direction of an object

It is measured in degrees.



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Obstacle requirementObstacle requirement



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Antenna Tilt:Antenna Tilt:

The tilting of the vertical main lobe towards the ground by

specific angle with respect to horizon is known Antenna tilting.

The Maximum power of the lobe is at zero and can be place

within the cell by down tilting the antenna.

Down tilt can be use to:

Improve the coverage

Adjust the cell radius

Basically there are two types of Down tilting

Mechanical TiltElectrical Tilt



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Mechanical Down tiltMechanical Down tilt

In Mechanical down tilting,

Electrical Down TiltElectrical Down Tilt

In Electrical down tilt, the

antenna is physically down

tilted towards the ground.

In a mechanical down tilt as

beam is tilted by altering the

signal phasing.

Electrical tilting is done by

the front lobe moves downward

the back lobe moves upwards.

Side lobe increase with

using the tilt knob integrated in

the antenna

In Electrical down tiltin allmechanical down tilting

Mechanical tilt have no impact

on the ain.

the lobes (main, back as well as

side) has distinct advantage of

tilting

In electrical down tilting, gainalso reduces in all direction



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Mechanically tilted Antenna Electrically tilted Antenna

33


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Multipath Propagation:Multipath Propagation:

Multi ath is the result of reflections and scatterin of radiowaves due to buildings, mountains and other objects, etc.

Multipath, in effect, creates multiple transmission path of thesignal which arrive at the receiver at different times

When the components are in phase, the signal gets added.

When they arrive out of phase, they cancel each other.

Rayleigh Fading

Ricean fading



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Rayleigh FadingRayleigh Fading

The Rayleigh fading is applicable to obstructed propagationpaths.

All the signals are NLOS signals and there is no dominant directpath.

Signals from all paths have comparable signal strengths.

The instantaneous received power seen by a moving antenna

becomes a random variable depending on the location of theantenna.



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Ricean FadingRicean Fading

This phenomenon is due to multipath propagation of thesignal.

In this case there is a partially scattered field.

One dominant si nal.

Others are weaker.



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Diversity:Diversity:

vers y ec n ques s an e ec ve means w c en ances e

immunity of the communication system to the multipath fading.

Diversity reception is a way to improve the quality and strength

of the signal arriving at the base station, by receiving it in several

independent ways

Two forms of diversity reception often employed are:

Polarization diversity



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Spatial (Space) DiversitySpatial (Space) Diversity

The spatial diversity antenna system is constructed by physically

separating two receiving base station antennas.

If they are far apart, the received signals will be independent of

each other.

If one has suffered fading, the other may not.

A suitable distance is generally about 10 wavelengths (10)

an v ews o wo poss e r -sec ore s e an enna sys ems



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Vertical Polarized antenna:Vertical Polarized antenna:

Good diversity performance only in cities

Horizontal termination cannot be used for Tx

Cross Polarized antennaCross Polarized antenna

cities or in rural areas

Both terminations are suitable for Rx and Tx


P I l d i D i T tP I l d i D i T t


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Process Involved in Drive TestProcess Involved in Drive Test




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TestTest::

Collection of Data

Post Processing

Analysis of the extracted data.

Suggesting changes based on

the anal sis.




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Drive test involves collection of various radio parameters and airinterference signal data as Log File. These Log Files are further

.

PostPost ProcessinProcessin ::From the data collected, various information can be extracted

which depict the performance of BTS sites and the network as a

whole.




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The information extracted from the collected data is thenanalysed. It is used to infer cause of detected problem in the

.

Su estinSu estin chan eschan es basedbased onon thethe anal sisanal sis::After detection of the causes of the deviation from the

requirement or network related problems, measures are taken to

im rove the erformance of the network and to match

customers requirement.




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Example of RxLev Plot:Example of RxLev Plot:




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Example of RxQual Plot:Example of RxQual Plot:




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Example of C/I Plot:Example of C/I Plot:


Basic Rules for Drive TestBasic Rules for Drive Test


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Basic Points for drive test:Basic Points for drive test:

As soon as sites are allocated, verify the data in database and

plan your work accordingly.

p a e e ce e rom a es a a ase.

Before moving for the site, make sure that all the equipments

.

Performance Effecting Alarm Should be checked.

While going to the site one must keep the Drive Test kit on andcontinuously track the Cell ID, BCCH ARFCN and BSIC to

search the site.




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After reaching to the site one must verify the corresponding Cell

ID BCCH ARFCN and BSIC for the each sector.

Pre-drive of the site need to be done.

ys ca ver ca on v z. ower e g , u ng e g , o a

tower height, GSM antenna height, Orientation, Tilt, Antenna

Model etc. to be noted.

Orientation of antenna should be taken properly and compass

should be kept away from mobile, watch, any magnetic metal

Before using compass, its magnetic needle should be check

ro erl for an shift.




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The tracker for physical data should me maintained regularly

and should be send on re ular basis.

Feeder Cables are to be traced and the connectors need to bechecked accordingly. If any anomalies are found, has to be

reported and rectified accordingly.

No obstacle should be there in main lobe of antenna.

Proper route should be covered while drive, if routes not given

all the roads in each sector should be covered.

Driving the same road twice should be avoided or else record aseparate log file.




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While driving over a bridge or in to a tunnel, always make a

separate log file.

While drive Short calls as well as Long calls are to be made.

the termination successfully, it also determines the setup time.

Long calls are to test the hand over capabilities as well as RXLevel and RX Qual.

Intra and inter handovers with each neighbours should be

verified properly and should be reported if any anomalies found.

The vehicle speed should be maintained between 20-40 km per


our, o no per orm r ve es a g spee .



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Log files should not be too heavy nor should it be too small.

Generally, Log file of 5-15 MB is recorded.

Each and every log file should be named such that it gives aclear picture for what the log file is. For example,

TypeOfDrive _ SiteClutterRouteName _ DateShortCall_Bandra_18072010 / LongCall_BSC10_18072010

, ,

leaving the site.

Distance and direction of any obstacles blocking in the way

should be noted. Finally, report all sorts of problems.


General DT Kit IssueGeneral DT Kit Issue


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Check if dongle is properly connected. Dongle has to be

connected first.

Check if there is any loose connection, if it is there the

tightened it.

port

Check if the respective drivers have been installed properly for

- -, ,RS232 driver, etc

If there is more than two handset check the level of each

first swapping the data cable and then swapping the ports.By this, one can find if the problem is with the Handset, Data

Cable or Port.




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If problem is with the hand set then change the soft port of the

handset and then verify it.

If the kits gets hang close all application one by one then, turn

off the KIT and Disconnect all the external peripherals, wait forsome time and again start it, connect the dongle and then

connect each of the peripherals one by one.

Eye should be kept on MS connection as well as GPS

connection as they should not get disconnected. Moreover, kit should be as per configuration to support

required no of Handsets, else may face problem of kit hanging.

should be there, else accessories may get damage decreasingthe engineer o/p.


QuestionsQuestions


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QuestionsQuestions


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