Analysis And Measurement Fiber Optic Fault By Using Optical Time Domain Reflectrometer (OTDR).
ANALYSIS AND MEASUREMENT FIBER OPTIC FAULT BY USING
OPTICAL TIME DOMAIN REFLECTROMETER (OTDR)
AKWANIZAM BIN AZMI
This Report Is Submitted in Partial Fulfillment of the Requirements for the
award of Bachelor of Electronic Engineering (Telecommunication Electronics)
With Honours
Faculty of Electronic Engineering and Computer Engineering
Universiti Teknikal Malaysia Melaka
30 April 2009
ii
UNIVERSTI TEKNIKAL MALAYSIA MELAKA
FAKULTI KEJURUTERAAN ELEKTRONIK DAN KEJURUTERAAN KOMPUTER
BORANG PENGESAHAN STATUS LAPORAN
PROJEK SARJANA MUDA II
Tajuk Projek
ANALYSIS AND MEASUREMENT FIBER OPTIC FAULT
:
BY USING OPTICAL TIME DOMAIN REFLECTROMETER
(OTDR)
Sesi
Pengajian
2005/09
:
Saya ………………………....AKWANIZAM BIN AZMI…………………………..……..
(HURUF BESAR)
mengaku membenarkan Laporan Projek Sarjana Muda ini disimpan di Perpustakaan dengan syaratsyarat kegunaan seperti berikut:
1.
Laporan adalah hakmilik Universiti Teknikal Malaysia Melaka.
2.
Perpustakaan dibenarkan membuat salinan untuk tujuan pengajian sahaja.
3.
Perpustakaan dibenarkan membuat salinan laporan ini sebagai bahan pertukaran antara institusi
pengajian tinggi.
4.
Sila tandakan (
):
SULIT*
(Mengandungi maklumat yang berdarjah keselamatan atau
kepentingan Malaysia seperti yang termaktub di dalam AKTA
RAHSIA RASMI 1972)
TERHAD*
(Mengandungi maklumat terhad yang telah ditentukan oleh
organisasi/badan di mana penyelidikan dijalankan)
TIDAK TERHAD
Disahkan oleh:
__________________________
(TANDATANGAN PENULIS)
Alamat : Lot 572 Kg. Air Merah,
86800, Mersing Johor
___________________________________
(COP DAN TANDATANGAN PENYELIA)
iii
“I declared that this thesis is the result of my own work except the ideas and
summaries which I have clarified their sources.”
Signature
: ………………………………………
Writer
: AKWANIZAM BIN AZMI
Date
: 30 April 2009
iv
“I hereby declare that I have read this report and in my opinion this report is
sufficient in terms of the scope and quality for the award of Bachelor of Electronic
Engineering (Telecommunication Electronic) With Honours”
Signature
: ………………………………………
Supervisor’s Name
: IR. CHAIRULSYAH WASLI
Date
:
v
DEDICATION
Special dedication to my beloved father and mother, my entire sibling and my kind
hearted supervisor Ir. Chairulsyah Wasli and my dearest friends.
vi
ACKNOWLEDGEMENT
Firstly, I would like to thank Allah because with His blessing I am able to
prepare this report and final project for Universiti Teknikal Malaysia Melaka. I wish
to thank all those who helped and encouraged me to complete my Bachelor of
Electronic Engineering (Telecommunication Electronics).
I would like to extend my sincere gratitude to my supervisor, Ir. Chairulsyah
Wasli, for his assistance and guidance toward the progress of this thesis project.
Through the year, Ir. Chairulsyah Wasli has been patiently monitoring my progress
and guided me in the right direction and offering encouragement. Obviously the
progress I had now will be uncertain without his assistance.
Likewise, I would like to thank my second supervisor, Dr Abdul Samad Bin
Shibghatullah for his assistance in creating animation by using the suitable software
and make this project possible. I would like to thank Hafizul for his encouragement
and help. Special thank to my friends Hafiz Nazar, Al-Amin and all my housemate
for giving me support and encourage me to finish this report.
This project would not have been like this if they not given great support and
encouragement on me when other academic assignments and test has pressured me.
The golden glory for me was during accomplishing this project is when my project
successfully completed in the right path.
Most of all, I would like to thank my parents for their unending support, and
my brother, whose mere existence keeps me motivated.
vii
ABSTRACT
The purpose of this project was to measure the fiber optic faults by using
Optical Time Domain Reflectrometer (OTDR) and at the same time to analyze fiber
optic faults. The software which will be used is based on the existing OTDR
simulation. The cases of fiber optic faults were learned before upgrade the OTDR
simulation. Each case is represented in form of graph for normal condition and
abnormal condition. Flash CS3 software was used to create each graph in animation
form. Then, the OTDR instrument was learned in detail by applying the instrument in
field study. The true result of fiber optic faults was investigated by using the
instrument. The result from theoretical and experimental OTDR will be compared to
ensure the valid results are obtained. The experimental OTDR is set for students in
Opto electronic laboratory. From this experiment, students can easy to understand the
operation of OTDR and they can investigate a few of events in fiber optic cable
efficiently.
viii
ABSTRAK
Tujuan projek ini ialah untuk mengukur tingkat kerosakan fiber optik dengan
menggunakan Optical Time Domain Reflectrometer (OTDR) dan pada masa yang
sama untuk menganalisa kerosakannya. Software yang akan digunakan adalah
berdasar pada simulasi OTDR yang sedia ada. Kes-kes kerosakan fiber optik
dipelajari sebelum menambah baik simulasi OTDR. Setiap kes diwakili dalam
bentuk graf untuk keadaan normal dan sebaliknya. Software Flash CS3 digunakan
untuk membuat graf dalam bentuk animasi. Kemudian, alat OTDR dipelajari dengan
mendalam, dengan menggunakan alat tersebut pada kajian lapangan. Keputusan
sebenar kerosakan fiber optik dikaji dengan menggunakan alat tersebut. Keputusan
daripada teori dan eksperimen akan dibandingkan untuk memastikan keputusan yang
betul diperolehi. Eksperimen OTDR dibuat untuk memudahkan pelajar menjalani
eksperimen ini pada masa akan datang. Para pelajar akan dapat memahami
bagaimana OTDR ini berfungsi daripada awal hingga akhir selepas mereka
melakukan eksperimen ini.
ix
TABLE OF CONTENTS
CHAPTER
I
TITLE
PAGE
THESIS TITLE
i
DECLARATION
iii
DEDICATION
v
ACKNOWLEDGEMENT
vi
ABSTRACT
vii
ABSTRAK
viii
TABLE OF CONTENTS
ix
LIST OF TABLES
xii
LIST OF FIGURES
xiii
LIST OF SYMBOLS
xv
INTRODUCTION
1
1.1
PROJECT BACKGROUND
1
1.2
SCOPE OF WORKS
2
1.3
PROBLEMS STATEMENT
2
1.4
PROJECT OBJECTIVES
3
1.5
PROJECT’S METHODOLOGY
3
1.6
REPORT STRUCTURE
5
x
II
LITERATURE REVIEW
6
2.1
INTRODUCTION
6
2.2
FIBER OPTIC LINK
7
2.3
OPTICAL FIBER CABLE
8
2.4
FIBER CLASSIFICATIONS
10
2.4.1 Single-Mode Step-Index
10
2.4.2 Multimode Step-Index
11
2.4.3 Multimode Graded-Index
12
2.5
PRINCIPLE OF OPERATION
12
2.6
ATTENUATION IN FIBER OPTIC
13
2.6.1 Dispersion
14
2.7
III
2.6.1.1 Modal Dispersion
15
2.6.1.2 Chromatic Dispersion
15
2.6.1.3 Polarization Dispersion
16
2.6.2 Absorption
17
2.6.3 Scattering
18
2.6.3.1 Stimulated Raman Scattering
19
2.6.3.2 Stimulated Brillouin Scattering
19
2.6.4 Optical Return Loss
19
APPLICATION OF OTDR
20
METHODOLOGY
21
3.1
INTRODUCTION
21
3.2
COLLECTION DATA
21
3.3
PROJECT PLANNING
22
3.4
ANIMATION TROUBLESHOOTING
23
3.5
INTRODUCTION OF OTDR
23
3.6
THE WORK OF OTDR
25
3.7
INFORMATION IN THE OTDR TRACE
28
3.7.1 Overload Recovery
29
3.7.2 Ghosts
30
xi
3.8
IV
OVERCOMING BACKSCATTER ERRORS
33
3.8.1 Resolution Limitations
33
3.8.2 Consideration For Multimode Fiber
34
RESULT AND DISCUSSION
36
4.1
RESULT FROM ANIMATION OF OTDR
36
4.2
CALCULATION RESULT AND ANALYSIS
42
4.2.1 Creating Formula
42
4.2.2 Backscattering
45
4.2.3 Reflectance
47
4.2.4 Reflection Amplitude-ORL
Specification
V
49
CONCLUSIONS
55
5.1
CONCLUSION
55
5.2
RECOMMENDATION
56
REFERENCES
APPENDIXS
57
xii
LIST OF TABLE
TABLE
TITLE
3.1
The function of each block OTDR
25
4.2
Output Power Values
44
4.3
Backscattering value
46
4.4
Typical values of backscatter coefficient for
48
Multimode fibers
PAGE
xiii
LIST OF FIGURE
FIGURE
TITLE
PAGE
1.1
Project Flowchart
2.1
Model of simple fiber optic data link
7
2.2
Fiber optic cable structure
8
2.3
Process of transmission light
9
2.4
Single-mode step index fiber
10
2.5
Multimode step-index optical fiber
11
2.6
Multimode Grade-index optical fiber
11
2.7
Snell’s law
12
2.8
Typical Dispersion vs. Wavelength Curves
14
2.9
Lingering materials
16
3.1
Gantt chart
19
3.3
The block diagram of the conventional OTDR
21
3.4
Scattering in an optical fiber
23
3.5
OTDR Display
24
3.6
Increasing the pulse width increases the backscatter level
24
3.7
OTDR trace information
26
3.8
OTDR launch pulse and launch cable
28
3.9
OTDR ghosts
29
3.10
Loss errors in OTDR measurements
30
.
4
xiv
LIST OF FIGURE
FIGURE
TITLE
PAGE
3.11
The OTDR pulse length limits its resolution .
34
3.12
OTDR see middle of multimode fiber core
35
4.1
Build of OTDR buttons
36
4.2
Display of graph case 1
37
4.3
Display of graph case 2
37
4.4
Display of graph case 3
38
4.5
Comparing of each graph in a figure
39
4.6
Display of graph from oscilloscope
40
4.7
Display of graph case 4
41
4.8
The fiber optic block diagram
42
4.9
The loss of fiber optic
43
4.10
Graph of output power versus length
45
4.11
Graph of backscattering versus distance
47
4.12
ORL value of a reflection feature
49
4.13
OTDR pulse generator software
52
4.14
Building of an experimental OTDR
52
4.15
Measurement of power
53
4.16
Result of Experimental OTDR
53
xv
LIST OF SYMBOL / ACRONYM
ADC
Analog Digital Converter
APD
Avalance Photodiode
DC
Direct Current
GI
Graded Index
LED
Light Emitting Diode
OTDR
Optical time domain reflectrometer
PD
Photo diode
SI
Step Index
I/O
Input and Output
Pi
Input power
Pin
Incident power
PT
Transferring power
Pref
Reflected power
Po
Output power
a
Attenuation
R
Reflectance
l
Length
L
Loss
d
distance
K @ B (s-1)
Backscattering coefficient
A
Reflection amplitude (in dB), as measured by the OTDR
T
V
OTDR measurement pulse width (in nanoseconds)
Voltage
xvi
APPENDIX LIST
APPENDIX TITLE
PAGES
A
YOKOGAWA OTDR
58
B
Fiber optic patch cord
68
C
Characteristics of fiber
70
D
Experimental OTDR Laboratory
72-84
CHAPTER I
INTRODUCTION
1.1
PROJECT BACKGROUND
In telecommunication field, fiber optic cable is the main part of transmission
of data. So, one of the main maintenance instruments fiber optic cable is optical
time-domain reflectrometer (OTDR). This instrument is used to test fiber links by
detecting losses and to know what types of faults have occurred on these links, as
well as where they are located. Generally, there are a few types of fiber faults likes
overload recovery, ghosts and backscatter variability errors.
Before this instrument is used in fiber optic cable plant, we should understand
how it works, the function of its buttons and what the types of types of faults. If not,
we will face problems of using it. We should have sufficient knowledge of OTDR
operation to ensure that the good data can be obtained and it will be used optimally.
This project is targeted to accomplish finish in six months timeline. The
ultimate goal is to examine the OTDR in detail and show the examples of good and
bad data by using flash CS3 software. Beside this, experimental OTDR is set for
optoelectronic laboratory which will be used by students.
2
1.2
SCOPES OF WORK
The scopes of work for the project include the following areas:
i.
The study and understanding of OTDR the cases of fiber optic faults.
ii.
Build the animation for fiber faults cases by using Flash CS3.
iii.
Find the a few types of OTDR simulation and investigate them.
iv.
Find the true result of OTDR cases and compare with theoretical animation.
v.
The analysis of the fiber optic faults from the OTDR instrument.
Other scopes of work include:
1.3
1.
Maintain good log book record
2.
Prepare the necessary documents
3.
Publishing final report
4.
Project Presentation
PROBLEM STATEMENTS
Today, fiber optic cable is used widely for communication system which is
used for transmitting the signal or data. Therefore, the maintenance of fiber optic
cable should be done frequently to ensure the best serves are obtained by subscribers.
There are many equipments are used for the maintenance of fiber optic cable such as
OTDR. Generally, OTDR is used to identify optical cable fault. There are some
reasons to analysis and measurement fiber optic faults by OTDR. One of the reasons
is OTDR set is very expensive. The problem statement in this project is to show the
simulation of an OTDR where it is will be used for knowing better OTDR. So, the
function of the OTDR will be utilized maximally.
3
1.4
PROJECT OBJECTIVES
Due to the problem statement stated above, it’s cleared that the objectives of
the project are:
i.
To know the function of OTDR.
ii.
To make the OTDR animation
iii.
To analysis the OTDR from theoretical and measurement aspect.
iv.
To find out the advantage and disadvantages of OTDR.
1.5
PROJECT’S METHODOLOGY
Phase1:Meet and discuss with my supervisors Ir. Chairulsyah Bin Abdul Wasli and
Dr Abdul Samad Bin Shibghatullah. Show the project progress to them. Get the more
information about OTDR from supervisor, internet, books, journal, thesis, and so on.
Firstly, try to understand the concept & desired result for this OTDR cases.
Phase2:For this phase, discuss with my second supervisor Dr Abdul Samad Bin
Shibghatullah and do surveys on animation software for find the best method. Find
the chosen software and learn it from supervisor, internet and books for showing the
best result of OTDR cases animation.
Phase3:For this phase, prove a few of fiber optic fault cases by representing them in
graphs and block diagram. Design the animation of OTDR cases by using FlashCS3
software. Show the design of animation to supervisors and make correction of the
design.
4
Phase4:For this phase, set the experimental OTDR for lab optoelectronic which will
be used by students. Finally, submit the thesis of this project. Figure 1.1 shows the
project flowchart.
Figure 1.1 Project Flowchart
5
1.6
REPORT STRUCTURE
This report is organized in five chapters. The first chapter gives the brief
introduction of analysis and measurement of fiber optic fault by OTDR. The
objectives and scope of the project is also explained in this chapter as follows:
Chapter I
: Covers the introduction
Chapter II
: Covers the literature review
Chapter III : Covers the design methodology
Chapter IV : Cover the result for the project and expected result
Chapter V
: Conclusion and discussion
CHAPTER II
LITERATURE REVIEW
2.1
INTRODUCTION
This chapter will look into the various aspects and the methods on research
methodology on project. This chapter will show the concept of the actual fiber optic
cable and the various related analysis. Furthermore, this chapter will show the
necessary enhancement that will make this equipment, OTDR (Optical time Domain
Reflectrometer) much more efficient equipment. Literature Review is important in
each project as a base for gathering information necessary to complete the project.
All information is gathered from various sources such as:-
1. Journal
2. Books
3. Conference Transcript
4. Thesis
5. Patent
6. Website
After searching through all this various material, all information will be
filtered to be related to OTDR. All this information will be compiled to be included
in the report.
7
2.2
FIBE
IBER OPTIC
CL
LINK
Thee simple
s
fiber
er ooptic data li
link is the main
ma part in fib
fiber optic whhich shouldd bbe
considered
c
for
f the premi
mises environm
onment. The link
li of fiberr ooptic data communicatio
co
tion
should
s
be learned
lea
to kno
now how thee ddata is transf
sferred from ssource to user.
use The mod
odel
of simple fiber
fi
optic data
da link iss sh
shown in Figure
Fig
2.1. Th
The principle
le of an optic
tical
communicat
c
ations system
m is to transm
smit a signal
al through ann optical sign
gnal throughh aan
optical
opt
fiber
er to a distant
ant receiver.. T
The electrica
ical signal iss converted
c
in
into the optic
tical
domain
do
at the
th transmitte
itter and is con
converted back
ack into the or
original elect
ctrical signal
al at
the
t receiver.[
er.[4]
Figure
re 2.1
2
Model
el of
o "simple"
e" fiber opticc ddata link
There
ere are threee m
main partss in a model of simple fibe
iber optic whi
hich are know
own
as source-uuser pair, transmitter
tra
an
and receiver.
r. Refer to Fig
Figure 2.1 above,
abo
the fib
iber
optic cable
le establishing
ng the Transm
smission Medium
Med
with th
the connectors
ors that provid
vide
the interfac
ace of the Tra
ransmitter to the Transmi
mission Mediu
dium and thee Transmissio
ssion
Medium to the Receive
ver.
Figure 2.2
.2 P
Process off ttransmission
on light in fibe
iber optic cabl
ble
8
Fiber optic cable functions as a "light guide," guiding the light introduced at
one end of the cable through to the other end. The light source can either be a lightemitting diode (LED)) or a laser. The light source is pulsed on and off, and a lightsensitive receiver on the other end of the cable converts the pulses back into the
digital ones and zeros of the original signals.
Even laser light shining through a fiber optic cable is subject to loss of
strength, primarily through dispersion and scattering of the light, within the cable
itself. When the faster laser is applied, the dispersion of light is greater. Light
strengtheners, called repeaters, may be necessary to refresh the signal in certain
applications.
2.3
OPTICAL FIBER CABLE
In an optical fiber cable, it contains one or more optical fibers. The optical
fiber elements are typically individually coated with plastic layers and it also
contained in a protective tube suitable for the environment where the cable will be
installed. The actual fiber portion of an optical is generally considered to include
both the fiber core and its cladding.
Figure 2.3 below illustrates the fiber optic cable structure. The core is the
transparent glass (or plastic) component of the cable. Light shines through it from
one end to the other. The cladding, which is a glass sheath that surrounds the core, is
a key component. Like a mirror, it reflects light back into the core. As light passes
through the cable, its rays bounce off the cladding in different ways.
The loose buffer consists of plastic tube, which is over twice the fiber
diameter in size and serves as a shield from stresses and temperature changes. As the
fiber experiences bending, pressure, or extreme temperatures, the buffer protects the
fiber and leaves room for movement and expansion. The tight buffer consists of a
plastic buffer deposited directly on the fiber coating. While differences in thermal
expansion between fiber and buffer may cause microbends, this configuration
OPTICAL TIME DOMAIN REFLECTROMETER (OTDR)
AKWANIZAM BIN AZMI
This Report Is Submitted in Partial Fulfillment of the Requirements for the
award of Bachelor of Electronic Engineering (Telecommunication Electronics)
With Honours
Faculty of Electronic Engineering and Computer Engineering
Universiti Teknikal Malaysia Melaka
30 April 2009
ii
UNIVERSTI TEKNIKAL MALAYSIA MELAKA
FAKULTI KEJURUTERAAN ELEKTRONIK DAN KEJURUTERAAN KOMPUTER
BORANG PENGESAHAN STATUS LAPORAN
PROJEK SARJANA MUDA II
Tajuk Projek
ANALYSIS AND MEASUREMENT FIBER OPTIC FAULT
:
BY USING OPTICAL TIME DOMAIN REFLECTROMETER
(OTDR)
Sesi
Pengajian
2005/09
:
Saya ………………………....AKWANIZAM BIN AZMI…………………………..……..
(HURUF BESAR)
mengaku membenarkan Laporan Projek Sarjana Muda ini disimpan di Perpustakaan dengan syaratsyarat kegunaan seperti berikut:
1.
Laporan adalah hakmilik Universiti Teknikal Malaysia Melaka.
2.
Perpustakaan dibenarkan membuat salinan untuk tujuan pengajian sahaja.
3.
Perpustakaan dibenarkan membuat salinan laporan ini sebagai bahan pertukaran antara institusi
pengajian tinggi.
4.
Sila tandakan (
):
SULIT*
(Mengandungi maklumat yang berdarjah keselamatan atau
kepentingan Malaysia seperti yang termaktub di dalam AKTA
RAHSIA RASMI 1972)
TERHAD*
(Mengandungi maklumat terhad yang telah ditentukan oleh
organisasi/badan di mana penyelidikan dijalankan)
TIDAK TERHAD
Disahkan oleh:
__________________________
(TANDATANGAN PENULIS)
Alamat : Lot 572 Kg. Air Merah,
86800, Mersing Johor
___________________________________
(COP DAN TANDATANGAN PENYELIA)
iii
“I declared that this thesis is the result of my own work except the ideas and
summaries which I have clarified their sources.”
Signature
: ………………………………………
Writer
: AKWANIZAM BIN AZMI
Date
: 30 April 2009
iv
“I hereby declare that I have read this report and in my opinion this report is
sufficient in terms of the scope and quality for the award of Bachelor of Electronic
Engineering (Telecommunication Electronic) With Honours”
Signature
: ………………………………………
Supervisor’s Name
: IR. CHAIRULSYAH WASLI
Date
:
v
DEDICATION
Special dedication to my beloved father and mother, my entire sibling and my kind
hearted supervisor Ir. Chairulsyah Wasli and my dearest friends.
vi
ACKNOWLEDGEMENT
Firstly, I would like to thank Allah because with His blessing I am able to
prepare this report and final project for Universiti Teknikal Malaysia Melaka. I wish
to thank all those who helped and encouraged me to complete my Bachelor of
Electronic Engineering (Telecommunication Electronics).
I would like to extend my sincere gratitude to my supervisor, Ir. Chairulsyah
Wasli, for his assistance and guidance toward the progress of this thesis project.
Through the year, Ir. Chairulsyah Wasli has been patiently monitoring my progress
and guided me in the right direction and offering encouragement. Obviously the
progress I had now will be uncertain without his assistance.
Likewise, I would like to thank my second supervisor, Dr Abdul Samad Bin
Shibghatullah for his assistance in creating animation by using the suitable software
and make this project possible. I would like to thank Hafizul for his encouragement
and help. Special thank to my friends Hafiz Nazar, Al-Amin and all my housemate
for giving me support and encourage me to finish this report.
This project would not have been like this if they not given great support and
encouragement on me when other academic assignments and test has pressured me.
The golden glory for me was during accomplishing this project is when my project
successfully completed in the right path.
Most of all, I would like to thank my parents for their unending support, and
my brother, whose mere existence keeps me motivated.
vii
ABSTRACT
The purpose of this project was to measure the fiber optic faults by using
Optical Time Domain Reflectrometer (OTDR) and at the same time to analyze fiber
optic faults. The software which will be used is based on the existing OTDR
simulation. The cases of fiber optic faults were learned before upgrade the OTDR
simulation. Each case is represented in form of graph for normal condition and
abnormal condition. Flash CS3 software was used to create each graph in animation
form. Then, the OTDR instrument was learned in detail by applying the instrument in
field study. The true result of fiber optic faults was investigated by using the
instrument. The result from theoretical and experimental OTDR will be compared to
ensure the valid results are obtained. The experimental OTDR is set for students in
Opto electronic laboratory. From this experiment, students can easy to understand the
operation of OTDR and they can investigate a few of events in fiber optic cable
efficiently.
viii
ABSTRAK
Tujuan projek ini ialah untuk mengukur tingkat kerosakan fiber optik dengan
menggunakan Optical Time Domain Reflectrometer (OTDR) dan pada masa yang
sama untuk menganalisa kerosakannya. Software yang akan digunakan adalah
berdasar pada simulasi OTDR yang sedia ada. Kes-kes kerosakan fiber optik
dipelajari sebelum menambah baik simulasi OTDR. Setiap kes diwakili dalam
bentuk graf untuk keadaan normal dan sebaliknya. Software Flash CS3 digunakan
untuk membuat graf dalam bentuk animasi. Kemudian, alat OTDR dipelajari dengan
mendalam, dengan menggunakan alat tersebut pada kajian lapangan. Keputusan
sebenar kerosakan fiber optik dikaji dengan menggunakan alat tersebut. Keputusan
daripada teori dan eksperimen akan dibandingkan untuk memastikan keputusan yang
betul diperolehi. Eksperimen OTDR dibuat untuk memudahkan pelajar menjalani
eksperimen ini pada masa akan datang. Para pelajar akan dapat memahami
bagaimana OTDR ini berfungsi daripada awal hingga akhir selepas mereka
melakukan eksperimen ini.
ix
TABLE OF CONTENTS
CHAPTER
I
TITLE
PAGE
THESIS TITLE
i
DECLARATION
iii
DEDICATION
v
ACKNOWLEDGEMENT
vi
ABSTRACT
vii
ABSTRAK
viii
TABLE OF CONTENTS
ix
LIST OF TABLES
xii
LIST OF FIGURES
xiii
LIST OF SYMBOLS
xv
INTRODUCTION
1
1.1
PROJECT BACKGROUND
1
1.2
SCOPE OF WORKS
2
1.3
PROBLEMS STATEMENT
2
1.4
PROJECT OBJECTIVES
3
1.5
PROJECT’S METHODOLOGY
3
1.6
REPORT STRUCTURE
5
x
II
LITERATURE REVIEW
6
2.1
INTRODUCTION
6
2.2
FIBER OPTIC LINK
7
2.3
OPTICAL FIBER CABLE
8
2.4
FIBER CLASSIFICATIONS
10
2.4.1 Single-Mode Step-Index
10
2.4.2 Multimode Step-Index
11
2.4.3 Multimode Graded-Index
12
2.5
PRINCIPLE OF OPERATION
12
2.6
ATTENUATION IN FIBER OPTIC
13
2.6.1 Dispersion
14
2.7
III
2.6.1.1 Modal Dispersion
15
2.6.1.2 Chromatic Dispersion
15
2.6.1.3 Polarization Dispersion
16
2.6.2 Absorption
17
2.6.3 Scattering
18
2.6.3.1 Stimulated Raman Scattering
19
2.6.3.2 Stimulated Brillouin Scattering
19
2.6.4 Optical Return Loss
19
APPLICATION OF OTDR
20
METHODOLOGY
21
3.1
INTRODUCTION
21
3.2
COLLECTION DATA
21
3.3
PROJECT PLANNING
22
3.4
ANIMATION TROUBLESHOOTING
23
3.5
INTRODUCTION OF OTDR
23
3.6
THE WORK OF OTDR
25
3.7
INFORMATION IN THE OTDR TRACE
28
3.7.1 Overload Recovery
29
3.7.2 Ghosts
30
xi
3.8
IV
OVERCOMING BACKSCATTER ERRORS
33
3.8.1 Resolution Limitations
33
3.8.2 Consideration For Multimode Fiber
34
RESULT AND DISCUSSION
36
4.1
RESULT FROM ANIMATION OF OTDR
36
4.2
CALCULATION RESULT AND ANALYSIS
42
4.2.1 Creating Formula
42
4.2.2 Backscattering
45
4.2.3 Reflectance
47
4.2.4 Reflection Amplitude-ORL
Specification
V
49
CONCLUSIONS
55
5.1
CONCLUSION
55
5.2
RECOMMENDATION
56
REFERENCES
APPENDIXS
57
xii
LIST OF TABLE
TABLE
TITLE
3.1
The function of each block OTDR
25
4.2
Output Power Values
44
4.3
Backscattering value
46
4.4
Typical values of backscatter coefficient for
48
Multimode fibers
PAGE
xiii
LIST OF FIGURE
FIGURE
TITLE
PAGE
1.1
Project Flowchart
2.1
Model of simple fiber optic data link
7
2.2
Fiber optic cable structure
8
2.3
Process of transmission light
9
2.4
Single-mode step index fiber
10
2.5
Multimode step-index optical fiber
11
2.6
Multimode Grade-index optical fiber
11
2.7
Snell’s law
12
2.8
Typical Dispersion vs. Wavelength Curves
14
2.9
Lingering materials
16
3.1
Gantt chart
19
3.3
The block diagram of the conventional OTDR
21
3.4
Scattering in an optical fiber
23
3.5
OTDR Display
24
3.6
Increasing the pulse width increases the backscatter level
24
3.7
OTDR trace information
26
3.8
OTDR launch pulse and launch cable
28
3.9
OTDR ghosts
29
3.10
Loss errors in OTDR measurements
30
.
4
xiv
LIST OF FIGURE
FIGURE
TITLE
PAGE
3.11
The OTDR pulse length limits its resolution .
34
3.12
OTDR see middle of multimode fiber core
35
4.1
Build of OTDR buttons
36
4.2
Display of graph case 1
37
4.3
Display of graph case 2
37
4.4
Display of graph case 3
38
4.5
Comparing of each graph in a figure
39
4.6
Display of graph from oscilloscope
40
4.7
Display of graph case 4
41
4.8
The fiber optic block diagram
42
4.9
The loss of fiber optic
43
4.10
Graph of output power versus length
45
4.11
Graph of backscattering versus distance
47
4.12
ORL value of a reflection feature
49
4.13
OTDR pulse generator software
52
4.14
Building of an experimental OTDR
52
4.15
Measurement of power
53
4.16
Result of Experimental OTDR
53
xv
LIST OF SYMBOL / ACRONYM
ADC
Analog Digital Converter
APD
Avalance Photodiode
DC
Direct Current
GI
Graded Index
LED
Light Emitting Diode
OTDR
Optical time domain reflectrometer
PD
Photo diode
SI
Step Index
I/O
Input and Output
Pi
Input power
Pin
Incident power
PT
Transferring power
Pref
Reflected power
Po
Output power
a
Attenuation
R
Reflectance
l
Length
L
Loss
d
distance
K @ B (s-1)
Backscattering coefficient
A
Reflection amplitude (in dB), as measured by the OTDR
T
V
OTDR measurement pulse width (in nanoseconds)
Voltage
xvi
APPENDIX LIST
APPENDIX TITLE
PAGES
A
YOKOGAWA OTDR
58
B
Fiber optic patch cord
68
C
Characteristics of fiber
70
D
Experimental OTDR Laboratory
72-84
CHAPTER I
INTRODUCTION
1.1
PROJECT BACKGROUND
In telecommunication field, fiber optic cable is the main part of transmission
of data. So, one of the main maintenance instruments fiber optic cable is optical
time-domain reflectrometer (OTDR). This instrument is used to test fiber links by
detecting losses and to know what types of faults have occurred on these links, as
well as where they are located. Generally, there are a few types of fiber faults likes
overload recovery, ghosts and backscatter variability errors.
Before this instrument is used in fiber optic cable plant, we should understand
how it works, the function of its buttons and what the types of types of faults. If not,
we will face problems of using it. We should have sufficient knowledge of OTDR
operation to ensure that the good data can be obtained and it will be used optimally.
This project is targeted to accomplish finish in six months timeline. The
ultimate goal is to examine the OTDR in detail and show the examples of good and
bad data by using flash CS3 software. Beside this, experimental OTDR is set for
optoelectronic laboratory which will be used by students.
2
1.2
SCOPES OF WORK
The scopes of work for the project include the following areas:
i.
The study and understanding of OTDR the cases of fiber optic faults.
ii.
Build the animation for fiber faults cases by using Flash CS3.
iii.
Find the a few types of OTDR simulation and investigate them.
iv.
Find the true result of OTDR cases and compare with theoretical animation.
v.
The analysis of the fiber optic faults from the OTDR instrument.
Other scopes of work include:
1.3
1.
Maintain good log book record
2.
Prepare the necessary documents
3.
Publishing final report
4.
Project Presentation
PROBLEM STATEMENTS
Today, fiber optic cable is used widely for communication system which is
used for transmitting the signal or data. Therefore, the maintenance of fiber optic
cable should be done frequently to ensure the best serves are obtained by subscribers.
There are many equipments are used for the maintenance of fiber optic cable such as
OTDR. Generally, OTDR is used to identify optical cable fault. There are some
reasons to analysis and measurement fiber optic faults by OTDR. One of the reasons
is OTDR set is very expensive. The problem statement in this project is to show the
simulation of an OTDR where it is will be used for knowing better OTDR. So, the
function of the OTDR will be utilized maximally.
3
1.4
PROJECT OBJECTIVES
Due to the problem statement stated above, it’s cleared that the objectives of
the project are:
i.
To know the function of OTDR.
ii.
To make the OTDR animation
iii.
To analysis the OTDR from theoretical and measurement aspect.
iv.
To find out the advantage and disadvantages of OTDR.
1.5
PROJECT’S METHODOLOGY
Phase1:Meet and discuss with my supervisors Ir. Chairulsyah Bin Abdul Wasli and
Dr Abdul Samad Bin Shibghatullah. Show the project progress to them. Get the more
information about OTDR from supervisor, internet, books, journal, thesis, and so on.
Firstly, try to understand the concept & desired result for this OTDR cases.
Phase2:For this phase, discuss with my second supervisor Dr Abdul Samad Bin
Shibghatullah and do surveys on animation software for find the best method. Find
the chosen software and learn it from supervisor, internet and books for showing the
best result of OTDR cases animation.
Phase3:For this phase, prove a few of fiber optic fault cases by representing them in
graphs and block diagram. Design the animation of OTDR cases by using FlashCS3
software. Show the design of animation to supervisors and make correction of the
design.
4
Phase4:For this phase, set the experimental OTDR for lab optoelectronic which will
be used by students. Finally, submit the thesis of this project. Figure 1.1 shows the
project flowchart.
Figure 1.1 Project Flowchart
5
1.6
REPORT STRUCTURE
This report is organized in five chapters. The first chapter gives the brief
introduction of analysis and measurement of fiber optic fault by OTDR. The
objectives and scope of the project is also explained in this chapter as follows:
Chapter I
: Covers the introduction
Chapter II
: Covers the literature review
Chapter III : Covers the design methodology
Chapter IV : Cover the result for the project and expected result
Chapter V
: Conclusion and discussion
CHAPTER II
LITERATURE REVIEW
2.1
INTRODUCTION
This chapter will look into the various aspects and the methods on research
methodology on project. This chapter will show the concept of the actual fiber optic
cable and the various related analysis. Furthermore, this chapter will show the
necessary enhancement that will make this equipment, OTDR (Optical time Domain
Reflectrometer) much more efficient equipment. Literature Review is important in
each project as a base for gathering information necessary to complete the project.
All information is gathered from various sources such as:-
1. Journal
2. Books
3. Conference Transcript
4. Thesis
5. Patent
6. Website
After searching through all this various material, all information will be
filtered to be related to OTDR. All this information will be compiled to be included
in the report.
7
2.2
FIBE
IBER OPTIC
CL
LINK
Thee simple
s
fiber
er ooptic data li
link is the main
ma part in fib
fiber optic whhich shouldd bbe
considered
c
for
f the premi
mises environm
onment. The link
li of fiberr ooptic data communicatio
co
tion
should
s
be learned
lea
to kno
now how thee ddata is transf
sferred from ssource to user.
use The mod
odel
of simple fiber
fi
optic data
da link iss sh
shown in Figure
Fig
2.1. Th
The principle
le of an optic
tical
communicat
c
ations system
m is to transm
smit a signal
al through ann optical sign
gnal throughh aan
optical
opt
fiber
er to a distant
ant receiver.. T
The electrica
ical signal iss converted
c
in
into the optic
tical
domain
do
at the
th transmitte
itter and is con
converted back
ack into the or
original elect
ctrical signal
al at
the
t receiver.[
er.[4]
Figure
re 2.1
2
Model
el of
o "simple"
e" fiber opticc ddata link
There
ere are threee m
main partss in a model of simple fibe
iber optic whi
hich are know
own
as source-uuser pair, transmitter
tra
an
and receiver.
r. Refer to Fig
Figure 2.1 above,
abo
the fib
iber
optic cable
le establishing
ng the Transm
smission Medium
Med
with th
the connectors
ors that provid
vide
the interfac
ace of the Tra
ransmitter to the Transmi
mission Mediu
dium and thee Transmissio
ssion
Medium to the Receive
ver.
Figure 2.2
.2 P
Process off ttransmission
on light in fibe
iber optic cabl
ble
8
Fiber optic cable functions as a "light guide," guiding the light introduced at
one end of the cable through to the other end. The light source can either be a lightemitting diode (LED)) or a laser. The light source is pulsed on and off, and a lightsensitive receiver on the other end of the cable converts the pulses back into the
digital ones and zeros of the original signals.
Even laser light shining through a fiber optic cable is subject to loss of
strength, primarily through dispersion and scattering of the light, within the cable
itself. When the faster laser is applied, the dispersion of light is greater. Light
strengtheners, called repeaters, may be necessary to refresh the signal in certain
applications.
2.3
OPTICAL FIBER CABLE
In an optical fiber cable, it contains one or more optical fibers. The optical
fiber elements are typically individually coated with plastic layers and it also
contained in a protective tube suitable for the environment where the cable will be
installed. The actual fiber portion of an optical is generally considered to include
both the fiber core and its cladding.
Figure 2.3 below illustrates the fiber optic cable structure. The core is the
transparent glass (or plastic) component of the cable. Light shines through it from
one end to the other. The cladding, which is a glass sheath that surrounds the core, is
a key component. Like a mirror, it reflects light back into the core. As light passes
through the cable, its rays bounce off the cladding in different ways.
The loose buffer consists of plastic tube, which is over twice the fiber
diameter in size and serves as a shield from stresses and temperature changes. As the
fiber experiences bending, pressure, or extreme temperatures, the buffer protects the
fiber and leaves room for movement and expansion. The tight buffer consists of a
plastic buffer deposited directly on the fiber coating. While differences in thermal
expansion between fiber and buffer may cause microbends, this configuration