In Campus Communication system Using Optical Principle And Techniques (Transmitter).
i
IN CAMPUS COMMUNICATION SYSTEM USING OPTICAL PRINCIPLE AND TECHNIQUE (TRANSMITTER)
SYAHMI BIN GHAZALI
This Report Is Submitted in Partial Fulfillment of the Requirements for the award of Bachelor of Electronic Engineering (Telecommunication Electronic) With Honours
Faculty of Electronic Engineering and Computer Engineering Universiti Teknikal Malaysia Melaka
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UNIVERSTI TEKNIKAL MALAYSIA MELAKA
FAKULTI KEJURUTERAAN ELEKTRONIK DAN KEJURUTERAAN KOMPUTER
BORANG PENGESAHAN STATUS LAPORAN
PROJEK SARJANA MUDA II
Tajuk Projek : IN CAMPUS COMMUNICATION SYSTEM USING
OPTICAL PRINCIPLE AND TECHNIQUE (TRANSMITTER) Sesi
Pengajian : 2009/10
Saya SYAHMI BIN GHAZALI
mengaku membenarkan Laporan Projek Sarjana Muda ini disimpan di Perpustakaan dengan syarat-syarat 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:
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―I declare that this thesis is the result of my own work except the ideas and summaries which I have clarified their sources.‖
Signature : ………
Writer : SYAHMI BIN GHAZALI Date : 2 Mei 2009
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―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 : MR. TAN KIM SEE
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DEDICATION
Specially dedicated to my father, mother, brother and my friends for their understanding, concern, care and continuous support.
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ACKNOWLEDGEMENT
Firstly, thanks to Allah because with His Blessings, I am able to complete my Bachelor Degree Project and prepare this report.
I wish to express my appreciation to my supervisor, Mr. Tan Kim See for his support, guidance and advice during the completion of this final project.
Special thanks to my partner of this project, Mr. Azidzin, my friends, Mr. Lokman Hakim, Mr. Firdaus Hassan and all my classmates for giving me the support and encouragement to finish this report.
As a result of their kindness, I was fully motivated to complete this task in spite of the other academic assignments and tests which I had to go through. I hope the glory for me to complete this project is shared by all those I love. This will inspire me and lead me to the right path for my future endeavors.
Finally, I would like to express my deepest gratitude to my fellow friends and my beloved family for all the encouragement and inspiration.
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ABSTRACT
This new generation network nowadays needs to fulfill the demands of the new information age, which requires improved scalability, flexibility, and dynamic delivery of communication services. An evolution of the network is underway to meet this demand. The evolution introduces new network elements supporting an architecture that is better suited for the dynamic global distribution of broadband based services. As such, the next major step in the progression is the wide scale deployment of intelligent optical switches. The purpose of this study is to investigate the characteristic and the behavior of optical techniques to implement an efficient FOS communication system. For the transmitter side, the laser is used to transmit the beam directly to the receiver. To interface with the computer, the Borland C++ 3.1 programming is used. The framework used for this method is general enough for further investigation by either evaluating other parameters by extending its applications in the communication network. From this research, it is hope that more in-depth knowledge on the transceiver, laser and photo diodes, free space propagation, line of sight and data propagation are acquired.
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ABSTRAK
Rangkaian telekomunikasi yang wujud masa kini perlu memenuhi permintaan teknologi maklumat baru yang merangkumi peningkatan terhadap pengukuran, flexibilitinya, dan juga kemudahan dalam penghantaran telekomunikasi. Adalah penting bagi perubahan rangkaian ini supaya ia dapat memenuhi permintaan sejagat. Perubahan ini memperkenalkan satu teknologi baru yang mampu menyokong kemudahan teknologi maklumat luas yang lebih dinamik dalam globalisasi. Oleh itu, langkah penting seterusnya adalah penggunaaan suis optik dalam rangkaian secara meluas. Tujuan kajian ini adalah bagi mengkaji dan menyiasat bagaimana perwatakan dan fungsi komunikasi laser supaya dapat implemantasikan secara efektif ke atas system rangkaian optic. Untuk bahagian pemancar, pancaran laser perlu menembak secara terus kepada fototransistor pada sebelah penerima. Program Borland C++ 3.1 digunakan untuk pengaturcaraan dengan komputer. Rangka pengukuran adalah bersifat umum dan boleh digunakan untuk kajian lanjut samada bagi menguji parameter lain bagi meluaskan penggunaannya dalam rangkaian telekomunikasi optik. Dari penyelidikan ini, adalah diharapkan bahawa pengetahuan yang lebih mendalam dapat diperolehi tentang laser dan diod foto, perambatan ruang bebas, garis pandangan, dan perambatan data.
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TABLE OF CONTENTS
CHAPTER PAGE
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 xvi
I INTRODUCTION 1
1.1 INTRODUCTION OF PROJECT 1
1.2 PROJECT OBJECTIVE 2
1.3 PROBLEMS STATEMENT 2
1.4 SCOPES OF WORKS 3
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II LITERATURE REVIEW 5
2.1 INTRODUCTION 6
2.2 HISTORY ABOUT FSO 6
2.3 FREE SPACE OPTIC TECHNOLOGIES 8
2.4 FSO CHARACTERISTIC 9
2.5 THE CHARACTERISTIC OF FIBER OPTIC 12
2.6 THE BENEFIT OF USING FSO 13
2.7 THE CHALLENGE OF FSO 13
2.7.1 Overcome the problem 15
2.8 SYSTEM OVERVIEM OF FSO 15
2.9 TRANSMITTER SIDE 17
2.9.1 Transceiver 17
2.9.2 Sample of Transceiver 18 2.9.3 UV transceiver technology 19 2.9.1 UV transmitter technology 19 2.9.1 UV receiver technology 19
2.10 TRACKING SYSTEM 20
2.11 PHYSICAL LAYER OPTICAL WIRELESS 21 2.11.1 Optical power measurement 21 2.11.2 Transmission Formula 22 2.11.3 Fade margin of an FSO 23 2.12 SERIAL NETWORKING CONSIDERATION 24
2.12.1 Characteristic of Transmission (TCP) 24
2.13 LASER SYSTEM 24
2.12.1 Laser safety 25
2.14 TRANSMISSION HAZARD 25
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2.16 POWER BUDGET 29
2.16.1 Power Budgeting process 29
2.17 INFRARED 31
2.18 BIT ERROR RATE, DATA RATES 32 2.19 MAX232A RS-232 LINE DRIVER 34
2.20 HEX OPEN-COLLECTOR BUFFER 35
2.21 SCHMITT TRIGGERS HEX INVERTER 35 2.22 PHOTO-TRANSISTOR (OP505A) 37 2.23 OPTICAL SIGNAL TO NOISE RATIO 38
2.24 CROSSTALK 38
2.24.1 Measuring Crosstalk 39
2.25 ISOLATION 40
2.25.1 Measuring Isolation 40
2.26 ISERTION LOSS 41
2.26.1 way to Measure Insertion Loss 41
III METHODOLOGY 43
3.1 INTRODUCTION 43
3.2 PROJECT PLANNING 43
3.2.1 Gant chart 44
3.3 LIST OF COMPONENT 44
3.4 PREPARE FOR THE SERIAL CONNECTOR 45
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IV RESULT AND DISCUSSION 48
4.1 CIRCUIT DIAGRAM 48
4.2 CIRCUIT LAYOUT 49
4.3 CIRCUIT DESCRIPTION 49
4.4 CIRCUIT CONSRUCTION 50
4.5 CIRCUIT OVERVIEW 52
4.6 CIRCUIT TESTING 53
4.6.1 Coding Compiler Borland C++3.1 54
V CONCLUSIONS 57
5.1 CONCLUSION 57
5.2 RECOMMENDATION 58
REFERENCES 59
APPENDICES 60
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LIST OF TABLE
TABLE TITLE PAGE
2.1 Fade Margin of FSO 23
2.2 IEC 60825-1 Laser Classification System 26
2.3 Attenuation 30
3.1 Gant Chart psm 2 44
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LIST OF FIGURE
FIGURE TITLE PAGE
1.1 Flow chart of the methodology . 5
2.1 Growing Process of FSO 7
2.2 The point to point connection between 8 Building
2.3 Network of FSO 9
2.4 Block diagram of the FSO 10
2.5 Clear air 11
2.6 Moderate Fog 11
2.7 The fog 13
2.8 Physical Obstruction 14
2.9 Swayed Building 14
2.10 Laser Safety 15
2.11 Basic Overview communications FSO 16
2.12 Block diagram in Transceiver 17
2.13 Flight 100/100E Transceiver 18
2.14 Block diagram of communication system 20 2.15 Block diagram of the Tracking system 21 2.16 Calculation of Beam-width 22 2.18 BER versus transmitted power for different weather 31
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2.19 Fog/snowstorm condition 33
2.20 BER versus Range at 1.25 Gbit/s 33
2.21 Top view of MAX232A 34
2.22 Operation inside the MAX232A 34
2.23 Diagram of Hex Open Collector Buffer 35
2.24 Connection diagram 35
2.25 Top view of the 74LS14 36
2.26 Side view of the 74LS14 36
2.27 Diagram for photo-transistor OP505A 37
2.27.1 Typically spectral response 37 2.27.2 2 Coupling Characteristic 37 2.28 Key spectral parameters for output spectrum 38 2.29 Gaussian Crosstalk and Isolation Measurement 39
2.30 Gaussian Insertion Loss Measurement 42
2.31 Solder side view to wire 46
2.32 Flow chart of circuit troubleshooting 47
4.1 The schematic of the transceiver 48
4.2 PCB patterns for the transceiver 49
4.3 Connections to the external component for transceiver 52
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LIST OF SYMBOL / ACRONYM
Pi Input power
Pin Incident power
PT Transferring power
Pref Reflected power
Po Output power
a Attenuation
R Receiver Sensitivity for BER T Transmission Power
NT No. of Transmitters A Receiver Aperture Area NR No. of Receivers
θ Beam Divergence
l Length L Loss
d Path Length LG Geometric Loss
LF Fixed System Losses (dB)
V Voltage
PD Photo diode
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CHAPTER 1
INTRODUCTION
This chapter consists of introduction, scope of works, project objective, problem statement and background.
1.1 Introduction of the project
A fiber optic communication link uses light sources and detectors to send and receive information through a fiber optic cable. Similarly, wireless optical communications uses light sources and detectors to send and receive information, but through the atmosphere instead of a cable. The motivation for free space optical communications is to eliminate the cost, time, and effort of installing fiber optic cable, yet retain the benefit of high data rates for transmission of voice, data, images, and video.
Free space, dynamic, optical wireless communications will require topology control for optimization of network performance. Such networks may need to be
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2 configured for connectivity, reliability and quality of service. Topology control involves the introduction of new links and nodes into the network too achieve such performance objectives through reconfiguration as well as precise pointing, acquisition, tracking and steering of laser beams. The most important consideration in wireless optical communications link planning process is to ensure that there is sufficient optical power received by the transceiver.
1.2 Project Objective
The main objective of this project is to study and provide the wireless connection by using the optical principles and techniques. This project is very similar to the fiber optic communication system except the medium is free space instead of fiber. However, this wireless optical connection offers many advantages when compared to the fiber. Its deployment requires a fraction of the time and cost as compared to conventional fiber networks, allowing carriers to generate revenue quickly while taking advantage of the high capacity of optical transmission.
This project functions depend on the free space optic technologies as the light from the transmitter is directed to the receiver through free space and this is managed in the duplex transmission format. Light travels through air faster than it does through glass, so it is fair to classify this project technology as optical communications at the speed of light. Besides, this technology are been used in many university and company, but some people doesn’t know about them because it secure.
1.3 Problem Statement
There are many challenges in undertaking this project. The medium of transmission connection between the transmitter and receiver is the biggest problem of the project. Firstly, the fog is the greatest challenge of this project. The fog is a vapor that is comprised with many tiny drops of water. The drops of water can ―modify light characteristics or completely hinder the passage of light through a combination of
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3 absorption, scattering and reflection. Through absorption, the drops of water take away the photons from the laser beam, which reduces the power of the beam.
Secondly, the physical obstructions such as buildings and trees will provide the line of sight for the light beam. As mentioned, this project is a line of sight technology. If something comes in the way of the transmission path, the connection will be cut off. The problem is common because the laser beam is sent through the atmosphere, so the beam can be obstructed easily even if a bird flies by. The third is the swaying building. When a building is swayed, even to a slightest degree, the laser beam may miss the target in transmission.
Many people have the wrong perception that optical laser is dangerous because the beam which is intense and coherent is directed in the open air. However, it is proven otherwise as the beam is not directed into the eyes. Laser is powerful, but its power depends on its wavelength. Infrared radiation at 1550 nm [wavelength] tends not to reach the retina of the eye, being mostly absorbed by the cornea.
1.4 Scope of works
The scopes of work for the project include the following areas:
1. The understanding of the circuit operation transceiver (transmitter) of the project.
2. To study about the transmitter and receiver
- The completed system consist of two transceiver, each capable of simultaneously transmitting and receiving either analogue or digital information. The user has an option to manually select between either analogue or digital information via means of two switches which control the laser transmitter and receiver.
3. Identification of the parameters and specification about the laser to be considered in this project.
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4 5. To study the interface between computer and the circuit.
6. To study about the executable coding Borland C++ 3.1
1.5 Project’s Methodology
Project Planning
Understanding the concept and theory of the project
Prepare Gantt Chart for guidelines and progress of the project
Literature Review
Background reading and references Search for suitable and practical circuits
Identify the equipment and some important component to be added to my project
Develop the prototype of this project Simulate and analysis of the prototype
Finishing
Test of the prototype in operation, application and result Presentation on outcome of this project
Write the final report
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CHAPTER 2
LITERATURE REVIEW
This chapter will discuss precisely about the project, including the factors that should be considered before chosing a transceiver and the laser circuit that needs fully attention for this research.
2.1 Introduction
In this chapter, we will focus on the research about the methodology on the proposed project. Past projects, thesis and every journal about the wireless optical communication will be included in this chapter. This will covered the whole of the project progressing and the related analysis. Every data and idea for this project will be analysis to bring the better outcome. An initial hurdle faced by early means of laser communication was the enormous heat generated by pumped laser action.
2.2 History about the Free space Optical Communication Technologies
The idea of Free-Space Optics (FSO) has been around for more than three decades. In fact, many scientists had already developed FSO at that time, but the
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7 technology was not adequate to make FSO practical in real life, so the research was stopped. Sending optical signals through the air is not a new idea. Alexander Graham Bell demonstrated it using reflected sunlight with his Photophone in 1880.
Nearly a century later, Bell Labs hoisted an early laser to the top of a microwave tower at its Murray Hill, NJ, headquarters to send pulses 40 km to its Holmdel site. When FSO was first developed, it was used in many aircraft’s operations for data transmission. Now, FSO is becoming more popular, and it is in the trend of replacing other transmission methods.
FSO is a new technology, and it needs time to be adopted by others. The idea of FSO had been introduced already. Now, it is being used by smaller companies that are willing to explore new alternatives. When FSO is proven to be cost-effective, larger companies would also adopt FSO, and all other companies would be pressured into adopting FSO due to competitions in the market. When majority of the companies have adopted FSO, FSO will become the mainstream technology, and all other technologies will become obsolete.
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2.3 Free Space Optic technologies
Free-Space Optics (FSO) is capable of transmitting information from one place to another. It is a line-of-sight technology that needs a clear transmission path, without any obstacle, between a sender and a receiver to enable the transmission to function correctly. FSO uses laser beam to transmit information through air. This line-of-sight technology approach uses invisible beams of light to provide optical bandwidth connections.
It's capable of sending up to 1.25 Gbps of data, voice, and video communications simultaneously through the air enabling fiber-optic connectivity without requiring physical fiber-optic cable. It enables optical communications at the speed of light. And it forms the basis of a new category of products optical wireless products from FSO Technologies’, the recognized leader in outdoor wireless bridging communications.
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absorption, scattering and reflection. Through absorption, the drops of water take away the photons from the laser beam, which reduces the power of the beam.
Secondly, the physical obstructions such as buildings and trees will provide the line of sight for the light beam. As mentioned, this project is a line of sight technology. If something comes in the way of the transmission path, the connection will be cut off. The problem is common because the laser beam is sent through the atmosphere, so the beam can be obstructed easily even if a bird flies by. The third is the swaying building. When a building is swayed, even to a slightest degree, the laser beam may miss the target in transmission.
Many people have the wrong perception that optical laser is dangerous because the beam which is intense and coherent is directed in the open air. However, it is proven otherwise as the beam is not directed into the eyes. Laser is powerful, but its power depends on its wavelength. Infrared radiation at 1550 nm [wavelength] tends not to reach the retina of the eye, being mostly absorbed by the cornea.
1.4 Scope of works
The scopes of work for the project include the following areas:
1. The understanding of the circuit operation transceiver (transmitter) of the project.
2. To study about the transmitter and receiver
- The completed system consist of two transceiver, each capable of simultaneously transmitting and receiving either analogue or digital information. The user has an option to manually select between either analogue or digital information via means of two switches which control the laser transmitter and receiver.
3. Identification of the parameters and specification about the laser to be considered in this project.
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5. To study the interface between computer and the circuit. 6. To study about the executable coding Borland C++ 3.1
1.5 Project’s Methodology
Project Planning
Understanding the concept and theory of the project
Prepare Gantt Chart for guidelines and progress of the project
Literature Review
Background reading and references Search for suitable and practical circuits
Identify the equipment and some important component to be added to my project
Develop the prototype of this project Simulate and analysis of the prototype
Finishing
Test of the prototype in operation, application and result Presentation on outcome of this project
Write the final report
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CHAPTER 2
LITERATURE REVIEW
This chapter will discuss precisely about the project, including the factors that should be considered before chosing a transceiver and the laser circuit that needs fully attention for this research.
2.1 Introduction
In this chapter, we will focus on the research about the methodology on the proposed project. Past projects, thesis and every journal about the wireless optical communication will be included in this chapter. This will covered the whole of the project progressing and the related analysis. Every data and idea for this project will be analysis to bring the better outcome. An initial hurdle faced by early means of laser communication was the enormous heat generated by pumped laser action.
2.2 History about the Free space Optical Communication Technologies
The idea of Free-Space Optics (FSO) has been around for more than three decades. In fact, many scientists had already developed FSO at that time, but the
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technology was not adequate to make FSO practical in real life, so the research was stopped. Sending optical signals through the air is not a new idea. Alexander Graham Bell demonstrated it using reflected sunlight with his Photophone in 1880.
Nearly a century later, Bell Labs hoisted an early laser to the top of a microwave tower at its Murray Hill, NJ, headquarters to send pulses 40 km to its Holmdel site. When FSO was first developed, it was used in many aircraft’s operations for data transmission. Now, FSO is becoming more popular, and it is in the trend of replacing other transmission methods.
FSO is a new technology, and it needs time to be adopted by others. The idea of FSO had been introduced already. Now, it is being used by smaller companies that are willing to explore new alternatives. When FSO is proven to be cost-effective, larger companies would also adopt FSO, and all other companies would be pressured into adopting FSO due to competitions in the market. When majority of the companies have adopted FSO, FSO will become the mainstream technology, and all other technologies will become obsolete.
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2.3 Free Space Optic technologies
Free-Space Optics (FSO) is capable of transmitting information from one place to another. It is a line-of-sight technology that needs a clear transmission path, without any obstacle, between a sender and a receiver to enable the transmission to function correctly. FSO uses laser beam to transmit information through air. This line-of-sight technology approach uses invisible beams of light to provide optical bandwidth connections.
It's capable of sending up to 1.25 Gbps of data, voice, and video communications simultaneously through the air enabling fiber-optic connectivity without requiring physical fiber-optic cable. It enables optical communications at the speed of light. And it forms the basis of a new category of products optical wireless products from FSO Technologies’, the recognized leader in outdoor wireless bridging communications.